2,496 research outputs found
A SCIENTOMETRIC REVIEW ON LEUCISM IN WILD DOLPHINS
ABSTRACTLeucism, a category of partial albinism, has been observed in several marine mammals, including cetaceans. The underlying mutations, however, have not yet been identified, and a severe knowledge gap concerning this condition in these animals, has, therefore, been noted. In this context, the present study performed a scientometric-based review on leucism in dolphins, assessing the distribution of confirmed cases worldwide. Reports ranged from 1929 to 2019, with a total of only 14 records on confirmed leucism cases obtained from the literature. This extremely low number of records confirms the significant knowledge gap for leucism in dolphins, hindering further discussions and insightsinto the ecological and physiological implications of this condition. All records report on leucistic dolphin sightings in the northern hemisphere, except for one, in southeastern Brazil. The potential causes of this condition are discussed for the investigated populations, and the role of citizen science is highlighted as a potential tool to obtain further information on the subject.RESUMOO leucismo, uma categoria de albinismo parcial, tem sido observado em vários mamíferos marinhos, incluindo cetáceos. As mutações subjacentes, no entanto, ainda não foram identificadas, e uma grave lacuna de conhecimento sobre essa condição nesses animais foi observada. Neste contexto, o presente estudo realizou uma revisão baseada em cienciometria acerca de leucismo em golfinhos, avaliando a distribuição de casos confirmados ao redor do mundo. Registros variaram de 1929 a 2019, com um total de apenas 14 registros de casos confirmados de leucismo obtidos na literatura. Este número extremamente baixo de registros confirma a significativa lacuna de conhecimento do leucismo em golfinhos, dificultando discussões e percepções adicionais sobre as implicações ecológicas e fisiológicas dessa condição. Todos os registros relatam avistamentos de golfinhos leucísticos no hemisfério norte, exceto um, no sudeste do Brasil. As causas potenciais dessa condição são discutidas para as populações investigadas, e o papel da ciência cidadã é destacado como uma ferramenta potencial para obter mais informações sobre o assunto.Palavras-chave: Albinismo; Coloração anormal; Cetáceo; Análise cienciométrica; Avistamentos de golfinhos
The population structure of Pseudomonas aeruginosa is characterized by genetic isolation of exoU+ and exoS+ lineages
The diversification of microbial populations may be driven by many factors including adaptation to distinct ecological niches and barriers to recombination. We examined the population structure of the bacterial pathogen Pseudomonas aeruginosa by analyzing whole-genome sequences of 739 isolates from diverse sources. We confirmed that the population structure of P. aeruginosa consists of two major groups (referred to as Groups A and B) and at least two minor groups (Groups C1 and C2). Evidence for frequent intra-group but limited inter-group recombination in the core genome was observed, consistent with sexual isolation of the groups. Likewise, accessory genome analysis demonstrated more gene flow within Groups A and B than between these groups, and a few accessory genomic elements were nearly specific to one or the other group. In particular, the exoS gene was highly over-represented in Group A compared to Group B isolates (99.4% vs. 1.1%) and the exoU gene was highly over-represented in Group B compared to Group A isolates (95.2% vs. 1.8%). The exoS and exoU genes encode effector proteins secreted by the P. aeruginosa type III secretion system. Together these results suggest that the major P. aeruginosa groups defined in part by the exoS and exoU genes are divergent from each other, and that these groups are genetically isolated and may be ecologically distinct. Although both groups were globally distributed and caused human infections, certain groups predominated in some clinical contexts
Global Climate Change, Food Security and the U.S. Food System
Climate change influences on the major pillars of food security. Each of the four elements of food security (availability,access,utilization,andstability) is vulnerable to changes in climate. For example,reductions in production related to regional drought influence food availability at multiple scales. Changes in price influences the ability of certain populations to purchase food (access). Utilization maybe affected when production zones shift, reducing the availability of preferred or culturally appropriate types of food within a region. Stability of the food supply may be highly uncertain given an increased incidence of extreme climatic events and their influence on production patterns
