The rapid development of artificial intelligence technology has exerted a great influence on all fields of the world, which of course also affects the world economy. This has also aroused a large number of economists' interest in this proposition. Since the definition of artificial intelligence is not unified yet, the results from previous researches are not reliable enough. At present, most scholars use the neoclassical growth model or task-based model to explore the path of artificial intelligence on economic variables. There into, most of them use the degree of automation to represent the artificial intelligence. They find that the degree of automation can change the proportion of industries. This only verifies that artificial intelligence can affect the economic variables. But the magnitude of artificial intelligence on economic variables can not be correctly estimated. Therefore, in order to have a better understanding on the impact of artificial intelligence on economic growth, this paper systematically reviews and collates previous literature on this topic. The results of this paper indicate that both in theoretical and empirical studies, artificial intelligence has a positive effect on economic growth. Then, some suggestions and limitations have also been put forward accordingly.


Gene therapy offers novel possibilities for the treatment of rheumatoid arthritis. Present research is directed toward harnessing gene transfer technology to deliver genes whose products possess antiarthritic properties; the current emphasis is on transferring genes encoding secreted proteins. Genes may be delivered locally to individual diseased joints or systemically to extra-articular sites where the secreted gene products may enter the circulation. Local delivery is more laborious and unlikely to address systemic components of rheumatoid arthritis but should avoid side effects. Either ex vivo or in vivo strategies may be used to deliver the genes to the target tissues. Ex vivo techniques are more cumbersome but safer, because all genetic manipulations occur outside the body and cells may be extensively screened prior to implantation. A variety of vectors, including retrovirus, adenovirus, herpes simplex virus, and liposomes, as well as naked DNA, have been tested for their ability to deliver genes to joints. At the present stage of vector development, adenovirus seems best suited for in vivo gene delivery to synovium, but several authors have noted an inflammatory response, resulting in loss of gene expression. Ex vivo gene transfer using a retrovirus encoding human interleukin-1 receptor antagonist has succeeded in obtaining high intra-articular transgene expression with promising antiarthritic effects in animal models. Based on these data, the first human gene therapy trial for arthritis has been approved by the US Food and Drug Administration and will begin shortly.


Recently developed spatial capture-recapture (SCR) models represent a major advance over traditional capture-recapture (CR) models because they yield explicit estimates of animal density instead of population size within an unknown area. Furthermore, unlike nonspatial CR methods, SCR models account for heterogeneity in capture probability arising from the juxtaposition of animal activity centers and sample locations. Although the utility of SCR methods is gaining recognition, the requirement that all individuals can be uniquely identified excludes their use in many contexts. In this paper, we develop models for situations in which individual recognition is not possible, thereby allowing SCR concepts to be applied in studies of unmarked or partially marked populations. The data required for our model are spatially referenced counts made on one or more sample occasions at a collection of closely spaced sample units such that individuals can be encountered at multiple locations. Our approach includes a spatial point process for the animal activity centers and uses the spatial correlation in counts as information about the number and location of the activity centers. Camera-traps, hair snares, track plates, sound recordings, and even point counts can yield spatially correlated count data, and thus our model is widely applicable. A simulation study demonstrated that while the posterior mean exhibits frequentist bias on the order of 5-10% in small samples, the posterior mode is an accurate point estimator as long as adequate spatial correlation is present. Marking a subset of the population substantially increases posterior precision and is recommended whenever possible. We applied our model to avian point count data collected on an unmarked population of the northern parula (Parula americana) and obtained a density estimate (posterior mode) of 0.38 (95% CI: 0.19-1.64) birds/ha. Our paper challenges sampling and analytical conventions in ecology by demonstrating that neither spatial independence nor individual recognition is needed to estimate population density - rather, spatial dependence can be informative about individual distribution and density.


Primary Objective: This paper critically examines the influence neoliberalism has had on education in general and health and physical education (HPE) in particular in Aotearoa New Zealand. Main Outcomes and Results: Two of the most significant changes fall under the rubric of provision. First, recent government strategy has seen the amalgamation of colleges of education with universities and an associated pressure to rationalise professional programmes to academic options. For many teacher educators this widespread re-ordering of job descriptions, coupled with institutional responses to a national drive towards literacy and numeracy attention, has placed several HPE initial teacher education programmes in a precarious position. The second change has been the marked appearance of agencies and organisations that have assumed a right to deliver parts of curriculum and co-curriculum within many schools. Conclusions: While HPE has retained its status as a component of the most recent National Curriculum of Aotearoa New Zealand, a casting eye across the education landscape would reveal a series of changes that are having direct and indirect influences on this area of learning. These acknowledged changes, among others, are gradually eroding the political and professional autonomy of HPE.


China's development over the last few decades has been characterized by high rates of economic growth, large-scale migration from rural areas to the fast-growing cities accompanied by changes in lifestyles, and steady population growth. These developments have left deep marks on resource availability and quality. In this article we conduct a scenario analysis of how lifestyle changes and other major developments might affect water resources.

China has the longest tradition in river and water resource management in the world. Its civilization has sought to control the effects of floods and drought for thousands of years and has utilized water flows for irrigation and navigation. In the last century, competing uses such as domestic, municipal, and industrial water consumption have also become reasons for the regulation of and large-scale abstraction of water.

To investigate the major changes in economy and society and their effects on the water situation in China, a set of scenarios is developed and analyzed within a structural economics framework. A hydrological model that represents water flows in the major watersheds is linked to a regional input-output model that represents socioeconomic activities in the major economic-administrative regions of China. The regional analysis shows that the North and Northwest regions are water-scarce and that lifestyle changes and technical shifts are the most important factors driving future water consumption.


The study of the relationships between pre‐cancer and cancer and identification of early driver mutations is becoming increasingly important as the value of molecular markers of early disease and personalised drug targets is recognized, especially now the extent of clonal heterogeneity in fully invasive disease is being realized. It has been assumed that pre‐cancerous lesions exhibit a fairly passive progression to invasive disease; the degree to which they, too, are heterogeneous is unknown. We performed ultra‐deep sequencing of thousands of selected mutations, together with copy number analysis, from multiple, matched pre‐invasive lesions, primary tumours and metastases from five patients with oral cancer, some with multiple primary tumours presenting either synchronously or metachronously, totalling 75 samples. This allowed the clonal relationships between the samples to be observed for each patient. We expose for the first time the unexpected variety and complexity of the relationships between this group of oral dysplasias and their associated carcinomas and, ultimately, the diversity of processes by which tumours are initiated, spread and metastasize. Instead of a series of genomic precursors of their adjacent invasive disease, we have shown dysplasia to be a distinct dynamic entity, refuting the belief that pre‐cancer and invasive tumours with a close spatial relationship always have linearly related genomes. We show that oral pre‐cancer exhibits considerable subclonal heterogeneity in its own right, that mutational changes in pre‐cancer do not predict the onset of invasion, and that the genomic pathway to invasion is neither unified nor predictable. Sequence data from this study have been deposited in the European Nucleotide Archive, Accession No. PRJEB6588. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


As a building ages, its components require replacement or retrofitting. Instead of upgrading one component at a time, combining energy efficiency measures in an integrated fashion can yield far greater savings. However, this information is rarely available to building owners. The Spark tool is under development by the Northwest Energy Efficiency Alliance (NEEA) to quickly demonstrate the benefits and cost-effectiveness of performing a combination of energy efficiency measures for a deep energy retrofit on an office building. It provides recommendations on which systems to replace, retrofit, or leave in place based on custom energy simulations run on demand. The tool relies on OpenStudio models and a suite of measures. Two baseline models were created based on actual buildings – one mid-rise and one high-rise office building. The tool includes the selection of four different HVAC designs for replacement or retrofitting as well as upgrade options for plant equipment, plug loads, lighting, and envelope. A web interface allows owners to enter information about their office including the climate, utility bills, and age of equipment. Once the selections are complete, the information is sent to the model which applies the appropriate efficiency measures and the simulation is performed on an external server. The tool generates a report recommending a set of energy upgrades and provides estimates of the potential energy savings and the net present value of performing the upgrades. With this tool, an owner can quickly determine which retrofits would work together best and provide the greatest benefit for their particular building.


Abstract
Purpose: Retinal toxicity is a common cause of drug development attrition. The aims of this research were therefore to develop the ex vivo human retina as a suitable model for the assessment of retinotoxicity, and to explore the methods in which this may be investigated.
Methods: Post mortem and living donor human eyes were obtained, and the retinas dissected within 24h post mortem or 1h enucleation respectively. The ex vivo human retina was characterised using immunohistochemistry and QRT-PCR. The effect of multiple retintoxins was investigated on the human retinal cell lines MIO-M1 (Muller cells) and ARPE19 (RPE cells), and CHQ on the human organotypic retinal culture (HORC) using the LDH and MTS assays. TUNEL, Western blotting and QRT-PCR were also used to investigate the effect of CHQ on the HORC, and CDK expression investigated by QRT-PCR.
Results: Cell specific markers were investigated in the post mortem and living donor, both possessed similar immunohistochemical and mRNA properties. CHQ was the most potent retinotoxin investigated in the cell lines, and when applied to the HORC, measureable toxicity was found along with an increase in the expression of multiple cell specific mRNA's. The expression profile of multiple CDK's in the ex vivo retina was investigated in relation to a retinotoxic Pan-CDK inhibitor, where differential expression was found. When exposed to the retinotoxic pan-CDK inhibitor, the cell lines displayed differences in toxicity.
Conclusion: The ex vivo human retina is an ideal tissue to investigate retinotoxicity. It possesses similar properties as the in vivo human retina, and displayed measureable toxicity when exposed to CHQ. The ex vivo human retina also proved its usefulness in the investigation genes associated to a novel retinotoxin. The ex vivo human retina could act as a bridge between animal and human studies, providing vital information about a drug's potential retinotoxicity.


