129 research outputs found
Study on high performance insulation thermal design criteria Quarterly progress report
Diffusion coefficients, outgassing studies, and correlation of complete system thermal model computer program predictions with 82.6 inch tank test dat
Combined in situ experimentation and modelling approaches to disentangle processes involved in the earliest stage of community assembly
The ecological process of community assembly is described as the succession of three phases: colonization, regulation and segregation. Early colonization remains the least studied and quantified phase of assembly. In order to fill this gap, an approach combining in situ experiments and modelling was proposed to study colonization by a benthic macrofauna community in open microcosms containing a single, non-limiting resource. The experiment was three months long. A total of 51 taxa were observed in the microcosms, but data analyses of the species composition and abundances revealed that five species, Capitella spp., Gammaropsis maculata, Erichtionus punctatus, Nereiphylla paretti and Harmothoe mariannae, explained most of the observed variation in the assembly process. The population dynamics of these species were simulated taking into account functional traits that govern individual interactions. The dynamic model simulated a demographic stochasticity due to low population densities that result from the small size of the experimental microcosms. Using this combined approach of experiments and modelling, we showed that predation interactions alone can account for the abundances and species composition of primary consumers during the transient phase of early colonization
Quantifying the impact of Psylliodes chrysocephala injury on the productivity of oilseed rape
BACKGROUND: Current European Union and United Kingdom legislation prohibits the use of neonicotinoid insecticidal seedtreatments in oilseed rape (OSR,Brassica napus). This ban, and the reduction in efficacy of pyrethroid insecticide sprays dueto resistance, has exacerbated pest pressure from the cabbage stemflea beetle (Psylliodes chrysocephala) in winter OSR. Wequantified the direct impact of P. chrysocephalainjury on the productivity of OSR. Leaf area was removed from young plantsto simulate differing intensities of adult feeding injury alone or in combination with varying larval infestation levels.
RESULTS: OSR can compensate for up to 90% leaf area loss at early growth stages, with no meaningful effect on yield. Significant impacts were observed with high infestations of more thanfive larvae per plant; plants were shorter, produced fewerflowers and pods, with fewer seeds per pod which had lower oil content and higher glucosinolate content. Such effects werenot recorded whenfive larvae or fewer were present.
CONCLUSION: These data confirm the yield-limiting potential of the larval stages ofP. chrysocephalabut suggest that the current action thresholds which trigger insecticide application for both adult and larval stages (25% leaf area loss andfive larvae/plant, respectively) are potentially too low as they are below the physiological injury level where plants can fully compensatefor damage. Further research infield conditions is needed to define physiological thresholds more accurately as disparity mayresult in insecticide applications that are unnecessary to protect yield and may in turn exacerbate the development and spread of insecticide resistance in P. chrysocephala
Whisker/Cone growth on the thermal control surfaces experiment no. S0069
An unusual surface 'growth' was found during scanning electron microscope (SEM) investigations of the Thermal Control Surface Experiment (TCSE) S0069 front thermal cover. This 'growth' is similar to the cone type whisker growth phenomena as studied by G. K. Wehner beginning in the 1960's. Extensive analysis has identified the most probable composition of the whiskers to be a silicate type glass. Sources of the growth material are outgassing products from the experiment and orbital atomic oxygen, which occurs naturally at the orbital altitudes of the LDEF mission in the form of neutral atomic oxygen. The highly ordered symmetry and directionality of the whiskers are attributed to the long term (5.8 year) stable flight orientation of the LDEF
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Apple pollination: demand depends on variety and supply depends on pollinator identity
Insect pollination underpins apple production but the extent to which different pollinator guilds supply this service, particularly across different apple varieties, is unknown. Such information is essential if appropriate orchard management practices are to be targeted and proportional to the potential benefits pollinator species may provide. Here we use a novel combination of pollinator effectiveness assays (floral visit effectiveness), orchard field surveys (flower visitation rate) and pollinator dependence manipulations (pollinator exclusion experiments) to quantify the supply of pollination services provided by four different pollinator guilds to the production of four commercial varieties of apple. We show that not all pollinators are equally effective at pollinating apples, with hoverflies being less effective than solitary bees and bumblebees, and the relative abundance of different pollinator guilds visiting apple flowers of different varieties varies significantly. Based on this, the taxa specific economic benefits to UK apple production have been established. The contribution of insect pollinators to the economic output in all varieties was estimated to be ÂŁ92.1M across the UK, with contributions varying widely across taxa: solitary bees (ÂŁ51.4M), honeybees (ÂŁ21.4M), bumblebees (ÂŁ18.6M) and hoverflies (ÂŁ0.7M). This research highlights the differences in the economic benefits of four insect pollinator guilds to four major apple varieties in the UK. This information is essential to underpin appropriate investment in pollination services management and provides a model that can be used in other entomolophilous crops to improve our understanding of crop pollination ecology
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Integrated pest management strategies for cabbage stem flea beetle (Psylliodes chrysocephala) in oilseed rape
