Print version ISSN 1020-4989
Rev Panam Salud Publica vol.16 n.6 Washington Dec. 2004
ORIGINAL RESEARCH INVESTIGACIÓN ORIGINAL
La epidemiología de la diarrea por rotavirus en América Latina. Perspectivas de vacunación frente al rotavirus
Erin M. KaneI; Reina M. TurciosI; Melissa L. ArvayI; Salvador GarciaII; Joseph S. BreseeI; Roger I. GlassI
IViral Gastroenteritis Section, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
IIThe Pan American Health Organization, Washington, D.C., USA
OBJECTIVE: To assess the disease burden and characterize the epidemiology of rotavirus diarrhea in Latin America.
METHODS: We conducted a literature review of studies of children < 5 years of age who were hospitalized or seen as outpatients for diarrhea and for whom rotavirus was sought as the etiologic agent of the diarrhea. This review included inpatient and outpatient studies published since 1998 that included at least 100 children and reported surveillance activities lasting at least 12 consecutive months.
RESULTS: A total of 18 inpatient and 10 outpatient studies met the criteria for inclusion in this review. Rotavirus was detected in a median of 31% of inpatients (range, 16%52%) and 30.5% of outpatients (range, 4%42%). The median detection rate was higher in studies that used an enzyme-linked immunosorbent assay (ELISA) (inpatients 38%, outpatients 33%) versus less sensitive methods of detection. The age distribution of rotavirus disease varied among countries, with 65%85% of children hospitalized in the first year of life. Most countries had rotavirus admissions year round, and rotavirus generally exhibited a winter seasonal peak in both temperate and tropical climates.
CONCLUSIONS: The heavy burden of disease attributable to rotavirus in Latin America suggests that vaccines currently being tested could have considerable impact in preventing hospitalizations, clinic visits, and deaths. The findings of the young age distribution of patients highlight the importance of early immunization for the success of a vaccine program. The data suggest that future surveillance for rotavirus diarrhea in Latin America should use a standardized surveillance protocol with an ELISA for detection. Data from surveillance studies will be critical to monitor the impact of the future introduction of vaccines.
Key words: Rotavirus; disease outbreaks; burden of illness; epidemiology; Latin America.
OBJETIVO: Valorar la carga de enfermedad e identificar las características epidemiológicas de la diarrea causada por rotavirus en América Latina.
MÉTODOS: Realizamos una revisión de la literatura que abarcaba los estudios de niños menores de 5 años que fueron hospitalizados o atendidos como pacientes ambulatorios a causa de la diarrea, y en los cuales se buscó al rotavirus como agente etiológico de la diarrea. Nuestro trabajo de revisión incluye los estudios publicados desde el año 1998 sobre pacientes ingresados y ambulatorios, que incluyeron a 100 niños o más, y que informaron sobre actividades de vigilancia que se prolongaron durante al menos 12 meses consecutivos.
RESULTADOS: Un total de 18 estudios de pacientes ingresados y 10 estudios de pacientes ambulatorios satisficieron los criterios de inclusión de nuestro trabajo de revisión. Se detectó el rotavirus en el 31% (mediano) de los pacientes ingresados (intervalo del 16% al 52%) y en el 30.5% de los pacientes ambulatorios (intervalo del 4% al 42%). La tasa mediana de detección fue mayor en los estudios que emplearon un ensayo de encimoinmunoanálisis (ELISA) (pacientes ingresados: 38%, pacientes ambulatorios: 33%) frente a otros métodos de detección menos sensibles. La distribución de la enfermedad rotavírica según la edad difería entre países, aunque la proporción de niños hospitalizados durante el primer año de vida fue del 65% al 85%. En la mayoría de los países se produjeron ingresos hospitalarios por rotavirus durante todo el año, y el rotavirus normalmente mostraba un máximo estacional en el invierno tanto en las zonas de clima tropical como en aquellas de clima templado.
CONCLUSIONES: La importante carga de enfermedad que se atribuye al rotavirus en América Latina sugiere que las vacunas que están siendo ensayadas en la actualidad podrían tener un impacto considerable en la prevención de las hospitalizaciones, consultas a los centros de salud, y muertes. La distribución de la enfermedad entre los pacientes más jóvenes subraya la importancia de la inmunización precoz en el éxito de los programas de vacunación. Los datos sugieren que en el futuro, los programas de vigilancia para detectar la diarrea causada por rotavirus en América Latina deberían usar un protocolo normalizado de vigilancia con ELISA para la detección del virus. Los datos provenientes de estudios de vigilancia serán de importancia fundamental para el seguimiento del impacto de la introducción de vacunas en el futuro.
Severe gastroenteritis caused by rotavirus is a leading cause of childhood illness and death, particularly in developing countries. Each year, rotavirus infections claim the lives of approximately half a million children worldwide and lead to an estimated 2 million hospitalizations, 25 million clinic visits, and 111 million episodes of diarrhea in children < 5 years of age (1). Because the disease cannot be eliminated through improvements in water and sanitation, vaccines have been developed as the prime method of control (24). Two vaccines nearing licensure aim to prevent severe disease leading to dehydration, hospitalization, and death. The accelerated development and introduction of a rotavirus vaccine has been designated a global priority by the World Health Organization, the Global Alliance for Vaccines and Immunization, and many international groups because the burden of disease is large, vaccines are close at hand, and the impact of their introduction should be almost immediate (5).
Latin America is likely to be the first region in the developing world to be targeted for the introduction of a rotavirus vaccine. Both vaccines nearing licensure are being tested in the region, and for new vaccines, like those for Hepatitis B and Haemophilus influenzae b, Latin America has been the first site in the developing world to embrace their introduction. Yet despite the impending availability of rotavirus vaccines, knowledge of the epidemiology and disease burden of rotavirus in the Region remains limited, and many policymakers are unaware of the high prevalence of this disease. This is not surprising, since despite the broad recognition of the importance of childhood diarrhea, physicians rarely seek rotavirus as the etiologic agent because knowledge of the pathogen does not alter treatment with rehydration therapy. Efforts to establish rotavirus surveillance in the Americas are ongoing, but to date, only limited data are uniformly available from a range of countries in the Region spanning a full year or more.
In anticipation of the need for better estimates of the disease burden of rotavirus and more comprehensive epidemiologic information, as well as background data to establish a rotavirus surveillance network in the Region, we reviewed recent studies of rotavirus disease among children in Latin America published between 1998 and 2003. The objectives of this review were to examine the disease burden, the rate of detection of rotavirus among children with diarrhea who were hospitalized or visited outpatient clinics, and the age distribution and seasonality of rotavirus infection.
For this review, we identified papers from a multilingual MEDLINE search of publications, using the keyword "rotavirus" and the name of 43 Latin American countries, and from citations noted in studies found through the MEDLINE search. From these studies, we extracted information on the detection rate of rotavirus and methods used, the location, duration, and size of the study, and the age of the children enrolled. The studies were grouped by setting-inpatient or outpatient-and analyzed separately, since rotavirus detection rates vary significantly by severity of illness, with the highest detection rates reported among hospitalized children with more severe disease. For inpatient and outpatient settings, we limited the review to those studies published since 1998 that included at least 100 children < 5 years of age and that reported surveillance activities lasting at least 12 consecutive months. All methods of rotavirus detection were considered, including enzyme-linked immunosorbent assay (ELISA), polyacrylamide gel electrophoresis (PAGE), and latex agglutination (LA).
For those studies that provided detailed information on the ages of patients < 3 years of age, we plotted and compared the distribution of rotavirus cases by age groups: 0 to 5, 6 to 11, 12 to 23, and 24 to 35 months. Seasonal and geographical trends in rotavirus diarrhea were reviewed from studies presenting detailed information about monthly detection for at least one calendar year. To determine the peak season, we plotted the rotavirus detection rates by month and defined peaks as a period of 3 months or more in which the rate of detection was consistently above the yearly median for the 12-month period.
Overview of inpatient and outpatient studies
We identified 18 studies of children hospitalized for gastroenteritis that met the criteria for inclusion in this review (Table 1). Overall, rotavirus was detected in a median of 31% of children, and the detection rates ranged 3-fold between studies, from 16% to 52%. To understand this variability, we compared rates of detection, stratifying by assay method, age of patients enrolled, and size and duration of the study. The assay method clearly affected the detection rates, and the 12 studies that used ELISA reported higher rates of rotavirus (median 38%, range 16%52%) than the five that did not (median 24%, range 16%32%). This difference was not statistically significant for the inpatient studies alone but was significant when combined with data from the 10 outpatient studies. We then examined whether rates of hospitalization were associ-ated with the size or the duration of the study or with the patients' ages. The rates of detection by ELISA were slightly lower for longer studies when compared with shorter ones, but the size of the study did not affect detection rates. Surprisingly, the age cutoff did not affect detection rates; the nine studies that enrolled children <5 years of age had rates of rotavirus detection similar to those of studies limited to children <3 years old.
We examined the characteristics of six studies reporting rates at the extremes of the range-four with detection rates < 20% and two with rates > 50%. Rotavirus usually spares children in their first few months of life, and three of the four studies with low detection rates included an unusually large number of young infants. The Brazil study was conducted at a center that focused on neonatal care, and 47% (48/102) of samples were from infants < 6 months of age (6). The Venezuela study enrolled children < 5 years old, but nearly two-thirds were < 1 year of age (7). The study from Uruguay included children > 20 months old, with a mean age of 45 months (8). In addition, this study investigated diagnoses of both "persistent" and "acute" diarrhea, whereas rotavirus is associated with acute diarrhea alone. Two of the low-reporting studies (7, 9) used the less sensitive PAGE system for detection. We could not identify a plausible explanation for the high rates of > 50% reported by two studies (10, 11).
Ten studies of children with gastroenteritis who were treated as outpatients met the criteria for inclusion in this review (Table 2). The rates of detection for these studies ranged 10-fold from 4% to 42%, with a median of 30.5%. Again, detection rates in the two studies that used PAGE for detection were lower (median 12%, range 4% 20%) compared with rates for the eight that used ELISA (median 33%, range 18%42%). The number of children included in the study ranged from 106 to 2 929, with a median of 724, and the detection rate was not associated with study size. Likewise, neither the age cutoff nor the duration of study correlated with detection rates. The most notable outlier, the Brazilian study with a rotavirus detection rate of 4%, used the less-sensitive PAGE method and enrolled two patient populations: private patients who had a detection rate of less than 3% and public health patients whose detection rate was 29%. The study with the highest outpatient detection rate of 42% occurred in a prepaid clinic that served patients of a different socioeconomic background than the general population (12).
Age of patients with rotavirus diarrhea
To investigate the age distribution of children with rotavirus diarrhea, we identified five studies that provided detailed age data on the patients studied (Figure 1). The cumulative frequency distribution of children with rotavirus was plotted by age, and we identified substantial variability. The curves for Venezuela and Colombia were steeper and to the left of those for Argentina, Paraguay, and Brazil, indicating that patients were younger. By 611 months of age, nearly 80% of children in Colombia and Venezuela, versus 40% 50% of children in Argentina, Brazil, and Paraguay, had sought care for rotavirus diarrhea. Furthermore, if a vaccine were available but not administered until 5 months of age, 40% of all rotavirus cases in Venezuela and 25% of all cases in Colombia would not be prevented. A finding of note was that the two countries with the youngest age distribution were both in the tropics rather than in the temperate zone.
Seasonality of rotavirus infection
We examined the seasonal patterns of disease by plotting the monthly detection of rotavirus in the studies that provided detailed data on rotavirus hospitalization by month (Figure 2). The 10 studies that were identified spanned latitudes from 10° north to 35° south. In most countries, rotavirus was detected throughout the year. The only locations where rotavirus was not detected for 2 consecutive months were Juiz de Fora and Porto Alegre in Brazil. We examined the hypothesis that the seasonality of rotaviruses was distinct in countries located in temperate versus tropical climatic zones. The five studies from cities in the tropics (between 23.5° north and south of the equator) all had winter peaks not unlike the five studies from cities in the temperate zone. As expected, the winter peaks in the northern hemisphere occurred roughly between November and February, while the peaks in the southern hemisphere occurred between May and August.
In Latin America, rotavirus remains the major cause of hospitalization and outpatient visits for children with diarrhea. This review of 28 studies of children hospitalized for severe diarrhea in eight Latin American countries identified rotavirus as the cause of disease in 31% of patients in the studies that used any assay and in 38% of patients in the studies that used the more sensitive ELISA. In general, rotavirus is detected less frequently in children with milder disease, so we were surprised to find that the rate of detection among children with diarrhea seen as outpatients (30.5%) did not differ greatly from that among children who were hospitalized with more severe disease. Most children were hospitalized during their first year of life, and 90% of all rotavirus hospitalizations were among children < 2 years of age. Although rotavirus infections had a distinct seasonal peak in most countries, most countries also had rotavirus admissions year round.
Several features of rotavirus epidemiology and surveillance were identified in this review that have implications for future surveillance and further study. First, studies that used ELISA for detection had rates of rotavirus that were higher than studies that used less sensitive methods, an observation on diagnostic sensitivity noted previously (1315) and evident from our results. Second, we found two different age distributions: in two tropical countries, nearly 90% of the children were hospitalized in the first year of life, whereas in the three countries with temperate climates, rotavirus occurred significantly later. We could not gather enough information from the remaining studies to determine whether this relationship to latitude was significant and thus would need to confirm this in prospective surveillance studies now being planned. Nonetheless, the early age of illnesswith 20%60% of rotavirus cases occurring by 6 months of age-indicates that vaccination early in life will be important to realize the greatest benefit from the vaccine.
The detection rates of hospitalization for rotavirus in our study (31% 38%) were intermediate between a multicountry surveillance study recently conducted in Asia (45%) and a similar literature review from Africa (24%) (16, 17). This difference in rates may reflect the prevalence of competing pathogens that are also responsible for hospitalization for severe diarrhea, with the highest incidence of other organisms appearing in children in Africa. Within Latin America, a recent multicenter study in three countries found rates of hospitalization for rotavirus that ranged 2-fold from 38% in Venezuela to 70% in Argentina (18). Of note was that the rate of rotavirus detection was inversely proportional to the size of the study populations, with < 100 patients enrolled in Argentina but > 1 000 in Venezuela. The rate for Venezuela, the site providing most of the data, was very close to our estimate for Latin America. Finally, a recent series of industry-supported studies of the prevalence of hospitalizations for rotavirus in 11 countries in Latin America, which were done in anticipation of the vaccine trials conducted by GlaxoSmithKline, identified rates of rotavirus detection of 49%, with substantial variability between countries and months of observation (19). Rates in these studies are difficult to compare because none of these studies spanned a full year and many included the season in which rotavirus infection would be expected to reach its peak.
A main limitation of this study is that we focused on large, recently published studies that were conducted in large, richer countries; studies from the poorer and smaller countries in the Region, where the pattern of disease may be different, are underrepresented. For some countries such as Mexico, many excellent studies were conducted before the starting date for the current review. Therefore, our observations, while interesting, do not provide an exhaustive picture of the epidemiology in all 43 countries of the Region but only glimpses of the disease burden in eight of the larger countries.
This review provides some important guidelines for establishing further surveillance of rotavirus in Latin America. First, it is clear that future studies should rely exclusively on the more sensitive ELISA rather than other competing detection methods. Furthermore, surveillance needs to be conducted for time periods of years to avoid biases from recruiting only in a high or low season. More data from poor or small countries could make the results more representative and help identify whether real differences exist by size or by per capita income. A question this study leaves unanswered is whether more children experience rotavirus in their first year of life in tropical climates compared to temperate climatesa characteristic that might influence the value of earlier vaccination. Use of a uniform generic protocol for sentinel hospital surveillance with standard detection methods would not only aid further assessments of the current rotavirus disease burden, but would also provide a robust means for monitoring the impact of vaccines when they are introduced (19). Communication of these results on a monthly basis might further enhance awareness of this common and important childhood disease, which may soon be preventable by vaccination.
Acknowledgements. E. Kane is a student at Harvard University and was funded with a summer grant from the CDC Foundation. We thank Delfina Urbina, Norma Santos, Lynn Eibensteiner, Erik Hummel-man, Umesh Parashar, and Nkiruka Ohameje for providing additional data for the preparation of this article, Claudia Chelsey for editorial assistance, and Jon Andrus (PAHO) and John Wecker (PATH) for continued support.
1. Parashar UD, Hummelman EG, Bresee JS, Miller MA, Glass RI. Global illness and deaths caused by rotavirus disease in children. Emerging Infect Dis. 2003;9(5):56572. [ Links ]
2. Bresee JS, Glass RI, Ivanoff B, Gentsch JR. Current status and future priorities for rotavirus vaccine development, evaluation and implementation in developing countries. Vaccine. 1999;17(18):220722. [ Links ]
3. Clark HF, Offit P, Glass R. Rotavirus vac-cines. In: Plotkin SA, Orenstein WA, eds. Vaccines. Philadelphia: Saunders-Elsevier; 2004. Pp. 132745. [ Links ]
4. Linhares AC, Bresee JS. Rotavirus vaccines and vaccination in Latin America. Panam J Public Health. 2000;8(5):30531. [ Links ]
5. Glass R, Bresee J, Parashar U, Jiang B, Gentsch J. Viewpoint. The future of rotavirus vaccines: a major setback leads to new opportunities. Lancet. 2004;363:154750. [ Links ]
6. Da Silva Domingues AL, da Silva Vaz MG, Moreno M, Camara FP. Molecular epidemiology of group A rotavirus causing acute diarrhea in infants and young children hospitalized in Rio de Janeiro, Brazil, 19951996. Braz J Infect Dis. 2000;4(3):11925. [ Links ]
7. Callejas D, Estevez J, Porto-Espinoza L, Monsalve F, Costa-Leon L, Blitz L, et al. Influencia de los facotres climatológicos en la epidemiología de la infección por rotavirus en los niños menores de 5 años de la ciudad de Maracaibo, Venezuela [Effect of climatic factors on the epidemiology of rotavirus infection in children under 5 years of age in the city of Maracaibo, Venezuela]. Invest Clin. 1999; 40(2):8194. [ Links ]
8. Torres ME, Pirez MC, Schelotto F, Varela G, Parodi V, Allende F, et al. Etiology of children's diarrhea in Montevideo, Uruguay: associated pathogens and unusual isolates. J Clin Microbiol. 2001;39(6):21349. [ Links ]
9. Candia N, Parra GI, Chirico M, Velazquez G, Farina N, Laspina F, et al. Acute diarrhea in Paraguayan children population: detection of rotavirus electropherotypes. Acta Virol. 2003; 47(3):13740. [ Links ]
10. Cama RI, Parashar UD, Taylor DN, Hickey T, Figueroa D, Ortega YR, et al. Enteropathogens and other factors associated with severe disease in children with acute watery diarrhea in Lima, Peru. J Infect Dis. 1999; 179(5):113944. [ Links ]
11. Maldonado AJ, Bastardo JW. Prevalencia de subgrupos, serotipos y electroferotipos de rotavirus humanos en Cumaná, Venzuela [Prevalence of subgroups, serotypes and electropherotypes of human rotavirus in Cumana, Venezuela]. Invest Clin. 1998;39(1): 3951. [ Links ]
12. Ramirez Y, Pastorini J, Russi JC, Ferrari AM. Enfermedad diarreica aguda. Características de la población asistida en el CASMU. Abril 1997abril 1998. Arch Pediatr Urug. 2001;72 (2):1105. [ Links ]
13. Fischer TK, Gentsch JR. Rotavirus typing methods and algorithms. Rev Med Virol. 2004; 14:7182. [ Links ]
14. Steele AD, Williams MM, Bos P, Peenze I. Comparison of two rapid enzyme immunoassays with standard enzyme immunoassay and latex agglutination for the detection of human rotavirus in stools. J Diarrhoeal Dis Res. 1994;12(2):11720. [ Links ]
15. Arens M, Swierkosz EM. Detection of rotavirus by hybridization with a nonradioactive synthetic DNA probe and comparison with commercial enzyme immunoassays and silver-stained polyacrylamide gels. J Clin Microbiol. 1989;27(6):12779. [ Links ]
16. Cunliffe NA, Kilgore PE, Bresee JS, Steele AD, Luo N, Hart CA, et al. Epidemiology of rotavirus diarrhoea in Africa: a review to assess the need for rotavirus immunization. Bull World Health Organ. 1998;76(5):52537. [ Links ]
17. Bresee J, Fang Z-Y, Wang B, Nelson E, Tam J, Soenarto Y, et al. First Report from the Asian Rotavirus Surveillance Network. Emerging Infect Dis. 2004;10(6):98895. [ Links ]
18. O'Ryan M, Perez-Schael I, Mamani N, Pena A, Salinas B, Gonzalez G, et al. Rotavirus- associated medical visits and hospitalizations in South America: a prospective study at three large sentinel hospitals. Pediatr Infect Dis J. 2001;20(7):68593. [ Links ]
19. World Health Organization. Generic protocols (i) hospital-based surveillance to estimate the burden of rotavirus gastroenteritis in children and (ii) a community based survey on utilization of health care services for gastroenteritis in children. Geneva: World Health Organization; 2002: Pp. 167. [ Links ]
20. Bok K, Castagnaro N, Borsa A, Nates S, Espul C, Fay O, et al. Surveillance for rotavirus in Argentina. J Med Virol. 2001;65(1):1908. [ Links ]
21. Giordano MO, Ferreyra LJ, Isa MB, Martinez LC, Yudowsky SI, Nates SV. The epidemiology of acute viral gastroenteritis in hospitalized children in Cordoba City, Argentina: an insight of disease burden. Rev Inst Med TropSão Paulo. 2001;43(4):1937. [ Links ]
22. Cardoso DD, Soares CM, Dias e Souza MB, de Azevedo Mda S, Martins RM, Queiroz DA, et al. Epidemiological features of rotavirus infection in Goiania, Goias, Brazil, from 1986 to 2000. Mem Inst Oswaldo Cruz. 2003;98(1): 259. [ Links ]
23. Gusmão RH, Mascarenhas JD, Gabbay YB, Lins-Lainson Z, Ramos FL, Monteiro TA, et al. Rotavirus subgroups, G serotypes, and electropherotypes in cases of nosocomial infantile diarrhoea in Belem, Brazil. J Trop Pediatr. 1999;45(2):816. [ Links ]
24. Da Rosa e Silva ML, Pires de Carvalho I, Gouvea V. 19981999 rotavirus seasons in Juiz de Fora, Minas Gerais, Brazil: detection of an unusual G3P epidemic strain. J Clin Microbiol. 2002;40(8):283742. [ Links ]
25. Correa A, Solarte Y, Barrera J, Mogollon D, Gutierrez MF. Caracterización molecular de rotavirus en la ciudad de Santafé de Bogotá, Colombia. Determación de electroferotipos y tipificación de una cepa por RT-PCR [Molecular characterization of rotavirus in the city of Santa Fe de Bogota, Colombia. Determination of the electropherotypes and typing of a strain by RT-PCR]. Rev Latinoam Microbiol. 1999;41 (3):16773. [ Links ]
26. Coluchi N, Munford V, Manzur J, Vazquez C, Escobar M, Weber E, et al. Detection, subgroup specificity, and genotype diversity of rotavirus strains in children with acute diarrhea in Paraguay. J Clin Microbiol. 2002;40(5): 170914. [ Links ]
27. Perez-Schael I, Gonzalez R, Fernandez R, Alfonzo E, Inaty D, Boher Y, et al. Epidemiological features of rotavirus infection in Caracas, Venezuela: implications for rotavirus immunization programs. J Med Virol. 1999;59(4):520-6. [ Links ]
28. Vizcaya Delgado LE, Flores Carrero A, Hernandez JG, Nieves Blanco B, Perez-Schael I. Origen bacteriano de la enfermedad diarreica aguda en Mérida, Venezuela [Bacterial origin of acute diarrhea in Merida, Venezuela]. Rev Cuba Med Trop. 1999;51(1):149. [ Links ]
29. Urrestarazu MI, Liprandi F, Perez de Suarez E, Gonzalez R, Perez-Schael I. Características etiológicas, clínicas y sociodemográficas de la diarrea aguda en Venezuela [Etiologic, clinical and socio-demographic characteristics of acute diarrhea in Venezuela]. Rev Panam Salud Publica. 1999;6(3):14956. [ Links ]
30. Gonzalez FS, Sordo ME, Rowensztein G, Sabbag L, Roussos A, De Petre E, et al. Diarrea por rotavirus. Impacto en un hospital de niños de Buenos Aires [Rotavirus diarrhea. Impact in a pediatric hospital of Buenos Aires]. Medicina. 1999;59(4):3216. [ Links ]
31. Bittencourt JA, Arbo E, Malysz AS, Oravec R, Dias C. Seasonal and age distribution of rotavirus infection in Porto Alegre-Brazil. Braz J Infect Dis. 2000;4(6):27983. [ Links ]
32. Santos N, Volotao EM, Soares CC, Albuquerque MC, da Silva FM, de Carvalho TR, et al. Rotavirus strains bearing genotype G9 or P recovered from Brazilian children with diarrhea from 1997 to 1999. J Clin Microbiol. 2001;39(3):115760. [ Links ]
33. Berois M, Libersou S, Russi J, Arbiza J, Cohen J. Genetic variation in the VP7 gene of human rotavirus isolated in Montevideo-Uruguay from 19961999. J Med Virol. 2003;71(3):45662. [ Links ]
34. Urbina D, Arzuza O, Young G, Parra E, Castro R, Puello M. Rotavirus type A and other enteric pathogens in stool samples from children with acute diarrhea on the Colombian northern coast. Int Microbiol. 2003;6(1):2732. [ Links ]
Send correspondence and reprint requests to Reina Turcios, Viral Gastroenteritis Section, MS A34, 1600 Clifton Road, NE, Atlanta, GA 30333, United States of America; telephone: (404) 639 3048; fax (404) 639 3645; e-mail: RTurcios@cdc.gov
Manuscript received on 2 September 2004. Accepted for publication on 13 September 2004.
Suggested citation: Kane EM, Turcios RM, Arvay ML, Garcia S, Bresee JS, Glass RI. The epidemiology of rotavirus diarrhea in Latin America. Anticipating rotavirus vaccines. Rev Panam Salud Publica. 2004;16(6):3717.


