Science.gov

Sample records for acceptable response rate

  1. American Recovery and Reinvestment Act of 2009. Interim Report on Customer Acceptance, Retention, and Response to Time-Based Rates from the Consumer Behavior Studies

    SciTech Connect

    Cappers, Peter; Hans, Liesel; Scheer, Richard

    2015-06-01

    Time-based rate programs1, enabled by utility investments in advanced metering infrastructure (AMI), are increasingly being considered by utilities as tools to reduce peak demand and enable customers to better manage consumption and costs. There are several customer systems that are relatively new to the marketplace and have the potential for improving the effectiveness of these programs, including in-home displays (IHDs), programmable communicating thermostats (PCTs), and web portals. Policy and decision makers are interested in more information about customer acceptance, retention, and response before moving forward with expanded deployments of AMI-enabled new rates and technologies. Under the Smart Grid Investment Grant Program (SGIG), the U.S. Department of Energy (DOE) partnered with several utilities to conduct consumer behavior studies (CBS). The goals involved applying randomized and controlled experimental designs for estimating customer responses more precisely and credibly to advance understanding of time-based rates and customer systems, and provide new information for improving program designs, implementation strategies, and evaluations. The intent was to produce more robust and credible analysis of impacts, costs, benefits, and lessons learned and assist utility and regulatory decision makers in evaluating investment opportunities involving time-based rates. To help achieve these goals, DOE developed technical guidelines to help the CBS utilities estimate customer acceptance, retention, and response more precisely.

  2. Survey and online discussion groups to develop a patient-rated outcome measure on acceptability of treatment response in vitiligo

    PubMed Central

    2014-01-01

    Background Vitiligo is a chronic depigmenting skin disorder which affects around 0.5-1% of the world’s population. The outcome measures used most commonly in trials to judge treatment success focus on repigmentation. Patient-reported outcome measures of treatment success are rarely used, although recommendations have been made for their inclusion in vitiligo trials. This study aimed to evaluate the face validity of a new patient-reported outcome measure of treatment response, for use in future trials and clinical practice. Method An online survey to gather initial views on what constitutes treatment success for people with vitiligo or their parents/carers, followed by online discussion groups with patients to reach consensus on what constitutes treatment success for individuals with vitiligo, and how this can be assessed in the context of trials. Participants were recruited from an existing database of vitiligo patients and through posts on the social network sites Facebook and Twitter. Results A total of 202 survey responses were received, of which 37 were excluded and 165 analysed. Three main themes emerged as important in assessing treatment response: a) the match between vitiligo and normal skin (how well it blends in); b) how noticeable the vitiligo is and c) a reduction in the size of the white patches. The majority of respondents said they would consider 80% or more repigmentation to be a worthwhile treatment response after 9 months of treatment. Three online discussion groups involving 12 participants led to consensus that treatment success is best measured by asking patients how noticeable their vitiligo is after treatment. This was judged to be best answered using a 5-point Likert scale, on which a score of 4 or 5 represents treatment success. Conclusions This study represents the first step in developing a patient reported measure of treatment success in vitiligo trials. Further work is now needed to assess its construct validity and responsiveness to

  3. Who accepts responsibility for their transgressions?

    PubMed

    Schumann, Karina; Dweck, Carol S

    2014-12-01

    After committing an offense, transgressors can optimize their chances of reconciling with the victim by accepting responsibility. However, transgressors may be motivated to avoid admitting fault because it can feel threatening to accept blame for harmful behavior. Who, then, is likely to accept responsibility for a transgression? We examined how implicit theories of personality--whether people see personality as malleable (incremental theory) or fixed (entity theory)--influence transgressors' likelihood of accepting responsibility. We argue that incremental theorists may feel less threatened by accepting responsibility because they are more likely to view the situation as an opportunity for them to grow as a person and develop their relationship with the victim. We found support for our predictions across four studies using a combination of real-world and hypothetical offenses, and correlational and experimental methods. These studies therefore identify an important individual difference factor that can lead to more effective responses from transgressors. PMID:25252938

  4. Improving the Response Rate to a Street Survey: An Evaluation of the "But You Are Free to Accept or to Refuse" Technique.

    ERIC Educational Resources Information Center

    Gueguen, Nicolas; Pascual, Alexandre

    2005-01-01

    The "but you are free to accept or to refuse" technique is a compliance procedure in which someone is approached with a request by simply telling him/her that he/she is free to accept or to refuse the request. This semantic evocation leads to increased compliance with the request. Furthermore, in most of the studies in which this technique was…

  5. 48 CFR 46.502 - Responsibility for acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Responsibility for acceptance. 46.502 Section 46.502 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Acceptance 46.502 Responsibility for acceptance. Acceptance...

  6. 105-KE Isolation Barrier Leak Rate Acceptance Test Report

    SciTech Connect

    McCracken, K.J.

    1995-06-14

    This Acceptance Test Report (ATR) contains the completed and signed Acceptance Procedure (ATP) for the 105-KE Isolations Barrier Leak Rate Test. The Test Engineer`s log, the completed sections of the ATP in the Appendix for Repeat Testing (Appendix K), the approved WHC J-7s (Appendix H), the data logger files (Appendices T and U), and the post test calibration checks (Appendix V) are included.

  7. 48 CFR 2446.502 - Responsibility for acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Responsibility for acceptance. 2446.502 Section 2446.502 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT CONTRACT MANAGEMENT QUALITY ASSURANCE Acceptance 2446.502 Responsibility for acceptance....

  8. Constituents of response rates

    PubMed Central

    Pear, Joseph J.; Rector, Brian L.

    1979-01-01

    Response rate and the proportion of time pigeons allocated to a key-pecking activity were measured on several basic types of reinforcement schedules. Reinforcement frequency was varied within each type of basic schedule, and the effects on two constituents of response rate were noted. Propensity, the proportion of time the birds spent on a platform in front of the key, showed very consistent effects as reinforcement frequency varied: in general, it decreased when reinforcement frequency markedly decreased and it increased when reinforcement frequency increased. Speed, key pecks per unit of time spent on the platform, showed inconsistent effects when reinforcement frequency varied. Consequently, response rate showed less consistent effects than did propensity. Cumulative response records demonstrated the existence of several different types of transitions or boundary states between the key-pecking activity and other activities. The types of transitions that occurred between activities depended on both the type of reinforcement schedule and the frequency of reinforcement. The propensity data support the position that general laws of behavior can be based on temporal measures of behavior. The speed data suggest that, if a complete assessment of the dynamic properties of behavior is to be achieved, measures of behavior must incorporate the structural variations in the operant unit. PMID:16812155

  9. PVUSA procurement, acceptance, and rating practices for photovoltaic power plants

    SciTech Connect

    Dows, R.N.; Gough, E.J.

    1995-09-01

    This report is one in a series of PVUSA reports on PVUSA experiences and lessons learned at the demonstration sites in Davis and Kerman, California, and from participating utility host sites. During the course of approximately 7 years (1988--1994), 10 PV systems have been installed ranging from 20 kW to 500 kW. Six 20-kW emerging module technology arrays, five on universal project-provided structures and one turnkey concentrator, and four turnkey utility-scale systems (200 to 500 kW) were installed. PVUSA took a very proactive approach in the procurement of these systems. In the absence of established procurement documents, the project team developed a comprehensive set of technical and commercial documents. These have been updated with each successive procurement. Working closely with vendors after the award in a two-way exchange provided designs better suited for utility applications. This report discusses the PVUSA procurement process through testing and acceptance, and rating of PV turnkey systems. Special emphasis is placed on the acceptance testing and rating methodology which completes the procurement process by verifying that PV systems meet contract requirements. Lessons learned and recommendations are provided based on PVUSA experience.

  10. Evaluation of the Acceptance of Audience Response System by Corporations Using the Technology Acceptance Model

    NASA Astrophysics Data System (ADS)

    Chu, Hsing-Hui; Lu, Ta-Jung; Wann, Jong-Wen

    The purpose of this research is to explore enterprises' acceptance of Audience Response System (ARS) using Technology Acceptance Model (TAM). The findings show that (1) IT characteristics and facilitating conditions could be external variables of TAM. (2) The degree of E-business has positive significant correlation with behavioral intention of employees. (3) TAM is a good model to predict and explain IT acceptance. (4) Demographic variables, industry and firm characteristics have no significant correlation with ARS acceptance. The results provide useful information to managers and ARS providers that (1) ARS providers should focus more on creating different usages to enhance interactivity and employees' using intention. (2) Managers should pay attention to build sound internal facilitating conditions for introducing IT. (3) According to the degree of E-business, managers should set up strategic stages of introducing IT. (4) Providers should increase product promotion and also leverage academic and government to promote ARS.

  11. Sensor response rate accelerator

    DOEpatents

    Vogt, Michael C.

    2002-01-01

    An apparatus and method for sensor signal prediction and for improving sensor signal response time, is disclosed. An adaptive filter or an artificial neural network is utilized to provide predictive sensor signal output and is further used to reduce sensor response time delay.

  12. Notice of inquiry on waste acceptance issues: Response summary

    SciTech Connect

    1995-03-01

    On May 25, 1994, the Department of Energy published a Notice of Inquiry on Waste Acceptance Issues in the Federal Register. Through this Notice of Inquiry, the Department sought to implement the Secretary`s initiative to explore with affected parties various options and methods for sharing the costs related to the financial burden associated with continued on-site storage by eliciting the views of affected parties on: (1) The Department`s preliminary view that it does not have a statutory obligation to begin accepting spent nuclear fuel in 1998 in the absence of an operational repository or other suitable storage facility constructed under the Nuclear Waste Policy Act of 1982, as amended; (2) The need for an interim, away-from-reactor storage facility prior to repository operations; and (3) Options for offsetting, through the Nuclear Waste Fund, a portion of the financial burden that may be incurred by utilities in continuing to store spent nuclear fuel at reactor sites beyond 1998. The Department received a total of 1,111 responses representing 1,476 signatories to this Notice of Inquiry. The responses included submittals from utilities (38 responses); public utility/service commissions and utility regulators (26 responses); Federal, state, and local governments, agencies, and representatives (23 responses); industry and companies (30 responses); public interest groups and other organizations (19 responses); and members of the general public (975 responses).

  13. Acceptance test procedure for the 105-KW isolation barrier leak rate

    SciTech Connect

    McCracken, K.J.

    1995-05-19

    This acceptance test procedure shall be used to: First establish a basin water loss rate prior to installation of the two isolation barriers between the main basin and the discharge chute in K-Basin West. Second, perform an acceptance test to verify an acceptable leakage rate through the barrier seals. This Acceptance Test Procedure (ATP) has been prepared in accordance with CM-6-1 EP 4.2, Standard Engineering Practices.

  14. Influence of UAS Pilot Communication and Execution Delay on Controller's Acceptability Ratings of UAS-ATC Interactions

    NASA Technical Reports Server (NTRS)

    Vu, Kim-Phuong L.; Morales, Gregory; Chiappe, Dan; Strybel, Thomas Z.; Battiste, Vernol; Shively, Jay; Buker, Timothy J

    2013-01-01

    Successful integration of UAS in the NAS will require that UAS interactions with the air traffic management system be similar to interactions between manned aircraft and air traffic management. For example, UAS response times to air traffic controller (ATCo) clearances should be equivalent to those that are currently found to be acceptable with manned aircraft. Prior studies have examined communication delays with manned aircraft. Unfortunately, there is no analogous body of research for UAS. The goal of the present study was to determine how UAS pilot communication and execution delays affect ATCos' acceptability ratings of UAS pilot responses when the UAS is operating in the NAS. Eight radar-certified controllers managed traffic in a modified ZLA sector with one UAS flying in it. In separate scenarios, the UAS pilot verbal communication and execution delays were either short (1.5 s) or long (5 s) and either constant or variable. The ATCo acceptability of UAS pilot communication and execution delays were measured subjectively via post trial ratings. UAS verbal pilot communication delay, were rated as acceptable 92% of the time when the delay was short. This acceptability level decreased to 64% when the delay was long. UAS pilot execution delay had less of an influence on ATCo acceptability ratings in the present stimulation. Implications of these findings for UAS in the NAS integration are discussed.

  15. Effect of Repeated Evaluation and Repeated Exposure on Acceptability Ratings of Sentences

    ERIC Educational Resources Information Center

    Zervakis, Jennifer; Mazuka, Reiko

    2013-01-01

    This study investigated the effect of repeated evaluation and repeated exposure on grammatical acceptability ratings for both acceptable and unacceptable sentence types. In Experiment 1, subjects in the Experimental group rated multiple examples of two ungrammatical sentence types (ungrammatical binding and double object with dative-only verb),…

  16. The Interrelationships between Ratings of Speech and Facial Acceptability in Persons with Cleft Palate.

    ERIC Educational Resources Information Center

    Sinko, Garnet R.; Hedrick, Dona L.

    1982-01-01

    Thirty untrained young adult observers rated the speech and facial acceptablity of 20 speakers with cleft palate. The observers were reliable in rating both speech and facial acceptability. Judgments of facial acceptability were generally more positive, suggesting that speech is generally judged more negatively in speakers with cleft palate.…

  17. Online Course Evaluations Response Rates

    ERIC Educational Resources Information Center

    Guder, Faruk; Malliaris, Mary

    2013-01-01

    This paper studies the reasons for low response rates in online evaluations. Survey data are collected from the students to understand factors that might affect student participation in the course evaluation process. When course evaluations were opened to the student body, an email announcement was sent to all students, and a reminder email was…

  18. The interrelationships between ratings of speech and facial acceptability in persons with cleft palate.

    PubMed

    Sinko, G R; Hedrick, D L

    1982-09-01

    This study was conducted to determine (a) if untrained observers could reliably rate the speech and facial acceptability of young adults with clefts of the lip and/or palate; and (b) if there were differences between the ratings of speech acceptability and facial acceptability according to sex of observer, presentation mode, or speaker effect. Thirty untrained young adult observers rated the speech and facial acceptability of 20 speakers with cleft palate using a 7-point bipolar adjective scale. Judgments of speech acceptability were made from an auditory-only stimulus and then from a combined audio-visual stimulus. Judgments of facial acceptability were made from a visual-only stimulus and then from a combined audio-visual stimulus. Multivariate analysis of variance, Pearson product-moment correlation coefficients, and a posteriori multiple range tests were used for data analyses. Results indicated that untrained observers were reliable in rating both speech and facial acceptability (r .65-.97). The effects of speaker and interaction between speaker and presentation mode were significant at .01 levels of confidence. Judgments made of facial acceptability were generally more positive, leading to the conclusion that speech is generally judged more negatively in speakers with cleft palate, at least by untrained observers. The interaction between speech and facial acceptability was not significant.

  19. Sensors for rate responsive pacing

    PubMed Central

    Dell'Orto, Simonetta; Valli, Paolo; Greco, Enrico Maria

    2004-01-01

    Advances in pacemaker technology in the 1980s have generated a wide variety of complex multiprogrammable pacemakers and pacing modes. The aim of the present review is to address the different rate responsive pacing modalities presently available in respect to physiological situations and pathological conditions. Rate adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. A number of activity and metabolic sensors have been proposed and used for rate control. However, all sensors used to optimize pacing rate metabolic demands show typical limitations. To overcome these weaknesses the use of two sensors has been proposed. Indeed an unspecific but fast reacting sensor is combined with a more specific but slower metabolic one. Clinical studies have demonstrated that this methodology is suitable to reproduce normal sinus behavior during different types and loads of exercise. Sensor combinations require adequate sensor blending and cross checking possibly controlled by automatic algorithms for sensors optimization and simplicity of programming. Assessment and possibly deactivation of some automatic functions should be also possible to maximize benefits from the dual sensor system in particular conditions. This is of special relevance in patient whose myocardial contractility is limited such as in subjects with implantable defibrillators and biventricular pacemakers. The concept of closed loop pacing, implementing a negative feedback relating pacing rate and the control signal, will provide new opportunities to optimize dual-sensors system and deserves further investigation. The integration of rate adaptive pacing into defibrillators is the natural consequence of technical evolution. PMID:16943981

  20. Effect of repeated evaluation and repeated exposure on acceptability ratings of sentences.

    PubMed

    Zervakis, Jennifer; Mazuka, Reiko

    2013-12-01

    This study investigated the effect of repeated evaluation and repeated exposure on grammatical acceptability ratings for both acceptable and unacceptable sentence types. In Experiment 1, subjects in the Experimental group rated multiple examples of two ungrammatical sentence types (ungrammatical binding and double object with dative-only verb), and two difficult to process sentence types [center-embedded (2) and garden path ambiguous relative], along with matched grammatical/non-difficult sentences, before rating a final set of experimental sentences. Subjects in the control group rated unrelated sentences during the exposure period before rating the experimental sentences. Subjects in the Experimental group rated both grammatical and ungrammatical sentences as more acceptable after repeated evaluation than subjects in the Control group. In Experiment 2, subjects answered a comprehension question after reading each sentence during the exposure period. Subjects in the experimental group rated garden path and center-embedded (1) sentences as higher in acceptability after comprehension exposure than subjects in the control group. The results are consistent with increased fluency of comprehension being misattributed as a change in acceptability.

  1. Effect of repeated evaluation and repeated exposure on acceptability ratings of sentences.

    PubMed

    Zervakis, Jennifer; Mazuka, Reiko

    2013-12-01

    This study investigated the effect of repeated evaluation and repeated exposure on grammatical acceptability ratings for both acceptable and unacceptable sentence types. In Experiment 1, subjects in the Experimental group rated multiple examples of two ungrammatical sentence types (ungrammatical binding and double object with dative-only verb), and two difficult to process sentence types [center-embedded (2) and garden path ambiguous relative], along with matched grammatical/non-difficult sentences, before rating a final set of experimental sentences. Subjects in the control group rated unrelated sentences during the exposure period before rating the experimental sentences. Subjects in the Experimental group rated both grammatical and ungrammatical sentences as more acceptable after repeated evaluation than subjects in the Control group. In Experiment 2, subjects answered a comprehension question after reading each sentence during the exposure period. Subjects in the experimental group rated garden path and center-embedded (1) sentences as higher in acceptability after comprehension exposure than subjects in the control group. The results are consistent with increased fluency of comprehension being misattributed as a change in acceptability. PMID:23179954

  2. 18 CFR 300.20 - Interim acceptance and review of Bonneville Power Administration rates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... review of Bonneville Power Administration rates. 300.20 Section 300.20 Conservation of Power and Water... Review and Approval § 300.20 Interim acceptance and review of Bonneville Power Administration rates. (a) Opportunity to comment. The Commission will publish in the Federal Register notice of any filing made...

  3. Construct and Predictive Validity of Social Acceptability: Scores From High School Teacher Ratings on the School Intervention Rating Form

    ERIC Educational Resources Information Center

    Harrison, Judith R.; State, Talida M.; Evans, Steven W.; Schamberg, Terah

    2016-01-01

    The purpose of this study was to evaluate the construct and predictive validity of scores on a measure of social acceptability of class-wide and individual student intervention, the School Intervention Rating Form (SIRF), with high school teachers. Utilizing scores from 158 teachers, exploratory factor analysis revealed a three-factor (i.e.,…

  4. 18 CFR 300.20 - Interim acceptance and review of Bonneville Power Administration rates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Interim acceptance and review of Bonneville Power Administration rates. 300.20 Section 300.20 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER...

  5. Acceptable bit-rates for human face identification from CCTV imagery

    NASA Astrophysics Data System (ADS)

    Tsifouti, Anastasia; Triantaphillidou, Sophie; Bilissi, Efthimia; Larabi, Mohamed-Chaker

    2013-01-01

    The objective of this investigation is to produce recommendations for acceptable bit-rates of CCTV footage of people onboard London buses. The majority of CCTV recorders on buses use a proprietary format based on the H.264/AVC video coding standard, exploiting both spatial and temporal redundancy. Low bit-rates are favored in the CCTV industry but they compromise the image usefulness of the recorded imagery. In this context usefulness is defined by the presence of enough facial information remaining in the compressed image to allow a specialist to identify a person. The investigation includes four steps: 1) Collection of representative video footage. 2) The grouping of video scenes based on content attributes. 3) Psychophysical investigations to identify key scenes, which are most affected by compression. 4) Testing of recording systems using the key scenes and further psychophysical investigations. The results are highly dependent upon scene content. For example, very dark and very bright scenes were the most challenging to compress, requiring higher bit-rates to maintain useful information. The acceptable bit-rates are also found to be dependent upon the specific CCTV system used to compress the footage, presenting challenges in drawing conclusions about universal `average' bit-rates.

  6. A Quantitative Assessment of the Factors that Influence Technology Acceptance in Emergency Response

    ERIC Educational Resources Information Center

    Seiter, Thomas C.

    2012-01-01

    Traditional models for studying user acceptance and adoption of technology focused on the factors that identify and tested the relationships forged between the user and the technology in question. In emergency response, implementing technology without user acceptance may affect the safety of the responders and citizenry. Integrating the factors…

  7. Effects of effort on response rate1

    PubMed Central

    Chung, Shin-Ho

    1965-01-01

    Pigeons were trained to peck for food reinforcement, and the minimum effective force for a peck was varied. In a single-key situation, the response rate was unaffected up to a certain force value, beyond which increments caused a proportional decrement in response rate. Transient enhancement and suppression effects were observed following a change in the force requirement. A change from a high force requirement to a low force requirement resulted in a temporary enhancement of response rate above the stable performance level, whereas a change from a low to a high requirement produced a temporary suppression of the rate below the stable rate. In a two-key situation, the response rate on a key with a given force remained unaffected by the force requirement on the other key. When the rate of response was plotted against the required force, the resultant function was remarkably similar to that obtained from the single-key experiment. When the rates of reinforcement on the two keys differed, the decrement in response rate produced by an increase in the force requirement was proportionally greater on the key with the lower rate of reinforcement. PMID:14266505

  8. Pages from a Sociometric Notebook: An Analysis of Nomination and Rating Scale Measures of Acceptance, Rejection, and Social Preference.

    ERIC Educational Resources Information Center

    Bukowski, William M.; Sippola, Lorrie; Hoza, Betsy; Newcomb, Andrew F.

    2000-01-01

    Provides a conceptual and empirical analysis of the associations between the fundamental sociometric dimensions of acceptance, rejection, and social preference. Examines whether nomination and rating scale measures index the same constructs. Notes that sociometric ratings measure social preference, but can also yield indicators of acceptance and…

  9. Depressed Adolescents' Pupillary Response to Peer Acceptance and Rejection: The Role of Rumination.

    PubMed

    Stone, Lindsey B; Silk, Jennifer S; Siegle, Greg J; Lee, Kyung Hwa; Stroud, Laura R; Nelson, Eric E; Dahl, Ronald E; Jones, Neil P

    2016-06-01

    Heightened emotional reactivity to peer feedback is predictive of adolescents' depression risk. Examining variation in emotional reactivity within currently depressed adolescents may identify subgroups that struggle the most with these daily interactions. We tested whether trait rumination, which amplifies emotional reactions, explained variance in depressed adolescents' physiological reactivity to peer feedback, hypothesizing that rumination would be associated with greater pupillary response to peer rejection and diminished response to peer acceptance. Twenty currently depressed adolescents (12-17) completed a virtual peer interaction paradigm where they received fictitious rejection and acceptance feedback. Pupillary response provided a time-sensitive index of physiological arousal. Rumination was associated with greater initial pupil dilation to both peer rejection and acceptance, and diminished late pupillary response to peer acceptance trials only. Results indicate that depressed adolescents high on trait rumination are more reactive to social feedback regardless of valence, but fail to sustain cognitive-affective load on positive feedback. PMID:26271345

  10. A monetary incentive increases postal survey response rates for pharmacists

    PubMed Central

    Paul, C.; Walsh, R.; Tzelepis, F.

    2005-01-01

    Background: Achieving acceptable response rates from health care providers via postal questionnaires is an ongoing challenge. The use of monetary incentives is one of the most effective strategies for increasing response rates. However, the effect and cost of such an incentive on retail pharmacists' response rates has not been well studied. Methods: A sample of 700 pharmacies was selected at random from the electronic Yellow Pages in NSW Australia and mailed a brief survey regarding pharmacotherapies and advice for smoking cessation. Half of the sample was randomly allocated to receive an offer of an US$14 gift voucher. Results: The response rates were 65.9% for the voucher group and 53.5% for the no-voucher group. The odds of response from the voucher group was 1.68 (95%CI = 1.23, 2.30) times greater than for the no-voucher group. The cost per additional respondent was US$67.95. The incentive also reduced follow up costs by 10%. Conclusions: A moderately sized monetary incentive is able to achieve a significant increase in response rates for retail pharmacists, thereby reducing potential bias in the sample. PMID:16286502

  11. Development and Validation of the Controller Acceptance Rating Scale (CARS): Results of Empirical Research

    NASA Technical Reports Server (NTRS)

    Lee, Katharine K.; Kerns, Karol; Bone, Randall

    2001-01-01

    The measurement of operational acceptability is important for the development, implementation, and evolution of air traffic management decision support tools. The Controller Acceptance Rating Scale was developed at NASA Ames Research Center for the development and evaluation of the Passive Final Approach Spacing Tool. CARS was modeled after a well-known pilot evaluation rating instrument, the Cooper-Harper Scale, and has since been used in the evaluation of the User Request Evaluation Tool, developed by MITRE's Center for Advanced Aviation System Development. In this paper, we provide a discussion of the development of CARS and an analysis of the empirical data collected with CARS to examine construct validity. Results of intraclass correlations indicated statistically significant reliability for the CARS. From the subjective workload data that were collected in conjunction with the CARS, it appears that the expected set of workload attributes was correlated with the CARS. As expected, the analysis also showed that CARS was a sensitive indicator of the impact of decision support tools on controller operations. Suggestions for future CARS development and its improvement are also provided.

  12. Wireless fetal heart rate monitoring in inpatient full-term pregnant women: testing functionality and acceptability.

    PubMed

    Boatin, Adeline A; Wylie, Blair; Goldfarb, Ilona; Azevedo, Robin; Pittel, Elena; Ng, Courtney; Haberer, Jessica

    2015-01-01

    We tested functionality and acceptability of a wireless fetal monitoring prototype technology in pregnant women in an inpatient labor unit in the United States. Women with full-term singleton pregnancies and no evidence of active labor were asked to wear the prototype technology for 30 minutes. We assessed functionality by evaluating the ability to successfully monitor the fetal heartbeat for 30 minutes, transmit this data to Cloud storage and view the data on a web portal. Three obstetricians also rated fetal cardiotocographs on ease of readability. We assessed acceptability by administering closed and open-ended questions on perceived utility and likeability to pregnant women and clinicians interacting with the prototype technology. Thirty-two women were enrolled, 28 of whom (87.5%) successfully completed 30 minutes of fetal monitoring including transmission of cardiotocographs to the web portal. Four sessions though completed, were not successfully uploaded to the Cloud storage. Six non-study clinicians interacted with the prototype technology. The primary technical problem observed was a delay in data transmission between the prototype and the web portal, which ranged from 2 to 209 minutes. Delays were ascribed to Wi-Fi connectivity problems. Recorded cardiotocographs received a mean score of 4.2/5 (± 1.0) on ease of readability with an interclass correlation of 0.81(95%CI 0.45, 0.96). Both pregnant women and clinicians found the prototype technology likable (81.3% and 66.7% respectively), useful (96.9% and 66.7% respectively), and would either use it again or recommend its use to another pregnant woman (77.4% and 66.7% respectively). In this pilot study we found that this wireless fetal monitoring prototype technology has potential for use in a United States inpatient setting but would benefit from some technology changes. We found it to be acceptable to both pregnant women and clinicians. Further research is needed to assess feasibility of using this

  13. Wireless Fetal Heart Rate Monitoring in Inpatient Full-Term Pregnant Women: Testing Functionality and Acceptability

    PubMed Central

    Boatin, Adeline A.; Wylie, Blair; Goldfarb, Ilona; Azevedo, Robin; Pittel, Elena; Ng, Courtney; Haberer, Jessica

    2015-01-01

    We tested functionality and acceptability of a wireless fetal monitoring prototype technology in pregnant women in an inpatient labor unit in the United States. Women with full-term singleton pregnancies and no evidence of active labor were asked to wear the prototype technology for 30 minutes. We assessed functionality by evaluating the ability to successfully monitor the fetal heartbeat for 30 minutes, transmit this data to Cloud storage and view the data on a web portal. Three obstetricians also rated fetal cardiotocographs on ease of readability. We assessed acceptability by administering closed and open-ended questions on perceived utility and likeability to pregnant women and clinicians interacting with the prototype technology. Thirty-two women were enrolled, 28 of whom (87.5%) successfully completed 30 minutes of fetal monitoring including transmission of cardiotocographs to the web portal. Four sessions though completed, were not successfully uploaded to the Cloud storage. Six non-study clinicians interacted with the prototype technology. The primary technical problem observed was a delay in data transmission between the prototype and the web portal, which ranged from 2 to 209 minutes. Delays were ascribed to Wi-Fi connectivity problems. Recorded cardiotocographs received a mean score of 4.2/5 (± 1.0) on ease of readability with an interclass correlation of 0.81(95%CI 0.45, 0.96). Both pregnant women and clinicians found the prototype technology likable (81.3% and 66.7% respectively), useful (96.9% and 66.7% respectively), and would either use it again or recommend its use to another pregnant woman (77.4% and 66.7% respectively). In this pilot study we found that this wireless fetal monitoring prototype technology has potential for use in a United States inpatient setting but would benefit from some technology changes. We found it to be acceptable to both pregnant women and clinicians. Further research is needed to assess feasibility of using this

  14. Crop Yield Response to Increasing Biochar Rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The benefit or detriment to crop yield from biochar application varies with biochar type/rate, soil, crop, or climate. The objective of this research was to identify yield response of cotton (Gossypium hirsutum L.), corn (Zea mayes L.), and peanut (Arachis hypogaea L.) to hardwood biochar applied at...

  15. Acceptance criteria for determining armed response force size at nuclear power plants

    SciTech Connect

    Not Available

    1983-02-01

    This guidance document contains acceptance criteria to be used in the NRC license review process. It consists of a scored worksheet and guidelines for interpreting the worksheet score that can be used in determining the adequacy of the armed response force size at a nuclear power reactor facility.

  16. 30 CFR 1227.200 - What are a State's general responsibilities if it accepts a delegation?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false What are a State's general responsibilities if it accepts a delegation? 1227.200 Section 1227.200 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE DELEGATION TO STATES...

  17. Fetal Heart Rate Response to Maternal Exercise.

    PubMed

    Monga, Manju

    2016-09-01

    Current guidelines regarding recommended exercise in pregnancy appear consistent with reported research regarding fetal heart changes in response to maternal exercise. Fetal heart rate increases during pregnancy, but maternal exercise appears well tolerated if performed in uncomplicated pregnancies and not in the supine position. Maximal levels of exercise that are well tolerated by the fetus have not yet been well defined; however, recent literature suggests that sustained exercise during pregnancy may have beneficial effects on autonomic control of fetal heart rate and variability that may lead to long-term health benefits. PMID:27388963

  18. Results of an emergency response atmospheric dispersion model comparison using a state accepted statistical protocol

    SciTech Connect

    Ciolek, J.T. Jr.

    1993-10-01

    The Rocky Flats Plant, located approximately 26 km northwest of downtown Denver, Colorado, has developed an emergency response atmospheric dispersion model for complex terrain applications. Plant personnel would use the model, known as the Terrain-Responsive Atmospheric Code (TRAC) (Hodgin 1985) to project plume impacts and provide off-site protective action recommendations to the State of Colorado should a hazardous material release occur from the facility. The Colorado Department of Health (CDH) entered into an interagency agreement with the Rocky Flats Plant prime contractor, EG&G Rocky Flats, and the US Department of Energy to evaluate TRAC as an acceptable emergency response tool. After exhaustive research of similar evaluation processes from other emergency response and regulatory organizations, the interagency committee devised a formal acceptance process. The process contains an evaluation protocol (Hodgin and Smith 1992), descriptions of responsibilities, an identified experimental data set to use in the evaluation, and judgment criteria for model acceptance. The evaluation protocol is general enough to allow for different implementations. This paper explains one implementation, shows protocol results for a test case, and presents results of a comparison between versions of TRAC with different wind Field codes: a two dimensional mass consistent code called WINDS (Fosberg et al. 1976) that has been extended to three dimensions, and a fully 3 dimensional mass conserving code called NUATMOS (Ross and Smith 1987, Ross et al. 1988).

  19. Response rate and reinforcement rate in Pavlovian conditioning.

    PubMed

    Harris, Justin A; Carpenter, Joanne S

    2011-10-01

    Four experiments used delay conditioning of magazine approach in rats to investigate the relationship between the rate of responding, R, to a conditioned stimulus (CS) and the rate, r, at which the CS is reinforced with the unconditioned stimulus (US). Rats were concurrently trained with four variable-duration CSs with different rs, either as a result of differences in the mean CS-US interval or in the proportion of CS presentations that ended with the US. In each case, R was systematically related to r, and the relationship was very accurately characterized by a hyperbolic function, R = Ar/(r +c). Accordingly, the reciprocal of these two variables-response interval, I (= 1/R), and CS-US interval, i (= 1/r) - were related by a simple affine (straight line) transformation, I = mi+b. This latter relationship shows that each increment in the time that the rats had to wait for food produced a linear increment in the time they waited between magazine entries. We discuss the close agreement between our findings and the Matching Law (Herrnstein, 1970) and consider their implications for both associative theories (e.g., Rescorla & Wagner, 1972) and nonassociative theories (Gallistel & Gibbon, 2000) of conditioning. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  20. Building Fluent Performance: Measuring Response Rate and Multiplying Response Opportunities

    ERIC Educational Resources Information Center

    Binder, Carl

    2010-01-01

    Precision teaching emerged from O.R. Lindsley's pristine application of Skinner's natural science of behavior, with a focus on response rate measurement and free operant procedures. When applied with human learners in instructional settings, these first principles led to a series of developments framed in this paper as four kinds of ceilings that…

  1. Causal attribution and affective response as mediated by task performance and self-acceptance.

    PubMed

    Green, T D; Bailey, R C; Zinser, O; Williams, D E

    1994-12-01

    Predictions derived from cognitive consistency theories, self-esteem theories, and ego-serving-bias theory concerning how students would make attributional and affective responses to their academic performance were investigated. 202 university students completed a measure of self-acceptance of their college ability and made attributional and affective responses to an hypothetical examination performance. Analyses showed that students receiving positive feedback perceived greater internal causality and responded with greater positive affect than students receiving negative feedback. Self-acceptance did not moderate the attributions or affective reactions. The results supported the ego-serving-bias theory and provided partial support for self-esteem theory. Findings did not support predictions from cognitive-consistency theory.

  2. The acceptability of climate change in agricultural communities: comparing responses across variability and change.

    PubMed

    Raymond, Christopher M; Spoehr, John

    2013-01-30

    This study examined how the terms used to describe climate change influence landholder acceptability judgements and attitudes toward climate change at the local scale. Telephone surveys were conducted with landholders from viticultural (n = 97) or cereal growing (n = 195) backgrounds in rural South Australia. A variety of descriptive and inferential statistics were used to examine the influence of human-induced climate change and winter/spring drying trend terms on adaptation responses and uncertainties surrounding climate change science. We found that the terms used to describe climate change leads to significant differences in adaptation response and levels of scepticism surrounding climate change in rural populations. For example, those respondents who accepted human induced climate change as a reality were significantly more likely to invest in technologies to sow crops earlier or increase the amount of water stored or harvested on their properties than respondents who accepted the winter/spring drying trend as a reality. The results have implications for the targeting of climate change science messages to both rural landholders and communities of practice involved in climate change adaptation planning and implementation. PMID:23246767

  3. The acceptability of climate change in agricultural communities: comparing responses across variability and change.

    PubMed

    Raymond, Christopher M; Spoehr, John

    2013-01-30

    This study examined how the terms used to describe climate change influence landholder acceptability judgements and attitudes toward climate change at the local scale. Telephone surveys were conducted with landholders from viticultural (n = 97) or cereal growing (n = 195) backgrounds in rural South Australia. A variety of descriptive and inferential statistics were used to examine the influence of human-induced climate change and winter/spring drying trend terms on adaptation responses and uncertainties surrounding climate change science. We found that the terms used to describe climate change leads to significant differences in adaptation response and levels of scepticism surrounding climate change in rural populations. For example, those respondents who accepted human induced climate change as a reality were significantly more likely to invest in technologies to sow crops earlier or increase the amount of water stored or harvested on their properties than respondents who accepted the winter/spring drying trend as a reality. The results have implications for the targeting of climate change science messages to both rural landholders and communities of practice involved in climate change adaptation planning and implementation.

  4. Accepting leadership responsibility: preparing yourself to lead honestly, humanely, and effectively.

    PubMed

    McConnell, Charles R

    2003-01-01

    Many who enter management are ready and willing to accept the benefits of their positions, but not all are readily accepting of the full responsibilities of leadership. All too frequently, modern leadership appears self-serving, with the needs and desires of the leaders taking precedence over the needs of the followers and even the needs of the clients or customers. True leadership, however, should primarily benefit the followers rather than the leader. Leaders lead and followers follow for essentially the same reason, fulfillment of needs, so leaders and followers are fundamentally little different from each other. Every manager at every level has organizational superiors, so every leader is a follower as well. A true leader among managers is one who subordinates personal needs to the organization's needs, places employees well above self in importance, models appropriate behavior for employees, and functions as a facilitator in the employees' continuing efforts to get the necessary work done efficiently and effectively. PMID:14672447

  5. Accepting "total and complete responsibility": new age neo-feminist violence against women.

    PubMed

    Sethna, C

    1992-02-01

    Barry Konikov, a hypnotherapist, of Potentials Unlimited Inc., a Michigan-based company which produces approximately 160 Subliminal Persuasion/Self Hypnosis tapes, promises his listeners miracles. The tapes on premenstrual syndrome, abortion, and sexual abuse were analyzed. The self-hypnosis message by Konikov is dangerous for women, because his antifeminism, misogyny, and patriarchism are couched insidiously within New Age neofeminism. Under therapeutic guidance the woman listener can direct her own transformation to complete mental, physical, and spiritual well-being, and her new and improved self is so empowered as to accept total and complete responsibility to overcome the hurt about menstruation, abortion, or sexual abuse. Growth therapies such as Gestalt, guided fantasies, and bioenergetics undermine women with false promises of power. If women are so powerful, then it is their fault if they got raped, or battered, or if they have not received love, money, and inner peace. While seemingly empowering women to develop a strong sense of personal agency, Konikov ignores the patriarchal structures which intersect his women listeners' experience of menstrual discomfort, abortion, and sexual abuse. Konikov's New Age, neofeminist stance contains 4 stages of healing: responsibility, absolution, forgiveness, and resolution. Accepting responsibility for the wound next leads to absolution, and particularly absolution for men. As an example of absolution, Konikov's woman client-ex-plantation slave accepted her past-life relationship to her husband, absolved him of guild, and decided upon a divorce. The issue of absolution widens into forgiveness in the healing process, whereby Konikov wants women to hypnotize themselves therapy should be to help a woman see how her own power as an individual is inextricably bound to the collective power of women as a group. There is no doubt that the New Age neofeminist stance taken by Konikov on the tapes leaves women profoundly

  6. Mothers' and Fathers' Responsive Problem Solving with Early Adolescents: Do Gender, Shyness, and Social Acceptance Make a Difference?

    ERIC Educational Resources Information Center

    Miller, Scott R.; Brody, Gene H.; Murry, Velma M.

    2010-01-01

    We assessed the extent to which youths' (n = 231) shyness and social acceptance in preadolescence were associated with parents' responsive problem solving 1 year later after controlling for initial levels of parents' problem solving. Teachers (n = 176) completed assessments of youths' shyness and social acceptance, and parents (n = 231 married…

  7. Recruiting faculty with clinical responsibilities: factors that influence a decision to accept an academic position.

    PubMed

    Grauer, Gregory F

    2005-01-01

    The current opportunities for veterinary clinical specialists in private practice and industry have made recruiting and retaining faculty a major focus for most clinical academic departments. To gain a better understanding of the importance of the various factors considered in accepting an academic position, an electronic survey was distributed to newly hired veterinary faculty with clinical responsibilities. The results suggest that the perceived climate and collegiality within the prospective hiring department is the most important factor influencing the decision to accept an academic position. Salary is the second most important factor. Institutional support for the newly hired faculty member and the reputation and quality of the prospective institution rank as more important than the perceived quality of the local community and the geographic location of the institution. The search process and administrative support are the least important factors. There were no differences between the responses of faculty hired into tenure-track positions and those of faculty hired into clinical-track positions. Focusing on the advantages of a collegial environment, enhancing compensation packages, and using creative and flexible appointments may improve faculty recruitment and retention in clinical academic departments.

  8. [Independence, consciously accepted dependency, self-responsibility and shared responsibility as key categories of an ethical analysis of old age].

    PubMed

    Kruse, A

    2005-08-01

    This contribution begins with a brief introduction into some seminal problems of ethics: the search for the essential being of things, the attitude of value consciousness in the context of ethical reflections, and the reflection on models of a 'good life' and on decisions as well as actions in significant moral situations. These introductory statements are illustrated by the example of stoic philosophy. In a second step, independence, consciously accepted dependency, self-responsibility and shared responsibility are discussed as highly significant categories for an ethical analysis of all ages. However these categories must be specified with reference to specific ages. In this contribution, such a specification is carried out for old age focussing on the particular relevance of the four categories for ethical analysis. In a third step, each of the four categories is discussed in detail in the context of basic ethical approaches. In this context, ethical analysis proceeds from the perspectives of the individual, the environment, and the society. Concerning the perspective of the society special interest is offered to societal models of good life in old age which might have an impact on the potential development of a pro-aging culture and shared responsibility in older people. Moreover, these models contribute to older people's ability to use the necessary means of support in cases of dependency and to consciously accept dependency. PMID:16133757

  9. Feedback Functions, Optimization, and the Relation of Response Rate to Reinforcer Rate

    ERIC Educational Resources Information Center

    Soto, Paul L.; McDowell, Jack J.; Dallery, Jesse

    2006-01-01

    The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate…

  10. Item Response Models for Local Dependence among Multiple Ratings

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Su, Chi-Ming; Qiu, Xue-Lan

    2014-01-01

    Ratings given to the same item response may have a stronger correlation than those given to different item responses, especially when raters interact with one another before giving ratings. The rater bundle model was developed to account for such local dependence by forming multiple ratings given to an item response as a bundle and assigning…

  11. 42 CFR 137.285 - Are Self-Governance Tribes required to accept Federal environmental responsibilities to enter...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Federal environmental responsibilities to enter into a construction project agreement? 137.285 Section 137...-Governance Tribes required to accept Federal environmental responsibilities to enter into a construction project agreement? Yes, under section 509 of the Act , Self-Governance Tribes must assume all...

  12. 42 CFR 137.285 - Are Self-Governance Tribes required to accept Federal environmental responsibilities to enter...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Federal environmental responsibilities to enter into a construction project agreement? 137.285 Section 137...-Governance Tribes required to accept Federal environmental responsibilities to enter into a construction project agreement? Yes, under section 509 of the Act , Self-Governance Tribes must assume all...

  13. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... responsibility for determining the acceptability of each equivalent level of safety analysis? 102-80.125 Section 102-80.125 Public Contracts and Property Management Federal Property Management Regulations System... Fire Prevention Equivalent Level of Safety Analysis § 102-80.125 Who has the responsibility...

  14. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... responsibility for determining the acceptability of each equivalent level of safety analysis? 102-80.125 Section 102-80.125 Public Contracts and Property Management Federal Property Management Regulations System... Fire Prevention Equivalent Level of Safety Analysis § 102-80.125 Who has the responsibility...

  15. Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments.

    PubMed

    Wong-McSweeney, D; Woodcock, J S; Peris, E; Waddington, D C; Moorhouse, A T; Redel-Macías, M D

    2016-10-15

    The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure-response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure-response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure-response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure-response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N=321) conducted for the construction of an urban LRT in the United Kingdom. PMID:26875606

  16. Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments.

    PubMed

    Wong-McSweeney, D; Woodcock, J S; Peris, E; Waddington, D C; Moorhouse, A T; Redel-Macías, M D

    2016-10-15

    The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure-response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure-response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure-response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure-response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N=321) conducted for the construction of an urban LRT in the United Kingdom.

  17. A Comparison of Response Rate, Response Time, and Costs of Mail and Electronic Surveys.

    ERIC Educational Resources Information Center

    Shannon, David M.; Bradshaw, Carol C.

    2002-01-01

    Compared response rates, response time, and costs of mail and electronic surveys using a sample of 377 college faculty members. Mail surveys yielded a higher response rate and a lower rate of undeliverable surveys, but response time was longer and costs were higher than for electronic surveys. (SLD)

  18. Individualism, acceptance and differentiation as attitude traits in the public's response to vaccination.

    PubMed

    Velan, Baruch; Boyko, Valentina; Lerner-Geva, Liat; Ziv, Arnona; Yagar, Yaakov; Kaplan, Giora

    2012-09-01

    The attitude of the general public to vaccination was evaluated through a survey conducted on a representative sample of the Israeli population (n = 2,018), in which interviewees were requested to express their standpoints regarding five different vaccination programs. These included: pandemic influenza vaccination, seasonal influenza vaccination, travel vaccines, Human Papilloma Virus vaccine and childhood vaccinations. Analysis of the responses reveal three major attitude traits: a) acceptance, characterized by the opinion that targets should be vaccinated; b) individualism, characterized by the opinion that vaccination should be left to personal choice; and c) differentiation, characterized by the tendency to express different attitudes when addressing different vaccination programs. Interestingly, direct opposition to vaccination was found to be a minor attitude trait in this survey. Groups within the population could be defined according to their tendency to assume these different attitudes as Acceptors, Judicious-acceptors, Differentiators, Soft-individualists, and Hard-individualists. These groups expressed different standpoints on all five vaccination programs as well as on other health recommendations, such as screening for early detection of cancer. Attitude traits could be also correlated, to a certain extent, with actual compliance with vaccination programs. Interestingly, attitudes to vaccination were not correlated with social profiles related to income or education, although younger individuals exhibited higher degrees of individualism and differentiation. Taken together, all this is in accordance with the current social settings, underlining the individual's tendency for critical evaluation and self-stirring. This should be taken into consideration by health authorities involved in vaccination programs.

  19. Individualism, acceptance and differentiation as attitude traits in the public’s response to vaccination

    PubMed Central

    Velan, Baruch; Boyko, Valentina; Lerner-Geva, Liat; Ziv, Arnona; Yagar, Yaakov; Kaplan, Giora

    2012-01-01

    The attitude of the general public to vaccination was evaluated through a survey conducted on a representative sample of the Israeli population (n = 2,018), in which interviewees were requested to express their standpoints regarding five different vaccination programs. These included: pandemic influenza vaccination, seasonal influenza vaccination, travel vaccines, Human Papilloma Virus vaccine and childhood vaccinations. Analysis of the responses reveal three major attitude traits: a) acceptance, characterized by the opinion that targets should be vaccinated; b) individualism, characterized by the opinion that vaccination should be left to personal choice; and c) differentiation, characterized by the tendency to express different attitudes when addressing different vaccination programs. Interestingly, direct opposition to vaccination was found to be a minor attitude trait in this survey. Groups within the population could be defined according to their tendency to assume these different attitudes as Acceptors, Judicious-acceptors, Differentiators, Soft-individualists, and Hard-individualists. These groups expressed different standpoints on all five vaccination programs as well as on other health recommendations, such as screening for early detection of cancer. Attitude traits could be also correlated, to a certain extent, with actual compliance with vaccination programs. Interestingly, attitudes to vaccination were not correlated with social profiles related to income or education, although younger individuals exhibited higher degrees of individualism and differentiation. Taken together, all this is in accordance with the current social settings, underlining the individual's tendency for critical evaluation and self-stirring. This should be taken into consideration by health authorities involved in vaccination programs. PMID:22894959

  20. Feedback functions, optimization, and the relation of response rate to reinforcer rate.

    PubMed

    Soto, Paul L; McDowell, Jack J; Dallery, Jesse

    2006-01-01

    The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate was arranged according to a quadratic equation with a maximum at a unique response rate. The experiment consisted of two phases, during which 6 Long Evans rats lever pressed for food. In the first phase of the experiment, the rats responded on six fixed-interval-plus-quadratic-feedback schedules, and in the second phase the rats responded on three variable-interval-plus-quadratic-feedback schedules. Responding in both phases was inconsistent with a one-to-one relation of response rate to reinforcer rate. Instead, different response rates were obtained at equivalent reinforcer rates. Responding did vary directly with the vertex of the feedback function in both phases, a finding consistent with optimization of reinforcer rate. The present results suggest that the feedback function relating reinforcer rate to response rate imposed by a reinforcement schedule can be an important determinant of behavior. Furthermore, the present experiment illustrates the benefit of arranging feedback functions to investigate assumptions about the variables that control schedule performance.

  1. Methadone Maintenance for HIV Positive and HIV Negative Patients in Kyiv: Acceptability and Treatment Response

    PubMed Central

    Dvoriak, Sergii; Karachevsky, Andrey; Chhatre, Sumedha; Booth, Robert; Metzger, David; Schumacher, Joseph; Chychula, Nina; Pecoraro, Anna; Woody, George

    2014-01-01

    Background With up to 40% of opioid injectors infected with HIV, Ukraine has one of the most concentrated HIV epidemics in the world, mainly due to unsterile injection practices and a historical absence of effective prevention services. Harm reduction programs, including syringe exchange and a small buprenorphine treatment program, were introduced in 2004 and methadone maintenance was allowed in 2007. Despite an initial expansion, by 2009, only 3221 injectors were receiving methadone treatment. A growing body of research on methadone maintenance has found high retention rates with reduction in opioid use and HIV risk behaviors. We report on the acceptability and initial outcome of methadone treatment as a function of HIV status, an issue that has not yet been reported for injectors in Ukraine. Methods Longitudinal observational study of a 12-week course of methadone treatment in 25 HIV+ and 25 HIV− opioid addicted individuals recruited from a harm reduction program and the city AIDS Center. Drug use and HIV risk were assessed at baseline and weeks 4, 8, 12 and 20; all patients were offered continued methadone maintenance in the Kyiv city program at the end of 12 weeks. Results Fifty-four individuals were asked if they were interested in the study and 50, demographically similar to other samples of opioid addicted Ukrainians, agreed to participate. Two died of non-study related causes; the other 48 completed assessments at weeks 4, 8 and 12, and 47 completed followups at week 20. Significant reductions were seen in use of heroin (p<. 0001), other opiates/analgesics (p< 0.0001), and HIV risk behaviors (drug, sex, total; all p <0.0001). All 48 patients chose to continue methadone after the 12-weeks of study medication ended. Unlike most opioid treatment studies, sexual risk was somewhat higher than injecting risk at study intake. Conclusions Methadone maintenance was well accepted by HIV+ and HIV− opioid dependent individuals and has the potential for significant

  2. Diet History Questionnaire: Response Rates/Length of Questionnaire

    Cancer.gov

    Based on pilot study research from about 400 individuals in one study and about 1000 in another, the response rates for the DHQ varied from 70-85%. In both these studies, the DHQ response rates were not statistically different than those from shorter FFQs.

  3. Effect of Mailing Address Style on Survey Response Rate.

    ERIC Educational Resources Information Center

    Cookingham, Frank G.

    This study determined the effect of using mailing labels prepared by a letter-quality computer printer on survey response rate. D. A. Dillman's personalization approach to conducting mail surveys suggests that envelopes with addresses typed directly on them may produce a higher response rate than envelopes with addresses typed on self-adhesive…

  4. Modeling rate sensitivity of exercise transient responses to limb motion.

    PubMed

    Yamashiro, Stanley M; Kato, Takahide

    2014-10-01

    Transient responses of ventilation (V̇e) to limb motion can exhibit predictive characteristics. In response to a change in limb motion, a rapid change in V̇e is commonly observed with characteristics different than during a change in workload. This rapid change has been attributed to a feed-forward or adaptive response. Rate sensitivity was explored as a specific hypothesis to explain predictive V̇e responses to limb motion. A simple model assuming an additive feed-forward summation of V̇e proportional to the rate of change of limb motion was studied. This model was able to successfully account for the adaptive phase correction observed during human sinusoidal changes in limb motion. Adaptation of rate sensitivity might also explain the reduction of the fast component of V̇e responses previously reported following sudden exercise termination. Adaptation of the fast component of V̇e response could occur by reduction of rate sensitivity. Rate sensitivity of limb motion was predicted by the model to reduce the phase delay between limb motion and V̇e response without changing the steady-state response to exercise load. In this way, V̇e can respond more quickly to an exercise change without interfering with overall feedback control. The asymmetry between responses to an incremental and decremental ramp change in exercise can also be accounted for by the proposed model. Rate sensitivity leads to predicted behavior, which resembles responses observed in exercise tied to expiratory reserve volume.

  5. Effects of Population Type on Mail Survey Response Rates and on the Efficacy of Response Enhancers.

    ERIC Educational Resources Information Center

    Green, Kathy E.; And Others

    Experimental studies of response rates to mail surveys were reviewed and differences in response by population type were described. Cases were selected for review if they were experimental studies that manipulated a response enhancement factor. Results suggest significant differences in typical response rates for different populations. Higher…

  6. Heart Rate Response and Lactic Acid Concentration in Squash Players.

    ERIC Educational Resources Information Center

    Beaudin, Paula; And Others

    1978-01-01

    It was concluded that playing squash is an activity that results in heart rate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)

  7. Component duration and relative response rates in multiple schedules.

    NASA Technical Reports Server (NTRS)

    Todorov, J. C.

    1972-01-01

    Pigeons were trained on a multiple variable-interval 30-sec, variable interval 90-sec schedule with each component presented alternately for an equal duration. This duration of exposure was varied from 5 to 300 sec. The rate of response in the variable-interval 30-sec component relative to the rate of response in the variable-interval 90-sec component was studied. Results are plotted and discussed.

  8. Integrating Telemedicine for Disaster Response: Testing the Emergency Telemedicine Technology Acceptance Model

    ERIC Educational Resources Information Center

    Davis, Theresa M.

    2013-01-01

    Background: There is little evidence that technology acceptance is well understood in healthcare. The hospital environment is complex and dynamic creating a challenge when new technology is introduced because it impacts current processes and workflows which can significantly affect patient care delivery and outcomes. This study tested the effect…

  9. Social Acceptance; A Possible Mediator in the Association between Socio-Economic Deprivation and Under-18 Pregnancy Rates?

    ERIC Educational Resources Information Center

    Smith, Debbie Michelle; Roberts, Ron

    2009-01-01

    This study examines the social acceptance of young (under-18) pregnancy by assessing people's acceptance of young pregnancy and abortion in relation to deprivation. A cross-sectional survey design was conducted in two relatively affluent and two relatively deprived local authorities in London (n=570). Contrary to previous findings, participants…

  10. Obtaining Valid Response Rates: Considerations beyond the Tailored Design Method.

    ERIC Educational Resources Information Center

    Huang, Judy Y.; Hubbard, Susan M.; Mulvey, Kevin P.

    2003-01-01

    Reports on the use of the tailored design method (TDM) to achieve high survey response in two separate studies of the dissemination of Treatment Improvement Protocols (TIPs). Findings from these two studies identify six factors may have influenced nonresponse, and show that use of TDM does not, in itself, guarantee a high response rate. (SLD)

  11. An Item Response Unfolding Model for Graphic Rating Scales

    ERIC Educational Resources Information Center

    Liu, Ying

    2009-01-01

    The graphic rating scale, a measurement tool used in many areas of psychology, usually takes a form of a fixed-length line segment, with both ends bounded and labeled as extreme responses. The raters mark somewhere on the line, and the length of the line segment from one endpoint to the mark is taken as the measure. An item response unfolding…

  12. Characterization of Composites Response at High Rates of Deformation

    NASA Technical Reports Server (NTRS)

    Gilat, Amos

    2001-01-01

    The objective of the proposed research is to experimentally study the effect of strain rate on mechanical response (deformation and failure) of IM-7/977-2 carbon fiber/epoxy matrix composites. The experimental data will provide the information needed for the development of a nonlinear, rate dependent deformation and strength model for this material that can subsequently be used in design.

  13. Response rate viewed as engagement bouts: resistance to extinction.

    PubMed

    Shull, Richard L; Gaynor, Scott T; Grimes, Julie A

    2002-05-01

    Rats obtained food pellets by nose poking a lighted key, the illumination of which alternated every 50 s during a session between blinking and steady, signaling either a relatively rich (60 per hour) or relatively lean (15 per hour) rate of reinforcement. During one training condition, all the reinforcers in the presence of the rich-reinforcement signal were response dependent (i.e., a variable-interval schedule); during another condition only 25% were response dependent (i.e., a variable-time schedule operated concurrently with a variable-interval schedule). An extinction session followed each training block. For both kinds of training schedule, and consistent with prior results, response rate was more resistant to extinction in the presence of the rich-reinforcement signal than in the presence of the lean-reinforcement signal. Analysis of interresponse-time distributions from baseline showed that differential resistance to extinction was not related to baseline differences in the rate of initiating response bouts or in the length of bouts. Also, bout-initiation rate (like response rate) was most resistant to extinction in the presence of the rich-reinforcement signal. These results support the proposal of behavioral momentum theory (e.g., Nevin & Grace, 2000) that resistance to extinction in the presence of a discriminative stimulus is determined more by the stimulus-reinforcer (Pavlovian) than by the stimulus-response-reinforcer (operant) contingency.

  14. Effects of methamphetamine on response rate: a microstructural analysis.

    PubMed

    Bennett, J Adam; Hughes, Christine E; Pitts, Raymond C

    2007-06-01

    Key pecking in pigeons was maintained under a multiple random-interval (RI) 1-min, RI 4-min schedule of food presentation. Several doses (0.3-5.6 mg/kg) of methamphetamine were administered, and effects on overall response rates and on the microstructure of responding were characterized. In three of the four pigeons, methamphetamine dose-dependently decreased overall response rate in both components; in the fourth pigeon, intermediate doses increased response rates. Log-survivor analyses did not produce the clear "broken-stick" pattern previously reported with rats [Shull, R.L., Gaynor, S.T., Grimes, J.A., 2001. Response rate viewed as engagement bouts: effects of relative reinforcement and schedule type. J. Exp. Anal. Behav. 75, 247-274]. A fine-grained analysis of inter-response times (IRTs) revealed clear bands of responding around certain IRT durations. Methamphetamine tended to decrease the frequency of IRTs in the shorter bands and increase the frequency of IRTs across all bins greater than 2s. These results suggest that (a) survivor analyses may not extend to pigeon key pecking, (b) microstructural analyses can reveal order not evident with overall response rate, and (c) a detailed analysis of responding might prove more useful than summary measures in characterizing drug effects on behavior.

  15. Response rate viewed as engagement bouts: resistance to extinction.

    PubMed Central

    Shull, Richard L; Gaynor, Scott T; Grimes, Julie A

    2002-01-01

    Rats obtained food pellets by nose poking a lighted key, the illumination of which alternated every 50 s during a session between blinking and steady, signaling either a relatively rich (60 per hour) or relatively lean (15 per hour) rate of reinforcement. During one training condition, all the reinforcers in the presence of the rich-reinforcement signal were response dependent (i.e., a variable-interval schedule); during another condition only 25% were response dependent (i.e., a variable-time schedule operated concurrently with a variable-interval schedule). An extinction session followed each training block. For both kinds of training schedule, and consistent with prior results, response rate was more resistant to extinction in the presence of the rich-reinforcement signal than in the presence of the lean-reinforcement signal. Analysis of interresponse-time distributions from baseline showed that differential resistance to extinction was not related to baseline differences in the rate of initiating response bouts or in the length of bouts. Also, bout-initiation rate (like response rate) was most resistant to extinction in the presence of the rich-reinforcement signal. These results support the proposal of behavioral momentum theory (e.g., Nevin & Grace, 2000) that resistance to extinction in the presence of a discriminative stimulus is determined more by the stimulus-reinforcer (Pavlovian) than by the stimulus-response-reinforcer (operant) contingency. PMID:12083677

  16. The acceptance rate of young wasps by alien colonies depends on colony developmental stages in the swarm-founding wasp, Polybia paulista von ihering (Hymenoptera: Vespidae).

    PubMed

    Kudô, Kazuyuki; Hozumi, Satoshi; Mateus, Sidnei; Zucchi, Ronaldo

    2010-01-01

    In social insects, newly emerged individuals learn the colony-specific chemical label from their natal comb shortly after their emergence. These labels help to identify each individual's colony of origin and are used as a recognition template against which individuals can discriminate nestmates from non-nestmates. Our previous studies with Polybia paulista von Ihering support this general pattern, and the acceptance rate of young female and male wasps decreased as a function of their age. Our study also showed in P. paulista that more than 90% of newly emerged female wasps might be accepted by conspecific unrelated colonies. However, it has not been investigated whether the acceptance rate of newly emerged female wasps depends on colony developmental stage of recipient colonies. We introduced newly emerged female wasps of P. paulista into different colony developmental stags of recipient colonies, i.e., worker-producing and male-producing colonies. We found that the acceptance rate of newly emerged female wasps by alien colonies was pretty lower by male-producing colonies than worker-producing colonies. This is the first study to show that the acceptance rate of young female wasps depends on stages of recipient colonies.

  17. Public Acceptance of Wildland Fire and Fuel Management: Panel Responses in Seven Locations

    NASA Astrophysics Data System (ADS)

    Toman, Eric; Shindler, Bruce; McCaffrey, Sarah; Bennett, James

    2014-09-01

    Wildland fire affects both public and private resources throughout the United States. A century of fire suppression has contributed to changing ecological conditions and accumulated fuel loads. Managers have used a variety of approaches to address these conditions and reduce the likelihood of wildland fires that may result in adverse ecological impacts and threaten communities. Public acceptance is a critical component of developing and implementing successful management programs. This study examines the factors that influence citizen support for agency fuel reduction treatments over time—particularly prescribed fire and mechanical vegetation removal. This paper presents findings from a longitudinal study examining resident beliefs and attitudes regarding fire management and fuels treatments in seven states: Arizona, Colorado, Oregon, Utah, Michigan, Minnesota, and Wisconsin. The study was implemented in two phases over a 6-year period using mail surveys to residents of communities adjacent to federal lands in each location. Questions replicated measures from the original project as well as some new items to allow a more in-depth analysis of key concepts. The study design enables comparisons over time as well as between locations. We also assess the factors that influence acceptance of both prescribed fire and mechanical vegetation removal. Findings demonstrate a relative stability of attitudes toward fuels management approaches over time and suggest that this acceptance is strongly influenced by confidence in resource managers and beliefs that the treatments would result in positive outcomes.