The exponential growth of the earth's population has lead to the depletion of natural resources in concert with unrepairable environmental damage. One solution for a more sustainable lifestyle is the supply of electricity by renewable energy technology. Offshore wind energy is expected to play a major role in the extension of this sustainable energy supply. However, several challenges lay ahead due to the high expenses of offshore energy. Consequently, the optimization of a wind farm layout for minimizing costs and maximizing revenue gains high importance. This study determines the sensitivity of a wind farm layout and its revenue to wind time series length, wind direction and wind velocity trend. The sensitivity analysis is conducted at the Renewable Energy Zone (REZ) and the Rhode Island and Massachusetts Area of Mutual Interest (AMI) in Rhode Island, USA. Optimum layouts are found by minimizing an objective function expressed in terms of the Wind Farm Siting Index (WiFSI) with a Genetic Algorithm. The objective function considers wind resource, technological costs as expenses for tower foundation and cable interconnection as well as ecological and fishery cost. Ecological cost is expressed as abundance and sensitivity of species to wind farms. Fishery cost is implemented proportional to fishing activity intensity. The WiFSI is a dynamic tool adjustable by weighting factors to societal or political choices. Seven simulations are conducted for the REZ and four simulations are researched for the AMI to complete the sensitivity study. All scenarios exclude ecological and fishery constraints from the objective function to focus on effects of a changing wind resource. Simulation 1 is conducted as a base case for the REZ with constant wind resource measured over three years. Simulation 2 to 4 apply wind probability distributions of 1992 to 2012, 1980 to 2012 and 2008 to 2012, respectively. Applying the long wind time series leads to several placement solutions in contrast to one optimum layout for simulation 1. Scenario 5 and 6 apply single-year wind roses of the years 1980 and 2012. Resulting layouts differ in orientation to the respective dominant wind direction. Simulation 7 implements a positive, linear trend in usable wind velocity. The same layout as for simulation 1 is found but net revenue increases. One base case simulation with constant wind and one simulation with a positive, linear trend in the usable wind resource are operated for the Northern and the Southern part of the AMI. Optimized layouts of the base case and the trend application simulations vary. The change is due to the high number of possible turbine locations with same WiFSI. The implementation of the trend leads to an increase of net revenue. Wind turbine layout is highly sensitive to a change in wind time series length and wind direction while net revenue is less influenced. In contrast, the sensitivity of the layout to a trend in usable wind velocity is low while the effect on net revenue is significant. Conclusively, long-term wind predictions over the life time of a farm are necessary to determine the optimum layout as well as produced power of a site.


The aims of this study were to figure out the number of homographs in Acehnese and English languages and the examples of homographs. Qualitative approach was used to conduct the study. Both Acehnese dictionary and Oxford dictionary were used to collect the data. The results of the study indicated that there were 157 words found between Acehnese and English languages. In addition, those words were written in the same spelling but those are different from the meanings and pronunciation. It was clear that interlingual homograph can be found between Acehnese and English words. Keywords: Language, Acehnese, English, Homograph


This research utilised a range of deterministic and stochastic analyses to establish whether Queensland's juvenile justice system processes Aboriginal and non-Aboriginal young male offenders differently. The impetus for this research stemmed from the continued high rates of Aboriginal over-representation within Australia's criminal justice system, despite diversionary measures to reduce such over-representation, and a commitment by the Queensland Government to reduce by 50% the number of Aboriginal peoples in custody by the year 2011. There are two competing hypotheses concerning the cause of this over-representation, (i) external factors such as socioeconomic disadvantage, unemployment or substance abuse, or (ii) systemic disparity within the criminal justice system. For this research, disparity is defined as the unacceptable use of discrimination; discrimination can be appropriate if it is used to define or enhance a situation, such as discriminating between offenders who are recidivists and those who are first time offenders. The inappropriate use of discrimination occurs for example, when harsher sentences are issued to offenders based on non-legal factors such as race or gender. Systemic disparity is therefore used here to represent the inappropriate use of discrimination against an offender by the criminal justice system. The second hypothesis, one of systemic disparity, provided the framework for this research, which posed the following primary question: Is there quantifiable evidence to support the existence of disparity acting against young male Aboriginal offenders within Queensland's juvenile justice system? Two separate but complementary studies were designed to address this issue: the pathways study and the trajectory study. The pathways study utilised 20,648 finalised appearances for Aboriginal and non-Aboriginal young male offenders in Queensland's juvenile courts, during 1999 to 2003. Three custodial decision-making stages (police custody, remand, and sentencing) were examined and two questions initially posed: Does the custodial decision made at one stage of the juvenile justice system impact on a subsequent custodial decision-making stage? Does criminal history, Aboriginal status, offence type or an interaction of these factors significantly influence the probability of (i) detention in police custody (ii) court remand (iii) a custodial order at sentencing? It was recognised that other legally relevant factors such as family structure and stability, school attendance and community ties might also influence these custodial decisions; however, for the purposes of this research it was not possible to include these variables in the analyses. Controlling for criminal history, findings from logistic regression analyses indicated that being detained in police custody increased the odds of being remanded into custody, and being remanded into custody increased the odds of a custodial order. Whilst Aboriginal status was not a consistent factor at any of these three custodial stages, there was clear evidence of disparity acting against the young male Aboriginal offender, particularly early in their criminal career. To examine these disparities further, these three custodial stages were modeled as eight processing pathways: four of which resulted in a custodial order and four in a noncustodial order. Using this processing model, a third question was posed: Do young Aboriginal and non-Aboriginal male offenders have different custodial pathways? Findings indicated that Aboriginal and non-Aboriginal young male offenders were in general, processed along similar custodial pathways that did not include police custody, remand or a custodial order. However, young male Aboriginal offenders were less likely than equivalent non-Aboriginal offenders to have been processed along this pathway and more likely to be processed along the pathways that included remand. It was found that young offenders with a chronic criminal history were more likely to be processed along these remand pathways, and Aboriginal offenders were more likely to have a chronic criminal history than non-Aboriginal offenders; there was clear evidence of disparity at specific custodial stages of the system. In addition, as young male Aboriginal offenders progressed deeper into the system there was evidence of cumulative disparity, particularly along the remand pathways, meaning that the probability of being in custody increases as the offender progresses from one custodial stage to the next custodial stage. Given the existence of disparity, acting within the juvenile justice system and against the young male Aboriginal offender, it was important to formulate viable solutions to such disparity, particularly in light of the Queensland government's commitment to reduce Aboriginal offenders in custody by 50%. Deterministic analyses and computer simulations were used to test the viability of various reduction scenarios suggested by the data. Despite in some instances, different results from the deterministic analyses and the computer simulations, overall findings indicated that to reduce custodial disparity whether at the remand stage, the custodial order stage, or in custody overall (the summation of police custody, remand and custodial orders) that reducing remand, regardless of whether the young offender had been in police custody or not, was the best overall solution. The trajectory study built on the findings of the pathways study, which had identified criminal history as an important factor in the processing pathways of young male Aboriginal and non-Aboriginal offenders. Using the semi-parametric group based method, the criminal trajectories of Aboriginal and non-Aboriginal young male offenders in Queensland were modeled. These trajectories were based on the finalised appearances of two cohorts of young offenders aged 10 to 17 years of age: those born in 1983 and 1984 and who had turned 18 years of age in 2001 and 2002 respectively. All of these young male offenders had entered the adult system when they turned 17 years of age, and this data provided their complete juvenile history in Queensland. Prior analyses using this method had not considered Aboriginal status or race as a determining factor in these trajectory models, nor had these models been validated either internally or externally in published works. For this research, internal validity was considered as the correct classification of offenders into trajectory groups, and external validity as the ability to reproduce these results in a second or subsequent sample of juvenile offenders. Two questions were therefore posed in the trajectory study: Do young Aboriginal and non-Aboriginal male offenders have different criminal trajectories? Can the predicted model(s) be validated, both internally and externally? Initial findings indicated that the optimal trajectory models selected on prior knowledge and the Bayesian Information Criterion did not validate internally. This finding brought into question the trajectory results of other published works that had not internally validated their models. The models finally selected as optimal indicated that Aboriginal and non-Aboriginal young male offenders did not have a common criminal trajectory and could not be modeled as one population. Both Aboriginal and non-Aboriginal young offenders were modeled by a low-frequency group, a late-onset group, and a chronic trajectory group. However, the young male Aboriginal offender was more likely than the non-Aboriginal to have been in the chronic or the late onset group and less likely to have been in the lowfrequency group. External validation utilised an innovative but simple method that utilised all of the data in the modeling process along with a sample of this same data for validation purposes: 10% of the criminal profiles, which were characteristic of the trajectory groups, and a further 5% of randomly selected profiles were chosen for validation. All of the characteristic profiles, but only 50% of the randomly selected profiles were validated, and of the latter, the majority not validated was in the late-onset group. In total, 79.2% of the Aboriginal trajectories and 85.6% of the non-Aboriginal criminal trajectories were correctly externally validated. Overall, there are two important implications from this research for government. First, even though young male Aboriginal offenders are more likely to have a chronic criminal history than non-Aboriginal offenders, this factor does not account for all of the observed disparity acting against the young Aboriginal offender within Queensland's juvenile justice system: there is evidence of disparity within the system that is unaccounted for by either offence type or criminal history. Second, given this chronic criminal history, systemic solutions to systemic disparity whilst viable, will not ultimately resolve this problem: they are only short-term measures at the end of a very long justice system. Longer-term solutions are needed to address external factors such as socio-economic disadvantage, unemployment and substance abuse in Aboriginal communities, before these young people are exposed to the system. Continuing to concentrate on systemic solutions, to such an entrenched problem as Aboriginal overrepresentation and disparity, is a misdirection of system resources and is inconsistent with social justice.