By anyone’s measure, Johannes Kepler ranks as a gold medalist in the history of science. This great German mathematician and astronomer (contemporary with the King James Bible and the Pilgrims) discovered fundamental laws of nature that have stood the test of time and are still widely used today. He advanced mathematics in science to new heights, including the first use of logarithms for astronomy and the foundation for integral calculus. He made useful inventions. He was a major force in moving science away from its subservience to authority and onto an empirical foundation, and from superstition to mathematical law. He helped mankind understand how the universe works. When the great Isaac Newton expressed that his ability to see farther than others was due to “standing on the shoulders of giants,” he most certainly had Kepler in mind. Yet this humble, devout Christian, from a poor, uneducated home, had a life filled with difficulty. In spite of it, he stands as a consummate example of a Christian doing excellent science from theological motives; Kepler pursued science as a mission from God. In his words, he was merely “thinking God’s thoughts after Him.” Anyone who thinks Christianity is inimical to science should take a close look at the life of this giant of science – and Christian faith.
Kepler is considered the Father of Celestial Mechanics. The story of how he worked for eight years trying to figure out the orbit of Mars and the other planets from the observations of Tycho Brahe is legendary. Kepler was a perfectionist; “close enough” was not good enough. He started by assuming the common belief that the orbits of the planets must be perfect circles. Moreover, he had a tempting hypothesis of his own, that the ratios of the orbital distances must match the proportions of the regular solids. But it did not quite work. It was Kepler’s genius and integrity that forced him to abandon his pet theory and discover the truth.
After many years of work, and thousands of pages of tedious calculations, he fit the data to the formula for an ellipse, and finally, everything fell into place. This illustrates how in science frequently a fundamental truth lays lurking in the minute details that do not fit the expectations. To an honest scientist, the data must drive the conclusions, and Kepler’s discovery ranks as a seminal point in the history of science. With this finding, he overcame 1500 years of error based on the thinking of Ptolemy, Aristotle and even Copernicus that the heavenly orbits must be perfect circles.
From his discovery, Kepler derived his famous Three Laws of Planetary Motion. These were the first truly scientific laws, based as they were on empirical data and not authority or Aristotelian logic. They were also solidly based in mathematics, and could be used to make predictions. Kepler established precise mathematical relationships describing orbital motion:
- The orbits of the planets are ellipses, with the sun at one focus.
- The motion of a body is not constant, but speeds up closer to the sun (a line connecting the sun and the planet sweeps out equal areas in equal times).
- The farther away a planet is, the slower it moves (the square of the period is proportional to the cube of the semimajor axis).
Newton later explained these relationships in his theory of universal gravitation, but Kepler’s Laws are just as accurate today as when he first formulated them, and even more useful than he could have imagined! Even today, NASA’s Jet Propulsion Laboratory navigates spacecraft around the solar system using Kepler’s Laws, and astronomers routinely speak of Keplerian orbits not only for the solar system but for stars orbiting galaxies, and for galaxies orbiting clusters and superclusters. The whole universe obeys Kepler’s Laws, or as he would have preferred to say, obeys God’s laws that he merely uncovered: he said:
Since we astronomers are priests of the highest God in regard to the book of nature, it befits us to be thoughtful, not of the glory of our minds, but rather, above all else, of the glory of God.
These discoveries alone would be enough to guarantee Kepler membership in the science hall of fame, but there’s much more. Not only was he the Father of Celestial Mechanics, Kepler is also considered the Father of Modern Optics. He advanced the understanding of reflection and refraction and human vision, and produced improvements in eyeglasses for both nearsightedness and farsightedness, and for the telescopes that his colleague Galileo (with whom he corresponded) had first turned toward the heavens. He invented the pinhole camera and designed a gear-driven calculating machine. He investigated weather phenomena and also made other fundamental discoveries about the heavens, such as the rotation of the sun, and the fact that ocean tides are caused primarily by the moon (for which Galileo derided him, but Kepler was proved right). He predicted that trigonometric parallax might be used to measure the distances to the stars. Though the telescopes of his day were too crude to detect the parallax shift, he was right again, and the Hipparcos satellite (1989-1993) used this principle to refine our measurements to thousands of stars. Kepler’s “firsts” make an impressive list of accomplishments.
One would think a man must be the son of a privileged family to rise to such heights, but nothing could be farther from the truth for this scientist, as for other great Christians in this series like Newton, Carver and Faraday. Kepler came from a poor, uneducated family. He was often ill, and lived with no advantages that would have predicted his success. His mother was a flighty woman given to superstition, and his father was a roaming mercenary, frequently off to the battlefield to fight for the highest bidder. At age six, Kepler saw the Great Comet of 1577. In those days, people assumed comets were bad omens, but Kepler was fascinated.
Later, his father bought and operated a low-class inn, and young Johannes was required to do hard labor to help the struggling family business. When given a chance to go to school, Kepler’s genius coupled with diligence advanced him quickly. Devout by nature, he decided he would serve God as a clergyman. He studied for two years in a seminary at the University of Tubingen, receiving training in Latin, Greek, Hebrew, mathematics and the usual Greek philosophy, but there also became acquainted with the newer ideas of Copernicus and those who doubted that the Greeks were the last word in knowledge. It was only when he was pressured to accept a position as a mathematics instructor 500 miles away in Graz that he reluctantly postponed his goal to become a Lutheran minister. Later, he was chosen by the great but eccentric Danish astronomer Tycho Brahe to figure out the problem of the orbit of Mars, and the rest is history.
In spite of his successes, Kepler’s life was filled with hardship, poverty, political turmoil, false accusations and difficult work. He had to defend his mother who was falsely accused of being a witch. He was forced to move on several occasions due to religious wars or pestilence. He was never paid near what he was worth. He probably never thought of himself as famous. Yet he had an inner joy that would make his imagination soar when he thought of the heavens and how everything worked according to the Creator’s mathematical plan.
A man of passionate imagination as well as scientific rigor, Kepler imagined space travel and speculated about earthlike planets around distant stars. He wrote 80 books, including the first science fiction story, The Dream (about an imaginary flight to the moon), and of course more technical treatises such as the consummate compilation of Tycho’s data using logarithms, The Rudolphine Tables; this work did much to advance the heliocentric theory. His signature work, expressing his philosophy of science, is Harmony of the World in which he saw the heavenly bodies making a kind of celestial “music of the spheres” as the outworking of the mind of God, perfect in geometric harmony. It expressed his belief that the world of nature, the world of man and world of God all fit together into a harmonious system that could be explored by science.
Johannes Kepler had once believed that becoming a clergyman was the only way to serve God and proclaim His truth, but he found that astronomy and mathematics were also a ministry, a way to open windows to the mind of God. Deeply spiritual all his life, he said, “Let also my name perish if only the name of God the Father is elevated.” On November 15, 1630, as he lay dying, he was asked on what did he pin his hope of salvation. Confidently and resolutely, he testified: “Only and alone on the services of Jesus Christ. In Him is all refuge, all solace and welfare.”
Craters on the moon and Mars are named in Kepler’s honor. NASA’s Kepler spacecraft was launched in March, 2009 and completed its mission in 2018, having found over 3,000 extrasolar planets, all of them obeying Kepler’s Laws of Motion.