  18. Growth and development rates have different thermal responses.

    PubMed

    Forster, Jack; Hirst, Andrew G; Woodward, Guy

    2011-11-01

    Growth and development rates are fundamental to all living organisms. In a warming world, it is important to determine how these rates will respond to increasing temperatures. It is often assumed that the thermal responses of physiological rates are coupled to metabolic rate and thus have the same temperature dependence. However, the existence of the temperature-size rule suggests that intraspecific growth and development are decoupled. Decoupling of these rates would have important consequences for individual species and ecosystems, yet this has not been tested systematically across a range of species. We conducted an analysis on growth and development rate data compiled from the literature for a well-studied group, marine pelagic copepods, and use an information-theoretic approach to test which equations best describe these rates. Growth and development rates were best characterized by models with significantly different parameters: development has stronger temperature dependence than does growth across all life stages. As such, it is incorrect to assume that these rates have the same temperature dependence. We used the best-fit models for these rates to predict changes in organism mass in response to temperature. These predictions follow a concave relationship, which complicates attempts to model the impacts of increasing global temperatures on species body size.

  19. Study of High Strain Rate Response of Composites

    NASA Technical Reports Server (NTRS)

    Gilat, Amos

    2003-01-01

    The objective of the research was to continue the experimental study of the effect of strain rate on mechanical response (deformation and failure) of epoxy resins and carbon fibers/epoxy matrix composites, and to initiate a study of the effects of temperature by developing an elevated temperature test. The experimental data provide the information needed for NASA scientists for the development of a nonlinear, rate dependent deformation and strength models for composites that can subsequently be used in design. This year effort was directed into testing the epoxy resin. Three types of epoxy resins were tested in tension and shear at various strain rates that ranges from 5 x 10(exp -5), to 1000 per second. Pilot shear experiments were done at high strain rate and an elevated temperature of 80 C. The results show that all, the strain rate, the mode of loading, and temperature significantly affect the response of epoxy.

  20. Response of the μ-opioid system to social rejection and acceptance.

    PubMed

    Hsu, D T; Sanford, B J; Meyers, K K; Love, T M; Hazlett, K E; Wang, H; Ni, L; Walker, S J; Mickey, B J; Korycinski, S T; Koeppe, R A; Crocker, J K; Langenecker, S A; Zubieta, J-K

    2013-11-01

    The endogenous opioid system, which alleviates physical pain, is also known to regulate social distress and reward in animal models. To test this hypothesis in humans (n=18), we used an μ-opioid receptor (MOR) radiotracer to measure changes in MOR availability in vivo with positron emission tomography during social rejection (not being liked by others) and acceptance (being liked by others). Social rejection significantly activated the MOR system (i.e., reduced receptor availability relative to baseline) in the ventral striatum, amygdala, midline thalamus and periaqueductal gray (PAG). This pattern of activation is consistent with the hypothesis that the endogenous opioids have a role in reducing the experience of social pain. Greater trait resiliency was positively correlated with MOR activation during rejection in the amygdala, PAG and subgenual anterior cingulate cortex (sgACC), suggesting that MOR activation in these areas is protective or adaptive. In addition, MOR activation in the pregenual ACC was correlated with reduced negative affect during rejection. In contrast, social acceptance resulted in MOR activation in the amygdala and anterior insula, and MOR deactivation in the midline thalamus and sgACC. In the left ventral striatum, MOR activation during acceptance predicted a greater desire for social interaction, suggesting a role for the MOR system in social reward. The ventral striatum, amygdala, midline thalamus, PAG, anterior insula and ACC are rich in MORs and comprise a pathway by which social cues may influence mood and motivation. MOR regulation of this pathway may preserve and promote emotional well being in the social environment. PMID:23958960

  1. Response elimination, reinforcement rate and resurgence of operant behavior.

    PubMed

    Cançado, Carlos R X; Lattal, Kennon A

    2013-11-01

    The effects of reinforcement rate of alternative responding on resurgence were studied in six experiments with pigeons. In Experiment 1A, key pecking was maintained on a multiple variable-interval (VI) VI schedule in the Training phase. In the Response-Elimination phase, a variable differential-reinforcement-of-other-behavior (DRO) schedule was in effect in each component. Reinforcement rates were equal and then, higher in one (rich) component, and lower in the other (lean), than in the Training phase. More resurgence occurred in the lean component, but this could have resulted from response-rate differences between components in the Training-phase. Experiment 1B was a replication of Experiment 1A, but with experimentally-naïve pigeons. Response-Elimination phase reinforcement rates were manipulated systematically in subsequent experiments: In Experiment 2, reinforcement rate was equal, in one component, and lower or higher in the other, than in the Training phase. In Experiment 3, reinforcers were discontinued before differential reinforcement rates were effected. In Experiment 4, reinforcement rates first were differential and, then, equal to those in the Training phase. In Experiments 5 and 6, differential reinforcement rates were arranged by using fixed-DROs and VIs for pecking a different key, respectively. Even though resurgence was not obtained with every pigeon, at least some small-magnitude resurgence occurred in each experiment and was not related systematically to reinforcement rates of alternative responding. Schedule differences, response topography, order of conditions and the length of each phase were not sufficient to account for these results.

  2. Rates and technologies for mass-market demand response

    SciTech Connect

    Herter, Karen; Levy, Roger; Wilson, John; Rosenfeld, Arthur

    2002-07-21

    Demand response programs are often quickly and poorly crafted in reaction to an energy crisis and disappear once the crisis subsides, ensuring that the electricity system will be unprepared when the next crisis hits. In this paper, we propose to eliminate the event-driven nature of demand response programs by considering demand responsiveness a component of the utility obligation to serve. As such, demand response can be required as a condition of service, and the offering of demand response rates becomes a requirement of utilities as an element of customer service. Using this foundation, we explore the costs and benefits of a smart thermostat-based demand response system capable of two types of programs: (1) a mandatory, system-operator controlled, contingency program, and (2) a voluntary, customer controlled, bill management program with rate-based incentives. Any demand response program based on this system could consist of either or both of these components. Ideally, these programs would be bundled, providing automatic load management through customer-programmed price response, plus up to 10 GW of emergency load shedding capability in California. Finally, we discuss options for and barriers to implementation of such a program in California.

  3. Assessing recognition memory using confidence ratings and response times

    PubMed Central

    Kahana, Michael J.

    2016-01-01

    Classification of stimuli into categories (such as ‘old’ and ‘new’ in tests of recognition memory or ‘present’ versus ‘absent’ in signal detection tasks) requires the mapping of internal signals to discrete responses. Introspective judgements about a given choice response are regularly employed in research, legal and clinical settings in an effort to measure the signal that is thought to be the basis of the classification decision. Correlations between introspective judgements and task performance suggest that such ratings often do convey information about internal states that are relevant for a given task, but well-known limitations of introspection call the fidelity of this information into question. We investigated to what extent response times can reveal information usually assessed with explicit confidence ratings. We quantitatively compared response times to confidence ratings in their ability to qualify recognition memory decisions and found convergent results suggesting that much of the information from confidence ratings can be obtained from response times. PMID:27152209

  4. Are acceptance rates of a national preventive home visit programme for older people socially imbalanced?: a cross sectional study in Denmark

    PubMed Central

    2012-01-01

    Background Preventive home visits are offered to community dwelling older people in Denmark aimed at maintaining their functional ability for as long as possible, but only two thirds of older people accept the offer from the municipalities. The purpose of this study is to investigate 1) whether socioeconomic status was associated with acceptance of preventive home visits among older people and 2) whether municipality invitational procedures for the preventive home visits modified the association. Methods The study population included 1,023 community dwelling 80-year-old individuals from the Danish intervention study on preventive home visits. Information on preventive home visit acceptance rates was obtained from questionnaires. Socioeconomic status was measured by financial assets obtained from national registry data, and invitational procedures were identified through the municipalities. Logistic regression analyses were used, adjusted by gender. Results Older persons with high financial assets accepted preventive home visits more frequently than persons with low assets (adjusted OR = 1.5 (CI95%: 1.1-2.0)). However, the association was attenuated when adjusted by the invitational procedures. The odds ratio for accepting preventive home visits was larger among persons with low financial assets invited by a letter with a proposed date than among persons with high financial assets invited by other procedures, though these estimates had wide confidence intervals. Conclusion High socioeconomic status was associated with a higher acceptance rate of preventive home visits, but the association was attenuated by invitational procedures. The results indicate that the social inequality in acceptance of publicly offered preventive services might decrease if municipalities adopt more proactive invitational procedures. PMID:22656647

  5. The cost-effectiveness and consumer acceptability of taxation strategies to reduce rates of overweight and obesity among children in Australia: study protocol

    PubMed Central

    2013-01-01

    Background Childhood obesity is a recognised public health problem and around 25% of Australian children are overweight or obese. A major contributor is the obesogenic environment which encourages over consumption of energy dense nutrient poor food. Taxation is commonly proposed as a mechanism to reduce consumption of poor food choices and hence reduce rates of obesity and overweight in the community. Methods/Design An economic model will be developed to assess the lifetime benefits and costs to a cohort of Australian children by reducing energy dense nutrient poor food consumption through taxation mechanisms. The model inputs will be derived from a series of smaller studies. Food options for taxation will be derived from literature and expert opinion, the acceptability and impact of price changes will be explored through a Citizen’s Jury and a discrete choice experiment and price elasticities will be derived from the discrete choice experiment and consumption data. Discussion The health care costs of managing rising levels of obesity are a challenge for all governments. This study will provide a unique contribution to the international knowledge base by engaging a variety of robust research techniques, with a multidisciplinary focus and be responsive to consumers from diverse socio-economic backgrounds. PMID:24330325

  6. Spall Response of Tantalum at Extreme Strain-Rates

    NASA Astrophysics Data System (ADS)

    Hahn, Eric; Germann, Tim; Meyers, Marc

    Strain-rate and microstructure play a significant role in the ultimate mechanical response of materials. Using non-equilibrium molecular dynamics simulations, we characterize the ductile tensile failure of single and nanocrystalline tantalum over multiple orders of magnitude of strain-rate. This comparison is extended to over nine orders of magnitude including experimental results from resent laser shock campaigns. Spall strength primarily follows a power law dependence with strain-rate over this extensive range. In all cases, voids nucleate heterogeneously at pre-existing defects. Predictions based on traditional theory suggest that, as strain-rate increases, tensile strength should increase. Alternatively, as grain size decreases, tensile strength may decrease due to an increased propensity to fail at a growing volume fraction of grain boundaries. Strain-rate and grain size dictate void nucleation sites by changing the type and density of available defects: vacancies, dislocations, twins, and grain boundaries.

  7. Increasing Response Rates to Web-Based Surveys

    ERIC Educational Resources Information Center

    Monroe, Martha C.; Adams, Damian C.

    2012-01-01

    We review a popular method for collecing data--Web-based surveys. Although Web surveys are popular, one major concern is their typically low response rates. Using the Dillman et al. (2009) approach, we designed, pre-tested, and implemented a survey on climate change with Extension professionals in the Southeast. The Dillman approach worked well,…

  8. Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

    ERIC Educational Resources Information Center

    James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.

    2012-01-01

    The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease…

  9. Resistance to Change of Forgetting Functions and Response Rates

    ERIC Educational Resources Information Center

    Odum, Amy L.; Shahan, Timothy A.; Nevin, John A.

    2005-01-01

    This experiment examined the effects of reinforcement probability on resistance to change of remembering and response rate. Pigeons responded on a two- component multiple schedule in which completion of a variable-interval 20-s schedule produced delayed matching-to-sample trials in both components. Each session included four delays (0.1 s, 2 s, 4…

  10. Rates and technologies for mass-market demand response

    SciTech Connect

    Herter, Karen; Levy, Roger; Wilson, John; Rosenfeld, Arthur

    2002-07-21

    Demand response programs are often quickly and poorlycrafted in reaction to an energy crisis and disappear once the crisissubsides, ensuring that the electricity system will be unprepared whenthe next crisis hits. In this paper, we propose to eliminate theevent-driven nature of demand response programs by considering demandresponsiveness a component of the utility obligation to serve. As such,demand response can be required as a condition of service, and theoffering of demand response rates becomes a requirement of utilities asan element of customer service. Using this foundation, we explore thecosts and benefits of a smart thermostat-based demand response systemcapable of two types of programs: (1) a mandatory, system-operatorcontrolled, contingency program, and (2) a voluntary, customercontrolled, bill management program with rate-based incentives. Anydemand response program based on this system could consist of either orboth of these components. Ideally, these programs would be bundled,providing automatic load management through customer-programmed priceresponse, plus up to 10 GW of emergency load shedding capability inCalifornia. Finally, we discuss options for and barriers toimplementation of such a program in California.

  11. Effects of Content Polarization, Item Wording, and Rating Scale Width on Rating Responses.

    ERIC Educational Resources Information Center

    Lam, Tony C. M.; Stevens, Joseph J.

    1994-01-01

    Effects of the following three variables on rating scale response were studied: (1) polarization of opinion regarding scale content; (2) intensity of item wording; and (3) psychological width of the scale. Results with 167 college students suggest best ways to balance polarization and item wording regardless of scale width. (SLD)

  12. What Responsibilities Should Teachers Accept? Stirling Educational Seminar Papers No. 1.

    ERIC Educational Resources Information Center

    McIntyre, Donald

    1979-01-01

    Five value-laden levels of increasing responsibility are outlined as criteria applied to teacher's own activities; students' overt classroom behavior; comprehension and attitudes; abilities acquired by students; and future characteristics of students. Knowledge available to a teacher and working conditions influence level choice more than teacher…

  13. Homeostatic responses to caloric restriction: influence of background metabolic rate.

    PubMed

    Evans, S A; Parsons, A D; Overton, J M

    2005-10-01

    The biological responses to caloric restriction (CR) are generally examined in rats with elevated metabolic rates due to being housed at ambient temperatures (T(a)) below the zone of thermoneutrality. We determined the physiological and behavioral responses to 2 wk of 30-40% CR in male FBNF1 rats housed in cool (T(a) = 12 degrees C) or thermoneutral (TMN; T(a) = 30 degrees C) conditions. Rats were instrumented with telemetry devices and housed continuously in home-cage calorimeters for the entire experiment. At baseline, rats housed in cool T(a) had reduced rate of weight gain; thus a mild CR (5%) group at thermoneutrality for weight maintenance was also studied. Rats housed in cool T(a) exhibited elevated caloric intake (cool = 77 +/- 1; TMN = 54 +/- 2 kcal), oxygen consumption (Vo(2); cool = 9.9 +/- 0.1; TMN = 5.5 +/- 0.1 ml/min), mean arterial pressure (cool = 103 +/- 1; TMN = 80 +/- 2 mmHg), and heart rate (cool = 374 +/- 3; TMN = 275 +/- 4 beats/min). Cool-CR rats exhibited greater CR-induced weight loss (cool = -62 +/- 3; TMN = -42 +/- 3 g) and reductions in Vo(2) (cool = -2.6 +/- 0.1; TMN = -1.5 +/- 0.1 ml/min) but similar CR-induced reductions in heart rate (cool = -59 +/- 1; TMN= -51 +/- 7 beats/min). CR had no effect on arterial blood pressure or locomotor activity in either group. Unexpectedly, weight maintenance produced significant reductions in Vo(2) and heart rate. At thermoneutrality, a single day of refeeding effectively abolished CR-induced reductions in Vo(2) and heart rate. The results reveal that rats with low or high baseline metabolic rate exhibit comparable compensatory reductions in Vo(2) and heart rate and suggest that T(a) can be used to modulate the metabolic background on which the more prolonged effects of CR can be studied.

  14. The relationship between hearing aid frequency response and acceptable noise level in patients with sensorineural hearing loss

    PubMed Central

    Jalilvand, Hamid; Pourbakht, Akram; Jalaee, Shohreh

    2015-01-01

    Background: When fitting hearing aid as a compensatory device for an impaired cochlea in a patient with sensorineural hearing loss (HL), it is needed to the effective and efficient frequency response would be selected regarding providing the patient's perfect speech perception. There is not any research about the effects of frequency modifications on speech perception in patients with HL regarding the cochlear desensitization. The effect (s) of modifications in frequency response of hearing aid amplification on the results of acceptable noise level (ANL) test is the main aim of this study. Materials and Methods: The amounts of ANL in two conditions of linear amplification (high frequency emphasis [HFE] and mid frequency emphasis [MFE]) were measured. Thirty-two male subjects who participated in this study had the moderate to severe sensorineural HL. Results: There was not any significant difference between ANL in linear amplification of hearing aid with HFE frequency response and ANL in linear amplification of hearing aid with MFE frequency response. Conclusion: The gain modification of frequency response not only does not affect the patient's performance of speech intelligibility in ANL test. This indicates that we need to note to the cochlear desensitization phenomenon when fitting hearing aid as a compensatory device for an impaired cochlea in a patient. The cochlear desensitization has not been considered properly in hearing aid fitting formula which is needed to be explored more about the bio-mechanisms of impaired cochlea. PMID:26918238

  15. Sensory evaluation ratings and melting characteristics show that okra gum is an acceptable milk-fat ingredient substitute in chocolate frozen dairy dessert.

    PubMed

    Romanchik-Cerpovicz, Joelle E; Costantino, Amanda C; Gunn, Laura H

    2006-04-01

    Reducing dietary fat intake may lower the risk of developing coronary heart disease. This study examined the feasibility of substituting okra gum for 25%, 50%, 75%, or 100% milk fat in frozen chocolate dairy dessert. Fifty-six consumers evaluated the frozen dairy desserts using a hedonic scale. Consumers rated color, smell, texture, flavor, aftertaste, and overall acceptability characteristics of all products as acceptable. All ratings were similar among the products except for the aftertaste rating, which was significantly lower for chocolate frozen dairy dessert containing 100% milk-fat replacement with okra gum compared with the control (0% milk-fat replacement) (P<0.05). Whereas melting points of all products were similar, melting rates slowed significantly as milk-fat replacement with okra gum increased, suggesting that okra gum may increase the stability of frozen dairy desserts (P<0.05). Overall, this study shows that okra gum is an acceptable milk-fat ingredient substitute in chocolate frozen dairy dessert.

  16. Water-balance uncertainty in Honduras: a limits-of-acceptability approach to model evaluation using a time-variant rating curve

    NASA Astrophysics Data System (ADS)

    Westerberg, I.; Guerrero, J.-L.; Beven, K.; Seibert, J.; Halldin, S.; Lundin, L.-C.; Xu, C.-Y.

    2009-04-01

    The climate of Central America is highly variable both spatially and temporally; extreme events like floods and droughts are recurrent phenomena posing great challenges to regional water-resources management. Scarce and low-quality hydro-meteorological data complicate hydrological modelling and few previous studies have addressed the water-balance in Honduras. In the alluvial Choluteca River, the river bed changes over time as fill and scour occur in the channel, leading to a fast-changing relation between stage and discharge and difficulties in deriving consistent rating curves. In this application of a four-parameter water-balance model, a limits-of-acceptability approach to model evaluation was used within the General Likelihood Uncertainty Estimation (GLUE) framework. The limits of acceptability were determined for discharge alone for each time step, and ideally a simulated result should always be contained within the limits. A moving-window weighted fuzzy regression of the ratings, based on estimated uncertainties in the rating-curve data, was used to derive the limits. This provided an objective way to determine the limits of acceptability and handle the non-stationarity of the rating curves. The model was then applied within GLUE and evaluated using the derived limits. Preliminary results show that the best simulations are within the limits 75-80% of the time, indicating that precipitation data and other uncertainties like model structure also have a significant effect on predictability.

  17. Comparison of four different mobile devices for measuring heart rate and ECG with respect to aspects of usability and acceptance by older people.

    PubMed

    Ehmen, Hilko; Haesner, Marten; Steinke, Ines; Dorn, Mario; Gövercin, Mehmet; Steinhagen-Thiessen, Elisabeth

    2012-05-01

    In the area of product design and usability, most products are developed for the mass-market by technically oriented designers and developers for use by persons who themselves are also technically adept by today's standards. The demands of older people are commonly not given sufficient consideration within the early developmental process. In the present study, the usability and acceptability of four different devices meant to be worn for the measurement of heart rate or ECG were analyzed on the basis of qualitative subjective user ratings and structured interviews of twelve older participants. The data suggest that there was a relatively high acceptance concerning these belts by older adults but none of the four harnesses was completely usable. Especially problematic to the point of limiting satisfaction among older subjects were problems encountered while adjusting the length of the belt and/or closing the locking mechanism. The two devices intended for dedicated heart rate recording yielded the highest user ratings for design, and were clearly preferred for extended wearing time. Yet for all the devices participants identified several important deficiencies in their design, as well as suggestions for improvement. We conclude that the creation of an acceptable monitoring device for older persons requires designers and developers to consider the special demands and abilities of the target group.

  18. Community Colleges Maintain Modest Response Rates to Prospective Student Inquiry

    ERIC Educational Resources Information Center

    Shadinger, David; Sherry, Kristin M.; Smith, Hollie L.; Clark, Emilie C.

    2016-01-01

    None of the community colleges in this study responded with a text message, as requested in the prospective student's inquiry. Only 1.38% (n = 3) of the institutions responded to the inquiry with a telephone call. This research realized a slightly higher rate of e-mail response within five working days; 54.98% (n = 116) as opposed to the 2009…

  19. Nonlinear modelling and control for heart rate response to exercise.

    PubMed

    Zhang, Y; Chen, W; Su, S W; Celler, B

    2012-01-01

    In order to accurately regulate cardiovascular response to exercise for individual exerciser, this study proposes a modelling and control integrated approach based on ε-insensitive Support Vector Regression (SVR) and switching control strategy. Firstly, a control oriented modelling approach is proposed to depict nonlinear behaviours of cardiovascular response at both onset and offset of treadmill exercises by using support vector machine regression. Then, based on the established nonlinear time-variant model, a novel switching Model Predictive Control (MPC) algorithm has been proposed for the optimisation of exercise efforts. The designed controller can take into account both coefficient drifting and parameter jump by embedding the identified model coefficient into the optimiser and adopting switching strategy during the transfer between onset and offset of exercises. The effectiveness of the proposed modelling and control approach was shown from the regulation of dynamical heart rate response to exercise through simulation using MATLAB.

  20. The Sensitivity of Response Rate to the Rate of Variable-Interval Reinforcement for Pigeons and Rats: A Review

    ERIC Educational Resources Information Center

    Shull, Richard L.

    2005-01-01

    The relation between the rate of a response ("B") and the rate of its reinforcement ("R") is well known to be approximately hyperbolic: B = kR/(R + R[subscript o]), where k represents the maximum response rate, and R[subscript o] indicates the rate of reinforcers that will engender a response rate equal to half its maximum value. A review of data…

  1. Acceptance and utilisation of the Incident Command System in first response and allied disciplines: an Ohio study.

    PubMed

    Decker, Russell J

    2011-10-01

    In response to the terrorist attacks of September 11th, 2001, an effort was made to establish a common and uniform command structure for use by the nation's first responder organisations, as well as those disciplines generally expected to assist first responders during a major incident or disaster. The result was the issuance of the National Incident Management System1 or NIMS by the US Department of Homeland Security in 2004. Included in the NIMS document was an embracing of the Incident Command System or ICS, long utilised in the fire service for the effective management of emergency response. The NIMS doctrine also identified certain allied disciplines that needed to adopt this new system for responding to major events. Some of these disciplines included specialised first response units, such as, bomb squads and hazardous materials teams. Other partner disciplines not usually associated with emergency response to include public health and public works were also included. This study will attempt to look at a single component of NIMS, specifically the Incident Command System, and measure its acceptance and utilisation by first responder organisations and selected allied disciplines in the state of Ohio. This is particularly important at this time since the US government is being forced to reduce budgets significantly and determine which laudable policies and programmes will be cut.

  2. Cholesterol enhances classical conditioning of the rabbit heart rate response

    PubMed Central

    Schreurs, Bernard G.; Smith-Bell, Carrie A.; Darwish, Deya S.; Wang, Desheng; Burhans, Lauren B.; Gonzales-Joekes, Jimena; Deci, Stephen; Stankovic, Goran; Sparks, D. Larry

    2007-01-01

    The cholesterol-fed rabbit is a model of atherosclerosis and has been proposed as an animal model of Alzheimer's disease. Feeding rabbits cholesterol has been shown to increase the number of beta amyloid immunoreactive neurons in the cortex. Addition of copper to the drinking water of cholesterol-fed rabbits can increase this number still further and may lead to plaque-like structures. Classical conditioning of the nictitating membrane response in cholesterol-fed rabbits is retarded in the presence of these plaque-like structures but may be facilitated in their absence. In a factorial design, rabbits fed 2% cholesterol or a normal diet (0% cholesterol) for 8 weeks with or without copper added to the drinking water were given trace classical conditioning using a tone and periorbital electrodermal stimulation to study the effects of cholesterol and copper on classical conditioning of heart rate and the nictitating membrane response. Cholesterol-fed rabbits showed significant facilitation of heart rate conditioning and conditioning-specific modification of heart rate relative to normal diet controls. Consistent with previous research, cholesterol had minimal effects on classical conditioning of the nictitating membrane response when periorbital electrodermal stimulation was used as the unconditioned stimulus. Immunohistochemical analysis showed a significant increase in the number of beta amyloid positive neurons in the cortex, hippocampus and amygdala of the cholesterol-fed rabbits. Supplementation of drinking water with copper increased the number of beta amyloid positive neurons in the cortex of cholesterol-fed rabbits but did not produce plaque-like structures or have a significant effect on heart rate conditioning. The data provide additional support for our finding that, in the absence of plaques, dietary cholesterol may facilitate learning and memory. PMID:17466388

  3. PowerChoice Residential Customer Response to TOU Rates

    SciTech Connect

    Peters, Jane S.; Moezzi, Mithra; Lutzenhiser, Susan; Woods, James; Dethman, Linda; Kunkle, Rick

    2009-10-01

    Research Into Action, Inc. and the Sacramento Municipal Utility District (SMUD) worked together to conduct research on the behaviors and energy use patterns of SMUD residential customers who voluntarily signed on to a Time-of-Use rate pilot launched under the PowerChoice label. The project was designed to consider the how and why of residential customers ability and willingness to engage in demand reduction behaviors, and to link social and behavioral factors to observed changes in demand. The research drew on a combination of load interval data and three successive surveys of participating households. Two experimental treatments were applied to test the effects of increased information on households ability to respond to the Time-of-Use rates. Survey results indicated that participants understood the purpose of the Time-of-Use rate and undertook substantial appropriate actions to shift load and conserve. Statistical tests revealed minor initial price effects and more marked, but still modest, adjustments to seasonal rate changes. Tests of the two information interventions indicated that neither made much difference to consumption patterns. Despite the lackluster statistical evidence for load shifting, the analysis points to key issues for critical analysis and development of residential Time-of-Use rates, especially pertinent as California sets the stage for demand response in more California residences.

  4. Response of Escherichia coli growth rate to osmotic shock.

    PubMed

    Rojas, Enrique; Theriot, Julie A; Huang, Kerwyn Casey

    2014-05-27

    It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless "stored" growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan. PMID:24821776

  5. Functional response models to estimate feeding rates of wading birds

    USGS Publications Warehouse

    Collazo, J.A.; Gilliam, J.F.; Miranda-Castro, L.

    2010-01-01

    Forager (predator) abundance may mediate feeding rates in wading birds. Yet, when modeled, feeding rates are typically derived from the purely prey-dependent Holling Type II (HoII) functional response model. Estimates of feeding rates are necessary to evaluate wading bird foraging strategies and their role in food webs; thus, models that incorporate predator dependence warrant consideration. Here, data collected in a mangrove swamp in Puerto Rico in 1994 were reanalyzed, reporting feeding rates for mixed-species flocks after comparing fits of the HoII model, as used in the original work, to the Beddington-DeAngelis (BD) and Crowley-Martin (CM) predator-dependent models. Model CM received most support (AIC c wi = 0.44), but models BD and HoII were plausible alternatives (AIC c ??? 2). Results suggested that feeding rates were constrained by predator abundance. Reductions in rates were attributed to interference, which was consistent with the independently observed increase in aggression as flock size increased (P < 0.05). Substantial discrepancies between the CM and HoII models were possible depending on flock sizes used to model feeding rates. However, inferences derived from the HoII model, as used in the original work, were sound. While Holling's Type II and other purely prey-dependent models have fostered advances in wading bird foraging ecology, evaluating models that incorporate predator dependence could lead to a more adequate description of data and processes of interest. The mechanistic bases used to derive models used here lead to biologically interpretable results and advance understanding of wading bird foraging ecology.

  6. Response of Escherichia coli growth rate to osmotic shock.

    PubMed

    Rojas, Enrique; Theriot, Julie A; Huang, Kerwyn Casey

    2014-05-27

    It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless "stored" growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan.

  7. Quantifying rates of evolutionary adaptation in response to ocean acidification.

    PubMed

    Sunday, Jennifer M; Crim, Ryan N; Harley, Christopher D G; Hart, Michael W

    2011-01-01

    The global acidification of the earth's oceans is predicted to impact biodiversity via physiological effects impacting growth, survival, reproduction, and immunology, leading to changes in species abundances and global distributions. However, the degree to which these changes will play out critically depends on the evolutionary rate at which populations will respond to natural selection imposed by ocean acidification, which remains largely unquantified. Here we measure the potential for an evolutionary response to ocean acidification in larval development rate in two coastal invertebrates using a full-factorial breeding design. We show that the sea urchin species Strongylocentrotus franciscanus has vastly greater levels of phenotypic and genetic variation for larval size in future CO(2) conditions compared to the mussel species Mytilus trossulus. Using these measures we demonstrate that S. franciscanus may have faster evolutionary responses within 50 years of the onset of predicted year-2100 CO(2) conditions despite having lower population turnover rates. Our comparisons suggest that information on genetic variation, phenotypic variation, and key demographic parameters, may lend valuable insight into relative evolutionary potentials across a large number of species.

  8. Heart rate responses to autonomic challenges in obstructive sleep apnea.

    PubMed

    Macey, Paul M; Kumar, Rajesh; Woo, Mary A; Yan-Go, Frisca L; Harper, Ronald M

    2013-01-01

    Obstructive sleep apnea (OSA) is accompanied by structural alterations and dysfunction in central autonomic regulatory regions, which may impair dynamic and static cardiovascular regulation, and contribute to other syndrome pathologies. Characterizing cardiovascular responses to autonomic challenges may provide insights into central nervous system impairments, including contributions by sex, since structural alterations are enhanced in OSA females over males. The objective was to assess heart rate responses in OSA versus healthy control subjects to autonomic challenges, and, separately, characterize female and male patterns. We studied 94 subjects, including 37 newly-diagnosed, untreated OSA patients (6 female, age mean ± std: 52.1 ± 8.1 years; 31 male aged 54.3 ± 8.4 years), and 57 healthy control subjects (20 female, 50.5 ± 8.1 years; 37 male, 45.6 ± 9.2 years). We measured instantaneous heart rate with pulse oximetry during cold pressor, hand grip, and Valsalva maneuver challenges. All challenges elicited significant heart rate differences between OSA and control groups during and after challenges (repeated measures ANOVA, p<0.05). In post-hoc analyses, OSA females showed greater impairments than OSA males, which included: for cold pressor, lower initial increase (OSA vs. control: 9.5 vs. 7.3 bpm in females, 7.6 vs. 3.7 bpm in males), OSA delay to initial peak (2.5 s females/0.9 s males), slower mid-challenge rate-of-increase (OSA vs. control: -0.11 vs. 0.09 bpm/s in females, 0.03 vs. 0.06 bpm/s in males); for hand grip, lower initial peak (OSA vs. control: 2.6 vs. 4.6 bpm in females, 5.3 vs. 6.0 bpm in males); for Valsalva maneuver, lower Valsalva ratio (OSA vs. control: 1.14 vs. 1.30 in females, 1.29 vs. 1.34 in males), and OSA delay during phase II (0.68 s females/1.31 s males). Heart rate responses showed lower amplitude, delayed onset, and slower rate changes in OSA patients over healthy controls, and impairments may be more pronounced in females. The

  9. On the response of rubbers at high strain rates.

    SciTech Connect

    Niemczura, Johnathan Greenberg

    2010-02-01

    In this report, we examine the propagation of tensile waves of finite deformation in rubbers through experiments and analysis. Attention is focused on the propagation of one-dimensional dispersive and shock waves in strips of latex and nitrile rubber. Tensile wave propagation experiments were conducted at high strain-rates by holding one end fixed and displacing the other end at a constant velocity. A high-speed video camera was used to monitor the motion and to determine the evolution of strain and particle velocity in the rubber strips. Analysis of the response through the theory of finite waves and quantitative matching between the experimental observations and analytical predictions was used to determine an appropriate instantaneous elastic response for the rubbers. This analysis also yields the tensile shock adiabat for rubber. Dispersive waves as well as shock waves are also observed in free-retraction experiments; these are used to quantify hysteretic effects in rubber.

  10. Burning rate response of liquid monopropellants to imposed pressure oscillations

    NASA Technical Reports Server (NTRS)

    Allison, C. B.

    1974-01-01

    The combustion characteristics of hydrazine strands were studied under both steady state and oscillatory conditions. A steady strand burner was used to measure steady strand burning rates, liquid temperature distributions and surface temperatures as a function of pressure in the pressure range of 0.32 to 42 atm. It was found that for subatmospheric pressures the burning rate varied as the square root of pressure; for pressures greater than atmospheric the burning rate varied linearly with pressure. A theoretical model of the strand combustion system was developed and matched to the steady burning rates by assuming a reaction order of one for subatmospheric pressures and a reaction order of two for pressures greater than atmospheric. The model was also found to be in good agreement with measurements of liquid temperature distributions and surface temperatures. The results show an increse in the response of the combustion process as interaction occurs with transient liquid phase effects, yielding a band of frequencies where the combustion process exerts sufficient amplifying power to provide a mechanism for driving combustion instability.

  11. The effects of container design and stair climbing on maximal acceptable lift weight, wrist posture, psychophysical, and physiological responses in wafer-handling tasks.

    PubMed

    Chung, H C; Wang, M J

    2001-12-01

    Despite the high level of automation in semiconductor manufacturing processes, many manual operations are still involved in the workplace. Due to inadequate human-machine interface design, stairs are frequently used to help operators perform wafer-handling tasks. This study was designed to evaluate the effects of climbing stairs and carrying wafer containers (pods) on psychophysical responses (maximal acceptable weight of lift--MAWL, and ratings of perceived exertion--RPE), physiological responses (oxygen consumption--VO2, and heart rate--HR), and wrist posture (ulnar and radial deviations). Each of 12 subjects (six males and six females) performed six sessions (3 climbing stairs x 2 pods types). The results indicate that climbing stairs had a significant influence on MAWL and VO2 (p<0.01). The type of pod effect on wrist posture was significant (p<0.01). Gender effect differences on MAWL, VO2 and wrist posture were also significant (p<0.05). Job design implications are discussed.

  12. The effect of heart rate on the heart rate variability response to autonomic interventions.

    PubMed

    Billman, George E

    2013-01-01

    Heart rate variability (HRV), the beat-to-beat variation in either heart rate (HR) or heart period (R-R interval), has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20) or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9) autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD) and the high frequency (HF) variability (HF, 0.24-1.04 Hz) were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec)(2) for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF) while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation) even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.

  13. A strong response to selection on mass-independent maximal metabolic rate without a correlated response in basal metabolic rate.

    PubMed

    Wone, B W M; Madsen, P; Donovan, E R; Labocha, M K; Sears, M W; Downs, C J; Sorensen, D A; Hayes, J P

    2015-04-01

    Metabolic rates are correlated with many aspects of ecology, but how selection on different aspects of metabolic rates affects their mutual evolution is poorly understood. Using laboratory mice, we artificially selected for high maximal mass-independent metabolic rate (MMR) without direct selection on mass-independent basal metabolic rate (BMR). Then we tested for responses to selection in MMR and correlated responses to selection in BMR. In other lines, we antagonistically selected for mice with a combination of high mass-independent MMR and low mass-independent BMR. All selection protocols and data analyses included body mass as a covariate, so effects of selection on the metabolic rates are mass adjusted (that is, independent of effects of body mass). The selection lasted eight generations. Compared with controls, MMR was significantly higher (11.2%) in lines selected for increased MMR, and BMR was slightly, but not significantly, higher (2.5%). Compared with controls, MMR was significantly higher (5.3%) in antagonistically selected lines, and BMR was slightly, but not significantly, lower (4.2%). Analysis of breeding values revealed no positive genetic trend for elevated BMR in high-MMR lines. A weak positive genetic correlation was detected between MMR and BMR. That weak positive genetic correlation supports the aerobic capacity model for the evolution of endothermy in the sense that it fails to falsify a key model assumption. Overall, the results suggest that at least in these mice there is significant capacity for independent evolution of metabolic traits. Whether that is true in the ancestral animals that evolved endothermy remains an important but unanswered question.

  14. Human breathing and eye blink rate responses to airborne chemicals.

    PubMed Central

    Walker, J C; Kendal-Reed, M; Utell, M J; Cain, W S

    2001-01-01

    Increased levels of air pollution have been linked with morbidity and mortality, but mechanisms linking physiologic responses to quality of life and productivity issues remain largely unknown. Individuals often report irritation of the nose and/or eyes upon exposures to environmental contaminants. Evaluation of these self-reports would be greatly aided by the development of valid physiological markers. Chamber studies (unencumbered exposures) of nonsmoker responses to environmental tobacco smoke offer two candidate end points: (a) Tidal volume increases and breathing frequency declines with stimuli that elicit only moderate irritation. (b) Eye blink rate increases only with a concentration sufficiently high to cause progressive worsening of eye irritation with prolonged exposure. Experiments with very brief nasal-only presentations also suggest the value of breathing changes as sensitive markers of irritation: (a) Tidal volume is inversely related to perceived nasal irritation (NI) intensity in both normal and anosmic (lacking olfactory input) individuals, although normals exhibit greater NI sensitivity. (b) Inhalation duration, in both groups, declines only with trigeminal activation sufficient to cause readily perceptible NI in anosmics. Changes in eye blink rate and breathing may be useful in the investigation of irritation and other effects of air pollution, and could be quite useful in investigations of mixtures of volatile organic compounds. PMID:11544155

  15. Relationship between Arousal Intensity and Heart Rate Response to Arousal

    PubMed Central

    Azarbarzin, Ali; Ostrowski, Michele; Hanly, Patrick; Younes, Magdy

    2014-01-01

    Study Objectives: The visual appearance of cortical arousals varies considerably, from barely meeting scoring criteria to very intense arousals. Arousal from sleep is associated with an increase in heart rate (HR). Our objective was to quantify the intensity of arousals in an objective manner using the time and frequency characteristics of the electroencephalogram (EEG) and to determine whether HR response to arousal correlates with arousal intensity so determined. Design: Post hoc analysis of 20 preexisting polysomnography (PSG) files. Setting: Research and Development Laboratory (YRT Limited). Participants: N/A. Interventions: None. Measurements and Results: Arousals were scored using the American Academy of Sleep Medicine criteria. The EEG signals' time and frequency characteristics were determined using wavelet analysis. An automatic algorithm was developed to scale arousal intensity based on the change in wavelet features and data from a training set obtained from 271 arousals visually scaled between zero and nine (most intense). There were 2,695 arousals in 20 PSGs that were scaled. HR response (ΔHR) was defined as the difference between the highest HR in the interval [arousal-onset to (arousal-end +8 sec)] and the highest HR between 2 and 12 sec preceding arousal onset. There was a strong correlation between arousal scale and ΔHR within each subject (average r: 0.95 ± 0.04). The slope of the relationship varied among subjects (0.7-2.4 min-1/unit scale). Conclusions: Arousal intensity, quantified by wavelet transform, is strongly associated with arousal-related tachycardia, and the gain of the relationship varies among subjects. Quantifying arousal intensity in PSGs provides additional information that may be clinically relevant. Citation: Azarbarzin A; Ostrowski M; Hanly P; Younes M. Relationship between arousal intensity and heart rate response to arousal. SLEEP 2014;37(4):645-653. PMID:24899756

  16. Heart rate and blood lactate responses during competitive Olympic boardsailing.

    PubMed

    Guével, A; Maïsetti, O; Prou, E; Dubois, J J; Marini, J F

    1999-02-01

    The rules of competitive boardsailing events were changed before the Atlanta Olympic Games. Pumping the sail (pulling repeatedly on the rig) is now allowed and the duration of races has been shortened. Eight members of the French national team (mean age 23+/-2.7 years) participated in this study. Their cardiac and metabolic responses were assessed by measuring heart rate and blood lactate concentration during various competitive events in two strengths of wind (light vs. moderate). Heart rate was higher in light (87.4+/-4.3% HRmax; mean racing time 37 min) than in moderate wind conditions (82.9+/-5.3% HRmax; mean racing time 33 min). The mean post-race blood lactate concentration (5.2+/-1.0 mmol x l(-1)) was not affected by the wind conditions. Mean heart rate was highest during downwind legs (88.0+/-3.1% HRmax; duration 7-10 min). The races consisted of two laps, the first of which induced significantly higher cardiac demands than the second. We conclude that the changes to the rules of competitive boardsailing have increased the cardiac and metabolic efforts involved. PMID:10069270

  17. Heart rate & blood lactate response in amateur competitive boxing.

    PubMed

    Ghosh, A K; Goswami, A; Ahuja, A

    1995-10-01

    The heart rate (HR) and blood lactate response were studied on 26 senior national level boxers in competitive bouts to explore the aerobic-anaerobic metabolism as well as the training status of the players. The aerobic capacity (VO2 max) of the players were determined using graded running protocol on a treadmill. Heart rate and blood lactate concentration were measured during warm up and boxing rounds. The mean relative VO2 max of the heavy weight category boxers was lower (P < 0.05) than the other two weight categories. No interweight category as well as inter-round differences were observed in the heart rate and blood lactate concentration of the boxers, excepting in the 48-57 kg category, the mean lactate levels in the second and third rounds were higher (P < 0.05) than in the first round. When all weight categories were pooled the mean HR and blood lactate levels were 178 beats/min and 8.24 mMol/l respectively. The study highlights that in amateur boxing, irrespective of the weight category and aerobic capacity, the anaerobic adaptability of the boxers was the same. The training requirements of the boxers demand that they should be also to tolerate a high blood lactate level (approx. 9.0 mMol/l) and a high HR (approx. 180 beats/min) over a total duration of one bout.

  18. Young Children's Affective Responses to Acceptance and Rejection from Peers: A Computer-Based Task Sensitive to Variation in Temperamental Shyness and Gender

    ERIC Educational Resources Information Center

    Howarth, Grace Z.; Guyer, Amanda E.; Perez-Edgar, Koraly

    2013-01-01

    This study presents a novel task examining young children's affective responses to evaluative feedback--specifically, social acceptance and rejection--from peers. We aimed to determine (1) whether young children report their affective responses to hypothetical peer evaluation predictably and consistently, and (2) whether young children's responses…

  19. Heart rate, startle response, and intrusive trauma memories

    PubMed Central

    Chou, Chia-Ying; Marca, Roberto La; Steptoe, Andrew; Brewin, Chris R

    2014-01-01

    The current study adopted the trauma film paradigm to examine potential moderators affecting heart rate (HR) as an indicator of peritraumatic psychological states and as a predictor of intrusive memories. We replicated previous findings that perifilm HR decreases predicted the development of intrusive images and further showed this effect to be specific to images rather than thoughts, and to detail rather than gist recognition memory. Moreover, a group of individuals showing both an atypical sudden reduction in HR after a startle stimulus and higher trait dissociation was identified. Only among these individuals was lower perifilm HR found to indicate higher state dissociation, fear, and anxiety, along with reduced vividness of intrusions. The current findings emphasize how peritraumatic physiological responses relate to emotional reactions and intrusive memory. The moderating role of individual difference in stress defense style was highlighted. PMID:24397333

  20. Parental modelling and prompting effects on acceptance of a novel fruit in 2-4-year-old children are dependent on children's food responsiveness.

    PubMed

    Blissett, Jackie; Bennett, Carmel; Fogel, Anna; Harris, Gillian; Higgs, Suzanne

    2016-02-14

    Few children consume the recommended portions of fruit or vegetables. This study examined the effects of parental physical prompting and parental modelling in children's acceptance of a novel fruit (NF) and examined the role of children's food-approach and food-avoidance traits on NF engagement and consumption. A total of 120 caregiver-child dyads (fifty-four girls, sixty-six boys) participated in this study. Dyads were allocated to one of the following three conditions: physical prompting but no modelling, physical prompting and modelling or a modelling only control condition. Dyads ate a standardised meal containing a portion of a fruit new to the child. Parents completed measures of children's food approach and avoidance. Willingness to try the NF was observed, and the amount of the NF consumed was measured. Physical prompting but no modelling resulted in greater physical refusal of the NF. There were main effects of enjoyment of food and food fussiness on acceptance. Food responsiveness interacted with condition such that children who were more food responsive had greater NF acceptance in the prompting and modelling conditions in comparison with the modelling only condition. In contrast, children with low food responsiveness had greater acceptance in the modelling control condition than in the prompting but no modelling condition. Physical prompting in the absence of modelling is likely to be detrimental to NF acceptance. Parental use of physical prompting strategies, in combination with modelling of NF intake, may facilitate acceptance of NF, but only in food-responsive children. Modelling consumption best promotes acceptance in children with low food responsiveness.

  1. Transfer of heart rate feedback training to reduce heart rate response to laboratory tasks.

    PubMed

    Goodie, Jeffrey L; Larkin, Kevin T

    2006-09-01

    To examine whether transfer of heart rate (HR) feedback training to tasks not used during training could be improved by using multiple tasks during training, a modified multiple baseline across tasks, single subject design study was conducted using six high HR-reactive young adults. Participants received HR feedback training during the presentation of a videogame, and transfer of training was assessed to a mental arithmetic challenge and handgrip task. Transfer of training was next assessed following training with the mental arithmetic challenge and handgrip task. HR responses to each training task with no HR feedback were assessed during a pre-treatment session, an immediate post-training period following training on each task, a short delay (1-2 days) post-training session, and a long delay (1-2 weeks) post-training session. HR response to a novel speech task was assessed at pre-treatment and during short delay and long delay post-training sessions. Results revealed that participants reduced HR during training and generally maintained this reduction in HR during the immediate post-training assessment when HR feedback was not present. Participants were not able to reduce HR responses to tasks during short delay and long delay post-training sessions, and they were unable to transfer HR reduction skills to the speech task. Transfer of HR feedback training to new tasks was limited in nature and efforts to train across multiple stressors did not appear to improve transfer of training.

  2. Feasibility and acceptability of oral cholera vaccine mass vaccination campaign in response to an outbreak and floods in Malawi

    PubMed Central

    Msyamboza, Kelias Phiri; M'bang'ombe, Maurice; Hausi, Hannah; Chijuwa, Alexander; Nkukumila, Veronica; Kubwalo, Hudson Wenji; Desai, Sachin; Pezzoli, Lorenzo; Legros, Dominique

    2016-01-01

    Introduction Despite some improvement in provision of safe drinking water, proper sanitation and hygiene promotion, cholera still remains a major public health problem in Malawi with outbreaks occurring almost every year since 1998. In response to 2014/2015 cholera outbreak, ministry of health and partners made a decision to assess the feasibility and acceptability of conducting a mass oral cholera vaccine (OCV) as an additional public health measure. This paper highlights the burden of the 2014/15 cholera outbreak, successes and challenges of OCV campaign conducted in March and April 2015. Methods This was a documentation of the first OCV campaign conducted in Malawi. The campaign targeted over 160,000 people aged one year or more living in 19 camps of people internally displaced by floods and their surrounding communities in Nsanje district. It was a reactive campaign as additional measure to improved water, sanitation and hygiene in response to the laboratory confirmed cholera outbreak. Results During the first round of the OCV campaign conducted from 30 March to 4 April 2015, a total of 156,592 (97.6%) people out of 160,482 target population received OCV. During the second round (20 to 25 April 2015), a total of 137,629 (85.8%) people received OCV. Of these, 108,247 (67.6%) people received their second dose while 29,382 (18.3%) were their first dose. Of the 134,836 people with known gender and sex who received 1 or 2 doses, 54.4% were females and over half (55.4%) were children under the age of 15 years. Among 108,237 people who received 2 doses (fully immunized), 54.4% were females and 51.9% were children under 15 years of age. No severe adverse event following immunization was reported. The main reason for non-vaccination or failure to take the 2 doses was absence during the period of the campaign. Conclusion This documentation has demonstrated that it was feasible, acceptable by the community to conduct a large-scale mass OCV campaign in Malawi within five

  3. Adult Attachment Ratings (AAR): An Item Response Theory Analysis

    PubMed Central

    Pilkonis, Paul A.; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q.

    2013-01-01

    The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6–16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships–Revised (ECR–R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR–R, informant ratings on the ECR–R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores. PMID:24033268

  4. Adult Attachment Ratings (AAR): an item response theory analysis.

    PubMed

    Pilkonis, Paul A; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q

    2014-01-01

    The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6-16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships-Revised (ECR-R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR-R, informant ratings on the ECR-R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores.

  5. Acceptance and commitment therapy group-treatment for non-responsive patients with personality disorders: An exploratory study.

    PubMed

    Chakhssi, Farid; Janssen, Wim; Pol, Silvia M; van Dreumel, Malinda; Westerhof, Gerben J

    2015-11-01

    Patients with personality disorders who did not respond to previous outpatient treatment are among the most challenging patients to treat and are often referred to specialized settings. Acceptance and commitment therapy (ACT) is an innovative therapy that has shown effectiveness in treatment-resistant cases with chronic or recurrent depression with or without co-morbid personality disorders. The central role that ACT accords to positive values and experiential avoidance may enhance treatment responsivity in patients with personality disorders that did not respond to previous treatments. The current nonrandomized study explored the effectiveness of a 26-week ACT-based group treatment (n = 60) for personality disorders compared to treatment-as-usual (n = 21) based on cognitive behaviour therapy (CBT-TAU) at a specialized setting for patients with personality disorders. Individuals in both treatment conditions demonstrated small to moderate decreases in general psychological functioning and personality pathology. There was no main effect of therapy condition. Overall, results suggest that ACT is a possible treatment option for individuals with difficult-to-treat personality pathology and further outcome research is warranted.

  6. Vitamin d deficiency reduces the immune response, phagocytosis rate, and intracellular killing rate of microglial cells.

    PubMed

    Djukic, Marija; Onken, Marie Luise; Schütze, Sandra; Redlich, Sandra; Götz, Alexander; Hanisch, Uwe-Karsten; Bertsch, Thomas; Ribes, Sandra; Hanenberg, Andrea; Schneider, Simon; Bollheimer, Cornelius; Sieber, Cornel; Nau, Roland

    2014-06-01

    Meningitis and meningoencephalitis caused by Escherichia coli are associated with high rates of mortality and neurological sequelae. A high prevalence of neurological disorders has been observed in geriatric populations at risk of hypovitaminosis D. Vitamin D has potent effects on human immunity, including induction of antimicrobial peptides (AMPs) and suppression of T-cell proliferation, but its influence on microglial cells is unknown. The purpose of the present study was to determine the effects of vitamin D deficiency on the phagocytosis rate, intracellular killing, and immune response of murine microglial cultures after stimulation with the Toll-like receptor (TLR) agonists tripalmitoyl-S-glyceryl-cysteine (TLR1/2), poly(I·C) (TLR3), lipopolysaccharide (TLR4), and CpG oligodeoxynucleotide (TLR9). Upon stimulation with high concentrations of TLR agonists, the release of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) was decreased in vitamin D-deficient compared to that in vitamin D-sufficient microglial cultures. Phagocytosis of E. coli K1 after stimulation of microglial cells with high concentrations of TLR3, -4, and -9 agonists and intracellular killing of E. coli K1 after stimulation with high concentrations of all TLR agonists were lower in vitamin D-deficient microglial cells than in the respective control cells. Our observations suggest that vitamin D deficiency may impair the resistance of the brain against bacterial infections. PMID:24686054

  7. Vitamin D Deficiency Reduces the Immune Response, Phagocytosis Rate, and Intracellular Killing Rate of Microglial Cells

    PubMed Central

    Onken, Marie Luise; Schütze, Sandra; Redlich, Sandra; Götz, Alexander; Hanisch, Uwe-Karsten; Bertsch, Thomas; Ribes, Sandra; Hanenberg, Andrea; Schneider, Simon; Bollheimer, Cornelius; Sieber, Cornel; Nau, Roland

    2014-01-01

    Meningitis and meningoencephalitis caused by Escherichia coli are associated with high rates of mortality and neurological sequelae. A high prevalence of neurological disorders has been observed in geriatric populations at risk of hypovitaminosis D. Vitamin D has potent effects on human immunity, including induction of antimicrobial peptides (AMPs) and suppression of T-cell proliferation, but its influence on microglial cells is unknown. The purpose of the present study was to determine the effects of vitamin D deficiency on the phagocytosis rate, intracellular killing, and immune response of murine microglial cultures after stimulation with the Toll-like receptor (TLR) agonists tripalmitoyl-S-glyceryl-cysteine (TLR1/2), poly(I·C) (TLR3), lipopolysaccharide (TLR4), and CpG oligodeoxynucleotide (TLR9). Upon stimulation with high concentrations of TLR agonists, the release of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) was decreased in vitamin D-deficient compared to that in vitamin D-sufficient microglial cultures. Phagocytosis of E. coli K1 after stimulation of microglial cells with high concentrations of TLR3, -4, and -9 agonists and intracellular killing of E. coli K1 after stimulation with high concentrations of all TLR agonists were lower in vitamin D-deficient microglial cells than in the respective control cells. Our observations suggest that vitamin D deficiency may impair the resistance of the brain against bacterial infections. PMID:24686054

  8. Heart rate responses to Taekwondo training in experienced practitioners.

    PubMed

    Bridge, Craig A; Jones, Michelle A; Hitchen, Peter; Sanchez, Xavier

    2007-08-01

    The purpose of this study was to evaluate the heart rate (HR) responses of specific Taekwondo training activities, practiced by experienced practitioners in a natural training environment. Eight male experienced Taekwondo practitioners, with 3- 13 years (5.4 +/- 3.2 years) experience took part in a 5-day Taekwondo training camp. Continuous HR measures were recorded at 5-second intervals during 6 training sessions; each session was observed and notated, and a diary of training activities was recorded. The HR responses were assimilated into 8 fundamental training activities for analysis: elastics, technical combinations, step sparring, pad work, forms, basic techniques and forms, sparring drills, and free sparring. Taekwondo training elicited HR into 64.7-81.4% of HR maximum (%HRmax). Moderate relative exercise intensities (64.7-69.4%HRmax) were elicited by elastics, technical combinations, and step sparring. The remaining 5 training activities elicited hard relative exercise intensities (74.7-81.4%HRmax). One-way repeated-measures analysis of variance with post hoc analysis revealed that elastics, technical combinations, and step sparring elicited significantly lower relative intensities than the remaining training activities (p < 0.05). Furthermore, forms, basic techniques and forms, sparring drills, and free sparring elicited significantly higher relative intensities than the remaining training activities (p < 0.05). In conclusion, all Taekwondo training activities in this study seemed suitable for cardiovascular conditioning, although different training activities stressed the cardiovascular system to different degrees. Practically, this suggests coaches need to structure Taekwondo training sessions based not only on the technical and tactical needs of practitioners but also in a manner that enables sufficient cardiovascular conditioning for competition.

  9. Running demands and heart rate response in rugby sevens referees.

    PubMed

    Suarez-Arrones, Luis; Calvo-Lluch, África; Portillo, Javier; Sánchez, Francisco; Mendez-Villanueva, Alberto

    2013-06-01

    The purpose of this study was to examine for the first time the match running demands and heart rate (HR) responses associated with elite rugby sevens referees. Twelve referees were analyzed over 38 games, using Global Positioning System. Referees covered an average distance of 1665.2 ± 203.5 m per game (15.1 ± 0.5 minutes). Over this distance, 22.3% (371.8 ± 48.9 m) was spent standing and walking, 25.9% (431.2 ± 92.6 m) jogging, 12.4% (206.5 ± 53.2 m) cruising, 23.8% (395.6 ± 94.3 m) striding, 8% (133.3 ± 61.6 m) high-intensity running, and 7.6% (126.7 ± 87.3 m) sprinting. The average maximal distance of sprints, the number of sprints, and the mean sprint distance over the game were 31.3 ± 13.4 m, 5.76 ± 3.6 sprints, and 19.9 ± 7.8 m, respectively. The referee's work-to-rest ratio was 3.5:1. There were no statistical differences between the first and second half in any of the running variables analyzed. The average HR in the second half (160 ± 9 b·min(-1); 86 ± 5% maximal heart rate (HRmax) of the estimated) was higher (p < 0.05) than the HR recorded in the first half (154 ± 11 b·min(-1); 83 ± 6% of the estimated HRmax). This study also suggests that the physical demands of referring in rugby sevens are quite different from those encountered in other rugby codes, and the training regimes need to meet the increased overall running demands and high-intensity running activity.

  10. Comparing Response Rates in E-Mail and Paper Surveys: A Meta-Analysis

    ERIC Educational Resources Information Center

    Shih, Tse-Hua; Fan, Xitao

    2009-01-01

    This meta-analysis examined 35 study results within last 10 years that directly compared the response rates of e-mail versus mail surveys. Individual studies reported inconsistent findings concerning the response rate difference between e-mail and mail surveys, but e-mail surveys generally have lower response rate (about 20% lower on the average)…

  11. Effects of Personalization and Invitation Email Length on Web-Based Survey Response Rates

    ERIC Educational Resources Information Center

    Trespalacios, Jesús H.; Perkins, Ross A.

    2016-01-01

    Individual strategies to increase response rate and survey completion have been extensively researched. Recently, efforts have been made to investigate a combination of interventions to yield better response rates for web-based surveys. This study examined the effects of four different survey invitation conditions on response rate. From a large…

  12. Running demands and heart rate response in rugby union referees.

    PubMed

    Suarez-Arrones, Luis; Portillo, Luis J; García, Jose M; Calvo-Lluch, Africa; Roberts, Simon P; Mendez-Villanueva, Alberto

    2013-11-01

    The aim of this study was to examine the match physical demands and exercise intensity associated with men rugby union refereeing using global positioning system technology. Ten male rugby union referees (age, 37.1 ± 5.9 years; body mass, 83.7 ± 4.8 kg; height, 175.5 ± 6.2 cm) were analyzed 2-4 times during a total of 30 national level matches. The average total distance covered by the referees throughout the game was 6,322.2 ± 564.9 m. As a percentage of total distance, 37.3% (2,356.9 ± 291.3 m) was spent walking, 24.1% (1,524.4 ± 229.4 m) jogging, 10.4% (656.2 ± 130.7 m) running at low intensity, 17.6% (1,110.3 ± 212.2 m) at medium intensity, 5.5% (347.1 ± 27.1 m) at high intensity, and 5.2% (328.1 ± 230.3 m) at sprint. A significant decrease (p < 0.05) in running performance was observed between the first and the second halves in the last 3 speed zones. When the total distance traveled during consecutive 10-minute periods was compared, there was a significantly greater distance covered in the first 10 minutes of the game (876.3 ± 163 m) compared with 50-60 minutes (679.8 ± 117.6 m), 60-70 minutes (713.03 ± 122.3 m), and 70-80 minutes (694.2 ± 125.7 m; all p < 0.05). The average heart rate responses were similar (p > 0.05) in the first (157 ± 7 b · min; 85% HRmax) and second half (155 ± 7 b · min; 84% HRmax). This study provides evidence of reduced high-intensity running toward the end of the game. These findings offer important information to design better training strategies adapted to the requirements and demands of rugby union refereeing.

  13. Soil formation in response to perturbed erosion rates

    NASA Astrophysics Data System (ADS)

    Mudd, Simon; Milodowski, David; Yoo, Kyungsoo; Gabet, Emmanuel; Weinman, Beth; Attal, Mikael; Clubb, Fiona

    2014-05-01

    Time is recognized as one of the soil forming factors. In upland, sloping landscapes time is controlled by erosion rates. These erosion rates may be forced by climate, tectonics, and increasingly anthropogenic disturbance. Perturbations to erosion rates alter the exposure of near surface material to both physical and chemical weathering, which can influence water retention, plant growth and sediment transport. All of these can feed back into further perturbation of erosion rates. Here we present field data, topographic analysis and numerical modelling from a field site in the Sierra Nevada of California where we have attempted to examine soil formation across a range of erosion rates, and determine their influence on soil particle size, geochemistry and plant life, as well as the geomorphic signature of overland flow. Erosion rates have strong impact on soils, leading to coarser soils that support less biomass when erosion rates are high and clay rich soils with higher biomass when erosion rates are low. Erosion rates also appear to influence the dissection of the landscape by channels, which we quantify using high resolution topographic analysis.

  14. Yield response to variable rate irrigation in corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To investigate the impact of variable rate irrigation on corn yield, twenty plots of corn were laid out under a center pivot variable rate irrigation (VRI) system in an experimental field near Stoneville, MS. The VRI system is equipped with five VRI zone control units, a global positioning system (G...

