9,246 research outputs found

    Burial and seed survival in Brassica napus subsp. oleifera and Sinapis arvensis including a comparison of transgenic and non-transgenic lines of the crop

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    The creation of transgenic plants through genetic engineering has focused interest on how the fitness of a plant species may be altered by small changes in its genome. This study concentrates on a key component of fitness: persistence of seeds overwinter. Seeds of three lines of oilseed rape (Brassica napus subsp. oleifera DC Metzger) and of charlock (Sinapis arvensis L.) were buried in nylon mesh bags at two depths in four habitats in each of three geographically separated sites: Cornwall, Berkshire and Sutherland. Seeds were recovered after 12 and 24 months. Charlock exhibited much greater seed survival (average 60 per cent surviving the first year and 32.5 per cent surviving the second year) than oilseed rape (1.5 per cent surviving the first year and 0.2 per cent surviving the second) at all sites. Charlock showed higher survival at 15 cm burial than 2 cm burial at certain sites, but oilseed rape showed no depth effect. Different genetic lines of oilseed rape displayed different rates of seed survival; non-transgenic rape showed greater survival (2 per cent) than the two transgenic lines, one developed for tolerance to the antibiotic kanamycin (0.3 per cent) and one for tolerance to both kanamycin and the herbicide glufosinate (0.25 per cent). The absolute and relative performances of the different genetic lines of oilseed rape were context specific, illustrating the need to test hypotheses in a wide range of ecological settings

    Decision Tree Analysis as a Supplementary Tool to Enhance Histomorphological Differentiation when Distinguishing Human from Non-human Cranial Bone in both Burnt and Unburnt States: A feasibility study

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    This feasibility study was undertaken to describe and record the histological characteristics of burnt and unburnt cranial bone fragments from human and non-human bones. Reference series of fully mineralised, transverse sections of cranial bone, from all variables and specimen states were prepared by manual cutting and semi-automated grinding and polishing methods. A photomicrograph catalogue reflecting differences in burnt and unburnt bone from human and non-humans was recorded and qualitative analysis was performed using an established classification system based on primary bone characteristics. The histomorphology associated with human and non-human samples was, for the main part, preserved following burning at high temperature. Clearly, fibro-lamellar complex tissue subtypes, such as plexiform or laminar primary bone, were only present in non-human bones. A decision tree analysis based on histological features provided a definitive identification key for distinguishing human from non-human bone, with an accuracy of 100%. The decision tree for samples where burning was unknown was 96% accurate, and multi-step classification to taxon was possible with 100% accuracy. The results of this feasibility study, strongly suggest that histology remains a viable alternative technique if fragments of cranial bone require forensic examination in both burnt and unburnt states. The decision tree analysis may provide an additional, but vital tool to enhance data interpretation. Further studies are needed to assess variation in histomorphology taking into account other cranial bones, ontogeny, species and burning conditions

    Corporationsā€”Conditional Supermajority Provisions: Protecting Shareholders\u27 Interestsā€”\u3ci\u3eSeibert v. Gulton Industries, Inc.\u3c/i\u3e, No. 5631 (Del. Ch. June 21, 1979), aff\u27d, No. 219 (Del. Jan. 4, 1980)

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    In Seibert v. Gulton Industries, Inc., the Delaware Supreme Court affirmed the dismissal of a complaint challenging the legality of a conditional supermajority amendment to Gulton Industries\u27 certificate of incorporation. The challenged amendment required the affirmative vote of eighty percent of Gulton\u27s shareholders to approve a proposed takeover of Gulton by any person or entity that had acquired five percent or more of Gulton\u27s shares prior to its proposed takeover. The eighty percent vote was not required if Gulton\u27s directors had approved the proposed takeover prior to the other entity\u27s acquisition of a five percent interest in Gulton. In such cases a simple majority sufficed. Thus, the amendment gave Gulton\u27s directors discretion to invoke the supermajority requirement for takeover attempts they opposed. The chancellor\u27s decision to dismiss plaintiff\u27s complaint was consistent with the enabling philosophy that permeates the relevant Delaware statutory and case law. Nevertheless, the decision failed to discuss the practical implications of enacting conditional supermajority requirements. Specifically, the chancellor did not consider whether Gulton\u27s conditional supermajority provision would adequately protect shareholders\u27 interests to the extent they conflict with management\u27s interests. By dismissing the complaint, the Seibert court failed to consider whether the use of conditional supermajority provisions should be circumscribed by the courts in order to make such measures responsive to the needs of shareholders. This note examines alternatives to dismissal of the plaintiff\u27s complaint and recommends that corporate management be required to disclose the purposes and effects of conditional supermajority provisions when proposing them to shareholders for adoption

    Corporationsā€”Conditional Supermajority Provisions: Protecting Shareholders\u27 Interestsā€”Seibert v. Gulton Industries, Inc., No. 5631 (Del. Ch. June 21, 1979), aff\u27d, No. 219 (Del. Jan. 4, 1980)