Oilseed rape (OSR) is the second largest source of vegetable oil globally and the most important biofuel feedstock in the European Union (EU) but production of this important crop is threatened by a small insect; Psylliodes chrysocepaha â the cabbage stem flea beetle (CSFB). The EU ban on use of neonicotinoid seed treatments and resistance of CSFB to pyrethroid insecticides have left farmers with limited control options resulting in drastic reductions in production. Integrated pest management (IPM) may offer a solution. We review the lifecycle of CSFB and the current
options available, or in the research pipeline, for the eight IPM principles of the EU Sustainable Use of Pesticides Directive (Directive-2009/128/EC). A full IPM strategy for CSFB barely exists. Although there are a range of preventative measures these require scientific validation; critically, resistant/tolerant OSR cultivars are not yet available. Existing monitoring methods are time
consuming and there are no commercial models to enable decision support based on predictions migration timing or population size. Available thresholds are not based on physiological tolerances of the plant making it hard to adapt them to changing market prices for the crop and
costs of control. Non-synthetic alternatives tested and registered for use against CSFB are lacking, making resistance management impossible. CSFB control is therefore dependent upon conservation biocontrol. Natural enemies of CSFB are present, but quantification of their effects is
needed and habitat management strategies to exploit their potential. Although some EU countries have local initiatives to reduce insecticide use and encourage use of âgreenerâ alternatives, there is no formal process for ranking these and little information available to help farmers make choices. We summarise the main knowledge gaps and future research needed to improve measures for CSFB control and to facilitate development of a full IPM strategy for this pest -and sustainable oilseeds production
Disciplined into good conduct : Gender constructions of users in a municipal psychiatric context in Sweden
Aims and objectives To examine how gendered discursive norms and notions of masculinity and femininity were (re)produced in professional conversations about users of longâterm municipality psychiatric care. Focus is on the staffâs use of language in relation to gender constructions. Background Psychiatric care in Sweden has undergone tremendous changes in recent decades from custodian care in large hospitals to a care mainly located in a municipal context. People who need psychiatric care services often live in supporting houses. In municipal psychiatric care, staff conduct weekly professional meetings to discuss daily matters and the usersâ needs. Official reports of the Swedish government have shown that staff in municipal care services treat disabled women and men differently. Studies exploring gender in relation to users of longâterm psychiatric care in municipalities have problematised the care and how staff, through language, construct usersâ gender. Therefore, language used by staff is a central tool for ascribing different gender identities of users. Design The content of speech derived from audio recordings were analysed using Foucauldian discursive analysis. The COREQ checklist was used in this article. Results The results indicate that by relying on gender discourses, staff create a conditional care related to how the users should demonstrate good conduct. In line with that, an overall discourse was created: Disciplined into good conduct. It was underpinned by three discourses inherent therein: The unreliable drinker and the confession, Threatened dignity, Doing different femininities. Conclusion The community psychiatric context generates a discourse of conduct in which staff, via spoken language (re)produces gendered patterns and power imbalances as a means to manage daily work routines. Such practices of care, in which constant, nearly panoptic, control despite the intention to promote autonomy, urgently require problematising current definitions of good conduct and normality.Peer reviewe
Failure or success? Defensive strategies and piecemeal change among racial inequalities in the Brazilian banking sector
We analyze how Brazilian Black Movement organizations and banks deployed different mechanisms like cooperation, cooptation, and confrontation that generated affirmative action initiatives in the banking sector at the beginning of this century. Black movement organizations triggered an institutional change by connecting fields and exploring a constellation of strategies. However, Brazilian banks adopted defensive strategies aiming to accommodate their interests. We find that only piecemeal change occurred, as the fieldâs structures â resource distribution and power â remained unscratched. We conclude by noting how the success of social movement strategies can depend upon the framing and sense-giving work that social movements conduct in their continuous jockeying activity toward incumbents
Games People Play: The Collapse of âMasculinitiesâ and the Rise of Masculinity as Spectacle
Perspective is important. When Andy Warhol produced an art piece of 13 police mugshots of âThirteen Most Wanted Menâ for the New York Worldâs Fair in 1964, the work was hurriedly painted over by concerned authorities before the public could view it. It was only years later that the Warholâs subversive (homoerotic) gaze on the FBI list was more widely appreciated (Crimp in Social Text 59: 49â66, 1999; Siegel in Art Journal 62(1): 7â13, 2003). I begin with this story because it points to key issues I want to take up in this chapter, in particular, the importance of âaudienceâ and different readings when it comes to masculinity. While current theory tends to locate masculinity in the actors, what if it is better located in the audience? What if masculinity was better understood as a kind of public spectacle? In addition, there are the naturally subversive elements of gender (e.g. think of drag performances); the game-like nature of masculinity (men might feel compelled to play along with expectations of masculinityâthink of brutal playground expectations on boysâbut it doesnât mean they are not aware of its inauthenticity); and the inevitableâbut less discussed linkâwith sexuality (see below)
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