Constraints on the carbon cycle and climate during the early evolution of animals

One of the greatest challenges in science lies in disentangling causality in complex, coupled systems. This is illustrated no better than in the dynamic interplay between the Earth and life. The early evolution and diversification of animals occurred within a backdrop of global change, yet reconstructing the potential role of the environment in this evolutionary transition is challenging. In the 200 million years from the end-Cryogenian to the Ordovician, enigmatic Ediacaran fauna explored body plans, animals diversified and began to biomineralize, forever changing the ocean's chemical cycles, and the biological community in shallow marine ecosystems transitioned from a microbial one to an animal one.

In the following dissertation, a multi-faceted approach combining macro- and micro-scale analyses is presented that draws on the sedimentology, geochemistry and paleontology of the rocks that span this transition to better constrain the potential environmental changes during this interval.

In Chapter 1, the potential of clumped isotope thermometry in deep time is explored by assessing the importance of burial and diagenesis on the thermometer. Eocene- to Precambrian-aged carbonates from the Sultanate of Oman were analyzed from current burial depths of 350-5850 meters. Two end-member styles of diagenesis independent of burial depth were observed.

Chapters 2, 3 and 4 explore the fallibility of the Ediacaran carbon isotope record and aspects of the sedimentology and geochemistry of the rocks preserving the largest negative carbon isotope excursion on record---the Shuram Excursion. Chapter 2 documents the importance of temperature, fluid composition and mineralogy on the delta 18-O min record and interrogates the bulk trace metal signal. Chapter 3 explores the spatial variability in delta 13-C recorded in the transgressive Johnnie Oolite and finds a north-to-south trend recording the onset of the excursion. Chapter 4 investigates the nature of seafloor precipitation during this excursion and more broadly. We document the potential importance of microbial respiratory reactions on the carbonate chemistry of the sediment-water interface through time.

Chapter 5 investigates the latest Precambrian sedimentary record in carbonates from the Sultanate of Oman, including how delta 13-C and delta 34-S CAS vary across depositional and depth gradients. A new model for the correlation of the Buah and Ara formations across Oman is presented. Isotopic results indicate delta 13-C varies with relative eustatic change and delta 34-S CAS may vary in absolute magnitude across Oman.

Chapter 6 investigates the secular rise in delta 18-Omin in the early Paleozoic by using clumped isotope geochemistry on calcitic and phosphatic fossils from the Cambrian and Ordovician. Results do not indicate extreme delta 18-O seawater depletion and instead suggest warmer equatorial temperatures across the early Paleozoic.

Ictiólogos de la Argentina: Raúl Horacio Arámburu

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Analysing the contribution of ATM/ATR pathway activation in establishing the premature senescence of E2F1/E2F2-/- bone-marrow-derived macrophages

E2F1 and E2F2 transcription factors have an important role during the regulation of cell cycle. In experiments done with E2F1/E2F2 knockout mice, it has been described that bone-marrow-derived macrophages (BMDM) undergo an early rapid proliferation event related to DNA hyper-replication. As a consequence, DNA damage response (DDR) pathway is triggered and E2F1/E2F2 knockout macrophages enter premature senescence related to G2/M phase arrest. The exact mechanism trough which DNA hyper-replication leads to DDR in absence of E2F1 and E2F2 remains undiscovered. To determine whether the ATR/ATM pathway, the master regulator of G2/M checkpoint, might be the surveillance mechanism in order to regulate uncontrolled proliferation in the DKO model, we monitored and analysis biochemical properties of BMDM cultures in the presence of caffeine, a potent inhibitor of ATM/ATR activity. Our results show that the addition of caffeine abolishes premature senescence in DKO BMDM, stimulates γ-H2AX accumulation and decreases Mcm2 expression.