  15. Children's Heart Rate Reactivity Responses to Three School Tasks.

    ERIC Educational Resources Information Center

    Sharpley, Christopher F.; And Others

    1989-01-01

    Investigated effects of 3 routine classroom arithmetic and reading tasks upon the heart rate reactivity of 30 fifth grade children. Results indicated that some children showed large increases in heart rates during the three tasks, and that these children should be considered at risk for coronary heart disease. (Author/TE)

  16. Boring in response to bark and phloem extracts from North American trees does not explain host acceptance behavior of Orthotomicus erosus (Coleoptera: Scolytidae).

    PubMed

    Walter, Abigail J; Kells, Stephen A; Venette, Robert C; Seybold, Steven J

    2010-04-01

    When invasive herbivorous insects encounter novel plant species, they must determine whether the novel plants are hosts. The Mediterranean pine engraver, Orthotomicus erosus (Wollaston), an exotic bark beetle poised to expand its range in North America, accepts hosts after contacting the bark. To test the hypothesis that O. erosus accepts hosts on the basis of gustatory cues, we prepared bark and phloem extracts from logs of four North American tree species that we had used in previous host acceptance experiments. Water, methanol, and hexane extracts of red pine, tamarack, balsam fir, and paper birch were presented alone and in combination on a neutral filter paper substrate in a section of a plastic drinking straw. Boring behavior in response to the three-extract combinations differed from the pattern of acceptance previously observed among species when the beetles were in contact with the bark surface. Only the aqueous extracts of tamarack, Larix laricina, increased the initiation and the extent of boring by O. erosus on the filter paper substrate. We conclude that the effects of extracted chemicals do not match the behavior of the beetles observed when penetrating excised bark and phloem discs, indicating that host selection by O. erosus may not be predictable from bark and phloem chemistry alone. Instead, host acceptance may be determined by nongustatory stimuli or by a combination of stimuli including gustatory and nongustatory cues.

  17. The influence of sensor orientation on activity-based rate responsive pacing. Sensor Orientation Study Group.

    PubMed

    Theres, H; Philippon, F; Melzer, C; Combs, W; Prest-Berg, K

    1998-11-01

    Piezoelectric activity-based rate responsive pacemakers are commonly implanted with the sensor facing inward. This study was conducted to assess the safe and effective rate response of an activity-based rate responsive pacemaker implanted with the sensor facing outward. A comparison were made to a previously studied patient group with sensor facing inward. Patient and pacemaker data was collected at predischarge and 2-month follow-up. Two-minute hall walks in conjunction with programmer-assisted rate response assessment were utilized to standardize initial rate response parameter settings for both patient groups. At 2-month follow-up, sensor rate response to a stage 3 limited CAEP protocol was recorded. Adequate sensor rate response was achieved for both patient groups. No difference was noted in reported patient complications for both groups. A statistically significant difference in programmed rate response curve setting and activity threshold for the two groups was noted at 2-month follow-up. Adequate sensor rate response was achieved for a patient population implanted with an activity-based rate responsive pacemaker with sensor facing outward. In this orientation, one higher rate response curve setting and an activity threshold one value more sensitive were required on average when compared to the normal sensor orientation group. PMID:9826862

  18. Reading Assessment Methods for Middle-School Students: An Investigation of Reading Comprehension Rate and Maze Accurate Response Rate

    ERIC Educational Resources Information Center

    Hale, Andrea D.; Henning, Jaime B.; Hawkins, Renee O.; Sheeley, Wesley; Shoemaker, Larissa; Reynolds, Jennifer R.; Moch, Christina

    2011-01-01

    This study was designed to investigate the validity of four different aloud reading comprehension assessment measures: Maze, comprehension questions, Maze accurate response rate (MARR), and reading comprehension rate (RCR). The criterion measures used in this study were the Woodcock-Johnson III Tests of Achievement (WJ-III ACH) Broad Reading…

  19. Reliability of Heart Rate Responses at Given Ratings of Perceived Exertion in Cycling and Walking

    ERIC Educational Resources Information Center

    Katsanos, Christos S.; Moffatt, Robert J.

    2005-01-01

    Eleven healthy men (M age = 27 years, SD = 4) completed three cycling and three walking trials in an alternating order. During each trial, participants were allowed, within 3 min, to adjust the work rate to correspond to given rating of perceived exertion (RPE) values according to the following order: RPE 11, 13, and 15. For cycling as well as…

  20. Increasing response rates to postal questionnaires: systematic review

    PubMed Central

    Edwards, Phil; Roberts, Ian; Clarke, Mike; DiGuiseppi, Carolyn; Pratap, Sarah; Wentz, Reinhard; Kwan, Irene

    2002-01-01

    Objective To identify methods to increase response to postal questionnaires. Design Systematic review of randomised controlled trials of any method to influence response to postal questionnaires. Studies reviewed 292 randomised controlled trials including 258 315 participants Intervention reviewed 75 strategies for influencing response to postal questionnaires. Main outcome measure The proportion of completed or partially completed questionnaires returned. Results The odds of response were more than doubled when a monetary incentive was used (odds ratio 2.02; 95% confidence interval 1.79 to 2.27) and almost doubled when incentives were not conditional on response (1.71; 1.29 to 2.26). Response was more likely when short questionnaires were used (1.86; 1.55 to 2.24). Personalised questionnaires and letters increased response (1.16; 1.06 to 1.28), as did the use of coloured ink (1.39; 1.16 to 1.67). The odds of response were more than doubled when the questionnaires were sent by recorded delivery (2.21; 1.51 to 3.25) and increased when stamped return envelopes were used (1.26; 1.13 to 1.41) and questionnaires were sent by first class post (1.12; 1.02 to 1.23). Contacting participants before sending questionnaires increased response (1.54; 1.24 to 1.92), as did follow up contact (1.44; 1.22 to 1.70) and providing non-respondents with a second copy of the questionnaire (1.41; 1.02 to 1.94). Questionnaires designed to be of more interest to participants were more likely to be returned (2.44; 1.99 to 3.01), but questionnaires containing questions of a sensitive nature were less likely to be returned (0.92; 0.87 to 0.98). Questionnaires originating from universities were more likely to be returned than were questionnaires from other sources, such as commercial organisations (1.31; 1.11 to 1.54). Conclusions Health researchers using postal questionnaires can improve the quality of their research by using the strategies shown to be effective in this systematic review

  1. Effects of Reinforcement, Punishment, and Feedback Upon Academic Response Rate

    ERIC Educational Resources Information Center

    Walker, Hill M.; Buckley, Nancy K.

    1972-01-01

    Results of this study provided indirect support for Marshall's (1965) Hypothesis with regard to the informational versus motivational properties of punishment (punishment of specific responses has discriminative or informative value, whereas punishment applied to the situation may have primary motivational value). (Author)

  2. Effects of Vibration and G-Loading on Heart Rate, Breathing Rate, and Response Time

    NASA Technical Reports Server (NTRS)

    Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.

    2013-01-01

    Aerospace and applied environments commonly expose pilots and astronauts to G-loading and vibration, alone and in combination, with well-known sensorimotor (Cohen, 1970) and performance consequences (Adelstein et al., 2008). Physiological variables such as heart rate (HR) and breathing rate (BR) have been shown to increase with G-loading (Yajima et al., 1994) and vibration (e.g. Guignard, 1965, 1985) alone. To examine the effects of G-loading and vibration, alone and in combination, we measured heart rate and breathing rate under aerospace-relevant conditions (G-loads of 1 Gx and 3.8 Gx; vibration of 0.5 gx at 8, 12, and 16 Hz).

  3. Response rates for CBT for anxiety disorders: Need for standardized criteria.

    PubMed

    Loerinc, Amanda G; Meuret, Alicia E; Twohig, Michael P; Rosenfield, David; Bluett, Ellen J; Craske, Michelle G

    2015-12-01

    Full appreciation of the effectiveness of cognitive behavioral therapy (CBT) requires both effect size data and individual rates of positive response. Response rates are particularly helpful for clinicians when choosing among treatment options. However, systematic reviews on cross-study response rates have not been conducted, possibly due to the absence of a standardized metric for calculating response rates. We conducted a systematic review of the treatment outcome literature to determine overall response rates to CBT for anxiety disorders and whether current methods of defining treatment response influence overall response rates. Our database search (2000-2014) resulted in 87 studies that reported response rates and included at least one CBT condition. Results showed that overall treatment response rates across anxiety disorders averaged 49.5% at post-treatment and 53.6% at follow-up. Response rates varied significantly as a function of the properties used to define them. Measures that incorporated more than one criterion, the combination of a reliable change index with a clinical cutoff (a clinically significant change), and intent-to-treat samples yielded lower response rates at post-treatment. Blinded independent assessors yielded higher response rates than unblinded assessors. Based on previous empirical and theoretical work, we recommend that future studies use a clinically significant change index, in an intent-to-treat analysis (using a mixed-model approach), reflecting multiple modalities, and assessed by independent blinded assessors. Our results indicate that such measures are likely to reduce response rates, but may result in a less biased and more accurate representation of improvement and achievement of normative functioning.

  4. Oligodendroglial response to ionizing radiation: Dose and dose-rate response

    SciTech Connect

    Levy, R.P.

    1991-01-01

    An in vitro system using neuroglia from neonatal rat brain was developed to examining the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute [gamma]-radiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. It was concluded that oligodendrocytes in irradiated cultures had significantly lower functional capacity than did unirradiated controls. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. At DIC 14, the group irradiated in a single fraction had significantly lower oligodendrocyte counts than any group given split doses; all irradiated cultures had marked depression of MBP synthesis, but to significant differences referable to time interval between doses. At DIC 21, cultures irradiated at intervals of 0 h to 2 h had similar oligodendrocyte counts to one another, but these counts were significantly lower than in cultures irradiated at intervals of 4 h to 6 h; MBP levels remained depressed at DIC 21 for all irradiated cultures. The oligodendrocyte response to dose rate (0.03 to 1.97 Gy/min) was evaluated at DIC 14 and DIC 21. Exposure at 0.03 Gy/min suppressed oligodendrocyte counts at DIC 21 less than did higher dose rates in 5-Gy irradiated cultures.

  5. Occasional Reinforced Responses during Extinction Can Slow the Rate of Reacquisition of an Operant Response

    ERIC Educational Resources Information Center

    Woods, Amanda M.; Bouton, Mark E.

    2007-01-01

    Three experiments with rats examined reacquisition of an operant response after either extinction or a response-elimination procedure that included occasional reinforced responses during extinction. In each experiment, reacquisition was slower when response elimination had included occasional reinforced responses, although the effect was…

  6. High Strain Rate Response of Sandwich Composites with Nanophased Cores

    NASA Astrophysics Data System (ADS)

    Mahfuz, Hassan; Uddin, Mohammed F.; Rangari, Vijaya K.; Saha, Mrinal C.; Zainuddin, Shaik; Jeelani, Shaik

    2005-05-01

    Polyurethane foam materials have been used as core materials in a sandwich construction with S2-Glass/SC-15 facings. The foam material has been manufactured from liquid polymer precursors of polyurethane. The precursors are made of two components; part-A (diphenylmethane diisocyanate) and part-B (polyol). In one set of experiments, part-A was mixed with part-B to manufacture the foam. In another set, TiO2 nanoparticles have been dispersed in part-A through ultrasonic cavitation technique. The loading of nanoparticles was 3% by weight of the total polymer precursor. The TiO2 nanoparticles were spherical in shape, and were about 29 nm in diameter. Sonic cavitation was carried out with a vibrasound liquid processor at 20 kHz frequency with a power intensity of about 100 kW/m2. The two categories of foams manufactured in this manner were termed as neat and nanophased. Sandwich composites were then fabricated using these two categories of core materials using a co-injection resin transfer molding (CIRTM) technique. Test samples extracted from the panel were subjected to quasi-static as well as high strain rate loadings. Rate of loading varied from 0.002 s-1 to around 1300 s-1. It has been observed that infusion of nanoparticles had a direct correlation with the cell geometry. The cell dimensions increased by about 46% with particle infusion suggesting that nanoparticles might have worked as catalysts during the foaming process. Correspondingly, enhancement in thermal properties was also noticed especially in the TGA experiments. There was also a significant improvement in mechanical properties due to nanoparticle infusion. Average increase in sandwich strength and energy absorption with nanophased cores was between 40 60% over their neat counterparts. Details of manufacturing and analyses of thermal and mechanical tests are presented in this paper.

  7. 42 CFR 137.285 - Are Self-Governance Tribes required to accept Federal environmental responsibilities to enter...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Federal environmental responsibilities to enter into a construction project agreement? 137.285 Section 137... that would apply if the Secretary were to undertake a construction project, but only those responsibilities directly related to the completion of the construction project being assumed....

  8. 42 CFR 137.285 - Are Self-Governance Tribes required to accept Federal environmental responsibilities to enter...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Federal environmental responsibilities to enter into a construction project agreement? 137.285 Section 137... that would apply if the Secretary were to undertake a construction project, but only those responsibilities directly related to the completion of the construction project being assumed....

  9. 42 CFR 137.285 - Are Self-Governance Tribes required to accept Federal environmental responsibilities to enter...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Federal environmental responsibilities to enter into a construction project agreement? 137.285 Section 137... that would apply if the Secretary were to undertake a construction project, but only those responsibilities directly related to the completion of the construction project being assumed....

  10. Assessing the role of alternative response rates and reinforcer rates in resistance to extinction of target responding when combining stimuli.

    PubMed

    Podlesnik, Christopher A; Bai, John Y H; Skinner, Katherine A

    2016-05-01

    Studies of behavioral momentum reveal that reinforcing an alternative response in the presence of a target response reduces the rate of target responding but increases its persistence, relative to training the target response on its own. Because of the parallels between these studies and differential-reinforcement techniques to reduce problem behavior in clinical settings, alternative techniques to reduce problem behavior without enhancing its persistence are being explored. One potential solution is to train an alternative response in a separate stimulus context from problem behavior before combining the alternative stimulus with the target stimulus. The present study assessed how differences in reinforcement contingencies and rate for alternative responding influenced resistance to extinction of target responding when combining alternative and target stimuli in pigeons. Across three experiments, alternative stimuli signaling a response-reinforcer dependency and greater reinforcer rates more effectively decreased the persistence of target responding when combining alternative and target stimuli within the same extinction tests, but not when compared across separate extinction tests. Overall, these findings reveal that differences in competition between alternative and target responding produced by contingencies of alternative reinforcement could influence the effectiveness of treating problem behavior through combining stimulus contexts. PMID:27193243

  11. Assessing the role of alternative response rates and reinforcer rates in resistance to extinction of target responding when combining stimuli.

    PubMed

    Podlesnik, Christopher A; Bai, John Y H; Skinner, Katherine A

    2016-05-01

    Studies of behavioral momentum reveal that reinforcing an alternative response in the presence of a target response reduces the rate of target responding but increases its persistence, relative to training the target response on its own. Because of the parallels between these studies and differential-reinforcement techniques to reduce problem behavior in clinical settings, alternative techniques to reduce problem behavior without enhancing its persistence are being explored. One potential solution is to train an alternative response in a separate stimulus context from problem behavior before combining the alternative stimulus with the target stimulus. The present study assessed how differences in reinforcement contingencies and rate for alternative responding influenced resistance to extinction of target responding when combining alternative and target stimuli in pigeons. Across three experiments, alternative stimuli signaling a response-reinforcer dependency and greater reinforcer rates more effectively decreased the persistence of target responding when combining alternative and target stimuli within the same extinction tests, but not when compared across separate extinction tests. Overall, these findings reveal that differences in competition between alternative and target responding produced by contingencies of alternative reinforcement could influence the effectiveness of treating problem behavior through combining stimulus contexts.

  12. Characterization of Nonlinear Rate Dependent Response of Shape Memory Polymers

    NASA Technical Reports Server (NTRS)

    Volk, Brent; Lagoudas, Dimitris C.; Chen, Yi-Chao; Whitley, Karen S.

    2007-01-01

    the material while it was above its glass transition temperature. After deforming the material to a specified applied strain, the material was then cooled to below the glass transition temperature (Tg) while retaining the deformed shape. Finally, the specimen was heated again to above the transition temperature, and the resulting shape recovery profile was measured. Results show that strain recovery occurs at a nonlinear rate with respect to time. Results also indicate that the ratio of recoverable strain/applied strain increases as the applied strain increases.

  13. Survey Response Rates and Survey Administration in Counseling and Clinical Psychology: A Meta-Analysis

    ERIC Educational Resources Information Center

    Van Horn, Pamela S.; Green, Kathy E.; Martinussen, Monica

    2009-01-01

    This article reports results of a meta-analysis of survey response rates in published research in counseling and clinical psychology over a 20-year span and describes reported survey administration procedures in those fields. Results of 308 survey administrations showed a weighted average response rate of 49.6%. Among possible moderators, response…

  14. Research on Mail Surveys: Response Rates and Methods in Relation to Population Group and Time.

    ERIC Educational Resources Information Center

    Boser, Judith A.; Green, Kathy

    The purpose of this review was to look for trends across time in response rates and variables studied for published mail surveys and to compare response rates and variables studied for different target populations. Studies were identified in databases in four fields: education, psychology, business and marketing, and sociology. A total of 225…

  15. Tactics to Increase Course Evaluation Response Rates: A Comparison of Effectiveness

    ERIC Educational Resources Information Center

    Jacek, Laura

    2015-01-01

    When an institution decides to move to online teaching evaluations, they often face concerns that their response rates will fall with the change. This fear need never come to pass, however. There are many interventions that can raise response rates. Good communication strategies, improved student and faculty engagement, and grade hold are just a…

  16. Improving Flow Response of a Variable-rate Aerial Application System by Interactive Refinement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to evaluate response of a variable-rate aerial application controller to changing flow rates and to improve its response at correspondingly varying system pressures. System improvements have been made by refinement of the control algorithms over time in collaboration with ...

  17. Effects of high, low, and thinning rates of alternative reinforcement on response elimination and resurgence.

    PubMed

    Sweeney, Mary M; Shahan, Timothy A

    2013-07-01

    A common treatment for operant problem behavior is alternative reinforcement. When alternative reinforcement is removed or reduced, however, resurgence of the target behavior can occur. Shahan and Sweeney (2011) developed a quantitative model of resurgence based on behavioral momentum theory that suggests higher rates of alternative reinforcement result in faster response elimination and greater resurgence when removed, whereas lower rates of alternative reinforcement result in slower response elimination but are followed by less resurgence. Thus, the present study was designed to examine whether faster target response elimination and less resurgence could be achieved by beginning with a high rate of alternative reinforcement and gradually thinning it such that a low rate is ultimately removed during a simulated treatment lapse. Results showed that high rates of alternative reinforcement were more effective than low or thinning rates at target response suppression but resulted in resurgence when discontinued. Low and thinning rates, on the other hand, were less effective at response suppression but target responding did not increase when alternative reinforcement was discontinued. The quantitative model cannot currently account for the finding that lower-rate alternative reinforcement may not effectively disrupt behavior relative to an extinction only control. Relative advantages of high, low, thinning, or no alternative reinforcement are discussed with respect to suppression of target response rate during treatment, resurgence when alternative reinforcement is removed, and alternative response persistence, while taking into account differences between this animal model and modern applied behavior analytic treatments.

  18. Effects of high, low, and thinning rates of alternative reinforcement on response elimination and resurgence.

    PubMed

    Sweeney, Mary M; Shahan, Timothy A

    2013-07-01

    A common treatment for operant problem behavior is alternative reinforcement. When alternative reinforcement is removed or reduced, however, resurgence of the target behavior can occur. Shahan and Sweeney (2011) developed a quantitative model of resurgence based on behavioral momentum theory that suggests higher rates of alternative reinforcement result in faster response elimination and greater resurgence when removed, whereas lower rates of alternative reinforcement result in slower response elimination but are followed by less resurgence. Thus, the present study was designed to examine whether faster target response elimination and less resurgence could be achieved by beginning with a high rate of alternative reinforcement and gradually thinning it such that a low rate is ultimately removed during a simulated treatment lapse. Results showed that high rates of alternative reinforcement were more effective than low or thinning rates at target response suppression but resulted in resurgence when discontinued. Low and thinning rates, on the other hand, were less effective at response suppression but target responding did not increase when alternative reinforcement was discontinued. The quantitative model cannot currently account for the finding that lower-rate alternative reinforcement may not effectively disrupt behavior relative to an extinction only control. Relative advantages of high, low, thinning, or no alternative reinforcement are discussed with respect to suppression of target response rate during treatment, resurgence when alternative reinforcement is removed, and alternative response persistence, while taking into account differences between this animal model and modern applied behavior analytic treatments. PMID:23605776

  19. [Response rates in three opinion surveys performed through online questionnaires in the health setting].

    PubMed

    Aerny Perreten, Nicole; Domínguez-Berjón, Ma Felicitas; Astray Mochales, Jenaro; Esteban-Vasallo, María D; Blanco Ancos, Luis Miguel; Lópaz Pérez, Ma Ángeles

    2012-01-01

    The main advantages of online questionnaires are the speed of data collection and cost savings, but response rates are usually low. This study analyzed response rates and associated factors among health professionals in three opinion surveys in the autonomous region of Madrid. The participants, length of the questionnaire and topic differed among the three surveys. The surveys were conducted by using paid Internet software. The institutional e-mail addresses of distinct groups of health professionals were used. Response rates were highest in hospitals (up to 63%) and administrative services and were lowest in primary care (less than 33%). The differences in response rates were analyzed in primary care professionals according to age, sex and professional category and only the association with age was statistically significant. None of the surveys achieved a response rate of 60%. Differences were observed according to workplace, patterns of Internet usage, and interest in the subject.

  20. In Search of the Optimal Number of Response Categories in a Rating Scale

    ERIC Educational Resources Information Center

    Lee, Jihyun; Paek, Insu

    2014-01-01

    Likert-type rating scales are still the most widely used method when measuring psychoeducational constructs. The present study investigates a long-standing issue of identifying the optimal number of response categories. A special emphasis is given to categorical data, which were generated by the Item Response Theory (IRT) Graded-Response Modeling…

  1. Variable-ratio versus variable-interval schedules: response rate, resistance to change, and preference.

    PubMed

    Nevin, J A; Randolph; Holland, S; McLean, A P

    2001-07-01

    Two experiments asked whether resistance to change depended on variable-ratio as opposed to variable-interval contingencies of reinforcement and the different response rates they establish. In Experiment 1, pigeons were trained on multiple random-ratio random-interval schedules with equated reinforcer rates. Baseline response rates were disrupted by intercomponent food, extinction, and prefeeding. Resistance to change relative to baseline was greater in the interval component, and the difference was correlated with the extent to which baseline response rates were higher in the ratio component. In Experiment 2, pigeons were trained on multiple variable-ratio variable-interval schedules in one half of each session and on concurrent chains in the other half in which the terminal links corresponded to the multiple-schedule components. The schedules were varied over six conditions, including two with equated reinforcer rates. In concurrent chains, preference strongly overmatched the ratio of obtained reinforcer rates. In multiple schedules, relative resistance to response-independent food during intercomponent intervals, extinction, and intercomponent food plus extinction depended on the ratio of obtained reinforcer rates but was less sensitive than was preference. When reinforcer rates were similar, both preference and relative resistance were greater for the variable-interval schedule, and the differences were correlated with the extent to which baseline response rates were higher on the variable-ratio schedule, confirming the results of Experiment 1. These results demonstrate that resistance to change and preference depend in part on response rate as well as obtained reinforcer rate, and challenge the independence of resistance to change and preference with respect to response rate proposed by behavioral momentum theory.

  2. Variable-ratio versus variable-interval schedules: response rate, resistance to change, and preference.

    PubMed Central

    Nevin, J A; Randolph; Holland, S; McLean, A P

    2001-01-01

    Two experiments asked whether resistance to change depended on variable-ratio as opposed to variable-interval contingencies of reinforcement and the different response rates they establish. In Experiment 1, pigeons were trained on multiple random-ratio random-interval schedules with equated reinforcer rates. Baseline response rates were disrupted by intercomponent food, extinction, and prefeeding. Resistance to change relative to baseline was greater in the interval component, and the difference was correlated with the extent to which baseline response rates were higher in the ratio component. In Experiment 2, pigeons were trained on multiple variable-ratio variable-interval schedules in one half of each session and on concurrent chains in the other half in which the terminal links corresponded to the multiple-schedule components. The schedules were varied over six conditions, including two with equated reinforcer rates. In concurrent chains, preference strongly overmatched the ratio of obtained reinforcer rates. In multiple schedules, relative resistance to response-independent food during intercomponent intervals, extinction, and intercomponent food plus extinction depended on the ratio of obtained reinforcer rates but was less sensitive than was preference. When reinforcer rates were similar, both preference and relative resistance were greater for the variable-interval schedule, and the differences were correlated with the extent to which baseline response rates were higher on the variable-ratio schedule, confirming the results of Experiment 1. These results demonstrate that resistance to change and preference depend in part on response rate as well as obtained reinforcer rate, and challenge the independence of resistance to change and preference with respect to response rate proposed by behavioral momentum theory. PMID:11516115

  3. Smaller hospitals accept advertising.

    PubMed

    Mackesy, R

    1988-07-01

    Administrators at small- and medium-sized hospitals gradually have accepted the role of marketing in their organizations, albeit at a much slower rate than larger institutions. This update of a 1983 survey tracks the increasing competitiveness, complexity and specialization of providing health care and of advertising a small hospital's services. PMID:10288550

  4. The relation between auditory-nerve temporal responses and perceptual rate integration in cochlear implants

    PubMed Central

    Hughes, Michelle L.; Baudhuin, Jacquelyn L.; Goehring, Jenny L.

    2014-01-01

    The purpose of this study was to examine auditory-nerve temporal response properties and their relation to psychophysical threshold for electrical pulse trains of varying rates (“rate integration”). The primary hypothesis was that better rate integration (steeper slope) would be correlated with smaller decrements in ECAP amplitude as a function of stimulation rate (shallower slope of the amplitude-rate function), reflecting a larger percentage of the neural population contributing more synchronously to each pulse in the train. Data were obtained for 26 ears in 23 cochlear-implant recipients. Electrically evoked compound action potential (ECAP) amplitudes were measured in response to each of 21 pulses in a pulse train for the following rates: 900, 1200, 1800, 2400, and 3500 pps. Psychophysical thresholds were obtained using a 3-interval, forced-choice adaptive procedure for 300-ms pulse trains of the same rates as used for the ECAP measures, which formed the rate-integration function. For each electrode, the slope of the psychophysical rate-integration function was compared to the following ECAP measures: (1) slope of the function comparing average normalized ECAP amplitude across pulses versus stimulation rate (“adaptation”), (2) the rate that produced the maximum alternation depth across the pulse train, and (3) rate at which the alternating pattern ceased (stochastic rate). Results showed no significant relations between the slope of the rate-integration function and any of the ECAP measures when data were collapsed across subjects. However, group data showed that both threshold and average ECAP amplitude decreased with increased stimulus rate, and within-subject analyses showed significant positive correlations between psychophysical thresholds and mean ECAP response amplitudes across the pulse train. These data suggest that ECAP temporal response patterns are complex and further study is required to better understand the relative contributions of

  5. The relation between auditory-nerve temporal responses and perceptual rate integration in cochlear implants.

    PubMed

    Hughes, Michelle L; Baudhuin, Jacquelyn L; Goehring, Jenny L

    2014-10-01

    The purpose of this study was to examine auditory-nerve temporal response properties and their relation to psychophysical threshold for electrical pulse trains of varying rates ("rate integration"). The primary hypothesis was that better rate integration (steeper slope) would be correlated with smaller decrements in ECAP amplitude as a function of stimulation rate (shallower slope of the amplitude-rate function), reflecting a larger percentage of the neural population contributing more synchronously to each pulse in the train. Data were obtained for 26 ears in 23 cochlear-implant recipients. Electrically evoked compound action potential (ECAP) amplitudes were measured in response to each of 21 pulses in a pulse train for the following rates: 900, 1200, 1800, 2400, and 3500 pps. Psychophysical thresholds were obtained using a 3-interval, forced-choice adaptive procedure for 300-ms pulse trains of the same rates as used for the ECAP measures, which formed the rate-integration function. For each electrode, the slope of the psychophysical rate-integration function was compared to the following ECAP measures: (1) slope of the function comparing average normalized ECAP amplitude across pulses versus stimulation rate ("adaptation"), (2) the rate that produced the maximum alternation depth across the pulse train, and (3) rate at which the alternating pattern ceased (stochastic rate). Results showed no significant relations between the slope of the rate-integration function and any of the ECAP measures when data were collapsed across subjects. However, group data showed that both threshold and average ECAP amplitude decreased with increased stimulus rate, and within-subject analyses showed significant positive correlations between psychophysical thresholds and mean ECAP response amplitudes across the pulse train. These data suggest that ECAP temporal response patterns are complex and further study is required to better understand the relative contributions of adaptation

  6. Response rate viewed as engagement bouts: effects of relative reinforcement and schedule type.

    PubMed Central

    Shull, R L; Gaynor, S T; Grimes, J A

    2001-01-01

    The rate of a reinforced response is conceptualized as a composite of engagement bouts (visits) and responding during visits. Part I of this paper describes a method for estimating the rate of visit initiations and the average number of responses per visit from log survivor plots: the proportion) of interresponse times (IRTs) longer than some elapsed time (log scale) plotted as a function of elapsed time. In Part 2 the method is applied to IRT distributions from rats that obtained food pellets by nose poking a lighted key under various multiple schedules of reinforcement. As expected, total response rate increased as a function of (a) increasing the rate of reinforcement (i.e., variable-interval [VI] 4 min vs. VI 1 mi), (b) increasing the amount of the reinforcer (one food pellet vs. four pellets), (c) increasing the percentage of reinforcers that were contingent on nose poking (25% vs. 100%), and (d) requiring additional responses after the end of the VI schedule (i.e., adding a tandem variable-ratio [VR] 9 requirement). The first three of these variables (relative reinforcement) increased the visit-initiation rate. The tandem VR, in contrast, increased the number of responses per visit. Thus, variables that have similar effects on total response rate can be differentiated based on their effects on the componemts of response rate. PMID:11453618

  7. The impact of vaccine failure rate on epidemic dynamics in responsive networks

    NASA Astrophysics Data System (ADS)

    Liang, Yu-Hao; Juang, Jonq

    2015-04-01

    An SIS model based on the microscopic Markov-chain approximation is considered in this paper. It is assumed that the individual vaccination behavior depends on the contact awareness, local and global information of an epidemic. To better simulate the real situation, the vaccine failure rate is also taken into consideration. Our main conclusions are given in the following. First, we show that if the vaccine failure rate α is zero, then the epidemic eventually dies out regardless of what the network structure is or how large the effective spreading rate and the immunization response rates of an epidemic are. Second, we show that for any positive α, there exists a positive epidemic threshold depending on an adjusted network structure, which is only determined by the structure of the original network, the positive vaccine failure rate and the immunization response rate for contact awareness. Moreover, the epidemic threshold increases with respect to the strength of the immunization response rate for contact awareness. Finally, if the vaccine failure rate and the immunization response rate for contact awareness are positive, then there exists a critical vaccine failure rate αc > 0 so that the disease free equilibrium (DFE) is stable (resp., unstable) if α < αc (resp., α > αc). Numerical simulations to see the effectiveness of our theoretical results are also provided.

  8. Physiological, Behavioral, and Histological Responses of Male C57BL/6N Mice to Different CO2 Chamber Replacement Rates.

    PubMed

    Boivin, Gregory P; Bottomley, Michael A; Dudley, Emily S; Schiml, Patricia A; Wyatt, Christopher N; Grobe, Nadja

    2016-01-01

    Rodent euthanasia with CO2 by using gradual displacement of 10% to 30% of the chamber volume per minute is considered acceptable by the AVMA Panel on Euthanasia. However, whether a 50% to 100% chamber replacement rate (CRR) of CO2 is more painful or distressful than 10% to 30% CRR is unclear. Therefore, we examined physiological and behavioral parameters, corticosterone and ACTH levels, and lung histology of mice euthanized at CRR of 15%, 30%, 50%, or 100%. Adult male C57BL/6N mice were euthanized at different CO2 CRR as physiological parameters were recorded telemetrically. Video recordings were reviewed to determine when the mouse first became ataxic, when it was fully recumbent (characterized by the mouse's nose resting on the cage floor), and when breathing stopped. Overall, CO2 euthanasia increased cardiovascular parameters and activity. Specific significant differences that were associated with 50% to 100% compared with 15% to 30% CO2 CRR included an increase in systolic blood pressure per second from initiation of CO2 until ataxia, a decrease in total diastolic blood pressure until ataxia, and a decrease in total heart rate until ataxia, immobility, and death. All physiological responses occurred more rapidly with higher CRR. Activity levels, behavioral responses, plasma adrenocorticotropic hormone and corticosterone levels, and lung pathology were not different between groups. We found no physiological, behavioral, or histologic evidence that 15% or 30% CO2 CRR is less painful or distressful than is 50% or 100% CO2 CRR. We conclude that 50% to 100% CO2 CRR is acceptable for euthanizing adult male C57BL/6N mice. PMID:27423153

  9. Modeling of human Heart Rate response during walking, cycling and rowing.

    PubMed

    Baig, Dur-E-Zehra; Su, Hao; Cheng, Teddy M; Savkin, Andrey V; Su, Steven W; Celler, Branko G

    2010-01-01

    The aim of this paper is to study the human Heart Rate (HR) response during walking, cycling and rowing exercises using linear time varying (LTV) models. We used the frequency of exercise locomotion as the input to the model. This frequency characterizes the stride rate, cadence rate and strokes rate of the walking, cycling and rowing exercises respectively. The time varying parameters in the LTV models were estimated by the Kalman Filter (KF). The results in this study demonstrate that HR responses to these exercises exhibit some degree of time varying nature.

  10. The functional response predicts the effect of resource distribution on the optimal movement rate of consumers.

    PubMed

    Calcagno, Vincent; Grognard, Frédéric; Hamelin, Frédéric M; Wajnberg, Éric; Mailleret, Ludovic

    2014-12-01

    Understanding how often individuals should move when foraging over patchy habitats is a central question in ecology. By combining optimality and functional response theories, we show analytically how the optimal movement rate varies with the average resource level (enrichment) and resource distribution (patch heterogeneity). We find that the type of functional response predicts the effect of enrichment in homogeneous habitats: enrichment should decrease movement for decelerating functional responses, but increase movement for accelerating responses. An intermediate resource level thus maximises movement for type-III responses. Counterintuitively, greater movement costs favour an increase in movement. In heterogeneous habitats predictions further depend on how enrichment alters the variance of resource distribution. Greater patch variance always increases the optimal rate of movement, except for type-IV functional responses. While the functional response is well established as a fundamental determinant of consumer-resource dynamics, our results indicate its importance extends to the understanding of individual movement strategies.

  11. Congruence between Spouses’ Perceptions and Observers’ Ratings of Responsiveness: The Role of Attachment Avoidance

    PubMed Central

    Beck, Lindsey A.; Pietromonaco, Paula R.; DeVito, Cassandra C.; Powers, Sally I.; Boyle, Alysia M.

    2016-01-01

    Although close relationships require partners to depend on one another for mutual responsiveness, avoidantly-attached individuals are especially averse to risking such dependency. The authors propose that both avoidant and non-avoidant individuals perceive signs of their own and their partners’ responsiveness in ways that reflect motivated perceptions of dependency. The present research examined how the interplay between spouses’ attachment avoidance and observed responsive behaviors during marital conflict shaped perceptions of their own and their partners’ responsiveness. Newlywed couples attempted to resolve a relationship conflict, then reported perceptions of their own and their partners’ responsiveness during the conflict. Observers also coded both partners’ responsive behaviors during the conflict. Avoidant husbands perceived themselves as less responsive than did observers; avoidant wives’ perceptions that their husbands were less responsive matched observers’ ratings. The discussion highlights the role of gender role norms in understanding links between attachment and responsiveness. PMID:24132245

  12. Reexamining traditional issues in survey research: Just how evil is the anathema of low response rate?

    SciTech Connect

    Clark, S.B.

    1995-08-01

    Survey researchers have long been exhorted to strive for high response rates in order to maximize the likelihood that the respondents are representative of the population being surveyed. It is not surprising then, that much survey research has been directed towards examining the effects of various manipulatable factors on response rate. It is clear that attempts to reach the goal of minimizing the likelihood of nonresponse bias through testing various methods of increasing survey response rates have consumed much research and debate. The results obtained in this research have been inconsistent. Some studies have found significant differences, others have found none. The present study was designed to determine the extent to which the results of an employment survey of former graduates of a teacher preparation program would have been affected by changes in response rate.

  13. Relationship between response rates and measures of reinforcing strength using a choice procedure in monkeys.

    PubMed

    Banks, Matthew L; Gould, Robert W; Czoty, Paul W; Nader, Michael A

    2008-07-01

    Concurrent schedules of reinforcement are increasingly being used to investigate the reinforcing strength of abused drugs. A purported advantage of concurrent schedules is that the primary dependent measure, percentage of responses emitted on the drug-associated manipulandum, is independent of the rate-altering effects of drugs. Data supporting this hypothesis are, however, rarely presented, which was one goal of this study. In addition, we tested the hypothesis that drug-induced decreases in response rates provides an additional index to characterize abuse liability of drugs. This study examined the relationship between response rate and response allocation (i.e. drug choice) when 3,4-methylenedioxymethamphetamine (MDMA, 0.03-0.3 mg/kg/inj) or cocaine (0.003-0.1 mg/kg/inj) was the alternative to food under concurrent fixed-ratio reinforcement schedules in rhesus (n=4) and cynomolgus (n=16) monkeys, respectively. Increasing doses of MDMA or cocaine resulted in increased drug choice and dose-dependent decreases in overall response rates. For both drugs, response rates on the drug-associated lever were not affected by dose and were not different from saline. Furthermore, at most doses, rates of responding on the food-associated lever were significantly higher than response rates on the drug-associated lever. Finally, MDMA but not cocaine decreased food-reinforced responding, providing evidence for potential differences between the drugs. These results demonstrate that under concurrent food-drug reinforcement schedules, response rates on the drug-associated lever are independent of measures of reinforcement, whereas disruptions in food-maintained responding may be inversely related to abuse liability. PMID:18622187

  14. Effect of Ethanol and Methyl-tert-Butyl Ether on Monoaromatic Hydrocarbon Biodegradation: Response Variability for Different Aquifer Materials Under Various Electron-Accepting Conditions

    SciTech Connect

    Ruiz-Aguilar, G L; Fernandez-Sanchez, J M; Kane, S R; Kim, D; Alvarez, P J

    2003-10-06

    Aquifer microcosms were used to determine how ethanol and methyl-tert-butyl ether (MtBE) affect monoaromatic hydrocarbon degradation under different electron-accepting conditions commonly found in contaminated sites experiencing natural attenuation. Response variability was investigated by using aquifer material from four sites with different exposure history. The lag phase prior to BTEX (benzene, toluene, ethylbenzene, and xylenes) and ethanol degradation was typically shorter in microcosms with previously contaminated aquifer material, although previous exposure did not always result in high degradation activity. Toluene was degraded in all aquifer materials and generally under a broader range of electron-accepting conditions compared to benzene, which was degraded only under aerobic conditions. MtBE was not degraded within 100 days under any condition, and it did not affect BTEX or ethanol degradation patterns. Ethanol was often degraded before BTEX compounds, and had a variable effect on BTEX degradation as a function of electron-accepting conditions and aquifer material source. An occasional enhancement of toluene degradation by ethanol occurred in denitrifying microcosms with unlimited nitrate; this may be attributable to the fortuitous growth of toluene-degrading bacteria during ethanol degradation. Nevertheless, experiments with flow-through aquifer columns showed that this beneficial effect could be eclipsed by an ethanol-driven depletion of electron acceptors, which significantly inhibited BTEX degradation and is probably the most important mechanism by which ethanol could hinder BTEX natural attenuation. A decrease in natural attenuation could increase the likelihood that BTEX compounds reach a receptor as well as the potential duration of exposure.

  15. Dynamics of the instantaneous firing rate in response to changes in input statistics.

    PubMed

    Fourcaud-Trocmé, Nicolas; Brunel, Nicolas

    2005-06-01

    We review and extend recent results on the instantaneous firing rate dynamics of simplified models of spiking neurons in response to noisy current inputs. It has been shown recently that the response of the instantaneous firing rate to small amplitude oscillations in the mean inputs depends in the large frequency limit f on the spike initiation dynamics. A particular simplified model, the exponential integrate-and-fire (EIF) model, has a response that decays as 1/f in the large frequency limit and describes very well the response of conductance-based models with a Hodgkin-Huxley type fast sodium current. Here, we show that the response of the EIF instantaneous firing rate also decays as 1/f in the case of an oscillation in the variance of the inputs for both white and colored noise. We then compute the initial transient response of the firing rate of the EIF model to a step change in its mean inputs and/or in the variance of its inputs. We show that in both cases the response speed is proportional to the neuron stationary firing rate and inversely proportional to a 'spike slope factor' Delta(T) that controls the sharpness of spike initiation: as 1/Delta(T) for a step change in mean inputs, and as 1/Delta(T) (2) for a step change in the variance in the inputs.

  16. A nonlinear dynamic model for heart rate response to treadmill walking exercise.

    PubMed

    Cheng, Teddy M; Savkin, Andrey V; Celler, Branko G; Wang, Lu; Su, Steven W

    2007-01-01

    A dynamic model of the heart rate response to treadmill walking exercise is presented. The model is a feedback interconnected system; the subsystem in the forward path represents the neural response to exercise, while the subsystem in the feedback path describes the peripheral local response. The parameters of the model were estimated from 5 healthy adult male subjects, each undertaking 3 sets of walking exercise at different speeds. Simulated responses from the model closely match the experimental data both in the exercise and the recovery phases. The model will be useful in explaining the cardiovascular response to exercise and in the design of exercise protocols for individuals.

  17. Should age-period-cohort analysts accept innovation without scrutiny? A response to Reither, Masters, Yang, Powers, Zheng and Land.

    PubMed

    Bell, Andrew; Jones, Kelvyn

    2015-03-01

    This commentary clarifies our original commentary (Bell and Jones, 2014c) and illustrates some concerns we have regarding the response article in this issue (Reither et al., 2015). In particular, we argue that (a) linear effects do not have to be produced by exact linear mathematical functions to behave as if they were linear, (b) linear effects by this wider definition are extremely common in real life social processes, and (c) in the presence of these effects, the Hierarchical Age Period Cohort (HAPC) model will often not work. Although Reither et al. do not define what a 'non-linear monotonic trend' is (instead, only stating that it isn't a linear effect) we show that the model often doesn't work in the presence of such effects, by using data generated as a 'non-linear monotonic trend' by Reither et al. themselves. We then question their discussion of fixed and random effects before finishing with a discussion of how we argue that theory should be used, in the context of the obesity epidemic.

  18. Stuttered and Fluent Speakers' Heart Rate and Skin Conductance in Response to Fluent and Stuttered Speech

    ERIC Educational Resources Information Center

    Zhang, Jianliang; Kalinowski, Joseph; Saltuklaroglu, Tim; Hudock, Daniel

    2010-01-01

    Background: Previous studies have found simultaneous increases in skin conductance response and decreases in heart rate when normally fluent speakers watched and listened to stuttered speech compared with fluent speech, suggesting that stuttering induces arousal and emotional unpleasantness in listeners. However, physiological responses of persons…

  19. Heart Rate Complexity in Response to Upright Tilt in Persons with Down Syndrome

    ERIC Educational Resources Information Center

    Agiovlasitis, Stamatis; Baynard, Tracy; Pitetti, Kenneth H.; Fernhall, Bo

    2011-01-01

    People with Down syndrome (DS) show altered autonomic response to sympatho-excitation. Cardiac autonomic modulation may be examined with heart rate (HR) complexity which is associated uniquely with cardiovascular risk. This study examined whether the response of HR complexity to passive upright tilt differs between persons with and without DS and…

  20. Effects Of Reinforcement History On Response Rate And Response Pattern In Periodic Reinforcement

    PubMed Central

    López, Florente; Menez, Marina

    2005-01-01

    Several researchers have suggested that conditioning history may have long-term effects on fixed-interval performances of rats. To test this idea and to identify possible factors involved in temporal control development, groups of rats initially were exposed to different reinforcement schedules: continuous, fixed-time, and random-interval. Afterwards, half of the rats in each group were studied on a fixed-interval 30-s schedule of reinforcement and the other half on a fixed-interval 90-s schedule of reinforcement. No evidence of long-term effects attributable to conditioning history on either response output or response patterning was found; history effects were transitory. Different tendencies in trajectory across sessions were observed for measures of early and late responding within the interreinforcer interval, suggesting that temporal control is the result of two separate processes: one involved in response output and the other in time allocation of responding and not responding. PMID:16047607

  1. Effects of Corporate Social Responsibility and Governance on Its Credit Ratings

    PubMed Central

    Kim, Dong-young

    2014-01-01

    This study reviews the impact of corporate social responsibility (CSR) and corporate governance on its credit rating. The result of regression analysis to credit ratings with relevant primary independent variables shows that both factors have significant effects on it. As we have predicted, the signs of both regression coefficients have a positive sign (+) proving that corporates with excellent CSR and governance index (CGI) scores have higher credit ratings and vice versa. The results show nonfinancial information also may have effects on corporate credit rating. The investment on personal data protection could be an example of CSR/CGI activities which have positive effects on corporate credit ratings. PMID:25401134

  2. Effects of corporate social responsibility and governance on its credit ratings.

    PubMed

    Kim, Dong-young; Kim, JeongYeon

    2014-01-01

    This study reviews the impact of corporate social responsibility (CSR) and corporate governance on its credit rating. The result of regression analysis to credit ratings with relevant primary independent variables shows that both factors have significant effects on it. As we have predicted, the signs of both regression coefficients have a positive sign (+) proving that corporates with excellent CSR and governance index (CGI) scores have higher credit ratings and vice versa. The results show nonfinancial information also may have effects on corporate credit rating. The investment on personal data protection could be an example of CSR/CGI activities which have positive effects on corporate credit ratings. PMID:25401134

  3. Effects of corporate social responsibility and governance on its credit ratings.

    PubMed

    Kim, Dong-young; Kim, JeongYeon

    2014-01-01

    This study reviews the impact of corporate social responsibility (CSR) and corporate governance on its credit rating. The result of regression analysis to credit ratings with relevant primary independent variables shows that both factors have significant effects on it. As we have predicted, the signs of both regression coefficients have a positive sign (+) proving that corporates with excellent CSR and governance index (CGI) scores have higher credit ratings and vice versa. The results show nonfinancial information also may have effects on corporate credit rating. The investment on personal data protection could be an example of CSR/CGI activities which have positive effects on corporate credit ratings.

  4. "I am not alone": the feasibility and acceptability of interactive voice response-facilitated telephone peer support among older adults with heart failure.

    PubMed

    Heisler, Michele; Halasyamani, Lakshmi; Resnicow, Kenneth; Neaton, Marie; Shanahan, Jan; Brown, Stephanie; Piette, John D

    2007-01-01

    Patient self-management is a critical determinant of heart failure (HF) outcomes, yet patients with HF are often frail and socially isolated, factors that may limit their ability to manage self-care and access clinic-based services. Mobilizing peer support among HF patients is a promising strategy to improve self-management support. In this pilot, the authors evaluated the feasibility and acceptability of an interactive voice response (IVR)-based platform to facilitate telephone peer support among older adults with HF. Participants completed a baseline survey, were offered a 3-hour training session in peer communication skills, and were paired with another patient who had HF. Participants were asked to contact their partner weekly using a toll-free IVR phone system that protected their anonymity and provided automated reminders if contacts were not made. Times and duration of participants' telephone contacts were monitored and recorded. After the 7-week intervention, participants completed surveys and brief face-to-face interviews. The authors found high levels of use and satisfaction and improvements in depressive symptoms among the 20 pilot study participants. An IVR peer-support intervention is feasible, is acceptable to patients, and may have positive effects on patients' HF social support and health outcomes, in conjunction with structured health system support, that warrant more rigorous evaluation in a randomized trial. PMID:17541307

  5. High Strain Rate Response Testing with the Split Hopkinson Pressure Bar Technique

    NASA Astrophysics Data System (ADS)

    Zwiessler, R.; Kenkmann, T.; Poelchau, M. H.; Nau, S.; Hess, S.

    2016-08-01

    We present a newly developed split Hopkinson pressure bar which is used to quantify the rate dependent uniaxial stress-strain response of rocks in the high strain rate regime as well as results of our first study on a sandstone and Carrara marble.

  6. Cardio-Respiratory and Perceived Exertion Responses to Different Cranking Rates during Maximal Arm Ergometry.

    ERIC Educational Resources Information Center

    Israel, Richard G.; And Others

    This study compared cardio-respiratory and perceived exertion responses for four cranking rates (50, 60, 70 and 80 rpm) during a continuous maximal arm ergometry protocol in order to determine the most efficient cranking rate for maximal testing. Fifteen male volunteers from 18-30 years of age performed a continuous arm ergometry stress test in…

  7. Become a Survey Sophisticate: Learn How to Tweak Alumni Surveys to Increase Response Rates

    ERIC Educational Resources Information Center

    Pearson, Jerold

    2011-01-01

    The online survey is a popular tool for taking the pulse of an alumni body. However, response rates for these surveys have been declining over the years, making them potentially less useful. Are there easy ways to increase these rates? The author has conducted a number of experiments to try to find that out. He discusses surveys that explored…

  8. Influences Behind Neutral Responses in Subordinate Ratings of Supervisors: A Methodological Note.

    ERIC Educational Resources Information Center

    Ghorpade, Jai; Lackritz, James R.

    1981-01-01

    A sample (N=416) of assembly-line operators were asked to rate their supervisors according to an instrument which contained a list of positive supervisory traits and behaviors. Three rating options were provided: agree, don't know, and disagree. Dissatisfied raters were found to give significantly more neutral responses than satisfied raters.…

  9. The Effects of Using Colored Paper To Boost Response-Rates to Surveys and Questionnaires.

    ERIC Educational Resources Information Center

    Hartley, James; Rutherford, Andrew

    2003-01-01

    Carries out a meta-analysis to see if there might be a positive effect for colored paper overall on survey result rates. Finds no significant differences between the response rates to white and to colored paper in general. Notes that when considering separately the most common colors used, it appeared that pink paper had the greatest effect. (SG)

  10. Response of fish to different simulated rates of water temperature increase

    SciTech Connect

    Wike, L.D.; Tuckfield, R.C.

    1992-08-01

    We initiated this study to define the limits of effluent-temperature rate increases during reactor restart, which will help minimize fish kills. We constructed an apparatus for exposing fish to various temperature-increase regimens and conducted two experiments based on information from system tests and scoping runs. In the rate experiment, we acclimated the fish to 20{degree}C, and then raised the temperature to 40{degree}C at varying rates. Because scoping runs and literature suggested that acclimation temperature may affect temperature-related mortality, we conducted an acclimation experiment. We acclimated the fish to various temperatures, then raised the temperatures to 39--40{degree}C at a rate of 2{degree}C every 12 hours. Based on the analysis of the data, we recommend temperature-increase rates during reactor restart of 2.5{degree}C every nine hours if ambient water temperatures are over 20{degree}C. If water temperatures are at or below 20{degree}C, we recommend temperature-increase rates of 2.5{degree}C every 12 hours. No regulation of temperature is required after effluent temperatures reach 40{degree}C. We recommend further studies, including expanded testing with the simulation system and behavioral and bioenergetic investigations that may further refine acceptable rates of effluent-temperature increases.

  11. Effect of mildly attenuated heart rate response during treadmill exercise testing on cardiovascular outcome in healthy men and women.

    PubMed

    Maor, Elad; Kopel, Eran; Sidi, Yechezkel; Goldenberg, Ilan; Segev, Shlomo; Kivity, Shaye

    2013-11-01

    Attenuated heart rate (HR) response during exercise is associated with adverse cardiovascular outcome. The acceptable value for HR response is 85% of the age-predicted maximal HR (APMHR). This study hypothesized that mild attenuation of HR response during exercise among healthy subjects is associated with increased cardiovascular risk. The study population comprised 10,323 healthy men and women without known cardiovascular disease (CVD) or diabetes mellitus who underwent a yearly screening program and were followed up during a mean period of 4.3 years. Participants were grouped to 3 tertiles based on the percentage of their APMHR reached at the baseline stress test. The primary end point was the occurrence of CVD or cerebrovascular disease. A total of 1,015 incident cases of CVD occurred during follow-up. A multivariate Cox proportional hazards regression model showed that the CVD risk of subjects who reached 60% to 96% of their APMHR was 35% greater compared with those who reached their APMHR (p = 0.001). A subgroup analysis among subjects who reached 85% of their APMHR showed that even mildly attenuated heart response (in the range of 85% to 96% APMHR) was independently associated with 36% increase in CVD risk (p <0.001). In conclusion, attenuated HR response during exercise is a powerful and independent predictor of adverse cardiovascular events during long-term follow-up among healthy men and women. The prognostic implications of attenuated HR response in this population are apparent even with a minor decrease of the maximal HR to <96% of the APMHR.

  12. Micro-Structural Response of DP 600 to High Strain Rate Deformation

    NASA Technical Reports Server (NTRS)

    Hamburg, Brian; Schneider, Judy; Jones, Stanley E.

    2008-01-01

    The object of this study was to investigate the micro-structural response of DP 600 subjected to high strain rate, ballistic impact tests. The ballistic tests were conducted using normal impact of a hardened steel penetrator into a 2 mm thick sheet of DP 600. The average strain rates produced from this test method are on the order of 10(exp 5)/s. Electron microscopy was used to investigate the microstructure before and after high strain rate deformation. A variation in material response was observed between tests conducted at 0.8 x 105 and 25 x 10(exp 5)/s.

  13. Academic response rate as a function of teacher- and self-imposed contingencies1

    PubMed Central

    Lovitt, Thomas C.; Curtiss, Karen A.

    1969-01-01

    The purpose of this study was to assess the effects of the contingency manager (teacher or pupil) on a pupil's academic response rate. The results of two such experiments disclosed that higher academic rates occurred when the pupil arranged the contingency requirements than when the teacher specified them. A third study manipulated only reinforcement magnitude to ascertain whether amount of reinforcement had interacted with pupil-specified contingencies to produce the increase in academic response rate. The latter findings revealed that the contingency manager, not reinforcement magnitude, accounted for this subject's gain in performance. PMID:16795202

  14. Functional, fractal nonlinear response with application to rate processes with memory, allometry, and population genetics

    PubMed Central

    Vlad, Marcel O.; Morán, Federico; Popa, Vlad T.; Szedlacsek, Stefan E.; Ross, John

    2007-01-01

    We give a functional generalization of fractal scaling laws applied to response problems as well as to probability distributions. We consider excitations and responses, which are functions of a given state vector. Based on scaling arguments, we derive a general nonlinear response functional scaling law, which expresses the logarithm of a response at a given state as a superposition of the values of the logarithms of the excitations at different states. Such a functional response law may result from the balance of different growth processes, characterized by variable growth rates, and it is the first order approximation of a perturbation expansion similar to the phase expansion. Our response law is a generalization of the static fractal scaling law and can be applied to the study of various problems from physics, chemistry, and biology. We consider some applications to heterogeneous and disordered kinetics, organ growth (allometry), and population genetics. Kinetics on inhomogeneous reconstructing surfaces leads to rate equations described by our nonlinear scaling law. For systems with dynamic disorder with random energy barriers, the probability density functional of the rate coefficient is also given by our scaling law. The relative growth rates of different biological organs (allometry) can be described by a similar approach. Our scaling law also emerges by studying the variation of macroscopic phenotypic variables in terms of genotypic growth rates. We study the implications of the causality principle for our theory and derive a set of generalized Kramers–Kronig relationships for the fractal scaling exponents. PMID:17360340

  15. Dynamic brain mapping of behavior change: tracking response initiation and inhibition to changes in reinforcement rate.

    PubMed

    Schlund, Michael W; Magee, Sandy; Hudgins, Caleb D

    2012-10-01

    Adaptive behavior change is supported by executive control processes distributed throughout a prefrontal-striatal-parietal network. Yet, the temporal dynamics of regions in the network have not been characterized. Using functional magnetic resonance imaging (fMRI), we tracked changes brain activation while subjects initiated and inhibited responding in accordance with changes in reinforcement rate. During imaging, subjects completed a free-operant task that involved repeated transitions between fixed-ratio reinforcement and extinction (RF:EXT), where reinforcement rate decreased and responding was inhibited, and between extinction and fixed-ratio reinforcement (EXT:RF), where reinforcement rate increased and responding was initiated. Our whole-brain temporal assessment revealed that transitions which required initiating and inhibiting responding prompted positive phasic responses in a prefrontal-parietal network, the insula and thalamus. However, response initiation prompted by an increase in reinforcement rate during the EXT:RF transition elicited positive phasic responses in reward-sensitive striatal regions. Furthermore, response inhibition prompted by a decrease in reinforcement rate during the RF:EXT transition elicited negative phasic responses in ventral frontal regions sensitive to value and contingency. Our findings highlight the temporal dynamics of a brain network that supports behavioral changes (initiation and inhibition) resulting from changes in local reinforcement rates.

  16. The effects of digitizing rate and phase distortion errors on the shock response spectrum

    NASA Technical Reports Server (NTRS)

    Wise, J. H.

    1983-01-01

    Some of the methods used for acquisition and digitization of high-frequency transients in the analysis of pyrotechnic events, such as explosive bolts for spacecraft separation, are discussed with respect to the reduction of errors in the computed shock response spectrum. Equations are given for maximum error as a function of the sampling rate, phase distortion, and slew rate, and the effects of the characteristics of the filter used are analyzed. A filter is noted to exhibit good passband amplitude, phase response, and response to a step function is a compromise between the flat passband of the elliptic filter and the phase response of the Bessel filter; it is suggested that it be used with a sampling rate of 10f (5 percent).

  17. Does age matter? The influence of age on response rates in a mixed-mode survey

    USGS Publications Warehouse

    Gigliotti, Larry M.; Dietsch, Alia

    2014-01-01

    The appeal of cost savings and faster results has fish and wildlife management agencies considering the use of Internet surveys instead of traditional mail surveys to collect information from their constituents. Internet surveys, however, may suffer from differential age-related response rates, potentially producing biased results if certain age groups respond to Internet surveys differently than they do to mail surveys. We examined this concern using data from a mixed-mode angler survey conducted in South Dakota following the 2011 fishing season. Results indicated that young anglers (16–18) had the lowest return rates and senior anglers (65+) had the highest, regardless of survey mode. Despite this consistency in response rates, we note two concerns: (a) lower Internet response rates and (b) different age groups represented by the Internet and mail survey samples differed dramatically. Findings indicate that constituent groups may be represented differently with the use of various survey modes.

  18. Acceptability of human risk.

    PubMed Central

    Kasperson, R E

    1983-01-01

    This paper has three objectives: to explore the nature of the problem implicit in the term "risk acceptability," to examine the possible contributions of scientific information to risk standard-setting, and to argue that societal response is best guided by considerations of process rather than formal methods of analysis. Most technological risks are not accepted but are imposed. There is also little reason to expect consensus among individuals on their tolerance of risk. Moreover, debates about risk levels are often at base debates over the adequacy of the institutions which manage the risks. Scientific information can contribute three broad types of analyses to risk-setting deliberations: contextual analysis, equity assessment, and public preference analysis. More effective risk-setting decisions will involve attention to the process used, particularly in regard to the requirements of procedural justice and democratic responsibility. PMID:6418541

  19. Anger responses to psychosocial stress predict heart rate and cortisol stress responses in men but not women.

    PubMed

    Lupis, Sarah B; Lerman, Michelle; Wolf, Jutta M

    2014-11-01

    While previous research has suggested that anger and fear responses to stress are linked to distinct sympathetic nervous system (SNS) stress responses, little is known about how these emotions predict hypothalamus-pituitary-adrenal (HPA) axis reactivity. Further, earlier research primarily relied on retrospective self-report of emotion. The current study aimed at addressing both issues in male and female individuals by assessing the role of anger and fear in predicting heart rate and cortisol stress responses using both self-report and facial coding analysis to assess emotion responses. We exposed 32 healthy students (18 female; 19.6±1.7 yr) to an acute psychosocial stress paradigm (TSST) and measured heart rate and salivary cortisol levels throughout the protocol. Anger and fear before and after stress exposure was assessed by self-report, and video recordings of the TSST were assessed by a certified facial coder to determine emotion expression (FACS). Self-reported emotions and emotion expressions did not correlate (all p>.23). Increases in self-reported fear predicted blunted cortisol responses in men (β=0.41, p=.04). Also for men, longer durations of anger expression predicted exaggerated cortisol responses (β=0.67 p=.004), and more anger incidences predicted exaggerated cortisol and heart rate responses (β=0.51, p=.033; β=0.46, p=.066, resp.). Anger and fear did not predict SNS or HPA activity for females (all p>.23). The current differential self-report and facial coding findings support the use of multiple modes of emotion assessment. Particularly, FACS but not self-report revealed a robust anger-stress association that could have important downstream health effects for men. For women, future research may clarify the role of other emotions, such as self-conscious expressions of shame, for physiological stress responses. A better understanding of the emotion-stress link may contribute to behavioral interventions targeting health-promoting ways of

  20. Oligodendroglial response to ionizing radiation: Dose and dose-rate response

    SciTech Connect

    Levy, R.P.

    1991-12-01

    An in vitro system using neuroglia from neonatal rat brain was developed to examine the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute {gamma}-irradiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. A new compartmental cell model for radiation response in vitro of the oligodendrocyte population is proposed and examined in relation to the potential reaction to radiation injury in the brain.

