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We identify beneficial associations between cardiorespiratory fitness and lower carotid stiffness and pulse pressure as potential mechanisms underlying sex-specific associations of fitness and cerebral pulsatility in females without modifiable risk factors. Greater fitness is beneficially associated with conductance, pulsatile damping, and forward wave energy among adults without risk factors; however, associations are attenuated among adults with modifiable risk factors. These data suggest sex and risk factors may alter cerebrovascular sensitivity to cardiorespiratory fitness.

There are well-established sex differences in central hemodynamic and cardiac adaptations to endurance exercise; however, controversial evidence suggests that excessive endurance exercise may be related to detrimental cardiovascular adaptations in marathoners. To examine left ventricle (LV) structure, LV function, 24-h central hemodynamics and ventricular–vascular coupling in male and female marathoners and recreationally active adults. 52 marathoners (41 ± 5 years, n = 28 female, completed 6 ± 1 marathons/3 years) and 49 recreationally active controls (42 ± 5 years, n = 25 female) participated in the study. Three-Dimensional Echocardiography (3DE) was used to measure LV mass index and LV longitudinal (LS) circumferential (CS), area (AS), and radial strain (RS). An ambulatory blood pressure (BP) cuff was used to measure 24-h central hemodynamics (BP, pulse wave velocity, PWV, wave reflection index, RIx). Hemodynamic and 3DE measures were combined to derive the ratio of arterial elastance (Ea) to ventricular elastance (Elv) as a global measure of ventricular–vascular coupling. There were no sex or group differences in LS, CS, AS, and RS (p > 0.05). Females marathoners had similar aortic BP (116 ± 9 vs. 113 ± 1 mmHg), and PWV (5.9 ± 0.5 vs. 5.9 ± 1.1 m/s) compared to female controls but lower aSBP (116 ± 9 vs. 131 ± 10 mmHg) and PWV (5.9 ± 0.5 vs. 6.2 ± 0.5 m/s) compared to male marathoners (p

Cerebral pulsatility reflects a balance between the transmission and damping of pulsatility in the cerebrovasculature. Females experience greater cerebral pulsatility with aging, which may have implications for sex differences in stroke risk and cognitive decline. This study sought to explore vascular contributors to cerebral pulsatility and pulsatile damping in men and women. Adults (n = 282, 53% female) underwent measurements of cerebral (middle cerebral artery) pulsatility, pulsatile damping (ratio of cerebral to carotid pulsatility), large artery stiffening (ratio of aortic to carotid pulse wave velocity), and carotid wave transmission/reflection dynamics using wave intensity analysis. Multiple regression revealed that older age, female sex, greater large artery stiffening, higher carotid pulse pressure, and greater forward wave energy was associated with increased cerebral pulsatility (adjusted R2 = 0.44, P < 0.05). Contributors to decreased cerebral pulsatile damping included older age, female sex, and lower wave reflection index (adjusted R2 = 0.51, P < 0.05). Our data link greater large artery stiffening, carotid pulse pressure, and forward wave energy to greater cerebral pulsatility, while greater carotid wave reflection may enhance cerebral pulsatile damping. Lower cerebral pulsatile damping among females may contribute to greater age-associated cerebral pulsatile burden compared with males. NEW & NOTEWORTHY Cerebral pulsatility contributes to brain health and depends on a balance between transmission and damping of pulsatile hemodynamics into the cerebrovasculature. Our data indicate that cerebral pulsatility increases with age, female sex, extracranial artery stiffening, forward wave energy, and pulse pressure, whereas pulsatile damping decreases with age and female sex and increases with greater carotid wave reflections. These novel data identify pulsatile damping as a potential contributor to sex differences in cerebral pulsatile burden.

Context: A variety of gait retraining interventions are available to modify running mechanics associated with musculoskeletal injuries. These often require specialized equipment and/or personnel to prompt the runner toward specific strategies. Objective: To determine whether instructing female recreational runners to “run quietly” could decrease impact force characteristics. Design: Cohort. Setting: Research laboratory. Participants: Fifteen healthy female recreational runners (24 [7] y) volunteered. Interventions: Baseline testing occurred on day 1 (baseline), a posttraining assessment occurred on day 2 (training), and a final assessment occurred 1 week after training on day 3 (follow-up). A smartphone decibel measuring app was used to provide biofeedback on the decibel level of foot strike on day 2 (training). Main Outcomes: Peak vertical force, impact transient, peak and average vertical loading rate, ground contact time, and running economy were collected on each day and compared via repeated-measures analyses of variance. Results: Vertical ground reaction force was lower at follow-up (2.30 bodyweights [BW]) versus baseline (2.39 BW, P = .023) and training (2.34 BW, P = .047). Maximal loading rate decreased from baseline (69.70 BW·s−1) to training (62.24 BW·s−1, P = .021) and follow-up (60.35 BW·s−1, P = .031). There was no change in running economy. Conclusions: Our findings demonstrate that simple instructions to “run quietly” can yield immediate and sustained reductions in impact force profiles, which do not influence running economy.

