983 resultados para Polyphosphate accumulating organism (pao)


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The sustainable control of animal parasitic nematodes requires the development of efficient functional genomics platforms to facilitate target validation and enhance anthelmintic discovery. Unfortunately, the utility of RNA interference (RNAi) for the validation of novel drug targets in nematode parasites remains problematic. Ascaris suum is an important veterinary parasite and a zoonotic pathogen. Here we show that adult A. suum is RNAi competent, and highlight the induction, spread and consistency of RNAi across multiple tissue types. This platform provides a new opportunity to undertake whole organism-, tissue- and cell-level gene function studies to enhance target validation processes for nematode parasites of veterinary/medical significance.

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BACKGROUND: "Cumulative meta-analysis" describes a statistical procedure to calculate, retrospectively, summary estimates from the results of similar trials every time the results of a further trial in the series had become available. In the early 1990 s, comparisons of cumulative meta-analyses of treatments for myocardial infarction with advice promulgated through medical textbooks showed that research had continued long after robust estimates of treatment effects had accumulated, and that medical textbooks had overlooked strong, existing evidence from trials. Cumulative meta-analyses have subsequently been used to assess what could have been known had new studies been informed by systematic reviews of relevant existing evidence and how waste might have been reduced.

METHODS AND FINDINGS: We used a systematic approach to identify and summarise the findings of cumulative meta-analyses of studies of the effects of clinical interventions, published from 1992 to 2012. Searches were done of PubMed, MEDLINE, EMBASE, the Cochrane Methodology Register and Science Citation Index. A total of 50 eligible reports were identified, including more than 1,500 cumulative meta-analyses. A variety of themes are illustrated with specific examples. The studies showed that initially positive results became null or negative in meta-analyses as more trials were done; that early null or negative results were over-turned; that stable results (beneficial, harmful and neutral) would have been seen had a meta-analysis been done before the new trial; and that additional trials had been much too small to resolve the remaining uncertainties.

CONCLUSIONS: This large, unique collection of cumulative meta-analyses highlights how a review of the existing evidence might have helped researchers, practitioners, patients and funders make more informed decisions and choices about new trials over decades of research. This would have led to earlier uptake of effective interventions in practice, less exposure of trial participants to less effective treatments, and reduced waste resulting from unjustified research.

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The primary enzyme involved in polyphosphate (polyP) synthesis, polyP kinase (ppk), has been deleted in Pseudomonas putida KT2440. This has resulted in a threefold to sixfold reduction in polyhydroxyalkanoate (PHA) accumulation compared with the wild type under conditions of nitrogen limitation, with either temperature or oxidative (H2O2) stress, when grown on glucose. The accumulation of PHA by Δppk mutant was the same as the wild type under nitrogen-limiting growth conditions. There was no difference in polyP levels between wild-type and Δppk strains under all growth conditions tested. In the Δppk mutant proteome, polyP kinase (PPK) was undetectable, but up-regulation of the polyp-associated proteins polyP adenosine triphosphate (ATP)/nicotinamide adenine dinucleotide (NAD) kinase (PpnK), a putative polyP adenosine monophosphate (AMP) phosphotransferase (PP_1752), and exopolyphosphatase was observed. Δppk strain exhibited significantly retarded growth with glycerol as carbon and energy source (42 h of lag period compared with 24 h in wild-type strain) but similar growth to the wild-type strain with glucose. Analysis of gene transcription revealed downregulation of glycerol kinase and the glycerol facilitator respectively. Glycerol kinase protein expression was also downregulated in the Δppk mutant. The deletion of ppk did not affect motility but reduced biofilm formation. Thus, the knockout of the ppk gene has resulted in a number of phenotypic changes to the mutant without affecting polyP accumulation.

