Species Abundances Influence the Net Biodiversity Effect in Mixtures of Two Plant Species

Species abundances (evenness or identity of the dominant species in mixtures) usually are not rigorously controlled when testing relationships between plant production and species richness and may be highly dynamic in disturbed or early successional communities. Changes in species abundances may affect the yield of mixtures relative to yields expected from species monocultures [the net biodiversity effect (NBE)] by changing how species that differ in function are distributed in the plant community. To test the prediction that variation in species abundances affects the NBE via changes in the expression of functional differences among species (the complementarity effect), we grew perennial grasses and forbs in field plots in central Texas, USA, as equal-density monocultures and two-species mixtures in which relative abundances of species were varied. Function should differ more consistently between species of different growth forms than of the same growth form. We predicted, therefore, that the complementarity effect and influence of species abundances on the NBE would be more pronounced in grass/forb mixtures than in mixtures with species of the same growth form (grass/grass and forb/forb mixtures). The NBE varied with species evenness in two of the six species pairs studied and with identity of the dominant species in a third species combination. The NBE was sensitive to species proportions in both grass/grass and grass/forb assemblages. In all combinations in which the NBE differed with either evenness or identity of the dominant species, the variation resulted largely from change in the complementarity effect. Our results suggest that the NBE of mixtures is sensitive to effects of species ratios on complementarity

Using a whole person approach to support people with cancer: a longitudinal, mixed methods service evaluation

Introduction: Improved models of care are needed to meet all the support needs of people with cancer, which encompass psychological, emotional, physical, spiritual, sexual, occupational, social and existential needs. The aim of this paper is to (1) evaluate short and long-term impacts of using a whole person approach to support people with cancer on the Living Well with the Impact of Cancer Course (LWC); (2) use these data to inform strategic decisions about future service provision at Penny Brohn UK. Methods: Longitudinal mixed-methods service evaluation (n=135). Data collected included health related quality of life (HRQoL) (FACIT-SpEx); Concerns (types and severity - MYCaW); lifestyle behaviour (bespoke questionnaire) and participants’ experiences over 12 months post course. Results: Statistically and clinically significant improvements from baseline - 12 months in severity of MYCaW Concerns (n=64; p<0.000) and mean total HRQoL (n=66; p<0.000). The majority of MYCaW concerns were ‘psychological and emotional’ and about participants’ wellbeing. Spiritual, emotional and functional wellbeing contributed most to HRQoL improvements at 12 months. Barriers to maintaining healthy lifestyle changes included lack of support from family and friends, time constraints, and returning to work. 3-6 months post-course was identified as the time when more support was most likely to be needed. Conclusions: Using a whole person approach for the LWC enabled the needs of participants to be met, and statistically and clinically significant improvements in HRQoL and MYCaW Concerns were reported. Qualitative data analysis explored how experiencing whole person support enabled participants to make and sustain healthy lifestyle changes associated with improved survivorship. Barriers experienced to making health behaviour change were also identified. These data then informed wider and more person-centred clinical provision to increase the maintenance of positive long-term behaviour changes. Comparison of whole person approaches to cancer treatment and support and standard care are now urgently needed

