A minimal model of many body localization

We present a fully analytical description of a many body localization (MBL) transition in a microscopically defined model. Its Hamiltonian is the sum of one- and two-body operators, where both contributions obey a maximum-entropy principle and have no symmetries except hermiticity (not even particle number conservation). These two criteria paraphrase that our system is a variant of the Sachdev-Ye-Kitaev (SYK) model. We will demonstrate how this simple `zero-dimensional' system displays numerous features seen in more complex realizations of MBL. Specifically, it shows a transition between an ergodic and a localized phase, and non-trivial wave function statistics indicating the presence of `non-ergodic extended states'. We check our analytical description of these phenomena by parameter free comparison to high performance numerics for systems of up to $N=15$ fermions. In this way, our study becomes a testbed for concepts of high-dimensional quantum localization, previously applied to synthetic systems such as Cayley trees or random regular graphs. We believe that this is the first many body system for which an effective theory is derived and solved from first principles. The hope is that the novel analytical concepts developed in this study may become a stepping stone for the description of MBL in more complex systems.Comment: 21 pages, 8 figures, introduction rewritten, changed titl

Transgenic labeling of parvalbumin-expressing neurons with tdTomato

Parvalbumin (PVALB)-expressing fast-spiking interneurons subserve important roles in many brain regions by modulating circuit function and dysfunction of these neurons is strongly implicated in neuropsychiatric disorders including schizophrenia and autism. To facilitate the study of PVALB neuron function we need to be able to identify PVALB neurons in vivo. We have generated a bacterial artificial chromosome (BAC) transgenic mouse line expressing the red fluorophore tdTomato under the control of endogenous regulatory elements of the Pvalb gene locus (JAX # 027395). We show that the tdTomato transgene is faithfully expressed relative to endogenous PVALB expression throughout the brain. Furthermore, targeted patch clamp recordings confirm that the labeled populations in neocortex, striatum, and hippocampus are fast-spiking interneurons based on intrinsic properties. This new transgenic mouse line provides a useful tool to study PVALB neuron function in the normal brain as well as in mouse models of psychiatric disease.National Institute of Mental Health (U.S.) (Grant 5R01MH097104

Masstigio: o marketing no atual mercado de luxo

O mercado de luxo é o tema central desta monografia. O segmento cresceu consideravelmente nos últimos anos e a presente pesquisa tem o objetivo de investigar a transformação que vem ocorrendo nesse mercado aparentemente tão exclusivo. O foco do estudo recai principalmente sobre uma nova tendência de consumo que alguns especialistas de marketing batizaram de “Masstígio”. Esse fenômeno fez surgir uma série de novos aspectos no mercado de luxo, afetando diretamente o marketing das principais empresas. O Brasil desponta como um dos principais mercados do mundo. O crescente aumento de empresas estrangeiras em nosso país confirma o fascínio do consumidor brasileiro pelos produtos e serviços de luxo. O que o luxo representa hoje, entendê-lo como um segmento de negócio e analisar a gestão de marketing de algumas marcas tradicionais serão considerações abordadas no decorrer da pesquisa

Comparação da eficácia dos métodos químico-mecânico e mecânico de remoção de cárie na redução de streptococcus mutans e lactobacillus spp da dentina criada de dentes decíduos

