A temporal analysis of the consequences of the drought regime on the water footprint of agriculture in the Guadalupe Valley, Mexico.

Changes in water availability have a substantial impact on the sustainability and maintenance of agriculture, with water footprint (WF) being a robust methodology to assess these transformations. The Guadalupe Valley is one of the places with the highest agricultural production in Mexico. Despite its semi-arid climatic conditions, it provides high-quality crops that are well-positioned in the world. The historical trend of rainfall and temperatures between 1987 and 2017 was analyzed to identify climatic patterns in the territory. Through the calculations of the water footprint of Grapevine and Olive crops, the sensitivity of the crops to recurrent water deficit and their adaptation in their yields to drought episodes was identified. The reduction in precipitation and occurrence of extreme temperatures have contributed significantly towards augmenting crop evapotranspiration and, consequently, intensifying crop irrigation demands. As a result, there has been an apparent increase in the consumption of WFagricultural since 2007. Thus, the period of highest WFagricultural consumption was 2014 (Extremely dry), as opposed to 2011 (Very wet). In particular, the lowest WFgreen consumptions were observed in extremely dry years, that is, > 20% of the WFagricultural intensifying drought events. Therefore, these periods were compensated with higher uses of WFblue and WFgray, which are inversely correlated with precipitation, where vine crops consume 73% more WFagricultural compared to olive plantations, showing greater interannual variability. These results contribute to analyzing the temporal evolution of water consumption for agriculture, providing a basis for rational water use strategies.

A new method to map groundwater-dependent ecosystem zones in semi-arid environments: A case study in Chile.

Groundwater (GW) use has intensified in recent decades, threatening the ecological integrity of groundwater-dependent ecosystems (GDEs). The study of GDEs is limited; therefore, integrated, interdisciplinary environmental approaches that guarantee their monitoring and management amid current climate and anthropogenic changes are needed. A new geospatial method with an integrated and temporal approach was developed through a multicriteria approximation, taking into account expert opinion, remote sensing-GIS, and fieldwork to map groundwater-dependent ecosystem zones (GDEZ). A survey of experts (N = 26) was conducted to assign degrees of importance to the various geospatial parameters, and the mapping was carried out using 14 parameters. The reclassified parameters were normalized on a scale of 1 to 5 according to the degree of probability of the presence of GDE. The validation was carried out through fieldwork and statistical analysis. Then, the spatio-temporal changes amid changing GW levels were assessed using the summer season normalized difference vegetation index (NDVI). Two GDEZ maps were obtained, for 2002 and 2017, between which the high- and very-high-probability zones of GDEs decreased by 31,887 ha (~ 38%). The most sensitive temporal parameters that most influenced the spatio-temporal changes on GDEs were precipitation and land use, with rain exerting a slightly the greatest influence. It was also demonstrated that identified ecosystems decreased in area or were affected by aquifer depletion (NDVI-GW, r Pearson ≥0.74). This validated method allows spatio-temporal changes in GDEs to be mapped and analyzed at an annual scale and is transferable to other arid and semi-arid environments.

Understanding agricultural water footprint variability to improve water management in Chile.

Understanding water consumption is crucial for sustainable management of water resources. Under climate change scenarios that project highly variable water availability, the need for public policies that assure efficiency and equity in water resources is increasing. This work analyzes the case of the Cachapoal River agricultural basin (34°S 71°W), which presents temperature increases and a precipitation deficit, with a drought period that began more than eleven years ago having significantly decreased water availability. Water consumption in the basin for food production was determined from the agricultural water footprint (WFagricultural), using the green (WFgreen), blue (WFblue) and gray water footprint (WFgray) indicators, which were measured in the upper, middle and lower basin under conditions of climate variability (dry, wet and normal years). The greatest WFagricultural was established in the dry year, with a total of 18,221 m3 t-1, followed by 15,902 m3 t-1 in the wet year and 14,091 m3 t-1 in the normal year. Likewise, the greatest WFblue and WFgray, of 12,000 m3 t-1 and 4934 m3 t-1, respectively, were also observed in the dry year. The greatest WFgreen, 2000 m3 t-1, was calculated for a normal year. The 63% of agricultural area of the basin was covered by avocado (Persea americana), olive (Olea europaea), corn (Zea mays) and grape (Vitis sp) crops, which presented the greatest WFagricultural. This water footprint data provides a quantitative basis for the assessment of water consumption and degradation, considering agricultural production and its multiple variables. The success of the application of these results lies in the use of indicators to understand change processes and complement future water allocation plans with more rational water management models.

A new method to evaluate the vulnerability of watersheds facing several stressors: A case study in mediterranean Chile.

