Mycorrhizal co-invasion and novel interactions depend on neighborhood context

© 2015 by the Ecological Society of America. Biological invasions are a rapidly increasing driver of global change, yet fundamental gaps remain in our understanding of the factors determining the success or extent of invasions. For example, although most woody plant species depend on belowground mutualists such as mycorrhizal fungi and nitrogen-fixing bacteria, the relative importance of these mutualisms in conferring invasion success is unresolved. Here, we describe how neighborhood context (identity of nearby tree species) affects the formation of belowground ectomycorrhizal partnerships between fungi and seedlings of a widespread invasive tree species, Pseudotsuga menziesii (Douglas-fir), in New Zealand.We found that the formation of mycorrhizal partnerships, the composition of the fungal species involved in these partnerships, and the origin of the fungi (co-invading or native to New Zealand) all depend on neighborhood context. Our data suggest that nearby ectomycorrhizal host trees act as both a reservoir of fungal inoculum and a carbon source for late-successional and native fungi. By facilitating mycorrhization of P. menziesii seedlings, adult trees may alleviate mycorrhizal limitation at the P. menziesii invasion front. These results highlight the importance of studying biological invasions across multiple ecological settings to understand establishment success and invasion speed

Efficacy of a lay health worker led group antiretroviral medication adherence training among non-adherent HIV-positive patients in KwaZulu-Natal, South Africa: Results from a randomized trial

There is a lack of theory-based randomized controlled trials to examine the effect of antiretroviral adherence in sub-Saharan Africa. We assessed the effectiveness of a lay health worker lead structured group intervention to improve adherence to antiretroviral therapy (ART) in a cohort of HIV-infected adults. This two-arm randomized controlled trial was undertaken at an HIV clinic in a district hospital in South Africa. A total of 152 adult patients on ART and with adherence problems were randomized 1:1 to one of two conditions, a standard adherence intervention package plus a structured three session group intervention or to a standard adherence intervention package alone. Self-reported adherence was measured using the Adult AIDS Clinical Trials Group adherence instrument prior to, post intervention and at follow-up. Baseline characteristics were similar for both conditions. At post-intervention, adherence information knowledge increased significantly in the intervention condition in comparison to the standard of care, while adherence motivation and skills did not significantly change among the conditions over time. There was a significant improvement in ART adherence and CD4 count and a significant reduction of depression scores over time in both conditions, however, no significant intervention effect between conditions was found. Lay healthworkers may be a useful adjunct to treatment to enhance the adherence information component of the medication adherence intervention, but knowledge may be necessary but not sufficient to increase adherence in this sample. Psychosocial informational interventions may require more advanced skill training in lay health workers to achieve superior adherenceoutcomes in comparison standard care in this resource-constrained setting

New approaches, new activities and new outcomes in international conferences on HIV/AIDS in Africa – Report of the 3rd African Conference on the social aspects of HIV/AIDS, Dakar, 10 - 14 October 2005

Africa's HIV/AIDS situation remains cause for concern. The impact of HIV is considerable and threatens the survival and development of African societies. Although much has been attempted, the results still leave much to be desired. AIDS is an epidemic that needs to be addressed with much creativity and spirit of initiative. It is against this background that the 3rd African conference on the social aspects of HIV/AIDS brought innovations in the way international conferences are designed, activities implemented and results obtained. The innovations concerned the approach to international conferences and take into account reconceptualising HIV/AIDS so as to encourage holistic approaches and better visibility of vulnerable groups.The activities of the conference were organised in such a way as to get people living with HIV/AIDS (PLWHA), grassroots communities and marginalised groups to play a focal role.The conference offered an opportunity for developing cultural activities that would translate the African cultural concepts that had been identified as important in the HIV situation and response analysis. Interaction at the conference created an opportunity to analyse the various dimensions of the political, cultural and economic determinants. The conference offered food for thought around response construction while singling out the themes of urgency and acceleration of response, synergy construction, and coordination and conception of political responses. Keywords: conference, policies, HIV/AIDS, cultural aspects, responses, determinants Journal of Social Aspects of HIV/AIDS Vol. 3 (2) August 2006: 424-44