Mejora de la calidad del agua de consumo mediante el control y eliminación aniones tóxicos

El agua es un bien necesario para la vida . Por ello, la problemática del tratamient o de agua es un tema de gran interés a nivel mundial. Las desviaciones que se pueden producir en el sistema de potabilización actual hacen necesario encontrar nuevos métodos para la eliminación de las sustancias tóxicas que puedan estar presentes en el medio. De ntro de estas sustancia s tóxicas destacan los aniones inorgánicos debido, en gran medida , al impacto de la actividad hu mana sobre las reservas de agua, p ara su eliminación existen numerosas alternati vas. N o obstante, diversos estudios plantean el uso de los óxidos de hierro ya q ue han demostrado ser eficaces para la eliminación de un gran rango de sustancias , por este motivo , se decide trabajar con ellas. Para aumentar la eficacia de eliminación , los óxidos son soportados a un mineral de arcilla, la montmorillonita. El objetivo principal de este trabajo es el análisis de la eficacia de varios óxidos de hierro asociados a un mineral de arcilla para eliminar una batería de aniones tóxicos c ompuesta por cloruro, clorato, fluor uro, fosfato, nitrato y sulfato de una muestra de agua

The E2F2 Transcription Factor Sustains Hepatic Glycerophospholipid Homeostasis in Mice

Increasing evidence links metabolic signals to cell proliferation, but the molecular wiring that connects the two core machineries remains largely unknown. E2Fs are master regulators of cellular proliferation. We have recently shown that E2F2 activity facilitates the completion of liver regeneration after partial hepatectomy (PH) by regulating the expression of genes required for S-phase entry. Our study also revealed that E2F2 determines the duration of hepatectomy-induced hepatic steatosis. A transcriptomic analysis of normal adult liver identified "lipid metabolism regulation" as a major E2F2 functional target, suggesting that E2F2 has a role in lipid homeostasis. Here we use wild-type (E2F2(+/+)) and E2F2 deficient (E2F2(-/-)) mice to investigate the in vivo role of E2F2 in the composition of liver lipids and fatty acids in two metabolically different contexts: quiescence and 48-h post-PH, when cellular proliferation and anabolic demands are maximal. We show that liver regeneration is accompanied by large triglyceride and protein increases without changes in total phospholipids both in E2F2(+/+) and E2F2(-/-) mice. Remarkably, we found that the phenotype of quiescent liver tissue from E2F2(-/-) mice resembles the phenotype of proliferating E2F2(+/+) liver tissue, characterized by a decreased phosphatidylcholine to phosphatidylethanolamine ratio and a reprogramming of genes involved in generation of choline and ethanolamine derivatives. The diversity of fatty acids in total lipid, triglycerides and phospholipids was essentially preserved on E2F2 loss both in proliferating and non-proliferating liver tissue, although notable exceptions in inflammation-related fatty acids of defined phospholipid classes were detected. Overall, our results indicate that E2F2 activity sustains the hepatic homeostasis of major membrane glycerolipid components while it is dispensable for storage glycerolipid balance.

Statistiques des peche des sardiniers ivoiriens - annee 1981

This publication shows the statistics of the sardinella fleet in 1981. These statistics are the catches and the effort by sector every two weeks. These data come also by month. At the end, ara listed the prices of the fresh fish in boxes at the criee. 1981 has been better than 1980, mainly for Sardinella aurita.

