350 research outputs found

    A Genomic-Based Approach Combining In Vivo Selection in Mice to Identify a Novel Virulence Gene in Leishmania

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    Parasites of the genus Leishmania cause a variety of human diseases that range from destructive skin lesions caused by L. major to visceral infections of the liver and spleen caused by L. donovani that result in death. The Leishmania genes responsible for these different pathologies are not known. In the present study, we used a comparative genome-based approach to introduce and over-express L. donovani genes in L. major to determine whether this results in increased virulence of L. major in visceral organs of infected mice. Through this approach, a novel gene termed Li1040 was identified that is potentially involved in protein transport and was shown to increase pathogenesis in the visceral organs in mice. The Li1040 gene may therefore represent a Leishmania virulence gene that has the potential to regulate the pathology of infection in the mammalian host. These observations help to define how Leishmania causes fatal infections in humans and therefore provide a parasite-specific target for therapy

    Efficiency in education

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    Education is important at national, local and individual levels. Its benefits accrue both to society and to individuals, and as such provision of education in many countries is paid for at least in part from the public purse. With competing demands for government funding, it is important for education to be provided as efficiently as possible. Efficiency occurs when outputs from education (such as test results or value added) are produced at the lowest level of resource (be that financial or, for example, the innate ability of students). This special issue is devoted to the topic of efficiency in education, and is well-timed given that governments around the world struggle with public finances in the wake of the global financial crisis of 2008. In this paper, we explore and provide an overview of the themes of the special issue and introduce the papers contained therein

    Is equal access to higher education in South Asia and sub-Saharan Africa achievable by 2030?

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    Higher education is back in the spotlight, with post-2015 sustainable development goals emphasising equality of access. In this paper, we highlight the long distance still to travel to achieve the goal of equal access to higher education for all, with a focus on poorer countries which tend to have lower levels of enrolment in higher education. Analysing Demographic and Health Survey data from 35 low- and middle-income countries in sub-Saharan Africa and South Asia, we show wide wealth inequalities in particular, with few if any of the poorest gaining access to higher education in some countries. We further identify that wealth and gender inequalities interact and tend to be wider in countries where levels of higher education are higher. This implies that expansion in access to higher education may predominantly benefit the rich, unless measures are taken to tackle inequalities. We find that that the rates of increase necessary for the attainment of the equal access goal by 2030 are particularly high. They pose a particularly difficult challenge given the access inequalities present from primary and secondary education in a wide majority of countries in our analysis. We therefore suggest that any measures aimed at attaining the goal need to tackle inequalities in access within a system-wide approach, focusing on the level of education at which inequalities initially manifest, alongside higher education.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10734-016-0039-

    Higher Education as modulator of gender inequalities: Evidence of the Spanish case

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    Raising educational levels may help to reduce inequalities between men and women in certain social and economic aspects. Using statistics for Spain, we analyse labour market behaviours such as the rates of activity and unemployment by sex according to the educational level. The results reveal that the differences between men and women decrease as the educational level increases. In particular, the modulator effect of education is very important at the higher level, where differences in labour market behaviour between men and women with an university education almost disappear, except in terms of salaries. Nevertheless, it can be seen that the current economic crisis has reduced the modulator role of education in gender differences in Spain

    Short-term acclimation in adults does not predict offspring acclimation potential to hypoxia

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    Abstract The prevalence of hypoxic areas in coastal waters is predicted to increase and lead to reduced biodiversity. While the adult stages of many estuarine invertebrates can cope with short periods of hypoxia, it remains unclear whether that ability is present if animals are bred and reared under chronic hypoxia. We firstly investigated the effect of moderate, short-term environmental hypoxia (40% air saturation for one week) on metabolic performance in adults of an estuarine amphipod, and the fitness consequences of prolonged exposure. We then reared the offspring of hypoxia-exposed parents under hypoxia, and assessed their oxyregulatory ability under declining oxygen tensions as juveniles and adults. Adults from the parental generation were able to acclimate their metabolism to hypoxia after one week, employing mechanisms typically associated with prolonged exposure. Their progeny, however, did not develop the adult pattern of respiratory regulation when reared under chronic hypoxia, but instead exhibited a poorer oxyregulatory ability than their parents. We conclude that species apparently hypoxia-tolerant when tested in short-term experiments, could be physiologically compromised as adults if they develop under hypoxia. Consequently, we propose that the increased prevalence of hypoxia in coastal regions will have marked effects in some species currently considered hypoxia tolerant

