212 research outputs found

    Revisiting the male-produced aggregation pheromone of the lesser mealworm, Alphitobius diaperinus (Coleoptera, Tenebrionidae): identification of a six-component pheromone from a Brazilian population

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    The lesser mealworm, Alphitobius diaperinus Panzer 1797 (Coleoptera: Tenebrionidae), is a cosmopolitan insect pest affecting poultry production. Due to its cryptic behavior, insecticide control is usually not efficient. Thus, sustainable and effective methods would have an enormous and positive impact in poultry production. The aim of this study was to confirm the identity of the male-produced aggregation pheromone for a Brazilian population of A. diaperinus and to evaluate its biological activity in behavioral assays. Six male-specific compounds were identified: (R)-limonene (1), (E)-ocimene (2), 2-nonanone (3), (S)-linalool (4), (R)-daucene (5), all described before in an American population, and a sixth component, (E,E)-α-farnesene (6), which is apparently exclusive to a Brazilian population. Y-Tube bioassays confirmed the presence of a male-produced aggregation pheromone and showed that all components need to be present in a similar ratio and concentration as emitted by male A. diaperinus to produce a positive chemotactic response

    Harnessing microbial volatiles to replace pesticides and fertilizers

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    Global agricultural systems are under increasing pressure to deliver sufficient, healthy food for a growing population. Seasonal inputs, including synthetic pesticides and fertilizers, are applied to reduce losses by pathogens, and enhance crop biomass, although their production and application can also incur several economic and environmental penalties. New solutions are therefore urgently required to enhance crop yield whilst reducing dependence on these seasonal inputs. Volatile Organic Compounds (VOCs) produced by soil microorganisms may provide alternative solutions, due to their ability to inhibit fungal pathogens, induce plant resistance against pathogens, and enhance plant growth promotion. This review will highlight recent advances in our understanding of these biological activities of microbial VOCs (mVOCs), providing perspectives on research required to develop them into viable alternatives to current unsustainable seasonal inputs. This can identify potential new avenues for mVOC research and stimulate discussion across the academic community 25 and agri-business sector

    Positive and negative well-being and objectively measured sedentary behaviour in older adults: evidence from three cohorts

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    Background: Sedentary behaviour is related to poorer health independently of time spent in moderate to vigorous physical activity. The aim of this study was to investigate whether wellbeing or symptoms of anxiety or depression predict sedentary behaviour in older adults. Method: Participants were drawn from the Lothian Birth Cohort 1936 (LBC1936) (n = 271), and the West of Scotland Twenty-07 1950s (n = 309) and 1930s (n = 118) cohorts. Sedentary outcomes, sedentary time, and number of sit-to-stand transitions, were measured with a three-dimensional accelerometer (activPAL activity monitor) worn for 7 days. In the Twenty-07 cohorts, symptoms of anxiety and depression were assessed in 2008 and sedentary outcomes were assessed ~ 8 years later in 2015 and 2016. In the LBC1936 cohort, wellbeing and symptoms of anxiety and depression were assessed concurrently with sedentary behaviour in 2015 and 2016. We tested for an association between wellbeing, anxiety or depression and the sedentary outcomes using multivariate regression analysis. Results: We observed no association between wellbeing or symptoms of anxiety and the sedentary outcomes. Symptoms of depression were positively associated with sedentary time in the LBC1936 and Twenty-07 1950s cohort, and negatively associated with number of sit-to-stand transitions in the LBC1936. Meta-analytic estimates of the association between depressive symptoms and sedentary time or number of sit-to-stand transitions, adjusted for age, sex, BMI, long-standing illness, and education, were β = 0.11 (95% CI = 0.03, 0.18) and β = − 0.11 (95% CI = − 0.19, −0.03) respectively. Conclusion: Our findings indicate that depressive symptoms are positively associated with sedentary behavior. Future studies should investigate the causal direction of this association

    Enantiomeric Discrimination in Insects: The Role of OBPs and ORs

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    Olfaction is a complex recognition process that is critical for chemical communication in insects. Though some insect species are capable of discrimination between compounds that are structurally similar, little is understood about how this high level of discrimination arises. Some insects rely on discriminating between enantiomers of a compound, demonstrating an ability for highly selective recognition. The role of two major peripheral olfactory proteins in insect olfaction, i.e., odorant-binding proteins (OBPs) and odorant receptors (ORs) has been extensively studied. OBPs and ORs have variable discrimination capabilities, with some found to display highly specialized binding capability, whilst others exhibit promiscuous binding activity. A deeper understanding of how odorant-protein interactions induce a response in an insect relies on further analysis such as structural studies. In this review, we explore the potential role of OBPs and ORs in highly specific recognition, specifically enantiomeric discrimination. We summarize the state of research into OBP and OR function and focus on reported examples in the literature of clear enantiomeric discrimination by these proteins

