1,398 research outputs found

    The Benefits of Multilateral Aid: How Agency Motivation, Specialization, and Autonomy Promote Development

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    The question of how to enhance the effectiveness of foreign aid has plagued researchers for over six decades. Although in some cases scholars have positive support regarding aid’s impact on economic growth in recipient countries, others have questioned these findings, and some have even demonstrated that aid has a negative impact on growth. I address this question from a new perspective by analyzing how the organizational characteristics of aid agencies lead to differences in development policies. Specifically, I highlight how the characteristics of an understudied group of agencies, multilateral aid agencies, impact their effectiveness. I demonstrate my argument by collecting original qualitative and quantitative data on three variables related to organizational performance. I then empirically test my expectations through a series of panel analyses of aid and economic growth from 1973-2012. The results support my theoretical expectations that organizational differences matter in terms of the outcomes they produce. I argue that three specific organizational characteristics enhance multilateral aid effectiveness: motivation, specialization, and autonomy. Agency motivations matter because they impact aid allocation patterns, which are critical for distributing effective aid. Specialization allows the agency to provide more funding to each of their targets, reduce transaction costs, and implement knowledgeable and effective policies. Autonomy determines the ability of the agency to resist attempts to pressure them to distribute politically driven aid. In order to test these arguments, I present original data documenting the motivations, specialization, and autonomy of forty multilateral agencies. I test my arguments using estimation techniques robust to issues of endogeneity and instrumentation that have hampered past research. My results support my argument. Generally, bilateral aid is found to be less effective than multilateral aid. Furthermore, I demonstrate that differences within multilateral aid agencies exist as well, and show how more autonomous agencies are comparatively more effective. I find little support, however, for my expectation regarding agency specialization, suggesting a fruitful avenue for future research. My results are able to account for past discrepancies within the aid literature, provide strong policy prescriptions for the aid community, and lend support for the salience of international organizations

    The molecular basis for recognition of bacterial ligands at equine TLR2, TLR1 and TLR6.

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    TLR2 recognises bacterial lipopeptides and lipoteichoic acid, and forms heterodimers with TLR1 or TLR6. TLR2 is relatively well characterised in mice and humans, with published crystal structures of human TLR2/1/Pam3CSK4 and murine TLR2/6/Pam2CSK4. Equine TLR4 is activated by a different panel of ligands to human and murine TLR4, but less is known about species differences at TLR2. We therefore cloned equine TLR2, TLR1 and TLR6, which showed over 80% sequence identity with these receptors from other mammals, and performed a structure-function analysis. TLR2/1 and TLR2/6 from both horses and humans dose-dependently responded to lipoteichoic acid from Staphylococcus aureus, with no significant species difference in EC50 at either receptor pair. The EC50 of Pam2CSK4 was the same for equine and human TLR2/6, indicating amino acid differences between the two species' TLRs do not significantly affect ligand recognition. Species differences were seen between the responses to Pam2CSK4 and Pam3CSK4 at TLR2/1. Human TLR2/1, as expected, responded to Pam3CSK4 with greater potency and efficacy than Pam2CSK4. At equine TLR2/1, however, Pam3CSK4 was less potent than Pam2CSK4, with both ligands having similar efficacies. Molecular modelling indicates that the majority of non-conserved ligand-interacting residues are at the periphery of the TLR2 binding pocket and in the ligand peptide-interacting regions, which may cause subtle effects on ligand positioning. These results suggest that there are potentially important species differences in recognition of lipopeptides by TLR2/1, which may affect how the horse deals with bacterial infections.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Afadin orients cell division to position the tubule lumen in developing renal tubules

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    In many types of tubules, continuity of the lumen is paramount to tubular function, yet how tubules generate lumen continuity in vivo is not known. We recently found the F-actin binding protein Afadin is required for lumen continuity in developing renal tubules, though its mechanism of action remains unknown. Here we demonstrate Afadin is required for lumen continuity by orienting the mitotic spindle during cell division. Using an in vitro 3D cyst model, we find Afadin localizes to the cell cortex adjacent to the spindle poles and orients the mitotic spindle. In tubules, cell division may be oriented relative to two axes, longitudinal and apical-basal. Unexpectedly, in vivo examination of early stage developing nephron tubules reveals cell division is not oriented in the longitudinal (or planar polarized) axis. However, cell division is oriented perpendicular to the apical-basal axis. Absence of Afadin in vivo leads to misorientation of apical-basal cell division in nephron tubules. Together these results support a model whereby Afadin determines lumen placement by directing apical-basal spindle orientation, which generates a continuous lumen and normal tubule morphogenesis

    A Systematic Review of the Effectiveness of Children’s Behavioral Health Interventions in Psychiatric Residential Treatment Facilities

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    Objective The purpose of this systematic review was to synthesize quantitative or mixed-method studies that evaluate the efficacy of interventions with youth in the context of psychiatric residential treatment facilities (PRTFs) in the United States. Methods Systematic review procedures were conducted to identify relevant studies, both published and from the gray literature in the United States. Search terms were informed via consultation with a university social science reference librarian, and four electronic databases were searched. Using a priori inclusion and exclusion criteria, team-based search procedures yielded a final sample of 47 relevant studies. Results Studies varied with respect to publication status; sample size; research design; youth gender identity; youth racial/ethnic identity; youth behavioral, psychological, and developmental or intellectual concerns at intake; outcomes measures; and interventions evaluated. Evaluated interventions could be clustered into one of five categories: (a) modifications to system of treatment, (b) therapeutic modalities, (c) educational/alternative programs, (d) practice behaviors, and (e) post-discharge engagement. The majority of studies noted youth outcome improvements; however, some studies also yielded mixed, inconclusive, or null results. Conclusions We would characterize the breadth and depth of research in this area to be insufficient in providing PRTF stakeholders a clear and firm understanding of “what works” for youth. Thus, one major implication of our review is the need for more research and efforts to incentivize the evaluation of ongoing practices in youth PRTFs. Still, this systematic review can serve as a convenient reference that can inform tentatively PRTF stakeholders’ decisions about the selection of interventions or practice behaviors

