Assessing the influence of silvicultural practices on Douglas-fir nutrition and stemwood production

Nitrogen, phosphorus and sulfur concentrations were measured in the soil, foliage and litter of Douglas-fir growing in pure Douglas-fir and mixed conifer stands. On four sites of contrasting fertility and climatic conditions, plots had been modified by the introduction of alder, thinning, or by a single application of nitrogen fertilizer and thinning. Samples were taken to look for differences between plots in soil, foliage and litter nutrient concentrations arid ratios. Changes in canopy leaf area and wood production efficiency. were calculated from estimates of stemwood diameter and sapwood area. Wood production efficiency, an index of stemwood production per unit of leaf area, remained steady or increased under all treatments, despite shading from higher canopy leaf areas. On the less fertile Washington and Vancouver Island sites, the alder/conifer plots, with higher concentration up to a certain 'threshold level', above which higher nitrogen concentrations did not increase wood production as significantly. Stemwood production also tended to increase with higher N:P ratios and then leveled off above a ratio of twelve. A nitrogen use efficiency was calculated as the amount of stemwood produced per unit of N in the foliage. Although higher foliar nitrogen values correlated with higher wood production/m2 on the poorer quality sites, the nutrient use efficiency tended to be lower when the nitrogen concentration per m2 was more than about three grams per m2. Stemwood production per m2 of foliage tended to increase with higher foliar N:P ratios, but the correlation coefficient was low. Soil N (mineralizable and total) plotted against against foliar N/m2 produced a coefficient of .7. Oregon coast site data alone showed a significant correlation between foliar N and percent N retranslocation (r = .94) and between foliar P and percent P retranslocation (r = .91)

A consistent scalar-tensor cosmology for inflation, dark energy and the Hubble parameter

The authors are grateful for financial support to the Cruickshank Trust (CW), EPSRC/GG-Top (CW, JR), Omani Government (MA), Science Without Borders programme, CNPq, Brazil (DR), and STFC/CfFP (CW, AM, RB, JM). CW and AM acknowledge the hospitality of CERN, where this work was started. The University of Aberdeen and University of Edinburgh are charitable bodies registered in Scotland, with respective registration numbers SC013683 and SC005336.Peer reviewedPostprin

A Spectroscopic Survey of a Sample of Active M Dwarfs

A moderate resolution spectroscopic survey of Fleming's sample of 54 X-ray selected M dwarfs with photometric distances less than 25 pc is presented. Radial and rotation velocities have been measured by fits to the H-alpha profiles. Radial velocities have been measured by cross correlation. Artificial broadening of an observed spectrum has produced a relationship between H-alpha FWHM and rotation speed, which we use to infer rotation speeds for the entire sample by measurement of the H-alpha emission line. We find 3 ultra-fast rotators (UFRs, vsini > 100km/s), and 8 stars with 30 < vsini < 100 km/s. The UFRs have variable emission. Cross-correlation velocities measured for ultra-fast rotators (UFRs) are shown to depend on rotation speed and the filtering used. The radial velocity dispersion of the sample is 17 km/s. A new double emission line spectroscopic binary with a period of 3.55 days has been discovered, and another known one is in the sample. Three other objects are suspected spectroscopic binaries, and at least six are visual doubles. The only star in the sample observed to have significant lithium is a known TW Hya Association member, TWA 8A. These results show that there are a number of young (< 10^8 yr) and very young (< 10^7 yr) low mass stars in the immediate solar neighbourhood. The H-alpha activity strength does not depend on rotation speed. Our fast rotators are less luminous than similarly fast rotators in the Pleiades. They are either younger than the Pleiades, or gained angular momentum in a different way.Comment: 38 pages incl. 14 figures and 4 tables, plus 12 pages of table for electronic journal only; LaTeX, aastex.cls. Accepted 07/18/02 for publication in The Astronomical Journa

The Acceptability and Feasibility of Implementing a Bio-Behavioral Enhanced Surveillance Tool for Sexually Transmitted Infections in England: Mixed-Methods Study.

