bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Limit-Setting and Participation in Physical Activity on Youth Screen Time
Authors: Carlson Susan A. , Fulton Janet E. , Lee Sarah M. , Foley John T. , Heitzler Carrie , Huhman Marian 
Published: June 2010

OBJECTIVES:
To examine the associations of demographics, rules associated with television-viewing, and physical activity with daily screen time (including television, non–school-related computer use, and video games) in children and adolescents.

METHODS:
We analyzed data from a telephone survey of 7415 youth aged 9 to 15 years from the Youth Media Campaign Longitudinal Survey. We used logistic regression models to calculate odds of exceeding recommended screen-time limits (&gt;120 minutes/day) according to demographics, rules, and physical activity.

RESULTS:
Odds that children would exceed recommended screen-time limits were positively associated with age and black race/ethnicity and negatively associated with income level. Children and adolescents who reported that they really agreed that their parents had rules about time spent watching television and playing video games were less likely to exceed recommended limits than those who strongly disagreed that their parents had rules. Similarly, when parents reported always or very often having limits on television watching (versus rarely or never) and when parents correctly identified the recommended limits, children were less likely to exceed recommended limits. Children whose parents reported consistent limits and who themselves reported consistent rules about time spent watching television had the lowest prevalence of exceeding recommended limits. Odds that children would exceed recommended limits decreased as physical activity in the previous week increased.

CONCLUSIONS:
Parental rules regarding screen time and participation in physical activity play a role in the amount of screen time among children and adolescents. Programs that encourage limit-setting by parents and promote physical activity may reduce screen time among youth.
How Import Competition Affects Displaced Workers in the U.S.
Authors: Kandilov Ivan T 
Published: June 2010

Abstract
I use the Displaced Worker Survey and bilateral trade data to assess the impact of import competition from low-wage countries on displaced workers' unemployment duration and re-employment wages. While low-wage imports have almost no effect on unemployment duration for workers displaced from an industry with the average length of the quality ladder, I find that a ten percentage point increase in low-wage imports leads to a 5.6 week longer jobless spell duration for workers displaced from an industry with a short quality ladder. Similarly, a ten percentage point increase in low-wage imports leads to a 7.2 percent decline in re-employment wages for workers displaced from an average ladder industry, but it leads to an 11.3 percent decline in re-employment wages for workers displaced from a short ladder industry. I show evidence that greater low-wage imports raise the likelihood of sectoral relocation upon re-employment, leading to loss of sector specific human capital.
β-Cell Failure in Diet-Induced Obese Mice Stratified According to Body Weight Gain: Secretory Dysfunction and Altered Islet Lipid Metabolism Without Steatosis or Reduced β-Cell Mass
Authors: Peyot Marie-Line , Pepin Emilie , Lamontagne Julien , Latour Martin G. , Zarrouki Bader , Lussier Roxane , Pineda Marco , Jetton Thomas L. , Madiraju S.R. Murthy , Joly Erik , Prentki Marc 
Published: June 2010

OBJECTIVE
C57Bl/6 mice develop obesity and mild hyperglycemia when fed a high-fat diet (HFD). Although diet-induced obesity (DIO) is a widely studied model of type 2 diabetes, little is known about β-cell failure in these mice.

RESEARCH DESIGN AND METHODS
DIO mice were separated in two groups according to body weight gain: low- and high-HFD responders (LDR and HDR). We examined whether mild hyperglycemia in HDR mice is due to reduced β-cell mass or function and studied islet metabolism and signaling.

RESULTS
HDR mice were more obese, hyperinsulinemic, insulin resistant, and hyperglycemic and showed a more altered plasma lipid profile than LDR. LDR mice largely compensated insulin resistance, whereas HDR showed perturbed glucose homeostasis. Neither LDR nor HDR mice showed reduced β-cell mass, altered islet glucose metabolism, and triglyceride deposition. Insulin secretion in response to glucose, KCl, and arginine was impaired in LDR and almost abolished in HDR islets. Palmitate partially restored glucose- and KCl-stimulated secretion. The glucose-induced rise in ATP was reduced in both DIO groups, and the glucose-induced rise in Ca2+ was reduced in HDR islets relatively to LDR. Glucose-stimulated lipolysis was decreased in LDR and HDR islets, whereas fat oxidation was increased in HDR islets only. Fatty acid esterification processes were markedly diminished, and free cholesterol accumulated in HDR islets.