Color‐based visual signals are important aspects of communication throughout the animal kingdom. Individuals evaluate color to obtain information about age and condition and to behave accordingly. Birds display a variety of striking, conspicuous colors and make ideal subjects for the study of color signaling. While most studies of avian color focus on plumage, bare unfeathered body parts also display a wide range of color signals. Mate choice and intrasexual competitive interactions are easily observed in lekking grouse, which also signal with prominent unfeathered color patches. Most male grouse have one pair of colorful bare part ornaments (combs), and males of several species also have inflatable air sacs in their throat. Previous studies have mostly focused on comb color and size, but little is known about the signaling role of air sac color. We measured comb size and the color properties of combs and air sacs in the Lesser and Greater Prairie‐Chickens (Tympanuchus pallidicinctus and T. cupido, respectively), and investigated whether these properties varied with age and mass. We found that mass predicted color properties of air sacs and that age predicted comb size in the Greater Prairie‐Chicken, suggesting that these ornaments indicate condition dependence. No conclusive relationships between color and age or size were detected in the Lesser Prairie‐Chicken. Color properties of both ornaments differed between the two species. Further research is needed to determine mechanisms that link condition to color and whether the information advertised by color signals from these ornaments is intended for males, females, or both., We measured comb size and the color properties of combs and air sacs in wild caught Lesser and Greater Prairie‐Chickens (Tympanuchus pallidicinctus and T. cupido, respectively), and investigated whether these properties varied with age and mass. We found that mass predicted color properties of air sacs and that age predicted comb size in the Greater Prairie‐Chicken, but no conclusive relationships between ornament color and age or size were detected in the Lesser Prairie‐Chicken. Our findings suggest the occurrence of a past episode of character displacement, possibly as a means of discouraging hybridization, between these recently diverged congeneric species.

There are well-established sex differences in central hemodynamic and cardiac adaptations to endurance exercise; however, controversial evidence suggests that excessive endurance exercise may be related to detrimental cardiovascular adaptations in marathoners.To examine left ventricle (LV) structure, LV function, 24-h central hemodynamics and ventricular-vascular coupling in male and female marathoners and recreationally active adults.52 marathoners (41 ± 5 years, n = 28 female, completed 6 ± 1 marathons/3 years) and 49 recreationally active controls (42 ± 5 years, n = 25 female) participated in the study. Three-Dimensional Echocardiography (3DE) was used to measure LV mass index and LV longitudinal (LS) circumferential (CS), area (AS), and radial strain (RS). An ambulatory blood pressure (BP) cuff was used to measure 24-h central hemodynamics (BP, pulse wave velocity, PWV, wave reflection index, RIx). Hemodynamic and 3DE measures were combined to derive the ratio of arterial elastance (Ea) to ventricular elastance (Elv) as a global measure of ventricular-vascular coupling.There were no sex or group differences in LS, CS, AS, and RS (p 0.05). Females marathoners had similar aortic BP (116 ± 9 vs. 113 ± 1 mmHg), and PWV (5.9 ± 0.5 vs. 5.9 ± 1.1 m/s) compared to female controls but lower aSBP (116 ± 9 vs. 131 ± 10 mmHg) and PWV (5.9 ± 0.5 vs. 6.2 ± 0.5 m/s) compared to male marathoners (p 0.05). Female marathoners had lower Ea/Elv than female controls (0.67 ± 0.20 vs. 0.93 ± 0.36) and male marathoners (0.67 ± 0.20 vs. 0.85 ± 0.42, p 0.05).Women that have completed multiple marathons do not have reduced LV function or increased aortic stiffness and may have better ventricular-vascular coupling compared to male marathoners and their female untrained counterparts.

