Water bears dominated cryoconite hole ecosystems: densities, habitat preferences and physiological adaptations of Tardigrada on an alpine glacier

We investigated the Forni Glacier and the surrounding area in the Alps in terms of habitat preferences, densities, dispersal and desiccation tolerance of glacier tardigrades, which are one of the most common faunal representatives and top consumers in supraglacial ecosystems. To do so, we sampled supraglacial environments (cryoconite holes, debris from ice surface, dirt cones and moraine, mosses from supraglacial stones) and non-glacial habitats (mosses, freshwater sediments and algae), and we installed air traps on the glacier and the nearby area. We found that cryoconite holes on the Forni Glacier are exclusively dominated by one metazoan group of tardigrades, representing one species, Hypsibius klebelsbergi (identified by morphological and molecular approaches). Tardigrades were found in 100% of cryoconite holes and wet supraglacial sediment samples and reached up to 172 ind./ml. Additionally, we found glacier tardigrades in debris from dirt cones and sparsely in supraglacial mosses. Glacier tardigrades were absent from freshwater and terrestrial samples collected from non-glacial habitats. Despite the fact that H. klebelsbergi is a typical aquatic species, we showed it withstands desiccation in sediments, but in low temperatures only. Treatments conducted in higher temperatures and water only showed low or no recovery. We suspect successful dispersal with wind might have taken place only when tardigrades desiccated in sediments and were passively transported by cold wind. Limited ability to withstand high temperatures and desiccation may be potential barriers preventing glacier tardigrades inhabiting new, even apparently suitable high mountain water bodies like temporary rock pools

Fine-scale spatial heterogeneity of invertebrates within cryoconite holes

Cryoconite holes (water-filled reservoirs) are considered ecologically simple ecosystems but represent biological hotspots of biodiversity on glaciers. In order to check for fine-scale spatial distribution of metazoans on the bottom of the holes, in this study, we analysed three groups of grazing invertebrates as a model: tardigrades, rotifers, and mites. We addressed differences within cryoconite holes comparing the distribution of invertebrates within and between separate holes and between glaciers at a worldwide scale. We divided each cryoconite hole into three sampling zones (established in relation to water flow on a glacier) and collected nine subsamples within cryoconite holes on glaciers in the Arctic (Longyearbreen), Norway (Blåisen), the Alps (Forni) and maritime Antarctic (Ecology Glacier). Generally, we found no consistent difference in sampling zones within cryoconite holes, which suggests homogeneity on the hole floors. However, we did find strong differences and high heterogeneity between subsamples, even within the same zone. Invertebrate densities ranged between 52 and 426 individuals per ml in subsamples collected from the same hole. We found from zero to four trdigrade species in the cryoconite hole on Longyearbreen. Our results show that benthic animals in cryoconite holes in various climatic zones have heterogeneous spatial distribution, even if no preference could be highlighted for upstream versus downstream areas with respect to water flow. The distribution of invertebrates may result from ecosystem disturbance by flushing water and animals’ active movement. Cryoconite holes, usually considered to be simple ecosystems, seem to be complex habitats where hidden spatial heterogeneity may affect abundance and diversity of organisms

Estabilidade das propriedades hidráulicas do solo em um sistema de plantio direto em longo prazo