CONCLUSIONS
β-Cell failure in HDR mice is not due to reduced β-cell mass and glucose metabolism or steatosis but to a secretory dysfunction that is possibly due to altered ATP/Ca2+ and lipid signaling, as well as free cholesterol deposition.
Membrane Potential-Dependent Inactivation of Voltage-Gated Ion Channels in α-Cells Inhibits Glucagon Secretion From Human Islets
Authors: Ramracheya Reshma , Ward Caroline , Shigeto Makoto , Walker Jonathan N. , Amisten Stefan , Zhang Quan , Johnson Paul R. , Rorsman Patrik , Braun Matthias 
Published: June 2010

OBJECTIVE
To document the properties of the voltage-gated ion channels in human pancreatic α-cells and their role in glucagon release.

RESEARCH DESIGN AND METHODS
Glucagon release was measured from intact islets. [Ca2+]i was recorded in cells showing spontaneous activity at 1 mmol/l glucose. Membrane currents and potential were measured by whole-cell patch-clamping in isolated α-cells identified by immunocytochemistry.

RESULTS
Glucose inhibited glucagon secretion from human islets; maximal inhibition was observed at 6 mmol/l glucose. Glucagon secretion at 1 mmol/l glucose was inhibited by insulin but not by ZnCl2. Glucose remained inhibitory in the presence of ZnCl2 and after blockade of type-2 somatostatin receptors. Human α-cells are electrically active at 1 mmol/l glucose. Inhibition of KATP-channels with tolbutamide depolarized α-cells by 10 mV and reduced the action potential amplitude. Human α-cells contain heteropodatoxin-sensitive A-type K+-channels, stromatoxin-sensitive delayed rectifying K+-channels, tetrodotoxin-sensitive Na+-currents, and low-threshold T-type, isradipine-sensitive L-type, and ω-agatoxin-sensitive P/Q-type Ca2+-channels. Glucagon secretion at 1 mmol/l glucose was inhibited by 40–70% by tetrodotoxin, heteropodatoxin-2, stromatoxin, ω-agatoxin, and isradipine. The [Ca2+]i oscillations depend principally on Ca2+-influx via L-type Ca2+-channels. Capacitance measurements revealed a rapid (&lt;50 ms) component of exocytosis. Exocytosis was negligible at voltages below −20 mV and peaked at 0 mV. Blocking P/Q-type Ca2+-currents abolished depolarization-evoked exocytosis.

CONCLUSIONS
Human α-cells are electrically excitable, and blockade of any ion channel involved in action potential depolarization or repolarization results in inhibition of glucagon secretion. We propose that voltage-dependent inactivation of these channels underlies the inhibition of glucagon secretion by tolbutamide and glucose.
Ablation of 4E-BP1/2 Prevents Hyperglycemia-Mediated Induction of VEGF Expression in the Rodent Retina and in Müller Cells in Culture
Authors: Schrufer Tabitha L. , Antonetti David A. , Sonenberg Nahum , Kimball Scot R. , Gardner Thomas W. , Jefferson Leonard S. 
Published: June 2010

OBJECTIVE
Vascular endothelial growth factor (VEGF) contributes to diabetic retinopathy, but control of its expression is not well understood. Here, we tested the hypothesis that hyperglycemia mediates induction of VEGF expression in a eukaryotic initiation factor 4E (eIF4E) binding protein (4E-BP) 1 and 2 dependent manner.

RESEARCH DESIGN AND METHODS
The retina was harvested from control and type 1 diabetic rats and mice and analyzed for VEGF mRNA and protein expression as well as biomarkers of translational control mechanisms. Similar analyses were performed in Müller cell cultures exposed to hyperglycemic conditions. The effect of 4E-BP1 and 4E-BP2 gene deletion on VEGF expression was examined in mice and in mouse embryo fibroblasts (MEFs).

RESULTS
Whereas VEGF mRNA in the retina remained constant, VEGF expression was increased as early as 2 weeks after the onset of diabetes. Increases in expression of 4E-BP1 protein mirrored those of VEGF and expression of 4E-BP1 mRNA was unchanged. Similar results were observed after 10 h of exposure of cells in culture to hyperglycemic conditions. Importantly, the diabetes-induced increase in VEGF expression was not observed in mice deficient in 4E-BP1 and 4E-BP2, nor in MEFs lacking the two proteins.

