212 research outputs found
Type F congenital quadricuspid aortic valve: A very rare case diagnosed by 3-dimenional transoesophageal echocardiography
Congenital quadricuspid aortic valve (QAV) is a rare cardiac anomaly. Several different anatomical variations of a quadricuspid aortic valve have been described. Aortic regurgitation is the predominant valvular dysfunction associated with QAV and patients tend to present in their 5(th) or 6(th) decade of life. This anomaly is rarely picked up by transthoracic echocardiogram (TTE). A comprehensive transoesophageal echocardiography (TOE) study is more likely to diagnose it. We describe a very rare type of QAV - Type F in a 52-year-old lady who presented with symptoms of shortness of breath and pre-syncope. We include TOE images and intra-operative valve images
Cooperation for public goods under uncertainty
Everyone wants clean air, peace and other public goods but is tempted to
freeride on others' efforts. The usual way out of this dilemma is to impose
norms, maintain reputations and incentivize individuals to contribute. In
situations of high uncertainty, however, such as confrontations of protesters
with a dictatorial regime, the usual measures are not feasible, but cooperation
can be achieved nevertheless. We use an Ising model with asymmetric spins that
represent cooperation and defection to show numerically how public goods can be
realized. Under uncertainty, people use the heuristic of conformity. The
turmoil of a confrontation causes some individuals to cooperate accidentally,
and at a critical level of turmoil, they entail a cascade of cooperation. This
critical level is much lower in small networks
Different measures of smoking exposure and mammographic density in postmenopausal Norwegian women: a cross-sectional study
Background: Recent cohort studies have suggested an
increased risk of breast cancer with long duration of smoking,
and with smoking initiation before first birth. Cigarette smoking
may have both carcinogenic effects and antiestrogenic effects
on the breast tissue. We decided to examine the relationship
between different measures of smoking exposure and
mammographic density.
Methods: Lifetime smoking history was collected through
interview and questionnaires among 907 postmenopausal
participants in the Tromsø Mammography and Breast Cancer
study. The mammograms were obtained from the governmental
Norwegian Breast Cancer Screening Program. Mammograms
were classified according to the percentage and absolute
mammographic densities using a previously validated computerassisted
method.
Results:Sixty-five percent of the women reported having ever
smoked cigarettes, while 34% were current smokers. After
adjustment for age, age at first birth, parity, age at menopause,
postmenopausal hormone therapy use, and body mass index,
smoking was inversely associated with both measures of
mammographic density (both trends P < 0.01). Both current
smokers and former smokers had significantly lower adjusted
mean percentage mammographic density compared with never
smokers (P = 0.003 and P = 0.006, respectively). An inverse
dose–response relationship with mammographic density was
found between both the number of cigarettes and the number of
pack-years smoked among current smokers. Current smokers
who smoked 11 cigarettes or more daily had a 3.7% absolute
(36% relative difference) lower percentage mammographic
density compared with current smokers who smoked seven
cigarettes or less daily (P = 0.008). When former smokers were
stratified according to time since smoking cessation, we found
that women who had stopped smoking less than 24 years ago
had a significantly lower mean percentage mammographic
density compared with never smokers (P < 0.001).
Conclusion: We found modest inverse dose–response
associations between numbers of cigarettes and of pack-years
smoked and both measures of mammographic density among
current smokers. Former smokers who had stopped smoking
less than 24 years ago also had a statistically significantly lower
mean percentage mammographic density when compared with
never smokers. These findings are consistent with an
antiestrogenic effect of cigarette smoking on the breast tissue
The pseudogap: friend or foe of high Tc?
Although nineteen years have passed since the discovery of high temperature
superconductivity, there is still no consensus on its physical origin. This is
in large part because of a lack of understanding of the state of matter out of
which the superconductivity arises. In optimally and underdoped materials, this
state exhibits a pseudogap at temperatures large compared to the
superconducting transition temperature. Although discovered only three years
after the pioneering work of Bednorz and Muller, the physical origin of this
pseudogap behavior and whether it constitutes a distinct phase of matter is
still shrouded in mystery. In the summer of 2004, a band of physicists gathered
for five weeks at the Aspen Center for Physics to discuss the pseudogap. In
this perspective, we would like to summarize some of the results presented
there and discuss its importance in the context of strongly correlated electron
systems.Comment: expanded version, 20 pages, 11 figures, to be published, Advances in
Physic
Study of Women, Infant feeding, and Type 2 diabetes mellitus after GDM pregnancy (SWIFT), a prospective cohort study: methodology and design
<p>Abstract</p> <p>Background</p> <p>Women with history of gestational diabetes mellitus (GDM) are at higher risk of developing type 2 diabetes within 5 years after delivery. Evidence that lactation duration influences incident type 2 diabetes after GDM pregnancy is based on one retrospective study reporting a null association. The Study of Women, Infant Feeding and Type 2 Diabetes after GDM pregnancy (SWIFT) is a prospective cohort study of postpartum women with recent GDM within the Kaiser Permanente Northern California (KPNC) integrated health care system. The primary goal of SWIFT is to assess whether prolonged, intensive lactation as compared to formula feeding reduces the 2-year incidence of type 2 diabetes mellitus among women with GDM. The study also examines whether lactation intensity and duration have persistent favorable effects on blood glucose, insulin resistance, and adiposity during the 2-year postpartum period. This report describes the design and methods implemented for this study to obtain the clinical, biochemical, anthropometric, and behavioral measurements during the recruitment and follow-up phases.