    A map of white matter tracts in a lesser ape, the lar gibbon

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    The recent development of methods for constructing directly comparable white matter atlases in primate brains from diffusion MRI allows us to probe specializations unique to humans, great apes, and other primate taxa. Here, we constructed the first white matter atlas of a lesser ape using an ex vivo diffusion-weighted scan of a brain from a young adult (5.5 years) male lar gibbon. We find that white matter architecture of the gibbon temporal lobe suggests specializations that are reminiscent of those previously reported for great apes, specifically, the expansion of the arcuate fasciculus and the inferior longitudinal fasciculus in the temporal lobe. Our findings suggest these white matter expansions into the temporal lobe were present in the last common ancestor to hominoids approximately 16 million years ago and were further modified in the great ape and human lineages. White matter atlases provide a useful resource for identifying neuroanatomical differences and similarities between humans and other primate species and provide insight into the evolutionary variation and stasis of brain organization

    Identification of key residues that confer Rhodobacter sphaeroides LPS activity at horse TLR4/MD-2.

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    The molecular determinants underpinning how hexaacylated lipid A and tetraacylated precursor lipid IVa activate Toll-like receptor 4 (TLR4) are well understood, but how activation is induced by other lipid A species is less clear. Species specificity studies have clarified how TLR4/MD-2 recognises different lipid A structures, for example tetraacylated lipid IVa requires direct electrostatic interactions for agonism. In this study, we examine how pentaacylated lipopolysaccharide from Rhodobacter sphaeroides (RSLPS) antagonises human TLR4/MD-2 and activates the horse receptor complex using a computational approach and cross-species mutagenesis. At a functional level, we show that RSLPS is a partial agonist at horse TLR4/MD-2 with greater efficacy than lipid IVa. These data suggest the importance of the additional acyl chain in RSLPS signalling. Based on docking analysis, we propose a model for positioning of the RSLPS lipid A moiety (RSLA) within the MD-2 cavity at the TLR4 dimer interface, which allows activity at the horse receptor complex. As for lipid IVa, RSLPS agonism requires species-specific contacts with MD-2 and TLR4, but the R2 chain of RSLA protrudes from the MD-2 pocket to contact the TLR4 dimer in the vicinity of proline 442. Our model explains why RSLPS is only partially dependent on horse TLR4 residue R385, unlike lipid IVa. Mutagenesis of proline 442 into a serine residue, as found in human TLR4, uncovers the importance of this site in RSLPS signalling; horse TLR4 R385G/P442S double mutation completely abolishes RSLPS activity without its counterpart, human TLR4 G384R/S441P, being able to restore it. Our data highlight the importance of subtle changes in ligand positioning, and suggest that TLR4 and MD-2 residues that may not participate directly in ligand binding can determine the signalling outcome of a given ligand. This indicates a cooperative binding mechanism within the receptor complex, which is becoming increasingly important in TLR signalling.This work was supported by a project grant from the Horserace Betting Levy Board to CEB and a Horserace Betting Levy Board Veterinary Research Training Scholarship to KLI. This work was also supported by a Wellcome Trust program grant to NJG and CEB. CEB is a BBSRC Research Development Fellow.This is the final version of the article. It first appeared from PLOS at http://dx.doi.org/10.1371/journal.pone.0098776

    In vitro models of the liver : disease modeling, drug discovery and clinical applications

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    In vitro models of the liver have led to important insights into the pathogenesis of liver disease. These models are essential tools in the discovery and preclinical stages of drug development. The clinical application of these models is also emerging as a promising avenue for validating genetic target-matched treatments, in a precision medicine approach to treatment. Recent advances in ‘liver-on-a-chip’ technology and liver organoid research have opened up new opportunities for the functional and clinical use of organotypic in vitro models. This chapter focuses on the currently available in vitro liver models and the opportunities and limitations they present in the context of evaluating their use in disease modeling, drug discovery, and clinical application

    Improving mouse-DMH screening capability by adding 2000 mouse CpG islands

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    Abstract only availableDNA methylation alteration, in correlation with gene expression, is involved in development and progression of many cancers. Using a microarray based method, mouse-DMH (Differential Methylation Hybridization), our lab is able to study DNA methylation changes during prostate cancer progression in the TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mouse model. Currently, there are about 3000 CpG islands on the microarray, which were used as probes to detect DNA methylation changes. In order to improve our ability to screen for a larger number of CpG island methylation changes, we are working on adding about 2000 more mouse CpG islands onto the array. In addition, we have successfully designed primers and PCR amplified CpG islands for tumor suppressor genes and proto-oncogenes which have been previously reported in literature to be differentially methylated during development of human prostate cancer. These genes include AR (Androgen Receptor), ER (Estrogen Receptor alpha), ER(Estrogen Receptor beta) and GSTP1 (Glutathione S-Transferase PI). Primer design and PCR amplification for other known tumor suppressors/oncogenes is still in process. The microarray-based mouse-DMH is a tool of great potential. It can easily be adapted to screen for DNA methylation changes in other mouse cancer models and generate valuable data leading to understanding of the molecular mechanism behind cancer development, which will in turn contribute to treatment of human cancers.NSF-REU Biology & Biochemistr
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