bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discovery of two distinct red clumps in NGC 419: a rare snapshot of a cluster at the onset of degeneracy
Authors: Girardi Léo , Rubele Stefano , Kerber Leandro 
Published: February 2009

Abstract
Colour–magnitude diagrams (CMDs) of the Small Magellanic Cloud (SMC) star cluster NGC 419, derived from Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) data, reveal a well-delineated secondary clump located below the classical compact red clump typical of intermediate-age populations. We demonstrate that this feature belongs to the cluster itself, rather than to the underlying SMC field. Then, we use synthetic CMDs to show that it corresponds very well to the secondary clump predicted to appear as a result of He-ignition in stars just massive enough to avoid e--degeneracy settling in their H-exhausted cores. The main red clump instead is made of the slightly less massive stars which passed through e- degeneracy and ignited He at the tip of the red giant branch. In other words, NGC 419 is the rare snapshot of a cluster while undergoing the fast transition from classical to degenerate H-exhausted cores. At this particular moment of a cluster's life, the colour distance between the main-sequence turn-off and the red clump(s) depends sensitively on the amount of convective core overshooting, Λc. By coupling measurements of this colour separation with fits to the red clump morphology, we are able to estimate simultaneously the cluster mean age (1.35+0.11-0.04 Gyr) and overshooting efficiency (Λc= 0.47+0.14-0.04). Therefore, clusters like NGC 419 may constitute important marks in the age scale of intermediate-age populations. After eye inspection of other CMDs derived from HST/ACS data, we suggest that the same secondary clump may also be present in the Large Magellanic Cloud clusters NGC 1751, 1783, 1806, 1846, 1852 and 1917.
Direct numerical simulations of the galactic dynamo in the kinematic growing phase
Authors: Gissinger Christophe , Fromang Sebastien , Dormy Emmanuel 
Published: February 2009

AbstractWe present kinematic simulations of a galactic dynamo model based on the large-scale differential rotation and the small-scale helical fluctuations due to supernova explosions. We report for the first time direct numerical simulations of the full galactic dynamo using an unparametrized global approach. We argue that the scale of helicity injection is large enough to be directly resolved rather than parametrized. While the actual superbubble characteristics can only be approached, we show that numerical simulations yield magnetic structures which are close to both the observations and the previous parametrized mean field models. In particular, the quadrupolar symmetry and the spiraling properties of the field are reproduced. Moreover, our simulations show that the presence of a vertical inflow plays an essential role to increase the magnetic growth rate. This observation could indicate an important role of the downward flow (possibly linked with galactic fountains) in sustaining galactic magnetic fields.
The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
Authors: Łokas Ewa L. 
Published: February 2009

Abstract
We model the large kinematic data sets for the four Milky Way dwarf spheroidal (dSph) satellites: Carina, Fornax, Sculptor and Sextans, recently published by Walker et al. The member stars are selected using a reliable dynamical interloper removal scheme tested on simulated data. Our member selection is more restrictive than the one based on metallicity indicators as it removes not only contamination due to Milky Way stars but also the unbound stars from the tidal tails. We model the cleaned data sets by adjusting the solutions of the Jeans equations to the profiles of the projected velocity dispersion and kurtosis. The data are well reproduced by models where mass follows light and the best-fitting stellar orbits are isotropic to weakly tangential, as expected from the tidal stirring scenario. The Fornax dwarf, with more than 2400 member stars, is a dSph galaxy with the most accurately determined mass to date: its 1σ error following from the sampling errors of the velocity moments is below 5 per cent. With mass-to-light ratio of 97 solar units, Sextans seems to be the most dark matter dominated of the four dSph galaxies.
A turbulent model of gamma-ray burst variability
Authors: Narayan Ramesh , Kumar Pawan 
Published: February 2009