Increasing plant diversity does not influence productivity: empirical evidence and potential mechanisms

The relationship between species diversity and ecosystem functions has generated considerable debate among ecologists. Ecosystem functions (e.g. productivity, nutrient retention) are often positively correlated with species richness in experimental plant assemblages, but little or no correlation exists in natural communities.We examined the effects of species richness on productivity and available soil nitrate by experimentally manipulating richness using random draws from a pool of ten perennial grasses. Species richness had no significant effect on aboveground productivity or soil nitrate availability, suggesting that functional diversity may be more important than species richness in determining ecosystem functions. The relationship between diversity and ecosystem functions may also depend on resource limitation. A positive relationship is expected when below-ground resources are limiting, but the relationship is expected to weaken when below-ground resource supply rates are higher and competition for light becomes more important. Further experiments are required to determine the mechanisms underlying diversity-productivity relationships

LAPW frozen-phonon calculation, shell model lattice dynamics and specific-heat measurement of SnO

An ab-initio Linear Augmented Plane-Wave (LAPW) calculation of the zone-centered phonon frequencies of SnO has been performed. E$_g$ symmetry has been ascribed to the mode observed at 113 cm$^{-1}$ in Raman measurements, discarding a previous B$_{1g}$ assignement. The other phonon modes measured by Raman spectroscopy are also well reproduced. A new shell-model has also been developed, that gives good agreement of the zone-centered frequencies compared to the measured data and the LAPW results. Specific heat measurements have been performed between 5 K and 110 K. Computation of the specific heat and the M\"{o}ssbauer recoilless fraction with the improved shell-model shows a good agreement with the experimental data as a function of temperature.Comment: 11 pages, 1 figure. to appear in Phys. Rev. B (November 1999

Report and policy brief from the 4th Africa Conference on Social Aspects of HIV/AIDS Research: Innovations in access to prevention, treatment and care in HIV/AIDS, Kisumu, Kenya, 29 April - 3 May 2007

About 520 delegates from all over Africa and 21 countries attended the conference. This report and policy brief summarises the key findings and suggested policy options that emerged from rapporteur reports of conference proceedings including the following themes: (1) Orphans and vulnerable children, (2) Treatment, (3) Prevention, (4) Gender and male involvement, (5) Male circumcision, (6) People living with HIV/AIDS, (7) Food and nutrition, (8) Socioeconomics, and (9) Politics/policy. Two (11.8%) of the 17 OVC projects from the three countries were classified as best practice interventions. Of the 83 abstracts that were accepted at the conference, only 7 (8.4%) were dealing with antiretroviral therapy (ART).There has been tremendous effort by various organisations to provide information about prevention of HIV/AIDS. Information received by adolescents has been effective in increasing their knowledge, but without positive sexual behaviour change.The conference noted the contribution of gender discrimination and violence to the HIV epidemic and the different risks that men and women face in relation to the epidemic. Social scientists need to study the deep cultural meanings attached to male circumcision among different ethnic groups to be able to guide the debate on the latest biomedical findings on the protective effect of circumcision against HIV. Palliative care and support is crucial for coping among people living with HIV/AIDS (PLWHA) in order to deal with medical and psychological issues. Results from several countries have helped researchers to explore alternative ways of examining poverty in the context of HIV and AIDS. Policy frameworks which are likely to succeed in combating HIV/AIDS need to be updated to cover issues of access, testing, disclosure and stigma. In general, the conference was successful in identifying innovations in access to prevention, treatment and care in HIV/AIDS. SAHARA J Vol. 4 (2) 2007: pp. 640-65

CO2-SR technology using NiBa unsupported catalyst. Isotopic study of cyclic process of CO2 storage and in situ regeneration with CH4

