17 research outputs found
Stable isotopes reveal differences in diet among reed bunting subspecies that vary in bill size
Reed bunting Emberiza schoeniclus subspecies vary considerably in bill size and shape and seem to be at an early stage of speciation, in which bill might be indirectly causing reproductive isolation. Hence, we evaluated whether bill size, as well as age and sex, are associated with foraging niche in three west European subspecies of reed bunting: the thin-billed schoeniclus, the intermediate-billed lusitanica and the thick-billed witherbyi. Blood sampling was undertaken at three sites in southwest Europe during the winter (when these subspecies co-occur), and stable isotope analyses (carbon and nitrogen) were performed to assess their foraging niches. Stable isotope analyses of potential food items confirmed uniform baseline isotopic composition among sites. schoeniclus showed a significantly broader isotopic niche than lusitanica and witherbyi, which seemed otherwise similar despite the fact that witherbyi is more divergent in bill traits. Stable isotope ratios were consistent with the latter two subspecies feeding on C3-plant-feeding insects, whereas schoeniclus diet also included C4 plant material. Despite its lower sexual dimorphism, sex and age differences were found only in schoeniclus, but these differences vary between locations in a complex manner. Our results suggest that bill size and shape differentiated between northern, migratory and southern, resident subspecies as a consequence of natural selection through competition during the winter, which is now reflected in isotopic niche divergence between subspecies. The potential roles of sexual selection, reed thickness and summer temperature on the difference in bill size (and greater sexual dimorphism) between lusitanica and witherbyi are discussed
Predicting the survival of primary biliary cholangitis patients
Data are available in a publicly accessible repository that does not issue DOIs. Publicly available datasets were analysed in this study. These data can be found here: https://www.kaggle.com/jixing475/mayo-clinic-primary-biliary-cirrhosis-data (accessed on 1 July 2022).Primary Biliary Cholangitis, which is thought to be caused by a combination of genetic and environmental factors, is a slow-growing chronic autoimmune disease in which the human body’s immune system attacks healthy cells and tissues and gradually destroys the bile ducts in the liver. A reliable diagnosis of this clinical condition, followed by appropriate intervention measures, can slow the damage to the liver and prevent further complications, especially in the early stages. Hence, the focus of this study is to compare different classification Data Mining techniques, using clinical and demographic data, in an attempt to predict whether or not a Primary Biliary Cholangitis patient will survive. Data from 418 patients with Primary Biliary Cholangitis, following the Mayo Clinic’s research between 1974 and 1984, were used to predict patient survival or non-survival using the Cross Industry Standard Process for Data Mining methodology. Different classification techniques were applied during this process, more specifically, Decision Tree, Random Tree, Random Forest, and Naïve Bayes. The model with the best performance used the Random Forest classifier and Split Validation with a ratio of 0.8, yielding values greater than 93% in all evaluation metrics. With further testing, this model may provide benefits in terms of medical decision support.This work is funded by “Fundação para a Ciência e Tecnologia (FCT)” within the R&D Units Project Scope: UIDB/00319/2020
UMA PROPOSTA DE AVALIAÇÃO DO DESEMPENHO NA LOGÍSTICA INTERNACIONAL
O presente artigo demonstra os resultados de uma pesquisa teórica desenvolvida sobre Avaliação de Desempenho Logístico - ADL, especificamente na área de Logística Internacional. Objetivou-se verificar o que se tem publicado de pesquisa científica na área específica, identificar os pontos chave da cadeia logística de uma operação internacional e propor um método para avaliar o desempenho de uma logística internacional. Realizou-se uma pesquisa qualitativa, de caráter descritivo, sendo adotado um estudo bibliométrico. Identificada a cadeia logística internacional e apontados os pontos chave para avaliação de desempenho foi possível propor um sistema de avaliação de desempenho com base na LPI – Logistc Performance Indicator criada pelo Banco Mundial. Além disso, ilustrou-se a proposta do sistema com uma simulação hipotética de avaliação. Pode-se concluir que ainda é incipiente a pesquisa científica sobre ADL na logística internacional e espera-se, com a pesquisa realizada, contribuir no sentido de instigar as discussões sobre o tema.Palavras-Chave: Avaliação; Desempenho; Logística Internaciona
