3,753 research outputs found
Exploratory talk within collaborative small groups in mathematics
No full textThis report describes one aspect of a wider research study on exploratory talk within collaborative small groups in secondary mathematics lessons. It outlines students’ views of using collaborative activity to learn mathematics. The fuller research study explores the extent to which exploratory talk occurs in collaborative peer groups in secondary mathematics classrooms
sj-pdf-1-vdi-10.1177_10406387221107898 – Supplemental material for OLIG2 immunolabeling in feline ependymoma
No full textSupplemental material, sj-pdf-1-vdi-10.1177_10406387221107898 for OLIG2 immunolabeling in feline ependymoma by Elena A. Demeter, Marc Kent, Eric N. Glass, Daniel R. Rissi, John Edwards and Andrew D. Miller in Journal of Veterinary Diagnostic Investigation</p
The Effects of thyroid medication on bone mineral density: a Study of Women’s Health Across the Nation (SWAN) pharmacoepidemiology study
No full textBackground: As women progress through menopause, bone mineral density (BMD) slowly decreases due to estrogen loss. Several studies suggest that medications taken for hypothyroidism do not have a significant effect in the rate of BMD loss while others suggest that thyroid medication could decrease BMD and increase the risk of fractures, osteoarthritis and osteoporosis.
Objective: To determine if women who initiate thyroid medication for hypothyroidism experience an increase loss in BMD at the femoral neck (FN), hip or spine compared to non -initiators.
Methods: We investigated changes in BMD associated with new use of thyroid hormone therapy in a prospective longitudinal cohort of mid-life women. BMD and medication use were measured annually over a period of 16-years. Propensity score matching (PS) was applied to balance baseline characteristics of women who did and did not initiate thyroid medications. Mixed model regression was used to examine annualized change in BMD. Covariates with a known impact on bone health (age, race, body mass index (BMI), menopausal status, thiazide diuretic and hormone use) were included in all models.
Results: Our cohort included 356 women (n=178 in each group) with a mean age of 52.9 (SD=5.6) years and BMI of 29.4 (SD=6.8). 64.3 % of the women were Caucasian, 19.9% African American, 9.6% Chinese and 6.2% Japanese. Median follow-up time was 9.5 years. After adjusting for the variables mentioned above, the annual rate of bone loss at the FN, hip and spine for the treatment and control groups were FN (- 0.71% vs. – 0.85% p= 0.22), hip (-0.57% vs -0.66% p=0.47), and spine (-0.59 vs -0.71% p=0.41).
Conclusion: After employing a pharmacoepidemiology design and PS matching there were no significant differences in BMD between those who used thyroid medications and those who did not at either the FN, total hip, or spine.
Public Health Significance: The findings in this study will help women who are using thyroid hormone therapy during the menopausal transition know that it does not affect their risk of developing osteoporosis or bone loss. The results of this study can help inform clinicians to better focus their time in known variables that effect BMD loss such as thiazide diuretics, body mass index, smoking status, and diabetes. This information will help doctors better educate patients on preventative measures that can help decrease the rate of bone loss through the menopausal transition
Edwin Edwards: A study in ethos
No full textIn November 1971, Edwin Edwards entered the final stages of his bid for the Louisiana governorship. Leading a long list of contenders in the fall democratic primaries and emerging as party victor in the December elections, Edwards seems the most promising candidate for the highest state office. The "Cajun Congressman" possesses an extraordinarily high level of ethos with men and women of widely varying ages and occupational categories. The sixteen-year veteran of politics has never lost an election; if he dominates in the February contest, he will be the first south Louisianian in thirty years to inhabit the governor"s mansion. Edwin Edwards claims that the major vehicle that he has used in building his image has been the good-will speech. His role as U. S. Congress man gave him the opportunity to use this medium to reach his bayou state constituency. Almost two years ago when Edwards embarked on an active, albeit unannounced, gubernatorial campaign, the author began this study in an attempt to answer the question- "What factors explain the ethical appeal of Edwin Edwards, Louisiana congressman, in his good-will speechmaking, 1968-1970?", Discovering the answer to this question involved taking three major steps- (1) Part one of the thesis describes the general nature of the good-will speaking of the Congressman, evaluates Edwards in the role of the good-will speaker, and examines a seven-month schedule of Edwards" occasional speechmaking. A knowledge of the specific environment within which Edwards acted out his role and built his ethos is preliminary to an under standing of the specific factors within that environment that account for his success. (2) Part two consists of a detailed description of several specific instances demonstrate the nature of audience responses to the Congressman; general press and interview commentaries concerning Edwards" appeal as a speaker; and a content analysis of interviews with individual members, illustrating opinions of Edwards as a speaker. This section is an attempt to prove that Edwards does indeed enjoy an unusually high level of ethos. (3) Part three is a critical search for the bases of Edwards" ethical appeal, involving examination of biographical data on Edwards; comments by press personnel and political associates; statements by members of the audiences at several of the speaking occasions; self-analysis of the speaker; a study of one speech in the context of the total environment in which Edwards delivered it; and texts of good-will speeches delivered in the past.Communication, Jack J. Valenti School o
