954 resultados para Clark, Andrea (Wendy)


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Change in 4,119 students' freshman to senior ratings of four educational philosophies (vocational, academic, collegiate, and nonconformist) provided four measures of educational impact. Repeated measures analyses of variance compared changes in philosophy as a function of Greek affiliation, controlling for sex, historical era, major, parents' education, scholastic aptitude, and academic motivation. Small but significantly different degrees of change in the collegiate and nonconformist philosophies suggested that Greek affiliation increased social interests and inhibited some forms of intellectual interests. These small differences across all students masked the moderating effect of major. In the nonconformist philosophy, for example, the Greek × major interaction reflected substantial Greek–independent differences among humanities majors, and progressively smaller differences or reversals among social science, physical science, and engineering majors. Possible interpretations of this interaction are offered.

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In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

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BACKGROUND: Low tissue oxygen tension is an important factor leading to the development of wound dehiscence and anastomotic leakage after colon surgery. We tested whether supplemental fluid and supplemental oxygen can increase tissue oxygen tension in healthy and injured, perianastomotic, and anastomotic colon in an acutely instrumented pig model of anastomosis surgery. METHODS: Sixteen Swiss Landrace pigs were anesthetized (isoflurane 0.8%-1%) and their lungs ventilated. The animals were randomly assigned to low fluid treatment ("low" group, 3 mL x kg(-1) x h(-1) lactated Ringer's solution) or high fluid treatment ("high" group, 10 mL/kg bolus, 18 mL x kg(-1) x h(-1) lactated Ringer's solution) during colon anastomosis surgery and a subsequent measurement period (4 h). Two-and-half hours after surgery, tissue oxygen tension was recorded for 30 min during ventilation with 30% oxygen. Three hours after surgery, the animals' lungs were ventilated with 100% oxygen for 60 min. Tissue oxygen tension was recorded in the last 30 min. Tissue oxygen tension was measured with polarographic Clark-type electrodes, positioned in healthy colonic wall, close (2 cm) to the anastomosis, and in the anastomosis. RESULTS: In every group, tissue oxygen tension during ventilation with 100% oxygen was approximately twice as high as during ventilation with 30% oxygen, a statistically significant result. High or low volume crystalloid fluid treatment had no effect on colon tissue oxygen tension. CONCLUSIONS: Supplemental oxygen, but not supplemental crystalloid fluid, increased tissue oxygen tension in healthy, perianastomotic, and anastomotic colon tissue.

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INTRODUCTION: Perioperative hypovolemia arises frequently and contributes to intestinal hypoperfusion and subsequent postoperative complications. Goal-directed fluid therapy might reduce these complications. The aim of this study was to compare the effects of goal-directed administration of crystalloids and colloids on the distribution of systemic, hepatosplanchnic, and microcirculatory (small intestine) blood flow after major abdominal surgery in a clinically relevant pig model. METHODS: Twenty-seven pigs were anesthetized and mechanically ventilated and underwent open laparotomy. They were randomly assigned to one of three treatment groups: the restricted Ringer lactate (R-RL) group (n = 9) received 3 mL/kg per hour of RL, the goal-directed RL (GD-RL) group (n = 9) received 3 mL/kg per hour of RL and intermittent boluses of 250 mL of RL, and the goal-directed colloid (GD-C) group (n = 9) received 3 mL/kg per hour of RL and boluses of 250 mL of 6% hydroxyethyl starch (130/0.4). The latter two groups received a bolus infusion when mixed venous oxygen saturation was below 60% ('lockout' time of 30 minutes). Regional blood flow was measured in the superior mesenteric artery and the celiac trunk. In the small bowel, microcirculatory blood flow was measured using laser Doppler flowmetry. Intestinal tissue oxygen tension was measured with intramural Clark-type electrodes. RESULTS: After 4 hours of treatment, arterial blood pressure, cardiac output, mesenteric artery flow, and mixed oxygen saturation were significantly higher in the GD-C and GD-RL groups than in the R-RL group. Microcirculatory flow in the intestinal mucosa increased by 50% in the GD-C group but remained unchanged in the other two groups. Likewise, tissue oxygen tension in the intestine increased by 30% in the GD-C group but remained unchanged in the GD-RL group and decreased by 18% in the R-RL group. Mesenteric venous glucose concentrations were higher and lactate levels were lower in the GD-C group compared with the two crystalloid groups. CONCLUSIONS: Goal-directed colloid administration markedly increased microcirculatory blood flow in the small intestine and intestinal tissue oxygen tension after abdominal surgery. In contrast, goal-directed crystalloid and restricted crystalloid administrations had no such effects. Additionally, mesenteric venous glucose and lactate concentrations suggest that intestinal cellular substrate levels were higher in the colloid-treated than in the crystalloid-treated animals. These results support the notion that perioperative goal-directed therapy with colloids might be beneficial during major abdominal surgery.

