2,804 research outputs found
Convolution kernels versus spectral multipliers for sub-Laplacians on groups of polynomial growth
Let be a sub-Laplacian on a connected Lie group of
polynomial growth. It is well known that, if is
in the Schwartz class , then the convolution kernel
of the operator is in the
Schwartz class . Here we prove a sort of converse implication
for a class of groups including all solvable noncompact groups of
polynomial growth. We also discuss the problem whether integrability of
implies continuity of .Comment: 27 page
Biological Random Walks: multi-omics integration for disease gene prioritization
Motivation: Over the past decade, network-based approaches have proven useful
in identifying disease modules within the human interactome, often providing
insights into key mechanisms and guiding the quest for therapeutic targets.
This is all the more important, since experimental investigation of potential
gene candidates is an expensive task, thus not always a feasible option. On the
other hand, many sources of biological information exist beyond the interactome
and an important research direction is the design of effective techniques for
their integration. Results: In this work, we introduce the Biological Random
Walks (BRW) approach for disease gene prioritization in the human interactome.
The proposed framework leverages multiple biological sources within an
integrated framework. We perform an extensive, comparative study of BRW's
performance against well-established baselines. Availability and
implementation: All code is publicly available and can be downloaded at
\url{https://github.com/LeoM93/BiologicalRandomWalks}. We used publicly
available datasets, details on their retrieval and preprocessing are provided
in the supplementary material
Cactaceae no Parque Estadual de Itapuã, Rio Grande do Sul, Brasil
Foi realizado o levantamento das espécies da família Cactaceae no Parque Estadual de Itapuã. A família está representada na área 14 por 6 gêneros e 8 espécies: Cereus hildmannianus, Frailea gracillima, Lepismium cruciforme, Lepismium warmingianum, Opuntia aff. arechavaletae, Parodia langsdorfii, P. ottonis e Rhipsalis teres. Três espécies estão ameçadas de extinção. As espécies estão distribuídas em áreas de restinga, campos rupestres com afloramentos rochosos e nas matas nas encostas dos morros. Fornecemos uma chave para identificação, dados morfológicos, área de ocorrência no Parque, ilustrações e comentários taxonômicos e ecológicos para as espécies.A survey of the cacti species in the Itapuã State Park is presented. The Cactaceae is represented in the 14 area by 6 genera and 8 species: Cereus hildmannianus, Frailea gracillima, Lepismium cruciforme, Lepismium warmingianum, Opuntia aff. arechavaletae, Parodia langsdorfii, P. ottonis and Rhipsalis teres. Three species are threatened with extinction. The species are distributed in areas of restinga, rocky outcrops and in the forests on the hillsides. We provide a key for identification, morphological data, area of occurrence in the Park, illustrations, taxonomic, and ecological comments for the species
A cláusula perfil no contrato de seguro de automóveis
As injustiça sociais perpetradas pela concepção liberal de mundo provocaram a derrocada da concepção tradicional do contrato. Instaurou-se uma nova ordem contratual, acompanhada do surgimento de novos princípios contendores da outrora irrestrita autonomia da vontade e autorizadores da intervenção estatal no domínio económico para a proteção do contratante mais frágil. Essa nova ordem ganhou destaque no Código de Defesa do Consumidor, o qual prevê a possibilidade de controle, pelo Poder Judiciário, das cláusulas que provocam desequilíbrio contratual. Nesse contexto, têm sido cada vez mais frequente a declaração de nulidade da cláusula perfil existente nos contratos de seguro de automóveis e a compreensão restritiva do que seja "agravação do risco", sempre com o escopo de proteger o segurado-consumidor. Entretanto, tendo-se em vista as necessidades de observar-se o princípio do mutualismo, de manter-se a dependência estreita entre o risco e o prémio e de fazer com que o prémio pago por cada segurado seja proporcional aos riscos que atingem seu interesse, a cláusula perfil não pode ser considerada uma cláusula abusiva porque ela não limita direitos instituídos pelo contrato para o segurado, mas apenas restringe previamente os riscos assumidos pelo segurador. Sua inclusão no contrato de seguro de automóveis é necessária e possível, desde que seja redigida com as cautelas exigidas pela lei consumerista e desde que sejam feitos ao segurado os esclarecimentos pertinentes
3D printable device for automated operant conditioning in the mouse
Operant conditioning is a classical paradigm and a standard technique used in experimental psychology in which animals learn to perform an action in order to achieve a reward. By using this paradigm, it is possible to extract learning curves and measure accurately reaction times. Both these measurements are proxy of cognitive capabilities and can be used to evaluate the effectiveness of therapeutic interventions in mouse models of disease. Here we describe a fully 3D printable device that is able to perform operant conditioning on freely moving mice, while performing real-time tracking of the animal position. We successfully trained 6 mice, showing stereotyped learning curves that are highly reproducible across mice and reaching more than 70% of accuracy after two days of conditioning. Different products for operant conditioning are commercially available, though most of them do not provide customizable features and are relatively expensive. This data demonstrate that this system is a valuable alternative to available state-of-the-art commercial devices, representing a good balance between performance, cost, and versatility in its use.Significance Statement 3D printing is a revolutionary technology that combines cost-effectiveness with an optimal trade off between standardization and customization. Here we show a device that performs operant conditioning in mice using largely 3D printed parts. This tool can be employed to test learning and memory in models of disease. We expect that the open design of the chamber will be useful for scientific teaching and research as well as for further improvements from the open hardware community
Structure-dependent electrical properties of graphene nanoribbon devices with graphene electrodes
Graphene nanoribbons (GNRs) are a novel and intriguing class of materials in
the field of nanoelectronics, since their properties, solely defined by their
width and edge type, are controllable with high precision directly from
synthesis. Here we study the correlation between the GNR structure and the
corresponding device electrical properties. We investigated a series of field
effect devices consisting of a film of armchair GNRs with different structures
(namely width and/or length) as the transistor channel, contacted with narrowly
spaced graphene sheets as the source-drain electrodes. By analyzing several
tens of junctions for each individual GNR type, we observe that the values of
the output current display a width-dependent behavior, indicating electronic
bandgaps in good agreement with the predicted theoretical values. These results
provide insights into the link between the ribbon structure and the device
properties, which are fundamental for the development of GNR-based electronics.Comment: Published in Carbon (2019
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