Movements and social behavior of killer whales (Orcinus orca) off the Brazilian coast
Killer whales (Orcinus orca) are cosmopolitan apex predators that occupy important ecological roles and show some variations in feeding and social habits in coastal and pelagic environments worldwide. Although they have been regularly reported along the Brazilian coastline, their natural history in these tropical and subtropical waters remains poorly understood. Here, we provide new information on group size, behavior, movements and the first assessment of their social structure in Brazilian coast. From 2005 to 2021, 57 new records of sightings were opportunistically observed with estimated group sizes ranging from 1 to 11 individuals (mean = 5.61; SD = 2.91), and 47 individuals were photo-identified—28% adult females, 19% adult males, 19% juveniles, 17% calves and 17% adults of unknown sex. Thirty-one individuals (66%) were sighted just once and sixteen (34%) were resighted more than once (resighting rate = 0.30 ± 0.30 SD). Killer whales were observed feeding on rays four times (two out of which on butterfly rays Gymnura altavela), twice on an unidentified fish school of fish, while attacks on marine mammals were recorded. Between 2020 and 2021, photo-identification results of 11 specific individuals revealed both long and short-distance movements from the southeastern and southern Brazilian coasts to the coast of Uruguay. Individuals seem to be resighted together over time, as suggested by the average half-weight association index (HWI = 0.29 ± 0.19 SD) and a permutation test rejecting the null hypothesis of random association (CVreal = 0.67 > CVmean = 0.01, pCV = 1.00), forming small groups of mixed age-sex that engage in both short- and long-term associations. These patterns suggest that they could form stable social units that also experience some degree of fission-fusion dynamics. While the nature of the opportunistic data hinders a definitive portrayal of the social structure of killer whales using the Brazilian coastal waters, these novel insights contribute to mapping the socio-ecology and behavioral diversity of one of the most widely distributed mammals
Sistema de evaluación institucional en enseñanza obligatoria en Iberoamérica
La presente aportación se focaliza, en este contexto, en la evaluación institucional externa (vinculada o no a la autoevaluación interna) y, por tanto, considera prioritariamente la manera como se evalúan los centros educativos como totalidad y no tanto alguno de sus aspectos (evaluación de la dirección, de los profesores, de los programas, etc.), que también pueden estar considerados. El énfasis también está en conocer la organización y desarrollo del sistema de evaluación. Recoge la visión de 43 especialistas de trece países iberoamericanos sobre las formas de entender y promover la evaluación institucional en sus centros educativos. Sus aportaciones, que deben contextualizarse en las particularidades educativas de sus países (ya presentadas en anteriores informes de la RedAGE), presentan los aspectos generales y normativos de la evaluación, las formas cómo se organiza, los efectos institucionales que tienen y algunas reflexiones, retos y propuestas para la mejora. Su orientación es claramente práctica y se vincula al encuentro anual que la RedAGE realizado los días 16 y 17 de mayo de 2016 en la ciudad de Leiria (Portugal). Allí, los representantes de las organizaciones miembro seleccionaron la temática por su interés actual (con clara vinculación a la mejora de los sistemas educativos y la acreditación institucional), consensuaron la estructura de las aportaciones y realizaron un intercambio de posibles ideas sobre la temática. Se cubre así y como en ocasiones anteriores el propósito fundamental de la RedAGE, como es el de fomentar el intercambio de experiencias, la promoción del conocimiento sobre administración y gestión educativa y la reflexión sobre la práctica de la gestión. La finalidad última sigue siendo la de mejorar el funcionamiento de los centros educativos (y, a través de ellos, de los sistemas educativos), procurando sean de calidad y un instrumento para el cambio profesional y social
Os passeriformes paludícolas do caniçal de Salreu, Ria de Aveiro: dinâmica anual, distribuição vertical, impacto do corte de vegetação e migração
Este estudo foi realizado no caniça1 de Salreu, Ria de Aveiro, onde durante 13 meses se
capturaram aves, particularmente passeriformes paludícolas, regularmente e em esforço
constante. Também se efectuaram censos em pontos de contagem distribuídos por diversos
habitats constituídos por Caniço cortado em diferentes datas.
