Ecological Diversification in an Adaptive Radiation of Plants: The Role of De Novo Mutation and Introgression.

Adaptive radiations are characterized by rapid ecological diversification and speciation events, leading to fuzzy species boundaries between ecologically differentiated species. Adaptive radiations are therefore key systems for understanding how species are formed and maintained, including the role of de novo mutations versus preexisting variation in ecological adaptation and the genome-wide consequences of hybridization events. For example, adaptive introgression, where beneficial alleles are transferred between lineages through hybridization, may fuel diversification in adaptive radiations and facilitate adaptation to new environments. In this study, we employed whole-genome resequencing data to investigate the evolutionary origin of hummingbird-pollinated flowers and to characterize genome-wide patterns of phylogenetic discordance and introgression in Penstemon subgenus Dasanthera, a small and diverse adaptive radiation of plants. We found that magenta hummingbird-adapted flowers have apparently evolved twice from ancestral blue-violet bee-pollinated flowers within this radiation. These shifts in flower color are accompanied by a variety of inactivating mutations to a key anthocyanin pathway enzyme, suggesting that independent de novo loss-of-function mutations underlie the parallel evolution of this trait. Although patterns of introgression and phylogenetic discordance were heterogenous across the genome, a strong effect of gene density suggests that, in general, natural selection opposes introgression and maintains genetic differentiation in gene-rich genomic regions. Our results highlight the importance of both de novo mutation and introgression as sources of evolutionary change and indicate a role for de novo mutation in driving parallel evolution in adaptive radiations.

A qualitative approach to understanding the drivers of unequal receipt of definitive therapy for Black men with prostate cancer in Massachusetts.

BACKGROUND: Despite mandated insurance coverage since 2006 and robust health infrastructure in urban settings with high concentrations of minority patients, race-based disparities in prostate cancer (PCa) treatment persist in Massachusetts. In this qualitative study, the authors sought to identify factors driving inequities in PCa treatment in Massachusetts. METHODS: Four hospitals offering PCa treatment in Massachusetts were selected using a case-mix approach. Purposive sampling was used to conduct semistructured interviews with hospital stakeholders. Additional interviews were conducted with representatives from grassroots organizations providing PCa education. Two study staff coded the interviews to identify major themes and recurrent patterns. RESULTS: Of the 35 informants invited, 25 participated in the study. Although national disparities in PCa outcomes were readily discussed, one half of the informants were unaware that PCa disparities existed in Massachusetts. Informants and grassroots organization representatives acknowledged that patients with PCa are willing to face transportation barriers to receive treatment from trusted and accommodating institutions. Except for chief equity officers, most health care providers lacked knowledge on accessing or using metrics regarding racial disparities in cancer outcomes. Although community outreach was recognized as a potential strategy to reduce treatment disparities and engender trust, informants were often unable to provide a clear implementation plan. CONCLUSIONS: This statewide qualitative study builds on existing quantitative data on the nature and extent of disparities. It highlights knowledge gaps in recognizing and addressing racial disparities in PCa treatment in Massachusetts. Improved provider awareness, the use of disparity metrics, and strategic community engagement may ensure equitable access to PCa treatment. PLAIN LANGUAGE SUMMARY: Despite mandated insurance and urban health care access, racial disparities in prostate cancer treatment persist in Massachusetts. This qualitative study revealed that, although national disparities were acknowledged, awareness about local disparities are lacking. Stakeholders highlighted the importance of ancillary services, including translators, rideshares, and navigators, in the delivery of care. In addition, whereas hospital stakeholders were aware of collected equity outcomes, they were unsure whether and who is monitoring equity metrics. Furthermore, stakeholders agreed that community outreach showed promise in ensuring equitable access to prostate cancer treatment. Nevertheless, most interviewed stakeholders lacked clear implementation plans.

The effect of limited english proficiency on prostate-specific antigen screening in American men.