Nature's services is an umbrella term for the ways in which nature benefits humans, particularly those benefits that can be measured in economic terms. Robert Costanza and other theorists of natural capital conducted extensive economic analysis of nature's services to humanity in the 1990s. The economic contribution of seventeen of these was found to be approximately US$33 trillion per year, greater than the activities in the inter-human economy, which totaled about US$25 trillion. This was based on estimated costs of replacing the services nature provides, with equivalent services using methods wholly based on human infrastructure.
This study has been widely cited in natural capital, value of Earth and value of life debates. It is a cornerstone of human development theory and Natural Capitalism. It has also had broad influence on theories of service economy, which redefine commodity markets and brand name product sales strictly as services: for example, governments providing means of protection of the natural capital which automatically provides such services as:
Worldwatch Institute, World Resources Institute, Rocky Mountain Institute, Greenpeace, and various United Nations agencies, along with a few governments (including the United Kingdom and Canada) are actively expanding the analysis, with an eye to producing UN standards for valuating natural capital. This is anticipated to have a major effect on money supply debates, as the creation of money by banks for purposes of funding ecosystem depletion has become a major global governance issue, of importance equivalent to land reform, developing nation debt and terrorism. In combination, these are thought by some theorists, including Thomas Homer-Dixon, to be closely related to ecological depletion and heightened competition for scarce natural resources. If the nature's services analysis is valid, then humans also compete to protect the natural capital which in turn provides them services they cannot pay for in a cash economy. Funding its depletion thus creates a vicious cycle.
However, this debate appears to have had little influence on government policy or on WTO, IMF or G8 economic and trade policy. The anti-globalization movement, ecology movement, peace movement, and conservation movement, and their political ally the Green movement are increasingly vocal about the need to reflect the value of these services directly in real policy. Such an approach would, for example, mean not funding such projects as the Three Gorges Dam which directly deplete and disrupt ecoregions on a huge scale. This debate precedes economic analysis of the services, which was in part motivated by the observation that human instinct and economic analysis very often yielded quite different impressions of the value of such ecosystems.
One criticism of this analysis is that it is largely conducted by those who have some association with Gaia philosophy and human development theory and one or more political movements seen to have an ideological bias in favor of a higher valuation for nature's services than would be implied by a more neutral point of view. Accordingly, many of the debates now focus on metrics and indicators on which both advocates and detractors of monetary reform can agree. These are in general indistinguishable from debates about measuring well-being to determine what constitutes real economic development, that is, the amount of money required to live the same way, and other debates regarding the social welfare function and what constitutes wealth.