Abstract
A popular paradigm to explain the rapid temporal variability observed in gamma-ray burst (GRB) light curves is the internal shock model. We propose an alternative model in which the radiating fluid in the GRB shell is relativistically turbulent with a typical eddy Lorentz factor γt. In this model, all pulses in the gamma-ray light curve are produced at roughly the same distance R from the centre of the explosion. The burst duration is ∼R/cΓ2, where Γ is the bulk Lorentz factor of the expanding shell, and the duration of individual pulses in the light curve is ∼R/cΓ2γ2t. The model naturally produces highly variable light curves with ∼γ2t individual pulses. Even though the model assumes highly inhomogeneous conditions, nevertheless the efficiency for converting jet energy to radiation is high.
Nurse practitioner practice patterns for exercise counseling
Authors: Tompkins Tawnya Horsley , Belza Basia , Brown Marie‐Annette 
Published: February 2009

AbstractPurpose:  To describe nurse practitioner (NP) practice patterns for exercise counseling for adults.Data sources:  Using a cross‐sectional design, participants completed a self‐administered questionnaire that ascertained barriers and facilitators encountered when providing exercise counseling. Participants included 398 NPs, who averaged 11 years in practice (SD = 7.9) and worked in a variety of practice areas.Conclusions:  In a given week, about half (48%) of the NPs counseled more than 50% of their patients for exercise. The majority of participants (84%) agreed that exercise counseling is as valuable an intervention as prescribed medication. More than half (59%) of the participants exercised regularly. Barriers and facilitators to exercise counseling were predominately a patient’s lack of interest and the length of the patient visit. Specific strategies were identified for older adults and individuals residing in rural areas who may require more tailored exercise counseling. Participants demonstrated strong values about exercise counseling and observed that exercise had clear benefits for their patients. NP respondents offered recommendations focused on safety and adherence that can be used to improve exercise counseling.Clinical implications:  Exercise is a crucial component of preventative health care. Studies have shown that healthcare provider recommendations can be effective in helping patients increase their exercise and activity.
The effectiveness of a peer‐mentored older adult fitness program on perceived physical, mental, and social function
Authors: Dorgo Sandor , Robinson Kristynia M , Bader Julia 
Published: February 2009

AbstractPurpose:  The purpose of this research was to compare changes in perceived physical, mental, and social function measured by the Short Form‐36 (SF36vr2) in a group of older adults who were trained by peer mentors (PMs) versus a similar group trained by qualified kinesiology student mentors (SMs).Data sources:  We conducted a two‐arm repeated measures longitudinal intervention and collected data for 87 PM and 44 SM participants. Pre‐ and post‐training subscale scores were computed for all eight subscales and the two summary physical and mental component scores. The percentage differences in the 10 scores were used as the response variables.Conclusions:  After a 14‐week physical fitness intervention, perceived physical, mental, and social functioning improved significantly (p < .05) for the PM group, but not for the SM group (p > .06). Thus, older adults who participated in a physical fitness program with peer support perceived (a) overall improvement in physical and mental well‐being; (b) better social functioning, (c) enhanced ability to carry out physical and emotional roles, (d) improved general health, and (e) increased level of vitality. Thus, we conclude that peer‐mentored exercise programs for older adults are superior to programs mentored by young professionals and may lead to increased adherence.Implications for practice:  Nurse practitioners routinely prescribe exercise while educating older adults about the benefits of an active lifestyle; however, older adults often remain sedentary and exhibit poor adherence to exercise. One potential solution is to use peer support. Two factors that can improve adherence are availability of structured exercise programs for the older adult and peer mentoring.
Efficacy of different plasma sources in the treatment of thrombotic thrombocytopenic purpura
Authors: Pereira A. 
Published: February 2009

