Mosquito Consumption by Insectivorous Bats: Does Size Matter?

Abstract Insectivorous bats have often been touted as biological control for mosquito populations. However, mosquitoes generally represent only a small proportion of bat diet. Given the small size of mosquitoes, restrictions imposed on prey detectability by low frequency echolocation, and variable field metabolic rates (FMR), mosquitoes may not be available to or profitable for all bats. This study investigated whether consumption of mosquitoes was influenced by bat size, which is negatively correlated with echolocation frequency but positively correlated with bat FMR. To assess this, we investigated diets of five eastern Australian bat species (Vespadelus vulturnus Thomas, V. pumilus Gray, Miniopterus australis Tomes, Nyctophilus gouldi Tomes and Chalinolobus gouldii Gray) ranging in size from 4-14 g in coastal forest, using molecular analysis of fecal DNA. Abundances of potential mosquito and non-mosquito prey were concurrently measured to provide data on relative prey abundance. Aedes vigilax was locally the most abundant mosquito species, while Lepidoptera the most abundant insect order. A diverse range of prey was detected in bat feces, although members of Lepidoptera dominated, reflecting relative abundance at trap sites. Consumption of mosquitoes was restricted to V. vulturnus and V. pumilus, two smaller sized bats (4 and 4.5 g). Although mosquitoes were not commonly detected in feces of V. pumilus, they were present in feces of 55 % of V. vulturnus individuals. To meet nightly FMR requirements, Vespadelus spp. would need to consume ~600-660 mosquitoes on a mosquito-only diet, or ~160-180 similar sized moths on a moth-only diet. Lower relative profitability of mosquitoes may provide an explanation for the low level of mosquito consumption among these bats and the absence of mosquitoes in feces of larger bats. Smaller sized bats, especially V. vulturnus, are likely to be those most sensitive to reductions in mosquito abundance and should be monitored during mosquito control activities

Individual Tree Detection in Large-Scale Urban Environments using High-Resolution Multispectral Imagery

We introduce a novel deep learning method for detection of individual trees in urban environments using high-resolution multispectral aerial imagery. We use a convolutional neural network to regress a confidence map indicating the locations of individual trees, which are localized using a peak finding algorithm. Our method provides complete spatial coverage by detecting trees in both public and private spaces, and can scale to very large areas. We performed a thorough evaluation of our method, supported by a new dataset of over 1,500 images and almost 100,000 tree annotations, covering eight cities, six climate zones, and three image capture years. We trained our model on data from Southern California, and achieved a precision of 73.6% and recall of 73.3% using test data from this region. We generally observed similar precision and slightly lower recall when extrapolating to other California climate zones and image capture dates. We used our method to produce a map of trees in the entire urban forest of California, and estimated the total number of urban trees in California to be about 43.5 million. Our study indicates the potential for deep learning methods to support future urban forestry studies at unprecedented scales

Development of high gradient laser wakefield accelerators towards nuclear detection applications at LBNL

Compact high-energy linacs are important to applications including monochromatic gamma sources for nuclear material security applications. Recent laser wakefield accelerator experiments at LBNL demonstrated narrow energy spread beams, now with energies of up to 1 GeV in 3 cm using a plasma channel at low density. This demonstrates the production of GeV beams from devices much smaller than conventional linacs, and confirms the anticipated scaling of laser driven accelerators to GeV energies. Stable performance at 0.5 GeV was demonstrated. Experiments and simulations are in progress to control injection of particles into the wake and hence to improve beam quality and stability. Using plasma density gradients to control injection, stable beams at 1 MeV over days of operation, and with an order of magnitude lower absolute momentum spread than previously observed, have been demonstrated. New experiments are post-accelerating the beams from controlled injection experiments to increase beam quality and stability. Thomson scattering from such beams is being developed to provide collimated multi-MeV monoenergetic gamma sources for security applications from compact devices. Such sources can reduce dose to target and increase accuracy for applications including photofission and nuclear resonance fluorescence

Recommendations for increasing the use of HIV/AIDS resource allocation models

The article of record as published may be found at: http://dx.doi.org/10.1186/1471-2458-9-S1-S8Background: Resource allocation models have not had a substantial impact on HIV/AIDS resource allocation decisions in spite of the important, additional insights they may provide. In this paper, we highlight six difficulties often encountered in attempts to implement such models in policy settings; these are: model complexity, data requirements, multiple stakeholders, funding issues, and political and ethical considerations. We then make recommendations as to how each of these difficulties may be overcome. Results: To ensure that models can inform the actual decision, modellers should understand the environment in which decision-makers operate, including full knowledge of the stakeholders' key issues and requirements. HIV/AIDS resource allocation model formulations should be contextualized and sensitive to societal concerns and decision-makers' realities. Modellers should provide the required education and training materials in order for decision-makers to be reasonably well versed in understanding the capabilities, power and limitations of the model. Conclusion: This paper addresses the issue of knowledge translation from the established resource allocation modelling expertise in the academic realm to that of policymaking

Research-development partnerships for scaling complex innovation: Lessons from the Farmer Business School in IFAD-supported loan-grant collaborations in Asia