Reflections of African culture are prominent at Imani Circle Charter School, located at Greene Street and Chelten Avenue in Germantown. Imani is one of several Philadelphia charter schools with an African-centered approach that shapes the curriculum and the school environment.
The school describes itself as "a community-based public school which uses an African-Centered approach to teach Reading, Math, the Sciences and Technology."
Here, African-language greetings punctuate the hallways and classrooms. Paintings and framed artwork of legendary African American figures, historical events, and places decorate the walls. Tables are accented with mustard-yellow mud cloth and wooden "Circle of Friends" statues. Through these and other everyday sights and activities, students can learn about aspects of Africa throughout the day.
The door of each classroom carries the name of a current or historic African nation, people, or tribal territory - Mali, Xhosa, Zulu, or Shona. Inside, the students deliver greetings in the language of that nation or community, and learn what region of the continent the territory is based and the way of life of its people, such as agriculture or fishing. Each teacher has researched his or her classroom's territory and teaches elements of its life throughout the year.
Imani was founded by CEO Francine Fulton in 2000 to provide such an African-centered focus. Therefore, Imani is different from District schools in working to integrate elements of African culture into so many aspects of the life and operations of the school.
For example, the principles of Ma'at - an ancient Egyptian code of ethics - of which Imani focuses on seven (faith, balance, truth, order, reciprocity, righteousness and justice) permeate much of the interaction here, from how a class forms a line to how the computers in the resource room are arranged.