Plasma exchange (PE) with fresh frozen plasma (FFP) is the treatment of choice for thrombotic thrombocytopenic purpura (TTP). Since TTP patients are exposed to a large number of plasma donors, they would benefit from any additional measure of plasma safety. Several such measures have been implemented but doubts remain as to whether the new types of plasma are as effective as FFP or whether some plasma fraction may be more effective. Cryoprecipitate‐poor plasma (CCP) was introduced in the therapeutics of TTP as a superior alternative to FFP. However, a clinical trial by the Canadian Apheresis Group failed to confirm the therapeutic superiority of CPP over FFP. Quarantine FFP (qFFP) is as effective as chemically modified plasma in the prevention of HIV, HBV and HCV transmission. Since qFFP has not been chemically manipulated, it must be regarded as equivalent to FFP both in terms of protein composition and therapeutic efficacy. Solvent/detergent (SD) plasma has long been used in the treatment of TTP and seems to be as effective as FFP. However, the only formal proof of efficacy consist in a small trial involving only 26 patients. Methylene blue‐photoinactivated plasma (MBPIP) is used in some regions in Spain and other European countries. A recent multicentric, ‘quasi experimental’ trial involving 102 cases of idiopathic TTP has shown that MBPIP is less effective than qFFP. Patient in the MBPIP arm required twice as many PE procedures and more adjuvant therapies to achieve remission and had a higher risk of TTP recrudescence. There is only one randomized trial comparing psoralen‐photoinactivated plasma to FFP. Though no difference was found in the rate of TTP remission, the trial recruited only 35 patients and was therefore severely underpowered. Levels of ADAMTS13 activity, as measured by the current laboratory assays, are similar in the various plasma sources despite some (i.e. MBPIP) are clinically less effective. In conclusion, FFP and qFFP are the plasma sources of choice for PE in TTP. CPP is probably as effective as FFP. MBPIP should be avoided because it is less effective. There is no proof that SD‐plasma and psoralen‐photoinactivated plasma are therapeutically equivalent to FFP. Normal levels of ADAMTS13 in therapeutic plasma seem not to be an accurate proxy of clinical effectiveness.
Hypoxia, melanocytes and melanoma – survival and tumor development in the permissive microenvironment of the skin
Authors: Bedogni Barbara , Powell Marianne Broome 
Published: February 2009

SummaryThe tissue microenvironment plays a critical role in cell survival and growth and can contribute to cell transformation and tumor development. Cellular interactions with the stroma and with other cells provide key signals that control cellular arrest or division, survival or death, and entrance or exit from a quiescent state. Together, these decisions are essential for maintenance of tissue homeostasis. Tissue oxygenation is an important component of the microenvironment that can acutely alter the behavior of a cell through the direct regulation of genes involved in cell survival, apoptosis, glucose metabolism, and angiogenesis. Loss of tissue homeostasis due to, for example, oncogene activation leads to the disruption of these signals and eventually can lead to cell transformation and tumor development. Here we review the role of tissue oxygenation, and in particular physiologic skin hypoxia, on cell survival and senescence and how it contributes to melanocyte transformation and melanoma development.
Five‐year incidence of visual impairment and blindness in older Icelanders: the Reykjavik Eye Study
Authors: Gunnlaugsdottir Elin , Arnarsson Arsaell , Jonasson Fridbert 
Published: February 2009

Abstract.Purpose:  This study examined age, sex and cause‐specific 5‐year incidence of visual impairment and blindness in a middle‐aged and elderly Icelandic population.Methods:  The study cohort consisted of a population‐based, random sample of citizens aged ≥ 50 years. Of 1379 eligible subjects, 1045 underwent a baseline examination in 1996; 846 of the 958 survivors (88.2%) underwent a 5‐year follow‐up examination in 2001. All participants underwent an extensive ophthalmological examination including best corrected visual acuity (BCVA) using a Snellen chart. We used World Health Organization (WHO) criteria, which define visual impairment as BCVA in the better eye of < 6/18 and ≥ 3/60 and blindness as BCVA in the better eye of < 3/60. We also used US criteria, which consider BCVA of < 6/12 and > 6/60 in the better eye to represent visual impairment and BCVA of ≤ 6/60 in the better eye to represent blindness. The causes of incident visual loss in either eye were determined. Deterioration or improvement in vision were defined as a loss or gain of ≥ 2 Snellen lines.Results:  According to WHO criteria, 5‐year incidence of bilateral visual impairment and blindness were 1.07% (95% confidence interval [CI] 0.37–1.76) and 0.35% (95% CI 0.00–0.76), respectively. Using US criteria, equivalent incidence of bilateral visual impairment and blindness were 3.49% (95% CI 2.24–4.74) and 0.95% (95% CI 0.29–1.60), respectively. Age‐related macular degeneration and cataract were the major causes of incident visual impairment and blindness.Conclusions:  Incidences of visual impairment and blindness increased significantly with age. Age‐related macular degeneration, present in 75% of affected persons, was the most common cause of 5‐year incident legal blindness in this middle‐aged and elderly Icelandic population.
Clinical Evaluation of the Daily Assessment of Symptoms‐Anxiety (DAS‐A): A New Instrument to Assess the Onset of Symptomatic Improvement in Generalized Anxiety Disorder
Authors: Feltner Douglas E. , Harness Jane , Brock Jerri , Sambunaris Angelo , Cappelleri Joseph C. , Morlock Robert 
Published: February 2009

