Distinct responses to warming within picoplankton communities across an environmental gradient.

Picophytoplankton are a ubiquitous component of marine plankton communities and are expected to be favored by global increases in seawater temperature and stratification associated with climate change. Eukaryotic and prokaryotic picophytoplankton have distinct ecology, and global models predict that the two groups will respond differently to future climate scenarios. At a nearshore observatory on the Northeast US Shelf, however, decades of year-round monitoring have shown these two groups to be highly synchronized in their responses to environmental variability. To reconcile the differences between regional and global predictions for picophytoplankton dynamics, we here investigate the picophytoplankton community across the continental shelf gradient from the nearshore observatory to the continental slope. We analyze flow cytometry data from 22 research cruises, comparing the response of picoeukaryote and Synechococcus communities to environmental variability across time and space. We find that the mechanisms controlling picophytoplankton abundance differ across taxa, season, and distance from shore. Like the prokaryote, Synechococcus, picoeukaryote division rates are limited nearshore by low temperatures in winter and spring, and higher temperatures offshore lead to an earlier spring bloom. Unlike Synechococcus, picoeukaryote concentration in summer decreases dramatically in offshore surface waters and exhibits deeper subsurface maxima. The offshore picoeukaryote community appears to be nutrient limited in the summer and subject to much greater loss rates than Synechococcus. This work both produces and demonstrates the necessity of taxon- and site-specific knowledge for accurately predicting the responses of picophytoplankton to ongoing environmental change.

Temperature dependence of parasitoid infection and abundance of a diatom revealed by automated imaging and classification.

Diatoms are a group of phytoplankton that contribute disproportionately to global primary production. Traditional paradigms that suggest diatoms are consumed primarily by larger zooplankton are challenged by sporadic parasitic "epidemics" within diatom populations. However, our understanding of diatom parasitism is limited by difficulties in quantifying these interactions. Here, we observe the dynamics of Cryothecomonas aestivalis (a protist) infection of an important diatom on the Northeast U.S. Shelf (NES), Guinardia delicatula, with a combination of automated imaging-in-flow cytometry and a convolutional neural network image classifier. Application of the classifier to >1 billion images from a nearshore time series and >20 survey cruises across the broader NES reveals the spatiotemporal gradients and temperature dependence of G. delicatula abundance and infection dynamics. Suppression of parasitoid infection at temperatures <4 °C drives annual cycles in both G. delicatula infection and abundance, with an annual maximum in infection observed in the fall-winter preceding an annual maximum in host abundance in the winter-spring. This annual cycle likely varies spatially across the NES in response to variable annual cycles in water temperature. We show that infection remains suppressed for ~2 mo following cold periods, possibly due to temperature-induced local extinctions of the C. aestivalis strain(s) that infect G. delicatula. These findings have implications for predicting impacts of a warming NES surface ocean on G. delicatula abundance and infection dynamics and demonstrate the potential of automated plankton imaging and classification to quantify phytoplankton parasitism in nature across unprecedented spatiotemporal scales.

Reported COVID-19 Incidence in Indoor Winter Sports Among US High-School Athletes.

