TEMPERATURE AND SALINITY AFFECT DEVELOPMENT OF THE PARASITIC SEA ANEMONE EDWARDSIELLA LINEATA POTENTIALLY LIMITING ITS IMPACT AS A BIOLOGICAL CONTROL ON THE CTENOPHORE MNEMIOPSIS LEIDYI.

The lined sea anemone, Edwardsiella lineata, parasitizes the ctenophore Mnemiopsis leidyi, which is one of the most destructive marine invasive species in the world. Mnemiopsis leidyi is known to tolerate a wide range of environmental conditions. However, the environmental tolerances of its most prominent parasite have never been characterized. Here we determined the effects of temperature (18, 22, 26, and 30 C) and salinity (6, 15, 24, and 33 ppt) on the survival and development of E. lineata from a vermiform parasite to a free-living polyp. At higher temperatures and lower salinities, E. lineata experienced significantly higher mortality, and it failed to develop into an adult polyp at the highest temperature (30 C) and lowest salinities we tested (6 ppt or 15 ppt). While such temperature and salinity restrictions would not currently prevent E. lineata from infecting M. leidyi in many of the European waters where it has become a destructive invasive species, these environmental limitations may be reducing overlap between host and parasite within the host's native range, a situation that could be exacerbated by climate change.

Reliability of COVID-19 data: An evaluation and reflection.

IMPORTANCE: The rapid proliferation of COVID-19 has left governments scrambling, and several data aggregators are now assisting in the reporting of county cases and deaths. The different variables affecting reporting (e.g., time delays in reporting) necessitates a well-documented reliability study examining the data methods and discussion of possible causes of differences between aggregators. OBJECTIVE: To statistically evaluate the reliability of COVID-19 data across aggregators using case fatality rate (CFR) estimates and reliability statistics. DESIGN, SETTING, AND PARTICIPANTS: Cases and deaths were collected daily by volunteers via state and local health departments, as primary sources and newspaper reports, as secondary sources. In an effort to begin comparison for reliability statistical analysis, BroadStreet collected data from other COVID-19 aggregator sources, including USAFacts, Johns Hopkins University, New York Times, The COVID Tracking Project. MAIN OUTCOMES AND MEASURES: COVID-19 cases and death counts at the county and state levels. RESULTS: Lower levels of inter-rater agreement were observed across aggregators associated with the number of deaths, which manifested itself in state level Bayesian estimates of COVID-19 fatality rates. CONCLUSIONS AND RELEVANCE: A national, publicly available data set is needed for current and future disease outbreaks and improved reliability in reporting.

Acidogenicity and acid tolerance of Streptococcus oralis and Streptococcus mitis isolated from plaque of healthy and incipient caries teeth.

BACKGROUND: Non-mutans low pH oral streptococci are postulated to contribute to caries etiology. OBJECTIVE: This study was undertaken to investigate whether the acidogenicity and acid tolerance of clinical strains of Streptococcus oralis and Streptococcus mitis correlate with health or early-stage enamel caries. DESIGN: S. oralis and S. mitis were isolated from plaque samples taken from the occlusal surfaces of second molars sampled at two different visits 4 years apart. All sites were sound at Visit 1; subjects were segregated into one of three groups based on the status of the site at Visit 2 and caries elsewhere in the dentition. Strains of S. oralis and S. mitis were evaluated for acidogenicity and acid tolerance, and the results correlated with the clinical status of the sites from which they were isolated. Mutans streptococci (MS) isolated from the plaque samples were also quantified, and the presence or absence of growth on pH 5.5 media or on media selective for bifidobacteria was recorded. RESULTS: No significant positive correlations were found between the acidogenicity properties of the S. oralis and S. mitis clones and caries at either visit. Similar results were obtained for acid tolerance of S. oralis clones but were inconclusive for S. mitis clones. A statistically significant positive correlation between MS levels and caries (or future caries) was evident at both visits, but there were no statistical correlations with the growth on pH 5.5 media or media selective for bifidobacteria. CONCLUSIONS: The low pH potential likely varies considerably among oral streptococcal species and is least likely to be found among strains of S. mitis. Accordingly, the concept and constitution of 'low pH streptococci' may need to be re-evaluated.

Sensorimotor control of gait: a novel approach for the study of the interplay of visual and proprioceptive feedback.

Sensorimotor control theories propose that the central nervous system exploits expected sensory consequences generated by motor commands for movement planning, as well as online sensory feedback for comparison with expected sensory feedback for monitoring and correcting, if needed, ongoing motor output. In our study, we tested this theoretical framework by quantifying the functional role of expected vs. actual proprioceptive feedback for planning and regulation of gait in humans. We addressed this question by using a novel methodological approach to deliver fast perturbations of the walking surface stiffness, in conjunction with a virtual reality system that provided visual feedback of upcoming changes of surface stiffness. In the "predictable" experimental condition, we asked subjects to learn associating visual feedback of changes in floor stiffness (sand patch) during locomotion to quantify kinematic and kinetic changes in gait prior to and during the gait cycle. In the "unpredictable" experimental condition, we perturbed floor stiffness at unpredictable instances during the gait to characterize the gait-phase dependent strategies in recovering the locomotor cycle. For the "unpredictable" conditions, visual feedback of changes in floor stiffness was absent or inconsistent with tactile and proprioceptive feedback. The investigation of these perturbation-induced effects on contralateral leg kinematics revealed that visual feedback of upcoming changes in floor stiffness allows for both early (preparatory) and late (post-perturbation) changes in leg kinematics. However, when proprioceptive feedback is not available, the early responses in leg kinematics do not occur while the late responses are preserved although in a, slightly attenuated form. The methods proposed in this study and the preliminary results of the kinematic response of the contralateral leg open new directions for the investigation of the relative role of visual, tactile, and proprioceptive feedback on gait control, with potential implications for designing novel robot-assisted gait rehabilitation approaches.

Sensation seeking, aggression, and reckless behavior in high school students, college students, and adults.

Replicating work of Arnett, males reported more frequent Reckless Behavior than females, and 27 high school and 48 college students did not differ in scores on Sensation Seeking or Aggression. As anticipated by Arnett, the 35 adults had significantly lower Sensation Seeking and Aggression scores than the two younger groups and less Reckless Behavior as well. In contrast to Arnett, Reckless Behavior did not rise for college students, and Sensation Seeking, but not Aggression, correlated with Reckless Behavior in all samples.