Mechanisms of rhythmic bursting involving Na+ and Ca2+ in excitatory networks of brainstem and spinal cord: a modeling study

The rhythmic, synchronized bursting of neurons in a network is an important phenomenon that underlies many rhythmic behaviors such as breathing, locomotion, feeding, etc. The basic mechanisms of rhythmic bursting in excitatory networks are currently under debate in some areas of the brainstem and spinal cord, and controversies exist regarding the role of network interactions and cellular properties in their generation. We focus on a specific controversy concerning the role of the membrane currents persistent sodium (INaP) and the calcium-activated nonspecific cation current (ICAN) in network rhythms existing in brainstem slices containing the preBotzinger complex (preBotC), an important preparation relevant for understanding respiratory rhythm generation. We also address another type of rhythm existing in some of these preparations which has been proposed as fictive sighing. Using ideas suggested by and data gathered from experiments in this field, we constructed a mathematical, physiologically realistic model, which includes a description of cellular properties such as INaP, ICAN, Ca2+ current (ICa), the Na+/K+ pump current (IPump), IP3-mediated intracellular Ca2+ release, inactivation of INaP and intracellular Ca2+ release, and network properties such as synaptic coupling and excitatory drive to the network. Using this model, we investigated how the behavior of an isolated neuron depends on the relative expression of these properties, and how the behavior of a network of coupled neurons depends on the distribution of these properties across the network. We show that the role of a particular current such as INaP or ICAN in a network rhythm may depend on this distribution, and on the conditions of excitatory drive to and the overall strength of synaptic interactions in the network, offering a possible resolution of the controversy regarding the role of these currents in respiratory rhythm generation. We also propose a model of fictive sighing. Although our model was designed to address a specific controversy in a preparation of the brainstem concerned with repiratory rhythmogenesis, we expect that some of our results may be applicable to understanding the basic mechanisms of rhythmic bursting in excitatory networks in other areas of the brainstem and spinal cord.Ph.D., Biomedical Engineering -- Drexel University, 201

A TECNOLOGIA DAS CÉLULAS FOTOVOLTÁICAS

O desenvolvimento de células solares cristalinas teve início na década de 1950 e a partir da década de 60 já se fez o uso delas em programas espaciais. Desde então, estudos buscando o aumento da eficiência, redução dos custos na fabricação e uma maior confiabilidade dessas células são realizados. A indústria fotovoltáica cresce rapidamente, no entanto, o preço da energia solar ainda não é competitivo em relação ao preço da eletricidade gerada por outros meios, como por via hidrelétrica. Por esta razão, existe uma quantidade crescente de pesquisa dedicada à busca de custos menores de células solares, destacando-se estudos com polímeros e corantes orgânicos. Nesse trabalho iremos abordar células fotovoltaicas da primeira, segunda e, com maior ênfase, terceira geração. Dentro das células fotovoltaicas da terceira geração destacaremos as células fotovoltaicas orgânicas (SILVA. R.M.P, 2009).

Early and Late Endograft Limb Proximal Migration with Resulting Type 1b Endoleak following an EVAR for Ruptured AAA

Introduction. Seal zone failure after EVAR leads to type 1 endoleaks and increases the risk of delayed aortic rupture. Type 1b endoleaks, although rare, represent a true risk to the repair. Case Presentation. We report the case of a 65-year-old female who underwent emergent endovascular repair for a ruptured infrarenal abdominal aortic aneurysm and developed bilateral type 1b endoleaks following proximal migration of both endograft limbs. The right-side failure was diagnosed within 48 hours from the initial repair and the left side at the 1-year follow-up. Both sides were successfully treated with endovascular techniques. A review of the literature with an analysis of potential risk factors is also reported. Conclusion. For patients undergoing EVAR for ruptured AAA and with noncalcified iliac arteries, more aggressive oversizing of the iliac limbs is recommended to prevents distal seal zone failures

Preselection algorithm based on predictive control for direct matrix converter

This paper presents an enhanced predictive control strategy to reduce the calculation effort for direct matrix converters. The main idea is to preselect the switching states to decrease the calculation effort during each sample period. The proposed preselection algorithm enables a predefined cost function to consider only the preselected switching states to perform the expected control. On the basis of the preselection of switching states at each sample period, the proposed method can effectively reduce the calculation effort as well as show a good performance. The proposed predictive control scheme using only preselected switching states needed to generate the desired source/load current waveforms and control the input power factor. The feasibility of the proposed method is experimentally verified and results are presented in the paper

Crosstalks between Myo-Inositol Metabolism, Programmed Cell Death and Basal Immunity in Arabidopsis

