4,905 research outputs found
Birth outcome in relation to licorice consumption during pregnancy.
A role for glucocorticoids is suspected in the etiology of low birth weight. The authors tested whether maternal consumption of glycyrrhizin (an inhibitor of cortisol metabolism) in licorice affects birth weight in humans. A sample of 1,049 Finnish women and their healthy singleton infants was studied in 1998. Glycyrrhizin intake was calculated from detailed questionnaires on licorice consumption. Glycyrrhizin exposure was grouped into three levels: low ( or =500 mg/week; n = 110). Birth weight and gestational age (from ultrasound measurements) were obtained from hospital records. Babies with heavy exposure to glycyrrhizin were not significantly lighter at birth, but they were significantly more likely to be born earlier: The odds ratio for being born before 38 weeks' gestation was 2.5 (95% confidence interval: 1.1, 5.5; p = 0.03). Although the effect of heavy glycyrrhizin intake on mean duration of gestation was small (2.52 days) when expressed as an effect on the mean, this shift to the left of the distribution of duration of gestation was sufficient to double the risk of being born before 38 weeks. The association remained in multivariate analyses. In conclusion, heavy glycyrrhizin exposure during pregnancy did not significantly affect birth weight or maternal blood pressure, but it was significantly associated with lower gestational age
The Lived Experiences of Native Louisiana French Speakers Entering English-Only Elementary Schools in Lower Bayou Lafourche
The purpose of this hermeneutic phenomenological study was to investigate the lived experiences of native Louisiana French speakers entering English-only elementary schools in lower Bayou Lafourche, Louisiana. Native Louisiana French speakers entering English-only elementary school was defined as those whose home language was Louisiana French prior to entering elementary school. While language attrition for non-English speakers and Louisiana French culture had been explored, the in depth, lived experiences of native Louisiana French speakers entering English elementary schools were unexplored (Blyth, 1997; Ryon, 2002; Sexton, 2000). Understanding how entering English-only schools affects student perceptions and identity was important in determining school policy as it relates to minority populations (DeJong, 2006; Halic, Greenberg, & Paulus, 2009; Wang, 2009). The eight persons participating in the study were native Louisiana French speakers who entered English-only elementary schools in lower Bayou Lafourche, LA, utilizing purposeful sampling and snowball method. The data collection methods included interview, questionnaire, focus groups, and audio journal. Data analysis was carried out according to hermeneutic phenomenological approach guidelines and processes. Thematic analysis revealed four themes: confusion and fear the first days of school, physical punishment for speaking French in school, humble early lives and reflective wish for bi-literacy and language transmission
Chern number spins of Mn acceptor magnets in GaAs
We determine the effective total spin of local moments formed from
acceptor states bound to Mn ions in GaAs by evaluating their magnetic Chern
numbers. We find that when individual Mn atoms are close to the sample surface,
the total spin changes from to , due to quenching of the
acceptor orbital moment. For Mn pairs in bulk, the total depends on the
pair orientation in the GaAs lattice and on the separation between the Mn
atoms. We point out that Berry curvature variation as a function of local
moment orientation can profoundly influence the quantum spin dynamics of these
magnetic entities.Comment: 4 pages, 3 figure
Magnetic properties of substitutional Mn in (110) GaAs surface and subsurface layers
Motivated by recent STM experiments, we present a theoretical study of the
electronic and magnetic properties of the Mn-induced acceptor level obtained by
substituting a single Ga atom in the (110) surface layer of GaAs or in one of
the atoms layers below the surface. We employ a kinetic-exchange tight-binding
model in which the relaxation of the (110) surface is taken into account. The
acceptor wave function is strongly anisotropic in space and its detailed
features depend on the depth of the sublayer in which the Mn atom is located.
