193 research outputs found
Recent jaguar records confirm the conservation value of the Baritú–TariquÃa corridor between Argentina and Bolivia
Effective transboundary corridors play a crucial role in jaguar Panthera onca conservation. Local residents reported jaguar sightings along the Baritú–TariquÃa Biological Corridor, which prompted us to carry out this camera-trap survey. We surveyed an area of 1,243 km2 across the corridor to confirm jaguar presence. We used 50 single camera stations, with cameras placed c. 5 km apart. We placed the cameras along trails, streams and mountain ridges. We recorded jaguars at seven sites across the Corridor; at least three different individuals were identified. These records confirm the presence of the jaguar in the Baritú–TariquÃa Biological Corridor between Argentina and Bolivia, a trans-frontier area of the Austral Yungas facing multiple threats but hosting one of the southernmost jaguar populations. Conservation efforts in border regions can promote collaboration and synergies between agencies and other conservation stakeholders, with important implications for wide-ranging predators such as jaguars and their habitats
An algorithm to represent inbreeding trees
Recent work has proven the existence of extreme inbreeding in a European ancestry sample taken from the contemporary UK population (Yengo et al., 2019). This result brings our attention again to a math problem related to inbreeding family trees and diversity. Groups with a finite number of individuals could give a variety of genetic relationships. In previous works (Caruso and Jarne, 2015; Caruso and Jarne, 2014; Jarne and Caruso, 2019), we have addressed the issue of building inbreeding trees for biparental reproduction using Markovian models. Here, we extend these studies by presenting an algorithm to generate and represent inbreeding trees with no overlapping generations. We explicitly assume a two-gender reproductory scheme, and we pay particular attention to the links between nodes. We show that even for a simple case with a relatively small number of nodes in the tree, there are a large number of possible ways to rearrange the links between generations. We present an open-source python code to generate the tree graph, the adjacency matrix, and the histogram of the links for each different tree representation. We show how this mapping reflects the difference between tree realizations, and how valuable information may be extracted upon inspection of these matrices. The algorithm includes a feature to average several tree realizations, obtain the connectivity distribution, and calculate the mean value and standard deviation. We used this feature to compare trees with a different number of generations and nodes. The code presented here, available in Git-Hub, may be easily modified to be applied to other areas of interest involving connections between individuals, extend the study to add more characteristics of the different nodes, etc.Instituto de FÃsica de LÃquidos y Sistemas Biológico
Conflict to coexistence: riding the challenges arising from an ever-expanding human-wildlife interface
A novel promising laccase from the psychrotolerant and halotolerant Antarctic marine Halomonas sp. M68 strain
Microbial communities inhabiting the Antarctic Ocean show psychrophilic and halophilic adaptations conferring interesting properties to the enzymes they produce, which could be exploited in biotechnology and bioremediation processes. Use of cold- and salt-tolerant enzymes allows to limit costs, reduce contaminations, and minimize pretreatment steps. Here, we report on the screening of 186 morphologically diverse microorganisms isolated from marine biofilms and water samples collected in Terra Nova Bay (Ross Sea, Antarctica) for the identification of new laccase activities. After primary screening, 13.4 and 10.8% of the isolates were identified for the ability to oxidize 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and the dye azure B, respectively. Amongst them, the marine Halomonas sp. strain M68 showed the highest activity. Production of its laccase-like activity increased six-fold when copper was added to culture medium. Enzymatic activity-guided separation coupled with mass spectrometry identified this intracellular laccase-like protein (named Ant laccase) as belonging to the copper resistance system multicopper oxidase family. Ant laccase oxidized ABTS and 2,6-dimethoxy phenol, working better at acidic pHs The enzyme showed a good thermostability, with optimal temperature in the 40–50°C range and maintaining more than 40% of its maximal activity even at 10°C. Furthermore, Ant laccase was salt- and organic solvent-tolerant, paving the way for its use in harsh conditions. To our knowledge, this is the first report concerning the characterization of a thermo- and halo-tolerant laccase isolated from a marine Antarctic bacterium