PURPOSE: To evaluate how limited English proficiency (LEP) impacts the prevalence of prostate-specific antigen (PSA) screening in a contemporary, nationally representative cohort of men in the USA. METHODS: The Medical Expenditure Panel Survey was utilized to identify the prevalence of PSA screening between 2013 and 2016 among men ≥ 55. Men who speak a language other than English at home were stratified by self-reported levels of English proficiency (men who speak English very well, well, not well, or not at all). Survey weights were applied, and groups were compared using the adjusted Wald test. A multivariable logistic regression model was used to identify predictors of PSA screening adjusting for patient-level covariates. RESULTS: The cohort included 2,889 men, corresponding to a weighted estimate of 4,765,682 men. 79.6% of men who speak English very well reported receiving at least one lifetime PSA test versus 58.4% of men who do not speak English at all (p < 0.001). Men who reported not speaking English at all had significantly lower prevalence of PSA screening (aOR 0.56; 95% CI 0.35-0.91; p = 0.019). Other significant predictors of PSA screening included older age, income > 400% of the federal poverty level, insurance coverage, and healthcare utilization. CONCLUSIONS: Limited English proficiency is associated with significantly lower prevalence of PSA screening among men in the USA. Interventions to mitigate disparities in prostate cancer outcomes should account for limited English proficiency among the barriers to guideline-concordant care.

Smoking characteristics and years since quitting smoking of US adults diagnosed with lung and bladder cancer: A national health and nutrition examination survey analysis.

PURPOSE: Smoking is a recognized risk factor for bladder BC and lung cancer LC. We investigated the enduring risk of BC after smoking cessation using U.S. national survey data. Our analysis focused on comparing characteristics of LC and BC patients, emphasizing smoking status and the latency period from smoking cessation to cancer diagnosis in former smokers. MATERIALS AND METHODS: We analyzed data from the National Health and Examination Survey (2003-2016), identifying adults with LC or BC history. Smoking status (never, active, former) and the interval between quitting smoking and cancer diagnosis for former smokers were assessed. We reported descriptive statistics using frequencies and percentages for categorical variables and median with interquartile ranges (IQR) for continuous variables. RESULTS: Among LC patients, 8.9% never smoked, 18.9% active smokers, and 72.2% former smokers. Former smokers had a median interval of 8 years (IQR 2-12) between quitting and LC diagnosis, with 88.3% quitting within 0-19 years before diagnosis. For BC patients, 26.8% never smoked, 22.4% were active smokers, and 50.8% former smokers. Former smokers had a median interval of 21 years (IQR 14-33) between quitting and BC diagnosis, with 49.3% quitting within 0-19 years before diagnosis. CONCLUSIONS: BC patients exhibit a prolonged latency period between smoking cessation and cancer diagnosis compared to LC patients. Despite smoking status evaluation in microhematuria, current risk stratification models for urothelial cancer do not incorporate it. Our findings emphasize the significance of long-term post-smoking cessation surveillance and advocate for integrating smoking history into future risk stratification guidelines.

Effect of type of definitive treatment on race-based differences in prostate cancer-specific survival.

BACKGROUND: Racial and ethnic disparities in prostate cancer (PCa) mortality are partially mediated by inequities in quality of care. Intermediate- and high-risk PCa can be treated with either surgery or radiation, therefore we designed a study to assess the magnitude of race-based differences in cancer-specific survival between these two treatment modalities. METHODS: Non-Hispanic Black (NHB) and non-Hispanic White (NHW) men with localized intermediate- and high-risk PCa, treated with surgery or radiation between 2004 and 2015 in the Surveillance, Epidemiology and End Results database were included in the study and followed until December 2018. Unadjusted and adjusted survival analyses were employed to compare cancer-specific survival by race and treatment modality. A model with an interaction term between race and treatment was used to assess whether the type of treatment amplified or attenuated the effect of race/ethnicity on prostate cancer-specific mortality (PCSM). RESULTS: 15,178 (20.1%) NHB and 60,225 (79.9%) NHW men were included in the study. NHB men had a higher cumulative incidence of PCSM (p = 0.005) and were significantly more likely to be treated with radiation than NHW men (aOR: 1.89, 95% CI: 1.81-1.97, p < 0.001). In the adjusted models, NHB men were significantly more likely to die from PCa compared with NHW men (aHR: 1.18, 95% CI: 1.03-1.35, p = 0.014), and radiation was associated with a significantly higher odds of PCSM (aHR: 2.10, 95% CI: 1.85-2.38, p < 0.001) compared with surgery. Finally, the interaction between race and treatment on PCSM was not significant, meaning that no race-based differences in PCSM were found within each treatment modality. CONCLUSIONS: NHB men with intermediate- and high-risk PCa had a higher rate of PCSM than NWH men in a large national cancer registry, though NHB and NHW men managed with the same treatment achieved similar PCa survival outcomes. The higher tendency for NHB men to receive radiation was similar in magnitude to the difference in cancer survival between racial and ethnic groups.

