Age-Related Differences between Maximum Flight Height of Basic Skills on Floor, Beam and Vault and Physical Condition of Youth Female Artistic Gymnasts

In women's artistic gymnastics, difficult elements with great flight heights have to be performed on the apparatuses. However, the importance of the physical condition for generating flight height and its development with age remains elusive. Therefore, we investigated the age-related differences of lower body power, reactive strength, 20 m sprint speed, flight heights (basic elements on beam and floor) and run-up speed on the vault of 33 youth female gymnasts. Further, we calculated correlations between all parameters separately for different age groups (7-9 y; 10-12 y; 13-15 y). We found larger differences between the age groups 7-9 y and 10-12 y than between 10-12 y and 13-15 y on the apparatuses (10-12 y vs. 7-9 y: +23% to +52%; 13-15 y vs. 10-12 y: +2% to +24%) and for physical conditioning variables (10-12 y vs. 7-9 y: +12 to +24%; 13-15 y vs. 10-12 y: + 5% to +16%). The correlations between flight heights and physical condition were the lowest for age group 7-9 y (r: from -0.47 to 0.78; 10-12 y: r: from -0.19 to 0.80; 13-15 y: r: from -0.20 to 0.90). An optimal application of the physical condition to enhance the gymnastics-specific performance (e.g., flight height) is strongly age-dependent. Regular monitoring of jumping abilities and the derivation of training recommendations can accelerate this development and the future performance of young athletes.

Loss of expression of protein kinase C beta is a common phenomenon in human malignant melanoma: a result of transformation or differentiation?

As with most cancers, the aetiology of human cutaneous melanoma is likely to be multifactorial and to include the accumulation of irreversible alterations in an unknown number of genes. Elucidating this molecular progression necessitates both the identification of genetic perturbations at each clinically relevant stage, and the assessment of their impact on the normal melanocyte. The observation that the epidermal melanocyte, in contrast to metastatic melanoma cells, requires activation of the protein kinase C (PKC) pathway to facilitate growth in vitro indicates that one or more isoforms (or substrates) of this large and complex family of proteins are among those that undergo alteration during the development of malignant melanoma. Consequently, a number of studies have investigated the expression of various PKC family members in both melanocyte and melanoma cell lines, without a consensus of opinion as to which isoforms are of biological significance in melanoma development and progression. The present study involved a comprehensive evaluation of the PKC profile in normal melanocytes and in 16 metastatic melanoma cell lines. The results show that the major difference in isoform expression between epidermal melanocytes and melanoma cells is the loss of PKCbeta protein expression in 90% of melanoma cell lines. Examination of PKCbeta in benign and malignant melanocytic lesions revealed that this protein is either downregulated or absent in both naevi and metastatic melanomas. We conjecture that, although the loss of PKCbeta expression is a common phenomenon in malignant melanocytes, it may be related more to a normal process of melanocytic differentiation than to malignant transformation.

Cell cycle arrest and apoptosis of melanoma cells by docosahexaenoic acid: association with decreased pRb phosphorylation