Originally the infantry regiment of most armies was a force of ten 100-man
companies, with a total firepower of about 1,000 muskets, capable of delivering
five volleys per minute with highly trained men. From this force the regiment
has developed into a miniature division. This is particularly true of the German
infantry regiment, which was to a considerable extent, the model of our own.
The underlying principle of German organization is that each infantry unit,
from the smallest (squad) to the largest regiment), must be so armed and equipped
as to be tactically self-sufficient in combat. The tactical self-sufficiency of the
German infantry regiment is best illustrated by comparison with the German
infantry division, as follows:
||Three Infantry Battalions
||Three Infantry Regiments|
||Infantry Howitzer Company
||Division Supply Force|
Note from the above that every unit shown under the infantry regiment
belongs to the regiment organically and is composed of infantrymen. Also that
the infantry regiment is but one of the three infantry regiments shown under the
b. Infantry Regiment
The regiment consists basically of regimental headquarters, headquarters
company (mounted, communication, and engineer platoons), three infantry battalions
as above, an infantry howitzer company, an antitank company and a light column.
Numbers and minor details are subject to constant change and to the circumstances
of war, altered requirements, and losses.
The mounted platoon and communication platoon of headquarters company
are armed with rifles and pistols. The engineer platoon of headquarters company
is armed with seven submachine guns and three light machine guns in addition
to rifles and pistols.
Weapons of infantry battalions are discussed hereafter.
The infantry howitzer (13th) company has six light 75-mm and two heavy
150-mm infantry howitzers. The personnel is armed with rifles and pistols. The
75-mm infantry howitzer fires a 12-pound, while 150-mm infantry howitzer fires
an 85-pound projectile.
The antitank company may have either 37-mm, 50-mm or 75-mm antitank
guns or mixtures of 37's and 50's or 50's and 75's. The 37-mm antitank gun
penetrates two inches of armor at 400 yards at 90-degree angle. Special
armor-piercing projectile "AP 40" penetrates 2 1/4 inches at same range. The 50-mm
antitank gun penetrates just over three inches of armor at 500 yards at a 90-degree
angle. 75-mm antitank gun penetrates 4 1/2 inches of armor at 500 yards at a
90 degree angle.
The light column personnel is armed with rifles and pistols. Two light
machine guns may be provided for local and antiaircraft protection.
c. Special Companies and Units
(1) Headquarters Company:
The German infantry regiment has gone even farther than ours in some
respects. Their headquarters company contains, like ours, a communication
platoon (telephone and radio) and a reconnaissance platoon (mounted platoon). Unlike
ours, the German reconnaissance platoon may be mounted on horses, or in some
regiments on bicycles or motorcycles. Although it consists of infantrymen, this
platoon is in effect, a platoon of cavalry.
Moreover there is a unit which the American regiment does not possess -- a
strong engineer platoon of one officer and 66 men (10 additional men for transportation).
(2) Howitzer Company:
The infantry howitzer company is the 13th company of the regiment. This
company consists of infantrymen and should not be confused with artillery even
though the company functions as artillery. Need for this type of company in the
infantry regiment was brought out in World War I. The company has six light
(75-mm) and two heavy (150-mm) infantry howitzers. This mixed company has
some advantage over our own 105's, particularly in difficult or forest-covered
country where ranges are relatively short. The 150-mm infantry howitzer
projectile has about three times the power of our 33-pound 105-mm projectile.
(Both German howitzers have a maximum elevation of over 70 degrees). In more
open country our motorized 105's would have the advantage due to their greater
range and mobility.
Normally, each battalion in the front line will be supported by two light
(75-mm) infantry howitzers. The remaining howitzers are used at points where
they can support the main effort in the attack or in the defense; they are placed
in positions where the main effort is anticipated.
(3) Antitank Company:
Originally the German antitank company, which is organically a part of the
infantry regiment, had 12, 37-mm antitank guns and four light machine guns. The
37-mm antitank gun has been the model on which our own 37-mm gun was based.
The German gun, besides firing high explosive and armor piercing shells, also
fires a stick bomb with an armor-piercing hollow charge in the head of the bomb
and vanes at the end to guide the projectile. It is inaccurate at ranges over 150
yards. The stick bomb relies on hollow-charge, focused, blast effect for penetration
of armor rather than muzzle velocity.
At present the trend is toward 50-mm antitank guns and even 75-mm antitank
guns for the infantry. Therefore there are varied organizational differences
between antitank companies. Some companies have nine 37-mm antitank guns and
two 50-mm antitank guns while others have only the 50-mm antitank gun of which
there are nine in a company. Still other companies have a proportion of 50-mm
and 75-mm antitank guns on a basis of 6 and 3, or 3 and 6.
(4) Light Column:
Unlike the American regiment, the German regiment has its own organic,
mixed horse-drawn and/or motorized supply unit. This unit, known as the "light
infantry column" furnishes the regiment with all supplies except rations which
are carried by the ration trains II of the battalions. The light column carries a
reserve of all types of ammunition used by the regiment. The first reserve of
ammunition is carried within each company. Ammunition, equipment and supplies
are received by the light column from the transport columns of division (part of
the division supply force). The light column, after receiving ammunition, equipment
and supplies at distribution points, usually proceeds to designated points where
the transport of the individual companies will receive the ammunition, etc. Thus
the light column is the connecting link between the companies and division.
(5) Medical Service
The medical detachment comprises a force of about fifty enlisted men,
with a major or captain at regimental headquarters, a captain and a lieutenant,
or two lieutenants, with each battalion, and a medical NCO per rifle company,
assisted by one stretcher-bearer leader at company headquarters and one each with
the three rifle platoons. The medical organization of the special companies such
as the antitank, is not exactly known. Division ambulances go direct to battalion
One noticeable feature of the organization of the German infantry regiment
is the lack of an antiaircraft weapon like our .50 caliber machine gun. The German
have a 20-mm gun which serves both as an antiaircraft and antitank weapon and
can be used also as a heavy machine gun. However this weapon is not included
in the infantry regiment. For antiaircraft protection the Germans use their
machine guns. A special antiaircraft tripod is provided for the light machine guns
on the scale of three per rifle company and these offer good possibilities for
antiaircraft fire. Each machine gun company has three special mounts which are
set on wagons which take two machine guns each in a twin mount and thus serve as
a dual antiaircraft machine gun while on the march.
The Germans also do not have any weapon which approximates our
"bazooka" (rocket launcher AT). Wide use is made of antitank rifle grenades and
stick bombs may be fired from the 37-mm antitank gun. Both types of infantry
howitzers fire hollow-charge ammunition.
d. Infantry Battalion:
The infantry battalion consists of a battalion headquarters with communication
section, three rifle companies and one machine gun company as above. The
battalion has also the trains mentioned previously.
(1) General Description
Battalion receives support from the regimental units such as howitzer
company, antitank company, engineer platoon etc.
Each of the three infantry battalions within the infantry regiment is a
miniature regiment. The battalion is likewise organized on the principle of
tactical self sufficiency. It consists of a headquarters with communication section,
three rifle companies of three platoons each and a machine-gun company containing
12 machine guns on the heavy mount, together with six 81-mm mortars.
Each rifle company has 12 light machine guns, about 135 rifles, three
antitank rifles, three light (50-mm) mortars, 16 submachine guns and a number of
pistols. As mentioned previously, the company is composed of three platoons.
Each platoon has four rifle squads with one light machine gun each and a light
mortar squad with one 50-mm mortar. The antitank rifles are with the company
headquarters. One man in each squad is equipped with a rifle grenade discharger
which fires both anti-personnel and armor piercing grenades. Thus, in the platoon,
there are both flat-trajectory weapons (rifles and machine guns) and high-trajectory
weapons (light mortars and anti-personnel grenades fired from rifle-grenade
dischargers). Each squad leader, platoon leader and company commander
of rifle companies carries a submachine gun.
The heavy machine guns of the machine-gun company are the same caliber
as the light machine guns of the rifle companies. The guns are identical except
that a bipod mount is used with the light machine gun whereas a tripod mount is
used with the heavy machine gun. Thus the machine gun company is the supporting
unit of the infantry battalion. Each rifle company receives heavy machine gun and
mortar support from the machine gun company.
The communication section with the battalion has telephones, radios and
The battalion, as well as the companies within the battalion, has trains
which form the supply units of the battalion and companies. Thus the battalion
has a combat train, ration train I, ration train II and a baggage train whereas the
companies have the same trains with the exception of ration train II. The company
combat train always has the field kitchen and several other wagons for equipment,
etc. The ration trains (except ration train II) haul rations for the field kitchens
of the battalion, headquarters personnel and the companies. The ration train II
hauls rations from a division distribution point and distributes these rations to
the ration train I and the ration trains of the companies. The baggage trains of
the battalion and companies haul the extra baggage of these units. This means
such extra baggage as clothing, extra individual equipment, administrative equipment, etc.
The battalion discussed is one of the three battalions in the regiment. The
first battalion consists of companies 1 - 2 - 3 and 4. The second consists of
companies 5 - 6 - 7 and 8 while the third battalion consists of companies 9 - 10 - 11
and 12. Companies 4, 8 and 12 are the machine-gun companies with the other
nine companies being rifle companies.
(2) Rifle Company:
The rifle company consists of a company headquarters, three rifle platoons
and antitank rifle section and the combat, ration and baggage trains.
The company commander is armed with submachine gun. The total armament
includes 16 submachine guns, 12 light machine guns, three light mortars and
three AT rifles in the company.
The antitank-rifle section has three antitank rifles (.31 caliber) capable
of penetrating 1.3 inches of hardened armor at 100 yards. The new, modified
antitank rifle is a grenade-firing rifle which fires both armor-piercing and
anti-personnel grenades. Heavy AP grenade will penetrate 2 inches of armor.
The combat train contains a field kitchen and two wagons for the men's packs,
etc. The ration train consists of one ration wagon while the baggage train consists
of one truck.
(3) Rifle Platoon:
This platoon has four squads as above, and a light mortar squad as well as
a platoon headquarters. The platoon leader is armed with submachine gun. The
light mortar squad has one light (50-mm) mortar firing two-pound projectiles
to a maximum range of 550 yards. The platoon is served by one wagon (composed
of two carts) for transportating heavier weapons and equipment on the march.
(4) Rifle Squad:
The basic weapon of the rifle squad is one light machine gun (.31 caliber).
The squad leader is armed with a submachine gun (.35 caliber) while the other
men are armed with rifles or pistols. (The rifle is .31 caliber; the pistol, .35
caliber). One man per squad has a rifle-grenade discharger firing both
anti-personnel and armor-piercing grenades. Hand grenades are issued when necessary
(egg type, standard potato-masher type and smoke hand grenade).
(5) Machine Gun Company
This consists of a company headquarters, three heavy machine-gun platoons
(four heavy machine guns each) and a mortar platoon (six 81-mm mortars) as well
as a combat and ration train. The baggage is hauled by battalion baggage train.
The heavy machine gun is same caliber as light machine gun, with a high
cyclic rate of fire (900 rpm with model 34 and 1,150 rpm with model 42). Because
it is air cooled, the practical rate of fire is 300 to 350 rounds per minute.
The heavy mortar fires a 7.75-pound projectile, HE or smoke.
The machine gun company supports three rifle companies. Heavy machine
guns are attached to rifle companies by platoons (four guns) or sections (two guns).
Heavy mortars are attached to rifle companies by sections (two mortars).


