Foraging behaviour of a blue banded bee, Amegilla chlorocyanea in greenhouses: implications for use as tomato pollinators

© INRA, DIB-AGIB, EDP Sciences 2007Blue-banded bees (Amegilla spp.) are Australian native buzz pollinators that are a promising alternative to the introduction of the bumblebee (Bombus terrestris) for use as pollinators of tomatoes in Australian greenhouses. The foraging behaviour of Amegilla chlorocyanea under greenhouse conditions was monitored in detail. Our results showed that female Amegilla are active foragers that make on average 9 pollen foraging flights per day. Using data about flower visitation, we estimated the number of actively nesting female bees needed for adequate pollination in a commercial greenhouse as 282 per hectare.Katja Hogendoorn, Steven Coventry and Michael Anthony Kelle

Stabilisation of BGK modes by relativistic effects

Context. We examine plasma thermalisation processes in the foreshock region of astrophysical shocks within a fully kinetic and self-consistent treatment. We concentrate on proton beam driven electrostatic processes, which are thought to play a key role in the beam relaxation and the particle acceleration. Our results have implications for the effectiveness of electron surfing acceleration and the creation of the required energetic seed population for first order Fermi acceleration at the shock front. Aims. We investigate the acceleration of electrons via their interaction with electrostatic waves, driven by the relativistic Buneman instability, in a system dominated by counter-propagating proton beams. Methods. We adopt a kinetic Vlasov-Poisson description of the plasma on a fixed Eulerian grid and observe the growth and saturation of electrostatic waves for a range of proton beam velocities, from 0.15c to 0.9c. Results. We can report a reduced stability of the electrostatic wave (ESW) with increasing non-relativistic beam velocities and an improved wave stability for increasing relativistic beam velocities, both in accordance with previous findings. At the highest beam speeds, we find the system to be stable again for a period of ≈160 plasma periods. Furthermore, the high phase space resolution of the Eulerian Vlasov approach reveals processes that could not be seen previously with PIC simulations. We observe a, to our knowledge, previously unreported secondary electron acceleration mechanism at low beam speeds. We believe that it is the result of parametric couplings to produce high phase velocity ESW’s which then trap electrons, accelerating them to higher energies. This allows electrons in our simulation study to achieve the injection energy required for Fermi acceleration, for beam speeds as low as 0.15c in unmagnetised plasma

Prevalence and measurement of anxiety in samples of patients with heart failure

© 2016 Wolters Kluwer Health, Inc. Objectives: Rates of anxiety in patients with heart failure (HF) vary widely, and not all assessment instruments used in this patient population are appropriate. It is timely to consolidate the evidence base and establish the prevalence and variance of anxiety in HF samples. Methods: A systematic review, meta-analysis, and meta-regression were conducted to identify the prevalence, variance, and measurement of anxiety in patients with HF. Results: A total of 14,367 citations were identified, with 73 studies meeting inclusion criteria. A random effects pooled prevalence of 13.1% (95% confidence interval [CI], 9.25%-16.86%) for anxiety disorders, 28.79% (95% CI, 23.30%-34.29) for probable clinically significant anxiety, and 55.5% (95% CI, 48.08%-62.83%) for elevated symptoms of anxiety was identified. Rates of anxiety were highest when measured using the Brief Symptom Scale-Anxiety scale (72.3%) and lowest when measured using the Generalised Anxiety Disorder-7 (6.3%). Conclusion: Many patients with HF would benefit if screened for anxiety and treated. The conceptualization and measurement of anxiety accounted for most variance in prevalence rates. The Generalised Anxiety Disorder-7 or the Hospital Anxiety and Depression Scale appear to be the most appropriate instruments for this clinical population, with evidence to suggest they can discriminate between depression and anxiety, omit somatic items that may contaminate identification of anxiety in a population with physical comorbidities, and provide thresholds with which to differentiate patients and target treatments. Although there are limitations with the collation of diverse measurement methods, the current review provides researchers and clinicians with a more granular knowledge of prevalence estimates of anxiety in a population of HF patients.The research was funded through an interdisciplinary doctoral studentship jointly funded by the Medical Research Council and the Economics and Social Research Council

Risk Management Strategies by Australian Farmers

Australian farmers operate in one of the most risky environment in the world. They have to cope with various sources of risk in their businesses. This paper reports results of two case studies undertaken to examine the issues of farming risks and risk management strategies in Australia. The first case study found that climate variability, financial risk, marketing risk, and personal risk were regarded as the major sources of farming risk in the Upper Eyre Peninsula of South Australia. The main management strategies used by farmers included diversifying varieties, minimising tillage, minimising area of risky crops and maximising area of the least-risky crop, having high equity, having farm management deposits and other off-farm investments, and "leaving marketing to experts". The second case study revealed that climate variability was ranked as the most important source of farming risk in southwest Queensland. This was then followed by financial risks, government policy, and marketing risks. The main management strategies used were enterprise diversification (having predominantly cattle and farming cash crops), conserving moisture, using zero till planting, diversified sales (selling only part of the farm's production at any one time), and having off-farm investments. The paper then attempts to reconcile the two case studies by comparing the results with studies from the United States of America, Canada, Netherlands, and New Zealand.risk, risk management, strategies, farmers, Australia, Farm Management, Risk and Uncertainty,

A mixed-methods pilot study of the acceptability and effectiveness of a brief meditation and mindfulness intervention for people with diabetes and coronary heart disease.