Introduction: Rapid onset of symptomatic improvement is a desirable characteristic of new generalized anxiety disorder (GAD) treatments. A validated rating scale is needed to assess GAD symptoms during the first days of treatment.Aims: To provide clinical data to support the validation of the Daily Assessment of Symptoms‐Anxiety (DAS‐A), a new instrument to assess onset of symptomatic improvement in GAD.Methods: We assessed the ability of the DAS‐A to detect onset of symptomatic improvement during the first week of therapy in 169 GAD patients randomized to paroxetine 20 mg/day, lorazepam 4.5 mg/day, or placebo for 4 weeks.Results: On the primary outcome measure, average change from baseline over the first 6 days of DAS‐A assessments, lorazepam (−14.5 ± 1.8 [LS mean, SE]; P= 0.006 vs. placebo) showed a significant improvement versus placebo (−7.85 ± 1.7), whereas paroxetine (−8.3 ± 1.7; P= 0.83 vs. placebo) did not. Lorazepam produced a significant treatment effect on the DAS‐A at 24 h (P= 0.0004), whereas paroxetine did not (P= 0.5666). Both active drugs produced statistically significant improvement versus placebo on the DAS‐A total change score (last‐observation carried forward method; LOCF, endpoint). On the DAS‐A total change score (observed cases analysis), lorazepam produced statistically significant improvement versus placebo at weeks 1, 2, and 4 (P < 0.05; no week 3 visit), whereas paroxetine, separated from placebo at weeks 2 and 4 (P < 0.05). Both active drugs produced results on the Hamilton Anxiety Rating Scale (HAM‐A) at weeks 1 through 4 that were similar to those found on the DAS‐A.Conclusions: These data indicate that the DAS‐A can detect symptomatic improvement in GAD patients treated with lorazepam during the first week of treatment, and, in a secondary analysis, as early as 24 h.
Relationship between vitamin D, calcium and parathyroid hormone in Cape Town
Authors: Haarburger D , Hoffman M , Erasmus R T , Pillay T S 
Published: February 2009

Aim:The aim of this study was to test the hypothesis that vitamin D deficiency is associated with abnormal levels of calcium and parathyroid hormone (PTH).Methods:Vitamin D requests at a tertiary hospital in South Africa over 2 years were retrospectively analysed along with calcium and PTH levels.Results:Only when the 25-hydroxyvitamin D (25(OH)D) level dropped below 25 nmol/l, was there a significant rise in PTH. A subnormal 25(OH)D level was also not always related to hypocalcaemia, as more than half of patients with their 25(OH)D level below 25 nmol/l had calcium levels in the reference range. However, all patients with calcium levels below 1.8 mmol/l were shown to have vitamin D insufficiency.Conclusion:Hypovitaminosis D may co-exist with a blunted PTH response. Therefore, assumptions about vitamin D status should not be made based on PTH and calcium values. 25(OH)D measurements should be requested when vitamin D deficiency is clinically suspected, irrespective of biochemical results.
31P NMR and ESI-MS studies of metal ion-phosphorus pesticide residue complexes
Authors: Koo In Sun , Ali Dildar , Yang Kiyull , Park Yong , Esbata Abdelhamid , vanLoon Gary W. , Buncel Erwin 
Published: February 2009