As histórias de coletivos para uma psicologia brasileira contemporânea

Este trabalho pretende problematizar as concepções de coletivo que se apresentam nos discursos da psicologia brasileira contemporânea. Tomamos como campo os artigos da revista Psicologia e Sociedade e construímos duas imagens: a imagem do coletivo representação é acompanhada por concepções naturalizantes das categorias com as quais trabalha. Nesta imagem de coletivo a separação entre indivíduo e sociedade é bem marcada e acaba produzindo construções abstratas dos seus fenômenos. Ao percorrer uma breve história da psicologia vemos esta surgir como uma tecnologia voltada para a ?gestão? dos coletivos, construindo e reproduzindo conhecimentos acerca dos indivíduos e do social. A imagem dos coletivos clandestinos é pautada em referências que desestabilizam as fronteiras impostas das ciências modernas e concebem tanto o indivíduo quanto o social efeito de uma produção simultânea, problematizando as fprmas de cpnhecimento das ciências tradicionais. A metodologia conta com a perspectiva histórica de Michel Foucault que afirma a primazia das relações de poder, e com as contribuições de Bruno Latour e suas conexões criando hibridismos. A proposta metodológica foi um importante instrumento ara romper com as barreiras separatistas, acentuando a presença do pesquisadpr como participante igual aos outros elementos do campo de pesquisa, enfatizando que o modo de pesquisar é com o outro e não sobre o outro. Desta forma As histórias de coletivos para uma psicologia brasileira pretende desnaturalizar modos de produzir conhecimento e categorias de coletivos herméticas. Para finalizar entre formas de fazer e perceber o coletivo temos o trabalho de campo atravessado pordois sociólogos, Emile Durkheim e Gabriel Tarde, contribuindo com as problematizações dos coletivos representação e clandestinos. Gabriel Tarde contribui produzindo uma concepção de coletivo processual, onde a imitação e a invenção ressaltam o caráter relacional do indivíduo e do social e os coloca numa produção de dupla emergência.

HPV infection, a described cause for human cancer: HPV detection and molecular mechanisms of HPV carcinogenesis (Review).

[en]Human papillomavirus (HPV) belongs to the Papillomaviridae virus family and it is one of the most common sexual transmission infections. HPV genome is composed of eight genes, including two early genes and six late genes. Among these late genes, E6 and E7 code for proteins that trigger cell-cycle re-entry in infected cells, which can lead to cervical cancer development. The IARC (International Agency for Research Cancer) proposed a guideline based on Hill’s criteria to determine whether the relation between HPV infection and cervical cancer is causal or not. Epidemiological studies have demonstrated that HPV infection is a necessary but non-sufficient cause for cervical cancer. Furthermore, HPV infection is considered the first necessary cause described of a human cancer, being HPV16 and 18 carcinogenic to humans and the most studied types. Cervical cancer is the second leading cause of cancer death among women worldwide. Different screening programs are carried out with the aim of preventing cervical cancer; such as cytologies and HPV tests. There are two main methods which are equally usable to detect HPV: the real-time PCR assays and the array assays. Regarding the molecular mechanisms of HPV mediated malignancies, E2, E6 and E7 proteins of HPV16 lead to immune response evasion, inducing IL-10 and TGF-β1 gene expression. Besides, E6 and E7 proteins allow cell-cycle reentry, phosphorylating RB and ubiquitinating p53 respectively. HPV genome integration in host genome leads to the alteration of host and viral genes expression, including oncogenes and tumor suppressor genes. However, the differences of E6 and E7 oncoproteins in different HPV types is poorly known due to the fact that almost the most studied HPV type has been HPV16.