The local-density-of-states (LDOS) on the (110) surface associated with the
acceptor level is more sensitive to the direction of the Mn magnetic moment
when the Mn atom is located further below the surface. We show that the total
magnetic anisotropy energy of the system is due almost entirely to the
dependence of the acceptor level energy on Mn spin orientation, and that this
quantity is strongly dependent on the depth of the Mn atom.Comment: 14 pages, 13 figure
Magnetic interactions of substitutional Mn pairs in GaAs
We employ a kinetic-exchange tight-binding model to calculate the magnetic
interaction and anisotropy energies of a pair of substitutional Mn atoms in
GaAs as a function of their separation distance and direction. We find that the
most energetically stable configuration is usually one in which the spins are
ferromagnetically aligned along the vector connecting the Mn atoms. The
ferromagnetic configuration is characterized by a splitting of the topmost
unoccupied acceptor levels, which is visible in scanning tunneling microscope
studies when the pair is close to the surface and is strongly dependent on pair
orientation. The largest acceptor splittings occur when the Mn pair is oriented
along the symmetry direction, and the smallest when they are oriented
along . We show explicitly that the acceptor splitting is not simply
related to the effective exchange interaction between the Mn local moments. The
exchange interaction constant is instead more directly related to the width of
the distribution of all impurity levels -- occupied and unoccupied. When the Mn
pair is at the (110) GaAs surface, both acceptor splitting and effective
exchange interaction are very small except for the smallest possible Mn
separation.Comment: 25 figure
Clinical trials in older people
Randomised controlled trials (RCTs) usually provide the best evidence for treatments and management. Historically, older people have often been excluded from clinical medication trials due to age, multimorbidity and disabilities. The situation is improving, but still the external validity of many trials may be questioned. Individuals participating in trials are generally less complex than many patients seen in geriatric clinics. Recruitment and retention of older participants are particular challenges in clinical trials. Multiple channels are needed for successful recruitment, and especially individuals experiencing frailty, multimorbidity and disabilities require support to participate. Cognitive decline is common, and often proxies are needed to sign informed consent forms. Older people may fall ill or become tired during the trial, and therefore, special support and empathic study personnel are necessary for the successful retention of participants. Besides the risk of participants dropping out, several other pitfalls may result in underestimating or overestimating the intervention effects. In nonpharmacological trials, imperfect blinding is often unavoidable. Interventions must be designed intensively and be long enough to reveal differences between the intervention and control groups, as control participants must still receive the best normal care available. Outcome measures should be relevant to older people, sensitive to change and targeted to the specific population in the trial. Missing values in measurements are common and should be accounted for when designing the trial. Despite the obstacles, RCTs in geriatrics must be promoted. Reliable evidence is needed for the successful treatment, management and care of older people.Non peer reviewe
Statin Treatment Is Associated With a Neutral Effect on Health-Related Quality of Life Among Community-Dwelling Octogenarian Men : The Helsinki Businessmen Study
Background: Statin treatment is common among 80+ people, but little is known about statin effects on health-related quality of life (HRQoL) in this oldest age group. Methods: In the Helsinki Businessmen Study (HBS), men born from 1919 to 1934 (original n = 3,490), have been followed-up since the 1960s. In 2015, a questionnaire about lifestyle, diseases, and medications, and including RAND-36/SF-36 HRQoL instrument was mailed to survivors. About 612 men (72.6%) responded, 530 of them reporting their medications (98% community-living). Propensity score analysis was used to compare statin users and nonusers for HRQoL. Results: We compared 229 current statin users (median age 85 years, interquartile range 84-88 years) with 301 nonusers (86; 84-89 years). Current statin users had had significantly higher serum cholesterol level in midlife (p <.001), but current lifestyle-related characteristics were similar in users and nonusers. Statin users reported more hypertension (61.1%, p <.001), diabetes (23.6%, p Conclusions: Our study suggests that statin treatment has no significant effect on health-related quality of life among octogenarian, community-dwelling men. The results contradict concerns about statin treatment in the oldest-old, and may caution against deprescribing of statins due to old age alone.Peer reviewe
Magnetic Anisotropy of Isolated Cobalt Nanoplatelets
Motivated in part by experiments performed by M.H. Pan et al. (nanoletters,
v.5, p 83, 2005), we have undertaken a theoretical study of the the magnetic
properties of two-monolayer thick Co nanoplatelets with an equilateral
triangular shape. The analysis is carried out using a microscopic Slater-Koster
tight-binding model with atomic exchange and spin-orbit interactions designed
to realistically capture the salient magnetic features of large nanoclusters
containing up to 350 atoms. Two different truncations of the FCC lattice are
studied, in which the nanoplatelet surface is aligned parallel to the FCC (111)
and (001)crystal planes respectively. We find that the higher coordination
number in the (111) truncated crystal is more likely to reproduce the
perpendicular easy direction found in experiment. Qualitatively, the most
important parameter governing the anisotropy of the model is found to be the
value of the intra-atomic exchange integral J. If we set the value of J near
the bulk value in order to reproduce the experimentally observed magnitude of
the magnetic moments, we find both quasi-easy-planes and perpendicular easy
directions. At larger values of J we find that the easy-axis of magnetization
is perpendicular to the surface, and the value of the magnetic anisotropy
energy per atom is larger. The possible role of hybridization with substrate
surface states in the experimental systems is discussed.Comment: 15 pages, 13 figure
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