The purpose of the study was to investigate the effects of three levels of lick supplementation on the production and reproduction of cows grazing transitional Cymbopogon-Themeda veld. The study was conducted over three years (2011-2014). A total of 150 Drakensberger cows were randomly allocated to three supplementary treatment groups. These supplementation formulations are available commercially and are typical of levels used under farming conditions. In summer Treatment 1 (T1) consisted of a supplement containing 50 g phosphate (P)/kg and 150 g crude protein (CP)/kg. T2 and T3 both consisted of supplements containing 60 g P/kg and 0 g CP/kg. In winter, T1 consisted of a supplement containing 367 g CP/kg, 77.5% non-protein nitrogen (NPN) and metabolizable energy (ME) content of 5.25 MJ/kg. T2 had 466 g CP/kg, 88.7% NPN and a ME content of 4.4 MJ/kg. T3 had 475 g CP/kg, 95.9% NPN and an ME content of 2.4 MJ/kg. Traits were calf birth weight, 100-day and weaning weights of calves, cow weight at weaning, inter-calving period (ICP), conception rate and body condition score (BCS) of cows. Calf birth weight was affected by supplementation treatment only in year 3 and 100-day weight in year 2. However, weaning weight and reproductive performance were not influenced by treatment. It was concluded that the level of supplementation of each treatment group enabled the cows to operate within their target weight range; however, it was more profitable to use the T3 supplementation option.

A study was conducted to determine the supplementation and management practices of commercial beef farmers. 48 commercial farmers from the Zastron district were selected for this study out of a prospective of 60 farmers that were bona fide commercial farmers and members of Free State Agriculture. The farmers reported the following calving percentage ranges: one farmer (2.1%) between 50 and 59%, three farmers (6.3%) between 60 and 69%, 19 farmers between 70 and 79%, 22 farmers between 80 and 89% and three farmers between 90 and 99%. Preventative vaccination was common practice as only one farmer did not vaccinate any of his cattle (n = 48). The provision of supplements seemed to be general practice (100%, n = 48) in the district as all the farmers gave some form of supplementation to their cattle. Only 22.9% (n = 11) of the farmers provided supplements according to the production status of the animals and the main reason for not doing so is that 37.8% (n = 14) of the respondents believed that it complicated management and 18.9% (n = 7) thought it not necessary. It is believed that a lack of understanding of the function of supplements by some of the farmers in the district could be the cause of what could be considered as insufficient supplementation by animal nutritionists.

This mixed-method study explored the social world of Haitian migrants, examining forms of social support and social stress, as well as their relationship to mental health. Among six Haitian migrant communities in the Cibao Valley of the Dominican Republic, a community-based survey (n = 127) was conducted to assess migration experiences, current stressors, mental health, and functioning. In addition, to explore perceptions and experiences of migration, social interactions, and mental health, the study drew upon in-depth interviews and free-listing activities among Haitian migrants, as well as cognitive interviews with select survey participants. Depressive, anxiety, and mental distress survey scores were associated with 1) negative social interactions (including interrogation or deportation, perceived mistreatment by Dominicans, and overcrowding) and 2) lack of social support, including migrating alone. Mental distress scores were higher among women, and being married was associated with higher anxiety scores, potentially reflecting unmet social expectations. In qualitative data, participants emphasized a lack of social support, often referred to as tèt ansanm (literally meaning "heads together" in Haitian Creole or Kreyòl and roughly defined as solidarity or reciprocal social collaboration). The authors of the study propose that the practice of tèt ansanm-also termed konbit, and, in the Dominican Republic, convite-could be used as a means of facilitating positive-contact events among Haitians and Dominicans. These interactions could help counteract social stress and build social capital in settings similar to those of the study.