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam) from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM) model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC) for these soils, but not the hydraulic conductivity (K) vs tension (h) curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.Nos últimos anos, o sistema plantio direto (NT) tem aumentado. Alguns autores indicam que os atributos físicos do solo ficam estáveis após anos cultivando nesse sistema, sendo esse fato discutido por outros autores. O objetivo deste trabalho foi avaliar o efeito do último cultivo após a rotação (1º ano: milho; 2º ano: soja; e 3º ano: trigo/soja) sobre a configuração do sistema poroso do solo e das suas propriedades hidráulicas de diferentes tipos de textura (solo 1: franco; e solo 2: franco-arenoso) da região do pampa argentino, em NT por um longo prazo, para determinar se a estabilidade das propriedades físicas do solo independe do momento da rotação. Adicionalmente, foram comparados os procedimentos para avaliar a macroporosidade, bem como avaliada a eficiência da função de pedotransferência ROSETTA, para estimar os parâmetros do modelo de van Genuchten-Mualen (VGM) desses solos. A configuração do sistema poroso do solo e as propriedades hidráulicas não foram estáveis e se alteraram em razão da rotação da cultura e do último cultivo utilizado na rotação em ambos os solos. Nos dois locais, a condutividade hidráulica do solo saturado (K0 ), a macroporosidade (εma) e o raio médio ponderado do poro por fluxo (R0ma) aumentaram do 1º para o 2º ano da rotação de culturas e isso se atribuiu ao aumento de macroporos condutores de água pra as raízes de milho. O modelo VGM descreveu adequadamente a curva de retenção de água (WCR) nos dois solos, porém não foi adequada para as curvas de condutividade hidráulica (K) vs tensão (h). A função ROSETTA não foi eficiente para a estimativa dos parâmetros. Em resumo, os valores médios de K0 variaram entre 0,74 e 3,88 cm h-1. Com relação às propriedades físicas do solo no NT, o efeito do cultivo deve ser considerado.Facultad de Ciencias Agrarias y Forestale

Estabilidade das propriedades hidráulicas do solo em um sistema de plantio direto em longo prazo

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam) from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM) model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC) for these soils, but not the hydraulic conductivity (K) vs tension (h) curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.Nos últimos anos, o sistema plantio direto (NT) tem aumentado. Alguns autores indicam que os atributos físicos do solo ficam estáveis após anos cultivando nesse sistema, sendo esse fato discutido por outros autores. O objetivo deste trabalho foi avaliar o efeito do último cultivo após a rotação (1º ano: milho; 2º ano: soja; e 3º ano: trigo/soja) sobre a configuração do sistema poroso do solo e das suas propriedades hidráulicas de diferentes tipos de textura (solo 1: franco; e solo 2: franco-arenoso) da região do pampa argentino, em NT por um longo prazo, para determinar se a estabilidade das propriedades físicas do solo independe do momento da rotação. Adicionalmente, foram comparados os procedimentos para avaliar a macroporosidade, bem como avaliada a eficiência da função de pedotransferência ROSETTA, para estimar os parâmetros do modelo de van Genuchten-Mualen (VGM) desses solos. A configuração do sistema poroso do solo e as propriedades hidráulicas não foram estáveis e se alteraram em razão da rotação da cultura e do último cultivo utilizado na rotação em ambos os solos. Nos dois locais, a condutividade hidráulica do solo saturado (K0 ), a macroporosidade (εma) e o raio médio ponderado do poro por fluxo (R0ma) aumentaram do 1º para o 2º ano da rotação de culturas e isso se atribuiu ao aumento de macroporos condutores de água pra as raízes de milho. O modelo VGM descreveu adequadamente a curva de retenção de água (WCR) nos dois solos, porém não foi adequada para as curvas de condutividade hidráulica (K) vs tensão (h). A função ROSETTA não foi eficiente para a estimativa dos parâmetros. Em resumo, os valores médios de K0 variaram entre 0,74 e 3,88 cm h-1. Com relação às propriedades físicas do solo no NT, o efeito do cultivo deve ser considerado.Fil: Lozano, Luis Alberto. Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soracco, Carlos Germán. Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buda, Vicente S.. Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Sarli, Guillermo O.. Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Filgueira, Roberto Raul. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Rectal bleeding by Dieulafoy-like lesion: successful endoscopic treatment

