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Saliva samples may be an easier, faster, safer, and cost-saving alternative to NPS samples, and can be self-collected by the patient. Whether SARS-CoV-2 RT-qPCR in saliva is more accurate than in nasopharyngeal swaps (NPS) is uncertain. We evaluated the accuracy of the RT-qPCR in both types of samples, assuming both approaches were imperfect.We assessed the limit of detection (LoD) of RT-qPCR in each type of sample. We collected paired NPS and saliva samples and tested them using the Berlin Protocol to detect SARS-CoV-2 envelope protein (E). We used a Bayesian latent class analysis (BLCA) to estimate the sensitivity and specificity of each test, while accounting for their conditional dependence.The LoD were 10 copies/mL in saliva and 100 copies/mL in NPS. Paired samples of saliva and NPS were collected in 412 participants. Out of 68 infected cases, 14 were positive only in saliva. RT-qPCR sensitivity ranged from 82.7 % (95 % CrI: 54.8, 94.8) in NPS to 84.5 % (50.9, 96.5) in saliva. Corresponding specificities were 99.1 % (95 % CrI: 95.3, 99.8) and 98.4 %(95 % CrI: 92.8, 99.7).SARS-CoV-2 RT-qPCR test in saliva specimens has a similar or better accuracy than RT-qPCR test in NPS. Saliva specimens may be ideal for surveillance in general population, particularly in children, and in healthcare or other personnel in need of serial testing.

This study quantifies the current and future soil water balance in this region and defines what vegetation covers will be the most affected by modifications of water resources. For this, two periods (2050 and 2070) under different climate scenarios (RCP 4.5 and RCP 8.5) were compared to the current hydrological conditions. Results showed that water resources are currently greater in high elevations, where pyrenean oaks and creeping brooms covers are predominant. Lower elevations, occupy by holm oaks and cork oaks covers, presented lower water resources. Future scenarios forecasted that water resources will decrease in all vegetation covers, and some of them, such as holm oaks cover, will undergo a greater decrease in water resources, with a decline of up to 95% in the worst scenario. Efficient management of these spaces will need a comprehensive study of future water resources, so it is key to advance in this topic.

Mediterranean savannahs, “dehesas,” are an agro-silvo-pastoral land use system in the southwest of Iberian Peninsula where the extensive livestock farming is the main land use. This study analyzes the evolution of bare soil in two different farms with an agro-silvo-pastoral system located in Extremadura (Spain). The main objective was to study the relationship between rainfall and land management with the surface of bare soil in the dehesas. Evolution of annual and monthly rainfall in the study areas from 2001 to 2017 was analyzed. The main findings showed that a lack of rainfall during three months combined with an increase in the livestock density had repercussions in the presence of a greater surface of bare soil in the dehesas. The distribution of livestock in specific areas (for example, ponds or feed troughs) limited grass growth and favored the development of permanent livestock paths. Therefore, new trends in regenerative livestock management combined with a sustainable use of the dehesa ecosystem may be a key to lessen this problem.

Introducción: El presente artículo indaga acerca de la posibilidad de regular el contrato de maternidad subrogada desde una perspectiva de la relación laboral que puede existir entre la madre gestante y los padres adoptantes. De manera que se tiene como objetivo de investigación analizar la aplicación del fuero de maternidad en los contratos de maternidad subrogada, así como esbozar la existencia de una relación de carácter laboral. Investigación que se ejecutó mediante una Metodología correlacional, descriptiva y explicativa. Sobre las cuales los principales resultados obtenidos fueron, por una parte, la multiplicidad de relaciones laborales posibles en el contrato de maternidad subrogada y por otra parte el fuero de maternidad, que debe ser aplicado de manera total y parcial, dependiendo de la madre gestante o la madre adoptiva. Finalmente, las principales conclusiones permiten establecer que existen tres formas o modalidades de relación laboral de manera que al no encontrarse una regulación fuerte sobre la materia pueden presentarse vicisitudes en su aplicación futura.

El presente artículo esquematiza los resultados la investigación realizada cuyo objetivo general es analizar el estado actual de la reforma rural integral establecida en el acuerdo final de paz. Estudio que se realiza a partir de los esquemas territoriales del estado multicultural, en específico, de las dimensiones étnicas y afrocolombianas. Por lo tanto, la pregunta problema que se planteo fue: ¿La reforma rural integral establecida en el acuerdo final de paz, cumple con los esquemas de ordenamiento territorial del estado multicultural? Interrogante que abre la posibilidad de discutir la temática específica de la tenencia de tierras en los territorios étnicos y afrocolombianos, al reiterar que la presencia del estado, maximiza la descentralización y reforma el concepto de municipio, entendido este como un conjunto de áreas rurales y urbanas. No obstante, el reto de los pueblos en el escenario del postconflicto, se encuentra limitado por el actual estado de la Reforma Rural Integral que amenaza lo establecido en el acuerdo final de paz.

