Zeta function method and repulsive Casimir forces for an unusual pair of plates at finite temperature

We apply the generalized zeta function method to compute the Casimir energy and pressure between an unusual pair of parallel plates at finite temperature, namely: a perfectly conducting plate and an infinitely permeable one. The high and low temperature limits of these quantities are discussed; relationships between high and low temperature limits are estabkished by means of a modified version of the temperature inversion symmetry.Comment: latex file 9 pages, 3 figure

O ciclo da vesícula sináptica, espinhos dendríticos e a transdução de sinal

In the nervous system, the synapse is the structure that allows a neuron pass an electrical or chemicalsignal to another neuron or another cell (muscle or glandular). The word synapse comes from "synaptein"that Sir Charles Scott Sherrington and his colleagues minted from the Greek "syn" (together) and "haptein"(buckling). Most part of the synaptic transmission is performed through chemical synapses. Chemicalsynapses have a slower response than the electric ones; they have the advantage of amplifying thesignal generated through a cascade of second messengers. Chemical synapses can be excitatory orinhibitory and are characterized by a presynaptic terminal (where there are vesicles that contain theneurotransmitters) in contact with a postsynaptic terminal (where there are the ionotropic and metabotropicreceptors) separated by the synaptic cleft. Synapses can occur on axons (axo-axonal), on dendrites (axodendritic), on soma (axo-somatic) and on dendritic spines. Dendritic spines are small profusions withthe function of synaptic compartmentalization. There is much information about classic neurotransmitters,such as acetylcholine, glutamate, GABA, glycine, dopamine, norepinephrine, and serotonin, but the studyof new neurotransmitter (i. e., ATP, nitric oxide, endocannabinoids, and neuropeptides) has advancedenormously. This review is a collection summary of key information from the recent literature describingthe molecular and functional aspects of the cycle of synaptic vesicle, the composition of postsynapticdensity, dendritic spines, and signal transduction.No sistema nervoso, a sinapse é a estrutura que permite a um neurônio passar um sinal elétrico ouquímico a outro neurônio ou outra célula (muscular ou glandular). A palavra sinapse vem de "synaptein",palavra que Sir Charles Scott Sherrington e seus colegas acunharam do grego "syn" (junto) e "haptein"(afivelar). As sinapses podem ser separadas entre elétricas e químicas, porém a maior parte da transmissão sináptica é realizada através das sinapses químicas. Apesar das sinapses químicas teremuma resposta mais lenta que as elétricas, elas possuem a vantagem da amplificação do sinal geradaatravés de uma cascata de segundos mensageiros. As sinapses químicas podem ser excitatórias ouinibitórias e são caracterizadas por um terminal pré-sináptico (onde estão presentes as vesículas quecontêm os neurotransmissores) em contato com um terminal pós-sináptico (onde estão presentes osreceptores ionotrópicos e metabotrópicos para esses neurotransmissores) separados pela fenda sináptica. As sinapses típicas acontecem sobre axônios (axo-axônicas), sobre dendritos (axo-dendríticas), sobre o soma de outro neurônio (axo-somáticas) e sobre os espinhos dendríticos. Os espinhosdendríticos são pequenas profusões da membrana celular especializadas na compartimentalizaçãosináptica. Atualmente há muita informação sobre a biossíntese dos neurotransmissores clássicoscomo acetilcolina, glutamato, GABA, glicina, dopamina, noradrenalina e serotonina e os seus receptores específicos para o funcionamento do sistema nervoso central (SNC). Ao mesmo tempo o estudo denovas substâncias neurotransmissoras (por exemplo ATP, óxido nítrico, endocanabinóides e neuropeptídeos) tem avançado enormemente. Esta revisão é uma seleção resumida de informações fundamentais a partir da literatura mais recente dos principais aspectos funcionais e moleculares do ciclo davesícula sináptica, da composição da densidade pós-sináptica, dos espinhos dendríticos e do mecanismo de transdução de sinal

Neurotransmissão glutamatérgica e plasticidade sináptica: aspectos moleculares, clínicos e filogenéticos

