260 research outputs found

    The USMCA & United States-Canada Trade Relations: Ther Perspectives of a U.S. Trade Practitioner

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    After a 13-month-long negotiation process, the United States-Mexico-Canada Agreement was announced on Sept. 20, 2018 to replace the North American Freed Trade Agreement (NAFTA). This article discusses the implications of this transition on Canadian diary management, global excesses in steel and aluminum, softwood lumber, and reform in the World Trade Organization

    Matrix Metalloproteinase-9 Amplifies the Immune Response to \u3ci\u3ePseudomonas aeruginosa\u3c/i\u3e Corneal Infection

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    PURPOSE. The purpose of this study was to determine the role of matrix metalloproteinases (MMP) in Pseudomonas aeruginosa keratitis. METHODS. Gene array and selective real-time PCR examined MMP expression in the cornea of susceptible (C57BL/6, B6) versus resistant (BALB/c) mice before and after infection; zymography tested enzyme activity for MMP-2 and -9. Clinical score, Langerhans cell (LC), and Neutrophil (PMN) quantitation were done in recombinant (r) MMP-9, antibody neutralized, and MMP-9−/− mice. The chemotactic potential of MMP-9 was tested in a Boyden chamber assay; light and transmission microscopy and immunostaining for collagen IV and MMP-9 were used to examine the effects and the source of MMP-9 after infection. ELISA was used to assess IL-1β and MIP-2 levels. RESULTS. Gene array (confirmed by PCR) revealed sixfold more MMP-9, and zymography showed greater enzyme activity in the infected cornea of B6 over BALB/c mice. rMMP-9 injection of BALB/c mice enhanced, whereas MMP-9 antibody neutralization in B6 mice and its absence in MMP-9−/− mice decreased corneal disease. MMP-9−/− and antibody neutralized mice had fewer LCs in cornea; rMMP-9-treated mice had more. A myeloperoxidase (MPO) assay showed a similar pattern for PMN. MMP-9 was not chemotactic for LC or PMN. The basement membrane was more intact in MMP-9−/− over wild-type infected mice and correlated with staining for collagen IV; PMN was a source of MMP-9. IL-1β and MIP-2 were increased in rMMP-9 but decreased in MMP-9 antibody neutralized and MMP-9−/− over control groups. CONCLUSIONS. MMP-9 regulates immune function in cornea by proteolysis, potentiating P. aeruginosa keratitis by degrading collagen IV and upregulating chemotactic cytokines/chemokines IL-1β and MIP-2

    Substance use and nicotine dependence in persistent, remittent, and late-onset ADHD:a 10-year longitudinal study from childhood to young adulthood

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    BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is associated with substance use disorders (SUD; alcohol and/or drug dependence) and nicotine dependence. This study aims to advance our knowledge about the association between SUD, nicotine dependence, and the course of ADHD (persistent versus remittent ADHD and late-onset ADHD).METHODS: ADHD, SUD, and nicotine dependence were longitudinally assessed (mean age at study entry 11.3 years, mean age at follow-up 21.1 years) using structured psychiatric interviews and multi-informant questionnaires in a subsample of the Dutch part of the International Multicenter ADHD Genetics study. Individuals with persistent ADHD (n = 62), remittent ADHD (n = 12), late-onset ADHD (n = 18; age of onset after 12 years), unaffected siblings (n = 50), and healthy controls (n = 47) were assessed. Hazard ratios (HR) with 95% confidence intervals (CIs) were estimated by Cox regression and adjusted for clustered family data, gender, follow-up length, and current age.RESULTS: Individuals with persistent ADHD were at significantly higher risk of development of SUD relative to healthy controls (HR = 4.56, CI 1.17-17.81). In contrast, levels of SUD in those with remittent ADHD were not different from healthy controls (HR = 1.00, CI .07-13.02). ADHD persisters had also higher prevalence rates of nicotine dependence (24.2%) than ADHD remitters (16.7%) and healthy controls (4.3%). A similar pattern was found in initially unaffected siblings who met ADHD criteria at follow-up ("late-onset" ADHD); they had also a higher prevalence of SUD (33%) compared to stable unaffected siblings (20%) and were at significantly increased risk of development of nicotine dependence compared to healthy controls (HR = 13.04, CI 2.08-81.83).CONCLUSIONS: SUD and nicotine dependence are associated with a negative ADHD outcome. Results further emphasize the need for clinicians to comprehensively assess substance use when diagnosing ADHD in adolescents and adults.</p

    Modeling Entropic and Energetic Effects of Linker Length and Rigidity within Synthetic HIV-1 Antibodies designed to Bind Bivalently to Env Spikes

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    Due to the low density of envelope (Env) spikes on the surface of HIV-1, neutralizing IgG antibodies rarely bind bivalently using both antigen-binding arms (Fabs) to crosslink between spikes (inter-spike crosslinking), instead resorting to weaker monovalent binding that is more sensitive to Env mutations. Antibodies capable of bivalently binding within single Env trimers (intra-spike crosslinking) should exhibit increased neutralization potencies. Here we consider synthetic diFabs joined by varying lengths of rigid double-stranded DNA (dsDNA). We asked whether linkers with different rigidities could enhance diFab potency by modeling DNA-Fabs containing different combinations of rigid dsDNA and flexible single-stranded DNA (ssDNA) and created a model that predicts their neutralization potencies. Model predictions showed that although a long flexible polymer may be capable of bivalent binding, it exhibits weak neutralization due to the large loss in entropic degrees of freedom during bivalent binding. In contrast, the strongest neutralization potencies were predicted to require a rigid linker that optimally spanned the distance between two Fab binding sites on an Env trimer. These results inform the design of bivalent anti-HIV-1 therapeutics that utilize avidity effects to remain potent against HIV-1 in the face of the rapid mutation of Env spikes