People and jaguars: New insights into the role of social factors in an old conflict
Throughout its range in Latin America, the jaguar Panthera onca is threatened by habitat loss and fragmentation, and by conflict as a result of coexistence with people. This Near Threatened species is a top predator, and is often illegally hunted. Understanding people's attitudes and perceptions and the factors that could influence them is crucial for the conservation of this species. In this study we assess how knowledge, attitudes and perceptions among people in northern Argentina regarding jaguars vary depending on their level of education, age and occupation. We interviewed 810 people living in and around 10 protected areas in northern Argentina. Positive perceptions and attitudes towards the jaguar were associated with economic benefits that people may receive from the species' presence, such as income from tourism. Unexpectedly, higher levels of formal education were not associated with more positive attitudes and perceptions. Negative attitudes and perceptions towards the species were determined by fear; people see jaguars as a threat to their lives. This study shows that the socio-economic factors that affect the level of tolerance towards jaguars are not related only to economic losses. Our findings provide information for the design, implementation and evaluation of jaguar conservation projects in Argentina.Fil: Caruso, MarÃa Flavia. Administración de Parques Nacionales. Delegación Regional del Noroeste; Argentina. Jaguares En El LÃmite; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta; ArgentinaFil: Perovic, Pablo Gastón. Jaguares En El LÃmite; Argentina. Administración de Parques Nacionales. Delegación Regional del Noroeste; ArgentinaFil: Tálamo, Andrés. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Trigo, Carolina Beatriz. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Andrade DÃaz, MarÃa S.. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Marás, Gustavo Arnaldo. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Saravia, Diego. Universidad Nacional de Salta; ArgentinaFil: Sillero-Zubiri, Claudio. University of Oxford; Reino Unido. The Recanati-Kaplan Centre; Reino Unido. Born Free Foundation; Reino UnidoFil: Altrichter, Mariana. Prescott college; Estados Unido
Metabolic inflexibility is a feature of women with polycystic ovary syndrome and is associated with both insulin resistance and hyperandrogenism
Context: Metabolic inflexibility, ie, the impaired ability of the body to switch from fat to carbohydrate oxidation under insulin-stimulated conditions, is associated with insulin resistance. This alteration in metabolic plasticity can lead to organ dysfunction and is considered a key issue among the abnormalities of the metabolic syndrome. It is still unknown whether this phenomenon occurs in women with polycystic ovary syndrome (PCOS).
Objective: Our objective was to examine whether metabolic inflexibility is a feature of PCOS women and whether hyperandrogenism may contribute to this phenomenon.
Design and Patients: Eighty-nine Caucasian women with PCOS were submitted to hyperinsulinemic-euglycemic clamp. Respiratory exchange ratios were evaluated at baseline and during hyperinsulinemia by indirect calorimetry to quantify substrate oxidative metabolism. Total testosterone was measured by liquid chromatography mass spectrometry and free testosterone by equilibrium dialysis. Setting: Outpatients were seen in a tertiary care academic center.
Main Outcome Measure: Metabolic flexibility was assessed by the change in respiratory quotient upon insulin stimulation.
Results: Sixty-five of the 89 PCOS women(73%) had increased serum free testosterone, 68 (76%) were insulin resistant, and 62 (70%) had an impaired metabolic flexibility. Comparison of hyperandrogenemic and normoandrogenemic women showed that the 2 subgroups were of similar age but differed in terms of several anthropometric and metabolic features. In particular, hyperandrogenemic women had greater body mass index (32.9 +/- 1.0 vs 24.7 +/- 0.9 kg/m(2), P < .001) and lower glucose utilization during the clamp (9.2 +/- 0.4 vs 10.9 +/- 0.7 mg/kg fat-free mass . min, P < .023) and metabolic flexibility (0.09 +/- 0.06 vs 0.12 +/- 0.01, P < .014). In univariate analysis, metabolic flexibility was associated with several anthropometric, endocrine, and metabolic features. In multivariate analysis, this feature was directly associated with baseline respiratory quotient and insulin sensitivity and inversely with free testosterone and free fatty acids concentrations under insulin suppression (R-2 = 0.634, P < .001).