高山松的群体历史及其适应性进化研究

物种形成一直以来是进化生物学的一个中心议题。因为杂交能够快速创造出新的遗传变异和提高基因组重组率，加速物种形成和适应性进化，所以杂交物种形成是其重要的组成部分。但是直到最近几年，人们才逐渐意识到同倍体杂种形成的重要性和普遍性。此外，人工杂交种群结果证实了杂种的适应性起源于亲本基因的超亲分离现象，这些基因之间通过加和效应或上位效应相互连锁，并在杂种后代中逐渐固定，因此，探讨维持这种适应机制的杂种的连锁不平衡模式就显得尤为重要。到目前为止，关于自然杂种的核苷酸多态性和连锁不平衡结构的报道非常稀见，对杂种的进化历史知之更少。高山松能生长于亲本种不能正常繁殖生长的青藏高原上，这种极端环境为杂种的适应性进化和与亲本的生态隔离造就了绝佳的条件，其生态和生殖的稳定性极大地方便了我们研究植物物种形成和适应性进化的遗传机理，对高山松开展的生态学、遗传学的系列分析已使高山松成为同倍体杂种形成的经典范例。 该论文通过随机挑选7个核基因位点对5个高山松群体、3个油松群体和3个云南松群体的164个大配子体单倍体基因组进行了核苷酸多态性分析。研究发现：所有基因座位的单倍型组成和基因谱系的拓扑结构都支持高山松的多次杂交起源。高山松的平均核苷酸多态性与油松相当，θW达到0.0107;比云南松高出一倍;高于已报道的裸子植物类群遗传变异水平。高山松如此高的遗传多态性与其杂交特性和有效群体大有关。我们运用分子钟和共祖模拟分析，推测出高山松的有效群体为7.32 x 105。等位基因共祖时间模拟分析发现，杂交过程早于青藏高原的隆升，也即是说，在杂种稳定成种以前，两个亲本种之间存在广泛的渐渗杂交。此外，高山松杂种的群体间分化严重，并且在不同的群体中，我们找到了多个偏离中性的基因座位。由此说明，高山松复杂的进化历史和适应的策略区域化。 在显著偏离中性的基因座位上，选取群体历史清晰的高山松群体，对其全基因序列多态性和连锁不平衡结构进行了深入调查，以期找到选择作用位点或区域。Ara-like和Dhn1两个基因在高山松与亲本之间都没有发现固定变异。在高山松中，Ara-like基因和Dhn1基因核苷酸多态性式样和连锁不平衡结构存在明显差异，这说明在两个基因上选择作用的程度和方向不尽相同。 我们对Dhn1基因的多态性分布、LD结构和中性偏离水平进行了分析，结果表明，该基因可能在PdNX和PdLZ群体中受到平衡选择的作用。从Dhn1基因谱系结构可以看出有两种来源的等位基因造成这种平衡多态性，一种属于祖先类型，另一种是从云南松继承衍生而来。这两种等位基因之间的分化很大，极有可能造成编码蛋白的亚功能化。事实上，Dhn1编码的脱水蛋白在植物对环境的抗逆过程中发挥着重要作用。由此我们推测高山松在高海拔极端环境中的适应性进化与Dhn1基因的平衡作用有关。 对Ara-like和Dhn1基因进行HKA检测，结果表明，与Dhn1基因相比，在Ara-like基因上，双维管束亚属与单维管束亚属之间存在显著分化，沉默突变位点的分化Ksil达到了0.1392，远远高于平均水平0.0508;在双维管束亚属共发现了43个固定突变位点，其中有6个能导致氨基酸突变，它们有可能导致了Ara-like基因功能的分化。结合裸子植物近缘物种间共享多态性的普遍性，我们推测Ara-like基因可能在单维管束亚属中的进化速率加快，暗示其在单维管束亚属中的适应性进化。 最后，基因内连锁不平衡分析结果显示，随机筛选的基因座位之间不存在连锁不平衡。高山松平均的基因内LD程度非常低，仅有18%的信息位点之间显著连锁。平均基因内LD在油松和高山松中的衰减速率很快，尤其在杂种中下降最快，在不到200bp以内就降到0.1以下。 LD的结果印证了高山松的有效群体大和多次起源特性。另外，我们也怀疑杂交物种形成过程中染色体组的重组和重排频繁发生，也是造成自然杂种现有群体的LD水平低的一个主要原因。 通过LD衰减曲线估计高山松的平均单位重组率,比亲本油松高17倍，比云南松高45倍。这个结果表明，杂种共适应的基因间要维持超亲分离，需要强烈的自然选择压力，才能保持它们之间的连锁不平衡。

Using wildlife activity and antibiotic resistance analysis to model bacterial water quality in coastal ponds

