Background optimization of powder electron diffraction for implementation of the e-PDF technique and study of the local structure of iron oxide nanocrystals.

The local structural characterization of iron oxide nanoparticles is explored using a total scattering analysis method known as pair distribution function (PDF) (also known as reduced density function) analysis. The PDF profiles are derived from background-corrected powder electron diffraction patterns (the e-PDF technique). Due to the strong Coulombic interaction between the electron beam and the sample, electron diffraction generally leads to multiple scattering, causing redistribution of intensities towards higher scattering angles and an increased background in the diffraction profile. In addition to this, the electron-specimen interaction gives rise to an undesirable inelastic scattering signal that contributes primarily to the background. The present work demonstrates the efficacy of a pre-treatment of the underlying complex background function, which is a combination of both incoherent multiple and inelastic scatterings that cannot be identical for different electron beam energies. Therefore, two different background subtraction approaches are proposed for the electron diffraction patterns acquired at 80 kV and 300 kV beam energies. From the least-square refinement (small-box modelling), both approaches are found to be very promising, leading to a successful implementation of the e-PDF technique to study the local structure of the considered nanomaterial.

Higher-Order Cumulants Drive Neuronal Activity Patterns, Inducing UP-DOWN States in Neural Populations.

A major challenge in neuroscience is to understand the role of the higher-order correlations structure of neuronal populations. The dichotomized Gaussian model (DG) generates spike trains by means of thresholding a multivariate Gaussian random variable. The DG inputs are Gaussian distributed, and thus have no interactions beyond the second order in their inputs; however, they can induce higher-order correlations in the outputs. We propose a combination of analytical and numerical techniques to estimate higher-order, above the second, cumulants of the firing probability distributions. Our findings show that a large amount of pairwise interactions in the inputs can induce the system into two possible regimes, one with low activity ("DOWN state") and another one with high activity ("UP state"), and the appearance of these states is due to a combination between the third- and fourth-order cumulant. This could be part of a mechanism that would help the neural code to upgrade specific information about the stimuli, motivating us to examine the behavior of the critical fluctuations through the Binder cumulant close to the critical point. We show, using the Binder cumulant, that higher-order correlations in the outputs generate a critical neural system that portrays a second-order phase transition.

Coupling Neuropeptide Levels to Structural Plasticity in Drosophila Clock Neurons.

We have previously reported that pigment dispersing factor (PDF) neurons, which are essential in the control of rest-activity cycles in Drosophila, undergo circadian remodeling of their axonal projections, a phenomenon called circadian structural plasticity. Axonal arborizations display higher complexity during the day and become simpler at night, and this remodeling involves changes in the degree of connectivity. This phenomenon depends on the clock present within the ventrolateral neurons (LNvs) as well as in glia. In this work, we characterize in detail the contribution of the PDF neuropeptide to structural plasticity at different times across the day. Using diverse genetic strategies to temporally restrict its downregulation, we demonstrate that even subtle alterations to PDF cycling at the dorsal protocerebrum correlate with impaired remodeling, underscoring its relevance for the characteristic morning spread; PDF released from the small LNvs (sLNvs) and the large LNvs (lLNvs) contribute to the process. Moreover, forced depolarization recruits activity-dependent mechanisms to mediate growth only at night, overcoming the restriction imposed by the clock on membrane excitability. Interestingly, the active process of terminal remodeling requires PDF receptor (PDFR) signaling acting locally through the cyclic-nucleotide-gated channel ion channel subunit A (CNGA). Thus, clock-dependent PDF signaling shapes the connectivity of these essential clock neurons on daily basis.

Low-Temperature Carbon Dioxide Gas Sensor Based on Yolk-Shell Ceria Nanospheres.

Monitoring carbon dioxide (CO2) levels is extremely important in a wide range of applications. Although metal oxide-based chemoresistive sensors have emerged as a promising approach for CO2 detection, the development of efficient CO2 sensors at low temperature remains a challenge. Herein, we report a low-temperature hollow nanostructured CeO2-based sensor for CO2 detection. We monitor the changes in the electrical resistance after CO2 pulses in a relative humidity of 70% and show the high performance of the sensor at 100 °C. The yolk-shell nanospheres have not only 2 times higher sensitivity but also significantly increased stability and reversibility, faster response times, and greater CO2 adsorption capacity than commercial ceria nanoparticles. The improvements in the CO2 sensing performance are attributed to hollow and porous structure of the yolk-shell nanoparticles, allowing for enhanced gas diffusion and high specific surface area. We present an easy strategy to enhance the electrical and sensing properties of metal oxides at a low operating temperature that is desirable for practical applications of CO2 sensors.

