1,456 research outputs found
Asserting and transcending ethnic homophily: how entrepreneurs develop social ties to access resources and opportunities in socially contested environments
Research Summary In socially contested settings, it is often difficult to connect with (diverse) others, and it is unclear how entrepreneurs in these contexts may develop the social ties that previous research has shown to be valuable. We studied this subject matter in Kenya, an ethnically fractionalized society that recently experienced the decentralization of government, which required entrepreneurs to deal with both in-group and out-group ethnicities. We conducted an inductive case study of four Nairobi-based companies and captured the creative tactics that they used to transcend ethnic homophily (by defocusing from ethnicity and reframing the in-group) while also asserting ethnic homophily (by signaling tribal affiliation and leveraging others' ethnicity). We contribute to a deeper understanding of how and why entrepreneurs in socially contested settings develop social ties. Managerial Summary Entrepreneurs in socially contested settings rely on social networks to access resources and opportunities. However, it is unclear how entrepreneurs in these settings develop and use these networks. We studied this question in an ethnically fractionalized setting that recently experienced the decentralization of government: Kenya. Entrepreneurs who previously provided information technology (IT) services to the central government had to deal with both own-tribe and other-tribe contacts to receive new contracts. We studied four Nairobi-based IT firms that operated across a variety of counties and analyzed the creative tactics that entrepreneurs in this context use to cross ethnic divides while also working with own-tribe contacts. This contributes to our collective understanding of how and why entrepreneurs in socially contested settings develop diverse social ties to access resources and opportunities
MHC class II protein turnover in vivo and its relevance for autoimmunity in non-obese diabetic mice
Major histocompatibility complex class II (MHCII) proteins are loaded with endosomal peptides and reside at the surface of antigen-presenting cells (APCs) for a time before being degraded. In vitro, MHCII protein levels and turnover are affected by peptide loading and by rates of ubiquitin-dependent internalization from the cell surface, which is in turn affected by APC type and activation state. Prior work suggested that fast turnover of disease-associated MHCII alleles may contribute to autoimmunity. We recently developed novel stable isotope tracer techniques to test this hypothesis in vivo. In non-obese diabetic (NOD) mice, a model of type 1 diabetes (T1D), MHCII turnover was affected by APC type, but unaffected by disease-associated structural polymorphism. Differences in MHCII turnover were observed between NOD colonies with high and low T1D incidence, but fast turnover was dispensable for autoimmunity. Moreover, NOD mice with gene knockouts of peptide loading cofactors do not develop T1D. Thus, fast turnover does not appear pathogenic, and conventional antigen presentation is critical for autoimmunity in NOD mice. However, shared environmental factors may underpin colony differences in MHCII protein turnover, immune regulation, and pathogenesis
Integrating the Language Arts for Primary-Age Disabled Readers
Children who attended the University of Missouri Child Study Clinic had an opportunity to participate in a program of reading instruction based upon a theory of the reading process developed by Kenneth S. Goodman. Goodman viewed reading as a meaning seeking process which has two characteristics. One is that the reader is attempting to get at meaning. The second is that he or she is using whole language to do so (Brenner, 1976). This whole-language comprehension-centered approach to the teaching of reading is rooted in the belief that children learn to read in as natural a way as they learn to speak
HLA associations in inflammatory arthritis: emerging mechanisms and clinical implications
Our understanding of the mechanisms underlying HLA associations with inflammatory arthritis continues to evolve. Disease associations have been refined, and interactions of HLA genotype with other genes and environmental risk factors in determining disease risk have been identified. This Review provides basic information on the genetics and molecular function of HLA molecules, as well as general features of HLA associations with disease. Evidence is discussed regarding the various peptide-dependent and peptide-independent mechanisms by which HLA alleles might contribute to the pathogenesis of three types of inflammatory arthritis: rheumatoid arthritis, spondyloarthritis and systemic juvenile idiopathic arthritis. Also discussed are HLA allelic associations that shed light on the genetic heterogeneity of inflammatory arthritides and on the relationships between adult and paediatric forms of arthritis. Clinical implications range from improved diagnosis and outcome prediction to the possibility of using HLA associations in developing personalized strategies for the treatment and prevention of these diseases
Lack of Cross-Reactivity Allergy Following a Switch from Alirocumab to Evolocumab
The proprotein convertase subtilisin/kexin type 9 (PCSK9) gene and gain-of-function mutations were first described in 2003. The gain-of-function mutations observed were associated with low-density lipoprotein-cholesterol (LDL-C) levels in the 400’s, in addition to premature cardiovascular disease. Subsequent loss-of-function experiments conducted in mice demonstrated marked reductions in plasma cholesterol levels in the absence of PCSK9. Physiologically, PCSK9 serves as a chaperone protein and functions to reduce low-density lipoprotein (LDL) receptor recycling; consequently, less LDL-C is removed from circulation and serum lipid concentrations become elevated. Inhibition of PCSK9 prevents LDL receptor degradation and preserves receptor recycling to the hepatocyte surface; this in turn results in reduced LDL-C levels. We report a lack of cross-sensitivity following the administration of evolocumab after an allergic reaction to alirocumab