A 81-year old woman affected by chronic renal failure, non insulin-dependent diabetes mellitus (NIDM) and hypertension, had an severe anemia massive hematochezia. The colonoscopy could not localize the bleeding site except some blood spots in the rectum. The patient was readmitted after 1 month with hypovolemic shock by massive hematochezia and required several blood transfusions. The endoscopic examination showed an important arterial bleeding treated successfully with epinephrine and bipolar elettro-coagulation (BICAP). We suggested that the patient presented a Dieulafoy-like lesion; this is an uncommon gastrointestinal cause of bleeding due to a defect of a submucosal artery without evidence of atherosclerosis or vasculitis. Both chronic renal failure and age could be considered as predisponent factors in this patient. Hematochezia is the most important sign and is often complicated by haemorrhagic shock. The diagnosis was delayed due to the difficulty in localizing the bleeding site; moreover, the patient needed several blood transfusions. The arteriographic diagnosis associated to endoscopic treatment by epinephrine and BICAP enabled a successful therapy

Increased Risk of Hepatocellular Carcinoma and Liver Cirrhosis in Vinyl Chloride Workers: Synergistic Effect of Occupational Exposure with Alcohol Intake

Hepatocellular carcinoma (HCC) and liver cirrhosis (LC) are not well-established vinyl chloride monomer (VCM)–induced diseases. Our aim was to appraise the role of VCM, alcohol intake, and viral hepatitis infection, and their interactions, in the etiology of HCC and LC. Thirteen cases of HCC and 40 cases of LC were separately compared with 139 referents without chronic liver diseases or cancer in a case–referent study nested in a cohort of 1,658 VCM workers. The odds ratios (ORs) and the 95% confidence intervals (CIs) were estimated by common methods and by fitting models of logistic regression. We used Rothman’s synergy index (S) to evaluate interactions. By holding the confounding factors constant at logistic regression analysis, each extra increase of 1,000 ppm × years of VCM cumulative exposure was found to increase the risk of HCC by 71% (OR = 1.71; 95% CI, 1.28–2.44) and the risk of LC by 37% (OR = 1.37; 95% CI, 1.13–1.69). The joint effect of VCM exposure above 2,500 ppm × years and alcohol intake above 60 g/day resulted in ORs of 409 (95% CI, 19.6–8,553) for HCC and 752 (95% CI, 55.3–10,248) for LC; both S indexes suggested a synergistic effect. The joint effect of VCM exposure above 2,500 ppm × years and viral hepatitis infection was 210 (95% CI, 7.13–6,203) for HCC and 80.5 (95% CI, 3.67–1,763) for LC; both S indexes suggested an additive effect. In conclusion, according to our findings, VCM exposure appears to be an independent risk factor for HCC and LC interacting synergistically with alcohol consumption and additively with viral hepatitis infection

Effective Label-Free Sorting of Multipotent Mesenchymal Stem Cells from Clinical Bone Marrow Samples

Mesenchymal stem cells (MSC) make up less than 1% of the bone marrow (BM). Several methods are used for their isolation such as gradient separation or centrifugation, but these methodologies are not direct and, thus, plastic adherence outgrowth or magnetic/fluorescent-activated sorting is required. To overcome this limitation, we investigated the use of a new separative technology to isolate MSCs from BM; it label-free separates cells based solely on their physical characteristics, preserving their native physical properties, and allows real-time visualization of cells. BM obtained from patients operated for osteochondral defects was directly concentrated in the operatory room and then analyzed using the new technology. Based on cell live-imaging and the sample profile, it was possible to highlight three fractions (F1, F2, F3), and the collected cells were evaluated in terms of their morphology, phenotype, CFU-F, and differentiation potential. Multipotent MSCs were found in F1: higher CFU-F activity and differentiation potential towards mesenchymal lineages compared to the other fractions. In addition, the technology depletes dead cells, removing unwanted red blood cells and non-progenitor stromal cells from the biological sample. This new technology provides an effective method to separate MSCs from fresh BM, maintaining their native characteristics and avoiding cell manipulation. This allows selective cell identification with a potential impact on regenerative medicine approaches in the orthopedic field and clinical applications

Trophic and symbiotic links between obligate-glacier water bears (Tardigrada) and cryoconite microorganisms