Verificou-se que neste local a riqueza específica, abundância e diversidade eram
superiores de Abril a Outubro, período corrrespondente a época de nidificação e migração
pós-nupcial. A espécie mais comum foi Acrocephalus scirpaceus, sendo também abundantes
no local as outras espécies de passeriformes paludícolas nidificantes em Portugal, a excepção
de Acrocephalus arundinaceus, que é pouco comum. Ocorrem ainda várias espécies
paludícolas migradoras de passagem, descrevendo-se a variação dos seus efectivos durante o
ano. Existem localmente poucas espécies de passeriformes residentes, que foram praticamente
as únicas a ser capturadas durante o Inverno. [...]This study was carried out in Salreu, Estarreja, in Northwestern Portugal, and involved
the use of constant effort mist-netting to capture passerines in reedbeds during 13 months.
Point-counts located in several habitats with reeds cutted in different years were also used.
The species richeness, abundance and diversity were higher during the breeding and
migration seasons. The most common species was the Reed Warbler, Acrocephalus
scirpaceus, but the other reedbed's breeding passerines that occur in Portugal were also
common except the Great Reed Warbler, Acrocephalus arundinaceus, which was uncommon.
Exclusively migratory species were captured, such as: Sedge Warbler, Acrocephalus
schoenobaenus, Grasshopper Warbler, Locustella naevia, and Bluethroat, Luscinia svecica,
and their annual dynamics described. During Winter only the few resident species were present.[...]Mestrado em Zonas Costeira
Seasonal dynamics of haemosporidian (Apicomplexa, Haemosporida) parasites in house sparrows Passer domesticus at four European sites : comparison between lineages and the importance of screening methods
Infectious diseases often vary seasonally in a predictable manner, and seasonality may be responsible for geographical differences in prevalence. In temperate regions, vector-borne parasites such as malaria are expected to evolve lower virulence and a time-varying strategy to invest more in transmission when vectors are available. A previous model of seasonal variation of avian malaria described a double peak in prevalence of Plasmodium parasites in multiple hosts resulting from spring relapses and transmission to susceptible individuals in summer. However, this model was rejected by a study describing different patterns of seasonal variation of two Plasmodium spp. at the same site, with the double peak only apparent when these species were combined. Here, we assessed the seasonal variation in prevalence of haemosporidian parasites (Plasmodium, Haemoproteus and Leucocytozoon) in house sparrows (Passer domesticus) sampled across 1 year at four temperate European sites spanning a latitudinal range of 17°. We showed that parasite prevalence and diversity decreased with increasing latitude, but the parasite communities differed between sites, with only one Plasmodium lineage (P_SGS1) occurring at all sites. Moreover, the nested PCR method commonly used to detect and identify haemosporidian parasites strongly underestimated co-infections of Haemoproteus and Plasmodium, significantly biasing the pattern of seasonal variation, so additional molecular methods were used. Finally, we showed that: (i) seasonal variation in prevalence of haemosporidian parasites varied between study sites and parasite lineages/species/genera, describing further cases where the double peak model is not met; (ii) the seasonal dynamics of single lineages (P_SGS1) varied between sites; and (iii) unexpectedly, seasonality was greatest at the southernmost site, a pattern that was mostly driven by lineage H_PADOM05. Limitations of the genotyping methods and consequences of pooling (parasite lineages, sites and years) in studies of haemosporidian parasites are discussed and recommendations proposed, since these actions may obscure the patterns of prevalence and limit ecological inferences