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Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.

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Writing center scholarship and practice have approached how issues of identity influence communication but have not fully considered ways of making identity a key feature of writing center research or practice. This dissertation suggests a new way to view identity -- through an experience of "multimembership" or the consideration that each identity is constructed based on the numerous community memberships that make up that identity. Etienne Wenger (1998) proposes that a fully formed identity is ultimately impossible, but it is through the work of reconciling memberships that important individual and community transformations can occur. Since Wenger also argues that reconciliation "is the most significant challenge" for those moving into new communities of practice (or, "engage in a process of collective learning in a shared domain of human endeavor" (4)), yet this challenge often remains tacit, this dissertation examines and makes explicit how this important work is done at two different research sites - a university writing center (the Michigan Tech Multiliteracies Center) and at a multinational corporation (Kimberly-Clark Corporation). Drawing extensively on qualitative ethnographic methods including interview transcriptions, observations, and case studies, as well as work from scholars in writing center studies (Grimm, Denney, Severino), literacy studies (New London Group, Street, Gee), composition (Horner and Trimbur, Canagarajah, Lu), rhetoric (Crowley), and identity studies (Anzaldua, Pratt), I argue that, based on evidence from the two sites, writing centers need to educate tutors to not only take identity into consideration, but to also make individuals' reconciliation work more visible, as it will continue once students and tutors leave the university. Further, as my research at the Michigan Tech Multiliteracies Center and Kimberly-Clark will show, communities can (and should) change their practices in ways that account for reconciliation work as identity, communication, and learning are inextricably bound up with one another.

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The Golden Messenger Mine which is approximately twenty-three miles northeast of Helena, Montana, near York, on Trout Creek, has long presented several problems of both theoretical and practical interest.

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This thesis is concerned with the beneficiation of an oxidized lead ore. Emphasis was placed upon concentration by flotation rather than by gravity methods, although some investigation was made with the Wilfley shaking table. The concentration of lead minerals received most consideration in the problem, but wherever possible attempts were made to increase the silver and gold concentration along with the lead.

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Andrea Memmo ist in der Geschichte der Architekturtheorie vor allem deswegen bekannt, weil er durch die Veröffentlichung der 'Elementi d'architettura lodoliana, ossia l'arte del fabricare con solidità scientifica e con eleganza non capricciosa' (Rom 1786) entscheidend dazu beigetragen hat, die originellen architektonischen Konzepte der Nachwelt zu überliefern, die der venezianische Franziskaner Carlo Lodoli zwischen 1730 und 1750 mündlich verbreitet hatte. Der vorliegende Beitrag unternimmt es, anhand des bislang für verloren gehaltenen 'Piano Accademico', den Memmo um 1767 für die venezianische Akademie zum Zwecke der Unterrichtsreform der bildenden Künste (Skulptur, Malerei und Architektur) ausgearbeitet hatte, klarzustellen, welche wichtige Rolle der Aufenthalt in Rom für Memmo gespielt hat. Dies wird auch durch die Briefe belegt, die er während der Ausarbeitung seines Werkes über Lodoli verfasst hatte. Im Rom der 1780er Jahre waren für ihn ausschlaggebend 1. die Beziehungen zur dortigen Accademia di S. Luca und 2. seine Freundschaft zum spanische Botschafter José Nicolas de Azara. Azara hatte ihn dazu ermutigt, über den Padre Lodoli zu schreiben, um dessen Gedanken denen des mit Azara befreundeten Francesco Milizia gegenüberzustellen.