120 research outputs found
Network analysis by simulated annealing of taxa and islands of Macaronesia (North Atlantic Ocean)
With the aim of explaining the role that taxa and island features have in biogeographical
patterns, we processed presence–absence matrices of all the Macaronesian native
species of ten different taxa (arthropods, birds, bryophytes, fungi, lichens, mammals,
mollusks, pteridophytes, reptiles and spermatophytes) through simulated annealing
analysis. Distribution patterns among the archipelagos were pinpointed, along with
the different biogeographic roles played by islands and species groups. All the networks
analysed resulted to be significantly modular and the structure of biogeographic
modules reflects known past connections among the archipelagos and the current
drivers of species distribution. The role assigned to the species supports some
biological (ecological amplitude, degree of endemicity) and functional (long-distance
dispersal and persistence abilities) traits of their respective biota and justifies their
position in recent models of biogeographical distribution. Whereas it was expected
that the modules identified by the spermatophytes and arthropods would reflect the
compartmentalization of archipelagos quite well, this was also the case for much more
vagile taxa, such as fungi or lichens. Conversely, results obtained for pteridophytes
and bryophytes suggest that for those taxa geographic distance and/or macroclimatic
conditions are less important than the size, age and orography of an island to
determine the modularity of island groups. On the other hand, dry, species-poor islets,
act as connectors, tending to cluster together for different taxa, independently of their
archipelagic adscription, whereas large, high, humid islands tend to form network or
module hubs representing regional centers of speciation and dispersal
Expression, purification and initial characterization of human serum albumin domain I and its cysteine 34
Human serum albumin presents in its primary structure only one free cysteine (Cys34) which constitutes the most abundant thiol of plasma. An antioxidant role can be attributed to this thiol, which is located in domain I of the protein. Herein we expressed domain I as a secretion protein using the yeast Pichia pastoris. In the initial step of ammonium sulfate precipitation, a brown pigment co-precipitated with domain I. Three chromatographic methods were evaluated, aiming to purify domain I from the pigment and other contaminants. Purification was achieved by cation exchange chromatography. The protein behaved as a noncovalent dimer. The primary sequence of domain I and the possibility of reducing Cys34 to the thiol state while avoiding the reduction of internal disulfides were confirmed by mass spectrometry. The reactivity of the thiol towards the disulfide 5,5´-dithiobis(2-nitrobenzoate) was studied and compared to that of full-length albumin. A ~24-fold increase in the rate constant was observed for domain I with respect to the entire protein. These results open the door to further characterization of the Cys34 thiol and its oxidized derivatives
Enhancing the effects of neurofeedback training: the motivational value of the reinforcers
The brain activity that is measured by electroencephalography (EEG) can be modified through operant conditioning, specifically using neurofeedback (NF). NF has been applied to several disorders claiming that a change in the erratic brain activity would be accompanied by a reduction of the symptoms. However, the expected results are not always achieved. Some authors have suggested that the lack of an adequate response may be due to an incorrect application of the operant conditioning principles. A key factor in operant conditioning is the use of reinforcers and their value in modifying behavior, something that is not always sufficiently taken into account. This work aims to clarify the relevance of the motivational value versus the purely informational value of the reinforcer. In this study, 113 subjects were randomly assigned two different reinforcer conditions: a selected reinforcer—the subjects subjectively selected the reinforcers—or an imposed reinforcer— the reinforcers were assigned by the experimenter—and both groups undertook NF sessions to enhance the sensorimotor rhythm (SMR). In addition, the selected reinforcer group was divided into two subgroups: one receiving real NF and the other one sham NF. There were no significant differences between the groups at baseline in terms of SMR amplitude. After the intervention, only those subjects belonging to the selected reinforcer group and receiving real NF increased their SMR. Our results provide evidence for the importance of the motivational value of the reinforcer in Neurofeedback succes
Survey of diseases affecting reproduction in freeze bovine semen using the polymerase chain reaction (PCR)
