Radiocarbon, stable isotopic compositions and seawater chemical properties of Black Sea core-top sediments and CTD stations

Chloropigments and their derivative pheopigments preserved in sediments can directly be linked to photosynthesis. Their carbon and nitrogen stable isotopic compositions have been shown to be a good recorder of recent and past surface ocean environmental conditions tracing the carbon and nitrogen sources and dominant assimilation processes of the phytoplanktonic community. In this study we report results from combined compound-specific radiocarbon and stable carbon and nitrogen isotope analysis to examine the time-scales of synthesis and fate of chlorophyll-a and its degradation products pheophytin-a, pyropheophytin-a, and 132,173-cyclopheophorbide-a-enol until burial in Black Sea core-top sediments. The pigments are mainly of marine phytoplanktonic origin as implied by their stable isotopic compositions. Pigment ?15N values indicate nitrate as the major uptake substrate but 15N-depletion towards the open marine setting indicates either contribution from N2-fixation or direct uptake of ammonium from deeper waters. Radiocarbon concentrations translate into minimum and maximum pigment ages of approximately 40 to 1200 years. This implies that protective mechanisms against decomposition such as association with minerals, storage in deltaic anoxic environments, or eutrophication-induced hypoxia and light limitation are much more efficient than previously thought. Moreover, seasonal variations of nutrient source, growth period, and habitat and their associated isotopic variability are likely at least as strong as long-term trends. Combined triple isotope analysis of sedimentary chlorophyll and its primary derivatives is a powerful tool to delineate biogeochemical and diagenetic processes in the surface water and sediments, and to assess their precise time-scales.

A preference-based semantics for CTD reasoning

In [8] the authors developed a logical system based on the definition of a new non-classical connective ⊗ capturing the notion of reparative obligation. The system proved to be appropriate for handling well-known contrary-to-duty paradoxes but no model-theoretic semantics was presented. In this paper we fill the gap and define a suitable possible-world semantics for the system for which we can prove soundness and completeness. The semantics is a preference-based non-normal one extending and generalizing semantics for classical modal logics.

Diário da Constituinte [gravação de vídeo] : [programa n. 132]

Relatores Adjuntos da Comissão de Sistematização cumpriram o prazo e entregaram a revisão final das emendas ao anteprojeto de Constituição ao Presidente da Comissão Afonso Arinos (PFL-RJ). José Ignácio Ferreira (PMDB-ES) explica como foi minuciosa a análise das emendas. O PMDB, o PFL e o PDT fecharam acordo para aprovar o parecer sobre as emendas, sem admissão de destaques. Adolfo Oliveira (PL-RJ) diz que o anteprojeto receberá milhares de contribuições e vai merecer um estudo criterioso por parte do Relator Bernardo Cabral para o preparo de um projeto que some as propostas das comissões temáticas com as do Plenário. Vivaldo Barbosa (PDT-RJ) ressalta que, durante os próximos trinta dias, a sociedade como um todo e os constituintes poderão enviar suas emendas e espera que desse trabalho conjunto se possa produzir uma Constituição capaz de promover a democracia e a justiça social no país. Na sessão O Povo Pergunta, cidadão quer saber como os constituintes estão fazendo para a melhoria dos transportes públicos. Átila Lira (PFL-PI) responde que a Constituição tratará de princípios em relação ao sistema de transporte, como um serviço público de responsabilidade do Estado, podendo ser explorado diretamente ou por concessão à iniciativa privada. A Comissão de Sistematização da Assembleia Nacional Constituinte (ANC) reuniu-se extraordinariamente para votar dois projetos de decisão. O primeiro sobre a dívida externa e o outro sobre a transmissão obrigatória de todas as votações plenárias pelo rádio e televisão. Artur da Távola (PMDB-RJ) não considera que impor ao telespectador a transmissão obrigatória de todas as sessões seja a melhor solução, mas sugere que o tempo do programa Diário da Constituinte possa ser ampliado, de tal forma que seja transmitido o resumo dos trabalhos. Plínio de Arruda Sampaio (PT-SP) defende o projeto de decisão.

MicroRNA-132 is a physiological regulator of hematopoietic stem cell function and B-cell development

MicroRNAs are a class of small non-coding RNAs that negatively regulate gene expression. Several microRNAs have been implicated in altering hematopoietic cell fate decisions. Importantly, deregulation of many microRNAs can lead to deleterious consequences in the hematopoietic system, including the onset of cancer, autoimmunity, or a failure to respond effectively to infection. As such, microRNAs fine-tune the balance between normal hematopoietic output and pathologic consequences. In this work, we explore the role of two microRNAs, miR-132 and miR-125b, in regulating hematopoietic stem cell (HSC) function and B cell development. In particular, we uncover the role of miR-132 in maintaining the appropriate balance between self-renewal, differentiation, and survival in aging HSCs by buffering the expression of a critical transcription factor, FOXO3. By maintain this balance, miR-132 may play a critical role in preventing aging-associated hematopoietic conditions such as autoimmune disease and cancer. We also find that miR-132 plays a critical role in B cell development by targeting a key transcription factor, Sox4, that is responsible for the differentiation of pro-B cells into pre-B cells. We find that miR-132 regulates B cell apoptosis, and by delivering miR-132 to mice that are predisposed to developing B cell cancers, we can inhibit the formation of these cancers and improve the survival of these mice. In addition to miR-132, we uncovered the role of another critical microRNA, miR-125b, that potentiates hematopoietic stem cell function. We found that enforced expression of miR-125b causes an aggressive myeloid leukemia by downregulation of its target Lin28a. Importantly, miR-125b also plays a critical role in inhibiting the formation of pro-B cells. Thus, we have discovered two microRNAs with important roles in regulating normal hematopoiesis, and whose dregulation can lead to deleterious consequences such as cancer in the aging hematopoietic system. Both miR-132 and miR-125b may therefore be targeted for therapeutics to inhibit age-related immune diseases associated with the loss of HSC function and cancer progression.