BACKGROUND: Sexually transmitted infection (STI) surveillance is vital for tracking the scale and pattern of epidemics; however, it often lacks data on the underlying drivers of STIs. OBJECTIVE: This study aimed to assess the acceptability and feasibility of implementing a bio-behavioral enhanced surveillance tool, comprising a self-administered Web-based survey among sexual health clinic attendees, as well as linking this to their electronic health records (EHR) held in England's national STI surveillance system. METHODS: Staff from 19 purposively selected sexual health clinics across England and men who have sex with men and black Caribbeans, because of high STI burden among these groups, were interviewed to assess the acceptability of the proposed bio-behavioral enhanced surveillance tool. Subsequently, sexual health clinic staff invited all attendees to complete a Web-based survey on drivers of STI risk using a study tablet or participants' own digital device. They recorded the number of attendees invited and participants' clinic numbers, which were used to link survey data to the EHR. Participants' online consent was obtained, separately for survey participation and linkage. In postimplementation phase, sexual health clinic staff were reinterviewed to assess the feasibility of implementing the bio-behavioral enhanced surveillance tool. Acceptability and feasibility of implementing the bio-behavioral enhanced surveillance tool were assessed by analyzing these qualitative and quantitative data. RESULTS: Prior to implementation of the bio-behavioral enhanced surveillance tool, sexual health clinic staff and attendees emphasized the importance of free internet/Wi-Fi access, confidentiality, and anonymity for increasing the acceptability of the bio-behavioral enhanced surveillance tool among attendees. Implementation of the bio-behavioral enhanced surveillance tool across sexual health clinics varied considerably and was influenced by sexual health clinics' culture of prioritization of research and innovation and availability of resources for implementing the surveys. Of the 7367 attendees invited, 85.28% (6283) agreed to participate. Of these, 72.97% (4585/6283) consented to participate in the survey, and 70.62% (4437/6283) were eligible and completed it. Of these, 91.19% (4046/4437) consented to EHR linkage, which did not differ by age or gender but was higher among gay/bisexual men than heterosexual men (95.50%, 722/756 vs 88.31%, 1073/1215; P<.003) and lower among black Caribbeans than white participants (87.25%, 568/651 vs 93.89%, 2181/2323; P<.002). Linkage was achieved for 88.88% (3596/4046) of consenting participants. CONCLUSIONS: Implementing a bio-behavioral enhanced surveillance tool in sexual health clinics was feasible and acceptable to staff and groups at STI risk; however, ensuring participants' confidentiality and anonymity and availability of resources is vital. Bio-behavioral enhanced surveillance tools could enable timely collection of detailed behavioral data for effective commissioning of sexual health services

Characteristics and sexual health service use of MSM engaging in chemsex: results from a large online survey in England.

BACKGROUND: Chemsex, the use of select psychoactive drugs to enhance sexual experience, typically among men who have sex with men (MSM), is associated with sexual behaviours with higher STI risk. Understanding patterns of chemsex among MSM as well as the characteristics and sexual health service engagement of chemsex participants is important for developing interventions. METHODS: Between 5/2016 to 5/2017, 3933 MSM completed an online survey, recruited in sexual health clinics (SHCs) in England (n=421) and via four social networking/dating apps (n=3512). We described patterns of chemsex in the past year and used multivariable logistic regression to investigate differences in demographics and sexual behaviours by chemsex history. We described history of SHC attendance and STI test in the past year among app-recruited chemsex participants. RESULTS: Chemsex in the past year was reported by 10% of respondents; 19% of SHC-recruited and 9% of app-recruited. Among chemsex participants, 74% had used ≥2 chemsex drugs. In the multivariable model, MSM engaging in chemsex had a raised odds of being HIV-positive (adjusted OR (aOR): 3.6; 95% CI 2.1 to 6.1), aged 30-44 (aOR 1.5 vs <30 years; 95% CI 1.0 to 2.1), being born outside the UK and having engaged in higher risk sexual behaviours in the past 3 months. Chemsex participants also had higher odds of condomless anal sex with partners of different or unknown HIV status, but only among HIV-negative/untested. In the past year, 66% of app-recruited chemsex participants had attended a SHC and 81% had had an STI test. CONCLUSION: One in 10 MSM recruited through community and clinical settings across England had engaged in chemsex in the past year. Those that did appear to be at greater STI risk but engaged more actively with sexual health services. This highlights the need and opportunity for chemsex-related services in SHCs and robust referral pathways to drug treatment services

Navigating Digital Ethics for Rural Research : Guidelines and recommendations for researchers and administrators of social media groups