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We report the exploration of some unique metabolic pathways in Perkinsus olseni a marine protist parasite, responsible to significant mortalities in mollusks, especially in bivalves all around the world. In Algarve, south of Portugal carpet shell clam Ruditapes decussatus mortalities can reach up to 70%, causing social and economic losses. The objective of studying those unique pathways, is finding new therapeutic strategies capable of controlling/eliminating P. olseni proliferation in clams. In that sense metabolic pathways, were explored, and drugs affecting these cycles were tested for activity. The first step involved the identification of the genes behind those pathways, the reconstitution of the main steps, and molecular characterization of those genes and later on, the identification of possible targets within the genes studied. Metabolic cycles were screened due to the fact of not being present in host or differ in a critical way, such as the following pathways: shikimate, MEP-­‐ isoprenoids, Leloir cycle for chitin production, purine biosynthesis (unique among protists), the de novo synthesis of folates (absent in metazoa) and some unique genes like, the alternative oxidase (a branch of respiratory chain) and the hypoxia sensor HPH. All those pathways were covered and possible chemical inhibition using therapeutic drugs was tested with positive results. The relation between the common host Ruditapes decussatus and P. olseni was also explored in a dimension not possible some years ago. With the accessibility to second generation sequencers and microarray analysis platforms, genes involved in host defense or parasite virulence and resistance to the host were deciphered, allowing aiming to new targets (mechanisms and pathways), offering new possibilities for the control of Perkinsus in close environments. The thousands of genes, generated by this work, sequenced and analyzed from this commercial valuable clam and for Perkinsus olseni will be an important and value tool for the scientific community, allowing a better understanding of host-­‐parasite interactions, promoting the usage of P. olseni as an emerging model for alveolata parasites.

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The vertebral column and its units, the vertebrae, are fundamental features, characteristic of all vertebrates. Developmental segregation of the vertebral bodies as articulated units is an intrinsic requirement to guarantee the proper function of the spine. Whenever these units become fused either during development or postsegmentation, movement is affected in a more or less severe manner, depending on the number of vertebrae affected. Nevertheless, fusion may occur as part of regular development and as a physiological requirement, like in the tetrapod sacrum or in fish posterior vertebrae forming the urostyle. In order to meet the main objective of this PhD project, which aimed to better understand the molecular and cellular events underlying vertebral fusion under physiological and pathological conditions, a detailed characterization of the vertebral fusion occurring in zebrafish caudal fin region was conducted. This showed that fusion in the caudal fin region comprised 5 vertebral bodies, from which, only fusion between [PU1++U1] and ural2 [U2+] was still traceable during development. This involved bone deposition around the notochord sheath while fusion within the remaining vertebral bodies occur at the level of the notochord sheath, as during the early establishment of the vertebral bodies. A comparison approach between the caudal fin vertebrae and the remaining vertebral column showed conserved features such as the presence of mineralization related proteins as Osteocalcin were identified throughout the vertebral column, independently on the mineralization patterns. This unexpected presence of Osteocalcin in notochord sheath, here identified as Oc1, suggested that this gene, opposing to Oc2, generally associated with bone formation and mature osteoblast activity, is potentially associated with early mineralization events including chordacentrum formation. Nevertheless, major differences between caudal fin region and anterior vertebral bodies considering arch histology and mineralization patterns, led us to use RA as an inductive factor for vertebral fusion, allowing a direct comparison of equivalent structures under normal and fusion events. This fusion phenotype was associated with notochord sheath ectopic mineralization instead of ectopic perichordal bone formation related with increased osteoblast activity, as suggested in previous reports. Additionally, alterations in ECM content, cell adhesion and blood coagulation were discussed as potentially related with the fusion phenotype. Finally, Matrix gla protein, upregulated upon RA treatment and shown to be associated with chordacentrum mineralization sites in regular development, was further described considering its potential function in vertebral formation and pathological fusion. Therefore with this work we propose zebrafish caudal fin vertebral fusion as a potential model to study both congenital and postsegmentation fusion and we present candidate factors and genes that may be further explored in order to clarify whether we can prevent vertebral fusion.

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This article offers a method of reading the courtroom which produces an alternative mapping of the space. My method combines a reading of Antonin Artaud’s Theatre of Cruelty with a Deleuzian theoretical analysis. I suggest that this is a useful method since it allows examination of the spatial praxes of the courtroom which pulsate with a power to organize, terrorize and to judge. This method is also able to conceptualize the presence of ‘‘screaming’’ bodies and living matter which are appropriated to build, as well as feed the presence and functioning of the courtroom space, or organism. By using a method that articulates the cry of these bodies in the shadow of the organism, it becomes clear that this cry is both unwelcome and suppressed by the courtroom. The howl of anxious bodies enduring the process and space of the law can be materialized through interruptions to the courtroom, such as when bodies stand when they should not and when they speak when they should be silent. These vociferous actualizations of the scream serve only to feed the organism they seek to disturb, yet if the scream is listened to before it disrupts, the interruption becomes-imperceptible to the courtroom. Through my Artaudian/Deleuzian reading, I give a voice to the corporeal gasp that lingers before the cry, which is embedded within the embodied multiplicity from which it is possible to draw a creative line of flight. The creative momentum of this line of flight produces a sustainable interruption to the courtroom process, which instead of being consumed by the system, has the potential to produce new courtroom alignments. My text therefore offers an alternative reading of the courtroom, and in doing so also offers a refined understanding of how to productively ‘‘interrupt’’ the courtroom process.