Este estudio de método mixto exploró el mundo social de los migrantes haitianos, mediante el análisis de las formas de apoyo social y el estrés social, así como su relación con la salud mental. Se llevó a cabo una encuesta comunitaria (n = 127) en seis comunidades migratorias haitianas del Valle de Cibao de la República Dominicana para evaluar las experiencias de migración, los factores estresantes actuales, la salud mental y el desempeño. Además, con objeto de explorar las percepciones y las experiencias de migración, las interacciones sociales, y la salud mental, el estudio se basó en entrevistas exhaustivas y actividades de enumeración libre por parte de los migrantes haitianos, así como en entrevistas cognoscitivas dirigidas a algunos participantes seleccionados. Las puntuaciones de la encuesta correspondientes a depresión, ansiedad y aflicción mental se asociaron con 1) las interacciones sociales negativas (incluidos los interrogatorios o la deportación, el tratamiento por parte de los dominicanos percibido como inadecuado, y el hacinamiento) y 2) la falta de apoyo social, incluida la migración en solitario. Las puntuaciones correspondientes a aflicción mental fueron mayores en las mujeres, mientras que la condición de casado se asociaba con puntuaciones mayores de ansiedad, lo que podría reflejar la existencia de expectativas sociales no satisfechas. En cuanto a los datos cualitativos, los participantes recalcaron la falta de apoyo social, a menudo denominado tèt ansanm (que literalmente significa "cabezas juntas" en criollo haitiano o Kreyòl y se define aproximadamente como solidaridad o colaboración social recíproca). Los autores del estudio proponen que la práctica del tèt ansanm (también denominada konbit y, en la República Dominicana, convite) podría usarse como un medio para facilitar los acontecimientos de contacto positivo entre haitianos y dominicanos. Estas interacciones podrían ayudar a contrarrestar el estrés social y promover el capital social en entornos similares a los del estudio.

The importance of containing costs through the optimal utilization of feed emphasizes the need to optimize, rather than maximize, the rate of reproduction. It is, however, unknown which lick supplementation regimen, provided to an extensive beef herd on mixed veld, could bring about the most profitable and efficient farming enterprise. The aim of the study was thus to determine what lick supplementation regime would be most profitable in an extensive beef production system maintained on transitional Cymbopogon-Themeda veld. The different lick supplementation regimens offered differed in crude protein (CP) content, percentage non-degradable protein (NDP), metabolisable energy (ME) content, and recommended daily intake. A herd of Drakensberger cows and heifers was divided into three treatment groups (Treatment A, Treatment B and Treatment C), with 70 animals (n = 70) per treatment group. The CP, NDP, ME content of the licks provided in Treatment A were higher than those provided in Treatment B and C, while the CP, NDP, ME content of the licks provided in Treatment B were higher than those provided to Treatment C, but lower than those provided to Treatment A. The first two years' (2011 - 2012 and 2012 - 2013) preliminary results indicate no significant differences in parameters that affect cow herd performance (weaning weight, cow herd pregnancy rate, intercalving period) between treatments. However, substantial cost differences in the lick supplied between treatments was recorded; thus, affecting profitability. Significant differences between treatments in the pregnancy rates of the first-calf heifers was recorded in the second year, and indicated that providing protein in a drought during summer to first calf heifers may increase the calving rate and hence profitability.

Este artigo descreve a validação de método de cromatografia líquida de alta eficiência em fase reversa (CLAE-RP) com detector de fotodiodos (DAD) para determinação de substâncias relacionadas (impurezas orgânicas de síntese e produtos de degradação) de captopril segundo Farmacopéia Brasileira IV ed. Este estudo teve como objetivo garantir que o método é capaz de quantificar com exatidão o teor de substâncias relacionadas, um requisito essencial para que o teor de captopril seja determinado por balanço de massa no primeiro material de referência certificado (MRC) de fármacos brasileiro, o qual foi desenvolvido pelo Inmetro. A instabilidade do captopril em solução é discutida em detalhes e o teor de captopril determinado por balanço de massa é comparado com aqueles obtidos por titulação e por calorimetria exploratória diferencial (DSC).

This paper describes the validation of a reversed-phase high performance liquid chromatography method (RP-HPLC) with diode array detection (DAD) for determination of related substances (impurities from organic synthesis and degradation products) of captopril according to the Brazilian Pharmacopeia IV. The aim of this study was to guarantee the method accuracy for quantification of related substances, an essential requisite to determine, using the mass balance approach, the captopril content in the first Brazilian certified reference material (CRM) of an active pharmaceutical ingredient (API), developed by Inmetro. The captopril instability in solution is discussed and the captopril content determined by mass balance is compared to the results from titration and differential scanning calorimetry (DSC).

