568 research outputs found

    Song learning in the Rufous-collared Sparrow (Zonotrichia capensis)

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    Se investigó el papel del aprendizaje en el desarrollo del canto del chingolo, mediante la comparación de los cantos primarios desarrollados por 10 sujetos capturados a diferentes edades y criados en aislación acústica o entrenados con tutores grabados conespecíficos. Los sujetos capturados antes de los 10 días de vida, y privados de modelos de canto para escuchar, desarrollaron cantos anormales, carentes de introducción (tema) y trino. En contraposición, los sujetos capturados y aislados a partir de los 35-40 días de vida desarrollaron buenas copias de los cantos de su población natal. Estos hechos sugieren que la exposición a los cantos de los adultos del área donde se crían los pichones es suficiente para la imitación del dialecto. Los sujetos capturados y expuestos tempranamente a grabaciones de canto, desarrollaron cantos con algunas de las características del modelo utilizado, lo cual muestra la importancia de la experiencia acústica temprana en el aprendizaje del canto. No se hallaron evidencias de la copia del tutor grabado con posterioridad a los 40 días de vida.The role of learning in the development of the Rufous-collared Sparrow's song was investigated comparing the primary song of 10 subjects captured at different ages and raised in acoustic isolation or trained with conspecific tape-tutors, The subjects captured before day 10 of age and deprived of song models developed abnormal songs, lacking introduction (theme) and trill, In contrast, subjects captured and isolated after day 35-40 of age developed good copies of the song of their natal population, These facts suggest that the acoustical experience with the song from their natal area is sufficient for the imitation of their natal dialecto Subjects captured as nestlings and tape-tutored with natal and alien dialects developed songs with some features of the models, indicating the importance of the early acoustic experience in development of songoNo evidences of song copying were found when tape-tutoring started after day 40 of age

    Song learning in the Rufous-collared Sparrow (<i>Zonotrichia capensis</i> )

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    Se investigó el papel del aprendizaje en el desarrollo del canto del chingolo, mediante la comparación de los cantos primarios desarrollados por 10 sujetos capturados a diferentes edades y criados en aislación acústica o entrenados con tutores grabados conespecíficos. Los sujetos capturados antes de los 10 días de vida, y privados de modelos de canto para escuchar, desarrollaron cantos anormales, carentes de introducción (tema) y trino. En contraposición, los sujetos capturados y aislados a partir de los 35-40 días de vida desarrollaron buenas copias de los cantos de su población natal. Estos hechos sugieren que la exposición a los cantos de los adultos del área donde se crían los pichones es suficiente para la imitación del dialecto. Los sujetos capturados y expuestos tempranamente a grabaciones de canto, desarrollaron cantos con algunas de las características del modelo utilizado, lo cual muestra la importancia de la experiencia acústica temprana en el aprendizaje del canto. No se hallaron evidencias de la copia del tutor grabado con posterioridad a los 40 días de vida.The role of learning in the development of the Rufous-collared Sparrow's song was investigated comparing the primary song of 10 subjects captured at different ages and raised in acoustic isolation or trained with conspecific tape-tutors, The subjects captured before day 10 of age and deprived of song models developed abnormal songs, lacking introduction (theme) and trill, In contrast, subjects captured and isolated after day 35-40 of age developed good copies of the song of their natal population, These facts suggest that the acoustical experience with the song from their natal area is sufficient for the imitation of their natal dialecto Subjects captured as nestlings and tape-tutored with natal and alien dialects developed songs with some features of the models, indicating the importance of the early acoustic experience in development of songoNo evidences of song copying were found when tape-tutoring started after day 40 of age

    Neural set point for the control of arterial pressure: role of the nucleus tractus solitarius

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    <p>Abstract</p> <p>Background</p> <p>Physiological experiments have shown that the mean arterial blood pressure (MAP) can not be regulated after chemo and cardiopulmonary receptor denervation. Neuro-physiological information suggests that the nucleus tractus solitarius (NTS) is the only structure that receives information from its rostral neural nuclei and from the cardiovascular receptors and projects to nuclei that regulate the circulatory variables.</p> <p>Methods</p> <p>From a control theory perspective, to answer if the cardiovascular regulation has a set point, we should find out whether in the cardiovascular control there is something equivalent to a comparator evaluating the error signal (between the rostral projections to the NTS and the feedback inputs). The NTS would function as a comparator if: a) its lesion suppresses cardiovascular regulation; b) the negative feedback loop still responds normally to perturbations (such as mechanical or electrical) after cutting the rostral afferent fibers to the NTS; c) perturbation of rostral neural structures (RNS) to the NTS modifies the set point without changing the dynamics of the elicited response; and d) cardiovascular responses to perturbations on neural structures within the negative feedback loop compensate for much faster than perturbations on the NTS rostral structures.</p> <p>Results</p> <p>From the control theory framework, experimental evidence found currently in the literature plus experimental results from our group was put together showing that the above-mentioned conditions (to show that the NTS functions as a comparator) are satisfied.</p> <p>Conclusions</p> <p>Physiological experiments suggest that long-term blood pressure is regulated by the nervous system. The NTS functions as a comparator (evaluating the error signal) between its RNS and the cardiovascular receptor afferents and projects to nuclei that regulate the circulatory variables. The mean arterial pressure (MAP) is regulated by the feedback of chemo and cardiopulmonary receptors and the baroreflex would stabilize the short term pressure value to the prevailing carotid MAP. The discharge rates of rostral neural projections to the NTS would function as the set point of the closed and open loops of cardiovascular control. No doubt, then, the RNS play a functional role not only under steady-state conditions, but also in different behaviors and pathologies.</p

