480 research outputs found
An annotated and illustrated checklist of Microgastrinae wasps (Hymenoptera, Braconidae) from the Canadian Arctic Archipelago and Greenland
The Microgastrinae (Hymenoptera: Braconidae) from ten islands of the Canadian
Arctic Archipelago (CAA) and Greenland were studied based on 2,183 specimens
deposited in collections. We report a total of 33 species in six genera, more
than doubling the totals previously known. Most of the species (75.7%) have a
distribution restricted to the Nearctic, with nine of those (27.3%) confirmed
to be High Arctic endemics and another 10 species considered very likely to be
High Arctic endemics as well – accounting for all of those, more than half of
all species found are endemic to the region. The most diverse genera were
Cotesia (10 species), Glyptapanteles (9 species), and Microplitis (7 species),
representing 78.8% of the overall species diversity in the region. The six
most frequently collected species comprised 84.7% of all examined specimens.
The flight period for Microgastrinae in the High Arctic encompasses only two
months, with activity peaking during the first half of July, when almost 40%
of all available specimens were collected, and then plummeting in the first
half to the end of August. Microgastrinae wasps from the High Arctic are
currently known to parasitize eight species within four families of
Lepidoptera: three species of Noctuidae, two each of Lymantridae and
Nymphalidae, and one species of Pterophoridae. However, that information is
very preliminary, as only six of the 33 species of microgastrines currently
have associated host data. An annotated checklist, including photographs for
24 of the 33 species, is provided, as well as a key to all Microgastrinae
genera present in the region
Real-time portable system for fabric defect detection using an ARM processor
Modern textile industry seeks to produce textiles as little defective as possible since the presence of defects can decrease the final price of products from 45% to 65%. Automated visual inspection (AVI) systems, based on image analysis, have become an important alternative for replacing traditional inspections methods that involve human tasks. An AVI system gives the advantage of repeatability when implemented within defined constrains, offering more objective and reliable results for particular tasks than human inspection. Costs of automated inspection systems development can be reduced using modular solutions with embedded systems, in which an important advantage is the low energy consumption. Among the possibilities for developing embedded systems, the ARM processor has been explored for acquisition, monitoring and simple signal processing tasks. In a recent approach we have explored the use of the ARM processor for defects detection by implementing the wavelet transform. However, the computation speed of the preprocessing was not yet sufficient for real time applications. In this approach we significantly improve the preprocessing speed of the algorithm, by optimizing matrix operations, such that it is adequate for a real time application. The system was tested for defect detection using different defect types. The paper is focused in giving a detailed description of the basis of the algorithm implementation, such that other algorithms may use of the ARM operations for fast implementations
Aid decision algorithms to estimate the risk in congenital heart surgery
Background and objective: In this paper, we have tested the suitability of using different artificial intelligence-based algorithms for decision support when classifying the risk of congenital heart surgery. In this sense, classification of those surgical risks provides enormous benefits as the a priori estimation of surgical outcomes depending on either the type of disease or the type of repair, and other elements that influence the final result. This preventive estimation may help to avoid future complications, or even death. Methods: We have evaluated four machine learning algorithms to achieve our objective: multilayer perceptron, self-organizing map, radial basis function networks and decision trees. The architectures implemented have the aim of classifying among three types of surgical risk: low complexity, medium complexity and high complexity. Results: Accuracy outcomes achieved range between 80% and 99%, being the multilayer perceptron method the one that offered a higher hit ratio. Conclusions: According to the results, it is feasible to develop a clinical decision support system using the evaluated algorithms. Such system would help cardiology specialists, paediatricians and surgeons to forecast the level of risk related to a congenital heart disease surgery
Larissimus nigricans sp. nov. (Hymenoptera, Braconidae), a new reared species of a rare neotropical genus recovered through biodiversity inventory in Ecuador
A new species of the rarely collected neotropical microgastrine braconid wasp genus Larissimus Nixon, represented previously by only a single described species, L. cassander Nixon, was recovered by the Caterpillars and Parasitoids of the Eastern Andes in Ecuador inventory project. Larissimus nigricans sp. nov. was reared from an unidentified species of arctiine Erebidae feeding on the common bamboo species Chusquea scandens Kunth at the Yanayacu Biological Station near Cosanga, Napo Province, Ecuador. The new species is described and diagnosed from L. cassander using both morphological and DNA barcode data
Wolbachia and DNA barcoding insects: patterns, potential and problems
Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI. Using both standard PCR assays (Wolbachia surface coding protein – wsp), and bacterial COI fragments we found evidence of Wolbachia in insect total genomic extracts created for DNA barcoding library construction. When >2 million insect COI trace files were examined on the Barcode of Life Datasystem (BOLD) Wolbachia COI was present in 0.16% of the cases. It is possible to generate Wolbachia COI using standard insect primers; however, that amplicon was never confused with the COI of the host. Wolbachia alleles recovered were predominantly Supergroup A and were broadly distributed geographically and phylogenetically. We conclude that the presence of the Wolbachia DNA in total genomic extracts made from insects is unlikely to compromise the accuracy of the DNA barcode library; in fact, the ability to query this DNA library (the database and the extracts) for endosymbionts is one of the ancillary benefits of such a large scale endeavor – for which we provide several examples. It is our conclusion that regular assays for Wolbachia presence and type can, and should, be adopted by large scale insect barcoding initiatives. While COI is one of the five multi-locus sequence typing (MLST) genes used for categorizing Wolbachia, there is limited overlap with the eukaryotic DNA barcode region
Perspectivas de los cultivos transgénicos y su aporte en la agricultura