Transposition performance differs significantly across countries and policy sectors in the EU. In this article we analyse the transposition efforts of all 27 member states with regard to four EC directives expected to create considerable difficulties for compliance at the national level. Using Cox proportional hazards regression, we find that discretion and legal fit are significant factors in explaining transposition. Furthermore, we discover that the new member states from Central and Eastern Europe are not doing any worse than the rest of the EU in terms of transposition timeliness. Surprisingly, government effectiveness has a negative relationship with compliance, while periods of absence of functioning government do not increase transposition time. Our findings emphasize the importance of legal-administrative factors for compliance with EU law.


When I was a graduate student, I discovered that the Journal of Economic Perspectives embodied much of what I love about the field of economics: the clarity that pierces rhetoric to seek the core of a question; the rigor to identify the causal relationships, tradeoffs, and indeterminancies inherent in a problem; the self-assurance to apply the disciplinary toolkit to problems both sacred and profane; and the force of logic to reach conclusions that might be unexpected, controversial, or refreshingly bland. It never occurred to me in those years that one day I would edit the journal. While doing so is a privilege and a pleasure, I equally confess that it's no small weight to be the custodial parent of one of our profession's most beloved offspring. No less intimidating is the task of stipulating what this upstart youth has accomplished in its first 25 years and 100 issues in print. Like any empiricist, I recognize that the counterfactual world that would exist without the JEP is unknowable, but my strong hunch is that our profession would be worse off in that counterfactual world. In this essay, I reflect on the journal's accomplishments and articulate some of my own goals for the JEP going forward.


Reconfigurable logic or Field-Programmable Gate Array (FPGA) devices have the ability to dynamically adapt the computational circuit based on user-specified or operating-condition requirements. Such hardware platforms are utilized in this dissertation to develop adaptive techniques for achieving reliable and sustainable operation while autonomously meeting these requirements. In particular, the properties of resource uniformity and in-field reconfiguration via on-chip processors are exploited to implement Evolvable Hardware (EHW). EHW utilize genetic algorithms to realize logic circuits at runtime, as directed by the objective function. However, the size of problems solved using EHW as compared with traditional approaches has been limited to relatively compact circuits. This is due to the increase in complexity of the genetic algorithm with increase in circuit size. To address this research challenge of scalability, the Netlist-Driven Evolutionary Refurbishment (NDER) technique was designed and implemented herein to enable on-the-fly permanent fault mitigation in FPGA circuits. NDER has been shown to achieve refurbishment of relatively large sized benchmark circuits as compared to related works. Additionally, Design Diversity (DD) techniques which are used to aid such evolutionary refurbishment techniques are also proposed and the efficacy of various DD techniques is quantified and evaluated. Similarly, there exists a growing need for adaptable logic datapaths in custom-designed nanometerscale ICs, for ensuring operational reliability in the presence of Process, Voltage, and Temperature (PVT) and, transistor-aging variations owing to decreased feature sizes for electronic devices. Without such adaptability, excessive design guardbands are required to maintain the desired integration and performance levels. To address these challenges, the circuit-level technique of SelfRecovery Enabled Logic (SREL) was designed herein. At design-time, vulnerable portions of the circuit identified using conventional Electronic Design Automation tools are replicated to provide post-fabrication adaptability via intelligent techniques. In-situ timing sensors are utilized in a feediii back loop to activate suitable datapaths based on current conditions that optimize performance and energy consumption. Primarily, SREL is able to mitigate the timing degradations caused due to transistor aging effects in sub-micron devices by reducing the stress induced on active elements by utilizing power-gating. As a result, fewer guardbands need to be included to achieve comparable performance levels which leads to considerable energy savings over the operational lifetime. The need for energy-efficient operation in current computing systems has given rise to NearThreshold Computing as opposed to the conventional approach of operating devices at nominal voltage. In particular, the goal of exascale computing initiative in High Performance Computing (HPC) is to achieve 1 EFLOPS under the power budget of 20MW. However, it comes at the cost of increased reliability concerns, such as the increase in performance variations and soft errors. This has given rise to increased resiliency requirements for HPC applications in terms of ensuring functionality within given error thresholds while operating at lower voltages. My dissertation research devised techniques and tools to quantify the effects of radiation-induced transient faults in distributed applications on large-scale systems. A combination of compiler-level code transformation and instrumentation are employed for runtime monitoring to assess the speed and depth of application state corruption as a result of fault injection. Finally, fault propagation models are derived for each HPC application that can be used to estimate the number of corrupted memory locations at runtime. Additionally, the tradeoffs between performance and vulnerability and the causal relations between compiler optimization and application vulnerability are investigated.


The engineering hypothesis is that a hypertext-like, collaborative authoring system can provide an appropriate infrastructure for a knowledge and workflow management system. A hierarchical, hypertext infrastructure with typed, multi-attributed nodes provides the platform. People perform their scheduled activities by creating nodes in the system and they comment on one another's work. Such a system has been designed and built, as documented here. The engineering result suggests new issues for the design of the next generation of the system. The experimental hypothesis is that people will use such a system to manage knowledge and work. Knowledge management has been successfully supported in a software engineering team. Workflow management was only partly supported for these software engineers in part because they often relied on informal working methods that did not match well the scheduling capabilities of the system.


A wastewater-treatment flowsheet was developed to integrate uniquely designed biological processes with physical-chemical unit processes, allowing conversion of the organic carbon in the wastewater to methane, the removal and recovery of phosphorus and nitrogen from the wastewater, and the production of water suitable for reuse. In the flowsheet, energy is derived from the wastewater by first shunting a large fraction of the organic carbon in the wastewater to a solids slurry which is treated via anaerobic digestion. The anaerobic digestion system consists of focused pulsed (FP) pretreatment coupled to anaerobic membrane bioreactors (MBRs). Computer modelling and simulation results are used to optimize design of the system. Energy generation from the system is maximized and costs are reduced by using modest levels of recycle flow from the anaerobic MBRS to the FP pretreatment step.


An experiment was conducted to determine the foraging behavior of Apis mellifera L. and Apis cerana F. in rapeseed under cage condition in Chitwan, Nepal during 2012-2013. This experiment showed that Apis cerana F. foraged extra 42 minute per day as compared to Apis mellifera L. Apis cerana F. were more attracted to nectar, whereas Apis mellifera L. were more attracted to pollen collection throughout the day. The activities, in into hives and out from hives, for both species were recorded more at 2:00 pm and least at 8:00 am. The highest in-out were observed at 2:00 pm on both species as Apis mellifera L. 44.33 bees entered into hives and 49.66 bees went out of hives, whereas lower number of Apis cerana F. 43.66 bees entered into hives and 48.16 bees were out of hives. Apis mellifera L. collect 1.22:1 and 0.41:1 pollen nectar ratio at 10:00 am and 4:00 am whereas at same hours Apis cerana collect 1.16:1 and 0.30:1 pollen nectar ratio. Apis cerana F. foraged significantly higher number of rapeseed flowers and plants as compared to Apis mellifera L. under caged condition. It shows that Apis cerana F. was more efficient pollinator as compared to Apis mellifera L. under caged condition.


A laser-based ultrasonic system for non-contact and non-destructive measurement of the elastic properties of paper was demonstrated on a paper manufacturing machine during commercial operation with paper moving around 20 m/s. We believe this to be the highest sample traveling speed reported to date for a commercial application of laser ultrasonics. Ultrasonic waves were generated in the paper with a pulsed Nd:YAG laser at 1064 nm wavelength and detected with a Mach-Zehnder interferometer coupled with a scanning mirror/timing system to compensate for paper motion. Measurements of the flexural rigidity (FR) and out-of-plane shear rigidity (SR) of the paper web were done automatically by fitting the frequency dependence of the phase velocity of Ao mode Lamb waves to a model wave propagation equation. Variation in FR and SR across the width of the paper sheet (cross-direction profiles), effects of changes in paper manufacturing process variables on measured FR and SR, comparisons with traditional mechanical stiffness tests are presented. The sensor head is fully optical and thus measures the web properties without any contact. This laser-ultrasonics system combines a very reasonable cost with a relatively small footprint and low power consumption due to the low power output of the lasers that are used. Finally, laboratory data indicate that this technology is directly transferable to measurements on sheet metals and possibly other opaque web materials


This paper will critique and reflect upon a small research project that was designed to explore the effectiveness, for both students and lecturers alike, of employing wikis as learning tools in first year seminars.

It will begin by very briefly outlining the project, the participants, the module content, the assessment strategy, and the way in which wikis were employed. It will then summarise the data collected and will indicate how the data might be interpreted. The remainder of the paper will reflect upon the impact of the employment of wikis in this instance, and will suggest ways in which they might more fruitfully be employed in the future.

What will be seen is that there is a direct correlation between student engagement with the technology and student performance in the final, traditional assessments. Whilst it cannot be assumed that the wikis directly contributed to the students' performance, it seems reasonable to suggest that student propensity for engagement with the technology is a contributory factor towards success on the final assessment. With this in mind, it seems that, through engaging students in work on the wiki pages, their assessment performance might be enhanced.

