233 research outputs found

    Solving Ratio-Dependent Predator-Prey System with Constant Effort Harvesting using Variational Iteration Method

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    Due to wide range of interest in use of bio-economic models to gain insight into the scientific management of renewable resources like fisheries and forestry,variational iteration method (VIM) is employed to approximate the solution of the ratio-dependent predator-prey system with constant effort prey harvesting.The results are compared with the results obtained by Adomian decomposition method and reveal that VIM is very effective and convenient for solving nonlinear differential equations

    The effects of combined magnesium and zinc supplementation on metabolic status in patients with type 2 diabetes mellitus and coronary heart disease

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    Background: The present research aimed to analyze the impacts of magnesium and zinc supplements on glycemic control, serum lipids, and biomarkers of oxidative stress and inflammation in patients suffering from coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). Methods: According to the research design, a randomized, double-blind, placebo-controlled trial has been implemented on 60 subjects suffering from CHD and T2DM. Therefore, participants have been randomly divided into 2 groups for taking placebo (n = 30) or 250 mg magnesium oxide plus 150 mg zinc sulfate (n = 30) for 12 weeks. Results: Magnesium and zinc significantly decreased fasting plasma glucose (FPG) (β - 9.44 mg/dL, 95 CI, - 18.30, - 0.57; P = 0.03) and insulin levels (β - 1.37 μIU/mL, 95 CI, - 2.57, - 0.18; P = 0.02). Moreover, HDL-cholesterol levels significantly enhanced (β 2.09 mg/dL, 95 CI, 0.05, 4.13; P = 0.04) in comparison to the placebo. There was an association between magnesium and zinc intake, and a significant decrease of C-reactive protein (CRP) (β - 0.85 mg/L, 95 CI, - 1.26, - 0.45; P < 0.001), a significant increase in total nitrite (β 5.13 μmol/L, 95 CI, 1.85, 8.41; P = 0.003) and total antioxidant capacity (TAC) (β 43.44 mmol/L, 95 CI, 3.39, 83.50; P = 0.03) when compared with placebo. Furthermore, magnesium and zinc significantly reduced the Beck Depression Inventory index (BDI) (β - 1.66; 95 CI, - 3.32, - 0.009; P = 0.04) and Beck Anxiety Inventory (BAI) (β - 1.30; 95 CI, - 2.43, - 0.16; P = 0.02) when compared with the placebo. Conclusions: In patients with T2DM and CHD, the 12-week intake of magnesium plus zinc had beneficial effects on FPG, HDL-cholesterol, CRP, insulin, total nitrite, TAC levels, and BDI and BAI score. This suggests that magnesium and zinc co-supplementation may be beneficial for patients with T2DM and CHD. Further studies on more patients and lasting longer are needed to determine the safety of magnesium and zinc co-supplementation. Trial registration: Current Controlled Trials http://www.irct.ir: IRCT20130211012438N31 at 11 May 2019 of registration. This study retrospectively registered. © 2020 The Author(s)

    Synthesis and characterization of (zinc-layered-gallate) nanohybrid using structural memory effect

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    The memory effect of calcined zinc hydroxide nitrate, with gallate anion solutions, was studied. The layered hydroxide salt material, zinc hydroxide nitrate was heat-treated at 150–800 °C. XRD analysis showed the growth of the calcined materials in both thickness and diameter occurring simultaneously with increasing calcination temperature. Surface area analysis confirmed this growth. The rehydration behavior of the calcined material was investigated by placing the material in a solution containing gallate anions. The best result for layered hydroxide salt phase reconstruction was obtained for a sample heated at 500 °C and treated with 0.1 mol L−1 anion. PXRD analysis showed the formation of a layered structure material after rehydration process. FTIR and TG confirmed the formation of the host–guest nanohybrid material produced

    Treniranje u uvjetima kontinuuma otežavajućega kontekstualnog utjecaja: usporedba triju različitih načina vježbanja na satovima tjelesne i zdravstvene kulture u osnovnim školama

