Interactive effects of mycorrhizae and a root hemiparasite on plant community productivity and diversity

Plant communities can be affected both by arbuscular mycorrhizal fungi (AMF) and hemiparasitic plants. However, little is known about the interactive effects of these two biotic factors on the productivity and diversity of plant communities. To address this question, we set up a greenhouse study in which different AMF inocula and a hemiparasitic plant (Rhinanthus minor) were added to experimental grassland communities in a fully factorial design. In addition, single plants of each species in the grassland community were grown with the same treatments to distinguish direct AMF effects from indirect effects via plant competition. We found that AMF changed plant community structure by influencing the plant species differently. At the community level, AMF decreased the productivity by 15-24%, depending on the particular AMF treatment, mainly because two dominant species, Holcus lanatus and Plantago lanceolata, showed a negative mycorrhizal dependency. Concomitantly, plant diversity increased due to AMF inoculation and was highest in the treatment with a combination of two commercial AM strains. AMF had a positive effect on growth of the hemiparasite, and thereby induced a negative impact of the hemiparasite on host plant biomass which was not found in non-inoculated communities. However, the hemiparasite did not increase plant diversity. Our results highlight the importance of interactions with soil microbes for plant community structure and that these indirect effects can vary among AMF treatments. We conclude that mutualistic interactions with AMF, but not antagonistic interactions with a root hemiparasite, promote plant diversity in this grassland community.

Social Inequality in Political Participation: The Dark Sides of Individualisation

Has the participatory gap between social groups widened over the past decades? And if so, how can it be explained? Based on a re-analysis of 94 electoral surveys in eight Western European countries between 1956 and 2009, this article shows that the difference in national election turnout between the half of the population with the lowest level of education and the half with the highest has increased. It shows that individualisation – the decline of social integration and social control – is a major cause of this trend. In their electoral choices, citizens with fewer resources – in terms of education – rely more heavily on cues and social control of the social groups to which they belong. Once the ties to these groups loosen, these cues and mobilising norms are no longer as strong as they once were, resulting in an increasing abstention of the lower classes on Election Day. In contrast, citizens with abundant resources rely much less on cues and social control, and the process of individualisation impacts on their participatory behaviour to a much lesser extent. The article demonstrates this effect based on a re-analysis of five cumulative waves of the European Social Survey.

Plant and arthropod community sensitivity to rainfall manipulation but not nitrogen enrichment in a successional grassland ecosystem

Grasslands provide many ecosystem services including carbon storage, biodiversity preservation and livestock forage production. These ecosystem services will change in the future in response to multiple global environmental changes, including climate change and increased nitrogen inputs. We conducted an experimental study over 3 years in a mesotrophic grassland ecosystem in southern England. We aimed to expose plots to rainfall manipulation that simulated IPCC 4th Assessment projections for 2100 (+15 % winter rainfall and −30 % summer rainfall) or ambient climate, achieving +15 % winter rainfall and −39 % summer rainfall in rainfall-manipulated plots. Nitrogen (40 kg ha−1 year−1) was also added to half of the experimental plots in factorial combination. Plant species composition and above ground biomass were not affected by rainfall in the first 2 years and the plant community did not respond to nitrogen enrichment throughout the experiment. In the third year, above-ground plant biomass declined in rainfall-manipulated plots, driven by a decline in the abundances of grass species characteristic of moist soils. Declining plant biomass was also associated with changes to arthropod communities, with lower abundances of plant-feeding Auchenorrhyncha and carnivorous Araneae indicating multi-trophic responses to rainfall manipulation. Plant and arthropod community composition and plant biomass responses to rainfall manipulation were not modified by nitrogen enrichment, which was not expected, but may have resulted from prior nitrogen saturation and/or phosphorus limitation. Overall, our study demonstrates that climate change may in future influence plant productivity and induce multi-trophic responses in grasslands.

