Inflation with a constant rate of roll

NASA Astrophysics Data System (ADS)

Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi

2015-09-01

We consider an inflationary scenario where the rate of inflaton roll defined by ̈phi/H dot phi remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.

Terahertz Bandpass Frequency Selective Surfaces on Glass Substrates Using a Wet Micromachining Process

NASA Astrophysics Data System (ADS)

Ramzan, Mehrab; Khan, Talha Masood; Bolat, Sami; Nebioglu, Mehmet Ali; Altan, Hakan; Okyay, Ali Kemal; Topalli, Kagan

2017-08-01

This paper presents terahertz (THz) frequency selective surfaces (FSS) implemented on glass substrate using standard microfabrication techniques. These FSS structures are designed for frequencies around 0.8 THz. A fabrication process is proposed where a 100-μm-thick glass substrate is formed through the HF etching of a standard 500-μm-thick low cost glass wafer. Using this fabrication process, three separate robust designs consisting of single-layer FSS are investigated using high-frequency structural simulator (HFSS). Based on the simulation results, the first design consists of a circular ring slot in a square metallic structure on top of a 100-μm-thick Pyrex glass substrate with 70% transmission bandwidth of approximately 0.07 THz, which remains nearly constant till 30° angle of incidence. The second design consists of a tripole structure on top of a 100-μm-thick Pyrex glass substrate with 65% transmission bandwidth of 0.035 THz, which remains nearly constant till 30° angle of incidence. The third structure consists of a triangular ring slot in a square metal on top of a 100-μm-thick Pyrex glass substrate with 70% transmission bandwidth of 0.051 THz, which remains nearly constant up to 20° angle of incidence. These designs show that the reflections from samples can be reduced compared to the conventional sample holders used in THz spectroscopy applications, by using single layer FSS structures manufactured through a relatively simple fabrication process. Practically, these structures are achieved on a fabricated 285-μm-thick glass substrate. Taking into account the losses and discrepancies in the substrate thickness, the measured results are in good agreement with the electromagnetic simulations.

Factors influencing how senior nurses and midwives acquire and integrate coaching skills into routine practice: a grounded theory study.

PubMed

Rafferty, Rae; Fairbrother, Greg

2015-06-01

To introduce a theory which describes the process of and explicates the factors moderating, the acquisition and integration of leadership coaching skills into the routine practice of senior nurses and midwives. Organizations invest significant resources in leadership coaching programs to ensure that coaching is embedded as a core function of the manager's role. However, even after training, many managers remain unable to undertake this role successfully. The process by which health professionals translate 'manager as coach' training into successful practice outcomes, has remained largely unexplored. A grounded theory study design. Data, collected between February 2012-May 2013, included in-depth interviews with 20 senior nurses and midwives who had attended a leadership coaching program and analysis of nine reflective practice journals. Multiple researchers coded and analysed the data using constant comparative techniques. The outcomes of coaching training ranged from inappropriate use of the coaching skills through to transformed managerial practice. These outcomes were influenced by the dynamic interaction of three central domains of the emergent theoretical model: pre-existing individual perceptions, program elements and contemporaneous experiences. Interactions occurred within the domains and between them, impacting on activators such as courage, motivation, commitment and confidence. The study offers new insights into how senior nurses and midwives acquire and integrate coaching skills into their routine practice. The process is described as multifactorial and dynamic and has implications for the training design, delivery and organizational support of future leadership coaching programs. © 2015 John Wiley & Sons Ltd.

Inflation with a constant rate of roll

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

Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi, E-mail: motohashi@kicp.uchicago.edu, E-mail: alstar@landau.ac.ru, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp

2015-09-01

We consider an inflationary scenario where the rate of inflaton roll defined by {sup ··}φ/H φ-dot remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs formore » unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.« less

Solving the "Personhood Jigsaw Puzzle" in Residential Care Homes for the Elderly in the Hong Kong Chinese Context.

PubMed

Kong, Sui-Ting; Fang, Christine Meng-Sang; Lou, Vivian W Q

2017-02-01

End-of-life care studies on the nature of personhood are bourgeoning; however, the practices utilized for achieving personhood in end-of-life care, particularly in a cultural context in which interdependent being and collectivism prevail, remain underexplored. This study seeks to examine and conceptualize good practices for achieving the personhood of the dying elderly in residential care homes in a Chinese context. Twelve interviews were conducted with both medical and social care practitioners in four care homes to collect narratives of practitioners' practices. Those narratives were utilized to develop an "end-of-life case graph." Constant comparative analysis led to an understanding of the practice processes, giving rise to a process model of "solving the personhood jigsaw puzzle" that includes "understanding the person-in-relationship and person-in-time," "identifying the personhood-inhibiting experiences," and "enabling personalized care for enhanced psychosocial outcomes." Findings show how the "relational personhood" of the elderly can be maintained when physical deterioration and even death are inevitable.

The Effect of Variability of Practice at Execution Redundancy Level in Skilled and Novice Basketball Players.

PubMed

Taheri, Hamidreza; Fazeli, Davoud; Poureghbali, Sogand

2017-04-01

We investigated the effect of practice variability through execution redundancy in skilled and novice basketball players on free throw skills. Twelve skilled basketball players and 12 novices (mean age = 25.4 years, SD = 4.3) were divided into four groups (skilled constant, skilled variable, novice constant, and novice variable). After a pretest, participants practiced free throw action. The variable groups threw the ball over an obstacle of varying heights on each trial in random order, whereas the obstacle's height was fixed for the constant groups. After 7 and 14 consecutive days of practice, participants performed two posttests with constant and variable distances from the basket. The results showed that practicing different solutions of a task did not affect the performance of skilled players but had an immediate negative effect on the performance of novice players. Learning a complex task is the result of learning task-related parameters, and practice variability can create a mismatch between task difficulty and new learner skill levels.

Growth Structure and Properties of Gradient Nanocrystalline Coatings of the Ti-Al-Si-Cu-N System

NASA Astrophysics Data System (ADS)

Ovchinnikov, S. V.; Pinzhin, Yu. P.

2016-10-01

Methods of electron microprobe analysis, X-ray structure analysis and electron microscopy were used to study the element composition and features of the structure-phase, elastic stress state of nanocrystalline coatings of the Ti- Al- Si- Cu- N system with gradient of copper concentration across their thickness. The authors established the effects of element composition modification, non-monotonous behavior of the lattice constant of alloyed nitride and rise in the bending-torsion value of the crystalline lattice in individual nanocrystals to values of around 400 degrees/μm with increase in copper concentration, whereas the sizes of alloyed nitride crystals remained practically unchanged. Mechanical (hardness), adhesion and tribological properties of coatings were examined. Comparative analysis demonstrates higher values of adhesion characteristics in the case of gradient coatings of the Ti- Al- Si- Cu- N system than in the case of single-layer (with constant element concentration) analogues.

Rail Brake System Using a Linear Induction Motor for Dynamic Braking

NASA Astrophysics Data System (ADS)

Sakamoto, Yasuaki; Kashiwagi, Takayuki; Tanaka, Minoru; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. In this paper, we estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system.

Transfer of motor learning engages specific neural substrates during motor memory consolidation dependent on the practice structure.

PubMed

Kantak, Shailesh S; Sullivan, Katherine J; Fisher, Beth E; Knowlton, Barbara J; Winstein, Carolee J

2011-01-01

The authors investigated how brain activity during motor-memory consolidation contributes to transfer of learning to novel versions of a motor skill following distinct practice structures. They used 1 Hz repetitive Transcranial Magnetic Stimulation (rTMS) immediately after constant or variable practice of an arm movement skill to interfere with primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC). The effect of interference was assessed through skill performance on two transfer targets: one within and one outside the range of practiced movement parameters for the variable practice group. For the control (no rTMS) group, variable practice benefited delayed transfer performance more than constant practice. The rTMS effect on delayed transfer performance differed for the two transfer targets. For the within-range target, rTMS interference had no significant affect on the delayed transfer after either practice structure. However, for the outside-range target, rTMS interference to DLPFC but not M1 attenuated delayed transfer benefit following variable practice. Additionally, for the outside-range target, rTMS interference to M1 but not DLPFC attenuated delayed transfer following constant practice. This suggests that variable practice may promote reliance on DLPFC for memory consolidation associated with outside-range transfer of learning, whereas constant practice may promote reliance on M1 for consolidation and long-term transfer.

Global Research Trends on Early-Life Feeding Practices and Early Childhood Caries: a Systematic Review

PubMed Central

Cheng, Ashley

2014-01-01

Objective Describe the epidemiologic literature related to early-life feeding practices and early childhood caries (ECC) with regard to publication attributes and trends in these attributes over time. Methods Systematic literature review including electronic and manual searches (in BIOSIS, CINAHL, Cochrane Library, LILACS, MEDLINE, Web of Science, and WHOLIS), covering the years 1990–2013. Attributes of publications meeting a priori inclusion criteria were abstracted and organized by global region and trends over time. Attributes included country of origin and study design of included publications and age and caries prevalence of the populations studied. Results 244 publications drawn from 196 independent study populations were included. The number of publications and the countries represented increased over time, although some world regions remained underrepresented. Most publications were cross sectional (75%); while this percentage remained fairly constant over time, the percentage of studies to account for confounding factors increased. Publications varied with respect to the caries experience and age range of children included in each study. Conclusions Publication productivity regarding feeding practices and ECC research has grown, but this growth has not been evenly distributed globally. Individual publication attributes (i.e. methods and context) can differ significantly and should be considered when interpreting and synthesizing the literature. PMID:25328911

[Effect of air-electric fields on driving and reaction patterns. Test subjects in the car driving simulator (author's transl)].

PubMed

Anselm, D; Danner, M; Kirmaier, N; König, H L; Müller-Limmroth, W; Reis, A; Schauerte, W

1977-06-10

In the relevant frequency range of about 10 Hertz cars can be considered very largely as Faraday cages and consequently as screens against air-electric fields. This may have a negative influence on driving and reaction patterns as a result. In an extensive investigation 48 subjects in a driving simulator were exposed to definite artificially produced air-electric fields. The self-rating of the performance and concentration of the subjects, reaction times and driving errors were determined. While the reaction times remained practically constant, the driving behavior of the subjects improved.

A code of ethics for evidence-based research with ancient human remains.

PubMed

Kreissl Lonfat, Bettina M; Kaufmann, Ina Maria; Rühli, Frank

2015-06-01

As clinical research constantly advances and the concept of evolution becomes a strong and influential part of basic medical research, the absence of a discourse that deals with the use of ancient human remains in evidence-based research is becoming unbearable. While topics such as exhibition and excavation of human remains are established ethical fields of discourse, when faced with instrumentalization of ancient human remains for research (i.e., ancient DNA extractions for disease marker analyses) the answers from traditional ethics or even more practical fields of bio-ethics or more specific biomedical ethics are rare to non-existent. The Centre for Evolutionary Medicine at the University of Zurich solved their needs for discursive action through the writing of a self-given code of ethics which was written in dialogue with the researchers at the Institute and was published online in Sept. 2011: http://evolutionäremedizin.ch/coe/. The philosophico-ethical basis for this a code of conduct and ethics and the methods are published in this article. © 2015 Wiley Periodicals, Inc.

Neural practice effect during cross-modal selective attention: Supra-modal and modality-specific effects.

PubMed

Xia, Jing; Zhang, Wei; Jiang, Yizhou; Li, You; Chen, Qi

2018-05-16

Practice and experiences gradually shape the central nervous system, from the synaptic level to large-scale neural networks. In natural multisensory environment, even when inundated by streams of information from multiple sensory modalities, our brain does not give equal weight to different modalities. Rather, visual information more frequently receives preferential processing and eventually dominates consciousness and behavior, i.e., visual dominance. It remains unknown, however, the supra-modal and modality-specific practice effect during cross-modal selective attention, and moreover whether the practice effect shows similar modality preferences as the visual dominance effect in the multisensory environment. To answer the above two questions, we adopted a cross-modal selective attention paradigm in conjunction with the hybrid fMRI design. Behaviorally, visual performance significantly improved while auditory performance remained constant with practice, indicating that visual attention more flexibly adapted behavior with practice than auditory attention. At the neural level, the practice effect was associated with decreasing neural activity in the frontoparietal executive network and increasing activity in the default mode network, which occurred independently of the modality attended, i.e., the supra-modal mechanisms. On the other hand, functional decoupling between the auditory and the visual system was observed with the progress of practice, which varied as a function of the modality attended. The auditory system was functionally decoupled with both the dorsal and ventral visual stream during auditory attention while was decoupled only with the ventral visual stream during visual attention. To efficiently suppress the irrelevant visual information with practice, auditory attention needs to additionally decouple the auditory system from the dorsal visual stream. The modality-specific mechanisms, together with the behavioral effect, thus support the visual dominance model in terms of the practice effect during cross-modal selective attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

A predictive nondestructive model for the covariation of tree height, diameter, and stem volume scaling relationships.

PubMed

Zhang, Zhongrui; Zhong, Quanlin; Niklas, Karl J; Cai, Liang; Yang, Yusheng; Cheng, Dongliang

2016-08-24

Metabolic scaling theory (MST) posits that the scaling exponents among plant height H, diameter D, and biomass M will covary across phyletically diverse species. However, the relationships between scaling exponents and normalization constants remain unclear. Therefore, we developed a predictive model for the covariation of H, D, and stem volume V scaling relationships and used data from Chinese fir (Cunninghamia lanceolata) in Jiangxi province, China to test it. As predicted by the model and supported by the data, normalization constants are positively correlated with their associated scaling exponents for D vs. V and H vs. V, whereas normalization constants are negatively correlated with the scaling exponents of H vs. D. The prediction model also yielded reliable estimations of V (mean absolute percentage error = 10.5 ± 0.32 SE across 12 model calibrated sites). These results (1) support a totally new covariation scaling model, (2) indicate that differences in stem volume scaling relationships at the intra-specific level are driven by anatomical or ecophysiological responses to site quality and/or management practices, and (3) provide an accurate non-destructive method for predicting Chinese fir stem volume.

Energy intake of rats fed a cafeteria diet.

PubMed

Prats, E; Monfar, M; Castellà, J; Iglesias, R; Alemany, M

1989-02-01

The proportion of lipid, carbohydrate and protein energy self-selected by male and female rats from a cafeteria diet has been studied for a 48-day period (36-day in female rats). The diet consisted in 12 different items and was offered daily, in excess and under otherwise standard conditions, to rats--caged in groups of three--from weaning to adulthood. Groups of control animals were studied in parallel and compared with the cafeteria groups. Cafeteria diet fed groups of rats ingested more energy and lowered their metabolic efficiency with age. Male rats ate more than females and increased their body weight even after female practically stopped growing. There was a wide variation in the aliments consumed each day by the cafeteria-fed rats. However, the proportion of lipid, protein and carbohydrate the rats ate remained constant. Male rats ingested more lipid than females. Carbohydrate consumption was constant in control and cafeteria fed groups of rats independently of sex. Protein consumption was higher in cafeteria rats than in controls, but the differences were not so important as with liquid. Fiber content of the cafeteria diet was lower than that of the control diet. The cafeteria diet selected by the rats was, thus, hypercaloric and hyperlipidic, with practically the same amount of carbohydrate than the control diet, slightly hyperproteic and, nevertheless, remarkably constant in its composition with respect to time. Cafeteria rats had a higher water intake than controls. All these trends were maintained despite the observed changes in the animals' tastes and their differential consumption of the ailments of the diet.

Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

PubMed

Simpson, Len Parker; Kordi, Mehdi

2017-07-01

Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.

Static properties of hydrostatic thrust gas bearings with curved surfaces.

NASA Technical Reports Server (NTRS)

Rehsteiner, F. H.; Cannon, R. H., Jr.

1971-01-01

The classical treatment of circular, hydrostatic, orifice-regulated thrust gas bearings, in which perfectly plane bearing plates are assumed, is extended to include axisymmetric, but otherwise arbitrary, plate profiles. Plate curvature has a strong influence on bearing load capability, static stiffness, tilting stiffness, and side force per unit misalignment angle. By a suitable combination of gas inlet impedance and concave plate profile, the static stiffness can be made almost constant over a wide load range, and to remain positive at the closure load. Extensive measurements performed with convex and concave plates agree with theory to within the experimental error throughout and demonstrate the practical feasibility of using curved plates.

Eliminating the "I hate you" in the supplier-purchasing relationship.

PubMed

Nelson, M

1996-05-01

Throughout time there has always been a supplier of some service or goods, and there has always been a purchaser of that service or goods. The one thing that has remained constant throughout that time is that they have an agreement not to like each other. This article will approach the subject in the "today" sense using current practical approaches that are used in all industries and will not deal with the relationships of the future. To cover this complex arena, the article will deal with four areas: (1) where we are now, (2) supplier-based concentration, (3) single sourcing, and (4) transportation techniques.

Staying theoretically sensitive when conducting grounded theory research.

PubMed

Reay, Gudrun; Bouchal, Shelley Raffin; A Rankin, James

2016-09-01

Background Grounded theory (GT) is founded on the premise that underlying social patterns can be discovered and conceptualised into theories. The method and need for theoretical sensitivity are best understood in the historical context in which GT was developed. Theoretical sensitivity entails entering the field with no preconceptions, so as to remain open to the data and the emerging theory. Investigators also read literature from other fields to understand various ways to construct theories. Aim To explore the concept of theoretical sensitivity from a classical GT perspective, and discuss the ontological and epistemological foundations of GT. Discussion Difficulties in remaining theoretically sensitive throughout research are discussed and illustrated with examples. Emergence - the idea that theory and substance will emerge from the process of comparing data - and staying open to the data are emphasised. Conclusion Understanding theoretical sensitivity as an underlying guiding principle of GT helps the researcher make sense of important concepts, such as delaying the literature review, emergence and the constant comparative method (simultaneous collection, coding and analysis of data). Implications for practice Theoretical sensitivity and adherence to the GT research method allow researchers to discover theories that can bridge the gap between theory and practice.

Ideology, psychiatric practice and professionalism.

PubMed

Bouras, N; Ikkos, G

2013-01-01

Psychiatry, associated as it is with social and cultural factors, has undergone profound changes over the last 50 years. Values, attitudes, beliefs and ideology all influence psychiatry. Deinstitutionalisation, the normalization principle, advocacy, empowerment and the recovery model are ideologies that have been closely associated with policy, service developments and clinical practice in psychiatry. A "new professionalism" is emerging as a consequence of a number of changes in mental health care that needs to be guided by the highest standards of care which are best epitomized in psychiatry as a social contract with society. Looking to the future it is important that the profession recognises the impact ideology can make, if it is not to remain constantly on the defensive. In order to engage proactively and effectively with ideology as well as clinical science and evidence based service development, psychiatry as a profession will do best to approach significant future policy, practice and service changes by adopting an ethical approach, as a form a social contract. Psychiatrists must pay increasing attention to understanding values as expressed by ideologies, working in a collaborative way with other mental health professionals, involve service users and manage systems as well as be competent in clinical assessment and treatment. Whether in time of plenty or in times of deprivation, ideology produces effects on practice and in the context of constantly changing knowledge and the current financial stress this is likely to be more the case (and not less) in the foreseeable future. Psychiatrists must take into consideration the new social problems seen in some high income countries with the increased availability of highly potent "street drugs", perceived threats from various immigrant and minority communities and breakdown of "social capital" such as the decline of the nuclear family.

Drug-Induced Liver Injury: Pattern Recognition and Future Directions

PubMed Central

Haque, Tanvir; Sasatomi, Eizaburo; Hayashi, Paul H.

2016-01-01

Drug-induced liver injury (DILI) remains a significant clinical challenge and is the leading cause of acute liver failure in most countries. An aging population that uses more medications, a constant influx of newly developed drugs and a growing risk from unfamiliar herbal and dietary supplements will make DILI an increasing part of clinical practice. Currently, the most effective strategy for disease management is rapid identification, withholding the inciting agents, supportive care and having a firm understanding of the expected natural history. There are resources available to aid the clinician, including a new online “textbook” as well as causality assessment tools, but a heightened awareness of risk and the disease’s varying phenotypes and good history-taking remain cornerstones to diagnosis. Looking ahead, growing registries of cases, pharmacoepidemiology studies and translational research into the mechanisms of injury may produce better diagnostic tools, markers for risk and disease, and prevention and therapeutics. PMID:26696029

Declining incidence of chickenpox in the absence of universal childhood immunisation

PubMed Central

Lowe, G; Salmon, R; Thomas, D; Evans, M

2004-01-01

Objective: To examine the epidemiology of chickenpox in Wales from 1986 to 2001. Design: Descriptive analysis of chickenpox consultations reported by the Welsh general practice sentinel surveillance scheme for infectious diseases, compared with annual shingles consultation rates from the same scheme to exclude reporting fatigue and data from a general practice morbidity database to validate results. Setting: A total of 226 884 patients registered with one of 30 volunteer general practices participating in the sentinel surveillance scheme. Main outcome measures: Age standardised and age specific incidence of chickenpox. Results: Crude and age standardised consultation rates for chickenpox declined from 1986 to 2001, with loss of epidemic cycling. Rates remained stable in 0–4 year olds but declined in all older age groups, particularly those aged 5–14 years. Shingles consultation rates remained constant over the same period. Data from the morbidity database displayed similar trends. Conclusion: General practitioner consultation rates for chickenpox are declining in Wales except in pre-school children. These findings are unlikely to be a reporting artefact but may be explained either by an overall decline in transmission or increased social mixing in those under 5 years old, through formal child care and earlier school entry, and associated increasing rates of mild or subclinical infection in this age group. Further investigation, particularly by serological surveillance, is necessary before universal varicella immunisation can be considered in the UK. PMID:15383443

Effects of water management practices on residue decomposition and degradation of Cry1Ac protein from crop-wild Bt rice hybrids and parental lines during winter fallow season.

PubMed

Xiao, Manqiu; Dong, Shanshan; Li, Zhaolei; Tang, Xu; Chen, Yi; Yang, Shengmao; Wu, Chunyan; Ouyang, Dongxin; Fang, Changming; Song, Zhiping

2015-12-01

Rice is the staple diet of over half of the world's population and Bacillus thuringiensis (Bt) rice expressing insecticidal Cry proteins is ready for deployment. An assessment of the potential impact of Bt rice on the soil ecosystem under varied field management practices is urgently required. We used litter bags to assess the residue (leaves, stems and roots) decomposition dynamics of two transgenic rice lines (Kefeng6 and Kefeng8) containing stacked genes from Bt and sck (a modified CpTI gene encoding a cowpea trypsin inhibitor) (Bt/CpTI), a non-transgenic rice near-isoline (Minghui86), wild rice (Oryza rufipogon) and crop-wild Bt rice hybrid under contrasting conditions (drainage or continuous flooding) in the field. No significant difference was detected in the remaining mass, total C and total N among cultivars under aerobic conditions, whereas significant differences in the remaining mass and total C were detected between Kefeng6 and Kefeng8 and Minghui86 under the flooded condition. A higher decomposition rate constant (km) was measured under the flooded condition compared with the aerobic condition for leaf residues, whereas the reverse was observed for root residues. The enzyme-linked immunosorbent assay (ELISA), which was used to monitor the changes in the Cry1Ac protein in Bt rice residues, indicated that (1) the degradation of the Cry1Ac protein under both conditions best fit first-order kinetics, and the predicted DT50 (50% degradation time) of the Cry1Ac protein ranged from 3.6 to 32.5 days; (2) the Cry1Ac protein in the residue degraded relatively faster under aerobic conditions; and (3) by the end of the study (~154 days), the protein was present at a low concentration in the remaining residues under both conditions. The degradation rate constant was negatively correlated with the initial carbon content and positively correlated with the initial Cry1Ac protein concentration, but it was only correlated with the mass decomposition rate constants under the flooded condition. No Cry1Ac protein was detected in the soils surrounding the buried residue. Our results did not reveal any evidence that the stacked genes (Bt/CpTI) or the presence of the Cry1Ac protein influenced the decomposition dynamics of the rice residues. Furthermore, our results suggested that field drainage after residue incorporation would promote Cry1Ac protein degradation. Copyright © 2015 Elsevier Inc. All rights reserved.

Parental spirituality in life-threatening pediatric cancer.

PubMed

Nicholas, David B; Barrera, Maru; Granek, Leeat; D'Agostino, Norma Mammone; Shaheed, Jenny; Beaune, Laura; Bouffet, Eric; Antle, Beverley

2017-01-01

This study addressed parental spirituality in the context of pediatric cancer with a poor prognosis. Drawing upon previous research implementing a longitudinal grounded theory design examining parental hope, 35 parents were interviewed regarding their experiences with an emergent description of the role of spirituality in parents' daily lives. Spirituality included religious beliefs and practices, notions of a higher force or cosmos, relationship with a divine being, as well as elements emerging from meaning-making and relationships. Parental expectations of spirituality remained relatively constant across data collection time points (3-9 months postdiagnosis), although limited variation occurred relative to shifting circumstance (e.g., deterioration of the child's condition). Spirituality appeared to offer: greater acceptance of parents' inability to protect their child from harm related to her/his life-threatening illness, guidance and emotion decompression, and support from one's faith community. Recommendations for integrating spiritual assessment in clinical care practice are offered.

150 Years of the American Nautical Almanac Office

NASA Astrophysics Data System (ADS)

Dick, S. J.

1999-05-01

In 1849, 50 years before the founding of the American Astronomical Society, the American Nautical Almanac Office was established in Cambridge, Massachusetts. Although the British had published a Nautical Almanac since 1767, both patriotic and practical reasons lay behind the founding of an American Nautical Almanac Office in the context of the growth of science in the United States. Lt. Charles Henry Davis served as the first Superintendent. In 1866 the Office moved to Washington, D. C., and beginning in 1893 it was physically located at the new (present) site of the U. S. Naval Observatory, of which it became a part over the next few years, and where it has since remained. >From its beginning the work of the Office was much broader than the publication of data for navigation. The Office also sought to improve the theories of motion of the Sun, Moon and planets, and the astronomical constants on which the Almanac was based. Under Simon Newcomb, Superintendent of the Office from 1877 until his retirement in 1897, a consistent system of constants was devised; some of these constants remained unchanged until 1984. The American Nautical Almanac Office was dominated before World War II by its Directors William S. Eichelberger (1910-1929) and A. James Robertson (1929-1939). During the War years Wallace J. Eckert introduced punched card techniques to the Office. Gerald Clemence used these techniques to improve planetary theories during his years as Director (1945-1958), and also ushered in the era of the electronic computer for both research and production. International collaboration was a hallmark of the tenures of Clemence, Edgar Woolard, Raynor Duncombe and P. K. Seidelmann, who also implemented changes necessitated by the Space Age. Since 1990 the Nautical Almanac Office has been part of the Astronomical Applications Department of the Naval Observatory.

The constant current loop: A new paradigm for resistance signal conditioning

NASA Astrophysics Data System (ADS)

Anderson, Karl F.

1994-02-01

A practical single constant current loop circuit for the signal conditioning of variable-resistance transducers has been synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature detector are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. Theoretical predictions supported by laboratory testing confirm the following features of the approach: (1) dc response; (2) the electrical output is unaffected by extremely large variation in the resistance of any or all lead wires; (3) the electrical output remains zero for no change in gage resistance; (4) the electrical output is inherently linear with respect to gage resistance change; (5) the sensitivity is double that of a Wheatstone bridge circuit; and (6) the same excitation wires can serve multiple independent gages. An adaptation of current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations. These innovations are the subject of NASA patent applications.

The constant current loop: A new paradigm for resistance signal conditioning

NASA Astrophysics Data System (ADS)

Anderson, Karl F.

1992-10-01

A practical single constant current loop circuit for the signal conditioning of variable resistance transducers has been synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature device are examples of variable resistance sensors. Lead wires connect variable resistance sensors to remotely located signal conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. Theoretical predictions supported by laboratory testing confirm the following features of the approach: (1) dc response; (2) the electrical output is unaffected by extremely large variations in the resistance of any or all lead wires; (3) the electrical output remains zero for no change in gage resistance; (4) the electrical output is inherently linear with respect to gage resistance change; (5) the sensitivity is double that of a Wheatstone bridge circuit; and (6) the same excitation wires can serve multiple independent gages. An adaptation of current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations. These innovations are the subject of NASA patent applications.

The constant current loop: A new paradigm for resistance signal conditioning

NASA Astrophysics Data System (ADS)

Anderson, Karl F.

A practical, single, constant-current loop circuit for the signal conditioning of variable-resistance transducers was synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature device are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. Theoretical predictions supported by laboratory testing confirm the following features of the approach: (1) the dc response; (2) the electrical output is unaffected by extremely large variations in the resistance of any or all lead wires; (3) the electrical output remains zero for no change in gage resistance; (4) the electrical output is inherently linear with respect to gage resistance change; (5) the sensitivity is double that of a Wheatstone bridge circuit; and (6) the same excitation and sense wires can serve multiple independent gages. An adaptation of the current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations. These innovations are the subject of NASA patent applications.

The constant current loop: A new paradigm for resistance signal conditioning

NASA Technical Reports Server (NTRS)

Anderson, Karl F.

1994-01-01

A practical single constant current loop circuit for the signal conditioning of variable-resistance transducers has been synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature detector are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. Theoretical predictions supported by laboratory testing confirm the following features of the approach: (1) dc response; (2) the electrical output is unaffected by extremely large variation in the resistance of any or all lead wires; (3) the electrical output remains zero for no change in gage resistance; (4) the electrical output is inherently linear with respect to gage resistance change; (5) the sensitivity is double that of a Wheatstone bridge circuit; and (6) the same excitation wires can serve multiple independent gages. An adaptation of current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations. These innovations are the subject of NASA patent applications.

The constant current loop: A new paradigm for resistance signal conditioning

NASA Technical Reports Server (NTRS)

Anderson, Karl F.

1993-01-01

A practical, single, constant-current loop circuit for the signal conditioning of variable-resistance transducers was synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature device are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. Theoretical predictions supported by laboratory testing confirm the following features of the approach: (1) the dc response; (2) the electrical output is unaffected by extremely large variations in the resistance of any or all lead wires; (3) the electrical output remains zero for no change in gage resistance; (4) the electrical output is inherently linear with respect to gage resistance change; (5) the sensitivity is double that of a Wheatstone bridge circuit; and (6) the same excitation and sense wires can serve multiple independent gages. An adaptation of the current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations. These innovations are the subject of NASA patent applications.

Improved Delivery of Cardiovascular Care (IDOCC): Findings from Narrative Reports by Practice Facilitators.

PubMed

Liddy, Clare; Rowan, Margo; Valiquette-Tessier, Sophie-Claire; Drosinis, Paul; Crowe, Lois; Hogg, William

2017-03-01

Practice facilitation can help family physicians adopt evidence-based guidelines. However, many practices struggle to effectively implement practice changes that result in meaningful improvement. Building on our previous research, we examined the barriers to and enablers of implementation perceived by practice facilitators (PF) in helping practices to adopt the Improved Delivery of Cardiovascular Care (IDOCC) program, which took place at 84 primary care practices in Ottawa, Canada between April 2008 and March 2012. We conducted a qualitative analysis of PFs' narrative reports using a multiple case study design. We used a combined purposeful sampling approach to identify cases that 1) reflected experiences typical of the broader sample and 2) presented sufficient breadth of experience from each project step and family practice model. Sampling continued until data saturation was reached. Team members conducted a qualitative analysis of reports using an open and axial coding style and a constant comparative approach. Barriers and enablers were divided into five constructs: structural, organizational, provider, patient, and innovation. Narratives from 13 practice sites were reviewed. A total of 8 barriers and 11 enablers were consistently identified across practices. Barriers were most commonly reported at the organizational (n = 3) and structural level, (n = 2) while enablers were most common at the innovation level (n = 6). While physicians responded positively to PFs' presence and largely supported their recommendations for practice change, organizational and structural aspects such as lack of time, minimal staff engagement, and provider reimbursement remained too great for practices to successfully implement practice-level changes. Trial Registration: ClinicalTrials.gov, NCT00574808.

[Marketing in veterinary practice; a theoretical framework].

PubMed

Schuurmans, A J; Smidts, A

1990-03-15

An increase in the number of veterinarians, while at the same time the number of animals has remained constant, has resulted in growing competition. By extending the range of products and by enlarging the veterinarians' scope of activities this competition can be decreased. A marketing-orientation will be helpful in this respect. This article indicates in which way marketing concepts can be used in a veterinary practice. The services of the veterinarian will be looked at by means of the Abell approach. This focuses on the functions performed by the services and examines, per function performed, for whom this might be interesting and which alternatives there might be. Next the concept of market segmentation is filled in for a veterinary practice by means of a hypothetical example. The marketing mix (product, place, price, promotion and personnel) is given considerable attention. The last element of marketing in a veterinary practice that is discussed here is the marketing information system. In a next article the question will be answered how marketing-directed the Dutch veterinarian works nowadays. To find this out research has been done; 166 vets were interviewed by telephone for approximately 40 minutes each.

Creation and implementation of an effective physician compensation methodology for a nonprofit medical foundation.

PubMed

Ferch, A W

2000-01-01

The foundation has determined that the adjusted gross billing methodology is a viable method to be considered for a nonprofit medical foundation in compensating physicians. The foundation continues to experiment with the margin formula and is exploring other potential formulas, but believes with certain modifications the percentage of adjusted gross billing methodology can be effective and useful because of its simplicity, ease of administration, and motivational effect on the physicians. The primary improvement to the model needed would be the ability to adjust the formula on a frequent basis for individual practice variations. Modifications will continue to be made as circumstances change, but the basic principles will remain constant.

Optical parametric amplifiers using chirped quasi-phase-matching gratings I: practical design formulas

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

Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, M. M.

Optical parametric amplifiers using chirped quasi-phase-matching (QPM) gratings offer the possibility of engineering the gain and group delay spectra. We give practical formulas for the design of such amplifiers. We consider linearly chirped QPM gratings providing constant gain over a broad bandwidth, sinusoidally modulated profiles for selective frequency amplification and a pair of QPM gratings working in tandem to ensure constant gain and constant group delay at the same time across the spectrum. Finally, the analysis is carried out in the frequency domain using Wentzel–Kramers–Brillouin analysis.

Contextual determinants of the social-transfer-of-learning effect.

PubMed

Milanese, Nadia; Iani, Cristina; Sebanz, Natalie; Rubichi, Sandro

2011-06-01

A recent study (Milanese et al. in Cogn 116(1):15-22, 2010) showed that performing a spatial compatibility task with incompatible S-R links (i.e., the practice task) alongside a co-actor eliminates the Simon effect in a subsequent joint Simon task (i.e., the transfer task). In the present study, we conducted three experiments to individuate which elements of the practice task need to remain constant for this social-transfer-of-learning to occur. In Experiment 1, participants performed the practice task alongside a co-actor and the Simon task with a different co-actor; in Experiment 2, they performed the practice task alongside a co-actor and the Simon task with the same co-actor after exchanging their seats. Results showed a modulation of the joint Simon effect in Experiment 1 only. In Experiment 2, we found a regular joint Simon effect. These results indicate that, while co-actor identity is not crucial, other elements of the context, such as keeping the same position across tasks, are necessary for the social-transfer-of-learning to occur. On the whole, our data suggest that the social-transfer-of-learning effect is not tuned to a specific co-actor and depends on spatial parameters of the practice and transfer tasks.

Constant voltage electro-slag remelting control

DOEpatents

Schlienger, Max E.

1996-01-01

A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an eletrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable.

Dynamics of Contact Line Pinning and Depinning of Droplets Evaporating on Microribs.

PubMed

Mazloomi Moqaddam, Ali; Derome, Dominique; Carmeliet, Jan

2018-05-15

The contact line dynamics of evaporating droplets deposited on a set of parallel microribs is analyzed with the use of a recently developed entropic lattice Boltzmann model for two-phase flow. Upon deposition, part of the droplet penetrates into the space between ribs because of capillary action, whereas the remaining liquid of the droplet remains pinned on top of the microribs. In the first stage, evaporation continues until the droplet undergoes a series of pinning-depinning events, showing alternatively the constant contact radius and constant contact angle modes. While the droplet is pinned, evaporation results in a contact angle reduction, whereas the contact radius remains constant. At a critical contact angle, the contact line depins, the contact radius reduces, and the droplet rearranges to a larger apparent contact angle. This pinning-depinning behavior goes on until the liquid above the microribs is evaporated. By computing the Gibbs free energy taking into account the interfacial energy, pressure terms, and viscous dissipation due to drop internal flow, we found that the mechanism that causes the unpinning of the contact line results from an excess in Gibbs free energy. The spacing distance and the rib height play an important role in controlling the pinning-depinning cycling, the critical contact angle, and the excess Gibbs free energy. However, we found that neither the critical contact angle nor the maximum excess Gibbs free energy depends on the rib width. We show that the different terms, that is, pressure term, viscous dissipation, and interfacial energy, contributing to the excess Gibbs free energy, can be varied differently by varying different geometrical properties of the microribs. It is demonstrated that, by varying the spacing distance between the ribs, the energy barrier is controlled by the interfacial energy while the contribution of the viscous dissipation is dominant if either rib height or width is changed. Main finding of this is study is that, for microrib patterned surfaces, the energy barrier required for the contact line to depin can be enlarged by increasing the spacing or the rib height, which can be important for practical applications.

Changes in postharvest quality of Swiss chard grown using 3 organic preharvest treatments.

PubMed

Daiss, N; Lobo, M G; Gonzalez, M

2008-08-01

Using storage conditions recommended for conventional chard (4 degrees C, 90% RH and 7 d), the chard treated with some organic preharvest treatments [effective microorganisms, a fermented mixture of effective microorganisms with organic matter (EM-Bokashi + EM), and an auxiliary soil product] lost considerable water (> 2%) and weight (> 25%). These results indicate that organic methods tested produce a vegetable that can not sustain its quality when commercialized through the conventional supply chain. Nevertheless, respiration, color, pH, and titratable acidity practically remained constant during conservation. Ascorbic acid content was constant in chard treated with the different preharvest treatments and collected at 8 wk after sowing (normal harvest). However, the ascorbic acid content of the control chard decreased 60% after 7 d of storage. This vitamin diminished (35%) in chard collected after 19 wk after sowing (late harvest) during the postharvest conservation. The greatest difference in chard quality was registered between sampling dates since chard collected during the late harvest had higher levels of dry matter, sugars, acids, proteins, and ascorbic acid than chard collected during the normal harvest.

Constant voltage electro-slag remelting control

DOEpatents

Schlienger, M.E.

1996-10-22

A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an electrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable. 1 fig.

Constant-Pressure Hydraulic Pump

NASA Technical Reports Server (NTRS)

Galloway, C. W.

1982-01-01

Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

Crack Closure and Fatigue Crack Growth in 2219-T851 Aluminum Alloy

DTIC Science & Technology

1976-08-01

assumes the length of the crack perimeter to remain es - ’I sentially constant. At the maximum load, the crack is ap- proximately parabolic (or ellipical...for center cracked j specimens) in shape. With unloading, the parabola (or el- lipse) is collapsed. The resulting change in shape produces an apparent...reloading process, the electrical potential remained es - j sentially constant initially and was less than that at the corresponding load during unloading

Alternative practices of achieving anaesthesia for dental procedures: a review.

PubMed

Angelo, Zavattini; Polyvios, Charalambous

2018-04-01

Managing pain and anxiety in patients has always been an essential part of dentistry. To prevent pain, dentists administer local anaesthesia (LA) via a needle injection. Unfortunately, anxiety and fear that arise prior to and/or during injection remains a barrier for many children and adults from receiving dental treatment. There is a constant search for techniques to alleviate the invasive and painful nature of the needle injection. In recent years, researchers have developed alternative methods which enable dental anaesthesia to be less invasive and more patient-friendly. The aim of this review is to highlight the procedures and devices available which may replace the conventional needle-administered local anaesthesia. The most known alternative methods in providing anaesthesia in dentistry are: topical anaesthesia, electronic dental anaesthesia, jet-injectors, iontophoresis, and computerized control local anaesthesia delivery systems. Even though these procedures are well accepted by patients to date, it is the authors' opinion that the effectiveness practicality of such techniques in general dentistry is not without limitations.

Reducing Obesity Among People With Disabilities

PubMed Central

Fox, Michael H.; Witten, Mary Helen; Lullo, Carolyn

2015-01-01

Achieving healthy weight for people with disabilities in the United States is a challenge. Obesity rates for adults and children with disabilities are significantly higher than for those without disabilities, with differences remaining even when controlling for other factors. Reasons for this disparity include lack of healthy food options for many people with disabilities living in restrictive environments, difficulty with chewing or swallowing food, medication use contributing to changes in appetite, physical limitations that can reduce a person’s ability to exercise, constant pain, energy imbalance, lack of accessible environments in which to exercise or fully participate in other activities, and resource scarcity among many segments of the disability population. In order for there to be a coordinated national effort to address this issue, a framework needs to be developed from which research, policy, and practice can emerge. This paper reviews existing literature and presents a conceptual model that can be used to inform such a framework, provides examples of promising practices, and discusses challenges and opportunities moving forward. PMID:26113785

Alternative practices of achieving anaesthesia for dental procedures: a review

PubMed Central

2018-01-01

Managing pain and anxiety in patients has always been an essential part of dentistry. To prevent pain, dentists administer local anaesthesia (LA) via a needle injection. Unfortunately, anxiety and fear that arise prior to and/or during injection remains a barrier for many children and adults from receiving dental treatment. There is a constant search for techniques to alleviate the invasive and painful nature of the needle injection. In recent years, researchers have developed alternative methods which enable dental anaesthesia to be less invasive and more patient-friendly. The aim of this review is to highlight the procedures and devices available which may replace the conventional needle-administered local anaesthesia. The most known alternative methods in providing anaesthesia in dentistry are: topical anaesthesia, electronic dental anaesthesia, jet-injectors, iontophoresis, and computerized control local anaesthesia delivery systems. Even though these procedures are well accepted by patients to date, it is the authors' opinion that the effectiveness practicality of such techniques in general dentistry is not without limitations. PMID:29744382

Water Relations, Gas Exchange, and Nutrient Response to a Long Term Constant Water Deficit

NASA Technical Reports Server (NTRS)

Berry, Wade L.; Goldstein, Guillermo; Dreschel, Thomas W.; Wheeler, Raymond M.; Sager, John C.; Knott, William M.

1992-01-01

Wheat plants (Triticum aestivum) were grown for 43 days in a micro-porous tube nutrient delivery system. Roots were unable to penetrate the microporous tube, but grew on the surface and maintained capillary contact with the nutrient solution on the inside of the tube through the 5-microns pores of the porous tube. Water potential in the system was controlled at -0.4, -0.8, and -3.0 kPa by adjusting the applied pressure (hydrostatic head) to the nutrient solution flowing through the microporous tubes. A relatively small decrease in applied water potential from -0.4 to -3.0 kPa resulted in a 34% reduction of shoot growth but only a moderate reduction in the mid-day leaf water potential from - 1.3 to - 1.7 MPa. Carbon dioxide assimilation decreased and water use efficiency increased with the more negative applied water Potentials, while intercellular C02 concentration remained constant. The physiological responses observed in this study in response to small constant differences in applied water potentials were much greater than expected from either the applied water potential or the observed plant water potential. Even though the micro-porous tube may not represent natural conditions and could possibly introduce morphological and physiological artifacts , it enables a high degree of control of water potential that facilitates the investigation of many aspects of water relations not practical with other experimental systems.

Remaining useful life prediction of degrading systems subjected to imperfect maintenance: Application to draught fans

NASA Astrophysics Data System (ADS)

Wang, Zhao-Qiang; Hu, Chang-Hua; Si, Xiao-Sheng; Zio, Enrico

2018-02-01

Current degradation modeling and remaining useful life prediction studies share a common assumption that the degrading systems are not maintained or maintained perfectly (i.e., to an as-good-as new state). This paper concerns the issues of how to model the degradation process and predict the remaining useful life of degrading systems subjected to imperfect maintenance activities, which can restore the health condition of a degrading system to any degradation level between as-good-as new and as-bad-as old. Toward this end, a nonlinear model driven by Wiener process is first proposed to characterize the degradation trajectory of the degrading system subjected to imperfect maintenance, where negative jumps are incorporated to quantify the influence of imperfect maintenance activities on the system's degradation. Then, the probability density function of the remaining useful life is derived analytically by a space-scale transformation, i.e., transforming the constructed degradation model with negative jumps crossing a constant threshold level to a Wiener process model crossing a random threshold level. To implement the proposed method, unknown parameters in the degradation model are estimated by the maximum likelihood estimation method. Finally, the proposed degradation modeling and remaining useful life prediction method are applied to a practical case of draught fans belonging to a kind of mechanical systems from steel mills. The results reveal that, for a degrading system subjected to imperfect maintenance, our proposed method can obtain more accurate remaining useful life predictions than those of the benchmark model in literature.

Translational Dielectric Friction on a Chain of Charged Spheres

PubMed Central

Boughammoura, Sondès; M'halla, Jalel

2014-01-01

We have proved in details that the dielectric friction remains the principal frictional effect for a stretched polyion modeled as a chain of charged spheres, whereas, in the case of Manning's model (infinite thread with a continuous distribution of charge), this friction effect is nonexistent. According to this chain model, it is therefore possible to detect by conductivity measurements any transition from a coiled configuration (ellipsoidal model) to a stretched configuration during dilution process. We have also underlined the important interdependence between the dielectric friction and the ionic condensation of the counterions, in order to distinguish between the Ostwald regime and the Manning regime for which the degree of condensation is practically constant in a large range of concentrations. PMID:24672333

Electric field and space charge distribution measurement in transformer oil struck by impulsive high voltage

NASA Astrophysics Data System (ADS)

Sima, Wenxia; Guo, Hongda; Yang, Qing; Song, He; Yang, Ming; Yu, Fei

2015-08-01

Transformer oil is widely used in power systems because of its excellent insulation properties. The accurate measurement of electric field and space charge distribution in transformer oil under high voltage impulse has important theoretical and practical significance, but still remains challenging to date because of its low Kerr constant. In this study, the continuous electric field and space charge distribution over time between parallel-plate electrodes in high-voltage pulsed transformer oil based on the Kerr effect is directly measured using a linear array photoelectrical detector. Experimental results demonstrate the applicability and reliability of this method. This study provides a feasible approach to further study the space charge effects and breakdown mechanisms in transformer oil.

Natural head position: An overview.

PubMed

Meiyappan, N; Tamizharasi, S; Senthilkumar, K P; Janardhanan, K

2015-08-01

Cephalometrics has given us a different perspective of interpreting various skeletal problems in the dentofacial complex. Natural head position (NHP) is a reproducible, physiologically determined aspect of function. To determine NHP, a horizontal or vertical reference line outside the crania was used, but preference was given generally to the horizontal. Various intra and extracranial cephalometric horizontal reference planes have been used to formulate diagnosis and plan individualized treatment for an integrated correction of the malocclusion cephalometrics is constantly undergoing refinements in its techniques and analyses to improve the clinical applications. Even though various methods for establishing NHP have been proposed, still it remains a challenge to the clinicians to implement the concept of NHP thoroughly in all the stages of treatment because of practical difficulties in the clinical scenario.

Dielectric Properties of PANI/CuO Nanocomposites

NASA Astrophysics Data System (ADS)

Ambalagi, Sharanabasamma M.; Devendrappa, Mahalesh; Nagaraja, Sannakki; Sannakki, Basavaraja

2018-02-01

The combustion method is used to prepare the Copper Oxide (CuO) nanoparticles. The nanocomposites of Polyaniline (PANI) by doping with copper oxide nanoparticles have synthesized at 10, 20, 30, 40 and 50 different weight percentages during the in-situ polymerization. The samples of nanocomposite of PANI-CuO were characterized by using X-Ray diffraction (XRD) technique. The physical properties such as dielectric constant, dielectric loss and A C conductivity of the nanocomposites are studied as a function of frequency in the range 5Hz-35MHz at room temperature. It is found that the dielectric constant decreases as the frequency increases. The dielectric constant it remains constant at higher frequencies and it is also observed that in particular frequency both the dielectric constant and dielectric loss are decreased as a weight percentage of CuO increased. In case of AC conductivity it is found that as the frequency increases the AC conductivity remains constant up to 3.56MHz and afterwards it increases as frequency increases. This is due to the increase in charge carriers through the hopping mechanism in the polymer nanocomposites. It is also observed that as a weight percentage of CuO increased the AC conductivity is also increasing at a particular frequency.

Effects of Prior Aging on the Creep Response of Carbon Fiber Reinforced PMR-15 Neat Resin at 288 C in an Air Environment

DTIC Science & Technology

2007-06-01

strain versus creep time curves. During creep , stress remains constant, but strain increases. The creep curves of the unaged specimens at 30...recovery period and then levels off and remains nearly constant until the end of the recovery period. The amount of creep strain recovered may...EFFECTS OF PRIOR AGING ON THE CREEP RESPONSE OF CARBON FIBER REINFORCED PMR-15 NEAT RESIN AT 288ºC IN

Grooming and cultural socialization: A mixed method study of caregiving practices in Burma (Myanmar) and the United States†

PubMed Central

Thein-Lemelson, Seinenu M

2015-01-01

Grooming behaviours are thought to be a crucial aspect of parenting and integral to the sociality of non-human mammals, but there have been few empirical studies on how grooming might be relevant to parenting and socialization processes in humans. Study 1 is a quantitative cross-cultural comparison of grooming practices in two cultural settings: an urban centre in Burma (Myanmar) and an urban centre in the United States. The study uses naturalistic video data of 57 families to analyse grooming behaviours directed at children. A broad range of ages was sampled in each culture to examine the developmental trajectory of grooming behaviours. Results indicate that significant cultural differences exist between Burma and the United States, with Burmese children being groomed by their caregivers more often than U.S. children. Results also indicate that cultural differences in grooming practices begin early and remain constant across age. An unexpected finding was that Burmese families were more variable in their behaviour than U.S. families. Study 2 attempts to explain this variability by using ethnography to describe how sociodemographic changes in Burma are leading to changes in parental values and socialization practices in the schools, but how embodied primary care in the homes appear resistant to change. PMID:25530498

Using Constant Time Delay to Teach Braille Word Recognition

ERIC Educational Resources Information Center

Hooper, Jonathan; Ivy, Sarah; Hatton, Deborah

2014-01-01

Introduction: Constant time delay has been identified as an evidence-based practice to teach print sight words and picture recognition (Browder, Ahlbrim-Delzell, Spooner, Mims, & Baker, 2009). For the study presented here, we tested the effectiveness of constant time delay to teach new braille words. Methods: A single-subject multiple baseline…

Natural uranium and strontium isotope tracers of water sources and surface water-groundwater interactions in arid wetlands: Pahranagat Valley, Nevada, USA

USGS Publications Warehouse

Paces, James B.; Wurster, Frederic C.

2014-01-01

Near-surface physical and chemical process can strongly affect dissolved-ion concentrations and stable isotope compositions of water in wetland settings, especially under arid climate conditions. In contrast, heavy radiogenic isotopes of strontium (87Sr/86Sr) and uranium (234U/238U) remain largely unaffected and can be used to help identify unique signatures from different sources and quantify end-member mixing that would otherwise be difficult to determine. The utility of combined Sr and U isotopes are demonstrated in this study of wetland habitats on the Pahranagat National Wildlife Refuge, which depend on supply from large-volume springs north of the Refuge, and from small-volume springs and seeps within the Refuge. Water budgets from these sources have not been quantified previously. Evaporation, transpiration, seasonally variable surface flow, and water management practices complicate the use of conventional methods for determining source contributions and mixing relations. In contrast, 87Sr/86Sr and 234U/238U remain unfractionated under these conditions, and compositions at a given site remain constant. Differences in Sr- and U-isotopic signatures between individual sites can be related by simple two- or three-component mixing models. Results indicate that surface flow constituting the Refuge’s irrigation source consists of a 65:25:10 mixture of water from two distinct regionally sourced carbonate aquifer springs, and groundwater from locally sourced volcanic aquifers. Within the Refuge, contributions from the irrigation source and local groundwater are readily determined and depend on proximity to those sources as well as water management practices.

Natural uranium and strontium isotope tracers of water sources and surface water-groundwater interactions in arid wetlands - Pahranagat Valley, Nevada, USA

NASA Astrophysics Data System (ADS)

Paces, James B.; Wurster, Frederic C.

2014-09-01

Near-surface physical and chemical process can strongly affect dissolved-ion concentrations and stable-isotope compositions of water in wetland settings, especially under arid climate conditions. In contrast, heavy radiogenic isotopes of strontium (87Sr/86Sr) and uranium (234U/238U) remain largely unaffected and can be used to help identify unique signatures from different sources and quantify end-member mixing that would otherwise be difficult to determine. The utility of combined Sr and U isotopes are demonstrated in this study of wetland habitats on the Pahranagat National Wildlife Refuge, which depend on supply from large-volume springs north of the Refuge, and from small-volume springs and seeps within the Refuge. Water budgets from these sources have not been quantified previously. Evaporation, transpiration, seasonally variable surface flow, and water management practices complicate the use of conventional methods for determining source contributions and mixing relations. In contrast, 87Sr/86Sr and 234U/238U remain unfractionated under these conditions, and compositions at a given site remain constant. Differences in Sr- and U-isotopic signatures between individual sites can be related by simple two- or three-component mixing models. Results indicate that surface flow constituting the Refuge's irrigation source consists of a 65:25:10 mixture of water from two distinct regionally sourced carbonate-aquifer springs, and groundwater from locally sourced volcanic aquifers. Within the Refuge, contributions from the irrigation source and local groundwater are readily determined and depend on proximity to those sources as well as water management practices.

What works: a realist evaluation case study of intermediaries in infection control practice.

PubMed

Williams, Lynne; Burton, Christopher; Rycroft-Malone, Jo

2013-04-01

To report a study of an intermediary programme in infection control practice in one hospital in the UK. Promoting best evidence in everyday practice is a constant problem in infection control. Intermediaries can influence the transfer and use of evidence in health care, but there remains a lack of evidence and theory about the specific actions and change processes, which can be successful in improving infection control practices. An in-depth mixed methods case study. The study was undertaken in 2011. Participants were recruited through purposive sampling and included frontline staff, managers and nurses in intermediary roles in infection control. For frontline staff, intermediary presence triggered a modification in behaviour. Different reactions were noted from the intermediaries' high level of physical presence in clinical areas, the facilitative approaches they used to give feedback and the specific teaching strategies they employed to meet frontline staff needs. The specific intermediary actions uncovered in this study were contingent on the prevailing systems for performance management, organisational commitment and efforts in clinical areas to foster a collegiate environment. The study provides theoretical threads of how intermediaries can be successful in promoting evidence use under certain contextual conditions. Further testing of the specific intermediary mechanisms uncovered in this study will contribute to understanding different approaches that work in infection control in embedding evidence in practice. © 2012 Blackwell Publishing Ltd.

The hubble constant.

PubMed

Huchra, J P

1992-04-17

The Hubble constant is the constant of proportionality between recession velocity and distance in the expanding universe. It is a fundamental property of cosmology that sets both the scale and the expansion age of the universe. It is determined by measurement of galaxy The Hubble constant is the constant of proportionality between recession velocity and development of new techniques for the measurements of galaxy distances, both calibration uncertainties and debates over systematic errors remain. Current determinations still range over nearly a factor of 2; the higher values favored by most local measurements are not consistent with many theories of the origin of large-scale structure and stellar evolution.

The midwife: a community resource.