Testing hypotheses of hybrid taxon formation in the shrubby beardtongues (Penstemon subgenus Dasanthera).

PREMISE: Hybridization is increasingly being identified in the genomes of species across the tree of life, leading to a general recognition that hybridization plays an important role in the generation of species diversity. While hybridization may increase species diversity directly via the formation of new taxa through hybrid speciation, it may also act indirectly via the exchange of phenotypic and genetic variance between species, which may in turn stimulate future speciation events. METHODS: Using high-throughput sequence data, we resolved phylogenetic relationships and investigated the role of hybridization as a diversification mechanism in the shrubby beardtongues (Penstemon subgenus Dasanthera), a group of North American wildflowers that has undergone a recent and rapid adaptive radiation. Specifically, we tested four hypotheses of hybrid taxon formation resulting from hybridization between P. davidsonii and P. fruticosus. RESULTS: Species tree inference supports the monophyly of subgenus Dasanthera and elucidates relationships between taxa distributed in the Cascades and Sierra Nevada Mountains. Results also provide evidence of gene flow between P. davidsonii and P. fruticosus and support at least one hybrid origin hypothesis (P. davidsonii var. menziesii) in a region of contemporary distributional overlap. Hybridization may have also been facilitated by historical overlap in geographic distribution caused by species' responses to climatic changes during the Pleistocene. CONCLUSIONS: Our results support a history of hybridization between focal taxa in a rapidly radiating clade of plants and more broadly contribute to our growing understanding of the role of hybridization as a diversification mechanism in plants.

Validating a forced-choice method for eliciting quality-of-reasoning judgments.

In this paper we investigate the criterion validity of forced-choice comparisons of the quality of written arguments with normative solutions. Across two studies, novices and experts assessing quality of reasoning through a forced-choice design were both able to choose arguments supporting more accurate solutions-62.2% (SE = 1%) of the time for novices and 74.4% (SE = 1%) for experts-and arguments produced by larger teams-up to 82% of the time for novices and 85% for experts-with high inter-rater reliability, namely 70.58% (95% CI = 1.18) agreement for novices and 80.98% (95% CI = 2.26) for experts. We also explored two methods for increasing efficiency. We found that the number of comparative judgments needed could be substantially reduced with little accuracy loss by leveraging transitivity and producing quality-of-reasoning assessments using an AVL tree method. Moreover, a regression model trained to predict scores based on automatically derived linguistic features of participants' judgments achieved a high correlation with the objective accuracy scores of the arguments in our dataset. Despite the inherent subjectivity involved in evaluating differing quality of reasoning, the forced-choice paradigm allows even novice raters to perform beyond chance and can provide a valid, reliable, and efficient method for producing quality-of-reasoning assessments at scale.

Real-World Outcomes of Direct-Acting Antiviral Treatment and Retreatment in United Kingdom-Based Patients Infected With Hepatitis C Virus Genotypes/Subtypes Endemic in Africa.

BACKGROUND: Chronic hepatitis C virus (HCV) infection affects 71 million individuals, mostly residing in low- and middle-income countries (LMICs). Direct-acting antivirals (DAAs) give high rates of sustained virological response (SVR) in high-income countries where a restricted range of HCV genotypes/subtypes circulate. METHODS: We studied United Kingdom-resident patients born in Africa to examine DAA effectiveness in LMICs where there is far greater breadth of HCV genotypes/subtypes. Viral genome sequences were determined from 233 patients. RESULTS: Full-length viral genomic sequences for 26 known subtypes and 5 previously unidentified isolates covering 5 HCV genotypes were determined. From 149 patients who received DAA treatment/retreatment, the overall SVR was 93%. Treatment failure was associated primarily with 2 subtypes, gt1l and gt4r, using sofosbuvir/ledipasvir. These subtypes contain natural resistance-associated variants that likely contribute to poor efficacy with this drug combination. Treatment failure was also significantly associated with hepatocellular carcinoma. CONCLUSIONS: DAA combinations give high SVR rates despite the high HCV diversity across the African continent except for subtypes gt1l and gt4r, which respond poorly to sofosbuvir/ledipasvir. These subtypes are widely distributed across Western, Central, and Eastern Africa. Thus, in circumstances where accurate genotyping is absent, ledipasvir and its generic compounds should not be considered as a recommended treatment option.