OBJECTIVE: To evaluate the association between COVID-19 incidence among high-school athletes participating in different indoor winter sports and attending schools with in-person versus virtual instructional delivery. DESIGN: Cross-sectional survey. SETTING: US high schools. PARTICIPANTS: High-school athletic directors. INDEPENDENT VARIABLES: Indoor winter sports, school instructional delivery method, and state COVID-19 incidence. MAIN OUTCOME MEASURES: Surveys were distributed to high-school athletic directors throughout the United States regarding sport reinitiation and COVID-19 cases in winter 2020 to 2021. Separate mixed effects Poisson regression models were developed to evaluate the associations between reported COVID-19 incidence and (1) different sports and (2) school instructional delivery method, while adjusting for the background, state COVID-19 incidence. RESULTS: Four hundred thirty schools had restarted fall sports, representing 31 274 athletes on 1404 teams from 14 states. One thousand four hundred sixty cases of COVID-19 were reported, representing a case rate of 4668 cases per 100 000 athletes and an incidence rate of 58.7 cases per 100 000 player-days. Reported COVID-19 incidence was greatest among girls' hockey (82.1 cases per 100 000 player-days (95% CI, 56.8-115) and boys' hockey [76.7 (61.8-94.2)] and lowest among swimming [39.0 (31.1-48.2)] and gymnastics [28.5 (13.1-54.2)]. No difference in reported COVID-19 incidence was identified among athletes attending schools with virtual versus in-person instruction [incidence rate ratio = 0.86 (0.52-1.4)]. CONCLUSIONS: In this nationwide survey of US high-school athletic directors regarding indoor winter sports, reported COVID-19 incidence was lower in noncontact sports but unrelated to school instructional delivery method. This information may help guide decision-making regarding high-school sport participation during the COVID-19 pandemic.

Reported COVID-19 Incidence in Wisconsin High School Athletes in Fall 2020.

OBJECTIVE: To describe the incidence of COVID-19 in Wisconsin high school athletes and investigate the relationship of COVID-19 incidence with sport and face mask use. DESIGN: Retrospective survey. SETTING: High schools across Wisconsin during September 2020. PATIENTS OR OTHER PARTICIPANTS: Athletic directors representing 30 074 high school athletes with or without SARS-CoV-2. MAIN OUTCOME MEASUREMENT(S): The COVID-19 rates among athletes, counties, states, as well as school instruction type (virtual versus in person), sport type, and face mask use were assessed. Reported athlete case rates were compared with the county's general population and associations between COVID-19 incidence and sport type and face mask use, adjusting for each school's county incidence using multivariable negative binomial regression models. RESULTS: The COVID-19 incidence rates for 207 of 244 responding schools were 32.6 cases per 100 000 player-days. Reported case rates for athletes in each county were positively correlated with the county's general population case rates (ß = 1.14 ± 0.20, r = 0.60, P < .001). One case (0.5%) was attributed to sport contact by the reporting schools. No difference was identified between team and individual sports (incidence rate ratio [IRR] = 1.03 [95% CI = 0.49, 2.2], P = .93) or between noncontact and contact sports (IRR = 0.53 [0.23, 1.3], P = .14). Outdoor sports had a lower incidence rate than indoor sports, although this finding did not reach statistical significance (IRR = 0.52 [0.26, 1.1], P = .07). No significant associations were found between COVID-19 incidence and face mask use during play for those sports with greater than 50 schools reporting on face mask use (P values > .05). CONCLUSIONS: The incidence of reported COVID-19 among high school athletes was related to the county incidence, and most cases were attributed to nonsport contact. A lower COVID-19 incidence in outdoor sports approached statistical significance. The lack of a significant benefit demonstrated for face mask use may be due to relatively low rates of COVID-19 in Wisconsin during September 2020. Further research is needed to better define COVID-19 transmission risk factors during adolescent sport participation.

The Association of COVID-19 Incidence with Sport and Face Mask Use in United States High School Athletes.