It will thus be argued that engagement in an online collaborative writing/creative project is conducive towards heightened student achievement. The final section of this paper will hypothesise as to why such a correlation exists between wiki activity and assessment performance. In moving towards a conclusion, reference will be made to various theories of identity, including Communities of Practice, and Cultural-Historical Activity Theory.


Focused ion beam milling is a processing technology which allows flexible direct writing of nanometer scale features efficiently substituting electron beam lithography. No mask need results in ability for patterns writing even on fragile micromechanical devices. In this work we studied the abilities of the tool for fabrication of diffraction grating couplers in silicon nitride waveguides. The gratings were fabricated on a chip with extra fragile cantilevers of sub micron thickness. Optical characterization of the couplers was done using excitation of the waveguides in visible range by focused Gaussian beams of different waist sizes. Influence of Ga+ implantation on the device performance was studied.


BACKGROUND 5-aminolevulinic acid (5-ALA)–induced fluorescence of neoplastic tissue is known to occur in a number of high-grade gliomas. This fluorescence helps surgeons maximize safe resection by distinguishing previously indiscernible neoplastic tissue from brain parenchyma. Still, the effectiveness of 5-ALA has not been fully explored for all central nervous system tumors. Consequently, the full spectrum of tumors that would benefit from fluorescence-guided surgery using 5-ALA is unknown. OBSERVATIONS This report describes successfully utilizing 5-ALA to achieve complete resection of a recurrent anaplastic pleomorphic xanthoastrocytoma (APXA). LESSONS APXA tumor cells accumulate sufficient amounts of 5-ALA and its fluorescent metabolite to produce visible intraoperative fluorescence. However, further investigation is needed to determine if 5-ALA fluorescent labeling routinely occurs in patients with APXAs.


Mechanical ventilation is one of the most commonly applied interventions in intensive care units. Despite its life-saving role, it can be a risky procedure for the patient if not applied appropriately. To decrease risks, new ventilator modes continue to be developed in an attempt to improve patient outcomes. Advances in ventilator modes include closed-loop systems that facilitate ventilator manipulation of variables based on measured respiratory parameters. Adaptive support ventilation (ASV) is a positive pressure mode of mechanical ventilation that is closed-loop controlled, and automatically adjust based on the patient's requirements. In order to deliver safe and appropriate patient care, clinicians need to achieve a thorough understanding of this mode, including its effects on underlying respiratory mechanics. This article will discuss ASV while emphasizing appropriate ventilator settings, their advantages and disadvantages, their particular effects on oxygenation and ventilation, and the monitoring priorities for clinicians.


Recently, the prediction of the dynamical behavior of Liquid Diffusion Phenomenon (LDP) has been used in many applications especially in physical and biological fields. Many models have been proposed to predict the LDP behavior, but most of them require complex mathematical calculations causing computation time consumption. This thesis proposes a dynamical behavior prediction algorithm using Cellular Automata (CA) to model the LDP. A real liquid diffusion phenomenon is recorded whereas the observed images are later extracted for comparing purpose with the predicted phenomenon. First, a mathematical method is proposed in order to track and then analyze the real diffusion behavior. This method has used thousands of original images. Then, thousands of images, as the same number of original images, are created by the CA-based algorithm. In this study, the diffusion speed of the predicted LDP is also computed by using a mathematical proposed algorithm which is the Diffusion Speed Algorithm (DSA). Finally, three benchmark strategies are used in order to compare the predicted images to the original images, which are:pixel intensity, Region-of-Diffusion (ROD) area, and ROD shape. The experiments of this thesis are divided into original and predicted images. The original images are classified into three groups based on the temperature used, which are: ±18 °C, ±24 °C, and ±30 °C. Each temperature-based experiment contains five levels of the height of droplets source. The diffusion time has been equal to 32 seconds with 15 fps comprising 480 images per each experiment. On the other hand,the predicted images are similarly classified. There will be 15 predicted experiments created by the proposed CA algorithm. The whole predicted images are compared to their corresponding original ones. Under the experiments samples, there are 30 processed experiments comprising 14400 original and predicted images. The obtained results show that the averaged similarity percentage is equal to 94.4%. Additionally,the average computation time needed to complete processing a single experiment is 1.3 second. The result obtained from the proposed LDP model compared to other competitive LDP models has higher accuracy and less computation time. The results also show that the proposed LDP model is about 15 times faster than a neural network-based model. A detailed study to explore the effects and relationships between the model"s parameters such as temperature and liquids" viscosity has been performed. The results showed that there is a direct relationship between the temperature and the diffusion speed.


The discovery that trypanosomatids, unicellular organisms of the order Kinetoplastida, are capable of synthesizing prostaglandins raised questions about the role of these molecules during parasitic infections. Multiple studies indicate that prostaglandins could be related to the infection processes and pathogenesis in trypanosomatids. This work aimed to unveil the role of the prostaglandin F2α synthase TcOYE in the establishment of Trypanosoma cruzi infection, the causative agent of Chagas disease. This chronic disease affects several million people in Latin America causing high morbidity and mortality. Here, we propose a prokaryotic evolutionary origin for TcOYE, and then we used in vitro and in vivo experiments to show that T. cruzi prostaglandin F2α synthase plays an important role in modulating the infection process. TcOYE overexpressing parasites were less able to complete the infective cycle in cell culture infections and increased cardiac tissue parasitic load in infected mice. Additionally, parasites overexpressing the enzyme increased PGF2α synthesis from arachidonic acid. Finally, an increase in benznidazole and nifurtimox susceptibility in TcOYE overexpressing parasites showed its participation in activating the currently anti-chagasic drugs, which added to its observed ability to confer resistance to hydrogen peroxide, highlights the relevance of this enzyme in multiple events including host–parasite interaction.


Purpose The benefits of thrombolytic treatment are time-dependent. We developed a smartphone application that aids stroke patient self-screening and hospital selection, and may also decrease hospital arrival time. Materials and Methods The application was developed for iPhone and Android smartphones. Map data for the application were adopted from the open map. For hospital registration, a web page (http://stroke119.org) was developed using PHP and MySQL. Results The Stroke 119 application includes a stroke screening tool and real-time information on nearby hospitals that provide thrombolytic treatment. It also provides information on stroke symptoms, thrombolytic treatment, and prescribed actions when stroke is suspected. The stroke screening tool was adopted from the Cincinnati Prehospital Stroke Scale and is displayed in a cartoon format. If the user taps a cartoon image that represents abnormal findings, a pop-up window shows that the user may be having a stroke, informs the user what to do, and directs the user to call emergency services. Information on nearby hospitals is provided in map and list views, incorporating proximity to the user's location using a Global Positioning System (a built-in function of smartphones). Users can search for a hospital according to specialty and treatment levels. We also developed a web page for hospitals to register in the system. Neurology training hospitals and hospitals that provide acute stroke care in Korea were invited to register. Seventy-seven hospitals had completed registration. Conclusion This application may be useful for reducing hospital arrival times for thrombolytic candidates.


This paper presents the case of a six year-old, male, thoroughbred horse with clinical signs of inappetence, weakness, and incoordination when walking. Clinical examination showed that the horse staggered and leaned to the left side. Feedstuff was present inside and around its mouth. Salivation was increased and there was no reflex at the palpebrae and tongue. The horse had difficulty swallowing and the tone of its tail was reduced. Botulism was diagnosed based on the clinical signs. Antibiotic (ceftiofur) and fluid-electrolyte treatment was commenced. Next day, neostigmin was added to the horse's treatment, and it became recumbent. The horse's palpebral, tongue and tail reflexes returned partially after neostigmine methylsulphate treatment on the same day and it stood up on day four. However, it could not swallow anything during the whole week, so after getting permission from the owner, the horse was euthanized on day 10. Samples of the colonic content and blood serum were sent by courier to the laboratory for toxin neutralization, however, botulinum neurotoxins could not be detected. After that, serum samples from days 6 and 10 were sent to another laboratory for testing for botulinum neurotoxin antibodies by ELISA. Specific antibodies against botulinum neurotoxin type A were measured, indicating a previous, immuno-relevant contact with the toxin. This seroconversion for type A supports the clinical botulism diagnosis. Type A botulism is rarely seen in Europe and has been detected in a horse in Turkey for the first time. Equine, Clostridium botulinum, botulinum neurotoxin, Turkey


Passwords are still the most widespread means for authenticating users, even though they have been shown to create huge security problems. This motivated the use of additional authentication mechanisms used in so-called multi-factor authentication protocols. In this paper we define a detailed threat model for this kind of protocols: while in classical protocol analysis attackers control the communication network, we take into account that many communications are performed over TLS channels, that computers may be infected by different kinds of malwares, that attackers could perform phishing, and that humans may omit some actions. We formalize this model in the applied pi calculus and perform an extensive analysis and comparison of several widely used protocols — variants of Google 2-step and FIDO's U2F. The analysis is completely automated, generating systematically all combinations of threat scenarios for each of the protocols and using the P ROVERIF tool for automated protocol analysis. Our analysis highlights weaknesses and strengths of the different protocols, and allows us to suggest several small modifications of the existing protocols which are easy to implement, yet improve their security in several threat scenarios.