SAR11 bacteria linked to ocean anoxia and nitrogen loss.

Bacteria of the SAR11 clade constitute up to one half of all microbial cells in the oxygen-rich surface ocean. SAR11 bacteria are also abundant in oxygen minimum zones (OMZs), where oxygen falls below detection and anaerobic microbes have vital roles in converting bioavailable nitrogen to N2 gas. Anaerobic metabolism has not yet been observed in SAR11, and it remains unknown how these bacteria contribute to OMZ biogeochemical cycling. Here, genomic analysis of single cells from the world's largest OMZ revealed previously uncharacterized SAR11 lineages with adaptations for life without oxygen, including genes for respiratory nitrate reductases (Nar). SAR11 nar genes were experimentally verified to encode proteins catalysing the nitrite-producing first step of denitrification and constituted ~40% of OMZ nar transcripts, with transcription peaking in the anoxic zone of maximum nitrate reduction activity. These results link SAR11 to pathways of ocean nitrogen loss, redefining the ecological niche of Earth's most abundant organismal group.

Disparate Practice Patterns and Survival Outcomes: The Impact of Centralization of Cancer Care for Adrenocortical Carcinoma in the United States.

PURPOSE: Adrenocortical carcinoma is a rare but aggressive malignancy. While centralization of care to referral centers improves outcomes across common urological malignancies, there exists a paucity of data for low-incidence cancers. We sought to evaluate differences in practice patterns and overall survival in patients with adrenocortical carcinoma across types of treating facilities. MATERIALS AND METHODS: We identified all patients diagnosed with adrenocortical carcinoma from 2004-2016 in the National Cancer Database. The Kaplan-Meier method was used to evaluate overall survival and multivariable Cox regression analysis was used to investigate independent predictors of overall survival. The chi-square test was used to analyze differences in practice patterns. RESULTS: We identified 2,886 patients with adrenocortical carcinoma. Median overall survival was 21.8 months (95% CI 19.8-23.8). Academic centers had improved overall survival versus community centers on unadjusted Kaplan-Meier analysis (p <0.05) and had higher rates of adrenalectomy or radical en bloc resection (p <0.001), performed more open surgery (p <0.001), administered more systemic therapy (p <0.001) and had lower rates of positive surgical margins (p=0.03). On multivariable analysis, controlling for treatment modality, academic centers were associated with significantly decreased risk of death (HR 0.779, 95% CI 0.631-0.963, p=0.021). CONCLUSIONS: Treatment of adrenocortical carcinoma at an academic center is associated with improved overall survival compared to community programs. There are significant differences in practice patterns, including more aggressive surgical treatment at academic facilities, but the survival benefit persists on multivariable analysis controlling for treatment modality. Further studies are needed to identify the most important predictors of survival in this at-risk population.

MOSESTM Technology for Holmium Laser Enucleation of the Prostate: A Prospective Double-Blind Randomized Controlled Trial.

PURPOSE: Holmium laser enucleation of the prostate has proven to be efficacious and safe for the treatment of benign prostatic hyperplasia. New laser technologies, such as the MOSES™ pulse laser system, improve energy delivery and may improve operative times. We sought to prospectively evaluate holmium laser enucleation of the prostate using MOSES technology in a double-blind randomized controlled trial. MATERIALS AND METHODS: This is a single-center, prospective, double-blind, randomized controlled trial comparing holmium laser enucleation of the prostate using MOSES technology to holmium laser enucleation of the prostate. Patients were randomized in a 1:1 fashion. The study was powered to evaluate for a difference in operative time. Secondary end points included enucleation, morcellation, and hemostasis times, as well as blood loss, functional outcomes and complications 6 weeks postoperatively. RESULTS: A total of 60 patients were analyzed without difference in preoperative characteristics in either group (holmium laser enucleation of the prostate using MOSES technology: 30/60, 50%, holmium laser enucleation of the prostate: 30/60, 50%). Shorter total operative time was seen in the holmium laser enucleation of the prostate using MOSES technology group compared to the holmium laser enucleation of the prostate group (mean: 101 vs. 126 minutes, p <0.01). This difference remained significant on multiple linear regression. Additionally, the holmium laser enucleation of the prostate using MOSES technology group had shorter enucleation times (mean: 68 vs. 80 minutes, p=0.03), hemostasis time (mean: 18 vs. 29 minutes, p <0.01), and less blood loss (mean: -6.3 vs. -9.0%, p=0.03), measured by a smaller change in hematocrit postoperatively, compared to the traditional holmium laser enucleation of the prostate. There was no difference in functional or safety outcomes at followup. CONCLUSIONS: We report the results of a prospective, double-blind, randomized controlled trial comparing holmium laser enucleation of the prostate using MOSES technology to traditional holmium laser enucleation of the prostate. MOSES technology resulted in an improvement in operative time and a reduction in blood loss with comparable functional outcomes and complications compared to traditional holmium laser enucleation of the prostate.

