Some effects of insect hormones on Na(^+), K(^+)-ATPase and fluid secretion by the malpighian tubules of locusta migratoria L

A study has been made on the effects of insect hormones on fluid secretion by the Malpighian tubules of Locusta, and on the Na(^+), K(^+)- ATPase activity in microsomal preparations of the tubules. A diuretic hormone present in extracts of the neurosecretory cells and corpora cardiaca accelerated rates of fluid secretion by in vitro preparations of the tubules but had no effect on ATPase activity. Ecdysone affected neither secretory rates nor enzyme activity whereas Juvenile Hormone had an inhibitory effect on both. Attempts have been made to explain how. J.H. may inhibit Na(^+), K(^+) -ATPase activity. It is possible that J.H. affects the membrane conformation and thus prevents the normal reaction sequence of the ATPase. Ultrastructural studies have shown that the fine structure of the Malpighian tubules varies with development. Invaginations of the basal and apical cell membranes were found to develop with increasing age throughout the 5th stadium. At the same time the numbers of mitochondria in the tubule cells appeared to increase and the mitochondria came to lie in the cytoplasm of the basal infolds. Just prior to the larval-adult moult the invaginations of both membranes decreased and mitochondria were rarely found amongst the basal infolds. Associated with these ultrastructural changes, functional changes are also reported. Na(^+) , K(^+)-ATPase activity was low at the beginning and. end of the 5th stadium, times when there was least invagination of the plasma membrane. At the same times animal relative water content was high, suggesting lower rates of secretion. Both ouabain and ethacrynic acid were found to inhibit fluid secretion by, an. d Na(^+), K(^+)-ATPase, in microsomal preparations of the Malpighian tubules. Ouabain was the more effective inhibitor of enzyme activity ( pI(_50) = 5.8 as compared with ethacrynic acid pI(_50) = 2.5)

Laying the Groundwork for the TTI Impact Study: Purposes, Values, Concepts

This document is part of an ongoing cycle of writing and comment designed to help us imagine forward into the work of the new Scholarship and Tenure Policy Research Group (TTI-RG). Here we aim to set a tone, to create an ethos, and to begin to craft a shared language for participants. Our process, therefore, both models and seeks to inform the processes of policy change. We want to set before the Fellows a more precise framing of our principles and purposes. If the initial dialogues among the Fellows and organizational partners can establish agreement on the larger purposes and guiding concepts of our work, we will do a better job of establishing the impact of IA\u27s Tenure Team Initiative on Public Scholarship (TTI), and our subsequent recommendations will carry more force. We report here on the groundwork that we have been preparing since the planning for the Research Group, initially categorized as a TTI-RG, began in October 2010. We suggest principles and strategies that, refined through further conversation, should guide the research. Above all, we propose that the TTI-RG assess faculty rewards systems as dynamic elements in the larger set of co-dependent relationships among (1) diverse, engaged student bodies; (2) diverse, engaged faculties; and (3) diverse, engaged communities

Higher Education Exchange: 2006

This annual publication serves as a forum for new ideas and dialogue between scholars and the larger public. Essays explore ways that students, administrators, and faculty can initiate and sustain an ongoing conversation about the public life they share.The Higher Education Exchange is founded on a thought articulated by Thomas Jefferson in 1820: "I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."In the tradition of Jefferson, the Higher Education Exchange agrees that a central goal of higher education is to help make democracy possible by preparing citizens for public life. The Higher Education Exchange is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society.Working in this tradition, the Higher Education Exchange publishes interviews, case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies

Higher Education Exchange:2002

This annual publication serves as a forum for new ideas and dialogue between scholars and the larger public. Essays explore ways that students, administrators, and faculty can initiate and sustain an ongoing conversation about the public life they share.The Higher Education Exchange is founded on a thought articulated by Thomas Jefferson in 1820: "I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."In the tradition of Jefferson, the Higher Education Exchange agrees that a central goal of higher education is to help make democracy possible by preparing citizens for public life. The Higher Education Exchange is part of a movement to strengthen higher education's democratic mission and foster a more democratic culture throughout American society.Working in this tradition, the Higher Education Exchange publishes interviews, case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies

Risk stratification in pediatric low-grade glioma and glioneuronal tumor treated with radiation therapy: An integrated clinicopathologic and molecular analysis