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Standarização de um posto de trabalho não é mais que definir o melhor método de trabalho que vai ser seguido por todos os operadores que trabalham no mesmo. Uma vez definido esse método, é importante para uma empresa ter noção da produtividade que podem alcançar, dado que pode ser retirado a partir deste método, e é no seguimento disto que surge o estudo dos métodos e tempos, mais concretamente o estudo dos tempos por cronometragem. A aplicação deste estudo foi despoletada pela necessidade do IKEA Industry de Paços de Ferreira, em dar o próximo passo na standarização dos seus postos de trabalho, área a área, e da necessidade de terem uma pessoa em cada área que analisa-se o trabalho que estava a ser feito e calcula-se o tempo de cada rotina. Neste documento, é realizada uma interligação entre os conceitos teóricos que o método exige, como todo o conjunto de fórmulas, restrições, análises e ponderações, com o contexto laboral onde o mesmo foi aplicado e a estratégia desenvolvida pelo IKEA na realização do estudo. O estudo dos métodos e tempos por cronometragem, de todos os métodos existentes, pode ser considerado o mais completo e complexo, uma vez que é mais que observar, registar e retirar uma média ponderada das observações. Este método baseia-se num modelo matemático, que interliga uma série de conceitos e que tem sempre o operador em consideração, seja na avaliação e análise das tarefas que requerem mais esforço dos mesmos, físico ou psicológico, seja em termos de tempos de pausas pessoais que a lei obriga a que as empresas deem. Este detalhe, neste método, é de grande importância, uma vez que a standarização é sempre vista pelos operadores como uma punição. As desvantagens deste método estão no grau de conhecimento e capacidade de observação exigidas ao analista para o executar. Melhor dizendo, um analista que vá executar este trabalho necessita observar muito bem a rotina de trabalho e conhecer onde começa, acaba e tudo o que a ela não pertence, antes de começar a registar seja que tempos forem. Para além disso, é exigido ao analista que perceba o ritmo de trabalho dos operadores através da observação dos mesmos, de modo a que ninguém seja prejudicado. E por fim, é necessária uma grande disponibilidade da parte do analista para retirar o máximo de observações possíveis. Com o intuito de facilitar esta análise, o IKEA Industry criou um ficheiro que compila toda a informação relacionada com o método, e uma explicação de todos os parâmetros que o analista necessita ter em atenção. Esta folha de trabalho foi validada à luz do método, como é possível verificar no decorrer do documento. Um detalhe importante a referir, é que por muito fidedigno que seja este método, tal como qualquer método de standarização, a mínima alteração da rotina de trabalho invalida de imediato o tempo total da rotina, tornando necessário realizar o estudo novamente. Uma vantagem do documento criado pelo IKEA, está na rápida adaptação a estas alterações, uma vez que, caso seja acrescentado ou removido um elemento à rotina, basta alterar o documento, observar e cronometrar os operadores a executar esse novo elemento, e quase automaticamente é definido um novo tempo total padronizado na rotina. Este documento foi criado para fins académicos e de conclusão de um grau académico, mas o estudo quando aplicado na empresa deu origem a contratações, o que só por si mostra as vantagens e impacto que o mesmo pode ter em contexto laboral. Em termos de produtividade, uma vez que a sua aplicação não foi executada a tempo de ser estudada neste documento, não foi possível avaliar a mesma.

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Do vasto rol de manifestações heráldicas da vila de Óbidos, destaca-se, pela sua monumentalidade e beleza, a pedra de armas do paço dos alcaides, tanto mais visível quanto se situa no histórico edifício que funcionou como precursor da ideia de recuperação e valorização do património histórico ao serviço de um aproveitamento turístico e comercial, uma vez que se trata da primeira pousada nacional inaugurada em Portugal. A análise de tão importante monumento heráldico dividir-se-á em duas partes: a primeira relativa à representação das armas reais; a segunda sobre as insígnias dos Noronhas. Além do estudo destas duas armas, procurar-se-á compreender o significado da sua representação conjunta, logrando destarte fornecer uma interpretação simbológica da manifestação em estudo.