Sexual selection theory maintains that traits under selection honestly advertise qualities of signaling individuals and that only individuals in the best condition can survive while displaying maximally elaborated secondary sexual ornaments. Recent trends in mate choice studies have favored the consideration of the effects of multiple traits on mating success, including suites of traits transmitted in different sensory modalities. Sexual selection is expected to be especially strong in lek-mating species. The lesser prairie-chicken (Tympanuchus pallidicinctus) is a grouse species which breeds on leks. Males of this species perform audio and locomotor displays and exhibit two pairs of brightly colored ornaments. We performed an observational study of mate choice in spring 2016–2018 and noted 40 copulations on seven leks. We quantified behavioral, territorial, and morphological characteristics of males along with ornament color properties. We found that variables from all categories considered predicted female choice. Age had the strongest effect, with adult males experiencing higher female choice relative to yearlings. Allocation of aggressive behavior and comb color properties were also strongly correlated with female choice. Our results show that modulating behavior depending on whether females are present contributes to male mating success and highlight the importance of the size and color properties of secondary ornaments. Further research is required to determine how the variables most strongly associated with mate choice relate to one another and which aspects of individual quality, if any, are signaled by color ornaments. Future studies could also incorporate variables related to females to determine if selection on females occurs. The choice of a mate can help determine the survival and reproductive success of offspring. In species where males do not care for offspring, mate choice can be highly consistent among females, and mate choice decisions are often based on the evaluation of multiple traits such as vocalizations, behavior, and morphological trait size. Based on measurements of captured males and observations of breeding behavior, we demonstrate that mate choice in lesser prairie-chickens (Tympanuchus pallidicinctus) correlates with male behavior, morphology, skin patch color, and territorial characteristics. Our findings represent a rare demonstration of mating success being influenced by how male behavior (including aggression) changes when females are present or absent. Our results show how multiple traits can transmit information about individual quality and support theoretical links between mate choice and increased male age or male-male competition.

Cerebral pulsatility is an emerging contributor to brain health that reflects the balance between the transmission and damping (i.e. attenuation) of pulsatility through extracranial vessels into the cerebrovasculature. Identifying biological (age, sex) and vascular contributors to pulsatile balance may provide insight into sex differences in brain aging. Purpose: Explore biological and vascular contributors to cerebral pulsatility and pulsatile damping. Methods: 282 Adults (53% female) 18–85 yrs underwent measurements of cerebral (middle cerebral artery) pulsatility, pulsatile damping (cerebral:carotid pulsatility), large artery stiffening (aortic:carotid pulse wave velocity (PWV)), and carotid wave transmission/reflection dynamics using wave-intensity analysis. Multiple regression was used to examine the contributions of 1) age, sex, BMI, aortic:carotid PWV, carotid diameter, pulse pressure, and forward-wave energy to cerebral pulsatility; and 2) age, sex, BMI, aortic:carotid PWV, carotid diameter, wave reflection index, and suction-wave energy to pulsatile damping. Results: Age and female sex were predictors of greater cerebral pulsatility and reduced pulsatile damping. Beyond the effects of age and sex, greater large artery stiffening (β = 0.21), pulse pressure (β = 0.28), and forward wave energy (β = 0.26, model R2 = 0.42, p < 0.05) predicted greater cerebral pulsatility, while greater carotid wave reflection index (β = 0.23, model R2 = 0.49, p < 0.05) predicted greater pulsatile damping. Conclusion: Our data confirms literature linking age and extracranial artery stiffening and hemodynamics to cerebral pulsatility. Our findings suggest age and female sex are associated with reduced damping of pulsatile hemodynamics, while carotid wave reflections enhance pulsatile damping. Lower pulsatile damping among females may contribute to greater cerebral pulsatile burden compared to males.

This study examined central artery stiffness and hemodynamic pulsatility during cognitive engagement in younger and older adults.Vascular-hemodynamic measures were completed in 19 younger (age 35±1yrs) and 20 older (age 69±2yrs) adults at rest and during a Stroop task. Aortic stiffness (carotid-femoral pulse wave velocity, PWV) and carotid pulse pressure (PP) were assessed using applanation tonometry. Carotid stiffness was assessed as a single-point PWV using Doppler Ultrasound. Middle cerebral artery (MCA) mean flow and flow pulsatility index (PI) were assessed using transcranial Doppler. Cognitive function was assessed as accuracy and reaction time from the Stroop task.Older adults had lower accuracy scores and longer reaction times on the Stroop task compared to younger adults (p0.05). Both age groups had similar increases in MCA mean flow during Stroop (p0.05). There were significant increases in aortic PWV, carotid PWV, carotid PP and MCA PI during Stroop in older but not younger adults (p0.05). Carotid PP and MCA PI assessed during Stroop were statistical mediators of the association between age group and Stroop performance metrics (accuracy and reaction time, p0.05), while aortic and carotid PWV were indirect statistical mediators of MCA PI through carotid PP (p0.05).Older adults experience increases in large artery stiffness during cognitive engagement possibly preventing effective buffering of pulsatile hemodynamic energy entry into the cerebrovasculature. This is important as pulsatile flow during cognitive engagement, and not mean flow per se, was related to overall cognitive performance.

