Lichen specific thallus mass and secondary compounds change across a retrogressive fire-driven chronosequence

In the long-term absence of major disturbances ecosystems enter a state of retrogression, which involves declining soil fertility and consequently a reduction in decomposition rates. Recent studies have looked at how plant traits such as specific leaf mass and amounts of secondary compounds respond to declining soil fertility during retrogression, but there are no comparable studies for lichen traits despite increasing recognition of the role that lichens can play in ecosystem processes. We studied a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. We used this system to explore how specific thallus mass (STM) and carbon based secondary compounds (CBSCs) change in three common epiphytic lichen species (Hypogymnia phsyodes, Melanohalea olivacea and Parmelia sulcata) as soil fertility declines during this retrogression. We found that STMs of lichens increased sharply during retrogression, and for all species soil N to P ratio (which increased during retrogression) was a strong predictor of STM. When expressed per unit area, medullary CBSCs in all species and cortical CBSCs in P. sulcata increased during retrogression. Meanwhile, when expressed per unit mass, only cortical CBSCs in H. physodes responded to retrogression, and in the opposite direction. Given that lichen functional traits are likely to be important in driving ecological processes that drive nutrient and carbon cycling in the way that plant functional traits are, the changes that they undergo during retrogression could potentially be significant for the functioning of the ecosystem

Recommendations to the Social Security Administration on the Design of the Mental Health Treatment Study

Many beneficiaries with mental illness who have a strong desire to work nevertheless continue to seek the protection and security of disability benefits, not only because of the income such benefits provide but also for the health care coverage that comes with it. Further complicating matters is that few jobs available to people with mental illnesses have mental health care coverage, forcing individuals to choose between employment and access to care. These barriers, coupled with the limited treatment options and negative employer attitudes and even discrimination when it comes to employing people with serious metal illness, help "explain" the very rates of low labor force participation among people with psychiatric disabilities

Accurate first-derivative nonadiabatic couplings for the H3 system

A conical intersection exists between the ground (1 2 A[prime]) and the first-excited (2 2A[prime]) electronic potential energy surfaces (PESs) of the H3 system for C3v geometries. This intersection induces a geometric phase effect, an important factor in accurate quantum mechanical reactive scattering calculations, which at low energies can be performed using the ground PES only, together with appropriate nuclear motion boundary conditions. At higher energies, however, such calculations require the inclusion of both the 1 2A[prime] and 2 2A[prime] electronic PESs and the corresponding nuclear derivative couplings. Here we present ab initio first-derivative couplings for these states obtained by analytic gradient techniques and a fit to these results. We also present a fit to the corresponding 1 2A[prime] and 2 2A[prime] adiabatic electronic PESs, obtained from the ab initio electronic energies. The first-derivative couplings are compared with their approximate analytical counterparts obtained by Varandas et al. [J. Chem. Phys. 86, 6258 (1987)] using the double many-body expansion method. As expected, the latter are accurate close to conical intersection configurations but not elsewhere. We also present the contour integrals of the ab initio couplings along closed loops around the above-mentioned conical intersection, which contain information about possible interactions between the 2 2A[prime] and 3 2A[prime] states

Mentoring Youth with Emotional and Behavioral Problems: A Meta-Analytic Review

Our current service delivery models are falling short of helping youth with mental health problems. Mentoring is one option that may be effective at helping us address this shortcoming. Youth mentoring theory and research have typically treated mentoring as a prevention intervention (i.e., preventing school dropout, academic decline, psychopathology development, etc.), and research has found youth mentoring to be effective in a variety of domains. The benefits of mentoring may also be applicable to youth with known mental health problems. Research has begun to tackle this question. This meta-analysis addresses the questions of the effectiveness of mentoring programs targeting youth with emotional and behavioral problems and the program characteristics and practices that increase effectiveness. Results indicated a small-to-moderate effect of these specialized mentoring programs across youth outcomes, commensurate with other meta-analyses of intervention effectiveness. Moderator analyses yielded several program characteristics and practices that improve effectiveness, including setting, youths’ gender, and parental involvement, among others. Overall, mentoring programs that target youth with emotional and behavioral problems are viable candidates for serving as alternative or adjunctive interventions to improve the current mental healthcare service delivery system

FIXED POINT THEOREM FOR MULTIVALUED NON-SELF MAPPINGS SATISFYING JS-CONTRACTION WITH AN APPLICATION

In this paper, we present some fixed point results for multivalued non-self mappings. We generalize the fixed point theorem due to Altun and Minak [2] by using Jleli and Sameti [9] $\vartheta$-contraction. To validate the results proved here, we provide an appropriate application of our main result

H. Keith Hunt on Consumer Behavior: Understanding His Contribution

This study uses an ego-centric bibliometric analysis of H. Keith Hunt to elucidate his connection to researchers in the consumer behavior field and his impact on the field. We identified publications written or edited by Hunt using Web of Science, Google Scholar, and the Journal of Consumer Satisfaction, Dissatisfaction and Complaining Behavior; analyzed Hunt’s co-authors and citations in those works; and tabulated Hunt’s co-cited authors for top consumer behavior journals in Web of Science. Based on the analysis and quotes from his works and others about Hunt, we also identify and discuss dimensions related to Hunt’s impact on the consumer behavior field: his scholarly influence; his vision; his leadership; his mentorship; and his role as a head of a community of scholars, teachers, and marketers. Hunt not only developed the field of scholarship around consumer satisfaction, dissatisfaction, and complaining behavior, he fostered a community of scholars known for their collaboration and creativity in expanding the bounds of the consumer behavior field. His mentorship continues to impact the field as others take up his mantle to expand its conceptual development and invite new scholars to the fold

Self-regulation mechanism for charged point defects in hybrid halide perovskites

Hybrid halide perovskites such as methylammonium lead iodide (CH3NH3PbI3) exhibit unusually low free carrier concentrations despite being processed at low-temperatures from solution. We demonstrate, through quantum mechanical calculations, that the origin of this phenomenon is a prevalence of ionic over electronic disorder in stoichiometric materials. Schottky defect formation provides a mechanism to self-regulate the concentration of charge carriers through ionic compensation of charged point defects. The equilibrium charged vacancy concentration is predicted to exceed 0.4% at room temperature. This behaviour, which goes against established defect conventions for inorganic semiconductors, has implications for photovoltaic performance

Multiple Quantum Phases in Graphene with Enhanced Spin-Orbit Coupling: From the Quantum Spin Hall Regime to the Spin Hall Effect and a Robust Metallic State

We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon segregation of thallium adatoms adsorbed onto a graphene surface. Landauer-B\"uttiker and Kubo-Greenwood simulations are used to access both edge and bulk transport physics in disordered thallium-functionalized graphene systems of realistic sizes. Our findings not only quantify the detrimental effects of adatom clustering in the formation of the topological state, but also provide evidence for the emergence of spin accumulation at opposite sample edges driven by spin-dependent scattering induced by thallium islands, which eventually results in a minimum bulk conductivity $\sim 4e^{2}/h$, insensitive to localization effects