50 research outputs found

    Molecular organization and mixing in thin solid films of novel perylene tetracarboxylic dianhydride derivatives: Infrared and surface enhanced Raman studies.

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    The present work focuses on the fabrication and spectroscopic characterization of submicron thin solid films of novel organic dyes. The synthesis, thin film fabrication, electronic and vibrational spectra of neat materials are described. The main group of organic dyes studied here are novel perylene tetracarboxylic derivatives. The fabrication of thin solid films on a variety of substrates is demonstrated and the long-range molecular organization in the films, extracted using mainly infrared techniques, is illustrated. The starting point in using vibrations as structural probes, is the vibrational assignments of the characteristic perylene tetracarboxylic fundamentals for each dye under study. The assigned vibrational spectra are employed as references to extract the molecular organization in the vacuum evaporated films using data from the complementary techniques: transmission infrared and reflection-absorption infrared spectroscopy. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2001 .K36. Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4731. Adviser: Ricardo Aroca. Thesis (Ph.D.)--University of Windsor (Canada), 2001

    Measuring Spillovers from Alternative Forms of Foreign Investment

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    Much of the endogenous growth literature has dwelled on evaluating the spillover effects of trade on growth, but much less efforts have been directed towards tracing and quantifying the spillover effects of foreign investments. This paper, in incorporating the effects of various types of foreign investments, namely foreign direct investment (FDI), foreign portfolio investment (FPI) and other foreign investment (OFI) fills this gap in the literature. Adopting the stochastic frontier approach, this paper constructs an OECD frontier based on a panel dataset of 20 OECD countries over the 1981-2000 period. Spillover effects of FDI, FPI, OFI and trade are gauged by their respective contributions towards reducing technical inefficiencies, which are represented by the distance of each country from the constructed frontier. Results from the multiple models examined in the paper indicate that inflows of foreign investment and trade have been instrumental in reducing inefficiencies across OECD countries, whereas outflows of foreign investment exacerbate inefficiencies. The study also confirms some previous findings that the spillover effects of FDI inflows are larger than that of trade but does not find evidence in favour of the view that the spillover effects of trade are overestimated when FDI flows are excluded from the analysis. Moreover, the impact of FDI inflows is larger than those of FPI and OFI inflows. The importance of absorptive capacities of host economies in capturing spillover gains from FDI inflows is also examined. Amongst the various measures of absorptive capacity considered, only human capital was found to be important.

    Measuring Efficiency externalities from Trade and Alternative Forms of Foreign Investment

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    The literature has concentrated on evaluating technological spillovers from trade and inflows of foreign direct investment (FDI). Little effort has been directed towards identifying efficiency externalities arising from international linkages. We evaluate these for a sample of 20 OECD countries between 1982 and 2000 using a stochastic frontier approach. The analysis includes trade, inflows and outflows of FDI, foreign portfolio investment (FPI), and other foreign investment (OFI), and a measure of the absorptive capacities of host economies. We find trade and all foreign investment inflows to lead to increased efficiency. Outflows of FDI are found to exacerbate inefficiency.

    Analysis of Development Performance Using a Development Index Based on Factor Analysis (Old Title- Constructing Multideminsional Indexes of Economic Structure and Development)

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    Development involves changes in social, economic and institutional structures. Quantifying development requires a large array of variables with different characteristics often highly correlated. A factor analysis approach using inferential decisions based on computed standard errors is proposed. The significant factors are used to construct sub-indexes of structural characteristics and a new development index (DI). The properties of DI are analysed and contrasted with more traditional measures, real per capita income (RIPC) and the Human Development Index (HDI). The methodology is applied to data on 45 variables for 97 countries for 1995-2004. DI is found to have stronger discriminating power.

    Stability Diagram of a Few-Electron Triple Dot

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    Quantum dots are considered building blocks for future quantum information circuits. We present here experimental results on a quantum dot circuit consisting of three quantum dots with controlled electron numbers down to one per dot and tunable coupling. We experimentally map out for the first time the stability diagram of the triatomic system and reveal the existence of quadruple points, a signature of the three dots being in resonance. In their vicinity we observe a surprising effect, a 'cloning' of charge transfer transitions related to charge and spin reconfigurations. The experimental results are reproduced by equivalent circuit analysis and Hubbard models

    Measuring Spillovers from Alternative Forms of Foreign Investment

    Get PDF
    Much of the endogenous growth literature has dwelled on evaluating the spillover effects of trade on growth, but much less efforts have been directed towards tracing and quantifying the spillover effects of foreign investments. This paper, in incorporating the effects of various types of foreign investments, namely foreign direct investment (FDI), foreign portfolio investment (FPI) and other foreign investment (OFI) fills this gap in the literature. Adopting the stochastic frontier approach, this paper constructs an OECD frontier based on a panel dataset of 20 OECD countries over the 1981-2000 period. Spillover effects of FDI, FPI, OFI and trade are gauged by their respective contributions towards reducing technical inefficiencies, which are represented by the distance of each country from the constructed frontier. Results from the multiple models examined in the paper indicate that inflows of foreign investment and trade have been instrumental in reducing inefficiencies across OECD countries, whereas outflows of foreign investment exacerbate inefficiencies. The study also confirms some previous findings that the spillover effects of FDI inflows are larger than that of trade but does not find evidence in favour of the view that the spillover effects of trade are overestimated when FDI flows are excluded from the analysis. Moreover, the impact of FDI inflows is larger than those of FPI and OFI inflows. The importance of absorptive capacities of host economies in capturing spillover gains from FDI inflows is also examined. Amongst the various measures of absorptive capacity considered, only human capital was found to be important

    Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

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    Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

    Vinyl sulfone-based ferrocenylation reagents: applications in conjugation and bioconjugation

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    The easy vinyl sulfone derivatization of ferrocene allows the preparation of some effective, versatile and valuable ferrocenylation reagents. The applicability of such compounds in conjugation and bioconjugation of amine and/or thiol containing molecules and biomolecules through Michael-type addition under mild conditions that preserve the biological function of the latter is described. The feasibility of the methodology is demonstrated by the preparation of a variety of conjugates and bioconjugates (ferrocenyl terminated dendrimers and ferrocene–sugar, ferrocene–cyclodextrin, ferrocene–peptide and ferrocene–protein conjugates).Financial support was provided by Ministerio de Ciencia e Innovación (CTQ2011-29299-CO2-01)

    Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

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    Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

    Mapping genomic loci implicates genes and synaptic biology in schizophrenia

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    Schizophrenia has a heritability of 60-80%1, much of which is attributable to common risk alleles. Here, in a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals, we report common variant associations at 287 distinct genomic loci. Associations were concentrated in genes that are expressed in excitatory and inhibitory neurons of the central nervous system, but not in other tissues or cell types. Using fine-mapping and functional genomic data, we identify 120 genes (106 protein-coding) that are likely to underpin associations at some of these loci, including 16 genes with credible causal non-synonymous or untranslated region variation. We also implicate fundamental processes related to neuronal function, including synaptic organization, differentiation and transmission. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in neurodevelopmental disorders. We identify biological processes relevant to schizophrenia pathophysiology; show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders; and provide a resource of prioritized genes and variants to advance mechanistic studies
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