Disability Status as an Unobservable: Estimates From a Structural Model

We propose an index of "true disability" by treating disability status as an unobservable phenomenon which is both causally related to a number of exogenous characteristics of an individual and correlated with a number of observed indicators of health, impairment and qualifications for employment. First, we define true disability and distinguish it from related concepts. We then discuss the importance of an objective and reliable measure of disability for research on the determinants of behavior. Next, we present the specification of our structural model for estimating true disability as a latent variable. Finally, we report the results of our estimation in a simple model of Labor force participation, and compare the effect of using the constructed index and a self-reported disability measure on understanding the determinants of behavior and choice.

Special Topic Forum on Supply Chain Management in Emerging Markets: Critical Research Issues

Spurred by the rapid development of international markets, w enhanced ease of communications and rapidly developing infrastructure, supply chains that transcend national boundaries have become standard in today's dynamic global environment, causing a number of critical research issues to emerge. The importance of such issues is intensified when considered in the unique environment faced by supply chains in emerging economies, such as Brazil, Russia, India and China. Traditional supply chain management practices may be ineffective, due to the unique characteristics of supply chains in emerging economies or that span developed and emerging economies. In this special topic forum, we seek high quality conceptual and empirical research that addresses critical research issues related to managing supply chains in emerging economies. Conceptual papers should draw upon and extend existing theoretical foundations, developing models and propositions for future research. Empirical research studies that employ survey methodology, structured case research, secondary data analysis, controlled experiments and other empirical approaches are welcomed. In line with JSCM's mission statement, authors must clearly identify how their work extends or contributes to theory relating to global supply chain management, as well as providing implications for practice

A cross-cultural examination of the relationships among human resource management practices and organisational commitment: an institutional collectivism perspective

Previous research has shown that human resource management (HRM) practices vary across cultures. However, little research has empirically compared the effects of various HRM practices on firm-level or individual-level outcome variables across cultures. Drawing upon psychological contract theory and the literature on cultural values, the present study examined the effects of three organisational-level HRM practices on individual organisational commitment in a survey of 2424 individuals in 120 organisations located in four countries and three industries. Based upon the GLOBE study, we classified the four countries into two groups – high versus low institutional collectivism. The results of our hierarchical linear modelling (HLM) analyses found significant differences in the effects of organisational-level HRM on individual organisational commitment across cultures for two of the three HRM practices included in our model: training and teamwork. We also found partial support for differences across cultures for the effects of the third HRM practice: employee involvement in decision making. Overall, our results support the utility of theoretical and empirical models that address multiple levels of analyses to better understand the mechanisms through which the HRM-performance link takes place across national cultures

Development of mucoadhesive sprayable gellan gum fluid gels

The nasal mucosa provides a potentially good route for local and systemic drug delivery. However, the protective feature of the nasal cavity make intranasal delivery challenging. The application of mucoadhesive polymers in nasal drug delivery systems enhances the retention of the dosage form in the nasal cavity. Several groups have investigated using low acyl gellan as a drug delivery vehicle but only limited research however, has been performed on high acyl gellan for this purpose, despite its properties being more conducive to mucoadhesion. High acyl gellan produces highly elastic gels below 60 °C which make it difficult to spray using a mechanical spray device. Therefore, in this study we have tried to address this problem by making fluid gels by introducing a shear force during gelation of the gellan polymer. These fluid gel systems contain gelled micro-particles suspended in a solution of un-gelled polymer. These systems can therefore behave as pourable viscoelastic fluids. In this study we have investigated the rheological behavior and mucoadhesion of fluid gels of two different types of gellan (high and low acyl) and fluid gels prepared from blends of high and low acyl gellan at a 50:50 ratio. The results demonstrated that by preparing fluid gels of high acyl gellan, the rheological properties were sufficient to spray through a standard nasal spray device. Moreover fluid gels also significantly enhance both high acyl and low acyl gellan mucoadhesion properties

An optical coherence microscope for 3-dimensional imaging in developmental biology

