59 research outputs found

    Hybridization and hybrid speciation under global change

    Get PDF
    An unintended consequence of global change is an increase in opportunities for hybridization among previously isolated lineages. Here we illustrate how global change can facilitate the breakdown of reproductive barriers and the formation of hybrids, drawing on the flora of the British Isles for insight. Although global change may ameliorate some of the barriers preventing hybrid establishment, for example by providing new ecological niches for hybrids, it will have limited effects on environment-independent post-zygotic barriers. For example, genic incompatibilities and differences in chromosome numbers and structure within hybrid genomes are unlikely to be affected by global change. We thus speculate that global change will have a larger effect on eroding pre-zygotic barriers (eco-geographical isolation and phenology) than post-zygotic barriers, shifting the relative importance of these two classes of reproductive barriers from what is usually seen in naturally produced hybrids where pre-zygotic barriers are the largest contributors to reproductive isolation. Although the long-term fate of neo-hybrids is still to be determined, the massive impact of global change on the dynamics and distribution of biodiversity generates an unprecedented opportunity to study large numbers of unpredicted, and often replicated, hybridization ‘experiments’, allowing us to peer into the birth and death of evolutionary lineages

    Elevation and habitats: the potential of sites at different altitudes to provide refuges for phytophagous insects during climatic fluctuations

    No full text
    Uplands are expected to provide refuges for species subject to lowland habitat loss and projected climate changes. Here, we argue that upland populations also provide refuges when lowland sites are subject to climatic fluctuations and extreme events and that species with populations dispersed over adjoining uplands and lowlands spread their risk of extinction. A proviso is that development is sufficiently lagged with altitude but that development rates are compatible. Emergence patterns and development of the butterfly Anthocharis cardamines and its larval host plant Cardamine pratensis show these characteristics, and coupled with the butterfly’s capacity to migrate between isolated populations present a case where upland and lowland populations can act as sources when one or the other area is adversely affected by extreme events

    ARTIFICIAL INTELLIGENCE APPROACH TO CLASSIFY UNIPOLAR and BIPOLAR DEPRESSIVE DISORDERS

    No full text
    Machine learning (ML) approaches for medical decision making processes are valuable when both high classification accuracy and less feature requirements are satisfied. Artificial neural networks (ANNs) successfully meet the first goal with its adaptive engine while nature inspired algorithms are focusing on the feature selection (FS) process in order to eliminate less informative and less discriminant features. Besides engineering applications of ANN and FS algorithms, medical informatics is another emerging field using similar methods for medical data processing. Classification of psychiatric disorders is one of major focus of medical informatics using artificial intelligence approaches. Being one of the most debilitating psychiatric diseases, bipolar disorder (BD) is frequently misdiagnosed as unipolar disorder (UD), leading to suboptimal treatment and poor outcomes. Thus, discriminating UD and BD at earlier stages of illness could therefore help to facilitate efficient and specific treatment. The use of quantitative electroencephalography (EEG) cordance as a biomarker has greatly enhanced the clinical utility of EEG in psychiatric and neurological subjects. In this context, the paper puts forward a study using two-step hybridized methodology, particle swarm optimization (PSO) algorithm for feature selection process and ANN for training process. The noteworthy performance of ANN-PSO approach stated that it is possible to discriminate 31 bipolar and 58 unipolar subjects using selected features from alpha and theta frequency bands with 89.89% overall classification accurac

    Violência contra a criança: indicadores dermatológicos e diagnósticos diferenciais Child abuse: skin markers and differential diagnosis

    Get PDF
    As denúncias de abuso contra a criança têm sido frequentes e configuram grave problema de saúde pública. O tema é desconfortável para muitos médicos, seja pelo treinamento insuficiente, seja pelo desconhecimento das dimensões do problema. Uma das formas mais comuns de violência contra a criança é o abuso físico. Como órgão mais exposto e extenso, a pele é o alvo mais sujeito aos maustratos. Equimoses e queimaduras são os sinais mais visíveis. Médicos (pediatras, clínicos-gerais e dermatologistas) costumam ser os primeiros profissionais a observar e reconhecer sinais de lesões não acidentais ou intencionais. Os dermatologistas podem auxiliar na distinção entre lesões traumáticas intencionais, acidentais e doenças cutâneas que mimetizam maus-tratos<br>Reports of child abuse have increased significantly. The matter makes most physicians uncomfortable for two reasons: a) Little guidance or no training in recognizing the problem; b - Not understanding its true dimension. The most common form of child violence is physical abuse. The skin is the largest and frequently the most traumatized organ. Bruises and burns are the most visible signs. Physicians (pediatricians, general practitioners and dermatologists) are the first professionals to observe and recognize the signs of intentional injury. Dermatologists particularly, can help distinguish intentional injury from accidental, or from skin diseases that mimic maltreatmen
    corecore