    Evaluation of the alerted detection hypothesis in tbe song of tbe Rufous-collared Sparrow : l. Experiments with complete and sectioned songs

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    La Hipótesis de la Detección Alertada sugiere que la diferenciación estructural del canto de las aves constituye una adaptación para la comunicación a distancia en un ambiente ruidoso. De acuerdo con esta hipótesis, las introducciones actuarian como elementos "alertadores" que avisan a los potenciales receptores de la llegada de la porción informativa de la señal, contenida en las restantes porciones del canto. Nosotros evaluamos la validez de la Hipótesis de la Detección Alertada en el chingolo (Zonotrichia capensis), a través de un estudio de las respuestas evocadas por los playbacks con cantos completos y sus partes constituyentes aisladas (tema y trino). Los chingolos respondieron más a los cantos completos que a los temas y trinos por separado, mientras que la respuesta a estos últimos fue aproximadamente equivalente. Estos resultados difieren de las predicciones de la Hipótesis de la Detección Alertada según las cuales tanto el canto completo como el trino serian los únicos estimulos capaces de desencadenar respuestas significativas de similar intensidad.The Alerted Detection Hypothesis suggests that the bird-song structure is adaptive for long-range communication in a noisy environment. According to this hypothesis, the introductory part of the song may act as an "alerting" element, which warns potential receptors about the arrival of the informa tive portion of the signal, contained in the remaining parts of the songs. We evaluated the Alerted Detection Hypothesis in the Rufous-collared Sparrow (Zonotrichia capensis) using a playback design with complete songs as well as their isolated constitutive parts (theme and tri1l). The Rufous-collared Sparrows responded more to the complete songs than to the themes and trills. However, both themes and tri1ls evoked a similar response. These results contrast with those predicted by the Alerted Detection Hypothesis, which states that only complete songs and tri1ls would have elicited significant responses of similar intensity

    Desempeño productivo y rendimiento de canal en pavos alimentados con harina de plumas tratadas con NaOH

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    RESUMEN Objetivo. Evaluar el desempeño productivo y el rendimiento de la canal en pavos en crecimiento alimentados con dietas elaboradas con harina de plumas (HP). Materiales y métodos. Los tratamientos fueron una dieta control y dos dietas experimentales con harina de plumas tratada con 50 ó 100 g de NaOH/kg. Se utilizó un diseño de bloques al azar. El consumo de alimento y el peso de los animales se registró cada dos semanas. Los datos del desempeño productivo se analizaron con el procedimiento MIXED del programa estadístico SAS. El rendimiento de la canal se analizó con el procedimiento GLM del programa estadístico SAS. Resultados. Los pavos que consumieron la dieta testigo tuvieron mejores ganancias de peso (GP), consumo de alimento (CA), peso de la canal y de sus partes (p<0.05) que aquellas con harina de plumas. Sin embargo, se observó una mayor GP, CA, peso de la canal y del muslo (p<0.05) cuando se trató la harina de plumas con 100 g de NaOH/kg. Conclusiones. Los resultados obtenidos indican que la utilización de harina de plumas disminuyó el comportamiento productivo y el rendimiento de canal en los pavos. Sin embargo, el aumento del tratamiento de la harina de plumas de 50 a 100 g de NaOH/kg mejoró el comportamiento productivo y el rendimiento de cana

    Combining a Process-Based Model of Stomatal Conductance with Leaf Turgor Pressure Related Probe Measurements to Study the Regulation of Plant Water Status and Stomatal Conductance under Drought

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    The recently developed plant sensor of relative changes in leaf turgor pressure (LPCP probe) was compared with the turgor pressure output simulated with a process-based stomatal model (BMF model). Our results confirm the good agreement between the simulated turgor pressures and those derived from LPCP readings. The combined use of the BMF model and LPCP probes raised new insights into the regulation of hydraulic conductivity and osmotic pressure.Ministerio de Ciencia e Innovación español. AGL2009-11310/AGRPrograma FEDER, Comisión Europe

    Dyslipidemias and stroke prevention: recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology

