29 research outputs found
Phenology of Scramble Polygyny in a Wild Population of Chrysolemid Beetles: The Opportunity for and the Strength of Sexual Selection
Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations
Cyanobacterial lipopolysaccharides and human health – a review
Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation
ISOMETRIC MID-THIGH PULL KINETICS PREDICT DRIVER CLUB HEAD SPEED IN COLLEGIATE GOLFERS
Samuel J. Wilson1, Jessica A. Mutchler1, John C. Garner2, Kyle B. Rank3, Jeffrey D. Simpson3. 1Georgia Southern University, Statesboro, GA. 2Troy University, Troy, AL. 3University of West Florida, Pensacola, FL.
BACKGROUND: Within golf, force generation and the relationship to club head speed (CHS) has been frequently investigated. Recently, positive relationships between force generation and CHS during an isometric mid-thigh pull (IMTP) have been reported in golfers that may reflect the force generation capability during the swing. But, contributions from the lead and trail legs and their relationship to CHS are not known. The purpose of this study was two-fold: 1) to determine differences in force generation capability during an IMTP between the lead and trail legs, and 2) identify force generation predictors of CHS from an IMTP test. METHODS: 18 Division II golfers (male=10; female=8; age: 20±1 y; height: 171.4±4.7 cm; mass: 69.7±17.5 kg) completed the study. Participants completed 10 stock swings on a FlightScope Mevo+ in an indoor environment with their driver. On a separate day, 3 trials of a 5 second IMTP was completed on a dual-force platform. Ground reaction force (GRF) data was used to identify peak vertical GRF and RFD at 50, 100, 150, and 200ms during the IMTP trials from both legs. Averages from the 3 IMTP trials and the average of the 5 highest CHS from driver were used in the analysis. A stepwise regression model using backward elimination was computed to identify significant predictors of CHS. Further, dependent variables from the IMTP were also compared between the lead and trail legs using a dependent samples t-test (p\u3c0.05) and the magnitude of differences were evaluated using Cohen’s D effect sizes. RESULTS: Average CHS for driver was 105.5±11.9 mph. The trail leg generated greater peak vertical GRF (p=0.023; ES=0.40), RFD at 150 (p=0.004; ES=0.004), and RFD at 200 (p\u3c0.001; ES=0.039) compared to the lead leg. The stepwise regression model identified 5 variables that were significant predictors of CHS: (1) trail leg RFD at 50ms (p=0.001; r=0.646), (2) lead leg RFD at 50ms (p\u3c0.001; r=0.514), (3) trail leg RFD at 100ms (p=0.014; r=0.650), (4) lead leg RFD at 100ms (p=0.006; r=0.514), and (5) trail leg RFD at 200ms (p\u3c0.001; r=0.739), explaining a combined 88% of the variance in CHS. CONCLUSIONS: Greater peak force and RFD at 150 and 200ms suggests that the lead and trail legs exhibit different force generation capabilities during an IMTP. While the differences between legs could be due to many factors, both lead and trail leg RFD at 50 and 100ms appear to be significant predictors of CHS
Candidate single nucleotide polymorphisms and thromboembolism in acute lymphoblastic leukemia - A NOPHO ALL2008 study
The Association between Asparaginase Enzyme Activity Levels and Toxicities in Childhood Acute Lymphoblastic Leukaemia in the NOPHO ALL2008 Protocol
Asparaginase-Associated Pancreatitis in ALL: Results from the NOPHO ALL2008 Treatment of Patients 1-45 Years