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Chronic disorders, such as obesity, diabetes, inflammation, non-alcoholic fatty liver disease and atherosclerosis, are related to alterations in lipid and glucose metabolism, in which peroxisome proliferator-activated receptors (PPAR)α, PPARβ/δ and PPARγ are involved. These receptors form a subgroup of ligand-activated transcription factors that belong to the nuclear hormone receptor family. This review discusses a selection of novel PPAR functions identified during the last few years. The PPARs regulate processes that are essential for the maintenance of pregnancy and embryonic development. Newly found hepatic functions of PPARα are the mediation of female-specific gene repression and the protection of the liver from oestrogen induced toxicity. PPARα also controls lipid catabolism and is the target of hypolipidaemic drugs, whereas PPARγ controls adipocyte differentiation and regulates lipid storage; it is the target for the insulin sensitising thiazolidinediones used to treat type 2 diabetes. Activation of PPARβ/δ increases lipid catabolism in skeletal muscle, the heart and adipose tissue. In addition, PPARβ/δ ligands prevent weight gain and suppress macrophage derived inflammation. In fact, therapeutic benefits of PPAR ligands have been confirmed in inflammatory and autoimmune diseases, such as encephalomyelitis and inflammatory bowel disease. Furthermore, PPARs promote skin wound repair. PPARα favours skin healing during the inflammatory phase that follows injury, whilst PPARβ/δ enhances keratinocyte survival and migration. Due to their collective functions in skin, PPARs represent a major research target for our understanding of many skin diseases. Taken altogether, these functions suggest that PPARs serve as physiological sensors in different stress situations and remain valuable targets for innovative therapies.

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Eukaryotes contain inorganic polyphosphate (polyP) and acidocalcisomes, which sequester polyP and store amino acids and divalent cations. Why polyP is sequestered in dedicated organelles is not known. We show that polyP produced in the cytosol of yeast becomes toxic. Reconstitution of polyP translocation with purified vacuoles, the acidocalcisomes of yeast, shows that cytosolic polyP cannot be imported, whereas polyP produced by the vacuolar transporter chaperone (VTC) complex, an endogenous vacuolar polyP polymerase, is efficiently imported and does not interfere with growth. PolyP synthesis and import require an electrochemical gradient, probably as a driving force for polyP translocation. VTC exposes its catalytic domain to the cytosol and carries nine vacuolar transmembrane domains. Mutations in the VTC transmembrane regions, which are likely to constitute the translocation channel, block not only polyP translocation but also synthesis. Given that they are far from the cytosolic catalytic domain of VTC, this suggests that the VTC complex obligatorily couples synthesis of polyP to its import in order to avoid toxic intermediates in the cytosol. Sequestration of otherwise toxic polyP might be one reason for the existence of acidocalcisomes in eukaryotes.

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A l'époque Jia jing. Auteur : Sui yuan zhu ren (Chinois 3617-3642). Édition de la salle Fu wen.8 livres (42 hui).

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Les sites apuriniques/apyrimidinique (AP) représentent une forme de dommage à l’ADN hautement mutagène et ce type de dommage peut survenir spontanément ou être induit par une variété d’agents. Afin de préserver la stabilité génomique, deux familles d’endonucléases de type AP, endo-IV et exo-III, sont nécessaires pour contrecarrer les effets mutagènes des sites AP. Malgré l’identification de membres des deux familles dans plusieurs organismes unicellulaire tels que E.coli et S. cerevisiae, aucun membre de la famille endo-IV n’a été identifié chez les organismes multicellulaires à l’exception de C. elegans et de C. briggsae. Nous avons donc décidé d’investiguer l’importance biologique de APN-1 chez C. elegans par l’utilisation d’une approche de knockdown du gène. Dans notre étude, nous avons montré que le knockdown du gène apn-1 chez C. elegans, en utilisant des ARN d’interférence (ARNi), cause une accumulation de mutations spontanées et induites par des drogues résultant en un délai de l’éclosion des œufs ainsi que par une diminution de la survie et de la longévité des vers adultes. De plus, nous avons montré que cette accumulation de mutations mène à un délai dans la progression du cycle cellulaire durant l’embryogénèse, représentant possiblement une explication du délai dans l’éclosion des œufs. Nous avons montré qu’il y avait une augmentation du niveau de mutations dans la gorge des vers, sans toutefois pouvoir confirmer la distribution de APN-1 qui possède une étiquette GFP. Les animaux transgéniques APN-1-GFP n’exprimaient pas suffisamment de la protéine de fusion pour permettre une visualisation à l’aide d’un microscope à fluorescence, mais la protéine a été détectée par immunobuvardage de type western. Les animaux transgéniques APN-1-GFP étaient instables et avaient des phénotypes concordants avec les défauts génétiques. En conclusion, il semble que C. elegans aie évolué afin de retenir un niveau de base de APN-1 jouant ainsi un rôle versatile afin de maintenir l’intégrité génétique d’autant plus que cet organisme semble manquer plusieurs enzymes de la voie de réparation par excision de base.

