118 research outputs found
An improved stress corrosion test medium for aluminum alloys
A laboratory test method that is only mildly corrosive to aluminum and discriminating for use in classifying the stress corrosion cracking resistance of aluminum alloys is presented along with the method used in evaluating the media selected for testing. The proposed medium is easier to prepare and less expensive than substitute ocean water
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
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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
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)
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
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