The methods of caries removal have been the subject of many studies over the last years. At present, methods involving the least tissue invasion have been outstanding in the field of surgical-restorative treatment. In this context, the Carisolv™ system has appeared as a less traumatic and less invasive approach, particularly in pedodontics. Thus, the objective of the present study was to carry out a comparative analysis of the dentinal structure of primary molars before and after the removal of carious tissue by mechanical (low speed drills and conventional dentinal curettes) and chemomechanical (Carisolv™ kit) procedures based on quantitative culture for cariogenic bacteria to determine the number of bacteria present in the carious dentine after both treatments. Sixty primary molars from children ranging in age from 4 to 8 years, with active occlusal caries in dentine, were divided into two groups (A and B) of 30 teeth each, with group A having been treated by the chemomechanical technique and group B by the mechanical technique. Dentin samples were placed in glass vials containing 1 mL thioglycolate broth and submitted to culture to determine the number of S. mutans and Lactobacillus per mg of decayed dentine. The results did not reveal significant differences between the two methods of caries removal; however, the chemomechanical method was more efficient in completely eliminating S. mutans (p=0.02). In summary, the present results confirm previous studies showing that the two methods are comparable in reducing Lactobacillus, but Carisolv™ is more effective in the elimination of S. mutans.Os métodos de remoção de cárie têm sido objeto de muitos estudos nos últimos anos. Atualmente, aqueles que determinam mínima invasão tecidual têm se sobressaído no campo do tratamento cirúrgico-restaurador. Neste contexto, surgiu o sistema Carisolv™ como uma abordagem menos traumática, com destaque na odontopediatria e menos invasiva. Desta forma, este estudo teve como objetivo analisar comparativamente a estrutura dentinária de molares decíduos antes e após a remoção do tecido cariado pelos métodos mecânico (brocas de baixa rotação e curetas dentinárias convencionais) e químico-mecânico (Kit Carisolv™), através de exame microbiológico quantitativo, verificando-se o número de bactérias/mg presentes na dentina cariada após cada tratamento. Foram utilizados 60 molares decíduos de crianças na faixa etária de 4 a 8 anos de idade que apresentavam cárie oclusal ativa em dentina, os quais foram divididos em dois grupos (A e B) de 30 dentes cada, onde o grupo A foi tratado com a técnica químico-mecânica e o grupo B foi tratado com a técnica mecânica. As amostras de dentina foram coletadas e depositadas em frascos de vidro contendo 1mL de caldo Tioglicolato e pérolas de vidro. Em seguida, foram imediatamente encaminhadas para análise microbiológica para que fossem determinadas as concentrações de S. mutans e Lactobacillus por mg de dentina cariada. Os resultados não revelaram diferenças significantes na comparação dos dois métodos de remoção de cárie; contudo, foi verificado que o método químico-mecânico era mais eficiente na eliminação total de S. mutans (p=0,02). Em síntese, os nossos resultados confirmam alguns estudos prévios em que os métodos são comparáveis na redução de Lactobacillus, mas o Carisolv™ é mais eficaz na eliminação de S. mutans

Generation of ultrashort (~10ps) spontaneous emission pulses by quantum dots in a switched optical microcavity

We report on the generation of few-ps long spontaneous emission pulses by quantum dots (QDs) in a switched optical microcavity. We use a pulsed optical injection of free charge carriers to induce a large frequency shift of the fundamental mode of a GaAs/AlAs micropillar. We track in real time by time-resolved photoluminescence its fundamental mode during its relaxation, using the emission of the QD ensemble as a broadband internal light source. Sub-ensembles of QDs emitting at a given frequency, interact transiently with the mode and emit an ultrashort spontaneous emission pulse into it. By playing with switching parameters and with the emission frequency of the QDs, selected by spectral filtering, pulse durations ranging from 300 ps down to 6 ps have been obtained. These pulses display a very small coherence length, which opens potential applications in the field of ultrafast imaging. The control of QD-mode coupling on ps-time scales establishes also cavity switching as a key resource for quantum photonics.Comment: 11 pages, 8 figures; includes supplemental materia

Seismology of active stars

In this review we will discuss the current standing and open questions of seismology in active stars. With the longer photometric timeseries data that are --and will become-- available from space-missions such as Kepler we foresee significant progress in our understanding of stellar internal structures and processes --including interactions between them-- taking place in active stars in the next few years.Comment: 6 pages, 6 figures, accepted for publication in Astronomical Notes, proceedings of "The New Era of Helio- and Asteroseismology", 2012. 05. 20-25, Obergurgl (A