Este artigo descreve os estudos realizados com o candidato a Material de Referência Certificado (MRC) de captopril, primeiro MRC de fármacos no Brasil, incluindo a determinação de impurezas (orgânicas, inorgânicas e voláteis), testes de homogeneidade, testes de estabilidade de curta e longa duração, cálculo do teor de captopril por balanço de massa e estimativa da incerteza de medição associada ao valor certificado.

This paper describes the studies performed with the candidate Certified Reference Material (CRM) of captopril, the first CRM of an active pharmaceutical ingredient (API) in Brazil, including determination of impurities (organic, inorganic and volatiles), homogeneity testing, short- and long-term stability studies, calculation of captopril content using the mass balance approach, and estimation of the associated measurement uncertainty.

Multidisciplinary studies in the Sierra Pinta area in NW Sonora, including U-Pb zircon geochronology, mayor and trace element geochemistry as well as Sm-Nd isotopic studies have allowed a precise characterization of Permian granitic rocks. The results suggest the existence of a suite of Permian granitoids with U-Pb zircon ages between ~275 y ~258 Ma. Initial epsilon Nd values between -19.2 and -10.4 and corresponding Nd model ages (T DM) between 2.5 and 1.6 Ga, as well as some geochemical characteristics, indicate melting of Proterozoic crustal basement associated to the early stages of subduction forming the continental magmatic arc of SW North America. It is likely that this Permian magmatic pulse in NW Sonora was part of a larger event in the American Cordillera extending from western-southwestern USA, passing through northern Mexico and up to central and southern Mexico and, perhaps, to northern South America (i.e., Colombia). We suggest that the occurrence of the Permian granitoids in Sierra Pinta is associated with a Paleoproterozoic crustal weakness zone formed by a narrow stretch of the Yavapai crustal province. This weakness zone could have acted as a channel-way that facilitated the ascent towards higher crustal levels of the first magmas generated by subduction.

Estudios geológicos multidisciplinarios realizados en rocas cartografiadas en el área de Sierra Pinta, en el NW de Sonora, que incluyeron geocronología U-Pb en zircones, estudios isotópicos de Sm-Nd en roca total y geoquímica de elementos mayores, traza y tierras raras, han permitido un precisa caracterización de rocas graníticas pérmicas. Los datos muestran la existencia de rocas pérmicas con edades U-Pb en zircones entre ~275 y ~258 Ma y valores iniciales de épsilon Nd de -19.2 a -10.4 (edades modelo Nd T DM entre 2.5 y 1.6 Ga). Estos datos, junto con los estudios geoquímicos, indican fusión de basamento cortical proterozoico relacionada a los estadios iniciales de la subducción que propició el establecimiento de un arco magmático continental en el SW de Norteamérica. Probablemente este pulso magmático es parte de un gran evento a nivel cordillerano que se extiende desde el SW de los EE. UU. pasando por Sonora, Chihuahua y Coahuila hasta el centro y sur de México, y quizás hasta el norte de Sudamérica (específicamente Colombia). La ocurrencia de estas rocas graníticas pérmicas en la Sierra Pinta podría asociarse a una zona de debilidad cortical formada por una franja angosta de basamento paleoproterozoico Yavapai, como el encontrado en algunos lugares del NW de Sonora, que sirvió para que los primeros magmas generados por subducción ascendieran con mayor facilidad hacia la superficie.

