unclear principal findings: Topics by Science.gov

Sample records for unclear principal findings

Principals' Perceptions of Teacher Attrition in Indiana Catholic Schools, Checking for Agreement with Ingersoll's Theoretical Framework on Teacher Attrition in Private Schools

ERIC Educational Resources Information Center

Brettnacher, Joseph A.

2012-01-01

Problem. Some Catholic schools report high teacher attrition rates. Understanding reasons for teacher attrition and responding to those issues is one of the many responsibilities of principals. However, it is unclear what Catholic principals understand about teacher attrition. Ingersoll's extensive research on teacher attrition has provided a…
Dynamic interneuron-principal cell interplay leads to a specific pattern of in vitro ictogenesis.

PubMed

Lévesque, Maxime; Chen, Li-Yuan; Hamidi, Shabnam; Avoli, Massimo

2018-07-01

Ictal discharges induced by 4-aminopyridine in the in vitro rodent entorhinal cortex present with either low-voltage fast or sudden onset patterns. The role of interneurons in initiating low-voltage fast onset ictal discharges is well established but the processes leading to sudden onset ictal discharges remain unclear. We analysed here the participation of interneurons (n = 75) and principal cells (n = 13) in the sudden onset pattern by employing in vitro tetrode wire recordings in the entorhinal cortex of brain slices from Sprague-Dawley rats. Ictal discharges emerged from a background of frequently occurring interictal spikes that were associated to a specific interneuron/principal cell interplay. High rates of interneuron firing occurred 12 ms before interictal spike onset while principal cells fired later during low interneuron firing. In contrast, the onset of sudden ictal discharges was characterized by increased firing from principal cells 627 ms before ictal onset whereas interneurons increased their firing rates 161 ms before ictal onset. Our data show that sudden onset ictogenesis is associated with frequently occurring interictal spikes resting on the interplay between interneurons and principal cells while ictal discharges stem from enhanced principal cell firing leading to increased interneuron activity. These findings indicate that specific patterns of interactions between interneurons and principal cells shape interictal and ictal discharges with sudden onset in the rodent entorhinal cortex. We propose that specific neuronal interactions lead to the generation of distinct onset patterns in focal epileptic disorders. Copyright © 2018 Elsevier Inc. All rights reserved.
Framing Social Justice Leadership in a University-Based Preparation Program: The University of California's Principal Leadership Institute

ERIC Educational Resources Information Center

Trujillo, Tina; Cooper, Robert

2014-01-01

Scholars are increasingly considering how theoretical concepts about social justice might permeate leadership preparation programs' design. Yet the degree to which these concepts actually anchor these programs is unclear. This article addresses this gap by analyzing how the University of California's Principal Leadership Institute bridges theory…
The Role of Teacher Leadership in How Principals Influence Classroom Instruction and Student Learning

ERIC Educational Resources Information Center

Sebastian, James; Allensworth, Elaine; Huang, Haigen

2016-01-01

School principals can play an important role in promoting teacher leadership by delegating authority and empowering teachers in ways that allow them influence in key organizational decisions and processes. However, it is unclear whether instruction and student learning are enhanced by promoting teacher influence in all aspects of school…
Inference for Environmental Intervention Studies using Principal Stratification

PubMed Central

Hackstadt, A. J.; Butz, Arlene M.; Williams, D’Ann L.; Diette, Gregory B.; Breysse, Patrick N.; Matsui, Elizabeth C.; Peng, Roger D.

2014-01-01

Previous research has found evidence of an association between indoor air pollution and asthma morbidity in children. Environmental intervention studies have been performed to examine the role of household environmental interventions in altering indoor air pollution concentrations and improving health. Previous environmental intervention studies have found only modest effects on health outcomes and it is unclear if the health benefits provided by environmental modification are comparable to those provided by medication. Traditionally, the statistical analysis of environmental intervention studies has involved performing two intention-to-treat analyses that separately estimate the effect of the environmental intervention on health and the effect of the environmental intervention on indoor air pollution concentrations. We propose a principal stratification (PS) approach to examine the extent to which an environmental intervention’s effect on health outcomes coincides with its effect on indoor air pollution. We apply this approach to data from a randomized air cleaner intervention trial conducted in a population of asthmatic children living in Baltimore, Maryland, USA. We find that amongst children for whom the air cleaner reduced indoor particulate matter concentrations, the intervention resulted in a meaningful improvement of asthma symptoms with an effect generally larger than previous studies have shown. A key benefit of using principal stratification in environmental intervention studies is that it allows investigators to estimate causal effects of the intervention for sub-groups defined by changes in the indoor air pollution concentration. PMID:25164949
Inference for environmental intervention studies using principal stratification.

PubMed

Hackstadt, Amber J; Matsui, Elizabeth C; Williams, D'Ann L; Diette, Gregory B; Breysse, Patrick N; Butz, Arlene M; Peng, Roger D

2014-12-10

Previous research has found evidence of an association between indoor air pollution and asthma morbidity in children. Environmental intervention studies have been performed to examine the role of household environmental interventions in altering indoor air pollution concentrations and improving health. Previous environmental intervention studies have found only modest effects on health outcomes and it is unclear if the health benefits provided by environmental modification are comparable with those provided by medication. Traditionally, the statistical analysis of environmental intervention studies has involved performing two intention-to-treat analyses that separately estimate the effect of the environmental intervention on health and the effect of the environmental intervention on indoor air pollution concentrations. We propose a principal stratification approach to examine the extent to which an environmental intervention's effect on health outcomes coincides with its effect on indoor air pollution. We apply this approach to data from a randomized air cleaner intervention trial conducted in a population of asthmatic children living in Baltimore, Maryland, USA. We find that among children for whom the air cleaner reduced indoor particulate matter concentrations, the intervention resulted in a meaningful improvement of asthma symptoms with an effect generally larger than previous studies have shown. A key benefit of using principal stratification in environmental intervention studies is that it allows investigators to estimate causal effects of the intervention for sub-groups defined by changes in the indoor air pollution concentration. Copyright © 2014 John Wiley & Sons, Ltd.
Symptom Dimensions in Two Samples of Africans Americans with Obsessive-Compulsive Disorder

PubMed Central

Williams, M. T.; Elstein, J.; Buckner, E.; Abelson, J.; Himle, J.

2012-01-01

Obsessive-compulsive disorder (OCD) is a leading cause of disability worldwide, however, there is a lack of research that includes African Americans, thus it is unclear whether findings about symptom dimensions can be generalized to this population. A sample of adult African Americans with OCD (N=74) was recruited at the University of Pennsylvania (Penn) and administered the Yale Brown Obsessive-Compulsive checklist (YBOCS) to better understand the phenomenology of OCD in African Americans. Frequencies of symptoms are reported and compared to findings from the National Survey of American Life (NSAL; N=54). A principal components analysis of YBOCS categories and items was performed on the Penn sample. A six-component solution was found, that included Contamination & Washing, Hoarding, Sexual Obsessions & Reassurance, Aggression & Mental Compulsions, Symmetry & Perfectionism, and Doubt & Checking, explaining 59.1% of the variance. Factors identified were similar to those of previous studies in primarily white samples. African Americans with OCD reported more contamination symptoms and were twice as likely to report excessive concerns with animals as European Americans with OCD. The results indicate the presence of cultural differences, which is consistent with findings among non-clinical samples. Implications of these findings are discussed. PMID:22708117
Validity of measurement of shear modulus by ultrasound shear wave elastography in human pennate muscle.

PubMed

Miyamoto, Naokazu; Hirata, Kosuke; Kanehisa, Hiroaki; Yoshitake, Yasuhide

2015-01-01

Ultrasound shear wave elastography is becoming a valuable tool for measuring mechanical properties of individual muscles. Since ultrasound shear wave elastography measures shear modulus along the principal axis of the probe (i.e., along the transverse axis of the imaging plane), the measured shear modulus most accurately represents the mechanical property of the muscle along the fascicle direction when the probe's principal axis is parallel to the fascicle direction in the plane of the ultrasound image. However, it is unclear how the measured shear modulus is affected by the probe angle relative to the fascicle direction in the same plane. The purpose of the present study was therefore to examine whether the angle between the principal axis of the probe and the fascicle direction in the same plane affects the measured shear modulus. Shear modulus in seven specially-designed tissue-mimicking phantoms, and in eleven human in-vivo biceps brachii and medial gastrocnemius were determined by using ultrasound shear wave elastography. The probe was positioned parallel or 20° obliquely to the fascicle across the B-mode images. The reproducibility of shear modulus measurements was high for both parallel and oblique conditions. Although there was a significant effect of the probe angle relative to the fascicle on the shear modulus in human experiment, the magnitude was negligibly small. These findings indicate that the ultrasound shear wave elastography is a valid tool for evaluating the mechanical property of pennate muscles along the fascicle direction.
Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor.

PubMed

Qiao, Yuan; Li, Qiang; Du, Hong-Yang; Wang, Qiao-Wei; Huang, Ye; Liu, Wei

2017-07-01

Accumulating evidence suggests that polycyclic aromatic hydrocarbons (PAH) which adsorbed on the surface of ambient air particulate matters (PM), are the major toxic compound to cause cardiovascular and respiratory diseases, even cancer. However, its detrimental effects on human skin cell remain unclear. Here, we demonstrated that SRM1649b, a reference urban dust material of PAH, triggers human skin cells aging through cell cycle arrest, cell growth inhibition and apoptosis. Principally, SRM1649b facilitated Aryl hydrocarbon receptor (AhR) translocated into nucleus, subsequently activated ERK/MAPK signaling pathway, and upregulated aging-related genes expression. Most important, we found that AhR antagonist efficiently revert the aging of skin cells. Thus our novel findings firstly revealed the mechanism of skin aging under PAH contamination and provided potential strategy for clinical application. Copyright © 2017. Published by Elsevier Inc.
Introducing genetic testing for cardiovascular disease in primary care: a qualitative study.

PubMed

Middlemass, Jo B; Yazdani, Momina F; Kai, Joe; Standen, Penelope J; Qureshi, Nadeem

2014-05-01

While primary care systematically offers conventional cardiovascular risk assessment, genetic tests for coronary heart disease (CHD) are increasingly commercially available to patients. It is unclear how individuals may respond to these new sources of risk information. To explore how patients who have had a recent conventional cardiovascular risk assessment, perceive additional information from genetic testing for CHD. Qualitative interview study in 12 practices in Nottinghamshire from both urban and rural settings. Interviews were conducted with 29 adults, who consented to genetic testing after having had a conventional cardiovascular risk assessment. Individuals' principal motivation for genetic testing was their family history of CHD and a desire to convey the results to their children. After testing, however, there was limited recall of genetic test results and scepticism about the value of informing their children. Participants dealt with conflicting findings from the genetic test, family history, and conventional assessment by either focusing on genetic risk or environmental lifestyle factors. In some participants, genetic test results appeared to reinforce healthy behaviour but others were falsely reassured, despite having an 'above-average' conventional cardiovascular risk score. Although genetic testing was acceptable, participants were unclear how to interpret genetic risk results. To facilitate healthy behaviour, health professionals should explore patients' understanding of genetic test results in light of their family history and conventional risk assessment.
Fear acquisition and extinction in offspring of mothers with anxiety and depressive disorders.

PubMed

Waters, Allison M; Peters, Rosie-Mae; Forrest, Kylee E; Zimmer-Gembeck, Melanie

2014-01-01

Maternal anxiety and depression are significant risk factors for the development of these disorders in offspring. The pathways through which risk is conferred remain unclear. This study examined fear acquisition and extinction in 26 children at high risk for emotional disorders by virtue of maternal psychopathology (n=14 with a mother with a principal anxiety disorder and n=12 with a mother with a principal unipolar depressive disorder) and 31 low risk controls using a discriminative Pavlovian conditioning procedure. Participants, aged between 7 and 14 years, completed 16 trials of discriminative conditioning of two geometric figures, with (CS+) and without (CS-) an aversive tone (US), followed by 8 extinction trials (4×CS+, 4×CS-). In the context of comparable discriminative conditioning, children of anxious mothers showed larger skin conductance responses during extinction to the CS+ compared to the CS-, and to both CSs from the first to the second block of extinction trials, in comparison with low risk controls. Compared to low risk controls, children of depressed mothers showed smaller skin conductance responses to the CS+ than the CS- during acquisition. These findings suggest distinct psychophysiological premorbid risk markers in offspring of anxious and depressed mothers. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
Using Crowdsourcing to Examine Relations Between Delay and Probability Discounting

PubMed Central

Jarmolowicz, David P.; Bickel, Warren K.; Carter, Anne E.; Franck, Christopher T.; Mueller, E. Terry

2016-01-01

Although the extensive lines of research on delay and/or probability discounting have greatly expanded our understanding of human decision-making processes, the relation between these two phenomena remains unclear. For example, some studies have reported robust associations between delay and probability discounting, whereas others have failed to demonstrate a consistent relation between the two. The current study sought to clarify this relation by examining the relation between delay and probability discounting in a large sample of internet users (n= 904) using the Amazon Mechanical Turk (AMT) crowdsourcing service. Because AMT is a novel data collection platform, the findings were validated through the replication of a number of previously established relations (e.g., relations between delay discounting and cigarette smoking status). A small but highly significant positive correlation between delay and probability discounting rates was obtained, and principal component analysis suggested that two (rather than one) components were preferable to account for the variance in both delay and probability discounting. Taken together, these findings suggest that delay and probability discounting may be related, but are not manifestations of a single component (e.g., impulsivity). PMID:22982370
Comparison of Suicide Attempters and Decedents in the U.S. Army: A Latent Class Analysis.

PubMed

Skopp, Nancy A; Smolenski, Derek J; Sheppard, Sean C; Bush, Nigel E; Luxton, David D

2016-08-01

A clearer understanding of risk factors for suicidal behavior among soldiers is of principal importance to military suicide prevention. It is unclear whether soldiers who attempt suicide and those who die by suicide have different patterns of risk factors. As such, preventive efforts aimed toward reducing suicide attempts and suicides, respectively, may require different strategies. We conducted a latent class analysis (LCA) to examine classes of risk factors among suicide attempters (n = 1,433) and decedents (n = 424). Both groups were represented by three classes: (1) External/Antisocial Risk Factors, (2) Mental Health Risk Factors, and (3) No Pattern. These findings support the conceptualization that military suicide attempters and decedents represent a single population. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.
Cortical GluN2B deletion attenuates punished suppression of food reward-seeking.

PubMed

Radke, Anna K; Nakazawa, Kazu; Holmes, Andrew

2015-10-01

Compulsive behavior, which is a hallmark of psychiatric disorders such as addiction and obsessive-compulsive disorder, engages corticostriatal circuits. Previous studies indicate a role for corticostriatal N-methyl-D-aspartate receptors (NMDARs) in mediating compulsive-like responding for drugs of abuse, but the specific receptor subunits controlling reward-seeking in the face of punishment remain unclear. The current study assessed the involvement of corticostriatal GluN2B-containing NMDARs in measures of persistent and punished food reward-seeking. Mice with genetic deletion of GluN2B in one of three distinct neuronal populations, cortical principal neurons, forebrain interneurons, or striatal medium spiny neurons, were tested for (1) sustained food reward-seeking when reward was absent, (2) reward-seeking under a progressive ratio schedule of reinforcement, and (3) persistent reward-seeking after a footshock punishment. Mutant mice with genetic deletion of GluN2B in cortical principal neurons demonstrated attenuated suppression of reward-seeking during punishment. These mice performed normally on other behavioral measures, including an assay for pain sensitivity. Mutants with interneuronal or striatal GluN2B deletions were normal on all behavioral assays. Current findings offer novel evidence that loss of GluN2B-containing NMDARs expressed on principal neurons in the cortex results in reduced punished food reward-seeking. These data support the involvement of GluN2B subunit in cortical circuits regulating cognitive flexibility in a variety of settings, with implications for understanding the basis of inflexible behavior in neuropsychiatric disorders including obsessive-compulsive disorders (OCD) and addictions.
Staffing the Classroom: How Urban Principals Find Teachers and Make Hiring Decisions

ERIC Educational Resources Information Center

Engel, Mimi; Finch, Maida A.

2015-01-01

Despite the importance of teachers and the fact that teacher hiring is decentralized in most school districts, we know relatively little about the process through which individual principals hire faculty for their schools. Using interviews with 31 Chicago principals, we explore how principals find job candidates, whether they collaborate with…
The Principal's Role in Organizational Goal-Attainment: Discretionary Management at the School Site Level.

ERIC Educational Resources Information Center

Crowson, Robert L.; Morris, Van Cleve

Drawing on previous research by themselves and others, the authors argue, first, that despite findings that principals spend little time in instructional leadership activities, principals are more deeply engaged in organizational goal attainment than has been believed; and, second, that despite findings that communications between principals and…
Free Speech in a MySpace World

ERIC Educational Resources Information Center

Baule, Steven M.; Kriha, Darcy L.

2008-01-01

In the potential shadow of a "Bong Hits for Jesus" banner, complicated student speech and discipline issues arise almost daily on the Internet. Whether it is a mock MySpace page set up to make fun of a teacher or a direct threat to an assistant principal, it is often unclear exactly where school ground discipline ends and student free speech…
Dana-Farber Cancer Institute | Office of Cancer Genomics

Cancer.gov

Functional Annotation of Cancer Genomes Principal Investigator: William C. Hahn, M.D., Ph.D. The comprehensive characterization of cancer genomes has and will continue to provide an increasingly complete catalog of genetic alterations in specific cancers. However, most epithelial cancers harbor hundreds of genetic alterations as a consequence of genomic instability. Therefore, the functional consequences of the majority of mutations remain unclear.
Introducing genetic testing for cardiovascular disease in primary care: a qualitative study

PubMed Central

Middlemass, Jo B; Yazdani, Momina F; Kai, Joe; Standen, Penelope J; Qureshi, Nadeem

2014-01-01

Background While primary care systematically offers conventional cardiovascular risk assessment, genetic tests for coronary heart disease (CHD) are increasingly commercially available to patients. It is unclear how individuals may respond to these new sources of risk information. Aim To explore how patients who have had a recent conventional cardiovascular risk assessment, perceive additional information from genetic testing for CHD. Design and setting Qualitative interview study in 12 practices in Nottinghamshire from both urban and rural settings. Method Interviews were conducted with 29 adults, who consented to genetic testing after having had a conventional cardiovascular risk assessment. Results Individuals’ principal motivation for genetic testing was their family history of CHD and a desire to convey the results to their children. After testing, however, there was limited recall of genetic test results and scepticism about the value of informing their children. Participants dealt with conflicting findings from the genetic test, family history, and conventional assessment by either focusing on genetic risk or environmental lifestyle factors. In some participants, genetic test results appeared to reinforce healthy behaviour but others were falsely reassured, despite having an ‘above-average’ conventional cardiovascular risk score. Conclusion Although genetic testing was acceptable, participants were unclear how to interpret genetic risk results. To facilitate healthy behaviour, health professionals should explore patients’ understanding of genetic test results in light of their family history and conventional risk assessment. PMID:24771842
Landscape Changes Influence the Occurrence of the Melioidosis Bacterium Burkholderia pseudomallei in Soil in Northern Australia

PubMed Central

Kaestli, Mirjam; Mayo, Mark; Harrington, Glenda; Ward, Linda; Watt, Felicity; Hill, Jason V.; Cheng, Allen C.; Currie, Bart J.

2009-01-01

Background The soil-dwelling saprophyte bacterium Burkholderia pseudomallei is the cause of melioidosis, a severe disease of humans and animals in southeast Asia and northern Australia. Despite the detection of B. pseudomallei in various soil and water samples from endemic areas, the environmental habitat of B. pseudomallei remains unclear. Methodology/Principal Findings We performed a large survey in the Darwin area in tropical Australia and screened 809 soil samples for the presence of these bacteria. B. pseudomallei were detected by using a recently developed and validated protocol involving soil DNA extraction and real-time PCR targeting the B. pseudomallei–specific Type III Secretion System TTS1 gene cluster. Statistical analyses such as multivariable cluster logistic regression and principal component analysis were performed to assess the association of B. pseudomallei with environmental factors. The combination of factors describing the habitat of B. pseudomallei differed between undisturbed sites and environmentally manipulated areas. At undisturbed sites, the occurrence of B. pseudomallei was found to be significantly associated with areas rich in grasses, whereas at environmentally disturbed sites, B. pseudomallei was associated with the presence of livestock animals, lower soil pH and different combinations of soil texture and colour. Conclusions/Significance This study contributes to the elucidation of environmental factors influencing the occurrence of B. pseudomallei and raises concerns that B. pseudomallei may spread due to changes in land use. PMID:19156200

Assistant Principals: Their Readiness as Instructional Leaders

ERIC Educational Resources Information Center

Searby, Linda; Browne-Ferrigno, Tricia; Wang, Chih-hsuan

2017-01-01

This article reports findings from a study investigating the capacity of assistant principals to be instructional leaders. Analyses of survey responses yielded four interesting findings: (a) years of experience as a teacher and age had no significance on assistant principals' perceived readiness as an instructional leader; (b) those completing…
Making a Difference in Challenging Urban Schools: Successful Principals

ERIC Educational Resources Information Center

Michalak, Joanna M.

2009-01-01

The article reports upon findings from four multiple-perspective case studies of successful principals in challenging urban contexts. Each principal was described as making a significant difference to the quality of school education. The findings are obtained from the Polish part of the "Leading Schools Successfully in Challenging Urban…
High-Stakes Teacher Evaluation Policy: US Principals' Perspectives and Variations in Practice

ERIC Educational Resources Information Center

Derrington, Mary Lynne; Campbell, John W.

2018-01-01

Principals' implementation of new teacher evaluation policies in a suburban and rural southeastern area of the United States was examined over a five-year period. This study reports findings on two of eleven interview questions examining changes in principals' perceptions over time regarding policy concerns and benefits. Findings indicate while…
Preservice Principals' Post-Internship Concerns about Becoming a Principal: America and Scotland in Review

ERIC Educational Resources Information Center

Hines, Mack T., III

2008-01-01

The purpose of this study was to compare American and Scottish preservice principals' post-internship concerns about becoming a principal. The survey findings for this study showed that overall American preservice principals were more concerned about becoming principals than their Scottish preservice counterparts. Based on the groups' discussion…
Using Formative Assessments to Improve Student Learning Outcomes: A Study of the Different Types of Formative Assessments Teachers Use to Drive Instruction and Their Effects on Student Learning

ERIC Educational Resources Information Center

Alzina, Amy

2016-01-01

Understanding the difference between summative and formative assessments is still unclear for many teachers and principals as well as the effects formative assessments have on student learning outcomes. This quantitative study was conducted to explicitly explore formative assessments as a means to improve student learning outcomes, while examining…
High-throughput engineering of a mammalian genome reveals building principles of methylation states at CG rich regions.

PubMed

Krebs, Arnaud R; Dessus-Babus, Sophie; Burger, Lukas; Schübeler, Dirk

2014-09-26

The majority of mammalian promoters are CpG islands; regions of high CG density that require protection from DNA methylation to be functional. Importantly, how sequence architecture mediates this unmethylated state remains unclear. To address this question in a comprehensive manner, we developed a method to interrogate methylation states of hundreds of sequence variants inserted at the same genomic site in mouse embryonic stem cells. Using this assay, we were able to quantify the contribution of various sequence motifs towards the resulting DNA methylation state. Modeling of this comprehensive dataset revealed that CG density alone is a minor determinant of their unmethylated state. Instead, these data argue for a principal role for transcription factor binding sites, a prediction confirmed by testing synthetic mutant libraries. Taken together, these findings establish the hierarchy between the two cis-encoded mechanisms that define the DNA methylation state and thus the transcriptional competence of CpG islands.
Differential 3’ processing of specific transcripts expands regulatory and protein diversity across neuronal cell types

PubMed Central

Jereb, Saša; Hwang, Hun-Way; Van Otterloo, Eric; Govek, Eve-Ellen; Fak, John J; Yuan, Yuan; Hatten, Mary E

2018-01-01

Alternative polyadenylation (APA) regulates mRNA translation, stability, and protein localization. However, it is unclear to what extent APA regulates these processes uniquely in specific cell types. Using a new technique, cTag-PAPERCLIP, we discovered significant differences in APA between the principal types of mouse cerebellar neurons, the Purkinje and granule cells, as well as between proliferating and differentiated granule cells. Transcripts that differed in APA in these comparisons were enriched in key neuronal functions and many differed in coding sequence in addition to 3’UTR length. We characterize Memo1, a transcript that shifted from expressing a short 3’UTR isoform to a longer one during granule cell differentiation. We show that Memo1 regulates granule cell precursor proliferation and that its long 3’UTR isoform is targeted by miR-124, contributing to its downregulation during development. Our findings provide insight into roles for APA in specific cell types and establish a platform for further functional studies. PMID:29578408
Distance-dependent gradient in NMDAR-driven spine calcium signals along tapering dendrites

PubMed Central

Walker, Alison S.; Grillo, Federico; Jackson, Rachel E.; Rigby, Mark; Lowe, Andrew S.; Vizcay-Barrena, Gema; Fleck, Roland A.; Burrone, Juan

2017-01-01

Neurons receive a multitude of synaptic inputs along their dendritic arbor, but how this highly heterogeneous population of synaptic compartments is spatially organized remains unclear. By measuring N-methyl-d-aspartic acid receptor (NMDAR)-driven calcium responses in single spines, we provide a spatial map of synaptic calcium signals along dendritic arbors of hippocampal neurons and relate this to measures of synapse structure. We find that quantal NMDAR calcium signals increase in amplitude as they approach a thinning dendritic tip end. Based on a compartmental model of spine calcium dynamics, we propose that this biased distribution in calcium signals is governed by a gradual, distance-dependent decline in spine size, which we visualized using serial block-face scanning electron microscopy. Our data describe a cell-autonomous feature of principal neurons, where tapering dendrites show an inverse distribution of spine size and NMDAR-driven calcium signals along dendritic trees, with important implications for synaptic plasticity rules and spine function. PMID:28209776
Type 1 Diabetes in a Resource-Poor Setting: Malnutrition Related, Malnutrition Modified, or Just Diabetes?

PubMed

Balcha, Shitaye Alemu; Phillips, David I W; Trimble, Elisabeth R

2018-06-14

Very little is known about the occurrence of type 1 diabetes (T1DM) in resource-poor countries and particularly in their rural hinterlands. Studies of the epidemiology of T1DM in Ethiopia and similar countries in sub-Saharan Africa show that the pattern of presenting disease differs substantially from that in the West. Typically, the peak age of onset of the disease is more than a decade later with a male excess and a low prevalence of indicators of islet-cell autoimmunity. It is also associated with markers of undernutrition. These findings raise the question as to whether the principal form of T1DM seen in these resource-poor communities has a different pathogenesis. Whether the disease is a direct result of malnutrition or whether malnutrition may modify the expression of islet-cell autoimmunity is unclear. However, the poor prognosis in these settings underlines the urgent need for detailed clinical and epidemiological studies.
Internal noise estimates correlate with autistic traits.

PubMed

Vilidaite, Greta; Yu, Miaomiao; Baker, Daniel H

2017-08-01

Previous neuroimaging research has reported increased internal (neural) noise in sensory systems of autistic individuals. However, it is unclear if this difference has behavioural or perceptual consequences, as previous attempts at measuring internal noise in ASD psychophysically have been indirect. Here, we use a "gold standard" psychophysical double-pass paradigm to investigate the relationship between internal noise and autistic traits in the neurotypical population (n = 43). We measured internal noise in three tasks (contrast perception, facial expression intensity perception, and number summation) to estimate a global internal noise factor using principal components analysis. This global internal noise was positively correlated with autistic traits (r s = 0.32, P = 0.035). This suggests that increased internal noise is associated with the ASD phenotype even in subclinical populations. The finding is discussed in relation to the neural and genetic basis of internal noise in ASD. Autism Res 2017, 10: 1384-1391. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Leading Learning: First-Year Principals' Reflections on Instructional Leadership

ERIC Educational Resources Information Center

O'Doherty, Ann; Ovando, Martha N.

2013-01-01

This qualitative study examined the instructional leadership perceptions of four first-year principals. Findings illuminate five themes drawn from the data: definitions of instructional leadership, challenges that first-year principals faced, how these principals addressed these challenges, how the novice principals plan to enact their…
Principal Cluster Axes: A Projection Pursuit Index for the Preservation of Cluster Structures in the Presence of Data Reduction

ERIC Educational Resources Information Center

Steinley, Douglas; Brusco, Michael J.; Henson, Robert

2012-01-01

A measure of "clusterability" serves as the basis of a new methodology designed to preserve cluster structure in a reduced dimensional space. Similar to principal component analysis, which finds the direction of maximal variance in multivariate space, principal cluster axes find the direction of maximum clusterability in multivariate space.…
The New Principal: Now You're Cooking

ERIC Educational Resources Information Center

Gomez, Frank; Van Zant, Steve

2006-01-01

In this article, the authors, two experienced principals from two separate districts and mentors for new principals, explain that being a great principal is much the same as being the host of a great dinner party. The following are a few insights and tips-for new principals that can help any host (or principal) find rewards that go far beyond the…
Principal Preferences and the Uneven Distribution of Principals across Schools

ERIC Educational Resources Information Center

Loeb, Susanna; Kalogrides, Demetra; Horng, Eileen Lai

2010-01-01

The authors use longitudinal data from one large school district to investigate the distribution of principals across schools. They find that schools serving many low-income, non-White, and low-achieving students have principals who have less experience and less education and who attended less selective colleges. This distribution of principals is…
Stress and Job Satisfaction among Secondary School Principals in Texas

ERIC Educational Resources Information Center

Romney, Angela G.

2012-01-01

The role of a secondary school principal continues to expand and increase principals' daily workload. The high stakes testing environment also places pressure on principals to ensure that students score high on standardized tests. With a heavy workload, principals find themselves faced with numerous work-related stressors that influence job…
Implementing a Cross-District Principal Mentoring Program: A Human Resources Approach to Developing Midcareer Principals' Leadership Capacities

ERIC Educational Resources Information Center

Della Sala, Matthew R.; Klar, Hans W.; Lindle, Jane Clark; Reese, Kenyae L.; Knoeppel, Robert C.; Campbell, Michael; Buskey, Frederick C.

2013-01-01

Despite the key role that principals play in leading schoolwide change, districts' efforts to support principals are often limited, particularly in rural settings. In this article, we report the preliminary findings of a cross-district mentoring program for nine midcareer rural school principals. The collaboratively developed human resource…
The Preparation and Selection of School Principals.

ERIC Educational Resources Information Center

Cornett, Lynn M.

According to recent research findings, school principals are the motivating agents in schools where effective learning takes place. Recognizing the importance of school principals, Southern Regional Education Board (SREB) conference participants viewed a role delineation for principals and a restructuring of school organization as necessary to…
Immorally obtained principal increases investors' risk preference.

PubMed

Chen, Chuqian; Chen, Jiaxin; He, Guibing

2017-01-01

Capital derived from immoral sources is increasingly circulated in today's financial markets. The moral associations of capital are important, although their impact on investment remains unknown. This research aims to explore the influence of principal source morality on investors' risk preferences. Three studies were conducted in this regard. Study 1 finds that investors are more risk-seeking when their principal is earned immorally (through lying), whereas their risk preferences do not change when they invest money earned from neutral sources after engaging in immoral behavior. Study 2 reveals that guilt fully mediates the relationship between principal source morality and investors' risk preferences. Studies 3a and 3b introduce a new immoral principal source and a new manipulation method to improve external validity. Guilt is shown to the decrease the subjective value of morally flawed principal, leading to higher risk preference. The findings show the influence of morality-related features of principal on people's investment behavior and further support mental account theory. The results also predict the potential threats of "grey principal" to market stability.
Contemporary Challenges and Changes: Principals' Leadership Practices in Malaysia

ERIC Educational Resources Information Center

Jones, Michelle; Adams, Donnie; Joo, Mabel Tan Hwee; Muniandy, Vasu; Perera, Corinne Jaqueline; Harris, Alma

2015-01-01

This article outlines the findings from a contemporary study of principals' leadership practices in Malaysia as part of the 7 System Leadership Study. Recent policy developments within Malaysia have increased principals' accountability and have underlined the importance of the role of the principals in transforming school performance and student…
Perceptions of Isolation among High School Principals

ERIC Educational Resources Information Center

Howard, Molly P.; Mallory, Barbara J.

2008-01-01

This study addressed the perceptions of isolation among high school principals in Georgia. The data collection process, in which interviews were conducted, provided insight into the lived experiences of 10 principals. One of the findings was that high school principals were relieved, in a sense, to discuss their perceptions of the…

Instructional Leadership: Four Ethnographic Studies on Junior High School Principals.

ERIC Educational Resources Information Center

Newberg, Norman A.; Glatthorn, Allan A.

This study explores the principal's role as instructional leader in four urban schools showing improvement in test scores. Data gathering procedures included ethnographic observations and interviews of principals; principals' logs of time use; interviews with teachers, school administrators, and students; and faculty surveys. The findings were…
Toward Instructional Leadership: Principals' Perceptions of Large-Scale Assessment in Schools

ERIC Educational Resources Information Center

Prytula, Michelle; Noonan, Brian; Hellsten, Laurie

2013-01-01

This paper describes a study of the perceptions that Saskatchewan school principals have regarding large-scale assessment reform and their perceptions of how assessment reform has affected their roles as principals. The findings revealed that large-scale assessments, especially provincial assessments, have affected the principal in Saskatchewan…
Principals as Change Agents: Their Role in the Curriculum Implementation Process.

ERIC Educational Resources Information Center

Binda, K. P.

Findings from a study that examined ways in which principals implement new or revised curricula are presented in this paper, which focuses on how personal constructs influence the curriculum implementation process. Data about principals' implementation styles were obtained from interviews with 10 principals and 10 female teachers, inschool…
Alteration of the Cortical Actin Cytoskeleton Deregulates Ca2+ Signaling, Monospermic Fertilization, and Sperm Entry

PubMed Central

Puppo, A.; Chun, Jong T.; Gragnaniello, Giovanni; Garante, Ezio; Santella, Luigia

2008-01-01

Background When preparing for fertilization, oocytes undergo meiotic maturation during which structural changes occur in the endoplasmic reticulum (ER) that lead to a more efficient calcium response. During meiotic maturation and subsequent fertilization, the actin cytoskeleton also undergoes dramatic restructuring. We have recently observed that rearrangements of the actin cytoskeleton induced by actin-depolymerizing agents, or by actin-binding proteins, strongly modulate intracellular calcium (Ca2+) signals during the maturation process. However, the significance of the dynamic changes in F-actin within the fertilized egg has been largely unclear. Methodology/Principal Findings We have measured changes in intracellular Ca2+ signals and F-actin structures during fertilization. We also report the unexpected observation that the conventional antagonist of the InsP3 receptor, heparin, hyperpolymerizes the cortical actin cytoskeleton in postmeiotic eggs. Using heparin and other pharmacological agents that either hypo- or hyperpolymerize the cortical actin, we demonstrate that nearly all aspects of the fertilization process are profoundly affected by the dynamic restructuring of the egg cortical actin cytoskeleton. Conclusions/Significance Our findings identify important roles for subplasmalemmal actin fibers in the process of sperm-egg interaction and in the subsequent events related to fertilization: the generation of Ca2+ signals, sperm penetration, cortical granule exocytosis, and the block to polyspermy. PMID:18974786
Evolutionary Association of Stomatal Traits with Leaf Vein Density in Paphiopedilum, Orchidaceae

PubMed Central

Sun, Mei; Zhang, Juan-Juan; Cao, Kun-Fang; Hu, Hong

2012-01-01

Background Both leaf attributes and stomatal traits are linked to water economy in land plants. However, it is unclear whether these two components are associated evolutionarily. Methodology/Principal Findings In characterizing the possible effect of phylogeny on leaf attributes and stomatal traits, we hypothesized that a correlated evolution exists between the two. Using a phylogenetic comparative method, we analyzed 14 leaf attributes and stomatal traits for 17 species in Paphiopedilum. Stomatal length (SL), stomatal area (SA), upper cuticular thickness (UCT), and total cuticular thickness (TCT) showed strong phylogenetic conservatism whereas stomatal density (SD) and stomatal index (SI) were significantly convergent. Leaf vein density was correlated with SL and SD whether or not phylogeny was considered. The lower epidermal thickness (LET) was correlated positively with SL, SA, and stomatal width but negatively with SD when phylogeny was not considered. When this phylogenetic influence was factored in, only the significant correlation between SL and LET remained. Conclusion/Significance Our results support the hypothesis for correlated evolution between stomatal traits and vein density in Paphiopedilum. However, they do not provide evidence for an evolutionary association between stomata and leaf thickness. These findings lend insight into the evolution of traits related to water economy for orchids under natural selection. PMID:22768224
An Exploration of the Perception of the Role and Career Paths of Elementary Assistant Principals by Select Elementary Principals in Illinois

ERIC Educational Resources Information Center

Vladika, Mary Jo

2010-01-01

Research indicates that the school principal is the key to school improvement and student learning. The leadership demonstrated by the principal is essential to a school's success. Currently, because there is a shortage of qualified candidates, many school districts find themselves in a quandary when faced with a principal vacancy to fill. The…
Principal Attrition and Mobility: Results from the 2012-13 Principal Follow-Up Survey. First Look. NCES 2014-064

ERIC Educational Resources Information Center

Goldring, Rebecca; Taie, Soheyla

2014-01-01

This report presents selected findings from the Public School Principal Status and Private School Principal Status Data Files of the 2012-13 Principal Follow-up Survey (PFS). The PFS is a nationally representative sample survey of public and private K-12 schools in the 50 states and District of Columbia and was initiated to inform discussions and…
Leucine Supplementation Protects from Insulin Resistance by Regulating Adiposity Levels

PubMed Central

Binder, Elke; Bermúdez-Silva, Francisco J.; André, Caroline; Elie, Melissa; Romero-Zerbo, Silvana Y.; Leste-Lasserre, Thierry; Belluomo, llaria; Duchampt, Adeline; Clark, Samantha; Aubert, Agnes; Mezzullo, Marco; Fanelli, Flaminia; Pagotto, Uberto; Layé, Sophie; Mithieux, Gilles; Cota, Daniela

2013-01-01

Background Leucine supplementation might have therapeutic potential in preventing diet-induced obesity and improving insulin sensitivity. However, the underlying mechanisms are at present unclear. Additionally, it is unclear whether leucine supplementation might be equally efficacious once obesity has developed. Methodology/Principal Findings Male C57BL/6J mice were fed chow or a high-fat diet (HFD), supplemented or not with leucine for 17 weeks. Another group of HFD-fed mice (HFD-pairfat group) was food restricted in order to reach an adiposity level comparable to that of HFD-Leu mice. Finally, a third group of mice was exposed to HFD for 12 weeks before being chronically supplemented with leucine. Leucine supplementation in HFD-fed mice decreased body weight and fat mass by increasing energy expenditure, fatty acid oxidation and locomotor activity in vivo. The decreased adiposity in HFD-Leu mice was associated with increased expression of uncoupling protein 3 (UCP-3) in the brown adipose tissue, better insulin sensitivity, increased intestinal gluconeogenesis and preservation of islets of Langerhans histomorphology and function. HFD-pairfat mice had a comparable improvement in insulin sensitivity, without changes in islets physiology or intestinal gluconeogenesis. Remarkably, both HFD-Leu and HFD-pairfat mice had decreased hepatic lipid content, which likely helped improve insulin sensitivity. In contrast, when leucine was supplemented to already obese animals, no changes in body weight, body composition or glucose metabolism were observed. Conclusions/Significance These findings suggest that leucine improves insulin sensitivity in HFD-fed mice by primarily decreasing adiposity, rather than directly acting on peripheral target organs. However, beneficial effects of leucine on intestinal gluconeogenesis and islets of Langerhans's physiology might help prevent type 2 diabetes development. Differently, metabolic benefit of leucine supplementation is lacking in already obese animals, a phenomenon possibly related to the extent of the obesity before starting the supplementation. PMID:24086364
Post-Event Processing across Multiple Anxiety Presentations: Is it Specific to Social Anxiety Disorder?

PubMed

Perera, Stefan; Rowa, Karen; McCabe, Randi E

2016-09-01

Post-event processing (PEP) occurs when individuals engage in cognitive rumination following an event or interaction. Although the relation between PEP and social anxiety has been clearly demonstrated, it remains unclear whether PEP is limited to individuals with elevated social anxiety, or if it is also problematic among people with other anxiety presentations. The present study assessed PEP after the first session of group cognitive behavioural therapy (CBT) in individuals with a variety of anxiety presentations. Participants with a principal diagnosis of SAD (N = 25), those diagnosed with a principal other anxiety disorder with comorbid SAD (N = 18), and those with principal other anxiety diagnoses with no SAD (N = 43) completed baseline measures of social anxiety severity and state anxiety at their first session of CBT and measures of PEP one week later. Participants with a principal diagnosis of SAD experienced the most PEP in the week following the first CBT session, while those with no comorbid SAD experienced the least. Those with comorbid SAD experienced intermediate levels of PEP. The strongest predictor of PEP was state anxiety during the first session. Results suggest that PEP is more problematic for clients with SAD as part of their clinical presentation. Clinical and theoretical implications are discussed.
Beliefs and Behaviors of Two High School Principals in Developing a Sense of School Community for Students

ERIC Educational Resources Information Center

Angelle, Pamela S.

2017-01-01

This qualitative study investigated two high school principals' articulation of establishing a sense of community. The principals' narratives, values, beliefs, and behaviors are examined through the lens of community membership, fulfillment of needs, influence, and emotional connections. Findings show that the principals, leading schools with…
The Elementary School Principal's Influence on Teachers' Curricular and Instructional Decisions.

ERIC Educational Resources Information Center

Larsen, Marci L.; Malen, Betty

Within the research on teacher planning and decision making the principal is seldom mentioned as a key shaper of teachers' curricular and instructional decision making. This paper presents findings of a case study of two elementary school principals. The study examined the congruence between principals' aims and teachers' decisions; the statements…
Effective Principal, Effective School.

ERIC Educational Resources Information Center

Lipham, James M.

In summarizing findings on the principal's role in the school, this monograph assumes that the principal is a pivotal figure in the school and is the one who most affects the quality of teacher performance and student achievement. The author concludes that the studies reviewed demonstrate that the principal is a key factor in the success of the…
A Matter of Definition: Is There Truly a Shortage of School Principals?

ERIC Educational Resources Information Center

Roza, Marguerite

Although some districts and areas have experienced difficulty finding good principals, there are far more candidates certified to be principals than there are principal vacancies to fill. This report describes a study based on a written indepth survey of human-resource directors supplemented by formal survey questions to school superintendents and…
Principals' Approaches to Hiring, Assigning, Evaluating, and Developing Teachers

ERIC Educational Resources Information Center

Donaldson, Morgaen L.

2011-01-01

This article provides key findings from a study of 30 principals working in charter and conventional schools in two northeastern states. It aims to inform policy makers regarding how principals could more positively influence teacher quality. It focuses on the following questions: (1) What influenced how principals hired, assigned, evaluated, and…
School Principals' Assumptions about Human Nature: Implications for Leadership in Turkey

ERIC Educational Resources Information Center

Sabanci, Ali

2008-01-01

This article considers principals' assumptions about human nature in Turkey and the relationship between the assumptions held and the leadership style adopted in schools. The findings show that school principals hold Y-type assumptions and prefer a relationship-oriented style in their relations with assistant principals. However, both principals…
Middle School Principals' Perceptions of Middle School Counselors' Roles and Functions

ERIC Educational Resources Information Center

Zalaquett, Carlos P.; Chatters, Seriashia J.

2012-01-01

The findings of this study expand current knowledge regarding principals' perceptions of school counselors. School principals play a key role in school counselors hiring or dismissal, and their perceptions of school counselors' roles and functions may influence their decisions. Reflecting on their views may also assist school principals in…
Urban School Principals and Their Role as Multicultural Leaders

ERIC Educational Resources Information Center

Gardiner, Mary E.; Enomoto, Ernestine K.

2006-01-01

This study focuses on the role of urban school principals as multicultural leaders. Using cross-case analysis, the authors describe what 6 practicing principals do in regard to multicultural leadership. The findings suggest that although multicultural preparation was lacking for these principals, some did engage in work that promoted diversity in…
Novice Head Teachers in Scotland: Competing Expectations

ERIC Educational Resources Information Center

Crawford, Megan

2012-01-01

This article examines how novice principals reflect on the adequacy or otherwise of their preparation. It looks at data drawn from the International Study of Principal Preparation (ISPP), and in particular a questionnaire of principals up to three years in post, in Scotland. The principals find much about their preparation has helped them gain…
Job Satisfaction of Elementary Principals in Large Urban Communities

ERIC Educational Resources Information Center

Mitchell, Cathryn M.

2010-01-01

The purpose of this study was to determine job satisfaction levels of elementary principals in "major urban" districts in Texas and to identify strategies these principals used to cope with the demands of the position. Additionally, the project sought to find structures and supports needed to attract and retain principals in the…
The Work of Chicago Public Schools' Principals. Research Report

ERIC Educational Resources Information Center

Stoelinga, Sara Ray

2008-01-01

This report examines the roles and perceptions of Chicago Public Schools' principals, drawing upon Consortium surveys and principal interviews. Consortium Senior Analyst Sara Ray Stoelinga is the lead author of this report. She was assisted by Holly Hart and David Schalliol. Key findings in the research reveal that principal turnover is a pressing…

Student Teachers' Perceptions of Two Urban School Principals

ERIC Educational Resources Information Center

Swick, Kevin J.; Ross, Colvin

1973-01-01

Findings of this study indicate the student teachers' opinions of the two urban school principals were affected by three factors: the physical plant of the school; morale of the school staff; personality of the school principal. (Authors/CB)
The Embeddedness of White Fragility within White Pre-Service Principals' Reflections on White Privilege

ERIC Educational Resources Information Center

Hines, Mack T., III

2016-01-01

This study analyzes the prevalence of white fragility within the six white, pre-service principals' online responses to readings about white privilege. Six white, pre-service principals were asked to provide commentary to class readings on the relevance of white privilege to their preparation for future positions as principals. The findings showed…
The Role of Gender and How It Relates to Conflict Management Style and School Culture

ERIC Educational Resources Information Center

Blackburn, Chris Harriet; Martin, Barbara N.; Hutchinson, Sandy

2006-01-01

This investigation focused on principals, by gender, and the impact that the principals' conflict management style had on cultural aspects in schools. Findings were: principals with a conflict management style that is high in dominating show lower school culture scores in professional development, and, conversely, principals with a conflict…
School Principals as Marketing Managers: The Expanding Role of Marketing for School Development

ERIC Educational Resources Information Center

Anast-May, Linda; Mitchell, Mark; Buckner, Barbara Chesler; Elsberry, Cindy

2012-01-01

This study examined the relative importance that school principals attach to aspects of their role as marketing managers for their schools and their relative satisfaction with their efforts to date. The study included 60 principals from two school districts. Findings suggest that principals are aware of the importance of marketing in today's…
Managerial Leadership and the Effective Principal.

ERIC Educational Resources Information Center

Yukl, Gary

To help relate management ideas and knowledge to educational administration, the author reviews the major theories and findings from the last 20 years on managerial leadership and discusses their relevance for school principals. He first summarizes findings from three approaches: the traits approach, emphasizing managerial motivation and skills;…
Systematic chemical analysis approach reveals superior antioxidant capacity via the synergistic effect of flavonoid compounds in red vegetative tissues

NASA Astrophysics Data System (ADS)

Qin, Xiaoxiao; Lu, Yanfen; Peng, Zhen; Fan, Shuangxi; Yao, Yuncong

2018-02-01

The flavonoid system comprises an abundance of compounds with multiple functions; however, their potential synergism in antioxidant function remains unclear. We established an approach using ever-red (RL) and ever-green leaves (GL) of crabapple cultivars during their development to determine interrelationships among flavonoid compounds. RL scored significantly better than GL in terms of the type, composition, and diversity of flavonoids than GL. Principal component analysis predicted flavonoids in RL to have positive interaction effects, and the total antioxidant capacity was significantly higher than the sum of antioxidant capacities of the individual compounds. This synergy was verified by the high antioxidant capacity in rat serum after feeding on red leaves. Our findings suggest that the synergistic effect is a result of the high transcription levels regulated by McMYBs in RL. In summary, individual flavonoids cooperate in a flavonoid system, thus producing a synergistic antioxidant effect, and the approach used herein can provide insights into the roles of flavonoids and other compounds in future studies.
Non-linear processing of a linear speech stream: The influence of morphological structure on the recognition of spoken Arabic words.