Insights into biodiversity and trophic webs are important for understanding ecosystem functions. Although the surfaces of glaciers are one of the most productive and biologically diverse parts of the cryosphere, the links between top consumers, their diet and microbial communities are poorly understood. In this study, for the first time we investigated the relationships between bacteria, fungi and other microeukaryotes as they relate to tardigrades, microscopic metazoans that are top consumers in cryoconite, a biologically rich and productive biogenic sediment found on glacier surfaces. Using metabarcoding (16S rDNA for bacteria, ITS1 for fungi, and 18S rDNA for other microeukaryotes), we analyzed the microbial community structures of cryoconite and compared them with the community found in both fully fed and starved tardigrades. The community structure of each microbial group (bacteria, fungi, microeukaryotes) were similar within each host group (cryoconite, fully fed tardigrades and starved tardigrades), and differed significantly between groups, as indicated by redundancy analyses. The relative number of operational taxonomic units (ZOTUs, OTUs) and the Shannon index differed significantly between cryoconite and tardigrades. Species indicator analysis highlighted a group of microbial taxa typical of both fully fed and starved tardigrades (potential commensals), like the bacteria of the genera Staphylococcus and Stenotrophomonas, as well as a group of taxa typical of both cryoconite and fully fed tardigrades (likely part of the tardigrade diet; bacteria Flavobacterium sp., fungi Preussia sp., algae Trebouxiophyceae sp.). Tardigrades are consumers of bacteria, fungi and other microeukaryotes in cryoconite and, being hosts for diverse microbes, their presence can enrich the microbiome of glaciers

Estabilidade das propriedades hidráulicas do solo em um sistema de plantio direto em longo prazo

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam) from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM) model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC) for these soils, but not the hydraulic conductivity (K) vs tension (h) curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.Nos últimos anos, o sistema plantio direto (NT) tem aumentado. Alguns autores indicam que os atributos físicos do solo ficam estáveis após anos cultivando nesse sistema, sendo esse fato discutido por outros autores. O objetivo deste trabalho foi avaliar o efeito do último cultivo após a rotação (1º ano: milho; 2º ano: soja; e 3º ano: trigo/soja) sobre a configuração do sistema poroso do solo e das suas propriedades hidráulicas de diferentes tipos de textura (solo 1: franco; e solo 2: franco-arenoso) da região do pampa argentino, em NT por um longo prazo, para determinar se a estabilidade das propriedades físicas do solo independe do momento da rotação. Adicionalmente, foram comparados os procedimentos para avaliar a macroporosidade, bem como avaliada a eficiência da função de pedotransferência ROSETTA, para estimar os parâmetros do modelo de van Genuchten-Mualen (VGM) desses solos. A configuração do sistema poroso do solo e as propriedades hidráulicas não foram estáveis e se alteraram em razão da rotação da cultura e do último cultivo utilizado na rotação em ambos os solos. Nos dois locais, a condutividade hidráulica do solo saturado (K0 ), a macroporosidade (εma) e o raio médio ponderado do poro por fluxo (R0ma) aumentaram do 1º para o 2º ano da rotação de culturas e isso se atribuiu ao aumento de macroporos condutores de água pra as raízes de milho. O modelo VGM descreveu adequadamente a curva de retenção de água (WCR) nos dois solos, porém não foi adequada para as curvas de condutividade hidráulica (K) vs tensão (h). A função ROSETTA não foi eficiente para a estimativa dos parâmetros. Em resumo, os valores médios de K0 variaram entre 0,74 e 3,88 cm h-1. Com relação às propriedades físicas do solo no NT, o efeito do cultivo deve ser considerado.Facultad de Ciencias Agrarias y Forestale

I.S.Mu.L.T. Achilles Tendon Ruptures Guidelines

This work provides easily accessible guidelines for the diagnosis, treatment and rehabilitation of Achilles tendon ruptures. These guidelines could be considered as recommendations for good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care for the individual patient and rationalize the use of resources. This work is divided into two sessions: 1) questions about hot topics; 2) answers to the questions following Evidence Based Medicine principles. Despite the frequency of the pathology andthe high level of satisfaction achieved in treatment of Achilles tendon ruptures, a global consensus is lacking. In fact, there is not a uniform treatment and rehabilitation protocol used for Achilles tendon ruptures