The debate over whether or not glyphosate is carcinogenic continues with a joint meeting of the Food and Agricultural Organization Panel of Experts on Pesticide Residues in Food and the Environment and the World Health Organization Core Assessment Group of Pesticide Residues releasing an assessment that says glyphosate, diazinon and malathion were “unlikely to pose a carcinogenic risk to humans from exposure through diet.”
This follows the release of a report earlier in May that found no association between glyphosate and cancer. The report was released by EPA and then taken down.
In March 2015, the International Agency for Research on Cancer in Lyon, France, “classified glyphosate as ‘probably carcinogenic to humans.’”
“Once again, an impartial peer review has found that IARC’s classification of glyphosate, diazinon and malathion was, at best, questionable. And frankly, CLA views IARC’s findings as an unnecessary threat to farmers and the global supply of food,” stated Jay Vroom, president and CEO of CropLIfe America. “In the U.S., we are eagerly awaiting the U.S. Environmental Protection Agency’s (EPA) new risk assessment for glyphosate. We urge EPA to consider the real risk of products and to use broad data sets, rather than responding to outside political pressure from activist groups.”
IARC is not a regulatory body and it used a very narrow set of data to assess potential for hazard only, CropLife America says. Regulatory organizations assess the actual risk of exposure from products or ingredients at appropriate use levels and human health risk.
All crop protection products must undergo extensive health and safety assessments by regulators before they are approved for use.
Source: CropLife America


STANFORD, Calif. After having downplayed the benefits of silicon-on-insulator transistor technology for years, Intel Corp. now will spin its own version, saying it will address circuit designers' gripes with SOI while retaining the technology's low-power, low-capacitance attributes. At the same time, the company has chosen a high-k gate dielectric to replace silicon dioxide, which many experts believe will become too thin to be effective below the 0.10-micron node.
Intel's decision to use silicon-on-insulator technology comes after five years of study and is considered a key step in reducing transistor leakage and voltages. By implementing its own brand of SOI with high-k gate dielectrics, the company claims it will be able to build transistors that operate at terahertz speeds within the decade, while keeping power consumption in check.
If those changes are not made, Intel predicts, the heat generated by its microprocessors will slope upward exponentially, reaching the power density of a nuclear reactor before 2010.
"My job is to make that flat," said Gerald Marcyk, director of components research at Intel. "There is no fundamental physical problem with making these transistors really small and fast. The problem is, they start to consume too much power."
Intel's move to incorporate new materials in its manufacturing process is part of its multipronged battle with power dissipation. At the circuit level, the company is starting to implement body biasing for a greater range of voltage thresholds. Its architectural engineers, meanwhile, have built in latent-multithreading technology that will be activated in Pentium-4 systems next year, and they're looking into extending the concept for microprocessor cache hierarchy.
At the process technology level, Intel is looking to SOI as one means of keeping power under control without thwarting the move to terahertz transistor-switching speeds. But Intel is putting its own twist on SOI by using a much thinner insulator substrate, which it calls a depleted substrate transistor. More commonly referred to as fully depleted SOI, the technique allows the transistor's source and drain to sit directly above the insulator layer, effectively isolating the silicon body between the source and drain.
By contrast, IBM Microelectronics acknowledged as the pioneer in commercializing SOI technology uses partially depleted SOI, which leaves a sheath of silicon between the insulator at the bottom and the source/drain terminals above.
Marcyk claimed fully depleted SOI offers better junction capacitance, lower off-state leakage, fewer soft errors, lower operating voltages and lower gate delay than the partially depleted variety. Most important, he claimed, it eliminates the so-called floating-body effect associated with conventional SOI, or the tendency for unwanted charge to build up in the transistor body.
The floating-body effect vexes some circuit designers because the threshold voltage starts to depend on earlier states, in a phenomenon known as the history effect.
"I do know some engineers are still worried about the history effect, so there will be some 'show-me' pushback on the process," said Gary Smith, chief EDA analyst at Gartner Dataquest. "Until it's proven, engineers will be cautious."
But IBM fellow Ghavam Shahidi said the history effect has been overblown. "The history effect is less [of an issue] for fully depleted SOI, but it is a very small effect to begin with, and it's hard to measure. I'm not sure why Intel is making it a big deal," he said.
In fact, fully depleted SOI is not necessarily immune from floating-body effects, Shahidi contended. "If the source and drain are high, the body will charge up; that's a condition you see even in fully depleted [SOI]," he said.
Moreover, fully depleted SOI worsens short-channel effects, making it hard to attain multiple threshold voltages. And analog circuits still need to make contact with the body, which can't be done with fully depleted designs.
I think this shows [Intel's] lack of experience," Shahidi said.
Intel did acknowledge that fully depleted SOI creates higher resistance in the source and drain terminals because there is no silicon touching the cobalt-coated terminals. To counteract that effect, the company said, it will grow thicker source and drain regions, thereby lowering the resistance and boosting drive current.
Steeper slope, lower leakage
The one-two punch of fully depleted SOI and raised source/drain regions is claimed to give the transistors a steeper subthreshold slope and much lower off-state leakage than conventional SOI and bulk silicon. Marcyk said partially depleted SOI has a 100x higher off-state figure than fully depleted SOI. Raising the source/drain regions improves drive current 30 percent for a given voltage threshold and given geometry, he said.
"What we're saying is that fully depleted SOI is the right answer, and we think everyone will have to do this in three to five years," Marcyk said.
Going to fully depleted SOI means wafers will have to be capped by layers of silicon as low as 30 nanometers thick, which is less than a third the thickness of partially depleted SOI. Wafer manufacturers' ability to control that ultra-thin layer is a "significant concern," Marcyk acknowledged.
Answering the call
But wafer manufacturer Soitec, which just received a multimillion-dollar order from Advanced Micro Devices Inc. for SOI wafers, claims it is up to the task. "We just announced in July that we can get layers of silicon as thin as 30 nm," said Soitec president Andre Auberton-Herve.
Intel's decision to adopt high-k dielectric material for insertion beneath the transistor gate isn't surprising, since most IC manufacturers are moving in the same direction. High-k dielectric films promise to let chip makers grow a thicker insulation layer to reduce leakage while keeping capacitance constant.
For that purpose, Intel selected zirconium oxide, which has to be built up in single-layer molecules using atomic-layer chemical vapor deposition. The method lets Intel reduce gate leakage by 10,000 times, without any change in capacitance, Marcyk said.
But the jury is still out on high-k dielectrics. Among the questions is the material's ability to withstand high temperatures when the source and drain regions are being doped.
"Zirconium is one of the top materials, but I don't see what makes it stand out yet," said Shahidi of IBM.
Intel said it now has a chemical vapor deposition tool that can handle the high-k material for use with 300-mm wafers. And several equipment vendors are busy working on atomic-layer CVD tools, said Dean Freeman, principal analyst at Gartner Dataquest.
Marcyk said Intel plans to introduce its fully depleted SOI, raised source/drain transistors and high-k gate dielectric materials at different stages in the 90- and 65-nanometer process technology nodes, but he would not disclose the sequence of introduction. Intel expects to move to the 90-nanometer node in 2003 and then to 65 nm in 2005.
Freeman said it may make sense to integrate the high-k dielectric materials first. SOI "is not that difficult to integrate, because you're still processing a standard wafer, but from a device performance standpoint it will probably require more understanding," he said.


The history of American music is the cultural history of the United States.
By tracing the roots of original American art forms like jazz and blues and the development of genres such as R&B, soul, country, folk and rock, we understand the history of American culture and the significant role music played in developing and reflecting that culture. From field hollers to gospel to blues to rock and ragtime to swing to bebop to funk, the history of music tells a complicated and compelling story of America.
At Music Preserves Foundation, we attempt to follow the music and learn about our shared history through music, exploring regional music, prominent and lesser-known artists, significant musical events and historic venues.
Muddy Waters is a classic example of the history of American music teaching us cultural history. His journey from the rural Mississippi Delta to the nightclubs of Chicago, from gospel to electric blues, tells the story of America during the 20th century.
Music Preserves Foundation explores the roots and history of American music through blog posts, interviews, podcasts, educational curriculum for schools and collaborative music and art events.
Join us as we explore the history of American music.


OT Helps Children Successfully Cope With Sensory Processing Disorder
Sensory processing disorder is when the brain has difficulty receiving and responding to information obtained via the senses. Although it’s not formally recognized as a distinct medical diagnosis, our occupational therapists in Fort Myers know it’s very real and something with which many children struggle, impacting the ability to successfully engage in everything from toothbrushing routines to consuming a healthy diet to paying attention to a math lesson or playing a game with peers.
While it’s most usually co-occuring with conditions like autism or ADHD, sensory processing disorder can present in children without any disability at all (research suggests 10 to 55 percent of children without a diagnosed disability have difficulty in this area).
It can manifest in the form of being overly-sensitive to certain environmental factors. For example, someone with sensory processing disorder may be so keenly aware of sounds or light touches, it may to them seem physically painful. A child with sensory processing disorder might also seem uncoordinated, have difficulty engaging in play or conversation or have difficulty telling where there limbs are in space. Certain textures, tastes, smells, sounds, brightness and movement can become overwhelming, and sometimes make an otherwise ordinary task seem unbearable.
A recent analysis published in the American Journal of Occupational Therapy examined the state of research on sensory integration for children, finding that in recent years, this area of academic study has shifted from sensory processing and integration problems to emphasizing the occupational performance challenges that result from these problems. More recent research looks at overcoming challenges in detecting, interpreting and adaptively responding to sensory stimuli affecting a child’s ability to participate occupations that are both meaningful and valuable. “Participation” here could mean anything from entering a highly complex professional field of study to engaging in key “occupations” of daily living, such as getting enough rest and sleep, playing, adapting to a school environment and participating in basic social interactions.
This area of study is relatively new from a medical standpoint, but the good news is the quality and rigor of these analyses is steadily improving, and the more we know about this condition, the better we are at finding effective methods to treat it.
Regardless of the exact focus of the study, researchers have soundly concluded that occupational therapy interventions for sensory processing disorder – particularly for children – have a positive outcome.For example, a 2012 case study published in the AJOT noted remarkable changes in adaptive behaviors of a child with autism during an intensive 10-week occupational therapy program that used a sensory integrative approach. The 5-year-old child had demonstrated hyperresponsivity to auditory, tactile and oral-tactile sensory inputs (i.e., startled easily, became distressed during loud conversations, showed distress anytime someone groomed his face or while touching certain textures or being touched by another person, was an extremely picky eater and almost always refused new foods and sought out movement activity that interfered with his daily routine). He scored low in communication (receptive and expressive), personal daily living skills, interpersonal relationships and coping skills.
The intensive occupational therapy program, within which two registered and licensed occupational therapists worked, involved:
- Presenting sensory opportunities (i.e., swinging, diving into a ball pit, exposure to new foods, playing with sand, practice on a balance beam, spinning to music, practice with various oral stimuli);
- Facilitating self-regulation of attention, emotion and arousal level;
- Letting the child collaborate on activities they would engage in;
- Tailor those activities to the just-right challenge;
- Do all this by creating a context of play.
Researchers found that even within this relatively brief 10-week window, they found the child was able to participate more successfully in dressing. His bedtime routine no longer required excessive rocking (and he could fall asleep independently). His attention in school was “so much better,” according to his teacher, and he was not having as much difficulty interacting with peers. His mother reported being able to make trips and make unexpected stops without him having a complete meltdown. He was less distractable and, his mother reported, seemingly happier.
Occupational therapy for sensory processing disorder typically takes longer than 10 weeks. Even this child will likely require more of it to cope with new challenges. But having this foundation from an early age can help children better cope – and attain higher levels of success – throughout their formative, teen and adult years.
FOCUS offers pediatric speech therapy in Fort Myers and throughout Southwest Florida. Call (239) 313.5049 or Contact Us online.
State of the Science of Sensory Integration Research With Children and Youth, Dec. 2017, The American Journal of Occupational Therapy
More Blog Entries:
Why Our FOCUS Speech and Occupational Therapists LOVE Puppets, April 2, 2018, Fort Myers Occupational Therapists for Children Blog