Infra-Population and -Community Dynamics of the Parasites Nosema apis and Nosema ceranae, and Consequences for Honey Bee (Apis mellifera) Hosts

Nosema spp. fungal gut parasites are among myriad possible explanations for contemporary increased mortality of western honey bees (Apis mellifera, hereafter honey bee) in many regions of the world. Invasive Nosema ceranae is particularly worrisome because some evidence suggests it has greater virulence than its congener N. apis. N. ceranae appears to have recently switched hosts from Asian honey bees (Apis cerana) and now has a nearly global distribution in honey bees, apparently displacing N. apis. We examined parasite reproduction and effects of N. apis, N. ceranae, and mixed Nosema infections on honey bee hosts in laboratory experiments. Both infection intensity and honey bee mortality were significantly greater for N. ceranae than for N. apis or mixed infections; mixed infection resulted in mortality similar to N. apis parasitism and reduced spore intensity, possibly due to inter-specific competition. This is the first long-term laboratory study to demonstrate lethal consequences of N. apis and N. ceranae and mixed Nosema parasitism in honey bees, and suggests that differences in reproduction and intra-host competition may explain apparent heterogeneous exclusion of the historic parasite by the invasive species

Risk factors for depressed mood amongst a community dwelling older age population in England: cross-sectional survey data from the PRO-AGE study.

BACKGROUND The Quality and Outcomes Framework in the United Kingdom (UK) National Health Service previously highlighted case finding of depression amongst patients with diabetes or coronary heart disease. However, depression in older people remains under-recognized. Comprehensive data for analyses of the association of depression in older age with other health and functional measures, and demographic factors from community populations within England, are lacking. METHODS Secondary analyses of cross-sectional baseline survey data from the England arm of a randomised controlled trial of health risk appraisal for older people in Europe; PRO-AGE study. Data from 1085 community-dwelling non-disabled people aged 65 years or more from three group practices in suburban London contributed to this study. Depressed mood was ascertained from the 5-item Mental Health Inventory Screening test. Exploratory multivariable logistic regression was used to identify the strongest associations of depressed mood with a previous diagnosis of a specified physical/mental health condition, health and functional measures, and demographic factors. RESULTS Depressed mood occurred in 14% (155/1085) of participants. A previous diagnoses of depression (OR 3.39; P < 0.001) and poor vision as determined from a Visual Function Questionnaire (OR 2.37; P = 0.001) were amongst the strongest factors associated with depressed mood that were independent of functional impairment, other co-morbidities, and demographic factors. A subgroup analyses on those without a previous diagnosis of depression also indicated that within this group, poor vision (OR 2.51; P = 0.002) was amongst the strongest independent factors associated with depressed mood. CONCLUSIONS Previous case-finding strategies in primary care focussed on heart disease and diabetes but health-related conditions other than coronary heart disease and diabetes are also associated with an increased risk for depression. Complex issues of multi-morbidity occur within aging populations. 'Risk' factors that appeared stronger than those, such as, diabetes and coronary heart disease that until recently prompted for screening in the UK due to the QOF, were identified, and independent of other morbidities associated with depressed mood. From the health and functional factors investigated, amongst the strongest factors associated with depressed mood was poor vision. Consideration to case finding for depressed mood among older people with visual impairment might be justified.

Species richness, but not phylogenetic diversity, influences community biomass production and temporal stability in a re-examination of 16 grassland biodiversity studies

* Hundreds of experiments have now manipulated species richness (SR) of various groups of organisms and examined how this aspect of biological diversity influences ecosystem functioning. Ecologists have recently expanded this field to look at whether phylogenetic diversity (PD) among species, often quantified as the sum of branch lengths on a molecular phylogeny leading to all species in a community, also predicts ecological function. Some have hypothesized that phylogenetic divergence should be a superior predictor of ecological function than SR because evolutionary relatedness represents the degree of ecological and functional differentiation among species. But studies to date have provided mixed support for this hypothesis. * Here, we reanalyse data from 16 experiments that have manipulated plant SR in grassland ecosystems and examined the impact on above-ground biomass production over multiple time points. Using a new molecular phylogeny of the plant species used in these experiments, we quantified how the PD of plants impacts average community biomass production as well as the stability of community biomass production through time. * Using four complementary analyses, we show that, after statistically controlling for variation in SR, PD (the sum of branches in a molecular phylogenetic tree connecting all species in a community) is neither related to mean community biomass nor to the temporal stability of biomass. These results run counter to past claims. However, after controlling for SR, PD was positively related to variation in community biomass over time due to an increase in the variances of individual species, but this relationship was not strong enough to influence community stability. * In contrast to the non-significant relationships between PD, biomass and stability, our analyses show that SR per se tends to increase the mean biomass production of plant communities, after controlling for PD. The relationship between SR and temporal variation in community biomass was either positive, non-significant or negative depending on which analysis was used. However, the increases in community biomass with SR, independently of PD, always led to increased stability. These results suggest that PD is no better as a predictor of ecosystem functioning than SR. * Synthesis. Our study on grasslands offers a cautionary tale when trying to relate PD to ecosystem functioning suggesting that there may be ecologically important trait and functional variation among species that is not explained by phylogenetic relatedness. Our results fail to support the hypothesis that the conservation of evolutionarily distinct species would be more effective than the conservation of SR as a way to maintain productive and stable communities under changing environmental conditions.