To investigate racial differences in central blood pressure and vascular structure/function as subclinical markers of atherosclerotic cardiovascular disease in children.This cross-sectional study recruited 54 African American children (18 female, 36 male; age 10.5 ± 0.9 years) and 54 white children (27 female, 26 male; age 10.8 ± 0.9 years) from the Syracuse City community as part of the Environmental Exposures and Child Health Outcomes study. Participants underwent blood lipid and vascular testing on 2 separate days. Carotid artery intima-media thickness and aortic stiffness were measured by ultrasonography and carotid-femoral pulse wave velocity, respectively. Blood pressure was assessed at the brachial artery and estimated in the carotid artery using applanation tonometry.African American children had significantly higher pulse wave velocity (4.8 ± 0.8 m/s) compared with white children (4.2 ± 0.7 m/s; P .05), which remained significant after adjustment for confounding variables including socioeconomic status. African American children had significantly higher intima-media thickness (African American 0.41 ± 0.06, white 0.39 ± 0.05 mm), and carotid systolic blood pressure (African American 106 ± 11, white 102 ± 8 mm Hg; P .05) compared with white children, although these racial differences were no longer present after covariate adjustments for height.Racial differences in aortic stiffness are present in childhood. Our findings suggest that racial differences in subclinical cardiovascular disease occur earlier than previously recognized.

To examine the association between cardiorespiratory fitness and aortic stiffness in women with central obesity. The secondary purpose was to examine whether traditional and nontraditional cardiovascular risk factors mediate the relationship between cardiorespiratory fitness and aortic stiffness.Eighty-seven centrally obese women (age, 42 ± 9 years, [body mass index (BMI)] 28 ± 3 kg/m(2)) participated in this cross-sectional study. Central obesity was defined as a waist circumference85 cm. Pulse wave velocity (PWV) was obtained from the carotid and femoral pulse sites using applanation tonometry to measure aortic stiffness. Maximal aerobic capacity (VO2 Max) was estimated using a submaximal walk test and taken as a measure of cardiorespiratory fitness. Potential correlates of both cardiorespiratory fitness and aortic stiffness examined in this study included the following: triglycerides (TG), C-reactive protein (CRP), homeostasis model assessment of insulin resistance index (HOMA-IR), and pulsatile load (i.e., heart rate × aortic pulse pressure [aPP]).Pearson's bivariate correlations indicated that estimated VO2 Max was inversely associated with PWV (r = -0.330, p 0.05). Using hierarchical multiple regression, the association between estimated VO2 Max and PWV was no longer significant after controlling for traditional and nontraditional cardiovascular risk factors, age, BMI, TG, CRP, HOMA-IR, and pulsatile load (β = 0.121, p 0.05).In centrally obese women, cardiorespiratory fitness was inversely associated with aortic stiffness. Associations were not independent of traditional and nontraditional cardiovascular disease (CVD) risk factors. This suggests that higher levels of cardiorespiratory fitness may indirectly reduce aortic stiffness through its beneficial effects on traditional and nontraditional CVD risk factors in women with central obesity.

