Facilitative and Inhibitory Interactions Among Estuarine Meiobenthic Harpacticoid Copepods (Commensalism, Benthos, Louisiana).

In Louisiana, USA, marshes, the harpacticoid copepods Scottolana canadensis and Pseudostenhelia wellsi are community co-dominants with similar lifestyles. Scottolana canadensis is a semi-sessile burrow-dweller capable of subsurface suspension and deposit feeding. Pseudostenhelia wellsi is a semi-sessile tube-building copepod that continuously corkscrews back and forth within its tube and appears to graze on the inner tube walls. Monospecific patches of both species (250 (.) 5cm(\u27-2)) were generated in laboratory microcosms to determine their effects on colonization by two completely errant, burrowing harpacticoids, Nitocra lacustris and Cletocamptus deitersi, that have similar foraging and burrowing behaviors and similar effects on sediment structure. Pseudostenhelia wellsi tube patches facilitated colonization by S. canadensis and N. lacustris, but strongly inhibited colonization by C. deitersi. Scottolana canadensis patches were significantly unattractive to N. lacustris and inhibited their immigration. Mechanisms of facilitation were tested with colonization experiments offering patches of sterile sediments, natural P. wellsi tubes, P. wellsi agar tube mimics, and patches of pure mucin-enriched sediments. These experiments showed that both mucus and inert meiofaunal-sized tube structure act as strong facilitants to N. lacustris copepodites and adults overall. Patch colonization by Nitocra lacustris adult females and S. canadensis copepodites and adults was not facilitated by mucus or tube structure alone, but was strongly facilitated by natural P. wellsi tubes. These experiments demonstrate that species interactions may influence spatial patterns in harpacticoid communities, but assemblages are not consistently predictable based on similarities/dissimilarities in species\u27 functional effects on muddy sediment structure

RURAL VIRGINIA: PROVIDING FOR THE FUTURE THROUGH CHANGING POLICY

Community/Rural/Urban Development,

The Ursinus Weekly, November 29, 1915

Meeting of the Board of Directors • First numbers of lecture course • Ursinus celebrates great naval victory • Varsity insignia awarded • A critical estimate of Pygmalion and incidentally of G. Bernard Shaw • Seminary notes • The football coach and the college professor • Our sociabilities • Clark elected captainhttps://digitalcommons.ursinus.edu/weekly/2608/thumbnail.jp

Catecholborane Reductions of Ditosylhydrozones to the Corresponding Methylene Derivatives

The smooth deoxygenation of diketones via the Catecholborane reduction of the corresponding ditosylhydrzaones is described. The reductions occur under mild conditions and are suitable for sensitive compounds

The Ursinus Weekly, November 22, 1915

Ursinus conquers the Navy 10 to 7 • Meeting of the Advisory Council • Prospects bright for winning team • Thanksgiving • A critical estimate of Pygmalion and incidentally of G. Bernard Shaw • Among the colleges • College directory • Literary societieshttps://digitalcommons.ursinus.edu/weekly/2607/thumbnail.jp

Assessing lifetime stressor exposure in sport performers:Associations with trait stress appraisals, health, well-being, and performance

Research has found that greater lifetime stressor exposure increases the risk for mental and physical health problems. Despite this, few studies have examined how stressors occurring over the entire lifespan affect sport performers’ health, well-being, and performance, partly due to the difficulty of assessing lifetime stressor exposure. To address this issue, we developed a sport-specific stress assessment module (Sport SAM) for the Stress and Adversity Inventory (STRAIN) and then analyzed the instrument’s usability, acceptability, validity, and test-retest reliability. Furthermore, we examined whether trait-like tendencies to appraise stressful situations as a challenge or threat mediated the association between lifetime stressor exposure and health, well-being, and performance. Participants were 395 sport performers (M(age) = 22.50 years, SD = 5.33) who completed an online survey. Results revealed that the Sport SAM demonstrated good usability and acceptability, good concurrent validity in relation to the Adult STRAIN (rs = 0.23 to 0.29), and very good test-retest reliability (r(icc) = 0.87 to 0.89). Furthermore, the Sport SAM was significantly associated with symptoms of depression (β = 0.21 to 0.24, ps ≤ .001) and anxiety (β = 0.13 to 0.19, ps ≤ .012), and general physical (β = 0.24 to 0.27, ps = ≤ 0.001) and mental (β = 0.23 to 0.32, p ≤ .001) health complaints. Finally, we found that associations between total lifetime non-sport and sport-specific stressor severity and health were mediated by trait stress appraisals. Consequently, these findings may help practitioners better identify sport performers who are at risk of developing stress-related health problems