1,911 research outputs found

    Value Added: Best Practices For The Utilization Of Assistant Principals' Skills And Knowledge In Schools

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    There are many demands on schools today to perform at a high level with competence that improves teaching and learning and promotes higher student achievement. When students perform below national standards, schools may be given a “no vote of confidence” from the public. Therefore, principals in schools need to find ways to groom and utilize the talents of assistant principals in a broader capacity. The assistant principal is the individual who should work closely with the principal to handle management and instructional matters within the school. Too many school districts today have principals who continue to under utilize the strong talents, skills, knowledge of the assistant principal (Bolman & Terrence, 2002). Typical uses of an assistant principal in too many schools include being on hall, bus, recess, and cafeteria duty and handling of student discipline on a daily basis. Some assistant principals bring to the school setting skills and knowledge related to broader practices for improving instruction and management in schools. In order to help create and maintain effective schools, there should be identified ways to improve the use of assistant principals’ skills and knowledge that could impact teaching and learning. A central part of being a great school leader is to cultivate the leadership skills of others, especially the assistant principal (Darling-Hammond, 2007). The purpose of this study is to discuss the contemporary role of today’s assistant principals including getting to know the assistant principal, value in shared leadership, developing the assistant principal’s leadership skills, use of technology, and the professional learning community. The benefits of this study hopefully will remind principals and school leaders to assess the skills and knowledge that the assistant principal brings to the school setting and to utilize those talents for improving school performance. The effective principal will also continue to provide opportunities for leadership development and engagement for the assistant principal in meaningful ways that support strong instructional leadership

    Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT

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    Cortical neurons are frequently tuned to several stimulus dimensions, and many cortical areas contain intercalated maps of multiple variables. Relatively little is known about how information is “read out” of these multidimensional maps. For example, how does an organism extract information relevant to the task at hand from neurons that are also tuned to other, irrelevant stimulus dimensions? We addressed this question by employing microstimulation techniques to examine the contribution of disparity-tuned neurons in the middle temporal (MT) visual area to performance on a direction discrimination task. Most MT neurons are tuned to both binocular disparity and the direction of stimulus motion, and MT contains topographic maps of both parameters. We assessed the effect of microstimulation on direction judgments after first characterizing the disparity tuning of each stimulation site. Although the disparity of the stimulus was irrelevant to the required task, we found that microstimulation effects were strongly modulated by the disparity tuning of the stimulated neurons. For two of three monkeys, microstimulation of nondisparity-selective sites produced large biases in direction judgments, whereas stimulation of disparity-selective sites had little or no effect. The binocular disparity was optimized for each stimulation site, and our result could not be explained by variations in direction tuning, response strength, or any other tuning property that we examined. When microstimulation of a disparity-tuned site did affect direction judgments, the effects tended to be stronger at the preferred disparity of a stimulation site than at the nonpreferred disparity, indicating that monkeys can selectively monitor direction columns that are best tuned to an appropriate conjunction of parameters. We conclude that the contribution of neurons to behavior can depend strongly upon tuning to stimulus dimensions that appear to be irrelevant to the current task, and we suggest that these findings are best explained in terms of the strategy used by animals to perform the task

    Orbitofrontal Cortex Value Signals Depend on Fixation Location during Free Viewing

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    In the natural world, monkeys and humans judge the economic value of numerous competing stimuli by moving their gaze from one object to another, in a rapid series of eye movements. This suggests that the primate brain processes value serially, and that value-coding neurons may be modulated by changes in gaze. To test this hypothesis, we presented monkeys with value-associated visual cues and took the unusual step of allowing unrestricted free viewing while we recorded neurons in the orbitofrontal cortex (OFC). By leveraging natural gaze patterns, we found that a large proportion of OFC cells encode gaze location and, that in some cells, value coding is amplified when subjects fixate near the cue. These findings provide the first cellular-level mechanism for previously documented behavioral effects of gaze on valuation and suggest a major role for gaze in neural mechanisms of valuation and decision-making under ecologically realistic conditions

    Orbitofrontal Cortex Value Signals Depend on Fixation Location during Free Viewing