There is widespread evidence of failure to implement health interventions that have been demonstrated to be cost-effective by high-quality research; this failure affects both high-income and low-income countries. Low-income countries face additional challenges to using research evidence including: the weakness of their health systems, the lack of professional regulation and a lack of access to evidence. There is a need to strengthen institutions and mechanisms that can more systematically promote interactions between researchers, policy-makers and other stakeholders who can influence the uptake of research findings. The concept of public engagement with health research requires a public that is both informed and active. Even when systematic reviews are available further work is needed to translate their findings into guidelines or messages that are understandable to patients and health professionals. Many of the commonly used approaches for keeping health professionals' knowledge up-to-date appear to have small or inconsistent effects. The evidence-base is more extensive for interventions directed towards professionals, such as education, reminders or feedback, than for those directed at organizations or patients. The effect of interventions varies according to the setting and the behaviour that is targeted. Case studies in low-income settings suggest that some strategies can result in increased coverage of evidence-based interventions, but there is a lack of evidence from systematic reviews of rigorous research. Given the potential for near-term improvements in health, finding more effective ways of promoting the uptake of evidence-based interventions should be a priority for researchers, practitioners and policy-makers.


Learning composable policies for environments with complex rules and tasks is a challenging problem. We introduce a hierarchical reinforcement learning framework called the Logical Options Framework (LOF) that learns policies that are satisfying, optimal, and composable. LOF efficiently learns policies that satisfy tasks by representing the task as an automaton and integrating it into learning and planning. We provide and prove conditions under which LOF will learn satisfying, optimal policies. And lastly, we show how LOF's learned policies can be composed to satisfy unseen tasks with only 10-50 retraining steps. We evaluate LOF on four tasks in discrete and continuous domains, including a 3D pick-and-place environment.


Summary It is still unclear if and how biological factors contribute to excess male mortality due to 'external causes' (accidents, injuries, homicides and suicides). Sex hormones and reproductive roles are supposed to drive sex differences in behaviours increasing the male external cause mortality risk. This study analyses the external cause mortality of Catholic nuns and monks from three Bavarian cloisters whose similar environments allow the impact of biological factors to be isolated from a number of confounding causes. Using obituaries, entries in the profession books of religious orders and cemetery registers 2533 deaths of nuns and monks could be linked to a specific cause of death for the years 1946–2005, of which 69 belong to the group of external cause deaths. External cause mortality of the Bavarian cloistered and the West German general population has been compared by means of standardized mortality rates (SMRs) for ages 45 onwards using the European age standard for the age groups 45–64, 65–74 and 75+. Whereas nuns show statistically significantly lower external cause mortality than the general female population, monks' external cause mortality parallels or even exceeds that of general population males. These findings contradict the reproductive role hypothesis and provide some evidence for the sex hormones hypothesis.


Objective: Previous research using electropalatography (EPG) identified a compensatory articulation called bilabial-lingual double articulations. These double articulations were produced for bilabials by some speakers with cleft palate and involved closure at the lips occurring simultaneously with complete tongue-palate constriction. However, no normative English EPG data exist to confirm the abnormal status of these double articulations. Design: This study reports normative data for EPG contact during bilabial closure. Acoustic and EPG data were recorded for bilabials in different vowel contexts. Participants: Eight normal English-speaking adults. Measures: One measure identified complete tongue-palate constriction, and a second measure calculated percent contact. Results: There were no instances of complete tongue-palate constriction, though some EPG contact occurred in the lateral regions of the palate. The vowel context significantly affected the amount of contact present, with /i/ having the most and /a/ having the least amount of contact. Conclusion: Complete tongue-palate constriction during bilabials of the type found in bilabial-lingual double articulations is not a feature of normal English speech and can therefore be considered an abnormal articulation pattern. Speech-language pathologists who use EPG in their clinical work should be aware that some lateral contact during bilabial closure is normal.


Abstract. Branch enclosure based emission rates of monoterpenes and sesquiterpenes from four Scots pines ( Pinus sylvestris ) and one Norway spruce ( Picea abies ), as well as the ambient mixing ratios of monoterpenes were determined during the HUMPPA-COPEC 2010 summer campaign. Differences in chemical composition and in emission strength were observed between the different trees, which confirmed that they represented different chemotypes. The chemotypes of Scots pine can be classified according to species with high, no and intermediate content of Δ-3-carene. The "non-Δ-3-carene" chemotype was found to be the strongest emitter of monoterpenes. From this chemotype, β-myrcene, a very reactive monoterpene, was the dominant species accounting for more than 32 % of the total emission rates of isoprenoids followed by β-phellandrene (~27%). Myrcene fluxes ranged from 0.8 to 24 μg g −1 (dw) h −1 . α-Farnesene was the dominant sesquiterpene species, with average emission rates of 318 ng g −1 (dw) h −1 . In the high Δ-3-carene chemotype, more than 48% of the total monoterpene emission was Δ-3-carene. The average Δ-3-carene emission rate (from chemotype 3), circa 609 ng g −1 (dw) h −1 reported here is consistent with the previously reported summer season value. Daily maximum temperatures varied between 20 and 35 °C during the measurements. The monoterpene emissions from spruce were dominated by limonene (35%), β-phellandrene (15%), α-pinene (14%) and eucalyptol (9%). Total spruce monoterpene emissions ranged from 0.55 up to 12.2 μg g −1 (dw) h −1 . Overall the total terpene flux (monoterpenes + sesquiterpenes) from all studied tree species varied from 230 ng g −1 (dw) h −1 up to 66 μg g −1 (dw) h −1 . Total ambient monoterpenes (including α-pinene, Δ-3-carene, β-pinene and β-myrcene) measured during the campaign varied in mixing ratio from a few pptv to over one ppbv. The most abundant biogenic VOC measured above the canopy were α-pinene and Δ-3-carene, and these two compounds together contributed more than 50% of the total monoterpenes. The ambient data reflect the emission rate, atmospheric reactivity and tree type abundance. The diel cycles of isoprenoid mixing ratios showed high levels during the night-time which is consistent with continued low nocturnal emission and a low and stable boundary layer. The chirality of α-pinene was dominated by (+)-enantiomers both in the direct emission and in the atmosphere. The two highest emitters showed no enantiomeric preference for α-pinene emissions, whereas the two lowest emitting pines emitted more (+)-enantiomer. The spruce emissions were dominated by (−)-enantiomer. The exceptionally hot temperatures in the summer of 2010 led to relatively strong emissions of monoterpenes, greater diversity in chemical composition and high ambient mixing ratios.


On 15-16 November 1989, I attended the Massachusetts Institute of Technology (MIT) Industrial Liaison Program entitled "Networks and Learning." The topic was neural networks, their power, potential, and promise. A dozen distinguished professors and researchers presented informative and entertaining talks to an audience of technically minded business executives and industrial researchers who subscribe to MIT's popular series of symposia offered through their Industrial Liaison Program. This informal report encapsulates the two-day event with a brief summary of each talk.


In this vivid memoir of a life in science, ecologist Paul Colinvaux takes his readers from the Alaskan tundra to steamy Amazon jungles, from the Galapagos Islands (before tourists had arrived) to the high Andes and the Darien Gap in Panama. He recounts an adventurous tale of exploration in the days before GPS and satellite mapping, and a tale no less exhilarating of his battle to disprove a hypothesis endorsed by most of the scientific community. Colinvaux's grand endeavor, begun in the 1960s, was to find fossil evidence of the ice-age climate and vegetation of the entire American equator, from Pacific to Atlantic. The accomplishment of the task by the author and his colleagues involved finding unknown ancient lakes, lugging drilling equipment through uncharted Amazon jungle, operating hand drills from rubber boats in water 40 meters deep, and inventing a pollen analysis for a land with 80,000 species of plants. Colinvaux's years of arduous travel and research ultimately disproved a hotly defended hypothesis explaining bird distribution peculiarities in the Amazon forest. The story of how he arrived at a new understanding of the Amazon is at once an adventurous saga, an account of science as it is conducted in the field, and a cautionary tale about the temptation to treat a favored hypothesis with a reverence that subverts unbiased research.


The international literature on M&As is extensive, but surprisingly little evidence exists for the Nordic countries. This article attempts to fill the gap by studying 184 merger announcements from 1995 to 2014. Our findings differ in a number of ways. "First, we extend the current literature since we find that diversifying acquisitions" generate a higher bidder abnormal return compared with focused transactions. A possible explanation is that in diversifying acquisitions acquirers overpay for target firms within their core industry because they overestimate operational synergies. The managerial implication is that the notion of core business should not restrict diversified value-enhancing M&As. Secondly, we find evidence that bidder abnormal returns depend not on the method of payment. The implication is that bidders may have more flexibility with regard to the financing of deals in the Nordic countries, because the acquirer's managers do not have to take into account any negative market reactions with regard to the payment method. Thirdly, we explore the relationship between cash flows and abnormal returns. Our results confirm current literature since we find that low-valued bidders with excessive free cash flows experience negative returns prior to an announcement. Furthermore, our results imply that a bidder company must be able convincingly to justify an acquisition to the market by communicating the presence of a sound and coherent integration plan.


Abstract A novel machine learning approach for nuclear power plant modeling and state identification is presented together with its test results using data from the Loss-of-Fluid Test experimental facility. The approach exploits Gaussian processes whose principal function is to tackle the temporal problem of forecasting the actual system state in the varying environment of a nuclear reactor facility that undergoes successive overcooling transients. The approach fuses independent Gaussian process expert predictions to provide a single recommendation to the plant operators in a form that is suitable to appear on a decision support system screen. A variety of test cases are developed to explore the validity and relevance of Gaussian processes. The proposed implementation is examined with various predictor variables under different conditions, and the results obtained are in accordance with model expectations.