The Spanish region of Extremadura represents a paradigmatic case within the European Union because above 30% of its territory (41,634 km2) is protected by international, national or regional figures of protection. In addition, many of these protected areas are connected between them through the so-called Armorican Arch of Caceres which crosses the region from SE to NW as if it were a natural corridor of quartzite ridges. The main goal of this study was to identify tourist resources in this natural corridor aimed at the design of tourist routes that can suppose an opportunity of touristic development in this territory characterized by a low population density. For doing that, we have followed these methodological steps: [1] geographical delimitation of the Armorican Arch of Caceres, [2] socio-economic analysis of the municipalities and [3] identification of the natural protected sites crossed by this corridor, [4] compilation of information on fauna and flora as well as geological and cultural aspects, and [5] design of tourist routes. This corridor passes by 52 municipalities, 7 counties, 3 provinces and 2 countries and connects the La Siberia Biosphere Reserve with the Naturtejo Geopark in Portugal passing by the Villuercas, Ibores, Jara Geopark, the Monfrague National Park (also Biosphere Reserve), the Canchos de Ramiro y Ladronera Special Protection Area for Birds and the International Tagus River Biosphere Reserve. We have identified 81 remarkable tourist resources: 37 natural protected sites, 30 sites of geological interest and 14 medieval castles as well as the presence of fossils and valuable species of flora and fauna (some of them are endangered). By using this information we have designed three thematic tourist routes: birdwatching, medieval castles and geological sites.

Reservoirs play a fundamental role in the hydrological planning of the central valley of Chile as they provide water for human and animal consumption, energy generation, and crop irrigation, especially during the summer season. In agriculture, reservoirs represent a significant source to keep the food security standard for more than half of the population of the country. The water management plans need complete records of their volume to calculate rules of operation or future scenarios; however, currently, these time series include gaps that do not allow better analysis, which increases uncertainty. To address this, the authors test a methodology to assess Sentinel 2 imagery through normalized difference water index (NDWI). The results correctly represent the temporality and seasonality of reservoir dynamics; however, the magnitude of the changes is not well represented when the reservoir is delivering water. This research allows more data-based planning of water resources in the central zone, contributing to better decision-making and more efficient water management.

Extreme precipitation has not only detrimental effects on ecosystems and social and economic sectors, but it is a natural hazard that can trigger floods or soil erosion. This study tries to analyze the extreme rainfalls on different geomorphological units and geographical regions of Chile. For this, data from 87 meteorological stations latitudinally and altitudinally distributed and covering a long period (1980–2018) were used. Results showed that precipitation concentration displays an exponential curve where 30% of the rainiest days were concentrated in only 10% of days with precipitation, proving high irregularity. The decisive weight on annual precipitation falls on a few rainy days with very high rainfall amounts. For return periods > 100 years, extreme events of daily precipitation could reach 109 mm and 305 mm in Northern and Southern Andes Mountains, respectively, while in Northern and Southern Central Depression, their values could be 70 mm and 170 mm, respectively.

Las regiones áridas y semiáridas cubren actualmente más del 45% de la superficie terrestre. El territorio central de Chile se encuentra entre estas zonas y constituye un espacio que debe ser conservado por su importancia económica, ecológica y climática. Sin embargo, la creciente presión sobre el agua y las modificaciones climáticas hacen necesario cuantificar la cantidad de recursos hídricos, tanto actuales como futuros, distribuidos por el territorio chileno y establecer qué biomas podrían verse más afectados por las variaciones hídricas. Este estudio cuantifica el balance hídrico actual y futuro de forma distribuida para todo el territorio chileno y establece qué formaciones vegetales mediterráneas serán las más afectadas por las variaciones de los recursos hídricos. Los resultados demuestran que la zona central, lugar donde se concentra la mayor parte de la población chilena, constituiría uno de los territorios más sensibles a la escasez hídrica, con reducciones de los recursos que alcanzan un promedio de 75 mm año-1 para el 80% de los espacios mediterráneos. El descenso de los recursos hídricos podría comprometer el funcionamiento ambiental y económico de los espacios mediterráneos de Chile.

Chestnut cultivation is a type of traditional centennial exploitation in southern areas of Extremadura. Currently, chestnut is in danger of extinction due to the effects of climate change, some diseases (e.g. Cryphonectria parasitica) and land mismanagement. The high temporal variability of rainfall leads to soil erosion in chestnut cultivation. New forms of management are proposed to try, among other things, to reduce soil losses. This study quantifies soil losses in areas under tree canopies and open areas considering two different age plantations; 1990s and 1960s. To achieve the proposed goal 18 erosion plots were installed as paired plots under tree canopies and open areas in both plantations. The total amount of rainfall per event, tree cover, bare soil, runoff coefficient and sediment concentration were also measured in every plot. The results showed that the highest percentage of bare soil (> 45%) coincides with the period of greatest tree cover (> 75%). The open areas and the youngest plantation showed soil losses higher than the areas under the tree and the oldest plantation. In addition, soil losses increase as higher percentages of bare soil are recorded. We conclude that the size of the trees and a better soil stability in older plantations help reduce soil losses.

Los conceptos de imaginacion e imaginarios han estado presentes en las ciencias geograficas desde hace varias decadas. Estas nociones han permitido crear percepciones y conceptualiza- ciones de los espacios acordes con los contextos en que se desarrollan, considerando enfoques artisticos, literarios, arquitectonicos o sociales. Por ejemplo, siguiendo este ultimo, destacados geografos, como Harvey, conceden a la a la imaginacion geografica un papel politico relevante, no solo para sopesar sobre el papel de las ideas del tiempo y del espacio en diferentes marcos temporales, sino para reflexionar sobre como pretendemos establecer dichas ideas en una socie dad socialista ecologicamente responsable. Por ello, este numero 75 de Revista de Geografia Nor te Grande pretende destacar la importancia de los imaginarios geograficos, ya que, mediante sus diferentes enfoques, realizan novedosas aportaciones que pueden ser aplicadas para entender el territorio de forma integral y, de esta forma, conseguir una gestion optima del mismo.

