Forecasting, Diagnosis and Decision Making with Neural Networks and Self-Organizing Maps

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Evaluation of explosive strength ability of the upper body for athletic throwers

Physical fitness evaluation of throwing athletes has been performed based on measurement items for the purpose of power evaluation of the lower limbs and whole body; however, the method for assessing the muscle strength and exertion of the upper body has not been acknowledged extensively. The purpose of this study was to examine the effectiveness of the evaluation of the explosive muscle performance of the upper body of an athlete using several measurement parameters, including push up jump (PJ), countermovement push up (CMPU) flight time, medicine ball throw (MBT), countermovement medicine ball throw, and one repetition maximum of the bench press (BP-1RM). The relationship between these measurement items and athletic performance as determined using the IAAF score was examined. Eleven male athletes training on a daily basis were enrolled. A significant positive correlation between MBT and athletic performance was observed, indicating the usefulness of physical fitness evaluation in athletes. Conversely, PJ and CMPU were not associated with athletic performance, suggesting that these parameters may be negatively affected by the subject’s weight. Further, BP-1RM did not show a significant correlation with athletic performance, owing to the fact that the exertion characteristics of one repetition maximum do not reflect the shrinkage rate of the muscle required for throwing. It is recommended that athletes select an event wherein their weight positively affects the competitive ability and does not affect measurement parameters. Further, explosive muscle performance without counter movements maybe incorporated into the physical fitness assessment of athletes

Determination of Stress Intensity Factor for Interface Crack under Uniform Heat Flow by Crack Tip Stress Method

This paper deals with the analysis of the thermal stress intensity factor for interfacial crack in dissimilar materials under uniform heat flow by using the finite element method. This method is based on the fact that the singular stress field near the interface crack tip is controlled by the stress values at the crack tip node calculated by FEM. The calculation shows that the present method has the sufficient accuracy in the interface crack problems under thermal stress.23rd International Congress of Theoretical and Applied Mechanics, August 19-24, 2012, Beijing, Chin

Designing a banking scale of human induced pluripotent stem cells based on suspension time-dependent quality variations in filling and cryopreservation processes

To establish a robust commercial production system for a cell product, it is necessary to investigate a lot of variable factors inside and outside of the system and discuss the cell manufacturability. In case of trying a scale-up of banking system for human induced pluripotent stem cells (hiPSCs), the process time to fill the cell suspension into vials before cryopreservation is prolonged. And that will cause the decay of the cell quality, because cryoprotective agent (CPA) including dimethyl sulfoxide has toxicity to cells. Based on such fluctuation of cell product quality derived from time-dependency in down-stream process, novel strategy to design a process time and a banking scale is required. In this study, four performance indexes, survival ratio of cells during suspension in CPA before cryopreservation (γ), survival ratio, attachment efficiency and specific growth rate of cells after cryopreservation (β, α and μ, respectively) are proposed to evaluate the cellular state and potential of the product. And, the quality variations of suspended cells in CPA are elucidated by changing the process time of suspension at room temperature and 4 °C. At room temperature, γ decreased with process time (ts) exponentially, being γ = 0.72 at ts = 6 h. With respect to α, 4 hours suspension at room temperature had an insignificant effect, however, it dropped after the lag-time, being α = 0.73 at ts = 6 h. In contrast, β and μ were kept high level of 0.80 and 5.3 × 10-2 h-1, respectively, similarly to those without the process. In addition, the suspension at 4°C made the enhancement of γ and α at ts = 6 h (γ = 0.88 and α = 1.08, respectively), suggesting that the suppression in cell activity during suspension is important to preserve the cell quality. In conclusion, the proposed performance indexes are useful to estimate the state and potential of cell product in filling and cryopreservation processes, and the temperature control in filling process is one of the promising factors to maintain the cell product quality. Please click Additional Files below to see the full abstract

Mice lacking sialyltransferase ST3Gal-II develop late-onset obesity and insulin resistance

Sialyltransferases are a family of 20 gene products in mice and humans that transfer sialic acid from its activated precursor, CMP-sialic acid, to the terminus of glycoprotein and glycolipid acceptors. ST3Gal-II (coded by the St3gal2 gene) transfers sialic acid preferentially to the three positions of galactose on the Galβ1-3GalNAc terminus of gangliosides GM1 and GD1b to synthesize GD1a and GT1b, respectively. Mice with a targeted disruption of St3gal2 unexpectedly displayed lateonset obesity and insulin resistance. At 3 months of age, St3gal2-null mice were the same weight as their wild type (WT) counterparts, but by 13 months on standard chow they were visibly obese, 22% heavier and with 37% greater fat/lean ratio than WT mice. St3gal2-null mice became hyperglycemic and displayed impaired glucose tolerance by 9 months of age. They had sharply reduced insulin responsiveness despite equivalent pancreatic islet morphology. Analyses of insulin receptor (IR) tyrosine kinase substrate IRS-1 and downstream target Akt revealed decreased insulininduced phosphorylation in adipose tissue but not liver or skeletal muscle of St3gal2-null mice. Thin-layer chromatography and mass spectrometry revealed altered ganglioside profiles in the adipose tissue of St3gal2-null mice compared to WT littermates. Metabolically, St3gal2-null mice display a reduced respiratory exchange ratio compared to WT mice, indicating a preference for lipid oxidation as an energy source. Despite their altered metabolism, St3gal2-null mice were hyperactive. We conclude that altered ganglioside expression in adipose tissue results in diminished IR sensitivity and late-onset obesity.Fil: Lopez, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Johns Hopkins University School of Medicine; Estados UnidosFil: Aja, Susan. Johns Hopkins University School of Medicine; Estados UnidosFil: Aoki, Kazuhiro. University of Georgia; GreciaFil: Seldin, Marcus M.. Johns Hopkins University School of Medicine; Estados UnidosFil: Lei, Xia. Johns Hopkins University School of Medicine; Estados UnidosFil: Ronnett, Gabriele V. Johns Hopkins University School of Medicine; Estados UnidosFil: Wong, G. William. Johns Hopkins University School of Medicine; Estados UnidosFil: Schnaar, Ronald L.. Johns Hopkins University School of Medicine; Estados Unido