Patients with community acquired pneumonia admitted to European intensive care units: an epidemiological survey of the GenOSept cohort.

INTRODUCTION Community acquired pneumonia (CAP) is the most common infectious reason for admission to the Intensive Care Unit (ICU). The GenOSept study was designed to determine genetic influences on sepsis outcome. Phenotypic data was recorded using a robust clinical database allowing a contemporary analysis of the clinical characteristics, microbiology, outcomes and independent risk factors in patients with severe CAP admitted to ICUs across Europe. METHODS Kaplan-Meier analysis was used to determine mortality rates. A Cox Proportional Hazards (PH) model was used to identify variables independently associated with 28-day and six-month mortality. RESULTS Data from 1166 patients admitted to 102 centres across 17 countries was extracted. Median age was 64 years, 62% were male. Mortality rate at 28 days was 17%, rising to 27% at six months. Streptococcus pneumoniae was the commonest organism isolated (28% of cases) with no organism identified in 36%. Independent risk factors associated with an increased risk of death at six months included APACHE II score (hazard ratio, HR, 1.03; confidence interval, CI, 1.01-1.05), bilateral pulmonary infiltrates (HR1.44; CI 1.11-1.87) and ventilator support (HR 3.04; CI 1.64-5.62). Haematocrit, pH and urine volume on day one were all associated with a worse outcome. CONCLUSIONS The mortality rate in patients with severe CAP admitted to European ICUs was 27% at six months. Streptococcus pneumoniae was the commonest organism isolated. In many cases the infecting organism was not identified. Ventilator support, the presence of diffuse pulmonary infiltrates, lower haematocrit, urine volume and pH on admission were independent predictors of a worse outcome.

Specific herbivore-induced volatiles defend plants and determine insect community composition in the field

In response to insect attack, plants release complex blends of volatile compounds. These volatiles serve as foraging cues for herbivores, predators and parasitoids, leading to plant-mediated interactions within and between trophic levels. Hence, plant volatiles may be important determinants of insect community composition. To test this, we created rice lines that are impaired in the emission of two major signals, S-linalool and (E)-β-caryophyllene. We found that inducible S-linalool attracted predators and parasitoids as well as chewing herbivores, but repelled the rice brown planthopper Nilaparvata lugens, a major pest. The constitutively produced (E)-β-caryophyllene on the other hand attracted both parasitoids and planthoppers, resulting in an increased herbivore load. Thus, silencing either signal resulted in specific insect assemblages in the field, highlighting the importance of plant volatiles in determining insect community structures. Moreover, the results imply that the manipulation of volatile emissions in crops has great potential for the control of pest populations.

Species interactions and random dispersal rather than habitat filtering drive community assembly during early plant succession

Theory on plant succession predicts a temporal increase in the complexity of spatial community structure and of competitive interactions: initially random occurrences of early colonising species shift towards spatially and competitively structured plant associations in later successional stages. Here we use long-term data on early plant succession in a German post mining area to disentangle the importance of random colonisation, habitat filtering, and competition on the temporal and spatial development of plant community structure. We used species co-occurrence analysis and a recently developed method for assessing competitive strength and hierarchies (transitive versus intransitive competitive orders) in multispecies communities. We found that species turnover decreased through time within interaction neighbourhoods, but increased through time outside interaction neighbourhoods. Successional change did not lead to modular community structure. After accounting for species richness effects, the strength of competitive interactions and the proportion of transitive competitive hierarchies increased through time. Although effects of habitat filtering were weak, random colonization and subsequent competitive interactions had strong effects on community structure. Because competitive strength and transitivity were poorly correlated with soil characteristics, there was little evidence for context dependent competitive strength associated with intransitive competitive hierarchies.

