Relevance of force-velocity and change of direction assessments for the ranking position in elite junior tennis players

PurposeThis study aimed to correlate sprint mechanical parameters (SMP) of a linear sprint (LS) and a tennis specific modified 505 (Tm505) change of direction (CoD) test obtained with a motorized resistance device (MRD) to the current tennis ranking position (RP).Methods107 male and 86 female elite junior tennis players nationally ranked in the German Tennis Federation between 10 and 18 years participated in the study. According to their age at peak height velocity (PHV), players were divided into pre-PHV, circa-PHV, and post-PHV groups. SMP were derived from instantaneous time-velocity data of two 20 m all-out LS measured with 333 Hz. Further, mean values from two Tm505 trials with constant 3 kg loading over acceleration-deceleration (1a) and reacceleration (1b) phases were measured with an MRD. SMP of LS and CoD measurements were partially correlated with the current RP in the overall national ranking by controlling for biological maturation.ResultsLow to moderate correlations (rs = −0.1 to −0.3) were found between SMP and the RP in all male and female age groups. Correlations of the CoD measurements were overall more pronounced, particularly in girls (rs = −0.44). All linear SMP, like maximal theoretical force (F0; N/kg), and maximal theoretical velocity (v0; m/s), maximal power (Pmax; W/kg), improved over maturation for both genders with Pmax being most important for sprint performance. Further, Pmax was shown to correlate with the girls ranking position (rs = −0.31). During the Tm505, matured players achieved significantly faster overall total and CoD times. Positioning of CoM before CoD enlarged over maturation and was found to correlate to the RP in both sexes. In addition, nearly all SMP significantly correlated to the primary performance outcomes in the Tm505 test in both genders (r = −0.3 to −0.6).ConclusionCoD performance has a moderate and higher impact on tennis performance compared to LS. CoD performance as well as Pmax achieved a higher relevance for the ranking position predominantly in girls compared to boys. Hence, particularly Pmax as well as the transfer to on-court CoD motor skills should be a central training goal in elite junior tennis players besides technical skills and should depend on maturation status and gender

Improving Student Engagement in Veterinary Business Studies

In a densely packed veterinary curriculum, students may find it particularly challenging to engage in the less overtly clinical subjects, yet pressure from industry and an increasingly competitive employment market necessitate improved veterinary student education in business and management skills. We describe a curriculum intervention (formative reflective assignment) that optimizes workplace learning opportunities and aims to provide better student scaffolding for their in-context business learning. Students were asked to analyze a business practice they experienced during a period of extra-mural studies (external work placement). Following return to the college, they were then instructed to discuss their findings in their study group, and produce a group reflection on their learning. To better understand student engagement in this area, we analyzed individual and group components of the assignment. Thematic analysis revealed evidence of various depths of student engagement, and provided indications of the behaviors they used when engaging at different levels. Interactive and social practices (discussing business strategies with veterinary employees and student peers) appeared to facilitate student engagement, assist the perception of relevance of these skills, and encourage integration with other curriculum elements such as communication skills and clinical problem solving

Effect of 5-FU and MTX on the Expression of Drug-resistance Related Cancer Stem Cell Markers in Non-small Cell Lung Cancer Cells

Cancer stem cells (CSCs) are often characterized by the elevated expression of drug-resistance related stem-cell surface markers, such as CD133 and ABCG2. Recently, we reported that CSCs have a high level of expression of the IL-6 receptor (IL-6R). The purpose of this study was to investigate the effect of anticancer drugs on the expression of the drug resistance-related cancer stem cell markers, ABCG2, IL-6R, and CD133 in non-small cell lung cancer (NSCLC) cell lines. A549, H460, and H23 NSCLC cell lines were treated with the anticancer drugs 5-fluorouracil (5-FU; 25 µg/ml) and methotrexate (MTX; 50 µg/ml), and the expression of putative CSC markers was analyzed by fluorescent activated cell sorter (FACS) and the gene expression level of abcg2, il-6r and cd133 by reverse transcriptasepolymerase chain reaction (RT-PCR). We found that the fraction of ABCG2-positive(+) cells was significantly increased by treatment with both 5-FU and MTX in NSCLC cells, and the elevation of abcg2, il-6r and cd133 expressions in response to these drugs was also confirmed using RT-PCR. Also, the number of IL-6R(+) cells was increased by MTX in the 3 cell lines mentioned and increased by 5-FU in the H460 cell line. The number of CD133(+) cells was also significantly increased by both 5-FU and MTX treatment in all of the cell lines tested. These results indicate that 5-FU and MTX considerably enhance the expression of drug-resistance related CSC markers in NSCLC cell lines. Thus, we suggest that antimetabolite cancer drugs, such as 5-FU and MTX, can lead to the propagation of CSCs through altering the expression of CSC markers

