Consequences of Fragment for Woody Plant Communities: A Study of Reservoir Islands

Forest fragmentation has been overwhelmingly cited as a major threat to the biodiversity and conservation of forested plant communities worldwide. Here I take a community- and species-specific approach to examine how species richness and composition respond to forest fragmentation. I conducted this research on a series of 35 small forested islands that were fragments of continuous forest created by impoundment of the Savannah River in the Southeastern Piedmont of the United States. I paired the islands with 10 mainland forest sites representing large remnant forest with only a single edge exposed along two reservoirs. Species richness was positively related to island area, as predicted by the species-area relationship, and islands in general had greater species richness than mainland sites because of an addition of liana and shrub species uncommon to oak-hickory forests. Due to the increase of lianas, shrubs and pioneer trees in small forested fragments I detected large differences in the plant communities that have developed on these sites over the last 40 to 70 years. In addition, it appears that islands will continue to diverge from mainland forest over time, likely degrading to the point that the species of oak-hickory forest may disappear and convert entirely to disturbance-tolerant early seral communities. Moreover, these fragments had invasive plants species that were less common in the more intact forest. I used a seedling outplanting experiment to determine if two of the more common, non-native woody invaders are likely to invade intact forest interior sites. Indeed, the non-native woody liana, Lonicera japonica appears to have the ability to not only survive, but also thrive under interior forest. In contrast, Albizia julibrissin does not appear to be a major threat to forest interiors unless there is a large canopy disturbance that increases light to seedlings. Finally, I used this study system to test whether species richness estimators provide accurate estimates and should continue to be used to examine important ecological patterns. I found that all 10 of the ones examined were so imprecise that none of them detected the true species-area relationship found across the forest fragments. Use of species richness estimators, in place of true richness, should therefore be used with extreme caution if the goal is to describe patterns in species richness across a set of sites. Overall, my research highlights how much we still have yet to learn about generalities associated with forest fragmentation and species richness estimation techniques

Significance of soil organic phosphorus to plant growth

The first indication that soils contain organic phosphorus was obtained in 1844 by Mulder (20), in experiments wherein he could not obtain phosphorus-free preparations of certain soil organic matter fractions. Since the time of Mulder, a number of investigations have dealt specifically with the problem of soil organic phosphorus, and it is now generally recognized that a portion of the soil phosphorus occurs in organic forms. The distribution of organic phosphorus in different soil types and groups has been investigated in only a preliminary way, but it has become apparent that the quantities of organic phosphorus are correlated with the quantities of soil organic matter. In Iowa and other North Central states, there are extensive areas of soils that contain relatively large quantities of both substances

Understanding the relationship between co-occurring PTSD and MDD: Symptom severity and affect

How to best understand theoretically the nature of the relationship between co-occurring PTSD and MDD (PTSD+MDD) is unclear. In a sample of 173 individuals with chronic PTSD, we examined whether the data were more consistent with current co-occurring MDD as a separate construct or as a marker of posttraumatic stress severity, and whether the relationship between PTSD and MDD is a function of shared symptom clusters and affect components. Results showed that the more severe depressive symptoms found in PTSD+MDD as compared to PTSD remained after controlling for PTSD symptom severity. Additionally, depressive symptom severity significantly predicted co-occurring MDD even when controlling for PTSD severity. In comparison to PTSD, PTSD+MDD had elevated dysphoria and re-experiencing – but not avoidance and hyperarousal – PTSD symptom cluster scores, higher levels of negative affect, and lower levels of positive affect. These findings provide support for PTSD and MDD as two distinct constructs with overlapping distress components

The Influence of Health Literacy on Reach, Retention, and Success in a Worksite Weight Loss Program

To examine if employee health literacy (HL) status moderated reach, retention, and weight outcomes in a worksite weight loss program

Who participates in internet-based worksite weight loss programs?