Solve this problem: Which is the better buy - 5 boxes for $6 OR 8 boxes for $10 ? 1. Explain how you do this problem from beginning to end. 2. Tell the answer. 2. Name the strategy you used to find the answer (Common Multiple or Unit Price) 3. Explain why you chose this strategy over the other one.


That’s pretty much what the history of gender difference science has told us, according to a new book by British science journalist Angela Saini.
In the introduction chapter of Inferior, the British science journalist Angela Saini says very poignantly that at the heart of her book is a “hushed uncertainty… a dark, niggling feeling that we aren’t the same”. The dangerous part of letting such uncertainties fester is that, once in a while, this delicate equilibrium gets messed up – as it was very recently by James Damore. In his now infamous ‘Google memo’, the former Google employee made an impassioned plea to the company to stop being in denial of what science tells us about biological differences between the sexes. To spare us the trouble of finding out what these differences are, he lists them out himself:
- Women on average show a higher interest in people and men in things,
- Women on average are more cooperative,
- Women on average are more prone to anxiety,
- Women on average look for more work-life balance while men have a higher drive for status on average,
- Women on average are more gregarious than assertive,
- Women on average are more agreeable.
In all likelihood, Damore meant well. He genuinely felt that there was something revolutionary in his ideas that could improve the future of his company. There have been plenty of clever rebuttals to Damore’s memo, which he’d titled ‘Google’s Ideological Echo Chamber – How bias clouds our thinking about diversity and inclusion’. But the perfect and most comprehensive one was coincidentally published shortly before he even wrote it. One may speculate that if only Damore had got himself a copy of Angela Saini’s book, Inferior: How Science Got Women Wrong and the New Research That’s Rewriting The Story, in time, the painful ‘Google memo’ may never been written.
Damore’s memo advocates paying more attention to the science investigating sex differences and Saini does exactly that in her book. The results are not always what you’d expect or what you’d want them to be. Stories behind the scientific studies that form the basis of most stereotypes are more complex than we think. Oft-seen headlines like ‘men are biologically built to cheat’ actually might be a gross extrapolation of an experiment involving fruit flies in a lab.
More interestingly, Saini also delves into the lives of the people behind this research and their inherent biases. “Having more women in science is changing how science is done,” she says, and she illustrates these with stories historical and contemporary. A perfect example of this is the case of primatology – the study of primates. Until the 1970s, the field of primatology was male-dominated. But only when women finally entered the field did many important phenomena to come to light.
For example, it took Amy Parish’s observations for it to be recognised that bonobos, which, along with chimpanzees, are humans’ closest primate relatives, live in communities where females dominate, have multiple sexual partners and often attack males. These had been documented by zoos and vets all over but Parish found that each observer had thought of this as a freak incident. “We built all of our models of evolution based on a chimp model. Patriarchal, hunting, meat-eating, male-bonding, male aggression towards females, infanticide, sexual coercion. Bonobos turned all this on its head,” Parish tells Saini in the book. Today, primatology is seen as a female-dominated field, with big names like Jane Goodall and Dian Fossey having made significant contributions.
The other great value in Saini’s book is how she goes into not just landmark studies but also their aftermath and attempts to replicate them. Shockingly, quite a few of these major studies have been followed by similar studies where the initial results could not be reproduced. In some cases, contrasting results were observed. We all have it drilled into our brain that “science says” that men are more naturally promiscuous but how many of us know that the very experiment that this saying is based on was later replicated to show that females are just as promiscuous? Saini is disheartened to find out that scientists themselves are sometimes so attached to their own principles that they don’t even bother reading replication studies, which have shown up serious gaps in many experiments.
Even though scientific research is what takes this book forward, the themes are universal enough for anybody to get hooked. And it’s less than 250 pages long. It helps that Saini frequently draws parallels to topics of current relevance, like the Delhi gang-rape and female genital mutilation.The quantity of information packed in the book is tremendous and it could have been really easy for discontinuities and rambles to slip in, but if they did, I didn’t notice. Saini manages to tell the story without losing her eye on the plot.
The book will provoke readers to rethink assumptions about gender that we have knowingly or unknowingly taken refuge in for most of our lives. It exposes serious flaws in the scientific method when it comes to gender differences, and that scientists and the media need to be much more discerning. The only thing that science has definitively told us so far is that binary notions of ‘the average woman’ and ‘the average man’ are far too simplistic to describe the phenomenon of gender. So Saini’s investigation is proof that Damore is guilty of the very accusation that he places on Google: of being in denial of what science tells us about biological differences between the sexes.
Our society has a lot of understanding to gain by reading Inferior. It is a book that is definitely worthy of being translated into many other languages.


What Is Arrhythmia? Symptoms, Risk Factors, and More
Your heart typically beats with a specific rhythm. Arrhythmia is a problem with that rhythm, whether it beats too quickly, too slowly, or irregularly. It's a common occurrence that is usually harmless, but at times it can cause serious problems.
Here's what you need to know about arrhythmia, including when to see a doctor.
What Is Arrhythmia? Causes and Symptoms
Electric pulses in your body control the heartbeat, and it's when these pulses get out of sync that arrhythmia occurs. When the heart is out of rhythm, it doesn't pump blood efficiently, which can hurt the heart and affect the oxygenation of organs throughout the body. The American Heart Association explains that an arrhythmia increases your risk of heart attack or cardiac arrest.
The symptoms of arrhythmia include:
- A heartbeat that is too fast or too slow
- Skipped beats
- Chest pain
- Feeling short of breath
- Feeling lightheaded or like you're going to faint
Risk Factors for Arrhythmia
The National Heart, Lung, and Blood Institute describes the risk factors for arrhythmia, including:
- Older age
- Heart conditions that have damaged the heart, such as a prior heart attack, heart failure, or a congenital heart defect
- High blood pressure
- Sleep apnea
- Infections that reach the heart
- Thyroid imbalance
- Prescription drug use
- Recreational drug use, from caffeine and nicotine to cocaine
- Chemical imbalance in the bloodstream
Many people have arrhythmias that don't need medical intervention. In cases where the arrhythmia needs treatment, prescription drugs are often sufficient to address the issue. In more extreme cases, devices such as a pacemaker or implantable cardioverter defibrillator may be surgically implanted to maintain the rhythm of the heart. There are also procedures such as ablation to identify and destroy the cells in the heart that cause the irregular heartbeats.
When to See a Doctor
If you have any of the symptoms of arrhythmia, or have concerns about your heart, the first step is to make an appointment to see your doctor. If you have chest pains, shortness of breath, or fainting, your symptoms are considered an emergency and you need immediate medical attention.
Your doctor will likely order several tests to be performed at the medical facility, such as an echocardiogram, which is a painless procedure that uses sound. They may also order a stress test, which monitors your heart while you exercise. There are also different types of monitors that your doctor may send home with you to monitor your heart as you go about your day.
If you are concerned that you are at risk of developing arrhythmia, discuss it with your doctor. You can start by addressing your risk factors. You can make many changes at home, such as eating a heart-healthy diet, dialing back your sodium intake, monitoring your blood sugar if you have diabetes, and reducing or eliminating your use of caffeine and nicotine. While you may not have control over all risk factors, such as age, making healthy choices will help you mitigate your risk of arrhythmia and improve your health overall.
Posted in Heart Health
More articles from this writer
*This information is for educational purposes only and does not constitute health care advice. You should always seek the advice of your doctor or physician before making health care decisions.