PubMed

Atucha Lma; Crone, C D

1979-09-01

World Education is planning a training program for illiterate midwives in Colombia. Program design is based on the premise that midwives do not need to become literate to learn and practice new skills. The educational approach follows three principles: 1) the training process and materials are to be related to practical problems, 2) the midwives will not need to learn reading and writing, and 3) the program will be designed specifically to teach the illiterate adult. The program must be designed in such a way that the midwives will put the new methods and principles into practice. The teaching materials will: 1) be understandable to the illiterate adult; 2) use symbols and/or stick figures; 3) be clear and understandable, presenting an initial idea as well as a stimulus for recalling the concept; 4) be easily adaptable to different cultures; and 5) be durable so that the midwives may continue to use the materials. The "code" of symbols will remain constant so that other materials can be supplied on a continuing basis to the midwives after completion of the training program. This program affords the opportunity to establish whether or not training programs will close the gap between the theory of community participation and actual participation of community members.

Eucalyptus plantations for energy production in Hawaii. 1980 annual report, January 1980-December 1980

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

Whitesell, C. D.

1980-01-01

In 1980 200 acres of eucalyptus trees were planted for a research and development biomass energy plantation bringing the total area under cultivation to 300 acres. Of this total acreage, 90 acres or 30% was planted in experimental plots. The remaining 70% of the cultivated area was closely monitored to determine the economic cost/benefit ratio of large scale biomass energy production. In the large scale plantings, standard field practices were set up for all phases of production: nursery, clearing, planting, weed control and fertilization. These practices were constantly evaluated for potential improvements in efficiency and reduced cost. Promising experimental treatmentsmore » were implemented on a large scale to test their effectiveness under field production conditions. In the experimental areas all scheduled data collection in 1980 has been completed and most measurements have been keypunched and analyzed. Soil samples and leaf samples have been analyzed for nutrient concentrations. Crop logging procedures have been set up to monitor tree growth through plant tissue analysis. An intensive computer search on biomass, nursery practices, harvesting equipment and herbicide applications has been completed through the services of the US Forest Service.« less

Fluorinated epoxy resins with high glass transition temperatures

NASA Technical Reports Server (NTRS)

Griffith, James R.

1991-01-01

Easily processed liquid resins of low dielectric constants and high glass transition temperatures are useful for the manufacture of certain composite electronic boards. That combination of properties is difficult to acquire when dielectric constants are below 2.5, glass transition temperatures are above 200 C and processability is of conventional practicality. A recently issued patent (US 4,981,941 of 1 Jan. 1991) teaches practical materials and is the culmination of 23 years of research and effort and 15 patents owned by the Navy in the field of fluorinated resins of several classes. In addition to high fluorine content, practical utility was emphasized.

Dielectric Properties of PMMA and its Composites with ZrO2

NASA Astrophysics Data System (ADS)

Sannakki, Basavaraja; Anita

The polymer films of PMMA with different thickness and its composites with ZrO2 at various weight percentages but of same thickness have been studied. The determination of its dielectric properties, dielectric loss, a.conductivity and dielectric modulus were carried out using capacitance measurements of the above samples as a function of frequency, over the range 50 Hz - 5 MHz at room temperature. The films of PMMA and its composites have been characterized using X-Ray Diffractometer. The dielectric permittivity of films of PMMA behaves nonlinearly as frequency increases over the range 50-300 Hz, where as above 300 Hz the values of dielectric constant remains constant. But it is observed that the dielectric constant of PMMA increases as thickness of the film increases. In case of composite films of PMMA with ZrO2 the values of dielectric permittivity decreases gradually up to frequency of around 1 KHz and at higher frequencies it remains constant for all the weight percentages of ZrO2. The complex form of dielectric modulus of PMMA is obtained from the experimentally measured data of dielectric constant and dielectric loss values. The relaxation time of the orientation of dipoles is obtained from the peak value of angular frequency through the plots of imaginary part of electrical modulus as function of frequency. The impedance of PMMA polymer increases as thickness of the films increases. The a c conductivity of PMMA film remains constant up to frequency of 1 MHz and above. It shows a nonlinear phenomenon with peak values at frequency 4 MHz. Shape and size of the nanoparticles of composite film of PMMA with ZrO2 was analyzed by Field Emission Scanning Electron Microscope (FESEM).

Overjet and overbite analysis during the eruption of the upper permanent incisors.

PubMed

Cuoghi, Osmar A; Sella, Rodrigo C; Mamede, Igo; de Macedo, Fernanda A; Miranda-Zamalloa, Yésselin M; de Mendonça, Marcos R

2009-01-01

ABSTRACT The purpose of this study was to analyze the overjet and overbite behavior during eruption of the upper permanent incisors. Fourth-eight plaster casts of 16 patients from ages 6-13 years were appraised longitudinally. It was found that the overjet remains constant, starting at the eruption of the upper permanent central incisors until eruption of the upper permanent canine teeth, while the overbite increases after eruption of the upper permanent lateral incisors and remains constant with the eruption of the canine teeth.

A simple cosmology with a varying fine structure constant.

PubMed

Sandvik, Håvard Bunes; Barrow, John D; Magueijo, João

2002-01-21

We investigate the cosmological consequences of a theory in which the electric charge e can vary. In this theory the fine structure "constant," alpha, remains almost constant in the radiation era, undergoes a small increase in the matter era, but approaches a constant value when the universe starts accelerating because of a positive cosmological constant. This model satisfies geonuclear, nucleosynthesis, and cosmic microwave background constraints on time variation in alpha, while fitting the observed accelerating Universe and evidence for small alpha variations in quasar spectra. It also places specific restrictions on the nature of the dark matter. Further tests, involving stellar spectra and Eötvös experiments, are proposed.

Procedural Adaptations for Use of Constant Time Delay to Teach Highly Motivating Words to Beginning Braille Readers

ERIC Educational Resources Information Center

Ivy, Sarah E.; Guerra, Jennifer A.; Hatton, Deborah D.

2017-01-01

Introduction: Constant time delay is an evidence-based practice to teach sight word recognition to students with a variety of disabilities. To date, two studies have documented its effectiveness for teaching braille. Methods: Using a multiple-baseline design, we evaluated the effectiveness of constant time delay to teach highly motivating words to…

Commuting fruit bats beneficially modulate their flight in relation to wind.

PubMed

Sapir, Nir; Horvitz, Nir; Dechmann, Dina K N; Fahr, Jakob; Wikelski, Martin

2014-05-07

When animals move, their tracks may be strongly influenced by the motion of air or water, and this may affect the speed, energetics and prospects of the journey. Flying organisms, such as bats, may thus benefit from modifying their flight in response to the wind vector. Yet, practical difficulties have so far limited the understanding of this response for free-ranging bats. We tracked nine straw-coloured fruit bats (Eidolon helvum) that flew 42.5 ± 17.5 km (mean ± s.d.) to and from their roost near Accra, Ghana. Following detailed atmospheric simulations, we found that bats compensated for wind drift, as predicted under constant winds, and decreased their airspeed in response to tailwind assistance such that their groundspeed remained nearly constant. In addition, bats increased their airspeed with increasing crosswind speed. Overall, bats modulated their airspeed in relation to wind speed at different wind directions in a manner predicted by a two-dimensional optimal movement model. We conclude that sophisticated behavioural mechanisms to minimize the cost of transport under various wind conditions have evolved in bats. The bats' response to the wind is similar to that reported for migratory birds and insects, suggesting convergent evolution of flight behaviours in volant organisms.

Proposed model for the flagellar rotary motor with shear stress transmission

PubMed Central

Mitsui, Toshio; Ohshima, Hiroyuki

2012-01-01

Most bacteria that swim are propelled by flagellar filaments, which are driven by a rotary motor powered by proton flux. The motor consists of the rotor and the stator. The stator consists of about 8 MotA-Mot B complex. There seems to be no definite information about the structure between the rotor and the stator, and it is examined whether the experimental data can be explained based upon the following assumptions. (a) There is viscoelastic medium between the rotor and the stator. (b) MotA-MotB complex has an electric dipole moment and produces shear stress in the electric field by a proton in the channel. Calculation results based upon these assumptions are in good agreement with the following experimental observations. (1) One revolution of the flagellar rotation consists of a constant number of steps. (2) The rotation velocity of the rotor is proportional to the trans-membrane potential difference. (3) When the rotational velocity of a flagellum is changed by adjusting the viscosity of the outer fluid, the torque for the cell to rotate a flagellum is practically constant but sharply decreases when the rotational velocity increases over a critical value. (4) The rotation direction remains the same when the sign of the electrochemical potential gradient is reversed. (5) The cell produces constant torque to rotate the flagellum even when the cell is rotated by externally applied torque. (6) A simple switch mechanism is proposed for chemotaxis. PMID:27493532

Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging.

PubMed

Bültmann, Eva; Nägele, Thomas; Lanfermann, Heinrich; Klose, Uwe

2017-01-01

We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic.

[Thyroid dysfunction during pregnancy].

PubMed

Díez, Juan J; Iglesias, Pedro; Donnay, Sergio

2015-10-21

Recent clinical practice guidelines on thyroid dysfunction and pregnancy have changed health care provided to pregnant women, although their recommendations are under constant revision. Trimester- and area-specific reference ranges for serum thyroid-stimulating hormone are required for proper diagnosis of hypothyroidism and hyperthyroidism. There is no doubt on the need of therapy for overt hypothyroidism, while therapy for subclinical hypothyroidism is controversial. Further research is needed to settle adverse effects of isolated hypothyroxinemia and thyroid autoimmunity. Differentiation between hyperthyroidism due to Graves' disease and the usually self-limited gestational transient thyrotoxicosis is critical. It is also important to recognize risk factors for postpartum thyroiditis. Supplementation with iodine is recommended to maintain adequate iodine nutrition during pregnancy and avoid serious consequences in offspring. Controversy remains about universal screening for thyroid disease during pregnancy or case-finding in high-risk women. Opinions of some scientific societies and recent cost-benefit studies favour universal screening. Randomized controlled studies currently under development should reduce the uncertainties that still remain in this area. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Improved Dielectric Properties and Energy Storage Density of Poly(vinylidene fluoride-co-hexafluoropropylene) Nanocomposite with Hydantoin Epoxy Resin Coated BaTiO3.

PubMed

Luo, Hang; Zhang, Dou; Jiang, Chao; Yuan, Xi; Chen, Chao; Zhou, Kechao

2015-04-22

Energy storage materials are urgently demanded in modern electric power supply and renewable energy systems. The introduction of inorganic fillers to polymer matrix represents a promising avenue for the development of high energy density storage materials, which combines the high dielectric constant of inorganic fillers with supernal dielectric strength of polymer matrix. However, agglomeration and phase separation of inorganic fillers in the polymer matrix remain the key barriers to promoting the practical applications of the composites for energy storage. Here, we developed a low-cost and environmentally friendly route to modifying BaTiO3 (BT) nanoparticles by a kind of water-soluble hydantoin epoxy resin. The modified BT nanoparticles exhibited homogeneous dispersion in the ferroelectric polymer poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) matrix and strong interfacial adhesion with the polymer matrix. The dielectric constants of the nanocomposites increased significantly with the increase of the coated BT loading, while the dielectric loss of the nanocomposites was still as low as that of the pure P(VDF-HFP). The energy storage density of the nanocomposites was largely enhanced with the coated BT loading at the same electric field. The nanocomposite with 20 vol % BT exhibited an estimated maximum energy density of 8.13 J cm(-3), which was much higher than that of pure P(VDF-HFP) and other dielectric polymers. The findings of this research could provide a feasible approach to produce high energy density materials for practical application in energy storage.

The Control of Single-color and Multiple-color Visual Search by Attentional Templates in Working Memory and in Long-term Memory.

PubMed

Grubert, Anna; Carlisle, Nancy B; Eimer, Martin

2016-12-01

The question whether target selection in visual search can be effectively controlled by simultaneous attentional templates for multiple features is still under dispute. We investigated whether multiple-color attentional guidance is possible when target colors remain constant and can thus be represented in long-term memory but not when they change frequently and have to be held in working memory. Participants searched for one, two, or three possible target colors that were specified by cue displays at the start of each trial. In constant-color blocks, the same colors remained task-relevant throughout. In variable-color blocks, target colors changed between trials. The contralateral delay activity (CDA) to cue displays increased in amplitude as a function of color memory load in variable-color blocks, which indicates that cued target colors were held in working memory. In constant-color blocks, the CDA was much smaller, suggesting that color representations were primarily stored in long-term memory. N2pc components to targets were measured as a marker of attentional target selection. Target N2pcs were attenuated and delayed during multiple-color search, demonstrating less efficient attentional deployment to color-defined target objects relative to single-color search. Importantly, these costs were the same in constant-color and variable-color blocks. These results demonstrate that attentional guidance by multiple-feature as compared with single-feature templates is less efficient both when target features remain constant and can be represented in long-term memory and when they change across trials and therefore have to be maintained in working memory.

Different auditory feedback control for echolocation and communication in horseshoe bats.

PubMed

Liu, Ying; Feng, Jiang; Metzner, Walter

2013-01-01

Auditory feedback from the animal's own voice is essential during bat echolocation: to optimize signal detection, bats continuously adjust various call parameters in response to changing echo signals. Auditory feedback seems also necessary for controlling many bat communication calls, although it remains unclear how auditory feedback control differs in echolocation and communication. We tackled this question by analyzing echolocation and communication in greater horseshoe bats, whose echolocation pulses are dominated by a constant frequency component that matches the frequency range they hear best. To maintain echoes within this "auditory fovea", horseshoe bats constantly adjust their echolocation call frequency depending on the frequency of the returning echo signal. This Doppler-shift compensation (DSC) behavior represents one of the most precise forms of sensory-motor feedback known. We examined the variability of echolocation pulses emitted at rest (resting frequencies, RFs) and one type of communication signal which resembles an echolocation pulse but is much shorter (short constant frequency communication calls, SCFs) and produced only during social interactions. We found that while RFs varied from day to day, corroborating earlier studies in other constant frequency bats, SCF-frequencies remained unchanged. In addition, RFs overlapped for some bats whereas SCF-frequencies were always distinctly different. This indicates that auditory feedback during echolocation changed with varying RFs but remained constant or may have been absent during emission of SCF calls for communication. This fundamentally different feedback mechanism for echolocation and communication may have enabled these bats to use SCF calls for individual recognition whereas they adjusted RF calls to accommodate the daily shifts of their auditory fovea.

Different Auditory Feedback Control for Echolocation and Communication in Horseshoe Bats

PubMed Central

Liu, Ying; Feng, Jiang; Metzner, Walter

2013-01-01

Auditory feedback from the animal's own voice is essential during bat echolocation: to optimize signal detection, bats continuously adjust various call parameters in response to changing echo signals. Auditory feedback seems also necessary for controlling many bat communication calls, although it remains unclear how auditory feedback control differs in echolocation and communication. We tackled this question by analyzing echolocation and communication in greater horseshoe bats, whose echolocation pulses are dominated by a constant frequency component that matches the frequency range they hear best. To maintain echoes within this “auditory fovea”, horseshoe bats constantly adjust their echolocation call frequency depending on the frequency of the returning echo signal. This Doppler-shift compensation (DSC) behavior represents one of the most precise forms of sensory-motor feedback known. We examined the variability of echolocation pulses emitted at rest (resting frequencies, RFs) and one type of communication signal which resembles an echolocation pulse but is much shorter (short constant frequency communication calls, SCFs) and produced only during social interactions. We found that while RFs varied from day to day, corroborating earlier studies in other constant frequency bats, SCF-frequencies remained unchanged. In addition, RFs overlapped for some bats whereas SCF-frequencies were always distinctly different. This indicates that auditory feedback during echolocation changed with varying RFs but remained constant or may have been absent during emission of SCF calls for communication. This fundamentally different feedback mechanism for echolocation and communication may have enabled these bats to use SCF calls for individual recognition whereas they adjusted RF calls to accommodate the daily shifts of their auditory fovea. PMID:23638137

The effects of capillary forces on the axisymmetric propagation of two-phase, constant-flux gravity currents in porous media

NASA Astrophysics Data System (ADS)

Golding, Madeleine J.; Huppert, Herbert E.; Neufeld, Jerome A.

2013-03-01

The effects of capillary forces on the propagation of two-phase, constant-flux gravity currents in a porous medium are studied analytically and numerically in an axisymmetric geometry. The fluid within a two-phase current generally only partially saturates the pore space it invades. For long, thin currents, the saturation distribution is set by the vertical balance between gravitational and capillary forces. The capillary pressure and relative permeability of the fluid in the current depend on this saturation. The action of capillary forces reduces the average saturation, thereby decreasing the relative permeability throughout the current. This results in a thicker current, which provides a steeper gradient to drive flow, and a more blunt-nose profile. The relative strength of gravity and capillary forces remains constant within a two-phase gravity current fed by a constant flux and spreading radially, due to mass conservation. For this reason, we use an axisymmetric representation of the framework developed by Golding et al. ["Two-phase gravity currents in porous media," J. Fluid Mech. 678, 248-270 (2011)], 10.1017/jfm.2011.110, to investigate the effect on propagation of varying the magnitude of capillary forces and the pore-size distribution. Scaling analysis indicates that axisymmetric two-phase gravity currents fed by a constant flux propagate like t1/2, similar to their single-phase counterparts [S. Lyle, H. E. Huppert, M. Hallworth, M. Bickle, and A. Chadwick, "Axisymmetric gravity currents in a porous medium," J. Fluid Mech. 543, 293-302 (2005)], 10.1017/S0022112005006713, with the effects of capillary forces encapsulated in the constant of proportionality. As a practical application of our new concepts and quantitative evaluations, we discuss the implications of our results for the process of carbon dioxide (CO2) sequestration, during which gravity currents consisting of supercritical CO2 propagate in rock saturated with aqueous brine. We apply our two-phase model including capillary forces to quantitatively assess seismic images of CO2 spreading at Sleipner underneath the North Sea.

On the centenary of Charcot: hysteria, suggestibility and hypnosis.

PubMed

Chertok, L

1984-06-01

In studying hysteria by means of hypnosis, Charcot placed emphasis on the psychological aetiology of the neuroses. Among his pupils, Freud alone grasped this epistemological turning-point, from which he made his great discoveries. But hysteria and hypnosis still remain today largely unknown. We have not yet elucidated the 'mysterious leap' between the psychological and the somatic for the former, and between the relational and the instrumental for the latter. While psychoanalysts have constantly concerned themselves with hysteria, they have shown a lack of interest in hypnosis after Freud abandoned its practice. According to Freud, thanks to transference, affect would be controlled by cognition, a viewpoint eminently suited to satisfy his rationalistic outlook. Affect, however, remains an unknown realm. The affective relationship has, at all events, acquired an ever-increasing importance in psychoanalysis during the last few years, with the emphasis on the early mother-child relationship. The 'affective locus' remains the basic, as well as the most obscure, element in the hypno-suggestive relationship. The behaviourist approach, which quantifies the 'vertical' dimension in depth, is a limited one. The study of the 'horizontal' dimension of subjective experience represents a new line of research, which may make it possible to distinguish different forms of hypnosis. The understanding of hypno-suggestion may throw light on psychoanalysis, psychotherapy, and the human sciences in general.

Grooming and cultural socialization: a mixed method study of caregiving practices in Burma (Myanmar) and the United States.

PubMed

Thein-Lemelson, Seinenu M

2015-02-01

Grooming behaviours are thought to be a crucial aspect of parenting and integral to the sociality of non-human mammals, but there have been few empirical studies on how grooming might be relevant to parenting and socialization processes in humans. Study 1 is a quantitative cross-cultural comparison of grooming practices in two cultural settings: an urban centre in Burma (Myanmar) and an urban centre in the United States. The study uses naturalistic video data of 57 families to analyse grooming behaviours directed at children. A broad range of ages was sampled in each culture to examine the developmental trajectory of grooming behaviours. Results indicate that significant cultural differences exist between Burma and the United States, with Burmese children being groomed by their caregivers more often than U.S. children. Results also indicate that cultural differences in grooming practices begin early and remain constant across age. An unexpected finding was that Burmese families were more variable in their behaviour than U.S. families. Study 2 attempts to explain this variability by using ethnography to describe how sociodemographic changes in Burma are leading to changes in parental values and socialization practices in the schools, but how embodied primary care in the homes appear resistant to change. © 2014 The Authors. International Journal of Psychology published by John Wiley & Sons Ltd on behalf of International Union of Psychological Science.

Illuminating and inspiring: using television historical drama to cultivate contemporary nursing values and critical thinking.

PubMed

McAllister, Margaret; Rogers, Irene; Lee Brien, Donna

2015-01-01

As the world prepares to commemorate the centenary of the First World War, it is timely to discuss meaningful learning activities that students of nursing could be engaged in to encourage them to reflect on the nurse's role then and now. Several films and television series about the war and featuring nursing have already been aired. No doubt there will be many more stories to come. Such stories have the potential to do more than eulogise nursing for students and practitioners. Stories, such as The crimson field, have potential to stimulate serious contemplation about values and cultural practices that have remained constant or have changed and to assist students to develop and articulate values that will be fitting for contemporary practice. Recently, excerpts from the series were examined with a group of nursing students and key learnings were found. These are shared in this paper for the benefit of educators planning to utilise public discourse as triggers to engage nursing students in discussions about nursing values, nursing history and representations of the profession.

Practical issues of biomarker-assisted targeted therapy in precision medicine and immuno-oncology era.

PubMed

Lee, Dae Ho

2018-01-01

The concept of precision medicine is not new, as multiplex and very sensitive methods, or next-generation sequencing and matched targeted cancer therapies, have come to clinical practice. Substantial progress has been made from the discovery to the development and clinical application of biomarkers and matched targeted therapies. However, there still remain many challenges and issues to be overcome in each step, from acquisition of tumour tissues through validation of biomarkers to the final decision on targeted therapy. This review will briefly touch on these issues, hoping to provide a better understanding and application of targeted therapy in cancer treatment in the era of precision medicine and immuno-oncology. It also helps to understand that the meaning or value of biomarker(s) and matched targeted therapy changes along with expansion of knowledge and advance of methodology, and constant efforts have to be made in evaluating the meaning and clinical value during the development and after the establishment of biomarkers or the approval of matched targeted therapies, which might be more complicated by the advent of new therapeutic agents and new diagnostic methods.

Temperature-dependent inotropic and lusitropic indices based on half-logistic time constants for four segmental phases in isovolumic left ventricular pressure-time curve in excised, cross-circulated canine heart.

PubMed

Mizuno, Ju; Mohri, Satoshi; Yokoyama, Takeshi; Otsuji, Mikiya; Arita, Hideko; Hanaoka, Kazuo

2017-02-01

Varying temperature affects cardiac systolic and diastolic function and the left ventricular (LV) pressure-time curve (PTC) waveform that includes information about LV inotropism and lusitropism. Our proposed half-logistic (h-L) time constants obtained by fitting using h-L functions for four segmental phases (Phases I-IV) in the isovolumic LV PTC are more useful indices for estimating LV inotropism and lusitropism during contraction and relaxation periods than the mono-exponential (m-E) time constants at normal temperature. In this study, we investigated whether the superiority of the goodness of h-L fits remained even at hypothermia and hyperthermia. Phases I-IV in the isovolumic LV PTCs in eight excised, cross-circulated canine hearts at 33, 36, and 38 °C were analyzed using h-L and m-E functions and the least-squares method. The h-L and m-E time constants for Phases I-IV significantly shortened with increasing temperature. Curve fitting using h-L functions was significantly better than that using m-E functions for Phases I-IV at all temperatures. Therefore, the superiority of the goodness of h-L fit vs. m-E fit remained at all temperatures. As LV inotropic and lusitropic indices, temperature-dependent h-L time constants could be more useful than m-E time constants for Phases I-IV.

Accurate Determination of the Values of Fundamental Physical Constants: The Basis of the New "Quantum" SI Units

NASA Astrophysics Data System (ADS)

Karshenboim, S. G.

2018-03-01

The metric system appeared as the system of units designed for macroscopic (laboratory scale) measurements. The progress in accurate determination of the values of quantum constants (such as the Planck constant) in SI units shows that the capabilities in high-precision measurement of microscopic and macroscopic quantities in terms of the same units have increased substantially recently. At the same time, relative microscopic measurements (for example, the comparison of atomic transition frequencies or atomic masses) are often much more accurate than relative measurements of macroscopic quantities. This is the basis for the strategy to define units in microscopic phenomena and then use them on the laboratory scale, which plays a crucial role in practical methodological applications determined by everyday life and technologies. The international CODATA task group on fundamental constants regularly performs an overall analysis of the precision world data (the so-called Adjustment of the Fundamental Constants) and publishes their recommended values. The most recent evaluation was based on the data published by the end of 2014; here, we review the corresponding data and results. The accuracy in determination of the Boltzmann constant has increased, the consistency of the data on determination of the Planck constant has improved; it is these two dimensional constants that will be used in near future as the basis for the new definition of the kelvin and kilogram, respectively. The contradictions in determination of the Rydberg constant and the proton charge radius remain. The accuracy of determination of the fine structure constant and relative atomic weight of the electron has improved. Overall, we give a detailed review of the state of the art in precision determination of the values of fundamental constants. The mathematical procedure of the Adjustment, the new data and results are considered in detail. The limitations due to macroscopic properties of material standards (such as the International prototype of the kilogram) and the isotopic composition of substances involved in precision studies in general (as standard measures for the triple point of water) and, in particular, in the determination of the fundamental constants are discussed. The perspectives of the introduction of the new quantum units, which will be free from the mentioned problems, are considered. Many physicists feel no sympathy for the International system of units (SI), believing that it does not properly reflect the character of physical laws. In fact, there are three parallel systems, namely the systems of quantities, system of their units and the related standards. The definition of the units, in particular, the SI units, above all, reflects our ability to perform precision measurements of physical values under certain conditions, in particular, to create appropriate standards. This requirement is not related to the beauty of fundamental laws of nature. More accurate determination of the fundamental constants is one of the areas where we accumulate such experience.

Model Based Mission Assurance in a Model Based Systems Engineering (MBSE) Framework: State-of-the-Art Assessment

NASA Technical Reports Server (NTRS)

Cornford, Steven L.; Feather, Martin S.

2016-01-01

This report explores the current state of the art of Safety and Mission Assurance (S&MA) in projects that have shifted towards Model Based Systems Engineering (MBSE). Its goal is to provide insight into how NASA's Office of Safety and Mission Assurance (OSMA) should respond to this shift. In MBSE, systems engineering information is organized and represented in models: rigorous computer-based representations, which collectively make many activities easier to perform, less error prone, and scalable. S&MA practices must shift accordingly. The "Objective Structure Hierarchies" recently developed by OSMA provide the framework for understanding this shift. Although the objectives themselves will remain constant, S&MA practices (activities, processes, tools) to achieve them are subject to change. This report presents insights derived from literature studies and interviews. The literature studies gleaned assurance implications from reports of space-related applications of MBSE. The interviews with knowledgeable S&MA and MBSE personnel discovered concerns and ideas for how assurance may adapt. Preliminary findings and observations are presented on the state of practice of S&MA with respect to MBSE, how it is already changing, and how it is likely to change further. Finally, recommendations are provided on how to foster the evolution of S&MA to best fit with MBSE.

The 'E' factor -- evolving endodontics.

PubMed

Hunter, M J

2013-03-01

Endodontics is a constantly developing field, with new instruments, preparation techniques and sealants competing with trusted and traditional approaches to tooth restoration. Thus general dental practitioners must question and understand the significance of these developments before adopting new practices. In view of this, the aim of this article, and the associated presentation at the 2013 British Dental Conference & Exhibition, is to provide an overview of endodontic methods and constantly evolving best practice. The presentation will review current preparation techniques, comparing rotary versus reciprocation, and question current trends in restoration of the endodontically treated tooth.

The effects of practice on tracking and subjective workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Robinson, M. A.; Chu, A. L.; Hansen, D. R.; Vercruyssen, M.

1989-01-01

Six college-age male subjects performed one hundred, two-minute trials on a second-order tracking task. After each trial, subjects estimated perceived workload using both the NASA TLX and SWAT workload assessment procedures. Results confirmed an expected performance improvement on the tracking task which followed traditional learning curves within the performance of each individual. Perceived workload also decreased for both scales across trials. While performance variability significantly decreased across trials, workload variability remained constant. One month later, the same subjects returned to complete the second experiment in the sequence which was a retention replication of the first experiment. Results replicated those for the first experiment except that both performance error and workload were at reduced overall levels. Results in general affirm a parallel workload reduction with performance improvement, an observation consistent with a resource-based view of automaticity.

Using high-order polynomial basis in 3-D EM forward modeling based on volume integral equation method

NASA Astrophysics Data System (ADS)

Kruglyakov, Mikhail; Kuvshinov, Alexey

2018-05-01

3-D interpretation of electromagnetic (EM) data of different origin and scale becomes a common practice worldwide. However, 3-D EM numerical simulations (modeling)—a key part of any 3-D EM data analysis—with realistic levels of complexity, accuracy and spatial detail still remains challenging from the computational point of view. We present a novel, efficient 3-D numerical solver based on a volume integral equation (IE) method. The efficiency is achieved by using a high-order polynomial (HOP) basis instead of the zero-order (piecewise constant) basis that is invoked in all routinely used IE-based solvers. We demonstrate that usage of the HOP basis allows us to decrease substantially the number of unknowns (preserving the same accuracy), with corresponding speed increase and memory saving.

Universal freezing of quantum correlations within the geometric approach

PubMed Central

Cianciaruso, Marco; Bromley, Thomas R.; Roga, Wojciech; Lo Franco, Rosario; Adesso, Gerardo

2015-01-01

Quantum correlations in a composite system can be measured by resorting to a geometric approach, according to which the distance from the state of the system to a suitable set of classically correlated states is considered. Here we show that all distance functions, which respect natural assumptions of invariance under transposition, convexity, and contractivity under quantum channels, give rise to geometric quantifiers of quantum correlations which exhibit the peculiar freezing phenomenon, i.e., remain constant during the evolution of a paradigmatic class of states of two qubits each independently interacting with a non-dissipative decohering environment. Our results demonstrate from first principles that freezing of geometric quantum correlations is independent of the adopted distance and therefore universal. This finding paves the way to a deeper physical interpretation and future practical exploitation of the phenomenon for noisy quantum technologies. PMID:26053239

DIRECT CURRENT ELECTROMAGNETIC PUMP

DOEpatents

Barnes, A.H.

1957-11-01

An improved d-c electromagnetic pump is presented in which the poles, and consequently the magetic gap at the poles, are tapered to be wider at the upstream end. In addition, the cross section of the tube carryiQ the liquid metal is tapered so that the velocity of the pumped liquid increases in the downstream direction at a rate such that the counter-induced voltage in the liquid metal remains constant as it traverses the region between the poles. This configuration compensates for the distortion of the magnetic field caused by the induced voltage that would otherwise result in the lowering of the pumping capacity. This improved electromagnetic pump as practical application in the pumping of liquid metal coolants for nuclear reactors where conventional positive displacement pumps have proved unsatisfactory due to the high temperatures and the corrosive properties of the liquid metals involved.

Two distinct superconducting phases in LiFeAs

PubMed Central

Nag, P. K.; Schlegel, R.; Baumann, D.; Grafe, H.-J.; Beck, R.; Wurmehl, S.; Büchner, B.; Hess, C.

2016-01-01

A non-trivial temperature evolution of superconductivity including a temperature-induced phase transition between two superconducting phases or even a time-reversal symmetry breaking order parameter is in principle expected in multiband superconductors such as iron-pnictides. Here we present scanning tunnelling spectroscopy data of LiFeAs which reveal two distinct superconducting phases: at = 18 K a partial superconducting gap opens, evidenced by subtle, yet clear features in the tunnelling spectra, i.e. particle-hole symmetric coherence peak and dip-hump structures. At Tc = 16 K, these features substantiate dramatically and become characteristic of full superconductivity. Remarkably, the distance between the dip-hump structures and the coherence peaks remains practically constant in the whole temperature regimeT ≤ . This rules out the connection of the dip-hump structures to an antiferromagnetic spin resonance. PMID:27297474

The Body of the Text: Literacy's Corporeal Constant.

ERIC Educational Resources Information Center

Marvin, Carolyn

1994-01-01

Considers the role of bodily routines and practices as a component in the study of literacy. Examines a practice by physicians in the late 19th and early 20th centuries of binding fine or rare texts in human skin. Relates this embodied literacy practice to the transformation of medical practice from an oral to a textual discipline. (SR)

Investigation of the hydrochlorination of SiCl4

NASA Technical Reports Server (NTRS)

Mui, J. Y. P.

1983-01-01

A basic, experimental study on the hydrochlorination of silicon tetrachloride and metallurgical grade silicon with hydrogen gas to form trichlorosilane was carried out to greatly expand the range of reaction conditions. The equilibrium constant, K sub p, for the hydrochlorination reaction was measured as a function of temperature, pressure and concentration. The variation of the equilibrium constant as a function of temperature provided the measurement on the heat of reaction, delta H, by the Second Law Method. The value of delta H was measured to give 10.6 Kcal/mole. The equilibrium constant was also studied as a function of concentration. In agreement with the theory, the equilibrium constant remained constant with respect to the varying H2/SiCl4 feed ratios. On the other hand, the effect of pressure on the equilibrium constant was found to be more complex.

An evaluation of mouthguard requirements and dental injuries in New Zealand rugby union

PubMed Central

Quarrie, K; Gianotti, S; Chalmers, D; Hopkins, W

2005-01-01

Objectives: To document the effects of compulsory mouthguard wearing on rugby related dental injury claims made to ACC, the administrator of New Zealand's accident compensation scheme. Methods: An ecological study was conducted. Estimates of mouthguard wearing rates were available from prospective studies conducted in 1993, 2002, and 2003. Rugby related dental injury claims were available for the period 1995–2003. Player numbers were available from 1998. Mouthguard wearing was made compulsory during match play for rugby players at under 19 level and below at the beginning of the 1997 season, and for all grades of domestic rugby at the beginning of the 1998 season. Greater powers of enforcement were provided to referees at the beginning of the 2003 season. Results: The self reported rate of mouthguard use was 67% of player-weeks in 1993 and 93% in 2003. A total of 2644 claims was reported in 1995. There was a 43% (90% confidence interval 39% to 46%) reduction in dental claims from 1995 to 2003. On the reasonable assumption that the number of players and player-matches remained constant throughout the study period, the relative rate of injury claims for non-wearers versus wearers was 4.6 (90% confidence interval 3.8 to 5.6). The cumulative savings in claim costs compared with the cost per year if claim numbers had remained constant from 1995 is $1.87 million NZD. Conclusion: Although ecological studies have acknowledged weaknesses, the findings provide evidence that mouthguard use is a simple and effective injury prevention strategy for rugby players. The use of mouthguards for all players in both matches and contact practice situations is strongly recommended. PMID:16118304

A decade of change: an institutional experience with breast surgery in 1995 and 2005.

PubMed

Guth, Amber A; Shanker, Beth Ann; Roses, Daniel F; Axelrod, Deborah; Singh, Baljit; Toth, Hildegard; Shapiro, Richard L; Hiotis, Karen; Diflo, Thomas; Cangiarella, Joan F

2008-01-01

With the adoption of routine screening mammography, breast cancers are being diagnosed at earlier stages, with DCIS now accouting for 22.5% of all newly diagnosed breast cancers. This has been attributed to both increased breast cancer awareness and improvements in breast imaging techniques. How have these changes, including the increased use of image-guided sampling techniques, influenced the clinical practice of breast surgery? The institutional pathology database was queried for all breast surgeries, including breast reconstruction, performed in 1995 and 2005. Cosmetic procedures were excluded. The results were analysed utilizing the Chi-square test. Surgical indications changed during 10-year study period, with an increase in preoperatively diagnosed cancers undergoing definitive surgical management. ADH, and to a lesser extent, ALH, became indications for surgical excision. Fewer surgical biopsies were performed for indeterminate abnormalities on breast imaging, due to the introduction of stereotactic large core biopsy. While the rate of benign breast biopsies remained constant, there was a higher percentage of precancerous and DCIS cases in 2005. The overall rate of mastectomy decreased from 36.8% in 1995 to 14.5% in 2005. With the increase in sentinel node procedures, the rate of ALND dropped from 18.3% to 13.7%. Accompanying the increased recognition of early-stage cancers, the rate of positive ALND also decreased, from 43.3% to 25.0%. While the rate of benign breast biopsies has remained constant over a recent 10-year period, fewer diagnostic surgical image-guided biopsies were performed in 2005. A greater percentage of patients with breast cancer or preinvasive disease have these diagnoses determined before surgery. More preinvasive and Stage 0 cancers are undergoing surgical management. Earlier stage invasive cancers are being detected, reflected by the lower incidence of axillary nodal metastases.

A Decade of Change: An Institutional Experience with Breast Surgery in 1995 and 2005

PubMed Central

Guth, Amber A.; Shanker, Beth Ann; Roses, Daniel F.; Axelrod, Deborah; Singh, Baljit; Toth, Hildegard; Shapiro, Richard L.; Hiotis, Karen; Diflo, Thomas; Cangiarella, Joan F.

2008-01-01

Introduction: With the adoption of routine screening mammography, breast cancers are being diagnosed at earlier stages, with DCIS now accouting for 22.5% of all newly diagnosed breast cancers. This has been attributed to both increased breast cancer awareness and improvements in breast imaging techniques. How have these changes, including the increased use of image-guided sampling techniques, influenced the clinical practice of breast surgery? Methods: The institutional pathology database was queried for all breast surgeries, including breast reconstruction, performed in 1995 and 2005. Cosmetic procedures were excluded. The results were analysed utilizing the Chi-square test. Results: Surgical indications changed during 10-year study period, with an increase in preoperatively diagnosed cancers undergoing definitive surgical management. ADH, and to a lesser extent, ALH, became indications for surgical excision. Fewer surgical biopsies were performed for indeterminate abnormalities on breast imaging, due to the introduction of stereotactic large core biopsy. While the rate of benign breast biopsies remained constant, there was a higher percentage of precancerous and DCIS cases in 2005. The overall rate of mastectomy decreased from 36.8% in 1995 to 14.5% in 2005. With the increase in sentinel node procedures, the rate of ALND dropped from 18.3% to 13.7%. Accompanying the increased recognition of early-stage cancers, the rate of positive ALND also decreased, from 43.3% to 25.0%. Conclusions: While the rate of benign breast biopsies has remained constant over a recent 10-year period, fewer diagnostic surgical image-guided biopsies were performed in 2005. A greater percentage of patients with breast cancer or preinvasive disease have these diagnoses determined before surgery. More preinvasive and Stage 0 cancers are undergoing surgical management. Earlier stage invasive cancers are being detected, reflected by the lower incidence of axillary nodal metastases. PMID:21655372

Environmental state and tendencies of the Puerto Morelos CARICOMP site, Mexico.

PubMed

Rodríguez-Martínez, Rosa E; Ruíz-Rentería, Francisco; van Tussenbroek, Brigitta; Barba-Santos, Guadalupe; Escalante-Mancera, Edgar; Jordán-Garza, Guillermo; Jordán-Dahlgren, Eric

2010-10-01

The CARICOMP site at Puerto Morelos, Mexico was monitored from 1993 to 2005. No significant changes in air temperature, wind patterns, periodicity and quantity of rainfall, sea-surface temperature and water transparency were observed between sampling years. During the study four hurricane impacts were registered. At the coral reef site overall mean cover of fleshy algae (47%) and turf algae (36%) were high, whereas cover of corals (2%) and sponges (3%), and abundance of sea-urchins (0.04 org m(-2)) were consistently low. Gorgonians were dominant and showed changes in their community structure; the number of species increased from 1993 to 1995, their abundance decreased after Hurricane Roxanne (1995) and recovered by 2001. At four seagrass sites total community biomass remained constant (707.1-929.6 g dry m(-2)) but the above-ground biomass of the seagrass Syringodium filiforme and fleshy algae increased gradually. Total biomass (531-699 g dry m(-2)) and leaf productivity (0.89-1.56 g dry m(-2) d(-1)) of the seagrass Thalassia testudinum remained constant, but the species invested proportionally more biomass in above-ground leaf tissues at the end of the study. The minor hurricanes from 1993 until 2005 had no detectable impacts on the seagrass beds, however, the major Hurricane Wilma (October 2005) changed the community composition at three stations and caused complete burial of the vegetation at a coastal station. The gradual changes in the seagrass and reef communities recorded in the 12 years of continuous monitoring of the CARICOMP site may reflect the increased pollution caused by the rapid augment in urban and tourist developments along the coasts and inland from Puerto Morelos, coupled with poor water management practices.

Graduate Students' Perceptions of Professional Power in Social Work Practice

ERIC Educational Resources Information Center

Bundy-Fazioli, Kimberly; Quijano, Louise M.; Bubar, Roe

2013-01-01

The study of ways that professional power is perceived in social work practice is limited. This exploratory qualitative study analyzes second-year MSW students' perceptions of professional power in social work practice. This inquiry is guided by social constructivism and symbolic interactionism perspectives. The authors used constant comparison…

Best Practices Models for Implementing, Sustaining, and Using Instructional School Gardens in California

ERIC Educational Resources Information Center

Hazzard, Eric L.; Moreno, Elizabeth; Beall, Deborah L.; Zidenberg-Cherr, Sheri

2011-01-01

To ascertain best practices for schools implementing or sustaining instructional school gardens by interviewing key members in 10 schools with exemplary instructional school gardens programs in California. Practices of schools with exemplary instructional school gardens programs were analyzed by constant comparative analysis using qualitative data…

The Role of Theory in Practice.

ERIC Educational Resources Information Center

Pyfer, Jean L.

There are at least three ways in which educational theory can be used in practice: (1) to reexamine our traditional approaches, (2) to provide direction in future practice, and (3) to generate research. Reexamination of traditional approaches through analysis and utilization of theoretical methods is one means of promoting constant growth and…

Effective Second Language Writing. TESOL Classroom Practice Series

ERIC Educational Resources Information Center

Kasten, Susan, Ed.

2010-01-01

The classroom practices discussed in "Effective Second Language Writing" reflect various trends and methodologies; however, the underlying theme in this volume of the Classroom Practice Series is the need for clear and meaningful communication between ESL writers and their readers. While approaches differ, two core beliefs are constant: ESL…

Solid colloidal particles inducing coalescence in bitumen-in-water emulsions.

PubMed

Legrand, J; Chamerois, M; Placin, F; Poirier, J E; Bibette, J; Leal-Calderon, F

2005-01-04

Silica particles are dispersed in the continuous phase of bitumen-in-water emulsions. The mixture remains dispersed in quiescent storage conditions. However, rapid destabilization occurs once a shear is applied. Observations under the microscope reveal that the bitumen droplets form a colloidal gel and coalesce upon application of a shear. We follow the kinetic evolution of the emulsions viscosity, eta, at constant shear rate: eta remains initially constant and exhibits a dramatic increase after a finite time, tau. We study the influence of various parameters on the evolution of tau: bitumen droplet size and volume fraction, silica diameter and concentration, shear rate, etc.

The Flow of Ethnicity: Voices of Diverse High School Youth.

ERIC Educational Resources Information Center

Davidson, Ann Locke; And Others

This paper considers whether ethnicity is a social construction that is constantly being recreated in a nexus of shifting social relations rather than a set of perceptions and behaviors that remain constant and stem from a youth's membership in an ethnic group. Student responses about ethnicity from a larger study of student role and engagement in…

Infant stepping: a method to study the sensory control of human walking

PubMed Central

Yang, Jaynie F; Stephens, Marilee J; Vishram, Rosie

1998-01-01

Stepping responses were studied in infants between the ages of 10 days and 10 months while they were supported to step on a slowly moving treadmill belt. Surface electromyography (EMG) from muscles in the lower limb, force exerted by the feet on the treadmill belt, and the motion of the lower limbs were recorded. Two groups of infants were studied, those who had a small amount of daily practice in stepping and those who did not. Practice resulted in a dramatic increase in the incidence of stepping recorded in the laboratory, particularly for the periods between 1 and 6 months of age. The majority of infants showed clear alternation between the flexor and extensor muscles during walking, regardless of age. Co-contraction between flexors and extensors, estimated by the overlap in area between rectified and smoothed EMG from a muscle pair, was greater for some muscle groups in the infant compared with the adult. Practice resulted in a significantly lower co-contraction index for the tibialis anterior- quadriceps muscle pair. Practice did not affect the mean step cycle duration. Infants of all ages could step at a range of treadmill speeds by adjusting their step cycle duration. The relationship between the treadmill speed and cycle duration was well fitted by a power function, similar to those reported for intact cats and adult humans. The change in step cycle duration resulted almost entirely from a change in the extensor burst duration, whereas the flexor burst duration remained constant. Airstepping could be elicited in some infants. The cycle durations for airstepping were close to the shortest cycles recorded on the treadmill. In conclusion, the system for generating rhythmic, alternating activity of the lower limbs for stepping is clearly developed by birth. The stepping is sustained and regular, particularly if stepping practice is incorporated briefly each day. The infant population provides a good subject pool for studying the afferent control of walking in the human, before cerebral influences are fully developed. The characteristics and maturity of the system remain to be determined. PMID:9508851

Radii effect on the translation spring constant of force transducer beams

NASA Technical Reports Server (NTRS)

Scott, C. E.

1992-01-01

Multi-component strain-gage force transducer design requires the designer to determine the spring constant of the numerous beams or flexures incorporated in the transducer. The classical beam deflection formulae that are used in calculating these spring constants typically assume that the beam has a uniform moment of inertia along the entire beam length. In practice all beams have a radius at the end where the beam interfaces with the shoulder of the transducer, and on short beams in particular this increases the beam spring constant considerably. A Basic computer program utilizing numerical integration is presented to determine this effect.

Commuting fruit bats beneficially modulate their flight in relation to wind

PubMed Central

Sapir, Nir; Horvitz, Nir; Dechmann, Dina K. N.; Fahr, Jakob; Wikelski, Martin

2014-01-01

When animals move, their tracks may be strongly influenced by the motion of air or water, and this may affect the speed, energetics and prospects of the journey. Flying organisms, such as bats, may thus benefit from modifying their flight in response to the wind vector. Yet, practical difficulties have so far limited the understanding of this response for free-ranging bats. We tracked nine straw-coloured fruit bats (Eidolon helvum) that flew 42.5 ± 17.5 km (mean ± s.d.) to and from their roost near Accra, Ghana. Following detailed atmospheric simulations, we found that bats compensated for wind drift, as predicted under constant winds, and decreased their airspeed in response to tailwind assistance such that their groundspeed remained nearly constant. In addition, bats increased their airspeed with increasing crosswind speed. Overall, bats modulated their airspeed in relation to wind speed at different wind directions in a manner predicted by a two-dimensional optimal movement model. We conclude that sophisticated behavioural mechanisms to minimize the cost of transport under various wind conditions have evolved in bats. The bats’ response to the wind is similar to that reported for migratory birds and insects, suggesting convergent evolution of flight behaviours in volant organisms. PMID:24648227

Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks

PubMed Central

Vestergaard, Christian L.; Génois, Mathieu

2015-01-01

Stochastic simulations are one of the cornerstones of the analysis of dynamical processes on complex networks, and are often the only accessible way to explore their behavior. The development of fast algorithms is paramount to allow large-scale simulations. The Gillespie algorithm can be used for fast simulation of stochastic processes, and variants of it have been applied to simulate dynamical processes on static networks. However, its adaptation to temporal networks remains non-trivial. We here present a temporal Gillespie algorithm that solves this problem. Our method is applicable to general Poisson (constant-rate) processes on temporal networks, stochastically exact, and up to multiple orders of magnitude faster than traditional simulation schemes based on rejection sampling. We also show how it can be extended to simulate non-Markovian processes. The algorithm is easily applicable in practice, and as an illustration we detail how to simulate both Poissonian and non-Markovian models of epidemic spreading. Namely, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling. PMID:26517860

Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks.

PubMed

Vestergaard, Christian L; Génois, Mathieu

2015-10-01

Stochastic simulations are one of the cornerstones of the analysis of dynamical processes on complex networks, and are often the only accessible way to explore their behavior. The development of fast algorithms is paramount to allow large-scale simulations. The Gillespie algorithm can be used for fast simulation of stochastic processes, and variants of it have been applied to simulate dynamical processes on static networks. However, its adaptation to temporal networks remains non-trivial. We here present a temporal Gillespie algorithm that solves this problem. Our method is applicable to general Poisson (constant-rate) processes on temporal networks, stochastically exact, and up to multiple orders of magnitude faster than traditional simulation schemes based on rejection sampling. We also show how it can be extended to simulate non-Markovian processes. The algorithm is easily applicable in practice, and as an illustration we detail how to simulate both Poissonian and non-Markovian models of epidemic spreading. Namely, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling.

Trade-offs between forest carbon stocks and harvests in a steady state - A multi-criteria analysis.

PubMed

Pingoud, Kim; Ekholm, Tommi; Sievänen, Risto; Huuskonen, Saija; Hynynen, Jari

2018-03-15

This paper provides a perspective for comparing trade-offs between harvested wood flows and forest carbon stocks with different forest management regimes. A constant management regime applied to a forest area with an even age-class distribution leads to a steady state, in which the annual harvest and carbon stocks remain constant over time. As both are desirable - carbon stocks for mitigating climate change and harvests for the economic use of wood and displacing fossil fuels - an ideal strategy should be chosen from a set of management regimes that are Pareto-optimal in the sense of multi-criteria decision-making. When choosing between Pareto-optimal alternatives, the trade-off between carbon stock and harvests is unavoidable. This trade-off can be described e.g. in terms of carbon payback times or carbon returns. As numerical examples, we present steady-state harvest levels and carbon stocks in a Finnish boreal forest region for different rotation periods, thinning intensities and collection patterns for harvest residues. In the set of simulated management practices, harvest residue collection presents the most favorable trade-off with payback times around 30-40 years; while Pareto-optimal changes in rotation or thinnings exhibited payback times over 100 years, or alternatively carbon returns below 1%. By extending the rotation period and using less-intensive thinnings compared to current practices, the steady-state carbon stocks could be increased by half while maintaining current harvest levels. Additional cases with longer rotation periods should be also considered, but were here excluded due to the lack of reliable data on older forest stands. Copyright © 2018 Elsevier Ltd. All rights reserved.

Homework as a Family Literacy Practice: What Counts as Best Practices for Children Deemed as High Risk for Academic Failure Due to Socioeconomic Status

ERIC Educational Resources Information Center

Fox, Kathy R.

2016-01-01

Homework is a constant yet often controversial practice in homes and other settings. This study set out to determine answers to the question: "What practices were used to support children with homework in families deemed as at risk due to low socioeconomic factors?" Homework was examined as a common practice that routinely took place in…

Effects of practice schedule and task specificity on the adaptive process of motor learning.

PubMed

Barros, João Augusto de Camargo; Tani, Go; Corrêa, Umberto Cesar

2017-10-01

This study investigated the effects of practice schedule and task specificity based on the perspective of adaptive process of motor learning. For this purpose, tasks with temporal and force control learning requirements were manipulated in experiments 1 and 2, respectively. Specifically, the task consisted of touching with the dominant hand the three sequential targets with specific movement time or force for each touch. Participants were children (N=120), both boys and girls, with an average age of 11.2years (SD=1.0). The design in both experiments involved four practice groups (constant, random, constant-random, and random-constant) and two phases (stabilisation and adaptation). The dependent variables included measures related to the task goal (accuracy and variability of error of the overall movement and force patterns) and movement pattern (macro- and microstructures). Results revealed a similar error of the overall patterns for all groups in both experiments and that they adapted themselves differently in terms of the macro- and microstructures of movement patterns. The study concludes that the effects of practice schedules on the adaptive process of motor learning were both general and specific to the task. That is, they were general to the task goal performance and specific regarding the movement pattern. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantification aspects of constant pressure (ultra) high pressure liquid chromatography using mass-sensitive detectors with a nebulizing interface.

PubMed

Verstraeten, M; Broeckhoven, K; Lynen, F; Choikhet, K; Landt, K; Dittmann, M; Witt, K; Sandra, P; Desmet, G

2013-01-25

The present contribution investigates the quantitation aspects of mass-sensitive detectors with nebulizing interface (ESI-MSD, ELSD, CAD) in the constant pressure gradient elution mode. In this operation mode, the pressure is controlled and maintained at a set value and the liquid flow rate will vary according to the inverse mobile phase viscosity. As the pressure is continuously kept at the allowable maximum during the entire gradient run, the average liquid flow rate is higher compared to that in the conventional constant flow rate operation mode, thus shortening the analysis time. The following three mass-sensitive detectors were investigated: mass spectrometry detector (MS), evaporative light scattering detector (ELSD) and charged aerosol detector (CAD) and a wide variety of samples (phenones, polyaromatic hydrocarbons, wine, cocoa butter) has been considered. It was found that the nebulizing efficiency of the LC-interfaces of the three detectors under consideration changes with the increasing liquid flow rate. For the MS, the increasing flow rate leads to a lower peak area whereas for the ELSD the peak area increases compared to the constant flow rate mode. The peak area obtained with a CAD is rather insensitive to the liquid flow rate. The reproducibility of the peak area remains similar in both modes, although variation in system permeability compromises the 'long-term' reproducibility. This problem can however be overcome by running a flow rate program with an optimized flow rate and composition profile obtained from the constant pressure mode. In this case, the quantification remains reproducibile, despite any occuring variations of the system permeability. Furthermore, the same fragmentation pattern (MS) has been found in the constant pressure mode compared to the customary constant flow rate mode. Copyright © 2012 Elsevier B.V. All rights reserved.

Self-tuning bandpass filter

NASA Technical Reports Server (NTRS)

Deboo, G. J.; Hedlund, R. C. (Inventor)

1973-01-01

An electronic filter is described which simultaneously maintains a constant bandwidth and a constant center frequency gain as the input signal frequency varies, and remains self-tuning to that center frequency over a decade range. The filter utilizes a field effect transistor (FET) as a voltage variable resistance in the bandpass frequency determining circuit. The FET is responsive to a phase detector to achieve self-tuning.

Medical Services: Standards of Medical Fitness

DTIC Science & Technology

2002-03-28

Malfunction of the acoustic nerve. (Evaluate functional impairment of hearing under para 3–10.) c. Mastoiditis, chronic, with constant drainage from the...mastoid cavity, requiring frequent and prolonged medical care. d. Mastoiditis, chronic, following mastoidectomy, with constant drainage from the...d. Nephrectomy, when after treatment, there is infection or pathology in the remaining kidney. e. Nephrostomy, if drainage persists. f. Oophorectomy

Machine compliance in compression tests

NASA Astrophysics Data System (ADS)

Sousa, Pedro; Ivens, Jan; Lomov, Stepan V.

2018-05-01

The compression behavior of a material cannot be accurately determined if the machine compliance is not accounted prior to the measurements. This work discusses the machine compliance during a compressibility test with fiberglass fabrics. The thickness variation was measured during loading and unloading cycles with a relaxation stage of 30 minutes between them. The measurements were performed using an indirect technique based on the comparison between the displacement at a free compression cycle and the displacement with a sample. Relating to the free test, it has been noticed the nonexistence of machine relaxation during relaxation stage. Considering relaxation or not, the characteristic curves for a free compression cycle can be overlapped precisely in the majority of the points. For the compression test with sample, it was noticed a non-physical decrease of about 30 µm during the relaxation stage, what can be explained by the greater fabric relaxation in relation to the machine relaxation. Beyond the technique normally used, another technique was used which allows a constant thickness during relaxation. Within this second method, machine displacement with sample is simply subtracted to the machine displacement without sample being imposed as constant. If imposed as a constant it will remain constant during relaxation stage and it will suddenly decrease after relaxation. If constantly calculated it will decrease gradually during relaxation stage. Independently of the technique used the final result will remain unchanged. The uncertainty introduced by this imprecision is about ±15 µm.

