Functional traits of expanding, thicket-forming shrubs: contrasting strategies between exotic and native species

Woody expansion has been documented for decades in many different systems globally, often yielding vast changes in ecosystem functioning. While causes and consequences of woody expansion have been well documented, few studies have addressed plant functional traits that promote dramatic and rapid expansion in range. Our objectives were to investigate plant functional traits that contribute to the colonization, rapid expansion, and thicket formation of an invasive, N-fixing shrub, Elaeagnus umbellata Thunb. (Elaeagnaceae), and a native, N-fixing shrub Morella cerifera (L.) Small (Myricaceae) and compare to native, sympatric, non-expanding shrub species. Quantified functional traits included morphological (e.g., specific leaf area, leaf area) and physiological characteristics (e.g., electron transport rate, hydraulic conductivity) and were linked to two primary resources: light and water, which directly influence plant growth. Elaeagnus umbellata and M. cerifera rely on different strategies to maximize carbon gain, yet resulting physiological efficiency is similar. Elaeagnus umbellata invests a substantial amount of energy into growth during a short amount of time (i.e., deciduous growing season), using an acquisitive trait strategy to outcompete co-occurring woody species, while M. cerifera is productive year-round and uses a combination of conservative and acquisitive traits to outcompete co-occurring woody species. The majority of quantified functional traits of E. umbellata and several of M. cerifera are indicative of efficient light capture, utilization, and internal water movement. These factors contribute to rapid range expansion and thicket formation by promoting enhanced productivity while simultaneously inhibiting colonization and expansion of co-occurring species. Suites of functional traits are important for expansive success and thicket formation, yet differences in functional traits represent alternative strategies for colonization, rapid expansion, and thicketization

Relative rates of sand transport through an incipient parabolic dune at Pinery Provincial Park, Ontario (Ammophila breviligulata, Calamovilfa longifolia, Cakile edentula, Juniperus virginiana, Populus deltoides)

Factors controlling the development, migration, and stability of an incipient parabolic dune in Pinery Provincial Park, Ontario were investigated in terms of grain size characteristics, rates of sediment transport, and local and regional winds. The parabolic dune, situated approximately 60 meters inland of Lake Huron, is dominated by sparsely scattered dune grass species of marram grass (Ammophila breviligulata), sand reed (Calamovilfa longifolia), and sea rocket (Cakile edentula). Small tree species of red cedar (Juniperus virginiana) and eastern cottonwood (Populus deltoides) emerge and increase in number beyond the parabolic dune. Mean grain sizes along a profile were coarsest on the beach and interdunal area, and finest through the foredune and the parabolic dune, which was to be expected. The primary depositional processes responsible for the evolution of the dune is grainfall through vegetation, with intermittent, short periods of tractional deposition. The annual resultant wind vector by frequency is from the east-southwest at 102˚, when all winds were considered, and 117˚ with the effects of onshore winds only. There is no general agreement between the vector resultants calculated and the actual measured dune orientation, which is approximately 190˚. Sand trap samples revealed that twice as much sand was transported through the interior of the dune (55.5 kg), than at the mouth (22.8 kg), over a one year period. Transport through the mouth exhibited greater directional variability than the interior, where transport was dominated by a landward, northerly trend. Overall, the amount of sand transported did increase as mean wind speed increased, with the exception of April. Seasonally, transport through the interior reached a maximum during the spring/early summer, decreased through late summer and fall, until it reached a minimum during winter. Transport through the mouth reached its maximum during the late summer/fall season, declined during the winter, and maintained a relatively constant low from the winter though the spring/early summer season

Identifying Opportunities for Collaboration Across the Social Sciences to Reach the 10-10-10: A Multilevel Approach.

