211 research outputs found

    Diving behavior of the Emperor Penguin, Aptenodytes forsteri

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    Multi-layered control of Galectin-8 mediated autophagy during adenovirus cell entry through a conserved PPxY motif in the viral capsid.

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    Cells employ active measures to restrict infection by pathogens, even prior to responses from the innate and humoral immune defenses. In this context selective autophagy is activated upon pathogen induced membrane rupture to sequester and deliver membrane fragments and their pathogen contents for lysosomal degradation. Adenoviruses, which breach the endosome upon entry, escape this fate by penetrating into the cytosol prior to autophagosome sequestration of the ruptured endosome. We show that virus induced membrane damage is recognized through Galectin-8 and sequesters the autophagy receptors NDP52 and p62. We further show that a conserved PPxY motif in the viral membrane lytic protein VI is critical for efficient viral evasion of autophagic sequestration after endosomal lysis. Comparing the wildtype with a PPxY-mutant virus we show that depletion of Galectin-8 or suppression of autophagy in ATG5-/- MEFs rescues infectivity of the PPxY-mutant virus while depletion of the autophagy receptors NDP52, p62 has only minor effects. Furthermore we show that wildtype viruses exploit the autophagic machinery for efficient nuclear genome delivery and control autophagosome formation via the cellular ubiquitin ligase Nedd4.2 resulting in reduced antigenic presentation. Our data thus demonstrate that a short PPxY-peptide motif in the adenoviral capsid permits multi-layered viral control of autophagic processes during entry

    Gambling: Electronic friends or a threat to one's health and personal development?

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    Gambling has become quite common in Sweden. The Swedish National Institute of Public Health (2010) has reported that about 70% of the Swedish population has gambled at least once during the last 12 months. Half of the population had gambled with money by 18 years of age and about 11% had gambled for the first time when they were 12-years-old or younger. In the report from the Swedish National Institute of Public Health, gambling problems are related to health problems and risky alcohol consumption. The highest problem rate is found among men aged 18 to 24; almost 1 in 10 had some gambling problems. The share of problem gamblers is found to be twice as high among the under-age gamblers as it is among the population as a whole. Young people gamble less but develop gambling problems to a larger extent than adult gamblers. In this article young people's gambling and their gambling careers are analysed as a natural part of their internalisation of other adult habits

    Three SRA-Domain Methylcytosine-Binding Proteins Cooperate to Maintain Global CpG Methylation and Epigenetic Silencing in Arabidopsis

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    Methylcytosine-binding proteins decipher the epigenetic information encoded by DNA methylation and provide a link between DNA methylation, modification of chromatin structure, and gene silencing. VARIANT IN METHYLATION 1 (VIM1) encodes an SRA (SET- and RING-associated) domain methylcytosine-binding protein in Arabidopsis thaliana, and loss of VIM1 function causes centromere DNA hypomethylation and centromeric heterochromatin decondensation in interphase. In the Arabidopsis genome, there are five VIM genes that share very high sequence similarity and encode proteins containing a PHD domain, two RING domains, and an SRA domain. To gain further insight into the function and potential redundancy among the VIM proteins, we investigated strains combining different vim mutations and transgenic vim knock-down lines that down-regulate multiple VIM family genes. The vim1 vim3 double mutant and the transgenic vim knock-down lines showed decreased DNA methylation primarily at CpG sites in genic regions, as well as repeated sequences in heterochromatic regions. In addition, transcriptional silencing was released in these plants at most heterochromatin regions examined. Interestingly, the vim1 vim3 mutant and vim knock-down lines gained ectopic CpHpH methylation in the 5S rRNA genes against a background of CpG hypomethylation. The vim1 vim2 vim3 triple mutant displayed abnormal morphological phenotypes including late flowering, which is associated with DNA hypomethylation of the 5′ region of FWA and release of FWA gene silencing. Our findings demonstrate that VIM1, VIM2, and VIM3 have overlapping functions in maintenance of global CpG methylation and epigenetic transcriptional silencing

    Alternative methods of interpreting quality of life data in advanced gastrointestinal cancer patients