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    Few studies have explored the contextual interference effect with children. The findings from these investigations have produced inconsistent results. The purpose of this study was to investigate further how the contextual interference effect influenced children learning a fundamental motor skill in a physical education class. Elementary students (N=36) practiced overarm throwing following traditional blocked or random scheduling. They were compared to a third group of participants practicing the same tasks following a schedule with systematic increases in contextual interference. Analysis revealed that all three groups improved during practice. Post-test results revealed performance differences in favor of the group that practiced with systematic increases in contextual interference. The findings reported here extend the results of previous studies by demonstrating that children can learn a motor skill by practicing with systematic increases in contextual interference. Theoretical considerations are discussed, as well as the relevance of the findings for practitioners and avenues for future research.Premalo je istraživanja koja su ispitivala učinke kontekstualnog utjecaja na učenje motoričkih znanja u djece. Rezultati tih istraživanja bili su proturječni. Cilj ovog istraživanja bilo je daljnje istraživanje učinaka kontekstualnog utjecaja na djecu koja uče osnovna motorička znanja na nastavi tjelesne i zdravstvene kulture. Učenici osnovnih škola (N=36) vježbali su osnovno bacanja loptice jednom rukom iznad glave u uvjetima tradicionalne, blokirane ili nasumične strukture kontekstualnog utjecaja. Rezultati tih učenika uspoređeni su s rezultatima treće grupe ispitanika koji su izvodili/vježbali isti motorički zadatak u uvjetima sustavnog povećanja otežavajućega kontekstualnog utjecaja. Rezultati su pokazali da su sve tri grupe ispitanika napredovale tijekom vježbanja. Rezultati finalnog mjerenja pokazali su također da je veći napredak zabilježen u grupi koja je vježbala u uvjetima sustavnog povećanja otežavajućega kontekstualnog utjecaja. Rezultati ovog istraživanja proširuju spoznaje dosadašnjih znanstvenih istraživanja ukazivanjem na činjenicu da djeca mogu učiti motorička znanja u uvjetima sustavnog povećanja otežavajućega kontekstualnog utjecaja. U članku su raspravljene teorijske osnove eksperimenta i praktičan doprinos dobivenih znanstvenih spoznaja te su predstavljene preporuke za daljnja znanstvena istraživanja

    Behavior of expanded polystyrene (EPS) blocks under cyclic pavement foundation loading

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    This study introduces a mechanism for initial assessment and future development to improve understanding of expanded polystyrene (EPS) behavior as a super-lightweight material for road construction. Large scale cyclic plate load tests on model pavements were performed. The effect of several factors including thickness of soil, thickness of subsequent EPS layers and density of EPS on the surface deformations, resilient modulus (Mr) and interlayer pressure transfer were investigated. The results indicated that, compared to a covering soil layer of 300 mm, the rut depth on the loading surface reduced by 13.5% and 40.8% when the soil thickness was increased by 33% and 100%, respectively. With a constant soil thickness, increasing the thickness of an upper (denser) EPS layer with respect to a bottom (softer) EPS layer, from 200 mm to 600 mm, would only result in a 20% decrease in the peak settlements after loading. Resilient modulus of the system was found to be dependent on soil thickness. A designer can choose an appropriate resilient modulus assuming the soil-EPS composite acts as subgrade or subbase. In order to extend the results to a wider range of geofoams, soils and layer thicknesses, a simple stress analysis method was also trialed

    Identifying crossing collagen fibers in human corneal tissues using pSHG images

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    Polarization sensitive second harmonic generation (pSHG) microscopy has been used previously to characterize the structure of collagen fibers in corneal samples. Due to the typical organization of the corneal stroma, the information that pSHG provides may be misleading in points where two different collagen fiber bundles orient along different direction crossings. Here, a simulation that illustrates the problem is presented, along with a novel method that is capable of identifying these crossing points. These results can be used to improve the evaluation of corneal collagen structure, and it has been applied to analyze pSHG data acquired from healthy and keratoconic human corneal samples