BACKGROUND:The national and global strategy to combat HIV, often referred to as the "90-90-90," aims to diagnose 90% of people living with HIV, get 90% of those diagnosed onto antiretroviral treatment (ART), and achieve viral suppression in 90% of those on ART. The remaining 10-10-10 who will be undiagnosed, not on ART, or not virally suppressed, include vulnerable persons and populations most affected by social determinants of health. Given their foci on the social determinants of health at the individual, social, and structural levels, social scientists are in a prime position to help reach the 10-10-10. A potentially effective way for social scientists to achieve this goal is to examine the issues that affect the 10-10-10 using a multilevel framework, to understand at what levels their own approaches fit within such a multilevel framework, and to seek intentional collaborations with other social scientists who may work at different levels but whose approaches may complement their own within multilevel collaborations. APPROACH:The present article describes how a multilevel framework can guide collaboration across disciplines within the social sciences toward the common goal of reaching the 10-10-10. CONCLUSIONS:Within a multilevel framework, social scientists can work collaboratively to address the needs of individuals among the 10-10-10 within the social and structural contexts (eg, social norms, stigma, poverty, and barriers to care) that affect their health. Such an approach draws on the unique strengths and approaches of different social-science disciplines while also building capacity for individuals most affected by social determinants of health

Peer Intervention To Increase Physical Activity Among Working Women

Most Americans do not engage in enough healthy physical activity (PA), with working women particularly at-risk for inactivity. Workplace PA interventions have been effective, however studies using peers as the central theoretical strategy, have not been found. Social cognitive theory and social comparison theory were used to develop a peer-modeling workplace PA intervention. The aims of this experimental, two-group, preliminary study were: 1) assess intervention feasibility, 2) determine the intervention effect on cardiorespiratory fitness (primary outcome), and PA behavior, cardiovascular risk, self-efficacy, motivation, and social comparison, and 3) describe participant perceptions of the intervention using qualitative focus-group data. Female employees from a health system were randomized to either an attention control group (ACG) or an intervention group (IG). The ACG (n = 26) received general health information. The IG (n = 26) participated in six group sessions with a peer-model, received an exercise prescription, and PA information. Measures at baseline and 12-weeks were: PA (ActiGraph), VO2max (cycle ergometer), resting heart rate, glucose, lipids, and cardiovascular risk score. Using hierarchical linear modeling, no significant group by time effects were found. Although PA increased in both groups (F [df = 1] = 11.4, p = .002), the IG had greater improvements in measures of fitness and cardiovascular risk compared to the ACG. Both groups decreased in self-efficacy while motivation remained stable. The IG group increased in all measures of social comparison while the ACG dropped in comparisons of ability, opinions, modeling, and future-self. Focus-group data indicated peer-models were perceived to be credible, informative, and motivating. The intervention could be expanded to include more peer-model interaction and nutritional content. These findings support testing the intervention with a fully-powered study

Attitudes Toward Suicide, Mental Health, and Help-Seeking Behavior Among African Immigrants: An Ecological Perspective

The population of Africans in the United States is growing, yet little is known about the impact of migration on the attitudes of African immigrants toward suicide, mental health, and helpseeking behavior. Migration entails movement from one cultural environment to another, and the process requires adaptation to the host country. According to Ecological Theory, interactions between the societal structures, values, and beliefs of the host country, cultural values from the country of origin, and individual-level characteristics may affect mental health-related attitudes and behaviors. As such, the current study used mixed methods, administered via online survey, to investigate socio-cultural predictors of attitudes toward suicide, mental health, and treatment seeking among African immigrants in the United States. In the current study the responses of 227 participants were used for qualitative analyses, and responses from 168 participants were used for quantitative analyses. Qualitative results indicated overall negative attitudes towards suicide and positive attitudes towards suicide prevention. Perceived culture-specific causes of suicide included acculturation difficulties, immigration stress, social causes such as home sickness discrimination, and racism, financial causes such as responsibility to kin in Africa, spiritual causes, and deportation risk. Results from quantitative analyses indicated that identification with African values and behaviors were related to lower levels of anxiety, depression, stress, and culture oriented psychological distress. Higher levels of spirituality and religiousness were associated with a negative attitude toward suicide. Implications for population based suicide prevention efforts for African immigrants and for mental health professionals working with African immigrants are discussed

The Impact of Whole Family Foster Care on Social Support Networks

This exploratory study examined the impact of a whole family foster care program on the social support networks of parents placed in care. Comparisons of networks of five parents before and during placement were made. The results suggest that a possible relationship exists on the amount of support received. Increases in network size, concrete, informational and emotional support, reciprocity of help, and the amount of contacts were reported by parents during placement in the program. The overall percentage of criticalness decreased during placement. This suggests an improvement in the quality of social support networks during placement in whole family foster care. Recommendations for social support network building for parents and foster provider skills are included. These findings can be used to guide policy, planning and practice decisions in agencies implementing whole family foster care services