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    In Seibert v. Gulton Industries, Inc., the Delaware Supreme Court affirmed the dismissal of a complaint challenging the legality of a conditional supermajority amendment to Gulton Industries\u27 certificate of incorporation. The challenged amendment required the affirmative vote of eighty percent of Gulton\u27s shareholders to approve a proposed takeover of Gulton by any person or entity that had acquired five percent or more of Gulton\u27s shares prior to its proposed takeover. The eighty percent vote was not required if Gulton\u27s directors had approved the proposed takeover prior to the other entity\u27s acquisition of a five percent interest in Gulton. In such cases a simple majority sufficed. Thus, the amendment gave Gulton\u27s directors discretion to invoke the supermajority requirement for takeover attempts they opposed. The chancellor\u27s decision to dismiss plaintiff\u27s complaint was consistent with the enabling philosophy that permeates the relevant Delaware statutory and case law. Nevertheless, the decision failed to discuss the practical implications of enacting conditional supermajority requirements. Specifically, the chancellor did not consider whether Gulton\u27s conditional supermajority provision would adequately protect shareholders\u27 interests to the extent they conflict with management\u27s interests. By dismissing the complaint, the Seibert court failed to consider whether the use of conditional supermajority provisions should be circumscribed by the courts in order to make such measures responsive to the needs of shareholders. This note examines alternatives to dismissal of the plaintiff\u27s complaint and recommends that corporate management be required to disclose the purposes and effects of conditional supermajority provisions when proposing them to shareholders for adoption

    Obituary - Neil Henderson

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    Error Recognition in Calculus Problems: What Characterizes Expertise?

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    Previous research in the area of expert-novice comparisons of mathematical problem solving has focused on the differences in categorization of and performance on math problems. These studies have led to the conclusion that while solving or categorizing problems, experts focus on deep processing and novices focus on surface structure. Other research dealing with true/false multiplication equations has shown that adults (considered experts in multiplication) can reject false answers before processing the equation. This study attempts to extend these findings by looking at the differences between experts and novices in the recognition of errors in true/false calculus verification expressions. The participants were professors (experts) and students (novices). The experiment consisted of participants answering 68 true/false calculus expressions (equations or conditionals) at three levels of difficulty. Reaction time, accuracy, and level of confidence were recorded. Experts were found to be quicker and more accurate overall. The experts were not able to reject the false problems more quickly than accepting the true ones. However, there was still some support for the hypothesis that experts are not only quantitatively better at task performance, but qualitatively different from novices in the type of processing they employ

    Physical Fitness of Police Cadets: Baseline Characteristics and Changes during A 16-Week Academy

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    Police academies traditionally emphasize the importance of being physically fit. The purpose of this research was to determine cadet baseline physical fitness characteristics and assess effectiveness of a 16-week training program. Sixty-eight cadets (61 men, 7 women) volunteered to have baseline physical fitness characteristics assessed, and 55 cadets (49 men, 6 women) completed further testing at weeks 8 and 16. The testing comprised hand grip (strength), arm crank (upper-body power), 30 seconds Wingate (lower body power), sum of skinfolds and percentage body fat (body composition), 40-yard dash (sprint speed), 1 repetition maximum bench press (strength), T-test (agility), and sit-and-reach (flexibility). In addition, cadets completed standardized state testing (push-ups, sit-ups, vertical jump, and half-mile shuttle run). The training program consisted of 1 hour sessions, 3 dĀ·wk, including aerobic, plyometrics, body weight, and resistance exercise. Significant changes were found in agility (p \u3c 0.01), upper-body and lower-body peak power (p ā‰¤ 0.05), sit-ups (p \u3c 0.01), push-ups (p ā‰¤ 0.05) across the first 8 weeks, and in agility (p ā‰¤ 0.05), lower-body peak power (p ā‰¤ 0.05), sit-ups (p \u3c 0.01), push-ups (p ā‰¤ 0.05), half-mile shuttle run (p \u3c 0.01) across the full 16 weeks. However, none of the variables showed significant change across the second half of the program (weeks 8-16). A number of individual parameters of physical fitness showed evidence of improvement in the first 8 weeks, whereas none of the variables showed significant improvement in the second 8 weeks. This suggests modifications could be made to increase overall effectiveness of cadet physical training specifically after the 8-week mark

    The Seventh Annual National Conference of Black Physics Students

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    The National Conference of Black Physics Students began in 1986 when several Black physics graduate students at MIT and Harvard decided to address the 'pipeline problem' of African Americans in physics by organizing a conference for Black physics undergraduates. The goals of the conference were: (1) to develop a network within the Black physics community, (2) to make Black students in physics, particularly at graduate level, aware of academic and professional opportunities and (3) to bring important issues and developments in the field to the attention of these students. We are pleased to announce the Seventh Annual National Conference of Black Physics Students held February 12 and 13, 1993 served the largest population of students so far. The largest conference previous to this one hosted 150 students. We registered and prepared for 240 students with 210 actually attenting. We received so many qualified abstracts for technical talks by students that instead of NCBPS's tradition of 3-4 student presentations, we ran 4 parallel sessions in different rooms with 4-5 presentations in each room. In response to comments from previous conferences, the program contained 3 workshop/discussion sessions. The topics for the interactive discussion workshops were: 'Getting Ready for Graduate School,' 'How to Succeed in Graduate School,' and 'Issues Facing Black Scientists.
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