The Zona Canteras-Puerto Peñasco area, previously known as Seven Hills, is located ~20 km ENE of the town of Puerto Peñasco in NW Sonora, Mexico. Crystalline basement in this area is key to defining Proterozoic provinces of SW Laurentia and has important implications for Phanerozoic tectonics and formation of the active continental margin of North America. New U-Pb zircon ages (LA-MC-ICPMS) of two banded gneisses in this area yield 207Pb/206Pb ages at 1764 ± 3 Ma and 1725 ± 3 Ma. Zircons from both samples are well-behaved in the U-Pb systematics and present age and compositional homogeneity, suggesting that these rocks are Paleoproterozoic orthogneisses. These crystallization ages combined with whole rock major- and trace-element geochemistry and Sm-Nd in whole rock and Lu-Hf isotopic determinations on zircons by laser ablation suggest that the banded gneisses have affnities with rocks of the Yavapai province as defned in the Quitovac area ~45 km to the east and in the region of Gunnison-Salida, Colorado, USA. Both samples plot in the volcanic arc environment of granite formation (Y vs Nb discrimination diagram) and have epsilon Hf (initial) values between +1.85 and +5.05 with corresponding single-stage Hf model ages (T DM) at 1.98-2.07 Ga and two-stage Hf model ages (T DM C) at 2.07-2.50 Ga. Sm-Nd whole rock isotopic analyses from three Paleoproterozoic gneisses have epsilon Nd (initial) values between +1.86 and -0.57 with corresponding Nd model ages (T DM) at 1.91-2.02 Ga. The magmatic protoliths of these gneisses could have been formed mostly from mantle sources with some degree of crustal contribution, which is similar to rocks from the Yavapai province in SW North America. This petrogenesis contrasts with typical Mojave-province rocks that are characterized by significantly greater crustal contamination (as much as 30-40% in Death Valley). If these Mojave province rocks exist in NW Sonora they must be located to the west of the Zona Canteras-Puerto Peñasco area.

La Zona Canteras-Puerto Peñasco, conocida anteriormente como Seven Hills, está localizada aproximadamente a 20 km al ENE de Puerto Peñasco en el NW de Sonora, México. El basamento cristalino presente en esta área es clave para definir las provincias proterozoicas del SW de Laurencia y tiene importantes implicaciones para la tectónica Fanerozoica y para la formación del margen continental activo de Norteamérica. Nuevas edades U-Pb en zircones (LA-MC-ICPMS) de dos gneises bandeados de la Zona Canteras- Puerto Peñasco proporcionan edades 207Pb/206Pb de 1764 ± 3 Ma y 1725 ± 3 Ma. Los zircones de ambas muestras están bien preservados y presentan una homogeneidad en composición y edad en cada caso sugiriendo que estas rocas son ortogneises paleoproterozoicos. Estas edades de cristalización combinadas con geoquímica de elementos mayores y traza en roca total y determinaciones isotópicas Sm-Nd en roca total y Lu-Hf en zircones sugieren que los gneises bandeados tienen afinidad con rocas de la provincia Yavapai como las definidas en el área de Quitovac, aproximadamente a 45 km al este del área de estudio y en la región de Gunnison-Salida en Colorado, EUA. Ambas muestras caen en el campo de ambiente de arco volcánico de formación de granitos (diagrama de discriminación Y vs Nb) y tienen valores de épsilon Hf inicial entre +1.85 y +5.05 con correspondientes edades modelo Hf (T DM) en un paso ("single-stage model ages") de 1.98-2.07 Ga y edades modelo Hf (T DM C) en dos pasos ("two-stage model ages") de 2.07-2.50 Ga. Análisis isotópicos de Sm-Nd en roca total de tres gneises paleoproterozoicos presentan valores iniciales de épsilon Nd entre +1.86 y -0.57 y edades modelo Nd (T DM) de 1.91-2.02 Ga. Concluimos que los protolitos ígneos de estos gneises de la Zona Canteras- Puerto Peñasco pudieron haber sido formados por fuentes mantélicas con algún grado de contribución cortical, similar a las rocas de la provincia Yavapai en el SW de Norteamérica. Esto contrasta con la petrogénesis de las rocas típicas de la provincia Mojave, caracterizadas por una gran contaminación cortical (hasta valores de 30-40% en Death Valley) e implicaría que de existir rocas tipo Mojave en el NW de Sonora, éstas deberían de encontrarse al oeste de la Zona Canteras-Puerto Peñasco.