Conclusions: Metabolic inflexibility is a feature of PCOS women. Both insulin resistance and androgen excess might contribute to this abnormality
Are white-lipped peccaries from Argentinean Yungas looking to a promising future?
The white-lipped peccary (Tayassu pecari) is considered a key species for its role as an ecosystem engineer. Given their important ecological function, there is a great concern in the scientific community regarding the many reports of disappearances or great abundance reductions throughout its distribution (from southern Mexico to northern Argentina). Based on an extensive survey effort, we report new data of presence of WLP after a period of no detections in the Argentine Yungas. The study was conducted in the Yungas ecoregion, provinces of Jujuy and Salta, Argentina. Data was collected from camera trap, direct sightings and footprints during 2013–2021. From a total of 30,186 trap nights, we obtained 8 WLP detections. There were no detections before 2017, while as of 2018 there was at least one camera trap record in each of the years. Additionally, opportunistic records were obtained yearly from 2019 to 2021. The period without detections could be related to a period of a population cycle, as suggested in different regions of America during the last century, being disease the most likely cause. These cycles generally follow a pattern of a rapid population decline, a period of absence or low abundance followed by slow population growth. We believe that if the trend continues and the number of detections increases, we could be facing the early stages of the increase phase in the WLP population cycle in the Argentine Yungas.Facultad de Ciencias Naturales y Muse
Reversal of gastrointestinal carcinoma-induced immunosuppression and induction of antitumoural immunity by a combination of cyclophosphamide and gene transfer of IL-12
Immunotherapy-based strategies for gastrointestinal carcinomas (GIC) have been exploited so far, but these approaches have to face strong mechanisms of immune escape induced by tumours. We previously demonstrated that sub-therapeutic doses of an adenovirus expressing IL-12 genes (AdIL-12) mediated a potent antitumour effect against subcutaneous (s.c.) colorectal carcinomas (CRC) in mice pre-treated with low doses of cyclophosphamide (Cy). In our study we used this combination to assess its impact on the immunosuppressive microenvironment. In s.c. CRC model we demonstrated that non-responder mice failed to decrease Tregs in tumour, spleen and peripheral blood. Reconstitution of Tregs into tumour-bearing mice treated with combined therapy abolished the antitumoural effect. In addition, Cy + AdIL-12 modified Tregs functionality by inhibiting the in vitro secretion of IL-10 and TGF-β and their ability to inhibit dendritic cells activation. Combined treatment decreased the number of myeloid-derived suppressor cells (MDSCs) in comparison to non-treated mice and, interestingly, administration of Tregs restored splenic MDSCs population. Furthermore, combined therapy potently generated specific cytotoxic IFN-γ-secreting CD4+ T cells able to eradicate established CRC tumours after adoptive transfer. Finally, we evaluated the combination on disseminated CRC and pancreatic carcinoma (PC). Cy + AdIL-12 were able to eradicate liver metastatic CRC (47%) and PC tumour nodules (40%) and to prolong animal survival. The results of this study support the hypothesis that Cy + AdIL-12 might be a valid immunotherapeutic strategy for advanced GIC.Fil: Malvicini, Mariana. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Ingolotti, Mariana. Universidad Austral; ArgentinaFil: Piccioni, Flavia Valeria. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: GarcÃa, Mariana Gabriela. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Bayo Fina, Juan Miguel. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Atorrasagasti, MarÃa Catalina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Alaniz, Laura Daniela. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Aquino, Jorge Benjamin. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; ArgentinaFil: Espinoza, Jaime A.. Universidad Adolfo Ibañez; Chile. Universidad de La Frontera; ChileFil: Gidekel, Manuel. Universidad Adolfo Ibañez; ChileFil: Scharovsky, Olga Graciela. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Medicas. Instituto de Genetica Experimental; ArgentinaFil: Matar, Pablo. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Medicas. Instituto de Genetica Experimental; ArgentinaFil: Mazzolini Rizzo, Guillermo Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Austral; Argentin
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