Science Notes: Dilution of a Weak Acid

ERIC Educational Resources Information Center

Talbot, Christopher; Wai, Chooi Khee

2014-01-01

This "Science note" arose out of practical work involving the dilution of ethanoic acid, the measurement of the pH of the diluted solutions and calculation of the acid dissociation constant, K[subscript a], for each diluted solution. The students expected the calculated values of K[subscript a] to be constant but they found that the…

Identification of Weak Acids and Bases by Titration with Primary Standards. A Modern Version of an Old Analytical Chemistry Experiment.

ERIC Educational Resources Information Center

Thompson, Robert Q.

1988-01-01

Describes a laboratory exercise in which acid dissociation constants and molecular weights are extracted from sample data and the sample is identified. Emphasizes accurate volumetric work while bringing to practice the concepts of acid-base equilibria, activity coefficients, and thermodynamic constants. (CW)

Searching for realism, structure and agency in Actor Network Theory.

PubMed

Elder-Vass, Dave

2008-09-01

Superficially, Actor Network Theory (ANT) and critical realism (CR) are radically opposed research traditions. Written from a realist perspective, this paper asks whether there might be a basis for finding common ground between these two traditions. It looks in turn at the questions of realism, structure, and agency, analysing the differences between the two perspectives and seeking to identify what each might learn from the other. Overall, the paper argues that there is a great deal that realists can learn from actor network theory; yet ANT remains stunted by its lack of a depth ontology. It fails to recognize the significance of mechanisms, and of their dependence on emergence, and thus lacks both dimensions of the depth that is characteristic of critical realism's ontology. This prevents ANT from recognizing the role and powers of social structure; but on the other hand, realists would do well to heed ANT's call for us to trace the connections through which structures are constantly made and remade. A lack of ontological depth also underpins ANT's practice of treating human and non-human actors symmetrically, yet this remains a valuable provocation to sociologists who neglect non-human entities entirely.

To determine the end point of wet granulation by measuring powder energies and thermal properties.

PubMed

Dave, Rutesh H; Wu, Stephen H; Contractor, Labdhi D

2012-04-01

Wet granulation has been widely used in pharmaceutical industry as a tablet manufacturing process. However, end-point determination of wet granulation process has always remained a challenge. Many traditional methods are available for end-point determination, yet accuracy and reproducibility still remain a challenge. Microcrystalline cellulose, widely used as an excipient in pharmaceutical industry, was granulated using water. Wet mass was passed through sieve # 12 and dried till constant percentage loss on drying was obtained and dried granules were obtained. Wet and dried granules collected were subjected to basic flow energy, specific energy, bulk density, pressure drop, differential scanning calorimetry and effusivity measurements. Analysis of data revealed various stages of granule growth from initial seed formation by adding 200-400 g of water, granule growth was observed by adding 600-800 g of water and over wetting was observed at 1155 g of water. In this work, we have justified our work to properly identify and utilize this technique for practical purpose to correctly identify the end-point determination of microcrystalline cellulose and explain various principles underlying energies associated with powder and thermal measurements.

Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery

PubMed Central

Czyż, Stanisław H.; Moss, Sarah J.

2016-01-01

There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill. PMID:27547196

Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery.

PubMed

Czyż, Stanisław H; Moss, Sarah J

2016-01-01

There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill.

Constant negotiating: managing work-related musculoskeletal disorders while remaining at the workplace.

PubMed

Smith-Young, Joanne; Solberg, Shirley; Gaudine, Alice

2014-02-01

We used grounded theory to explore processes and strategies used by workers affected by work-related musculoskeletal disorders (WMSDs) while they remained in the workplace, and we developed a theory to describe the overall process. Participants included 25 workers affected by WMSDs who were currently employed in various workplaces in Newfoundland and Labrador, Canada. The theoretical model has five main phases: (a) becoming concerned, (b) getting medical help, (c) dealing with the workplace, (d) making adjustments to lifestyle, and (e) taking charge, each with separate subphases. Constant negotiating was the core variable that explained the overall process, with workers engaged in negotiations with others in occupational, health, and social contexts. Using a two-dimensional figure, we illustrate the negotiation strategies workers used. We discuss implications for health care, workplaces, education, and research for creating a culture of understanding and respect for injured workers who wish to remain working after developing WMSDs.

Anharmonic Potential Constants and Their Dependence Upon Bond Length

DOE R&D Accomplishments Database

Herschbach, D. R.; Laurie, V. W.

1961-01-01

Empirical study of cubic and quartic vibrational force constants for diatomic molecules shows them to be approximately exponential functions of internuclear distance. A family of curves is obtained, determined by the location of the bonded atoms in rows of the periodic table. Displacements between successive curves correspond closely to those in Badger's rule for quadratic force constants (for which the parameters are redetermined to accord with all data now available). Constants for excited electronic and ionic states appear on practically the same curves as those for the ground states. Predictions based on the diatomic correlations agree with the available cubic constants for bond stretching in polyatomic molecules, regardless of the type of bonding involved. Implications of these regularities are discussed. (auth)

A flowing partially penetrating well in a finite-thickness aquifer: a mixed-type initial boundary value problem

NASA Astrophysics Data System (ADS)

Chang, Chien-Chieh; Chen, Chia-Shyun

2003-02-01

An analytical approach using integral transform techniques is developed to deal with a well hydraulics model involving a mixed boundary of a flowing partially penetrating well, where constant drawdown is stipulated along the well screen and no-flux condition along the remaining unscreened part. The aquifer is confined of finite thickness. First, the mixed boundary is changed into a homogeneous Neumann boundary by discretizing the well screen into a finite number of segments, each of which at constant drawdown is subject to unknown a priori well bore flux. Then, the Laplace and the finite Fourier transforms are used to solve this modified model. Finally, the prescribed constant drawdown condition is reinstated to uniquely determine the well bore flux function, and to restore the relation between the solution and the original model. The transient and the steady-state solutions for infinite aquifer thickness can be derived from the semi-analytical solution, complementing the currently available dual integral solution. If the distance from the edge of the well screen to the bottom/top of the aquifer is 100 times greater than the well screen length, aquifer thickness can be assumed infinite for times of practical significance, and groundwater flow can reach a steady-state condition, where the well will continuously supply water under a constant discharge. However, if aquifer thickness is smaller, the well discharge decreases with time. The partial penetration effect is most pronounced in the vicinity of the flowing well, decreases with increasing horizontal distance, and vanishes at distances larger than 1-2 times the aquifer thickness divided by the square root of aquifer anisotropy. The horizontal hydraulic conductivity and the specific storage coefficient can be determined from vertically averaged drawdown as measured by fully penetrating observation wells. The vertical hydraulic conductivity can be determined from the well discharge under two particular partial penetration conditions.

Linear frictional forces cause orbits to neither circularize nor precess

NASA Astrophysics Data System (ADS)

Hamilton, B.; Crescimanno, M.

2008-06-01

For the undamped Kepler potential the lack of precession has historically been understood in terms of the Runge-Lenz symmetry. For the damped Kepler problem this result may be understood in terms of the generalization of Poisson structure to damped systems suggested recently by Tarasov (2005 J. Phys. A: Math. Gen. 38 2145). In this generalized algebraic structure the orbit-averaged Runge-Lenz vector remains a constant in the linearly damped Kepler problem to leading order in the damping coefficient. Beyond Kepler, we prove that, for any potential proportional to a power of the radius, the orbit shape and precession angle remain constant to leading order in the linear friction coefficient.

Hidden Markov Item Response Theory Models for Responses and Response Times.

PubMed

Molenaar, Dylan; Oberski, Daniel; Vermunt, Jeroen; De Boeck, Paul

2016-01-01

Current approaches to model responses and response times to psychometric tests solely focus on between-subject differences in speed and ability. Within subjects, speed and ability are assumed to be constants. Violations of this assumption are generally absorbed in the residual of the model. As a result, within-subject departures from the between-subject speed and ability level remain undetected. These departures may be of interest to the researcher as they reflect differences in the response processes adopted on the items of a test. In this article, we propose a dynamic approach for responses and response times based on hidden Markov modeling to account for within-subject differences in responses and response times. A simulation study is conducted to demonstrate acceptable parameter recovery and acceptable performance of various fit indices in distinguishing between different models. In addition, both a confirmatory and an exploratory application are presented to demonstrate the practical value of the modeling approach.

Biological decolourisation of wastewater from molasses fermentation by Trametes versicolor in an airlift reactor.

PubMed

Rioja, R; García, M T; Peña, M; González, G

2008-06-01

Continuous decolourisation of wastewater from molasses fermentation using mycelium of Trametes versicolor in pellets shape was performed in an airlift bioreactor (semi-pilot scale) with the aim of operating steadily for a long period, maintaining the colour removal activity. The influences of influent flow and glucose feed rate were tested. Induction of peroxidases secretion by Mn(2+) addition was also studied. The efficiency of the decolourisation process was followed by monitoring colour and enzymatic activities. The experimental results showed that continuous decolourisation in an airlift bioreactor can be considered a suitable alternative for treating molasses fermentation wastewater. A colour removal yield around 60% remained practically constant during 23 days under continuous operation. Laccase was found to be the main enzyme secreted by the strain, being responsible for the decolourisation process. Mn(2+) addition was not likely to induct manganese-dependent peroxidase secretion.

Effects of industrial pre-freezing processing and freezing handling on glucosinolates and antioxidant attributes in broccoli florets.

PubMed

Cai, Congxi; Miao, Huiying; Qian, Hongmei; Yao, Leishuan; Wang, Bingliang; Wang, Qiaomei

2016-11-01

The effects of industrial pre-freezing processing and freezing handling on the contents of glucosinolates and antioxidants (vitamin C, polyphenols, carotenoid and chlorophyll), as well as the antioxidant capacity in broccoli (Brassica oleracea L. var. italica) florets were investigated in the present study. Our results showed that the glucosinolate accumulations were significantly decreased after pre-freezing processing, whereas elevated levels of phenols, carotenoids, chlorophyll, and also antioxidant capacity were observed in frozen broccoli florets. The contents of vitamin C remained constant during above mentioned processing. In conclusion, the current industrial freezing processing method is a good practice for the preservation of main antioxidant nutrients in broccoli florets, although some improvements in pre-freezing processing, such as steam blanching and ice-water cooling, are needed to attenuate the decrease in glucosinolate content. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Computational Scheme To Evaluate Hamaker Constants of Molecules with Practical Size and Anisotropy.

PubMed

Hongo, Kenta; Maezono, Ryo

2017-11-14

We propose a computational scheme to evaluate Hamaker constants, A, of molecules with practical sizes and anisotropies. Upon the increasing feasibility of diffusion Monte Carlo (DMC) methods to evaluate binding curves for such molecules to extract the constants, we discussed how to treat the averaging over anisotropy and how to correct the bias due to the nonadditivity. We have developed a computational procedure for dealing with the anisotropy and reducing statistical errors and biases in DMC evaluations, based on possible validations on predicted A. We applied the scheme to cyclohexasilane molecule, Si 6 H 12 , used in "printed electronics" fabrications, getting A ≈ 105 ± 2 zJ, being in plausible range supported even by other possible extrapolations. The scheme provided here would open a way to use handy ab initio evaluations to predict wettabilities as in the form of materials informatics over broader molecules.

An effective online data monitoring and saving strategy for large-scale climate simulations

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

Xian, Xiaochen; Archibald, Rick; Mayer, Benjamin

Large-scale climate simulation models have been developed and widely used to generate historical data and study future climate scenarios. These simulation models often have to run for a couple of months to understand the changes in the global climate over the course of decades. This long-duration simulation process creates a huge amount of data with both high temporal and spatial resolution information; however, how to effectively monitor and record the climate changes based on these large-scale simulation results that are continuously produced in real time still remains to be resolved. Due to the slow process of writing data to disk,more » the current practice is to save a snapshot of the simulation results at a constant, slow rate although the data generation process runs at a very high speed. This study proposes an effective online data monitoring and saving strategy over the temporal and spatial domains with the consideration of practical storage and memory capacity constraints. Finally, our proposed method is able to intelligently select and record the most informative extreme values in the raw data generated from real-time simulations in the context of better monitoring climate changes.« less

An effective online data monitoring and saving strategy for large-scale climate simulations

DOE PAGES

Xian, Xiaochen; Archibald, Rick; Mayer, Benjamin; ...

2018-01-22

Large-scale climate simulation models have been developed and widely used to generate historical data and study future climate scenarios. These simulation models often have to run for a couple of months to understand the changes in the global climate over the course of decades. This long-duration simulation process creates a huge amount of data with both high temporal and spatial resolution information; however, how to effectively monitor and record the climate changes based on these large-scale simulation results that are continuously produced in real time still remains to be resolved. Due to the slow process of writing data to disk,more » the current practice is to save a snapshot of the simulation results at a constant, slow rate although the data generation process runs at a very high speed. This study proposes an effective online data monitoring and saving strategy over the temporal and spatial domains with the consideration of practical storage and memory capacity constraints. Finally, our proposed method is able to intelligently select and record the most informative extreme values in the raw data generated from real-time simulations in the context of better monitoring climate changes.« less

Issues of Motivation and Identity Positioning: Two Teachers' Motivational Practices for Engaging Immigrant Children in Learning Heritage Languages

ERIC Educational Resources Information Center

Kim, Jung-In

2017-01-01

This study investigates two Korean heritage language teachers' motivational practices in relation to their identity positioning as heritage language (HL) teachers. Constant-comparative analyses of teachers' interviews and classroom practices showed that the two teachers' identity positioning as HL teachers was partially shaped by their earlier…

Adolescent females and hormonal contraception: a retrospective study in primary care.

PubMed

Krishnamoorthy, Narayanan; Simpson, Colin D; Townend, John; Helms, Peter J; McLay, James S

2008-01-01

The aim of this study was to assess change in the number of adolescent females prescribed hormonal contraception in primary care following the publication in the United Kingdom of the Social Exclusion Unit report on Teenage Pregnancy. We conducted a retrospective observational study of 320 primary care practices in Scotland. Hormonal contraceptive prescribing to girls aged <16 years and those aged 16-19 years was assessed for April 1 to March 31 for the study years 2000-2001 to 2005-2006 from Scottish primary care practice data. Between 2000-2001 and 2005-2006, the proportion of girls aged <16 years and those 16-19 years who were prescribed hormonal contraception by their primary care physicians increased by 82% (p < .001) and 53% (p < .001) respectively. The increase became significant from age 12 years for the combined oral contraceptive, 14 years for the progestogen-only pill, and 15 years for depot progestogens. By 2005-2006, 2.9% of girls aged <16 years and 40.5% of those aged 16-19 years were prescribed some form of hormonal contraception by their primary care physicians. The small number of girls aged <12 years who were prescribed hormonal contraception remained constant over the study period. Since the publication in the United Kingdom of the Social Exclusion Unit Report on Teenage Pregnancy, there has been a significant increase in the number of female adolescents aged > or =12 years prescribed hormonal contraception by their primary care physicians. However the number of individuals prescribed hormonal contraception still remains relatively low in comparison to the reported levels of sexual activity among adolescents in the United Kingdom.

Constant covariance in local vertical coordinates for near-circular orbits

NASA Technical Reports Server (NTRS)

Shepperd, Stanley W.

1991-01-01

A method is presented for devising a covariance matrix that either remains constant or grows in keeping with the presence of a period error in a rotating local-vertical coordinate system. The solution presented may prove useful in the initialization of simulation covariance matrices for near-circular-orbit problems. Use is made of the Clohessy-Wiltshire equations and the travelling-ellipse formulation.

On the Henry constant and isosteric heat at zero loading in gas phase adsorption.

PubMed

Do, D D; Nicholson, D; Do, H D

2008-08-01

The Henry constant and the isosteric heat of adsorption at zero loading are commonly used as indicators of the strength of the affinity of an adsorbate for a solid adsorbent. It is assumed that (i) they are observable in practice, (ii) the Van Hoff's plot of the logarithm of the Henry constant versus the inverse of temperature is always linear and the slope is equal to the heat of adsorption, and (iii) the isosteric heat of adsorption at zero loading is either constant or weakly dependent on temperature. We show in this paper that none of these three points is necessarily correct, first because these variables might not be observable since they are outside the range of measurability; second that the linearity of the Van Hoff plot breaks down at very high temperature, and third that the isosteric heat versus loading is a strong function of temperature. We demonstrate these points using Monte Carlo integration and Monte Carlo simulation of adsorption of various gases on a graphite surface. Another issue concerning the Henry constant is related to the way the adsorption excess is defined. The most commonly used equation is the one that assumes that the void volume is the volume extended all the way to a boundary passing through the centres of the outermost solid atoms. With this definition the Henry constant can become negative at high temperatures. Although adsorption at these temperatures may not be practical because of the very low value of the Henry constant, it is more useful to define the Henry constant in such a way that it is always positive at all temperatures. Here we propose the use of the accessible volume; the volume probed by the adsorbate when it is in nonpositive regions of the potential, to calculate the Henry constant.

Teacher Practice Online: Sharing Wisdom, Opening Doors. School Reform Series

ERIC Educational Resources Information Center

Pointer Mace, Desiree H.

2009-01-01

Teachers know how complicated their work is. They constantly balance considerations of individual students with those of the group; they think about how past events affect today's lessons; and they constantly adapt and revise for future lessons. But few people ever get to see teachers' work in this way. The most energizing, relational,…

The Evolution of Teachers' Instructional Beliefs and Practices in High-Access-to-Technology Classrooms.

ERIC Educational Resources Information Center

Dwyer, David C.; And Others

Beginning in 1985, Apple Computer, Inc., and several school districts began a collaboration to examine the impact of computer saturation on instruction and learning in K-12 classrooms. The initial guiding question was simply put: What happens when teachers and students have constant access to technology? To provide "constant access,"…

The role of MEF2 transcription factors in dehydration and anoxia survival in Rana sylvatica skeletal muscle

PubMed Central

Hoyeck, Myriam P.; Hadj-Moussa, Hanane

2017-01-01

The wood frog (Rana sylvatica) can endure freezing of up to 65% of total body water during winter. When frozen, wood frogs enter a dormant state characterized by a cessation of vital functions (i.e., no heartbeat, blood circulation, breathing, brain activity, or movement). Wood frogs utilize various behavioural and biochemical adaptations to survive extreme freezing and component anoxia and dehydration stresses, including a global suppression of metabolic functions and gene expression. The stress-responsive myocyte enhancer factor-2 (MEF2) transcription factor family regulates the selective expression of genes involved in glucose transport, protein quality control, and phosphagen homeostasis. This study examined the role of MEF2A and MEF2C proteins as well as select downstream targets (glucose transporter-4, calreticulin, and muscle and brain creatine kinase isozymes) in 40% dehydration and 24 h anoxia exposure at the transcriptional, translational, and post-translational levels using qRT-PCR, immunoblotting, and subcellular localization. Mef2a/c transcript levels remained constant during dehydration and anoxia. Total, cytoplasmic, and nuclear MEF2A/C and phospho-MEF2A/C protein levels remained constant during dehydration, whereas a decrease in total MEF2C levels was observed during rehydration. Total and phospho-MEF2A levels remained constant during anoxia, whereas total MEF2C levels decreased during 24 h anoxia and P-MEF2C levels increased during 4 h anoxia. In contrast, cytoplasmic MEF2A levels and nuclear phospho-MEF2A/C levels were upregulated during anoxia. MEF2 downstream targets remained constant during dehydration and anoxia, with the exception of glut4 which was upregulated during anoxia. These results suggest that the upregulated MEF2 response reported in wood frogs during freezing may in part stem from their cellular responses to surviving prolonged anoxia, rather than dehydration, leading to an increase in GLUT4 expression which may have an important role during anoxia survival. PMID:29134152

Considering the Big Picture: How Significant Are Policy Initiatives?

ERIC Educational Resources Information Center

Fisher, Trevor

2011-01-01

Academic and journalistic comment is prioritised by the endless flood of policy initiatives. Yet these can be seen to be determined by long term intellectual frameworks which define why some issues remain constant and others remain marginal. Thus the dominance of academic provision and neglect of the vocational dates back to the nineteenth…

Constant curvature black holes in Einstein AdS gravity: Euclidean action and thermodynamics

NASA Astrophysics Data System (ADS)

Guilleminot, Pablo; Olea, Rodrigo; Petrov, Alexander N.

2018-03-01

We compute the Euclidean action for constant curvature black holes (CCBHs), as an attempt to associate thermodynamic quantities to these solutions of Einstein anti-de Sitter (AdS) gravity. CCBHs are gravitational configurations obtained by identifications along isometries of a D -dimensional globally AdS space, such that the Riemann tensor remains constant. Here, these solutions are interpreted as extended objects, which contain a (D -2 )-dimensional de-Sitter brane as a subspace. Nevertheless, the computation of the free energy for these solutions shows that they do not obey standard thermodynamic relations.

On the choice of boundary conditions in continuum models of continental deformation

NASA Technical Reports Server (NTRS)

Wdowinski, Shimon; O'Connell, Richard J.

1990-01-01

Recent studies of continental deformation have treated the lithosphere as a viscous medium and investigated the time evolution of the deformation caused by tectonic and buoyancy forces. This paper examines the differences between (1) continuum models that keep velocity boundary conditions constant with time and (2) models that keep stress boundary conditions constant with time. These differences are demonstrated by using a simple example of a continental lithosphere that is subjected to horizontal compression. The results show that in (2) the indentation velocity decreases with time, while in (1) the indentation velocity remains constant with time.

Elastic properties of uniaxial-fiber reinforced composites - General features

NASA Astrophysics Data System (ADS)

Datta, Subhendu; Ledbetter, Hassel; Lei, Ming

The salient features of the elastic properties of uniaxial-fiber-reinforced composites are examined by considering the complete set of elastic constants of composites comprising isotropic uniaxial fibers in an isotropic matrix. Such materials exhibit transverse-isotropic symmetry and five independent elastic constants in Voigt notation: C(11), C(33), C(44), C(66), and C(13). These C(ij) constants are calculated over the entire fiber-volume-fraction range 0.0-1.0, using a scattered-plane-wave ensemple-average model. Some practical elastic constants such as the principal Young moduli and the principal Poisson ratios are considered, and the behavior of these constants is discussed. Also presented are the results for the four principal sound velocities used to study uniaxial-fiber-reinforced composites: v(11), v(33), v(12), and v(13).

An audit of the global carbon budget: identifying and reducing sources of uncertainty

NASA Astrophysics Data System (ADS)

Ballantyne, A. P.; Tans, P. P.; Marland, G.; Stocker, B. D.

2012-12-01

Uncertainties in our carbon accounting practices may limit our ability to objectively verify emission reductions on regional scales. Furthermore uncertainties in the global C budget must be reduced to benchmark Earth System Models that incorporate carbon-climate interactions. Here we present an audit of the global C budget where we try to identify sources of uncertainty for major terms in the global C budget. The atmospheric growth rate of CO2 has increased significantly over the last 50 years, while the uncertainty in calculating the global atmospheric growth rate has been reduced from 0.4 ppm/yr to 0.2 ppm/yr (95% confidence). Although we have greatly reduced global CO2 growth rate uncertainties, there remain regions, such as the Southern Hemisphere, Tropics and Arctic, where changes in regional sources/sinks will remain difficult to detect without additional observations. Increases in fossil fuel (FF) emissions are the primary factor driving the increase in global CO2 growth rate; however, our confidence in FF emission estimates has actually gone down. Based on a comparison of multiple estimates, FF emissions have increased from 2.45 ± 0.12 PgC/yr in 1959 to 9.40 ± 0.66 PgC/yr in 2010. Major sources of increasing FF emission uncertainty are increased emissions from emerging economies, such as China and India, as well as subtle differences in accounting practices. Lastly, we evaluate emission estimates from Land Use Change (LUC). Although relative errors in emission estimates from LUC are quite high (2 sigma ~ 50%), LUC emissions have remained fairly constant in recent decades. We evaluate the three commonly used approaches to estimating LUC emissions- Bookkeeping, Satellite Imagery, and Model Simulations- to identify their main sources of error and their ability to detect net emissions from LUC.; Uncertainties in Fossil Fuel Emissions over the last 50 years.

Piezo-optic tensor of crystals from quantum-mechanical calculations.

PubMed

Erba, A; Ruggiero, M T; Korter, T M; Dovesi, R

2015-10-14

An automated computational strategy is devised for the ab initio determination of the full fourth-rank piezo-optic tensor of crystals belonging to any space group of symmetry. Elastic stiffness and compliance constants are obtained as numerical first derivatives of analytical energy gradients with respect to the strain and photo-elastic constants as numerical derivatives of analytical dielectric tensor components, which are in turn computed through a Coupled-Perturbed-Hartree-Fock/Kohn-Sham approach, with respect to the strain. Both point and translation symmetries are exploited at all steps of the calculation, within the framework of periodic boundary conditions. The scheme is applied to the determination of the full set of ten symmetry-independent piezo-optic constants of calcium tungstate CaWO4, which have recently been experimentally reconstructed. Present calculations unambiguously determine the absolute sign (positive) of the π61 constant, confirm the reliability of 6 out of 10 experimentally determined constants and provide new, more accurate values for the remaining 4 constants.

Piezo-optic tensor of crystals from quantum-mechanical calculations

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

Erba, A., E-mail: alessandro.erba@unito.it; Dovesi, R.; Ruggiero, M. T.

2015-10-14

An automated computational strategy is devised for the ab initio determination of the full fourth-rank piezo-optic tensor of crystals belonging to any space group of symmetry. Elastic stiffness and compliance constants are obtained as numerical first derivatives of analytical energy gradients with respect to the strain and photo-elastic constants as numerical derivatives of analytical dielectric tensor components, which are in turn computed through a Coupled-Perturbed-Hartree-Fock/Kohn-Sham approach, with respect to the strain. Both point and translation symmetries are exploited at all steps of the calculation, within the framework of periodic boundary conditions. The scheme is applied to the determination of themore » full set of ten symmetry-independent piezo-optic constants of calcium tungstate CaWO{sub 4}, which have recently been experimentally reconstructed. Present calculations unambiguously determine the absolute sign (positive) of the π{sub 61} constant, confirm the reliability of 6 out of 10 experimentally determined constants and provide new, more accurate values for the remaining 4 constants.« less

Mechanistic insight into ultrasound induced enhancement of simultaneous saccharification and fermentation of Parthenium hysterophorus for ethanol production.

PubMed

Singh, Shuchi; Agarwal, Mayank; Sarma, Shyamali; Goyal, Arun; Moholkar, Vijayanand S

2015-09-01

This paper presents investigations into mechanism of ultrasound assisted bioethanol synthesis using Parthenium hysterophorus biomass through simultaneous saccharification and fermentation (SSF) mode. Approach of coupling experimental results to mathematical model for SSF using Genetic Algorithm based optimization has been adopted. Comparison of model parameters for experiments with mechanical shaking and sonication (10% duty cycle) give an interesting mechanistic account of influence of ultrasound on SSF system. A 4-fold rise in ethanol and cell mass productivity is seen with ultrasound. The analysis reveals following facets of influence of ultrasound on SSF: increase in Monod constant for glucose for cell growth, maximal specific growth rate and inhibition constant of cell growth by glucose and reduction in specific cell death rate. Values of inhibition constant of cell growth by ethanol (K3E), and constants for growth associated (a) and non-growth associated (b) ethanol production remained unaltered with sonication. Beneficial effects of ultrasound are attributed to enhanced cellulose hydrolysis, enhanced trans-membrane transport of substrate and products as well as dilution of the toxic substances due to micro-convection induced by ultrasound. Intrinsic physiological functioning of cells remained unaffected by ultrasound as indicated by unaltered values of K3E, a and b. Copyright © 2015 Elsevier B.V. All rights reserved.

One Decade Later: Trends and Disparities in the Application of Post-Mastectomy Radiotherapy Since the Release of the American Society of Clinical Oncology Clinical Practice Guidelines

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

Dragun, Anthony E., E-mail: aedrag01@louisville.edu; Huang, Bin; Divison of Cancer Biostatistics, College of Public Health, University of Kentucky, Lexington, KY

2012-08-01

Purpose: In 2001 ASCO published practice guidelines for post mastectomy radiotherapy (PMRT). We analyzed factors that influence the receipt of radiotherapy therapy and trends over time. Methods and Materials: We analyzed 8889 women who underwent mastectomy as primary surgical treatment for stage II or III breast cancer between 1995 and 2008 using data from the Kentucky Cancer Registry. We categorized patients according to ASCO group: group 1, PMRT not routinely recommended (T2, N0); group 2, PMRT controversial/evidence insufficient (T1-2, N1); group 3, PMRT recommended or suggested (T3-4 or N2-3). Probability of receiving PMRT was assessed using logistic regression. Results: Overall,more » 24.0% of women received PMRT over the study period. The rates of PMRT for group 1, 2, and 3 were 7.5%, 19.5%, and 47.3%, respectively. Since 2001, there was an increase in the use of PMRT (from 21.1%-26.5%, P<.0001), which occurred mainly among group 3 members (from 40.8%-51.2%, P<.0001). The average rate remained constant in group 1 (from 7.1%-7.4%, P=.266) and decreased in group 2 (from 20.0%-18.1%, P<.0001). On multivariate analysis, the rate of PMRT was significantly lower for women aged >70 years (vs. younger), rural Appalachia (vs. non-Appalachia) populations, and Medicaid (vs. privately insured) patients. Conclusions: ASCO guidelines have influenced practice in an underserved state; however PMRT remains underused, even for highest-risk patients. Barriers exist for elderly, rural and poor patients, which independently predict for lack of adequate care. Updated guidelines are needed to clarify the use of PMRT for patients with T1-2, N1 disease.« less

Faculty turnover within academic pharmacy departments.

PubMed

Carter, Orly; Nathisuwan, Surakit; Stoddard, Gregory J; Munger, Mark A

2003-02-01

Pharmacy faculty manpower has been debated within the academic pharmacy community over the last several decades. Previous investigations studied job satisfaction among faculty members, but have not evaluated faculty retention and turnover among academic pharmacy departments. To evaluate retention and turnover rates in the departments of Pharmacy Practice and Basic Science (Pharmacology/Toxicology, Pharmaceutics, Medicinal Chemistry) over the last 5 years. Individual instructors and assistant, associate, and full professors across 80 colleges of pharmacy in the US were tracked between the years 1996 and 2001 using the American Association of Colleges of Pharmacy published rosters. Differences between departments were analyzed by year-stratified cross-tabulation table analysis. A greater percentage of Pharmacy Practice faculty resigned (10.6%) compared with Basic Science faculty (6.0%; percent ratio 1.76; 95% CI 1.58 to 1.95; p < 0.001), which remained constant across each academic year. Approximately 2.7 faculty members left their academic institutions per year in Pharmacy Practice compared with 1.1 faculty members in the aggregate of Basic Science departments. A higher percentage of women resigned in Pharmacy Practice (13.2%) than did men (8.7%; percent ratio 1.5; 95% CI 1.34 to 1.68; p < 0.001), despite a 1.3-fold male to female ratio. Likewise, regardless of a 4.1-fold male to female ratio in the Basic Science group, a higher percentage of women resigned (8.0%) than men (5.5%; percent ratio 1.45; 95% CI 1.18 to 1.78; p < 0.001). Over a 5-year period, Pharmacy Practice exhibited a higher turnover compared with Basic Science. Women displayed significantly higher turnover than men across all pharmacy academic departments. New retention approaches, especially for female faculty members, should be explored.

Emergency Radiology Practice Patterns: Shifts, Schedules, and Job Satisfaction.

PubMed

Hanna, Tarek N; Shekhani, Haris; Lamoureux, Christine; Mar, Hanna; Nicola, Refky; Sliker, Clint; Johnson, Jamlik-Omari

2017-03-01

To assess the practice environment of emergency radiologists with a focus on schedule, job satisfaction, and self-perception of health, wellness, and diagnostic accuracy. A survey drawing from prior radiology and health care shift-work literature was distributed via e-mail to national societies, teleradiology groups, and private practices. The survey remained open for 4 weeks in 2016, with one reminder. Data were analyzed using hypothesis testing and logistic regression modeling. Response rate was 29.6% (327/1106); 69.1% of respondents (n = 226) were greater than 40 years old, 73% (n = 240) were male, and 87% (n = 284) practiced full time. With regard to annual overnight shifts (NS): 36% (n = 118) did none, 24.9% (n = 81) did 182 or more, and 15.6% (n = 51) did 119. There was a significant association between average NS worked per year and both perceived negative health effects (P < .01) and negative impact on memory (P < .01). There was an inverse association between overall job enjoyment and number of annual NS (P < .05). The odds of agreeing to the statement "I enjoy my job" for radiologists who work no NS is 2.21 times greater than for radiologists who work at least 119 NS, when shift length is held constant. Radiologists with 11+ years of experience who work no NS or 1 to 100 NS annually have lower odds of feeling overwhelmed when compared with those working the same number of NS with <10 years' experience. There is significant variation in emergency radiology practice patterns. Annual NS burden is associated with lower job satisfaction and negative health self-perception. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Academic plastic surgery: a study of current issues and future challenges.

PubMed

Zetrenne, Eleonore; Kosins, Aaron M; Wirth, Garrett A; Bui, Albert; Evans, Gregory R D; Wells, James H

2008-06-01

The objectives of this study were (1) to evaluate the role of a full-time academic plastic surgeon, (2) to define the indicators predictive of a successful career in academic plastic surgery, and (3) to understand the current issues that will affect future trends in the practice of academic plastic surgery. A questionnaire was developed to evaluate the role of current full-time academic plastic surgeons and to understand the current issues and future challenges facing academic plastic surgery. Each plastic surgery program director in the United States was sent the survey for distribution among all full-time academic plastic surgeons. Over a 6-week period, responses from 143 full-time academic plastic surgeons (approximately 31%) were returned. Fifty-three percent of respondents had been academic plastic surgeons for longer than 10 years. Seventy-three percent of respondents defined academic plastic surgeons as clinicians who are teachers and researchers. However, 53% of respondents believed that academic plastic surgeons were not required to teach or practice within university hospitals/academic centers. The 3 factors reported most frequently as indicative of a successful career in academic plastic surgery were peer recognition, personal satisfaction, and program reputation. Dedication and motivation were the personal characteristics rated most likely to contribute to academic success. Forty-four percent of respondents were unable to identify future academic plastic surgeons from plastic surgery residency applicants, and 27% were not sure. Most (93%) of the respondents believed that academic surgery as practiced today will change. The overall job description of a full-time academic plastic surgeon remains unchanged (teacher and researcher). Whereas peer recognition, personal satisfaction, and program reputation were most frequently cited as indicative of a successful plastic surgery career, financial success was rated the least indicative. Similarly, whereas the personal characteristics of dedication and motivation were rated most likely to contribute to academic success, economic competence was rated least likely. Although the role of academic plastic surgeons remains constant, the practice of academic plastic surgery is evolving. As a result, the future clinical milieu of academic plastic surgeons and training programs is in question.

Using Electrophoretic Mobility Shift Assays to Measure Equilibrium Dissociation Constants: GAL4-p53 Binding DNA as a Model System

ERIC Educational Resources Information Center

Heffler, Michael A.; Walters, Ryan D.; Kugel, Jennifer F.

2012-01-01

An undergraduate biochemistry laboratory experiment is described that will teach students the practical and theoretical considerations for measuring the equilibrium dissociation constant (K[subscript D]) for a protein/DNA interaction using electrophoretic mobility shift assays (EMSAs). An EMSA monitors the migration of DNA through a native gel;…

On the Road to Quality: Turning Stumbling Blocks into Stepping Stones.

ERIC Educational Resources Information Center

Bonstingl, John Jay

1996-01-01

W. Edwards Deming's quality philosophy can help organizations develop collaborative, community-building leadership practices. This article outlines five personal practices of quality based on personal leadership, partnerships, a systems focus, a process orientation, and constant dedication to continuous improvement. Stumbling blocks can be…

A Study On School Practice Of Students In Field Teaching Master Of Arts Without Thesis

NASA Astrophysics Data System (ADS)

Guzel, Hatice

2007-04-01

Teacher training and the quality of the trained teachers include a large number of problems about the education system and practices that are constantly on agenda in Turkey. Teacher candidates should be well trained in order to possess certain qualifications.

Maritime Medicine.

ERIC Educational Resources Information Center

Estes, J. Worth

1996-01-01

Presents a fascinating look at the practice of medicine aboard commercial and military ships in the 18th and early 19th centuries. Contemporary medical practice believed all diseases were created by one of four "humors." In spite of this, and the constant presence of disease, most seamen led relatively healthy lives. (MJP)

Factors influencing the implementation of evidence in Chinese nursing practice.

PubMed

Cheng, Lei; Broome, Marion E; Feng, Sheng; Hu, Yan

2017-12-01

To explore the influencing factors from staff nurses, nurse managers, nursing directors and a physician involved in nursing evidence implementation in Mainland China. Although the need for evidence-based nursing is well recognised, continuous efforts are needed to strive for closing the gap from evidence to action. Previous studies have explored influencing factors from individual and organisational perspectives in Western countries. However, it remains unclear what the influences (i.e., context and culture) in the developing countries as China. A grounded theory design using in-depth individual interviews was conducted. Interviews with 56 participants from 24 evidence-based nursing implementation projects were conducted in Mainland China. Constant comparative analysis was used to discover the concepts describing the influencing factors during the implementation process. Factors that influenced implementation of evidence-based practice in the Chinese context were identified. These included the leaders of the projects, the nature of the evidence, practising nurses, patients involved in the projects, the system where the projects were implemented, as well as the influence from outside of the system. A variety of factors influencing evidence implementation in Chinese nursing context were identified and further explored from the perspective of different project leaders and culture influence. There is apparently a strong demand for a supportive system, targeted strategies to facilitate various evidence implementations and integrated core elements of evidence-based practice at the point care. The blurred boundaries and complexity of influencing factors call for a systematic and dynamic perspective during implementation. The competitive priorities emphasise the importance of integration between clinical nursing care and evidence-based practice. © 2017 John Wiley & Sons Ltd.

Theoretical Evaluation of the Transient Response of Constant Head and Constant Flow-Rate Permeability Tests

USGS Publications Warehouse

Zhang, M.; Takahashi, M.; Morin, R.H.; Esaki, T.

1998-01-01

A theoretical analysis is presented that compares the response characteristics of the constant head and the constant flowrate (flow pump) laboratory techniques for quantifying the hydraulic properties of geologic materials having permeabilities less than 10-10 m/s. Rigorous analytical solutions that describe the transient distributions of hydraulic gradient within a specimen are developed, and equations are derived for each method. Expressions simulating the inflow and outflow rates across the specimen boundaries during a constant-head permeability test are also presented. These solutions illustrate the advantages and disadvantages of each method, including insights into measurement accuracy and the validity of using Darcy's law under certain conditions. The resulting observations offer practical considerations in the selection of an appropriate laboratory test method for the reliable measurement of permeability in low-permeability geologic materials.

Acoustic myography as an indicator of force during sustained contractions of a small hand muscle.

PubMed

Goldenberg, M S; Yack, H J; Cerny, F J; Burton, H W

1991-01-01

To test the hypothesis that muscle sound amplitudes would remain constant during sustained submaximal isometric contractions, we recorded acoustic myograms from the abductor digiti minimi muscle in 12 subjects at 15, 25, 50, and 75% of a maximum voluntary contraction (MVC). Muscle sounds were detected with an omni-directional electret microphone encased in closed-cell foam and attached to the skin over the muscle. Acoustic amplitudes from the middle and end of the sustained contractions were compared with the amplitudes from the beginning of contractions to determine whether acoustic amplitudes varied in magnitude as force remained constant. Physiological tremor was eliminated from the acoustic signal by use of a Fourier truncation at 14 Hz. The amplitudes of the acoustic signal at a contraction intensity of 75% MVC remained constant, reflecting force production over time. At 50% MVC, the root-mean-square amplitude decreased from the beginning to the end of the contraction (P less than 0.05). Acoustic amplitudes increased over time at 15 and 25% MVC and were significantly higher at the end of the contractions than at the beginning (P less than 0.05). Alterations in the acoustic amplitude, which reflect changes in the lateral vibrations of the muscle, may be indicative of the different recruitment strategies used to maintain force during sustained isometric contractions.

Piecewise convexity of artificial neural networks.

PubMed

Rister, Blaine; Rubin, Daniel L

2017-10-01

Although artificial neural networks have shown great promise in applications including computer vision and speech recognition, there remains considerable practical and theoretical difficulty in optimizing their parameters. The seemingly unreasonable success of gradient descent methods in minimizing these non-convex functions remains poorly understood. In this work we offer some theoretical guarantees for networks with piecewise affine activation functions, which have in recent years become the norm. We prove three main results. First, that the network is piecewise convex as a function of the input data. Second, that the network, considered as a function of the parameters in a single layer, all others held constant, is again piecewise convex. Third, that the network as a function of all its parameters is piecewise multi-convex, a generalization of biconvexity. From here we characterize the local minima and stationary points of the training objective, showing that they minimize the objective on certain subsets of the parameter space. We then analyze the performance of two optimization algorithms on multi-convex problems: gradient descent, and a method which repeatedly solves a number of convex sub-problems. We prove necessary convergence conditions for the first algorithm and both necessary and sufficient conditions for the second, after introducing regularization to the objective. Finally, we remark on the remaining difficulty of the global optimization problem. Under the squared error objective, we show that by varying the training data, a single rectifier neuron admits local minima arbitrarily far apart, both in objective value and parameter space. Copyright © 2017 Elsevier Ltd. All rights reserved.

New Approach For Prediction Groundwater Depletion

NASA Astrophysics Data System (ADS)

Moustafa, Mahmoud

2017-01-01

Current approaches to quantify groundwater depletion involve water balance and satellite gravity. However, the water balance technique includes uncertain estimation of parameters such as evapotranspiration and runoff. The satellite method consumes time and effort. The work reported in this paper proposes using failure theory in a novel way to predict groundwater saturated thickness depletion. An important issue in the failure theory proposed is to determine the failure point (depletion case). The proposed technique uses depth of water as the net result of recharge/discharge processes in the aquifer to calculate remaining saturated thickness resulting from the applied pumping rates in an area to evaluate the groundwater depletion. Two parameters, the Weibull function and Bayes analysis were used to model and analyze collected data from 1962 to 2009. The proposed methodology was tested in a nonrenewable aquifer, with no recharge. Consequently, the continuous decline in water depth has been the main criterion used to estimate the depletion. The value of the proposed approach is to predict the probable effect of the current applied pumping rates on the saturated thickness based on the remaining saturated thickness data. The limitation of the suggested approach is that it assumes the applied management practices are constant during the prediction period. The study predicted that after 300 years there would be an 80% probability of the saturated aquifer which would be expected to be depleted. Lifetime or failure theory can give a simple alternative way to predict the remaining saturated thickness depletion with no time-consuming processes such as the sophisticated software required.

Practical deviations from Henry`s law for water/air partitioning of volatile organic compounds

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

Schabron, J.F.; Rovani, J.F. Jr.

A study was conducted to define parameters relating to the use of a down hole submersible photoionization detector (PID) probe to measure volatile organic compounds (VOCs) in an artificial headspace. The partitioning of toluene and trichloroethylene between water and air was studied as a function of analyte concentration and water temperature. The Henry`s law constant governing this partitioning represents an ideal condition at infinite dilution for a particular temperature. The results show that in practice. this partitioning is far from ideal. Conditions resulting in apparent, practical deviations from Henry`s law include temperature and VOC concentration. Thus, a single value ofmore » Henry`s law constant for a particular VOC such as toluene can provide only an approximation of concentration in the field. Detector response in saturated humidity environments as a function of water temperature and analyte concentration was studied also.« less

A new estimate of the Hubble constant using the Virgo cluster distance

NASA Astrophysics Data System (ADS)

Visvanathan, N.

The Hubble constant, which defines the size and age of the universe, remains substantially uncertain. Attention is presently given to an improved distance to the Virgo Cluster obtained by means of the 1.05-micron luminosity-H I width relation of spirals. In order to improve the absolute calibration of the relation, accurate distances to the nearby SMC, LMC, N6822, SEX A and N300 galaxies have also been obtained, on the basis of the near-IR P-L relation of the Cepheids. A value for the global Hubble constant of 67 + or 4 km/sec per Mpc is obtained.

Practical Algorithms for the Longest Common Extension Problem

NASA Astrophysics Data System (ADS)

Ilie, Lucian; Tinta, Liviu

The Longest Common Extension problem considers a string s and computes, for each of a number of pairs (i,j), the longest substring of s that starts at both i and j. It appears as a subproblem in many fundamental string problems and can be solved by linear-time preprocessing of the string that allows (worst-case) constant-time computation for each pair. The two known approaches use powerful algorithms: either constant-time computation of the Lowest Common Ancestor in trees or constant-time computation of Range Minimum Queries (RMQ) in arrays. We show here that, from practical point of view, such complicated approaches are not needed. We give two very simple algorithms for this problem that require no preprocessing. The first needs only the string and is significantly faster than all previous algorithms on the average. The second combines the first with a direct RMQ computation on the Longest Common Prefix array. It takes advantage of the superior speed of the cache memory and is the fastest on virtually all inputs.

Fundamentals of Managing Reference Collections

ERIC Educational Resources Information Center

Singer, Carol A.

2012-01-01

Whether a library's reference collection is large or small, it needs constant attention. Singer's book offers information and insight on best practices for reference collection management, no matter the size, and shows why managing without a plan is a recipe for clutter and confusion. In this very practical guide, reference librarians will learn:…

Teaching Practice: A Perspective on Inter-Text and Prior Knowledge

ERIC Educational Resources Information Center

Costley, Kevin C.; West, Howard G.

2012-01-01

The use of teaching practices that involve intertextual relationship discovery in today's elementary classrooms is increasingly essential to the success of young learners of reading. Teachers must constantly strive to expand their perspective of how to incorporate the dialogue included in prior knowledge assessment. Teachers must also consider how…

Towards Continuous Professional Development: Experiencing Group Reflection to Analyse Practice

ERIC Educational Resources Information Center

Sharmahd, Nima; Peeters, Jan; Bushati, Mirlinda

2018-01-01

Researchers and international organisations recognise that the quality of ECEC services is related to a professional and competent workforce. The latter should be part of a "competent system" that is capable of linking staff's initial good education to the possibility of constantly reflecting on ideas and practices. Continuous…

Becoming a "Good Coach"

ERIC Educational Resources Information Center

Jacobs, Frank; Claringbould, Inge; Knoppers, Annelies

2016-01-01

The purpose of this paper was to gain insight into how coaches problematized their coaching practices and the process in which they engaged to become what they perceived to be better coaches using a course based on critical reflective practice. We assumed that constant critical self-reflection would enable coaches to move closer to their…

Religious and Spiritual Beliefs and Practices of Persons with Chronic Pain

ERIC Educational Resources Information Center

Glover-Graf, Noreen M.; Marini, Irmo; Baker, Jeff; Buck, Tina

2007-01-01

Ninety-five persons receiving treatment for chronic pain were surveyed using the Spirituality and Chronic Pain Survey (SCPS). The survey included a pain assessment, a spiritual/religious practices assessment, and questions related to spiritual/religious beliefs and attitudes. Most participants reported experiencing constant, higher-level pain. The…

Researching the Effects of Frame-Focused Instruction on Second Language Acquisition

ERIC Educational Resources Information Center

Sokolova, Elena; Burmistrova, Anna

2012-01-01

In the context of globalization, the research of innovative teaching methods and techniques becomes relevant. The traditional teaching approach where the training of practice material is preceded by rule-presentation (explanation + mechanical form-oriented practice) does not meet the requirements of constantly developing rational language…

Sociocultural Contexts for the Early Development of Semiotic Production

ERIC Educational Resources Information Center

Braswell, Gregory S.

2006-01-01

Children constantly encounter signs during cultural practices, although many theories do not fully acknowledge sociocultural aspects of semiotic development. The author examines research on cultural practices and contexts in which children learn to produce signs involving representational drawing and pretend play. This work is contrasted with more…

Wind-invariant saltation heights imply linear scaling of aeolian saltation flux with shear stress.

PubMed

Martin, Raleigh L; Kok, Jasper F

2017-06-01

Wind-driven sand transport generates atmospheric dust, forms dunes, and sculpts landscapes. However, it remains unclear how the flux of particles in aeolian saltation-the wind-driven transport of sand in hopping trajectories-scales with wind speed, largely because models do not agree on how particle speeds and trajectories change with wind shear velocity. We present comprehensive measurements, from three new field sites and three published studies, showing that characteristic saltation layer heights remain approximately constant with shear velocity, in agreement with recent wind tunnel studies. These results support the assumption of constant particle speeds in recent models predicting linear scaling of saltation flux with shear stress. In contrast, our results refute widely used older models that assume that particle speed increases with shear velocity, thereby predicting nonlinear 3/2 stress-flux scaling. This conclusion is further supported by direct field measurements of saltation flux versus shear stress. Our results thus argue for adoption of linear saltation flux laws and constant saltation trajectories for modeling saltation-driven aeolian processes on Earth, Mars, and other planetary surfaces.

Wind-invariant saltation heights imply linear scaling of aeolian saltation flux with shear stress

PubMed Central

Martin, Raleigh L.; Kok, Jasper F.

2017-01-01

Wind-driven sand transport generates atmospheric dust, forms dunes, and sculpts landscapes. However, it remains unclear how the flux of particles in aeolian saltation—the wind-driven transport of sand in hopping trajectories—scales with wind speed, largely because models do not agree on how particle speeds and trajectories change with wind shear velocity. We present comprehensive measurements, from three new field sites and three published studies, showing that characteristic saltation layer heights remain approximately constant with shear velocity, in agreement with recent wind tunnel studies. These results support the assumption of constant particle speeds in recent models predicting linear scaling of saltation flux with shear stress. In contrast, our results refute widely used older models that assume that particle speed increases with shear velocity, thereby predicting nonlinear 3/2 stress-flux scaling. This conclusion is further supported by direct field measurements of saltation flux versus shear stress. Our results thus argue for adoption of linear saltation flux laws and constant saltation trajectories for modeling saltation-driven aeolian processes on Earth, Mars, and other planetary surfaces. PMID:28630907

Output characteristics of SASE-driven short wavelength FEL`s

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

Fawley, W.M.

This paper investigates various properties of the ``microspikes`` associated with self-amplified spontaneous emission (SASE) in a short wavelength free-electron laser (FEL). Using results from the 2-D numerical simulation code GINGER, we confirm theoretical predictions such as the convective group velocity in the exponential gain regime. In the saturated gain regime beyond the initial saturation, we find that the average radiation power continues to grow with an approximately linearly dependence upon undulator length. Moreover, the spectrum significantly broadens and shifts in wavelength to the redward direction, with{ital P(w)} approaching a constant, asymptotic value. This is in marked contrast to the exponentialmore » gain regime where the spectrum steadily narrows, {ital P(w)} grows, and the central wavelength remains constant with {ital z}. Via use of a spectrogram diagnostic {ital S(w,t)}, it appears that the radiation pattern in the saturated gain regime is composed of an ensemble of distinct ``sinews`` whose widths AA remain approximately constant but whose central wavelengths can ``chirp`` by varying a small extent with {ital t}.« less

Influence of ambient moisture on the compaction behavior of microcrystalline cellulose powder undergoing uni-axial compression and roller-compaction: a comparative study using near-infrared spectroscopy.

PubMed

Gupta, Abhay; Peck, Garnet E; Miller, Ronald W; Morris, Kenneth R

2005-10-01

This study evaluates the effect of variation in the ambient moisture on the compaction behavior of microcrystalline cellulose (MCC) powder. The study was conducted by comparing the physico-mechanical properties of, and the near infrared (NIR) spectra collected on, compacts prepared by roller compaction with those collected on simulated ribbons, that is, compacts prepared under uni-axial compression. Relative density, moisture content, tensile strength (TS), and Young modulus were used as key sample attributes for comparison. Samples prepared at constant roller compactor settings and feed mass showed constant density and a decrease in TS with increasing moisture content. Compacts prepared under uni-axial compression at constant pressure and compact mass showed the opposite effect, that is, density increased while TS remained almost constant with increasing moisture content. This suggests difference in the influence of moisture on the material under roller compaction, in which the roll gap (i.e., thickness and therefore density) remains almost constant, vs. under uni-axial compression, in which the thickness is free to change in response to the applied pressure. Key sample attributes were also related to the NIR spectra using multivariate data analysis by the partial least squares projection to latent structures (PLS). Good agreement was observed between the measured and the NIR-PLS predicted values for all key attributes for both, the roller compacted samples as well as the simulated ribbons. Copyright (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association

The future of surgery: autonomy or employment?

PubMed

Liepert, Amy; Babu, Maya; Leichtle, Stefan

2011-08-01

History has shown that the professions of medicine and surgery have been in constant evolution. Physicians, including the historical barber surgeons, often remained focused only on medical practice and patient care. As a result, the medical profession had a reactionary response to the financial and political circumstances that developed over time. Subsequently, physicians have worked in environments designed by nonphysicians lacking the benefit of medical insight. The most poignant example of this in the U.S. was the rapid development of private insurance and Medicare. Due to the surrounding financial and political forces, these programs rapidly changed the practice environment of medicine. Physicians found that they needed to participate in these programs to remain financially solvent. Various countries around the world have faced similar challenges of increasing health care cost. As populations expand, the need for care increases, but is limited by available resources. These global experiences can lend insight into the effects of different models and how variations may or may not work within the U.S. The effects of those systems demonstrate the importance of physician input into the development of new models. A long-standing unwritten rule in medicine has taught generations of physicians to avoid discussing reimbursement and health care politics. Yet, in order to recruit the brightest minds with a compassionate bedside manner, excellent judgment, and high vigilance toward patient care, medical professionals need to discuss topics related to reimbursement. The government, insurance company administrations, and other lobby interest groups freely express their interests in these issues. Physicians must engage in health care politics to ensure an adequate physician pool in the future to take care of patients. By influencing the structure of the health care system, including physician reimbursement, all patient care can be positively influenced.

Practice and transfer of the frequency structures of continuous isometric force.

PubMed

King, Adam C; Newell, Karl M

2014-04-01

The present study examined the learning, retention and transfer of task outcome and the frequency-dependent properties of isometric force output dynamics. During practice participants produced isometric force to a moderately irregular target pattern either under a constant or variable presentation. Immediate and delayed retention tests examined the persistence of practice-induced changes of force output dynamics and transfer tests investigated performance to novel (low and high) irregular target patterns. The results showed that both constant and variable practice conditions exhibited similar reductions in task error but that the frequency-dependent properties were differentially modified across the entire bandwidth (0-12Hz) of force output dynamics as a function of practice. Task outcome exhibited persistent properties on the delayed retention test whereas the retention of faster time scales processes (i.e., 4-12Hz) of force output was mediated as a function of frequency structure. The structure of the force frequency components during early practice and following a rest interval was characterized by an enhanced emphasis on the slow time scales related to perceptual-motor feedback. The findings support the proposition that there are different time scales of learning at the levels of task outcome and the adaptive frequency bandwidths of force output dynamics. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluating Differential Item Functioning in the English General Practice Patient Survey: Comparison of South Asian and White British Subgroups.