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Phosphate (Pi) is one among the most important essential residues in maintenance and inheritance of life, with far diverse physiological role as structural, functional and energy transduction. Phosphate accumulation in wastewaters containing run off of fertilizers and industrial discharges is a global problem that results in algal blooms in bays, lakes and waterways. Currently available methods for removing phosphates from wastewater are based primarily on polyP accumulation by the activated sludge bacteria. PolyP plays a critical role in several environmental and biotechnological problems. Possible relation of interaction between polyP accumulation phenomenon, the low biomass, low Pi uptake, and varying results obtained in response to the impact of sodium chloride, pH, temperature, various inorganic salts and additional carbon sources studied, are all intriguing observations in the present investigation. The results of the present study have evidenced very clearly the scope for potential strains of bacteria from both sea water and marine sediments which could be exploited both for Pi removal in wastewater released by industries and intensive aquaculture practices in to the aquatic environment as well as to harness the potential strains for industrial production of polyP which was wide range of applications.

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The present work deals with the characterization of polyhydroxyalkanoates accumulating vibrios from marine benthic environments and production studies of polyhydroxyalkanoates by vibrio sp.BTKB33. Vibrios are a group of (iram negative, curved or straight motile rods that normally inhabit the aquatic environments.The present study therefore aimed at evaluating the occurrence of PHA accumulating vibrios inhabiting marine benthic environments; characterizing the potential PHA accumulators employing phenotypic and genotypic approaches and molecular characterization of the PHA synthase gene. The study also evaluated the PHA production in V:'hri0 sp. strain BTKB33, through submerged fennentation using statistical optimization and characterized the purified biopolymer. Screening for PHA producing vibrios from marine benthic environments. Characterization of PHA producers employing phenotypic and genotypic approaches.The incidence of PHA accumulation in Vibrio sp. isolated from marine sediments was observed to be high, indicating that the natural habitat of these bacteria are stressful. Considering their ubiquitous nature, the ecological role played by vibrios in maintaining the delicate balance of the benthic ecosystem besides returning potential strains, with the ability to elaborate a plethora of extracellular enzymes for industrial application, is significant. The elaboration of several hydrolytic enzymes by individuals also emphasize the crucial role of vibrios in the mineralization process in the marine environment. This study throws light on the extracellular hydrolytic enzyme profile exhibited by vibrios. It was concluded that apart from the PHA accumulation, presence of exoenzyme production and higher MAR index also aids in their survival in the highly challenging benthic enviromnents. The phylogenetic analysis of the strains and studies on intra species variation within PHA accumulating strains reveal their diversity. The isolate selected for production in this study was Vibrio sp. strain BTKB33, identified as V.azureus by 16S rDNA sequencing and phenotypic characterization. The bioprocess variables for PHA production utilising submerged fermentation was optimized employing one-factor-at-a-time-method, PB design and RSM studies. The statistical optimization of bioprocess variables revealed that NaCl concentration, temperature and incubation period are the major bioprocess variables influencing PHA production and PHA content. The presence of Class I PHA synthase genes in BTKB33 was also unveiled. The characterization of phaC genes by PCR and of the extracted polymer employing FTIR and NMR analysis revealed the presence of polyhydroxybutyrate, smallest known PI-IAs, having wider domestic, industrial and medical application. The strain BTKB33 bearing a significant exoenzyme profile, can thus be manipulatedin future for utilization of diverse substrates as C- source for PHA production. In addition to BTKB33, several fast growing Vibrio sp. having PHA accumulating ability were also isolated, revealing the prospects of this environment as a mine for novel PHA accumulating microbes. The findings of this study will provide a reference for further research in industrial production of PHAs from marine microorganisms .