OBJECTIVES: To assess the burden of malaria in San Esteban, Department of Olancho, Honduras, and provide recommendations for control. METHODS: Malaria causes appreciable morbidity in San Esteban. In 2006, health workers reported an increase in malaria cases and requested recommendations for control. In 2005, 385 cases (Plasmodium vivax, 316; P. falciparum, 69) were detected from 4 007 blood smears in the San Esteban laboratory (slide positivity rate = 9.6%). During May-July 2006, we assessed the burden of malaria and made recommendations. We reviewed epidemiologic data from slide-confirmed malaria cases in 2005 and 2006 and conducted a knowledge, attitudes, and practices survey in households to assess malaria diagnostic, treatment, and prevention practices. RESULTS: During May-July 2006, 143 laboratory-confirmed malaria cases were detected (P. vivax, 134; P. falciparum, 9) in San Esteban, compared with 104 (P. vivax, 79; P. falciparum, 25) in May-July 2005. From January 2005 to July 2006, 538 cases were detected in San Esteban, with increased frequency in May-October and the highest incidence in children 0-14 years old. We administered 112 surveys in 19 communities. Seventy percent of respondents reported a history of malaria in a household member, with the highest frequency reported in mothers (45%) and children under 14 years old (37%). Most households did not have mosquito protection such as bed nets, screens, or indoor residual insecticide. CONCLUSIONS: Malaria is ongoing in San Esteban, with increased incidence in children. We recommend increased availability and promotion of insecticide-treated bed nets, improved timing and coverage of indoor residual spraying, and improved community malaria practices through education sessions.

OBJETIVOS: Evaluar la carga de malaria en San Esteban, departamento de Olancho, Honduras, y ofrecer recomendaciones para su control. MÉTODOS: La malaria es causa de una considerable morbilidad en San Esteban. En 2006, los trabajadores sanitarios informaron un aumento de casos de malaria y solicitaron recomendaciones para su control. En 2005, en el laboratorio de San Esteban se detectaron 385 casos (316 por Plasmodium vivax y 69 por P. falciparum) en 4 007 frotis sanguíneos (tasa de positividad: 9,6%). Entre mayo y julio de 2006 se evaluó la carga de malaria y se hicieron las recomendaciones. Se revisaron los datos epidemiológicos de los casos confirmados de 2005 y 2006 y se aplicó una encuesta sobre conocimientos, actitudes y hábitos en los hogares para evaluar las prácticas relacionadas con el diagnóstico, el tratamiento y la prevención de la malaria. RESULTADOS: Entre mayo y julio de 2006 en San Esteban se detectaron 143 casos de malaria confirmados por el laboratorio (134 por P. vivax y 9 por P. falciparum), en comparación con 104 (79 por P. vivax y 25 por P. falciparum) entre mayo y julio de 2005. Entre enero de 2005 y julio de 2006 se detectaron 538 casos en San Esteban, con un aumento en la frecuencia entre mayo y octubre y la mayor incidencia en niños de 0 a 14 años. Se aplicaron 112 encuestas en 19 comunidades. De los que respondieron, 70% había tenido algún miembro del hogar con malaria, con una mayor frecuencia en las madres (45%) y los menores de 14 años (37%). La mayoría de los hogares carecían de protección contra los mosquitos, como mosquiteros para las camas y ventanas o fumigación de interiores. CONCLUSIONES: La malaria se mantiene en aumento en San Esteban, con una mayor incidencia en los niños. Se recomienda incrementar la disponibilidad y la promoción de mosquiteros tratados con insecticidas, mejorar la periodicidad y la cobertura de la fumigación de interiores y mejorar los hábitos de la comunidad mediante sesiones educativas.

Nucleotide sequences of the internal transcribed spacer 2 (ITS2) rDNA and partial sequences of the cytochrome coxidase subunit I (COI) mtDNA and white gene nDNA were obtained from specimens of Anopheles nuneztovari A collected in Macapá (state of Amapá), Óbidos, Prainha and Almeirim (state of Pará), Itacoatiara and Parintins (state of Amazonas), Brazil, and compared with previously published sequences of A. nuneztovari s.l. Results of the Bayesian phylogenetic analyses performed using either COI or combined ITS2, COI and white gene sequences suggest that An. nuneztovari B/C is distinct from specimens obtained in the Amazonas/Solimões River basin. Anopheles goeldii, currently in synonymy with An. nuneztovari, was described from individuals collected in Belterra (= Fordlândia) in the Tapajós River, state of Pará, Southern Amazonas River. Morphological comparisons of the characteristics of the male genitalia indicated that An. nuneztovari A and An. goeldii are similar but distinct from An. nuneztovariB/C by the apex of the aedeagus. In considering the results of the phylogenetic analyses and morphological comparisons, An. goeldii is resurrected from synonymy with An. nuneztovari. Additionally, Anopheles dunhamiis reported for the first time in Parintins. This species can be distinguished from An. goeldiiby characters of the male genitalia and molecular data.