PubMed

Setodji, Claude M; Elliott, Marc N; Abel, Gary; Burt, Jenni; Roland, Martin; Campbell, John

2015-09-01

To evaluate two 5-item patient experience scales from the English General Practice (GP) Patient Survey for evidence of differential item functioning (DIF) given prior evidence of substantially worse reported health care experiences for South Asian compared with white British respondents. A national survey of English patients' primary care experiences. We used classic test and item response theory analysis to examine the possibility of DIF by patient ethnicity (South Asian, white British) after controlling for age, sex, health status, and quality of life in the English GP Patient Survey conducted in 2011/2012. Data were available for 873,051 respondents (818,219 white British/54,832 South Asian from 7795 English practices) who answered items relating to experiences of GP or nurses' care. Internal consistency reliability was high and similar for South Asian and white British patients. White British patients reported better average experiences than South Asians, but there was no evidence of DIF or different item response curves for white British and South Asian respondents, even in sensitivity analyses using matched samples. All communication items in the English GP Patient Survey showed similar South Asian versus white British differences, with no evidence of DIF. In contrast, differences due to scale use or expectations are typically variable rather than constant across scales. While other possibilities remain, these findings increase the likelihood that the observed negative responses of South Asian patients to this national survey reflect true differences in their experiences of care.

Post-deposition-annealing effect on current conduction in Al2O3 films formed by atomic layer deposition with H2O oxidant

NASA Astrophysics Data System (ADS)

Hiraiwa, Atsushi; Matsumura, Daisuke; Okubo, Satoshi; Kawarada, Hiroshi

2017-02-01

Atomic-layer-deposition (ALD) Al2O3 films are promising as gate insulators of non-Si semiconductor devices. Although they allow relatively small leakage currents just after deposition, ALD Al2O3 films formed at low temperatures are subject to high temperature during fabrication or operation of devices. Therefore, the effect of post-deposition annealing (PDA) on the properties of Al2O3 films is investigated in this study. ALD Al2O3 films formed using H2O oxidant at low temperatures are compacted by PDA, but their mass density and dielectric constant remain approximately unchanged or slightly decrease owing to the desorption of methyl groups contained in the films as impurities. In accordance with these results, the wet etching rate of Al2O3 films is not much reduced by PDA. The conduction current in ALD Al2O3 films formed on Si is reduced by PDA and becomes smaller than that in films formed at the same ALD temperatures as those of PDA. The conduction current for PDA temperatures above 250 °C, however, increases and, accordingly, spoils the merit of low-temperature ALD. Therefore, given that the dielectric constant of annealed films remains low, high-temperature ALD is practically more significant than applying PDA to low-temperature ALD Al2O3 films from the viewpoint of leakage current under the same thermal budget. Space-charge-controlled field emission analysis revealed that, at the aforementioned threshold temperature, PDA abruptly increases the Al2O3/SiO2 interfacial dipoles and simultaneously reduces the amount of the positive charge near the interface. The so-called negative-charge buildup by PDA might be caused by this decrease in the positive charge.

Sociodemographic inequalities in leisure-time physical activity and active commuting to school in Brazilian adolescents: National School Health Survey (PeNSE 2009, 2012, and 2015).

PubMed

Ferreira, Rodrigo Wiltgen; Varela, Andrea Ramirez; Monteiro, Luciana Zaranza; Häfele, César Augusto; Santos, Simone José Dos; Wendt, Andrea; Silva, Inácio Crochemore Mohnsam

2018-01-01

The objective of this study was to identify inequalities in leisure-time physical activity and active commuting to school in Brazilian adolescents, as well as trends according to gender, type of school, maternal schooling, and geographic region, from 2009 to 2015. This was a descriptive study based on data from the Brazilian National School Health Survey (PeNSE) in 2009, 2012, and 2015. Students were defined as active in their leisure time when they practiced at least 60 minutes of physical activity a day on five or more of the seven days prior to the interview. Active commuting to school was defined as walking or biking to school on the week prior to the interview. The outcomes were stratified by gender, type of school, maternal schooling, and geographic region. Inequalities were assessed by differences and ratios between the estimates, as well as summary inequality indices. The 2009, 2012, and 2015 surveys included 61,301, 61,145, and 51,192 schoolchildren, respectively. Prevalence of leisure-time physical activity was 13.8% in 2009, 15.9% in 2012, and 14.7% in 2015; the rates for active commuting to school were 70.6%, 61.7%, and 66.7%, respectively. Boys showed 10 percentage points higher prevalence of leisure-time physical activity and 5 points higher active commuting to school than girls. Children of mothers with more schooling showed a mean of 10 percentage points higher prevalence of leisure-time physical activity than children of mothers with the lowest schooling and some 30 percentage points lower in relation to active commuting to school. The observed inequalities remained constant over the course of the period. The study identified socioeconomic and gender inequalities that remained constant throughout the period and which were specific to each domain of physical activity.

20th century U.S. mineral prices decline in constant dollars

USGS Publications Warehouse

Sullivan, Daniel E.; Sznopek, John L.; Wagner, Lorie A.

2000-01-01

Price indexes developed by the U.S. Geological Survey (USGS) indicate that the long-term constant dollar price of key U.S. mineral raw materials declined over the last century, even though the need for mineral raw materials increased during the same period. Technologies and reduced production costs have allowed mineral production to remain profitable, while lower priced mineral products from domestic and foreign sources helped fuel growth in other sectors of the economy.

Recommended Values of the Fundamental Physical Constants: A Status Report

PubMed Central

Taylor, Barry N.; Cohen, E. Richard

1990-01-01

We summarize the principal advances made in the fundamental physical constants field since the completion of the 1986 CODATA least-squares adjustment of the constants and discuss their implications for both the 1986 set of recommended values and the next least-squares adjustment. In general, the new results lead to values of the constants with uncertainties 5 to 7 times smaller than the uncertainties assigned the 1986 values. However, the changes in the values themselves are less than twice the 1986 assigned one-standard-deviation uncertainties and thus are not highly significant. Although much new data has become available since 1986, three new results dominate the analysis: a value of the Planck constant obtained from a realization of the watt; a value of the fine-structure constant obtained from the magnetic moment anomaly of the electron; and a value of the molar gas constant obtained from the speed of sound in argon. Because of their dominant role in determining the values and uncertainties of many of the constants, it is highly desirable that additional results of comparable uncertainty that corroborate these three data items be obtained before the next adjustment is carried out. Until then, the 1986 CODATA set of recommended values will remain the set of choice. PMID:28179787

Electric Double-Layer Interaction between Dissimilar Charge-Conserved Conducting Plates.

PubMed

Chan, Derek Y C

2015-09-15

Small metallic particles used in forming nanostructured to impart novel optical, catalytic, or tribo-rheological can be modeled as conducting particles with equipotential surfaces that carry a net surface charge. The value of the surface potential will vary with the separation between interacting particles, and in the absence of charge-transfer or electrochemical reactions across the particle surface, the total charge of each particle must also remain constant. These two physical conditions require the electrostatic boundary condition for metallic nanoparticles to satisfy an equipotential whole-of-particle charge conservation constraint that has not been studied previously. This constraint gives rise to a global charge conserved constant potential boundary condition that results in multibody effects in the electric double-layer interaction that are either absent or are very small in the familiar constant potential or constant charge or surface electrochemical equilibrium condition.

Practical Recommendations for University Graduates' Readiness Formation to Occupational Mobility

ERIC Educational Resources Information Center

Yakhina, Zulfiya Sh.; Yakovlev, Sergey A.; Kozhevnikova, Natalya V.; Nuretdinova, Yuliya V.; Solovyeva, Natalya A.

2016-01-01

The research urgency is caused by the development of economic integration and demand for professionals able to adapt to constantly changing working conditions. The purpose of the paper is to develop practical recommendations on formation of University graduates' readiness to occupational mobility. A leading approach to the study is the…

Discursive Shadowing in Linguistic Ethnography. Situated Practices and Circulating Discourses in Multilingual Schools

ERIC Educational Resources Information Center

Dewilde, Joke; Creese, Angela

2016-01-01

We consider discursive shadowing as methodology in linguistic ethnography and how it refines our analyses of participants' situated practices. In addition to the constant and extended company the researcher and key participant keep with one another in the field, shadowing in a linguistic ethnographic approach includes the ubiquitous…

Kindergarten Teachers' Perspectives on Developmentally Appropriate Practices (DAP): A Study Conducted in Mumbai (India)

ERIC Educational Resources Information Center

Hegde, Archana V.; Cassidy, Deborah J.

2009-01-01

A qualitative study examining teachers' beliefs regarding developmentally appropriate practices was conducted in the city of Mumbai, India. Twelve kindergarten teacher's were interviewed for this study, and a constant comparative method was used to analyze the interviews. Six themes were identified within this study. The themes highlighted…

What Theorists Say They Do: A Brief Description of Theorists' Approaches

ERIC Educational Resources Information Center

Christie, Christina A.; Azzam, Tarek

2005-01-01

The purpose of this issue of "New Directions for Evaluation" is to examine, comparatively, the practical application of theorists' approaches to evaluation by examining four evaluations of the same case. The thought is that when asked to evaluate the same program (holding the case constant), the practical distinctions between theorists' approaches…

Recent developments and current issues in the epidemiology, diagnosis, and management of bacterial and fungal neonatal sepsis.

PubMed

Shane, Andi L; Stoll, Barbara J

2013-02-01

Identifying neonates with sepsis is complicated by variability in clinical presentation. The incidence of early onset sepsis (EOS) resulting from invasive group B streptococcal (GBS) infections has been notably reduced by the widespread delivery of intrapartum antibiotic prophylaxis. Rates of EOS attributable to non-GBS etiologies have remained constant, and ampicillin-resistant Escherichia coli has become more prevalent. Late-onset sepsis (LOS) attributable to gram-positive organisms including coagulase-negative Staphylococci and Staphylococcus aureus is associated with increased morbidity and mortality among premature infants. Invasive candidiasis is an emerging cause of LOS, especially among infants who receive broad-spectrum antimicrobial agents. Prophylactic fluconazole administration to very low-birth-weight (VLBW) neonates during the first 6 weeks of life prevents invasive candidiasis in neonatal intensive care units (NICU) with high rates of fungal infections. Targeted fluconazole prophylaxis may be beneficial in VLBW neonates who receive care in NICUs with lower rates of invasive fungal infections. Assessment of immune function, neutrophil markers, acute phase reactants, and utilization of sepsis screening scores may contribute to the management of sepsis. Maternal decolonization, antimicrobial stewardship, early enteral feeding, and optimal infection control practices are potential practical strategies for reducing the burden of neonatal sepsis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Estimating Energy Conversion Efficiency of Thermoelectric Materials: Constant Property Versus Average Property Models

NASA Astrophysics Data System (ADS)

Armstrong, Hannah; Boese, Matthew; Carmichael, Cody; Dimich, Hannah; Seay, Dylan; Sheppard, Nathan; Beekman, Matt

2017-01-01

Maximum thermoelectric energy conversion efficiencies are calculated using the conventional "constant property" model and the recently proposed "cumulative/average property" model (Kim et al. in Proc Natl Acad Sci USA 112:8205, 2015) for 18 high-performance thermoelectric materials. We find that the constant property model generally predicts higher energy conversion efficiency for nearly all materials and temperature differences studied. Although significant deviations are observed in some cases, on average the constant property model predicts an efficiency that is a factor of 1.16 larger than that predicted by the average property model, with even lower deviations for temperature differences typical of energy harvesting applications. Based on our analysis, we conclude that the conventional dimensionless figure of merit ZT obtained from the constant property model, while not applicable for some materials with strongly temperature-dependent thermoelectric properties, remains a simple yet useful metric for initial evaluation and/or comparison of thermoelectric materials, provided the ZT at the average temperature of projected operation, not the peak ZT, is used.

Quantum-gravity predictions for the fine-structure constant

NASA Astrophysics Data System (ADS)

Eichhorn, Astrid; Held, Aaron; Wetterich, Christof

2018-07-01

Asymptotically safe quantum fluctuations of gravity can uniquely determine the value of the gauge coupling for a large class of grand unified models. In turn, this makes the electromagnetic fine-structure constant calculable. The balance of gravity and matter fluctuations results in a fixed point for the running of the gauge coupling. It is approached as the momentum scale is lowered in the transplanckian regime, leading to a uniquely predicted value of the gauge coupling at the Planck scale. The precise value of the predicted fine-structure constant depends on the matter content of the grand unified model. It is proportional to the gravitational fluctuation effects for which computational uncertainties remain to be settled.

A Note on the Relationship between the Number of Indicators and Their Reliability in Detecting Regression Coefficients in Latent Regression Analysis

ERIC Educational Resources Information Center

Dolan, Conor V.; Wicherts, Jelte M.; Molenaar, Peter C. M.

2004-01-01

We consider the question of how variation in the number and reliability of indicators affects the power to reject the hypothesis that the regression coefficients are zero in latent linear regression analysis. We show that power remains constant as long as the coefficient of determination remains unchanged. Any increase in the number of indicators…

Automatic measurement of voice onset time using discriminative structured prediction.

PubMed

Sonderegger, Morgan; Keshet, Joseph

2012-12-01

A discriminative large-margin algorithm for automatic measurement of voice onset time (VOT) is described, considered as a case of predicting structured output from speech. Manually labeled data are used to train a function that takes as input a speech segment of an arbitrary length containing a voiceless stop, and outputs its VOT. The function is explicitly trained to minimize the difference between predicted and manually measured VOT; it operates on a set of acoustic feature functions designed based on spectral and temporal cues used by human VOT annotators. The algorithm is applied to initial voiceless stops from four corpora, representing different types of speech. Using several evaluation methods, the algorithm's performance is near human intertranscriber reliability, and compares favorably with previous work. Furthermore, the algorithm's performance is minimally affected by training and testing on different corpora, and remains essentially constant as the amount of training data is reduced to 50-250 manually labeled examples, demonstrating the method's practical applicability to new datasets.

Magnetic field effects on microwave absorbing materials

NASA Technical Reports Server (NTRS)

Goldberg, Ira; Hollingsworth, Charles S.; Mckinney, Ted M.

1991-01-01

The objective of this program was to gather information to formulate a microwave absorber that can work in the presence of strong constant direct current (DC) magnetic fields. The program was conducted in four steps. The first step was to investigate the electrical and magnetic properties of magnetic and ferrite microwave absorbers in the presence of strong magnetic fields. This included both experimental measurements and a literature survey of properties that may be applicable to finding an appropriate absorbing material. The second step was to identify those material properties that will produce desirable absorptive properties in the presence of intense magnetic fields and determine the range of magnetic field in which the absorbers remain effective. The third step was to establish ferrite absorber designs that will produce low reflection and adequate absorption in the presence of intense inhomogeneous static magnetic fields. The fourth and final step was to prepare and test samples of such magnetic microwave absorbers if such designs seem practical.

Retrospective analysis of survey data relating to the employment conditions of Canadian veterinary graduates for the years 2008 to 2013

PubMed Central

Jelinski, Murray D.; Lissemore, Kerry

2015-01-01

Six years of survey data generated from the “Annual New Graduate Survey” were collated and analyzed for trends. Canadian veterinary colleges graduated 14.9% more veterinarians in 2013 than 2008; 79.3% of graduates were female and this percentage was similar across all colleges (P = 0.51). The average base salary for new graduates remained constant at ~$69 000/annum for the years 2011 to 2013. However, the mean base salary of those employed in western Canada and Ontario was higher than that of employees in Quebec and the Maritimes (P < 0.001). There were no differences in the base salaries paid to males and females (P = 0.18) nor in what small animal, food animal, and equine practices were paying new graduates (P = 0.94). The 3 most common employee benefits were: a continuing education allowance, paid licensing fees, and paid malpractice insurance premiums. PMID:26483581

Principal Effects of Axial Load on Moment-Distribution Analysis of Rigid Structures

NASA Technical Reports Server (NTRS)

James, Benjamin Wylie

1935-01-01

This thesis presents the method of moment distribution modified to include the effect of axial load upon the bending moments. This modification makes it possible to analyze accurately complex structures, such as rigid fuselage trusses, that heretofore had to be analyzed by approximate formulas and empirical rules. The method is simple enough to be practicable even for complex structures, and it gives a means of analysis for continuous beams that is simpler than the extended three-moment equation now in common use. When the effect of axial load is included, it is found that the basic principles of moment distribution remain unchanged, the only difference being that the factors used, instead of being constants for a given member, become functions of the axial load. Formulas have been developed for these factors, and curves plotted so that their applications requires no more work than moment distribution without axial load. Simple problems have been included to illustrate the use of the curves.

Tensor perturbations during inflation in a spatially closed Universe

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

Bonga, Béatrice; Gupt, Brajesh; Yokomizo, Nelson, E-mail: bpb165@psu.edu, E-mail: bgupt@gravity.psu.edu, E-mail: yokomizo@gravity.psu.edu

2017-05-01

In a recent paper [1], we studied the evolution of the background geometry and scalar perturbations in an inflationary, spatially closed Friedmann-Lemaȋtre-Robertson-Walker (FLRW) model having constant positive spatial curvature and spatial topology S{sup 3}. Due to the spatial curvature, the early phase of slow-roll inflation is modified, leading to suppression of power in the scalar power spectrum at large angular scales. In this paper, we extend the analysis to include tensor perturbations. We find that, similarly to the scalar perturbations, the tensor power spectrum also shows suppression for long wavelength modes. The correction to the tensor spectrum is limited tomore » the very long wavelength modes, therefore the resulting observable CMB B-mode polarization spectrum remains practically the same as in the standard scenario with flat spatial sections. However, since both the tensor and scalar power spectra are modified, there are scale dependent corrections to the tensor-to-scalar ratio that leads to violation of the standard slow-roll consistency relation.« less

Giant dielectric response in (Sr, Sb) codoped CaCu3Ti4O12 ceramics: A novel approach

NASA Astrophysics Data System (ADS)

Pradhan, M. K.; Rao, T. Lakshmana; Karna, Lipsarani; Dash, S.

2018-04-01

The CaCu3Ti4O12 (CCTO) remains as the best material for practical applications due to its high dielectric constant. To improve further the dielectric properties of CCTO to several orders in magnitude, a novel approach is adopted by codoping of Sr, Sb ions. The ceramic samples were fabricated by the conventional solid state route. The structure, morphology and detail dielectric properties were investigated systematically. All the samples crystalizes in a cubic symmetry with Im-3 space group. Sr substituted in Ca site can effectively suppress the grain growth, achieving a fine grained ceramic structure; however the grain size decreased slightly as Sb concentration increased further; whereas the dielectric permittivity of the ceramics increased drastically. The giant dielectric response was considered to be closely related with a reduction in the potential barrier height at grain boundaries (GBs) supported by the reduction in the activation energy for the conduction process.

Not sensitive, yet less biased: A signal detection theory perspective on mindfulness, attention, and recognition memory.

PubMed

Rosenstreich, Eyal; Ruderman, Lital

2016-07-01

The practice of mindfulness has been argued to increase attention control and improve memory performance. However, it was recently suggested that the effect of mindfulness on memory may be due to a shift in response-bias, rather than to an increase in memory-sensitivity. The present study examined the mindfulness-attention-memory triad. Participants filled in the five-facets of mindfulness questionnaire, and completed two recognition blocks; in the first attention was full, whereas in the second attention was divided during the encoding of information. It was found that the facet of non-judging (NJ) moderated the impact of attention on memory, such that responses of high NJ participants were less biased and remained constant even when attention was divided. Facets of mindfulness were not associated with memory sensitivity. These findings suggest that mindfulness may affect memory through decision making processes, rather than through directing attentional resources to the encoding of information. Copyright © 2016 Elsevier Inc. All rights reserved.

Hydroxyapatite with Permanent Electrical Polarization: Preparation, Characterization, and Response against Inorganic Adsorbates.

PubMed

Rivas, Manuel; Del Valle, Luis J; Armelin, Elaine; Bertran, Oscar; Turon, Pau; Puiggalí, Jordi; Alemán, Carlos

2018-04-16

Permanently polarized hydroxyapatite (HAp) particles have been prepared by applying a constant DC of 500 V at 1000 °C for 1 h to the sintered mineral. This process causes important chemical changes, as the formation of OH - defects (vacancies), the disappearance of hydrogenophosphate ions at the mineral surface layer, and structural variations reflected by the increment of the crystallinity. As a consequence, the electrochemical properties and electrical conductivity of the polarized mineral increase noticeably compared with as-prepared and sintered samples. Moreover, these increments remain practically unaltered after several months. In addition, permanent polarization favours significantly the ability of HAp to adsorb inorganic bioadsorbates in comparison with as-prepared and sintered samples. The adsorbates cause a significant increment of the electrochemical stability and electrical conductivity with respect to bare polarized HAp, which may have many implications for biomedical applications of permanently polarized HAp. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 6121 - Information Collection; Submission for OMB Review, Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-03

... used by NCCC projects and partnerships office to collect project performance data. Type of Review: New... year. Assuming the distribution of project types remains constant, the number of survey sections...

Southern pulpwood production, 1981

Treesearch

Cecil C. Hutchins

1982-01-01

Southern pulpwood production has remained almost constant for the past 3 years. In 1981, production totaled 54.3 million cords with softwood roundwood accounting for about 50 percent, hardwood roundwood 18 percent, and mill byproducts 32 percent.

The EAP Part of Personnel Function.

ERIC Educational Resources Information Center

Delaney, Thomas J., Jr.

1987-01-01

Substance abuse among workers and its interference with job performance has remained constant over the past 15 years. Employee assistance programs educate the public, screen referrals, and provide feedback on how employees are progressing. (JOW)

The controlled growth of GaN nanowires.

PubMed

Hersee, Stephen D; Sun, Xinyu; Wang, Xin

2006-08-01

This paper reports a scalable process for the growth of high-quality GaN nanowires and uniform nanowire arrays in which the position and diameter of each nanowire is precisely controlled. The approach is based on conventional metalorganic chemical vapor deposition using regular precursors and requires no additional metal catalyst. The location, orientation, and diameter of each GaN nanowire are controlled using a thin, selective growth mask that is patterned by interferometric lithography. It was found that use of a pulsed MOCVD process allowed the nanowire diameter to remain constant after the nanowires had emerged from the selective growth mask. Vertical GaN nanowire growth rates in excess of 2 mum/h were measured, while remarkably the diameter of each nanowire remained constant over the entire (micrometer) length of the nanowires. The paper reports transmission electron microscopy and photoluminescence data.

Cosmological perturbations through a non-singular ghost-condensate/Galileon bounce

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

Battarra, Lorenzo; Koehn, Michael; Lehners, Jean-Luc

2014-07-01

We study the propagation of super-horizon cosmological perturbations in a non-singular bounce spacetime. The model we consider combines a ghost condensate with a Galileon term in order to induce a ghost-free bounce. Our calculation is performed in harmonic gauge, which ensures that the linearized equations of motion remain well-defined and non-singular throughout. We find that, despite the fact that near the bounce the speed of sound becomes imaginary, super-horizon curvature perturbations remain essentially constant across the bounce. In fact, we show that there is a time close to the bounce where curvature perturbations of all wavelengths are required to bemore » momentarily exactly constant. We relate our calculations to those performed in other gauges, and comment on the relation to previous results in the literature.« less

Effect of gas adsorption on acoustic wave propagation in MFI zeolite membrane materials: experiment and molecular simulation.

PubMed

Manga, Etoungh D; Blasco, Hugues; Da-Costa, Philippe; Drobek, Martin; Ayral, André; Le Clezio, Emmanuel; Despaux, Gilles; Coasne, Benoit; Julbe, Anne

2014-09-02

The present study reports on the development of a characterization method of porous membrane materials which consists of considering their acoustic properties upon gas adsorption. Using acoustic microscopy experiments and atomistic molecular simulations for helium adsorbed in a silicalite-1 zeolite membrane layer, we showed that acoustic wave propagation could be used, in principle, for controlling the membranes operando. Molecular simulations, which were found to fit experimental data, showed that the compressional modulus of the composite system consisting of silicalite-1 with adsorbed He increases linearly with the He adsorbed amount while its shear modulus remains constant in a large range of applied pressures. These results suggest that the longitudinal and Rayleigh wave velocities (VL and VR) depend on the He adsorbed amount whereas the transverse wave velocity VT remains constant.

Effects of heat conduction on artificial viscosity methods for shock capturing

DOE PAGES

Cook, Andrew W.

2013-12-01

Here we investigate the efficacy of artificial thermal conductivity for shock capturing. The conductivity model is derived from artificial bulk and shear viscosities, such that stagnation enthalpy remains constant across shocks. By thus fixing the Prandtl number, more physical shock profiles are obtained, only on a larger scale. The conductivity model does not contain any empirical constants. It increases the net dissipation of a computational algorithm but is found to better preserve symmetry and produce more robust solutions for strong-shock problems.

Vertical Stratification of Soil Phosphorus as a Concern for Dissolved Phosphorus Runoff in the Lake Erie Basin.

PubMed

Baker, David B; Johnson, Laura T; Confesor, Remegio B; Crumrine, John P

2017-11-01

During the re-eutrophication of Lake Erie, dissolved reactive phosphorus (DRP) loading and concentrations to the lake have nearly doubled, while particulate phosphorus (PP) has remained relatively constant. One potential cause of increased DRP concentrations is P stratification, or the buildup of soil-test P (STP) in the upper soil layer (<5 cm). Stratification often accompanies no-till and mulch-till practices that reduce erosion and PP loading, practices that have been widely implemented throughout the Lake Erie Basin. To evaluate the extent of P stratification in the Sandusky Watershed, certified crop advisors were enlisted to collect stratified soil samples (0-5 or 0-2.5 cm) alongside their normal agronomic samples (0-20 cm) ( = 1758 fields). The mean STP level in the upper 2.5 cm was 55% higher than the mean of agronomic samples used for fertilizer recommendations. The amounts of stratification were highly variable and did not correlate with agronomic STPs (Spearman's = 0.039, = 0.178). Agronomic STP in 70% of the fields was within the buildup or maintenance ranges for corn ( L.) and soybeans [ (L.) Merr.] (0-46 mg kg Mehlich-3 P). The cumulative risks for DRP runoff from the large number of fields in the buildup and maintenance ranges exceeded the risks from fields above those ranges. Reducing stratification by a one-time soil inversion has the potential for larger and quicker reductions in DRP runoff risk than practices related to drawing down agronomic STP levels. Periodic soil inversion and mixing, targeted by stratified STP data, should be considered a viable practice to reduce DRP loading to Lake Erie. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

On the Ground in Afghanistan: Counterinsurgency in Practice

DTIC Science & Technology

2012-01-01

without earning the enmity of rival factions. For Coalition forces, the political fault lines are not clear, and there is constant danger of getting drawn...Province, rival factions tried constantly to use their access to Coalition troops as leverage against their local enemies. U.S. forces had allied with...learned that it was important to maintain a light footprint in order to gain access to the population; otherwise, a team’s actions could threaten local

Clausius-Clapeyron Equation and Saturation Vapour Pressure: Simple Theory Reconciled with Practice

ERIC Educational Resources Information Center

Koutsoyiannis, Demetris

2012-01-01

While the Clausius-Clapeyron equation is very important as it determines the saturation vapour pressure, in practice it is replaced by empirical, typically Magnus-type, equations which are more accurate. It is shown that the reduced accuracy reflects an inconsistent assumption that the latent heat of vaporization is constant. Not only is this…

Knowledge and Practice of Nursing Staff towards Infection Control Measures in the Palestinian Hospitals

ERIC Educational Resources Information Center

Fashafsheh, Imad; Ayed, Ahmad; Eqtait, Faeda; Harazneh, Lubna

2015-01-01

Health care professionals are constantly exposed to microorganisms. Many of which can cause serious or even lethal infections. Nurses in particular are often exposed to various infections during the course of carrying out their nursing activities. Therefore nurses should have sound knowledge and strict adherence to infection control practice. Aim…

Comparison of the Efficiency of Two Flashcard Drill Methods on Children's Reading Performance

ERIC Educational Resources Information Center

Joseph, Laurice; Eveleigh, Elisha; Konrad, Moira; Neef, Nancy; Volpe, Robert

2012-01-01

The purpose of this study was to extend prior flashcard drill and practice research by holding instructional time constant and allowing learning trials to vary. Specifically, the authors aimed to determine whether an incremental rehearsal method or a traditional drill and practice method was most efficient in helping 5 first-grade children read,…

Using the Real-Time Instructor Observing Tool (RIOT) for Reflection on Teaching Practice

ERIC Educational Resources Information Center

Paul, Cassandra; West, Emily

2018-01-01

As physics educators, we are constantly looking for ways to improve our practice. There are many different kinds of professional development opportunities that have been shown to help us with this endeavor. We can seek assistance from professionals, like mentor teachers or centers for faculty development, we can attend workshops to learn new…

Three Korean Heritage Language Teachers' Identities, Their Identification of Their Students, and Their Instructional Practices

ERIC Educational Resources Information Center

Kim, Jung-In; Kim, Miseon

2016-01-01

This study examined the instructional focuses and practices of three Korean heritage language (HL) teachers in community-based HL schools related not only to their constructed identities as HL teachers, but also to their students. Constant-comparative analyses of interviews and classroom observations across the three teacher cases showed that each…

Meditation for adults with haematological malignancies.

PubMed

Salhofer, Ines; Will, Andrea; Monsef, Ina; Skoetz, Nicole

2016-02-03

Malignant neoplasms of the lymphoid or myeloid cell lines including lymphoma, leukaemia and myeloma are referred to as haematological malignancies. Complementary and alternative treatment options such as meditation practice or yoga are becoming popular by treating all aspects of the disease including physical and psychological symptoms. However, there is still unclear evidence about meditation's effectiveness, and how its practice affects the lives of haematologically-diseased patients. This review aims to assess the benefits and harms of meditation practice as an additional treatment to standard care for adults with haematological malignancies. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 8, 2015), MEDLINE (1950 to August 2015), databases of ongoing trials, the metaRegister of Controlled Trials (mRCT) (http://www.controlled-trials.com/mrct/), conference proceedings of annual meetings of: the American Society of Hematology; American Society of Clinical Oncology; European Hematology Association; European Congress for Integrative Medicine; and Global Advances in Health and Medicine (2010 to 2015). We included randomised controlled trials (RCTs) using meditation practice for adult patients with haematological malignancies. Two review authors independently extracted data from eligible studies and assessed the risk of bias according to predefined criteria. We evaluated quality of life and depression. The other outcomes of overall survival, anxiety, fatigue, quality of sleep and adverse events could not be evaluated, because they were not assessed in the included trial. We included only one small trial published as an abstract article. The included study investigated the effects of meditation practice on patients newly hospitalised with acute leukaemia. Ninety-one participants enrolled in the study, but only 42 participants remained in the trial throughout the six-month follow-up period and were eligible for analysis. There was no information provided about the average age and sex of the study population. We found a high risk for attrition bias and unclear risk for reporting bias, performance and detection bias because of missing data due to abstract publication only, thus we judged the overall risk of bias as high. According to the GRADE criteria, we judged the overall quality of the body of evidence for all predefined outcomes as 'very low', due to the extent of missing data on the study population, and the small sample size.As the abstract publication did not provide numbers and results except P values, we are not able to give more details.Meditation practice might be beneficial for the quality of life of haematologically-diseased patients, with higher scores for participants in the mediation arms compared to the participants in the usual care control group (low quality of evidence). Levels of depression decreased for those practising meditation in both the spiritually-framed meditation group and the secularly-focused meditation group in comparison to the usual care control group, whose levels of depression remained constant (low quality of evidence). The influence of meditation practice on overall survival, fatigue, anxiety, quality of sleep and adverse events remained unclear, as these outcomes were not evaluated in the included trial. To estimate the effects of meditation practice for patients suffering from haematological malignancies, more high quality randomised controlled trials are needed. At present there is not enough information available on the effects of meditation in haematologically-diseased patients to draw any conclusion.

Investigation of ciliary propulsion of Tetrahymena Pyriformis in viscous solution

NASA Astrophysics Data System (ADS)

Jung, Ilyong; Lyubich, Eva; Valles, James

2014-03-01

Recent experiments by our group showed that the ciliated protist Paramecium Caudatumswims with a constant propulsive force in solutions with viscosities 1 < η/ ηw<7 where ηw is the viscosity of water. Measurements of the geometry of its helical swimming trajectory combined with high speed video of the ciliary motion provided insight into this behavior. Using a phenomenological model we found that the body cilia beating frequency decreases while the beating angle remains roughly constant to produce the constant propulsive force dependence on viscosity. In this talk, we present studies of another ciliated protozoa, Tetrahymena Pyriformis to determine whether the behavior of Paramecium is general. Preliminary results indicate that Tetrahymena Pyriformis also swims with a nearly constant propulsive force with increasing viscosity. Investigations similar to those performed on Paramecium are underway and the latest results will be presented. This work was supported by NSF PHY0750360 and at the NHMFL by NSF DMR-0084173

Gas Exchange of Algae

PubMed Central

Ammann, Elizabeth C. B.; Lynch, Victoria H.

1965-01-01

Continuously growing cultures of Chlorella pyrenoidosa Starr 252, operating at constant density and under constant environmental conditions, produced uniform photosynthetic quotient (PQ = CO2/O2) and O2 values during 6 months of observations. The PQ for the entire study was 0.90 ± 0.024. The PQ remained constant over a threefold light-intensity change and a threefold change in O2 production (0.90 ± 0.019). At low light intensities, when the rate of respiration approached the rate of photosynthesis, the PQ became extremely variable. Six lamps of widely different spectral-energy distribution produced no significant change in the PQ (0.90 ± 0.025). Oxygen production was directly related to the number of quanta available, irrespective of spectral-energy distribution. Such dependability in producing uniform PQ and O2 values warrants a consideration of algae to maintain a constant gas environment for submarine or spaceship use. Images Fig. 1 PMID:14339260

Emotional states as mediators between tinnitus loudness and tinnitus distress in daily life: Results from the “TrackYourTinnitus” application

PubMed Central

Probst, Thomas; Pryss, Rüdiger; Langguth, Berthold; Schlee, Winfried

2016-01-01

The psychological process how tinnitus loudness leads to tinnitus distress remains unclear. This cross-sectional study investigated the mediating role of the emotional state “stress level” and of the two components of the emotional state “arousal” and “valence” with N = 658 users of the “TrackYourTinnitus” smartphone application. Stress mediated the relationship between tinnitus loudness and tinnitus distress in a simple mediation model and even in a multiple mediation model when arousal and valence were held constant. Arousal mediated the loudness-distress relationship when holding valence constant, but not anymore when controlling for valence as well as for stress. Valence functioned as a mediator when controlling for arousal and even when holding arousal and stress constant. The direct effect of tinnitus loudness on tinnitus distress remained significant in all models. This study demonstrates that emotional states affect the process how tinnitus loudness leads to tinnitus distress. We thereby could show that the mediating influence of emotional valence is at least equally strong as the influence of stress. Implications of the findings for future research, assessment, and clinical management of tinnitus are discussed. PMID:26853815

The influence of different error estimates in the detection of postoperative cognitive dysfunction using reliable change indices with correction for practice effects.

PubMed

Lewis, Matthew S; Maruff, Paul; Silbert, Brendan S; Evered, Lis A; Scott, David A

2007-02-01

The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of postoperative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week postoperatively using error and reliability data from a comparable healthy nonsurgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within-subject standard deviation (WSD), expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI.

[Malignant melanoma of the skin: does screening for cancer influence the incidence and mortality?].

PubMed

Schubert, A

2012-03-01

The increase in incidence of malignant melanoma, early diagnosis activities increasingly reaching ever larger population groups and mortality remaining at a constant level in trend comprise the background of the study. We aimed at answering the question whether the early diagnosis can have an influence on the increase in incidence and how one can one judge the effect on the reduction of the mortality. The study is based on data from official tumour registries of the regions Saarland, Schleswig-Holstein, the administrative district Münster, the former GDR and the New Dfederal states (Berlin, Brandenburg, Mecklenburg-Vorpommern, Sachsen, Sachsen-Anhalt, Thüringen), as well as that of Queensland (Australia). Parallel to the increasing incidence, there is also an increase in the number of melanomas detected at early stages. Hence, it is obvious to assume that this increase in incidence is due to a large extent to screening programmes. In a non-determinable number of cases, overdiagnostics could have contributed to the increase in incidence. In the period of observation mortality remained constant in the regions described in this study. It can be assumed the mortality risk is influenced by tumours with a high degree of malignancy whose share in the number of melanomas remains roughly constant. The early diagnosis of cancer, the inclusion of increasingly larger groups of the populations in the regions described, and constant mortality rates for men and women during the period of observation all relate the use of early diagnosis. If the efficiency of population screening is measured against the outcome reduction of the mortality rate, it appears to be sufficient to continue cancer early detection according to SGB V § 25. A preventive check-up is indicated for risk groups, e. g., those with a positive familiar history or if potentially malignant skin alterations have been diagnosed. © Georg Thieme Verlag KG Stuttgart · New York.

Analysis on Characteristics of a C-Shaped Constant-Force Spring with a Guide

NASA Astrophysics Data System (ADS)

Ohtsuki, Atsumi; Ohshima, Shigemichi; Itoh, Daisuke

A C-shaped constant-force spring is made of pre-stressed material in various sizes that offer the advantage of a constant tensile load, suitable for a variety of applications (for example, extension spring, motor-brush holder, power feed, retracting and restoring mechanism). Essentially, this spring consists of a coil of flat spring material and when unstressed it takes the form of a tightly wound spiral. This spiral is placed on a drum. When a tensile load is applied, the spiral uncoils. The load is practically independent of the amount of deformation. In this report, the extension mechanism of constant-force spring and the state of deformation are analyzed by using a large deformation theory. Moreover, experiments are carried out to confirm the applicability of the proposed theory. The experimental results agree well with the theoretical estimations.

An engineering method for estimating notch-size effect in fatigue tests on steel

NASA Technical Reports Server (NTRS)

Kuhn, Paul; Hardrath, Herbert F

1952-01-01

Neuber's proposed method of calculating a practical factor of stress concentration for parts containing notches of arbitrary size depends on the knowledge of a "new material constant" which can be established only indirectly. In this paper, the new constant has been evaluated for a large variety of steels from fatigue tests reported in the literature, attention being confined to stresses near the endurance limit. Reasonably satisfactory results were obtained with the assumption that the constant depends only on the tensile strength of the steel. Even in cases where the notches were cracks of which only the depth was known, reasonably satisfactory agreement was found between calculated and experimental factors. It is also shown that the material constant can be used in an empirical formula to estimate the size effect on unnotched specimens tested in bending fatigue.

The constant current loop - A new paradigm for resistance signal conditioning

NASA Astrophysics Data System (ADS)

Anderson, Karl F.

A practical single constant current loop circuit for the signal conditioning of variable-resistance transducers has been synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature device are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. An adaptation of the current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations.

Practical applications of current loop signal conditioning

NASA Astrophysics Data System (ADS)

Anderson, Karl F.

1994-10-01

This paper describes a variety of practical application circuits based on the current loop signal conditioning paradigm. Equations defining the circuit response are also provided. The constant current loop is a fundamental signal conditioning circuit concept that can be implemented in a variety of configurations for resistance-based transducers, such as strain gages and resistance temperature devices. The circuit features signal conditioning outputs which are unaffected by extremely large variations in lead wire resistance, direct current frequency response, and inherent linearity with respect to resistance change. Sensitivity of this circuit is double that of a Wheatstone bridge circuit. Electrical output is zero for resistance change equals zero. The same excitation and output sense wires can serve multiple transducers. More application arrangements are possible with constant current loop signal conditioning than with the Wheatstone bridge.

The constant current loop - A new paradigm for resistance signal conditioning

NASA Technical Reports Server (NTRS)

Anderson, Karl F.

1993-01-01

A practical single constant current loop circuit for the signal conditioning of variable-resistance transducers has been synthesized, analyzed, and demonstrated. The strain gage and the resistance temperature device are examples of variable-resistance sensors. Lead wires connect variable-resistance sensors to remotely located signal-conditioning hardware. The presence of lead wires in the conventional Wheatstone bridge signal-conditioning circuit introduces undesired effects that reduce the quality of the data from the remote sensors. A practical approach is presented for suppressing essentially all lead wire resistance effects while indicating only the change in resistance value. An adaptation of the current loop circuit is presented that simultaneously provides an output signal voltage directly proportional to transducer resistance change and provides temperature information that is unaffected by transducer and lead wire resistance variations.

Current loop signal conditioning: Practical applications

NASA Technical Reports Server (NTRS)

Anderson, Karl F.

1995-01-01

This paper describes a variety of practical application circuits based on the current loop signal conditioning paradigm. Equations defining the circuit response are also provided. The constant current loop is a fundamental signal conditioning circuit concept that can be implemented in a variety of configurations for resistance-based transducers, such as strain gages and resistance temperature detectors. The circuit features signal conditioning outputs which are unaffected by extremely large variations in lead wire resistance, direct current frequency response, and inherent linearity with respect to resistance change. Sensitivity of this circuit is double that of a Wheatstone bridge circuit. Electrical output is zero for resistance change equals zero. The same excitation and output sense wires can serve multiple transducers. More application arrangements are possible with constant current loop signal conditioning than with the Wheatstone bridge.

The Hubble Constant.

PubMed

Jackson, Neal

2015-01-01

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H 0 values of around 72-74 km s -1 Mpc -1 , with typical errors of 2-3 km s -1 Mpc -1 . This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68 km s -1 Mpc -1 and typical errors of 1-2 km s -1 Mpc -1 . The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.

Behavior of some singly ionized, heavy-ion impurities during compression in a theta-pinch plasma

NASA Technical Reports Server (NTRS)

Jalufka, N. W.

1975-01-01

The introduction of a small percentage of an impurity gas containing a desired element into a theta-pinch plasma is a standard procedure used to investigate the spectra and atomic processes of the element. This procedure assumes that the mixing ratio of impurity-to-fill gases remains constant during the collapse and heating phase. Spectroscopic investigations of the constant-mixing-ratio assumption for a 2% neon and argon impurity verifies the assumption only for the neon impurity. However, for the 2% argon impurity, only 20 to 25% of the argon is in the high-temperature compressed plasma. It is concluded that the constant-mixing-ratio assumption is not applicable to the argon impurity.

Spherical type integrable classical systems in a magnetic field

NASA Astrophysics Data System (ADS)

Marchesiello, A.; Šnobl, L.; Winternitz, P.

2018-04-01

We show that four classes of second order spherical type integrable classical systems in a magnetic field exist in the Euclidean space {E}3 , and construct the Hamiltonian and two second order integrals of motion in involution for each of them. For one of the classes the Hamiltonian depends on four arbitrary functions of one variable. This class contains the magnetic monopole as a special case. Two further classes have Hamiltonians depending on one arbitrary function of one variable and four or six constants, respectively. The magnetic field in these cases is radial. The remaining system corresponds to a constant magnetic field and the Hamiltonian depends on two constants. Questions of superintegrability—i.e. the existence of further integrals—are discussed.

Ideologies of Civic Participation in Central Asia: Liberal Arts in the Post-Soviet Democratic Ethos

ERIC Educational Resources Information Center

Baker, Norma Jo; Thompson, Chad D.

2010-01-01

Higher educational practices in post-Soviet Central Asia remain predicated on an authoritarian conception of expertise rooted in an objective and universal science. While the substance of such education has changed since the Soviet era, the form of education remains rooted in Soviet-era discursive ideological practices, practices that encourage…

Global warming: China’s contribution to climate change

NASA Astrophysics Data System (ADS)

Spracklen, Dominick V.

2016-03-01

Carbon dioxide emissions from fossil-fuel use in China have grown dramatically in the past few decades, yet it emerges that the country's relative contribution to global climate change has remained surprisingly constant. See Letter p.357

The School Office: An Overview.

ERIC Educational Resources Information Center

Hudson, Randy

2000-01-01

Presents an overview of the fundamental principles of school office design that remain constant despite changes in building technologies, and technological and spatial flexibility. Principles discussed include the school office and traffic patterns, security, and visitor reception requirements. (GR)

Energy analysis and agriculture: an application to US Corn Production

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

Smil, V.; Nachman, P.; Long, T.V. II

1983-01-01

Changes in farming technology have increased the amount and cost of energy used in crop production, raising the question of whether energy efficiency in agriculture has remained constant, decreased, or increased. Despite some studies to the contrary, the authors assert that all essential energy used, both directly and indirectly, in US corn farming has remained constant in relation to crop production during the past two decades. Using a detailed process of energy analysis that takes into account various management and technological changes, they trace and quantify the energy cost of corn production from 1945-1947 and forecast its changes through 1984.more » They conclude that the energy efficiency of corn farming has not declined, and find that future technological and process improvements, led by conservation measures, will likely increase its energy efficiency in the 1980s. 39 references, 33 figures, 88 tables.« less

Dimmable sunlight-like organic light emitting diodes with ultra-high color rendering index

NASA Astrophysics Data System (ADS)

Wu, Jin-Han; Chi, Chien-An; Chiang, Chang-Lin; Chen, Guan-Yu; Lin, Yi-Ping; Chen, Cheng-Chang; Ho, Shu-Yi; Chen, Shih-Pu; Li, Jung-Yu

2016-05-01

We propose novel dimmable sunlight-like white organic light-emitting diodes that were fabricated using three luminophores to form an emitting spectrum similar to black body radiation at 2250 K with ultra-high color rendering index (CRI) value of 91, which nearly remained the constant at various luminance values ranging from 100 to more than 2500 cd/m2 at Commission Internationale de l'Eclairage chromaticity coordinates of (0.51, 0.41). Introducing charge modification layers suppressed the energy transfer between the emitting material layers and increased the probability of carrier recombination. Moreover, we reveal that covering long-wavelength ranges played a vital role in achieving high CRI values; the CRI values of a spectrum artificially shifted toward a long-wavelength direction (from 610 to 620 nm) remained constant, whereas those of a spectrum shifted toward a short-wavelength direction (from 610 to 600 nm) dropped to 79.

Effects of S and N doping on the structural, magnetic and electronic properties of rutile CrO2

NASA Astrophysics Data System (ADS)

Xie, You; Zhou, An-Ning; Sun, Kai-Gang; Zhang, Ya-Ting; Huo, Yi-Ping; Wang, Su-Fang; Zhang, Jian-Min

2016-05-01

Magnetic and electronic properties of S- and N-doped CrO2 are studied by using the first-principle projector augmented wave potential within the generalized gradient approximation. The optimized lattice constants for CrO2 agree well with the previous work. With increasing S doping (N doping), the lattice constants of CrO2-xSx (CrO2-xNx) (x=0.5, 1 and 1.5) all increase (decrease), While these compounds remain the tetragonal structure. CrO1.5S0.5, CrO1.5N0.5 and CrON compounds remain the half-metallicity, while the band gap is determined by different factors. It is also found that the change of the total magnetic moment with equivalent atom S doping in CrO2 compound is small except for x=1.

Trying to Get Ahead of the Curve: Raising and Understanding Current Themes in New Literacies Practices

ERIC Educational Resources Information Center

Wilber, Dana

2012-01-01

This article addresses the following questions: What impact does using the theoretical framework of new literacies have on understanding language, literacy, and learning practices today as technologies are constantly being developed and used? What is the state of research in this area? What are some new directions the field might take in order to…

Marketing Is Not a Luxury - Marketing Is a Necessity.

PubMed

Price, Sean

2017-10-01

Physicians who work in small practices constantly face a basic marketing question: What's the best way to sell myself and my business to the community? Because few physicians studied business principles, many won't know the answer. That's why the Texas Medical Association is publishing a book titled Marketing Smart: A Guide for Medical Practices.

Communication, Respect, and Leadership: Interprofessional Collaboration in Hospitals of Rural Ontario.

PubMed

Morris, Diane; Matthews, June

2014-12-01

Health care professionals are expected to work collaboratively across diverse settings. In rural hospitals, these professionals face different challenges from their urban colleagues; however, little is known about interprofessional practice in these settings. Eleven health care professionals from 2 rural interprofessional teams were interviewed about collaborative practice. The data were analyzed using a constant comparative method. Common themes included communication, respect, leadership, benefits of interprofessional teams, and the assets and challenges of working in small or rural hospitals. Differences between the cases were apparent in how the members conceptualized their teams, models of which were then compared with an "Ideal Interprofessional Team". These results suggest that many experienced health care professionals function well in interprofessional teams; yet, they did not likely receive much education about interprofessional practice in their training. Providing interprofessional education to new practitioners may help them to establish this approach early in their careers and build on it with additional experience. Finally, these findings can be applied to address concerns that have arisen from other reports by exploring innovative ways to attract health professionals to communities in rural, remote, and northern areas, as there is a constant need for dietitians and other health care professionals in these practice settings.

A novel constant-force scanning probe incorporating mechanical-magnetic coupled structures.

PubMed

Wang, Hongxi; Zhao, Jian; Gao, Renjing; Yang, Yintang

2011-07-01

A one-dimensional scanning probe with constant measuring force is designed and fabricated by utilizing the negative stiffness of the magnetic coupled structure, which mainly consists of the magnetic structure, the parallel guidance mechanism, and the pre-stressed spring. Based on the theory of material mechanics and the equivalent surface current model for computing the magnetic force, the analytical model of the scanning probe subjected to multi-forces is established, and the nonlinear relationship between the measuring force and the probe displacement is obtained. The practicability of introducing magnetic coupled structure in the constant-force probe is validated by the consistency of the results in numerical simulation and experiments.

Analysis of water microdroplet condensation on silicon surfaces

NASA Astrophysics Data System (ADS)

Honda, Takuya; Fujimoto, Kenya; Yoshimoto, Yuta; Mogi, Katsuo; Kinefuchi, Ikuya; Sugii, Yasuhiko; Takagi, Shu; Univ. of Tokyo Team; Tokyo Inst. of Tech. Team

2016-11-01

We observed the condensation process of water microdroplets on flat silicon (100) surfaces by means of the sequential visualization of the droplets using an environmental scanning electron microscope. As previously reported for nanostructured surfaces, the condensation process of water microdroplets on the flat silicon surfaces also exhibits two modes: the constant base (CB) area mode and the constant contact angle (CCA) mode. In the CB mode, the contact angle increases with time while the base diameter is constant. Subsequently, in the CCA mode, the base diameter increases with time while the contact angle remains constant. The dropwise condensation model regulated by subcooling temperature does not reproduce the experimental results. Because the subcooling temperature is not constant in the case of a slow condensation rate, this model is not applicable to the condensation of the long time scale ( several tens of minutes). The contact angle of water microdroplets ( several μm) tended to be smaller than the macro contact angle. Two hypotheses are proposed as the cause of small contact angles: electrowetting and the coalescence of sub- μm water droplets.

Relative sensitivities of DCE-MRI pharmacokinetic parameters to arterial input function (AIF) scaling

NASA Astrophysics Data System (ADS)

Li, Xin; Cai, Yu; Moloney, Brendan; Chen, Yiyi; Huang, Wei; Woods, Mark; Coakley, Fergus V.; Rooney, William D.; Garzotto, Mark G.; Springer, Charles S.

2016-08-01

Dynamic-Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) has been used widely for clinical applications. Pharmacokinetic modeling of DCE-MRI data that extracts quantitative contrast reagent/tissue-specific model parameters is the most investigated method. One of the primary challenges in pharmacokinetic analysis of DCE-MRI data is accurate and reliable measurement of the arterial input function (AIF), which is the driving force behind all pharmacokinetics. Because of effects such as inflow and partial volume averaging, AIF measured from individual arteries sometimes require amplitude scaling for better representation of the blood contrast reagent (CR) concentration time-courses. Empirical approaches like blinded AIF estimation or reference tissue AIF derivation can be useful and practical, especially when there is no clearly visible blood vessel within the imaging field-of-view (FOV). Similarly, these approaches generally also require magnitude scaling of the derived AIF time-courses. Since the AIF varies among individuals even with the same CR injection protocol and the perfect scaling factor for reconstructing the ground truth AIF often remains unknown, variations in estimated pharmacokinetic parameters due to varying AIF scaling factors are of special interest. In this work, using simulated and real prostate cancer DCE-MRI data, we examined parameter variations associated with AIF scaling. Our results show that, for both the fast-exchange-limit (FXL) Tofts model and the water exchange sensitized fast-exchange-regime (FXR) model, the commonly fitted CR transfer constant (Ktrans) and the extravascular, extracellular volume fraction (ve) scale nearly proportionally with the AIF, whereas the FXR-specific unidirectional cellular water efflux rate constant, kio, and the CR intravasation rate constant, kep, are both AIF scaling insensitive. This indicates that, for DCE-MRI of prostate cancer and possibly other cancers, kio and kep may be more suitable imaging biomarkers for cross-platform, multicenter applications. Data from our limited study cohort show that kio correlates with Gleason scores, suggesting that it may be a useful biomarker for prostate cancer disease progression monitoring.

Hematology oncology practice in the Asia-Pacific APHCON survey results from the 6th international hematologic malignancies conference: bridging the gap 2015, Beijing, China.

PubMed

Huang, Xiao Jun; Liu, Kaiyan; Ritchie, David; Andersson, Borje; Lu, Jin; Hou, Jian; Burguera, Adolfo de la Fuente; Wang, JianXiang; Yeoh, Allen; Yan, Chenhua; Zhou, Daobin; Tan, Daryl; Kim, Dong Wook; Wu, Depei; Shpall, Elizabeth; Kornblau, Stephen; Neelapu, Sattava; Hongeng, Suradej; Li, Jianyong; Hu, Jiong; Zhang, Lian Sheng; Wang, Michael; Malhotra, Pankaj; Jiang, Qian; Qin, Yazhen; Wong, Raymond; Champlin, Richard; Hagemeister, Frederick; Westin, Jason; Iyer, Swaminathan; Mathews, Vikram; Wang, Yu; Hu, Yu; Xiao, Zhijian; Shao, Zonghong; Orlowski, Robert Z; Chim, Chor Sang; Mulligan, Stephen; Sanz, Miguel; Ozawa, Keiya; Parmar, Simrit; Issaragrisil, Surapol

2017-06-20

This report serves as a snapshot of the state-of-knowledge in the Asia Pacific (APAC) Hematology Oncology community, and establishes a baseline for longitudinal investigations to follow changes in best practices over time. The objective of this study was to understand the approach to hematologic diseases, common standards of care and best practices, issues that remain controversial or debated, and educational or resource gaps that warrant attention. We used mobile application to disseminate and distribute questionnaires to delegates during the 6th international hematologic malignancies conference hosted by the APAC Hematology Consortium at Beijing, China. User responses were collected in an anonymous fashion. We report survey results in two ways: the overall responses, and responses as stratified between Chinese physicians and "Other" represented nationalities. Overall geographical concordance in survey responses was positive and strong. Perhaps more interesting than instances of absolute agreement, these data provide a unique opportunity to identify topics in which physician knowledge or opinions diverge. We assigned questions from all modules to broad categories of: patient information; diagnosis; treatment preference; transplantation; and general knowledge/opinion. On average, we observed a geographic difference of 15% for any particular answer choice, and this was fairly constant across survey modules. These results reveal utility and need for widespread and ongoing initiatives to assess knowledge and provide evidence-based education in real time. The data will be made more valuable by longitudinal participation, such that we can monitor changes in the state of the art over time.

Translating caring theory across the continuum from inpatient to ambulatory care.

PubMed

Tonges, Mary; McCann, Meghan; Strickler, Jeff

2014-06-01

While theory-based practice is a Magnet® characteristic, translating theories to practice remains challenging. As a result, theory-guided practice remains an ideal rather than a realized goal in many organizations. This article provides an overview of a research-derived caring theory, a translational model for theory-driven practice, implementation of a delivery model designed to translate theory across the acute and ambulatory care continuum, and resulting outcomes in oncology clinics and the emergency department.