    Spitzer Observations of the North Ecliptic Pole

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    We present a photometric catalog for Spitzer Space Telescope warm mission observations of the North Ecliptic Pole (NEP; centered at R.A.=18h00m00s\rm R.A.=18^h00^m00^s, Decl.=66d33m38s.552\rm Decl.=66^d33^m38^s.552). The observations are conducted with IRAC in 3.6 μ\mum and 4.5 μ\mum bands over an area of 7.04 deg2^2 reaching 1σ\sigma depths of 1.29 μ\muJy and 0.79 μ\muJy in the 3.6 μ\mum and 4.5 μ\mum bands respectively. The photometric catalog contains 380,858 sources with 3.6 μ\mum and 4.5 μ\mum band photometry over the full-depth NEP mosaic. Point source completeness simulations show that the catalog is 80% complete down to 19.7 AB. The accompanying catalog can be utilized in constraining the physical properties of extra-galactic objects, studying the AGN population, measuring the infrared colors of stellar objects, and studying the extra-galactic infrared background light.Comment: 10 pages, 11 figures and 3 tables. Accepted to the ApJ

    Gaps in detailed knowledge of human papillomavirus (HPV) and the HPV vaccine among medical students in Scotland

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    &lt;p&gt;Background: A vaccination programme targeted against human papillomavirus (HPV) types16 and 18 was introduced in the UK in 2008, with the aim of decreasing incidence of cervical disease. Vaccine roll out to 12–13 year old girls with a catch-up programme for girls aged up to 17 years and 364 days was accompanied by a very comprehensive public health information (PHI) campaign which described the role of HPV in the development of cervical cancer.&lt;/p&gt; &lt;p&gt;Methods: A brief questionnaire, designed to assess acquisition of knowledge of HPV infection and its association to cervical cancer, was administered to two different cohorts of male and female 1st year medical students (school leavers: 83% in age range 17–20) at a UK university. The study was timed so that the first survey in 2008 immediately followed a summer's intensive PHI campaign and very shortly after vaccine roll-out (150 students). The second survey was exactly one year later over which time there was a sustained PHI campaign (213 students).&lt;/p&gt; &lt;p&gt;Results: We addressed three research questions: knowledge about three specific details of HPV infection that could be acquired from PHI, whether length of the PHI campaign and/or vaccination of females had any bearing on HPV knowledge, and knowledge differences between men and women regarding HPV. No female student in the 2008 cohort had completed the three-dose vaccine schedule compared to 58.4% of female students in 2009. Overall, participants’ knowledge regarding the sexually transmitted nature of HPV and its association with cervical cancer was high in both year groups. However, in both years, less than 50% of students correctly identified that HPV causes over 90% of cases of cervical cancer. Males gave fewer correct answers for these two details in 2009. In 2008 only around 50% of students recognised that the current vaccine protects against a limited subset of cervical cancer-causing HPV sub-types, although there was a significant increase in correct response among female students in the 2009 cohort compared to the 2008 cohort.&lt;/p&gt; &lt;p&gt;onclusions: This study highlights a lack of understanding regarding the extent of protection against cervical cancer conferred by the HPV vaccine, even among an educated population in the UK who could have a vested interest in acquiring such knowledge. The intensive PHI campaign accompanying the first year of HPV vaccination seemed to have little effect on knowledge over time. This is one of the first studies to assess detailed knowledge of HPV in both males and females. There is scope for continued improvements to PHI regarding the link between HPV infection and cervical cancer.&lt;/p&gt

    Short-term effect of kinesiology taping on pain, functional disability and lumbar proprioception in individuals with nonspecific chronic low back pain: a double-blinded, randomized trial