Service Evaluation of 'Living Well with the Impact of Cancer' Courses

The aim of the Penny Brohn Cancer Care Living Well Service Evaluation was to measure the level of benefit that participants were receiving from the Penny Brohn Cancer Care(PBCC)Living Well course and to inform current and future service provision at PBCC. The Penny Brohn Whole Person Approach model(PB-WPA model), which underpins the Living Well course, was designed to support the ‘whole person’ and the course was intended to meet the needs of people with cancer, as identified by the National Cancer Survivorship Initiative (NCSI). The combined qualitative and quantitative results of the Living Well Service Evaluation have demonstrated, very clearly at times, that participants were highly satisfied with the course. The immediate benefit of attending was measurable, in terms of improved health related quality of life (HRQoL) and improved MYCaW (Measure yourself Concerns and Wellbeing) concerns and wellbeing. The evaluation results show that the Living Well course experience enabled the majority of participants to regain control over many aspects of their life, and to start taking responsibility for their health. The following aspects of the course were identified as the most helpful: -Specific units of ‘education and explanation’ about cancer and why healthy lifestyle changes to areas such as diet, exercise and relaxation are beneficial -Advice and education from medical doctors -The opportunity to share experiences with other participants For some, this empowerment led to long-term changes in exercise, food consumption,use of self-help techniques and the ability to communicate more freely and openly with family, friends and medical professionals. These improvements were reflected in the 12 month outcome data, where a sustained improvement in HRQoL and MYCaW concerns was reported by many clients. Such patient reported outcome measures (PROMs) are limited in what they can measure, thus qualitative data were also collected to ensure that participants were able to share their experiences (positive or negative) of the Living Well course, and their subsequent experiences of applying the education and techniques learnt on the course. A picture emerged that identified difficulties in sustaining lifestyle changes at around the 3-6 month follow-up. Participants who returned to PBCC within the 12 month follow-up period, however, were more likely to benefit by reporting a greater improvement in HRQoL and MYCaW scores, plus an improved understanding of how to make and maintain healthy lifestyle changes to suit their individual circumstances. In regards to the current NCSI priorities, it is hoped that the data reported in this evaluation go some way to informing the following: -Information and support from the point of diagnosis -Managing the consequences of treatment -Promoting recovery -Sustaining recovery -Supporting people with active and advanced disease -Improving survivorship intelligence Finally, this report demonstrates how a patient-centred model of support can be effectively evaluated to provide relevant, practical and evidence-based information to commissioners. Participant satisfaction: Participants were very satisfied with the course content, course delivery and resources provided which often exceeded their needs and expectations. Participant outcomes: The PB-WPA model successfully encompassed and supported all the types of concerns participants arrived with. The most frequently reported participant concerns were psychological and emotional,about their wellbeing and about their physical health. On average, participants experienced statistically and clinically significant improvements in their MYCaW concern and wellbeing scores, and total HRQoL scores,which remained improved over the 12 month follow-up. The aspects of HRQoL that were most likely to improve after attending the Living Well course were spiritual, emotional and functional wellbeing. Supporters had their own profile of concerns, namely psychological and emotional,supporter specific concerns and practical concerns. Concerns were as severely rated as those from participants with a diagnosis of cancer and also showed statistically significant average improvements throughout the 12 month follow-up. The small group of participants with metastatic disease reported significant improvements in their MYCaW concern scores, in line with the whole evaluation group,and a significantly greater improvement in HRQoL over 12 months compared to participants with primary cancer.Participants who returned for more support from PBCC were in more need of support than those who did not return. They were more likely to have poorer HRQoL at baseline and rate their concerns more severely. Participants who returned to PBCC experienced more improvement in HRQoL that was likely to be clinically significant. These participants also had a greater degree of improvement in their MYCaW concerns, compared to non-returners. Over half of the participants experienced new concerns over the 12 month follow-up period. Concerns were most frequently associated with psychological and emotional and physical issues. Furthermore, at 12 months, participants were still experiencing arange of health issues

Monte Carlo Simulation Calculation of Critical Coupling Constant for Continuum \phi^4_2

We perform a Monte Carlo simulation calculation of the critical coupling constant for the continuum {\lambda \over 4} \phi^4_2 theory. The critical coupling constant we obtain is [{\lambda \over \mu^2}]_crit=10.24(3).Comment: 11 pages, 4 figures, LaTe

Free HIV Antiretroviral Therapy Enhances Adherence among Individuals on Stable Treatment: Implications for Potential Shortfalls in Free Antiretroviral Therapy

Objective: To estimate the population-level causal effect of source of payment for HIV medication on treatment adherence using Marginal Structural Models. Methods: Data were obtained from an observational cohort of 76 HIV-infected individuals with at least 24 weeks of antiretroviral therapy treatment from 2002 to 2007 in Kampala, Uganda. Adherence was the primary outcome and it was measured using the 30-day visual analogue scale. Marginal structural models (MSM) were used to estimate the effect of source of payment for HIV medication on adherence, adjusting for confounding by income, duration on antiretroviral therapy (ART), timing of visit, prior adherence, prior CD4+ T cell count and prior plasma HIV RNA. Traditional association models were also examined and the results compared. Results: Free HIV treatment was associated with a 3.8% improvement in adherence in the marginal structural model, while the traditional statistical models showed a 3.1–3.3% improvement in adherence associated with free HIV treatment. Conclusion: Removing a financial barrier to treatment with ART by providing free HIV treatment appears to significantly improve adherence to antiretroviral therapy. With sufficient information on confounders, MSMs can be used to make robust inferences about causal effects in epidemiologic research

