200 research outputs found
How early can myocardial iron overload occur in Beta thalassemia major?
BACKGROUND: Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM.
METHODS AND RESULTS: We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload.
CONCLUSIONS: The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old
Shift-Volatility Transmission in East Asian Equity Markets
This paper attempts to provide evidence of "shift-volatility" transmission in the East Asian equity markets. By shift-volatility, we mean the volatility shifts from a low level to a high level, corresponding respectively to tranquil and crisis periods. We examine the interdependence of equity volatilities between Hong-Kong, Indonesia, Japan, Malaysia, the Philippines, Singapore, Thailand and the United States. Our main issue is whether shift-volatility needs to be considered as a regional phenomenon, or from a more global perspective. We find that the timing/spans of high volatility regimes correspond adequately to years historically documented as those of crises (the Asian crisis and the years following the 2008 crisis). Moreover, we suggest different indicators that could be useful to guide the investors in their arbitrage behavior in the different regimes: the duration of each state, the sensitivity of the volatility in a market following a change in the volatility in another market. Finally, we are able to identify which market can be considered as leading markets in terms of volatility
Forecasting with Big Data: A Review
Big Data is a revolutionary phenomenon which is one of the most frequently discussed topics in the modern age, and is expected to remain so in the foreseeable future. In this paper we present a comprehensive review on the use of Big Data for forecasting by identifying and reviewing the problems, potential, challenges and most importantly the related applications. Skills, hardware and software, algorithm architecture, statistical significance, the signal to noise ratio and the nature of Big Data itself are identified as the major challenges which are hindering the process of obtaining meaningful forecasts from Big Data. The review finds that at present, the fields of Economics, Energy and Population Dynamics have been the major exploiters of Big Data forecasting whilst Factor models, Bayesian models and Neural Networks are the most common tools adopted for forecasting with Big Data
Stock markets and effective exchange rates in European countries: threshold cointegration findings
© 2015, Eurasia Business and Economics Society. The nexus between stock markets and exchange rates is examined in the case of eight European countries. The sample consists of four economies with national currencies and four that have adopted the euro. Thus, if differences between the two groups in the relationship governing the two markets exist, they will be unveiled. To this effect, a threshold cointegration methodology is adopted that allows for more reliable inferences to be drawn for both the short and long run nexus between the two markets. Monthly data is used covering the period 01/2000–12/2014. The findings reported herein offer support in favor of the portfolio approach thesis over the recent economic crisis period, but this finding is not the case for the entire sample. Bidirectional causality is found for Norway and the UK, pointing to a currency effect on stock markets. In view of the findings reported herein, policies aiming at reducing uncertainty in the stock markets can exert beneficial effects on currency markets
Socioeconomic Predictors of Cognition in Ugandan Children: Implications for Community Interventions
Background: Several interventions to improve cognition in at risk children have been suggested. Identification of key variables predicting cognition is necessary to guide these interventions. This study was conducted to identify these variables in Ugandan children and guide such interventions. Methods: A cohort of 89 healthy children (45 females) aged 5 to 12 years old were followed over 24 months and had cognitive tests measuring visual spatial processing, memory, attention and spatial learning administered at baseline, 6 months and 24 months. Nutritional status, child’s educational level, maternal education, socioeconomic status and quality of the home environment were also measured at baseline. A multivariate, longitudinal model was then used to identify predictors of cognition over the 24 months. Results: A higher child’s education level was associated with better memory (p = 0.03), attention (p = 0.005) and spatial learning scores over the 24 months (p = 0.05); higher nutrition scores predicted better visual spatial processing (p = 0.002) and spatial learning scores (p = 0.008); and a higher home environment score predicted a better memory score (p = 0.03). Conclusion: Cognition in Ugandan children is predicted by child’s education, nutritional status and the home environment
Limited genetic variation and structure in softshell clams (Mya arenaria) across their native and introduced range
Author Posting. © Springer, 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Conservation Genetics 10 (2009): 803-814, doi:10.1007/s10592-008-9641-y.To offset declines in commercial landings of the softshell clam, Mya arenaria, resource
managers are engaged in extensive stocking of seed clams throughout its range in the
northwest Atlantic. Because a mixture of native and introduced stocks can disrupt locally
adapted genotypes, we investigated genetic structure in M. arenaria populations across
its current distribution to test for patterns of regional differentiation. We sequenced
mitochondrial cytochrome oxidase I (COI) for a total of 212 individuals from 12 sites in
the northwest Atlantic (NW Atlantic), as well as two introduced sites, the northeast
Pacific (NE Pacific) and the North Sea and Europe (NS Europe). Populations exhibited
extremely low genetic variation, with one haplotype dominating (65-100%) at all sites
sampled. Despite being introduced in the last 150-400 years, both NE Pacific and NS
Europe populations had higher diversity measures than those in the NW Atlantic and both
contained private haplotypes at frequencies of 10% to 27% consistent with their
geographic isolation. While significant genetic structure (FST = 0.159, p<0.001) was
observed between NW Atlantic and NS Europe, there was no evidence for genetic
structure across the pronounced environmental clines of the NW Atlantic. Reduced
genetic diversity in mtDNA combined with previous studies reporting reduced genetic
diversity in nuclear markers strongly suggests a recent population expansion in the NW
Atlantic, a pattern that may result from the retreat of ice sheets during Pleistocene glacial
periods. Lack of genetic diversity and regional genetic differentiation suggests that
present management strategies for the commercially important softshell clam are unlikely
to have a significant impact on the regional distribution of genetic variation, although the
possibility of disrupting locally adapted stocks cannot be excluded.This work was supported by NSF grants OCE-0326734 and OCE-0215905 to L.