The incidence of cutaneous malignant melanoma is undergoing a dramatic increase in persons with light-color skin in all parts of the world. The prognosis for individuals with advanced disease is dismal due to the lack of effective treatment options. Thus, there is a need for new approaches to control tumor progression. Epidemiological, experimental, and mechanistic data implicate omega-6 polyunsaturated fatty acids (PUFAs) as stimulators and long-chain omega-3 PUFAs as inhibitors of development and progression of a range of human cancers, including melanoma. The aim of this study was to assess the mechanisms by which docosahexaenoic acid (DHA), an omega-3 PUFA, affects human melanoma cells. Exponentially growing melanoma cell lines were exposed in vitro to DHA and then assessed for (a) inhibition of cell growth; (b) expression of cyclins and cyclin-dependent kinase inhibitors in individual cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to cyclin D1, cyclin E, p21WAF1/CIP1, or p27(KIP1); and (c) expression of total pRb(T) independent of phosphorylation state and hypophosphorylated pRb(P-) in fixed cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to pRb(T) or pRb(P-), respectively. After treatment with increasing concentrations of DHA, cell growth in a majority of melanoma cell lines (7 of 12) was inhibited, whereas in 5 of 12 cell lines, cell growth was minimally affected. Two melanoma cell lines were examined in detail, one resistant (SK-Mel-29) and one sensitive (SK-Mel-110) to the inhibitory activity of DHA. SK-Mel-29 cells were unaffected by treatment with up to 2 microg/ml DHA whether grown in the absence or presence of 1% fetal bovine serum (FBS). No appreciable change was observed in cell growth, cell cycle distribution, the status of pRb phosphorylation, cyclin D1 expression, or the levels of the cyclin-dependent kinase inhibitors p21 and p27. In contrast, SK-Mel-110 cell growth was inhibited by DHA with the cells accumulating either in G1 or S phase: 0% in SK-Mel-29 versus 13.3 or 41.2% in SK-Mel-110 in the absence or presence of FBS, respectively. In the absence of serum, considerable death occurred by apoptosis. In addition, DHA treatment resulted in increasing numbers of SK-Mel-110 cells (from 12 to >40%) expressing hypophosphorylated pRb, whereas the levels of cyclin D1 and p21 changed little. Expression of p27 in these cells increased >2.5 times when grown in the absence of FBS but not in the presence of 1% FBS. Thus, we show for the first time that DHA inhibits the growth of cultured metastatic melanoma cells. Furthermore, growth inhibition correlates with a quantitative increase in hypophosphorylated pRb in the representative sensitive melanoma cell line SK-Mel-110. Although multiple factors influence pRb phosphorylation, it appears that both cyclin D1 and p21 expression do not change in the presence of DHA, although p27 was strikingly increased in SK-Mel-110 cells in the absence of FBS. The fact that pRb became hypophosphorylated after exposure to DHA suggests a cross-talk mechanism between fatty acid metabolism and the pRb pathway. Determining the mechanism by which PUFAs can inhibit melanoma growth will be an important first step in the rational use of PUFAs as antitumor agents.

Photoinduced refractive-index change in Sm(+2)/Sm(+3) codoped aluminosilicate fiber by irradiation of an Ar-ion laser

A Sm(+2)/Sm(+3) codoped aluminosilicate glass optical fiber was fabricated by use of modified chemical-vapor deposition in conjunction with an aerosol-delivery technique. A permanent index change of 7.6 x 10(-5) was induced in the fiber by irradiation of 1 W of multiline output from an Ar-ion laser. Bleaching of a broad absorption band of Sm(+2) in the visible range was also observed, and it is believed that photoionization of Sm(+2)? Sm(+3)+e plays an important role in the induced photorefractivity.

Evidence for a major gene for type II diabetes and linkage analyses with selected candidate genes in Mexican-Americans

We have carried out two independent family studies in low-income Mexican-Americans from San Antonio, Texas. In the first study, probands were ascertained at random without regard to any medical condition (658 examined individuals from 50 families), and in the second study, probands were subjects with type II diabetes identified in a prior epidemiological survey (523 examined individuals from 29 families). Pedigrees ranging in size from 2 to 45 family members (median 11) in the first study and from 2 to 50 family members (median 12) in the second study were examined. Diabetes was diagnosed according to World Health Organization criteria. In both sets of families, segregation analyses revealed support for a major gene with an autosomal dominant mode of inheritance influencing early age of onset of diabetes. Non-Mendelian inheritance was rejected in both data sets. Individuals with the early age of onset allele had a mean age of diabetes onset of 51 years in the first data set and 60 years in the second data set. In the first data set, the major gene accounted for approximately 70% of the phenotypic variance in age of onset of diabetes, and there were no residual family effects once the major gene effect was taken into account. In the second data set, the major gene accounted for approximately 50% of the phenotypic variance, and residual family effects were statistically significant. Linkage analyses were performed with 11 candidate genes, and tight linkage with diabetes was rejected for Rh blood group, glucose transporter 2, fatty acid-binding protein, tumor necrosis factor beta, glucokinase, and lipoprotein lipase. A logarithm of odds (LOD) score of 0.92 at a recombination fraction of 0.05 was observed for insulin receptor substrate 1. This LOD score corresponds to a chi2 of 4.24 (P = 0.039).

