2,004 research outputs found
ARTHROPOD PREY AVAILABILITY AND BREEDING OF THE THREATENED STRANGE‐TAILED TYRANT (ALECTRURUS RISORA)
ABSTRACT ∙ The Strange‐tailed Tyrant (Alectrurus risora) is an insectivorous flycatcher (Tyrannidae) endemic to the natural tall grasslands of northern Argentina and southern Paraguay. Alectrurus risora has a polygynous mating system and the abundance of arthropods could be a major factor determining the establishment of male breeding territories and the extent of the breeding season, which is shorter than in most other reported tyrant flycatchers. To investigate this hypothesis, we examined the abundance of arthropods in upland and lowland breeding habitats. Upland habitats seem to be preferred for breeding, and usually harbour more nests. Data from one year showed that, for both grasslands, the beginning of the breeding season coincides with a greater availability of arthropods, and that the short reproductive season of A. risora coincides with a general lower availability of prey during February and March in the year we conducted the study. In upland territories, males attracted more females and had more active nests than males holding territories in lowland grasslands. However, the abundance and biomass of total arthropods and of potential prey were higher in lowland than in upland grasslands, with the exception of the abundance of Orthoptera, which was higher in upland habitat and could represent one of the major prey items. Therefore, we conclude that 1) female preference for males in upland grasslands cannot be explained by higher arthropod prey availability, and 2) the availability of arthropod prey may be important in determining the extent of the breeding season, although further, multiannual studies are required to corroborate this hypothesis. RESUMEN ∙ Disponibilidad de artrópodos presa asociados a territorios de reproducción de un ave en peligro de extinción, el Yetapá de Collar (Alectrurus risora) El Yetapá de Collar (Alectrurus risora) es un tiránido insectívoro endémico de los pastizales altos naturales del norte de Argentina y sur de Paraguay, que posee una temporada reproductiva más corta que aquella reportada para la mayoría de los tiránidos. Alectrurus risora posee un sistema de apareamiento poligínico, y la abundancia de artrópodos podría representar un factor determinante en el establecimiento de los territorios de los machos y en la duración de la temporada reproductiva. Con el fin de investigar esta hipótesis examinamos la abundancia de artrópodos en hábitats reproductivos de pastizales altos y bajos. Los pastizales altos parecen ser más utilizados durante la época reproductiva y usualmente albergan un mayor número de nidos activos. Los datos de un año de muestreo mostraron que el inicio de la temporada reproductiva coincide con el pico de abundancia de artrópodos en ambos pastizales, y que su corta duración coincide, para el área en estudio durante el año analizado, con una menor disponibilidad de presas durante los meses de febrero y marzo. En los territorios ubicados en el pastizal alto los machos atrajeron más hembras y tuvieron más nidos activos que en los territorios de pastizal bajo. Sin embargo, la abundancia y biomasa de artrópodos totales y de presas potenciales fueron mayores en el pastizal bajo, con la excepción de la abundancia de Orthoptera, que podría representar uno de los tipos principales de presa. A partir de estos resultados, concluimos que 1) la preferencia de las hembras por machos en el pastizal alto no puede ser explicada por una mayor disponibilidad de artrópodos presa, y 2) la disponibilidad de artrópodos presa podría representar un factor importante en la determinación de la extensión de la temporada reproductiva, pero se requieren estudios adicionales, plurianuales, para corroborar esta hipótesis.