Probing Galaxy Formation with TeV Gamma Ray Absorption
We present here the extragalactic background light (EBL) predicted by
semi-analytic models of galaxy formation, and show how measurements of the
absorption of gamma rays of TeV energies via pair production on the EBL
can probe cosmology and the formation of galaxies. Semi-analytic models permit
a physical treatment of the key processes of galaxy formation -- including
gravitational collapse and merging of dark matter halos, gas cooling and
dissipation, star formation, supernova feedback and metal production -- and
have been shown to reproduce key observations at low and high redshift. Using
this approach, we investigate the consequences of variations in input
assumptions such as the stellar initial mass function and the underlying
cosmology. We conclude that observational studies of the absorption of TeV gamma rays will help to constrain the star formation
history of the universe, and the nature and extent of the extinction of
starlight due to dust and reradiation of the absorbed energy at infrared
wavelengths.Comment: 17 pages, 8 figures, presented at the VERITAS Workshop on TeV
Astrophysics of Extragalactic Sources, eds. M. Catanese and T. Weekes, to be
published in Astroparticle Physic
Bringing Molecular Tools into Environmental Resource Management: Untangling the Molecules to Policy Pathway
New advances in molecular biology can be invaluable tools in resource management, but they are best incorporated through a collaborative process with managers who understand the most pressing questions, practical limitations, and political constraints
CrossCheck:toward passive sensing and detection of mental health changes in people with schizophrenia
Early detection of mental health changes in individuals with serious mental illness is critical for effective intervention. CrossCheck is the first step towards the passive monitoring of mental health indicators in patients with schizophrenia and paves the way towards relapse prediction and early intervention. In this paper, we present initial results from an ongoing randomized control trial, where passive smartphone sensor data is collected from 21 outpatients with schizophrenia recently discharged from hospital over a period ranging from 2-8.5 months. Our results indicate that there are statistically significant associations between automatically tracked behavioral features related to sleep, mobility, conversations, smartphone usage and self-reported indicators of mental health in schizophrenia. Using these features we build inference models capable of accurately predicting aggregated scores of mental health indicators in schizophrenia with a mean error of 7.6% of the score range. Finally, we discuss results on the level of personalization that is needed to account for the known variations within people. We show that by leveraging knowledge from a population with schizophrenia, it is possible to train accurate personalized models that require fewer individual-specific data to quickly adapt to new user
ARTISANALLY LANDED ELASMOBRANCHS ALONG THE COAST OF RIO DE JANEIRO, BRAZIL
ABSTRACTConsidering the knowledge gap regarding elasmobranch species landings, this study aimed to report elasmobranch catches from artisanal fisheries to obtain baseline data in this regard. Samplings were carried out from 2016 to 2019 at three artisanal fishing colonies located in Rio de Janeiro, Tamoios, in Cabo Frio, Itaipu, in Niterói, and Copacabana, in the metropolitan rgeion of Rio de Janeiro, A trust relationship was built with the fishers, enabling ample data collection. A total of twenty-two species from twelve families were identified at all sample sites, comprising 10 sharks and 12 rays. Although Tamoios, in Cabo Frio, is home to an upwelling phenomenon, the highest richness concerning oceanic elasmobranchs was observed at Copacabana,, which is a part of Guanabara Bay, reinforcing the significant biodiversity of this bay and the importance of its recovery for elasmobranch management and conservation strategies. In addition, many specimens belonging to different species sampled at this site were juvenile, while three spinner shark females (Carcharinus brevipinna) with mature oocytes were also noted (indicating a possible strategic reproduction and juvenile settlement site for several of the landed species. The presence of many species presenting different vulnerability degrees regarding conservation and endemism, especially for the South Atlantic, reinforces the importance of