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    Understanding of how to analyse and interpret quality of life (QoL) data from clinical trials in patients with advanced cancer is limited. In order to increase the knowledge about the possibilities of drawing conclusions from QoL data of these patients, data from 2 trials were reanalysed. A total of 113 patients with pancreatic, biliary or gastric cancer were included in 2 randomised trials comparing chemotherapy and best supportive care (BSC) with BSC alone. Patient benefit was evaluated by the treating physician (subjective response) and by using selected scales and different summary measures of the EORTC QLQ-C30 questionnaire. An increasing number of drop-outs (mainly due to death) with time did not occur in a random fashion. Therefore, the mean scores in the different subscales of the QLQ-C30 obtained during the follow-up of interviewed patients did not reflect the outcome of the randomised population. The scores of the patient-provided summary measure, ‘Global health status/QoL’, were stable in a rather high proportion of the patients and could not discriminate between the 2 groups. 3 other summary measures revealed greater variability, and they all discriminated between the 2 groups. A high agreement was also seen between the changes in the summary measures and the subjective response. A categorisation of whether an individual patient had benefited or not from the intervention could overcome the problem with the selective attrition. © 2001 Cancer Research Campaig

    Evaluating the effectiveness of agricultural adaptation to climate change in preindustrial society

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    The effectiveness of agricultural adaptation determines the vulnerability of this sector to climate change, particularly during the preindustrial era. However, this effectiveness has rarely been quantitatively evaluated, specifically at a large spatial and long-term scale. The present study covers this case of preindustrial society in AD 1500–1800. Given the absence of technological innovations in this time frame, agricultural production was chiefly augmented by cultivating more land (land input) and increasing labor input per land unit (labor input). Accordingly, these two methods are quantitatively examined. Statistical results show that within the study scale, land input is a more effective approach of mitigating climatic impact than labor input. Nonetheless, these observations collectively improve Boserup's theory from the perspective of a large spatial and long-term scale.postprin

    Metal A and Metal B Sites of Nuclear RNA Polymerases Pol IV and Pol V Are Required for siRNA-Dependent DNA Methylation and Gene Silencing

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    Plants are unique among eukaryotes in having five multi-subunit nuclear RNA polymerases: the ubiquitous RNA polymerases I, II and III plus two plant-specific activities, nuclear RNA polymerases IV and V (previously known as Polymerases IVa and IVb). Pol IV and Pol V are not required for viability but play non-redundant roles in small interfering RNA (siRNA)-mediated pathways, including a pathway that silences retrotransposons and endogenous repeats via siRNA-directed DNA methylation. RNA polymerase activity has not been demonstrated for Polymerases IV or V in vitro, making it unclear whether they are catalytically active enzymes. Their largest and second-largest subunit sequences have diverged considerably from Pol I, II and III in the vicinity of the catalytic center, yet retain the invariant Metal A and Metal B amino acid motifs that bind magnesium ions essential for RNA polymerization. By using site-directed mutagenesis in conjunction with in vivo functional assays, we show that the Metal A and Metal B motifs of Polymerases IV and V are essential for siRNA production, siRNA-directed DNA methylation, retrotransposon silencing, and the punctate nuclear localization patterns typical of both polymerases. Collectively, these data show that the minimal core sequences of polymerase active sites, the Metal A and B sites, are essential for Pol IV and Pol V biological functions, implying that both are catalytically active

    Technology Adoption by Elderly People – An Empirical Analysis of Adopters and Non-Adopters of Social Networking Sites

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    This research paper analyzes the impact of attitudinal, control and normative beliefs on the intention to use social network sites (SNS) by people older than 50. Using the Model of Adoption of Technology in Households (MATH) and the data of 115 social network site adopters and 53 non-adopters it can be shown that the intention of adopters and non-adopters has been influenced by different reasons. Perceived Ease of Use and Normative Beliefs have only a significant impact for adopters. Moreover, this research paper unfolds Fear of Technology as a strong influence factor for non-adopters in regard not to use SNS in their daily routine. The paper concludes with a discussion of an age-sensitive design of SNS in order to address the digital divide
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