31P NMR and ESI-MS structural studies have been carried out for O,O-dimethylphosphorothioate anion (PA–) interacting with Ag+, Hg2+, and Na+ cations. Evidence is presented for the formation of PA–···Ag+ and PA–···Hg2+ metal complexes and for ionic PA–Na+, with 31P chemical shift values of 43, 40, and 65 ppm, respectively. The 31P chemical shifts for PA–···Ag+ and PA–···Hg2+ complexes exhibit an initial sharp rise as the [Ag+]/[PA] and [Hg2+]/[PA] ratio increases from 0 to 1.0 and 0 to 0.5, respectively, and remain almost constant beyond these ratios. These results indicate the formation of 1:1 PA–···Ag+ and 2:1 (PA–)2···Hg2+ complexes. Electrospray ionization mass spectroscopy (ESI-MS) revealed peaks corresponding to [O-P(=S)(OCH3)2 + Ag + H]+ and {2[O-P(=S)(OCH3)2] + Hg + H}+ for PAH interacting with Ag+ and Hg2+, supporting the 1:1 PA–···Ag+ and 2:1 (PA–)2···Hg2+ stoichiometry. The experimental results support the predominance of species with greater P=O double bond and P–S single bond character, relative to P-O/P=S. Our results on 31P NMR chemical shifts have a bearing on the use of 31P chemical shifts as a tool for organophosphorus pesticide identification.
Investigations of the supramolecular host properties of a fluorescent bistren cage compound
Authors: Boland Patricia G. , Accardi Sara J. , Snow Carrie A. , Wagner Brian D. 
Published: February 2009

The host properties of a bistren cage compound, previously reported to be an efficient anion sensor, are shown to include encapsulation of small aromatic guest molecules. It is also shown that the intrinsic fluorescence of this cage compound, arising from the anthracenyl moiety in its structure, is sensitive to the encapsulation of aromatic guests in aqueous solution and can be used to measure the binding constants for any such guest. This makes this bistren cage a rare example of a fluorescent host for aromatic guests, and suggests potential applications of this compound as a versatile fluorescent sensor for a variety of guests of interest. The binding of a number of benzene derivatives was studied; these were all found to form 1:2 host–guest inclusion complexes with a wide range in total binding constants (K1K2), from 6.4 × 103 to 3.5 × 107 (mol/L)–2, indicating a significant degree of selectivity for different benzene derivatives. The binding strength was found to depend on both the guest polarity and aqueous solubility.
Bradykinin-Induced Dilation of Human Coronary Arterioles Requires NADPH Oxidase–Derived Reactive Oxygen Species
Authors: Larsen Brandon T. , Bubolz Aaron H. , Mendoza Suelhem A. , Pritchard Kirkwood A. , Gutterman David D. 
Published: February 2009

Objective—Hydrogen peroxide (H2O2) is an endothelium-derived hyperpolarizing factor in human coronary arterioles (HCAs). H2O2mediates bradykinin (BK)-induced vasodilation and reduces bioavailability of epoxyeicosatrienoic acids (EETs); however, the cellular and enzymatic source of H2O2is unknown.Methods and Results—NADPH oxidase expression was determined by immunohistochemistry. Superoxide and H2O2production was assayed in HCAs and human coronary artery endothelial cells (HCAECs) using dihydroethidium and dichlorodihydrofluorescein histofluorescence, respectively. Superoxide was quantified by HPLC separation of dihydroethidium products. Diameter changes of HCAs were measured by videomicroscopy. NADPH oxidase subunits Nox1, Nox2, Nox4, p22, p47, and p67 were each expressed in HCA endothelium. In HCAs or HCAECs incubated with dihydroethidium and dichlorodihydrofluorescein, BK induced superoxide and H2O2formation, which was inhibited by gp91ds-tat or apocynin but not by gp91scram-tat or rotenone. HPLC analysis confirmed that BK specifically induced superoxide production. Gp91ds-tat reduced vasodilation to BK but not to papaverine. 14,15-EEZE (an EET antagonist) further reduced the residual dilation to BK in the presence of gp91ds-tat, but had no effect in the presence of gp91scram-tat, suggesting that NADPH oxidase–derived ROS modulate EET bioavailability.Conclusion—We conclude that endothelial NADPH oxidase is a functionally relevant source of H2O2that mediates agonist-induced dilation in the human heart.