10,649 research outputs found

    Is Africa’s Skepticism of Foreign Capital Justified? Evidence from East African Firm Survey Data

    Get PDF
    The world has increasingly recognized that private capital has a vital role to play in economic development. African countries have moved to liberalize the investment environment, yet have not received much FDI. At least part of this poor performance is because of lingering skepticism toward foreign investment, owing to historical, ideological, and political reasons. This wariness has manifested in many ways, including a range of business environment factors that impede greater foreign flows. Although much of the ideological resistance has faded, a number of specific challenges to the purported benefits of FDI have been successful in preventing more active liberalization and in moving to deal with indirect barriers. New data from firm surveys in Kenya, Tanzania, and Uganda suggest that there are important positive effects from FDI for both the host economies and the workers in foreign-owned firms. Based on our three-country sample, foreign firms are more productive, bring management skills, invest more heavily in infrastructure and in the training and health of their workers, and are more connected to global markets. At the same time, foreign firms do not appear to succeed by grabbing market share and crowding out local industry. These results suggest that many of the common objections to foreign investment are exaggerated or false. Africa, by not attracting more FDI, is therefore failing to fully benefit from the potential of foreign capital to contribute to economic development and integration with the global economy. Length: 30 pagesAfrica, foreign capital, Kenya, Tanzania, Uganda, foreign direct investment,

    Compressive force generation by a bundle of living biofilaments

    Full text link
    To study the compressional forces exerted by a bundle of living stiff filaments pressing on a surface, akin to the case of an actin bundle in filopodia structures, we have performed particulate Molecular Dynamics simulations of a grafted bundle of parallel living (self-assembling) filaments, in chemical equilibrium with a solution of their constitutive monomers. Equilibrium is established as these filaments, grafted at one end to a wall of the simulation box, grow at their chemically active free end and encounter the opposite confining wall of the simulation box. Further growth of filaments requires bending and thus energy, which automatically limit the populations of longer filaments. The resulting filament sizes distribution and the force exerted by the bundle on the obstacle are analyzed for different grafting densities and different sub- or supercritical conditions, these properties being compared with the predictions of the corresponding ideal confined bundle model. In this analysis, non-ideal effects due to interactions between filaments and confinement effects are singled out. For all state points considered at the same temperature and at the same gap width between the two surfaces, the force per filament exerted on the opposite wall appears to be a function of a rescaled free monomer density ρ^1eff\hat{\rho}_1^{\rm eff}. This quantity can be estimated directly from the characteristic length of the exponential filament size distribution PP observed in the size domain where these grafted filaments are not in direct contact with the wall. We also analyze the dynamics of the filament contour length fluctuations in terms of effective polymerization (UU) and depolymerization (WW) rates, where again it is possible to disentangle non-ideal and confinement effects.Comment: 24 pages, 7 figure

    The thermodynamics of metabolism, cardiovascular performance and exercise, in health and diabetes: The objective of clinical markers

    Get PDF
    Extensive experience in UK National Health Service metabolic syndrome/type 2 diabetes clinics highlights the need for convenient clinical marker(s) which can be readily used to indicate the success or otherwise of alternative therapies. In this paper we study the metabolic context of the healthy and diseased states, which points to the haemodynamics being a possible key in identifying candidate markers. Human metabolism relates to two elemental thermodynamic systems, the individual cell and the human body in its entirety. The fundamental laws of thermodynamics apply to humans, animals, and their individual cells for both healthy and diseased conditions. as they are to classic heat engines. In compliance with the second law enhanced levels of heat are generated under exercise, heat itself being another factor modulating the cardiovascular response to physical exercise. Nutrients and oxygen uptake occurs via the digestive system and lungs, respectively, leading to ATP production by the established metabolic pathways: this is controlled by insulin. These are then delivered to the cells via the haemodynamic system to satisfy local metabolic need. The supply and demand of oxygen are finely regulated, in part, via oxygen-dependent release of ATP from the circulating erythrocytes. Energy supply and demand are regulated to sustain muscle activity resulting in the body’s output of measurable thermodynamic work—i.e. exercise. Recently a dynamic pathway model allowing quantification of ATP release from the erythrocytes and its contribution to oxygen supply regulation has been published. However, metabolic uptake is well known to be greatly affected by disease such as the highly prevalent diabetes type 2 with insulin resistance and beta cell dysfunction having mechanistic roles. In 2010, over 25% of residents above 65 in the USA had diabetes 2. The complexity of the metabolic pathways means that monitoring of patient-specific treatment would be beneficial from a diabetic marker which may be haemodynamic-related and traceable via the local fluid dynamics