A focused ethnographic study of community social capital

Social capital, a relatively new public health concept, represents the intangible resources embedded in social relationships that facilitate collective action. Current interest in the concept stems from empirical studies linking social capital with health outcomes. However, in order for social capital to function as a meaningful research variable, conceptual development aimed at refining the domains, attributes, and boundaries of the concept are needed. An existing framework of social capital (Uphoff, 2000), developed from studies in India, was selected for congruence with the inductive analysis of pilot data from a community that was unsuccessful at mobilizing collective action. This framework provided the underpinnings for a formal ethnographic research study designed to examine the components of social capital in a community that had successfully mobilized collective action. The specific aim of the ethnographic study was to examine the fittingness of Uphoff's framework in the contrasting American community. A contrasting context was purposefully selected to distinguish essential attributes of social capital from those that were specific to one community. Ethnographic data collection methods included participant observation, formal interviews, and public documents. Data was originally analyzed according to codes developed from Uphoff's theoretical framework. The results from this analysis were only partially satisfactory, indicating that the theoretical framework required refinement. The refinement of the coding system resulted in the emergence of an explanatory theory of social capital that was tested with the data collected from formal fieldwork. Although Uphoff's framework was useful, the refinement of the framework revealed, (1) trust as the dominant attribute of social capital, (2) efficacy of mutually beneficial collective action as the outcome indicator, (3) cognitive and structural domains more appropriately defined as the cultural norms of the community and group, and (4) a definition of social capital as the combination of the cognitive norms of the community and the structural norms of the group that are either constructive or destructive to the development of trust and the efficacy of mutually beneficial collective action. This explanatory framework holds increased pragmatic utility for public health practice and research. ^

Barriers to Timely Screening Colonoscopy

Objective: Colorectal cancer (CRC) can be largely prevented or effectively treated in its early stages, yet disparities exist in timely screening. The aim of this study was to explore the disparities in CRC screening on the basis of health insurance status including private, Medicare, Medicaid, and State Administered General Assistance (SAGA). Methods: A retrospective chart review for the period January 2000 to May 2007 (95 records) was conducted at two clinic sites; a private clinic and a university hospital clinic. All individuals at these sites who met study criteria (>50 years old with screening colonoscopy) were included. Age, gender, date of first clinic visit when screening referral was made, and date of completed procedure (screening colonoscopy) were recorded. Groups were dichotomized between individuals with private health insurance and individuals with public health insurance. Individuals with any history of CRC, known pre-cancerous conditions as well as family history of CRC requiring frequent colonoscopy were excluded from the study. Linear model analysis was performed to compare the average waiting time to receiving screening colonoscopy between the groups. T-test was performed to analyze age or gender related differences between the two groups as well as within each group. Results: The average waiting time (33 days) for screening colonoscopy in privately insured individuals was significantly lower than publicly insured individuals (200 days). The time difference between the first clinic visit and the procedure was statistically significant (p < 0.0001) between the two groups. There was no statistical difference (p=0.089) in gender between these groups (public vs. private). There were also no statistically significant gender or age related differences found within each group. Conclusions: Disparities exist in timely screening for CRC and one of the barriers leading to delayed CRC screening includes health insurance status of an individual. Even within the insured group, type of insurance plays major role. There is a negative correlation between public health insurance status and timely screening. Differences in access to medical care and delivery of care experienced by patients who are publicly insured through Medicaid, Medicare, and SAGA, suggests that the State of Connecticut needs to implement changes in health care policies that would provide timely screening colonoscopy. It is evident that health insurance coverage facilitates timely access to healthcare. Therefore, there is a need for increased efforts in advocacy for policy, payment and physician participation in public insurance programs. A state-wide comprehensive program involving multiple components targeting different levels of change such as provider, patients and the community should help reduce some of the observed causes of healthcare disparities based on the insurance status.

An evaluation of the impact of Inner City Development's Cooperative Home School: An educational alternative program to increase the quality and level of education in San Antonio's West Side community

The research study was intended to evaluate the effectiveness of Inner City Development's (I.C.D.) Cooperative Home School, an educational alternative program to the Title I public schools of San Antonio's West Side community. The study investigated students', parents' and tutors' perception of parental involvement and educational resources. The study also investigated each student's academic achievement. ^ The study found that students progressed toward expected math proficiency at a faster rate than they did in reading proficiency. However, because the target population size was small and a comparison group was not used, the results of this study are only suggestive. This research also indicated that study subjects believed students' quality and level of education increased substantially since program exposure. Study subjects mainly attributed the students' strides in academic performance to the increased amount of individualized attention students received in the small twelve-student class size. Study subjects were more satisfied with the home school's educational resources than those of the Title I public schools. Study subjects also perceived that parental involvement both at home and at school increased since enrollment in the home school program because: (1) there were more opportunities for involvement in the home school; and (2) parents felt closer to the tutors than the teachers in public school. ^ This evaluation also suggested improvements to program operations. With the help of additional volunteers, I.C.D. program operators could improve collection and organization of academic records. Furthermore, as suggested by program participants, science could be added to the curriculum. Lastly, a formal tutor orientation could be implemented to familiarize and train tutors on classroom management procedures. ^