PubMed

Gwilliams, L; Marantz, A

2015-08-01

Although the significance of morphological structure is established in visual word processing, its role in auditory processing remains unclear. Using magnetoencephalography we probe the significance of the root morpheme for spoken Arabic words with two experimental manipulations. First we compare a model of auditory processing that calculates probable lexical outcomes based on whole-word competitors, versus a model that only considers the root as relevant to lexical identification. Second, we assess violations to the root-specific Obligatory Contour Principle (OCP), which disallows root-initial consonant gemination. Our results show root prediction to significantly correlate with neural activity in superior temporal regions, independent of predictions based on whole-word competitors. Furthermore, words that violated the OCP constraint were significantly easier to dismiss as valid words than probability-matched counterparts. The findings suggest that lexical auditory processing is dependent upon morphological structure, and that the root forms a principal unit through which spoken words are recognised. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
Systematic Chemical Analysis Approach Reveals Superior Antioxidant Capacity via the Synergistic Effect of Flavonoid Compounds in Red Vegetative Tissues

PubMed Central

Qin, Xiaoxiao; Lu, Yanfen; Peng, Zhen; Fan, Shuangxi; Yao, Yuncong

2018-01-01

The flavonoid system comprises an abundance of compounds with multiple functions; however, their potential synergism in antioxidant function remains unclear. We established an approach using ever-red (RL) and ever-green leaves (GL) of crabapple cultivars during their development to determine interrelationships among flavonoid compounds. RL scored significantly better than GL in terms of the type, composition, and diversity of flavonoids than GL. Principal component analysis predicted flavonoids in RL to have positive interaction effects, and the total antioxidant capacity was significantly higher than the sum of antioxidant capacities of the individual compounds. This synergy was verified by the high antioxidant capacity in rat serum after feeding on red leaves. Our findings suggest that the synergistic effect is a result of the high transcription levels regulated by McMYBs in RL. In summary, individual flavonoids cooperate in a flavonoid system, thus producing a synergistic antioxidant effect, and the approach used herein can provide insights into the roles of flavonoids and other compounds in future studies. PMID:29468147
Principals' Perceptions of School Public Relations

ERIC Educational Resources Information Center

Morris, Robert C.; Chan, Tak Cheung; Patterson, Judith

2009-01-01

This study was designed to investigate school principals' perceptions on school public relations in five areas: community demographics, parental involvement, internal and external communications, school council issues, and community resources. Findings indicated that principals' concerns were as follows: rapid population growth, change of…
Influence of dietary macronutrients on liver fat accumulation and metabolism

PubMed Central

Parry, Siôn A; Hodson, Leanne

2017-01-01

The liver is a principal metabolic organ within the human body and has a major role in regulating carbohydrate, fat, and protein metabolism. With increasing rates of obesity, the prevalence of non-alcoholic fatty liver disease (NAFLD) is growing. It remains unclear why NAFLD, which is now defined as the hepatic manifestation of the metabolic syndrome, develops but lifestyle factors such as diet (ie, total calorie and specific nutrient intakes), appear to play a key role. Here we review the available observational and intervention studies that have investigated the influence of dietary macronutrients on liver fat content. Findings from observational studies are conflicting with some reporting that relative to healthy controls, patients with NAFLD consume diets higher in total fat/saturated fatty acids, whilst others find they consume diets higher in carbohydrates/sugars. From the limited number of intervention studies that have been undertaken, a consistent finding is a hypercaloric diet, regardless of whether the excess calories have been provided either as fat, sugar, or both, increases liver fat content. In contrast, a hypocaloric diet decreases liver fat content. Findings from both hyper- and hypo-caloric feeding studies provide some suggestion that macronutrient composition may also play a role in regulating liver fat content and this is supported by data from isocaloric feeding studies; fatty acid composition and/or carbohydrate content/type appear to influence whether there is accrual of liver fat or not. The mechanisms by which specific macronutrients, when consumed as part of an isocaloric diet, cause a change in liver fat remain to be fully elucidated. PMID:28947639
Characteristics of Public Elementary and Secondary School Principals in the United States: Results from the 2015-16 National Teacher and Principal Survey. First Look. NCES 2017-070

ERIC Educational Resources Information Center

Taie, Soheyla; Goldring, Rebecca

2017-01-01

The 2015-16 National Teacher and Principal Survey (NTPS) is a nationally representative sample survey of public K-12 schools, principals, and teachers in the 50 states and the District of Columbia. This report presents selected findings from the Public School Principal Data File of NTPS. The purpose of NTPS is to collect information that can…
General practitioner non-principals benefit from flexible working.

PubMed

French, Fiona; Andrew, Jane; Awramenko, Morag; Coutts, Helen; Leighton-Beck, Linda; Mollison, Jill; Needham, Gillian; Scott, Anthony; Walker, Kim

2005-01-01

The purpose of this study is to explore non-principals' working patterns and attitudes to work. The article is based on data provided by a questionnaire survey. Findings - Gender division was apparent among the non-principals. Males were more likely to work full-time, because their spouses modified their working hours. It was impossible to identify all non-principals in Scotland or to compare responders and non-responders, due to the lack of official data. Hence, the results might not be representative. More flexible posts would enable GPs to more easily combine paid work with family commitments. It is anticipated that the new GP contract should deliver this. This was the first time a study of all non-principals in Scotland had been attempted. The findings provide a more comprehensive picture of GPs in Scotland and provide valuable information for policymakers.
Performance-Based Preparation of Principals: A Framework for Improvement. A Special Report of the NASSP Consortium for the Performance-Based Preparation of Principals.

ERIC Educational Resources Information Center

National Association of Secondary School Principals, Reston, VA.

Preparation programs for principals should have excellent academic and performance based components. In examining the nature of performance based principal preparation this report finds that school administration programs must bridge the gap between conceptual learning in the classroom and the requirements of professional practice. A number of…
Conditions Affecting the Decision to Seek or Not Seek a Position as a School Assistant Principal/Principal

ERIC Educational Resources Information Center

Beach, Gerald M.

2010-01-01

The purpose of the study was to determine the conditions affecting the decision to seek or not seek a position as a school assistant principal or principal. The principalship presents unique challenges to the individual who aspires to building level leadership, and school districts are finding it increasingly difficult to recruit highly qualified…
Perceptions of Missouri High School Principals Regarding the Effectiveness of In-School Suspension as a Disciplinary Procedure.

ERIC Educational Resources Information Center

Billings, Ward H.; Enger, John M.

This paper presents findings of a study that examined Missouri high school principals' perceptions of the effectiveness of various disciplinary procedures, with a focus on in-school suspension (ISS). A survey mailed to 200 Missouri high school principals elicited 159 responses, a 77 percent response rate. The questionnaire asked principals to…
Principal determinants of species and functional diversity of carabid beetle assemblages during succession at post-industrial sites.

PubMed

Sipos, J; Hodecek, J; Kuras, T; Dolny, A

2017-08-01

Although ecological succession is one of the principal focuses of recent restoration ecology research, it is still unclear which factors drive this process and positively influence species richness and functional diversity. In this study we sought to elucidate how species traits and functional diversity change during forest succession, and to identify important factors that determine the species in the observed assemblages. We analyzed species richness and functional diversity of ground beetle assemblages in relation to succession on post-industrial localities after habitat deterioration caused by spoil deposition. We selected ground beetles as they are known to be sensitive to landscape changes (with a large range of responses), and their taxonomy and ecology are generally well-known. Ground beetles were sampled on the spoil heaps during the last 30 years when spontaneous succession occurred. To calculate functional diversity, we used traits related to habitat and trophic niche, i.e. food specialization, wing morphology, trophic level, and bio-indication value. Ground beetle species were found to be distributed non-randomly in the assemblages in the late phase of succession. Ordination analyses revealed that the ground beetle assemblage was significantly associated with the proportion of forested area. Environmental heterogeneity generated assemblages that contained over-dispersed species traits. Our findings indicated that environmental conditions at late successional stages supported less mobile carnivorous species. Overall, we conclude that the decline in species richness and functional diversity in the middle of the studied succession gradient indicated that the assemblages of open habitats had been replaced by species typical of forest ecosystems.
Immorally obtained principal increases investors’ risk preference

PubMed Central

Chen, Jiaxin; He, Guibing

2017-01-01

Capital derived from immoral sources is increasingly circulated in today’s financial markets. The moral associations of capital are important, although their impact on investment remains unknown. This research aims to explore the influence of principal source morality on investors’ risk preferences. Three studies were conducted in this regard. Study 1 finds that investors are more risk-seeking when their principal is earned immorally (through lying), whereas their risk preferences do not change when they invest money earned from neutral sources after engaging in immoral behavior. Study 2 reveals that guilt fully mediates the relationship between principal source morality and investors’ risk preferences. Studies 3a and 3b introduce a new immoral principal source and a new manipulation method to improve external validity. Guilt is shown to the decrease the subjective value of morally flawed principal, leading to higher risk preference. The findings show the influence of morality-related features of principal on people’s investment behavior and further support mental account theory. The results also predict the potential threats of “grey principal” to market stability. PMID:28369117
Principal Leadership of Data Team Protocols within a Professional Learning Community

ERIC Educational Resources Information Center

Chambers, Charmelle

2014-01-01

The following document represents a Problem Based Learning Project (PBL) focusing on school leadership practices leading to increased student achievement. Current research findings indicate effective principals recognize the importance of building teacher capacity through promoting collaborative team work. School principals effectively leading…
New Principals' Perspectives of Their Multifaceted Roles

ERIC Educational Resources Information Center

Gentilucci, James L.; Denti, Lou; Guaglianone, Curtis L.

2013-01-01

This study utilizes Symbolic Interactionism to explore perspectives of neophyte principals. Findings explain how these perspectives are modified through complex interactions throughout the school year, and they also suggest preparation programs can help new principals most effectively by teaching "soft" skills such as active listening…
Interactive Communication: A Few Research Answers for a Technological Explosion.

ERIC Educational Resources Information Center

Chapanis, Alphonse

The techniques, procedures, and principal findings of 15 different experiments in a research program on interactive communication are summarized in this paper. Among the principal findings reported are that: problems are solved faster in communication modes that have a voice channel than in those that do not have a voice channel, modes of…

Financing and Policy Contexts for Principal Preparation and In-Service Training Programs: Mid-Course Findings from a Study of Innovative Programs. School Leadership Study: Developing Successful Principals

ERIC Educational Resources Information Center

Cohen, Carol; Fickel, Lucinda

2005-01-01

All principal preparation and professional development programs operate within a local, state, and national policy and financing context that influences their structure, shapes their priorities, and, in some cases, dictates their existence. Financing and policy directly affect how much professional development for principals takes place, what…
The Principal: Leadership for the Effective and Productive School.

ERIC Educational Resources Information Center

Bookbinder, Robert M.

This book synthesizes research findings on principal effectiveness, viewing the principal as a key factor in ensuring school effectiveness and productivity. Methodology includes an extensive literature review, participation and observation grounded in theory, and pragmatic responses to conditions and issues. Chapter 1 presents an overview of…
Free energy landscape of a biomolecule in dihedral principal component space: sampling convergence and correspondence between structures and minima.

PubMed

Maisuradze, Gia G; Leitner, David M

2007-05-15

Dihedral principal component analysis (dPCA) has recently been developed and shown to display complex features of the free energy landscape of a biomolecule that may be absent in the free energy landscape plotted in principal component space due to mixing of internal and overall rotational motion that can occur in principal component analysis (PCA) [Mu et al., Proteins: Struct Funct Bioinfo 2005;58:45-52]. Another difficulty in the implementation of PCA is sampling convergence, which we address here for both dPCA and PCA using a tetrapeptide as an example. We find that for both methods the sampling convergence can be reached over a similar time. Minima in the free energy landscape in the space of the two largest dihedral principal components often correspond to unique structures, though we also find some distinct minima to correspond to the same structure. 2007 Wiley-Liss, Inc.
Mentoring Prospective Principals: Determinants of Productive Mentor-Mentee Relationship

ERIC Educational Resources Information Center

Schechter, Chen

2014-01-01

Mentoring contributes to prospective principals' growth, easing their transition from the role of teacher to that of administrator. This article reports findings from a study aimed at examining the determinant factors affecting the mentor-mentee relationship in a uniquely designed principal preparation program in New York City. The study…
Challenging the Image of the American Principalship.

ERIC Educational Resources Information Center

Langer, Sondra; Boris-Schacter, Sheryl

2003-01-01

Reports results of three year study of more than 200 principals about the tensions between role expectations and reality. Analysis of surveys and interviews finds most principals having to deal with three pairs of tensions: Between instructional leadership and management tasks, between personal and professional demands, and between the principal's…
Dynamic Leadership Succession: Strengthening Urban Principal Succession Planning

ERIC Educational Resources Information Center

Peters-Hawkins, April L.; Reed, Latish C.; Kingsberry, Francemise

2018-01-01

The Dynamic Leadership Succession model is used to analyze a leadership succession case in an urban school district. The qualitative findings show that the district did not forecast school leadership needs well; however, the principal sought to develop and mentor teacher leaders as her assistant principals. Second, sustaining efforts within the…
Elementary School Principals' Level of Practicing Democratic Values

ERIC Educational Resources Information Center

Kincal, Remzi Y.; Isik, Halil

2005-01-01

The purpose of this study was to find out the elementary school principals' level of practicing democratic values while managing their schools, according to teachers' perceptions. The results show that Turkish elementary principals are doing well in having democratic values in general. However, some values were more well practiced or reflected…
Principals Responding to Constant Pressure: Finding a Source of Stress Management

ERIC Educational Resources Information Center

Wells, Caryn M.

2013-01-01

This conceptual article presents a review of the research concerning the stress level of principals over the past three decades, with emphasis on the occupational stress that principals encounter because of heightened accountability and expectations for student achievement. Mindfulness meditation, as a stress management intervention, provides the…
Strengthen Your Principal's Resource Library

ERIC Educational Resources Information Center

Lasky, Beth; Karge, Belinda Dunnick

2009-01-01

How many times do teachers wander into their principal's office for advice, support, guidance, or recommendations, only to find that those books on the shelf are outdated or obsolete? How many times have principals attended individualized education program (IEP) meetings and wished they understood all the new provisions of federal laws? And when…
An Investigation into Burnout among Mississippi High School Principals.

ERIC Educational Resources Information Center

Smith-Stevenson, Ruthie; Saul, Charles E.

This paper presents findings of a study that analyzed the extent of burnout among Mississippi high school principals. Specifically, it identified the level of burnout among Mississippi high school principals, the relationship between certain demographic variables and burnout, and the relationship between burnout and personality type. The level of…
Approaches to Leadership Succession: What Comes with Experience?

ERIC Educational Resources Information Center

Macmillan, Robert B.

This paper presents findings of a study that examined the ways in which principals' succession practices change as they gain greater experience with entry into different school settings. "Succession" refers to principal transfers to new schools. Data were collected from interviews conducted with five secondary school principals and some of their…
The Job Realities of Beginning and Experienced Assistant Principals

ERIC Educational Resources Information Center

Barnett, Bruce G.; Shoho, Alan R.; Oleszewski, Ashley M.

2012-01-01

This study examined the perceptions of a cross section of new and experienced assistant principals regarding the realities of their jobs. Findings indicated that their challenges pertain to workload and task management, conflicts with adults and students, and curriculum and instruction issues. Novice and experienced assistant principals' responses…
Examining the Relationship between Collective Teacher Efficacy and the Emotional Intelligence of Elementary School Principals

ERIC Educational Resources Information Center

Pierce, Stephanie

2014-01-01

Education research has established a significant relationship between collective teacher efficacy and student achievement. This study considered the relationship between emotional intelligence of elementary school principals and collective teacher efficacy as perceived by teachers' and principals' self-report. Study findings suggest that…
From Professional Preparation to On-the-Job Development: What Do Beginning Principals Need?

ERIC Educational Resources Information Center

Duncan, Heather; Range, Bret; Scherz, Susan

2011-01-01

Wyoming principals were surveyed regarding their perceptions of the strengths and deficits of their preparation program, their professional development needs as beginning principals, and the areas in which their districts offer professional development. Findings indicated much variation in perceptions of preparation program strengths and deficits.…
School Advisory Council Demography: Birds of a Feather

ERIC Educational Resources Information Center

Greenlee, Bobbie J.

2010-01-01

This study examines the demographics of SACs and the schools they serve, and proposes that demographic similarity with the school principal influences the SAC membership. The findings draw attention to the likelihood that appointment to SAC chair may be contingent on an individual's demographic similarity with the school principal. Principals also…
The Retention and Attrition of Catholic School Principals

ERIC Educational Resources Information Center

Durow, W. Patrick; Brock, Barbara L.

2004-01-01

This article reports the results of a study of the retention of principals in Catholic elementary and secondary schools in one Midwestern diocese. Findings revealed that personal needs, career advancement, support from employer, and clearly defined role expectations were key factors in principals' retention decisions. A profile of components of…
Intrinsic and synaptic properties of vertical cells of the mouse dorsal cochlear nucleus

PubMed Central

Kuo, Sidney P.; Lu, Hsin-Wei

2012-01-01

Multiple classes of inhibitory interneurons shape the activity of principal neurons of the dorsal cochlear nucleus (DCN), a primary target of auditory nerve fibers in the mammalian brain stem. Feedforward inhibition mediated by glycinergic vertical cells (also termed tuberculoventral or corn cells) is thought to contribute importantly to the sound-evoked response properties of principal neurons, but the cellular and synaptic properties that determine how vertical cells function are unclear. We used transgenic mice in which glycinergic neurons express green fluorescent protein (GFP) to target vertical cells for whole cell patch-clamp recordings in acute slices of DCN. We found that vertical cells express diverse intrinsic spiking properties and could fire action potentials at high, sustained spiking rates. Using paired recordings, we directly examined synapses made by vertical cells onto fusiform cells, a primary DCN principal cell type. Vertical cell synapses produced unexpectedly small-amplitude unitary currents in fusiform cells, and additional experiments indicated that multiple vertical cells must be simultaneously active to inhibit fusiform cell spike output. Paired recordings also revealed that a major source of inhibition to vertical cells comes from other vertical cells. PMID:22572947
Principal short-term findings of the National Fire and Fire Surrogate study

Treesearch

James McIver; Karen Erickson; Andrew Youngblood

2012-01-01

Principal findings of the National Fire and Fire Surrogate (FFS) study are presented in an annotated bibliography and summarized in tabular form by site, discipline (ecosystem component), treatment type, and major theme. Composed of 12 sites, the FFS is a comprehensive multidisciplinary experiment designed to evaluate the costs and ecological consequences of...
Staff Development: Finding the Right Fit

ERIC Educational Resources Information Center

Standerfer, Leslie

2005-01-01

Three years ago, when the author joined the staff of Agua Fria High School in Phoenix, Arizona, as an assistant principal, she was excited to find that the students' school day started an hour and a half later than normal each Wednesday to provide staff development time for the teaching staff. That first year, however, neither the principal, Bryce…
Oenology: red wine procyanidins and vascular health.

PubMed

Corder, R; Mullen, W; Khan, N Q; Marks, S C; Wood, E G; Carrier, M J; Crozier, A

2006-11-30

Regular, moderate consumption of red wine is linked to a reduced risk of coronary heart disease and to lower overall mortality, but the relative contribution of wine's alcohol and polyphenol components to these effects is unclear. Here we identify procyanidins as the principal vasoactive polyphenols in red wine and show that they are present at higher concentrations in wines from areas of southwestern France and Sardinia, where traditional production methods ensure that these compounds are efficiently extracted during vinification. These regions also happen to be associated with increased longevity in the population.

Secondary School Vice-Principals: Commitment, Challenge, Efficacy and Synchrony

ERIC Educational Resources Information Center

Yu-kwong, Paula Kwan; Walker, Allan

2010-01-01

The study sought to investigate Hong Kong secondary school vice-principals' job facets leading to overall job satisfaction, and to differentiate the satisfaction of vice-principals of different career orientations and gender groups. The findings indicated that there are four main facets of satisfaction, in rank order of influence on overall…
Understanding the Human Side of School Leadership: Principals' Impact on Teachers' Morale, Self-Efficacy, Stress, and Commitment

ERIC Educational Resources Information Center

Lambersky, John

2016-01-01

This qualitative study from Ontario, Canada, reveals that principal behaviors shape teacher emotions in important ways, influencing teacher morale, burnout, stress, commitment, and self- and collective efficacy. The findings suggest that principals can influence teacher emotions through several key behaviors: professional respect shown for teacher…
Principal-Teacher Interactions: How Affective Relationships Shape Principal and Teacher Attitudes

ERIC Educational Resources Information Center

Price, Heather E.

2012-01-01

Purpose: Research finds that the attitudes of principals and teachers create an atmosphere for learning, often referred to as school climate, that influences school effectiveness. Other research shows that atmospheres of trust, shared vision, and openness create positive school climate conditions. Little is known, however, about how these climates…
What Principals Think Motivates Teachers

ERIC Educational Resources Information Center

Diamantes, Thomas

2004-01-01

How did a graduate class of teachers and principals come to explore what was really important to teachers? They had an idea that they all shared the same values (both teachers and principals) and would agree on what rewards teachers prize. Would administrators rate the motivation rewards the same way the teachers would? To find out, five schools…
Are Teacher and Principal Candidates Prepared to Address Student Cyberbullying?

ERIC Educational Resources Information Center

Styron, Ronald A., Jr.; Bonner, Jessica L.; Styron, Jennifer L.; Bridgeforth, James; Martin, Cecelia

2016-01-01

The purpose of this study was to examine the preparation of teacher and principal candidates to address problems created in K-12 settings as a result of cyberbullying. Participants included teacher and principal preparation students. Findings indicated that respondents were familiar with the most common forms of cyberbullying and its impact on…
The Impact of Values on a Principal's Daily Activities.

ERIC Educational Resources Information Center

Moorhead, Roslyn; Nediger, William

1991-01-01

A two-year study of four effective secondary school principals suggests that a principal's actions can be represented by a value-based model (or Markov chain) in which beliefs and values lead to goals, activities, and outcomes. Findings show that no one value set brings about more effective leadership than another. (27 references) (MLH)
Teacher Evaluation Reform: Principals' Beliefs about Newly Adopted Teacher Evaluation Systems

ERIC Educational Resources Information Center

Young, Suzanne; Range, Bret G.; Hvidston, David; Mette, Ian M.

2015-01-01

Principals in one Western state were surveyed about teacher evaluation systems commonly used across the state. Findings suggest that principals' beliefs about aligning practice to performance expectations, about how much the view of professional practice is growth-oriented, and the degree to which systems use multiple measures are the variables…
Principal Leadership in an Era of Accountability: A Perspective from the Hong Kong Context

ERIC Educational Resources Information Center

Walker, Allan; Ko, James

2011-01-01

This article presents the findings of a study into the leadership practices of Hong Kong principals working within an environment of increasing accountability. The study set out to investigate the relationships between sets of principal leadership practices and the levels of "alignment," "coherence and structure" and…
Vice-Principals' Dilemma--Career Advancement or Harmonious Working Relationship

ERIC Educational Resources Information Center

Kwan, Paula

2009-01-01

Purpose: Although the importance of shared leadership to school success has been widely recognised in the literature, only scant attention has been paid to the feelings of vice-principals over undertaking more responsibilities. Maintained by the researchers in this somewhat neglected area is the assertion that vice-principals who find their jobs…
Beginning Teachers' Induction in Chile: The Perspective of Principals

ERIC Educational Resources Information Center

Flores, Catherine

2017-01-01

This case study investigated the role of school principals in the induction of beginning teachers in Copiapó, Chile. Building upon group and individual interviews, and review of extant literature, the following findings were established: (a) principals in this study expect beginning teachers to be fully formed as classroom teachers; (b) principals…
Principal Leadership in New Teacher Induction: Becoming Agents of Change

ERIC Educational Resources Information Center

Cherian, Finney; Daniel, Yvette

2008-01-01

This small-scale pilot study investigated the role of school principals in the induction of new teachers in Ontario, Canada. Building upon the theoretical framework of Bolman and Deal (2002), as well as interviews, document analysis, and review of extant literature, the following findings were established: (a) Principals expressed that the…
The Arrival of the New Principal: Reactions of Staff.

ERIC Educational Resources Information Center

Daresh, John C.

Findings of a study that identified the kinds of problems faced by new principals who had participated in innovative principal-preparation programs are presented in this paper. Data were collected through a series of interviews conducted with eight individuals who had assumed their first principalships during the 1991-92 school year. All had…
Investing in Leadership: The District's Role in Managing Principal Turnover

ERIC Educational Resources Information Center

Mascall, Blair; Leithwood, Kenneth

2010-01-01

This article presents the results of research into the impact of principal turnover on schools, and the ability of schools to mitigate the negative effects of frequent turnover by distributing leadership in the schools. The findings from this qualitative and quantitative analysis show that rapid principal turnover does indeed have a negative…
Principal Concerns: Addressing Statewide Principal Pipelines with Data and Strategy

ERIC Educational Resources Information Center

Campbell, Christine; Gross, Bethany

2012-01-01

Discussions about human capital and school improvement typically center on teachers, not administrators, and that's a mistake. Principals, who are responsible for selecting and developing the teachers they know are so important, are a critical driver of school success. So it is imperative that states do everything they can to find, deploy, and…
The Role of the Elementary Principal in the Instructional Leadership of Special Education

ERIC Educational Resources Information Center

Frost, Lea Anne; Kersten, Thomas

2011-01-01

The purpose of this study was to explore, understand, and analyze principals' perceptions of their role as the instructional leader with special education teachers. Both surveys and follow-up telephone interviews were utilized for data collection. Findings indicate that principals holding a state special education teaching certificate reported…
Invisible Barriers: The Career Progress of Women Secondary School Principals in Greece

ERIC Educational Resources Information Center

Kaparou, Maria; Bush, Tony

2007-01-01

This paper examines the career progress of female principals in Greek secondary schools and the under-representation of women in management positions. Drawing on in-depth interviews with six women principals in Athens, the paper considers the factors affecting women's participation in school management. The findings demonstrate that women are…
How Mentor Principals Interpret the Mentoring Process Using Metaphors

ERIC Educational Resources Information Center

Schechter, Chen; Firuz, Florit

2015-01-01

The study focused on how principal mentors perceived the mentoring process by means of the metaphors they used to represent it. Semi-structured in-depth interviews were conducted with 18 principal mentors. Findings were analysed qualitatively, generating themes as an inductive process, grounded in the various metaphors articulated by participants.…
Teacher-Principal Race and Teacher Satisfaction over Time, Region

ERIC Educational Resources Information Center

Viano, Samantha L.; Hunter, Seth B.

2017-01-01

Purpose: The purpose of this paper is to replicate prior findings on teacher-principal race congruence and teacher job satisfaction and extend the literature by investigating trends over time and if the relationship between race congruence and teacher job satisfaction differs by principal race and region. Design/methodology/approach: The study…
Coping with the Principalship: Health Challenges of African-American Female School Principals and the Implications for Principal Training Certification Programs at Colleges and Universities.

ERIC Educational Resources Information Center

Walker, Doris McEwen; Hudson, Johnetta

School principals face personal challenges as a result of the effect their job has on their health. This paper presents findings of a study that examined the extent to which eight health concepts, developed by the Medical Outcomes Study (MOS) team at the Health Institute, were prevalent within a population of school principals. A survey mailed to…
Characteristics of Public and Private Elementary and Secondary School Principals in the United States: Results from the 2011-12 Schools and Staffing Survey. First Look. NCES 2013-313

ERIC Educational Resources Information Center

Bitterman, Amy; Goldring, Rebecca; Gray, Lucinda

2013-01-01

This report presents selected findings from the Public School Principal and Private School Principal Data Files of the 2011-12 Schools and Staffing Survey (SASS). SASS is a nationally representative sample survey of public and private K-12 schools, principals, and teachers in the 50 states and the District of Columbia. School districts associated…

Interpersonal Relationship Skills--Key to Effective Middle School Leadership.

ERIC Educational Resources Information Center

Meyer, Calvin F.; VanHoose, John J.

1981-01-01

Reports the findings of a study comparing the perceptions of principals and teachers toward the performance of instructional leaders. Offers recommendations for improving the principal's effectiveness. (WD)
Getting from Here to There: The Roles of Policy Makers and Principals in Increasing Science Teacher Quality

NASA Astrophysics Data System (ADS)

Shen, Ji; Gerard, Libby; Bowyer, Jane

2010-04-01

In this study we investigate how federal and state policy makers, and school principals are working to improve science teacher quality. Interviews, focused discussions, and policy documents serve as the primary data source. Findings suggest that both policy makers and principals prioritize increasing incentives for teachers entering the science teaching profession, providing professional development for new teachers, and using students’ data to evaluate and improve instruction. Differences between the two leadership groups emerged in terms of the grain size and practicality of their concerns. Our findings indicate that the complexity of educational challenges to improve science teacher quality call for the co-construction of policy by multiple constituent groups including school principals, federal and state policy makers, and science education researchers.
Influence of dietary macronutrients on liver fat accumulation and metabolism.

PubMed

Parry, Siôn A; Hodson, Leanne

2017-12-01

The liver is a principal metabolic organ within the human body and has a major role in regulating carbohydrate, fat, and protein metabolism. With increasing rates of obesity, the prevalence of non-alcoholic fatty liver disease (NAFLD) is growing. It remains unclear why NAFLD, which is now defined as the hepatic manifestation of the metabolic syndrome, develops but lifestyle factors such as diet (ie, total calorie and specific nutrient intakes), appear to play a key role. Here we review the available observational and intervention studies that have investigated the influence of dietary macronutrients on liver fat content. Findings from observational studies are conflicting with some reporting that relative to healthy controls, patients with NAFLD consume diets higher in total fat/saturated fatty acids, whilst others find they consume diets higher in carbohydrates/sugars. From the limited number of intervention studies that have been undertaken, a consistent finding is a hypercaloric diet, regardless of whether the excess calories have been provided either as fat, sugar, or both, increases liver fat content. In contrast, a hypocaloric diet decreases liver fat content. Findings from both hyper- and hypo-caloric feeding studies provide some suggestion that macronutrient composition may also play a role in regulating liver fat content and this is supported by data from isocaloric feeding studies; fatty acid composition and/or carbohydrate content/type appear to influence whether there is accrual of liver fat or not. The mechanisms by which specific macronutrients, when consumed as part of an isocaloric diet, cause a change in liver fat remain to be fully elucidated. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Mobile Technologies: Tools for Organizational Learning and Management in Schools. iPrincipals: Analyzing the Use of iPads by School Administrators

ERIC Educational Resources Information Center

Winslow, Joe; Dickerson, Jeremy; Lee, Cheng-Yuan; Geer, Gregory

2012-01-01

This paper reports findings from an evaluation of a district-wide initiative deploying iPads to school administrators (principals) to improve workflow efficiencies and promote technology leadership self-efficacy. The findings indicate that iPad utilization not only facilitated administrative tasks (memos, calendars, etc.), but also improved…
Teachers' Perceptions of Principals' Attributes.

ERIC Educational Resources Information Center

Richardson, Michael D.; And Others

1996-01-01

Presents data from a survey of teachers regarding the characteristics of principals that make them leaders. Finds that teachers' perceptions differ very little from those of business managers regarding leadership attributes. (SR)
Elementary Counselor Need and Duties: Do Nevada's Principals Reflect the National Opinion?

ERIC Educational Resources Information Center

Pierce, Keith A.

In a leading Nevada school district 35 elementary principals were surveyed to determine their perception of the need for elementary school counselors and the duties they would like a counselor to perform in their schools should counselors become available. Two findings emerged prominently: (1) the principals do want elementary school counselors;…
The Role of the Principal's Leadership Style in the Implementation of ICT Policy

ERIC Educational Resources Information Center

Hadjithoma-Garstka, Christina

2011-01-01

This paper presents findings of a study in information communication technology (ICT) implementation, on the principal's leadership style in relation to other factors that influence implementation. The principal's leadership style is perceived--on the basis of the characteristics of the context where the study was conducted--as a personal quality,…
Exploring Leadership Practices of Principals of Government Elementary Colleges of Education in Pakistan

ERIC Educational Resources Information Center

Bana, Zubeda; Khaki, Jan-e-Alam

2015-01-01

This article shares the findings from a case study conducted to explore the leadership practices of Principals of the Government Elementary Colleges of Education across Pakistan. The study focused on how these Principals understood their roles and responsibilities in the context of the changing role of teacher education in Pakistan and in the…
Principals' and Teachers' Views of Spirituality in Principal Leadership in Three Primary Schools

ERIC Educational Resources Information Center

Gibson, Alaster

2014-01-01

This article discusses key findings from my doctoral research involving a qualitative case study inquiring into the lived experiences of spirituality in principal leadership and its influence on teachers and their teaching within three public primary school contexts in New Zealand. Spirituality is understood in this article as a complex and…
The Views and Opinions of School Principals and Teachers on Positive Education

ERIC Educational Resources Information Center

Bas, Asli Uz; Firat, Necla Sahin

2017-01-01

The purpose of this study is to assess the views and opinions of school principals and teachers on positive education. The sample of the study includes 8 school principals and 12 teachers who attend different public schools in Izmir, Turkey. Data is collected through semi-structured interview technique. Findings show that majority of the…
Principals' Conceptions of Their Current Power Basis Revealed through Phenomenography

ERIC Educational Resources Information Center

Özaslan, Gökhan

2018-01-01

Purpose: The purpose of this paper is to describe the variations in the ways that principals conceptualize their basis of power in schools. Design/methodology/approach: Phenomenography was used as the research method of this study. The interviewees consisted of 16 principals, eight from public schools and eight from private schools. Findings: The…
Training Preparation and the Professional Development of Principals in Henan Province, China: Formal and Informal Learning

ERIC Educational Resources Information Center

Jiang, Na; Sumintono, Bambang; Perera, Corinne J.; Harris, Alma; Jones, Michelle S.

2018-01-01

Principal preparation and training is generally viewed as an important contributor to school and system improvement. While the international evidence based on leadership and leadership development is extensive, contemporary accounts of principal preparation in a number of Asian countries are not widespread. This article outlines the findings from…
Positioning Oneself for Leadership: Feelings of Vulnerability among Aspirant School Principals

ERIC Educational Resources Information Center

Gronn, Peter; Lacey, Kathy

2004-01-01

The research context for this article is the difficulty being experienced by a number of school systems, especially in the UK, USA, Canada and Australia, in recruiting principals. In our discussion we draw on preliminary findings from ongoing research into the experiences of a cohort of aspiring primary and secondary school principals. Our data…
A Study of Principals' Openness to Change in 168 Restructuring Schools.

ERIC Educational Resources Information Center

Klecker, Beverly; Loadman, William E.

In Ohio, Venture Capital grants are available to schools to support their school-improvement efforts. This paper presents findings of a study that examined building principals' openness to change in the 307 Ohio schools with Venture Capital Grants. The 307 principals received by mail the Inventory of Change in Organizational Culture (Dunham and…
The Double Bind for Women: Exploring the Gendered Nature of Turnaround Leadership in a Principal Preparation Program

ERIC Educational Resources Information Center

Weiner, Jennie Miles; Burton, Laura J.

2016-01-01

In this study of nine participants in a turnaround principal preparation program, Jennie Miles Weiner and Laura J. Burton explore how gender role identity shaped participants' views of effective principal leadership and their place within it. The authors find that although female and male participants initially framed effective leadership…
Holding the Reins of the Professional Learning Community: Eight Themes from Research on Principals' Perceptions of Professional Learning Communities

ERIC Educational Resources Information Center

Cranston, Jerome

2009-01-01

Using a naturalistic inquiry approach and thematic analysis, this paper outlines the findings of a research study that examined 12 Manitoba principals' conceptions of professional learning communities. The study found that these principals consider the development of professional learning communities to be a normative imperative within the…
Principals' Evidence-Based Practice--Findings from German Schools

ERIC Educational Resources Information Center

Demski, Denise; Racherbäumer, Kathrin

2015-01-01

Purpose: In Germany, principals' working environments are data-rich for school improvement purposes in a rather low-stakes test-regime. An effective use of externally as well as internally generated data, also known as data wise leadership, is considered to be a key competence of successful principals. The purpose of this paper is to describe data…
Principals' Leadership Skills and School Effectiveness: The Case of South Western Nigeria

ERIC Educational Resources Information Center

Bolanle, Akinola Oluwatoyin

2013-01-01

The study sought to find out the leadership skills possessed by Principals of public secondary schools in south western Nigeria and the relationship between these leadership skills and school effectiveness in terms of student academic achievement. The descriptive survey research design was employed for the study. 154 Principals and 770 teachers,…
Gender Differences in Instructional Leadership: A Meta-Analytic Review of Studies Using the Principal Instructional Management Rating Scale

ERIC Educational Resources Information Center

Hallinger, Philip; Dongyu, Li; Wang, Wen-Chung

2016-01-01

Purpose: Instructional leadership has assumed steadily increasing importance within the general role set of principals over the past 60 years. One persisting finding within this corpus of studies concerns the consistently higher ratings obtained by female principals on instructional leadership when compared with their male counterparts. This…
From Vision to Reality: Views of Primary School Principals on Inclusive Education in New South Wales, Australia

ERIC Educational Resources Information Center

Graham, Linda J.; Spandagou, Ilektra

2011-01-01

This paper discusses the findings of a research study that used semi-structured interviews to explore the views of primary school principals on inclusive education in New South Wales, Australia. Content analysis of the transcript data indicates that principals' attitudes towards inclusive education and their success in engineering inclusive…

Principals Learning from Veteran Teachers Serving Impoverished Students: Social Justice Implications for Professors of Educational Administration

ERIC Educational Resources Information Center

Rosine, Dale

2013-01-01

This qualitative study of ten elementary veteran teachers used Hargrove's single, double, and triple-loop thinking to understand their perceptions regarding knowledge new principals need to be social justice leaders working in impoverished schools. Findings in three categories revealed the importance of principals learning to identify their…
Troops to Teachers as School Administrators: A National Study of Principal Quality

ERIC Educational Resources Information Center

Owings, William A.; Kaplan, Leslie S.; Chappell, Shanan

2011-01-01

The United States has a scarcity of capable principals ready to successfully lead schools in an era of outcome-based accountability. This is especially true in high-poverty, high-minority schools. Policy makers welcome opening the principal pipeline to untraditional leaders. Research finds that teachers who have entered education through Troops to…
Effects of experimentally induced hyperthyroidism on central hypothalamic-pituitary-adrenal axis function in rats: in vitro and in situ studies.

PubMed

Johnson, Elizabeth O; Calogero, Aldo E; Konstandi, Maria; Kamilaris, Themis C; La Vignera, Sandro; Vignera, Sandro La; Chrousos, George P

2013-06-01

Hyperthyroidism is associated with hypercorticosteronemia, although the locus that is principally responsible for the hypercorticosteronism remains unclear. The purpose of this study was to assess the effects of hyperthyroidism on the functional integrity of the hypothalamic-pituitary-adrenal (HPA) axis, to identify the locus in the HPA axis that is principally affected, and address the time-dependent effects of alterations in thyroid status. The functional integrity of each component of the HPA axis was examined in vitro and in situ in sham-thyroidectomized male Sprague-Dawley rats given placebo or in thyroidectomized rats given pharmacological dose (50 μg) of thyroxin for 7 or 60 days. Basal plasma corticosterone and corticosterone binding globulin (CBG) concentrations were significantly increased in short- and long-term hyperthyroid rats, and by 60 days. Basal plasma ACTH levels were similar to controls. Both hypothalamic CRH content and the magnitude of KCL- and arginine vasopressin (AVP)-induced CRH release from hypothalamic culture were increased in long-term hyperthyroid rats. There was a significant increase in the content of both ACTH and β-endorphin in the anterior pituitaries of both short- and long-term hyperthyroid animals. Short-term hyperthyroid rats showed a significant increase in basal POMC mRNA expression in the anterior pituitary, and chronically hyperthyroid animals showed increased stress-induced POMC mRNA expression. Adrenal cultures taken from short-term hyperthyroid rats responded to exogenous ACTH with an exaggerated corticosterone response, while those taken from 60-day hyperthyroid animals showed responses similar to controls. The findings show that hyperthyroidism is associated with hypercorticosteronemia and HPA axis dysfunction that becomes more pronounced as the duration of hyperthyroidism increases. The evidence suggests that experimentally induced hyperthyroidism is associated with central hyperactivity of the HPA axis.
Abortion Providers' Experiences with Medicaid Abortion Coverage Policies: A Qualitative Multistate Study

PubMed Central

Dennis, Amanda; Blanchard, Kelly

2013-01-01

Objective To evaluate the implementation of state Medicaid abortion policies and the impact of these policies on abortion clients and abortion providers. Data Source From 2007 to 2010, in-depth interviews were conducted with representatives of 70 abortion-providing facilities in 15 states. Study Design In-depth interviews focused on abortion providers' perceptions regarding Medicaid and their experiences working with Medicaid and securing reimbursement in cases that should receive federal funding: rape, incest, and life endangerment. Data Extraction Data were transcribed verbatim before being coded. Principal Findings In two study states, abortion providers reported that 97 percent of submitted claims for qualifying cases were funded. Success receiving reimbursement was attributed to streamlined electronic billing procedures, timely claims processing, and responsive Medicaid staff. Abortion providers in the other 13 states reported reimbursement for 36 percent of qualifying cases. Providers reported difficulties obtaining reimbursement due to unclear rejections of qualifying claims, complex billing procedures, lack of knowledgeable Medicaid staff with whom billing problems could be discussed, and low and slow reimbursement rates. Conclusions Poor state-level implementation of Medicaid coverage of abortion policies creates barriers for women seeking abortion. Efforts to ensure policies are implemented appropriately would improve women's health. PMID:22742741
The Transcriptional Response of Drosophila melanogaster to Infection with the Sigma Virus (Rhabdoviridae)

PubMed Central

Baines, John F.; Roller, Julia; Saminadin-Peter, Sarah S.; Parsch, John; Jiggins, Francis M.

2009-01-01

Background Bacterial and fungal infections induce a potent immune response in Drosophila melanogaster, but it is unclear whether viral infections induce an antiviral immune response. Using microarrays, we examined the changes in gene expression in Drosophila that occur in response to infection with the sigma virus, a negative-stranded RNA virus (Rhabdoviridae) that occurs in wild populations of D. melanogaster. Principal Findings We detected many changes in gene expression in infected flies, but found no evidence for the activation of the Toll, IMD or Jak-STAT pathways, which control immune responses against bacteria and fungi. We identified a number of functional categories of genes, including serine proteases, ribosomal proteins and chorion proteins that were overrepresented among the differentially expressed genes. We also found that the sigma virus alters the expression of many more genes in males than in females. Conclusions These data suggest that either Drosophila do not mount an immune response against the sigma virus, or that the immune response is not controlled by known immune pathways. If the latter is true, the genes that we identified as differentially expressed after infection are promising candidates for controlling the host's response to the sigma virus. PMID:19718442
The Correlation between Teachers' Perceptions about Principal's Emotional Intelligence and Organizational Climate and Job Satisfaction of Teachers of State Senior High School in Gunungsitoli Nias, Indonesia

ERIC Educational Resources Information Center

Waruwu, Binahati

2015-01-01

This study is aimed at finding out the significant correlation between: (1) teachers' perceptions about principal's emotional intelligence and job satisfaction of teachers, (2) organizational climate and job satisfaction of teachers, and (3) teachers' perceptions about principal's emotional intelligence and organizational climate and job…
Tapping the Principal Pipeline: Identifying Talent for Future School Leadership in the Absence of Formal Succession Management Programs

ERIC Educational Resources Information Center

Myung, Jeannie; Loeb, Susanna; Horng, Eileen

2011-01-01

Purpose: In light of the difficulty many districts face finding quality principal candidates, this article explores an informal recruitment mechanism of teachers to become principals, which the authors call tapping. The authors assess the extent to which current teachers are being approached by school leaders to consider leadership and whether…
Occupational Stress and Management Strategies of Secondary School Principals in Cross River State, Nigeria

ERIC Educational Resources Information Center

Anyanwu, Joy; Ezenwaji, Ifeyinwa; Okenjom, Godian; Enyi, Chinwe

2015-01-01

The study aimed at finding out sources and symptoms of occupational stress and management strategies of principals in secondary schools in Cross River State, Nigeria. Descriptive survey research design was adopted for the study with a population of 420 principals (304 males and 116 females) in secondary schools in Cross River State, Nigeria. Three…
The Direct Effects of Principal-Student Discussions on Eighth Grade Students' Gains in Reading Achievement: An Experimental Study

ERIC Educational Resources Information Center

Silva, Jack P.; White, George P.; Yoshida, Roland K.

2011-01-01

Purpose: School effectiveness and instructional leadership research over the past 30 years has largely concluded that principal effects on student achievement are small and indirect. It has been assumed that the principal effect is important but mediated through other school factors. Findings: This experimental study found that one-on-one…
From Attila the Hun to Mary Had a Little Lamb: Redefining Principal Roles in Restructured Schools.

ERIC Educational Resources Information Center

Hallinger, Philip; Hausman, Charles

American policymakers have come to view principals as linchpins in plans for educational change. Findings of a study that examined how the principal's role changes in a school that is engaged in fundamental restructuring are presented in this paper. Data for the longitudinal case study of a suburban-urban school district in the northeastern United…
A Study of the Change Process Utilized by Colorado High School Principals: The Concordance of Practice and Theory.

ERIC Educational Resources Information Center

Jacobus, Keith

A common theme in educational change literature is that principals do not truly understand the change process and therefore cannot successfully implement change. This paper presents findings of a study that examined the change processes that Colorado principals utilized when initiating and implementing change in their buildings. The study also…
Reducing the Risks of Firearm Violence in High Schools: Principals' Perceptions and Practices.

PubMed

Price, James H; Khubchandani, Jagdish; Payton, Erica; Thompson, Amy

2016-04-01

This study assessed the perceptions and practices of a national sample of secondary school principals regarding reducing firearm violence in high schools. Data were collected via three-wave postal mailings. A 59-item valid and reliable questionnaire was mailed to a national random sample of 800 secondary school principals. Of the 349 principals (46 %) that responded, 17 % reported a firearm incident at their school in the past 5 years. Principals perceived inadequate parental monitoring (70 %), inadequate mental health services (64 %), peer harassment/bullying (59 %), and easy access to firearms (50 %) as the main causes of firearm violence in schools. The three barriers to implementing firearm violence prevention practices were: lack of expertise as to which practices to implement (33 %), lack of time (30 %), and lack of research as to which practices are most effective (30 %). Less than half of schools trained school personnel regarding firearm violence issues. The findings indicate that firearm incidents at schools may be more common than previously thought. A significant portion of principals are at a loss as to what to implement because of a lack of empirical evidence on what is effective. More research is needed to find the most effective school interventions for reducing firearm violence.
Key Findings from a National Internet Survey of 400 Teachers and 95 Principals Conducted November 12-21, 2008

ERIC Educational Resources Information Center

McCleskey, Nicole

2010-01-01

This paper presents the key findings from a national Internet survey of 400 teachers and 95 principals. This survey was conducted November 12-21, 2008. The sample was based on a list provided by EMI Surveys, a custom online research sample provider with an extensive portfolio of projects. The margin of error for a sample of 495 interviews is [plus…
Advancement of Latent Trait Theory.

DTIC Science & Technology

1988-02-01

if I am the principal investigator, I find it practically impossible to include and systematize all the important findings and implications within a...methods are described in [1.21. Two important features of the principal investigator’s approach are the following. (1) It does not assume any specific...were described in the preceding chapter, the maximum likelihood estimate 0 of ability 0 , and also f of the transformed ability r play important roles
Issues of medication administration and control in Iowa schools.

PubMed

Farris, Karen B; McCarthy, Ann Marie; Kelly, Michael W; Clay, Daniel; Gross, Jami N

2003-11-01

Who is responsible for medication administration at school? To answer this question, a descriptive, self-administered survey was mailed to a random sample of 850 school principals in Iowa. The eight-page, 57-item, anonymous survey was mailed first class, and a follow-up reminder post card was mailed two weeks later. Descriptive analyses were conducted, with type of respondent (principal versus school nurse), grade level, and size of school examined to explore differences. A 46.6% response rate was obtained; 97% of respondents indicated their schools had written guidelines for medication administration. Principals (41%) and school nurses (34%) reported that they have the ultimate legal responsibility for medication administration. Policies for medication administration on field trips were available in schools of 73.6% of respondents. High schools were more likely to allow self-medication than other grade levels. "Missed dose" was the most common medication error. The main reasons contributing to medication administration errors included poor communication among school, family, and healthcare providers, and the increased number of students on medication. It remains unclear who holds ultimate responsibility for medication administration in schools. Written policies typically exist for medication administration at school, but not field trips. Communicating medication changes to schools, and ensuring medications are available at school, likely can reduce medication administration errors.
Exploring Innovation Capabilities of Hospital CIOs: An Empirical Assessment.

PubMed

Esdar, Moritz; Liebe, Jan-David; Weiß, Jan-Patrick; Hübner, Ursula

2017-01-01

Hospital CIOs play a central role in the adoption of innovative health IT. Until now, it remained unclear which particular conditions constitute their capability to innovate in terms of intrapersonal as well as organisational factors. An inventory of 20 items was developed to capture these conditions and examined by analysing data obtained from 164 German hospital CIOs. Principal component analysis resulted in three internally consistent components that constitute large portions of the CIOs innovation capability: organisational innovation culture, entrepreneurship personality and openness towards users. Results were used to build composite indicators that allow further evaluations.
Advancing the educational and career pathway for clinical trials nurses.

PubMed

Scott, Kathleen; White, Kathryn; Roydhouse, Jessica K

2013-04-01

Clinical trials nurses play a pivotal role in the conduct of clinical research, but the educational and career pathway for these nurses remains unclear. This article reports findings from a survey of nurses working in cancer clinical trials research in Australia. Most participants held postgraduate qualifications (42 of 61); however, clinical trials education was primarily attained through short professional development courses. Interest in pursuing trial-specific postgraduate education was high, but barriers were identified, including cost, time, and unclear benefit for career advancement. Job titles varied substantially, which is indicative of an unclear employment pathway. These findings suggest that initiatives to improve the educational and career pathway for clinical trials nurses are needed and should include the following: formal educational preparation, greater consistency in employment status, and clearer career progression. These strategies should be underpinned by broad professional recognition of the clinical trials nurse as a specialized nursing role. Copyright 2013, SLACK Incorporated.
On Being a Principal: The Rewards and Challenges of School Leadership. New Directions for School Leadership. The Jossey-Bass Education Series.

ERIC Educational Resources Information Center

Donaldson, Gordon A., Jr., Ed.

1997-01-01

The principalship is increasing in complexity and responsibility to the point where principals themselves find it increasingly difficult to know their function in schools. Principals were invited to write for this volume about what is rewarding to them about the work they do. This book explores what makes the position worthwhile to these school…
The Man in the Middle: How the Urban Secondary School Principal Sees His Role and Responsibilities. (l'Homme-Cible.)

ERIC Educational Resources Information Center

Goldsborough, Harriett; And Others

Many urban high school principals are finding their jobs increasingly demanding and frustrating. This report, the result of a CEA questionnaire survey, summarizes the views of 190 principals in 23 cities on how they view their role and responsibilities. The main point of frustration is felt to be the apparent erosion of their function as…
Ways through Which Principals Acquire the Leadership Competencies Required for Effective Management of Secondary Schools in Nairobi County, Kenya

ERIC Educational Resources Information Center

Githiari, Florence W.