Purpose In premenopausal women, amenorrhea contributes to endothelial dysfunction. It is unknown whether this vascular functional change is associated with vascular structural change. Methods This study examined regional and systemic vascular structure and function to gain insight into subclinical atherosclerotic risk in 10 amenorrheic athletes, 18 eumenorrheic athletes, and 15 recreationally active controls. Brachial flow-mediated dilation (FMD) and low flow mediated constriction (L-FMC) were used to measure global endothelial function. Carotid-femoral pulse wave velocity (PWV) was used to measure aortic stiffness. Doppler-ultrasound of the superficial femoral artery (SFA) was used to assess intima-media thickness (IMT) and vessel diameter as indicators of vascular remodeling. Results Amenorrheic athletes had significantly lower brachial FMD adjusted for shear stimulus (6.9 ± 1.3%) compared with eumenorrheic athletes (11.0 ± 1.0%) and controls (11.0 ± 1.1%, p = 0.05 ). Brachial L-FMC (−1.8 ± 4.3%) and aortic PWV (5.0 ± 1.0 m/s) of amenorrheic athletes were similar to those of eumenorrheic athletes (L-FMC, −1.6 ± 4.6%; PWV, 4.6 ± 0.5 m/s) and controls (L-FMC, −1.5 ± 2.8%, p = 0.98 ; PWV, 5.4 ± 0.7 m/s, p = 0.15 ). SFA diameters were similar in amenorrheic athletes (5.7 ± 0.7 mm) and eumenorrheic athletes (5.7 ± 0.7 mm), but amenorrheic athletes had larger SFA diameters compared with controls (5.1 ± 0.6 mm, p = 0.04 ). In amenorrheic athletes, SFA IMT (0.31 ± 0.03 mm) was similar to that of eumenorrheic athletes (0.35 ± 0.07 mm) but significantly thinner compared to that of controls (0.38 ± 0.06, p = 0.01 ). Conclusion Vascular dysfunction in female amenorrheic athletes is not systemic. Parenthetically, amenorrhea may not prevent favorable peripheral vascular structural adaptations to habitual exercise training.

ANCHORS A-WHEY was a 12-week randomized controlled trial (RCT) designed to examine the effect of whey protein on large artery stiffness, cerebrovascular responses to cognitive activity and cognitive function in older adults. Methods: 99 older adults (mean &plusmn, SD, age 67 &plusmn, 6 years, BMI 27.2 &plusmn, 4.7kg/m2, 45% female) were randomly assigned to 50g/daily of whey protein isolate (WPI) or an iso-caloric carbohydrate (CHO) control for 12 weeks (NCT01956994). Aortic stiffness was determined as carotid-femoral pulse wave velocity (cfPWV). Aortic hemodynamic load was assessed as the product of aortic systolic blood pressure and heart rate (Ao SBP &times, HR). Cerebrovascular response to cognitive activity was assessed as change in middle-cerebral artery (MCA) blood velocity pulsatility index (PI) during a cognitive perturbation (Stroop task). Cognitive function was assessed using a computerized neurocognitive battery. Results: cfPWV increased slightly in CHO and significantly decreased in WPI (p &lt, 0.05). Ao SBP &times, HR was unaltered in CHO but decreased significantly in WPI (p &lt, 0.05). Although emotion recognition selectively improved with WPI (p &lt, 0.05), WPI had no effect on other domains of cognitive function or MCA PI response to cognitive activity (p &gt, 0.05 for all). Conclusions: Compared to CHO, WPI supplementation results in favorable reductions in aortic stiffness and aortic hemodynamic load with limited effects on cognitive function and cerebrovascular function in community-dwelling older adults.

The matching of vascular supply to neuronal metabolic demand during cognitive engagement is known as neurovascular coupling (NVC). Arterial stiffness is a prominent determinant of pulsatility in the systemic circulation and may thus indirectly impact NVC. In this pilot investigation, we explored changes in carotid artery stiffness and cerebrovascular hemodynamic pulsatiltiy during cognitive engagement in healthy adults.Twenty-seven adults (age 39 ± 3 years, BMI 24 ± 1 kg/m(2)) underwent Doppler ultrasonography of the common carotid artery (CCA) combined with applanation tonometry to derive (i) CCA elastic modulus (Ep) and β-stiffness index; (ii) CCA flow pulsatility index (PI); (iii) CCA pulse pressure, (iv) CCA augmentation index (AIx). Cerebral PI was assessed using transcranial Doppler at the middle cerebral artery (MCA). All measures were made at rest and during an incongruent Stroop task.CCA PI was reduced (1.75 ± 0.06 to 1.57 ± 0.06, P0.05) while MCA PI was unchanged (0.75 ± 0.02 to 0.75 ± 0.02, P0.05) during Stroop. Brachial pulse pressure increased during Stroop (43 ± 1 to 46 ± 1 mm Hg, P0.05) while CCA pulse pressure was unchanged (36 ± 1 to 35 ± 1 mm Hg, P0.05). Similarly, CCA Ep (54.5 ± 5.5 to 53.8 ± 4.9 kPa, P0.05) and β-stiffness index (4.4 ± 0.4 to 4.2 ± 0.3 aU, P0.05) were unchanged. CCA AIx increased (1 ± 4 to 13 ± 4%, P0.05).Carotid pressure pulsatility is unaltered while carotid flow pulsatility is reduced during cognitive engagement. Carotid artery stiffness does not change suggesting that factors other than the dynamic elastic properties of the CCA buffer cerebrovascular hemodynamic pulsatility during cognitive engagement.