BackgroundManagement of unresectable pediatric low-grade glioma and glioneuronal tumor (LGG/LGGNT) is controversial. There are no validated prognostic features to guide use of radiation therapy (RT). Our study aimed to identify negative prognostic features in patients treated with RT using clinicopathologic and molecular data and validate these findings in an external dataset.MethodsChildren with non-metastatic, biopsy-proven unresectable LGG/LGGNT treated with RT at a single institution between 1997 and 2017 were identified. Recursive partitioning analysis (RPA) was used to stratify patients into low- and high-risk prognostic groups based on overall survival (OS). CNS9702 data were used for validation.ResultsOne hundred and fifty patients met inclusion criteria. Median follow-up was 11.4 years. RPA yielded low- and high-risk groups with 10-year OS of 95.6% versus 76.4% (95% CI: 88.7%–98.4% vs 59.3%–87.1%, P = 0.003), respectively. These risk groups were validated using CNS9702 dataset (n = 48) (4-year OS: low-risk vs high-risk: 100% vs 64%, P < 0.001). High-risk tumors included diffuse astrocytoma or location within thalamus/midbrain. Low-risk tumors included pilocytic astrocytoma/ganglioglioma located outside of the thalamus/midbrain. In the subgroup with known BRAF status (n = 49), risk stratification remained prognostic independently of BRAF alteration (V600E or fusion). Within the high-risk group, delayed RT, defined as RT after at least one line of chemotherapy, was associated with a further decrement in overall survival (P = 0.021).ConclusionA high-risk subgroup of patients, defined by diffuse astrocytoma histology or midbrain/thalamus tumor location, have suboptimal long-term survival and might benefit from timely use of RT. These results require validation

Interrogating resilience: toward a typology to improve its operationalization

In the context of accelerated global change, the concept of resilience, with its roots in ecological theory and complex adaptive systems, has emerged as the favored framework for understanding and responding to the dynamics of change. Its transfer from ecological to social contexts, however, has led to the concept being interpreted in multiple ways across numerous disciplines causing significant challenges for its practical application. The aim of this paper is to improve conceptual clarity within resilience thinking so that resilience can be interpreted and articulated in ways that enhance its utility and explanatory power, not only theoretically but also operationally. We argue that the current confusion and ambiguity within resilience thinking is problematic for operationalizing the concept within policy making. To achieve our aim, we interrogate resilience interpretations used within a number of academic and practice domains in the forefront of contending with the disruptive and sometimes catastrophic effects of global change (primarily due to climate change) on ecological and human-nature systems. We demonstrate evolution and convergence among disciplines in the interpretations and theoretical underpinnings of resilience and in engagement with cross-scale considerations. From our analysis, we identify core conceptual elements to be considered in policy responses if resilience is to fulfill its potential in improving decision making for change. We offer an original classification of resilience definitions in current use and a typology of resilience interpretations. We conclude that resilience thinking must be open to alternative traditions and interpretations if it is to become a theoretically and operationally powerful paradigm

Is race medically relevant? A qualitative study of physicians' attitudes about the role of race in treatment decision-making

<p>Abstract</p> <p>Background</p> <p>The role of patient race in medical decision-making is heavily debated. While some evidence suggests that patient race can be used by physicians to predict disease risk and determine drug therapy, other studies document bias and stereotyping by physicians based on patient race. It is critical, then, to explore physicians' attitudes regarding the medical relevance of patient race.</p> <p>Methods</p> <p>We conducted a qualitative study in the United States using ten focus groups of physicians stratified by self-identified race (black or white) and led by race-concordant moderators. Physicians were presented with a medical vignette about a patient (whose race was unknown) with Type 2 diabetes and untreated hypertension, who was also a current smoker. Participants were first asked to discuss what medical information they would need to treat the patient. Then physicians were asked to explicitly discuss the importance of race to the hypothetical patient's treatment. To identify common themes, codes, key words and physician demographics were compiled into a comprehensive table that allowed for examination of similarities and differences by physician race. Common themes were identified using the software package NVivo (QSR International, v7).</p> <p>Results</p> <p>Forty self-identified black and 50 self-identified white physicians participated in the study. All physicians - regardless of their own race - believed that medical history, family history, and weight were important for making treatment decisions for the patient. However, black and white physicians reported differences in their views about the relevance of race. Several black physicians indicated that patient race is a central factor for choosing treatment options such as aggressive therapies, patient medication and understanding disease risk. Moreover, many black physicians considered patient race important to understand the patient's views, such as alternative medicine preferences and cultural beliefs about illness. However, few white physicians explicitly indicated that the patient's race was important over-and-above medical history. Instead, white physicians reported that the patient should be treated aggressively regardless of race.</p> <p>Conclusions</p> <p>This investigation adds to our understanding about how physicians in the United States consider race when treating patients, and sheds light on issues physicians face when deciding the importance of race in medical decision-making.</p