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    Objetivo Actualizar las recomendaciones de la Sociedad Española de Neurología para la prevención del ictus, tanto primaria como secundaria, en pacientes con dislipidemia. Desarrollo Se ha realizado una revisión sistemática en Pubmed evaluando los principales aspectos relacionados con el manejo de las dislipidemias en la prevención primaria y secundaria del ictus, elaborándose una serie de recomendaciones relacionadas con los mismos. Conclusiones En prevención primaria se recomienda determinar el riesgo vascular del paciente con el fin de definir los objetivos de LDLc. En prevención secundaria tras un ictus de origen aterotrombótico se recomienda un objetivo de LDLc < 55 mg/dl, mientras que en ictus isquémicos de origen no aterotrombótico, dado que su relación con dislipidemias es incierta, se establecerán los objetivos en función del grupo de riesgo vascular de cada paciente. Tanto en prevención primaria como secundaria las estatinas son los fármacos de primera elección, pudiendo asociarse ezetimiba y/o inhibidores de PCSK9 en aquellos casos que no alcancen los objetivos terapéuticos.Objective We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. Development We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. Conclusions In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value < 55 mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value

    DNA Methylation-Independent Reversion of Gemcitabine Resistance by Hydralazine in Cervical Cancer Cells

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    BACKGROUND: Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in cervical cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: The cervical cancer cell line CaLo cell line was cultured in the presence of increasing concentrations of gemcitabine. Down-regulation of hENT1 & dCK genes was observed in the resistant cells (CaLoGR) which was not associated with promoter methylation. Treatment with hydralazine reversed gemcitabine resistance and led to hENT1 and dCK gene reactivation in a DNA promoter methylation-independent manner. No changes in HDAC total activity nor in H3 and H4 acetylation at these promoters were observed. ChIP analysis showed H3K9m2 at hENT1 and dCK gene promoters which correlated with hyper-expression of G9A histone methyltransferase at RNA and protein level in the resistant cells. Hydralazine inhibited G9A methyltransferase activity in vitro and depletion of the G9A gene by iRNA restored gemcitabine sensitivity. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that acquired gemcitabine resistance is associated with DNA promoter methylation-independent hENT1 and dCK gene down-regulation and hyper-expression of G9A methyltransferase. Hydralazine reverts gemcitabine resistance in cervical cancer cells via inhibition of G9A histone methyltransferase

    Evidence for classification of c.1852_1853AA>GC in MLH1 as a neutral variant for Lynch syndrome

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    Background: Lynch syndrome (LS) is an autosomal dominant inherited cancer syndrome characterized by early onset cancers of the colorectum, endometrium and other tumours. A significant proportion of DNA variants in LS patients are unclassified. Reports on the pathogenicity of the c.1852_1853AA>GC (p.Lys618Ala) variant of the MLH1 gene are conflicting. In this study, we provide new evidence indicating that this variant has no significant implications for LS. Methods: The following approach was used to assess the clinical significance of the p.Lys618Ala variant: frequency in a control population, case-control comparison, co-occurrence of the p.Lys618Ala variant with a pathogenic mutation, co-segregation with the disease and microsatellite instability in tumours from carriers of the variant. We genotyped p.Lys618Ala in 1034 individuals (373 sporadic colorectal cancer [CRC] patients, 250 index subjects from families suspected of having LS [revised Bethesda guidelines] and 411 controls). Three well-characterized LS families that fulfilled the Amsterdam II Criteria and consisted of members with the p.Lys618Ala variant were included to assess co-occurrence and co-segregation. A subset of colorectal tumour DNA samples from 17 patients carrying the p.Lys618Ala variant was screened for microsatellite instability using five mononucleotide markers. Results: Twenty-seven individuals were heterozygous for the p.Lys618Ala variant; nine had sporadic CRC (2.41%), seven were suspected of having hereditary CRC (2.8%) and 11 were controls (2.68%). There were no significant associations in the case-control and case-case studies. The p.Lys618Ala variant was co-existent with pathogenic mutations in two unrelated LS families. In one family, the allele distribution of the pathogenic and unclassified variant was in trans, in the other family the pathogenic variant was detected in the MSH6 gene and only the deleterious variant co-segregated with the disease in both families. Only two positive cases of microsatellite instability (2/17, 11.8%) were detected in tumours from p.Lys618Ala carriers, indicating that this variant does not play a role in functional inactivation of MLH1 in CRC patients. Conclusions: The p.Lys618Ala variant should be considered a neutral variant for LS. These findings have implications for the clinical management of CRC probands and their relatives.Generalitat Valenciana in Spain (AP140/08) and the Biomedical Research Foundation from the Hospital of Elche, Spain (FIBElx0902). Conselleria de Educació (Generalitat Valenciana); Fundacion Juan Peran-Pikolinos; Fundacion Carolina-BBVA and Fondo Investigación Sanitaria (FI07/00303). Instituto de Salud Carlos III (INT09/208)

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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