The Responsiveness, Content Validity, and Convergent Validity of the Measure Yourself Concerns and Wellbeing (MYCaW) Patient-Reported Outcome Measure

Objective Measure Yourself Concerns and Wellbeing (MYCaW) is a patient-centred questionnaire that allows cancer patients to identify and quantify the severity of their ‘Concerns’ and Wellbeing, as opposed to using a pre-determined list. MYCaW administration is brief and aids in prioritising treatment approaches. Our goal was to assess the convergent validity and responsiveness of MYCaW scores over time, the generalisability of the existing qualitative coding framework in different complementary and integrative healthcare settings and content validity. Methods Baseline and 6-week follow-up data (n=82) from MYCaW and FACIT-SpEx questionnaires were collected for a service evaluation of the ‘Living Well With The Impact of Cancer’ course at Penny Brohn Cancer Care. MYCaW construct validity was determined using Spearman's Rank Correlation test, and responsiveness indices assessed score changes over time. The existing qualitative coding framework was reviewed using a new dataset (n=158) and coverage of concern categories compared to items of existing outcome measures. Results Good correlation between MYCaW and FACIT-SpEx score changes were achieved (r= -0.57, p≥0.01). MYCaW Profile and Concern scores were highly responsive to change: SRM=1.02 and 1.08; effect size=1.26 and 1.22. MYCaW change scores showed the anticipated gradient of change according to clinically relevant degrees of change. Categories including ‘Spirituality’, ‘weight change’ and ‘practical concerns’ were added to the coding framework to improve generalisability. Conclusions MYCaW scores were highly responsive to change, allowing personalized patient outcomes to be quantified; the qualitative coding framework is generalisable across different oncology settings and has broader coverage of patient-identified concerns compared with existing cancer-related patient-reported outcome measures

Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulator

The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn$_{1-x}$In$_{x}$Te), and for low indium contents ($x=0.04$) it is known that the topological surface states are preserved. Here we present the growth, characterization and angle resolved photoemission spectroscopy analysis of samples with much heavier In doping (up to $x\approx0.4$), a regime where the superconducting temperature is increased nearly fourfold. We demonstrate that despite strong p-type doping, Dirac-like surface states persist

The Color--Flavor Transformation of induced QCD

The Zirnbauer's color-flavor transformation is applied to the $U(N_c)$ lattice gauge model, in which the gauge theory is induced by a heavy chiral scalar field sitting on lattice sites. The flavor degrees of freedom can encompass several `generations' of the auxiliary field, and for each generation, remaining indices are associated with the elementary plaquettes touching the lattice site. The effective, color-flavor transformed theory is expressed in terms of gauge singlet matrix fields carried by lattice links. The effective action is analyzed for a hypercubic lattice in arbitrary dimension. We investigate the corresponding d=2 and d=3 dual lattices. The saddle points equations of the model in the large-$N_c$ limit are discussed.Comment: 24 pages, 6 figures, to appear in Int. J. Mod. Phys.

Lifshitz transition and van Hove singularity in a Topological Dirac Semimetal

A topological Dirac semimetal is a novel state of quantum matter which has recently attracted much attention as an apparent 3D version of graphene. In this paper, we report critically important results on the electronic structure of the 3D Dirac semimetal Na3Bi at a surface that reveals its nontrivial groundstate. Our studies, for the first time, reveal that the two 3D Dirac cones go through a topological change in the constant energy contour as a function of the binding energy, featuring a Lifshitz point, which is missing in a strict 3D analog of graphene (in other words Na3Bi is not a true 3D analog of graphene). Our results identify the first example of a band saddle point singularity in 3D Dirac materials. This is in contrast to its 2D analogs such as graphene and the helical Dirac surface states of a topological insulator. The observation of multiple Dirac nodes in Na3Bi connecting via a Lifshitz point along its crystalline rotational axis away from the Kramers point serves as a decisive signature for the symmetry-protected nature of the Dirac semimetal's topological groundstate.Comment: 5 pages, 4 Figures, Related papers on topological Fermi arcs and Weyl Semimetals (WSMs) are at http://physics.princeton.edu/zahidhasangroup/index.htm