843 research outputs found

    Immigrant entrepreneurs, diasporas, and exports

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    This paper demonstrates the positive effect of immigrant entrepreneurs on manufacturing exports over and above that of diasporas. Using small\u2010scale regional administrative data, our instrumental variable estimates of export gravity models imply that ceteris paribus, that is, holding constant the total number of immigrants, the expected protrade effect of a migrant becoming an entrepreneur amounts to an average increase of US$5,946 in the export flows toward her country of origin. Besides these dyadic effects, immigrant entrepreneurs unlike nonentrepreneurial immigrants raise a region's overall competitiveness and export flows toward other destinations as well

    The International Trade Network in Space and Time

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    This paper studies how the structure of the International Trade Network (ITN) changes in geographical space and along time. We employ geographical distance between countries in the world to filter the links in the ITN, building a sequence of sub-networks, each one featuring trade links occurring at similar distance. We then test if the topological properties of ITN subnetworks change as distance increases. We find that distance strongly impacts, in non-linear ways, the topology of the ITN. We show that the ITN is disassortative at long distances while it is assortative at short ones. Similarly, the main determinant of the overall high ITN clustering level are triangular trade triples between geographically close countries. This means that trade partnership choices are differentiated over different distance ranges. Such evidence robustly arises over time and after one controls for the economic size and income of trading partners

    Pharmacokinetics and antinociceptive effects of tramadol and its metabolite O-desmethyltramadol following intravenous administration in sheep

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    Although sheep are widely used as an experimental model for various surgical procedures there is a paucity of data on the pharmacokinetics and efficacy of analgesic drugs in this species. The aims of this study were to investigate the pharmacokinetics of intravenously (IV) administered tramadol and its active metabolite O-desmethyltramadol (M1) and to assess the mechanical antinociceptive effects in sheep. In a prospective, randomized, blinded study, six healthy adult sheep were given 4 and 6\u2009mg/kg tramadol and saline IV in a cross-over design with a 2-week wash-out period. At predetermined time points blood samples were collected and physiological parameters and mechanical nociceptive threshold (MNT) values were recorded. The analytical determination of tramadol and M1 was performed using high performance liquid chromatography. Pharmacokinetic parameters fitted a two- and a non-compartmental model for tramadol and M1, respectively. Normally distributed data were analysed by a repeated mixed linear model. Plasma concentration vs. time profiles of tramadol and M1 were similar after the two doses. Tramadol and M1 plasma levels decreased rapidly in the systemic circulation, with both undetectable after 6\u2009h following drug administration. Physiological parameters did not differ between groups; MNT values were not statistically significant between groups at any time point. It was concluded that although tramadol and M1 concentrations in plasma were above the human minimum analgesic concentration after both treatments, no mechanical antinociceptive effects of tramadol were reported. Further studies are warranted to assess the analgesic efficacy of tramadol in sheep

    The Effect of Cromolyn Sodium and Nedocromil Sodium Administered by A pressurized Aerosol with A spacer Device on Exercise-Induced Asthma in Children

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    To compare the effectiveness of cromolyn sodium (CS) (10 mg) and nedocromil sodium (NS) (4 mg) administered by a metered dose inhaler (MDI) with a spacer device in preventing exercise-induced asthma (EIA), eight asthmatic children with EIA were studied in a randomized double-blind, cross-over, placebo-controlled study, CS and NS provided significant, comparable protection from EIA and both were better than placebo. We conclude that CS and NS administered by a pressurized aerosol with a spacer device provide equal protection against EIA in children

    TLR2 plays a role in the activation of human resident renal stem/progenitor cells.

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    Analgesia and/or anaesthesia during piglet castration–part I: efficacy of farm protocols in pain management

