Dynamical processes in the stratosphere and upper troposphere and their influence on the distribution of trace gases in the polar atmosphere

Transport plays an important role in the distribution of long-lived gases such as ozone and water vapour in the atmosphere. Understanding of observed variability in these gases as well as prediction of the future changes depends therefore on our knowledge of the relevant atmospheric dynamics. This dissertation studies certain dynamical processes in the stratosphere and upper troposphere which influence the distribution of ozone and water vapour in the atmosphere. The planetary waves that originate in the troposphere drive the stratospheric circulation. They influence both the meridional transport of substances as well as parameters of the polar vortices. In turn, temperatures inside the polar vortices influence abundance of the Polar Stratospheric Clouds (PSC) and therefore the chemical ozone destruction. Wave forcing of the stratospheric circulation is not uniform during winter. The November-December averaged stratospheric eddy heat flux shows a significant anticorrelation with the January-February averaged eddy heat flux in the midlatitude stratosphere and troposphere. These intraseasonal variations are attributable to the internal stratospheric vacillations. In the period 1979-2002, the wave forcing exhibited a negative trend which was confined to the second half of winter only. In the period 1958-2002, area, strength and longevity of the Arctic polar vortices do not exhibit significant long-term changes while the area with temperatures lower than the threshold temperature for PSC formation shows statistically significant increase. However, the Arctic vortex parameters show significant decadal changes which are mirrored in the ozone variability. Monthly ozone tendencies in the Northern Hemisphere show significant correlations (|r|=0.7) with proxies of the stratospheric circulation. In the Antarctic, the springtime vortex in the lower stratosphere shows statistically significant trends in temperature, longevity and strength (but not in area) in the period 1979-2001. Analysis of the ozone and water vapour vertical distributions in the Arctic UTLS shows that layering below and above the tropopause is often associated with poleward Rossby wave-breaking. These observations together with calculations of cross-tropopause fluxes emphasize the importance of poleward Rossby wave breaking for the stratosphere-troposphere exchange in the Arctic.

Solution conformation of a tetradecapeptide stabilized by two di-n-propyl glycine residues

The solution conformation of a designed tetradecapeptide Boc-Val-Ala-Leu-Dpg-Val-Ala-Leu-Val-Ala-Leu-Dpg-Val-Ala-Leu-OMe (Dpg-14) containing two di-n-propyl glycine (Dpg) residues has been investigated by H-1 NMR and circular dichroism in organic solvents. The peptide aggregates formed at a concentration of 3 mm in the apolar solvent CDCl3 were broken by the addition of 12% v/v of the more polar solvent DMSO-d(6). Successive NiH <-> Ni+1H NOEs observed over the entire length of the sequence in this solvent mixture together with the observation of several characteristic medium-range NOEs support a major population of continuous helical conformations for Dpg-14. Majority of the observed coupling constants ((3)(alpha)(JNHC)(H)) also support phi values in the helical conformation. Circular dichroism spectra recorded in methanol and propan-2-ol give further support in favor of helical conformation for Dpg-14 and the stability of the helix at higher temperature. Copyright (C) 2010 European Peptide Society and John Wiley & Sons, Ltd.

Softening and dynamic recrystallization in magnesium single crystals during c-axis compression

Commercial purity (99.8%) magnesium single crystals were subjected to plane strain compression (PSC) along the c-axis at 200 and 370 degrees C and a constant strain rate of 10(-3) s(-1). Extension was confined to the < 1 1 (2) over bar 0 > direction and the specimens were strained up to a logarithmic true strain of -1. The initial rapid increase in flow stress was followed by significant work softening at different stresses and comparable strains of about -0.05 related to macroscopic twinning events. The microstructure of the specimen after PSC at 200 degrees C was characterized by a high density of {1 0 (1) over bar 1} and {1 0 (1) over bar 3} compression twins, some of which were recrystallized. After PSC at 370 degrees C, completely recrystallized twin bands were the major feature of the observed microstructure. All new grains in these bands retained the same c-axis orientation of their compression twin hosts. The basal plane in these grains was randomly rotated around the c-axis, forming a fiber texture component. The obtained results are discussed with respect to the mechanism of recrystallization, the specific character of the boundaries between new grains and the initial matrix, and the importance of the dynamically recrystallized bands for strain accommodation in these deformed magnesium single crystals. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Novel M-Superfamily and T-Superfamily conotoxins and contryphans from the vermivorous snail Conus figulinus