Morphologic and functional correlates of synaptic pathology in the cathepsin D knockout mouse model of congenital neuronal ceroid lipofuscinosis
No full textMutations in the cathepsin D (CTSD) gene cause an aggressive neurodegenerative disease (congenital neuronal ceroid lipofuscinosis) that leads to early death. Recent evidence suggests that presynaptic abnormalities play a major role in the pathogenesis of CTSD deficiencies. To identify the early events that lead to synaptic alterations, we investigated synaptic ultrastructure and function in presymptomatic CTSD knockout (Ctsd) mice. Electron microscopy revealed that there were significantly greater numbers of readily releasable synaptic vesicles present in Ctsd mice than in wild-type control mice as early as postnatal day 16. The size of this synaptic vesicle pool continued to increase with disease progression in the hippocampus and thalamus of the Ctsd mice. Electrophysiology revealed a markedly decreased frequency of miniature excitatory postsynaptic currents (mEPSCs) with no effect on paired-pulse modulation of the evoked excitatory post synaptic potentials in the hippocampus of Ctsd mice. The reduced mEPSCs frequency was observed before the appearance of epilepsy or any morphologic sign of synaptic degeneration. Taken together, these data indicate that CTSD is required for normal synaptic function and that a failure in synaptic trafficking or recycling may bean early and important pathologic mechanism in Ctsd mice; these presynaptic abnormalities may initiate synaptic degeneration in advance of subsequent neuronal loss
Does the Current Account Matter?
No full textThe purpose of this paper is to investigate in detail the behavior of the current account in emerging economies, and in particular its role if any in financial crises. Models of current account behavior are reviewed, and a dynamic model of current account sustainability is developed. The empirical analysis is based on a massive data set that covers over 120 countries during more than 25 years. Important controversies related to the current account including the extent to which current account deficits help predict currency crises are also analyzed. Throughout the paper I am interested in analyzing whether there is evidence supporting the idea that there are costs involved in running 'very large' deficits. Moreover, I investigate the nature of these potential costs, including whether they are particularly high in the presence of other type of imbalances.
Experimental investigation into the propagation of partial discharge pulses in transformers
No full textAn experimental investigation into the propagation behaviour of partial discharge (PD) pulses in a continuous disc type 6.6kV transformer winding is described in this paper. PD pulses were injected into the winding using a calibrator and the resulting current signals at the line and neutral end terminals measured using wide band current transformers. The location of the troughs (or zeros) in the frequency spectra of the measured signals change in accordance with the position of the injected pulse. The crests (or poles) in the spectra convey information about the resonance frequencies of the winding and are not affected by the position of the injected pulse. The measured spectra are compared with the spectra generated by a simulation model and although differences exist the overall shape and location of the poles and zeros are similar
Contract Enforcement and Institutions among the Maghribi Traders: Refuting Edwards and Ogilvie
No full textEdwards and Ogilvie (2008) dispute the empirical basis for the view (Greif, e.g., 1989, 1994, 2006) that multilateral reputation mechanism mitigated agency problems among the eleventh-century Maghribi traders. They assert that the relations among merchants and agents were law-based. This paper refutes this assertion using quantitative and documentary evidence thereby vindicating the position that the legal system had a marginal role in mitigating agency problems in long-distance trade in this historical era.** Edwards and Ogilvie constantly present legal actions in non-trade related legal cases as evidence for a reliance on the legal system for matters pertaining to long-distance trade. Their criticism of Greif’s documentary analysis also fails scrutiny. The claim that merchants' relations with their overseas agents were law-based is wrong. This paper is based on quantitative analyses of the corpuses containing the hundreds of documents on which the literature relies and a careful review of the documents and the literature Edwards and Ogilvie cite. Their assertion is shown to be based on unrepresentative and irrelevant examples, an inaccurate description of the literature, and a consistent misreading of the few sources they consulted. In particular, their examples for the use of the court are mainly taken from mandatory legal procedures associated with sorting out the assets and liabilities of deceased traders’ estates. Such examples do not support the claim that agency relations were law-based. The quantitative analysis reveals that empirical basis for the multilateral reputation view is stronger than originally perceived. This paper also sheds light on the roles of the legal system and reputation mechanism during this period.