this type of assessment. In addition, four keystone elasmobranch species previously observed throughout the Southeastern coast of Brazil are reported herein, , further indicating the importance of future assessments concerning elasmobranch fisheries monitoring in Brazil. In addition, artisanal fishing colonies may also act as research collaborators, as they display the potential to enable fishing strategies that allow the population, including researchers, to access a considerable portion of the elasmobranch diversity present throughout the coast of Rio de Janeiro. ResumoConsiderando a lacuna de conhecimento em relação aos desembarques de espécies de elasmobrânquios, este estudo teve como objetivo relatar as capturas de elasmobrânquios através da pesca artesanal para obter dados de base a esse respeito. As amostragens foram realizadas de 2016 a 2019 em três colônias depesca artesanal localizadas no Rio de Janeiro, Tamoios, em Cabo Frio, Itaipu, em Niterói e Copacabana, na região metropolitana do Rio de Janeiro. Um total de vinte e três espé cies de doze famílias foi identifi cado em todos os locais da amostra, incluindo 10 tubarões e 12 raias. Embora Tamoios, emCabo Frio, sofra os efeitos de um fenômeno de ressurgência, a maior riqueza relativa a elasmobrânquios oceânicas foi observada em Copacabana, que faz parte da Baía de Guanabara, reforçando a biodiversidade signifi cativa dessa baía e a importância de sua recuperação para estratégias de manejo e conservação de elasmobrânquios. Além disso, muitos espécimes pertencentes a diferentes espécies amostradas neste local eram juvenis, como tubarões martelo (Sphyrna lewini), tigre (Galeocerdo cuvier), mako Isurus oxyrinchus), seis fêmeas de cações frango (Rhizoprionodon lalandii) contendo embriões ou oocitos e três fêmeas de tubarão-rotador (Carcharinus brevipinna) com oócitos maduros, indicando um possível local estratégico de reprodução e assentamento juvenil para várias espécies desembarcadas. A presença de muitas espécies apresentando diferentes graus de vulnerabilidade em relação à conservação e endemismo, especialmente para o Atlântico Sul, reforça a importância desse tipo de avaliação. Além disso, quatro de seis espécies-chave de elasmobrânquios, ou seja, espécies que apresentam um impacto extremamente alto em um ecossistema específi co em relação à sua população e críticas para a estrutura e função gerais de um ecossistema, anteriormente observadas na costa sudeste do Brasil, são relatadas aqui, a saber Galeocerdo cuvier, Sphyrna lewini, S. zygaena e Zapteryx brevirostris, indicando ainda a importância de futuras avaliações sobre o monitoramento da pesca de elasmobrânquias no Brasil.Palavras-chave: Biodiversidade; Tubarões e raias; Pesca artesanal
WRONG WAY HOME: AN INFANT SOUTHERN ELEPHANT SEAL (MIROUNGA LEONINA) ARRIVAL ON SOUTHEASTERN BRAZILIAN BEACHES
ABSTRACTRecords of southern elephant seals (Mirounga leonina) as vagrants along the SE Brazilian coast date back the late 50’s and have been relatively common over the last decades. These large marine mammals usually call much attention when they arrive on tropical beaches worldwide and are generally treated as ‘occasional visitors’ and ‘vagrants’. This note reports on sightings of a youngelephant seal along SE Brazil in the summer and autumn of 2020. We also reviewed records in both the literature and open sources, totaling eight records of infant southern elephant seals known since the late 70’s along the Brazilian coast. It was noted that the arrival of an infant in February of 2020is coincident with a previous cyclonic activity off the SE and NE Brazilian coast. The connection of such unlikely records of pinnipeds on tropical beaches and extreme weather events associated to ocean currents should be better evaluated in the context of climatic change RESUMOÉ reportada uma ocorrência recente de um infante de elefante-marinho (Mirounga leonina) na costa do estado do Rio de Janeiro com um intervalo aproximado de um mês entre as avistagens do mesmo indivíduo. A comparação das fotografias obtidas em ambos os registros permitiu a comparação e confirmação. Em adição, se discute a presença de infantes na costa brasileira, que totalizam oito casos, mas que não apontam uma sazonalidade marcada, mas uma tendência aos registros serem reportados em junho, seguido por outubro e novembro. Como o presente registro se deu em janeiro, pico do verão, fatores climáticos de larga escala podem estar atuando para deslocar alguns indivíduos muito ao longe das suas colônias.Palavras-chave: Mirounga leonina; Movimentos; Vagante; Atlântico Sul
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