Freshwater systems are subjected to multiple anthropogenic stressors and natural disturbances that act as debilitating agents and modifiers of river systems, causing cumulative and synergistic effects that deteriorate their health and result in watershed vulnerability. This study proposes an easy-to-apply spatial method of watershed vulnerability evaluation using Geographic Information Systems (GIS) in the Andalién River watershed, located in the Chilean mediterranean. A watershed vulnerability index (WVI) based on three sub-indices - anthropogenic stressors, environmental fragility and natural disturbances - was developed. To determine the index grouping weights, expert surveys were carried out using the Delphi method. We subsequently normalized and integrated the factors of each sub-index with relative weights. The ranges of each thematic layer were re-classified to establish vulnerability scores. The watershed was divided into three sections: headwaters zone, transfer zone and depositional zone. The watershed vulnerability index showed that 41% of the watershed had very low vulnerability and 42% had medium vulnerability, while only 1% - in the depositional zone - had high vulnerability. A one-way ANOVA was carried out to analyze the vulnerability differences among the three sections of the watershed; it showed significant differences (F (2, 16) = 8.15: p < 0.05). The a posteriori test showed differences between the headwaters and depositional zones (Tukey test, p = 0.005) and between the transfer and depositional zones (Tukey test, p = 0.014). To validate the WVI, water quality was measured at 16 stations in the watershed; there was a significant correlation between vulnerability level and NO2- levels (r = 0.8; p = 0.87; α = 0.05) and pH (r = 0.8; p = 0.80; α = 0.05). The WVI showed the cumulative effects of multiple stressors in the depositional zone of the watershed. This is the first study to evaluate and validate non-regulated watershed vulnerability with GIS using multiple anthropogenic and natural stressors.

Resolución de vólvulos de sigmoides por laparoscopía. Informe de un paciente / Laparoscopia resolution of sigmoid volvulus. Report of one patient

Objetivo. Describir el caso de un paciente con vólvulus de sigmoides resuelto mediante cirugía laparoscópica. Sede. Hospital de tercer nivel de atención. Diseño. Descripción de un caso. Descripción del caso. Se trató de un paciente del sexo masculino de 81 años de edad, con enfermedad de Alzheimer avanzada en quien se hizo el diagnóstico clínico-radiológico de vólvulus de sigmoides, se realizó laparoscopía diagnóstica que confirmó la sospecha de vólvulos de sigmoides. Se realizó colostomía en asa a través de la cual se introdujo un endoscopio con el cual se obtuvo una descompresión total del colon sigmoides. El paciente evolucionó satisfactoriamente y fue dado de alta del hospital al octavo día post-operatorio

Reparación laparoscópica de los defectos herniarios inguino-crurales: propuesta de clasificación (informe preliminar) / Laparoscopic hernia repair

De febrero de 1992 a diciembre de 1994 se intervinieron 138 pacientes con un total de 179 hernias. Se efectuaron diferentes tipos de reparación dependiendo del defecto a tratar; a) ligadura del defecto en el cuello del saco invertido; b) disección peritoneal y sutura del defecto; c) disección peritoneal, sutura del defecto y colocación de malla y d) disección peritoneal y colocación de polipropileno para cubrir la región. Ochenta y tres fueron hombres y 55 mujeres, con edad mínima de 8 años y máxima de 91, promedio 39 años, sin selección de casos. Los tipos de reparación fueron dependiendo de su apariencia endoscópica. Las indirectas con orificio interno menor a un centímetro de diámetro(23) fueron tratadas con cierre del orificio del saco herniario invertido, (19) indirectas con orificio entre 1 y 2 centímetros de diámetro con disección del peritoneo y aproximación con sutura del tracto ileopúbico al arco del transverso, y las indirectas de mas de 2 cm. de diámetro del orificio interno (89), así como las directas de cualquier tamaño (17), hernias de pantalón (15), femorales (2), las que tenían deslizamiento de vísceras (6) y las recidivantes (8) con disección del peritoneo y aproximación con sutura en los casos que era posible hacerlo sin tensión y aplicación de malla. La reintegración normal a las actividades fueantes de una semana en el 90/100 de los casos. La recidiva fue de 1.1/100. Se presentaron 2 casos de meralgia parestésica, tres de hematoma resuelto espontáneamente, y una necrosis de grasa sin recidiva de la hernia, que se reexploró. No se registró mortalidad. De acuerdo a los anteriores resultados clasificamos las hernias con base en su apariencia endoscópica para individualizar el tratamiento y evaluar los resultados a largo plazo en: Tipo Ia, indirectas con orificio interno de menos de 1 cm de diámetro. Ib indirectas con orificio interno entre 1 y 2 cm. de diámetro y Ic indirectas con orificio interno de más de 2 cm. de diámetro. Tipo IIa las directas de cualquier tamaño. IIb las hernias en pantalón, IIc hernias femorales. Tipo III hernias con deslizamiento. Tipo IV recidivantes

Osteotomía distal tipo Reverdin modificado del primer metatarsiano en el tratamiento de hallux valgus / Modified distal osteotomy Reverdin type of the first metatarsal in the treatment of hallux valgus

Se analiza el mecanismo patológico de la deformación del hallux valgus y el efecto mecánico permanente que logra la osteotomía tipo Reverdin sobre la deformación al conseguir el alineamiento del primer metatarsiano y del dedo grueso y conservar la articulación metatarsofalángica en máxima desviación lateral. Se informa de 13 pies operados con la técnica descrita y se analizan los resultados con un seguimiento promedio de 36 meses, con máximo de 96 y mínimo de siete. Todos los enfermos tuvieron una corrección muy satisfactorial. Cuatro de los 13 consiguieron el cierre progresivo del primer espacion intermetatarsiano. El alineamiento metatarsofalángico tuvo un promedio de corrección de 19 grados; el del ángulo cuneo-metatarsiano fue de 5 grados en 12 de los 13 pacientes. El índice de Piggott pasó de tres congruentes antes de la cirugía a ocho después de ella, y de cinco subluxados antes de la cirugía, a uno después de ella. Se confirma la hipótesis de trabajo.