Posttranslational modification by N-acetylglucosamine (O-GlcNAc) has been reported for several proteins involved in the regulation of transcription. Gewinner et al. show that several members of the STAT family of transcription factors (STAT5, STAT1, STAT3, and STAT6) were modified by the addition of O-GlcNAc in response to cytokine, hormone, or growth factor stimulation of HC11 mouse mammary epithelial cells (different STATs are activated by different ligands). STAT5a glycosylation was explored in more detail. Glycosylation was stimulated by prolactin treatment of the cells, and glycosylated STAT5a was more abundant in the nucleus than in the cytoplasm. Glycosylation of STAT5 did not influence tyrosine or serine phosphorylation or DNA-binding ability. Mutation of Thr92 substantially diminished glycosylation of STAT5, although it did not impair phosphorylation or DNA binding. The T92A mutant did not stimulate reporter gene expression in transfected cells. In vitro, STAT5 only interacted with the transcriptional coactivator CBP when glycosylated. However, glycosylation status did not affect STAT5's interaction with several other cofactors. Thus, dynamic glycosylation may contribute to the activation of STAT-regulated genes by controlling interaction with a subset of cofactors. C. Gewinner, G. Hart, N. Zachara, R. Cole, C. Beisenherz-Huss, B. Groner, The coactivator of transcription CREB-binding protein interacts preferentially with the glycosylated form of Stat5. J. Biol. Chem. 279, 3563-3572 (2004). [Abstract] [Full Text]


This paper derives intuitive and empirically useful formulas for the optimal pricing of passenger transit and for the welfare effects of adjusting current fare subsidies, for peak and off-peak urban rail and bus systems. The formulas are implemented based on a detailed estimation of parameter values for the metropolitan areas of Washington (D.C.), Los Angeles, and London. Our analysis accounts for congestion, pollution, and accident externalities from automobiles and from transit vehicles; scale economies in transit supply; costs of accessing and waiting for transit service as well as service crowding costs; and agency adjustment of transit frequency, vehicle size, and route network to induced changes in demand for passenger miles. The results support the efficiency case for the large fare subsidies currently applied across mode, period, and city. In almost all cases, fare subsidies of 50 percent or more of operating costs are welfare improving at the margin, and this finding is robust to alternative assumptions and parameters.


Background: Different light curing units are used in the dental clinic, and they may produce different hardness values on the surface of resinmodified glass ionomer cements (RMGICs). The purpose of this study was to assess surface hardness of a nanofilled (KetacTM N100 - 3M/ESPE) and three commonly used RM GICs (VitremerTM- 3M/ESPE, Vitro Fil LC® - DFL, Resiglass® - Biodinamica) using two different light curing systems: quartz tungsten halogen (QTH) and light-emitting diode (LED).
Methods: Sixteen specimens of each material were made according to manufacturer's instructions, inserted in disc-shaped molds (o6mm; 2mm thick). The half (eight specimens) of each material were light cured using halogen light - Optilux 401, Demetron or LED- LEDemetron I, Kerr) for 20 seconds, with exception of Vitremer (40 seconds). The specimens were stored in artificial saliva for 24h, at 37oC. The surfaces were wet polished. Five Knoop Hardness Number (KHN) measurements were taken from on the upper surface with 25 g load and 30s dwell time with a Knoop indentator each sample and 7 days after.
Results: The means of KHN after 7 days were (QTH; LED), respectively: Vitremer (44.12; 40.68); N100 (35.14; 29.02); Vitro Fill LC (29.10; 30.71); Resiglass (37.90; 26.80). Vitremer showed significantly higher KHN values. No significant difference was found between the KHN in relation to light unit.
Conclusions: The type of light source has no influence on surface hardness of RM GICs.


A method of automated design of complex, modular robots involves an evolutionary process in which generative representations of designs are used. The term generative representations as used here signifies, loosely, representations that consist of or include algorithms, computer programs, and the like, wherein encoded designs can reuse elements of their encoding and thereby evolve toward greater complexity. Automated design of robots through synthetic evolutionary processes has already been demonstrated, but it is not clear whether genetically inspired search algorithms can yield designs that are sufficiently complex for practical engineering. The ultimate success of such algorithms as tools for automation of design depends on the scaling properties of representations of designs. A nongenerative representation (one in which each element of the encoded design is used at most once in translating to the design) scales linearly with the number of elements. Search algorithms that use nongenerative representations quickly become intractable (search times vary approximately exponentially with numbers of design elements), and thus are not amenable to scaling to complex designs. Generative representations are compact representations and were devised as means to circumvent the above-mentioned fundamental restriction on scalability. In the present method, a robot is defined by a compact programmatic form (its generative representation) and the evolutionary variation takes place on this form. The evolutionary process is an iterative one, wherein each cycle consists of the following steps: 1. Generative representations are generated in an evolutionary subprocess. 2. Each generative representation is a program that, when compiled, produces an assembly procedure. 3. In a computational simulation, a constructor executes an assembly procedure to generate a robot. 4. A physical-simulation program tests the performance of a simulated constructed robot, evaluating the performance according to a fitness criterion to yield a figure of merit that is fed back into the evolutionary subprocess of the next iteration. In comparison with prior approaches to automated evolutionary design of robots, the use of generative representations offers two advantages: First, a generative representation enables the reuse of components in regular and hierarchical ways and thereby serves a systematic means of creating more complex modules out of simpler ones. Second, the evolved generative representation may capture intrinsic properties of the design problem, so that variations in the representations move through the design space more effectively than do equivalent variations in a nongenerative representation. This method has been demonstrated by using it to design some robots that move, variously, by walking, rolling, or sliding. Some of the robots were built (see figure). Although these robots are very simple, in comparison with robots designed by humans, their structures are more regular, modular, hierarchical, and complex than are those of evolved designs of comparable functionality synthesized by use of nongenerative representations.


Safety is very important to everyone, especially when it comes to packaging of food and non-food items. This research aims to make hydrophobic paper from wax of taro leaves and chitin from crab shells. The physical properties (color, odor, texture, tensile strength, thickness, density, solubility, liquid dropping) and chemical properties (ash content, pH, moisture content) of the formulated hydrophobic paper were compared to the properties of commercial photographic paper. Fourier Transformed Infrared (FTIR) was also used to determine functional groups present in the paper. The prepared hydrophobic paper is dirty white in color, has a pleasant odor, rough texture, can withstand mass of 92 g, about 1.45 mm thickness, and has a density of 0.071g/mL Liquids (like soy sauce, vinegar and water) cannot pass through except cooking oil. It is insoluble in water, hexane and dilute NaOH but slightly soluble in HCl. Physical properties of the hydrophobic paper was found better than photographic paper except for its dirty white color due to the pigment of leaves that was present in wax from taro leaves and its rough texture. The chemical properties showed that the hydrophobic paper has a longer life than that of commercial photographic paper because it has a lower moisture content and has a pH of 8.2 which means that it is basic, and basic papers has longer shelf life than acidic papers. FTIR result showed that the hydrophobic paper has an alkane group.


The International Law Reports endeavour to provide within a single series of volumes comprehensive access in English to judicial materials bearing on public international law. On certain topics it is not always easy to draw a clear line between cases which are essentially ones of public international law interest and those which are primarily applications of special domestic rules. For example, in relation to extradition, the Reports will include cases which bear on the exception of "political offences" or the rule of double criminality, but will restrict the number of cases dealing with purely procedural aspects of extradition. Similarly, while the general rules relating to the admission and exclusion of aliens, especially of refugees, are of international legal interest, cases on the procedure of admission usually are not. In such borderline areas, and sometimes also where there is a series of domestic decisions all dealing with a single point in essentially the same manner, only one illustrative decision will be printed and references to the remainder will be given in an accompanying note.


Replication of routines and capabilities has been largely neglected in recent research. In this paper we present the current state of research on replication and suggest conceptualizing replication as a social practice. Replication as a social practice goes beyond knowledge transfer between a replicator and a replicatee and involves how routines and capabilities as well as the process of replication itself are constructed and shaped by multiple actors in the organization. Moreover, this perspective acknowledges the role of artefacts in the process of replication. Based on recent literature on routines and organizational rules we differentiate replication into three interrelated sub-practices: rule (re-) creation, rule translation and rule performance. The theoretical framework suggested in this paper has several significant theoretical implications for research on replication. In addition, we point out important research design implications for future empirical research.


In a composite of two dissimilar or homologous semiconductors with different energy band gaps or metal/semiconductor composites, we expect a band bending effect at the interfaces. The band bending effect induced by the different Fermi levels of two compounds can selectively scatter carriers due to energy-dependent scattering time, resulting in enhancement of the Seebeck coefficient. In addition, nano-inclusions in a matrix will effectively scatter phonons. Here, we demonstrate the effects of electron and phonon scattering by nano-inclusions in n-type (PbTe0.93−xSe0.07Clx)0.93(PbS)0.07 (x = 0.0005, 0.01, 0.1 and 0.2) composites. In the matrix, the nano-inclusions increased the Seebeck coefficient while reducing lattice thermal conductivity in (PbTe0.93−xSe0.07Clx)0.93(PbS)0.07. The chlorine doping increases the Fermi level to the bottom of the conduction band giving rise to increased electron concentration. The simultaneous emergence of the high Seebeck coefficient and low thermal conductivity resulted in the exceptional ZT value of 1.52 at 700 K for low chlorine doping (x = 0.0005), which is a very high value in n-type thermoelectric materials. The randomly distributed interface potential, induced by Fermi level tuning, with nano-inclusions is a new criterion for investigating thermoelectric properties.