Patient-Reported Financial Toxicity Associated with Contemporary Treatment for Localized Prostate Cancer.

PURPOSE: Contemporary treatment modalities for localized prostate cancer provide comparable overall and cancer-specific survival. However, the degree of financial burden imposed by treatment, the factors contributing to that burden, and how different treatments compare with regard to financial toxicity remain poorly understood. MATERIALS AND METHODS: The Comparative Effectiveness Analysis of Surgery and Radiation (CEASAR) study enrolled men with localized prostate cancer from 2011 to 2012. Questionnaires were collected at 6, 12, 36, and 60 months after enrollment. Differences in patient-reported financial burden were compared between active surveillance, radical prostatectomy, and external beam radiotherapy using multivariable logistic regression. RESULTS: Among 2,121 patients meeting inclusion criteria, 15% reported large or very large burden of treatment costs within 6 months, declining to 3% by year 5. When controlling for age, education, income and other covariates, external beam radiotherapy was associated with greater financial burden than active surveillance and radical prostatectomy at 1 year (OR 2.2, 95% CI 1.2-4.1 and OR 1.5, 95% CI 1.0-2.3, respectively) and 3 years (OR 3.1 95% CI 1.1-8.8 and OR 2.1, 95% CI 1.2-3.7, respectively). Radical prostatectomy and active surveillance had similar rates of financial burden at all time points. Age, race, education, and D'Amico risk group were associated with financial burden. CONCLUSIONS: External beam radiotherapy was associated with the highest financial burden, even when controlling for age, education and income. Prospective studies that directly measure out-of-pocket and indirect costs and account more thoroughly for baseline socioeconomic differences are warranted in order to identify those most at risk.

Phylogeographic analysis of shrubby beardtongues reveals range expansions during the Last Glacial Maximum and implicates the Klamath Mountains as a hotspot for hybridization.

Quaternary glacial cycles often altered species' geographic distributions, which in turn altered the geographic structure of species' genetic diversity. In many cases, glacial expansion forced species in temperate climates to contract their ranges and reside in small pockets of suitable habitat (refugia), where they were likely to interact closely with other species, setting the stage for potential gene exchange. These introgression events, in turn, would have degraded species boundaries, making the inference of phylogenetic relationships challenging. Using high-throughput sequence data, we employed a combination of species distribution models and hybridization tests to assess the effect of glaciation on the geographic distributions, phylogenetic relationships, and patterns of gene flow of five species of Penstemon subgenus Dasanthera, long-lived shrubby angiosperms distributed throughout the Pacific Northwest of North America. Surprisingly, we found that rather than reducing their ranges to small refugia, most Penstemon subgenus Dasanthera species experienced increased suitable habitat during the Last Glacial Maximum relative to the present day. We also found substantial evidence for gene exchange between species, with the bulk of introgression events occurring in or near the Klamath Mountains of southwestern Oregon and northwestern California. Subsequently, our phylogenetic inference reveals blurred taxonomic boundaries in the Klamath Mountains, where introgression is most prevalent. Our results question the classical paradigm of temperate species' responses to glaciation and highlight the importance of contextualizing phylogenetic inference with species' histories of introgression.

The Fallacy of an Airtight Alibi: Understanding Human Memory for "Where" Using Experience Sampling.

A primary challenge for alibi-generation research is establishing the ground truth of real-world events of interest. In the current study, we used a smartphone app to record data on adult participants (N = 51) for a month prior to a memory test. The app captured accelerometry data, GPS locations, and audio environments every 10 min. After a week-long retention interval, we asked participants to identify where they were at a given time from among four alternatives. Participants were incorrect 36% of the time. Furthermore, our forced-choice procedure allowed us to conduct a conditional logit analysis to assess the different aspects of the events that the participants experienced and their relative importance to the decision process. We found strong evidence that participants confuse days across weeks. In addition, people often confused weeks in general and also hours across days. Similarity of location induced more errors than similarity of audio environments or movement types.