An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument

Rat mesangial cell hypertrophy in response to transforming growth factor-β1

Rat mesangial cell hypertrophy in response to transforming growth factor-β1. Central features of progressive glomerular sclerosis are initial glomerular hypertrophy and subsequent accumulation of extracellular matrix proteins. Since TGF-β1 may play a key role in this glomerular response to injury, the present study sought to explore further TGF-β1 actions and regulated expression of its receptor in rat mesangial cells. The rat TGF-β type II receptor (TGF-βRII) homolog was cloned by screening a rat kidney cDNA library with a human TGF-βRII cDNA probe, and sequenced. Expression of this receptor subtype in rat mesangial cells was then demonstrated by RNase protection assay, and by Northern blot analysis of poly (A)+ RNA, TGF-βRII expression was down-regulated in cells treated with exogenous TGF-β1. Affinity cross linking studies demonstrated presence of this receptor on cell surface. Rat mesangial cells also expressed TGF-β1 and autoinduction by TGF-β1 was observed in the same cells, suggesting that this polypeptide may act in an autocrine fashion on mesangial cells, and that it may stimulate a positive autoamplification loop. TGF-β1 inhibited mesangial cell proliferation and stimulated significant overall protein and collagen production. Furthermore, mesangial cell size increased in response to chronic TGF-β1 treatment. These findings demonstrate that rat mesangial cells express key components of the TGF-β system and raise the intriguing possibility that in the glomerular mesangium, TGF-β1 may not only induce extracellular matrix synthesis, but may also participate in the process of glomerular hypertrophy in response to injury

Dietary Shiitake mushroom (Lentinus edodes) prevents fat deposition and lowers triglyceride in rats fed a high-fat diet

High-fat diet (HFD) induces obesity. This study examined the effects of Shiitake mushroom on the prevention of alterations of plasma lipid profiles, fat deposition, energy efficiency, and body fat index induced by HFD. Rats were given a low, medium, and high (7, 20, 60 g/kg = LD-M, MD-M, HD-M) Shiitake mushroom powder in their high-fat (50% in kcal) diets for 6 weeks. The results showed that the rats on the HD-M diet had the lowest body weight gain compared to MD-M and LD-M groups (P \u3c 0.05). The total fat deposition was significantly lower (-35%, P \u3c 0.05) in rats fed an HD-M diet than that of HFD group. Interestingly, plasma triacylglycerol (TAG) level was significantly lower (-55%, P \u3c 0.05) in rats on HD-M than HFD. This study also revealed the existence of negative correlations between the amount of Shiitake mushroom supplementation and body weight gain, plasma TAG, and total fat masses

Rescue of a genotype 4 human hepatitis E virus from cloned cDNA and characterization of intergenotypic chimeric viruses in cultured human liver cells and in pigs

Hepatitis E virus (HEV) is an important but extremely understudied human pathogen. Genotypes 1 and 2 are restricted to humans, whereas genotypes 3 and 4 are zoonotic, infecting both humans and pigs. This report describes, for the first time, the successful rescue of infectious HEV in vitro and in vivo from cloned cDNA of a genotype 4 human HEV (strain TW6196E). The complete genomic sequence of the TW6196E virus was determined and a full-length cDNA clone (pHEV-4TW) was assembled. Capped RNA transcripts from the pHEV-4TW clone were replication competent in Huh7 cells and infectious in HepG2/C3A cells. Pigs inoculated intrahepatically with capped RNA transcripts from pHEV-4TW developed an active infection, as evidenced by faecal virus shedding and seroconversion, indicating the successful rescue of infectious genotype 4 HEV and cross-species infection of pigs by a genotype 4 human HEV. To demonstrate the utility of the genotype 4 HEV infectious clone and to evaluate the potential viral determinant(s) for species tropism, four intergenotypic chimeric clones were constructed by swapping various genomic regions between genotypes 1 and 4, and genotypes 1 and 3. All four chimeric clones were replication competent in Huh7 cells, but only the two chimeras with sequences swapped between genotypes 1 and 4 human HEVs produced viruses capable of infecting HepG2/C3A cells. None of the four chimeras was able to establish a robust infection in pigs. The availability of a genotype 4 HEV infectious clone affords an opportunity to delineate the molecular mechanisms of HEV cross-species infection in the future

Gut microbiota regulates K/BxN autoimmune arthritis through Tfh but not Th17 cells

The bacterial community that colonizes mucosal surfaces helps shape the development and function of the immune system. The K/BxN autoimmune arthritis model is dependent on the microbiota, and particularly on segmented filamentous bacteria, for the autoimmune phenotype. The mechanisms of how the gut microbiota affects arthritis development are not well understood. In this study, we investigate the contribution of two T cell subsets, Th17 and follicular helper T (Tfh), to arthritis and how microbiota modulates their differentiation. Using genetic approaches, we demonstrate that IL-17 is dispensable for arthritis. Antibiotic treatment inhibits disease in IL-17-deficient animals, suggesting that the gut microbiota regulates arthritis independent of Th17 cells. In contrast, conditional deletion of Bcl6 in T cells blocks Tfh cell differentiation and arthritis development. Furthermore, Tfh cell differentiation is defective in antibiotic-treated mice. Taken together, we conclude that gut microbiota regulates arthritis through Tfh but not Th17 cells. These findings have implications in our understanding of how environmental factors contribute to the development of autoimmune diseases