601 research outputs found

    Air connectivity and foreign direct investments: economic effects of the introduction of new routes

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    Purpose The key research question for this study was whether the spatial network structure offered by the global airline system contributes to the development of Italian inward Foreign Direct Investments (FDIs). We argue that the introduction of a new route, by reducing firm's transport costs and facilitating tacit and complex knowledge flow, should increase the likelihood of FDI exchange between newly connected regions. Methods We employed a comparison group design considering both small and medium enterprises and large companies at the municipality level. Results The results showed that FDIs increased overall by 33.7% in the two years after opening of the new routes while FDIs in the control group decreased by 16.6%. Similar results were obtained using different measures of FDI (i.e. the number of generated employees) and by weighting the routes by their frequencies. Conclusions Given the substantial benefits that urban areas can obtain from attracting multinational firms, our results provide new evidence of the contribution of transport infrastructures to local development. From a policymaker perspective, regional policies aimed at attracting FDIs must contextually promote the development of transport infrastructure and in particular international airports. Investments to improve air transport capacity, strategies to attract both traditional and low-cost airlines, providing legal authorization or financing ground transport are all critical aspects for the success of such policies

    A BAC-Based Integrated Linkage Map of the Silkworm \u3cem\u3eBombyx mori\u3c/em\u3e

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    Background: In 2004, draft sequences of the model lepidopteran Bombyx mori were reported using whole-genome shotgun sequencing. Because of relatively shallow genome coverage, the silkworm genome remains fragmented, hampering annotation and comparative genome studies. For a more complete genome analysis, we developed extended scaffolds combining physical maps with improved genetic maps. Results: We mapped 1,755 single nucleotide polymorphism (SNP) markers from bacterial artificial chromosome (BAC) end sequences onto 28 linkage groups using a recombining male backcross population, yielding an average inter-SNP distance of 0.81 cM (about 270 kilobases). We constructed 6,221 contigs by fingerprinting clones from three BAC libraries digested with different restriction enzymes, and assigned a total of 724 single copy genes to them by BLAST (basic local alignment search tool) search of the BAC end sequences and high-density BAC filter hybridization using expressed sequence tags as probes. We assigned 964 additional expressed sequence tags to linkage groups by restriction fragment length polymorphism analysis of a nonrecombining female backcross population. Altogether, 361.1 megabases of BAC contigs and singletons were integrated with a map containing 1,688 independent genes. A test of synteny using Oxford grid analysis with more than 500 silkworm genes revealed six versus 20 silkworm linkage groups containing eight or more orthologs of Apis versus Tribolium, respectively. Conclusion: The integrated map contains approximately 10% of predicted silkworm genes and has an estimated 76% genome coverage by BACs. This provides a new resource for improved assembly of whole-genome shotgun data, gene annotation and positional cloning, and will serve as a platform for comparative genomics and gene discovery in Lepidoptera and other insects

    Identification of the initial molecular changes in response to circulating angiogenic cells-mediated therapy in critical limb ischemia

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    BackgroundCritical limb ischemia (CLI) constitutes the most aggressive form of peripheral arterial occlusive disease, characterized by the blockade of arteries supplying blood to the lower extremities, significantly diminishing oxygen and nutrient supply. CLI patients usually undergo amputation of fingers, feet, or extremities, with a high risk of mortality due to associated comorbidities.Circulating angiogenic cells (CACs), also known as early endothelial progenitor cells, constitute promising candidates for cell therapy in CLI due to their assigned vascular regenerative properties. Preclinical and clinical assays with CACs have shown promising results. A better understanding of how these cells participate in vascular regeneration would significantly help to potentiate their role in revascularization.Herein, we analyzed the initial molecular mechanisms triggered by human CACs after being administered to a murine model of CLI, in order to understand how these cells promote angiogenesis within the ischemic tissues.MethodsBalb-c nude mice (n:24) were distributed in four different groups: healthy controls (C, n:4), shams (SH, n:4), and ischemic mice (after femoral ligation) that received either 50 mu l physiological serum (SC, n:8) or 5x10(5) human CACs (SE, n:8). Ischemic mice were sacrificed on days 2 and 4 (n:4/group/day), and immunohistochemistry assays and qPCR amplification of Alu-human-specific sequences were carried out for cell detection and vascular density measurements. Additionally, a label-free MS-based quantitative approach was performed to identify protein changes related.ResultsAdministration of CACs induced in the ischemic tissues an increase in the number of blood vessels as well as the diameter size compared to ischemic, non-treated mice, although the number of CACs decreased within time. The initial protein changes taking place in response to ischemia and more importantly, right after administration of CACs to CLI mice, are shown.ConclusionsOur results indicate that CACs migrate to the injured area; moreover, they trigger protein changes correlated with cell migration, cell death, angiogenesis, and arteriogenesis in the host. These changes indicate that CACs promote from the beginning an increase in the number of vessels as well as the development of an appropriate vascular network.Institute of Health Carlos III, ISCIII; Junta de Andaluci