CONCLUSIONS
Hyperglycemia induces VEGF expression through cap-independent mRNA translation mediated by increased expression of 4E-BP1. Because the VEGF mRNA contains two internal ribosome entry sites, the increased expression is likely a consequence of ribosome loading at these sites. These findings provide new insights into potential targets for treatment of diabetic retinopathy.
Synthesis and optical properties of self-assembled flower-like CdS architectures by mixed solvothermal process
Authors: Zhang Junhao , Wu Yuhui , Zhu Jia , Huang Shaoxing , Zhang Dongjing , Yin Qinghuan 
Published: June 2010

Abstract
Self-assembled CdS architectures with flower-like structures have been synthesized by a mixed solvothermal method using ethylene glycol and oleic acid as the mixed solvent at 160°C for 12 h. The results of X-ray diffraction (XRD) patterns, field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images indicate that the product exists as the hexagonal wurtzite phase and conatins of larger numbers of flower-like CdS architectures with diameters of 1.8–3 μm. The selected-area electron diffraction (SAED) pattern and the high resolution transmission electron microscope (HRTEM) image reveal that the grain has better crystallinity. The optical properties of flower-like CdS architectures were also investigated by ultraviolet-visable (UV-vis) and photoluminescence spectroscopy at room temperature. A strong peak at 490 nm is shown in the UV-vis absorption, while an emission at 486 nm and another strong emission at 712 nm are shown in the PL spectrum.
On the cosmological constant problem and brane-world geometry
Authors: Capistrano Abraão , Odon Pedro 
Published: June 2010

Abstract
The cosmological constant problem is examined within the context of the covariant brane-world gravity, based on Nash’s embedding theorem for Riemannian geometries. We show that the vacuum structure of the brane-world is more complex than General Relativity’s because it involves extrinsic elements, in specific, the extrinsic curvature. In other words, the shape (or local curvature) of an object becomes a relative concept, instead of the “absolute shape” of General Relativity. We point out that the immediate consequence is that the cosmological constant and the energy density of the vacuum quantum fluctuations have different physical meanings: while the vacuum energy density remains confined to the four-dimensional brane-world, the cosmological constant is a property of the bulk’s gravitational field that leads to the conclusion that these quantities cannot be compared, as it is usually done in General Relativity. Instead, the vacuum energy density contributes to the extrinsic curvature, which in turn generates Nash’s perturbation of the gravitational field. On the other hand, the cosmological constant problem ceases to be in the brane-world geometry, reappearing only in the limit where the extrinsic curvature vanishes.
The low temperature magnetic properties of potassium holmium double tungstate
Authors: Borowiec Mieczysław , Khatsko Eugene , Dyakonov Vladimir , Rykova Anna , Majchrowski Andrzej , Zayarnyuk Tetyana , Barański Marek , Żmija Józef , Szymczak Henryk 
Published: June 2010

Abstract
The magnetic investigations of potassium holmium double tungstate KHo(WO4)2 have been performed. The results of measurements of magnetic susceptibility and magnetization as a function of both temperature (T = 0.5–100 K) and magnetic field (up to 2 T) are presented.
Morphotaxonomy of fresh water Chlorophycean algae (Desmids) from Siddharth Nagar, U.P., India
Authors: Prakash J. , Kishore S. , Asthana D. K. , Mishra P. K. , Singh S. K. 
Published: June 2010

The taxonomic study of green algae (Desmids) of district Siddharth Nagar, Uttar Pradesh India reveals the presence of ten taxa belonging to family Desmidiaceae the Class Chlorophyceae. The Tal Kunda pond of Siddharth Nagar district showing rich algal diversity. The present paper deals only desmidiacean taxa. These desmids taxa (Euastrum ceylanicum E. spinulosum, Cosmarium quadrum, C. awadhense, Staurastrum gracile, S. sexangulare, Micrasterias zeylanica, M. foliacea, Pleurotaenium ehrenbergii and Desmidium swartzii) though known from other localities of lndia are recorded from district Siddharth Nagar Eastern Uttar Pradesh for the first time. Key words: Chlorophyceae; Fresh; water; Desmids doi: 10.3126/eco.v12i0.3193 Ecoprint: An International Journal of Ecology 12: 21-25, 2005
Phenology of macropytes of Sagar Lake (M.P.)
Authors: Gupta Arti 
Published: June 2010