Aerobic exercise has a favorable effect on systemic vascular function, reducing both central (large elastic artery) and peripheral (smaller muscular artery) stiffness. The effects of resistance exercise (RE) on arterial stiffness are more complex. Acute RE increases central artery stiffness while decreasing peripheral stiffness. To date, the majority of studies have been performed in predominantly male participants. To examine the effect of acute RE on central and peripheral arterial stiffnesses in women, a secondary purpose was to explore the influence of cyclic changes in estrogen status across the menstrual cycle on the arterial response to acute RE. 18 healthy women [28 ± 7 years, body mass index (BMI) 22.6 ± 2.9 kg/m2] completed an acute RE bout during the early follicular and the early luteal phase of their menstrual cycle. Salivary 17β-Estradiol concentration was measured during each phase, using a passive drool technique. Pulse-wave velocity (PWV) was obtained from the carotid–femoral and carotid–radial pulse sites to measure central and peripheral stiffness, respectively, using applanation tonometry. PWV was measured at rest, immediately, 10, 20, and 30 min post-RE. 17β-Estradiol concentration was significantly lower in the early follicular vs. the early luteal phase of the menstrual cycle (1.78 ± 0.51 vs. 2.40 ± 0.26 pg/ml, p = 0.01). Central PWV significantly increased (p 0.05). Women experience increases in central arterial stiffness and reductions in peripheral arterial stiffness following acute RE. Menstrual cycle phase may not influence changes in arterial stiffness in response to acute RE.

When ecological or behavioral species-isolating mechanisms are relaxed or incomplete, hybrid zones form. Greater prairie-chickens (Tympanuchus cupido) hybridize with sharp-tailed grouse (T. phasianellus) wherever their ranges overlap. The objective of this study was to document the potential for reproductive isolation between greater prairie-chickens and sharp-tailed grouse in west-central Minnesota, a newly established sympatric and hybridizing population which developed following the translocation of greater prairie-chickens to the area. We describe and evaluate several potential mechanisms of behavioral isolation (intensity of display and aggressive behaviors, and vocal and non-vocal sounds). In addition, we monitored copulation success to determine the patterns of interspecific mating. Individuals of putative mixed genetic makeup (based on morphology) comprised 8 % of the population, a rate higher than previously reported for most areas of the hybrid zone between these two species. Apparent hybrid individuals stomped their feet faster than parental species during courtship displays, and their vocalizations were intermediate between the parental species. Intensity of display and aggressive behaviors were similar for parental species and hybrids. All copulations observed involved conspecific pairs; hybrid males were not observed to mate. Taken together, this study documents behaviors that might reinforce reproductive isolation (foot stomping and vocalization) and other behaviors that are similar among the parental species and hybrids that would hinder reproductive isolation (display and aggressive behaviors). We suggest that the small population sizes of both greater prairie-chickens and sharp-tailed grouse in this newly established population contribute to the higher rate of hybridization than is observed elsewhere in this hybrid zone.

Vocal signaling can be an important component of vertebrate communication during social interactions. If vocalizations vary among individuals but are consistent within a given individual, they may be used to discriminate among individuals. In many species, territorial males use vocalizations to discriminate between neighbors and strangers and either respond more aggressively toward strangers relative to neighbors (“dear enemy” effect) or they respond more aggressively toward neighbors relative to strangers (“nasty neighbor” effect). In the greater prairie-chicken (Tympanuchus cupido), male vocalizations are an integral part of the display males produce on leks. We investigated whether male greater prairie-chickens discriminate among familiar individuals on their own territory, familiar individuals outside their normal territory and strangers from a nearby lek. Vocal characteristics varied among males, suggesting that vocalizations may potentially be used by prairie-chickens to identify individuals. Males responded to playback of prairie-chicken calls by vocalizing at a faster rate and approaching the playback speaker, but did not vary in their response to the vocalizations based on the identity of the caller. Our results suggest that variation is present among the vocalizations of individual male greater prairie-chickens, but males do not appear to discriminate among familiar individuals and strangers based solely on their “boom” vocalizations. Greater prairie-chicken vocalization likely functions as a way of announcing that a territory is occupied and defended, but it may also serve as a way of advertising to conspecifics or as a signal that is secondary to other forms of communication.

