106 research outputs found

    Home Range of Lomas Lizard Microlophus tigris (Sauria: Tropiduridae) in Carabayllo Lomas, Lima - Peru

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    El ámbito de hogar o “home range”, es el área donde un individuo encuentra todos los recursos para su supervivencia, por ende su estudio es fundamental para conocer su ecología y estado de conservación. La lagartija de las Lomas, Microlophus tigris, es una especie endémica de la costa central del Perú, cuyo ámbito de hogar no ha sido estudiado. Para estudiar el uso del espacio de M. tigris se evaluó el ámbito de hogar de 15 individuos (9 machos y 6 hembras) durante la época no reproductiva en las Lomas de Carabayllo, Lima, Perú. Se empleó el método del Mínimo Polígono Convexo para estimar el área del ámbito de hogar. Los machos fueron significativamente más grandes y pesados que las hembras. No obstante, no hubo diferencias significativas entre el ámbito de hogar de los machos y hembras debido a la variabilidad del ámbito de hogar de los machos. El tamaño del ámbito de hogar de las lagartijas evaluadas no estuvo relacionado con su tamaño corporal (Longitud hocico-cloaca) ni con su peso. La ausencia de relación entre el ámbito de hogar y las variables analizadas sugiere que el tamaño del ámbito de hogar de estos reptiles, durante la época no reproductiva, respondería a otros parámetros como la abundancia de recursos, condiciones climáticas, entre otros. La baja superposición del ámbito de hogar intra e intergéneros, indicaría una evidencia indirecta de comportamiento territorial. A partir de nuestros datos y antecedentes en otras especies de saurios, consideramos que puede haber variaciones en el uso del espacio durante otras épocas del año, por lo tanto se necesitan evaluaciones complementarias a lo largo del año para observar los otros factores que determinan el tamaño del ámbito de hogar de M. tigris.The home range is the area where an individual finds the resources for its survival; therefore, the home range studies of organisms are fundamental to know their ecology and conservation status. The Loma’s lizard, Microlophus tigris is an endemic species of Peruvian central coast, whose home range has not been studied. We used the Minimum Convex Polygon method on 15 individuals (9 males and 6 females) to estimate the home range of M. tigris during the non-breeding season in Lomas de Carabayllo, Lima, Peru. We found males were significantly larger and heavier than females. However, there were no significant differences between male and female home ranges due to high variability in males. The home range size of the evaluated lizards was not related to their body size (snout vent-length) or their weight. The lack of relation between home range and the analyzed variables suggests that the home range size of M. tigris, during the non-breeding season, may be related to other parameters such as resource availability or climatic conditions. The low home range overlap between and among sexes, indirectly indicates there is territorial behavior. According to our data and natural history information of other species of lizards, we believe there may be variation in the spatial use during other seasons. Therefore, it is necessary complementary evaluations to observe other relevant factors that define home range of M. tigris

    Short-term exposure to carbamazepine causes oxidative stress on common carp (Cyprinus carpio)

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    Artículo científico en revista indizadaThe aim of this research was to determine the bioconcentration factor and if subacute exposure to carbama- zepine (2 mg L−1) modifies the oxidative state of liver, gills and brain of Cyprinus carpio. This was measured through the following biomarkers: hydroperoxide and protein carbonyl content, lipid peroxidation degree, as well as superoxide dismutase, catalase and glutathione peroxidase activity. Carbamazepine concentration in carp’s tissue was also determined by liquid chromatography with a diode arrangement detector. An increase in lipid peroxidation degree, hydroperoxide and protein carbonyl content, and a decrease in the activity of the antioxidant enzymes (P < 0.05) with respect to control was observed. Also, there is an increase in the con- centration of carbamazepina present in the organs with respect to the water in the system, which denotes bioconcentration of the drug. In conclusion, carbamazepine is bioconcentrated and produces oxidative stress on the common carp (C. carpio).Secretaría de Investigación y Posgrado del Instituto Politécnico Nacional (SIP-IPN 20170919)

    ANALISIS MULTITEMPORAL DEL CAMBIO DE COBERTURA VEGETAL DE LA MICROCUENCA EL VOLCÁN A PARTIR DE LA COMPRA DE ÁREAS ESTRATÉGICAS.

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    El objetivo de la presente investigación fue determinar los cambios de la cobertura vegetal entre los años 1992 a 2017 de la microcuenca El Volcán, Pamplona, Norte de Santander, para determinar los cambios de las coberturas antes y después de la compra de áreas estratégicas. Para esto, se seleccionaron y procesaron imágenes satelitales de 1992, 1997, 2014 y 2017 correspondientes a los años definidos; luego, se aplicó la metodología Corine Land Cover a escala 1:100000 adaptada para Colombia. El procesamiento de la información se realizó mediante el software ArcGIS con una escala 1:25000. Los resultados revelaron una recuperación positiva de las áreas de protección, mientras que la microcuenca presenta una variación entorno a la cobertura vegetal, con influencia de los sistemas productivos en áreas boscosas, áreas con procesos de recuperación y disminución de otras coberturas

    Pesticides in soil, groundwater and food in Latin America as part of one health.