A novel remaining tendon preserving repair technique leads to improved outcomes in special rotator cuff tear patterns.

PubMed

Jeon, Yoon Sang; Kim, Rag Gyu; Shin, Sang-Jin

2018-05-16

The purpose of this study was to identify the tear pattern that could be anatomically repaired by preserving the remaining tendon on footprint and evaluate clinical outcomes of patients who underwent remaining tendon preserving cuff repair. Of 523 patients with full-thickness rotator cuff tears who underwent arthroscopic repair, 41 (7.8%) patients had repairable rotator cuff tear while preserving the remaining tendon. Among them, 31 patients were followed-up for more than 2 years, including 26 patients with posterior L-shaped tear and 5 patients with transtendinous tear patterns. Clinical outcomes were evaluated using ASES and Constant score, SANE score for patient satisfaction, and VAS for pain. MRI was taken for tendon integrity 6 months postoperatively. Of the 31 patients, 11 (35.5%) had previous injury history before rotator cuff tear, including 7 (26.9%) of the 26 patients with posterior L-shaped tear and 4 (80%) of the 5 patients with transtendinous tear. The average size of preoperative cuff tear was 17.8 ± 6.8 mm in anterior-to-posterior direction and 15.2 ± 5.1 mm in medial-to-lateral direction. ASES and Constant score, SANE score, and VAS for pain were significantly (p < 0.001) improved after remaining tendon preserving rotator cuff repair. Rotator cuff tendons of 22(84.6%) patients with posterior L-shaped tear and 4(80%) patients with transtendinous tear patterns were healed. Patients who underwent rotator cuff repair with preservation of the remaining tendon on the footprint obtained satisfactory functional outcomes. Rotator cuff tears in patients who had posterior L-shaped tear extending between supraspinatus and infraspinatus tendons or transtendinous tear pattern with substantial remaining tendon could be repaired using remaining tendon preserving repair technique. Anatomic reduction of torn cuff tendon without undue tension could be achieved using the remaining tendon preserving repair technique.

From Community to Meta-Community Mental Health Care.

PubMed

Bouras, Nick; Ikkos, George; Craig, Thomas

2018-04-20

Since the 1960s, we have witnessed the development and growth of community mental health care that continues to dominate mental health policy and practice. Several high-income countries have implemented community mental health care programmes but for many others, including mostly low- and middle-income countries, it remains an aspiration. Although community mental health care has been positive for many service users, it has also had severe shortcomings. Expectations that it would lead to fuller social integration have not been fulfilled and many service users remain secluded in sheltered or custodial environments with limited social contacts and no prospect of work. Others receive little or no service at all. In today’s complex landscape of increasingly specialised services for people with mental health problems, the number of possible interfaces between services is increasing. Together with existing uneven financing systems and a context of constant change, these interfaces are challenging us to develop effective care pathways adjusted to the needs of service users and their carers. This discussion paper reviews the developments in community mental health care over the recent years and puts forward the concept of “Meta-Community Mental Health Care”. “Meta-Community Mental Health Care” embraces pluralism in understanding and treating psychiatric disorders, acknowledges the complexities of community provision, and reflects the realities and needs of the current era of care.

Kink modes and surface currents associated with vertical displacement events

NASA Astrophysics Data System (ADS)

Manickam, Janardhan; Boozer, Allen; Gerhardt, Stefan

2012-08-01

The fast termination phase of a vertical displacement event (VDE) in a tokamak is modeled as a sequence of shrinking equilibria, where the core current profile remains constant so that the safety-factor at the axis, qaxis, remains fixed and the qedge systematically decreases. At some point, the n = 1 kink mode is destabilized. Kink modes distort the magnetic field lines outside the plasma, and surface currents are required to nullify the normal component of the B-field at the plasma boundary and maintain equilibrium at finite pressure. If the plasma touches a conductor, the current can be transferred to the conductor, and may be measurable by the halo current monitors. This report describes a practical method to model the plasma as it evolves during a VDE, and determine the surface currents, needed to maintain equilibrium. The main results are that the onset conditions for the disruption are that the growth-rate of the n = 1 kink exceeds half the Alfven time and the associated surface current needed to maintain equilibrium exceeds one half of the core plasma current. This occurs when qedge drops below a low integer, usually 2. Application to NSTX provides favorable comparison with non-axisymmetric halo-current measurements. The model is also applied to ITER and shows that the 2/1 mode is projected to be the most likely cause of the final disruption.

From Community to Meta-Community Mental Health Care

PubMed Central

Bouras, Nick; Ikkos, George; Craig, Thomas

2018-01-01

Since the 1960s, we have witnessed the development and growth of community mental health care that continues to dominate mental health policy and practice. Several high-income countries have implemented community mental health care programmes but for many others, including mostly low- and middle-income countries, it remains an aspiration. Although community mental health care has been positive for many service users, it has also had severe shortcomings. Expectations that it would lead to fuller social integration have not been fulfilled and many service users remain secluded in sheltered or custodial environments with limited social contacts and no prospect of work. Others receive little or no service at all. In today’s complex landscape of increasingly specialised services for people with mental health problems, the number of possible interfaces between services is increasing. Together with existing uneven financing systems and a context of constant change, these interfaces are challenging us to develop effective care pathways adjusted to the needs of service users and their carers. This discussion paper reviews the developments in community mental health care over the recent years and puts forward the concept of “Meta-Community Mental Health Care”. “Meta-Community Mental Health Care” embraces pluralism in understanding and treating psychiatric disorders, acknowledges the complexities of community provision, and reflects the realities and needs of the current era of care. PMID:29677100

A review on effectiveness of best management practices in improving hydrology and water quality: Needs and opportunities.

PubMed

Liu, Yaoze; Engel, Bernard A; Flanagan, Dennis C; Gitau, Margaret W; McMillan, Sara K; Chaubey, Indrajeet

2017-12-01

Best management practices (BMPs) have been widely used to address hydrology and water quality issues in both agricultural and urban areas. Increasing numbers of BMPs have been studied in research projects and implemented in watershed management projects, but a gap remains in quantifying their effectiveness through time. In this paper, we review the current knowledge about BMP efficiencies, which indicates that most empirical studies have focused on short-term efficiencies, while few have explored long-term efficiencies. Most simulation efforts that consider BMPs assume constant performance irrespective of ages of the practices, generally based on anticipated maintenance activities or the expected performance over the life of the BMP(s). However, efficiencies of BMPs likely change over time irrespective of maintenance due to factors such as degradation of structures and accumulation of pollutants. Generally, the impacts of BMPs implemented in water quality protection programs at watershed levels have not been as rapid or large as expected, possibly due to overly high expectations for practice long-term efficiency, with BMPs even being sources of pollutants under some conditions and during some time periods. The review of available datasets reveals that current data are limited regarding both short-term and long-term BMP efficiency. Based on this review, this paper provides suggestions regarding needs and opportunities. Existing practice efficiency data need to be compiled. New data on BMP efficiencies that consider important factors, such as maintenance activities, also need to be collected. Then, the existing and new data need to be analyzed. Further research is needed to create a framework, as well as modeling approaches built on the framework, to simulate changes in BMP efficiencies with time. The research community needs to work together in addressing these needs and opportunities, which will assist decision makers in formulating better decisions regarding BMP implementation in watershed management projects. Copyright © 2017 Elsevier B.V. All rights reserved.

Teaching the concept of dispersion by diffraction of light to elementary school students

NASA Astrophysics Data System (ADS)

Resnick, J.; Monroy-Ramírez, F. A.

2017-08-01

This paper discusses the development and implementation of a practice based on Active Learning Methodology (ALM) with the aim of encouraging students from an early age to be interested in the world of science. The practical proposal is registered in the area of physics, especially in the field of wave optics, since it turns out to be very attractive to all ages especially for children. This didactic sequence was developed with students from elementary school. The experimental sequence developed is composed by several experimental activities allowing to observe and describe the phenomenon of diffraction scattering, from the entering of light through a piece of compact disc (CD) which acts as a diffraction grating. The distance between the diffraction grating and the screen on which the maximum intensity markers are projected remains constant throughout the practice. Children light up the CD with a red pointer, mark on the screen the position of the different maximum intensity markers, then repeat with the green pointer and finally with blue; from observation and the answer of guiding questions proposed by the teacher, they begin to draw conclusions to diffraction for each wavelength. In this way, the child observes that the maximum intensity markers (diffraction orders) associated with each color are located in different positions. Later, children are enquired about the result of the process when it is repeated with white light. Immediately afterwards, the experiment is tried with white light to check it. Finally, comparing the results observed with pointers in different colors with the result out of the practice with white light, a relevant discussion starts, bringing students to the concept of diffraction scattering. An important aspect is that the materials used in this experiment represents an important advantage in their application, since they are easily accessible (except for laser pointers in colors that are not very common in some places), so it is a practice affordable to any socioeconomic population besides being very striking to students.

Inviscid to turbulent transition of trailing vortices

NASA Technical Reports Server (NTRS)

Iversen, J. D.

1974-01-01

The characteristics of the plateau region in the vortex system which trails from a lifting wing are discussed. The decay of the vortex due to viscous or turbulent shear is very slow in the plateau so that the maximum tangential speed in the vortices remains nearly constant for some distance downstream of roll-up and then begins to decrease, becoming inversely proportional to the square root of the distance downstream. Mathematical models are developed to analyze the structure of the plateau area. Solutions are obtained for both constant and variable eddy viscosity models.

User Instructions for the Final Version of the EPIC Research Code

DTIC Science & Technology

1996-04-01

by which library fracture strain constants (D1, D2, EFMIN- defined later) are multiplied. DFRAC = 1.0 will provide the exact library constants. EFAIL ...If EFAIL > 999, the check for total failure will be omitted. Deription Card for Solids Input Data (415, aX F5.0, A50) - This card (plus five additional...hydrostatic pressure capability remains. Can be used only with DAM 1. T142M 57 0 0 0 0 0 0 0 0 0 EFAIL - Equivalent plastic strain, or volumetric strain

Quintessential inflation from a variable cosmological constant in a 5D vacuum

NASA Astrophysics Data System (ADS)

Membiela, Agustin; Bellini, Mauricio

2006-10-01

We explore an effective 4D cosmological model for the universe where the variable cosmological constant governs its evolution and the pressure remains negative along all the expansion. This model is introduced from a 5D vacuum state where the (space-like) extra coordinate is considered as noncompact. The expansion is produced by the inflaton field, which is considered as nonminimally coupled to gravity. We conclude from experimental data that the coupling of the inflaton with gravity should be weak, but variable in different epochs of the evolution of the universe.

Stability of colloidal gold and determination of the Hamaker constant

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

Demirci, S.; Enuestuen, B.V.; Turkevich, J.

1978-12-14

Previous computation of stability factors of colloidal gold from coagulation data was found to be in systematic error due to an underestimation of the particle concentration by electron microscopy. A new experimental technique was developed for determination of this concentration. Stability factors were recalculated from the previous data using the correct concentration. While most of the previously reported conclusions remain unchanged, the absolute rate of fast coagulation is found to agree with that predicted by the theory. A value of the Hamaker constant was determined from the corrected data.

Exact Green's function method of solar force-free magnetic-field computations with constant alpha. I - Theory and basic test cases

NASA Technical Reports Server (NTRS)

Chiu, Y. T.; Hilton, H. H.

1977-01-01

Exact closed-form solutions to the solar force-free magnetic-field boundary-value problem are obtained for constant alpha in Cartesian geometry by a Green's function approach. The uniqueness of the physical problem is discussed. Application of the exact results to practical solar magnetic-field calculations is free of series truncation errors and is at least as economical as the approximate methods currently in use. Results of some test cases are presented.

"Phronesis" on tour: cultural adaptability of Aristotelian ethical notions.

PubMed

Polansky, R

2000-12-01

How might bioethics take account of cultural diversity? Can practical wisdom of an Aristotelian sort be applied across cultures? After showing that practical wisdom involves both intellectual cleverness and moral virtue, it is argued that both these components have universality. Hence practical wisdom must be universal as well. Hellenic ethical thought neither depended on outdated theoretical notions nor limited itself to the Greek world, but was in fact developed with constant awareness of cultural differences, so it arguably works as well in other times and places when formulated. Even the eudaemonistic setting for practical wisdom is unproblematic.

Long-term weight loss observed with olanzapine orally disintegrating tablets in overweight patients with chronic schizophrenia. A 1 year open-label, prospective trial.

PubMed

Chawla, Bharat; Luxton-Andrew, Heather

2008-04-01

To investigate the long-term weight loss outcomes during usual clinical practice after switching from olanzapine standard oral tablet (SOT) to olanzapine orally disintegrating tablets (ODT). In this open-label prospective study, 26 patients with schizophrenia who were clinically stable on olanzapine SOT treatment were switched to olanzapine ODT. All other aspects of treatment remained constant. Weight was recorded at 3, 6, and 12 months. Patients incurred an average weight loss of 2.7 +/- 0.7 kg (p = 0.001) after switching patients from olanzapine SOT to olanzapine ODT at 12 months. Peak weight loss was observed at 6 months; however, significant weight loss was achieved as early as 3 months. The majority (81.9%) of patients lost weight, while 18.1% had no weight change or weight gain. Body mass index (BMI) significantly decreased by 1.0 +/- 0.3 kg/m(2) (p = 0.001). Interestingly, patients treated with higher doses of olanzapine (> or = 20 mg) incurred a greater weight loss of their body weight (5.6%), compared to those treated with lower doses (< 20 mg), who lost 1.9% of their body weight (p = 0.04). This study demonstrated that, in usual clinical practice, switching patients from olanzapine SOT to olanzapine ODT treatment resulted in significant weight loss that was maintained over 12 months. 2008 John Wiley & Sons, Ltd.

A chronicle of surgical thinking and doing for exotropia: innovations and rediscoveries.

PubMed

Raab, Edward L

2017-06-01

To review the evolution of theories and practices concerning surgery for exotropia over the last approximately 200 years. Major ophthalmology texts and relevant references were reviewed to discover experience and thinking concerning the causes of comitant intermittent and constant exotropia and corrective surgical approaches. The concept that excessive divergence is the cause of comitant exotropia has given way to one recognizing that this disorder is a position of rest modified by convergence. Some operations discarded as unreliable or dangerous remain so today. Others continue to be well accepted, whether or not relating to advances in understanding of this condition. Several procedures practiced at former times have regained popularity. Concern for the characteristics of extraocular muscle structure and function has led to surgical thinking that goes beyond consideration only of direction and magnitude of deviation. Sophisticated devices now provide heretofore unavailable information consistent with this new approach. The history of progress in surgery for exotropia is mixed. Although some procedures now employed are new, others currently in favor had been well known and formerly utilized by ophthalmologists for many decades. These should be regarded as rediscoveries or revivals rather than as novel. This review also suggests a need to address how to better report retrospective studies. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Space Flight Resource Management Training for International Space Station Flight Controllers

NASA Technical Reports Server (NTRS)

O'Keefe, William S.

2011-01-01

Training includes both SFRM-dedicated lessons and SFRM training embedded into technical lessons. Goal is to reduce certification times by 50% and integrated simulations by 75-90%. SFRM is practiced, evaluated and debriefed in part task trainers and full-task simulation lessons. SFRM model and training are constantly being evaluated against student/management feedback, best practices from industry/ military, and latest research.

Nuclear-spin optical rotation in xenon

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

Savukov, Igor Mykhaylovich

We report that the nuclear-spin optical rotation (NSOR) effect, which has potential applications in correlated nuclear-spin-resonance optical spectroscopy, has previously been explored experimentally and theoretically in liquid Xe. Calculations of the Xe NSOR constant are very challenging because the result is sensitive to correlations, relativistic effects, and the choice of basis, with strong cancellation between contributions from lowest and remaining states. The relativistic configuration-interaction many-body-theory approach, presented here, is promising because this approach has been successful in predicting various properties of noble-gas atoms, such as energies, oscillator strengths (OSs), Verdet constants, and photoionization cross sections. However, correlations become stronger alongmore » the sequence of noble-gas atoms and the theoretical accuracy in Xe is not as high as, for example, in neon and argon. To improve the accuracy of the Xe Verdet and NSOR constants, which are calculated as explicit sums over the excited states, theoretical values for the several lowest levels are replaced with empirical values of energies, OSs, and hyperfine structure constants. We found that the Xe Verdet constant is in excellent agreement with accurate measurements. To take into account liquid effects, empirical data for energy shifts were also used to correct the NSOR constant. In conclusion, the resulting Xe NSOR constant is in a good agreement with experiment, although the liquid-state effect is treated quite approximately.« less

Nuclear-spin optical rotation in xenon

DOE PAGES

Savukov, Igor Mykhaylovich

2015-10-29

We report that the nuclear-spin optical rotation (NSOR) effect, which has potential applications in correlated nuclear-spin-resonance optical spectroscopy, has previously been explored experimentally and theoretically in liquid Xe. Calculations of the Xe NSOR constant are very challenging because the result is sensitive to correlations, relativistic effects, and the choice of basis, with strong cancellation between contributions from lowest and remaining states. The relativistic configuration-interaction many-body-theory approach, presented here, is promising because this approach has been successful in predicting various properties of noble-gas atoms, such as energies, oscillator strengths (OSs), Verdet constants, and photoionization cross sections. However, correlations become stronger alongmore » the sequence of noble-gas atoms and the theoretical accuracy in Xe is not as high as, for example, in neon and argon. To improve the accuracy of the Xe Verdet and NSOR constants, which are calculated as explicit sums over the excited states, theoretical values for the several lowest levels are replaced with empirical values of energies, OSs, and hyperfine structure constants. We found that the Xe Verdet constant is in excellent agreement with accurate measurements. To take into account liquid effects, empirical data for energy shifts were also used to correct the NSOR constant. In conclusion, the resulting Xe NSOR constant is in a good agreement with experiment, although the liquid-state effect is treated quite approximately.« less

Evolution of circadian rhythms in Drosophila melanogaster populations reared in constant light and dark regimes for over 330 generations.

PubMed

Shindey, Radhika; Varma, Vishwanath; Nikhil, K L; Sharma, Vijay Kumar

2017-01-01

Organisms are believed to have evolved circadian clocks as adaptations to deal with cyclic environmental changes, and therefore it has been hypothesized that evolution in constant environments would lead to regression of such clocks. However, previous studies have yielded mixed results, and evolution of circadian clocks under constant conditions has remained an unsettled topic of debate in circadian biology. In continuation of our previous studies, which reported persistence of circadian rhythms in Drosophila melanogaster populations evolving under constant light, here we intended to examine whether circadian clocks and the associated properties evolve differently under constant light and constant darkness. In this regard, we assayed activity-rest, adult emergence and oviposition rhythms of D. melanogaster populations which have been maintained for over 19 years (~330 generations) under three different light regimes - constant light (LL), light-dark cycles of 12:12 h (LD) and constant darkness (DD). We observed that while circadian rhythms in all the three behaviors persist in both LL and DD stocks with no differences in circadian period, they differed in certain aspects of the entrained rhythms when compared to controls reared in rhythmic environment (LD). Interestingly, we also observed that DD stocks have evolved significantly higher robustness or power of free-running activity-rest and adult emergence rhythms compared to LL stocks. Thus, our study, in addition to corroborating previous results of circadian clock evolution in constant light, also highlights that, contrary to the expected regression of circadian clocks, rearing in constant darkness leads to the evolution of more robust circadian clocks which may be attributed to an intrinsic adaptive advantage of circadian clocks and/or pleiotropic functions of clock genes in other traits.

Monte Carlo simulation on the effect of different approaches to thalassaemia on gene frequency.

PubMed

Habibzadeh, F; Yadollahie, M

2006-01-01

We used computer simulation to determine variation in gene, heterozygous and homozygous frequencies induced by 4 different approaches to thalassaemia. These were: supportive therapy only; treat homozygous patients with a hypothetical modality phenotypically only; abort all homozygous fetuses; and prevent marriage between gene carriers. Gene frequency becomes constant with the second or the fourth strategy, and falls over time with the first or the third strategy. Heterozygous frequency varies in parallel with gene frequency. Using the first strategy, homozygous frequency falls over time; with the second strategy it becomes constant; and with the third and fourth strategies it falls to zero after the first generation. No matter which strategy is used, the population gene frequency, in the worst case, will remain constant over time.

Determination of the cosmological rate of change of G and the tidal accelerations of earth and moon from ancient and modern astronomical data

NASA Technical Reports Server (NTRS)

Muller, P. M.

1976-01-01

The theory and numerical analysis of ancient astronomical observations (1374 to 1715) are combined with modern data in a simultaneous solution for: the tidal acceleration of the lunar longitude; the observed apparent acceleration of the earth's rotation; the true nontidal geophysical part of this acceleration; and the rate of change in the gravitational constant. Provided are three independent determinations of a rate of change of G consistent with the Hubble Constant and a near zero nontidal rotational acceleration of the earth. The tidal accelerations are shown to have remained constant during the historical period within uncertainties. Ancient and modern solar system data, and extragalactic observations provided a completely consistent astronomical and cosmological scheme.

Gap solitons in PT-symmetric optical lattices with higher-order diffraction.

PubMed

Ge, Lijuan; Shen, Ming; Ma, Chunlan; Zang, Taocheng; Dai, Lu

2014-12-01

The existence and stability of gap solitons are investigated in the semi-infinite gap of a parity-time (PT)-symmetric periodic potential (optical lattice) with a higher-order diffraction. The Bloch bands and band gaps of this PT-symmetric optical lattice depend crucially on the coupling constant of the fourth-order diffraction, whereas the phase transition point of this PT optical lattice remains unchangeable. The fourth-order diffraction plays a significant role in destabilizing the propagation of dipole solitons. Specifically, when the fourth-order diffraction coupling constant increases, the stable region of the dipole solitons shrinks as new regions of instability appear. However, fundamental solitons are found to be always linearly stable with arbitrary positive value of the coupling constant. We also investigate nonlinear evolution of the PT solitons under perturbation.

Constant or special observations of inpatients presenting a risk of aggression or violence: nurses' perceptions of the rules of engagement.

PubMed

Mackay, I; Paterson, B; Cassells, C

2005-08-01

In acute psychiatric settings the practice of 'observation' is commonly employed. Increased levels of observation, 'constant' or 'special' are used for those perceived as presenting a 'higher' risk. As an intervention it is used most frequently for those at risk of self-harm or suicide, the practice is also however, used for those thought to present a risk of violent behaviour. In this descriptive study the perceptions of 1st level registered mental nurses (RMNs) gave an account of observation for those perceived to be at risk of violence or aggression and insight into what was considered important and desirable in practice. Unstructured qualitative interviews were conducted with a purposive sample of six RMNs from a psychiatric intensive care unit. Three major categories, Procedure, Role, and Skills emerged which revealed a complex practice far removed from its literal description as merely 'watching'. Six subcategories emerged from the Role. (1) intervening; (2) maintaining the safety of the patient and others; (3) prevention de-escalation and the management of aggression and violence; (4) assessing; (5) communication; and (6) therapy. Skills in these and, experience were thought to IMPACT on the success of the practice. The description of this and the skills involved offer a definition of the 'rules of engagement' which give insight to the practice and the training needs of staff advocated for 'observation'. The acronym IMPACT may be useful in this.

Effect of the meniscus contact angle during early regimes of spontaneous imbibition in nanochannels.

PubMed

Karna, Nabin Kumar; Oyarzua, Elton; Walther, Jens H; Zambrano, Harvey A

2016-11-30

Nanoscale capillarity has been extensively investigated; nevertheless, many fundamental questions remain open. In spontaneous imbibition, the classical Lucas-Washburn equation predicts a singularity as the fluid enters the channel consisting of an anomalous infinite velocity of the capillary meniscus. Bosanquet's equation overcomes this problem by taking into account fluid inertia predicting an initial imbibition regime with constant velocity. Nevertheless, the initial constant velocity as predicted by Bosanquet's equation is much greater than those observed experimentally. In the present study, large scale atomistic simulations are conducted to investigate capillary imbibition of water in slit silica nanochannels with heights between 4 and 18 nm. We find that the meniscus contact angle remains constant during the inertial regime and its value depends on the height of the channel. We also find that the meniscus velocity computed at the channel entrance is related to the particular value of the meniscus contact angle. Moreover, during the subsequent visco-inertial regime, as the influence of viscosity increases, the meniscus contact angle is found to be time dependent for all the channels under study. Furthermore, we propose an expression for the time evolution of the dynamic contact angle in nanochannels which, when incorporated into Bosanquet's equation, satisfactorily explains the initial capillary rise.

Reference database of lung volumes and capacities in wistar rats from 2 to 24 months.

PubMed

Filho, Wilson Jacob; Fontinele, Renata Gabriel; de Souza, Romeu Rodrigues

2014-01-01

This study determines the effects of growing and aging on lung physiological volumes and capacities and the incidence of inflammation in the small airways with age in rats. A reference database comprising of body weight gain, lung physiological volumes and capacities and an anatomopathological study of lung lesions over 240 Wistar rats from two to 24 -mo, is described. Tidal volume (TV), minute respiratory volume (MRV), and forced vital capacity (FVC) decreased during the first six months of life and then remain constant until 24 -mo of age. The respiratory frequency (Rf) and dynamical compliance (Cdyn) maintain at constant values from 2 to 24- mo of age; the functional residual capacity (FRC) increases in the first 6 -mo and then remains constant up to 24 -mo. It was verified a less intensive inflammation in the small airways with age, when compared with the median and large airways. This study showed the normal parameters for lung volumes and capacities and the incidence of infections for growing and aging male and female rats. The age-related data on these main respiratory parameters in rats would be useful in studies of aging-related disorders using this model and for safety pharmacology studies necessary for the development of drugs.

Constant phycobilisome size in chromatically adapted cells of the cyanobacterium Tolypothrix tenuis, and variation in Nostoc sp

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

Ohki, K.; Gantt, E.; Lipschultz, C.A.

1985-12-01

Phycobilisomes of Tolypothrix tenuis, a cyanobacterium capable of complete chromatic adaptation, were studied from cells grown in red and green light, and in darkness. The phycobilisome size remained constant irrespective of the light quality. The hemidiscoidal phycobilisomes had an average diameter of about 52 nanometers and height of about 33 nanometers, by negative staining. The thickness was equivalent to a physocyanin molecule (about 10 nanometers). The molar ratio of allophycocyanin, relative to other phycobiliproteins always remained at about 1:3. Phycobilisomes from red light grown cells and cells grown heterotrophically in darkness were indistinguishable in their pigment composition, polypeptide pattern, andmore » size. Eight polypeptides were resolved in the phycobilin region (17.5 to 23.5 kilodaltons) by isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Half of these were invariable, while others were variable in green and red light. It is inferred that phycoerythrin synthesis in green light resulted in a one for one substitution of phycocyanin, thus retaining a constant phycobilisome size. Tolypothrix appears to be one of the best examples of phycobiliprotein regulation with wavelength. By contrast, in Nostoc sp., the decrease in phycoerythrin in red light cells was accompanied by a decrease in phycobilisome size but not a regulated substitution.« less

Accelerated Testing Methodology Developed for Determining the Slow Crack Growth of Advanced Ceramics

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Gyekenyesi, John P.

1998-01-01

Constant stress-rate ("dynamic fatigue") testing has been used for several decades to characterize the slow crack growth behavior of glass and structural ceramics at both ambient and elevated temperatures. The advantage of such testing over other methods lies in its simplicity: strengths are measured in a routine manner at four or more stress rates by applying a constant displacement or loading rate. The slow crack growth parameters required for component design can be estimated from a relationship between strength and stress rate. With the proper use of preloading in constant stress-rate testing, test time can be reduced appreciably. If a preload corresponding to 50 percent of the strength is applied to the specimen prior to testing, 50 percent of the test time can be saved as long as the applied preload does not change the strength. In fact, it has been a common, empirical practice in the strength testing of ceramics or optical fibers to apply some preloading (<40 percent). The purpose of this work at the NASA Lewis Research Center is to study the effect of preloading on measured strength in order to add a theoretical foundation to the empirical practice.

Determining the critical relative humidity at which the glassy to rubbery transition occurs in polydextrose using an automatic water vapor sorption instrument.

PubMed

Yuan, Xiaoda; Carter, Brady P; Schmidt, Shelly J

2011-01-01

Similar to an increase in temperature at constant moisture content, water vapor sorption by an amorphous glassy material at constant temperature causes the material to transition into the rubbery state. However, comparatively little research has investigated the measurement of the critical relative humidity (RHc) at which the glass transition occurs at constant temperature. Thus, the central objective of this study was to investigate the relationship between the glass transition temperature (Tg), determined using thermal methods, and the RHc obtained using an automatic water vapor sorption instrument. Dynamic dewpoint isotherms were obtained for amorphous polydextrose from 15 to 40 °C. RHc was determined using an optimized 2nd-derivative method; however, 2 simpler RHc determination methods were also tested as a secondary objective. No statistical difference was found between the 3 RHc methods. Differential scanning calorimetry (DSC) Tg values were determined using polydextrose equilibrated from 11.3% to 57.6% RH. Both standard DSC and modulated DSC (MDSC) methods were employed, since some of the polydextrose thermograms exhibited a physical aging peak. Thus, a tertiary objective was to compare Tg values obtained using 3 different methods (DSC first scan, DSC rescan, and MDSC), to determine which method(s) yielded the most accurate Tg values. In general, onset and midpoint DSC first scan and MDSC Tg values were similar, whereas onset and midpoint DSC rescan values were different. State diagrams of RHc and experimental temperature and Tg and %RH were compared. These state diagrams, though obtained via very different methods, showed relatively good agreement, confirming our hypothesis that water vapor sorption isotherms can be used to directly detect the glassy to rubbery transition. Practical Application: The food polymer science (FPS) approach, pioneered by Slade and Levine, is being successfully applied in the food industry for understanding, improving, and developing food processes and products. However, despite its extreme usefulness, the Tg, a key element of the FPS approach, remains a challenging parameter to routinely measure in amorphous food materials, especially complex materials. This research demonstrates that RHc values, obtained at constant temperature using an automatic water vapor sorption instrument, can be used to detect the glassy to rubbery transition and are similar to the Tg values obtained at constant %RH, especially considering the very different approaches of these 2 methods--a transition from surface adsorption to bulk absorption (water vapor sorption) versus a step change in the heat capacity (DSC thermal method).

Population changes, racial/ethnic disparities, and birth outcomes in Louisiana after Hurricane Katrina.

PubMed

Harville, Emily W; Tran, Tri; Xiong, Xu; Buekens, Pierre

2010-09-01

To examine how the demographic and other population changes affected birth and obstetric outcomes in Louisiana, and the effect of the hurricane on racial disparities in these outcomes. Vital statistics data were used to compare the incidence of low birth weight (LBW) (<2500 g), preterm birth (PTB) (37 weeks' gestation), cesarean section, and inadequate prenatal care (as measured by the Kotelchuck index), in the 2 years after Katrina compared to the 2 years before, for the state as a whole, region 1 (the area around New Orleans), and Orleans Parish (New Orleans). Logistic models were used to adjust for covariates. After adjustment, rates of LBW rose for the state, but preterm birth did not. In region 1 and Orleans Parish, rates of LBW and PTB remained constant or fell. These patterns were all strongest in African American women. Rates of cesarean section and inadequate prenatal care rose. Racial disparities in birth outcomes remained constant or were reduced. Although risk of LBW/PTB remained higher in African Americans, the storm does not appear to have exacerbated health disparities, nor did population shifts explain the changes in birth and obstetric outcomes.

Information on estimating local government highway bonds

DOT National Transportation Integrated Search

1973-06-01

The theory of traffic flow following a lane blockage on a multi-lane freeway has been developed. Numerical results have been obtained and are presented both for the steady state case where the traffic density remains constant and the non-steady state...

GAS EXCHANGE OF ALGAE. I. EFFECTS OF TIME, LIGHT INTENSITY, AND SPECTRAL-ENERGY DISTRIBUTION ON THE PHOTOSYNTHETIC QUOTIENT OF CHLORELLA PYRENOIDOSA.

PubMed

AMMANN, E C; LYNCH, V H

1965-07-01

Continuously growing cultures of Chlorella pyrenoidosa Starr 252, operating at constant density and under constant environmental conditions, produced uniform photosynthetic quotient (PQ = CO(2)/O(2)) and O(2) values during 6 months of observations. The PQ for the entire study was 0.90 +/- 0.024. The PQ remained constant over a threefold light-intensity change and a threefold change in O(2) production (0.90 +/- 0.019). At low light intensities, when the rate of respiration approached the rate of photosynthesis, the PQ became extremely variable. Six lamps of widely different spectral-energy distribution produced no significant change in the PQ (0.90 +/- 0.025). Oxygen production was directly related to the number of quanta available, irrespective of spectral-energy distribution. Such dependability in producing uniform PQ and O(2) values warrants a consideration of algae to maintain a constant gas environment for submarine or spaceship use.

Determination of the kinetics of guanine nucleotide exchange on EF-Tu and EF-Ts: continuing uncertainties.

PubMed

Manchester, Keith L

2004-01-30

An analysis is made of the rate constants for the reactions involving the interactions of EF-Tu, EF-Ts, GDP, and GTP recently derived by Gromadski et al. [Biochemistry 41 (2002) 162]. Though their measured values appear to allow a reasonable rate of nucleotide exchange sufficient to support rates of protein synthesis in vivo, their data underestimate the thermodynamic barrier involved in nucleotide exchange and therefore cannot be considered definitive. A kinetic scheme consistent with the thermodynamic barrier can be achieved by modification of various rate constants, particularly of those involving the release of EF-Ts from EF-Tu.GTP.EF-Ts, but such constants are markedly different from what are experimentally observed. It thus remains impossible at present satisfactorily to model guanine nucleotide exchange on EF-Tu, catalysed by EF-Ts by a double displacement mechanism, with experimentally derived rate constants. Metabolic control analysis has been applied to determine the degree of flux control of the different steps in the pathway.

UAS stealth: target pursuit at constant distance using a bio-inspired motion camouflage guidance law.

PubMed

Strydom, Reuben; Srinivasan, Mandyam V

2017-09-21

The aim of this study is to derive a guidance law by which an unmanned aerial system(s) (UAS) can pursue a moving target at a constant distance, while concealing its own motion. We derive a closed-form solution for the trajectory of the UAS by imposing two key constraints: (1) the shadower moves in such a way as to be perceived as a stationary object by the shadowee, and (2) the distance between the shadower and shadowee is kept constant. Additionally, the theory presented in this paper considers constraints on the maximum achievable speed and acceleration of the shadower. Our theory is tested through Matlab simulations, which validate the camouflage strategy for both 2D and 3D conditions. Furthermore, experiments using a realistic vision-based implementation are conducted in a virtual environment, where the results demonstrate that even with noisy state information it is possible to remain well camouflaged using the constant distance motion camouflage technique.

Construction of exact constants of motion and effective models for many-body localized systems

NASA Astrophysics Data System (ADS)

Goihl, M.; Gluza, M.; Krumnow, C.; Eisert, J.

2018-04-01

One of the defining features of many-body localization is the presence of many quasilocal conserved quantities. These constants of motion constitute a cornerstone to an intuitive understanding of much of the phenomenology of many-body localized systems arising from effective Hamiltonians. They may be seen as local magnetization operators smeared out by a quasilocal unitary. However, accurately identifying such constants of motion remains a challenging problem. Current numerical constructions often capture the conserved operators only approximately, thus restricting a conclusive understanding of many-body localization. In this work, we use methods from the theory of quantum many-body systems out of equilibrium to establish an alternative approach for finding a complete set of exact constants of motion which are in addition guaranteed to represent Pauli-z operators. By this we are able to construct and investigate the proposed effective Hamiltonian using exact diagonalization. Hence, our work provides an important tool expected to further boost inquiries into the breakdown of transport due to quenched disorder.

Comparison of surface temperature in 13-lined ground squirrel (Spermophilus tridecimlineatus) and yellow-bellied marmot (Marmota flaviventris) during arousal from hibernation.

PubMed

Phillips, P K; Heath, J E

2004-08-01

Surface temperatures (Ts) of eight 13-lined ground squirrels and seven yellow-bellied marmots were measured during arousal from hibernation using infrared thermography (IRT) and recorded on videotape. Animals aroused normally in 5 degrees C cold rooms. Body temperatures were recorded during arousal using both cheek pouch and interscapular temperature probes. Warming rate in arousal was exponential. Mean mass specific warming rates show the squirrels warm faster (69.76 degrees C/h/kg) than the marmots (4.49 degrees C/h/kg). Surface temperatures (Ts) for 11 regions were measured every few minutes during arousal. The smaller ground squirrel shows the ability to perfuse distal regions without compromising rise in deep body temperature (Tb). All squirrel Ts's remained low as Tb rose to 18 degrees C, at which point, eyes opened, squirrels became more active and all Ts's rose parallel to Tb. Marmot Ts remained low as Tb rose initially. Each marmot showed a plateau phase where Tb remained constant (mean Tb 20.3+/-1.0 degrees C, duration 9.4+/-4.1 min) during which time all Ts's rose, and then remained relatively constant as Tb again began to rise. An anterior to posterior Ts gradient was evident in the ground squirrel, both body and feet. This gradient was only evident in the feet of the marmots.

Electroosmotically enhanced drying of biomass

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

Banerjee, S.; Law, S.E.

A laboratory system for experimentally characterizing electroosmotic dewatering of biomass has been developed. The system was used to investigate the dewatering at both constant voltage and constant current of two biomass materials, organic humus with peat and composted wastewater sludge (WWS). The moisture content of humus decreased to 22.5% from an initial value of 44.3% wet basis (wb) after 2 h 10 min of electroosmosis at 50 V across a 2.9-cm-thick bed, whereas that of sludge decreased to 54.5% from an initial value of 68.4% after 2 h 20 min at 40 V across the bed. The electrical energy requiredmore » to remove 1 kg of water by constant-voltage electroosmosis of humus varied from 23% to 61%, in the voltage range of 10--50 V, of the thermal energy required to change the same quantity of free water from liquid to vapor state. For WWS, the energy remained constant at a higher value of 88% over the 20--40-V range studied. The flowrate of liquid water out of the bed at constant voltage linearly increased with the applied electric field, and the electrical energy expended in the constant-current dewatering mode was seen to be a quadratic function of time as predicted by classical electrokinetic theory.« less

Employees.

ERIC Educational Resources Information Center

Delon, Floyd G.

While the nature of disputes between school employees and employers remained constant in 1977, the number of cases increased to 300. This chapter discusses some of those cases including Mt. Healthy Community School District v. Doyle, a key decision on employee substantive constitutional rights. General topics covered include discrimination in…

Vector vaccines for control of avian influenza

USDA-ARS?s Scientific Manuscript database

Vaccines play a critical role in the poultry industries efforts at disease control and prevention. However, providing safe, efficacious, and cost-effective vaccines remains a constant issue to the industry. In addition, many viruses undergo mutation in the field requiring vaccine adjustments. Recent...

Is liver SUV stable over time in ¹⁸F-FDG PET imaging?

PubMed

Laffon, Eric; Adhoute, Xavier; de Clermont, Henri; Marthan, Roger

2011-12-01

This work investigated whether (18)F-FDG PET standardized uptake value (SUV) is stable over time in the normal human liver. The SUV-versus-time curve, SUV(t), of (18)F-FDG in the normal human liver was derived from a kinetic model analysis. This derivation involved mean values of (18)F-FDG liver metabolism that were obtained from a patient series (n = 11), and a noninvasive population-based input function was used in each individual. Mean values (±95% reliability limits) of the (18)F-FDG uptake and release rate constant and of the fraction of free tracer in blood and interstitial volume were as follows: K = 0.0119 mL·min(-1)·mL(-1) (±0.0012), k(R) = 0.0065·min(-1) (±0.0009), and F = 0.21 mL·mL(-1) (±0.11), respectively. SUV(t) (corrected for (18)F physical decay) was derived from these mean values, showing that it smoothly peaks at 75-80 min on average after injection and that it is within 5% of the peak value between 50 and 110 min after injection. In the normal human liver, decay-corrected SUV(t) remains nearly constant (with a reasonable ±2.5% relative measurement uncertainty) if the time delay between tracer injection and PET acquisition is in the range of 50-110 min. In current clinical practice, the findings suggest that SUV of the normal liver can be used for comparison with SUV of suspected malignant lesions, if comparison is made within this time range.

PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.

PubMed

Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

2014-10-01

As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. Copyright © 2014 Elsevier Ltd. All rights reserved.

"It's heavenly to be alone!": a room of one's own as a health-promoting resource for women. Results from a qualitative study.

PubMed

Forssén, Annika S K; Carlstedt, Gunilla

2006-01-01

This paper describes strategies developed by women to handle lack of time for themselves, and lack of freedom, in private life. The paper reports on one self-assessed health resource identified in a larger qualitative study on women's paid and unpaid work and health/sickness. Twenty strategically selected women were interviewed, elderly women being chosen to obtain a lifetime perspective. The interviews were audio-taped and analysed according to a phenomenological approach. Expectations had been placed on the interviewees as women: to give care, always to be available for other family members, to adjust to their husbands. Many of them recalled seeking privacy ("a room of one's own") to avoid constant demands and interruptions, and as a refuge from partner domination. This was a conscious health-promoting strategy on their part. A room of one's own did not necessarily mean a physical room, but the right to -- and the possibility of -- a life of one's own. Forms of privacy included gainful employment, a separate bedroom, own social engagements. Family life still demands more from women than from men, putting many women under constant time pressure and without time for themselves. In heterosexual relationships, women frequently feel controlled. Prevailing norms for married women and mothers, causing blame and feelings of guilt, remain obstacles to women wanting "a room of their own". The health resource of having such a room, and strategies for creating one, should be given attention in medical research and practice -- not least in primary care.

Stress Management: A Case Study of Professional Students on Impact of Meditation & Yoga on Stress Levels

ERIC Educational Resources Information Center

Reddy, T. L. Narasimha; Ammani, S.

2013-01-01

Meditation is one of the Five Principles of Yoga. It is the practice by which there is constant observation of the mind. It requires you to focus your mind at one point and make your mind still in order to perceive the "self". Through the practice of Meditation, it will help achieve a greater sense of purpose and strength of will. It…

Adult Education in a Changing Europe: A Survey of Theory and Practice. [L'Education des Adultes dans une Societe en Constante Evolution; Etude sur la Theorie et la Pratique.

ERIC Educational Resources Information Center

Hutchinson, E. M.; And Others

This course was held to review research and investigations undertaken in Europe, their significance for the practice of adult education, and the possibility of cooperative action in the future. Delegates reached conclusions calling for the general review of European adult education, bibliographic services, general and joint research, cooperation,…

Hydrolysis mechanisms for the organopalladium complex [Pd(CNN)P(OMe)3]BF4 in sulfuric acid.

PubMed

García, Begoña; Hoyuelos, Francisco J; Ibeas, Saturnino; Muñoz, María S; Peñacoba, Indalecio; Leal, José M

2009-08-13

The acid-catalyzed hydrolysis of the organopalladium complex [Pd(CNN)P(OMe)3]BF4 species was monitored spectrophotometrically at different sulfuric acid concentrations (3.9 and 11.0 M) in 10% v:v ethanol-water over the 25-45 degrees C temperature range and in 30% and 50% (v/v) ethanol-water at 25 degrees C. Two acidity regions (I and II) could be differentiated. In each of the two regions the kinetic data pairs yielded two different rate constants, k(1obs) and k(2obs), the former being faster. These constants were fitted by an Excess Acidity analysis to different hydrolyses mechanisms: A-1, A-2, and A-SE2. In region I ([H2SO4] < 7.0 M), the k(1obs) values remained constant k(1obs)(av) = 1.6 x 10(-3) s(-1) and the set of k(2obs) values nicely matched an A-SE2 mechanism, yielding a rate-determining constant k(0,ASE2) = 2.4 x 10(-7) M(-1) s(-1). In region II ([H2SO4] > 7.0 M), a switchover was observed from an A-1 mechanism (k(0,A1) = 1.3 x 10(-4) s(-1)) to an A-2 mechanism (k(0,A2) = 3.6 x 10(-3) M(-1) s(-1)). The temperature effect on the rate constants in 10% (v/v) ethanol-water yielded positive DeltaH and negative DeltaS values, except for the A-1 mechanism, where DeltaS adopted positive values throughout. The solvent permittivity effect, epsilonr, revealed that k(1obs)(av) and k(0,A2) dropped with a fall in epsilonr, whereas the k(0,ASE2) value remained unaffected. The set of results deduced is in line with the schemes put forward.

A new atomic force microscope force ramp technique using digital force feedback control reveals mechanically weak protein unfolding events.

PubMed

Kawakami, M; Smith, D A

2008-12-10

We have developed a new force ramp modification of the atomic force microscope (AFM) which can control multiple unfolding events of a multi-modular protein using software-based digital force feedback control. With this feedback the force loading rate can be kept constant regardless the length of soft elastic linkage or number of unfolded polypeptide domains. An unfolding event is detected as a sudden drop in force, immediately after which the feedback control reduces the applied force to a low value of a few pN by lowering the force set point. Hence the remaining folded domains can relax and the subsequent force ramp is applied to relaxed protein domains identically in each case. We have applied this technique to determine the kinetic parameters x(u), which is the distance between the native state and transition state, and α(0), which is the unfolding rate constant at zero force, for the mechanical unfolding of a pentamer of I27 domains of titin. In each force ramp the unfolding probability depends on the number of folded domains remaining in the system and we had to take account of this effect in the analysis of unfolding force data. We obtained values of x(u) and α(0) to be 0.28 nm and 1.02 × 10(-3) s(-1), which are in good agreement with those obtained from conventional constant velocity experiments. This method reveals unfolding data at low forces that are not seen in constant velocity experiments and corrects for the change in stiffness that occurs with most mechanical systems throughout the unfolding process to allow constant force ramp experiments to be carried out. In addition, a mechanically weak structure was detected, which formed from the fully extended polypeptide chain during a force quench. This indicates that the new technique will allow studies of the folding kinetics of previously hidden, mechanically weak species.

CALIBRATION AND TESTING OF SONIC STIMULATION TECHNOLOGIES

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

Roger Turpening; Wayne Pennington; Christopher Schmidt

2005-03-01

In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are (1) a borehole test site that will remain constant and is available all the time and for any length of time, (2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and (3) a set of procedures that ensures that the amplitude and frequency parameters of a widemore » range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 x 10{sup -5} cm/sec and a peak to peak pressure of approx. 2.5 x 10{sup -7} microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. Igor Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.« less

Smoking selectivity among Mexican immigrants to the United States using binational data, 1999-2012.

PubMed

Fleischer, Nancy L; Ro, Annie; Bostean, Georgiana

2017-04-01

Mexican immigrants have lower smoking rates than US-born Mexicans, which some scholars attribute to health selection-that individuals who migrate are healthier and have better health behaviors than their non-migrant counterparts. Few studies have examined smoking selectivity using binational data and none have assessed whether selectivity remains constant over time. This study combined binational data from the US and Mexico to examine: 1) the extent to which recent Mexican immigrants (<10years) in the US are selected with regard to cigarette smoking compared to non-migrants in Mexico, and 2) whether smoking selectivity varied between 2000 and 2012-a period of declining tobacco use in Mexico and the US. We combined repeated cross-sectional US data (n=10.901) on adult (ages 20-64) Mexican immigrants and US-born Mexicans from the 1999/2000 and 2011/2012 National Health Interview Survey, and repeated cross-sectional Mexican data on non-migrants (n=67.188) from the 2000 Encuesta Nacional de Salud and 2012 Encuesta Nacional de Salud y Nutrición. Multinomial logistic regressions, stratified by gender, predicted smoking status (current, former, never) by migration status. At both time points, we found lower overall smoking prevalence among recent US immigrants compared to non-migrants for both genders. Moreover, from the regression analyses, smoking selectivity remained constant between 2000 and 2012 among men, but increased among women. These findings suggest that Mexican immigrants are indeed selected on smoking compared to their non-migrating counterparts, but that selectivity is subject to smoking conditions in the sending countries and may not remain constant over time. Copyright © 2017 Elsevier Inc. All rights reserved.

Seventeen-year trends in spring and autumn phenophases of Betula pubescens in a boreal environment.

PubMed

Poikolainen, Jarmo; Tolvanen, Anne; Karhu, Jouni; Kubin, Eero

2016-08-01

Trends in the timing of spring and autumn phenophases of Betula pubescens were investigated in the southern, middle, and northern boreal zones in Finland. The field observations were carried out at 21 sites in the Finnish National Phenological Network in 1997-2013. The effective temperature sum of the thermal growth period, i.e. the sum of the positive differences between diurnal mean temperatures and 5 °C (ETS1), increased annually on average by 6-7 degree day units. Timing of bud burst remained constant in the southern and middle boreal zones but advanced annually by 0.5 day in the northern boreal zone. The effective temperature sum at bud burst (ETS2) showed no trend in the southern and middle boreal zones, whereas ETS2 increased on average from 20-30 to 50 degree day units in the northern boreal zone, almost to the same level as in the other zones. Increase in ETS2 indicates that the trees did not start their growth in very early spring despite warmer spring temperatures. The timing of leaf colouring and leaf fall remained almost constant in the southern boreal zones, whereas these advanced annually by 0.3 and 0.6 day in the middle boreal zone and by 0.6 and 0.4 day in the northern boreal zone, respectively. The duration of the growth period remained constant in all boreal zones. The results indicate high buffering capacity of B. pubescens against temperature changes. The study also shows the importance of the duration of phenological studies: some trends in spring phenophases had levelled out, while new trends in autumn phases had emerged after earlier studies in the same network for a shorter observation period.

Gene delivery by direct injection (microinjection) using a controlled-flow system.

PubMed

Dean, David A

2006-12-01

INTRODUCTIONThis protocol describes a method for constant-flow microinjection using the Pneumatic PicoPump (World Precision Instruments). This type of system is very simple and can be assembled on a relatively low budget. In this method, a constant flow of sample is delivered from the tip of the pipette, and the amount of sample injected into the cell is determined by how long the pipette remains in the cell. A typical system is composed of a pressure regulator that can be adjusted for two pressures (back pressure and injection pressure), a capillary holder, and a coarse and fine micromanipulator.

Altitude Performance Characteristics of Tail-pipe Burner with Variable-area Exhaust Nozzle

NASA Technical Reports Server (NTRS)

Jansen, Emmert T; Thorman, H Carl

1950-01-01

An investigation was conducted in the NACA Lewis altitude wind tunnel to determine effect of altitude and flight Mach number on performance of tail-pipe burner equipped with variable-area exhaust nozzle and installed on full-scale turbojet engine. At a given flight Mach number, with constant exhaust-gas and turbine-outlet temperatures, increasing altitude lowered the tail-pipe combustion efficiency and raised the specific fuel consumption while the augmented thrust ratio remained approximately constant. At a given altitude, increasing flight Mach number raised the combustion efficiency and augmented thrust ratio and lowered the specific fuel consumption.

The avian embryo responding to microgravity of space flight

NASA Technical Reports Server (NTRS)

Hullinger, Ronald L.

1993-01-01

Of all the many potential and real microenvironmental influences, only gravity would appear to have remained relatively constant and ubiquitous for developing organisms. Histo- and organogenesis as well as differential growth of the embryo and fetus may have evolved with a constant environmental factor of gravity. Chick embryos of 2-day and 9-day stages of incubation were flown in an incubator on the Space Shuttle during a 9-day mission. Significant differences in embryo response to this microgravity environment were observed. This paper offers an analysis and suggests mechanisms which may contribute to these results.

Longitudinal Long-term Magnetic Resonance Imaging and Clinical Follow-up After Single-Row Arthroscopic Rotator Cuff Repair: Clinical Superiority of Structural Tendon Integrity.

PubMed

Heuberer, Philipp R; Smolen, Daniel; Pauzenberger, Leo; Plachel, Fabian; Salem, Sylvia; Laky, Brenda; Kriegleder, Bernhard; Anderl, Werner

2017-05-01

The number of arthroscopic rotator cuff surgeries is consistently increasing. Although generally considered successful, the reported number of retears after rotator cuff repair is substantial. Short-term clinical outcomes are reported to be rarely impaired by tendon retears, whereas to our knowledge, there is no study documenting long-term clinical outcomes and tendon integrity after arthroscopic rotator cuff repair. To investigate longitudinal long-term repair integrity and clinical outcomes after arthroscopic rotator cuff reconstruction. Case series; Level of evidence, 4. Thirty patients who underwent arthroscopic rotator cuff repair with suture anchors for a full-tendon full-thickness tear of the supraspinatus or a partial-tendon full-thickness tear of the infraspinatus were included. Two and 10 years after initial arthroscopic surgery, tendon integrity was analyzed using magnetic resonance imaging (MRI). The University of California, Los Angeles (UCLA) score and Constant score as well as subjective questions regarding satisfaction with the procedure and return to normal activity were used to evaluate short- and long-term outcomes. At the early MRI follow-up, 42% of patients showed a full-thickness rerupture, while 25% had a partial rerupture, and 33% of tendons remained intact. The 10-year MRI follow-up (129 ± 11 months) showed 50% with a total rerupture, while the other half of the tendons were partially reruptured (25%) or intact (25%). The UCLA and Constant scores significantly improved from preoperatively (UCLA total: 50.6% ± 20.2%; Constant total: 44.7 ± 10.5 points) to 2 years (UCLA total: 91.4% ± 16.0% [ P < .001]; Constant total: 87.8 ± 15.3 points [ P < .001]) and remained significantly higher after 10 years (UCLA total: 89.7% ± 15.9% [ P < .001]; Constant total: 77.5 ± 15.6 points [ P < .001]). The Constant total score and Constant strength subscore, but not the UCLA score, were also significantly better at 10 years postoperatively in patients with intact tendons compared with patients with retorn tendons (Constant total: 89.0 ± 7.8 points vs 75.7 ± 14.1 points, respectively [ P = .034]; Constant strength: 18.0 ± 4.9 points vs 9.2 ± 5.2 points, respectively [ P = .006]). The majority of patients rated their satisfaction with the procedure as "excellent" (83.3%), and 87.5% returned to their normal daily activities. Arthroscopic rotator cuff repair showed good clinical long-term results despite a high rate of retears. Nonetheless, intact tendons provided significantly superior clinical long-term outcomes, making the improvement of tendon healing and repair integrity important goals of future research efforts.

Determining the hydraulic properties of saturated, low-permeability geological materials in the laboratory: Advances in theory and practice

USGS Publications Warehouse

Zhang, M.; Takahashi, M.; Morin, R.H.; Endo, H.; Esaki, T.; ,

2002-01-01

The accurate hydraulic characterization of low-permeability subsurface environments has important practical significance. In order to examine this issue from the perspective of laboratory-based approaches, we review some recent advancements in the theoretical analyses of three different laboratory techniques specifically applied to low-permeability geologic materials: constant-head, constant flow-rate and transient-pulse permeability tests. Some potential strategies for effectively decreasing the time required to confidently estimate the permeability of these materials are presented. In addition, a new and versatile laboratory system is introduced that can implement any of these three test methods while simultaneously subjecting a specimen to high confining pressures and pore pressures, thereby simulating in situ conditions at great depths. The capabilities and advantages of this innovative system are demonstrated using experimental data derived from Shirahama sandstone and Inada granite, two rock types widely encountered in Japan.