</p> <p>Methods</p> <p>SWIFT is a prospective, observational cohort study enrolling and following over 1, 000 postpartum women diagnosed with GDM during pregnancy within KPNC. The study enrolled women at 6-9 weeks postpartum (baseline) who had been diagnosed by standard GDM criteria, aged 20-45 years, delivered a singleton, term (greater than or equal to 35 weeks gestation) live birth, were not using medications affecting glucose tolerance, and not planning another pregnancy or moving out of the area within the next 2 years. Participants who are free of type 2 diabetes and other serious medical conditions at baseline are screened for type 2 diabetes annually within the first 2 years after delivery. Recruitment began in September 2008 and ends in December 2011. Data are being collected through pregnancy and early postpartum telephone interviews, self-administered monthly mailed questionnaires (3-11 months postpartum), a telephone interview at 6 months, and annual in-person examinations at which a 75 g 2-hour OGTT is conducted, anthropometric measurements are obtained, and self- and interviewer-administered questionnaires are completed.</p> <p>Discussion</p> <p>This is the first, large prospective, community-based study involving a racially and ethnically diverse cohort of women with recent GDM that rigorously assesses lactation intensity and duration and examines their relationship to incident type 2 diabetes while accounting for numerous potential confounders not assessed previously.</p
piggybac- and PhiC31-Mediated Genetic Transformation of the Asian Tiger Mosquito, Aedes albopictus (Skuse)
The Asian tiger mosquito, Aedes albopictus, is a highly invasive mosquito and has spread from South East Asia to Europe, the United States and northern areas of Asia in the past 30 years. Aedes mosquitoes transmit a range of viral diseases, including dengue and chikungunya. Aedes albopictus is generally considered to be somewhat less of a concern in this regard than Aedes aegypti. However a recent mutation in the chikungunya virus dramatically increased its transmission by Aedes albopictus, causing an important outbreak in the Indian Ocean in 2006 that eventually reached Italy in 2007. This highlights the potential importance of this mosquito, which can thrive much further from the Equator than can Aedes aegypti. This paper describes the first genetic engineering of the Asian tiger mosquito. This is an essential step towards the development of genetics-based control methods against this mosquito, and also an invaluable tool for basic research. We describe both transposon-based and site-specific integration methods
Dietary intakes and food sources of fat and fatty acids in Guatemalan schoolchildren: A cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Consumption of healthy diets that contribute with adequate amounts of fat and fatty acids is needed for children. Among Guatemalan children, there is little information about fat intakes. Therefore, the present study sought to assess intakes of dietary fats and examine food sources of those fats in Guatemalan children.</p> <p>Methods</p> <p>The study subjects consisted of a convenience sample of 449 third- and fourth-grade schoolchildren (8-10 y), attending public or private schools in Quetzaltenango City, Guatemala. Dietary data was obtained by means of a single pictorial 24-h record.</p> <p>Results</p> <p>The percentages of total energy (%E) from total fat, saturated fat (SFA) and monounsaturated fat (MUFA) reached 29%E for total fat and 10%E for each SFA and MUFA, without gender differences. %E from fats in high vs. low-socio economic status (SES) children were significantly higher for boys, but not for girls, for total fat (p = 0.002) and SFA (p < 0.001). Large proportions of the children had low levels of intakes of some fatty acids (FA), particularly for n-3 FA, with >97% of all groups consuming less than 1%E from this fats. Fried eggs, sweet rolls, whole milk and cheese were main sources of total fat and, SFA. Whole milk and sweet bread were important sources of n-3 FA for high- and low-SES boys and girls, respectively. Fried plantain was the main source of n-3 FA for girls in the high-SES group. Fried fish, seafood soup, and shrimp, consumed only by boys in low amounts, were sources of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, which may explain the low intakes of these nutrients.</p> <p>Conclusions</p> <p>α-linolenic acid, EPA and DHA were the most limiting fatty acids in diets of Guatemalan schoolchildren, which could be partially explained by the low consumption of sources of these nutrients, particularly fish and seafood (for EPA and DHA). This population will benefit from a higher consumption of culturally acceptable foods that are rich in these limiting nutrients.</p
Entrepreneurial-intention constraint model: A comparative analysis among post-graduate management students in India, Singapore and Malaysia
YesAlthough literature on entrepreneurship has increasingly focused on intention-based models, not much emphasis has been laid on understanding the combined effect of contextual and situational factors along with support of university environment on the formation of entrepreneurial intention among students. In an effort to make up for this shortfall, by taking Theory of Planned Behavior as basic framework, the present study seeks to understand the influence of three of the most important factors, viz. (a) endogenous barriers, (b) exogenous environment, and (c) university environment and support on the entrepreneurial intention among management students. The study sample consisted of 1,097 students, wherein 526 students were from India, 252 from Singapore, and 319 were from Malaysia. The results indicates that along with positive attitude and perceived behavioral control that directly influences entrepreneurial intention, university environment and support and exogenous environment also have an indirect but significant impact on shaping of entrepreneurial intention among students. With this, it was found that exogenous environment was found to have a negative relationship with both attitude towards behavior and perceived behavioral control for all three countries.The full-text of this article will be released for public view at the end of the publisher embargo on 2 Jun 2018
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