Telemedicine in the management of chronic pain: a cost analysis study.

PubMed

Pronovost, Antoine; Peng, Philip; Kern, Ralph

2009-08-01

Telemedicine provides patients with easy and remote access to consultant expertise irrespective of geographic location. In a randomized controlled trial, this study has applied a rigorous costing methodology to the use of telemedicine in chronic pain management. We performed a randomized two-period crossover trial comparing in-person (IP) consultation with telemedicine (TM) consultation in the management of chronic pain. Over an 18-month period, 26 patients each completed two diaries capturing their direct and indirect travel costs, daily pain scores, and satisfaction with physician consultation. Costing models were developed to account for direct, indirect, fixed, and variable costs in order to perform break-even analyses. Sensitivity analysis was performed over a broad range of assumptions. Direct patient costs were significantly lower in the TM group than in the IP group, with median cost and interquartile range 133 dollars (28-377) vs 443 dollars (292-1075), respectively (P = 0.001). More patients were highly satisfied with the TM consultation than with the IP consultation (56 and 24%, respectively; P < 0.05). Break-even annual patient volume was estimated at 57 patients. A two-way sensitivity analysis controlling for annual patient volume and round-trip distance indicated that TM remains cost-effective at volumes >50 patients/year or at round-trip distances >200 km. Telemedicine is cost-effective over a broad range of assumptions, including annual patient volumes, travel distance, fuel costs, amortization, and discount rates. This study provides data from a real-world setting to determine relevant thresholds and targets for establishing a TM program for patients who are undergoing chronic pain therapy.

Diffractive Optics: Design, Fabrication, and Applications, Technical Digest Series, Volume 9, 1992

DTIC Science & Technology

1992-01-01

integration of optoelec- lens are presented and discussed. (p. 8) tronic chips with the passive glass optics. (p. 26) 10:00 am-10:30 am Coffee Break 2...optical pickup, Wai-Hon Lee, HOETRON, Inc. This paper discusses the recent pro- 3:30 pm-4:00 pm COFFEE BREAK gress in miniaturization of optical pickup...compared to 0th-order EMT and to 10:00 am-10:30 am COFFEE BREAK a rigorous coupled wave approach. (p. 44) 5:10 pm CABILDO ROOM MD4 Filter properties of

Variable-Temperature Cryostat For Radiation-Damage Testing Of Germanium Detectors

NASA Technical Reports Server (NTRS)

Floyd, Samuel R.; Puc, Bernard P.

1992-01-01

Variable-temperature cryostats developed to study radiation damage to, and annealing of, germanium gamma-ray detectors. Two styles: one accommodates large single detector and one accommodates two medium-sized detectors. New cryostats allow complete testing of large-volume germanium gamma-ray detectors without breaking cryostat vacuum and removing detectors for annealing.

Breaking Away from the Textbook, Volume I: Creative Ways to Teach World History Prehistory to 1600. Second Edition

ERIC Educational Resources Information Center

Pahl, Ron H.

2011-01-01

Teaching history should not be reciting an endless list of dead men, entombed between the covers of a textbook. Instead, "Breaking Away from the Textbook" offers a fascinating journey through world history. Not a comprehensive, theory-heavy guide, this book focuses on active classroom activities, methods for students to grapple with humanity's…

Modeling dam-break flows using finite volume method on unstructured grid

USDA-ARS?s Scientific Manuscript database

Two-dimensional shallow water models based on unstructured finite volume method and approximate Riemann solvers for computing the intercell fluxes have drawn growing attention because of their robustness, high adaptivity to complicated geometry and ability to simulate flows with mixed regimes and di...

Safety of working patterns among UK neuroradiologists: what can we learn from the aviation industry and cognitive science?

PubMed

Reicher, John; Currie, Stuart; Birchall, Daniel

2018-04-01

As the volume and complexity of imaging in the UK continues to rise, there is pressure on radiologists to spend increasing lengths of time reporting to cope with the growing workload. However, there is limited guidance for radiologists about structuring the working day to strike the necessary balance between achieving satisfactory reporting volume and maintaining quality and safety. We surveyed 86 neuroradiologists (receiving 59 responses), regarding time spent reporting, frequency and duration of work breaks, and break activities. Our results demonstrate that some neuroradiologists report for up to 12 h a day and for 4 h before taking a break. Mean duration of breaks is less than 15 min and these often consist of computer screen-based or cognitively demanding tasks. Many areas of medicine have looked to the aviation industry to develop improvements in safety through regulated, standardised practices. There are parallels between the work of air traffic controllers (ATCs) and radiologists. We review the legislation that controls the working hours of UK ATCs to minimise fatigue-related errors, and its scientific basis. We also consider the vigilance decrement, a concept in cognitive science which describes the reduction in performance with increasing time-on-task. We conclude that, in comparison with ATCs, work patterns among radiologists are poorly standardised and potentially dangerous. Evidence suggests that placing limits on reporting time and minimum break duration, as well as ensuring appropriate break activities, can benefit reporting quality. It is imperative that radiologists and managers heed these lessons, to improve standards and protect patients from error.

Future economic outlook of Nebraska rural community pharmacies based on break-even analysis of community operational costs and county population.

PubMed

Keast, Shellie L; Jacobs, Elgene; Harrison, Donald; Farmer, Kevin; Thompson, David

2010-09-01

There is growing concern over increasingly limited access to local health care, including pharmacies, for rural citizens of the United States. Although geographically distant from most competitors, rural pharmacies may still struggle to generate an acceptable profit to remain economically viable. Therefore, a method for calculating the economic viability for a community pharmacy to recruit a potential new owner to assume the entrepreneurial risk is an important issue to consider when evaluating rural pharmacy access. The primary objective of this study was to use a modified break-even analysis to predict the future financial potential of the current pharmacy business to attract a new owner. The secondary objective was to forecast a risk level for a Nebraska county to sustain the number of pharmacies in the country beyond current ownership. This research used data provided by pharmacies that responded to a Nebraska Medicaid cost of dispensing (COD) survey in addition to data from the US Census Bureau, US Office of Management and Budget, and the Nebraska State Board of Pharmacy. Break-even analysis was used to determine the point where the prescription volume of the pharmacy not only covered the variable and fixed costs but also maintained a reasonable profit to attract new ownership. Counties were classified into 3 risk levels based on the projected available prescription volume and the number of pharmacies in each county. Sensitivity analysis was performed on the risk levels to determine the impact of variance in projected available prescription volume on the projected future outlook for the pharmacies in each county. Regression analysis of responses to the COD survey indicated that the annual break-even prescription volume ranged from 44,790 to 49,246 prescriptions per pharmacy per annum. The number of rural Nebraska pharmacies was projected to decline from 126 to 78. The number of counties in Nebraska without a single pharmacy was projected to increase from 19 to 26, and the number of counties with just one pharmacy was projected to increase from 17 to 31. Thus, the number of counties with 1 or no pharmacy was projected to increase to 57 out of the total 93 Nebraska counties. The forecasted closure of pharmacies in rural areas will cause significant portions of the state to be without a pharmacy. Low county populations will be unable to sustain a local prescription volume large enough to remove them from the high risk of pharmacy closure. Copyright 2010 Elsevier Inc. All rights reserved.

High lung volume increases stress failure in pulmonary capillaries

NASA Technical Reports Server (NTRS)

Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

1992-01-01

We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological mechanism for other studies showing increased capillary permeability at high states of lung inflation.

SBLOCA outside containment at Browns Ferry Unit One. Volume 2. Iodine, cesium, and noble gas distribution and release

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

Wichner, R.P.; Weber, C.F.; Wright, A.L.

1983-09-01

This is the second volume of a two-part study regarding the response of Browns Ferry Unit 1 to a postulated break in the scram discharge volume of the control rod drive hydraulic system immediately following a scram. The material in this second volume pertains to the second aspect of the study, the resultant transport of fission products from their original locations in the fuel to a series of repositories within the primary system, the primary and secondary containment structures, and ultimately the release of a small portion to the environment. Transport models are developed for the noble gases krypton andmore » xenon and for iodine and cesium to describe the release of these fission products from the overheated fuel and their subsequent movement under the conditions predicted to exist in the various repositories during the course of the accident.« less

E-mail, decisional styles, and rest breaks.

PubMed

Baker, James R; Phillips, James G

2007-10-01

E-mail is a common but problematic work application. A scale was created to measure tendencies to use e-mail to take breaks (e-breaking); and self-esteem and decisional style (vigilance, procrastination, buck-passing, hypervigilance) were used to predict the self-reported and actual e-mail behaviors of 133 participants (students and marketing employees). Individuals who were low in defensive avoidance (buck-passing) engaged in more e-mailing per week, both in time spent on e-mail and message volume. E-breakers were more likely to engage in behavioral procrastination and spent more time on personal e-mail.

An Evaluation of Practical Applicability of Multi-Assortment Production Break-Even Analysis based on Mining Companies

NASA Astrophysics Data System (ADS)

Fuksa, Dariusz; Trzaskuś-Żak, Beata; Gałaś, Zdzisław; Utrata, Arkadiusz

2017-03-01

In the practice of mining companies, the vast majority of them produce more than one product. The analysis of the break-even, which is referred to as CVP (Cost-Volume-Profit) analysis (Wilkinson, 2005; Czopek, 2003) in their case is significantly constricted, given the necessity to include multi-assortment structure in the analysis, which may have more than 20 types of assortments (depending on the grain size) in their offer, as in the case of open-pit mines. The article presents methods of evaluation of break-even (volume and value) for both a single-assortment production and a multi-assortment production. The complexity of problem of break-even evaluation for multi-assortment production has resulted in formation of many methods, and, simultaneously, various approaches to its analysis, especially differences in accounting fixed costs, which may be either totally accounted for among particular assortments, relating to the whole company or partially accounted for among particular assortments and partially relating to the company, as a whole. The evaluation of the chosen methods of break-even analysis, given the availability of data, was based on two examples of mining companies: an open-pit mine of rock materials and an underground hard coal mine. The selection of methods was set by the available data provided by the companies. The data for the analysis comes from internal documentation of the mines - financial statements, breakdowns and cost calculations.

Ad libitum fluid consumption via self- or external administration.

PubMed

Yeargin, Susan W; Finn, Megan E; Eberman, Lindsey E; Gage, Matthew J; McDermott, Brendon P; Niemann, Andrew

2015-01-01

During team athletic events, athletic trainers commonly provide fluids with water bottles. When a limited number of water bottles exist, various techniques are used to deliver fluids. To determine whether fluid delivered via water-bottle administration influenced fluid consumption and hydration status. Crossover study. Outdoor field (22.2°C ± 3.5°C). Nineteen participants (14 men, 5 women, age = 30 ± 10 years, height = 176 ± 8 cm, mass = 72.5 ± 10 kg) were recruited from the university and local running clubs. The independent variable was fluid delivery with 3 levels: self-administration with mouth-to-bottle direct contact (SA-DC), self-administration with no contact between mouth and bottle (SA-NC), and external administration with no contact between the mouth and the bottle (EA-NC). Participants warmed up for 10 minutes before completing 5 exercise stations, after which an ad libitum fluid break was given, for a total of 6 breaks. We measured the fluid variables of total volume consumed, total number of squirts, and average volume per squirt. Hydration status via urine osmolality and body-mass loss, and perceptual variables for thirst and fullness were recorded. We calculated repeated-measures analyses of variance to assess hydration status, fluid variables, and perceptual measures to analyze conditions across time. The total volume consumed for EA-NC was lower than for SA-DC (P = .001) and SA-NC (P = .001). The total number of squirts for SA-DC was lower than for SA-NC (P = .009). The average volume per squirt for EA-NC was lower than for SA-DC (P = .020) and SA-NC (P = .009). Participants arrived (601.0 ± 21.3 mOsm/L) and remained (622.3 ± 38.3 mOsm/L) hydrated, with no difference between conditions (P = .544); however, the EA-NC condition lost more body mass than did the SA-DC condition (P = .001). There was no main effect for condition on thirst (P = .147) or fullness (P = .475). External administration of fluid decreased total volume consumed via a decreased average volume per squirt. The SA-DC method requires fewer squirts within a specific time frame. Fluid breaks every 15 minutes resulted in maintenance of euhydration; however, loss of body mass was influenced by fluid administration. Athletic trainers should avoid external administration to promote positive hydration behaviors. When fluid is self-administered, individual bottles may be the best clinical practice because more volume can be consumed per squirt.

Investigation of TiN thin film oxidation depending on the substrate temperature at vacuum break

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

Piallat, Fabien, E-mail: fabien.piallat@gmail.com; CEA, LETI, Campus Minatec, F-38054 Grenoble; LTM-CNRS, 17 rue des Martyrs, 38054 Grenoble

2016-09-15

Due to the reduction of the thickness of the layers used in the advanced technology nodes, there is a growing importance of the surface phenomena in the definition of the general properties of the materials. One of the least controlled and understood phenomenon is the oxidation of metals after deposition, at the vacuum break. In this study, the influence of the sample temperature at vacuum break on the oxidation level of TiN deposited by metalorganic chemical vapor deposition is investigated. TiN resistivity appears to be lower for samples which underwent vacuum break at high temperature. Using X-ray photoelectron spectrometry analysis,more » this change is correlated to the higher oxidation of the TiN layer. Moreover, angle resolved XPS analysis reveals that higher is the temperature at the vacuum break, higher is the surface oxidation of the sample. This surface oxidation is in turn limiting the diffusion of oxygen in the volume of the layer. Additionally, evolution of TiN layers resistivity was monitored in time and it shows that resistivity increases until a plateau is reached after about 10 days, with the lowest temperature at vacuum break resulting in the highest increase, i.e., the resistivity of the sample released to atmosphere at high temperature increased by a factor 1.7 whereas the resistivity of the sample cooled down under vacuum temperature increased by a factor 2.7.« less

European Conference on Advanced Materials and Processes Held in Aachen, Federal Republic of Germany on November 22-24, 1989

DTIC Science & Technology

1989-11-24

proceedings after the conference (the proceedings will consist of 3 volumes), extended abstracts, welcome reception, poster buffet, snack on Friday...poster buffet, snack on Friday, refreshments during official breaks. (This fee does not include the proceedings). " A limited number of registrations...buffet, snack on Friday, refreshments during the official breaks. (This fee does not include the proceedings). " Accompanying persons who are not

Development of a Pavement Maintenance Management System. Volume 9. Development of Airfield Pavement Performance Prediction Models.

DTIC Science & Technology

1984-05-01

materials, traffic, and climate, were used to develop PCI and key distress prediction models for both asphalt-concrete- and jointed-concrete- surfaced...Predicted PCI for PCC and AC/PCC Pavements Using Model Presented in Section III ...... 35 31 Effect of PCC Thickness on the PCI as a Function of Age...of Corner Breaking Observed vs Predicted Percent of Corner Breaking Using Model Presented in Section III

SU-E-T-05: Comparing DNA Strand Break Yields for Photons under Different Irradiation Conditions with Geant4-DNA.

PubMed

Pater, P; Bernal, M; Naqa, I El; Seuntjens, J

2012-06-01

To validate and scrutinize published DNA strand break data with Geant4-DNA and a probabilistic model. To study the impact of source size, electronic equilibrium and secondary electron tracking cutoff on direct relative biological effectiveness (DRBE). Geant4 (v4.9.5) was used to simulate a cylindrical region of interest (ROI) with r = 15 nm and length = 1.05 mm, in a slab of liquid water of 1.06 g/cm 3 density. The ROI was irradiated with mono-energetic photons, with a uniformly distributed volumetric isotropic source (0.28, 1.5 keV) or a plane beam (0.662, 1.25 MeV), of variable size. Electrons were tracked down to 50 or 10 eV, with G4-DNA processes and energy transfer greater than 10.79 eV was scored. Based on volume ratios, each scored event had a 0.0388 probability of happening on either DNA helix (break). Clusters of at least one break on each DNA helix within 3.4 nm were found using a DBSCAN algorithm and categorized as double strand breaks (DSB). All other events were categorized as single strand breaks (SSB). Geant4-DNA is able to reproduce strand break yields previously published. Homogeneous irradiation conditions should be present throughout the ROI for DRBE comparisons. SSB yields seem slightly dependent on the primary photon energy. DRBEs show a significant increasing trend for lower energy incident photons. A lower electron cutoff produces higher SSB yields, but decreases the SSB/DSB yields ratio. The probabilistic and geometrical DNA models can predict equivalent results. Using Geant4, we were able to reproduce previously published results on the direct strand break yields of photon and study the importance of irradiation conditions. We also show an ascending trend for DRBE with lower incident photon energies. A probabilistic model coupled with track structure analysis can be used to simulate strand break yields. NSERC, CIHR. © 2012 American Association of Physicists in Medicine.

The effect of viscoelasticity on the stress distribution of adhesively single-lap joint with an internal break in the composite adherends

NASA Astrophysics Data System (ADS)

Reza, Arash; Shishesaz, Mohammad

2017-09-01

The aim of this research is to study the effect of a break in the laminated composite adherends on stress distribution in the adhesively single-lap joint with viscoelastic adhesive and matrix. The proposed model involves two adherends with E-glass fibers and poly-methyl-methacrylate matrix that have been adhered to each other by phenolic-epoxy resin. The equilibrium equations that are based on shear-lag theory have been derived in the Laplace domain, and the governing differential equations of the model have been derived analytically in the Laplace domain. A numerical inverse Laplace transform, which is called Gaver-Stehfest method, has been used to extract desired results in the time domain. The results obtained at the initial time completely matched with the results of elastic solution. Also, a comparison between results obtained from the analytical and finite element models show a relatively good match. The results show that viscoelastic behavior decreases the peak of stress near the break. Finally, the effect of size and location of the break, as well as volume fraction of fibers, on the stress distribution in the adhesive layer is fully investigated.

A synthesis of the literature on breaking bad news or truth telling: potential for research in India.

PubMed

Martis, Lawrence; Westhues, Anne

2013-01-01

The high incidence of fatal diseases, inequitable access to health care, and socioeconomic disparities in India generate plentiful clinical bad news including diagnosis of a life-limiting disease, poor prognosis, treatment failure, and impending death. These contexts compel health care professionals to become the messengers of bad news to patients and their families. In global literature on breaking bad news, there is very little about such complex clinical interactions occurring in India or guiding health care providers to do it well. The purpose of this article is to identify the issues for future research that would contribute to the volume, comprehensiveness, and quality of empirical literature on breaking bad news in clinical settings across India. Towards this end, we have synthesized the studies done across the globe on breaking bad news, under four themes: (a) deciding the amount of bad news to deliver; (b) attending to cultural and ethical issues; (c) managing psychological distress; and (d) producing competent messengers of bad news. We believe that robust research is inevitable to build an indigenous knowledge base, enhance communicative competence among health care professionals, and thereby to improve the quality of clinical interactions in India.

A Synthesis of the Literature on Breaking Bad News or Truth Telling: Potential for Research in India

PubMed Central

Martis, Lawrence; Westhues, Anne

2013-01-01

The high incidence of fatal diseases, inequitable access to health care, and socioeconomic disparities in India generate plentiful clinical bad news including diagnosis of a life-limiting disease, poor prognosis, treatment failure, and impending death. These contexts compel health care professionals to become the messengers of bad news to patients and their families. In global literature on breaking bad news, there is very little about such complex clinical interactions occurring in India or guiding health care providers to do it well. The purpose of this article is to identify the issues for future research that would contribute to the volume, comprehensiveness, and quality of empirical literature on breaking bad news in clinical settings across India. Towards this end, we have synthesized the studies done across the globe on breaking bad news, under four themes: (a) deciding the amount of bad news to deliver; (b) attending to cultural and ethical issues; (c) managing psychological distress; and (d) producing competent messengers of bad news. We believe that robust research is inevitable to build an indigenous knowledge base, enhance communicative competence among health care professionals, and thereby to improve the quality of clinical interactions in India. PMID:23766589

Failure Analysis by Statistical Techniques (FAST). Volume 1. User’s Manual

DTIC Science & Technology

1974-10-31

REPORT NUMBER DNA 3336F-1 2. OOVT ACCESSION NO 4. TITLE Cand Sublllle) • FAILURE ANALYSIS BY STATISTICAL TECHNIQUES (FAST) Volume I, User’s...SS2), and t’ a facility ( SS7 ). The other three diagrams break down the three critical subsystems. T le median probability of survival of the

A novel solution blending method for using olive oil and corn oil as plasticizers in chitosan based organoclay nanocomposites.

PubMed

Giannakas, A; Patsaoura, A; Barkoula, N-M; Ladavos, A

2017-02-10

In the current study a novel reflux-solution blending method is being followed with the introduction of small ethanol volumes into chitosan acetic acid aquatic solution in order to incorporate olive oil and corn oil in chitosan and its organoclay nanocomposites. Ethanol enables the direct interaction of chitosan with oils and results in effective plasticization of chitosan/oil films with remarkable increase of the strain at break from 8% of chitosan and chitosan/oil aquatic samples to app. 22% for chitosan/oil ethanol samples. Compared with olive oil, corn oil is less effective as plasticizer (max strain at break app. 14%). Addition of oils is beneficial for water sorption, water vapor permeability and oxygen permeability response of the obtained films. Barrier properties are further improved after the use of OrgMMT, however OrgMMT results in significant reduction of strain at break of all oil containing samples (app. 8%) acting as stress concentrator upon deformation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of Water-Oil Emulsion Breaking by Stabilized Solution Consisting of Anionic Surface Acting Agent - Soda Ash - Polymer (ASP)

NASA Astrophysics Data System (ADS)

Kulichkov, S. V.; Avtomonov, E. G.; Andreeva, L. V.; Solomennik, S. F.; Nikitina, A. V.

2018-01-01

The paper provides a laboratory research of breaking natural water-oil emulsions: - by non-stabilized ASP; by stabilized ASP; by mixture of stabilized and non-stabilized ASP in different proportions and production of refinery water of the required quality with the use of IronGuard 2495 as flocculant. Oil-in-water emulsion is stable. Classic methods are not suitable for residual water treatment: sediment gravity flow; filtration; centrifuge test. Microemulsion formed after ASP application has low boundary tension and high pH. It contributes to transfer of oil phase into a water one, forming oil-in-water emulsion. Alkaline condition has adverse effect on demulsifying ability of agents, flocculation and boundary tension. For breaking of water-oil emulsion at EBU before the interchanger water or water-oil emulsion from the wells that were not APS-treated in ratio of 1:9 shall be delivered. Residual water after EBU must be prepared in water tanks by dilution in great volume.

Sustainable Cost Models for mHealth at Scale: Modeling Program Data from m4RH Tanzania.

PubMed

Mangone, Emily R; Agarwal, Smisha; L'Engle, Kelly; Lasway, Christine; Zan, Trinity; van Beijma, Hajo; Orkis, Jennifer; Karam, Robert

2016-01-01

There is increasing evidence that mobile phone health interventions ("mHealth") can improve health behaviors and outcomes and are critically important in low-resource, low-access settings. However, the majority of mHealth programs in developing countries fail to reach scale. One reason may be the challenge of developing financially sustainable programs. The goal of this paper is to explore strategies for mHealth program sustainability and develop cost-recovery models for program implementers using 2014 operational program data from Mobile for Reproductive Health (m4RH), a national text-message (SMS) based health communication service in Tanzania. We delineated 2014 m4RH program costs and considered three strategies for cost-recovery for the m4RH program: user pay-for-service, SMS cost reduction, and strategic partnerships. These inputs were used to develop four different cost-recovery scenarios. The four scenarios leveraged strategic partnerships to reduce per-SMS program costs and create per-SMS program revenue and varied the structure for user financial contribution. Finally, we conducted break-even and uncertainty analyses to evaluate the costs and revenues of these models at the 2014 user volume (125,320) and at any possible break-even volume. In three of four scenarios, costs exceeded revenue by $94,596, $34,443, and $84,571 at the 2014 user volume. However, these costs represented large reductions (54%, 83%, and 58%, respectively) from the 2014 program cost of $203,475. Scenario four, in which the lowest per-SMS rate ($0.01 per SMS) was negotiated and users paid for all m4RH SMS sent or received, achieved a $5,660 profit at the 2014 user volume. A Monte Carlo uncertainty analysis demonstrated that break-even points were driven by user volume rather than variations in program costs. These results reveal that breaking even was only probable when all SMS costs were transferred to users and the lowest per-SMS cost was negotiated with telecom partners. While this strategy was sustainable for the implementer, a central concern is that health information may not reach those who are too poor to pay, limiting the program's reach and impact. Incorporating strategies presented here may make mHealth programs more appealing to funders and investors but need further consideration to balance sustainability, scale, and impact.

Sustainable Cost Models for mHealth at Scale: Modeling Program Data from m4RH Tanzania

PubMed Central

Mangone, Emily R.; Agarwal, Smisha; L’Engle, Kelly; Lasway, Christine; Zan, Trinity; van Beijma, Hajo; Orkis, Jennifer; Karam, Robert

2016-01-01

Background There is increasing evidence that mobile phone health interventions (“mHealth”) can improve health behaviors and outcomes and are critically important in low-resource, low-access settings. However, the majority of mHealth programs in developing countries fail to reach scale. One reason may be the challenge of developing financially sustainable programs. The goal of this paper is to explore strategies for mHealth program sustainability and develop cost-recovery models for program implementers using 2014 operational program data from Mobile for Reproductive Health (m4RH), a national text-message (SMS) based health communication service in Tanzania. Methods We delineated 2014 m4RH program costs and considered three strategies for cost-recovery for the m4RH program: user pay-for-service, SMS cost reduction, and strategic partnerships. These inputs were used to develop four different cost-recovery scenarios. The four scenarios leveraged strategic partnerships to reduce per-SMS program costs and create per-SMS program revenue and varied the structure for user financial contribution. Finally, we conducted break-even and uncertainty analyses to evaluate the costs and revenues of these models at the 2014 user volume (125,320) and at any possible break-even volume. Results In three of four scenarios, costs exceeded revenue by $94,596, $34,443, and $84,571 at the 2014 user volume. However, these costs represented large reductions (54%, 83%, and 58%, respectively) from the 2014 program cost of $203,475. Scenario four, in which the lowest per-SMS rate ($0.01 per SMS) was negotiated and users paid for all m4RH SMS sent or received, achieved a $5,660 profit at the 2014 user volume. A Monte Carlo uncertainty analysis demonstrated that break-even points were driven by user volume rather than variations in program costs. Conclusions These results reveal that breaking even was only probable when all SMS costs were transferred to users and the lowest per-SMS cost was negotiated with telecom partners. While this strategy was sustainable for the implementer, a central concern is that health information may not reach those who are too poor to pay, limiting the program’s reach and impact. Incorporating strategies presented here may make mHealth programs more appealing to funders and investors but need further consideration to balance sustainability, scale, and impact. PMID:26824747

Spontaneous breaking of discrete symmetries in QCD on a small volume

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

Lucini, B.; Patella, A.; Pica, C.

2007-11-20

In a compact space with non-trivial cycles, for sufficiently small values of the compact dimensions, charge conjugation (C), spatial reflection (P) and time reversal (J) are spontaneously broken in QCD. The order parameter for the symmetry breaking is the trace of the Wilson line wrapping around the compact dimension, which acquires an imaginary part in the broken phase. We show that a physical signature for the symmetry breaking is a persistent baryonic current wrapping in the compact directions. The existence of such a current is derived analytically at first order in perturbation theory and confirmed in the non-perturbative regime bymore » lattice simulations.« less

Break-even analysis revisited: the need to adjust for profitability, the collection rate and autonomous income.

PubMed

Broyles, R W; Narine, L; Khaliq, A

2003-08-01

This paper modifies traditional break-even analysis and develops a model that reflects the influence of variation in payer mix, the collection rate, profitability and autonomous income on the desired volume alternative. The augmented model indicates that a failure to adjust for uncollectibles and the net surplus results in a systematic understatement of the desired volume alternative. Conversely, a failure to adjust for autonomous income derived from the operation of cafeterias, gift shops or an organization's investment in marketable securities produces an overstatement of the desired volume. In addition, this paper uses Microsoft Excel to develop a spreadsheet that constructs a pro forma income statement, expressed in terms of the contribution margin. The spreadsheet also relies on the percentage of sales or revenue approach to prepare a balance sheet from which indicators of fiscal performance are calculated. Hence, the analysis enables the organization to perform a sensitivity analysis of potential changes in the desired volume, the operating margin, the current ratio, the debt: equity ratio and the amount of cash derived from operations that are associated with expected variation in payer mix, the collection rate, grouped by payer, the net surplus and autonomous income.

Numerical solution of the Saint-Venant equations by an efficient hybrid finite-volume/finite-difference method

NASA Astrophysics Data System (ADS)

Lai, Wencong; Khan, Abdul A.

2018-04-01

A computationally efficient hybrid finite-volume/finite-difference method is proposed for the numerical solution of Saint-Venant equations in one-dimensional open channel flows. The method adopts a mass-conservative finite volume discretization for the continuity equation and a semi-implicit finite difference discretization for the dynamic-wave momentum equation. The spatial discretization of the convective flux term in the momentum equation employs an upwind scheme and the water-surface gradient term is discretized using three different schemes. The performance of the numerical method is investigated in terms of efficiency and accuracy using various examples, including steady flow over a bump, dam-break flow over wet and dry downstream channels, wetting and drying in a parabolic bowl, and dam-break floods in laboratory physical models. Numerical solutions from the hybrid method are compared with solutions from a finite volume method along with analytic solutions or experimental measurements. Comparisons demonstrates that the hybrid method is efficient, accurate, and robust in modeling various flow scenarios, including subcritical, supercritical, and transcritical flows. In this method, the QUICK scheme for the surface slope discretization is more accurate and less diffusive than the center difference and the weighted average schemes.

An Application of Cartesian-Grid and Volume-of-Fluid Methods to Numerical Ship Hydrodynamics

DTIC Science & Technology

2007-10-01

water-particle ve- locity is discontinuous across the air-water interface, and where CiEA is the Levi - Civita function. rj is the moment the vertical...methods and volume-of- immersed- body and volume-of-fluid (VOF) methods. fluid methods is used to simulate breaking waves around The governing equations are...of a ship hull is used as input to automat- body -fitted grids. The sole geometric input into NFA ically generate an immersed-boundary representation of

Studies in Intelligence. Volume 55, Number 3

DTIC Science & Technology

2011-09-01

hearing, Director of National Intelligence (DNI) James R. Clapper noted the need for a single repository of terrorism- related data as a foundation...A CIA Memoir by Stuart Methven The Making And Breaking Of An American Spy, by James Everett Intelligence Abroad Ashraf Marwan, Israel’s Most Valuable...Bureau cases. He includes bio - graphical details about special agents and illu- minates the often frustrating bureaucratic culture in which they

Breaking through the uncertainty ceiling in LA-ICP-MS U-Pb geochronology

NASA Astrophysics Data System (ADS)

Horstwood, M.

2016-12-01

Sources of systematic uncertainty associated with session-to-session bias are the dominant contributor to the 2% (2s) uncertainty ceiling that currently limits the accuracy of LA-ICP-MS U-Pb geochronology. Sources include differential downhole fractionation (LIEF), `matrix effects' and ablation volume differences, which result in irreproducibility of the same reference material across sessions. Current mitigation methods include correcting for LIEF mathematically, using matrix-matched reference materials, annealing material to reduce or eliminate radiation damage effects and tuning for robust plasma conditions. Reducing the depth and volume of ablation can also mitigate these problems and should contribute to the reduction of the uncertainty ceiling. Reducing analysed volume leads to increased detection efficiency, reduced matrix-effects, eliminates LIEF, obviates ablation rate differences and reduces the likelihood of intercepting complex growth zones with depth, thereby apparently improving material homogeneity. High detection efficiencies (% level) and low sampling volumes (20um box, 1-2um deep) can now be achieved using MC-ICP-MS such that low volume ablations should be considered part of the toolbox of methods targeted at improving the reproducibility of LA-ICP-MS U-Pb geochronology. In combination with other strategies these improvements should be feasible on any ICP platform. However, reducing the volume of analysis reduces detected counts and requires a change of analytical approach in order to mitigate this. Appropriate strategies may include the use of high efficiency cell and torch technologies and the optimisation of acquisition protocols and data handling techniques such as condensing signal peaks, using log ratios and total signal integration. The tools required to break the 2% (2s) uncertainty ceiling in LA-ICP-MS U-Pb geochronology are likely now known but require a coherent strategy and change of approach to combine their implementation and realise this goal. This study will highlight these changes and efforts towards reducing the uncertainty contribution for LA-ICP-MS U-Pb geochronology.

Accelerometer-Derived Pattern of Sedentary and Physical Activity Time in Persons with Mobility Disability: National Health and Nutrition Examination Survey 2003 to 2006.

PubMed

Manns, Patricia; Ezeugwu, Victor; Armijo-Olivo, Susan; Vallance, Jeff; Healy, Genevieve N

2015-07-01

To describe objectively determined sedentary and activity outcomes (volume and pattern) and their associations with cardiometabolic risk biomarkers in individuals with and without mobility disability. Cross-sectional. Population based. Community-dwelling older adults (≥60) living in the United States who were participants in the 2003 to 2004 or 2005 to 2006 National Health and Nutrition Examination Survey. Participants were classified as with or without mobility disability according to responses to self-reported questions about ability to walk, climb stairs, and/or use of ambulatory aids. Accelerometer-derived sedentary and activity variables for volume (time in sedentary (<100 counts per minute (cpm)), very light- (100-759 cpm), light- (760-1,951 cpm), and moderate- to vigorous- (≥1,952 cpm) intensity activity and pattern (number of breaks from sedentary time, duration of sedentary bouts, duration of activity bouts). Survey-weighted regression models, adjusted for age, sex, ethnicity, education, and smoking, were used to examine the associations between pattern of activity and cardiometabolic health risk factors (blood pressure, waist circumference, high-density lipoprotein cholesterol). Of the 2,017 participants, 547 were classified as having a mobility disability. Participants with mobility disability had more sedentary time and less active time than those without. Sedentary bouts were longer and active bouts shorter in those with disability. The total number of sedentary breaks (transitions from sedentary to nonsedentary) differed between groups after adjustment for total sedentary time. Fewer breaks, longer sedentary bouts, and shorter activity bouts were associated with higher average waist circumference regardless of disability status. This study provides rationale for the development and testing of interventions to change the pattern of activity (e.g., include more breaks and longer activity bout durations) in older adults with mobility disability. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Simulation of the Formation of DNA Double Strand Breaks and Chromosome Aberrations in Irradiated Cells

NASA Technical Reports Server (NTRS)

Plante, Ianik; Ponomarev, Artem L.; Wu, Honglu; Blattnig, Steve; George, Kerry

2014-01-01

The formation of DNA double-strand breaks (DSBs) and chromosome aberrations is an important consequence of ionizing radiation. To simulate DNA double-strand breaks and the formation of chromosome aberrations, we have recently merged the codes RITRACKS (Relativistic Ion Tracks) and NASARTI (NASA Radiation Track Image). The program RITRACKS is a stochastic code developed to simulate detailed event-by-event radiation track structure: [1] This code is used to calculate the dose in voxels of 20 nm, in a volume containing simulated chromosomes, [2] The number of tracks in the volume is calculated for each simulation by sampling a Poisson distribution, with the distribution parameter obtained from the irradiation dose, ion type and energy. The program NASARTI generates the chromosomes present in a cell nucleus by random walks of 20 nm, corresponding to the size of the dose voxels, [3] The generated chromosomes are located within domains which may intertwine, and [4] Each segment of the random walks corresponds to approx. 2,000 DNA base pairs. NASARTI uses pre-calculated dose at each voxel to calculate the probability of DNA damage at each random walk segment. Using the location of double-strand breaks, possible rejoining between damaged segments is evaluated. This yields various types of chromosomes aberrations, including deletions, inversions, exchanges, etc. By performing the calculations using various types of radiations, it will be possible to obtain relative biological effectiveness (RBE) values for several types of chromosome aberrations.

SEASAT economic assessment. Volume 6: Arctic operations case study and generalization. [economic benefits of SEASAT satellites to oil exploration in the Arctic

NASA Technical Reports Server (NTRS)

1975-01-01

The hypothetical development and transportation of Arctic oil and other resources by ice breaking super tanker fleets to the continental East Coast are discussed. The utilization of SEASAT ice mapping data is shown to contribute to a more effective transportation operation through the Arctic ice by reducing transportation costs as a consequence of reduced transit time per voyage.

Changes in Tear Volume after 3% Diquafosol Treatment in Patients with Dry Eye Syndrome: An Anterior Segment Spectral-domain Optical Coherence Tomography Study.

PubMed

Lee, Kwan Bok; Koh, Kyung Min; Kwon, Young A; Song, Sang Wroul; Kim, Byoung Yeop; Chung, Jae Lim

2017-08-01

To evaluate changes in the tear meniscus area and tear meniscus height over time in patients with dry eye syndrome, using anterior segment spectral-domain optical coherence tomography after the instillation of 3% diquafosol ophthalmic solution. Sixty eyes from 30 patients with mild to moderate dry eye syndrome were included. Tear meniscus images acquired by anterior segment spectral-domain optical coherence tomography were analyzed using National Institutes of Health's image-analysis software (ImageJ 1.44p). Tear meniscus area and tear meniscus height were measured at baseline, 5 minutes, 10 minutes, and 30 minutes after instillation of a drop of diquafosol in one eye and normal saline in the other eye. Changes in ocular surface disease index score, tear film break-up time, corneal staining score by Oxford schema, and meibomian expressibility were also evaluated at baseline, and after 1 week and 1 month of a diquafosol daily regimen. Sixty eyes from 30 subjects (mean age, 29.3 years; 8 men and 22 women) were included. In eyes receiving diquafosol, tear volume was increased at 5 and 10 minutes compared with baseline. It was also higher than saline instilled eyes at 5, 10, and 30 minutes. Changes in tear volume with respect to baseline were not statistically different after the use of diquafosol for 1 month. Ocular surface disease index score, tear film break-up time, and Oxford cornea stain score were significantly improved after 1 week and 1 month of daily diquafosol instillation, but meibomian expressibility did not change. Topical diquafosol ophthalmic solution effectively increased tear volume for up to 30 minutes, compared to normal saline in patients with dry eye syndrome. © 2017 The Korean Ophthalmological Society

Toward de Sitter space from ten dimensions

NASA Astrophysics Data System (ADS)

Moritz, Jakob; Retolaza, Ander; Westphal, Alexander

2018-02-01

Using a 10D lift of nonperturbative volume stabilization in type IIB string theory, we study the limitations for obtaining de Sitter vacua. Based on this we find that the simplest Kachru, Kallosh, Linde, and Trivedi vacua with a single Kähler modulus stabilized by a gaugino condensate cannot be uplifted to de Sitter. Rather, the uplift flattens out due to stronger backreaction on the volume modulus than has previously been anticipated, resulting in vacua which are metastable and supersymmetry breaking, but that are always anti-de Sitter (AdS). However, we also show that setups such as racetrack stabilization can avoid this issue. In these models it is possible to obtain supersymmetric AdS vacua with a cosmological constant that can be tuned to zero while retaining finite moduli stabilization. In this regime, it seems that de Sitter uplifts are possible with negligible backreaction on the internal volume. We exhibit this behavior also from the 10D perspective.

Nonlinear interaction and wave breaking with a submerged porous structure

NASA Astrophysics Data System (ADS)

Hsieh, Chih-Min; Sau, Amalendu; Hwang, Robert R.; Yang, W. C.

2016-12-01

Numerical simulations are performed to investigate interactive velocity, streamline, turbulent kinetic energy, and vorticity perturbations in the near-field of a submerged offshore porous triangular structure, as Stokes waves of different heights pass through. The wave-structure interaction and free-surface breaking for the investigated flow situations are established based on solutions of 2D Reynolds Averaged Navier-Stokes equations in a Cartesian grid in combination with K-ɛ turbulent closure and the volume of fluid methodology. The accuracy and stability of the adopted model are ascertained by extensive comparisons of computed data with the existing experimental and theoretical findings and through efficient predictions of the internal physical kinetics. Simulations unfold "clockwise" and "anticlockwise" rotation of fluid below the trough and the crest of the viscous waves, and the penetrated wave energy creates systematic flow perturbation in the porous body. The interfacial growths of the turbulent kinetic energy and the vorticity appear phenomenal, around the apex of the immersed structure, and enhanced significantly following wave breaking. Different values of porosity parameter and two non-porous cases have been examined in combination with varied incident wave height to reveal/analyze the nonlinear flow behavior in regard to local spectral amplification and phase-plane signatures. The evolution of leading harmonics of the undulating free-surface and the vertical velocity exhibits dominating roles of the first and the second modes in inducing the nonlinearity in the post-breaking near-field that penetrates well below the surface layer. The study further suggests the existence of a critical porosity that can substantially enhance the wave-shoaling and interface breaking.

Effects of viscosity and volume on the patterns of esophageal motility in healthy adults using high-resolution manometry.

PubMed

Park, J H; Lee, H; Rhee, P-L; Park, J H

2015-01-01

The purpose of this study was to determine the effects of age, sex, body mass index (BMI), viscosity, and volume on esophageal motility using high-resolution manometry (HRM). Manometric studies were performed on 60 asymptomatic volunteers (27 men and 33 women, age: 19-56 years) while in a supine position. Manometric protocol included 10 water swallows (5 cc), 10 jelly swallows (5 cc), and 1 water swallow (20 cc). Evaluation of HRM parameters including length of proximal pressure trough (PPT length), distal latency (DL), contractile front velocity (CFV), distal contractile integral (DCI), and 4-second integrated relaxation pressure (IRP) was performed using MATLAB. Significant differences were noted in median IRP between water 5 cc (median 7.2 mmHg [range 5.5-9.6]), jelly 5 cc (median 6.0 mmHg [range 3.8-8.0]), and water 20 cc {(Median 4.8 mmHg [range 3.3-7.4]), P < 0.01}. DL were significantly different between water 5 cc, jelly 5 cc, and water 20 cc (P < 0.01), and in terms of PPT, proportions of small (2 cm ≤ < 5 cm) and large (5 cm≤) break for jelly 5 cc were significantly higher than those for the water 5 cc swallow (P < 0.05). Furthermore, DCI increased with age for water 5 cc, and a significant negative correlation was noticed between proportions of small break and BMI for water 5 cc. Manometric measurements vary depending on age, BMI, viscosity, and volume. These findings need to be taken into account in the interpretation of manometry results. © 2014 International Society for Diseases of the Esophagus.

Chinese-English Rocketry Dictionary. Volume 2

DTIC Science & Technology

1978-02-01

dissection; dissect jiesan • break up; peel off; disperse; dismiss; dissolve jieshi explan.ation; explain; interpretation; exposition jieshi chengxu...integral pulse-height 20fenbu distribution maichong baoxien f , jp pulse envelope 21 maichong banna I 4 I 1 impulse coding 22 maichong bianrs

A Study of ATLAS Grid Performance for Distributed Analysis

NASA Astrophysics Data System (ADS)

Panitkin, Sergey; Fine, Valery; Wenaus, Torre

2012-12-01

In the past two years the ATLAS Collaboration at the LHC has collected a large volume of data and published a number of ground breaking papers. The Grid-based ATLAS distributed computing infrastructure played a crucial role in enabling timely analysis of the data. We will present a study of the performance and usage of the ATLAS Grid as platform for physics analysis in 2011. This includes studies of general properties as well as timing properties of user jobs (wait time, run time, etc). These studies are based on mining of data archived by the PanDA workload management system.

A numerical study of granular dam-break flow

NASA Astrophysics Data System (ADS)

Pophet, N.; Rébillout, L.; Ozeren, Y.; Altinakar, M.

2017-12-01

Accurate prediction of granular flow behavior is essential to optimize mitigation measures for hazardous natural granular flows such as landslides, debris flows and tailings-dam break flows. So far, most successful models for these types of flows focus on either pure granular flows or flows of saturated grain-fluid mixtures by employing a constant friction model or more complex rheological models. These saturated models often produce non-physical result when they are applied to simulate flows of partially saturated mixtures. Therefore, more advanced models are needed. A numerical model was developed for granular flow employing a constant friction and μ(I) rheology (Jop et al., J. Fluid Mech. 2005) coupled with a groundwater flow model for seepage flow. The granular flow is simulated by solving a mixture model using Finite Volume Method (FVM). The Volume-of-Fluid (VOF) technique is used to capture the free surface motion. The constant friction and μ(I) rheological models are incorporated in the mixture model. The seepage flow is modeled by solving Richards equation. A framework is developed to couple these two solvers in OpenFOAM. The model was validated and tested by reproducing laboratory experiments of partially and fully channelized dam-break flows of dry and initially saturated granular material. To obtain appropriate parameters for rheological models, a series of simulations with different sets of rheological parameters is performed. The simulation results obtained from constant friction and μ(I) rheological models are compared with laboratory experiments for granular free surface interface, front position and velocity field during the flows. The numerical predictions indicate that the proposed model is promising in predicting dynamics of the flow and deposition process. The proposed model may provide more reliable insight than the previous assumed saturated mixture model, when saturated and partially saturated portions of granular mixture co-exist.

The effect of paleotopography on lithic distribution and facies associations of small volume ignimbrites: the WTT Cupa (Roccamonfina volcano, Italy)

NASA Astrophysics Data System (ADS)

Giordano, Guido

1998-12-01

The distribution of lithic clasts within two trachytic, small volume, pumiceous ignimbrites are described from the Quaternary `White Trachytic Tuff Cupa' formation of Roccamonfina volcano, Italy. The ignimbrites show a downslope grading of lithics, with a maximum size where there is a major break in the volcano's slope, rather than at proximal locations. This is also the location where ignimbrites are thickest and most massive. The break in slope is interpreted to have reduced flow capacity and velocity, increasing the sedimentation rate, so that massive ignimbrite formed by hindered settling sedimentation. Ignimbrite Cc, exhibits no vertical grading of lithics, though it does show downslope grading with maximum size at the major break in slope and a rapid decrease further downslope. Ignimbrite Cc thins away from the break in slope, and shows an upward fining of the grain size within the topmost few decimeters of the unit. The ignimbrite is stratified proximally, and grades to massive facies at the break in slope, and distally to stratified facies with numerous inverse-graded beds. The simplest mechanism accounting for these downslope variations is progressive aggradation from a quasi-steady, nonuniform pyroclastic density current. The changes in deposit thickness and facies are interpreted to record downcurrent changes in sedimentation rate. The upward fining reflects waning flow. Inversely graded, bedded depositional facies in distal areas is interpreted to reflect flow unsteadiness and a decrease in suspended sediment load. Ignimbrite Cd shows vertical, as well as downslope grading of lithics. This characteristic, coupled with the widespread massive facies of the deposit and the tabular unit geometry are features that can be reconciled with both the debris flow/plug analogy for pyroclastic flows ( Sparks, 1976) and the progressive aggradation model ( Branney and Kokelaar, 1992). However, none of them appears to satisfy completely the field evidences, implying that when dealing with massive ignimbrites, other evidence than lithic grading needs to be presented to better understand the related transport and depositional processes.

CASIMIR Effect in a Supersymmetry-Breaking Brane-World as Dark Energy

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

Chen, P

2004-09-29

A new model for the origin of dark energy is proposed based on the Casimir effect in a supersymmetry-breaking brane-world. Supersymmetry is assumed to be preserved in the bulk while broken on a 3-brane. Due to the boundary conditions imposed on the compactified extra dimensions, there is an effective Casimir energy induced on the brane. The net Casimir energy contributed from the graviton and the gravitino modes as a result of supersymmetry-breaking on the brane is identified as the observed dark energy, which in our construction is a cosmological constant. We show that the smallness of the cosmological constant, whichmore » results from the huge contrast in the extra-dimensional volumes between that associated with the 3-brane and that of the bulk, is attainable under very relaxed condition.« less

THREE-DIMENSIONAL MODELING OF THE DYNAMICS OF THERAPEUTIC ULTRASOUND CONTRAST AGENTS

PubMed Central

Hsiao, Chao-Tsung; Lu, Xiaozhen; Chahine, Georges

2010-01-01

A 3-D thick-shell contrast agent dynamics model was developed by coupling a finite volume Navier-Stokes solver and a potential boundary element method flow solver to simulate the dynamics of thick-shelled contrast agents subjected to pressure waves. The 3-D model was validated using a spherical thick-shell model validated by experimental observations. We then used this model to study shell break-up during nonspherical deformations resulting from multiple contrast agent interaction or the presence of a nearby solid wall. Our simulations indicate that the thick viscous shell resists the contrast agent from forming a re-entrant jet, as normally observed for an air bubble oscillating near a solid wall. Instead, the shell thickness varies significantly from location to location during the dynamics, and this could lead to shell break-up caused by local shell thinning and stretching. PMID:20950929

Large Igneous Provinces, Mantle Plumes, and Continental Break-up: An Overview.

NASA Astrophysics Data System (ADS)

Peate, D. W.

2003-04-01

Although mantle plumes are widely implicated in models for the generation of large igneous provinces (LIPs) and the break-up of supercontinents such as Gondwana, the exact role of the mantle plume in these processes, and even the very existence of mantle plumes, is controversial and hotly debated. The large volumes of magma produced within a LIP (> 10^6 km^3) in a relative short time interval (< few Myrs) require elevated mantle temperatures such as is inferred for a plume, but it is not easy to determine whether the melting occurred as a result of the arrival of a plume head in the shallow mantle or in response to lithospheric extension. Numerous questions remain unresolved: e.g. Can all LIPs be explained by plume-like mantle upwellings, or are non-plume models such as edge-driven convection a plausible alternative?; Are plumes wet-spots rather than hot-spots?; Do they originate from the core-mantle boundary?; How important is the influence of the overlying lithosphere (limiting the upwelling and extent of melting, modifying the composition of deeper melts, and possibly acting as a source for melts)? In this presentation, I will summarise key observations from three young LIP's (< 135 Ma), each associated with continental break-up. These case studies will be: (i) North Atlantic LIP - Iceland plume, (ii) Parana-Etendeka LIP - Tristan plume, and (iii) Ethiopia-Yemen LIP - Afar plume. Aspects that will be considered include: the areal extent, volume and eruption rates of magmatism; temporal relationship of flood basalt volcanism to lithospheric extension and continental break-up; compositional similarities and differences between the flood basalts and more recent lavas from the associated plume; spatial and temporal compositional variations as a means of assessing the location and length-scales of heterogeneities in the upwelling mantle, seismic tomographic images of mantle thermal structure today; crustal structure of the rifted margins from wide-angle and reflection seismic data. These geochemical, tectonic, and geophysical observations will then be used to evaluate the role of a plume in the formation of each of the three LIP's.

Antarctic icebergs distributions 1992-2014

NASA Astrophysics Data System (ADS)

Tournadre, J.; Bouhier, N.; Girard-Ardhuin, F.; Rémy, F.

2016-01-01

Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs (>100 km2) transport most of the ice volume but their basal melting is small compared to their breaking into smaller icebergs that constitute thus the major vector of freshwater. The archives of nine altimeters have been processed to create a database of small icebergs (<8 km2) within open water containing the positions, sizes, and volumes spanning the 1992-2014 period. The intercalibrated monthly ice volumes from the different altimeters have been merged in a homogeneous 23 year climatology. The iceberg size distribution, covering the 0.1-10,000 km2 range, estimated by combining small and large icebergs size measurements follows well a power law of slope -1.52 ± 0.32 close to the -3/2 laws observed and modeled for brittle fragmentation. The global volume of ice and its distribution between the ocean basins present a very strong interannual variability only partially explained by the number of large icebergs. Indeed, vast zones of the Southern Ocean free of large icebergs are largely populated by small iceberg drifting over thousands of kilometers. The correlation between the global small and large icebergs volumes shows that small icebergs are mainly generated by large ones breaking. Drifting and trapping by sea ice can transport small icebergs for long period and distances. Small icebergs act as an ice diffuse process along large icebergs trajectories while sea ice trapping acts as a buffer delaying melting.

Response of jammed packings to thermal fluctuations

NASA Astrophysics Data System (ADS)

Wu, Qikai; Bertrand, Thibault; Shattuck, Mark D.; O'Hern, Corey S.

2017-12-01

We focus on the response of mechanically stable (MS) packings of frictionless, bidisperse disks to thermal fluctuations, with the aim of quantifying how nonlinearities affect system properties at finite temperature. In contrast, numerous prior studies characterized the structural and mechanical properties of MS packings of frictionless spherical particles at zero temperature. Packings of disks with purely repulsive contact interactions possess two main types of nonlinearities, one from the form of the interaction potential (e.g., either linear or Hertzian spring interactions) and one from the breaking (or forming) of interparticle contacts. To identify the temperature regime at which the contact-breaking nonlinearities begin to contribute, we first calculated the minimum temperatures Tc b required to break a single contact in the MS packing for both single- and multiple-eigenmode perturbations of the T =0 MS packing. We find that the temperature required to break a single contact for equal velocity-amplitude perturbations involving all eigenmodes approaches the minimum value obtained for a perturbation in the direction connecting disk pairs with the smallest overlap. We then studied deviations in the constant volume specific heat C¯V and deviations of the average disk positions Δ r from their T =0 values in the temperature regime TC ¯V100 for linear spring interactions is independent of system size. This result emphasizes that contact-breaking nonlinearities are dominant over form nonlinearities in the low-temperature range Tc b

Breaking Kelvin-Helmholtz waves and cloud-top entrainment as revealed by K-band Doppler radar

NASA Technical Reports Server (NTRS)

Martner, Brooks E.; Ralph, F. Martin

1993-01-01

Radars have occasionally detected breaking Kelvin-Helmholtz (KH) waves under clear-air conditions in the atmospheric boundary layer and in the free troposphere. However, very few direct measurements of such waves within clouds have previously been reported and those have not clearly documented wave breaking. In this article, we present some of the most detailed and striking radar observations to date of breaking KH waves within clouds and at cloud top and discuss their relevance to the issue of cloud-top entrainment, which is believed to be important in convective and stratiform clouds. Aircraft observations reported by Stith suggest that vortex-like circulations near cloud top are an entrainment mechanism in cumuliform clouds. Laboratory and modeling studies have examined possibility that KH instability may be responsible for mixing at cloud top, but direct observations have not yet been presented. Preliminary analyses shown here may help fill this gap. The data presented in this paper were obtained during two field projects in 1991 that included observations from the NOAA Wave Propagation Laboratory's K-band Doppler radar (wavelength = 8.7 mm) and special rawinsonde ascents. The sensitivity (-30 dBZ at 10 km range), fine spatial resolution (375-m pulse length and 0.5 degrees beamwidth), velocity measurement precision (5-10 cm s-1), scanning capability, and relative immunity to ground clutter make it sensitive to non-precipitating and weakly precipitating clouds, and make it an excellent instrument to study gravity waves in clouds. In particular, the narrow beam width and short pulse length create scattering volumes that are cylinders 37.5 m long and 45 m (90 m) in diameter at 5 km (10 km) range. These characteristics allow the radar to resolve the detailed structure in breaking KH waves such as have been seen in photographic cloud images.

Bonding of glass with femtosecond laser pulses at high repetition rates

NASA Astrophysics Data System (ADS)

Richter, S.; Döring, S.; Tünnermann, A.; Nolte, S.

2011-05-01

We report on the welding of fused silica with ultrashort laser pulses at high repetition rates. Femtosecond laser pulses were focused at the interface of two optically contacted fused silica samples. Due to the nonlinear absorption in the focal volume and heat accumulation of successive pulses, the laser acts as a localized heat source at the focus position. Here, we analyze the influence of the laser and processing parameters on the amount of molten material. Moreover, we determine the achievable breaking stress by a three point bending test. With optimized parameters up to 75% of the breaking stress of the bulk material have been obtained.

A Study of Green's Function Methods Applied to Space Radiation Protection

NASA Technical Reports Server (NTRS)

Heinbockel, John H.

2001-01-01

The purpose of this research was to study the propagation of galactic ions through various materials. Galactic light ions result from the break up of heavy ion particles and their propagation through materials is modeled using the one-dimensional Boltzmann equation. When ions enter materials there can occur (i) the interaction of ions with orbital electrons which causes ionization within the material and (ii) ions collide with atoms causing production of secondary particles which penetrate deeper within the material. These processes are modeled by a continuum model. The basic idea is to place a control volume within the material and examine the change in ion flux across this control volume. In this way on can derive the basic equations for the transport of light and heavy ions in matter. Green's function perturbation methods can then be employed to solve the resulting equations using energy dependent nuclear cross sections.

Effect of different infusion regimens on colonic motility and efficacy of colostomy irrigation.

PubMed

Gattuso, J M; Kamm, M A; Myers, C; Saunders, B; Roy, A

1996-10-01

The colonic motility response and short-term clinical effectiveness of colonic irrigation was studied in five patients with an end-colostomy, each of whom was studied on up to six occasions, using volumes of 500 and 1500 ml water infused under gravity and over a period of 2.5 and 5 min with a pump. The median baseline colonic luminal pressure was 14 cmH2O and rose to 42 cmH2O with a 500-ml infusion, and to 74 cmH2O with a 1500-ml infusion. Irrigation induced high-pressure (over 200 cmH2O) propagated waves which caused the efflux of colonic contents. These were more numerous after a 1500- than a 500-ml infusion (median 4.5 versus 2.0 respectively). There was no difference between the two volumes infused in the incidence of colostomy break-through before subsequent irrigation. Colostomy irrigation with 500-1500 ml water appears to produce intracolonic pressure rises that are safe. These volumes can be infused rapidly under gravity alone.

Breaking up the transcription logjam can improve cash flow.

PubMed

Paulik, Dennis

2004-06-01

Using more than 20 transcription companies to handle its annual volume of 36 million lines, Health Midwest knew it had to gain control of the document transcription and delivery process. By centralizing its transcription service, the organization saved $600,000 and reduced days in accounts receivable by 10 days.

Diversity Digest. Volume 9, Number 3

ERIC Educational Resources Information Center

Musil, Caryn McTighe, Ed.; Hovland, Kevin, Ed.

2006-01-01

This issue of "Diversity Digest" grows out of one recent effort to raise the visibility of science in diversity and global learning initiatives. Articles in this issue include: (1) Science, Diversity, and Global Learning: Untangling Complex Problems (Kevin Hovland); (2) Breaking the Pyramid: Putting Science in the Core (Darcy Kelley);…

Application Trends Survey. 2014 Survey Report

ERIC Educational Resources Information Center

Worthington, Rebecca; Bruggeman, Paula

2014-01-01

Now in its 15th year, the Graduate Management Admission Council's assessment of application volume trends for graduate management programs offers timely insights into demographic shifts and other factors defining the candidate pools for the 2014 application cycle. Responses collected in the 2014 survey represent a record-breaking total of 748 MBA,…

Evolution of volume fractions and droplet sizes by analysis of electrical conductance curves during destabilization of oil-in-water emulsions.

PubMed

Kostoglou, M; Varka, E-M; Kalogianni, E P; Karapantsios, T D

2010-09-01

Destabilization of hexane-in-water emulsions is studied by a continuous, non-intrusive, multi-probe, electrical conductance technique. Emulsions made of different oil fractions and surfactant (C(10)E(5)) concentrations are prepared in a stirred vessel using a Rushton turbine to break and agitate droplets. During the separation of phases, electrical signals from pairs of ring electrodes mounted at different heights onto the vessel wall, are recorded. The evolution of the local water volume fractions at the locations of the electrodes is estimated from these signals. It is found that in the absence of coalescence, the water fraction evolution curve from the bottom pair of electrodes is compatible with a bidisperse oil droplet size distribution. The sizes and volume fractions of the two droplet modes are estimated using theoretical arguments. The electrically determined droplet sizes are compared to data from microscopy image analysis. Results are discussed in detail. Copyright 2010 Elsevier Inc. All rights reserved.

Towards realistic string vacua from branes at singularities

NASA Astrophysics Data System (ADS)

Conlon, Joseph P.; Maharana, Anshuman; Quevedo, Fernando

2009-05-01

We report on progress towards constructing string models incorporating both realistic D-brane matter content and moduli stabilisation with dynamical low-scale supersymmetry breaking. The general framework is that of local D-brane models embedded into the LARGE volume approach to moduli stabilisation. We review quiver theories on del Pezzo n (dPn) singularities including both D3 and D7 branes. We provide supersymmetric examples with three quark/lepton families and the gauge symmetries of the Standard, Left-Right Symmetric, Pati-Salam and Trinification models, without unwanted chiral exotics. We describe how the singularity structure leads to family symmetries governing the Yukawa couplings which may give mass hierarchies among the different generations. We outline how these models can be embedded into compact Calabi-Yau compactifications with LARGE volume moduli stabilisation, and state the minimal conditions for this to be possible. We study the general structure of soft supersymmetry breaking. At the singularity all leading order contributions to the soft terms (both gravity- and anomaly-mediation) vanish. We enumerate subleading contributions and estimate their magnitude. We also describe model-independent physical implications of this scenario. These include the masses of anomalous and non-anomalous U(1)'s and the generic existence of a new hyperweak force under which leptons and/or quarks could be charged. We propose that such a gauge boson could be responsible for the ghost muon anomaly recently found at the Tevatron's CDF detector.

The Buffalo Creek Archaeological Project. Volume 1: Background and Testing at 3MS346 and 3CG847 Mississippi and Craighead Counties, Arkansas

DTIC Science & Technology

1992-01-01

collapse, levee breaks, islands disappearing and others appearing are prominent in the accounts of people on or near rivers. Reelfoot Lake in western...components. Site 3MS346 also contained an Early Mississippi period, Big Lake phase component. At 3CG847, Early Mississippi period material recovered included...in 1967, Morse (1968) studied part of the Big Lake Wildlife Refuge in advance of pending efforts to widen a drainage channel there. As a result, the

Confronting effective models for deconfinement in dense quark matter with lattice data

NASA Astrophysics Data System (ADS)

Andersen, Jens O.; Brauner, Tomáš; Naylor, William R.

2015-12-01

Ab initio numerical simulations of the thermodynamics of dense quark matter remain a challenge. Apart from the infamous sign problem, lattice methods have to deal with finite volume and discretization effects as well as with the necessity to introduce sources for symmetry-breaking order parameters. We study these artifacts in the Polyakov-loop-extended Nambu-Jona-Lasinio (PNJL) model and compare its predictions to existing lattice data for cold and dense two-color matter with two flavors of Wilson quarks. To achieve even qualitative agreement with lattice data requires the introduction of two novel elements in the model: (i) explicit chiral symmetry breaking in the effective contact four-fermion interaction, referred to as the chiral twist, and (ii) renormalization of the Polyakov loop. The feedback of the dense medium to the gauge sector is modeled by a chemical-potential-dependent scale in the Polyakov-loop potential. In contrast to previously used analytical Ansätze, we determine its dependence on the chemical potential from lattice data for the expectation value of the Polyakov loop. Finally, we propose adding a two-derivative operator to our effective model. This term acts as an additional source of explicit chiral symmetry breaking, mimicking an analogous term in the lattice Wilson action.

Method of testing gas insulated systems for the presence of conducting particles utilizing a gas mixture of nitrogen and sulfur hexafluoride

DOEpatents

Wootton, Roy E.

1979-01-01

A method of testing a gas insulated system for the presence of conducting particles. The method includes inserting a gaseous mixture comprising about 98 volume percent nitrogen and about 2 volume percent sulfur hexafluoride into the gas insulated system at a pressure greater than 60 lb./sq. in. gauge, and then applying a test voltage to the system. If particles are present within the system, the gaseous mixture will break down, providing an indicator of the presence of the particles.

Hip Abductor Muscle Volume and Strength Differences Between Women With Chronic Hip Joint Pain and Asymptomatic Controls.

PubMed

Mastenbrook, Matthew J; Commean, Paul K; Hillen, Travis J; Salsich, Gretchen B; Meyer, Gretchen A; Mueller, Michael J; Clohisy, John C; Harris-Hayes, Marcie

2017-12-01

Study Design Secondary analysis, cross-sectional study. Background Chronic hip joint pain (CHJP) can lead to limitations in activity participation, but the musculoskeletal factors associated with the condition are relatively unknown. Understanding the factors associated with CHJP may help develop rehabilitation strategies to improve quality of life of individuals with long-term hip pain. Objectives To compare measures of hip abductor muscle volume and hip abductor muscle strength between women with CHJP and asymptomatic controls. Methods Thirty women, 15 with CHJP and 15 matched asymptomatic controls (age range, 18-40 years), participated in this study. Magnetic resonance imaging was used to determine the volume of the primary hip abductor muscles, consisting of the gluteus medius, gluteus minimus, a small portion of the gluteus maximus, and the tensor fascia latae, within a defined region of interest. Break tests were performed using a handheld dynamometer to assess hip abductor strength. During the strength test, the participant was positioned in sidelying with the involved hip in 15° of abduction. Independent-samples t tests were used to compare muscle volume and strength values between those with CHJP and asymptomatic controls. Results Compared to asymptomatic controls, women with CHJP demonstrated significantly increased gluteal muscle volume (228 ± 40 cm 3 versus 199 ± 29 cm 3 , P = .032), but decreased hip abductor strength (74.6 ± 16.8 Nm versus 93.6 ± 20.2 Nm, P = .009). There were no significant differences in tensor fascia lata muscle volume between the 2 groups (P = .640). Conclusion Women with CHJP appear to have larger gluteal muscle volume, but decreased hip abductor strength, compared to asymptomatic controls. J Orthop Sports Phys Ther 2017;47(12):923-930. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7380.

TYPE Ia SUPERNOVAE: CAN CORIOLIS FORCE BREAK THE SYMMETRY OF THE GRAVITATIONAL CONFINED DETONATION EXPLOSION MECHANISM?

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

García-Senz, D.; Cabezón, R. M.; Thielemann, F. K.

Currently the number of models aimed at explaining the phenomena of type Ia supernovae is high and distinguishing between them is a must. In this work we explore the influence of rotation on the evolution of the nuclear flame that drives the explosion in the so-called gravitational confined detonation models. Assuming that the flame starts in a pointlike region slightly above the center of the white dwarf (WD) and adding a moderate amount of angular velocity to the star we follow the evolution of the deflagration using a smoothed particle hydrodynamics code. We find that the results are very dependentmore » on the angle between the rotational axis and the line connecting the initial bubble of burned material with the center of the WD at the moment of ignition. The impact of rotation is larger for angles close to 90° because the Coriolis force on a floating element of fluid is maximum and its principal effect is to break the symmetry of the deflagration. Such symmetry breaking weakens the convergence of the nuclear flame at the antipodes of the initial ignition volume, changing the environmental conditions around the convergence region with respect to non-rotating models. These changes seem to disfavor the emergence of a detonation in the compressed volume at the antipodes and may compromise the viability of the so-called gravitational confined detonation mechanism.« less

The use of a break-even analysis: financial analysis of a fast-track program.

PubMed

Saywell, R M; Cordell, W H; Nyhuis, A W; Giles, B K; Culler, S D; Woods, J R; Chu, D K; McKinzie, J P; Rodman, G H

1995-08-01

To calculate the financial break-even point and illustrate how changes in third-party reimbursement and eligibility could affect a program's fiscal standing. Demographic, clinical, and financial data were collected retrospectively for 446 patients treated in a fast-track program during June 1993. The fast-track program is located within the confines of the emergency medicine and trauma center at a 1,050-bed tertiary care Midwestern teaching hospital and provides urgent treatment to minimally ill patients. A financial break-even analysis was performed to determine the point where the program generated enough revenue to cover its total variable and fixed costs, both direct and indirect. Given the relatively low average collection rate (62%) and high percentage of uninsured patients (31%), the analysis showed that the program's revenues covered its direct costs but not all of the indirect costs. Examining collection rates or payer class mix without examining both costs and revenues may lead to an erroneous conclusion about a program's fiscal viability. Sensitivity analysis also shows that relatively small changes in third-party coverage or eligibility (income) requirements can have a large impact on the program's financial solvency and break-even volumes.

Effect of orientation on electrically conducting thermoplastic composite properties

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

Genetti, W.B.; Grady, B.P.

1996-10-01

Properties of electrically conducting composites made from low density polyethylene (LDPE), high density polyethylene (HDPE), and polypropylene (PP) filled with nickel flake are being studied as a function of nickel concentration and draw ratio. The effect on electrical conduction, crystallinity, melt temperature, tensile modulus, and elongation at break are being tested. The melt temperature increases with increasing nickel concentration. The electrical conduction increases slowly with increased nickel concentration to the percolation volume fraction, then increases sharply. Orientation by uniaxial stretching of the films should allow conductive pathways to form throughout the polymer more easily by forcing particles closer together, thusmore » reducing the percolation volume fraction. This process could be caused by both alignment of the polymer chains and by stress induced crystallization that forces the particles into smaller amorphous regions.« less

Educational Linguistics in Practice: Applying the Local Globally and the Global Locally

ERIC Educational Resources Information Center

King, Kendall A.; Hult, Francis M.

2011-01-01

This volume provides a state-of-the-art snapshot of language and education research and demonstrates ways in which local and global processes are intertwined with language learning, use, and policies. Reflecting but also expanding on Nancy Hornberger's ground-breaking contributions to educational linguistics, this book brings together leading…

77 FR 6857 - Pipeline Safety: Notice of Public Meetings on Improving Pipeline Leak Detection System...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket ID... installed to lessen the volume of natural gas and hazardous liquid released during catastrophic pipeline... p.m. Panel 3: Considerations for Natural Gas Pipeline Leak Detection Systems 3:30 p.m. Break 3:45 p...

Computational comparison of high and low viscosity micro-scale droplets splashing on a dry surface

NASA Astrophysics Data System (ADS)

Boelens, Arnout; Latka, Andrzej; de Pablo, Juan

2015-11-01

Depending on viscosity, a droplet splashing on a dry surface can splash immediately upon impact, a so called prompt splash, or after initially spreading on the surface, a late splash. One of the open questions in splashing is whether the mechanism behind both kinds of splashing is the same or not. Simulation results are presented comparing splashing of low viscosity ethanol with high viscosity silicone oil in air. The droplets are several hundred microns large. The simulations are 2D, and are performed using a Volume Of Fluid approach with a Finite Volume technique. The contact line is described using the Generalized Navier Boundary Condition. Both the gas phase and the liquid phase are assumed to be incompressible. The results of the simulations show good agreement with experiments. Observations that are reproduced include the effect of reduced ambient pressure suppressing splashing, and the details of liquid sheet formation and breakup. While the liquid sheet ejected in an early splash breaks up at its far edge, the liquid sheet ejected in a late splash breaks up close to the droplet.

Female adolescents with severe substance and conduct problems have substantially less brain gray matter volume.

PubMed

Dalwani, Manish S; McMahon, Mary Agnes; Mikulich-Gilbertson, Susan K; Young, Susan E; Regner, Michael F; Raymond, Kristen M; McWilliams, Shannon K; Banich, Marie T; Tanabe, Jody L; Crowley, Thomas J; Sakai, Joseph T

2015-01-01

Structural neuroimaging studies have demonstrated lower regional gray matter volume in adolescents with severe substance and conduct problems. These research studies, including ours, have generally focused on male-only or mixed-sex samples of adolescents with conduct and/or substance problems. Here we compare gray matter volume between female adolescents with severe substance and conduct problems and female healthy controls of similar ages. Female adolescents with severe substance and conduct problems will show significantly less gray matter volume in frontal regions critical to inhibition (i.e. dorsolateral prefrontal cortex and ventrolateral prefrontal cortex), conflict processing (i.e., anterior cingulate), valuation of expected outcomes (i.e., medial orbitofrontal cortex) and the dopamine reward system (i.e. striatum). We conducted whole-brain voxel-based morphometric comparison of structural MR images of 22 patients (14-18 years) with severe substance and conduct problems and 21 controls of similar age using statistical parametric mapping (SPM) and voxel-based morphometric (VBM8) toolbox. We tested group differences in regional gray matter volume with analyses of covariance, adjusting for age and IQ at p<0.05, corrected for multiple comparisons at whole-brain cluster-level threshold. Female adolescents with severe substance and conduct problems compared to controls showed significantly less gray matter volume in right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, medial orbitofrontal cortex, anterior cingulate, bilateral somatosensory cortex, left supramarginal gyrus, and bilateral angular gyrus. Considering the entire brain, patients had 9.5% less overall gray matter volume compared to controls. Female adolescents with severe substance and conduct problems in comparison to similarly aged female healthy controls showed substantially lower gray matter volume in brain regions involved in inhibition, conflict processing, valuation of outcomes, decision-making, reward, risk-taking, and rule-breaking antisocial behavior.