PublishedClinical TrialJournal ArticleResearch Support, Non-U.S. Gov'tMindfulness-based interventions can successfully target negative perseverative cognitions such as worry and thought suppression, but their acceptability and effectiveness in people with long-term conditions is uncertain. We therefore pilot tested a six-week meditation and mindfulness intervention in people (n = 40) with diabetes mellitus and coronary heart disease. We used a sequential mixed-methods approach that measured change in worry and thought suppression and qualitatively explored acceptability, feasibility, and user experience with a focus group (n = 11) and in-depth interviews (n = 16). The intervention was highly acceptable, with 90% completing ≥5 sessions. Meditation and mindfulness skills led to improved sleep, greater relaxation, and more-accepting approaches to illness and illness experience. At the end of the six-week meditation course, worry, and thought suppression were significantly reduced. Positive impacts of mindfulness-based interventions on psychological health may relate to acquisition and development of meta-cognitive skills but this needs experimental confirmation.NIHR Collaboration for Leadership in Applied Health Research and Care forGreater Manchester

Naming Spatial Relations Across the Adult Lifespan: At the Crossroads of Language and Perception

Objective: Language abilities in adulthood remain relatively intact with increasing age, while spatial abilities decline. However, much less is known about ageing effects on spatial language (the ability to verbally describe where objects are located in relation to other objects). The primary goal of this study was to examine age-related changes in naming static and dynamic spatial relations across the adult lifespan. Moreover, we examined whether spatial naming is more closely associated with (non-spatial) verbal or (non-linguistic) visuospatial abilities. Method: Healthy adults aged between 18 and 85 years completed a newly developed Spatial Naming Test (SNT), as well as standard object and action naming tests and various visuospatial tasks. The psychometric properties of the novel SNT (inter-rater and test–retest reliability and convergent, divergent, and construct validity) were also examined. Results: The psychometric evaluation confirmed the reliability and validity of the SNT. Striking effects of ageing on naming of both static and dynamic spatial relations were found, as well as on visuospatial abilities, while object and action naming remained age invariant. Moreover, both (non-spatial) verbal and (non-linguistic) visuospatial abilities predicted static spatial naming, but only visuospatial abilities accounted for significant variance in dynamic spatial naming beyond age. Conclusions: These findings provide the first evidence that naming spatial relations declines in ageing as a function of changes in non-linguistic visuospatial abilities, indicating strong connections between linguistic and non-linguistic representations of space. Theoretical and practical implications of these findings are discusse

Altered hippocampal function in major depression despite intact structure and resting perfusion

Background: Hippocampal volume reductions in major depression have been frequently reported. However, evidence for functional abnormalities in the same region in depression has been less clear. We investigated hippocampal function in depression using functional magnetic resonance imaging (fMRI) and neuropsychological tasks tapping spatial memory function, with complementing measures of hippocampal volume and resting blood flow to aid interpretation. Method: A total of 20 patients with major depressive disorder (MDD) and a matched group of 20 healthy individuals participated. Participants underwent multimodal magnetic resonance imaging (MRI): fMRI during a spatial memory task, and structural MRI and resting blood flow measurements of the hippocampal region using arterial spin labelling. An offline battery of neuropsychological tests, including several measures of spatial memory, was also completed. Results: The fMRI analysis showed significant group differences in bilateral anterior regions of the hippocampus. While control participants showed task-dependent differences in blood oxygen level-dependent (BOLD) signal, depressed patients did not. No group differences were detected with regard to hippocampal volume or resting blood flow. Patients showed reduced performance in several offline neuropsychological measures. All group differences were independent of differences in hippocampal volume and hippocampal blood flow. Conclusions: Functional abnormalities of the hippocampus can be observed in patients with MDD even when the volume and resting perfusion in the same region appear normal. This suggests that changes in hippocampal function can be observed independently of structural abnormalities of the hippocampus in depression

Dendritic cell density and activation status in human breast cancer – CD1a, CMRF-44, CMRF-56 and CD-83 expression

Low CD1a-positive putative dendritic cell numbers in human breast cancer has recently been described and may explain the apparent ‘poor immunogenicity’ previously reported in breast cancer. Little attention has been given to dendritic cell activation within the tumour microenvironment, which is another reason why the in-situ immune response may be severely deficient. We have therefore examined CD1a expression as a marker for dendritic cells, together with CMRF-44 and -56 as markers of dendritic cell activation status, in 40 human breast cancers. The results demonstrate few or no CD1a-positive putative dendritic cells and minimal or no expression of the dendritic cell activation markers. Both dendritic cell number and dendritic cell activation appear substantially deficient in human breast cancers, regardless of tumour histological grade

CD1a-positive infiltrating-dendritic cell density and 5-year survival from human breast cancer

© Churchill LivingstoneInfiltrating CD1a+ dendritic cells (DCs) have been associated with increased survival in a number of human cancers. This study investigated DC infiltration within breast cancers and the association with survival. Classical established prognostic factors, of tumour size, lymph node status, histological grade, lympho-vascular invasion, the KI-67 (MIB-1) fraction and the Nottingham Prognostic Index (NPI) were also compared. A total of 48 breast cancer patients were followed from the time of surgery and CD1a density analysis for 5 years or until death. Our data set validated previous studies, which show a relationship between survival and the NPI (P<0.001), tumour size (P<0.01) and lymph node status (P<0.05). Although more patients were alive at the 5-year time point in the group with higher CD1a DC density than the lower CD1a DC group, this failed to reach statistical significance at the P=0.05 level. Analysis at 10 years postsurgery is required to investigate the association further.B.J.Coventry and J. Morto