952 research outputs found
Experimental evidence of the benefit of wild flower strips to crop pollination
Wild bees provide a free and potentially diverse ecosystem service to farmers growing pollinator dependent crops. Whilst many crops benefit from insect pollination, soft fruit crops, including strawberries are commonly dependent on this ecosystem service to produce viable fruit. However, as a result of intensive farming practices and declining pollinator populations, farmers are increasingly turning to commercially reared bees to ensure that crops are adequately pollinated throughout the season. Wildflower strips are a commonly used measure aimed at the conservation of wild pollinators. It has been suggested that commercial crops may also benefit from the presence of sown wild flowers however, the efficacy and economic benefits of sowing flower strips for crops has been little investigated. Here we test whether wildflower strips increase the number of visits to adjacent commercial strawberry crops by wild pollinators. This was quantified by experimentally sowing wildflower strips approximately 20 meters away from the crop and recording the number of pollinator visits to crops with, and without, flower strips. Between June and August 2013 we walked 292 crop transects at six farms in Scotland, recording a total of 3,102 pollinators. On average, the frequency of pollinator visits was 25% higher for crops with adjacent flower strips compared to those without, with bumblebees (Bombus spp.) accounting for 62% of all pollinators observed. This effect was independent of other (potentially important) confounding effects, such as the number of flowers on the crop, date and temperature. Whilst commercial bees may still be required early in the season, this study provides evidence that soft fruit farmers can increase the number of pollinators that visit their crops by sowing inexpensive flower seed mixes nearby. The cost of planting these strips was substantially lower than the annual cost of purchasing commercial bumblebees, with the added advantage that this management option has the potential to increase and sustain pollinator populations over time
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Stress and deformation characteristics of sea ice in a high-resolution, anisotropic sea ice model
The drift and deformation of sea ice floating on the polar oceans is caused by the applied wind and ocean currents. Over ocean basin length scales the internal stresses and boundary conditions of the sea ice pack result in observable deformation patterns. Cracks and leads can be observed in satellite images and within the velocity fields generated from floe tracking. In a climate sea ice model the deformation of sea ice over ocean basin length scales is modelled using a rheology that represents the relationship between stresses and deformation within the sea ice cover. Here we investigate the link between emergent deformation characteristics and the underlying internal sea ice stresses using the Los Alamos numerical sea ice climate model. We have developed an idealized square domain, focusing on the role of sea ice rheologies in producing deformation at spatial resolutions of up to 500âm. We use the elastic anisotropic plastic (EAP) and elastic viscous plastic (EVP) rheologies, comparing their stability, with the EAP rheology producing sharper deformation features than EVP at all space and time resolutions. Sea ice within the domain is forced by idealized winds, allowing for the emergence of five distinct deformation types. Two for a low confinement ratio: convergent and expansive stresses. Two about a critical confinement ratio: isotropic and anisotropic conditions. One for a high confinement ratio and isotropic sea ice. Using the EAP rheology and through the modification of initial conditions and forcing, we show the emergence of the power law of strain rate, in accordance with observations.This article is part of the theme issue 'Modelling of sea-ice phenomena'
The dose makes the poison: have âfield realisticâ rates of exposure of bees to neonicotinoid insecticides been overestimated in laboratory studies?
Recent laboratory based studies have demonstrated adverse sub-lethal effects of neonicotinoid insecticides on honey bees and bumble bees, and these studies have been influential in leading to a European Union moratorium on the use of three neonicotinoids, clothianidin, imidacloprid, and thiamethoxam on âbee attractiveâ crops. Yet so far, these same effects have not been observed in field studies. Here we review the three key dosage factors (concentration, duration and choice) relevant to field conditions, and conclude that these have probably been over estimated in many laboratory based studies
Report on Offense Grading In New Jersey
The University of Pennsylvania Criminal Law Research Group was commissioned to do a study of offense grading in New Jersey. After an examination of New Jersey criminal law and a survey of New Jersey residents, the CLRG issued this Final Report. (For the report of a similar project for Pennsylvania, see Report on Offense Grading in Pennsylvania, http://ssrn.com/abstract=1527149, and for an article about the grading project, see The Modern Irrationalities of American Criminal Codes: An Empirical Study of Offense Grading, http://ssrn.com/abstract=1539083, Journal of Criminal Law and Criminology (forthcoming 2011).) The New Jersey study found serious conflicts between the relative grading judgments of New Jersey residents and those contained in existing New Jersey criminal law, as well as instances where mandatory minimum sentences often require sentences that exceed the maximum appropriate punishment, inconsistencies among the grading of similar offenses, overly broad offenses that impose similar grades on conduct of importantly different seriousness, and a flawed grading structure that provides too few grading categories, thereby assuring pervasive problems in failing to distinguish conduct of importantly different seriousness. These systemic failures risk undermining the criminal justice system\u27s moral credibility with the community, improperly delegate the value judgments inherent in grading decisions to individual sentencing judges ad hoc, fail to give citizens notice of the relative importance of conflicting duties, and invite application of different sentencing rules to similarly situated offenders. The Report examines how these grading problems came about, how they might be fixed, and how such grading irrationalities might be avoided in the future
Report on Offense Grading In New Jersey