Insights into subglacial eruptions based on geomorphometry: Broad scale analysis of subglacial edifices in Iceland

NASA Astrophysics Data System (ADS)

Pedersen, Gro; Grosse, Pablo

2014-05-01

The two main types of subglacial volcanic edifices, tuyas and tindars, have classicaly been known for their distinct morphometric characteristics. Tuyas are roughly equidimensional, steep-sided, flat topped mountains, while tindars are elongate, linear, steep sided, serrated ridges. In particular, the passage zone is morphometrically diagnostic, with a break in slope marking the transition from steep scree flanks to a low sloping lava cap [e.g. 1]. The passage zone thereby records the englacial water level coeval with delta formation and thereby provides important paleoenvironmental parameters regarding ice thickness, paleo-ice surface and the eruption environment. This study utilizes these morphometric characteristics to make a broad scale assessment of Icelandic subglacial edifices in the neovolcanic zone based on the TK-50 digital elevation model (20m/pixel) from the company Loftmyndir ehf. The edifice boundaries are delimited by concave breaks in slope around their bases and the passage zones are extracted as convex breaks in slope. This extraction is performed through object-based image analysis of slope and profile curvature maps with the eCognition program [2]. The MORVOLC code [3] is then used to calculate several morphometric parameters for each edifice: volume, edifice height, passage zone height, slope, base area, base width, ellipticity and irregularity. Analysis of the morphometric parameters allows grouping of subglacial edifices by to volume, with a continuum of landforms ranging from small tindars (group 1) to large tuyas (group 3), with an intermediate complex group of edifices (group 2). The plan shape indexes (ellipticity and irregularity) and the strike of main elongation show a first order correlation with the 3 classes and groups. Furthermore, correlations of passage zone heights, volumes and information regarding englacial lake stability allows us to investigate several aspects of tuya formation, including(1) spatial distribution of tuya sizes in rift and plume dominated volcanic systems, (2) estimation of paleo-ice surface height based on passage zone elevation, and (3) correlation between eruption size, approximate paleo-ice surface height and meltwater drainage. This study shows how a new semi-automated geomorphometric analysis of subglacial volcanic morphologies can provide information on the eruption environment. Furthermore, the technique can be used for submarine and planetary volcanic environments given a sufficiently accurate topographic model, providing a consistent approach to compare volcanic edifices in different environments. [1] Jones (1969) Quarterly Journal of the Geological Society 124, 197-211. [2] Benz et al. (2004) ISPRS Journal of photogrammetry & remote sensing 58, 239-258. [3] Grosse et al. (2012) Geomorphology 136, 114-131.

Analysis of the Spatio-Temporal Evolution of the Rockfalls in the Crater of Piton de la Fournaise Volcano, La Réunion, and their Link with the Eruptive Activity

NASA Astrophysics Data System (ADS)

Durand, V.; Mangeney, A.; Hibert, C.; Haas, F.; Peltier, A.; Kowalski, P.; Lauret, F.; Brunet, C.; Delorme, A.; Wegner, K.; Satriano, C.; Bonilla, L. F.; Aissaoui, E. M.; Protin, A.

2017-12-01

The seismic and photogrammetric networks of the Piton de la Fournaise volcano (La Réunion Island) are very well appropriate to study seismic signals generated by rockfalls in the Dolomieu crater. In particular, seismic data make it possible to precisely locate the rockfalls and recover the volume of each rockfall. Rockfall locations and volumes are validated comparing them to the ones obtained using photogrammetric data. We thus obtain an accurate catalog of 5802 rockfalls over the 2014-2016 period. This period is especially active, with 7 eruptions, after a break of 4 years. The analysis of the catalog reveals that the recovery of the eruptive activity unsettles the crater edges, increasing the average volume of the rockfalls. It also highlights that rain and seismicity could increase the volume of individual rockfalls. However, it seems that the pre-eruptive seismicity is the main triggering factor for larger volumes, with a delay of several days. We infer that the repetitive vibrations due to the high number of seismic events induce a cyclic fatigue of the material, leading to the collapse of large volumes. To better understand and discriminate the influence of seismicity and rainfall on the rockfall volumes, we investigate in the same way the transition period, from 2010 to 2014, during which there is no eruption. Finally, we show that before an eruption, the largest rockfalls tend to migrate towards the location of the eruption.

Evaluation and analysis of noise levels at traffic intersections of Nagpur city, India.

PubMed

Vijay, Ritesh; Popat, Rishabh; Pisode, Mayur; Sharma, Asheesh; Manoj, Kumar; Chakrabarti, T; Gupta, Rajesh

2013-04-01

The objective of the present study was to monitor and assess the noise levels at traffic intersections in Napgur city under heterogenic traffic activities. For this, traffic volume and noise level were measured at intersections on highways, major roads andring road during morning and evening peak hours. Traffic volume was categorized in light, medium and heavy vehicles while noise levels were measured for Lmin, Lmax, Leq , L10 and L90. Equivalent noise was observed in the range of 71.3 to 79.3 dB(A) at the traffic intersections. Due to heterogenic traffic conditions and activities at the intersection like honking, idling, gear noise, bearing noise, breaking noise, tyre-road noise and exhaust noise, no correlation was established between traffic volume and observed noise levels except West High Court road. A strong correlation was found at West High Court road due to controlled traffic flow and less impact of heavy vehicles. Impact of noisy vehicles on general traffic was also assessed at the traffic intersections based on noise pollution levels and traffic noise index. The study suggests that control measures are required at the traffic intersections to minimize noise pollution levels.

Exploration for heavy crude oil and natural bitumen

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

Not Available

1989-01-01

Heavy oil and tar sand reserves are enormous, and this 700-page volume breaks the topic down into six emphasis areas of: regional resources worldwide; characterization, maturation, and degradation; geological environments and migration; exploration methods; exploration histories; and recovery. An appendix presents a guidebook to Santa Maria, Cuyama, Taft-McKettrick, and Edna oil districts, Coast Ranges, California.

Challenging Stereotypes: An Action Guide. Consumer Information Series, Volume 5.

ERIC Educational Resources Information Center

Arnold, Jean; Weinerth, Nora

This booklet is intended to help decrease the barriers of prejudice toward people who have mental illnesses. It serves as an educational tool to eliminate the stigma associated with mental illness and to help develop anti-stigma or anti-discrimination programs. Increasingly, the media is doing a better job of breaking down the stereotypes…

Public Libraries and Community Economic Development: Partnering for Success. Rural Research Report. Volume 18, Issue 10, Winter 2008

ERIC Educational Resources Information Center

Hamilton-Pennell, Christine

2008-01-01

In the past decade, economic development experts have moved away from traditional approaches to economic development that have relied upon recruiting or attracting large businesses with offers of tax breaks, financial incentives, and other subsidies. Increasingly, communities are focusing their economic development resources on supporting the…

Developing a cardiopulmonary exercise testing laboratory.

PubMed

Diamond, Edward

2007-12-01

Cardiopulmonary exercise testing is a noninvasive and cost-effective technique that adds significant value to the assessment and management of a variety of symptoms and diseases. The penetration of this testing in medical practice may be limited by perceived operational and financial barriers. This article reviews coding and supervision requirements related to both simple and complex pulmonary stress testing. A program evaluation and review technique diagram is used to describe the work flow process. Data from our laboratory are used to generate an income statement that separates fixed and variable costs and calculates the contribution margin. A cost-volume-profit (break-even) analysis is then performed. Using data from our laboratory including fixed and variable costs, payer mix, reimbursements by payer, and the assumption that the studies are divided evenly between simple and complex pulmonary stress tests, the break-even number is calculated to be 300 tests per year. A calculator with embedded formulas has been designed by the author and is available on request. Developing a cardiopulmonary exercise laboratory is challenging but achievable and potentially profitable. It should be considered by a practice that seeks to distinguish itself as a quality leader. Providing this clinically valuable service may yield indirect benefits such as increased patient volume and increased utilization of other services provided by the practice. The decision for a medical practice to commit resources to managerial accounting support requires a cost-benefit analysis, but may be a worthwhile investment in our challenging economic environment.

Music-listening habits with MP3 player in a group of adolescents: a descriptive survey.

PubMed

Pellegrino, E; Lorini, C; Allodi, G; Buonamici, C; Garofalo, G; Bonaccorsi, G

2013-01-01

Listening to music through portable MP3 players has become a very popular mode among young people and adolescents. The aim of this study is to investigate the behaviors of adolescents engaged in listening to music with MP3 player and the attendance at clubs (pubs, discotheques) where music is played at high volume. Among the 1470 students attending a secondary school in Scandicci (FI) during the school year 2009/2010, 1278 (86.9%) were at school the day of the examination and 1276 completely filled in the questionnaire. Descriptive analysis and univariate and multivariate logistic regression were performed to calculate the degree of association (OR) among the sociodemographic characteristics, listening habits and some factors identified as risky or protective as regards the possibility of developing health disorders. MP3 player users are 88.2% of the sample. Among these, a high proportion engaged behaviours that increase the risk of presenting disorders, including the exposure to high-volume (27.4%). Furthermore, 44.6% use the MP3 while driving. From the regression analysis it emerges that MP3 users showed a sort of addiction: by increasing the time and the occasions of exposure to music, they increased the volume, used maximum or medium-high volume, did not take breaks and did not decrease the volume. The study points out the spread of risky behavior in music listening, so it is necessary to better inform especially the youngsters and achieve specific preventive interventions.

Wetting Heterogeneities in Porous Media Control Flow Dissipation

NASA Astrophysics Data System (ADS)

Murison, Julie; Semin, Benoît.; Baret, Jean-Christophe; Herminghaus, Stephan; Schröter, Matthias; Brinkmann, Martin

2014-09-01

Pressure-controlled displacement of an oil-water interface is studied in dense packings of functionalized glass beads with well-defined spatial wettability correlations. An enhanced dissipation is observed if the typical extension ξ of the same-type wetting domains is smaller than the average bead diameter d. Three-dimensional imaging using x-ray microtomography shows that the frequencies n(s) of residual droplet volumes s for different ξ collapse onto the same curve. This indicates that the additional dissipation for small ξ is due to contact line pinning rather than an increase of capillary break-up and coalescence events.

The enrichment of chlorogenic acid from Eucommia ulmoides leaves extract by mesoporous carbons.

PubMed

Qin, Guotong; Ma, Jing; Wei, Wei; Li, Jaja; Yue, Fangqing

2018-06-15

Herein, we report an efficient separation and enrichment method for chlorogenic acid from crude extracts of Eucommia ulmoides leaves using carbon adsorbents. The effects of the pore structure of the carbon adsorbents on the adsorption capacity were studied. Of the four adsorbents investigated, mesoporous carbon (MC3) showed the highest adsorption capacity (294 mg/g of carbon) for chlorogenic acid due to its high mesopore volume. The static adsorption of CGA on carbon can be accurately described using the Freundlich equation. The kinetics of adsorption follow a pseudo-second-order process. External mass transfer was the controlling step of the adsorption process. Dynamic adsorption on MC3 demonstrated that chlorogenic acid began to break through after 28 bed volumes of extract was loaded. This mesoporous carbon-treatment procedure is safe, economic and has the potential to be scaled up for commercial application. Copyright © 2018 Elsevier B.V. All rights reserved.

Rock Directed Breaking Under the Impulse Load

NASA Astrophysics Data System (ADS)

Khomeriki, Sergo; Mataradze, Edgar; Chikhradze, Nikoloz; Losaberidze, Marine; Khomeriki, Davit; Shatberashvili, Grigol

2016-10-01

In the work the problem of directed chipping of facing stone material by means of managing of explosion process is considered. The technology of the mining of decorative stone by the use of explosion energy means the very rapid transfer of potential energy of elastic deformations to kinetic energy. As a result, the explosion impulse, in the expanse of the inertia of rock massive, does not cause the increase of existing cracks. In the course of explosion, the shock wave is propagated by ultrasonic velocity and in this case the medium parameters (pressure, density, temperature, velocity) increase in spurts. In spite of this fact the all three conservation laws of mechanics remain valid on basis of three laws the equations are derived by which the parameters of shock wave may be defined by means of the rock physical-mechanical properties. The load on the body volume at breaking under explosion acts over very small period of the time. Therefore, stressed-deformed state of the rock was studied when the impulse load acts on the boundary. It was considered that the mining of the blocks of facing stone is performed from the hard rocks. This means that the breaking proceeds in the zone of elastic deformation. In the conditions of mentioned assumptions, the expression of the stress tensor and displacement of vector components initiated by stressed-deformed state in the rock are written.

Strontium administration in young chickens improves bone volume and architecture but does not enhance bone structural and material strength.

PubMed

Shahnazari, M; Lang, D H; Fosmire, G J; Sharkey, N A; Mitchell, A D; Leach, R M

2007-03-01

Genetic selection for rapid body growth in broiler chickens has resulted in adverse effects on the skeletal system exemplified by a higher rate of cortical fractures in leg bones. Strontium (Sr) has been reported to have beneficial effects on bone formation and strength. We supplemented the diet of 300-day-old chicks with increasing dosages of Sr (0%, 0.12%, or 0.24%) to study the capacity of the element to improve bone quality and mechanical integrity. Treatment with Sr increased cortical bone volume and reduced bone porosity as measured by micro-computed tomography. The higher level of Sr significantly reduced bone Ca content (34.7%) relative to controls (37.2%), suggesting that Sr replaced some of the Ca in bone. Material properties determined by the three-point bending test showed that bone in the Sr-treated groups withstood greater deformation prior to fracture. Load to failure and ultimate stress were similar across groups. Our results indicate that Sr treatment in rapidly growing chickens induced positive effects on bone volume but did not improve the breaking strength of long bones.

The solution of the dam-break problem in the Porous Shallow water Equations

NASA Astrophysics Data System (ADS)

Cozzolino, Luca; Pepe, Veronica; Cimorelli, Luigi; D'Aniello, Andrea; Della Morte, Renata; Pianese, Domenico

2018-04-01

The Porous Shallow water Equations are commonly used to evaluate the propagation of flooding waves in the urban environment. These equations may exhibit not only classic shocks, rarefactions, and contact discontinuities, as in the ordinary two-dimensional Shallow water Equations, but also special discontinuities at abrupt porosity jumps. In this paper, an appropriate parameterization of the stationary weak solutions of one-dimensional Porous Shallow water Equations supplies the inner structure of the porosity jumps. The exact solution of the corresponding dam-break problem is presented, and six different wave configurations are individuated, proving that the solution exists and it is unique for given initial conditions and geometric characteristics. These results can be used as a benchmark in order to validate one- and two-dimensional numerical models for the solution of the Porous Shallow water Equations. In addition, it is presented a novel Finite Volume scheme where the porosity jumps are taken into account by means of a variables reconstruction approach. The dam-break results supplied by this numerical scheme are compared with the exact dam-break results, showing the promising capabilities of this numerical approach. Finally, the advantages of the novel porosity jump definition are shown by comparison with other definitions available in the literature, demonstrating its advantages, and the issues raising in real world applications are discussed.

Hydrodynamic modeling of tsunamis from the Currituck landslide

USGS Publications Warehouse

Geist, E.L.; Lynett, P.J.; Chaytor, J.D.

2009-01-01

Tsunami generation from the Currituck landslide offshore North Carolina and propagation of waves toward the U.S. coastline are modeled based on recent geotechnical analysis of slide movement. A long and intermediate wave modeling package (COULWAVE) based on the non-linear Boussinesq equations are used to simulate the tsunami. This model includes procedures to incorporate bottom friction, wave breaking, and overland flow during runup. Potential tsunamis generated from the Currituck landslide are analyzed using four approaches: (1) tsunami wave history is calculated from several different scenarios indicated by geotechnical stability and mobility analyses; (2) a sensitivity analysis is conducted to determine the effects of both landslide failure duration during generation and bottom friction along the continental shelf during propagation; (3) wave history is calculated over a regional area to determine the propagation of energy oblique to the slide axis; and (4) a high-resolution 1D model is developed to accurately model wave breaking and the combined influence of nonlinearity and dispersion during nearshore propagation and runup. The primary source parameter that affects tsunami severity for this case study is landslide volume, with failure duration having a secondary influence. Bottom friction during propagation across the continental shelf has a strong influence on the attenuation of the tsunami during propagation. The high-resolution 1D model also indicates that the tsunami undergoes nonlinear fission prior to wave breaking, generating independent, short-period waves. Wave breaking occurs approximately 40-50??km offshore where a tsunami bore is formed that persists during runup. These analyses illustrate the complex nature of landslide tsunamis, necessitating the use of detailed landslide stability/mobility models and higher-order hydrodynamic models to determine their hazard.

Why do people google movement disorders? An infodemiological study of information seeking behaviors.

PubMed

Brigo, Francesco; Erro, Roberto

2016-05-01

Millions of people worldwide everyday search Google or Wikipedia to look for health-related information. Aim of this study was to evaluate and interpret web search queries for terms related to movement disorders (MD) in English-speaking countries and their changes over time. We analyzed information regarding the volume of online searches in Google and Wikipedia for the most common MD and their treatments. We determined the highest search volume peaks to identify possible relation with online news headlines. The volume of searches for some queries related to MD entered in Google enormously increased over time. Most queries were related to definition, subtypes, symptoms and treatment (mostly to adverse effects, or alternatively, to possible alternative treatments). The highest peaks of MD search queries were temporally related to news about celebrities suffering from MD, to specific mass-media events or to news concerning pharmaceutic companies or scientific discoveries on MD. An increasing number of people use Google and Wikipedia to look for terms related to MD to obtain information on definitions, causes and symptoms, possibly to aid initial self-diagnosis. MD information demand and the actual prevalence of different MDs do not travel together: web search volume may mirrors patients' fears and worries about some particular disorders perceived as more serious than others, or may be driven by release of news about celebrities suffering from MD, "breaking news" or specific mass-media events regarding MD.

Brain tumor locating in 3D MR volume using symmetry

NASA Astrophysics Data System (ADS)

Dvorak, Pavel; Bartusek, Karel

2014-03-01

This work deals with the automatic determination of a brain tumor location in 3D magnetic resonance volumes. The aim of this work is not the precise segmentation of the tumor and its parts but only the detection of its location. This work is the first step in the tumor segmentation process, an important topic in neuro-image processing. The algorithm expects 3D magnetic resonance volumes of brain containing a tumor. The detection is based on locating the area that breaks the left-right symmetry of the brain. This is done by multi-resolution comparing of corresponding regions in left and right hemisphere. The output of the computation is the probabilistic map of the tumor location. The created algorithm was tested on 80 volumes from publicly available BRATS databases containing 3D brain volumes afflicted by a brain tumor. These pathological structures had various sizes and shapes and were located in various parts of the brain. The locating performance of the algorithm was 85% for T1-weighted volumes, 91% for T1-weighted contrast enhanced volumes, 96% for FLAIR and T2-wieghted volumes and 95% for their combinations.

Theoretical and Experimental Investigations of the Process of Vibration Treatment of Liquid Metals Containing Nanoparticles

NASA Astrophysics Data System (ADS)

Vorozhtsov, S.; Kudryashova, O.; Promakhov, V.; Dammer, V.; Vorozhtsov, A.

2016-12-01

It is known that the use of external effects, such as acoustic fields (from ultrasonic to low-frequency range), help in breaking down agglomerates, improving particle wettability, providing uniform particle distribution in the melt volume, and reducing the grain size. The fragmentation of growing crystals, de-agglomeration of particles and their mixing in liquid metal under the influence of vibration (with frequencies of 10-100 Hz) are considered in this paper. The major advantage of such a technique in comparison with high-frequency methods (sonic, ultrasonic) is the capability of processing large melt volumes proportional to the wavelength. The mechanisms of the breaking down of particle agglomerates and the mixing of particles under conditions of cavitation and turbulence during the vibration treatment of the melt are considered. Expressions linking the threshold intensity and frequency with the amplitude necessary to activate mechanisms of turbulence and cavitation were obtained. The results of vibration treatment experiments for an aluminum alloy containing diamond nanoparticles are given. This treatment makes it possible to significantly reduce the grain size and to improve the casting homogeneity and thus improve the mechanical properties of the alloy.

Quantifying the behavior of price dynamics at opening time in stock market

NASA Astrophysics Data System (ADS)

Ochiai, Tomoshiro; Takada, Hideyuki; Nacher, Jose C.

2014-11-01

The availability of huge volume of financial data has offered the possibility for understanding the markets as a complex system characterized by several stylized facts. Here we first show that the time evolution of the Japan’s Nikkei stock average index (Nikkei 225) futures follows the resistance and breaking-acceleration effects when the complete time series data is analyzed. However, in stock markets there are periods where no regular trades occur between the close of the market on one day and the next day’s open. To examine these time gaps we decompose the time series data into opening time and intermediate time. Our analysis indicates that for the intermediate time, both the resistance and the breaking-acceleration effects are still observed. However, for the opening time there are almost no resistance and breaking-acceleration effects, and volatility is always constantly high. These findings highlight unique dynamic differences between stock markets and forex market and suggest that current risk management strategies may need to be revised to address the absence of these dynamic effects at the opening time.

Ionizing radiation, ion transports, and radioresistance of cancer cells

PubMed Central

Huber, Stephan M.; Butz, Lena; Stegen, Benjamin; Klumpp, Dominik; Braun, Norbert; Ruth, Peter; Eckert, Franziska

2013-01-01

The standard treatment of many tumor entities comprises fractionated radiation therapy which applies ionizing radiation to the tumor-bearing target volume. Ionizing radiation causes double-strand breaks in the DNA backbone that result in cell death if the number of DNA double-strand breaks exceeds the DNA repair capacity of the tumor cell. Ionizing radiation reportedly does not only act on the DNA in the nucleus but also on the plasma membrane. In particular, ionizing radiation-induced modifications of ion channels and transporters have been reported. Importantly, these altered transports seem to contribute to the survival of the irradiated tumor cells. The present review article summarizes our current knowledge on the underlying mechanisms and introduces strategies to radiosensitize tumor cells by targeting plasma membrane ion transports. PMID:23966948

Celeris: A GPU-accelerated open source software with a Boussinesq-type wave solver for real-time interactive simulation and visualization

NASA Astrophysics Data System (ADS)

Tavakkol, Sasan; Lynett, Patrick

2017-08-01

In this paper, we introduce an interactive coastal wave simulation and visualization software, called Celeris. Celeris is an open source software which needs minimum preparation to run on a Windows machine. The software solves the extended Boussinesq equations using a hybrid finite volume-finite difference method and supports moving shoreline boundaries. The simulation and visualization are performed on the GPU using Direct3D libraries, which enables the software to run faster than real-time. Celeris provides a first-of-its-kind interactive modeling platform for coastal wave applications and it supports simultaneous visualization with both photorealistic and colormapped rendering capabilities. We validate our software through comparison with three standard benchmarks for non-breaking and breaking waves.

Modeling quiescent phase transport of air bubbles induced by breaking waves

NASA Astrophysics Data System (ADS)

Shi, Fengyan; Kirby, James T.; Ma, Gangfeng

Simultaneous modeling of both the acoustic phase and quiescent phase of breaking wave-induced air bubbles involves a large range of length scales from microns to meters and time scales from milliseconds to seconds, and thus is computational unaffordable in a surfzone-scale computational domain. In this study, we use an air bubble entrainment formula in a two-fluid model to predict air bubble evolution in the quiescent phase in a breaking wave event. The breaking wave-induced air bubble entrainment is formulated by connecting the shear production at the air-water interface and the bubble number intensity with a certain bubble size spectra observed in laboratory experiments. A two-fluid model is developed based on the partial differential equations of the gas-liquid mixture phase and the continuum bubble phase, which has multiple size bubble groups representing a polydisperse bubble population. An enhanced 2-DV VOF (Volume of Fluid) model with a k - ɛ turbulence closure is used to model the mixture phase. The bubble phase is governed by the advection-diffusion equations of the gas molar concentration and bubble intensity for groups of bubbles with different sizes. The model is used to simulate air bubble plumes measured in laboratory experiments. Numerical results indicate that, with an appropriate parameter in the air entrainment formula, the model is able to predict the main features of bubbly flows as evidenced by reasonable agreement with measured void fraction. Bubbles larger than an intermediate radius of O(1 mm) make a major contribution to void fraction in the near-crest region. Smaller bubbles tend to penetrate deeper and stay longer in the water column, resulting in significant contribution to the cross-sectional area of the bubble cloud. An underprediction of void fraction is found at the beginning of wave breaking when large air pockets take place. The core region of high void fraction predicted by the model is dislocated due to use of the shear production in the algorithm for initial bubble entrainment. The study demonstrates a potential use of an entrainment formula in simulations of air bubble population in a surfzone-scale domain. It also reveals some difficulties in use of the two-fluid model for predicting large air pockets induced by wave breaking, and suggests that it may be necessary to use a gas-liquid two-phase model as the basic model framework for the mixture phase and to develop an algorithm to allow for transfer of discrete air pockets to the continuum bubble phase. A more theoretically justifiable air entrainment formulation should be developed.

Breaking of rod-shaped model material during compression

NASA Astrophysics Data System (ADS)

Lukas, Kulaviak; Vera, Penkavova; Marek, Ruzicka; Miroslav, Puncochar; Petr, Zamostny; Zdenek, Grof; Frantisek, Stepanek; Marek, Schongut; Jaromir, Havlica

2017-06-01

The breakage of a model anisometric dry granular material caused by uniaxial compression was studied. The bed of uniform rod-like pasta particles (8 mm long, aspect ratio 1:8) was compressed (Gamlen Tablet Press) and their size distribution was measured after each run (Dynamic Image Analysing). The compression dynamics was recorded and the effect of several parameters was tested (rate of compression, volume of granular bed, pressure magnitude and mode of application). Besides the experiments, numerical modelling of the compressed breakable material was performed as well, employing the DEM approach (Discrete Element Method). The comparison between the data and the model looks promising.

Breakdown of String Perturbation Theory for Many External Particles.

PubMed

Ghosh, Sudip; Raju, Suvrat

2017-03-31

We consider massless string scattering amplitudes in a limit where the number of external particles becomes very large, while the energy of each particle remains small. Using the growth of the volume of the relevant moduli space, and by means of independent numerical evidence, we argue that string perturbation theory breaks down in this limit. We discuss some remarkable implications for the information paradox.

Intelligence Secrecy and Transparency: Finding the Proper Balance from the War of Independence to the War on Terror (Strategic Insights, Volume 6, Issue 3, May 2007)

DTIC Science & Technology

2007-05-01

NIE), requested by Congress, prior to the House and Senate vote to authorize the President to use force against Iraq. Secretary of State Colin ... Bamford , The Puzzle Palace (London: Penguin Books, 1982), and David Kahn, Seizing the Enigma: The Race to Break the German U-Boat Codes 1939-1943

Marine Structural Steel Toughness Data Bank. Volume 4

DTIC Science & Technology

1990-08-31

Break? Did specimen fracture completely? CODIc Critical COD CODi Initial COD CVN Energy Charpy V Energy Crack lgth Crack Length Curve Curve Shape DT...Onien Test Temp COIi CODIc i1 imax Tear Mod degF in In in-lb/in**2 in-lb/in**2 in-lb/in**2 L-T 72 0.0236 0.0380 4346 4315 260.2 L-T 72

Physical measurements of breaking wave impact on a floating wave energy converter

NASA Astrophysics Data System (ADS)

Hann, Martyn R.; Greaves, Deborah M.; Raby, Alison

2013-04-01

Marine energy converter must both efficiently extract energy in small to moderate seas and also successfully survive storms and potential collisions. Extreme loads on devices are therefore an important consideration in their design process. X-MED is a SuperGen UKCMER project and is a collaboration between the Universities of Manchester, Edinburgh and Plymouth and the Scottish Association for Marine Sciences. Its objective is to extend the knowledge of extreme loads due to waves, currents, flotsam and mammal impacts. Plymouth Universities contribution to the X-MED project involves measuring the loading and response of a taut moored floating body due to steep and breaking wave impacts, in both long crested and directional sea states. These measurements are then to be reproduced in STAR-CCM+, a commercial volume of fluid CFD solver, so as to develop techniques to predict the wave loading on wave energy converters. The measurements presented here were conducted in Plymouth Universities newly opened COAST laboratories 35m long, 15.5m wide and 3m deep ocean basin. A 0.5m diameter taut moored hemispherical buoy was used to represent a floating wave energy device or support structure. The changes in the buoys 6 degree of freedom motion and mooring loads are presented due to focused breaking wave impacts, with the breaking point of the wave changed relative to the buoy.

The dynamics of a channel-fed lava flow on Pico Partido volcano, Lanzarote

NASA Astrophysics Data System (ADS)

Woodcock, Duncan; Harris, Andrew

2006-09-01

A short length of channel on Pico Partido volcano, Lanzarote, provides us the opportunity to examine the dynamics of lava flowing in a channel that extends over a sudden break in slope. The 1 2-m-wide, 0.5 2-m-deep channel was built during the 1730 1736 eruptions on Lanzarote and exhibits a sinuous, well-formed channel over a steep (11° slope) 100-m-long proximal section. Over-flow units comprising smooth pahoehoe sheet flow, as well as evidence on the inner channel walls for multiple (at least 11) flow levels, attest to unsteady flow in the channel. In addition, superelevation is apparent at each of the six bends along the proximal channel section. Superelevation results from banking of the lava as it moves around the bend thus causing preferential construction of the outer bank. As a result, the channel profile at each bend is asymmetric with an outer bank that is higher than the inner bank. Analysis of superelevation indicates flow velocities of ~8 m s 1. Our analysis of the superelevation features is based on an inertia-gravity balance, which we show is appropriate, even though the down-channel flow is in laminar flow. We use a viscosity-gravity balance model, together with the velocities calculated from superelevation, to obtain viscosities in the range 25 60 Pa s (assuming that the lava behaved as a Newtonian liquid). Estimated volume fluxes are in the range 7 12 m3 s 1. An apparent down-flow increase in derived volume flux may have resulted from variable supply or bulking up of the flow due to vesiculation. Where the channel moves over a sharp break in slope and onto slopes of ~6°, the channel becomes less well defined and widens considerably. At the break of slope, an elongate ridge extends across the channel. We speculate that this ridge was formed as a result of a reduction in velocity immediately below the break of slope to allow deposition of entrained material or accretion of lava to the channel bed as a result of a change in flow regime or depth.

Inlet Diameter and Flow Volume Effects on Separation and Energy Efficiency of Hydrocyclones

NASA Astrophysics Data System (ADS)

Erikli, Ş.; Olcay, A. B.

2015-08-01

This study investigates hydrocyclone performance of an oil injected screw compressor. Especially, the oil separation efficiency of a screw compressor plays a significant role for air quality and non-stop working hour of compressors has become an important issue when the efficiency in energy is considered. In this study, two separation efficiency parameters were selected to be hydrocyclone inlet diameter and flow volume height between oil reservoir surface and top of the hydrocyclone. Nine different cases were studied in which cyclone inlet diameter and flow volume height between oil reservoir surface and top were investigated in regards to separation and energy performance aspects and the effect of the parameters on the general performance appears to be causing powerful influence. Flow inside the hydrocyclone geometry was modelled by Reynolds Stress Model (RSM) and hydro particles were tracked by Discrete Phase Model (DPM). Besides, particle break up was modelled by the Taylor Analogy Breakup (TAB) model. The reversed vortex generation was observed at different planes. The upper limit of the inlet diameter of the cyclone yields the centrifugal force on particles to decrease while the flow becomes slower; and the larger diameter implies slower flow. On the contrary, the lower limit is increment in speed causes breakup problems that the particle diameters become smaller; consequently, it is harder to separate them from gas.

Improving Short Wave Breaking Behavior In Surfbeat Models

NASA Astrophysics Data System (ADS)

Roelvink, J.; Daly, C.; Vandongeren, A. R.; van Thiel de Vries, J.; McCall, R.

2009-12-01

In present surfzone modeling three approaches are widely applied: short-wave resolving models, ‘surfbeat’ models, which resolve wave energy modulations on the time-scale of wave groups and their associated infragravity waves, and wave averaged models. In all three approaches, wave breaking is a process that is highly schematized and governed by several empirical coefficients. In this presentation we will focus on the breaking process in ‘surfbeat’ models, such as XBeach (Roelvink et al, 2009). These models need to describe the short wave dissipation by breaking as a function of the slowly-varying short wave energy or wave height. The model usually applied is that by Roelvink (1993), which combines a probability that waves are breaking as function of wave heigth over water depth ratio H/h with a bore-type dissipation formulation similar to that by Battjes and Janssen (1978). A drawback of such a formulation is that there is no ‘memory’ in the breaking process, and the amount of breaking instantly varies with the water depth (though the wave height itself does have a memory). For cases with bichromatic waves, or for long-period swell, this does not reflect reality enough: waves that start breaking do not instantly stop breaking once the water depth increases, but continue until some lower threshold is reached. This concept was captured in Dally’s (1992) wave-by-wave approach, where individual waves are tracked in a probabilistic setting. We have now implemented a similar formulation in XBeach, where the property that waves are breaking is tracked; it is switched on when H/h exceeds a first criterion; this property is propagated using an advection equation and when H/h gets below a second criterion breaking is switched off. This formulation can do two things the previous one can’t: maintain groupiness inside the surf zone and have a maximum of wave breaking in the trough after a steep bar, as was observed for instance in Arcilla et al’s (1994) test 1C. Obviously this has important consequences for the forcing of both long waves and mean currents. In our presentation we will show results of comparisons of both formulations. References. Arcilla, A.S., Roelvink, J.A., O'Connor, B.A. Reniers, A., and Jimenez. J.A. The Delta Flume '93 Experiment. Coastal Dynamics '94. Arcilla, Stive and Kraus (eds), ASCE, New York, pp. 488-502. Battjes, J.A. and J.P.F.M. Janssen, (1978), Energy loss and set-up due to breaking in random waves, Proc. 16th Int. Coastal Eng. Conf., Hamburg, vol. 1: 569-587. Dally, W.R. (1992) Random breaking waves: Field verification of a wave-by-wave algorithm for engineering application. Coastal Engineering, Volume 16, Issue 4, March 1992, Pages 369-397. Roelvink, Dano, Ad Reniers, Ap van Dongeren, Jaap van Thiel de Vries, Robert McCall, Jamie Lescinski. Modelling storm impacts on beaches, dunes and barrier islands, Coast. Eng. (2009), doi:10.1016/j.coastaleng.2009.08.006 Roelvink, J.A. Dissipation in random wave groups incident on a beach. Coastal Eng., 19 (1993) pp. 127-150.

Benthic study of the continental slope off Cape Hatteras, North Carolina. Volume 3. Appendices

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

Diaz, R.J.; Blake, J.A.; Lohse, D.P.

1993-03-01

The Point is an area that supports a most productive pelagic fishery, including tuna, swordfish, marlin, and more. The objective of the study is to analyze video tapes from near the Point, in order to provide data on epibenthic, megafaunal invertebrates including species composition, relative abundances, and large scale (1 km) distribution. The Point is not a defined spot on a chart. Although fishermen do use the steep shelf break for location, they generally look for the west wall of the Gulf Stream. The Point and the oil lease site coincidentally occur where the Gulf Stream parts the continental slope,more » just north of the eastern-most tip of Cape Hatteras.« less

Microwave dielectric study of polar liquids at 298 K

NASA Astrophysics Data System (ADS)

Maharolkar, Aruna P.; Murugkar, A.; Khirade, P. W.

2018-05-01

Present paper deals with study of microwave dielectric properties like dielectric constant, viscosity, density and refractive index for the binary mixtures of Dimethylsulphoxide (DMSO) and Methanol over the entire concentration range were measured at 298K. The experimental data further used to determine the excess properties viz. excess static dielectric constant, excess molar volume, excess viscosity& derived properties viz. molar refraction&Bruggman factor. The values of excess properties further fitted with Redlich-Kister (R-K Fit) equation to calculate the binary coefficients and standard deviation. The resulting excess parameters are used to indicate the presence of intermolecular interactions and strength of intermolecular interactions between the molecules in the binary mixtures. Excess parameters indicate structure breaking factor in the mixture predominates in the system.

The Phenomenon of Superheat of Liquids: In Memory of Vladimir P. Skripov

NASA Astrophysics Data System (ADS)

Skripov, P. V.; Skripov, A. P.

2010-05-01

This article is devoted to the memory of Vladimir P. Skripov (1927-2006). He has received worldwide recognition for his monograph on metastable liquids published in 1972 (the English edition was published in 1974). We briefly discuss some studies deal with the phenomenon of attainable superheat of liquids and with measurements of thermophysical properties of liquids under conditions of a moderate degree of superheat. Main attention is paid to the studies performed by V.P. Skripov and his research group in the 1960s and 1970s. Experimental methods which provided break-throughs in research on both spontaneous boiling-up kinetics and substance properties (the specific volume, isobaric heat capacity, ultrasound speed, and viscosity) in super-heated states are presented.

Evaluation of Intersection Traffic Control Measures through Simulation

NASA Astrophysics Data System (ADS)

Asaithambi, Gowri; Sivanandan, R.

2015-12-01

Modeling traffic flow is stochastic in nature due to randomness in variables such as vehicle arrivals and speeds. Due to this and due to complex vehicular interactions and their manoeuvres, it is extremely difficult to model the traffic flow through analytical methods. To study this type of complex traffic system and vehicle interactions, simulation is considered as an effective tool. Application of homogeneous traffic models to heterogeneous traffic may not be able to capture the complex manoeuvres and interactions in such flows. Hence, a microscopic simulation model for heterogeneous traffic is developed using object oriented concepts. This simulation model acts as a tool for evaluating various control measures at signalized intersections. The present study focuses on the evaluation of Right Turn Lane (RTL) and Channelised Left Turn Lane (CLTL). A sensitivity analysis was performed to evaluate RTL and CLTL by varying the approach volumes, turn proportions and turn lane lengths. RTL is found to be advantageous only up to certain approach volumes and right-turn proportions, beyond which it is counter-productive. CLTL is found to be advantageous for lower approach volumes for all turn proportions, signifying the benefits of CLTL. It is counter-productive for higher approach volume and lower turn proportions. This study pinpoints the break-even points for various scenarios. The developed simulation model can be used as an appropriate intersection lane control tool for enhancing the efficiency of flow at intersections. This model can also be employed for scenario analysis and can be valuable to field traffic engineers in implementing vehicle-type based and lane-based traffic control measures.

The Shock and Vibration Digest. Volume 13, Number 10

DTIC Science & Technology

1981-10-01

shells when they impact rigid barriers. Such behavior is of interest in the protection of nuclear power plants . Progress on the MENTOR finite...pipewhip restraints during a postulated pipe break in a nuclear power plant . Other experimental work [124] also provioes valuable information on the...World Congr. Space Enclosures, Bldg. Res. Ctr., Con- cordia Univ., Montreal, pp 321-327 (July 1976). 48. Stolarski, H., "Assessment of Large Displace

Defense AT&L. Volume 39, Number 2, March-April 2010

DTIC Science & Technology

2010-04-01

have significant benefit to future systems concepts in the department. Q You also mentioned that there was a Developmental Test and Evaluation...enemy will engage. Identifying break- through capabilities can garner DoD significant advantages over potential adversaries. What does DDR&E do to...absolutely critical. We are working to protect them in a significant way. We have significant investments and programs looking at how we build very

Processing consequences of superfluous and missing prosodic breaks in auditory sentence comprehension.

PubMed

Bögels, Sara; Schriefers, Herbert; Vonk, Wietske; Chwilla, Dorothee J; Kerkhofs, Roel

2013-11-01

This ERP study investigates whether a superfluous prosodic break (i.e., a prosodic break that does not coincide with a syntactic break) has more severe processing consequences during auditory sentence comprehension than a missing prosodic break (i.e., the absence of a prosodic break at the position of a syntactic break). Participants listened to temporarily ambiguous sentences involving a prosody-syntax match or mismatch. The disambiguation of these sentences was always lexical in nature in the present experiment. This contrasts with a related study by Pauker, Itzhak, Baum, and Steinhauer (2011), where the disambiguation was of a lexical type for missing PBs and of a prosodic type for superfluous PBs. Our results converge with those of Pauker et al. (2011): superfluous prosodic breaks lead to more severe processing problems than missing prosodic breaks. Importantly, the present results extend those of Pauker et al. (2011) showing that this holds when the disambiguation is always lexical in nature. Furthermore, our results show that the way listeners use prosody can change over the course of the experiment which bears consequences for future studies. © 2013 Elsevier Ltd. All rights reserved.

Unimodular Einstein-Cartan gravity: Dynamics and conservation laws

NASA Astrophysics Data System (ADS)

Bonder, Yuri; Corral, Cristóbal

2018-04-01

Unimodular gravity is an interesting approach to address the cosmological constant problem, since the vacuum energy density of quantum fields does not gravitate in this framework, and the cosmological constant appears as an integration constant. These features arise as a consequence of considering a constrained volume element 4-form that breaks the diffeomorphisms invariance down to volume preserving diffeomorphisms. In this work, the first-order formulation of unimodular gravity is presented by considering the spin density of matter fields as a source of spacetime torsion. Even though the most general matter Lagrangian allowed by the symmetries is considered, dynamical restrictions arise on their functional dependence. The field equations are obtained and the conservation laws associated with the symmetries are derived. It is found that, analogous to torsion-free unimodular gravity, the field equation for the vierbein is traceless; nevertheless, torsion is algebraically related to the spin density as in standard Einstein-Cartan theory. The particular example of massless Dirac spinors is studied, and comparisons with standard Einstein-Cartan theory are shown.

Evolution of the Arctic-North Atlantic and the Western Tethys

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

Ziegler, P.A.

1988-01-01

This volume provides an overview of the late Paleozoic to recent geological evolution of the continents and shelves bordering the North Atlantic Ocean, the Norwegian-Greenland Sea, the Arctic Ocean, and the Mediterranean Sea. The evolution of these seas has been the subject of many studies and compilations, which discuss the evolution of oceanic basins on the basis of their magnetic sea-floor anomalies. The volume presented combines this information with geological data from the adjacent shelf and onshore areas. It retraces the evolution of sedimentary basins developed during the rifting phases that preceded the opening of these oceans and highlights themore » scope of the associated intra-plate phenomena. The author presents a reconstruction of the late Paleozoic and early Mesozoic development of Europe, northernmost Africa and northeastern North America-Greenland and discusses the different orogenic cycles that accompanied the stepwise assembly of Pangea and the early rifting phases heralding its break-up.« less

Puffing Topography and Nicotine Intake of Electronic Cigarette Users

PubMed Central

Behar, Rachel Z.; Hua, My; Talbot, Prue

2015-01-01

Background Prior electronic cigarette (EC) topography data are based on two video analyses with limited parameters. Alternate methods for measuring topography are needed to understand EC use and nicotine intake. Objectives This study evaluated EC topography with a CReSS Pocket device and quantified nicotine intake. Methods Validation tests on pressure drop, flow rate, and volume confirmed reliable performance of the CReSS Pocket device. Twenty participants used Blu Cigs and V2 Cigs for 10 minute intervals with a 10–15 minute break between brands. Brand order was reversed and repeated within 7 days Data were analyzed to determine puff duration, puff count, volume, flow rate, peak flow, and inter-puff interval. Nicotine intake was estimated from cartomizer fluid consumption and topography data. Results Nine patterns of EC use were identified. The average puff count and inter-puff interval were 32 puffs and 17.9 seconds. All participants, except one, took more than 20 puffs/10 minutes. The averages for puff duration (2.65 seconds/puff), volume/puff (51ml/puff), total puff volume (1,579 ml), EC fluid consumption (79.6 mg), flow rate (20 ml/s), and peak flow rate (27 ml/s) were determined for 10-minute sessions. All parameters except total puff count were significantly different for Blu versus V2 EC. Total volume for Blu versus V2 was four-times higher than for conventional cigarettes. Average nicotine intake for Blu and V2 across both sessions was 1.2 ± 0.5 mg and 1.4 ± 0.7 mg, respectively, which is similar to conventional smokers. Conclusions EC puffing topography was variable among participants in the study, but often similar within an individual between brands or days. Puff duration, inter-puff interval, and puff volume varied from conventional cigarette standards. Data on total puff volume and nicotine intake are consistent with compensatory usage of EC. These data can contribute to the development of a standard protocol for laboratory testing of EC products. PMID:25664463

Long-term hormonal contraceptive use is associated with a reversible suppression of antral follicle count and a break from hormonal contraception may improve oocyte yield.

PubMed

Letourneau, Joseph M; Cakmak, Hakan; Quinn, Molly; Sinha, Nikita; I Cedars, Marcelle; Rosen, Mitchell P

2017-09-01

Unlike infertility, patients presenting for fertility preservation (FP) are often using combined hormonal contraceptives (CHC). We studied whether long-term (≥6 months) CHC use is associated with reversible suppression of antral follicle count (AFC). This is a longitudinal study of FP cycles from 2012 to 2016. We studied three groups: those without CHC exposure (NO CHC), those with CHC usage with a CHC break (BREAK), and without a break (NO BREAK) prior to ovarian stimulation. We assessed ovarian reserve by AFC at initial consultation and discussed the possibility of CHC suppression of AFC. Patients chose between ovarian stimulation with no CHC break versus ovarian stimulation after a CHC break. AFC was measured serially in the BREAK group. We assessed whether AFC suppression was reversed in the BREAK group. Total oocyte yield was compared among the NO CHC, BREAK, and NO BREAK groups. T tests, ANOVA, and linear/logistic regressions were used. Seven hundred forty-three women underwent FP. Twenty-one percent (n = 154) were taking long-term CHC (≥6 months). AFC suppression was more likely with CHC use (OR 1.6, 95% CI 1.1-2.4, P = 0.011). The BREAK group (n = 79) stopped CHC for an average of 4 months. AFC improvement started at 1 month and plateaued at approximately 6- to 7-month break. The BREAK group had approximately twice as many oocytes per initial AFC as NO BREAK (2.8 ± 3.8 vs. 1.4 ± 0.9, P < 0.001). When women present for FP on CHC, AFC may be suppressed. A CHC break of several months is associated with an increase in AFC and a potential improvement in overall egg yield.

Solute-solvent interactions in solutions of 2-hydroxy-5-chloro-3-nitroacetophenone isonicotinoylhydrazone in N, N-dimethylformamide at 298-313 K according to ultrasonic and viscometric data

NASA Astrophysics Data System (ADS)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2015-12-01

Density (ρ), speed of sound ( u), and viscosity (η), measurements have been carried on 2-hydroxy- 5-chloro-3-nitroacetophenone isonicotinoylhydrazone (HCNAIH) in N, N-dimethylformamide at 298.15, 303.15, 308.15, and 313.15 K. Adiabatic compressibility (βs), intermolecular free length ( L f), acoustic impedance ( Z), internal pressure ( P int), the apparent molar volume ( V w), limiting apparent molar volume ( V w 0), partial molar expansibility (wE 0), apparent molar adiabatic compressibility ( K w), limiting apparent molar adiabatic compressibility ( K w 0), viscosity B coefficients of Jones-Dole equation have been calculated. The activation free energy (Δμ 2 0 *) for viscous flow in solution have been calculated from B coefficient and partial molar volume data. The calculated parameters are used to interpret the solute-solvent interactions and structure forming/breaking ability of solute in DMF.

Evaluation of an Electrostatic Dust Removal System with Potential Application in Next-Step Fusion Devices

NASA Technical Reports Server (NTRS)

Friesen, F. Q. L.; John, B.; Skinner, C. H.; Roquemore, A. L.; Calle, C. I.

2011-01-01

The ability to manage inventories of carbon, tritium, and high-Z elements in fusion plasmas depends on means for effective dust removal. A dust conveyor, based on a moving electrostatic potential well, was tested with particles of tungsten, carbon, glass and sand. A digital microscope imaged a representative portion of the conveyor, and dust particle size and volume distributions were derived before and after operation. About 10 cu mm volume of carbon and tungsten particles were moved in under 5 seconds. The highest driving amplitude tested of 3 kV was the most effective. The optimal driving frequency was 210 Hz (maximum tested) for tungsten particles, decreasing to below 60 Hz for the larger sand particles. Measurements of particle size and volume distributions after 10 and 100 cycles show the breaking apart of agglomerated carbon, and the change in particle distribution over short timescales 1 s).

Layered and scrolled nanocomposites with aligned semi-infinite graphene inclusions at the platelet limit

NASA Astrophysics Data System (ADS)

Liu, Pingwei; Jin, Zhong; Katsukis, Georgios; Drahushuk, Lee William; Shimizu, Steven; Shih, Chih-Jen; Wetzel, Eric D.; Taggart-Scarff, Joshua K.; Qing, Bo; Van Vliet, Krystyn J.; Li, Richard; Wardle, Brian L.; Strano, Michael S.

2016-07-01

Two-dimensional (2D) materials can uniquely span the physical dimensions of a surrounding composite matrix in the limit of maximum reinforcement. However, the alignment and assembly of continuous 2D components at high volume fraction remain challenging. We use a stacking and folding method to generate aligned graphene/polycarbonate composites with as many as 320 parallel layers spanning 0.032 to 0.11 millimeters in thickness that significantly increases the effective elastic modulus and strength at exceptionally low volume fractions of only 0.082%. An analogous transverse shear scrolling method generates Archimedean spiral fibers that demonstrate exotic, telescoping elongation at break of 110%, or 30 times greater than Kevlar. Both composites retain anisotropic electrical conduction along the graphene planar axis and transparency. These composites promise substantial mechanical reinforcement, electrical, and optical properties at highly reduced volume fraction.

Layered and scrolled nanocomposites with aligned semi-infinite graphene inclusions at the platelet limit.

PubMed

Liu, Pingwei; Jin, Zhong; Katsukis, Georgios; Drahushuk, Lee William; Shimizu, Steven; Shih, Chih-Jen; Wetzel, Eric D; Taggart-Scarff, Joshua K; Qing, Bo; Van Vliet, Krystyn J; Li, Richard; Wardle, Brian L; Strano, Michael S

2016-07-22

Two-dimensional (2D) materials can uniquely span the physical dimensions of a surrounding composite matrix in the limit of maximum reinforcement. However, the alignment and assembly of continuous 2D components at high volume fraction remain challenging. We use a stacking and folding method to generate aligned graphene/polycarbonate composites with as many as 320 parallel layers spanning 0.032 to 0.11 millimeters in thickness that significantly increases the effective elastic modulus and strength at exceptionally low volume fractions of only 0.082%. An analogous transverse shear scrolling method generates Archimedean spiral fibers that demonstrate exotic, telescoping elongation at break of 110%, or 30 times greater than Kevlar. Both composites retain anisotropic electrical conduction along the graphene planar axis and transparency. These composites promise substantial mechanical reinforcement, electrical, and optical properties at highly reduced volume fraction. Copyright © 2016, American Association for the Advancement of Science.

Clinical Evaluation of a Royal Jelly Supplementation for the Restoration of Dry Eye: A Prospective Randomized Double Blind Placebo Controlled Study and an Experimental Mouse Model

PubMed Central

Inoue, Sachiko; Kawashima, Motoko; Hisamura, Ryuji; Imada, Toshihiro; Izuta, Yusuke; Nakamura, Shigeru; Ito, Masataka; Tsubota, Kazuo

2017-01-01

Background Dry eye is a multifactorial disease characterized by ocular discomfort and visual impairment. Lacrimal gland function has been shown to decrease with aging, a known potent risk factor for dry eye. We have previously found that orally administrated royal jelly (RJ) restored tear secretion in a rat model of dry eye. Methods and Findings We examined the effects of RJ oral administration on dry eye in this prospective, randomized, double-blind, placebo-controlled study. Forty-three Japanese patients aged 20–60 years with subjective dry eye symptoms were randomized to an RJ group (1200 mg/tablet, six tablets daily) or a placebo group for 8 weeks. Keratoconjunctival epithelial damage, tear film break-up time, tear secretion volume, meibum grade, biochemical data, and subjective dry eye symptoms based on a questionnaire were investigated at baseline, and at 4 and 8 weeks after intervention. Adverse events were reported via medical interviews. In the RJ group, tear volume significantly increased after intervention (p = 0.0009). In particular, patients with a baseline Schirmer value of ≤10 mm showed a significant increase compared with baseline volume (p = 0.0005) and volume in the placebo group (p = 0.0051). No adverse events were reported. We also investigated the effect of RJ (300 mg/kg per day) administration using a mouse model of dry eye. Orally repeated administration of RJ preserved tear secretion, potentially through direct activation of the secretory function of the lacrimal glands. Conclusion Our results suggest that RJ improves tear volume in patients with dry eye. Trial Registration Registered NO. the University Hospital Medical Information Network in Japan (UMIN000014446) PMID:28060936

Clinical Evaluation of a Royal Jelly Supplementation for the Restoration of Dry Eye: A Prospective Randomized Double Blind Placebo Controlled Study and an Experimental Mouse Model.

PubMed

Inoue, Sachiko; Kawashima, Motoko; Hisamura, Ryuji; Imada, Toshihiro; Izuta, Yusuke; Nakamura, Shigeru; Ito, Masataka; Tsubota, Kazuo

2017-01-01

Dry eye is a multifactorial disease characterized by ocular discomfort and visual impairment. Lacrimal gland function has been shown to decrease with aging, a known potent risk factor for dry eye. We have previously found that orally administrated royal jelly (RJ) restored tear secretion in a rat model of dry eye. We examined the effects of RJ oral administration on dry eye in this prospective, randomized, double-blind, placebo-controlled study. Forty-three Japanese patients aged 20-60 years with subjective dry eye symptoms were randomized to an RJ group (1200 mg/tablet, six tablets daily) or a placebo group for 8 weeks. Keratoconjunctival epithelial damage, tear film break-up time, tear secretion volume, meibum grade, biochemical data, and subjective dry eye symptoms based on a questionnaire were investigated at baseline, and at 4 and 8 weeks after intervention. Adverse events were reported via medical interviews. In the RJ group, tear volume significantly increased after intervention (p = 0.0009). In particular, patients with a baseline Schirmer value of ≤10 mm showed a significant increase compared with baseline volume (p = 0.0005) and volume in the placebo group (p = 0.0051). No adverse events were reported. We also investigated the effect of RJ (300 mg/kg per day) administration using a mouse model of dry eye. Orally repeated administration of RJ preserved tear secretion, potentially through direct activation of the secretory function of the lacrimal glands. Our results suggest that RJ improves tear volume in patients with dry eye. Registered NO. the University Hospital Medical Information Network in Japan (UMIN000014446).

How Does Definition of Minimum Break Length Affect Objective Measures of Sitting Outcomes Among Office Workers?

PubMed

Kloster, Stine; Danquah, Ida Høgstedt; Holtermann, Andreas; Aadahl, Mette; Tolstrup, Janne Schurmann

2017-01-01

Harmful health effects associated with sedentary behavior may be attenuated by breaking up long periods of sitting by standing or walking. However, studies assess interruptions in sitting time differently, making comparisons between studies difficult. It has not previously been described how the definition of minimum break duration affects sitting outcomes. Therefore, the aim was to address how definitions of break length affect total sitting time, number of sit-to-stand transitions, prolonged sitting periods and time accumulated in prolonged sitting periods among office workers. Data were collected from 317 office workers. Thigh position was assessed with an ActiGraph GT3X+ fixed on the right thigh. Data were exported with varying bout length of breaks. Afterward, sitting outcomes were calculated for the respective break lengths. Absolute numbers of sit-to-stand transitions decreased, and number of prolonged sitting periods and total time accumulated in prolonged sitting periods increased, with increasing minimum break length. Total sitting time was not influenced by varying break length. The definition of minimum break length influenced the sitting outcomes with the exception of total sitting time. A standard definition of break length is needed for comparison and interpretation of studies in the evolving research field of sedentary behavior.

Volcanic stratigraphy of large-volume silicic pyroclastic eruptions during Oligocene Afro-Arabian flood volcanism in Yemen

NASA Astrophysics Data System (ADS)

Peate, Ingrid Ukstins; Baker, Joel A.; Al-Kadasi, Mohamed; Al-Subbary, Abdulkarim; Knight, Kim B.; Riisager, Peter; Thirlwall, Matthew F.; Peate, David W.; Renne, Paul R.; Menzies, Martin A.

2005-12-01

A new stratigraphy for bimodal Oligocene flood volcanism that forms the volcanic plateau of northern Yemen is presented based on detailed field observations, petrography and geochemical correlations. The >1 km thick volcanic pile is divided into three phases of volcanism: a main basaltic stage (31 to 29.7 Ma), a main silicic stage (29.7 to 29.5 Ma), and a stage of upper bimodal volcanism (29.5 to 27.7 Ma). Eight large-volume silicic pyroclastic eruptive units are traceable throughout northern Yemen, and some units can be correlated with silicic eruptive units in the Ethiopian Traps and to tephra layers in the Indian Ocean. The silicic units comprise pyroclastic density current and fall deposits and a caldera-collapse breccia, and they display textures that unequivocally identify them as primary pyroclastic deposits: basal vitrophyres, eutaxitic fabrics, glass shards, vitroclastic ash matrices and accretionary lapilli. Individual pyroclastic eruptions have preserved on-land volumes of up to ˜850 km3. The largest units have associated co-ignimbrite plume ash fall deposits with dispersal areas >1×107 km2 and estimated maximum total volumes of up to 5,000 km3, which provide accurate and precisely dated marker horizons that can be used to link litho-, bio- and magnetostratigraphy studies. There is a marked change in eruption style of silicic units with time, from initial large-volume explosive pyroclastic eruptions producing ignimbrites and near-globally distributed tuffs, to smaller volume (<50 km3) mixed effusive-explosive eruptions emplacing silicic lavas intercalated with tuffs and ignimbrites. Although eruption volumes decrease by an order of magnitude from the first stage to the last, eruption intervals within each phase remain broadly similar. These changes may reflect the initiation of continental rifting and the transition from pre-break-up thick, stable crust supporting large-volume magma chambers, to syn-rift actively thinning crust hosting small-volume magma chambers.

Experimental Study on Longmaxi Shale Breaking Mechanism with Micro-PDC Bit

NASA Astrophysics Data System (ADS)

Wang, Teng; Xiao, Xiaohua; Zhu, Haiyan; Zhao, Jingying; Li, Yuheng; Lu, Ming

2017-10-01

China has abundant shale gas resource, but its geological conditions are complicated. This work sought to find the shale breaking mechanism with the polycrystalline diamond compact (PDC) bit when drilling the shale that is rich in stratification. Therefore, a laboratory-scale drilling device based on a drilling machine is developed. The influences of Longmaxi shale stratification on drilling parameters in the drilling process with micro-PDC bit are investigated. Six groups of drilling experiments with six inclination angles ( β = 0°, 15°, 30°, 45°, 60° and 90°), total thirty-six groups, are carried out. The weight on bit reaches the maximum value at β = 30° and reaches the minimum value at β = 0°. The biggest torque value is at β = 30°, and the smaller torque values are at β = 15°, β = 45° and β = 60°. When the inclination angle is between 30° and 60°, the shale fragmentation volume is larger. The inclination angle β = 0° is beneficial, and β = 15° and β = 60° are detrimental to controlling the drilling direction in the Longmaxi shale gas formation.

Impact of Booster Breaks and Computer Prompts on Physical Activity and Sedentary Behavior Among Desk-Based Workers: A Cluster-Randomized Controlled Trial.

PubMed

Taylor, Wendell C; Paxton, Raheem J; Shegog, Ross; Coan, Sharon P; Dubin, Allison; Page, Timothy F; Rempel, David M

2016-11-17

The 15-minute work break provides an opportunity to promote health, yet few studies have examined this part of the workday. We studied physical activity and sedentary behavior among office workers and compared the results of the Booster Break program with those of a second intervention and a control group to determine whether the Booster Break program improved physical and behavioral health outcomes. We conducted a 3-arm, cluster-randomized controlled trial at 4 worksites in Texas from 2010 through 2013 to compare a group-based, structured Booster Break program to an individual-based computer-prompt intervention and a usual-break control group; we analyzed physiologic, behavioral, and employee measures such as work social support, quality of life, and perceived stress. We also identified consistent and inconsistent attendees of the Booster Break sessions. We obtained data from 175 participants (mean age, 43 y; 67% racial/ethnic minority). Compared with the other groups, the consistent Booster Break attendees had greater weekly pedometer counts (P < .001), significant decreases in sedentary behavior and self-reported leisure-time physical activity (P < .001), and a significant increase in triglyceride concentrations (P = .02) (levels remained within the normal range). Usual-break participants significantly increased their body mass index, whereas Booster Break participants maintained body mass index status during the 6 months. Overall, Booster Break participants were 6.8 and 4.3 times more likely to have decreases in BMI and weekend sedentary time, respectively, than usual-break participants. Findings varied among the 3 study groups; however, results indicate the potential for consistent attendees of the Booster Break intervention to achieve significant, positive changes related to physical activity, sedentary behavior, and body mass index.

Impact of Booster Breaks and Computer Prompts on Physical Activity and Sedentary Behavior Among Desk-Based Workers: A Cluster-Randomized Controlled Trial

PubMed Central

Paxton, Raheem J.; Shegog, Ross; Coan, Sharon P.; Dubin, Allison; Page, Timothy F.; Rempel, David M.

2016-01-01

Introduction The 15-minute work break provides an opportunity to promote health, yet few studies have examined this part of the workday. We studied physical activity and sedentary behavior among office workers and compared the results of the Booster Break program with those of a second intervention and a control group to determine whether the Booster Break program improved physical and behavioral health outcomes. Methods We conducted a 3-arm, cluster-randomized controlled trial at 4 worksites in Texas from 2010 through 2013 to compare a group-based, structured Booster Break program to an individual-based computer-prompt intervention and a usual-break control group; we analyzed physiologic, behavioral, and employee measures such as work social support, quality of life, and perceived stress. We also identified consistent and inconsistent attendees of the Booster Break sessions. Results We obtained data from 175 participants (mean age, 43 y; 67% racial/ethnic minority). Compared with the other groups, the consistent Booster Break attendees had greater weekly pedometer counts (P < .001), significant decreases in sedentary behavior and self-reported leisure-time physical activity (P < .001), and a significant increase in triglyceride concentrations (P = .02) (levels remained within the normal range). Usual-break participants significantly increased their body mass index, whereas Booster Break participants maintained body mass index status during the 6 months. Overall, Booster Break participants were 6.8 and 4.3 times more likely to have decreases in BMI and weekend sedentary time, respectively, than usual-break participants. Conclusion Findings varied among the 3 study groups; however, results indicate the potential for consistent attendees of the Booster Break intervention to achieve significant, positive changes related to physical activity, sedentary behavior, and body mass index. PMID:27854422

Response of Volume Transport through the Taiwan and Tsushima Straits to the Wind Fields in the East China Sea

NASA Astrophysics Data System (ADS)

Matsuno, T.; Liu, C. T.; Fukudome, K.; Chen, H. W.; Ichikawa, K.; Doong, D. J.; Senjyu, T.

2016-02-01

Circulation in the shelf region of the East China Sea is strongly controlled by the volume transport (VT) through the Taiwan Strait (TwS). It is well known that the VT through TwS has a significant seasonal variation, large in summer and small in winter. Based on a time series of the current field obtained by ADCP installed on a ferry boat crossing the TwS, from Keelung to Matsu Island in Taiwan, it had been investigated that the seasonal variations have a good correlation with the local wind around the TwS. The VT through the TwS had been compared with that through Tsushima Strait (TsS), and the results using the data from 2009 to 2012 were presented in the last OSM. In this study the monitoring data were extended further to 2014 and the difference of VTs between TwS and TsS was compared with wind fields and Ekman transport for not only seasonal variation but also shorter time scale variations. Ekman transport across the shelf break with time scales shorter than one month has a good correlation with the difference of VTs between TwS and TsS, that is, net transport across the shelf break of the East China Sea. The correlation is much better with VT through TwS rather than through TsS. Onshoreward net transport due to the Ekman transport may decrease the VT through TwS, which means that the VT through TwS is not only related to the local wind but also wind field over the East China Sea.

The Checkpoint Kinase 1 Inhibitor Prexasertib Induces Regression of Preclinical Models of Human Neuroblastoma.

PubMed

Lowery, Caitlin D; VanWye, Alle B; Dowless, Michele; Blosser, Wayne; Falcon, Beverly L; Stewart, Julie; Stephens, Jennifer; Beckmann, Richard P; Bence Lin, Aimee; Stancato, Louis F

2017-08-01

Purpose: Checkpoint kinase 1 (CHK1) is a key regulator of the DNA damage response and a mediator of replication stress through modulation of replication fork licensing and activation of S and G 2 -M cell-cycle checkpoints. We evaluated prexasertib (LY2606368), a small-molecule CHK1 inhibitor currently in clinical testing, in multiple preclinical models of pediatric cancer. Following an initial assessment of prexasertib activity, this study focused on the preclinical models of neuroblastoma. Experimental Design: We evaluated the antiproliferative activity of prexasertib in a panel of cancer cell lines; neuroblastoma cell lines were among the most sensitive. Subsequent Western blot and immunofluorescence analyses measured DNA damage and DNA repair protein activation. Prexasertib was investigated in several cell line-derived xenograft mouse models of neuroblastoma. Results: Within 24 hours, single-agent prexasertib promoted γH2AX-positive double-strand DNA breaks and phosphorylation of DNA damage sensors ATM and DNA-PKcs, leading to neuroblastoma cell death. Knockdown of CHK1 and/or CHK2 by siRNA verified that the double-strand DNA breaks and cell death elicited by prexasertib were due to specific CHK1 inhibition. Neuroblastoma xenografts rapidly regressed following prexasertib administration, independent of starting tumor volume. Decreased Ki67 and increased immunostaining of endothelial and pericyte markers were observed in xenografts after only 6 days of exposure to prexasertib, potentially indicating a swift reduction in tumor volume and/or a direct effect on tumor vasculature. Conclusions: Overall, these data demonstrate that prexasertib is a specific inhibitor of CHK1 in neuroblastoma and leads to DNA damage and cell death in preclinical models of this devastating pediatric malignancy. Clin Cancer Res; 23(15); 4354-63. ©2017 AACR . ©2017 American Association for Cancer Research.

Sea-State Dependence of Aerosol Concentration in the Marine Atmospheric Boundary Layer

NASA Astrophysics Data System (ADS)

Lenain, L.; Melville, W. K.

2016-02-01

While sea spray aerosols represent a large portion of the aerosols present in the marine environment, and despite evidence of the importance of surface wave and wave-breaking related processes in the coupling of the ocean with the atmosphere, sea spray source generation functions are traditionally parameterized by the wind speed at 10m. It is clear that unless the wind and wave field are fully developed, the source function will be a function of both wind and wave parameters. In this study, we report on an air-sea interaction experiment, the ONR phase-resolved High-Resolution Air-Sea Interaction experiments (HIRES), conducted off the coast of Northern California in June 2010. Detailed measurements of aerosol number concentration in the Marine Atmospheric Boundary Layer (MABL), at altitudes ranging from as low as 30m and up to 800m AMSL over a broad range of environmental conditions (significant wave height, Hs, of 2 to 4.5m and wind speed at 10m height, U10, of 10 to 18 m/s) collected from an instrumented research aircraft, are presented. Aerosol number densities and volume are computed over a range of particle diameters from 0.1 to 200 µm, while the surface conditions, i.e. significant wave height, moments of the breaker length distribution Λ(c), and wave breaking dissipation, were measured by a suite of electro-optical sensors that included the NASA Airborne Topographic Mapper (ATM). The sea-state dependence of the aerosol concentration in the MABL is evident, ultimately stressing the need to incorporate wave and wave kinematics in the spray source generation functions that are traditionally primarily parameterized by surface winds. A scaling of the measured aerosol volume distribution by wave and atmospheric state variables is proposed.

Building a Consensus Forecast for Crude Oil Prices

DTIC Science & Technology

2006-03-01

Middle East ( Cremer , 1991). As the world became dependant on cheap oil found in the Middle East, the underlying market was changing. Initially...governments in an effort to break into the market ( Cremer , 1991). During this time, Middle Eastern countries received a royalty on the oil produced within...their borders. This meant that government revenues were tied to volume, regardless of price ( Cremer , 1991). But in the 1950s the oil companies

Fwd: Opportunities Lost--How New York City Got Derailed on the Way to School Reform. Volume: I, Number: 3. Arresting Insights in Education

ERIC Educational Resources Information Center

Stern, Sol

2004-01-01

Mayor Michael Bloomberg gave his first hint about his plans for reforming the New York City school system on Martin Luther King Day in January 2003. Mayor Bloomberg did not offer a single excuse for the disastrous state of the city's schools. Nor did he attribute that failure to poverty or racism. Breaking with 50 years of liberal political…

Low Frequency Ocean Ambient Noise: Measurements and Theory,

DTIC Science & Technology

1987-12-14

entrained gas bubbles which result from wave breaking and which are forced by intense velocity of the gravity-capil- lary waves. For wind speeds with a...ternal force acting on the volume and has a dipole character. These two terms could be important in the incorporation of entrained bubble oscil- lation and...Applied Research Lab, Penn. State Univ., State College, PA 16804 Mellen, R.H., 1987: private communication. Minnaert, M., 1933: ’ Musical Air-Bubbles

Digital Tracking and Control of Retinal Images

DTIC Science & Technology

1993-01-01

induced retinal lesions are used to treat a variety of eye diseases such as diabetic retinopathy and retinal tears or breaks. Both the location and...one second and typical treatment for a disease such as diabetic retinopathy requires as many as 2000 lesions per eye. This type of tedious task is...Oxygenation and Laser Treatment in Patients with Diabetic Retinopathy ", American Journal of Ophthalmology, Volume 113, January 1992, pp 36 - 38. [21

Surf Zone Currents. Volume I. State of Knowledge.

DTIC Science & Technology

1982-09-01

elevation above an arbitrary datum a angle between wave crest and bottom contour a angle between wave crest and the shoreline . ab angle between breaking...b- Note that neglecting wave setup, refraction and for small ab , equation (74) reduces to that employed by Longuet-Higgins (eq. 48). These researchers...28. As ab o (Note that ab = o means theory reduces to original order (zero order) solution given by Longuet-Higgins, 1970, the triangular solution is

POW/MIA Issues. Volume 1. The Korean War

DTIC Science & Technology

1994-01-01

individuals. Forensic analyses suggest that these remains are not American, thus this re- port makes no references to alleged "repatriations." There is...The U.S. gov- ernment funded ground-breaking basic research in forensic sciences in an effort to identify remains with a high degree of certainty. In...application of sound psychological and educational techniques. This confirms that drugs and hypnosis were not used and physical torture was not employed in any

American Security and the International Energy Situation. Volume 1. Introduction and Summary

DTIC Science & Technology

1975-04-15

Financial Security 28 Timely Energy Supply Enhancement 31 Prospects for a Price Break M Concluding Remarks ’♦S II. World Energy Interdependence...likely to experience as the level of social and political chaos rises under the pressures of economic contraction, financial hemorrhage, and pervasive...and Consolidated Edison’s punned storage facility planned for Storm King). Often, energy projects are delayed from the very beginning by vocal

Making and breaking bridges in a Pickering emulsion.