Flexible and mechanical strain resistant large area SERS active substrates

NASA Astrophysics Data System (ADS)

Singh, J. P.; Chu, Hsiaoyun; Abell, Justin; Tripp, Ralph A.; Zhao, Yiping

2012-05-01

We report a cost effective and facile way to synthesize flexible, uniform, and large area surface enhanced Raman scattering (SERS) substrates using an oblique angle deposition (OAD) technique. The flexible SERS substrates consist of 1 μm long, tilted silver nanocolumnar films deposited on flexible polydimethylsiloxane (PDMS) and polyethylene terephthalate (PET) sheets using OAD. The SERS enhancement activity of these flexible substrates was determined using 10-5 M trans-1,2-bis(4-pyridyl) ethylene (BPE) Raman probe molecules. The in situ SERS measurements on these flexible substrates under mechanical (tensile/bending) strain conditions were performed. Our results show that flexible SERS substrates can withstand a tensile strain (ε) value as high as 30% without losing SERS performance, whereas the similar bending strain decreases the SERS performance by about 13%. A cyclic tensile loading test on flexible PDMS SERS substrates at a pre-specified tensile strain (ε) value of 10% shows that the SERS intensity remains almost constant for more than 100 cycles. These disposable and flexible SERS substrates can be integrated with biological substances and offer a novel and practical method to facilitate biosensing applications.

Factors affecting retention of allied health professionals working with people with disability in rural New South Wales, Australia: discrete choice experiment questionnaire development.

PubMed

Gallego, Gisselle; Dew, Angela; Bulkeley, Kim; Veitch, Craig; Lincoln, Michelle; Bundy, Anita; Brentnall, Jennie

2015-04-21

This paper describes the development of a discrete choice experiment (DCE) questionnaire to identify the factors (attributes) that allied health professionals (AHPs) working with people with disability identify as important to encouraging them to remain practising in rural areas. Focus groups and semi-structured interviews were conducted with 97 purposively selected service providers working with people with disability in rural New South Wales, Australia. Focus groups and interviews were digitally recorded, transcribed, and analysed using a modified grounded theory approach involving thematic analysis and constant comparison. Six attributes that may influence AHPs working with people with disability in rural areas to continue to do so were inductively identified: travel arrangements, work flexibility, professional support, professional development, remuneration, and autonomy of practice. The qualitative research information was combined with a policy review to define these retention factors and ensure that they are amenable to policy changes. The use of various qualitative research methods allowed the development of a policy-relevant DCE questionnaire that was grounded in the experience of the target population (AHPs).

YY v TURKEY: INFERTILITY AS A PRE-CONDITION FOR GENDER CONFIRMATION SURGERY.

PubMed

Dunne, Peter

2015-01-01

In YY v Turkey, the Second Chamber of the European Court of Human Rights (ECtHR) held that Turkey's refusal, over a period of many years, to authorise gender confirmation surgery because the applicant remained capable of procreating was a violation of the right to private life under Art. 8 of the European Convention on Human Rights. The Second Chamber's judgment acknowledges, and gives practical effect to, the 'physical and moral security' of transgender persons. YY has the potential to revolutionise gender confirming health care in Europe and will hopefully ensure that, where individuals do seek to medically transition, they need only access to treatments that are both necessary and desired. The ECtHR's decision may also impact upon the legal recognition of transgender identities. While not the direct focus of the Second Chamber's assessment, legal gender recognition is a constant theme throughout the judgment, and many of the Court's arguments are equally applicable to legal schemes for acknowledging preferred gender. © The Author 2015. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

Synthetic cannabinoids 2015: An update for pediatricians in clinical practice

PubMed Central

Castellanos, Daniel; Gralnik, Leonard M

2016-01-01

Synthetic cannabinoids are a group of substances in the world of designer drugs that have become increasingly popular over the past few years. Synthetic cannabinoids are a chemically diverse group of compounds functionally similar to THC. Since first appearing on the world market a few years ago these compounds have evolved rapidly. Newer more potent analogues have been developed. Identifying youth who abuse these substances can be difficult. Newer forms of consumption have also evolved. These products are now manufactured in products that look like natural cannabis resin and in liquid cartridges used in electronic cigarettes. Synthetic cannabinoids appear to be associated with potentially dangerous health effects that are more severe than that of marijuana. Some synthetic cannabinoid compounds have been associated with serious physical consequences, such as, seizures, myocardial infarction and renal damage. In addition, psychoactive effects, such as aggression, confusion, anxiety and psychosis have also been reported. The diagnosis remains primarily clinical with toxicological confirmation difficult due to manufacturers constantly developing new analogues to avoid detection. Pediatricians are urged to familiarize themselves with these drugs and the typical presentations of patients who use them. PMID:26862498

Molecular Interactions in 1,4-Dioxane, Tetrahydrofuran, and Ethyl Acetate Solutions of 1,1'-Bis(4-isopropyloxyacetylphenoxy)cyclohexane on Reological, Density, and Acoustic Behavior

NASA Astrophysics Data System (ADS)

Dhaduk, B. B.; Patel, Ch. B.; Parsania, P. H.

2017-12-01

Various thermo-acoustical parameters of 1,4-dioxane, tetrahydofuran and ethylacetae solutions of 1,1'-bis(4-isopropyloxyacetylphenoxy)cyclohexane were determined at different temperatures using density, viscosity and ultrasonic speed and correlated with concentration. Linear increase of ultrasonic speed, specific acoustical impedance, Rao's molar sound function, Van der Waals constant and free volume with concentration C and decreased with temperature. Linear decrease of adiabatic compressibility, internal pressure, intermolecular free path length, classical absorption coefficient, and viscous relaxation time with concentration and increased with temperature indicated existence of strong molecular interactions in solutions and further supported by positive values of solvation number. Gibbs free energy of activation decreased with C in all three systems. It is decreased with T in 1,4-dioxane, while increased in tetrahydrofuran and ethyl acetate. Both enthalpy of activation and entropy of activation are increased gradually with C in 1,4-dioxane, while they are negative and remained practically independent of concentration in 1,4-dioxane and tetrahydofuran systems.

Highly Enhanced Raman Scattering on Carbonized Polymer Films.

PubMed

Yoon, Jong-Chul; Hwang, Jongha; Thiyagarajan, Pradheep; Ruoff, Rodney S; Jang, Ji-Hyun

2017-06-28

We have discovered a carbonized polymer film to be a reliable and durable carbon-based substrate for carbon enhanced Raman scattering (CERS). Commercially available SU8 was spin coated and carbonized (c-SU8) to yield a film optimized to have a favorable Fermi level position for efficient charge transfer, which results in a significant Raman scattering enhancement under mild measurement conditions. A highly sensitive CERS (detection limit of 10 -8 M) that was uniform over a large area was achieved on a patterned c-SU8 film and the Raman signal intensity has remained constant for 2 years. This approach works not only for the CMOS-compatible c-SU8 film but for any carbonized film with the correct composition and Fermi level, as demonstrated with carbonized-PVA (poly(vinyl alcohol)) and carbonized-PVP (polyvinylpyrollidone) films. Our study certainly expands the rather narrow range of Raman-active material platforms to include robust carbon-based films readily obtained from polymer precursors. As it uses broadly applicable and cheap polymers, it could offer great advantages in the development of practical devices for chemical/bio analysis and sensors.

Tracheobronchial Manifestations of Aspergillus Infections

PubMed Central

Krenke, Rafal; Grabczak, Elzbieta M.

2011-01-01

Human lungs are constantly exposed to a large number of Aspergillus spores which are present in ambient air. These spores are usually harmless to immunocompetent subjects but can produce a symptomatic disease in patients with impaired antifungal defense. In a small percentage of patients, the trachea and bronchi may be the main or even the sole site of Aspergillus infection. The clinical entities that may develop in tracheobronchial location include saprophytic, allergic and invasive diseases. Although this review is focused on invasive Aspergillus tracheobronchial infections, some aspects of allergic and saprophytic tracheobronchial diseases are also discussed in order to present the whole spectrum of tracheobronchial aspergillosis. To be consistent with clinical practice, an approach basing on specific conditions predisposing to invasive Aspergillus tracheobronchial infections is used to present the differences in the clinical course and prognosis of these infections. Thus, invasive or potentially invasive Aspergillus airway diseases are discussed separately in three groups of patients: (1) lung transplant recipients, (2) highly immunocompromised patients with hematologic malignancies and/or patients undergoing hematopoietic stem cell transplantation, and (3) the remaining, less severely immunocompromised patients or even immunocompetent subjects. PMID:22194666

The Relative Success of a Self-Help and a Group-Based Memory Training Program for Older Adults

PubMed Central

Hastings, Erin C.; West, Robin L.

2011-01-01

This study evaluates self-help and group-based memory training programs to test for their differential impact on memory beliefs and performance. Self-help participants used a manual that presented strategies for name, story, and list recall and practice exercises. Matched content from that same manual was presented by the trainer in 2-hr weekly group sessions for the group-based trainees. Relative to a wait-list control group, most memory measures showed significant gains for both self-help and group-based training, with no significant training condition differences, and these gains were maintained at follow-up. Belief measures showed that locus of control was significantly higher for the self-help and group-based training than the control group; memory self-efficacy significantly declined for controls, increased for group-trained participants, and remained constant in the self-help group. Self-efficacy change in a self-help group may require more opportunities for interacting with peers and/or an instructor emphasizing one's potential for memory change. PMID:19739914

Facilitated transport in European soils from the Euro-soil project

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

Dolfing, J.; Scheltens, S.D.

1999-07-01

The authors studied the response of five reference soils from the European Union (a vertic cambisol, rendzina, dystric cambisol, orthic luvisol, and orthic podzol, also known as Euro-soils 1 to 5) to the addition of HCl and NaOH. For all soils, which were incubated as soil slurries, the amount of organic carbon in solution remained essentially constant upon addition of HCl but increased upon addition of NaOH; that is, it was not the pH of the soil that determined changes in the solubilization of dissolved organic carbon but {Delta}pH. This observation has implications for the design of active soil managementmore » strategies, because increased amounts of dissolved organic carbon in the soil solution pose a risk for leaching of contaminants to deeper soil layers and eventually to the groundwater. In the past, much attention has been paid to the reaction of soils to acidification and changing land use as practiced when agricultural land is taken out of production. The observations reported here indicate that soil alkalization is not necessarily without environmental and toxicological risks.« less

Investigating parameters participating in the infant respiratory control system attractor.

PubMed

Terrill, Philip I; Wilson, Stephen J; Suresh, Sadasivam; Cooper, David M; Dakin, Carolyn

2008-01-01

Theoretically, any participating parameter in a non-linear system represents the dynamics of the whole system. Taken's time delay embedding theory provides the fundamental basis for allowing non-linear analysis to be performed on physiological, time-series data. In practice, only one measurable parameter is required to be measured to convey an accurate representation of the system dynamics. In this paper, the infant respiratory control system is represented using three variables-a digitally sampled respiratory inductive plethysmography waveform, and the derived parameters tidal volume and inter-breath interval time series data. For 14 healthy infants, these data streams were analysed using recurrence plot analysis across one night of sleep. The measured attractor size of these variables followed the same qualitative trends across the nights study. Results suggest that the attractor size measures of the derived IBI and tidal volume are representative surrogates for the raw respiratory waveform. The extent to which the relative attractor sizes of IBI and tidal volume remain constant through changing sleep state could potentially be used to quantify pathology, or maturation of breathing control.

Effect of in-situ disturbance within the soil mass on the stress-strain behaviour of silty soil

NASA Astrophysics Data System (ADS)

Noor, Sarah T.; Rabika Rahman, SS; Nahar, Sabiqun

2018-04-01

To date, different techniques have been evolved to collect soil in undisturbed condition so that the in-situ soil behaviour can be determined by carrying out laboratory tests. For the same reason, the execution of undisturbed soil sampling in practice is given a lot of efforts. However, this study brings the fact into consideration that the in-situ soil condition may not remain constant, rather it might vary time to time, because of different internal or external reasons. For example, the internal stress state of soil layers, existing below or above the swelling soil layer, become modified during shrinking and swelling resulting from drying and wetting of swelling clay, respectively. Further, foundations of building may transfer cyclic loads (generated by vibration installed in the building) to the soil below the foundation. Therefore, this study investigates the effects of stress-strain behaviour due to the disturbances on the shear strength of the soil with respect to that of undisturbed specimens. The shear strength of disturbed soil shows deviation from that of undisturbed specimen depending on the different parameters defining the severity of disturbance.

Synergistic effect of alloying elements doping and external pressure on the elastic property of Ni{sub 3}Al: A first-principles study

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

Li, C., E-mail: lichun@nwpu.edu.cn; Shang, J.; Yue, Z.

2015-07-15

In this paper, the basic electronic structures and elastic properties of Ni{sub 3}Al doping with alloying elements (Re, Cr, and Mo) under different pressures have been investigated using first-principles calculations based on density functional theory. It is shown that both alloying elements and external applied pressure contribute positively to the elastic properties of Ni{sub 3}Al, and the configurations of the compounds remain almost unchanged. The calculated elastic constants and moduli increase linearly with the pressure increasing from 0 and 40 GPa. Among the alloying elements studied in the present work, Re exhibits the most significant effect compared with the othermore » elements, showing its practical importance. Especially, if both alloying elements doping and pressure effects are considered simultaneously, which has not been considered previously, the studied compounds exhibit an even better elastic property than the simple superposition of the two influences. Such synergistic effect demonstrates promising applications of Ni-based single crystal superalloys in possible extreme mechanical environments.« less

Monitoring the effects of storage in caviar from farmed Acipenser transmontanus using chemical, SEM, and NMR methods.

PubMed

Gussoni, Maristella; Greco, Fulvia; Vezzoli, Alessandra; Paleari, Maria Antonietta; Moretti, Vittorio Maria; Beretta, Giuseppe; Caprino, Fabio; Lanza, Barbara; Zetta, Lucia

2006-09-06

The effects of storage at 4 degrees C on the quantity and quality of chemical components in the caviar from farmed Acipenser transmontanus have been analyzed by SEM, chemical methods, and NMR and MRI techniques. Particular attention has been focused on the lipid components, the distribution and mobility of which were strongly affected by the storage time. MRI and relaxation data indicated that lipids are endowed with two different mobility regimes, one slow (short T1) and one fast (long T1), both lengthening with the storage time. Chemical analysis assessed a total fat content that remained practically unchanged and a constant fatty acid composition during the total storage time. The combination of the two methods allowed one (a) to suppose that a mechanism of lipid hydrolysis (faster in unsalted than in salted eggs) is still occurring during storage of caviar at 4 degrees C for up to approximately 4 months and (b) to exclude that an intensive oxidative process is active in the same storage period.

The overwhelming role of soil N2O emissions in net greenhouse gas balance of the U.S. Corn Belt: Modeling estimate of nitrogen fertilizer impacts

NASA Astrophysics Data System (ADS)

Lu, C.; Yu, Z.; Cao, P.; Tian, H.

2017-12-01

The Corn Belt of the Midwestern U.S. is one of the most productive systems in the world during the growing season, with gross primary production exceeding even that of the Amazon forests. Fueled by increased commodity prices in the late 2000s, the area in corn and soybean in the U.S. has reached record highs with most of the newly added cropland converted from grasslands, wetland, and Conservation Reserve Program land. Intensive management practices, such as fertilizer use, irrigation, tillage, residue removal etc., have been implemented following cropland expansion to maximize crop yield from converted marginal land or from more monoculture production. The Corn Belt has been recognized as one of the major contributors to carbon sinks in the U.S., partially because crop harvest and residue removal reduced soil respiration. In the meanwhile, 75% of the total N2O emission in the U.S. comes from agriculture, among which the Corn Belt is the major source due to nitrogen management, and has large potential of climate mitigation. However, it remains far from certain how intensive cropland expansion and management practices in this region have affected soil carbon accumulation and non-CO2 GHG emissions. In this study, by using a process-based land ecosystem model, Dynamic Land Ecosystem Model (DLEM), we investigated the impacts of nitrogen fertilizer use on soil carbon accumulation and direct N2O emissions across the U.S. Corn Belt. Surprisingly, we found N fertilizer-induced SOC storage continued shrinking after the 1980s while N2O emissions remains relatively constant. The N fertilizer use led to a net greenhouse gas release since 2000 in both the western and eastern Corn Belt, contributing to climate warming. This study implies an increasing importance of nitrogen management for both agricultural production and climate mitigation.

The effect of long-range order on the elastic properties of Cu3Au

NASA Astrophysics Data System (ADS)

Wang, Gui-Sheng; Krisztina Delczeg-Czirjak, Erna; Hu, Qing-Miao; Kokko, Kalevi; Johansson, Börje; Vitos, Levente

2013-02-01

Ab initio calculations, based on the exact muffin-tin orbitals method are used to determine the elastic properties of Cu-Au alloys with Au/Cu ratio 1/3. The compositional disorder is treated within the coherent potential approximation. The lattice parameters and single-crystal elastic constants are calculated for different partially ordered structures ranging from the fully ordered L12 to the random face centered cubic lattice. It is shown that the theoretical elastic constants follow a clear trend with the degree of chemical order: namely, C11 and C12 decrease, whereas C44 remains nearly constant with increasing disorder. The present results are in line with the experimental findings that the impact of the chemical ordering on the fundamental elastic parameters is close to the resolution of the available experimental and theoretical tools.

International Committee for Monitoring Assisted Reproductive Technologies world report: Assisted Reproductive Technology 2008, 2009 and 2010.

PubMed

Dyer, S; Chambers, G M; de Mouzon, J; Nygren, K G; Zegers-Hochschild, F; Mansour, R; Ishihara, O; Banker, M; Adamson, G D

2016-07-01

What were utilization, outcomes and practices in assisted reproductive technology (ART) globally in 2008, 2009 and 2010? Global utilization and effectiveness remained relatively constant despite marked variations among countries, while the rate of single and frozen embryo transfers (FETs) increased with a concomitant slight reduction in multiple birth rates. ART is widely practised in all regions of the world. Monitoring utilization, an approximation of availability and access, as well as effectiveness and safety is an important component of universal access to reproductive health. This is a retrospective, cross-sectional survey on utilization, effectiveness and safety of ART procedures performed globally from 2008 to 2010. Between 58 and 61 countries submitted data from a total of nearly 2500 ART clinics each year. Aggregate country data were processed and analyzed based on forms and methods developed by the International Committee for Monitoring Assisted Reproductive Technologies (ICMART). Results are presented at country, regional and global level. For the years 2008, 2009 and 2010, >4 461 309 ART cycles were initiated, resulting in an estimated 1 144 858 babies born. The number of aspirations increased by 6.4% between 2008 and 2010, while FET cycles increased by 27.6%. Globally, ART utilization remained relatively constant at 436 cycles/million in 2008 and 474 cycles/million population in 2010, but with a wide country range of 8-4775 cycles/million population. ICSI remained constant at around 66% of non-donor aspiration cycles. The IVF/ICSI combined delivery rate (DR) per fresh aspiration was 19.8% in 2008; 19.7% in 2009 and 20.0% in 2010, with corresponding DRs for FET of 18.8, 19.7 and 20.7%. In fresh non-donor cycles, single embryo transfer increased from 25.7% in 2008 to 30.0% in 2010, while the average number of embryos transferred fell from 2.1 to 1.9, again with wide regional variation. The rates of twin deliveries following fresh non-donor transfers were, in 2008, 2009 and 2010, 21.8, 20.5 and 20.4%, respectively, with a corresponding triplet rate of 1.3, 1.0 and 1.1%. Fresh IVF and ICSI carried a perinatal mortality rate per 1000 births of 22.8 (2008), 19.2 (2009) and 21.0 (2010), compared with 15.1, 12.8 and 14.6/1000 births following FET in the same periods of observation. The proportion of women aged 40 years or older undergoing non-donor ART increased from 20.8 to 23.2% from 2008 to 2010. The data presented are reliant on the quality and completeness of data submitted by individual countries. This report covers approximately two-thirds of the world ART activity. The ICMART World Reports provide the most comprehensive global statistical census and review of ART utilization, effectiveness, safety and quality. While ART treatment continues to increase globally, the wide disparities in access to treatment and embryo transfer practices warrant attention by clinicians and policy makers. The authors declare no conflict of interest and no specific support from any organizations in relation to this manuscript. ICMART acknowledges financial support from the following organizations: American Society for Reproductive Medicine; European Society for Human Reproduction and Embryology; Fertility Society of Australia; Japan Society for Reproductive Medicine; Japan Society of Fertilization and Implantation; Red Latinoamericana de Reproduccion Asistida; Society for Assisted Reproductive Technology; Government of Canada (Research grant), Ferring Pharmaceuticals (Grant unrelated to World Reports). not applicable. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Electrical Properties for Phenolic Isocyanate-Modified Bisphenol-Based Epoxy Resins Comprising Benzoate Group.

PubMed

Lee, Eun Yong; Chae, Il Seok; Park, Dongkyung; Suh, Hongsuk; Kang, Sang Wook

2016-03-01

Epoxy resin has been required to have a low dielectric constant (D(k)), low dissipation factor (Df), low coefficient of thermal expansion (CTE), low water absorption, high mechanical, and high adhesion properties for various applications. A series of novel phenolic isocyanate-modified bisphenol-based epoxy resins comprising benzoate group were prepared for practical electronic packaging applications. The developed epoxy resins showed highly reduced dielectric constants (D(k)-3.00 at 1 GHz) and low dissipation values (Df-0.014 at 1 GHz) as well as enhanced thermal properties.

Toward a Better Understanding of Within-School Minority Student Resegregation: A Research Agenda.

ERIC Educational Resources Information Center

Meier, Ken J.; And Others

Despite years of litigation the desegregation of United States public schools remains unfinished. Even after court-ordered desegregation, a school district may remain segregated through various practices such as ability grouping and selective discipline of minority children. These second generation discrimination or resegregation practices have an…

"Wasted down There": Policy and Practice with the Under-Threes

ERIC Educational Resources Information Center

Clark, Rory McDowall; Baylis, Sue

2012-01-01

Although frameworks now exist for quality provision for under-threes, discourses underpinning policy remain conflicted. The split between care and education is still firmly entrenched in provision and a gap remains between rhetoric and practice. This paper explores how Early Years Professional Status, which requires practitioners to engage…

Clinical biochemistry of pregnant and nursing mares.

PubMed

Harvey, John W; Pate, Melanie G; Kivipelto, Jan; Asquith, Richard L

2005-09-01

Pregnancy and lactation result in increased metabolic demands. Although homeostatic mechanisms function to keep substances in blood at relatively constant levels, some changes in the concentrations of routine clinical chemistry analytes are likely to occur. The purpose of this study was to determine what physiological changes occur in serum clinical biochemistry analytes in pregnant and nursing mares, and to determine whether the changes were substantial enough to warrant separate reference intervals for pregnant or lactating horses. Forty-two Quarter Horse, Thoroughbred, Saddlebred, Standardbred and Morgan mares were entered into the study while pregnant. They were bled once each month through birth. Studies were continued on 20 mares until their foals were weaned. Test results were tabulated by time before or after birth. Serum biochemistry values were determined by standard methods using automated analyzers. Test results were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks. If a significant difference was found (P<.05), Dunn's multiple comparison procedure was performed on all pairs. Results from pregnant and nursing mares also were compared with a reference group of 19 open, nonlactating mares. Serum triglyceride, potassium, creatinine, and total bilirubin concentrations were lower during lactation than during pregnancy. Serum calcium concentration also was slightly decreased at 2 time points during lactation. Triglyceride concentration was highest during midgestation, while bilirubin and creatinine values increased, and potassium and calcium remained constant during pregnancy. Serum urea concentration also remained constant during pregnancy but increased during lactation. Serum phosphate concentration was lowest during midgestation and highest during lactation. Total CO2 values were highest, and anion gaps were lowest, during midgestation. No significant differences were found in serum albumin, globulin, albumin:globulin ratio, total protein, or glucose values. When compared with the reference group of open mares, serum triglyceride, potassium, bilirubin, and total CO2 concentrations were lower, and anion gap was higher in horses that were nursing. Although most biochemical values remained relatively constant, significant differences were observed during pregnancy and lactation. Changes in the concentrations of triglycerides, potassium, bilirubin, total CO2, and anion gap during lactation were substantial enough to warrant separate reference intervals for lactating horses.

An exploration of how clinician attitudes and beliefs influence the implementation of lifestyle risk factor management in primary healthcare: a grounded theory study

PubMed Central

Laws, Rachel A; Kemp, Lynn A; Harris, Mark F; Davies, Gawaine Powell; Williams, Anna M; Eames-Brown, Rosslyn

2009-01-01

Background Despite the effectiveness of brief lifestyle intervention delivered in primary healthcare (PHC), implementation in routine practice remains suboptimal. Beliefs and attitudes have been shown to be associated with risk factor management practices, but little is known about the process by which clinicians' perceptions shape implementation. This study aims to describe a theoretical model to understand how clinicians' perceptions shape the implementation of lifestyle risk factor management in routine practice. The implications of the model for enhancing practices will also be discussed. Methods The study analysed data collected as part of a larger feasibility project of risk factor management in three community health teams in New South Wales (NSW), Australia. This included journal notes kept through the implementation of the project, and interviews with 48 participants comprising 23 clinicians (including community nurses, allied health practitioners and an Aboriginal health worker), five managers, and two project officers. Data were analysed using grounded theory principles of open, focused, and theoretical coding and constant comparative techniques to construct a model grounded in the data. Results The model suggests that implementation reflects both clinician beliefs about whether they should (commitment) and can (capacity) address lifestyle issues. Commitment represents the priority placed on risk factor management and reflects beliefs about role responsibility congruence, client receptiveness, and the likely impact of intervening. Clinician beliefs about their capacity for risk factor management reflect their views about self-efficacy, role support, and the fit between risk factor management ways of working. The model suggests that clinicians formulate different expectations and intentions about how they will intervene based on these beliefs about commitment and capacity and their philosophical views about appropriate ways to intervene. These expectations then provide a cognitive framework guiding their risk factor management practices. Finally, clinicians' appraisal of the overall benefits versus costs of addressing lifestyle issues acts to positively or negatively reinforce their commitment to implementing these practices. Conclusion The model extends previous research by outlining a process by which clinicians' perceptions shape implementation of lifestyle risk factor management in routine practice. This provides new insights to inform the development of effective strategies to improve such practices. PMID:19825189

Safety of High Ground Transportation Systems - Human Factors Phase I: Function Analyses and Theoretical Considerations

DOT National Transportation Integrated Search

1994-10-01

Although the speed of guided ground transportation continues to increase, the reaction : time as well as the sensory and information processing capacities of on- and off-board : operators remain constant. This report, the first of two examining criti...

No increase in brain cancer rates during period of expanding cell phone use

Cancer.gov

In a new examination of United States cancer incidence data, investigators at the National Cancer Institute (NCI) reported that incidence trends have remained roughly constant for glioma, the main type of brain cancer hypothesized to be related to cell ph

MODELING SUBSTRATE TRANSPORT INTO BIOFILMS: ROLE OF MULTIPLE IONS AND PH EFFECTS

EPA Science Inventory

Steady-state substrate utilization in biofilms has traditionally been modeled by coupling Fickian diffusion with Monod reaction kinetics. An inherent assumption in most of the previous models was that the pH remains constant within the biofilm. Experiments have shown differences ...

Immune responses of poultry to newcastle disease virus

USDA-ARS?s Scientific Manuscript database

Newcastle disease (ND) remains a constant threat to poultry producers worldwide, in spite of the availability and global employment of ND vaccinations since the 1950s. Strains of Newcastle disease virus (NDV) belong to the order Mononegavirales, family Paramyxoviridae, and genus Avulavirus, are cont...

Words of Power: Voices from Indian America.

ERIC Educational Resources Information Center

Hill, Norbert S., Jr., Ed.

This book represents a compilation of past and contemporary quotations by American Indians that reflect Indian philosophy and traditional knowledge. By including contemporary sayings, the book demonstrates that while peoples and conditions have changed, the basic perspectives of Indian peoples remain constant. Quotations cover values; spirituality…

RED BLOOD CELL PRESERVATION.

DTIC Science & Technology

red cells were assayed by ion exchange chromatography. The O-day 2,3- diphosphoglycerate concentrations of the ACD-AP bloods were below the normal...adenosine or guanosine. After a small initial increase, the ADP levels remained fairly constant. The AMP values increased as the ATP decreased and in

Retrieving marine inherent optical properties from satellites using temperature and salinity-dependent backscattering by seawater.

PubMed

Werdell, P Jeremy; Franz, Bryan A; Lefler, Jason T; Robinson, Wayne D; Boss, Emmanuel

2013-12-30

Time-series of marine inherent optical properties (IOPs) from ocean color satellite instruments provide valuable data records for studying long-term time changes in ocean ecosystems. Semi-analytical algorithms (SAAs) provide a common method for estimating IOPs from radiometric measurements of the marine light field. Most SAAs assign constant spectral values for seawater absorption and backscattering, assume spectral shape functions of the remaining constituent absorption and scattering components (e.g., phytoplankton, non-algal particles, and colored dissolved organic matter), and retrieve the magnitudes of each remaining constituent required to match the spectral distribution of measured radiances. Here, we explore the use of temperature- and salinity-dependent values for seawater backscattering in lieu of the constant spectrum currently employed by most SAAs. Our results suggest that use of temperature- and salinity-dependent seawater spectra elevate the SAA-derived particle backscattering, reduce the non-algal particles plus colored dissolved organic matter absorption, and leave the derived absorption by phytoplankton unchanged.

Retrieving Marine Inherent Optical Properties from Satellites Using Temperature and Salinity-dependent Backscattering by Seawater

NASA Technical Reports Server (NTRS)

Werdell, Paul J.; Franz, Bryan Alden; Lefler, Jason Travis; Robinson, Wayne D.; Boss, Emmanuel

2013-01-01

Time-series of marine inherent optical properties (IOPs) from ocean color satellite instruments provide valuable data records for studying long-term time changes in ocean ecosystems. Semi-analytical algorithms (SAAs) provide a common method for estimating IOPs from radiometric measurements of the marine light field. Most SAAs assign constant spectral values for seawater absorption and backscattering, assume spectral shape functions of the remaining constituent absorption and scattering components (e.g., phytoplankton, non-algal particles, and colored dissolved organic matter), and retrieve the magnitudes of each remaining constituent required to match the spectral distribution of measured radiances. Here, we explore the use of temperature- and salinity-dependent values for seawater backscattering in lieu of the constant spectrum currently employed by most SAAs. Our results suggest that use of temperature- and salinity-dependent seawater spectra elevate the SAA-derived particle backscattering, reduce the non-algal particles plus colored dissolved organic matter absorption, and leave the derived absorption by phytoplankton unchanged.

Process-based quality for thermal spray via feedback control

NASA Astrophysics Data System (ADS)

Dykhuizen, R. C.; Neiser, R. A.

2006-09-01

Quality control of a thermal spray system manufacturing process is difficult due to the many input variables that need to be controlled. Great care must be taken to ensure that the process remains constant to obtain a consistent quality of the parts. Control is greatly complicated by the fact that measurement of particle velocities and temperatures is a noisy stochastic process. This article illustrates the application of quality control concepts to a wire flame spray process. A central feature of the real-time control system is an automatic feedback control scheme that provides fine adjustments to ensure that uncontrolled variations are accommodated. It is shown how the control vectors can be constructed from simple process maps to independently control particle velocity and temperature. This control scheme is shown to perform well in a real production environment. We also demonstrate that slight variations in the feed wire curvature can greatly influence the process. Finally, the geometry of the spray system and sensor must remain constant for the best reproducibility.

Methane yields and methanogenic community changes during co-fermentation of cattle slurry with empty fruit bunches of oil palm.

PubMed

Walter, Andreas; Franke-Whittle, Ingrid H; Wagner, Andreas O; Insam, Heribert

2015-01-01

The biomethane potential and structural changes of the methanogenic community in a solid-state anaerobic digestion process co-digesting cattle slurry and empty fruit bunches were investigated under mesophilic (37°C) and thermophilic (55°C) conditions. Phylogenetic microarrays revealed the presence of two hydrogenotrophic genera (Methanoculleus and Methanobrevibacter) and one acetoclastic genus (Methanosarcina). Methanosarcina numbers were found to increase in both mesophilic and thermophilic treatments of empty fruit bunches. Methanobrevibacter, which dominated in the cattle slurry, remained constant during anaerobic digestion (AD) at 37°C and decreased in numbers during digestion at 55°C. Numbers of Methanoculleus remained constant at 37°C and increased during the thermophilic digestion. Physicochemical data revealed non-critical concentrations for important monitoring parameters such as total ammonia nitrogen, free ammonia nitrogen and volatile fatty acids in all treatments after AD. The biomethane potential of empty fruit bunches was higher under thermophilic conditions than under mesophilic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Squeezing flow viscometry for nonelastic semiliquid foods--theory and applications.

PubMed

Campanella, Osvaldo H; Peleg, Micha

2002-01-01

In most conventional rheometers, notably the coaxial cylinders and capillary viscometers, the food specimen is pressed into a narrow gap and its structure is altered by uncontrolled shear. Also, most semiliquid foods exhibit slip, and consequently the measurements do not always reflect their true rheological properties. A feasible solution to these two problems is squeezing flow viscometry where the specimen, practically intact and with or without suspended particles, is squeezed between parallel plates. The outward flow pattern mainly depends on the friction between the fluid and plates or its absence ("lubricated squeezing flow"). Among the possible test geometries, the one of constant area and changing volume is the most practical for foods. The test can be performed at a constant displacement rate using common Universal Testing Machines or under constant loads (creep array). The tests output is in the form of a force-height, force-time, or height-time relationship, from which several rheological parameters can be derived. With the current state of the art, the method can only be applied at small displacement rates. Despite the method's crudeness, its results are remarkably reproducible and sensitive to textural differences among semiliquid food products. The flow patterns observed in foods do not always follow the predictions of rheological models originally developed for polymer melts because of the foods' unique microstructures. The implications of these discrepancies and the role that artifacts may play are evaluated in light of theoretical and practical considerations. The use of squeezing flow viscometry to quantify rheological changes that occur during a product's handling and to determine whether they are perceived sensorily is suggested.

Dielectric properties of soils as a function of moisture content

NASA Technical Reports Server (NTRS)

Cihlar, J.; Ulaby, F. T.

1974-01-01

Soil dielectric constant measurements are reviewed and the dependence of the dielectric constant on various soil parameters is determined. Moisture content is given special attention because of its practical significance in remote sensing and because it represents the single most influential parameter as far as soil dielectric properties are concerned. Relative complex dielectric constant curves are derived as a function of volumetric soil water content at three frequencies (1.3 GHz, 4.0 GHz, and 10.0 GHz) for each of three soil textures (sand, loam, and clay). These curves, presented in both tabular and graphical form, were chosen as representative of the reported experimental data. Calculations based on these curves showed that the power reflection coefficient and emissivity, unlike skin depth, vary only slightly as a function of frequency and soil texture.

Cavity resonator for dielectric measurements of high-ɛ, low loss materials, demonstrated with barium strontium zirconium titanate ceramics

NASA Astrophysics Data System (ADS)

Marksteiner, Quinn R.; Treiman, Michael B.; Chen, Ching-Fong; Haynes, William B.; Reiten, M. T.; Dalmas, Dale; Pulliam, Elias

2017-06-01

A resonant cavity method is presented which can measure loss tangents and dielectric constants for materials with dielectric constant from 150 to 10 000 and above. This practical and accurate technique is demonstrated by measuring barium strontium zirconium titanate bulk ferroelectric ceramic blocks. Above the Curie temperature, in the paraelectric state, barium strontium zirconium titanate has a sufficiently low loss that a series of resonant modes are supported in the cavity. At each mode frequency, the dielectric constant and loss tangent are obtained. The results are consistent with low frequency measurements and computer simulations. A quick method of analyzing the raw data using the 2D static electromagnetic modeling code SuperFish and an estimate of uncertainties are presented.

Concepts of advanced practice: what does it mean?

PubMed

Pearson, Helen

'Advanced practice nursing' may be a familiar concept, but a definition of advanced practice, its scope and its responsibilities, remains elusive. This article discusses the origins of advanced practice, and its practical meaning for nurses working in the NHS today.

Overcoming gaps and bottlenecks to advance precision agriculture

USDA-ARS?s Scientific Manuscript database

Maintaining a clear understanding of the technology gaps, knowledge needs, and training bottlenecks is required for improving adoption of precision agriculture. As an industry, precision agriculture embraces tools, methods, and practices that are constantly changing, requiring industry, education, a...

Modification of LRFD resistance factors based on site variability : final report, November 2009.

DOT National Transportation Integrated Search

2009-11-01

Current practice by the Florida Department of Transportation (FDOT), Federal Highway Administration (FHWA), and American Association of State Highway Transportation Officials (AASHTO) for deep foundation design is to use a constant load and resistanc...

'It's showed me the skills that he has': pharmacists' and mentors' views on pharmacist supplementary prescribing.

PubMed

Lloyd, Fran; Parsons, Carole; Hughes, Carmel M

2010-02-01

Supplementary prescribing has seen pharmacists assume greater responsibility for prescribing in collaboration with doctors. This study explored the context and experiences, in relation to the practice of supplementary prescribing, of pharmacists and physicians (who acted as their training mentors) at least 12 months after pharmacists had qualified as supplementary prescribers. The setting was primary and secondary healthcare sectors in Northern Ireland. Pharmacists and mentors who had participated in a pre-training study were invited to take part. All pharmacists (n = 47) were invited to participate in focus groups, while mentors (n = 35) were asked to participate in face-to-face semi-structured interviews. The research took place between May 2005 and September 2007. All discussions and interviews were audiotaped, transcribed and analysed using constant comparison. Nine pharmacist focus groups were convened (number per group ranging from three to six; total n = 40) and 31 semi-structured interviews with mentors were conducted. The six main themes that emerged were optimal practice setting, professional progression for prescribing pharmacists, outcomes for prescribing pharmacists, mentors and patients, relationships, barriers to implementation and the future of pharmacist prescribing. Where practised, pharmacist prescribing had been accepted, worked best for chronic disease management, was perceived to have reduced doctors' workload and improved continuity of care for patients. However, three-quarters of pharmacists qualified to practise as supplementary prescribers were not actively prescribing, largely due to logistical and organisational barriers rather than inter-professional tensions. Independent prescribing was seen as contentious by mentors, particularly because of the diagnostic element. Supplementary prescribing has been successful where it has been implemented but a number of barriers remain which are preventing the wider acceptance of this practice innovation.

Retaining vets in farm animal practice: a cross-sectional study.

PubMed

Adam, K; Baillie, S; Rushton, J

2015-06-20

Concerns have been raised about a potential shortage of farm animal vets in the UK. There is no apparent lack of new graduates willing to work with farm animals, but practices report difficulties in recruiting and retaining experienced farm animal vets. Retention of vets in farm animal practice has been identified as a key issue for the sustainability of veterinary businesses and livestock health. A cross-sectional study design was used to identify factors associated with vets remaining in farm animal practice. Data were collected via an online questionnaire covering employment, education, personal background and future plans. The target population was vets with experience of farm animal work in the UK. 380 responses were included in the analysis. Working in a practice where accommodation was provided and an increasing number of years since graduation were associated with significantly lower odds of remaining in farm animal practice, while working in a practice where staff appraisals were carried out; coming from a family with a commercial farm; spending more time on farm work and being on call with an experienced vet in the first job after graduation increased the odds of remaining in farm work. Gender was not significantly associated with retention. British Veterinary Association.

Practical Considerations for Using Constant Force Springs in Space-Based Mechanisms

NASA Technical Reports Server (NTRS)

Williams, R. Brett; Fisher, Charles D.; Gallon, John C.

2013-01-01

Mechanical springs are a common element in mechanism from all walks of life; cars, watches, appliances, and many others. These springs generally exhibit a linear relationship between force and deflection. In small mechanisms, deflections are small so the variation in spring force between one position and another are generally small and do not influence the design or functionality of the device. However, as the spacecraft industry drives towards larger, deployable satellites, the distances a spring or springs must function over can become considerable so much so that the structural integrity of the device may be impacted. As such, an increasingly common mechanism element is the constant force spring- one that provides a constant force regardless of deflection. These elements are commonly in the conceptual design phase to deal with system-level large deflections, but in the detailed design or integration test phase they can pose significant implementation issues. This article addresses some of the detailed issues in order for these constant force springs to be properly designed into space systems.

Kinetic analysis of volatile formation in milk subjected to pressure-assisted thermal treatments.

PubMed

Vazquez-Landaverde, P A; Qian, M C; Torres, J A

2007-09-01

Volatile formation in milk subjected to pressure-assisted thermal processing (PATP) was investigated from a reaction kinetic analysis point of view to illustrate the advantages of this technology. The concentration of 27 volatiles of different chemical class in milk subjected to pressure, temperature, and time treatments was fitted to zero-, 1st-, and 2nd-order chemical reaction models. Temperature and pressure effects on rate constants were analyzed to obtain activation energy (E(a)) and activation volume (deltaV*) values. Hexanal, heptanal, octanal, nonanal, and decanal followed 1st-order kinetics with rate constants characterized by E(a) values decreasing with pressure reflecting negative deltaV* values. Formation of 2-methylpropanal, 2,3-butanedione, and hydrogen sulfide followed zero-order kinetics with rate constants increasing with temperature but with unclear pressure effects. E(a) values for 2-methylpropanal and 2,3-butanedione increased with pressure, that is, deltaV* > 0, whereas values for hydrogen sulfide remained constant, that is, deltaV* = 0. The concentration of all other volatiles, including methanethiol, remained unchanged in pressure-treated samples, suggesting large negative deltaV* values. The concentration of methyl ketones, including 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 2-nonanone, 2-decanone, and 2-undecanone, was independent of pressure and pressure-holding time. PATP promoted the formation of few compounds, had no effect on some, and inhibited the formation of volatiles reported to be factors of the consumer rejection of "cooked" milk flavor. The kinetic behavior observed suggested that new reaction formation mechanisms were not likely involved in volatile formation in PATP milk. The application of the Le Chatelier principle frequently used to explain the high quality of pressure-treated foods, often with no supporting experimental evidence, was not necessary.

Using Labor Market Information in Program Development and Evaluation

ERIC Educational Resources Information Center

Lebesch, Anna M.

2012-01-01

The community college environment is complex and dynamic, requiring constant monitoring. To ensure that workforce education, a core component of community colleges' missions, remains aligned with colleges' environments, responsive to employers' needs, suited to students' interests and abilities, and current in content and technology, it is…

When Change Is the Only Constant.

ERIC Educational Resources Information Center

Williamson, Samuel R.

1996-01-01

Many higher education institutions are spending money on information technologies in order to remain competitive, but often small liberal arts colleges have difficulty doing so. Examines the roles technology plays and misconceptions related to costs and productivity, and presents ideas on how faculty can cope with technological change while…

Safety of High Speed Guided Ground Transportation Systems: Human Factors Phase I: Function Analyses and Theoretical Considerations

DOT National Transportation Integrated Search

1994-10-01

Although the speed of guided ground transportation continues to increase, the reaction : time as well as the sensory and information processing capacities of on- and off-board : operators remain constant. This report, the first of two examining criti...

Plasma Theory and Simulation.

DTIC Science & Technology

1986-06-30

energy are conserved, and the entropy of the plasma either in- creases or remains constant. Furthermore, the collision kinematics are relativistic...addresses within that array. c* Note that in PDW1 the suboutine MOVE must be renamed. imove = nloc(2) - nadd do 10 isp=nsp,2,-l moveto = nloc(isp) + 1

Human factors phase II: design and evaluation of decision aids for control of high-speed trains: experiments and model

DOT National Transportation Integrated Search

1996-12-01

Although the speed of some guided ground transportation systems continues to increase, the reaction time and the sensory : and information processing capacities of railroad personnel remain constant. This second report in a series examining : critica...

Male Psychopaths and Their Criminal Careers.

ERIC Educational Resources Information Center

Hare, Robert D.; And Others

1988-01-01

Examined criminal histories of male psychopaths and nonpsychopaths, exploring time in prison and conviction rates for five-year periods between ages of 16 and 45. Criminal activities of nonpsychopaths were relatively constant over years; activities of psychopaths remained high until around age 40, then declined dramatically. Results are consistent…

Application of new vaccine technology to improve immunity and productivity: advantages and challenges

USDA-ARS?s Scientific Manuscript database

Vaccines play a critical role in the poultry industry’s efforts to protect animals against disease. However, providing safe, efficacious, and cost-effective vaccines remains a constant concern to the industry. Recent advances in avian immunology, genetics, molecular biology, and pathogenesis have ...

Federal Power Grab.

ERIC Educational Resources Information Center

Hyde, Henry

1998-01-01

Constant attention by all Americans is needed to preserve what little local control in education remains. Chief among dangerous federal legislation moving the country toward a federal education system is the Goals 2000: Educate America Act. The paper examines Goals 2000 and other federal legislation that seeks to remove parental control, noting…

Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

PubMed

Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

2014-01-01

In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols.

The mechanics of running in children

PubMed Central

Schepens, B; Willems, P A; Cavagna, G A

1998-01-01

The effect of age and body size on the bouncing mechanism of running was studied in children aged 2-16 years.The natural frequency of the bouncing system (fs) and the external work required to move the centre of mass of the body were measured using a force platform.At all ages, during running below ≈11 km h−1, the freely chosen step frequency (f) is about equal to fs (symmetric rebound), independent of speed, although it decreases with age from 4 Hz at 2 years to 2.5 Hz above 12 years.The decrease of step frequency with age is associated with a decrease in the mass-specific vertical stiffness of the bouncing system (k/m) due to an increase of the body mass (m) with a constant stiffness (k). Above 12 years, k/m and f remain approximately constant due to a parallel increase in both k and m with age.Above the critical speed of ≈11 km h−1, independent of age, the rebound becomes asymmetric, i.e. f < fs.The maximum running speed (V¯f,max) increases with age while the step frequency at remains constant (≈4 Hz), independent of age.At a given speed, the higher step frequency in preteens results in a mass-specific power against gravity less than that in adults. The external power required to move the centre of mass of the body is correspondingly reduced. PMID:9596810

Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

PubMed

Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

2016-01-01

Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  < 0.05 considered as significant. Perfusate flow remained constant in the Constant flow group, but was more than halved during hypothermia in the Constant PPA group concomitant with a more fold increase in PVR. In the Constant flow group, Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased hemoconcentration, but the changes were less in hypothermic lungs perfused at constant PPA.

Tracking for underweight, overweight and obesity from childhood to adolescence: a 5-year follow-up study in urban Indonesian children.

PubMed

Julia, M; van Weissenbruch, M M; Prawirohartono, E P; Surjono, A; Delemarre-van de Waal, H A

2008-01-01

To assess tracking of body mass index (BMI) of urban Indonesian children from childhood to adolescence and to compare the prevalence of underweight, overweight and obesity in 6- to 8-year-old children from two surveys: years 1999 and 2004. A longitudinal study assessing BMI tracking of 308 urban children followed from age 6-8 to 11-13 years and two cross-sectional surveys comparing the prevalence of underweight, overweight and obesity in 6- to 8-year-old children: year 1999 (n = 1,524) and 2004 (n = 510). Childhood BMI determined 52.3% variation of later BMI. After 5.1 (0.6) years the prevalence of overweight and obesity increased from 4.2 and 1.9% in childhood to 8.8 and 3.2% in adolescence. The prevalence of underweight decreased from 27.3 to 18.8%. All obese children remained obese, 84.6% overweight children stayed overweight, 56.0% underweight children remained underweight. In cross-sectional comparison the prevalence of overweight and obesity raised from 5.3 to 8.6% and from 2.7 to 3.7%, respectively. The prevalence of underweight remained constant. The prevalence of overweight and obesity increases as children grow into adolescence. Overweight or obese children are more likely to remain overweight or obese. Cross-sectional comparison shows, while the prevalence of underweight stays constant, the prevalence of overweight and obesity increases. (c) 2008 S. Karger AG, Basel

When patients choose faith over medicine: physician perspectives on religiously related conflict in the medical encounter.

PubMed

Curlin, Farr A; Roach, Chad J; Gorawara-Bhat, Rita; Lantos, John D; Chin, Marshall H

2005-01-10

Patients at times disagree with medical recommendations for religious reasons. Despite a lively debate about how physicians should respond to patients' religious concerns, little is known about how physicians actually respond. We explored the ways in which physicians interpret and respond to conflict between medical recommendations and patients' religious commitments. One-to-one, in-depth, semistructured interviews with 21 physicians from a range of religious affiliations, specialties, and practice settings. Interviews were transcribed, coded, and analyzed for emergent themes through an iterative process of textual analysis informed by the principle of constant comparison. Conflict introduced by religion is common and occurs in 3 types of settings: (1) those in which religious doctrines directly conflict with medical recommendations, (2) those that involve an area in which there is extensive controversy within the broader society, and (3) settings of relative medical uncertainty in which patients "choose faith over medicine." In response to such conflict, physicians first seek to accommodate patients' ideas by remaining open-minded and flexible in their approach. However, if they believe patients' religiously informed decisions will cause them to suffer harm, physicians make efforts to persuade patients to follow medical recommendations. When religiously related conflict arises, physicians appear to intuitively navigate a tension between respecting patients' autonomy by remaining open-minded and flexible and seeking patients' good by persuading them to follow medical recommendations. In such contexts, religion and medicine are intertwined, and moral counsel inheres in physicians' medical recommendations.

Interactions between yeast lees and wine polyphenols during simulation of wine aging: I. Analysis of remnant polyphenolic compounds in the resulting wines.

PubMed

Mazauric, Jean-Paul; Salmon, Jean-Michel

2005-07-13

Wine aging on yeast lees is a traditional enological practice used during the manufacture of wines. This technique has increased in popularity in recent years for the aging of red wines. Although wine polyphenols interact with yeast lees to a limited extent, such interactions have a large effect on the reactivity toward oxygen of wine polyphenolic compounds and yeast lees. Various domains of the yeast cell wall are protected by wine polyphenols from the action of extracellular hydrolytic enzymatic activities. Polysaccharides released during autolysis are thought to exert a significant effect on the sensory qualities of wine. We studied the chemical composition of polyphenolic compounds remaining in solution or adsorbed on yeast lees after various contact times during the simulation of wine aging. The analysis of the remnant polyphenols in the wine indicated that wine polyphenols adsorption on yeast lees follows biphasic kinetics. An initial and rapid fixation is followed by a slow, constant, and saturating fixation that reaches its maximum after about 1 week. Only very few monomeric phenolic compounds remained adsorbed on yeast lees, and no preferential adsorption of low or high polymeric size tannins occurred. The remnant condensed tannins in the wine contained fewer epigallocatechin units than the initial tannins, indicating that polar condensed tannins were preferentially adsorbed on yeast lees. Conversely, the efficiency of anthocyanin adsorption on yeast lees was unrelated to its polarity.

Waters in Croatia between practice and needs: public health challenge.

PubMed

Vitale, Ksenija; Marijanović Rajcić, Marija; Senta, Ankica

2002-08-01

To describe waters monitoring in Croatia and legislation status for their evaluation, and to present health-relevant data and long-term analysis of the Drava river water, which is used in drinking water production. Survey of databanks of various Croatian institutions related to waters, and physical and chemical analysis of 13 surface water pollutants, applying HRN ISO laboratory methods. Since 1992 until 2000, water systems had 10% of contaminated samples, whereas local community and private water sources had 30% of such samples. Since 1981, 84 waterborne epidemics have been registered, affecting 7,581 people with predominantly gastrointestinal problems. The Drava river monitoring revealed that lead, cadmium, and mercury concentrations have constantly exceeded, whereas nickel and copper remained within allowed values for the Drava river to be classified into the second category of surface waters. Both nitrates and nitrites have been increasing with time, nitrates exceeding and nitrites remaining within guideline values. Total phosphorus and nitrogen concentrations also increased with time, still being below allowed maximum values. Chemical oxygen demand has been decreasing. Alkalinity has been satisfactory. Salt burden has been increasing. Both drinking water quality assessment and surface water monitoring in Croatia use less parameters then recommended by World Health Organization or signed conventions. The quality of Drava water has been improving, but still does not fully conform to the second category of surface water. More parameters should be used in its monitoring, as recommended by EU conventions and laws.

Is Science Built on the Shoulders of Women? A Study of Gender Differences in Contributorship.

PubMed

Macaluso, Benoit; Larivière, Vincent; Sugimoto, Thomas; Sugimoto, Cassidy R

2016-08-01

Women remain underrepresented in the production of scientific literature, and relatively little is known regarding the labor roles played by women in the production of knowledge. This study examined labor roles by gender using contributorship data from science and medical journals published by the Public Library of Science (PLOS), which require each author to indicate their contribution to one or more of the following tasks: (1) analyzed the data, (2) conceived and designed the experiments, (3) contributed reagents/materials/analysis tools, (4) performed the experiments, and (5) wrote the paper. The authors analyzed contribution data from more than 85,000 articles published between 2008 and 2013 in PLOS journals with respect to gender using both descriptive and regression analyses. Gender was a significant variable in determining the likelihood of performing a certain task associated with authorship. Women were significantly more likely to be associated with performing experiments, and men were more likely to be associated with all other authorship roles. This holds true controlling for academic age: Although experimentation was associated with academically younger scholars, the gap between male and female contribution to this task remained constant across academic age. Inequalities were observed in the distribution of scientific labor roles. These disparities have implications for the production of scholarly knowledge, the evaluation of scholars, and the ethical conduct of science. Adopting the practice of identifying contributorship rather than authorship in scientific journals will allow for greater transparency, accountability, and equitable allocation of resources.

Temperature metrology

NASA Astrophysics Data System (ADS)

Fischer, J.; Fellmuth, B.

2005-05-01

The majority of the processes used by the manufacturing industry depend upon the accurate measurement and control of temperature. Thermal metrology is also a key factor affecting the efficiency and environmental impact of many high-energy industrial processes, the development of innovative products and the health and safety of the general population. Applications range from the processing, storage and shipment of perishable foodstuffs and biological materials to the development of more efficient and less environmentally polluting combustion processes for steel-making. Accurate measurement and control of temperature is, for instance, also important in areas such as the characterization of new materials used in the automotive, aerospace and semiconductor industries. This paper reviews the current status of temperature metrology. It starts with the determination of thermodynamic temperatures required on principle because temperature is an intensive quantity. Methods to determine thermodynamic temperatures are reviewed in detail to introduce the underlying physical basis. As these methods cannot usually be applied for practical measurements the need for a practical temperature scale for day-to-day work is motivated. The International Temperature Scale of 1990 and the Provisional Low Temperature Scale PLTS-2000 are described as important parts of the International System of Units to support science and technology. Its main importance becomes obvious in connection with industrial development and international markets. Every country is strongly interested in unique measures, in order to guarantee quality, reproducibility and functionability of products. The eventual realization of an international system, however, is only possible within the well-functioning organization of metrological laboratories. In developed countries the government established scientific institutes have certain metrological duties, as, for instance, the maintenance and dissemination of national units. For the base unit kelvin, this procedure is described in the sections on practical temperature scales, practical thermometry and reference standards. Testing experimentally the fundamental laws of physics means in practice the precise determination of the fundamental constants appearing in the laws. The essence of current activities is that prototypes, which may vary uncontrollably with time and location, are replaced by abstract experimental prescriptions that relate the units to the constants. This approach is shown for the definition of the kelvin and the Boltzmann constant. Dedicated to the occasion of the 60th birthday of Wolfgang Buck.

Changes in quality and biochemical parameters in 'Idared' apples during prolonged shelf life and 1-MCP treatment.