Abordagem clínico e cirúrgico da fixação dorsal de patela em equinos - relato de caso

A fixação dorsal de patela (FDP) é uma das afecções que mais acometem a articulação femoro tíbio patelar dos equinos, esta é caracterizada pela hiperextensão do membro pélvico, podendo acometer uni ou bilateral, tem diversas etiologias e pré-disposições, sendo as mais comuns a falta de tônus muscular e aprumos irregulares, os tratamentos são escolhidos de acordo com o grau da lesão, podendo ser estes com fisioterapia, contrairritantes e desmotomia associados ou não. Relata-se neste trabalho um animal atendido pelo hospital veterinário de grandes animais da FAEF, sendo necessário o uso de diferentes tratamentos para a solução do caso.(AU)

Dorsal patellar fixation (PDF) is one of the affections that most affect the patellofemoral articulation of horses, which is characterized by hyperextension of the pelvic limb, which can be uni or bilateral, has several etiologies and pre-dispositions, being the most common lack of muscle tone and irregular, the treatments are chosen according to the degree of the injury, being these with physiotherapy, contrairritantes and desmotomy associated or not. This work reports an animal attended by the veterinary hospital of large animals of the FAEF, where it was necessary to use different treatments for the solution of the case.(AU)

Abordagem clínico e cirúrgico da fixação dorsal de patela em equinos - relato de caso

A fixação dorsal de patela (FDP) é uma das afecções que mais acometem a articulação femoro tíbio patelar dos equinos, esta é caracterizada pela hiperextensão do membro pélvico, podendo acometer uni ou bilateral, tem diversas etiologias e pré-disposições, sendo as mais comuns a falta de tônus muscular e aprumos irregulares, os tratamentos são escolhidos de acordo com o grau da lesão, podendo ser estes com fisioterapia, contrairritantes e desmotomia associados ou não. Relata-se neste trabalho um animal atendido pelo hospital veterinário de grandes animais da FAEF, sendo necessário o uso de diferentes tratamentos para a solução do caso.

Dorsal patellar fixation (PDF) is one of the affections that most affect the patellofemoral articulation of horses, which is characterized by hyperextension of the pelvic limb, which can be uni or bilateral, has several etiologies and pre-dispositions, being the most common lack of muscle tone and irregular, the treatments are chosen according to the degree of the injury, being these with physiotherapy, contrairritantes and desmotomy associated or not. This work reports an animal attended by the veterinary hospital of large animals of the FAEF, where it was necessary to use different treatments for the solution of the case.

A new genus and four new species of dactylogyrids (Monogenea), gill parasites of pimelodid catfishes (Siluriformes: Pimelodidae) in South America and the reassignment of Urocleidoides megorchis Mizelle et Kritsky, 1969.

Nanayella gen. n. is proposed to accommodate four new species of dactylogyrid monogeneans found on the gills of two species of pimelodid catfishes (Siluriformes) from the Amazon River basin in Peru and the Upper Paraná River basin in Brazil. Nanayella gen. n. is mainly characterised by the presence of modified hook pairs 5 and 6, which have a slender shank with slightly enlarged base, inconspicuous thumb, and straight point. Nanayella aculeatrium gen. n. et sp. n. (type species) from Sorubim lima (Bloch et Schneider) (type host) differs from its congeners mainly by possessing seven sclerotised spines on one side of circular ornamentation of the vaginal atrium. Nanayella fluctuatrium gen. n. et sp. n. is characterised by the presence of sclerotised undulations surrounding the circular ornamentation of the vaginal atrium. Nanayella amplofalcis gen. n. et sp. n. is typified by possessing hook pairs 1 and 2 with a robust, wide shank and a round, weakly sclerotised subunit at the base. Nanayella processusclavis gen. n. et sp. n. differs from congeners by the presence of a conspicuous posterior medial process on the dorsal bar. Urocleidoides megorchis Mizelle et Kritsky, 1969 described from the gills of S. lima in Brazil is transferred to Nanayella gen. n. as Nanayella megorchis comb. n. based on morphological and molecular evidence. Analyses of partial sequences of the 28S rRNA gene revealed all five species of the new genus to form a monophyletic clade within a bigger clade comprised of dactylogyrids of South American pimelodids.

Pigment-dispersing factor signaling in the circadian system of Caenorhabditis elegans.

The neuropeptide pigment-dispersing factor (PDF) is important for the generation and entrainment of circadian rhythms in the fruitfly Drosophila melanogaster. Recently two pdf homologs, pdf-1 and pdf-2, and a PDF receptor, pdfr-1, have been found in Caenorhabditis elegans and have been implicated in locomotor activity. In this work, we have studied the role of the PDF neuropeptide in the circadian system of C. elegans and found that both pdf-1 and pdf-2 mutants affect the normal locomotor activity outputs. In particular, loss of pdf-1 induced circadian arrhythmicity under both light-dark (LD) and constant dark (DD) conditions. These defects can be rescued by a genomic copy of the pdf-1 locus. Our results indicate that PDF-1 is involved in rhythm generation and in the synchronization to LD cycles, as rhythmic patterns of activity rapidly disappear when pdf-1 mutants are recorded under both entrained and free-running conditions. The role of PDF-2 and the PDF receptors is probably more complex and involves the interaction between the two pdf paralogues found in the nematode.

The circadian system: plasticity at many levels.