This paper summarizes a behavioural safety project undertaken in seven quarries in the UK in order to investigate its applicability as a means of raising the standards of health and safety in the UK quarrying industry. A behavioural safety methodology was developed and trialed at two quarry sites in the UK. During the study the number of unsafe acts and minor accidents had decreased and at one of the quarries there was a 95% reduction in the number of working days lost. It was then introduced at a further five sites of varying sizes and within this focused specifically on lone workers as well as behaviours that affected quality and environmental issues. Positive improvements were noted in most of these operations. The project also looked at the effectiveness of health and safety performance indicators. Here, the common lead and trailing indicators for both safety and health that are commonly used by industry were identified. In consultation with the UK quarrying industry these were then used to identify specific performance measurement criteria that can be used by the quarrying sector to measure performance. Following on from this, a quarry specific health and safety management system specification was developed for large and small quarries

ABSTRACT A limiting factor in solar stills for the production of purified water is the precipitation of salts in the still basin. The objective of this work was the study of isothermic precipita tion of CaCO3 in a experimental solar still using groundwater as water supply with high concentrations of soluble calcium and sulfates. Three experiments of calcium and bicarbonates reaction were performed. The first experiment was followed during 5 hours with incrustations free still, the second, during 9 hours with incrustations and the third experiment in a 8 hours period with 72 hours of previous contact between the solution and the precipitate. During the first two hours in the three experiments, 71.70, 273.00 and 400.70 mg of CaCO3 were formed respectively. In the precipitate was found calcite as only crystalline phase.

RESUMEN Un factor limitante para la obtención de agua purificada en destiladores solares es la precipitación de sales en la base del evaporador. El objetivo de este trabajo es el estudio isotérmico a 60 oC de la precipitación de CaCO3 en un destilador solar experimental, utilizando como afluente agua subterránea con alto contenido de calcio, bicarbonatos y sulfatos solubles. Se efectuaron tres experimentos de la reacción entre el calcio con los iones bicarbonato. El primer experimento se siguió durante 5 horas con el destilador libre de incrustaciones; el segundo durante 9 horas con incrustaciones y el tercero por un periodo de 8 horas con un tiempo previo de 72 horas de contacto entre el precipitado y la solución. Durante las dos primeras horas en los tres experimentos se precipitaron 71.7, 253.0 y 400.7 mg de CaCO3 respectivamente. En el precipitado se encontró calcita como única fase cristalina.

Agricultural activity in the Andean foothills, VIII Region, due to economic and political changes, has reduced the surface area cultivated and the number of crops, and has damaged the soil and affected the development of rural sectors. One possible change that might be of economic benefit is to rely to a greater extent on crop rotations. The cultural rotations previously proposed for the region were quantified and analyzed economically, based on a nominal annual valuation, and corrected to real values, which included expected margin and the risk associated or variability of that income. Information was used from a long-term experiment of dry-land crop rotations of the Quilamapu Regional Research Center of the Instituto de Investigaciones Agropecuarias (INIA). The average gross margin per hectare varied between $160.000 ha-1 in the wheat-rape-oats-lentils rotation (R5) to $250.000 ha-1 in the wheat-oat rotation (R1). R5 also registered the greatest coefficient of variation, and as such appears to be the least recommendable rotation. Wheat-sowed pasture (3 years) (R4) registered a margin of $230.000 ha-1 and the lowest coefficient of variation (0.27). Rotations with natural fertilized pasture have intermediate economic behavior. The complementary analysis by crop sequences derived from each rotation suggests that there is no crop that is especially recommendable to begin each rotation cycle.