The paper deals with phonological data of ten macrophyte species growing in Sagar Lake. Phenograms of Eichhornia crassipes, Hydrilla verticillata, Ipomiea aquatica, Jussiaea repens, Pistia stratiotes, Trapa bispinosa and Vallisneria spiralis have been presented. Key words: Phenology; Sagar Lake doi: 10.3126/eco.v12i0.3205 Ecoprint: An International Journal of Ecology 12: 89-90, 2005
Investigation of tensile–compressive yield asymmetry and the role of deformation twin in extruded pure magnesium
Authors: Sukedai E. , Yokoyama T. 
Published: June 2010

AbstractAn asymmetry in tensile–compressive yield behaviour of extruded 99.95 % pure magnesium at two different strain rates was investigated. The yield asymmetry was observed at both strain rates, and the compressive yield strengths were over 50 % lower than the corresponding tensile yield strengths. Examinations with transmission electron microscopy revealed that twin bands were observed in compression specimens, and the twinning system was {0112}<0111>. Fibre structures (or textures) were examined using both X-ray pole-figures, which enabled one to identify that the extrusion axis was parallel to <1010> directions. The Schmid factors on slip systems and the twinning system were estimated, i. e., the Schmid factor for {1101}<1120> slip system was maximum in tension, and that for the twinning system was highest in compression. The origin of the yield asymmetry in extruded pure magnesium is associated with both the highest Schmid factor for the twinning system in compression and the critical resolved shear stress for twinning, which is lower than that for slip.
Adsorption of nucleotides on the rutile (110) surface
Authors: Gemming Sibylle , Enyashin Andrey N. , Frenzel Johannes , Seifert Gotthard 
Published: June 2010

Abstract
The present study aims at the computer-aided design of suitably functionalized oxide surfaces for the integration of nanotubes into multi-purpose nano-electronic devices. The adsorption of the nucleotide cytidine monophosphate on the rutile (110) surface is investigated by density-functional-based tight-binding calculations. The nucleotide favors anchoring with two oxygen atoms of its phosphate part. Adsorption occurs preferentially at two neighboring five-fold coordinated Ti atoms along the [001] direction, thus opening a pathway to an ordered adsorption of nanotubes along [001]. The electronic densities of state show that the aromatic part of the cytidine residue remains unchanged upon adsorption on rutile. This implies that no significant changes occur in the nanotube binding capacity by -stacking of the aromatic part, hence, nucleotide-functionalized oxide surfaces are ideal substrates for the ordered, stable and electronically and chemically inert immobilization of nanotubes.
High-alloy ferritic cast irons with different graphite microstructures for exhaust manifolds and turbocharger housings
Authors: Li Delin 
Published: June 2010

Abstract
It is well known that ferritic cast irons with 4 to 5 wt.% Si provide good service and low cost in many elevated-temperature applications. In terms of cast iron microstructures, both spheroidal graphite and compacted graphite cast irons are currently used to produce engine exhaust manifolds and turbocharger housings. Between the two graphite morphologies, the mixed graphite microstructure has been proposed and evaluated in the aspects of molten metal treatment, solidification characteristic, microstructural stability, standard tensile testing, long-term hot oxidation and thermal cycling testing. The effects of graphite morphologies on the material properties are presented. The samples with mixed graphite structure showed an improved ductility at medium temperatures and thermal fatigue resistance.
Size effects resulting from local strain hardening; microstructural evaluation of Fe-3% Si and Cu deformed in tension and deep drawing using orientation gradient mapping (OGM)
Authors: Henning Mark , Vehoff Horst 
Published: June 2010

AbstractMesoscale strain hardening phenomena and the effect on the macroscale behavior (yield under tension, earing in deep drawing) are investigated in Fe-3 % Si and Cu.Fe-3 % Si shows a smooth upper and lower yield point depending on grain size and sheet thickness which can be attributed to a lack of mobile dislocations. A free surface effect (reduced strain hardening of near-surface regions) is found for sheets of 300 μm and 960 μm thickness, but limited to small and medium strains.By means of the new orientation gradient mapping, which is correlated with local strain hardening, the local deformation microstructure is investigated in incremental tensile tests and incremental deep drawing for Fe-3 % Si and Cu. The orientation gradient distribution significantly depends on the material. Based on these results phenomenological descriptions of the microstructure at the mesoscale are proposed. From orientation gradient mapping, geometrically necessary and statistical orientation gradients are evaluated which agree well with results of transmission electron microscopy investigations of geometrically necessary boundaries and incidental dislocation boundaries. A constitutive equation correlating orientation gradient mapping and local dislocation density is proposed.
An analysis of the differences in the acute hospitalization charges following minimally invasive versus open posterior lumbar interbody fusion
Authors: Wang Michael Y. , Cummock Matthew D. , Yu Yong , Trivedi Rikin A. 
Published: June 2010