Arterial stiffness is associated with cerebral flow pulsatility. Arterial stiffness increases following acute resistance exercise (RE). Whether this acute RE-induced vascular stiffening affects cerebral pulsatility remains unknown. Purpose: To investigate the effects of acute RE on common carotid artery (CCA) stiffness and cerebral blood flow velocity (CBFv) pulsatility. Methods: Eighteen healthy men (22 ± 1 yr; 23.7 ± 0.5 kg∙m-2) underwent acute RE (5 sets, 5-RM bench press, 5 sets 10-RM bicep curls with 90 s rest intervals) or a time control condition (seated rest) in a randomized order. CCA stiffness (β-stiffness, Elastic Modulus (Ep)) and hemodynamics (pulsatility index, forward wave intensity and reflected wave intensity) were assessed using a combination of Doppler ultrasound, wave intensity analysis and applanation tonometry at baseline and 3 times post-RE. CBFv pulsatility index was measured with transcranial Doppler at the middle cerebral artery (MCA). Results: CCA β-stiffness, Ep and CCA pulse pressure significantly increased post-RE and remained elevated throughout post-testing (p < 0.05). No changes in MCA or CCA pulsatility index were observed (p > 0.05). There were significant increases in forward wave intensity post-RE (p< 0.05) but not reflected wave intensity (p>0.05). Conclusion: Although acute RE increases CCA stiffness and pressure pulsatility, it may not affect CCA or MCA flow pulsatility. Increases in pressure pulsatility may be due to increased forward wave intensity and not pressure from wave reflections.

Background. The contour of the common carotid artery (CCA) blood flow velocity waveform changes with age; CCA flow velocity increases during late systole, and this may contribute to cerebrovascular disease. Late systolic flow velocity augmentation can be quantified using the flow augmentation index (FAIx). We examined hemodynamic correlates of FAIx to gain insight into determinants of CCA flow patterns. Methods. CCA Doppler ultrasound and wave intensity analysis (WIA) were used to assess regional hemodynamics in 18 young healthy men (age 22 ± 1 years). Forward waves (W 1) and backward waves (negative area, NA) were measured and used to calculate the reflection index (NA/W 1 = RIx). Additional parameters included W 2 which is a forward travelling expansion/decompression wave of myocardial origin that produces suction, CCA single-point pulse wave velocity (PWV) as a measure of arterial stiffness, and CCA pressure augmentation index (AIx). Results. Primary correlates of FAIx included W 2 (r = − 0.52, P < 0.05), logRIx (r = 0.56, P < 0.05), and AIx (r = 0.60, P < 0.05). FAIx was not associated with CCA stiffness (P > 0.05). Conclusions. FAIx is a complex ventricular-vascular coupling parameter that is associated with both increased expansion wave magnitude (increased suction from the left ventricle) and increased pressure from wave reflections.