Cardiorespiratory fitness and the incidence of type 2 diabetes: a cohort study of Japanese male athletes

BACKGROUND: In Japan, although the incidence of overweight (BMI ≥ 25) is still low compared with that in Europe and the United States, the prevalence of type 2 diabetes has increased over the last 15 years,. In both Japanese and Caucasian populations it has been reported that a high level of cardiorespiratory fitness protects against the development of type 2 diabetes. However, there are no reports focused specifically on athletes that investigate whether high cardiorespiratory fitness at a young age can prevent disease later in life. We examined the relationship between cardiorespiratory fitness at a young age and the development of type 2 diabetes in Japanese athletes using a cohort study. METHODS: The cardiorespiratory fitness of male alumni of the physical education department of Juntendo University, as measured by stored data of a 1,500-m endurance run in college (1971–1991) was compared with their incidence of type 2 diabetes as determined by follow-up questionnaires (2007–2009). This study used Cox’s proportional hazards models and adjusted for age, year of graduation, BMI, smoking, and sports club participation at college age. RESULTS: We collected data on cardiorespiratory fitness at college age and medical history survey data during 2007–2009 from 570 male alumni. The median follow-up period was 26 years (IQR: 23–29 years), and 22 men had developed type 2 diabetes. An inverse relationship was observed between incidence of type 2 diabetes and level of cardiorespiratory fitness at time of college after adjustment for age, year of graduation, BMI, smoking, and sports participation. The adjusted hazards ratio and 95% CI by category (low, medium, and high) were 1.00 (reference), 0.40 (0.14–1.13) and 0.26 (0.07–1.00) (p = 0.03 for trend). CONCLUSIONS: A high level of cardiorespiratory fitness at a young age can help prevent type 2 diabetes later in life

Distinct predictive performance of Rac1 and Cdc42 in cell migration.

We propose a new computation-based approach for elucidating how signaling molecules are decoded in cell migration. In this approach, we performed FRET time-lapse imaging of Rac1 and Cdc42, members of Rho GTPases which are responsible for cell motility, and quantitatively identified the response functions that describe the conversion from the molecular activities to the morphological changes. Based on the identified response functions, we clarified the profiles of how the morphology spatiotemporally changes in response to local and transient activation of Rac1 and Cdc42, and found that Rac1 and Cdc42 activation triggers laterally propagating membrane protrusion. The response functions were also endowed with property of differentiator, which is beneficial for maintaining sensitivity under adaptation to the mean level of input. Using the response function, we could predict the morphological change from molecular activity, and its predictive performance provides a new quantitative measure of how much the Rho GTPases participate in the cell migration. Interestingly, we discovered distinct predictive performance of Rac1 and Cdc42 depending on the migration modes, indicating that Rac1 and Cdc42 contribute to persistent and random migration, respectively. Thus, our proposed predictive approach enabled us to uncover the hidden information processing rules of Rho GTPases in the cell migration

An essential role for the SHIP2-dependent negative feedback loop in neuritogenesis of nerve growth factor–stimulated PC12 cells

The local accumulation of phosphatidylinositol (3,4,5) trisphosphate (PIP3) and resulting activation of Rac1/Cdc42 play a critical role in nerve growth factor (NGF)–induced neurite outgrowth. To further explore the mechanism, we visualized PIP3, phosphatidylinositol (3,4) bisphosphate, and Rac1/Cdc42 activities by fluorescence resonance energy transfer (FRET) imaging in NGF-stimulated PC12 cells. Based on the obtained FRET images, and with the help of in silico kinetic reaction model, we predicted that PI-5-phosphatase negatively regulates PIP3 upon NGF stimulation. In agreement with this model, depletion of Src homology 2 domain–containing inositol polyphosphate 5-phosphatase 2 (SHIP2) markedly potentiated NGF-induced Rac1/Cdc42 activation and PIP3 accumulation and considerably increased the number and the length of neurites in phosphate and tensin homologue–depleted PC12 cells. Further refinement of the computational model predicted Rac1 regulation of PI3-kinase and SHIP2, which was also validated experimentally. We propose that the SHIP2-mediated negative feedback on PIP3 coordinately works with the PI3-kinase–mediated positive feedback to form an initial protrusive pattern and, later, to punctuate the PIP3 accumulation to maintain proper neurite outgrowth