Holopedium gibberum - an indicator of soft-water lakes? [Translation from: Fauna 21 130-132, 1968.]

In fresh waters the planktonic Crustacea are represented mainly by the two large groups, the Copepoda and the Cladocera. This study focuses on Holopedium gibberum and examines if the plankton is an indicator of soft-water lakes. H. gibberum is found throughout the northern half of the globe but its distribution is scattered and irregular. The study is based on a literature review and samples taken from water bodies in Norway.

Nutrient Enhanced Coastal Ocean Productivity (NECOP). Data report: CTD and hydrographic data, R/V Pelican cruise, April 3-11, 1993

The Nutrient Enhanced Coastal Ocean Productivity (NECOP) Program is a component of NOAA's Coastal Ocean Program. The central hypothesis of this research is: Anthropogenic nutrient inputs have enhanced coastal ocean productivity with subsequent impacts on coastal ocean water quality, living resource yields, and the global marine carbon cycle. The initial study area for this program is the Mississippi/Atchafalaya River Outflow and adjacent Louisiana shelf region.

Constraints on the symmetry energy and neutron skins from pygmy resonances in Ni-68 and Sn-132

Correlations between the behavior of the nuclear symmetry energy, the neutron skins, and the percentage of energy-weighted sum rule (EWSR) exhausted by the pygmy dipole resonance (PDR) in Ni-68 and Sn-132 are investigated by using different random phase approximation (RPA) models for the dipole response, based on a representative set of Skyrme effective forces plus meson-exchange effective Lagrangians. A comparison with the experimental data has allowed us to constrain the value of the derivative of the symmetry energy at saturation. The neutron skin radius is deduced under this constraint.

Rare earth complexes with Ge-132 and their catalytic hydrolysis to phosphatide bond of mononucleotide

The complexes of a series of rare earths with Ge-132 have been prepared. The carboxyl anions of Ge-132 molecule were coordinated to rare earth ion with chelate style. In the complexes molecule, the GeO3/2 group of Ge-132 were hydrolyzed to become -Ge(OH)(3) group, and later does:not coordinate with rare earth ions. All of the complexes possess similar properties. In aqueous solution of pH 6 and 50 degrees C, these complexes can obviously selectively catalytically hydrolize the phosphatide bond of 5'-AMP and 5'-dAMP into phosphatic acid and riboside.

The suppression of Ge-132 on the Maillard reaction of BSA by fluorescence spectrum

The fluorescences of BSA and glycosylated BSA were observed respectively. The lambda(cm) of BSA was 340 nm; while the lambda(cm) of glycosylated BSA was 436 nm. Because the fluorescence spectra of them were different greatly, we can observe the suppression of Ge-132 on the Maillard reaction of BSA without any interference of itself. It was showed that the fluorescence intensity of glycosylated BSA increased continuously with the cultured time, Ge-132 may suppress the Maillard reaction of BSA greatly, and the suppressing efficicency would be 32 %. The key site of the Maillard reaction of BSA is free amino groups of alanine residues on N-terminal amino group, besides the epsilon-amino groups of intrachain Lysine residues.

Ge-132稀土配合物及其对单核苷酸磷酯键的催化水解作用

Ｇｅ－１３２是具有广泛生物活性的一元羧酸有机锗倍半氧化物的低聚物，分子中存在类似冠醚的Ｇｅ－Ｏ－Ｇｅ大环结构．因此，有人认为Ｇｅ－１３２的生物活性可能与这种大环结构与体内金属离子形成配合物有关［１］，但尚无直接的实验证据．因此，合成Ｇｅ－１３２稀土配…

荧光法研究Ge-132对牛血清白蛋白Mailard反应的抑制作用

人体内氨基酸及蛋白质的非酶糖化反应（Ｍａｉｌａｒｄ反应）与糖尿病及其并发症的关系已经引起广泛注意［１］．有机锗化合物β－羧乙基锗倍半氧化物（Ｇｅ－１３２）具有预防糖尿病及调节糖代谢的作用［２］．研究Ｇｅ－１３２对Ｍａｉｌａｒｄ反应的抑制作用，对于开发…

荧光法研究 Ge-132 对苯丙氨酸 Maillard 反应的抑制作用

哺乳动物体内氨基酸及蛋白质的非酶糖化反应（Ｍａｉｌａｒｄ反应）与糖尿病及其并发症的关系已引起广泛关注［１］，β－羧乙基锗倍半氧化物（Ｇｅ－１３２）具有预防糖尿病和调节糖代谢的作用［２］，研究Ｇｅ－１３２对Ｍａｉｌａｒｄ反应的抑制作用对于开发防治糖尿病…

Ge-132与稀土离子的配合物及其对单核苷酸磷酯键的催化水解作用

Ge－132的羧酸阴离子与稀土离子螯合配位，生成3：1型配合物。在配合物中，Ge－132的GeO3/2基因水解为Ge（OH）3，并且不参与稀土配位，系列稀土离子配合物的结构性质基本相同，在50℃，pH值为6的水溶液中，该配合物选择性地催化5’－AMP或5’－dAMP的磷酯键水解断裂，生成相应的核苷和磷酸，而不影响碱基与戌糖之1间的苷键。