271 research outputs found
Political opportunity structures, democracy, and civil war
Theories of mobilization suggest that groups are more likely to resort to violence in the presence of political opportunity structures that afford greater prospects for extracting concessions from the government or better opportunities to topple ruling governments. However, existing efforts to consider the possible influences of political opportunity structures on incentives for violence and civil war empirically have almost invariably relied upon measures of democracy to proxy for the hypothesized mechanisms, most notably the argument that the opposing effects of political accommodation and repression will give rise to an inverted U-shaped relationship between democracy and the risk of civil war. The authors detail a number of problems with measures of democracy as proxies for political opportunity structures and develop alternative measures based on the likely risks that political leaders will lose power in irregular challenges and their implications for the incentives for resort to violence. The authors evaluate empirically how the security with which leaders hold office influences the prospects of violent civil conflict. The findings indicate that recent irregular leader entry and transitions indeed increase the risk of conflict onset, while democratic institutions are found to decrease the risk of civil war, after controlling for the new measures of state weakness. </jats:p
New hyperekplexia mutations provide insight into glycine receptor assembly, trafficking, and activation mechanisms
Background: Hyperekplexia mutations have provided much information about glycine receptor structure and function. Results: Weidentified and characterized nine new mutations. Dominant mutations resulted in spontaneous activation, whereas recessive mutations precluded surface expression. Conclusion: These data provide insight into glycine receptor activation mechanisms and surface expression determinants. Significance: The results enhance our understanding of hyperekplexia pathology and glycine receptor structure-function. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A
Growth rates of the Mediterranean gecko, \u3ci\u3eHemidactylus turcicus\u3c/i\u3e, in southwestern Louisiana
We captured and marked Mediterranean geckos, Hemidactylus turcicus, occupying a one-story building in southwestern Louisiana in 1999–2000 and 2002–2005 and calculated 2 estimates of growth rate: length growth rate (difference in snout–vent length [SVL] between captures divided by time between captures) and mass growth rate (difference in gecko mass between captures divided by time between captures). Both length growth rate and mass growth rate were significantly negatively correlated with gecko snout–vent length. When data from all years were combined, adult female geckos showed greater mean length growth rates and mean mass growth rates than males, but the trend was not statistically significant. Length growth rate and mass growth rate varied dramatically between years; neither correlated with yearly differences in rainfall. Comparison of our results to studies done in Texas and Florida showed that Mediterranean geckos in Louisiana had the lowest mean length growth rates and a much wider range of variation.Capturamos y marcamos Gecos del Mediterráneo, Hemidactylus turcicus, que ocupaban un edificio de un piso en el suroeste de Louisiana en 1999 a 2000 y 2002 a 2005 y calculamos dos cálculos de tasas de crecimiento: La “Tasa de Crecimiento de Longitud” (la diferencia entre la longitud de hocico a cloaca entre capturas dividida por el periodo entre capturas) y la “Tasa de Crecimiento de Masa” (la diferencia entre la masa del geco entre capturas dividida por el periodo entre capturas). Las dos tasas tenían una correlación significantemente negativa con la longitud de hocico a cloaca del geco. Cuando combinamos los datos de todos los años, las hembras adultas de los gecos mostraron Tasas Medias de Crecimiento de Longitud y Tasas Medias de Crecimiento de Masa mayores que los machos, pero la tendencia no fue estadísticamente significativa. Las dos tasas variaron dramáticamente entre años; ninguna correlacionó fuertemente con las diferencias anuales en pluviosidad. Una comparación de nuestros resultados con estudios hechos en Texas y en Florida mostró que los gecos de Louisiana tenían Tasas Medias de Crecimiento de Longitud. Los gecos de Louisiana exhibieron una gama mucha más amplia de variación en Tasas de Crecimiento de Longitud
The dualistic role of Lyn tyrosine kinase in immune cell signaling: implications for systemic lupus erythematosus
Systemic lupus erythematosus (SLE, lupus) is a debilitating, multisystem autoimmune disease that can affect any organ in the body. The disease is characterized by circulating autoantibodies that accumulate in organs and tissues, which triggers an inflammatory response that can cause permanent damage leading to significant morbidity and mortality. Lyn, a member of the Src family of non-receptor protein tyrosine kinases, is highly implicated in SLE as remarkably both mice lacking Lyn or expressing a gain-of-function mutation in Lyn develop spontaneous lupus-like disease due to altered signaling in B lymphocytes and myeloid cells, suggesting its expression or activation state plays a critical role in maintaining tolerance. The past 30 years of research has begun to elucidate the role of Lyn in a duplicitous signaling network of activating and inhibitory immunoreceptors and related targets, including interactions with the interferon regulatory factor family in the toll-like receptor pathway. Gain-of-function mutations in Lyn have now been identified in human cases and like mouse models, cause severe systemic autoinflammation. Studies of Lyn in SLE patients have presented mixed findings, which may reflect the heterogeneity of disease processes in SLE, with impairment or enhancement in Lyn function affecting subsets of SLE patients that may be a means of stratification. In this review, we present an overview of the phosphorylation and protein-binding targets of Lyn in B lymphocytes and myeloid cells, highlighting the structural domains of the protein that are involved in its function, and provide an update on studies of Lyn in SLE patients