    General Education Learning Outcomes and Demographic Correlates in University Students in Hong Kong

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    Although there are studies showing that higher education would benefit university students, empirical research that comprehensively assesses student general education learning outcomes and related demographic correlates based on longitudinal data is minimal, especially in the Chinese context. To address the research gaps, the present study was conducted to investigate learning outcomes amongst university students in one university in Hong Kong based on a four-year longitudinal design (N = 460). Four dimensions of student general education learning outcomes were measured, including effective reasoning and problem solving, leadership, moral character, and integration of learning. Results suggested a U-shaped pattern of student learning outcomes for most dimensions, with no improvement or even a decrement in the second year and a steady growth thereafter. While family background did not affect student development, gender showed a significant moderating effect on students’ development in two dimensions (i.e., effective reasoning and problem solving, and integration of learning). These findings suggest that students benefit from general education-embedded university study in multiple dimensions, especially after the first year of transition period. Practical implications of the findings and future research directions were also discussed

    GTPase Activity and Neuronal Toxicity of Parkinson's Disease–Associated LRRK2 Is Regulated by ArfGAP1

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    Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of autosomal dominant familial Parkinson's disease (PD) and also contribute to idiopathic PD. LRRK2 encodes a large multi-domain protein with GTPase and kinase activity. Initial data indicates that an intact functional GTPase domain is critically required for LRRK2 kinase activity. PD–associated mutations in LRRK2, including the most common G2019S variant, have variable effects on enzymatic activity but commonly alter neuronal process morphology. The mechanisms underlying the intrinsic and extrinsic regulation of LRRK2 GTPase and kinase activity, and the pathogenic effects of familial mutations, are incompletely understood. Here, we identify a novel functional interaction between LRRK2 and ADP-ribosylation factor GTPase-activating protein 1 (ArfGAP1). LRRK2 and ArfGAP1 interact in vitro in mammalian cells and in vivo in brain, and co-localize in the cytoplasm and at Golgi membranes. PD–associated and functional mutations that alter the GTPase activity of LRRK2 modulate the interaction with ArfGAP1. The GTP hydrolysis activity of LRRK2 is markedly enhanced by ArfGAP1 supporting a role for ArfGAP1 as a GTPase-activating protein for LRRK2. Unexpectedly, ArfGAP1 promotes the kinase activity of LRRK2 suggesting a potential role for GTP hydrolysis in kinase activation. Furthermore, LRRK2 robustly and directly phosphorylates ArfGAP1 in vitro. Silencing of ArfGAP1 expression in primary cortical neurons rescues the neurite shortening phenotype induced by G2019S LRRK2 overexpression, whereas the co-expression of ArfGAP1 and LRRK2 synergistically promotes neurite shortening in a manner dependent upon LRRK2 GTPase activity. Neurite shortening induced by ArfGAP1 overexpression is also attenuated by silencing of LRRK2. Our data reveal a novel role for ArfGAP1 in regulating the GTPase activity and neuronal toxicity of LRRK2; reciprocally, LRRK2 phosphorylates ArfGAP1 and is required for ArfGAP1 neuronal toxicity. ArfGAP1 may represent a promising target for interfering with LRRK2-dependent neurodegeneration in familial and sporadic PD

    Understanding the programmatic and contextual forces that influence participation in a government-sponsored international student-mobility program

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    Although prior research establishes the forces that “push” and “pull” students to participate in foreign study, the transferability of findings from earlier studies is limited by the absence of theoretical grounding. In addition, relatively little is known about how a government-sponsored student mobility program promotes foreign study in a nation with a transitioning economy. Using case study methods, this study explores the characteristics of students who participate in such a program and identifies the programmatic characteristics and contextual forces that promote and limit participation. The findings shed light on the appropriate theoretical perspectives for understanding student participation in a government-sponsored mobility program and illustrate the need to consider how aspects of the national cultural, economic, and political context influence participation. The findings also raise several questions about how an international student mobility program should be structured to encourage participation and maximize benefits to individuals and society within a particular national context
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