The venom of Conus figulinus, a vermivorous cone snail, found in the south east coast of India, has been studied in an effort to identify novel peptide toxins. The amino acid sequences of seven peptides have been established using de novo mass spectrometric based sequencing methods. Among these, three peptides belong to the M-Superfamily conotoxins, namely, Fi3a, Fi3b, and Fi3c, and one that belongs to the T-Superfamily, namely, Fi5a. The other three peptides are contryphans, namely, contryphans fib, fic, and fid. Of these Fi3b, Fi3c, Fi5a, and contryphan fib are novel and are reported for the first time from venom of C.figulinus. The details of the sequencing methods and the relationship of these peptides with other M'-Superfamily conotoxins from the fish hunting and mollusk hunting clades are discussed. These novel peptides could serve as a lead compounds for the development of neuropharmacologically important drugs. Copyright (c) 2014 European Peptide Society and John Wiley & Sons, Ltd.

Crystal structure of a tripeptide containing aminocyclododecane carboxylic acid: a supramolecular twisted parallel -sheet in crystals

The crystal structure of a tripeptide Boc-Leu-Val-Ac(12)c-OMe (1) is determined, which incorporates a bulky 1-aminocyclododecane-1-carboxylic acid (Ac(12)c) side chain. The peptide adopts a semi-extended backbone conformation for Leu and Val residues, while the backbone torsion angles of the C-,C--dialkylated residue Ac(12)c are in the helical region of the Ramachandran map. The molecular packing of 1 revealed a unique supramolecular twisted parallel -sheet coiling into a helical architecture in crystals, with the bulky hydrophobic Ac(12)c side chains projecting outward the helical column. This arrangement resembles the packing of peptide helices in crystal structures. Although short oligopeptides often assemble as parallel or anti-parallel -sheet in crystals, twisted or helical -sheet formation has been observed in a few examples of dipeptide crystal structures. Peptide 1 presents the first example of a tripeptide showing twisted -sheet assembly in crystals. Copyright (c) 2016 European Peptide Society and John Wiley & Sons, Ltd.

Crystal structure of a tripeptide containing aminocyclododecane carboxylic acid: a supramolecular twisted parallel -sheet in crystals

The crystal structure of a tripeptide Boc-Leu-Val-Ac(12)c-OMe (1) is determined, which incorporates a bulky 1-aminocyclododecane-1-carboxylic acid (Ac(12)c) side chain. The peptide adopts a semi-extended backbone conformation for Leu and Val residues, while the backbone torsion angles of the C-,C--dialkylated residue Ac(12)c are in the helical region of the Ramachandran map. The molecular packing of 1 revealed a unique supramolecular twisted parallel -sheet coiling into a helical architecture in crystals, with the bulky hydrophobic Ac(12)c side chains projecting outward the helical column. This arrangement resembles the packing of peptide helices in crystal structures. Although short oligopeptides often assemble as parallel or anti-parallel -sheet in crystals, twisted or helical -sheet formation has been observed in a few examples of dipeptide crystal structures. Peptide 1 presents the first example of a tripeptide showing twisted -sheet assembly in crystals. Copyright (c) 2016 European Peptide Society and John Wiley & Sons, Ltd.

Separación de células cultivables y no cultivables mediante gradiente de densidad

Poster presentado al XX Congreso Nacional de Microbiología celebrado en Cáceres los días 19 -22 septiembre de 2005

Diário da Constituinte [gravação de vídeo] : [programa n. 595]

Realização de sessão solene em homenagem póstuma ao Senador Virgílio Távora. Postura do PMDB sobre a re-divisão do território nacional. Defesa, pelo Líder do PSC, Deputado Siqueira Campos, da criação do Estado de Tocantins. Proposta de desmembramento do Estado de Minas gerais para criação do Estado do Triângulo. Reassunção da Presidência da Assembleia Nacional Constituinte por Ulysses Guimarães. Defesa, pelo Presidente da ANC, da realização de eleições municipais em novembro de 1988.

A produção do conhecimento socialmente robusto no contexto da educação e do trabalho: inserção de moradores em comunidades do Rio de Janeiro no mercado de trabalho formal

