Rundown on the Rapa : activity booklet for educators

This booklet provides hands-on classroom activities that can be used to reinforce concepts discussed in Rundown on the Rapa. All booklet activities are tied to middle and high school national science education standards as well as to specific Virginia Math, Life Science, and Biology SOL. The activities encourage problem solving and critical thinking skills. This booklet is intended as a companion to the VORTEX Instructional Booklet RUNDOWN ON THE RAPA. These activities have been designed to help science educators reinforce concepts presented in the RUNDOWN ON THE RAPA Instructional Booklet. See: https://doi.org/10.21220/V5MN1

Predators in action : rapa whelks vs. hard clams

This booklet gives information and data-based exercises describing ecological and economic connections between introduced rapa whelk Rapana venosa predators and local hard clams Mercenaria mercenaria in the lower Chesapeake Bay. The information is focused to answer the question: How many hard clams could a rapa whelk eat in one year

Shellfish stalkers: Threats to an oyster - Activity booklet for educators

This booklet provides hands-on classroom activities that can be used to reinforce concepts presented in Shellfish Stalkers: Threats to an Oyster. The activities encourage problem solving and critical thinking skills

Shellfish stalkers: Threats to an oyster

Describes some of the sources of mortality for Chesapeake Bay oysters. Common oyster predators, diseases, and habitat requirements are described with specific attention given to Virginia estuaries

Rundown on the Rapa

Explains what rapa whelks are, where they came from, and why they are of concern in the Chesapeake Bay ecosystem. The booklet describes ways to identify rapa whelks in relation to local whelks, compares rapa whelk egg masses with those laid by local whelks, and examines life history traits of the rapa whelk that make it a successful invader

Identifying scoliosis in population-based cohorts:automation of a validated method based on total body dual energy X-ray absorptiometry scans

Scoliosis is a 3D-torsional rotation of the spine, but risk factors for initiation and progression are little understood. Research is hampered by lack of population-based research since radiographs cannot be performed on entire populations due to the relatively high levels of ionising radiation. Hence we have developed and validated a manual method for identifying scoliosis from total body dual energy X-ray absorptiometry (DXA) scans for research purposes. However, to allow full utilisation of population-based research cohorts, this needs to be automated. The purpose of this study was therefore to automate the identification of spinal curvature from total body DXA scans using machine learning techniques. To validate the automation, we assessed: (1) sensitivity, specificity and area under the receiver operator curve value (AUC) by comparison with 12,000 manually annotated images; (2) reliability by rerunning the automation on a subset of DXA scans repeated 2–6 weeks apart and calculating the kappa statistic; (3) validity by applying the automation to 5000 non-annotated images to assess associations with epidemiological variables. The final automated model had a sensitivity of 86.5%, specificity of 96.9% and an AUC of 0.80 (95%CI 0.74–0.87). There was almost perfect agreement of identification of those with scoliosis (kappa 0.90). Those with scoliosis identified by the automated model showed similar associations with gender, ethnicity, socioeconomic status, BMI and lean mass to previous literature. In conclusion, we have developed an accurate and valid automated method for identifying and quantifying spinal curvature from total body DXA scans

Gamma Ray Bursts from the Evolved Galactic Nuclei

A new cosmological scenario for the origin of gamma ray bursts (GRBs) is proposed. In our scenario, a highly evolved central core in the dense galactic nucleus is formed containing a subsystem of compact stellar remnants (CSRs), such as neutron stars and black holes. Those subsystems result from the dynamical evolution of dense central stellar clusters in the galactic nuclei through merging of stars, thereby forming (as has been realized by many authors) the short-living massive stars and then CSRs. We estimate the rate of random CSR collisions in the evolved galactic nuclei by taking into account, similar to Quinlan & Shapiro (1987), the dissipative encounters of CSRs, mainly due to radiative losses of gravitational waves, which results in the formation of intermediate short-living binaries, with further coalescence of the companions to produce GRBs. We also consider how the possible presence of a central supermassive black hole, formed in a highly evolved galactic nucleus, influences the CSR binary formation. This scenario does not postulate ad hoc a required number of tight binary neutron stars in the galaxies. Instead, it gives, for the most realistic parameters of the evolved nuclei, the expected rate of GRBs consistent with the observed one, thereby explaining the GRB appearance in a natural way of the dynamical evolution of galactic nuclei. In addition, this scenario provides an opportunity for a cosmological GRB recurrence, previously considered to be a distinctive feature of GRBs of a local origin only. We also discuss some other observational tests of the proposed scenario.Comment: 25 pages, LATEX, uses aasms4.sty, accepted by Ap

Does cultural integration explain a mental health advantage for adolescents?

BACKGROUND: A mental health advantage has been observed among adolescents in urban areas. This prospective study tests whether cultural integration measured by cross-cultural friendships explains a mental health advantage for adolescents. METHODS: A prospective cohort of adolescents was recruited from 51 secondary schools in 10 London boroughs. Cultural identity was assessed by friendship choices within and across ethnic groups. Cultural integration is one of four categories of cultural identity. Using gender-specific linear-mixed models we tested whether cultural integration explained a mental health advantage, and whether gender and age were influential. Demographic and other relevant factors, such as ethnic group, socio-economic status, family structure, parenting styles and perceived racism were also measured and entered into the models. Mental health was measured by the Strengths and Difficulties Questionnaire as a 'total difficulties score' and by classification as a 'probable clinical case'. RESULTS: A total of 6643 pupils in first and second years of secondary school (ages 11-13 years) took part in the baseline survey (2003/04) and 4785 took part in the follow-up survey in 2005-06. Overall mental health improved with age, more so in male rather than female students. Cultural integration (friendships with own and other ethnic groups) was associated with the lowest levels of mental health problems especially among male students. This effect was sustained irrespective of age, ethnicity and other potential explanatory variables. There was a mental health advantage among specific ethnic groups: Black Caribbean and Black African male students (Nigerian/Ghanaian origin) and female Indian students. This was not fully explained by cultural integration, although cultural integration was independently associated with better mental health. CONCLUSIONS: Cultural integration was associated with better mental health, independent of the mental health advantage found among specific ethnic groups: Black Caribbean and some Black African male students and female Indian students