Physiology of handcycling: A current sports perspective.

Handcycling is a mode of mobility, and sport format within Para-cycling, for those with a lower limb impairment. The exercise modality has been researched extensively in the rehabilitation setting. However, there is an emerging body of evidence detailing the physiological responses to handcycling in the competitive sport domain. Competitive handcyclists utilize equipment that is vastly disparate to that used for rehabilitation or recreation. Furthermore, the transferability of findings from early handcycling research to current international athletes regarding physiological profiles is severely limited. This narrative review aims to map the landscape within handcycling research and document the growing interest at the elite end of the exercise spectrum. From 58 experimental/case studies and four doctoral theses, we provide accounts of the aerobic capacity of handcyclists and the influence training status plays; present research regarding the physiological responses to handcycling performance, including tests of sprint performance; and discuss the finite information on handcyclists' training habits and efficacy of bespoke interventions. Furthermore, given the wide variety of protocols employed and participants recruited previously, we present considerations for the interpretation of existing research and recommendations for future work, all with a focus on competitive sport. The majority of studies (n = 21) reported aerobic capacity, detailing peak rates of oxygen uptake and power output, with values >3.0 L min-1 and 240 W shown in trained, male H3-H4 classification athletes. Knowledge, though, is lacking for other classifications and female athletes. Similarly, little research is available concerning sprint performance with only one from eight studies recruiting athletes with an impairment.

Crank length alters kinematics and kinetics, yet not the economy of recumbent handcyclists at constant handgrip speeds.

Handcycling performance is dependent on the physiological economy of the athlete; however, handbike configuration and the biomechanical interaction between the two are also vital. The purpose of this study was to examine the effect of crank length manipulations on physiological and biomechanical aspects of recumbent handcycling performance in highly trained recumbent handcyclists at a constant linear handgrip speed and sport-specific intensity. Nine competitive handcyclists completed a 3-minute trial in an adjustable recumbent handbike in four crank length settings (150, 160, 170 & 180 mm) at 70% peak power output. Handgrip speed was controlled (1.6 m·s-1 ) across trials with cadences ranging from 102 to 85 rpm. Physiological economy, heart rate, and ratings of perceived exertion were monitored in all trials. Handcycling kinetics were quantified using an SRM (Schoberer Rad Messtechnik) powermeter, and upper limb kinematics were determined using a 10-camera VICON motion capture system. Physiological responses were not significantly affected by crank length. However, greater torque was generated (P < .0005) and peak torque occurred earlier during the push and pull phase (P ≤ .001) in longer cranks. Statistical parametric mapping revealed that the timing and orientation of shoulder flexion, shoulder abduction, and elbow extension were significantly altered in different crank lengths. Despite the biomechanical adaptations, these findings suggest that at constant handgrip speeds (and varying cadence) highly trained handcyclists may select crank lengths between 150 and 180 mm without affecting their physiological performance. Until further research, factors such as anthropometrics, comfort, and self-selected cadence should be used to facilitate crank length selection in recumbent handcyclists.

Challenges and opportunities for sustaining coastal wetlands and oyster reefs in the southeastern United States.

Formed at the confluence of marine and fresh waters, estuaries experience both the seaside pressures of rising sea levels and increasing storm severity, and watershed and precipitation changes that are shifting the quality and quantity of freshwater and sediments delivered from upstream sources. Boating, shoreline hardening, harvesting pressure, and other signatures of human activity are also increasing as populations swell in coastal regions. Given this shifting landscape of pressures, the factors most threatening to estuary health and stability are often uncertain. To identify the greatest contemporary threats to coastal wetlands and oyster reefs across the southeastern United States (Mississippi to North Carolina), we summarized recent population growth and land-cover change and surveyed estuarine management and science experts. From 1996 to 2019, human population growth in the region varied from a 17% decrease to a 171% increase (mean = +43%) with only 5 of the 72 SE US counties losing population, and nearly half growing by more than 40%. Individual counties experienced between 999 and 19,253 km2 of new development (mean: 5725 km2), with 1-5% (mean: 2.6%) of undeveloped lands undergoing development over this period across the region. Correspondingly, our survey of 169 coastal experts highlighted development, shoreline hardening, and upstream modifications to freshwater flow as the most important local threats facing coastal wetlands. Similarly, experts identified development, upstream modifications to freshwater flow, and overharvesting as the most important local threats to oyster reefs. With regards to global threats, experts categorized sea level rise as the most pressing to wetlands, and acidification and precipitation changes as the most pressing to oyster reefs. Survey respondents further identified that more research, driven by collaboration among scientists, engineers, industry professionals, and managers, is needed to assess how precipitation changes, shoreline hardening, and sea level rise are affecting coastal ecosystem stability and function. Due to the profound role of humans in shaping estuarine health, this work highlights that engaging property owners, recreators, and municipalities to implement strategies to improve estuarine health will be vital for sustaining coastal systems in the face of global change.