Hydrogen peroxide (H2O2) is widely used in many biological systems and industrial processes in the textile, food, pharmaceutical and clinical sectors. The importance of hydrogen peroxide is related to its unique oxidising properties as well as decomposition, which plays a very important role in the manufacture of industrial water electrolysers, secondary metal-air batteries and fuel cells. Therefore, the accurate and rapid determination of H2O2 is extremely important.
Electrochemical H2O2 sensors are shown to be an appropriate alternative to the traditional methods (titrimetry, spectrophotometry and chemiluminescence) because they are rapid, low cost and easy for automation detection. Many metal materials such as Pt, Pd, Cu and Ag have been used as electrodes for the electrochemical determination of H2O2.[1] Recently, an improvement of the catalytic activity of silver screen-printed electrodes towards H2O2 reduction after electrode modification with a mixed surfactant/salt solution has been reported.[2] The combination of dodecyl benzenesulphonic acid and KCl led to changes in both the morphology and chemical composition of the silver paste electrode surface which enhanced the reduction of H2O2 at -0.1 V vs. Ag/AgCl up to 80-fold on such material.
In the present work, this phenomenon is further investigated with regard to the effect the type of metal electrode, surfactant and salt have on the reduction of H2O2. Silver paste electrodes were modified with a range of surfactants (dodecylbenzenesulfonic acid, sodium dodecyl sulphate, cetyl trimethylammonium bromide, Triton X-100) and chloride salts and their ability to reduce H2O2 was evaluated. The effect of the modification on the H2O2 reduction was assessed by cyclic voltammetry and amperometry. Scanning Electron Microscopy (SEM) measurements were performed to characterize the electrode surfaces before and after the surfactant-based modification. In addition, the surfactant/salt modifications were performed on a range of metallic substrates such as Au, Pt and other Ag-based electrodes. Comparisons of H2O2 reduction at these electrodes are shown and the effect of their modifications is also studied.


The fundamental notion that increased ties to the polity of the United States would entitle an alien to better rights is deeply-rooted in the jurisprudence. Ordinarily, these rights tend to strengthen as one moves forward from the beginning of the spectrum, which might involve the most attenuated contact, as in the case of enemy aliens detained by United States military in a foreign land or an overseas visa applicant, to the end of the spectrum, which might involve a United States citizen. While this seems to make perfect sense, this article argues that a closer examination of the century-old jurisprudence suggests that the spectrum is indeed replete with inconsistencies, and as such, is utterly disordered. It further contends that the disorder in the alienage spectrum is a result of the awkward exclusion of the so-called aliens from the benefits of maturing notions of equal protection and due process as a result of the pre-rights era of Chinese exclusion, which is a part of the Plessy v. Ferguson legacy. More specifically, the article contends that the source of the disorder is the century-old tug-of-war between the plenary power doctrine, which immunizes congressional acts relating to immigration from judicial review, on the one hand, and contemporary notions of due process and equal protection on the other. At a more philosophical level, the disorder is a product of a tug-of-war between the perception of the Constitution as a compact between a selected group of "people" with the prerogative to exclude all others, on the one hand, and the perception of the Constitution "as a limitation on the Government's conduct with respect to all whom it seeks to govern" on the other. The interplay between these fundamental assumptions, coupled with historical accidents, has produced a jurisprudence that is incoherent and largely unpredictable. This article purports to define the spectrum, highlight the disorder, identify and characterize the culprit gene, and propose modest reordering steps.


This article offers a critical analysis of recent trends in educational policy with particular reference to their assumptions about the knowledge society. It examines the implications of the analysis for the issue of elitism and the promotion of greater educational equality. The article concludes by offering an alternative approach to educational policy based on a social realist theory of knowledge.


The term fractional-N describes a family of synthesizers that allow the minimum frequency step to be a fraction of the reference frequency. Over the years, a number of methods have been proposed to realize fractional-N frequency synthesis that are based on the basic concepts of traditional integer-N synthesis [refs 1,5]. Among these methods, three techniques are best known in the industry. They are fractional dividerbased, current injection-based, and ∆Σ modulator-based fractional-N. This White Paper describes these methods and provides a general discussion of the use of fractional-N synthesizers in a low-cost, low-power radio.


We performed the numerical simulation for the rigid ellipsoids rotation within the Newtonian viscous matrix. The simulation provided the variation of the shape preferred orientation of the ellipsoids with respect to variables between the degree of non-coaxiality (Θ = 0°–90°) and Flinn parameter (Κ = 0–∞). We used the width and length data collected from 3621 of tourmaline grains as the shape factor of the ellipsoids, and the initial distribution pattern of the ellipsoids is assumed to be random in their orientation. Calculation results are obtained on the plane parallel to the foliation (XY-plane) and the plane vertical to the foliation in parallel with the mineral lineation (XZ-plane), because this facilitates the comparison with nature. Using the calculation result, we compared these results with the natural shape preferred orientation of tourmaline grains embedded within quartz matrix of metacherts. The comparison suggests that natural shape preferred orientation of the tourmaline grains from three metacherts correspond to a pure shear (Θ = 90°) and plane to constrictional strain (Κ = 1–10) with about 1–2 of finite strain.


Numerous references to prayer occur throughout the Old Testament and New Testament. These prayers relate closely to particular circumstances and needs where the petitioner appeals to God, illustrating the importance of prayer as part of the dialogue and communication between God (in the image of a Father) and Israel and the Church (in the image of his children). This article investigates Paul's contribution to this dialogue. In 1 Thessalonians 5:17, Paul exhorts (using the imperative) the Thessalonians to pray 'constantly' (ἀδιαλeίπτως), an exhortation located in the last pericope of the epistle, between two other exhortations (imperatives) indicating time ('always') and space ('all circumstances'). Paul thus uses two more exhortations (surrounding the exhortation, 'pray constantly') to define what he means by 'constant' (without ceasing) prayer. His conviction of this necessity leads him to offer himself as an example of 'praying constantly' when he writes to the community in Thessalonica. Prayers in Paul's epistles focus on the existential needs of daily living, to stand firm against evil and the spiritual need to live pure and blameless lives (complete sanctification) until the parousia . Conclusions arising from Pauline textual references on prayer include: the experience of God is not limited to extraordinary events, but subsists essentially in ordinary daily events; the understanding of God's participation in the lives of believers is not always obvious and comprehensible; the Holy Spirit enables believers spiritually to see, hear and understand God's daily involvement in their lives; and, prayer for the believer facilitates spiritual experiences which provide continuous transformation for the one who 'prays without ceasing'. The result, for Paul, of this form of dialogue and communication between God and his Church, is that regular prayer constitutes joy and thankfulness. Intradisciplinary and/or interdisciplinary implications: This research relates to the disciplines of New Testament and Christian Spirituality. The focus is how to experiencing dialogue with the divine regularly every day. A specific mindset is needed to accomplish this; a mindset to see, hear and experience the divine in everyday life in the ordinary events in life.


Streptococcal species are gram positive bacteria responsible for a variety of infections including pneumonia, meningitis, endocarditis, erysipelas, necrotizing fasciitis, periodontitis, skin and soft tissue infections, chorioamnionitis, funisitis, and neonatal sepsis. In response to streptococcal infections, the host innate immune system deploys a repertoire of antimicrobial and immune modulating molecules. One important molecule that is produced in response to streptococcal infections is lactoferrin. Lactoferrin has antimicrobial properties including the ability to bind iron with high affinity and sequester this important nutrient from an invading pathogen. Additionally, lactoferrin has the capacity to alter the host inflammatory response and contribute to disease outcome. This review presents the most recent published work that studies the interaction between the host innate immune protein lactoferrin and the invading pathogen, Streptococcus.


Current knowledge of tennis player-surface interactions with different court surfaces is limited. The measurement of player step and movement strategy would aid the understanding of tennis player-surface interaction. However, this has not yet been performed: no readily available motion analysis tool is capable of measuring spatio-temporal parameters of gait during match-play tennis. The purpose of this project was to develop, validate and use a motion analysis tool designed to measure player location and foot-surface contacts during match-play tennis.Single camera video footage, obtained from the 2011 Roland Garros Qualifying Tournament, was manually digitised to characterise step and movement strategy during men's and women's forehand groundstrokes. Player movements were consistent with previous notational analyses; however gender differences were highlighted for step frequency. Initial findings were limited by manual analysis, e.g. manual digitising subjectivity and low sample size: an objective and automated system was required.A markerless, view-independent, foot-surface contact identification (FSCi) algorithm was developed. The FSCi algorithm identifies foot-surface contacts in image sequences of gait by quantifying the motion of each foot. The algorithm was validated using standard colour image sequences of walking and running obtained from four unique camera perspectives: output data were compared to three-dimensional motion analysis. The FSCi algorithm identified data for 1243 of 1248 foot-surface contacts; root-mean-square error (RMSE) was 52.2 and 103.4 mm for shod walking and running respectively (all camera perspectives). Findings demonstrated that the FSCi algorithm measured basic, spatio-temporal parameters of walking and running, e.g. step length and step time, without interfering with the activity being observed. Furthermore, analyses were independent of camera view.Video footage obtained from the 2011 ATP World Tour Finals was used to develop a combined player tracking and foot-surface contact identification (PT-FSCi) algorithm. Furthermore, a graphical user interface was developed. The PT-FSCi algorithm was used to analyse twenty match-play tennis rallies: output data were compared to manual digitising. The PT-FSCi algorithm tracked player position and identified data for 832 of 890 foot-surface contacts during match-play tennis. RMSE for player position and foot-surface contacts was 232.9 and 121.9 mm respectively. The calculation of step parameters required manual intervention: this reflected the multi-directional nature of tennis. This represents a limitation to the current algorithm however the segmentation of player movement phases to allow the automatic calculation of step parameters.The analysis of this data indicated that top ranked tennis players can win rallies using movement strategies previously considered to be defensive. Furthermore, step length data indicated that shorter step lengths formed the majority of step strategy. The largest 25% of steps were observed behind the baseline, aligned with deuce and advantage court sidelines. This reflected lunging and turning manoeuvres at lateral extremes of player movement.The single camera system that has resulted from this project will enable the International Tennis Federation to characterise player step and movement strategy during match-play tennis. This will allow a more informed approach to player-surface interaction research. Furthermore, the system has potential to be used for different applications, ranging from sport to surveillance.


