This paper presents a comprehensive approach to sensitivity and uncertainty analysis of large-scale computer models that is analytic (deterministic) in principle and that is firmly based on the model equations. The theory and application of two systems based upon computer calculus, GRESS and ADGEN, are discussed relative to their role in calculating model derivatives and sensitivities without a prohibitive initial manpower investment. Storage and computational requirements for these two systems are compared for a gradient-enhanced version of the PRESTO-II computer model. A Deterministic Uncertainty Analysis (DUA) method that retains the characteristics of analytically computing result uncertainties based upon parameter probability distributions is then introduced and results from recent studies are shown. 29 refs., 4 figs., 1 tab.


Under the WTO system , the governments successively brought forth new ideas in the traditional civil servant system to adapt to the new living conditions. The civil servant system must be faced with a serious challenges arising in China's entry into WTO. The unlikeness in the national conditions and circumstances determines the differences between Chinese and western countries in the reform and development of the civil servant system concerning the aims, the strategies and the measures . Having the common international circumstance and in particular the background of times to the globlization as well as the similar procedures of the personnel administration , the reform methods of the Western civil servant system afford us beneficial lessons .


The study describes the mathematical calculation of the pumpkin drying process. In order to check the data obtained for different temperatures in the experiment (45, 55 and 65 °C) and to choose the most appropriate model, comparisons were made with different drying models. For this purpose 5 different experimental and theoretical drying models were used, which are widely used in drying processes (Lewis, Henderson and Pabis, two terms, Wang and Singh, Midilli). Statistical calculations were carried out using the Comsol Multiphysics program.


To the Editor: Dous et al provide a comprehensive and coherent critique of the current evidence in the area of sex hormone therapy1; however, because of the paucity of data, a question of huge interest to clinicians and their patients remains necessarily unaddressed: are different estrogen products associated with different risks and benefits? Even if evidence from the classical postmenopausal literature is scarce, there are nevertheless highly informative data emerging from the analysis of European patient registries for male-to-female transsexuals. Whereas the process of gender transition in the United States is entirely patient funded, the United Kingdom and the Netherlands in particular offer different models of care, based on a preponderance of funding direct from the National Health Service and state-backed insurers, respectively. This enables a highly organized model of care in which progress through the transition requires patients to closely adhere to prescribed treatment and monitoring protocols. Unlike postmenopausal women, who are offered a fixed dose of an estrogen T progesterone product without any titration beyond that for suppression of vasomotor symptoms, male-to-female patients in these two countries receive a carefully titrated dose, balanced against clinical outcomes and with monitoring of serum estrogen levels. This is based upon the need to avoid patient overmedication and on clinician awareness of the huge interindividual differences in bioavailability of the same doses of oral and transdermal estradiol valerate (E2). Current guidance indicates that transgender women can continue taking hormone therapy throughout the lifespan. The first clue that not all estrogens are alike arose from analysis of an Amsterdam male-to-female cohort, amongwhom therewas a threefold greater risk of cardiovascular death among current users receiving ethinylestradiol.3,4 An analysis of a London male-to-female cohort found an eightfold greater risk of venous thromboembolism among users of conjugated equine estrogens than among those receiving oral or transdermal E2. Because these studies are unlikely to be replicated among postmenopausal women, clinicians should consider falling in line with the general principle of endocrine therapy, which is to replace the missing hormone (17A-estradiol, or E2, in the context of any hypogonadal female) wherever possible. By analogy, the World Health Organization has long recommended treating male hypogonadism with native testosterone, rather than with anabolic steroids such as nandrolone.6


The leakage and diffusion of pollutants are important issues affecting waters. This paper studies the diffusion of soluble pollutants in water. Based on the three-dimensional hydrodynamic model, a three-dimensional soluble pollutant diffusion model was established and validated. The validation results show that the discrete form of the transport equation used in this model must maintain monotonic properties, and otherwise the model calculation cannot converge. Taking Tianjin Nangang as a representative river section, the cognitive experiment on methanol leakage was carried out to predict the variation characteristics of chemical leakage and diffusion over time in Nangang. The model can be used for chemical leakage and diffusion prediction simulations of other pollutants, and can be used for calculations in runoff and tidal waters.


The compatibility of poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC) blends was investigated with Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. The PLA/PPC blends were prepared over the whole composition range. FTIR spectroscopy revealed that there were several specific interactions between the chains of PLA and PPC: the interaction between CH and OC and CO···OC or CO···OC dipole–dipole interactions. Moreover, PLA and PPC were compatible. DSC indicated that PLA and PPC were partially miscible but compatible to some extent because of the similar chemical natures of the blend components. TGA showed that the compatibility of PLA and PPC enhanced the thermal stability of PPC in the blends. As calculated by the Horowitz–Metzger equation, the activation energy for decomposition (Et) of PPC in PLA/PPC (70/30) was 200.6 kJ/mol, whereas Et of pure PPC was only 56.0 kJ/mol. A study of the mechanical properties versus the composition and the strain versus the stress illustrated that there was good compatibility between PLA and PPC, and the phase inversion of the PLA/PPC system occurred between 70 and 60 wt % PLA in the PLA/PPC blends. The Pukanszky model gave credit to very strong interfacial adhesion between PLA and PPC. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 94–101, 2006


Work on the role of attribution in close relationships is reviewed and evaluated. Evidence indicates that attributional activity is pervasive in close relationships, but particularly intensive at times of major problems or conflicts. People in close relationships appear to use attributions not only to search for causal understandings and to assign responsibility and blame, but also to communicate affect and to try to influence one another. Recent work on distressed couples and the role of attribution in such distress also is discussed. Finally, directions for future research on attribution in close relationships are suggested. These include use of multiple measures of thought and behavior over extended periods of time, increased attention to archival sources, and an emphasis upon content as well as process in relationship activity and on attributions that are interactive and complex in focus and meaning.