This study quantifies the current and future soil water balance in a spatially distributed way for the whole of Chile and establishes what biomes will be the most affected by variations in water resources. The study of water resources reveals that 90% of surface Chile will reduce its soil water resources in the future if greenhouse gas concentration in the atmosphere does not stop. The most disadvantaged biomes are the forests, where soil water availability could decrease an average of 100 mm/year. Desert biomes could not perceive the hydrological imbalances; however, it is expected its surface increases.

In the last decades there has been a strong increase around the world in the use of plastic greenhouses (PGs). The Valparaíso region, in the central valley of Chile, has not been the exception, and the area covered by greenhouses has also experienced an increase over the years, reaching 1180 ha in 2007. Taking into account that agriculture in this region employs more than 60,000 people and accounts for 4% of the regional GDP, this information should be available to be included in territorial planning and incorporated into hydrological, economic, and food security models. To do this, the authors propose a new method for identifying the surface covered by PGs based on the intersection of the normalized difference indices and the areas excluded by the masks. The results showed that this methodology was able to identify with a general precision of 86.25% which allowed to classify 1409.85 ha. This area is consistent with the agricultural census carried out in 2007 and with the increase of more than 900 subsidies granted by the government for the installation of new structures.

El presente artículo esquematiza los resultados de investigación, teniendo como objetivo general determinar el papel de la jurisprudencia de la Corte Constitucional en el desarrollo del pluralismo jurídico y el estado multicultural de los pueblos indígenas, el cual se realizó con base en los métodos analíticos, hermenéutico, y descriptivo, planteándose como una investigación de carácter jurídico y cualitativo, con base en la búsqueda bibliográfica y jurisprudencial. Del análisis de 22 sentencias de la Corte Constitucional se pudo obtener como resultado el análisis crítico del papel reglamentario y proteccionista que tiene el alto tribunal, al garantizar derechos y principios a la comunidad indígena. Finalmente, como conclusión se pudo indicar que los grupos indígenas están salvaguardados por la jurisprudencia, pero que, respecto al legislador, posee vacíos de incertidumbre respecto a sus derechos territoriales y de autonomía.

During the last decades, there has been a strong increase around the globe in the use of plastic greenhouses (PGs) which respond to the need to provide better water security, overcome adverse weather events, or elude pests. The central valley of Chile has not been an exception and the surface covered by greenhouses has also experienced an increase over the years. In the Valparaiso region, the surface increased from 1122 ha to 1180 ha throughout the decade 1997-2007. However, on one hand, there has not been a new PGs census since 2007 and, on the other hand, its spatial distribution has not ever been mapped. Considering that agriculture in this region employs more than 60000 people and moves 4% of regional GPD, this information should be available to be included in land planning and to be incorporated into hydrological, economic, and food security models. To overcome this, we propose a new method for monitoring the variations of the surface covered by PGs based on the intersection of normalized difference indexes and areas excludes by masks. For this, free Landsat 8 multi-temporal cloud-free images were used, from which five indexes were obtained (Modified Soil-adjusted Vegetation Index, Temperature Brightness Index, Normalized Difference Vegetation Index - Green, Normalized Difference Built-up Index, and Plastic Surface Index). These indexes were then reclassified in binary form and added up. Finally, urban areas and high slope zones were excluded to obtain the final output. This procedure was run in Google Earth Engine, which allowed easy replication and automation for longer time series or in other study sites. Results proved this methodology was able to successfully discriminate the 86% of PG, which suppose 1410 ha. This surface is consistent with the agricultural census developed in 2007 and with the increase of more than 900 subsidies granted by the government for installing PGs. Its performance also supports our confidence to discriminate PGs in areas with different land covers such as reservoirs, rural areas, open crops, bare soil, and roads. Future studies will allow us to estimate the surface of plastic greenhouses in Chile, mapping its spatial distribution in all the country, and monitor changes over time.

Navezuelas is a good example of the rural area from Inner Spain that is experiencing serious problems of depopulation (862 inhabitants in 1990 vs. 637 inhabitants in 2019) although its land surface covered by fruit trees has increased twofold since the year 2000 (from 475 ha to 886 ha). So, the authors have analyzed data from Corine Land Cover (CLC) and Official Agrarian Censuses and interviewed key agents to understand what is behind this “illogical” cause-effect relationship. The results have shown a reduction in the number of farms below 20 ha in size. Also, the number of farmers has been drastically reduced, particularly in the intervals under 34 years old and between 35 and 54. Finally, the amount of hectares utilized for agriculture has increased both by property as land tenure and by share-cropping. Some of the possible reasons for these figures given by the experts have been the mechanization within the farms and a good tendency in the price of chestnuts since it is the main fruit collected in the municipality.