2017-01-01

The last two decades have seen principals in Kenya come under heavy criticism over some serious cases of mismanagement that resulted in some of the worst institutional accidents, disasters/tragedies, unrests and even social and economic crimes that Kenya has witnessed. This study sought to find out ways that principals acquire the leadership…

The Principalship at a Crossroads: A Study of the Conditions and Concerns of Principals

ERIC Educational Resources Information Center

DiPaola, Michael; Tschannen-Moran, Megan

2003-01-01

This study examined the conditions and concerns of principals in Virginia to see what their experiences and perceptions are of the growing shortage in the principalship. Findings suggest that principals do not feel that they have sufficient authority and resources to get the job done and that they are working long hours to fill the gap. More than…
The Company in the Classroom: Principals' Perceptions on How Business Partners May Support the Role of High School Education

ERIC Educational Resources Information Center

Kaufman, Kristina

2015-01-01

This study aims to give voice to public high school principals in Illinois as to their perceived views on the purpose of high school education and their perceptions of partnerships with businesses. Data from 105 distinct public high schools from 50 Illinois counties were analyzed. Findings reveal that principals view the purpose of high school…
Functional principal component analysis of glomerular filtration rate curves after kidney transplant.

PubMed

Dong, Jianghu J; Wang, Liangliang; Gill, Jagbir; Cao, Jiguo

2017-01-01

This article is motivated by some longitudinal clinical data of kidney transplant recipients, where kidney function progression is recorded as the estimated glomerular filtration rates at multiple time points post kidney transplantation. We propose to use the functional principal component analysis method to explore the major source of variations of glomerular filtration rate curves. We find that the estimated functional principal component scores can be used to cluster glomerular filtration rate curves. Ordering functional principal component scores can detect abnormal glomerular filtration rate curves. Finally, functional principal component analysis can effectively estimate missing glomerular filtration rate values and predict future glomerular filtration rate values.
Multi-timescale data assimilation for atmosphere–ocean state estimates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiger, Nathan; Hakim, Gregory

2016-06-24

Paleoclimate proxy data span seasonal to millennial timescales, and Earth's climate system has both high- and low-frequency components. Yet it is currently unclear how best to incorporate multiple timescales of proxy data into a single reconstruction framework and to also capture both high- and low-frequency components of reconstructed variables. Here we present a data assimilation approach that can explicitly incorporate proxy data at arbitrary timescales. The principal advantage of using such an approach is that it allows much more proxy data to inform a climate reconstruction, though there can be additional benefits. Through a series of offline data-assimilation-based pseudoproxy experiments,more » we find that atmosphere–ocean states are most skillfully reconstructed by incorporating proxies across multiple timescales compared to using proxies at short (annual) or long (~ decadal) timescales alone. Additionally, reconstructions that incorporate long-timescale pseudoproxies improve the low-frequency components of the reconstructions relative to using only high-resolution pseudoproxies. We argue that this is because time averaging high-resolution observations improves their covariance relationship with the slowly varying components of the coupled-climate system, which the data assimilation algorithm can exploit. These results are consistent across the climate models considered, despite the model variables having very different spectral characteristics. Furthermore, our results also suggest that it may be possible to reconstruct features of the oceanic meridional overturning circulation based on atmospheric surface temperature proxies, though here we find such reconstructions lack spectral power over a broad range of frequencies.« less
Subliminally Perceived Odours Modulate Female Intrasexual Competition: An Eye Movement Study

PubMed Central

Parma, Valentina; Tirindelli, Roberto; Bisazza, Angelo; Massaccesi, Stefano; Castiello, Umberto

2012-01-01

Background Evidence suggests that subliminal odorants influence human perception and behavior. It has been hypothesized that the human sex-steroid derived compound 4,16-androstadien-3-one (androstadienone) functions as a human chemosignal. The most intensively studied steroid compound, androstadienone is known to be biologically relevant since it seems to convey information about male mate quality to women. It is unclear if the effects of androstadienone are menstrual cycle related. Methodology/Principal Findings In the first experiment, heterosexual women were exposed to androstadienone or a control compound and asked to view stimuli such as female faces, male faces and familiar objects while their eye movements were recorded. In the second experiment the same women were asked to rate the level of stimuli attractiveness following exposure to the study or control compound. The results indicated that women at high conception risk spent more time viewing the female than the male faces regardless of the compound administered. Women at a low conception risk exhibited a preference for female faces only following exposure to androstadienone. Conclusions/Significance We contend that a woman's level of fertility influences her evaluation of potential competitors (e.g., faces of other women) during times critical for reproduction. Subliminally perceived odorants, such as androstadienone, might similarly enhance intrasexual competition strategies in women during fertility phases not critical for conception. These findings offer a substantial contribution to the current debate about the effects that subliminally perceived body odors might have on behavior. PMID:22383968
Behaviours Associated with Acoustic Communication in Nile Tilapia (Oreochromis niloticus)

PubMed Central

Longrie, Nicolas; Poncin, Pascal; Denoël, Mathieu; Gennotte, Vincent; Delcourt, Johann; Parmentier, Eric

2013-01-01

Background Sound production is widespread among fishes and accompanies many social interactions. The literature reports twenty-nine cichlid species known to produce sounds during aggressive and courtship displays, but the precise range in behavioural contexts is unclear. This study aims to describe the various Oreochromis niloticus behaviours that are associated with sound production in order to delimit the role of sound during different activities, including agonistic behaviours, pit activities, and reproduction and parental care by males and females of the species. Methodology/Principal Findings Sounds mostly occur during the day. The sounds recorded during this study accompany previously known behaviours, and no particular behaviour is systematically associated with sound production. Males and females make sounds during territorial defence but not during courtship and mating. Sounds support visual behaviours but are not used alone. During agonistic interactions, a calling Oreochromis niloticus does not bite after producing sounds, and more sounds are produced in defence of territory than for dominating individuals. Females produce sounds to defend eggs but not larvae. Conclusion/Significance Sounds are produced to reinforce visual behaviours. Moreover, comparisons with O. mossambicus indicate two sister species can differ in their use of sound, their acoustic characteristics, and the function of sound production. These findings support the role of sounds in differentiating species and promoting speciation. They also make clear that the association of sounds with specific life-cycle roles cannot be generalized to the entire taxa. PMID:23620756
Urea Transporter UT-B Deletion Induces DNA Damage and Apoptosis in Mouse Bladder Urothelium

PubMed Central

Zhou, Hong; Chen, Jihui; Lei, Tianluo; Wang, Weiling; Sun, Yi; Lin, Guiting; Bankir, Lise; Yang, Baoxue

2013-01-01

Background Previous studies found that urea transporter UT-B is abundantly expressed in bladder urothelium. However, the dynamic role of UT-B in bladder urothelial cells remains unclear. The objective of this study is to evaluate the physiological roles of UT-B in bladder urothelium using UT-B knockout mouse model and T24 cell line. Methodology/Principal Findings Urea and NO measurement, mRNA expression micro-array analysis, light and transmission electron microscopy, apoptosis assays, DNA damage and repair determination, and intracellular signaling examination were performed in UT-B null bladders vs wild-type bladders and in vitro T24 epithelial cells. UT-B was highly expressed in mouse bladder urothelium. The genes, Dcaf11, MCM2-4, Uch-L1, Bnip3 and 45 S pre rRNA, related to DNA damage and apoptosis were significantly regulated in UT-B null urothelium. DNA damage and apoptosis highly occurred in UT-B null urothelium. Urea and NO levels were significantly higher in UT-B null urothelium than that in wild-type, which may affect L-arginine metabolism and the intracellular signals related to DNA damage and apoptosis. These findings were consistent with the in vitro study in T24 cells that, after urea loading, exhibited cell cycle delay and apoptosis. Conclusions/Significance UT-B may play an important role in protecting bladder urothelium by balancing intracellular urea concentration. Disruption of UT-B function induces DNA damage and apoptosis in bladder, which can result in bladder disorders. PMID:24204711
Dynamics of cholera epidemics from Benin to Mauritania

PubMed Central

Dongdem, Anthony Zunuo; Opare, David; Cottavoz, Paul; Fookes, Maria; Sadji, Adodo Yao; Dzotsi, Emmanuel; Dogbe, Michael; Jeddi, Fakhri; Bidjada, Bawimodom; Piarroux, Martine; Valentin, Ouyi Tante; Glèlè, Clément Kakaï; Rebaudet, Stanislas; Sow, Amy Gassama; Constantin de Magny, Guillaume; Koivogui, Lamine; Dunoyer, Jessica; Bellet, Francois; Garnotel, Eric; Thomson, Nicholas; Piarroux, Renaud

2018-01-01

Background The countries of West Africa are largely portrayed as cholera endemic, although the dynamics of outbreaks in this region of Africa remain largely unclear. Methodology/Principal findings To understand the dynamics of cholera in a major portion of West Africa, we analyzed cholera epidemics from 2009 to 2015 from Benin to Mauritania. We conducted a series of field visits as well as multilocus variable tandem repeat analysis and whole-genome sequencing analysis of V. cholerae isolates throughout the study region. During this period, Ghana accounted for 52% of the reported cases in the entire study region (coastal countries from Benin to Mauritania). From 2009 to 2015, we found that one major wave of cholera outbreaks spread from Accra in 2011 northwestward to Sierra Leone and Guinea in 2012. Molecular epidemiology analysis confirmed that the 2011 Ghanaian isolates were related to those that seeded the 2012 epidemics in Guinea and Sierra Leone. Interestingly, we found that many countries deemed “cholera endemic” actually suffered very few outbreaks, with multi-year lulls. Conclusions/Significance This study provides the first cohesive vision of the dynamics of cholera epidemics in a major portion of West Africa. This epidemiological overview shows that from 2009 to 2015, at least 54% of reported cases concerned populations living in the three urban areas of Accra, Freetown, and Conakry. These findings may serve as a guide to better target cholera prevention and control efforts in the identified cholera hotspots in West Africa. PMID:29630632
Emotion Modulation of Visual Attention: Categorical and Temporal Characteristics

PubMed Central

Ciesielski, Bethany G.; Armstrong, Thomas; Zald, David H.; Olatunji, Bunmi O.

2010-01-01

Background Experimental research has shown that emotional stimuli can either enhance or impair attentional performance. However, the relative effects of specific emotional stimuli and the specific time course of these differential effects are unclear. Methodology/Principal Findings In the present study, participants (n = 50) searched for a single target within a rapid serial visual presentation of images. Irrelevant fear, disgust, erotic or neutral images preceded the target by two, four, six, or eight items. At lag 2, erotic images induced the greatest deficits in subsequent target processing compared to other images, consistent with a large emotional attentional blink. Fear and disgust images also produced a larger attentional blinks at lag 2 than neutral images. Erotic, fear, and disgust images continued to induce greater deficits than neutral images at lag 4 and 6. However, target processing deficits induced by erotic, fear, and disgust images at intermediate lags (lag 4 and 6) did not consistently differ from each other. In contrast to performance at lag 2, 4, and 6, enhancement in target processing for emotional stimuli was observed in comparison to neutral stimuli at lag 8. Conclusions/Significance These findings suggest that task-irrelevant emotion information, particularly erotica, impairs intentional allocation of attention at early temporal stages, but at later temporal stages, emotional stimuli can have an enhancing effect on directed attention. These data suggest that the effects of emotional stimuli on attention can be both positive and negative depending upon temporal factors. PMID:21079773
Similarities between principal components of protein dynamics and random diffusion

NASA Astrophysics Data System (ADS)

Hess, Berk

2000-12-01

Principal component analysis, also called essential dynamics, is a powerful tool for finding global, correlated motions in atomic simulations of macromolecules. It has become an established technique for analyzing molecular dynamics simulations of proteins. The first few principal components of simulations of large proteins often resemble cosines. We derive the principal components for high-dimensional random diffusion, which are almost perfect cosines. This resemblance between protein simulations and noise implies that for many proteins the time scales of current simulations are too short to obtain convergence of collective motions.
The First 90 Days of the New Middle School Principal in a Turnaround School: In-Depth Case Study of the Transition Period (First 90 Days)

ERIC Educational Resources Information Center

Baeza, Marco A.

2010-01-01

This study analyzed skills, strategies, and theories that new middle school principals used to be successful during their transition period (the first 90 days) in turnaround schools. Based on research on transitions, three research questions guided the study: 1. Do middle school principals in a turnaround school situation find the transition…
Effective Principal Behaviors.

ERIC Educational Resources Information Center

Research for Better Schools, Inc., Philadelphia, PA.

This paper summarizes research findings related to the performance behaviors of effective school principals. It identifies eight characteristics of effective schools: (1) schoolwide measurement and recognition of academic success; (2) high emphasis on curriculum articulation; (3) support for instructional tasks; (4) high expectations and clear…
HIV- and AIDS-related (mis)perceptions and (non)responses of school principals in the Eastern Cape, South Africa.

PubMed

Wood, Lesley; Webb, Paul

2008-05-01

Despite various HIV and AIDS training programmes offered for educators by the South African Department of Education, little has been achieved at the level of management in terms of creating a wider understanding of the social and cultural complexities of the condition and its impact on the quality of teaching and learning. Specifically, there is a lack of developmental programmes to help school principals provide leadership that can ensure that teachers and children who live in a context affected by the disease will still find themselves in a school environment of quality, care and compassion. With this in mind, we conducted a qualitative research enquiry among a sample of 12 school principals in the Eastern Cape Province in order to discover their perceptions about the impacts of HIV and AIDS on their schools and to learn how they have responded to the corresponding challenges. Our intention was to use the findings primarily to inform the development of an academic programme and short courses to empower school principals and leadership in this regard, but the findings may also be relevant as a guide for research on a larger scale.
Rule-Guided Executive Control of Response Inhibition: Functional Topography of the Inferior Frontal Cortex

PubMed Central

Cai, Weidong; Leung, Hoi-Chung

2011-01-01

Background The human inferior frontal cortex (IFC) is a large heterogeneous structure with distinct cytoarchitectonic subdivisions and fiber connections. It has been found involved in a wide range of executive control processes from target detection, rule retrieval to response control. Since these processes are often being studied separately, the functional organization of executive control processes within the IFC remains unclear. Methodology/Principal Findings We conducted an fMRI study to examine the activities of the subdivisions of IFC during the presentation of a task cue (rule retrieval) and during the performance of a stop-signal task (requiring response generation and inhibition) in comparison to a not-stop task (requiring response generation but not inhibition). We utilized a mixed event-related and block design to separate brain activity in correspondence to transient control processes from rule-related and sustained control processes. We found differentiation in control processes within the IFC. Our findings reveal that the bilateral ventral-posterior IFC/anterior insula are more active on both successful and unsuccessful stop trials relative to not-stop trials, suggesting their potential role in the early stage of stopping such as triggering the stop process. Direct countermanding seems to be outside of the IFC. In contrast, the dorsal-posterior IFC/inferior frontal junction (IFJ) showed transient activity in correspondence to the infrequent presentation of the stop signal in both tasks and the left anterior IFC showed differential activity in response to the task cues. The IFC subdivisions also exhibited similar but distinct patterns of functional connectivity during response control. Conclusions/Significance Our findings suggest that executive control processes are distributed across the IFC and that the different subdivisions of IFC may support different control operations through parallel cortico-cortical and cortico-striatal circuits. PMID:21673969
Isolation of Oct4-Expressing Extraembryonic Endoderm Precursor Cell Lines

PubMed Central

Debeb, Bisrat G.; Galat, Vasiliy; Epple-Farmer, Jessica; Iannaccone, Steve; Woodward, Wendy A.; Bader, Michael; Iannaccone, Philip; Binas, Bert

2009-01-01

Background The extraembryonic endoderm (ExEn) defines the yolk sac, a set of membranes that provide essential support for mammalian embryos. Recent findings suggest that the committed ExEn precursor is present already in the embryonic Inner Cell Mass (ICM) as a group of cells that intermingles with the closely related epiblast precursor. All ICM cells contain Oct4, a key transcription factor that is first expressed at the morula stage. In vitro, the epiblast precursor is most closely represented by the well-characterized embryonic stem (ES) cell lines that maintain the expression of Oct4, but analogous ExEn precursor cell lines are not known and it is unclear if they would express Oct4. Methodology/Principal Findings Here we report the isolation and characterization of permanently proliferating Oct4-expressing rat cell lines (“XEN-P cell lines”), which closely resemble the ExEn precursor. We isolated the XEN-P cell lines from blastocysts and characterized them by plating and gene expression assays as well as by injection into embryos. Like ES cells, the XEN-P cells express Oct4 and SSEA1 at high levels and their growth is stimulated by leukemia inhibitory factor, but instead of the epiblast determinant Nanog, they express the ExEn determinants Gata6 and Gata4. Further, they lack markers characteristic of the more differentiated primitive/visceral and parietal ExEn stages, but exclusively differentiate into these stages in vitro and contribute to them in vivo. Conclusions/Significance Our findings (i) suggest strongly that the ExEn precursor is a self-renewable entity, (ii) indicate that active Oct4 gene expression (transcription plus translation) is part of its molecular identity, and (iii) provide an in vitro model of early ExEn differentiation. PMID:19784378
Principal curve detection in complicated graph images

NASA Astrophysics Data System (ADS)

Liu, Yuncai; Huang, Thomas S.

2001-09-01

Finding principal curves in an image is an important low level processing in computer vision and pattern recognition. Principal curves are those curves in an image that represent boundaries or contours of objects of interest. In general, a principal curve should be smooth with certain length constraint and allow either smooth or sharp turning. In this paper, we present a method that can efficiently detect principal curves in complicated map images. For a given feature image, obtained from edge detection of an intensity image or thinning operation of a pictorial map image, the feature image is first converted to a graph representation. In graph image domain, the operation of principal curve detection is performed to identify useful image features. The shortest path and directional deviation schemes are used in our algorithm os principal verve detection, which is proven to be very efficient working with real graph images.
An Analysis of Instructional Facilitators' Relationships with Teachers and Principals

ERIC Educational Resources Information Center

Range, Bret G.; Pijanowski, John C.; Duncan, Heather; Scherz, Susan; Hvidston, David

2014-01-01

This study examines the perspectives of Wyoming instructional facilitators, concerning three coaching constructs--namely, their instructional leadership roles, teachers' instructional practices, and the support that they receive from principals and teachers. Findings suggest that instructional facilitators were positive about their instructional…
Advantages and Challenges of Distributing Leadership in Middle-Level Schools

ERIC Educational Resources Information Center

Grenda, J. Patrick; Hackmann, Donald G.

2014-01-01

This multiple-site case study examined distributed leadership practices of three middle school principals, using observations, interviews, and document analysis. Findings disclosed that the principals built on the interdisciplinary teaming structure to develop empowering organizational structures that promoted democratic governance. Employing…
On integrability of the Yang-Baxter {sigma}-model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klimcik, Ctirad

2009-04-15

We prove that the recently introduced Yang-Baxter {sigma}-model can be considered as an integrable deformation of the principal chiral model. We find also an explicit one-to-one map transforming every solution of the principal chiral model into a solution of the deformed model. With the help of this map, the standard procedure of the dressing of the principal chiral solutions can be directly transferred into the deformed Yang-Baxter context.
A Matter of Mindfulness.

ERIC Educational Resources Information Center

Jacobs, Richard M.

1998-01-01

Advises Catholic school principals to find a quiet place each day where distractions can be placed aside for 15 minutes to contemplate spirituality. Argues that by allowing their relationship with God to permeate their busy administration, principals' mindfulness can help foster school spirituality by providing catechetical leadership for their…

Rural Principal Leadership Skill Proficiency and Student Achievement

ERIC Educational Resources Information Center

Winn, Pam; Erwin, Sue; Gentry, Jim; Cauble, Mary

2009-01-01

Because of the importance of developing highly skilled rural school leaders, statewide assessments of 259 rural Texas public school administrators were analyzed to determine principal confidence levels in leadership skill domains identified by the National Policy Board of Educational Administration (NPBEA). Important findings indicate differences…
Urban Principal Leadership Skill Proficiency and Student Achievement

ERIC Educational Resources Information Center

Winn, Pam; Erwin, Sue; Gentry, Jim; Cauble, Mary

2009-01-01

Because of the importance of developing highly skilled urban school leaders, statewide assessments of 248 urban Texas public school administrators were analyzed to determine principal confidence levels in leadership skill domains identified by the National Policy Board of Educational Administration (NPBEA). Important findings indicate differences…
Ratio index variables or ANCOVA? Fisher's cats revisited.

PubMed

Tu, Yu-Kang; Law, Graham R; Ellison, George T H; Gilthorpe, Mark S

2010-01-01

Over 60 years ago Ronald Fisher demonstrated a number of potential pitfalls with statistical analyses using ratio variables. Nonetheless, these pitfalls are largely overlooked in contemporary clinical and epidemiological research, which routinely uses ratio variables in statistical analyses. This article aims to demonstrate how very different findings can be generated as a result of less than perfect correlations among the data used to generate ratio variables. These imperfect correlations result from measurement error and random biological variation. While the former can often be reduced by improvements in measurement, random biological variation is difficult to estimate and eliminate in observational studies. Moreover, wherever the underlying biological relationships among epidemiological variables are unclear, and hence the choice of statistical model is also unclear, the different findings generated by different analytical strategies can lead to contradictory conclusions. Caution is therefore required when interpreting analyses of ratio variables whenever the underlying biological relationships among the variables involved are unspecified or unclear. (c) 2009 John Wiley & Sons, Ltd.
Characteristics of Public Elementary and Secondary Schools in the United States: Results from the 2015-16 National Teacher and Principal Survey. First Look. NCES 2017-071

ERIC Educational Resources Information Center

Taie, Soheyla; Goldring, Rebecca

2017-01-01

The 2015-16 National Teacher and Principal Survey (NTPS) is a nationally representative sample survey of public K-12 schools, principals, and teachers in the 50 states and the District of Columbia. This report presents selected findings from the Public School Data File of NTPS. NTPS is a redesign of the Schools and Staffing Survey (SASS). SASS was…
Characteristics of Public Elementary and Secondary School Teachers in the United States: Results from the 2015-16 National Teacher and Principal Survey. First Look. NCES 2017-072

ERIC Educational Resources Information Center

Taie, Soheyla; Goldring, Rebecca

2017-01-01

The 2015-16 National Teacher and Principal Survey (NTPS) is a nationally representative sample survey of public K-12 schools, principals, and teachers in the 50 states and the District of Columbia. This report presents selected findings from the Public School Teacher Data File of NTPS. NTPS is a redesign of the Schools and Staffing Survey (SASS).…
Characteristics of Public, Private, and Bureau of Indian Education Elementary and Secondary School Principals in the United States: Results from the 2007-08 Schools and Staffing Survey. First Look. NCES 2009-323

ERIC Educational Resources Information Center

Battle, Danielle; Gruber, Kerry

2009-01-01

This report presents selected findings from the school principal data files of the 2007-08 Schools and Staffing Survey (SASS). SASS is a nationally representative sample survey of public, private, and Bureau of Indian Education-funded (BIE) K-12 schools, principals, and teachers in the 50 states and the District of Columbia. The public school…
The Rural School Principalship: Unique Challenges, Opportunities.

ERIC Educational Resources Information Center

Hill, Jonathan

1993-01-01

Presents findings based on author's research and experience as principal in California's Mojave Desert. Five basic characteristics distinguish the rural principalship: lack of an assistant principal or other support staff; assumption of other duties, including central office tasks, teaching, or management of another site; less severe student…
What Principals Should Know About Food Allergies.

ERIC Educational Resources Information Center

Munoz-Furlong, Anne

2002-01-01

Describes what principals should know about recent research findings on food allergies (peanuts, tree nuts, milk, eggs, soy, wheat) that can produce severe or life-threatening reactions in children. Asserts that every school should have trained staff and written procedures for reacting quickly to allergic reactions. (PKP)
Cost and quality implications of discrepancies between admitting and discharge diagnoses.

PubMed

McNutt, Robert; Johnson, Tricia; Kane, Jason; Ackerman, Mariel; Odwazny, Richard; Bardhan, Jaydeep

2012-01-01

Presenting and discharge diagnoses of hospitalized patients may differ as a result of patient complexity, diagnostic dilemmas, or errors in clinical judgment at the time of primary assessment. When diagnoses at admission and discharge are not in agreement, this discrepancy may indicate more complex processes of care and resultant costs. It is unclear whether surrogate measures reflecting quality of care are impacted by discrepant diagnoses. To assess whether an association exists between admitting and discharge International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes and other quality markers including hospital length of stay, total cost of care, and 30-day readmission rate. This was a retrospective, cross-sectional analysis of general internal medicine patients aged 18 years and older. Diagnosis discrepancy was defined as a difference between the 3-digit ICD-9 diagnosis code at admission and the principal 3-digit ICD-9 diagnosis code at discharge. Sixty-eight percent of patients had a diagnosis discrepancy. Diagnosis discrepancy was associated with a 0.41-day increase in length of stay (P < .001), $663 increase in direct costs (P < .001), and a 1.55 times greater odds of readmission within 30 days (P < .001). Diagnosis discrepancy was associated with hospital quality outcome measures. This finding likely reflects variations in patients' diagnostic complexity.
Mass spectrometry-based metabolic profiling of gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cells.

PubMed

Fujimura, Yoshinori; Ikenaga, Naoki; Ohuchida, Kenoki; Setoyama, Daiki; Irie, Miho; Miura, Daisuke; Wariishi, Hiroyuki; Murata, Masaharu; Mizumoto, Kazuhiro; Hashizume, Makoto; Tanaka, Masao

2014-03-01

Gemcitabine resistance (GR) is one of the critical issues for therapy for pancreatic cancer, but the mechanism still remains unclear. Our aim was to increase the understanding of GR by metabolic profiling approach. To establish GR cells, 2 human pancreatic cancer cell lines, SUIT-2 and CAPAN-1, were exposed to increasing concentration of gemcitabine. Both parental and chemoresistant cells obtained by this treatment were subjected to metabolic profiling based on liquid chromatography-mass spectrometry. Multivariate statistical analyses, both principal component analysis and orthogonal partial least squares discriminant analysis, distinguished metabolic signature of responsiveness and resistance to gemcitabine in both SUIT-2 and CAPAN-1 cells. Among significantly different (P < 0.005) metabolite peaks between parental and GR cells, we identified metabolites related to several metabolic pathways such as amino acid, nucleotide, energy, cofactor, and vitamin pathways. Decreases in glutamine and proline levels as well as increases in aspartate, hydroxyproline, creatine, and creatinine levels were observed in chemoresistant cells from both cell lines. These results suggest that metabolic profiling can isolate distinct features of pancreatic cancer in the metabolome of gemcitabine-sensitive and GR cells. These findings may contribute to the biomarker discovery and an enhanced understanding of GR in pancreatic cancer.
Possible implication of the genetic composition of the Lutzomyia longipalpis (Diptera: Psychodidae) populations in the epidemiology of the visceral leishmaniasis.

PubMed

Rocha, Leonardo de Souza; Falqueto, Aloisio; Dos Santos, Claudiney Biral; Grimaldi, Gabriel Júnior; Cupolillo, Elisa

2011-09-01

Lutzomyia longipalpis (Diptera: Psychodidae) is the principal vector of American visceral leishmaniasis. Several studies have indicated that the Lu. longipalpis population structure is complex. It has been suggested that genetic divergence caused by genetic drift, selection, or both may affect the vectorial capacity of Lu. longipalpis. However, it remains unclear whether genetic differences among Lu. longipalpis populations are directly implicated in the transmission features of visceral leishmaniasis. We evaluated the genetic composition and the patterns of genetic differentiation among Lu. longipalpis populations collected from regions with different patterns of transmission of visceral leishmaniasis by analyzing the sequence variation in the mitochondrial cytochrome b gene. Furthermore, we investigated the temporal distribution of haplotypes and compared our results with those obtained in a previous study. Our data indicate that there are differences in the haplotype composition and that there has been significant differentiation between the analyzed populations. Our results reveal that measures used to control visceral leishmaniasis might have influenced the genetic composition of the vector population. This finding raises important questions concerning the epidemiology of visceral leishmaniasis, because these differences in the genetic structures among populations of Lu. longipalpis may have implications with respect to their efficiency as vectors for visceral leishmaniasis.
On the evolutionary advantage of multi-cusped teeth

PubMed Central

Bush, Mark B.; Barani, Amir; Lawn, Brian R.

2016-01-01

A hallmark of mammalian evolution is a progressive complexity in postcanine tooth morphology. However, the driving force for this complexity remains unclear: whether to expand the versatility in diet source, or to bolster tooth structural integrity. In this study, we take a quantitative approach to this question by examining the roles of number, position and height of multiple cusps in determining sustainable bite forces. Our approach is to use an extended finite-element methodology with due provision for step-by-step growth of an embedded crack to determine how fracture progresses with increasing occlusal load. We argue that multi-cusp postcanine teeth are well configured to withstand high bite forces provided that multiple cusps are contacted simultaneously to share the load. However, contact on a single near-wall cusp diminishes the strength. Location of the load points and cusp height, rather than cusp number or radius, are principal governing factors. Given these findings, we conclude that while complex tooth structures can enhance durability, increases in cusp number are more likely to be driven by the demands of food manipulation. Structural integrity of complex teeth is maintained when individual cusps remain sufficiently distant from the side walls and do not become excessively tall relative to tooth width. PMID:27558851
Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

PubMed Central

Voigt, Christian C.; Capps, Krista A.; Dechmann, Dina K. N.; Michener, Robert H.; Kunz, Thomas H.

2008-01-01

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans. PMID:18431492
Events of hospitalization among children with sickle cell disease.

PubMed

Fosdal, Marian B; Wojner-Alexandrov, Anne W

2007-08-01

Previous research has identified vaso-occlusive pain crisis as the most common reason for hospitalization among pediatric patients with sickle cell disease. We sought to identify contributors to hospitalization and length of stay (LOS) for this patient population. A descriptive design was used to determine factors associated with hospitalization and LOS for patients with sickle cell disease at an urban tertiary care pediatric hospital in the Midwest. Sickle cell disease as a principal or secondary diagnosis during calendar year 2003 was used to identify patients for study inclusion. Data were collected from subjects' medical records and the hospital accounting system. 72 African American subjects, ranging in age from infant to 24 years (mean = 10.3) met study inclusion criteria, and accounted for 186 hospitalizations. Sickle cell pain crisis was the most common diagnosis associated with hospitalization (n = 122). Adolescent age was significantly associated with longer LOS (r = .451; p<.001), and females stayed on average 2.1 days longer than male subjects (p = .001). Age and gender appear to be associated with LOS in pediatric patients with sickle cell disease, although specific factors underlying these findings remain unclear. Further research is necessary to determine how the complex interplay of social, cultural, developmental, and physiologic factors may contribute to the hospitalization experience of children and adolescents with sickle cell disease.
Hidradenocarcinoma showing prominent mucinous and squamous differentiation and associated pagetoid cells.

PubMed

Honda, Yumi; Tanigawa, Hiroki; Harada, Miho; Fukushima, Satoshi; Masuguchi, Shinichi; Ishihara, Tsuyoshi; Ihn, Hironobu; Iyama, Ken-ichi

2013-05-01

Herein, we report a 63-year-old man presenting with hidradenocarcinoma showing prominent mucinous and squamous differentiation on his back. The tumor was dermal-based, solid and cystic. Tumor cells with squamous differentiation and with keratin pearl formation were identified predominantly in the superficial dermis, and mucinous cells were identified principally in the cystic lesion in the deep dermis. Interestingly, the additional feature of pagetoid cells was identified in the overlying epidermis. Both the mucinous cells in hidradenocarcinoma and pagetoid cells had intracytoplasmic mucin; however, they had different histopathologic findings and immunophenotypes. Mucinous cells in hidradenocarcinoma had small nuclei and abundant intracytoplasmic mucin presenting goblet cells with low rate of positive immunostaining for p53 and Ki67. In contrast, pagetoid cells had larger nuclei with less intracytoplasmic mucin. Both p53- and Ki67-positive cells were increased in pagetoid cells. Additionally, mucinous cells in hidradenocarcinoma were MUC1(+)/MUC2(-)/MUC5AC(+)/MUC6(+), but pagetoid cells were MUC1(+; focal)/MUC2(-)/MUC5AC(-)/MUC6(+; focal). The derivation of pagetoid cells is unclear; however, the localized small region of pagetoid cells over the hidradenocarcinoma in the present case may suggest a common histogenesis of these two malignant neoplasms. Copyright © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.
Tropical Mosquito Assemblages Demonstrate ‘Textbook’ Annual Cycles

PubMed Central

Franklin, Donald C.; Whelan, Peter I.

2009-01-01

Background Annual biological rhythms are often depicted as predictably cyclic, but quantitative evaluations are few and rarely both cyclic and constant among years. In the monsoon tropics, the intense seasonality of rainfall frequently drives fluctuations in the populations of short-lived aquatic organisms. However, it is unclear how predictably assemblage composition will fluctuate because the intensity, onset and cessation of the wet season varies greatly among years. Methodology/Principal Findings Adult mosquitoes were sampled using EVS suction traps baited with carbon dioxide around swamplands adjacent to the city of Darwin in northern Australia. Eleven sites were sampled weekly for five years, and one site weekly for 24 years, the sample of c. 1.4 million mosquitoes yielding 63 species. Mosquito abundance, species richness and diversity fluctuated seasonally, species richness being highly predictable. Ordination of assemblage composition demonstrated striking annual cycles that varied little from year to year. The mosquito assemblage was temporally structured by a succession of species peaks in abundance. Conclusion/Significance Ordination provided strong visual representation of annual rhythms in assemblage composition and the means to evaluate variability among years. Because most mosquitoes breed in shallow freshwater which fluctuates with rainfall, we did not anticipate such repeatability; we conclude that mosquito assemblage composition appears adapted to predictable elements of the rainfall. PMID:20011531
In Situ Observation of Modulated Light Emission of Fiber Fuse Synchronized with Void Train over Hetero-Core Splice Point

PubMed Central

Todoroki, Shin-ichi

2008-01-01

Background Fiber fuse is a process of optical fiber destruction under the action of laser radiation, found 20 years ago. Once initiated, opical discharge runs along the fiber core region to the light source and leaves periodic voids whose shape looks like a bullet pointing the direction of laser beam. The relation between damage pattern and propagation mode of optical discharge is still unclear even after the first in situ observation three years ago. Methodology/Principal Findings Fiber fuse propagation over hetero-core splice point (Corning SMF-28e and HI 1060) was observed in situ. Sequential photographs obtained at intervals of 2.78 µs recorded a periodic emission at the tail of an optical discharge pumped by 1070 nm and 9 W light. The signal stopped when the discharge ran over the splice point. The corresponding damage pattern left in the fiber core region included a segment free of periodicity. Conclusions The spatial modulation pattern of the light emission agreed with the void train formed over the hetero-core splice point. Some segments included a bullet-shaped void pointing in the opposite direction to the laser beam propagation although the sequential photographs did not reveal any directional change in the optical discharge propagation. PMID:18815621
Identification of kinship and occupant status in Mongolian noble burials of the Yuan Dynasty through a multidisciplinary approach

PubMed Central

Cui, Yinqiu; Song, Li; Wei, Dong; Pang, Yuhong; Wang, Ning; Ning, Chao; Li, Chunmei; Feng, Binxiao; Tang, Wentao; Li, Hongjie; Ren, Yashan; Zhang, Chunchang; Huang, Yanyi; Hu, Yaowu; Zhou, Hui

2015-01-01

The Yuan Dynasty (AD 1271–1368) was the first dynasty in Chinese history where a minority ethnic group (Mongols) ruled. Few cemeteries containing Mongolian nobles have been found owing to their tradition of keeping burial grounds secret and their lack of historical records. Archaeological excavations at the Shuzhuanglou site in the Hebei province of China led to the discovery of 13 skeletons in six separate tombs. The style of the artefacts and burials indicate the cemetery occupants were Mongol nobles. However, the origin, relationships and status of the chief occupant (M1m) are unclear. To shed light on the identity of the principal occupant and resolve the kin relationships between individuals, a multidisciplinary approach was adopted, combining archaeological information, stable isotope data and molecular genetic data. Analysis of autosomal, mitochondrial and Y-chromosomal DNA show that some of the occupants were related. The available evidence strongly suggests that the principal occupant may have been the Mongol noble Korguz. Our study demonstrates the power of a multidisciplinary approach in elucidating information about the inhabitants of ancient historical sites. PMID:25487330
Temperament and problem solving in a population of adolescent guide dogs.

PubMed

Bray, Emily E; Sammel, Mary D; Seyfarth, Robert M; Serpell, James A; Cheney, Dorothy L

2017-09-01

It is often assumed that measures of temperament within individuals are more correlated to one another than to measures of problem solving. However, the exact relationship between temperament and problem-solving tasks remains unclear because large-scale studies have typically focused on each independently. To explore this relationship, we tested 119 prospective adolescent guide dogs on a battery of 11 temperament and problem-solving tasks. We then summarized the data using both confirmatory factor analysis and exploratory principal components analysis. Results of confirmatory analysis revealed that a priori separation of tests as measuring either temperament or problem solving led to weak results, poor model fit, some construct validity, and no predictive validity. In contrast, results of exploratory analysis were best summarized by principal components that mixed temperament and problem-solving traits. These components had both construct and predictive validity (i.e., association with success in the guide dog training program). We conclude that there is complex interplay between tasks of "temperament" and "problem solving" and that the study of both together will be more informative than approaches that consider either in isolation.
The Burden of Leadership: Exploring the Principal's Role in Teacher Collaboration

ERIC Educational Resources Information Center

Szczesiul, Stacy; Huizenga, Jessica

2014-01-01

Based on qualitative data collected over a 6-month period, this article examines how teachers' experiences of principal leadership practice influence their capacity to engage in meaningful collegial interactions during structured collaboration. Similar to previous studies, our findings confirm the limitations of leadership that relies primarily on…

Exploring Principals' Instructional Leadership Practices in Malaysia: Insights and Implications

ERIC Educational Resources Information Center

Harris, Alma; Jones, Michelle; Cheah, Kenny Soon Lee; Devadason, Edward; Adams, Donnie

2017-01-01

Purpose: The purpose of this paper is to outline the findings from a small-scale, exploratory, study of principals' instructional leadership practice in Malaysian primary schools. The dimensions and functions of instructional leadership, explicitly explored in this study, are those outlined in the Hallinger and Murphy's (1985) model.…
San Francisco Unified School District: 2013 Survey Brief

ERIC Educational Resources Information Center

Center for Education Policy Analysis at Stanford University, 2013

2013-01-01

Since the 2009-10 school-year, the Center for Education Policy Analysis (CEPA) at Stanford University administered Teacher, Assistant Principal (AP), and Principal surveys as part of San Francisco Unified School District's (SFUSD's) evaluation of the Quality Teacher and Education Act (passed as Proposition A 2008). The findings from these surveys…
How Do Principals Conceptualize Success: Are Their Actions Consistent with Their Definitions?

ERIC Educational Resources Information Center

Patience, Brian J.

2012-01-01

My research study explored how principals allocated their time, their perceptions of success, and whether their actions were consistent with their definition of success. Findings revealed participants spent time performing three primary behaviors including communicating with school stakeholders, completing managerial practices, and serving as…
Developing Instructional Leaders through Assistant Principals' Academy: A Partnership for Success

ERIC Educational Resources Information Center

Gurley, D. Keith; Anast-May, Linda; Lee, H. T.

2015-01-01

This article describes findings from a single-case qualitative study of a unique 2-year professional development academy for practicing assistant principals designed and implemented in partnership between school district personnel and university educational leadership faculty members. The study was conducted based on the theoretical framework of…
Verbal and Nonverbal Micropolitical Communication of Female School Principals.

ERIC Educational Resources Information Center

Carr, Carolyn S.

Verbal and nonverbal communication as an expression of political influence and power plays a major part in constructing and transmitting an androcentric bias in educational administration. This paper describes findings of a study that examined the form, meaning, and function of three female principals' verbal and nonverbal communication behaviors,…
Effective Middle Level Teaching: Perceptions on the Preparedness of Newly Hired Teachers

ERIC Educational Resources Information Center

Howell, Penny B.; Cook, Chris; Faulkner, Shawn A.

2013-01-01

This interpretive, exploratory study utilized survey methodology to document middle level principals' perceptions of effective teaching practices and the preparedness of newly hired middle level teachers. The findings suggest that principals' descriptions of effective teaching differ from their descriptions of effective teachers. Additionally,…
Principal Leadership in Low-Performing Schools: A Closer Look through the Eyes of Teachers

ERIC Educational Resources Information Center

Finnigan, Kara S.

2012-01-01

This qualitative study of teachers in three low-performing elementary schools in Chicago reveals that transformational leadership behaviors were important to teacher motivation, affecting whether they believed that they could improve student performance as the accountability policy required. The findings suggest that principal leadership is…
Managing Change from a Quality Perspective.

ERIC Educational Resources Information Center

Snyder, Karolyn J.

This paper presents findings of a study that examined the change process in 28 schools, with a focus on how principals went about transforming traditional school-work cultures into quality systems. The principals had participated in Managing Productive Schools (MPS), a comprehensive systems-approach program based on quality management concepts.…
Building Leadership Skills with Evaluation Techniques

ERIC Educational Resources Information Center

Hutton, Dawn

2009-01-01

The career of educational administrator does not lend itself well to allowing new principals to practice their skills. Because of the element of responsibility for administrators, most principals are reluctant to relinquish power to interns in fear of their failure. As a result, educational leadership programs struggle to find appropriate methods…
Beliefs and Behaviors of Elementary Principals of Successful Title I Schools

ERIC Educational Resources Information Center

Blount, Margie

2014-01-01

This qualitative phenomenological research study used narrative inquiry to investigate the behaviors and beliefs of eight Texas principals in high achieving Title I elementary schools. Participant interviews were analyzed using Creswell (2007) six-step method for analyzing phenomenological studies. Findings suggested that successful Title I…
Strengthening Principal Leadership Is Only One Piece of the Puzzle. Lessons from Research

ERIC Educational Resources Information Center

Killion, Joellen

2015-01-01

In this article, Joellen Killion highlights the methodology, analysis, findings, and limitations of Jacob, R., Goddard, R., Kim, M., Miller, R., & Goddard, Y. (2015, September). "Exploring the causal impact of the McREL Balanced Leadership program on leadership, principal efficacy, instructional climate, educator turnover, and student…
Excellence in Schooling: Effective Styles for Effective Schools.

ERIC Educational Resources Information Center

Georgiades, William D. H.

School principals are an important factor in the improvement of American schools. Key findings of two studies show that principals are the most significant people in the educational change process. Outlined are seven important steps involved in the process of instructional improvement that will take place only if committed and knowledgeable…
Teacher Efficacy: Influence of Principal Leadership Behavior.

ERIC Educational Resources Information Center

Hipp, Kristine A.

This paper presents findings of a study that explored the relationships among principals' leadership behaviors and teacher efficacy in Wisconsin middle schools involved in building-level change efforts. An adaptation of Bandura's social cognitive learning theory of self-efficacy (A. Woolfolk and W. Hoy 1993) provided the theoretical framework.…
Living Leadership in an Era of Change

ERIC Educational Resources Information Center

Fennell, Hope-Arlene

2005-01-01

This article discusses the findings from a recently completed two-year study of women principals' lived experiences with leadership. It focuses on the six women's lived experiences with leading change in their school. Data were collected using in-depth, phenomenological interviews, observations of the principals' work in schools, and field notes.…
Professional Norms Guiding School Principals' Pedagogical Leadership

ERIC Educational Resources Information Center

Leo, Ulf

2015-01-01

Purpose: The purpose of this paper is to identify and analyze the professional norms surrounding school development, with a special emphasis on school principals' pedagogical leadership. Design/methodology/approach: A norm perspective is used to identify possible links between legal norms, professional norms, and actions. The findings are based on…
Perspectives on Principal Instructional Leadership in Vietnam: A Preliminary Model

ERIC Educational Resources Information Center

Hallinger, Philip; Walker, Allan; Nguyen, Dao Thi Hong; Truong, Thang; Nguyen, Thi Thinh

2017-01-01

Purpose: Worldwide interest in principal instructional leadership has led to global dissemination of related research findings despite their concentration in a limited set of western cultural contexts. An urgent challenge in educational leadership and management lies in expanding the range of national settings for investigations of instructional…
Running on Empty? Finding the Time and Capacity to Lead Learning

ERIC Educational Resources Information Center

Hallinger, Philip; Murphy, Joseph F.

2013-01-01

In recent years, policy changes in American education have refocused a spotlight on principal instructional leadership. Although in previous eras the professional literature exhorted principals to "be instructional leaders," there were few sanctions if they failed to do so. In the current policy context, however, instructional leadership has…
Perturbation analyses of intermolecular interactions

NASA Astrophysics Data System (ADS)

Koyama, Yohei M.; Kobayashi, Tetsuya J.; Ueda, Hiroki R.

2011-08-01

Conformational fluctuations of a protein molecule are important to its function, and it is known that environmental molecules, such as water molecules, ions, and ligand molecules, significantly affect the function by changing the conformational fluctuations. However, it is difficult to systematically understand the role of environmental molecules because intermolecular interactions related to the conformational fluctuations are complicated. To identify important intermolecular interactions with regard to the conformational fluctuations, we develop herein (i) distance-independent and (ii) distance-dependent perturbation analyses of the intermolecular interactions. We show that these perturbation analyses can be realized by performing (i) a principal component analysis using conditional expectations of truncated and shifted intermolecular potential energy terms and (ii) a functional principal component analysis using products of intermolecular forces and conditional cumulative densities. We refer to these analyses as intermolecular perturbation analysis (IPA) and distance-dependent intermolecular perturbation analysis (DIPA), respectively. For comparison of the IPA and the DIPA, we apply them to the alanine dipeptide isomerization in explicit water. Although the first IPA principal components discriminate two states (the α state and PPII (polyproline II) + β states) for larger cutoff length, the separation between the PPII state and the β state is unclear in the second IPA principal components. On the other hand, in the large cutoff value, DIPA eigenvalues converge faster than that for IPA and the top two DIPA principal components clearly identify the three states. By using the DIPA biplot, the contributions of the dipeptide-water interactions to each state are analyzed systematically. Since the DIPA improves the state identification and the convergence rate with retaining distance information, we conclude that the DIPA is a more practical method compared with the IPA. To test the feasibility of the DIPA for larger molecules, we apply the DIPA to the ten-residue chignolin folding in explicit water. The top three principal components identify the four states (native state, two misfolded states, and unfolded state) and their corresponding eigenfunctions identify important chignolin-water interactions to each state. Thus, the DIPA provides the practical method to identify conformational states and their corresponding important intermolecular interactions with distance information.
Perturbation analyses of intermolecular interactions.

PubMed

Koyama, Yohei M; Kobayashi, Tetsuya J; Ueda, Hiroki R

2011-08-01

Conformational fluctuations of a protein molecule are important to its function, and it is known that environmental molecules, such as water molecules, ions, and ligand molecules, significantly affect the function by changing the conformational fluctuations. However, it is difficult to systematically understand the role of environmental molecules because intermolecular interactions related to the conformational fluctuations are complicated. To identify important intermolecular interactions with regard to the conformational fluctuations, we develop herein (i) distance-independent and (ii) distance-dependent perturbation analyses of the intermolecular interactions. We show that these perturbation analyses can be realized by performing (i) a principal component analysis using conditional expectations of truncated and shifted intermolecular potential energy terms and (ii) a functional principal component analysis using products of intermolecular forces and conditional cumulative densities. We refer to these analyses as intermolecular perturbation analysis (IPA) and distance-dependent intermolecular perturbation analysis (DIPA), respectively. For comparison of the IPA and the DIPA, we apply them to the alanine dipeptide isomerization in explicit water. Although the first IPA principal components discriminate two states (the α state and PPII (polyproline II) + β states) for larger cutoff length, the separation between the PPII state and the β state is unclear in the second IPA principal components. On the other hand, in the large cutoff value, DIPA eigenvalues converge faster than that for IPA and the top two DIPA principal components clearly identify the three states. By using the DIPA biplot, the contributions of the dipeptide-water interactions to each state are analyzed systematically. Since the DIPA improves the state identification and the convergence rate with retaining distance information, we conclude that the DIPA is a more practical method compared with the IPA. To test the feasibility of the DIPA for larger molecules, we apply the DIPA to the ten-residue chignolin folding in explicit water. The top three principal components identify the four states (native state, two misfolded states, and unfolded state) and their corresponding eigenfunctions identify important chignolin-water interactions to each state. Thus, the DIPA provides the practical method to identify conformational states and their corresponding important intermolecular interactions with distance information.
The response of bone to unloading

NASA Technical Reports Server (NTRS)

Bikle, D. D.; Halloran, B. P.

1999-01-01

Skeletal unloading leads to decreased bone formation and decreased bone mass. Bone resorption is uncoupled from bone formation, contributing to the bone loss. During spaceflight bone is lost principally from the bones most loaded in the 1-g environment, and some redistribution of bone from the lower extremities to the head appears to take place. Although changes in calcitropic hormones have been demonstrated during skeletal unloading (PTH and 1,25(OH)2D decrease), it remains unclear whether such changes account for or are in response to the changes in bone formation and resorption. Bed rest studies with human volunteers and hindlimb elevation studies with rats have provided useful data to help explain the changes in bone formation during spaceflight. These models of skeletal unloading reproduce a number of the conditions associated with microgravity, and the findings from such studies confirm many of the observations made during spaceflight. Determining the mechanism(s) by which loading of bone is sensed and translated into a signal(s) controlling bone formation remains the holy grail in this field. Such investigations couple biophysics to biochemistry to cell and molecular biology. Although studies with cell cultures have revealed biochemical responses to mechanical loads comparable to that seen in intact bone, it seems likely that matrix-cell interactions underlie much of the mechanocoupling. The role for systemic hormones such as PTH, GH, and 1,25(OH)2D compared to locally produced factors such as IGF-I, PTHrP, BMPs, and TGF-beta in modulating the cellular response to load remains unclear. As the mechanism(s) by which bone responds to mechanical load with increased bone formation are further elucidated, applications of this knowledge to other etiologies of osteoporosis are likely to develop. Skeletal unloading provides a perturbation in bone mineral homeostasis that can be used to understand the mechanisms by which bone mineral homeostasis is maintained, with the expectation that such understanding will lead to effective treatment for disuse osteoporosis.