Populations of Greater Prairie-Chickens (Tympanuchus cupido) have been declining because of loss and fragmentation of tallgrass prairie habitats, and management plans require contemporary demographic data. Our objectives were to determine whether maternal nutrition or predation were determinants of nesting success and female survival. We captured and radio-marked 43 females at four leks in natural, unfragmented prairie during a 4-year study. Reproductive potential was high because females laid large clutches (10.9 ± 0.3 eggs, n = 24), renested following clutch loss (22.2%, n = 27 females), and had high egg viability (88.6 ± 5.0% of eggs hatched; n = 7 nests), but reproductive traits were not correlated with female morphometrics (mass, or tarsus and keel lengths). Daily survival rate of nests was low (0.928, n = 34 nests) resulting in a predicted nest success rate of 7.4% for a 35-day exposure period. We used known fate models to estimate weekly survival from telemetry data for 40 females. Weekly survival was 0.970 and the extrapolated survival rate for the 6-month breeding season was 45.7%. Using time-sincemarking Cormack-Jolly-Seber models for live encounter data to control for transience, annual apparent survival was 0.277 ± 0.081 SE for 55 marked females after initial capture, and 0.424 ± 0.139 during subsequent intervals. Survival of females was 1.6 to 2.0 times higher during the nonbreeding season than the breeding season, presumably because females are susceptible to predation during incubation and broodrearing. Predation of nests and females may be the main demographic factors limiting population viability because predation, and not maternal nutrition, accounted for unexpectedly low nesting success and breeding season survival of Greater Prairie-Chickens in natural habitats. Future research should investigate rangeland practices that increase residual nesting cover or reduce predator impacts. RESUME. Les populations de Tetras des prairies (Tympanuchus cupido) sont en declin en raison de la perte et de la fragmentation des milieux de prairie a grandes graminees. Les plans de gestion doivent donc s’appuyer sur des donnees demographiques contemporaines. L’objectif de cette etude etait de determiner si l’alimentation des femelles et la predation sont des facteurs importants du succes de reproduction et de la survie des femelles. Nous avons capture et muni de radios 43 femelles provenant de quatre arenes dans des prairies naturelles non fragmentees, au cours d’une etude de quatre ans. Le potentiel de reproduction etait eleve etant donne que les femelles produisaient de grosses couvees (10,9 ± 0,3 œufs, n = 24), qu’elles pouvaient renicher lorsque la premiere avait echoue (22,2 %, n = 27 femelles) et que la viabilite des œufs etait elevee (88,6 ± 5,0 % d’œufs eclos; n = 7 nids), mais ces parametres de reproduction n’etaient pas correles avec les mesures morphometriques des femelles (masse, longueur du tarse et du brechet). Le faible taux de survie quotidien des nids (0,928, n = 34 nids) s’est traduit en un taux de succes de nidification prevu de 7,4 % pour une periode d’exposition de 35 jours. Nous avons utilise des modeles fondes sur le destin connu des individus afin de determiner le taux de survie hebdomadaire a partir de donnees The Ohio State University at Lima, Kansas State University Avian Conservation and Ecology 6(1): 2 http://www.ace-eco.org/vol6/iss1/art2/ telemetriques provenant de 40 femelles. Le taux de survie hebdomadaire etait de 0,970 et le taux de survie extrapole pour l’ensemble des six mois de la saison de reproduction etait de 45,7 %. A l’aide de modeles de Cormack-Jolly-Seber (temps depuis le marquage) applicables aux donnees de recapture pour tenir compte des individus en transit, le taux annuel de survie apparente de 55 femelles s’elevait a 0,277 ± 0,081 (erreurtype) apres leur capture initiale, et a 0,424 ± 0,139 pour les intervalles subsequents. Le taux de survie des femelles en dehors de la saison de reproduction etait de 1,6 a 2 fois plus eleve que celui durant la saison de reproduction, probablement parce que les femelles sont davantage exposees a la predation durant l’incubation et la periode d’elevage des jeunes. La predation des nids et des femelles represente peut-etre le principal facteur demographique qui limite la viabilite des populations etant donne que la predation – et non l’alimentation des femelles – etait responsable du faible succes de reproduction et du faible taux de survie durant la reproduction des Tetras des prairies en milieu naturel. De futures recherches devraient examiner les pratiques d’amenagement des prairies qui permettent d’augmenter le couvert de nidification residuel ou de reduire la predation.

The primary prevention of cardiovascular (CV) disease is hindered by the inadequacy of traditional risk factors to stratify CV risk. The presence of cardiac target organ damage (cTOD), as detected by measures of left ventricular (LV) hypertrophy and dysfunction, is associated with future CV outcomes, but is not currently assessed in asymptomatic individuals. Arterial stiffness contributes to cTOD and may represent a biomarker that can detect vascular dysfunction before the clinical manifestations of cTOD. Measurement of arterial stiffness may provide insight into premature risk for cTOD and afford opportunity for early intervention to prevent further damage. The purpose of this review is to examine the utility of arterial stiffness as a noninvasive biomarker of subclinical cTOD. To this end, we will examine the evidence sup- porting the association between arterial stiffness and measures of cTOD. We will then explore the developmental origins of arterial stiffness and cTOD and outline the progression of CV damage that occurs with age. We discuss the mechanistic role of pressure from wave reflections as a crucial link between arterial stiffness and cTOD. Finally, we examine these associations in context by exploring sex and racial differences in arterial stiffness as related to cTOD. Our comprehensive examination of the literature suggests that early identification of arterial stiffness would be a useful biomarker of future cTOD risk.