RESUMEN: Los ecosistemas semiáridos mediterráneos de Chile soportan altas tasas demográficas y mantienen importantes economías asociadas a la productividad del medio natural, sin embargo, dependen fuertemente de la disponibilidad hídrica del medio. A pesar de ello, los estudios desarrollados en ambientes limitados por el agua abordados desde un enfo que ecohidrológico son todavía muy escasos en la zona semiárida de Chile. Este estudio intenta definir el papel del agua sobre el crecimiento de la biomasa herbácea utilizando una combinación de instrumentos que permitieron monitorizar con gran resolución tem poral la dinámica vegetal y distintas variables asociadas al ciclo hidrológico. Los resul tados mostraron que entre el 57% y el 93% de la varianza en la dinámica vegetal puede ser explicada utilizando únicamente tres variables asociadas al ciclo hidrológico (preci pitación, evapotranspiración y contenido hídrico del suelo). De este modo, un cambio en dicho ciclo podría amenazar el mantenimiento y productividad de estos ecosistemas. ABSTRACT: The semi-arid Mediterranean ecosystems of Chile sustain high demographic rates and maintain very important economies related to the environmental productivity, although they strongly depend on water availability. Nevertheless, studies carried out on wa ter-limited environments and from an ecohydrological framework, are very scarce in the semi-arid areas of Chile. This study tries to define the role of water on herbaceous bio mass growth using equipment which monitored some key variables concerning to the water cycle and biomass dynamics with a high temporal resolution. Results showed that between 57% and 93% of total variance in biomass dynamics could be explained using only three variables related to hydrological cycle, such as rainfall, evapotranspiration and soil water content. We concluded that a change in the water cycle of these areas could threat the productivity and maintenance of these ecosystems.

PUFA might modulate inflammatory responses involved in the development of severe dengue. We aimed to examine whether serum PUFA concentrations in patients diagnosed with dengue fever (DF) were related to the risk of progression to dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). A secondary aim was to assess correlations between fatty acids (FA) and inflammatory biomarkers in patients with DF. We conducted a prospective case–control study nested within a cohort of patients who were diagnosed with DF and followed during the acute episode. We compared the distribution of individual FA (% of total FA) at onset of fever between 109 cases who progressed to DHF/DSS and 235 DF non-progressing controls using unconditional logistic regression. We estimated correlations between baseline FA and cytokine concentrations and compared FA concentrations between the acute episode and >1 year post-convalescence in a subgroup. DHA was positively related to progression to DHF/DSS (multivariable adjusted OR (AOR) for DHA in quintile 5v. 1=5·34, 95 % CI 2·03, 14·1;Ptrend=0·007). Dihomo-γ-linolenic acid (DGLA) was inversely associated with progression (AOR for quintile 5v. 1=0·30, 95 % CI 0·13, 0·69;Ptrend=0·007). Pentadecanoic acid concentrations were inversely related to DHF/DSS. Correlations of PUFA with cytokines at baseline were low. PUFA were lower during the acute episode than in a disease-free period. In conclusion, serum DHA in patients with DF predicts higher odds of progression to DHF/DSS whereas DGLA and pentadecanoic acid predict lower odds.

Hydrological processes were investigated since the year 2000 in a semiarid rangeland with disperse cover of evergreen holm oaks. In this article results are presented on the spatial variation of rainfall in the catchment using a network of 6 raingauges. Results are also presented on soil water dynamics, which were studied under different vegetation covers and varying soil depths. Furthermore, the temporal variation of runoff generation in the basin outlet is reviewed, taking into account different timescales. The following results can be highlighted: Spatial variation of rainfall in the catchment at annual or monthly scale was low. However, large dispersion exists in the case of individual rainstorms, when the differences between the 6 raingauges varied strongly, both for daily values as well as maximum intensities. Events with high spatial variation are presumably related with small, localized storms, particularly those of high intensity and short duration, and those showing low variation are probably of frontal origin. Soil moisture presented seasonal patterns clearly dependent on factors such as rainfall or evapotranspirative demand. Spatial distribution of soil moisture was mainly affected by physiographic terrain characteristics and vegetation covers. Generally, in dry hydrological years, soil moisture was lower beneath than beyond the tree canopies, while the opposite was observed in wet years. Dry situations increase the intensity and duration of soil water deficits, enhance the evaporative demand and increment water storage capacity by covers. Channel flow in dehesas depends highly on the antecedent moisture conditions and particularly on the water content of the sediment-filled valley bottoms. If these areas become saturated, high amounts of runoff are produced during rainfall events. Under high intensity rainstorms Hortonian overland flow is rapidly generated on hillslopes producing a quick channel response. Interannual runoff variation is very high, the more frequent low rainfall years provoke very low total water flow, contrasting with less frequent years of above average rainfall, which are the ones producing high total runoff. It can be concluded that the hydrological dynamics in Mediterranean rangelands with a disperse tree cover are complex, both regarding soil water and catchment runoff, being highly variable in time. Future changes in land use or climate could affect notably the hydrological dynamics of the catchment, and hence similar upland basins. For example, a notable increase of tree cover would reduce water availability of pasture plants, particularly during dry years. A decrease of annual rainfall amounts and/or increased drought intensities, as a consequence of climate change, would enlarge periods of soil moisture deficit for pasture plants, as well as a reduction of runoff.