New notes on the nesting of some species of Northwestern Argentina birds
We present new dat on nesting of 12 bird species of the Yungas (montane forests ) of Salta and Jujuy provinces. We provide information on date, location, size, materials and contents of the nests. The nest and eggs of Atlapetes torquatus, apparently unknown, are described. Most avian species bred in the wet season, but Amazilia chionogaster nested in the dry season
Presencia invernal de <i>Pluvianellus socialis</i> en la provincia de Buenos Aires, Argentina
First records of the Magellanic Plover (<i>Pluvianellus socialis</i>) wintering in southem Buenos Aires Province are given
New records of <i>Catamblyrhynchus diadema</i> for Northwestern Argentina
The first record of the Plushcap ( <i>Catamblyrhynchus diadema</i>) for Salta province is given based in a collected specimen. New records for Jujuy province are reported. A immature plumage is described and information about the habits is discussed by means ofthe bibliography and field notes
Stages of plumage maturation of the Tawny-bellied Seedeater: Evidence of delayed plumage maturation and cryptic differentiation between juveniles and females
In some sexually dichromatic passerines, juvenile males retain a plumage similar to that of adult females through their first year or longer (delayed plumage maturation). The Tawny-bellied Seedeater (Sporophila hypoxantha) is a sexually dichromatic species in which, to the human eye, the juveniles look like females. We analyzed the species' stages of plumage maturation by reflectance spectrometry and a visual model of color discrimination on captive individuals of known ages. We found that males retain a plumage different from that of adult males through their first breeding season. By the time males passed the age of 1 year, their color did not differ from that of adult males in any region of the body except the crown. Spectrophotometry also revealed differences between the plumage color of juvenile males and females, and the color-discrimination model implies that the birds should be able to detect these differences. Thus juvenile males of the Tawny-bellied Seedeater acquire adult plumage after their first breeding season but are already dichromatic during the first year. How this pattern of plumage development affects the species' reproductive or other social behavior deserves further study.Fil: Facchinetti, Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mahler, Bettina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Giacomo, Alejandro G.. Aves Argentinas / Asociación Ornitológica del Plata; ArgentinaFil: Reboreda, Juan Carlos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Breeding biology and conservation of the Marsh Seedeater Sporophila palustris
El Capuchino Pecho Blanco Sporophila palustris es uno de los capuchinos menos conocidos y uno de los más amenazados. Sus poblaciones reproductivas son locales, fragmentadas y ocurren en el nordeste de Argentina, sudeste de Brasil y en Uruguay. Presentamos datos reproductivos describiendo nidos y huevos, comportamiento (incluyendo cortejo, nidificación, incubación y cuidado parental), sitios de anidación y datos sobre alimentación. El Capuchino Pecho Blanco nidifica en pastizales altos y húmedos en buen estado de conservación. Estos hábitats en general se han convertido en áreas ganaderas. Las principales amenazas son sobrepastoreo, uso generalizado del fuego, drenaje de humedales, reemplazo total del hábitat por pasturas y forestaciones y captura ilegal. La mayoría de los sitios se localizan en AICAs, pero sólo uno en Brasil y otro en Argentina se encuentran protegidos. Finalmente, proponemos una serie de medidas que contribuyen a la preservación del Capuchino Pecho Blanco y de otras aves amenazadas que conviven con este.The Marsh Seedeater Sporophila palustris is one of the most endangered and least known of the capuchino seedeaters. Breeding populations are patchy, occurring in north-east Argentina,southern Brazil, and Uruguay. We present data on the breeding biology of the species, and describe nests and eggs, behaviour (including courtship, nesting, incubation and parental care), breeding sites and food items. Marsh Seedeaters breed in well-preserved grasslands with wet soils and tall vegetation. In general, these habitats are used for extensive livestock ranching. Main threats are overgrazing, widespread use of fire, conversion of grasslands to pastures of exotic grasses and rice fields, afforestation, and illegal trapping. Most breeding sites are located in Important Bird Areas, but only one in Brazil and one in Argentina are protected. We propose a series of actions to promote the conservation of Marsh Seedeaters and other endangered birds that coexist in grassland habitats.Fil: Vizentin Bugoni, Jefferson. Universidade Estadual de Campinas; Brasil;Fil: Areta, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; Argentina;Fil: Di Giacomo, Alejandro G.. Asociación Ornitológica del Plata. Aves Argentinas. Departamento de Conservación; Argentina;Fil: Di Giacomo, Adrian Santiago. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina;Fil: Jacobs, Fernando. Universidade Federal de Pelotas. Instituto de Biologia. Departamento de Zoologia e Genética; Brasil;Fil: Afonso Coimbra, Marco A.. Universidade Federal de Pelotas. Instituto de Biologia. Núcleo de Reabilitação da Fauna Silvestre e Centro de Triagem de Animais Silvestres; Brasil;Fil: Dias, Rafael A.. Universidade Católica de Pelotas. Laboratório de Biologia e Ecologia de Cordados. Setor de Ornitologia; Brasil
Long Term Running Biphasically Improves Methylglyoxal-Related Metabolism, Redox Homeostasis and Neurotrophic Support within Adult Mouse Brain Cortex
Oxidative stress and neurotrophic support decline seem to be crucially involved in brain aging. Emerging evidences indicate the pro-oxidant methylglyoxal (MG) as a key player in the age-related dicarbonyl stress and molecular damage within the central nervous system. Although exercise promotes the overproduction of reactive oxygen species, habitual exercise may retard cellular aging and reduce the age-dependent cognitive decline through hormetic adaptations, yet molecular mechanisms underlying beneficial effects of exercise are still largely unclear. In particular, whereas adaptive responses induced by exercise initiated in youth have been broadly investigated, the effects of chronic and moderate exercise begun in adult age on biochemical hallmarks of very early senescence in mammal brains have not been extensively studied. This research investigated whether a long-term, forced and moderate running initiated in adult age may affect the interplay between the redox-related profile and the oxidative-/MG-dependent molecular damage patterns in CD1 female mice cortices; as well, we investigated possible exercise-induced effects on the activity of the brain derived neurotrophic factor (BDNF)-dependent pathway. Our findings suggested that after a transient imbalance in almost all parameters investigated, the lately-initiated exercise regimen strongly reduced molecular damage profiles in brains of adult mice, by enhancing activities of the main ROS- and MG-targeting scavenging systems, as well as by preserving the BDNF-dependent signaling through the transition from adult to middle age
Uniparental markers of contemporary Italian population reveals details on its pre-Roman heritage.