PubMed

French, David J; Taylor, Phil; Fowler, Jeff; Clegg, Paul S

2015-03-01

Particle bridges form in Pickering emulsions when the oil-water interfacial area generated by an applied shear is greater than that which can be stabilised by the available particles and the particles have a slight preference for the continuous phase. They can subsequently be broken by low shear or by modifying the particle wettability. We have developed a model oil-in-water system for studying particle bridging in Pickering emulsions stabilised by fluorescent Stöber silica. A mixture of dodecane and isopropyl myristate was used as the oil phase. We have used light scattering and microscopy to study the degree to which emulsions are bridged, and how this is affected by parameters including particle volume fraction, particle wettability and shear rate. We have looked for direct evidence of droplets sharing particles using freeze fracture scanning electron microscopy. We have created strongly aggregating Pickering emulsions using our model system. This aggregating state can be accessed by varying several different parameters, including particle wettability and particle volume fraction. Particles with a slight preference for the continuous phase are required for bridging to occur, and the degree of bridging increases with increasing shear rate but decreases with increasing particle volume fraction. Particle bridges can subsequently be removed by applying low shear or by modifying the particle wettability. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

NASA Astrophysics Data System (ADS)

Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

2016-04-01

In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

Task-specific feature extraction and classification of fMRI volumes using a deep neural network initialized with a deep belief network: Evaluation using sensorimotor tasks

PubMed Central

Jang, Hojin; Plis, Sergey M.; Calhoun, Vince D.; Lee, Jong-Hwan

2016-01-01

Feedforward deep neural networks (DNN), artificial neural networks with multiple hidden layers, have recently demonstrated a record-breaking performance in multiple areas of applications in computer vision and speech processing. Following the success, DNNs have been applied to neuroimaging modalities including functional/structural magnetic resonance imaging (MRI) and positron-emission tomography data. However, no study has explicitly applied DNNs to 3D whole-brain fMRI volumes and thereby extracted hidden volumetric representations of fMRI that are discriminative for a task performed as the fMRI volume was acquired. Our study applied fully connected feedforward DNN to fMRI volumes collected in four sensorimotor tasks (i.e., left-hand clenching, right-hand clenching, auditory attention, and visual stimulus) undertaken by 12 healthy participants. Using a leave-one-subject-out cross-validation scheme, a restricted Boltzmann machine-based deep belief network was pretrained and used to initialize weights of the DNN. The pretrained DNN was fine-tuned while systematically controlling weight-sparsity levels across hidden layers. Optimal weight-sparsity levels were determined from a minimum validation error rate of fMRI volume classification. Minimum error rates (mean ± standard deviation; %) of 6.9 (± 3.8) were obtained from the three-layer DNN with the sparsest condition of weights across the three hidden layers. These error rates were even lower than the error rates from the single-layer network (9.4 ± 4.6) and the two-layer network (7.4 ± 4.1). The estimated DNN weights showed spatial patterns that are remarkably task-specific, particularly in the higher layers. The output values of the third hidden layer represented distinct patterns/codes of the 3D whole-brain fMRI volume and encoded the information of the tasks as evaluated from representational similarity analysis. Our reported findings show the ability of the DNN to classify a single fMRI volume based on the extraction of hidden representations of fMRI volumes associated with tasks across multiple hidden layers. Our study may be beneficial to the automatic classification/diagnosis of neuropsychiatric and neurological diseases and prediction of disease severity and recovery in (pre-) clinical settings using fMRI volumes without requiring an estimation of activation patterns or ad hoc statistical evaluation. PMID:27079534

Task-specific feature extraction and classification of fMRI volumes using a deep neural network initialized with a deep belief network: Evaluation using sensorimotor tasks.

PubMed

Jang, Hojin; Plis, Sergey M; Calhoun, Vince D; Lee, Jong-Hwan

2017-01-15

Feedforward deep neural networks (DNNs), artificial neural networks with multiple hidden layers, have recently demonstrated a record-breaking performance in multiple areas of applications in computer vision and speech processing. Following the success, DNNs have been applied to neuroimaging modalities including functional/structural magnetic resonance imaging (MRI) and positron-emission tomography data. However, no study has explicitly applied DNNs to 3D whole-brain fMRI volumes and thereby extracted hidden volumetric representations of fMRI that are discriminative for a task performed as the fMRI volume was acquired. Our study applied fully connected feedforward DNN to fMRI volumes collected in four sensorimotor tasks (i.e., left-hand clenching, right-hand clenching, auditory attention, and visual stimulus) undertaken by 12 healthy participants. Using a leave-one-subject-out cross-validation scheme, a restricted Boltzmann machine-based deep belief network was pretrained and used to initialize weights of the DNN. The pretrained DNN was fine-tuned while systematically controlling weight-sparsity levels across hidden layers. Optimal weight-sparsity levels were determined from a minimum validation error rate of fMRI volume classification. Minimum error rates (mean±standard deviation; %) of 6.9 (±3.8) were obtained from the three-layer DNN with the sparsest condition of weights across the three hidden layers. These error rates were even lower than the error rates from the single-layer network (9.4±4.6) and the two-layer network (7.4±4.1). The estimated DNN weights showed spatial patterns that are remarkably task-specific, particularly in the higher layers. The output values of the third hidden layer represented distinct patterns/codes of the 3D whole-brain fMRI volume and encoded the information of the tasks as evaluated from representational similarity analysis. Our reported findings show the ability of the DNN to classify a single fMRI volume based on the extraction of hidden representations of fMRI volumes associated with tasks across multiple hidden layers. Our study may be beneficial to the automatic classification/diagnosis of neuropsychiatric and neurological diseases and prediction of disease severity and recovery in (pre-) clinical settings using fMRI volumes without requiring an estimation of activation patterns or ad hoc statistical evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors affecting fuel break effectiveness in the control of large fires on the Los Padres National Forest, California

USGS Publications Warehouse

Syphard, Alexandra D.; Keeley, Jon E.; Brennan, Teresa J.

2011-01-01

As wildfires have increased in frequency and extent, so have the number of homes developed in the wildland-urban interface. In California, the predominant approach to mitigating fire risk is construction of fuel breaks, but there has been little empirical study of their role in controlling large fires.We constructed a spatial database of fuel breaks on the Los Padres National Forest in southern California to better understand characteristics of fuel breaks that affect the behaviour of large fires and to map where fires and fuel breaks most commonly intersect. We evaluated whether fires stopped or crossed over fuel breaks over a 28-year period and compared the outcomes with physical characteristics of the sites, weather and firefighting activities during the fire event. Many fuel breaks never intersected fires, but others intersected several, primarily in historically fire-prone areas. Fires stopped at fuel breaks 46% of the time, almost invariably owing to fire suppression activities. Firefighter access to treatments, smaller fires and longer fuel breaks were significant direct influences, and younger vegetation and fuel break maintenance indirectly improved the outcome by facilitating firefighter access. This study illustrates the importance of strategic location of fuel breaks because they have been most effective where they provided access for firefighting activities.

Refined Source Terms in Wave Watch 3 with Wave Breaking and Sea Spray Forecasts

DTIC Science & Technology

2016-08-05

Farmer at IOS Canada involved a novel scale analysis of breaking waves. This was motivated by the results of the model study of wave breaking onset by...timely development that needs careful examination. 4.11 Highlights of the SPANDEX study SPANDEX, the Spray Production and Dynamics Experiment, is...speed alone. To accomplish this goal, a parallel laboratory study (SPANDEX II) was undertaken to parameterize sea spray flux dependences on breaking

Rest break organization in geriatric care and turnover: a multimethod cross-sectional study.

PubMed

Wendsche, Johannes; Hacker, Winfried; Wegge, Jürgen; Schrod, Nadine; Roitzsch, Katharina; Tomaschek, Anne; Kliegel, Matthias

2014-09-01

Various determinants of nurses' work motivation and turnover behavior have been examined in previous studies. In this research, we extend this work by investigating the impact of care setting (nursing homes vs. home care services) and the important role of rest break organization. We aimed to identify direct and indirect linkages between geriatric care setting, rest break organization, and registered nurses' turnover assessed over a period of one year. We designed a multimethod cross-sectional study. 80 nursing units (n=45 nursing homes, n=35 home care) in 51 German geriatric care services employing 597 registered nurses. We gathered documentary, interview, and observational data about the organization of rest breaks, registered nurses' turnover, and additional organizational characteristics (type of ownership, location, nursing staff, clients, and client-to-staff-ratio). The findings show that the rest break system in geriatric nursing home units is more regularly as well as collectively organized and causes less unauthorized rest breaks than in home care units. Moreover, the feasibility of collective rest breaks was, as predicted, negatively associated with registered nurses' turnover and affected indirectly the relation between care setting and registered nurses' turnover. Care setting, however, had no direct impact on turnover. Furthermore, registered nurses' turnover was higher in for-profit care units than in public or non-profit units. This study reveals significant differences in rest break organization as a function of geriatric care setting and highlights the role of collective rest breaks for nursing staff retention. Our study underlines the integration of organizational context variables and features of rest break organization for the analysis of nursing turnover. Copyright © 2014 Elsevier Ltd. All rights reserved.

Numerical study on interaction of local air cooler with stratified hydrogen cloud in a large vessel

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

Liang, Z.; Andreani, M.

2012-07-01

Within the framework of the ERCOSAM project, planning calculations are performed to examine sensitivity parameters that can affect the break-up (erosion) of a helium layer by mitigation devices (i.e., cooler, spray, or Passive Autocatalytic Recombiner - PAR). This paper reports the GOTHIC analysis results for the cooler tests to be performed in the PANDA facility. The cooler elevation and geometry, helium layer thickness, steam distribution in the vessel, and the vessel geometry (inter-connected multi-compartments versus a single volume) on the erosion process as well as the cooling capacity are studied. This analysis is valuable because only a limited number ofmore » conditions will be examined in the planned experiments. The study provides a useful understanding of the interaction of a cooler with a stratified atmosphere. (authors)« less

Retaining the general practitioner workforce in England: what matters to GPs? A cross-sectional study.

PubMed

Dale, Jeremy; Potter, Rachel; Owen, Katherine; Parsons, Nicholas; Realpe, Alba; Leach, Jonathan

2015-10-16

The general practice (GP) workforce in England is in crisis, reflected in increasing rates of early retirement and intentions to reduce hours of working. This study aimed to investigate underlying factors and how these might be mitigated. GPs in central England were invited to participate in an on-line survey exploring career plans and views and experiences of work-related pressures. Quantitative data were analysed using logistic regression analysis and principal components analysis. Qualitative data were analysed using a thematic framework approach. Of 1,192 GPs who participated, 978 (82.0 %) stated that they intend to leave general practice, take a career break and/or reduce clinical hours of work within the next five years. This included 488 (41.9 %) who intend to leave practice, and almost a quarter (279; 23.2 %) intending to take a career break. Only 67 (5.6 %) planned to increase their hours of clinical work. For participants planning to leave practice, the issues that most influenced intentions were volume and intensity of workload, time spent on "unimportant tasks", introduction of seven-day working and lack of job satisfaction. Four hundred fifty five participants responded to open questions (39128 words in total). The main themes were the cumulative impact of work-related pressures, the changing and growing nature of the workload, and the consequent stress. Reducing workload intensity, workload volume, administrative activities, with increased time for patient care, no out-of-hour commitments, more flexible working conditions and greater clinical autonomy were identified as the most important requirements to address the workforce crisis. In addition, incentive payments, increased pay and protected time for education and training were also rated as important. New models of professionalism and organisational arrangements may be needed to address the issues described here. Without urgent action, the GP workforce crisis in England seems set to worsen.

Waste Heat Approximation for Understanding Dynamic Compression in Nature and Experiments

NASA Astrophysics Data System (ADS)

Jeanloz, R.

2015-12-01

Energy dissipated during dynamic compression quantifies the residual heat left in a planet due to impact and accretion, as well as the deviation of a loading path from an ideal isentrope. Waste heat ignores the difference between the pressure-volume isentrope and Hugoniot in approximating the dissipated energy as the area between the Rayleigh line and Hugoniot (assumed given by a linear dependence of shock velocity on particle velocity). Strength and phase transformations are ignored: justifiably, when considering sufficiently high dynamic pressures and reversible transformations. Waste heat mis-estimates the dissipated energy by less than 10-20 percent for volume compressions under 30-60 percent. Specific waste heat (energy per mass) reaches 0.2-0.3 c02 at impact velocities 2-4 times the zero-pressure bulk sound velocity (c0), its maximum possible value being 0.5 c02. As larger impact velocities are implied for typical orbital velocities of Earth-like planets, and c02 ≈ 2-30 MJ/kg for rock, the specific waste heat due to accretion corresponds to temperature rises of about 3-15 x 103 K for rock: melting accompanies accretion even with only 20-30 percent waste heat retained. Impact sterilization is similarly quantified in terms of waste heat relative to the energy required to vaporize H2O (impact velocity of 7-8 km/s, or 4.5-5 c0, is sufficient). Waste heat also clarifies the relationship between shock, multi-shock and ramp loading experiments, as well as the effect of (static) pre-compression. Breaking a shock into 2 steps significantly reduces the dissipated energy, with minimum waste heat achieved for two equal volume compressions in succession. Breaking a shock into as few as 4 steps reduces the waste heat to within a few percent of zero, documenting how multi-shock loading approaches an isentrope. Pre-compression, being less dissipative than an initial shock to the same strain, further reduces waste heat. Multi-shock (i.e., high strain-rate) loading of pre-compressed samples may thus offer the closest approach to an isentrope, and therefore the most extreme compression at which matter can be studied at the "warm" temperatures of planetary interiors.

Stop and revive? The effectiveness of nap and active rest breaks for reducing driver sleepiness.

PubMed

Watling, Christopher N; Smith, Simon S; Horswill, Mark S

2014-11-01

The purpose of this study was to compare the effects of two commonly utilized sleepiness countermeasures: a nap break and an active rest break. The effects of the countermeasures were evaluated by physiological (EEG), subjective, and driving performance measures. Participants completed 2 h of simulated driving, followed by a 15-min nap break or a 15-min active rest break, then completed the final hour of simulated driving. The nap break reduced EEG and subjective sleepiness. The active rest break did not reduce EEG sleepiness, with sleepiness levels eventually increasing, and resulted in an immediate reduction of subjective sleepiness. No difference was found between the two breaks for the driving performance measure. The immediate reduction of subjective sleepiness after the active rest break could leave drivers with erroneous perceptions of their sleepiness, particularly with increases of physiological sleepiness after the break. Copyright © 2014 Society for Psychophysiological Research.

Effects of school breaks on influenza-like illness incidence in a temperate Chinese region: an ecological study from 2008 to 2015.

PubMed

Chu, Yanhui; Wu, Zhenyu; Ji, Jiayi; Sun, Jingyi; Sun, Xiaoyu; Qin, Guoyou; Qin, Jingning; Xiao, Zheng; Ren, Jian; Qin, Di; Zheng, Xueying; Wang, Xi-Ling

2017-03-06

To assess the effects of winter/summer school breaks on occurrences of influenza-like illness (ILI). We jointly analysed ILI surveillance data with the timing of school breaks in a temperate district in Beijing, China from 2008 to 2015. ILI incidence rate ratios (IRRs) of schoolchildren (5-14 and 15-24 years of age) to adults (25-59 and >60 years of age) were used to measure the age shift of ILI incidence before, during and after the 4-week winter/7-week summer breaks. Serfling-based Poisson regression model with adjustment for unmeasured confounders was built to further assess the effect of winter school breaks. ILI incidences were consistently lower during winter breaks than before winter breaks for all age groups. IRRs of younger schoolchildren aged 5-14 to adults were higher during winter school breaks than before breaks, while the opposite was true for the IRRs of older schoolchildren aged 15-24 to adults. Schoolchildren-to-adults IRRs during summer breaks were significantly lower than before or after school breaks (p<0.001). Both winter and summer breaks were associated with reductions of ILI incidences among schoolchildren and adults. Our study contributes additional evidence on the effects of school breaks on ILI incidence, suggesting school closure could be effective in controlling influenza transmission in developing countries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Distributions of Low- and High-LET Radiation-Induced Breaks in Chromosomes are Associated with Inter- and Intrachromosome Exchanges

NASA Technical Reports Server (NTRS)

Hada, Megumi; Zhang, Ye; Feiveson, Alan; Cucinotta, Francis A.; Wu, Honglu

2010-01-01

To study the breakpoint along the length of the chromosome induced by low- and high-LET radiations, we exposed human epithelial cells in vitro to Cs-137 rays at both low and high dose rates, secondary neutrons at a low dose rate, and 600 MeV/u Fe ions at a high dose rate. The location of the breaks was identified using the multicolor banding in situ hybridization (mBAND) that paints Chromosome 3 in 23 different colored bands. The breakpoint distributions were found to be similar between rays of low and high dose rates and between the two high-LET radiation types. Detailed analysis of the chromosome break ends involved in inter- and intrachromosome exchanges revealed that only the break ends participating in interchromosome exchanges contributed to the hot spots found for low-LET. For break ends participating in intrachromosome exchanges, the distributions for all four radiation scenarios were similar with clusters of breaks found in three regions. Analysis of the locations of the two break ends in Chromosome 3 that joined to form an intrachromosome exchange demonstrated that two breaks with a greater genomic separation may be more likely to rejoin than two closer breaks, indicating that chromatin folding can play an important role in the rejoining of chromosome breaks. Our study demonstrated that the gene-rich regions do not necessarily contain more breaks. The breakpoint distribution depends more on the likelihood that a break will join with another break in the same chromosome or in a different chromosome.

Matrix elements of Δ B =0 operators in heavy hadron chiral perturbation theory

NASA Astrophysics Data System (ADS)

Lee, Jong-Wan

2015-05-01

We study the light-quark mass and spatial volume dependence of the matrix elements of Δ B =0 four-quark operators relevant for the determination of Vu b and the lifetime ratios of single-b hadrons. To this end, one-loop diagrams are computed in the framework of heavy hadron chiral perturbation theory with partially quenched formalism for three light-quark flavors in the isospin limit; flavor-connected and -disconnected diagrams are carefully analyzed. These calculations include the leading light-quark flavor and heavy-quark spin symmetry breaking effects in the heavy hadron spectrum. Our results can be used in the chiral extrapolation of lattice calculations of the matrix elements to the physical light-quark masses and to infinite volume. To provide insight on such chiral extrapolation, we evaluate the one-loop contributions to the matrix elements containing external Bd, Bs mesons and Λb baryon in the QCD limit, where sea and valence quark masses become equal. In particular, we find that the matrix elements of the λ3 flavor-octet operators with an external Bd meson receive the contributions solely from connected diagrams in which current lattice techniques are capable of precise determination of the matrix elements. Finite volume effects are at most a few percent for typical lattice sizes and pion masses.

High Frontier: The Journal for Space & Missile Professionals. Volume 2, Number 3

DTIC Science & Technology

2006-04-01

of businesses that do not have a disaster plan go out of business after a major loss like a fire, a break-in, or a storm.”2 Gartner Dataquest...information exchange between and across all echelons of com- mand and control, logistics, and intelligence , surveillance, and reconnaissance (ISR...swiftly process, manage, and fuse intelligence from across a variety of sources in order to reduce information cycle timelines and thus shorten the

Naval War College Review. Volume 66, Number 2, Spring 2013

DTIC Science & Technology

2013-01-01

ring strait to provide trade security. No more than fifty-two nautical miles wide, the bering strait, which separates alaska and russia, was...breaking the tyranny of wind and weather. soon superior navies would be able to enforce blockades in weather fair and foul, making it more dif- ficult for...privateers to slip out of blockaded ports and, even more to the point, making it improbable that captured vessels could be brought safely into

Naval War College Review. Volume 60, Number 4, Autumn 2007

DTIC Science & Technology

2007-01-01

equates to $14.4 billion. Eric J. Labs, Resource Implications of the Navy’s 313-Ship Plan (Washington, D.C.: Congressional Bud- get Office, 16... Layton , citing Agawa’s ver- sion of an encounter, contributed an additional scenario in his “And I Was There”: Pearl Harbor and Midway—Breaking the...Secrets.4 Layton labors to ad- vance several possible explanations for mysterious radio signals detected by a ra- dio operator aboard Lurline, a Matson

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5-18 eV) electron interactions with DNA.

PubMed

Rezaee, Mohammad; Hunting, Darel J; Sanche, Léon

2014-07-01

The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Absorbed dose and stopping cross section for the Auger electrons of 5-18 eV emitted by(125)I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure-response curves for induction of DNA strand breaks. For a single decay of(125)I within DNA, the Auger electrons of 5-18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm(3) volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide.

Adaptive finite volume methods with well-balanced Riemann solvers for modeling floods in rugged terrain: Application to the Malpasset dam-break flood (France, 1959)

USGS Publications Warehouse

George, D.L.

2011-01-01

The simulation of advancing flood waves over rugged topography, by solving the shallow-water equations with well-balanced high-resolution finite volume methods and block-structured dynamic adaptive mesh refinement (AMR), is described and validated in this paper. The efficiency of block-structured AMR makes large-scale problems tractable, and allows the use of accurate and stable methods developed for solving general hyperbolic problems on quadrilateral grids. Features indicative of flooding in rugged terrain, such as advancing wet-dry fronts and non-stationary steady states due to balanced source terms from variable topography, present unique challenges and require modifications such as special Riemann solvers. A well-balanced Riemann solver for inundation and general (non-stationary) flow over topography is tested in this context. The difficulties of modeling floods in rugged terrain, and the rationale for and efficacy of using AMR and well-balanced methods, are presented. The algorithms are validated by simulating the Malpasset dam-break flood (France, 1959), which has served as a benchmark problem previously. Historical field data, laboratory model data and other numerical simulation results (computed on static fitted meshes) are shown for comparison. The methods are implemented in GEOCLAW, a subset of the open-source CLAWPACK software. All the software is freely available at. Published in 2010 by John Wiley & Sons, Ltd.

Break the "wall" and become creative: Enacting embodied metaphors in virtual reality.

PubMed

Wang, Xinyue; Lu, Kelong; Runco, Mark A; Hao, Ning

2018-07-01

This study investigated whether the experience of "breaking the walls", the embodiment of the metaphor "breaking the rules", could enhance creative performance. The virtual reality technology was used to simulate the scenario where participants could "break the walls" while walking in a corridor. Participants were asked to solve the creativity-demanding problems (ie., alternative uses tasks, AUT) in either the "break" condition in which they had to break the walls to move forward in VR, or the "no-break" condition where no barrier walls would appear. Results showed higher AUT originality and AUT fluency in the "break" condition than in the "no-break" condition. Moreover, the effects of "breaking the walls" on AUT originality were fully mediated by cognitive flexibility and persistence. These findings may indicate that enacting metaphors such as "breaking the rules" contribute to creative performance. The enhanced cognitive flexibility and persistence may account for the benefits. Copyright © 2018 Elsevier Inc. All rights reserved.

HVOSM Studies of Cross-Slope Break on Highway Curves. Phase II Task C

DOT National Transportation Integrated Search

1982-05-01

This research was conducted to investigate the operational effects of cross-slope breaks on highway curves. These breaks are created by the superelevation of the traveled way and the adverse shoulder slope. HVOSM simulation studies were performed on ...

Umbilical Deployment Device

NASA Technical Reports Server (NTRS)

Shafer, Michael W.; Gallon, John C.; Rivellini, Tommaso P.

2011-01-01

The landing scheme for NASA's next-generation Mars rover will encompass a novel landing technique (see figure). The rover will be lowered from a rocket-powered descent stage and then placed onto the surface while hanging from three bridles. Communication between the rover and descent stage will be maintained through an electrical umbilical cable, which will be deployed in parallel with structural bridles. The -inch (13-mm) umbilical cable contains a Kevlar rope core, around which wires are wrapped to create a cable. This cable is helically coiled between two concentric truncated cones. It is deployed by pulling one end of the cable from the cone. A retractable mechanism maintains tension on the cable after deployment. A break-tie tethers the umbilical end attached to the rover even after the cable is cut after touchdown. This break-tie allows the descent stage to develop some velocity away from the rover prior to the cable releasing from the rover deck, then breaks away once the cable is fully extended. The descent stage pulls the cable up so that recontact is not made. The packaging and deployment technique can store a long length of cable in a relatively small volume while maintaining compliance with the minimum bend radius requirement for the cable being deployed. While the packaging technique could be implemented without the use of break-ties, they were needed in this design due to the vibratory environment and the retraction required by the cable. The break-ties used created a series of load-spikes in the deployment signature. The load spikes during the deployment of the initial three coils of umbilical showed no increase between the different temperature trials. The cold deployment did show an increased load requirement for cable extraction in the region where no break-ties were used. This increase in cable drag was superimposed on the loads required to rupture the last set of break-ties, and as such, these loads saw significant increase when compared to their ambient counterparts. While the loads showed spikes of high magnitude, they were of short duration. Because of this, neither the deployment of the rover, nor the motion of the descent stage, would be adversely affected. In addition, the umbilical was found to have a maximum of 1.2 percent chance for recontact with the ultra-high frequency antenna due to the large margin of safety built in.

Effect of ionizing radiation on the physical biology of head and neck squamous cell carcinoma cells.

PubMed

Baker-Groberg, Sandra M; Bornstein, Sophia; Zilberman-Rudenko, Jevgenia; Schmidt, Mark; Tormoen, Garth W; Kernan, Casey; Thomas, Charles R; Wong, Melissa H; Phillips, Kevin G; McCarty, Owen J T

2015-09-01

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer worldwide. Although there are numerous treatment options for HNSCC, such as surgery, cytotoxic chemotherapy, molecularly targeted systemic therapeutics, and radiotherapy, overall survival has not significantly improved in the last 50 years. This suggests a need for a better understanding of how these cancer cells respond to current treatments in order to improve treatment paradigms. Ionizing radiation (IR) promotes cancer cell death through the creation of cytotoxic DNA lesions, including single strand breaks, base damage, crosslinks, and double strand breaks (DSBs). As unrepaired DSBs are the most cytotoxic DNA lesion, defining the downstream cellular responses to DSBs are critical for understanding the mechanisms of tumor cell responses to IR. The effects of experimental IR on HNSCC cells beyond DNA damage in vitro are ill-defined. Here we combined label-free, quantitative phase and fluorescent microscopy to define the effects of IR on the dry mass and volume of the HNSCC cell line, UM-SCC-22A. We quantified nuclear and cytoplasmic subcellular density alterations resulting from 8 Gy X-ray IR and correlated these signatures with DNA and γ-H2AX expression patterns. This study utilizes a synergistic imaging approach to study both biophysical and biochemical alterations in cells following radiation damage and will aid in future understanding of cellular responses to radiation therapy.

Characterizing Droplet Formation from Non-Linear Slosh in a Propellant Tank

NASA Technical Reports Server (NTRS)

Brodnick, Jacob; Yang, Hong; West, Jeffrey

2015-01-01

The Fluid Dynamics Branch (ER42) at the Marshall Space Flight Center (MSFC) was tasked with characterizing the formation and evolution of liquid droplets resulting from nonlinear propellant slosh in a storage tank. Lateral excitation of propellant tanks can produce high amplitude nonlinear slosh waves through large amplitude excitations and or excitation frequencies near a resonance frequency of the tank. The high amplitude slosh waves become breaking waves upon attaining a certain amplitude or encountering a contracting geometry such as the upper dome section of a spherical tank. Inherent perturbations in the thinning regions of breaking waves result in alternating regions of high and low pressure within the fluid. Droplets form once the force from the local pressure differential becomes larger than the force maintaining the fluid interface shape due to surface tension. Droplets released from breaking waves in a pressurized tank may lead to ullage collapse given the appropriate conditions due to the increased liquid surface area and thus heat transfer between the fluids. The goal of this project is to create an engineering model that describes droplet formation as a function of propellant slosh for use in the evaluation of ullage collapse during a sloshing event. The Volume of Fluid (VOF) model in the production level Computational Fluid Dynamics (CFD) code Loci-Stream was used to predict droplet formation from breaking waves with realistic surface tension characteristics. Various excitation frequencies and amplitudes were investigated at multiple fill levels for a single storage tank to create the engineering model of droplet formation from lateral propellant slosh.

Laboratory Study of the Displacement Coalbed CH4 Process and Efficiency of CO2 and N2 Injection

PubMed Central

Wang, Liguo; Wang, Yongkang

2014-01-01

ECBM displacement experiments are a direct way to observe the gas displacement process and efficiency by inspecting the produced gas composition and flow rate. We conducted two sets of ECBM experiments by injecting N2 and CO2 through four large parallel specimens (300 × 50 × 50 mm coal briquette). N2 or CO2 is injected at pressures of 1.5, 1.8, and 2.2 MPa and various crustal stresses. The changes in pressure along the briquette and the concentration of the gas mixture flowing out of the briquette were analyzed. Gas injection significantly enhances CBM recovery. Experimental recoveries of the original extant gas are in excess of 90% for all cases. The results show that the N2 breakthrough occurs earlier than the CO2 breakthrough. The breakthrough time of N2 is approximately 0.5 displaced volumes. Carbon dioxide, however, breaks through at approximately 2 displaced volumes. Coal can adsorb CO2, which results in a slower breakthrough time. In addition, ground stress significantly influences the displacement effect of the gas injection. PMID:24741346

Simulation of breaking waves using the high-order spectral method with laboratory experiments: wave-breaking energy dissipation

NASA Astrophysics Data System (ADS)

Seiffert, Betsy R.; Ducrozet, Guillaume

2018-01-01

We examine the implementation of a wave-breaking mechanism into a nonlinear potential flow solver. The success of the mechanism will be studied by implementing it into the numerical model HOS-NWT, which is a computationally efficient, open source code that solves for the free surface in a numerical wave tank using the high-order spectral (HOS) method. Once the breaking mechanism is validated, it can be implemented into other nonlinear potential flow models. To solve for wave-breaking, first a wave-breaking onset parameter is identified, and then a method for computing wave-breaking associated energy loss is determined. Wave-breaking onset is calculated using a breaking criteria introduced by Barthelemy et al. (J Fluid Mech https://arxiv.org/pdf/1508.06002.pdf, submitted) and validated with the experiments of Saket et al. (J Fluid Mech 811:642-658, 2017). Wave-breaking energy dissipation is calculated by adding a viscous diffusion term computed using an eddy viscosity parameter introduced by Tian et al. (Phys Fluids 20(6): 066,604, 2008, Phys Fluids 24(3), 2012), which is estimated based on the pre-breaking wave geometry. A set of two-dimensional experiments is conducted to validate the implemented wave breaking mechanism at a large scale. Breaking waves are generated by using traditional methods of evolution of focused waves and modulational instability, as well as irregular breaking waves with a range of primary frequencies, providing a wide range of breaking conditions to validate the solver. Furthermore, adjustments are made to the method of application and coefficient of the viscous diffusion term with negligible difference, supporting the robustness of the eddy viscosity parameter. The model is able to accurately predict surface elevation and corresponding frequency/amplitude spectrum, as well as energy dissipation when compared with the experimental measurements. This suggests the model is capable of calculating wave-breaking onset and energy dissipation successfully for a wide range of breaking conditions. The model is also able to successfully calculate the transfer of energy between frequencies due to wave focusing and wave breaking. This study is limited to unidirectional waves but provides a valuable basis for future application of the wave-breaking model to a multidirectional wave field. By including parameters for removing energy due to wave-breaking into a nonlinear potential flow solver, the risk of developing numerical instabilities due to an overturning wave is decreased, thereby increasing the application range of the model, including calculating more extreme sea states. A computationally efficient and accurate model for the generation of a nonlinear random wave field is useful for predicting the dynamic response of offshore vessels and marine renewable energy devices, predicting loads on marine structures, and in the study of open ocean wave generation and propagation in a realistic environment.

Relationship between Age and the Ability to Break Scored Tablets

PubMed Central

Notenboom, Kim; Vromans, Herman; Schipper, Maarten; Leufkens, Hubert G. M.; Bouvy, Marcel L.

2016-01-01

Background: Practical problems with the use of medicines, such as difficulties with breaking tablets, are an often overlooked cause for non-adherence. Tablets frequently break in uneven parts and loss of product can occur due to crumbling and powdering. Health characteristics, such as the presence of peripheral neuropathy, decreased grip strength and manual dexterity, can affect a patient's ability to break tablets. As these impairments are associated with aging and age-related diseases, such as Parkinson's disease and arthritis, difficulties with breaking tablets could be more prevalent among older adults. The objective of this study was to investigate the relationship between age and the ability to break scored tablets. Methods: A comparative study design was chosen. Thirty-six older adults and 36 young adults were systematically observed with breaking scored tablets. Twelve different tablets were included. All participants were asked to break each tablet by three techniques: in between the fingers with the use of nails, in between the fingers without the use of nails and pushing the tablet downward with one finger on a solid surface. It was established whether a tablet was broken or not, and if broken, whether the tablet was broken accurately or not. Results: The older adults experienced more difficulties to break tablets compared to the young adults. On average, the older persons broke 38.1% of the tablets, of which 71.0% was broken accurately. The young adults broke 78.2% of the tablets, of which 77.4% was broken accurately. Further analysis by mixed effects logistic regression revealed that age was associated with the ability to break tablets, but not with the accuracy of breaking. Conclusions: Breaking scored tablets by hand is less successful in an elderly population compared to a group of young adults. Health care providers should be aware that tablet breaking is not appropriate for all patients and for all drugs. In case tablet breaking is unavoidable, a patient's ability to break tablets should be assessed by health care providers and instructions on the appropriate method of breaking should be provided. PMID:27507946

An analytical model for pressure of volume fractured tight oil reservoir with horizontal well

NASA Astrophysics Data System (ADS)

Feng, Qihong; Dou, Kaiwen; Zhang, Xianmin; Xing, Xiangdong; Xia, Tian

2017-05-01

The property of tight oil reservoir is worse than common reservoir that we usually seen before, the porosity and permeability is low, the diffusion is very complex. Therefore, the ordinary depletion method is useless here. The volume fracture breaks through the conventional EOR mechanism, which set the target by amplifying the contact area of fracture and reservoir so as to improving the production of every single well. In order to forecast the production effectively, we use the traditional dual-porosity model, build an analytical model for production of volume fractured tight oil reservoir with horizontal well, and get the analytical solution in Laplace domain. Then we construct the log-log plot of dimensionless pressure and time by stiffest conversion. After that, we discuss the influential factors of pressure. Several factors like cross flow, skin factors and threshold pressure gradient was analyzed in the article. This model provides a useful method for tight oil production forecast and it has certain guiding significance for the production capacity prediction and dynamic analysis.

Project Columbiad: Mission to the Moon. Book 2, volume 3: Stage configuration designs; volume 4: Program plan

NASA Technical Reports Server (NTRS)

1992-01-01

The Earth Orbital Rendezvous (EOR) configuration for the piloted mission is composed of three propulsive elements in addition to the Crew Module (CM): Primary Trans-Lunar Injection (PTLI), Lunar Braking Module (LBM), and Earth Return Module (ERM). The precursor mission is also composed of three propulsive elements in addition to its surface payloads: PTLI, LBM and the Payload Landing Module (PLM). Refer to Volume 1, Section 5.1 and 5.2 for a break-up of the different stages into the four launches. A quick summary is as follows: PTLI is on Launch 1 and 3 while the LBM, PLM, and surface payloads are on Launch 2 and another LBM, ERM, and CM on Launch 4. The precursor mission is designed to be as modular as possible with the piloted mission for developmental cost considerations. The following topics are discussed: launch vehicle description; primary trans-lunar injection stage; lunar braking module; earth return module; crew module; payload landing module; and surface payload description.

The application of symmetry and centricity to polychordal wedge harmony in "Motherchord"

NASA Astrophysics Data System (ADS)

Cathey, Tully J.

This dissertation is in two volumes. Volume I is an analytical paper in two parts. Part I presents a polychordal harmonic system called the "The Desire Matrix Harmonic System," that was used to compose a work for large orchestra called "Motherchord" (Volume II). The polychords are comprised of two triadic units and of major triads only, built on two pairs of intersecting chromatic scales. The system embraces pitch-centric characteristics as well as symmetry. Scales, or tone sets, are derived from the polychords and used for melodic and contrapuntal purposes. Compositional procedures are developed, and a matrix of polychordal wedges is assembled that serves as a further compositional device. Part II of the paper is an analysis of the formal structure of "Motherchord." "Motherchord" is a one-movement composition of approximately seventeen minutes and forty seconds duration. It is divided into seven parts, but proceeds from beginning to end without a break in sound. The title of the work derives from the central tonic polychord.

"big" Divisor D3/D7 Swiss-Cheese Phenomenology

NASA Astrophysics Data System (ADS)

Misra, Aalok

We review progress made over the past couple of years in the field of Swiss-Cheese Phenomenology involving a mobile spacetime filling D3-brane and stack(s) of fluxed D7-branes wrapping the "big" (as opposed to the "small") divisor in (the orientifold of (a) Swiss-Cheese Calabi-Yau. The topics reviewed include reconciliation of large volume cosmology and phenomenology, evaluation of soft supersymmetry breaking parameters, one-loop RG-flow equations' solutions for scalar masses, obtaining fermionic (possibly first two generations' quarks/leptons) mass scales in the {O}(MeV--GeV)-regime as well as (first two generations') neutrino masses (and their one-loop RG flow) of around an eV. The heavy sparticles and the light fermions indicate the possibility of "split SUSY" large volume scenario.

A normative price for energy from an electricity generation system: An Owner-dependent Methodology for Energy Generation (system) Assessment (OMEGA). Volume 2: Derivation of system energy price equations

NASA Technical Reports Server (NTRS)

Chamberlain, R. G.; Mcmaster, K. M.

1981-01-01

The methodology presented is a derivation of the utility owned solar electric systems model. The net present value of the system is determined by consideration of all financial benefits and costs including a specified return on investment. Life cycle costs, life cycle revenues, and residual system values are obtained. Break-even values of system parameters are estimated by setting the net present value to zero.

Triangle Geometry Processing for Surface Modeling and Cartesian Grid Generation

NASA Technical Reports Server (NTRS)

Aftosmis, Michael J. (Inventor); Melton, John E. (Inventor); Berger, Marsha J. (Inventor)

2002-01-01

Cartesian mesh generation is accomplished for component based geometries, by intersecting components subject to mesh generation to extract wetted surfaces with a geometry engine using adaptive precision arithmetic in a system which automatically breaks ties with respect to geometric degeneracies. During volume mesh generation, intersected surface triangulations are received to enable mesh generation with cell division of an initially coarse grid. The hexagonal cells are resolved, preserving the ability to directionally divide cells which are locally well aligned.

ONR (Office of Naval Research) Far East Scientific Bulletin. Volume 9, Number 2, April - June 1984,

DTIC Science & Technology

1984-06-01

minutes. The DH unit is also used for aluminum killing, removal of nonmetallic inclusions (mainly oxides ), calcium treatment for sulfide inclusion...life sciences. His scientific interests include environmental physiology and a more recent interest in membrane phenomena. Dr. lampietro is a member...and 35 kV and is applied to a 5 mm vacuum spark gap but the gap does not break down -. - until a laser pulse is focused on the sharp anode . Enough of

Triangle geometry processing for surface modeling and cartesian grid generation

DOEpatents

Aftosmis, Michael J [San Mateo, CA; Melton, John E [Hollister, CA; Berger, Marsha J [New York, NY

2002-09-03

Cartesian mesh generation is accomplished for component based geometries, by intersecting components subject to mesh generation to extract wetted surfaces with a geometry engine using adaptive precision arithmetic in a system which automatically breaks ties with respect to geometric degeneracies. During volume mesh generation, intersected surface triangulations are received to enable mesh generation with cell division of an initially coarse grid. The hexagonal cells are resolved, preserving the ability to directionally divide cells which are locally well aligned.

A Marine Aerosol Reference Tank system as a breaking wave analogue

NASA Astrophysics Data System (ADS)

Stokes, M. D.; Deane, G. B.; Prather, K.; Bertram, T. H.; Ruppel, M. J.; Ryder, O. S.; Brady, J. M.; Zhao, D.

2012-12-01

In order to better understand the processes governing the production of marine aerosols a repeatable, controlled method for their generation is required. The Marine Aerosol Reference Tank (MART) has been designed to closely approximate oceanic conditions by producing an evolving bubble plume and surface foam patch. The tank utilizes an intermittently plunging sheet of water and large volume tank reservoir to simulate turbulence, plume and foam formation, and is monitored volumetrically and acoustically to ensure the repeatability of conditions.

The Coast Artillery Journal. Volume 75, Number 5, September-October 1932

DTIC Science & Technology

1932-10-01

Chinese attitude toward Japan just before the out- break of the armed conflict in Manchuria and the attitude which the League of Nations has adopted in its...interference with the Manchurian dispute. Chinese Attitude Toward Japan. Japan’s acquired rights were violated everywhere in China. ,Even in the text...from the 1st to 7th grade inclusive. Children of the post enrolled in higher grades attend schools in Phoebus or Hampton. A Kindergarten and nursery

Marine Structural Steel Toughness Data Bank. Volume 3

DTIC Science & Technology

1991-08-28

Headings: Break? Did specimen fracture completely? CODIc Critical COD CODi Initial COD CVN Energy Charpy V Energy Crack lgth Crack Length Curve Curve...BS5762 -Standard Year Test Temp CODIc degC mm -30 0.57 -30 0.68 -30 . 1.26 not rporw(continued) Main Stutua To n ssDta:an Material BS4360 Gr50D Page...Initial JI. . . .. ._I. . . Maximum 1, ]max * Tearing Modulus ......... Standard Method ~P S5762 -Standard Year_______________ Test Tcmp CODIc degC mm

A study of the break-up characteristics of Chena River Basin using ERTS imagery

NASA Technical Reports Server (NTRS)

Carlson, R. F. (Principal Investigator); Kane, D. L.; Wendler, G.

1973-01-01

The author has identified the following significant results. The Chena River Basin was selected because of the availability of ground truth data for comparison. Very good agreement for snow distribution and rates of ablation was found between the ERTS-1 imagery, the snowmelt model, and field measurements. Monitoring snowmelt rates for relatively small basins appears to be practical. The main limitation of the ERTS-1 imagery is the interval of coverage. More frequent overflights providing coverage are needed for the study of transient hydrologic events. ERTS-1 data is most useful when used in conjunction with snowmelt prediction models and existing snow course data. These results should prove very useful in preliminary assessment of hydrologic conditions in ungaged watersheds and will provide a tool for month-to-month volume forecasting.

DNA Strand Breaks in Mitotic Germ Cells of Caenorhabditis elegans Evaluated by Comet Assay

PubMed Central

Park, Sojin; Choi, Seoyun; Ahn, Byungchan

2016-01-01

DNA damage responses are important for the maintenance of genome stability and the survival of organisms. Such responses are activated in the presence of DNA damage and lead to cell cycle arrest, apoptosis, and DNA repair. In Caenorhabditis elegans, double-strand breaks induced by DNA damaging agents have been detected indirectly by antibodies against DSB recognizing proteins. In this study we used a comet assay to detect DNA strand breaks and to measure the elimination of DNA strand breaks in mitotic germline nuclei of C. elegans. We found that C. elegans brc-1 mutants were more sensitive to ionizing radiation and camptothecin than the N2 wild-type strain and repaired DNA strand breaks less efficiently than N2. This study is the first demonstration of direct measurement of DNA strand breaks in mitotic germline nuclei of C. elegans. This newly developed assay can be applied to detect DNA strand breaks in different C. elegans mutants that are sensitive to DNA damaging agents. PMID:26903030

A Controlled Study on the Correlation between Tear Film Volume and Tear Film Stability in Diabetic Patients.

PubMed

Eissa, Iman M; Khalil, Noha M; El-Gendy, Heba A

2016-01-01

Purpose. To assess the tear film quantity and correlate it with the quality and stability of the tear film in diabetics and compare them to age matched controls. Introduction. Diabetes affects tear film parameters in multiple ways. Poor metabolic control and neuropathy are postulated factors. To further understand how diabetes affects tear film parameters this study was conducted. Subjects and Methods. Tear meniscus height was measured by anterior segment OCT, along with tear thinning time, a subtype of noninvasive tear break-up time, and blinking rate per minute which were all recorded for 22 diabetic patients. Correlations between these tear film parameters were studied and then compared to 16 age matched controls. Results. A statistically significant difference was found in blinking rate between the diabetic and the control group (P = 0.002), with higher blinking rate among diabetics. All tear film parameters were negatively correlated with duration of diabetes. A positive correlation was found between tear film volume and stability. Conclusion. Diabetes affects the tear film in various ways. Diabetics should be examined for dry eye signs even in absence of symptoms which may be masked by associated neuropathy. Duration of diabetes has an impact on tear film status.

Simulation of breaking waves using the high-order spectral method with laboratory experiments: Wave-breaking onset

NASA Astrophysics Data System (ADS)

Seiffert, Betsy R.; Ducrozet, Guillaume; Bonnefoy, Félicien

2017-11-01

This study investigates a wave-breaking onset criteria to be implemented in the non-linear potential flow solver HOS-NWT. The model is a computationally efficient, open source code, which solves for the free surface in a numerical wave tank using the High-Order Spectral (HOS) method. The goal of this study is to determine the best method to identify the onset of random single and multiple breaking waves over a large domain at the exact time they occur. To identify breaking waves, a breaking onset criteria based on the ratio of local energy flux velocity to the local crest velocity, introduced by Barthelemy et al. (2017) is selected. The breaking parameter is uniquely applied in the numerical model in that calculations of the breaking onset criteria ratio are not made only at the location of the wave crest, but at every point in the domain and at every time step. This allows the model to calculate the onset of a breaking wave the moment it happens, and without knowing anything about the wave a priori. The application of the breaking criteria at every point in the domain and at every time step requires the phase velocity to be calculated instantaneously everywhere in the domain and at every time step. This is achieved by calculating the instantaneous phase velocity using the Hilbert transform and dispersion relation. A comparison between more traditional crest-tracking techniques shows the calculation of phase velocity using Hilbert transform at the location of the breaking wave crest provides a good approximation of crest velocity. The ability of the selected wave breaking criteria to predict single and multiple breaking events in two dimensions is validated by a series of large-scale experiments. Breaking waves are generated by energy focusing and modulational instability methods, with a wide range of primary frequencies. Steep irregular waves which lead to breaking waves, and irregular waves with an energy focusing wave superimposed are also generated. This set of waves provides a wide range of breaking-wave strengths, types and scales for validation of the model. A comparison of calculations made using HOS-NWT with experimental measurements show that the model is successful at predicting the occurrence of wave breaking, as well as accurately calculating breaking onset time and location. Although the current study is limited to a unidirectional wave field, the success of the wave-breaking model presented provides the basis for application of the model in a multidirectional wave field. By including wave breaking onset with the addition of an appropriate energy dissipation model into HOS-NWT, we can increase the application range of the model, as well as decrease the occurrence of numerical instabilities that are associated with breaking waves in a potential flow solver. An accurate description of the wave field is useful for predicting the dynamic response of offshore vessels and marine renewable energy devices, predicting loads on marine structures and the general physics of ocean waves, for example.

Low-lying baryon spectrum with two dynamical twisted mass fermions

NASA Astrophysics Data System (ADS)

Alexandrou, C.; Baron, R.; Carbonell, J.; Drach, V.; Guichon, P.; Jansen, K.; Korzec, T.; Pène, O.

2009-12-01

The masses of the low-lying baryons are evaluated using two degenerate flavors of twisted mass sea quarks corresponding to pseudoscalar masses in the range of about 270-500 MeV. The strange valence quark mass is tuned to reproduce the mass of the kaon in the physical limit. The tree-level Symanzik improved gauge action is employed. We use lattices of spatial size 2.1 and 2.7 fm at two values of the lattice spacing with r0/a=5.22(2) and r0/a=6.61(3). We check for both finite volume and cutoff effects on the baryon masses. We performed a detailed study of the chiral extrapolation of the octet and decuplet masses using SU(2) χPT. The lattice spacings determined using the nucleon mass at the physical point are consistent with the values extracted using the pion decay constant. We examine the issue of isospin symmetry breaking for the octet and decuplet baryons and its dependence on the lattice spacing. We show that in the continuum limit isospin breaking is consistent with zero, as expected. The baryon masses that we find after taking the continuum limit and extrapolating to the physical limit are in good agreement with experiment.

A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

NASA Astrophysics Data System (ADS)

Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

2015-12-01

In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

Rock breaking methods to replace blasting

NASA Astrophysics Data System (ADS)

Zhou, Huisheng; Xie, Xinghua; Feng, Yuqing

2018-03-01

The method of breaking rock by blasting has a high efficiency and the cost is relatively low, but the associated vibration, flyrock, production of toxic gases since the 1970’s, the Western developed countries began to study the safety of breaking rock. This paper introduces different methods and their progress to safely break rock. Ideally, safe rock breaking would have little vibration, no fly stone, and no toxic gases, which can be widely used in municipal engineering, road excavation, high-risk mining, quarrying and complex environment.

Serving a Higher Power: The Influence of Alternative Break Programs on Students' Religiousness

ERIC Educational Resources Information Center

Niehaus, Elizabeth; Rivera, Mark

2016-01-01

The purpose of this study was to explore the relationship between students' religiousness and participation in alternative breaks (ABs) using both survey and interview data from the National Survey of Alternative Breaks. Findings from this mixed methods study demonstrate the potential for ABs to facilitate religiousness and help students connect…

A decision-making tool to determine economic feasibility and break-even prices for artisan cheese operations.

PubMed

Durham, Catherine A; Bouma, Andrea; Meunier-Goddik, Lisbeth

2015-12-01

Artisan cheese makers lack access to valid economic data to help them evaluate business opportunities and make important business decisions such as determining cheese pricing structure. The objective of this study was to utilize an economic model to evaluate the net present value (NPV), internal rate of return, and payback period for artisan cheese production at different annual production volumes. The model was also used to determine the minimum retail price necessary to ensure positive NPV for 5 different cheese types produced at 4 different production volumes. Milk type, cheese yield, and aging time all affected variable costs. However, aged cheeses required additional investment for aging space (which needs to be larger for longer aging times), as did lower yield cheeses (by requiring larger-volume equipment for pasteurization and milk handling). As the volume of milk required increased, switching from vat pasteurization to high-temperature, short-time pasteurization was necessary for low-yield cheeses before being required for high-yield cheeses, which causes an additional increase in investment costs. Because of these differences, high-moisture, fresh cow milk cheeses can be sold for about half the price of hard, aged goat milk cheeses at the largest production volume or for about two-thirds the price at the lowest production volume examined. For example, for the given model assumptions, at an annual production of 13,608kg of cheese (30,000 lb), a fresh cow milk mozzarella should be sold at a minimum retail price of $27.29/kg ($12.38/lb), whereas a goat milk Gouda needs a minimum retail price of $49.54/kg ($22.47/lb). Artisan cheese makers should carefully evaluate annual production volumes. Although larger production volumes decrease average fixed cost and improve production efficiency, production can reach volumes where it becomes necessary to sell through distributors. Because distributors might pay as little as 35% of retail price, the retail price needs to be higher to compensate. An artisan cheese company that has not achieved the recognition needed to achieve a premium price may not find distribution through distributors profitable. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

MIST final report

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

Gloudemans, J.R.

1991-08-01

The multiloop integral system test (MIST) was part of a multiphase program started in 1983 to address small-break loss-of-coolant accidents (SBLOCAs) specific to Babcock Wilcox-designed plants. MIST was sponsored by the US Nuclear Regulatory Commission, the Babcock Wilcox Owners Group, the Electric Power Research Institute, and Babcock Wilcox. The unique features of the Babcock Wilcox design, specifically the hot leg U-bends and steam generators, prevented the use of existing integral system data or existing integral system facilities to addresss the thermal-hydraulic SBLOCA questions. MIST was specifically designed and constructed for this program, and an existing facility -- the once-through integralmore » system (OTIS) -- was also used. Data from MIST and OTIS are used to benchmark the adequacy of system codes, such as RELAP5 and TRAC, for predicting abnormal plant transients. The MIST program is reported in eleven volumes; Volumes 2 through 8 pertain to groups of Phase 3 tests by type, Volume 9 presents inter-group comparisons. Volume 10 provides comparisons between the RELAP5 MOD2 calculations and MIST observations, and Volume 11 (with addendum) presents the later, Phase 4 tests. This is Volume 1 of the MIST final report, a summary of the entire MIST program. Major topics include: test advisory grop (TAG) issues; facility scaling and design; test matrix; observations; comparisons of RELAP5 calculations to MIST observations; and MIST versus the TAG issues. 11 refs., 29 figs., 9 tabs.« less

Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

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

Qin Xujun; Department of Toxicology, Fourth Military Medical University, Xi'an, Shaanxi, 710032; Hudson, Laurie G.

2008-10-01

Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/ormore » UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite ({<=} 2 {mu}M) alone did not induce significant DNA strand breaks, but greatly enhanced the DNA strand breaks induced by UVR. Further studies showed that 2 {mu}M arsenite effectively inhibited PARP-1 activity. Zinc supplementation of arsenite-treated cells restored PARP-1 activity and significantly diminished the exacerbating effect of arsenite on UVR-induced DNA strand breaks. Importantly, neither arsenite treatment, nor zinc supplementation changed UVR-triggered reactive oxygen species (ROS) formation, suggesting that their effects upon UVR-induced DNA strand breaks are not through a direct free radical mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic.« less

The plant cytoskeleton controls regulatory volume increase.

PubMed

Liu, Qiong; Qiao, Fei; Ismail, Ahmed; Chang, Xiaoli; Nick, Peter

2013-09-01

The ability to adjust cell volume is required for the adaptation to osmotic stress. Plant protoplasts can swell within seconds in response to hypoosmotic shock suggesting that membrane material is released from internal stores. Since the stability of plant membranes depends on submembraneous actin, we asked, whether this regulatory volume control depends on the cytoskeleton. As system we used two cell lines from grapevine which differ in their osmotic tolerance and observed that the cytoskeleton responded differently in these two cell lines. To quantify the ability for regulatory volume control, we used hydraulic conductivity (Lp) as readout and demonstrated a role of the cytoskeleton in protoplast swelling. Chelation of calcium, inhibition of calcium channels, or manipulation of membrane fluidity, did not significantly alter Lp, whereas direct manipulation of the cytoskeleton via specific chemical reagents, or indirectly, through the bacterial elicitor Harpin or activation of phospholipase D, was effective. By optochemical engineering of actin using a caged form of the phytohormone auxin we can break the symmetry of actin organisation resulting in a localised deformation of cell shape indicative of a locally increased Lp. We interpret our findings in terms of a model, where the submembraneous cytoskeleton controls the release of intracellular membrane stores during regulatory volume change. Copyright © 2013 Elsevier B.V. All rights reserved.

Low energy supergravity: R-parity breaking and the top quark mass

NASA Astrophysics Data System (ADS)

Carena, Marcela S.; Wagner, Carlos E. M.

1987-03-01

We study the process of spontaneous R-parity breaking in minimal low energy supergravity models. We show that it is very hard to obtain models with heavy top quarks if one wants to preserve the radiative breaking of SU(2)L⊗U(1)Y without breaking R-parity. Fellow of Consejo National de Investigaciones Cientificas y Tecnicas.

Attributing Changing Rates of Temperature Record Breaking to Anthropogenic Influences

NASA Astrophysics Data System (ADS)

King, Andrew D.

2017-11-01

Record-breaking temperatures attract attention from the media, so understanding how and why the rate of record breaking is changing may be useful in communicating the effects of climate change. A simple methodology designed for estimating the anthropogenic influence on rates of record breaking in a given time series is proposed here. The frequency of hot and cold record-breaking temperature occurrences is shown to be changing due to the anthropogenic influence on the climate. Using ensembles of model simulations with and without human-induced forcings, it is demonstrated that the effect of climate change on global record-breaking temperatures can be detected as far back as the 1930s. On local scales, a climate change signal is detected more recently at most locations. The anthropogenic influence on the increased occurrence of hot record-breaking temperatures is clearer than it is for the decreased occurrence of cold records. The approach proposed here could be applied in rapid attribution studies of record extremes to quantify the influence of climate change on the rate of record breaking in addition to the climate anomaly being studied. This application is demonstrated for the global temperature record of 2016 and the Central England temperature record in 2014.

Experimental evaluation of rigor mortis IX. The influence of the breaking (mechanical solution) on the development of rigor mortis.

PubMed

Krompecher, Thomas; Gilles, André; Brandt-Casadevall, Conception; Mangin, Patrice

2008-04-07

Objective measurements were carried out to study the possible re-establishment of rigor mortis on rats after "breaking" (mechanical solution). Our experiments showed that: *Cadaveric rigidity can re-establish after breaking. *A significant rigidity can reappear if the breaking occurs before the process is complete. *Rigidity will be considerably weaker after the breaking. *The time course of the intensity does not change in comparison to the controls: --the re-establishment begins immediately after the breaking; --maximal values are reached at the same time as in the controls; --the course of the resolution is the same as in the controls.

Deletions at short direct repeats and base substitutions are characteristic mutations for bleomycin-induced double- and single-strand breaks, respectively, in a human shuttle vector system

NASA Technical Reports Server (NTRS)

Dar, M. E.; Jorgensen, T. J.

1995-01-01

Using the radiomimetic drug, bleomycin, we have determined the mutagenic potential of DNA strand breaks in the shuttle vector pZ189 in human fibroblasts. The bleomycin treatment conditions used produce strand breaks with 3'-phosphoglycolate termini as > 95% of the detectable dose-dependent lesions. Breaks with this end group represent 50% of the strand break damage produced by ionizing radiation. We report that such strand breaks are mutagenic lesions. The type of mutation produced is largely determined by the type of strand break on the plasmid (i.e. single versus double). Mutagenesis studies with purified DNA forms showed that nicked plasmids (i.e. those containing single-strand breaks) predominantly produce base substitutions, the majority of which are multiples, which presumably originate from error-prone polymerase activity at strand break sites. In contrast, repair of linear plasmids (i.e. those containing double-strand breaks) mainly results in deletions at short direct repeat sequences, indicating the involvement of illegitimate recombination. The data characterize the nature of mutations produced by single- and double-strand breaks in human cells, and suggests that deletions at direct repeats may be a 'signature' mutation for the processing of DNA double-strand breaks.

Experimental study on the bed shear stress under breaking waves

NASA Astrophysics Data System (ADS)

Hao, Si-yu; Xia, Yun-feng; Xu, Hua

2017-06-01

The object of present study is to investigate the bed shear stress on a slope under regular breaking waves by a novel instrument named Micro-Electro-Mechanical System (MEMS) flexible hot-film shear stress sensor. The sensors were calibrated before application, and then a wave flume experiment was conducted to study the bed shear stress for the case of regular waves spilling and plunging on a 1:15 smooth PVC slope. The experiment shows that the sensor is feasible for the measurement of the bed shear stress under breaking waves. For regular incident waves, the bed shear stress is mainly periodic in both outside and inside the breaking point. The fluctuations of the bed shear stress increase significantly after waves breaking due to the turbulence and vortexes generated by breaking waves. For plunging breaker, the extreme value of the mean maximum bed shear stress appears after the plunging point, and the more violent the wave breaks, the more dramatic increase of the maximum bed shear stress will occur. For spilling breaker, the increase of the maximum bed shear stress along the slope is gradual compared with the plunging breaker. At last, an empirical equation about the relationship between the maximum bed shear stress and the surf similarity parameter is given, which can be used to estimate the maximum bed shear stress under breaking waves in practice.

Risk factors for retinal breaks in patients with symptom of floaters.

PubMed

Singalavanija, Apichart; Amornrattanapan, Chutiwan; Nitiruangjarus, Kanjanee; Tongsai, Sasima

2010-06-01

To identify the risk factors of retinal breaks in patients with the symptom of floaters, and to determine the association between those risk factors and retinal breaks. A retrospective analytic study of 184 patients (55 males and 129 females) that included 220 eyes was conducted. Patient information such as age, symptoms (multiple floaters, flashing), duration of symptom, refractive error, history of cataract surgery, family history of retinal detachment, and complete eye examination were recorded. The patients were divided into two groups, the first group (control group) had symptoms of floaters and no retinal breaks, the second group (retinal breaks group) had symptoms of floaters with retinal breaks. Chi-square test, and the multiple logistic regression were used for statistical analysis. Two hundred twenty eyes, 175 eyes of the control group and 45 eyes of the retinal breaks group were examined and included in this study. The multiple logistic regression analysis revealed that patients with multiple floaters, and floaters and flashing increased the risk of retinal breaks to 5.8 and 4.3 times, respectively, when compared to patients with single floater or floaters alone. Lattice degeneration increased the risk of retinal breaks to 5.9 times when compared to eyes that did not have lattice degeneration. Multiple floaters, flashing and lattice degeneration are risk factors of retinal breaks in patients with symptoms of floaters. Therefore, it is important for the ophthalmologists to be aware of these risk factors and the patients at risk should have follow-up examinations.

Biomonitoring of genotoxic risk in workers in a rubber factory: comparison of the Comet assay with cytogenetic methods and immunology.

PubMed

Somorovská, M; Szabová, E; Vodicka, P; Tulinská, J; Barancoková, M; Fábry, R; Lísková, A; Riegerová, Z; Petrovská, H; Kubová, J; Rausová, K; Dusinská, M; Collins, A

1999-09-30

Several substances used in rubber processing are known to be genotoxic. Workers in a rubber tyre factory, exposed to a broad spectrum of contaminants such as benzo[a]pyrene, benzo-fluoranthene, naphthalene, acetonaphthene, alkenes and 1,3-butadiene have been regularly examined for several years: chromosomal aberrations in lymphocytes, mutagenicity of urine (by use of the Ames test) and various parameters of blood and urine were assessed. An elevated level of mercapturic acid derivatives was found in the urine of employees, which is indicative of environmental exposure to toxicants with alkylating activity. We have now extended this study by examining genotoxicity with the modified Comet assay in parallel with chromosomal aberrations and micronucleus formation as well as immunological endpoints. Twenty-nine exposed workers from this factory were compared with 22 non-exposed administrative staff working in the same factory, as well as with 22 laboratory workers. The absolute numbers of peripheral leukocytes were significantly higher in the exposed group than in either of the control groups (p < 0.001). The erythrocyte mean cell volume was significantly higher in exposed workers in comparison with laboratory controls (p < 0.05). Percentages of lymphocytes, polymorphonuclear leukocytes, monocytes and eosinophils were not altered. The proliferative response of T- and B-cells to mitogen treatment when calculated per number of lymphocytes and adjusted for smoking, age and years of exposure did not differ between exposed and control groups. Endogenous strand breaks (including alkali-labile sites) and altered bases (formamidopyrimidine glycosylase- and endonuclease III-sensitive sites) were measured by the Comet assay in lymphocyte DNA. Exposed workers had significantly elevated levels of DNA breaks compared with office workers (p < 0.00001) or with laboratory controls (p < 0.00001). Micronuclei occurred at significantly higher frequencies in the exposed group than in controls (p < 0.00001), though the frequencies were all within the normal range. Significant correlations were seen between individual values of strand breaks, micronuclei and chromatid/chromosome breaks and certain immunological parameters.

Multimodal evidence of regional midcingulate gray matter volume underlying conflict monitoring

PubMed Central

Parvaz, Muhammad A.; Maloney, Thomas; Moeller, Scott J.; Malaker, Pias; Konova, Anna B.; Alia-Klein, Nelly; Goldstein, Rita Z.

2014-01-01

Functional neuroimaging studies have long implicated the mid-cingulate cortex (MCC) in conflict monitoring, but it is not clear whether its structural integrity (i.e., the gray matter volume) influences its conflict monitoring function. In this multimodal study, we used T1-weighted MRI scans as well as event-related potentials (ERPs) to test whether the MCC gray matter volume is associated with the electrocortical marker (i.e., No-go N200 ERP component) of conflict monitoring in healthy individuals. The specificity of such a relationship in health was determined in two ways: by (A) acquiring the same data from individuals with cocaine use disorder (CUD), known to have deficits in executive function including behavioral monitoring; and (B) acquiring the P300 ERP component that is linked with attention allocation and not specifically with conflict monitoring. Twenty-five (39.1 ± 8.4 years; 8 females) healthy individuals and 25 (42.7 ± 5.9 years; 6 females) individuals with CUD underwent a rewarded Go/No-go task during which the ERP data was collected, and they also underwent a structural MRI scan. The whole brain regression analysis showed a significant correlation between MCC structural integrity and the well-known ERP measure of conflict monitoring (N200, but not the P300) in healthy individuals, which was absent in CUD who were characterized by reduced MCC gray matter volume, N200 abnormalities as well as reduced task accuracy. In individuals with CUD instead, the N200 amplitude was associated with drug addiction symptomatology. These results show that the integrity of MCC volume is directly associated with the electrocortical correlates of conflict monitoring in healthy individuals, and such an association breaks down in psychopathologies that impact these brain processes. Taken together, this MCC–N200 association may serve as a biomarker of improved behavioral monitoring processes in diseased populations. PMID:24918068

Multimodal evidence of regional midcingulate gray matter volume underlying conflict monitoring.

PubMed

Parvaz, Muhammad A; Maloney, Thomas; Moeller, Scott J; Malaker, Pias; Konova, Anna B; Alia-Klein, Nelly; Goldstein, Rita Z

2014-01-01

Functional neuroimaging studies have long implicated the mid-cingulate cortex (MCC) in conflict monitoring, but it is not clear whether its structural integrity (i.e., the gray matter volume) influences its conflict monitoring function. In this multimodal study, we used T1-weighted MRI scans as well as event-related potentials (ERPs) to test whether the MCC gray matter volume is associated with the electrocortical marker (i.e., No-go N200 ERP component) of conflict monitoring in healthy individuals. The specificity of such a relationship in health was determined in two ways: by (A) acquiring the same data from individuals with cocaine use disorder (CUD), known to have deficits in executive function including behavioral monitoring; and (B) acquiring the P300 ERP component that is linked with attention allocation and not specifically with conflict monitoring. Twenty-five (39.1 ± 8.4 years; 8 females) healthy individuals and 25 (42.7 ± 5.9 years; 6 females) individuals with CUD underwent a rewarded Go/No-go task during which the ERP data was collected, and they also underwent a structural MRI scan. The whole brain regression analysis showed a significant correlation between MCC structural integrity and the well-known ERP measure of conflict monitoring (N200, but not the P300) in healthy individuals, which was absent in CUD who were characterized by reduced MCC gray matter volume, N200 abnormalities as well as reduced task accuracy. In individuals with CUD instead, the N200 amplitude was associated with drug addiction symptomatology. These results show that the integrity of MCC volume is directly associated with the electrocortical correlates of conflict monitoring in healthy individuals, and such an association breaks down in psychopathologies that impact these brain processes. Taken together, this MCC-N200 association may serve as a biomarker of improved behavioral monitoring processes in diseased populations.

Esophageal mucosal breaks in gastroesophageal reflux disease partially responsive to proton pump inhibitor therapy.

PubMed

Shaheen, Nicholas J; Denison, Hans; Björck, Karin; Silberg, Debra G

2013-04-01

Approximately 20-30% of patients with gastroesophageal reflux disease (GERD) do not experience complete symptom resolution during proton pump inhibitor (PPI) therapy. The aim of this study was to determine the prevalence of esophageal mucosal breaks among patients who have a partial response to PPI therapy. This was an analysis of data from a phase 2b clinical trial carried out to assess the efficacy and safety of a reflux inhibitor, lesogaberan (AZD3355), as an add-on to PPI therapy in this patient population (clinicaltrials.gov reference: NCT01005251). A total of 661 patients with persistent GERD symptoms who had received a minimum of 4 weeks of PPI therapy were included in the study. The prevalence of esophageal mucosal breaks was assessed according to (i) the most recent endoscopy results from within the previous 24 months, if available ("historical" endoscopies), and (ii) the results of endoscopies performed at study baseline ("baseline" endoscopies). Baseline endoscopies were not carried out in patients who had a historical endoscopy showing an absence of esophageal mucosal breaks. Historical endoscopy results were available for 244 patients, of whom 48 (19.7%) had esophageal mucosal breaks. Baseline endoscopies were carried out in 465 patients, of whom 146 (31.4%) had esophageal mucosal breaks. Sensitivity analyses showed a prevalence of esophageal mucosal breaks of 20-30%. In both the historical and baseline endoscopies, most esophageal mucosal breaks were Los Angeles grades A or B. In patients with GERD symptoms partially responsive to PPI therapy, mild-to-moderate severity esophageal mucosal breaks are common (prevalence 20-30%), and may contribute to symptom etiology.

A catastrophic flood caused by drainage of a caldera lake at Aniakchak Volcano, Alaska, and implications for volcanic hazards assessment

USGS Publications Warehouse

Waythomas, C.F.; Walder, J.S.; McGimsey, R.G.; Neal, C.A.

1996-01-01

Aniakchak caldera, located on the Alaska Peninsula of southwest Alaska, formerly contained a large lake (estimated volume 3.7 ?? 109 m3) that rapidly drained as a result of failure of the caldera rim sometime after ca. 3400 yr B.P. The peak discharge of the resulting flood was estimated using three methods: (1) flow-competence equations, (2) step-backwater modeling, and (3) a dam-break model. The results of the dam-break model indicate that the peak discharge at the breach in the caldera rim was at least 7.7 ?? 104 m3 s-1, and the maximum possible discharge was ???1.1 ?? 106 m3 s-1. Flow-competence estimates of discharge, based on the largest boulders transported by the flood, indicate that the peak discharge values, which were a few kilometers downstream of the breach, ranged from 6.4 ?? 105 to 4.8 ?? 106 m3 s-1. Similar but less variable results were obtained by step-backwater modeling. Finally, discharge estimates based on regression equations relating peak discharge to the volume and depth of the impounded water, although limited by constraining assumptions, provide results within the range of values determined by the other methods. The discovery and documentation of a flood, caused by the failure of the caldera rim at Aniakchak caldera, underscore the significance and associated hydrologic hazards of potential large floods at other lake-filled calderas.

Quantitative analysis of the thermal requirements for stepwise physical dormancy-break in seeds of the winter annual Geranium carolinianum (Geraniaceae)

PubMed Central

Gama-Arachchige, N. S.; Baskin, J. M.; Geneve, R. L.; Baskin, C. C.

2013-01-01

Background and Aims Physical dormancy (PY)-break in some annual plant species is a two-step process controlled by two different temperature and/or moisture regimes. The thermal time model has been used to quantify PY-break in several species of Fabaceae, but not to describe stepwise PY-break. The primary aims of this study were to quantify the thermal requirement for sensitivity induction by developing a thermal time model and to propose a mechanism for stepwise PY-breaking in the winter annual Geranium carolinianum. Methods Seeds of G. carolinianum were stored under dry conditions at different constant and alternating temperatures to induce sensitivity (step I). Sensitivity induction was analysed based on the thermal time approach using the Gompertz function. The effect of temperature on step II was studied by incubating sensitive seeds at low temperatures. Scanning electron microscopy, penetrometer techniques, and different humidity levels and temperatures were used to explain the mechanism of stepwise PY-break. Key Results The base temperature (Tb) for sensitivity induction was 17·2 °C and constant for all seed fractions of the population. Thermal time for sensitivity induction during step I in the PY-breaking process agreed with the three-parameter Gompertz model. Step II (PY-break) did not agree with the thermal time concept. Q10 values for the rate of sensitivity induction and PY-break were between 2·0 and 3·5 and between 0·02 and 0·1, respectively. The force required to separate the water gap palisade layer from the sub-palisade layer was significantly reduced after sensitivity induction. Conclusions Step I and step II in PY-breaking of G. carolinianum are controlled by chemical and physical processes, respectively. This study indicates the feasibility of applying the developed thermal time model to predict or manipulate sensitivity induction in seeds with two-step PY-breaking processes. The model is the first and most detailed one yet developed for sensitivity induction in PY-break. PMID:23456728

Water level effects on breaking wave setup for Pacific Island fringing reefs

NASA Astrophysics Data System (ADS)

Becker, J. M.; Merrifield, M. A.; Ford, M.

2014-02-01

The effects of water level variations on breaking wave setup over fringing reefs are assessed using field measurements obtained at three study sites in the Republic of the Marshall Islands and the Mariana Islands in the western tropical Pacific Ocean. At each site, reef flat setup varies over the tidal range with weaker setup at high tide and stronger setup at low tide for a given incident wave height. The observed water level dependence is interpreted in the context of radiation stress gradients specified by an idealized point break model generalized for nonnormally incident waves. The tidally varying setup is due in part to depth-limited wave heights on the reef flat, as anticipated from previous reef studies, but also to tidally dependent breaking on the reef face. The tidal dependence of the breaking is interpreted in the context of the point break model in terms of a tidally varying wave height to water depth ratio at breaking. Implications for predictions of wave-driven setup at reef-fringed island shorelines are discussed.

Beyond the Career Break. A Study of Professional and Managerial Women Returning to Work after Having a Child.

ERIC Educational Resources Information Center

Hirsh, Wendy; And Others

A study was conducted of women managers and professionals in Britain who had taken a "career break"--from a few weeks to many years--to have a baby. The study sought to examine the decision to return to work after having a child, and whether the practical management of breaks could be improved; to discover the career patterns of women…

Assessment of DNA double-strand breaks induced by intravascular iodinated contrast media following in vitro irradiation and in vivo, during paediatric cardiac catheterization.

PubMed

Gould, Richard; McFadden, Sonyia L; Horn, Simon; Prise, Kevin M; Doyle, Philip; Hughes, Ciara M

2016-01-01

Paediatric cardiac catheterizations may result in the administration of substantial amounts of iodinated contrast media and ionizing radiation. The aim of this work was to investigate the effect of iodinated contrast media in combination with in vitro and in vivo X-ray radiation on lymphocyte DNA. Six concentrations of iodine (15, 17.5, 30, 35, 45, and 52.5 mg of iodine per mL blood) represented volumes of iodinated contrast media used in the clinical setting. Blood obtained from healthy volunteers was mixed with iodinated contrast media and exposed to radiation doses commonly used in paediatric cardiac catheterizations (0 mGy, 70 mGy, 140 mGy, 250 mGy and 450 mGy). Control samples contained no iodine. For in vivo experimentation, pre and post blood samples were collected from children undergoing cardiac catheterization, receiving iodine concentrations of up to 51 mg of iodine per mL blood and radiation doses of up to 400 mGy. Fluorescence microscopy was performed to assess γH2AX-foci induction, which corresponded to the number of DNA double-strand breaks. The presence of iodine in vitro resulted in significant increases of DNA double-strand breaks beyond that induced by radiation for ≥ 17.5 mg/mL iodine to blood. The in vivo effects of contrast media on children undergoing cardiac catheterization resulted in a 19% increase in DNA double-strand breaks in children receiving an average concentration of 19 mg/mL iodine to blood. A larger investigation is required to provide further information of the potential benefit of lowering the amount of iodinated contrast media received during X-ray radiation investigations. Copyright © 2015 John Wiley & Sons, Ltd.