  1. The numerical response: rate of increase and food limitation in herbivores and predators.

    PubMed Central

    Bayliss, Peter; Choquenot, David

    2002-01-01

    Two types of numerical response function have evolved since Solomon first introduced the term to generalize features of Lotka-Volterra predator-prey models: (i) the demographic numerical response, which links change in consumer demographic rates to food availability; and (ii) the isocline numerical response, which links consumer abundance per se to food availability. These numerical responses are interchangeable because both recognize negative feedback loops between consumer and food abundance resulting in population regulation. We review how demographic and isocline numerical responses have been used to enhance our understanding of population regulation of kangaroos and possums, and argue that their utility may be increased by explicitly accounting for non-equilibrium dynamics (due to environmental variability and/or biological interactions) and the existence of multiple limiting factors. Interferential numerical response functions may help bridge three major historical dichotomies in population ecology (equilibrium versus non-equilibrium dynamics, extrinsic versus intrinsic regulation and demographic versus isocline numerical responses). PMID:12396515

  2. Rate dependent response and failure of a ductile epoxy and carbon fiber reinforced epoxy composite

    SciTech Connect

    Brown, Eric N; Rae, Philip J; Dattelbaum, Dana M; Stahl, David B

    2010-01-01

    An extensive characterization suite has been performed on the response and failure of a ductile epoxy 55A and uniaxial carbon fiber reinforced epoxy composite of IM7 fibers in 55A resin from the quasistatic to shock regime. The quasistatic and intermediate strain rate response, including elastic modulus, yield and failure have are characterized by quasistatic, SHPB, and DMA measurements as a function of fiber orientation and temperature. The high strain rate shock effect of fiber orientation in the composite and response of the pure resin are presented for plate impact experiments. It has previously been shown that at lower impact velocities the shock velocity is strongly dependent on fiber orientation but at higher impact velocity the in-plane and through thickness Hugoniots converge. The current results are compared with previous studies of the shock response of carbon fiber composites with more conventional brittle epoxy matrices. The spall response of the composite is measured and compared with quasistatic fracture toughness measurements.

  3. Mechanical and microstructural response of Ni sub 3 Al at high strain rate and elevated temperatures

    SciTech Connect

    Sizek, H.W.; Gray, G.T. III.

    1990-01-01

    In this paper, the effect of strain rate and temperature on the substructure evolution and mechanical response of Ni{sub 3}Al will be presented. The strain rate response of Ni{sub 3}Al was studied at strain rates from 10{sup {minus}3} s{sup {minus}1} (quasi-static) to 10{sup 4} s{sup {minus}1} using a Split Hopkinson Pressure Bar. The Hopkinson Bar tests were conducted at temperatures ranging from 77K to 1273K. At high strain rates the flow strength increased significantly with increasing temperature, similar to the behavior observed at quasi-static rates. The work hardening rates increased with strain rate and varied with temperatures. The work hardening rates, appeared to be significantly higher than those found for Ni270. The substructure evolution was characterized utilizing TEM. The defect generation and rate sensitivity of Ni{sub 3}Al are also discussed as a function of strain rate and temperature. 15 refs., 4 figs.

  4. Creep Strain and Strain Rate Response of 2219 Al Alloy at High Stress Levels

    NASA Technical Reports Server (NTRS)

    Taminger, Karen M. B.; Wagner, John A.; Lisagor, W. Barry

    1998-01-01

    As a result of high localized plastic deformation experienced during proof testing in an International Space Station connecting module, a study was undertaken to determine the deformation response of a 2219-T851 roll forging. After prestraining 2219-T851 Al specimens to simulate strains observed during the proof testing, creep tests were conducted in the temperature range from ambient temperature to 107 C (225 F) at stress levels approaching the ultimate tensile strength of 2219-T851 Al. Strain-time histories and strain rate responses were examined. The strain rate response was extremely high initially, but decayed rapidly, spanning as much as five orders of magnitude during primary creep. Select specimens were subjected to incremental step loading and exhibited initial creep rates of similar magnitude for each load step. Although the creep rates decreased quickly at all loads, the creep rates dropped faster and reached lower strain rate levels for lower applied loads. The initial creep rate and creep rate decay associated with primary creep were similar for specimens with and without prestrain; however, prestraining (strain hardening) the specimens, as in the aforementioned proof test, resulted in significantly longer creep life.

  5. Biochemical and physiological responses of rice (Oryza sativa L.) grown on different sewage sludge amendments rates.

    PubMed

    Singh, R P; Agrawal, M

    2010-05-01

    Using sewage sludge, a biological residue from sewage treatment processes, in agriculture is an alternative disposal technique of waste. To study the biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments (SSA) rates a field experiment was conducted by mixing sewage sludge at 0, 3, 4.5, 6, 9, 12 kg m(-2) rate to the agricultural soil. Rate of photosynthesis and stomatal conductance increased in plants grown at different SSA rate. Chlorophyll and protein contents also increased due to different SSA rates. Lipid peroxidation, ascorbic acid, peroxidase activity and proline content increased, however, thiol and phenol content decreased in plants grown at different SSA rates. The study concludes that for rice plant sewage sludge amendment in soil may be a good option as plant has adequate heavy metal tolerance mechanism showed by increased rate of photosynthesis and chlorophyll content and various antioxidant levels.

  6. College students' acceptance of potential treatments for ADHD.

    PubMed

    Carter, Stacy L

    2005-08-01

    The purpose of the current study was to investigate the influence that the professional occupation of a consultant making a treatment recommendation may have on college students' (82 women and 52 men) acceptance of a proposed treatment for a child displaying characteristics of Attention Deficit/Hyperactivity Disorder. Consultants were special education teachers, school psychologists, or physicians. The study also examined college students' ratings of treatment acceptability associated with three frequently implemented interventions of either nonspecific medication, token economy with response cost, or time-out for children with characteristics of Attention Deficit/Hyperactivity Disorder. Analysis indicated college students found a token economy intervention was the least acceptable recommendation by a physician.

  7. Response variability to high rates of electric stimulation in retinal ganglion cells.

    PubMed

    Cai, Changsi; Ren, Qiushi; Desai, Neal J; Rizzo, Joseph F; Fried, Shelley I

    2011-07-01

    To improve the quality of prosthetic vision, it is important to understand how retinal neurons respond to electric stimulation. Previous studies present conflicting reports as to the maximum rate at which retinal ganglion cells can "follow" pulse trains, i.e., generate one spike for each pulse of the train. In the present study, we measured the response of 5 different types of rabbit retinal ganglion cells to pulse trains of 100-700 Hz. Surprisingly, we found significant heterogeneity in the ability of different types to follow pulse trains. For example, brisk transient (BT) ganglion cells could reliably follow pulse rates up to 600 pulses per second (PPS). In contrast, other types could not even follow rates of 200 PPS. There was additional heterogeneity in the response patterns across those types that could not follow high-rate trains. For example, some types generated action potentials in response to approximately every other pulse, whereas other types generated one spike per pulse for a few consecutive pulses and then did not generate any spikes in response to the next few pulses. Interestingly, in the types that could not follow high-rate trains, we found a second type of response: many pulses of the train elicited a biphasic waveform with an amplitude much smaller than that of standard action potentials. This small waveform was often observed following every pulse for which a standard spike was not elicited. A possible origin of the small waveform and its implication for effective retinal stimulation are discussed.

  8. Heat Shock Response in Yeast Involves Changes in Both Transcription Rates and mRNA Stabilities

    PubMed Central

    Castells-Roca, Laia; García-Martínez, José; Moreno, Joaquín; Herrero, Enrique; Bellí, Gemma; Pérez-Ortín, José E.

    2011-01-01

    We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25°C to 37°C. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of the yeast genes and it is particularly important in shaping the mRNA profile of the genes belonging to the environmental stress response. In most cases, changes in transcription rates and mRNA stabilities are homodirectional for both parameters, although some interesting cases of antagonist behavior are found. The statistical analysis of gene targets and sequence motifs within the clusters of genes with similar behaviors shows that both transcriptional and post-transcriptional regulons apparently contribute to the general heat stress response by means of transcriptional factors and RNA binding proteins. PMID:21364882

  9. The Neuromodulation of Neuropathic Pain by Measuring Pain Response Rate and Pain Response Duration in Animal

    PubMed Central

    Kim, Jinhyung; Lee, Sung Eun; Shin, Jaewoo; Jung, Hyun Ho; Kim, Sung June

    2015-01-01

    Objective Neuropathic pain causes patients feel indescribable pain. Deep Brain Stimulation (DBS) is one of the treatment methods in neuropathic pain but the action mechanism is still unclear. To study the effect and mechanism of analgesic effects from DBS in neuropathic pain and to enhance the analgesic effect of DBS, we stimulated the ventral posterolateral nucleus (VPL) in rats. Methods To observe the effect from VPL stimulation, we established 3 groups : normal group (Normal group), neuropathic pain group (Pain group) and neuropathic pain+DBS group (DBS group). Rats in DBS group subjected to electrical stimulation and the target is VPL. Results We observed the behavioral changes by DBS in VPL (VPL-DBS) on neuropathic pain rats. In our study, the pain score which is by conventional test method was effectively decreased. In specific, the time of showing withdrawal response from painful stimulation which is not used measuring method in our animal model was also decreased by DBS. Conclusion The VPL is an effective target on pain modulation. Specifically we could demonstrate changes of pain response duration which is not used, and it was also significantly meaningful. We thought that this study would be helpful in understanding the relation between VPL-DBS and neuropathic pain. PMID:25674337

  10. On the Firing Rate Dependency of the Phase Response Curve of Rat Purkinje Neurons In Vitro

    PubMed Central

    Couto, João; Linaro, Daniele; De Schutter, E; Giugliano, Michele

    2015-01-01

    Synchronous spiking during cerebellar tasks has been observed across Purkinje cells: however, little is known about the intrinsic cellular mechanisms responsible for its initiation, cessation and stability. The Phase Response Curve (PRC), a simple input-output characterization of single cells, can provide insights into individual and collective properties of neurons and networks, by quantifying the impact of an infinitesimal depolarizing current pulse on the time of occurrence of subsequent action potentials, while a neuron is firing tonically. Recently, the PRC theory applied to cerebellar Purkinje cells revealed that these behave as phase-independent integrators at low firing rates, and switch to a phase-dependent mode at high rates. Given the implications for computation and information processing in the cerebellum and the possible role of synchrony in the communication with its post-synaptic targets, we further explored the firing rate dependency of the PRC in Purkinje cells. We isolated key factors for the experimental estimation of the PRC and developed a closed-loop approach to reliably compute the PRC across diverse firing rates in the same cell. Our results show unambiguously that the PRC of individual Purkinje cells is firing rate dependent and that it smoothly transitions from phase independent integrator to a phase dependent mode. Using computational models we show that neither channel noise nor a realistic cell morphology are responsible for the rate dependent shift in the phase response curve. PMID:25775448

  11. Effect of the Transcendental Meditation Program on Graduation, College Acceptance and Dropout Rates for Students Attending an Urban Public High School

    ERIC Educational Resources Information Center

    Colbert, Robert D.

    2013-01-01

    High school graduation rates nationally have declined in recent years, despite public and private efforts. The purpose of the current study was to determine whether practice of the Quiet Time/Transcendental Meditation® program at a medium-size urban school results in higher school graduation rates compared to students who do not receive training…

  12. Impacts of environmental variability on desiccation rate, plastic responses and population dynamics of Glossina pallidipes.

    PubMed

    Kleynhans, E; Clusella-Trullas, S; Terblanche, J S

    2014-02-01

    Physiological responses to transient conditions may result in costly responses with little fitness benefits, and therefore, a trade-off must exist between the speed of response and the duration of exposure to new conditions. Here, using the puparia of an important insect disease vector, Glossina pallidipes, we examine this potential trade-off using a novel combination of an experimental approach and a population dynamics model. Specifically, we explore and dissect the interactions between plastic physiological responses, treatment-duration and -intensity using an experimental approach. We then integrate these experimental results from organismal water-balance data and their plastic responses into a population dynamics model to examine the potential relative fitness effects of simulated transient weather conditions on population growth rates. The results show evidence for the predicted trade-off for plasticity of water loss rate (WLR) and the duration of new environmental conditions. When altered environmental conditions lasted for longer durations, physiological responses could match the new environmental conditions, and this resulted in a lower WLR and lower rates of population decline. At shorter time-scales however, a mismatch between acclimation duration and physiological responses was reflected by reduced overall population growth rates. This may indicate a potential fitness cost due to insufficient time for physiological adjustments to take place. The outcomes of this work therefore suggest plastic water balance responses have both costs and benefits, and these depend on the time-scale and magnitude of variation in environmental conditions. These results are significant for understanding the evolution of plastic physiological responses and changes in population abundance in the context of environmental variability.

  13. Dependence of the phototropic response of Arabidopsis thaliana on fluence rate and wavelength

    PubMed Central

    Konjević, Radomir; Steinitz, Benjamin; Poff, Kenneth L.

    1989-01-01

    In the phototropic response of Arabidopsis thaliana seedlings, the shape of the fluence-response relation depends on fluence rate and wavelength. At low fluence rates, the response to 450-nm light is characterized by a single maximum at about 0.3 μmol·m-2. At higher fluence rates, the response shows two distinct maxima, I and II, at 0.3 and 3.5 μmol·m-2, respectively. The response to 500-nm light shows a single maximum at 2 μmol·m-2, and the response to 510-nm light shows a single maximum at 4.5 μmol·m-2, independent of fluence rate. The response to 490-nm light shows a maximal at 4.5 μmol·m-2 and a shoulder at about 0.6 μmol·m-2. Preirradiation with high-fluence 510-nm light from above, immediately followed by unilateral 450-nm light, eliminates maximum II but not maximum I. Preirradiation with high-fluence 450-nm light from above eliminates the response to subsequent unilateral irradiation with either 450-nm or 510-nm light. The recovery of the response following high-fluence 450-nm light is considerably slower than the recovery following high-fluence 510-nm light. Unilateral irradiation with low-fluence 510-nm light followed by 450-nm light results in curvature that is approximately the sum of those produced by either irradiation alone. Based on these results, it is proposed that phototropism in A. thaliana seedlings is mediated by at least two blue-light photoreceptor pigments. PMID:16594094

  14. Effect of hemorrhage rate on early hemodynamic responses in conscious sheep.

    PubMed

    Scully, Christopher G; Daluwatte, Chathuri; Marques, Nicole R; Khan, Muzna; Salter, Michael; Wolf, Jordan; Nelson, Christina; Salsbury, John; Enkhbaatar, Perenlei; Kinsky, Michael; Kramer, George C; Strauss, David G

    2016-04-01

    Physiological compensatory mechanisms can mask the extent of hemorrhage in conscious mammals, which can be further complicated by individual tolerance and variations in hemorrhage onset and duration. We assessed the effect of hemorrhage rate on tolerance and early physiologic responses to hemorrhage in conscious sheep. Eight Merino ewes (37.4 ± 1.1 kg) were subjected to fast (1.25 mL/kg/min) and slow (0.25 mL/kg/min) hemorrhages separated by at least 3 days. Blood was withdrawn until a drop in mean arterial pressure (MAP) of >30 mmHg and returned at the end of the experiment. Continuous monitoring includedMAP, central venous pressure, pulmonary artery pressure, pulse oximetry, and tissue oximetry. Cardiac output by thermodilution and arterial blood samples were also measured. The effects of fast versus slow hemorrhage rates were compared for total volume of blood removed and stoppage time (whenMAP < 30 mmHg of baseline) and physiological responses during and after the hemorrhage. Estimated blood volume removed whenMAPdropped 30 mmHg was 27.0 ± 4.2% (mean ± standard error) in the slow and 27.3 ± 3.2% in the fast hemorrhage (P = 0.47, pairedttest between rates). Pressure and tissue oximetry responses were similar between hemorrhage rates. Heart rate increased at earlier levels of blood loss during the fast hemorrhage, but hemorrhage rate was not a significant factor for individual hemorrhage tolerance or hemodynamic responses. In 5/16 hemorrhages MAP stopping criteria was reached with <25% of blood volume removed. This study presents the physiological responses leading up to a significant drop in blood pressure in a large conscious animal model and how they are altered by the rate of hemorrhage. PMID:27044850

  15. Computational Simulation of the High Strain Rate Tensile Response of Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.

    2002-01-01

    A research program is underway to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to high strain rate impact loads. Under these types of loading conditions, the material response can be highly strain rate dependent and nonlinear. State variable constitutive equations based on a viscoplasticity approach have been developed to model the deformation of the polymer matrix. The constitutive equations are then combined with a mechanics of materials based micromechanics model which utilizes fiber substructuring to predict the effective mechanical and thermal response of the composite. To verify the analytical model, tensile stress-strain curves are predicted for a representative composite over strain rates ranging from around 1 x 10(exp -5)/sec to approximately 400/sec. The analytical predictions compare favorably to experimentally obtained values both qualitatively and quantitatively. Effective elastic and thermal constants are predicted for another composite, and compared to finite element results.

  16. Effects of age, signal level, and signal rate on the auditory middle latency response.

    PubMed

    Tucker, D A; Ruth, R A

    1996-04-01

    The effects of age, signal rate, and signal level on the maturing auditory middle latency response (AMLR) were evaluated in 50 normal-hearing subjects ranging in age from 2 days to 35 years. Ipsilateral and contralateral AMLR waveforms were recorded in newborns (n = 10), children (n = 10), preteens (n = 10), teens (n = 10), and adults (n = 10). The AMLR Pa waveform was obtained in 70 to 100 percent of all subjects. The variables of age, signal level, and site of recording significantly affected Pa peak amplitude and absolute latency. However, stimulus rate did not significantly affect the response.

  17. Effects of age, signal level, and signal rate on the auditory middle latency response.

    PubMed

    Tucker, D A; Ruth, R A

    1996-04-01

    The effects of age, signal rate, and signal level on the maturing auditory middle latency response (AMLR) were evaluated in 50 normal-hearing subjects ranging in age from 2 days to 35 years. Ipsilateral and contralateral AMLR waveforms were recorded in newborns (n = 10), children (n = 10), preteens (n = 10), teens (n = 10), and adults (n = 10). The AMLR Pa waveform was obtained in 70 to 100 percent of all subjects. The variables of age, signal level, and site of recording significantly affected Pa peak amplitude and absolute latency. However, stimulus rate did not significantly affect the response. PMID:8652873

  18. Extinction under a behavioral microscope: isolating the sources of decline in operant response rate.

    PubMed

    Cheung, Timothy H C; Neisewander, Janet L; Sanabria, Federico

    2012-05-01

    Extinction performance is often used to assess underlying psychological processes without the interference of reinforcement. For example, in the extinction/reinstatement paradigm, motivation to seek drug is assessed by measuring responding elicited by drug-associated cues without drug reinforcement. However, extinction performance is governed by several psychological processes that involve motivation, memory, learning, and motoric functions. These processes are confounded when overall response rate is used to measure performance. Based on evidence that operant responding occurs in bouts, this paper proposes an analytic procedure that separates extinction performance into several behavioral components: (1-3) the baseline bout initiation rate, within-bout response rate, and bout length at the onset of extinction; (4-6) their rates of decay during extinction; (7) the time between extinction onset and the decline of responding; (8) the asymptotic response rate at the end of extinction; (9) the refractory period after each response. Data that illustrate the goodness of fit of this analytic model are presented. This paper also describes procedures to isolate behavioral components contributing to extinction performance and make inferences about experimental effects on these components. This microscopic behavioral analysis allows the mapping of different psychological processes to distinct behavioral components implicated in extinction performance, which may further our understanding of the psychological effects of neurobiological treatments. PMID:22425782

  19. Extinction under a behavioral microscope: isolating the sources of decline in operant response rate.

    PubMed

    Cheung, Timothy H C; Neisewander, Janet L; Sanabria, Federico

    2012-05-01

    Extinction performance is often used to assess underlying psychological processes without the interference of reinforcement. For example, in the extinction/reinstatement paradigm, motivation to seek drug is assessed by measuring responding elicited by drug-associated cues without drug reinforcement. However, extinction performance is governed by several psychological processes that involve motivation, memory, learning, and motoric functions. These processes are confounded when overall response rate is used to measure performance. Based on evidence that operant responding occurs in bouts, this paper proposes an analytic procedure that separates extinction performance into several behavioral components: (1-3) the baseline bout initiation rate, within-bout response rate, and bout length at the onset of extinction; (4-6) their rates of decay during extinction; (7) the time between extinction onset and the decline of responding; (8) the asymptotic response rate at the end of extinction; (9) the refractory period after each response. Data that illustrate the goodness of fit of this analytic model are presented. This paper also describes procedures to isolate behavioral components contributing to extinction performance and make inferences about experimental effects on these components. This microscopic behavioral analysis allows the mapping of different psychological processes to distinct behavioral components implicated in extinction performance, which may further our understanding of the psychological effects of neurobiological treatments.

  20. The high-strain-rate and spallation response of tantalum, Ta-10W, and T-111

    SciTech Connect

    Gray, G.T. III; Rollett, A.D.

    1991-01-01

    The compressive true stress-true response of tantalum, Ta-10W, and T-111 were found to depend on the applied strain rate, in the range 0.001 to 7000 s{sup {minus}1}. The strain-rate sensitivities of the flow stress of tantalum, Ta-10W, and T-111 a 1% strain are 0.062, 0.031, and 0.024, respectively. The rates of strain hardening in Tantalum, Ta-10W, and T-111 are seen to exhibit differing behavior with increasing strain rate. The calculated average strain-hardening rate in tantalum, {Theta}, for the quasi-static (0.001 s{sup {minus}1}) data at 25{degrees}C is 2080 MPa/unit strain. The hardening rate at 3000s{sup {minus}1} at 25{degrees}C decreases to 846 MPa/unit strain. Normalizing the work hardening rate in tantalum with the Taylor Factor for a random polycrystal, ({Theta} / (3.07){sup 2}), yields work hardening rates of {mu}/276 at quasi-static strain rates and {mu}/680 at high-rates, assuming a shear modulus of 61 GPa for tantalum at room temperature. While the work hardening of all the tantalum-based materials are similar at quasi-static rates, alloying results in a small reduction in hardening rate. With increasing strain rate, the work hardening rate in tantalum decreases by approximately a factor of two compared to the alloys. Alloying tantalum with substitutional or interstitial elements is thought to result in increased edge dislocation storage and screw dislocation cross-slip due to interactions with the alloying elements at high strain rates. 28 refs.

  1. Response of thoracolumbar vertebral bodies to high rate compressive loading - biomed 2013.

    PubMed

    Dooley, C J; Wester, B A; Wing, I D; Voo, L M; Armiger, R S; Merkle, A C

    2013-01-01

    Underbody blast (UBB) events created by improvised explosive devices are threats to warfighter survivability. High intensity blast waves emitted from these devices transfer large forces through vehicle structures to occupants, often resulting in injuries including debilitating spinal fractures. The vertical loading vector through the spine generates significant compressive forces at high strain rates. To better understand injury mechanisms and ultimately better protect vehicle occupants against UBB attacks, high-fidelity computational models are being developed to predict the human response to dynamic loading characteristic of these events. This effort details the results from a series of 23 high-rate compression tests on vertebral body specimen. A high-rate servo-hydraulic test system applied a range of compressive loading rates (.01 mm/s to 1238 mm/s) to vertebral bodies in the thoracolumbar region (T7-L5). The force-deflection curves generated indicate rate dependent sensitivity of vertebral stiffness, ultimate load and ultimate deflection. Specimen subjected to high-rate dynamic loading to failure experienced critical structural damage at 5.5% ± 2.1% deflection. Compared to quasi-static loading, vertebral bodies had greater stiffness, greater force to failure, and lower ultimate failure deflection at high rates. Post-failure, an average loss in height of 15% was observed, along with a mean reduction in strength of 48%. The resulting data from these tests will allow for enhanced biofidelity of computational models by characterizing the vertebral stiffness response and ultimate deflection at rates representative of UBB events.

  2. In Situ Rates of Sulfate Reduction in Response to Geochemical Perturbations

    USGS Publications Warehouse

    Kneeshaw, T.A.; McGuire, J.T.; Cozzarelli, I.M.; Smith, E.W.

    2011-01-01

    Rates of in situ microbial sulfate reduction in response to geochemical perturbations were determined using Native Organism Geochemical Experimentation Enclosures (NOGEEs), a new in situ technique developed to facilitate evaluation of controls on microbial reaction rates. NOGEEs function by first trapping a native microbial community in situ and then subjecting it to geochemical perturbations through the introduction of various test solutions. On three occasions, NOGEEs were used at the Norman Landfill research site in Norman, Oklahoma, to evaluate sulfate-reduction rates in wetland sediments impacted by landfill leachate. The initial experiment, in May 2007, consisted of five introductions of a sulfate test solution over 11 d. Each test stimulated sulfate reduction with rates increasing until an apparent maximum was achieved. Two subsequent experiments, conducted in October 2007 and February 2008, evaluated the effects of concentration on sulfate-reduction rates. Results from these experiments showed that faster sulfate-reduction rates were associated with increased sulfate concentrations. Understanding variability in sulfate-reduction rates in response to perturbations may be an important factor in predicting rates of natural attenuation and bioremediation of contaminants in systems not at biogeochemical equilibrium. Copyright ?? 2011 The Author(s). Journal compilation ?? 2011 National Ground Water Association.

  3. Treatment Acceptability of Behavioral Interventions for Children: An Assessment by Mothers of Children with Disruptive Behavior Disorders.

    ERIC Educational Resources Information Center

    Jones, Melanie L.; Eyberg, Sheila M.; Adams, Christina D.; Boggs, Stephen R.

    1998-01-01

    Study assesses the acceptability of six child-management interventions as rated by mothers (N=20) of children referred for treatment for a disruptive-behavior disorder. Positive reinforcement was rated as a more acceptable treatment than response time, time-out, differential attention, overcorrection, and spanking. Results validate findings of…

  4. Usage and Dose Response of a Mobile Acceptance and Commitment Therapy App: Secondary Analysis of the Intervention Arm of a Randomized Controlled Trial

    PubMed Central

    Lappalainen, Raimo; Välkkynen, Pasi; Sairanen, Essi; Lappalainen, Päivi; Karhunen, Leila; Peuhkuri, Katri; Korpela, Riitta; Kolehmainen, Marjukka; Ermes, Miikka

    2016-01-01

    Background Mobile phone apps offer a promising medium to deliver psychological interventions. A mobile app based on Acceptance and Commitment Therapy (ACT) was developed and studied in a randomized controlled trial (RCT). Objective To study usage metrics of a mobile ACT intervention and dose-response relationship between usage and improvement in psychological flexibility. Methods An RCT was conducted to investigate the effectiveness of different lifestyle interventions for overweight people with psychological stress. This paper presents a secondary analysis of the group that received an 8-week mobile ACT intervention. Most of the analyzed 74 participants were female (n=64, 86%). Their median age was 49.6 (interquartile range, IQR 45.4-55.3) years and their mean level of psychological flexibility, measured with the Acceptance and Action Questionnaire II, was 20.4 (95% confidence interval 18.3-22.5). Several usage metrics describing the intensity of use, usage of content, and ways of use were calculated. Linear regression analyses were performed to study the dose-response relationship between usage and the change in psychological flexibility and to identify the usage metrics with strongest association with improvement. Binary logistic regression analyses were further used to assess the role of usage metrics between those who showed improvement in psychological flexibility and those who did not. In addition, associations between usage and baseline participant characteristics were studied. Results The median number of usage sessions was 21 (IQR 11.8-35), the number of usage days was 15 (IQR 9.0-24), and the number of usage weeks was 7.0 (IQR 4.0-8.0). The participants used the mobile app for a median duration of 4.7 (IQR 3.2-7.2) hours and performed a median of 63 (IQR 46-98) exercises. There was a dose-response relationship between usage and the change in psychological flexibility. The strongest associations with psychological flexibility (results adjusted with gender

  5. Evaluation of Neural Response Telemetry (NRT™) with focus on long-term rate adaptation over a wide range of stimulation rates.

    PubMed

    Huarte, Alicia; Ramos, Angel; Morera, Constantino; Garcia-Ibáñez, Luis; Battmer, Rolf; Dillier, Norbert; Wesarg, Thomas; Müller-Deile, Joachim; Hey, Mattias; Offeciers, Erwin; von Wallenberg, Ernst; Coudert, Chrystelle; Killian, Matthijs

    2014-05-01

    Custom Sound EP™ (CSEP) is an advanced flexible software tool dedicated to recording of electrically evoked compound action potentials (ECAPs) in Nucleus® recipients using Neural Response Telemetry™ (NRT™). European multi-centre studies of the Freedom™ cochlear implant system confirmed that CSEP offers tools to effectively record ECAP thresholds, amplitude growth functions, recovery functions, spread of excitation functions, and rate adaptation functions and an automated algorithm (AutoNRT™) to measure threshold profiles. This paper reports on rate adaptation measurements. Rate adaptation of ECAP amplitudes can successfully be measured up to rates of 495 pulses per second (pps) by repeating conventional ECAP measurements and over a wide range of rates up to 8000 pps using the masked response extraction technique. Rate adaptation did not show a predictable relationship with speech perception and coding strategy channel rate preference. The masked response extraction method offers opportunities to study long-term rate adaptation with well-defined and controlled stimulation paradigms. PMID:24559068

  6. [Base-rate estimates for negative response bias in a workers' compensation claim sample].

    PubMed

    Merten, T; Krahi, G; Krahl, C; Freytag, H W

    2010-09-01

    Against the background of a growing interest in symptom validity assessment in European countries, new data on base rates of negative response bias is presented. A retrospective data analysis of forensic psychological evaluations was performed based on 398 patients with workers' compensation claims. 48 percent of all patients scored below cut-off in at least one symptom validity test (SVT) indicating possible negative response bias. However, different SVTs appear to have differing potential to identify negative response bias. The data point at the necessity to use modern methods to check data validity in civil forensic contexts.

  7. Anger responses to psychosocial stress predict heart rate and cortisol stress responses in men but not women

    PubMed Central

    Lupis, Sarah B.; Lerman, Michelle; Wolf, Jutta M.

    2014-01-01

    While previous research has suggested that anger and fear responses to stress are linked to distinct sympathetic nervous system (SNS) stress responses, little is known about how these emotions predict hypothalamus-pituitary-adrenal (HPA) axis reactivity. Further, earlier research primarily relied on retrospective self-report of emotion. The current study aimed at addressing both issues in male and female individuals by assessing the role of anger and fear in predicting heart rate and cortisol stress responses using both self-report and facial coding analysis to assess emotion responses. We exposed 32 healthy students (18 female; 19.6+/−1.7 yrs.) to an acute psychosocial stress paradigm (TSST) and measured heart rate and salivary cortisol levels throughout the protocol. Anger and fear before and after stress exposure was assessed by self-report, and video recordings of the TSST were assessed by a certified facial coder to determine emotion expression (FACS). Self-reported emotions and emotion expressions did not correlate (all p > .23). Increases in self-reported fear predicted blunted cortisol responses in men (β = 0.41, p = .04). Also for men, longer durations of anger expression predicted exaggerated cortisol responses (β = 0.67 p = .004), and more anger incidences predicted exaggerated cortisol and heart rate responses (β = 0.51, p = .033; β = 0.46, p = .066, resp.). Anger and fear did not predict SNS or HPA activity for females (all p > .23). The current differential self-report and facial coding findings support the use of multiple modes of emotion assessment. Particularly, FACS but not self-report revealed a robust anger-stress association that could have important downstream health effects for men. For women, future research may clarify the role of other emotions, such as self-conscious expressions of shame, for physiological stress responses. A better understanding of the emotion-stress link may contribute to behavioral interventions targeting health

  8. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    USGS Publications Warehouse

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  9. Focus on Response Rate Is Important but Not Sufficient: A Reply

    ERIC Educational Resources Information Center

    Chase, Philip N.; Doughty, Shannon S.; O'Shields, Elizabethann

    2005-01-01

    This article presents a reply to the response made by Carl Binder that was critical of the authors' review of rate-building procedures. For the most part, the authors were disappointed in Binder's reply because they believe it muddied the focus of their review: an examination of the "experimental" evidence for the procedures used and suggested by…

  10. Extra Credit Micro-Incentives and Response Rates for Online Course Evaluations: Two Quasi-Experiments

    ERIC Educational Resources Information Center

    Sundstrom, Eric D.; Hardin, Erin E.; Shaffer, Matthew J.

    2016-01-01

    To extend prior findings on the motivational value of tiny, nonfinancial incentives, we conducted two quasi-experiments on the relationship of extra credit micro-incentives (ECMIs, worth =1% of course grade) and response rates for online course evaluations. Study 1 involved two advanced undergraduate psychology courses taught by the same…

  11. Effects of an Introductory Letter on Response Rates to a Teen/Parent Telephone Health Survey

    ERIC Educational Resources Information Center

    Woodruff, Susan I.; Mayer, Joni A.; Clapp, Elizabeth

    2006-01-01

    The authors conducted a pilot study in preparation for a larger investigation that will rely on telephone surveys to assess select health behaviors of teens and their parents, with a focus on indoor tanning. This study used a randomized design to assess the impact of a presurvey letter on response rates to a telephone survey, as well as prevalence…

  12. Survey Platform: A Factor Influencing Online Survey Delivery and Response Rate

    ERIC Educational Resources Information Center

    Nair, Chenicheri Sid; Adams, Phillip

    2009-01-01

    Online surveys in general are advantageous because of the ease of administration, collection and storing of data resulting in monetary and time savings. Though research in general shows the advantages to be beneficial, the down-side to such online surveys has been the response rate. The aim of this paper is to initiate a discussion where one…

  13. Effects of Varying Response Formats on Self-Ratings of Life-Satisfaction

    ERIC Educational Resources Information Center

    Mazaheri, Mehrdad; Theuns, Peter

    2009-01-01

    A sample of 1,737 volunteering students, randomly assigned to 12 conditions, rated their current overall (dis)satisfaction with life. Each condition used 1 of 12 response formats, differing in (1) "polarity" ("bipolar" versus "unipolar"), (2) "orientation" ("horizontal" versus "vertical"), and (3) "anchoring" (-5 to +5, "Not Numbered," and 0 "to"…

  14. Articulatory-to-Acoustic Relations in Response to Speaking Rate and Loudness Manipulations

    ERIC Educational Resources Information Center

    Mefferd, Antje S.; Green, Jordan R.

    2010-01-01

    Purpose: In this investigation, the authors determined the strength of association between tongue kinematic and speech acoustics changes in response to speaking rate and loudness manipulations. Performance changes in the kinematic and acoustic domains were measured using two aspects of speech production presumably affecting speech clarity:…

  15. Avoidance of Timeout from Response-Independent Food: Effects of Delivery Rate and Quality

    ERIC Educational Resources Information Center

    Richardson, Joseph V.; Baron, Alan

    2008-01-01

    In three experiments, a rat's lever presses could postpone timeouts from food pellets delivered on response-independent schedules. In Experiment 1, the pellets were delivered at variable-time (VT) rates ranging from VT 0.5 to VT 8 min. Experiment 2 replicated the VT 1 min and VT 8 min conditions of Experiment 1 with new subjects. Finally, subjects…

  16. Response and Remission in Adolescent Mania: Signal Detection Analyses of the Young Mania Rating Scale

    ERIC Educational Resources Information Center

    Patel, Nick C.; Patrick, Danielle M.; Youngstrom, Eric A.; Strakowski, Stephen M.; Delbello, Melissa P.

    2007-01-01

    Objective: The purpose of this study was to determine optimal criteria for defining response and remission in adolescents with acute mania. Method: Data were analyzed from three treatment studies of adolescents with acute mania (N = 99). Trained raters completed the Young Mania Rating Scale (YMRS), and clinicians completed the Clinical Global…

  17. Two Approaches to Estimation of Classification Accuracy Rate under Item Response Theory

    ERIC Educational Resources Information Center

    Lathrop, Quinn N.; Cheng, Ying

    2013-01-01

    Within the framework of item response theory (IRT), there are two recent lines of work on the estimation of classification accuracy (CA) rate. One approach estimates CA when decisions are made based on total sum scores, the other based on latent trait estimates. The former is referred to as the Lee approach, and the latter, the Rudner approach,…

  18. Effects of Frustration on the Response Rate of Skid Row Alcoholics on a Performance Task

    ERIC Educational Resources Information Center

    Scorzelli, James F.; Reinke-Scorzelli, Mary

    1976-01-01

    Determines the changes that may occur in the response rates of 14 skid row alcoholics on a performance task after the introduction of a frustration operation. Results suggest a possible relationship between low frustration tolerance and the method by which these individuals tend to motivate themselves. (Author)

  19. The Effect of a College Pen Incentive on Survey Response Rate among Recent College Graduates

    ERIC Educational Resources Information Center

    Stange, Jonathan P.; Zyzanski, Stephen J.

    2011-01-01

    Incentives have shown a variable effect in improving survey response rates, but the effect of a pen from an organization to which the respondent has loyalty has not been studied. Recent college graduates were randomized to receive or not receive a college logo pen accompanying an initial survey mailing. Among 119 total respondents, there were no…

  20. Response-Time Variability Is Related to Parent Ratings of Inattention, Hyperactivity, and Executive Function

    ERIC Educational Resources Information Center

    Gomez-Guerrero, Lorena; Martin, Cristina Dominguez; Mairena, Maria Angeles; Di Martino, Adriana; Wang, Jing; Mendelsohn, Alan L.; Dreyer, Benard P.; Isquith, Peter K.; Gioia, Gerard; Petkova, Eva; Castellanos, F. Xavier

    2011-01-01

    Objective: Individuals with ADHD are often characterized as inconsistent across many contexts. ADHD is also associated with deficits in executive function. We examined the relationships between response time (RT) variability on five brief computer tasks to parents' ratings of ADHD-related features and executive function in a group of children with…

  1. Effect of Booklet/Folder Questionnaire Format and Style of Type on Mail Survey Response Rates.

    ERIC Educational Resources Information Center

    Boser, Judith A.

    Results of two studies, involving surveys of alumni of postsecondary institutions, are presented to assess the effect of format and typeface on mail survey response rates. The first study focused on the effect of booklet/folder format versus stapled sheets. The method of reproduction, page content, page size, and appearance of the questionnaires…

  2. Slew-rate dependence of tracer magnetization response in magnetic particle imaging

    PubMed Central

    Shah, Saqlain A.; Ferguson, R. M.

    2014-01-01

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ0 excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (Ho) and frequency (ω). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ0. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (ωHo) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories. PMID:25422528

  3. Slew-rate dependence of tracer magnetization response in magnetic particle imaging.

    PubMed

    Shah, Saqlain A; Ferguson, R M; Krishnan, K M

    2014-10-28

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ0 excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (Ho ) and frequency (ω). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ0. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (ωH o) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories. PMID:25422528

  4. Smaller, faster stomata: scaling of stomatal size, rate of response, and stomatal conductance

    PubMed Central

    Franks, Peter J.

    2013-01-01

    Maximum and minimum stomatal conductance, as well as stomatal size and rate of response, are known to vary widely across plant species, but the functional relationship between these static and dynamic stomatal properties is unknown. The objective of this study was to test three hypotheses: (i) operating stomatal conductance under standard conditions (g op) correlates with minimum stomatal conductance prior to morning light [g min(dawn)]; (ii) stomatal size (S) is negatively correlated with g op and the maximum rate of stomatal opening in response to light, (dg/dt)max; and (iii) g op correlates negatively with instantaneous water-use efficiency (WUE) despite positive correlations with maximum rate of carboxylation (Vc max) and light-saturated rate of electron transport (J max). Using five closely related species of the genus Banksia, the above variables were measured, and it was found that all three hypotheses were supported by the results. Overall, this indicates that leaves built for higher rates of gas exchange have smaller stomata and faster dynamic characteristics. With the aid of a stomatal control model, it is demonstrated that higher g op can potentially expose plants to larger tissue water potential gradients, and that faster stomatal response times can help offset this risk. PMID:23264516

  5. Frequency sweep rate dependence on the dielectrophoretic response of polystyrene beads and red blood cells

    PubMed Central

    Adams, T. N. G.; Leonard, K. M.; Minerick, A. R.

    2013-01-01

    Alternating current (AC) dielectrophoresis (DEP) experiments for biological particles in microdevices are typically done at a fixed frequency. Reconstructing the DEP response curve from static frequency experiments is laborious, but essential to ascertain differences in dielectric properties of biological particles. Our lab explored the concept of sweeping the frequency as a function of time to rapidly determine the DEP response curve from fewer experiments. For the purpose of determining an ideal sweep rate, homogeneous 6.08 μm polystyrene (PS) beads were used as a model system. Translatability of the sweep rate approach to ∼7 μm red blood cells (RBC) was then verified. An Au/Ti quadrapole electrode microfluidic device was used to separately subject particles and cells to 10Vpp AC electric fields at frequencies ranging from 0.010 to 2.0 MHz over sweep rates from 0.00080 to 0.17 MHz/s. PS beads exhibited negative DEP assembly over the frequencies explored due to Maxwell-Wagner interfacial polarizations. Results demonstrate that frequency sweep rates must be slower than particle polarization timescales to achieve reliable incremental polarizations; sweep rates near 0.00080 MHz/s yielded DEP behaviors very consistent with static frequency DEP responses for both PS beads and RBCs. PMID:24396548

  6. Mechanical response of porcine skin under compression from low to high strain rates

    NASA Astrophysics Data System (ADS)

    Bo, Chiara; Butler, Ben; Williams, Alun; Brown, Katherine; Proud, William

    2013-06-01

    Uniaxial compression experiments were performed on fresh porcine skin samples at different strain rates to study the stress-strain response. Low strain rate experiments were performed with an Instron 5566, while high strain rates were achieved using a Split Hopkinson Pressure Bar system. Magnesium bars and semiconductor strain gauges were used respectively to maximize the signal transmission from porcine skin to the output bar and to allow the signal measurement. Skin samples were harvested from different area of the animal to investigate the heterogeneity of such material. The experimental results showed that the mechanical response of skin in compression is strongly dependent on the strain rate of loading and on the location from which the samples were collected. Specimens collected from the rump showed a stiffer response compared to samples harvested from the thigh. Finally, a histological analysis of the samples post compression was carried out to examine the extent of tissue damage as a function of strain rate. This work is supported by the Atomic Weapons Establishment, UK and The Royal British Legion Centre for Blast Injury Studies at Imperial College London, UK.

  7. Neuronal response impedance mechanism implementing cooperative networks with low firing rates and μs precision.

    PubMed

    Vardi, Roni; Goldental, Amir; Marmari, Hagar; Brama, Haya; Stern, Edward A; Sardi, Shira; Sabo, Pinhas; Kanter, Ido

    2015-01-01

    Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory links, while feasibility of temporal coding is limited by neuronal millisecond precision. We show that cooperation, governing global network features, emerges through nodal properties, as opposed to link distributions. Using in vitro and in vivo experiments we demonstrate microsecond precision of neuronal response timings under low stimulation frequencies, whereas moderate frequencies result in a chaotic neuronal phase characterized by degraded precision. Above a critical stimulation frequency, which varies among neurons, response failures were found to emerge stochastically such that the neuron functions as a low pass filter, saturating the average inter-spike-interval. This intrinsic neuronal response impedance mechanism leads to cooperation on a network level, such that firing rates are suppressed toward the lowest neuronal critical frequency simultaneously with neuronal microsecond precision. Our findings open up opportunities of controlling global features of network dynamics through few nodes with extreme properties.

  8. Neuronal response impedance mechanism implementing cooperative networks with low firing rates and μs precision

    PubMed Central

    Vardi, Roni; Goldental, Amir; Marmari, Hagar; Brama, Haya; Stern, Edward A.; Sardi, Shira; Sabo, Pinhas; Kanter, Ido

    2015-01-01

    Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory links, while feasibility of temporal coding is limited by neuronal millisecond precision. We show that cooperation, governing global network features, emerges through nodal properties, as opposed to link distributions. Using in vitro and in vivo experiments we demonstrate microsecond precision of neuronal response timings under low stimulation frequencies, whereas moderate frequencies result in a chaotic neuronal phase characterized by degraded precision. Above a critical stimulation frequency, which varies among neurons, response failures were found to emerge stochastically such that the neuron functions as a low pass filter, saturating the average inter-spike-interval. This intrinsic neuronal response impedance mechanism leads to cooperation on a network level, such that firing rates are suppressed toward the lowest neuronal critical frequency simultaneously with neuronal microsecond precision. Our findings open up opportunities of controlling global features of network dynamics through few nodes with extreme properties. PMID:26124707

  9. Functional traits explain light and size response of growth rates in tropical tree species.

    PubMed

    Rüger, Nadja; Wirth, Christian; Wright, S Joseph; Condit, Richard

    2012-12-01

    Relationships between functional traits and average or potential demographic rates have provided insight into the functional constraints and trade-offs underlying life-history strategies of tropical tree species. We have extended this framework by decomposing growth rates of -130 000 trees of 171 Neotropical tree species into intrinsic growth and the response of growth to light and size. We related these growth characteristics to multiple functional traits (wood density, adult stature, seed mass, leaf traits) in a hierarchical Bayesian model that accounted for measurement error and intraspecific variability of functional traits. Wood density was the most important trait determining all three growth characteristics. Intrinsic growth rates were additionally strongly related to adult stature, while all traits contributed to light response. Our analysis yielded a predictive model that allows estimation of growth characteristics for rare species on the basis of a few easily measurable morphological traits.

  10. California Federal Facilities: Rate-Responsive Building Operation for Deeper Cost and Energy Savings

    SciTech Connect

    2012-05-01

    Dynamic pricing electricity tariffs, now the default for large customers in California (peak demand of 200 kW and higher for PG&E and SCE, and 20 kW and higher for SDG&E), are providing Federal facilities new opportunities to cut their electricity bills and help them meet their energy savings mandates. The U.S. Department of Energy’s (DOE) Federal Energy Management Program (FEMP) has created this fact sheet to help California federal facilities take advantage of these opportunities through “rate-responsive building operation.” Rate-responsive building operation involves designing your load management strategies around your facility’s variable electric rate, using measures that require little or no financial investment.

  11. Effectiveness of an on-body lifting aid at reducing low back physical demands during an automotive assembly task: assessment of EMG response and user acceptability.

    PubMed

    Graham, Ryan B; Agnew, Michael J; Stevenson, Joan M

    2009-09-01

    The purpose of this study was to investigate the effectiveness and user acceptability of a Personal Lift-Assist Device (PLAD) at an automotive manufacturing facility, with operators who perform an on-line assembly process requiring forward bending and static holding. Surface EMG data were collected at six sites on the low back and abdomen, and an accelerometer was used to measure trunk inclination. Use of the PLAD significantly reduced the thoracic and lumbar erector spinae activity and EMG-predicted compression at the 10th, 50th, and 90th APDF percentile levels (p < or = 0.05), without significantly increasing rectus abdominus activity or trunk flexion. Similarly, ratings of perceived exertion were found to be significantly lower when wearing the PLAD (p = 0.006). Subjective opinions were positive, with 8/10 subjects indicating they would wear the device everyday. With slight changes, workers felt that the PLAD could be beneficial at reducing forces and discomfort in similar industrial or manual materials handling tasks that place excessive physical demands on the low back.

  12. Effect of different river flow rates on biomarker responses in common carp (Cyprinus carpio).

    PubMed

    Hackenberger, Branimir K; Velki, Mirna; Lončarić, Zeljka; Hackenberger, Davorka K; Ečimović, Sandra

    2015-02-01

    The present study investigated effects of different river flow rates on basal activities of selected biomarkers and the occurrence of oxidative stress in the common carp (Cyprinus carpio). Juvenile carp were exposed to different river flow rates (5-120 cm/s) by caging for 3 weeks. After this period, one half of the fish were sacrificed and used for analysis. The other half received a single intraperitoneal injection of 3-methylcholanthrene (3-MC) and after 6 days were sacrificed and used for analysis. In order to investigate whether the physical activity of carp in the environment will influence the condition status of carp, following biomarkers were measured - activities of glutathione S-transferase (GST), catalase (CAT) and ethoxyresorufin-O-deethylase (EROD) and concentration of protein carbonyls (PC). The results showed that different flow rates significantly influenced biochemical biomarkers. The basal activity of GST did not change significantly after exposure to different river flow rates, whereas the activity of CAT increased with increasing river flow rates. The application of 3-MC caused significant increases in GST and CAT activities, but there were no difference between 3-MC control and 3-MC different flow rates. The occurrence of oxidative stress as a result of exposure to increased physical activity, i.e. increased river flow rates, was confirmed by measurement of PC levels - the level of PC increased with increasing river flow rates. Measurement of EROD basal activity showed that at lower river flow rates the EROD activity increased and at higher river flow rates decreased towards control levels demonstrating a close relationship between oxidative stress, PC levels and EROD activity. Obviously, biomarker responses in carp of different condition status can differ substantially. It can be concluded that flow rate may be an important factor in biomonitoring of rivers using biomarkers and since at different locations river water flow rate can vary

  13. Cortisol release, heart rate and heart rate variability in the horse and its rider: different responses to training and performance.

    PubMed

    von Lewinski, Mareike; Biau, Sophie; Erber, Regina; Ille, Natascha; Aurich, Jörg; Faure, Jean-Michel; Möstl, Erich; Aurich, Christine

    2013-08-01

    Although some information exists on the stress response of horses in equestrian sports, the horse-rider team is much less well understood. In this study, salivary cortisol concentrations, heart rate (HR) and heart rate variability (HRV), SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) were analysed in horses and their riders (n=6 each) at a public performance and an identical rehearsal that was not open to the public. Cortisol concentrations increased in both horses and riders (P<0.001) but did not differ between performance and rehearsal. HR in horses and riders increased during the rehearsal and the public performance (P<0.001) but the increase in HR was more pronounced (P<0.01) in riders than in their horses during the public performance (from 91 ± 10 to 150 ± 15 beats/min) compared to the rehearsal (from 94 ± 10 to 118 ± 12 beats/min). The SDRR decreased significantly during the equestrian tasks in riders (P<0.001), but not in their horses. The RMSSD decreased in horses and riders (P<0.001) during rehearsal and performance, indicating a decrease in parasympathetic tone. The decrease in RMSSD in the riders was more pronounced (P<0.05) during the performance (from 32.6 ± 6.6 to 3.8 ± 0.3 ms) than during the rehearsal (from 27.5 ± 4.2 to 6.6 ± 0.6 ms). The study has shown that the presence of spectators caused more pronounced changes in cardiac activity in the riders than it did in their horses.

  14. High rate response of ultra-high-performance fiber-reinforced concretes under direct tension

    SciTech Connect

    Tran, Ngoc Thanh; Tran, Tuan Kiet; Kim, Dong Joo

    2015-03-15

    The tensile response of ultra-high-performance fiber-reinforced concretes (UHPFRCs) at high strain rates (5–24 s{sup −} {sup 1}) was investigated. Three types of steel fibers, including twisted, long and short smooth steel fibers, were added by 1.5% volume content in an ultra high performance concrete (UHPC) with a compressive strength of 180 MPa. Two different cross sections, 25 × 25 and 25 × 50 mm{sup 2}, of tensile specimens were used to investigate the effect of the cross section area on the measured tensile response of UHPFRCs. Although all the three fibers generated strain hardening behavior even at high strain rates, long smooth fibers produced the highest tensile resistance at high rates whereas twisted fiber did at static rate. The breakages of twisted fibers were observed from the specimens tested at high strain rates unlike smooth steel fibers. The tensile behavior of UHPFRCs at high strain rates was clearly influenced by the specimen size, especially in post-cracking strength.

  15. Changes of firing rate induced by changes of phase response curve in bifurcation transitions.

    PubMed

    Sato, Yasuomi D; Aihara, Kazuyuki

    2014-11-01

    We study dynamical mechanisms responsible for changes of the firing rate during four different bifurcation transitions in the two-dimensional Hindmarsh-Rose (2DHR) neuron model: the saddle node on an invariant circle (SNIC) bifurcation to the supercritical Andronov-Hopf (AH) one, the SNIC bifurcation to the saddle-separatrix loop (SSL) one, the AH bifurcation to the subcritical AH (SAH) one, and the SSL bifurcation to the AH one. For this purpose, we study slopes of the firing rate curve with respect to not only an external input current but also temperature that can be interpreted as a timescale in the 2DHR neuron model. These slopes are mathematically formulated with phase response curves (PRCs), expanding the firing rate with perturbations of the temperature and external input current on the one-dimensional space of the phase [Formula: see text] in the 2DHR oscillator. By analyzing the two different slopes of the firing rate curve with respect to the temperature and external input current, we find that during changes of the firing rate in all of the bifurcation transitions, the calculated slope with respect to the temperature also changes. This is largely dependent on changes in the PRC size that is also related to the slope with respect to the external input current. Furthermore, we find phase transition-like switches of the firing rate with a possible increase of the temperature during the SSL-to-AH bifurcation transition.

  16. The modified gait abnormality rating scale in patients with a conversion disorder: a reliability and responsiveness study.

    PubMed

    Vandenberg, Justin M; George, Deanna R; O'Leary, Andrea J; Olson, Lindsay C; Strassburg, Kaitlyn R; Hollman, John H

    2015-01-01

    Individuals with conversion disorder have neurologic symptoms that are not identified by an underlying organic cause. Often the symptoms manifest as gait disturbances. The modified gait abnormality rating scale (GARS-M) may be useful for quantifying gait abnormalities in these individuals. The purpose of this study was to examine the reliability, responsiveness and concurrent validity of GARS-M scores in individuals with conversion disorder. Data from 27 individuals who completed a rehabilitation program were included in this study. Pre- and post-intervention videos were obtained and walking speed was measured. Five examiners independently evaluated gait performance according to the GARS-M criteria. Inter- and intrarater reliability of GARS-M scores were estimated with intraclass correlation coefficients (ICCs). Responsiveness was estimated with the minimum detectable change (MDC). Pre- to post-treatment changes in GARS-M scores were analyzed with a dependent t-test. The correlation between GARS-M scores and walking speed was analyzed to assess concurrent validity. GARS-M scores were quantified with good-to-excellent inter- (ICC = 0.878) and intrarater reliability (ICC = 0.989). The MDC was 2 points. Mean GARS-M scores decreased from 7 ± 5 at baseline to 1 ± 2 at discharge (t26 = 7.411, p < 0.001) and 85% of patients improved beyond the MDC. Furthermore, GARS-M scores and walking speed measurements were moderately correlated (r = -0.582, p = 0.004), indicating that the GARS-M has acceptable concurrent validity. Our findings provide evidence that the GARS-M scores are reliable, valid and responsive for quantifying gait abnormalities in patients with conversion disorder. GARS-M scores provide objective measures upon which treatment effects can be assessed.

  17. Time-variant modelling of heart rate responses to exercise intensity during road cycling.

    PubMed

    Lefever, Joris; Berckmans, Daniel; Aerts, Jean-Marie

    2014-01-01

    The aim of this study was to determine if heart rate responses to training intensity during road cycling could be modelled with compact time-variant mathematical model structures. The model performance was evaluated in terms of model order (complexity), number of inputs and parameter estimation methods used (time-invariant vs. time-variant). Thirteen male cyclists performed two identical cycling tests of 27 km on the road. Uphill sections were introduced to induce dynamic variations in heart rate. The heart rate and training intensity, represented by power output and road inclination, were measured in real-time. Taking only power as system input allowed to explain the variations in heart rate in an accurate way R2 T = 0.86 ± 0.08, since adding the road inclination as an additional input did not significantly improve the modelling performance R2 T = 0.87 ± 0.08, P = 0.32. Furthermore, we demonstrated that models with first-order dynamics accurately describes the heart rate responses to power variations R2 T = 0.86 ± 0.08, but that more complex second-order model structures R2 T = 0.88 ± 0.08 were significantly better than the first-order model structures (P = 0.028). Finally, the heart rate dynamics appeared to be time-variant, since the time-variant model structures R2 T = 0.89 ± 0.07 were significantly better than the time-invariant model structures R2 T = 0.84 ± 0.08, P = 0.0002. So, compact time-variant second-order model structures could be used to model the heart rate response to training intensity as a basis for training optimisation.

  18. Do Ethical Judgments Depend on the Type of Response Scale? Comparing Acceptability versus Unacceptability Judgments in the Case of Life-Ending Procedures

    ERIC Educational Resources Information Center

    Sastre, Maria Teresa Munoz; Gonzalez, Charlene; Lhermitte, Astrid; Sorum, Paul C.; Mullet, Etienne

    2010-01-01

    Using Functional Measurement (Anderson, 2008), Frileux, Lelievre, Munoz Sastre, Mullet, and Sorum (2003) examined the joint impact of several key factors on lay people's judgments of the acceptability of physicians' interventions to end patients' lives. The level of acceptability was high, and the information integration rule that best described…

  19. Chemotherapy for Late-Stage Cancer Patients: Meta-Analysis of Complete Response Rates

    PubMed Central

    Ashdown, Martin L.; Robinson, Andrew P.; Yatomi-Clarke, Steven L.; Ashdown, M. Luisa; Allison, Andrew; Abbott, Derek; Markovic, Svetomir N.; Coventry, Brendon J.

    2015-01-01

    Complete response (CR) rates reported for cytotoxic chemotherapy for late-stage cancer patients are generally low, with few exceptions, regardless of the solid cancer type or drug regimen. We investigated CR rates reported in the literature for clinical trials using chemotherapy alone, across a wide range of tumour types and chemotherapeutic regimens, to determine an overall CR rate for late-stage cancers. A total of 141 reports were located using the PubMed database. A meta-analysis was performed of reported CR from 68 chemotherapy trials (total 2732 patients) using standard agents across late-stage solid cancers—a binomial model with random effects was adopted. Mean CR rates were compared for different cancer types, and for chemotherapeutic agents with different mechanisms of action, using a logistic regression. Our results showed that the CR rates for chemotherapy treatment of late-stage cancer were generally low at 7.4%, regardless of the cancer type or drug regimen used. We found no evidence that CR rates differed between different chemotherapy drug types, but amongst different cancer types small CR differences were evident, although none exceeded a mean CR rate of 11%. This remarkable concordance of CR rates regardless of cancer or therapy type remains currently unexplained, and motivates further investigation. PMID:26834979

  20. Effects of a Follow-On Formula Containing Isomaltulose (Palatinose™) on Metabolic Response, Acceptance, Tolerance and Safety in Infants: A Randomized-Controlled Trial

    PubMed Central

    Fleddermann, M.; Rauh-Pfeiffer, A.; Demmelmair, H.; Holdt, L.; Teupser, D.; Koletzko, B.

    2016-01-01

    Effects of the dietary glycaemic load on postprandial blood glucose and insulin response might be of importance for fat deposition and risk of obesity. We aimed to investigate the metabolic effects, acceptance and tolerance of a follow-on formula containing the low glycaemic and low insulinaemic carbohydrate isomaltulose replacing high glycaemic maltodextrin. Healthy term infants aged 4 to 8 completed months (n = 50) were randomized to receive the intervention follow-on formula (IF, 2.1g isomaltulose (Palatinose™)/100mL) or an isocaloric conventional formula (CF) providing 2.1g maltodextrin/100mL for four weeks. Plasma insulinaemia 60min after start of feeding (primary outcome) was not statistically different, while glycaemia adjusted for age and time for drinking/volume of meal 60min after start of feeding was 122(105,140) mg/dL in IF (median, interquartile range) and 111(100,123) in CF (p = 0.01). Urinary c-peptide:creatinine ratio did not differ (IF:81.5(44.7, 96.0) vs. CF:56.8(37.5, 129),p = 0.43). Urinary c-peptide:creatinine ratio was correlated total intake of energy (R = 0.31,p = 0.045), protein (R = 0.42,p = 0.006) and fat (R = 0.40,p = 0.01) but not with carbohydrate intake (R = 0.22,p = 0.16). Both formulae were well accepted without differences in time of crying, flatulence, stool characteristics and the occurrence of adverse events. The expected lower postprandial plasma insulin and blood glucose level due to replacement of high glycaemic maltodextrin by low glycaemic isomaltulose were not observed in the single time-point blood analysis. In infants aged 4 to 8 completed months fed a liquid formula, peak blood glucose might be reached earlier than 60min after start of feeding. Non-invasive urinary c-peptide measurements may be a suitable marker of nutritional intake during the previous four days in infants. Trial registration: ClinicalTrials.gov NCT01627015 PMID:26987056

  1. Baby-Crying Acceptance

    NASA Astrophysics Data System (ADS)

    Martins, Tiago; de Magalhães, Sérgio Tenreiro

    The baby's crying is his most important mean of communication. The crying monitoring performed by devices that have been developed doesn't ensure the complete safety of the child. It is necessary to join, to these technological resources, means of communicating the results to the responsible, which would involve the digital processing of information available from crying. The survey carried out, enabled to understand the level of adoption, in the continental territory of Portugal, of a technology that will be able to do such a digital processing. It was used the TAM as the theoretical referential. The statistical analysis showed that there is a good probability of acceptance of such a system.

  2. Pregnancy Risk Assessment Monitoring System in Ireland: methods and response rates.

    PubMed

    O'Keeffe, Linda M; Kearney, Patricia M; Greene, Richard A

    2015-03-01

    To describe response rates and characteristics associated with response to the Pregnancy Risk Assessment Monitoring System study in Ireland (PRAMS Ireland). Using hospital discharge records of live births at a large, urban, obstetric hospital, a sampling frame of approximately 2,400 mother-infant pairs were used to alternately sample 1,200 women. Mothers' information including name, address, parity, age and infant characteristics such as sex and gestational age at delivery were extracted from records. Modes of contact included an invitation letter with option to opt out of the study, three mail surveys, a reminder letter and text message reminder for remaining non-respondents. Sixty-one per cent of women responded to the PRAMS Ireland survey over a 133 day response period. Women aged <30, single women, multiparous women and women with a preterm delivery were less likely to respond. Women participating in PRAMS Ireland were similar to the national birth profile in 2011 which had a mean age of 32, were 40 % primiparous, 33 % single or never married and had a 28 % caesarean section rate. Survey and protocol changes are required to increase response rates above recommended Centers for Disease Control and Prevention (CDC) thresholds of 65 % within the recommended 90 day data collection cycle. Additional efforts such as stratification and over-sampling are required to increase representativeness among hard to reach groups such as younger, single and multiparous women before expanding the project to an ongoing, national surveillance system in Ireland. PMID:24912944

  3. The high strain rate compressive response of Mg-Al alloy/fly Ash cenosphere composites

    NASA Astrophysics Data System (ADS)

    Luong, Dung D.; Gupta, Nikhil; Rohatgi, Pradeep K.