    Get PDF
    In the natural world, monkeys and humans judge the economic value of numerous competing stimuli by moving their gaze from one object to another, in a rapid series of eye movements. This suggests that the primate brain processes value serially, and that value-coding neurons may be modulated by changes in gaze. To test this hypothesis, we presented monkeys with value-associated visual cues and took the unusual step of allowing unrestricted free viewing while we recorded neurons in the orbitofrontal cortex (OFC). By leveraging natural gaze patterns, we found that a large proportion of OFC cells encode gaze location and, that in some cells, value coding is amplified when subjects fixate near the cue. These findings provide the first cellular-level mechanism for previously documented behavioral effects of gaze on valuation and suggest a major role for gaze in neural mechanisms of valuation and decision-making under ecologically realistic conditions

    Association of Self-Efficacy and Self-Regulation with Nutrition and Exercise Behaviors in a Community Sample of Adults

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    This study examined the association of self-efficacy and self-regulation with nutrition and exercise behaviors. The study used a cross-sectional design and included 108 participants (54 men, 54 women). Nutrition behaviors (fruit/vegetable consumption, dinner cooking, and restaurant eating) and exercise were measured using total days in last week a behavior was reported. Instruments measuring self-efficacy and self-regulation demonstrated excellent Cronbach’s alphas (.93–.95). Path analysis indicated only fruit/vegetable consumption and exercise were associated with self-efficacy and self-regulation. Self-regulation showed direct association with fruit/vegetable consumption and exercise, but self-efficacy had direct association only with exercise. Self-efficacy and self-regulation should be strategically used to promote health behaviors

    Development of an invasively monitored porcine model of acetaminophen-induced acute liver failure

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    Background: The development of effective therapies for acute liver failure (ALF) is limited by our knowledge of the pathophysiology of this condition, and the lack of suitable large animal models of acetaminophen toxicity. Our aim was to develop a reproducible invasively-monitored porcine model of acetaminophen-induced ALF. Method: 35kg pigs were maintained under general anaesthesia and invasively monitored. Control pigs received a saline infusion, whereas ALF pigs received acetaminophen intravenously for 12 hours to maintain blood concentrations between 200-300 mg/l. Animals surviving 28 hours were euthanased. Results: Cytochrome p450 levels in phenobarbital pre-treated animals were significantly higher than non pre-treated animals (300 vs 100 pmol/mg protein). Control pigs (n=4) survived 28-hour anaesthesia without incident. Of nine pigs that received acetaminophen, four survived 20 hours and two survived 28 hours. Injured animals developed hypotension (mean arterial pressure; 40.8+/-5.9 vs 59+/-2.0 mmHg), increased cardiac output (7.26+/-1.86 vs 3.30+/-0.40 l/min) and decreased systemic vascular resistance (8.48+/-2.75 vs 16.2+/-1.76 mPa/s/m3). Dyspnoea developed as liver injury progressed and the increased pulmonary vascular resistance (636+/-95 vs 301+/-26.9 mPa/s/m3) observed may reflect the development of respiratory distress syndrome. Liver damage was confirmed by deterioration in pH (7.23+/-0.05 vs 7.45+/-0.02) and prothrombin time (36+/-2 vs 8.9+/-0.3 seconds) compared with controls. Factor V and VII levels were reduced to 9.3 and 15.5% of starting values in injured animals. A marked increase in serum AST (471.5+/-210 vs 42+/-8.14) coincided with a marked reduction in serum albumin (11.5+/-1.71 vs 25+/-1 g/dL) in injured animals. Animals displayed evidence of renal impairment; mean creatinine levels 280.2+/-36.5 vs 131.6+/-9.33 mumol/l. Liver histology revealed evidence of severe centrilobular necrosis with coagulative necrosis. Marked renal tubular necrosis was also seen. Methaemoglobin levels did not rise >5%. Intracranial hypertension was not seen (ICP monitoring), but there was biochemical evidence of encephalopathy by the reduction of Fischer's ratio from 5.6 +/- 1.1 to 0.45 +/- 0.06. Conclusion: We have developed a reproducible large animal model of acetaminophen-induced liver failure, which allows in-depth investigation of the pathophysiological basis of this condition. Furthermore, this represents an important large animal model for testing artificial liver support systems

    External Aortic Root Support to Prevent Aortic Dilatation in Patients With Marfan Syndrome