PubMed

Bizjak, Jan; Slatnar, Ana; Stampar, Franci; Veberic, Robert

2012-12-01

In this study, changes in quality and various biochemical parameters of 'Idared' apples during prolonged shelf life period after ultra-low oxygen (ULO) storage were investigated. Additionally, the impact of the postharvest application of 1-methylcyclopropene (1-MCP) on different parameters was evaluated. After the harvest, apples were stored in the ULO storage for 6 months and then exposed to room temperature. Fruit firmness, peel color, and changes in sugars, organic acids and phenolics were monitored during the 3 weeks of shelf life. Malic acid, sugars and firmness decreased at room temperature. However, the color of the apples remained unchanged. The level of citric and ascorbic acid remained constant. Levels of phenolics in the peel increased significantly, whereas remained constant in the pulp of apples. 1-MCP treatment resulted in higher amounts of fructose and glucose, malic acid and greater firmness of apples. However, 1-MCP did not influence the phenolic content, ascorbic acid or color. The results obtained indicate that the content of different health-promoting compounds of apples does not change dramatically at room temperature. At the same time these results suggest that 1-MCP could be useful for maintaining certain quality and biochemical parameters and might extend the shelf life of apples.

Microwave dielectric measurements of erythrocyte suspensions.

PubMed Central

Bao, J Z; Davis, C C; Swicord, M L

1994-01-01

Complex dielectric constants of human erythrocyte suspensions over a frequency range from 45 MHz to 26.5 GHz and a temperature range from 5 to 40 degrees C have been determined with the open-ended coaxial probe technique using an automated vector network analyzer (HP 8510). The spectra show two separate major dispersions (beta and gamma) and a much smaller dispersion between them. The two major dispersions are analyzed with a dispersion equation containing two Cole-Cole functions by means of a complex nonlinear least squares technique. The parameters of the equation at different temperatures have been determined. The low frequency behavior of the spectra suggests that the dielectric constant of the cell membrane increases when the temperature is above 35 degrees C. The real part of the dielectric constant at approximately 3.4 GHz remains almost constant when the temperature changes. The dispersion shifts with temperature in the manner of a thermally activated process, and the thermal activation enthalpies for the beta- and gamma-dispersions are 9.87 +/- 0.42 kcal/mol and 4.80 +/- 0.06 kcal/mol, respectively. PMID:8075351

Effects of BOX engineering on analogue/RF and circuit performance of InGaAs-OI-Si MOSFET

NASA Astrophysics Data System (ADS)

Maity, Subir Kr.; Pandit, Soumya

2017-11-01

InGaAs is an attractive choice as alternate channel material in n-channel metal oxide semiconductor transistor for high-performance applications. However, electrostatic integrity of such device is poor. In this paper, we present a comprehensive technology computer-aided design simulation-based study of the effect of scaling the thickness of the buried oxide (BOX) region and varying the dielectric constant of BOX material on the electrostatic integrity, analogue/radio frequency (RF) performance and circuit performance of InGaAs-on-Insulator device. Device with thin BOX layer gives better drain-induced barrier lowering performance which enhances output resistance. The carrier mobility remains almost constant with thinning of BOX layer up to certain value. By lowering the dielectric constant of the BOX material, it is further possible to improve the analogue and RF performance. Effect of BOX thickness scaling and role of BOX dielectric material on gain-frequency response of common source amplifier is also studied. It is observed that frequency response of the amplifier improves for thin BOX and with low dielectric constant-based material.

Competition kinetics using the UV/H2O2 process: a structure reactivity correlation for the rate constants of hydroxyl radicals toward nitroaromatic compounds.

PubMed

García Einschlag, Fernando S; Carlos, Luciano; Capparelli, Alberto L

2003-10-01

The rate constants for hydroxyl radical reaction toward a set of nitroaromatic substrates kS, have been measured at 25 degrees C using competition experiments in the UV/H2O2 process. For a given pair of substrates S1 and S2, the relative reactivity beta (defined as kS1/kS2) was calculated from the slope of the corresponding double logarithmic plot, i.e., of ln[S1] vs. ln[S2]. This method is more accurate and remained linear for larger conversions in comparison with the plots of ln[S1] and ln[S2] against time. The rate constants measured ranged from 0.33 to 8.6 x 10(9) M(-1)s(-1). A quantitative structure-reactivity relationship was found using the Hammett equation. Assuming sigma values to be additive, a value of -0.60 was obtained for the reaction constant rho. This value agrees with the high reactivity and the electrophilic nature of HO* radical.

A critical review of current nursing faculty practice.

PubMed

Sawyer, M J; Alexander, I M; Gordon, L; Juszczak, L J; Gilliss, C

2000-12-01

To critically examine the current literature on nursing faculty practice, using the National Organization of Nurse Practitioner Faculties (NONPF) Guidelines for Evaluation of Faculty Practice, and to examine faculty practice models' strengths, weaknesses, and barriers. Thirty-five articles describing models of faculty practice were identified through an exhaustive search on CINAHL and Medline. Two NONPF monographs on nursing faculty practice were used as guidelines for the critical review. Faculty practice has become an integral component of faculty-role expectations at many schools of nursing. Workload, especially without adequate compensation, remains a hindrance to practice. The value of faculty practice time and expertise has not been sufficiently demonstrated. Integration of practitioner, educator and researcher roles remains extremely difficult and sometimes elusive. Faculty practice offers many advantages to schools of nursing, including educational and research opportunities for faculty and students, as well as practice sites and affordable community healthcare. Providing health care in the community presents an opportunity for independent and collaborative practice. To fully utilize the great research opportunities provided by faculty practice, more emphasis must be placed on gathering and analyzing descriptive data.

Accurate Measurements of the Dielectric Constant of Seawater at L Band

NASA Technical Reports Server (NTRS)

Lang, Roger; Zhou, Yiwen; Utku, Cuneyt; Le Vine, David

2016-01-01

This paper describes measurements of the dielectric constant of seawater at a frequency of 1.413 GHz, the center of the protected band (i.e., passive use only) used in the measurement of sea surface salinity from space. The objective of the measurements is to accurately determine the complex dielectric constant of seawater as a function of salinity and temperature. A resonant cylindrical microwave cavity in transmission mode has been employed to make the measurements. The measurements are made using standard seawater at salinities of 30, 33, 35, and 38 practical salinity units over a range of temperatures from 0 degree C to 35 degree C in 5 degree C intervals. Repeated measurements have been made at each temperature and salinity. Mean values and standard deviations are then computed. The total error budget indicates that the real and imaginary parts of the dielectric constant have a combined standard uncertainty of about 0.3 over the range of salinities and temperatures considered. The measurements are compared with the dielectric constants obtained from the model functions of Klein and Swift and those of Meissner and Wentz. The biggest differences occur at low and high temperatures.

Silver (Ag)-Graphene oxide (GO) - Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanostructured composites with high dielectric constant and low dielectric loss

NASA Astrophysics Data System (ADS)

Moharana, Srikanta; Mahaling, Ram Naresh

2017-07-01

The Silver (Ag)-Graphene oxide (GO)-Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composites were prepared by solution casting techniques and their dielectric properties were measured. Field emission scanning electron microscopy (FESEM) and X-ray analysis (XRD) confirmed that Ag layers were formed on the surface of the Graphene oxide sheets and homogeneously dispersed into the PVDF-HFP matrix. The result showed that the incorporation of Ag-GO nanoparticles greatly improved the dielectric constant value nearly about 65 at 100 Hz, which is comparatively much higher than that of pure PVDF-HFP. Furthermore, the dielectric loss of the composite remained at a low level (<0.1 at 100 Hz). A percolation threshold of 1.5 vol% of Ag-GO was calculated and explained accordingly. The composite having high dielectric constant and low dielectric loss might be used as dielectric materials for electronic capacitors.

Arthroscopic fixation of acute acromioclavicular joint disruption with TightRope™: Outcome and complications after minimum 2 (2-5) years follow-up.

PubMed

Zhang, Li-Feng; Yin, Bo; Hou, Su; Han, Bing; Huang, De-Fa

2017-01-01

To evaluate the midterm results of arthroscopic reconstruction of acute acromioclavicular (AC) joint disruption using TightRope™ system. We retrospectively assess the results of 24 patients of acute AC joint dislocation who were operated using TightRope system. Constant and University of California, Los Angeles (UCLA) scores and coracoclavicular distance were calculated pre- and postoperatively. Data was entered into MS excel and analyzed using the SPSS version 17. The mean follow-up was 39.45 months. Constant and UCLA scores were significantly increased postoperatively. Six patients had partial loss of reduction within 3-6 months and two patients had a failure of construct. Constant score was significantly lower in these patients. TightRope reconstruction of the AC joint is a reproducible and safe alternative to many other techniques of AC joint reconstruction. Early subluxation remains a concern and may reflect the need for technique modification.

Effects of constant immigration on the dynamics and persistence of stable and unstable Drosophila populations

PubMed Central

Dey, Snigdhadip; Joshi, Amitabh

2013-01-01

Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively stable populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of stable versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546

Procedural Portfolio Planning in Plastic Surgery, Part 1: Strategic Changes in Clinical Practice to Increase Physician Revenue, Improve Operative Throughput, and Maintain Patient Satisfaction.

PubMed

Hultman, Charles Scott

2016-06-01

Portfolio planning in health care represents the strategic prioritization of services that permits an organization to better achieve its goals of margin and mission. Because of recent volatility in the economy, declining reimbursement, and rising costs of providing care, such strategic planning has become increasingly important if physicians want to remain leaders in health care. This project assesses the financial impact of procedural portfolio planning on an academic plastic surgery practice from the physician's perspective. We tracked the top 50 procedures, defined as total charges per CPT code, that were performed in our baseline year, for 6 providers in a stable plastic surgery practice. At the end of the first year, we implemented 3 types of strategic changes: growth of areas with high contribution margin (laser resurfacing of burn scars), curtailment of high-risk procedures with negative contribution margin (panniculectomy in smokers), and improved efficiency of mission-critical services with high resource consumption (free-flap breast reconstruction). During the 2-year study period, we had no turnover in faculty, did not pursue any formal marketing, did not change our surgical fees or billing system, provided care independent of payer mix, and maintained our commitment to indigent care. Outcome measures included procedural charges and revenue, collection rates, work relative value units, operating room times, idle times (room time less case time), receipts/minute in operating room, uncompensated charity care, and patient satisfaction (Press-Gainey scores). Before the study period, annual incremental growth in our practice was 1% to 2%, in terms of charges and receipts. After implementation of the portfolio planning project, the financial position of our division improved significantly, with patient satisfaction rates increasing from 85.5% to 94.1% and charity care remaining constant at US $400,000 per year. Encounters, work relative value units, charges, and receipts all increased by 16% to 27%, with receipts/minute increasing from US $5.60 per minute to US $7.28 per minute. Interestingly, but not surprisingly, highest margin cases did not correspond with highest volume or highest revenue cases; portfolio analysis helped us to align these parameters, without sacrificing patient satisfaction or commitment to indigent care. The highest receipt/minute procedure was laser ablation of vascular lesions (US $23.87), whereas one of the lowest receipt/minute cases was muscle free flap (US $3.07). Procedural portfolio analysis is a powerful tool that can guide strategy and positively impact the financial position and clinical value of the services provided by an academic plastic surgery practice. Identifying high margin procedures allows the surgeon to focus marketing efforts, target areas of future growth, and optimize the blend of margin and mission.

The Development of Ambiguous Figure Perception

ERIC Educational Resources Information Center

Wimmer, Marina C.; Doherty, Martin J.

2011-01-01

Ambiguous figures have fascinated researchers for almost 200 years. The physical properties of these figures remain constant, yet two distinct interpretations are possible; these reverse (switch) from one percept to the other. The consensus is that reversal requires complex interaction of perceptual bottom-up and cognitive top-down elements. The…

Adapting to Changing Memory Retrieval Demands: Evidence from Event-Related Potentials

ERIC Educational Resources Information Center

Benoit, Roland G.; Werkle-Bergner, Markus; Mecklinger, Axel; Kray, Jutta

2009-01-01

This study investigated preparatory processes involved in adapting to changing episodic memory retrieval demands. Event-related potentials (ERPs) were recorded while participants performed a general old/new recognition task and a specific task that also required retrieval of perceptual details. The relevant task remained either constant or changed…

Anatomy Drawing Screencasts: Enabling Flexible Learning for Medical Students

ERIC Educational Resources Information Center

Pickering, James D.

2015-01-01

The traditional lecture remains an essential method of disseminating information to medical students. However, due to the constant development of the modern medical curriculum many institutions are embracing novel means for delivering the core anatomy syllabus. Using mobile media devices is one such way, enabling students to access core material…

Vocational Rehabilitation in Substance Abuse Treatment Programs

ERIC Educational Resources Information Center

Machlan, Bonna; Brostrand, H. L.; Benshoff, John J.

2004-01-01

Research indicates that those who undergo treatment for alcohol and other drug abuse largely have poor work histories and low employment rates, regardless of their education. Relapse rates for individuals in recovery increase when unemployment remains a constant in their lives. Consequently, providing vocational services during treatment may be a…

Alumni Perspectives Survey, 2011. Survey Report

ERIC Educational Resources Information Center

Sheikh, Sabeen

2011-01-01

Since the Graduate Management Admission Council[R] (GMAC[R]) first began conducting its Alumni Perspectives Surveys 11 years ago, several "truths" about graduate business school alumni have consistently stood the test of time: They are and remain eminently employable. They constantly rate the value of the degree highly. This year's results are…

10 CFR 63.305 - Required characteristics of the reference biosphere.

Code of Federal Regulations, 2011 CFR

2011-01-01

....305 Section 63.305 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE... biosphere (other than climate), human biology, or increases or decreases of human knowledge or technology... factors remain constant as they are at the time of submission of the license application. (c) DOE must...

Laplace Boundary-Value Problem in Paraboloidal Coordinates

ERIC Educational Resources Information Center

Duggen, L.; Willatzen, M.; Voon, L. C. Lew Yan

2012-01-01

This paper illustrates both a problem in mathematical physics, whereby the method of separation of variables, while applicable, leads to three ordinary differential equations that remain fully coupled via two separation constants and a five-term recurrence relation for series solutions, and an exactly solvable problem in electrostatics, as a…

Teaching Strategies Used to Maintain Classroom Order

ERIC Educational Resources Information Center

Roman, Daniel

2007-01-01

With the ever evolving environment of the classroom setting the role of the teacher is constantly being challenged and the responsibilities remain the same. Teachers are required to create a safe learning environment for student learning. Although this is an overwhelming responsibility it is not impossible. This study explored teachers'…

School Roofing Asset Management

ERIC Educational Resources Information Center

McNeil, Dennis

2011-01-01

Maintenance of physical structures always has been a significant challenge for education institutions, but today's economic climate, which has cut budgets to the bone, has raised the stakes. Funding, staffing and resources for proper maintenance are becoming harder to find, and the need for upkeep and maintenance remains constant. Nowhere is this…

A Career Stage Analysis of Career and Organizational Commitment in Nursing.

ERIC Educational Resources Information Center

Reilly, Nora P.; Orsak, Charles L.

1991-01-01

From a sample of 1,520 hospital nurses, 520 responses demonstrated that (1) affective measures were strongly associated with career and affective-organizational commitment and (2) reports of continuance commitment and normative commitment increased significantly with career stage, but career commitment remained constant. (Author/SK)

If You're So Smart, Why Aren't You Rich?

ERIC Educational Resources Information Center

Woloshin, Phyllis

1986-01-01

Argues that salary differentials among community college faculty are unrealistic and based on the inaccurate assumptions that people are motivated primarily by money; that high-demand disciplines will remain constant over time; that attitudes toward other disciplines and faculty members are unaffected by salary differentials; and that teaching is…

Solutions to Black Male Prison Crisis: Elusive and Difficult.

ERIC Educational Resources Information Center

Wiley, Ed, III, Conciatore, Jacqueline

1989-01-01

Although the proportion of Black men in prison has remained constant over the last 15 years, their numbers have increased dramatically. Since efforts to educate and rehabilitate prisoners are largely ineffective, Black boys must be educated and socialized early in their lives so they won't commit crimes. (WS)

Overview of USEPA's ORD Technical Outreach and Support Activities on Vapor Intrusion Impacts - 03/2008

EPA Science Inventory

The science of determining, characterizing and managing vapor intrusion risks is constantly evolving. Much remains to be done in assisting regulators, consultants and other decision-makers to make informed decisions in mitigating the problem and reducing these risks. ORD has been...

System Lifetimes, The Memoryless Property, Euler's Constant, and Pi

ERIC Educational Resources Information Center

Agarwal, Anurag; Marengo, James E.; Romero, Likin Simon

2013-01-01

A "k"-out-of-"n" system functions as long as at least "k" of its "n" components remain operational. Assuming that component failure times are independent and identically distributed exponential random variables, we find the distribution of system failure time. After some examples, we find the limiting…

A Legal Constant

ERIC Educational Resources Information Center

Taylor, Kelley R.

2009-01-01

The 21st century has brought many technological, social, and economic changes--nearly all of which have affected schools and the students, administrators, and faculty members who are in them. Luckily, as some things change, other things remain the same. Such is true with the fundamental legal principles that guide school administrators' actions…

Public attitudes about financing municipal recreation

Treesearch

Rodney R. Zwick; Thomas A. More; Tad Nunez

2008-01-01

Communities constantly seek creative financing for public services like recreation. Property tax remains central for financing, but user fees, grants, sales taxes, sponsorship, and bond issues have increased. This paper examines preferences for alternative funding mechanisms in a survey of Hartford, VT residents. Public support for municipal facilities and programs...

Comparing modeled productivity to historical data in New England potato production systems

USDA-ARS?s Scientific Manuscript database

Potato yields in Northern Maine have remained fairly constant for the last 70 years. Many long-term projects have sought to identify the limitations to potato yield, but identifying limiting factors is difficult without first identifying the upper limits of potato production. A simple, light-driven ...

[Characteristics of autonomic status in employees working with computers].

PubMed

Vlasova, E M; Zaĭtseva, N V; Maliutina, N N

2011-01-01

Human evolution is accompanied by "sensible thoughts" spread to all spheres of occupational activities. One can hardly find an industrial enterprise without computers. In contemporary industry, health care in conditions of humans and computers interaction and evaluation of harm in computer users remain topical. Social and occupational environment is not always comfortable for human body. Changes is occupational conditions, with wide use of computer technologies, decrease role of manual labour and increase role of intellectual work from the one hand, but from the other hand, chasing economic profit alters individual "comfort zone" due to constant psychoemotional stress and causes "burnout". Being healthy in constant stress is impossible.

A Quantitative Test of the Applicability of Independent Scattering to High Albedo Planetary Regoliths

NASA Technical Reports Server (NTRS)

Goguen, Jay D.

1993-01-01

To test the hypothesis that the independent scattering calculation widely used to model radiative transfer in atmospheres and clouds will give a useful approximation to the intensity and linear polarization of visible light scattered from an optically thick surface of transparent particles, laboratory measurements are compared to the independent scattering calculation for a surface of spherical particles with known optical constants and size distribution. Because the shape, size distribution, and optical constants of the particles are known, the independent scattering calculation is completely determined and the only remaining unknown is the net effect of the close packing of the particles in the laboratory sample surface...

The broad applicability of the disk laser principle: from CW to ps

NASA Astrophysics Data System (ADS)

Killi, Alexander; Stolzenburg, Christian; Zawischa, Ivo; Sutter, Dirk; Kleinbauer, Jochen; Schad, Sven; Brockmann, Rüdiger; Weiler, Sascha; Neuhaus, Jörg; Kalfhues, Steffen; Mehner, Eva; Bauer, Dominik; Schlueter, Holger; Schmitz, Christian

2009-02-01

The quasi two-dimensional geometry of the disk laser results in conceptional advantages over other geometries. Fundamentally, the thin disk laser allows true power scaling by increasing the pump spot diameter on the disk while keeping the power density constant. This scaling procedure keeps optical peak intensity, temperature, stress profile, and optical path differences in the disk nearly unchanged. The required pump beam brightness - a main cost driver of DPSSL systems - also remains constant. We present these fundamental concepts and present results in the wide range of multi kW-class CW-sources, high power Q-switched sources and ultrashort pulsed sources.

Rate constants for chemical reactions in high-temperature nonequilibrium air

NASA Technical Reports Server (NTRS)

Jaffe, R. L.

1986-01-01

In the nonequilibrium atmospheric chemistry regime that will be encountered by the proposed Aeroassisted Orbital Transfer Vehicle in the upper atmosphere, where air density is too low for thermal and chemical equilibrium to be maintained, the detailed high temperature air chemistry plays a critical role in defining radiative and convective heating loads. Although vibrational and electronic temperatures remain low (less than 15,000 K), rotational and translational temperatures may reach 50,000 K. Attention is presently given to the effects of multiple temperatures on the magnitudes of various chemical reaction rate constants, for the cases of both bimolecular exchange reactions and collisional excitation and dissociation reactions.

[Euthanasia and/or medically assisted suicide: Reflection on the new responsibility of the hospital pharmacist].

PubMed

Boissinot, L; Benamou, M; Léglise, P; Mancret, R-C; Huchon-Bécel, D

2014-03-01

Concern about euthanasia and medically assisted suicide is currently growing around the world and particularly in France. Though not authorized at present in France, the role of hospital pharmacist in this issue needs to be discussed. This article aims to gather medical and legal literature of European Union member states on these issues and particularly in France. To propose a practical thinking on the possible role of hospital pharmacist. Among European Union, euthanasia and/or assisted suicide have already been introduced in some member states' laws. In France, Leonetti law currently sets the legal framework for the management of end of life. To address the society's demand on these issues, French President F. Hollande made two ethics committees responsible for working on it. Both were mainly against euthanasia and assisted suicide. Though a bit forgotten in this debate, hospital pharmacist needs to be associated in the thinking, as the main "drug-keeper". Indeed, guidelines are necessary to outline and ensure a safe drug use, complying with professional ethics, if lethal doses are voluntarily prescribed. Pharmaceutical work is in constant evolution and is addressing new issues still unanswered, including assisted suicide and euthanasia. French pharmaceutical authorities should seize upon them, in order to guarantee pharmaceutical ethics. These practices, if authorized by law, should remain exceptional, and law strictly enforced. The pharmacist could be one of these "lawkeepers". Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Why do commercial CT scanners still employ traditional, filtered back-projection for image reconstruction?

PubMed Central

Pan, Xiaochuan; Sidky, Emil Y; Vannier, Michael

2010-01-01

Despite major advances in x-ray sources, detector arrays, gantry mechanical design and especially computer performance, one component of computed tomography (CT) scanners has remained virtually constant for the past 25 years—the reconstruction algorithm. Fundamental advances have been made in the solution of inverse problems, especially tomographic reconstruction, but these works have not been translated into clinical and related practice. The reasons are not obvious and seldom discussed. This review seeks to examine the reasons for this discrepancy and provides recommendations on how it can be resolved. We take the example of field of compressive sensing (CS), summarizing this new area of research from the eyes of practical medical physicists and explaining the disconnection between theoretical and application-oriented research. Using a few issues specific to CT, which engineers have addressed in very specific ways, we try to distill the mathematical problem underlying each of these issues with the hope of demonstrating that there are interesting mathematical problems of general importance that can result from in depth analysis of specific issues. We then sketch some unconventional CT-imaging designs that have the potential to impact on CT applications, if the link between applied mathematicians and engineers/physicists were stronger. Finally, we close with some observations on how the link could be strengthened. There is, we believe, an important opportunity to rapidly improve the performance of CT and related tomographic imaging techniques by addressing these issues. PMID:20376330

Value-added care: a paradigm shift in patient care delivery.

PubMed

Upenieks, Valda V; Akhavan, Jaleh; Kotlerman, Jenny

2008-01-01

Spiraling costs in health care have placed hospitals in a constant state of transition. As a result, nursing practice is now influenced by numerous factors and has remained in a continuous state of flux. Multiple changes within the last 2 decades in nurse/patient ratio and blend of front-line nurses are examples of this transition. To reframe the nursing practice into an economic equation that captures the cost, quality, and service, a paradigm shift in thinking is needed in order to assess work redesign. Nursing productivity must be evaluated in terms of value-added care, a vision that goes beyond direct care activities and includes team collaboration, physician rounding, increased RN-to-aide communication, and patient centeredness; all of which are crucial to the nurse's role and the patient's well-being. The science of appropriating staffing depends on assessment and implementation of systematic changes best illustrated through a "systems theory" framework. A throughput transformation is required to create process changes with input elements (number of front-line nurses) in order to increase time spent in value-added care and to decrease waste activities with an improvement in efficiency, quality, and service. The purpose of this pilot study was two-fold: (a) to gain an understanding of how much time RNs spent in value-added care, and (b) whether increasing the combined level of RNs and unlicensed assistive personnel increased the amount of time spent in value-added care compared to time spent in necessary tasks and waste.

TOPICAL REVIEW: Why do commercial CT scanners still employ traditional, filtered back-projection for image reconstruction?

NASA Astrophysics Data System (ADS)

Pan, Xiaochuan; Sidky, Emil Y.; Vannier, Michael

2009-12-01

Despite major advances in x-ray sources, detector arrays, gantry mechanical design and especially computer performance, one component of computed tomography (CT) scanners has remained virtually constant for the past 25 years—the reconstruction algorithm. Fundamental advances have been made in the solution of inverse problems, especially tomographic reconstruction, but these works have not been translated into clinical and related practice. The reasons are not obvious and seldom discussed. This review seeks to examine the reasons for this discrepancy and provides recommendations on how it can be resolved. We take the example of field of compressive sensing (CS), summarizing this new area of research from the eyes of practical medical physicists and explaining the disconnection between theoretical and application-oriented research. Using a few issues specific to CT, which engineers have addressed in very specific ways, we try to distill the mathematical problem underlying each of these issues with the hope of demonstrating that there are interesting mathematical problems of general importance that can result from in depth analysis of specific issues. We then sketch some unconventional CT-imaging designs that have the potential to impact on CT applications, if the link between applied mathematicians and engineers/physicists were stronger. Finally, we close with some observations on how the link could be strengthened. There is, we believe, an important opportunity to rapidly improve the performance of CT and related tomographic imaging techniques by addressing these issues.

Pharmaceutical Company Influence on Non-Steroidal Anti-inflammatory Drug Prescribing Behaviors

PubMed Central

Naik, Aanand D.; Woofter, Aaron L.; Skinner, Jessica M.; Abraham, Neena S.

2010-01-01

Objectives Adherence to safer nonsteroidal anti-inflammatory drug (NSAID) prescribing strategies remains low, despite their acceptance as markers of high-quality care and their aggressive dissemination. This study describes the taxonomy of methods used by pharmaceutical companies to influence physicians’ NSAID prescribing behaviors and elicits physicians’ perceptions of and counter-balances to these influences. Study Design In-depth interviews analyzed using the constant comparative method of qualitative data analysis. Methods Qualitative interviews were conducted with physicians representing various clinical specialties. Interviews were transcribed and coded inductively using grounded theory. Recruitment was stopped at 25 participants after the attainment of thematic saturation, when no new concepts emerged from ongoing analysis of consecutive interviews. Results Physicians described a variety of influences that shaped their NSAID prescribing behaviors, including detailing and direct contact with pharmaceutical representatives, requests from patients inspired by direct-to-consumer advertisements, and marketing during medical school and residency training. Physicians described practice guidelines, peer-reviewed evidence and opinions of local physician experts as important counterweights to pharmaceutical company influence. Local physician experts interpreted and provided context for new clinical evidence, practice guidelines and NSAID related marketing. Conclusions The social and communicative strategies used by pharmaceutical companies can be adapted to improve physicians’ adoption of guidelines for safer NSAID prescribing. The communicative interactions between local experts and other physicians who prescribe NSAIDs may be the critical target for future interventions to promote safer NSAID prescribing. PMID:19341315

Vitamin D dose response is underestimated by Endocrine Society's Clinical Practice Guideline.

PubMed

McKenna, Malachi J; Murray, Barbara F

2013-06-01

The recommended daily intakes of vitamin D according to the recent Clinical Practice Guideline (CPG) of the Endocrine Society are three- to fivefold higher than the Institute of Medicine (IOM) report. We speculated that these differences could be explained by different mathematical approaches to the vitamin D dose response. Studies were selected if the daily dose was ≤2000 IU/day, the duration exceeded 3 months, and 25-hydroxyvitamin D (25OHD) concentrations were measured at baseline and post-therapy. The rate constant was estimated according to the CPG approach. The achieved 25OHD result was estimated according to the following: i) the regression equation approach of the IOM; ii) the regression approach of the Vitamin D Supplementation in Older Subjects (ViDOS) study; and iii) the CPG approach using a rate constant of 2.5 (CPG2.5) and a rate constant of 5.0 (CPG5.0). The difference between the expected and the observed 25OHD result was expressed as a percentage of observed and analyzed for significance against a value of 0% for the four groups. Forty-one studies were analyzed. The mean (95% CI) rate constant was 5.3 (4.4-6.2) nmol/l per 100 IU per day, on average twofold higher than the CPG rate constant. The mean (95% CI) for the difference between the expected and observed expressed as a percentage of observed was as follows: i) IOM, -7 (-16,+2)% (t=1.64, P=0.110); ii) ViDOS, +2 (-8,+12)% (t=0.40, P=0.69); iii) CPG2.5, -21 (-27,-15)% (t=7.2, P<0.0001); and iv) CPG5.0+3 (-4,+10)% (t=0.91, P=0.366). The CPG 'rule of thumb' should be doubled to 5.0 nmol/l (2.0 ng/ml) per 100 IU per day, adopting a more risk-averse position.

Market segmentation and service: a strategy for success.

PubMed

Marchack, B W

1995-03-01

Current trends for health care reform and increasing emphasis on managed care threaten to erode the base of patients of many practices. A constant flow of new patients is critical to the success of a dental practice. This article discusses the nature of business markets and similarities between industries and their correlation to the delivery of prosthodontic services. The purpose of this article is to offer a strategy for increasing new patient flow without the use of advertising.

Teachers' Perceptions of Instructional Practices for Yup'ik Students with Special Education Needs: A Case Study

ERIC Educational Resources Information Center

Jacobson, Elisabeth

2017-01-01

As classrooms across America become more increasingly diverse, culturally and linguistically and students with special needs, the achievement gap remains evident. One population that remains behind their Caucasian peers is that of Alaska Natives. While many instructional practices have been identified for addressing the gap for many populations,…

Coupling time constants of striated and copper-plated coated conductors and the potential of striation to reduce shielding-current-induced fields in pancake coils

NASA Astrophysics Data System (ADS)

Amemiya, Naoyuki; Tominaga, Naoki; Toyomoto, Ryuki; Nishimoto, Takuma; Sogabe, Yusuke; Yamano, Satoshi; Sakamoto, Hisaki

2018-07-01

The shielding-current-induced field is a serious concern for the applications of coated conductors to magnets. The striation of the coated conductor is one of the countermeasures, but it is effective only after the decay of the coupling current, which is characterised with the coupling time constant. In a non-twisted striated coated conductor, the coupling time constant is determined primarily by its length and the transverse resistance between superconductor filaments, because the coupling current could flow along its entire length. We measured and numerically calculated the frequency dependences of magnetisation losses in striated and copper-plated coated conductors with various lengths and their stacks at 77 K and determined their coupling time constants. Stacked conductors simulate the turns of a conductor wound into a pancake coil. Coupling time constants are proportional to the square of the conductor length. Stacking striated coated conductors increases the coupling time constants because the coupling currents in stacked conductors are coupled to one another magnetically to increase the mutual inductances for the coupling current paths. We carried out the numerical electromagnetic field analysis of conductors wound into pancake coils and determined their coupling time constants. They can be explained by the length dependence and mutual coupling effect observed in stacked straight conductors. Even in pancake coils with practical numbers of turns, i.e. conductor lengths, the striation is effective to reduce the shielding-current-induced fields for some dc applications.

From Blank Canvas to Masterwork: Creating a Professional Practice Model at a Magnet Hospital

PubMed Central

Tydings, Donna M.; Nickoley, Sue; Nichols, Lynn W.; Krenzer, Maureen E.

2016-01-01

Objective. The purpose of this study was to engage registered nurses (RNs) in the creation of a Professional Practice Model (PPM). Background. PPMs are essential as the philosophical underpinnings for nursing practice. The study institution created a new PPM utilizing the voice of their RNs. Methods. Qualitative inquiry with focus groups was conducted to explore RNs values and beliefs about their professional practice. Constant-comparative analysis was used to code data and identify domains. Results. The 92 RN participants represented diverse roles and practice settings. The four domains identified were caring, knowing, navigating, and leading. Conclusions. Nurse leaders face the challenge of assisting nurses in articulating their practice using a common voice. In this study, nurses described their identity, their roles, and how they envisioned nursing should be practiced. The results align with the ANCC Magnet® Model, ANA standards, and important foundational and organization specific documents. PMID:28097022

Chloroplast genes are expressed during intracellular symbiotic association of Vaucheria litorea plastids with the sea slug Elysia chlorotica.

PubMed

Mujer, C V; Andrews, D L; Manhart, J R; Pierce, S K; Rumpho, M E

1996-10-29

The marine slug Elysia chlorotica (Gould) forms an intracellular symbiosis with photosynthetically active chloroplasts from the chromophytic alga Vaucheria litorea (C. Agardh). This symbiotic association was characterized over a period of 8 months during which E. chlorotica was deprived of V. litorea but provided with light and CO2. The fine structure of the symbiotic chloroplasts remained intact in E. chlorotica even after 8 months of starvation as revealed by electron microscopy. Southern blot analysis of total DNA from E. chlorotica indicated that algal genes, i.e., rbcL, rbcS, psaB, psbA, and 16S rRNA are present in the animal. These genes are typically localized to the plastid genome in higher plants and algae except rbcS, which is nuclear-encoded in higher plants and green (chlorophyll a/b) algae. Our analysis suggests, however, that similar to the few other chromophytes (chlorophyll a/c) examined, rbcS is chloroplast encoded in V. litorea. Levels of psbA transcripts remained constant in E. chlorotica starved for 2 and 3 months and then gradually declined over the next 5 months corresponding with senescence of the animal in culture and in nature. The RNA synthesis inhibitor 6-methylpurine reduced the accumulation of psbA transcripts confirming active transcription. In contrast to psbA, levels of 16S rRNA transcripts remained constant throughout the starvation period. The levels of the photosystem II proteins, D1 and CP43, were high at 2 and 4 months of starvation and remained constant at a lower steady-state level after 6 months. In contrast, D2 protein levels, although high at 2 and 4 months, were very low at all other periods of starvation. At 8 months, de novo synthesis of several thylakoid membrane-enriched proteins, including D1, still occurred. To our knowledge, these results represent the first molecular evidence for active transcription and translation of algal chloroplast genes in an animal host and are discussed in relation to the endosymbiotic theory of eukaryote origins.

Chloroplast genes are expressed during intracellular symbiotic association of Vaucheria litorea plastids with the sea slug Elysia chlorotica.

PubMed Central

Mujer, C V; Andrews, D L; Manhart, J R; Pierce, S K; Rumpho, M E

1996-01-01

The marine slug Elysia chlorotica (Gould) forms an intracellular symbiosis with photosynthetically active chloroplasts from the chromophytic alga Vaucheria litorea (C. Agardh). This symbiotic association was characterized over a period of 8 months during which E. chlorotica was deprived of V. litorea but provided with light and CO2. The fine structure of the symbiotic chloroplasts remained intact in E. chlorotica even after 8 months of starvation as revealed by electron microscopy. Southern blot analysis of total DNA from E. chlorotica indicated that algal genes, i.e., rbcL, rbcS, psaB, psbA, and 16S rRNA are present in the animal. These genes are typically localized to the plastid genome in higher plants and algae except rbcS, which is nuclear-encoded in higher plants and green (chlorophyll a/b) algae. Our analysis suggests, however, that similar to the few other chromophytes (chlorophyll a/c) examined, rbcS is chloroplast encoded in V. litorea. Levels of psbA transcripts remained constant in E. chlorotica starved for 2 and 3 months and then gradually declined over the next 5 months corresponding with senescence of the animal in culture and in nature. The RNA synthesis inhibitor 6-methylpurine reduced the accumulation of psbA transcripts confirming active transcription. In contrast to psbA, levels of 16S rRNA transcripts remained constant throughout the starvation period. The levels of the photosystem II proteins, D1 and CP43, were high at 2 and 4 months of starvation and remained constant at a lower steady-state level after 6 months. In contrast, D2 protein levels, although high at 2 and 4 months, were very low at all other periods of starvation. At 8 months, de novo synthesis of several thylakoid membrane-enriched proteins, including D1, still occurred. To our knowledge, these results represent the first molecular evidence for active transcription and translation of algal chloroplast genes in an animal host and are discussed in relation to the endosymbiotic theory of eukaryote origins. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:8901581

Choice with frequently changing food rates and food ratios.

PubMed

Baum, William M; Davison, Michael

2014-03-01

In studies of operant choice, when one schedule of a concurrent pair is varied while the other is held constant, the constancy of the constant schedule may exert discriminative control over performance. In our earlier experiments, schedules varied reciprocally across components within sessions, so that while food ratio varied food rate remained constant. In the present experiment, we held one variable-interval (VI) schedule constant while varying the concurrent VI schedule within sessions. We studied five conditions, each with a different constant left VI schedule. On the right key, seven different VI schedules were presented in seven different unsignaled components. We analyzed performances at several different time scales. At the longest time scale, across conditions, behavior ratios varied with food ratios as would be expected from the generalized matching law. At shorter time scales, effects due to holding the left VI constant became more and more apparent, the shorter the time scale. In choice relations across components, preference for the left key leveled off as the right key became leaner. Interfood choice approximated strict matching for the varied right key, whereas interfood choice hardly varied at all for the constant left key. At the shortest time scale, visit patterns differed for the left and right keys. Much evidence indicated the development of a fix-and-sample pattern. In sum, the procedural difference made a large difference to performance, except for choice at the longest time scale and the fix-and-sample pattern at the shortest time scale. © Society for the Experimental Analysis of Behavior.

Calculation of Airplane Performances Without the Aid of Polar Diagrams

NASA Technical Reports Server (NTRS)

Schrenk, Martin

1928-01-01

For good profiles the profile-drag coefficient is almost constant in the whole range which comes into consideration for practical flight. This is manifest in the consideration of the Gottingen airfoil tests and is confirmed by the investigations of the writer (measurements of the profile drag during flight by the Betz method), concerning which a detailed report will soon be published. The following deductions proceed from this fact. The formulas developed on the assumptions of a constant profile-drag coefficient afford an extensive insight into the influences exerted on flight performances by the structure of the airplane.

Building Digital Libraries: Running to Stand Still?

ERIC Educational Resources Information Center

Huwe, Terence K.

2005-01-01

Technostress--the challenge of keeping up with changing technology--has been one of the few constants in professional lives for the past 30 or more years. In this paper, the author addresses what constitutes "best practices" for keeping up with rapidly changing technology.

Study of an orbiting tethered dumbbell system having positive orbital energy

NASA Technical Reports Server (NTRS)

Arnold, David A.

1988-01-01

For very long tethered systems the sum of the kinetic and potential energy can be positive. The system remains in a circular orbit as long as the masses remain vertically aligned. The system is unstable without constant control of the alignment. If the upper mass rotates forward in the direction of the orbital motion, the system escapes out of orbit. If the upper mass rotates backward, the system falls out of orbit and the lower mass impacts the body around which the system is orbiting.

The structure of binding curves and practical identifiability of equilibrium ligand-binding parameters

PubMed Central

Middendorf, Thomas R.

2017-01-01

A critical but often overlooked question in the study of ligands binding to proteins is whether the parameters obtained from analyzing binding data are practically identifiable (PI), i.e., whether the estimates obtained from fitting models to noisy data are accurate and unique. Here we report a general approach to assess and understand binding parameter identifiability, which provides a toolkit to assist experimentalists in the design of binding studies and in the analysis of binding data. The partial fraction (PF) expansion technique is used to decompose binding curves for proteins with n ligand-binding sites exactly and uniquely into n components, each of which has the form of a one-site binding curve. The association constants of the PF component curves, being the roots of an n-th order polynomial, may be real or complex. We demonstrate a fundamental connection between binding parameter identifiability and the nature of these one-site association constants: all binding parameters are identifiable if the constants are all real and distinct; otherwise, at least some of the parameters are not identifiable. The theory is used to construct identifiability maps from which the practical identifiability of binding parameters for any two-, three-, or four-site binding curve can be assessed. Instructions for extending the method to generate identifiability maps for proteins with more than four binding sites are also given. Further analysis of the identifiability maps leads to the simple rule that the maximum number of structurally identifiable binding parameters (shown in the previous paper to be equal to n) will also be PI only if the binding curve line shape contains n resolved components. PMID:27993951

Implementation science: a role for parallel dual processing models of reasoning?

PubMed Central

Sladek, Ruth M; Phillips, Paddy A; Bond, Malcolm J

2006-01-01

Background A better theoretical base for understanding professional behaviour change is needed to support evidence-based changes in medical practice. Traditionally strategies to encourage changes in clinical practices have been guided empirically, without explicit consideration of underlying theoretical rationales for such strategies. This paper considers a theoretical framework for reasoning from within psychology for identifying individual differences in cognitive processing between doctors that could moderate the decision to incorporate new evidence into their clinical decision-making. Discussion Parallel dual processing models of reasoning posit two cognitive modes of information processing that are in constant operation as humans reason. One mode has been described as experiential, fast and heuristic; the other as rational, conscious and rule based. Within such models, the uptake of new research evidence can be represented by the latter mode; it is reflective, explicit and intentional. On the other hand, well practiced clinical judgments can be positioned in the experiential mode, being automatic, reflexive and swift. Research suggests that individual differences between people in both cognitive capacity (e.g., intelligence) and cognitive processing (e.g., thinking styles) influence how both reasoning modes interact. This being so, it is proposed that these same differences between doctors may moderate the uptake of new research evidence. Such dispositional characteristics have largely been ignored in research investigating effective strategies in implementing research evidence. Whilst medical decision-making occurs in a complex social environment with multiple influences and decision makers, it remains true that an individual doctor's judgment still retains a key position in terms of diagnostic and treatment decisions for individual patients. This paper argues therefore, that individual differences between doctors in terms of reasoning are important considerations in any discussion relating to changing clinical practice. Summary It is imperative that change strategies in healthcare consider relevant theoretical frameworks from other disciplines such as psychology. Generic dual processing models of reasoning are proposed as potentially useful in identifying factors within doctors that may moderate their individual uptake of evidence into clinical decision-making. Such factors can then inform strategies to change practice. PMID:16725023

Implementation science: a role for parallel dual processing models of reasoning?

PubMed

Sladek, Ruth M; Phillips, Paddy A; Bond, Malcolm J

2006-05-25

A better theoretical base for understanding professional behaviour change is needed to support evidence-based changes in medical practice. Traditionally strategies to encourage changes in clinical practices have been guided empirically, without explicit consideration of underlying theoretical rationales for such strategies. This paper considers a theoretical framework for reasoning from within psychology for identifying individual differences in cognitive processing between doctors that could moderate the decision to incorporate new evidence into their clinical decision-making. Parallel dual processing models of reasoning posit two cognitive modes of information processing that are in constant operation as humans reason. One mode has been described as experiential, fast and heuristic; the other as rational, conscious and rule based. Within such models, the uptake of new research evidence can be represented by the latter mode; it is reflective, explicit and intentional. On the other hand, well practiced clinical judgments can be positioned in the experiential mode, being automatic, reflexive and swift. Research suggests that individual differences between people in both cognitive capacity (e.g., intelligence) and cognitive processing (e.g., thinking styles) influence how both reasoning modes interact. This being so, it is proposed that these same differences between doctors may moderate the uptake of new research evidence. Such dispositional characteristics have largely been ignored in research investigating effective strategies in implementing research evidence. Whilst medical decision-making occurs in a complex social environment with multiple influences and decision makers, it remains true that an individual doctor's judgment still retains a key position in terms of diagnostic and treatment decisions for individual patients. This paper argues therefore, that individual differences between doctors in terms of reasoning are important considerations in any discussion relating to changing clinical practice. It is imperative that change strategies in healthcare consider relevant theoretical frameworks from other disciplines such as psychology. Generic dual processing models of reasoning are proposed as potentially useful in identifying factors within doctors that may moderate their individual uptake of evidence into clinical decision-making. Such factors can then inform strategies to change practice.

Relativistic force field: parametric computations of proton-proton coupling constants in (1)H NMR spectra.

PubMed

Kutateladze, Andrei G; Mukhina, Olga A

2014-09-05

Spin-spin coupling constants in (1)H NMR carry a wealth of structural information and offer a powerful tool for deciphering molecular structures. However, accurate ab initio or DFT calculations of spin-spin coupling constants have been very challenging and expensive. Scaling of (easy) Fermi contacts, fc, especially in the context of recent findings by Bally and Rablen (Bally, T.; Rablen, P. R. J. Org. Chem. 2011, 76, 4818), offers a framework for achieving practical evaluation of spin-spin coupling constants. We report a faster and more precise parametrization approach utilizing a new basis set for hydrogen atoms optimized in conjunction with (i) inexpensive B3LYP/6-31G(d) molecular geometries, (ii) inexpensive 4-31G basis set for carbon atoms in fc calculations, and (iii) individual parametrization for different atom types/hybridizations, not unlike a force field in molecular mechanics, but designed for the fc's. With the training set of 608 experimental constants we achieved rmsd <0.19 Hz. The methodology performs very well as we illustrate with a set of complex organic natural products, including strychnine (rmsd 0.19 Hz), morphine (rmsd 0.24 Hz), etc. This precision is achieved with much shorter computational times: accurate spin-spin coupling constants for the two conformers of strychnine were computed in parallel on two 16-core nodes of a Linux cluster within 10 min.

Quantification of baseline pupillary response and task-evoked pupillary response during constant and incremental task load.

PubMed

Mosaly, Prithima R; Mazur, Lukasz M; Marks, Lawrence B

2017-10-01

The methods employed to quantify the baseline pupil size and task-evoked pupillary response (TEPR) may affect the overall study results. To test this hypothesis, the objective of this study was to assess variability in baseline pupil size and TEPR during two basic working memory tasks: constant load of 3-letters memorisation-recall (10 trials), and incremental load memorisation-recall (two trials of each load level), using two commonly used methods (1) change from trail/load specific baseline, (2) change from constant baseline. Results indicated that there was a significant shift in baseline between the trails for constant load, and between the load levels for incremental load. The TEPR was independent of shifts in baseline using method 1 only for constant load, and method 2 only for higher levels of incremental load condition. These important findings suggest that the assessment of both the baseline and methods to quantify TEPR are critical in ergonomics application, especially in studies with small number of trials per subject per condition. Practitioner Summary: Quantification of TEPR can be affected by shifts in baseline pupil size that are most likely affected by non-cognitive factors when other external factors are kept constant. Therefore, quantification methods employed to compute both baseline and TEPR are critical in understanding the information processing of humans in practical ergonomics settings.

A generalised age- and phase-structured model of human tumour cell populations both unperturbed and exposed to a range of cancer therapies.

PubMed

Basse, Britta; Ubezio, Paolo

2007-07-01

We develop a general mathematical model for a population of cells differentiated by their position within the cell division cycle. A system of partial differential equations governs the kinetics of cell densities in certain phases of the cell division cycle dependent on time t (hours) and an age-like variable tau (hours) describing the time since arrival in a particular phase of the cell division cycle. Transition rate functions control the transfer of cells between phases. We first obtain a theoretical solution on the infinite domain -infinity < t < infinity. We then assume that age distributions at time t=0 are known and write our solution in terms of these age distributions on t=0. In practice, of course, these age distributions are unknown. All is not lost, however, because a cell line before treatment usually lies in a state of asynchronous balanced growth where the proportion of cells in each phase of the cell cycle remain constant. We assume that an unperturbed cell line has four distinct phases and that the rate of transition between phases is constant within a short period of observation ('short' relative to the whole history of the tumour growth) and we show that under certain conditions, this is equivalent to exponential growth or decline. We can then gain expressions for the age distributions. So, in short, our approach is to assume that we have an unperturbed cell line on t

Dynamic Stability of the Rate, State, Temperature, and Pore Pressure Friction Model at a Rock Interface

NASA Astrophysics Data System (ADS)

Sinha, Nitish; Singh, Arun K.; Singh, Trilok N.

2018-05-01

In this article, we study numerically the dynamic stability of the rate, state, temperature, and pore pressure friction (RSTPF) model at a rock interface using standard spring-mass sliding system. This particular friction model is a basically modified form of the previously studied friction model namely the rate, state, and temperature friction (RSTF). The RSTPF takes into account the role of thermal pressurization including dilatancy and permeability of the pore fluid due to shear heating at the slip interface. The linear stability analysis shows that the critical stiffness, at which the sliding becomes stable to unstable or vice versa, increases with the coefficient of thermal pressurization. Critical stiffness, on the other hand, remains constant for small values of either dilatancy factor or hydraulic diffusivity, but the same decreases as their values are increased further from dilatancy factor (˜ 10^{ - 4} ) and hydraulic diffusivity (˜ 10^{ - 9} {m}2 {s}^{ - 1} ) . Moreover, steady-state friction is independent of the coefficient of thermal pressurization, hydraulic diffusivity, and dilatancy factor. The proposed model is also used for predicting time of failure of a creeping interface of a rock slope under the constant gravitational force. It is observed that time of failure decreases with increase in coefficient of thermal pressurization and hydraulic diffusivity, but the dilatancy factor delays the failure of the rock fault under the condition of heat accumulation at the creeping interface. Moreover, stiffness of the rock-mass also stabilizes the failure process of the interface as the strain energy due to the gravitational force accumulates in the rock-mass before it transfers to the sliding interface. Practical implications of the present study are also discussed.

Color-magnitude Diagrams for the Stellar Open Cluster M 67 in theVilnius Photometric System

NASA Astrophysics Data System (ADS)

Boyle, Richard P.; Janusz, Robert

2015-01-01

Stellar photometry in the Vilnius Photometric System requires one percent quality for deriving luminosity class and spectral type subclass. We use such existing photometry of the open cluster M 67 to calibrate new CCD observations at the Vatican Advanced Technology Telescope (VATT) for correcting the flat-fielding zero-point and deriving the color-transformation in this intermediate-band, seven filter system (Boyle et al., BAAS 37 #4, 2005).Recently we have developed a "tie-in" observational practice to apply the zero-point and color transformation of the M 67 observations to neighboring starfields of interest that have no existing photometry. Sky transparency must remain constant to better than one percent during a round of short exposures in a filter between the field having calibrated photometry and the new field having no photometry as if the new field was exposed simultaneously with the master field.Proof of success for this "tie-in" method is shown with the master field being M 67 and the "tie-in" field being the nearby extended "corona" area. The distinctive color-magnitude diagrams of the old open clusterM 67 reveal the sensitivity to having constant sky transparency during the round of short exposures on M 67 and its extended area. For the extended area has the same form in its color-magnitude diagram as M 67. So variation in sky transparency shows displacement on the color-magnitude diagrams at the one percent quality.We will attempt new analysis concerning evolution of this very old open cluster (2.56 Gyr, WEBDA, http://www.univie.ac.at/webda/) and the surrounding "coronal" extent with reference to previous work by Chupina and Vereshchagin (Astron. Astrophys, 334, 552, 1998).

An UXor among FUors: Extinction-related Brightness Variations of the Young Eruptive Star V582 Aur

NASA Astrophysics Data System (ADS)

Ábrahám, P.; Kóspál, Á.; Kun, M.; Fehér, O.; Zsidi, G.; Acosta-Pulido, J. A.; Carnerero, M. I.; García-Álvarez, D.; Moór, A.; Cseh, B.; Hajdu, G.; Hanyecz, O.; Kelemen, J.; Kriskovics, L.; Marton, G.; Mező, Gy.; Molnár, L.; Ordasi, A.; Rodríguez-Coira, G.; Sárneczky, K.; Sódor, Á.; Szakáts, R.; Szegedi-Elek, E.; Szing, A.; Farkas-Takács, A.; Vida, K.; Vinkó, J.

2018-01-01

V582 Aur is an FU Ori-type young eruptive star in outburst since ∼1985. The eruption is currently in a relatively constant plateau phase, with photometric and spectroscopic variability superimposed. Here we will characterize the progenitor of the outbursting object, explore its environment, and analyze the temporal evolution of the eruption. We are particularly interested in the physical origin of the two deep photometric dips, one that occurred in 2012 and one that is ongoing since 2016. We collected archival photographic plates and carried out new optical, infrared, and millimeter-wave photometric and spectroscopic observations between 2010 and 2018, with a high sampling rate during the current minimum. Besides analyzing the color changes during fading, we compiled multiepoch spectral energy distributions and fitted them with a simple accretion disk model. Based on pre-outburst data and a millimeter continuum measurement, we suggest that the progenitor of the V582 Aur outburst is a low-mass T Tauri star with average properties. The mass of an unresolved circumstellar structure, probably a disk, is 0.04 M ⊙. The optical and near-infrared spectra demonstrate the presence of hydrogen and metallic lines, show the CO band head in absorption, and exhibit a variable Hα profile. The color variations strongly indicate that both the ∼1 yr long brightness dip in 2012 and the current minimum since 2016 are caused by increased extinction along the line of sight. According to our accretion disk models, the reddening changed from A V = 4.5 to 12.5 mag, while the accretion rate remained practically constant. Similarly to the models of the UXor phenomenon of intermediate- and low-mass young stars, orbiting disk structures could be responsible for the eclipses.

Liquid film drag out in the presence of molecular forces

NASA Astrophysics Data System (ADS)

Schmidhalter, I.; Cerro, R. L.; Giavedoni, M. D.; Saita, F. A.

2013-03-01

From a practical as well as a conceptual point of view, one of the most interesting problems of physicochemical hydrodynamics is the drag out of a liquid film by a moving solid out of a pool of liquid. The basic problem, sometimes denoted the Landau-Levich problem [L. Landau and B. Levich, "Dragging of a liquid by a moving plate," Acta Physicochim. USSR 17, 42-54 (1942)], involves an interesting blend of capillary and viscous forces plus a matching of the static solution for capillary rise with a numerical solution of the film evolution equation, neglecting gravity, on the downstream region of the flow field. The original solution describes experimental data for a wide range of Capillary numbers but fails to match results for large and very small Capillary numbers. Molecular level forces are introduced to create an augmented version of the film evolution equation to show the effect of van der Waals forces at the lower range of Capillary numbers. A closed form solution for static capillary rise, including molecular forces, was matched with a numerical solution of the augmented film evolution equation in the dynamic meniscus region. Molecular forces do not sensibly modify the static capillary rise region, since film thicknesses are larger than the range of influence of van der Waals forces, but are determinant in shaping the downstream dynamic meniscus of the very thin liquid films. As expected, a quantitatively different level of disjoining pressure for different values of molecular constants remains in the very thin liquid film far downstream. Computational results for a wide range of Capillary numbers and Hamaker constants show a clear transition towards a region where the film thickness becomes independent of the coating speed.

Within-day variability on short and long walking tests in persons with multiple sclerosis.