    2011-02-01

    The strain rate dependence of mechanical properties of AZ91D alloy composites filled with 5 wt.% hollow fly ash cenosphere is examined in the strain rate range of 630-1,203 s-1 using a split-Hopkinson pressure bar system. In addition, a test scheme is designed to study the intermediate strain rate response of the material. Addition of fly ash caused grain refinement and finer precipitates in the matrix alloy. Compared to the matrix alloy, the energy absorption is higher in AZ91D/fly ash cenosphere composites at comparable strain rates. In addition, the yield strength is found to be about 19-41% higher in the composites containing fly ash cenospheres.

  4. The responses of I beta cells to increases in the rate of lung inflation.

    PubMed

    Marino, P L; Davies, R O; Pack, A I

    1981-08-31

    The activity of inspiratory cells in the region of the nucleus of the tractus solitarius (NTS) was recorded extracellularly in paralyzed, artificially ventilated cats either during chloralose-urethane anesthesia or following midcollicular decerebration. Twenty-three of the 68 inspiratory cells recorded in the region of the NTS were classified as I beta cells on the basis of their response to withholding lung inflation. The dynamic sensitivity of I beta cells was determined by studying their response to increases in the rate of lung inflation at constant peak volume. The I beta cells in this study showed 3 distinct patterns of response to increases in the rate of inflation. Five cells showed no change in firing pattern (fixed firing pattern). Ten cells showed an increase in the rate of rise of cell activity but no change in peak frequency (low dynamic sensitivity). Eight cells showed increases in both the rate of rise of cell activity and peak frequency (high dynamic sensitivity). It was concluded that I beta cells are not a functionally homogeneous population, at least in terms of their dynamic sensitivity. Cells showing fixed firing patterns have the characteristics of off-switch neurons. Cells with low levels of dynamic sensitivity may receive afferents from pulmonary stretch receptors. Cells showing a high degree of dynamic sensitivity may receive afferents from rapidly adapting receptors. The fact that I beta cells are not a functionally homogeneous population may explain the many divergent observations reported from studies of these cells.

  5. Evaluation of simulated photolysis rates and their response to solar irradiance variability

    NASA Astrophysics Data System (ADS)

    Sukhodolov, Timofei; Rozanov, Eugene; Ball, William T.; Bais, Alkiviadis; Tourpali, Kleareti; Shapiro, Alexander I.; Telford, Paul; Smyshlyaev, Sergey; Fomin, Boris; Sander, Rolf; Bossay, Sébastien; Bekki, Slimane; Marchand, Marion; Chipperfield, Martyn P.; Dhomse, Sandip; Haigh, Joanna D.; Peter, Thomas; Schmutz, Werner

    2016-05-01

    The state of the stratospheric ozone layer and the temperature structure of the atmosphere are largely controlled by the solar spectral irradiance (SSI) through its influence on heating and photolysis rates. This study focuses on the uncertainties in the photolysis rate response to solar irradiance variability related to the choice of SSI data set and to the performance of the photolysis codes used in global chemistry-climate models. To estimate the impact of SSI uncertainties, we compared several photolysis rates calculated with the radiative transfer model libRadtran, using SSI calculated with two models and observed during the Solar Radiation and Climate Experiment (SORCE) satellite mission. The importance of the calculated differences in the photolysis rate response for ozone and temperature changes has been estimated using 1-D a radiative-convective-photochemical model. We demonstrate that the main photolysis reactions, responsible for the solar signal in the stratosphere, are highly sensitive to the spectral distribution of SSI variations. Accordingly, the ozone changes and related ozone-temperature feedback are shown to depend substantially on the SSI data set being used, which highlights the necessity of obtaining accurate SSI variations. To evaluate the performance of photolysis codes, we compared the results of eight, widely used, photolysis codes against two reference schemes. We show that, in most cases, absolute values of the photolysis rates and their response to applied SSI changes agree within 30%. However, larger errors may appear in specific atmospheric regions because of differences, for instance, in the treatment of Rayleigh scattering, quantum yields, or absorption cross sections.

  6. Higher Crash and Near-Crash Rates in Teenaged Drivers With Lower Cortisol Response

    PubMed Central

    Ouimet, Marie Claude; Brown, Thomas G.; Guo, Feng; Klauer, Sheila G.; Simons-Morton, Bruce G.; Fang, Youjia; Lee, Suzanne E.; Gianoulakis, Christina; Dingus, Thomas A.

    2014-01-01

    IMPORTANCE Road traffic crashes are one of the leading causes of injury and death among teenagers worldwide. Better understanding of the individual pathways to driving risk may lead to better-targeted intervention in this vulnerable group. OBJECTIVE To examine the relationship between cortisol, a neurobiological marker of stress regulation linked to risky behavior, and driving risk. DESIGN, SETTING, AND PARTICIPANTS The Naturalistic Teenage Driving Study was designed to continuously monitor the driving behavior of teenagers by instrumenting vehicles with kinematic sensors, cameras, and a global positioning system. During 2006–2008, a community sample of 42 newly licensed 16-year-old volunteer participants in the United States was recruited and driving behavior monitored. It was hypothesized in teenagers that higher cortisol response to stress is associated with (1) lower crash and near-crash (CNC) rates during their first 18 months of licensure and (2) faster reduction in CNC rates over time. MAIN OUTCOMES AND MEASURES Participants’ cortisol response during a stress-inducing task was assessed at baseline, followed by measurement of their involvement in CNCs and driving exposure during their first 18 months of licensure. Mixed-effect Poisson longitudinal regression models were used to examine the association between baseline cortisol response and CNC rates during the follow-up period. RESULTS Participants with a higher baseline cortisol response had lower CNC rates during the follow-up period (exponential of the regression coefficient, 0.93; 95%CI, 0.88–0.98) and faster decrease in CNC rates over time (exponential of the regression coefficient, 0.98; 95%, CI, 0.96–0.99). CONCLUSIONS AND RELEVANCE Cortisol is a neurobiological marker associated with teenaged-driving risk. As in other problem-behavior fields, identification of an objective marker of teenaged-driving risk promises the development of more personalized intervention approaches. PMID:24710522

  7. Response of thoracolumbar vertebral bodies to high rate compressive loading - biomed 2013.

    PubMed

    Dooley, C J; Wester, B A; Wing, I D; Voo, L M; Armiger, R S; Merkle, A C

    2013-01-01

    Underbody blast (UBB) events created by improvised explosive devices are threats to warfighter survivability. High intensity blast waves emitted from these devices transfer large forces through vehicle structures to occupants, often resulting in injuries including debilitating spinal fractures. The vertical loading vector through the spine generates significant compressive forces at high strain rates. To better understand injury mechanisms and ultimately better protect vehicle occupants against UBB attacks, high-fidelity computational models are being developed to predict the human response to dynamic loading characteristic of these events. This effort details the results from a series of 23 high-rate compression tests on vertebral body specimen. A high-rate servo-hydraulic test system applied a range of compressive loading rates (.01 mm/s to 1238 mm/s) to vertebral bodies in the thoracolumbar region (T7-L5). The force-deflection curves generated indicate rate dependent sensitivity of vertebral stiffness, ultimate load and ultimate deflection. Specimen subjected to high-rate dynamic loading to failure experienced critical structural damage at 5.5% ± 2.1% deflection. Compared to quasi-static loading, vertebral bodies had greater stiffness, greater force to failure, and lower ultimate failure deflection at high rates. Post-failure, an average loss in height of 15% was observed, along with a mean reduction in strength of 48%. The resulting data from these tests will allow for enhanced biofidelity of computational models by characterizing the vertebral stiffness response and ultimate deflection at rates representative of UBB events. PMID:23686197

  8. Pretreatment Growth Rate Predicts Radiation Response in Vestibular Schwannomas

    SciTech Connect

    Niu, Nina N.; Niemierko, Andrzej; Larvie, Mykol; Curtin, Hugh; Loeffler, Jay S.; McKenna, Michael J.; Shih, Helen A.

    2014-05-01

    Purpose: Vestibular schwannomas (VS) are often followed without initial therapeutic intervention because many tumors do not grow and radiation therapy is associated with potential adverse effects. In an effort to determine whether maximizing initial surveillance predicts for later treatment response, the predictive value of preirradiation growth rate of VS on response to radiation therapy was assessed. Methods and Materials: Sixty-four patients with 65 VS were treated with single-fraction stereotactic radiation surgery or fractionated stereotactic radiation therapy. Pre- and postirradiation linear expansion rates were estimated using volumetric measurements on sequential magnetic resonance images (MRIs). In addition, postirradiation tumor volume change was classified as demonstrating shrinkage (ratio of volume on last follow-up MRI to MRI immediately preceding irradiation <80%), stability (ratio 80%-120%), or expansion (ratio >120%). The median pre- and postirradiation follow-up was 20.0 and 27.5 months, respectively. Seven tumors from neurofibromatosis type 2 (NF2) patients were excluded from statistical analyses. Results: In the 58 non-NF2 patients, there was a trend of correlation between pre- and postirradiation volume change rates (slope on linear regression, 0.29; P=.06). Tumors demonstrating postirradiation expansion had a median preirradiation growth rate of 89%/year, and those without postirradiation expansion had a median preirradiation growth rate of 41%/year (P=.02). As the preirradiation growth rate increased, the probability of postirradiation expansion also increased. Overall, 24.1% of tumors were stable, 53.4% experienced shrinkage, and 22.5% experienced expansion. Predictors of no postirradiation tumor expansion included no prior surgery (P=.01) and slower tumor growth rate (P=.02). The control of tumors in NF2 patients was only 43%. Conclusions: Radiation therapy is an effective treatment for VS, but tumors that grow quickly preirradiation may be

  9. Regional differences in sweat rate response of steers to short-term heat stress

    NASA Astrophysics Data System (ADS)

    Scharf, B.; Wax, L. E.; Aiken, G. E.; Spiers, D. E.

    2008-11-01

    Six Angus steers (319 ± 8.5 kg) were assigned to one of two groups (hot or cold exposure) of three steers each, and placed into two environmental chambers initially maintained at 16.5-18.8°C air temperature ( T a). Cold chamber T a was lowered to 8.4°C, while T a within the hot chamber was increased to 32.7°C over a 24-h time period. Measurements included respiration rate, and air and body (rectal and skin) temperatures. Skin temperature was measured at shoulder and rump locations, with determination of sweat rate using a calibrated moisture sensor. Rectal temperature did not change in cold or hot chambers. However, respiration rate nearly doubled in the heat ( P < 0.05), increasing when T a was above 24°C. Skin temperatures at the two locations were highly correlated ( P < 0.05) with each other and with T a. In contrast, sweat rate showed differences at rump and shoulder sites. Sweat rate of the rump exhibited only a small increase with T a. However, sweat rate at the shoulder increased more than four-fold with increasing T a. Increased sweat rate in this region is supported by an earlier report of a higher density of sweat glands in the shoulder compared to rump regions. Sweat rate was correlated with several thermal measurements to determine the best predictor. Fourth-order polynomial expressions of short-term rectal and skin temperature responses to hot and cold exposures produced r values of 0.60, 0.84, and 0.98, respectively. These results suggest that thermal inputs other than just rectal or skin temperature drive the sweat response in cattle.

  10. Blood pressure response to heart rate during exercise test and risk of future hypertension.

    PubMed

    Miyai, Nobuyuki; Arita, Mikio; Miyashita, Kazuhisa; Morioka, Ikuharu; Shiraishi, Tatsuo; Nishio, Ichiro

    2002-03-01

    Previous works have shown that exaggerated blood pressure response to exercise is a valid risk marker for future hypertension, yet the use of an exercise test as a means of early prediction of hypertension still requires methodological development and confirmation. The purpose of this study was to determine abnormal ranges of blood pressure responses in relation to heart rate increase during exercise and to examine the clinical utility of exercise blood pressure measurement in evaluating individual risk for developing hypertension. We examined exercise test data from a population-based sample of 1033 nonmedicated normotensive men (mean age, 42.9+/-8.5 years; range, 20 to 59 years). Percentile curves of systolic and diastolic blood pressure responses to relative heart rate increments during submaximal exercise were constructed using a third-order polynomial model with multiple regression analysis. Of the original study sample, a cohort of 726 subjects was followed for hypertensive outcome for an average period of 4.7 years. Progression to hypertension, defined as a blood pressure of > or =140/90 mm Hg or the initiation of antihypertensive therapy, was found in 114 subjects (15.4%). Kaplan-Meier survival estimates showed that the cumulative incidence of hypertension increased progressively with higher percentiles of systolic and diastolic blood pressure response (both, P<0.01). A Cox proportional survival analysis revealed a significantly increased risk for developing hypertension associated with exaggerated blood pressure response to exercise after multivariable adjustments for traditional risk factors (relative risk, 3.8; 95% confidence interval, 2.3 to 6.1). These results suggest that an exaggerated blood pressure response to heart rate during exercise is predictive of future hypertension independent of other important risk factors and lend further support to the concept that blood pressure measurement during exercise test is a valuable means of identifying

  11. Heart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorder.

    PubMed

    Ehlers, Anke; Suendermann, Oliver; Boellinghaus, Inga; Vossbeck-Elsebusch, Anna; Gamer, Matthias; Briddon, Emma; Martin, Melanie Walwyn; Glucksman, Edward

    2010-10-01

    Physiological responses to trauma reminders are one of the core symptoms of posttraumatic stress disorder (PTSD). Nevertheless, screening measures for PTSD largely rely on symptom self-reports. It has been suggested that psychophysiological assessments may be useful in identifying trauma survivors with PTSD (Orr and Roth, 2000). This study investigated whether heart rate (HR) responses to standardized trauma-related pictures distinguish between trauma survivors with and without acute PTSD. Survivors of motor vehicle accidents or physical assaults (N=162) watched standardized trauma-related, generally threatening and neutral pictures at 1 month post-trauma while their ECG was recorded. At 1 and 6 months, structured clinical interviews assessed PTSD diagnoses. Participants completed self-report measures of PTSD severity and depression, peritraumatic responses, coping behaviors and appraisals. Trauma survivors with acute PTSD showed greater HR responses to trauma-related pictures than those without PTSD, as indicated by a less pronounced mean deceleration, greater peak responses, and a greater proportion showing HR acceleration of greater than 1 beat per minute. There were no group differences in HR responses to generally threatening or neutral pictures. HR responses to trauma-related pictures contributed to the prediction of PTSD diagnosis over and above what could be predicted from self-reports of PTSD and depression. HR responses to trauma-related pictures were related to fear and data-driven processing during the trauma, safety behaviors, suppression of trauma memories, and overgeneralized appraisals of danger. The results suggest that HR responses to standardized trauma-related pictures may help identify a subgroup of patients with acute PTSD who show generalized fear responses to trauma reminders. The early generalization of triggers of reexperiencing symptoms observed in this study is consistent with associative learning and cognitive models of PTSD.

  12. Heart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorder

    PubMed Central

    Ehlers, Anke; Suendermann, Oliver; Boellinghaus, Inga; Vossbeck-Elsebusch, Anna; Gamer, Matthias; Briddon, Emma; Martin, Melanie Walwyn; Glucksman, Edward

    2010-01-01

    Physiological responses to trauma reminders are one of the core symptoms of posttraumatic stress disorder (PTSD). Nevertheless, screening measures for PTSD largely rely on symptom self-reports. It has been suggested that psychophysiological assessments may be useful in identifying trauma survivors with PTSD (Orr and Roth, 2000). This study investigated whether heart rate (HR) responses to standardized trauma-related pictures distinguish between trauma survivors with and without acute PTSD. Survivors of motor vehicle accidents or physical assaults (N = 162) watched standardized trauma-related, generally threatening and neutral pictures at 1 month post-trauma while their ECG was recorded. At 1 and 6 months, structured clinical interviews assessed PTSD diagnoses. Participants completed self-report measures of PTSD severity and depression, peritraumatic responses, coping behaviors and appraisals. Trauma survivors with acute PTSD showed greater HR responses to trauma-related pictures than those without PTSD, as indicated by a less pronounced mean deceleration, greater peak responses, and a greater proportion showing HR acceleration of greater than 1 beat per minute. There were no group differences in HR responses to generally threatening or neutral pictures. HR responses to trauma-related pictures contributed to the prediction of PTSD diagnosis over and above what could be predicted from self-reports of PTSD and depression. HR responses to trauma-related pictures were related to fear and data-driven processing during the trauma, safety behaviors, suppression of trauma memories, and overgeneralized appraisals of danger. The results suggest that HR responses to standardized trauma-related pictures may help identify a subgroup of patients with acute PTSD who show generalized fear responses to trauma reminders. The early generalization of triggers of reexperiencing symptoms observed in this study is consistent with associative learning and cognitive models of PTSD. PMID

  13. An exploration of heart rate response to differing music rhythm and tempos.

    PubMed

    da Silva, Ariany G; Guida, Heraldo L; Antônio, Ana Márcia Dos S; Marcomini, Renata S; Fontes, Anne M G G; Carlos de Abreu, Luiz; Roque, Adriano L; Silva, Sidney B; Raimundo, Rodrigo D; Ferreira, Celso; Valenti, Vitor E

    2014-05-01

    The aim of this study was to investigate acute cardiac response and heart rate variability (HRV) when listening to differing forms of music. Eleven healthy men aged between 18 and 25 years old were included in the study. HRV was recorded at rest for ten minutes with no music, then were asked to listen to classical baroque or heavy metal music for a period of 20 min. It was noted that heart rate variability did not affect HRV indices for time and frequency. In conclusion, music with different tempos does not influence cardiac autonomic regulation in men. However more studies are suggested to explore this topic in greater detail. PMID:24767959

  14. An exploration of heart rate response to differing music rhythm and tempos.

    PubMed

    da Silva, Ariany G; Guida, Heraldo L; Antônio, Ana Márcia Dos S; Marcomini, Renata S; Fontes, Anne M G G; Carlos de Abreu, Luiz; Roque, Adriano L; Silva, Sidney B; Raimundo, Rodrigo D; Ferreira, Celso; Valenti, Vitor E

    2014-05-01

    The aim of this study was to investigate acute cardiac response and heart rate variability (HRV) when listening to differing forms of music. Eleven healthy men aged between 18 and 25 years old were included in the study. HRV was recorded at rest for ten minutes with no music, then were asked to listen to classical baroque or heavy metal music for a period of 20 min. It was noted that heart rate variability did not affect HRV indices for time and frequency. In conclusion, music with different tempos does not influence cardiac autonomic regulation in men. However more studies are suggested to explore this topic in greater detail.

  15. Response rate in the Study of Cardiovascular Risks in Adolescents – ERICA

    PubMed Central

    da Silva, Thiago Luiz Nogueira; Klein, Carlos Henrique; Souza, Amanda de Moura; Barufaldi, Laura Augusta; Abreu, Gabriela de Azevedo; Kuschnir, Maria Cristina Caetano; de Vasconcellos, Mauricio Teixeira Leite; Bloch, Katia Vergetti

    2016-01-01

    ABSTRACT OBJECTIVE To describe the response rate and characteristics of people who either took part or not in from the Study of Cardiovascular Risks in Adolescents (ERICA) , according to information subsets. METHODS ERICA is a school-based, nation-wide investigation with a representative sample of 12 to 17-year-old adolescents attending public or private schools in municipalities with over 100,000 inhabitants in Brazil. Response rate of eligible subjects were calculated according to macro-regions, sex, age, and type of school (public or private). We also calculated the percentages of replacement schools in comparison with the ones originally selected as per the sample design, according to the types of schools in the macro-regions. The subjects and non-subjects were compared according to sex, age, and average body mass indices (kg/m2). RESULTS We had 102,327 eligible adolescents enrolled in the groups drawn. The highest percentage of complete information was obtained for the subset of the questionnaire (72.9%). Complete information regarding anthropometric measurements and the ones from the questionnaire were obtained for 72.0% of the adolescents, and the combination of these data with the 24-hour dietary recall were obtained for 70.3% of the adolescents. Complete information from the questionnaire plus biochemical blood evaluation data were obtained for 52.5% of the morning session adolescents (selected for blood tests). The response percentage in private schools was higher than the one in public schools for most of the combination of information. The ratio of older and male adolescents non-participants was higher than the ratio among participants. CONCLUSIONS The response rate for non-invasive procedures was high. The response rate for blood collection – an invasive procedure that requires a 12-hour fasting period and the informed consent form from legal guardians – was lower. The response rate observed in public schools was lower than in the private ones, and

  16. Heritability of submaximal exercise heart rate response to exercise training is accounted for by nine SNPs.

    PubMed

    Rankinen, Tuomo; Sung, Yun Ju; Sarzynski, Mark A; Rice, Treva K; Rao, D C; Bouchard, Claude

    2012-03-01

    Endurance training-induced changes in hemodynamic traits are heritable. However, few genes associated with heart rate training responses have been identified. The purpose of our study was to perform a genome-wide association study to uncover DNA sequence variants associated with submaximal exercise heart rate training responses in the HERITAGE Family Study. Heart rate was measured during steady-state exercise at 50 W (HR50) on 2 separate days before and after a 20-wk endurance training program in 483 white subjects from 99 families. Illumina HumanCNV370-Quad v3.0 BeadChips were genotyped using the Illumina BeadStation 500GX platform. After quality control procedures, 320,000 single-nucleotide polymorphisms (SNPs) were available for the genome-wide association study analyses, which were performed using the MERLIN software package (single-SNP analyses and conditional heritability tests) and standard regression models (multivariate analyses). The strongest associations for HR50 training response adjusted for age, sex, body mass index, and baseline HR50 were detected with SNPs at the YWHAQ locus on chromosome 2p25 (P = 8.1 × 10(-7)), the RBPMS locus on chromosome 8p12 (P = 3.8 × 10(-6)), and the CREB1 locus on chromosome 2q34 (P = 1.6 × 10(-5)). In addition, 37 other SNPs showed P values <9.9 × 10(-5). After removal of redundant SNPs, the 10 most significant SNPs explained 35.9% of the ΔHR50 variance in a multivariate regression model. Conditional heritability tests showed that nine of these SNPs (all intragenic) accounted for 100% of the ΔHR50 heritability. Our results indicate that SNPs in nine genes related to cardiomyocyte and neuronal functions, as well as cardiac memory formation, fully account for the heritability of the submaximal heart rate training response.

  17. Neurohumoral mechanisms associated with orthostasis: reaffirmation of the significant contribution of the heart rate response

    PubMed Central

    Convertino, Victor A.

    2014-01-01

    The inability to compensate for acute central hypovolemia underlies the clinical development of orthostatic hypotension and instability (e.g., syncope). Although neuro-humoral control of both cardiac output and peripheral vascular resistance contributes to hemodynamic stability during orthostasis, a notion has been proposed that the failure of adequate peripheral vascular constriction rather than cardiac responses represents the primary mechanism underlying the development of orthostatic intolerance. This review article provides an opportunity to present compelling evidence captured over the past 30 years in our laboratory to support the concept that neural-mediated tachycardia during orthostasis in healthy individuals represents a critical response to tolerating acute reduction in central blood volume in addition to, and independent of, peripheral vascular constriction. In this review paper, data are presented from experiments using graded lower body negative pressure (LBNP) as a method to induce orthostatic intolerance in two experimental human models: (1) comparison of heart rate and autonomic responses in individuals with relatively high and low tolerance to LBNP; and (2) vagal and sympathetic blockade of cardiac neural control. These experiments revealed that: (1) greater elevations in heart rate are associated with higher orthostatic (LBNP) tolerance; (2) higher orthostatic heart rate is associated with greater sympathetic nerve activity and withdrawal of vagally-mediated cardiac baroreflex response; and (3) non-specific sympathetic blockade causes a pronounced reduction in heart rate and LBNP tolerance. Cardiac parasympathetic withdrawal contributes to protection against development of hypotension during the initial seconds of transition to an orthostatic challenge, while the primary mechanism by which tachycardia defends orthostatic stability in healthy subjects for extended durations is mediated predominantly through sympathetic adrenergic control. PMID

  18. Response Rates for Mixed-Mode Surveys Using Mail and E-Mail/Web

    ERIC Educational Resources Information Center

    Converse, Patrick D.; Wolfe, Edward W.; Huang, Xiaoting; Oswald, Frederick L.

    2008-01-01

    This study examines response rates for mixed-mode survey implementation involving mail and e-mail/Web components. Using Dillman's Tailored Design Method, 1,500 participants were sent a survey either (a) via mail with a follow-up contact via e-mail that directed them to a Web-based questionnaire or (b) via e-mail that directed them to a Web-based…

  19. Differential rate responses to nicotine in rat heart: evidence for two classes of nicotinic receptors.

    PubMed

    Ji, Susan; Tosaka, Toshimasa; Whitfield, Bernard H; Katchman, Alexander N; Kandil, Abdurrahman; Knollmann, Bjoern C; Ebert, Steven N

    2002-06-01

    Nicotinic acetylcholine receptors are pentameric, typically being composed of two or more different subunits. To investigate which receptor subtypes are active in the heart, we initiated a series of experiments using an isolated perfused rat heart (Langendorff) preparation. Nicotine administration (100 microM) caused a brief decrease (-7 +/- 2%) followed by a much larger increase (17 +/- 5%) in heart rate that slowly returned to baseline within 10 to 15 min. The nicotine-induced decrease in heart rate could be abolished by an alpha7-specific antagonist, alpha-bungarotoxin (100 nM). In contrast, the nicotine-induced increase in heart rate persisted in the presence of alpha-bungarotoxin. These results suggest that the nicotinic acetylcholine receptors (nAChRs) that mediate the initial decrease in heart rate probably contain alpha7 subunits, whereas those that mediate the increase in heart rate probably do not contain alpha7 subunits. To investigate which subunits may contribute to the nicotine-induced increase in heart rate, we repeated our experiments with cytisine, an agonist at nAChRs that contain beta4 subunits. The cytisine results were similar to those obtained with nicotine, thereby suggesting that the nAChRs on sympathetic nerve terminals in the heart probably contain beta4 subunits. Thus, the results of this study show that pharmacologically distinct nAChRs are responsible for the differential effects of nicotine on heart rate. More specifically, our results suggest that alpha7 subunits participate in the initial nicotine-induced heart rate decrease, whereas beta4 subunits help to mediate the subsequent nicotine-induced rise in heart rate.

  20. Slew-rate dependence of tracer magnetization response in magnetic particle imaging

    SciTech Connect

    Shah, Saqlain A.; Krishnan, K. M.; Ferguson, R. M.

    2014-10-28

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ{sub 0} excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (H{sub o}) and frequency (ω). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ{sub 0}. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (ωH{sub o}) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories.

  1. Attachment Status Affects Heart Rate Responses to Experimental Ostracism in Inpatients with Depression

    PubMed Central

    De Rubeis, Jannika; Sütterlin, Stefan; Lange, Diane; Pawelzik, Markus; van Randenborgh, Annette; Victor, Daniela; Vögele, Claus

    2016-01-01

    Depression is assumed to be both a risk factor for rejection and a result of it, and as such constitutes an important factor in rejection research. Attachment theory has been applied to understand psychological disorders, such as depression, and can explain individual differences in responses to rejection. Research on autonomic nervous system activity to rejection experiences has been contradictory, with opposing strings of argumentation (activating vs. numbing). We investigated autonomic nervous system-mediated peripheral physiological responses (heart rate) to experimentally manipulated ostracism (Cyberball) in 97 depressed patients with organized (n = 52) and disorganized attachment status (n = 45). Controlling for baseline mean heart rate levels, depressed patients with disorganized attachment status responded to ostracism with significantly higher increases in heart rate than depressed patients with organized attachment status (p = .029; ηp2 = .051). These results suggest that attachment status may be a useful indicator of autonomic responses to perceived social threat, which in turn may affect the therapeutic process and the patient-therapist relationship. PMID:26943924

  2. Attachment Status Affects Heart Rate Responses to Experimental Ostracism in Inpatients with Depression.

    PubMed

    De Rubeis, Jannika; Sütterlin, Stefan; Lange, Diane; Pawelzik, Markus; van Randenborgh, Annette; Victor, Daniela; Vögele, Claus

    2016-01-01

    Depression is assumed to be both a risk factor for rejection and a result of it, and as such constitutes an important factor in rejection research. Attachment theory has been applied to understand psychological disorders, such as depression, and can explain individual differences in responses to rejection. Research on autonomic nervous system activity to rejection experiences has been contradictory, with opposing strings of argumentation (activating vs. numbing). We investigated autonomic nervous system-mediated peripheral physiological responses (heart rate) to experimentally manipulated ostracism (Cyberball) in 97 depressed patients with organized (n = 52) and disorganized attachment status (n = 45). Controlling for baseline mean heart rate levels, depressed patients with disorganized attachment status responded to ostracism with significantly higher increases in heart rate than depressed patients with organized attachment status (p = .029; ηp2 = .051). These results suggest that attachment status may be a useful indicator of autonomic responses to perceived social threat, which in turn may affect the therapeutic process and the patient-therapist relationship.

  3. The rate dependent response of a bistable chain at finite temperature

    NASA Astrophysics Data System (ADS)

    Benichou, Itamar; Zhang, Yaojun; Dudko, Olga K.; Givli, Sefi

    2016-10-01

    We study the rate dependent response of a bistable chain subjected to thermal fluctuations. The study is motivated by the fact that the behavior of this model system is prototypical to a wide range of nonlinear processes in materials physics, biology and chemistry. To account for the stochastic nature of the system response, we formulate a set of governing equations for the evolution of the probability density of meta-stable configurations. Based on this approach, we calculate the behavior for a wide range of parametric values, such as rate, temperature, overall stiffness, and number of elements in the chain. Our results suggest that fundamental characteristics of the response, such as average transition stress and hysteresis, can be captured by a simple law which folds the influence of all these factors into a single non-dimensional quantity. We also show that the applicability of analytical results previously obtained for single-well systems can be extended to systems having multiple wells by proper definition of rate and of the transition stress.

  4. College students' response rate to an incentivized combination of postal and web-based health survey.

    PubMed

    Balajti, Ilona; Daragó, László; Adány, Róza; Kósa, Karolina

    2010-06-01

    A questionnaire survey on health among students of higher education was planned. To produce a response rate high enough for the analysis in a cost-effective manner, a pilot study was carried out to test various methods of data collection. Electronic invitation by the university messaging system to fill a Web-based questionnaire, invitation by the same means to fill paper-based questionnaires at a predefined place and time with or without conditional incentives yielded response rates below 10%. Therefore, a combination of postal and Internet-based questionnaires was used for data collection enhanced with a small up-front gift and conditional incentives suggested by a student focus group. This modality resulted in a 68.6% response rate (65.2% after data cleaning). Those who responded through the Web were more likely to be males and residing in larger settlements. However, no statistically significant differences were observed on the primary health status variables with respect to modality. Use of Web-based questionnaires is recommended in combination with other data collection methods and incentives.

  5. Attachment Status Affects Heart Rate Responses to Experimental Ostracism in Inpatients with Depression.

    PubMed

    De Rubeis, Jannika; Sütterlin, Stefan; Lange, Diane; Pawelzik, Markus; van Randenborgh, Annette; Victor, Daniela; Vögele, Claus

    2016-01-01

    Depression is assumed to be both a risk factor for rejection and a result of it, and as such constitutes an important factor in rejection research. Attachment theory has been applied to understand psychological disorders, such as depression, and can explain individual differences in responses to rejection. Research on autonomic nervous system activity to rejection experiences has been contradictory, with opposing strings of argumentation (activating vs. numbing). We investigated autonomic nervous system-mediated peripheral physiological responses (heart rate) to experimentally manipulated ostracism (Cyberball) in 97 depressed patients with organized (n = 52) and disorganized attachment status (n = 45). Controlling for baseline mean heart rate levels, depressed patients with disorganized attachment status responded to ostracism with significantly higher increases in heart rate than depressed patients with organized attachment status (p = .029; ηp2 = .051). These results suggest that attachment status may be a useful indicator of autonomic responses to perceived social threat, which in turn may affect the therapeutic process and the patient-therapist relationship. PMID:26943924

  6. Nutmeg mannikins ( Lonchura punctulata) reduce their feeding rates in response to simulated competition.

    PubMed

    Gauvin, Shawn; Giraldeau, Luc-Alain

    2004-03-01

    Group feeding animals experience a number of competitive foraging costs that may result in a lowered feeding rate. It is important to distinguish between reductions in feeding rates that are caused by reduced food availability and physical interactions among foragers from those caused by the mere presence of foraging companions that may be self-imposed in order to obtain some benefit of group membership. Starlings ( Sturnus vulgaris) reduce their feeding rates when in the company of simulated competitors located in an adjacent cage that cannot affect the food availability or interact with the forager. In the present study, we investigate whether the presence of simulated competitors in another species of passerine, nutmeg mannikins ( Lonchura punctulata), can result in self-imposed reductions in feeding rates. When feeding in the company of simulated competitors, mannikins spent more non-foraging time near them, fed more slowly, reduced travel times between patches, reduced their scanning time and pecked more slowly. These results provide evidence that simulated competitors induce a reduction in pecking rate: behavioural interference. These self-imposed responses to competitors may have resulted from attempts to remain close to the non-feeding companions. Such self-imposed reductions in feeding rates may be a widespread yet generally unrecognised foraging cost to group feeding individuals.

  7. Changes in Pathological Complete Response Rates after Neoadjuvant Chemotherapy for Breast Carcinoma over Five Years

    PubMed Central

    McFarland, Daniel C.; Naikan, Jessica; Rozenblit, Mariya; Mandeli, John; Bleiweiss, Ira; Tiersten, Amy

    2016-01-01

    Historically, neoadjuvant chemotherapy (NACT) was extrapolated from adjuvant regimens. Dual HER2 blockade and the introduction of carboplatin for triple negative breast cancers (TNBC) emerged by December 2013 and have improved pathological complete response (pCR) rates. The objective of this study was to assess the pCR rates before and after the introduction of these new neoadjuvant regimens. Materials and Methods. Stage I–III breast cancer patients who received NACT were analyzed for rates of pCR by clinical characteristics (i.e., age, BMI, axillary lymphadenopathy, and histologic subtype), by time period (1 = 3/2010–11/2013, 2 = 12/2013–3/2015), and by type of chemotherapy (e.g., anthracycline/taxane only, carboplatin-containing, and HER2 blockade). Results. 113 patients received NACT. Overall pCR rate was 26.5 percent (n = 30). The pCR rate increased from 14% to 43.1% (p = 0.001) from time period 1 to time period 2 and were associated with HER2 positivity (p = 0.003), receiving treatment during time period 2 (p = 0.001) and using an anthracycline/taxane plus additional agent type of regimen (p = 0.004). Conclusions. Our study revealed a significant difference in rates of pCR over five years. Window of opportunity trials and other trials that utilize pCR analysis should be encouraged. PMID:27382369

  8. Response of Polypmeric Foams and ABS Plastics to High Strain Rate Loading

    NASA Astrophysics Data System (ADS)

    Dick, Richard; Chang, Peter; Fourney, William

    1999-06-01

    The split-Hopkinson pressure bar (SHPB) technique was utilized to obtain high strain rate response data for low-density foams and solid ABS and polypropylene plastics. General Motors provided the materials for this study. These materials are used in the interior panels of automobiles. Because the foams have a very low impedance, polycarbonate bars were used to acquire the strain rate data in the 100 to 1600 per second range. An aluminum SHPB was used to obtain the solid plastics data that covered strain rates of 1000 to 4000 pre second. The experimental data indicate that the foams over the test range are only slightly strain rate dependent while the polypropylene appears to be strain rate independent above 1000 per second and the ABS plastics are strain rate independent above 3000 per second. The projectile length was varied to provide a wide range of induced strains ranging from 10 to 70 per cent for the foams and up to 20 per cent for the plastic materials.

  9. Intrapericardial denervation - Radial artery blood flow and heart rate responses to LBNP

    NASA Technical Reports Server (NTRS)

    Mckeever, Kenneth H.; Skidmore, Michael G.; Keil, Lanny C.; Sandler, Harold

    1990-01-01

    The effects of intrapericardial denervation on the radial artery blood flow velocity (RABFV) and heart rate (HR) responses to LBNP in rhesus monkeys were investigated by measuring the RABFV transcutaneously by a continuous-wave Doppler ultrasonic flowmeter in order to derive an index of forearm blood flow response to low (0 to -20 mm Hg) and high (0 to -60 mm Hg) ramp exposures during supine LBNP. Four of the eight subjects were subjected to efferent and afferent cardiac denervation. It was found that, during low levels of LBNP, monkeys with cardiac denervation exhibited no cardiopulmonary baroreceptor-mediated change in the RABFV or HR, unlike the intact animals, which showed steady decreases in RABFV during both high- and low-pressure protocols. It is suggested that forearm blood flow and HR responses to low-level LBNP, along with pharmacological challenge, are viable physiological tests for verifying the completeness of atrial and cardiopulmonary baroreceptor denervation.

  10. Effects of aircraft motion on passengers' comfort ratings and response times.

    PubMed

    Rinalducci, E J

    1980-02-01

    Comfort ratings and response times for changes in the experienced level of comfort were examined in 20 subjects using the NASA Flight Research Center's Jetstar aircraft modified to carry the GPAS system (General Purpose Airborne Simulator). Data were obtained for each of the subjects during two runs of 10 1-min. flight segments. In general, as the magnitude of aircraft motion increased in either the vertical or transverse (lateral) directions, there was an increase in feelings of discomfort and a decrease in response times to those changes. These results suggest parallels between the large body of laboratory data on human reaction time and that collected in this field study on response times to changes in ride comfort.

  11. Heart rate response to fear conditioning and virtual reality in subthreshold PTSD.

    PubMed

    Roy, Michael J; Costanzo, Michelle E; Jovanovic, Tanja; Leaman, Suzanne; Taylor, Patricia; Norrholm, Seth D; Rizzo, Albert A

    2013-01-01

    Posttraumatic stress disorder (PTSD) is a significant health concern for U.S. military service members (SMs) returning from Afghanistan and Iraq. Early intervention to prevent chronic disability requires greater understanding of subthreshold PTSD symptoms, which are associated with impaired physical health, mental health, and risk for delayed onset PTSD. We report a comparison of physiologic responses for recently deployed SMs with high and low subthreshold PTSD symptoms, respectively, to a fear conditioning task and novel virtual reality paradigm (Virtual Iraq). The high symptom group demonstrated elevated heart rate (HR) response during fear conditioning. Virtual reality sequences evoked significant HR responses which predicted variance of the PTSD Checklist-Military Version self-report. Our results support the value of physiologic assessment during fear conditioning and combat-related virtual reality exposure as complementary tools in detecting subthreshold PTSD symptoms in Veterans. PMID:23792855

  12. Advanced neuroblastoma: improved response rate using a multiagent regimen (OPEC) including sequential cisplatin and VM-26.

    PubMed

    Shafford, E A; Rogers, D W; Pritchard, J

    1984-07-01

    Forty-two children, all over one year of age, were given vincristine, cyclophosphamide, and sequentially timed cisplatin and VM-26 (OPEC) or OPEC and doxorubicin (OPEC-D) as initial treatment for newly diagnosed stage III or IV neuroblastoma. Good partial response was achieved in 31 patients (74%) overall and in 28 (78%) of 36 patients whose treatment adhered to the chemotherapy protocol, compared with a 65% response rate achieved in a previous series of children treated with pulsed cyclophosphamide and vincristine with or without doxorubicin. Only six patients, including two of the six children whose treatment did not adhere to protocol, failed to respond, but there were five early deaths from treatment-related complications. Tumor response to OPEC, which was the less toxic of the two regimens, was at least as good as tumor response to OPEC-D. Cisplatin-induced morbidity was clinically significant in only one patient and was avoided in others by careful monitoring of glomerular filtration rate and hearing. Other centers should test the efficacy of OPEC or equivalent regimens in the treatment of advanced neuroblastoma. PMID:6539811

  13. CHARADE: A characteristic code for calculating rate-dependent shock-wave response

    SciTech Connect

    Johnson, J.N.; Tonks, D.L.

    1991-01-01

    In this report we apply spatially one-dimensional methods and simple shock-tracking techniques to the solution of rate-dependent material response under flat-plate-impact conditions. This method of solution eliminates potential confusion of material dissipation with artificial dissipative effects inherent in finite-difference codes, and thus lends itself to accurate calculation of elastic-plastic deformation, shock-to-detonation transition in solid explosives, and shock-induced structural phase transformation. Equations are presented for rate-dependent thermoelastic-plastic deformation for (100) planar shock-wave propagation in materials of cubic symmetry (or higher). Specific numerical calculations are presented for polycrystalline copper using the mechanical threshold stress model of Follansbee and Kocks with transition to dislocation drag. A listing of the CHARADE (for characteristic rate dependence) code and sample input deck are given. 26 refs., 11 figs.

  14. Tectonic, lithologic and climatic controls on knickpoint retreat rates and landscape response times

    NASA Astrophysics Data System (ADS)

    Whittaker, Alexander; Boulton, Sarah; Kent, Emiko; Alçiçek, Cihat

    2016-04-01

    The plan-view and vertical rates at which transient knickpoints propagate through a landscape fundamentally controls geomorphic response times to tectonic and climatic perturbations. Here we present knickpoint retreat rates upstream of active faults for bedrock catchments in the Gediz graben of Turkey where past climate is well documented but where the history of faulting is not fully constrained. The rivers upstream of the normal fault-bounded graben each contain a non-lithologic knickpoint, including those that drain through inferred fault segment boundaries. Knickpoint heights measured vertically from the fault scale with footwall relief and documented fault throw (vertical displacement). Consequently, we deduce these knickpoints were initiated by an increase in slip rate on the basin-bounding fault, driven by linkage of the three main fault segments of the high-angle graben-bounding fault array. Fault interaction theory and ratios of channel steepness suggest that the slip rate enhancement factor on linkage was a factor of 3. We combine this information with geomorphic and structural constraints to estimate that linkage took place between 0.6 Ma and 1 Ma. Calculated pre- and post- linkage throw rates are 0.6 and 2 mm/yr respectively. Maximum plan-view knickpoint retreat rates upstream of the faults range from 4.5 to 28 mm/yr, and when normalised by drainage area, they are 2-7 times faster than for similar catchments upstream of normal faults in the Central Apennines of Italy and the Hatay Graben of Turkey. These knickpoint retreat rates imply a fluvial response time to fault growth and interaction of 1.6 to 2.7 My. However, marked along-strike disparities in retreat rates exist. We demonstrate that climate differences may explain the variation in rates between these study areas, but not within the Gediz graben itself. Consequently, we evaluate the extent to which measureable differences in bedrock lithology and erodibility modulate the propagation of

  15. Chemotherapy Response Rates among Endometrial Cancer Patients with Elevated Serum Platelets

    PubMed Central

    Kizer, Nora T.; Hatem, Hatem; Nugent, Elizabeth K.; Zhou, Gongfu; Moore, Kathleen; Heller, Paul; Mutch, David G.; Thaker, Premal H.

    2015-01-01

    Objective This retrospective study evaluates the influence of serum platelet count on chemotherapy response rates among women with endometrial cancer. Methods From three separate cancer centers, a total of 318 patients with endometrial cancer who received post-operative chemotherapy between June 1999 and October 2009 were retrospectively identified. Endometrioid, serous, clear cell, and carcinosarcoma histologies were included. Subjects were classified as having an elevated platelet count if their serum platelet count was greater than 400 × 109/L at the time of initial diagnosis. Primary outcome was chemotherapy response, classified as either complete or partial/refractory. Secondary outcomes were disease free and disease specific survival (DFS, DSS). Chi-square and Student t-tests were performed as appropriate. Kaplan-Meier curves and Cox proportional hazards models were used to assess serum platelet effect on survival. Results There were 125 deaths, 76 recurrences, and 48 disease progressions. Of the total group, 53 (16.7%) were categorized as having an elevated platelet count. An elevated platelet count was associated with a lower chemotherapy response rate in univariate analysis (HR 2.8; 95% CI 1.46, 5.38; p <0.01). Multivariate analysis showed elevated platelets to be independently associated with decreased DFS (HR 2.24; 95% CI 1.26, 3.98; p<0.01) but not DSS (HR 1.03, 95%CI 0.56, 1.88, p=0.93). Conclusions Endometrial cancer patients with an elevated serum platelet count > 400 × 109/L may have lower chemotherapy response rates and are at increased risk for recurrence when compared to patients with a count within normal range. PMID:26098089

  16. Heart rate and blood lactate responses to changquan and daoshu forms of modern wushu.

    PubMed

    Ribeiro, Jerri Luiz; de Castro, Bruno Ogoday S D; Rosa, Caio S; Baptista, Rafael R; Oliveira, Alvaro R

    2006-01-01

    The development of specific training designed to enhance physiological aspects of performance relies heavily on the availability of accurate and validity physiological data. In the combat sport of Wushu, katas are used to develop aerobic fitness. It is arguably important to assess and monitor heart rate (HR) and lactate (La) responses when designing effective training programs. The aim of this pilot study was to investigate heart rate and lactate responses to forms execution among Wushu combatants. Male elite modern Wushu athletes (n = 4) from a South Brazilian regional team participated in the study. Athletes were aged 22.5 ± 2.08 years old and had at least eight years of Wushu experience. Athletes carried out the Changquan and Daoshu forms in random order, HR and La were measured pre- and post-exercise. Results indicate that HR was 176 ± 3 and 176 ± 2 bpm and La was 4.38 ± 1.3 and 5.15 ± 1.07 mmol·l(-1) for Changquan and Daoshu forms, respectively. There were no significantly differences in HR and La between the two forms. HR values represent 89.2 ± 1.1 and 89.1 ± 1.8% of age-predicted maximal heart rate and lactate was near of 4 mmol·l(-1) point. In conclusion, training programs to Wushu combatants could target the range of physiological values cited above with no differences between two forms. Key PointsHeart rate and lactate responses are not significantly different between Changquan and Daoshu forms for Wushu combatants.The Wushu katas could be used to develop aerobic fitness.

  17. Heart Rate And Blood Lactate Responses To Changquan And Daoshu Forms Of Modern Wushu

    PubMed Central

    Ribeiro, Jerri Luiz; de Castro, Bruno Ogoday S. D.; Rosa, Caio S.; Baptista, Rafael R.; Oliveira, Alvaro R.

    2006-01-01

    The development of specific training designed to enhance physiological aspects of performance relies heavily on the availability of accurate and validity physiological data. In the combat sport of Wushu, katas are used to develop aerobic fitness. It is arguably important to assess and monitor heart rate (HR) and lactate (La) responses when designing effective training programs. The aim of this pilot study was to investigate heart rate and lactate responses to forms execution among Wushu combatants. Male elite modern Wushu athletes (n = 4) from a South Brazilian regional team participated in the study. Athletes were aged 22.5 ± 2.08 years old and had at least eight years of Wushu experience. Athletes carried out the Changquan and Daoshu forms in random order, HR and La were measured pre- and post-exercise. Results indicate that HR was 176 ± 3 and 176 ± 2 bpm and La was 4.38 ± 1.3 and 5.15 ± 1.07 mmol·l-1 for Changquan and Daoshu forms, respectively. There were no significantly differences in HR and La between the two forms. HR values represent 89.2 ± 1.1 and 89.1 ± 1.8% of age-predicted maximal heart rate and lactate was near of 4 mmol·l-1 point. In conclusion, training programs to Wushu combatants could target the range of physiological values cited above with no differences between two forms. Key Points Heart rate and lactate responses are not significantly different between Changquan and Daoshu forms for Wushu combatants. The Wushu katas could be used to develop aerobic fitness. PMID:24357970

  18. Nonlinear modeling on rate dependent ferroelectric and ferroelastic response of 1-3 piezocomposites

    NASA Astrophysics Data System (ADS)

    Jayendiran, R.; Arockiarajan, A.

    2016-06-01

    The effect of loading rate on ferroelectric and ferroelastic behavior of 1-3 piezocomposites is presented in this work. Experiments are conducted for various loading rates under different loading conditions such as electrical and electromechanical to measure the rate dependent response of 1-3 piezocomposite compared with bulk piezoceramics. A thermodynamic based rate dependent domain switching criteria has been proposed to predict the ferroelectric and ferroelastic behavior of homogenized 1-3 piezocomposites. In this model, volume fraction of six distinct uni-axial variants are used as internal variables to describe the microscopic state of the material. Plasticity based kinematic hardening parameter is introduced as a function of internal variables to describe the grain boundary effects. Homogenization of 1-3 piezocomposite material properties are obtained by finite element (FE) resonator models using commercially available FE tool Abaqus. To evaluate the possible modes of vibration of 1-3 piezocomposite four different configuration of FE resonators are modeled. The FE resonator model is validated with the impedance spectra obtained experimentally for length extensional and thickness extensional resonator models. The predicted effective properties using the resonance based technique are incorporated in the proposed rate dependent macromechanical model to study the behavior of 1-3 piezocomposites. The simulated results are compared with the experimental observations.

  19. Rates of formation and dissipation of clumping reveal lagged responses in tropical tree populations.

    PubMed

    Detto, Matteo; Muller-Landau, Helene C

    2016-05-01

    The dynamics of spatial patterns of plant populations can provide important information about underlying processes, yet they have received relatively little attention to date. Here we investigate the rates of formation and dissipation of clusters and the relationship of these rates to the degree of aggregation (clumping) in models and in empirical data for tropical trees. In univariate models, exact solutions and simulations show that the rate of change of spatial patterns has a specific, linear relationship to the degree of aggregation at all scales. Shorter dispersal and/or weaker negative density dependence (NDD) result in both denser and longer-lasting clusters. In multivariate host-parasite models in contrast, the rate of change of spatial pattern is faster relative to the level of aggrega- tion. We then analyzed the dynamics of spatial patterns of stems ≥ 1 cm diameter in 221 tropical tree species from seven censuses spanning 28 yr. We found that for most species, the rates of change in spatial patterns were faster than predicted from univariate models given their aggregation. This indicates that more complex dynamics involving multivariate interactions induce time lags in responses to aggregation in these species. Such lags could arise, for example, if it takes time for natural enemies to locate aggregations of their hosts. This combination of theoretical and empirical results thus shows that complex multilevel models are needed to capture spatiotemporal dynamics of tropical forests and provides new insights into the processes structuring tropical plant communities. PMID:27349094

  20. Excessive heart rate response to orthostatic stress in postural tachycardia syndrome is not caused by anxiety.

    PubMed

    Masuki, Shizue; Eisenach, John H; Johnson, Christopher P; Dietz, Niki M; Benrud-Larson, Lisa M; Schrage, William G; Curry, Timothy B; Sandroni, Paola; Low, Phillip A; Joyner, Michael J

    2007-03-01

    Postural tachycardia syndrome (POTS) is characterized by excessive increases in heart rate (HR) without hypotension during orthostasis. The relationship between the tachycardia and anxiety is uncertain. Therefore, we tested whether the HR response to orthostatic stress in POTS is primarily related to psychological factors. POTS patients (n = 14) and healthy controls (n = 10) underwent graded venous pooling with lower body negative pressure (LBNP) to -40 mmHg while wearing deflated antishock trousers. "Sham" venous pooling was performed by 1) trouser inflation to 5 mmHg during LBNP and 2) vacuum pump activation without LBNP. HR responses to mental stress were also measured in both groups, and a questionnaire was used to measure psychological parameters. During LBNP, HR in POTS patients increased 39 +/- 5 beats/min vs. 19 +/- 3 beats/min in control subjects at -40 mmHg (P < 0.01). LBNP with trouser inflation markedly blunted the HR responses in the patients (9 +/- 2 beats/min) and controls (2 +/- 1 beats/min), and there was no HR increase during vacuum application without LBNP in either group. HR responses during mental stress were not different in the patients and controls (18 +/- 2 vs. 19 +/- 1 beats/min; P > 0.6). Anxiety, somatic vigilance, and catastrophic cognitions were significantly higher in the patients (P < 0.05), but they were not related to the HR responses during LBNP or mental stress (P > 0.1). These results suggest that the HR response to orthostatic stress in POTS patients is not caused by anxiety but that it is a physiological response that maintains arterial pressure during venous pooling.

  1. Radiation response of industrial materials: Dose-rate and morphology implications

    NASA Astrophysics Data System (ADS)

    Berejka, Anthony J.

    2007-08-01

    Industrial uses of ionizing radiation mostly rely upon high current, high dose-rate (100 kGy/s) electron beam (EB) accelerators. To a lesser extent, industry uses low dose-rate (2.8 × 10-3 kGy/s) radioactive Cobalt-60 as a gamma source, generally for some rather specific purposes, as medical device sterilization and the treatment of food and foodstuffs. There are nearly nine times as many (∼1400) high current EB units in commercial operation than gamma sources (∼160). However, gamma sources can be easily scaled-down so that much research on materials effects is conducted using gamma radiation. Likewise, laboratories are more likely to have very low beam current and consequently low dose-rate accelerators such as Van de Graaff generators and linear accelerators. With the advent of very high current EB accelerators, X-ray processing has become an industrially viable option. With X-rays from high power sources, dose-rates can be modulated based upon accelerator power and the attenuation of the X-ray by the distance of the material from the X-ray target. Dose and dose-rate dependence has been found to be of consequence in several commercial applications which can employ the use of ionizing radiation. The combination of dose and dose-rate dependence of the polymerization and crosslinking of wood impregnants and of fiber composite matrix materials can yield more economically viable results which have promising commercial potential. Monomer and oligomer structure also play an important role in attaining these desirable results. The influence of morphology is shown on the radiation response of olefin polymers, such as ethylene, propylene and isobutylene polymers and their copolymers. Both controlled morphology and controlled dose-rate have commercial consequences. These are also impacted both by the adroit selection of materials and through the possible use of X-ray processing.

  2. Gene switching rate determines response to extrinsic perturbations in the self-activation transcriptional network motif.

    PubMed

    de Franciscis, Sebastiano; Caravagna, Giulio; Mauri, Giancarlo; d'Onofrio, Alberto

    2016-01-01

    Gene switching dynamics is a major source of randomness in genetic networks, also in the case of large concentrations of the transcription factors. In this work, we consider a common network motif - the positive feedback of a transcription factor on its own synthesis - and assess its response to extrinsic noises perturbing gene deactivation in a variety of settings where the network might operate. These settings are representative of distinct cellular types, abundance of transcription factors and ratio between gene switching and protein synthesis rates. By investigating noise-induced transitions among the different network operative states, our results suggest that gene switching rates are key parameters to shape network response to external perturbations, and that such response depends on the particular biological setting, i.e. the characteristic time scales and protein abundance. These results might have implications on our understanding of irreversible transitions for noise-related phenomena such as cellular differentiation. In addition these evidences suggest to adopt the appropriate mathematical model of the network in order to analyze the system consistently to the reference biological setting. PMID:27256916

  3. Clinical application of fluctuation dissipation theory - Prediction of heart rate response to spontaneous breathing trial

    NASA Astrophysics Data System (ADS)

    Niestemski, Liang R.; Chen, Man; Prevost, Robert; McRae, Michael; Cholleti, Sharath; Najarro, Gabriel; Buchman, Timothy G.; Deem, Michael W.

    2013-03-01

    Contrary to the traditional view of the healthy physiological state as being a single static state, variation in physiologic variables has more recently been suggested to be a key component of the healthy state. Indeed, aging and disease are characterized by a loss of such variability. We apply the conceptual framework of fluctuation-dissipation theory (FDT) to predict the response to a common clinical intervention from historical fluctuations in physiologic time series data. The non-equilibrium FDT relates the response of a system to a perturbation to natural fluctuations in the stationary state of the system. We seek to understand with the FDT a common clinical perturbation, the spontaneous breathing trial (SBT), in which mechanical ventilation is briefly suspended while the patient breathes freely for a period of time. As a stress upon the heart of the patient, the SBT can be characterized as a perturbation of heart rate dynamics. A non-equilibrium, but steady-state FDT allows us to predict the heart rate recovery after the SBT stress. We show that the responses of groups of similar patients to the spontaneous breathing trial can be predicted by this approach. This mathematical framework may serve as part of the basis for personalized critical care.

  4. Gene switching rate determines response to extrinsic perturbations in the self-activation transcriptional network motif

    PubMed Central

    de Franciscis, Sebastiano; Caravagna, Giulio; Mauri, Giancarlo; d’Onofrio, Alberto

    2016-01-01

    Gene switching dynamics is a major source of randomness in genetic networks, also in the case of large concentrations of the transcription factors. In this work, we consider a common network motif - the positive feedback of a transcription factor on its own synthesis - and assess its response to extrinsic noises perturbing gene deactivation in a variety of settings where the network might operate. These settings are representative of distinct cellular types, abundance of transcription factors and ratio between gene switching and protein synthesis rates. By investigating noise-induced transitions among the different network operative states, our results suggest that gene switching rates are key parameters to shape network response to external perturbations, and that such response depends on the particular biological setting, i.e. the characteristic time scales and protein abundance. These results might have implications on our understanding of irreversible transitions for noise-related phenomena such as cellular differentiation. In addition these evidences suggest to adopt the appropriate mathematical model of the network in order to analyze the system consistently to the reference biological setting. PMID:27256916

  5. Differential heart rate responses to social and monetary reinforcement in women with obesity.

    PubMed

    Kube, Jana; Schrimpf, Anne; García-García, Isabel; Villringer, Arno; Neumann, Jane; Horstmann, Annette

    2016-06-01

    Obesity is often accompanied by weight stigmatization; subsequently, individuals with obesity frequently face social rejection. It has been shown that recurrent negative social experiences can alter the perception of social cues. However, the way individuals with obesity process social stimuli is not well understood. This study aims to investigate obesity-related alterations in social compared to nonsocial information processing. Women with obesity (n = 14) and without obesity (n = 14) participated in a social and a monetary incentive delay task in which they anticipated and received positive, negative, and neutral outcomes in the form of faces or money. During the experiment, phasic heart rate changes and reaction times were measured. Women with obesity, compared to lean women, exhibited a stronger differentiation during the anticipation of monetary and social reinforcement, showing slower reaction times to social cues compared to monetary cues. During the outcome processing phase, women with obesity relative to controls demonstrated diminished heart rate responses particularly to negative social outcomes. Interestingly, differences in cardiac responses in participants with obesity were moderated by weight-related teasing experiences. In women with obesity, a higher BMI was associated with blunted cardiac responses to social cues relative to monetary cues only if they reported more emotional pain after weight-related teasing. Our results contribute to a better understanding of social information processing in obesity and give first evidence for the role of negative social experiences in reinforcement processing. PMID:26871590

  6. Neural correlates of fear-induced sympathetic response associated with the peripheral temperature change rate.

    PubMed

    Yoshihara, Kazufumi; Tanabe, Hiroki C; Kawamichi, Hiroaki; Koike, Takahiko; Yamazaki, Mika; Sudo, Nobuyuki; Sadato, Norihiro

    2016-07-01

    Activation of the sympathetic nervous system is essential for coping with environmental stressors such as fearful stimuli. Recent human imaging studies demonstrated that activity in some cortical regions, such as the anterior cingulate cortex (ACC) and anterior insula cortex (aIC), is related to sympathetic activity. However, little is known about the functional brain connectivity related to sympathetic response to fearful stimuli. The participants were 32 healthy, right-handed volunteers. Functional magnetic resonance imaging (fMRI) was used to examine brain activity when watching horror and control movies. Fingertip temperature was taken during the scanning as a measure of sympathetic response. The movies were watched a second time, and the degree of fear (9-point Likert-type scale) was evaluated every three seconds. The brain activity of the ACC, bilateral aIC, and bilateral anterior prefrontal cortex (aPFC) was correlated with the change rate of fingertip temperature, with or without fearful stimuli. Functional connectivity analysis revealed significantly greater positive functional connectivity between the amygdala and the ACC and between the amygdala and the aIC when watching the horror movie than when watching the control movie. Whole-brain psycho-physiological interaction (PPI) analysis revealed that the functional connectivity between the left amygdala and the ACC was modulated according to the fear rating. Our results indicate that the increased functional connectivity between the left amygdala and the ACC represents a sympathetic response to fearful stimuli. PMID:27107469

  7. Explaining Cross-State Differences in Elderly Suicide Rates and Identifying State-Level Public Policy Responses that Reduce Rates

    ERIC Educational Resources Information Center

    Giles-Sims, Jean; Lockhart, Charles

    2006-01-01

    Elderly Americans commit suicide at higher rates than other age groups. We contend that macro- and micro-social variables contribute distinct aspects to explanations of this tragic loss: the former focus on circumstances that affect overall rates, the latter reveal why certain individuals succumb to suicide. Our analysis focuses on the…

  8. Response of individual thoracolumbar spine ligaments under high-rate deformation.

    PubMed

    Iwaskiw, Alexander S; Armiger, Robert S; Ott, Kyle A; Wickwire, Alexis C M; Merkle, Andrew C

    2012-01-01

    Under-Body Blast (UBB) has emerged as the predominant threat to ground vehicles and Warfighter survivability. The force transference from the vehicle structure to the human body has resulted in serious injuries, with the thoracolumbar spine frequently damaged. Computational models of the human body are being generated to model human response and develop injury mitigation strategies. To effectively model the spine mechanics, the thoracolumbar ligaments, which serve varying roles in contributing to spine stability, must be characterized at relevant strains and strain rates. Adaptation of cervical spine testing methods has allowed for testing of isolated spinal ligaments including the Anterior Longitudinal Ligament (ALL), Posterior Longitudinal Ligament (PLL), and Ligamentum Flavum (LF). A high-rate servo-hydraulic test machine was used to execute a tensile test protocol for 24 complexes with loading rates ranging from 240 - 2800 mm/s and displacements of 25%, 50%, 75%, 100%, and 300% of the measured ligament length. Non-contact strain field measurements were recorded to produce a three dimensional strain field of the ligament surface. In order to provide the ligament data in a form which can be incorporated in the human computational models, analytical methods for modeling the ligament response are being investigated. Ultimately, this model will be optimized to be utilized in computational models of the lumbar spine. PMID:22846283

  9. Baroreflex-mediated heart rate and vascular resistance responses 24 h after maximal exercise

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    2003-01-01

    INTRODUCTION: Plasma volume, heart rate (HR) variability, and stimulus-response relationships for baroreflex control of forearm vascular resistance (FVR) and HR were studied in eight healthy men after and without performing a bout of maximal exercise to test the hypotheses that acute expansion of plasma volume is associated with 1) reduction in baroreflex-mediated HR response, and 2) altered operational range for central venous pressure (CVP). METHODS: The relationship between stimulus (DeltaCVP) and vasoconstrictive reflex response (DeltaFVR) during unloading of cardiopulmonary baroreceptors was assessed with lower-body negative pressure (LBNP, 0, -5, -10, -15, -20 mm Hg). The relationship between stimulus (Deltamean arterial pressure (MAP)) and cardiac reflex response (DeltaHR) during loading of arterial baroreceptors was assessed with steady-state infusion of phenylephrine (PE) designed to increase MAP by 15 mm Hg alone and during application of LBNP (PE+LBNP) and neck pressure (PE+LBNP+NP). Measurements of vascular volume and autonomic baroreflex responses were conducted on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested 24 h after graded cycle exercise to volitional exhaustion. On another day, measurement of baroreflex response was repeated with no exercise (control). The order of exercise and control treatments was counterbalanced. RESULTS: Baseline CVP was elevated (P = 0.04) from a control value of 10.5 +/- 0.4 to 12.3 +/- 0.4 mm Hg 24 h after exercise. Average DeltaFVR/DeltaCVP during LBNP was not different (P = 0.942) between the exercise (-1.35 +/- 0.32 pru x mm Hg-1) and control (-1.32 +/- 0.36 pru x mm Hg-1) conditions. However, maximal exercise caused a shift along the reflex response relationship to a higher CVP and lower FVR. HR baroreflex response (DeltaHR/DeltaMAP) to PE+LBNP+NP was lower (P = 0.015) after maximal exercise (-0.43 +/- 0.15 beats x min-1 x mm Hg-1) compared with the control

  10. The deformation response of three-dimensional woven composites subjected to high rates of loading

    NASA Astrophysics Data System (ADS)

    Pankow, Mark Robert

    The use of polymer matrix composites is widespread, with development in automotive, aerospace and recreational equipment. These applications have produced loading scenarios which are unfamiliar and not well understood. Several applications involve impact loading, which produces large strain rates and delamination failure. New manufacturing methods have led to three dimensional (3D) weave geometries that provide composites with damage protection. This is accomplished through elimination of delamination, and localizing the extent of damage. The present work is a combined experimental and computational study aimed at developing a mechanism based deformation response model for 3D woven composites, including the prediction of failure strengths at high loading rates. Three unique experimental configurations have been developed; along with finite element based simulations to predict the material response and failure mechanisms that are experimentally observed. End Notch Flexure (ENF) tests were used to determine the effectiveness of the Z-fiber at resisting crack propagation. The crack propagation was found to have rate dependent properties, with architecture based parameters required to predict the strength and resistance. The computational results reinforced the experimental observations. A new FE implementation captured the effectiveness of the Z-fiber reinforcement bridging the growing crack. Shock impact testing was performed to simulate the effects of blast loading on the material. New experimental measurement methods were utilized to record the deformations and strains which led to observations of matrix micro-cracking, the first failure mode. Computational models were developed to predict the material behavior subjected to shock loading, including matrix micro-cracking, which was predicted accurately. Finally, split Hopkinson pressure bar (SHPB) testing was done to understand the high strain rate behavior of the material in compression in all three directions. The

  11. Evaluation and prediction of material response during superplastic forming at various strain rates

    NASA Astrophysics Data System (ADS)

    Agarwal, Sumit

    constitutive response of the material. The simulations included grain boundary diffusion, grain boundary sliding and dislocation creep mechanisms. The predictions of simulations are in good agreement with the experimental results. The results agree with the transition in the mechanism of deformation with increasing strain rate, from grain boundary sliding to dislocation creep.

