Environmental factors shaping a sawfly-associated community of parasitoids

A major goal of evolutionary biology is to understand the mechanisms that shape biodiversity, especially amongst highly speciose lineages such as parasitic wasps. However, most of these lineages are poorly described, with very little available natural history information. This lack of information limits our ability to uncover the environmental factors that contribute to their patterns of divergence, distribution, and abundance. To that end, here we take advantage of a community of hymenopteran parasites that has an unusually large amount of available information since they attack an economically important pine sawfly species, Neodiprion lecontei. We build upon a set of historical literature to produce the most comprehensive survey of this parasite community to date and identify several putative new species. For a subset of this community, we then examine how different environmental variables impact community composition, and shape species’ distribution and abundance. Finally, we interpret our results in light of their interactions with their sawfly host

AGE-RELATED CARDIOVASCULAR HEALTH AMONG ELITE ULTRA-ENDURANCE ATHLETES

BACKGROUND: Aging is associated with increased cardiovascular (CV) disease risk which is partly attributable to increased blood pressure (BP) and central arterial stiffness. Regular exercise is recommended to slow CV aging, but it is unclear whether “extreme exercise”, such as ultra-endurance running (\u3e42.2 km), elicits the same CV benefits as lower-volume training. Therefore, the purpose of this investigation was to test the hypothesis that ultra-endurance running preserves CV health across the lifespan. METHODS: We measured supine BP with an automated brachial cuff and arterial stiffness (carotid-to-femoral pulse wave velocity [cfPWV]) with applanation tonometry (SphygmoCor XCEL, AtCor Medical) among 72 athletes (16F/56M; BMI: 22.6 ± 1.8 kg/m2) 1-3 days before they competed in the 161-km Western States Endurance Race (WSER) (Olympic Valley, CA; elevation: 1890 m). We present data as mean ± SD and confirmed normality using Shapiro-Wilk tests (α ≥ 0.05). We used simple linear regression to assess the relationship between age and systolic BP (SBP), diastolic BP (DBP), and cfPWV. We compared individual cfPWV outcomes to available normative data. RESULTS: Among 72 WSER athletes, age (46 ± 10 years; range: 26-69 yrs), SBP (129 ± 9 mmHg), DBP (78 ± 7 mmHg), and cfPWV (n = 70; 6.5 ± 1.0 m/s) were normally distributed (Ws ≥ 0.97, Ps ≥ 0.06). Approximately 60% (43/72) of the athletes presented with hypertension (≥130mmHg SBP and/or \u3e80 mmHg DBP) but age was not associated with SBP (R2 = 0.02, P = 0.23) or DBP (R2 = 0.05, P = 0.06). Age was positively associated with cfPWV (R2 = 0.25, P \u3c 0.001) but 84% (59/70) of participants had cfPWV values below their age-predicted value (mean difference: -0.9 m/s). CONCLUSIONS: Among these WSER athletes, a majority were hypertensive, but there was not a meaningful relationship between age and BP. Moreover, in this sample, the increase in SBP per decade (1.3 mmHg/decade) was much lower compared to previously reported increases among the general population (6.5 mmHg/decade). Despite an age-related increase in cfPWV, 84% of athletes had cfPWV values below their age-predicted value. These findings suggest that ultra-endurance training is associated with preserved CV health across the lifespan via attenuated age-related increases in BP and cfPWV values below age-predicted norms