The unsupported NiBa catalyst has been used in the CO2-SR (CO2 Storage and in situ Regeneration with CH4) cyclic technology, which allows the use of CO2 from combustion and CH4 from biogas in order to produce enriched syngas streams. The isotopic study in transient regime, using 13CO2 and CD4 instead of 12CO2 and CH4, respectively, has been performed to discriminate the different carbon and hydrogen sources and the participation of the catalyst in the pathways involved in the whole cyclic process of the integrated capture of CO2 and the regeneration with CH4. The dual functionality of the catalyst showed a high chemical retention capacity of CO2 (around 0.15 mmol CO2⋅gcat-1 ) in basic Ni-Ba intermetallic centers together with the regeneration capacity through the injection of methane yielding to H2-containing stream production. During the storage stage, the CO2 adsorption and dissociative decomposition are the main reactions together with Boudouard reaction, whereas in the regeneration step, syngas was formed via chemical CO2 reduction by CH4, besides dry methane reforming.Funding for open access charge: Universidad de Malaga ´ / CBU

Gas hydrate measurements at Hydrate Ridge using Raman spectroscopy

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 71: 2947-2959, doi:10.1016/j.gca.2007.03.032.Oceanic gas hydrates have been measured near the seafloor for the first time using a seagoing Raman spectrometer at Hydrate Ridge, Oregon, where extensive layers of hydrates have been found to occur near the seafloor. All of the hydrates analyzed were liberated from the upper meter of the sediment column near active gas venting sites in water depths of 770-780 m. Hydrate properties, such as structure and composition, were measured with significantly less disturbance to the sample than would be realized with core recovery. The natural hydrates measured were sI, with methane as the predominant guest component, and minor/trace amounts of hydrogen sulfide present in three of the twelve samples measured. Methane large-to-small cage occupancy ratios of the hydrates varied from 1.01 to 1.30, in good agreement with measurements of laboratory synthesized and recovered natural hydrates. Although the samples visually appeared to be solid, varying quantities of free methane gas were detected, indicating the presence of occluded gas a hydrate bubble fabric and/or partial hydrate dissociation in the under-saturated seawater.This work was supported through National Undersea Research Program grant UAF03-0098. DORISS and PUP development was funded by a grant to MBARI from the David and Lucile Packard Foundation

Screening and brief interventions for hazardous and harmful alcohol use among patients with active tuberculosis attending primary care clinics in South Africa: a cluster randomized controlled trial protocol

<p>Abstract</p> <p>Background</p> <p>In 2008 the World Health Organization (WHO) reported that South Africa had the highest tuberculosis (TB) incidence in the world. This high incidence rate is linked to a number of factors, including HIV co-infection and alcohol use disorders. The diagnosis and treatment package for TB and HIV co-infection is relatively well established in South Africa. However, because alcohol use disorders may present more insidiously, making it difficult to diagnose, those patients with active TB and misusing alcohol are not easily cured from TB. With this in mind, the primary purpose of this cluster randomized controlled trial is to provide screening for alcohol misuse and to test the efficacy of brief interventions in reducing alcohol intake in those patients with active TB found to be misusing alcohol in primary health care clinics in three provinces in South Africa.</p> <p>Methods/Design</p> <p>Within each of the three selected health districts with the highest TB burden in South Africa, 14 primary health care clinics with the highest TB caseloads will be selected. Those agreeing to participate will be stratified according to TB treatment caseload and the type of facility (clinic or community health centre). Within strata from 14 primary care facilities, 7 will be randomly selected into intervention and 7 to control study clinics (42 clinics, 21 intervention clinics and 21 control clinics). At the clinic level systematic sampling will be used to recruit newly diagnosed TB patients. Those consenting will be screened for alcohol misuse using the AUDIT. Patients who screen positive for alcohol misuse over a 6-month period will be given either a brief intervention based on the Information-Motivation-Behavioural Skills (IMB) Model or an alcohol use health education leaflet.</p> <p>A total sample size of 520 is expected.</p> <p>Discussion</p> <p>The trial will evaluate the impact of alcohol screening and brief interventions for patients with active TB in primary care settings in South Africa. The findings will impact public health and will enable the health ministry to formulate policy related to comprehensive treatment for TB and alcohol misuse, which will result in reduction in alcohol use and ultimately improve the TB cure rates.</p> <p>Trial registration number</p> <p>PACTR: <a href="http://apps.who.int/trialsearch/trial.aspx?trialid=PACTR201105000297151">PACTR201105000297151</a></p