Psychosocial job characteristics as predictors of overall health: Results from a community-based cross-sectional study conducted in southeast Texas in 2001 and 2002

Stress at the workplace exposes people to increased risk for poor physical and/or mental health. Recently psychological and social disadvantages have been proven to place the worker at risk for mental or physical health outcomes. The overall purpose of this study was to study full time employed study subjects and (1) describe the various psychosocial job characteristics in a population of low income individuals stratified by race/ethnicity residing in Houston and Brownsville, Texas and (2) examine the associations between psychosocial job characteristics and physical, mental, and self rated health. It was observed that having a low level of education is associated with having very little or no control, security, and social support at the workplace. Being Mexican American was associated with having good job control, job security, job social support and having a less demanding job. Furthermore, the psychosocial job characteristics were associated with mental health outcomes but not with physical and self rated health. ^

A systematic review of community-based participatory research interventions in pediatric and adolescent populations

Background. Community-based participatory research (CBPR) is a collaborative approach to research actively involving community members in all aspects of the research process. CBPR is not a new research method, but an approach that has gained increased attention in the field of public health over the last several years. Recognition of the inequalities in health status associated with social and environmental factors have led to calls for a renewed focus on ecological approaches to research. Ecological approaches acknowledge that the health of the community is dependent on an interaction between behavioral and environmental factors affecting the entire population. While many published studies document the benefits of CBPR in difficult-to-reach populations and describe successful implementation of this approach in adult populations, relatively few studies have been conducted in child and adolescent populations. Given that children and adolescents are particularly sensitive to the effects of their physical environments and may also be distrustful of outsiders, ecological approaches involving the community as partners, such as CBPR, may be especially useful in this population. ^ Objective. This thesis reviews published studies using a community-based participatory research approach in children and adolescents to assess the appropriateness of this approach in this population. ^ Method. Studies using CBPR in youth populations were identified using Medline and other Internet searches through both MeSH heading and text-word searches. ^ Results. A total of 16 studies were identified and analyzed for this review. Nine of the sixteen studies were experimental or quasi-experimental design, with Asthma being the most commonly studied disease. ^ Conclusions. While many studies using CBPR were not conducted with the level of scientific rigor typically found in clinical trial research, the studies reviewed each contributed to a greater understanding of the problems they investigated. Furthermore, interventional studies provided lasting benefits to communities under study above what would be found in studies using more traditional research approaches. While CBPR may not be appropriate for all research situations due to the time and resources required, we conclude that is a useful approach and should be considered when conducting community-based research for pediatric and adolescent populations.^

Assessment of markers of medication literacy in a US-Mexico border community

Each year an estimated 180,000 people in the United States (U.S.) die as a result of medication errors, now considered a major public health problem. If a patient cannot correctly act on information related to medication use or "Medication Literacy" there is an increased potential for error. Medication use issues are unique on the US-Mexico border because they include high rates of herbal products and medication products from Mexico as well as issues related to the preferred language (English or Spanish) of the patient. To evaluate the medication literacy in a US-Mexico border community, this retrospective study evaluates 180 subjects representing four diverse economic segments of a metropolitan US-Mexico Border community who have taken a Medication Literacy Assessment. The assessment tool has been created to understand how patients interpret medication information for prescription, over-the-counter, herbal, and Mexican medication product use, and how they problem-solve medication questions. The Medication Literacy Assessment tool specifically assesses document literacy (e.g., prescription labels), prose literacy (e.g., patient leaflets), numeracy (e.g., calculations and measurements) as well as qualitative data related to medication use practices. The main hypothesis of this study is that the ability to interpret and use medications will vary based on education, language (Spanish or English), and recruitment sites (economically diverse communities). The results will provide information to better characterize medication use in a primarily Hispanic population on the US-Mexico border and may be used to influence policy decisions regarding prescription and over-the-counter product information.^