En la agricultura de la Precordillera Andina de la VIII Región, por razones económicas y de política agrícola, se ha reducido la superficie cultivada y la diversidad de rubros, se ha deteriorado el suelo y afectado el desarrollo de sectores rurales. Su aptitud hace factible incorporar rotaciones de cultivos como base de planificación predial. Por ello se cuantificaron y analizaron económicamente rotaciones culturales previamente propuestas para la zona, en base a valorización nominal anual, corrección a valores reales, generación de riqueza (margen) y determinaciones de indicadores de dispersión (riesgo) del beneficio económico. Se utilizó información de un experimento de largo plazo de rotaciones de secano del Centro Regional de Investigación Quilamapu del Instituto de Investigaciones Agropecuaria (INIA). El margen bruto real promedio por hectárea de rotación varió de $160.000 ha-1 en la rotación trigo-raps-avena-lenteja (R5) a $250.000 ha-1 con la rotación trigo-avena (R1). R5 además registró el mayor coeficiente de variación, por tanto pareciera ser la rotación menos recomendable. Trigo-pradera sembrada (3 años) (R4), alcanzó margen de $230.000 ha-1 y el menor coeficiente de variación (0,27). Alternativas con ganadería a base de pradera natural fertilizada tienen un comportamiento económico intermedio. El análisis complementario por secuencias de cultivo derivadas de cada rotación sugiere que no existe un cultivo especialmente recomendable para iniciar el ciclo de cada rotación.

Most of the estimated 20 million people who are blind with cataracts live in rural areas of developing countries, where expert surgical resources are scarce. We have studied the use of multiflex open-loop anterior-chamber intraocular lenses (ACIOL) in high-volume low-cost surgery. Between 1992 and 1995, a total of 2000 people attending Lahan Eye Hospital, Nepal, with bilateral cataracts reducing vision to < 6/36 were randomly allocated to receive intracapsular extraction (ICCE) with aphakic spectacles, or ICCE with an ACIOL. We re-examined the cohort (1305/2000, 65%) between November 1996 and April 1997 and report the findings in this article. There were 13 new cases of poor visual outcome (best corrected vision <6/60) arising after one year: 9 in the ACIOL group and 4 in the control group; odds ratio 2.1 (95% confidence interval, 0.59-9.55). The causes of poor outcome were as follows: ACIOL group - retinal detachment (4 cases), cystoid macular oedema (2), epiretinal membrane (1), age-related macular degeneration (1), and late endophthalmitis (1); control group - retinal detachment (2 cases), late endophthalmitis (1), and primary open-angle glaucoma with age-related macular degeneration (1). In rural areas of developing countries, well-manufactured multiflex open-loop ACIOLs can be implanted safely by experienced ophthalmologists after routine ICCE, avoiding the disadvantages of aphakic spectacle correction.

Se estima que hay unos 20 millones de personas con ceguera bilateral por cataratas, la mayoría de las cuales viven en zonas rurales de países en desarrollo, donde escasean los recursos quirúrgicos especializados. Actualmente no se conoce con exactitud la utilidad de la implantación de lentes intraoculares de cámara anterior (LIOCA) en las situaciones en que hay que practicar un elevado número de intervenciones quirúrgicas a bajo costo. El presente estudio se emprendió con objeto de evaluar la seguridad de las LIOCA multiflex de asa abierta. Hemos informado anteriormente de los resultados observados en una cohorte al cabo de un año de la intervención quirúrgica. Ahora informamos aquí de los resultados del posterior seguimiento de esa cohorte. Un total de 2000 personas que acudieron al hospital oftalmológico Lahan, en el sur de Nepal, con cataratas bilaterales que reducían su visión a <6/36 fueron asignados al azar para someterse bien a una extracción intracapsular (EIC) seguida de uso de gafas para afaquia, o bien a EIC con LIOCA en el primer ojo operado. Dichas personas fueron sometidas a seguimiento a las seis semanas y al cabo de un año de la intervención quirúrgica (resultados publicados anteriormente). El reclutamiento para el presente trabajo tuvo lugar entre principios de febrero de 1992 y finales de febrero de 1995. Reexaminamos la cohorte (1305/ 2000, 65%) entre noviembre de 1996 y abril de 1997. Al cabo de un año detectamos 13 nuevos casos de visión precaria (mejor visión corregida < 6/60): 9 en el grupo sometido a implantación de LIOCA, y 4 en el grupo de control): OR = 2,1 (intervalo de confianza del 95%: 0,59-9,55, P = 0,2). Las causas de visión precaria en esos 13 ojos fueron las siguientes: grupo con LIOCA: desprendimiento de retina (4 casos), edema macular cistoide (2), membrana epirretiniana (1), degeneración macular relacionada con la edad (1), y endoftalmitis tardía (1); y en el grupo de control: desprendimiento de retina (2 casos), endoftalmitis tardía (1), y glaucoma primario de ángulo abierto con degeneración macular relacionada con la edad (1). No se observaron casos de descompensación corneal. Se detectaron más ojos con presión intraocular > 30 mmHg en el grupo con LIOCA (5 frente a 1, P = 0,2); en este grupo, 5 ojos presentaban signos de glaucoma secundario, frente a 2 en el grupo de control. Los resultados de este estudio respaldan la idea de que, en las zonas rurales de los países en desarrollo, oftalmólogos experimentados pueden implantar sin riesgos LIOCA multiflex de asa abierta tras la EIC de rutina, evitando así los inconvenientes asociados a las gafas de corrección de la afaquia. Aunque la incidencia de uveítis y de glaucoma secundario es mayor con la LIOCA que con las citadas gafas, la proporción de personas con visión precaria tras la cirugía es similar en los dos casos.