Over the years it has become crystal clear that a variety of processes encode time-of-day information, ranging from gene expression, protein stability, or subcellular localization of key proteins, to the fine tuning of network properties and modulation of input signals, ultimately ensuring that physiology and behavior are properly synchronized to a changing environment. The purpose of this review is to put forward examples (as opposed to generate a comprehensive revision of all the available literature) in which the circadian system displays a remarkable degree of plasticity, from cell autonomous to circuit-based levels. In the literature, the term circadian plasticity has been used to refer to different concepts. The obvious one, more literally, refers to any change that follows a circadian (circa=around, diem=day) pattern, i.e. a daily change of a given parameter. The discovery of daily remodeling of neuronal structures will be referred herein as structural circadian plasticity, and represents an additional and novel phenomenon modified daily. Finally, any plasticity that has to do with a circadian parameter would represent a type of circadian plasticity; as an example, adjustments that allow organisms to adapt their daily behavior to the annual changes in photoperiod is a form of circadian plasticity at a higher organizational level, which is an emergent property of the whole circadian system. Throughout this work we will revisit these types of changes by reviewing recent literature delving around circadian control of clock outputs, from the most immediate ones within pacemaker neurons to the circadian modulation of rest-activity cycles.

Creación y personalización de una colección de documentos digitales basada en Greenstone (Parte 2) / Creating and personalizing digital documents collections in Greenstone (Part 2)

La presentación y organización de las colecciones construidas con el sistema Greenstone están dotadas de una notable flexibilidad que confiere un valor añadido al acceso a la información según los intereses, características y necesidades de los usuarios finales. En el artículo Creación y personalización de una colección de documentos digitales basada en Greenstone, se describió el diseño personalizado de una colección compuesta de archivos .doc y .pdf en lo relativo a mecanismos de búsqueda y navegación, por una parte, y cambios en algunos elementos de su página Acerca de, por la otra, los cuales se lograron a partir de disímiles cadenas de formatos correspondientes a los clasificadores y la macro extra.dm. Con el fin de profundizar en la familiarización de las ventajas de este sistema y ampliar el abanico de posibilidades que ofrece, en la segunda parte de este trabajo, se dio continuidad a la personalización de una colección similar sobre la base de la aplicación de otras cadenas de formato que operan modificaciones inmediatas en la disposición de los datos así como en la apariencia y organización de la información contenida en las diferentes páginas generadas por este sistema. Tal conjunto de posibles personalizaciones ilustra, en alguna medida, las alternativas de configuración de las salidas de esta aplicación las cuales, además, se ejecutan en forma expedita(AU)

The presentation and organization of collections built with Greenstone system are endowed with a remarkable flexibility adds value to information access in the interests, characteristics and needs of end users. Article Creation and customization of a collection of digital documents based on Greenstone, described the custom design consisting of a collection of files. Doc and. Pdf with regard to navigation and search mechanisms on the one hand, and changes in some elements of their About page, on the other, which were obtained from dissimilar formats for strings and macro classifiers extra.dm. To deepen the familiarity of the advantages of this system and expand the range of possibilities offered in the second part of this work, we continued to customizing a similar collection on the basis of the application of other format chains operating immediate changes in the provision of data as well as the appearance and organization of the information contained on the pages generated by this system. Such a set of possible customizations illustrates, to some extent, the alternative configuration of the outputs of this application which also run in an expeditious manner(AU)

Padronização de dosagem de produto de degradação fibrinogênio/fibrina humano / Human fibrin/fibrinogen degradation product dosage standardization

A hemostasia contribui para integridade e fluidez sanguinea. Após ativação de plaquetas, fatores da coagulação e células endoteliais ocorrem reações enzimáticas gerando trombina e fibrina, principal constituinte do trombo. A plasmina remove o coágulo degradando a fibrina em produtos solúveis (sistema fibrinolítico) e fragmentados (Produtos de Degradação da Fibrina - PDF) onde o Dímero D é o mais estável. Por isso torna-se um importante indicador do risco vascular. Realizaram-se 2 protocolos: LAMB F (Fibrinogênio) e Lamb D (Fragmentado D) produzindo 2786 hibridos com atividade anti PDF. Os hibridos selecionados foram submetidos à técnica de immunoblotting onde foram utilizadas as fontes de antigenos diferentes (Fib comercial, Fib purificado in house, Fragmento D, líquido de drenagem rico em PDF. Com base no reconhecimento das frações protéicas, selecionou-se 2 híbridos (LAMB F1 - 120 e LAMB D3-6), que foram clonados e expandidos em cultura (in vitro) e ascite (in vivo) para obtenção de altas concentrações de AcMm. O líquido ascítico foi purificado (coluna de afinidade)e os anticorpos acoplados em esferas (beads) de agarose. Testes qualitativos foram realizados em paralelo com o produto comercial (Dimer Test Dade Behring) utilizando 20 amostras de pacientes (15 PDF normal e 05 PDF alterado). Os resultados mostraram 100% de concordância entre o produto comercial e os anticorpos anti-PDF produzido no laboratório.