566 research outputs found
The Fragile Definition of State Fragility
We investigates the link between fragility and economic development in sub-Saharan Africa over a
yearly panel including 28 countries for the 1999-2004 period. Beside the conventional definition of
fragility adopted by the OECD Development Assistance Committee, we introduce the more severe
definition of extreme fragility. We show that only the latter exerts a significantly negative impact on
economic development, once standard economic, demographic, and institutional regressors are
accounted for. As a by-product of this investigation we produce up-to-date evidence on the growth
performance of the area. We find a tendency to convergence and no influence of geographic and
historical factors
De Jure and de Facto Determinants of Power: Evidence from Mississippi
We evaluate the empirical relevance of de facto vs. de jure determinants of political power in the U.S. South between the end of the nineteenth and the beginning of the twentieth century. We apply a variety of estimation techniques to a previously unexploited dataset on voter registration by race covering the counties of Mississippi in 1896, shortly after the introduction of the 1890 voting restrictions encoded in the state constitution. Our results indicate that de jure voting restrictions reduce black registration but that black disfranchisement starts well before 1890 and is more intense where a black majority represents a threat to the de facto power of white elites. Moreover, the effect of race becomes stronger after 1890 suggesting that the de jure barriers may have served the purpose of institutionalizing a de facto condition of disfranchisement
Growth, History, or Institutions? What Explains State Fragilityin Sub-Saharan Africa
We explore the determinants of state fragility in sub-Saharan Africa. Controlling for a wide range of
economic, demographic, geographic and istitutional regressors, we find that institutions, and in
particular the civil liberties index and the number of revolutions, are the main determinants of
fragility, even taking into account their potential endogeneity. Economic factors such as income
growth and investment display a non robust impact after controlling for omitted variables and
reverse causality. Colonial variables reflecting the history of the region display a marginal impact
on fragility once institutions are accounted for
Variations in porcine colostrum oligosaccharide composition between breeds and in association with sow maternal performance
Background: Oligosaccharides (OS) are indigestible carbohydrates naturally found in milk. The composition of porcine colostrum OS may influence the growth and the health of the neonate and consuming optimal concentrations of OS may reduce piglet susceptibility to illness. In this manner, targeted supplementation of animal feed with OS is being explored as a health management tool in the livestock industry. The variation in OS composition between different breeds of pig and its association with the litter performance is currently unknown. The aim of this study was to characterize the colostrum OS composition from sows of different breed and parity and correlate this data with sow maternal traits. Methods: Eighty-three colostrum samples from parities 1 to 8 were gathered from 3 different breeds of sow: 44 Large White sows, 27 Landrace sows and 12 Duroc sows. Samples were taken between the birth of the first and the last piglet from sows that were not pharmacologically induced to farrow. OS were purified from the samples and analysed by MALDI-ToF mass spectrometry (21 OS compositions detected). The farrowing season and the maternal data were recorded for each sow, including the number of live piglets and the litter body weight at birth, at day (d) 3 and at weaning. Results: Five OS compositions, including isomers of the bifidogenic Sialyllactose, Lacto-N-Tetraose and Lacto-N-Hexaose series, were detected in all the samples. Twelve other OS were identified in at least 50% of samples, and their abundances were affected by breed (P < 0.05; 6 of 12), marginally affected by season (P < 0.10; 3 of 12) and never by parity number. The abundances of each OS component were standardized by Z-score scaling (\u3bc = 0 and SD = 1), transformed by principal component analysis, and four similarity clusters were generated. Cluster membership was associated with litter weight gain within 3 days (P = 0.063) and at weaning (P < 0.05), but not with piglet mortality within 3 days. Conclusions: OS composition of colostrum may partially explain the variability in maternal performance within and between different breeds of sow. The obtained OS data can provide useful information for the development of novel prebiotic food supplements for suckling and weaning pigs