On estime à 20 millions le nombre de personnes atteintes de cécité bilatérale due à la cataracte, qui pour la plupart vivent dans des zones rurales de pays en développement où les ressources chirurgicales sont rares. On connaît encore mal le rôle des implants intraoculaires de chambre antérieure (IIO-CA) dans les situations où un important volume d’interventions chirurgicales à coût modique est nécessaire. La présente étude a en conséquence été réalisée pour évaluer la sécurité des IIO-CA à anse ouverte en Multiflex. Nous avions déjà rapporté nos observations sur une cohorte un an après l’intervention; nous rapportons maintenant les résultats du suivi ultérieur de cette cohorte. Au total, 2000 personnes venues consulter au Lahan Eye Hospital, dans le sud du Népal, pour une cataracte bilatérale ayant réduit leur vision à < 6/36 ont été réparties par tirage au sort dans un groupe traité par extraction intracapsulaire (EIC) et correction de l’aphakie par des lunettes (groupe témoin), ou dans un groupe traité par EIC puis pose d’un IIO-CA dans le premier œil opéré. Ces personnes ont été revues six semaines et un an après l’intervention (résultats déjà rapportés). Le recrutement pour la présente étude a eu lieu entre début février 1992 et fin février 1995. Nous avons réexaminé la cohorte (1305/2000, 65 %) entre novembre 1996 et avril 1997. Treize nouveaux cas de résultats médiocres sur le plan visuel (meilleure vision corrigée < 6/60) sont survenus dans un délai supérieur à un an après l’intervention (9 dans le groupe IIO-CA et 4 dans le groupe témoin) (odds ratio 2,1 ; intervalle de confiance à 95% : 0,59-9,55 ; p = 0,2). Les causes de ces mauvais résultats étaient, dans le groupe IIO-CA : décollement de la rétine (4 cas), œdème maculaire cystoïde (2 cas), membrane épirétinienne (1 cas), dégénérescence maculaire liée à l’âge (1 cas) et endophtalmie tardive (1 cas), et dans le groupe témoin : décollement de la rétine (2 cas), endophtalmie tardive (1 cas) et glaucome primitif à angle ouvert avec dégénérescence maculaire liée à l’âge (1 cas). Aucun cas de décompensation cornéenne n’a été observé. Davantage de patients présentaient une pression intraoculaire > 30 mmHg dans le groupe IIOAC (5 yeux contre 1 ; p = 0,2); dans ce groupe, on comptait cinq yeux atteints de glaucome secondaire contre 2 dans le groupe témoin. Cette étude montre que, dans les zones rurales des pays en développement, des IIO-CA à anse ouverte en Multiplex de fabrication correcte peuvent être posés en toute sécurité par des ophtalmologistes expérimentés après extraction intracapsulaire de routine, ce qui évite l’inconvénient d’une correction de l’aphakie par des lunettes. Bien que l’emploi des IIO-CA soit associé à un taux plus élevé d’uvéite et de glaucome secondaire que l’utilisation de verres correcteurs, la proportion de personnes ayant un résultat médiocre sur le plan visuel après intervention chirurgicale est similaire.