Communication between neurons is subject to constant changes, even in the adult brain. This ability ofneural circuits to strengthen or weaken their specific synaptic interactions (a phenomenon known assynaptic plasticity) may occur according to different environmental demands, which favors the idea thatdynamic changes in the communication between neurons underlie behavioral flexibility (i.e., learningand memory processes). In recent decades, advances in neuroscience has allowed a better understanding of synaptic plasticity, specially the plasticity of glutamatergic synapses, whose molecular processes of synaptic change appear to be among the most common throughout the central nervous system.Much of this progress in basic science has contributed to a better understanding of pathological processes involving the glutamatergic synapses, such as Alzheimer's disease. Furthermore, the growingunderstanding about the physiology of glutamatergic communication has helped explain how synapses,in general, would have originated and evolved in the phylogenetic scale of the Metazoa. This reviewattempts to address clinical aspects of glutamatergic neurotransmission, coA comunicação entre neurônios é passível de constantes modificações, até mesmo no encéfalo adulto.Esta capacidade de circuitos neuronais fortalecerem ou enfraquecerem suas interações sinápticasespecíficas (fenômeno conhecido como plasticidade sináptica) pode ocorrer de acordo com as diferentes demandas ambientais, o que favorece a noção de que alterações dinâmicas na comunicação entreneurônios estão na base da flexibilidade comportamental (i.e., processos de aprendizagem e memó-ria). Nas últimas décadas, o avanço das neurociências tem permitido uma melhor compreensão arespeito da plasticidade sináptica, especialmente a plasticidade de sinapses glutamatérgicas, cujosprocessos moleculares de modificação sináptica parecem estar entre os mais comuns de todo osistema nervoso central. Boa parte desse progresso na ciência básica tem contribuído para uma melhor compreensão acerca dos processos patológicos envolvendo as sinapses glutamatérgicas, comoa doença de Alzheimer. Além disso, a crescente compreensão sobre o funcionamento da comunicaçãoglutamatérgica tem ajudado a esclarecer como as sinapses, em geral, teriam se originado e evoluídona escala filogenética do reino animal (Metazoa). A presente revisão procura abordar aspectos clínicosda neurotransmissão glutamatérgica, porém propondo uma contextualização de tais aspectos clínicosem relação a conhecimentos básicos sobre plasticidade sináptica e evolução das sinapses

Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in the vertical direction is achieved. The ratio of positive to negative muons is studied between 20 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure

1000 Genomes-based meta-analysis identifies 10 novel loci for kidney function.

HapMap imputed genome-wide association studies (GWAS) have revealed >50 loci at which common variants with minor allele frequency >5% are associated with kidney function. GWAS using more complete reference sets for imputation, such as those from The 1000 Genomes project, promise to identify novel loci that have been missed by previous efforts. To investigate the value of such a more complete variant catalog, we conducted a GWAS meta-analysis of kidney function based on the estimated glomerular filtration rate (eGFR) in 110,517 European ancestry participants using 1000 Genomes imputed data. We identified 10 novel loci with p-value < 5 × 10(-8) previously missed by HapMap-based GWAS. Six of these loci (HOXD8, ARL15, PIK3R1, EYA4, ASTN2, and EPB41L3) are tagged by common SNPs unique to the 1000 Genomes reference panel. Using pathway analysis, we identified 39 significant (FDR < 0.05) genes and 127 significantly (FDR < 0.05) enriched gene sets, which were missed by our previous analyses. Among those, the 10 identified novel genes are part of pathways of kidney development, carbohydrate metabolism, cardiac septum development and glucose metabolism. These results highlight the utility of re-imputing from denser reference panels, until whole-genome sequencing becomes feasible in large samples

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10-11 to 5.0 × 10-21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10-6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation

Identification of inappropriate prescribing in a Brazilian nursing home using STOPP/START screening tools and the Beers' Criteria

The objective of this study was to determine the prevalence of Potentially Inappropriate Medication (PIM) use and associated factors, as well as the prevalence of Prescribing Omissions (PO). A cross-sectional study was conducted in a philanthropic Brazilian nursing home involving 46 individuals aged 60 years or older. The following information was collected from medical records and drug prescriptions: gender, age, health conditions and drugs used in the past thirty days. PIM and PO were identified according to the Beers' Criteria and the STOPP/START screening tools. Over one third (37%) of the population used at least one PIM according to the Beers' Criteria (n=17) and 60.9% according to the STOPP tool. A significant association was found between polypharmacy (use of five or more drugs) and use of PIM according to the Beers' Criteria, but not according to the STOPP. Eight residents (17.4%) were exposed to eight PO. This study allowed the diagnosis of a concerning drug utilization profile with use of a high number of PIMs. Thus, there is an evident need to implement strategies for improving geriatric prescription