    Investigation of water vapour sorption mechanism of starch-based pharmaceutical excipients

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    Starch-based excipients are commonly used in oral solid dosage forms. The effect of particle size and pregelatinisation level of starch-based excipients on their water absorption behaviour have been evaluated. The results showed that starch-based excipients have type ii isotherms, indicating that the principal mechanism of sorption is the formation of monolayer coverage and multilayer water molecules (10–80 RH %). It was found that the particle size of starch-based excipients did not have any influence on the rate of water sorption, whereas the level of pregelatinisation changed the kinetics of water sorption-desorption. Results showed that the higher the degree of pregelatinisation, the higher the rate of water absorption, which is irrespective of particle size. SEM images showed that a partially gelatinised starch had a firm granular structure with small pores and channels on the surface while a fully gelatinised starch had more irregular and spongy like surface with a degree of fractured particles

    An ontologically consistent MRI-based atlas of the mouse diencephalon

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    In topological terms, the diencephalon lies between the hypothalamus and the midbrain. It is made up of three segments, prosomere 1 (pretectum), prosomere 2 (thalamus), and prosomere 3 (the prethalamus). A number of MRI-based atlases of different parts of the mouse brain have already been published, but none of them displays the segments the diencephalon and their component nuclei. In this study we present a new volumetric atlas identifying 89 structures in the diencephalon of the male C57BL/6J 12 week mouse. This atlas is based on an average of MR scans of 18 mouse brains imaged with a 16.4T scanner. This atlas is available for download at www.imaging.org.au/AMBMC. Additionally, we have created an FSL package to enable nonlinear registration of novel data sets to the AMBMC model and subsequent automatic segmentation

    The management of bronchus intermedius complications after lung transplantation: A retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Airway complications following lung transplantation remain a significant cause of morbidity and mortality. The management of bronchial complications in Bronchus Intermedius (BI) is challenging due to the location of right upper bronchus. The aim of this study was to analyze the results of BI Montgomery T-tube stent in a consecutive patients with lung transplantations.</p> <p>Methods</p> <p>Between January 2007 and December 2010, 132 lung transplantations were performed at Foch Hospital, Suresnes, France. All the patients who had BI Montgomery T-tube after lung transplantation were included in this retrospective study. The demographic and interventional data and also complications were recorded.</p> <p>Results</p> <p>Out of 132 lung transplant recipients, 12 patients (9 male and 3 female) were entered into this study. The indications for lung transplantation were: cystic fibrosis 8 (67%), emphysema 3 (25%), and idiopathic pulmonary fibrosis 1 (8%). Most of the patients (83%) had bilateral lung transplantation. The mean interval between lung transplantation and interventional bronchoscopy was 11.5 ± 9.8 (SD) months. There was bronchial stenosis at the level of BI in 7 patients (58.3%). The Montgomery T-tube number 10 was used in 9 patients (75%). There was statistically significant difference in Forced Expiratory Volume in one second (FEV1) before and after stent placement (p = 0.01). The most common complication after stent placement was migration (33%).</p> <p>Conclusion</p> <p>BI complications after lung transplantation are still a significant problem. Stenosis or malacia following lung transplantation could be well managed with modified Montgomery T-tube.</p

    A statistical downscaling framework for environmental mapping

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    In recent years, knowledge extraction from data has become increasingly popular, with many numerical forecasting models, mainly falling into two major categories—chemical transport models (CTMs) and conventional statistical methods. However, due to data and model variability, data-driven knowledge extraction from high-dimensional, multifaceted data in such applications require generalisations of global to regional or local conditions. Typically, generalisation is achieved via mapping global conditions to local ecosystems and human habitats which amounts to tracking and monitoring environmental dynamics in various geographical areas and their regional and global implications on human livelihood. Statistical downscaling techniques have been widely used to extract high-resolution information from regional-scale variables produced by CTMs in climate model. Conventional applications of these methods are predominantly dimensional reduction in nature, designed to reduce spatial dimension of gridded model outputs without loss of essential spatial information. Their downside is twofold—complete dependence on unlabelled design matrix and reliance on underlying distributional assumptions. We propose a novel statistical downscaling framework for dealing with data and model variability. Its power derives from training and testing multiple models on multiple samples, narrowing down global environmental phenomena to regional discordance through dimensional reduction and visualisation. Hourly ground-level ozone observations were obtained from various environmental stations maintained by the US Environmental Protection Agency, covering the summer period (June–August 2005). Regional patterns of ozone are related to local observations via repeated runs and performance assessment of multiple versions of empirical orthogonal functions or principal components and principal fitted components via an algorithm with fully adaptable parameters. We demonstrate how the algorithm can be extended to weather-dependent and other applications with inherent data randomness and model variability via its built-in interdisciplinary computational power that connects data sources with end-users
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