The role of engineering in the flight equipment purchasing process

NASA Technical Reports Server (NTRS)

1977-01-01

The role of the airline engineering department in the flight equipment acquisition process is examined. The data for the study was collected from six airlines. The principal findings of the study include: (1) engineering activities permeate, but do not dominate the airline flight equipment decision process. (2) The principal criterion for the flight equipment acquisition decision is return on investment. (3) The principal sources of information for the airline engineering departments in the monitoring process are the manufacturers of equipment. Subsidiary information sources include NASA publications and conferences, among others and (4) The engineering department is the principal communication channel for technical information.
The impact of the principal in the implementation of promoting science among English language learners (P-SELL)

NASA Astrophysics Data System (ADS)

Kittrell, Resma

School organizations are in a constant state of change. One of the major changes that all schools encounter is adopting new curriculum. It is important to look at the role of the principal during the implementation of a new curriculum so that we can identify specific strategies that might be useful in other areas of school change. This study focuses on the role of the principal during the adoption of a new science curriculum, Promoting Science Among English Language Learners (P-SELL), within six elementary schools. This multiple case study included teacher focus group interviews, principal interviews, and teacher and principal written surveys to identify specific roles and strategies that principals illustrated during implementation of P-SELL. The overarching themes uncovered included (a) distributive leadership, (b) clear communication, and (c) supportive conditions. These findings can be used to understand the process of change within an organization.
Finding Planets in K2: A New Method of Cleaning the Data

NASA Astrophysics Data System (ADS)

Currie, Miles; Mullally, Fergal; Thompson, Susan E.

2017-01-01

We present a new method of removing systematic flux variations from K2 light curves by employing a pixel-level principal component analysis (PCA). This method decomposes the light curves into its principal components (eigenvectors), each with an associated eigenvalue, the value of which is correlated to how much influence the basis vector has on the shape of the light curve. This method assumes that the most influential basis vectors will correspond to the unwanted systematic variations in the light curve produced by K2’s constant motion. We correct the raw light curve by automatically fitting and removing the strongest principal components. The strongest principal components generally correspond to the flux variations that result from the motion of the star in the field of view. Our primary method of calculating the strongest principal components to correct for in the raw light curve estimates the noise by measuring the scatter in the light curve after using an algorithm for Savitsy-Golay detrending, which computes the combined photometric precision value (SG-CDPP value) used in classic Kepler. We calculate this value after correcting the raw light curve for each element in a list of cumulative sums of principal components so that we have as many noise estimate values as there are principal components. We then take the derivative of the list of SG-CDPP values and take the number of principal components that correlates to the point at which the derivative effectively goes to zero. This is the optimal number of principal components to exclude from the refitting of the light curve. We find that a pixel-level PCA is sufficient for cleaning unwanted systematic and natural noise from K2’s light curves. We present preliminary results and a basic comparison to other methods of reducing the noise from the flux variations.
Less Therapy Okay for Some with Wilms Tumor?

Cancer.gov

Some children with advanced Wilms tumor, a form of kidney cancer, may be able to skip radiation therapy, findings from an NCI-funded clinical trial show. It’s unclear if the finding will change clinical practice, as this Cancer Currents post reports.
Leadership and organisational effectiveness--lessons to be drawn from education?

PubMed

Joyce, Pauline

2009-05-01

The aim of this paper is to present findings of a case study on organisational effectiveness in an education setting and draw similarities with a healthcare setting, focusing on the school principal and nurse leader. The study was carried out in a primary school setting and focuses on a principal (as leader). The school, which will be named St Senan's for the case study, is a typical tall structure, has a staff of 30 (teachers and special needs' assistants) and a student number of 117. A case study methodology was used. Data was collected by interviewing the principal, two teachers, two students and a parent, in this order. In addition, a Parents' Council meeting was observed and document analysis was carried out on measurements which reflected some critical success factors for the school. Interviews from students and teachers in addition to observation notes indicate that the principal's leadership impacts on organisational effectiveness in the school. The findings are located in the context of education with similarities being drawn from nursing. It is how the leader leads in the context of the organisation setting which is paramount. In other words it is not possible to take a set of general critical success factors for a school or healthcare setting and apply these widely. The paper concludes by proposing the use of a quality framework to contextualise the findings of the case and promote further discussion in the context of nurse leaders. The paper suggests that comparisons can be made between school principals and nurse leaders.
The role of the elementary school principal — as perceived by Israeli principals an attempt at role analysis

NASA Astrophysics Data System (ADS)

Kremer, Lya

1983-03-01

The study aimed to define the role of principalship, necessary because of the conflicting loyalties and responsibilities inherent in this role. Four `facets' were used to classify areas of principals' activities, from which a questionnaire was constructed. Ninety principals, representing most of those in the northern part of Israel, participated in the project. On the basis of the questionnaire, they related their role activities to the degree of autonomy they felt they were granted. The findings identify the main factors in the role of the principal and show that principals' activities may be defined according to (a) the degree to which they have been planned in advance or carried out ad hoc; (b) their professional or bureaucratic character; (c) the goals which they are meant to serve and whether their aim is task/product-or person-orientated. In all of these areas the principal can act with varying degrees of autonomy. The techniques employed in obtaining and analyzing the results offer a means of creating and comparing principals' profiles, hence also of indicating the position of the principal in the more general system; producing a typology of administrative styles; and identifying personal styles of principalship.
Motor Imagery Learning Modulates Functional Connectivity of Multiple Brain Systems in Resting State

PubMed Central

Zhang, Hang; Long, Zhiying; Ge, Ruiyang; Xu, Lele; Jin, Zhen; Yao, Li; Liu, Yijun

2014-01-01

Background Learning motor skills involves subsequent modulation of resting-state functional connectivity in the sensory-motor system. This idea was mostly derived from the investigations on motor execution learning which mainly recruits the processing of sensory-motor information. Behavioral evidences demonstrated that motor skills in our daily lives could be learned through imagery procedures. However, it remains unclear whether the modulation of resting-state functional connectivity also exists in the sensory-motor system after motor imagery learning. Methodology/Principal Findings We performed a fMRI investigation on motor imagery learning from resting state. Based on previous studies, we identified eight sensory and cognitive resting-state networks (RSNs) corresponding to the brain systems and further explored the functional connectivity of these RSNs through the assessments, connectivity and network strengths before and after the two-week consecutive learning. Two intriguing results were revealed: (1) The sensory RSNs, specifically sensory-motor and lateral visual networks exhibited greater connectivity strengths in precuneus and fusiform gyrus after learning; (2) Decreased network strength induced by learning was proved in the default mode network, a cognitive RSN. Conclusions/Significance These results indicated that resting-state functional connectivity could be modulated by motor imagery learning in multiple brain systems, and such modulation displayed in the sensory-motor, visual and default brain systems may be associated with the establishment of motor schema and the regulation of introspective thought. These findings further revealed the neural substrates underlying motor skill learning and potentially provided new insights into the therapeutic benefits of motor imagery learning. PMID:24465577
Role of 5-HT3 Receptor on Food Intake in Fed and Fasted Mice

PubMed Central

Li, Bingjin; Shao, Dongyuan; Luo, Yungang; Wang, Pu; Liu, Changhong; Zhang, Xingyi; Cui, Ranji

2015-01-01

Background Many studies have shown that 5-hydroxytryptamine (5-HT) receptor subtypes are involved in the regulation of feeding behavior. However, the relative contribution of 5-HT3 receptor remains unclear. The present study was aimed to investigate the role of 5-HT3 receptor in control of feeding behavior in fed and fasted mice. Methodology/Principal Findings Food intake and expression of c-Fos, tyrosine hydroxylase (TH), proopiomelanocortin (POMC) and 5-HT in the brain were examined after acute treatment with 5-HT3 receptor agonist SR-57227 alone or in combination with 5-HT3 receptor antagonist ondansetron. Food intake was significantly inhibited within 3 h after acute treatment with SR 57227 in fasted mice but not fed mice, and this inhibition was blocked by ondansetron. Immunohistochemical study revealed that fasting-induced c-Fos expression was further enhanced by SR 57227 in the brainstem and the hypothalamus, and this enhancement was also blocked by ondansetron. Furthermore, the fasting-induced downregulation of POMC expression in the hypothalamus and the TH expression in the brain stem was blocked by SR 57227 in the fasted mice, and this effect of SR 57227 was also antagonized by ondansetron. Conclusion/Significance Taken together, our findings suggest that the effect of SR 57227 on the control of feeding behavior in fasted mice may be, at least partially, related to the c-Fos expression in hypothalamus and brain stem, as well as POMC system in the hypothalamus and the TH system in the brain stem. PMID:25789930
The variance needed to accurately describe jump height from vertical ground reaction force data.

PubMed

Richter, Chris; McGuinness, Kevin; O'Connor, Noel E; Moran, Kieran

2014-12-01

In functional principal component analysis (fPCA) a threshold is chosen to define the number of retained principal components, which corresponds to the amount of preserved information. A variety of thresholds have been used in previous studies and the chosen threshold is often not evaluated. The aim of this study is to identify the optimal threshold that preserves the information needed to describe a jump height accurately utilizing vertical ground reaction force (vGRF) curves. To find an optimal threshold, a neural network was used to predict jump height from vGRF curve measures generated using different fPCA thresholds. The findings indicate that a threshold from 99% to 99.9% (6-11 principal components) is optimal for describing jump height, as these thresholds generated significantly lower jump height prediction errors than other thresholds.
Autonomy for School Leaders

ERIC Educational Resources Information Center

Eck, Jim; Goodwin, Bryan

2010-01-01

A conversation has emerged in education circles over how much latitude or autonomy principals should have. So how much autonomy should superintendents give principals, and how much is too much? The authors report on some relevant findings in research by McREL, a federal research lab, that may answer this question. McREL's meta-analysis of research…
School Principals in Southern Thailand: Exploring Trust with Community Leaders during Conflict

ERIC Educational Resources Information Center

Brooks, Melanie C.

2015-01-01

This article reports findings from a case study of school principals in Southern Thailand who work in areas targeted by Muslim separatist groups. Data were gathered and analyzed using a conceptual framework that conceived of trust as five interrelated constructs: benevolence, honesty, openness, reliability, and competence. This study builds on…
Principals' Perceptions of "Quality" in Mauritian Schools Using the Baldrige Framework

ERIC Educational Resources Information Center

Ah-Teck, Jean Claude; Starr, Karen

2013-01-01

Purpose: This article aims to report the findings of a research project exploring Mauritian principals' receptivity to the main tenets inherent in Total Quality Management (TQM). The Malcolm Baldrige National Quality Award (MBNQA) framework (aligned with, and an outcome of, the TQM movement) provides a set of criteria for organizational quality…
The Unsung Role of the Career Assistant Principal.

ERIC Educational Resources Information Center

Marshall, Catherine

Common views of the assistant principal (AP) as the "Marine Corps sergeant type" with nowhere better to be are outdated. Career APs have diverse roles in school administration, often including, but not limited to, discipline. Many career APs find rewards in working with children and put high value on having a balanced personal life. Two…
Principals' Transformational and Transactional Leadership Style and Job Satisfaction of College Teachers

ERIC Educational Resources Information Center

Nazim, Fareena

2016-01-01

Leadership style is the general way a leader behaves towards his subordinates for attaining objectives. There are two major dimensions of leadership i.e. transformational leadership and transactional leadership. The objective of the present study was to find out the relationship between leadership styles of principals and job satisfaction of…
A Look at Cuban Schools: What Is Cuba Doing Right?

ERIC Educational Resources Information Center

Hunt, Barbara C.

2003-01-01

A retired elementary school principal, who first visited Cuba as an exchange student, returns 46 years later as an international consultant and finds that the Cubans have made health care and education the top priorities of their society with strong principals and a solid system of supervision and evaluation. (Author/MLF)
From Mr. Wameke to Mr. Rivelle to Mr. Woodman: Images of Principals in Film and Television.

ERIC Educational Resources Information Center

Glanz, Jeffrey

Despite burgeoning literature that acknowledges the importance of the principalship in achieving and maintaining school effectiveness, principals have been depicted unfavorably in film and television as insecure autocrats, petty bureaucrats, and classic buffoons. This paper presents findings of a study that not only catalogued images of principals…
The Impact of Principal Training in Diffusion of Innovation Theory on Fidelity of Implementation

ERIC Educational Resources Information Center

Petruzzelli, Anthony

2010-01-01

Districts and schools are constantly trying to find ways to increase student achievement. Research has shown a significant correlation between principal leadership skills and increased student achievement. Research has also shown a correlation between fidelity of implementation of new innovations and positive outcomes. This purpose of this study…
Teachers' Perceptions Regarding School Principals' Coaching Skills

ERIC Educational Resources Information Center

Yirci, Ramazan; Özdemir, Tuncay Yavuz; Kartal, Seçil Eda; Kocabas, Ibrahim

2014-01-01

The purpose of this study was to find out teachers' perceptions about school principals' coaching skills. The study was carried out within qualitative research methods. The study group included 76 teachers in Elazig and 73 teachers in Kahramanmaras provinces of Turkey. All the data were processed using Nvivo 9 software. The results indicate that…
High School Teachers' Perceptions regarding Principals' Ethical Leadership in Turkey

ERIC Educational Resources Information Center

Karakose, Turgut

2007-01-01

This study has been carried out in order to determine to what extent principals demonstrate ethical leadership behaviors, and to present suggestions on the strength of these findings. The study has a descriptive quality in evaluating the teachers' perceptions and uses the Ethical Leadership Scale (ELS) developed by Yilmaz (2006), so as to…
Partnering Principal and Teacher Candidates: Exploring a Virtual Coaching Model in Teacher Education

ERIC Educational Resources Information Center

Stapleton, Joy; Tschida, Christina; Cuthrell, Kristen

2017-01-01

Colleges of education are constantly searching for innovations to develop stronger graduates. This paper describes and shares findings from a study of a virtual coaching partnership model that links a principal candidate with a teacher candidate. Through the use of existing virtual coaching software, this model provides teacher candidates with…

Instructional Leadership in Compulsory Schools in Iceland and the Role of School Principals

ERIC Educational Resources Information Center

Hansen, Börkur; Lárusdóttir, Steinunn Helga

2015-01-01

The purpose of this paper is to present findings from a study of instructional leadership in 20 Icelandic compulsory schools. More specifically, the perceptions of staff concerning supervision of instruction, and the views of principals regarding their role as supervisors of instructional development. Data was collected with questionnaires from…
The Principal's Role in Setting School Climate (for School Improvement).

ERIC Educational Resources Information Center

Hall, Gene E.

Given that principals play a role in setting school climate, this paper focuses on how this actually happens. First, the paper explores different criteria and variables as possible frameworks for defining the term "climate." This task is complicated by problems in identifying consensus findings due to weak variable definitions and lack…
The Effective Practices and Beliefs of School Principals in High Achieving Hispanic Majority Mid-Level Schools

ERIC Educational Resources Information Center

Briseno, Johnny

2010-01-01

This qualitative phenomenological research study used narrative inquiry to investigate the effective practices and beliefs of 10 Texas principals in high achieving majority Hispanic mid-level schools. Participant interviews were analyzed using the Creswell (2007) six step method for analyzing phenomenological studies. Findings from this study…
Fast and stable algorithms for computing the principal square root of a complex matrix

NASA Technical Reports Server (NTRS)

Shieh, Leang S.; Lian, Sui R.; Mcinnis, Bayliss C.

1987-01-01

This note presents recursive algorithms that are rapidly convergent and more stable for finding the principal square root of a complex matrix. Also, the developed algorithms are utilized to derive the fast and stable matrix sign algorithms which are useful in developing applications to control system problems.
Finding Common Ground: Teacher Leaders and Principals Speak out about Teacher Leadership

ERIC Educational Resources Information Center

Weiner, Jennie Miles

2011-01-01

This study investigates how a small group of teacher leaders and their principals, participating in a teacher leadership program called the teacher connector (TC), understand teacher leadership and its impact on their practice. TCs' responsibilities were typical of teacher leaders; thus, their experiences can provide insights into teacher leaders'…
Time-Span of Discretion and Administrative Work in School Systems: Results of a Pilot Study.

ERIC Educational Resources Information Center

Allison, Derek J.; Morfitt, Grace

1996-01-01

Investigated Elliott Jaques's theories of organizational depth structure and timespan of discretion in two Ontario school systems. Both superintendents and principals were working at two-year timespans; system directors worked at a maximum three-year timespan. Findings imply that principals' responsibilities resemble those of assistant…
77 FR 35408 - Proposed Collection; Comment Request: Process Evaluation of the Early Independence Award (EIA...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-13

...), will publish periodic summaries of proposed projects to be submitted to the Office of Management and... Independence Principal Investigators, and (5) assess the support provided by the Host Institutions to the Early Independence Principal Investigators. The findings will provide valuable information concerning (1) aspects of...
Why Did Principals and Teachers Respond Differently to Curriculum Reform?

ERIC Educational Resources Information Center

Ng, Shun Wing

2009-01-01

This article presents the finding of an interim evaluation survey commissioned by the Education Bureau of Hong Kong on the effectiveness of the curriculum reform initiated in 2001. Drawing upon change theories for analysis of the study, the article examines the perceptions of both principals and teachers on the effectiveness of short-term…
Female Middle School Principals' Voices: Implications for School Leadership Preparation

ERIC Educational Resources Information Center

Jones, Cathy; Ovando, Martha; High, Cynthia

2009-01-01

This study was an attempt to add the voices of women to the discourse of school leadership. It focused on the nature of the middle school leadership experiences of three female middle school principals, their social interactions based on gender role expectations and their own leadership perspectives. Findings suggest that middle school leadership…
Job Satisfaction: Factor Analysis of Greek Primary School Principals' Perceptions

ERIC Educational Resources Information Center

Saiti, Anna; Fassoulis, Konstantinos

2012-01-01

Purpose: The purpose of this paper is to investigate the factors that affect the level of job satisfaction that school principals experience and, based on the findings, to suggest policies or techniques for improving it. Design/methodology/approach: Questionnaires were administered to 180 primary school heads in 13 prefectures--one from each of…
Relationships between Association of Research Libraries (ARL) Statistics and Bibliometric Indicators: A Principal Components Analysis

ERIC Educational Resources Information Center

Hendrix, Dean

2010-01-01

This study analyzed 2005-2006 Web of Science bibliometric data from institutions belonging to the Association of Research Libraries (ARL) and corresponding ARL statistics to find any associations between indicators from the two data sets. Principal components analysis on 36 variables from 103 universities revealed obvious associations between…
Leadership as Social Control: The High School Principalship.

ERIC Educational Resources Information Center

Gougeon, Thomas D.

This paper highlights the findings of Gougeon's 1989 study of high school principals of schools with grade configurations 9 through 12 in the state of Washington, a study based on the Principal Leadership as Social Control (PLASC) theory. Accordingly, the first section describes the PLASC theory as social control of teachers through power- and…
Genetic Structure of Chinese Indigenous Goats and the Special Geographical Structure in the Southwest China as a Geographic Barrier Driving the Fragmentation of a Large Population

PubMed Central

Xu, Lingyang; Liu, Gang; Wang, Zhigang; Zhao, Fuping; Zhang, Li; Han, Xu; Du, Lixin; Liu, Chousheng

2014-01-01

Background China has numerous native domestic goat breeds, however, extensive studies are focused on the genetic diversity within the fewer breeds and limited regions, the population demograogic history and origin of Chinese goats are still unclear. The roles of geographical structure have not been analyzed in Chinese goat domestic process. In this study, the genetic relationships of Chinese indigenous goat populations were evaluated using 30 microsatellite markers. Methodology/Principal Findings Forty Chinese indigenous populations containing 2078 goats were sampled from different geographic regions of China. Moderate genetic diversity at the population level (HS of 0.644) and high population diversity at the species level (HT value of 0.737) were estimated. Significant moderate population differentiation was detected (FST value of 0.129). Significant excess homozygosity (FIS of 0.105) and recent population bottlenecks were detected in thirty-six populations. Neighbour-joining tree, principal components analysis and Bayesian clusters all revealed that Chinese goat populations could be subdivided into at least four genetic clusters: Southwest China, South China, Northwest China and East China. It was observed that the genetic diversity of Northern China goats was highest among these clusters. The results here suggested that the goat populations in Southwest China might be the earliest domestic goats in China. Conclusions/Significance Our results suggested that the current genetic structure of Chinese goats were resulted from the special geographical structure, especially in the Western China, and the Western goat populations had been separated by the geographic structure (Hengduan Mountains and Qinling Mountains-Huaihe River Line) into two clusters: the Southwest and Northwest. It also indicated that the current genetic structure was caused by the geographical origin mainly, in close accordance with the human’s migration history throughout China. This study provides a fundamental genetic profile for the conservation of these populations and better to understand the domestication process and origin of Chinese goats. PMID:24718092
Organizational health and the achievement level of students in science at the secondary-level schools in Sri Lanka

NASA Astrophysics Data System (ADS)

Pakkeer-Jaufar, Pakkeer Cadermohideen

This study sought to identify those organizational health factors that might have overriding influence on the achievement level of students in science in Sri Lankan secondary schools. This study involved 752 students, 33 science teachers, and 10 principals from two different districts, Ampara and Colombo, in Sri Lanka. Ten Tamil medium, secondary level, public schools were selected to participate in this study. Data were collected using four types of instruments: a questionnaire for pupils; interview schedules for science teachers and principals; checklists for classroom/school facilities, science laboratory facilities, and science practicals; and a science achievement test. The analysis focused on the collective perceptions of students, science teachers, and principals. Regression and path analyses were used as major analysis techniques, and the qualitative data provided by science teachers and principals were considered for a crosschecking of the quantitative inferences. The researcher found teacher affiliation, academic emphasis, and instructional leadership of the principal, in descending order, were the overriding influential factors on the achievement level of students in science in Sri Lankan secondary schools. At the same time a similar descending order was found in their mean values and qualities. The researcher concluded that increasing the quality of the organizational health factors in Sri Lankan secondary schools would result in improved better achievement in science. The findings further indicate that instructional leadership of the principal had both direct and indirect effects on students' achievement in science when academic emphasis and teacher affiliation were taken into account. In addition, the resource support of the principal did not make any difference in students' science achievement and the findings stress the availability of the resources for individual students instead of assuming the general facilities of the school are available to all students of the school.
Application Potential of Nanocrystalline Ribbons Still Pending

NASA Astrophysics Data System (ADS)

Butvin, Pavol; Butvinová, Beata; Švec, Peter; Sitek, Jozef

2010-09-01

Nanocrystalline soft-magnetic ribbons promised a wide-spread practical use when introduced at the beginning of nineties. After 20 years of extensive research there are still unclear material problems which are thought to be the principal reason why these materials show but marginal use. Poorly controllable magnetic anisotropy due to spontaneous intrinsic macroscopic stress that comes from an inevitable heterogeneity of the ribbon materials is pointed to in this work. Certain stress-based mechanisms are shown to induce the unintended anisotropy in the already familiar Finemets as well as in the newer Hitperms. Hysteresis loops, domain structure and power loss is used to reveal the anisotropy consequences and particular connected but still unanswered questions are pinpointed.
Administrative Stressors and Islamic Coping Strategies Among Muslim Primary Principals in Malaysia: A Mixed Method Study.

PubMed

Tahir, Lokman Mohd; Khan, Aqeel; Musah, Mohammed Borhandden; Ahmad, Roslee; Daud, Khadijah; Al-Hudawi, Shafeeq Hussain Vazhathodi; Musta'Amal, Aede Hatib; Talib, Rohaya

2017-11-18

Principals are school leaders who experienced stress while leading their schools towards excellence. However, principals stress experiences are always ignored and least studied. This mixed-methods study investigates primary principals' stress experiences and their Islamic coping strategies used in incapacitating the stress experiences. A total of 216 Muslim primary principals across different gender, types of schools and years of experiences as school leaders responded to the administrative stress and the Islamic coping strategies items. In addition, seven primary principals were purposefully selected and interviewed in exploring their reasons of using Islamic coping strategies for their relieving process. Results discovered that primary principals experienced fairly stress level and they perceived managing students' academic achievement was the most stressor followed by managing teachers' capabilities. Although findings revealed that no significant differences in terms primary principals' demographics; male primary principals, and experienced between 6 and 10 years and positioned in schools with least students (SLS) category have slightly higher level of stress. In terms of Islamic coping strategies used by primary principals, saying dhua to Allah, performing dhikir and reciting the Yassen are selected coping approaches employed in handling their stress. From interviews, primary principals also revealed that they used Islamic religious approaches as part of meaningful activities not just to overcoming their stress but also as part of religious approaches in remembering Allah, thinking back their past mistakes as part of the Muhasabah process. Therefore, we believed that religious approaches should be taken into consideration in principals' training as it provides peaceful and treatment in managing principals' stress issue.
SELF IMAGES AND COMMUNITY IMAGES OF THE ELEMENTARY SCHOOL PRINCIPAL--FINDINGS AND IMPLICATIONS OF A SOCIOLOGICAL INQUIRY.

ERIC Educational Resources Information Center

FOSKETT, JOHN M.; WOLCOTT, HARRY F.

THE SYSTEM OF RULES THAT GUIDES THE BEHAVIOR OF ELEMENTARY SCHOOL PRINCIPALS WAS INVESTIGATED. THIS BODY OF RULES, TERMED "THE NORMATIVE STRUCTURE OF THE COMMUNITY AS IT PERTAINS TO SCHOOL ADMINISTRATORS," WAS STUDIED BY MEANS OF AN INSTRUMENT CALLED THE "ROLE NORM INVENTORY." SEPARATE INVENTORIES WERE DEVELOPED FOR ELEMENTARY…
School Recognition: Principals, Do You Know Who You Are?

ERIC Educational Resources Information Center

Schoer, Lisa Unger

2014-01-01

For high school and middle school principals, the ability to create and maintain positive recognition and identity both personally and for the school is crucial for support from all stakeholders. Finding proactive ways to do this is not much different than the way a large corporation develops a campaign for a major product. Nine principles for…
Protecting the "Impressionable Minds" from the "Impressionable Minds": The Third-Person Effect and Student Speech

ERIC Educational Resources Information Center

Maksl, Adam; Schraum, Brian

2012-01-01

Support for student expression and First Amendment attitudes were measured among Missouri high school principals (n = 86). Findings demonstrated that the third-person effect was a significant predictor of these attitudes. The more principals perceived mass media to affect others over themselves, the less supportive they were for student free…
Principals' Perceptions of Professional Development in High- and Low-Performing High-Poverty Schools

ERIC Educational Resources Information Center

Moore, Sheila; Kochan, Frances

2013-01-01

This is the second part of a two-part study examining issues related to professional development in high-poverty schools. The findings from the initial study indicated that principals in high-poverty, high-performing schools perceived higher levels of implementation of quality professional development standards in their schools than did principals…

Little Things Count: Principal and New Teacher Feedback about District Support in the Hiring Process

ERIC Educational Resources Information Center

Mac Iver, Martha Abele

2006-01-01

This study examines the role of district central offices in recruiting and hiring teachers and principals in an urban setting. Findings indicate many district human resources offices, particularly in urban settings, often lose quality candidates to suburban districts whose HR offices are better organized and pay closer attention to managing…
The Faith Is the Pace: Educational Perspectives of Three Women Principals of Jewish, Christian, and Muslim Ultra-Orthodox Schools

ERIC Educational Resources Information Center

Karnieli, Mira

2014-01-01

Israel is a multicultural state where ultra-Orthodox groups run their own separate schools. The present phenomenological study examined and compared the management patterns and educational emphases of three women principals of religious schools (Muslim, Christian [Franciscan], and ultra-Orthodox Jewish). The findings show that the ultra-Orthodox…
Developing School Leaders: Practitioner Growth during an Advanced Leadership Development Program for Principals and Administrator-Trained Teachers

ERIC Educational Resources Information Center

Browne-Ferrigno, Tricia

2007-01-01

This article shares findings from an exploratory case study about an advanced school leadership development program designed specifically for practicing principals and administrator-trained teachers. The program was designed to help a high-need rural district transform its principalship from school management into learner-center leadership while…
Conversion of a Large, Urban High School to Small Schools: Leadership Challenges and Opportunities

ERIC Educational Resources Information Center

Nehring, James; Lohmeier, Jill H.; Colombo, Michaela

2009-01-01

This article reports findings from a study of the experiences of 11 school principals who are leading the conversion of a large, comprehensive, urban high school into six thematic small schools. Specifically, this study addresses the question, What do high school principals identify as the leadership challenges and opportunities embedded in the…
A Systems Theory Approach to the District Central Office's Role in School-Level Improvement

ERIC Educational Resources Information Center

Mania-Singer, Jackie

2017-01-01

This qualitative case study used General Systems Theory and social network analysis to explore the relationships between the members of a district central office and principals of elementary schools within an urban school district in the Midwest. Findings revealed sparse relationships between members of the district central office and principals,…
What School Leaders Are Doing to Support a Culture of Character: An Exploratory Study with Preschools in Singapore

ERIC Educational Resources Information Center

Carter, Margaret-Anne; Dasson, Merilyn

2017-01-01

This article discusses an exploratory study, reporting the practices of five principals leading character development in early childhood centers in Singapore. Acknowledging variations in leadership style, the pooled focus group findings show the common denominator is the principals' paradigm of authentic leadership informing a service-oriented…
(Re)Thinking Teacher Networking in the Russian Federation

ERIC Educational Resources Information Center

Lapham, Kate; Lindemann-Komarova, Sarah

2013-01-01

This article presents the findings of research in Russia on the degree to which teachers and school principals are active and how they currently network with their colleagues. It builds on the work of David Frost and John Bangs (2012) on teacher self-efficacy using a survey and semi-structured interviews with teachers and principals to collect…
Leadership, Motivation, and Teamwork Behaviors of Principal Investigator's in Interdisciplinary Teams: A Synthesis of Research

ERIC Educational Resources Information Center

Adams, Brittany L.; Cain, Holly Reed; Giraud, Vivana; Stedman, Nicole L. P.

2012-01-01

Increased demand, limited resources, knowledge gaps, and seemingly less time to produce results are the challenges facing researchers and others in higher education today. Working together across disciplines is almost a requirement to stay afloat in the competitive arena most principal investigators are finding themselves in. This study sought to…
Transformational Leadership and Globalization: Attitudes of School Principals in Kuwait

ERIC Educational Resources Information Center

Alsaeedi, Farraj; Male, Trevor

2013-01-01

The study explores the attitudes of a sample of school principals in a Kuwaiti local authority towards the need for transformational leadership, the use of its behaviours, whether these school leaders are ready to behave in diverse ways or whether there are barriers that prevent them from acting in such a manner. The findings of this study…
A Synthesis of Reviews of Research on Principal Leadership in East Asia

ERIC Educational Resources Information Center

Walker, Allan; Hallinger, Philip

2015-01-01

Purpose: The purpose of this paper is to synthesize findings from five systematic reviews of research on principal leadership in East Asia contained in this special issue. The goal is to identify commonalities as well as differences concerning both approaches to research and the enactment of school leadership within this rapidly developing and…
Principals Discuss Early Implementation of the ASSISTments Online Homework Tutor for Mathematics. ASSISTments Efficacy Study Report 2

ERIC Educational Resources Information Center

Fairman, Janet; Porter, Michael; Fisher, Susannah

2015-01-01

This report presents the findings from interviews with principals about their schools' participation in the ASSISTments efficacy study on seventh-grade mathematics. The purpose of the interviews was to explore the following areas: To what extent schools had policies or expectations regarding homework practice and completion; To what extent schools…
Fit for Purpose? Western Australian Insights into the Efficacy of Principal Preparation

ERIC Educational Resources Information Center

Clarke, Simon; Wildy, Helen; Styles, Irene

2011-01-01

Purpose: This paper aims to highlight what principals consider their most severe challenges in the first three years of appointment and the extent to which they believe they were adequately prepared to meet these challenges. Design/methodology/approach: The paper reports on the initial Western Australian findings of a survey developed for Phase…
Leadership Styles and School Performance: Is There a Gender Difference in Expectations for Teachers?

ERIC Educational Resources Information Center

Magee, Iris Denise

2012-01-01

In this paper, the research on the perceptions of gender differences in leadership styles is explored. The study also attempts to determine whether there are differences in overall school performance for male versus female school principals. The methodology involved a mixed-model ANOVA analysis of findings from 31 principals and 236 teachers…
Principalship in an Indonesian School Context: Can Principal Decision-Making Styles Significantly Predict Teacher Job Satisfaction?

ERIC Educational Resources Information Center

Hariri, Hasan; Monypenny, Richard; Prideaux, Murray

2012-01-01

This paper examines relationships between teacher-perceived principal decision-making styles and teacher job satisfaction in schools in Lampung Province, Indonesia. We use the General Decision-making Style instrument, the Job Satisfaction Survey and a demographic questionnaire developed for this study. Our findings show that: 12 out of the 15…
Rethinking High School Principal Compensation Practices: An Analysis of Salaries in South Carolina and Theoretical Models

ERIC Educational Resources Information Center

Newman, Tim A.

2012-01-01

This study described the current state of principal salaries in South Carolina and compared the salaries of similar size schools by specific report card performance and demographic variables. Based on the findings, theoretical models were proposed, and comparisons were made with current salary data. School boards, human resource personnel and…
Using Curriculum-Based Measurement to Improve Achievement

ERIC Educational Resources Information Center

Clarke, Suzanne

2009-01-01

Response to intervention (RTI) is on the radar screen of most principals these days--finding out what it is, how it can improve teaching and learning, and what needs to be done to implement it effectively. One critical component of RTI that will require particular attention from principals is student progress monitoring, which is required in every…
What Does School Size Do: Safety Perceptions of Educators and Students

ERIC Educational Resources Information Center

Bakioglu, Aysen; Geyin, Cigdem

2009-01-01

The purpose of this study is to find out how teachers, principals, vice principals and students perceive school safety and how that differs related to school size. 194 educators and 1420 students' views were elicited by two self-deviced school safety inventories conducted in 10 state high schools in Istanbul in 2008. Cronbach alpha value for…
White Principals Examine Power, Privilege, and Identity: The Challenge of Leading for Equity

ERIC Educational Resources Information Center

McCann, Julie McLaughlin

2012-01-01

The purpose of this qualitative study was to examine the experience of white principals in understanding their white identity, privilege, and power as they worked to implement socially-just and culturally proficient schools. The findings offer insights into the following questions: 1) How do white school leaders view white identity and the impact,…
Prospective Principals' Openness to Organizational Change and the Education of African American Students

ERIC Educational Resources Information Center

Cooper, Robert; Peebles, Lucretia D.

2008-01-01

The purpose of this article is to report the findings of a research study that sought to examine and describe prospective principals? attitudes and perceptions regarding current efforts to transform urban education for the betterment of African American Students. Given the current wave of reforms targeted at schools serving large numbers of…
Educational Leadership and Market Values: A Study of School Principals in Iceland

ERIC Educational Resources Information Center

Lárusdóttir, Steinunn Helga

2014-01-01

This article reports on the findings of a larger case study about the impact of values on educational leaders in Iceland. The environment of Icelandic schools has changed considerably in recent years. These changes have affected schools and changed the nature and scope of principals' work. Scholars have argued that these changes are primarily…

Balancing Personal and Professional Responsibilities. Research Brief

ERIC Educational Resources Information Center

Walker, Karen

2008-01-01

A high school principal seldom has a day that goes according to plan. The principal's schedule more often than not, is dictated by others and routinely extends several hours beyond a regular school day. It is a job that could easily consume one's life, to the detriment of finding and maintaining any semblance of balance between their professional…
Intertwined electron-nuclear motion in frustrated double ionization in driven heteronuclear molecules

NASA Astrophysics Data System (ADS)

Vilà, A.; Zhu, J.; Scrinzi, A.; Emmanouilidou, A.

2018-03-01

We study frustrated double ionization (FDI) in a strongly-driven heteronuclear molecule HeH+ and compare with H2. We compute the probability distribution of the sum of the final kinetic energies of the nuclei for strongly-driven HeH+. We find that this distribution has more than one peak for strongly-driven HeH+, a feature we do not find to be present for strongly-driven H2. Moreover, we compute the probability distribution of the principal quantum number n of FDI. We find that this distribution has several peaks for strongly-driven HeH+, while the respective distribution has one main peak and a ‘shoulder’ at lower principal quantum numbers n for strongly-driven H2. Surprisingly, we find this feature to be a clear signature of the intertwined electron-nuclear motion.
Using principal component analysis to understand the variability of PDS 456

NASA Astrophysics Data System (ADS)

Parker, M. L.; Reeves, J. N.; Matzeu, G. A.; Buisson, D. J. K.; Fabian, A. C.

2018-02-01

We present a spectral-variability analysis of the low-redshift quasar PDS 456 using principal component analysis. In the XMM-Newton data, we find a strong peak in the first principal component at the energy of the Fe absorption line from the highly blueshifted outflow. This indicates that the absorption feature is more variable than the continuum, and that it is responding to the continuum. We find qualitatively different behaviour in the Suzaku data, which is dominated by changes in the column density of neutral absorption. In this case, we find no evidence of the absorption produced by the highly ionized gas being correlated with this variability. Additionally, we perform simulations of the source variability, and demonstrate that PCA can trivially distinguish between outflow variability correlated, anticorrelated and un-correlated with the continuum flux. Here, the observed anticorrelation between the absorption line equivalent width and the continuum flux may be due to the ionization of the wind responding to the continuum. Finally, we compare our results with those found in the narrow-line Seyfert 1 IRAS 13224-3809. We find that the Fe K UFO feature is sharper and more prominent in PDS 456, but that it lacks the lower energy features from lighter elements found in IRAS 13224-3809, presumably due to differences in ionization.
Can Good Principals Keep Teachers in Disadvantaged Schools? Linking Principal Effectiveness to Teacher Satisfaction and Turnover in Hard-to-Staff Environments

ERIC Educational Resources Information Center

Grissom, Jason A.

2011-01-01

Background: High rates of teacher turnover likely mean greater school instability, disruption of curricular cohesiveness, and a continual need to hire inexperienced teachers, who typically are less effective, as replacements for teachers who leave. Unfortunately, research consistently finds that teachers who work in schools with large numbers of…
Societal Culture and the Changing Role of School Principals in the Post-Soviet Era: The Case of Kazakhstan

ERIC Educational Resources Information Center

Yakavets, Natallia

2016-01-01

Purpose: The purpose of this paper is to explore the impact of societal and cultural factors on the practices and perceptions of school principals in Kazakhstan. Design/methodology/approach: The paper draws on empirical data collected in Kazakhstan over two years in the course of an international, collaborative, multi-stranded project. Findings:…
Why Can't We Have It All? The Conflict between the Principalship and Motherhood

ERIC Educational Resources Information Center

Jordan, Jacqueline S.

2012-01-01

Being a principal in today's high-stakes environment is a highly demanding job. Much has been written about the stress principals now face in responding to the increased demands and pressures associated with the role. Districts nationwide continue go to great lengths to find administrators of the highest caliber capable of meeting these…
The Dynamics and Intricacy of Budgeting in Secondary Schools in Lesotho: Case Studies of Three High Schools

ERIC Educational Resources Information Center

Mncube, V. S.; Makhasane, Sekitla

2013-01-01

This paper reports on the qualitative study that used in-depth interviews and document reviews on financial management practices in their schools. The participants were school principals of the case study schools. The findings of the study highlighted problems regarding the implementation of the policy--despite the Manual for Principals of…
Leading in Conflict Zones: Principal Perceptions of Armed Military Guards in Southern Thai Schools

ERIC Educational Resources Information Center

Brooks, Melanie C.; Sungtong, Ekkarin

2014-01-01

The purpose of this study was to understand the experiences, issues, and concerns Thai government school principals have about the presence of armed military guards and how this helps or impedes their school leadership. Data were taken from a larger ongoing study of this topic and the findings suggest that the military protection of schools…
Value Added: Best Practices for the Utilization of Assistant Principals' Skills and Knowledge In Schools

ERIC Educational Resources Information Center

Hilliard, Ann T.; Newsome, Sandra S.

2013-01-01

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…
K-12 School Leaders and School Crisis: An Exploration of Principals' School Crisis Competencies and Preparedness

ERIC Educational Resources Information Center

McCarty, Sean P.

2012-01-01

On any given day, principals could find themselves faced with a situation that could define their roles as crisis leaders. This dissertation research offers an exploratory study in the field of crisis response and educational leadership. From experts in the field of crisis response, the author compiled a list of crisis management competencies…
A Study of Superintendents' Power and Leadership Styles as Perceived by Local Teacher Association Representatives and Secondary School Principals in Alabama Public Schools.

ERIC Educational Resources Information Center

Pounders, Barbara; And Others

The situational leadership model identifies four leadership styles--telling, selling, participating, and delegating. This paper discusses the initial findings of a study that examined the role of superintendents in Alabama. The study sought to determine if secondary school principals and local teacher-association representatives differed in their…
Creating a System for Data-Driven Decision-Making: Applying the Principal-Agent Framework

ERIC Educational Resources Information Center

Wohlstetter, Priscilla; Datnow, Amanda; Park, Vicki

2008-01-01

The purpose of this article is to improve our understanding of data-driven decision-making strategies that are initiated at the district or system level. We apply principal-agent theory to the analysis of qualitative data gathered in a case study of 4 urban school systems. Our findings suggest educators at the school level need not only systemic…
Quantitative descriptive analysis and principal component analysis for sensory characterization of Indian milk product cham-cham.

PubMed

Puri, Ritika; Khamrui, Kaushik; Khetra, Yogesh; Malhotra, Ravinder; Devraja, H C

2016-02-01

Promising development and expansion in the market of cham-cham, a traditional Indian dairy product is expected in the coming future with the organized production of this milk product by some large dairies. The objective of this study was to document the extent of variation in sensory properties of market samples of cham-cham collected from four different locations known for their excellence in cham-cham production and to find out the attributes that govern much of variation in sensory scores of this product using quantitative descriptive analysis (QDA) and principal component analysis (PCA). QDA revealed significant (p < 0.05) difference in sensory attributes of cham-cham among the market samples. PCA identified four significant principal components that accounted for 72.4 % of the variation in the sensory data. Factor scores of each of the four principal components which primarily correspond to sweetness/shape/dryness of interior, surface appearance/surface dryness, rancid and firmness attributes specify the location of each market sample along each of the axes in 3-D graphs. These findings demonstrate the utility of quantitative descriptive analysis for identifying and measuring attributes of cham-cham that contribute most to its sensory acceptability.
A single determinant dominates the rate of yeast protein evolution.

PubMed

Drummond, D Allan; Raval, Alpan; Wilke, Claus O

2006-02-01

A gene's rate of sequence evolution is among the most fundamental evolutionary quantities in common use, but what determines evolutionary rates has remained unclear. Here, we carry out the first combined analysis of seven predictors (gene expression level, dispensability, protein abundance, codon adaptation index, gene length, number of protein-protein interactions, and the gene's centrality in the interaction network) previously reported to have independent influences on protein evolutionary rates. Strikingly, our analysis reveals a single dominant variable linked to the number of translation events which explains 40-fold more variation in evolutionary rate than any other, suggesting that protein evolutionary rate has a single major determinant among the seven predictors. The dominant variable explains nearly half the variation in the rate of synonymous and protein evolution. We show that the two most commonly used methods to disentangle the determinants of evolutionary rate, partial correlation analysis and ordinary multivariate regression, produce misleading or spurious results when applied to noisy biological data. We overcome these difficulties by employing principal component regression, a multivariate regression of evolutionary rate against the principal components of the predictor variables. Our results support the hypothesis that translational selection governs the rate of synonymous and protein sequence evolution in yeast.
Fluorescence Intrinsic Characterization of Excitation-Emission Matrix Using Multi-Dimensional Ensemble Empirical Mode Decomposition

PubMed Central

Chang, Chi-Ying; Chang, Chia-Chi; Hsiao, Tzu-Chien

2013-01-01

Excitation-emission matrix (EEM) fluorescence spectroscopy is a noninvasive method for tissue diagnosis and has become important in clinical use. However, the intrinsic characterization of EEM fluorescence remains unclear. Photobleaching and the complexity of the chemical compounds make it difficult to distinguish individual compounds due to overlapping features. Conventional studies use principal component analysis (PCA) for EEM fluorescence analysis, and the relationship between the EEM features extracted by PCA and diseases has been examined. The spectral features of different tissue constituents are not fully separable or clearly defined. Recently, a non-stationary method called multi-dimensional ensemble empirical mode decomposition (MEEMD) was introduced; this method can extract the intrinsic oscillations on multiple spatial scales without loss of information. The aim of this study was to propose a fluorescence spectroscopy system for EEM measurements and to describe a method for extracting the intrinsic characteristics of EEM by MEEMD. The results indicate that, although PCA provides the principal factor for the spectral features associated with chemical compounds, MEEMD can provide additional intrinsic features with more reliable mapping of the chemical compounds. MEEMD has the potential to extract intrinsic fluorescence features and improve the detection of biochemical changes. PMID:24240806
Verbal Counting Moderates Perceptual Biases Found in Children's Cardinality Judgments

ERIC Educational Resources Information Center

Posid, Tasha; Cordes, Sara

2015-01-01

A crucial component of numerical understanding is one's ability to abstract numerical properties regardless of varying perceptual attributes. Evidence from numerical match-to-sample tasks suggests that children find it difficult to match sets based on number in the face of varying perceptual attributes, yet it is unclear whether these findings are…
Stepping stones: Principal career paths and school outcomes.

PubMed

Béteille, Tara; Kalogrides, Demetra; Loeb, Susanna

2012-07-01

More than one out of every five principals leaves their school each year. In some cases, these career changes are driven by the choices of district leadership. In other cases, principals initiate the move, often demonstrating preferences to work in schools with higher achieving students from more advantaged socioeconomic backgrounds. Principals often use schools with many poor or low-achieving students as stepping stones to what they view as more desirable assignments. We use longitudinal data from one large urban school district to study the relationship between principal turnover and school outcomes. We find that principal turnover is, on average, detrimental to school performance. Frequent turnover of school leadership results in lower teacher retention and lower student achievement gains. Leadership changes are particularly harmful for high poverty schools, low-achieving schools, and schools with many inexperienced teachers. These schools not only suffer from high rates of principal turnover but are also unable to attract experienced successors. The negative effect of leadership changes can be mitigated when vacancies are filled by individuals with prior experience leading other schools. However, the majority of new principals in high poverty and low-performing schools lack prior leadership experience and leave when more attractive positions become available in other schools. Copyright © 2012 Elsevier Inc. All rights reserved.
Does Observation of Postural Imbalance Induce a Postural Reaction?

PubMed Central

Tia, Banty; Saimpont, Arnaud; Paizis, Christos; Mourey, France; Fadiga, Luciano; Pozzo, Thierry

2011-01-01

Background Several studies bring evidence that action observation elicits contagious responses during social interactions. However automatic imitative tendencies are generally inhibited and it remains unclear in which conditions mere action observation triggers motor behaviours. In this study, we addressed the question of contagious postural responses when observing human imbalance. Methodology/Principal Findings We recorded participants' body sway while they observed a fixation cross (control condition), an upright point-light display of a gymnast balancing on a rope, and the same point-light display presented upside down. Our results showed that, when the upright stimulus was displayed prior to the inverted one, centre of pressure area and antero-posterior path length were significantly greater in the upright condition compared to the control and upside down conditions. Conclusions/Significance These results demonstrate a contagious postural reaction suggesting a partial inefficiency of inhibitory processes. Further, kinematic information was sufficient to trigger this reaction. The difference recorded between the upright and upside down conditions indicates that the contagion effect was dependent on the integration of gravity constraints by body kinematics. Interestingly, the postural response was sensitive to habituation, and seemed to disappear when the observer was previously shown an inverted display. The motor contagion recorded here is consistent with previous work showing vegetative output during observation of an effortful movement and could indicate that lower level control facilitates contagion effects. PMID:21423622
Global gas chromatography/time-of-flight mass spectrometry (GC/TOFMS)-based metabonomic profiling of lyophilized human feces.

PubMed

Phua, Lee Cheng; Koh, Poh Koon; Cheah, Peh Yean; Ho, Han Kiat; Chan, Eric Chun Yong

2013-10-15

Gas chromatography mass spectrometry (GC/MS)-based fecal metabonomics represents a powerful systems biology approach for elucidating metabolic biomarkers of lower gastrointestinal tract (GIT) diseases. Unlike metabolic profiling of fecal water, the profiling of complete fecal material remains under-explored. Here, a gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) method was developed and validated for the global metabonomic profiling of human feces. Fecal and fecal water metabotypes were also profiled and compared. Additionally, the unclear influence of blood in stool on the fecal metabotype was investigated unprecedentedly. Eighty milligram of lyophilized feces was ultrasonicated with 1mL of methanol:water (8:2) for 30min, followed by centrifugation, drying of supernatant, oximation and trimethylsilylation for 45min. Lyophilized feces demonstrated a more comprehensive metabolic coverage than fecal water, based on the number of chromatographic peaks. Principal component analysis (PCA) indicated occult blood (1mgHb/g feces) exerted a negligible effect on the fecal metabotype. Conversely, a unique metabotype related to feces spiked with gross blood (100mgHb/g feces) was revealed (PCA, R(2)X=0.837, Q(2)=0.794), confirming the potential confounding effect of gross GIT bleeding on the fecal metabotype. This pertinent finding highlights the importance of prudent interpretation of fecal metabonomic data, particularly in GIT diseases where bleeding is prevalent. Copyright © 2013 Elsevier B.V. All rights reserved.
Does Litter Size Variation Affect Models of Terrestrial Carnivore Extinction Risk and Management?

PubMed Central

Devenish-Nelson, Eleanor S.; Stephens, Philip A.; Harris, Stephen; Soulsbury, Carl; Richards, Shane A.