Models that help predict fecal coliform bacteria (FCB) levels in environmental waters can be important tools for resource managers. In this study, we used animal activity along with antibiotic resistance analysis (ARA), land cover, and other variables to build models that predict bacteria levels in coastal ponds that discharge into an estuary. Photographic wildlife monitoring was used to estimate terrestrial and aquatic wildlife activity prior to sampling. Increased duck activity was an important predictor of increased FCB in coastal ponds. Terrestrial animals like deer and raccoon, although abundant, were not significant in our model. Various land cover types, rainfall, tide, solar irradiation, air temperature, and season parameters, in combination with duck activity, were significant predictors of increased FCB. It appears that tidal ponds allow for settling of bacteria under most conditions. We propose that these models can be used to test different development styles and wildlife management techniques to reduce bacterial loading into downstream shellfish harvesting and contact recreation areas.

Controlled adhesion and growth of long term glial and neuronal cultures on Parylene-c

This paper explores the long term development of networks of glia and neurons on patterns of Parylene-C on a SiO 2 substrate. We harvested glia and neurons from the Sprague-Dawley (P1-P7) rat hippocampus and utilized an established cell patterning technique in order to investigate cellular migration, over the course of 3 weeks. This work demonstrates that uncontrolled glial mitosis gradually disrupts cellular patterns that are established early during culture. This effect is not attributed to a loss of protein from the Parylene-C surface, as nitrogen levels on the substrate remain stable over 3 weeks. The inclusion of the anti-mitotic cytarabine (Ara-C) in the culture medium moderates glial division and thus, adequately preserves initial glial and neuronal conformity to underlying patterns. Neuronal apoptosis, often associated with the use of Ara-C, is mitigated by the addition of brain derived neurotrophic factor (BDNF). We believe that with the right combination of glial inhibitors and neuronal promoters, the Parylene-C based cell patterning method can generate structured, active neural networks that can be sustained and investigated over extended periods of time. To our knowledge this is the first report on the concurrent application of Ara-C and BDNF on patterned cell cultures. © 2011 Delivopoulos, Murray.

Culture practices of freshwater giant prawn in some selected areas of Mymensingh

A study was conducted to examine the culture practices of freshwater giant prawn, Macrobrachium rosenbergii in some selected areas of Mymensingh. Based on a sample of 100 farmers from three different upazila, namely Phulpur, Gouripur and Ishwargonj in Mymensingh district, 94% of farmers cultured prawn with fish in their pond. Only 6% of farmers cultured prawn, fish and dike crops for higher economic return. The culture period is typically nine months; hatchery produced post-larvae were stocked from May to June and harvested from November to January. Per hectare production of prawn, 375 kg/yr was very low because the farmers followed simple culture method. Most of the farmers made a profit of Tk. 68,403/ha/yr and the major costs incurred were for purchasing prawn seed and feed. The culture of prawn in pond system is technically possible under different conditions though expansion of small-scale prawn farming mainly depends on reduction of production costs. Future targets could be integration of pond prawn culture with other agricultural activities especially dike cropping and rice production in the monsoon.

Policy entrepreneurship in the development of public sector strategy: the case of London health reform

The development of health policy is recognized as complex; however, there has been little development of the role of agency in this process. Kingdon developed the concept of policy entrepreneur (PE) within his ‘windows’ model. He argued inter-related ‘policy streams' must coincide for important issues to become addressed. The conjoining of these streams may be aided by a policy entrepreneur. We contribute by clarifying the role of the policy entrepreneur and highlighting the translational processes of key actors in creating and aligning policy windows. We analyse the work in London of Professor Sir Ara Darzi as a policy entrepreneur. An important aspect of Darzi's approach was to align a number of important institutional networks to conjoin related problems. Our findings highlight how a policy entrepreneur not only opens policy windows but also yokes together a network to make policy agendas happen. Our contribution reveals the role of clinical leadership in health reform.