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    Pain alleviation associated with surgical castration of piglets is a debated welfare issue. The present study compares the effect of different protocols involving analgesia and/or anaesthesia or sedation suitable under field conditions, with the aim to alleviate pain due to castration in piglets. A randomised within-litter design, with 50 replicates, compared 7 treatments applied 10 min before castration: HAND: positive control, handling only; CTRL: negative control, physiological saline, i.m.; MEL: meloxicam, i.m.; AZA: azaperone, i.m.; PROC: local anaesthesia with procaine and adrenaline, subcutaneously; AZA-MEL: joint administration of azaperone and meloxicam; PROC-MEL: procaine and meloxicam. Efficacy of pain relief was assessed during a 180 min period after castration by serum cortisol and glycaemia, algometry and behaviour. CTRL, AZA, PROC and AZA-MEL piglets showed an increase in cortisol concentration 60 min after castration compared to HAND. Both groups with azaperone (AZA and AZA-MEL) developed concentrations even higher than CTRL (p .05). CRTL and PROC piglets reacted to the algometer at an average lower pressure than HAND (p =.03), differently to the other treatments that showed similar skin sensitivity to HAND (p >.05). No differences in glycaemia and behaviour were observed among treatments. The results suggest that using meloxicam alone might offer a promising option in reducing the expression of pain-related parameters in piglets after surgical castration, however, it appears more efficient when used alone than in association with the anaesthetic agents tested. Procaine administered alone and azaperone seems unsuited to the purpose considered.HIGHLIGHTS Meloxicam used alone is suggested for reducing the expression of pain-related parameters in piglets after surgical castration; When a protocol using procaine is used on the farm during piglets castration, the association with meloxicam reduces some pain-related indicators; Procaine administered alone and azaperone seems unsuited to manage pain after surgical castration of piglets

    The Development of Sustainable Social Farming in Italy: A Case Studies Analysis

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    Social Farming (SF) is a rising practice that offers various typologies of initiatives involving different actors. Peculiarities consist of the types of networks organized at the territorial level and in the innovation processes they implement. In this study, through a cross-case analysis, we take into account six Italian social farms as case studies, interviewing them to understand the activities provided and their organization with the aim of highlighting both the strengths and the criticalities that may limit possible further development of Social Farming in Italy. The results of the analysis pointed out the specificities of the services offered by the social farms and the points of view of the farmers in the sector. Reflecting on these cases in light of the innovation system theory, it was possible to understand both the innovation system in which they developed and the enabling and the limiting aspects for Social Farming initiatives, as well as to codify useful lessons regarding the future organization of sustainable Social Farming services

    A study of the average effect of the 3'APOB-VNTR polymorphism on lipidemic parameters could explain why the short alleles (<35 repeats) are rare in centenarians

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    BACKGROUND: In studies on the genetics of human aging, we observed an age-related variation of the 3'APOB-VNTR genotypic pool (alleles: Short, S, <35 repeats; Medium, M, 35–39 repeats; Long, L, >39 repeats) with the homozygous SS genotype showing a convex frequency trajectory in a healthy aging population. This genotype was rare in centenarians, thus indicating that the S alleles are unfavorable to longevity, while common in adults, thus indicating a protective role at middle age. This apparent paradox could be due to possible effects exerted by the above polymorphism on lipidemic parameters. Aim of the work was to get insights into these puzzling findings METHODS: We followed a double strategy. Firstly, we analyzed the average effects of S (α(S)), M (α(M)), and L (α(L)) alleles on lipidemic parameters in a sample of healthy people (409 subjects aged 20–102 years) recruited in Calabria (southern Italy). The (α(S)), (α(M)), and (α(L)) values were estimated by relating 3'APOB-VNTR genotypes to lipidemic parameters, after adjustment for age, sex and body mass index (multiple regression). Then, we analyzed the S alleles as susceptibility factors of Cardiovascular Atherosclerotic Disease (CD) in CD patients characterized either by low serum HDL-Cholesterol or by high serum LDL-Cholesterol (CD-H and CD-L patients, 40 and 40 subjects respectively). The Odds Ratios (OR) were computed for carriers of S alleles in CD-H and CD-L patients matched for origin, sex and age with controls extracted from the sample of healthy subjects. RESULTS: By the analysis of the healthy sample group we found that the S alleles lower the average values of serum Total Cholesterol (α(S )= -5.98 mg/dL with [-11.62 ÷ -0.74] 95% confidence interval) and LDL-Cholesterol (α(S )= -4.41 mg/dL with [-8.93 ÷ -0.20] 95% confidence interval) while the alleles M and L have no significant effect on the lipidemic phenotype. In line with these findings, the analysis of CD patients showed that the S alleles are protective as for CD-L (O.R. = 0.55 with [0.21 ÷ 0.98] 95% confidence interval) while neutral as for CD-H (O.R. = 0.75 with [0.32 ÷ 1.60] 95% confidence interval). CONCLUSION: On the whole, the S alleles would be advantageous in adults (by protecting from CD-L) while dangerous in the elderly, probably by lowering serum cholesterol below a critical threshold. This could explain the convex frequency trajectory of SS genotypes previously observed in a healthy aging population
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