2013-01-01

Background Individual variation in both survival and reproduction has the potential to influence extinction risk. Especially for rare or threatened species, reliable population models should adequately incorporate demographic uncertainty. Here, we focus on an important form of demographic stochasticity: variation in litter sizes. We use terrestrial carnivores as an example taxon, as they are frequently threatened or of economic importance. Since data on intraspecific litter size variation are often sparse, it is unclear what probability distribution should be used to describe the pattern of litter size variation for multiparous carnivores. Methodology/Principal Findings We used litter size data on 32 terrestrial carnivore species to test the fit of 12 probability distributions. The influence of these distributions on quasi-extinction probabilities and the probability of successful disease control was then examined for three canid species – the island fox Urocyon littoralis, the red fox Vulpes vulpes, and the African wild dog Lycaon pictus. Best fitting probability distributions differed among the carnivores examined. However, the discretised normal distribution provided the best fit for the majority of species, because variation among litter-sizes was often small. Importantly, however, the outcomes of demographic models were generally robust to the distribution used. Conclusion/Significance These results provide reassurance for those using demographic modelling for the management of less studied carnivores in which litter size variation is estimated using data from species with similar reproductive attributes. PMID:23469140

Increased Response to β2-Adrenoreceptor Stimulation Augments Inhibition of IKr in Heart Failure Ventricular Myocytes

PubMed Central

Wang, Hegui; Chen, Yanhong; Zhu, Hongjun; Wang, Sen; Zhang, Xiwen; Xu, Dongjie; Cao, Kejiang; Zou, Jiangang

2012-01-01

Background Increasing evidence indicates that the rapid component of delayed rectifier potassium current (IKr) is modulated by α- and β-adrenergic stimulation. However, the role and mechanism regulating IKr through β2-adrenoreceptor (β-AR) stimulation in heart failure (HF) are unclear. Methodology/Principal Findings In the present study, we investigated the effects of fenoterol, a highly selective β2-AR agonist, on IKr in left ventricular myocytes obtained from control and guinea pigs with HF induced by descending aortic banding. IKr was measured by using whole cell patch clamp technique. In control myocytes, superfusion of fenoterol (10 µM) caused a 17% decrease in IKr. In HF myocytes, the same concentration of fenoterol produced a significantly greater decrease (33%) in IKr. These effects were not modified by the incubation of myocytes with CGP-20712A, a β1-AR antagonist, but were abolished by pretreatment of myocytes with ICI-118551, a β2-AR antagonist. An inhibitory cAMP analog, Rp-cAMPS and PKA inhibitor significantly attenuated fenoterol-induced inhibition of IKr in HF myocytes. Moreover, fenoterol markedly prolonged action potential durations at 90% (APD90) repolarization in HF ventricular myocytes. Conclusions The results indicate that inhibition of IKr induced by β2-AR stimulation is increased in HF. The inhibitory effect is likely to be mediated through a cAMP/PKA pathway in HF ventricular myocytes. PMID:23029432
Overtime Work as a Predictor of Major Depressive Episode: A 5-Year Follow-Up of the Whitehall II Study

PubMed Central

Virtanen, Marianna; Stansfeld, Stephen A.; Fuhrer, Rebecca; Ferrie, Jane E.; Kivimäki, Mika

2012-01-01

Background The association between overtime work and depression is still unclear. This study examined the association between overtime work and the onset of a major depressive episode (MDE). Methodology/Principal Findings Prospective cohort study with a baseline examination of working hours, psychological morbidity (an indicator of baseline depression) and depression risk factors in 1991–1993 and a follow-up of major depressive episode in 1997–1999 (mean follow-up 5.8 years) among British civil servants (the Whitehall II study; 1626 men, 497 women, mean age 47 years at baseline). Onset of 12-month MDE was assessed by the Composite International Diagnostic Interview (CIDI) at follow-up. In prospective analysis of participants with no psychological morbidity at baseline, the odds ratio for a subsequent major depressive episode was 2.43 (95% confidence interval 1.11 to 5.30) times higher for those working 11+ hours a day compared to employees working 7–8 hours a day, when adjusted for socio-demographic factors at baseline. Further adjustment for chronic physical disease, smoking, alcohol use, job strain and work-related social support had little effect on this association (odds ratio 2.52; 95% confidence interval 1.12 to 5.65). Conclusions/Significance Data from middle-aged civil servants suggest that working long hours of overtime may predispose to major depressive episodes. PMID:22295106
Sex differences in colonization of gut microbiota from a man with short-term vegetarian and inulin-supplemented diet in germ-free mice.

PubMed

Wang, Jing-Jing; Wang, Jing; Pang, Xiao-Yan; Zhao, Li-Ping; Tian, Ling; Wang, Xing-Peng

2016-10-31

Gnotobiotic mouse model is generally used to evaluate the efficacy of gut microbiota. Sex differences of gut microbiota are acknowledged, yet the effect of recipient's gender on the bacterial colonization remains unclear. Here we inoculated male and female germ-free C57BL/6J mice with fecal bacteria from a man with short-term vegetarian and inulin-supplemented diet. We sequenced bacterial 16S rRNA genes V3-V4 region from donor's feces and recipient's colonic content. Shannon diversity index showed female recipients have higher bacteria diversity than males. Weighted UniFrac principal coordinates analysis revealed the overall structures of male recipient's gut microbiota were significantly separated from those of females, and closer to the donor. Redundancy analysis identified 46 operational taxonomic units (OTUs) differed between the sexes. The relative abundance of 13 OTUs were higher in males, such as Parabacteroides distasonis and Blautia faecis, while 33 OTUs were overrepresented in females, including Clostridium groups and Escherichia fergusonii/Shigella sonnei. Moreover, the interactions of these differential OTUs were sexually distinct. These findings demonstrated that the intestine of male and female mice preferred to accommodate microbiota differently. Therefore, it is necessary to designate the gender of gnotobiotic mice for complete evaluation of modulatory effects of gut microbiota from human feces upon diseases.
Effects of Increased Summer Precipitation and Nitrogen Addition on Root Decomposition in a Temperate Desert

PubMed Central

Zhao, Hongmei; Huang, Gang; Li, Yan; Ma, Jian; Sheng, Jiandong; Jia, Hongtao; Li, Congjuan

2015-01-01

Background Climate change scenarios that include precipitation shifts and nitrogen (N) deposition are impacting carbon (C) budgets in arid ecosystems. Roots constitute an important part of the C cycle, but it is still unclear which factors control root mass loss and nutrient release in arid lands. Methodology/Principal Findings Litterbags were used to investigate the decomposition rate and nutrient dynamics in root litter with water and N-addition treatments in the Gurbantunggut Desert in China. Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue. The loss of root litter and nutrient releases were strongly controlled by the initial lignin content and the lignin:N ratio, as evidenced by the negative correlations between decomposition rate and litter lignin content and the lignin:N ratio. Fine roots of Seriphidium santolinum (with higher initial lignin content) had a slower decomposition rate in comparison to coarse roots. Conclusion/Significance Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert. Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover. PMID:26544050
Incomplete Homogenization of Chemical Recognition Labels Between Formica sanguinea and Formica rufa Ants (Hymenoptera: Formicidae) Living in a Mixed Colony

PubMed Central

Włodarczyk, Tomasz; Szczepaniak, Lech

2014-01-01

Abstract Formica sanguinea Latreille (Hymenoptera: Formicidae) is a slave-making species, i.e., it raids colonies of host species and pillages pupae, which are taken to develop into adult workers in a parasite colony. However, it has been unclear if the coexistence of F. sanguinea with slave workers requires uniformity of cuticular hydrocarbons (CHCs), among which those other than n -alkanes are believed to be the principal nestmate recognition cues utilized by ants. In this study, a mixed colony (MC) of F. sanguinea and Formica rufa L. as a slave species was used to test the hypothesis that CHCs are exchanged between the species. Chemical analysis of hexane extracts from ants’ body surfaces provided evidence for interspecific exchange of alkenes and methyl-branched alkanes. This result was confirmed by behavioral tests during which ants exhibited hostility toward conspecific individuals from the MC but not toward ones from homospecific colonies of their own species. However, it seems that species-specific differences in chemical recognition labels were not eliminated completely because ants from the MC were treated differently depending on whether they were con- or allospecific to the individuals whose behavioral reactions were tested. These findings are discussed in the context of mechanisms of colony's odor formation and effective integration of slaves into parasite colony. PMID:25502026
Sex differences in colonization of gut microbiota from a man with short-term vegetarian and inulin-supplemented diet in germ-free mice

PubMed Central

Wang, Jing-jing; Wang, Jing; Pang, Xiao-yan; Zhao, Li-ping; Tian, Ling; Wang, Xing-peng

2016-01-01

Gnotobiotic mouse model is generally used to evaluate the efficacy of gut microbiota. Sex differences of gut microbiota are acknowledged, yet the effect of recipient’s gender on the bacterial colonization remains unclear. Here we inoculated male and female germ-free C57BL/6J mice with fecal bacteria from a man with short-term vegetarian and inulin-supplemented diet. We sequenced bacterial 16S rRNA genes V3-V4 region from donor’s feces and recipient’s colonic content. Shannon diversity index showed female recipients have higher bacteria diversity than males. Weighted UniFrac principal coordinates analysis revealed the overall structures of male recipient’s gut microbiota were significantly separated from those of females, and closer to the donor. Redundancy analysis identified 46 operational taxonomic units (OTUs) differed between the sexes. The relative abundance of 13 OTUs were higher in males, such as Parabacteroides distasonis and Blautia faecis, while 33 OTUs were overrepresented in females, including Clostridium groups and Escherichia fergusonii/Shigella sonnei. Moreover, the interactions of these differential OTUs were sexually distinct. These findings demonstrated that the intestine of male and female mice preferred to accommodate microbiota differently. Therefore, it is necessary to designate the gender of gnotobiotic mice for complete evaluation of modulatory effects of gut microbiota from human feces upon diseases. PMID:27796317
Paleoenvironmental change as derived from loess sediment properties: Examples of last glacial loess sites from the Carpathian Basin

NASA Astrophysics Data System (ADS)

Lehmkuhl, Frank; Zeeden, Christian; Bösken, Janina; Eckmeier, Eileen; Hambach, Ulrich; Hauck, Thomas; Klasen, Nicole; Markovic, Slobodan; Obreht, Igor; Schulte, Philipp; Sümegi, Pal; Chu, Wei; Timar-Gabor, Alida; Veres, Daniel

2015-04-01

The project B1 within the CRC 806 "Our way to Europe" focuses on the "Eastern Trajectory" of modern human migration from Africa into Europe. The Middle East, and SE Europe constitute the principal areas to be investigated. SE Europe has become a special research focus since two early Homo sapiens individuals have been found at Oase Cave in the southern Banat. The fossils lack any stratigraphic context; cultural and environmental circumstances of these findings have remained unclear. In the neighbourhood of Oase Cave, however, several early Upper Palaeolithic sites, embedded in loess sequences were known since the 1950's. Some sites were re-investigated by our research team. Conceptionally we are following the idea of upland-lowland interaction, which combines parameters as sedimentary transport, sediment distribution, and paleosol development in different altitudes, all influenced by paleoclimate in space and time. Furthermore, some detailed studies concerning site-formation processes and the quality of open-air sites (sedimentary development, paleoecology, multilayering, reworking, human impact on soils and sediments) are being conducted at selected localities. Recent investigations of the loess-paleosol sequences (LPS) in SE Europe provided important environmental information which differ from "classical" ecological approaches derived from other European loess provinces. New luminescence dating results provide a sensitive chronology of environmental changes recorded in the LPS from both upland and lowland positions, giving the potential to link these.
Does Mass Azithromycin Distribution Impact Child Growth and Nutrition in Niger? A Cluster-Randomized Trial

PubMed Central

Amza, Abdou; Yu, Sun N.; Kadri, Boubacar; Nassirou, Baido; Stoller, Nicole E.; Zhou, Zhaoxia; West, Sheila K.; Bailey, Robin L.; Gaynor, Bruce D.; Keenan, Jeremy D.; Porco, Travis C.; Lietman, Thomas M.

2014-01-01

Background Antibiotic use on animals demonstrates improved growth regardless of whether or not there is clinical evidence of infectious disease. Antibiotics used for trachoma control may play an unintended benefit of improving child growth. Methodology In this sub-study of a larger randomized controlled trial, we assess anthropometry of pre-school children in a community-randomized trial of mass oral azithromycin distributions for trachoma in Niger. We measured height, weight, and mid-upper arm circumference (MUAC) in 12 communities randomized to receive annual mass azithromycin treatment of everyone versus 12 communities randomized to receive biannual mass azithromycin treatments for children, 3 years after the initial mass treatment. We collected measurements in 1,034 children aged 6–60 months of age. Principal Findings We found no difference in the prevalence of wasting among children in the 12 annually treated communities that received three mass azithromycin distributions compared to the 12 biannually treated communities that received six mass azithromycin distributions (odds ratio = 0.88, 95% confidence interval = 0.53 to 1.49). Conclusions/Significance We were unable to demonstrate a statistically significant difference in stunting, underweight, and low MUAC of pre-school children in communities randomized to annual mass azithromycin treatment or biannual mass azithromycin treatment. The role of antibiotics on child growth and nutrition remains unclear, but larger studies and longitudinal trials may help determine any association. PMID:25210836
Wavelet decomposition based principal component analysis for face recognition using MATLAB

NASA Astrophysics Data System (ADS)

Sharma, Mahesh Kumar; Sharma, Shashikant; Leeprechanon, Nopbhorn; Ranjan, Aashish

2016-03-01

For the realization of face recognition systems in the static as well as in the real time frame, algorithms such as principal component analysis, independent component analysis, linear discriminate analysis, neural networks and genetic algorithms are used for decades. This paper discusses an approach which is a wavelet decomposition based principal component analysis for face recognition. Principal component analysis is chosen over other algorithms due to its relative simplicity, efficiency, and robustness features. The term face recognition stands for identifying a person from his facial gestures and having resemblance with factor analysis in some sense, i.e. extraction of the principal component of an image. Principal component analysis is subjected to some drawbacks, mainly the poor discriminatory power and the large computational load in finding eigenvectors, in particular. These drawbacks can be greatly reduced by combining both wavelet transform decomposition for feature extraction and principal component analysis for pattern representation and classification together, by analyzing the facial gestures into space and time domain, where, frequency and time are used interchangeably. From the experimental results, it is envisaged that this face recognition method has made a significant percentage improvement in recognition rate as well as having a better computational efficiency.
Hilar GABAergic Interneuron Activity Controls Spatial Learning and Memory Retrieval

PubMed Central

Andrews-Zwilling, Yaisa; Gillespie, Anna K.; Kravitz, Alexxai V.; Nelson, Alexandra B.; Devidze, Nino; Lo, Iris; Yoon, Seo Yeon; Bien-Ly, Nga; Ring, Karen; Zwilling, Daniel; Potter, Gregory B.; Rubenstein, John L. R.; Kreitzer, Anatol C.; Huang, Yadong

2012-01-01

Background Although extensive research has demonstrated the importance of excitatory granule neurons in the dentate gyrus of the hippocampus in normal learning and memory and in the pathogenesis of amnesia in Alzheimer's disease (AD), the role of hilar GABAergic inhibitory interneurons, which control the granule neuron activity, remains unclear. Methodology and Principal Findings We explored the function of hilar GABAergic interneurons in spatial learning and memory by inhibiting their activity through Cre-dependent viral expression of enhanced halorhodopsin (eNpHR3.0)—a light-driven chloride pump. Hilar GABAergic interneuron-specific expression of eNpHR3.0 was achieved by bilaterally injecting adeno-associated virus containing a double-floxed inverted open-reading frame encoding eNpHR3.0 into the hilus of the dentate gyrus of mice expressing Cre recombinase under the control of an enhancer specific for GABAergic interneurons. In vitro and in vivo illumination with a yellow laser elicited inhibition of hilar GABAergic interneurons and consequent activation of dentate granule neurons, without affecting pyramidal neurons in the CA3 and CA1 regions of the hippocampus. We found that optogenetic inhibition of hilar GABAergic interneuron activity impaired spatial learning and memory retrieval, without affecting memory retention, as determined in the Morris water maze test. Importantly, optogenetic inhibition of hilar GABAergic interneuron activity did not alter short-term working memory, motor coordination, or exploratory activity. Conclusions and Significance Our findings establish a critical role for hilar GABAergic interneuron activity in controlling spatial learning and memory retrieval and provide evidence for the potential contribution of GABAergic interneuron impairment to the pathogenesis of amnesia in AD. PMID:22792368
Cortactin as a Target for FAK in the Regulation of Focal Adhesion Dynamics

PubMed Central

Ghassemian, Majid; Schlaepfer, David D.

2012-01-01

Background Efficient cell movement requires the dynamic regulation of focal adhesion (FA) formation and turnover. FAs are integrin-associated sites of cell attachment and establish linkages to the cellular actin cytoskeleton. Cells without focal adhesion kinase (FAK), an integrin-activated tyrosine kinase, exhibit defects in FA turnover and cell motility. Cortactin is an actin binding adaptor protein that can influence FA dynamics. FAK and cortactin interact, but the cellular role of this complex remains unclear. Principal Findings Using FAK-null fibroblasts stably reconstituted with green fluorescent protein (GFP) tagged FAK constructs, we find that FAK activity and FAK C-terminal proline-rich region 2 (PRR2) and PRR3 are required for FA turnover and cell motility. Cortactin binds directly to FAK PRR2 and PRR3 sites via its SH3 domain and cortactin expression is important in promoting FA turnover and GFP-FAK release from FAs. FAK-cortactin binding is negatively-regulated by FAK activity and associated with cortactin tyrosine phosphorylation. FAK directly phosphorylates cortactin at Y421 and Y466 and over-expression of cortactin Y421, Y466, and Y482 mutated to phenylalanine (3YF) prevented FAK-enhanced FA turnover and cell motility. However, phospho-mimetic cortactin mutated to glutamic acid (3YE) did not affect FA dynamics and did not rescue FA turnover defects in cells with inhibited FAK activity or with PRR2-mutated FAK that does not bind cortactin. Conclusions Our results support a model whereby FAK-mediated FA remodeling may occur through the formation of a FAK-cortactin signaling complex. This involves a cycle of cortactin binding to FAK, cortactin tyrosine phosphorylation, and subsequent cortactin-FAK dissociation accompanied by FA turnover and cell movement. PMID:22952866
Insulin Resistance in Chileans of European and Indigenous Descent: Evidence for an Ethnicity x Environment Interaction

PubMed Central

Celis-Morales, Carlos A.; Perez-Bravo, Francisco; Ibañes, Luis; Sanzana, Ruth; Hormazabal, Edison; Ulloa, Natalia; Calvo, Carlos; Bailey, Mark E. S.; Gill, Jason M. R.

2011-01-01

Background Effects of urbanisation on diabetes risk appear to be greater in indigenous populations worldwide than in populations of European origin, but the reasons are unclear. This cross-sectional study aimed to determine whether the effects of environment (Rural vs. Urban), adiposity, fitness and lifestyle variables on insulin resistance differed between individuals of indigenous Mapuche origin compared to those of European origin in Chile. Methodology/Principal Findings 123 Rural Mapuche, 124 Urban Mapuche, 91 Rural European and 134 Urban European Chilean adults had blood taken for determination of HOMA-estimated insulin resistance (HOMAIR) and underwent assessment of physical activity/sedentary behaviour (using accelerometry), cardiorespiratory fitness, dietary intake and body composition. General linear models were used to determine interactions with ethnicity for key variables. There was a significant “ethnicity x environment” interaction for HOMAIR (Mean±SD; Rural Mapuche: 1.65±2.03, Urban Mapuche: 4.90±3.05, Rural European: 0.82±0.61, Urban European: 1.55±1.34, p (interaction) = 0.0003), such that the effect of urbanisation on HOMAIR was greater in Mapuches than Europeans. In addition, there were significant interactions (all p<0.004) with ethnicity for effects of adiposity, sedentary time and physical activity on HOMAIR, with greater effects seen in Mapuches compared to Europeans, an observation that persisted after adjustment for potential confounders. Conclusions/Significance Urbanisation, adiposity, physical activity and sedentary behaviour influence insulin resistance to a greater extent in Chilean Mapuches than Chileans of European descent. These findings have implications for the design and implementation of lifestyle strategies to reduce metabolic risk in different ethnic groups, and for understanding of the mechanisms underpinning human insulin resistance. PMID:21931814
Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes

PubMed Central

Laperchia, Claudia; Palomba, Maria; Seke Etet, Paul F.; Rodgers, Jean; Bradley, Barbara; Montague, Paul; Grassi-Zucconi, Gigliola; Bentivoglio, Marina

2016-01-01

Background The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications. Methodology Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM) periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses. Principal findings Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion. Conclusion These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging. PMID:28002454
Thymoquinone Induces Cell Death in Human Squamous Carcinoma Cells via Caspase Activation-Dependent Apoptosis and LC3-II Activation-Dependent Autophagy

PubMed Central

Yu, Cheng-Chia; Lai, Yi-Yeh; Chen, Pei-Ni

2014-01-01

Background Thymoquinone (TQ), an active component of Nigella sativa or black cumin, elicits cytotoxic effects on various cancer cell lines. However, the anti-cancer effects of TQ on head and neck squamous cell carcinoma (HNSCC) remain unclear. Methodology/Principal Findings In this study, TQ elicited a strong cytotoxic effect on SASVO3, a highly malignant HNSCC cell line. The mechanisms of this cytotoxic effect were concentration dependent. TQ also induced apoptotic cell death in SASVO3 cells as indicated by an increase in Bax expression and caspase-9 activation. Apoptosis was possibly caspase-9 dependent because the exposure of cells to a caspase-9 inhibitor partially prevented cell death. The exposed cells also showed increased levels of autophagic vacuoles and LC3-II proteins, which are specific autophagy markers. Cell viability assay results further revealed that bafilomycin-A1, an autophagy inhibitor, enhanced TQ cytotoxicity; by comparison, Annexin V and propidium-iodide staining assay results showed that this inhibitor did not promote apoptosis. TQ treatment also increased the accumulation of autophagosomes. Using a lentivirus-shRNA system for LC3 silencing, we found that cell viability was eradicated in autophagy-defective cells. An in vivo BALB/c nude mouse xenograft model further showed that TQ administered by oral gavage reduced tumor growth via induced autophagy and apoptosis. Conclusions These findings indicated that TQ induced cell death in oral cancer cells via two distinct anti-neoplastic activities that can induce apoptosis and autophagy. Therefore, TQ is a promising candidate in phytochemical-based, mechanistic, and pathway-targeted cancer prevention strategies. PMID:25000169
Can Oxygen Set Thermal Limits in an Insect and Drive Gigantism?

PubMed Central

Verberk, Wilco C. E. P.; Bilton, David T.

2011-01-01

Background Thermal limits may arise through a mismatch between oxygen supply and demand in a range of animal taxa. Whilst this oxygen limitation hypothesis is supported by data from a range of marine fish and invertebrates, its generality remains contentious. In particular, it is unclear whether oxygen limitation determines thermal extremes in tracheated arthropods, where oxygen limitation may be unlikely due to the efficiency and plasticity of tracheal systems in supplying oxygen directly to metabolically active tissues. Although terrestrial taxa with open tracheal systems may not be prone to oxygen limitation, species may be affected during other life-history stages, particularly if these rely on diffusion into closed tracheal systems. Furthermore, a central role for oxygen limitation in insects is envisaged within a parallel line of research focussing on insect gigantism in the late Palaeozoic. Methodology/Principal Findings Here we examine thermal maxima in the aquatic life stages of an insect at normoxia, hypoxia (14 kPa) and hyperoxia (36 kPa). We demonstrate that upper thermal limits do indeed respond to external oxygen supply in the aquatic life stages of the stonefly Dinocras cephalotes, suggesting that the critical thermal limits of such aquatic larvae are set by oxygen limitation. This could result from impeded oxygen delivery, or limited oxygen regulatory capacity, both of which have implications for our understanding of the limits to insect body size and how these are influenced by atmospheric oxygen levels. Conclusions/Significance These findings extend the generality of the hypothesis of oxygen limitation of thermal tolerance, suggest that oxygen constraints on body size may be stronger in aquatic environments, and that oxygen toxicity may have actively selected for gigantism in the aquatic stages of Carboniferous arthropods. PMID:21818347
Protein contact dermatitis: allergens, pathogenesis, and management.

PubMed

Levin, Cheryl; Warshaw, Erin

2008-01-01

Protein contact dermatitis is an allergic skin reaction induced principally by proteins of either animal or plant origin. The clinical presentation is that of a chronic dermatitis, and it is often difficult to differentiate between allergic contact dermatitis and other eczematous dermatoses. One distinguishing clinical feature is that acute flares of pruritus, urticaria, edema, or vesiculation are noted minutes after contact with the causative substances. Additionally, the patch-test result is typically negative, and the scratch- or prick-test result is positive. The pathogenesis of protein contact dermatitis is unclear but may involve a type I (immunoglobulin E [IgE], immediate) hypersensitivity reaction, type IV (cell-mediated delayed) hypersensitivity reaction, and/or a delayed reaction due to IgE-bearing Langerhans' cells. Management involves avoidance of the allergen.
Rapid HIV Testing in Dental Practices

PubMed Central

Abel, Stephen N.; Pereyra, Margaret; Liguori, Terri; Pollack, Harold A.; Metsch, Lisa R.

2012-01-01

Despite increasing discussion about the dental care setting as a logical, potentially fruitful venue for rapid HIV testing, dentists’ willingness to take on this task is unclear. Semistructured interviews with 40 private practice dentists revealed their principal concerns regarding offering patients HIV testing were false results, offending patients, viewing HIV testing as outside the scope of licensure, anticipating low patient acceptance of HIV testing in a dental setting, expecting inadequate reimbursement, and potential negative impact on the practice. Dentists were typically not concerned about transmission risks, staff opposition to testing, or making referrals for follow-up after a positive result. A larger cultural change may be required to engage dentists more actively in primary prevention and population-based HIV screening. PMID:22397342
Field studies in pesticide registration: questioning the answers.

PubMed

Montforts, Mark H M M; de Jong, Frank M W

2007-01-01

The principal conclusion of a workshop in October 2005 at RIVM (Bilthoven, The Netherlands) on the assessment of field studies with pesticides for authorization is that the lack of a definition of acceptability of effects is recognized as a problem by all stakeholders: Industry, risk assessors, and regulators. Because of this lack of definition in the legislation, it is unclear what critical effect values should be assessed in field studies. Despite the extensive documentation on field study performance, the decision making is not based on justifiable scientific opinions or publicly shared values but on technical limitations of the test design instead. In the workshop, research was identified that should result in a scientific basis for value judgments applied in decision making.
Merkel cells and neurons keep in touch

PubMed Central

Woo, Seung-Hyun; Lumpkin, Ellen A.; Patapoutian, Ardem

2014-01-01

The Merkel cell-neurite complex is a unique vertebrate touch receptor comprising two distinct cell types in the skin. Its presence in touch-sensitive skin areas was recognized more than a century ago, but the functions of each cell type in sensory transduction have been unclear. Three recent studies demonstrate that Merkel cells are mechanosensitive cells that function in touch transduction via Piezo2. One study concludes that Merkel cells rather than sensory neurons are principal sites of mechanotransduction, whereas the other two studies report that both Merkel cells and neurons encode mechanical inputs. Together, these studies settle a longstanding debate on whether Merkel cells are mechanosensory cells, and enable future investigations of how these skin cells communicate with neurons. PMID:25480024
Kawasaki Disease

PubMed Central

2006-01-01

Kawasaki disease is an acute febrile, systemic vasculitic syndrome of an unknown etiology that primarily occurs in children younger than five years of age. The principal presentations of Kawasaki disease include fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develops in 15% to 25% of untreated children with the disease, which may later lead to myocardial infarction, sudden death, or ischemic heart disease. Treatment with intravenous gamma globulin (IVIG) is effective, but the mode of action is still unclear. The development of a diagnostic test, a more specific therapy, and ultimately the prevention of this potentially fatal illness in children are all dependent upon the continued advances in determining the etiopathogenesis of this fascinating disorder. PMID:17191303

Attitude toward Visionary Leadership.

ERIC Educational Resources Information Center

Lesourd, Sandra J.; And Others

1992-01-01

Formulates descriptive research findings into a utilitarian tool for principal leadership development programs. An instrument measuring attitude toward a (visionary) leadership ideal was developed, administered, and analyzed. Previous research findings were summarized. Results showed that the instrument would help assess individual acceptance of…
Does Bipedality Predict the Group-Level Manual Laterality in Mammals?

PubMed Central

Giljov, Andrey; Karenina, Karina; Malashichev, Yegor

2012-01-01

Background Factors determining patterns of laterality manifestation in mammals remain unclear. In primates, the upright posture favours the expression of manual laterality across species, but may have little influence within a species. Whether the bipedalism acts the same in non-primate mammals is unknown. Our recent findings in bipedal and quadrupedal marsupials suggested that differences in laterality pattern, as well as emergence of manual specialization in evolution might depend on species-specific body posture. Here, we evaluated the hypothesis that the postural characteristics are the key variable shaping the manual laterality expression across mammalian species. Methodology/Principal Findings We studied forelimb preferences in a most bipedal marsupial, brush-tailed bettong, Bettongia penicillata in four different types of unimanual behavior. The significant left-forelimb preference at the group level was found in all behaviours studied. In unimanual feeding on non-living food, catching live prey and nest-material collecting, all or most subjects were lateralized, and among lateralized bettongs a significant majority displayed left-forelimb bias. Only in unimanual supporting of the body in the tripedal stance the distribution of lateralized and non-lateralized individuals did not differ from chance. Individual preferences were consistent across all types of behaviour. The direction or the strength of forelimb preferences were not affected by the animals’ sex. Conclusions/Significance Our findings support the hypothesis that the expression of manual laterality depends on the species-typical postural habit. The interspecies comparison illustrates that in marsupials the increase of bipedality corresponds with the increase of the degree of group-level forelimb preference in a species. Thus, bipedalism can predict pronounced manual laterality at both intra- and interspecific levels in mammals. We also conclude that quadrupedal position in biped species can slightly hinder the expression of manual laterality, but the evoked biped position in quadrupedal species does not necessarily lead to the enhanced manifestation of manual laterality. PMID:23251583
Lutzomyia umbratilis, the Main Vector of Leishmania guyanensis, Represents a Novel Species Complex?

PubMed Central

Scarpassa, Vera Margarete; Alencar, Ronildo Baiatone

2012-01-01

Background Lutzomyia umbratilis is an important Leishmania guyanensis vector in South America. Previous studies have suggested differences in the vector competence between L. umbratilis populations situated on opposite banks of the Amazonas and Negro Rivers in the central Amazonian Brazil region, likely indicating a species complex. However, few studies have been performed on these populations and the taxonomic status of L. umbratilis remains unclear. Methodology/Principal Findings Phylogeographic structure was estimated for six L. umbratilis samples from the central Amazonian region in Brazil by analyzing mtDNA using 1181 bp of the COI gene to assess whether the populations on opposite banks of these rivers consist of incipient or distinct species. The genetic diversity was fairly high and the results revealed two distinct clades ( = lineages) with 1% sequence divergence. Clade I consisted of four samples from the left bank of the Amazonas and Negro Rivers, whereas clade II comprised two samples from the right bank of Negro River. No haplotypes were shared between samples of two clades. Samples within clades exhibited low to moderate genetic differentiation (F ST = −0.0390–0.1841), whereas samples between clades exhibited very high differentiation (F ST = 0.7100–0.8497) and fixed differences. These lineages have diverged approximately 0.22 Mya in the middle Pleistocene. Demographic expansion was detected for the lineages I and II approximately 30,448 and 15,859 years ago, respectively, in the late Pleistocene. Conclusions/Significance The two genetic lineages may represent an advanced speciation stage suggestive of incipient or distinct species within L. umbratilis. These findings suggest that the Amazonas and Negro Rivers may be acting as effective barriers, thus preventing gene flow between populations on opposite sides. Such findings have important implications for epidemiological studies, especially those related to vector competence and anthropophily, and for vector control strategies. In addition, L. umbratilis represents an interesting example in speciation studies. PMID:22662146
Neuropathological findings in cattle with clinically suspect but histologically unconfirmed bovine spongiform encephalopathy (BSE).

PubMed

McGill, I S; Wells, G A

1993-04-01

Neuropathological observations were made in 200 clinically suspected cases of bovine spongiform encephalopathy (BSE) in which pathognomonic vacuolar changes were absent. Routine histological and immunocytochemical techniques were applied to formalin-fixed, paraffin-embedded sections of the central nervous system. Significant neuropathological findings were detected in 85 (42.5 per cent) cases. The most frequent lesion, detected in 46 (23 per cent) cases, was a focal white matter vacuolation principally affecting the substantia nigra, but its clinical significance was unclear. Listeriosis was diagnosed in 17 (8.5 per cent) cases. In three of seven cases of non-suppurative encephalitis, lesions suggested sporadic bovine encephalomyelitis, a disease not previously reported in the UK. Suppurative thromboembolic or granulomatous lesions accounted for other inflammatory changes. Neuroectodermal tumours were present in five cases (2.5 per cent); three were identical in form and considered to be atypical ependymoma. Cerebrocortical necrosis, oedema or both were detected in four cases. The remaining cases (4.5 per cent), comprised those in which the changes were minor and of doubtful significance. Incidental pathological findings included occasional degenerating or vacuolated neurones, which occurred in the red nucleus in 105 brains, in the habenular nucleus in 71 brains, and singly at other sites in 17 brains. In sections of 37 brains immunostained with antiserum to prion protein (PrP), no evidence of PrP accumulation was found, providing some evidence that the series did not contain bovine prion disease cases which, based on the histological diagnosis, had given a false negative result. It is suggested that, of 115 cases (57.5 per cent) which lacked significant histological lesions, some were suffering from metabolic disorders. The study identified diseases and lesions which feature in the differential diagnosis of BSE. Their more accurate diagnosis may become particularly important if, as predicted, the BSE epidemic declines.
Preparing and Supporting Principals for Effective Leadership: Early Findings from Stanford's School Leadership Study. School Leadership Study: Developing Successful Principals

ERIC Educational Resources Information Center

LaPointe, Michelle; Meyerson, Debra; Darling-Hammond, Linda

2006-01-01

The School Leadership Study was designed to contribute important data on how high quality pre- and in-service programs are structured, how they implement the effective strategies noted in the research literature, and the impact of program graduates in the schools they lead. The study examines whether program components triangulate with graduate…
The Drive to Strive: An Assistant Principal Reflects on a Career Built on Constant Learning

ERIC Educational Resources Information Center

Osabutey-Aguedje, Tameka

2015-01-01

At different stages of her career, the author has experienced, supported, and facilitated professional learning efforts. As an assistant principal, she finds that she has learned something of value at each stage. In this article, as the author reflects on her career, she realizes that it is important to learn and grow rather than just try to…
A Case Study of School Principals in the United States and Japan: Metaphors of Fire and Water.

ERIC Educational Resources Information Center

McGee, Glenn W.

In the United States in recent years there has been extensive concern about school reform and keen interest in Japanese business-management practices. This paper presents findings of a case study that examined the role and responsibilities of two middle school principals, one in Japan and one in the United States. The study is based on Krug's…
An Analysis of the Relationship between Principal Employment Interview Scores and the Achievement Scores of Students with Specific Learning Disabilities

ERIC Educational Resources Information Center

Ostmeyer, Susan S.

2012-01-01

The primary purpose of this study was to examine the relationship between five of ISSLC's 2008 leadership standards as measured by a standardized employment interview (ICIS Principal) and the achievement of students with specific learning disabilities in core areas of instruction. Findings did not support the rejection of the null hypothesis.…
High Stakes Principalship--Sleepless Nights, Heart Attacks and Sudden Death Accountabilities: Reading Media Representations of the United States Principal Shortage.

ERIC Educational Resources Information Center

Thomson, Pat; Blackmore, Jill; Sachs, Judyth; Tregenza, Karen

2003-01-01

Subjects a corpus of predominantly United States news articles to deconstructive narrative analysis and finds that the dominant media representation of principals' work is one of long hours, low salary, high stress, and sudden death from high stakes accountabilities. Notes that the media picture may perpetuate the problem, and that it is at odds…
Moments of inertia of relativistic magnetized stars

NASA Astrophysics Data System (ADS)

Konno, K.

2001-06-01

We consider principal moments of inertia of axisymmetric, magnetically deformed stars in the context of general relativity. The general expression for the moment of inertia with respect to the symmetric axis is obtained. The numerical estimates are derived for several polytropic stellar models. We find that the values of the principal moments of inertia are modified by a factor of 2 at most from Newtonian estimates.
Urban school leadership for elementary science education: Meeting the needs of English Language Learners

NASA Astrophysics Data System (ADS)

Alarcon, Maricela H.

Science education reform and state testing accountability call upon principals to become instructional leaders in science. Specifically, elementary school principals must take an active role in science instruction to effectively improve science education for all students including English Language Learners. As such, the research questioned posed in this study centered on How are elementary school principals addressing the academic needs of Latino Spanish-speaking English language learners within science education? This study employed a qualitative research design to identify the factors contributing to the exemplary performance in science, as measured by the Texas Assessment of Knowledge and Skills (TAKS), for English Language Learner students in three high poverty bilingual elementary schools based on a multiple case study. As part of the data collection process, interviews were conducted with three school principals, three science academic support teachers, and two 5th grade bilingual teachers. Additionally, observations were acquired through school principal shadowing. The findings revealed four attributes necessary for effective instructional leadership in science education. First, Positive School Culture was defined as the core that linked the other three instructional leadership attributes and thus increased their effectiveness. Second, Clear Goals and Expectations were set by making science a priority and ensuring that English language learners were transitioning from Spanish to English instruction by the fifth grade. Third, Critical Resourcing involved hiring a science academic support teacher, securing a science classroom on campus, and purchasing bilingual instructional materials. Fourth, principal led and supported Collaboration in which teachers met to discuss student performance based data in addition to curriculum and instruction. These research findings are vital because by implementing these best practices of elementary school principals, educators are positioned to lay the foundation for science needed for ELLs to continue their educational career with the tools needed to succeed in future science classes and in turn college, answering the call to effectively improve science within the educational system.
19 CFR 12.42 - Findings of Commissioner of Customs.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Findings of Commissioner of Customs. 12.42 Section 12.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Labor § 12.42 Findings of Commissioner of Customs. (a) If any port director or other principal Customs...
19 CFR 12.42 - Findings of Commissioner of Customs.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Findings of Commissioner of Customs. 12.42 Section 12.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Labor § 12.42 Findings of Commissioner of Customs. (a) If any port director or other principal Customs...
19 CFR 12.42 - Findings of Commissioner of Customs.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Findings of Commissioner of Customs. 12.42 Section 12.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Labor § 12.42 Findings of Commissioner of Customs. (a) If any port director or other principal Customs...
19 CFR 12.42 - Findings of Commissioner of Customs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Findings of Commissioner of Customs. 12.42 Section 12.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Labor § 12.42 Findings of Commissioner of Customs. (a) If any port director or other principal Customs...
19 CFR 12.42 - Findings of Commissioner of Customs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Findings of Commissioner of Customs. 12.42 Section 12.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Labor § 12.42 Findings of Commissioner of Customs. (a) If any port director or other principal Customs...
Leading Learning in Asia--Emerging Empirical Insights from Five Societies

ERIC Educational Resources Information Center

Hallinger, Philip; Walker, Allan

2017-01-01

Purpose: The purpose of this paper is to synthesize findings from studies of principal instructional leadership conducted in five East Asian societies. The authors first identify similarities and then differences in approaches to instructional leadership across the societies. Then the findings of the synthesis are compared with broad findings from…
Are schools and alcohol a good mix? A qualitative study of school principals' experiences of adults' alcohol use in Australian secondary schools

PubMed Central

Ward, Bernadette M; Buykx, Penny; Munro, Geoffrey; Wiggers, John

2016-01-01

Objective Parents, schools and the broader community influence children's socialisation to alcohol. In Australia, the UK and the USA, there have been media reports of adults consuming alcohol at family-focused school events such as fairs and graduations. The aim of this qualitative study was to describe school principals' experiences of adults' use of alcohol at school events, when children are present. Design/setting/participants A qualitative study was undertaken. Publicly available lists were used to invite 60 principals from government and Catholic secondary schools in Victoria, Australia. In-depth interviews were conducted and analysed thematically and reported using the Consolidated Criteria for Reporting Qualitative Research guidelines. Results 14 principals (5 female, 9 male) participated. Most (10) of the participating principals reported adults' use of alcohol at events when students were present. Regarding these events, most principals reported concerns regarding potential harms and responsibility for decision-making about alcohol availability in schools. Some (4) principals believed alcohol should not be present at such events and this was their practice. Half of the participating schools had recently made changes to reduce the availability or management of alcohol at school functions. Conclusions The findings confirm the common use of alcohol by adults at school events, the challenges this poses for school principals and suggests consideration needs to be given to identifying strategies for supporting schools and school principals in decision-making regarding the conduct of such events. PMID:27481620
Partitioning of functional gene expression data using principal points.

PubMed

Kim, Jaehee; Kim, Haseong

2017-10-12

DNA microarrays offer motivation and hope for the simultaneous study of variations in multiple genes. Gene expression is a temporal process that allows variations in expression levels with a characterized gene function over a period of time. Temporal gene expression curves can be treated as functional data since they are considered as independent realizations of a stochastic process. This process requires appropriate models to identify patterns of gene functions. The partitioning of the functional data can find homogeneous subgroups of entities for the massive genes within the inherent biological networks. Therefor it can be a useful technique for the analysis of time-course gene expression data. We propose a new self-consistent partitioning method of functional coefficients for individual expression profiles based on the orthonormal basis system. A principal points based functional partitioning method is proposed for time-course gene expression data. The method explores the relationship between genes using Legendre coefficients as principal points to extract the features of gene functions. Our proposed method provides high connectivity in connectedness after clustering for simulated data and finds a significant subsets of genes with the increased connectivity. Our approach has comparative advantages that fewer coefficients are used from the functional data and self-consistency of principal points for partitioning. As real data applications, we are able to find partitioned genes through the gene expressions found in budding yeast data and Escherichia coli data. The proposed method benefitted from the use of principal points, dimension reduction, and choice of orthogonal basis system as well as provides appropriately connected genes in the resulting subsets. We illustrate our method by applying with each set of cell-cycle-regulated time-course yeast genes and E. coli genes. The proposed method is able to identify highly connected genes and to explore the complex dynamics of biological systems in functional genomics.
An Investigation of the Relationship of ICT Training of Principals in ICT Integration in Management Public Secondary Schools: A Case of Nairobi County, Kenya

ERIC Educational Resources Information Center

Chepkonga, Susan

2015-01-01

The purpose of this study was to find out whether there exists a relationship between ICT training of principals and ICT integration in management of public secondary schools in Kenya. Cross-sectional survey design was used in Nairobi County where quantitative research strategy was applied for the collection of data using questionnaires. The…

Financial Audit. Federal Family Education Loan Program's Financial Statements for Fiscal Years 1993 and 1992. Report to the Congress and the Secretary of Education.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC.

This report presents findings of an audit of the Principal Statements of the Department of Education's (ED) Federal Family Education Loan Program (FFELP) and its internal controls and compliance with laws and regulations for the fiscal years ending September 30, 1993, and September 30, 1992. The audit investigated whether the Principal Statements…
Cognitive Complexity and Expertise: Relationships between External and Internal Measures of Cognitive Complexity and Abstraction, and Responses to a Case Problem.

ERIC Educational Resources Information Center

Allison, Derek J.; Morfitt, Grace; Demaerschalk, Dawn

On-the-job experience is commonly regarded as the prime prerequisite for proficiency. This paper presents findings of a study that compared the ways in which a group of practicing elementary principals (n=31) and aspiring principals (n=25) thought their way through a case study. The study was conducted as part of the Cognitive Approaches to School…
Chock Full of Data: How School Districts Are Building Leader Tracking Systems to Support Principal Pipelines. Stories from the Field

ERIC Educational Resources Information Center

Gill, Jennifer

2016-01-01

At one time, finding an assistant principal for a public school in Denver entailed a search through "a gajillion résumés," in the words of one local school district administrator. Even then, some ideal candidates likely fell through the cracks. Those days are over, owing to the development by Denver Public Schools of a "leader…
Investigating elementary principals' science beliefs and knowledge and its relationship to students' science outcomes

NASA Astrophysics Data System (ADS)

Khan, Uzma Zafar

The aim of this quantitative study was to investigate elementary principals' beliefs about reformed science teaching and learning, science subject matter knowledge, and how these factors relate to fourth grade students' superior science outcomes. Online survey methodology was used for data collection and included a demographic questionnaire and two survey instruments: the K-4 Physical Science Misconceptions Oriented Science Assessment Resources for Teachers (MOSART) and the Beliefs About Reformed Science Teaching and Learning (BARSTL). Hierarchical multiple regression analysis was used to assess the separate and collective contributions of background variables such as principals' personal and school characteristics, principals' science teaching and learning beliefs, and principals' science knowledge on students' superior science outcomes. Mediation analysis was also used to explore whether principals' science knowledge mediated the relationship between their beliefs about science teaching and learning and students' science outcomes. Findings indicated that principals' science beliefs and knowledge do not contribute to predicting students' superior science scores. Fifty-two percent of the variance in percentage of students with superior science scores was explained by school characteristics with free or reduced price lunch and school type as the only significant individual predictors. Furthermore, principals' science knowledge did not mediate the relationship between their science beliefs and students' science outcomes. There was no statistically significant variation among the variables. The data failed to support the proposed mediation model of the study. Implications for future research are discussed.
Shortcuts in complex engineering systems: a principal-agent approach to risk management.

PubMed

Garber, Russ; Paté-Cornell, Elisabeth

2012-05-01

In this article, we examine the effects of shortcuts in the development of engineered systems through a principal-agent model. We find that occurrences of illicit shortcuts are closely related to the incentive structure and to the level of effort that the agent is willing to expend from the beginning of the project to remain on schedule. Using a probabilistic risk analysis to determine the risks of system failure from these shortcuts, we show how a principal can choose optimal settings (payments, penalties, and inspections) that can deter an agent from cutting corners and maximize the principal's value through increased agent effort. We analyze the problem for an agent with limited liability. We consider first the case where he is risk neutral; we then include the case where he is risk averse. © 2011 Society for Risk Analysis.
THrombolysis for Acute Wake-up and unclear-onset Strokes with alteplase at 0·6 mg/kg (THAWS) Trial

PubMed Central

Koga, Masatoshi; Toyoda, Kazunori; Kimura, Kazumi; Yamamoto, Haruko; Sasaki, Makoto; Hamasaki, Toshimitsu; Kitazono, Takanari; Aoki, Junya; Seki, Kenta; Homma, Kazunari; Sato, Shoichiro; Minematsu, Kazuo

2014-01-01

Rationale Because of lack of information regarding timing of stroke, patients who suffer stroke during sleep are generally ineligible for intravenous thrombolysis, although many of these patients could potentially recover with this treatment. Magnetic resonance image findings with positive diffusion-weighted imaging and no marked parenchymal hyperintensity on fluid-attenuated inversion recovery (negative pattern) can identify acute ischemic stroke patients within 4·5 h from symptom onset. Aims The THrombolysis for Acute Wake-up and unclear-onset Strokes with alteplase at 0·6 mg/kg trial aims to determine the efficacy and safety of intravenous thrombolysis with alteplase at 0·6 mg/kg body weight, the approved dose for Japanese stroke patients, using magnetic resonance image-based selection in ischemic stroke patients with unclear time of symptom onset, and compare findings with standard treatment. Design This is an investigator-initiated, multicenter, prospective, randomized, open-treatment, blinded-end-point clinical trial. The design is similar to the Efficacy and Safety of MRI-based Thrombolysis in Wake-up Stroke trial. Patients with unclear-onset time of stroke symptoms beyond 4·5 h and within 12 h after the time of the last-known-well period and within 4·5 h after symptom recognition, who showed a negative fluid-attenuated inversion recovery pattern, are randomized to either intravenous thrombolysis or standard treatment. Study outcomes The primary efficacy end-point is modified Rankin Scale 0–1 at 90 days. The safety outcome measures are symptomatic intracranial hemorrhage at 22–36 h, and major bleeding and mortality at 90 days. Discussion This trial may help determine if low-dose alteplase at 0·6 mg/kg should be recommended as a routine clinical strategy for ischemic stroke patients with unclear-onset time. PMID:25088843
The Long-Term Effects of Organophosphates Poisoning as a Risk Factor of CVDs: A Nationwide Population-Based Cohort Study

PubMed Central

Lin, Cheng-Li; Chang, Shih-Yu; Sung, Fung-Chang; Tai, Sally C. W.

2015-01-01

Background Organophosphorus pesticides are widely used throughout the world. Because of their ease of availability, organophosphorus compounds are commonly used for self-poisoning in developing countries. The acute effects of exposure to organophosphorus pesticides are well known, but the chronic effects are unclear. Recent studies suggest that abnormalities of the central and peripheral nervous systems persisted for up to 5 years after acute poisoning due to a single large dose of organophosphates (OPs). However, the long-term effects on cardiovascular diseases are poorly understood. Methodology/Principal Findings An OPs-exposed cohort (N = 7,561) and an age- and gender-matched control cohort (N = 30,244), both identified from the National Health Insurance Research Database, were compared. We utilized the multivariable Cox proportional model to estimate the risks of developing arrhythmia, coronary artery disease (CAD) and congestive heart failure (CHF). The patients with acute poisoning from OPs had higher incidence rates of arrhythmia (5.89 vs. 3.61 per 1,000 person-years), CAD (9.10 vs. 6.88 per 1,000 person-years), and CHF (3.89 vs. 2.98 per 1,000 person-years) compared with that of the non-OPs poisoning cohort, with a crude subhazard ratio (SHR) of 1.40, 1.13, and 1.12, respectively. Additionally, a significantly higher risk of arrhythmia was observed in the OPs poisoning cohort (adjusted SHR = 1.25) compared with the non-OPs poisoning cohort, particularly in male patients (adjusted SHR = 1.33) and those under 49 years of age (adjusted SHR = 3.16). After accounting for the competing risks of death, there was a higher risk of arrhythmia and CAD during a three year follow-up period (adjusted SHR = 1.50 for arrhythmia; adjusted SHR = 1.10 for CAD). We also found an adjusted SHR of 1.36 associated with developing CHF after 6 years of follow-up for OPs poisoning cohort. Conclusions Acute OPs poisoning may continuously impact human health through mechanisms that are unclear. Any supportive measurements that could contribute to a reduction in the risk of heart disease may be beneficial in cases of OPs poisoning survivors. PMID:26339906
Community-Centered Responses to Ebola in Urban Liberia: The View from Below

PubMed Central

Abramowitz, Sharon Alane; McLean, Kristen E.; McKune, Sarah Lindley; Bardosh, Kevin Louis; Fallah, Mosoka; Monger, Josephine; Tehoungue, Kodjo; Omidian, Patricia A.

