155 research outputs found

    If the Unites States sneezes, does the world need paracetamol?

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    There is an old saying that states that “If the United States sneezes, the rest of the world catches a cold”. Against this background, it is argued that some countries, especifically China, can “decouple” from the US economy and sustain strong growth in the face of a US slowdown. In this paper we analyze the extent to which the US economy affects international business fluctuations across countries. A multivariate nonlinear LSTAR model is estimated for the GDP cyclical component of China, France, Germany, the UK and the USA. This nonlinear framework allows the business cycles asymmetries to be captured properly in order to identify the synchronization behavior across countries. Our results suggest that there is a relevant influence from the US cycle, since it acts as a source of international business cycle synchronization. However, spillovers from US cycle fluctuations to China are rather modest.Business Cycle, nonlinearities, synchronization, decoupling

    New Evidence on the Role of Regional Clusters and Convergence in China (1952-2008)

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    A new panel method is applied to the case of Chinese provinces to analyze the existence of club convergence in terms of per capita income, labor productivity, capital intensity, and total factor productivity from 1952 to 2008. The advantage of this approach is that it takes into account the heterogeneity of Chinese regions in a nonlinear time-varying framework, where more attention is paid to the spatial dimension. This time-varying approach outperforms other methods used in the relevant literature for an economy in transition, such as China, that has undergone a significant transformation over the period under consideration. Our results indicate that Chinese regions have converged into clubs. However, it is observed that Heilongjiang is diverging in terms of labor productivity and capital intensity, while Liaoning and Guizhou display similar patterns in terms of labor productivity, and Shanxi and Hebei in terms of capital intensity. These results indicate that specific economic packages need to be implemented in the clusters that were identified, with special attention to those regions that show a divergence behavior, in order to guarantee the sustainability and equality of regional growth.Endogenous Unit Root Test, Club Convergence, Chinese regions

    The world trade network and the environment

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    This papers analyses the role of the world trade network on the environment. We rely on methods developed for social network analysis to identify the most important countries in connecting trade between all the other countries in the world trade network. We then estimate how the network or indirect effects from trade affect the environmental quality of a country. As the trade networks are endogenously determined by trade and environmental conditions, we use as instrumental variables the growth in the population of trade partners and the growth in the population of trade partners' partners to exploit exogenous variation in the world trade network. Once we simultaneously estimate the environmental, trade, income and network equations using a three-stage least square procedure, we find that network effects harm the environmental quality of developed countries but improve the environment of developing countries

    Synthesis of hydroxyfatty esters by sequential epoxidation-hydrogenolysis: Solvent effects

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    The tandem/sequential combination of epoxidation and hydrogenolysis for unsaturated fatty esters is not straightforward, due to incompatibility problems with the impurities present or generated in the used solvents. The chlorinated impurities in alpha, alpha, alpha-trifluorotoluene leads to the formation of important amounts of chlorohydrins by HCl formation in the hydrogenolysis step. The use of trifluoroethanol (TFE) in the epoxidation step produces trifluoroacetic acid traces by oxidation, responsible for the opening of the epoxide with water and TFE. The solvent of choice was finally isobutyl acetate, which gathers the required physicochemical properties, with 85 % yield of hydroxystearates from methyl oleate in a sequential process

    School Leadership Interventions Under the Every Student Succeeds Act: Evidence Review - Updated and Expanded

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    This RAND analysis offers guidance to states and districts on how they can choose to use the Every Student Succeeds Act to help achieve their school improvement goals by supporting principals and other school leaders

    Non-CO2 generating energy shares in the world : cross-country differences and polarization.

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    The aim of this paper is to examine the spatial distribution of non-CO2 generating energy sources in the world for the period 1990–2009, paying special attention to the evolution of cross-country disparities. To this end, after carrying out a classical convergence analysis, a more thorough investigation of the entire distribution is presented by examining its external shape, the intra-distribution dynamics and the long-run equilibrium distribution. This analysis reveals the existence of a weak, rather insignificant, convergence process and that large crosscountry differences are likely to persist in the long-run. Next, as polarization indicators are a proper way of appraising potential conflict in international environmental negotiations, we test whether, or not, the distribution dynamics concurs with the presence of polarization. Our results indicate that two poles can be clearly differentiated, one with high and other with low non-CO2 generating energy shares. In view of these findings, and to ensure a fair transition to a sustainable energy system, the paper calls for the development of an ambitious clean energy agenda, especially in countries with low non-CO2 generating energy shares

    An intranasal selective antisense oligonucleotide impairs lung cyclooxygenase-2 production and improves inflammation, but worsens airway function, in house dust mite sensitive mice

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    <p>Abstract</p> <p>Background</p> <p>Despite its reported pro-inflammatory activity, cyclooxygenase (COX)-2 has been proposed to play a protective role in asthma. Accordingly, COX-2 might be down-regulated in the airway cells of asthmatics. This, together with results of experiments to assess the impact of COX-2 blockade in ovalbumin (OVA)-sensitized mice in vivo, led us to propose a novel experimental approach using house dust mite (HDM)-sensitized mice in which we mimicked altered regulation of COX-2.</p> <p>Methods</p> <p>Allergic inflammation was induced in BALBc mice by intranasal exposure to HDM for 10 consecutive days. This model reproduces spontaneous exposure to aeroallergens by asthmatic patients. In order to impair, but not fully block, COX-2 production in the airways, some of the animals received an intranasal antisense oligonucleotide. Lung COX-2 expression and activity were measured along with bronchovascular inflammation, airway reactivity, and prostaglandin production.</p> <p>Results</p> <p>We observed impaired COX-2 mRNA and protein expression in the lung tissue of selective oligonucleotide-treated sensitized mice. This was accompanied by diminished production of mPGE synthase and PGE<sub>2 </sub>in the airways. In sensitized mice, the oligonucleotide induced increased airway hyperreactivity (AHR) to methacholine, but a substantially reduced bronchovascular inflammation. Finally, mRNA levels of hPGD synthase remained unchanged.</p> <p>Conclusion</p> <p>Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients. This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened. This approach will provide insights into the differential regulation of inflammation and lung function in asthma, and will help identify pharmacological targets within the COX-2/PG system.</p