Physiological responses during simulated 16 km recumbent handcycling time trial and determinants of performance in trained handcyclists.

PURPOSE: To characterise the physiological profiles of trained handcyclists, during recumbent handcycling, to describe the physiological responses during a 16 km time trial (TT) and to identify the determinants of this TT performance. METHODS: Eleven male handcyclists performed a sub-maximal and maximal incremental exercise test in their recumbent handbike, attached to a Cyclus II ergometer. A physiological profile, including peak aerobic power output (POPeak), peak rate of oxygen uptake ([Formula: see text]O2Peak), aerobic lactate threshold (AeLT) and PO at 4 mmol L-1 (PO4), were determined. Participants also completed a 16 km simulated TT using the same experimental set-up. Determinants of TT performance were identified using stepwise multiple linear regression analysis. RESULTS: Mean values of POPeak = 252 ± 9 W, [Formula: see text]O2Peak = 3.30 ± 0.36 L min-1 (47.0 ± 6.8 mL kg-1 min-1), AeLT = 87 ± 13 W and PO4 = 154 ± 14 W were recorded. The TT was completed in 29:21 ± 0:59 min:s at an intensity equivalent to 69 ± 4% POPeak and 87 ± 5% [Formula: see text]O2Peak. POPeak (r = - 0.77, P = 0.006), PO4 (r = - 0.77, P = 0.006) and AeLT (r = - 0.68, P = 0.022) were significantly correlated with TT performance. PO4 and POPeak were identified as the best predictors of TT performance (r = 0.89, P < 0.001). CONCLUSION: POPeak, PO4 and AeLT are important physiological TT performance determinants in trained handcyclists, differentiating between superior and inferior performance, whereas [Formula: see text]O2peak was not. The TT took place at an intensity corresponding to 69% POPeak and 87% [Formula: see text]O2peak.

Shoulder and thorax kinematics contribute to increased power output of competitive handcyclists.

Current knowledge of recumbent handbike configuration and handcycling technique is limited. The purpose of this study was to evaluate and compare the upper limb kinematics and handbike configurations of recreational and competitive recumbent handcyclists, during sport-specific intensities. Thirteen handcyclists were divided into two significantly different groups based on peak aerobic power output (POpeak ) and race experience; competitive (n = 7; 5 H3 and 2 H4 classes; POpeak : 247 ± 20 W) and recreational (n = 6; 4 H3 and 2 H4 classes; POpeak : 198 ± 21 W). Participants performed bouts of exercise at training (50% POpeak ), competition (70% POpeak ), and sprint intensity while three-dimensional kinematic data (thorax, scapula, shoulder, elbow, and wrist) were collected. Statistical parametric mapping was used to compare the kinematics of competitive and recreational handcyclists. Handbike configurations were determined from additional markers on the handbike. Competitive handcyclists flexed their thorax (~5°, P < 0.05), extended their shoulder (~10°, P < 0.01), and posteriorly tilted their scapular (~15°, P < 0.05) more than recreational handcyclists. Differences in scapular motion occurred only at training intensity while differences in shoulder extension and thorax flexion occurred both at training and competition intensities. No differences were observed during sprinting. No significant differences in handbike configuration were identified. This study is the first to compare the upper limb kinematics of competitive recreational handcyclists at sport-specific intensities. Competitive handcyclists employed significantly different propulsion strategies at training and competition intensities. Since no differences in handbike configuration were identified, these kinematic differences could be due to technical training adaptations potentially optimizing muscle recruitment or force generation of the arm.