2015-01-01

Background The West African Ebola epidemic has demonstrated that the existing range of medical and epidemiological responses to emerging disease outbreaks is insufficient, especially in post-conflict contexts with exceedingly poor healthcare infrastructures. In this context, community-based responses have proven vital for containing Ebola virus disease (EVD) and shifting the epidemic curve. Despite a surge in interest in local innovations that effectively contained the epidemic, the mechanisms for community-based response remain unclear. This study provides baseline information on community-based epidemic control priorities and identifies innovative local strategies for containing EVD in Liberia. Methodology/Principal Findings This study was conducted in September 2014 in 15 communities in Monrovia and Montserrado County, Liberia – one of the epicenters of the Ebola outbreak. Findings from 15 focus group discussions with 386 community leaders identified strategies being undertaken and recommendations for what a community-based response to Ebola should look like under then-existing conditions. Data were collected on the following topics: prevention, surveillance, care-giving, community-based treatment and support, networks and hotlines, response teams, Ebola treatment units (ETUs) and hospitals, the management of corpses, quarantine and isolation, orphans, memorialization, and the need for community-based training and education. Findings have been presented as community-based strategies and recommendations for (1) prevention, (2) treatment and response, and (3) community sequelae and recovery. Several models for community-based management of the current Ebola outbreak were proposed. Additional findings indicate positive attitudes towards early Ebola survivors, and the need for community-based psychosocial support. Conclusions/Significance Local communities’ strategies and recommendations give insight into how urban Liberian communities contained the EVD outbreak while navigating the systemic failures of the initial state and international response. Communities in urban Liberia adapted to the epidemic using multiple coping strategies. In the absence of health, infrastructural and material supports, local people engaged in self-reliance in order to contain the epidemic at the micro-social level. These innovations were regarded as necessary, but as less desirable than a well-supported health-systems based response; and were seen as involving considerable individual, social, and public health costs, including heightened vulnerability to infection. PMID:25856072
Finding and Fixing Mistakes: Do Checklists Work for Clinicians with Different Levels of Experience?

ERIC Educational Resources Information Center

Sibbald, Matthew; De Bruin, Anique B. H.; van Merrienboer, Jeroen J. G.

2014-01-01

Checklists that focus attention on key variables might allow clinicians to find and fix their mistakes. However, whether this approach can be applied to clinicians of varying degrees of expertise is unclear. Novice and expert clinicians vary in their predominant reasoning processes and in the types of errors they commit. We studied 44 clinicians…
76 FR 11319 - Truth in Lending

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

... Congress enacted the Truth in Lending Act (TILA) based on findings that economic stability would be... Final Rule Congress enacted TILA based on findings that economic stability would be enhanced and... Economic Recovery Act of 2008 (HERA), also provides that its principal obligation limitations are subject...
The life-cycle of Emiliania huxleyi: A brief review and a study of relative ploidy levels analysed by flow cytometry

NASA Astrophysics Data System (ADS)

Green, J. C.; Course, P. A.; Tarran, G. A.

1996-10-01

Emiliania huxleyi exists in several principal forms including the familiar coccolith-bearing C-cell, non-motile naked N-cells, and scale-bearing swarmers (S-cells), but the relationships between these cells are unclear. Flow cytometric analyses have been undertaken on whole cells using fluorochrome staining of the DNA in order to determine the relative DNA content and the relative GC content of the S- and C-cells of selected clones. Results showed that the DNA complement of the S-cells was half that of the C-cells and the two cell types are, therefore, haploid and diploid relative to each other. The S-cells may, therefore, represent a gametic stage, though processes such as sexual fusion and meiosis have not been observed.
Estimation of species extinction: what are the consequences when total species number is unknown?

PubMed

Chen, Youhua

2014-12-01

The species-area relationship (SAR) is known to overestimate species extinction but the underlying mechanisms remain unclear to a great extent. Here, I show that when total species number in an area is unknown, the SAR model exaggerates the estimation of species extinction. It is proposed that to accurately estimate species extinction caused by habitat destruction, one of the principal prerequisites is to accurately total the species numbers presented in the whole study area. One can better evaluate and compare alternative theoretical SAR models on the accurate estimation of species loss only when the exact total species number for the whole area is clear. This presents an opportunity for ecologists to simulate more research on accurately estimating Whittaker's gamma diversity for the purpose of better predicting species loss.
Universal Non-Debye Scaling in the Density of States of Amorphous Solids.

PubMed

Charbonneau, Patrick; Corwin, Eric I; Parisi, Giorgio; Poncet, Alexis; Zamponi, Francesco

2016-07-22

At the jamming transition, amorphous packings are known to display anomalous vibrational modes with a density of states (DOS) that remains constant at low frequency. The scaling of the DOS at higher packing fractions remains, however, unclear. One might expect to find a simple Debye scaling, but recent results from effective medium theory and the exact solution of mean-field models both predict an anomalous, non-Debye scaling. Being mean-field in nature, however, these solutions are only strictly valid in the limit of infinite spatial dimension, and it is unclear what value they have for finite-dimensional systems. Here, we study packings of soft spheres in dimensions 3 through 7 and find, away from jamming, a universal non-Debye scaling of the DOS that is consistent with the mean-field predictions. We also consider how the soft mode participation ratio evolves as dimension increases.
A systematic review exploring therapist competence, adherence, and therapy outcomes in individual CBT for children and young people.

PubMed

Rapley, Hannah A; Loades, Maria E

2018-04-22

Whilst the evidence base for cognitive behavioural therapy (CBT) with children and young people is growing, the mechanisms through which these beneficial effects occur are still unclear. This systematic review seeks to appraise the relationship between therapeutic outcomes in CBT and therapist adherence and competence, within the child and adolescent literature. A systematic review was carried out, with five studies identified as meeting the inclusion criteria. The literature is currently small and inconclusive. Amongst the studies reviewed, there were inconsistent findings, with minimal-to-no effect sizes found between adherence, competence, and outcomes. The current paucity of research in this area means that conclusions are currently limited. The role and impact of adherence and competence on therapeutic outcomes remains unclear within individual CBT in a child population. This is comparable with the current adult literature, where findings also remain inconclusive. Further research avenues are discussed.
Principal Component and Linkage Analysis of Cardiovascular Risk Traits in the Norfolk Isolate

PubMed Central

Cox, Hannah C.; Bellis, Claire; Lea, Rod A.; Quinlan, Sharon; Hughes, Roger; Dyer, Thomas; Charlesworth, Jac; Blangero, John; Griffiths, Lyn R.

2009-01-01

Objective(s) An individual's risk of developing cardiovascular disease (CVD) is influenced by genetic factors. This study focussed on mapping genetic loci for CVD-risk traits in a unique population isolate derived from Norfolk Island. Methods This investigation focussed on 377 individuals descended from the population founders. Principal component analysis was used to extract orthogonal components from 11 cardiovascular risk traits. Multipoint variance component methods were used to assess genome-wide linkage using SOLAR to the derived factors. A total of 285 of the 377 related individuals were informative for linkage analysis. Results A total of 4 principal components accounting for 83% of the total variance were derived. Principal component 1 was loaded with body size indicators; principal component 2 with body size, cholesterol and triglyceride levels; principal component 3 with the blood pressures; and principal component 4 with LDL-cholesterol and total cholesterol levels. Suggestive evidence of linkage for principal component 2 (h2 = 0.35) was observed on chromosome 5q35 (LOD = 1.85; p = 0.0008). While peak regions on chromosome 10p11.2 (LOD = 1.27; p = 0.005) and 12q13 (LOD = 1.63; p = 0.003) were observed to segregate with principal components 1 (h2 = 0.33) and 4 (h2 = 0.42), respectively. Conclusion(s): This study investigated a number of CVD risk traits in a unique isolated population. Findings support the clustering of CVD risk traits and provide interesting evidence of a region on chromosome 5q35 segregating with weight, waist circumference, HDL-c and total triglyceride levels. PMID:19339786
Stability of the matrix model in operator interpretation

NASA Astrophysics Data System (ADS)

Sakai, Katsuta

2017-12-01

The IIB matrix model is one of the candidates for nonperturbative formulation of string theory, and it is believed that the model contains gravitational degrees of freedom in some manner. In some preceding works, it was proposed that the matrix model describes the curved space where the matrices represent differential operators that are defined on a principal bundle. In this paper, we study the dynamics of the model in this interpretation, and point out the necessity of the principal bundle from the viewpoint of the stability and diffeomorphism invariance. We also compute the one-loop correction which yields a mass term for each field due to the principal bundle. We find that the stability is not violated.
Efficient Coding and Statistically Optimal Weighting of Covariance among Acoustic Attributes in Novel Sounds

PubMed Central

Stilp, Christian E.; Kluender, Keith R.

2012-01-01

To the extent that sensorineural systems are efficient, redundancy should be extracted to optimize transmission of information, but perceptual evidence for this has been limited. Stilp and colleagues recently reported efficient coding of robust correlation (r = .97) among complex acoustic attributes (attack/decay, spectral shape) in novel sounds. Discrimination of sounds orthogonal to the correlation was initially inferior but later comparable to that of sounds obeying the correlation. These effects were attenuated for less-correlated stimuli (r = .54) for reasons that are unclear. Here, statistical properties of correlation among acoustic attributes essential for perceptual organization are investigated. Overall, simple strength of the principal correlation is inadequate to predict listener performance. Initial superiority of discrimination for statistically consistent sound pairs was relatively insensitive to decreased physical acoustic/psychoacoustic range of evidence supporting the correlation, and to more frequent presentations of the same orthogonal test pairs. However, increased range supporting an orthogonal dimension has substantial effects upon perceptual organization. Connectionist simulations and Eigenvalues from closed-form calculations of principal components analysis (PCA) reveal that perceptual organization is near-optimally weighted to shared versus unshared covariance in experienced sound distributions. Implications of reduced perceptual dimensionality for speech perception and plausible neural substrates are discussed. PMID:22292057
Cenesthopathy and Subjective Cognitive Complaints: An Exploratory Study in Schizophrenia.

PubMed

Jimeno, Natalia; Vargas, Martin L

2018-01-01

Cenesthopathy is mainly associated with schizophrenia; however, its neurobiological basis is nowadays unclear. The general objective was to explore clinical correlates of cenesthopathy and subjective cognitive complaints in schizophrenia. Participants (n = 30) meeting DSM-IV criteria for psychotic disorder were recruited from a psychiatry unit and assessed with: Association for Methodology and Documentation in Psychiatry (AMDP) system, Positive and Negative Syndrome Scale, Frankfurt Complaint Questionnaire (FCQ), and the Bonn Scale for the Assessment of Basic Symptoms (BSABS). For quantitative variables, means and Spearman correlation coefficients were calculated. Linear regression following backward method and principal component analysis with varimax rotation were used. 83.3% of subjects (73.3% male, mean age, 31.5 years) presented any type of cenesthopathy; all types of cenesthetic basic symptoms were found. Cenesthetic basic symptoms significantly correlated with the AMDP category "fear and anancasm," FCQ total score, and BSABS cognitive thought disturbances. In the regression analysis only 1 predictor, cognitive thought disturbances, entered the model. In the principal component analysis, a main component which accounted for 22.69% of the variance was found. Cenesthopathy, as assessed with the Bonn Scale (BSABS), is mainly associated with cog-nitive abnormalities including disturbances of thought initiative and mental intentionality, of receptive speech, and subjective retardation or pressure of thoughts. © 2018 S. Karger AG, Basel.
Reduced Anthocyanins in Petioles codes for a GST anthocyanin transporter that is essential for the foliage and fruit coloration in strawberry.

PubMed

Luo, Huifeng; Dai, Cheng; Li, Yongping; Feng, Jia; Liu, Zhongchi; Kang, Chunying

2018-04-27

The red color of the foliage and fruit in strawberry comes from anthocyanins stored in the vacuole; however, how this anthocyanin accumulation is regulated remains unclear. A reduced anthocyanin in petioles (rap) mutant was identified in an N-ethyl-N-nitrosourea (ENU) mutagenized population of YW5AF7, a white-fruited variety of the wild strawberry Fragaria vesca. The causative mutation was identified to be a premature stop codon in a glutathione S-transferase (GST) gene. In addition to the foliage coloration, RAP also mediates fruit pigmentation and acts downstream of the fruit-specific transcription factor FvMYB10. Among all eight GST genes in the same subfamily, RAP is most abundantly expressed in the ripening fruit. Expression analysis and transient expression assays demonstrated that RAP is the principal transporter of anthocyanins among the paralogs. Moreover, domain-swap experiments showed that both the N- and C-terminals of RAP are essential for the binding capability of anthocyanins. In addition, transient knock-down of RAP resulted in reduced fruit coloration in cultivated strawberry. Collectively, our results demonstrate that RAP encodes the principal GST transporter of anthocyanins in the strawberry foliage and fruit, and it could be modified to alter the fruit color in strawberry.
Structure-Activity Relationship in TLR4 Mutations: Atomistic Molecular Dynamics Simulations and Residue Interaction Network Analysis

NASA Astrophysics Data System (ADS)

Anwar, Muhammad Ayaz; Choi, Sangdun

2017-03-01

Toll-like receptor 4 (TLR4), a vital innate immune receptor present on cell surfaces, initiates a signaling cascade during danger and bacterial intrusion. TLR4 needs to form a stable hexamer complex, which is necessary to dimerize the cytoplasmic domain. However, D299G and T399I polymorphism may abrogate the stability of the complex, leading to compromised TLR4 signaling. Crystallography provides valuable insights into the structural aspects of the TLR4 ectodomain; however, the dynamic behavior of polymorphic TLR4 is still unclear. Here, we employed molecular dynamics simulations (MDS), as well as principal component and residue network analyses, to decipher the structural aspects and signaling propagation associated with mutations in TLR4. The mutated complexes were less cohesive, displayed local and global variation in the secondary structure, and anomalous decay in rotational correlation function. Principal component analysis indicated that the mutated complexes also exhibited distinct low-frequency motions, which may be correlated to the differential behaviors of these TLR4 variants. Moreover, residue interaction networks (RIN) revealed that the mutated TLR4/myeloid differentiation factor (MD) 2 complex may perpetuate abnormal signaling pathways. Cumulatively, the MDS and RIN analyses elucidated the mutant-specific conformational alterations, which may help in deciphering the mechanism of loss-of-function mutations.

Comparing the Ideal Dispositions of Administrative Internship Candidates

ERIC Educational Resources Information Center

Brown, Sidney L.

2015-01-01

This research will examine the dispositions of Instructional Leader Residents/interns (ILR/I's) at a State Department of Education (SDE) mandated redesigned masters principal preparation program at a Predominantly White Institution (PWI). Once the dispositions' findings were tabulated they were compared with the dispositions findings of…
The Role of School Principals in Shaping Children's Values.

PubMed

Berson, Yair; Oreg, Shaul

2016-12-01

Instilling values in children is among the cornerstones of every society. There is wide agreement that beyond academic teaching, schools play an important role in shaping schoolchildren's character, imparting in them values such as curiosity, achievement, benevolence, and citizenship. Despite the importance of this topic, we know very little about whether and how schools affect children's values. In this large-scale longitudinal study, we examined school principals' roles in the development of children's values. We hypothesized that relationships exist between principals' values and changes in children's values through the mediating effect of the school climate. To test our predictions, we collected data from 252 school principals, 3,658 teachers, and 49,401 schoolchildren. A multilevel structural-equation-modeling analysis yielded overall support for our hypotheses. These findings contribute to understanding the development of children's values and the far-reaching impact of leaders' values. They also demonstrate effects of schools on children beyond those on academic achievement.
Application of principal component analysis (PCA) as a sensory assessment tool for fermented food products.

PubMed

Ghosh, Debasree; Chattopadhyay, Parimal

2012-06-01

The objective of the work was to use the method of quantitative descriptive analysis (QDA) to describe the sensory attributes of the fermented food products prepared with the incorporation of lactic cultures. Panellists were selected and trained to evaluate various attributes specially color and appearance, body texture, flavor, overall acceptability and acidity of the fermented food products like cow milk curd and soymilk curd, idli, sauerkraut and probiotic ice cream. Principal component analysis (PCA) identified the six significant principal components that accounted for more than 90% of the variance in the sensory attribute data. Overall product quality was modelled as a function of principal components using multiple least squares regression (R (2) = 0.8). The result from PCA was statistically analyzed by analysis of variance (ANOVA). These findings demonstrate the utility of quantitative descriptive analysis for identifying and measuring the fermented food product attributes that are important for consumer acceptability.
Active integration of glutamatergic input to the inferior olive generates bidirectional postsynaptic potentials

PubMed Central

Garden, Derek L. F.; Rinaldi, Arianna

2016-01-01

Key points We establish experimental preparations for optogenetic investigation of glutamatergic input to the inferior olive.Neurones in the principal olivary nucleus receive monosynaptic extra‐somatic glutamatergic input from the neocortex.Glutamatergic inputs to neurones in the inferior olive generate bidirectional postsynaptic potentials (PSPs), with a fast excitatory component followed by a slower inhibitory component.Small conductance calcium‐activated potassium (SK) channels are required for the slow inhibitory component of glutamatergic PSPs and oppose temporal summation of inputs at intervals ≤ 20 ms.Active integration of synaptic input within the inferior olive may play a central role in control of olivo‐cerebellar climbing fibre signals. Abstract The inferior olive plays a critical role in motor coordination and learning by integrating diverse afferent signals to generate climbing fibre inputs to the cerebellar cortex. While it is well established that climbing fibre signals are important for motor coordination, the mechanisms by which neurones in the inferior olive integrate synaptic inputs and the roles of particular ion channels are unclear. Here, we test the hypothesis that neurones in the inferior olive actively integrate glutamatergic synaptic inputs. We demonstrate that optogenetically activated long‐range synaptic inputs to the inferior olive, including projections from the motor cortex, generate rapid excitatory potentials followed by slower inhibitory potentials. Synaptic projections from the motor cortex preferentially target the principal olivary nucleus. We show that inhibitory and excitatory components of the bidirectional synaptic potentials are dependent upon AMPA (GluA) receptors, are GABAA independent, and originate from the same presynaptic axons. Consistent with models that predict active integration of synaptic inputs by inferior olive neurones, we find that the inhibitory component is reduced by blocking large conductance calcium‐activated potassium channels with iberiotoxin, and is abolished by blocking small conductance calcium‐activated potassium channels with apamin. Summation of excitatory components of synaptic responses to inputs at intervals ≤ 20 ms is increased by apamin, suggesting a role for the inhibitory component of glutamatergic responses in temporal integration. Our results indicate that neurones in the inferior olive implement novel rules for synaptic integration and suggest new principles for the contribution of inferior olive neurones to coordinated motor behaviours. PMID:27767209
5 CFR 340.101 - Principal statutory requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Findings and Purpose Sec. 2. (a) The Congress finds that— (1) many individuals in our society possess great... be equal to the percentage which bears the same ratio to the percentage determined under this... scheduled workweek bears to the average number of hours in the regularly scheduled workweek of an employee...
Teaching the Pursuit of Assumptions

ERIC Educational Resources Information Center

Gardner, Peter; Johnson, Stephen

2015-01-01

Within the school of thought known as Critical Thinking, identifying or finding missing assumptions is viewed as one of the principal thinking skills. Within the new subject in schools and colleges, usually called Critical Thinking, the skill of finding missing assumptions is similarly prominent, as it is in that subject's public examinations. In…
Combined Activity of DCL2 and DCL3 Is Crucial in the Defense against Potato Spindle Tuber Viroid

PubMed Central

Katsarou, Konstantina; Mavrothalassiti, Eleni; Dermauw, Wannes; Van Leeuwen, Thomas; Kalantidis, Kriton

2016-01-01

Viroids are self replicating non-coding RNAs capable of infecting a wide range of plant hosts. They do not encode any proteins, thus the mechanism by which they escape plant defenses remains unclear. RNAi silencing is a major defense mechanism against virus infections, with the four DCL proteins being principal components of the pathway. We have used Nicotiana benthamiana as a model to study Potato spindle tuber viroid infection. This viroid is a member of the Pospiviroidae family and replicates in the nucleus via an asymmetric rolling circle mechanism. We have created knock-down plants for all four DCL genes and their combinations. Previously, we showed that DCL4 has a positive effect on PSTVd infectivity since viroid levels drop when DCL4 is suppressed. Here, we show that PSTVd levels remain decreased throughout infection in DCL4 knockdown plants, and that simultaneous knockdown of DCL1, DCL2 or DCL3 together with DCL4 cannot reverse this effect. Through infection of plants suppressed for multiple DCLs we further show that a combined suppression of DCL2 and DCL3 has a major effect in succumbing plant antiviral defense. Based on our results, we further suggest that Pospoviroids may have evolved to be primarily processed by DCL4 as it seems to be a DCL protein with less detrimental effects on viroid infectivity. These findings pave the way to delineate the complexity of the relationship between viroids and plant RNA silencing response. PMID:27732664
Family and school socioeconomic disadvantage: interactive influences on adolescent dating violence victimization.

PubMed

Spriggs, Aubrey L; Halpern, Carolyn Tucker; Herring, Amy H; Schoenbach, Victor J

2009-06-01

Although low socioeconomic status has been positively associated with adult partner violence, its relationship to adolescent dating violence remains unclear. Further, few studies have examined the relationship between contextual disadvantage and adolescent dating violence, or the interactive influences of family and contextual disadvantage. Guided by social disorganization theory, relative deprivation theory, and gendered resource theory, we analyzed data from the U.S. National Longitudinal Study of Adolescent Health (1994-1996) to explore how family and school disadvantage relate to dating violence victimization. Psychological and minor physical victimization were self-reported by adolescents in up to six heterosexual romantic or sexual relationships. Family and school disadvantage were based on a principal component analysis of socioeconomic indicators reported by adolescents and parents. In weighted multilevel random effects models, between-school variability in dating violence victimization was proportionately small but substantive: 10% for male victimization and 5% for female victimization. In bivariate analyses, family disadvantage was positively related to victimization for both males and females; however, school disadvantage was only related to males' physical victimization. In models adjusted for race/ethnicity, relative age within the school, and mean school age, neither family nor school disadvantage remained related to males' victimization. For females, family disadvantage remained significantly positively associated with victimization, but was modified by school disadvantage: family disadvantage was more strongly associated with dating violence victimization in more advantaged schools. Findings support gendered resource theory, and suggest that status differentials between females and their school context may increase their vulnerability to dating violence victimization.
Angry facial expressions bias gender categorization in children and adults: behavioral and computational evidence

PubMed Central

Bayet, Laurie; Pascalis, Olivier; Quinn, Paul C.; Lee, Kang; Gentaz, Édouard; Tanaka, James W.

2015-01-01

Angry faces are perceived as more masculine by adults. However, the developmental course and underlying mechanism (bottom-up stimulus driven or top-down belief driven) associated with the angry-male bias remain unclear. Here we report that anger biases face gender categorization toward “male” responding in children as young as 5–6 years. The bias is observed for both own- and other-race faces, and is remarkably unchanged across development (into adulthood) as revealed by signal detection analyses (Experiments 1–2). The developmental course of the angry-male bias, along with its extension to other-race faces, combine to suggest that it is not rooted in extensive experience, e.g., observing males engaging in aggressive acts during the school years. Based on several computational simulations of gender categorization (Experiment 3), we further conclude that (1) the angry-male bias results, at least partially, from a strategy of attending to facial features or their second-order relations when categorizing face gender, and (2) any single choice of computational representation (e.g., Principal Component Analysis) is insufficient to assess resemblances between face categories, as different representations of the very same faces suggest different bases for the angry-male bias. Our findings are thus consistent with stimulus-and stereotyped-belief driven accounts of the angry-male bias. Taken together, the evidence suggests considerable stability in the interaction between some facial dimensions in social categorization that is present prior to the onset of formal schooling. PMID:25859238
Genetic and Epigenetic Variations Induced by Wheat-Rye 2R and 5R Monosomic Addition Lines

PubMed Central

Fu, Shulan; Sun, Chuanfei; Yang, Manyu; Fei, Yunyan; Tan, Feiqun; Yan, Benju; Ren, Zhenglong; Tang, Zongxiang

2013-01-01

Background Monosomic alien addition lines (MAALs) can easily induce structural variation of chromosomes and have been used in crop breeding; however, it is unclear whether MAALs will induce drastic genetic and epigenetic alterations. Methodology/Principal Findings In the present study, wheat-rye 2R and 5R MAALs together with their selfed progeny and parental common wheat were investigated through amplified fragment length polymorphism (AFLP) and methylation-sensitive amplification polymorphism (MSAP) analyses. The MAALs in different generations displayed different genetic variations. Some progeny that only contained 42 wheat chromosomes showed great genetic/epigenetic alterations. Cryptic rye chromatin has introgressed into the wheat genome. However, one of the progeny that contained cryptic rye chromatin did not display outstanding genetic/epigenetic variation. 78 and 49 sequences were cloned from changed AFLP and MSAP bands, respectively. Blastn search indicated that almost half of them showed no significant similarity to known sequences. Retrotransposons were mainly involved in genetic and epigenetic variations. Genetic variations basically affected Gypsy-like retrotransposons, whereas epigenetic alterations affected Copia-like and Gypsy-like retrotransposons equally. Genetic and epigenetic variations seldom affected low-copy coding DNA sequences. Conclusions/Significance The results in the present study provided direct evidence to illustrate that monosomic wheat-rye addition lines could induce different and drastic genetic/epigenetic variations and these variations might not be caused by introgression of rye chromatins into wheat. Therefore, MAALs may be directly used as an effective means to broaden the genetic diversity of common wheat. PMID:23342073
Selective Infection of Antigen-Specific B Lymphocytes by Salmonella Mediates Bacterial Survival and Systemic Spreading of Infection

PubMed Central

de Wit, Jelle; Martinoli, Chiara; Zagato, Elena; Janssen, Hans; Jorritsma, Tineke; Bar-Ephraïm, Yotam E.; Rescigno, Maria; Neefjes, Jacques; van Ham, S. Marieke

2012-01-01

Background The bacterial pathogen Salmonella causes worldwide disease. A major route of intestinal entry involves M cells, providing access to B cell-rich Peyer’s Patches. Primary human B cells phagocytose Salmonella typhimurium upon recognition by the specific surface Ig receptor (BCR). As it is unclear how Salmonella disseminates systemically, we studied whether Salmonella can use B cells as a transport device for spreading. Methodology/Principal Findings Human primary B cells or Ramos cell line were incubated with GFP-expressing Salmonella. Intracellular survival and escape was studied in vitro by live cell imaging, flow cytometry and flow imaging. HEL-specific B cells were transferred into C57BL/6 mice and HEL-expressing Salmonella spreading in vivo was analyzed investigating mesenteric lymph nodes, spleen and blood. After phagocytosis by B cells, Salmonella survives intracellularly in a non-replicative state which is actively maintained by the B cell. Salmonella is later excreted followed by reproductive infection of other cell types. Salmonella-specific B cells thus act both as a survival niche and a reservoir for reinfection. Adoptive transfer of antigen-specific B cells before oral infection of mice showed that these B cells mediate in vivo systemic spreading of Salmonella to spleen and blood. Conclusions/Significance This is a first example of a pathogenic bacterium that abuses the antigen-specific cells of the adaptive immune system for systemic spreading for dissemination of infection. PMID:23209805
Neural Circuitry of Emotional and Cognitive Conflict Revealed through Facial Expressions

PubMed Central

Chiew, Kimberly S.; Braver, Todd S.

2011-01-01

Background Neural systems underlying conflict processing have been well studied in the cognitive realm, but the extent to which these overlap with those underlying emotional conflict processing remains unclear. A novel adaptation of the AX Continuous Performance Task (AX-CPT), a stimulus-response incompatibility paradigm, was examined that permits close comparison of emotional and cognitive conflict conditions, through the use of affectively-valenced facial expressions as the response modality. Methodology/Principal Findings Brain activity was monitored with functional magnetic resonance imaging (fMRI) during performance of the emotional AX-CPT. Emotional conflict was manipulated on a trial-by-trial basis, by requiring contextually pre-cued facial expressions to emotional probe stimuli (IAPS images) that were either affectively compatible (low-conflict) or incompatible (high-conflict). The emotion condition was contrasted against a matched cognitive condition that was identical in all respects, except that probe stimuli were emotionally neutral. Components of the brain cognitive control network, including dorsal anterior cingulate cortex (ACC) and lateral prefrontal cortex (PFC), showed conflict-related activation increases in both conditions, but with higher activity during emotion conditions. In contrast, emotion conflict effects were not found in regions associated with affective processing, such as rostral ACC. Conclusions/Significance These activation patterns provide evidence for a domain-general neural system that is active for both emotional and cognitive conflict processing. In line with previous behavioural evidence, greatest activity in these brain regions occurred when both emotional and cognitive influences additively combined to produce increased interference. PMID:21408006
Anomaly detection in hyperspectral imagery: statistics vs. graph-based algorithms

NASA Astrophysics Data System (ADS)

Berkson, Emily E.; Messinger, David W.

2016-05-01

Anomaly detection (AD) algorithms are frequently applied to hyperspectral imagery, but different algorithms produce different outlier results depending on the image scene content and the assumed background model. This work provides the first comparison of anomaly score distributions between common statistics-based anomaly detection algorithms (RX and subspace-RX) and the graph-based Topological Anomaly Detector (TAD). Anomaly scores in statistical AD algorithms should theoretically approximate a chi-squared distribution; however, this is rarely the case with real hyperspectral imagery. The expected distribution of scores found with graph-based methods remains unclear. We also look for general trends in algorithm performance with varied scene content. Three separate scenes were extracted from the hyperspectral MegaScene image taken over downtown Rochester, NY with the VIS-NIR-SWIR ProSpecTIR instrument. In order of most to least cluttered, we study an urban, suburban, and rural scene. The three AD algorithms were applied to each scene, and the distributions of the most anomalous 5% of pixels were compared. We find that subspace-RX performs better than RX, because the data becomes more normal when the highest variance principal components are removed. We also see that compared to statistical detectors, anomalies detected by TAD are easier to separate from the background. Due to their different underlying assumptions, the statistical and graph-based algorithms highlighted different anomalies within the urban scene. These results will lead to a deeper understanding of these algorithms and their applicability across different types of imagery.
Myosin Light Chain Kinase Mediates Intestinal Barrier Disruption following Burn Injury

PubMed Central

Chen, Chuanli; Wang, Pei; Su, Qin; Wang, Shiliang; Wang, Fengjun

2012-01-01

Background Severe burn injury results in the loss of intestinal barrier function, however, the underlying mechanism remains unclear. Myosin light chain (MLC) phosphorylation mediated by MLC kinase (MLCK) is critical to the pathophysiological regulation of intestinal barrier function. We hypothesized that the MLCK-dependent MLC phosphorylation mediates the regulation of intestinal barrier function following burn injury, and that MLCK inhibition attenuates the burn-induced intestinal barrier disfunction. Methodology/Principal Findings Male balb/c mice were assigned randomly to either sham burn (control) or 30% total body surface area (TBSA) full thickness burn without or with intraperitoneal injection of ML-9 (2 mg/kg), an MLCK inhibitor. In vivo intestinal permeability to fluorescein isothiocyanate (FITC)-dextran was measured. Intestinal mucosa injury was assessed histologically. Tight junction proteins ZO-1, occludin and claudin-1 was analyzed by immunofluorescent assay. Expression of MLCK and phosphorylated MLC in ileal mucosa was assessed by Western blot. Intestinal permeability was increased significantly after burn injury, which was accompanied by mucosa injury, tight junction protein alterations, and increase of both MLCK and MLC phosphorylation. Treatment with ML-9 attenuated the burn-caused increase of intestinal permeability, mucosa injury, tight junction protein alterations, and decreased MLC phosphorylation, but not MLCK expression. Conclusions/Significance The MLCK-dependent MLC phosphorylation mediates intestinal epithelial barrier dysfunction after severe burn injury. It is suggested that MLCK-dependent MLC phosphorylation may be a critical target for the therapeutic treatment of intestinal epithelial barrier disruption after severe burn injury. PMID:22529961
Th17 Cells and Activated Dendritic Cells Are Increased in Vitiligo Lesions

PubMed Central

Fuentes-Duculan, Judilyn; Moussai, Dariush; Gulati, Nicholas; Sullivan-Whalen, Mary; Gilleaudeau, Patricia; Cohen, Jules A.; Krueger, James G.

2011-01-01

Background Vitiligo is a common skin disorder, characterized by progressive skin de-pigmentation due to the loss of cutaneous melanocytes. The exact cause of melanocyte loss remains unclear, but a large number of observations have pointed to the important role of cellular immunity in vitiligo pathogenesis. Methodology/Principal Findings In this study, we characterized T cell and inflammation-related dermal dendritic cell (DC) subsets in pigmented non-lesional, leading edge and depigmented lesional vitiligo skin. By immunohistochemistry staining, we observed enhanced populations of CD11c+ myeloid dermal DCs and CD207+ Langerhans cells in leading edge vitiligo biopsies. DC-LAMP+ and CD1c+ sub-populations of dermal DCs expanded significantly in leading edge and lesional vitiligo skin. We also detected elevated tissue mRNA levels of IL-17A in leading edge skin biopsies of vitiligo patients, as well as IL-17A positive T cells by immunohistochemistry and immunofluorescence. Langerhans cells with activated inflammasomes were also noted in lesional vitiligo skin, along with increased IL-1ß mRNA, which suggest the potential of Langerhans cells to drive Th17 activation in vitiligo. Conclusions/Significance These studies provided direct tissue evidence that implicates active Th17 cells in vitiligo skin lesions. We characterized new cellular immune elements, in the active margins of vitiligo lesions (e.g. populations of epidermal and dermal dendritic cells subsets), which could potentially drive the inflammatory responses. PMID:21541348
Dihydroartemisinin Enhances Apo2L/TRAIL-Mediated Apoptosis in Pancreatic Cancer Cells via ROS-Mediated Up-Regulation of Death Receptor 5

PubMed Central

Cheng, Zhuo-xin; Wang, Yong-wei; Mu, Ming; Wang, Shuang-jia; Pan, Shang-ha; Gao, Yue; Jiang, Hong-chi; Dong, De-li; Sun, Bei

2012-01-01

Background Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown antitumor activity in various cancer cells. Apo2 ligand or tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) is regarded as a promising anticancer agent, but chemoresistance affects its efficacy as a treatment strategy. Apoptosis induced by the combination of DHA and Apo2L/TRAIL has not been well documented, and the mechanisms involved remain unclear. Methodology/Principal Findings Here, we report that DHA enhances the efficacy of Apo2L/TRAIL for the treatment of pancreatic cancer. We found that combined therapy using DHA and Apo2L/TRAIL significantly enhanced apoptosis in BxPC-3 and PANC-1 cells compared with single-agent treatment in vitro. The effect of DHA was mediated through the generation of reactive oxygen species, the induction of death receptor 5 (DR5) and the modulation of apoptosis-related proteins. However, N-acetyl cysteine significantly reduced the enhanced apoptosis observed with the combination of DHA and Apo2L/TRAIL. In addition, knockdown of DR5 by small interfering RNA also significantly reduced the amount of apoptosis induced by DHA and Apo2L/TRAIL. Conclusions/Significance These results suggest that DHA enhances Apo2L/TRAIL-mediated apoptosis in human pancreatic cancer cells through reactive oxygen species-mediated up-regulation of DR5. PMID:22666346
Are schools and alcohol a good mix? A qualitative study of school principals' experiences of adults' alcohol use in Australian secondary schools.

PubMed

Ward, Bernadette M; Buykx, Penny; Munro, Geoffrey; Wiggers, John

2016-08-01

Parents, schools and the broader community influence children's socialisation to alcohol. In Australia, the UK and the USA, there have been media reports of adults consuming alcohol at family-focused school events such as fairs and graduations. The aim of this qualitative study was to describe school principals' experiences of adults' use of alcohol at school events, when children are present. A qualitative study was undertaken. Publicly available lists were used to invite 60 principals from government and Catholic secondary schools in Victoria, Australia. In-depth interviews were conducted and analysed thematically and reported using the Consolidated Criteria for Reporting Qualitative Research guidelines. 14 principals (5 female, 9 male) participated. Most (10) of the participating principals reported adults' use of alcohol at events when students were present. Regarding these events, most principals reported concerns regarding potential harms and responsibility for decision-making about alcohol availability in schools. Some (4) principals believed alcohol should not be present at such events and this was their practice. Half of the participating schools had recently made changes to reduce the availability or management of alcohol at school functions. The findings confirm the common use of alcohol by adults at school events, the challenges this poses for school principals and suggests consideration needs to be given to identifying strategies for supporting schools and school principals in decision-making regarding the conduct of such events. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
The Preventive Control of a Dengue Disease Using Pontryagin Minimum Principal

NASA Astrophysics Data System (ADS)

Ratna Sari, Eminugroho; Insani, Nur; Lestari, Dwi

2017-06-01

Behaviour analysis for host-vector model without control of dengue disease is based on the value of basic reproduction number obtained using next generation matrices. Furthermore, the model is further developed involving a preventive control to minimize the contact between host and vector. The purpose is to obtain an optimal preventive strategy with minimal cost. The Pontryagin Minimum Principal is used to find the optimal control analytically. The derived optimality model is then solved numerically to investigate control effort to reduce infected class.
South Carolina's timber, 1968

Treesearch

Herbert A. Knight; Joe P. McClure

1968-01-01

This report represents the principal findings of the fourth Forest Survey of South Carolina's timber resource. The survey was started in August 1966 and completed in July 1968. Findings of the three previous surveys, completed in 1936, 1947, and 1958, provide the basis for measuring changes that have occurred and trends that have developed over the past 32 years....
Forest statistics for Georgia, 1997

Treesearch

Michael T. Thompson

1998-01-01

This report summarizes a 1997 inventory of the forest resources for the State of Georgia. Major findings are highlighted in text and graphs; detailed data are presented in 51 tables. This report highlights the principal findings of the seventh forest survey of Georgia. Field work began in November 1995 and was completed in April 1998. Six previous surveys,...

The Effective Elementary School Principal: Theoretical Bases, Research Findings and Practical Implications.

ERIC Educational Resources Information Center

Burnett, I. Emett, Jr.; Pankake, Anita M.

Although much of the current school reform movement relies on the basic assumption of effective elementary school administration, insufficient effort has been made to synthesize key concepts found in organizational theory and management studies with relevant effective schools research findings. This paper attempts such a synthesis to help develop…
Beyond Interdisciplinary Teaming: Findings and Implications of the NASSP National Middle Level Study.

ERIC Educational Resources Information Center

Hackmann, Donald G.; Petzko, Vicki N.; Valentine, Jerry W.; Clark, Donald C.; Nori, John R.; Lucas, Stephen E.

2002-01-01

Reports trends and implications of interdisciplinary teaming practices in middle schools, based on findings from a national survey. Noting that nearly 80 percent of schools currently implement teaming, challenges principals and teachers to move beyond simple formation of teams to the creation of an infrastructure that supports high-performing…
Forest statistics for the Piedmont of South Carolina

Treesearch

William H.B. Haines

1967-01-01

This report presents the principal findings of the fourth Forest Survey in the Piedmont of South Carolina, completed in February 1967. Findings of the three earlier surveys, completed in 1936, 1947, and 1958, provide the basis for measuring the changes that have occurred and the trends that have developed over the past 30 years.
Virginia's timber, 1966

Treesearch

Herbert A. Knight; Joe P. McClure

1966-01-01

This report presents the principal findings of the third Forest survey of Virginia's timber resource. The resurvey was started in November 1964 and completed in August 1966. Findings of the two previous surveys, completed in 1940 and 1957, provide the basis for measuring the changes that have been occurred and the trends that have developed during the past 26...
Florida's timber, 1970

Treesearch

Herbert A. Knight; Joe P. McClure

1970-01-01

This report presents the principal findings of the fourth Forest Survey of Florida's timber resource, The survey was started in July 1968 and completed in June 1970. Findings of the three previous surveys, completed in 1936, 1949, and 1959, provide the basis for measuring changes that have occurred and trends that have developed over the past 34 years. In this...
Visionary Democratic Leaders of Very Small Districts: Getting the Job Done Right.

ERIC Educational Resources Information Center

McGuire, Jerry

1994-01-01

Findings from a survey of rural school administrators in Oregon include profiles of three superintendent-principals that practice democratic leadership. Findings contrast with a national study that painted a discouraging picture of rural schooling in which few superintendents had a vision of working with people in collaborative ways. (LP)
Behavioral Characteristics Rated by District Education Officers (DEOs) for Effective Principalship

ERIC Educational Resources Information Center

Ahmad, Imtiaz; Khawaja, Mumtaz; Hussain, Muhammad Ather; Panhwar, Uzma; Farshad, Muhammad

2017-01-01

The purpose of this study was to investigate, by means of quantitative research methods, District Education Officers (DEOs) perceptions regarding the behavioral characteristics of effective secondary school principals. The major findings were based on the results of the eight interviews conducted with DEOs. In an effort to determine the findings,…
Principal component analysis and the locus of the Fréchet mean in the space of phylogenetic trees.

PubMed

Nye, Tom M W; Tang, Xiaoxian; Weyenberg, Grady; Yoshida, Ruriko

2017-12-01

Evolutionary relationships are represented by phylogenetic trees, and a phylogenetic analysis of gene sequences typically produces a collection of these trees, one for each gene in the analysis. Analysis of samples of trees is difficult due to the multi-dimensionality of the space of possible trees. In Euclidean spaces, principal component analysis is a popular method of reducing high-dimensional data to a low-dimensional representation that preserves much of the sample's structure. However, the space of all phylogenetic trees on a fixed set of species does not form a Euclidean vector space, and methods adapted to tree space are needed. Previous work introduced the notion of a principal geodesic in this space, analogous to the first principal component. Here we propose a geometric object for tree space similar to the [Formula: see text]th principal component in Euclidean space: the locus of the weighted Fréchet mean of [Formula: see text] vertex trees when the weights vary over the [Formula: see text]-simplex. We establish some basic properties of these objects, in particular showing that they have dimension [Formula: see text], and propose algorithms for projection onto these surfaces and for finding the principal locus associated with a sample of trees. Simulation studies demonstrate that these algorithms perform well, and analyses of two datasets, containing Apicomplexa and African coelacanth genomes respectively, reveal important structure from the second principal components.
Sexuality and HIV Education in Charter Schools: An Exploratory Study With Principals in San Diego County, California.

PubMed

Walsh-Buhi, Eric R; Dao, Brandon; Salgin, Linda; Marshall, James; Miller, Rachel; Fisher, Doug; Walsh-Buhi, Margaret

2017-04-01

Schools can address critical sexual and reproductive health (SRH) issues among youth. However, little is known about SRH education being implemented in charter schools. Thus, our purpose was to explore implementation of SRH education in charter schools. Using purposive sampling, semistructured telephone interviews were conducted with 20 charter school principals in San Diego County, California. Questions were guided by the Kaiser Family Foundation National Survey of Public Secondary School Principals. Analyses followed a case-oriented approach, examining aspects within each case (ie, a principal), and then a comparative analysis of a small number of cases (ie, all principals). Overall, 17 principals acknowledged offering sexuality education in the previous 2 years. Over half of these schools had provided content on: sexually transmitted diseases/human immunodeficiency virus/acquired immune deficiency syndrome (STDs/HIV/AIDS), reproduction/pregnancy/birth, pregnancy prevention methods, delaying sex, and managing sexual pressure. Condom use, sexual assault, sexual orientation, talking with partners about STD/pregnancy prevention, talking with parents about relationships/sex, and using/where to get contraception were less commonly taught. Abortion was not addressed. When asked the grade they would assign to their schools' sexuality/HIV instruction, principals assigned 1 A, 7 Bs, 7 Cs, and 1 D. Consistency between our findings and what has been reported elsewhere varies. As charter schools often have greater curricular flexibility than traditional schools, this study provides unique preliminary data to inform future innovative, or strengthen existing, SRH programming. © 2017, American School Health Association.
[The principal components analysis--method to classify the statistical variables with applications in medicine].

PubMed

Dascălu, Cristina Gena; Antohe, Magda Ecaterina

2009-01-01

Based on the eigenvalues and the eigenvectors analysis, the principal component analysis has the purpose to identify the subspace of the main components from a set of parameters, which are enough to characterize the whole set of parameters. Interpreting the data for analysis as a cloud of points, we find through geometrical transformations the directions where the cloud's dispersion is maximal--the lines that pass through the cloud's center of weight and have a maximal density of points around them (by defining an appropriate criteria function and its minimization. This method can be successfully used in order to simplify the statistical analysis on questionnaires--because it helps us to select from a set of items only the most relevant ones, which cover the variations of the whole set of data. For instance, in the presented sample we started from a questionnaire with 28 items and, applying the principal component analysis we identified 7 principal components--or main items--fact that simplifies significantly the further data statistical analysis.
PumpKin: A tool to find principal pathways in plasma chemical models

NASA Astrophysics Data System (ADS)

Markosyan, A. H.; Luque, A.; Gordillo-Vázquez, F. J.; Ebert, U.

2014-10-01

PumpKin is a software package to find all principal pathways, i.e. the dominant reaction sequences, in chemical reaction systems. Although many tools are available to integrate numerically arbitrarily complex chemical reaction systems, few tools exist in order to analyze the results and interpret them in relatively simple terms. In particular, due to the large disparity in the lifetimes of the interacting components, it is often useful to group reactions into pathways that recycle the fastest species. This allows a researcher to focus on the slow chemical dynamics, eliminating the shortest timescales. Based on the algorithm described by Lehmann (2004), PumpKin automates the process of finding such pathways, allowing the user to analyze complex kinetics and to understand the consumption and production of a certain species of interest. We designed PumpKin with an emphasis on plasma chemical systems but it can also be applied to atmospheric modeling and to industrial applications such as plasma medicine and plasma-assisted combustion.
Principal opium alkaloids as possible biochemical markers for the source identification of Indian opium.

PubMed

Mohana, Mudiam; Reddy, Krishna; Jayshanker, Gurumurthy; Suresh, Velayudhan; Sarin, Rajendra Kumar; Sashidhar, R B

2005-08-01

A total of 124 opium samples originating from different licit opium growing divisions of India were analyzed for their principal alkaloid (thebaine, codeine, morphine, papaverine, and narcotine) content by capillary zone electrophoresis (CZE) without derivatization or purification. Absence of papaverine in Bareilly, Tilhar, and most of the samples originating from Kota is a significant observation in relation to the source of Indian opium. Multiple discriminant analysis was applied to the quantitative principal alkaloid data to determine an optimal classifier in order to evaluate the source of Indian opium. The predictive value based on the discriminant analysis was found to be 85% in relation to the source of opium and the study also revealed that all the principal alkaloids have to be analyzed for source identification of Indian opium. Chemometrics performed with principal alkaloids analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz., group I, II, and III. The methodology developed may find wide forensic application in identifying the source of licit or illicit opium originating from India, and to differentiate it from opium originating from other opium producing countries.
Does comorbid Social Anxiety Disorder impact the clinical presentation of principal Major Depressive Disorder?

PubMed

Dalrymple, Kristy L; Zimmerman, Mark

2007-06-01

Although previous research has examined comorbidity in principal Social Anxiety Disorder (SAD), few studies have examined the disorders for which those with comorbid SAD seek treatment. Further, studies have shown that depressive disorders often are associated with SAD, but few have examined the clinical characteristics of patients with this particular comorbidity. The current study examined the prevalence of various principal Axis I disorders in 577 individuals diagnosed with comorbid SAD. Consistent with previous research, Major Depressive Disorder (MDD) was the most frequent principal diagnosis in patients with comorbid SAD. Those with principal MDD and comorbid SAD (MDD-SAD) were compared to those with MDD without SAD (MDD) on demographic and clinical characteristics. Patients with MDD-SAD versus those with MDD were more severe in terms of social functioning, duration of depressive episode, suicidal ideation, time out of work, presence of current alcohol abuse/dependence, and age of onset of MDD. Social functioning, duration of episode, suicidal ideation, and age of onset of MDD remained significant even after controlling for additional comorbid disorders. Findings suggest the need for future research to determine how treatments could be adapted for this commonly occurring comorbidity.
Past Participle Formation in Specific Language Impairment

ERIC Educational Resources Information Center

Kauschke, Christina; Renner, Lena F.; Domahs, Ulrike

2017-01-01

Background: German participles are formed by a co-occurrence of prefixation and suffixation. While the acquisition of regular and irregular suffixation has been investigated exhaustively, it is still unclear how German children master the prosodically determined prefixation rule (prefix "ge-"). Findings reported in the literature are…
Forest statistics for Northeast Florida 1970

Treesearch

Joe P. McClure

1970-01-01

This report highlights the principal findings of the fourth Forest Survey of the timber resource in Northeast Florida. The survey was started in February 1969 and completed in November 1969. Findings of the three previous surveys, completed in 1934, 1949, and 1959, provide the basis for measuring changes that have occurred and trends that have developed over the...
Forest statistics for Northwest Florida, 1969

Treesearch

Herbert A. Knight

1969-01-01

This report highlights the principal findings of the fourth Forest survey of the timber resource in Northwest Florida. The survey was started in July 19 68 and completed in March 1969. Findings of the three previous surveys, completed in 1934, 1949, and 1959, provide the basis for measuring changes that have occurred and trends that have developed over the past 35...
Forest statistics for South Florida, 1970

Treesearch

Thomas R. Bellamy; Herbert A. Knight

1970-01-01

This report highlights the principal findings of the fourth Forest Survey of the timber resource in South Florida. The survey was started in February 1970 and completed in March 1970. Findings of the three previous surveys, completed in 1936, 1949, and 1959, provide the basis for measuring changes that have occurred and trends that have developed over the past 34...
Forest statistics for North Georgia, 1998

Treesearch

Michael T. Thompson

1998-01-01

This report summarizes a 1998 inventory of the forest resources of a 21-county area of Georgia. Major findings are highlighted in text and graphs; detailed data are presented in 51 tables. This report highlights the principal findings of the seventh forest survey of North Georgia. Field work began in October 1997 and was completed in April 1998. Six previous...
Forest statistics for the Northern Coastal Plain of South Carolina 1968

Treesearch

Richard L. Welch

1968-01-01

This report presents the principal findings of the fourth Forest Survey in the Piedmont of South Carolina, completed in February 1967. Findings of the three earlier surveys, completed in 1936, 1947, and 1958, provide the basis for measuring the changes that have occurred and the trends that have developed over the past 30 years.
Forest statistics for the Southern Coastal Plain of South Carolina

Treesearch

Noel D. Cost

1968-01-01

This report presents the principal findings of the fourth Forest Survey in the Piedmont of South Carolina, completed in February 1967. Findings of the three earlier surveys, completed in 1936, 1947, and 1958, provide the basis for measuring the changes that have occurred and the trends that have developed over the past 30 years.