Rangelands in SW Spain constitute the most extensive ranching system on the Iberian Peninsula. During the last few decades, a significant increase in livestock numbers, along with a progressive substitution of cattle for sheep, have led to land degradation processes such as the reduction of grass cover and increased soil compaction in heavily grazed areas. Nevertheless, a better understanding of how soil compaction affects grass production is still needed. In this study, some of the effects of soil compaction due to heavy grazing are analysed, mainly the reduction of the frequency of herbaceous roots and its relationships with bulk density and soil penetration resistance. The study was carried out in 22 fenced areas grazed under different intensities (animal stocking rates: 0.19-15.76 AU ha−1). Undisturbed soil core and bulk samples were collected at 3 depth intervals in order to determine select soil properties (texture, organic matter content, and bulk density). Additionally, soil penetration resistance was quantified at 890 random points at different depths and soil moisture contents. Frequency of herbaceous roots was estimated for each soil horizon in 47 soil profiles and categorized into 4 classes: none, few, common and many. Results showed negative relationships between bulk density (> 10 cm depth) and the content of soil organic matter from 0 to 5 cm (r =−0.061, p < 0.05) and 5-10 m depth (r = −0.824, p < 0.005). Furthermore, a tendency for decreasing mean values of soil penetration resistance as the frequency of herbaceous roots increased was also observed. The values observed confirm that soil compaction provoked by an excessive number of animals reduced the quantity of herbaceous roots. The value of 2 MPa traditionally accepted as restrictive for root growth is discussed. Findings presented here could be of interest for policy makers and farm owners to guide decisions about optimum animal stocking rates.

Spanish rangelands are considered to be of high nature value and a habitat of interest in the European Union due to their productivity and species diversity. However, they are fragile landscapes where farmers’ decisions, such as changes in livestock pressure, can lead to serious deterioration. Currently, no indicator system is being used in these areas to enable farmers to evaluate the condition of rangeland soils. Aiming at this, soil properties, land degradation processes, rainfall characteristics, as well as pasture and land management were analysed in order to propose a set of soil quality and degradation indicators. The study was carried out on 22 enclosures selected from 10 privately-owned farms distributed throughout the Spanish region of Extremadura. Cation exchange capacity, available potassium, soil organic matter, water content at field capacity, soil depth and the thickness of the Ah-horizon were selected as soil quality indicators, with the percentage of bare ground cover and bulk density measured from 5 to 10 cm in depth selected as soil degradation indicators. All the indicators were classified into 5 categories and land units were assessed accordingly. The results revealed that 14% of cases showed very low soil quality and 18% high degradation. The reasons that motivated the selection and categorisation of each indicator are described and the proposed system is compared with other existing indicator systems.

The drawing of maps of soil quality at a large scale is increasingly being more useful to land planners and stakeholders. Nevertheless, it involves different methodological steps from the description of soil profiles in the field until the regional mapping of integrative soil quality index (IQI) values. The development of proper scoring functions is a paramount task for the calculation of these IQI values since every parameter needs to be standardized accordingly and weighting factors are usually estimated by multivariate techniques. The main goal of this study was to map soil quality in the Spanish region of Extremadura (commonly known by its rangelands called dehesas). To do that, i) we gathered information from 194 soil profiles described throughout the region, ii) we calculated the weighting factors of ten meaningful parameters used as indicators by using multivariate techniques (Principal Component Analysis, PCA; and Analytic Hierarchy Process, AHP), and iii) we developed standard scoring functions (SSFs) that represent the singularity of every variable (less is better, more is better). We established upper and lower limits for standardizing the values of each indicator properly. Regarding weighting factors, soil texture was highlighted by the PCA and nutrients by the AHP. Once IQI values were calculated, two regional maps of soil quality were drawn by using interpolation methods (ordinary kriging). The IQI maps showed remarkable spatial differences in soil quality presumably induced by land management. We conclude this methodology could be useful and we encourage other colleagues to test its effectiveness in places where soil data are available.

Background: Use of RT-qPCR pool testing in the diagnosis of SARS-CoV-2 infection has been limited due to a lack of data on its sensitivity and efficiency. Methods: We mixed single specimens of extracted RNA positive for the SARS-CoV-2 E gene by RT-qPCR with negative specimens, in pools of 4 (n=89), 8 (n=92), 16 (n=102), and 32 (n=105) specimens each. We estimated the average change in Ct for each pool size and added it to the Ct values of the first 1,350 tests in our lab, to obtain dilution-corrected Ct values. We estimated pool sensitivity as the proportion of samples with dilution-corrected Ct>40, and used it in simulations of the efficiency (tests used/true case detected) of binary split pool testing. Findings: We tested 388 pools. Average Ct changes were 2.21, 2.51, 3.27, and 3.94 cycles, for pools of 4, 8, 16, and 32 specimens, respectively. Corresponding pool tests sensitivities were 91.1%, 89.6%, 85.8% and 82.5%. Pool testing was substantially more efficient than individual testing. For prevalence of 0.5% to 2.0%, the efficiency of pools of ≥8 specimens was 30% to 280% higher, and the number of people tested was 4.4 to 13.9 times higher than those of individual testing were. Interpretation: Binary split pool testing substantially increases the number of people tested and the number of true cases detected per test. This strategy is key to curtail the transmission of SAR-CoV-2, by increasing efficiency in the identification and isolation of symptomatic and asymptomatic infected individuals. Funding: Major Office of Bucaramanga, Colombia. Declaration of Interests: None. Ethics Approval Statement: The study was approved by both the UIS’ and the University of Wisconsin-Madison’s Institutional Review Boards.

What makes the Lower Segura River (southeast of Spain) unique is the existence of a densely populated and entropized territory around a smallholder agricultural activity that for centuries has shaped the so-called &ldquo, Segura Orchard.&rdquo, In recent years, there has been widespread occupation due to the construction of secondary residences, which has clearly changed the rural appearance, sometimes creating an image more typical of disorderly residential urbanization than of an inhabited agricultural territory. The objective of this paper is to determine the attitude and position of the resident population regarding the situation and future prospects that are envisioned for this area. In this paper, we have conducted a personal and open interview as a technique to collect the information. If we are not capable of generating sustainable socio-economic activity, we will not be able to preserve, protect and transcend what we still know as an orchard. This spatial structure is undoubtedly singular and complex, and after a process of loss of identity and alteration of traditional uses, it requires an intervention that tends to organize it and protect the important territorial heritage that it still preserves.