  12. Genotypic variation in host response to infection affects parasite reproductive rate.

    PubMed

    Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L

    2016-02-01

    Parasite fitness is largely influenced by a variation in host response due to the host's genetic background. Here we investigated the impact of host genotype on pathogen success in the snail vector of its castrating parasite, Schistosoma mansoni. We infected five inbred lines of Biomphalaria glabrata with two infection doses and followed their growth, reproductive output and parasite production throughout the course of infection. There was no difference in resistance to infection among inbred lines, but lines varied in their responses to infection and the numbers of parasites produced. Snails did not compensate for castration by increasing their fecundity during the early phase of infection (fecundity compensation). However, some lines were able to delay parasite shedding for up to 30 weeks, thus prolonging reproduction before the onset of castration. Here we propose this strategy as a novel defense against castrating pathogens in snails. Gigantism, a predicted outcome of castration due to energy reallocation, occurred early in infection (<15 weeks) and was not universal among the snail lines. Lines that did not show gigantism were also characterised by a high parasite production rate and low survivorship, perhaps indicating energy reallocation into parasite production and costly immune defense. We observed no differences in total parasite production among lines throughout the entire course of infection, although lines differed in their parasite reproductive rate. The average rate of parasite production varied among lines from 1300 to 2450 cercariae within a single 2h shedding period, resulting in a total production of 6981-29,509 cercariae over the lifetime of a single snail. Regardless of genetic background, snail size was a strong predictor of parasite reproduction: each millimetre increase in snail size at the time of the first shed resulted in up to 3500 more cercariae over the lifetime of the snail. The results of this study provide a detailed picture of

  13. Genotypic variation in host response to infection affects parasite reproductive rate.

    PubMed

    Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L

    2016-02-01

    Parasite fitness is largely influenced by a variation in host response due to the host's genetic background. Here we investigated the impact of host genotype on pathogen success in the snail vector of its castrating parasite, Schistosoma mansoni. We infected five inbred lines of Biomphalaria glabrata with two infection doses and followed their growth, reproductive output and parasite production throughout the course of infection. There was no difference in resistance to infection among inbred lines, but lines varied in their responses to infection and the numbers of parasites produced. Snails did not compensate for castration by increasing their fecundity during the early phase of infection (fecundity compensation). However, some lines were able to delay parasite shedding for up to 30 weeks, thus prolonging reproduction before the onset of castration. Here we propose this strategy as a novel defense against castrating pathogens in snails. Gigantism, a predicted outcome of castration due to energy reallocation, occurred early in infection (<15 weeks) and was not universal among the snail lines. Lines that did not show gigantism were also characterised by a high parasite production rate and low survivorship, perhaps indicating energy reallocation into parasite production and costly immune defense. We observed no differences in total parasite production among lines throughout the entire course of infection, although lines differed in their parasite reproductive rate. The average rate of parasite production varied among lines from 1300 to 2450 cercariae within a single 2h shedding period, resulting in a total production of 6981-29,509 cercariae over the lifetime of a single snail. Regardless of genetic background, snail size was a strong predictor of parasite reproduction: each millimetre increase in snail size at the time of the first shed resulted in up to 3500 more cercariae over the lifetime of the snail. The results of this study provide a detailed picture of

  14. The frequency response of dynamic friction: Enhanced rate-and-state models

    NASA Astrophysics Data System (ADS)

    Cabboi, A.; Putelat, T.; Woodhouse, J.

    2016-07-01

    The prediction and control of friction-induced vibration requires a sufficiently accurate constitutive law for dynamic friction at the sliding interface: for linearised stability analysis, this requirement takes the form of a frictional frequency response function. Systematic measurements of this frictional frequency response function are presented for small samples of nylon and polycarbonate sliding against a glass disc. Previous efforts to explain such measurements from a theoretical model have failed, but an enhanced rate-and-state model is presented which is shown to match the measurements remarkably well. The tested parameter space covers a range of normal forces (10-50 N), of sliding speeds (1-10 mm/s) and frequencies (100-2000 Hz). The key new ingredient in the model is the inclusion of contact stiffness to take into account elastic deformations near the interface. A systematic methodology is presented to discriminate among possible variants of the model, and then to identify the model parameter values.

  15. The reliability and validity of the rating scale of criminal responsibility for mentally disordered offenders.

    PubMed

    Cai, Weixiong; Zhang, Qingting; Huang, Fuyin; Guan, Wei; Tang, Tao; Liu, Chao

    2014-03-01

    In China, the criminal responsibility of the mentally disordered offenders is divided into three levels, there are the whole responsibility, diminished responsibility and irresponsibility. According to the Criminal Law, "If a mental disordered patient causes harmful consequences at a time when he is unable to recognize or control his own conduct, upon verification and confirmation through legal procedure, he shall not bear criminal responsibility." That means there are two standards of assessing criminal responsibility, namely volitional and cognitive capacity. It is as equal as the Mc'Naughton Rule and the Irresistible Impulse Test. But for a long time, the criminal responsibility was assessed mainly by experience because of lacking of standardized assessment instrument. Recently, we have developed "the rating scale of criminal responsibility for mentally disordered offenders (RSCRs)". The scale includes eighteen items, namely criminal motivation, aura before offense, inducement of crime, time and place and object and tool selectivity of crime, emotion during the crime, shirking responsibility after offense, concealing the truth during inquest, camouflage, understanding the nature of the offense, estimating the consequence of the offense, impairment of life ability, impairment of learning or work, impairment of insight, impairment of reality testing, and impairment of self-control. This scale can be applicable for all cases and easy to use. This scale had been tried out in several forensic psychiatry institutes, the Cronbach α of the scale is 0.93, and all items have high correlation with the total score of the scale (r=0.50-0.89). Two factors were extracted by the factorial analysis, and the cumulative squared loading was 68.62%. The scores of the three levels were 9.66 ± 5.11, 26.54 ± 5.21 and 40.08 ± 7.90 respectively and highly significant differences were observed among groups. By establishing discrimination analysis among three levels, classification

  16. High Strain-Rate Response of High Purity Aluminum at Temperatures Approaching Melt

    SciTech Connect

    Grunschel, S E; Clifton, R J; Jiao, T

    2010-01-28

    High-temperature, pressure-shear plate impact experiments were conducted to investigate the rate-controlling mechanisms of the plastic response of high-purity aluminum at high strain rates (10{sup 6} s{sup -1}) and at temperatures approaching melt. Since the melting temperature of aluminum is pressure dependent, and a typical pressure-shear plate impact experiment subjects the sample to large pressures (2 GPa-7 GPa), a pressure-release type experiment was used to reduce the pressure in order to measure the shearing resistance at temperatures up to 95% of the current melting temperature. The measured shearing resistance was remarkably large (50 MPa at a shear strain of 2.5) for temperatures this near melt. Numerical simulations conducted using a version of the Nemat-Nasser/Isaacs constitutive equation, modified to model the mechanism of geometric softening, appear to capture adequately the hardening/softening behavior observed experimentally.

  17. Groundwater Response to Precipitation Variations and Increased Abstraction Rates in the Nasia Sub-catchment, Ghana

    NASA Astrophysics Data System (ADS)

    Oteng, F. M.; Alo, C. A.; Yidana, S. M.

    2014-12-01

    There is growing concern about the sustainable use of groundwater owing to changing climatic patterns and human activities. In this study, a calibrated transient groundwater flow model for the semiarid Nasia sub-catchment of the White Volta basin in Northern Ghana is used to assess the impacts of precipitation variations and increased abstraction rates on groundwater for the period 2012-2050. The climate forcing for the future projections is derived from bias-corrected output from multiple Coupled Model Intercomparison Project phase 5 (CMIP5) climate models. The spatial and temporal variations in groundwater recharge over the calibration period are presented in this study. Details of the hydraulic properties of the aquifer system, the transient recharge and the responses of the system to the scenarios of changing recharge and increasing abstraction rates are also presented. The model provides initial basis for assessing the impacts of climate change/variability on groundwater resources fortunes in parts of the White Volta basin.

  18. Using Rating Scales for the Assessment of Physical Self-Concept: Why the Number of Response Categories Matters

    ERIC Educational Resources Information Center

    Freund, Philipp Alexander; Tietjens, Maike; Strauss, Bernd

    2013-01-01

    The current study employs Mixture Distribution Rasch models to compare the psychometric properties of two rating scale variants (original rating scale with six response categories, "N"?=?806 school students; a variant with four response categories, "N"?=?905 school students) for five specific scales of the Physical…

  19. Improving Follow-up Response Rate at Brevard Community College. Final Report from September 24, 1984 to August 31, 1985.

    ERIC Educational Resources Information Center

    Lawton, Robert E.

    A plan was developed to improve followup study response rates by refining techniques for data collection and improving student motivation to respond to daily requests. Factors affecting response rate to followup surveys were investigated, and alternative approaches were recommended. Findings indicated that current procedures--two mailouts of…

  20. The Utility of Maze Accurate Response Rate in Assessing Reading Comprehension in Upper Elementary and Middle School Students

    ERIC Educational Resources Information Center

    McCane-Bowling, Sara J.; Strait, Andrea D.; Guess, Pamela E.; Wiedo, Jennifer R.; Muncie, Eric

    2014-01-01

    This study examined the predictive utility of five formative reading measures: words correct per minute, number of comprehension questions correct, reading comprehension rate, number of maze correct responses, and maze accurate response rate (MARR). Broad Reading cluster scores obtained via the Woodcock-Johnson III (WJ III) Tests of Achievement…

  1. Heart Rate Response During Underwater Treadmill Training in Adults with Incomplete Spinal Cord Injury

    PubMed Central

    Morgan, Don W.

    2015-01-01

    Background: Walking on a submerged treadmill can improve mobility in persons displaying lower limb muscle weakness and balance deficits. Little is known, however, regarding the effect of water treadmill exercise on cardiac performance in persons with incomplete spinal cord injury (iSCI). Objective: To assess heart rate response during underwater treadmill training (UTT) in adults with iSCI. Methods: Seven males and 4 females with iSCI (age = 48 ± 13 years; 5 ± 8 years after injury) completed 8 weeks of UTT (3 sessions per week; 3 walks per session) incorporating individually determined walking speeds, personalized levels of body weight unloading, and gradual, alternating increases in speed and duration. Heart rate was monitored during the last 15 seconds of the final 2 minutes of each walk. Results: Over the course of 3 biweekly periods in which walking speed remained constant, heart rate fell by 7% (7 ± 1 b•min-1; P < .001) in weeks 2 and 3, 14% (17 ± 6 b•min-1; P < .001) in weeks 4 and 5, and 17% (21 ± 11 b•min-1; P < .001) in weeks 6 and 7. Conclusion: In adults with iSCI, progressively greater absolute and relative reductions in submaximal exercise heart rate occurred after 2 months of UTT featuring a systematic increase in training volume. PMID:25762859

  2. Electromyographic, mechanomyographic, and metabolic responses during cycle ergometry at a constant rating of perceived exertion.

    PubMed

    Cochrane, Kristen C; Housh, Terry J; Jenkins, Nathaniel D M; Bergstrom, Haley C; Smith, Cory M; Hill, Ethan C; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T

    2015-11-01

    Ten subjects performed four 8-min rides (65%-80% peak oxygen consumption) to determine the physical working capacity at the OMNI rating of perceived exertion (RPE) threshold (PWCOMNI). Polynomial regression analyses were used to examine the patterns of responses for surface electromyographic (EMG) amplitude (EMG AMP), EMG mean power frequency (EMG MPF), mechanomyographic (MMG) AMP, and MMG MPF of the vastus lateralis as well as oxygen consumption rate, respiratory exchange ratio (RER), and power output (PO) were examined during a 1-h ride on a cycle ergometer at a constant RPE that corresponded to the PWCOMNI. EMG AMP and MMG MPF tracked the decreases in oxygen consumption rate, RER, and PO, while EMG MPF and MMG AMP tracked RPE. The decreases in EMG AMP and MMG MPF were likely attributable to decreases in motor unit (MU) recruitment and firing rate, while the lack of change in MMG AMP may have resulted from a balance between MU de-recruitment as PO decreased, and an increase in the ability of activated fibers to oscillate. The current findings suggested that during submaximal cycle ergometry at a constant RPE, MU de-recruitment and mechanical changes within the muscle may influence the perception of effort via feedback from group III and IV afferents.

  3. A comparative analysis of signal processing methods for motion-based rate responsive pacing.

    PubMed

    Greenhut, S E; Shreve, E A; Lau, C P

    1996-08-01

    Pacemakers that augment heart rate (HR) by sensing body motion have been the most frequently prescribed rate responsive pacemakers. Many comparisons between motion-based rate responsive pacemaker models have been published. However, conclusions regarding specific signal processing methods used for rate response (e.g., filters and algorithms) can be affected by device-specific features. To objectively compare commonly used motion sensing filters and algorithms, acceleration and ECG signals were recorded from 16 normal subjects performing exercise and daily living activities. Acceleration signals were filtered (1-4 or 15-Hz band-pass), then processed using threshold crossing (TC) or integration (IN) algorithms creating four filter/algorithm combinations. Data were converted to an acceleration indicated rate and compared to intrinsic HR using root mean square difference (RMSd) and signed RMSd. Overall, the filters and algorithms performed similarly for most activities. The only differences between filters were for walking at an increasing grade (1-4 Hz superior to 15-Hz) and for rocking in a chair (15-Hz superior to 1-4 Hz). The only differences between algorithms were for bicycling (TC superior to IN), walking at an increasing grade (IN superior to TC), and holding a drill (IN superior to TC). Performance of the four filter/algorithm combinations was also similar over most activities. The 1-4/IN (filter [Hz]/algorithm) combination performed best for walking at a grade, while the 15/TC combination was best for bicycling. However, the 15/TC combination tended to be most sensitive to higher frequency artifact, such as automobile driving, downstairs walking, and hand drilling. Chair rocking artifact was highest for 1-4/IN. The RMSd for bicycling and upstairs walking were large for all combinations, reflecting the nonphysiological nature of the sensor. The 1-4/TC combination demonstrated the least intersubject variability, was the only filter/algorithm combination

  4. Arm vs. Combined Leg and Arm Exercise: Blood Pressure Responses and Ratings of Perceived Exertion at the Same Indirectly Determined Heart Rate

    PubMed Central

    Di Blasio, Andrea; Sablone, Andrea; Civino, Paola; D’Angelo, Emanuele; Gallina, Sabina; Ripari, Patrizio

    2009-01-01

    Pre-participation screening is very important for prescribing and practising exercise safely. The aim of this study was to investigate both ratings of perceived exertion (RPE) and blood pressure responses in two different types of exercises with matching duration and indirectly determined working heart rate (HR). Participants were 23 male students, who were generally healthy but sedentary. The time course of their RPE and blood pressure during a 50- minute work-out session on an arm crank ergometer and a cross trainer were compared. RM-ANOVA showed both a higher RPE (p < 0.001) and diastolic blood pressure (DBP) (p < 0.001) response to the arm exercise that were shown significantly correlated (r = 0.883; p = 0.008). Linear regression analysis (p = 0.001) confirmed the ability to predict the time course of DBP by knowing the RPE on the arm crank ergometer. Even if people use the recommended relative intensity, the HR method is not always safe for health without pre-participation screening because exercise characteristics can negatively influence physiological responses. The HR method could be substituted by the RPE method. Key points Arm Crank Ergometer elicits a higher diastolic blood pressure response respect to Cross Trainer when people exercise at the same heart rate. Arm Crank Ergometer elicits a higher ratings of perceived exertion respect to Cross trainer when people exercise at the same heart rate. Indirect determined working heart rate is not always safe even if the theoretical intensity is that recommended for health. Rating of perceived exertion method should be used instead of heart rate method to avoid the dangerous physiological responses observed. PMID:24150004

  5. Euthanasia Acceptance: An Attitudinal Inquiry.

    ERIC Educational Resources Information Center

    Klopfer, Fredrick J.; Price, William F.

    The study presented was conducted to examine potential relationships between attitudes regarding the dying process, including acceptance of euthanasia, and other attitudinal or demographic attributes. The data of the survey was comprised of responses given by 331 respondents to a door-to-door interview. Results are discussed in terms of preferred…

  6. Evaluation of treatment response in depression studies using a Bayesian parametric cure rate model.

    PubMed

    Santen, Gijs; Danhof, Meindert; Della Pasqua, Oscar

    2008-10-01

    Efficacy trials with antidepressant drugs often fail to show significant treatment effect even though efficacious treatments are investigated. This failure can, amongst other factors, be attributed to the lack of sensitivity of the statistical method as well as of the endpoints to pharmacological activity. For regulatory purposes the most widely used efficacy endpoint is still the mean change in HAM-D score at the end of the study, despite evidence from literature showing that the HAM-D scale might not be a sensitive tool to assess drug effect and that changes from baseline at the end of treatment may not reflect the extent of response. In the current study, we evaluate the prospect of applying a Bayesian parametric cure rate model (CRM) to analyse antidepressant effect in efficacy trials with paroxetine. The model is based on a survival approach, which allows for a fraction of surviving patients indefinitely after completion of treatment. Data was extracted from GlaxoSmithKline's clinical databases. Response was defined as a 50% change from baseline HAM-D at any assessment time after start of therapy. Survival times were described by a log-normal distribution and drug effect was parameterised as a covariate on the fraction of non-responders. The model was able to fit the data from different studies accurately and results show that response to treatment does not lag for two weeks, as is mythically believed. In conclusion, we demonstrate how parameterisation of a survival model can be used to characterise treatment response in depression trials. The method contrasts with the long-established snapshot on changes from baseline, as it incorporates the time course of response throughout treatment.

  7. Item Response Theory Analyses of Adult Self-Ratings of the ADHD Symptoms in the Current Symptoms Scale

    ERIC Educational Resources Information Center

    Gomez, Rapson

    2011-01-01

    The graded response model, which is based on item response theory, was used to evaluate the psychometric properties of adult self-ratings (N = 852) of the attention deficit/hyperactivity disorder inattention, hyperactivity, and impulsivity symptoms presented in the Current Symptoms Scale. This scale has four ordered response categories. The…

  8. Elevated Vibration Perception Thresholds in CIDP Patients Indicate More Severe Neuropathy and Lower Treatment Response Rates

    PubMed Central

    Abraham, Alon; Albulaihe, Hana; Alabdali, Majed; Qrimli, Mohammad; Breiner, Ari; Barnett, Carolina; Katzberg, Hans D.; Lovblom, Leif E.; Perkins, Bruce A.; Bril, Vera

    2015-01-01

    Introduction Vibration perception threshold (VPT) examination using a neurothesiometer provides objective, sensitive and specific information, and has been utilized mainly in patients with diabetic polyneropathy. Objectives Explore the utility of VPT examination in CIDP patients. Methods CIDP subjects attending the Neuromuscular clinic between 01/2013 and 12/2014 were evaluated. Demographic data, clinical history, physical examination, VPT values, and electrophysiologic data from their charts were extracted. Results 70 charts were reviewed. 55 CIDP patients had elevated VPT, associated with higher frequency of abnormal sensory testing for various modalities (92.7% vs. 46.7%, p<0.0001), lower sensory and motor amplitudes and reduced conduction velocities on nerve conduction studies, and lower treatment response rates (54% vs. 93%, p = 0.01). Conclusion VPT examination is a simple tool, which is a reliable and sensitive measure not only for diabetic neuropathy, but also for CIDP. Moreover, in CIDP, elevated VPT values are also associated with lower treatment response rates. PMID:26545096

  9. "Value" of improved treadmill exercise capacity: lessons from a study of rate responsive pacing

    PubMed Central

    Staniforth, A; Andrews, R; Harrison, M; Perry, A; Cowley, A

    1998-01-01

    Objectives—To compare the value of a series of cardiovascular measurements in patients with symptomatic disease receiving an effective treatment (rate responsive pacing).
Patients—12 pacemaker dependent patients with VVIR units.
Interventions—Single blind crossover between VVI and VVIR.
Outcome measures—Exercise capacity was assessed by treadmill tests (modified Bruce protocol and a fixed workload protocol) with respiratory gas analysis. Self paced corridor walk tests were also undertaken. Quality of life (QOL) was assessed by questionnaire. Daily activity was measured in the patients' homes using shoe and belt pedometers.
Results—Treadmill tests and QOL questionnaires correctly identified the clinical benefit associated with VVIR. The modified Bruce protocol was superior to the fixed workload protocol as it was better tailored to the fairly well preserved exercise capacity of the patients. Symptom scores, but not walking times, were improved with VVIR during corridor walk tests. VVIR did not improve daily activity measured using either the belt or shoe pedometers.
Conclusions—VVIR pacing improved some but not all measures of exercise capacity. This finding illustrates the difficulty of selecting an instrument to measure symptomatic improvement in clinical research; and raises the question, what is the best way of measuring exercise capacity?

 Keywords: rate responsive pacing;  exercise capacity;  quality of life PMID:9875118

  10. Cortical Network Models of Firing Rates in the Resting and Active States Predict BOLD Responses.

    PubMed

    Bennett, Maxwell R; Farnell, Les; Gibson, William G; Lagopoulos, Jim

    2015-01-01

    Measurements of blood oxygenation level dependent (BOLD) signals have produced some surprising observations. One is that their amplitude is proportional to the entire activity in a region of interest and not just the fluctuations in this activity. Another is that during sleep and anesthesia the average BOLD correlations between regions of interest decline as the activity declines. Mechanistic explanations of these phenomena are described here using a cortical network model consisting of modules with excitatory and inhibitory neurons, taken as regions of cortical interest, each receiving excitatory inputs from outside the network, taken as subcortical driving inputs in addition to extrinsic (intermodular) connections, such as provided by associational fibers. The model shows that the standard deviation of the firing rate is proportional to the mean frequency of the firing when the extrinsic connections are decreased, so that the mean BOLD signal is proportional to both as is observed experimentally. The model also shows that if these extrinsic connections are decreased or the frequency of firing reaching the network from the subcortical driving inputs is decreased, or both decline, there is a decrease in the mean firing rate in the modules accompanied by decreases in the mean BOLD correlations between the modules, consistent with the observed changes during NREM sleep and under anesthesia. Finally, the model explains why a transient increase in the BOLD signal in a cortical area, due to a transient subcortical input, gives rises to responses throughout the cortex as observed, with these responses mediated by the extrinsic (intermodular) connections.

  11. Mathematical model of cycad cones' thermogenic temperature responses: inverse calorimetry to estimate metabolic heating rates.

    PubMed

    Roemer, R B; Booth, D; Bhavsar, A A; Walter, G H; Terry, L I

    2012-12-21

    A mathematical model based on conservation of energy has been developed and used to simulate the temperature responses of cones of the Australian cycads Macrozamia lucida and Macrozamia. macleayi during their daily thermogenic cycle. These cones generate diel midday thermogenic temperature increases as large as 12 °C above ambient during their approximately two week pollination period. The cone temperature response model is shown to accurately predict the cones' temperatures over multiple days as based on simulations of experimental results from 28 thermogenic events from 3 different cones, each simulated for either 9 or 10 sequential days. The verified model is then used as the foundation of a new, parameter estimation based technique (termed inverse calorimetry) that estimates the cones' daily metabolic heating rates from temperature measurements alone. The inverse calorimetry technique's predictions of the major features of the cones' thermogenic metabolism compare favorably with the estimates from conventional respirometry (indirect calorimetry). Because the new technique uses only temperature measurements, and does not require measurements of oxygen consumption, it provides a simple, inexpensive and portable complement to conventional respirometry for estimating metabolic heating rates. It thus provides an additional tool to facilitate field and laboratory investigations of the bio-physics of thermogenic plants. PMID:22995822

  12. Chronic intermittent hypoxia-hypercapnia blunts heart rate responses and alters neurotransmission to cardiac vagal neurons.

    PubMed

    Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David

    2014-07-01

    Patients with obstructive sleep apnoea experience chronic intermittent hypoxia-hypercapnia (CIHH) during sleep that elicit sympathetic overactivity and diminished parasympathetic activity to the heart, leading to hypertension and depressed baroreflex sensitivity. The parasympathetic control of heart rate arises from pre-motor cardiac vagal neurons (CVNs) located in nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMNX). The mechanisms underlying diminished vagal control of heart rate were investigated by studying the changes in blood pressure, heart rate, and neurotransmission to CVNs evoked by acute hypoxia-hypercapnia (H-H) and CIHH. In vivo telemetry recordings of blood pressure and heart rate were obtained in adult rats during 4 weeks of CIHH exposure. Retrogradely labelled CVNs were identified in an in vitro brainstem slice preparation obtained from adult rats exposed either to air or CIHH for 4 weeks. Postsynaptic inhibitory or excitatory currents were recorded using whole cell voltage clamp techniques. Rats exposed to CIHH had increases in blood pressure, leading to hypertension, and blunted heart rate responses to acute H-H. CIHH induced an increase in GABAergic and glycinergic neurotransmission to CVNs in NA and DMNX, respectively; and a reduction in glutamatergic neurotransmission to CVNs in both nuclei. CIHH blunted the bradycardia evoked by acute H-H and abolished the acute H-H evoked inhibition of GABAergic transmission while enhancing glycinergic neurotransmission to CVNs in NA. These changes with CIHH inhibit CVNs and vagal outflow to the heart, both in acute and chronic exposures to H-H, resulting in diminished levels of cardioprotective parasympathetic activity to the heart as seen in OSA patients.

  13. Offer/Acceptance Ratio.

    ERIC Educational Resources Information Center

    Collins, Mimi

    1997-01-01

    Explores how human resource professionals, with above average offer/acceptance ratios, streamline their recruitment efforts. Profiles company strategies with internships, internal promotion, cooperative education programs, and how to get candidates to accept offers. Also discusses how to use the offer/acceptance ratio as a measure of program…

  14. Heart rate responses to temperature in free-swimming Pacific bluefin tuna (Thunnus orientalis).

    PubMed

    Clark, T D; Farwell, C J; Rodriguez, L E; Brandt, W T; Block, B A

    2013-09-01

    The bluefin tuna heart remains at ambient water temperature (Ta) but must supply blood to warm regions of the body served by countercurrent vascular heat exchangers. Despite this unusual physiology, inherent difficulties have precluded an understanding of the cardiovascular responses to Ta in free-swimming bluefin tunas. We measured the heart rate (f(H)) responses of two captive Pacific bluefin tunas (Thunnus orientalis; 9.7 and 13.3 kg) over a cumulative period of 40 days. Routine f(H) during fasting in the holding tank at a Ta of 20°C was 45.1±8.0 and 40.7±6.5 beats min(-1) for Tuna 1 and Tuna 2, respectively. f(H) decreased in each fish with a Q10 temperature coefficient of 2.6 (Tuna 1) and 3.1 (Tuna 2) as Ta in the tank was slowly decreased to 15°C (~0.4°C h(-1)), despite a gradual increase in swimming speed. The same thermal challenge during digestion revealed similar thermal dependence of f(H) and indicated that the rate of visceral cooling is not buffered by the heat increment of feeding. Acutely decreasing Ta from 20 to 10°C while Tuna 1 swam in a tunnel respirometer caused a progressive increase in tail-beat frequency and oxygen consumption rate (M(O2)). f(H) of this fish decreased with a Q10 of 2.7 as Ta decreased between 20 and 15°C, while further cooling to 10°C saw a general plateau in f(H) around 35 beats min(-1) with a Q10 of 1.3. A discussion of the relationships between f(H), and haemoglobin-oxygen binding sheds further light on how bluefin cardiorespiratory systems function in a changing thermal environment.

  15. Heart rate responses to temperature in free-swimming Pacific bluefin tuna (Thunnus orientalis).

    PubMed

    Clark, T D; Farwell, C J; Rodriguez, L E; Brandt, W T; Block, B A

    2013-09-01

    The bluefin tuna heart remains at ambient water temperature (Ta) but must supply blood to warm regions of the body served by countercurrent vascular heat exchangers. Despite this unusual physiology, inherent difficulties have precluded an understanding of the cardiovascular responses to Ta in free-swimming bluefin tunas. We measured the heart rate (f(H)) responses of two captive Pacific bluefin tunas (Thunnus orientalis; 9.7 and 13.3 kg) over a cumulative period of 40 days. Routine f(H) during fasting in the holding tank at a Ta of 20°C was 45.1±8.0 and 40.7±6.5 beats min(-1) for Tuna 1 and Tuna 2, respectively. f(H) decreased in each fish with a Q10 temperature coefficient of 2.6 (Tuna 1) and 3.1 (Tuna 2) as Ta in the tank was slowly decreased to 15°C (~0.4°C h(-1)), despite a gradual increase in swimming speed. The same thermal challenge during digestion revealed similar thermal dependence of f(H) and indicated that the rate of visceral cooling is not buffered by the heat increment of feeding. Acutely decreasing Ta from 20 to 10°C while Tuna 1 swam in a tunnel respirometer caused a progressive increase in tail-beat frequency and oxygen consumption rate (M(O2)). f(H) of this fish decreased with a Q10 of 2.7 as Ta decreased between 20 and 15°C, while further cooling to 10°C saw a general plateau in f(H) around 35 beats min(-1) with a Q10 of 1.3. A discussion of the relationships between f(H), and haemoglobin-oxygen binding sheds further light on how bluefin cardiorespiratory systems function in a changing thermal environment. PMID:23661777

  16. Nonlinear modeling and control of human heart rate response during exercise with various work load intensities.

    PubMed

    Cheng, Teddy M; Savkin, Andrey V; Celler, Branko G; Su, Steven W; Wang, Lu

    2008-11-01

    The first objective of this paper is to introduce a nonlinear system to model the heart rate (HR) response during and after treadmill walking exercise. The model is a feedback interconnected system that has components to describe the central and peripheral local responses to exercise and their interactions. The parameters of the model were experimentally identified from subjects walking on a treadmill at different speeds. The stability of the obtained nonlinear model was mathematically proven. The modeling results demonstrate that the proposed model can be useful in examining the cardiovascular response to exercise. Based on the nonlinear model, the second objective is to present a computer-controlled treadmill system for the regulation of HR during treadmill exercise. The proposed nonlinear controller consists of feedforward and feedback components. The designed control system was experimentally verified and the results demonstrated that the proposed computer-controlled treadmill system regulated the HR of the experimental subjects according to two different exercising HR profiles, indicating that it can play an important role in the design of exercise protocols for individuals.

  17. Brazilian Jiu-Jitsu Simulated Competition Part I: Metabolic, Hormonal, Cellular Damage, and Heart Rate Responses.

    PubMed

    Andreato, Leonardo V; Julio, Ursula F; Panissa, Valeria L G; Esteves, João V D C; Hardt, Felipe; de Moraes, Solange M F; de Souza, Camila O; Franchini, Emerson

    2015-09-01

    The aim of this study was to analyze physiological responses in Brazilian jiu-jitsu athletes during simulated competition. To this end, 10 athletes (age: 28 ± 4 years, body mass: 81.8 ± 7.4 kg, body fat: 13.0 ± 4.8%, systematic practice: 11 ± 4 years) were analyzed in simulated competition (4 matches of 10 minutes). Blood samples were taken to assess energy demand, hormonal responses, and cell damage. Additionally, the heart rate variability (HRV) response was analyzed. The main results show that in simulated competition, during the last matches, athletes had lower lactate (p < 0.001), epinephrine (p < 0.001), norepinephrine (p < 0.001), and insulin (p = 0.002) concentrations. Increases observed in creatine kinase (p < 0.001), aspartate aminotransferase (p < 0.001), alanine aminotransferase (p = 0.007), and creatinine (p < 0.001) seen, especially, in the last matches are indicative of possible cell damage. The HRV reflected a decrease in the RR medium (average of the normal R-R intervals) (p = 0.001) during the competition. Thus, it is concluded that successive matches from competition generate a gradual decrease of adrenergic and glycolytic activities, which is accompanied by a gradual increase in cell damage markers and decrease in the RR medium of the HRV. PMID:26308831

  18. Physiological and Transcriptional Responses of Different Industrial Microbes at Near-Zero Specific Growth Rates

    PubMed Central

    Ercan, Onur; Bisschops, Markus M. M.; Overkamp, Wout; Jørgensen, Thomas R.; Ram, Arthur F.; Smid, Eddy J.; Pronk, Jack T.; Kuipers, Oscar P.

    2015-01-01

    The current knowledge of the physiology and gene expression of industrially relevant microorganisms is largely based on laboratory studies under conditions of rapid growth and high metabolic activity. However, in natural ecosystems and industrial processes, microbes frequently encounter severe calorie restriction. As a consequence, microbial growth rates in such settings can be extremely slow and even approach zero. Furthermore, uncoupling microbial growth from product formation, while cellular integrity and activity are maintained, offers perspectives that are economically highly interesting. Retentostat cultures have been employed to investigate microbial physiology at (near-)zero growth rates. This minireview compares information from recent physiological and gene expression studies on retentostat cultures of the industrially relevant microorganisms Lactobacillus plantarum, Lactococcus lactis, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus niger. Shared responses of these organisms to (near-)zero growth rates include increased stress tolerance and a downregulation of genes involved in protein synthesis. Other adaptations, such as changes in morphology and (secondary) metabolite production, were species specific. This comparison underlines the industrial and scientific significance of further research on microbial (near-)zero growth physiology. PMID:26048933

  19. Cooling rate dependent biophysical and viability response shift with attachment state in human dermal fibroblast cells.

    PubMed

    Choi, Jeunghwan; Bischof, John C

    2011-12-01

    While studies on the freezing of cells in suspension have been carried out extensively, corresponding studies with cells in the attached state and in tissue or tissue-equivalents are less developed. As attachment is a hallmark of the tissue state it is important to understand its impact on biophysics and viability to better apply freezing towards tissue preservation. The current study reports on observed biophysical response changes observed during freezing human dermal fibroblasts in suspension, attached cell, and fibrin tissue-equivalent models. Specifically, intracellular ice formation is shown to increase and dehydration is inferred to increase from suspension to attached systems. Biophysical model parameters fit to these experimental observations reflect the higher kinetics in the attached state. Post-thaw viability values from fast cooling rates were higher for suspension systems, and correlated well with the amount of IIF observed. On the other hand, viability values from slow cooling rates were higher for attached systems, although the degree of dehydration was predicted to be comparable to suspension cells. This disconnect between biophysics and viability predictions at slow rates clearly requires further investigation as it runs counter to our current understanding of dehydration injury in cells. This may suggest a possible protective effect of the attachment state on cell systems.

  20. Physiological and Transcriptional Responses of Different Industrial Microbes at Near-Zero Specific Growth Rates.

    PubMed

    Ercan, Onur; Bisschops, Markus M M; Overkamp, Wout; Jørgensen, Thomas R; Ram, Arthur F; Smid, Eddy J; Pronk, Jack T; Kuipers, Oscar P; Daran-Lapujade, Pascale; Kleerebezem, Michiel

    2015-09-01

    The current knowledge of the physiology and gene expression of industrially relevant microorganisms is largely based on laboratory studies under conditions of rapid growth and high metabolic activity. However, in natural ecosystems and industrial processes, microbes frequently encounter severe calorie restriction. As a consequence, microbial growth rates in such settings can be extremely slow and even approach zero. Furthermore, uncoupling microbial growth from product formation, while cellular integrity and activity are maintained, offers perspectives that are economically highly interesting. Retentostat cultures have been employed to investigate microbial physiology at (near-)zero growth rates. This minireview compares information from recent physiological and gene expression studies on retentostat cultures of the industrially relevant microorganisms Lactobacillus plantarum, Lactococcus lactis, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus niger. Shared responses of these organisms to (near-)zero growth rates include increased stress tolerance and a downregulation of genes involved in protein synthesis. Other adaptations, such as changes in morphology and (secondary) metabolite production, were species specific. This comparison underlines the industrial and scientific significance of further research on microbial (near-)zero growth physiology.

  1. Influence of Treatment Effectiveness Information on the Acceptability of Classroom Interventions.

    ERIC Educational Resources Information Center

    Von Brock, Mary Boone; Elliott, Stephen N.

    1987-01-01

    Investigated how information about effectiveness of three classroom interventions influences teachers' acceptability ratings. Teachers (N=216) read descriptions of either mild or severe behavior problems and rated effectiveness of either token economy, response cost, or time-out intervention. Effectiveness information accompanying each…

  2. The law of effect and avoidance: a quantitative relationship between response rate and shock-frequency reduction1

    PubMed Central

    De Villiers, Peter A.

    1974-01-01

    Two experiments were conducted to investigate the quantitative relationship between response rate and reinforcement frequency in single and multiple variable-interval avoidance schedules. Responses cancelled delivery of shocks that were scheduled by variable-interval schedules. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and reinforcement frequency on single variable-interval avoidance schedules was accurately described by Herrnstein's (1970) equation for responding on single variable-interval schedules of positive reinforcement. On multiple variable-interval avoidance schedules with brief components, asymptotic relative response rate matched relative shock-frequency reduction. The results suggest that many interactions between response rates and shock-frequency reduction in avoidance can be understood within the framework of the generalized matching relation, as applied by Herrnstein (1970) to positive reinforcement. PMID:16811740

  3. Effects of metabolic rate on thermal responses at different air velocities in -10 degrees C.

    PubMed

    Mäkinen, T T; Gavhed, D; Holmér, I; Rintamäki, H

    2001-04-01

    The effects of exercise intensity on thermoregulatory responses in cold (-10 degrees C) in a 0.2 (still air, NoWi), 1.0 (Wi1), and 5.0 (Wi5) m x s(-1) wind were studied. Eight young and healthy men, preconditioned in thermoneutral (+20 degrees C) environment for 60 min, walked for 60 min on the treadmill at 2.8 km/h with different combinations of wind and exercise intensity. Exercise level was adjusted by changing the inclination of the treadmill between 0 degrees (lower exercise intensity, metabolic rate 124 W x m(-2), LE) and 6 degrees (higher exercise intensity, metabolic rate 195 W x m(-2), HE). Due to exercise increased heat production and circulatory adjustments, the rectal temperature (T(re)), mean skin temperature (Tsk) and mean body temperature (Tb) were significantly higher at the end of HE in comparison to LE in NoWi and Wi1, and T(re) and Tb also in Wi5. Tsk and Tb were significantly decreased by 5.0 m x s(-1) wind in comparison to NoWi and Wi1. The higher exercise intensity was intense enough to diminish peripheral vasoconstriction and consequently the finger skin temperature was significantly higher at the end of HE in comparison to LE in NoWi and Wi1. Mean heat flux from the skin was unaffected by the exercise intensity. At LE oxygen consumption (VO2) was significantly higher in Wi5 than NoWi and Wi1. Heart rate was unaffected by the wind speed. The results suggest that, with studied exercise intensities, produced without changes in walking speed, the metabolic rate is not so important that it should be taken into consideration in the calculation of wind chill index. PMID:11282319

  4. Effects of metabolic rate on thermal responses at different air velocities in -10 degrees C.

    PubMed

    Mäkinen, T T; Gavhed, D; Holmér, I; Rintamäki, H

    2001-04-01

    The effects of exercise intensity on thermoregulatory responses in cold (-10 degrees C) in a 0.2 (still air, NoWi), 1.0 (Wi1), and 5.0 (Wi5) m x s(-1) wind were studied. Eight young and healthy men, preconditioned in thermoneutral (+20 degrees C) environment for 60 min, walked for 60 min on the treadmill at 2.8 km/h with different combinations of wind and exercise intensity. Exercise level was adjusted by changing the inclination of the treadmill between 0 degrees (lower exercise intensity, metabolic rate 124 W x m(-2), LE) and 6 degrees (higher exercise intensity, metabolic rate 195 W x m(-2), HE). Due to exercise increased heat production and circulatory adjustments, the rectal temperature (T(re)), mean skin temperature (Tsk) and mean body temperature (Tb) were significantly higher at the end of HE in comparison to LE in NoWi and Wi1, and T(re) and Tb also in Wi5. Tsk and Tb were significantly decreased by 5.0 m x s(-1) wind in comparison to NoWi and Wi1. The higher exercise intensity was intense enough to diminish peripheral vasoconstriction and consequently the finger skin temperature was significantly higher at the end of HE in comparison to LE in NoWi and Wi1. Mean heat flux from the skin was unaffected by the exercise intensity. At LE oxygen consumption (VO2) was significantly higher in Wi5 than NoWi and Wi1. Heart rate was unaffected by the wind speed. The results suggest that, with studied exercise intensities, produced without changes in walking speed, the metabolic rate is not so important that it should be taken into consideration in the calculation of wind chill index.

  5. Impacts of warming revealed by linking resource growth rates with consumer functional responses.

    PubMed

    West, Derek C; Post, David M

    2016-05-01

    Warming global temperatures are driving changes in species distributions, growth and timing, but much uncertainty remains regarding how climate change will alter species interactions. Consumer-Resource interactions in particular can be strongly impacted by changes to the relative performance of interacting species. While consumers generally gain an advantage over their resources with increasing temperatures, nonlinearities can change this relation near temperature extremes. We use an experimental approach to determine how temperature changes between 5 and 30 °C will alter the growth of the algae Scenedesmus obliquus and the functional responses of the small-bodied Daphnia ambigua and the larger Daphnia pulicaria. The impact of warming generally followed expectations, making both Daphnia species more effective grazers, with the increase in feeding rates outpacing the increases in algal growth rate. At the extremes of our temperature range, however, warming resulted in a decrease in Daphnia grazing effectiveness. Between 25 and 30 °C, both species of Daphnia experienced a precipitous drop in feeding rates, while algal growth rates remained high, increasing the likelihood of algal blooms in warming summer temperatures. Daphnia pulicaria performed significantly better at cold temperatures than D. ambigua, but by 20 °C, there was no significant difference between the two species, and at 25 °C, D. ambigua outperformed D. pulicaria. Warming summer temperatures will favour the smaller D. ambigua, but only over a narrow temperature range, and warming beyond 25 °C could open D. ambigua to invasion from tropical species. By fitting our results to temperature-dependent functions, we develop a temperature- and density-dependent model, which produces a metric of grazing effectiveness, quantifying the grazer density necessary to halt algal growth. This approach should prove useful for tracking the transient dynamics of other density-dependent consumer

  6. Dam Breach Release of Non-Cohesive Sediments: Channel Response and Recovery Rates

    NASA Astrophysics Data System (ADS)

    Collins, M. J.; Boardman, G.; Banks, W.; Andrews, M.; Conlon, M.; Dillow, J. J. A.; Gellis, A.; Lowe, S.; McClain, S.; Miller, A. J.; Snyder, N. P.; Wilcock, P. R.

    2014-12-01

    Dam removals featuring unchecked releases of non-cohesive sediments are excellent opportunities to learn more about stream channel response to abrupt increases in bed material supply that can occur deliberately or by natural processes like landslides and volcanic eruptions. Understanding channel response to sediment pulses, including response rates, is essential because human uses of river channels and floodplains are impacted by these events as are aquatic habitats. We had the opportunity to study a dam removal site at the Simkins Dam in Maryland, USA, that shares many important geophysical attributes of another well-studied dam removal in the humid northeast United States [Merrimack Village Dam, New Hampshire; Pearson et al., 2011]. The watershed sizes are the same order of magnitude (102 km2), and at both sites relatively low head dams were removed (~ 3-4 m) and ~60,000 m3 of dominantly sand-sized sediments discharged to low-gradient reaches immediately downstream. Analyzing four years of repeat morphometry and bed sediment grain size surveys at the Simkins site on the Patapsco River, as well as continuous discharge and suspended sediment gaging data, we clearly document a two-phase response in the upstream reach as described by Pearson et al. [2011] for their New Hampshire site and noted at other dam removals [e.g., Major et al., 2012]. In the early phase, approximately 50% of the impounded sediment mass was eroded rapidly over a period of about three months when flows were very modest (Figure 1). After incision to base level and channel widening in the former impoundment, a second phase began when further erosion depended on floods large enough to access impounded sediments more distant from the newly-formed channel. We also found important differences in the upstream responses at the Maryland and New Hampshire sites that appear to be related to valley type (non-glaciated versus glaciated, respectively). Response variances immediately downstream between the

  7. Sensory and motor responses to rectal distention vary according to rate and pattern of balloon inflation.

    PubMed

    Sun, W M; Read, N W; Prior, A; Daly, J A; Cheah, S K; Grundy, D

    1990-10-01

    rectum is slowly filling. Rectal sensation and concomitant external anal sphincter activity was not associated with anal relaxation during ramp inflation; most subjects felt the sensation long after the pressure reached its lowest level. However, under all circumstances the onset of rectal sensation was associated with an increase of external anal sphincter electrical activity. In conclusion, the rectal sensory and anorectal motor responses to distention depend on the rate and pattern of distention, which may activate a different population of receptors. Results from different laboratories cannot be compared directly unless the pattern and rate of distension are the same.

  8. The effect of sampling rate and anti-aliasing filters on high-frequency response spectra

    USGS Publications Warehouse

    Boore, David M.; Goulet, Christine

    2013-01-01

    The most commonly used intensity measure in ground-motion prediction equations is the pseudo-absolute response spectral acceleration (PSA), for response periods from 0.01 to 10 s (or frequencies from 0.1 to 100 Hz). PSAs are often derived from recorded ground motions, and these motions are usually filtered to remove high and low frequencies before the PSAs are computed. In this article we are only concerned with the removal of high frequencies. In modern digital recordings, this filtering corresponds at least to an anti-aliasing filter applied before conversion to digital values. Additional high-cut filtering is sometimes applied both to digital and to analog records to reduce high-frequency noise. Potential errors on the short-period (high-frequency) response spectral values are expected if the true ground motion has significant energy at frequencies above that of the anti-aliasing filter. This is especially important for areas where the instrumental sample rate and the associated anti-aliasing filter corner frequency (above which significant energy in the time series is removed) are low relative to the frequencies contained in the true ground motions. A ground-motion simulation study was conducted to investigate these effects and to develop guidance for defining the usable bandwidth for high-frequency PSA. The primary conclusion is that if the ratio of the maximum Fourier acceleration spectrum (FAS) to the FAS at a frequency fsaa corresponding to the start of the anti-aliasing filter is more than about 10, then PSA for frequencies above fsaa should be little affected by the recording process, because the ground-motion frequencies that control the response spectra will be less than fsaa . A second topic of this article concerns the resampling of the digital acceleration time series to a higher sample rate often used in the computation of short-period PSA. We confirm previous findings that sinc-function interpolation is preferred to the standard practice of using

  9. Heart Rate Responses to Unaided Orion Side Hatch Egress in the Neutral Buoyancy Laboratory

    NASA Technical Reports Server (NTRS)

    English, Kirk L.; Hwang, Emma Y.; Ryder, Jeffrey W.; Kelly, Cody; Walker, Thomas; Ploutz-Snyder, Lori

    2016-01-01

    The Orion capsule will be the next NASA-built vehicle used for near and deep space exploration. The nominal landing scenario for Orion involves splashdown in the Pacific Ocean and subsequent aided crew egress conducted by military personnel. Contingency operations, however, require the crew to egress the capsule unaided, deploy an inflatable life raft, and to ingress the raft. Unaided egress is expected to be physiologically demanding, but no data exist to corroborate this. Thus, we evaluated the heart rate response to unaided Orion side hatch egress and raft ingress as par of the NASA crew Survival Engineering Team's evaluation of egress procedures using the Post-landing Orion Recovery Trainer (PORT) article in the Neutral Buoyancy Laboratory (NBL).

  10. Finite element simulation of rate-dependent magneto-active polymer response

    NASA Astrophysics Data System (ADS)

    Haldar, K.; Kiefer, B.; Menzel, A.

    2016-10-01

    This contribution is concerned with the embedding of constitutive relations for magneto-active polymers (MAP) into finite element simulations. To this end, a recently suggested, calibrated, and validated material model for magneto-mechanically coupled and rate-dependent MAP response is briefly summarized in its continuous and algorithmic settings. Moreover, the strongly coupled field equations of finite deformation magneto-mechanics are reviewed. For the purpose of numerical simulation, a finite element model is then established based on the usual steps of weak form representation, discretization and consistent linearization. Two verifying inhomogeneous numerical examples are presented in which a classical ‘plate with a hole’ geometry is equipped with MAP properties and subjected to different types of time-varying mechanical and magnetic loading.

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

    USGS Publications Warehouse

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

    1998-01-01

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

  12. A novel multi-responsive polyampholyte composite hydrogel with excellent mechanical strength and rapid shrinking rate.

    PubMed

    Xu, Kun; Tan, Ying; Chen, Qiang; An, Huiyong; Li, Wenbo; Dong, Lisong; Wang, Pixin

    2010-05-15

    Series of hydrophilic core-shell microgels with cross-linked poly(N-isopropylacrylamide) (PNIPAAm) as core and poly(vinyl amine) (PVAm) as shell are synthesized via surfactant-free emulsion polymerization. Then, the microgels are treated with a small amount of potassium persulfate (KPS) to generate free radicals on the amine nitrogens of PVAm, which subsequently initiate the graft copolymerization of acrylic acid (AA), acryloyloxyethyl trimethyl ammonium chloride (DAC), and acrylamide (AAm) onto microgels to prepare multi-responsive composite hydrogels. The composite hydrogels consist of cross-linked ungrafted polyampholyte chains as the first network and microgels with grafted polyampholyte chains as graft point and second network and show surprising mechanical strength and rapid response rate. The investigation shows the compress strength of composite hydrogels is up to 17-30 MPa, which is 60-100 times higher than that of the hydrogel matrix. The composite hydrogel shows reversible switch of transmittance when traveling the lowest critical temperature (LCST) of microgels. When the composite hydrogel swollen in pH 2.86 solution at ambient condition is immersed into the pH 7.00 solution at 45 °C, a rapid dynamic shrinking can be observed. And the character time (τ) of shrinking dynamic of composite hydrogel is 251.9 min, which is less than that of hydrogel matrix (τ=2273.7 min). PMID:20152987

  13. Lacustrine responses to decreasing wet mercury deposition rates: results from a case study in northern Minnesota

    USGS Publications Warehouse

    Brigham, Mark E.; Sandheinrich, Mark B.; Gay, David A.; Maki, Ryan P.; Krabbenhoft, David P.; Wiener, James G.

    2014-01-01

    We present a case study comparing metrics of methylmercury (MeHg) contamination for four undeveloped lakes in Voyageurs National Park to wet atmospheric deposition of mercury (Hg), sulfate (SO4–2), and hydrogen ion (H+) in northern Minnesota. Annual wet Hg, SO4–2, and H+ deposition rates at two nearby precipitation monitoring sites indicate considerable decreases from 1998 to 2012 (mean decreases of 32, 48, and 66%, respectively). Consistent with decreases in the atmospheric pollutants, epilimnetic aqueous methylmercury (MeHgaq) and mercury in small yellow perch (Hgfish) decreased in two of four lakes (mean decreases of 46.5% and 34.5%, respectively, between 2001 and 2012). Counter to decreases in the atmospheric pollutants, MeHgaq increased by 85% in a third lake, whereas Hgfish increased by 80%. The fourth lake had two disturbances in its watershed during the study period (forest fire; changes in shoreline inundation due to beaver activity); this lake lacked overall trends in MeHgaq and Hgfish. The diverging responses among the study lakes exemplify the complexity of ecosystem responses to decreased loads of atmospheric pollutants.

  14. Physiological demands of women's rugby union: time-motion analysis and heart rate response.

    PubMed

    Virr, Jody Lynn; Game, Alex; Bell, Gordon John; Syrotuik, Daniel

    2014-01-01

    The aim of this study was to determine the physical demands of women's rugby union match play using time-motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18-34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women's rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands.

  15. Controlling false positive rates in mass-multivariate tests for electromagnetic responses

    PubMed Central

    Barnes, Gareth R.; Litvak, Vladimir; Brookes, Matt J.; Friston, Karl J.

    2011-01-01

    We address the problem of controlling false positive rates in mass-multivariate tests for electromagnetic responses in compact regions of source space. We show that mass-univariate thresholds based on sensor level multivariate thresholds (approximated using Roy's union–intersection principle) are unduly conservative. We then consider a Bonferroni correction for source level tests based on the number of unique lead-field extrema. For a given source space, the sensor indices corresponding to the maxima and minima (for each dipolar lead field) are listed, and the number of unique extrema is given by the number of unique pairs in this list. Using a multivariate beamformer formulation, we validate this heuristic against empirical permutation thresholds for mass-univariate and mass-multivariate tests (of induced and evoked responses) for a variety of source spaces, using simulated and real data. We also show that the same approximations hold when dealing with a cortical manifold (rather than a volume) and for mass-multivariate minimum norm solutions. We demonstrate that the mass-multivariate framework is not restricted to tests on a single contrast of effects (cf, Roy's maximum root) but also accommodates multivariate effects (cf, Wilk's lambda). PMID:21396458

  16. A radiotelemetry system for analyzing heart rate responses during playback experiments in blackbirds (Turdus merula ).

    PubMed

    Diehl, P; Helb, H W; Koch, U T; Lösch, M

    1986-12-01

    In acoustical stimulus-response tests on European blackbirds (Turdus merula ) in cages and an outdoor aviary, alteration in heart rate (HR) was used to measure reaction strenght. HR was measured by radiotelemetry. The miniature transmitters newly developed for this task had to fulfill the following requirements: Simultaneous recordings of HR in several interacting animals; uninterrupted transmission of HR signals, sufficient range and battery life combined with low weight and easy handling properties. The miniature transmitters successfully used in this experiment had a quartz-stabilized oscillator. They weighed between 4.1 and 5.2 g and had a range of 3 m and a lifetime of 72 hrs (circuit diagram, Fig.1). The transmitted signal corresponded to a unitary impulse representing the S-wave of the ECG (Fig. 4b). Implanted electrodes were used to record ECG potentials. The transmitter was carried by the birds like a small rucksack tied to their backs. Electrode implantation and transmitter installation are described in detail. HR signals stored on audio tape were later transformed to frequency curves on a chart recorder (Fig. 3, 4a). Typical HR response curves are shown (Fig. 5). Statistical analysis of the data was performed on a DEC-PDP-11 computer using a special set of programs. The system has been successfully used to provide answers to experimental questions not previously obtainable with classical methods.

  17. Cineradiographic Analysis of Mouse Postural Response to Alteration of Gravity and Jerk (Gravity Deceleration Rate)

    PubMed Central

    Hasegawa, Katsuya; de Campos, Priscila S.; Zeredo, Jorge L.; Kumei, Yasuhiro

    2014-01-01

    The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6) were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (<0.001 g). Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of −0.3~−0.4 j (g/s) induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk. PMID:25370191

  18. Controlling false positive rates in mass-multivariate tests for electromagnetic responses.

    PubMed

    Barnes, Gareth R; Litvak, Vladimir; Brookes, Matt J; Friston, Karl J

    2011-06-01

    We address the problem of controlling false positive rates in mass-multivariate tests for electromagnetic responses in compact regions of source space. We show that mass-univariate thresholds based on sensor level multivariate thresholds (approximated using Roy's union-intersection principle) are unduly conservative. We then consider a Bonferroni correction for source level tests based on the number of unique lead-field extrema. For a given source space, the sensor indices corresponding to the maxima and minima (for each dipolar lead field) are listed, and the number of unique extrema is given by the number of unique pairs in this list. Using a multivariate beamformer formulation, we validate this heuristic against empirical permutation thresholds for mass-univariate and mass-multivariate tests (of induced and evoked responses) for a variety of source spaces, using simulated and real data. We also show that the same approximations hold when dealing with a cortical manifold (rather than a volume) and for mass-multivariate minimum norm solutions. We demonstrate that the mass-multivariate framework is not restricted to tests on a single contrast of effects (cf, Roy's maximum root) but also accommodates multivariate effects (cf, Wilk's lambda).

  19. Physiological demands of women's rugby union: time-motion analysis and heart rate response.

    PubMed

    Virr, Jody Lynn; Game, Alex; Bell, Gordon John; Syrotuik, Daniel

    2014-01-01

    The aim of this study was to determine the physical demands of women's rugby union match play using time-motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18-34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women's rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands. PMID:24168428

  20. Cellular response to high pulse repetition rate nanosecond pulses varies with fluorescent marker identity.

    PubMed

    Steelman, Zachary A; Tolstykh, Gleb P; Beier, Hope T; Ibey, Bennett L

    2016-09-23

    Nanosecond electric pulses (nsEP's) are a well-studied phenomena in biophysics that cause substantial alterations to cellular membrane dynamics, internal biochemistry, and cytoskeletal structure, and induce apoptotic and necrotic cell death. While several studies have attempted to measure the effects of multiple nanosecond pulses, the effect of pulse repetition rate (PRR) has received little attention, especially at frequencies greater than 100 Hz. In this study, uptake of Propidium Iodide, FM 1-43, and YO-PRO-1 fluorescent dyes in CHO-K1 cells was monitored across a wide range of PRRs (5 Hz-500 KHz) using a laser-scanning confocal microscope in order to better understand how high frequency repetition rates impact induced biophysical changes. We show that frequency trends depend on the identity of the dye under study, which could implicate transmembrane protein channels in the uptake response due to their chemical selectivity. Finally, YO-PRO-1 fluorescence was monitored in the presence of Gadolinium (Gd(3+)), Ruthenium Red, and in calcium-free solution to elucidate a mechanism for its unique frequency trend. PMID:27553279

  1. Stochastic optimization for modeling physiological time series: application to the heart rate response to exercise

    NASA Astrophysics Data System (ADS)

    Zakynthinaki, M. S.; Stirling, J. R.

    2007-01-01

    Stochastic optimization is applied to the problem of optimizing the fit of a model to the time series of raw physiological (heart rate) data. The physiological response to exercise has been recently modeled as a dynamical system. Fitting the model to a set of raw physiological time series data is, however, not a trivial task. For this reason and in order to calculate the optimal values of the parameters of the model, the present study implements the powerful stochastic optimization method ALOPEX IV, an algorithm that has been proven to be fast, effective and easy to implement. The optimal parameters of the model, calculated by the optimization method for the particular athlete, are very important as they characterize the athlete's current condition. The present study applies the ALOPEX IV stochastic optimization to the modeling of a set of heart rate time series data corresponding to different exercises of constant intensity. An analysis of the optimization algorithm, together with an analytic proof of its convergence (in the absence of noise), is also presented.