Mercury Research Strategy
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The Mercury Research Strategy summarizes the human health and ecological risks posed by mercury and methylmercury, and indicates that mercury needs to be considered at local, regional, and global scales. It identifies the key scientific questions of greatest importance to the Agency, and then describes a research program to answer those questions. The key scientific questions cover: (1) transport, transformation, and fate, (2) risk management for combustion sources, (3) risk management for non-combustion sources, (4) ecological effects and exposure, (5) human health effects and exposure, and (6) risk communication. The goal in addressing the questions is to reduce scientific uncertainties limiting EPA's ability to assess and manage mercury and methylmercury risks. The exposure route targeted in the Mercury Research Strategy involves fish consumption where mercury is: released to the air, transported and deposited on land and water, converted to methylmercury in water bodies, consumed by fish, and then accumulated in mammals, including humans, that eat fish.
A number of scientific and technical studies contributed to the strategic directions and the key scientific questions posed in the Mercury Research Strategy. One of the most important documents was the Mercury Study Report to Congress which described the magnitude of mercury emissions in the United States, identified mercury emission sources, assessed the health and environmental implications of those emissions, and evaluated the availability and cost of technologies for emission control. It is the most comprehensive human health and environmental investigation of mercury and methylmercury available and serves as the foundation for EPA's understanding of mercury risk assessment and risk management issues. Another important document was the National Academy of Sciences report on the Toxicological Effects of Methylmercury. This report confirmed EPA's Reference Dose (RfD) of 0.1 micrograms per kilogram of body weight per day as a scientifically justifiable level for protecting human health from the adverse effects of methylmercury.
A team of scientists from ORD's national laboratories and centers, the Office of Air and Radiation, the Office of International Activities, the Office of Prevention, Pesticides, and Toxic Substances, the Office of Solid Waste and Emergency Response, and the Office of Water prepared the Mercury Research Strategy. Technical staff from EPA's Regions I, IV, V, IX, and X also contributed to the writing effort. An internal review was conducted by the Associate Directors for Ecology at ORD's three national laboratories and the National Center for Environmental Assessment in November 1998. An external peer review was performed by a group of experts at a work shop in Washington, D.C., on December 9 11, 1999. The strategy reflects the recommendations of these internal and external peer reviewers, as well as comments received from individuals on the Committee on Environment and Natural Resources.
This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.


The term "Advanced Opportunities" can be confusing because it means different things in different contexts and within different points in a student's education. For example, in Elementary School, there are Advanced Learning Teachers who may teach a variety of topics (Teachers are often referred to as "ALP" teachers). In Middle School, there may be Advanced Math, Language Arts, and other classes. In High School, however, the term encompasses even more variation.
A very important distinction in High School is that "Advanced Opportunities" more often refers to receiving credits (and often funding) towards college courses. In order to received college credit for an AP (Advanced Placement) course, a student must receive a score of 3 or higher (out of 5) on the AP exam for that course. And many colleges require a score of at least 4. Each college or university has a guide to how AP exam scores transfer into credits at their institution that may be found on their websites.
"Honors" Classes, on the other hand, are technically "advanced" courses (i.e. more rigorous) but don't qualify for college credit, although their grades may be "weighted" so that if a student receives a 3.0 in an Honors class, it actually is reported as a 3.5 on their transcript.
Dual credit courses (sometimes known as concurrent credit or dual enrollment) are classes for which the student receives high school and college credit simultaneously. These courses may be available at the high school, online through a course provider (such as the Idaho Digital Learning Academy - IDLA), online from the college, or on the college campus. Check with your school counselor to see what opportunities your student may have. Also, check with the counselor to see how dual credits are transcribed at your high school. Many schools transcribe the credits at half their college credit value (3 college credits = 1.5 high school credits). This may vary by school.
AP Curricula is determined by CollegeBoard. This means that AP teachers across the country teach the same thing.
Honors Curricula is determined by the State, and individual schools, districts, and teachers.
Dual credit curricula is determined by the credit-granting college and the schools, districts, and teachers.
The State Board of Education defines the "Advanced Opportunities" that are available in Idaho. The State Department of Education determines the funding available for these courses/credits.
Based on HB458 in the 2016 Legislature, all the programs have merged into one; it will still be called "Fast Forward".
July 1, 2016
(No pro-rating for prior program use)
7-12 beginning the summer after 6th grade
Participation Form must be signed by the student / parent, kept on file at school district
- Overload classes
- Dual Credit classes
- Credit bearing exams (AP, IB, CLEP)
- Professional – technical exams (CNA, A+, etc.)
- Post-Secondary scholarship for early graduates
Funding mechanism: State Department Advanced Opportunities Portal
Payments: Directly to state entities / to SD for private entities
Payments: Made at the end of each semester
NOTE: As of July 2016, "8-in-6" Program, Mastery Advancement Program (MAP) and Dual Credit Early Completers Program have merged into "Fast Forward" Program
IDTransfer is a website developed by Idaho public and community colleges and state universities to help students learn what credits will transfer. Links at the bottom of the page link to Transfer information for various North Idaho schools.
Coeur d'Alene School District
Post Falls School District
Lakeland School District


Piles, another term for haemorrhoids, are swollen blood vessels in or around the anus and rectum. Haemorrhoid swelling occurs when there is an increase in the pressure in the small vessels. Therefore, the vein walls become stretched, thin, and irritated by passing bowel movements, and this is when piles develop.
Types of Piles: Haemorrhoids are classified into two general categories:
Symptoms of piles: Generally, the symptoms of piles are not serious. They normally resolve on their own after a few days. These symptoms can also vary depending on the size, position, and grade of the pile. So before discussing the symptoms, let’s take a look at the grades. Grades are nothing but the intensity by which piles occur:
Grade 1: These are small swelling
Grade 2: These are larger swellings
Grade 3: In this case, it hangs out from the anus during bowel movements
Grade 4: In this case, the hanging from within the anus is permanent
The most common symptom is bleeding after going to the toilet or to pass stools. A lump in and around the anus, a feeling that the bowels haven’t emptied completely, watery discharge from the anus, an itchy or sore skin around your anus and pain and discomfort during or after a bowel movement are some of the common symptoms.
Cause of piles: Anyone at any age can be affected by piles. However, they are usually more common in elderly people and during pregnancy. Modern lifestyle, excessive consumption of junk food, stress, and improper eating habits accounts for a majority of anorectal complications, including piles. Diet has a pivotal role in both causing and preventing piles. People who eat high fiber diet are less likely to get haemorrhoids, but people those who prefer a diet high in processed foods are at greater risk of piles. There can be a lot of reasons. However, some of the basic reasons are low fibre diet, prolonged sitting on toilet, indigestion, obesity, diarrhoea, long-term coughing, having a family history of piles, excessive heavy weight lifting, spinal cord injury and lack of erect posture.
Prevention of piles
The preventive measures include:
Stapler Surgery For Piles
Stapling is used to treat prolapsed hemorrhoids. A surgical staple fixes the prolapsed hemorrhoid back into place inside your rectum and cuts off the blood supply so that the tissue will shrink and be reabsorbed. Stapling recovery takes less time and is less painful than recovery from a hemorrhoidectomy.
Small changes in lifestyle can make bowels regular and faeces soft, thereby preventing constipation and piles. There are several lifestyle changes that may be adopted to reduce the symptoms of piles and reduce episodes of aggravated piles in susceptible individuals.


The Bancroft Ranch House Museum
The adobe house and surrounding grounds have a long history, mostly due to the presence of a nearby spring. This water source attracted people thousands of years ago to use the area. These people, the Indians presently known as Kumeyaay, left evidence of their encampments in the vicinity. The location name was transcribed by the Spanish as "Meti" or "Neti" and later changed to "San Jorge" in 1775 by the Spanish padres. The spring became known as "El aguaje de San Jorge" (Anglicized into "St. George's spring"). By the late 1830s the Indians had been removed from the area and herds of cattle and sheep grazed in the valley.
In May of 1863, Judge Augustus S. Ensworth, of San Diego, filed claim to 160 acres of land that included the spring. He built a two room adobe on the property, the first house erected by a white man in the eastern part of San Diego County. The wood used for beams and doorways was salvaged from the ship Clarissa Andrews, which had gone aground in San Diego Harbor.
Just before Ensworth's death, the ranch was sold to Rufus King Porter of San Pedro for $400. Capt. Porter, his wife Sophia, and daughter Rufina moved to the property on July 31, 1865. Rufus King Porter was the son of Rufus Porter, the founder of the Scientific American magazine, and he led a very colorful life holding numerous jobs and taking on various enterprises. He became well known for his columns about daily life, that appeared in several newspapers.
In 1866, at the urging of his daughter, Rufus renamed the area Spring Valley. In 1872, after the discovery by a scientist of a European snail (Helix aspersa) living on a nearby small mountain, Rufus named the prominent peak Mt. Helix. When, in 1885, the U.S. Post Office Department disallowed the use of two words for a post office name, Rufus submitted the name Helix and became the first postmaster in Spring Valley; the Helix Post Office operated out of his home.
In this same year, Hubert Howe Bancroft came to the area in search of a place to retire. He bought the Porter's ranch and also acquired neighboring ranches, accumulating around 500 acres. He called his property "Helix Farms." Over the next ten years, Bancroft hired workers to develop Helix Farms, planting orchards and building structures to run a ranch. A wide variety of trees and shrubs were planted including guavas, palms, olives, citrus, almonds, raspberries, blackberries, and currants. The adobe was too small to suit his family's needs when they visited the property in the summer months, so a house, known as "Cactus Cottage," was built on top of a nearby (cactus-covered) hill in 1889. Masons also constructed a "rock house" near the spring, where the children were taught. By the early 1900s, Helix Farms had become one of the largest olive ranches in southern California (many of the original olive trees can still be found in the surrounding area). Bancroft's son Griffing managed the farm since Hubert lived in San Francisco much of the time. Bancroft died in 1918 and after several years, his heirs sold the property. Much of it was subdivided into La Mesa Country Estates.
The adobe and 3.5 acres of land were purchased by the Spring Valley Chamber of Commerce in 1940. A wooden annex was built on the north side of the adobe and the building was used as a community meeting place. The Chamber was instrumental in getting the adobe designated California State Historic Landmark No. 626 in 1958, and it became known as the Bancroft Ranch House. By 1962, the deteriorating condition of the adobe required major restoration. Volunteers worked to reinforce it by bracing the walls, adding more support beams to the porch, filling in the cellar, and laying a concrete floor.
On March, 24, 1963 - just short of one hundred years after being built - the adobe was opened as a museum displaying artifacts of Spring Valley. The Spring Valley Historical Society was founded in April of that year and became the manager of the property, later purchasing the adobe and a portion of the land in 1967.