Las enfermedades reproductivas son una de las principales causas de los bajos índices de procreo en Uruguay. El diagnóstico de estas enfermedades se lleva a cabo por diversas técnicas de laboratorio; la mayoría de las cuales no permiten la diferenciación de las distintas subespecies de cada microorganismo, hecho que si se puede determinar por medio de la técnica de PCR. En este estudio se intentó determinar la presencia de genomas de: Diarrea Viral Bovina, Herpesvirus bovino tipos 1 y 5, Campylobacter fetus fetus y fetus veneralis y Tritrichomonas foetus foetus. Para ello, 100 pajuelas de semen de bovinos de distintas razas fueron procesadas mediante PCR utilizando “primers” específicos para cada una de las enfermedades en estudio. Todas las muestras analizadas resultaron negativas a la detección de genomas de los agentes mencionados. Esta investigación permitió comprobar el buen nivel de los centros de reproducción evaluados, repercutiendo favorablemente en la sanidad del rodeo nacional. Así mismo, el chequeo de pajuelas de semen por medio de la técnica de PCR demostró ser una herramienta necesaria que debería ser utilizada de rutina ya que permite un rápido y eficiente diagnóstico.Reproductive diseases are a major cause of low calving rates nationwide. The diagnosis of these diseases is performed by various laboratory techniques, most of them do not allow differentiation in different subspecies of each organism, a fact that it can be determined by PCR. This study attempted to determine the presence of genome of bovine viral diarrhea, bovine herpesvirus types 1 and 5, Campylobacter fetus fetus and fetus veneralis and Tritrichomonas foetus foetus. One hundred bovine semen straws were collected and PCR technique using specific primers for each of the diseases studied were applied. All samples were negative for the detection of genomes of the pathogens mentioned. This investigation allowed to check the proper level of insemmination centers evaluated, impacting positively on the health of the national herd. Likewise, the screening of bovine semen straws by PCR proved to be a necessary tool that would be used routinously for quick and efficient diagnosis.Facultad de Ciencias Veterinaria
Survey of diseases affecting reproduction in freeze bovine semen using the polymerase chain reaction (PCR)
Las enfermedades reproductivas son una de las principales causas de los bajos índices de procreo en Uruguay. El diagnóstico de estas enfermedades se lleva a cabo por diversas técnicas de laboratorio; la mayoría de las cuales no permiten la diferenciación de las distintas subespecies de cada microorganismo, hecho que si se puede determinar por medio de la técnica de PCR. En este estudio se intentó determinar la presencia de genomas de: Diarrea Viral Bovina, Herpesvirus bovino tipos 1 y 5, Campylobacter fetus fetus y fetus veneralis y Tritrichomonas foetus foetus. Para ello, 100 pajuelas de semen de bovinos de distintas razas fueron procesadas mediante PCR utilizando “primers” específicos para cada una de las enfermedades en estudio. Todas las muestras analizadas resultaron negativas a la detección de genomas de los agentes mencionados. Esta investigación permitió comprobar el buen nivel de los centros de reproducción evaluados, repercutiendo favorablemente en la sanidad del rodeo nacional. Así mismo, el chequeo de pajuelas de semen por medio de la técnica de PCR demostró ser una herramienta necesaria que debería ser utilizada de rutina ya que permite un rápido y eficiente diagnóstico.Reproductive diseases are a major cause of low calving rates nationwide. The diagnosis of these diseases is performed by various laboratory techniques, most of them do not allow differentiation in different subspecies of each organism, a fact that it can be determined by PCR. This study attempted to determine the presence of genome of bovine viral diarrhea, bovine herpesvirus types 1 and 5, Campylobacter fetus fetus and fetus veneralis and Tritrichomonas foetus foetus. One hundred bovine semen straws were collected and PCR technique using specific primers for each of the diseases studied were applied. All samples were negative for the detection of genomes of the pathogens mentioned. This investigation allowed to check the proper level of insemmination centers evaluated, impacting positively on the health of the national herd. Likewise, the screening of bovine semen straws by PCR proved to be a necessary tool that would be used routinously for quick and efficient diagnosis.Facultad de Ciencias Veterinaria
A stochastic evaluation of the validity of an animal-health survey in Uruguay
This paper introduces spreadsheet simulation models to evaluate the validity of national or regional disease surveys aimed at identifying infection in populations of farm animals. The process of evaluation includes specification or calculation of cluster-level diagnostic test sensitivity (the proportion of animals with the disease which test positive) and specificity (the proportion of animals without the disease which test negative), which are obtained from two probability distributions of the number of positive tests at individual-level expected from infected and non-infected clusters, respectively. Probability distributions for the number of positive clusters expected in a situation of the herd prevalence are specified and used to define survey properties (the survey being considered a diagnostic system), and receiver operating characteristic curves (consisting of a plot of sensitivity and specificity pairs for different cut-off values) are drawn. The result of a survey implemented to determine the prevalence of infectious bovine rhinotracheitis in dairy cattle in Uruguay, South America was used to illustrate this approach. The models can be adapted to a wide range of survey designs in animal health and production.Facultad de Ciencias Veterinaria