Seismic data reveal eastern Black Sea Basin structure
No full textRifted continental margins are formed by progressive extension of the lithosphere. The development of these margins plays an integral role in the plate tectonic cycle, and an understanding of the extensional process underpins much hydrocarbon exploration. A key issue is whether the lithosphere extends uniformly, or whether extension varies\ud
with depth. Crustal extension may be determined using seismic techniques. Lithospheric extension may be inferred from the waterloaded subsidence history, determined from\ud
the pattern of sedimentation during and after rifting. Unfortunately, however, many rifted margins are sediment-starved, so the subsidence history is poorly known.\ud
To test whether extension varies between the crust and the mantle, a major seismic experiment was conducted in February–March 2005 in the eastern Black Sea Basin (Figure 1), a deep basin where the subsidence history is recorded\ud
by a thick, post-rift sedimentary sequence. The seismic data from the experiment indicate the presence of a thick, low-velocity zone, possibly representing overpressured sediments. They also indicate that the basement and\ud
Moho in the center of the basin are both several kilometers shallower than previously inferred. These initial observations may have considerable impact on thermal models of the petroleum system in the basin. Understanding\ud
the thermal history of potential source rocks is key to reducing hydrocarbon exploration risk. The experiment, which involved collaboration between university groups in the United Kingdom, Ireland, and Turkey, and BP and\ud
Turkish Petroleum (TPAO), formed part of a larger project that also is using deep seismic reflection and other geophysical data held by the industry partners to determine the subsidence history and hence the strain evolution of\ud
the basin
Reviving the past : eighteenth-century evangelical interpretations of church history
No full textThis study addresses eighteenth-century English-speaking evangelicals' understandings of church history, through the lens of published attempts to represent preceding Christian centuries panoramically or comprehensively. Sources entail several short reflections on history emerging in the early years of the transatlantic Revival (1730s-1740s) and subsequent, more substantial efforts by evangelical leaders John Gillies, Jonathan Edwards, John Wesley, Joseph and Isaac Milner, and Thomas Haweis. Little scholarly analysis exists on these sources, aside from the renaissance of interest in recent decades in Edwards. This is surprising, considering the acknowledged prominence of history-writing in the eighteenth century and the influence attributed, then and now, to the works of authors such as Gibbon, Hume, and Robertson. The aim is, first, to elucidate each of the above evangelicals' interpretations of the Christian past, both in overview and according to what they said on a roster of particular historical events, people and movements, and then to consider shared and divergent aspects. These aspects range from points of detail to paradigmatic theological convictions. Secondarily, evangelical church histories are analyzed in relation to earlier Protestant as well as eighteenth-century 'enlightened' historiography, in part through attention to evangelical authors' explicit engagement with these currents. This contextualization assists in determining the unique qualities of evangelical interpretations. Is there, then, evidence of a characteristically 'evangelical' perspective on church history? An examination of this neglected area illumines patterns and particulars of evangelicals' historical thought, and these in turn communicate the self-perceptions and the defining features of evangelicalism itself. Findings support the primary contention that evangelical leaders made use of a dynamic pattern of revival and declension as a means of accounting for the full history of Christianity. Beyond displaying the central place of 'revival' for evangelicals, these church histories demonstrate evangelicalism‘s complex relationship—involving both receptivity and critique—with Protestant and Enlightenment currents of historical inquiry
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