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    Background: Personalized external aortic root support (PEARS) was introduced in 2004 for prevention of aortic root dilatation in Marfan patients. The individual's aortic root is replicated by 3-dimensional printing. A polymer mesh sleeve is manufactured, which is implanted with the aim to support and stabilize the aortic wall. / Objectives: The aim of this study was to assess effectiveness of PEARS for prevention of aortic root dilatation in Marfan patients. / Methods: A total of 24 consecutive Marfan patients operated 2004 to 2012 were prospectively monitored with magnetic resonance imaging. Following a pre-defined protocol, baseline and follow-up aorta measurements were made in a blinded random sequence. / Results: The mean age of the patients was 33 ± 13.3 years (range: 16 to 58 years), and the mean aortic root diameter was 45 ± 2.8 mm (range: 41 to 52 mm). Follow-up was 6.3 ± 2.6 years. There was no increase in the aortic root and ascending aorta diameters, but there was a tendency toward reduction: annulus diameter 28.9 ± 2.3 mm to 28.5 ± 2.4 mm (change −0.39 mm, 95% confidence interval [CI]: −1.05 to 0.27 mm), sinus of Valsalva diameter 44.9 ± 2.9 mm to 44.5 ± 3.0 mm (change −0.37 mm, 95% CI: −1.23 to 0.51 mm), and ascending aorta diameter 32.4 ± 3.6 mm to 32.3 ± 3.7 mm (change −0.10 mm, 95% CI: −0.92 to 0.74 mm). In the same period, the descending aorta diameter increased from 22.9 ± 2.4 mm to 24.2 ± 3.0 mm (change 1.32 mm, 95% CI: 0.70 to 1.94 mm; p < 0.001) with a tendency toward increase in aortic arch diameter 24.1 ± 2.0 mm to 24.5 ± 2.8 mm (change 0.41 mm, 95% CI: −0.56 to 1.37 mm). / Conclusions: PEARS is effective in stabilizing the aortic root and preventing its dilatation. It is a viable alternative for prevention of aortic root dissection in Marfan patients

    The structural invisibility of outsiders: the role of migrant labour in the meat-processing industry

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    This article examines the role of migrant workers in meat-processing factories in the UK. Drawing on materials from mixed methods research in a number of case study towns across Wales, we explore the structural and spatial processes that position migrant workers as outsiders. While state policy and immigration controls are often presented as a way of protecting migrant workers from work-based exploitation and ensuring jobs for British workers, our research highlights that the situation ‘on the ground’ is more complex. We argue that ‘self-exploitation’ among the migrant workforce is linked to the strategies of employers and the organisation of work, and that hyper-flexible work patterns have reinforced the spatial and social invisibilities of migrant workers in this sector. While this creates problems for migrant workers, we conclude that it is beneficial to supermarkets looking to supply consumers with the regular supply of cheap food to which they have become accustomed

    A36-dependent actin filament nucleation promotes release of vaccinia virus

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    Cell-to-cell transmission of vaccinia virus can be mediated by enveloped virions that remain attached to the outer surface of the cell or those released into the medium. During egress, the outer membrane of the double-enveloped virus fuses with the plasma membrane leaving extracellular virus attached to the cell surface via viral envelope proteins. Here we report that F-actin nucleation by the viral protein A36 promotes the disengagement of virus attachment and release of enveloped virus. Cells infected with the A36YdF virus, which has mutations at two critical tyrosine residues abrogating localised actin nucleation, displayed a 10-fold reduction in virus release. We examined A36YdF infected cells by transmission electron microscopy and observed that during release, virus appeared trapped in small invaginations at the plasma membrane. To further characterise the mechanism by which actin nucleation drives the dissociation of enveloped virus from the cell surface, we examined recombinant viruses by super-resolution microscopy. Fluorescently-tagged A36 was visualised at sub-viral resolution to image cell-virus attachment in mutant and parental backgrounds. We confirmed that A36YdF extracellular virus remained closely associated to the plasma membrane in small membrane pits. Virus-induced actin nucleation reduced the extent of association, thereby promoting the untethering of virus from the cell surface. Virus release can be enhanced via a point mutation in the luminal region of B5 (P189S), another virus envelope protein. We found that the B5P189S mutation led to reduced contact between extracellular virus and the host membrane during release, even in the absence of virus-induced actin nucleation. Our results posit that during release virus is tightly tethered to the host cell through interactions mediated by viral envelope proteins. Untethering of virus into the surrounding extracellular space requires these interactions be relieved, either through the force of actin nucleation or by mutations in luminal proteins that weaken these interactions. © 2013 Horsington et al
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