Aquaculture technologies in Bangladesh: an assessment of technical and economic performance and producer behavior

This study evaluates the performance of a wide range of aquaculture systems in Bangladesh. It is by far the largest of its kind attempted to date. The purpose of this study was to identify and analyze the most important production systems, rather than to provide a nationally representative overview of the entire aquaculture sector of Bangladesh. As such, the study yields a huge amount of new information on production technologies that have never been thoroughly researched before. The study reveals an extremely diverse array of specialized, dynamic and rapidly evolving production technologies, adapted to a variety of market niches and local environmental conditions. This is a testament to the innovativeness of farmers and other value chain actors who have been the principal drivers of this development in Bangladesh. Data was collected from six geographical hubs. This survey was conducted from November 2011 to June 2012. Technological performance in terms of detailed input and output information, fish management practices, credit and marketing, and social and environmental issues were captured by the survey questionnaire, which had both open and closed format questions. The study generated insights that enable better understanding of aquaculture development in Bangladesh.

长期施肥对土壤矿物粒级中碳水化合物分布特征的影响

土壤碳水化合物作为活性碳库的一部分，与土壤有机质转化所包含的复杂的微生物学、化学和物理学过程密切相关。本文采集公主岭市长期定位监测基地和沈阳农业大学田间试验地不同施肥处理的黑土和棕壤，通过超声分散方法得到细黏粒 (<0.2µm)，粗黏粒 (0.2-2µm)，粉粒 (2-50µm)，细砂粒 (50-250µm) 和粗砂粒 (250-2000µm)五个颗粒级别，研究化肥、有机肥的长期施用对两种土壤不同粒级中有机碳、氮和土壤碳水化合物 (中性糖和氨基糖) 的积累、分布特性的影响，并根据六碳糖与五碳糖的比值区分碳水化合物的植物或微生物的贡献，利用氨基葡萄糖/氨基半乳糖的比值进一步明确真菌和细菌对碳水化合物转化和富集的贡献。结果表明： 对于有机质水平较高的黑土来说，化肥和有机肥合理配施不仅显著增加了黑土有机碳、氮和碳水化合物含量，而且有利于它们在各粒级中的重新分布，如小粒级中土壤有机质明显损失，而大粒级中土壤有机质显著富集。在土壤原始有机质水平较低的土壤 (棕壤) 中，只有较高的有机肥用量才可以引起小粒级有机碳、氮向大粒级中的转移。暗示出长期施肥对土壤碳、氮以及碳水化合物的影响程度取决于土壤原有有机质水平，土壤有机碳在各粒级中的积累符合层级理论。粗砂粒级中土壤有机碳含量高和富集程度大是土壤质量较高的表征。 有机肥的施用引起了两种土壤各粒级，特别是大粒级中 (Gal+Man):(Ara+Xyl)比值的显著降低，表明植物源碳水化合物在有机质积累过程中的贡献要大于微生物源糖，说明有机肥中的植物源有机碳组分并不被土壤微生物全部矿化利用，而其中的一部分作为可利用的碳源或能源储藏在大粒级中，特别是粗砂粒级中。无论何种施肥处理，在有机质水平较高的黑土中，各粒级有机质中中性糖相对含量不变；但在有机质水平相对低的棕壤中，黏粒级有机质中中性糖相对含量都减小，粉粒和砂粒级有机质中中性糖相对含量增大。 在黑土处理中，施用有机肥有利于真菌源氨基糖相对积累，化肥则引起细菌源氨基糖所占比重的略微增加。有机肥和化肥配施在短期内会引起细菌活性的增强，可是从长期角度考虑，仍然是真菌源氨基糖的积累得到了加强。在有机质水平较低的棕壤中，几乎在所有的处理中，砂粒级均表现出细菌源氨基糖所占比重增加，而黏粒和粉粒级中真菌源氨基糖所占比重表现出一定程度的增加。