The University of Pennsylvania Criminal Law Research Group was commissioned to do a study of offense grading in New Jersey. After an examination of New Jersey criminal law and a survey of New Jersey residents, the CLRG issued this Final Report. (For the report of a similar project for Pennsylvania, see Report on Offense Grading in Pennsylvania, http://ssrn.com/abstract=1527149, and for an article about the grading project, see The Modern Irrationalities of American Criminal Codes: An Empirical Study of Offense Grading, http://ssrn.com/abstract=1539083, Journal of Criminal Law and Criminology (forthcoming 2011).) The New Jersey study found serious conflicts between the relative grading judgments of New Jersey residents and those contained in existing New Jersey criminal law, as well as instances where mandatory minimum sentences often require sentences that exceed the maximum appropriate punishment, inconsistencies among the grading of similar offenses, overly broad offenses that impose similar grades on conduct of importantly different seriousness, and a flawed grading structure that provides too few grading categories, thereby assuring pervasive problems in failing to distinguish conduct of importantly different seriousness. These systemic failures risk undermining the criminal justice system\u27s moral credibility with the community, improperly delegate the value judgments inherent in grading decisions to individual sentencing judges ad hoc, fail to give citizens notice of the relative importance of conflicting duties, and invite application of different sentencing rules to similarly situated offenders. The Report examines how these grading problems came about, how they might be fixed, and how such grading irrationalities might be avoided in the future
The Obliteration of Truth by Management: Badiou, St. Paul and the Question of Economic Managerialism in Education
This paper considers the questions that Badiouâs theory of the subject poses to cultures of economic managerialism within education. His argument that radical change is possible, for people and the situations they inhabit, provides a stark challenge to the stifling nature of much current educational climate. In 'Saint Paul: The Foundation of Universalism', Badiou describes the current universalism of capitalism, monetary homogeneity and the rule of the count. Badiou argues that the politics of identity are all too easily subsumed by the prerogatives of the marketplace and unable to present, therefore, a critique of the status quo. These processes are, he argues, without the potential for truth. What are the implications of Badiouâs claim that education is the arranging of âthe forms of knowledge in such a way that truth may come to pierce a hole in themâ (Badiou, 2005, p. 9)? In this paper, I argue that Badiouâs theory opens up space for a kind of thinking about education that resists its colonisation by cultures of management and marketisation and leads educationalists to consider the emancipatory potential of education in a new light
Neural computations of threat in the aftermath of combat trauma
By combining computational, morphological, and functional analyses, this study relates latent markers of associative threat learning to overt post-traumatic stress disorder (PTSD) symptoms in combat veterans. Using reversal learning, we found that symptomatic veterans showed greater physiological adjustment to cues that did not predict what they had expected, indicating greater sensitivity to prediction errors for negative outcomes. This exaggerated weighting of prediction errors shapes the dynamic learning rate (associability) and value of threat predictive cues. The degree to which the striatum tracked the associability partially mediated the positive correlation between prediction-error weights and PTSD symptoms, suggesting that both increased prediction-error weights and decreased striatal tracking of associability independently contribute to PTSD symptoms. Furthermore, decreased neural tracking of value in the amygdala, in addition to smaller amygdala volume, independently corresponded to higher PTSD symptom severity. These results provide evidence for distinct neurocomputational contributions to PTSD symptoms
Neural computations of threat in the aftermath of combat trauma
Š 2019, The Author(s), under exclusive licence to Springer Nature America, Inc. By combining computational, morphological, and functional analyses, this study relates latent markers of associative threat learning to overt post-traumatic stress disorder (PTSD) symptoms in combat veterans. Using reversal learning, we found that symptomatic veterans showed greater physiological adjustment to cues that did not predict what they had expected, indicating greater sensitivity to prediction errors for negative outcomes. This exaggerated weighting of prediction errors shapes the dynamic learning rate (associability) and value of threat predictive cues. The degree to which the striatum tracked the associability partially mediated the positive correlation between prediction-error weights and PTSD symptoms, suggesting that both increased prediction-error weights and decreased striatal tracking of associability independently contribute to PTSD symptoms. Furthermore, decreased neural tracking of value in the amygdala, in addition to smaller amygdala volume, independently corresponded to higher PTSD symptom severity. These results provide evidence for distinct neurocomputational contributions to PTSD symptoms
SUMO chain-induced dimerization activates RNF4
Dimeric RING E3 ligases interact with protein substrates and conformationally restrain the ubiquitin-E2-conjugating enzyme thioester complex such that it is primed for catalysis. RNF4 is an E3 ligase containing an N-terminal domain that binds its polySUMO substrates and a C-terminal RING domain responsible for dimerization. To investigate how RNF4 activity is controlled, we increased polySUMO substrate concentration by ablating expression of SUMO protease SENP6. Accumulation of SUMO chains in vivo leads to ubiquitin-mediated proteolysis of RNF4. In vitro we demonstrate that at concentrations equivalent to those found in vivo RNF4 is predominantly monomeric and inactive as an ubiquitin E3 ligase. However, in the presence of SUMO chains, RNF4 is activated by dimerization, leading to both substrate ubiquitylation and autoubiquitylation, responsible for degradation of RNF4. Thus the ubiquitin E3 ligase activity of RNF4 is directly linked to the availability of its polySUMO substrates
On the relevance of earnings components in valuation and forecasting
Pre-print also submitted to SSRN Archive. The final publication is available at Springer via http://dx.doi.org/ 10.1007/s11156-013-0347-yThis paper articulates the links between relevance of an earnings component in forecasting (abnormal) earnings and its relevance in valuation in a nonlinear framework. The analysis shows that forecasting relevance does not imply valuation relevance even though valuation irrelevance is implied by forecasting irrelevance. Firstly, I consider an accounting information system where earnings components "add up" to a fully informative earnings number. Secondly, I analyze two accounting systems where a "core" earnings component is the relevant earnings construct for valuation and the second earnings component is irrelevant but may be predictable and relevant in forecasting other accounting items. I find that dividend displacement effect on earnings and the dynamics of individual earnings components are critical in this analysis
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