GMOs are organisms modified by genetic engineering into which one or more genes from other species have been introduced. For example, transgenic corn that contains a gene from the bacterium Bacillus thuringiensis. GMOs are also known as genetically modified organisms (GMOs). Planting of transgenic crops began in 1994, and since then the area planted in the world with these crops has not stopped growing. According to ISAAA, some 17 million farmers plant GM crops on more than 190 million hectares, distributed in 29 countries. Among the environmental benefits offered by transgenic crops, we can mention the effects of the reduction in the use of agrochemicals (insecticides and herbicides), and economic benefits with the reduction in losses due to insect attack and weed competition, as well as to the reduction of production costs, while on the other hand there are also the disadvantages of transgenic crops that have been pointed out repeatedly. The genetic modification of food is not without controversy. On the one hand, they highlight the risks that transgenic foods may be toxic in some cases, causing allergies or other types of discomfort.Los transgénicos son organismos modificados mediante ingenierÃa genética en los que se han introducido uno o varios genes de otras especies. Por ejemplo, el maÃz transgénico que contiene un gen de la bacteria Bacillus thuringiensis. Los transgénicos también son conocidos como organismos modificados genéticamente (OMG). La siembra de cultivos transgénicos se inició en 1994, y desde ese entonces la superficie sembrada en el mundo con estos cultivos no ha parado de crecer. Según ISAAA, unos 17 millones de agricultores siembran cultivos GM en más de 190 millones de hectáreas, distribuidas en 29 paÃses. Entre los beneficios ambientales que ofrecen los cultivos transgénicos podemos mencionar los efectos de la reducción en el uso de agroquÃmicos (insecticidas y herbicidas), y beneficios económicos con la reducción en las pérdidas debidas al ataque de insectos y a la competencia de malezas, asà como a la reducción de costos de producción, mientras por otro lado también están las desventajas de los cultivos transgénicos que se han señalado repetidamente. La modificación genética de los alimentos no está exenta de controversia. Por un lado, destacan los riesgos de que los alimentos transgénicos puedan resultar tóxicos en algunos casos, provocando alergias u otro tipo de molestias
A revision of Dolichogenidea (Hymenoptera, Braconidae, Microgastrinae) with the second mediotergite broadly rectangular from Area de Conservación Guanacaste, Costa Rica
The first species of Dolichogenidea (Hymenoptera: Braconidae, Microgastrinae) with the second mediotergite broadly quadrate to rectangular are revised, and eight new species from Area de Conservación Guanacaste (ACG), Costa Rica are described, all authored by Fernandez-Triana & Boudreault: alejandromasisi, angelagonzalezae, carlosmanuelrodriguezi, genuarnunezi, josealfredohernandezi, melaniamunozae, rogerblancoi, and yeimycedenoae. A new species group (carlosmanuelrodriguezi) within the genus is proposed to accommodate those species, as well as additional undescribed species from the Neotropical region found in collections. All new species are found in rainforests (120–900 m) and all are parasitoids of Depressariidae (except for one species parasitizing Choreutidae). The unique shape of the second mediotergite and long ovipositor are features shared with the alejandromorai species group in the genus Apanteles, an example of convergent evolution; both wasp groups also parasitize similar hosts in ACG
Personalized whole-brain neural mass models reveal combined Aβ and tau hyperexcitable influences in Alzheimer’s disease
Neuronal dysfunction and cognitive deterioration in Alzheimer’s disease (AD) are likely caused by multiple pathophysiological factors. However, mechanistic evidence in humans remains scarce, requiring improved non-invasive techniques and integrative models. We introduce personalized AD computational models built on whole-brain Wilson-Cowan oscillators and incorporating resting-state functional MRI, amyloid-β (Aβ) and tau-PET from 132 individuals in the AD spectrum to evaluate the direct impact of toxic protein deposition on neuronal activity. This subject-specific approach uncovers key patho-mechanistic interactions, including synergistic Aβ and tau effects on cognitive impairment and neuronal excitability increases with disease progression. The data-derived neuronal excitability values strongly predict clinically relevant AD plasma biomarker concentrations (p-tau217, p-tau231, p-tau181, GFAP) and grey matter atrophy obtained through voxel-based morphometry. Furthermore, reconstructed EEG proxy quantities show the hallmark AD electrophysiological alterations (theta band activity enhancement and alpha reductions) which occur with Aβ-positivity and after limbic tau involvement. Microglial activation influences on neuronal activity are less definitive, potentially due to neuroimaging limitations in mapping neuroprotective vs detrimental activation phenotypes. Mechanistic brain activity models can further clarify intricate neurodegenerative processes and accelerate preventive/treatment interventions
A Poorly Known High-Latitude Parasitoid Wasp Community: Unexpected Diversity and Dramatic Changes through Time
Climate change will have profound and unanticipated effects on species distributions. The pace and nature of this change is largely unstudied, especially for the most diverse elements of terrestrial communities – the arthropods – here we have only limited knowledge concerning the taxonomy and the ecology of these groups. Because Arctic ecosystems have already experienced significant increases in temperature over the past half century, shifts in community structure may already be in progress. Here we utilise collections of a particularly hyperdiverse insect group – parasitoid wasps (Hymenoptera; Braconidae; Microgastrinae) – at Churchill, Manitoba, Canada in the early and mid-twentieth century to compare the composition of the contemporary community to that present 50–70 years ago. Morphological and DNA barcoding results revealed the presence of 79 species of microgastrine wasps in collections from Churchill, but we estimate that 20% of the local fauna awaits detection. Species composition and diversity between the two time periods differ significantly; species that were most common in historic collections were not found in contemporary collections and vice versa. Using barcodes we compared these collections to others from across North America; contemporary Churchill species are most affiliated with more south-western collections, while historic collections were more affiliated with eastern collections. The past five decades has clearly seen a dramatic change of species composition within the area studied coincident with rising temperature
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