260 research outputs found
PACE into fruit tree spraying practice
A concerted effort was made over a 2 year period (2012-13) to transfer the webpage linked PACE (Pesticide dose Adjustment to the Crop Environment) (Walklate and Cross 2013a) system into commercial practice in the UK and to test the results of its implementation on 7 commercial tree fruit farms, feeding back the results to growers and industry. The aim of PACE is to support lo
A LiDAR crop scanner for managing pesticide dose adjustment
This paper gives a brief description of a LiDAR Crop Scanner (LCS) and associated software for recording and processing sequential range measurements of tree-row structures. The data processing methods have been described in previous publications (Walklate et al., 2002 and Walklate and Cross, 2013). The results of apple orchard measurements show examples of output
Evaluation of laser range-finder mapping for agricultural spraying vehicles
In this paper, we present a new application of laser range-finder sensing to agricultural spraying vehicles. The current generation of spraying vehicles use automatic controllers to maintain the height of the sprayer booms above the crop.
However, these control systems are typically based on ultrasonic sensors mounted on the booms, which limits the accuracy of the measurements and the response of the controller to changes in the terrain, resulting in a sub-optimal spraying process. To overcome these limitations, we propose to use a laser scanner, attached to the front of the sprayer's cabin, to scan the ground surface in front of the vehicle and to build a scrolling 3d map of the terrain. We evaluate the proposed solution in a series of field tests, demonstrating that the approach provides a more detailed and accurate representation of the environment than the current sonar-based solution, and which can lead to the development of more efficient boom control systems
A micro-volume adaptation of a stopped-flow system; use with μg quantities of muscle proteins
Stopped-flow spectroscopy is a powerful method for measuring very fast biological and chemical reactions. The technique however is often limited by the volumes of reactants needed to load the system. Here we present a simple adaptation of commercial stopped-flow system that reduces the volume needed by a factor of 4 to ≈120 μl. After evaluation the volume requirements of the system we show that many standard myosin based assays can be performed using <100 μg of myosin. This adaptation both reduces the volume and therefore mass of protein required and also produces data of similar quality to that produced using the standard set up. The 100 μg of myosin required for these assays is less than that which can be isolated from 100 mg of muscle tissue. With this reduced quantity of myosin, assays using biopsy samples become possible. This will allow assays to be used to assist diagnoses, to examine the effects of post translational modifications on muscle proteins and to test potential therapeutic drugs using patient derived samples
Deconstructing the lesbian, gay, bisexual, transgender victim of sex trafficking: Harm, exceptionality and religion–sexuality tensions
Contrary to widespread belief, sex trafficking also targets lesbian, gay, bisexual, transgender (LGBT) communities. Contemporary social and political constructions of victimhood lie at the heart of regulatory policies on sex trafficking. Led by the US Department of State, knowledge about LGBT victims of trafficking constitutes the newest frontier in the expansion of criminalization measures. These measures represent a crucial shift. From a burgeoning range of preemptive measures enacted to protect an amorphous class of ‘all potential victims’, now policies are heavily premised on the risk posed by traffickers to ‘victims of special interest’. These constructed identities, however, are at odds with established structures. Drawing on a range of literatures, the core task of this article is to confront some of the complexities and tensions surrounding constructions of LGBT trafficking victims. Specifically, the article argues that discourses of ‘exceptional vulnerability’ and the polarized notions of ‘innocence’ and ‘guilt’ inform hierarchies of victimhood. Based on these insights, the article argues for the need to move beyond monolithic understandings of victims, by reframing the politics of harm accordingly
Criminology, Gender and Security in the Australian Context: Making Women’s Lives Matter
This article examines how it might be possible to make women’s lives matter in contemporary criminological understandings of security. In doing so it considers the conceptual complexity of security, and reflects on the criminological engagement with that complexity and the feminist contribution to it paying particular attention to current concerns with everyday security. The article deploys the contemporary Australian policy agenda on family violence to illustrate the paradoxes to be found within these current pre-occupations. Drawing on feminist informed work that situates violence against women within the conceptual framework of everyday terrorism, it concludes by offering further consideration to the meaning of everyday security and the implications that this has for contemporary criminological concerns with security
Victim stories and victim policy: Is there a case for a narrative victimology?