The time-of-day that breaks occur between consecutive duty periods affects the sleep strategies used by shiftworkers.

PubMed

Roach, Gregory D; Dawson, Drew; Reid, Kathryn J; Darwent, David; Sargent, Charli

The aim of this study was to examine the sleep strategies used in breaks between consecutive shifts. For two weeks, 253 shiftworkers collected data regarding the timing of all shifts and sleeps. The final dataset included 395 between-shift breaks that had a standard duration (i.e. ~16 h). If a break included an entire night, participants had a single sleep on 80-93% of occasions, but if a break occurred predominantly during the daytime, participants had more than one sleep on 41-50% of occasions. These data indicate that the sleep strategy employed is influenced by the time-of-day that a break occurs.

The Relationship between Growth Mindset, Body Breaks, and Perseverance as a Charactertistic of Grit in First-Grade Classrooms

ERIC Educational Resources Information Center

Smith, Heather

2017-01-01

Although studies such as Wadsworth, Robinson, Beckham, and Webster (2011) as well as Goh, Hannon, Webster, Podlog, and Pillow (2014) have focused on the impact of body breaks and cognitive abilities or tasks, this study investigates the connection between body breaks built into classroom routine and growth mindset education on students' perception…

Booster Breaks in the workplace: participants’ perspectives on health-promoting work breaks

PubMed Central

Taylor, Wendell C.; King, Kathryn E.; Shegog, Ross; Paxton, Raheem J.; Evans-Hudnall, Gina L.; Rempel, David M.; Chen, Vincent; Yancey, Antronette K.

2013-01-01

Increasing sedentary work has been associated with greater cardiovascular and metabolic risk, as well as premature mortality. Interrupting the sedentary workday with health-promoting work breaks can counter these negative health effects. To examine the potential sustainability of work-break programs, we assessed the acceptance of these breaks among participants in a Booster Break program. We analyzed qualitative responses from 35 participants across five worksites where one 15-min physical activity break was taken each workday. Two worksites completed a 1-year intervention and three worksites completed a 6-month intervention. Responses to two open-ended questions about the acceptance and feasibility of Booster Breaks were obtained from a survey administered after the intervention. Three themes for benefits and two themes for barriers were identified. The benefit themes were (i) reduced stress and promoted enjoyment, (ii) increased health awareness and facilitated behavior change, and (iii) enhanced workplace social interaction. The barrier themes were the need for (iv) greater variety in Booster Break routines and (v) greater management support. This study provides empirical support for the acceptance and feasibility of Booster Breaks during the workday. Emphasizing the benefits and minimizing the barriers are strategies that can be used to implement Booster Breaks in other workplaces. PMID:23466367

Correlates of children’s time-specific physical activity: A review of the literature

PubMed Central

2012-01-01

Assessment of correlates of physical activity occurring at different times of the day, locations and contexts, is imperative to understanding children’s physical activity behaviour. The purpose of this review was to identify the correlates of children’s physical activity (aged 8–14 years) occurring during the school break time and after-school periods. A review was conducted of the peer-reviewed literature, published between 1990 and January 2011. A total of 22 studies (12 school break time studies, 10 after-school studies) were included in the review. Across the 22 studies, 17 studies were cross-sectional and five studies were interventions. In the school break time studies, 39 potential correlates were identified, of which gender and age were consistently associated with school break time physical activity in two or more studies, and family affluence, access to a gym, access to four or more physical activity programs and the condition of a playing field were all associated with school break time physical activity in only one study. Access to loose and fixed equipment, playground markings, size of and access to play space and the length of school break time were all positively associated with changes in school break time physical activity in intervention studies. Thirty-six potential correlates of after-school physical activity were identified. Gender (with boys more active), younger age, lower body mass index (for females), lower TV viewing/playing video games, and greater access to facilities were associated with higher levels of after-school physical activity in two or more studies. Parent supervision was negatively associated with females’ after-school physical activity in one study. This review has revealed a relatively small number of studies investigating the school break time and after-school periods in the specified age range and only a few correlates have demonstrated a consistent association with physical activity. This highlights the infancy of this area and a need for further investigation into time-specific physical activity behaviour so that interventions designed for these specific periods can target the important correlates. PMID:22546218

The impacts of short break provision on families with a disabled child: an international literature review.

PubMed

Robertson, Janet; Hatton, Chris; Wells, Emma; Collins, Michelle; Langer, Susanne; Welch, Vicki; Emerson, Eric

2011-07-01

There are widespread assumptions about the potential impacts of short breaks on family carers and disabled children. This review aims to evaluate the existing international research evidence concerning the impacts of short breaks on families with a disabled child. Electronic literature searches were conducted using ASSIA, PsycInfo, CINAHL, and Web of Science, and requests for information were sent to selected email lists. Of 60 articles or reports identified for inclusion in the review, the vast majority of studies were cross-sectional, with only eight studies using quasi-experimental pre-post designs or longitudinal designs. Nonetheless, the consistency with which some findings have been reported suggests that short breaks appear to have the potential to positively impact on not only the well-being of carers, but also the children receiving short breaks and their families as a whole. Additional research is warranted in a number of areas. First, research needs to consider the impact of short breaks on fathers. Second, there is a need to consider in more depth how short breaks can impact on the siblings of disabled children. Third, research could consider how best short breaks can be combined with other interventions to maximise the impact for disabled children and their families. Fourth, research needs to look at the longer term impact of short breaks on outcomes for disabled children and their families. What is needed is evidence on what type of short breaks are best for children and families with particular characteristics at particular times during the course of the child's maturation towards adulthood. © 2010 Blackwell Publishing Ltd.

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

Chakraborty, Bipasha; Davies, C. T. H.; de Oliveira, P. G.

We determine the contribution to the anomalous magnetic moment of the muon from themore » $$\\alpha^2_{\\mathrm{QED}}$$ hadronic vacuum polarization diagram using full lattice QCD and including $u/d$ quarks with physical masses for the first time. We use gluon field configurations that include $u$, $d$, $s$ and $c$ quarks in the sea at multiple values of the lattice spacing, multiple $u/d$ masses and multiple volumes that allow us to include an analysis of finite-volume effects. We obtain a result for $$a_{\\mu}^{\\mathrm{HVP,LO}}$$ of $667(6)(12)$, where the first error is from the lattice calculation and the second includes systematic errors from missing QED and isospin-breaking effects and from quark-line disconnected diagrams. Our result implies a discrepancy between the experimental determination of $$a_{\\mu}$$ and the Standard Model of 3$$\\sigma$$.« less

Reflections on Peter Slezak and the 'Sociology of Scientific Knowledge`

NASA Astrophysics Data System (ADS)

Suchting, W. A.

The paper examines central parts of the first of two papers in this journal by Peter Slezak criticising sociology of scientific knowledge and also considers, independently, some of the main philosophical issues raised by the sociologists of science, in particular David Bloor. The general conclusion is that each account alludes to different and crucial aspects of the nature of knowledge without, severally or jointly, being able to theorise them adequately. The appendix contains epistemological theses central to a more adequate theory of scientific knowledge.... our Histories of six Thousand Moons make no Mention of any other, than the two great Empires of Lilliput and Blefuscu. Which mighty Powers have ... been engaged in a most obstinate War for six and thirty Moons past. It began upon the following Occasion. It is allowed on all Hands, that the primitive Way of breaking Eggs before we eat them, was upon the larger End: But ... the Emperor [of Lilliput] ... published an Edict, commanding all his Subjects, upon great Penalties, to break the smaller End of their Eggs. The People so resented this Law, that ... there have been six Rebellions raised on that Account ... These civil Commotions were constantly fomented by the Monarchs of Blefuscu ... It is computed, that eleven Thousand have, at several Times, suffered Death, rather than break Eggs at the smaller End. Many hundred large Volumes have published upon this Controversy ...

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

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

Rezaee, Mohammad, E-mail: Mohammad.Rezaee@USherbrooke.ca; Hunting, Darel J.; Sanche, Léon

2014-07-15

Purpose: The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods: Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by{sup 125}I withinmore » DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results: For a single decay of{sup 125}I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm{sup 3} volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions: Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide.« less

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

PubMed Central

Rezaee, Mohammad; Hunting, Darel J.; Sanche, Léon

2015-01-01

Purpose The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by 125I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results For a single decay of 125I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm3 volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide. PMID:24989405

The autumn effect: timing of physical dormancy break in seeds of two winter annual species of Geraniaceae by a stepwise process

PubMed Central

Gama-Arachchige, N. S.; Baskin, J. M.; Geneve, R. L.; Baskin, C. C.

2012-01-01

Background and Aims The involvement of two steps in the physical dormancy (PY)-breaking process previously has been demonstrated in seeds of Fabaceae and Convolvulaceae. Even though there is a claim for a moisture-controlled stepwise PY-breaking in some species of Geraniaceae, no study has evaluated the role of temperature in the PY-breaking process in this family. The aim of this study was to determine whether a temperature-controlled stepwise PY-breaking process occurs in seeds of the winter annuals Geranium carolinianum and G. dissectum. Methods Seeds of G. carolinianum and G. dissectum were stored under different temperature regimes to test the effect of storage temperature on PY-break. The role of temperature and moisture regimes in regulating PY-break was investigated by treatments simulating natural conditions. Greenhouse (non-heated) experiments on seed germination and burial experiments (outdoors) were carried out to determine the PY-breaking behaviour in the natural habitat. Key Results Irrespective of moisture conditions, sensitivity to the PY-breaking step in seeds of G. carolinianum was induced at temperatures ≥20 °C, and exposure to temperatures ≤20 °C made the sensitive seeds permeable. Sensitivity of seeds increased with time. In G. dissectum, PY-break occurred at temperatures ≥20 °C in a single step under constant wet or dry conditions and in two steps under alternate wet–dry conditions if seeds were initially kept wet. Conclusions Timing of seed germination with the onset of autumn can be explained by PY-breaking processes involving (a) two temperature-dependent steps in G. carolinianum and (b) one or two moisture-dependent step(s) along with the inability to germinate under high temperatures in G. dissectum. Geraniaceae is the third of 18 families with PY in which a two-step PY-breaking process has been demonstrated. PMID:22684684

Rationale and design of ASTEROID 2, a randomized, placebo- and active comparator-controlled study to assess the efficacy and safety of vilaprisan in patients with uterine fibroids.

PubMed

Seitz, Christian; Bumbuliene, Žana; Costa, Ana Rosa; Heikinheimo, Oskari; Heweker, Andrea; Hudeček, Robert; Jacquemyn, Yves; Melis, Gian Benedetto; Parashar, Pooja; Rechberger, Tomasz; Sánchez, Antonio Cano; van Aken, Bart; Zatik, János; Gemzell-Danielsson, Kristina

2017-04-01

Uterine fibroids (UFs) may be treated with progesterone receptor modulators (PRMs), which have been shown to reduce heavy menstrual bleeding and the size of UFs. To date, one PRM (ulipristal acetate) has received regulatory approval for the treatment of UFs; therapy comprises intermittent treatment courses of up to 3months each, followed by a break to allow two menstruations to occur. We report the design of ASTEROID (Assess Safety and efficacy of vilaprisan in patients with uTERine fibrOIDs) 2, a phase 2 study examining the efficacy and safety of a novel PRM, vilaprisan, in women with UFs. In this randomized multi-arm study, vilaprisan (2mg daily) will be administered in different regimens: continuous treatment for 12 or 24weeks, or two 12-week treatment periods separated by a break to allow one menstruation to occur. Efficacy and safety will be compared with that of ulipristal acetate (5mg daily) and placebo. Patients randomized to receive placebo for 12weeks will also be given active treatment for 12weeks. The primary measure of efficacy will be amenorrhoea rate; secondary measures include time to normalized menstrual bleeding and percentage change in UF volume. Endometrial changes will be monitored throughout the study. The placebo- and active comparator-controlled trial ASTEROID 2 is the first study to evaluate systematically the efficacy and safety of different treatment regimens of PRMs in women with UFs. The findings of this study will direct the planning of future clinical trials of vilaprisan. Copyright © 2017 Bayer AG. Published by Elsevier Inc. All rights reserved.

Are we there yet? The state of the evidence base for guidelines on breaking bad news to cancer patients.

PubMed

Paul, C L; Clinton-McHarg, T; Sanson-Fisher, R W; Douglas, H; Webb, G

2009-11-01

The way clinicians break bad news to cancer patients has been retrospectively associated with poor psychosocial outcomes for patients. Education and practice in breaking bad news may be ineffective for improving patients' well-being unless it is informed by a sound evidence base. In the health field, research efforts are expected to advance evidence over time to inform evidence-based practice. Key characteristics of an advancing evidence base are a predominance of new data, and rigorous intervention studies which prospectively demonstrate improved outcomes. This review aimed to examine the progress of the evidence base in breaking bad news to cancer patients. Manual and computer-based searches (Medline and PsycINFO) were performed to identify publications on the topic of breaking bad news to cancer patients published between January 1995 and March 2009. Relevant publications were coded in terms of whether they provided new data, examined psychosocial outcomes for patients or tested intervention strategies and whether intervention studies met criteria for design rigour. Of the 245 relevant publications, 55.5% provided new data and 16.7% were intervention studies. Much of the intervention effort was directed towards improving provider skills rather than patient outcomes (9.8% of studies). Less than 2% of publications were rigorous intervention studies which addressed psychosocial outcomes for patients. Rigorous intervention studies which evaluate strategies for improving psychosocial outcomes in relation to breaking bad news to cancer patients are needed. Current practice and training regarding breaking bad news cannot be regarded as evidence-based until further research is completed.

Mode structure symmetry breaking of energetic particle driven beta-induced Alfvén eigenmode

NASA Astrophysics Data System (ADS)

Lu, Z. X.; Wang, X.; Lauber, Ph.; Zonca, F.

2018-01-01

The mode structure symmetry breaking of energetic particle driven Beta-induced Alfvén Eigenmode (BAE) is studied based on global theory and simulation. The weak coupling formula gives a reasonable estimate of the local eigenvalue compared with global hybrid simulation using XHMGC. The non-perturbative effect of energetic particles on global mode structure symmetry breaking in radial and parallel (along B) directions is demonstrated. With the contribution from energetic particles, two dimensional (radial and poloidal) BAE mode structures with symmetric/asymmetric tails are produced using an analytical model. It is demonstrated that the symmetry breaking in radial and parallel directions is intimately connected. The effects of mode structure symmetry breaking on nonlinear physics, energetic particle transport, and the possible insight for experimental studies are discussed.

Welcome home, Descartes! rethinking the anthropology of the body.

PubMed

Ecks, Stefan

2009-01-01

For many scholars, the Cartesian mind/body split is one of the fundamental mistakes of the Western scientific tradition. Anthropologists who study notions of the body in cultures around the world regularly take Descartes as their point of departure. Many also suggest that breaking free from Descartes is politically liberating: if the mindful body could be rediscovered, society could move away from its materialist, positivist, and commodity-fetishizing ways. Beyond the Body Proper is anthropology's best and most comprehensive anti-Cartesian manifesto to date. This volume brings together some of the finest studies on the cultural and historical diversity of bodies and minds. Yet anthropologists' blanket rejection of the mind/body dualism seems politically self-defeating. If anthropologists want to criticize racism, gender hierarchies, or discrimination against disabled people, they need to believe that the mind is independent from the body. In other words, they need to uphold the Cartesian split.

Space Station Mission Planning Study (MPS) development study. Volume 3: Software development plan

NASA Technical Reports Server (NTRS)

Klus, W. L.

1987-01-01

A software development plan is presented for the definition, design, and implementation of the Space Station (SS) Payload Mission Planning System (MPS). This plan is an evolving document and must be updated periodically as the SS design and operations concepts as well as the SS MPS concept evolve. The major segments of this plan are as follows: an overview of the SS MPS and a description of its required capabilities including the computer programs identified as configurable items with an explanation of the place and function of each within the system; an overview of the project plan and a detailed description of each development project activity breaking each into lower level tasks where applicable; identification of the resources required and recommendations for the manner in which they should be utilized including recommended schedules and estimated manpower requirements; and a description of the practices, standards, and techniques recommended for the SS MPS Software (SW) development.

Novel regenerative large-volume immobilized enzyme reactor: preparation, characterization and application.

PubMed

Ruan, Guihua; Wei, Meiping; Chen, Zhengyi; Su, Rihui; Du, Fuyou; Zheng, Yanjie

2014-09-15

A novel large-volume immobilized enzyme reactor (IMER) on small column was prepared with organic-inorganic hybrid silica particles and applied for fast (10 min) and oriented digestion of protein. At first, a thin enzyme support layer was formed in the bottom of the small column by polymerization with α-methacrylic acid and dimethacrylate. After that, amino SiO2 particles was prepared by the sol-gel method with tetraethoxysilane and 3-aminopropyltriethoxysilane. Subsequently, the amino SiO2 particles were activated by glutaraldehyde for covalent immobilization of trypsin. Digestive capability of large-volume IMER for proteins was investigated by using bovine serum albumin (BSA), cytochrome c (Cyt-c) as model proteins. Results showed that although the sequence coverage of the BSA (20%) and Cyt-c (19%) was low, the large-volume IMER could produce peptides with stable specific sequence at 101-105, 156-160, 205-209, 212-218, 229-232, 257-263 and 473-451 of the amino sequence of BSA when digesting 1mg/mL BSA. Eight of common peptides were observed during each of the ten runs of large-volume IMER. Besides, the IMER could be easily regenerated by reactivating with GA and cross-linking with trypsin after breaking the -C=N- bond by 0.01 M HCl. The sequence coverage of BSA from regenerated IMER increased to 25% comparing the non-regenerated IMER (17%). 14 common peptides. accounting for 87.5% of first use of IMER, were produced both with IMER and regenerated IMER. When the IMER was applied for ginkgo albumin digestion, the sequence coverage of two main proteins of ginkgo, ginnacin and legumin, was 56% and 55%, respectively. (Reviewer 2) Above all, the fast and selective digestion property of the large-volume IMER indicated that the regenerative IMER could be tentatively used for the production of potential bioactive peptides and the study of oriented protein digestion. Copyright © 2014 Elsevier B.V. All rights reserved.

Numerical Investigation on Sensitivity of Liquid Jet Breakup to Physical Fuel Properties with Experimental Comparison

NASA Astrophysics Data System (ADS)

Kim, Dokyun; Bravo, Luis; Matusik, Katarzyna; Duke, Daniel; Kastengren, Alan; Swantek, Andy; Powell, Christopher; Ham, Frank

2016-11-01

One of the major concerns in modern direct injection engines is the sensitivity of engine performance to fuel characteristics. Recent works have shown that even slight differences in fuel properties can cause significant changes in efficiency and emission of an engine. Since the combustion process is very sensitive to the fuel/air mixture formation resulting from disintegration of liquid jet, the precise assessment of fuel sensitivity on liquid jet atomization process is required first to study the impact of different fuels on the combustion. In the present study, the breaking process of a liquid jet from a diesel injector injecting into a quiescent gas chamber is investigated numerically and experimentally for different liquid fuels (n-dodecane, iso-octane, CAT A2 and C3). The unsplit geometric Volume-of-Fluid method is employed to capture the phase interface in Large-eddy simulations and results are compared against the radiography measurement from Argonne National Lab including jet penetration, liquid mass distribution and volume fraction. The breakup characteristics will be shown for different fuels as well as droplet PDF statistics to demonstrate the influences of the physical properties on the primary atomization of liquid jet. Supported by HPCMP FRONTIER award, US DOD, Office of the Army.

Supramolecular Systems and Chemical Reactions in Single-Molecule Break Junctions.

PubMed

Li, Xiaohui; Hu, Duan; Tan, Zhibing; Bai, Jie; Xiao, Zongyuan; Yang, Yang; Shi, Jia; Hong, Wenjing

2017-04-01

The major challenges of molecular electronics are the understanding and manipulation of the electron transport through the single-molecule junction. With the single-molecule break junction techniques, including scanning tunneling microscope break junction technique and mechanically controllable break junction technique, the charge transport through various single-molecule and supramolecular junctions has been studied during the dynamic fabrication and continuous characterization of molecular junctions. This review starts from the charge transport characterization of supramolecular junctions through a variety of noncovalent interactions, such as hydrogen bond, π-π interaction, and electrostatic force. We further review the recent progress in constructing highly conductive molecular junctions via chemical reactions, the response of molecular junctions to external stimuli, as well as the application of break junction techniques in controlling and monitoring chemical reactions in situ. We suggest that beyond the measurement of single molecular conductance, the single-molecule break junction techniques provide a promising access to study molecular assembly and chemical reactions at the single-molecule scale.

Zinc Chromate Induces Chromosome Instability and DNA Double Strand Breaks in Human Lung Cells

PubMed Central

Xie, Hong; Holmes, Amie L.; Young, Jamie L.; Qin, Qin; Joyce, Kellie; Pelsue, Stephen C.; Peng, Cheng; Wise, Sandra S.; Jeevarajan, Antony S.; Wallace, William T.; Hammond, Dianne; Wise, John Pierce

2014-01-01

Hexavalent chromium Cr(VI) is a respiratory toxicant and carcinogen, with solubility playing an important role in its carcinogenic potential. Zinc chromate, a water insoluble or ‘particulate’ Cr(VI) compound, has been shown to be carcinogenic in epidemiology studies and to induce tumors in experimental animals, but its genotoxicity is poorly understood. Our study shows that zinc chromate induced concentration-dependent increases in cytotoxicity, chromosome damage and DNA double strand breaks in human lung cells. In response to zinc chromate-induced breaks, MRE11 expression was increased and ATM and ATR were phosphorylated, indicating that the DNA double strand break repair system was initiated in the cells. In addition, our data show that zinc chromate-induced double strand breaks were only observed in the G2/M phase population, with no significant amount of double strand breaks observed in G1 and S phase cells. These data will aid in understanding the mechanisms of zinc chromate toxicity and carcinogenesis. PMID:19027772

An Analysis of the Cost-Volume Relationships within the Aircraft Program of the Naval Air Rework Facility, Alameda, California.

DTIC Science & Technology

1986-06-01

INDIVIDUAL 22b TELEPHONE (include Area Code) 22c, OFFIcE YMBOI1. Thu . Lao(403) 646-255 1 o e DO FORM 1473,84 MAR 83 APR edition ray be used until...schedules are produced using projected direct labors hours available and established labor hour norms per aircraft. Since the actual workload is...and segment costs. (3) Use break-even analysis to compare revenues and costs and to evaluate relative profitability of the four aircraft program

Warm fog dissipation using large volume water sprays

NASA Technical Reports Server (NTRS)

Keller, Vernon W. (Inventor)

1988-01-01

To accomplish the removal of warm fog about an area such as an airport runway, a plurality of nozzles along a line adjacent the area propelled water jets through the fog to heights of approximately twenty-five meters. Each water jet breaks up forming a water drop size distribution that falls through the fog overtaking, colliding, and coalescing with individual fog droplets and thereby removes the fog. A water retrieval system is used to collect the water and return it to reservoirs for pumping it to the nozzles once again.

A Marine Aerosol Reference Tank system as a breaking wave analogue for the production of foam and sea-spray aerosols

NASA Astrophysics Data System (ADS)

Stokes, M. D.; Deane, G. B.; Prather, K.; Bertram, T. H.; Ruppel, M. J.; Ryder, O. S.; Brady, J. M.; Zhao, D.

2013-04-01

In order to better understand the processes governing the production of marine aerosols a repeatable, controlled method for their generation is required. The Marine Aerosol Reference Tank (MART) has been designed to closely approximate oceanic conditions by producing an evolving bubble plume and surface foam patch. The tank utilizes an intermittently plunging sheet of water and large volume tank reservoir to simulate turbulence, plume and foam formation, and the water flow is monitored volumetrically and acoustically to ensure the repeatability of conditions.

New Approaches to Planning for Emerging Long Term Threats. Volume 1. Text

DTIC Science & Technology

1993-12-01

aoaleuon of eudornmn. Wakx* au gd ~ fq~o re 1,c 1e n g e Oftburden. flo Washboon Hoodquernere Services. Oireclareft far hda "m &W a121v iani ann Oper Nne n...are fast-acting, short-lived in the environment, and yield no known toxic breakdown products.22 But because they are based on hydrofluoric acid , they...pose severe hazards to humans in the immediate target area who may come into contact I with the agent before it breaks down. Hydrofluoric acid (and the

Fuel breaks affect nonnative species abundance in Californian plant communities

USGS Publications Warehouse

Merriam, K.E.; Keeley, J.E.; Beyers, J.L.

2006-01-01

We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.

Processing Load Imposed by Line Breaks in English Temporal Wh-Questions.

PubMed

Hirotani, Masako; Terry, J Michael; Sadato, Norihiro

2016-01-01

Prosody plays an important role in online sentence processing both explicitly and implicitly. It has been shown that prosodically packaging together parts of a sentence that are interpreted together facilitates processing of the sentence. This applies not only to explicit prosody but also implicit prosody. The present work hypothesizes that a line break in a written text induces an implicit prosodic break, which, in turn, should result in a processing bias for interpreting English wh-questions. Two experiments-one self-paced reading study and one questionnaire study-are reported. Both supported the "line break" hypothesis mentioned above. The results of the self-paced reading experiment showed that unambiguous wh-questions were read faster when the location of line breaks (or frame breaks) matched the scope of a wh-phrase (main or embedded clause) than when they did not. The questionnaire tested sentences with an ambiguous wh-phrase, one that could attach either to the main or the embedded clause. These sentences were interpreted as attaching to the main clause more often than to the embedded clause when a line break appeared after the main verb, but not when it appeared after the embedded verb.

Role, perspective and knowledge of Iranian critical care nurses about breaking bad news.

PubMed

Imanipour, Masoomeh; Karim, Zahra; Bahrani, Naser

2016-05-01

Given the issue of caring critically ill patients, nurses are involved in the process of breaking bad news in critical care units, while little research has been conducted on this challenging issue. The purpose of this study was to determine the role, perspective and knowledge of Iranian critical care nurses regarding breaking bad news. This descriptive study was conducted on a sample of 160 nurses working in critical care units of hospitals affiliated to Tehran University of Medical Sciences. Stratified and quota sampling methods were used. The data collection tool was a four-part questionnaire with validity and reliability confirmed via content validity and test-retest, respectively. The study showed that most critical care nurses were involved in breaking bad news, with different roles. The majority of participants (91.2%) had a positive attitude towards involvement of nurses in breaking bad news. In this study, 78.8% of nurses had moderate knowledge about how to break bad news, and only a few had good level of knowledge (16.2%). According to the findings, while critical care nurses took different roles in the process of breaking bad news and they had positive attitude towards participation in this process, yet their knowledge about this process was inadequate. Thus, designing educational programmes to enhance critical care nurses' knowledge and skills in this area seems necessary. Copyright © 2015 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

On the generality of the mass sum rule

NASA Astrophysics Data System (ADS)

Polchinski, J.; Wise, Mark B.

1983-06-01

The sum rule, Σi(-1) 2 Ji(2 Ji+1) mi2=2 ΣaDaTr Qa, is studied to first order in supersymmetry breaking, treating the other interactions exactly. It is found to hold for spontaneous breaking and many types of explicit breaking.

Key Impact Factors on Dam Break Fatalities

NASA Astrophysics Data System (ADS)

Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

2016-12-01

Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

Phase-breaking effect on polaron transport in organic conjugated polymers

DOE PAGES

Meng, Ruixuan; Yin, Sun; Zheng, Yujun; ...

2017-06-15

Despite intense investigations and many accepted viewpoints on theory and experiment, the coherent and incoherent carrier transport in organic semiconductors remains an unsettled topic due to the strong electron-phonon coupling. Based on the tight-binding Su-Schrieffer-Heeger (SSH) model combined with a non-adiabatic dynamics method, we study the effect of phase-breaking on polaron transport by introducing a group of phase-breaking factors into π-electron wave-functions in organic conjugated polymers. Two approaches are applied: the modification of the transfer integral and the phase-breaking addition to the wave-function. Within the former, it is found that a single site phase-breaking can trap a polaron. However, withmore » a larger regular phase-breaking a polaron becomes more delocalized and lighter. Additionally, a group of disordered phase-breaking factors can make the polaron disperse in transport process. Within the latter approach, we show that the phase-breaking can render the delocalized state in valence band discrete and the state in the gap more localized. Consequently, the phase-breaking frequency and intensity can reduce the stability of a polaron. Furthermore, the phase-breaking in organic systems is the main factor that degrades the coherent transport and destroys the carrier stability.« less

Modelling wave-induced sea ice break-up in the marginal ice zone

NASA Astrophysics Data System (ADS)

Montiel, F.; Squire, V. A.

2017-10-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ.

Phase-breaking effect on polaron transport in organic conjugated polymers

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

Meng, Ruixuan; Yin, Sun; Zheng, Yujun

Despite intense investigations and many accepted viewpoints on theory and experiment, the coherent and incoherent carrier transport in organic semiconductors remains an unsettled topic due to the strong electron-phonon coupling. Based on the tight-binding Su-Schrieffer-Heeger (SSH) model combined with a non-adiabatic dynamics method, we study the effect of phase-breaking on polaron transport by introducing a group of phase-breaking factors into π-electron wave-functions in organic conjugated polymers. Two approaches are applied: the modification of the transfer integral and the phase-breaking addition to the wave-function. Within the former, it is found that a single site phase-breaking can trap a polaron. However, withmore » a larger regular phase-breaking a polaron becomes more delocalized and lighter. Additionally, a group of disordered phase-breaking factors can make the polaron disperse in transport process. Within the latter approach, we show that the phase-breaking can render the delocalized state in valence band discrete and the state in the gap more localized. Consequently, the phase-breaking frequency and intensity can reduce the stability of a polaron. Furthermore, the phase-breaking in organic systems is the main factor that degrades the coherent transport and destroys the carrier stability.« less

Modelling wave-induced sea ice break-up in the marginal ice zone

PubMed Central

Squire, V. A.

2017-01-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ. PMID:29118659

Modelling wave-induced sea ice break-up in the marginal ice zone.

PubMed

Montiel, F; Squire, V A

2017-10-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ.

Manufacturing of Low Cost, Durable Membrane Electrode Assemblies Engineered for Rapid Conditioning

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

Busby, Colin

Over the past 20 years significant progress in membrane-electrode assembly (MEA) technology development for polymer electrolyte fuel cells (PEMFCs) has resulted in the PEMFC technology approaching a commercial reality for transportation applications. However, there remain two primary technical challenges to be addressed in the MEA. First and foremost is meeting the automotive cost targets: Producing a fuel cell stack cost competitive with today’s internal combustion engine. In addition to the material cost, MEA (and other components) and stack assembly production methods must be amenable for use in low cost, high speed, automotive assembly line. One impediment to this latter goalmore » is that stack components must currently go through a long and tedious conditioning procedure before they produce optimal power. This so-called “break-in” can take many hours, and can involve quite complex voltage, temperature and/or pressure steps. These break-in procedures must be simplified and the time required reduced if fuel cells are to become a viable automotive engine. The second challenge is to achieve the durability targets in real-world automotive duty cycle operations. Significant improvements in cost, break-in time, and durability for the key component of fuel cell stacks, MEAs were achieved in this project. Advanced modeling was used to guide design of the new MEA to maximize performance and durability. A new, innovative process and manufacturing approach utilizing direct in-line coating using scalable, cost-competitive, continuous high volume 3-layer rolled-good manufacturing processes was developed and validated by single cell and short stack testing. In addition, the direct coating methods employed were shown to reduce the cost for sacrificial films. Furthermore, Gore has demonstrated a 10 µm reinforced membrane that is used in the new low-cost process and can meet automotive power density and durability targets. Across a wide range of operating conditions, the direct-coated MEA outperformed the commercial baseline MEA, and did so through a process that delivers MEAs at $92.35/m2 at a volume of 500,000 systems per year, according to Strategic Analysis (SA) estimates.« less

Adolescent externalizing behaviour, psychological control, and peer rejection: Transactional links and dopaminergic moderation.

PubMed

Janssens, Annelies; Van Den Noortgate, Wim; Goossens, Luc; Verschueren, Karine; Colpin, Hilde; Claes, Stephan; Van Heel, Martijn; Van Leeuwen, Karla

2017-09-01

This study investigated (1) reciprocal links among parental psychological control, peer rejection, and adolescent externalizing (aggressive and rule-breaking behaviour), and (2) the moderating effect of an adolescent genetic factor (biologically informed polygenic score for dopamine signalling). Three-year longitudinal data from 1,116 adolescents (51% boys; M age = 13.79) and their parents included psychological measures (adolescent-reported psychological control, peer-reported rejection, and parent-reported aggressive and rule-breaking behaviour). Cross-lagged analyses showed bidirectional effects between psychological control and both aggressive and rule-breaking behaviour and a unidirectional effect of peer rejection on both forms of problem behaviour over time. Multigroup structural equation modelling revealed genetic moderation only for rule-breaking behaviour: for adolescents with intermediate levels of dopamine signalling significant environmental effects were present, whereas adolescent effects of rule-breaking behaviour on psychological control were significant for adolescents with both intermediate and high profiles and effects on peer rejection only for adolescents with high dopamine profiles. Statement of contribution What is already known on this subject? Parental psychological control is related to adolescent externalizing problems. Experiencing peer rejection reinforces aggressive and rule-breaking behaviour. Single-gene studies show that dopaminergic genes influence externalizing problems directly or in interaction with the environment. What does this study add? Parental psychological control and adolescent aggressive and rule-breaking behaviour exacerbate one another longitudinally. Longitudinal associations between peer rejection and both subtypes of externalizing behaviour are unidirectional. With a polygenic approach, dopaminergic moderation is present for rule-breaking behaviour only. © 2017 The British Psychological Society.

The difficulties experienced by nurses and healthcare staff involved in the process of breaking bad news.

PubMed

Warnock, Clare; Buchanan, Jean; Tod, Angela Mary

2017-07-01

The aim of this study was to explore the difficulties experienced by nurses and healthcare professionals when engaging in the process of breaking bad news. The challenges faced by staff when breaking bad news have previously been researched in relation to particular settings or participants. This study involved staff from diverse settings and roles to develop broader insights into the range of difficulties experienced in clinical practice. The study used a descriptive survey design involving self-reported written accounts and framework analysis. Data were collected using a structured questionnaire containing a free text section that asked participants to describe a difficult experience they had encountered when involved in the process of breaking bad news. Data were collected from healthcare staff from hospital, community, hospice and care home settings attending training days on breaking bad news between April 2011 and April 2014. Multiple inter-related factors presented challenges to staff engaging in activities associated with breaking bad news. Traditional subjects such as diagnostic and treatment information were described but additional topics were identified such as the impact of illness and care at the end of life. A descriptive framework was developed that summarizes the factors that contribute to creating difficult experiences for staff when breaking bad news. The framework provides insights into the scope of the challenges faced by staff when they engage in the process of breaking bad news. This provides the foundation for developing interventions to support staff that more closely matches their experiences in clinical practice. © 2017 John Wiley & Sons Ltd.

Rock deformation equations and application to the study on slantingly installed disc cutter

NASA Astrophysics Data System (ADS)

Zhang, Zhao-Huang; Meng, Liang; Sun, Fei

2014-08-01

At present the mechanical model of the interaction between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the functional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke's law and analyze the effect of the slanting installation angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.

Physicochemical Behavior of Some Amino Acids/Glycylglycine in Aqueous D-Galactose Solutions at Different Temperatures

NASA Astrophysics Data System (ADS)

Ali, Anwar; Patel, Rajan; Shahjahan; Ansari, Nizamul Haque

2010-03-01

The apparent molar volumes {(overline{V_2})} for glycine (Gly), l-alanine (Ala), phenylalanine (Phe), and glycylglycine (Gly-Gly) in 0.10 m aqueous d-galactose solutions have been determined from density measurements at (298.15, 303.15, 308.15, and 313.15) K. The data for {(overline{V_2})} were utilized to estimate the partial molar volume at infinite dilution {(overline{V_2^0})} , and experimental slope {(S_v^ast)} . The transfer volume, {(overline{V2^0}_(tr))} , and hydration number, ( n H) were also evaluated. The viscosity data were used to evaluate A- and B-coefficients of the Jones-Dole equation, the free energy of activation of viscous flow per mole of the solvent {left(Δ μ1^{0ast} right)} and the solute {left(Δ μ 2^{0ast} right)} . The molar refractivity ( R D) was calculated from refractive index data. The results were discussed in terms of hydrophilic-ionic, hydrophilic-hydrophobic, and hydrophobic-hydrophobic interactions, and structure-making/-breaking ability of the solute (AAs/peptide) in aqueous d-galactose solutions.

Breaking Up is Hard to do: The Impact of Unmarried Relationship Dissolution on Mental Health and Life Satisfaction

PubMed Central

Rhoades, Galena K.; Kamp Dush, Claire M.; Atkins, David C.; Stanley, Scott M.; Markman, Howard J.

2011-01-01

This study was the first to examine the impact of unmarried relationship break-up on psychological distress and life satisfaction using a within-subjects design. Among unmarried 18 to 35-year olds (N = 1295), 36.5% had one or more break-ups over a 20-month period. Experiencing a break-up was associated with an increase in psychological distress and a decline in life satisfaction (from pre- to post-dissolution). In addition, several characteristics of the relationship or of the break-up were associated with the magnitude of the changes in life satisfaction following a break-up. Specifically, having been cohabiting and having had plans for marriage were associated with larger declines in life satisfaction while having begun to date someone new was associated with smaller declines. Interestingly, having higher relationship quality at the previous wave was associated with smaller declines in life satisfaction following a break-up. No relationship or break-up characteristics were significantly associated with the magnitude of changes in psychological distress after a break-up. Existing theories are used to explain the results. Implications for clinical work and future research on unmarried relationships are also discussed. PMID:21517174

Dedicated Perioperative Hip Fracture Comanagement Programs are Cost-effective in High-volume Centers: An Economic Analysis.

PubMed

Swart, Eric; Vasudeva, Eshan; Makhni, Eric C; Macaulay, William; Bozic, Kevin J

2016-01-01

Osteoporotic hip fractures are common injuries typically occurring in patients who are older and medically frail. Studies have suggested that creation of a multidisciplinary team including orthopaedic surgeons, internal medicine physicians, social workers, and specialized physical therapists, to comanage these patients can decrease complication rates, improve time to surgery, and reduce hospital length of stay; however, they have yet to achieve widespread implementation, partly owing to concerns regarding resource requirements necessary for a comanagement program. We performed an economic analysis to determine whether implementation of a comanagement model of care for geriatric patients with osteoporotic hip fractures would be a cost-effective intervention at hospitals with moderate volume. We also calculated what annual volume of cases would be needed for a comanagement program to "break even", and finally we evaluated whether universal or risk-stratified comanagement was more cost effective. Decision analysis techniques were used to model the effect of implementing a systems-based strategy to improve inpatient perioperative care. Costs were obtained from best-available literature and included salary to support personnel and resources to expedite time to the operating room. The major economic benefit was decreased initial hospital length of stay, which was determined via literature review and meta-analysis, and a health benefit was improvement in perioperative mortality owing to expedited preoperative evaluation based on previously conducted meta-analyses. A break-even analysis was conducted to determine the annual case volume necessary for comanagement to be either (1) cost effective (improve health-related quality of life enough to be worth additional expenses) or (2) result in cost savings (actually result in decreased total expenses). This calculation assumed the scenario in which a hospital could hire only one hospitalist (and therapist and social worker) on a full-time basis. Additionally, we evaluated the scenario where the necessary staff was already employed at the hospital and could be dedicated to a comanagement service on a part-time basis, and explored the effect of triaging only patients considered high risk to a comanagement service versus comanaging all geriatric patients. Finally, probabilistic sensitivity analysis was conducted on all critical variables, with broad ranges used for values around which there was higher uncertainty. For the base case, universal comanagement was more cost effective than traditional care and risk-stratified comanagement (incremental cost effectiveness ratios of USD 41,100 per quality-adjusted life-year and USD 81,900 per quality-adjusted life-year, respectively). Comanagement was more cost effective than traditional management as long as the case volume was more than 54 patients annually (range, 41-68 patients based on sensitivity analysis) and resulted in cost savings when there were more than 318 patients annually (range, 238-397 patients). In a scenario where staff could be partially dedicated to a comanagement service, universal comanagement was more cost effective than risk-stratified comanagement (incremental cost effectiveness of USD 2300 per quality-adjusted life-year), and both comanagement programs had lower costs and better outcomes compared with traditional management. Sensitivity analysis was conducted and showed that the level of uncertainty in key variables was not high enough to change the core conclusions of the model. Implementation of a systems-based comanagement strategy using a dedicated team to improve perioperative medical care and expedite preoperative evaluation is cost effective in hospitals with moderate volume and can result in cost savings at higher-volume centers. The optimum patient population for a comanagement strategy is still being defined. Level 1, Economic and Decision Analysis.

Model-Data Assimilation of Internal Waves during ASIAEX-2001

NASA Technical Reports Server (NTRS)

Liu, Antony; Zhao, Yun-He; Tang, T. Y.; Ramp, Steven R.

2003-01-01

In recent Asian Seas International Acoustics Experiment (ASIAEX), extensive moorings have been deployed around the continental shelf break area in the northeast of South China Sea in May 2001. Simultaneous RADARSAT SAR images have been collected during the field test to integrate with the in-situ measurements from moorings, ship-board sensors, and CTD casts. Besides it provides synoptic information, satellite imagery is very useful for tracking the internal waves, and locating surface fronts and mesoscale features. During ASIAEX in May 2001, many large internal waves were observed at the test area and were the major oceanic features for acoustic volume interaction. Based on the internal wave distribution maps compiled from satellite data, the wave crest can be as long as 200 km with amplitude of 100 m. Environmental parameters have been calculated based on extensive CTD casts data near the ASIAEX area. Nonlinear internal wave models have been applied to integrate and assimilate both SAR and mooring data. Using SAR data in deep water as an initial condition, numerical simulations produce the wave evolution on the continental shelf and compared reasonably well with the mooring measurements at the downstream station. The shoaling, turning, and dissipation of large internal waves on the shelf break, elevation solitons, and wave-wave interaction have been studied and are very important issues for acoustic propagation. The internal wave effects on acoustic modal coupling has been implicated and discussed.

Numerical simulation of two-phase flow for sediment transport in the inner-surf and swash zones

NASA Astrophysics Data System (ADS)

Bakhtyar, R.; Barry, D. A.; Yeganeh-Bakhtiary, A.; Li, L.; Parlange, J.-Y.; Sander, G. C.

2010-03-01

A two-dimensional two-phase flow framework for fluid-sediment flow simulation in the surf and swash zones was described. Propagation, breaking, uprush and backwash of waves on sloping beaches were studied numerically with an emphasis on fluid hydrodynamics and sediment transport characteristics. The model includes interactive fluid-solid forces and intergranular stresses in the moving sediment layer. In the Euler-Euler approach adopted, two phases were defined using the Navier-Stokes equations with interphase coupling for momentum conservation. The k-ɛ closure model and volume of fluid approach were used to describe the turbulence and tracking of the free surface, respectively. Numerical simulations explored incident wave conditions, specifically spilling and plunging breakers, on both dissipative and intermediate beaches. It was found that the spatial variation of sediment concentration in the swash zone is asymmetric, while the temporal behavior is characterized by maximum sediment concentrations at the start and end of the swash cycle. The numerical results also indicated that the maximum turbulent kinetic energy and sediment flux occurs near the wave-breaking point. These predictions are in general agreement with previous observations, while the model describes the fluid and sediment phase characteristics in much more detail than existing measurements. With direct quantifications of velocity, turbulent kinetic energy, sediment concentration and flux, the model provides a useful approach to improve mechanistic understanding of hydrodynamic and sediment transport in the nearshore zone.

Inferring diameters of spheres and cylinders using interstitial water.

PubMed

Herrera, Sheryl L; Mercredi, Morgan E; Buist, Richard; Martin, Melanie

2018-06-04

Most early methods to infer axon diameter distributions using magnetic resonance imaging (MRI) used single diffusion encoding sequences such as pulsed gradient spin echo (SE) and are thus sensitive to axons of diameters > 5 μm. We previously simulated oscillating gradient (OG) SE sequences for diffusion spectroscopy to study smaller axons including the majority constituting cortical connections. That study suggested the model of constant extra-axonal diffusion breaks down at OG accessible frequencies. In this study we present data from phantoms to test a time-varying interstitial apparent diffusion coefficient. Diffusion spectra were measured in four samples from water packed around beads of diameters 3, 6 and 10 μm; and 151 μm diameter tubes. Surface-to-volume ratios, and diameters were inferred. The bead pore radii estimates were 0.60±0.08 μm, 0.54±0.06 μm and 1.0±0.1 μm corresponding to bead diameters ranging from 2.9±0.4 μm to 5.3±0.7 μm, 2.6±0.3 μm to 4.8±0.6 μm, and 4.9±0.7 μm to 9±1 μm. The tube surface-to-volume ratio estimate was 0.06±0.02 μm -1 corresponding to a tube diameter of 180±70 μm. Interstitial models with OG inferred 3-10 μm bead diameters from 0.54±0.06 μm to 1.0±0.1 μm pore radii and 151 μm tube diameters from 0.06±0.02 μm -1 surface-to-volume ratios.

Genetic determinism of bone and mineral metabolism in meat-type chickens: A QTL mapping study.

PubMed

Mignon-Grasteau, Sandrine; Chantry-Darmon, Céline; Boscher, Marie-Yvonne; Sellier, Nadine; Chabault-Dhuit, Marie; Le Bihan-Duval, Elisabeth; Narcy, Agnès

2016-12-01

Skeletal integrity in meat-type chickens is affected by many factors including rapid growth rate, nutrition and genetics. To investigate the genetic basis of bone and mineral metabolism, a QTL detection study was conducted in an intercross between two lines of meat-type chickens divergently selected for their high (D +) or low (D -) digestive efficiency. Tibia size (length, diameter, volume) and ash content were determined at 3 weeks of age as well as phosphorus (P) retention and plasma concentration. Heritability of these traits and their genetic correlations with digestive efficiency were estimated. A QTL mapping study was performed using 3379 SNP markers. Tibia size, weight, ash content and breaking strength were highly heritable (0.42 to 0.61). Relative tibia diameter and volume as well as P retention were strongly and positively genetically correlated with digestive efficiency (0.57 to 0.80). A total of 35 QTL were identified (9 for tibia weight, 13 for tibia size, 5 for bone strength, 5 for bone mineralization, 2 for plasma P concentration and 1 for P retention). Six QTL were genome-wide significant, and 3 QTL for tibia relative volume, weight and ash weight on chromosome 6 were fixed, the positive allele coming from the D-line. For two QTL for ash content on chromosome 18 and relative tibia length on chromosome 26, the confidence intervals were small enough to identify potential candidate genes. These findings support the evidence of multiple genetic loci controlling bone and mineral metabolism. The identification of candidate genes may provide new perspectives in the understanding of bone regulation, even beyond avian species.

Stalking perpetrators and psychological maltreatment of partners: anger-jealousy, attachment insecurity, need for control, and break-up context.

PubMed

Davis, K E; Ace, A; Andra, M

2000-01-01

Two studies of the correlates of self-reported courtship persistence, stalking-like behaviors following a relationship break-up, and psychological maltreatment of partners were conducted in samples of male (N = 46 and 93) and female (N = 123 and 110) college students. Approximately 40% (38.5% and 44.6%) engaged in at least one stalking behavior following a break-up. A total of 10.7% (study 1) and 7.6% (study 2) engaged in 6 or more stalking behaviors. Stalking was significantly related to psychological maltreatment of the partner (PMP) prior to the break-up. Being the recipient of the breakup was associated with feelings of anger, jealousy and obsessiveness and with higher levels of courtship persistence, and stalking. A replicated path model showed that anxious attachment and need for control were related to PMP and that need for control had a direct contribution to stalking. For anxious attachment, its connection to stalking was indirect, mediated by the degree of anger-jealousy over the break-up.

The Effects of Spacing, Naps, and Fatigue on the Acquisition and Retention of Laparoscopic Skills.

PubMed

Spruit, Edward N; Band, Guido P H; van der Heijden, Kristiaan B; Hamming, Jaap F

Earlier research has shown that laparoscopic skills are trained more efficiently on a spaced schedule compared to a massed schedule. The aim of the study was to estimate to what extent the spacing interval, naps, and fatigue influenced the effectiveness of spacing laparoscopy training. Overall 4 groups of trainees (aged 17-41y; 72% female; N massed = 40; N break = 35; N break-nap = 37; N spaced = 37) without prior experience were trained in 3 laparoscopic tasks using a physical box trainer with different scheduling interventions. The first (massed) group received three 100-minute training sessions consecutively on a single day. The second (break) group received the sessions interrupted with two 45-minute breaks. The third (break-nap) group had the same schedule as the second group, but had two 35-minute powernap intervals during the breaks. The fourth (spaced) group had the 3 sessions on 3 consecutive days. A retention session was organized approximately 3 months after training. The results showed an overall pattern of superior performance at the end of training and at retention for the spaced group, followed by the break-nap, break, and massed group, respectively. The spaced and break-nap group significantly outperformed the break and massed group, with effect sizes ranging from 0.20 to 0.37. Spacing laparoscopic training over 3 consecutive days or weeks is superior to massed training, even if the massed training contains breaks. Breaks with sleep opportunity (i.e., lying, inactive, and muted sensory input) enhance performance over training with regular breaks and traditional massed training. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Modeling the safety impacts of driving hours and rest breaks on truck drivers considering time-dependent covariates.

PubMed

Chen, Chen; Xie, Yuanchang

2014-12-01

Driving hours and rest breaks are closely related to driver fatigue, which is a major contributor to truck crashes. This study investigates the effects of driving hours and rest breaks on commercial truck driver safety. A discrete-time logistic regression model is used to evaluate the crash odds ratios of driving hours and rest breaks. Driving time is divided into 11 one hour intervals. These intervals and rest breaks are modeled as dummy variables. In addition, a Cox proportional hazards regression model with time-dependent covariates is used to assess the transient effects of rest breaks, which consists of a fixed effect and a variable effect. Data collected from two national truckload carriers in 2009 and 2010 are used. The discrete-time logistic regression result indicates that only the crash odds ratio of the 11th driving hour is statistically significant. Taking one, two, and three rest breaks can reduce drivers' crash odds by 68%, 83%, and 85%, respectively, compared to drivers who did not take any rest breaks. The Cox regression result shows clear transient effects for rest breaks. It also suggests that drivers may need some time to adjust themselves to normal driving tasks after a rest break. Overall, the third rest break's safety benefit is very limited based on the results of both models. The findings of this research can help policy makers better understand the impact of driving time and rest breaks and develop more effective rules to improve commercial truck safety. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

Universality in volume-law entanglement of scrambled pure quantum states.

PubMed

Nakagawa, Yuya O; Watanabe, Masataka; Fujita, Hiroyuki; Sugiura, Sho

2018-04-24

A pure quantum state can fully describe thermal equilibrium as long as one focuses on local observables. The thermodynamic entropy can also be recovered as the entanglement entropy of small subsystems. When the size of the subsystem increases, however, quantum correlations break the correspondence and mandate a correction to this simple volume law. The elucidation of the size dependence of the entanglement entropy is thus essentially important in linking quantum physics with thermodynamics. Here we derive an analytic formula of the entanglement entropy for a class of pure states called cTPQ states representing equilibrium. We numerically find that our formula applies universally to any sufficiently scrambled pure state representing thermal equilibrium, i.e., energy eigenstates of non-integrable models and states after quantum quenches. Our formula is exploited as diagnostics for chaotic systems; it can distinguish integrable models from non-integrable models and many-body localization phases from chaotic phases.

Hadronic vacuum polarization contribution to aμ from full lattice QCD

NASA Astrophysics Data System (ADS)

Chakraborty, Bipasha; Davies, C. T. H.; de Oliveira, P. G.; Koponen, J.; Lepage, G. P.; van de Water, R. S.; Hpqcd Collaboration

2017-08-01

We determine the contribution to the anomalous magnetic moment of the muon from the αQED2 hadronic vacuum polarization diagram using full lattice QCD and including u /d quarks with physical masses for the first time. We use gluon field configurations that include u , d , s and c quarks in the sea at multiple values of the lattice spacing, multiple u /d masses and multiple volumes that allow us to include an analysis of finite-volume effects. We obtain a result for aμHVP ,LO of 667 (6 )(12 )×10-10, where the first error is from the lattice calculation and the second includes systematic errors from missing QED and isospin-breaking effects and from quark-line disconnected diagrams. Our result implies a discrepancy between the experimental determination of aμ and the Standard Model of 3 σ .

Deformation Failure Characteristics of Coal Body and Mining Induced Stress Evolution Law

PubMed Central

Wen, Zhijie; Wen, Jinhao; Shi, Yongkui; Jia, Chuanyang

2014-01-01

The results of the interaction between coal failure and mining pressure field evolution during mining are presented. Not only the mechanical model of stope and its relative structure division, but also the failure and behavior characteristic of coal body under different mining stages are built and demonstrated. Namely, the breaking arch and stress arch which influence the mining area are quantified calculated. A systematic method of stress field distribution is worked out. All this indicates that the pore distribution of coal body with different compressed volume has fractal character; it appears to be the linear relationship between propagation range of internal stress field and compressed volume of coal body and nonlinear relationship between the range of outburst coal mass and the number of pores which is influenced by mining pressure. The results provide theory reference for the research on the range of mining-induced stress and broken coal wall. PMID:24967438

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor; Silin, Dimitriy Borisovic; De, Asoke Kumar

2005-06-07

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor [Oakland, CA; Silin, Dimitriy Borisovich [Pleasant Hill, CA; De, Asoke Kumar [San Jose, CA

2007-07-24

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

Fibre inflation and α-attractors

NASA Astrophysics Data System (ADS)

Kallosh, Renata; Linde, Andrei; Roest, Diederik; Westphal, Alexander; Yamada, Yusuke

2018-02-01

Fibre inflation is a specific string theory construction based on the Large Volume Scenario that produces an inflationary plateau. We outline its relation to α-attractor models for inflation, with the cosmological sector originating from certain string theory corrections leading to α = 2 and α = 1/2. Above a certain field range, the steepening effect of higher-order corrections leads first to the breakdown of single-field slow-roll and after that to the onset of 2-field dynamics: the overall volume of the extra dimensions starts to participate in the effective dynamics. Finally, we propose effective supergravity models of fibre inflation based on an \\overline{D3} uplift term with a nilpotent superfield. Specific moduli dependent \\overline{D3} induced geometries lead to cosmological fibre models but have in addition a de Sitter minimum exit. These supergravity models motivated by fibre inflation are relatively simple, stabilize the axions and disentangle the Hubble parameter from supersymmetry breaking.

Examining the Knowledge and Capacity of Elementary Teachers to Implement Classroom Physical Activity Breaks

ERIC Educational Resources Information Center

Dinkel, Danae M.; Lee, Jung-Min; Schaffer, Connie

2016-01-01

This study examined teachers' zone of proximal development for classroom physical activity breaks by assessing teachers' knowledge and capacity for implementing classroom physical activity breaks. Five school districts of various sizes (n = 346 teachers) took part in a short online survey. Descriptive statistics were calculated and chi-square…

Physical Activity Opportunities during the School Day: Classroom Teachers' Perceptions of Using Activity Breaks in the Classroom

ERIC Educational Resources Information Center

McMullen, Jaimie; Kulinna, Pamela; Cothran, Donetta

2014-01-01

The purpose of this study was to explore classroom teachers' perceptions of incorporating physical activity breaks into their classroom and to determine specific features of preferred activity breaks. These perceptions are considered within the conceptual framework of Comprehensive School Physical Activity Program (CSPAP). Twelve elementary and…

Numerical modelling of wind effects on breaking waves in the surf zone

NASA Astrophysics Data System (ADS)

Xie, Zhihua

2017-10-01

Wind effects on periodic breaking waves in the surf zone have been investigated in this study using a two-phase flow model. The model solves the Reynolds-averaged Navier-Stokes equations with the k - 𝜖 turbulence model simultaneously for the flows both in the air and water. Both spilling and plunging breakers over a 1:35 sloping beach have been studied under the influence of wind, with a focus during wave breaking. Detailed information of the distribution of wave amplitudes and mean water level, wave-height-to-water-depth ratio, the water surface profiles, velocity, vorticity, and turbulence fields have been presented and discussed. The inclusion of wind alters the air flow structure above water waves, increases the generation of vorticity, and affects the wave shoaling, breaking, overturning, and splash-up processes. Wind increases the water particle velocities and causes water waves to break earlier and seaward, which agrees with the previous experiment.

Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

PubMed

Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

Experimental Research on the Dam-Break Mechanisms of the Jiadanwan Landslide Dam Triggered by the Wenchuan Earthquake in China

PubMed Central

Xu, Fu-gang; Yang, Xing-guo; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation. PMID:23844387

Assessment of chemical dispersant effectiveness in a wave tank under regular non-breaking and breaking wave conditions.

PubMed

Li, Zhengkai; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2008-05-01

Current chemical dispersant effectiveness tests for product selection are commonly performed with bench-scale testing apparatus. However, for the assessment of oil dispersant effectiveness under real sea state conditions, test protocols are required to have hydrodynamic conditions closer to the natural environment, including transport and dilution effects. To achieve this goal, Fisheries and Oceans Canada and the US Environmental Protection Agency (EPA) designed and constructed a wave tank system to study chemical dispersant effectiveness under controlled mixing energy conditions (regular non-breaking, spilling breaking, and plunging breaking waves). Quantification of oil dispersant effectiveness was based on observed changes in dispersed oil concentrations and oil-droplet size distribution. The study results quantitatively demonstrated that total dispersed oil concentration and breakup kinetics of oil droplets in the water column were strongly dependent on the presence of chemical dispersants and the influence of breaking waves. These data on the effectiveness of dispersants as a function of sea state will have significant implications in the drafting of future operational guidelines for dispersant use at sea.

Vertical Variability of Anoxia Along the Northern Omani Shelf.

NASA Astrophysics Data System (ADS)

Queste, B. Y.; Piontkovski, S.; Heywood, K. J.

2016-02-01

Three autonomous underwater gliders were deployed along a 80 km transect extending from Muscat out into the Gulf during both monsoons and the intermonsoon season as part of a project funded by ONR Global and the UK NERC. The gliders surveyed the top 1000m across the continental shelf, the steep continental slope, and the Sea of Oman while measuring temperature, salinity, oxygen, chlorophyll a fluorescence, optical backscatter, photosyntheticall active radiation and providing estimates of depth-averaged currents and up/downwelling. The data show the depth of the surface oxycline varying by 50m across the transect as a function of mixed layer depth. Below, we observed high variability, on the order of days, in the oxygen profile with the boundary of the suboxic zone (< 6 µmol.kg-1) varying by up to 250m. This upper boundary was determined by the volume of the Persian Gulf Water (PGW) outflow which travels along the shelf edge. Below 400m, oxygen concentrations reached levels below 1 µmol.kg-1. The physical drivers of PGW transport therefore double, or reduce by half, the available habitat for macrofauna. The across-shelf transect allowed estimation of along-slope transport and variability of the PGW, identified by its higher salinity, temperature, optical backscatter and oxygen content. The structure and volume of the outflow was highly variable. During peak outflow, the core extended beyond the glider transect. During periods of minimal flow, it was constrained to 10km beyond the shelf break. PGW was also present in mesoscale eddies beyond the shelf break.

Economic analysis of bedside ultrasonography (US) implementation in an Internal Medicine department.

PubMed

Testa, Americo; Francesconi, Andrea; Giannuzzi, Rosangela; Berardi, Silvia; Sbraccia, Paolo

2015-12-01

The economic crisis, the growing healthcare demand, and Defensive Medicine wastefulness, strongly recommend the restructuring of the entire medical network. New health technology, such as bedside ultrasonography, might successfully integrate the clinical approach optimizing the use of limited resources, especially in a person-oriented vision of medicine. Bedside ultrasonography is a safe and reliable technique, with worldwide expanding employment in various clinical settings, being considered as "the stethoscope of the 21st century". However, at present, bedside ultrasonography lacks economic analysis. We performed a Cost-Benefit Analysis "ex ante", with a break-even point computing, of bedside ultrasonography implementation in an Internal Medicine department in the mid-term. Number and kind estimation of bedside ultrasonographic studies were obtained by a retrospective study, whose data results were applied to the next 3-year period (foresight study). All 1980 foreseen bedside examinations, with prevailing multiorgan ultrasonographic studies, were considered to calculate direct and indirect costs, while specific and generic revenues were considered only after the first semester. Physician professional training, equipment purchase and working time represented the main fixed and variable cost items. DRG increase/appropriateness, hospitalization stay shortening and reduction of traditional ultrasonography examination requests mainly impacted on calculated revenues. The break-even point, i.e. the volume of activity at which revenues exactly equal total incurred costs, was calculated to be 734 US examinations, corresponding to € 81,998 and the time considered necessary to reach it resulting 406 days. Our economic analysis clearly shows that bedside ultrasonography implementation in clinical daily management of an Internal Medicine department can produce consistent savings, or economic profit according to managerial choices (i.e., considering public or private targets), other than evident medical benefits.

The implications of high-quality staff break areas for nurses' health, performance, job satisfaction and retention.

PubMed

Nejati, Adeleh; Rodiek, Susan; Shepley, Mardelle

2016-05-01

The main study objective was to explore policy and design factors contributing to nurses' perception of how well-designed staff break areas can play an important beneficial role in relation to their overall job satisfaction, retention, performance and job-related health concerns. Nurses are extremely valuable to the healthcare industry; however, today's nursing profession is challenged by nurses' fatigue and its negative consequences on nurses' health and the quality of patient care they provide. Preliminary interviews were conducted with 10 nurses who worked as consultants in the healthcare design and construction industry. Based on findings, an online survey was developed and distributed to over 10 000 members of the Academy of Medical-Surgical Nurses in the United States. The majority of nurses viewed high-quality break spaces as 'fairly' or 'very' important in terms of their potential to positively influence staff, patient and facility outcomes. Stress, rest breaks and the quality of break areas were some of the significant factors contributing to their perception. The results of this empirical study support the conclusion that improvements in healthcare facility policies regarding staff breaks, as well as the creation of better-designed break areas, can be of significant benefit for nurses and the patients that they serve. © 2015 John Wiley & Sons Ltd.

Rule breaking mediates the developmental association between GABRA2 and adolescent substance abuse.

PubMed

Trucco, Elisa M; Villafuerte, Sandra; Heitzeg, Mary M; Burmeister, Margit; Zucker, Robert A

2014-12-01

This study's primary aim was to examine age-specific associations between GABRA2, rule breaking, problematic alcohol use, and substance abuse symptomatology. The secondary aim was to examine the extent to which rule breaking mediates the GABRA2-substance abuse relationship. A sample (n = 518) of primarily male (70.9%) and White (88.8%) adolescents from the Michigan Longitudinal Study was assessed from ages 11-18. Age-specific effects of GABRA2 on rule breaking, problematic alcohol use, and substance abuse symptomatology were examined using nested path models. The role of rule breaking as a mediator in the association between GABRA2 and substance abuse outcomes was tested using prospective cross-lagged path models. GABRA2 is significantly (p < 0.05) associated with rule breaking in mid- to late-adolescence, but not substance abuse symptomatology across adolescence. GABRA2 effects on problematic alcohol use and substance abuse symptomatology operate largely (45.3% and 71.1%, respectively, p < 0.05) via rule breaking in midadolescence. GABRA2 represents an early risk factor for an externalizing pathway to the development of problematic alcohol and drug use. © 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.

Biomechanical characterization of a low density silicone elastomer filled with hollow microspheres for maxillofacial prostheses.

PubMed

Liu, Q; Shao, L Q; Xiang, H F; Zhen, D; Zhao, N; Yang, S G; Zhang, X L; Xu, J

2013-01-01

An ideal material for maxillofacial prostheses has not been found. We created a novel material: silicone elastomer filled with hollow microspheres and characterized its biomechanical properties. Expancel hollow microspheres were mixed with MDX4-4210 silicone elastomer using Q7-9180 silicone fluid as diluent. The volume fractions of microspheres were 0, 5, 15, and 30% v/v (volume ratio to the total volume of MDX4-4210 and microspheres). The microspheres dispersed well in the matrix. The physical properties and biocompatibility of the composites were examined. Shock absorption was the greatest by the 5% v/v composite, and decreased with increasing concentrations of microspheres. The density, thermal conductivity, Shore A hardness, tear and tensile strength decreased with increasing concentrations of microspheres, while elongation at break increased. Importantly, the tear strength of all composites was markedly lower than that of pure silicone elastomer. Cell viability assays indicated that the composite was of good biocompatibility. The composite with a volume fraction of 5% exhibited the optimal properties for use as a maxillofacial prosthesis, though its tear strength was markedly lower than that of silicone elastomer. In conclusion, we developed a novel light and soft material with good flexibility and biocompatibility, which holds a promising prospect for clinical application as maxillofacial prosthesis.

Evaluation of Planned Treatment Breaks During Radiation Therapy for Anal Cancer: Update of RTOG 92-08

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

Konski, Andre; Garcia, Miguel; John, Madhu

2008-09-01

Purpose: Radiation Therapy Oncology Group (RTOG) 92-08 began as a single arm, Phase II trial for patients with anal cancer consisting of radiation (RT) + 5-flourouracil + mitomycin-C with a mandatory 2-week break and was amended after completion to evaluate the same treatment regimen without a treatment break. Long-term efficacy and late toxicity reporting are the specific aims of this study. Methods and Materials: Survivals were estimated with the Kaplan-Meier method. Overall survival (OS) was compared with RTOG 87-04 with the log-rank test. Time to local failure, regional failure, locoregional failure (LRF), distant metastases, second primary, and colostomy failure weremore » estimated by the cumulative incidence method. LRF was compared with RTOG 87-04 using the Gray's test. Results: Forty-seven patients entered in the mandatory treatment break cohort. The study was reopened in 1995 to the no mandatory treatment break cohort completing accrual with 20 patients in 1996. Of 67 total patients, 1 patient in the mandatory treatment break portion of the study did not receive any protocol treatment and is excluded from analyses. After adjusting for tumor size, neither cohort showed a statistically significant difference in OS or LRF compared with the RTOG 87-04 mitomycin-C arm. No patient in either cohort experienced a Grade 3 or higher late toxicity. Conclusions: No statistically significant differences were seen in OS or LRF when compared to the mitomycin-C arm of RTOG 87-04, but the sample sizes for the mandatory break cohort and the no mandatory break cohort are small. Late toxicity was low and similar for the treatment cohorts.« less

Differential Effects of Music and Video Gaming During Breaks on Auditory and Visual Learning.

PubMed

Liu, Shuyan; Kuschpel, Maxim S; Schad, Daniel J; Heinz, Andreas; Rapp, Michael A

2015-11-01

The interruption of learning processes by breaks filled with diverse activities is common in everyday life. This study investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on auditory versus visual memory performance. Young adults were exposed to breaks involving (a) open eyes resting, (b) listening to music, and (c) playing a video game, immediately after memorizing auditory versus visual stimuli. To assess learning performance, words were recalled directly after the break (an 8:30 minute delay) and were recalled and recognized again after 7 days. Based on linear mixed-effects modeling, it was found that playing the Angry Birds video game during a short learning break impaired long-term retrieval in auditory learning but enhanced long-term retrieval in visual learning compared with the music and rest conditions. These differential effects of video games on visual versus auditory learning suggest specific interference of common break activities on learning.

Skills Associated with Line Breaks in Elite Rugby Union

PubMed Central

den Hollander, Steve; Brown, James; Lambert, Michael; Treu, Paul; Hendricks, Sharief

2016-01-01

The ability of the attacking team to break through the defensive line is a key indicator of success as it creates opportunities to score tries. The aim of this study was to analyse line breaks and identify the associated skills and playing characteristics. The 2013 Super Rugby season (125 games) was analysed, in which 362 line breaks were identified and coded using variables that assessed team patterns and non-contact attacking skills in the phases preceding the line break. There was an average of 3 line breaks per game, with 39% of line breaks resulting in a try. Line breaks occurred when the ball-carrier was running fast [61%, x2(4) = 25.784, p = 0.000, Cramer’s v = 0.1922, weak]. At a moderate distance, short lateral passes (19%) and skip passes (15%) attributed to the highest percentage of line breaks [x2(26) = 50.899, p = 0.036, Cramer’s v = 0.2484, moderate]. Faster defensive line speeds resulted in more line breaks [x2(12) = 61.703, p < 0.001, Cramer’s v = 0.3026, moderate]. Line breaks are associated with overall team success and try scoring opportunities. Awareness of the defenders line speed and depth, fast running speed when receiving the ball and quick passing between attackers to the outside backs creates line break opportunities. During training, coaches should emphasise the movement speed of the ball between attackers and manipulate the speed and distance of the defenders. Key points Line breaks are associated with overall team success and try scoring opportunities. Awareness of the defenders line speed and depth, fast running speed when receiving the ball and quick passing between attackers to the outside backs creates line break opportunities During training, coaches should emphasise the movement speed of the ball between attackers and manipulate the speed and distance of the defenders. PMID:27803629

Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems.

PubMed

Sharif-Kashani, Pooria; Fanney, Douglas; Injev, Val

2014-07-30

Occlusion break surge during phacoemulsification cataract surgery can lead to potential surgical complications. The purpose of this study was to quantify occlusion break surge and vacuum rise time of current phacoemulsification systems used in cataract surgery. Occlusion break surge at vacuum pressures between 200 and 600 mmHg was assessed with the Infiniti® Vision System, the WhiteStar Signature® Phacoemulsification System, and the Centurion® Vision System using gravity-fed fluidics. Centurion Active FluidicsTM were also tested at multiple intraoperative pressure target settings. Vacuum rise time was evaluated for Infiniti, WhiteStar Signature, Centurion, and Stellaris® Vision Enhancement systems. Rise time to vacuum limits of 400 and 600 mmHg was assessed at flow rates of 30 and 60 cc/minute. Occlusion break surge was analyzed by 2-way analysis of variance. The Centurion system exhibited substantially less occlusion break surge than the other systems tested. Surge area with Centurion Active Fluidics was similar to gravity fluidics at an equivalent bottle height. At all Centurion Active Fluidics intraoperative pressure target settings tested, surge was smaller than with Infiniti and WhiteStar Signature. Infiniti had the fastest vacuum rise time and Stellaris had the slowest. No system tested reached the 600-mmHg vacuum limit. In this laboratory study, Centurion had the least occlusion break surge and similar vacuum rise times compared with the other systems tested. Reducing occlusion break surge may increase safety of phacoemulsification cataract surgery.

Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems

PubMed Central

2014-01-01

Background Occlusion break surge during phacoemulsification cataract surgery can lead to potential surgical complications. The purpose of this study was to quantify occlusion break surge and vacuum rise time of current phacoemulsification systems used in cataract surgery. Methods Occlusion break surge at vacuum pressures between 200 and 600 mmHg was assessed with the Infiniti® Vision System, the WhiteStar Signature® Phacoemulsification System, and the Centurion® Vision System using gravity-fed fluidics. Centurion Active FluidicsTM were also tested at multiple intraoperative pressure target settings. Vacuum rise time was evaluated for Infiniti, WhiteStar Signature, Centurion, and Stellaris® Vision Enhancement systems. Rise time to vacuum limits of 400 and 600 mmHg was assessed at flow rates of 30 and 60 cc/minute. Occlusion break surge was analyzed by 2-way analysis of variance. Results The Centurion system exhibited substantially less occlusion break surge than the other systems tested. Surge area with Centurion Active Fluidics was similar to gravity fluidics at an equivalent bottle height. At all Centurion Active Fluidics intraoperative pressure target settings tested, surge was smaller than with Infiniti and WhiteStar Signature. Infiniti had the fastest vacuum rise time and Stellaris had the slowest. No system tested reached the 600-mmHg vacuum limit. Conclusions In this laboratory study, Centurion had the least occlusion break surge and similar vacuum rise times compared with the other systems tested. Reducing occlusion break surge may increase safety of phacoemulsification cataract surgery. PMID:25074069

Impact of rest breaks on musculoskeletal discomfort of Chikan embroiderers of West Bengal, India: a follow up field study

PubMed Central

Chakrabarty, Sabarni; Sarkar, Krishnendu; Dev, Samrat; Das, Tamal; Mitra, Kalpita; Sahu, Subhashis; Gangopadhyay, Somnath

2016-01-01

Objectives: This study aimed to determine risk factors that predict musculoskeletal discomfort in Chikan embroiderers of West Bengal, India, and to compare the effect of two rest break schedules to reduce these symptoms. Methods: The Nordic musculoskeletal questionnaire was performed on 400 Chikan embroiderers at baseline containing questions on job autonomy, working behavior, and work stress factors. Relative risk was calculated to identify prognostic factors for musculoskeletal discomfort in different body regions. Two groups of workers received two rest break schedules for 4 months and compared in a between-subject design. Outcome variables were scores of Body Part Discomfort (BPD) scale. Results: Chikan embroiderers are afflicted with musculoskeletal discomfort mainly in the lower back, neck/shoulder and wrist/forearm region, which is attributed to their prolonged working timeinvolving hands and wrists, being in a static seating posture. Rigidity in working methods, prolonged working time, inadequate rest break during the working day, dissatisfaction regarding earning, monotonous work, static sitting posture, and repetitive movement of wrist and forearm were the significant predictors of these symptom developments. Rest break schedule 1 with more frequent and shorter breaks had more significant improvement on the severity of these musculoskeletal discomforts. Conclusions: Chikan embroiderers perform a highly dreary occupation and various ergonomics conditions work as predictors for developing musculoskeletal discomforts among them. Design of proper rest break schedule involving shorter and frequent breaks was competent for reducing these discomforts to a certain extent. PMID:27265529

The difference in LET and ion species dependence for induction of initially measured and non-rejoined chromatin breaks in normal human fibroblasts.

PubMed

Tsuruoka, Chizuru; Suzuki, Masao; Hande, M Prakash; Furusawa, Yoshiya; Anzai, Kazunori; Okayasu, Ryuichi

2008-08-01

We studied the LET and ion species dependence of the induction of chromatin breaks measured immediately after irradiation as initially measured breaks and after 24 h postirradiation incubation (37 degrees C) as non-rejoined breaks in normal human fibroblasts with different heavy ions, such as carbon, neon, silicon and iron, generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Science (NIRS). Chromatin breaks were measured as an excess number of fragments of prematurely condensed chromosomes using premature chromosome condensation (PCC). The results showed that the number of excess fragments per cell per Gy for initially measured chromatin breaks was dependent on LET in the range from 13.3 to 113.1 keV/mum but was not dependent on ion species. On the other hand, the number of non-rejoined chromatin breaks detected after 24 h postirradiation incubation was clearly dependent on both LET and ion species. No significant difference was observed in the cross section for initially measured breaks, but a statistically significant difference was observed in the cross section for non-rejoined breaks among carbon, neon, silicon and iron ions. This suggests that the LET-dependent structure in the biological effects is reflected in biological consequences of repair processes.

Why Older Adults Spend Time Sedentary and Break Their Sedentary Behavior: A Mixed-Methods Approach Using Life-Logging Equipment.

PubMed

Dontje, Manon L; Leask, Calum F; Harvey, Juliet; Skelton, Dawn A; Chastin, Sebastien F M

2018-04-01

Older adults are recommended to reduce their sedentary time to promote healthy ageing. To develop effective interventions identifying when, why, and how older adults are able to change their sitting habits is important. The aim of this mixed-method study was to improve our understanding of reasons for (breaking) sedentary behavior in older adults. Thirty older adults (74.0 [±5.3] years old, 73% women) were asked about their believed reasons for (breaking) sedentary behavior, and about their actual reasons when looking at a personal storyboard with objective records of activPAL monitor data and time-lapse camera pictures showing all their periods of sedentary time in a day. The most often mentioned believed reason for remaining sedentary was television/radio (mentioned by 48.3%), while eating/drinking was most often mentioned as actual reason (96.6%). Only 17.2% believed that food/tea preparation was a reason to break up sitting, while this was an actual reason for 82.8% of the study sample. Results of this study show that there is a discrepancy between believed and actual reasons for (breaking) sedentary behavior. These findings suggest developing interventions utilizing the actual reasons for breaking sedentary behavior to reduce sedentary time in older adults.

Mechanical circulator for elastic waves by using the nonreciprocity of flexible rotating rings

NASA Astrophysics Data System (ADS)

Beli, Danilo; Silva, Priscilla Brandão; Arruda, José Roberto de França

2018-01-01

Circulators have a wide range of applications in wave manipulation. They provide a nonreciprocal response by breaking the time-reversal symmetry. In the mechanical field, nonlinear isolators and ferromagnetic circulators can be used for this objective. However, they require high power and high volumes. Herein, a flexible rotating ring is used to break the time-reversal symmetry as a result of the combined effect of Coriolis acceleration and material damping. Complete asymmetry of oscillating and evanescent components of wavenumbers is achieved. The elastic ring produces a nonreciprocal response that is used to design a three port mechanical circulator. The rotational speed for maximum transmission in one port and isolation in the other one is determined using analytical equations. A spectral element formulation is used to compute the complex dispersion diagrams and the forced response. Waveguides that support longitudinal and flexural waves are investigated. In this case, the ring nonreciprocity is modulated by the waveguide reciprocal response and the transmission coefficients can be affected. The proposed device is compact, nonferromagnetic, and may open new directions for elastic wave manipulation.

Fermion-number violation in regularizations that preserve fermion-number symmetry

NASA Astrophysics Data System (ADS)

Golterman, Maarten; Shamir, Yigal

2003-01-01

There exist both continuum and lattice regularizations of gauge theories with fermions which preserve chiral U(1) invariance (“fermion number”). Such regularizations necessarily break gauge invariance but, in a covariant gauge, one recovers gauge invariance to all orders in perturbation theory by including suitable counterterms. At the nonperturbative level, an apparent conflict then arises between the chiral U(1) symmetry of the regularized theory and the existence of ’t Hooft vertices in the renormalized theory. The only possible resolution of the paradox is that the chiral U(1) symmetry is broken spontaneously in the enlarged Hilbert space of the covariantly gauge-fixed theory. The corresponding Goldstone pole is unphysical. The theory must therefore be defined by introducing a small fermion-mass term that breaks explicitly the chiral U(1) invariance and is sent to zero after the infinite-volume limit has been taken. Using this careful definition (and a lattice regularization) for the calculation of correlation functions in the one-instanton sector, we show that the ’t Hooft vertices are recovered as expected.

Neural Correlates of Coherence-Break Detection during Reading of Narratives

ERIC Educational Resources Information Center

Helder, Anne; van den Broek, Paul; Karlsson, Josefine; Van Leijenhorst, Linda

2017-01-01

This functional magnetic resonance imaging study examined the neural correlates of coherence-break detection during reading in the context of a contradiction paradigm. Young adults (N = 31, ages 19-27) read short narratives (half contained a break in coherence) that were presented sentence by sentence in a self-paced, slow event-related design.…

A comparison of G2 phase radiation-induced chromatid break kinetics using calyculin-PCC with those obtained using colcemid block.

PubMed

Bryant, Peter E; Mozdarani, Hossein

2007-09-01

To study the possible influence of cell-cycle delay on cells reaching mitosis during conventional radiation-induced chromatid break experiments using colcemid as a blocking agent, we have compared the chromatid break kinetics following a single dose of gamma rays (0.75 Gy) in metaphase CHO cells using calyculin-induced premature chromosome condensation (PCC), with those using colcemid block. Calyculin-induced PCC causes very rapid condensation of G2 cell chromosomes without the need for a cell to progress to mitosis, hence eliminating any effect of cell-cycle checkpoint on chromatid break frequency. We found that the kinetics of the exponential first-order decrease in chromatid breaks with time after irradiation was similar (not significantly different) between the two methods of chromosome condensation. However, use of the calyculin-PCC technique resulted in a slightly increased rate of disappearance of chromatid breaks and thus higher frequencies of breaks at 1.5 and 2.5 h following irradiation. We also report on the effect of the nucleoside analogue ara A on chromatid break kinetics using the two chromosome condensation techniques. Ara A treatment of cells abrogated the decrease in chromatid breaks with time, both using the calyculin-PCC and colcemid methods. We conclude that cell-cycle delay may be a factor determining the absolute frequency of chromatid breaks at various times following irradiation of cells in G2 phase but that the first-order disappearance of chromatid breaks with time and its abrogation by ara A are not significantly influenced by the G2 checkpoint.

Controlled breaks as a fatigue countermeasure on the flight deck

NASA Technical Reports Server (NTRS)

Neri, David F.; Oyung, Raymond L.; Colletti, Laura M.; Mallis, Melissa M.; Tam, Patricia Y.; Dinges, David F.

2002-01-01

BACKGROUND: A major challenge for flight crews is the need to maintain vigilance during long, highly automated nighttime flights. No system currently exists to assist in managing alertness, and countermeasure options are limited. Surveys reveal many pilots use breaks as an in-flight countermeasure, but there have been no controlled studies of their effectiveness. HYPOTHESIS: We hypothesized that brief, regular breaks could improve alertness and performance during an overnight flight. METHOD: A 6-h, uneventful, nighttime flight in a Boeing 747-400 flight simulator was flown by fourteen two-man crews. The 14 subjects in the treatment group received 5 short breaks spaced hourly during cruise; the 14 subjects in the control group received 1 break in the middle of cruise. Continuous EEG/EOG, subjective sleepiness, and psychomotor vigilance performance data were collected. RESULTS: During the latter part of the night, the treatment group showed significant reductions for 15 min post-break in slow eye movements, theta-band activity, and unintended sleep episodes compared with the control group. The treatment group reported significantly greater subjective alertness for up to 25 min post-break, with strongest effects near the time of the circadian trough. There was no evidence of objective vigilance performance improvement at 15-25 min post-break, with expected performance deterioration occurring due to elevated sleep drive and circadian time. CONCLUSIONS: The physiological and subjective data indicate the breaks reduced nighttime sleepiness for at least 15 min post-break and may have masked sleepiness for up to 25 min, suggesting the potential usefulness of short-duration breaks as an in-flight fatigue countermeasure.

Controlled breaks as a fatigue countermeasure on the flight deck.

PubMed

Neri, David F; Oyung, Raymond L; Colletti, Laura M; Mallis, Melissa M; Tam, Patricia Y; Dinges, David F

2002-07-01

A major challenge for flight crews is the need to maintain vigilance during long, highly automated nighttime flights. No system currently exists to assist in managing alertness, and countermeasure options are limited. Surveys reveal many pilots use breaks as an in-flight countermeasure, but there have been no controlled studies of their effectiveness. We hypothesized that brief, regular breaks could improve alertness and performance during an overnight flight. A 6-h, uneventful, nighttime flight in a Boeing 747-400 flight simulator was flown by fourteen two-man crews. The 14 subjects in the treatment group received 5 short breaks spaced hourly during cruise; the 14 subjects in the control group received 1 break in the middle of cruise. Continuous EEG/EOG, subjective sleepiness, and psychomotor vigilance performance data were collected. During the latter part of the night, the treatment group showed significant reductions for 15 min post-break in slow eye movements, theta-band activity, and unintended sleep episodes compared with the control group. The treatment group reported significantly greater subjective alertness for up to 25 min post-break, with strongest effects near the time of the circadian trough. There was no evidence of objective vigilance performance improvement at 15-25 min post-break, with expected performance deterioration occurring due to elevated sleep drive and circadian time. The physiological and subjective data indicate the breaks reduced nighttime sleepiness for at least 15 min post-break and may have masked sleepiness for up to 25 min, suggesting the potential usefulness of short-duration breaks as an in-flight fatigue countermeasure.

Repair of DNA Strand Breaks in a Minichromosome In Vivo: Kinetics, Modeling, and Effects of Inhibitors

PubMed Central

Kumala, Slawomir; Fujarewicz, Krzysztof; Jayaraju, Dheekollu; Rzeszowska-Wolny, Joanna; Hancock, Ronald

2013-01-01

To obtain an overall picture of the repair of DNA single and double strand breaks in a defined region of chromatin in vivo, we studied their repair in a ∼170 kb circular minichromosome whose length and topology are analogous to those of the closed loops in genomic chromatin. The rate of repair of single strand breaks in cells irradiated with γ photons was quantitated by determining the sensitivity of the minichromosome DNA to nuclease S1, and that of double strand breaks by assaying the reformation of supercoiled DNA using pulsed field electrophoresis. Reformation of supercoiled DNA, which requires that all single strand breaks have been repaired, was not slowed detectably by the inhibitors of poly(ADP-ribose) polymerase-1 NU1025 or 1,5-IQD. Repair of double strand breaks was slowed by 20–30% when homologous recombination was supressed by KU55933, caffeine, or siRNA-mediated depletion of Rad51 but was completely arrested by the inhibitors of nonhomologous end-joining wortmannin or NU7441, responses interpreted as reflecting competition between these repair pathways similar to that seen in genomic DNA. The reformation of supercoiled DNA was unaffected when topoisomerases I or II, whose participation in repair of strand breaks has been controversial, were inhibited by the catalytic inhibitors ICRF-193 or F11782. Modeling of the kinetics of repair provided rate constants and showed that repair of single strand breaks in minichromosome DNA proceeded independently of repair of double strand breaks. The simplicity of quantitating strand breaks in this minichromosome provides a usefull system for testing the efficiency of new inhibitors of their repair, and since the sequence and structural features of its DNA and its transcription pattern have been studied extensively it offers a good model for examining other aspects of DNA breakage and repair. PMID:23382828

Colour break in reverse bicolour daffodils is associated with the presence of Narcissus mosaic virus

PubMed Central

2011-01-01

Background Daffodils (Narcissus pseudonarcissus) are one of the world's most popular ornamentals. They also provide a scientific model for studying the carotenoid pigments responsible for their yellow and orange flower colours. In reverse bicolour daffodils, the yellow flower trumpet fades to white with age. The flowers of this type of daffodil are particularly prone to colour break whereby, upon opening, the yellow colour of the perianth is observed to be 'broken' into patches of white. This colour break symptom is characteristic of potyviral infections in other ornamentals such as tulips whose colour break is due to alterations in the presence of anthocyanins. However, reverse bicolour flowers displaying colour break show no other virus-like symptoms such as leaf mottling or plant stunting, leading some to argue that the carotenoid-based colour breaking in reverse bicolour flowers may not be caused by virus infection. Results Although potyviruses have been reported to cause colour break in other flower species, enzyme-linked-immunoassays with an antibody specific to the potyviral family showed that potyviruses were not responsible for the occurrence of colour break in reverse bicolour daffodils. Colour break in this type of daffodil was clearly associated with the presence of large quantities of rod-shaped viral particles of lengths 502-580 nm in tepals. Sap from flowers displaying colour break caused red necrotic lesions on Gomphrena globosa, suggesting the presence of potexvirus. Red necrotic lesions were not observed in this indicator plant when sap from reverse bicolour flowers not showing colour break was used. The reverse transcriptase polymerase reactions using degenerate primers to carla-, potex- and poty-viruses linked viral RNA with colour break and sequencing of the amplified products indicated that the potexvirus Narcissisus mosaic virus was the predominant virus associated with the occurrence of the colour break. Conclusions High viral counts were associated with the reverse bicolour daffodil flowers that were displaying colour break but otherwise showed no other symptoms of infection. Narcissus mosaic virus was the virus that was clearly linked to the carotenoid-based colour break. PMID:21854646

Defining time crystals via representation theory

NASA Astrophysics Data System (ADS)

Khemani, Vedika; von Keyserlingk, C. W.; Sondhi, S. L.

2017-09-01

Time crystals are proposed states of matter which spontaneously break time translation symmetry. There is no settled definition of such states. We offer a new definition which follows the traditional recipe for Wigner symmetries and order parameters. Supplementing our definition with a few plausible assumptions we find that a) systems with time-independent Hamiltonians should not exhibit time translation symmetry breaking while b) the recently studied π spin glass/Floquet time crystal can be viewed as breaking a global internal symmetry and as breaking time translation symmetry, as befits its two names.

Child personality facets and overreactive parenting as predictors of aggression and rule-breaking trajectories from childhood to adolescence.

PubMed

Becht, Andrik I; Prinzie, Peter; Deković, Maja; van den Akker, Alithe L; Shiner, Rebecca L

2016-05-01

This study examined trajectories of aggression and rule breaking during the transition from childhood to adolescence (ages 9-15), and determined whether these trajectories were predicted by lower order personality facets, overreactive parenting, and their interaction. At three time points separated by 2-year intervals, mothers and fathers reported on their children's aggression and rule breaking (N = 290, M age = 8.8 years at Time 1). At Time 1, parents reported on their children's personality traits and their own overreactivity. Growth mixture modeling identified three aggression trajectories (low decreasing, high decreasing, and high increasing) and two rule-breaking trajectories (low and high). Lower optimism and compliance and higher energy predicted trajectories for both aggression and rule breaking, whereas higher expressiveness and irritability and lower orderliness and perseverance were unique risk factors for increasing aggression into adolescence. Lower concentration was a unique risk factor for increasing rule breaking. Parental overreactivity predicted higher trajectories of aggression but not rule breaking. Only two Trait × Overreactivity interactions were found. Our results indicate that personality facets could differentiate children at risk for different developmental trajectories of aggression and rule breaking.

Effects of surface wave breaking on the oceanic boundary layer

NASA Astrophysics Data System (ADS)

He, Hailun; Chen, Dake

2011-04-01

Existing laboratory studies suggest that surface wave breaking may exert a significant impact on the formation and evolution of oceanic surface boundary layer, which plays an important role in the ocean-atmosphere coupled system. However, present climate models either neglect the effects of wave breaking or treat them implicitly through some crude parameterization. Here we use a one-dimensional ocean model (General Ocean Turbulence Model, GOTM) to investigate the effects of wave breaking on the oceanic boundary layer on diurnal to seasonal time scales. First a set of idealized experiments are carried out to demonstrate the basic physics and the necessity to include wave breaking. Then the model is applied to simulating observations at the northern North Sea and the Ocean Weather Station Papa, which shows that properly accounting for wave breaking effects can improve model performance and help it to successfully capture the observed upper ocean variability.

Regulating strain states by using the recovery potential of lunch breaks.

PubMed

Krajewski, Jarek; Wieland, Rainer; Sauerland, Martin

2010-04-01

The aim of the worksite study is to elucidate the strain reducing impact of different forms of spending lunch breaks. With the help of the so-called silent room cabin concept, it was possible to induce a lunch-break relaxation opportunity that provided visual and territorial privacy. To evaluate the proposed effects, 14 call center agents were assigned to either 20 min progressive muscle relaxation (PMR) or small-talk (ST) break groups. We analyzed the data in a controlled trial for a period of 6 months (every 2 months four measurements a day at 12:00, 13:00, 16:00, 20:00) using independent observer and self-report ratings of emotional, mental, motivational, and physical strain. Results indicated that only the PMR break reduced postlunchtime and afternoon strain. Although further intervention research is required, our results suggest that PMR lunch break may sustainable reduce strain states in real worksite settings. Copyright 2010 APA, all rights reserved.

Upper mantle temperature and the onset of extension and break-up in Afar, Africa

NASA Astrophysics Data System (ADS)

Armitage, John J.; Ferguson, David J.; Goes, Saskia; Hammond, James O. S.; Calais, Eric; Rychert, Catherine A.; Harmon, Nicholas

2015-05-01

It is debated to what extent mantle plumes play a role in continental rifting and eventual break-up. Afar lies at the northern end of the largest and most active present-day continental rift, where the East African Rift forms a triple junction with the Red Sea and Gulf of Aden rifts. It has a history of plume activity yet recent studies have reached conflicting conclusions on whether a plume still contributes to current Afar tectonics. A geochemical study concluded that Afar is a mature hot rift with 80 km thick lithosphere, while seismic data have been interpreted to reflect the structure of a young, oceanic rift basin above mantle of normal temperature. We develop a self-consistent forward model of mantle flow that incorporates melt generation and retention to test whether predictions of melt chemistry, melt volume and lithosphere-asthenosphere seismic structure can be reconciled with observations. The rare-earth element composition of mafic samples at the Erta Ale, Dabbahu and Asal magmatic segments can be used as both a thermometer and chronometer of the rifting process. Low seismic velocities require a lithosphere thinned to 50 km or less. A strong positive impedance contrast at 50 to 70 km below the rift seems linked to the melt zone, but is not reproduced by isotropic seismic velocity alone. Combined, the simplest interpretation is that mantle temperature below Afar is still elevated at 1450 °C, rifting started around 22-23 Ma, and the lithosphere has thinned from 100 to 50 km to allow significant decompressional melting.

Phase transitions in a system of hard Y-shaped particles on the triangular lattice

NASA Astrophysics Data System (ADS)

Mandal, Dipanjan; Nath, Trisha; Rajesh, R.

2018-03-01

We study the different phases and the phase transitions in a system of Y-shaped particles, examples of which include immunoglobulin-G and trinaphthylene molecules, on a triangular lattice interacting exclusively through excluded volume interactions. Each particle consists of a central site and three of its six nearest neighbors chosen alternately, such that there are two types of particles which are mirror images of each other. We study the equilibrium properties of the system using grand canonical Monte Carlo simulations that implement an algorithm with cluster moves that is able to equilibrate the system at densities close to full packing. We show that, with increasing density, the system undergoes two entropy-driven phase transitions with two broken-symmetry phases. At low densities, the system is in a disordered phase. As intermediate phases, there is a solidlike sublattice phase in which one type of particle is preferred over the other and the particles preferentially occupy one of four sublattices, thus breaking both particle symmetry as well as translational invariance. At even higher densities, the phase is a columnar phase, where the particle symmetry is restored, and the particles preferentially occupy even or odd rows along one of the three directions. This phase has translational order in only one direction, and breaks rotational invariance. From finite-size scaling, we demonstrate that both the transitions are first order in nature. We also show that the simpler system with only one type of particle undergoes a single discontinuous phase transition from a disordered phase to a solidlike sublattice phase with an increasing density of particles.

Non-linear hydrodynamic instability and turbulence in eccentric astrophysical discs with vertical structure

NASA Astrophysics Data System (ADS)

Wienkers, A. F.; Ogilvie, G. I.

2018-07-01

Non-linear evolution of the parametric instability of inertial waves inherent to eccentric discs is studied by way of a new local numerical model. Mode coupling of tidal deformation with the disc eccentricity is known to produce exponentially growing eccentricities at certain mean-motion resonances. However, the details of an efficient saturation mechanism balancing this growth still are not fully understood. This paper develops a local numerical model for an eccentric quasi-axisymmetric shearing box which generalizes the often-used Cartesian shearing box model. The numerical method is an overall second-order well-balanced finite volume method which maintains the stratified and oscillatory steady-state solution by construction. This implementation is employed to study the non-linear outcome of the parametric instability in eccentric discs with vertical structure. Stratification is found to constrain the perturbation energy near the mid-plane and localize the effective region of inertial wave breaking that sources turbulence. A saturated marginally sonic turbulent state results from the non-linear breaking of inertial waves and is subsequently unstable to large-scale axisymmetric zonal flow structures. This resulting limit-cycle behaviour reduces access to the eccentric energy source and prevents substantial transport of angular momentum radially through the disc. Still, the saturation of this parametric instability of inertial waves is shown to damp eccentricity on a time-scale of a thousand orbital periods. It may thus be a promising mechanism for intermittently regaining balance with the exponential growth of eccentricity from the eccentric Lindblad resonances and may also help explain the occurrence of 'bursty' dynamics such as the superhump phenomenon.

Theoretical investigations into the influence of the position of a breaking line on the tensile failure of flat, round, bevel-edged tablets using finite element methodology (FEM) and its practical relevance for industrial tablet strength testing.

PubMed

Podczeck, Fridrun; Newton, J Michael; Fromme, Paul

2014-12-30

Flat, round tablets may have a breaking ("score") line. Pharmacopoeial tablet breaking load tests are diametral in their design, and industrially used breaking load testers often have automatic tablet feeding systems, which position the tablets between the loading platens of the machine with the breaking lines in random orientation to the applied load. The aim of this work was to ascertain the influence of the position of the breaking line in a diametral compression test using finite element methodology (FEM) and to compare the theoretical results with practical findings using commercially produced bevel-edged, scored tablets. Breaking line test positions at an angle of 0°, 22.5°, 45°, 67.5° and 90° relative to the loading plane were studied. FEM results obtained for fully elastic and elasto-plastic tablets were fairly similar, but they highlighted large differences in stress distributions depending on the position of the breaking line. The stress values at failure were predicted to be similar for tablets tested at an angle of 45° or above, whereas at lower test angles the predicted breaking loads were up to three times larger. The stress distributions suggested that not all breaking line angles would result in clean tensile failure. Practical results, however, did not confirm the differences in the predicted breaking loads, but they confirmed differences in the way tablets broke. The results suggest that it is not advisable to convert breaking loads obtained on scored tablets into tablet tensile strength values, and comparisons between different tablets or batches should carefully consider the orientation of the breaking line with respect to the loading plane, as the failure mechanisms appear to vary. Copyright © 2014 Elsevier B.V. All rights reserved.

Sea Ice

NASA Technical Reports Server (NTRS)

Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

2013-01-01

During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

Light and compressed gluinos at the LHC via string theory.

PubMed

AbdusSalam, S S

2017-01-01

In this article, we show that making global fits of string theory model parameters to data is an interesting mechanism for probing, mapping and forecasting connections of the theory to real world physics. We considered a large volume scenario (LVS) with D3-brane matter fields and supersymmetry breaking. A global fit of the parameters to low-energy data shows that the set of LVS models are associated with light gluinos which are quasi-degenerate with the neutralinos and charginos they can promptly decay into, and thus they are possibly hidden to current LHC gluino search strategies.

Metabolism: The Physiological Power-Generating Process: A History of Methods to Test Human Beings' \\"Vital Capacity\\" [Retrospectroscope].

PubMed

Johnston, Richard; Valentinuzzi, Max E

2016-01-01

A previous "Retrospectroscope" note, published early in 2014, dealt with spirometry: it described many apparatuses used to measure the volume of inhaled and exhaled air that results from breathing [1]. Such machines, when adequately modified, are also able to measure the rate at which work is produced (specifically by an animal or a human being). Metabolism in that sense is the term used by physiologists and physicians, a word that in Greek, metabolismos, means "change" or "overthrow," in the sense of breaking down material, as in burning some stuff.

Validation of whitecap fraction and breaking wave parameters from WAVEWATCH-III using in situ and remote-sensing data

NASA Astrophysics Data System (ADS)

Leckler, F.; Hanafin, J. A.; Ardhuin, F.; Filipot, J.; Anguelova, M. D.; Moat, B. I.; Yelland, M.; Prytherch, J.

2012-12-01

Whitecaps are the main sink of wave energy. Although the exact processes are still unknown, it is clear that they play a significant role in momentum exchange between atmosphere and ocean, and also influence gas and aerosol exchange. Recently, modeling of whitecap properties was implemented in the spectral wave model WAVEWATCH-III ®. This modeling takes place in the context of the Oceanflux-Greenhouse Gas project, to provide a climatology of breaking waves for gas transfer studies. We present here a validation study for two different wave breaking parameterizations implemented in the spectral wave model WAVEWATCH-III ®. The model parameterizations use different approaches related to the steepness of the carrying waves to estimate breaking wave probabilities. That of Ardhuin et al. (2010) is based on the hypothesis that breaking probabilities become significant when the saturation spectrum exceeds a threshold, and includes a modification to allow for greater breaking in the mean wave direction, to agree with observations. It also includes suppression of shorter waves by longer breaking waves. In the second, (Filipot and Ardhuin, 2012) breaking probabilities are defined at different scales using wave steepness, then the breaking wave height distribution is integrated over all scales. We also propose an adaptation of the latter to make it self-consistent. The breaking probabilities parameterized by Filipot and Ardhuin (2012) are much larger for dominant waves than those from the other parameterization, and show better agreement with modeled statistics of breaking crest lengths measured during the FAIRS experiment. This stronger breaking also has an impact on the shorter waves due to the parameterization of short wave damping associated with large breakers, and results in a different distribution of the breaking crest lengths. Converted to whitecap coverage using Reul and Chapron (2003), both parameterizations agree reasonably well with commonly-used empirical fits of whitecap coverage against wind speed (Monahan and Woolf, 1989) and with the global whitecap coverage of Anguelova and Webster (2006), derived from space-borne radiometry. This is mainly due to the fact that the breaking of larger waves in the parametrization by Filipot and Ardhuin (2012) is compensated for by the intense breaking of smaller waves in that of Ardhuin et al. (2010). Comparison with in situ data collected during research ship cruises in the North and South Atlantic (SEASAW, DOGEE and WAGES), and the Norwegian Sea (HiWASE) between 2006 and 2011 also shows good agreement. However, as large scale breakers produce a thicker foam layer, modeled mean foam thickness clearly depends on the scale of the breakers. Foam thickness is thus a more interesting parameter for calibrating and validating breaking wave parameterizations, as the differences in scale can be determined. With this in mind, we present the initial results of validation using an estimation of mean foam thickness using multiple radiometric bands from satellites SMOS and AMSR-E.

Crustal structure of Wrangellia and adjacent terranes inferred from geophysical studies along a transect through the northern Talkeetna Mountains

USGS Publications Warehouse

Glen, J.M.G.; Schmidt, J.; Pellerin, L.; McPhee, D.K.; O'Neill, J. M.

2007-01-01

Recent investigations of the Talkeetna Mountains in south-central Alaska were undertaken to study the region's framework geophysics and to reinterpret structures and crustal composition. Potential field (gravity and magnetic) and magnetotelluric (MT) data were collected along northwest-trending profiles as part of the U.S. Geological Survey's Talkeetna Mountains transect project. The Talkeetna Mountains transect area comprises eight 1:63,360 quadrangles (???9500 km2) in the Healy and Talkeetna Mountains 1?? ?? 3?? sheets that span four major lithostratigraphic terranes (Glen et al., this volume) including the Wrangellia and Peninsular terranes and two Mesozoic overlap assemblages inboard (northwest) of Wrangellia. These data were used here to develop 21/2-dimensional models for the three profiles. Modeling results reveal prominent gravity, magnetic, and MT gradients (???3.25 mGal/ km, ???100nT/km, ???300 ohm-m/km) corresponding to the Talkeetna Suture Zone-a first-order crustal discontinuity in the deep crust that juxtaposes rocks with strongly contrasting rock properties. This discontinuity corresponds with the suture between relatively dense magnetic crust of Wrangellia (likely of oceanic composition) and relatively less dense transitional crust underlying Jurassic to Cretaceous flysch basins developed between Wrangellia and North America. Some area of the oceanic crust beneath Wrangellia may also have been underplated by mafic material during early to mid-Tertiary volcanism. The prominent crustal break underlies the Fog Lakes basin approximately where theTalkeetna thrust faultwaspreviouslymappedas a surface feature. Potential fieldand MT models, however, indicate that the Talkeetna Suture Zone crustal break along the transect is a deep (2-8 km), steeply west-dipping structure-not a shallow east-dipping Alpine nappe-like thrust. Indeed, most of the crustal breaks in the area appear to be steep in the geophysical data, which is consistent with regional geologic mapping that indicates that most of the faults are steep normal, reverse, strike-slip, or oblique-slip faults. Mapping further indicates that many of these features, which likely formed during Jurassic and Cretaceous time, such as the Talkeetna Suture Zone have reactivated inTertiary time (O'Neill et al., 2005). Copyright ?? 2007 The Geological Society of America.

Driving pressure and mechanical power: new targets for VILI prevention.

PubMed

Tonetti, Tommaso; Vasques, Francesco; Rapetti, Francesca; Maiolo, Giorgia; Collino, Francesca; Romitti, Federica; Camporota, Luigi; Cressoni, Massimo; Cadringher, Paolo; Quintel, Michael; Gattinoni, Luciano

2017-07-01

Several factors have been recognized as possible triggers of ventilator-induced lung injury (VILI). The first is pressure (thus the 'barotrauma'), then the volume (hence the 'volutrauma'), finally the cyclic opening-closing of the lung units ('atelectrauma'). Less attention has been paid to the respiratory rate and the flow, although both theoretical considerations and experimental evidence attribute them a significant role in the generation of VILI. The initial injury to the lung parenchyma is necessarily mechanical and it could manifest as an unphysiological distortion of the extracellular matrix and/or as micro-fractures in the hyaluronan, likely the most fragile polymer embedded in the matrix. The order of magnitude of the energy required to break a molecular bond between the hyaluronan and the associated protein is 1.12×10 -16 Joules (J), 70-90% higher than the average energy delivered by a single breath of 1L assuming a lung elastance of 10 cmH 2 O/L (0.5 J). With a normal statistical distribution of the bond strength some polymers will be exposed each cycle to an energy large enough to rupture. Both the extracellular matrix distortion and the polymer fractures lead to inflammatory increase of capillary permeability with edema if a pulmonary blood flow is sufficient. The mediation analysis of higher vs. lower tidal volume and PEEP studies suggests that the driving pressure, more than tidal volume, is the best predictor of VILI, as inferred by increased mortality. This is not surprising, as both tidal volume and respiratory system elastance (resulting in driving pressure) may independently contribute to the mortality. For the same elastance driving pressure is a predictor similar to plateau pressure or tidal volume. Driving pressure is one of the components of the mechanical power, which also includes respiratory rate, flow and PEEP. Finding the threshold for mechanical power would greatly simplify assessment and prevention of VILI.

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men's basketball games.

PubMed

Conte, D; Favero, T G; Niederhausen, M; Capranica, L; Tessitore, A

2017-06-01

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1 st -division (elite) and fifteen 3 rd -division (sub-elite) Italian men's championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p<0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions.

Keeping It Real: Exploring an Interdisciplinary Breaking Bad News Role-Play as an Integrative Learning Opportunity

ERIC Educational Resources Information Center

Sweeney, Catherine; O'Sullivan, Eleanor; McCarthy, Marian

2015-01-01

Palliative care is a complex area of healthcare best delivered by an interdisciplinary team approach. Breaking bad news is an inherent part of caring for people with life-limiting conditions. This study aims to explore an interdisciplinary breaking bad news role-play in a palliative care module. Participants were undergraduate medical and nursing…

Making Infrastructure Visible: A Case Study of Home Networking

ERIC Educational Resources Information Center

Chetty, Marshini

2011-01-01

Technological infrastructure is often taken for granted in our day to day lives until it breaks down, usually because it invisibly supports tasks otherwise. Previous work in HCI has focused on how people react and deal with breaks in infrastructure as well as how to help people to fix or exploit these breaks. However, few have sought to understand…

"I just wanted to get away": An analysis of spring breakers' travel motivations

Treesearch

Nuno F. Ribeiro; Paul E. Durrenberger; Careen M. Yarnal; Garry E. Chick

2010-01-01

Scholarly research on Spring Break has grown substantially and has often associated spring breakers' motivations with a number of risky behaviors. Recent research, however, has challenged these assumptions. The purpose of this study was to examine spring breakers' motivations for going on Spring Break. Unlike the media portrayal of Spring Break as a time of...

Break-even zones for cable yarding by log size

Treesearch

Chris B. LeDoux

1984-01-01

The use of cable logging to extract small pieces of residue wood may result in low rates of production and a high cost per unit of wood produced. However, the logging manager can improve yarding productivity and break-even in cable residue removal operations by using the proper planning techniques. In this study, break-even zones for specific young-growth stands were...

Numerical simulation study on the optimization design of the crown shape of PDC drill bit.

PubMed

Ju, Pei; Wang, Zhenquan; Zhai, Yinghu; Su, Dongyu; Zhang, Yunchi; Cao, Zhaohui

The design of bit crown is an important part of polycrystalline diamond compact (PDC) bit design, although predecessors have done a lot of researches on the design principles of PDC bit crown, the study of the law about rock-breaking energy consumption according to different bit crown shape is not very systematic, and the mathematical model of design is over-simplified. In order to analyze the relation between rock-breaking energy consumption and bit crown shape quantificationally, the paper puts forward an idea to take "per revolution-specific rock-breaking work" as objective function, and analyzes the relationship between rock properties, inner cone angle, outer cone arc radius, and per revolution-specific rock-breaking work by means of explicit dynamic finite element method. Results show that the change law between per revolution-specific rock-breaking work and the radius of gyration is similar for rocks with different properties, it is beneficial to decrease rock-breaking energy consumption by decreasing inner cone angle or outer cone arc radius. Of course, we should also consider hydraulic structure and processing technology in the optimization design of PDC bit crown.

Breaking bad news of cancer diagnosis - Perception of the cancer patients in a rural community in Malaysia.

PubMed

Bain, Mathew Gabriel; Lian, Cheah Whye; Thon, Chang Ching

2014-04-01

Breaking of bad news is an important component in the management of cancer patients. This study aimed to assess the perceptions of breaking bad news of cancer diagnosis. It was a cross-sectional study using Breaking Bad News Assessment Schedule (BAS) questionnaire on cancer patients in Serian district. Using snowballing sampling method, a total of 134 patients were interviewed face-to-face after the consent was obtained from each of the respondents. Data was entered and analyzed using SPSS version 19.0. Majority were comfortable with the current method of breaking bad news. The main aspects found to be the areas of concern were the importance of the usage of body language, management of time and identifying patients' key area of concerns. There were significant difference between sex and "information giving" (P = 0.028) and "general consideration" (P = 0.016) and also between "the age and setting the scene" (P = 0.042). Significant difference was also found between the types of cancer and "the setting of scene" (P = 0.018), "breaking bad news technique" (P = 0.010), "eliciting concerns" (P = 0.003) and "information giving" (P = 0.004). Good and effective communication skill of breaking bad news is vital in the management of cancer patients. As the incidence of new cases of cancer increase every year, breaking of bad news has become a pertinent to the medical professionals' role. Specific aspects of communication skills based on local characteristics should be more emphasized in the formulation of training for doctors.

Homologous Recombination Repair Signaling in Chemical Carcinogenesis: Prolonged Particulate Hexavalent Chromium Exposure Suppresses the Rad51 Response in Human Lung Cells

PubMed Central

Qin, Qin; Xie, Hong; Wise, Sandra S.; Browning, Cynthia L.; Thompson, Kelsey N.; Holmes, Amie L.; Wise, John Pierce

2014-01-01

The aim of this study was to focus on hexavalent chromium, [Cr(VI)], a chemical carcinogen and major public health concern, and consider its ability to impact DNA double strand break repair. We further focused on particulate Cr(VI), because it is the more potent carcinogenic form of Cr(VI). DNA double strand break repair serves to protect cells against the detrimental effects of DNA double strand breaks. For particulate Cr(VI), data show DNA double strand break repair must be overcome for neoplastic transformation to occur. Acute Cr(VI) exposures reveal a robust DNA double strand break repair response, however, longer exposures have not been considered. Using the comet assay, we found longer exposures to particulate zinc chromate induced concentration-dependent increases in DNA double strand breaks indicating breaks were occurring throughout the exposure time. Acute (24 h) exposure induced DNA double strand break repair signaling by inducing Mre11 foci formation, ATM phosphorylation and phosphorylated ATM foci formation, Rad51 protein levels and Rad51 foci formation. However, longer exposures reduced the Rad51 response. These data indicate a major chemical carcinogen can simultaneously induce DNA double strand breaks and alter their repair and describe a new and important aspect of the carcinogenic mechanism for Cr(VI). PMID:25173789

Wave Breaking Dissipation in Fetch-Limited Seas

NASA Astrophysics Data System (ADS)

Schwendeman, M.; Thomson, J. M.; Gemmrich, J.

2012-12-01

Breaking waves on the ocean surface control wave growth and enhance air-sea interaction, yet field measurements of breaking are limited. A promising technique for field measurements of wave breaking uses the breaking crest length distribution Λ(c), introduced by Phillips (1985). However, calculating dynamic quantities from Λ(c) requires knowledge of the breaking strength parameter, b. Estimates of a b have varied over many orders of magnitude, and recent studies have attempted to model b in terms of sea state, such as wave steepness or saturation. We present comprehensive observations of breaking in fetch-limited conditions from Juan de Fuca Strait, WA. The wave evolution along fetch is explained by an observed energy budget using the radiative transfer equation (RTE), and the evolution is consistent with existing empirical fetch laws. Estimates of Λ(c) increase along fetch and are consistent with directly measured breaking rates. Using novel in situ measures of dissipation, as well as a residual term from the RTE budget, we obtain robust estimates of the wave breaking strength b. Results suggest that b decreases with wave steepness and saturation, in contrast with recent laboratory results (Drazen et al, 2008). This trend is discussed in terms of the fetch evolution and associated broadening of the equilibrium range in the wave spectra.Map of drifter tracks colored by wave height for two days in Juan de Fuca Strait, WA.

POSTFUNDOPLICATION DYSPHAGIA CAUSES SIMILAR WATER INGESTION DYNAMICS AS ACHALASIA.

PubMed

Dantas, Roberto Oliveira; Santos, Carla Manfredi; Cassiani, Rachel Aguiar; Alves, Leda Maria Tavares; Nascimento, Weslania Viviane

2016-01-01

- After surgical treatment of gastroesophageal reflux disease dysphagia is a symptom in the majority of patients, with decrease in intensity over time. However, some patients may have persistent dysphagia. - The objective of this investigation was to evaluate the dynamics of water ingestion in patients with postfundoplication dysphagia compared with patients with dysphagia caused by achalasia, idiopathic or consequent to Chagas' disease, and controls. - Thirty-three patients with postfundoplication dysphagia, assessed more than one year after surgery, together with 50 patients with Chagas' disease, 27 patients with idiopathic achalasia and 88 controls were all evaluated by the water swallow test. They drunk, in triplicate, 50 mL of water without breaks while being precisely timed and the number of swallows counted. Also measured was: (a) inter-swallows interval - the time to complete the task, divided by the number of swallows during the task; (b) swallowing flow - volume drunk divided by the time taken; (c) volume of each swallow - volume drunk divided by the number of swallows. - Patients with postfundoplication dysphagia, Chagas' disease and idiopathic achalasia took longer to ingest all the volume, had an increased number of swallows, an increase in interval between swallows, a decrease in swallowing flow and a decrease in water volume of each swallow compared with the controls. There was no difference between the three groups of patients. There was no correlation between postfundoplication time and the results. - It was concluded that patients with postfundoplication dysphagia have similar water ingestion dynamics as patients with achalasia.

SANSMIC Validation.

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

Weber, Paula D.; Rudeen, David Keith; Lord, David L.

2014-08-01

SANSMIC is solution mining software that was developed and utilized by SNL in its role as geotechnical advisor to the US DOE SPR for planning purposes. Three SANSMIC leach modes - withdrawal, direct, and reverse leach - have been revalidated with multiple test cases for each mode. The withdrawal mode was validated using high quality data from recent leach activity while the direct and reverse modes utilized data from historical cavern completion reports. Withdrawal results compared very well with observed data, including the location and size of shelves due to string breaks with relative leached volume differences ranging from 6more » - 10% and relative radius differences from 1.5 - 3%. Profile comparisons for the direct mode were very good with relative leached volume differences ranging from 6 - 12% and relative radius differences from 5 - 7%. First, second, and third reverse configurations were simulated in order to validate SANSMIC over a range of relative hanging string and OBI locations. The first-reverse was simulated reasonably well with relative leached volume differences ranging from 1 - 9% and relative radius differences from 5 - 12%. The second-reverse mode showed the largest discrepancies in leach profile. Leached volume differences ranged from 8 - 12% and relative radius differences from 1 - 10%. In the third-reverse, relative leached volume differences ranged from 10 - 13% and relative radius differences were %7E4 %. Comparisons to historical reports were quite good, indicating that SANSMIC is essentially the same as documented and validated in the early 1980's.« less

Role of naturally occurring gas hydrates in sediment transport

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

McIver, R.D.

1982-06-01

Naturally occurring gas hydrates have the potential to store enormous volumes of both gas and water in semi-solid form in ocean-bottom sediments and then to release that gas and water when the hydrate's equilibrium condition are disturbed. Therefore, hydrates provide a potential mechanism for transporting large volumes of sediments. Under the combined low bottom-water temperatures and moderate hydrostatic pressures that exist over most of the continental slopes and all of the continental rises and abyssal plains, hydrocarbon gases at or near saturation in the interstitial waters of the near-bottom sediments will form hydrates. The gas can either be autochthonous, microbiallymore » produced gas, or allochthonous, catagenic gas from deeper sediments. Equilibrium conditions that stabilize hydrated sediments may be disturbed, for example, by continued sedimentation or by lowering of sea level. In either case, some of the solid gas-water matrix decomposes. Released gas and water volume exceeds the volume occupied by the hydrate, so the internal pressure rises - drastically if large volumes of hydrate are decomposed. Part of the once rigid sediment is converted to a gas- and water-rich, relatively low density mud. When the internal pressure, due to the presence of the compressed gas or to buoyancy, is sufficiently high, the overlying sediment may be lifted and/or breached, and the less dense, gas-cut mud may break through. Such hydrate-related phenomena can cause mud diapirs, mud volcanos, mud slides, or turbidite flows, depending on sediment configuration and bottom topography. 4 figures.« less

Breaking bad news and personality assessment.

PubMed

Rudnick, A; Ezra, Y; Melamed, E

2000-09-01

Breaking bad news to seriously ill patients is an especially difficult and important part of patient education and counseling. Guidelines for breaking bad news have been previously presented, but this is the first report to address the personality of the patient in deciding how to break had news. A case study of a patient diagnosed with amyotrophic lateral sclerosis is presented. A psychiatric consultation assisted in assessing the patient's personality and thus preparing the medical staff for breaking the bad news to him. The patient was assessed as having an obsessive-compulsive personality, and consequently the staff was instructed to concentrate on facts and not on feelings when breaking the bad news to him. The patient coped adaptively with this procedure, as did the staff. This case report illustrates that personality assessment may be of benefit in breaking bad news to seriously ill patients. It remains to be seen whether this procedure can be successfully generalized to other patients and settings as well as to other domains of patient education and counseling, and if so--whether this will also prove to be cost-effective.

Effect of winter school breaks on influenza-like illness, Argentina, 2005-2008.

PubMed

Garza, Roberto C; Basurto-Dávila, Ricardo; Ortega-Sanchez, Ismael R; Carlino, Luis Oreste; Meltzer, Martin I; Albalak, Rachel; Balbuena, Karina; Orellano, Pablo; Widdowson, Marc-Alain; Averhoff, Francisco

2013-06-01

School closures are used to reduce seasonal and pandemic influenza transmission, yet evidence of their effectiveness is sparse. In Argentina, annual winter school breaks occur during the influenza season, providing an opportunity to study this intervention. We used 2005-2008 national weekly surveillance data of visits to a health care provider for influenza-like illness (ILI) from all provinces. Using Serfling-specified Poisson regressions and population-based census denominators, we developed incidence rate ratios (IRRs) for the 3 weeks before, 2 weeks during, and 3 weeks after the break. For persons 5-64 years of age, IRRs were <1 for at least 1 week after the break. Observed rates returned to expected by the third week after the break; overall decrease among persons of all ages was 14%. The largest decrease was among children 5-14 years of age during the week after the break (37% lower IRR). Among adults, effects were weaker and delayed. Two-week winter school breaks significantly decreased visits to a health care provider for ILI among school-aged children and nonelderly adults.

Effect of Winter School Breaks on Influenza-like Illness, Argentina, 2005–2008

PubMed Central

Basurto-Dávila, Ricardo; Ortega-Sanchez, Ismael R.; Carlino, Luis Oreste; Meltzer, Martin I.; Albalak, Rachel; Balbuena, Karina; Orellano, Pablo; Widdowson, Marc-Alain; Averhoff, Francisco

2013-01-01

School closures are used to reduce seasonal and pandemic influenza transmission, yet evidence of their effectiveness is sparse. In Argentina, annual winter school breaks occur during the influenza season, providing an opportunity to study this intervention. We used 2005–2008 national weekly surveillance data of visits to a health care provider for influenza-like illness (ILI) from all provinces. Using Serfling-specified Poisson regressions and population-based census denominators, we developed incidence rate ratios (IRRs) for the 3 weeks before, 2 weeks during, and 3 weeks after the break. For persons 5–64 years of age, IRRs were <1 for at least 1 week after the break. Observed rates returned to expected by the third week after the break; overall decrease among persons of all ages was 14%. The largest decrease was among children 5–14 years of age during the week after the break (37% lower IRR). Among adults, effects were weaker and delayed. Two-week winter school breaks significantly decreased visits to a health care provider for ILI among school-aged children and nonelderly adults. PMID:23735682

Acoustical Studies of L-leucine and L-asparagine in aqueous electrolyte through thermal expansion coefficient

NASA Astrophysics Data System (ADS)

Jajodia, S.; Chimankar, O. P.; Kalambe, A.; Goswami, S. G.

2012-12-01

Amino acids are the building blocks of the proteins; their study provides important information, about the behaviour of larger biomolecules such as proteins. The properties of proteins such as their structure, solubility, denaturation, etc. are greatly influenced by electrolytes. Ultrasonic velocity and density values have been used for evaluation of thermal expansion coefficient and adiabatic compressibility for ternary systems (amino acid/salt + water) namely L-leucine / L-asparagine each in 1.5 M aqueous solution of NaCl used as solvent for various concentrations and at different temperatures (298.15K - 323.15K). Present paper reports the variation of various thermoacoustical parameters such as Moelwyn-Hughes parameter (C1), Beyer's non-linearity parameter (B/A), internal pressure (Pi), fractional free volume (f), available volume (Va), repulsive exponent (n), molecular constant (r), van der Waals' constant (b), Debye temperatue (θD), etc. have been computed from the thermal expansion coefficient with the change of concentration and temperature. The variations of all these parameters have been interpreted in terms of various intermolecular interactions such as strong, weak, charge transfer, complex formation, hydrogen bonding interaction. The structure making and breaking properties of the interacting components existing in proposed ternary systems. It shows the associating and dissociating tendency of the molecules of solute in solvent.The hetromolecular interactions are present in both the ternary systems.

Daily Variations in Spring Break Alcohol and Sexual Behaviors Based on Intentions, Perceived Norms, and Daily Trip Context

PubMed Central

Patrick, Megan E.; Lee, Christine M.

2012-01-01

Objective: Given the known risks of alcohol use and sexual behavior for college students on Spring Break, this study was designed to document the behaviors and correlates associated with being on a Spring Break trip on a given day (controlling for average time on a trip). Method: Participants were undergraduate students (n = 261; 55% women) who reported that they planned to go on a Spring Break trip. Web-based survey responses before and after Spring Break documented perceived norms, intentions, and actual behavior on each of the 10 days of Spring Break. Results: Students who went on longer trips, who previously engaged in more heavy episodic drinking, or who had greater pre–Spring Break intentions to drink reported greater alcohol use during Spring Break. Similarly, students with greater pre–Spring Break intentions to have sex, greater perceived norms for sex, or more previoussexual partners had greater odds of having sex. On days students were on trips, they had a greater likelihood of having sex, drinking to higher estimated blood alcohol concentrations, consuming more drinks, and reporting perceived drunkenness than on nontrip days, especially if they had intentions to have sex and drink alcohol (and, for models predicting sexual behavior and drunkenness, had greater perceived norms for sex and drinking). Conclusions: Students who went on Spring Break trips engaged in more risk behaviors. In addition, the context of being on a trip on a given day was associated with increased risk, especially if they had stronger intentions and, in some cases, higher perceived norms. Further research is needed to describe the contexts of Spring Break trips and how to intervene effectively. PMID:22630797

Employee perception of breastfeeding-friendly support and benefits of breastfeeding as a predictor of intention to use breast-pumping breaks after returning to work among employed mothers.

PubMed

Tsai, Su-Ying

2014-01-01

Although increasing numbers of large companies are complying with demands for a breastfeeding-friendly workplace by providing lactation rooms and breast-pumping breaks, the effectiveness for intention to use breast-pumping breaks to express breast milk among employed mothers is uncertain. To explore the impact of employees' perceived breastfeeding support from the workplace and the benefits of breastfeeding on a woman's intention to use breast-pumping breaks after returning to work, we conducted a survey at a female labor-intensive electronics manufacturer in Taiwan. A structured questionnaire survey was administered to 715 working mothers employed in an electronics manufacturing plant in Tainan Science Park in Southern Taiwan. Questionnaire content included female employee demographics, employment characteristics, and breastfeeding behavior after returning to work, as well as employees' perception of breastfeeding-friendly support and awareness of the benefits of breastfeeding when raising their most recently born child. Higher education (odds ratio [OR] 2.33), non-clean room worksite (OR 1.51), awareness of breast-pumping breaks (OR 4.70), encouragement by colleagues to use breast-pumping breaks (OR 1.76), and greater awareness of the benefits of breastfeeding (OR 1.08) were significant predictors of the use of breast-pumping breaks after returning to work, whereas the perception of inefficiency when using breast-pumping breaks reduced an employed mother's intention to use breast-pumping breaks (OR 0.55). This study finds an association between an appreciation of the benefits provided by the employer and the likelihood of increased usage of breastfeeding breaks. Workplaces and employers can help employed mothers to understand the benefits of breastfeeding, which may increase the intention of the mother to take breast-pumping breaks after returning to work.

Breaking Gravity Waves Over Large-Scale Topography

NASA Astrophysics Data System (ADS)

Doyle, J. D.; Shapiro, M. A.

2002-12-01

The importance of mountain waves is underscored by the numerous studies that document the impact on the atmospheric momentum balance, turbulence generation, and the creation of severe downslope winds. As stably stratified air is forced to rise over topography, large amplitude internal gravity waves may be generated that propagate vertically, amplify and breakdown in the upper troposphere and lower stratosphere. Many of the numerical studies reported on in the literature have used two- and three-dimensional models with simple, idealized initial states to examine gravity wave breaking. In spite of the extensive previous work, many questions remain regarding gravity wave breaking in the real atmosphere. Outstanding issues that are potentially important include: turbulent mixing and wave overturning processes, mountain wave drag, downstream effects, and the mesoscale predictability of wave breaking. The current limit in our knowledge of gravity wave breaking can be partially attributed to lack of observations. During the Fronts and Atlantic Storm-Track Experiment (FASTEX), a large amplitude gravity wave was observed in the lee of Greenland on 29 January 1997. Observations taken collected during FASTEX presented a unique opportunity to study topographically forced gravity wave breaking and to assess the ability of high-resolution numerical models to predict the structure and evolution of such phenomena. Measurements from the NOAA G-4 research aircraft and high-resolution numerical simulations are used to study the evolution and dynamics of the large-amplitude gravity wave event that took place during the FASTEX. Vertical cross section analysis of dropwindsonde data, with 50-km horizontal spacing, indicates the presence of a large amplitude breaking gravity wave that extends from above the 150-hPa level to 500 hPa. Flight-level data indicate a horizontal shear of over 10-3 s-1 across the breaking wave with 25 K potential temperature perturbations. This breaking wave may have important implications for momentum flux parameterization in mesoscale models, stratospheric-tropospheric exchange dynamics as well as the dynamic sources and sinks of the ozone budget. Additionally, frequent breaking waves over Greenland are a known commercial and military aviation hazard. NRL's nonhydrostatic COAMPS^{TM}$ model is used with four nested grids with horizontal resolutions of 45 km, 15 km, 5 km and 1.67 km and 65 vertical levels to simulate the gravity wave event. The model simulation captures the temporal evolution and horizontal structure of the wave. However, the model underestimates the vertical amplitude of the wave. The model simulation suggests that the breaking wave may be triggered as a consequence of vertically propagating internal gravity waves emanating from katabatic flow near the extreme slopes of eastern Greenland. Additionally, a number of simulations that make use of a horizontally homogeneous initial state and both idealized and actual Greenland topography are performed. These simulations highlight the sensitivity of gravity wave amplification and breaking to the planetary rotation, slope of the Greenland topography, representation of turbulent mixing, and surface processes.

Evaluation of Aztreonam Dosing Regimens in Patients With Normal and Impaired Renal Function: A Population Pharmacokinetic Modeling and Monte Carlo Simulation Analysis.

PubMed

Xu, Hongmei; Zhou, Wangda; Zhou, Diansong; Li, Jianguo; Al-Huniti, Nidal

2017-03-01

Aztreonam is a monocyclic β-lactam antibiotic often used to treat infections caused by Enterobacteriaceae or Pseudomonas aeruginosa. Despite the long history of clinical use, population pharmacokinetic modeling of aztreonam in renally impaired patients is not yet available. The aims of this study were to assess the impact of renal impairment on aztreonam exposure and to evaluate dosing regimens for patients with renal impairment. A population model describing aztreonam pharmacokinetics following intravenous administration was developed using plasma concentrations from 42 healthy volunteers and renally impaired patients from 2 clinical studies. The final pharmacokinetic model was used to predict aztreonam plasma concentrations and evaluate the probability of pharmacodynamic target attainment (PTA) in patients with different levels of renal function. A 2-compartment model with first-order elimination adequately described aztreonam pharmacokinetics. The population mean estimates of aztreonam clearance, intercompartmental clearance, volume of distribution of the central compartment, and volume of distribution of the peripheral compartment were 4.93 L/h, 9.26 L/h, 7.43 L, and 6.44 L, respectively. Creatinine clearance and body weight were the most significant variables to explain patient variability in aztreonam clearance and volume of distribution, respectively. Simulations using the final pharmacokinetic model resulted in a clinical susceptibility break point of 4 and 8 mg/L, respectively, based on the clinical use of 1- and 2-g loading doses with the same or reduced maintenance dose every 8 hours for various renal deficiency patients. The population pharmacokinetic modeling and PTA estimation support adequate PTAs (>90% PTA) from the aztreonam label for dose adjustment of aztreonam in patients with moderate and severe renal impairment. © 2016, The American College of Clinical Pharmacology.

Break-even analysis of Medicaid vs fee for service in orthodontic practice: North Carolina as a case study.

PubMed

Murdock, John E; Phillips, Ceib; Beane, Richard; Quinonez, Rocio

2010-03-01

Access to orthodontic services for children enrolled in Medicaid is limited nationwide. Orthodontists cite low fee reimbursement as a significant barrier to Medicaid participation. The purpose of this study was to examine, under a specific set of practice assumptions, the simulated effect on profitability of treating patients covered by Medicaid in orthodontic practices in North Carolina by using a break-even analysis for the 2005 fiscal year. Questionnaires were mailed to 154 orthodontists in active practice in North Carolina. The response rate was 58%. Seventy respondents met the eligibility criteria. Respondents were categorized into 4 groups based on the number of 2005 Medicaid case starts (I, 0; II, 1-5; III, 6-12; IV, 13 or more). By using the aggregated responses for treatment fees, treatment times, and overhead percentages for each group, average per-patient costs were calculated for each group and used in a break-even analysis. Group I accounted for 60% of respondents; group II, 20%; group III, 9%; and group IV, 11%. Assuming that the break-even point had not been reached, the group I practice would have an average estimated loss of $164 per patient whereas groups II, III, and IV would realize average profits from $98 to $256. The break-even point increased slightly in groups I, II, and III after the total number of patients in the patient pool was increased by 5%, assuming that additional patients were enrolled in Medicaid: group I, 203 to 210; group II, 220 to 226; group III, 158 to 160. The break-even point for group IV was 234 patients. Assuming that the break-even point had been reached, all groups were estimated to realize average per-patient profits of $1483 to $1897. Break-even analysis is a basic economic concept applicable to orthodontic practices. Under the specific conditions of this study, the inclusion of 5% of patients enrolled in Medicaid in the active patient pool had minimal effect on the financial break-even point and, assuming that the break-even point had been reached, was unlikely to have a negative financial impact on the practice. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Guiding Inquiry with Biography Breaks and the C3 Framework: Can One Person Make a Difference?

ERIC Educational Resources Information Center

Young, Terrell A.; Miner, Amy Baird

2015-01-01

The purpose of this article is to explore how teachers can use biography breaks to address the National Council of the Social Studies C3 inquiry framework and in the process meet requirements of the Common Core State Standards. We begin by illustrating and explaining biography breaks. Then we introduce the C3 framework and explain as well as…

Betting Decision Under Break-Streak Pattern: Evidence from Casino Gaming.

PubMed

Fong, Lawrence Hoc Nang; So, Amy Siu Ian; Law, Rob

2016-03-01

Cognitive bias is prevalent among gamblers, especially those with gambling problems. Grounded in the heuristics theories, this study contributes to the literature by examining a cognitive bias triggered by the break streak pattern in the casino setting. We postulate that gamblers tend to bet on the latest outcome when there is a break-streak pattern. Moreover, three determinants of the betting decision under break-streak pattern, including the streak length of the alternative outcome, the frequency of the latest outcome, and gender, were identified and examined in this study. A non-participatory observational study was conducted among the Cussec gamblers in a casino in Macao. An analysis of 1229 bets confirms our postulation, particularly when the streak of the alternative outcome is long, the latest outcome is frequent, and the gamblers are females. The findings provide meaningful implications for casino management and public policymakers regarding the minimization of gambling harm.

Impact of an aseptic procedure for breaking the integrity of the urinary drainage system on the development of catheter-associated urinary tract infections in the intensive care unit.

PubMed

Powers, Jan

2016-12-01

Catheter associated urinary tract infections (CAUTI) are a common complication in the hospital, especially in intensive care units (ICU). These infections are directly linked to the use of an indwelling urinary catheter. One commonly identified factor related to the development of CAUTI has been thought to be violating the integrity of the closed drainage system. However, a paucity of research exists to support or refute this practice. The primary purpose of this observational study was to assess if there is a relationship between CAUTI incidence and breaking the closed drainage system using an aseptic procedure. A process improvement effort was developed to ensure an aseptic technique was utilised when there was a need to break the integrity of the urinary drainage system. Because this was a new practice and not supported by the Centres for Disease Control (CDC) recommendations, this change in practice was evaluated as an observational study. In an eight month period there were 53 documented breaks in the urinary drainage system. There were 28 total cases of CAUTI overall during this same time period. Only four patients with a system break developed a CAUTI (7.5%). In almost 93% of the patients where aseptic technique was used for breaks in the drainage system, there was no occurrence of CAUTI. A follow-up evaluation was performed after a year of this practice in three adult ICUs. During this three month evaluation period, there were 47 documented cases of breaking this system using aseptic technique. Of the patients who had a documented break in their drainage system, none developed subsequent CAUTIs. One commonly identified factor related to the development of CAUTI has been thought to be violating the integrity of the closed drainage system. However, a paucity of research exists to support or refute this practice. This observational study found that utilising an aseptic technique to break the integrity system did not result in an associated increase in CAUTI. Copyright © 2016 Elsevier Ltd. All rights reserved.

Facilitating working mothers' ability to breastfeed: global trends in guaranteeing breastfeeding breaks at work, 1995-2014.

PubMed

Atabay, Efe; Moreno, Gonzalo; Nandi, Arijit; Kranz, Gabriella; Vincent, Ilona; Assi, Tina-Marie; Winfrey, Elise Marie Vaughan; Earle, Alison; Raub, Amy; Heymann, S Jody

2015-02-01

Mothers who work away from home tend to stop breastfeeding earlier than their nonworking counterparts due to workplace barriers. Barriers to breastfeeding discriminate against women and may lead to inequities in children's health outcomes. Guaranteeing paid breastfeeding breaks at work is 1 mechanism that can improve mothers' opportunity to breastfeed in the workplace. This study aimed to assess the trends in the share of countries guaranteeing breastfeeding breaks in the workplace and paid maternal leave that lasts until the infant is 6 months old (the World Health Organization recommended duration for exclusive breastfeeding), between 1995 and 2014. Legislation and secondary source data were collected and reviewed for 193 United Nations member states. Legislation was analyzed for content on breastfeeding breaks and maternal leave guarantees. Fifty-one countries (26.7%) in 2014 did not guarantee breastfeeding breaks in any form and 4 countries provided only unpaid breaks or breaks that did not cover the first 6 months of life; since 1995, around 15 countries (10.2%) legislated for such a policy. In 2014, out of 55 countries that did not guarantee paid breastfeeding breaks for the first 6 months after birth, 7 countries guaranteed paid maternal leave for the same duration; 48 countries (25.1%) provided neither paid maternal leave nor paid breastfeeding breaks. Progress in the number of countries guaranteeing breastfeeding breaks at work is modest. Adopting measures to facilitate breastfeeding at work can be a critical opportunity for countries to increase breastfeeding rates among the growing number of women in the labor force. © The Author(s) 2014.

Breastfeeding policy: a globally comparative analysis.

PubMed

Heymann, Jody; Raub, Amy; Earle, Alison

2013-06-01

To explore the extent to which national policies guaranteeing breastfeeding breaks to working women may facilitate breastfeeding. An analysis was conducted of the number of countries that guarantee breastfeeding breaks, the daily number of hours guaranteed, and the duration of guarantees. To obtain current, detailed information on national policies, original legislation as well as secondary sources on 182 of the 193 Member States of the United Nations were examined. Regression analyses were conducted to test the association between national policy and rates of exclusive breastfeeding while controlling for national income level, level of urbanization, female percentage of the labour force and female literacy rate. Breastfeeding breaks with pay are guaranteed in 130 countries (71%) and unpaid breaks are guaranteed in seven (4%). No policy on breastfeeding breaks exists in 45 countries (25%). In multivariate models, the guarantee of paid breastfeeding breaks for at least 6 months was associated with an increase of 8.86 percentage points in the rate of exclusive breastfeeding (P < 0.05). A greater percentage of women practise exclusive breastfeeding in countries where laws guarantee breastfeeding breaks at work. If these findings are confirmed in longitudinal studies, health outcomes could be improved by passing legislation on breastfeeding breaks in countries that do not yet ensure the right to breastfeed.

Activity-rest schedules in physically demanding work and the variation of responses with age.

PubMed

Kakarot, Nadine; Mueller, Friedrich; Bassarak, Claudia

2012-01-01

Workers in physically demanding occupations require work breaks to recover from exertion. In a laboratory setting, we investigated the impact of ergometer cycling for 7 h in two conditions with an identical total break time but with two different activity-rest schedules. We hypothesised that more frequent but shorter breaks lead to less psychophysical strain and its effects than do less frequent but longer breaks, particularly for older workers. Twenty-nine participants representing three different age groups were tested in both conditions. Heart rate, perceived exertion/tension and feelings of fatigue were assessed and used as dependent variables. Results indicate no general activity-rest differences as well as no age-related differences of break effects under the condition of subjectively equal straining load. However, heart rate was found to be lower at some measurement points in the frequent-short-break condition and perceived exertion was lower in the infrequent-long-break condition. Design of activity-rest schedules in physically demanding occupations is a key issue in the prevention of strain and hence of interest to ergonomists. Our study suggests that breaks during physically demanding work have the same effect if they are frequent and short or infrequent and long, regardless of age.

Hypsometry, volume and physiography of the Arctic Ocean and their paleoceanographic implications

NASA Astrophysics Data System (ADS)

Jakobsson, M.; Macnab, R.; Grantz, A.; Kristoffersen, Y.

2003-04-01

Recent analyses of the International Bathymetric Chart of the Arctic Ocean (IBCAO) grid model include: Hypsometry (the distribution of surface area at various depths); ocean volume distribution; and physiographic provinces [Jakobsson 2002; Jakobsson et al., in press]. The present paper summarizes the main results from these recent studies and expands on the paleoceanographic implications for the Arctic Ocean, which in this work is defined as the broad continental shelves of the Barents, Kara, Laptev, East Siberian and Chukchi Seas, the White Sea and the narrow continental shelves of the Beaufort Sea, the Arctic continental margins off the Canadian Arctic Archipelago and northern Greenland. This, the World's smallest ocean, is a virtually land-locked ocean that makes up merely 2.6 % of the area, and 1.0 % of the volume, of the entire World Ocean. The continental shelf area, from the coastline out to the shelf break, comprises as much as 52.9 % of the total area in the Arctic Ocean, which is significantly larger in comparison to the rest of the world oceans where the proportion of shelves, from the coastline out to the foot of the continental slope, only ranges between about 9.1 % and 17.7 %. In Jakobsson [2002], the seafloor area and water volume were calculated for different depths starting from the present sea level and progressing in increments of 10 m to a depth of 500 m, and in increments of 50 m from 550 m down to the deepest depth within each of the analyzed Arctic Ocean seas. Hypsometric curves expressed as simple histograms of the frequencies in different depth bins were presented, along with depth plotted against cumulative area for each of the analyzed seas. The derived hypsometric curves show that most of the Arctic Ocean shelf seas besides the Barents Sea, Beaufort Sea and the shelf off northern Greenland have a similar shape with the largest seafloor area between 0 and 50 m. The East Siberian and Laptev seas, in particular, show area distributions concentrated in this shallow depth range, and together with the Chukchi Sea they form a large flat shallow shelf province comprising as much as 22 % of the entire Arctic Ocean area, but only 1 % of the volume. Given this vast shelf area it may be speculated that the Arctic Ocean circulation is more sensitive to eustatic sea level changes compared to the other world oceans. For example, during the LGM when the sea level was ca 120 m lower than today most, if not all, of the Arctic Ocean shelf region could not play a role in the ocean circulation. Besides being the world's smallest ocean with the by far largest shelf area in proportion to its size, the Arctic Ocean is unique in terms of its physiographic setting. The Fram Strait is the only real break in the barrier of vast continental shelves enclosing the Arctic Ocean. The second largest physiographic province after the continental shelves consists of ridges, which is in contrast to the rest of the World's oceans where abyssal plains dominate. As much as 15.8 % of the area is underlain by ridges indicating the profound effect they have on ocean circulation. Jakobsson, M., Grantz, A., Kristoffersen, Y., and Macnab, R., in press, Physiographic Provinces of the Arctic Ocean, GSA Bulletin. Jakobsson, M., 2002, Hypsometry and volume of the Arctic Ocean and its constituent’s seas, Geochemistry Geophysics Geosystems, v. 3, no. 2.

Quark Propagator with electroweak interactions in the Dyson-Schwinger approach

NASA Astrophysics Data System (ADS)

Mian, Walid Ahmed; Maas, Axel

2017-03-01

Motivated by the non-negligible dynamical backcoupling of the electroweak interactions with the strong interaction during neutron star mergers, we study the effects of the explicit breaking of C, P and flavor symmetry on the strong sector. The quark propagator is the simplest object which encodes the consequences of these breakings. To asses the impact, we study the influence of especially parity violation on the propagator for various masses. For this purpose the functional methods in form of Dyson-Schwinger-Equations are employed. We find that explicit isospin breaking leads to a qualitative change of behavior even for a slight explicit breaking, which is in contrast to the expectations from perturbation theory. Our results thus suggest that non-perturbative backcoupling effects could be larger than expected.

Dynamical Symmetry Breaking in Models of Spinor Fields with Quartic Interactions in (1+1) Dimensions

NASA Astrophysics Data System (ADS)

Wang, Rhung-tai; Ni, Guang-jiong

1982-07-01

A nonperturbative method, namely, variational method together with canonical transformations, is developed to study dynamical symmetry breaking. This method has been applied in the models of two dimensional massless fermion fields with quartic interactions. The results imply that the mechanism of dynamical symmetry breaking bears some analogy to the phenomenon of superconductivity. The new vacuum \\mid \\tilde{0}> is just a relativistic BCS groundstate, In this vacuum \\mid ^≈0>, we can observe a quasi-particle with mass "MF" Furthermore, correlative vacuum \\mid ^≈0> exists and the mesons emerge with masses "O" and "2MF". It is also shown that dynamical symmetry breaking always occurs in the models with infrared slavery and asymptotic freedom, while it is meaningless to discuss dynamical symmetry breaking in infrared stable theory.

[Observation on therapeutic effect of dry eye syndrome treated with acupuncture on the acupoints around the eyes].

PubMed

Gao, Wei-Ping; Liu, Min; Zhang, Yi-Biao

2010-06-01

To observed the clinical efficacy on dry eye syndrome treated with acupuncture on the acupoints around the eyes. Fifty-six cases of dry eye syndrome were divided into two groups, acupuncture group and western medicine group, 28 cases in each one. In acupuncture group, acupuncture was applied to Jingming (BL 1), Cuanzhu (BL 2), Sizhukong (TE 23), Tongziliao (GB 1), etc. In western medicine group, the topical artificial tear eye drops were administered. The corneal fluorescein staining, breaking-up time (BUT), tear volume and the symptom score were observed before and after treatment in two groups. In comparison before and after treatment in acupuncture group, the statistical significant difference presented in BUT, tear volume and the symptom score (all P < 0.01). In comparison before and after treatment in western medicine group, the statistical significant difference presented in corneal staining, BUT and the symptom score (P < 0.01). The improvements in BUT, tear volume and the symptom score in acupuncture group were superior to those in western medicine group (P < 0.01). Acupuncture on the acupoints around the eyes achieves a quite good efficacy on dry eye syndrome.