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    We here report of a conference about "Pesticides in Soil, Groundwater and Food in Latin America as part of One Health" that took place at the "IV Seminario Internacional de Sanidad Agropecuaria (SISA)" in Varadero, Cuba, 8-12 May 2023. Researchers of Latin America (Argentina, Brazil, Chile, Costa Rica, Colombia, Cuba, Mexico) and Switzerland (workshop initiator) held presentations about occurrence and effects of pesticides on the environment, human health, the replacement of highly hazardous pesticides (HHP) by agroecological alternatives and the agri-food value chain. In a subsequent round table discussion, the presenters identified deficits, needs, interests and opportunities. According to them, the lack of awareness of pesticide use affects the health and safety of workers applying the chemicals. Despite Latin America representing the main agricultural area in the world with a very intense pesticide use, monitoring data of pesticides in soil, surface and groundwaters, food, as well as in humans are missing. Risks of pesticides to humans should be assessed so that authorities can withdraw or limit within "short time" the access to corresponding formulations on the market. Also, communication is not state of the art and should be improved as, e.g. the teaching of workers and farmers, how to correctly use and apply pesticides or the briefing of decision makers. Pollinators suffer from multiple stressors not the least due to pesticides, and alternatives are badly needed. On the technical side, the different analytical methods to determine residues of active ingredients and transformation products in matrices of concern should be harmonized among laboratories.Seven future actions and goals were identified to overcome the above deficits. Next steps after the publishing of this conference report are to harmonize and complete the information status of the presenters by exchanging the results/data already present. Therefore, a platform of interaction to address issues described above and to enhance collaboration shall be created. Samples of different matrices shall be exchanged to harmonize the chemical analysis and establish interlaboratory comparisons. Such activities might be facilitated by joining international associations or organizations, where researchers can offer their expertise, or by forming a new pesticide network for Central and South America that could present tailored projects to national and international organizations and funding agencies

    Taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism

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    [Objective] To evaluate the taxonomic composition of the gut microbiome in gout patients with and without tophi formation, and predict bacterial functions that might have an impact on urate metabolism.[Methods] Hypervariable V3–V4 regions of the bacterial 16S rRNA gene from fecal samples of gout patients with and without tophi (n = 33 and n = 25, respectively) were sequenced and compared to fecal samples from 53 healthy controls. We explored predictive functional profiles using bioinformatics in order to identify differences in taxonomy and metabolic pathways. [Results] We identified a microbiome characterized by the lowest richness and a higher abundance of Phascolarctobacterium, Bacteroides, Akkermansia, and Ruminococcus_gnavus_group genera in patients with gout without tophi when compared to controls. The Proteobacteria phylum and the Escherichia-Shigella genus were more abundant in patients with tophaceous gout than in controls. Fold change analysis detected nine genera enriched in healthy controls compared to gout groups (Bifidobacterium, Butyricicoccus, Oscillobacter, Ruminococcaceae_UCG_010, Lachnospiraceae_ND2007_group, Haemophilus, Ruminococcus_1, Clostridium_sensu_stricto_1, and Ruminococcaceae_UGC_013). We found that the core microbiota of both gout groups shared Bacteroides caccae, Bacteroides stercoris ATCC 43183, and Bacteroides coprocola DSM 17136. These bacteria might perform functions linked to one-carbon metabolism, nucleotide binding, amino acid biosynthesis, and purine biosynthesis. Finally, we observed differences in key bacterial enzymes involved in urate synthesis, degradation, and elimination. [Conclusion] Our findings revealed that taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism.This study was supported by the Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra” and the Grant INF-2016-01-269675 from the Consejo Nacional de Ciencia y Tecnología (CONACYT)

    Species-speciWc defense strategies of vegetative versus reproductive blades of the PaciWc kelps Lessonia nigrescens and Macrocystis integrifolia

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    Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs and optimize their overall fitness. Thus, lifetime expectation of particular tissues and their contribution to the fitness of the alga may affect defense allocation. Two brown algae common to the SE Pacific coasts, Lessonia nigrescens Bory and Macrocystis integrifolia Bory, feature important ontogenetic differences in the development of reproductive structures; in L. nigrescens blade tissues pass from a vegetative stage to a reproductive stage, while in M. integrifolia reproductive and vegetative functions are spatially separated on different blades. We hypothesized that vegetative blades of L. nigrescens with important future functions are more (or equally) defended than reproductive blades, whereas in M. integrifolia defense should be mainly allocated to reproductive blades (sporophylls), which are considered to make a higher contribution to fitness. Herein, within-plant variation in susceptibility of reproductive and vegetative tissues to herbivory and in allocation of phlorotannins (phenolics) and N-compounds was compared. The results show that phlorotannin and N-concentrations were higher in reproductive blade tissues for both investigated algae. However, preferences by amphipod grazers (Parhyalella penai) for either tissue type differed between the two algal species. Fresh reproductive tissue of L. nigrescens was more consumed than vegetative tissue, while the reverse was found in M. integrifolia, thus confirming the original hypothesis. This suggests that future fitness function might indeed be a useful predictor of anti-herbivore defense in large, perennial kelps. Results from feeding assays with artificial pellets that were made with air-dried material and extract-treated Ulva powder indicated that defenses in live algae are probably not based on chemicals that can be extracted or remain intact after air-drying and grinding up algal tissues. Instead, anti-herbivore defense against amphipod mesograzers seems to depend on structural traits of living algae

    Refined histopathological predictors of BRCA1 and BRCA2 mutation status: A large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

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    Introduction: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling. Methods: Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the

    Global Patterns and Controls of Nutrient Immobilization On Decomposing Cellulose In Riverine Ecosystems

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    Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature

    Global transpiration data from sap flow measurements : the SAPFLUXNET database

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    Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land-atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). The "sapfluxnetr" R package - designed to access, visualize, and process SAPFLUXNET data - is available from CRAN.Peer reviewe
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