Since the 1980s, victims’ voices have been increasingly heard and have been influential in policy debates. Since that time, the nature and presence of those voices has changed shape and form from the influence and presence of victim centred organizations to the rise of the high profile individual victim. The purpose of this article is to explore the presence of one victim’s story, Rosie Batty, and to examine her influence on the rise of the policy agenda on family violence in Australia. This article considers the ways in which this story gained traction and influenced the reform of family violence policy in Australia, and considers the extent to which an understanding of this process contributes to an (emergent) narrative victimology
Ultrafast glutamate sensors resolve high-frequency release at Schaffer collateral synapses
Glutamatergic synapses display a rich repertoire of plasticity mechanisms on many different time scales, involving dynamic changes in the efficacy of transmitter release as well as changes in the number and function of postsynaptic glutamate receptors. The genetically encoded glutamate sensor iGluSnFR enables visualization of glutamate release from presynaptic terminals at frequencies up to ∼10 Hz. However, to resolve glutamate dynamics during high-frequency bursts, faster indicators are required. Here, we report the development of fast (iGluf) and ultrafast (iGluu) variants with comparable brightness but increased Kd for glutamate (137 μM and 600 μM, respectively). Compared with iGluSnFR, iGluu has a sixfold faster dissociation rate in vitro and fivefold faster kinetics in synapses. Fitting a three-state model to kinetic data, we identify the large conformational change after glutamate binding as the rate-limiting step. In rat hippocampal slice culture stimulated at 100 Hz, we find that iGluu is sufficiently fast to resolve individual glutamate release events, revealing that glutamate is rapidly cleared from the synaptic cleft. Depression of iGluu responses during 100-Hz trains correlates with depression of postsynaptic EPSPs, indicating that depression during high-frequency stimulation is purely presynaptic in origin. At individual boutons, the recovery from depression could be predicted from the amount of glutamate released on the second pulse (paired pulse facilitation/depression), demonstrating differential frequency-dependent filtering of spike trains at Schaffer collateral boutons
Governance of policing and cultural codes: interpreting and responding to policy directives
In terms of governance, British policing seems to arise from a history of local traditions influenced more recently by centralist managerial demands. A creeping process of privatisation has led social scientists to argue that patterns of governance in British policing are changing in several directions. This has included the way police officers not only are challenged, but also challenge these changing modes of governance in terms of ethical codes of behaviour. There is evidence that police officers, as meaningful actors, have made attempts to diverge from these strictures and have forged their own ways, via their cultural knowledge and practices, to ‘do policing’, rather than relying upon codes of practice or rules and regulations
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Identification of sequence changes in myosin II that adjust muscle contraction velocity.
The speed of muscle contraction is related to body size; muscles in larger species contract at slower rates. Since contraction speed is a property of the myosin isoform expressed in a muscle, we investigated how sequence changes in a range of muscle myosin II isoforms enable this slower rate of muscle contraction. We considered 798 sequences from 13 mammalian myosin II isoforms to identify any adaptation to increasing body mass. We identified a correlation between body mass and sequence divergence for the motor domain of the 4 major adult myosin II isoforms (β/Type I, IIa, IIb, and IIx), suggesting that these isoforms have adapted to increasing body mass. In contrast, the non-muscle and developmental isoforms show no correlation of sequence divergence with body mass. Analysis of the motor domain sequence of β-myosin (predominant myosin in Type I/slow and cardiac muscle) from 67 mammals from 2 distinct clades identifies 16 sites, out of 800, associated with body mass (padj 0.05). Both clades change the same small set of amino acids, in the same order from small to large mammals, suggesting a limited number of ways in which contraction velocity can be successfully manipulated. To test this relationship, the 9 sites that differ between human and rat were mutated in the human β-myosin to match the rat sequence. Biochemical analysis revealed that the rat-human β-myosin chimera functioned like the native rat myosin with a 2-fold increase in both motility and in the rate of ADP release from the actin-myosin crossbridge (the step that limits contraction velocity). Thus, these sequence changes indicate adaptation of β-myosin as species mass increased to enable a reduced contraction velocity and heart rate
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