    Long-lived neutral-kaon flux measurement for the KOTO experiment

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    The KOTO (K0K^0 at Tokai) experiment aims to observe the CP-violating rare decay KLπ0ννˉK_L \rightarrow \pi^0 \nu \bar{\nu} by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research Complex. The KLK_L flux is an essential parameter for the measurement of the branching fraction. Three KLK_L neutral decay modes, KL3π0K_L \rightarrow 3\pi^0, KL2π0K_L \rightarrow 2\pi^0, and KL2γK_L \rightarrow 2\gamma were used to measure the KLK_L flux in the beam line in the 2013 KOTO engineering run. A Monte Carlo simulation was used to estimate the detector acceptance for these decays. Agreement was found between the simulation model and the experimental data, and the remaining systematic uncertainty was estimated at the 1.4\% level. The KLK_L flux was measured as (4.183±0.017stat.±0.059sys.)×107(4.183 \pm 0.017_{\mathrm{stat.}} \pm 0.059_{\mathrm{sys.}}) \times 10^7 KLK_L per 2×10142\times 10^{14} protons on a 66-mm-long Au target.Comment: 27 pages, 16 figures. To be appeared in Progress of Theoretical and Experimental Physic

    Repression of tyrosine hydroxylase is responsible for the sex-linked chocolate mutation of the silkworm, \u3cem\u3eBombyx mori\u3c/em\u3e

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    Pigmentation patterning has long interested biologists, integrating topics in ecology, development, genetics, and physiology. Wild-type neonatal larvae of the silkworm, Bombyx mori, are completely black. By contrast, the epidermis and head of larvae of the homozygous recessive sex-linked chocolate (sch) mutant are reddish brown. When incubated at 30 °C, mutants with the sch allele fail to hatch; moreover, homozygous mutants carrying the allele sch lethal (schl) do not hatch even at room temperature (25 °C). By positional cloning, we narrowed a region containing sch to 239,622 bp on chromosome 1 using 4,501 backcross (BC1) individuals. Based on expression analyses, the best sch candidate gene was shown to be tyrosine hydroxylase (BmTh). BmTh coding sequences were identical among sch, schl, and wild-type. However, in sch the ∼70-kb sequence was replaced with ∼4.6 kb of a Tc1-mariner type transposon located ∼6 kb upstream of BmTh, and in schl, a large fragment of an L1Bm retrotransposon was inserted just in front of the transcription start site of BmTh. In both cases, we observed a drastic reduction of BmTh expression. Use of RNAi with BmTh prevented pigmentation and hatching, and feeding of a tyrosine hydroxylase inhibitor also suppressed larval pigmentation in the wild-type strain, pnd+ and in a pS (black-striped) heterozygote. Feeding L-dopa to sch neonate larvae rescued the mutant phenotype from chocolate to black. Our results indicate the BmTh gene is responsible for the sch mutation, which plays an important role in melanin synthesis producing neonatal larval color

    Isolation and Molecular Characterization of Streptococcal Species recovered from Clinical Infections in Farmed Nile Tilapia (Oreochromis niloticus) in the Philippines

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    Streptococcosis cause severe losses for global tilapia farming especially in developing countries. The aim of this study was to identify and characterize streptococci recovered from Nile tilapia farmed in the Philippines. Moribund and apparently healthy fish were sampled from grow-out cages, ponds and hatcheries. Clinical signs observed included exophthalmia, eye opacity, ascites, lethargy, erratic swimming, and haemorrhages. Results showed that both Streptococcus iniae and Streptococcus agalactiae were associated with disease in these sites. Consistent with global reports, including those from Southeast Asia, S. agalactiae was more widespread than S. iniae. Molecular serotyping of the S. agalactiae isolates identified the serotype Ia and serotype Ib. Histopathological findings were meningitis, meningoencephalitis and septicaemia. Identical virulence profiles were found for all strains of S. iniae, while S. agalactiae strains were separated into virulence profile I and profile II. All strains were susceptible to the tested antibiotics and resistant to oxolinic acid. Only S. agalactiae serotype Ib showed resistance to sulphamethoxazole-trimethoprim. This is the first study from the Philippines to characterize the streptococci involved in disease outbreaks in tilapia aquaculture. Outputs from this study will promote development of efficacious disease control strategies in tilapia farming for the Philippines and in Southeast Asia

    Sleep Disorders and Demand for Medical Services: Evidence from a Population-Based Longitudinal Study

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    Background: The aim of this study was to investigate whether insomnia and obstructive sleep apnea (OSA) were predictors of hospitalizations or emergency department visits during two years following the Sao Paulo Epidemiologic Sleep Study (EPISONO) sample. Methods and Findings: All participants (n = 1,101) who underwent a baseline evaluation between July and December 2007 were contacted in December 2009 and asked to fill out a questionnaire about body weight changes, number of hospitalizations and visits to the emergency department. Participants lost during the follow-up period represented 3.2 % (n = 35) and 7 subjects had died. Hospitalizations were reported by 116 volunteers (10.5%) and emergency department visits were reported by 136 participants (12.4%). The average body mass index (BMI) did not vary significantly between the first and the second assessment [26.7(95%CI:26.3–27.1) vs. 26.9(26.5–27.4) kg/m2]. After adjusting for confounders, a multiple logistic regression model revealed that female gender [1.4(1.0–1.9)], age 40years,insomniadiagnosedaccordingtotheDSMIVcriteria[1.6(1.02.6)],andapneahypopneaindex40 years, insomnia diagnosed according to the DSM-IV criteria [1.6(1.0–2.6)], and apneahypopnea index 15 [1.5(1.0–2.2)] were predictors of hospitalizations and/or demand for emergency services. Conclusion: Our study of a probabilistic sample of the Sao Paulo inhabitants shows that over a period of two years, insomnia and OSA were both associated with health impairment. Considering the high prevalence and public health burden of slee
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