Sequential neuromodulation of Hebbian plasticity offers mechanism for effective reward-based navigation

Spike timing-dependent plasticity (STDP) is under neuromodulatory control, which is correlated with distinct behavioral states. Previously we reported that dopamine, a reward signal, broadens the time window for synaptic potentiation and modulates the outcome of hippocampal STDP even when applied after the plasticity induction protocol (Brzosko et al., 2015). Here we demonstrate that sequential neuromodulation of STDP by acetylcholine and dopamine offers an efficacious model of reward-based navigation. Specifically, our experimental data in mouse hippocampal slices show that acetylcholine biases STDP towards synaptic depression, whilst subsequent application of dopamine converts this depression into potentiation. Incorporating this bidirectional neuromodulation-enabled correlational synaptic learning rule into a computational model yields effective navigation towards changing reward locations, as in natural foraging behavior. Thus, temporally sequenced neuromodulation of STDP enables associations to be made between actions and outcomes and also provides a possible mechanism for aligning the time scales of cellular and behavioral learning.Medical Research Council Studentship Zuzanna Brzosko Wolfram Schultz Ole Paulsen Engineering and Physical Sciences Research Council Studentship Sara Zannone Claudia Clopath Wellcome 095495 Wolfram Schultz Biotechnology and Biological Sciences Research Council BB/N013956/1 Claudia Clopath Wellcome 200790/Z/16/Z Claudia Clopath Biotechnology and Biological Sciences Research Council BB/N019008/1 Ole Paulse

Factors associated with herbal use among urban multiethnic primary care patients: a cross-sectional survey

BACKGROUND: The use of herbal supplements in the United States has become increasingly popular. The prevalence of herbal use among primary care patients varies in previous studies; the pattern of herbal use among urban racially/ethnically diverse primary care patients has not been widely studied. The primary objectives of this study were to describe the use of herbs by ethnically diverse primary care patients in a large metropolitan area and to examine factors associated with such use. The secondary objective was to investigate perceptions about and patterns of herbal use. METHODS: Data for a cross-sectional survey were collected at primary care practices affiliated with the Southern Primary-care Urban Research Network (SPUR-Net) in Houston, Texas, from September 2002 to March 2003. To participate in the study, patients had to be at least 18 years of age and visiting one of the SPUR-Net clinics for routine, nonacute care. Survey questions were available in both English and Spanish. RESULTS: A total of 322 patients who had complete information on race/ethnicity were included in the analysis. Overall, 36% of the surveyed patients (n = 322) indicated use of herbs, with wide variability among ethnic groups: 50% of Hispanics, 50% of Asians, 41% of Whites, and 22% of African-Americans. Significant factors associated with an individual's herbal use were ethnicity other than African-American, having an immigrant family history, and reporting herbal use by other family members. About 40% of survey respondents believed that taking prescription medications and herbal medicines together was more effective than taking either alone. One-third of herbal users reported using herbs on a daily basis. More Whites (67%) disclosed their herbal use to their health-care providers than did African-Americans (45%), Hispanics (31%), or Asians (31%). CONCLUSIONS: Racial/ethnic differences in herbal use were apparent among this sample of urban multiethnic adult primary care patients. Associated factors of herbal use were non-African-American ethnicity, immigrant family history, and herbal use among family members. Whereas Hispanics and Asians reported the highest rates of herbal use, they were the least likely to disclose their use to health-care professionals. These findings are important for ensuring medication safety in primary care practices