BACKGROUND: According to archaeological records and historical documentation, Italy has been a melting point for populations of different geographical and ethnic matrices. Although Italy has been a favorite subject for numerous population genetic studies, genetic patterns have never been analyzed comprehensively, including uniparental and autosomal markers throughout the country.
METHODS/PRINCIPAL FINDINGS: A total of 583 individuals were sampled from across the Italian Peninsula, from ten distant (if homogeneous by language) ethnic communities--and from two linguistic isolates (Ladins, Grecani Salentini). All samples were first typed for the mitochondrial DNA (mtDNA) control region and selected coding region SNPs (mtSNPs). This data was pooled for analysis with 3,778 mtDNA control-region profiles collected from the literature. Secondly, a set of Y-chromosome SNPs and STRs were also analyzed in 479 individuals together with a panel of autosomal ancestry informative markers (AIMs) from 441 samples. The resulting genetic record reveals clines of genetic frequencies laid according to the latitude slant along continental Italy--probably generated by demographical events dating back to the Neolithic. The Ladins showed distinctive, if more recent structure. The Neolithic contribution was estimated for the Y-chromosome as 14.5% and for mtDNA as 10.5%. Y-chromosome data showed larger differentiation between North, Center and South than mtDNA. AIMs detected a minor sub-Saharan component; this is however higher than for other European non-Mediterranean populations. The same signal of sub-Saharan heritage was also evident in uniparental markers.
CONCLUSIONS/SIGNIFICANCE: Italy shows patterns of molecular variation mirroring other European countries, although some heterogeneity exists based on different analysis and molecular markers. From North to South, Italy shows clinal patterns that were most likely modulated during Neolithic times
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
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
Serological response and breakthrough infection after COVID-19 vaccination in patients with cirrhosis and post-liver transplant
BACKGROUND: Vaccine hesitancy and lack of access remain major issues in disseminating COVID-19 vaccination to liver patients globally. Factors predicting poor response to vaccination and risk of breakthrough infection are important data to target booster vaccine programs. The primary aim of the current study was to measure humoral responses to 2 doses of COVID-19 vaccine. Secondary aims included the determination of factors predicting breakthrough infection. METHODS: COVID-19 vaccination and Biomarkers in cirrhosis And post-Liver Transplantation is a prospective, multicenter, observational case-control study. Participants were recruited at 4-10 weeks following first and second vaccine doses in cirrhosis [n = 325; 94% messenger RNA (mRNA) and 6% viral vaccine], autoimmune liver disease (AILD) (n = 120; 77% mRNA and 23% viral vaccine), post-liver transplant (LT) (n = 146; 96% mRNA and 3% viral vaccine), and healthy controls (n = 51; 72% mRNA, 24% viral and 4% heterologous combination). Serological end points were measured, and data regarding breakthrough SARS-CoV-2 infection were collected. RESULTS: After adjusting by age, sex, and time of sample collection, anti-Spike IgG levels were the lowest in post-LT patients compared to cirrhosis (p < 0.0001), AILD (p < 0.0001), and control (p = 0.002). Factors predicting reduced responses included older age, Child-Turcotte-Pugh B/C, and elevated IL-6 in cirrhosis; non-mRNA vaccine in AILD; and coronary artery disease, use of mycophenolate and dysregulated B-call activating factor, and lymphotoxin-α levels in LT. Incident infection occurred in 6.6%, 10.6%, 7.4%, and 15.6% of cirrhosis, AILD, post-LT, and control, respectively. The only independent factor predicting infection in cirrhosis was low albumin level. CONCLUSIONS: LT patients present the lowest response to the SARS-CoV-2 vaccine. In cirrhosis, the reduced response is associated with older age, stage of liver disease and systemic inflammation, and breakthrough infection with low albumin level
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