Studying breaking of inverted emulsions with thermolysis purification TD600

NASA Astrophysics Data System (ADS)

Tarasova, G. I.; Shevaga, O. N.; Grachyova, E. O.

2018-03-01

Currently, emulsions are used in many branches of industry and agriculture. It explains significant attention paid to issues in production, stabilization and breaking of emulsion. Besides, producing steady emulsions is of importance in many processes; the reverse problem, that of demulsification, is important as well in oil production and treatment of oil emulsion waste water. This paper studies the breaking (demulsification) of inverted emulsions with the help of thermolysis purification TD600, produced by thermal modification of purification, a large-scale waste of the sugar industry.

Extreme plasma states in laser-governed vacuum breakdown.

PubMed

Efimenko, Evgeny S; Bashinov, Aleksei V; Bastrakov, Sergei I; Gonoskov, Arkady A; Muraviev, Alexander A; Meyerov, Iosif B; Kim, Arkady V; Sergeev, Alexander M

2018-02-05

Triggering vacuum breakdown at laser facility is expected to provide rapid electron-positron pair production for studies in laboratory astrophysics and fundamental physics. However, the density of the produced plasma may cease to increase at a relativistic critical density, when the plasma becomes opaque. Here, we identify the opportunity of breaking this limit using optimal beam configuration of petawatt-class lasers. Tightly focused laser fields allow generating plasma in a small focal volume much less than λ 3 and creating extreme plasma states in terms of density and produced currents. These states can be regarded to be a new object of nonlinear plasma physics. Using 3D QED-PIC simulations we demonstrate a possibility of reaching densities over 10 25  cm -3 , which is an order of magnitude higher than expected earlier. Controlling the process via initial target parameters provides an opportunity to reach the discovered plasma states at the upcoming laser facilities.

Facile preparation of porous carbon from coffee bean waste using low temperature solvothermal method

NASA Astrophysics Data System (ADS)

Baroroh, L. A. Al; Fitria, D.; Amal, M. I.; Wismogroho, A. S.; Widayatno, W. B.

2018-03-01

In this study, porous carbon made from coffee bean waste (CBW) was carbonized at 500 °C, 600 °C, and 700 °C to find effective temperature. It is verified from the IR spectrum that carbonization process at certain temperature can effectively break cellulose bonding and make aromatics functional group while preserving its carbon structure. The TG-DTA curve shows four stages of decomposition process and confirms most effective carbonization temperature. Activation process of as-carbonized CBW was carried out using solvothermal method in KOH and NH4OH steam environment at 200 °C with variation of 30%, 40%, and 50% solvothermal volume. Scanning electron micrographs reveals significant increase of porosity on the carbon surface and differences of structural pores between the variations. The results show the possible potential of utilizing low temperature-solvothermal method for nanoporous carbon material.

An analysis of howling response parameters useful for wolf pack censusing

USGS Publications Warehouse

Harrington, F.H.; Mech, L.D.

1982-01-01

Gray wolves (Canis lupus) were studied from April-1972 through April 1974 in the Superior National Forest in northeastern Minnesota by radio-tracking and simulated howling. Based on replies during 217 of 456 howling sessions, the following recommendations were derived for using simulated howling as a census technique: (1) the best times of day are dusk and night; (2) July, August, and September are the best months; (3) precipitation and winds greater than 12 km/hour should be aVQided; (4) a sequence of 5 single howls should be used, alternating 'flat' and 'breaking' howls; (5) trials should be repeated 3 times at about 2-minute intervals with the first trial at lower volume; and (6) the trial series should be repeated on 3 nights as close to each other as possible. Two censuses are described: a saturation census and a sampling census.

Can the optimum artificial tear treatment for dry eye disease be predicted from presenting signs and symptoms?

PubMed

Essa, Laika; Laughton, Deborah; Wolffsohn, James S

2018-02-01

To assess dry eye treatment with four preservative-free dry eye artificial tear treatments to facilitate evidence-based prescribing. A randomised, single masked crossover trial of Clinitas Soothe, Hyabak, Tears Again and TheraTears artificial tears was conducted on 50 symptomatic dry eye patients, aged 60.8±14.2years. At baseline and after trialling each treatment for 4 weeks, signs and symptoms were assessed using the Ocular Surface Disease Index (OSDI), non-invasive tear break-up time, fluorescein tear break-up time, tear meniscus height (TMH), Phenol Red test, lid-parallel conjunctival folds (LIPCOF), ocular surface staining, and lipid layer grading and osmolarity (baseline visit only). OSDI (p=0.002), LIPCOF (p=0.014) and conjunctival staining (p<0.001) significantly improved from baseline, however, the impact of each dry eye treatment on ocular symptoms and signs was similar. Clinitas Soothe and Hyabak were preferred by 34%/30% of participants, but only subjective comparison with the other drops influenced this choice. TheraTears was preferred (by 24%) by those with a lower baseline tear volume (p=0.01) and Tears Again (by 12%) by those with a thinner baseline lipid layer (p=0.04). The treatment that afforded the greatest improvement in clinical signs did not consistently match each individual's preferred treatment. If prescribed to a general dry eye population, the artificial tears performed similarly, improving symptoms and conjunctival signs. However, osmolarity balanced artificial tears were the preferred treatment in individuals with low baseline tear volume and lipisomal spray for individuals with a baseline lipid layer deficiency. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington

NASA Technical Reports Server (NTRS)

Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W., Jr. (Editor)

1995-01-01

This volume, the first of two comprising the technical report for this workshop, contains papers that have been accepted for presentation at the Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region, September 24-30, 1995, in Spokane, Washington. The Mars Pathfinder Project received a new start in October 1993 as one of the next missions in NASA's long-term Mars exploration program. The mission involves landing a single vehicle on the surface of Mars in 1997. The project is one of the first Discovery-class missions and is required to be a quick, low-cost mission and achieve a set of significant but focused engineering, science, and technology objectives. The primary objective is to demonstrate a low-cost cruise, entry, descent, and landing system required to place a payload on the martian surface in a safe, operational configuration. Additional objectives include the deployment and operation of various science instruments and a microrover. Pathfinder paves the way for a cost-effective implementation of future Mars lander missions. Also included in this volume is the field trip guide to the Channeled Scabland and Missoula Lake Break-out. On July 4, 1997, Mars Pathfinder is scheduled to land near 19.5 deg N, 32.8 deg W, in a portion of Ares Vallis. The landing ellipse covers a huge (100 x 200 km) area that appears to include both depositional and erosional landforms created by one or more giant, catastrophic floods. One of the best known terrestrial analogs to martian outflow channels (such as Ares Vallis) is the region known as the Channeled Scabland. The field trip guide describes some of the geomorphological features of the Channeled Scabland and adjacent Lake Missoula break-out area near Lake Pend Oreille, Idaho.

Challenge Online Time Series Clustering For Demand Response A Theory to Break the ‘Curse of Dimensionality'

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

Pal, Ranjan; Chelmis, Charalampos; Aman, Saima

The advent of smart meters and advanced communication infrastructures catalyzes numerous smart grid applications such as dynamic demand response, and paves the way to solve challenging research problems in sustainable energy consumption. The space of solution possibilities are restricted primarily by the huge amount of generated data requiring considerable computational resources and efficient algorithms. To overcome this Big Data challenge, data clustering techniques have been proposed. Current approaches however do not scale in the face of the “increasing dimensionality” problem where a cluster point is represented by the entire customer consumption time series. To overcome this aspect we first rethinkmore » the way cluster points are created and designed, and then design an efficient online clustering technique for demand response (DR) in order to analyze high volume, high dimensional energy consumption time series data at scale, and on the fly. Our online algorithm is randomized in nature, and provides optimal performance guarantees in a computationally efficient manner. Unlike prior work we (i) study the consumption properties of the whole population simultaneously rather than developing individual models for each customer separately, claiming it to be a ‘killer’ approach that breaks the “curse of dimensionality” in online time series clustering, and (ii) provide tight performance guarantees in theory to validate our approach. Our insights are driven by the field of sociology, where collective behavior often emerges as the result of individual patterns and lifestyles.« less

Achiral symmetry breaking and positive Gaussian modulus lead to scalloped colloidal membranes

PubMed Central

Gibaud, Thomas; Kaplan, C. Nadir; Sharma, Prerna; Zakhary, Mark J.; Ward, Andrew; Oldenbourg, Rudolf; Meyer, Robert B.; Kamien, Randall D.; Powers, Thomas R.; Dogic, Zvonimir

2017-01-01

In the presence of a nonadsorbing polymer, monodisperse rod-like particles assemble into colloidal membranes, which are one-rod-length–thick liquid-like monolayers of aligned rods. Unlike 3D edgeless bilayer vesicles, colloidal monolayer membranes form open structures with an exposed edge, thus presenting an opportunity to study elasticity of fluid sheets. Membranes assembled from single-component chiral rods form flat disks with uniform edge twist. In comparison, membranes composed of a mixture of rods with opposite chiralities can have the edge twist of either handedness. In this limit, disk-shaped membranes become unstable, instead forming structures with scalloped edges, where two adjacent lobes with opposite handedness are separated by a cusp-shaped point defect. Such membranes adopt a 3D configuration, with cusp defects alternatively located above and below the membrane plane. In the achiral regime, the cusp defects have repulsive interactions, but away from this limit we measure effective long-ranged attractive binding. A phenomenological model shows that the increase in the edge energy of scalloped membranes is compensated by concomitant decrease in the deformation energy due to Gaussian curvature associated with scalloped edges, demonstrating that colloidal membranes have positive Gaussian modulus. A simple excluded volume argument predicts the sign and magnitude of the Gaussian curvature modulus that is in agreement with experimental measurements. Our results provide insight into how the interplay between membrane elasticity, geometrical frustration, and achiral symmetry breaking can be used to fold colloidal membranes into 3D shapes. PMID:28411214

Effect of D-psicose used as sucrose replacer on the characteristics of meringue.

PubMed

O'Charoen, Siwaporn; Hayakawa, Shigeru; Matsumoto, Yoshiki; Ogawa, Masahiro

2014-12-01

Excessive intake of sugar-rich foods leads to metabolic syndrome. D-Psicose (Psi) not commonly found in nature, is noncalorie sweetener with a suppressive effect on the blood glucose level. Thus, Psi has the potential to be utilized as a sucrose (Suc) replacer in sugar-rich foods, including meringue-based confectionery (MBC). In this study, we investigated the effect of Psi on the physical and chemical properties of meringue. Meringue was made by whipping egg white and Suc (at a weight ratio of 1:1) and baking at 93 °C for 2 h. Thirty percent of the total weight of Suc was replaced with D-ketohexoses such as Psi, D-fructose, D-tagatose, and D-sorbose. The meringues containing D-ketohexoses had higher specific volume than the meringue not containing D-ketohexoses (Ct-meringue). Baking of meringue caused differences between Psi and the other D-ketohexose meringues. Meringue containing Psi (P30-meringue) had the highest breaking stress (7.00 × 10(5) N/m(2)) and breaking strain (4.40%), resulting in the crunchiest texture. In addition, P30-meringue also had the highest antioxidant activity (491.84 μM TE/mg-meringue determined by ABTS method) and was the brownest due to a Maillard reaction occurring during baking. The replacement of Suc with Psi improved the characteristics of baked meringue. Thus, Psi was found to be useful in modifying the physical and chemical properties of MBC. © 2014 Institute of Food Technologists®

Use of a thin-section archive and enterprise 3D software for long-term storage of thin-slice CT data sets.

PubMed

Meenan, Christopher; Daly, Barry; Toland, Christopher; Nagy, Paul

2006-01-01

Rapid advances are changing the technology and applications of multidetector computed tomography (CT) scanners. The major increase in data associated with this new technology, however, breaks most commercial picture archiving and communication system (PACS) architectures by preventing them from delivering data in real time to radiologists and outside clinicians. We proposed a phased model for 3D workflow, installed a thin-slice archive and measured thin-slice data storage over a period of 5 months. A mean of 1,869 CT studies were stored per month, with an average of 643 images per study and a mean total volume of 588 GB/month. We also surveyed 48 radiologists to determine diagnostic use, impressions of thin-slice value, and requirements for retention times. The majority of radiologists thought thin slice was helpful for diagnosis and regularly used the application. Permanent storage of thin slice CT is likely to become best practice and a mission-critical pursuit for the health care enterprise.

Statistical methods and computing for big data.

PubMed

Wang, Chun; Chen, Ming-Hui; Schifano, Elizabeth; Wu, Jing; Yan, Jun

2016-01-01

Big data are data on a massive scale in terms of volume, intensity, and complexity that exceed the capacity of standard analytic tools. They present opportunities as well as challenges to statisticians. The role of computational statisticians in scientific discovery from big data analyses has been under-recognized even by peer statisticians. This article summarizes recent methodological and software developments in statistics that address the big data challenges. Methodologies are grouped into three classes: subsampling-based, divide and conquer, and online updating for stream data. As a new contribution, the online updating approach is extended to variable selection with commonly used criteria, and their performances are assessed in a simulation study with stream data. Software packages are summarized with focuses on the open source R and R packages, covering recent tools that help break the barriers of computer memory and computing power. Some of the tools are illustrated in a case study with a logistic regression for the chance of airline delay.

Fractional Brownian motion and motion governed by the fractional Langevin equation in confined geometries.

PubMed

Jeon, Jae-Hyung; Metzler, Ralf

2010-02-01

Motivated by subdiffusive motion of biomolecules observed in living cells, we study the stochastic properties of a non-Brownian particle whose motion is governed by either fractional Brownian motion or the fractional Langevin equation and restricted to a finite domain. We investigate by analytic calculations and simulations how time-averaged observables (e.g., the time-averaged mean-squared displacement and displacement correlation) are affected by spatial confinement and dimensionality. In particular, we study the degree of weak ergodicity breaking and scatter between different single trajectories for this confined motion in the subdiffusive domain. The general trend is that deviations from ergodicity are decreased with decreasing size of the movement volume and with increasing dimensionality. We define the displacement correlation function and find that this quantity shows distinct features for fractional Brownian motion, fractional Langevin equation, and continuous time subdiffusion, such that it appears an efficient measure to distinguish these different processes based on single-particle trajectory data.

Statistical methods and computing for big data

PubMed Central

Wang, Chun; Chen, Ming-Hui; Schifano, Elizabeth; Wu, Jing

2016-01-01

Big data are data on a massive scale in terms of volume, intensity, and complexity that exceed the capacity of standard analytic tools. They present opportunities as well as challenges to statisticians. The role of computational statisticians in scientific discovery from big data analyses has been under-recognized even by peer statisticians. This article summarizes recent methodological and software developments in statistics that address the big data challenges. Methodologies are grouped into three classes: subsampling-based, divide and conquer, and online updating for stream data. As a new contribution, the online updating approach is extended to variable selection with commonly used criteria, and their performances are assessed in a simulation study with stream data. Software packages are summarized with focuses on the open source R and R packages, covering recent tools that help break the barriers of computer memory and computing power. Some of the tools are illustrated in a case study with a logistic regression for the chance of airline delay. PMID:27695593

Outdoor dissolution of detonation residues of three insensitive munitions (IM) formulations.

PubMed

Taylor, Susan; Dontsova, Katerina; Walsh, Marianne E; Walsh, Michael R

2015-09-01

We seek to understand the environmental fate of three new insensitive munitions, explosive formulations developed to reduce the incidence of unintended detonations. To this end, we measured the size distribution of residues from low order detonations of IMX 101, IMX 104, and PAX 21-filled munitions and are studying how these three formulations weather and dissolve outdoors. The largest pieces collected from the detonations were centimeter-sized and we studied 12 of these in the outdoors test. We found that the particles break easily and that the dissolution of 2,4-dinitroanisole (DNAN) is quasi-linear as a function of water volume. DNAN is the matrix and the least soluble major constituent of the three formulations. We used DNAN's linear dissolution rate to estimate the life span of the pieces. Particles ranging in mass from 0.3 to 3.5 g will completely dissolve in 3-21 years given 100 cm y(-1) precipitation rates. Published by Elsevier Ltd.

Breaking bad news of cancer diagnosis – Perception of the cancer patients in a rural community in Malaysia

PubMed Central

Bain, Mathew Gabriel; Lian, Cheah Whye; Thon, Chang Ching

2014-01-01

Context: Breaking of bad news is an important component in the management of cancer patients. Aims: This study aimed to assess the perceptions of breaking bad news of cancer diagnosis. Settings and Design: It was a cross-sectional study using Breaking Bad News Assessment Schedule (BAS) questionnaire on cancer patients in Serian district. Materials and Methods: Using snowballing sampling method, a total of 134 patients were interviewed face-to-face after the consent was obtained from each of the respondents. Statistical Analysis Used: Data was entered and analyzed using SPSS version 19.0. Results: Majority were comfortable with the current method of breaking bad news. The main aspects found to be the areas of concern were the importance of the usage of body language, management of time and identifying patients’ key area of concerns. There were significant difference between sex and “information giving” (P = 0.028) and “general consideration” (P = 0.016) and also between “the age and setting the scene” (P = 0.042). Significant difference was also found between the types of cancer and “the setting of scene” (P = 0.018), “breaking bad news technique” (P = 0.010), “eliciting concerns” (P = 0.003) and “information giving” (P = 0.004). Conclusion: Good and effective communication skill of breaking bad news is vital in the management of cancer patients. As the incidence of new cases of cancer increase every year, breaking of bad news has become a pertinent to the medical professionals’ role. Specific aspects of communication skills based on local characteristics should be more emphasized in the formulation of training for doctors. PMID:24818107

A swath across the great divide: Kelp forests across the Samalga Pass biogeographic break

USGS Publications Warehouse

Konar, Brenda H.; Edwards, Matthew S.; Bland, Aaron; Metzger, Jacob; Ravelo, Alexandra; Traiger, Sarah; Weitzman, Ben P.

2017-01-01

Biogeographic breaks are often described as locations where a large number of species reach their geographic range limits. Samalga Pass, in the eastern Aleutian Archipelago, is a known biogeographic break for the spatial distribution of several species of offshore-pelagic communities, including numerous species of cold-water corals, zooplankton, fish, marine mammals, and seabirds. However, it remains unclear whether Samalga Pass also serves as a biogeographic break for nearshore benthic communities. The occurrence of biogeographic breaks across multiple habitats has not often been described. In this study, we examined if the biogeographic break for offshore-pelagic communities applies to nearshore kelp forests. To examine whether Samalga Pass serves as a biogeographic break for kelp forest communities, this study compared abundance, biomass and percent bottom cover of species associated with kelp forests on either side of the pass. We observed marked differences in kelp forest community structure, with some species reaching their geographic range limits on the opposing sides of the pass. In particular, the habitat-forming kelp Nereocystis luetkeana, and the predatory sea stars Pycnopodia helianthoides and Orthasterias koehleri all occurred on the eastern side of Samalga Pass but were not observed west of the pass. In contrast, the sea star Leptasterias camtschatica dispar was observed only on the western side of the pass. We also observed differences in overall abundance and biomass of numerous associated fish, invertebrate and macroalgal species on opposing sides of the pass. We conclude that Samalga Pass is important biogeographic break for kelp forest communities in the Aleutian Archipelago and may demark the geographic range limits of several ecologically important species.

Predicting Tissue Breaking Strengths in the Epileptic Brain with T2 Relaxometry: Application of Pulsed Water Jet Dissection System for Epilepsy Surgery.

PubMed

Takahashi, Yoko; Iwasaki, Masaki; Nakagawa, Atsuhiro; Sato, Shiho; Nakasato, Nobukazu; Tominaga, Teiji

2017-11-01

Background  The piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. Using the ADPJ system in epilepsy surgery requires prediction of the tissue breaking strength of the epileptic brain. The aim of this study was to elucidate whether magnetic resonance imaging T2 relaxometry could predict the breaking strength. Methods  A total of 12 patients with drug-resistant temporal lobe epilepsy who received surgical treatment were included in the study. All the patients qualified for surgery after a comprehensive preoperative evaluation for the treatment of epilepsy. T2 relaxation time, breaking strength of the hippocampus, and an anterior temporal lobe specimen obtained from surgery with dissection depth determined by the ADPJ system were examined. Results  Preoperative T2 relaxation times of the anterior temporal lobe and hippocampus showed mild positive correlation with breaking strength (R 2  = 0.60). The hippocampus showed higher T2 relaxation time than the temporal lobe. Hippocampal sclerosis seemed to have higher breaking strength than other pathologies, suggesting the correlation depends on the anatomical location and histopathology. The dissection depth of the extirpated lesion was negatively correlated with the breaking strength at input voltages of 10 V (R 2  = - 0.34) and 20 V (R 2  = - 0.20). Conclusions  T2 relaxometry may be useful to predict tissue breaking strength in the epileptic brain that allows safe application of the ADPJ system in epilepsy surgery. Georg Thieme Verlag KG Stuttgart · New York.

Web-Based Intervention to Change Perceived Norms of College Student Alcohol Use and Sexual Behavior on Spring Break

PubMed Central

Patrick, Megan E.; Lee, Christine M.; Neighbors, Clayton

2014-01-01

The purpose of the present study was to evaluate an adapted web-based multi-component personalized feedback intervention to reduce college student alcohol use and risky sexual behavior during Spring Break. This is one of the first interventions focused on Spring Break alcohol use and related sexual behavior. Personalized feedback intervention components addressed intentions, expected consequences, norms, motivations, protective behavioral strategies, and pacts with friends. Participants were college students (N=263; 55% women) between the ages of 18 and 21 who planned to go on a Spring Break trip with their friends. Effects were not significant in reducing alcohol use or sexual behavior during Spring Break or some of the proposed intervention mechanisms. However, consistent results showed that the intervention succeeded in reducing perceived social norms for Spring Break drinking and sexual behavior. Findings suggest that changing norms alone is not sufficient for changing risk behavior during this event and alternative strategies are needed to impact other putative mediators. PMID:24333038

A prediction method of ice breaking resistance using a multiple regression analysis

NASA Astrophysics Data System (ADS)

Cho, Seong-Rak; Lee, Sungsu

2015-07-01

The two most important tasks of icebreakers are first to secure a sailing route by breaking the thick sea ice and second to sail efficiently herself for purposes of exploration and transportation in the polar seas. The resistance of icebreakers is a priority factor at the preliminary design stage; not only must their sailing efficiency be satisfied, but the design of the propulsion system will be directly affected. Therefore, the performance of icebreakers must be accurately calculated and evaluated through the use of model tests in an ice tank before construction starts. In this paper, a new procedure is developed, based on model tests, to estimate a ship's ice breaking resistance during continuous ice-breaking in ice. Some of the factors associated with crushing failures are systematically considered in order to correctly estimate her ice-breaking resistance. This study is intended to contribute to the improvement of the techniques for ice resistance prediction with ice breaking ships.

Chromosomal radiosensitivity in head and neck cancer patients: evidence for genetic predisposition?

PubMed Central

De Ruyck, K; de Gelder, V; Van Eijkeren, M; Boterberg, T; De Neve, W; Vral, A; Thierens, H

2008-01-01

The association between chromosomal radiosensitivity and genetic predisposition to head and neck cancer was investigated in this study. In all, 101 head and neck cancer patients and 75 healthy control individuals were included in the study. The G2 assay was used to measure chromosomal radiosensitivity. The results demonstrated that head and neck cancer patients had a statistically higher number of radiation-induced chromatid breaks than controls, with mean values of 1.23 and 1.10 breaks per cell, respectively (P<0.001). Using the 90th percentile of the G2 scores of the healthy individuals as a cutoff value for chromosomal radiosensitivity, 26% of the cancer patients were radiosensitive compared with 9% of the healthy controls (P=0.008). The mean number of radiation-induced chromatid breaks and the proportion of radiosensitive individuals were highest for oral cavity cancer patients (1.26 breaks per cell, 38%) and pharynx cancer patients (1.27 breaks per cell, 35%). The difference between patients and controls was most pronounced in the lower age group (⩽50 years, 1.32 breaks per cell, 38%) and in the non- and light smoking patient group (⩽10 pack-years, 1.28 breaks per cell, 46%). In conclusion, enhanced chromosomal radiosensitivity is a marker of genetic predisposition to head and neck cancer, and the genetic contribution is highest for oral cavity and pharynx cancer patients and for early onset and non- and light smoking patients. PMID:18414410

The impacts of rest breaks and stretching exercises on lower back pain among commercial truck drivers in Iran.

PubMed

Ghasemi, Mohammad; Khoshakhlagh, Amir Hossein; Ghanjal, Ali; Yazdanirad, Saeid; Laal, Fereydoon

2018-06-07

This study aimed to determine the impacts of rest breaks and stretching exercises on lower back pain (LBP) in commercial truck drivers. This quasi-experiment was carried out on 92 truck drivers suffering from chronic LBP. Subjects were categorized into three groups (stretching exercises and rest breaks, rest breaks only and reference). Pain severity and related disability were measured at the beginning of the survey and after 6 and 12 weeks. The latter was assessed using the Oswestry low back pain disability questionnaire (OLBPDQ) and the Roland Morris questionnaire (RMQ). At the end of the intervention, the mean pain scores in the three groups were 2.72 ± 1.44, 4.11 ± 0.86 and 4.90 ± 1.31 respectively (p < 0.001). The OLBPDQ scores in group 1 (stretches and resting time breaks) were significantly lower than those in group 2 (rest break) (p = 0.009). The RMQ scores showed a significant reduction in group 1 compared with the other two groups (p = 0.001). Drivers in group 2 improved more significantly than those in group 3 regarding visual analog scale pain score (p = 0.049), OLBPDQ score (p = 0.024) and RMQ score (p = 0.011). This study provided converging results that supplementary exercises during break periods consistently help to minimize LBP and disability.

The UP4FUN Intervention Effect on Breaking Up Sedentary Time in 10- to 12-Year-Old Belgian Children: The ENERGY-Project.

PubMed

Verloigne, Maïté; Berntsen, Sveinung; Ridgers, Nicola D; Cardon, Greet; Chinapaw, Mai; Altenburg, Teatske; Brug, Johannes; Bere, Elling; De Bourdeaudhuij, Ilse; Van Lippevelde, Wendy; Maes, Lea

2015-05-01

There are currently no studies available reporting intervention effects on breaking up children's sedentary time. This study examined the UP4FUN intervention effect on objectively measured number of breaks in sedentary time, number of sedentary bouts (≥ 10 mins) and total and average amount of time spent in those sedentary bouts among 10- to 12-year-old Belgian children. The total sample included 354 children (mean age: 10.9 ± 0.7 years; 59% girls) with valid ActiGraph accelerometer data at pre- and posttest. Only few and small intervention effects were found, namely on total time spent in sedentary bouts immediately after school hours (4-6PM; β = -3.51mins) and on average time spent in sedentary bouts before school hours (6-8.30AM; β = -4.83mins) and immediately after school hours in favor of children from intervention schools (β = -2.71mins). Unexpectedly, girls from intervention schools decreased the number of breaks during school hours (8.30AM-4PM; β = -23.45breaks) and increased the number of sedentary bouts on a weekend day (β = +0.90bouts), whereas girls in control schools showed an increase in number of breaks and a decrease in number of bouts. In conclusion, UP4FUN did not have a consistent or substantial effect on breaking up children's sedentary time and these data suggest that more intensive and longer lasting interventions are needed.

Breaking bad news in cancer patients.

PubMed

Konstantis, Apostolos; Exiara, Triada

2015-01-01

In a regional hospital, many patients are newly diagnosed with cancer. Breaking the bad news in these patients and their relatives is a tough task. Many doctors are not experienced in talking to patients about death or death-related diseases. In recent years, there have been great efforts to change the current situation. The aim of this study was to investigate the experience and education of medical personnel in breaking bad news in a secondary hospital. 59 doctors from General Hospital of Komotini, Greece were included in the study. All the doctors were in clinical specialties that treated cancer patients. A brief questionnaire was developed based on current guidelines such as Baile/SPIKES framework and the ABCDE mnemonic. Residents are involved in delivering bad news less frequently than specialists. Only 21 doctors (35.59%) had specific training on breaking bad news. 20 doctors (33.90%) were aware of the available techniques and protocols on breaking bad news. 47 doctors (79.66%) had a consistent plan for breaking bad news. 57 (96.61%) delivered bad news in a quiet place, 53 (89.83%) ensured no interruptions and enough time, 53 (89.83%) used simple words and 54 (91.53%) checked for understanding and did not rush through the news. 46 doctors (77.97%) allowed relatives to determine patient's knowledge about the disease. There were low rates of specific training in breaking bad news. However, the selected location, the physician's speech and their plan were according to current guidelines.

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men’s basketball games

PubMed Central

Favero, TG; Niederhausen, M; Capranica, L; Tessitore, A

2017-01-01

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1st-division (elite) and fifteen 3rd-division (sub-elite) Italian men’s championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p<0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions. PMID:28566812

Chromosomal radiosensitivity in head and neck cancer patients: evidence for genetic predisposition?

PubMed

De Ruyck, K; de Gelder, V; Van Eijkeren, M; Boterberg, T; De Neve, W; Vral, A; Thierens, H

2008-05-20

The association between chromosomal radiosensitivity and genetic predisposition to head and neck cancer was investigated in this study. In all, 101 head and neck cancer patients and 75 healthy control individuals were included in the study. The G(2) assay was used to measure chromosomal radiosensitivity. The results demonstrated that head and neck cancer patients had a statistically higher number of radiation-induced chromatid breaks than controls, with mean values of 1.23 and 1.10 breaks per cell, respectively (P<0.001). Using the 90th percentile of the G(2) scores of the healthy individuals as a cutoff value for chromosomal radiosensitivity, 26% of the cancer patients were radiosensitive compared with 9% of the healthy controls (P=0.008). The mean number of radiation-induced chromatid breaks and the proportion of radiosensitive individuals were highest for oral cavity cancer patients (1.26 breaks per cell, 38%) and pharynx cancer patients (1.27 breaks per cell, 35%). The difference between patients and controls was most pronounced in the lower age group (

The etiology of the association between child antisocial behavior and maternal negativity varies across aggressive and non-aggressive rule-breaking forms of antisocial behavior

PubMed Central

Klahr, Ashlea M.; Klump, Kelly L.; Burt, S. Alexandra

2014-01-01

There is a robust association between negative parenting and child antisocial behavior problems. However, the etiology of this association remains unclear. Extant literature has reported strikingly different conclusions across studies, with some highlighting genetic mediation and others highlighting environmental mediation. One possible reason for these discrepancies across studies may be the failure to differentiate between aggressive and non-aggressive (rule-breaking) dimensions of childhood antisocial behavior, given their notably different etiologies and developmental trajectories (Burt, 2012). The current study sought to examine the phenotypic and etiologic associations of maternal negativity with aggressive and rule-breaking antisocial behavior, respectively. Participants included 824 mothers and their twin children between the ages of 6 and 10. Our results highlighted clear etiologic distinctions in the associations of aggression and rule-breaking with maternal negativity. Aggression was associated with maternal negativity via both genetic and environmental factors, whereas the association between non-aggressive rule-breaking and maternal negativity was entirely environmental in origin. These findings provide additional support for the presence of meaningful distinctions between aggressive and non-aggressive forms of antisocial behavior, and highlight the complex relationship between parenting and child outcome. PMID:24906982

The effect of various factors on the masticatory performance of removable denture wearer

NASA Astrophysics Data System (ADS)

Pratama, S.; Koesmaningati, H.; Kusdhany, L. S.

2017-08-01

An individual’s masticatory performance concerns his/her ability to break down food in order to facilitate digestion, and it therefore plays an important role in nutrition. Removable dentures are used to rehabilitate a loss of teeth, which could jeopardize masticatory performance. Further, there exist various other factors that can affect masticatory performance. The objective of this research is to analyze the relationship between various factors and masticatory performance. Thirty-four removable denture wearers (full dentures, single complete dentures, or partial dentures) participated in a cross-sectional study of masticatory performance using color-changeable chewing gum (Masticatory Performance Evaluating Gum Xylitol®). The volume of saliva was evaluated using measuring cups, while the residual ridge heights were measured using a modified mouth mirror no. 3 with metric measurements. The residual ridge height and removable-denture-wearing experience exhibited a significant relationship with masticatory performance. However, age, gender, saliva volume, denture type, and the number and location of the missing teeth did not have a statistically significant association with masticatory performance. The residual ridge height influences the masticatory performance of removable denture wearers, since the greater the ridge height, the better the performance. The experience of using dentures also has a statistically significant influence on masticatory performance.

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

Yang, Kang; Wu, Sujun; Guan, Juan

Strong and tough epoxy composites are developed using a less-studied fibre reinforcement, that of natural silk. Two common but structurally distinct silks from the domestic B. mori/Bm and the wild A. pernyi/Ap silkworms are selected in fabric forms. We show that the toughening effects on silk-epoxy composites or SFRPs are dependent on the silk species and the volume fraction of silk. Both silks enhance the room-temperature tensile and flexural mechanical properties of the composite, whereas the more resilient Ap silk shows a more pronounced toughening effect and a lower critical reinforcement volume for the brittle-ductile transition. Specifically, our 60 vol.%more » Ap-SFRP displays a three-fold elevation in tensile and flexural strength, as compared to pure epoxy resin, with an order of magnitude higher breaking energy via a distinct, ductile failure mode. Importantly, the 60 vol.% Ap-SFRP remains ductile with 7% flexural elongation at lower temperatures (-50 °C). Under impact, these SFRPs show significantly improved energy absorption, and the 60 vol.% Ap-SFRP has an impact strength some eight times that of pure epoxy resin. Lastly, the findings demonstrate both marked toughening and strengthening effects for epoxy composites from natural silk reinforcements, which presents opportunities for mechanically superior and "green" structural composites.« less

Enhancing the Mechanical Toughness of Epoxy-Resin Composites Using Natural Silk Reinforcements

DOE PAGES

Yang, Kang; Wu, Sujun; Guan, Juan; ...

2017-09-20

Strong and tough epoxy composites are developed using a less-studied fibre reinforcement, that of natural silk. Two common but structurally distinct silks from the domestic B. mori/Bm and the wild A. pernyi/Ap silkworms are selected in fabric forms. We show that the toughening effects on silk-epoxy composites or SFRPs are dependent on the silk species and the volume fraction of silk. Both silks enhance the room-temperature tensile and flexural mechanical properties of the composite, whereas the more resilient Ap silk shows a more pronounced toughening effect and a lower critical reinforcement volume for the brittle-ductile transition. Specifically, our 60 vol.%more » Ap-SFRP displays a three-fold elevation in tensile and flexural strength, as compared to pure epoxy resin, with an order of magnitude higher breaking energy via a distinct, ductile failure mode. Importantly, the 60 vol.% Ap-SFRP remains ductile with 7% flexural elongation at lower temperatures (-50 °C). Under impact, these SFRPs show significantly improved energy absorption, and the 60 vol.% Ap-SFRP has an impact strength some eight times that of pure epoxy resin. Lastly, the findings demonstrate both marked toughening and strengthening effects for epoxy composites from natural silk reinforcements, which presents opportunities for mechanically superior and "green" structural composites.« less

Evaluating crude oil chemical dispersion efficacy in a flow-through wave tank under regular non-breaking wave and breaking wave conditions.

PubMed

Li, Zhengkai; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2009-05-01

Testing dispersant effectiveness under conditions similar to that of the open environment is required for improvements in operational procedures and the formulation of regulatory guidelines. To this end, a novel wave tank facility was fabricated to study the dispersion of crude oil under regular non-breaking and irregular breaking wave conditions. This wave tank facility was designed for operation in a flow-through mode to simulate both wave- and current-driven hydrodynamic conditions. We report here an evaluation of the effectiveness of chemical dispersants (Corexit EC9500A and SPC 1000) on two crude oils (Medium South American [MESA] and Alaska North Slope [ANS]) under two different wave conditions (regular non-breaking and plunging breaking waves) in this wave tank. The dispersant effectiveness was assessed by measuring the water column oil concentration and dispersed oil droplet size distribution. In the absence of dispersants, nearly 8-19% of the test crude oils were dispersed and diluted under regular wave and breaking wave conditions. In the presence of dispersants, about 21-36% of the crude oils were dispersed and diluted under regular waves, and 42-62% under breaking waves. Consistently, physical dispersion under regular waves produced large oil droplets (volumetric mean diameter or VMD > or = 300 microm), whereas chemical dispersion under breaking waves created small droplets (VMD < or = 50 microm). The data can provide useful information for developing better operational guidelines for dispersant use and improved predictive models on dispersant effectiveness in the field.

The application of the Practitioners in Applied Practice Model during breaking bad news communication training for medical students: a case study.

PubMed

Dunning, Rose; Laidlaw, Anita

2015-11-01

Breaking bad news is a key skill within clinical communication and one which can impact outcomes for both the patient and practitioner. The evidence base for effective clinical communication training in breaking bad news is scarce. Frameworks have been found to assist the practitioner, such as SPIKES; however, the pedagogical approach used alongside such frameworks can vary. This study sought to examine the impact of utilising the Practitioners in Applied Practice Model (PAPM) alongside the SPIKES framework for training undergraduate medical students in breaking bad news. A case study approach is used to highlight the impact of training based on the PAPM and SPIKES on patient-centred communication and simulated patient satisfaction with the clinical communication behaviour. Results showed that following training, both patient-centred behaviour and patient satisfaction improved. With detailed communication behaviour changes, a balance was established between rapport building behaviour, lifestyle and psychosocial talk alongside biomedical information. This case study shows how the PAPM could be utilised alongside the SPIKES framework to improve breaking bad news communication in medical undergraduate students and describes the behavioural basis of the improvement. Further research is required to show the generalisability of this training intervention. © The Author(s) 2015.

Different singularities in the functions of extended kinetic theory at the origin of the yield stress in granular flows

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

Berzi, Diego; Vescovi, Dalila

2015-01-15

We use previous results from discrete element simulations of simple shear flows of rigid, identical spheres in the collisional regime to show that the volume fraction-dependence of the stresses is singular at the shear rigidity. Here, we identify the shear rigidity, which is a decreasing function of the interparticle friction, as the maximum volume fraction beyond which a random collisional assembly of grains cannot be sheared without developing force chains that span the entire domain. In the framework of extended kinetic theory, i.e., kinetic theory that accounts for the decreasing in the collisional dissipation due to the breaking of molecularmore » chaos at volume fractions larger than 0.49, we also show that the volume fraction-dependence of the correlation length (measure of the velocity correlation) is singular at random close packing, independent of the interparticle friction. The difference in the singularities ensures that the ratio of the shear stress to the pressure at shear rigidity is different from zero even in the case of frictionless spheres: we identify that with the yield stress ratio of granular materials, and we show that the theoretical predictions, once the different singularities are inserted into the functions of extended kinetic theory, are in excellent agreement with the results of numerical simulations.« less

Suspended sand transport in surf zones

NASA Astrophysics Data System (ADS)

Kobayashi, Nobuhisa; Zhao, Haoyu; Tega, Yukiko

2005-12-01

Three tests were conducted in a wave flume to investigate time-averaged suspended sediment transport processes under irregular breaking waves on equilibrium beaches consisting of fine sand. Free surface elevations were measured at ten locations for each test. Velocities and concentrations were measured in the vicinity of the bottom at 94 elevations along 17 vertical lines. The relations among the three turbulent velocity variances are found to be similar to those for the boundary layer flow. The vertical variation of the mean velocity, which causes offshore transport, is fitted by a parabolic profile fairly well. The vertical variation of the mean concentration ? is fitted by the exponential and power-form distributions equally well. The ratio between the concentration standard deviation σC and the mean ? varies little vertically. The correlation coefficient γUC between the horizontal velocity and concentration, which results in onshore transport, is of the order of 0.1 and decreases upward linearly. The offshore and onshore transport rates of suspended sediment are estimated and expressed in terms of the suspended sediment volume ? per unit area. A time-averaged numerical model is developed to predict ? as well as the mean and standard deviation of the free surface elevation and horizontal velocity. The bottom slope effect on the wave energy dissipation rate DB due to wave breaking is included in the model. The computation can be made well above the still water shoreline with no numerical difficulty. Reflected waves from the shoreline are estimated from the wave energy flux remaining at the shoreline. The numerical model is in agreement with the statistical data except that the undertow current is difficult to predict accurately. The measured turbulent velocities are found to be more related to the turbulent velocity estimated from the energy dissipation rate Df due to bottom friction. The suspended sediment volume ? expressed in terms of DB and Df can be predicted only within a factor of about 2. The roller effect represented by the roller volume flux does not necessarily improve the agreement for the three tests.

TH-CD-201-11: Optimizing the Response and Cost of a DNA Double-Strand Break Dosimeter

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

Obeidat, M; Cline, K; Stathakis, S

Purpose: A DNA double-strand break (DSB) dosimeter was developed to measure the biological effect of radiation. The goal here is to refine the fabrication method of this dosimeter to reproducibly create a low coefficient of variation (CoV) and reduce the cost for the dosimeter. Methods: Our dosimeter consists of 4 kilo-base pair DNA strands (labeled on one end with biotin and on the other with fluorescein) attached to streptavidin magnetic beads. The final step of the DNA dosimeter fabrication is to suspend these attached beads in phosphate-buffered saline (PBS). The amount of PBS used to suspend the attached beads andmore » the relative volume of the DNA strands to the beads both affect the CoV and dosimeter cost. We diluted the beads attached with DNA in different volumes of PBS (100, 200, and 400 µL) to create different concentrations of the DNA dosimeter. Then we irradiated these dosimeters (50 µL samples) in a water-equivalent plastic phantom at 25 and 50 Gy (three samples per dose) and calculated the CoV for each dosimeter concentration. Also, we used different masses of DNA strands (1, 2, 8, 16, 24, and 32 µg) to attach to the same volume of magnetic beads (100 µL) to explore how this affects the cost of the dosimeter. Results: The lowest CoV was produced for the highest concentration of dosimeter (100 µL of PBS), which created CoV of 2.0 and 1.0% for 25 and 50 Gy, respectively. We found that the lowest production cost for the dosimeter occurs by attaching 16 µg of DNA strands with 100 µL of beads. Conclusion: : We optimized the fabrication of the DNA dosimeter to produce low CoV and cost, but we still need to explore ways to further improve the dosimeter for use at lower doses. This work was supported in part by Yarmouk University (Irbid, Jordan) and CPRIT (RP140105)« less

Two Simple Models for Fracking

NASA Astrophysics Data System (ADS)

Norris, Jaren Quinn

Recent developments in fracking have enable the recovery of oil and gas from tight shale reservoirs. These developments have also made fracking one of the most controversial environmental issues in the United States. Despite the growing controversy surrounding fracking, there is relatively little publicly available research. This dissertation introduces two simple models for fracking that were developed using techniques from non-linear and statistical physics. The first model assumes that the volume of induced fractures must be equal to the volume of injected fluid. For simplicity, these fractures are assumed to form a spherically symmetric damage region around the borehole. The predicted volumes of water necessary to create a damage region with a given radius are in good agreement with reported values. The second model is a modification of invasion percolation which was previously introduced to model water flooding. The reservoir rock is represented by a regular lattice of local traps that contain oil and/or gas separated by rock barriers. The barriers are assumed to be highly heterogeneous and are assigned random strengths. Fluid is injected from a central site and the weakest rock barrier breaks allowing fluid to flow into the adjacent site. The process repeats with the weakest barrier breaking and fluid flowing to an adjacent site each time step. Extensive numerical simulations were carried out to obtain statistical properties of the growing fracture network. The network was found to be fractal with fractal dimensions differing slightly from the accepted values for traditional percolation. Additionally, the network follows Horton-Strahler and Tokunaga branching statistics which have been used to characterize river networks. As with other percolation models, the growth of the network occurs in bursts. These bursts follow a power-law size distribution similar to observed microseismic events. Reservoir stress anisotropy is incorporated into the model by assigning horizontal bonds weaker strengths on average than vertical bonds. Numerical simulations show that increasing bond strength anisotropy tends to reduce the fractal dimension of the growing fracture network, and decrease the power-law slope of the burst size distribution. Although simple, these two models are useful for making informed decisions about fracking.

Insights From Field Geology Into the Styles and Timings of Large Silicic Explosive `Supereruptions'

NASA Astrophysics Data System (ADS)

Wilson, C. J.

2006-12-01

The evocative terms `supereruption' (and `supervolcano'), whilst eminently saleable to the media, conceal the fact that, apart from knowing that such large eruptions (>300 km3, magma) actually have occurred, we understand very little about the dynamics of such events. Field studies of 3 supereruption deposits suggest that we are missing information on the timing and eruptive styles that is essential in assessing the dynamics and impacts of past and future large eruptions. The 26.5 ka Oruanui eruption in New Zealand (ca. 530 km3, magma) shows evidence in the form of erosion intervals and/or reworked horizons for spasmodic activity, including a hiatus of weeks plus other shorter breaks, that interrupted 10 phases of activity. Following the plinian fall unit of phase 1, there was a time break long enough for local reworking (and possibly emplacement of a small dome), thus of the order of weeks in duration. Other breaks, during which minor wind- or water-reworking took place are observed between phases 4 and 5, and 9 and 10, and were of the order of days. Two other horizons saw the complete settling out of 10-20 micron-sized ash particles before commencement of the next phase of the eruption, and thus may represent breaks of hours. The whole eruption was a series of large-scale outbreaks of generally increasing vigor, daisy-chained to form a single geological event, but one which would represent recurrent hazards, and uncertainties in eruptive activity if repeated today. The 0.76 Ma Bishop Tuff eruption (ca. 600 km3, magma), on the other hand, displays evidence only for one short time break, represented by settling out of fine ash at the top of a plinian pumice fall unit. Most of the eruption volume may have been emplaced over only about 6 days. Such an eruption, although catastrophic when placed in today's societal context, at least was over relatively rapidly. The immense 2.06 Ma Huckleberry Ridge Tuff (HRT) eruption (ca. 2500 km3, magma) shows evidence for prolonged time breaks, possibly of months to years, at several stages. During deposition of the basal pre- ignimbrite fall deposit, horizons of wind- and/or water-reworked material occur, suggesting that normal weather processes (wind, hail deposition, rainfall) may have affected the deposits during breaks in deposition. Between the three major ignimbrite units (A, B and C), there is local evidence for cooling below temperatures required for welding across their mutual boundaries and partial cessation of vapour-phase alteration in the earlier unit where the ignimbrites thin against topographic highs. A false impression of continuity in HRT emplacement is given by a lack of significant density contrasts across unit boundaries in areas where the deposits were thick enough to cause high temperatures and concomitant welding across the mutual contacts. All three eruptions show evidence for partial or complete simultaneity of plinian pumice fall deposition with co- generation and emplacement of ignimbrite. The widespread notions of fall and flow activity being antipathetic and of the former leading to the latter are too simple, especially given the demonstrable development of multiple vent sites in the Oruanui and Bishop eruptions. All three eruptions show that there is a wealth of information to be gained from detailed field studies that can provide powerful constraints on eruption dynamics, although it is apparent that there is no simple model that can be applied to supereruptions. Two out of the three examples were prolonged for months or years, and assessing when the eruption would have actually finished, or foreseeing the climactic stage(s) which would have caused the greatest impact, would have been problematic.

Organisational Rules in Schools: Teachers' Opinions about Functions of Rules, Rule-Following and Breaking Behaviours in Relation to Their Locus of Control

ERIC Educational Resources Information Center

Demirkasimoglu, Nihan; Aydin, Inayet; Erdogan, Cetin; Akin, Ugur

2012-01-01

The main aim of this research is to examine teachers' opinions about functions of school rules, reasons for rule-breaking and results of rule-breaking in relation to their locus of control, gender, age, seniority and branch. 350 public elementary school teachers in Ankara are included in the correlational survey model study. According to the…

Orbital transfer vehicle launch operations study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1986-01-01

The purpose was to use the operational experience at the launch site to identify, describe and quantify the operational impacts of the various configurations on the Kennedy Space Center (KSC) and/or space station launch sites. Orbital Transfer Vehicle (OTV) configurations are being developed/defined by contractor teams. Lacking an approved configuration, the KSC Study Team defined a Reference Configuration to be used for this study. This configuration then become the baseline for the identification of the facilities, personnel and crew skills required for processing the OTV in a realistic manner that would help NASA achieve the lowest possible OTV life cycle costs. As the study progressed, researchers' initial apraisal that the vehicle, when delivered, would be a sophisticated, state-of-the-art vehicle was reinforced. It would be recovered and reused many times so the primary savings to be gained would be in the recurring-cycle of the vehicle operations--even to the point where it would be beneficial to break from tradition and make a significant expenditure in the development of processing facilities at the beginning of the program.

Kinetics of chromatid break repair in G2-human fibroblasts exposed to low- and high-LET radiations

NASA Technical Reports Server (NTRS)

Kawata, T.; Durante, M.; George, K.; Furusawa, Y.; Gotoh, E.; Takai, N.; Wu, H.; Cucinotta, F. A.

2001-01-01

The purpose of this study is to determine the kinetics of chromatid break rejoining following exposure to radiations of different quality. Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (290 MeV/u), silicon (490 MeV/u) and iron (200 MeV/u, 600 MeV/u). Chromosomes were prematurely condensed using calyculin A. Prematurely condensed chromosomes were collected after several post-irradiation incubation times, ranging from 5 to 600 minutes, and the number of chromatid breaks and exchanges in G2 cells were scored. The relative biological effectiveness (RBE) for initial chromatid breaks per unit dose showed LET dependency having a peak at 55 keV/micrometers silicon (2.4) or 80 keV/micrometers carbon particles (2.4) and then decreased with increasing LET. The kinetics of chromatid break rejoining following low- or high-LET irradiation consisted of two exponential components. Chromatid breaks decreased rapidly after exposure, and then continued to decrease at a slower rate. The rejoining kinetics was similar for exposure to each type of radiation, although the rate of unrejoined breaks was higher for high-LET radiation. Chromatid exchanges were also formed quickly.

The Influence of Break Timing on the Sleep Quantity and Quality of Fly-in, Fly-out Shiftworkers

PubMed Central

PAECH, Gemma M.; FERGUSON, Sally A.; BANKS, Siobhan; DORRIAN, Jillian; ROACH, Gregory D.

2014-01-01

Although shift and break timing is known to affect the sleep of shiftworkers, this has not been demonstrated in Fly-in, Fly-out (FIFO) settings which, compared to residential based settings, may be favourable for sleep. This study investigated the sleep quantity and quality of shiftworkers working a FIFO operation comprising of shifts, and therefore breaks, across the 24-h day. The sleep of 24 males (50.43 ± 8.57 yr) was measured using actigraphy and sleep diaries. Morning breaks were associated with less sleep (09:00–12:00 h; 4.4 ± 1.3 h) and a poorer sleep quality (06:00–09:00 h; 3.1 ± 1.0, “average”) compared to breaks beginning between 00:00 h and 03:00 h (6.8 ± 1.7 h; 2.2 ± 0.9, “good”). Sleep efficiency remained constant regardless of break timing (85.9 ± 5.0% to 89.9 ± 3.5%). Results indicate that even in operations such as FIFO where sleeping conditions are near-optimal and the break duration is held constant, the influence of the endogenous circadian pacemaker on sleep duration is evident. PMID:25224336

GIS data models for coal geology

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

McColloch, G.H. Jr.; Timberlake, K.J.; Oldham, A.V.

A variety of spatial data models can be applied to different aspects of coal geology. The simple vector data models found in various Computer Aided Drafting (CAD) programs are sometimes used for routine mapping and some simple analyses. However, more sophisticated applications that maintain the topological relationships between cartographic elements enhance analytical potential. Also, vector data models are best for producing various types of high quality, conventional maps. The raster data model is generally considered best for representing data that varies continuously over a geographic area, such as the thickness of a coal bed. Information is lost when contour linesmore » are threaded through raster grids for display, so volumes and tonnages are more accurately determined by working directly with raster data. Raster models are especially well suited to computationally simple surface-to-surface analysis, or overlay functions. Another data model, triangulated irregular networks (TINs) are superior at portraying visible surfaces because many TIN programs support break fines. Break lines locate sharp breaks in slope such as those generated by bodies of water or ridge crests. TINs also {open_quotes}honor{close_quotes} data points so that a surface generated from a set of points will be forced to pass through those points. TINs or grids generated from TINs, are particularly good at determining the intersections of surfaces such as coal seam outcrops and geologic unit boundaries. No single technique works best for all coal-related applications. The ability to use a variety of data models, and transform from one model to another is essential for obtaining optimum results in a timely manner.« less

The effects of volume versus intensity of long-term voluntary exercise on physiology and behavior in C57/Bl6 mice.

PubMed

Robison, Lisa S; Popescu, Dominique L; Anderson, Maria E; Beigelman, Steven I; Fitzgerald, Shannon M; Kuzmina, Antonina E; Lituma, David A; Subzwari, Sarima; Michaelos, Michalis; Anderson, Brenda J; Van Nostrand, William E; Robinson, John K

2018-06-04

Cardiovascular exercise (CVE) is associated with healthy aging and reduced risk of disease in humans, with similar benefits seen in animals. Most rodent studies, however, have used shorter intervention periods of a few weeks to a few months, begging questions as to the effects of longer-term, or even life-long, exercise. Additionally, most animal studies have utilized a single exercise treatment group - usually unlimited running wheel access - resulting in large volumes of exercise that are not clinically relevant. It is therefore incumbent to determine the physiological and cognitive/behavioral effects of a range of exercise intensities and volumes over a long-term period that model a lifelong commitment to CVE. In the current study, C57/Bl6 mice remained sedentary or were allowed either 1, 3, or 12 h of access to a running wheel per day, 5 days/weeks, beginning at 3.5-4 months of age. Following an eight-month intervention period, animals underwent a battery of behavioral testing, then euthanized and blood and tissue were collected. Longer access to a running wheel resulted in greater volume and higher running speed, but more breaks in running. All exercise groups showed similarly reduced body weight, increased muscle mass, improved motor function on the rotarod, and reduced anxiety in the open field. While all exercise groups showed increased food intake, this was greatest in the 12 h group but did not differ between 1 h and 3 h mice. While exercise dose-dependently increased working memory performance in the y-maze, the 1 h and 12 h groups showed the largest changes in the mass of many organs, as well as alterations in several behaviors including social interaction, novel object recognition, and Barnes maze performance. These findings suggest that long-term exercise has widespread effects on physiology, behavior, and cognition, which vary by "dose" and measure, and that even relatively small amounts of daily exercise can provide benefits. Copyright © 2018. Published by Elsevier Inc.

A theoretical study of symmetry-breaking organic overlayers on single- and bi-layer graphene

NASA Astrophysics Data System (ADS)

Morales-Cifuentes, Josue; Einstein, T. L.

2013-03-01

An ``overlayer'' of molecules that breaks the AB symmetry of graphene can produce (modify) a band gap in single- (bi-) layer graphene.[2] Since the triangular shaped trimesic acid (TMA) molecule forms two familiar symmetry breaking configurations, we are motivated to model TMA physisorption on graphene surfaces in conjunction with experiments by Groce et al. at UMD. Using VASP, with ab initio van der Waals density functionals (vdW-DF), we simulate adsorption of TMA onto a graphene surface in several symmetry-breaking arrangements in order to predict/understand the effect of TMA adsorption on experimental observables. Supported by NSF-MRSEC Grant DMR 05-20471.

Microphysics and dynamics of the gamma-ray burst 121024A

NASA Astrophysics Data System (ADS)

Varela, K.; van Eerten, H.; Greiner, J.; Schady, P.; Elliott, J.; Sudilovsky, V.; Krühler, T.; van der Horst, A. J.; Bolmer, J.; Knust, F.; Agurto, C.; Azagra, F.; Belloche, A.; Bertoldi, F.; De Breuck, C.; Delvaux, C.; Filgas, R.; Graham, J. F.; Kann, D. A.; Klose, S.; Menten, K. M.; Nicuesa Guelbenzu, A.; Rau, A.; Rossi, A.; Schmidl, S.; Schuller, F.; Schweyer, T.; Tanga, M.; Weiss, A.; Wiseman, P.; Wyrowski, F.

2016-05-01

Aims: The aim of the study is to constrain the physics of gamma-ray bursts (GRBs) by analysing the multi-wavelength afterglow data set of GRB 121024A that covers the full range from radio to X-rays. Methods: Using multi-epoch broad-band observations of the GRB 121024A afterglow, we measured the three characteristic break frequencies of the synchrotron spectrum. We used six epochs of combined XRT and GROND data to constrain the temporal slopes, the dust extinction, the X-ray absorption, and the spectral slope with high accuracy. Two more epochs of combined data from XRT, GROND, APEX, CARMA, and EVLA were used to set constraints on the break frequencies and therefore on the micro-physical and dynamical parameters. Results: The XRT and GROND light curves show a simultaneous and achromatic break at around 49 ks. As a result, the crossing of the synchrotron cooling break is no suitable explanation for the break in the light curve. The multi-wavelength data allow us to test two plausible scenarios explaining the break: a jet break, and the end of energy injection. The jet-break scenario requires a hard electron spectrum, a very low cooling break frequency, and a non-spreading jet. The energy injection avoids these problems, but requires ɛe > 1 (k = 2), spherical outflow, and ɛB < 10-9. Conclusions: In light of the extreme microphysical parameters required by the energy-injection model, we favour a jet-break scenario where νm < νsa to explain the observations. This scenario gives physically meaningful microphysical parameters, and it also naturally explains the reported detection of linear and circular polarisation.

A numerical model of gravity wave breaking and stress in the mesosphere

NASA Technical Reports Server (NTRS)

Schoeberl, M. R.; Strobel, D. F.; Apruzese, J. P.

1983-01-01

The goal of the study is to calculate numerically the deceleration and heating caused by breaking gravity waves. The effect of the radiative dissipation of the wave is included as vertical-wavelength-dependent Newtonian cooling. The parameterization for zonal deceleration is extended by breaking gravity waves (Lindzen, 1981) to include the turbulent diffusion of heat and momentum. After describing the numerical model, the numerical results are presented and compared with the parameterizations in a noninteractive model of the mean zonal wind. Attention is then given to the transport of constituents by gravity waves and the attendant turbulent zone. It is noted that if gravity wave breaking were not an intermittent process, gravity wave stresses would produce an adiabatic mesosphere with a zonal mean velocity close to the phase speed of the breaking wave.

Different modes of continental break-up triggered by a sole mantle plume: a 2D and 3D numerical study

NASA Astrophysics Data System (ADS)

Beniest, Anouk; Koptev, Alexander; Leroy, Sylvie; Burov, Evgueni

2017-04-01

We used 2D and 3D numerical models to investigate the impact of a single mantle plume on continental rifting and breakup processes. We varied the thermo-rheological structure of the continental lithosphere, its geometry and the initial plume position. Based on the results of our 2D experiments, three continental break-up modes can be distinguished: A) 'central' continental break-up, the break-up center is located directly above the original mantle anomaly position, B) 'shifted' break-up, the break-up center is 50 to 200 km displaced from the initial plume location and C) 'distant' break-up, due to convection and/or slab-subduction/delamination, the break-up center is considerably shifted (300 to 800 km) from the primary plume position. Our 3D model, with a laterally homogeneous initial setup also results in continental break-up with the axis of continental break-up hundreds of kilometers shifted from the original plume location. The model results show that the classical, 'central' view of mantle plume induced continental break-up is not the only mode of break-up. When considering a diversity of break-up styles, it is possible to explain a variety of observed geophysical and geological features. For example, the mantle material glued to the base of the lithosphere at shallower depths corresponds geometrically and location-wise to high-velocity/high-density bodies observed on seismic data below the thinned continental lithosphere and the transition zone of the South Atlantic domain. During migration, products of partial melting of the mantle material can move vertically to (shallow) lower crustal levels. They might resemble high density bodies observed at lower crustal levels inside continental crust with similar geometries observed with gravity modelling. Also, topographic variation form in the very early stages of rifting on the first impingement of upwelled plume material. These variations remain visible, as the final position of the spreading center is shifted from the point of impingement and can be interpreted as aborted rifts, observed along passive margins. Our modelling demonstrates that both simple and perfectly symmetric preliminary settings as well as complex initial setups can result in a variety of break-up systems.

Acute Effects of Classroom Exercise Breaks on Executive Function and Math Performance: A Dose-Response Study.

PubMed

Howie, Erin K; Schatz, Jeffrey; Pate, Russell R

2015-01-01

The purpose of this study was to determine the acute dose-response relationship of classroom exercise breaks with executive function and math performance in 9- to 12-year-old children by comparing 5-min, 10-min, or 20-min classroom exercise breaks to 10 min of sedentary classroom activity. This study used a within-subjects experimental design conducted in the spring of 2012. Ninety-six 4th- and 5th-grade students in 5 classrooms in South Carolina were randomized to receive each of 4 treatments: 5-min, 10-min, or 20-min exercise breaks or 10 min of a sedentary lesson led by research staff. Students completed the Trail-Making Test, an Operational Digit Recall test, and a math fluency test immediately before and after each condition. Planned linear contrasts were used to compare posttest scores between conditions using a repeated-measures mixed model, adjusted for gender, classroom, and the time-varying pretest scores. Potential effect modifiers were added as interaction terms. Math scores were higher after the 10-min and 20-min exercise breaks compared with the sedentary condition (d = 0.24, p = .04, and d = 0.27, p = .02, respectively), and an interaction was observed with gender, IQ, aerobic fitness, and lower engagement in some of the conditions. There were no improvements in executive function tasks. A 10-min and 20-min classroom exercise break moderately improved math performance in students compared with a seated classroom lesson.

Time dependent micromechanics in continuous graphite fiber/epoxy composites with fiber breaks

NASA Astrophysics Data System (ADS)

Zhou, Chao Hui

Time dependent micromechanics in graphite fiber/epoxy composites around fiber breaks was investigated with micro Raman spectroscopy (MRS) and two shear-lag based composite models, a multi-fiber model (VBI) and a single fiber model (SFM), which aim at predicting the strain/stress evolutions in the composite from the matrix creep behavior and fiber strength statistics. This work is motivated by the need to understand the micromechanics and predict the creep-rupture of the composites. Creep of the unfilled epoxy was characterized under different stress levels and at temperatures up to 80°C, with two power law functions, which provided the modeling parameters used as input for the composite models. Both the VBI and the SFM models showed good agreement with the experimental data obtained with MRS, when inelasticity (interfacial debonding and/or matrix yielding) was not significant. The maximum shear stress near a fiber break relaxed at t-alpha/2 (or as (1+ talpha)-1/2) and the load recovery length increased at talpha/2(or (1+ talpha)1/2) following the model predictions. When the inelastic zone became non-negligible, the viscoelastic VBI model lost its competence, while the SFM with inelasticity showed good agreement with the MRS measurements. Instead of using the real fiber spacing, an effective fiber spacing was used in model predictions, taking into account of the radial decay of the interfacial shear stress from the fiber surface. The comparisons between MRS data and the SFM showed that inelastic zone would initiate when the shear strain at the fiber end exceeds a critical value gammac which was determined to be 5% for this composite system at room temperature and possibly a smaller value at elevated temperatures. The stress concentrations in neighboring intact fibers played important roles in the subsequent fiber failure and damage growth. The VBI model predicts a constant stress concentration factor, 1.33, for the 1st nearest intact fiber, which is in good agreement with MRS measurements for most cases except for those with severely debonded interfaces. However, the VBI model usually gives a stress concentration profile narrower than the measured one due to the inelasticity near the fiber break. The low average fiber volume fraction in the model composites caused small relaxation in the stress concentration, which became more obvious at elevated temperatures, especially for large fiber spacing cases. When new break(s) occurred in the original intact neighboring fibers within an effective distance from the original break, the inelastic zones grew at a faster rate due to the strong interactions. Results on the creep-rupture of the bulk composites showed that the failure probability depends on the stress level and the loading time. The time dependent failure probability data could be fitted to a power law function, which suggested a link between the matrix creep, composite short-term strength and the composite creep-rupture.

Taste symmetry breaking with hypercubic-smeared staggered fermions

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

Bae, Taegil; Adams, David H.; Kim, Hyung-Jin

2008-05-01

We study the impact of hypercubic (HYP) smearing on the size of taste-breaking for staggered fermions, comparing to unimproved and to asqtad-improved staggered fermions. As in previous studies, we find a substantial reduction in taste-breaking compared to unimproved staggered fermions (by a factor of 4-7 on lattices with spacing a{approx_equal}0.1 fm). In addition, we observe that discretization effects of next-to-leading order in the chiral expansion (O(a{sup 2}p{sup 2})) are markedly reduced by HYP smearing. Compared to asqtad valence fermions, we find that taste-breaking in the pion spectrum is reduced by a factor of 2.5-3, down to a level comparable tomore » the expected size of generic O(a{sup 2}) effects. Our results suggest that, once one reaches a lattice spacing of a{approx_equal}0.09 fm, taste-breaking will be small enough after HYP smearing that one can use a modified power counting in which O(a{sup 2})<

High Concentrations of Organic Contaminants in Air from Ship Breaking Activities in Chittagong, Bangladesh.

PubMed

Nøst, Therese H; Halse, Anne K; Randall, Scott; Borgen, Anders R; Schlabach, Martin; Paul, Alak; Rahman, Atiqur; Breivik, Knut

2015-10-06

The beaches on the coast of Chittagong in Bangladesh are one of the most intense ship breaking areas in the world. The aim of the study was to measure the concentrations of organic contaminants in the air in the city of Chittagong, including the surrounding ship breaking areas using passive air samplers (N = 25). The compounds detected in the highest amounts were the polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs), whereas dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were several orders of magnitude lower in comparison. PCBs, PAHs, and HCB were highest at sites near the ship breaking activities, whereas DDTs and SCCPs were higher in the urban areas. Ship breaking activities likely act as atmospheric emission sources of PCBs, PAHs, and HCB, thus adding to the international emphasis on responsible recycling of ships. Concentrations of PAHs, PCBs, DDTs, HCB, and SCCPs in ambient air in Chittagong are high in comparison to those found in similar studies performed in other parts of Asia. Estimated toxic equivalent quotients indicate elevated human health risks caused by inhalation of PAHs at most sites.

Multiloop integral system test (MIST): Final report

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

Gloudemans, J.R.

1991-04-01

The Multiloop Integral System Test (MIST) is part of a multiphase program started in 1983 to address small-break loss-of-coolant accidents (SBLOCAs) specific to Babcock and Wilcox designed plants. MIST is sponsored by the US Nuclear Regulatory Commission, the Babcock Wilcox Owners Group, the Electric Power Research Institute, and Babcock and Wilcox. The unique features of the Babcock and Wilcox design, specifically the hot leg U-bends and steam generators, prevented the use of existing integral system data or existing integral facilities to address the thermal-hydraulic SBLOCA questions. MIST was specifically designed and constructed for this program, and an existing facility --more » the Once Through Integral System (OTIS) -- was also used. Data from MIST and OTIS are used to benchmark the adequacy of system codes, such as RELAP5 and TRAC, for predicting abnormal plant transients. The MIST program is reported in 11 volumes. Volumes 2 through 8 pertain to groups of Phase 3 tests by type; Volume 9 presents inter-group comparisons; Volume 10 provides comparisons between the RELAP5/MOD2 calculations and MIST observations, and Volume 11 (with addendum) presents the later Phase 4 tests. This is Volume 1 of the MIST final report, a summary of the entire MIST program. Major topics include, Test Advisory Group (TAG) issues, facility scaling and design, test matrix, observations, comparison of RELAP5 calculations to MIST observations, and MIST versus the TAG issues. MIST generated consistent integral-system data covering a wide range of transient interactions. MIST provided insight into integral system behavior and assisted the code effort. The MIST observations addressed each of the TAG issues. 11 refs., 29 figs., 9 tabs.« less

Moisture Sensitivity, Optical, Mechanical and Structural Properties of Whey Protein-Based Edible Films Incorporated with Rapeseed Oil.

PubMed

Galus, Sabina; Kadzińska, Justyna

2016-03-01

The objective of this work is to study the effect of the rapeseed oil content on the physical properties of whey protein emulsion films. For this purpose, whey protein films with the addition of 0, 1, 2 and 3% of rapeseed oil, and glycerol as a plasticizer were obtained by the casting method. Film-forming emulsions were evaluated and compared using light scattering granulometry. The Sauter mean diameters ( d 32 ) of lipid droplets in film-forming solutions showed an increasing trend when increasing the oil volume fractions. The inclusion of rapeseed oil enhanced the hydrophobic character of whey protein films, reducing moisture content and film solubility in water. All emulsified films showed high lightness ( L* ≈90). Parameter a * decreased and parameter b* and total colour difference (∆ E ) increased with the increase of the volume fractions of oil. These results were consistent with visual observations; control films were transparent and those containing oil opaque. Water vapour sorption experimental data at the full range of water activity values from 0.11 to 0.93 were well described with Peleg's equation (R 2 ≥0.99). The tensile strength, Young's modulus and elongation at break increased with the increase of rapeseed oil volume fraction, which could be explained by interactions between lipids and the protein matrix. These results revealed that rapeseed oil has enormous potential to be incorporated into whey protein to make edible film or coating for some food products. The mechanical resistance decreased with the addition of the lipids, and the opacity and soluble matter content increased.

Stormwater management criteria for on-site pollution control: a comparative assessment of international practices.

PubMed

Sage, Jérémie; Berthier, Emmanuel; Gromaire, Marie-Christine

2015-07-01

Over the last decade, a growing interest has been shown toward innovative stormwater management practices, breaking away from conventional "end of pipe" approaches (based on conveying water offsite to centralized detention facilities). Innovative strategies, referred to as sustainable urban drainage systems, low impact development (LID) or green infrastructures, advocating for management of runoff as close to its origin as possible, have therefore gained a lot of popularity among practitioners and public authorities. However, while the need for pollution control is generally well accepted, there is no wide agreement about management criteria to be given to developers. This article hence aims to compare these criteria through literature analysis of different state or local stormwater management manuals or guidelines, investigating both their suitability for pollution control and their influence on best management practices selection and design. Four categories of criteria were identified: flow-rate limitations, "water quality volumes" (to be treated), volume reduction (through infiltration or evapotranspiration), and non-hydrologic criteria (such as loads reduction targets or maximum effluent concentrations). This study suggests that hydrologic criteria based on volume reduction (rather than treatment) might generally be preferable for on-site control of diffuse stormwater pollution. Nonetheless, determination of an appropriate management approach for a specific site is generally not straightforward and presents a variety of challenges for site designers seeking to satisfy local requirements in addressing stormwater quantity and quality issues. The adoption of efficient LID solution may therefore strongly depend on the guidance given to practitioners to account for these management criteria.

Stormwater Management Criteria for On-Site Pollution Control: A Comparative Assessment of International Practices

NASA Astrophysics Data System (ADS)

Sage, Jérémie; Berthier, Emmanuel; Gromaire, Marie-Christine

2015-07-01

Over the last decade, a growing interest has been shown toward innovative stormwater management practices, breaking away from conventional "end of pipe" approaches (based on conveying water offsite to centralized detention facilities). Innovative strategies, referred to as sustainable urban drainage systems, low impact development (LID) or green infrastructures, advocating for management of runoff as close to its origin as possible, have therefore gained a lot of popularity among practitioners and public authorities. However, while the need for pollution control is generally well accepted, there is no wide agreement about management criteria to be given to developers. This article hence aims to compare these criteria through literature analysis of different state or local stormwater management manuals or guidelines, investigating both their suitability for pollution control and their influence on best management practices selection and design. Four categories of criteria were identified: flow-rate limitations, "water quality volumes" (to be treated), volume reduction (through infiltration or evapotranspiration), and non-hydrologic criteria (such as loads reduction targets or maximum effluent concentrations). This study suggests that hydrologic criteria based on volume reduction (rather than treatment) might generally be preferable for on-site control of diffuse stormwater pollution. Nonetheless, determination of an appropriate management approach for a specific site is generally not straightforward and presents a variety of challenges for site designers seeking to satisfy local requirements in addressing stormwater quantity and quality issues. The adoption of efficient LID solution may therefore strongly depend on the guidance given to practitioners to account for these management criteria.

Hydrophobic hydration and the anomalous partial molar volumes in ethanol-water mixtures

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

Tan, Ming-Liang; Te, Jerez; Cendagorta, Joseph R.