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    Background: This study aimed to evaluate the effect of kinesiology taping (KT) on lumbar proprioception, pain, and functional disability in individuals with nonspecific chronic low back pain (CLBP). Methods: Thirty individuals with nonspecific CLBP participated in this double-blinded, randomized clinical trial from July 2017 to September 2018. The participants were randomized into two groups: KT (n = 15) and placebo group (n = 15). KT was applied with 15�25 tension for 72 h, and placebo taping was used without tension. Lumbar repositioning error was measured by a bubble inclinometer at three different angles (45° and 60° flexion, and 15° extension) in upright standing. Pain and disability were assessed by the Short-Form McGill Pain Questionnaire and Oswestry Disability Index, respectively. All measurements were recorded at baseline and 3 days after taping. Results: Pain and disability scores reduced 3 days after taping in the KT group with large effect sizes (p 0.05). Also, only constant error of 15° extension showed a moderate correlation with disability (r = 0.39, p = 0.02). Conclusion: KT can decrease pain and disability scores after 3 days of application. Although placebo taping can reduce pain, the effect of KT is higher than placebo taping. The findings do not support the therapeutic effect of KT and placebo taping as a tool to enhance lumbar proprioception in patients with nonspecific CLBP. Trial registration: The study prospectively registered on 21.05.2018 at the Iranian Registry of Clinical Trials: IRCT20090301001722N20. © 2020, The Author(s)

    Validation of the Munich Actimetry Sleep Detection Algorithm for estimating sleep-wake patterns from activity recordings

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    © 2021 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Periods of sleep and wakefulness can be estimated from wrist-locomotor activity recordings via algorithms that identify periods of relative activity and inactivity. Here, we evaluated the performance of our Munich Actimetry Sleep Detection Algorithm. The Munich Actimetry Sleep Detection Algorithm uses a moving 24-h threshold and correlation procedure estimating relatively consolidated periods of sleep and wake. The Munich Actimetry Sleep Detection Algorithm was validated against sleep logs and polysomnography. Sleep-log validation was performed on two field samples collected over 54 and 34 days (median) in 34 adolescents and 28 young adults. Polysomnographic validation was performed on a clinical sample of 23 individuals undergoing one night of polysomnography. Epoch-by-epoch analyses were conducted and comparisons of sleep measures carried out via Bland-Altman plots and correlations. Compared with sleep logs, the Munich Actimetry Sleep Detection Algorithm classified sleep with a median sensitivity of 80% (interquartile range [IQR] = 75%-86%) and specificity of 91% (87%-92%). Mean onset and offset times were highly correlated (r = .86-.91). Compared with polysomnography, the Munich Actimetry Sleep Detection Algorithm reached a median sensitivity of 92% (85%-100%) but low specificity of 33% (10%-98%), owing to the low frequency of wake episodes in the night-time polysomnographic recordings. The Munich Actimetry Sleep Detection Algorithm overestimated sleep onset (~21 min) and underestimated wake after sleep onset (~26 min), while not performing systematically differently from polysomnography in other sleep parameters. These results demonstrate the validity of the Munich Actimetry Sleep Detection Algorithm in faithfully estimating sleep-wake patterns in field studies. With its good performance across daytime and night-time, it enables analyses of sleep-wake patterns in long recordings performed to assess circadian and sleep regularity and is therefore an excellent objective alternative to sleep logs in field settings.ASL received a stipend from the Max‐Weber‐Programm (Studienstiftung), AMB received funding from the Graduate School of Systemic Neurosciences Munich, CR received funding from the Fundação para a Ciência e Tecnologia (FCT) PhD research grants (PDE/BDE/114584/2016), LKP received a fellowship from the Coordenação de Aperfeiçoamento Pessoal de Nível Superior (CAPES, Finance Code 001), and NG received research funding from the FoeFoLe program at LMU (registration No. 37/2013).info:eu-repo/semantics/publishedVersio
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