This document was produced as a deliverable of the research project “Navigating Digital Ethics for Rural Research: Guidelines and recommendations for researchers and administrators of social media groups” (DigiEthics). Digiethics is a transdisciplinary project seeking to advance digital ethics by co-designing guidelines for engaging Facebook groups. This project was funded by the by the British Academy Early Career Research Network Scotland Hub Seed Fund 2023. This document is available online with background information at: https://www.hutton.ac.uk/research/ projects/digiethics-navigating-digital-ethics-rural-research If you have read/used this document and you have any comments or feedback you would like to share with us, we would love to hear from you. Please contact [email protected] PD

Long-term dietary compensation for added sugar : effects of supplementary sucrose drinks over a 4-week period

The long-term physiological effects of refined carbohydrates on appetite and mood remain unclear. Reported effects when subjects are not blind may be due to expectations and have rarely been studied for more than 24 h. The present study compared the effects of supplementary soft drinks added to the diet over 4 weeks on dietary intake, mood and BMI in normal-weight women (n 133). Subjects were categorised as 'watchers' or 'non-watchers' of what they ate then received sucrose or artificially sweetened drinks (4 250 ml per d). Expectancies were varied by labelling drinks 'sugar' or 'diet' in a counter-balanced design. Sucrose supplements provided 1800 kJ per d and sweetener supplements provided 67 kJ per d. Food intake was measured with a 7 d diary and mood with ten single Likert scales. By 4 weeks, sucrose supplements significantly reduced total carbohydrate intake (F(1,129) = 5381; P &lt; 0001), fat (F(2,250) = 3333; P &lt; 0001) and protein intake (F(2,250) = 2804; P &lt; 0001) compared with sweetener supplements. Mean daily energy intake increased by just under 1000 kJ compared with baseline (t (67 df) = 382; P &lt; 0001) and was associated with a non-significant trend for those receiving sucrose to gain weight. There were no effects on appetite or mood. Neither dietary restraint status as measured by the Dutch Eating Behaviour Questionnaire nor the expectancy procedure had effects. Expectancies influenced mood only during baseline week. It is concluded that sucrose satiates, rather than stimulates, appetite or negative mood in normal-weight subjects.div_PaS97pub245pub

Cost effectiveness analysis of clinically driven versus routine laboratory monitoring of antiretroviral therapy in Uganda and Zimbabwe.

BACKGROUND: Despite funding constraints for treatment programmes in Africa, the costs and economic consequences of routine laboratory monitoring for efficacy and toxicity of antiretroviral therapy (ART) have rarely been evaluated. METHODS: Cost-effectiveness analysis was conducted in the DART trial (ISRCTN13968779). Adults in Uganda/Zimbabwe starting ART were randomised to clinically-driven monitoring (CDM) or laboratory and clinical monitoring (LCM); individual patient data on healthcare resource utilisation and outcomes were valued with primary economic costs and utilities. Total costs of first/second-line ART, routine 12-weekly CD4 and biochemistry/haematology tests, additional diagnostic investigations, clinic visits, concomitant medications and hospitalisations were considered from the public healthcare sector perspective. A Markov model was used to extrapolate costs and benefits 20 years beyond the trial. RESULTS: 3316 (1660LCM;1656CDM) symptomatic, immunosuppressed ART-naive adults (median (IQR) age 37 (32,42); CD4 86 (31,139) cells/mm(3)) were followed for median 4.9 years. LCM had a mean 0.112 year (41 days) survival benefit at an additional mean cost of $765 [95$7386 [3277,dominated] per life-year gained and $7793 [4442,39179] per quality-adjusted life year gained. Routine toxicity tests were prominent cost-drivers and had no benefit. With 12-weekly CD4 monitoring from year 2 on ART, low-cost second-line ART, but without toxicity monitoring, CD4 test costs need to fall below$3.78 to become cost-effective (<3xper-capita GDP, following WHO benchmarks). CD4 monitoring at current costs as undertaken in DART was not cost-effective in the long-term. CONCLUSIONS: There is no rationale for routine toxicity monitoring, which did not affect outcomes and was costly. Even though beneficial, there is little justification for routine 12-weekly CD4 monitoring of ART at current test costs in low-income African countries. CD4 monitoring, restricted to the second year on ART onwards, could be cost-effective with lower cost second-line therapy and development of a cheaper, ideally point-of-care, CD4 test