    Prostaglandin E2 Prevents Hyperosmolar-Induced Human Mast Cell Activation through Prostanoid Receptors EP2 and EP4

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    Background: Mast cells play a critical role in allergic and inflammatory diseases, including exercise-induced bronchoconstriction (EIB) in asthma. The mechanism underlying EIB is probably related to increased airway fluid osmolarity that activates mast cells to the release inflammatory mediators. These mediators then act on bronchial smooth muscle to cause bronchoconstriction. In parallel, protective substances such as prostaglandin E2 (PGE2) are probably also released and could explain the refractory period observed in patients with EIB. Objective: This study aimed to evaluate the protective effect of PGE2 on osmotically activated mast cells, as a model of exercise-induced bronchoconstriction. Methods: We used LAD2, HMC-1, CD34-positive, and human lung mast cell lines. Cells underwent a mannitol challenge, and the effects of PGE2 and prostanoid receptor (EP) antagonists for EP1-4 were assayed on the activated mast cells. Beta-hexosaminidase release, protein phosphorylation, and calcium mobilization were assessed. Results: Mannitol both induced mast cell degranulation and activated phosphatidyl inositide 3-kinase and mitogen-activated protein kinase (MAPK) pathways, thereby causing de novo eicosanoid and cytokine synthesis. The addition of PGE2 significantly reduced mannitol-induced degranulation through EP2 and EP4 receptors, as measured by beta-hexosaminidase release, and consequently calcium influx. Extracellular-signal-regulated kinase 1/2, c-Jun N-terminal kinase, and p38 phosphorylation were diminished when compared with mannitol activation alone. Conclusions:Our data show a protective role for the PGE2 receptors EP2 and EP4 following osmotic changes, through the reduction of human mast cell activity caused by calcium influx impairment and MAP kinase inhibition

    The effects of patient characteristics on ADHD diagnosis and treatment: a factorial study of family physicians

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    <p>Abstract</p> <p>Background</p> <p>Attention Deficit Hyperactivity Disorder (ADHD) is a costly and prevalent disorder in the U.S., especially among youth. However, significant disparities in diagnosis and treatment appear to be predicted by the race and insurance status of patients.</p> <p>Methods</p> <p>This study employed a web-based factorial survey with four ADHD cases derived from an ADHD clinic, two diagnosed with ADHD in actual evaluation, and two not. Randomized measures included race and insurance status of the patients. Participants N = (187) included clinician members of regional and national practice-based research networks and the U.S. clinical membership of the Society of Teachers of Family Medicine. The main outcomes were decisions to 1) diagnose and 2) treat the cases, based upon the information presented, analyzed via binary logistic regression of the randomized factors and case indicators on diagnosis and treatment.</p> <p>Results</p> <p>ADHD-positive cases were 8 times more likely to be diagnosed and 12 times more likely to be treated, and the male ADHD positive case was more likely to be diagnosed and treated than the female ADHD positive case. Uninsured cases were significantly more likely to be treated overall, but male cases that were uninsured were about half as likely to be diagnosed and treated with ADHD. Additionally, African-American race appears to increase the likelihood of medicinal treatment for ADHD and being both African-American and uninsured appears to cut the odds of medicinal treatment in half, but not significantly.</p> <p>Conclusions</p> <p>Family physicians were competent at discerning between near-threshold ADHD-negative and ADHD positive cases. However, insurance status and race, as well as gender, appear to affect the likelihood of diagnosis and treatment for ADHD in Family Medicine settings.</p

    Parrots Eat Nutritious Foods despite Toxins

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    Generalist herbivores are challenged not only by the low nitrogen and high indigestibility of their plant foods, but also by physical and chemical defenses of plants. This study investigated the foods of wild parrots in the Peruvian Amazon and asked whether these foods contain dietary components that are limiting for generalist herbivores (protein, lipids, minerals) and in what quantity; whether parrots chose foods based on nutrient content; and whether parrots avoid plants that are chemically defended.We made 224 field observations of free-ranging parrots of 17 species in 8 genera foraging on 102 species of trees in an undisturbed tropical rainforest, in two dry seasons (July-August 1992-1993) and one wet season (January-February1994). We performed laboratory analyses of parts of plants eaten and not eaten by parrots and brine shrimp assays of toxicity as a proxy for vertebrates. Parrots ate seeds, fruits, flowers, leaves, bark, and insect larvae, but up to 70% of their diet comprised seeds of many species of tropical trees, in various stages of ripeness. Plant parts eaten by parrots were rich in protein, lipid, and essential minerals, as well as potentially toxic chemicals. Seeds were higher than other plant materials in protein and lipid and lower in fiber. Large macaws of three species ate foods higher in protein and lipids and lower in fiber compared to plant parts available but not eaten. Macaws ate foods that were lower in phenolic compounds than foods they avoided. Nevertheless, foods eaten by macaws contained measurable levels of toxicity. Macaws did not appear to make dietary selections based on mineral content.Parrots represent a remarkable example of a generalist herbivore that consumes seeds destructively despite plant chemical defenses. With the ability to eat toxic foods, rainforest-dwelling parrots exploited a diversity of nutritious foods, even in the dry season when food was scarce for other frugivores and granivores
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