O presente trabalho tem por objetivo analisar o processo de inserção de pessoas de baixa renda moradoras em comunidades do Rio de Janeiro no mercado de trabalho formal, alunos e egressos dos cursos da Educação Profissional oferecidos no âmbito do Programa SESI Cidadania (PSC), implantado pela Federação das Indústrias do Rio de Janeiro (FIRJAN), em 12 de agosto de 2010, por meio do acordo de cooperação com o Governo do Estado do Rio de Janeiro. O objetivo do programa é levar projetos sociais para as comunidades com Unidade de Polícia Pacificadora (UPP); dentre eles, projetos educacionais com oferta gratuita de cursos na modalidade Qualificação Profissional, respaldada no Decreto n 6.635, de 5 de novembro de 2008. Por conseguinte, este estudo visa a propor iniciativas no sentido de facilitar o ingresso e a permanência dessas pessoas no mercado de trabalho formal e a geração de trabalho e renda. A experiência da autora com processos de inserção de alunos e egressos de cursos da Educação Profissional oferecidos pelo Programa SESI Cidadania sinaliza que as dificuldades enfrentadas por moradores das comunidades do Rio de Janeiro estão relacionadas às condições históricas, sociais, econômicas e culturais. Diante dessa problemática, adotamos a seguinte hipótese: as competências comportamentais, dos moradores das comunidades do Rio de Janeiro interferem na sua inserção no mercado de trabalho formal. Nesse aspecto, o foco de investigação foi verificar as competências observadas pelos profissionais de recursos humanos que interferem na inserção e permanência desses egressos nas empresas. Adotamos o conceito de competências entendido por Joel Souza Dutra (2001) bem como por alguns teóricos da Administração, que o definem como um conjunto de conhecimentos, habilidades e atitudes necessárias para que a pessoa desenvolva suas atribuições e responsabilidades. O recorte empírico se constituiu de dez empresas de pequeno, médio e grande porte sediadas na Região Metropolitana do Rio de Janeiro. A abordagem metodológica incluiu pesquisa de campo com base em dados de entrevistas semiestruturadas, sendo incorporada a técnica de análise de relato verbal. Formulamos um questionário para realização de entrevistas semidirigidas com profissionais de Recursos Humanos e dirigentes de empresas as quais nos permitiram identificar os fatores que interferem na inserção dessas pessoas no mercado de trabalho formal. As conclusões apontam dificuldades de inserção e permanência de moradores das comunidades do Rio de Janeiro no mercado de trabalho formal por aspectos relacionados à formação educacional básica, e sobretudo a competências comportamentais desenvolvidas no contexto sociocultural no qual estão inseridos, as quais se encontram desassociadas das competências comportamentais demandadas pelo mercado de trabalho formal. A relevância da pesquisa consiste na possibilidade de subsidiar a formulação de políticas públicas da Educação e do trabalho destinadas à formação profissional de pessoas de baixa renda moradoras das comunidades do Rio de Janeiro para geração de trabalho e renda.

Effect of paradoxical sleep deprivation and stress on passive avoidance behavior

Previous studies have shown that several types of stress can induce memory impairment. However, the memory effects of paradoxical sleep deprivation (PSD), a stressor in itself, are unclear. We therefore compared passive avoidance behavior of rats undergoing PSD and PSD stress yoked-control (PSC) using the "reversed flowerpot method." When rats were kept isolated on a PSC platform for 24 It immediately after criterion training, retention trials showed impaired aversive memory storage. When delayed for 24 h after criterion training, PSC stress did not disrupt retention performance. In rats subjected to PSD, either immediately or 24 It after criterion training, there was no disruption of aversive memory consolidation. These results suggest that, during stress, paradoxical sleep plays a role in erasing aversive memory traces, in line with the theory that we "dream in order to forget." (C) 2003 Elsevier Inc. All rights reserved.

Photoexcited charge current for the presence of pure spin current

The asymmetric spin distribution in k space caused by the pure spin current (PSC) can introduce a photoexcited charge current (PECC). This provides us a practical scheme for direct detection of PSC. We demonstrate theoretically that the PECC related to the PSC depends sensitively on the wave vector and spin orientation of the carriers, more important, the helicity dependence of this PECC provides us a way to refine it from the helicity independent background current by tuning the polarized laser beams from left to right circular polarization.