BACKGROUND: Although it is a crucial cellular process required for both normal development and to face stress conditions, the control of programmed cell death in plants is not fully understood. We previously reported the isolation of ATXR5 and ATXR6, two PCNA-binding proteins that could be involved in the regulation of cell cycle or cell death. A yeast two-hybrid screen using ATXR5 as bait captured AtIPS1, an enzyme which catalyses the committed step of myo-inositol (MI) biosynthesis. atips1 mutants form spontaneous lesions on leaves, raising the possibility that MI metabolism may play a role in the control of PCD in plants. In this work, we have characterised atips1 mutants to gain insight regarding the role of MI in PCD regulation. METHODOLOGY/PRINCIPAL FINDINGS: - lesion formation in atips1 mutants depends of light intensity, is due to PCD as evidenced by TUNEL labelling of nuclei, and is regulated by phytohormones such as salicylic acid - MI and galactinol are the only metabolites whose accumulation is significantly reduced in the mutant, and supplementation of the mutant with these compounds is sufficient to prevent PCD - the transcriptome profile of the mutant is extremely similar to that of lesion mimic mutants such as cpr5, or wild-type plants infected with pathogens. CONCLUSION/SIGNIFICANCE: Taken together, our results provide strong evidence for the role of MI or MI derivatives in the regulation of PCD. Interestingly, there are three isoforms of IPS in Arabidopsis, but AtIPS1 is the only one harbouring a nuclear localisation sequence, suggesting that nuclear pools of MI may play a specific role in PCD regulation and opening new research prospects regarding the role of MI in the prevention of tumorigenesis. Nevertheless, the significance of the interaction between AtIPS1 and ATXR5 remains to be established

SUCESSÃO TESTAMENTÁRIA

O presente trabalho tratará sobre a sucessão testamentária, via sucessória conhecida como sucessão de acordo com a vontade do titular do patrimônio. Negócio jurídico personalíssimo que consiste na expressão de vontade de forma tácita - escrita - do testador em organizar seu patrimônio para depois da sua morte. Podem ser objetos de testamento não só bens de valor, mas outros, como por exemplo, o corpo da pessoa para fins de estudo, ou ainda o reconhecimento de um filho havido fora da relação conjugal. As formas de testamento são determinadas em lei, podendo ser de via ordinária, que são: público, cerrado, particular e os codicilos, e os especiais: marítimo, aeronáutico, militar e nuncupativo, este último excepcionalmente de forma oral. O testamento poderá ser revogado a qualquer tempo, antes da morte do testador. A revogação poderá ser total ou em parte, por outro testamento em qualquer uma das formas dispostas em lei, mas somente será revogado as disposições testamentárias que consistiram em patrimônio, outras disposições, como o reconhecimento de um filho, não podem ser revogadas. Lembrando que nesta modalidade deve ser observada a legítima dos herdeiros necessários quando houver estes, sua inobservância pode acarretar nulidade

Early and Late Endograft Limb Proximal Migration with Resulting Type 1b Endoleak following an EVAR for Ruptured AAA

Introduction. Seal zone failure after EVAR leads to type 1 endoleaks and increases the risk of delayed aortic rupture. Type 1b endoleaks, although rare, represent a true risk to the repair. Case Presentation. We report the case of a 65-year-old female who underwent emergent endovascular repair for a ruptured infrarenal abdominal aortic aneurysm and developed bilateral type 1b endoleaks following proximal migration of both endograft limbs. The right-side failure was diagnosed within 48 hours from the initial repair and the left side at the 1-year follow-up. Both sides were successfully treated with endovascular techniques. A review of the literature with an analysis of potential risk factors is also reported. Conclusion. For patients undergoing EVAR for ruptured AAA and with noncalcified iliac arteries, more aggressive oversizing of the iliac limbs is recommended to prevents distal seal zone failures

Arabidopsis seed content QTL mapping using high-throughput phenotyping: the assets of Near Infrared Spectroscopy

Seed storage compounds are of crucial importance for human diet, feed and industrial uses. In oleo-proteaginous species like rapeseed, seed oil and protein are the qualitative determinants that conferred economic value to the harvested seed. To date, although the biosynthesis pathways of oil and storage protein are rather well known, the factors that determine how these types of reserves are partitioned in seeds have to be identified. With the aim of implementing a quantitative genetics approach, requiring phenotyping of hundreds of plants, our first objective was to establish near-infrared reflectance spectroscopic (NIRS) predictive equations in order to estimate oil, protein, carbon and nitrogen content in Arabidopsis seed with high-throughput level. Our results demonstrated that NIRS is a powerful non-destructive, high-throughput method to assess the content of these four major components studied in Arabidopsis seed. With this tool in hand, we analysed Arabidopsis natural variation for these four components and illustrated that they all displayed a wide range of variation. Finally, NIRS was used in order to map QTL for these four traits using seeds from the Arabidopsis thaliana Ct-1 x Col-0 recombinant inbred line population. Some QTL co-localised with QTL previously identified, but others mapped to chromosomal regions never identified so far for such traits. This paper illustrates the usefulness of NIRS predictive equations to perform accurate high-throughput phenotyping of Arabidopsis seed content, opening new perspectives in gene identification following QTL mapping and Genome Wide Association Studies

High throughput analysis of Arabidopsis seed lipid, protein, carbon and nitrogen content by Near-Infrared Reflectance Spectroscopy in four recombinant inbred line populations

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