Uncovering the physiological mechanisms underlying the roe deer (Capreolus capreolus) testicular cycle: Analyses of gelatinases and VEGF patterns and correlation with testes weight and testosterone
The roe deer (Capreolus capreolus) represents a spontaneous model of testicular inactivation: During winter, bucks show a suspension of spermatogenesis that starts again in spring and peaks during the breeding season (July\u2013August). The underlying mechanisms to the regulation of the cyclic testicular changes are still not fully clear but seem to be imputable to the spermatogenic cell line since other testicular cell populations remain stable without apoptotic phenomena. The aim of the study was to investigate apoptosis, gelatinases (MMP2 and 9), their inhibiting factors (TIMP 1-2), and two isoforms of vascular endothelial growth factor (VEGF121 and 165) with its receptors (VEGFR1-2) in testes collected during pre-and post-rut periods, and to correlate them with testicular weight (TW) and testosterone (TEST). Testes from 18 adult sexually mature bucks were collected in Bologna Apennines (Italy). Samples were weighed and parenchyma collected. Radioimmunoassay, real-time PCR, and zymography were performed. The results showed a post-rut decrease in TW and TEST and an increase in proMMP2, also highlighting a correlation between the gelatinases and the testicular functionality. The VEGF pattern did not show modifications nor correlation with TW and TEST. Overall, gelatinases and their inhibitors, described herein for the first time in roe deer testes, seem to play an important role in the testicular cycle
Exploring differential transcriptome between jejunal and cecal tissue of broiler chickens
Simple Summary: Intestinal main functions and different gut tract peculiarities in poultry are known. However, a wider view at the molecular level in terms of functional genes may contribute to deepening knowledge on less considered biological aspects, with possible differentiation in gene expression and functionality between gut tracts. This experiment aimed to extend the exploration of chicken gut functional aspects by scouting differential gene expression in the jejunum and cecum, which may help in the detection of new interesting functions from a biological point of view. The work identified key aspects linked to gut biological processes that may be worthy of further investigations in experimental studies considering factors which may specifically address peculiarities of the different chicken gut tracts at the molecular level. Abstract: The study proposed an exploratory functional analysis on differential gene expression of the jejunum and of cecum in chickens. For this study, 150 Ross 308 male chickens were randomly allotted in six pens (25 birds/pen) and fed the same commercial diet. From 19 birds of 42 days of age, jejunum and cecum mucosae were collected for RNA extraction for transcriptome microarray analysis. Differentially expressed genes (DEGs) submitted to DAVID (Database for Annotation, Visualization, and Integrated Discovery) and Gene Set Enrichment Analysis (GSEA) software evidenced enriched gene clusters for biological functions differentiated in the tissues. DAVID analysis in the jejunum showed enriched annotations for cell membrane integral components, PPAR (peroxisome proliferator-activated receptor) signaling pathway, and peroxisome and lipid metabolism, and showed DEGs for gluconeogenesis, not previously reported in chicken jejunum. The cecum showed enriched annotations for disulfide bond category, cysteine and methionine metabolism, glycoprotein category, cell cycle, and extracellular matrix (ECM). GSEA analysis in the jejunum showed peroxisome and PPAR signaling pathway-related gene sets, as found with DAVID, and gene sets for immune regulation, tryptophan and histidine metabolism, and renin\u2013angiotensin system, like in mammals. The cecum showed cell cycle and regulation processes, as well as ECM receptor interaction and focal adhesion-related gene sets. Typical intestinal functions specific for the gut site and interesting functional genes groups emerged, revealing tissue-related key aspects which future studies might take advantage of
Double parton scatterings in high energy hadronic collisions
CDF has recently measured a large number of double parton scatterings. The
observed value of , the non perturbative parameter which
characterizes the process, is considerably smaller as compared with the naive
expectation. The small value of is likely to be an indication of
the importance of the two-body parton correlations in the many-body parton
distributions of the proton.Comment: 8 pages, latex file, no figures, contributions to the proceedings of
the ISMD9
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