The Farmer Business School (FBS) is a participatory, action learning process focused on product and business development, and like the Farmer Field School, is a complex, multi-dimensional innovation with the potential to benefit large numbers of farming households economically, socially and institutionally. Scaling this approach requires rethinking both innovation and scaling. The paper draws on the insights of recent research which argues that a systems approach to innovation can better address the complexity of scaling processes and provides frameworks that link together processes of innovation and scaling. In examining these frameworks, the paper identifies the key role of partnership dynamics in those processes. Drawing on both the innovation and scaling literature and literature on partnership dynamics, a conceptual framework is developed to analyze how partnership dynamics contribute to and constrain the transition from small-scale ‘niche’ innovation testing led by researchers, to large scale integration of the approach by development partners in agricultural ‘regimes’. Using case studies involving partnerships between a small international agricultural research grant recipient and six large development projects supported by IFAD multilateral loans and managed by government agencies undertaken in four Asian countries between 2011 and 2018, the study analyses the variable dynamics of the partnerships from initial networking to integrated collaboration, in the process of scaling the FBS innovation. Responding to the main research question about the drivers of partnership dynamics that contribute to scaling, the paper examines the partnerships in terms of six drivers which derived both from the literature and also from the empirical evidence presented in the study. The drivers include two dimensions of “fit”, one about the convergence of research expertise and development demand, the other about the systematic integration of the innovation with different elements of the development actions. Other drivers relate to the issue of the convergence of project cycles, the stability of staffing in partner organizations, internal decision-making processes and the dimension of “partnering” – the value-based and behavioral aspects of collaboration. The paper also discusses the results of a “partnership health check-up” process conducted periodically during the partnerships and reconsiders the driver about system fit to understand the extent to which there had been a transformation in the conventional ‘regime’ approach to innovations and scaling. Finally, the paper proposes to adjust the conceptual framework based on the analysis of these partnerships for scaling innovations

Civil society leadership in the struggle for AIDS treatment in South Africa and Uganda

Includes abstract.Includes bibliographical references.This thesis is an attempt to theorise and operationalise empirically the notion of ‘civil society leadership’ in Sub-Saharan Africa. ‘AIDS leadership,’ which is associated with the intergovernmental institutions charged with coordinating the global response to HIV/AIDS, is both under-theorised and highly context-specific. In this study I therefore opt for an inclusive framework that draws on a range of approaches, including the literature on ‘leadership’, institutions, social movements and the ‘network’ perspective on civil society mobilisation. This framework is employed in rich and detailed empirical descriptions (‘thick description’) of civil society mobilisation around AIDS, including contentious AIDS activism, in the key case studies of South Africa and Uganda. South Africa and Uganda are widely considered key examples of poor and good leadership (from national political leaders) respectively, while the Treatment Action Campaign (TAC) and The AIDS Support Organisation (TASO) are both seen as highly effective civil society movements. These descriptions emphasise ‘transnational networks of influence’ in which civil society leaders participated (and at times actively constructed) in order to mobilise both symbolic and material resources aimed at exerting influence at the transnational, national and local levels

Foraging Ranges of Insectivorous Bats Shift Relative to Changes in Mosquito Abundance

<div><p>The need to develop effective management strategies for insectivorous bat populations requires an understanding of factors influencing habitat use. Availability of pest prey, such as mosquitoes is likely to be one such factor. To assess whether this is the case, we radio-tracked <i>Vespadelus vulturnus</i> Thomas (little forest bat), a predator of <i>Aedes vigilax</i> Skuse (saltmarsh mosquito), in saltmarsh and adjacent coastal swamp forest during periods of high and low <i>Ae. vigilax</i> abundance. When mosquito abundance in structurally-open saltmarsh was similar to the more cluttered coastal swamp forest, use of saltmarsh by <i>V. vulturnus</i> was disproportionately greater than its availability, with saltmarsh selected preferentially for foraging. However, at times of low <i>Ae. vigilax</i> abundance in saltmarsh, use of saltmarsh by <i>V. vulturnus</i> was reduced and all habitats were used in proportion to availability in the study area. This is the first radio-tracking study to demonstrate a shift in foraging range by an insectivorous bat species correlated with fluctuations in the distribution and abundance of a particular prey resource. The shift in foraging range by <i>V. vulturnus</i>, corresponding with a spatio-temporal variation in abundance of <i>Ae. vigilax</i> highlights the importance of mosquitoes as a dietary item. Broadscale pest control of <i>Ae. vigilax</i> may have ecological implications for the diet and habitat use of <i>V. vulturnus</i>. An adaptive management approach is proposed, whereby careful monitoring of insectivorous bat populations is recommended before and after any application of broadscale mosquito control measures. We also suggest a precautionary approach is taken such that broadscale control of mosquitoes avoids the lactation period of bats, a time when their energetic demands are greatest and when there is reduced risk of contracting mosquito-borne diseases transmitted by <i>Ae. vigilax</i>.</p></div

Habitat availability and use in March 2010.

<p>Percentage of available and used habitat in March 2010.</p