Mullineaux and OCE- 0349177 (Biological Oceanography) to PHB
The Myosin Va Head Domain Binds to the Neurofilament-L Rod and Modulates Endoplasmic Reticulum (ER) Content and Distribution within Axons
The neurofilament light subunit (NF-L) binds to myosin Va (Myo Va) in neurons but the sites of interaction and functional significance are not clear. We show by deletion analysis that motor domain of Myo Va binds to the NF-L rod domain that forms the NF backbone. Loss of NF-L and Myo Va binding from axons significantly reduces the axonal content of ER, and redistributes ER to the periphery of axon. Our data are consistent with a novel function for NFs as a scaffold in axons for maintaining the content and proper distribution of vesicular organelles, mediated in part by Myo Va. Based on observations that the Myo Va motor domain binds to intermediate filament (IF) proteins of several classes, Myo Va interactions with IFs may serve similar roles in organizing organelle topography in different cell types
A Genome-wide Linkage Analysis and Mutation Analysis of Hereditary Congenital Blepharoptosis in a Japanese Family
Hereditary congenital ptosis (PTOS) is defined as drooping of the upper eyelid without any other accompanying symptoms and distinguished from syndromic blepharoptosis.Two previous linkage analyses assigned a PTOS locus (PTOS1) to 1p32-p34.1 and another (PTOS2) to Xq24-q27.1. In addition, in a sporadic case with a balanced chromosomal translocation t(1;8)(p34.3;q21.12), the ZFHX4 (zinc finger homeodomain 4) gene was found to be disrupted at the 8q21.12 breakpoint, but there was no gene at the 1p34.3 breakpoint, suggesting the existence of the third PTOS locus (PTOS1) at 8q21.12. We carried out a genome-wide linkage analysis in a Japanese PTOS family and calculated two-point and multipoint LOD scores with reduced penetrance. Haplotype analysis gave three candidate disease-responsible regions, i.e., 8q21.11-q22.1, 12q24.32-q24.33 and 14q21.1-q23.2. Although the family size is too small to define one of them, 8q21.11-q22.1 is a likely candidate region, because it contains the previously reported translocation breakpoint above. We thus performed mutation, Southern-blot and methylation analyses of ZFHX4, but could not find any disease specific change in the family. Nevertheless, our data may support the localization of PTOS1.長崎大学学位論文 学位記番号:博(医歯薬)甲第153号 博士(医学)学位授与年月日:平成20年3月19
Four Regional Marine Biodiversity Studies: Approaches and Contributions to Ecosystem-Based Management
We compare objectives and approaches of four regional studies of marine biodiversity: Gulf of Maine Area Census of Marine Life, Baltic Sea History of Marine Animal Populations, Great Barrier Reef Seabed Biodiversity Project, and Gulf of Mexico Biodiversity Project. Each program was designed as an "ecosystem" scale but was created independently and executed differently. Each lasted 8 to 10 years, including several years to refine program objectives, raise funding, and develop research networks. All resulted in improved baseline data and in new, or revised, data systems. Each contributed to the creation or evolution of interdisciplinary teams, and to regional, national, or international science-management linkages. To date, there have been differing extents of delivery and use of scientific information to and by management, with greatest integration by the program designed around specific management questions. We evaluate each research program's relative emphasis on three principal elements of biodiversity organization: composition, structure, and function. This approach is used to analyze existing ecosystem-wide biodiversity knowledge and to assess what is known and where gaps exist. In all four of these systems and studies, there is a relative paucity of investigation on functional elements of biodiversity, when compared with compositional and structural elements. This is symptomatic of the current state of the science. Substantial investment in understanding one or more biodiversity element(s) will allow issues to be addressed in a timely and more integrative fashion. Evaluating research needs and possible approaches across specific elements of biodiversity organization can facilitate planning of future studies and lead to more effective communication between scientists, managers, and stakeholders. Building a general approach that captures how various studies have focused on different biodiversity elements can also contribute to meta-analyses of worldwide experience in scientific research to support ecosystem-based management
- …