Soil degradation phenomena, including water erosion and physical and biological processes, have already been reported in rangelands of southwestern Spain. The increasing numbers of livestock since 1986 have been highlighted as one of the key causes. The main goal of this work is to analyse the effects of the excessive number of animals on soil quality and pasture production on privately owned farms dedicated to extensive ranching. Soil properties and surface cover, pasture production, rainfall and land management variables such as livestock density were analysed during a period of 3 years (2008–2011). The study was carried out in 22 livestock enclosures selected from ten farms distributed throughout the Spanish region of Extremadura. The occurrence of bare soil patches and water erosion processes, as well as an increase of mean bulk density in the soil layer from 5 to 10 cm in depth, was observed in the enclosures with animal stocking rates exceeding 1 AU ha−1. Indications that confirm the negative effects of increased bulk density on pasture production and quality were also found. Copyright © 2016 John Wiley & Sons, Ltd.

Population growth, global warming, and increased demand for water have caused global concern about increasing water scarcity. Chile has an unequal geographical distribution of water resources. The north-central area where more than half of the country&rsquo, s population lives has an availability of less than 1000 m3/hab/year. Particularly, the Coquimbo Region has been one of the most affected by drought due to the great agricultural activity in the area. In this study, surveys were carried out in rural schools and households to determine water consumption habits. The results in the schools showed that between 42% and 72% of the wastewater generated comes from the washbasin, which represents light greywater, that is, with low organic matter content. According to the data obtained, the amount of greywater generated on average reached 12 L per capita per day. These waters have the potential to be treated and reused effectively for the flow of toilets or garden irrigation. In the case of households, the generation of greywater was 84% of the total water consumed, of which, more than 86% correspond to light greywater from the shower and washbasin. On average, the light greywater generated daily reached 204 L per person per day. Due to the heterogeneity of drinking water sources in rural areas of the Coquimbo Region, the high rate of greywater generation in both schools and homes indicates the great potential for water treatment and reuse in this area. These results contribute to a better understanding of water consumption habits in rural areas affected by water scarcity and the potential of implementing greywater treatment systems to generate a decrease in demand for drinking water.

Population based serological surveys are the gold-standard to quantify dengue (DENV) transmission. The purpose of this study was to estimate the age-specific seroprevalence and the force of infection of DENV in an endemic area of Colombia. Between July and October 2014, we conducted a household based cross-sectional survey among 1.037 individuals aged 2 to 40 years living in 40 randomly selected locations in urban Piedecuesta, Santander, Colombia. In addition, we also enrolled 246 indviduals living in rural “veredas”. Participants were asked to answer a questionnaire that included demographic, socioeconomic and environmental questions and to provide a 5 ml blood sample. Sera were tested using the IgG indirect ELISA (Panbio) kit to determine past DENV infection. The overall DENV seroprevalence was 70% (95% CI = 67%-71%), but was significantly higher in urban (81%, 95% CI = 78%-83%) as compared to rural (21%, 95% CI = 17%-27%) locations. Age was a major predictor of seropositivity, consistent with endemic circulation of the virus. Using catalytic models we estimated that on average, 12% (95%CI = 11%-13%) of susceptible individuals living in the city are infected by DENV each year. Beyond age, the only predictor of seropositivity in urban locations was prior history of dengue diagnosed by a physician (aPR 1.15, 95% CI = 0.98–1.35). Among participants living in rural settings, those that reported traveling outside of their vereda were more likely to be seropositive (aPR 3.60, 95%CI = 1.54–8.42) as well as those who were born outside of Santander department (aPR = 2.77, 95%CI = 1.20–6.37). These results are consistent with long term endemic circulation of DENV in Piedecuesta, with large heterogeneities between urban and rural areas located just a few kilometers apart. Design of DENV control interventions, including vaccination, will need to consider this fine scale spatial heterogeneity., Author summary Dengue is the most rapidly expanding arbovirus in the world. Counts of reported dengue cases, as usually reported by surveillance systems, are a poor metric of the underlying transmission because most of the infections are asymptomatic. Population based serological surveys, where the prevalence of antibodies to dengue virus are measured in a random sample of the population, are considered the gold-standard to quantify dengue transmission. In this study, the authors conducted a population based serological survey in urban and rural areas of Piedecuesta, Santander, Colombia. Seropositivity was significantly higher in urban as compared to rural locations. Age was a major predictor of seropositivity, consistent with long-term circulation of the virus in this setting. They estimated that, on average, 12% of susceptible individuals living in urban locations get infected by dengue each year. The only predictor of prior dengue infection in urban inhabitants was self-reported history dengue. In rural locations, traveling regularly outside of their “vereda” (neighborhood) and having been born outside of Santander department were associated with seropositivity. These results show that the Piedecuesta municipality is an endemic area of dengue transmission, with large heterogeneities between urban and rural settings. Control interventions, including vaccination should be targeted at fine spatial scales.