The influence of response bias on segregation and linkage analysis

Response bias in epidemiologic studies can occur if affected individuals are more (or less) likely to participate in a survey than their unaffected counterparts. To examine the effect of response bias in the context of a family study, we conducted segregation and linkage analysis in all 1,000 individuals in the Problem 2 data set, and in two different 65% samples: one sample consisting of 648 randomly selected individuals, and the other sample nonrandomly constructed so that individuals with high levels of Q1 were oversampled. In this simulation the ability to detect major genes for Q1-Q4 in segregation analysis and to link these putative major genes to genetic markers in linkage analysis was not markedly different between the 65% random and the 65% enriched samples.

Simple prism-based scheme for fabricating Bragg gratings in optical fibers

A modified prism-based method for fabricating Bragg gratings in optical fibers is introduced. We have made an optical fiber Bragg grating at 799.67 nm by using a 45 degrees right-angle prism and a frequency-doubled argon-ion laser at 244 nm. The advantage of this method is ease of alignment.

Broadband superfluorescent emission of the (3)H(4) ? (3)H(6) transition in a Tm-doped multicomponent silicate fiber

We report the observation of amplified spontaneous emission in the (3)H(4) ? (3)H(6) transition of Tm(+3) in a Ta(2)O(5)-doped multicomponent silicate fiber. The evolutions of the spectral shape, output power, and center wavelength were measured as a function of fiber length and pump power in the previously unstudied high-power range, where saturation effects dominate. An output power of 1 mW has been achieved at 1.91 microm with a bandwidth of 77 nm.

Continuous-wave oscillation of thulium-sensitized holmium-doped silica fiber laser

We have observed oscillation in a Tm(3+) and Ho(3+) codoped silica fiber from the (5)I(7) ? (5)I(8) transition of Ho(3+) in the 2-microm region, by pumping the fiber laser into a Tm(3+) absorption between 800 and 830 nm. By a change in the cavity length, the laser was tunable between 2.037 and 2.096 microm. When the laser was pumped with a Ti:sapphire laser at 820 nm, an absorbed threshold power extracted power of 214mW, a slope efficiency of 4.2%,and maximum extracted power of 12.5 mW were measured.

Mutagenic peroxides in diethyl ether

Concentration of water-saturated commercial samples of diethyl ether by a stream of nitrogen yielded an aqueous residue mutagenic in S. typhimurium strains TA100 and TA102, but not TA1535. Reverse phase high-performance liquid chromatography resolved the mixture into 4 UV absorbing peaks, each of which was positive for peroxide and mutagenic in strain TA100 and TA102. One of these was identified as H2O2 based on HPLC retention time and sensitivity to decomposition by catalase, and another as 1-ethoxyethylhydroperoxide, based on its 1H-NMR spectrum. The mutagenic peroxides appeared to be stable in water between pH 3 and 6, but unstable above pH 7; they were less stable in methanol, acetonitrile, and least stable in chloroform, in which they partially decomposed after 24 h at 20 degrees C. Generalization of the results suggests that adverse effects observed in vitro and in vivo with chemicals containing ether linkages that actually have been caused by contaminant peroxides and reactive oxygen compounds.

Ultraviolet-light photosensitivity in Er(3+)-Ge-doped optical fiber

Light-induced refractive-index change in Er(3+)-Ge-doped optical fiber is reported for the first time to the authors' knowledge. Evidence of the change is observed when UV light (lambda = 249 nm) irradiates one arm of an unbalanced Mach-Zehnder interferometer made from Er(3+)-Ge-doped fiber. From a measurement of the change in the spectral response of the interferometer with UV exposure, the change in fiber core index as a function of wavelength is determined. The equilibrium change in core index is found to vary between 2.3 x 10(-5) and 3.7 x 10(-5) over the measured wavelength region of 800 to 1700 nm. Also for the first time to our knowledge, fused couplers made of Er(3+)-doped fiber are reported. These identical fiber couplers are used in a novel all-fiber unbalanced Mach-Zehnder interferometer.