Tatu Magazine: os modos de ser e fazer do Repositório Digital Tatu

O trabalho desenvolvido pelo Repositório Digital Tatu se inscreve entre as iniciativas que visam colaborar para a preservação e divulgação de acervos relacionados à História da Educação, caracterizando-se como uma ferramenta de aproximação entre os documentos e historiadores interessados em pesquisar, produzir conhecimento e colaborar para o fortalecimento da educação, da cultura e da justiça social por meio da compreensão de fatos e acontecimentos do passado no tempo presente. Todo o trabalho desenvolvido possui um caráter inovador, pela proposta e pelas ferramentas que utiliza, e também interdisciplinar, pois necessita de conhecimentos de áreas distintas e específicas  para que possa se concretizar.Porém, mesmo que com objetivos e perspectivas de trabalho bastante definidas, o Repositório Digital Tatu é um projeto em construção e, neste sentido, muitos dos seus processos e organização estão sendo definidos na medida em que surgem novas demandas. Este foi o caso da Tatu Maganize, documento explorado nessa sessão e elaborado a partir da percepção pela necessidade de produzir um material que contivesse todo o procedimento de triagem, catalogação, limpeza, digitalização e publicação dos acervos que fazem parte do Repositório.Assim, buscou-se elaborar uma espécie de manual para consultas, com informações básicas e o histórico do site para que, tanto os bolsistas que integram o projeto, como outros pesquisadores interessados em entender a lógica do funcionamento do Repositório, pudessem consultar e ter acesso ao detalhamento sobre como o trabalho é desenvolvido. Na concepção do material, além do conteúdo, que considera pressupostos sobre o manuseio e problematização de fontes documentais relacionadas à história da educação, foram considerados aspectos relacionados com a concepção visual, uma vez que havia a intenção de produzir um material atrativo e de designer amigável, seguindo a lógica e proposta do Repositório Digital Tatu.Neste sentido, como bem diz o editorial da Tatu Magazine, a primeira edição da revista contém o modus operandi do Repositório Digital Tatu, aproximando-se de um manual de instruções sobre o trabalho que, a partir da Tatu Magazine, torna-se disponível de ser replicado por outros grupos interessados em juntar-se aos esforços pela preservação e divulgação de acervos por meio da internet.A expectativa é que novos números da Tatu Magazine possam ser publicados no decorrer do trabalho que vem sendo desenvolvido, com o objetivo, novamente, de normatizar os procedimentos e servir de subsídio de informações.A Tatu Magazine está disponível para acesso e donwload no site do Repositório Digital Tatu por meio do link http://sistemas.bage.unipampa.edu.br/tatu/index.php/2018/10/21/tatu-magazine

A poised fragment library enables rapid synthetic expansion yielding the first reported inhibitors of PHIP(2), an atypical bromodomain

Research into the chemical biology of bromodomains has been driven by the development of acetyl-lysine mimetics. The ligands are typically anchored by binding to a highly conserved asparagine residue. Atypical bromodomains, for which the asparagine is mutated, have thus far proven elusive targets, including PHIP(2) whose parent protein, PHIP, has been linked to disease progression in diabetes and cancers. The PHIP(2) binding site contains a threonine in place of asparagine, and solution screening have yielded no convincing hits. We have overcome this hurdle by combining the sensitivity of X-ray crystallography, used as the primary fragment screen, with a strategy for rapid follow-up synthesis using a chemically-poised fragment library, which allows hits to be readily modified by parallel chemistry both peripherally and in the core. Our approach yielded the first reported hit compounds of PHIP(2) with measurable IC50 values by an AlphaScreen competition assay. The follow-up libraries of four poised fragment hits improved potency into the sub-mM range while showing good ligand efficiency and detailed structural data

Improved X-ray detection and particle identification with avalanche photodiodes

Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2, and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g. to distinguish between x-rays and MeV electrons in our experiment.Comment: 6 pages, 6 figure

A multi-decade record of high quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) “living data” publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT_V3_GRID