Land degradation is becoming a serious concern for the sustainability of traditional agrosilvopastoral systems such as the Brazilian faxinal. The IAP (Environmental Institute of the Federal State of Paran&aacute, ) is favoring the partial exclusion to grazing for 10 years as strategy both to recover degraded lands and to reduce negative effects. Nevertheless, this strategy is being followed by a reduced number of owners (faxinalenses) and little is known about the effectiveness of these measures due to either lack of field data and knowledge on faxinalenses&rsquo, perceptions. We have identified one out of few farms that have followed this official strategy and, within the same farm, we have compared values of some soil properties (bulk density, porosity, water holding capacity, penetration resistance, soil organic matter and root density) from an excluded area to grazing for 10 years, with some areas that represent a gradient of grazing intensity (natural forest, secondary forest, degraded forest, grassland and a degraded area by pigs). In addition, we have interviewed some faxinalenses (one faxinal farm is owned by several farmers) in order to better understand how the risk of land degradation is perceived by them and their opinions about the usefulness of partial grazing exclusion as a strategy to improve the management of their farms. The results have shown that soil quality increases considerably as a consequence of grazing exclusion, in spite of land has been used for cropping yerba mate during the exclusion time, but faxinalenses are not mindful of these benefits and they are no longer interested in excluding other areas of their farms. They think this strategy is simply an obligation imposed by the environmental authority.

Since the end of the last century, Spain has become a country of reference in the European Union due to its volume of bottled mineral water. This study aims to analyze the evolution of the key aspects of this sector over the last two decades. Through this research, it has been verified that (i) Spanish mineral water has been analyzed for a long time from a medicinal and geochemical point of view, and not so much in commercial analysis, (ii) water has great diversity due to the abundance of hydrogeological domains that this country offers, (iii) a very strict legal framework must be complied for its commercialization, (iv) its consumption has been growing, and (v) the business structure is characterized by the predominance of a small group of companies, with a very important role in multinational corporations. Three nature reserves: Montseny, Sierra Nevada, and Guadarrama Mountains, stand out from the rest of the Spanish territory in terms of catchment and packaging of natural mineral water, which is an increasingly strategic resource.

Summary Soil water is recognized as the key factor that controls the organization and functioning of dryland ecosystems. However, in spite of its great importance in ecohydrological processes as well as in modelling applications, most of the studies focus on daily or longer timescales, while its dynamics at shorter timescales are very little known. The main objective of this work was to determine the role of vegetation covers (grassland and tree canopy) in the soil hydrological response using measurements with high temporal resolution in evergreen oak woodland with Mediterranean climate. For this, soil water content was measured with capacitive sensors installed in the soil profile at different depths registering continuously with a high time resolution. Three study areas were monitored for two and half hydrological years. Results obtained revealed that rainwater amounts reaching the soil may temporarily be modified by covers according to precipitation properties and antecedent conditions (from dry to wet) before the rain episode. Rainfall amounts triggering a positive soil hydrological response decreased as initial states became drier, being more accentuated below tree canopies. The frequency of re-wetting cycles and the antecedent states seem to be as important or even more than either the duration or the precipitation amount. Therefore, the role of vegetation was more decisive under drier environmental conditions, where events lower than 6 mm and 2 mm never caused soil hydrological response either below tree canopy or grassland, respectively. This is important because initial conditions were independent of seasonality and because more than half of all rainfall events registered amounts smaller than 5 mm. If changes on precipitation patterns turn out in drier conditions, the predominance of such situations could have important ecohydrological consequences in semiarid ecosystems.

The accuracy of different workflows using Structure-from-Motion and Multi-View-Stereo techniques (SfM-MVS) is tested. Twelve point clouds of the Corral del Veleta rock glacier, in Spain, were produced with two different software packages (123D Catch and Agisoft Photoscan), using Low Dynamic Range images and High Dynamic Range compositions (HDR) for three different years (2011, 2012 and 2014). The accuracy of the resulting point clouds was assessed using benchmark models acquired every year with a Terrestrial Laser Scanner. Three parameters were used to estimate the accuracy of each point cloud: the RMSE, the Cloud-to-Cloud distance (C2C) and the Multiscale-Model-to-Model comparison (M3C2). The M3C2 mean error ranged from 0.084 m (standard deviation of 0.403 m) to 1.451 m (standard deviation of 1.625 m). Agisoft Photoscan overcome 123D Catch, producing more accurate and denser point clouds in 11 out 12 cases, being this work, the first available comparison between both software packages in the literature. No significant improvement was observed using HDR pre-processing. To our knowledge, this is the first time that the geometrical accuracy of 3D models obtained using LDR and HDR compositions are compared. These findings may be of interest for researchers who wish to estimate geomorphic changes using SfM-MVS approaches.

Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatiotemporal variations of pasture production at the decadal–century scales over whole watersheds are poorly known. We used a physically based, spatially distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300-year-long synthetic daily climate data set generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under the current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production but more interannual variability. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long-term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

Interactions between land and atmosphere directly influence hydrometeorological processes and, therefore, the local climate. However, because of heterogeneity of vegetation covers these feedbacks can change over small areas, becoming more complex. This study aims to define how the interactions between soil moisture and vegetation covers influence soil temperatures in very water-limited environments. In order to do that, soil water content and soil temperature were continuously monitored with a frequency of 30 min over two and half hydrological years, using capacitance and temperature sensors that were located in open grasslands and below tree canopies. The study was carried out on three study areas located in drylands of Mediterranean climate. Results highlighted the importance of soil moisture and vegetation cover in modifying soil temperatures. During daytime and with low soil moisture conditions, daily maximum soil temperatures were, on average, 7.1 &deg, C lower below tree canopies than in the air, whereas they were 4.2 &deg, C higher in grasslands than in the air. As soil wetness decreased, soil temperature increased, although this effect was significantly weaker below tree canopies than in grasslands. Both high soil water content and the effect of shading were reflected in a decrease of maximum soil temperatures and of their daily amplitudes. Statistical analysis emphasized the influence of soil temperature on soil water reduction, regardless of vegetation cover. If soil moisture deficits become more frequent due to climate change, variations in soil temperature could increase, affecting hydrometeorological processes and local climate.

Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatio-temporal variations of pasture production at the decadal to century scales over whole watersheds are poorly known. We used a physics-based, spatially-distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300 yr long synthetic daily climate dataset generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

Introduccion. El dengue es la infeccion transmitida por mosquitos mas importante en el mundo. Existe informacion de que las alteraciones bioquimicas pueden utilizarse como herramientas predictoras de gravedad del dengue. Objetivo. Evaluar las alteraciones bioquimicas como posibles marcadores predictores de gravedad del dengue. Materiales y metodos. Se llevo a cabo un estudio de casos y controles anidado en una cohorte. Se seleccionaron al azar 125 casos con dengue grave y 120 controles con dengue no grave para evaluar los niveles sericos de lactato-deshidrogenasa (LDH), creatina cinasa (CK), proteina C reactiva(PCR) y albumina, en sueros obtenidos en las primeras horas de la enfermedad. Para evaluar el valor diagnostico de cada biomarcador, se establecieron puntos de corte con una sensibilidad del 90 % enla deteccion de casos graves. Resultados. Se observo una asociacion entre los niveles de PCR por debajo de 9,8 mg/l (OR=0,04;IC95%=0,02-0,08; p=0,000), de LDH inferiores a 400 U/L (OR=0,49; IC95%=0,24-1,02; p=0,053) y de albumina menor de 4 mg/dl (OR=3,46; IC95%=1,96-6,12; p=0,000), con la gravedad del dengue. En contraste, los niveles de la CK no mostraron asociacion con la gravedad de la enfermedad. Conclusiones. Los hallazgos de nuestro estudio sugieren una asociacion de los niveles de PCR, LDH y albumina con la gravedad del dengue. Estas pruebas bioquimicas podrian ser utilizadas como herramientas predictoras del curso clinico de la infeccion. doi: http://dx.doi.org/ 10.7705/biomedica.v33i0.732

Dengue is the most important mosquito-borne infection in the world. There is evidence supporting the use of biochemical alterations as prediction tools for severity of illness in dengue.To evaluate biochemical alterations as potential prediction markers for severity in dengue.This was a case-control study nested in a cohort. We randomly selected 125 severe dengue cases and 120 controls with non-severe dengue for measuring LDH, CK, CRP and albumin serum levels using acute phase sera. To evaluate the predictive value for each biomarker, we established cut-off points with 90% sensitivity in detecting severe cases.There was association among the CRP levels9.8 mg/L (OR=0.04; 95%CI=0.02-0.08; p=0.000),400 U/L LDH levels (OR=0.49; 95%CI=0.24-1.02; p=0.053) and4 mg/dl albumin levels (OR=3.46; 95%CI=1.96-6.12; p=0.000) with the severity of dengue. In contrast, the CK levels showed no association with the severity of the disease.Our findings suggest an association of CRP, LDH and albumin levels with the severity of dengue. These biochemical tests could be used as predictive tools in the clinical course of the infection.

Las formas del relieve están directamente relacionadas con los procesos ambientales que sobre ellas se desarrollan, como los hidrológicos. Para estudiar estos procesos se utilizan numerosas técnicas, como la instalación de estaciones de medición de la humedad del suelo, las cuales tienen un alto coste, tanto instrumental como asociado a su montaje. A partir de Modelos Digitales del Terreno (MDT) se han realizado una serie de análisis espaciales para obtener clasificaciones geomorfométricas de las formas del relieve. Estas clasificaciones han permitido la delimitación de áreas que pueden diferenciarse por tener una humedad edáfica distinta y por desarrollar procesos hidrológicos diferentes, según el tipo de unidad geomorfométrica que representen. De esta forma se ha facilitado la selección de zonas para la instalación de las estaciones. Los resultados se han corroborado con trabajo de campo. Esta técnica se presenta como una herramienta eficaz para la obtención de la localización potencial de zonas con distinta humedad edáfica según su posición en las áreas de estudio, lo que permite reducir el tiempo y costes asociados al trabajo de campo, y permite delimitar de antemano las áreas óptimas para la instalación de las estaciones. Landforms are directly related to environmental processes that are developed on them, such as hydrology. To study these processes many techniques are used, as installation of monitoring stations for soil moisture, which have a high cost associated with both instrumental and assembly. From Digital Terrain Models (DTM) spatial analyses have been conducted in order to obtain geomorphometric landform classifications. These classifications have allowed the delimitation of areas of different soil moisture content and hydrological processes, according to the type of geomormophetric units. This has facilitated the selection of sites for the installation of soil moisture monitoring stations. Results have been verified by fieldwork. This technique appears as an effective tool for obtaining the potential location of different soil moisture content areas reducing time and economical costs associated with fieldwork and allow defining in advance the optimal areas for soil moisture monitoring installation.