    Regulation of actin in rat adrenocortical cells by corticotropin

    Get PDF
    Corticotropin (ACTH) induces a characteristic retraction of rat adrenocortical cells in culture. Densitometric analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of cell lysates showed that ACTH induced a 20% decrease in actin content. These results were fully confirmed by quantitation of actin by the DNase 1 inhibition assay. The decrease in actin is hormone-specific, concentration-dependent, and correlates temporally with the morphological change induced by ACTH. The change in actin content and the reorganization of microfilament ultrastructure may together mediate hormone regulation of cell shape at the cytoskeletal level

    Patterns of Treatment for Psychiatric Disorders Among Children and Adolesecents in Mississippi Medicaid

    Get PDF
    The nature of services for psychiatric disorders in public health systems has been understudied, particularly with regard to frequency, duration, and costs. The current study examines patterns of service reception and costs among Medicaid-covered youth newly diagnosed with anxiety, depression, or behavioral disturbance in a large data set of provider billing claims submitted between 2015–2016. Eligibility criteria included: 1) identification of an initial diagnosis of a single anxiety, unipolar mood, or specific behavioral disorder; 2) continuous Medicaid eligibility over the duration of the time period studied; and 3) under 18 years of age on the date of initial psychiatric diagnosis. The final cohort included 7,627 cases with a mean age of 10.65 (±4.36), of which 58.04% were male, 57.09% were Black, 38.97% were White, and 3.95% were of other ethnicities. Data indicated that 65.94% of the cohort received at least some follow-up services within a median 18 days of diagnosis. Of those, 54.27% received a combination of medical and psychosocial services, 32.01% received medical services only, and 13.72% received psychosocial services only. Overall median costs for direct treatment were 576.69,withwidediscrepanciesbetweenthelowest(anxiety=576.69, with wide discrepancies between the lowest (anxiety = 308.41) and highest (behavioral disturbance = $653.59) diagnostic categories. Across all categories the frequency and duration of psychosocial services were much lower than would be expected in comparison to data from a well-known effectiveness trial. Overall, follow-up to psychiatric diagnosis could be characterized as highly variable, underutilized, and emphasizing biomedical treatment. Understanding more about these patterns may facilitate systematic improvements and greater cost efficiency in the future

    Persistent activation of steroidogenesis in adrenocortical cells by photoaffinity labeling of corticotropin receptors

    Get PDF
    Photolysis of rat adrenocortical cells in the presence of the photoreactive derivative [(2-nitro-5-azidophenylsulfenyl)Trp9]-adrenocorticotropic hormone (2,5-NAPS-ACTH) at 24°C resulted in persistent activation of corticosterone production. The basal rate of steroidogenesis became maximal when photolysis was performed at 24°C but remained the same as that of control cells when irradiation was performed at 0°C. No increase in basal rate was observed with dark controls or cells photolyzed with [(2,4-dinitrophenylsulfenyl)Trp9]ACTH, a photoresistant analog of the hormone. Prephotolyzed 2,5-NAPS-ACTH failed to induce persistent activation. Both ACTH and 2,4-(dinitrophenylsulfenyl)Trp9-ACTH blocked the photo-induced activation of steroidogenesis elicited by 2,5-NAPS-ACTH. Under photolysis conditions which caused the basal rate of steroidogenesis to become maximal, a 3-fold increase in the basal rate of cAMP formation was observed
    corecore