Premature discontinuation of asparaginase reduces cure rate in contemporary acute lymphoblastic leukemia (ALL) treatment. One of the commonest causes of asparaginase truncation is asparaginase-associated pancreatitis (AAP). We prospectively registered AAP during treatment of 2,448 consecutive Nordic/Baltic ALL patients aged 1.0-45.9 years treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol (7/2008-10/2018). The Day 280 cumulative incidence of first-time AAP (including 99% (167/168) of AAP events at this time point) was 8.3% (95% confidence interval (CI) 7.0-9.9) with a median time of 104 days (interquartile range (IQR) 70-145) from ALL diagnosis to AAP, with a median of 10 days (IQR 6-13) from last asparaginase exposure, and after a median number of five asparaginase doses (IQR 3-7, max 14 doses). All patients received polyethylene glycol conjugated Escherichia coli-derived asparaginase as standard treatment. Eighty-five percent (140/164, unknown in N=4) of AAP events were severe (AAP-associated symptoms and/or pancreatic enzymes >3x upper normal limit lasting >72 hours or with hemorrhagic pancreatitis, pancreatic abscess, or pseudocyst). Four age groups were defined: 1.0-4.9, 5.0-8.9, 9.0-16.9, and 17.0-45.9 years-each containing approximately 25% of the AAP events. Compared with patients aged 1.0-4.9 years, adjusted (sex, immunophenotype, and white blood cell count) hazard ratios (HR) of AAP were associated with higher age (5.0-8.9 years: HR 2.3, 95% CI 1.5-3.6, P<.0001; 9.0-16.9 years: HR 2.5, 95% CI 1.6-3.8, P<.0001; and 17.0-45.9 years: HR 2.5, 95% CI 1.6-3.8, P<.0001). When analyzing the odds of developing any AAP-related complication among patients with ≥100 days of follow-up after the AAP diagnosis, older children (≥5.0 years) and adolescents had increased odds of developing any complication compared with younger children aged 1.0-4.9 years, notably a more than six-fold increase among adolescents (5.0-8.9 years: odds ratio (OR) 2.67, 95% CI 1.07-6.68, P=.04 and 9.0-16.9 years: OR 6.52, 95% CI 2.35-18.1, P=.0003)-including acute and permanent insulin need; intensive care unit admission; pancreatic pseudocyst development; recurrent abdominal pain; elevated pancreatic enzymes at last-follow-up; imaging compatible with pancreatitis (pancreatic inflammation/edema/pseudocysts/hemorrhage) at last follow-up; and AAP-related death. Adult age was not associated with development of any AAP-related complication (17.0-45.9 years: OR 2.3, 95% CI 0.9-5.9, P=.07). Three patients aged 8.6, 17.3, and 18.6 years died of first-time AAP within 0-29 days from AAP diagnosis. Of 168 AAP patients, 34 (20%) were re-challenged with asparaginase. Fifty percent (17/34) developed a second episode of AAP-41% being severe (7/17). The median time to a second AAP event from asparaginase re-exposure was 29 days (IQR 16-94) and occurred after a median of two asparaginase doses (range 0-7). Neither age group nor severity of the first AAP was associated with increased hazard of a second AAP event. None of the patients with a second AAP were further re-exposed to asparaginase, and none died of the second AAP. Among a total of 196 ALL relapses, 21 patients have had AAP including 17 patients with asparaginase truncation. However, the hazard of relapse (age- and sex-adjusted) was not increased among AAP patients with asparaginase truncation versus AAP patients with asparaginase re-exposure (5.0-year cumulative incidence of relapse: 13.2% versus 14.2%) (HR 1.0, 95% CI 0.3-3.1, P=1.0). When analyzing time to relapse among AAP patients versus non-AAP patients, no difference in hazard of relapse was found (HR 2.0, 95% CI 0.8-4.9, P=.2). In conclusion, adolescents and young adults tolerated asparaginase treatment as well as children; however, the risk of AAP was higher for patients older than 5.0 years of age with no difference with increasing age. Despite a low AAP-related mortality, the morbidity was considerable and most profound for patients aged 9.0-16.9 years. Since asparaginase re-exposure was associated with a high risk of a second AAP event and neither AAP development nor AAP-related asparaginase truncation was associated with increased relapse risk, asparaginase re-exposure should be attempted only in patients with a high risk of leukemic relapse. Finally, there is an unmet need for preventive strategies toward AA