During bio-technical processing it is important to monitorbiological parameters such as cell growth, viability andproduct formation. Many of the analyses traditionally used areslow to perform and provide only average data for thepopulation. Flow cytometry is a laser-based technique, whichmeasures physical properties of a cell in a flowing stream, ata rate of several thousand cells per second. It offers theprospect of an at-line, multi-parameter analysis of individualmicroorganisms in a population. In this project several methods for at-line measurements ofbioprocesses were developed such as protocol's for measuringcell concentration, viability and product formation. Theprimary focus was on prokaryotic organisms (E. coli) but eukaryotic organisms (P. pastoris) were included. The possibility to use volumetric cell counting to measurecell concentration (cell number) was evaluated. It was shownthat the method was applicable for high cell density processesof bothE. coliandP. pastoris. The combination of Bis- (1,3-dibutylbarbituric acid)trimethine oxonol (depolarised membranes) and propidium iodide(loss of membrane integrity) as fluorescent markers was usefulto measure viability at-line of cells in high cell densityprocesses. The protocol was shown to be reproducible forE. coliandP. pastoris. The viability staining was used to study the kinetics ofweak organic acids (food preservatives). The protocol provideddata about cell functions such as membrane depolarisation andloss of membrane integrity caused by introducing weak organicacids to shake flask cultures ofE. coli. Labeling inclusion bodies with fluorescent antibodiesprovided a method, which could specifically monitor theincreased accumulation of recombinant promegapoetin proteinwith process time. This technique was further developed forintracellular staining by application of a permeabilising stepbefore labeling with antibodies. Staining of inclusion bodiesdirectly inside permeabilised cells gave information about thedistribution of protein expression in the cell population. In conclusion, flow cytometry provides an at-line, singlecell technique for measurement of several biological parametersin bioprocesses. Key words: flow cytometry, Partec PAS, propidium iodide(PI), bis- (1,3-dibutylbarbituric acid) trimethine oxonol(BOX), Alexa fluor 488, bioprocess,E. coli,P. pastoris, inclusion body, food preservatives,viability, membrane potential


Crashworthiness studies are becoming increasingly important in mechanical design,
particularly with the new advancement of the computer simulation codes. These studies
generally require material and prototype testing for both modelling and validation. Large
percentages of these studies lie on the limits of medium strain rate, which could be
achieved by a drop weight test rig. Therefore, the drop weight test rig becomes an
essential tool for such research activities besides the universal quasi-static testing machines.
This paper is devoted to the analysis and design of the drop weight impact-testing rig.
First, the different aspects of the mechanical design such as the propulsion, guidance,
and frame layout, foundation and energy aspects are presented and discussed. Then, the
basic types of data retrieval and analysis systems applicable for drop weight impact testing
machines are presented and discussed. Data retrieval components considered in this
study include the sensors for load, acceleration, and velocity measurements, image
acquisition including high-speed cameras and PC-based image acquisition system, and
data acquisition including oscilloscope or PC-based data acquisition system which utilizes
an AID card and application software for visualizing and analyzing of the results. At the
end of this article the designed and constructed test machine is presented as a case study.


A 1 trillion node internet of things (IoT) will require sensing platforms that support numerous applications using power harvesting to avoid the cost and scalability challenge of battery replacement in such large numbers. Previous SoCs achieve good integration and even energy harvesting [1][2][3], but they limit supported applications, need higher end-to-end harvesting efficiency, and require duty-cycling for RF communication. This paper demonstrates a highly integrated, flexible SoC platform that supports multiple sensing modalities, extracts information from data flexibly across applications, harvests and delivers power efficiently, and communicates wirelessly.


In this book, the issues regarding the theory of optics and quantum optics of spherical multilayered systems are studied. In such systems the spatial scale of layers becomes comparable with the wavelength of radiation, which complicates the analysis of important quantities such as reflectivity and transmission. Often, a large amount of time is spent on performing numerical calculations and simulation to elucidate the behavior of such electromagnetic properties. The author has written down the calculation details of important properties of multilayered microspheres in a more comprehensive manner, so that undergraduates and practitioners can follow them freely. From a skill-oriented point of view the book covers the following: electrodynamics of multilayered environments in the spherical geometry; methods of calculating both reflection and transmission coefficients from an alternating stack; calculations of elgenfrequencies and quality factors of electromagnetic oscillations; radial distribution of the electromagnetic field in a spherical cavity; computer methods of calculations with C++ as basic languages and construction of the graphic user interface (GUI); the object-oriented approach as a basis of the modern methods of calculation.


Giant cell arteritis is a common form of vasculitis, although involvement of the aorta is unusual. There is no established association between giant cell aortitis and human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection. We present the case of a 46-year-old female coinfected with HIV and HCV who had never received antiretroviral therapy and developed symptoms of deteriorating shortness of breath on exertion. Investigations demonstrated aortic root and ascending aorta dilatation, along with severe aortic valve regurgitation, for which the patient underwent valve-sparing aortic root replacement (a David procedure). Histopathology confirmed giant cell aortitis.


The world's obligate cave-dwelling fauna holds considerable promise for biogeographic analysis because it represents a large number of independent evolutionary experiments in isolation in caves and adaptation to subterranean life. We focus on seven north temperate regions of at least 2000 km2, utilizing more than 4300 records of obligate cave-dwelling terrestrial invertebrates. In North America, highest diversity was found in northeast Alabama while in Europe highest diversity was found in Ariege, France, and in southeast Slovenia. Based on these regions as well as more qualitative data from 16 other regions, we hypothesize that a ridge (ca 42°–46° in Europe and 34° in North America) of high biodiversity occurs in temperate areas of high productivity and cave density. This may reflect a strong dependence of cave communities on long term surface productivity (as reflected in actual evapotranspiration), because the subterranean fauna relies almost entirely on resources produced outside caves. This dependence may explain the unique biodiversity pattern of terrestrial cave invertebrates.


Human agents typically evolve a set of standard routines for carrying out often-repeated tasks. These routines effectively compile knowledge about how to carry out sets of interacting tasks without causing harmful interference. By modifying its routines in response to observed failures, an agent can refine enlarge and refine its planning repertoire over time. We are constructing a software agent, RAFTER, that applies this incremental improvement strategy to the management of planning routines for use in the Truckworld simulator. Currently, we are building in the capacity to make a variety of repairs to the method used in a routine to coordinate constituent tasks; in the future, RAPTER will be extended to include methods for coordinating tasks from different routines.


Habitual (experienced) entrepreneurs are an important sub-group of entrepreneurs who make a fundamental contribution to the process of wealth creation in society. They have been associated with the"entrepreneurial mindset" which induces them to passionately seek and exploit the best opportunities. Despite these exceptional qualities, there are conflicting views among financiers as to whether the additional experience possessed by habitual entrepreneurs is an asset or a liability. Furthermore, there has been limited empirical work that has examined how these experienced entrepreneurs identify and exploit opportunities and whether their practices do indeed differ from those of their novice counterparts. This study seeks to address this void by examining the attitudes and behaviors of 773 novice and habitual entrepreneurs who own firms located throughout Great Britain.


Pegmatites are sources of gem-quality crystals of beryl, tourmaline, topaz, spodumene, and spessartine. Historic localities are found in Brazil, Madagascar, Russia, and the United States, but important deposits have recently been discovered in Africa and Asia. Most high-quality gem minerals occur in miarolitic cavities found near the centers of pegmatite bodies or in reaction zones between pegmatites and ultramafic host rocks. The most important gem-bearing granitic pegmatites formed at shallow levels in the continental crust during the latest stages of collisional plate tectonic events. Single, spectacular miarolitic cavities in some pegmatites have produced tons of gem crystals valued in excess of $50 million.


The paper examines the structural and organisational problems of social insurance systems in Brazil and the Argentine in order to illuminate current debates about pension 'reform'. Much of the present discussion depicts social insurance 'crisis' as a modern phenomenon. Similarly, preoccupations about the macroeconomic objectives of reform - profitable pension funds as an adjunct to capital market deepening, about sustainability - the financial viability of systems, and about equity and coverage, are often assumed to be peculiar to the late twentieth century. The papers stresses the generational (or cyclical) nature of crises that have plagued social insurance regimes in both countries. It also identifies what may be learnt from differences, as well as similarities, between the two systems - not least the relatively larger historic role the private sector and earlier substantive provision for rural workers in Brazil. Following an appraisal of different 'models' (individual 'capitalised' accounts versus pay-as-you-go schemes and monopolistic state systems versus pluralistic/competitive arrangements), the paper concludes with an evaluation of the administrative and financial stability of current schemes.