2015-02-14

The anomalous behavior in the partial molar volumes of ethanol-water mixtures at low concentrations of ethanol is studied using molecular dynamics simulations. Previous work indicates that the striking minimum in the partial molar volume of ethanol V{sub E} as a function of ethanol mole fraction X{sub E} is determined mainly by water-water interactions. These results were based on simulations that used one water model for the solute-water interactions but two different water models for the water-water interactions. This is confirmed here by using two more water models for the water-water interactions. Furthermore, the previous work indicates that the initial decreasemore » is caused by association of the hydration shells of the hydrocarbon tails, and the minimum occurs at the concentration where all of the hydration shells are touching each other. Thus, the characteristics of the hydration of the tail that cause the decrease and the features of the water models that reproduce this type of hydration are also examined here. The results show that a single-site multipole water model with a charge distribution that mimics the large quadrupole and the p-orbital type electron density out of the molecular plane has “brittle” hydration with hydrogen bonds that break as the tails touch, which reproduces the deep minimum. However, water models with more typical site representations with partial charges lead to flexible hydration that tends to stay intact, which produces a shallow minimum. Thus, brittle hydration may play an essential role in hydrophobic association in water.« less

N-flation with hierarchically light axions in string compactifications

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

Cicoli, Michele; Dutta, Koushik; Maharana, Anshuman, E-mail: mcicoli@ictp.it, E-mail: koushik.dutta@saha.ac.in, E-mail: anshumanmaharana@hri.res.in

2014-08-01

We propose a possible embedding of axionic N-flation in type IIB string compactifications where most of the Kähler moduli are stabilised by perturbative effects, and so are hierarchically heavier than the corresponding N>> 1 axions whose collective dynamics drives inflation. This is achieved in the framework of the LARGE Volume Scenario for moduli stabilisation. Our set-up can be used to realise a model of either large field inflation or quintessence, just by varying the volume of the internal space which controls the scale of the axionic potential. Both cases predict a very high scale of supersymmetry breaking. A fully explicit stringymore » embedding of N-flation would require control over dangerous back-reaction effects due to a large number of species. A viable reheating of the Standard Model degrees of freedom can be achieved after the end of inflation due to the perturbative decay of the N light axions which drive inflation.« less

Taming the runaway problem of inflationary landscapes

NASA Astrophysics Data System (ADS)

Hall, Lawrence J.; Watari, Taizan; Yanagida, T. T.

2006-05-01

A wide variety of vacua, and their cosmological realization, may provide an explanation for the apparently anthropic choices of some parameters of particle physics and cosmology. If the probability on various parameters is weighted by volume, a flat potential for slow-roll inflation is also naturally understood, since the flatter the potential the larger the volume of the subuniverse. However, such inflationary landscapes have a serious problem, predicting an environment that makes it exponentially hard for observers to exist and giving an exponentially small probability for a moderate universe like ours. A general solution to this problem is proposed, and is illustrated in the context of inflaton decay and leptogenesis, leading to an upper bound on the reheating temperature in our subuniverse. In a particular scenario of chaotic inflation and nonthermal leptogenesis, predictions can be made for the size of CP violating phases, the rate of neutrinoless double beta decay and, in the case of theories with gauge-mediated weak-scale supersymmetry, for the fundamental scale of supersymmetry breaking.

[Weak evidence concerning sedentary lifestyle and its association with cardio-metabolic illness among young people. "Junk food" and late evenings in front of the screen part of a complex connection].

PubMed

Fröberg, Andreas; Raustorp, Anders

2015-06-16

During recent decades there has been a rapidly growing interest in youths' sedentary behaviour and its association with cardio-metabolic health. Currently there is little-to-no evidence for a cross-sectional and longitudinal association between volume and pattern (bouts and breaks) of objectively measured sedentary behavior and body weight in youth. Likewise, there is little-to-no evidence for a cross-sectional association between volume and pattern of objectively measured sedentary behavior and other markers for cardio-metabolic risk in youth. However, there is sufficient evidence for a cross-sectional and longitudinal association between screen-time and body weight and blood pressure and blood lipids. Furthermore, there is evidence for a cross-sectional association between youths' screen-time and clustered metabolic risk and insulin resistance. Overall, the level of evidence was low and, therefore, caution is required when interpreting the results.

Update on Bio-Refining and Nanocellulose Composite Materials Manufacturing.

PubMed

Postek, Michael T; Poster, Dianne L

2017-01-01

Nanocellulose is a high value material that has gained increasing attention because of its high strength, stiffness, unique photonic and piezoelectric properties, high stability and uniform structure. One of the factors limiting the potential of nanocellulose and the vast array of potential new products is the ability to produce high-volume quantities of this nano-material. However, recent research has demonstrated that nanocellulose can be efficently produced in large volumes from wood at relatively low cost by the incorporation of ionizing radiation in the process stream. Ionizing radiation causes significant break down of the polysaccharides and leads to the production of potentially useful gaseous products such as H 2 and CO. Ionizing radiation processing remains an open field, ripe for innovation and application. This presentation will review the strong collaboration between the National Institute of Standards and Technology (NIST) and its academic partners pursuing the demonstration of applied ionizing radiation processing to plant materials for the manufacturing and characterization of novel nanomaterials.

Update on Bio-Refining and Nanocellulose Composite Materials Manufacturing

PubMed Central

Postek, Michael T.; Poster, Dianne L.

2017-01-01

Nanocellulose is a high value material that has gained increasing attention because of its high strength, stiffness, unique photonic and piezoelectric properties, high stability and uniform structure. One of the factors limiting the potential of nanocellulose and the vast array of potential new products is the ability to produce high-volume quantities of this nano-material. However, recent research has demonstrated that nanocellulose can be efficently produced in large volumes from wood at relatively low cost by the incorporation of ionizing radiation in the process stream. Ionizing radiation causes significant break down of the polysaccharides and leads to the production of potentially useful gaseous products such as H2 and CO. Ionizing radiation processing remains an open field, ripe for innovation and application. This presentation will review the strong collaboration between the National Institute of Standards and Technology (NIST) and its academic partners pursuing the demonstration of applied ionizing radiation processing to plant materials for the manufacturing and characterization of novel nanomaterials. PMID:29225398

Update on bio-refining and nanocellulose composite materials manufacturing

NASA Astrophysics Data System (ADS)

Postek, Michael T.; Poster, Dianne L.

2017-08-01

Nanocellulose is a high value material that has gained increasing attention because of its high strength, stiffness, unique photonic and piezoelectric properties, high stability and uniform structure. One of the factors limiting the potential of nanocellulose and the vast array of potential new products is the ability to produce high-volume quantities of this nano-material. However, recent research has demonstrated that nanocellulose can be efficently produced in large volumes from wood at relatively low cost by the incorporation of ionizing radiation in the process stream. Ionizing radiation causes significant break down of the polysaccharides and leads to the production of potentially useful gaseous products such as H2 and CO. Ionizing radiation processing remains an open field, ripe for innovation and application. This presentation will review the strong collaboration between the National Institute of Standards and Technology (NIST) and its academic partners pursuing the demonstration of applied ionizing radiation processing to plant materials for the manufacturing and characterization of novel nanomaterials.

Breathing silicon anodes for durable high-power operations

NASA Astrophysics Data System (ADS)

Hwang, Chihyun; Joo, Sehun; Kang, Na-Ri; Lee, Ungju; Kim, Tae-Hee; Jeon, Yuju; Kim, Jieun; Kim, Young-Jin; Kim, Ju-Young; Kwak, Sang-Kyu; Song, Hyun-Kon

2015-09-01

Silicon anode materials have been developed to achieve high capacity lithium ion batteries for operating smart phones and driving electric vehicles for longer time. Serious volume expansion induced by lithiation, which is the main drawback of silicon, has been challenged by multi-faceted approaches. Mechanically rigid and stiff polymers (e.g. alginate and carboxymethyl cellulose) were considered as the good choices of binders for silicon because they grab silicon particles in a tight and rigid way so that pulverization and then break-away of the active mass from electric pathways are suppressed. Contrary to the public wisdom, in this work, we demonstrate that electrochemical performances are secured better by letting silicon electrodes breathe in and out lithium ions with volume change rather than by fixing their dimensions. The breathing electrodes were achieved by using a polysaccharide (pullulan), the conformation of which is modulated from chair to boat during elongation. The conformational transition of pullulan was originated from its α glycosidic linkages while the conventional rigid polysaccharide binders have β linkages.

Employee Perception of Breastfeeding-Friendly Support and Benefits of Breastfeeding as a Predictor of Intention to Use Breast-Pumping Breaks After Returning to Work Among Employed Mothers

PubMed Central

2014-01-01

Abstract Background: Although increasing numbers of large companies are complying with demands for a breastfeeding-friendly workplace by providing lactation rooms and breast-pumping breaks, the effectiveness for intention to use breast-pumping breaks to express breast milk among employed mothers is uncertain. To explore the impact of employees' perceived breastfeeding support from the workplace and the benefits of breastfeeding on a woman's intention to use breast-pumping breaks after returning to work, we conducted a survey at a female labor-intensive electronics manufacturer in Taiwan. Subjects and Methods: A structured questionnaire survey was administered to 715 working mothers employed in an electronics manufacturing plant in Tainan Science Park in Southern Taiwan. Questionnaire content included female employee demographics, employment characteristics, and breastfeeding behavior after returning to work, as well as employees' perception of breastfeeding-friendly support and awareness of the benefits of breastfeeding when raising their most recently born child. Results: Higher education (odds ratio [OR] 2.33), non–clean room worksite (OR 1.51), awareness of breast-pumping breaks (OR 4.70), encouragement by colleagues to use breast-pumping breaks (OR 1.76), and greater awareness of the benefits of breastfeeding (OR 1.08) were significant predictors of the use of breast-pumping breaks after returning to work, whereas the perception of inefficiency when using breast-pumping breaks reduced an employed mother's intention to use breast-pumping breaks (OR 0.55). Conclusions: This study finds an association between an appreciation of the benefits provided by the employer and the likelihood of increased usage of breastfeeding breaks. Workplaces and employers can help employed mothers to understand the benefits of breastfeeding, which may increase the intention of the mother to take breast-pumping breaks after returning to work. PMID:24304034

Propagation and Breaking at High Altitudes of Gravity Waves Excited by Tropospheric Forcing

NASA Technical Reports Server (NTRS)

Prusa, Joseph M.; Smolarkiewicz, Piotr K.; Garcia, Rolando R.

1996-01-01

An anelastic approximation is used with a time-variable coordinate transformation to formulate a two-dimensional numerical model that describes the evolution of gravity waves. The model is solved using a semi-Lagrangian method with monotone (nonoscillatory) interpolation of all advected fields. The time-variable transformation is used to generate disturbances at the lower boundary that approximate the effect of a traveling line of thunderstorms (a squall line) or of flow over a broad topographic obstacle. The vertical propagation and breaking of the gravity wave field (under conditions typical of summer solstice) is illustrated for each of these cases. It is shown that the wave field at high altitudes is dominated by a single horizontal wavelength; which is not always related simply to the horizontal dimension of the source. The morphology of wave breaking depends on the horizontal wavelength; for sufficiently short waves, breaking involves roughly one half of the wavelength. In common with other studies, it is found that the breaking waves undergo "self-acceleration," such that the zonal-mean intrinsic frequency remains approximately constant in spite of large changes in the background wind. It is also shown that many of the features obtained in the calculations can be understood in terms of linear wave theory. In particular, linear theory provides insights into the wavelength of the waves that break at high altitudes, the onset and evolution of breaking. the horizontal extent of the breaking region and its position relative to the forcing, and the minimum and maximum altitudes where breaking occurs. Wave breaking ceases at the altitude where the background dissipation rate (which in our model is a proxy for molecular diffusion) becomes greater than the rate of dissipation due to wave breaking, This altitude, in effect, the model turbopause, is shown to depend on a relatively small number of parameters that characterize the waves and the background state.

Give me a better break: Choosing workday break activities to maximize resource recovery.

PubMed

Hunter, Emily M; Wu, Cindy

2016-02-01

Surprisingly little research investigates employee breaks at work, and even less research provides prescriptive suggestions for better workday breaks in terms of when, where, and how break activities are most beneficial. Based on the effort-recovery model and using experience sampling methodology, we examined the characteristics of employee workday breaks with 95 employees across 5 workdays. In addition, we examined resources as a mediator between break characteristics and well-being. Multilevel analysis results indicated that activities that were preferred and earlier in the work shift related to more resource recovery following the break. We also found that resources mediated the influence of preferred break activities and time of break on health symptoms and that resource recovery benefited person-level outcomes of emotional exhaustion, job satisfaction, and organizational citizenship behavior. Finally, break length interacted with the number of breaks per day such that longer breaks and frequent short breaks were associated with more resources than infrequent short breaks. (c) 2016 APA, all rights reserved).

Development of Carbon-14 Waste Destruction and Recovery System Using AC Plasma Torch Technology Final Report CRADA No. TC02108.0

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

Althouse, P.; McKannay, R. H.

This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and ISOFLEX USA (ISOFLEX), to 1) develop and test a prototype waste destruction system ("System") using AC plasma torch technology to break down and drastically reduce the volume of Carbon-14 (C-14) contaminated medical laboratory wastes while satisfying all environmental regulations, and 2) develop and demonstrate methods for recovering 99%+ of the carbon including the C-14 allowing for possible re-use as a tagging and labeling tool in the biomedical industry.

An exact solution for ideal dam-break floods on steep slopes

USGS Publications Warehouse

Ancey, C.; Iverson, R.M.; Rentschler, M.; Denlinger, R.P.

2008-01-01

The shallow-water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of readily evaluated integrals. Although the solution treats an idealized case never strictly realized in nature, it is uniquely well-suited for testing the robustness and accuracy of numerical models used to model shallow-water flows on steep slopes. Copyright 2008 by the American Geophysical Union.

Coupled-channel approach to strangeness S = -2 baryon-bayron interactions in lattice QCD

NASA Astrophysics Data System (ADS)

Sasaki, Kenji; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko

2015-11-01

Baryon-baryon interactions with strangeness S=-2 with flavor SU(3) breaking are calculated for the first time by using the HAL QCD method extended to the coupled-channel system in lattice QCD. The potential matrices are extracted from the Nambu-Bethe-Salpeter wave functions obtained by the 2+1-flavor gauge configurations of the CP-PACS/JLQCD Collaborations with a physical volume of (1.93 fm)^3 and with m_{π }/m_K=0.96, 0.90, 0.86. The spatial structure and the quark mass dependence of the potential matrix in the baryon basis and in the SU(3) basis are investigated.

Symmetry Violation in Hadron Physics

NASA Astrophysics Data System (ADS)

Gell-Mann, Murray

1982-01-01

The following sections are included: * INTRODUCTION * SU(3) × SU(3) SYMMETRY * VIOLATION OF SU(3) × SU(3) IN STRONG INTERACTIONS * POSSIBLE CONNECTIONS OF STRONG VIOLATION WITH WEAK AND ELECTROMAGNETIC EFFECTS * SCALE INVARIANCE AND THE DILATION OPERATOR * THE BREAKING OF SCALE INVARIANCE * RELATION BETWEEN VIOLATIONS OF SCALE INVARIANCE AND OF SU(3) × SU(3) * REFERENCES *Note: Much of the work presented in the next two sections was done this summer in collaboration with Lowell Brown. It is based partly on the pioneering research of Kastrup, Mack, Wess, Kenneth Wilson, and others. *In this section and the next, our particle states are normalized to one particle per unit volume.

A macroscopic and microscopic study of radon exposure using Geant4 and MCNPX to estimate dose rates and DNA damage

NASA Astrophysics Data System (ADS)

van den Akker, Mary Evelyn

Radon is considered the second-leading cause of lung cancer after smoking. Epidemiological studies have been conducted in miner cohorts as well as general populations to estimate the risks associated with high and low dose exposures. There are problems with extrapolating risk estimates to low dose exposures, mainly that the dose-response curve at low doses is not well understood. Calculated dosimetric quantities give average energy depositions in an organ or a whole body, but morphological features of an individual can affect these values. As opposed to human phantom models, Computed Tomography (CT) scans provide unique, patient-specific geometries that are valuable in modeling the radiological effects of the short-lived radon progeny sources. Monte Carlo particle transport code Geant4 was used with the CT scan data to model radon inhalation in the main bronchial bifurcation. The equivalent dose rates are near the lower bounds of estimates found in the literature, depending on source volume. To complement the macroscopic study, simulations were run in a small tissue volume in Geant4-DNA toolkit. As an expansion of Geant4 meant to simulate direct physical interactions at the cellular level, the particle track structure of the radon progeny alphas can be analyzed to estimate the damage that can occur in sensitive cellular structures like the DNA molecule. These estimates of DNA double strand breaks are lower than those found in Geant4-DNA studies. Further refinements of the microscopic model are at the cutting edge of nanodosimetry research.

Formulating a subgrid-scale breakup model for microbubble generation from interfacial collisions

NASA Astrophysics Data System (ADS)

Chan, Wai Hong Ronald; Mirjalili, Shahab; Urzay, Javier; Mani, Ali; Moin, Parviz

2017-11-01

Multiphase flows often involve impact events that engender important effects like the generation of a myriad of tiny bubbles that are subsequently transported in large liquid bodies. These impact events are created by large-scale phenomena like breaking waves on ocean surfaces, and often involve the relative approach of liquid surfaces. This relative motion generates continuously shrinking length scales as the entrapped gas layer thins and eventually breaks up into microbubbles. The treatment of this disparity in length scales is computationally challenging. In this presentation, a framework is presented that addresses a subgrid-scale (SGS) model aimed at capturing the process of microbubble generation. This work sets up the components in an overarching volume-of-fluid (VoF) toolset and investigates the analytical foundations of an SGS model for describing the breakup of a thin air film trapped between two approaching water bodies in a physical regime corresponding to Mesler entrainment. Constituents of the SGS model, such as the identification of impact events and the accurate computation of the local characteristic curvature in a VoF-based architecture, and the treatment of the air layer breakup, are discussed and illustrated in simplified scenarios. Supported by Office of Naval Research (ONR)/A*STAR (Singapore).

Correlation between refraction level and retinal breaks in myopic eye.

PubMed

Alimanović-Halilović, Emina

2008-11-01

In this study we analyzed 180 myopic eyes in order to determine the refraction that is "critical" for the occurrence of retinal breaks as a main cause of retinal detachment. Detachment of retina involves separation of the neurosensory retina from the pigmented epithelium with the severe impairment of vision. After the focused ophthalmological assessment, determination of objective refraction, indirect binocular ophthalmoscopy, we compared the diagnosed retinal breaks according to the shape with the refraction. All the examined eyes were divided into six groups according to the axis length. Mean age of our patients was between 48,43 and 51,60 years with SD ranging from 13,88 to 18,45. The age differences among the groups were not statistically significant. This study included 102 (56,7%) male and 78 (43,3%) female patients and no statistically significant differences between genders was found regarding the occurrence of retinal breaks compared to refraction. The most dominant ruptures were the round ones (28,2%), followed by oval (25%), the category of multiple small holes (19,2%), horseshoe shaped (15,3%), and finally holes with operculum. In cases with myopic refraction ranging between 3,50 and 7,49 dsph, the frequency of retinal breaks statistically significantly differs from all other analyzed refractions. Also, there is positive correlation between the above mentioned myopic refraction and the frequency of retinal breaks. In order to prevent retinal detachment in a myopic eye, we suggest further thorough examinations of the eye fundus in patients with the above mentioned myopia. Diagnosing retinal breaks involves the application of adequate therapy: laser photocoagulation, cryotherapy, sclera buckling and pneumatic retinopexy.

Homework particularities for small school children.

PubMed

Beiusanu, Corina; Vlaicu, Brigitha

2013-01-01

The present study was centered on the particularities of the duration of preparing homework, taking breaks during homework preparation, and the way the breaks should take place for small school children. The study has been done on a sample of 235 small school children from Oradea, 114 boys and 121 girls, between the ages 7 and 10 years old, using an anonymous questioner, with 41 items, which investigates the lifestyle of the small school children. The duration of homework preparation it is significantly more reduced for the school children in 1st grade in comparison with the ones in 3 grade (p < 0.001); for school children in 2nd grade compared to the ones in 3rd (p < 0.001) and for school children in 3rd grade compared to the ones in 4th grade. A percentage of 93% of children prepare their homework after lunch. Half of the children from grades I-IV prepare their homework with no break. A very small number of children spend their homework break time in a healthy manner, while the rest prefer to play computer games (46.95%) or to watch television (46.08%). More than half of the schoolchildren need 1-2 hours at home to prepare their homework. Most of the school children prepare their homework after lunch, in an optimal interval of time. Half of the questioned children prepare their homework with no break. Those who are taking breaks prefer activities which get the children even more tired, therefore being non-hygienic methods of spending homework breaks.

Perceptions of Rule-Breaking Related to Marine Ecosystem Health

PubMed Central

Slater, Matthew J.; Mgaya, Yunus D.; Stead, Selina M.

2014-01-01

Finding effective solutions to manage marine resources is high on political and conservation agendas worldwide. This is made more urgent by the rate of increase in the human population and concomitant resource pressures in coastal areas. This paper links empirical socio-economic data about perceptions of marine resource health to the breaking of marine management rules, using fisheries as a case study. The relationship between perceived rule-breaking (non-compliance with regulations controlling fishing) and perceived health of inshore marine environments was investigated through face-to-face interviews with 299 heads of households in three Tanzanian coastal communities in November and December 2011. Awareness of rules controlling fishing activity was high among all respondents. Fishers were able to describe more specific rules controlling fishing practices than non-fishers (t = 3.5, df = 297, p<0.01). Perceived breaking of fishing regulations was reported by nearly half of all respondents, saying “some” (32% of responses) or “most” (15% of responses) people break fishing rules. Ordinal regression modelling revealed a significant linkage (z = −3.44, p<0.001) in the relationship between respondents' perceptions of deteriorating marine health and their perception of increased rule-breaking. In this paper, inferences from an empirical study are used to identify and argue the potential for using perceptions of ecosystem health and level of rule-breaking as a means to guide management measures. When considering different management options (e.g. Marine Protected Areas), policy makers are advised to take account of and utilise likely egoistic or altruistic decision-making factors used by fishers to determine their marine activities. PMID:24586558

Perceptions of rule-breaking related to marine ecosystem health.

PubMed

Slater, Matthew J; Mgaya, Yunus D; Stead, Selina M

2014-01-01

Finding effective solutions to manage marine resources is high on political and conservation agendas worldwide. This is made more urgent by the rate of increase in the human population and concomitant resource pressures in coastal areas. This paper links empirical socio-economic data about perceptions of marine resource health to the breaking of marine management rules, using fisheries as a case study. The relationship between perceived rule-breaking (non-compliance with regulations controlling fishing) and perceived health of inshore marine environments was investigated through face-to-face interviews with 299 heads of households in three Tanzanian coastal communities in November and December 2011. Awareness of rules controlling fishing activity was high among all respondents. Fishers were able to describe more specific rules controlling fishing practices than non-fishers (t = 3.5, df = 297, p<0.01). Perceived breaking of fishing regulations was reported by nearly half of all respondents, saying "some" (32% of responses) or "most" (15% of responses) people break fishing rules. Ordinal regression modelling revealed a significant linkage (z= -3.44, p<0.001) in the relationship between respondents' perceptions of deteriorating marine health and their perception of increased rule-breaking. In this paper, inferences from an empirical study are used to identify and argue the potential for using perceptions of ecosystem health and level of rule-breaking as a means to guide management measures. When considering different management options (e.g. Marine Protected Areas), policy makers are advised to take account of and utilise likely egoistic or altruistic decision-making factors used by fishers to determine their marine activities.

Spring Break versus Spring Broken: Predictive Utility of Spring Break Alcohol Intentions and Willingness at Varying Levels of Extremity

PubMed Central

Litt, Dana M.; Lewis, Melissa A.; Patrick, Megan E.; Rodriguez, Lindsey; Neighbors, Clayton; Kaysen, Debra L.

2013-01-01

Objective Within the domain of risk-related behavior, many times the decision to engage is not a product of premeditation or intention. The Prototype Willingness model was created to capture and explain the unintended element of risk behavior. The present study aimed to evaluate the importance of willingness versus intention, two important constructs within the Prototype Willingness model, in relation to Spring Break drinking behavior when assessed at both high and low extremities. Method College undergraduates (N = 275) completed questionnaires prior to Spring Break regarding their anticipated Spring Break activities. Willingness and intention were assessed for different levels of risk. Specifically, participants indicated the extent to which they intended to (a) get drunk and (b) drink enough to black out or pass out; and the extent to which they were willing to (a) get drunk and (b) drink enough to black out or pass out. When classes resumed following Spring Break, the students indicated the extent to which they actually (a) got drunk and (b) drank enough to black out or pass out. Results Results demonstrated that when the health-related risk was lower (i.e., getting drunk), intention was a stronger predictor of behavior than was willingness. However, as the level of risk increased (i.e., getting drunk enough to black out or pass out), willingness more strongly predicted behavior. Conclusion The present study suggests that willingness and intentions differentially predict Spring Break alcohol-related behavior depending on the extremity of behavior in question. Implications regarding alcohol interventions are discussed. PMID:23404667

Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar

NASA Astrophysics Data System (ADS)

van der A, Dominic A.; van der Zanden, Joep; O'Donoghue, Tom; Hurther, David; Cáceres, Iván.; McLelland, Stuart J.; Ribberink, Jan S.

2017-04-01

A large-scale wave flume experiment has been carried out involving a T = 4 s regular wave with H = 0.85 m wave height plunging over a fixed barred beach profile. Velocity profiles were measured at 12 locations along the breaker bar using LDA and ADV. A strong undertow is generated reaching magnitudes of 0.8 m/s on the shoreward side of the breaker bar. A circulation pattern occurs between the breaking area and the inner surf zone. Time-averaged turbulent kinetic energy (TKE) is largest in the breaking area on the shoreward side of the bar where the plunging jet penetrates the water column. At this location, and on the bar crest, TKE generated at the water surface in the breaking process reaches the bottom boundary layer. In the breaking area, TKE does not reduce to zero within a wave cycle which leads to a high level of "residual" turbulence and therefore lower temporal variation in TKE compared to previous studies of breaking waves on plane beach slopes. It is argued that this residual turbulence results from the breaker bar-trough geometry, which enables larger length scales and time scales of breaking-generated vortices and which enhances turbulence production within the water column compared to plane beaches. Transport of TKE is dominated by the undertow-related flux, whereas the wave-related and turbulent fluxes are approximately an order of magnitude smaller. Turbulence production and dissipation are largest in the breaker zone and of similar magnitude, but in the shoaling zone and inner surf zone production is negligible and dissipation dominates.

Breaking bad news: A communication competency for ophthalmology training programs.

PubMed

Hilkert, Sarah M; Cebulla, Colleen M; Jain, Shelly Gupta; Pfeil, Sheryl A; Benes, Susan C; Robbins, Shira L

As the ophthalmology accreditation system undergoes major changes, training programs must evaluate residents in the 6 core competencies, including appropriately communicating bad news. Although the literature is replete with recommendations for breaking bad news across various non-ophthalmology specialties, no formal training programs exist for ophthalmology. There are many valuable lessons to be learned from our colleagues regarding this important skill. We examine the historic basis for breaking bad news, explore current recommendations among other specialties, and then evaluate a pilot study in breaking bad news for ophthalmology residents. The results of this study are limited by a small number of residents at a single academic center. Future studies from multiple training programs should be conducted to further evaluate the need and efficacy of formal communication skills training in this area, as well as the generalizability of our pilot training program. If validated, this work could serve as a template for future ophthalmology resident training and evaluation in this core competency. Copyright © 2016 Elsevier Inc. All rights reserved.

Breaking bad news: a communication competency for ophthalmology training programs

PubMed Central

Hilkert, Sarah M.; Cebulla, Colleen M.; Jain, Shelly Gupta; Pfeil, Sheryl A.; Benes, Susan C.; Robbins, Shira L.

2016-01-01

As the ophthalmology accreditation system undergoes major changes, training programs must evaluate residents in the 6 core competencies, including appropriately communicating bad news. Although the literature is replete with recommendations for breaking bad news across various non-ophthalmology specialties, no formal training programs exist for ophthalmology. There are many valuable lessons to be learned from our non-ophthalmology colleagues regarding this important skill. We examine the historic basis for breaking bad news, explores current recommendations among other specialties, and then evaluate a pilot study to teach breaking bad news to ophthalmology residents. The results of this study are limited by a small number of residents at a single academic center. Future studies from multiple training programs should be conducted to further evaluate the need and efficacy of formal communication skills training in this area, as well as the generalizability of our pilot training program. If validated, this work could serve as a template for future ophthalmology resident training and evaluation in this core competency. PMID:27134009

Validity of two wearable monitors to estimate breaks from sedentary time

PubMed Central

Lyden, Kate; Kozey-Keadle, Sarah L.; Staudenmayer, John W.; Freedson, Patty S.

2012-01-01

Investigations employing wearable monitors have begun to examine how sedentary time behaviors influence health. Purpose To demonstrate the utility of a measure of sedentary behavior and to validate the activPAL and ActiGraph GT3X for estimating measures of sedentary behavior: absolute number of breaks and break-rate. Methods Thirteen participants completed two, 10-hour conditions. During the baseline condition, participants performed normal daily activity and during the treatment condition, participants were asked to reduce and break-up their sedentary time. In each condition, participants wore two ActiGraph GT3X monitors and one activPAL. The ActiGraph was tested using the low frequency extension filter (AG-LFE) and the normal filter (AG-Norm). For both ActiGraph monitors two count cut-points to estimate sedentary time were examined: 100 and 150 counts∙min−1. Direct observation served as the criterion measure of total sedentary time, absolute number of breaks from sedentary time and break-rate (number of breaks per sedentary hour [brks.sed-hr−1]). Results Break-rate was the only metric sensitive to changes in behavior between baseline (5.1 [3.3 to 6.8] brks.sed-hr−1) and treatment conditions (7.3 [4.7 to 9.8] brks.sed-hr−1) (mean [95% CI]). The activPAL produced valid estimates of all sedentary behavior measures and was sensitive to changes in break-rate between conditions (baseline: 5.1 [2.8 to 7.1] brks.sed-hr−1, treatment: 8.0 [5.8 to 10.2] brks.sed-hr−1). In general, the AG-LFE and AG-Norm were not accurate in estimating break-rate or absolute number of breaks and were not sensitive to changes between conditions. Conclusion This study demonstrates the utility of expressing breaks from sedentary time as a rate per sedentary hour, a metric specifically relevant to free-living behavior, and provides further evidence that the activPAL is a valid tool to measure components of sedentary behavior in free-living environments. PMID:22648343

Effect of vacuum arc cathode spot distribution on breaking capacity of the arc-extinguishing chamber

NASA Astrophysics Data System (ADS)

Ding, Can; Yuan, Zhao; He, Junjia

2017-10-01

A DC circuit breaker performs a key function in breaking an intermediate-frequency (IF) current since breaking a pure IF current is equivalent to breaking a very small DC with a reverse IF current. In this study, it is found that cathode spots show a ring-shaped distribution at 2000 Hz. An arc with an uneven distribution of cathode spots has been simulated. The simulation results show that the distribution of cathode spots significantly affect the microparameter distribution of arc plasma. The current distribution on the anode side differs from that on the cathode side under the total radial electric field. Specifically, the anode current distribution is both uneven and concentrated. The applied axial magnetic field, which cannot reduce the concentrated anode current distribution effectively, might increase the concentration of the anode current. Finally, the uneven distribution of cathode spots reduces the breaking capacity of the arc-extinguishing chamber.

[Breaking bad news in oncology: the Belgian experience].

PubMed

Delevallez, F; Lienard, A; Gibon, A-S; Razavi, D

2014-10-01

Breaking bad news is a complex and frequent clinical task for physicians working in oncology. It can have a negative impact on patients and their relatives who are often present during breaking bad news consultations. Many factors influence how the delivery of bad news will be experienced especially the communication skills used by physicians. A three-phase process (post-delivery phase, delivery phase, pre-delivery phase) has been developed to help physician to handle this task more effectively. Communication skills and specific breaking bad news training programs are both necessary and effective. A recent study conducted in Belgium has shown their impact on the time allocated to each of the three phases of this process, on the communication skills used, on the inclusion of the relative in the consultation and on physicians' physiological arousal. These results underscore the importance of promoting intensive communication skills and breaking bad news training programs for health care professionals.

Symmetry breaking and the geometry of reduced density matrices

NASA Astrophysics Data System (ADS)

Zauner, V.; Draxler, D.; Vanderstraeten, L.; Haegeman, J.; Verstraete, F.

2016-11-01

The concept of symmetry breaking and the emergence of corresponding local order parameters constitute the pillars of modern day many body physics. We demonstrate that the existence of symmetry breaking is a consequence of the geometric structure of the convex set of reduced density matrices of all possible many body wavefunctions. The surfaces of these convex bodies exhibit non-analyticities, which signal the emergence of symmetry breaking and of an associated order parameter and also show different characteristics for different types of phase transitions. We illustrate this with three paradigmatic examples of many body systems exhibiting symmetry breaking: the quantum Ising model, the classical q-state Potts model in two-dimensions at finite temperature and the ideal Bose gas in three-dimensions at finite temperature. This state based viewpoint on phase transitions provides a unique novel tool for studying exotic many body phenomena in quantum and classical systems.

Goldstone mode and pair-breaking excitations in atomic Fermi superfluids

NASA Astrophysics Data System (ADS)

Hoinka, Sascha; Dyke, Paul; Lingham, Marcus G.; Kinnunen, Jami J.; Bruun, Georg M.; Vale, Chris J.

2017-10-01

Spontaneous symmetry breaking is a central paradigm of elementary particle physics, magnetism, superfluidity and superconductivity. According to Goldstone's theorem, phase transitions that break continuous symmetries lead to the existence of gapless excitations in the long-wavelength limit. These Goldstone modes can become the dominant low-energy excitation, showing that symmetry breaking has a profound impact on the physical properties of matter. Here, we present a comprehensive study of the elementary excitations in a homogeneous strongly interacting Fermi gas through the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a Bose-Einstein condensate (BEC) of molecules using two-photon Bragg spectroscopy. The spectra exhibit a discrete Goldstone mode, associated with the broken-symmetry superfluid phase, as well as pair-breaking single-particle excitations. Our techniques yield a direct determination of the superfluid pairing gap and speed of sound in close agreement with strong-coupling theories.

The bending strength of tablets with a breaking line--Comparison of the results of an elastic and a "brittle cracking" finite element model with experimental findings.

PubMed

Podczeck, Fridrun; Newton, J Michael; Fromme, Paul

2015-11-10

The aim of this work was to ascertain the influence of the position of the breaking line of bevel-edged tablets in a three-point bending test. Two different brands of commercially available, flat-round, bevel-edged tablets with a single central breaking line were studied. Breaking line positions tested, relative to the upper loading roll, were 0°, 22.5°, 45°, 67.5° and 90°. The breaking line faced either up- or downwards during the test. The practical results were compared with FEM results simulating similar test configurations. Tablets failed mainly across the failure plane, resulting in two tablet halves. An exception to this was found for tablets where the breaking line faced down and was positioned at an angle of 22.5° relative to the loading plane. Here the crack followed the breaking line in the centre of the tablets and only diverged towards the loading plane position at the edges of the tablets. The breaking line facing upwards resulted in a significantly higher tensile strength of the tablets compared to it facing downwards. However, with one exception, the orientation of the breaking line relative to the loading plane appeared not to affect the tensile strength values. A fully elastic FEM model indicated that both the position of the breaking line relative to the loading plane and as to whether the breaking line faced up- or downwards during the bending test would result in considerably different failure loads during practical experiments. The results also suggested that regardless of the breaking line position, when it is facing down crack propagation should start at the outer edges propagating towards the midpoint of the discs until failure occurs. Failure should hence always result in equal tablet halves, whereby the failure plane should coincide with the loading plane. Neither predictions fully reflected the practical behaviour of the tablets. Using a brittle cracking FEM model significantly larger tensile stresses for tablets with the breaking line positioned downwards at 0° or 22.5° relative to the loading plane were still predicted, but the differences between model and experimental values was greatly reduced. The remaining differences are more likely due to the inadequacy of the equation available to calculate the experimental tensile strength values. This equation cannot account for the presence of a breaking line and overestimates the thickness of the loading plane by the depth of the breaking line when in 0° or 22.5° position. If the depth of the breaking line is taken into account, the model predictions and the experimental findings are comparable. Also, in the brittle cracking FEM simulations the predicted crack propagation patterns were similar to those found in the experiments, and the model stress distributions across the lower surfaces were much more homogeneous and streamlined parallel to the loading plane. The brittle cracking model hence reflected the practicalities of the bending test more closely. The findings suggested that with the breaking line facing down fracture should always start in the centre of a tablet at its lower surface, initiated by the breaking line. Due to simultaneous development of larger stresses along the y-axis the tablet should still break into two equal halves along the loading plane, unless the position of the breaking line relative to the loading plane was 22.5°. In this case the tablet would fail by a mixed process, whereby failure would occur mainly along the breaking line, but due to simultaneous crack formation at the lower surface close to the bevel edge parallel to the loading plane the final breaking pattern would deviate from the breaking line about half-way from its centre, as seen in the practical experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

Web-based intervention to change perceived norms of college student alcohol use and sexual behavior on spring break.

PubMed

Patrick, Megan E; Lee, Christine M; Neighbors, Clayton

2014-03-01

The purpose of the present study was to evaluate an adapted web-based multi-component personalized feedback intervention to reduce college student alcohol use and risky sexual behavior during Spring Break. This is one of the first interventions focused on Spring Break alcohol use and related sexual behavior. Personalized feedback intervention components addressed intentions, expected consequences, norms, motivations, protective behavioral strategies, and pacts with friends. Participants were college students (N=263; 55% women) between the ages of 18 and 21 who planned to go on a Spring Break trip with their friends. Effects were not significant in reducing alcohol use or sexual behavior during Spring Break or some of the proposed intervention mechanisms. However, consistent results showed that the intervention succeeded in reducing perceived social norms for Spring Break drinking and sexual behavior. Findings suggest that changing norms alone is not sufficient for changing risk behavior during this event and alternative strategies are needed to impact other putative mediators. Copyright © 2013 Elsevier Ltd. All rights reserved.

Color Profile Trends of Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Herrmann, Kimberly A.; LITTLE THINGS Team

2012-01-01

Radial stellar surface brightness profiles of spiral galaxies can be classified into three types: (I) single exponential, (II) truncated: the light falls off with one exponential out to a break radius and then falls off more steeply, and (III) anti-truncated: the light falls off with one exponential out to a break radius and then falls off less steeply. Stellar surface brightness profile breaks are also found in dwarf disk galaxies, but with an additional category: (FI) flat-inside: the light is roughly constant or increasing and then falls off beyond a break. Additionally, Bakos, Trujillo, & Pohlen (2008) showed that for spirals, each profile type has a characteristic color trend with respect to the break location. Furthermore, color trends reveal information about possible stellar population changes at the breaks. Here we show color trends for the four profile types from a large multi-wavelength photometric study of dwarf disk galaxies (the 141 dwarf parent sample of the LITTLE THINGS galaxies). We explore the similarities and differences between spirals and dwarfs and also between different colors. We gratefully acknowledge funding for this research from the National Science Foundation (AST-0707563).

Analysis of unrejoined chromosomal breakage in human fibroblast cells exposed to low- and high-LET radiation

NASA Technical Reports Server (NTRS)

Wu, Honglu; Furusawa, Yoshiya; George, Kerry; Kawata, Tetsuya; Cucinotta, Francis A.

2002-01-01

Reported studies of DNA breakage induced by radiation of various qualities have generally shown a higher fraction of unrejoined residual breaks after high-LET exposure. This observation is supported by the argument that high-LET radiation induced DNA breaks that are more complex in nature and, thus, less likely to be repaired. In most cases the doses used in these studies were very high. We have studied unrejoined chromosome breaks by analyzing chromosome aberrations using a fluorescence in situ hybridization (FISH) technique with a combination of whole chromosome specific probes and probes specific for the telomere region of the chromosomes. Confluent human fibroblast cells (AG1522) were irradiated with gamma rays, 490 MeV/nucleon Si, or with Fe ions at either 200 and 500 MeV/nucleon, and were allowed to repair at 37 degrees C for 24 hours after exposure. A chemically induced premature chromosome condensation (PCC) technique was used to condense chromosomes in the G2 phase of the cell cycle. Results showed that the frequency of unrejoined chromosome breaks was higher after high-LET radiation, and the ratio of unrejoined to misrejoined chromosome breaks increased steadily with LET up a peak value at 440 keV/microm.

Concerns about losing control when breaking bad news to terminally ill patients with cancer: physicians' perspective.

PubMed

Friedrichsen, Maria; Milberg, Anna

2006-06-01

To study and explore problems perceived by physicians when breaking bad news to advanced cancer patients about discontinuing or not offering tumor-specific treatment due to incurable cancer. A qualitative phenomenographic interview study. The county of Ostergötland in Sweden. Thirty physicians with different demographic characteristics. According to the physicians' answers breaking bad news was perceived as involving a risk of losing control in different ways, regarding emotions, oneself, confidence, professionalism and patient trust. Four different main categories described as problems were identified; perceptions focusing on existential thoughts, relationships, knowledge, and perceptions related to time and environmental disturbances. Physicians perceived that breaking bad news to dying patients with cancer involved a risk of losing control. Existential thoughts and a lack of knowledge contribute to this risk. Theoretical education in existentiality/spirituality and clinical practice in a palliative context may help maintaining control.

Quantum chaos and breaking of all anti-unitary symmetries in Rydberg excitons.

PubMed

Aßmann, Marc; Thewes, Johannes; Fröhlich, Dietmar; Bayer, Manfred

2016-07-01

Symmetries are the underlying principles of fundamental interactions in nature. Chaos in a quantum system may emerge from breaking these symmetries. Compared to vacuum, crystals are attractive for studying quantum chaos, as they not only break spatial isotropy, but also lead to novel quasiparticles with modified interactions. Here we study yellow Rydberg excitons in cuprous oxide which couple strongly to the vacuum light field and interact significantly with crystal phonons, leading to inversion symmetry breaking. In a magnetic field, time-reversal symmetry is also broken and the exciton states show a complex splitting pattern, resulting in quadratic level repulsion for small splittings. In contrast to atomic chaotic systems in a magnetic field, which show only a linear level repulsion, this is a signature of a system where all anti-unitary symmetries are broken simultaneously. This behaviour can otherwise be found only for the electro-weak interaction or engineered billiards.

U(1) mediation of flux supersymmetry breaking

NASA Astrophysics Data System (ADS)

Grimm, Thomas W.; Klemm, Albrecht

2008-10-01

We study the mediation of supersymmetry breaking triggered by background fluxes in Type II string compactifications with Script N = 1 supersymmetry. The mediation arises due to an U(1) vector multiplet coupling to both a hidden supersymmetry breaking flux sector and a visible D-brane sector. The required internal manifolds can be constructed by non-Kähler resolutions of singular Calabi-Yau manifolds. The effective action encoding the U(1) coupling is then determined in terms of the global topological properties of the internal space. We investigate suitable local geometries for the hidden and visible sector in detail. This includes a systematic study of orientifold symmetries of del Pezzo surfaces realized in compact geometries after geometric transition. We construct compact examples admitting the key properties to realize flux supersymmetry breaking and U(1) mediation. Their toric realization allows us to analyze the geometry of curve classes and confirm the topological connection between the hidden and visible sector.

Breaks induced in the deoxyribonucleic acid of aerosolized Escherichia coli by ozonized cyclohexene.

PubMed Central

De Mik, G; De Groot, I

1978-01-01

The inactivation of aerosolized Escherichia coli by ozone, cyclohexene, and ozonized cyclohexene was studied. The parameters for damage were loss of reproduction and introduction of breaks in the deoxyribonucleic acid (DNA). Aerosolization of E. coli in clean air at 80 percent relative humidity or in air containing either ozone or cyclohexene hardly affected survival; however, some breaks per DNA molecule were induced, as shown by sucrose gradient sedimentation of the DNA. Aerosolization of E. coli in air containing ozonized cyclohexene at 80 percent relative humidity decreased the survival by a factor of 10(3) or more after 1 h of exposure and induced many breaks in the DNA. PMID:341811

Sleep quality, sleepiness and the influence of workplace breaks: A cross-sectional survey of health-care workers in two US hospitals.

PubMed

Wilson, Marian; Riedy, Samantha M; Himmel, Maddy; English, Ashley; Burton, Joshua; Albritton, Sandra; Johnson, Kelsey; Morgan, Patricia; Van Dongen, Hans P A

2018-05-08

This study assessed sleep quality, sleepiness and use of workplace break opportunities in 1285 health-care workers via an online questionnaire. Two hospitals were surveyed - one with and one without a fatigue mitigation policy. Across all respondents, 68.9% reported generally taking breaks of at least 30 min and 21.7% had access to a quiet place to rest, with no significant differences between hospitals. The presence of a fatigue mitigation policy was not associated with reduced sleepiness. However, accounting for hospital and shift characteristics, employees with access to a quiet place to rest while on break had significantly lower self-reported sleepiness scores.

Stress corrosion evaluation of powder metallurgy aluminum alloy 7091 with the breaking load test method

NASA Technical Reports Server (NTRS)

Domack, Marcia S.

1987-01-01

The stress corrosion behavior of the P/M aluminum alloy 7091 is evaluated in two overaged heat treatment conditions, T7E69 and T7E70, using an accelerated test technique known as the breaking load test method. The breaking load data obtained in this study indicate that P/M 7091 alloy is highly resistant to stress corrosion in both longitudinal and transverse orientations at stress levels up to 90 percent of the material yield strength. The reduction in mean breaking stress as a result of corrosive attack is smallest for the more overaged T7E70 condition. Details of the test procedure are included.

Diagnostics of Loss of Coolant Accidents Using SVC and GMDH Models

NASA Astrophysics Data System (ADS)

Lee, Sung Han; No, Young Gyu; Na, Man Gyun; Ahn, Kwang-Il; Park, Soo-Yong

2011-02-01

As a means of effectively managing severe accidents at nuclear power plants, it is important to identify and diagnose accident initiating events within a short time interval after the accidents by observing the major measured signals. The main objective of this study was to diagnose loss of coolant accidents (LOCAs) using artificial intelligence techniques, such as SVC (support vector classification) and GMDH (group method of data handling). In this study, the methodologies of SVC and GMDH models were utilized to discover the break location and estimate the break size of the LOCA, respectively. The 300 accident simulation data (based on MAAP4) were used to develop the SVC and GMDH models, and the 33 test data sets were used to independently confirm whether or not the SVC and GMDH models work well. The measured signals from the reactor coolant system, steam generators, and containment at a nuclear power plant were used as inputs to the models, and the 60 sec time-integrated values of the input signals were used as inputs into the SVC and GMDH models. The simulation results confirmed that the proposed SVC model can identify the break location and the proposed GMDH models can estimate the break size accurately. In addition, even if the measurement errors exist and safety systems actuate, the proposed SVC and GMDH models can discover the break locations without a misclassification and accurately estimate the break size.

An Experimental Study Comparing Droplet Production by a Strong Plunging and a Weak Spilling Breaking Water Waves

NASA Astrophysics Data System (ADS)

Erinin, Martin; Wang, Dan; Towle, David; Liu, Xinan; Duncan, James

2017-11-01

In this study, the production of droplets by two mechanically generated breaking water waves is investigated in a wave tank. A strong plunging breaker and weak spilling breaker are generated repeatedly with a programmable wave maker by using two dispersively focused wave packets with the same wave maker motion profile shape (average frequency 1.15 Hz) and two overall amplitude factors. The profile histories of the breaking wave crests along the center plane of the tank are measured using cinematic laser-induced fluorescence. The droplets are measured using a high speed (650 Hz) cinematic digital in-line holographic system positioned at various locations along a horizontal plane that is 1 cm above the maximum wave crest height. The measurement plane covers the entire region in the tank where the wave breaks. The holographic system is used to obtain the droplet diameters (d, for d >100 microns) and the three components of the droplet velocities. From these measurements and counting only the droplets that are moving up, the spatio-temporal distribution of droplet generation by the two breaking waves is obtained. The main features of the droplet generation are correlated with the features and phases of the breaking process. The support of the National Science Foundation under Grant OCE0751853 from the Division of Ocean Sciences is gratefully acknowledged.

Musculoskeletal injuries in break-dancers.

PubMed

Cho, Chul Hyun; Song, Kwang Soon; Min, Byung Woo; Lee, Sung Moon; Chang, Hyuk Won; Eum, Dae Seup

2009-11-01

Since no epidemiologic studies have been reported about musculoskeletal injuries in break-dancers, there are no data on the rates and patterns of musculoskeletal injuries in this population that clinicians can use to find ways to decrease injury rate. We believe that the incidence of injuries in break-dancers is higher than assumed and that injury rates and patterns differ between professional and amateur dancers. Descriptive epidemiologic study. Of a total of 42 study subjects, 23 were professional dancers and 19 were amateur dancers. Injury frequency, site and type, along with the presence of supervised training, the use of protective devices and warm-up exercises done were recorded. Of the 42 study subjects, excluding two amateur dancers, 40 (95.2%) had had musculoskeletal injuries at more than one site. The mean number of sites per dancer was 4.60. The frequency of injury depended on the site and was as follows: wrist (69.0%), finger (61.9%), knee (61.9%), shoulder (52.4%), lumbar spine (50.0%), elbow (42.9%), cervical spine (38.1%), ankle (38.1%), foot (28.6%) and hip (16.7%). Sprain, strain and tendinitis were the most common injuries, accounting for the most cases. Of the 42 dancers, 13 (31%) had had fractures or dislocations. Eight (19.1%) learned break-dancing under supervised instruction, 17 (40.5%) used protective devices and 28 (66.7%) performed warm-up exercises before dancing. There were significant differences in age, dance career length, amount of dance training, mean number of injury sites and the presence of supervised training between professionals and amateurs (P<0.05). Clinicians must inquire thoroughly into the nature of the activities that result in both unusual and common injuries in break-dancers and educate them about safety. Careful screening, instruction and supervised training of break-dancers will help to prevent injuries.

Detection of Listeria spp. in liquid egg products and in the egg breaking plants environment and tracking of Listeria monocytogenes by PFGE.

PubMed

Rivoal, Katell; Fablet, Aurore; Courtillon, Céline; Bougeard, Stéphanie; Chemaly, Marianne; Protais, Jocelyne

2013-08-16

Human listeriosis, caused by Listeria monocytogenes, is a severe bacterial infection that can lead to meningitis, cerebromeningitis, bacteremia or septicemia, with acute lethality and potentially leading to death. A study has shown that 29.5% of the caged laying hens in France are contaminated by L. monocytogenes (Chemaly et al., 2008). However, very little information regarding egg and egg product contamination is currently available. The objective of this study is to determine the sanitary status of egg products and egg breaking plants in France regarding Listeria spp. and L. monocytogenes contaminations. The sampling scheme performed in five egg breaking plants in Western France during one year have revealed that 8.5% of raw egg products were contaminated by L. monocytogenes. No pasteurized egg products have been shown to be contaminated by L. monocytogenes. However, a high level of contamination by Listeria spp., and particularly by L. innocua, has been shown with 26.2% and 1.8% of raw and pasteurized egg products contaminated, respectively. This work has also revealed the presence of Listeria spp. and L. monocytogenes in the environment of egg breaking plants with 65.1% and 8.0% of contaminated samples, respectively. The typing of 253 isolates of L. monocytogenes by PFGE using ApaI and AscI enzymes has revealed a high diversity with 46 different pulsotypes and has shown that the raw material is a source of contamination of egg breaking plants. One L. monocytogenes cluster was dominant in the 5 egg-breaking plants during the four seasons studied. The issue of which strains are better adapted to egg products must be considered and studied in depth by comparing them to pulsotypes from strains of other chains. However, the traceability of L. monocytogenes in plants during the various seasons has also made it possible to highlight the presence of strains that are specific to egg breaking plants. The study of cleaning and disinfection methods in these plants as well as the recurring bacteria's resistance to disinfectants could provide answers to the egg product industry. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultrafast-laser dicing of thin silicon wafers: strategies to improve front- and backside breaking strength

NASA Astrophysics Data System (ADS)

Domke, Matthias; Egle, Bernadette; Stroj, Sandra; Bodea, Marius; Schwarz, Elisabeth; Fasching, Gernot

2017-12-01

Thin 50-µm silicon wafers are used to improve heat dissipation of chips with high power densities. However, mechanical dicing methods cause chipping at the edges of the separated dies that reduce the mechanical stability. Thermal load changes may then lead to sudden chip failure. Recent investigations showed that the mechanical stability of the cut chips could be increased using ultrashort-pulsed lasers, but only at the laser entrance (front) side and not at the exit (back) side. The goal of this study was to find strategies to improve both front- and backside breaking strength of chips that were cut out of an 8″ wafer with power metallization using an ultrafast laser. In a first experiment, chips were cut by scanning the laser beam in single lines across the wafer using varying fluencies and scan speeds. Three-point bending tests of the cut chips were performed to measure front and backside breaking strengths. The results showed that the breaking strength of both sides increased with decreasing accumulated fluence per scan. Maximum breaking strengths of about 1100 MPa were achieved at the front side, but only below 600 MPa were measured for the backside. A second experiment was carried out to optimize the backside breaking strength. Here, parallel line scans to increase the distance between separated dies and step cuts to minimize the effect of decreasing fluence during scribing were performed. Bending tests revealed that breaking strengths of about 1100 MPa could be achieved also on the backside using the step cut. A reason for the superior performance could be found by calculating the fluence absorbed by the sidewalls. The calculations suggested that an optimal fluence level to minimize thermal side effects and periodic surface structures was achieved due to the step cut. Remarkably, the best breaking strengths values achieved in this study were even higher than the values obtained on state of the art ns-laser and mechanical dicing machines. This is the first study to the knowledge of the authors, which demonstrates that ultrafast-laser dicing improves the mechanical stability of thin silicon chips.

Breaking the news or fueling the epidemic? Temporal association between news media report volume and opioid-related mortality.

PubMed

Dasgupta, Nabarun; Mandl, Kenneth D; Brownstein, John S

2009-11-18

Historical studies of news media have suggested an association between reporting and increased drug abuse. Period effects for substance use have been documented for different classes of legal and illicit substances, with the suspicion that media publicity may have played major roles in their emergence. Previous analyses have drawn primarily from qualitative evidence; the temporal relationship between media reporting volume and adverse health consequences has not been quantified nationally. We set out to explore whether we could find a quantitative relationship between media reports about prescription opioid abuse and overdose mortality associated with these drugs. We assessed whether increases in news media reports occurred before or after increases in overdose deaths. Our ecological study compared a monthly time series of unintentional poisoning deaths involving short-acting prescription opioid substances, from 1999 to 2005 using multiple cause-of-death data published by the National Center for Health Statistics, to monthly counts of English-language news articles mentioning generic and branded names of prescription opioids obtained from Google News Archives from 1999 to 2005. We estimated the association between media volume and mortality rates by time-lagged regression analyses. There were 24,272 articles and 30,916 deaths involving prescription opioids during the seven-year study period. Nationally, the number of articles mentioning prescription opioids increased dramatically starting in early 2001, following prominent coverage about the nonmedical use of OxyContin. We found a significant association between news reports and deaths, with media reporting preceding fatal opioid poisonings by two to six months and explaining 88% (p<0.0001, df 78) of the variation in mortality. While availability, structural, and individual predispositions are key factors influencing substance use, news reporting may enhance the popularity of psychoactive substances. Albeit ecological in nature, our finding suggests the need for further evaluation of the influence of news media on health. Reporting on prescription opioids conforms to historical patterns of news reporting on other psychoactive substances.

Breaks and maintenance work in the water distribution systems and gastrointestinal illness: a cohort study.

PubMed

Nygård, Karin; Wahl, Erik; Krogh, Truls; Tveit, Odd Atle; Bøhleng, Erik; Tverdal, Aage; Aavitsland, Preben

2007-08-01

During maintenance work or breaks on the water distribution system, water pressure occasionally will be reduced. This may lead to intrusion of polluted water-either at the place of repair or through cracks or leaks elsewhere in the distribution system. The objective of this study was to assess whether breaks or maintenance work in the water distribution system with presumed loss of water pressure was associated with an increased risk of gastrointestinal illness among recipients. We conducted a cohort study among recipients of water from seven waterworks in Norway during 2003-04. One week after an episode of mains breaks or maintenance work on the water distribution system, the exposed and unexposed households were interviewed about gastrointestinal illness in the week following the episode. During the 1-week period after the episode, 12.7% of the exposed households reported gastrointestinal illness in the household, compared with 8.0% in the unexposed households [risk ratio (RR) 1.58, 95% confidence interval (CI): 1.1, 2.3]. The risk was highest in households with higher average water consumption. The attributable fraction among the exposed households was 37% in the week following exposure. Our results show that breaks and maintenance work in the water distribution systems caused an increased risk of gastrointestinal illness among water recipients. Better data on the occurrence of low-pressure episodes and improved registration of mains breaks and maintenance work on the water distribution network are needed in order to assess the public health burden of contamination of drinking water within the distribution network.

Validation of ALK/ROS1 Dual Break Apart FISH Probe probe in non-small-cell lung cancer.

PubMed

Lim, Sun Min; Chang, Hyun; Cha, Yoon Jin; Liang, Shile; Tai, Yan Chin; Li, Gu; Pestova, Ekaterina; Policht, Frank; Perez, Thomas; Soo, Ross A; Park, Won Young; Kim, Hye Ryun; Shim, Hyo Sup; Cho, Byoung Chul

2017-09-01

ALK and ROS1 gene rearrangements are distinct molecular subsets of non-small-cell lung cancer (NSCLC), and they are strong predictive biomarkers of response to ALK/ROS1 inhibitors, such as crizotinib. Thus, it is clinically important to develop an effective screening strategy to detect patients who will benefit from such treatment. In this study, we aimed to validate analytical performance of Vysis ALK/ROS1 Dual Break Apart Probe Kit (RUO) in NSCLC. Study population composed of three patient cohorts with histologically confirmed lung adenocarcinoma (patients with ALK rearrangement, patients with ROS1 rearrangement and patients with wild-type ALK and ROS1). Specimens consisted of 12 ALK-positive, 8 ROS1-positive and 21 ALK/ROS1-wild type formalin-fixed paraffin-embedded samples obtained from surgical resection or excisional biopsy. ALK rearrangement was previously assessed by Vysis ALK Break Apart FISH Probe Kit (Abbott Molecular, Abbot Park, IL, USA) and ROS1 rearrangement was previously assessed by ZytoLight ® SPEC ROS1 Break Apart Probe (ZytoVision, GmbH). All specimens were re-evaluated by Vysis ALK/ROS1 Dual Break Apart Probe Kit. FISH images were scanned on BioView AllegroPlus system and interpreted via BioView SoloWeb remotely. For a total of 41 patient samples, the concordance of the results by Vysis ALK/ROS1 Dual Break Apart Probe Kit was evaluated and compared to the known ALK and ROS1 rearrangement status of the specimen. Of the 12 ALK-positive cases, hybridization with Vysis ALK/ROS1 Dual Break Apart Probe Kit was successful in 10 cases (success rate 10/12, 83%) and of these 10 cases, all showed ALK rearrangement (100% concordance with the results of Vysis ALK Break Apart FISH Probe Kit). Two of the ALK+ cases were excluded due to weak ROS1 signals that could not be enumerated. Of the 8 ROS1-positive cases, 6 cases were successfully evaluated using Vysis ALK/ROS1 Dual Break Apart Probe Kit. The success rate was 75% (6/8), and of these 6 cases, all showed ROS1 rearrangement, giving a 100% concordance with ZytoLight ® SPEC ROS1 Break Apart Probe. Two of the cases were excluded due to weak ROS1 gold signal or high background. In the cohort of 21 wild-type cases, the success rate using Vysis ALK/ROS1 Dual Break Apart FISH Probe Kit was 85% (18/21) and the concordance with ALK and ROS1 probe kit was 100% (18/18). Vysis ALK/ROS1 Dual Break Apart Probe Kit (RUO) can detect ALK and ROS1 rearrangement simultaneously in NSCLC. Copyright © 2017 Elsevier B.V. All rights reserved.

Dependence of Wave-Breaking Statistics on Wind Stress and Wave Development

NASA Technical Reports Server (NTRS)

Katsaros, Kristina B.; Atakturk, Serhad S.

1992-01-01

Incidence of wave breaking for pure wind driven waves has been studied on Lake Washington at wind speeds up to 8 m/s. Video recordings were employed to identify and categorize the breaking events in terms of micro-scale, spilling and plunging breakers. These events were correlated with the magnitude of the wave spectrum measured with a resistance wire wave gauge and band pass filtered between 6 and 10 Hz. An equivalent percentage of breaking crests were found for spilling and plunging events. Wave forcing as measured by wind stress (or friction velocity, u(sub *), squared) and by inverse wave age, u(sub *)/Cp where Cp is the phase velocity of the waves at the peak of the frequency spectrum, were found to be good prerictors of percentage of breaking crests. When combined in a two parameter regression, those two variables gave small standard deviation and had a high correlation coefficient (66 percent). The combination of u(sub *)(exp 2) and u(sub *)/Cp can be understood in physical terms. Furthermore, for the larger values of u(sub *)(exp 2) the dependence of wave braking and wave age was stronger than at the low end of the values u(sub *)(exp 2) and u(sub *)/Cp. Thus, both the level of wave development as determined by inverse wave age, which we may term relative wind effectiveness for wave forcing and the wind forcing on the water surface determine the incidence of wave breaking. Substituting U(sub 10)(sup 3.75) (which is the dependence of whitecap cover found by Monahan and coworkers) an equivalent correlation was found to the prediction by u(sub *)(exp 2). Slightly better standard deviation value and higher correlation coefficient were found by using a Reynolds number as predictor. A two-parameter regression involving u(sub *)(exp 2) and a Reynold's number proposed by Toba and his colleagues which relates u(sub *)(exp 2) and peak wave frequency, improves the correlation even more but is less easy to interpret in physical terms. The equivalent percentage of breaking crests obtained in our previous study was reported at 8.6 percent for a short record obtained at U(sub 10N) of about 6 m/s. Typical values in the current study for similar conditions are 6 percent, which is consistent with the previous study in view of the scatter. In that study we did not have a video recording system, so the observed breaking may include more of the micro-scaic breaking events, and the value, 8.6 percent, is well within the range of highly probable sampling variability.

Monitoring ice break-up on the Mackenzie River using MODIS data

NASA Astrophysics Data System (ADS)

Muhammad, P.; Duguay, C.; Kang, K.-K.

2016-03-01

The aim of this study was to develop an approach for estimating ice break-up dates on the Mackenzie River (MR) using more than a decade of MODIS Level 3 500 m snow products (MOD/MYD10A1), complemented with 250 m Level 1B radiance products (MOD/MYD02QKM) from the Terra and Aqua satellite platforms. The analysis showed break-up began on average between days of year (DOYs) 115 and 125 and ended between DOYs 145 and 155 over 13 ice seasons (2001-2013), resulting in an average melt duration of ca. 30-40 days. Thermal processes were more important in driving ice break-up south of the MR confluence with the Liard River, while dynamically driven break-up was more important north of the Liard. A comparison of the timing of ice disappearance with snow disappearance from surrounding land areas of the MR with MODIS Level 3 snow products showed varying relationships along the river. Ice-off and snow-off timing were in sync north of the MR-Liard River confluence and over sections of the MR before it enters the Mackenzie Delta, but ice disappeared much later than snow on land in regions where thermal ice break-up processes dominated. MODIS observations revealed that channel morphology is a more important control of ice break-up patterns than previously believed with ice runs on the MR strongly influenced by channel morphology (islands and bars, confluences and channel constriction). Ice velocity estimates from feature tracking were able to be made in 2008 and 2010 and yielded 3-4-day average ice velocities of 1.21 and 1.84 m s-1 respectively, which is in agreement with estimates from previous studies. These preliminary results confirm the utility of daily MODIS data for monitoring ice break-up processes along the Mackenzie River. The addition of optical and synthetic aperture radar data from recent and upcoming satellite missions (e.g. Sentinel-1/2/3 and RADARSAT Constellation) would improve the monitoring of ice break-up in narrower sections of the MR.

Numerical study of the effects of contact angle and viscosity ratio on the dynamics of snap-off through porous media

NASA Astrophysics Data System (ADS)

Starnoni, Michele; Pokrajac, Dubravka

2018-01-01

Snap-off is a pore-scale mechanism occurring in porous media in which a bubble of non-wetting phase displacing a wetting phase, and vice-versa, can break-up into ganglia when passing through a constriction. This mechanism is very important in foam generation processes, enhanced oil recovery techniques and capillary trapping of CO2 during its geological storage. In the present study, the effects of contact angle and viscosity ratio on the dynamics of snap-off are examined by simulating drainage in a single pore-throat constriction of variable cross-section, and for different pore-throat geometries. To model the flow, we developed a CFD code based on the Finite Volume method. The Volume-of-fluid method is used to track the interfaces. Results show that the threshold contact angle for snap-off, i.e. snap-off occurs only for contact angles smaller than the threshold, increases from a value of 28° for a circular cross-section to 30-34° for a square cross-section and up to 40° for a triangular one. For a throat of square cross-section, increasing the viscosity of the injected phase results in a drop in the threshold contact angle from a value of 30° when the viscosity ratio μ bar is equal to 1 to 26° when μ bar = 20 and down to 24° when μ bar = 20 .

Using data from monitoring combined sewer overflows to assess, improve, and maintain combined sewer systems.

PubMed

Montserrat, A; Bosch, Ll; Kiser, M A; Poch, M; Corominas, Ll

2015-02-01

Using low-cost sensors, data can be collected on the occurrence and duration of overflows in each combined sewer overflow (CSO) structure in a combined sewer system (CSS). The collection and analysis of real data can be used to assess, improve, and maintain CSSs in order to reduce the number and impact of overflows. The objective of this study was to develop a methodology to evaluate the performance of CSSs using low-cost monitoring. This methodology includes (1) assessing the capacity of a CSS using overflow duration and rain volume data, (2) characterizing the performance of CSO structures with statistics, (3) evaluating the compliance of a CSS with government guidelines, and (4) generating decision tree models to provide support to managers for making decisions about system maintenance. The methodology is demonstrated with a case study of a CSS in La Garriga, Spain. The rain volume breaking point from which CSO structures started to overflow ranged from 0.6 mm to 2.8 mm. The structures with the best and worst performance in terms of overflow (overflow probability, order, duration and CSO ranking) were characterized. Most of the obtained decision trees to predict overflows from rain data had accuracies ranging from 70% to 83%. The results obtained from the proposed methodology can greatly support managers and engineers dealing with real-world problems, improvements, and maintenance of CSSs. Copyright © 2014 Elsevier B.V. All rights reserved.

The effects of a mid-task break on the brain connectome in healthy participants: A resting-state functional MRI study.

PubMed

Sun, Yu; Lim, Julian; Dai, Zhongxiang; Wong, KianFoong; Taya, Fumihiko; Chen, Yu; Li, Junhua; Thakor, Nitish; Bezerianos, Anastasios

2017-05-15

Although rest breaks are commonly administered as a countermeasure to reduce mental fatigue and boost cognitive performance, the effects of taking a break on behavior are not consistent. Moreover, our understanding of the underlying neural mechanisms of rest breaks and how they modulate mental fatigue is still rudimentary. In this study, we investigated the effects of receiving a rest break on the topological properties of brain connectivity networks via a two-session experimental paradigm, in which one session comprised four successive blocks of a mentally demanding visual selective attention task (No-rest session), whereas the other contained a rest break between the second and third task blocks (Rest session). Functional brain networks were constructed using resting-state functional MRI data recorded from 20 healthy adults before and after the performance of the task blocks. Behaviorally, subjects displayed robust time-on-task (TOT) declines, as reflected by increasingly slower reaction time as the test progressed and lower post-task self-reported ratings of engagement. However, we did not find a significant effect on task performance due to administering a mid-task break. Compared to pre-task measurements, post-task functional brain networks demonstrated an overall decrease of optimal small-world properties together with lower global efficiency. Specifically, we found TOT-related reduced nodal efficiency in brain regions that mainly resided in the subcortical areas. More interestingly, a significant block-by-session interaction was revealed in local efficiency, attributing to a significant post-task decline in No-rest session and a preserved local efficiency when a mid-task break opportunity was introduced in the Rest session. Taken together, these findings augment our understanding of how the resting brain reorganizes following the accumulation of prolonged task, suggest dissociable processes between the neural mechanisms of fatigue and recovery, and provide some of the first quantitative insights into the cognitive neuroscience of work and rest. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct microscopic image and measurement of the atomization process of a port fuel injector

NASA Astrophysics Data System (ADS)

Esmail, Mohamed; Kawahara, Nobuyuki; Tomita, Eiji; Sumida, Mamoru

2010-07-01

The main objective of this study is to observe and investigate the phenomena of atomization, i.e. the fuel break-up process very close to the nozzle exit of a practical port fuel injector (PFI). In order to achieve this objective, direct microscopic images of the atomization process were obtained using an ultra-high-speed video camera that could record 102 frames at rates of up to 1 Mfps, coupled with a long-distance microscope and Barlow lens. The experiments were carried out using a PFI in a closed chamber at atmospheric pressure. Time-series images of the spray behaviour were obtained with a high temporal resolution using backlighting. The direct microscopic images of a liquid column break-up were compared with experimental results from laser-induced exciplex fluorescence (LIEF), and the wavelength obtained from the experimental results compared with that predicated from the Kelvin-Helmholtz break-up model. The droplet size diameters from a ligament break-up were compared with results predicated from Weber's analysis. Furthermore, experimental results of the mean droplet diameter from a direct microscopic image were compared with the results obtained from phase Doppler anemometry (PDA) experimental results. Three conclusions were obtained from this study. The atomization processes and detailed characterizations of the break-up of a liquid column were identified; the direct microscopic image results were in good agreement with the results obtained from LIEF, experimental results of the wavelength were in good agreement with those from the Kelvin-Helmholtz break-up model. The break-up process of liquid ligaments into droplets was investigated, and Weber's analysis of the predicated droplet diameter from ligament break-up was found to be applicable only at larger wavelengths. Finally, the direct microscopic image method and PDA method give qualitatively similar trends for droplet size distribution and quantitatively similar values of Sauter mean diameter.

DNA Resection at Chromosome Breaks Promotes Genome Stability by Constraining Non-Allelic Homologous Recombination

PubMed Central

Koshland, Douglas

2012-01-01

DNA double-strand breaks impact genome stability by triggering many of the large-scale genome rearrangements associated with evolution and cancer. One of the first steps in repairing this damage is 5′→3′ resection beginning at the break site. Recently, tools have become available to study the consequences of not extensively resecting double-strand breaks. Here we examine the role of Sgs1- and Exo1-dependent resection on genome stability using a non-selective assay that we previously developed using diploid yeast. We find that Saccharomyces cerevisiae lacking Sgs1 and Exo1 retains a very efficient repair process that is highly mutagenic to genome structure. Specifically, 51% of cells lacking Sgs1 and Exo1 repair a double-strand break using repetitive sequences 12–48 kb distal from the initial break site, thereby generating a genome rearrangement. These Sgs1- and Exo1-independent rearrangements depend partially upon a Rad51-mediated homologous recombination pathway. Furthermore, without resection a robust cell cycle arrest is not activated, allowing a cell with a single double-strand break to divide before repair, potentially yielding multiple progeny each with a different rearrangement. This profusion of rearranged genomes suggests that cells tolerate any dangers associated with extensive resection to inhibit mutagenic pathways such as break-distal recombination. The activation of break-distal recipient repeats and amplification of broken chromosomes when resection is limited raise the possibility that genome regions that are difficult to resect may be hotspots for rearrangements. These results may also explain why mutations in resection machinery are associated with cancer. PMID:22479212

On the Full-range β Dependence of Ion-scale Spectral Break in the Solar Wind Turbulence

NASA Astrophysics Data System (ADS)

Wang, Xin; Tu, Chuanyi; He, Jiansen; Wang, Linghua

2018-04-01

The power spectrum of magnetic fluctuations has a break at the high-frequency end of the inertial range. Beyond this break, the spectrum becomes steeper than the Kolmogorov law f ‑5/3. The break frequency was found to be associated with plasma beta (β). However, the full-range β dependence of the ion-scale spectral break has not been presented before in observational studies. Here we show the continuous variation of the break frequency on full-range β in the solar wind turbulence. By using measurements from the WIND and Ulysses spacecraft, we show the break frequency (f b ) normalized, respectively, by the frequencies corresponding to ion inertial length (f di ), ion gyroradius ({f}ρ i), and cyclotron resonance scale (f ri ) as a function of β for 1306 intervals. Their β values spread from 0.005 to 20, which nearly covers the full β range of the observed solar wind turbulence. It is found that {f}b/{f}{di} ({f}b/{f}ρ i) generally decreases (increases) with β, while {f}b/{f}{ri} is nearly a constant. We perform a linear fit on the statistical result, and obtain the empirical formulas {f}b/{f}{di}∼ {β }-1/4, {f}b/{f}ρ i∼ {β }1/4, and {f}b/{f}{ri}∼ 0.90 to describe the relation between f b and β. We also compare our observations with a numerical simulation and the prediction by ion cyclotron resonance theory. Our result favors the idea that the cyclotron resonance is an important mechanism for energy dissipation at the spectral break. When β ≪ 1 and β ≫ 1, the break at f di and {f}ρ i may also be associated with other processes.