Cancer immunoediting by the innate immune system in the absence of adaptive immunity
Cancer immunoediting is the process whereby immune cells protect against cancer formation by sculpting the immunogenicity of developing tumors. Although the full process depends on innate and adaptive immunity, it remains unclear whether innate immunity alone is capable of immunoediting. To determine whether the innate immune system can edit tumor cells in the absence of adaptive immunity, we compared the incidence and immunogenicity of 3'methylcholanthrene-induced sarcomas in syngeneic wild-type, RAG2, and RAG2x γc mice. We found that innate immune cells could manifest cancer immunoediting activity in the absence of adaptive immunity. This activity required natural killer (NK) cells and interferon γ (IFN-γ), which mediated the induction of M1 macrophages. M1 macrophages could be elicited by administration of CD40 agonists, thereby restoring editing activity in RAG2x γc mice. Our results suggest that in the absence of adaptive immunity, NK cell production of IFN-γ induces M1 macrophages, which act as important effectors during cancer immunoediting
Structural and compositional variations of basic Cu(II) chlorides in the herbertsmithite and gillardite structure field.
© 2017 The Mineralogical Society. This document is the author’s final accepted version of the journal article. You are advised to consult the published version if you wish to cite from it
Vitamin D supplementation to prevent acute respiratory infections:systematic review and meta-analysis of stratified aggregate data
BackgroundA 2021 meta-analysis of 37 randomised controlled trials (RCTs) of vitamin D supplementation for prevention of acute respiratory infections (ARIs) revealed a statistically significant protective effect of the intervention (odds ratio [OR] 0·92 [95% CI 0·86 to 0·99]). Since then, six eligible RCTs have been completed, including one large trial (n=15 804). We aimed to re-examine the link between vitamin D supplementation and prevention of ARIs.MethodsUpdated systematic review and meta-analysis of data from RCTs of vitamin D for ARI prevention using a random effects model. Subgroup analyses were done to determine whether effects of vitamin D on risk of ARI varied according to baseline 25-hydroxyvitamin D (25[OH]D) concentration, dosing regimen, or age. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, and the ClinicalTrials.gov between May 1, 2020 (end-date of search of our previous meta-analysis) and April 30, 2024. No language restrictions were imposed. Double-blind RCTs supplementing vitamin D for any duration, with placebo or lower-dose vitamin D control, were eligible if approved by a Research Ethics Committee and if ARI incidence was collected prospectively and pre-specified as an efficacy outcome. Aggregate data, stratified by baseline 25(OH)D concentration and age, were obtained from study authors. The study was registered with PROSPERO (no. CRD42024527191).FindingsWe identified six new RCTs (19 337 participants). Data were obtained for 16 085 (83·2%) participants in three new RCTs and combined with data from 48 488 participants in 43 RCTs identified in our previous meta-analysis. For the primary comparison of any vitamin D versus placebo, the intervention did not statistically significantly affect overall ARI risk (OR 0·94 [95% CI 0·88–1·00], p=0·057; 40 studies; 61 589 participants; I2=26·4%). Pre-specified subgroup analysis did not reveal evidence of effect modification by age, baseline vitamin D status, dosing frequency, or dose size. Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (OR 0·96 [95% CI 0·90–1·04]; 38 studies; I2=0·0%). A funnel plot showed left-sided asymmetry (p=0·0020, Egger's test).InterpretationThis updated meta-analysis yielded a similar point estimate for the overall effect of vitamin D supplementation on ARI risk to that obtained previously, but the 95% CI for this effect estimate now includes 1·00, indicating no statistically significant protection
The Endogenous Economy: ‘Real’ Economic Conditions, Subjective Economic Evaluations and Government Support
The Perfect Finance Minister: Whom to Appoint as Finance Minister to Balance the Budget?
The role and influence of the finance minister within the cabinet are discussed with increasing prominence in the recent theoretical literature on the political economy of budget deficits. It is generally assumed that the spending ministers can raise their reputation purely with new or more extensive expenditure programs, whereas solely the finance minister is interested to balance the budget. Using a dynamic panel model to study the development of public deficits in the German states between 1960 and 2009, we identify several personal characteristics of the finance ministers that significantly influence budgetary performance. Namely her professional background seems to affect budget deficits. During times of fiscal stress, our results can guide prime ministers in the nominating of finance ministers in order to assure sound budgeting
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