  2. Studies on the codling moth (Lepidoptera: Tortricidae) response to different codlemone release rates.

    PubMed

    Vacas, S; Miñarro, M; Bosch, M D; Primo, J; Navarro-Llopis, V

    2013-12-01

    The response of the codling moth (Cydia pomonella L. (Lepidoptera: Tortricidae)) to different emission values of its main pheromone component, 8E,10E-dodecadien-1-ol (codlemone), was investigated in three field trials conducted in plots without mating disruption treatments. Moth catches obtained in traps baited with pheromone dispensers were correlated with the corresponding codlemone release rates by multiple regression analysis. In a preliminary trial conducted in Lleida (NE Spain), a decreasing trend of captures was observed based on increasing pheromone levels. After this, the pheromone release profiles of the pheromone dispensers were studied, in parallel with the field trials, by residual codlemone extraction and gas chromatography quantification. In the trials carried out in Asturias (NW Spain), a correlation between trap catches and emission levels (within the range from 11 to 1,078 μg/d) was found and fitted a logarithmic model. Captures followed a decreasing linear trend in the range of emission rates from 11 to 134 μg/d. Given that release values comprised between 11 and 67 μg/d did not lead to significantly different catches in traps, this emission range could be considered to develop effective formulations for attraction purposes when mating disruption is not acting in the environment.

  3. The divergent ventilatory and heart rate response to moderate hypercapnia in infants with apnoea of infancy

    PubMed Central

    Katz-Salamon, M.; Milerad, J.

    1998-01-01

    BACKGROUND—Inspired CO2 is a potent ventilatory stimulant exhibiting a paradoxical inhibitory effect on breathing at high concentrations. Severe respiratory depression as a result of CO2 rebreathing during sleep has been implicated as a possible trigger factor in sudden infant death syndrome (SIDS).
OBJECTIVE—To investigate the ventilatory and heart rate (HR) responses to inhaled CO2 in infants with apnoea of infancy, a group believed to be at increased risk of SIDS.
STUDY DESIGN—Thirty one infants with severe sleep related apnoea, 31 infants with mild recurrent apnoea, and 31 age and sex matched controls for the infants with severe sleep related apnoea were studied. HR was computed from digitised RR intervals, "ventilation" was recorded by inductance plethysmography, and PCO2 and PO2 were monitored by transcutaneous electrodes. The ventilatory and HR responses to CO2 were expressed as percentage increase in ventilation and change in HR/unit change in transcutaneous PCO2.
RESULTS—The mean increase in transcutaneous PCO2 during CO2 challenge (0.45 kPa = 3.4 mm Hg) resulted in a mean increase in ventilation of 291%/1 kPa (7.3 mm Hg) increase in transcutaneous PCO2, with no difference between the groups. A significant difference between infants with severe sleep related apnoea and mild recurrent apnoea versus controls (p < 0.02, p < 0.01, respectively) was found in their HR response to CO2 challenge: HR decreased in 12 severe sleep related apnoea infants and 10 infants with mild recurrent apnoea, but only in two controls.
CONCLUSION—Infants with apnoea of infancy frequently show a paradoxical decrease in HR during CO2 challenge, possibly because of an insufficient ability to mobilise cardiovascular defence mechanisms when challenged with hypercapnia.

 PMID:9875018

  4. Complete Firing-Rate Response of Neurons with Complex Intrinsic Dynamics.

    PubMed

    Puelma Touzel, Maximilian; Wolf, Fred

    2015-12-01

    The response of a neuronal population over a space of inputs depends on the intrinsic properties of its constituent neurons. Two main modes of single neuron dynamics-integration and resonance-have been distinguished. While resonator cell types exist in a variety of brain areas, few models incorporate this feature and fewer have investigated its effects. To understand better how a resonator's frequency preference emerges from its intrinsic dynamics and contributes to its local area's population firing rate dynamics, we analyze the dynamic gain of an analytically solvable two-degree of freedom neuron model. In the Fokker-Planck approach, the dynamic gain is intractable. The alternative Gauss-Rice approach lifts the resetting of the voltage after a spike. This allows us to derive a complete expression for the dynamic gain of a resonator neuron model in terms of a cascade of filters on the input. We find six distinct response types and use them to fully characterize the routes to resonance across all values of the relevant timescales. We find that resonance arises primarily due to slow adaptation with an intrinsic frequency acting to sharpen and adjust the location of the resonant peak. We determine the parameter regions for the existence of an intrinsic frequency and for subthreshold and spiking resonance, finding all possible intersections of the three. The expressions and analysis presented here provide an account of how intrinsic neuron dynamics shape dynamic population response properties and can facilitate the construction of an exact theory of correlations and stability of population activity in networks containing populations of resonator neurons. PMID:26720924

  5. Complete Firing-Rate Response of Neurons with Complex Intrinsic Dynamics

    PubMed Central

    Puelma Touzel, Maximilian; Wolf, Fred

    2015-01-01

    The response of a neuronal population over a space of inputs depends on the intrinsic properties of its constituent neurons. Two main modes of single neuron dynamics–integration and resonance–have been distinguished. While resonator cell types exist in a variety of brain areas, few models incorporate this feature and fewer have investigated its effects. To understand better how a resonator’s frequency preference emerges from its intrinsic dynamics and contributes to its local area’s population firing rate dynamics, we analyze the dynamic gain of an analytically solvable two-degree of freedom neuron model. In the Fokker-Planck approach, the dynamic gain is intractable. The alternative Gauss-Rice approach lifts the resetting of the voltage after a spike. This allows us to derive a complete expression for the dynamic gain of a resonator neuron model in terms of a cascade of filters on the input. We find six distinct response types and use them to fully characterize the routes to resonance across all values of the relevant timescales. We find that resonance arises primarily due to slow adaptation with an intrinsic frequency acting to sharpen and adjust the location of the resonant peak. We determine the parameter regions for the existence of an intrinsic frequency and for subthreshold and spiking resonance, finding all possible intersections of the three. The expressions and analysis presented here provide an account of how intrinsic neuron dynamics shape dynamic population response properties and can facilitate the construction of an exact theory of correlations and stability of population activity in networks containing populations of resonator neurons. PMID:26720924

  6. Heart Rate Response During Mission-Critical Tasks After Space Flight

    NASA Technical Reports Server (NTRS)

    Arzeno, Natalia M.; Lee, S. M. C.; Stenger, M. B.; Lawrence, E. L.; Platts, S. H.; Bloomberg, J. J.

    2010-01-01

    Adaptation to microgravity could impair crewmembers? ability to perform required tasks upon entry into a gravity environment, such as return to Earth, or during extraterrestrial exploration. Historically, data have been collected in a controlled testing environment, but it is unclear whether these physiologic measures result in changes in functional performance. NASA?s Functional Task Test (FTT) aims to investigate whether adaptation to microgravity increases physiologic stress and impairs performance during mission-critical tasks. PURPOSE: To determine whether the well-accepted postflight tachycardia observed during standard laboratory tests also would be observed during simulations of mission-critical tasks during and after recovery from short-duration spaceflight. METHODS: Five astronauts participated in the FTT 30 days before launch, on landing day, and 1, 6, and 30 days after landing. Mean heart rate (HR) was measured during 5 simulations of mission-critical tasks: rising from (1) a chair or (2) recumbent seated position followed by walking through an obstacle course (egress from a space vehicle), (3) translating graduated masses from one location to another (geological sample collection), (4) walking on a treadmill at 6.4 km/h (ambulation on planetary surface), and (5) climbing 40 steps on a passive treadmill ladder (ingress to lander). For tasks 1, 2, 3, and 5, astronauts were encouraged to complete the task as quickly as possible. Time to complete tasks and mean HR during each task were analyzed using repeated measures ANOVA and ANCOVA respectively, in which task duration was a covariate. RESULTS: Landing day HR was higher (P < 0.05) than preflight during the upright seat egress (7%+/-3), treadmill walk (13%+/-3) and ladder climb (10%+/-4), and HR remained elevated during the treadmill walk 1 day after landing. During tasks in which HR was not elevated on landing day, task duration was significantly greater on landing day (recumbent seat egress: 25

  7. Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole

    PubMed Central

    Pham, Vy P.; Luce, Andrea M.; Ruppelt, Sara C.; Wei, Wenjing; Aitken, Samuel L.; Musick, William L.; Roux, Ryan K.

    2015-01-01

    Consensus on the optimal treatment of Clostridium difficile infection (CDI) is rapidly changing. Treatment with metronidazole has been associated with increased clinical failure rates; however, the reasons for this are unclear. The purpose of this study was to assess age-related treatment response rates in hospitalized patients with CDI treated with metronidazole. This was a retrospective, multicenter cohort study of hospitalized patients with CDI. Patients were assessed for refractory CDI, defined as persistent diarrhea after 7 days of metronidazole therapy, and stratified by age and clinical characteristics. A total of 242 individuals, aged 60 ± 18 years (Charlson comorbidity index, 3.8 ± 2.4; Horn's index, 1.7 ± 1.0) were included. One hundred twenty-eight patients (53%) had severe CDI. Seventy patients (29%) had refractory CDI, a percentage that increased from 22% to 28% and to 37% for patients aged less than 50 years, for patients from 50 to 70 years, and for patients aged >70 years, respectively (P = 0.05). In multivariate analysis, Horn's index (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.50 to 2.77; P < 0.001), severe CDI (OR, 2.25; 95% CI, 1.15 to 4.41; P = 0.018), and continued use of antibiotics (OR, 2.65; 95% CI, 1.30 to 5.39; P = 0.0072) were identified as significant predictors of refractory CDI. Age was not identified as an independent risk factor for refractory CDI. Therefore, hospitalized elderly patients with CDI treated with metronidazole had increased refractory CDI rates likely due to increased underlying severity of illness, severity of CDI, and concomitant antibiotic use. These results may help identify patients that may benefit from alternative C. difficile treatments other than metronidazole. PMID:26195522

  8. "Does replication groups scoring reduce false positive rate in SNP interaction discovery?: Response"

    PubMed Central

    2010-01-01

    A response to Toplak et al: Does replication groups scoring reduce false positive rate in SNP interaction discovery? BMC Genomics 2010, 11:58. Background The genomewide evaluation of genetic epistasis is a computationally demanding task, and a current challenge in Genetics. HFCC (Hypothesis-Free Clinical Cloning) is one of the methods that have been suggested for genomewide epistasis analysis. In order to perform an exhaustive search of epistasis, HFCC has implemented several tools and data filters, such as the use of multiple replication groups, and direction of effect and control filters. A recent article has claimed that the use of multiple replication groups (as implemented in HFCC) does not reduce the false positive rate, and we hereby try to clarify these issues. Results/Discussion HFCC uses, as an analysis strategy, the possibility of replicating findings in multiple replication groups, in order to select a liberal subset of preliminary results that are above a statistical criterion and consistent in direction of effect. We show that the use of replication groups and the direction filter reduces the false positive rate of a study, although at the expense of lowering the overall power of the study. A post-hoc analysis of these selected signals in the combined sample could then be performed to select the most promising results. Conclusion Replication of results in independent samples is generally used in scientific studies to establish credibility in a finding. Nonetheless, the combined analysis of several datasets is known to be a preferable and more powerful strategy for the selection of top signals. HFCC is a flexible and complete analysis tool, and one of its analysis options combines these two strategies: A preliminary multiple replication group analysis to eliminate inconsistent false positive results, and a post-hoc combined-group analysis to select the top signals. PMID:20576100

  9. Trade-offs in traditional criteria vs environmental acceptability in product development: an example of the drilling fluids industry's response to environmental regulations

    SciTech Connect

    Jones, M.; Collins, C.; Havis, D.

    1980-01-01

    The coevolution of increased energy needs and a heightened environmental awareness within the past decade has been fraught with direct conflicts. Often, these conflicts were necessary to solidify boad policy acts or challenge nebulous or unclear regulations. The drilling fluids industry, a vital part of petroleum exploration and production, has recognized the need for avoiding future conflicts and for insuring the conservation of our environment. This recognition is best witnessed by the production of new products or the alteration of established products to eliminate or minimize environmental impact. As an example, biocides used by the industry to preserve drilling fluids and control microbiological problems have been under close scrutinization by the Environmental Protection Agency, the United States Geological Service, and the National Marine Fisheries Service. The need to develop new products in this area or substitute the active ingredients of established products is evident. Data are presented on 19 active ingredients under consideration by IMCO Services. Of the 19, three failed performance tests. An additional seven were dismissed because of environmental concerns even though all passed performace testing. Of the nine remaining, four were selected because of their optimal combination of performance and environmental acceptability. The final choice appeared acceptable in both categories and was economically competitive. By careful consideration of applicable regulations, it is intended that future conflicts over use and disposal of this product will be minimzed.

  10. Oxygen consumption and heart rate responses to isolated ballet exercise sets.

    PubMed

    Rodrigues-Krause, Josianne; Dos Santos Cunha, Giovani; Alberton, Cristine Lima; Follmer, Bruno; Krause, Mauricio; Reischak-Oliveira, Alvaro

    2014-01-01

    Ballet stage performances are associated with higher cardiorespiratory demand than rehearsals and classes. Hence, new interest is emerging to create periodized training that enhances dancers' fitness while minimizing delayed exercise-induced fatigue and possible injuries. Finding out in what zones of intensity dancers work during different ballet movements may support the use of supplemental training adjusted to the needs of the individual dancer. Therefore, the main purpose of this study was to describe dancers' oxygen consumption (VO2) and heart rate (HR) responses during the performance of nine isolated ballet exercise sets, as correlated with their first and second ventilatory thresholds (VT1 and VT2). Twelve female ballet dancers volunteered for the study. Their maximum oxygen consumption (VO2max), VT1, and VT2 were determined by use of an incremental treadmill test. Nine sets of ballet movements were assessed: pliés, tendus, jetés, rond de jambes, fondus, grand adage (adage), grand battements, temps levés, and sautés. The sets were randomly executed and separated by 5 minute rest periods. ANOVA for repeated measurements followed by the Bonferroni Post-hoc test were applied (p < 0.05). VO2 responses were as follows: pliés (17.6 ± 1.6 ml·kg(-1)·min(-1)); tendus and adage were not significantly greater than VT1; rond de jambes (21.8 ± 3.1 ml·kg(-1) ·min(-1)); fondus and jetés were higher than VT1 and the previous exercises; grand battements (25.8 ± 2.9 ml·kg(-1)·min(-1)) was greater than all the other exercises and VT1; and VT2 was significantly higher than all ballet sets. This stratification followed closely, but not exactly, the variation in HR. For example, rond de jambes (156.8 ± 19 b·min(-1)) did not show any significant difference from all the other ballet sets, nor VT1 or VT2. It is concluded that the workloads of isolated ballet sets, based on VO2 responses, vary between low and moderate aerobic intensity in relation to dancers' VT1 and

  11. Transient responses of the CSIRO climate model to two different rates of CO2 increase

    NASA Astrophysics Data System (ADS)

    Cai, W.; Gordon, H. B.

    The responses of the CSIRO coupled atmosphere-ocean-sea ice model to two greenhouse gas induced warming scenarios are described and compared to a control run with the current CO2 level. In one scenario, denoted IS92a, the atmospheric CO2 increases such that it reaches doubling after 128 years. In the other, the CO2 increases at 1% per year compounding (doubling after 70 y). As the CO2 increases in both scenarios, the top-of-atmosphere outgoing longwave radiation increases giving enhanced cooling of the coupled system, while the outgoing short wave radiation decreases contributing to a warming of the system. The latter overcompensates the former leading to a global mean net radiative heat gain. The distribution of this heat gain produces the well-known interhemispheric asymmetry in warming, despite a decrease in the sea ice around Antarctica in this model. It is found that the volume mean temperature response over the southern ocean is greater than that over the northern hemispheric oceans, and a maximum warming takes place at the subsurface rather at the surface of the ocean in the southern mid-to-high latitude region. The enhanced high-latitude freshening associated with the strengthened hydrological cycle significantly affects the latitudinal distribution of warming and other responses. It enhances the warming immediately equatorward of the deep water formation regions while produces a reduced warming, even a cooling, in these regions. In both runs, there is a decrease in the large-scale oceanic currents which have a significant thermohaline-driven component. The reduction in these currents reduces the poleward transport of salt out of the tropical and subtropical regions of these oceans. This and the enhanced evaporation contribute to considerable increases in surface salinity in the tropical and subtropical regions. In IS92a, the warming rate before doubling is smaller than that in 1% scenario, but the cumulative effects of the two experiments at the time of

  12. Change in the Growth Rate of Localized Pancreatic Adenocarcinoma in Response to Gemcitabine, Bevacizumab, and Radiation Therapy on MDCT

    SciTech Connect

    Rezai, Pedram; Yaghmai, Vahid; Tochetto, Sandra M.; Galizia, Mauricio S.; Miller, Frank H.; Mulcahy, Mary F.; Small, William

    2011-10-01

    Purpose: To depict treatment response to chemoradiotherapy by comparing tumor growth rate between treated and untreated patients and to compare depicted response with objective response according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 guideline. Methods and Materials: This Health Insurance Portability and Accountability Act-compliant, retrospective study was approved by the institutional review board. Volume doubling time (DT) of histologically confirmed locally advanced pancreatic adenocarcinoma was calculated in 16 patients treated with chemoradiotherapy and 10 untreated patients by incorporating interscan interval ({Delta}t) and tumor volume at baseline (V0) and follow-up (V1) obtained by semiautomated segmentation into the following equation: DT = {Delta}t . log 2/log (V1/V0). Reciprocal of doubling time (RDT), which is the linear representation of tumor growth rate, was calculated by use of the following equation: RDT = 365/DT. The lowest RDT value of 2.42 in untreated patients was considered as the cutoff value for depiction of treatment response. Depicted response rate was defined as the proportion of patients with an RDT value of less than 2.42. Depicted response was compared with objective response according to the RECIST 1.1 guideline. The significance level was set at p < 0.05. Results: There was a significant difference in mean RDT between treated (range, -7.12 to 3.27; mean, -1.27; median, -1.30) and untreated (range, 2.42 to 10.74; mean, 5.33; median, 4.26) patients (p < 0.05). Reciprocal of doubling time was less than 2.42 in 14 treated patients, which corresponded to a depicted response rate of 87.50% as opposed to the objective response rate of 18.75% according to the RECIST 1.1 guideline (p < 0.05) and carbohydrate antigen 19-9 response rate of 62.50% (p > 0.05). Carbohydrate antigen 19-9 response was concordant with RDT and RECIST response in 12 patients (75.00%) ({kappa}, 0.38) and 9 patients (56.25%) ({kappa}, 0

  13. A Comparison of Model-Data Fit for Parametric and Nonparametric Item Response Theory Models Using Ordinal-Level Ratings

    ERIC Educational Resources Information Center

    Dyehouse, Melissa A.

    2009-01-01

    This study compared the model-data fit of a parametric item response theory (PIRT) model to a nonparametric item response theory (NIRT) model to determine the best-fitting model for use with ordinal-level alternate assessment ratings. The PIRT Generalized Graded Unfolding Model (GGUM) was compared to the NIRT Mokken model. Chi-square statistics…

  14. Response Styles in Rating Scales: Simultaneous Modeling of Content-Related Effects and the Tendency to Middle or Extreme Categories

    ERIC Educational Resources Information Center

    Tutz, Gerhard; Berger, Moritz

    2016-01-01

    Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

  15. The Effects of Delivery Mode upon Survey Response Rate and Perceived Attitudes of Texas Agri-Science Teachers.

    ERIC Educational Resources Information Center

    Fraze, Steve D.; Hardin, Kelly K.; Brashears, M. Todd; Haygood, Jacqui L.; Smith, James H.

    2003-01-01

    Random samples of agriscience teachers completed surveys via electronic mail (26 of 95), the Web (41 of 95), and paper (57 of 95). Paper yielded a 60% response, Web 43%, and e-mail 27%, with significant differences in time to respond. Age and teaching experience did not affect response rate. The e-mail survey may have been affected by formatting…

  16. Sonic boom acceptability studies

    NASA Astrophysics Data System (ADS)

    Shepherd, Kevin P.; Sullivan, Brenda M.; Leatherwood, Jack D.; McCurdy, David A.

    1992-04-01

    The determination of the magnitude of sonic boom exposure which would be acceptable to the general population requires, as a starting point, a method to assess and compare individual sonic booms. There is no consensus within the scientific and regulatory communities regarding an appropriate sonic boom assessment metric. Loudness, being a fundamental and well-understood attribute of human hearing was chosen as a means of comparing sonic booms of differing shapes and amplitudes. The figure illustrates the basic steps which yield a calculated value of loudness. Based upon the aircraft configuration and its operating conditions, the sonic boom pressure signature which reaches the ground is calculated. This pressure-time history is transformed to the frequency domain and converted into a one-third octave band spectrum. The essence of the loudness method is to account for the frequency response and integration characteristics of the auditory system. The result of the calculation procedure is a numerical description (perceived level, dB) which represents the loudness of the sonic boom waveform.

  17. Sonic boom acceptability studies

    NASA Technical Reports Server (NTRS)

    Shepherd, Kevin P.; Sullivan, Brenda M.; Leatherwood, Jack D.; Mccurdy, David A.

    1992-01-01

    The determination of the magnitude of sonic boom exposure which would be acceptable to the general population requires, as a starting point, a method to assess and compare individual sonic booms. There is no consensus within the scientific and regulatory communities regarding an appropriate sonic boom assessment metric. Loudness, being a fundamental and well-understood attribute of human hearing was chosen as a means of comparing sonic booms of differing shapes and amplitudes. The figure illustrates the basic steps which yield a calculated value of loudness. Based upon the aircraft configuration and its operating conditions, the sonic boom pressure signature which reaches the ground is calculated. This pressure-time history is transformed to the frequency domain and converted into a one-third octave band spectrum. The essence of the loudness method is to account for the frequency response and integration characteristics of the auditory system. The result of the calculation procedure is a numerical description (perceived level, dB) which represents the loudness of the sonic boom waveform.

  18. The Thernstrom Fallacy: Why Affirmative Action Is Not Responsible for High Dropout Rates of African American College Students.

    ERIC Educational Resources Information Center

    Cross, Theodore

    1998-01-01

    Critiques the theory advanced by A. Thernstrom and S. Thernstrom that affirmative action is responsible for the high college dropout rates of African Americans because underqualified applicants are admitted. The argument centers on examination of dropout rates at historically black colleges and institutions, where racial preference is not a…

  19. Heart Rate Profiles of Children with and without Autism Spectrum Disorder in Response to Physical Play: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Breslin, Casey M.; Rudisill, Mary E.; Wadsworth, Danielle W.

    2015-01-01

    In this study, the heart rate response of children with and without autism spectrum disorder (ASD) exposed to outdoor free play sessions during preschool was examined. Participants (n = 7; four children with ASD and three children who show typical development) wore Actiheart heart rate monitors during 6 school days. Using a single-subject design,…

  20. On the Primacy of Molecular Processes in Determining Response Rates under Variable-Ratio and Variable-Interval Schedules

    ERIC Educational Resources Information Center

    Tanno, Takayuki; Sakagami, Takayuki

    2008-01-01

    This study focused on variables that may account for response-rate differences under variable-ratio (VR) and variable-interval (VI) schedules of reinforcement. Four rats were exposed to VR, VI, tandem VI differential- reinforcement-of-high-rate, regulated-probability-interval, and negative-feedback schedules of reinforcement that provided the same…

  1. Use of Student Ratings to Benchmark Universities: Multilevel Modeling of Responses to the Australian Course Experience Questionnaire (CEQ)

    ERIC Educational Resources Information Center

    Marsh, Herbert W.; Ginns, Paul; Morin, Alexandre J. S.; Nagengast, Benjamin; Martin, Andrew J.

    2011-01-01

    Recently graduated university students from all Australian Universities rate their overall departmental and university experiences (DUEs), and their responses (N = 44,932, 41 institutions) are used by the government to benchmark departments and universities. We evaluate this DUE strategy of rating overall departments and universities rather than…

  2. The therapeutic effect of clinical trials: understanding placebo response rates in clinical trials – A secondary analysis

    PubMed Central

    Walach, Harald; Sadaghiani, Catarina; Dehm, Cornelia; Bierman, Dick

    2005-01-01

    Background and purpose Placebo response rates in clinical trials vary considerably and are observed frequently. For new drugs it can be difficult to prove effectiveness superior to placebo. It is unclear what contributes to improvement in the placebo groups. We wanted to clarify, what elements of clinical trials determine placebo variability. Methods We analysed a representative sample of 141 published long-term trials (randomized, double-blind, placebo-controlled; duration > 12 weeks) to find out what study characteristics predict placebo response rates in various diseases. Correlational and regression analyses with study characteristics and placebo response rates were carried out. Results We found a high and significant correlation between placebo and treatment response rate across diseases (r = .78; p < .001). A multiple regression model explained 79% of the variance in placebo variability (F = 59.7; p < 0.0001). Significant predictors are, among others, the duration of the study (beta = .31), the quality of the study (beta = .18), the fact whether a study is a prevention trial (beta = .44), whether dropouts have been documented (beta = -.20), or whether additional treatments have been documented (beta = -.17). Healing rates with placebo are lower in the following diagnoses; neoplasms (beta = -.21), nervous diseases (beta = -.10), substance abuse (beta = -.14). Without prevention trials the amount of variance explained is 42%. Conclusion Medication response rates and placebo response rates in clinical trials are highly correlated. Trial characteristics can explain some portion of the variance in placebo healing rates in RCTs. Placebo response in trials is only partially due to methodological artefacts and only partially dependent on the diagnoses treated. PMID:16109176

  3. Identification of anaerobic threshold using heart rate response during dynamic exercise.

    PubMed

    Marães, V R F S; Silva, E; Catai, A M; Novais, L D; Moura, M A S; Oliveira, L; Gallo Jr, L

    2005-05-01

    The objective of the present study was to characterize the heart rate (HR) patterns of healthy males using the autoregressive integrated moving average (ARIMA) model over a power range assumed to correspond to the anaerobic threshold (AT) during discontinuous dynamic exercise tests (DDET). Nine young (22.3 +/- 1.57 years) and 9 middle-aged (MA) volunteers (43.2 +/- 3.53 years) performed three DDET on a cycle ergometer. Protocol I: DDET in steps with progressive power increases of 10 W; protocol II: DDET using the same power values as protocol 1, but applied randomly; protocol III: continuous dynamic exercise protocol with ventilatory and metabolic measurements (10 W/min ramp power), for the measurement of ventilatory AT. HR was recorded and stored beat-to-beat during DDET, and analyzed using the ARIMA (protocols I and II). The DDET experiments showed that the median physical exercise workloads at which AT occurred were similar for protocols I and II, i.e., AT occurred between 75 W (116 bpm) and 85 W (116 bpm) for the young group and between 60 W (96 bpm) and 75 W (107 bpm) for group MA in protocols I and II, respectively; in two MA volunteers the ventilatory AT occurred at 90 W (108 bpm) and 95 W (111 bpm). This corresponded to the same power values of the positive trend in HR responses. The change in HR response using ARIMA models at submaximal dynamic exercise powers proved to be a promising approach for detecting AT in normal volunteers.

  4. Heart rate and core temperature responses of elite pit crews during automobile races.

    PubMed

    Ferguson, David P; Bowen, Robert S; Lightfoot, J Timothy

    2011-08-01

    There is limited information regarding the physiological and psychological demands of the racing environment, and the subsequent effect on the performance of pit crew athletes. The purpose of this study was to evaluate heart rates (HRs) and core body temperatures (CTs) of pit crew athletes in the race environment. The HR and CT of pit crew athletes (n = 7) and control subjects were measured during 6 National Association for Stock Car Automobile Racing Sprint Cup races using ingestible sensors (HQ Inc, Palmetto, FL, USA). The HR and CT were measured before each race, at 15-minute intervals during the race, and upon completion of each pit stop. Compared to the control subject at each race, the pit crew athletes had significantly (p = 0.014) lower core temperatures (CTs). The pit crew athletes displayed higher HRs on the asphalt tracks than on concrete tracks (p = 0.011), and HR responses of the crew members were significantly (p = 0.012) different between pit crew positions, with the tire changers and jackman exhibiting higher HRs than the tire carriers. Unexpectedly, the CTs of the pit crew athletes were not elevated in the race environment, despite high ambient temperatures and the extensive fire-protection equipment (e.g., helmet, suit, gloves) each pit crew athlete wore. The lack of CT change is possibly the result of the increased HR more efficiently shunting blood to the skin and dissipating heat as a consequence of the athletes' extensive training regimen and ensuing heat acclimation. Additionally, it is possible that psychological stress unique to several of the tracks provided an additive effect resulting in increased heart rates.

  5. Irregular Speech Rate Dissociates Auditory Cortical Entrainment, Evoked Responses, and Frontal Alpha

    PubMed Central

    Kayser, Stephanie J.; Ince, Robin A.A.; Gross, Joachim

    2015-01-01

    The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered to be a central mechanism underlying auditory perception. Previous work has shown that entrainment is reduced when the quality of the acoustic input is degraded, but has also linked rhythmic activity at similar time scales to the encoding of temporal expectations. To understand these bottom-up and top-down contributions to rhythmic entrainment, we manipulated the temporal predictive structure of speech by parametrically altering the distribution of pauses between syllables or words, thereby rendering the local speech rate irregular while preserving intelligibility and the envelope fluctuations of the acoustic signal. Recording EEG activity in human participants, we found that this manipulation did not alter neural processes reflecting the encoding of individual sound transients, such as evoked potentials. However, the manipulation significantly reduced the fidelity of auditory delta (but not theta) band entrainment to the speech envelope. It also reduced left frontal alpha power and this alpha reduction was predictive of the reduced delta entrainment across participants. Our results show that rhythmic auditory entrainment in delta and theta bands reflect functionally distinct processes. Furthermore, they reveal that delta entrainment is under top-down control and likely reflects prefrontal processes that are sensitive to acoustical regularities rather than the bottom-up encoding of acoustic features. SIGNIFICANCE STATEMENT The entrainment of rhythmic auditory cortical activity to the speech envelope is considered to be critical for hearing. Previous work has proposed divergent views in which entrainment reflects either early evoked responses related to sound encoding or high-level processes related to expectation or cognitive selection. Using a manipulation of speech rate, we dissociated auditory entrainment at different time scales. Specifically, our

  6. The effects of heating rate on the dose response characteristics of TLD-200, TLD-300 and TLD-400

    NASA Astrophysics Data System (ADS)

    Kafadar, V. Emir; Necmeddin Yazici, A.; Güler Yildirim, R.

    2009-10-01

    In the given study; the effects of heating rates on the dose response characteristics of CaF 2:Dy (TLD-200), CaF 2:Tm (TLD-300) and CaF 2:Mn (TLD-400) crystals have been investigated using the dose dependence curve and dose response function f( D). It was observed from the dose response functions that the linearity and behaviour of the TL glow peaks of TLD-200 and TLD-400 are affected, but the TLD-300 is not affected from the heating rate.

  7. Acceptability of BCG vaccination.

    PubMed

    Mande, R

    1977-01-01

    The acceptability of BCG vaccination varies a great deal according to the country and to the period when the vaccine is given. The incidence of complications has not always a direct influence on this acceptability, which depends, for a very large part, on the risk of tuberculosis in a given country at a given time.

  8. ATLAS ACCEPTANCE TEST

    SciTech Connect

    Cochrane, J. C. , Jr.; Parker, J. V.; Hinckley, W. B.; Hosack, K. W.; Mills, D.; Parsons, W. M.; Scudder, D. W.; Stokes, J. L.; Tabaka, L. J.; Thompson, M. C.; Wysocki, Frederick Joseph; Campbell, T. N.; Lancaster, D. L.; Tom, C. Y.

    2001-01-01

    The acceptance test program for Atlas, a 23 MJ pulsed power facility for use in the Los Alamos High Energy Density Hydrodynamics program, has been completed. Completion of this program officially releases Atlas from the construction phase and readies it for experiments. Details of the acceptance test program results and of machine capabilities for experiments will be presented.

  9. Effect of different body-exercise modes on the rate response of the temperature-controlled pacemaker Nova MR.

    PubMed

    Zegelman, M; Winter, U J; Alt, E; Treese, N; Kreuzer, J; Henry, L; Mugica, J; Schroeder, E; Klein, H; Völker, R

    1990-06-01

    In order to evaluate the effect of different modes of physical exercise on the rate response of the temperature-controlled Nova MR, parameters such as temperature behaviour and correlation of work load to pacing rate were investigated using different types and protocols of stress testing. This study considered 21 patients (age: 66 +/- 12 y). The indications for the Nova MR were AV block (n: 14) and sick sinus syndrome (n: 7). The patients performed two different types of exercise (treadmill n: 13, bicycle n: 14) based on different protocols. We registered the surface ECG, pacing rate, exercise time, and (via data transmission by the RX 2000 programmer) blood temperature and pacing rate. An adequate rate response could be achieved with all the different types of exercise and protocols using more sensitive program settings. The type of stress testing used to adjust or evaluate the Nova MR seems to be secondary, although cycling as compared with treadmill exercise resulted in a slightly weakened reaction of temperature and pacing rate. Our investigations revealed a good correlation between work load and pacing rate independent of the type of stress testing. The initial DIP (48%) is not a constant phenomenon and showed inter- and intraindividual variations. Impressive psychological influences also exhibited an effect on temperature and pacing rate, sometimes preventing a DIP response. During exercise at lower work loads (under 50 watts, shorter than 3-4 min) the rate response of the Nova MR--without any detected DIP--is often delayed due either to a decrease or to a late and flat increase in temperature. An additional fast-reacting sensor could be advantageous in triggering the initial rate response in such cases.

  10. Estimation of oxygen uptake from heart rate response to undersea work.

    PubMed

    Dwyer, J

    1983-06-01

    The efficacy of using a diver's heart rate (HR) response to work performed formed in the open sea to estimate the oxygen uptake (VO2) and work stress by general and depth-specific regression equations was examined in six scuba divers. A diver-carried data recording system and an underwater gas sampler were used to obtain measures of physiological responses to work in the ocean. The HR and VO2 were measured during dry cycling at 1 ATA, and during moderate to very heavy work fin-swimming against an ergometer at 2, 3, and 4 ATA. Underwater VO2 and HR at 2-4 ATA ranged from 1.41 to 3.89 liters/min (39%-89% VO2max observed on land) and 105-180 beats/min, respectively. Individual data points at three work levels at 1-4 ATA were used to compute correlation coefficients (r) and regression equations. Only one significant difference in regression slopes was found (1 ATA vs. 4 ATA), but large differences in intercept were observed in each comparison. From 1 ATA to 4 ATA r decreased from 0.78 to 0.53 while the standard error of VO2 estimated from HR (Syx) increased from 0.229 to 0.582 liters O2. The regression equation for dry exercise (1 ATA) underestimated VO2 over most of the work range by 0.4 to 0.9 liters/min or 11% to 25% of VO2max. The accuracy of estimating VO2 from cardiac response by general (1 ATA) or depth-specific regression equations is insufficient to justify their use in research or diver monitoring systems. Attempts to estimate VO2 from pulmonary ventilation (VE) gave similar results with more differences between slopes among the conditions. These observations and those of other investigators support the idea that underwater work loads and stress cannot be estimated or evaluated by simple HR measurements that are made during diving operations and interpreted in terms of sea-level standards.

  11. Acceptability of blood and blood substitutes.

    PubMed

    Ferguson, E; Prowse, C; Townsend, E; Spence, A; Hilten, J A van; Lowe, K

    2008-03-01

    Alternatives to donor blood have been developed in part to meet increasing demand. However, new biotechnologies are often associated with increased perceptions of risk and low acceptance. This paper reviews developments of alternatives and presents data, from a field-based experiment in the UK and Holland, on the risks and acceptance of donor blood and alternatives (chemical, genetically modified and bovine). UK groups perceived all substitutes as riskier than the Dutch. There is a negative association between perceived risk and acceptability. Solutions to increasing acceptance are discussed in terms of implicit attitudes, product naming and emotional responses.

  12. Poster — Thur Eve — 27: Flattening Filter Free VMAT Quality Assurance: Dose Rate Considerations for Detector Response

    SciTech Connect

    Viel, Francis; Duzenli, Cheryl; Camborde, Marie-Laure; Strgar, Vincent; Horwood, Ron; Atwal, Parmveer; Gete, Ermias; Karan, Tania

    2014-08-15

    Introduction: Radiation detector responses can be affected by dose rate. Due to higher dose per pulse and wider range of mu rates in FFF beams, detector responses should be characterized prior to implementation of QA protocols for FFF beams. During VMAT delivery, the MU rate may also vary dramatically within a treatment fraction. This study looks at the dose per pulse variation throughout a 3D volume for typical VMAT plans and the response characteristics for a variety of detectors, and makes recommendations on the design of QA protocols for FFF VMAT QA. Materials and Methods: Linac log file data and a simplified dose calculation algorithm are used to calculate dose per pulse for a variety of clinical VMAT plans, on a voxel by voxel basis, as a function of time in a cylindrical phantom. Diode and ion chamber array responses are characterized over the relevant range of dose per pulse and dose rate. Results: Dose per pulse ranges from <0.1 mGy/pulse to 1.5 mGy/pulse in a typical VMAT treatment delivery using the 10XFFF beam. Diode detector arrays demonstrate increased sensitivity to dose (+./− 3%) with increasing dose per pulse over this range. Ion chamber arrays demonstrate decreased sensitivity to dose (+/− 1%) with increasing dose rate over this range. Conclusions: QA protocols should be designed taking into consideration inherent changes in detector sensitivity with dose rate. Neglecting to account for changes in detector response with dose per pulse can lead to skewed QA results.

  13. Laser-based irradiation apparatus and method to measure the functional dose-rate response of semiconductor devices

    DOEpatents

    Horn, Kevin M.

    2008-05-20

    A broad-beam laser irradiation apparatus can measure the parametric or functional response of a semiconductor device to exposure to dose-rate equivalent infrared laser light. Comparisons of dose-rate response from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems can determine if aging has affected the device's overall functionality. The dependence of these changes on equivalent dose-rate pulse intensity and/or duration can be measured with the apparatus. The synchronized introduction of external electrical transients into the device under test can be used to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure while exposing the device to dose-rate equivalent infrared laser light.

  14. Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes.

    PubMed

    Cornelissen, Johannes H C; van Bodegom, Peter M; Aerts, Rien; Callaghan, Terry V; van Logtestijn, Richard S P; Alatalo, Juha; Chapin, F Stuart; Gerdol, Renato; Gudmundsson, Jon; Gwynn-Jones, Dylan; Hartley, Anne E; Hik, David S; Hofgaard, Annika; Jónsdóttir, Ingibjörg S; Karlsson, Staffan; Klein, Julia A; Laundre, Jim; Magnusson, Borgthor; Michelsen, Anders; Molau, Ulf; Onipchenko, Vladimir G; Quested, Helen M; Sandvik, Sylvi M; Schmidt, Inger K; Shaver, Gus R; Solheim, Bjørn; Soudzilovskaia, Nadejda A; Stenström, Anna; Tolvanen, Anne; Totland, Ørjan; Wada, Naoya; Welker, Jeffrey M; Zhao, Xinquan

    2007-07-01

    Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide. Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.

  15. Physiological differences between burnout patients and healthy controls: blood pressure, heart rate, and cortisol responses

    PubMed Central

    De Vente, W; Olff, M; Van Amsterdam, J G C; Kamphuis, J; Emmelkamp, P

    2003-01-01

    Objectives: To investigate differences between burnout patients and healthy controls regarding basal physiological values and physiological stress responses. Measures of the sympathetic-adrenergic-medullary (SAM) axis and the hypothalamic-pituitary-adrenal (HPA) axis were examined. Methods: SAM axis and HPA axis activity was compared between 22 burnout patients and 23 healthy controls. SAM axis activity was measured by means of heart rate (HR) and blood pressure (BP). HPA axis activity was investigated by means of salivary cortisol levels. Resting levels of HR, BP, and cortisol were determined as well as reactivity and recovery of these measures during a laboratory session involving mental arithmetic and speech tasks. In addition, morning levels of cortisol were determined. Results: Burnout patients showed higher resting HR than healthy controls. BP resting values did not differ between burnout patients and healthy controls, nor did cardiovascular reactivity and recovery measurements during the laboratory session. Basal cortisol levels and cortisol reactivity and recovery measures were similar for burnout patients and healthy controls. However, burnout patients showed elevated cortisol levels during the first hour after awakening in comparison to healthy controls. Conclusions: The findings provided limited proof that SAM axis and HPA axis are disturbed among burnout patients. Elevated HR and elevated early morning cortisol levels may be indicative of sustained activation. PMID:12782748

  16. Contemporary phase III clinical trial endpoints in advanced ovarian cancer: assessing the pros and cons of objective response rate, progression-free survival, and overall survival.

    PubMed

    Tate Thigpen, J

    2015-01-01

    Among gynecologic cancers, ovarian cancer provides the greatest challenge because 75% to 80% of patients present with stage III/IV disease. Over the last 40 years, a series of large trials conducted by the Gynecologic Oncology Group and other cooperative groups has produced striking improvements in patient outcome; but the majority still dies of their disease. Further research in both the laboratory and the clinic is essential to continued improvement in patient management. Clinical trials, however, have become a major challenge because of issues with trial endpoints. Historically, overall survival (OS) has been regarded as the "gold standard" of endpoints. Lack of effective treatment for patients who progressed on or recurred after front-line therapy allowed trials to avoid obfuscation of OS by post-progression therapy. More recently, studies have identified over 20 agents active against ovarian cancer. Reasonable evidence shows that effective post-progression therapy with multiple lines of active agents can render the survival endpoint uninterpretable. Two other endpoints avoid this problem. The objective response rate, assessed by the Response Evaluation Criteria in Solid Tumors (RECIST), is an accepted endpoint for accelerated approval in ovarian cancer. More importantly, progression-free survival (PFS), measured from study entry to progression of disease, avoids post-progression therapy completely. Without effective post-progression therapy (prior to 1990), data show that PFS is a surrogate for OS. Recent experience with 4 large trials of bevacizumab shows that PFS can be accurately assessed if progression is clearly defined and if timing of assessments is consistent in all study arms. Acceptance of PFS as the optimal endpoint for ovarian cancer trials by investigators and regulatory agencies is crucial to further advances in management because effective post-progression therapy has rendered differences in OS virtually impossible to assess reliably.

  17. Treatment acceptability among mexican american parents.

    PubMed

    Borrego, Joaquin; Ibanez, Elizabeth S; Spendlove, Stuart J; Pemberton, Joy R

    2007-09-01

    There is a void in the literature with regard to Hispanic parents' views about common interventions for children with behavior problems. The purpose of this study was to examine the treatment acceptability of child management techniques in a Mexican American sample. Parents' acculturation was also examined to determine if it would account for differences in treatment acceptability. Mexican American parents found response cost, a punishment-based technique, more acceptable than positive reinforcement-based techniques (e.g., differential attention). Results suggest that Mexican American parents' acculturation has little impact on acceptability of child management interventions. No association was found between mothers' acculturation and treatment acceptability. However, more acculturated Mexican American fathers viewed token economy as more acceptable than less acculturated fathers. Results are discussed in the context of clinical work and research with Mexican Americans.

  18. The effect of stimulus repetition rate on the diagnostic efficacy of the auditory nerve-brain-stem evoked response.

    PubMed

    Freeman, S; Sohmer, H; Silver, S

    1991-04-01

    This study investigates the hypothesis that an increase in the click presentation rate during diagnostic testing with the auditory nerve-brain-stem response (ABR) will increase the efficiency with which lesions may be detected in the nervous system. Cats were exposed to conditions of hypoxia, hypercapnia and acidemia, and hypoglycemia was induced in rats. ABR was recorded using the standard 10/sec click rate and also a higher (55/sec) rate during both the control state and experimental state. Various parameters of the ABR were compared at the two click rates in the control and experimental states to see if the higher click rate was more effective in detecting pathology in the nervous system. It was found that in only a very few cases was the higher stimulus presentation rate more effective, and that in general ABR recordings at one stimulus rate only is quite sufficient for work in a clinical setting. PMID:1706249

  19. Quasi-Static and High Strain Rate Compressive Response of Injection-Molded Cenosphere/HDPE Syntactic Foam

    NASA Astrophysics Data System (ADS)

    Bharath Kumar, B. R.; Singh, Ashish Kumar; Doddamani, Mrityunjay; Luong, Dung D.; Gupta, Nikhil

    2016-07-01

    High strain rate compressive properties of high-density polyethylene (HDPE) matrix syntactic foams containing cenosphere filler are investigated. Thermoplastic matrix syntactic foams have not been studied extensively for high strain rate deformation response despite interest in them for lightweight underwater vehicle structures and consumer products. Quasi-static compression tests are conducted at 10-4 s-1, 10-3 s-1 and 10-2 s-1 strain rates. Further, a split-Hopkinson pressure bar is utilized for characterizing syntactic foams for high strain rate compression. The compressive strength of syntactic foams is higher than that of HDPE resin at the same strain rate. Yield strength shows an increasing trend with strain rate. The average yield strength values at high strain rates are almost twice the values obtained at 10-4 s-1 for HDPE resin and syntactic foams. Theoretical models are used to estimate the effectiveness of cenospheres in reinforcing syntactic foams.

  20. Maximizing measurement efficiency of behavior rating scales using Item Response Theory: An example with the Social Skills Improvement System - Teacher Rating Scale.

    PubMed

    Anthony, Christopher J; DiPerna, James C; Lei, Pui-Wa

    2016-04-01

    Measurement efficiency is an important consideration when developing behavior rating scales for use in research and practice. Although most published scales have been developed within a Classical Test Theory (CTT) framework, Item Response Theory (IRT) offers several advantages for developing scales that maximize measurement efficiency. The current study provides an example of using IRT to maximize rating scale efficiency with the Social Skills Improvement System - Teacher Rating Scale (SSIS - TRS), a measure of student social skills frequently used in practice and research. Based on IRT analyses, 27 items from the Social Skills subscales and 14 items from the Problem Behavior subscales of the SSIS - TRS were identified as maximally efficient. In addition to maintaining similar content coverage to the published version, these sets of maximally efficient items demonstrated similar psychometric properties to the published SSIS - TRS.

  1. Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

    SciTech Connect

    Scott, Bobby, R., Ph.D.

    2003-06-27

    applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low

  2. Who accepts first aid training?

    PubMed

    Pearn, J; Dawson, B; Leditschke, F; Petrie, G; Nixon, J

    1980-09-01

    The percentage of individuals trained in first aid skills in the general community is inadequate. We report here a study to investigate factors which influence motivation to accept voluntary training in first aid. A group of 700 randomly selected owners of inground swimming pools (a parental high-risk group) was offered a course of formal first aid instruction. Nine per cent attended the offered training course. The time commitment involved in traditional courses (eight training nights spread over four weeks) is not a deterrent, the same percentage accepting such courses as that who accept a course of one night's instruction. Cost is an important deterrent factor, consumer resistance rising over 15 cost units (one cost unit = the price of a loaf of bread). The level of competent first aid training within the community can be raised by (a) keeping to traditional course content, but (b) by ensuring a higher acceptance rate of first aid courses by a new approach to publicity campaigns, to convince prospective students of the real worth of first aid training. Questions concerning who should be taught first aid, and factors influencing motivation, are discussed.

  3. National survey of physicians to determine the effect of unconditional incentives on response rates of physician postal surveys

    PubMed Central

    Abdulaziz, Kasim; Brehaut, Jamie; Taljaard, Monica; Émond, Marcel; Sirois, Marie-Josée; Lee, Jacques S; Wilding, Laura; Perry, Jeffrey J

    2015-01-01

    Objectives Physicians are a commonly targeted group in health research surveys, but their response rates are often relatively low. The goal of this paper was to evaluate the effect of unconditional incentives in the form of a coffee card on physician postal survey response rates. Design Following 13 key informant interviews and eight cognitive interviews a survey questionnaire was developed. Participants A random sample of 534 physicians, stratified by physician group (geriatricians, family physicians, emergency physicians) was selected from a national medical directory. Setting Using computer generated random numbers; half of the physicians in each stratum were allocated to receive a coffee card to a popular national coffee chain together with the first survey mailout. Interventions The intervention was a $10 Tim Hortons gift card given to half of the physicians who were randomly allocated to receive the incentive. Results 265 (57.0%) physicians completed the survey. The response rate was significantly higher in the group allocated to receive the incentive (62.7% vs 51.3% in the control group; p=0.01). Conclusions Our results indicate that an unconditional incentive in the form of a coffee gift card can substantially improve physician response rates. Future research can look at the effect of varying amounts of cash on the gift cards on response rates. PMID:25694460

  4. Modelling temperature-compensated physiological rates, based on the co-ordination of responses to temperature of developmental processes.

    PubMed

    Parent, B; Turc, O; Gibon, Y; Stitt, M; Tardieu, F

    2010-05-01

    Temperature fluctuates rapidly and affects all developmental and metabolic processes. This often obscures the effects of developmental trends or of other environmental conditions when temperature fluctuates naturally. A method is proposed for modelling temperature-compensated rates, based on the coordination of temperature responses of developmental processes. In a data set comprising 41 experiments in the greenhouse, growth chamber, or the field, the temperature responses in the range of 6-36 degrees C for different processes were compared in three species, maize, rice, and Arabidopsis thaliana. Germination, cell division, expansive growth rate, leaf initiation, and phenology showed coordinated temperature responses and followed common laws within each species. The activities of 10 enzymes involved in carbon metabolism exhibited monotonous exponential responses across the whole range 10-40 degrees C. Hence, the temperature dependence of developmental processes is not explained by a simple relationship to central metabolism. Temperature-compensated rates of development were calculated from the equations of response curve, by expressing rates per unit equivalent time at 20 degrees C. This resulted in stable rates when temperatures fluctuated over a large range (for which classical thermal time was inefficient), and in time courses of leaf development which were common to several experiments with different temperature scenarios.

  5. Modelling temperature-compensated physiological rates, based on the co-ordination of responses to temperature of developmental processes.

    PubMed

    Parent, B; Turc, O; Gibon, Y; Stitt, M; Tardieu, F

    2010-05-01

    Temperature fluctuates rapidly and affects all developmental and metabolic processes. This often obscures the effects of developmental trends or of other environmental conditions when temperature fluctuates naturally. A method is proposed for modelling temperature-compensated rates, based on the coordination of temperature responses of developmental processes. In a data set comprising 41 experiments in the greenhouse, growth chamber, or the field, the temperature responses in the range of 6-36 degrees C for different processes were compared in three species, maize, rice, and Arabidopsis thaliana. Germination, cell division, expansive growth rate, leaf initiation, and phenology showed coordinated temperature responses and followed common laws within each species. The activities of 10 enzymes involved in carbon metabolism exhibited monotonous exponential responses across the whole range 10-40 degrees C. Hence, the temperature dependence of developmental processes is not explained by a simple relationship to central metabolism. Temperature-compensated rates of development were calculated from the equations of response curve, by expressing rates per unit equivalent time at 20 degrees C. This resulted in stable rates when temperatures fluctuated over a large range (for which classical thermal time was inefficient), and in time courses of leaf development which were common to several experiments with different temperature scenarios. PMID:20194927

  6. The need for dental ethicists and the promise of universal patient acceptance: response to Richard Masella's "Renewing professionalism in dental education".

    PubMed

    Patthoff, Donald E

    2007-02-01

    Richard Masella's "Renewing Professionalism in Dental Education: Overcoming the Market Environment" reveals why professionalism is nearly dead in America; it also shows the good of commerce and the excesses of commercialism in the market. More importantly, it collects and summarizes most of the relevant forms of education currently available to teach professionalism and professional ethics in dentistry; it then briefly examines whether those forms of education are used and if they are effective. Masella also asks some key challenging questions. His select and limited references lead to deeper studies about the nature and definition of professionalism and how it might be learned and presented. His suggestions for renewing professionalism are minimal; this sets the stage for proposing and selecting other ideas that need attention and development. Some of those ideas and suggestions, such as competition and collaboration, four types of dentistry, understanding two conflicting meanings of desire and need, and universal patient acceptance were recently explored in a workshop, "Professional Promises: Hopes and Gaps in Access to Oral Health Care" (procedings published in the November 2006 Journal of Dental Education), and were not yet available to Masella when his article was authored. His article, though, stimulates good discussion and action. Its data and substance show why, for example, dentistry needs to develop a core cadre of full-time practicing professional dental ethicists. Currently, there is only a small but very dedicated group of volunteers trying to meet our society's need to bring new life to professionalism in dentistry and our market. PMID:17314383

  7. Vinblastine fails to improve response of renal cancer to interferon alfa-n1: high response rate in patients with pulmonary metastases.

    PubMed

    Neidhart, J A; Anderson, S A; Harris, J E; Rinehart, J J; Laszlo, J; Dexeus, F H; Einhorn, L H; Trump, D L; Benedetto, P W; Tuttle, R L

    1991-05-01

    One hundred sixty-five patients were randomized to receive either interferon alfa-n1 (Wellferon; Burroughs Wellcome Co, Research Triangle Park, NC) alone or with vinblastine. An initial six-cycle induction treatment consisted of interferon given at daily doses of 3, 5, 20, 20, and 20 x 10(6) U/m2 every 2 weeks. Vinblastine at a dose of 10 mg/m2 (later decreased to 5 mg/m2) was given on day 1 of alternate cycles. Toxicities were generally well tolerated. The overall response rate was 10% with no significant difference between treatment arms. Survival was also not significantly different for the arms. A small subset of patients (16) with metastases only to the lungs had a high complete response (CR) and partial response (PR) rate of 44%. Responses were durable, and overall survival of this group was much better than that of the other patients. PMID:2016626

  8. Pathological complete response rate in hormone receptor-negative breast cancer treated with neoadjuvant FEC, followed by weekly paclitaxel administration: A retrospective study and review of the literature

    PubMed Central

    KIBA, TAKAYOSHI; MORII, NAO; TAKAHASHI, HIROTOSHI; OZAKI, SHINJI; ATSUMI, MISAO; MASUMOTO, FUMI; YAMASHIRO, HIROYASU

    2016-01-01

    by weekly administration of paclitaxel and/or trastuzumab induces a high pathological response and a high pCR rate in patients with hormone receptor-negative breast cancer. Due to the high clinical benefit rate and acceptable safety profile, this regimen should be considered an acceptable neoadjuvant treatment option for hormone receptor-negative breast cancer. PMID:27123064

  9. Acceptance procedures: Microfilm printer

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Acceptance tests were made for a special order automatic additive color microfilm printer. Tests include film capacity, film transport, resolution, illumination uniformity, exposure range checks, and color cuing considerations.

  10. Television station acceptance of AIDS prevention PSAs and condom advertisements.

    PubMed

    Abernethy, A M; Wicks, J L

    1998-01-01

    AIDS is a fatal, though preventable disease with more than 56,000 new cases reported in 1996 alone. Condom advertisements and AIDS public service announcements (AIDS PSAs) can help prevent the spread of AIDS, but these AIDS PSAs often contain controversial subject matter and are thus rejected for broadcast by television stations. It is for this reason why a large-scale national mail survey was conducted. The survey, which examined the impact of personal ethical considerations of television station management on AIDS acceptance decisions in the US, was based on five hypothetical questions. It used questionnaires mailed to television station managers. Responses were received from 364 stations, yielding a 40.63% response rate. Significant results were found related to the impact of personal ethical concerns of television managers on AIDS acceptance decision. Most stations were unlikely to accept condom or safe sex advertisements but were more likely to accept generic AIDS messages. These findings pose a dilemma for public health officials, which include the high cost of television advertisements and the difficulty in choosing a creative execution type. The most effective approach would be to appeal to sales managers to run the advertisements since they are important for the community and serve the public interest. PMID:12295801

  11. Television station acceptance of AIDS prevention PSAs and condom advertisements.

    PubMed

    Abernethy, A M; Wicks, J L

    1998-01-01

    AIDS is a fatal, though preventable disease with more than 56,000 new cases reported in 1996 alone. Condom advertisements and AIDS public service announcements (AIDS PSAs) can help prevent the spread of AIDS, but these AIDS PSAs often contain controversial subject matter and are thus rejected for broadcast by television stations. It is for this reason why a large-scale national mail survey was conducted. The survey, which examined the impact of personal ethical considerations of television station management on AIDS acceptance decisions in the US, was based on five hypothetical questions. It used questionnaires mailed to television station managers. Responses were received from 364 stations, yielding a 40.63% response rate. Significant results were found related to the impact of personal ethical concerns of television managers on AIDS acceptance decision. Most stations were unlikely to accept condom or safe sex advertisements but were more likely to accept generic AIDS messages. These findings pose a dilemma for public health officials, which include the high cost of television advertisements and the difficulty in choosing a creative execution type. The most effective approach would be to appeal to sales managers to run the advertisements since they are important for the community and serve the public interest.

  12. Question Style and Response Rates: Do People Prefer to Tick a Box or to Insert a Number When Filling out a Questionnaire?

    ERIC Educational Resources Information Center

    Fairweather, John R.; Gossman, Peter

    2004-01-01

    An important goal for postal surveys is maximization of the response rate. A high response rate improves confidence in the results and minimises costs. Response rates are known to be declining as the use of surveying has increased, particularly when the telephone is used. Members of the public, and farmers, now face surveys for commercial purposes…

  13. Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

    NASA Technical Reports Server (NTRS)

    Nandi, P. S.; Spodick, D. H.

    1977-01-01

    The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

  14. HPA and SAM axis responses as correlates of self- vs parental ratings of anxiety in boys with an Autistic Disorder.

    PubMed

    Bitsika, Vicki; Sharpley, Christopher F; Sweeney, John A; McFarlane, James R

    2014-03-29

    Anxiety and Autistic Disorder (AD) are both neurological conditions and both disorders share some features that make it difficult to precisely allocate specific symptoms to each disorder. HPA and SAM axis activities have been conclusively associated with anxiety, and may provide a method of validating anxiety rating scale assessments given by parents and their children with AD about those children. Data from HPA axis (salivary cortisol) and SAM axis (salivary alpha amylase) responses were collected from a sample of 32 high-functioning boys (M age=11yr) with an Autistic Disorder (AD) and were compared with the boys' and their mothers' ratings of the boys' anxiety. There was a significant difference between the self-ratings given by the boys and ratings given about them by their mothers. Further, only the boys' self-ratings of their anxiety significantly predicted the HPA axis responses and neither were significantly related to SAM axis responses. Some boys showed cortisol responses which were similar to that previously reported in children who had suffered chronic and severe anxiety arising from stressful social interactions. As well as suggesting that some boys with an AD can provide valid self-assessments of their anxiety, these data also point to the presence of very high levels of chronic HPA-axis arousal and consequent chronic anxiety in these boys.

  15. Ride quality - An exploratory study and criteria development. [visual motion simulator measurement of response ratings of ride quality of aircraft

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1974-01-01

    The Langley six degree of freedom visual motion simulator has been used to measure subjective response ratings of the ride quality of eight segments of flight, representative of a wide variation in comfort estimates. The results indicate that the use of simulators for this purpose appears promising. A preliminary approach for the development of criteria for ride quality ratings based on psychophysical precepts is included.

  16. Sweeteners: consumer acceptance in tea.

    PubMed

    Sprowl, D J; Ehrcke, L A

    1984-09-01

    Sucrose, fructose, aspartame, and saccharin were compared for consumer preference, aftertaste, and cost to determine acceptability of the sweeteners. A 23-member taste panel evaluated tea samples for preference and aftertaste. Mean retail cost of the sweeteners were calculated and adjusted to take sweetening power into consideration. Sucrose was the least expensive and most preferred sweetener. No significant difference in preference for fructose and aspartame was found, but both sweeteners were rated significantly lower than sucrose. Saccharin was the most disliked sweetener. Fructose was the most expensive sweetener and aspartame the next most expensive. Scores for aftertaste followed the same pattern as those for preference. Thus, a strong, unpleasant aftertaste seems to be associated with a dislike for a sweetener. From the results of this study, it seems that there is no completely acceptable low-calorie substitute for sucrose available to consumers.

  17. Greater Heart Rate Responses to Acute Stress Are Associated with Better Post-Error Adjustment in Special Police Cadets.

    PubMed

    Yao, Zhuxi; Yuan, Yi; Buchanan, Tony W; Zhang, Kan; Zhang, Liang; Wu, Jianhui

    2016-01-01

    High-stress jobs require both appropriate physiological regulation and behavioral adjustment to meet the demands of emergencies. Here, we investigated the relationship between the autonomic stress response and behavioral adjustment after errors in special police cadets. Sixty-eight healthy male special police cadets were randomly assigned to perform a first-time walk on an aerial rope bridge to induce stress responses or a walk on a cushion on the ground serving as a control condition. Subsequently, the participants completed a Go/No-go task to assess behavioral adjustment after false alarm responses. Heart rate measurements and subjective reports confirmed that stress responses were successfully elicited by the aerial rope bridge task in the stress group. In addition, greater heart rate increases during the rope bridge task were positively correlated with post-error slowing and had a trend of negative correlation with post-error miss rate increase in the subsequent Go/No-go task. These results suggested that stronger autonomic stress responses are related to better post-error adjustment under acute stress in this highly selected population and demonstrate that, under certain conditions, individuals with high-stress jobs might show cognitive benefits from a stronger physiological stress response. PMID:27428280

  18. Greater Heart Rate Responses to Acute Stress Are Associated with Better Post-Error Adjustment in Special Police Cadets

    PubMed Central

    Yao, Zhuxi; Yuan, Yi; Buchanan, Tony W.; Zhang, Kan; Zhang, Liang; Wu, Jianhui

    2016-01-01

    High-stress jobs require both appropriate physiological regulation and behavioral adjustment to meet the demands of emergencies. Here, we investigated the relationship between the autonomic stress response and behavioral adjustment after errors in special police cadets. Sixty-eight healthy male special police cadets were randomly assigned to perform a first-time walk on an aerial rope bridge to induce stress responses or a walk on a cushion on the ground serving as a control condition. Subsequently, the participants completed a Go/No-go task to assess behavioral adjustment after false alarm responses. Heart rate measurements and subjective reports confirmed that stress responses were successfully elicited by the aerial rope bridge task in the stress group. In addition, greater heart rate increases during the rope bridge task were positively correlated with post-error slowing and had a trend of negative correlation with post-error miss rate increase in the subsequent Go/No-go task. These results suggested that stronger autonomic stress responses are related to better post-error adjustment under acute stress in this highly selected population and demonstrate that, under certain conditions, individuals with high-stress jobs might show cognitive benefits from a stronger physiological stress response. PMID:27428280

  19. Heart Rate Responses to Unaided Orion Side Hatch Egress in the Neutral Buoyancy Laboratory

    NASA Technical Reports Server (NTRS)

    English, Kirk L.; Hwang Emma Y.; Ryder, Jeffrey W.; Kelly, Cody; Walker, Thomas; Ploutz-Snyder, Lori L.