大鼠海马CA1区神经元高级可塑性（Metaplasticity）的研究

经验（experience）或突触活动依赖的突触信息传递效能的增强（LTP）或抑制（LTD）被称为突触可塑性（synaPticplasticity），是公认的学习和记忆的细胞分子学基础。突触可塑性的方向是突触信息传递效能的增强或降低；突触可塑性的程度是突触信息传递的效能增加量或降低量。突触活动历史可影响随后突触可塑性的方向或程度。这种突触可塑性的可塑性被称为高级可塑性（MetaP1asticity）。最明显的高级可塑性现象是发生在突触效能没有改变的情况下。经验或者突触活动可以同时诱导出突触可塑性和高级可塑性。除非知道突触活动的历史，否则很难预测突触可塑性的大小和方向。高级可塑性简单地讲就是过去的神经信息留下痕迹会对神经信息的加工处理产生持续性影响。目前高级可塑性的机理并不完全清楚。采用全细胞电压钳记录方法，在3周龄wistar大鼠海马脑片中，同时记录schaffer侧枝纤维一以1处兴奋性突触后膜电流（evokedEPsC）和自发性微小兴奋性突触后膜"电流（mEPSC）。结果显示，mEPSC和低频刺激诱导的长时程抑制（Long一TermDePre55ion，LTD）之间呈负相关，mEPsc的频率或幅值越小，诱导出的LTD幅度越大；应激和低钙溶液处理在降低记PsC的频率和幅值的同时并没有明显改变随后LTD的诱导幅，但是这两者负相关性依然存。相关系数在应激条件下有增加，在低钙溶液中有降低。以上结果提示，mPEsc的频率或幅值可能指示了过去的突触活动或经验产牛的高幼可朔件＿田、冲稀恻了喃层的，：。、云导的幅度。C鹉子妙触可黔和高级可黔中起着关键作。作为一种非选择性阳离子通道，van11101drec即tortyPel（VR1或TRPVI）在脑区中广泛表达，尤其在海马高表达。内源性配体可以激活该受体通道。但目前并不清楚vRI在海马突触可塑性当中的作用。我们发现VRI激动剂辣椒素不影响脑片中海马以1区基础突触传递，但是它阻断低频诱导（LFS，3Hz）的LTD，增强高频诱导（HFs，20OHz）的长时程增强（Long一TerlnPotetiantion，LTP）。也就是vRI激活改变了突触可塑性的方向，是一种经典的高级可塑性现象。正常情况下50Hz不能诱导出LTP，而加入辣椒素后易化了LTP的诱导。因此LTP诱导的闽值降低。辣椒素激动剂对突触可塑性或高级可塑性的效应不依赖协。A受体而依赖于H型钙调蛋白激酶（CaMKII）的调控。因为场。A受体电流和它的电流一电压曲线不受此激动剂影响，但CaMKII抑制剂KN-93或者VRI拮抗剂capsazepine却阻断了辣椒素的这种效应。这些发现，显示VRI可以调控海马以1区的高级突触可塑性，可能参与某些类型的学习和记忆。

华北平原冬小麦冠层导度的环境响应及模拟

通过引入叶面积指数,将叶片水平的气孔导度组合模型扩展到冠层水平,建立了冠层导度环境响应组合模型,组合模型所需参数较少,且均可在冠层水平直接测量,便于应用;模型由潜在气孔导度(PSC)和相对气孔开度(RDO)组成,二者分别由环境变量的日际(inter-day)和日间(intra-day)的值决定。分析表明,冠层导度在日际尺度和日间尺度上对环境变量具有多尺度响应特性,在日际尺度上,温度是影响冠层导度的主要因子,在日间尺度,光是影响气孔开闭的主要因素。利用以温度和光合有效辐射为输入变量构建的组合模型,模拟了华北

Aminic nitrogen-bearing polydentate Schiff base compounds as corrosion inhibitors for iron in acidic media: A quantum chemical calculation

Quantum chemical calculations based on DFT method were performed on three polydentate Schiff base compounds (PSCs) used as corrosion inhibitors for iron in acid media to determine the relationship between the molecular structure of PSC and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energy HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), the charge distribution of the studied inhibitors, the absolute electronegativity (chi) values, and the fraction of electrons (Delta N) transfer from inhibitors to iron, were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of PSCs increased with the increase in E-HOMO and decrease in E-LUMO-E-HOMO; and the areas containing N atoms are most possible sites for bonding the metal iron surface by donating electrons to the metal. (C) 2007 Elsevier Ltd. All rights reserved.

WNT3 is a biomarker capable of predicting the definitive endoderm differentiation potential of hESCs.

Generation of functional cells from human pluripotent stem cells (PSCs) through in vitro differentiation is a promising approach for drug screening and cell therapy. However, the observed large and unavoidable variation in the differentiation potential of different human embryonic stem cell (hESC)/induced PSC (iPSC) lines makes the selection of an appropriate cell line for the differentiation of a particular cell lineage difficult. Here, we report identification of WNT3 as a biomarker capable of predicting definitive endoderm (DE) differentiation potential of hESCs. We show that the mRNA level of WNT3 in hESCs correlates with their DE differentiation efficiency. In addition, manipulations of hESCs through WNT3 knockdown or overexpression can respectively inhibit or promote DE differentiation in a WNT3 level-dependent manner. Finally, analysis of several hESC lines based on their WNT3 expression levels allowed accurate prediction of their DE differentiation potential. Collectively, our study supports the notion that WNT3 can serve as a biomarker for predicting DE differentiation potential of hESCs.