Pensando nuevos problemas en torno a la salud materno-infantil: embarazo adolescente y acceso a la salud en el partido de General Pueyrredón : Apuntes para una Investigación
La presente ponencia constituye un avance respecto de una investigación mayor signada por el interés de indagar en la experiencia en el acceso a la salud por parte de madres adolescentes con más de una gesta que tuvieron a sus hijos en el Hospital Interzonal Especializado Materno Infantil “Victorio Tetamanti” de la ciudad de Mar delPlata. El trabajo, de carácter interdisciplinario, pretende darle sentido a los datos estadísticos mediante la producción de datos cualitativos, obtenidos a partir de la realización de entrevistas abiertas, en profundidad, a las protagonistas. Específicamente, se busca reconstruir la trayectoria reproductiva de las madres adolescentes menores de diecinueve años con más de un hijo en un Período Intergenésico Breve (menor a dos años entre un hijo y otro), y conocer cómo perciben la accesibilidad a las instituciones de salud las madres adolescentes y acerca de los cuidados prenatales, posnatales, gestación, reproducción, anticoncepción y sexualidad y analizar su situación de vulnerabilidad.Eje Heterogeneidades en las trayectorias vitales-GT 22: Políticas Sociales, Trabajo Social y constitución de las familias como sujetos políticos.Facultad de Trabajo Socia
Assessing the impact of COVID-19 on liver cancer management (CERO-19).
BACKGROUND & AIMS: The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare systems and it may have heavily impacted patients with liver cancer (LC). Herein, we evaluated whether the schedule of LC screening or procedures has been interrupted or delayed because of the COVID-19 pandemic. METHODS: An international survey evaluated the impact of the COVID-19 pandemic on clinical practice and clinical trials from March 2020 to June 2020, as the first phase of a multicentre, international, and observational project. The focus was on patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma, cared for around the world during the first COVID-19 pandemic wave. RESULTS: Ninety-one centres expressed interest to participate and 76 were included in the analysis, from Europe, South America, North America, Asia, and Africa (73.7%, 17.1%, 5.3%, 2.6%, and 1.3% per continent, respectively). Eighty-seven percent of the centres modified their clinical practice: 40.8% the diagnostic procedures, 80.9% the screening programme, 50% cancelled curative and/or palliative treatments for LC, and 41.7% modified the liver transplantation programme. Forty-five out of 69 (65.2%) centres in which clinical trials were running modified their treatments in that setting, but 58.1% were able to recruit new patients. The phone call service was modified in 51.4% of centres which had this service before the COVID-19 pandemic (n = 19/37). CONCLUSIONS: The first wave of the COVID-19 pandemic had a tremendous impact on the routine care of patients with liver cancer. Modifications in screening, diagnostic, and treatment algorithms may have significantly impaired the outcome of patients. Ongoing data collection and future analyses will report the benefits and disadvantages of the strategies implemented, aiding future decision-making. LAY SUMMARY: The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare systems globally. Herein, we assessed the impact of the first wave pandemic on patients with liver cancer and found that routine care for these patients has been majorly disrupted, which could have a significant impact on outcomes
Mapping Genetic Diversity of Cherimoya (Annona cherimola Mill.): Application of Spatial Analysis for Conservation and Use of Plant Genetic Resources
There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively
Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents
The Adapting Agriculture to Climate Change Project set out to improve the diversity,
quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and
2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed
collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we
describe the implementation of the 25 national collecting programs and present the key results. A total
of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety
duplicated in national and international genebanks, and made available through the Multilateral
System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant
Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most
collected genepools, although the greatest number of primary genepool collections were made for
rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets
were best achieved. Several of the newly collected samples have already been used in pre-breeding
programs to adapt crops to future challenges.info:eu-repo/semantics/publishedVersio
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