<p>Abstract</p> <p>Background</p> <p>The reach and representativeness are seldom examined in worksite weight loss studies. This paper describes and illustrates a method for directly assessing the reach and representativeness of a internet-based worksite weight loss program.</p> <p>Methods</p> <p>A brief health survey (BHS) was administered, between January 2008 and November 2009, to employees at 19 worksites in Southwest Virginia. The BHS included demographic, behavioral, and health questions. All employees were blinded to the existence of a future weight loss program until the completion of the BHS.</p> <p>Results</p> <p>The BHS has a participation rate of 66 percent and the subsequent weight loss program has a participation rate of 30 percent. Employees from higher income households, with higher education levels and health literacy proficiency were significantly more likely to participate in the program (p's < .01).</p> <p>Conclusions</p> <p>Worksite weight loss programs should include targeted marketing strategies to engage employees with lower income, education, and health literacy.</p

Lattice deformation at the sub-micron scale: X-ray nanobeam measurements of elastic strain in electron shuttling devices

The lattice strain induced by metallic electrodes can impair the functionality of advanced quantum devices operating with electron or hole spins. Here we investigate the deformation induced by CMOS-manufactured titanium nitride electrodes on the lattice of a buried, 10 nm-thick Si/SiGe Quantum Well by means of nanobeam Scanning X-ray Diffraction Microscopy. We were able to measure TiN electrode-induced local modulations of the strain tensor components in the range of $2 - 8 \times 10^{-4}$ with ~60 nm lateral resolution. We have evaluated that these strain fluctuations are reflected into local modulations of the potential of the conduction band minimum larger than 2 meV, which is close to the orbital energy of an electrostatic quantum dot. We observe that the sign of the strain modulations at a given depth of the quantum well layer depends on the lateral dimensions of the electrodes. Since our work explores the impact of device geometry on the strain-induced energy landscape, it enables further optimization of the design of scaled CMOS-processed quantum devices.Comment: 16 pages, 6 figure

Integrating the promotion of physical activity within a smoking cessation programme: Findings from collaborative action research in UK Stop Smoking Services

Background: Within the framework of collaborative action research, the aim was to explore the feasibility of developing and embedding physical activity promotion as a smoking cessation aid within UK 6/7-week National Health Service (NHS) Stop Smoking Services. Methods: In Phase 1 three initial cycles of collaborative action research (observation, reflection, planning, implementation and re-evaluation), in an urban Stop Smoking Service, led to the development of an integrated intervention in which physical activity was promoted as a cessation aid, with the support of a theoretically based self-help guide, and self monitoring using pedometers. In Phase 2 advisors underwent training and offered the intervention, and changes in physical activity promoting behaviour and beliefs were monitored. Also, changes in clients’ stage of readiness to use physical activity as a cessation aid, physical activity beliefs and behaviour and physical activity levels were assessed, among those who attended the clinic at 4-week post-quit. Qualitative data were collected, in the form of clinic observation, informal interviews with advisors and field notes. Results: The integrated intervention emerged through cycles of collaboration as something quite different to previous practice. Based on field notes, there were many positive elements associated with the integrated intervention in Phase 2. Self-reported advisors’ physical activity promoting behaviour increased as a result of training and adapting to the intervention. There was a significant advancement in clients’ stage of readiness to use physical activity as a smoking cessation aid. Conclusions: Collaboration with advisors was key in ensuring that a feasible intervention was developed as an aid to smoking cessation. There is scope to further develop tailored support to increasing physical activity and smoking cessation, mediated through changes in perceptions about the benefits of, and confidence to do physical activity

Patterns of therapeutic alliance: Rupture–repair episodes in prolonged exposure for posttraumatic stress disorder.

To better understand the role of therapeutic alliance in PTSD treatment, we examined patterns of and shifts in alliance. First, we identified individuals with repaired ruptures, unrepaired ruptures, and no ruptures in alliance. Then, we explored group differences in these alliance events for clients with common clinical correlates (i.e., co-occurring depression and childhood abuse history) and whether or not the presence of these events influenced treatment outcome