Chiral symmetry breaking in a semilocalized magnetic field

NASA Astrophysics Data System (ADS)

Cao, Gaoqing

2018-03-01

In this work, we explore the pattern of chiral symmetry breaking and restoration in a solvable magnetic field configuration within the Nambu-Jona-Lasinio model. The special semilocalized static magnetic field can roughly mimic the realistic situation in peripheral heavy ion collisions; thus, the study is important for the dynamical evolution of quark matter. We find that the magnetic-field-dependent contribution from discrete spectra usually dominates over the contribution from continuum spectra and chiral symmetry breaking is locally catalyzed by both the magnitude and scale of the magnetic field. The study is finally extended to the case with finite temperature or chemical potential.

An Experimental Study of Droplets Produced by a Plunging Breakers

NASA Astrophysics Data System (ADS)

Erinin, Martin; Wang, Dan; Towle, David; Liu, Xinan; Duncan, James

2016-11-01

In this study, the production of droplets by a mechanically generated plunging breaking water wave is investigated in a wave tank. The breaker, with an amplitude of 0.070 m, is generated repeatedly with a programmable wave maker by using a dispersively focused wave packet (average frequency 1.15 Hz). The profile histories of the breaking wave crests along the center plane of the tank are measured using cinematic laser-induced fluorescence. The droplets are measured using a cinematic digital in-line holographic system positioned at 30 locations along a horizontal plane that is 1 cm above the maximum wave crest height. This measurement plane covers the entire region in the tank where the wave breaks. The holographic system is used to obtain the droplet diameters (d, for d >100 microns) and the three components of the droplet velocities. From these measurements and counting only the droplets that are moving up, the spatio-temporal distribution of droplet generation by the breaking wave is obtained. The main features of the droplet generation are correlated with the features and phases of the breaking process. The support of the National Science Foundation under Grant OCE0751853 from the Division of Ocean Sciences is gratefully acknowledged.

Use of a GIS-based hybrid artificial neural network to prioritize the order of pipe replacement in a water distribution network.

PubMed

Ho, Cheng-I; Lin, Min-Der; Lo, Shang-Lien

2010-07-01

A methodology based on the integration of a seismic-based artificial neural network (ANN) model and a geographic information system (GIS) to assess water leakage and to prioritize pipeline replacement is developed in this work. Qualified pipeline break-event data derived from the Taiwan Water Corporation Pipeline Leakage Repair Management System were analyzed. "Pipe diameter," "pipe material," and "the number of magnitude-3( + ) earthquakes" were employed as the input factors of ANN, while "the number of monthly breaks" was used for the prediction output. This study is the first attempt to manipulate earthquake data in the break-event ANN prediction model. Spatial distribution of the pipeline break-event data was analyzed and visualized by GIS. Through this, the users can swiftly figure out the hotspots of the leakage areas. A northeastern township in Taiwan, frequently affected by earthquakes, is chosen as the case study. Compared to the traditional processes for determining the priorities of pipeline replacement, the methodology developed is more effective and efficient. Likewise, the methodology can overcome the difficulty of prioritizing pipeline replacement even in situations where the break-event records are unavailable.

Why soft UV-A damages DNA: An optical micromanipulation study

NASA Astrophysics Data System (ADS)

Rapp, A.; Greulich, K. O.

2013-09-01

Optical micromanipulation studies have solved a puzzle on DNA damage and repair. Such knowledge is crucial for understanding cancer and ageing. So far it was not understood, why the soft UV component of sunlight, UV-A, causes the dangerous DNA double strand breaks. The energy of UV-A photons is below 4 eV per photon, too low to directly cleave the corresponding chemical bonds in DNA. This is occasionally used to claim that artificial sunbeds, which mainly use UV-A, would not impose a risk on health. UV-A is only sufficient for induction of single strand breaks. The essential new observation is that, when on the opposite strand there is another single strand break at a distance of up to 20 base pairs. These two breaks will be converted into a break of the whole double strand with all its known consequences for cancer and ageing. However, in natural sun the effect is counteracted. Simultaneous red light illumination reduces UV induced DNA damages to 1/3. Since sunlight has a red component, skin tanning with natural sun is not as risky as might appear at a first glance.

Dynamic breaking of a single gold bond

NASA Astrophysics Data System (ADS)

Pobelov, Ilya V.; Lauritzen, Kasper Primdal; Yoshida, Koji; Jensen, Anders; Mészáros, Gábor; Jacobsen, Karsten W.; Strange, Mikkel; Wandlowski, Thomas; Solomon, Gemma C.

2017-07-01

While one might assume that the force to break a chemical bond gives a measure of the bond strength, this intuition is misleading. If the force is loaded slowly, thermal fluctuations may break the bond before it is maximally stretched, and the breaking force will be less than the bond can sustain. Conversely, if the force is loaded rapidly it is more likely that the maximum breaking force is measured. Paradoxically, no clear differences in breaking force were observed in experiments on gold nanowires, despite being conducted under very different conditions. Here we explore the breaking behaviour of a single Au-Au bond and show that the breaking force is dependent on the loading rate. We probe the temperature and structural dependencies of breaking and suggest that the paradox can be explained by fast breaking of atomic wires and slow breaking of point contacts giving very similar breaking forces.

Hybrid Eulerian and Lagrangian Simulation of Steep and Breaking Waves and Surface Fluxes in High Winds

DTIC Science & Technology

2012-09-30

Lagrangian methods for free - surface turbulence and wave simulation . In the far field, coupled wind and wave simulations are used to obtain wind...to conserve the mass precisely. When the wave breaks, the flow at the free surface may become very violent, air and water may be highly mixed...fluids free - surface flows that can be used to study the fundamental physics of wave breaking. The research will improve the understanding of air-sea

Exposure to nature versus relaxation during lunch breaks and recovery from work: development and design of an intervention study to improve workers' health, well-being, work performance and creativity.

PubMed

de Bloom, Jessica; Kinnunen, Ulla; Korpela, Kalevi

2014-05-22

The objective of this research project is to understand and to improve workers' recovery from work stress. Although recovery during lunch breaks is the most common within-workday break, it has received only minor research attention. Therefore, we will study whether lunch breaks including a relaxation session or exposure to nature have more favorable outcomes than usually spent lunch breaks concerning: a) recovery processes, b) health, c) well-being, d) job performance and e) creativity. We approach recovery by combining the theoretical frameworks of work and environmental psychology. We conduct an intervention study in a sample of 268 knowledge-workers who engage in different lunch break activities for 15-minutes per day, two weeks in a row. We randomly assign participants to three experimental conditions: 1) exposure to nature, 2) relaxation and 3) control group (lunch break spent as usual). Online questionnaires before and after the intervention assess long term changes regarding recovery processes and the major outcome variables. Before, during and after the intervention, SMS and paper-pencil questionnaires measure the same constructs four times a day with fewer items. We also measure blood pressure and collect saliva samples to map cortisol excretion across the intervention period. A timed experimental task (i.e., the Alternative Uses Task) is used to examine differences in creativity between the three groups after the intervention period. By combining the knowledge of work and environmental psychology about recovery and restorative experiences, by merging three recovery perspectives (settings, processes, and outcomes) and by using data triangulation, we produce valid results that broaden our view on mechanisms underlying recovery and enhance our understanding about their links to psychological, behavioural and physiological outcomes, resulting in a more comprehensive picture of work stress recovery in general. ClinicalTrials.gov Protocol Registration System NCT02124837. Registered 24 April 2014.

Exposure to nature versus relaxation during lunch breaks and recovery from work: development and design of an intervention study to improve workers’ health, well-being, work performance and creativity

PubMed Central

2014-01-01

Background The objective of this research project is to understand and to improve workers’ recovery from work stress. Although recovery during lunch breaks is the most common within-workday break, it has received only minor research attention. Therefore, we will study whether lunch breaks including a relaxation session or exposure to nature have more favorable outcomes than usually spent lunch breaks concerning: a) recovery processes, b) health, c) well-being, d) job performance and e) creativity. We approach recovery by combining the theoretical frameworks of work and environmental psychology. Methods/Design We conduct an intervention study in a sample of 268 knowledge-workers who engage in different lunch break activities for 15-minutes per day, two weeks in a row. We randomly assign participants to three experimental conditions: 1) exposure to nature, 2) relaxation and 3) control group (lunch break spent as usual). Online questionnaires before and after the intervention assess long term changes regarding recovery processes and the major outcome variables. Before, during and after the intervention, SMS and paper-pencil questionnaires measure the same constructs four times a day with fewer items. We also measure blood pressure and collect saliva samples to map cortisol excretion across the intervention period. A timed experimental task (i.e., the Alternative Uses Task) is used to examine differences in creativity between the three groups after the intervention period. Discussion By combining the knowledge of work and environmental psychology about recovery and restorative experiences, by merging three recovery perspectives (settings, processes, and outcomes) and by using data triangulation, we produce valid results that broaden our view on mechanisms underlying recovery and enhance our understanding about their links to psychological, behavioural and physiological outcomes, resulting in a more comprehensive picture of work stress recovery in general. Trial registration ClinicalTrials.gov Protocol Registration System NCT02124837. Registered 24 April 2014. PMID:24885178

Flow-type landslides magnitude evaluation: the case study of the Campania Region (Southern Italy)

NASA Astrophysics Data System (ADS)

Santo, Antonio; De Falco, Melania; Di Crescenzo, Giuseppe

2015-04-01

In the last years studies concerning the triggering and the run-out susceptibility for different kind of landslides have become more and more precise. In the most of the cases the methodological approach involve the production of detailed thematic maps (at least 1:5000 scale) which represent a very useful tool for territorial planning, especially in urbanized areas. More recently these researches were accompanied by the growth of other studies dealing with landslide magnitude evaluation (especially in terms of volume and velocity estimate). In this paper the results of a flow-type landslides magnitude evaluation are presented. The study area is located in Southern Italy and is very wide (1,500 square kilometres) including all the Campania region. In this context flow type landslides represent the most frequent instabilities as shown by the large number of victims and the huge economic damage caused in the last few centuries. These shallow landslides involve thin cohesionless, unsaturated pyroclastic soils found over steep slopes around Somma-Vesuvio and Phlegrean district, affecting a wide area where over 100 towns are located. Since the potential volume of flow-type landslides is a measure of event magnitude we propose to estimate the potential volume at the scale of slope or basin for about 90 municipalities affecting 850 hierarchized drainage basins and 900 regular slopes. An empirical approach recently proposed in literature (De Falco et al., 2012), allows to estimate the volume of the pyroclastic cover that can be displaced along the slope. The method derives from the interpretation of numerous geological and geomorphological data gathered from a vast amount of case histories on landslides in volcanic and carbonatic contexts and it is based on determining the thickness of the pyroclastic cover and the width of the detachment and erosion-transport zone. Thickness can be evaluated with a good degree of approximation since, in these landslides, the failure surface is always very superficial (from 0.3 to 2 m) and positioned in pyroclastic covers resting on a generally rigid bedrock (calcareous rocks, lava or tuffs). The area of the detachment and erosion-transport zone (Af) is calculated by a mathematical function (statistical correlation) which link this factor with the difference in height (H) between a point on the slope with the highest susceptibility and a point, the first break at the foot of the slope, where the deposition starts to take place and the landslide loses velocity. Finally, potential volumes are calculated by using Af and a constant thickness of the pyroclastic cover for the whole slope. The volumes estimated were classified using the size classification proposed by Jacob (2005) to view the spatial distribution at regional and municipal scales. At the regional scale the study showed a variability of the volume potentially mobilized that ranging from 500 to 200,000 cubic meters; a non-random distribution of volumes mobilized that allows to show different macro-areas with several degrees of hazard. At the municipal scale the distribution of the volumes mobilized allows to identify the most dangerous landslides scenario. The result could represent a useful tool to define the most critical area in the Civil Protection and to detect the main areas where risk mitigation works are required.

Revealing W51C as a Cosmic-Ray source using Fermi-LAT data

DOE PAGES

Jogler, T.; Funk, S.

2016-01-10

Here, supernova remnants (SNRs) are commonly believed to be the primary sources of Galactic cosmic rays. Despite intensive study of the non-thermal emission of many SNRs the identification of the accelerated particle type relies heavily on assumptions of ambient-medium parameters that are only loosely constrained. Compelling evidence of hadronic acceleration can be provided by detecting a strong roll-off in the secondary γ-ray spectrum below themore » $${\\pi }^{0}$$ production threshold energy of about 135 MeV, the so called "pion bump." Here we use five years of Fermi-Large Area Telescope data to study the spectrum above 60 MeV of the middle-aged SNR W51C. A clear break in the power-law γ-ray spectrum at $${E}_{{\\rm{break}}}=290\\pm 20\\;{\\rm{MeV}}$$ is detected with $$9\\sigma $$ significance and we show that this break is most likely associated with the energy production threshold of $${\\pi }^{0}$$mesons. A high-energy break in the γ-ray spectrum at about 2.7 GeV is found with $$7.5\\sigma $$ significance. The spectral index at energies beyond this second break is $${{\\rm{\\Gamma }}}_{2}={2.52}_{-0.07}^{+0.06}$$ and closely matches the spectral index derived by the MAGIC Collaboration above 75 GeV. Therefore our analysis provides strong evidence to explain the γ-ray spectrum of W51C by a single particle population of protons with a momentum spectrum best described by a broken power law with break momentum $${p}_{{\\rm{break}}}\\sim 80\\;{\\rm{G}}{\\rm{e}}{\\rm{V}}/c.$$ W51C is the third middle-aged SNR that displays compelling evidence for cosmic-ray acceleration and thus strengthens the case of SNRs as the main source of Galactic cosmic rays.« less

Exploring non-holomorphic soft terms in the framework of gauge mediated supersymmetry breaking

NASA Astrophysics Data System (ADS)

Chattopadhyay, Utpal; Das, Debottam; Mukherjee, Samadrita

2018-01-01

It is known that in the absence of a gauge singlet field, a specific class of supersymmetry (SUSY) breaking non-holomorphic (NH) terms can be soft breaking in nature so that they may be considered along with the Minimal Supersymmetric Standard Model (MSSM) and beyond. There have been studies related to these terms in minimal supergravity based models. Consideration of an F-type SUSY breaking scenario in the hidden sector with two chiral superfields however showed Planck scale suppression of such terms. In an unbiased point of view for the sources of SUSY breaking, the NH terms in a phenomenological MSSM (pMSSM) type of analysis showed a possibility of a large SUSY contribution to muon g - 2, a reasonable amount of corrections to the Higgs boson mass and a drastic reduction of the electroweak fine-tuning for a higgsino dominated {\\tilde{χ}}_1^0 in some regions of parameter space. We first investigate here the effects of the NH terms in a low scale SUSY breaking scenario. In our analysis with minimal gauge mediated supersymmetry breaking (mGMSB) we probe how far the results can be compared with the previous pMSSM plus NH terms based study. We particularly analyze the Higgs, stop and the electroweakino sectors focusing on a higgsino dominated {\\tilde{χ}}_1^0 and {\\tilde{χ}}_1^{± } , a feature typically different from what appears in mGMSB. The effect of a limited degree of RG evolutions and vanishing of the trilinear coupling terms at the messenger scale can be overcome by choosing a non-minimal GMSB scenario, such as one with a matter-messenger interaction.

Atmospheric Transport and Mixing linked to Rossby Wave Breaking in GFDL Dynamical Core

NASA Astrophysics Data System (ADS)

Liu, C.; Barnes, E. A.

2015-12-01

Atmospheric transport and mixing plays an important role in the global energy balance and the distribution of health-related chemical constituents. Previous studies suggest a close linkage between large-scale transport and Rossby wave breaking (RWB). In this work, we use the GFDL spectral dynamical core to investigate this relationship and study the response of RWB-related transport in different climate scenarios. In a standard control run, we quantify the contribution of RWB to the total transport and mixing of an idealized tracer. In addition, we divide the contribution further into the two types of RWB - anticyclonic wave breaking (AWB) and cyclonic wave breaking (CWB) -- and contrast their efficiency at transport and mixing. Our results are compared to a previous study in which the transport ability of the two types of RWB is studied for individual baroclinic wave life-cycles. In a series of sensitivity runs, we study the response of RWB-related transport and mixing to various states of the jet streams. The responses of the mean strength, frequency, and the efficiency of RWB-related transport are documented and the implications for the transport and mixing in a warmer climate are discussed.

Physical Activity Breaks and Student Learning: A Teacher-Research Project

ERIC Educational Resources Information Center

Camahalan, Faye Marsha G.; Ipock, Amanda R.

2015-01-01

This study is a teacher initiated action research. The purpose is to improve student learning in math using physical activity breaks during classroom lessons. The study was conducted by tracking the results of ten 5th grade students for a period of one week. Using anecdotal notes, students showed improvement on attentiveness during class…

An Accelerometer-Based Handheld System to Reduce Breaks in Performance of Young Adults with Cognitive Impairments

ERIC Educational Resources Information Center

Chang, Yao-Jen; Chen, Shu-Fang; Lu, Zhi-Zhan

2011-01-01

This study assessed the possibility of training two individuals with cognitive impairments using a system that reduced breaks in performance. This study was carried out according to an ABAB sequence in which A represented the baseline and B represented intervention phases. Data showed that the two participants significantly increased their target…

Children's Physical Activity Levels during Primary School Break Times: A Quantitative and Qualitative Research Design

ERIC Educational Resources Information Center

Powell, Emma; Woodfield, Lorayne A.; Nevill, Alan A. M.

2016-01-01

The overall aim of this study was to assess the diversity of primary school children's physical activity (PA) during outdoor recess. The study was grounded in a mixed method approach, assisting in the identification of multifaceted predictors of children's PA, including insights to social behaviours during break time. Data were obtained from…

Preliminary Design and Experimental Investigation of a Novel Pneumatic Conveying Method to Disperse Natural Fibers in Thermoset Polymers

PubMed Central

Fahimian, Mahi; Kortschot, Mark; Sain, Mohini

2016-01-01

Natural fibers can be attractive reinforcing materials in thermosetting polymers due to their low density and high specific mechanical properties. Although the research effort in this area has grown substantially over the last 20 years, manufacturing technologies to make use of short natural fibers in high volume fraction composites; are still limited. Natural fibers, after retting and preprocessing, are discontinuous and easily form entangled bundles. Dispersion and mixing these short fibers with resin to manufacture high quality, high volume fraction composites presents a significant challenge. In this paper, a novel pneumatic design for dispersion of natural fibers in their original discontinuous form is described. In this design, compressed air is used to create vacuum to feed and convey fibres while breaking down fibre clumps and dispersing them in an aerosolized resin stream. Model composite materials, made using proof-of-concept prototype equipment, were imaged with both optical and X-ray tomography to evaluate fibre and resin dispersion. The images indicated that the system was capable of providing an intimate mixture of resin and detangled fibres for two different resin viscosities. The new pneumatic process could serve as the basis of a system to produce well-dispersed high-volume fraction composites containing discontinuous natural fibres drawn directly from a loosely packed source. PMID:28773670

Planck/SDSS Cluster Mass and Gas Scaling Relations for a Volume-Complete redMaPPer Sample

NASA Astrophysics Data System (ADS)

Jimeno, Pablo; Diego, Jose M.; Broadhurst, Tom; De Martino, I.; Lazkoz, Ruth

2018-04-01

Using Planck satellite data, we construct Sunyaev-Zel'dovich (SZ) gas pressure profiles for a large, volume-complete sample of optically selected clusters. We have defined a sample of over 8,000 redMaPPer clusters from the Sloan Digital Sky Survey (SDSS), within the volume-complete redshift region 0.100 < z < 0.325, for which we construct SZ effect maps by stacking Planck data over the full range of richness. Dividing the sample into richness bins we simultaneously solve for the mean cluster mass in each bin together with the corresponding radial pressure profile parameters, employing an MCMC analysis. These profiles are well detected over a much wider range of cluster mass and radius than previous work, showing a clear trend towards larger break radius with increasing cluster mass. Our SZ-based masses fall ˜16% below the mass-richness relations from weak lensing, in a similar fashion as the "hydrostatic bias" related with X-ray derived masses. Finally, we derive a tight Y500-M500 relation over a wide range of cluster mass, with a power law slope equal to 1.70 ± 0.07, that agrees well with the independent slope obtained by the Planck team with an SZ-selected cluster sample, but extends to lower masses with higher precision.

Women's Careers and Transitions: A Collective Case Study of Leaders Who Took a Career Break to Be Stay-at-Home Mothers

ERIC Educational Resources Information Center

Webster, Janet Swanson

2010-01-01

This interpretive collective case study sought to fully understand and describe the experience of women leaders who took a career break to be stay-at-home mothers. Five women leaders representing a variety of industries and leadership roles participated in the study. Multiple methods were used to collect data with participant interviews being the…

Cooperation and competition between two symmetry breakings in a coupled ratchet

NASA Astrophysics Data System (ADS)

Li, Chen-Pu; Chen, Hong-Bin; Fan, Hong; Xie, Ge-Ying; Zheng, Zhi-Gang

2018-03-01

We investigate the collective mechanism of coupled Brownian motors in a flashing ratchet in the presence of coupling symmetry breaking and space symmetry breaking. The dependences of directed current on various parameters are extensively studied in terms of numerical simulations and theoretical analysis. Reversed motion can be achieved by modulating multiple parameters including the spatial asymmetry coefficient, the coupling asymmetry coefficient, the coupling free length and the coupling strength. The dynamical mechanism of these transport properties can be reasonably explained by the effective potential theory and the cooperation or competition between two symmetry breakings. Moreover, adjusting the Gaussian white noise intensity, which can induce weak reversed motion under certain condition, can optimize and manipulate the directed transport of the ratchet system.

DNA double-strand breaks induced by high-energy neon and iron ions in human fibroblasts. II. Probing individual notI fragments by hybridization.

PubMed

Löbrich, M; Rydberg, B; Cooper, P K

1994-08-01

The initial yields of DNA double-strand breaks induced by energetic heavy ions (425 MeV/u neon and 250, 400 and 600 MeV/u iron) in comparison to X rays were measured in normal human diploid fibroblast cells within three small areas of the genome, defined by NotI fragments of 3.2, 2.0 and 1.2 Mbp. The methodology involves NotI restriction endonuclease digestion of DNA from irradiated cells, followed by pulsed-field gel electrophoresis, Southern blotting and hybridization with probes recognizing single-copy sequences within the three NotI fragments. The gradual disappearance of the full-size NotI fragment with dose and the appearance of a smear of broken DNA molecules are quantified. Assuming Poisson statistics for the number of double-strand breaks induced per NotI fragment of known size, absolute yields of DNA double-strand breaks were calculated and determined to be linear with dose in all cases, with the neon ion (LET 32 keV/microns) producing 4.4 x 10(-3) breaks/Mbp/Gy and all three iron-ion beams (LETs from 190 to 350 keV/microns) producing 2.8 x 10(-3) breaks/Mbp/Gy, giving RBE values for production of double-strand breaks of 0.76 for neon and 0.48 for iron in comparison to our previously determined X-ray induction rate of 5.8 x 10(-3) breaks/Mbp/Gy. These RBE values are in good agreement with results of measurements over the whole genome as reported in the accompanying paper (B. Rydberg, M. Löbrich and P. Cooper, Radiat. Res. 139, 133-141, 1994). The distribution of broken DNA molecules was similar for the various radiations, supporting a random distribution of double-strand breaks induced by the heavy ions over Mbp distances; however, correlated breaks (clusters) over much smaller distances are not ruled out. Reconstitution of the 3.2 Mbp NotI fragment was studied during postirradiation incubation of the cells as a measure of rejoining of correct DNA ends. The proportion of breaks repaired decreased with increasing LET.

Progress towards understanding the nature of chromatid breakage.

PubMed

Bryant, P E; Gray, L J; Peresse, N

2004-01-01

The wide range of sensitivities of stimulated T-cells from different individuals to radiation-induced chromatid breakage indicates the involvement of several low penetrance genes that appear to link elevated chromatid breakage to cancer susceptibility. The mechanisms of chromatid breakage are not yet fully understood. However, evidence is accumulating that suggests chromatid breaks are not simply expanded DNA double-strand breaks (DSB). Three models of chromatid breakage are considered. The classical breakage-first and the Revell "exchange" models do not accord with current evidence. Therefore a derivative of Revell's model has been proposed whereby both spontaneous and radiation-induced chromatid breaks result from DSB signaling and rearrangement processes from within large looped chromatin domains. Examples of such rearrangements can be observed by harlequin staining whereby an exchange of strands occurs immediately adjacent to the break site. However, these interchromatid rearrangements comprise less than 20% of the total breaks. The rest are thought to result from intrachromatid rearrangements, including a very small proportion involving complete excision of a looped domain. Work is in progress with the aim of revealing these rearrangements, which may involve the formation of inversions adjacent to the break sites. It is postulated that the disappearance of chromatid breaks with time results from the completion of such rearrangements, rather than from the rejoining of DSB. Elevated frequencies of chromatid breaks occur in irradiated cells with defects in both nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathways, however there is little evidence of a correlation between reduced DSB rejoining and disappearance of chromatid breaks. Moreover, at least one treatment which abrogates the disappearance of chromatid breaks with time leaves DSB rejoining unaffected. The I-SceI DSB system holds considerable promise for the elucidation of these mechanisms, although the break frequency is relatively low in the cell lines so far derived. Techniques to study and improve such systems are under way in different cell lines. Clearly, much remains to be done to clarify the mechanisms involved in chromatid breakage, but the experimental models are becoming available with which we can begin to answer some of the key questions. Copyright 2003 S. Karger AG, Basel

Medicine in the Encyclopédie (1751-1780) of Diderot and d'Alembert.

PubMed

De Santo, Natale G; Bisaccia, Carmela; Cirillo, Massimo; Richet, Gabriel

2011-01-01

On July 1, 1751, the royal Parisian printer Le Breton published the first volume of the Encyclopédie of Diderot and d'Alembert, a rational dictionary, in folio and in alphabetical order, sold by subscription. The whole work was completed in 1780 (a total of 35 volumes, of which 12 were of illustrations, 4 of supplements and 2 of indices). In 1782 it was followed by the Encyclopédie méthodique, printed by Panckoucke, which ended in 1832 with volume number 166. The frontispiece of the first volume, designed by Charles-Nicolas Cochin Jr. and engraved by Benoît-Louis Prévost showed the columns of an Ionic temple where the Truth appears between Reason and Philosophy. Reason is shown trying to break the veil of Truth, and Philosophy trying to embellish it. Below are the philosophers, their eyes fixed on Truth. Theology is on his knees with his back facing Truth, and seems to receive light from the top. The subsequent chain of figures depicts Memory, Ancient History, Modern History, Geometry, Astronomy and Physics. Below are Optics, Botany, Chemistry and Agriculture. On the bottom line one finds the representatives of arts and professions derived from science. In a 42-page preface ("Discours préliminaire") d'Alembert discussed the path to new knowledge as one "based on what we receive through senses. Ideas depend on senses." The medical collaborators were, or became, famous. Medicine was considered to be rooted in experiment, in patients and in measurements. Functions started to be described with numbers. It was the birth of determinism which was later reinforced by Magendie and Claude Bernard. Albrecht Haller, president of the Academy of Science at Göttingen, as well as a member of all European academies, wrote seminal entries. New accurate definitions appeared for life, disease, death, infections, plague, epidemics, hygiene, fevers and edema. Semiology, the study of signs, became the visible explanation of deranged function, diagnosis and prognosis.

Adaptive Dose Painting by Numbers for Head-and-Neck Cancer

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

Duprez, Frederic, E-mail: frederic.duprez@ugent.be; De Neve, Wilfried; De Gersem, Werner

Purpose: To investigate the feasibility of adaptive intensity-modulated radiation therapy (IMRT) using dose painting by numbers (DPBN) for head-and-neck cancer. Methods and Materials: Each patient's treatment used three separate treatment plans: fractions 1-10 used a DPBN ([{sup 18}-F]fluoro-2-deoxy-D-glucose positron emission tomography [{sup 18}F-FDG-PET]) voxel intensity-based IMRT plan based on a pretreatment {sup 18}F-FDG-PET/computed tomography (CT) scan; fractions 11-20 used a DPBN plan based on a {sup 18}F-FDG-PET/CT scan acquired after the eighth fraction; and fractions 21-32 used a conventional (uniform dose) IMRT plan. In a Phase I trial, two dose prescription levels were tested: a median dose of 80.9 Gymore » to the high-dose clinical target volume (CTV{sub highdose}) (dose level I) and a median dose of 85.9 Gy to the gross tumor volume (GTV) (dose level II). Between February 2007 and August 2009, 7 patients at dose level I and 14 patients at dose level II were enrolled. Results: All patients finished treatment without a break, and no Grade 4 acute toxicity was observed. Treatment adaptation (i.e., plans based on the second {sup 18}F-FDG-PET/CT scan) reduced the volumes for the GTV (41%, p = 0.01), CTV{sub highdose} (18%, p = 0.01), high-dose planning target volume (14%, p = 0.02), and parotids (9-12%, p < 0.05). Because the GTV was much smaller than the CTV{sub highdose} and target adaptation, further dose escalation at dose level II resulted in less severe toxicity than that observed at dose level I. Conclusion: To our knowledge, this represents the first clinical study that combines adaptive treatments with dose painting by numbers. Treatment as described above is feasible.« less

Transport and mixing of a volume of fluid in a complex geometry

NASA Astrophysics Data System (ADS)

Gavelli, Filippo

This work presents the results of the experimental investigation of an entire sequence of events, leading to an unwanted injection of boron-depleted water into the core of a PWR. The study is subdivided into three tasks: the generation of a dilute volume in the primary system, its transport to the core, and the mixing encountered along the path. Experiments conducted at the University of Maryland (UM) facility show that, during a Small-Break LOCA transient, volumes of dilute coolant are segregated in the system, by means of phase-separating energy transport from the core to the steam generators (Boiler Condenser Mode). Two motion-initiating mechanisms are considered: the resumption of natural circulation during the recovery of the primary liquid inventory, and the reactor coolant pump startup under BCM conditions. During the inventory recovery, various phenomena are observed, that contribute to the mixing of the dilute volumes prior to the resumption of flow. The pump activation, instead, occurs in a stagnant system, therefore, no mixing of the unborated liquid has occurred. Since an unmixed slug has the potential for a larger reactivity excursion than a partially mixed one, the pump-initiated flow resumption represents the worst-case scenario. The impulse - response method is applied, for the first time, to the problem of mixing in the downcomer. This allows to express the mixing in terms of two parameters, the dispersion number and the residence time, characteristics of the flow distribution in the complex annular geometry. Other important results are obtained from the analysis of the experimental data with this procedure. It is shown that the turbulence generated by the pump impeller has a significant impact on the overall mixing. Also, the geometric discontinuities in the downcomer (in particular, the gap enlargement below the cold leg elevation) are shown to be the cause of vortex structures that highly enhance the mixing process.

Prediction of guided wave scattering by defects in rails using numerical modelling

NASA Astrophysics Data System (ADS)

Long, Craig S.; Loveday, Philip W.

2014-02-01

A guided wave based monitoring system for welded freight rail, has previously been developed. The current arrangement consists of alternating transmit and receive stations positioned roughly 1 km apart, and is designed to reliably detect complete breaks in a rail. Current research efforts are focused on extending this system to include a pulse-echo mode of operation in order to detect, locate, monitor and possibly characterize damage, before a complete break occurs. For monitoring and inspection applications, it is beneficial to be able to distinguish between scattering defects which do not represent damage (such as welds) and cracks which could result in rail breaks. In this paper we investigate the complex interaction between selected propagating modes and various weld and crack geometries in an attempt to relate scattering behaviour to defect geometry. An efficient hybrid method is employed which models the volume containing the defect with conventional solid finite elements, while the semi-infinite incoming and outgoing waveguides are accounted for using the SAFE method. Four candidate modes, suitable for long range propagation, are identified and evaluated. A weighted average reflection coefficient is used as a measure to quantify mode conversion between these four modes, and results are represented graphically in the form of reflection maps. The results show that it should be possible to distinguish between a large crack in the crown of the rail and a weld. We also show that there may be difficulties associated with reliably identifying cracks in the web as well as cracks in the crown which occur at a thermite weld. We suspect that it will be difficult to detect damage in the foot of the rail.

A two-way nested simulation of the oceanic circulation in the Southwestern Atlantic

NASA Astrophysics Data System (ADS)

Combes, Vincent; Matano, Ricardo P.

2014-02-01

This article presents the results of a high-resolution (1/12°), two-way nested simulation of the oceanic circulation in the southwestern Atlantic region. A comparison between the model results and extant observations indicates that the nested model has skill in reproducing the best-known aspects of the regional circulation, e.g., the volume transport of the ACC, the latitudinal position of the BMC, the shelf break upwelling of Patagonia, and the Zapiola Anticyclone. Sensitivity experiments indicate that the bottom stress parameterization significantly impacts the mean location of the Brazil/Malvinas Confluence and the transport of the Zapiola Anticyclone. The transport of the Brazil Current strengthens during the austral summer and weakens during the austral winter. These variations are driven by the wind stress curl over the southwestern Atlantic. The variations of the transport of the Malvinas Current are out of phase with those of the Brazil Current. Most of the seasonal variability of this current is concentrated in the offshore portion of the jet, the inshore portion has a weak seasonality that modulates the magnitude of the Patagonian shelf break upwelling. Using passive tracers we show that most of the entrainment of deep waters into the shelf occurs in the southernmost portion of the Patagonian shelf and along the inshore boundary of the Brazil Current. Shelf waters are preferentially detrained near the Brazil/Malvinas Confluence. Consistent with previous studies, our simulation also shows that south of ˜42°S the Malvinas Current is composed of two jets, which merge near 42°S to form a single jet farther north.

Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

NASA Astrophysics Data System (ADS)

Gran, K. B.

2015-12-01

Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a series of inset terraces within the valley. The importance of sand on channel behavior thus extends beyond transport rates, affecting the depth of incision and volume of material excavated during a rainy to dry season transition.

A conservation paradox in the Great Basin—Altering sagebrush landscapes with fuel breaks to reduce habitat loss from wildfire

USGS Publications Warehouse

Shinneman, Douglas J.; Aldridge, Cameron L.; Coates, Peter S.; Germino, Matthew J.; Pilliod, David S.; Vaillant, Nicole M.

2018-03-15

Interactions between fire and nonnative, annual plant species (that is, “the grass/fire cycle”) represent one of the greatest threats to sagebrush (Artemisia spp.) ecosystems and associated wildlife, including the greater sage-grouse (Centrocercus urophasianus). In 2015, U.S. Department of the Interior called for a “science-based strategy to reduce the threat of large-scale rangeland fire to habitat for the greater sage-grouse and the sagebrush-steppe ecosystem.” An associated guidance document, the “Integrated Rangeland Fire Management Strategy Actionable Science Plan,” identified fuel breaks as high priority areas for scientific research. Fuel breaks are intended to reduce fire size and frequency, and potentially they can compartmentalize wildfire spatial distribution in a landscape. Fuel breaks are designed to reduce flame length, fireline intensity, and rates of fire spread in order to enhance firefighter access, improve response times, and provide safe and strategic anchor points for wildland fire-fighting activities. To accomplish these objectives, fuel breaks disrupt fuel continuity, reduce fuel accumulation, and (or) increase plants with high moisture content through the removal or modification of vegetation in strategically placed strips or blocks of land.Fuel breaks are being newly constructed, enhanced, or proposed across large areas of the Great Basin to reduce wildfire risk and to protect remaining sagebrush ecosystems (including greater sage-grouse habitat). These projects are likely to result in thousands of linear miles of fuel breaks that will have direct ecological effects across hundreds of thousands of acres through habitat loss and conversion. These projects may also affect millions of acres indirectly because of edge effects and habitat fragmentation created by networks of fuel breaks. Hence, land managers are often faced with a potentially paradoxical situation: the need to substantially alter sagebrush habitats with fuel breaks to ultimately reduce a greater threat of their destruction from wildfire. However, there is relatively little published science that directly addresses the ability of fuel breaks to influence fire behavior in dryland landscapes or that addresses the potential ecological effects of the construction and maintenance of fuel breaks on sagebrush ecosystems and associated wildlife species.This report is intended to provide an initial assessment of both the potential effectiveness of fuel breaks and their ecological costs and benefits. To provide this assessment, we examined prior studies on fuel breaks and other scientific evidence to address three crucial questions: (1) How effective are fuel breaks in reducing or slowing the spread of wildfire in arid and semi-arid shrubland ecosystems? (2) How do fuel breaks affect sagebrush plant communities? (3) What are the effects of fuel breaks on the greater sage-grouse, other sagebrush obligates, and sagebrush-associated wildlife species? We also provide an overview of recent federal policies and management directives aimed at protecting remaining sagebrush and greater sage-grouse habitat; describe the fuel conditions, fire behavior, and fire trends in the Great Basin; and suggest how scientific inquiry and management actions can improve our understanding of fuel breaks and their effects in sagebrush landscapes.

Quantification of surface water volume changes in the Mackenzie Delta using satellite multi-mission data

NASA Astrophysics Data System (ADS)

Normandin, Cassandra; Frappart, Frédéric; Lubac, Bertrand; Bélanger, Simon; Marieu, Vincent; Blarel, Fabien; Robinet, Arthur; Guiastrennec-Faugas, Léa

2018-02-01

Quantification of surface water storage in extensive floodplains and their dynamics are crucial for a better understanding of global hydrological and biogeochemical cycles. In this study, we present estimates of both surface water extent and storage combining multi-mission remotely sensed observations and their temporal evolution over more than 15 years in the Mackenzie Delta. The Mackenzie Delta is located in the northwest of Canada and is the second largest delta in the Arctic Ocean. The delta is frozen from October to May and the recurrent ice break-up provokes an increase in the river's flows. Thus, this phenomenon causes intensive floods along the delta every year, with dramatic environmental impacts. In this study, the dynamics of surface water extent and volume are analysed from 2000 to 2015 by combining multi-satellite information from MODIS multispectral images at 500 m spatial resolution and river stages derived from ERS-2 (1995-2003), ENVISAT (2002-2010) and SARAL (since 2013) altimetry data. The surface water extent (permanent water and flooded area) peaked in June with an area of 9600 km2 (±200 km2) on average, representing approximately 70 % of the delta's total surface. Altimetry-based water levels exhibit annual amplitudes ranging from 4 m in the downstream part to more than 10 m in the upstream part of the Mackenzie Delta. A high overall correlation between the satellite-derived and in situ water heights (R > 0.84) is found for the three altimetry missions. Finally, using altimetry-based water levels and MODIS-derived surface water extents, maps of interpolated water heights over the surface water extents are produced. Results indicate a high variability of the water height magnitude that can reach 10 m compared to the lowest water height in the upstream part of the delta during the flood peak in June. Furthermore, the total surface water volume is estimated and shows an annual variation of approximately 8.5 km3 during the whole study period, with a maximum of 14.4 km3 observed in 2006. The good agreement between the total surface water volume retrievals and in situ river discharges (R = 0.66) allows for validation of this innovative multi-mission approach and highlights the high potential to study the surface water extent dynamics.

Gamma-Ray Burst Jet Breaks Revisited

NASA Astrophysics Data System (ADS)

Wang, Xiang-Gao; Zhang, Bing; Liang, En-Wei; Lu, Rui-Jing; Lin, Da-Bin; Li, Jing; Li, Long

2018-06-01

Gamma-ray Burst (GRB) collimation has been inferred with the observations of achromatic steepening in GRB light curves, known as jet breaks. Identifying a jet break from a GRB afterglow light curve allows a measurement of the jet opening angle and true energetics of GRBs. In this paper, we re-investigate this problem using a large sample of GRBs that have an optical jet break that is consistent with being achromatic in the X-ray band. Our sample includes 99 GRBs from 1997 February to 2015 March that have optical and, for Swift GRBs, X-ray light curves that are consistent with the jet break interpretation. Out of the 99 GRBs we have studied, 55 GRBs are found to have temporal and spectral behaviors both before and after the break, consistent with the theoretical predictions of the jet break models, respectively. These include 53 long/soft (Type II) and 2 short/hard (Type I) GRBs. Only 1 GRB is classified as the candidate of a jet break with energy injection. Another 41 and 3 GRBs are classified as the candidates with the lower and upper limits of the jet break time, respectively. Most jet breaks occur at 90 ks, with a typical opening angle θj = (2.5 ± 1.0)°. This gives a typical beaming correction factor {f}b-1∼ 1000 for Type II GRBs, suggesting an even higher total GRB event rate density in the universe. Both isotropic and jet-corrected energies have a wide span in their distributions: log(Eγ,iso/erg) = 53.11 with σ = 0.84 log(EK,iso/erg) = 54.82 with σ = 0.56 log(Eγ/erg) = 49.54 with σ = 1.29 and log(EK/erg) = 51.33 with σ = 0.58. We also investigate several empirical correlations (Amati, Frail, Ghirlanda, and Liang–Zhang) previously discussed in the literature. We find that in general most of these relations are less tight than before. The existence of early jet breaks and hence small opening angle jets, which were detected in the Swfit era, is most likely the source of scatter. If one limits the sample to jet breaks later than 104 s, the Liang–Zhang relation remains tight and the Ghirlanda relation still exists. These relations are derived from Type II GRBs, and Type I GRBs usually deviate from them.

A Preliminary Investigation of Caffeinated Alcohol Use During Spring Break.

PubMed

Linden-Carmichael, Ashley N; Lau-Barraco, Cathy

2016-06-06

Caffeinated alcoholic beverages (e.g., Red Bull and vodka) are popular but associated with negative consequences. CABs may be particularly popular during Spring Break, a potentially risky social event. We aimed to identify the prevalence of Spring Break caffeinated alcohol use, determine how caffeinated alcohol use Spring Break drinking habits differ from usual, and examine the association between Spring Break caffeinated alcohol use and alcohol-related problems. Data were collected from 95 college students during March of 2013 and 2014. Students completed questionnaires of their alcohol and caffeinated alcohol use before and during Spring Break and Spring Break alcohol-related problems. Approximately 54% of students used caffeinated alcohol during Spring Break. Spring Break caffeinated alcohol use was associated with more alcohol-related problems, even after controlling for other alcohol consumed and Spring Break vacation status. Caffeinated alcoholic beverages are commonly consumed during Spring Break and their use uniquely predicted harms. Prevention efforts placed on caffeinated alcoholic beverage users may be helpful in reducing Spring Break-related harms.

The influence of renewable and non-renewable energy consumption and real income on CO2 emissions in the USA: evidence from structural break tests.

PubMed

Dogan, Eyup; Ozturk, Ilhan

2017-04-01

The objective of this study is to explore the influence of the real income (GDP), renewable energy consumption and non-renewable energy consumption on carbon dioxide (CO 2 ) emissions for the United States of America (USA) in the environmental Kuznets curve (EKC) model for the period 1980-2014. The Zivot-Andrews unit root test with a structural break and the Clemente-Montanes-Reyes unit root test with a structural break report that the analyzed variables become stationary at first-differences. The Gregory-Hansen cointegration test with a structural break and the bounds testing for cointegration in the presence of a structural break show CO 2 emissions, the real income, the quadratic real income, renewable and non-renewable energy consumption are cointegrated. The long-run estimates obtained from the ARDL model indicate that increases in renewable energy consumption mitigate environmental degradation whereas increases in non-renewable energy consumption contribute to CO 2 emissions. In addition, the EKC hypothesis is not valid for the USA. Since we use time-series econometric approaches that account for structural break in the data, findings of this study are robust, reliable and accurate. The US government is advised to put more weights on renewable sources in energy mix, to support and encourage the use and adoption of renewable energy and clean technologies, and to increase the public awareness of renewable energy for lower levels of emissions.

Large-scale Vortex Generation and Evolution in Short-crested Isolated Wave Breaking

NASA Astrophysics Data System (ADS)

Derakhti, M.; Kirby, J. T., Jr.

2016-12-01

Peregrine (1999), in discussing the effect of localization of wave energy dissipation as a generation mechanism for vorticity at the scale of individual waves, spurred a wave of study of vorticity dynamics and mixing processes in the wave-driven ocean. In deep water, the limited depth of penetration of breaking effects leads to the conceptual forcing of a "smoke-ring" resulting from the localized cross-section of impulsive forcing (Pizzo and Melville, 2013). In shallow water, depth limitations favor the generation of a quasi-two-dimensional field of vertical vortex structures, with a resulting inverse cascade of energy to low wavenumbers and the evolution of flows such as transient rip currents (Johnson and Pattiaratchi, 2006). In this study, we are examining a more detailed picture of the vorticity field evolving during a localized breaking event, with particular interest in the span from deep water to shallow water, with special attention to the transition from weak to strong bottom control. Using an LES/VOF model (Derakhti and Kirby, 2014), we examine the evolution of coherent vortex structures whose initial scales are determined by the width of the breaking region, and are much larger than the locally-controlled reverse horseshoe structures seen in typical studies of along-crest uniform breaking. We study the persistence of three-dimensionality of these structures and their contribution to the development of depth-integrated vertical vorticity, and comment on the suitability of 2D or quasi-3D models to represent nearshore flow fields.

Dykes as Tracers of Continental Break-up: Argon Geochronology of Mesozoic Flood Basalts of Western Dronning Maud Land, Antarctica

NASA Astrophysics Data System (ADS)

Fazel, A.; Kelley, S. P.; Leat, P. T.; Hawkesworth, C.

2003-04-01

The British Antarctic Survey MAMOG Project (Magmatism as A Monitor Of Gondwana break up processes) is investigating the mantle processes that resulted in the eruption of the Karoo-Dronning Maud Land CFB suite and its importance in our understanding of the initial stages of Gondwana break-up. One of the problems of understanding the 180Ma continental flood basalts is knowing their precise age. Since they are erupted through more ancient (1000Ma) rocks we have to use the Ar-Ar dating technique to determine whether they are related to the continental break-up or are part of some older event. In addition, we have analysed the chemistry of the dykes and can relate them to several chemical types, the challenge is to test if dykes with similar chemistry all erupted at the same time. It has been suggested that many of the Jurassic dykes in western DML fed the CFB suite that is higher in the volcanic pile. We have found dykes of different ages in the Kirwanveggen and Ahlmannryggen regions of western DML. Although more work needs to be done, we now have mounting evidence to suggest that episodes of chemically similar magmatism in DML stretched from 1000-180Ma with some events separated by hundreds of millions of years implying a lithospheric mantle control on magma composition. The precise ages for the dykes are slightly younger than the accepted ages for the South African Karoo province. In addition to determining the ages of dyke intrusions, a high spatial resolution UV laser has been used to measure argon loss from diorite host rocks adjacent to the dykes. Progressive heating of the country rock during magma emplacement causes argon loss. Thermal modelling of the dykes will allow us to differentiate between various heat loss mechanisms and give an indication of the style, volume and rapidity of magma flow through the dyke. The UV results have shown that some of the dykes were active for long periods probably feeding the surface lava eruptions.

Effect of breaking up sedentary time with callisthenics on endothelial function.

PubMed

Carter, Sophie E; Gladwell, Valerie F

2017-08-01

Periods of prolonged sitting impairs endothelial function in lower limb conduit arteries, which is attenuated with physical activity breaks. The effect of activity breaks on upper limb arteries has not been examined. This study assessed changes in brachial artery endothelial function following either a prolonged sitting period or breaking up this sedentary time by performing sets of callisthenics exercises. Ten healthy participants (6 men) completed 2 conditions in a counterbalanced order: (a) 1-h 26-min sitting, or (b) breaking up this period every 20 min by performing a set of 5 callisthenics exercises. Brachial artery endothelial function was assessed via ultrasound using the flow-mediated dilation (FMD) technique prior to and following each condition, while brachial shear rate (SR) was acquired after each set of callisthenics. There was no significant change in FMD over time (P = 0.09) or between conditions (P = 0.12). Compared to sitting, brachial SR increased following each set of callisthenics, with a significant difference after the third break (Sit: 33.94 ± 12.79 s -1 ; Callisthenics: 57.16 ± 30.48 s -1 , P = 0.02). Alterations in SR in the upper limbs suggest callisthenics may be an effective intervention to break up sedentary time and attenuate the potentially deleterious effects of prolonged sitting on cardiovascular health.

Large-wave simulation of spilling breaking and undertow current over constant slope beach

NASA Astrophysics Data System (ADS)

Dimas, Athanassios; Kolokythas, Gerasimos; Dimakopoulos, Aggelos

2011-11-01

The three-dimensional, free-surface flow, developing by the propagation of nonlinear breaking waves over a constant slope bed, is numerically simulated. The main objective is to investigate the effect of spilling breaking on the characteristics of the induced undertow current by performing large-wave simulations (LWS) based on the numerical solution of the Navier-Stokes equations subject to the fully nonlinear free-surface boundary conditions and the appropriate bottom, inflow and outflow boundary conditions. The equations are properly transformed so that the computational domain becomes time-independent. In the present study, the case of incoming waves with wavelength to inflow depth ratio λ/ d ~ 6.6 and wave steepness H/ λ ~0.025, over bed of slope tan β = 1/35, is investigated. The LWS predicts satisfactorily breaking parameters - height and depth - and wave dissipation in the surf zone, in comparison to experimental data. In the corresponding LES, breaking height and depth are smaller and wave dissipation in the surf zone is weaker. For the undertow current, it is found that it is induced by the breaking process at the free surface, while its strength is controlled by the bed shear stress. Finally, the amplitude of the bed shear stress increases substantially in the breaking zone, becoming up to six times larger than the respective amplitude at the outer region.

Break-up of droplets in a concentrated emulsion flowing through a narrow constriction

NASA Astrophysics Data System (ADS)

Kim, Minkyu; Rosenfeld, Liat; Tang, Sindy; Tang Lab Team

2014-11-01

Droplet microfluidics has enabled a wide range of high throughput screening applications. Compared with other technologies such as robotic screening technology, droplet microfluidics has 1000 times higher throughput, which makes the technology one of the most promising platforms for the ultrahigh throughput screening applications. Few studies have considered the throughput of the droplet interrogation process, however. In this research, we show that the probability of break-up increases with increasing flow rate, entrance angle to the constriction, and size of the drops. Since single drops do not break at the highest flow rate used in the system, break-ups occur primarily from the interactions between highly packed droplets close to each other. Moreover, the probabilistic nature of the break-up process arises from the stochastic variations in the packing configuration. Our results can be used to calculate the maximum throughput of the serial interrogation process. For 40 pL-drops, the highest throughput with less than 1% droplet break-up was measured to be approximately 7,000 drops per second. In addition, the results are useful for understanding the behavior of concentrated emulsions in applications such as mobility control in enhanced oil recovery.

Epidemiology of urban water distribution systems

NASA Astrophysics Data System (ADS)

Bardet, Jean-Pierre; Little, Richard

2014-08-01

Urban water distribution systems worldwide contain numerous old and fragile pipes that inevitably break, flood streets and damage property, and disrupt economic and social activities. Such breaks often present dramatically in temporal clusters as occurred in Los Angeles during 2009. These clustered pipe breaks share many characteristics with human mortality observed during extreme climatological events such as heat waves or air pollution. Drawing from research and empirical studies in human epidemiology, a framework is introduced to analyze the time variations of disruptive pipe breaks that can help water agencies better understand clustered pipe failures and institute measures to minimize the disruptions caused by them. It is posited that at any time, a cohort of the pipes comprising the water distribution system will be in a weakened state due to fatigue and corrosion. This frail cohort becomes vulnerable during normal operations and ultimately breaks due to rapid increase in crack lengths induced by abnormal stressors. The epidemiological harvesting model developed in this paper simulates an observed time series of monthly pipe breaks and has both explanatory and predictive power. It also demonstrates that models from nonengineering disciplines such as medicine can provide improved insights into the performance of infrastructure systems.

The timing of bud break in warming conditions: variation among seven sympatric conifer species from Eastern Canada

NASA Astrophysics Data System (ADS)

Rossi, Sergio; Isabel, Nathalie

2017-11-01

Phenological changes are expected with the ongoing global warming, which could create mismatches in the growth patterns among sympatric species or create synchrony with insect herbivores. In this study, we performed a comparative assessment of the timings of bud break among seven conifer species of Eastern Canada by evaluating seedling development in growth chambers under different temperatures (16, 20 and 24 °C). Bud break occurred earliest in Larix laricina, while Pinus strobus and Pinus resinosa had the latest. Warmer conditions advanced bud break, with the greatest effects being observed at the lower temperatures. Mixed models estimated that one additional degree of temperature produced advancements of 5.3 and 2.1 days at 16 and 20 °C, respectively. The hypothesis of an asynchronous change between species under warming was demonstrated only for the last phenological phases (split buds and exposed shoots), and principally in pines. Abies balsamea showed changes in bud break comparable with the other species analysed, rejecting the hypothesis of mismatches under warmer conditions. The observed non-linear responses of the timings of bud break to warming suggest that the major changes in bud phenology should be expected at the lowest temperatures.

Processing Load Imposed by Line Breaks in English Temporal Wh-Questions

PubMed Central

Hirotani, Masako; Terry, J. Michael; Sadato, Norihiro

2016-01-01

Prosody plays an important role in online sentence processing both explicitly and implicitly. It has been shown that prosodically packaging together parts of a sentence that are interpreted together facilitates processing of the sentence. This applies not only to explicit prosody but also implicit prosody. The present work hypothesizes that a line break in a written text induces an implicit prosodic break, which, in turn, should result in a processing bias for interpreting English wh-questions. Two experiments—one self-paced reading study and one questionnaire study—are reported. Both supported the “line break” hypothesis mentioned above. The results of the self-paced reading experiment showed that unambiguous wh-questions were read faster when the location of line breaks (or frame breaks) matched the scope of a wh-phrase (main or embedded clause) than when they did not. The questionnaire tested sentences with an ambiguous wh-phrase, one that could attach either to the main or the embedded clause. These sentences were interpreted as attaching to the main clause more often than to the embedded clause when a line break appeared after the main verb, but not when it appeared after the embedded verb. PMID:27774072

Vegetable and fruit breaks in Australian primary schools: prevalence, attitudes, barriers and implementation strategies.

PubMed

Nathan, Nicole; Wolfenden, Luke; Butler, Michelle; Bell, Andrew Colin; Wyse, Rebecca; Campbell, Elizabeth; Milat, Andrew J; Wiggers, John

2011-08-01

School-based vegetable and fruit programs can increase student consumption of vegetables and fruit and have been recommended for adoption by Australian schools since 2005. An understanding of the prevalence and predictors of and the barriers to the adoption of school-based vegetable and fruit programs is necessary to maximize their adoption by schools and ensure that the health benefits of such programs to children are realized. The aim of this study was to determine Australian primary school Principals' attitudes and barriers to the implementation of vegetable and fruit breaks; the prevalence of vegetable and fruit breaks in schools and the implementation strategies used and associated with their recommended adoption (daily in at least 80% of classes). A random sample of 384 school Principals completed a 20-min telephone interview. While Principals were highly supportive of vegetable and fruit breaks, only 44% were implementing these to a recommended level. When controlling for all school characteristics, recommended vegetable and fruit break adoption was 1.9 and 2.2 times greater, respectively, in schools that had parent communication strategies and teachers trained. A substantial opportunity exists to enhance the health of children through the adoption of vegetable and fruit breaks in schools.

Comparison of direct DNA strand breaks induced by low energy electrons with different inelastic cross sections

NASA Astrophysics Data System (ADS)

Li, Jun-Li; Li, Chun-Yan; Qiu, Rui; Yan, Cong-Chong; Xie, Wen-Zhang; Zeng, Zhi; Tung, Chuan-Jong

2013-09-01

In order to study the influence of inelastic cross sections on the simulation of direct DNA strand breaks induced by low energy electrons, six different sets of inelastic cross section data were calculated and loaded into the Geant4-DNA code to calculate the DNA strand break yields under the same conditions. The six sets of the inelastic cross sections were calculated by applying the dielectric function method of Emfietzoglou's optical-data treatments, with two different optical datasets and three different dispersion models, using the same Born corrections. Results show that the inelastic cross sections have a notable influence on the direct DNA strand break yields. The yields simulated with the inelastic cross sections based on Hayashi's optical data are greater than those based on Heller's optical data. The discrepancies are about 30-45% for the single strand break yields and 45-80% for the double strand break yields. Among the yields simulated with cross sections of the three different dispersion models, generally the greatest are those of the extended-Drude dispersion model, the second are those of the extended-oscillator-Drude dispersion model, and the last are those of the Ashley's δ-oscillator dispersion model. For the single strand break yields, the differences between the first two are very little and the differences between the last two are about 6-57%. For the double strand break yields, the biggest difference between the first two can be about 90% and the differences between the last two are about 17-70%.

Quantitative, non-invasive imaging of radiation-induced DNA double strand breaks in vivo

PubMed Central

Li, Wenrong; Li, Fang; Huang, Qian; Shen, Jingping; Wolf, Frank; He, Yujun; Liu, Xinjian; Hu, Y. Angela; Bedford, Joel. S.; Li, Chuan-Yuan

2011-01-01

DNA double strand breaks is a major form of DNA damage and a key mechanism through which radiotherapy and some chemotherapeutic agents kill cancer cells. Despite its importance, measuring DNA double strand breaks is still a tedious task that is normally carried out by gel electrophoresis or immunofluorescence staining. Here we report a novel approach to image and quantify DNA double strand breaks in live mammalian cells through bi-fragment luciferase reconstitution. N- and C- terminal fragments of firefly luciferase gene were fused with H2AX and MDC1 genes, respectively. Our strategy was based on the established fact that at the sites of DNA double strand breaks, H2AX protein is phosphoryated and physically associates with the MDC1 protein, thus bringing together N- and C- luciferase fragments and reconstituting luciferase activity. Our strategy allowed serial, non-invasive quantification of DNA double strand breaks in cells irradiated with x-rays and 56Fe ions. Furthermore, it allowed for the evaluation of DNA double strand breaks (DSBs) non-invasively in vivo in irradiated tumors over two weeks. Surprisingly, we detected a second wave of DSB induction in irradiated tumor cells days after radiation exposure in addition to the initial rapid induction of DSBs. We conclude that our new split-luciferase based method for imaging γ-H2AX-MDC1 interaction is a powerful new tool to study DNA double strand break repair kinetics in vivo with considerable advantage for experiments requiring observations over an extended period of time. PMID:21527553

Finite element analysis of stress-breaking attachments on maxillary implant-retained overdentures.

PubMed

Tanino, Fuminori; Hayakawa, Iwao; Hirano, Shigezo; Minakuchi, Shunsuke

2007-01-01

The purpose of this study was to examine the effect of stress-breaking attachments at the connections between maxillary palateless overdentures and implants. Three-dimensional finite element models were used to reproduce an edentulous human maxilla with an implant-retained overdenture. Two-implant models (in the canine tooth positions on both sides) and four-implant models (in the canine and second premolar tooth positions on both sides) were examined. Stress-breaking material connecting the implants and denture was included around each abutment. Axial loads of 100 N were applied to the occlusal surface at the left first molar tooth positions. In each model, the influence of the stress-breaking attachments was compared by changing the elastic modulus from 1 to 3,000 MPa and the thickness of the stress-breaking material from 1 to 3 mm. Maximum stress at the implant-bone interface and stress at the cortical bone surface just under the loading point were calculated. In all models, maximum stress at the implant-bone interface with implants located in the canine tooth position was generated at the peri-implant bone on the loading side. As the elastic modulus of the stress-breaking materials increased, the stress increased at the implant-bone interface and decreased at the cortical bone surface. Moreover, stress at the implant-bone interface with 3-mm-thick stress-breaking material was smaller than that with 1-mm-thick material. Within the limitations of this experiment, stress generated at the implant-bone interface could be controlled by altering the elastic modulus and thickness of the stress-breaking materials.

Evaluation of Structural Factors Potentially Implicated in Acute Lymphoblastic Leukemia: A report of the MIGICCL.

PubMed

López-Sánchez, Dulce María; Méndez-Tenorio, Alfonso; Roacho-Pérez, Jorge Alberto; Rangel-López, Angélica

2016-10-01

Acute lymphoblastic leukemia (ALL) is the most common cancer in the pediatric population; ∼80% of the cases show some translocation. Translocations that result in ALL are due to chromosome breaks. However, the exact mechanisms that cause these breaks have not been well studied. A detailed search of the breakpoints associated with ALL reported in the NCBI database shows that some are concentrated in limited regions of the chromosome, whereas others are scattered throughout. Therefore, the objective of this study was to identify the structural factors involved in chromosomal breaks in ALL. We performed several bioinformatic studies on the sequences where chromosomal breakpoints have been reported in search of rearrangements: areas of high similarity, thermodynamic stability, composition and conformation of the DNA. Certain factors may influence chromosome breaks and are capable of predicting the propensity towards these types of events. These findings may be useful in the design of molecular techniques able to detect these changes in ALL. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Modelling the association of dengue fever cases with temperature and relative humidity in Jeddah, Saudi Arabia-A generalised linear model with break-point analysis.

PubMed

Alkhaldy, Ibrahim

2017-04-01

The aim of this study was to examine the role of environmental factors in the temporal distribution of dengue fever in Jeddah, Saudi Arabia. The relationship between dengue fever cases and climatic factors such as relative humidity and temperature was investigated during 2006-2009 to determine whether there is any relationship between dengue fever cases and climatic parameters in Jeddah City, Saudi Arabia. A generalised linear model (GLM) with a break-point was used to determine how different levels of temperature and relative humidity affected the distribution of the number of cases of dengue fever. Break-point analysis was performed to modelled the effect before and after a break-point (change point) in the explanatory parameters under various scenarios. Akaike information criterion (AIC) and cross validation (CV) were used to assess the performance of the models. The results showed that maximum temperature and mean relative humidity are most probably the better predictors of the number of dengue fever cases in Jeddah. In this study three scenarios were modelled: no time lag, 1-week lag and 2-weeks lag. Among these scenarios, the 1-week lag model using mean relative humidity as an explanatory variable showed better performance. This study showed a clear relationship between the meteorological variables and the number of dengue fever cases in Jeddah. The results also demonstrated that meteorological variables can be successfully used to estimate the number of dengue fever cases for a given period of time. Break-point analysis provides further insight into the association between meteorological parameters and dengue fever cases by dividing the meteorological parameters into certain break-points. Copyright © 2016 Elsevier B.V. All rights reserved.

CORRELATIONS IN HORIZONTAL BRANCH OSCILLATIONS AND BREAK COMPONENTS IN XTE J1701-462 AND GX 17+2

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

Bu, Qing-cui; Chen, Li; Zhang, Liang

2015-01-20

We studied the horizontal branch oscillations (HBO) and the band-limited components observed in the power spectra of the transient neutron star low-mass X-ray binary XTE J1701-462 and the persistent ''Sco-like'' Z source GX 17+2. These two components were studied based on the state-resolved spectra. We found that the frequencies of XTE J1701-462 lie on the known correlations (WK and PBK), showing consistency with other types of X-ray binaries (black holes, atoll sources, and millisecond X-ray pulsars). However, GX 17+2 is shifted from the WK correlation like other typical Z sources. We suggest that the WK/PBK main track forms a boundarymore » that separates persistent sources from transient sources. The characteristic frequencies of break and HBO are independent of accretion rate in both sources, though it depends on spectral models. We also report the energy dependence of the HBO and break frequencies in XTE J1701-462 and how the temporal properties change with spectral state in XTE J1701-462 and GX 17+2. We studied the correlation between rms at the break and the HBO frequency. We suggest that HBO and break components for both sources probably arise from a similar physical mechanism: Comptonization emission from the corona. These two components could be caused by the same kind of oscillation in a corona with uneven density, and they could be generated from different areas of the corona. We further suggest that different proportions of the Comptonization component in the total flux cause the different distribution between GX 17+2 and XTE J1701-462 in the rms{sub break}-rms{sub HBO} diagram.« less

Assessing the benefits of napping and short rest breaks on processing speed in sleep-restricted adolescents.

PubMed

Lim, Julian; Lo, June C; Chee, Michael W L

2017-04-01

Achievement-oriented adolescents often study long hours under conditions of chronic sleep restriction, adversely affecting cognitive function. Here, we studied how napping and rest breaks (interleaved off-task periods) might ameliorate the negative effects of sleep restriction on processing speed. Fifty-seven healthy adolescents (26 female, age = 15-19 years) participated in a 15-day live-in protocol. All participants underwent sleep restriction (5 h time-in-bed), but were then randomized into two groups: one of these groups received a daily 1-h nap opportunity. Data from seven of the study days (sleep restriction days 1-5, and recovery days 1-2) are reported here. The Blocked Symbol Decoding Test, administered once a day, was used to assess time-on-task effects and the effects of rest breaks on processing speed. Controlling for baseline differences, participants who took a nap demonstrated faster speed of processing and greater benefit across testing sessions from practice. These participants were also affected significantly less by time-on-task effects. In contrast, participants who did not receive a nap benefited more from the rest breaks that were permitted between blocks of the test. Our results indicate that napping partially reverses the detrimental effects of sleep restriction on processing speed. However, rest breaks have a greater effect as a countermeasure against poor performance when sleep pressure is higher. These data add to the growing body of evidence showing the importance of sleep for good cognitive functioning in adolescents, and suggest that more frequent rest breaks might be important in situations where sleep loss is unavoidable. © 2017 European Sleep Research Society.

Short-term reversibility of ultrastructural changes in pulmonary capillaries caused by stress failure

NASA Technical Reports Server (NTRS)

Elliott, A. R.; Fu, Z.; Tsukimoto, K.; Prediletto, R.; Mathieu-Costello, O.; West, J. B.

1992-01-01

We previously showed that when the pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to determine whether some of the ultrastructural changes are rapidly reversible when the capillary pressure is reduced. To test this, the Ptm was raised to 52.5 cmH2O for 1 min of blood perfusion and then reduced to 12.5 cmH2O for 3 min of saline-dextran perfusion, followed by intravascular fixation at the same pressure. In another group of animals, the pressure was elevated for 1 min of blood and 3 min of saline-dextran before being reduced. The results were compared with previous studies in which the capillary pressures were maintained elevated at 52.5 cmH2O during the entire procedure. Control studies were also done at sustained low pressures. The results showed that the number of endothelial and epithelial breaks per millimeter and the total fraction area of the breaks were reduced when the pressure was lowered. For example, the number of endothelial breaks per millimeter decreased from 7.1 +/- 2.1 to 2.4 +/- 0.7, and the number of epithelial breaks per millimeter fell from 11.4 +/- 3.7 to 3.4 +/- 0.7. There was evidence that the breaks that closed were those that were initially small and were associated with an intact basement membrane. The results suggest that cells can move along their underlying matrix by rapid disengagement and reattachment of cell adhesion molecules, causing breaks to open or close within minutes.(ABSTRACT TRUNCATED AT 250 WORDS).

Do children report differently from their parents and from observed data? Cross-sectional data on fruit, water, sugar-sweetened beverages and break-time foods.

PubMed

van de Gaar, V M; Jansen, W; van der Kleij, M J J; Raat, H

2016-04-18

Reliable assessment of children's dietary behaviour is needed for research purposes. The aim of this study was (1) to investigate the level of agreement between observed and child-reported break-time food items; and (2) to investigate the level of agreement between children's reports and those of their parents regarding children's overall consumption of fruit, water and sugar-sweetened beverages (SSB). The children in this study were 9-13 years old, attending primary schools in Rotterdam, the Netherlands. Children were observed with respect to foods brought for break-time at school. At the same day, children completed a questionnaire in which they were asked to recall the food(s) they brought to school to consume during break-time. Only paired data (observed and child-reported) were included in the analyses (n = 407 pairs). To determine each child's daily consumption and average amounts of fruit, water and SSB consumed, children and their parents completed parallel questionnaires. Only paired data (parent-reported and child-reported) were included in the analyses (n = 275 pairs). The main statistical measures were level of agreement between break-time foods, fruit, water and SSB; and Intra-class Correlation Coefficients (ICC). More children reported bringing sandwiches and snacks for break-time than was observed (73 % vs 51 % observed and 84 % vs 33 % observed). The overall agreement between observed and child-reported break-time foods was poor to fair, with ICC range 0.16-0.39 (p < 0.05). Children reported higher average amounts of SSB consumed than did their parents (1.3 vs 0.9 L SSB, p < 0.001). Child and parent estimations of the child's water and fruit consumption were similar. ICC between parent and child reports was poor to good (range 0.22-0.62, p < 0.05). Children report higher on amount of break-time foods as compared to observations and children's reports of SSB consumption are higher than those of their parents. Since the level of agreement between the observed break-time foods and that reported by children and the agreement of child's intake between parent and child reports are relatively weak, future studies should focus on improving methods of evaluating children's consumption behaviour or on ways on how to best use and interpret multiple-source dietary intake data. Current Controlled Trials NTR3400 .

HIV-risk behaviours of American spring break vacationers: a case of situational disinhibition?

PubMed

Apostolopoulos, Y; Sönmez, S; Yu, C H

2002-11-01

Young adults are at high risk for acquiring STDs/HIV due primarily to multiple sex partners, unprotected sex, and substance use combined with sexual activity. Contranormative settings--such as the annual spring break vacation--provide ideal conditions for the potentially lethal interaction between alcohol, drugs, and sexual risk-taking. As a steadily growing form of youth travel and characterized by binge drinking, illicit drug use, and unsafe sexual practices, spring break has become a North American institution involving large numbers of travellers. In this study, the theory of interpersonal behaviour was used to explain college students' health-risk behaviours in the context of spring break and pre- and post-spring break surveys were used to examine casual sex and condom use behaviours. Multivariate analyses revealed peer influences, prior experiences with casual sex, alcohol consumption prior to sex, and impulsivity to be significant predictors of casual sex, while impulsivity and condom availability were significant predictors of students' use of condoms during casual sex.

A study of environmental characterization of conventional and advanced aluminum alloys for selection and design. Phase 2: The breaking load test method

NASA Technical Reports Server (NTRS)

Sprowls, D. O.; Bucci, R. J.; Ponchel, B. M.; Brazill, R. L.; Bretz, P. E.

1984-01-01

A technique is demonstrated for accelerated stress corrosion testing of high strength aluminum alloys. The method offers better precision and shorter exposure times than traditional pass fail procedures. The approach uses data from tension tests performed on replicate groups of smooth specimens after various lengths of exposure to static stress. The breaking strength measures degradation in the test specimen load carrying ability due to the environmental attack. Analysis of breaking load data by extreme value statistics enables the calculation of survival probabilities and a statistically defined threshold stress applicable to the specific test conditions. A fracture mechanics model is given which quantifies depth of attack in the stress corroded specimen by an effective flaw size calculated from the breaking stress and the material strength and fracture toughness properties. Comparisons are made with experimental results from three tempers of 7075 alloy plate tested by the breaking load method and by traditional tests of statistically loaded smooth tension bars and conventional precracked specimens.

The HTLV-1 Tax Oncoprotein Represses Ku80 Gene Expression

PubMed Central

Ducu, Razvan I.; Dayaram, Tajhal; Marriott, Susan J.

2011-01-01

The HTLV-I oncoprotein Tax interferes with DNA double strand break repair. Since non-homologous end joining (NHEJ) is a major pathway used to repair DNA double strand breaks we examined the effect of Tax on this pathway, with particular interest in the expression and function of Ku80, a critical component of the NHEJ pathway. Tax expression decreased Ku80 mRNA and protein levels, and repressed transcription from the Ku80 promoter. Conversely, Ku80 mRNA increased following siRNA knockdown of Tax in HTLV-I infected cells. Tax expression was associated with an elevated number of micronuclei and nucleoplasmic bridges, hallmarks of improper DNA double strand break repair. Our studies identified Tax as a transcriptional repressor of Ku80 that correlates with decreased DNA repair function. The reduction of Ku80 transcription by Tax may deplete the cell of an essential DNA break binding protein, resulting in reduced repair of DNA double strand breaks and accumulation genomic mutations. PMID:21571351