CONTEXT: The relationships between different sports, face mask use and COVID-19 risk among high school athletes remains unknown. OBJECTIVE: The purpose of this study was to evaluate the influence of sport characteristics and face mask use on COVID-19 incidence among high school athletes. DESIGN: Descriptive Epidemiology Study Setting: United States High School Athletic Departments Participants: Athletic Directors Interventions: None Main Outcome Measures: Surveys were completed regarding sport re-initiation, COVID-19 cases, and risk reduction procedures in fall 2020. Separate mixed effects Poisson regression models were developed to evaluate the associations between reported COVID-19 incidence and 1) sport characteristics (contact/non-contact, individual/team, indoor/outdoor) and 2) face mask use while playing (yes/no). RESULTS: 991 schools had restarted fall sports, representing 152,484 athletes on 5,854 teams. 2,565 cases of COVID-19 were reported, representing a case rate of 1,682 cases per 100,000 athletes and an incidence rate of 24.6 cases per 100,000 player-days. COVID-19 incidence was lower among outdoor versus indoor sports (incidence rate ratio [IRR]=0.54, 95% CI=0.49-0.60, p<0.001) and non-contact versus contact sports (IRR=0.78 [0.70-0.87], p<0.001), but not team versus individual sports (IRR=0.96 [0.84-1.1], p=0.49). Face mask use was associated with a decreased incidence in girls' volleyball (IRR=0.53 [0.37-0.73], p<0.001), boys' basketball (IRR=0.53 [0.33-0.83], p=0.008) and girls' basketball (IRR=0.36 [0.19-0.63], p<0.001), and approached statistical significance in football (IRR=0.79 [0.59-1.04], p=0.10) and cheer/dance (IRR=0.75 [0.53-1.03], p=0.081). CONCLUSIONS: In this nationwide survey of high school athletes, lower COVID-19 incidence was independently associated with participation in outdoor versus indoor and non-contact versus contact sports, but not team versus individual sports. Face mask use was associated with decreased COVID-19 incidence among indoor sports, and may be protective among outdoor sports with prolonged close contact between participants.

COVID-19 in US Youth Soccer Athletes During Summer 2020.

CONTEXT: As sports are reinitiated around the United States, the incidence of COVID-19 among youth soccer athletes remains unknown. OBJECTIVE: To determine the incidence of COVID-19 among youth soccer athletes and the risk-mitigation practices used by youth soccer organizations. DESIGN: Cohort study. SETTING: Survey distributed to Elite Clubs National League member clubs. PATIENTS OR OTHER PARTICIPANTS: Youth soccer club directors throughout the United States. MAIN OUTCOME MEASURE(S): Surveys were completed in late August 2020 regarding the club's current phase of return to soccer (individual only, group noncontact, group contact), date of reinitiation, number of players, cases of COVID-19, and risk-reduction procedures being implemented. Case and incidence rates were compared with national pediatric data and county data from the prior 10 weeks. A negative binomial regression model was developed to predict club COVID-19 cases using the local incidence rate and phase of return as covariates and the log of club player-days as an offset. RESULTS: A total of 124 respondents had reinitiated soccer, representing 91 007 players with a median duration of 73 days (interquartile range = 53-83 days) since restarting. Of the 119 clubs that had progressed to group activities, 218 cases of COVID-19 were reported among 85 861 players. Youth soccer players had a lower case rate and incidence rate than children in the United States (254 versus 477 cases per 100 000; incidence rate ratio = 0.511, 95% CI = 0.40, 0.57; P < .001) and the general population in the counties where data were available (268 versus 864 cases per 100 000; incidence rate ratio = 0.202, 95% CI = 0.19, 0.21; P < .001). After adjusting for the local COVID-19 incidence, we found no relationship between the club COVID-19 incidence and the phase of return (noncontact: b = 0.35 ± 0.67, P = .61; contact: b = 0.18 ± 0.67, P = .79). Soccer clubs reported using a median of 8 (interquartile range = 6-10) risk-reduction procedures. CONCLUSIONS: The incidence of COVID-19 among youth soccer athletes was relatively low when compared with the background incidence among children in the United States during the summer of 2020. No relationship was identified between the club COVID-19 incidence and the phase of return to soccer.

Looking back while moving forward: a justice-based, intersectional approach to research on contraception and disability.

For the first time in the 21st century, we have an emerging body of research regarding contraceptive use among adult women with disabilities in the United States. We highlight key findings from population-based analyses that found higher odds of female sterilization and lower odds of long-acting reversible contraception use among women with disabilities compared to their peers without disabilities. We consider potential reasons underlying these differences, including discriminatory attitudes and policies that restrict the sexual and reproductive autonomy of people with disabilities. We advocate for a justice-based, intersectional approach to research on contraception and disability with the aim of promoting the reproductive autonomy of people with disabilities.