    A qualitative study of independent fast food vendors near secondary schools in disadvantaged Scottish neighbourhoods

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    Background: Preventing and reducing childhood and adolescent obesity is a growing priority in many countries. Recent UK data suggest that children in more deprived areas have higher rates of obesity and poorer diet quality than those in less deprived areas. As adolescents spend a large proportion of time in school, interventions to improve the food environment in and around schools are being considered. Nutrient standards for school meals are mandatory in the UK, but many secondary pupils purchase foods outside schools at break or lunchtime that may not meet these standards. Methods: Qualitative interviews were conducted with fast food shop managers to explore barriers to offering healthier menu options. Recruitment targeted independently-owned shops near secondary schools (pupils aged c.12-17) in low-income areas of three Scottish cities. Ten interviews were completed, recorded, and transcribed for analysis. An inductive qualitative approach was used to analyse the data in NVivo 10. Results: Five themes emerged from the data: pride in what is sold; individual autonomy and responsibility; customer demand; profit margin; and neighbourhood context. Interviewees consistently expressed pride in the foods they sold, most of which were homemade. They felt that healthy eating and general wellbeing are the responsibility of the individual and that offering what customers want to eat, not necessarily what they should eat, was the only way to stay in business. Most vendors felt they were struggling to maintain a profit, and that many aspects of the low-income neighbourhood context would make change difficult or impossible. Conclusions: Independent food shops in low-income areas face barriers to offering healthy food choices, and interventions and policies that target the food environment around schools should take the neighbourhood context into consideration

    A comparison of older and younger offenders with delusional jealousy

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    We sought to determine whether or not there were differences in medical, criminological and legal factors between older and younger offenders with diagnoses of delusional jealousy by undertaking a retrospective case-file search of Australian legal databases. Our results demonstrate that older offenders were more likely to have comorbid dementia whereas younger offenders were more likely to have comorbid substance use and chronic psychotic conditions. A history of domestic violence frequently predated the index offence but we were unable to determine if this was due to psychosis or a pre-existing tendency for violence. Despite a common diagnosis, the older offenders were more likely to be made forensic patients rather than sentenced prisoners when compared with the younger offenders. Consequently, different factors might mediate the pathway to violence in older and younger people suffering from delusional jealousy and could be additional targets for clinical intervention

    Pheromone stereochemical specificity in the biology of the bean beetle Acanthoscelides obtectus

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    The dried bean beetle, Acanthoscelides obtectus, is a serious pest of legume crops, particularly Phaseolus vulgaris beans, and their management is challenging due to the beetle's cryptic larval stage. The major male-produced pheromone of A. obtectus is methyl (E,R)-2,4,5-tetradecatrienoate, crucial for female attraction, with the (S)-enantiomer emitted in smaller amounts (R:S ca. 9:1). Despite its identification half a century ago, it is still not commercially available for bruchid surveillance due to production and stability issues, with gaps in our knowledge relating to the bioactivity of the stereoisomers. We thus aim to clarify the behavioural specificity of the (R)- and (S)- enantiomers of methyl (E)-2,4,5-tetradecatrienoate, along with two commercially available isomers. Electrophysiological (EAG) assays with virgin females show that stereochemically pure methyl (E,R)-2,4,5-tetradecatrienoate is as EAG-active when part of the natural 9:1 or the racemic 1:1 blends, whereas the stereochemically pure (S)-enantiomer is inactive. Moreover, the structural analogues do not elicit significant EAG responses. Virgin females give positive behavioural responses in the olfactometer only to methyl (E,R)-2,4,5-tetradecatrienoate, but not to its antipode or the structural analogues. Furthermore, stereochemically pure methyl (E,R)-2,4,5-tetradecatrienoate elicits the same level of behavioural activity as the 9:1 blend. Curiously, presence of the (S)-enantiomer in equal proportions synergises female preference for stereochemically pure (R). These findings provide a better understanding of the pheromone biology of A. obtectus and create a platform for the development of pheromone trap-based surveillance with racemic methyl (E)-2,4,5-tetradecatrienoate
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