1,240 research outputs found

    Experimental Control and Characterization of Autophagy in Drosophila

    Get PDF
    Insects such as the fruit fly Drosophila melanogaster, which fundamentally reorganize their body plan during metamorphosis, make extensive use of autophagy for their normal development and physiology. In the fruit fly, the hepatic/adipose organ known as the fat body accumulates nutrient stores during the larval feeding stage. Upon entering metamorphosis, as well as in response to starvation, these nutrients are mobilized through a massive induction of autophagy, providing support to other tissues and organs during periods of nutrient deprivation. High levels of autophagy are also observed in larval tissues destined for elimination, such as the salivary glands and larval gut. Drosophila is emerging as an important system for studying the functions and regulation of autophagy in an in vivo setting. In this chapter we describe reagents and methods for monitoring autophagy in Drosophila, focusing on the larval fat body. We also describe methods for experimentally activating and inhibiting autophagy in this system and discuss the potential for genetic analysis in Drosophila to identify novel genes involved in autophagy

    Does Personality Play a Role in Computer Information Systems Performance?

    Get PDF
    This study represents an analysis of student performance in computer information systems (CIS) courses and the potential influence of Jungian personality traits on academic success in CIS courses. For this study, academic success is measured by grades achieved. The MBTI measurement scale was self-analyzed by students in CIS courses from fall 2008 through spring 2013. The data showed a statistically significant correlation between various personality dichotomies of the type (Extraversion-Introversion, Sensing-Intuition, Thinking-Feeling, and JudgingPerceiving) and higher grades scores. The results of this study indicate that course performance of groups of students are different relative to their personality type. In this study, Thinking type students performed better than Feeling types, and Judgers performed better than Perceivers

    Ethoarchaeology and Elementary Technology of Unhabituated Wild Chimpanzees at Assirik, Senegal, West Africa

    Get PDF
    Like other wild chimpanzees (Pan troglodytes), the savanna-dwelling apes of Assirik, Senegal, West Africa, make and use tools and so have an elementary technology. Unlike their more famous counterparts elsewhere in Africa, these apes are not observable at close range. Instead, they are amenable to etho-archaeological study, in which the indirect data of artifacts, remnants, and fecal contents add to the sparse behavioral data. These open-country hominoids show 15 behavioral patterns that appear to be material culture, in the minimal sense of socially learned behavioral diversity. These can be divided into subsistence (N = 7), social (5) and maintenance (3) activities shown at customary, habitual, or present levels of frequency. Some patterns, such as Termite Fish or Baobab Crack, leave behind assemblages of hundreds of artifacts or remnants in predictable contexts at enduring worksites. Other patterns are rare and ephemeral and are known only from anecdotal data. Almost all artifacts and remnants are non-lithic, and so their perishability limits their discovery and analysis. Maximally productive use of such data depends on close collaboration between archaeology and primatolog

    The ejection of runaway massive binaries

    Get PDF
    The runaway O-type stars HD 14633 and HD 15137 are both SB1 systems that were probably ejected from the open cluster NGC 654. Were these stars dynamically ejected by close gravitational encounters in the dense cluster, or did the binaries each receive a kick from a supernova in one member? We present new results from our investigation of the optical, X-ray, and radio properties of these binary systems to discuss the probable ejection scenarios. We argue that these binaries may have been ejected via dynamical interactions in the dense cluster environment. © 2007 International Astronomical Union

    The Role of Cognition and Social Functioning as Predictors in the Transition to Psychosis for Youth With Attenuated Psychotic Symptoms

    Get PDF
    In the literature, there have been several attempts to develop prediction models for youth who are at clinical high risk (CHR) of developing psychosis. Although there are no specific clinical or demographic variables that seem to consistently predict the later transition to psychosis in those CHR youth, in addition to attenuated psychotic symptoms, the most commonly occuring predictors tend to be poor social functioning and certain cognitive tasks. Unfortunately, there has been little attempt to replicate alogorithms. A recently published article by Cornblatt et al suggested that, for individuals with attentuated psychotic symptoms (APS), disorganized communication, suspiciousness, verbal memory, and a decline in social functioning were the best predictors of later transition to psychosis (the RAP model). The purpose of this article was to first test the prediction model of Cornblatt et al with a new sample of individuals with APS from the PREDICT study. The RAP model was not the best fit for the PREDICT data. However, using other variables from PREDICT, it was demonstrated that unusual thought content, disorganized communication, baseline social functioning, verbal fluency, and memory, processing speed and age were predictors of later transition to psychosis in the PREDICT sample. Although the predictors were different in these 2 models, both supported that disorganized communication, poor social functioning, and verbal memory, were good candidates as predictors for later conversion to psychosis

    A new deep SCUBA survey of gravitationally lensing clusters

    Full text link
    We have conducted a new deep SCUBA survey, which has targetted 12 lensing galaxy clusters and one blank field. In this survey we have detected several sub-mJy sources after correcting for the gravitational lensing by the intervening clusters. We here present the preliminary results and point out two highlights.Comment: 4 pages, 2 figures, "Multiwavelength Cosmology" Mykonos, June 2003, conference proceeding

    Stochastic volatility and leverage effect

    Get PDF
    We prove that a wide class of correlated stochastic volatility models exactly measure an empirical fact in which past returns are anticorrelated with future volatilities: the so-called ``leverage effect''. This quantitative measure allows us to fully estimate all parameters involved and it will entail a deeper study on correlated stochastic volatility models with practical applications on option pricing and risk management.Comment: 4 pages, 2 figure

    Statistical Models of Nuclear Fragmentation

    Full text link
    A method is presented that allows exact calculations of fragment multiplicity distributions for a canonical ensemble of non-interacting clusters. Fragmentation properties are shown to depend on only a few parameters. Fragments are shown to be copiously produced above the transition temperature. At this transition temperature, the calculated multiplicity distributions broaden and become strongly super-Poissonian. This behavior is compared to predictions from a percolation model. A corresponding microcanonical formalism is also presented.Comment: 12 pages, 5 figure

    Personal identity (de)formation among lifestyle travellers: A double-edged sword?

    Get PDF
    This article explores the personal identity work of lifestyle travellers – individuals for whom extended leisure travel is a preferred lifestyle that they return to repeatedly. Qualitative findings from in-depth semi-structured interviews with lifestyle travellers in northern India and southern Thailand are interpreted in light of theories on identity formation in late modernity that position identity as problematic. It is suggested that extended leisure travel can provide exposure to varied cultural praxes that may contribute to a sense of social saturation. Whilst a minority of the respondents embraced a saturation of personal identity in the subjective formation of a cosmopolitan cultural identity, several of the respondents were paradoxically left with more identity questions than answers as the result of their travels
    corecore