Modeling Gully Erosion Susceptibility to Evaluate Human Impact on a Local Landscape System in Tigray, Ethiopia
In recent years, modeling gully erosion susceptibility has become an increasingly popular approach for assessing the impact of different land degradation factors. However, different forms of human influence have so far not been identified in order to form an independent model. We investigate the spatial relation between gully erosion and distance to settlements and footpaths, as typical areas of human interaction, with the natural environment in rural African areas. Gullies are common features in the Ethiopian Highlands, where they often hinder agricultural productivity. Within a catchment in the north Ethiopian Highlands, 16 environmental and human-related variables are mapped and categorized. The resulting susceptibility to gully erosion is predicted by applying the Random Forest (RF) machine learning algorithm. Human-related and environmental factors are used to generate independent susceptibility models and form an additional inclusive model. The resulting models are compared and evaluated by applying a change detection technique. All models predict the locations of most gullies, while 28% of gully locations are exclusively predicted using human-related factors
Management Policy in Franchising Operations: A Preliminary Study
During the past few decades franchising has emerged as one of the fastest growing methods doing business in the world . This article investigates the concept of climate in Franchising ores and how that relates to the stores' per formance. Work context, participation and orkgrou p were identified as important climate factors influencing store per formance: Pro r management .of the work climate should e.nhance Franchise store per formance.
Pre- and post-operative assessment of valvular and aortic flow using 4D flow magnetic resonance imaging
Risk factors for COPD exacerbations in inhaled medication users: the COPDGene study biannual longitudinal follow-up prospective cohort.
BackgroundDespite inhaled medications that decrease exacerbation risk, some COPD patients experience frequent exacerbations. We determined prospective risk factors for exacerbations among subjects in the COPDGene Study taking inhaled medications.Methods2113 COPD subjects were categorized into four medication use patterns: triple therapy with tiotropium (TIO) plus long-acting beta-agonist/inhaled-corticosteroid (ICS ± LABA), tiotropium alone, ICS ± LABA, and short-acting bronchodilators. Self-reported exacerbations were recorded in telephone and web-based longitudinal follow-up surveys. Associations with exacerbations were determined within each medication group using four separate logistic regression models. A head-to-head analysis compared exacerbation risk among subjects using tiotropium vs. ICS ± LABA.ResultsIn separate logistic regression models, the presence of gastroesophageal reflux, female gender, and higher scores on the St. George's Respiratory Questionnaire were significant predictors of exacerbator status within multiple medication groups (reflux: OR 1.62-2.75; female gender: OR 1.53 - OR 1.90; SGRQ: OR 1.02-1.03). Subjects taking either ICS ± LABA or tiotropium had similar baseline characteristics, allowing comparison between these two groups. In the head-to-head comparison, tiotropium users showed a trend towards lower rates of exacerbations (OR = 0.69 [95 % CI 0.45, 1.06], p = 0.09) compared with ICS ± LABA users, especially in subjects without comorbid asthma (OR = 0.56 [95% CI 0.31, 1.00], p = 0.05).ConclusionsEach common COPD medication usage group showed unique risk factor patterns associated with increased risk of exacerbations, which may help clinicians identify subjects at risk. Compared to similar subjects using ICS ± LABA, those taking tiotropium showed a trend towards reduced exacerbation risk, especially in subjects without asthma.Trial registrationClinicalTrials.gov NCT00608764, first received 1/28/2008
Impact of confinement and polarizability on dynamics of ionic liquids
Polarizability is a key factor when it comes to an accurate description of different ionic systems. The general importance of including polarizability into molecular dynamics simulations was shown in various recent studies for a wide range of materials, ranging from proteins to water to complex ionic liquids and for solid–liquid interfaces. While most previous studies focused on bulk properties or static structure factors, this study investigates in more detail the importance of polarizable surfaces on the dynamics of a confined ionic liquid in graphitic slit pores, as evident in modern electrochemical capacitors or in catalytic processes. A recently developed polarizable force field using Drude oscillators is modified in order to describe a particular room temperature ionic liquid accurately and in agreement with recently published experimental results. Using the modified parameters, various confinements are investigated and differences between non-polarizable and polarizable surfaces are discussed. Upon introduction of surface polarizability, changes in the dipole orientation and in the density distribution of the anions and cations at the interface are observed and are also accompanied with a dramatic increase in the molecular diffusivity in the contact layer. Our results thus clearly underline the importance of considering not only the polarizability of the ionic liquid but also that of the surface
- …