ObjectMinimally invasive spine (MIS) procedures are increasingly being recognized as equivalent to open procedures with regard to clinical and radiographic outcomes. These techniques are also believed to result in less pain and disability in the immediate postoperative period. There are, however, little data to assess whether these procedures produce their intended result and even fewer objective data to demonstrate that they are cost effective when compared with open surgery.MethodsThe authors performed a retrospective analysis of hospital charges for 1- and 2-level MIS and open posterior interbody fusion for lumbar spondylotic disease, disc degeneration, and spondylolisthesis treated at a single academic medical center. Patients presenting with bilateral neurological symptoms were treated with open surgery, and those with unilateral symptoms were treated with MIS. Overall hospital charges and surgical episode–related charges, length of stay (LOS), and discharge status were obtained from the hospital finance department and adjusted for multi-/single-level surgeries.ResultsDuring a 14-month period, 74 patients (mean age 55 years) were treated. The series included 59 single-level operations (75% MIS and 25% open), and 15 2-level surgeries (53% MIS and 47% open). The demographic profile, including age and Charlson Comorbidity Index, were similar between the 4 groups. The mean LOS for patients undergoing single-level surgery was 3.9 and 4.8 days in the MIS and open cases, respectively (p = 0.017). For those undergoing 2-level surgery, the mean LOS was 5.1 for MIS versus 7.1 for open surgery (p = 0.259). With respect to hospital charges, single-level MIS procedures were associated with an average of $70,159 compared with $78,444 for open surgery (p = 0.027). For 2-level surgery, mean charges totalled $87,454 for MIS versus $108,843 for open surgery (p = 0.071). For single-level surgeries, 5 and 20% of patients undergoing MIS and open surgery, respectively, were discharged to inpatient rehabilitation. For 2-level surgeries, the rates were 13 and 29%, respectively.ConclusionsWhile hospital setting, treatment population, patient selection, and physician expectation play major roles in determining hospital charges and LOS, this pilot study at an academic teaching hospital shows trends for quicker discharge, reduced hospital charges, and lower transfer rates to inpatient rehabilitation with MIS. However, larger multicenter studies are necessary to validate these findings and their relevance across diverse US practice environments.
How to avoid wrong-level and wrong-side errors in lumbar microdiscectomy
Authors: Irace Claudio , Corona Claudio 
Published: June 2010

Object
When performing a single-level lumbar decompressive procedure, the first of all errors to avoid is operating at the wrong level or on the wrong side. In this report the authors describe their method of trying to minimize this potential risk.

Methods
A 3-step procedure—the IRACE (intraoperative radiograph and confirming exclamation) method—was designed and adopted for single-level lumbar decompressive surgeries. Before skin incision, a wire is placed in the spinous process and lateral fluoroscopy is performed. Subsequently and also before skin incision, the assistant nurse provides oral confirmation of the level and side. Additional fluoroscopic control is provided before starting the laminotomy. The clinical records of 818 consecutive patients who had undergone lumbar microdiscectomy as an initial operation between 2001 and 2005 were retrospectively reviewed. Surgical charts as well as clinical and neuroimaging follow-up data were analyzed.

Results
No patient clinically and/or neuroradiologically demonstrated a level or side error. In 1 (0.12%) of 818 surgical procedures a wrong level was initially explored. The absence of frank disc herniation and the discrepancy with preoperative neuroimages led to fluoroscopic control in this case, and the correct level was then approached. No clinically apparent method-related complications were registered.

Conclusions
The problem of an incorrect level or side in lumbar surgery remains unresolved. The authors propose a useful and easily applied procedure to reduce such a risk. Larger studies comparing different methods of avoiding such errors will probably lead to the definition and wide adoption of a surgical behavior aiming to reach a near-zero error rate.