PubMed

Feys, Peter; Bibby, Bo; Romberg, Anders; Santoyo, Carme; Gebara, Benoit; de Noordhout, Benoit Maertens; Knuts, Kathy; Bethoux, Francois; Skjerbæk, Anders; Jensen, Ellen; Baert, Ilse; Vaney, Claude; de Groot, Vincent; Dalgas, Ulrik

2014-03-15

To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Observational study. MS rehabilitation and research centers in Europe and US within RIMS (European network for best practice and research in MS rehabilitation). Ambulatory persons with MS (Expanded Disability Status Scale 0-6.5). Subjects of different centers performed walking tests at 3 time points during a single day. 10MWT, 2MWT and 6MWT at fastest speed and 10MWT at usual speed. Ninety-five percent limits of agreement were computed using a random effects model with individual pwMS as random effect. Following this model, retest scores are with 95% certainty within these limits of baseline scores. In 102 subjects, within-day variability was constant in absolute units for the 10MWT, 2MWT and 6MWT at fastest speed (+/-0.26, 0.16 and 0.15m/s respectively, corresponding to +/-19.2m and +/-54 m for the 2MWT and 6MWT) independent on the severity of ambulatory dysfunction. This implies a greater relative variability with increasing disability level, often above 20% depending on the applied test. The relative within-day variability of the 10MWT at usual speed was +/-31% independent of ambulatory function. Absolute values of within-day variability on walking tests at fastest speed were independent of disability level and greater with short compared to long walking tests. Relative within-day variability remained overall constant when measured at usual speed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Water Relations, Gas Exchange, and Nutrient Response to a Long Term Constant Water Deficit

NASA Technical Reports Server (NTRS)

Berry, Wade L.; Goldstein, Guillermo; Dreschel, Thomas W.; Wheeler, Raymond M.; Sager, John C.; Knott, William M.

1992-01-01

Wheat plants (Triticum aestivum) were grown for 43 days in a micro-porous tube nutrient delivery system. Roots were unable to penetrate the microporous tube, but grew on the surface and maintained capillary contact with the nutrient solution on the inside of the tube through the 5-micron pores of the porous tube. Water potential in the system was controlled at -0.4, -0.8, and -3.0 kPa by adjusting the applied pressure (hydrostatic head) to the nutrient solution flowing through the microporous tubes. A relatively small decrease in applied water potential from -0.4 to -3.0 kPa resulted in a 34% reduction of shoot growth but only a moderate reduction in the midday leaf water potential from -1.3 to -1.7 MPa. Carbon dioxide assimilation decreased and water use efficiency increased with the more negative applied water potentials, while intercellular CO2 concentration remained constant. This was associated with a decrease in stomatal conductance to water vapor from 1.90 to 0.98 mol/(sq m sec) and a decrease in total apparent hydraulic conductance from 47 to 12 (micro)mol/(sec MPa). Although the applied water potentials were in the -0.4 to -3.0 kPa range, the actual water potential perceived by the plant roots appeared to be in the range of -0.26 to -0.38 MPa as estimated by the leaf water potential of bagged plants. The amount of K, Ca, Mg, Zn, Cu, and B accumulated with each unit of transpired water increased as the applied water potential became less negative. The increase in accumulation ranged from 1.4-fold for K to 2.2-fold for B. The physiological responses observed in this study in response to small constant differences in applied water potentials were much greater than expected from either the applied water potential or the observed plant water potential. Even though the micro-porous tube may not represent natural conditions and could possibly introduce morphological and physiological artifacts, it enables a high degree of control of water potential that facilitates the investigation of many aspects of water relations not practical with other experimental systems.

Relative sensitivities of DCE-MRI pharmacokinetic parameters to arterial input function (AIF) scaling.

PubMed

Li, Xin; Cai, Yu; Moloney, Brendan; Chen, Yiyi; Huang, Wei; Woods, Mark; Coakley, Fergus V; Rooney, William D; Garzotto, Mark G; Springer, Charles S

2016-08-01

Dynamic-Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) has been used widely for clinical applications. Pharmacokinetic modeling of DCE-MRI data that extracts quantitative contrast reagent/tissue-specific model parameters is the most investigated method. One of the primary challenges in pharmacokinetic analysis of DCE-MRI data is accurate and reliable measurement of the arterial input function (AIF), which is the driving force behind all pharmacokinetics. Because of effects such as inflow and partial volume averaging, AIF measured from individual arteries sometimes require amplitude scaling for better representation of the blood contrast reagent (CR) concentration time-courses. Empirical approaches like blinded AIF estimation or reference tissue AIF derivation can be useful and practical, especially when there is no clearly visible blood vessel within the imaging field-of-view (FOV). Similarly, these approaches generally also require magnitude scaling of the derived AIF time-courses. Since the AIF varies among individuals even with the same CR injection protocol and the perfect scaling factor for reconstructing the ground truth AIF often remains unknown, variations in estimated pharmacokinetic parameters due to varying AIF scaling factors are of special interest. In this work, using simulated and real prostate cancer DCE-MRI data, we examined parameter variations associated with AIF scaling. Our results show that, for both the fast-exchange-limit (FXL) Tofts model and the water exchange sensitized fast-exchange-regime (FXR) model, the commonly fitted CR transfer constant (K(trans)) and the extravascular, extracellular volume fraction (ve) scale nearly proportionally with the AIF, whereas the FXR-specific unidirectional cellular water efflux rate constant, kio, and the CR intravasation rate constant, kep, are both AIF scaling insensitive. This indicates that, for DCE-MRI of prostate cancer and possibly other cancers, kio and kep may be more suitable imaging biomarkers for cross-platform, multicenter applications. Data from our limited study cohort show that kio correlates with Gleason scores, suggesting that it may be a useful biomarker for prostate cancer disease progression monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

Transverse vibrations of wood-based products : equations and considerations

Treesearch

Joseph F. Murphy

2011-01-01

Four equations are presented to determine bending stiffness using transverse vibration. These equations are used for constant cross-section products, panels, rectangular cross-section products, and logs with and without taper. Practical considerations for their use are discussed and concluding remarks are included.

Evaluation and comparison of diffusion MR methods for measuring apparent transcytolemmal water exchange rate constant

NASA Astrophysics Data System (ADS)

Tian, Xin; Li, Hua; Jiang, Xiaoyu; Xie, Jingping; Gore, John C.; Xu, Junzhong

2017-02-01

Two diffusion-based approaches, CG (constant gradient) and FEXI (filtered exchange imaging) methods, have been previously proposed for measuring transcytolemmal water exchange rate constant kin, but their accuracy and feasibility have not been comprehensively evaluated and compared. In this work, both computer simulations and cell experiments in vitro were performed to evaluate these two methods. Simulations were done with different cell diameters (5, 10, 20 μm), a broad range of kin values (0.02-30 s-1) and different SNR's, and simulated kin's were directly compared with the ground truth values. Human leukemia K562 cells were cultured and treated with saponin to selectively change cell transmembrane permeability. The agreement between measured kin's of both methods was also evaluated. The results suggest that, without noise, the CG method provides reasonably accurate estimation of kin especially when it is smaller than 10 s-1, which is in the typical physiological range of many biological tissues. However, although the FEXI method overestimates kin even with corrections for the effects of extracellular water fraction, it provides reasonable estimates with practical SNR's and more importantly, the fitted apparent exchange rate AXR showed approximately linear dependence on the ground truth kin. In conclusion, either CG or FEXI method provides a sensitive means to characterize the variations in transcytolemmal water exchange rate constant kin, although the accuracy and specificity is usually compromised. The non-imaging CG method provides more accurate estimation of kin, but limited to large volume-of-interest. Although the accuracy of FEXI is compromised with extracellular volume fraction, it is capable of spatially mapping kin in practice.

Parenting Practices in Cultural Context: An Ecological Perspective

ERIC Educational Resources Information Center

Zarnegar, Zohreh

2015-01-01

Despite general consensus that parenting practices influence the developmental processes of children, many questions about the impacts of parenting practices on child development within the cultural context remain unanswered. This article presents how cultural templates influence parenting practices and developmental processes of young children.…

Empowerment in the interpersonal field: discourses of acute mental health nurses.

PubMed

Lloyd, M

2007-08-01

Social policy greatly influences the working environment of mental health nurses but in practice can be difficult to translate. Empowerment of service users is one area that is constantly significant in policy, locally and nationally, yet quite difficult to define in practice. This ethnomethodological study explored the practice of 10 mental health nurses working in an acute admissions unit. Through semi-structured interviews, the nurses were asked to discuss the taken-for-granted methods of empowerment with individual service users, their families and with work colleagues. The results were thematically analysed and compared with international findings, which reflected an awareness among mental health nurses of empowering practice in four areas. These were: Working with mental illness, Making connections, Responsibility and Teamworking.

Shifting patterns of practice: nurse practitioners in a managed care environment.

PubMed

Johnson, Rosemary

2005-01-01

The purpose of this qualitative study was to uncover patterns across nurse practitioner (NP) experiences that contribute to understanding their perceptions of managed care, how it affects daily practice, and how NPs respond to a changing managed care workplace. In-depth interviews were conducted with 14 NPs representing primary care, specialty, and independent practices. Over an 18-month period, data collection and analysis occurred simultaneously using standard methods of purposive sampling, constant comparison, memoing, and member checks. This study illuminates the tension NPs experience between a business and a professional ethic and the strategies they use to reconcile this difference with core nursing values. Type of setting, workplace dynamics, and length of time in practice contributed to variation in NP perspectives.

Recruitment and Retention of Mathematics Students in Canadian Universities

ERIC Educational Resources Information Center

Fenwick-Sehl, Laura; Fioroni, Marcella; Lovric, Miroslav

2009-01-01

Data from Statistics Canada shows that while the number of mathematics degrees at the undergraduate and graduate levels remained relatively constant between 1992 and 2005, the total number of mathematics degrees as a percentage of all degrees awarded has slightly decreased over the same time period. To understand this situation better, we…

Urban and Community Forestry Achievements in 1998

Treesearch

Daniel Liptzin; Robert Neville

1999-01-01

The vision for urban and community forestry in the Northeastern Area has remained essentially constant since 1990, "...to achieve community sustainability and an enhanced quality of life through stewardship of urban and community forests and related natural resources." Implied in this statement is full participation by all those who affect or are affected by...

Bimodal Inverted Bell Grade Distribution: Implications for Instruction and Student Retention

ERIC Educational Resources Information Center

Gensheimer, Leah K.; Diebold, Charles T.

2014-01-01

College student attrition rates remain constant despite institution level efforts. This retrospective archival study examined how individual instructors at the course level might impact academic success and retention by acting on a real time at risk warning system. Five semesters of scores on the first exam in an undergraduate psychology course…

Kids and Guns. 1999 National Report Series. Juvenile Justice Bulletin.

ERIC Educational Resources Information Center

Department of Justice, Washington, DC. Office of Juvenile Justice and Delinquency Prevention.

This report provides information about the use of guns by children and adolescents, with related information on juvenile homicides and suicides. The annual number of juveniles killed with a firearm increased substantially between 1987 and 1993 as occurrences of other types of homicide remained constant. Since 1980, one in four murders of juveniles…

The Value of School Librarian Support in the Digital World

ERIC Educational Resources Information Center

Ballew, Linda M.

2014-01-01

The mission of school librarians in the digital age of information gathering and messaging has not undergone any real change of focus. Even though the tools and methods available for accessing information have significantly altered the way people now use library services, school libraries remain a constant place to make valuable discoveries. The…

38 CFR 8a.4 - Coverage.

Code of Federal Regulations, 2010 CFR

2010-07-01

....4 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS VETERANS MORTGAGE LIFE INSURANCE § 8a.4 Coverage. (a) The amount of VMLI in force on his or her life at any one time shall be... on the life of the veteran shall remain at a constant level until the principal amount of the...

American Higher Education in Transition

ERIC Educational Resources Information Center

Ehrenberg, Ronald G.

2011-01-01

American higher education is in transition and if there ever was a "golden age" for faculty, it probably is behind us. The best historical data on the composition of faculty is collected annually by the American Mathematical Society. Between 1967 and 2009, the share of full-time faculty with PhDs remained constant at about 90 percent at…

Bugs' bugs

Treesearch

May R. Berenbaum; Thomas Eisner

2008-01-01

Although scientific progress leads to constant reevaluation and revision of concepts and ideas, one observation that has remained robust in the face of accumulating evidence across the centuries is that there are a lot of insects in the world. In 1758, in his profoundly influential book Systema Naturae, Carolus Linnaeus (1) described all animal species known at the...

An Analysis of Compensation Systems for College and University Instructors

ERIC Educational Resources Information Center

Borovskaia, M. A.; Masych, M. A.; Bechvaia, M. R.

2014-01-01

Salaries and workplace conditions of teachers and researchers in Russian higher education are a barrier to recruitment of new staff, a source of loss as they move to better-paying occupations, and the cause of an aging professoriate. Laws to deal with this issue are constantly being passed, but the situation remains critical

A Comparison of Match-to-Sample and Respondent-Type Training of Equivalence Classes

ERIC Educational Resources Information Center

Clayton, Michael C.; Hayes, Linda J.

2004-01-01

Throughout the 25-year history of research on stimulus equivalence, one feature of the training procedure has remained constant, namely, the requirement of operant responding during the training procedures. The present investigation compared the traditional match-to-sample (MTS) training with a more recent respondent-type (ReT) procedure. Another…

Tuning In to Dropping Out

ERIC Educational Resources Information Center

Tabarrok, Alex

2012-01-01

Over the past 25 years, the total number of students in college has increased by about 50 percent. But the number of students graduating with degrees in science, technology, engineering, and mathematics (STEM) subjects has remained more or less constant. In 2009 the United States graduated 89,140 students in the visual and performing arts, more…

Note on the thermally induced changes of intervessel pits in black cherry (Prunus serotina EHRH)

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

Elder, T.J.; Murphey, W.K.; Blankenhorn, P.R.

1979-01-01

Dimensions of intervessel pits decrease as charring temperatures increase to 600 C; above 600 C pit apertures remain relatively constant. Reported increases in density of chars above 600 C are attributed to coalescing of the cell wall or changes in intercellular interstices shrinkage. 1 figure, 1 table.

Gender and Race in School Psychology

ERIC Educational Resources Information Center

Castillo, Jose M.; Curtis, Michael J.; Gelley, Cheryl D.

2013-01-01

In the past 2 decades the number of women in the field of school psychology has increased markedly, with some estimates suggesting that approximately 8 out of 10 school psychologists are women, but the percentage of school psychologists who are White has remained constant at approximately 90%. This study was conducted on behalf of the National…

Changes Coming to the International System of Units

ERIC Educational Resources Information Center

Aubrecht, Gordon J., II

2012-01-01

The International System of Units (SI) is a coherent system based originally on measurements of properties of material objects. In more recent times, the adopted definitions depend on setting values of universal constants wherever possible. The last remaining human-made material object on which a standard is based is a platinum-iridium kilogram…

Standardization of Selected Semantic Differential Scales with Secondary School Children.

ERIC Educational Resources Information Center

Evans, G. T.

A basic assumption of this study is that the meaning continuum registered by an adjective pair remains relatively constant over a large universe of concepts and over subjects within a relatively homogeneous population. An attempt was made to validate this assumption by showing the invariance of the factor structure across different types of…

A Resuscitation of Gifted Education

ERIC Educational Resources Information Center

Jolly, Jennifer L.

2009-01-01

Since its inception in the 1920s, the field of gifted education has remained in a constant ebb and flow. Public understanding and support, as well as, federal aid has mirrored this pattern, waxing and waning in response to national interests and concern from private institutions and foundations. Discourse between excellence and equity also has…

Safety of High Speed Ground Transportation Systems - Human Factors Phase II: Design and Evaluation of Decision Aids for Control of High-Speed Trains: Experiments and Model

DOT National Transportation Integrated Search

1996-12-01

Although the speed of some guided ground transportation systems continues to : increase, the reaction time and the sensory and information processing : capacities of railroad personnel remain constant. This second report in a : series examining criti...

Stabilizing Crystal Oscillators With Melting Metals

NASA Technical Reports Server (NTRS)

Stephens, J. B.; Miller, C. G.

1984-01-01

Heat of fusion provides extended period of constant temperature and frequency. Crystal surrounded by metal in spherical container. As outside temperature rises to melting point of metal, metal starts to liquefy; but temperature stays at melting point until no solid metal remains. Potential terrestrial applications include low-power environmental telemetering transmitters and instrumentation transmitters for industrial processes.

Cutting hardwood cants can boost sawmill profits

Treesearch

George R. Niskala; Thomas W., Jr. Church

1966-01-01

The markets for hardwood lumber are now strong, and sawmill profits are increasing. But this favorable market-price situation is the exception rather than the rule. Usually hardwood sawmill operators are confronted with ever-decreasing profit margins. During the past decade, while lumber prices have remained relatively constant, most logging and sawmilling costs have...

Origins of Newton's First Law

ERIC Educational Resources Information Center

Hecht, Eugene

2015-01-01

Anyone who has taught introductory physics should know that roughly a third of the students initially believe that any object at rest will remain at rest, whereas any moving body not propelled by applied forces will promptly come to rest. Likewise, about half of those uninitiated students believe that any object moving at a constant speed must be…

Rhetoric in Competition: The Formation of Organizational Discourse in Conference on College Composition and Communication Abstracts.

ERIC Educational Resources Information Center

Faber, Brenton

1996-01-01

Explores features of conference proposals submitted to the Conference on College Composition in 1989, 1990, and 1992--345 abstracts in total. Results showed that successful abstracts were more likely to follow generic qualities associated with "unsolicited proposals"; foundational discourse remained constant throughout the abstracts but…

Integrating Behavioral Psychology Services into Adult Day Programming for Individuals with Dementia

ERIC Educational Resources Information Center

LeBlanc, Linda A.

2010-01-01

Many individuals with dementia and problem behavior are served in nursing home settings long before health issues necessitate constant medical care. Alternative community-based adult day health care programs allow individuals with dementia to remain in their home with their families at a substantially reduced cost; however, many adult day programs…

Pyrolysis-crystallinity relationships in cellulose

Treesearch

M. Weinstein; A. Broido

1970-01-01

During pyrolysis of pure cellulose, the Crystallinity Index (Crl) remained fairly constant over more than 50% weight loss before dropping rapidly as the X-ray pattern deteriorated. With samples first treated with trace quantities of inorganic salts, heating first increased the Crl—the results implying a preferentially catalyzed decomposition of the amorphous regions....

Skills Certifications and Workforce Development: Partnering with Industry and Ourselves.

ERIC Educational Resources Information Center

Cantor, Jeffrey A.

2002-01-01

This article states that constant changing workplace technology requirements have placed a burden on the employees to remain competent. This problem can be alleviated by community colleges that offer credentials in different occupations. Community colleges can aid in the creation of new jobs by providing students with the skills that are highly…

Starting Silicon-Ribbon Growth Automatically

NASA Technical Reports Server (NTRS)

Mchugh, J. P.

1984-01-01

Semiautomatic system starts growth of silicon sheets more reliably than system with purely manual control. Control signals for starting sheetcrystal growth consist of ramps (during which signal changes linearly from one value to another over preset time interval) and soaks (during which signal remains constant). Ramps and soaks for best temperature and pulling speed determined by experimentation.

"L.I.F.E.": A School-Based Heart-Health Screening and Intervention Program

ERIC Educational Resources Information Center

Northrup, Karen L.; Cottrell, Lesley A.; Wittberg, Richard A.

2008-01-01

This article describes the development and growth of "Lifestyle Improvements in the Family Environment" ("L.I.F.E."), a school-based heart-health screening and intervention program. The primary goals of "L.I.F.E." through three rounds of grant funding remained constant: (a) to identify cardiovascular risk factors in…

“SNP Snappy”: A Strategy for Fast Genome-Wide Association Studies Fitting a Full Mixed Model

PubMed Central

Meyer, Karin; Tier, Bruce

2012-01-01

A strategy to reduce computational demands of genome-wide association studies fitting a mixed model is presented. Improvements are achieved by utilizing a large proportion of calculations that remain constant across the multiple analyses for individual markers involved, with estimates obtained without inverting large matrices. PMID:22021386

Time-Varying Effects of Family Ethnic Socialization on Ethnic-Racial Identity Development among Latino Adolescents

ERIC Educational Resources Information Center

Douglass, Sara; Umaña-Taylor, Adriana J.

2016-01-01

Previous research has established that family ethnic socialization messages promote ethnic-racial identity (ERI) development, yet it is unknown whether these effects remain constant throughout adolescence. The current study examined the time-varying effects of family ethnic socialization on ERI exploration and resolution among Latino adolescents…

Monitoring U.S. forest dynamics with Landsat [Chapter 12

Treesearch

Jeffrey G. Masek; Sean P. Healey

2012-01-01

Forest dynamics in the United States differ substantially from those in the developing world and thus present unique monitoring requirements. While deforestation and conversion to semipermanent agriculture dominate tropical forest dynamics, the area of forest land in the United States has remained fairly constant for the last 50-60 years (Birdsey and Lewis 2003)....

Focus on Balance, Not Black Swans

ERIC Educational Resources Information Center

Williams, Rodnie; Peterson, Josh

2012-01-01

The speed and access of information today has increased the scrutiny level facing risk managers in higher education. It is true that a more complex, more connected world has created new risks and new issues for university leadership. However, a lot of the same issues have remained constant for campuses: (1) emergency management; (2) campus safety;…

Experimental study of the isovector giant dipole resonance in 80Zr and 81Rb

NASA Astrophysics Data System (ADS)

Ceruti, S.; Camera, F.; Bracco, A.; Mentana, A.; Avigo, R.; Benzoni, G.; Blasi, N.; Bocchi, G.; Bottoni, S.; Brambilla, S.; Crespi, F. C. L.; Giaz, A.; Leoni, S.; Million, B.; Morales, A. I.; Nicolini, R.; Pellegri, L.; Riboldi, S.; Wieland, O.; Bazzacco, D.; Ciemala, M.; Farnea, E.; Gottardo, A.; Kmiecik, M.; Maj, A.; Mengoni, D.; Michelagnoli, C.; Modamio, V.; Montanari, D.; Napoli, D.; Recchia, F.; Sahin, E.; Ur, C.; Valiente-Dobón, J. J.; Wasilewska, B.; Zieblinski, M.

2017-01-01

The isovector giant dipole resonance (IVGDR) γ decay was measured in the compound nuclei 80Zr and 81Rb at an excitation energy of E*=54 MeV. The fusion reaction 40Ca+40Ca at Ebeam=136 MeV was used to form the compound nucleus 80Zr, while the reaction 37Cl+44Ca at Ebeam=95 MeV was used to form the compound nucleus 81Rb at the same excitation energy. The IVGDR parameters extracted from the analysis were compared with the ones found at higher excitation energy (E*=83 MeV). The comparison allows one to observe two different nuclear mechanisms: (i) the IVGDR intrinsic width remains constant with the excitation energy in the nucleus 81Rb; (ii) the isospin-violating spreading width (i.e., Coulomb spreading width) remains constant with the excitation energy in the nucleus 80Zr. The experimental setup used for the γ -ray detection was composed by the AGATA demonstrator array coupled to the large-volume LaBr3:Ce detectors of the HECTOR+ array.

Field experience and performance evaluation of a medium-concentration CPV system

NASA Astrophysics Data System (ADS)

Norton, Matthew; Bentley, Roger; Georghiou, George E.; Chonavel, Sylvain; De Mutiis, Alfredo

2012-10-01

With the aim of gaining experience and performance data from location with a harsh summer climate, a 70 X concentrating photovoltaic (CPV) system was installed in Janurary 2009 in Nicosia, Cyprus. The performance of this system has been monitored using regular current-voltage characterisations for three years. Over this period, the output of the system has remained fairly constant. Measured performance ratios varied from 0.79 to 0.86 in the winter, but fell to 0.64 over the year when left uncleaned. Operating cell temperatures were modeled and found to be similar to those of flat plate modules. The most significant causes of energy loss have been identified as originating from tracking issues and soiling. Losses due to soiling could account for a drop in output of 0.2% per day. When cleaned and properly oriented, the normalized output of the system has remained constant, suggesting that this particular design is tolerant to the physical strain of long-term outdoor exposure in harsh summer conditions. Regular cleaning and reliable tracker operation are shown to be essential for maximizing energy yield.

Visuomotor Dissociation in Cerebral Scaling of Size.

PubMed

Potgieser, Adriaan R E; de Jong, Bauke M

2016-01-01

Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

Animal use for science in Europe.

PubMed

Daneshian, Mardas; Busquet, Francois; Hartung, Thomas; Leist, Marcel

2015-01-01

To investigate long-term trends of animal use, the EU animal use statistics from the 15 countries that have been in the EU since 1995 plus respective data from Switzerland were analyzed. The overall number of animals used for scientific purposes in these countries, i.e., about 11 million/year, remained relatively constant between 1995 and 2011, with net increases in Germany and the UK and net decreases in Belgium, Denmark, Italy, Finland, the Netherlands and Sweden. The relatively low and constant numbers of experimental animals used for safety assessment (toxicology, 8%) may be due to the particularly intensive research on alternative methods in this area. The many efficiently working NGOs, multiple initiatives of the European Parliament, and coordinated activities of industry and the European Commission may have contributed to keeping the animal numbers in this field in check. Basic biological science, and research and development for medicine, veterinary and dentistry together currently make up 65% of animal use in science. Although the total numbers have remained relatively constant, consumption of transgenic animals has increased drastically; in Germany transgenic animals accounted for 30% of total animal use in 2011. Therefore, more focus on alternatives to the use of animals in biomedical research, in particular on transgenic animals, will be important in the future. One initiative designed to provide inter-sector information exchange for future actions is the "MEP - 3Rs scientists pairing scheme" initiated in 2015 by CAAT-Europe and MEP Pietikäinen.

Impoverishment of practice: analysis of effects of economic discourses in home care case management practice.

PubMed

Ceci, Christine

2006-03-01

Home care is a health sector under increasing pressure. Demand is often said to be outstripping capacity, with constant change and retrenchment distinguishing features of the current context. This paper takes a reading of the current conditions of home care using data gathered during a field study of home care case management practices conducted in 2004. As economic discourses become increasingly influential in determining responses to client situations, case managers (and their managers) find themselves with limited capacity to exercise control over their practices. A growing gap between professionally influenced discourses--those presumably intended to guide practice--and organizational priorities creates a dissonance for case managers as the political-ethical dimensions of their practices are displaced by budget "realities." For front-line workers, such displacement cannot be sustained in their face-to-face encounters with clients, leading to a growing sense of frustration and powerlessness among these highly skilled practitioners.

Prolonged Perceptual Learning of Positional Acuity in Adult Amblyopia

PubMed Central

Li, Roger W; Klein, Stanley A; Levi, Dennis M

2009-01-01

Amblyopia is a developmental abnormality that results in physiological alterations in the visual cortex and impairs form vision. It is often successfully treated by patching the sound eye in infants and young children, but is generally considered to be untreatable in adults. However, a number of recent studies suggest that repetitive practice of a visual task using the amblyopic eye results in improved performance in both children and adults with amblyopia. These perceptual learning studies have used relatively brief periods of practice; however, clinical studies have shown that the time-constant for successful patching is long. The time-constant for perceptual learning in amblyopia is still unknown. Here we show that the time-constant for perceptual learning depends on the degree of amblyopia. Severe amblyopia requires more than 50 hours (≈35,000 trials) to reach plateau, yielding as much as a five-fold improvement in performance at a rate of ≈1.5% per hour. There is significant transfer of learning from the amblyopic to the dominant eye, suggesting that the learning reflects alterations in higher decision stages of processing. Using a reverse correlation technique, we document, for the first time, a dynamic retuning of the amblyopic perceptual decision template and a substantial reduction in internal spatial distortion. These results show that the mature amblyopic brain is surprisingly malleable, and point to more intensive treatment methods for amblyopia. PMID:19109504

Living better with dementia: strengths-based social work practice and dementia care.

PubMed

McGovern, Justine

2015-01-01

This article first argues that quality of life is possible despite the onset of dementia in late life. It also demonstrates how core concepts of social work practice, such as family systems theory, the strengths perspective, and use of self, can be applied to practice with dementia-affected persons. In addition, it provides practical suggestions for supporting care partners in nurturing "we-ness", focusing on what remains rather than was is lost, and remaining authentic. When strengths-based social work practice is integrated into dementia care protocols, wellbeing can increase. As a result, the more than 40 million persons worldwide who are affected by dementia do not have to resign themselves to the despair, devastation and inevitable demise of quality of life that dominate perception of the illness.

Culturally Responsive Teaching in the Context of Mathematics: A Grounded Theory Case Study

ERIC Educational Resources Information Center

Bonner, Emily P.; Adams, Thomasenia L.

2012-01-01

In this grounded theory case study, four interconnected, foundational cornerstones of culturally responsive mathematics teaching (CRMT), communication, knowledge, trust/relationships, and constant reflection/revision, were systematically unearthed to develop an initial working theory of CRMT that directly informs classroom practice. These…

The Monmouth University Partnership: Redesigning Practice

ERIC Educational Resources Information Center

Henning, John E.; Bragen, Bernard F., Jr.; Mulvaney, Tracy; George, William O., III.; Duffy, Greg; Aldarelli, Edward; Grabowski, Christine; Harriott, Wendy; Riddle, Meredith; Falco, James; Heaney, Patricia; Earle, Corina; Foster, Linda; Borlan, Christine A.

2018-01-01

In this article, the Monmouth University partners describe our efforts to constantly explore new dimensions of learning, teaching, and teacher preparation. We begin by describing two recent initiatives developed by our partnership: the piloting and implementation of a yearlong clinical internship experience to replace traditional student teaching,…

Bullying and Cyberbullying: What Every Educator Needs to Know

ERIC Educational Resources Information Center

Englander, Elizabeth Kandel

2013-01-01

"Bullying is a term that's being, well, bullied. It's been rendered essentially powerless by being constantly kicked around," writes nationally recognized bullying expert Elizabeth Kandel Englander. In this practical and insightful book, Englander dispels pervasive myths and misconceptions about peer cruelty, bullying, and cyberbullying.…

Practicing Improvisation: Preparing Multicultural Educators

ERIC Educational Resources Information Center

Hull, Karla

2015-01-01

Preparing competent multicultural educators involves a dynamic process requiring constant self-reflection and assisting pre-service teachers to sharpen their cultural vision as they learn to be responsive educators. Reflections on lessons learned as a teacher educator are shared through personal experiences that are identified as keys to prepare…

Online People Tagging: Social (Mobile) Network(ing) Services and Work-Based Learning

ERIC Educational Resources Information Center

Cook, John; Pachler, Norbert

2012-01-01

Social and mobile technologies offer users unprecedented opportunities for communicating, interacting, sharing, meaning-making, content and context generation. And, these affordances are in constant flux driven by a powerful interplay between technological innovation and emerging cultural practices. Significantly, also, they are starting to…

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

Haddad, D., E-mail: darine.haddad@nist.gov; Seifert, F.; Williams, C.

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. We describe in this paper the fourth-generation watt balance at the National Institute of Standards and Technology (NIST), and report our initial determination of the Planck constant obtained from data taken in late 2015 and the beginning ofmore » 2016. A comprehensive analysis of the data and the associated uncertainties led to the SI value of the Planck constant, h = 6.626 069 83(22) × 10{sup −34} J s. The relative standard uncertainty associated with this result is 34 × 10{sup −9}.« less

An analysis of HPV infection incidence and clearance by genotype and age in men: The HPV Infection in Men (HIM) Study.

PubMed

Ingles, Donna J; Lin, Hui-Yi; Fulp, William J; Sudenga, Staci L; Lu, Beibei; Schabath, Matthew B; Papenfuss, Mary R; Abrahamsen, Martha E; Salmeron, Jorge; Villa, Luisa L; Ponce, Eduardo Lazcano; Giuliano, Anna R

2015-12-01

Genital HPV infection in men causes benign and cancerous lesions, the incidence of which differs by age. The goal of this work was to comprehensively evaluate incidence and clearance of individual HPV genotypes among men by age group. HIV-negative men ages 18-70 with no history of anogenital cancer were recruited for the HPV Infection in Men (HIM) Study . Participants completed clinical exams and questionnaires every six months for up to ~4 years. Genital specimens underwent HPV genotyping, with associations between age and HPV assessed using Cox analyses. 4085 men were followed for a median of 48.6 months (range: 0.3-94.0). Significantly lower HPV incidence rates were observed among the oldest age group (55-70 years) for grouped high-risk (incidence rate ratio [IRR]=0.71), HPV16 (IRR=0.54), grouped low-risk (IRR=0.74), and HPV6 (IRR=0.57) infections compared to men ages 18-24. However, incidence of the grouped 9-valent HPV vaccine types remained constant across the lifespan. Likelihood of HPV6 and HPV16 clearance remained constant until age 54, then increased significantly for men ages 55-70 (adjusted hazard ratio [AHR]=1.92 and 1.65, respectively). Men remain susceptible to HPV infections throughout their lifespan, highlighting the need for prevention efforts with long-lasting duration.

Evaluation of tablet computers for visual function assessment.

PubMed

Bodduluri, Lakshmi; Boon, Mei Ying; Dain, Stephen J

2017-04-01

Recent advances in technology and the increased use of tablet computers for mobile health applications such as vision testing necessitate an understanding of the behavior of the displays of such devices, to facilitate the reproduction of existing or the development of new vision assessment tests. The purpose of this study was to investigate the physical characteristics of one model of tablet computer (iPad mini Retina display) with regard to display consistency across a set of devices (15) and their potential application as clinical vision assessment tools. Once the tablet computer was switched on, it required about 13 min to reach luminance stability, while chromaticity remained constant. The luminance output of the device remained stable until a battery level of 5%. Luminance varied from center to peripheral locations of the display and with viewing angle, whereas the chromaticity did not vary. A minimal (1%) variation in luminance was observed due to temperature, and once again chromaticity remained constant. Also, these devices showed good temporal stability of luminance and chromaticity. All 15 tablet computers showed gamma functions approximating the standard gamma (2.20) and showed similar color gamut sizes, except for the blue primary, which displayed minimal variations. The physical characteristics across the 15 devices were similar and are known, thereby facilitating the use of this model of tablet computer as visual stimulus displays.

Using milk fat to reduce the irritation and bitter taste of ibuprofen

PubMed Central

Bennett, Samantha M.; Zhou, Lisa; Hayes, John E.

2012-01-01

Bitterness and irritation elicited by pharmaceutically active molecules remain problematic for pediatric medications, fortified foods and dietary supplements. Few effective methods exist for reducing these unpalatable sensations, negatively impacting medication compliance and intake of beneficial phytonutrients. A physicochemical approach to masking these sensations may be the most successful approach for generalizability to a wide range of structurally and functionally unique compounds. Here, solutions of the non-steroidal anti- inflammatory drug, ibuprofen, were prepared in milk products with varying fat content. Our hypothesis, based on other reports of similar phenomena, was that increasing the fat content would cause ibuprofen to selectively partition into the fat phase, thereby reducing interaction with sensory receptors and decreasing adversive sensations. Quantification of the aqueous concentration of ibuprofen was performed using an isocratic HPLC method coupled with an external standard curve. Sensory testing showed a modest but significant decrease (~20%) in irritation ratings between the skim milk (0% fat) and the half-and-half (11% fat) samples, indicating that increased fat may contribute to a reduced sensory response. Bitterness was not reduced, remaining constant over all fat levels. The HPLC results indicate a constant amount of ibuprofen remained in the aqueous phase regardless of fat level, so a simple partitioning hypothesis cannot explain the reduced irritancy ratings. Association of ionized ibuprofen with continuous phase solutes such as unabsorbed protein should be explored in future work. PMID:23527314

Impact of shelf life on content of primary and secondary metabolites in apple (Malus domestica Borkh.).

PubMed

Veberic, Robert; Schmitzer, Valentina; Petkovsek, Maja M; Stampar, Franci

2010-01-01

In this study, we evaluated the changes in apple fruit quality during shelf life. After a month of cold storage, apples of cultivars "Jonagold" and "Golden Delicious" were exposed to ambient temperatures for 21 d, with subsequent sampling every 3 or 4 d. Fruit firmness, changes in amounts of sugars, malic acid, and phenolics were observed during shelf life. Chemical analyses were done with HPLC-PDA system. An interchange between various sugars was noticed, but in general, the sum of sugars remained at the same level. The content of malic acid remained stable or dropped, resulting in sweeter fruit. Levels of phenolics were more constant in the pulp of both cultivars analyzed, while in the peel, the changes were more pronounced. In the pulp, a peak in the content of hydroxycinnamic acids and flavanols was noticed on the 2nd or 3rd sampling and afterwards, the amounts remained constant. In the peel an initial decrease of all analyzed phenolic groups was observed in both cultivars, however it was more pronounced in "Jonagold." It can be concluded that changes in primary and secondary metabolites are not the main reason for the lower quality of fruit exposed to ambient temperatures. On the other hand, fruit firmness might be the limiting factor for shelf life duration. © 2010 Institute of Food Technologists®

Relationship of mother and child food purchases as a function of price: a pilot study.

PubMed

Epstein, Leonard H; Dearing, Kelly K; Handley, Elizabeth A; Roemmich, James N; Paluch, Rocco A

2006-07-01

To our knowledge, there are no data on parental influences on child purchasing behavior of healthy or unhealthy foods. Mothers and children in ten families were given 5.00 US dollars to purchase portions of preferred fruits/vegetables and high energy-dense snack foods for each of ten trials of price manipulations. For five of the trials the price of the fruit/vegetable increased in price from 0.50 US dollars to 2.50 US dollars (in 0.50 US dollar increments), while the price of the energy-dense snack food remained constant at 1.00 US dollar. For the remaining five trials, the commodity that previously rose in price remained constant at 1.00 US dollars and the other commodity varied from 0.50 US dollars to 2.50 US dollars. Same-price elasticity was shown for both the child and parent purchases, and parent purchases were significantly related to child purchases of both healthy (regression estimate = 0.46, p < 0.001) and unhealthy (regression estimate = 0.12, p = 0.036) foods. Children's purchases of unhealthy snack food items were positively related to family socioeconomic status, and negatively related to child age. These results indicate that parental food choice and purchasing behaviors may play a role in the development of children's purchasing of both healthy and unhealthy foods.

Automatic exposure control systems designed to maintain constant image noise: effects on computed tomography dose and noise relative to clinically accepted technique charts.

PubMed

Favazza, Christopher P; Yu, Lifeng; Leng, Shuai; Kofler, James M; McCollough, Cynthia H

2015-01-01

To compare computed tomography dose and noise arising from use of an automatic exposure control (AEC) system designed to maintain constant image noise as patient size varies with clinically accepted technique charts and AEC systems designed to vary image noise. A model was developed to describe tube current modulation as a function of patient thickness. Relative dose and noise values were calculated as patient width varied for AEC settings designed to yield constant or variable noise levels and were compared to empirically derived values used by our clinical practice. Phantom experiments were performed in which tube current was measured as a function of thickness using a constant-noise-based AEC system and the results were compared with clinical technique charts. For 12-, 20-, 28-, 44-, and 50-cm patient widths, the requirement of constant noise across patient size yielded relative doses of 5%, 14%, 38%, 260%, and 549% and relative noises of 435%, 267%, 163%, 61%, and 42%, respectively, as compared with our clinically used technique chart settings at each respective width. Experimental measurements showed that a constant noise-based AEC system yielded 175% relative noise for a 30-cm phantom and 206% relative dose for a 40-cm phantom compared with our clinical technique chart. Automatic exposure control systems that prescribe constant noise as patient size varies can yield excessive noise in small patients and excessive dose in obese patients compared with clinically accepted technique charts. Use of noise-level technique charts and tube current limits can mitigate these effects.

Path Following in the Exact Penalty Method of Convex Programming.

PubMed

Zhou, Hua; Lange, Kenneth

2015-07-01

Classical penalty methods solve a sequence of unconstrained problems that put greater and greater stress on meeting the constraints. In the limit as the penalty constant tends to ∞, one recovers the constrained solution. In the exact penalty method, squared penalties are replaced by absolute value penalties, and the solution is recovered for a finite value of the penalty constant. In practice, the kinks in the penalty and the unknown magnitude of the penalty constant prevent wide application of the exact penalty method in nonlinear programming. In this article, we examine a strategy of path following consistent with the exact penalty method. Instead of performing optimization at a single penalty constant, we trace the solution as a continuous function of the penalty constant. Thus, path following starts at the unconstrained solution and follows the solution path as the penalty constant increases. In the process, the solution path hits, slides along, and exits from the various constraints. For quadratic programming, the solution path is piecewise linear and takes large jumps from constraint to constraint. For a general convex program, the solution path is piecewise smooth, and path following operates by numerically solving an ordinary differential equation segment by segment. Our diverse applications to a) projection onto a convex set, b) nonnegative least squares, c) quadratically constrained quadratic programming, d) geometric programming, and e) semidefinite programming illustrate the mechanics and potential of path following. The final detour to image denoising demonstrates the relevance of path following to regularized estimation in inverse problems. In regularized estimation, one follows the solution path as the penalty constant decreases from a large value.

Path Following in the Exact Penalty Method of Convex Programming

PubMed Central

Zhou, Hua; Lange, Kenneth

2015-01-01

Classical penalty methods solve a sequence of unconstrained problems that put greater and greater stress on meeting the constraints. In the limit as the penalty constant tends to ∞, one recovers the constrained solution. In the exact penalty method, squared penalties are replaced by absolute value penalties, and the solution is recovered for a finite value of the penalty constant. In practice, the kinks in the penalty and the unknown magnitude of the penalty constant prevent wide application of the exact penalty method in nonlinear programming. In this article, we examine a strategy of path following consistent with the exact penalty method. Instead of performing optimization at a single penalty constant, we trace the solution as a continuous function of the penalty constant. Thus, path following starts at the unconstrained solution and follows the solution path as the penalty constant increases. In the process, the solution path hits, slides along, and exits from the various constraints. For quadratic programming, the solution path is piecewise linear and takes large jumps from constraint to constraint. For a general convex program, the solution path is piecewise smooth, and path following operates by numerically solving an ordinary differential equation segment by segment. Our diverse applications to a) projection onto a convex set, b) nonnegative least squares, c) quadratically constrained quadratic programming, d) geometric programming, and e) semidefinite programming illustrate the mechanics and potential of path following. The final detour to image denoising demonstrates the relevance of path following to regularized estimation in inverse problems. In regularized estimation, one follows the solution path as the penalty constant decreases from a large value. PMID:26366044

Low-pressure hydrogen plasmas explored using a global model

NASA Astrophysics Data System (ADS)

Samuell, Cameron M.; Corr, Cormac S.

2016-02-01

Low-pressure hydrogen plasmas have found applications in a variety of technology areas including fusion, neutral beam injection and material processing applications. To better understand these discharges, a global model is developed to predict the behaviour of electrons, ground-state atomic and molecular hydrogen, three positive ion species (H+, \\text{H}2+ , and \\text{H}3+ ), a single negative ion species (H-), and fourteen vibrationally excited states of molecular hydrogen ({{\\text{H}}2}≤ft(\\upsilon =1\\right. -14)). The model is validated by comparison with experimental results from a planar inductively coupled GEC reference cell and subsequently applied to the MAGPIE linear helicon reactor. The MAGPIE reactor is investigated for a range of pressures from 1 to 100 mTorr and powers up to 5 kW. With increasing power between 50 W and 5 kW at 10 mTorr the density of all charged species increases as well as the dissociative fraction while the electron temperature remains almost constant at around 3 eV. For gas pressures from 1-100 mTorr at an input power of 1 kW, the electron density remains almost constant, the electron temperature and dissociative fraction decreases, while \\text{H}3+ density increases in density and also dominates amongst ion species. Across these power and pressure scans, electronegativity remains approximately constant at around 2.5%. The power and pressure determines the dominant ion species in the plasma with \\text{H}3+ observed to dominate at high pressures and low powers whereas H+ tends to be dominant at low pressures and high powers. A sensitivity analysis is used to demonstrate how experimental parameters (power, pressure, reactor wall material, geometry etc) influence individual species’ density as well as the electron temperature. Physical reactor changes including the length, radius and wall recombination coefficient are found to have the largest influence on outputs obtained from the model.

Synthesis of amphipathic block copolymers based on polyisobutylene and polyoxyethylene and their application in emulsion polymerization

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

Sar, B.

1992-12-31

Polymer colloids stabilized by polymeric surfactants are of great interest both commercially and academically. It has been found that these materials enhance latex stabilization in a number of applications. The polymeric surfactants are amphipathic block and graft copolymers containing both hydrophilic and hydrophobic moieties. The current study involved the synthesis of a series of amphipathic triblock copolymers, polyisobutylene-block-polyoxyethylene-block-polyisobutylene (PIB-b-POE-b-PIB), for use in the emulsion polymerization of styrene (STY), methyl methacrylate (MMA), and vinyl acetate (VAc). The stabilizing effectiveness of these triblock copolymers was studied as a function of their blocklength. When the molecular weight of the POE center block wasmore » changed from M{sub n} = 2,000 to 20,000 g/mole, stable lattices were obtained in emulsion polymerization with MMA, STY, and VAc as the monomers. In all cases, the polymerization rates remained constant, while the number of particles/volume decreased with increasing POE chain length. When the molecular weight of the PIB end blocks was changed from M{sub n} = 400 to 2,600 g/mole keeping the molecular weight of the POE center block constant at M{sub n} = 20,000 g/mole, the poly(methyl methacrylate) and poly(vinyl acetate) lattices exhibited similar behavior, i.e., the number of particles and particle sizes remained the same, but the rate of polymerization reached a maximum at 87 wt% POE content. In the case of poly(styrene) both the rate of polymerization and the number of particles remained constant. The emulsion polymerization of other monomers such as butadiene, acrylonitrile, methyl acrylate, ethyl acrylate, and butyl acrylate was carried out by using one triblock copolymer, i.e., PIB(400)-b-POE (8,000)-b-PIB-(400). Stable lattices were also formed in all cases.« less

Modeling the human as a controller in a multitask environment

NASA Technical Reports Server (NTRS)

Govindaraj, T.; Rouse, W. B.

1978-01-01

Modeling the human as a controller of slowly responding systems with preview is considered. Along with control tasks, discrete noncontrol tasks occur at irregular intervals. In multitask situations such as these, it has been observed that humans tend to apply piecewise constant controls. It is believed that the magnitude of controls and the durations for which they remain constant are dependent directly on the system bandwidth, preview distance, complexity of the trajectory to be followed, and nature of the noncontrol tasks. A simple heuristic model of human control behavior in this situation is presented. The results of a simulation study, whose purpose was determination of the sensitivity of the model to its parameters, are discussed.

Numerical modelling of the flow and isotope separation in centrifuge Iguasu for different lengths of the rotor

NASA Astrophysics Data System (ADS)

Bogovalov, S. V.; Borisevich, V. D.; Borman, V. D.; Tronin, I. V.; Tronin, V. N.

2016-06-01

Numerical modelling and optimization of the gas flow and isotope separation in the Iguasu gas centrifuge (GC) for uranium enrichment have been performed for different lengths of the rotor. The calculations show that the specific separative power of the GC reduces with the length of the rotor. We show that the reduction of the specific separative power is connected with the growth of the pressure in the optimal regime and corresponding growth of temperature to prevent the working gas sublimation. The specific separative power remains constant with the growth of the rotor length provided that the temperature of the gas is taken to be constant.

Numerical Modeling of Dependence of Separative Power of the Gas Centrifuge on the Length of Rotor

NASA Astrophysics Data System (ADS)

Bogovalov, S. V.; Borisevich, V. D.; Borman, V. D.; Tronin, I. V.; Tronin, V. N.

Numerical modelling and optimization of the gas flow and isotope separation in the Iguasu gas centrifuge (GC) for uranium enrichment have been performed for different lengths of the rotor. The calculations show that the specific separative power of the GC reduces with the length of the rotor. We show that the reduction of the specific separative power is connected with the growth of the pressure in the optimal regime and corresponding growth of temperature to prevent the working gas sublimation. The specific separative power remains constant with the growth of the rotor length provided that the temperature of the rotor is taken to be constant.

Numerical modelling of the flow and isotope separation in centrifuge Iguasu for different lengths of the rotor

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

Bogovalov, S. V.; Borisevich, V. D.; Borman, V. D.

Numerical modelling and optimization of the gas flow and isotope separation in the Iguasu gas centrifuge (GC) for uranium enrichment have been performed for different lengths of the rotor. The calculations show that the specific separative power of the GC reduces with the length of the rotor. We show that the reduction of the specific separative power is connected with the growth of the pressure in the optimal regime and corresponding growth of temperature to prevent the working gas sublimation. The specific separative power remains constant with the growth of the rotor length provided that the temperature of the gasmore » is taken to be constant.« less

Convection in the Rayleigh-Bénard flow with all fluid properties variable

NASA Astrophysics Data System (ADS)

Sassos, Athanasios; Pantokratoras, Asterios

2011-10-01

In the present paper, the effect of variable fluid properties (density, viscosity, thermal conductivity and specific heat) on the convection in the classical Rayleigh-Bénard problem is investigated. The investigation concerns water, air, and engine oil by taking into account the variation of fluid properties with temperature. The results are obtained by numerically solving the governing equations, using the SIMPLE algorithm and covering large temperature differences. It is found that the critical Rayleigh number increases as the temperature difference increases considering all fluid properties variable. However, when the fluid properties are kept constant, calculated at the mean temperature, and only density is considered variable, the critical Rayleigh number either decreases or remains constant.

Liquid level controller

DOEpatents

Mangus, J.D.; Redding, A.H.

1975-07-15

A system for maintaining two distinct sodium levels within the shell of a heat exchanger having a plurality of J-shaped modular tube bundles each enclosed in a separate shell which extends from a common base portion. A lower liquid level is maintained in the base portion and an upper liquid level is maintained in the shell enwrapping the long stem of the J-shaped tube bundles by utilizing standpipes with a notch at the lower end which decreases in open area the distance from the end of the stand pipe increases and a supply of inert gas fed at a constant rate to produce liquid levels, which will remain generally constant as the flow of liquid through the vessel varies. (auth)

On the classic and modern theories of matching.

PubMed

McDowell, J J

2005-07-01

Classic matching theory, which is based on Herrnstein's (1961) original matching equation and includes the well-known quantitative law of effect, is almost certainly false. The theory is logically inconsistent with known experimental findings, and experiments have shown that its central constant-k assumption is not tenable. Modern matching theory, which is based on the power function version of the original matching equation, remains tenable, although it has not been discussed or studied extensively. The modern theory is logically consistent with known experimental findings, it predicts the fact and details of the violation of the classic theory's constant-k assumption, and it accurately describes at least some data that are inconsistent with the classic theory.

Underwater radiation detector

DOEpatents

Kruse, Lyle W.; McKnight, Richard P.

1986-01-01

A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

Quantum Discord Preservation for Two Quantum-Correlated Qubits in Two Independent Reserviors

NASA Astrophysics Data System (ADS)

Xu, Lan

2018-03-01

We investigate the dynamics of quantum discord using an exactly solvable model where two qubits coupled to independent thermal environments. The quantum discord is employed as a non-classical correlation quantifier. By studying the quantum discord of a class of initial states, we find discord remains preserve for a finite time. The effects of the temperature, initial-state parameter, system-reservoir coupling constant and temperature difference parameter of the two independent reserviors are also investigated. We discover that the quantum nature loses faster in high temperature, however, one can extend the time of quantum nature by choosing smaller system-reservoir coupling constant, larger certain initial-state parameter and larger temperature difference parameter.

Symmetry Relations in Chemical Kinetics Arising from Microscopic Reversibility

NASA Astrophysics Data System (ADS)

Adib, Artur B.

2006-01-01

It is shown that the kinetics of time-reversible chemical reactions having the same equilibrium constant but different initial conditions are closely related to one another by a directly measurable symmetry relation analogous to chemical detailed balance. In contrast to detailed balance, however, this relation does not require knowledge of the elementary steps that underlie the reaction, and remains valid in regimes where the concept of rate constants is ill defined, such as at very short times and in the presence of low activation barriers. Numerical simulations of a model of isomerization in solution are provided to illustrate the symmetry under such conditions, and potential applications in protein folding or unfolding are pointed out.

Artifacts correction for T1rho imaging with constant amplitude spin-lock

NASA Astrophysics Data System (ADS)

Chen, Weitian

2017-01-01

T1rho imaging with constant amplitude spin-lock is prone to artifacts in the presence of B1 RF and B0 field inhomogeneity. Despite significant technological progress, improvements on the robustness of constant amplitude spin-lock are necessary in order to use it for routine clinical practice. This work proposes methods to simultaneously correct for B1 RF and B0 field inhomogeneity in constant amplitude spin-lock. By setting the maximum B1 amplitude of the excitation adiabatic pulses equal to the expected constant amplitude spin-lock frequency, the spins become aligned along the effective field throughout the spin-lock process. This results in T1rho-weighted images free of artifacts, despite the spatial variation of the effective field caused by B1 RF and B0 field inhomogeneity. When the pulse is long, the relaxation effect during the adiabatic half passage may result in a non-negligible error in the mono-exponential relaxation model. A two-acquisition approach is presented to solve this issue. Simulation, phantom, and in-vivo scans demonstrate the proposed methods achieve superior image quality compared to existing methods, and that the two-acquisition method is effective in resolving the relaxation effect during the adiabatic half passage.

Assessing Chemical Retention Process Controls in Ponds

NASA Astrophysics Data System (ADS)

Torgersen, T.; Branco, B.; John, B.

2002-05-01

Small ponds are a ubiquitous component of the landscape and have earned a reputation as effective chemical retention devices. The most common characterization of pond chemical retention is the retention coefficient, Ri= ([Ci]inflow-[Ci] outflow)/[Ci]inflow. However, this parameter varies widely in one pond with time and among ponds. We have re-evaluated literature reported (Borden et al., 1998) monthly average retention coefficients for two ponds in North Carolina. Employing a simple first order model that includes water residence time, the first order process responsible for species removal have been separated from the water residence time over which it acts. Assuming the rate constant for species removal is constant within the pond (arguable at least), the annual average rate constant for species removal is generated. Using the annual mean rate constant for species removal and monthly water residence times results in a significantly enhanced predictive capability for Davis Pond during most months of the year. Predictive ability remains poor in Davis Pond during winter/unstratified periods when internal loading of P and N results in low to negative chemical retention. Predictive ability for Piedmont Pond (which has numerous negative chemical retention periods) is improved but not to the same extent as Davis Pond. In Davis Pond, the rate constant for sediment removal (each month) is faster than the rate constant for water and explains the good predictability for sediment retention. However, the removal rate constant for P and N is slower than the removal rate constant for sediment (longer water column residence time for P,N than for sediment). Thus sedimentation is not an overall control on nutrient retention. Additionally, the removal rate constant for P is slower than for TOC (TOC is not the dominate removal process for P) and N is removed slower than P (different in pond controls). For Piedmont Pond, sediment removal rate constants are slower than the removal rate constant for water indicating significant sediment resuspension episodes. It appears that these sediment resuspension events are aperiodic and control the loading and the chemical retention capability of Piedmont Pond for N,P,TOC. These calculated rate constants reflect the differing internal loading processes for each component and suggest means and mechanisms for the use of ponds in water quality management.

Molecular structure of liquid alcohols

NASA Astrophysics Data System (ADS)

Huyskens, P.

1983-07-01

A new thermodynamic treatment of continuous association is presented, where the various equilibria between i-mers are replaced by a single equilibrium between an OH groups in the bonded and the non-bonded states, linked in both cases to an indefinite ensemble of molecules. The treatment leads to an association constant K which differs from those considered in the theories of Kretschmer and Wiebe and of Wiehe and Bagley. For pure alcohols the association constant can be estimated from the vapor pressure of the alcohol and that of the homomorphous hydrocarbon. The fraction γ of free OH groups determined in this way is markedly smaller than those calculated from the other theories. For the normal alcohols the product K VA is approximately constant at a given temperature, VA being the molar volume. This can be expected from the increasing of the standard entropy of the non-bonded molecules when the molecular volume increases. For secondary and tertiary alcohols the product K VA is significantly lower due to steric hindrances. However for all the alcohols considered here the enthalpy of the hydrogen bond remains nearly constant — δ H being equal to 24.8 ± 2 kJ mol -1.