2,558 research outputs found

    Average values of L-functions in characteristic two

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    AbstractGauss made two conjectures about average values of class numbers of orders in quadratic number fields, later on proven by Lipschitz and Siegel. A version for function fields of odd characteristic was established by Hoffstein and Rosen. In this paper, we extend their results to the case of even characteristic. More precisely, we obtain formulas of average values of L-functions associated to orders in quadratic function fields over a constant field of characteristic two, and then derive formulas of average class numbers of these orders

    Development and validation of the short-form Adolescent Health Promotion Scale.

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    BACKGROUND: Health-promoting lifestyle choices of adolescents are closely related to current and subsequent health status. However, parsimonious yet reliable and valid screening tools are scarce. The original 40-item adolescent health promotion (AHP) scale was developed by our research team and has been applied to measure adolescent health-promoting behaviors worldwide. The aim of our study was to examine the psychometric properties of a newly developed short-form version of the AHP (AHP-SF) including tests of its reliability and validity. METHODS: The study was conducted in nine middle and high schools in southern Taiwan. Participants were 814 adolescents randomly divided into two subgroups with equal size and homogeneity of baseline characteristics. The first subsample (calibration sample) was used to modify and shorten the factorial model while the second subsample (validation sample) was utilized to validate the result obtained from the first one. The psychometric testing of the AHP-SF included internal reliability of McDonald's omega and Cronbach's alpha, convergent validity, discriminant validity, and construct validity with confirmatory factor analysis (CFA). RESULTS: The results of the CFA supported a six-factor model and 21 items were retained in the AHP-SF with acceptable model fit. For the discriminant validity test, results indicated that adolescents with lower AHP-SF scores were more likely to be overweight or obese, skip breakfast, and spend more time watching TV and playing computer games. The AHP-SF also showed excellent internal consistency with a McDonald's omega of 0.904 (Cronbach's alpha 0.905) in the calibration group. CONCLUSION: The current findings suggest that the AHP-SF is a valid and reliable instrument for the evaluation of adolescent health-promoting behaviors. Primary health care providers and clinicians can use the AHP-SF to assess these behaviors and evaluate the outcome of health promotion programs in the adolescent population

    [The influence of parental healthy behaviors on healthy lifestyles of early adolescents].

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    BACKGROUND: Family behavior models may influence health promoting conducts among adolescents. AIM: To determine the association between health promoting behaviors among parents and healthy behaviors of early adolescents. MATERIAL AND METHODS: Analysis of the baseline assessment of a longitudinal study of early adolescents in the city of San Felipe, Region of Valparaiso, Chile. Parents and their teenage children, attending 5th to 7th grade, from ten municipal schools, participated in this study. Self-reported questionnaires were used to assess healthy lifestyles, answered separately by parents and their children. Univariable and multivariable ordinal logistic regression analyses with complete data were carried out, using the students� health promoting behaviors as dependent variables and the same behaviors among parents as the main predictors, controlling for other personal and family variables. RESULTS: We contacted 1,035 parents and 682 consented to participate along with 560 students. The mean age of adolescents was 11.5 ± 1.2 years (49% females) The mean age of parents was 39.8 ± 8.8 years and 90% were women. The parental behaviors associated with teenage health promoting behaviors were eating vegetables (odds ratio (OR) = 1.22, p < 0.05), having breakfast (OR = 1.27, p < 0.05), do stretching exercises every day (OR = 1.19, p < 0.05) and take some time for relaxation (OR = 1.24, p < 0.05). CONCLUSIONS: These results show an association between healthy behaviors among parents and these behaviors among their adolescent offspring

    The prevalence of chronic dehydration and associated with cardiometabolic risks among agriculture and aquaculture workers

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    BackgroundChronic dehydration is associated with complications and mortality in acute ischemic stroke patients. Prior literature indicates that farmers and fishery workers are commonly affected by cardiometabolic diseases and there is a need for early prevention of stroke. This study explores the prevalence of dehydration and the association of cardiometabolic risk profiles in agricultural and aquaculture workers.MethodsWe conducted a community-based, cross-sectional study of agriculture and aquaculture workers in Yunlin County of Taiwan between August 1 and December 31, 2021. Data on demographic characteristics and health-related lifestyles were collected through one-on-one interviews using a questionnaire. The threshold for dehydration is defined as serum osmolality ≥295 mOsm/kg, and physiological biomarkers were collected from a collaborating hospital. Multivariable logistic regression analyses adjusted for demographic characteristics were performed to investigate the association between dehydration levels, cardiometabolic risks, and health-related behaviors.ResultsA total of 962 Taiwanese agriculture and aquaculture workers who were predominantly women (65%) with a mean age of 64 years (SD = 13.8) were enrolled. The findings showed a high prevalence of dehydration (36%), metabolic syndrome (44.5%), abnormal waist circumference (64.4%), and abnormal blood pressure (68.5%). Multivariate logistic regression demonstrated that dehydration was significantly associated with metabolic syndrome (p &lt; 0.001), 10-year stroke risk prediction (p &lt; 0.001), and an unhealthy lifestyle (p &lt; 0.001).ConclusionThe prevalence of chronic dehydration was higher in Taiwanese agriculture and aquaculture workers, which was significantly associated with cardiometabolic risks and unhealthy lifestyles

    IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line

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    BACKGROUND: Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. RESULTS: In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). CONCLUSION: IGF-1 or dephosphorylated IGFBP-1/IGF-1 supplement does result in an anti-apoptotic effect for early embryo development in culture, with a subsequent increased total cell number resulting from cell culture. The effect is beneficial for the later establishment of a stem-cell line

    Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling

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    <p>Abstract</p> <p>Background</p> <p>Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed to determine the difference in pullout strength between conical and cylindrical screws based on the aforementioned cement augmentation techniques. The potential loss of fixation upon partial screw removal after screw insertion was also examined.</p> <p>Method</p> <p>The Taguchi method with an L<sub>8 </sub>array was employed to determine the significance of design factors. Conical and cylindrical pedicle screws with solid or cannulated designs were installed using two different screw augmentation techniques: solid screws with retrograde cement pre-filling and cannulated screws with cement injection through perforation. Uniform synthetic bones (test block) simulating severe osteoporosis were used to provide a platform for each screw design and cement augmentation technique. Pedicle screws at full insertion and after a 360-degree back-out from full insertion were then tested for axial pullout failure using a mechanical testing machine.</p> <p>Results</p> <p>The results revealed the following 1) Regardless of the screw outer geometry (conical or cylindrical), solid screws with retrograde cement pre-filling exhibited significantly higher pullout strength than did cannulated screws with cement injection through perforation (<it>p </it>= 0.0129 for conical screws; <it>p </it>= 0.005 for cylindrical screws). 2) For a given cement augmentation technique (screws without cement augmentation, cannulated screws with cement injection or solid screws with cement pre-filling), no significant difference in pullout strength was found between conical and cylindrical screws (<it>p ></it>0.05). 3) Cement infiltration into the open cell of the test block led to the formation of a cement/bone composite structure. Observations of the failed specimens indicated that failure occurred at the composite/bone interface, whereas the composite remained well bonded to the screws. This result implies that the screw/composite interfacial strength was much higher than the composite/bone interfacial strength. 4) The back-out of the screw by 360 degrees from full insertion did not decrease the pullout strength in any of the studied cases. 5) Generally, larger standard deviations were found for the screw back-out cases, implying that the results of full insertion cases are more repeatable than those of the back-out cases.</p> <p>Conclusions</p> <p>Solid screws with retrograde cement pre-filling offer improved initial fixation strength when compared to that of cannulated screws with cement injection through perforation for both the conically and cylindrically shaped screw. Our results also suggest that the fixation screws can be backed out by 360 degrees for intra-operative adjustment without the loss of fixation strength.</p

    Investigation of a Potential Scintigraphic Tracer for Imaging Apoptosis: Radioiodinated Annexin V-Kunitz Protease Inhibitor Fusion Protein

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    Radiolabeled annexin V (ANV) has been widely used for imaging cell apoptosis. Recently, a novel ANV-Kunitz-type protease inhibitor fusion protein, ANV-6L15, was found to be a promising probe for improved apoptosis detection based on its higher affinity to phosphatidylserine (PS) compared to native ANV. The present paper investigates the feasibility of apoptosis detection using radioiodinated ANV-6L15. Native ANV and ANV-6L15 were labeled with iodine-123 and iodine-125 using Iodogen method. The binding between the radioiodinated proteins and erythrocyte ghosts or chemical-induced apoptotic cells was examined. ANV-6L15 can be radioiodinated with high yield (40%−60%) and excellent radiochemical purity (>95%). 123I-ANV-6L15 exhibited a higher binding ratio to erythrocyte ghosts and apoptotic cells compared to 123I-ANV. The biodistribution of 123I-ANV-6L15 in mice was also characterized. 123I-ANV-6L15 was rapidly cleared from the blood. High uptake in the liver and the kidneys may limit the evaluation of apoptosis in abdominal regions. Our data suggest that radiolabled ANV-6L15 may be a better scintigraphic tracer than native ANV for apoptosis detection

    Social skills deficits and their association with Internet addiction and activities in adolescents with attention-deficit/hyperactivity disorder

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    The aims of this study were to examine the association between social skills deficits and Internet addiction and activities in adolescents with attention-deficit/hyperactivity disorder (ADHD) as well as the moderators for this association. Methods A total of 300 adolescents, aged between 11 and 18 years, who had been diagnosed with ADHD participated in this study. Their Internet addiction levels, social skills deficits, ADHD, parental characteristics, and comorbidities were assessed. The various Internet activities that the participants engaged in were also examined. Results The associations between social skills deficits and Internet addiction and activities and the moderators of these associations were examined using logistic regression analyses. Social skills deficits were significantly associated with an increased risk of Internet addiction after adjustment for the effects of other factors [odds ratio (OR) = 1.049, 95% confidence interval (CI) = 1.030–1.070]. Social skills deficits were also significantly associated with Internet gaming and watching movies. The maternal occupational socioeconomic levels of the participants moderated the association between social skills deficits and Internet addiction. Conclusions Social skills deficits should be considered targets in prevention and intervention programs for treating Internet addiction among adolescents with ADHD
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