Pupil Mobility, Choice and the Secondary School Market: Assumptions and Realities

ERIC Educational Resources Information Center

Dobson, Janet

2008-01-01

This paper examines assumptions which underpin the promotion of a quasi-market in the English secondary school system in light of research findings on pupil mobility--that is, children joining and leaving schools at non-standard times. It draws principally on research funded by the Nuffield Foundation and reports findings of a study of pupil…
The Impacts of New Governance on Teaching at German Universities. Findings from a National Survey

ERIC Educational Resources Information Center

Wilkesmann, Uwe; Schmid, Christian J.

2012-01-01

In this article we will present findings from a national survey questioning the actual impact of the new governance structures at German universities on academic teaching. To begin with, we give a theoretical underpinning to the economization of higher education institutions (HEIs) according to Principal-Agent Theory. This allows for the…
Secondary Schools in 2012: Main Findings from the NZCER National Survey

ERIC Educational Resources Information Center

Wylie, Cathy

2013-01-01

This report contains the main findings from the New Zealand Council for Educational Research's (NZCER's) 2012 national survey of secondary schools. The survey draws on responses from more than half the country's secondary school principals and from hundreds of teachers, parents and members of boards of trustees, and was carried out in July and…
Primary and Intermediate Schools in 2013: Main Findings from the NZCER National Survey

ERIC Educational Resources Information Center

Wylie, Cathy; Bonne, Linda

2014-01-01

This report presents the main findings from the NZCER national survey of primary and intermediate schools, conducted in July and August 2013. It reports on the views of principals, teachers, boards of trustees and parents. It covers many aspects of school experience, including school resources, school interactions with government agencies, the…
Individual Differences in Susceptibility to Inattentional Blindness

ERIC Educational Resources Information Center

Seegmiller, Janelle K.; Watson, Jason M.; Strayer, David L.

2011-01-01

Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by…
In–Depth Characterization of Viral Isolates from Plasma and Cells Compared with Plasma Circulating Quasispecies in Early HIV-1 Infection

PubMed Central

Erkizia, Itziar; Pino, Maria; Pou, Christian; Paredes, Roger; Clotet, Bonaventura; Martinez-Picado, Javier; Prado, Julia G.

2012-01-01

Background The use of in vitro models to unravel the phenotypic characteristics of circulating viral variants is key to understanding HIV-1 pathogenesis but limited by the availability of primary viral isolates from biological samples. However, overall in vivo genetic variability of HIV-1 within a subject may not be reflected in the viable viral population obtained after isolation. Although several studies have tried to determine whether viral populations expanded in vitro are representative of in vivo findings, the answer remains unclear due to the reduced number of clonal sequences analyzed or samples compared. In order to overcome previous experimental limitations, here we applied Deep Pyrosequencing (DPS) technology in combination with phenotypic experiments to analyze and compare with unprecedented detail the composition of viral isolates and in vivo quasispecies. Methodology/Principal Findings We amplified by DPS HIV-1 genomic regions covering gag, protease, integrase and env-V3 to characterize paired isolates from plasma and peripheral blood mononuclear cells and compare them with total plasma viral RNA in four recently HIV-1 infected subjects. Our study demonstrated the presence of unique haplotypes scattered between sample types with conservation of major variants. In addition, no differences in intra- and inter-population encoded protein variability were found between the different types of isolates or when these were compared to plasma viral RNA within subjects. Additionally, in vitro experiments demonstrated phenotypic similarities in terms of replicative capacity and co-receptor usage between viral isolates and plasma viral RNA. Conclusion This study is the first in-depth comparison and characterization of viral isolates from different sources and plasma circulating quasispecies using DPS in recently HIV-1 infected subjects. Our data supports the use of primary isolates regardless of their plasma or cellular origin to define genetic variability and biological traits of circulating HIV-1 quasispecies. PMID:22393441
Serum Metabolomic Profiling in Acute Alcoholic Hepatitis Identifies Multiple Dysregulated Pathways

PubMed Central

Rachakonda, Vikrant; Gabbert, Charles; Raina, Amit; Bell, Lauren N.; Cooper, Sara; Malik, Shahid; Behari, Jaideep

2014-01-01

Background and Objectives While animal studies have implicated derangements of global energy homeostasis in the pathogenesis of acute alcoholic hepatitis (AAH), the relevance of these findings to the development of human AAH remains unclear. Using global, unbiased serum metabolomics analysis, we sought to characterize alterations in metabolic pathways associated with severe AAH and identify potential biomarkers for disease prognosis. Methods This prospective, case-control study design included 25 patients with severe AAH and 25 ambulatory patients with alcoholic cirrhosis. Serum samples were collected within 24 hours of the index clinical encounter. Global, unbiased metabolomics profiling was performed. Patients were followed for 180 days after enrollment to determine survival. Results Levels of 234 biochemicals were altered in subjects with severe AAH. Random-forest analysis, principal component analysis, and integrated hierarchical clustering methods demonstrated that metabolomics profiles separated the two cohorts with 100% accuracy. Severe AAH was associated with enhanced triglyceride lipolysis, impaired mitochondrial fatty acid beta oxidation, and upregulated omega oxidation. Low levels of multiple lysolipids and related metabolites suggested decreased plasma membrane remodeling in severe AAH. While most measured bile acids were increased in severe AAH, low deoxycholate and glycodeoxycholate levels indicated intestinal dysbiosis. Several changes in substrate utilization for energy homeostasis were identified in severe AAH, including increased glucose consumption by the pentose phosphate pathway, altered tricarboxylic acid (TCA) cycle activity, and enhanced peptide catabolism. Finally, altered levels of small molecules related to glutathione metabolism and antioxidant vitamin depletion were observed in patients with severe AAH. Univariable logistic regression revealed 15 metabolites associated with 180-day survival in severe AAH. Conclusion Severe AAH is characterized by a distinct metabolic phenotype spanning multiple pathways. Metabolomics profiling revealed a panel of biomarkers for disease prognosis, and future studies are planned to validate these findings in larger cohorts of patients with severe AAH. PMID:25461442
14-3-3ε Overexpression Contributes to Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma

PubMed Central

Liang, Shu-Man; Chen, Shyh-Chang; Wang, John; Hsu, Chiun; Wu, Yao-Ming; Liou, Jun-Yang

2013-01-01

Background 14-3-3ε is implicated in regulating tumor progression, including hepatocellular carcinoma (HCC). Our earlier study indicated that elevated 14-3-3ε expression is significantly associated with higher risk of metastasis and lower survival rates of HCC patients. However, the molecular mechanisms of how 14-3-3ε regulates HCC tumor metastasis are still unclear. Methodology and Principal Findings In this study, we show that increased 14-3-3ε expression induces HCC cell migration and promotes epithelial-mesenchymal transition (EMT), which is determined by the reduction of E-cadherin expression and induction of N-cadherin and vimentin expression. Knockdown with specific siRNA abolished 14-3-3ε-induced cell migration and EMT. Furthermore, 14-3-3ε selectively induced Zeb-1 and Snail expression, and 14-3-3ε-induced cell migration was abrogated by Zeb-1 or Snail siRNA. In addition, the effect of 14-3-3ε-reduced E-cadherin was specifically restored by Zeb-1 siRNA. Positive 14-3-3ε expression was significantly correlated with negative E-cadherin expression, as determined by immunohistochemistry analysis in HCC tumors. Analysis of 14-3-3ε/E-cadherin expression associated with clinicopathological characteristics revealed that the combination of positive 14-3-3ε and negative E-cadherin expression is significantly correlated with higher incidence of HCC metastasis and poor 5-year overall survival. In contrast, patients with positive 14-3-3ε and positive E-cadherin expression had better prognostic outcomes than did those with negative E-cadherin expression. Significance Our findings show for the first time that E-cadherin is one of the downstream targets of 14-3-3ε in modulating HCC tumor progression. Thus, 14-3-3ε may act as an important regulator in modulating tumor metastasis by promoting EMT as well as cell migration, and it may serve as a novel prognostic biomarker or therapeutic target for HCC. PMID:23483955
A New Saurichthyiform (Actinopterygii) with a Crushing Feeding Mechanism from the Middle Triassic of Guizhou (China)

PubMed Central

Wu, Feixiang; Chang, Mee-mann; Sun, Yuanlin; Xu, Guanghui

2013-01-01

Background Equipped with an effective predatory feeding mechanism enhanced by large and sharp teeth, pointed snout and elongate body, saurichthyiform fishes are considered common fish-eaters in the early Mesozoic aquatic ecosystems. Additionally, because of the similar body plan across species, saurichthyiforms are also regarded evolutionally conservative, with few morphological and ecological changes during their long history. However, their phylogenetic affinity remains unclear as to whether they are chondrostean, neopterygian or stem-actinopteran, and likewise the intrarelationships of the group have rarely been explored. Methodology/Principal Findings Here we report a new saurichthyiform from the Middle Triassic of Guizhou, China, based on the well-preserved specimens including a 3-D braincase. The new taxon, Yelangichthys macrocephalus gen. et sp. nov., is unique among saurichthyiforms in having a peculiar neurocranium with a broad orbital tectum, paired posterior myodomes, a deep, transverse fossa in the posterodorsal part of the orbit, and a feeding mechanism structured for durophagy. Phylogenetic analysis places Yelangichthys gen. nov. at the most basal position in the Saurichthyiformes as the sister to Saurichthyidae, and a new family Yelangichthyidae is erected to include only Y. macrocephalus gen. et sp. nov. The monophyly of the Chondrostei comprising [Saurichthyiformes + Acipenseriformes] Birgeriiformes is supported, but not the monophyly of Saurichthys, the type genus of Saurichthyidae. With its outstanding osteological details, Yelangichthys gen. nov. greatly increases the neurocranial variations in saurichthyiforms, and its novel feeding structure suggests the consumption of hard-preys instead of fishes. Conclusions/Significance Our findings highlight the detailed osteology of a saurichthyiform braincase and its feeding design. We suggest that saurichthyiforms are closely allied to the Acipenseriformes. Saurichthyiforms were very diverse in the cranial osteology and they might have undergone a rapid evolutionary radiation via, for the new material here, transforming the feeding mechanism and thus exploiting the food resources unsuitable for other saurichthyiforms. PMID:24324657
Associations of Educational Attainment, Occupation, Social Class and Major Depressive Disorder among Han Chinese Women

PubMed Central

Liu, Feihu; Li, Yajuan; Wang, Junhui; Flint, Jonathan; Gao, Jingfang; Li, Youhui; Tao, Ming; Zhang, Kerang; Wang, Xumei; Gao, Chengge; Yang, Lijun; Li, Kan; Shi, Shenxun; Wang, Gang; Liu, Lanfen; Zhang, Jinbei; Du, Bo; Jiang, Guoqing; Shen, Jianhua; Zhang, Zhen; Liang, Wei; Sun, Jing; Hu, Jian; Liu, Tiebang; Wang, Xueyi; Miao, Guodong; Meng, Huaqing; Li, Yi; Hu, Chunmei; Li, Yi; Huang, Guoping; Li, Gongying; Ha, Baowei; Deng, Hong; Mei, Qiyi; Zhong, Hui; Gao, Shugui; Sang, Hong; Zhang, Yutang; Fang, Xiang; Yu, Fengyu; Yang, Donglin; Liu, Tieqiao; Chen, Yunchun; Hong, Xiaohong; Wu, Wenyuan; Chen, Guibing; Cai, Min; Song, Yan; Pan, Jiyang; Dong, Jicheng; Pan, Runde; Zhang, Wei; Shen, Zhenming; Liu, Zhengrong; Gu, Danhua; Wang, Xiaoping; Liu, Xiaojuan; Zhang, Qiwen; Li, Yihan; Chen, Yiping; Kendler, Kenneth S.

2014-01-01

Background The prevalence of major depressive disorder (MDD) is higher in those with low levels of educational attainment, the unemployed and those with low social status. However the extent to which these factors cause MDD is unclear. Most of the available data comes from studies in developed countries, and these findings may not extrapolate to developing countries. Examining the relationship between MDD and socio economic status in China is likely to add to the debate because of the radical economic and social changes occurring in China over the last 30 years. Principal findings We report results from 3,639 Chinese women with recurrent MDD and 3,800 controls. Highly significant odds ratios (ORs) were observed between MDD and full time employment (OR = 0.36, 95% CI = 0.25–0.46, logP = 78), social status (OR = 0.83, 95% CI = 0.77–0.87, logP = 13.3) and education attainment (OR = 0.90, 95% CI = 0.86–0.90, logP = 6.8). We found a monotonic relationship between increasing age and increasing levels of educational attainment. Those with only primary school education have significantly more episodes of MDD (mean 6.5, P-value = 0.009) and have a clinically more severe disorder, while those with higher educational attainment are likely to manifest more comorbid anxiety disorders. Conclusions In China lower socioeconomic position is associated with increased rates of MDD, as it is elsewhere in the world. Significantly more episodes of MDD occur among those with lower educational attainment (rather than longer episodes of disease), consistent with the hypothesis that the lower socioeconomic position increases the likelihood of developing MDD. The phenomenology of MDD varies according to the degree of educational attainment: higher educational attainment not only appears to protect against MDD but alters its presentation, to a more anxious phenotype. PMID:24497966
Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach

PubMed Central

Sindato, Calvin; Stevens, Kim B.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Paweska, Janusz T.; Pfeiffer, Dirk U.

2016-01-01

Background Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Materials and Methods Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Principal Findings Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). Conclusion/Significance The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics. PMID:27654268
Antioxidant Protects against Increases in Low Molecular Weight Hyaluronan and Inflammation in Asphyxiated Newborn Pigs Resuscitated with 100% Oxygen

PubMed Central

Akgul, Yucel; Ramgopal, Mrithyunjay; Mija, Dan S.; Cheong, Naeun; Longoria, Christopher; Mahendroo, Mala; Nakstad, Britt; Saugstad, Ola D.; Savani, Rashmin C.

2012-01-01

Background Newborn resuscitation with 100% oxygen is associated with oxidative-nitrative stresses and inflammation. The mechanisms are unclear. Hyaluronan (HA) is fragmented to low molecular weight (LMW) by oxidative-nitrative stresses and can promote inflammation. We examined the effects of 100% oxygen resuscitation and treatment with the antioxidant, N-acetylcysteine (NAC), on lung 3-nitrotyrosine (3-NT), LMW HA, inflammation, TNFα and IL1ß in a newborn pig model of resuscitation. Methods & Principal Findings Newborn pigs (n = 40) were subjected to severe asphyxia, followed by 30 min ventilation with either 21% or 100% oxygen, and were observed for the subsequent 150 minutes in 21% oxygen. One 100% oxygen group was treated with NAC. Serum, bronchoalveolar lavage (BAL), lung sections, and lung tissue were obtained. Asphyxia resulted in profound hypoxia, hypercarbia and metabolic acidosis. In controls, HA staining was in airway subepithelial matrix and no 3-NT staining was seen. At the end of asphyxia, lavage HA decreased, whereas serum HA increased. At 150 minutes after resuscitation, exposure to 100% oxygen was associated with significantly higher BAL HA, increased 3NT staining, and increased fragmentation of lung HA. Lung neutrophil and macrophage contents, and serum TNFα and IL1ß were higher in animals with LMW than those with HMW HA in the lung. Treatment of 100% oxygen animals with NAC blocked nitrative stress, preserved HMW HA, and decreased inflammation. In vitro, peroxynitrite was able to fragment HA, and macrophages stimulated with LMW HA increased TNFα and IL1ß expression. Conclusions & Significance Compared to 21%, resuscitation with 100% oxygen resulted in increased peroxynitrite, fragmentation of HA, inflammation, as well as TNFα and IL1ß expression. Antioxidant treatment prevented the expression of peroxynitrite, the degradation of HA, and also blocked increases in inflammation and inflammatory cytokines. These findings provide insight into potential mechanisms by which exposure to hyperoxia results in systemic inflammation. PMID:22701723
Climate Change Risks and Conservation Implications for a Threatened Small-Range Mammal Species

PubMed Central

Morueta-Holme, Naia; Fløjgaard, Camilla; Svenning, Jens-Christian

2010-01-01

Background Climate change is already affecting the distributions of many species and may lead to numerous extinctions over the next century. Small-range species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modeling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, even for rare and cryptic species. Methodology/Principal Findings We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus), which is a phylogenetically isolated insectivore endemic to south-western Europe. Atlas data on the distribution of G. pyrenaicus was linked to data on climate, topography and human impact using two species distribution modeling algorithms to test hypotheses on the factors that determine the range for this species. Predictive models were developed and projected onto climate scenarios for 2070–2099 to assess climate change risks and conservation possibilities. Mean summer temperature and water balance appeared to be the main factors influencing the distribution of G. pyrenaicus. Climate change was predicted to result in significant reductions of the species' range. However, the severity of these reductions was highly dependent on which predictor was the most important limiting factor. Notably, if mean summer temperature is the main range determinant, G. pyrenaicus is at risk of near total extinction in Spain under the most severe climate change scenario. The range projections for Europe indicate that assisted migration may be a possible long-term conservation strategy for G. pyrenaicus in the face of global warming. Conclusions/Significance Climate change clearly poses a severe threat to this illustrative endemic species. Our findings confirm that endemic species can be highly vulnerable to a warming climate and highlight the fact that assisted migration has potential as a conservation strategy for species threatened by climate change. PMID:20454451
Methylation of p15INK4b and Expression of ANRIL on Chromosome 9p21 Are Associated with Coronary Artery Disease

PubMed Central

Zhuang, Jianhui; Peng, Wenhui; Li, Hailing; Wang, Wei; Wei, Yidong; Li, Weiming; Xu, Yawei

2012-01-01

Background Genome-wide association studies have identified that multiple single nucleiotide polymorphisms on chromosome 9p21 are tightly associated with coronary artery disease (CAD). However, the mechanism linking this risk locus to CAD remains unclear. Methodology/Principal Findings The methylation status of six candidate genes (BAX, BCL-2, TIMP3, p14ARF, p15INK4b and p16INK4a) in 205 patients and controls who underwent coronary angiography were analyzed by quantitative MethyLight assay. Rs10757274 was genotyped and expression of INK4/ARF and antisense non-coding RNA in the INK4 locus (ANRIL) was determined by real-time RT-PCR. Compared with controls, DNA methylation levels at p15INK4b significantly increased in CAD patients (p = 0.006). To validate and dissect the methylation percentage of each target CpG site at p15INK4b, pyrosequencing was performed, finding CpG +314 and +332 remarkably hypermethylated in CAD patients. Further investigation determined that p15INK4b hypermethylation prevalently emerged in lymphocytes of CAD patients (p = 0.013). The rs10757274 genotype was significantly associated with CAD (p = 0.003) and GG genotype carriers had a higher level of ANRIL exon 1–5 expression compared among three genotypes (p = 0.009). There was a stepwise increase in p15INK4b and p16INK4a methylation as ANRIL exon 1–5 expression elevated (r = 0.23, p = 0.001 and r = 0.24, p = 0.001, respectively), although neither of two loci methylation was directly linked to rs10757274 genotype. Conclusions/Significance p15INK4b methylation is associated with CAD and ANRIL expression. The epigenetic changes in p15INK4b methylation and ANRIL expression may involve in the mechanisms of chromosome 9p21 on CAD development. PMID:23091611
Discontinuation and non-publication of randomised clinical trials supported by the main public funding body in Switzerland: a retrospective cohort study.

PubMed

Amstutz, Alain; Schandelmaier, Stefan; Frei, Roy; Surina, Jakub; Agarwal, Arnav; Olu, Kelechi Kalu; Alturki, Reem; Von Niederhäusern, Belinda; Von Elm, Erik; Briel, Matthias

2017-08-01

The Swiss National Science Foundation (SNSF) promotes academic excellence through competitive selection of study proposals and rigorous evaluation of feasibility, but completion status and publication history of SNSF-supported randomised clinical trials (RCTs) remain unclear. The main objectives were to review all healthcare RCTs supported by the SNSF for trial discontinuation and non-publication, to investigate potential risk factors for trial discontinuation due to poor recruitment and non-publication, and to compare findings to other Swiss RCTs not supported by the SNSF. We established a retrospective cohort of all SNSF-supported RCTs for which recruitment and funding had ended in 2015 or earlier. For each RCT, two investigators independently searched corresponding publications in electronic databases. In addition, we approached all principal investigators to ask for additional publications and information about trial discontinuation. Teams of two investigators independently extracted details about study design, recruitment of participants, outcomes, analysis and sample size from the original proposal and, if available, from trial registries and publications. We used multivariable regression analysis to explore potential risk factors associated with discontinuation due to poor recruitment and with non-publication, and to compare our results with data from a previous cohort of Swiss RCTs not supported by the SNSF. We included 101 RCTs supported by the SNSF between 1986 and 2015. Eighty-seven (86%) principal investigators responded to our survey. Overall, 69 (68%) RCTs were completed, 26 (26%) RCTs were prematurely discontinued (all due to slow recruitment) and the completion status remained unclear for 6 (6%) RCTs. For analysing publication status, we excluded 4 RCTs for which follow-up was still ongoing and 9 for which manuscripts were still in preparation. Of the remaining 88 RCTs, 53 (60%) were published as full articles in peer-reviewed journals. Multivariable regression models suggested that discontinued trials were at higher risk for non-publication than completed trials (adjusted OR 7.61; 95% CI 2.44 to 27.09). Compared with other Swiss RCTs, the risk of discontinuation for SNSF-supported RCTs was higher than in industry-initiated RCTs (adjusted OR 3.84; 95% CI 1.68 to 8.74), but not significantly different from investigator-initiated RCTs not supported by the SNSF (adjusted OR 1.05; 95% CI 0.51 to 2.11). We found no evidence that the proportion of discontinued or unpublished RCTs decreased over the last 20 years. One out of four SNSF-supported RCTs were prematurely discontinued due to slow recruitment, 40% of all included RCTs and 70% of all discontinued RCTs were not published in peer-reviewed journals. There is a case to reconsider how public funding bodies such as the SNSF could improve their feasibility assessment and promote publication of RCTs irrespective of completion status. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Can Principals Promote Teacher Development as Evaluators? A Case Study of Principals’ Views and Experiences

PubMed Central

Kraft, Matthew A.; Gilmour, Allison

2017-01-01

Purpose New teacher evaluation systems have expanded the role of principals as instructional leaders, but little is known about principals’ ability to promote teacher development through the evaluation process. We conducted a case study of principals’ perspectives on evaluation and their experiences implementing observation and feedback cycles to better understand whether principals feel as though they are able to promote teacher development as evaluators. Research Methods We conducted interviews with a stratified random sample of 24 principals in an urban district that recently implemented major reforms to its teacher evaluation system. We analyzed these interviews by drafting thematic summaries, coding interview transcripts, creating data-analytic matrices, and writing analytic memos. Findings We found that the evaluation reforms provided a common framework and language that helped facilitate principals’ feedback conversations with teachers. However, we also found that tasking principals with primary responsibility for conducting evaluations resulted in a variety of unintended consequences which undercut the quality of evaluation feedback they provided. We analyze five broad solutions to these challenges: strategically targeting evaluations, reducing operational responsibilities, providing principal training, hiring instructional coaches, and developing peer evaluation systems. Implications The quality of feedback teachers receive through the evaluation process depends critically on the time and training evaluators have to provide individualized and actionable feedback. Districts that task principals with primary responsibility for conducting observation and feedback cycles must attend to the many implementation challenges associated with this approach in order for next-generation evaluation systems to successfully promote teacher development. PMID:28729742
Adequacy of Reporting Results of School Surveys and Nonresponse Effects: A Review of the Literature and a Case Study

ERIC Educational Resources Information Center

Kano, Megumi; Franke, Todd; Afifi, Abdelmonem A.; Bourque, Linda B.

2008-01-01

To ensure accurate interpretation of research findings, researchers should report details about their research design, data collection method, and response rates when presenting findings from survey research. A review of 100 peer-reviewed articles reporting the results of survey research on K-12 schools with principals as the designated…
Visual Attention Modulates Insight versus Analytic Solving of Verbal Problems

ERIC Educational Resources Information Center

Wegbreit, Ezra; Suzuki, Satoru; Grabowecky, Marcia; Kounios, John; Beeman, Mark

2012-01-01

Behavioral and neuroimaging findings indicate that distinct cognitive and neural processes underlie solving problems with sudden insight. Moreover, people with less focused attention sometimes perform better on tests of insight and creative problem solving. However, it remains unclear whether different states of attention, within individuals,…
40 CFR 59.208 - Charcoal lighter material testing protocol.

Code of Federal Regulations, 2011 CFR

2011-07-01

... grams per start. The manufacturer or importer shall maintain the report of findings. (c) When a charcoal... protocol, or are unclear (subject to different interpretations) and inadequate, the Administrator must be... to this subpart shall demonstrate compliance with the applicable requirements of § 59.203(d) using...
40 CFR 59.208 - Charcoal lighter material testing protocol.

Code of Federal Regulations, 2010 CFR

2010-07-01

... grams per start. The manufacturer or importer shall maintain the report of findings. (c) When a charcoal... protocol, or are unclear (subject to different interpretations) and inadequate, the Administrator must be... to this subpart shall demonstrate compliance with the applicable requirements of § 59.203(d) using...

A Critical Analysis of Research on the Overjustification Effect.

ERIC Educational Resources Information Center

Berkay, Paul James

This document examined studies of the overjustification effect. Many studies examining the phenomenon were conducted during the 1970s; findings appeared to be accepted without qualification. It is unclear whether researchers conducted the studies with the proper methodologies and interpreted results correctly. Such factors included the type of…
Flexibility in Statistical Word Segmentation: Finding Words in Foreign Speech

ERIC Educational Resources Information Center

Graf Estes, Katharine; Gluck, Stephanie Chen-Wu; Bastos, Carolina

2015-01-01

The present experiments investigated the flexibility of statistical word segmentation. There is ample evidence that infants can use statistical cues (e.g., syllable transitional probabilities) to segment fluent speech. However, it is unclear how effectively infants track these patterns in unfamiliar phonological systems. We examined whether…
Does Marijuana Use Lead to Aggression and Violent Behavior?

ERIC Educational Resources Information Center

Ostrowsky, Michael K.

2011-01-01

Marijuana use and violent behavior are causing widespread public concern. This article reviews theory and research on the relation between marijuana use and aggressive/violent behavior. It is evident from the inconsistent findings in the literature that the exact nature of the relation remains unclear. This article identifies several possible…
Pitfalls in the Evaluation of Teachers by Principals.

ERIC Educational Resources Information Center

Natriello, Gary; Dornbusch, Sanford M.

1980-01-01

Presents the findings of several studies of evaluation processes and identifies a model that helps to make explicit the components of the evaluation process. Suggests rules of thumb for conducting successful evaluations. (Author/JM)
Food-web stability signals critical transitions in temperate shallow lakes

PubMed Central

Kuiper, Jan J.; van Altena, Cassandra; de Ruiter, Peter C.; van Gerven, Luuk P. A.; Janse, Jan H.; Mooij, Wolf M.

2015-01-01

A principal aim of ecologists is to identify critical levels of environmental change beyond which ecosystems undergo radical shifts in their functioning. Both food-web theory and alternative stable states theory provide fundamental clues to mechanisms conferring stability to natural systems. Yet, it is unclear how the concept of food-web stability is associated with the resilience of ecosystems susceptible to regime change. Here, we use a combination of food web and ecosystem modelling to show that impending catastrophic shifts in shallow lakes are preceded by a destabilizing reorganization of interaction strengths in the aquatic food web. Analysis of the intricate web of trophic interactions reveals that only few key interactions, involving zooplankton, diatoms and detritus, dictate the deterioration of food-web stability. Our study exposes a tight link between food-web dynamics and the dynamics of the whole ecosystem, implying that trophic organization may serve as an empirical indicator of ecosystem resilience. PMID:26173798
‘If you are good, I get better’: the role of social hierarchy in perceptual decision-making

PubMed Central

Pannunzi, Mario; Ayneto, Alba; Deco, Gustavo; Sebastián-Gallés, Nuria

2014-01-01

So far, it was unclear if social hierarchy could influence sensory or perceptual cognitive processes. We evaluated the effects of social hierarchy on these processes using a basic visual perceptual decision task. We constructed a social hierarchy where participants performed the perceptual task separately with two covertly simulated players (superior, inferior). Participants were faster (better) when performing the discrimination task with the superior player. We studied the time course when social hierarchy was processed using event-related potentials and observed hierarchical effects even in early stages of sensory-perceptual processing, suggesting early top–down modulation by social hierarchy. Moreover, in a parallel analysis, we fitted a drift-diffusion model (DDM) to the results to evaluate the decision making process of this perceptual task in the context of a social hierarchy. Consistently, the DDM pointed to nondecision time (probably perceptual encoding) as the principal period influenced by social hierarchy. PMID:23946003
Urban parasitology: visceral leishmaniasis in Brazil.

PubMed

Harhay, Michael O; Olliaro, Piero L; Costa, Dorcas Lamounier; Costa, Carlos Henrique Nery

2011-09-01

Since the early 1980s, visceral leishmaniasis (VL) which is, in general, a rural zoonotic disease, has spread to the urban centers of the north, and now the south and west of Brazil. The principal drivers differ between cities, though human migration, large urban canid populations (animal reservoir), and a decidedly peripatetic and adaptable sand fly vector are the primary forces. The exact number of urban cases remains unclear as a result of challenges with surveillance. However, the number of urban cases registered continues to increase annually. Most control initiatives (e.g. culling infected dogs and household spraying to kill the sand fly) could be effective, but have proven hard to maintain at large scales due to logistical, financial and other reasons. In this article, the urbanization of VL in Brazil is reviewed, touching on these and other topics related to controlling VL within and outside Brazil. Copyright © 2011 Elsevier Ltd. All rights reserved.
Does the graft-tunnel friction influence knee joint kinematics and biomechanics after anterior cruciate ligament reconstruction? A finite element study.

PubMed

Wan, Chao; Hao, Zhixiu

2018-02-01

Graft tissues within bone tunnels remain mobile for a long time after anterior cruciate ligament (ACL) reconstruction. However, whether the graft-tunnel friction affects the finite element (FE) simulation of the ACL reconstruction is still unclear. Four friction coefficients (from 0 to 0.3) were simulated in the ACL-reconstructed joint model as well as two loading levels of anterior tibial drawer. The graft-tunnel friction did not affect joint kinematics and the maximal principal strain of the graft. By contrast, both the relative graft-tunnel motion and equivalent strain for the bone tunnels were altered, which corresponded to different processes of graft-tunnel integration and bone remodeling, respectively. It implies that the graft-tunnel friction should be defined properly for studying the graft-tunnel integration or bone remodeling after ACL reconstruction using numerical simulation.
Non-fluent speech following stroke is caused by impaired efference copy.

PubMed

Feenaughty, Lynda; Basilakos, Alexandra; Bonilha, Leonardo; den Ouden, Dirk-Bart; Rorden, Chris; Stark, Brielle; Fridriksson, Julius

2017-09-01

Efference copy is a cognitive mechanism argued to be critical for initiating and monitoring speech: however, the extent to which breakdown of efference copy mechanisms impact speech production is unclear. This study examined the best mechanistic predictors of non-fluent speech among 88 stroke survivors. Objective speech fluency measures were subjected to a principal component analysis (PCA). The primary PCA factor was then entered into a multiple stepwise linear regression analysis as the dependent variable, with a set of independent mechanistic variables. Participants' ability to mimic audio-visual speech ("speech entrainment response") was the best independent predictor of non-fluent speech. We suggest that this "speech entrainment" factor reflects integrity of internal monitoring (i.e., efference copy) of speech production, which affects speech initiation and maintenance. Results support models of normal speech production and suggest that therapy focused on speech initiation and maintenance may improve speech fluency for individuals with chronic non-fluent aphasia post stroke.
Chocolate: food for moods.

PubMed

Wong, S Y; Lua, P L

2011-08-01

Chocolate is a popular food and its consumption has long been associated with enjoyment and pleasure. The effect of chocolate on mood too has long been recognised. Chocolate is thought to have interactions with neurotransmitters which contribute to mood modulation and appetite regulation. However, the evidence in chocolate and mood studies remains highly controversial. As more is known about the influence of chocolate on mood, the reasons for these effects appear increasingly complex and inter-related. We reviewed chocolate's properties and the principal hypotheses addressing its mood altering propensities. The relationship between chocolate and mood are highly complex, combining psychopharmacological components, nutritional and sensory characteristics of the food. Individual and situational differences on chocolate consumption may also exert influence on mood and the mixed results in previous research indicate that the direction of the association remains unclear. The association between chocolate consumption and emotions warrants further multi-prong investigations to substantiate chocolate's mood alterating propensity.
Magma storage in a strike-slip caldera

PubMed Central

Saxby, J.; Gottsmann, J.; Cashman, K.; Gutiérrez, E.

2016-01-01

Silicic calderas form during explosive volcanic eruptions when magma withdrawal triggers collapse along bounding faults. The nature of specific interactions between magmatism and tectonism in caldera-forming systems is, however, unclear. Regional stress patterns may control the location and geometry of magma reservoirs, which in turn may control the spatial and temporal development of faults. Here we provide new insight into strike-slip volcano-tectonic relations by analysing Bouguer gravity data from Ilopango caldera, El Salvador, which has a long history of catastrophic explosive eruptions. The observed low gravity beneath the caldera is aligned along the principal horizontal stress orientations of the El Salvador Fault Zone. Data inversion shows that the causative low-density structure extends to ca. 6 km depth, which we interpret as a shallow plumbing system comprising a fractured hydrothermal reservoir overlying a magmatic reservoir with vol% exsolved vapour. Fault-controlled localization of magma constrains potential vent locations for future eruptions. PMID:27447932
Magma storage in a strike-slip caldera.

PubMed

Saxby, J; Gottsmann, J; Cashman, K; Gutiérrez, E

2016-07-22

Silicic calderas form during explosive volcanic eruptions when magma withdrawal triggers collapse along bounding faults. The nature of specific interactions between magmatism and tectonism in caldera-forming systems is, however, unclear. Regional stress patterns may control the location and geometry of magma reservoirs, which in turn may control the spatial and temporal development of faults. Here we provide new insight into strike-slip volcano-tectonic relations by analysing Bouguer gravity data from Ilopango caldera, El Salvador, which has a long history of catastrophic explosive eruptions. The observed low gravity beneath the caldera is aligned along the principal horizontal stress orientations of the El Salvador Fault Zone. Data inversion shows that the causative low-density structure extends to ca. 6 km depth, which we interpret as a shallow plumbing system comprising a fractured hydrothermal reservoir overlying a magmatic reservoir with vol% exsolved vapour. Fault-controlled localization of magma constrains potential vent locations for future eruptions.
Untangling the Links among Athletic Involvement, Gender, Race, and Adolescent Academic Outcomes.

PubMed

Miller, Kathleen E; Melnick, Merrill J; Barnes, Grace M; Farrell, Michael P; Sabo, Don

2005-06-01

Although previous research has established that high school sports participation may be associated with positive academic outcomes, the parameters of the relationship remain unclear. Using a longitudinal sample of nearly 600 Western New York adolescents, this study examined gender- and race-specific differences in the impact of two dimensions of adolescent athletic involvement ("jock" identity and athlete status) on changes in school grades and school misconduct over a two-year interval. Female and black adolescents who identified themselves as "jocks" reported lower grades than those who did not, whereas female athletes reported higher grades than female nonathletes. Jocks also reported significantly more misconduct (including skipping school, cutting classes, having someone from home called to the school for disciplinary purposes, and being sent to the principal's office) than nonjocks. Gender moderated the relationship between athlete status and school misconduct; athletic participation had a less salutary effect on misconduct for girls than for boys.
A morphological basis for orientation tuning in primary visual cortex.

PubMed

Mooser, François; Bosking, William H; Fitzpatrick, David

2004-08-01

Feedforward connections are thought to be important in the generation of orientation-selective responses in visual cortex by establishing a bias in the sampling of information from regions of visual space that lie along a neuron's axis of preferred orientation. It remains unclear, however, which structural elements-dendrites or axons-are ultimately responsible for conveying this sampling bias. To explore this question, we have examined the spatial arrangement of feedforward axonal connections that link non-oriented neurons in layer 4 and orientation-selective neurons in layer 2/3 of visual cortex in the tree shrew. Target sites of labeled boutons in layer 2/3 resulting from focal injections of biocytin in layer 4 show an orientation-specific axial bias that is sufficient to confer orientation tuning to layer 2/3 neurons. We conclude that the anisotropic arrangement of axon terminals is the principal source of the orientation bias contributed by feedforward connections.
Structural basis for m7G recognition and 2'-O-methyl discrimination in capped RNAs by the innate immune receptor RIG-I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devarkar, Swapnil C.; Wang, Chen; Miller, Matthew T.

The cytosolic innate immune receptor Retinoic Acid Inducible Gene-I (RIG-I) is the principal detector of pathogenic RNAs carrying a 5'-triphosphate (5'ppp). Self RNAs like mRNAs evade recognition by RIG-I due to posttranscriptional modifications like 5'-end capping with 7-methyl guanosine (m7G) and 2'-O-methylation of 5'-end nucleotides. Viruses have also evolved mechanisms to mimic these modifications, which in part is believed to aid in immune evasion. Currently, it is unclear how these modifications modulate RIG-I recognition. This paper provides structural and mechanistic insights into the roles of the m7G cap and 2'-O-methylation in RIG-I evasion. We show that RIG-I accommodates the m7Gmore » base while maintaining the 5'ppp contacts and can recognize Cap-0 RNAs but not Cap-1.« less
Protons Regulate Vesicular Glutamate Transporters through an Allosteric Mechanism.

PubMed

Eriksen, Jacob; Chang, Roger; McGregor, Matt; Silm, Katlin; Suzuki, Toshiharu; Edwards, Robert H

2016-05-18

The quantal nature of synaptic transmission requires a mechanism to transport neurotransmitter into synaptic vesicles without promoting non-vesicular efflux across the plasma membrane. Indeed, the vesicular transport of most classical transmitters involves a mechanism of H(+) exchange, which restricts flux to acidic membranes such as synaptic vesicles. However, vesicular transport of the principal excitatory transmitter glutamate depends primarily on membrane potential, which would drive non-vesicular efflux, and the role of protons is unclear. Adapting electrophysiology to record currents associated with the vesicular glutamate transporters (VGLUTs), we characterize a chloride conductance that is gated by lumenal protons and chloride and supports glutamate uptake. Rather than coupling stoichiometrically to glutamate flux, lumenal protons and chloride allosterically activate vesicular glutamate transport. Gating by protons serves to inhibit what would otherwise be substantial non-vesicular glutamate efflux at the plasma membrane, thereby restricting VGLUT activity to synaptic vesicles. Copyright © 2016 Elsevier Inc. All rights reserved.
Functional Strain-Line Pattern in the Human Left Ventricle

NASA Astrophysics Data System (ADS)

Pedrizzetti, Gianni; Kraigher-Krainer, Elisabeth; De Luca, Alessio; Caracciolo, Giuseppe; Mangual, Jan O.; Shah, Amil; Toncelli, Loira; Domenichini, Federico; Tonti, Giovanni; Galanti, Giorgio; Sengupta, Partho P.; Narula, Jagat; Solomon, Scott

2012-07-01

Analysis of deformations in terms of principal directions appears well suited for biological tissues that present an underlying anatomical structure of fiber arrangement. We applied this concept here to study deformation of the beating heart in vivo analyzing 30 subjects that underwent accurate three-dimensional echocardiographic recording of the left ventricle. Results show that strain develops predominantly along the principal direction with a much smaller transversal strain, indicating an underlying anisotropic, one-dimensional contractile activity. The strain-line pattern closely resembles the helical anatomical structure of the heart muscle. These findings demonstrate that cardiac contraction occurs along spatially variable paths and suggest a potential clinical significance of the principal strain concept for the assessment of mechanical cardiac function. The same concept can help in characterizing the relation between functional and anatomical properties of biological tissues, as well as fiber-reinforced engineered materials.
Social functioning in youth with anxiety disorders: association with anxiety severity and outcomes from cognitive-behavioral therapy.

PubMed

Settipani, Cara A; Kendall, Philip C

2013-02-01

Social functioning was assessed using the Child Behavior Checklist and Teacher Report Form for children with anxiety disorders who participated in a randomized clinical trial (N = 161, aged 7-14). Significant relationships were found between severity of children's principal anxiety disorder and most measures of social functioning, such that poorer social functioning was associated with more severe anxiety. Among youth who received cognitive-behavioral therapy (n = 111), significant associations were found between parent-reported social competence and both absence of principal anxiety disorder and lower anxiety severity at posttreatment and 1-year follow-up, controlling for the severity of the child's principal anxiety disorder at pretreatment. Findings support a relationship between anxiety severity and social difficulties, and suggest the importance of social competence for a favorable treatment response.
Selection and Presentation of Imaging Figures in the Medical Literature

PubMed Central

Siontis, George C. M.; Patsopoulos, Nikolaos A.; Vlahos, Antonios P.; Ioannidis, John P. A.

2010-01-01

Background Images are important for conveying information, but there is no empirical evidence on whether imaging figures are properly selected and presented in the published medical literature. We therefore evaluated the selection and presentation of radiological imaging figures in major medical journals. Methodology/Principal Findings We analyzed articles published in 2005 in 12 major general and specialty medical journals that had radiological imaging figures. For each figure, we recorded information on selection, study population, provision of quantitative measurements, color scales and contrast use. Overall, 417 images from 212 articles were analyzed. Any comment/hint on image selection was made in 44 (11%) images (range 0–50% across the 12 journals) and another 37 (9%) (range 0–60%) showed both a normal and abnormal appearance. In 108 images (26%) (range 0–43%) it was unclear whether the image came from the presented study population. Eighty-three images (20%) (range 0–60%) had any quantitative or ordered categorical value on a measure of interest. Information on the distribution of the measure of interest in the study population was given in 59 cases. For 43 images (range 0–40%), a quantitative measurement was provided for the depicted case and the distribution of values in the study population was also available; in those 43 cases there was no over-representation of extreme than average cases (p = 0.37). Significance The selection and presentation of images in the medical literature is often insufficiently documented; quantitative data are sparse and difficult to place in context. PMID:20526360
Depth of origin of ocean-circulation-induced magnetic signals

NASA Astrophysics Data System (ADS)

Irrgang, Christopher; Saynisch-Wagner, Jan; Thomas, Maik

2018-01-01

As the world ocean moves through the ambient geomagnetic core field, electric currents are generated in the entire ocean basin. These oceanic electric currents induce weak magnetic signals that are principally observable outside of the ocean and allow inferences about large-scale oceanic transports of water, heat, and salinity. The ocean-induced magnetic field is an integral quantity and, to first order, it is proportional to depth-integrated and conductivity-weighted ocean currents. However, the specific contribution of oceanic transports at different depths to the motional induction process remains unclear and is examined in this study. We show that large-scale motional induction due to the general ocean circulation is dominantly generated by ocean currents in the upper 2000 m of the ocean basin. In particular, our findings allow relating regional patterns of the oceanic magnetic field to corresponding oceanic transports at different depths. Ocean currents below 3000 m, in contrast, only contribute a small fraction to the ocean-induced magnetic signal strength with values up to 0.2 nT at sea surface and less than 0.1 nT at the Swarm satellite altitude. Thereby, potential satellite observations of ocean-circulation-induced magnetic signals are found to be likely insensitive to deep ocean currents. Furthermore, it is shown that annual temporal variations of the ocean-induced magnetic field in the region of the Antarctic Circumpolar Current contain information about sub-surface ocean currents below 1000 m with intra-annual periods. Specifically, ocean currents with sub-monthly periods dominate the annual temporal variability of the ocean-induced magnetic field.

Effects of Inhibition of Interleukin-6 Signalling on Insulin Sensitivity and Lipoprotein (A) Levels in Human Subjects with Rheumatoid Diseases

PubMed Central

Schultz, Olaf; Oberhauser, Frank; Saech, Jasemine; Rubbert-Roth, Andrea; Hahn, Moritz; Krone, Wilhelm; Laudes, Matthias

2010-01-01

Background Interleukin-6 (IL-6) is a pro-inflammatory cytokine that has been found to be increased in type 2 diabetic subjects. However, it still remains unclear if these elevated IL-6 levels are co-incidental or if this cytokine is causally related to the development of insulin resistance and type 2 diabetes in humans. Therefore, in the present study we examined insulin sensitivity, serum adipokine levels and lipid parameters in human subjects before and after treatment with the IL-6 receptor antibody Tocilizumab. Methodology/Principal Findings 11 non-diabetic patients with rheumatoid disease were included in the study. HOMA-IR was calculated and serum levels for leptin, adiponectin, triglycerides, LDL-cholesterol, HDL-cholesterol and lipoprotein (a) (Lp (a)) were measured before as well as one and three months after Tocilizumab treatment. The HOMA index for insulin resistance decreased significantly. While leptin concentrations were not altered by inhibition of IL-6 signalling, adiponectin concentrations significantly increased. Thus the leptin to adiponectin ratio, a novel marker for insulin resistance, exhibited a significant decrease. Serum triglycerides, LDL-cholesterol and HDL-cholesterol tended to be increased whereas Lp (a) levels significantly decreased. Conclusions/Significance Inhibition of IL-6 signalling improves insulin sensitivity in humans with immunological disease suggesting that elevated IL-6 levels in type 2 diabetic subjects might be causally involved in the pathogenesis of insulin resistance. Furthermore, our data indicate that inhibition of IL-6 signalling decreases Lp (a) serum levels, which might reduce the cardiovascular risk of human subjects. PMID:21179199
Honeybees Learn Odour Mixtures via a Selection of Key Odorants

PubMed Central

Reinhard, Judith; Sinclair, Michael; Srinivasan, Mandyam V.; Claudianos, Charles

2010-01-01

Background The honeybee has to detect, process and learn numerous complex odours from her natural environment on a daily basis. Most of these odours are floral scents, which are mixtures of dozens of different odorants. To date, it is still unclear how the bee brain unravels the complex information contained in scent mixtures. Methodology/Principal Findings This study investigates learning of complex odour mixtures in honeybees using a simple olfactory conditioning procedure, the Proboscis-Extension-Reflex (PER) paradigm. Restrained honeybees were trained to three scent mixtures composed of 14 floral odorants each, and then tested with the individual odorants of each mixture. Bees did not respond to all odorants of a mixture equally: They responded well to a selection of key odorants, which were unique for each of the three scent mixtures. Bees showed less or very little response to the other odorants of the mixtures. The bees' response to mixtures composed of only the key odorants was as good as to the original mixtures of 14 odorants. A mixture composed of the other, non-key-odorants elicited a significantly lower response. Neither an odorant's volatility or molecular structure, nor learning efficiencies for individual odorants affected whether an odorant became a key odorant for a particular mixture. Odorant concentration had a positive effect, with odorants at high concentration likely to become key odorants. Conclusions/Significance Our study suggests that the brain processes complex scent mixtures by predominantly learning information from selected key odorants. Our observations on key odorant learning lend significant support to previous work on olfactory learning and mixture processing in honeybees. PMID:20161714
Glucocorticoids are critical regulators of dendritic spine development and plasticity in vivo

PubMed Central

Liston, Conor; Gan, Wen-Biao

2011-01-01

Glucocorticoids are a family of hormones that coordinate diverse physiological processes in responding to stress. Prolonged glucocorticoid exposure over weeks has been linked to dendritic atrophy and spine loss in fixed tissue studies of adult brains, but it is unclear how glucocorticoids may affect the dynamic processes of dendritic spine formation and elimination in vivo. Furthermore, relatively few studies have examined the effects of stress and glucocorticoids on spines during the postnatal and adolescent period, which is characterized by rapid synaptogenesis followed by protracted synaptic pruning. To determine whether and to what extent glucocorticoids regulate dendritic spine development and plasticity, we used transcranial two-photon microscopy to track the formation and elimination of dendritic spines in vivo after treatment with glucocorticoids in developing and adult mice. Corticosterone, the principal murine glucocorticoid, had potent dose-dependent effects on dendritic spine dynamics, increasing spine turnover within several hours in the developing barrel cortex. The adult barrel cortex exhibited diminished baseline spine turnover rates, but these rates were also enhanced by corticosterone. Similar changes occurred in multiple cortical areas, suggesting a generalized effect. However, reducing endogenous glucocorticoid activity by dexamethasone suppression or corticosteroid receptor antagonists caused a substantial reduction in spine turnover rates, and the former was reversed by corticosterone replacement. Notably, we found that chronic glucocorticoid excess led to an abnormal loss of stable spines that were established early in life. Together, these findings establish a critical role for glucocorticoids in the development and maintenance of dendritic spines in the living cortex. PMID:21911374
Frontal Gamma-Aminobutyric Acid Concentrations Are Associated With Cognitive Performance in Older Adults.

PubMed

Porges, Eric C; Woods, Adam J; Edden, Richard A E; Puts, Nicolaas A J; Harris, Ashley D; Chen, Huaihou; Garcia, Amanda M; Seider, Talia R; Lamb, Damon G; Williamson, John B; Cohen, Ronald A

2017-01-01

Gamma-aminobutyric acid (GABA), the brain's principal inhibitory neurotransmitter, has been associated with perceptual and attentional functioning. Recent application of magnetic resonance spectroscopy (MRS) provides in vivo evidence for decreasing GABA concentrations during adulthood. It is unclear, however, how age-related decrements in cerebral GABA concentrations contribute to cognitive decline, or whether previously reported declines in cerebral GABA concentrations persist during healthy aging. We hypothesized that participants with higher GABA concentrations in the frontal cortex would exhibit superior cognitive function and that previously reported age-related decreases in cortical GABA concentrations continue into old age. We measured GABA concentrations in frontal and posterior midline cerebral regions using a Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) 1 H-MRS approach in 94 older adults without history or clinical evidence of mild cognitive impairment or dementia (mean age, 73 years). We administered the Montreal Cognitive Assessment to assess cognitive functioning. Greater frontal GABA concentrations were associated with superior cognitive performance. This relation remained significant after controlling for age, years of education, and brain atrophy. GABA concentrations in both frontal and posterior regions decreased as a function of age. These novel findings from a large, healthy, older population indicate that cognitive function is sensitive to cerebral GABA concentrations in the frontal cortex, and GABA concentration in frontal and posterior regions continue to decline in later age. These effects suggest that proton MRS may provide a clinically useful method for the assessment of normal and abnormal age-related cognitive changes and the associated physiological contributors.
Determining In Vivo Regulation of Cardiac Pyruvate Dehydrogenase Based on Label Flux from Hyperpolarized [1-13C]Pyruvate

PubMed Central

Heather, Lisa C.; Griffin, Julian L.; Clarke, Kieran; Radda, George K.; Tyler, Damian J.

2015-01-01

Background Pyruvate dehydrogenase (PDH) is a key regulator of cardiac substrate selection and is regulated by both pyruvate dehydrogenase kinase (PDK)-mediated phosphorylation and feedback inhibition. The extent to which chronic upregulation of PDK protein levels, acutely increased PDK activity and acute feedback inhibition limit PDH flux remains unclear because existing in vitro assessment methods inherently disrupt the enzyme complex. We have previously demonstrated that hyperpolarized 13C-labelled metabolic tracers with magnetic resonance spectroscopy (MRS) can monitor flux through PDH in vivo. The aim of this study was to determine the relative contributions of acute and chronic changes in PDK and PDH activities to in vivo myocardial PDH flux. Methodology/Principal Findings We examined both fed and fasted rats with either hyperpolarized [1-13C]pyruvate alone or hyperpolarized [1-13C]pyruvate co-infused with malate (to modulate mitochondrial NADH/NAD+ and acetyl-CoA/CoA ratios, which alter both PDH activity and flux). To confirm the metabolic fate of infused malate, we performed in vitro 1H NMR spectroscopy on cardiac tissue extracts. We observed that in fed rats, where PDH activity was high, the presence of malate increased PDH flux by 27%, whereas in the fasted state, malate infusion had no effect on PDH flux. Conclusions/Significance These observations suggest that pyruvate oxidation is limited by feedback inhibition from acetyl-CoA only when PDH activity is high. Therefore, in the case of PDH, and potentially other enzymes, hyperpolarized 13C MR can be used to non-invasively assess enzymatic regulation. PMID:21387444
Dopamine synapse is a neuroligin-2–mediated contact between dopaminergic presynaptic and GABAergic postsynaptic structures

PubMed Central

Uchigashima, Motokazu; Ohtsuka, Toshihisa; Kobayashi, Kazuto; Watanabe, Masahiko

2016-01-01

Midbrain dopamine neurons project densely to the striatum and form so-called dopamine synapses on medium spiny neurons (MSNs), principal neurons in the striatum. Because dopamine receptors are widely expressed away from dopamine synapses, it remains unclear how dopamine synapses are involved in dopaminergic transmission. Here we demonstrate that dopamine synapses are contacts formed between dopaminergic presynaptic and GABAergic postsynaptic structures. The presynaptic structure expressed tyrosine hydroxylase, vesicular monoamine transporter-2, and plasmalemmal dopamine transporter, which are essential for dopamine synthesis, vesicular filling, and recycling, but was below the detection threshold for molecules involving GABA synthesis and vesicular filling or for GABA itself. In contrast, the postsynaptic structure of dopamine synapses expressed GABAergic molecules, including postsynaptic adhesion molecule neuroligin-2, postsynaptic scaffolding molecule gephyrin, and GABAA receptor α1, without any specific clustering of dopamine receptors. Of these, neuroligin-2 promoted presynaptic differentiation in axons of midbrain dopamine neurons and striatal GABAergic neurons in culture. After neuroligin-2 knockdown in the striatum, a significant decrease of dopamine synapses coupled with a reciprocal increase of GABAergic synapses was observed on MSN dendrites. This finding suggests that neuroligin-2 controls striatal synapse formation by giving competitive advantage to heterologous dopamine synapses over conventional GABAergic synapses. Considering that MSN dendrites are preferential targets of dopamine synapses and express high levels of dopamine receptors, dopamine synapse formation may serve to increase the specificity and potency of dopaminergic modulation of striatal outputs by anchoring dopamine release sites to dopamine-sensing targets. PMID:27035941
Activated protein C ameliorates Bacillus anthracis lethal toxin-induced lethal pathogenesis in rats

PubMed Central

2012-01-01

Background Lethal toxin (LT) is a major virulence factor of Bacillus anthracis. Sprague Dawley rats manifest pronounced lung edema and shock after LT treatments, resulting in high mortality. The heart failure that is induced by LT has been suggested to be a principal mechanism of lung edema and mortality in rodents. Since LT-induced death occurs more rapidly in rats than in mice, suggesting that other mechanisms in addition to the heart dysfunction may be contributed to the fast progression of LT-induced pathogenesis in rats. Coagulopathy may contribute to circulatory failure and lung injury. However, the effect of LT on coagulation-induced lung dysfunction is unclear. Methods To investigate the involvement of coagulopathy in LT-mediated pathogenesis, the mortality, lung histology and coagulant levels of LT-treated rats were examined. The effects of activated protein C (aPC) on LT-mediated pathogenesis were also evaluated. Results Fibrin depositions were detected in the lungs of LT-treated rats, indicating that coagulation was activated. Increased levels of plasma D-dimer and thrombomodulin, and the ameliorative effect of aPC further suggested that the activation of coagulation-fibrinolysis pathways plays a role in LT-mediated pathogenesis in rats. Reduced mortality was associated with decreased plasma levels of D-dimer and thrombomodulin following aPC treatments in rats with LT-mediated pathogenesis. Conclusions These findings suggest that the activation of coagulation in lung tissue contributes to mortality in LT-mediated pathogenesis in rats. In addition, anticoagulant aPC may help to develop a feasible therapeutic strategy. PMID:23170801
At the centre of neuronal, synaptic and axonal pathology in murine prion disease: degeneration of neuroanatomically linked thalamic and brainstem nuclei

PubMed Central

Reis, Renata; Hennessy, Edel; Murray, Caoimhe; Griffin, Éadaoin W.

2015-01-01

Aims The processes by which neurons degenerate in chronic neurodegenerative diseases remain unclear. Synaptic loss and axonal pathology frequently precede neuronal loss and protein aggregation demonstrably spreads along neuroanatomical pathways in many neurodegenerative diseases. The spread of neuronal pathology is less studied. Methods We previously demonstrated severe neurodegeneration in the posterior thalamus of multiple prion disease strains. Here we used the ME7 model of prion disease to examine the nature of this degeneration in the posterior thalamus and the major brainstem projections into this region. Results We objectively quantified neurological decline between 16 and 18 weeks post‐inoculation and observed thalamic subregion‐selective neuronal, synaptic and axonal pathology while demonstrating relatively uniform protease‐resistant prion protein (PrP) aggregation and microgliosis across the posterior thalamus. Novel amyloid precursor protein (APP) pathology was particularly prominent in the thalamic posterior (PO) and ventroposterior lateral (VPL) nuclei. The brainstem nuclei forming the major projections to these thalamic nuclei were examined. Massive neuronal loss in the PO was not matched by significant neuronal loss in the interpolaris (Sp5I), while massive synaptic loss in the ventral posteromedial nucleus (VPM) did correspond with significant neuronal loss in the principal trigeminal nucleus. Likewise, significant VPL synaptic loss was matched by significant neuronal loss in the gracile and cuneate nuclei. Conclusion These findings demonstrate significant spread of neuronal pathology from the thalamus to the brainstem in prion disease. The divergent neuropathological features in adjacent neuronal populations demonstrates that there are discrete pathways to neurodegeneration in different neuronal populations. PMID:25727649
Root Interactions in a Maize/Soybean Intercropping System Control Soybean Soil-Borne Disease, Red Crown Rot

PubMed Central

Gao, Xiang; Wu, Man; Xu, Ruineng; Wang, Xiurong; Pan, Ruqian; Kim, Hye-Ji; Liao, Hong

2014-01-01

Background Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. Principal Findings In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum). The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. Conclusions To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices. PMID:24810161
Advances in Taxonomy, Ecology, and Biogeography of Dirivultidae (Copepoda) Associated with Chemosynthetic Environments in the Deep Sea

PubMed Central

Gollner, Sabine; Ivanenko, Viatcheslav N.; Arbizu, Pedro Martínez; Bright, Monika

2010-01-01

Background Copepoda is one of the most prominent higher taxa with almost 80 described species at deep-sea hydrothermal vents. The unique copepod family Dirivultidae with currently 50 described species is the most species rich invertebrate family at hydrothermal vents. Methodology/Principal Findings We reviewed the literature of Dirivultidae and provide a complete key to species, and map geographical and habitat specific distribution. In addition we discuss the ecology and origin of this family. Conclusions/Significance Dirivultidae are only present at deep-sea hydrothermal vents and along the axial summit trough of midocean ridges, with the exception of Dirivultus dentaneus found associated with Lamellibrachia species at 1125 m depth off southern California. To our current knowledge Dirivultidae are unknown from shallow-water vents, seeps, whale falls, and wood falls. They are a prominent part of all communities at vents and in certain habitat types (like sulfide chimneys colonized by pompei worms) they are the most abundant animals. They are free-living on hard substrate, mostly found in aggregations of various foundation species (e.g. alvinellids, vestimentiferans, and bivalves). Most dirivultid species colonize more than one habitat type. Dirivultids have a world-wide distribution, but most genera and species are endemic to a single biogeographic region. Their origin is unclear yet, but immigration from other deep-sea chemosynthetic habitats (stepping stone hypothesis) or from the deep-sea sediments seems unlikely, since Dirivultidae are unknown from these environments. Dirivultidae is the most species rich family and thus can be considered the most successful taxon at deep-sea vents. PMID:20838422
R-Flurbiprofen Reduces Neuropathic Pain in Rodents by Restoring Endogenous Cannabinoids

PubMed Central

Marian, Claudiu; Häussler, Annett; Wijnvoord, Nina; Ziebell, Simone; Metzner, Julia; Koch, Marco; Myrczek, Thekla; Bechmann, Ingo; Kuner, Rohini; Costigan, Michael; Dehghani, Faramarz; Geisslinger, Gerd; Tegeder, Irmgard

2010-01-01

Background R-flurbiprofen, one of the enantiomers of flurbiprofen racemate, is inactive with respect to cyclooxygenase inhibition, but shows analgesic properties without relevant toxicity. Its mode of action is still unclear. Methodology/Principal Findings We show that R-flurbiprofen reduces glutamate release in the dorsal horn of the spinal cord evoked by sciatic nerve injury and thereby alleviates pain in sciatic nerve injury models of neuropathic pain in rats and mice. This is mediated by restoring the balance of endocannabinoids (eCB), which is disturbed following peripheral nerve injury in the DRGs, spinal cord and forebrain. The imbalance results from transcriptional adaptations of fatty acid amide hydrolase (FAAH) and NAPE-phospholipase D, i.e. the major enzymes involved in anandamide metabolism and synthesis, respectively. R-flurbiprofen inhibits FAAH activity and normalizes NAPE-PLD expression. As a consequence, R-Flurbiprofen improves endogenous cannabinoid mediated effects, indicated by the reduction of glutamate release, increased activity of the anti-inflammatory transcription factor PPARγ and attenuation of microglia activation. Antinociceptive effects are lost by combined inhibition of CB1 and CB2 receptors and partially abolished in CB1 receptor deficient mice. R-flurbiprofen does however not cause changes of core body temperature which is a typical indicator of central effects of cannabinoid-1 receptor agonists. Conclusion Our results suggest that R-flurbiprofen improves the endogenous mechanisms to regain stability after axonal injury and to fend off chronic neuropathic pain by modulating the endocannabinoid system and thus constitutes an attractive, novel therapeutic agent in the treatment of chronic, intractable pain. PMID:20498712
Testing the equivalence of modern human cranial covariance structure: Implications for bioarchaeological applications.

PubMed

von Cramon-Taubadel, Noreen; Schroeder, Lauren

2016-10-01

Estimation of the variance-covariance (V/CV) structure of fragmentary bioarchaeological populations requires the use of proxy extant V/CV parameters. However, it is currently unclear whether extant human populations exhibit equivalent V/CV structures. Random skewers (RS) and hierarchical analyses of common principal components (CPC) were applied to a modern human cranial dataset. Cranial V/CV similarity was assessed globally for samples of individual populations (jackknifed method) and for pairwise population sample contrasts. The results were examined in light of potential explanatory factors for covariance difference, such as geographic region, among-group distance, and sample size. RS analyses showed that population samples exhibited highly correlated multivariate responses to selection, and that differences in RS results were primarily a consequence of differences in sample size. The CPC method yielded mixed results, depending upon the statistical criterion used to evaluate the hierarchy. The hypothesis-testing (step-up) approach was deemed problematic due to sensitivity to low statistical power and elevated Type I errors. In contrast, the model-fitting (lowest AIC) approach suggested that V/CV matrices were proportional and/or shared a large number of CPCs. Pairwise population sample CPC results were correlated with cranial distance, suggesting that population history explains some of the variability in V/CV structure among groups. The results indicate that patterns of covariance in human craniometric samples are broadly similar but not identical. These findings have important implications for choosing extant covariance matrices to use as proxy V/CV parameters in evolutionary analyses of past populations. © 2016 Wiley Periodicals, Inc.
M. leprae components induce nerve damage by complement activation: identification of lipoarabinomannan as the dominant complement activator.

PubMed

Bahia El Idrissi, Nawal; Das, Pranab K; Fluiter, Kees; Rosa, Patricia S; Vreijling, Jeroen; Troost, Dirk; Morgan, B Paul; Baas, Frank; Ramaglia, Valeria

2015-05-01

Peripheral nerve damage is the hallmark of leprosy pathology but its etiology is unclear. We previously identified the membrane attack complex (MAC) of the complement system as a key determinant of post-traumatic nerve damage and demonstrated that its inhibition is neuroprotective. Here, we determined the contribution of the MAC to nerve damage caused by Mycobacterium leprae and its components in mouse. Furthermore, we studied the association between MAC and the key M. leprae component lipoarabinomannan (LAM) in nerve biopsies of leprosy patients. Intraneural injections of M. leprae sonicate induced MAC deposition and pathological changes in the mouse nerve, whereas MAC inhibition preserved myelin and axons. Complement activation occurred mainly via the lectin pathway and the principal activator was LAM. In leprosy nerves, the extent of LAM and MAC immunoreactivity was robust and significantly higher in multibacillary compared to paucibacillary donors (p = 0.01 and p = 0.001, respectively), with a highly significant association between LAM and MAC in the diseased samples (r = 0.9601, p = 0.0001). Further, MAC co-localized with LAM on axons, pointing to a role for this M. leprae antigen in complement activation and nerve damage in leprosy. Our findings demonstrate that MAC contributes to nerve damage in a model of M. leprae-induced nerve injury and its inhibition is neuroprotective. In addition, our data identified LAM as the key pathogen associated molecule that activates complement and causes nerve damage. Taken together our data imply an important role of complement in nerve damage in leprosy and may inform the development of novel therapeutics for patients.
Ultrastructural organization of medial prefrontal inputs to the rhinal cortices.

PubMed

Apergis-Schoute, John; Pinto, Aline; Paré, Denis

2006-07-01

Accumulating evidence suggests that the medial prefrontal cortex (mPFC) plays a critical role in the formation, retrieval and long-term storage of hippocampal-dependent memories. Consistent with this, there are direct hippocampal projections to the mPFC. Moreover, the mPFC sends robust projections to the perirhinal and entorhinal cortices, two interconnected cortical fields that funnel information into and out of the hippocampus. However, the significance of the latter projection remains unclear because no data are available regarding the rhinal targets of mPFC axons. This question was examined in the present study using a combination of anterograde tracing with Phaseolus vulgaris leucoagglutinin and pre-embedding gamma-aminobutyric acid (GABA) immunocytochemistry in guinea pigs. Following Phaseolus vulgaris leucoagglutinin injections in the mPFC, anterogradely labeled axons were seen in the perirhinal (mainly superficial layers) and lateral entorhinal (mainly deep layers) cortices. In the electron microscope, the synaptic articulation of anterogradely labeled mPFC axon terminals with perirhinal and entorhinal neurons was found to be nearly identical. In these two rhinal fields, mPFC axon terminals only formed asymmetric synapses, typically with GABA-immunonegative spines ( approximately 70%) but occasionally with dendritic profiles ( approximately 30%), half of which were GABA immunopositive. In the light of earlier observations, these findings indicate that mPFC inputs exert mainly excitatory effects in the rhinal cortices, prevalently on principal neurons. Thus, these results suggest that the mPFC may affect hippocampal-dependent memories by enhancing impulse traffic into and out of the hippocampus at the level of the rhinal cortices.
Job characteristics, well-being and risky behaviour amongst pharmacists.

PubMed

Phipps, Denham L; Walshe, Kieran; Parker, Dianne; Noyce, Peter R; Ashcroft, Darren M

2016-12-01

Healthcare practitioners' fitness to practise has often been linked to their personal and demographic characteristics. It is possible that situational factors, such as the work environment and physical or psychological well-being, also have an influence on an individual's fitness to practise. However, it is unclear how these factors might be linked to behaviours that risk compromising fitness to practise. The aim of this study was to examine the association between job characteristics, well-being and behaviour reflecting risky practice amongst a sample of registered pharmacists in a region of the United Kingdom. Data were obtained from a cross-sectional self-report survey of 517 pharmacists. These data were subjected to principal component analysis and path analysis, with job characteristics (demand, autonomy and feedback) and well-being (distress and perceived competence) as the predictors and behaviour as the outcome variable. Two aspects of behaviour were found: Overloading (taking on more work than one can comfortably manage) and risk taking (working at or beyond boundaries of safe practice). Separate path models including either job characteristics or well-being as independent variables provided a good fit to the data-set. Of the job characteristics, demand had the strongest association with behaviour, while the association between well-being and risky behaviour differed according to the aspect of behaviour being assessed. The findings suggest that, in general terms, situational factors should be considered alongside personal factors when assessing, judging or remediating fitness to practise. They also suggest the presence of different facets to the relationship between job characteristics, well-being and risky behaviour amongst pharmacists.
Frontal Gamma-Aminobutyric Acid Concentrations Are Associated With Cognitive Performance in Older Adults

PubMed Central

Porges, Eric C.; Woods, Adam J.; Edden, Richard A.E.; Puts, Nicolaas A.J.; Harris, Ashley D.; Chen, Huaihou; Garcia, Amanda M.; Seider, Talia R.; Lamb, Damon G.; Williamson, John B.; Cohen, Ronald A.

2017-01-01

BACKGROUND Gamma-aminobutyric acid (GABA), the brain’s principal inhibitory neurotransmitter, has been associated with perceptual and attentional functioning. Recent application of magnetic resonance spectroscopy (MRS) provides in vivo evidence for decreasing GABA concentrations during adulthood. It is unclear, however, how age-related decrements in cerebral GABA concentrations contribute to cognitive decline, or whether previously reported declines in cerebral GABA concentrations persist during healthy aging. We hypothesized that participants with higher GABA concentrations in the frontal cortex would exhibit superior cognitive function and that previously reported age-related decreases in cortical GABA concentrations continue into old age. METHODS We measured GABA concentrations in frontal and posterior midline cerebral regions using a Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) 1H-MRS approach in 94 older adults without history or clinical evidence of mild cognitive impairment or dementia (mean age, 73 years). We administered the Montreal Cognitive Assessment to assess cognitive functioning. RESULTS Greater frontal GABA concentrations were associated with superior cognitive performance. This relation remained significant after controlling for age, years of education, and brain atrophy. GABA concentrations in both frontal and posterior regions decreased as a function of age. CONCLUSIONS These novel findings from a large, healthy, older population indicate that cognitive function is sensitive to cerebral GABA concentrations in the frontal cortex, and GABA concentration in frontal and posterior regions continue to decline in later age. These effects suggest that proton MRS may provide a clinically useful method for the assessment of normal and abnormal age-related cognitive changes and the associated physiological contributors. PMID:28217759
Efficacy of Intensive Control of Glucose in Stroke Prevention: A Meta-Analysis of Data from 59197 Participants in 9 Randomized Controlled Trials

PubMed Central

Zhang, Chi; Zhou, Yu-Hao; Xu, Chun-Li; Chi, Feng-Ling; Ju, Hai-Ning

2013-01-01

Background The efficacy of treatments that lower glucose in reducing the risk of incident stroke remains unclear. We therefore did a systematic review and meta-analysis to evaluate the efficacy of intensive control of glucose in the prevention of stroke. Methodology/Principal Findings We systematically searched Medline, EmBase, and the Cochrane Library for trials published between 1950 and June, 2012. We included randomized controlled trials that reported on the effects of intensive control of glucose on incident stroke compared with standard care. Summary estimates of relative risk (RR) reductions were calculated with a random effects model, and the analysis was further stratified by factors that could affect the treatment effects. Of 649 identified studies, we included nine relevant trials, which provided data for 59197 patients and 2037 events of stroke. Overall, intensive control of glucose as compared to standard care had no effect on incident stroke (RR, 0.96; 95%CI 0.88–1.06; P = 0.445). In the stratified analyses, a beneficial effect was seen in those trials when body mass index (BMI) more than 30 (RR, 0.86; 95%CI: 0.75–0.99; P = 0.041). No other significant differences were detected between the effect of intensive control of glucose and standard care when based on other subset factors. Conclusions/Significance Our study indicated intensive control of glucose can effectively reduce the risk of incident stroke when patients with BMI more than 30. PMID:23372729
Fragmentation of contaminant and endogenous DNA in ancient samples determined by shotgun sequencing; prospects for human palaeogenomics.

PubMed

García-Garcerà, Marc; Gigli, Elena; Sanchez-Quinto, Federico; Ramirez, Oscar; Calafell, Francesc; Civit, Sergi; Lalueza-Fox, Carles

2011-01-01

Despite the successful retrieval of genomes from past remains, the prospects for human palaeogenomics remain unclear because of the difficulty of distinguishing contaminant from endogenous DNA sequences. Previous sequence data generated on high-throughput sequencing platforms indicate that fragmentation of ancient DNA sequences is a characteristic trait primarily arising due to depurination processes that create abasic sites leading to DNA breaks. METHODOLOGY/PRINCIPALS FINDINGS: To investigate whether this pattern is present in ancient remains from a temperate environment, we have 454-FLX pyrosequenced different samples dated between 5,500 and 49,000 years ago: a bone from an extinct goat (Myotragus balearicus) that was treated with a depurinating agent (bleach), an Iberian lynx bone not subjected to any treatment, a human Neolithic sample from Barcelona (Spain), and a Neandertal sample from the El Sidrón site (Asturias, Spain). The efficiency of retrieval of endogenous sequences is below 1% in all cases. We have used the non-human samples to identify human sequences (0.35 and 1.4%, respectively), that we positively know are contaminants. We observed that bleach treatment appears to create a depurination-associated fragmentation pattern in resulting contaminant sequences that is indistinguishable from previously described endogenous sequences. Furthermore, the nucleotide composition pattern observed in 5' and 3' ends of contaminant sequences is much more complex than the flat pattern previously described in some Neandertal contaminants. Although much research on samples with known contaminant histories is needed, our results suggest that endogenous and contaminant sequences cannot be distinguished by the fragmentation pattern alone.
Dimensionality reduction of collective motion by principal manifolds

NASA Astrophysics Data System (ADS)

Gajamannage, Kelum; Butail, Sachit; Porfiri, Maurizio; Bollt, Erik M.

2015-01-01

While the existence of low-dimensional embedding manifolds has been shown in patterns of collective motion, the current battery of nonlinear dimensionality reduction methods is not amenable to the analysis of such manifolds. This is mainly due to the necessary spectral decomposition step, which limits control over the mapping from the original high-dimensional space to the embedding space. Here, we propose an alternative approach that demands a two-dimensional embedding which topologically summarizes the high-dimensional data. In this sense, our approach is closely related to the construction of one-dimensional principal curves that minimize orthogonal error to data points subject to smoothness constraints. Specifically, we construct a two-dimensional principal manifold directly in the high-dimensional space using cubic smoothing splines, and define the embedding coordinates in terms of geodesic distances. Thus, the mapping from the high-dimensional data to the manifold is defined in terms of local coordinates. Through representative examples, we show that compared to existing nonlinear dimensionality reduction methods, the principal manifold retains the original structure even in noisy and sparse datasets. The principal manifold finding algorithm is applied to configurations obtained from a dynamical system of multiple agents simulating a complex maneuver called predator mobbing, and the resulting two-dimensional embedding is compared with that of a well-established nonlinear dimensionality reduction method.
Principal component analysis for protein folding dynamics.

PubMed

Maisuradze, Gia G; Liwo, Adam; Scheraga, Harold A

2009-01-09

Protein folding is considered here by studying the dynamics of the folding of the triple beta-strand WW domain from the Formin-binding protein 28. Starting from the unfolded state and ending either in the native or nonnative conformational states, trajectories are generated with the coarse-grained united residue (UNRES) force field. The effectiveness of principal components analysis (PCA), an already established mathematical technique for finding global, correlated motions in atomic simulations of proteins, is evaluated here for coarse-grained trajectories. The problems related to PCA and their solutions are discussed. The folding and nonfolding of proteins are examined with free-energy landscapes. Detailed analyses of many folding and nonfolding trajectories at different temperatures show that PCA is very efficient for characterizing the general folding and nonfolding features of proteins. It is shown that the first principal component captures and describes in detail the dynamics of a system. Anomalous diffusion in the folding/nonfolding dynamics is examined by the mean-square displacement (MSD) and the fractional diffusion and fractional kinetic equations. The collisionless (or ballistic) behavior of a polypeptide undergoing Brownian motion along the first few principal components is accounted for.

Online canteens: awareness, use, barriers to use, and the acceptability of potential online strategies to improve public health nutrition in primary schools.

PubMed

Wyse, Rebecca; Yoong, Sze Lin; Dodds, Pennie; Campbell, Libby; Delaney, Tessa; Nathan, Nicole; Janssen, Lisa; Reilly, Kathryn; Sutherland, Rachel; Wiggers, John; Wolfenden, Luke

2017-03-01

Issue addressed This study of primary school principals assessed the awareness, use, barriers to use and acceptability of online canteens. Methods A telephone survey of 123 primary school principals within the Hunter New England Region of New South Wales, Australia was conducted from September 2014 to November 2014. Results Fifty-six percent of principals were aware of the existence of online canteens, with 8% having implemented such a system, and 38% likely to do so in the future. Medium/large schools were more likely to be aware of or to use online canteens, however there were no differences in awareness or use in relation to school rurality or socioeconomic advantage. Principals cited parent internet access as the most commonly identified perceived barrier to online canteen use, and the majority of principals (71-93%) agreed that it would be acceptable to implement a range of consumer behaviour strategies via an online canteen. Conclusions Study findings suggest that despite relatively low levels of current use, online canteens have the potential to reach a large proportion of school communities in the future, across geographical and socioeconomic divides, and that the nutrition interventions which they have the capacity to deliver are considered acceptable to school principals. So what? Online canteens may represent an opportunity to deliver nutrition interventions to school communities. Future research should examine the feasibility and potential effectiveness of interventions delivered via this modality.
Florida's forests-2005 update

Treesearch

Mark J. Brown

2007-01-01

This bulletin highlights principal findings of an annual inventory of Florida's forests. Data summaries are based on measurements of 60 percent of the plots in the State. Additional data summaries and bulletins will be published as the remaining plots are measured.
Guinea Pig Guidelines.

ERIC Educational Resources Information Center

McQuillan, Patrick; Muncey, Donna

1991-01-01

When researchers want to scrutinize a school, the principal should get straight answers to questions concerning research focus and purpose, data collection methods, participants needed, school personnel's research roles, confidentiality protection, data analysis assistance, feedback, and participant access to findings. (MLH)
Principal regression analysis and the index leverage effect

NASA Astrophysics Data System (ADS)

Reigneron, Pierre-Alain; Allez, Romain; Bouchaud, Jean-Philippe

2011-09-01

We revisit the index leverage effect, that can be decomposed into a volatility effect and a correlation effect. We investigate the latter using a matrix regression analysis, that we call ‘Principal Regression Analysis' (PRA) and for which we provide some analytical (using Random Matrix Theory) and numerical benchmarks. We find that downward index trends increase the average correlation between stocks (as measured by the most negative eigenvalue of the conditional correlation matrix), and makes the market mode more uniform. Upward trends, on the other hand, also increase the average correlation between stocks but rotates the corresponding market mode away from uniformity. There are two time scales associated to these effects, a short one on the order of a month (20 trading days), and a longer time scale on the order of a year. We also find indications of a leverage effect for sectorial correlations as well, which reveals itself in the second and third mode of the PRA.
Principal agent relationships and the efficiency of hospitals.

PubMed

Ludwig, Martijn; Van Merode, Frits; Groot, Wim

2010-06-01

The efficiency of hospitals is an important political issue and has been the subject of a number of studies. Most studies find evidence for inefficiency but provide no theoretical explanations for differences in efficiency. This study used principal agent theory to explain differences in efficiency between hospitals. Two agency issues are examined: (1) quality of care in the relationship between hospital and patient, and (2) internal organisation, i.e. the relationship between the hospital and its main departments. It was found that efficiency and quality go together. This implies that the potential harmful information asymmetry between hospitals and patients does not appear to be a major problem, because increasing efficiency does not seem to reduce quality. Further, we find no relationship between the efficiency of departments and the efficiency of the entire hospital. The interest of hospital departments is currently not in line with the interests of the entire hospital.
Principal agent relationships and the efficiency of hospitals

PubMed Central

Ludwig, Martijn; Van Merode, Frits

2009-01-01

The efficiency of hospitals is an important political issue and has been the subject of a number of studies. Most studies find evidence for inefficiency but provide no theoretical explanations for differences in efficiency. This study used principal agent theory to explain differences in efficiency between hospitals. Two agency issues are examined: (1) quality of care in the relationship between hospital and patient, and (2) internal organisation, i.e. the relationship between the hospital and its main departments. It was found that efficiency and quality go together. This implies that the potential harmful information asymmetry between hospitals and patients does not appear to be a major problem, because increasing efficiency does not seem to reduce quality. Further, we find no relationship between the efficiency of departments and the efficiency of the entire hospital. The interest of hospital departments is currently not in line with the interests of the entire hospital. PMID:19655184
Glove-based approach to online signature verification.

PubMed

Kamel, Nidal S; Sayeed, Shohel; Ellis, Grant A

2008-06-01

Utilizing the multiple degrees of freedom offered by the data glove for each finger and the hand, a novel on-line signature verification system using the Singular Value Decomposition (SVD) numerical tool for signature classification and verification is presented. The proposed technique is based on the Singular Value Decomposition in finding r singular vectors sensing the maximal energy of glove data matrix A, called principal subspace, so the effective dimensionality of A can be reduced. Having modeled the data glove signature through its r-principal subspace, signature authentication is performed by finding the angles between the different subspaces. A demonstration of the data glove is presented as an effective high-bandwidth data entry device for signature verification. This SVD-based signature verification technique is tested and its performance is shown to be able to recognize forgery signatures with a false acceptance rate of less than 1.2%.
Development and initial evaluation of Transdiagnostic Behavior Therapy (TBT) for veterans with affective disorders.

PubMed

Gros, Daniel F

2014-12-15

Considerable attention has focused on the growing need for evidence-based psychotherapy for veterans with affective disorders within the Department of Veteran Affairs. Despite, and possibly due to, the large number of evidence-based protocols available, several obstacles remain in their widespread delivery within Veterans Affairs Medical Centers. In part as an effort to address these concerns, newer transdiagnostic approaches to psychotherapy have been developed to provide a single treatment that is capable of addressing several, related disorders. The goal of the present investigation was to develop and evaluate a transdiagnostic psychotherapy, Transdiagnostic Behavior Therapy (TBT), in veterans with affective disorders. Study 1 provided initial support for transdiagnostic presentation of evidence-based psychotherapy components in veterans with principal diagnoses of affective disorders (n=15). These findings were used to inform the development of the TBT protocol. In Study 2, an initial evaluation of TBT was completed in a second sample of veterans with principal diagnoses of affective disorders (n=29). The findings of Study 2 demonstrated significant improvements in symptoms of depression, anxiety, stress, posttraumatic stress, and related impairment across participants with various principal diagnoses. Together, the investigation provided preliminary support for effectiveness of TBT in veterans with affective disorders. Published by Elsevier Ireland Ltd.
Balanced feedforward inhibition and dominant recurrent inhibition in olfactory cortex

PubMed Central

Large, Adam M.; Vogler, Nathan W.; Mielo, Samantha; Oswald, Anne-Marie M.

2016-01-01

Throughout the brain, the recruitment of feedforward and recurrent inhibition shapes neural responses. However, disentangling the relative contributions of these often-overlapping cortical circuits is challenging. The piriform cortex provides an ideal system to address this issue because the interneurons responsible for feedforward and recurrent inhibition are anatomically segregated in layer (L) 1 and L2/3 respectively. Here we use a combination of optical and electrical activation of interneurons to profile the inhibitory input received by three classes of principal excitatory neuron in the anterior piriform cortex. In all classes, we find that L1 interneurons provide weaker inhibition than L2/3 interneurons. Nonetheless, feedforward inhibitory strength covaries with the amount of afferent excitation received by each class of principal neuron. In contrast, intracortical stimulation of L2/3 evokes strong inhibition that dominates recurrent excitation in all classes. Finally, we find that the relative contributions of feedforward and recurrent pathways differ between principal neuron classes. Specifically, L2 neurons receive more reliable afferent drive and less overall inhibition than L3 neurons. Alternatively, L3 neurons receive substantially more intracortical inhibition. These three features—balanced afferent drive, dominant recurrent inhibition, and differential recruitment by afferent vs. intracortical circuits, dependent on cell class—suggest mechanisms for olfactory processing that may extend to other sensory cortices. PMID:26858458
Education in a Changing Rural Environment: The Impact of Population and Economic Change on the Demand for and Costs of Public Education in Rural America. A Synthesis of Research Findings and an Identification of Important Policy Issues. SRDC Synthesis-Bibliography Series 18.

ERIC Educational Resources Information Center

Deaton, Brady J.; McNamara, Kevin T.

A synthesis of research findings addressing effects of population and economic changes on education supply and demand in rural communities also presents policy implications, to help with local decision making. Principal research findings listed include: lack of a statistical relationship between per pupil expenditures and achievement on…
Lipid-Derived Biofuels: Determination of Factors that Control Triglyceride Accumulation in Microalgae

DTIC Science & Technology

2012-10-30

Accumulation in Microalgae Principal Investigator Dr. K.E. Cooksey Department of Microbiology 109 Lewis Hall Montana State University...cultures to find the extent to which previously published results can be considered general for microalgae . Task 2. Quantify growth kinetics and...diatoms cultures to find the extent to which previous results can be found to be general for microalgae . Before this project, detailed
Computational methods for vortex dominated compressible flows

NASA Technical Reports Server (NTRS)

Murman, Earll M.

1987-01-01

The principal objectives were to: understand the mechanisms by which Euler equation computations model leading edge vortex flows; understand the vortical and shock wave structures that may exist for different wing shapes, angles of incidence, and Mach numbers; and compare calculations with experiments in order to ascertain the limitations and advantages of Euler equation models. The initial approach utilized the cell centered finite volume Jameson scheme. The final calculation utilized a cell vertex finite volume method on an unstructured grid. Both methods used Runge-Kutta four stage schemes for integrating the equations. The principal findings are briefly summarized.
Age-Related Differences in the Rate, Timing, and Diagnosis of 30-Day Readmissions in Hospitalized Adults With Asthma Exacerbation.

PubMed

Hasegawa, Kohei; Gibo, Koichiro; Tsugawa, Yusuke; Shimada, Yuichi J; Camargo, Carlos A

2016-04-01

Reducing hospital readmissions has attracted attention from many stakeholders. However, the characteristics of 30-day readmissions after asthma-related hospital admissions in adults are not known. It is also unclear whether older adults are at higher risk of 30-day readmission. To investigate the rate, timing, and principal diagnosis of 30-day readmissions in adults with asthma and to determine age-related differences. Retrospective cohort study of adults hospitalized for asthma exacerbation using the population-based inpatient samples of three states (California, Florida, and Nebraska) from 2005 through 2011. Patients were categorized into three age groups: younger (18-39 years), middle aged (40-64 years), and older (≥ 65 years) adults. Outcomes were 30-day all-cause readmission rate, timing, and principal diagnosis of readmission. Of 301,164 asthma-related admissions at risk for 30-day readmission, readmission rate was 14.5%. Compared with younger adults, older adults had significantly higher readmission rates (10.1% vs 16.5%; OR, 2.15 [95% CI, 2.07-2.23]; P < .001). The higher rate attenuated with adjustment (OR, 1.19 [95% CI, 1.13-1.26]; P < .001), indicating that most of the age-related difference is explained by sociodemographics and comorbidities. For all age groups, readmission rate was highest in the first week after discharge and declined thereafter. Overall, only 47.1% of readmissions were assigned respiratory diagnoses (asthma, COPD, pneumonia, and respiratory failure). Older adults were more likely to present with nonrespiratory diagnoses (41.7% vs 53.8%; P < .001). After asthma-related admission, 14.5% of patients had 30-day readmission with wide range of principal diagnoses. Compared with younger adults, older adults had higher 30-day readmission rates and proportions of nonrespiratory diagnoses. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
Development of L2 Word-Meaning Inference while Reading

ERIC Educational Resources Information Center

Hamada, Megumi

2009-01-01

Ability to infer the meaning of unknown words encountered while reading plays an important role in learners' L2 word-knowledge development. Despite numerous findings reported on word-meaning inference, how learners develop this ability is still unclear. In order to provide a developmental inquiry into L2 word-meaning inference while reading, this…
Hyperserotonemia in Adults with Autistic Disorder

ERIC Educational Resources Information Center

Hranilovic, Dubravka; Bujas-Petkovic, Zorana; Vragovic, Renata; Vuk, Tomislav; Hock, Karlo; Jernej, Branimir

2007-01-01

Hyperserotonemia is the most consistent serotonin-related finding in autism. The basis of this phenomenon, and its relationship to the central serotonergic dysfunction remains unclear. Platelet serotonin level (PSL) in 53 autistic adults and 45 healthy controls was measured. Mean PSL in autistic group (75.7 [plus or minus] 37.4 ng/[microliters])…
Disentangling the Effects of Student Attitudes and Behaviors on Academic Performance

ERIC Educational Resources Information Center

Janssen, Susan; O'Brien, Maureen

2014-01-01

The interplay among motivation, ability, attitudes, behaviors, homework, and learning is unclear from previous research. We analyze data collected from 687 students enrolled in seven economics courses. A model explaining homework and exam scores is estimated, and separate analyses of ability and motivation groups are conducted. We find that…
Finding Common Ground: Identifying and Eliciting Metacognition in ePortfolios across Contexts

ERIC Educational Resources Information Center

Bokser, Julie A.; Brown, Sarah; Chaden, Caryn; Moore, Michael; Cleary, Michelle Navarre; Reed, Susan; Seifert, Eileen; Zecker, Liliana Barro; Wozniak, Kathryn

2016-01-01

Research has suggested ePortfolios reveal and support students' metacognition, that is, their awareness, tracking, and evaluation of their learning over time. However, due to the wide variety of purposes and audiences for ePortfolios, it has been unclear whether there might be common criteria for identifying and assessing metacognition in…
Motor Abilities in Autism: A Review Using a Computational Context

ERIC Educational Resources Information Center

Gowen, Emma; Hamilton, Antonia

2013-01-01

Altered motor behaviour is commonly reported in Autism Spectrum Disorder, but the aetiology remains unclear. Here, we have taken a computational approach in order to break down motor control into different components and review the functioning of each process. Our findings suggest abnormalities in two areas--poor integration of information for…
Lack of Association of Handedness with Inattention and Hyperactivity Symptoms in ADHD

ERIC Educational Resources Information Center

Ghanizadeh, Ahmad

2013-01-01

Objective: Findings about the association of left-handedness and ADHD are inconsistent. While abnormal brain laterality is reported in children with ADHD, it is unclear if hand preference is associated with ADHD, severity symptoms, age, gender, comorbid psychiatric problems, or parental characteristics. Method: Subjects were 520 boys and girls…
Factors Affecting the Processing of Intensity in School-Aged Children

ERIC Educational Resources Information Center

Buss, Emily; Hall, Joseph W., III; Grose, John H.

2013-01-01

Purpose: Thresholds of school-aged children are elevated relative to those of adults for intensity discrimination and amplitude modulation (AM) detection. It is unclear how these findings are related or what role stimulus gating and dynamic envelope cues play in these results. Two experiments assessed the development of sensitivity to intensity…

Stuttering, Emotions, and Heart Rate during Anticipatory Anxiety: A Critical Review

ERIC Educational Resources Information Center

Alm, Per A.

2004-01-01

Persons who stutter often report their stuttering is influenced by emotional reactions, yet the nature of such relation is still unclear. Psychophysiological studies of stuttering have failed to find any major association between stuttering and the activity of the sympathetic nervous system. A review of published studies of heart rate in relation…
The Shades of Grey of Cyberbullying in Australian Schools

ERIC Educational Resources Information Center

Goff, Wendy

2011-01-01

This article explores the effects of cyberbullying in relation to a school's duty of care. By examining the impact of cyberbullying through an increasingly common scenario, it becomes apparent that the strategies for Australian schools in maintaining their duty of care may be unclear and uncommunicated. Findings suggest that Australian law in its…
What's in a Disruptive Disorder? Temperamental Antecedents of Oppositional Defiant Disorder: Findings from the Avon Longitudinal Study

ERIC Educational Resources Information Center

Stringaris, Argyris; Maughan, Barbara; Goodman, Robert

2010-01-01

Objective: Oppositional defiant disorder (ODD) is classified as a disruptive disorder, but shows a wide range of associations with other psychopathology, including internalizing problems. The reasons for these associations are unclear. Here we test the hypothesis that two distinct early temperamental precursors--emotionality and activity--underlie…
Quantitative Differences Between the First and Second Injection of Contrast Agent in Contrast-Enhanced Ultrasonography of Feline Kidneys and Spleen.

PubMed

Stock, Emmelie; Vanderperren, Katrien; Haers, Hendrik; Duchateau, Luc; Hesta, Myriam; Saunders, Jimmy H

2017-02-01

Contrast-enhanced ultrasound is a valuable and safe technique for the evaluation of organ perfusion. Repeated injections of ultrasound contrast agent are often administered during the same imaging session. However, it remains unclear if quantitative differences are present between the consecutive microbubble injections. Therefore, the first and second injection of contrast agent for the left renal cortex, renal medulla and the splenic parenchyma in healthy cats were compared. A lower peak intensity and area under the curve were observed for the first injection of contrast agent in the feline kidney, both for the renal cortex and medulla, and spleen. Moreover, for the renal cortex, the time-intensity curve was steeper after the second injection. Findings from the present study demonstrate that a second injection of contrast agent provides stronger enhancement. The exact mechanism behind our findings remains unclear; however, saturation of the lung macrophages is believed to play an important role. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
Explaining the Behavioral Intention towards BI Implementation in Public Administrations - A Principal-Agent Theory Approach

NASA Astrophysics Data System (ADS)

Becker, Jörg; Bergener, Philipp; Lis, Łukasz; Niehaves, Björn

Business Intelligence (BI) is an established instrument to support public administrations in their management tasks by increasing their information level. BI is of special interest in the context of introducing accrual accounting in public administrations as this affects the information level of different stakeholders, leading to a possible decrease for municipal councils. The principal-agent theory can help to explain different behavioral intentions of the stakeholders concerning the introduction of BI. We employ a single qualitative case study to analyze these behavioral intentions. It shows that the introduction of accrual accounting did decrease the information level of the municipal council making the principal-agent problems possible. Furthermore, it shows that BI might be a solution for this problem. Therefore, council members show the behavioral intention to support the BI implementation while administration staff members rather resist it. Based on these finding, we discuss implications for practice and future research.
Revenue Share between Layers and Investment Incentive for ISP in the Internet Market

NASA Astrophysics Data System (ADS)

Unno, Masaru; Xu, Hua

In this paper, we consider a revenue-sharing and network investment problem between an Internet service provider (ISP) and a content provider (CP) by applying the dynamic agency theory. We formulate the problem as the principal-agent problem where the ISP is the principal and the CP is the agent. The principal-agent problem is transformed to a stochastic optimal control problem in which the objectives of ISP are to find an optimal revenue-sharing strategy and a network investment strategy, and to advise an incentive compatible effort level to the CP. The sufficient conditions for the existence of the optimal revenue-sharing strategy, the optimal investment strategy and the incentive compatible effort to the CP are obtained. A numerical example is solved to show the existence of such strategies. The practical implications of the results obtained in the paper will also be discussed.
2001 mariner survey : principal findings

DOT National Transportation Integrated Search

2001-08-01

The 2001 Mariner Survey was a concentrated effort to get feedback on key readiness issues using a sample of 10,000 : merchant mariners from a population of approximately 104,000 qualified to serve on large ocean-going vessels. One : hundred and forty...
Forest resources of Tennessee - 1972

Treesearch

Paul A. Murphy

1972-01-01

This report states the principal findings of a new forest survey of Tennessee. Data for growth and cut are given for 1970, and the inventory is reported for January 1, 1971. A canvass of forest products output in 1970 also contributed information.
Forest resources of Alabama

Treesearch

William H. McWilliams

1992-01-01

The principal findings of the sixth forest inventory of Alabama (1990) and changes that have occurred since earlier inventories are presented in this report. Topics include the status and trends in forest area, biomass, timber volume, growth, removals, mortality, and timber products output.
Forest resources of Arkansas

Treesearch

Roy C. Beltz; Daniel F. Bertelson; Joanne L. Faulkner; Dennis M. May

1992-01-01

The principal findings of the sixth forest survey of Arkansas (1988) and changes that have occurred since earlier surveys are presented in this report. Topics examined include the status and trends in forest area, timber volume, growth, removals, mortality, and timber products output.
Target-Selectivity of Parvalbumin-Positive Interneurons in Layer II of Medial Entorhinal Cortex in Normal and Epileptic Animals

PubMed Central

Armstrong, Caren; Wang, Jessica; Lee, Soo Yeun; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2015-01-01

The medial entorhinal cortex layer II (MEClayerII) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII. However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII. However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII. Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals. PMID:26663222
Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.

PubMed

Armstrong, Caren; Wang, Jessica; Yeun Lee, Soo; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2016-06-01

The medial entorhinal cortex layer II (MEClayerII ) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII . However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII . However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII . Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
2002 mariner survey : principal findings

DOT National Transportation Integrated Search

2003-06-01

The 2002 Mariner Survey is a follow-up to the first survey of merchant : mariners conducted during 2001. The major focus of the 2002 : survey effort was to update and expand information on key readiness : and training issues. Of those who completed a...
CCR Careers | Center for Cancer Research

Cancer.gov

Be part of our mission to make breakthrough scientific discoveries to find cures and treatments for cancer. Our principal investigators lead teams of laboratory scientists, trainees, clinicians, and administrators to unlock scientific knowledge to advance the fight against cancer and HIV/AIDS.
Forest resources of Mississippi - 1989

Treesearch

John F. Kelly; Mike Sims

1989-01-01

The principal findings of the sixth forest survey of Mississippi (1987) and changes that have occurred since earlier surveys are presented in this report. Topics examined include the status and trends in forest area, timber volume, growth, removals, mortality, and timber product output.
Timber resources of East Oklahoma

Treesearch

Richard A. Birdsey; Dennis M. May

1988-01-01

Presents the principal findings of the fifth forest survey of east Oklahoma and the changes that have occurred since earlier surveys. Trends in forest area, ownership, forest type, stand structure, stocking, timber volume, growth, removals, mortality, management opportunities, and timber products output are discussed.
Forest resources of Mississippi - 1994

Treesearch

James F. Rosson

2001-01-01

The principal findings of the seventh forest survey of Mississippi and changes that have occurred since the previous survey are presented. Topics examined include forest area, ownership, forest-type groups, stand structure, basal area, timber volume, growth, removals, mortality, harvesting, and management activity.
Forest resources of Tennessee - 1991

Treesearch

Dennis M. May

1991-01-01

The principal findings of the fifth forest survey of Tennessee (1989) and changes that have occurred since earlier surveys are presented in the report. Topics examined include the status and trends in forest area, timber volume, growth, removals, mortality, and timber-product output.
Forest resources of Arkansas, 1995

Treesearch

James F. Rosson

2002-01-01

The principal findings of the seventh forest survey of Arkansas and changes that have occurred since the previous survey are presented. Topics examined include forest area, ownership, forest-type groups, stand structure, basal area, timber volume, growth, removals, mortality, harvesting, and management activity.
Teacher Ratings from Incomplete Student Ranking Data.

ERIC Educational Resources Information Center

Kaiser, Henry F.; Cerny, Barbara A.

1979-01-01

A method for obtaining teacher ratings from incomplete student ranking data is presented. The procedure involves finding the scores for the teachers on the first principal component of a student intercorrelation matrix, where the missing data are supplied by least squares. (Author)

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