    2016-01-01

    NASA is developing the Orion capsule as a vehicle for transporting crewmembers to and from the International Space Station (ISS) and for future human space exploration missions. Orion and other commercial vehicles are designed to splash down in the ocean where nominally support personnel will assist crewmembers in egressing the vehicle. However, off-nominal scenarios will require crewmembers to egress the vehicle unaided, deploy survival equipment, and ingress a life raft. PURPOSE: To determine the heart rate (HR) responses to unaided Orion side hatch egress and raft ingress as a part of the NASA Crew Survival Engineering Team's evaluation of the PORT Orion mockup in the Neutral Buoyancy Laboratory (NBL). METHODS: Nineteen test subjects, including four astronauts (N=19, 14 males/5 females, 38.6+/-8.4 y, 174.4+/-9.6 cm, 75.7+/-13.1 kg), completed a graded maximal test on a cycle ergometer to determine VO2peak and HRpeak and were divided into five crews of four members each; one subject served on two crews. Each crew was required to deploy a life raft, egress the Orion vehicle from the side hatch, and ingress the life raft with two 8 kg emergency packs per crew. Each crew performed this activity one to three times; a total of ten full egresses were completed. Subjects wore a suit that was similar in form, mass, and function to the Modified Advanced Crew Escape Suit (MACES) including helmet, gloves, boots, supplemental O2 bottles, and a CO2-inflated life preserver (approx.18 kg); subjects began each trial seated supine in the PORT Orion mockup with seat belts and mockup O2 and communication connections and ended each trial with all four crewmembers inside the life raft. RESULTS: VO2peak was 40.8+/-6.8 mL/kg/min (3.1+/-0.7 L/min); HRpeak was 181+/-10 bpm. Total egress time across trials was 5.0+/-1.6 min (range: 2.8-8.0 min); all subjects were able to successfully complete all trials. Average maximum HR at activity start, at the hatch opening, in the water, and in the

  20. Do incentives, reminders or reduced burden improve healthcare professional response rates in postal questionnaires? two randomised controlled trials

    PubMed Central

    2012-01-01

    Background Healthcare professional response rates to postal questionnaires are declining and this may threaten the validity and generalisability of their findings. Methods to improve response rates do incur costs (resources) and increase the cost of research projects. The aim of these randomised controlled trials (RCTs) was to assess whether 1) incentives, 2) type of reminder and/or 3) reduced response burden improve response rates; and to assess the cost implications of such additional effective interventions. Methods Two RCTs were conducted. In RCT A general dental practitioners (dentists) in Scotland were randomised to receive either an incentive; an abridged questionnaire or a full length questionnaire. In RCT B non-responders to a postal questionnaire sent to general medical practitioners (GPs) in the UK were firstly randomised to receive a second full length questionnaire as a reminder or a postcard reminder. Continued non-responders from RCT B were then randomised within their first randomisation to receive a third full length or an abridged questionnaire reminder. The cost-effectiveness of interventions that effectively increased response rates was assessed as a secondary outcome. Results There was no evidence that an incentive (52% versus 43%, Risk Difference (RD) -8.8 (95%CI −22.5, 4.8); or abridged questionnaire (46% versus 43%, RD −2.9 (95%CI −16.5, 10.7); statistically significantly improved dentist response rates compared to a full length questionnaire in RCT A. In RCT B there was no evidence that a full questionnaire reminder statistically significantly improved response rates compared to a postcard reminder (10.4% versus 7.3%, RD 3 (95%CI −0.1, 6.8). At a second reminder stage, GPs sent the abridged questionnaire responded more often (14.8% versus 7.2%, RD −7.7 (95%CI −12.8, -2.6). GPs who received a postcard reminder followed by an abridged questionnaire were most likely to respond (19.8% versus 6.3%, RD 8.1%, and 9.1% for full

  1. Preschool Children's Beliefs about the Acceptability of Relational and Physical Aggression

    ERIC Educational Resources Information Center

    Swit, Cara S.; McMaugh, Anne; Warburton, Wayne A.

    2016-01-01

    This research examined differences in beliefs about the acceptability of aggression and behavioral responses to aggression of preschool-aged children. Two groups, identified from teacher ratings, participated in the research. One group of children exhibited relationally aggressive behaviors, and a comparison group was identified with…

  2. Prospective evaluation of direct approach with a tablet device as a strategy to enhance survey study participant response rate

    PubMed Central

    2012-01-01

    Background Investigators conduct survey studies for a variety of reasons. Poor participant response rates are common, however, and may limit the generalizability and utility of results. The objective of this study was to determine whether direct approach with a tablet device enhances survey study participant response rate and to assess participants’ experiences with this mode of survey administration. Findings An interventional study nested within a single center survey study was conducted at McMaster Children’s Hospital. The primary outcome was the ability to achieve of a survey study response rate of 70% or greater. Eligible participants received 3 email invitations (Week 0, 2, 4) to complete a web-based (Survey Monkey) survey. The study protocol included plans for a two-week follow-up phase (Phase 2) where non-responders were approached by a research assistant and invited to complete an iPad-based version of the survey. The Phase 1 response rate was 48.7% (56/115). Phase 2 effectively recruited reluctant responders, increasing the overall response rate to 72.2% (83/115). On a 7-point Likert scale, reluctant responders highly rated their enjoyment (mean 6.0, sd 0.83 [95% CI: 5.7-6.3]) and ease of use (mean 6.7, sd 0.47 [95% CI: 6.5-6.9]) completing the survey using the iPad. Reasons endorsed for Phase 2 participation included: direct approach (81%), immediate survey access (62%), and the novelty of completing a tablet-based survey (54%). Most reluctant responders (89%) indicated that a tablet-based survey is their preferred method of survey completion. Conclusions Use of a tablet-based version of the survey was effective in recruiting reluctant responders and this group reported positive experiences with this mode of survey administration. PMID:23110849

  3. Speed of Inhibition Predicts Teacher--Rated Medication Response in Boys with Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Scheres, Anouk; Oosterlaan, Jaap; Sergeant, Joseph A.

    2006-01-01

    This study aimed at investigating whether one of the key deficits in Attention Deficit Hyperactivity Disorder (ADHD), slow response inhibition, predicted the response to methylphenidate (MPH) treatment. In order to address this issue, we used Stop Signal Reaction Times (SSRTs) measured at baseline in 20 medication-naive boys with ADHD as…

  4. Rate and timing of cortical responses driven by separate sensory channels

    PubMed Central

    Saal, Hannes P; Harvey, Michael A; Bensmaia, Sliman J

    2015-01-01

    The sense of touch comprises multiple sensory channels that each conveys characteristic signals during interactions with objects. These neural signals must then be integrated in such a way that behaviorally relevant information about the objects is preserved. To understand the process of integration, we implement a simple computational model that describes how the responses of neurons in somatosensory cortex—recorded from awake, behaving monkeys—are shaped by the peripheral input, reconstructed using simulations of neuronal populations that reproduce natural spiking responses in the nerve with millisecond precision. First, we find that the strength of cortical responses is driven by one population of nerve fibers (rapidly adapting) whereas the timing of cortical responses is shaped by the other (Pacinian). Second, we show that input from these sensory channels is integrated in an optimal fashion that exploits the disparate response behaviors of different fiber types. DOI: http://dx.doi.org/10.7554/eLife.10450.001 PMID:26650354

  5. Response to "Rating Teachers Cheaper, Faster, and Better: Not so Fast": It's About Evidence

    ERIC Educational Resources Information Center

    Gargani, John; Strong, Michael

    2015-01-01

    In Gargani and Strong (2014), we describe The Rapid Assessment of Teacher Effectiveness (RATE), a new teacher evaluation instrument. Our account of the validation research associated with RATE inspired a review by Good and Lavigne (2015). Here, we reply to the main points of their review. We elaborate on the validity, reliability, theoretical…

  6. Effects of head-down bed rest on complex heart rate variability: Response to LBNP testing

    NASA Technical Reports Server (NTRS)

    Goldberger, Ary L.; Mietus, Joseph E.; Rigney, David R.; Wood, Margie L.; Fortney, Suzanne M.

    1994-01-01

    Head-down bed rest is used to model physiological changes during spaceflight. We postulated that bed rest would decrease the degree of complex physiological heart rate variability. We analyzed continuous heart rate data from digitized Holter recordings in eight healthy female volunteers (age 28-34 yr) who underwent a 13-day 6 deg head-down bed rest study with serial lower body negative pressure (LBNP) trials. Heart rate variability was measured on a 4-min data sets using conventional time and frequency domain measures as well as with a new measure of signal 'complexity' (approximate entropy). Data were obtained pre-bed rest (control), during bed rest (day 4 and day 9 or 11), and 2 days post-bed rest (recovery). Tolerance to LBNP was significantly reduced on both bed rest days vs. pre-bed rest. Heart rate variability was assessed at peak LBNP. Heart rate approximate entropy was significantly decreased at day 4 and day 9 or 11, returning toward normal during recovery. Heart rate standard deviation and the ratio of high- to low-power frequency did not change significantly. We conclude that short-term bed rest is associated with a decrease in the complex variability of heart rate during LBNP testing in healthy young adult women. Measurement of heart rate complexity, using a method derived from nonlinear dynamics ('chaos theory'), may provide a sensitive marker of this loss of physiological variability, complementing conventional time and frequency domain statistical measures.

  7. Open-Access Colleges Responsible for Greatest Gains in Graduation Rates. Policy Alert

    ERIC Educational Resources Information Center

    Doyle, William R.

    2010-01-01

    The largest gains in graduation rates over the past decade have been accomplished at open-access or nearly open-access colleges and universities. In addition, states could see even bigger increases if they directed their policies and supports toward improving graduation rates at these nonselective institutions. These findings from the author's…

  8. Measurement differences from rating posttraumatic stress disorder symptoms in response to differentially distressing traumatic events.

    PubMed

    Elhai, Jon D; Fine, Thomas H

    2012-09-01

    The authors explored differences in posttraumatic stress disorder (PTSD) symptoms as a result of rating symptoms from two separate, differentially distressing traumatic events. In an initial sample of 400 nonclinical participants, the authors inquired through a web survey about previous psychological trauma, instructing participants to nominate their most distressing and second most distressing traumatic events experienced. Using the PTSD Checklist, participants rated their PTSD symptoms separately from these worst and second worst events. Using the four-factor emotional numbing PTSD model in confirmatory factor analysis, results demonstrated evidence supporting separation of PTSD symptom rating sets from two differentially distressing traumas-specifically, the worst and second worst events. Measurement invariance tests revealed that factor loadings did not vary between the worst and second worst event PTSD ratings; item thresholds (indexing symptom severity) differed. Results generally support the recommended PTSD assessment protocol instructing participants to rate PTSD symptoms from a single, worst index event.

  9. Influence of Motion Picture Rating on Adolescent Response to Movie Smoking

    PubMed Central

    Tanski, Susanne; Stoolmiller, Mike

    2012-01-01

    OBJECTIVE: To examine the association between movie smoking exposure (MSE) and adolescent smoking according to rating category. METHODS: A total of 6522 US adolescents were enrolled in a longitudinal survey conducted at 8-month intervals; 5503 subjects were followed up at 8 months, 5019 subjects at 16 months, and 4575 subjects at 24 months. MSE was estimated from 532 recent box-office hits, blocked into 3 Motion Picture Association of America rating categories: G/PG, PG-13, and R. A survival model evaluated time to smoking onset. RESULTS: Median MSE in PG-13–rated movies was ∼3 times higher than median MSE from R-rated movies, but their relation with smoking was essentially the same, with adjusted hazard ratios of 1.49 (95% confidence interval [CI]: 1.23–1.81) and 1.33 (95% CI: 1.23–1.81) for each additional 500 occurrences of MSE respectively. MSE from G/PG-rated movies was small and had no significant relationship with adolescent smoking. Attributable risk estimates showed that adolescent smoking would be reduced by 18% (95% CI: 14–21) if smoking in PG-13–rated movies was reduced to the fifth percentile. In comparison, making all parents maximally authoritative in their parenting would reduce adolescent smoking by 16% (95% CI: 12–19). CONCLUSIONS: The equivalent effect of PG-13-rated and R-rated MSE suggests it is the movie smoking that prompts adolescents to smoke, not other characteristics of R-rated movies or adolescents drawn to them. An R rating for movie smoking could substantially reduce adolescent smoking by eliminating smoking from PG-13 movies. PMID:22778305

  10. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources

    PubMed Central

    Vandana, S.; Sharma, S. D.

    2010-01-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference 137Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference 137Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference 137Cs source. All required correction factors were applied in the calculation of the RAKR of the 137Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within ±0.5% for about three years after calibration/recalibration. However, it shows deviations larger than ±0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years. PMID:20589119

  11. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources.

    PubMed

    Vandana, S; Sharma, S D

    2010-04-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference (137)Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference (137)Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference (137)Cs source. All required correction factors were applied in the calculation of the RAKR of the (137)Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within +/-0.5% for about three years after calibration/recalibration. However, it shows deviations larger than +/-0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  12. Defining Treatment Response and Symptom Remission for Anxiety Disorders in Pediatric Autism Spectrum Disorders Using the Pediatric Anxiety Rating Scale

    ERIC Educational Resources Information Center

    Johnco, Carly J.; De Nadai, Alessandro S.; Lewin, Adam B.; Ehrenreich-May, Jill; Wood, Jeffrey J.; Storch, Eric A.

    2015-01-01

    This study examined optimal guidelines to assess treatment response and remission for anxiety in youth with autism spectrum disorders (ASD) using the Pediatric Anxiety Rating Scale (PARS). Data was collected for 108 children aged 7-16 years with comorbid anxiety and ASD before and after receiving cognitive behavior therapy. Optimal cut-offs on the…

  13. Conducting Field Research in a Primary School Setting: Methodological Considerations for Maximizing Response Rates, Data Quality and Quantity

    ERIC Educational Resources Information Center

    Trapp, Georgina; Giles-Corti, Billie; Martin, Karen; Timperio, Anna; Villanueva, Karen

    2012-01-01

    Background: Schools are an ideal setting in which to involve children in research. Yet for investigators wishing to work in these settings, there are few method papers providing insights into working efficiently in this setting. Objective: The aim of this paper is to describe the five strategies used to increase response rates, data quality and…

  14. Effects of growth medium and fertilizer rate on the yield response of soybeans exposed to chronic doses of ozone

    SciTech Connect

    Heagle, A.S.; Letchworth, M.B.; Mitchell, C.A.

    1983-01-01

    The objectives were to determine whether wide variation in fertilizer rates or type of growth medium would affect the response of soybeans, Glycine max 'Davis' exposed to chronic doses of ozone (O/sub 3/) in open-top field chambers. Responses to O/sub 3/ were compared for plants grown in the ground or in pots containing an artificial growth medium. In 1977, the yield of plants grown in pots containing soil, sand, and a mixture of perlite, peat moss, and vermiculite was greater than that of plants grown in the ground; in 1978, the reverse was true. However, the percentage yeild loss caused by O/sub 3/ was not affected by the growth medium either year. Separate tests were made for potted plants that received different levels of fertilizer. At moderate fertilizer rates, the yield response to different doses of O/sub 3/ was not significantly affected by fertilizer rate for either year. In 1978, plants with no fertilizer added were severely stunted and even relatively high doses of O/sub 3/ did not further decrease yield. The results suggest that plant response to O/sub 3/ will be fairly uniform over a range of substrate types and fertilizer rates when edaphic conditions are adequate to insure normal plant growth. 17 references, 5 figures, 2 tables.

  15. Heart Rate and VO[subscript 2] Responses to Cycle Ergometry in White and African American Men

    ERIC Educational Resources Information Center

    Vehrs, Pat R.; Fellingham, Gilbert W.

    2006-01-01

    The validity of estimates of peak oxygen consumption (VO[subscript 2]peak) using submaximal exercise tests may be compromised when the participants being tested are not similar to the participants used to develop the test. This study compared ethnic differences in the heart rate (HR) and oxygen consumption (VO[subscript 2]) responses to submaximal…

  16. Effects of Respondents' Socioeconomic Status and Timing and Amount of Incentive Payment on Mailed Questionnaire Response Rates.

    ERIC Educational Resources Information Center

    Parthasarathy, Anuradha; And Others

    The study examined how response rate to a mailed questionnaire was influenced by the socioeconomic status (SES) of respondents (high, middle, or low); amount of payment of a monetary incentive (none, $1, or $2); and time of payment (prepaid or promised on return of the completed questionnaire). Subjects were 125 adults in Cache County, Utah at…

  17. Defining Treatment Response and Remission in Child Anxiety: Signal Detection Analysis Using the Pediatric Anxiety Rating Scale

    ERIC Educational Resources Information Center

    Caporino, Nicole E.; Brodman, Douglas M.; Kendall, Philip C.; Albano, Anne Marie; Sherrill, Joel; Piacentini, John; Sakolsky, Dara; Birmaher, Boris; Compton, Scott N.; Ginsburg, Golda; Rynn, Moira; McCracken, James; Gosch, Elizabeth; Keeton, Courtney; March, John; Walkup, John T.

    2013-01-01

    Objective: To determine optimal Pediatric Anxiety Rating Scale (PARS) percent reduction and raw score cut-offs for predicting treatment response and remission among children and adolescents with anxiety disorders. Method: Data were from a subset of youth (N = 438; 7-17 years of age) who participated in the Child/Adolescent Anxiety Multimodal Study…

  18. Prenotification, Incentives, and Survey Modality: An Experimental Test of Methods to Increase Survey Response Rates of School Principals

    ERIC Educational Resources Information Center

    Jacob, Robin Tepper; Jacob, Brian

    2012-01-01

    Teacher and principal surveys are among the most common data collection techniques employed in education research. Yet there is remarkably little research on survey methods in education, or about the most cost-effective way to raise response rates among teachers and principals. In an effort to explore various methods for increasing survey response…

  19. Technical Analysis of Father Responses to the Disruptive Behavior Rating Scale-Parent Version (DBRS-P).

    ERIC Educational Resources Information Center

    Erford, Bradley T.

    1998-01-01

    The Disruptive Behavior Rating Scale (DBRS) was designed to differentiate among the disruptive behavior disorders through administration to teachers and parents. Four studies are presented here to provide a technical analysis to fathers' responses to the DBRS-Parent Version. Reliability and construct and criterion-related validity of father…

  20. "We Thought It Might Encourage Participation." Using Lottery Incentives to Improve LibQUAL+[TM] Response Rates among Students

    ERIC Educational Resources Information Center

    Buck, Stefanie; Nutefall, Jennifer E.; Bridges, Laurie M.

    2012-01-01

    Libraries deploying the LibQUAL+[TM] survey can offer a lottery incentive and many do so in the hope of increasing response rates. Other libraries may be prohibited from offering one because of Institutional Review Board restrictions, as is the case at Oregon State University. We wanted to discover why libraries offer lottery incentives, what…

  1. Effects of Familiarity with Sender on Response Rate of Mail Questionnaires and Their Implications for Program Evaluation.

    ERIC Educational Resources Information Center

    Taylor, C. L.; And Others

    The effects on response rate of familiarity with survey sender was investigated in a study involving the University of Florida's Institute of Food and Agricultural Sciences faculty. The study was part of a mail survey of 3,467 citrus producers in 23 counties in Florida. Half (1,790) of the producers on the agricultural agent's mailing lists were…

  2. Diffusion of Innovation Theory and Xbox Live: Examining Minority Gamers' Responses and Rate of Adoption to Changes in Xbox Live

    ERIC Educational Resources Information Center

    Gray, Kishonna L.

    2012-01-01

    This article examines the response of minority gamers as they adopt new innovations in Xbox Live. Using diffusion of innovation theory, specific attention is given to gamers' rate of adoption of the new Xbox Live environment, which was a recent update to the Xbox Live interface. By employing virtual ethnography, observations, and interviews reveal…

  3. Incentive and Reminder Strategies to Improve Response Rate for Internet-Based Physician Surveys: A Randomized Experiment

    PubMed Central

    Wittich, Christopher M; Daniels, Wendlyn L; West, Colin P; Harris, Ann M; Beebe, Timothy J

    2016-01-01

    Background Most research on how to enhance response rates in physician surveys has been done using paper surveys. Uncertainties remain regarding how to enhance response rates in Internet-based surveys. Objective To evaluate the impact of a low-cost nonmonetary incentive and paper mail reminders (formal letter and postcard) on response rates in Internet-based physician surveys. Methods We executed a factorial-design randomized experiment while conducting a nationally representative Internet-based physician survey. We invited 3966 physicians (randomly selected from a commercial database of all licensed US physicians) via email to complete an Internet-based survey. We used 2 randomly assigned email messages: one message offered a book upon survey completion, whereas the other did not mention the book but was otherwise identical. All nonrespondents received several email reminders. Some physicians were further assigned at random to receive 1 reminder via paper mail (either a postcard or a letter) or no paper reminder. The primary outcome of this study was the survey response rate. Results Of the 3966 physicians who were invited, 451 (11.4%) responded to at least one survey question and 336 (8.5%) completed the entire survey. Of those who were offered a book, 345/2973 (11.6%) responded compared with 106/993 (10.7%) who were not offered a book (odds ratio 1.10, 95% CI 0.87-1.38, P=.42). Regarding the paper mail reminder, 168/1572 (10.7%) letter recipients, 148/1561 (9.5%) postcard recipients, and 69/767 (9.0%) email-only recipients responded (P=.35). The response rate for those receiving letters or postcards was similar (odds ratio 1.14, 95% CI 0.91-1.44, P=.26). Conclusions Offering a modest nonmonetary incentive and sending a paper reminder did not improve survey response rate. Further research on how to enhance response rates in Internet-based physician surveys is needed. PMID:27637296

  4. Strain rate response of a Ni-Ti shape memory alloy after hydrogen charging

    NASA Astrophysics Data System (ADS)

    Gamaoun, Fehmi; Hassine, Tarak; Bouraoui, Tarak

    2014-01-01

    In this work, we investigate the susceptibility of Ni-Ti superelastic wires to the strain rates during tensile testing after hydrogen charging. Cathodic hydrogen charging is performed at a current density of 10 A/m² during 2-12 h in 0.9% NaCl solution and aged for 24 h at room temperature. Specimens underwent one cycle of loading-unloading reaching a stress value of 700 MPa. During loading, strain rates from 10-6 to 5 × 10-2 s-1 have been achieved. After 8 h of hydrogen charging, an embrittlement has been detected in the tensile strain rate range of 10-6 to 10-4 s-1. In contrast, no embrittlement has been detected for strain rates of 10-3 s-1 and higher. However, after 12 h of hydrogen charging and 24 h of annealing at room temperature, the embrittlement occurs in the beginning of the austenite-martensite transformation for all the studied strain rate values. These results show that for a range of critical amounts of diffused hydrogen, the embrittlement of the Ni-Ti superelastic alloy strongly depends on the strain rate during the tensile test. Moreover, it has been shown that this embrittlement occurs for low values of strain rates rather than the higher ones. This behaviour is attributed to the interaction between the diffused hydrogen and growth of the martensitic domain.

  5. Constant-load versus heart rate-targeted exercise - Responses of systolic intervals

    NASA Technical Reports Server (NTRS)

    Lance, V. Q.; Spodick, D. H.

    1975-01-01

    Various systolic intervals were measured prior to and during heart rate-targeted bicycle ergometer exercise. There were striking similarities within each matched exercise set for Q-Im, isovolumetric contraction time, preejection period (PEP), and PEP/left ventricular ejection time (LVET). LVET was significantly shorter for rate-targeted exercise. It is concluded that either constant-load or rate-targeted bicycle ergometry may be used with the choice of method determined by the purpose of the protocol, and that systolic intervals (except LVET) should not be much altered owing to the method chosen.

  6. Laser-based irradiation apparatus and methods for monitoring the dose-rate response of semiconductor devices

    DOEpatents

    Horn, Kevin M.

    2006-03-28

    A scanned, pulsed, focused laser irradiation apparatus can measure and image the photocurrent collection resulting from a dose-rate equivalent exposure to infrared laser light across an entire silicon die. Comparisons of dose-rate response images or time-delay images from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems allows precise identification of those specific age-affected circuit structures within a device that merit further quantitative analysis with targeted materials or electrical testing techniques. Another embodiment of the invention comprises a broad-beam, dose rate-equivalent exposure apparatus. The broad-beam laser irradiation apparatus can determine if aging has affected the device's overall functionality. This embodiment can be combined with the synchronized introduction of external electrical transients into a device under test to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure.

  7. Temperature sensitivity of soil respiration rates enhanced by microbial community response.

    PubMed

    Karhu, Kristiina; Auffret, Marc D; Dungait, Jennifer A J; Hopkins, David W; Prosser, James I; Singh, Brajesh K; Subke, Jens-Arne; Wookey, Philip A; Agren, Göran I; Sebastià, Maria-Teresa; Gouriveau, Fabrice; Bergkvist, Göran; Meir, Patrick; Nottingham, Andrew T; Salinas, Norma; Hartley, Iain P

    2014-09-01

    Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. PMID:25186902

  8. Temperature sensitivity of soil respiration rates enhanced by microbial community response.

    PubMed

    Karhu, Kristiina; Auffret, Marc D; Dungait, Jennifer A J; Hopkins, David W; Prosser, James I; Singh, Brajesh K; Subke, Jens-Arne; Wookey, Philip A; Agren, Göran I; Sebastià, Maria-Teresa; Gouriveau, Fabrice; Bergkvist, Göran; Meir, Patrick; Nottingham, Andrew T; Salinas, Norma; Hartley, Iain P

    2014-09-01

    Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.

  9. Heart Rate Response to Blood Pressure Variations: Sympathetic Activation versus Baroreflex Response in Patients with End-Stage Renal Disease

    PubMed Central

    Sapoznikov, Dan; Dranitzki Elhalel, Michal; Rubinger, Dvora

    2013-01-01

    Background Continuous systolic blood pressure (SBP) and interbeat intervals (IBI) recordings reveal sequences of consecutive beats in which SBP and heart rate change in opposite direction, representing negative feedback baroreflex mechanisms, as well as sequences in which SBP and heart rate change in the same direction (non-baroreflex), believed to represent feedforward control mechanisms. The present study was undertaken to assess the relationship between baroreflex and non-baroreflex sequences in end stage renal insufficiency. Methodology/Principal Findings Continuous beat-to-beat SBP and IBI monitoring was performed in patients on chronic hemodialysis (HD, n=72), in age-matched patients after renal transplantation (TX, n=41) and healthy (control) individuals (C, n=34). The proportion of baroreflex and nonbaroreflex episodes and the b coefficients (the regression line slope of SBP-IBI correlation) were determined using a newly developed 1 minute sliding window method, the classical sequence technique and the "Z" coefficient method. Analysis using the 1 minute sliding window showed an increased proportion of baroreflex episodes in controls and HD, and predominance of nonbaroreflex episodes in TX. An increased proportion of nonbaroreflex episodes in TX patients relative to HD was also revealed by the "Z" method. Baroreflex and nonbaroreflex b coefficients obtained by all methods were markedly decreased in HD. This alteration was reversed at least partly in TX. In HD, both baroreflex and nonbaroreflex b coefficients were inversely correlated to age and CRP levels; in TX, the nonbaroreflex b coefficient was influenced by the type of calcineurin inhibitor. Conclusion/Significance Renal status affects the contribution of baroreflex and nonbaroreflex mechanisms and the strength of SBP-IBI relationship. The predominant contribution of nonbaroreflex mechanisms in TX may be suggestive of enhanced central sympathetic control. Our data may be relevant for understanding of

  10. Temperature responses of substrate carbon conversion efficiencies and growth rates of plant tissues.

    PubMed

    Hansen, Lee D; Thomas, Nathan R; Arnholdt-Schmitt, Birgit

    2009-12-01

    Growth rates of plant tissues depend on both the respiration rate and the efficiency with which carbon is incorporated into new structural biomass. Calorespirometric measurement of respiratory heat and CO2 rates, from which both efficiency and growth rate can be calculated, is a well established method for determining the effects of rapid temperature changes on the respiratory and growth properties of plant tissues. The effect of the alternative oxidase/cytochrome oxidase activity ratio on efficiency is calculated from first principles. Data on the temperature dependence of the substrate carbon conversion efficiency are tabulated. These data show that epsilon is maximum and approximately constant through the optimum growth temperature range and decreases rapidly as temperatures approach temperature limits to growth. The width of the maximum and the slopes of decreasing epsilon at high and low temperatures vary greatly with species, cultivars and accessions.

  11. How to handle anxiety: The effects of reappraisal, acceptance, and suppression strategies on anxious arousal.

    PubMed

    Hofmann, Stefan G; Heering, Sanna; Sawyer, Alice T; Asnaani, Anu

    2009-05-01

    It has been suggested that reappraisal strategies are more effective than suppression strategies for regulating emotions. Recently, proponents of the acceptance-based behavior therapy movement have further emphasized the importance of acceptance-based emotion regulation techniques. In order to directly compare these different emotion regulation strategies, 202 volunteers were asked to give an impromptu speech in front of a video camera. Participants were randomly assigned to one of three groups. The Reappraisal group was instructed to regulate their anxious arousal by reappraising the situation; the Suppression group was asked to suppress their anxious behaviors; and the Acceptance group was instructed to accept their anxiety. As expected, the Suppression group showed a greater increase in heart rate from baseline than the Reappraisal and Acceptance groups. Moreover, the Suppression group reported more anxiety than the Reappraisal group. However, the Acceptance and Suppression groups did not differ in their subjective anxiety response. These results suggest that both reappraising and accepting anxiety is more effective for moderating the physiological arousal than suppressing anxiety. However, reappraising is more effective for moderating the subjective feeling of anxiety than attempts to suppress or accept it.

  12. Response of MnBi-Bi eutectic to freezing rate changes

    NASA Technical Reports Server (NTRS)

    Nair, M.; Fu, T.-W.; Wilcox, W. R.; Doddi, K.; Ravishankar, P. S.; Larson, D.

    1982-01-01

    Reference is made to a study by Fu and Wilcox (1981), which treated theoretically the influence on freezing rate of sudden changes in translation rate in the Bridgman-Stockbarger technique. This treatment is extended here to a linear ramped translation rate and an oscillatory freezing rate. It is found that oscillations above a few hertz are highly damped in small-diameter apparatus. An experimental test is carried out of the theoretical predictions for a sudden change of translation rate. The MnBi-Bi eutectic is solidified with current-induced interface demarcation. The experimental results accord reasonably well with theory if the silica ampoule wall is assumed to either (1) contribute only a resistance to heat exchange between the sample and the furnace wall or (2) transmit heat effectively in the axial direction by radiation. In an attempt to explain the fact that a finer microstructure is obtained in space, MnBi-Bi microstructure is determined when the freezing rate is increased or decreased rapidly. Preliminary results suggest that fiber branching does not occur as readily as fiber termination.

  13. Let's not be indifferent about neutrality: Neutral ratings in the International Affective Picture System (IAPS) mask mixed affective responses.

    PubMed

    Schneider, Iris K; Veenstra, Lotte; van Harreveld, Frenk; Schwarz, Norbert; Koole, Sander L

    2016-06-01

    The International Affective Picture System (IAPS) is a picture set used by researchers to select pictures that have been prerated on valence. Researchers rely on the ratings in the IAPS to accurately reflect the degree to which the pictures elicit affective responses. Here we show that this may not always be a safe assumption. More specifically, the scale used to measure valence in the IAPS ranges from positive to negative, implying that positive and negative feelings are end-points of the same construct. This makes interpretation of midpoint, or neutral ratings, especially problematic because it is impossible to tell whether these ratings are the result of neutral, or of mixed feelings. In other words, neutral ratings may not be as neutral as researchers assume them to be. Investigating this, in this work we show that pictures that seem neutral according to the valence ratings in the IAPS indeed vary in levels of ambivalence they elicit. Furthermore, the experience of ambivalence in response to these pictures is predictive of the arousal that people report feeling when viewing these pictures. These findings are of particular importance because neutrality differs from ambivalence in its specific psychological consequences, and by relying on seemingly neutral valance ratings, researchers may unwillingly introduce these consequences into their research design, undermining their level of experimental control. (PsycINFO Database Record

  14. Students Accepted on Probation.

    ERIC Educational Resources Information Center

    Lorberbaum, Caroline S.

    This report is a justification of the Dalton Junior College admissions policy designed to help students who had had academic and/or social difficulties at other schools. These students were accepted on probation, their problems carefully analyzed, and much effort devoted to those with low academic potential. They received extensive academic and…

  15. Approaches to acceptable risk

    SciTech Connect

    Whipple, C.

    1997-04-30

    Several alternative approaches to address the question {open_quotes}How safe is safe enough?{close_quotes} are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made.

  16. Why was Relativity Accepted?

    NASA Astrophysics Data System (ADS)

    Brush, S. G.

    Historians of science have published many studies of the reception of Einstein's special and general theories of relativity. Based on a review of these studies, and my own research on the role of the light-bending prediction in the reception of general relativity, I discuss the role of three kinds of reasons for accepting relativity (1) empirical predictions and explanations; (2) social-psychological factors; and (3) aesthetic-mathematical factors. According to the historical studies, acceptance was a three-stage process. First, a few leading scientists adopted the special theory for aesthetic-mathematical reasons. In the second stage, their enthusiastic advocacy persuaded other scientists to work on the theory and apply it to problems currently of interest in atomic physics. The special theory was accepted by many German physicists by 1910 and had begun to attract some interest in other countries. In the third stage, the confirmation of Einstein's light-bending prediction attracted much public attention and forced all physicists to take the general theory of relativity seriously. In addition to light-bending, the explanation of the advance of Mercury's perihelion was considered strong evidence by theoretical physicists. The American astronomers who conducted successful tests of general relativity became defenders of the theory. There is little evidence that relativity was `socially constructed' but its initial acceptance was facilitated by the prestige and resources of its advocates.

  17. OnlineTED.com − a novel web-based audience response system for higher education. A pilot study to evaluate user acceptance

    PubMed Central

    Kühbeck, Felizian; Engelhardt, Stefan; Sarikas, Antonio

    2014-01-01

    Background and aim: Audience response (AR) systems are increasingly used in undergraduate medical education. However, high costs and complexity of conventional AR systems often limit their use. Here we present a novel AR system that is platform independent and does not require hardware clickers or additional software to be installed. Methods and results: “OnlineTED” was developed at Technische Universität München (TUM) based on Hypertext Preprocessor (PHP) with a My Structured Query Language (MySQL)-database as server- and Javascript as client-side programming languages. “OnlineTED” enables lecturers to create and manage question sets online and start polls in-class via a web-browser. Students can participate in the polls with any internet-enabled device (smartphones, tablet-PCs or laptops). A paper-based survey was conducted with undergraduate medical students and lecturers at TUM to compare "OnlineTED" with conventional AR systems using clickers. "OnlineTED" received above-average evaluation results by both students and lecturers at TUM and was seen on par or superior to conventional AR systems. The survey results indicated that up to 80% of students at TUM own an internet-enabled device (smartphone or tablet-PC) for participation in web-based AR technologies. Summary and Conclusion: “OnlineTED” is a novel web-based and platform-independent AR system for higher education that was well received by students and lecturers. As a non-commercial alternative to conventional AR systems it may foster interactive teaching in undergraduate education, in particular with large audiences. PMID:24575156

  18. Aquaporins in ovine amnion: responses to altered amniotic fluid volumes and intramembranous absorption rates.

    PubMed

    Cheung, Cecilia Y; Anderson, Debra F; Brace, Robert A

    2016-07-01

    Aquaporins (AQPs) are transmembrane channel proteins that facilitate rapid water movement across cell membranes. In amniotic membrane, the AQP-facilitated transfer of water across amnion cells has been proposed as a mechanism for amniotic fluid volume (AFV) regulation. To investigate whether AQPs modulate AFV by altering intramembranous absorption (IMA) rate, we tested the hypothesis that AQP gene expression in the amnion is positively correlated with IMA rate during experimental conditions when IMA rate and AFV are modified over a wide range. The relative abundances of AQP1, AQP3, AQP8, AQP9, and AQP11 mRNA and protein were determined in the amnion of 16 late-gestation ovine fetuses subjected to 2 days of control conditions, urine drainage, urine replacement, or intraamniotic fluid infusion. AQP mRNA levels were determined by RT-qPCR and proteins by western immunoblot. Under control conditions, mRNA levels among the five AQPs differed more than 20-fold. During experimental treatments, mean IMA rate in the experimental groups ranged from 100 ± 120 mL/day to 1370 ± 270 mL/day. The mRNA levels of the five AQPs did not change from control and were not correlated with IMA rates. The protein levels of AQP1 were positively correlated with IMA rates (r(2) = 38%, P = 0.01) while the remaining four AQPs were not. These findings demonstrate that five AQPs are differentially expressed in ovine amnion. Our study supports the hypothesis that AQP1 may play a positive role in regulating the rate of fluid transfer across the amnion, thereby participating in the dynamic regulation of AFV.

  19. Aquaporins in ovine amnion: responses to altered amniotic fluid volumes and intramembranous absorption rates.

    PubMed

    Cheung, Cecilia Y; Anderson, Debra F; Brace, Robert A

    2016-07-01

    Aquaporins (AQPs) are transmembrane channel proteins that facilitate rapid water movement across cell membranes. In amniotic membrane, the AQP-facilitated transfer of water across amnion cells has been proposed as a mechanism for amniotic fluid volume (AFV) regulation. To investigate whether AQPs modulate AFV by altering intramembranous absorption (IMA) rate, we tested the hypothesis that AQP gene expression in the amnion is positively correlated with IMA rate during experimental conditions when IMA rate and AFV are modified over a wide range. The relative abundances of AQP1, AQP3, AQP8, AQP9, and AQP11 mRNA and protein were determined in the amnion of 16 late-gestation ovine fetuses subjected to 2 days of control conditions, urine drainage, urine replacement, or intraamniotic fluid infusion. AQP mRNA levels were determined by RT-qPCR and proteins by western immunoblot. Under control conditions, mRNA levels among the five AQPs differed more than 20-fold. During experimental treatments, mean IMA rate in the experimental groups ranged from 100 ± 120 mL/day to 1370 ± 270 mL/day. The mRNA levels of the five AQPs did not change from control and were not correlated with IMA rates. The protein levels of AQP1 were positively correlated with IMA rates (r(2) = 38%, P = 0.01) while the remaining four AQPs were not. These findings demonstrate that five AQPs are differentially expressed in ovine amnion. Our study supports the hypothesis that AQP1 may play a positive role in regulating the rate of fluid transfer across the amnion, thereby participating in the dynamic regulation of AFV. PMID:27440743

  20. Response of direct thoron progeny sensors (DTPS) to various aerosol concentrations and ventilation rates

    NASA Astrophysics Data System (ADS)

    Mishra, Rosaline; Prajith, R.; Sapra, B. K.; Mayya, Y. S.

    2010-03-01

    Direct thoron/radon progeny sensors (DTPS/DRPS) are absorber mounted LR115 type track detectors for measuring the time-averaged progeny concentrations. Through a large number of experiments, the sensitivity factor of these sensors in natural indoor environment was found to be nearly constant at a value of 0.94 Tr cm -2 d -1/EETC (Bq m -3) for DTPS and 0.09 Tr cm -2 d -1/EERC (Bq m -3) for DRPS. The constancy of the sensitivity factor in the natural environments is attributed primarily to the presence of large aerosol concentrations and relatively low ventilation rates in time-averaged measurements. However, detailed model calculations suggest that in extreme scenario i.e. at high ventilation rate and low aerosol concentrations, the sensitivity factor can be quite different. Such situations are likely to occur in occupational plant areas. Therefore systematic chamber experiments were carried out to using DTPS, to estimate the variability of the sensitivity factor in these extreme conditions. In the first set, the sensitivity factor of DTPS was measured in 6 different aerosol concentrations at zero ventilation rates. The sensitivity factor showed a steep decrease as the aerosol concentration increased to about 8554 particle cm -3, after which it remained almost constant with increase in aerosol concentration. The second set of experiments was conducted at ˜5000 particles cm -3 at three different ventilation rates. The sensitivity factor was found to increase with increase in ventilation rate. The results are further discussed.

  1. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads.

    PubMed

    Natali, J E S; Santos, B T; Rodrigues, V H; Chauí-Berlinck, J G

    2015-01-01

    In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01). These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C.

  2. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads.

    PubMed

    Natali, J E S; Santos, B T; Rodrigues, V H; Chauí-Berlinck, J G

    2014-10-24

    In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01). These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C.

  3. Self-selected intensity, ratings of perceived exertion, and affective responses in sedentary male subjects during resistance training

    PubMed Central

    Elsangedy, Hassan Mohamed; Krinski, Kleverton; Machado, Daniel Gomes da Silva; Agrícola, Pedro Moraes Dutra; Okano, Alexandre Hideki; Gregório da Silva, Sergio

    2016-01-01

    [Purpose] This study examined the exercise intensity and psychophysiological responses to a self-selected resistance training session in sedentary male subjects. [Subjects and Methods] Twelve sedentary male subjects (35.8 ± 5.8 years; 25.5 ± 2.6 kg·m2) underwent four sessions at 48-h intervals: familiarization; two sessions of one repetition maximum test and a resistance training session in which they were told to self-select a load to complete 3 sets of 10 repetitions of chest press, leg press, seated rows, knee extension, overhead press, biceps curl, and triceps pushdown exercises. During the latter, the percentage of one repetition maximum, affective responses (feeling scale), and rating of perceived exertion (OMNI-RES scale) were measured. [Results] The percentage of one repetition maximum for all exercises was >51% (14–31% variability), the rating of perceived exertion was 5–6 (7–11% variability), and the affective responses was 0–1 point with large variability. [Conclusion] Sedentary male subjects self-selected approximately 55% of one maximum repetition, which was above the intensity suggested to increase strength in sedentary individuals, but below the recommended intensity to improve strength in novice to intermediate exercisers. The rating of perceived exertion was indicative of moderate intensity and slightly positive affective responses. PMID:27390418

  4. Self-selected intensity, ratings of perceived exertion, and affective responses in sedentary male subjects during resistance training.

    PubMed

    Elsangedy, Hassan Mohamed; Krinski, Kleverton; Machado, Daniel Gomes da Silva; Agrícola, Pedro Moraes Dutra; Okano, Alexandre Hideki; Gregório da Silva, Sergio

    2016-06-01

    [Purpose] This study examined the exercise intensity and psychophysiological responses to a self-selected resistance training session in sedentary male subjects. [Subjects and Methods] Twelve sedentary male subjects (35.8 ± 5.8 years; 25.5 ± 2.6 kg·m(2)) underwent four sessions at 48-h intervals: familiarization; two sessions of one repetition maximum test and a resistance training session in which they were told to self-select a load to complete 3 sets of 10 repetitions of chest press, leg press, seated rows, knee extension, overhead press, biceps curl, and triceps pushdown exercises. During the latter, the percentage of one repetition maximum, affective responses (feeling scale), and rating of perceived exertion (OMNI-RES scale) were measured. [Results] The percentage of one repetition maximum for all exercises was >51% (14-31% variability), the rating of perceived exertion was 5-6 (7-11% variability), and the affective responses was 0-1 point with large variability. [Conclusion] Sedentary male subjects self-selected approximately 55% of one maximum repetition, which was above the intensity suggested to increase strength in sedentary individuals, but below the recommended intensity to improve strength in novice to intermediate exercisers. The rating of perceived exertion was indicative of moderate intensity and slightly positive affective responses.

  5. The stress response predicts migration failure but not migration rate in a semelparous fish.

    PubMed

    Cook, Katrina V; Crossin, Glenn T; Patterson, David A; Hinch, Scott G; Gilmour, Kathleen M; Cooke, Steven J

    2014-06-01

    Recent findings from iteroparous species suggest that glucocorticoid secretion following acute stress can mediate behavior and survival strategies, ultimately influencing fitness. However, these correlates of the stress response may not exist in semelparous animals given the inability to maximize fitness by delaying reproduction. We measured baseline and stress-induced cortisol concentrations in semelparous sockeye salmon (Oncorhynchus nerka) following exposure to an acute stressor at the mouth of the Fraser River in British Columbia. The homing fish were then radio-tagged and tracked throughout their in-river migration. Findings reveal that the stress response (i.e. change from baseline to stress-induced cortisol) was predictive of mortality; fish failing to leave the release site had a significantly greater stress response (mean±SE=1004.0±75.3ng/mL) compared to fish capable of successfully migrating beyond one of the most difficult areas of passage over 100 river kilometers upstream (mean±SE=780.7±66.7ng/mL). However, there were no associations between swimming behaviors, both immediately following release and to last point of detection, and the stress response. This study also introduced an unique method of tagging migrating salmon that allows for rapid capture and sampling and thus provides the first assessment of true baseline cortisol concentrations at river-entry for migrating Pacific salmon in the wild. Results show the stress response to be linked to survival in a semelparous species and therefore set the stage for further exploration into how the evolutionary theories underlying relationships between stress responsiveness and fitness may differ between semelparous and iteroparous species. PMID:24769043

  6. Nonlinear dynamics of heart rate variability in response to orthostatism and hemodialysis in chronic renal failure patients: recurrence analysis approach.

    PubMed

    González, Hortensia; Infante, Oscar; Pérez-Grovas, Héctor; Jose, Marco V; Lerma, Claudia

    2013-02-01

    We studied the response of heart rate variability to hemodialysis and orthostatism using traditional linear indexes and 9 recurrence quantification analysis indexes to reveal changes in the heart rate dynamics. Twenty healthy subjects and 19 chronic renal failure patients treated with hemodialysis thrice a week were included. Five-minute heart rate variability time series were obtained during supine position (clinostatism) and orthostatism from each participant; recordings in renal patients were repeated after hemodialysis. Linear indexes were consistent with sympathetic predominance in response to orthostatism in the control group. Renal patients before hemodialysis showed increased sympathetic predominance in clinostatism, with further increase in orthostatism and hemodialysis. In response to orthostatism, 4 recurrence indexes changed in the control group, while in renal patients any of them changed before hemodialysis and 1 changed after hemodialysis. In clinostatism, renal patients (both before and after hemodialysis) had higher laminarity, trapping time, and recurrence time than the control group. Recurrence indexes showed that the heart rate dynamics in renal patients are different from healthy subjects, suggesting loss of access to some regulatory conditions. These findings are consistent with reports of sympathetic stimulation induced by hemodialysis and active standing.

  7. Basal and maximal metabolic rates differ in their response to rapid temperature change among avian species.

    PubMed

    Dubois, Karine; Hallot, Fanny; Vézina, François

    2016-10-01

    In birds, acclimation and acclimatization to temperature are associated with changes in basal (BMR), summit (Msum) and maximal (MMR) metabolic rates but little is known about the rate at which species adjust their phenotype to short-term temperature variations. Our aims were (1) to determine the pattern of metabolic adjustments following a rapid temperature change, (2) to determine whether performance varies at similar rates during exposure to warm or cold environments, and (3) to determine if BMR, Msum and MMR change at comparable rates during thermal acclimation. We measured these parameters in white-throated sparrows (Zonotrichia albicollis), black-capped chickadees (Poecile atricapillus), and snow buntings (Plectrophenax nivalis) after acclimation to 10 °C (day 0) and on the 4th and 8th days of acclimation to either -5 or 28 °C. Birds changed their metabolic phenotype within 8 days with patterns differing among species. Sparrows expressed the expected metabolic increases in the cold and decreases at thermoneutrality while performance in chickadees and buntings was not influenced by temperature but changed over time with inverse patterns. Our results suggest that BMR varies at comparable rates in warm and cold environments but changes faster than Msum and MMR, likely due to limitations in the rate of change in organ size and function. They also suggest that maximal metabolic capacity is lost faster in a warm environment than it is gained in a cold environment. With the expected increase in temperature stochasticity at northern latitudes, a loss of thermogenic capacity during warm winter days could, therefore, be detrimental if birds are slow to readjust their phenotype with the return of cold days.

  8. Formation of volcanic edifices in response to changes in magma budget at intermediate spreading rate ridges

    NASA Astrophysics Data System (ADS)

    Howell, J.; White, S. M.; Bohnenstiehl, D. R.; Bizimis, M.

    2010-12-01

    The spatial and abundance distributions of volcanic edifices along mid-ocean ridges have a well known correlation with spreading rate. Along slow spreading centers, volcanic edifices are normally distributed about the segment center. Volcanic edifices along fast spreading centers have the opposing trend, i.e. edifices form primarily at the ends of segments. However, in ridges affected by plumes and at back arc basins, the spatial and abundance distributions of volcanic edifices differ from that observed at normal ridges of the same spreading rate. This suggests that magma supply rate may control the spatial and abundance distribution of volcanic edifices. Recent geophysical and geochemical studies along the Galapagos Spreading Centers (GSC), Juan de Fuca Ridge (JdFR), Southeast Indian Ridge (SEIR) and the Valu Fa (VF) and Eastern Lau Spreading Centers (ELSC) put tight constraints on crustal thickness, making it possible investigate the effect of magma budget and axial morphology on the formation of volcanic edifices. Volcanic edifices are described according to their volume, shape (their height to basal radius ratio) and their location relative to the end or center of a segment (abundance distribution). For the GSC, the shape and distribution of volcanic edifices correlate with changes in crustal thickness and axial morphology, consistent with a magma supply control on their formation in this region. This relationship is not apparent along the SEIR or JdFR, where edifices show little variation with changes in axial morphology at relatively constant spreading rates. Results for VF and ELSC are what we expect for changes in spreading rate, not axial morphology. Our study suggests that the formation of volcanic edifices at intermediate spreading rate ridges are influenced by magma budget but only when it is above a certain threshold.

  9. Basal and maximal metabolic rates differ in their response to rapid temperature change among avian species.

    PubMed

    Dubois, Karine; Hallot, Fanny; Vézina, François

    2016-10-01

    In birds, acclimation and acclimatization to temperature are associated with changes in basal (BMR), summit (Msum) and maximal (MMR) metabolic rates but little is known about the rate at which species adjust their phenotype to short-term temperature variations. Our aims were (1) to determine the pattern of metabolic adjustments following a rapid temperature change, (2) to determine whether performance varies at similar rates during exposure to warm or cold environments, and (3) to determine if BMR, Msum and MMR change at comparable rates during thermal acclimation. We measured these parameters in white-throated sparrows (Zonotrichia albicollis), black-capped chickadees (Poecile atricapillus), and snow buntings (Plectrophenax nivalis) after acclimation to 10 °C (day 0) and on the 4th and 8th days of acclimation to either -5 or 28 °C. Birds changed their metabolic phenotype within 8 days with patterns differing among species. Sparrows expressed the expected metabolic increases in the cold and decreases at thermoneutrality while performance in chickadees and buntings was not influenced by temperature but changed over time with inverse patterns. Our results suggest that BMR varies at comparable rates in warm and cold environments but changes faster than Msum and MMR, likely due to limitations in the rate of change in organ size and function. They also suggest that maximal metabolic capacity is lost faster in a warm environment than it is gained in a cold environment. With the expected increase in temperature stochasticity at northern latitudes, a loss of thermogenic capacity during warm winter days could, therefore, be detrimental if birds are slow to readjust their phenotype with the return of cold days. PMID:27233918

  10. Public acceptance of management actions and judgments of responsibility for the wolves of the southern Greater Yellowstone Area: Report to Grand Teton National Park

    USGS Publications Warehouse

    Taylor, Jonathan G.; Johnson, S. Shea; Shelby, Lori B.

    2005-01-01

    . After delisting, state Fish and Wildlife Services in Montana, Idaho, and Wyoming will be responsible for managing wolves. Each state must submit a wolf management plan to the USFWS which then must be approved before management shifts occur. As of this writing, the process of delisting the wolves in the state of Wyoming is ongoing. However, the reclassification of wolves nationwide was completed on April 1, 2003. Wolves outside of YNP changed in status from endangered to threatened. The wolves classified in the experimental nonessential population did not change in status (USFWS and others, 2004). This classification of experimental nonessential population allows for flexibility in management decisions concerning the wolves (Smith and others, 2004). For example, control actions in the GYA included trapping and radio-collaring four wolves; intensive monitoring; increasing riders on grazing allotments; harassing wolves with rubber bullets, cracker shells, and lights; moving livestock to different pastures; and issuing four shoot on-sight permits. When non-lethal control methods were not effective, wolves were killed in an attempt to prevent further livestock depredations (USFWS and others, 2004; Table 1). At the same time that wolf numbers are rising, human population statistics in the GRTE area are also rising. The population of Teton County, Wyoming in 1990 was just over 11,000 people; today that number has increased to approximately 19,000 (U.S. Census Bureau, 2005). park visitation for GRTE has been substantial over the last several years with an average visitation of 2.5 million visitors (NPS, 2004a). Furthermore, land ownership surrounding GRTE and the establishment of grazing rights within park boundaries are problem areas for wolf-human interactions due to livestock depredation. With increasing numbers of visitors, residents, and livestock it is reasonable to assume that conflicts are going to increase also. In 1950, GRTE was expanded to in

  11. Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus.

    PubMed

    Viblanc, Vincent A; Smith, Andrew D; Gineste, Benoit; Kauffmann, Marion; Groscolas, René

    2015-06-01

    'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds. PMID:25883375

  12. Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus.

    PubMed

    Viblanc, Vincent A; Smith, Andrew D; Gineste, Benoit; Kauffmann, Marion; Groscolas, René

    2015-06-01

    'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds.

  13. Onset and Maturation of Fetal Heart Rate Response to the Mother's Voice over Late Gestation

    ERIC Educational Resources Information Center

    Kisilevsky, Barbara S.; Hains, Sylvia M. J.

    2011-01-01

    Background: Term fetuses discriminate their mother's voice from a female stranger's, suggesting recognition/learning of some property of her voice. Identification of the onset and maturation of the response would increase our understanding of the influence of environmental sounds on the development of sensory abilities and identify the period when…

  14. Effects of Peer versus Computer-Assisted Drill on Mathematics Response Rates

    ERIC Educational Resources Information Center

    Cates, Gary L.

    2005-01-01

    This study investigated the functional relationship between student accurate response levels and two mathematics drill procedures using a BCBC across participant's single case research design (in this case, "B" represents peer drill and "C" represents computer drill). Each of four elementary school students was randomly assigned to one of two…

  15. Response of a coupled ocean-atmosphere model to increasing atmospheric carbon dioxide: Sensitivity to the rate of increase

    SciTech Connect

    Stouffer, R.J.

    1999-08-01

    The influence of differing rates of increase of the atmospheric CO{sub 2} concentration on the climatic response is investigated using a coupled ocean-atmosphere model. Five transient integrations are performed each using a different constant exponential rate of CO{sub 2} increase ranging from 4% yr{sup {minus}1} to 0.25% yr{sup {minus}1}. By the time of CO{sub 2} doubling, the surface air temperature response in all the transient integrations is locally more than 50% and globally more than 35% of the equilibrium response. The land-sea contrast in the warming, which is evident in the equilibrium results, is larger in all the transient experiments. The land-sea difference in the response increases with the rate of increase in atmospheric CO{sub 2} concentration. The thermohaline circulation (THC) weakens in response to increasing atmospheric CO{sub 2} concentration in all the transient integrations, confirming earlier work. The results also indicate that the slower the rate of increase, the larger the weakening of the THC by the time of doubling. Two of the transient experiments are continued beyond the time of CO{sub 2} doubling with the CO{sub 2} concentration maintained at that level. The amount of weakening of the THC after the CO{sub 2} stops increasing is smaller in the experiment with the slower rate of CO{sub 2} increase, indicating that the coupled system has more time to adjust to the forcing when the rate of CO{sub 2} increase is slower. After a period of slow overturning, the THC gradually recovers and eventually regains the intensity found in the control integration, so that the equilibrium THC is very similar in the control and doubled CO{sub 2} integrations. Considering only the sea level changes due to the thermal expansion of seawater, the integration with the slowest rate of increase in CO{sub 2} concentration has the largest globally averaged sea level rise by the time of CO{sub 2} doubling. However, only a relatively small fraction of the

  16. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Patterson, R. M.; Wade, C. E.; Byers, F. M.

    2000-01-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  17. Association of ventilation rates and CO2 concentrations with health and other responses in commercial and institutional buildings.

    PubMed

    Seppänen, O A; Fisk, W J; Mendell, M J

    1999-12-01

    This paper reviews current literature on the associations of ventilation rates and carbon dioxide concentrations in non-residential and non-industrial buildings (primarily offices) with health and other human outcomes. Twenty studies, with close to 30,000 subjects, investigated the association of ventilation rates with human responses, and 21 studies, with over 30,000 subjects, investigated the association of carbon dioxide concentration with these responses. Almost all studies found that ventilation rates below 10 Ls-1 per person in all building types were associated with statistically significant worsening in one or more health or perceived air quality outcomes. Some studies determined that increases in ventilation rates above 10 Ls-1 per person, up to approximately 20 Ls-1 per person, were associated with further significant decreases in the prevalence of sick building syndrome (SBS) symptoms or with further significant improvements in perceived air quality. The carbon dioxide studies support these findings. About half of the carbon dioxide studies suggest that the risk of sick building syndrome symptoms continued to decrease significantly with decreasing carbon dioxide concentrations below 800 ppm. The ventilation studies reported relative risks of 1.5-2 for respiratory illnesses and 1.1-6 for sick building syndrome symptoms for low compared to high low ventilation rates. PMID:10649857

  18. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi).

    PubMed

    Ortiz, R M; Patterson, R M; Wade, C E; Byers, F M

    2000-09-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  19. RATE OF ACCLIMATION OF THE CAPACITY FOR ISOPRENE EMISSION IN RESPONSE TO LIGHT AND TEMPERATURE

    EPA Science Inventory

    Isoprene emission from plants accounts for nearly half of all non-methane hydrocarbons entering the atmosphere. Light and temperature regulate the instantaneous rate of isoprene emission, but there is increasing evidence that they also affect the capacity for isoprene emission (i...

  20. Community College Responses to Calls for Higher Completion Rates: The Cases of Three Community Colleges

    ERIC Educational Resources Information Center

    Smock, Elizabeth S.

    2013-01-01

    The primary purpose of this study was to understand how three diverse community colleges are interpreting and acting on federal initiatives to increase completion rates. The study attempted to answer four main research questions: (1) How do a selection of Kansas community colleges, as organizations, interpret the initiative to increase completion…

  1. Sensory Constraints on Birdsong Syntax: Neural Responses to Swamp Sparrow Songs with Accelerated Trill Rates.

    PubMed

    Prather, Jf; Peters, S; Mooney, R; Nowicki, S

    2012-06-01

    Both sensory and motor mechanisms can constrain behavioral performance. Sensory mechanisms may be especially important for constraining behaviors that depend on experience, such as learned birdsongs. Swamp sparrows learn to sing by imitating the song of a tutor, but sparrows fail to accurately imitate artificial tutor songs with abnormally accelerated trills, instead singing brief and rapid trills interrupted by silent gaps. This "broken syntax" has been proposed to arise from vocal-motor limitations. Here we consider whether sensory limitations exist that could also contribute to broken syntax. We tested this idea by recording auditory-evoked activity of sensorimotor neurons in the swamp sparrow's brain that are known to be important for the learning, performance and perception of song. In freely behaving adult sparrows that sang songs with normal syntax, neurons were detected that exhibited precisely time-locked activity to each repetition of the syllable in a trill when presented at a natural rate. Those cells failed to faithfully follow syllables presented at an accelerated rate, however, and their failure to respond to consecutive syllables increased as a function of trill rate. This "flickering" auditory representation in animals performing normal syntax reveals a central constraint on the sensory processing of rapid trills. Furthermore, because these neurons are implicated in both song learning and perception, and because auditory flickering began to occur at accelerated trill rates previously associated with the emergence of broken song syntax, these sensory constraints may contribute to the emergence of broken syntax.

  2. Response of seed tocopherols in oilseed rape to nitrogen fertilizer sources and application rates.

    PubMed

    Hussain, Nazim; Li, Hui; Jiang, Yu-xiao; Jabeen, Zahra; Shamsi, Imran Haider; Ali, Essa; Jiang, Li-xi

    2014-02-01

    Tocopherols (Tocs) are vital scavengers of reactive oxygen species (ROS) and important seed oil quality indicators. Nitrogen (N) is one of the most important fertilizers in promoting biomass and grain yield in crop production. However, the effect of different sources and application rates of N on seed Toc contents in oilseed rape is poorly understood. In this study, pot trials were conducted to evaluate the effect of two sources of N fertilizer (urea and ammonium nitrate). Each source was applied to five oilseed rape genotypes (Zheshuang 72, Jiu-Er-1358, Zheshuang 758, Shiralee, and Pakola) at three different application rates (0.41 g/pot (N1), 0.81 g/pot (N2), and 1.20 g/pot (N3)). Results indicated that urea increased α-, γ-, and total Toc (T-Toc) more than did ammonium nitrate. N3 was proven as the most efficient application rate, which yielded high contents of γ-Toc and T-Toc. Highly significant correlations were observed between Toc isomers, T-Toc, and α-/γ-Toc ratio. These results clearly demonstrate that N sources and application rates significantly affect seed Toc contents in oilseed rape. PMID:24510711

  3. Sensory Constraints on Birdsong Syntax: Neural Responses to Swamp Sparrow Songs with Accelerated Trill Rates.

    PubMed

    Prather, Jf; Peters, S; Mooney, R; Nowicki, S

    2012-06-01

    Both sensory and motor mechanisms can constrain behavioral performance. Sensory mechanisms may be especially important for constraining behaviors that depend on experience, such as learned birdsongs. Swamp sparrows learn to sing by imitating the song of a tutor, but sparrows fail to accurately imitate artificial tutor songs with abnormally accelerated trills, instead singing brief and rapid trills interrupted by silent gaps. This "broken syntax" has been proposed to arise from vocal-motor limitations. Here we consider whether sensory limitations exist that could also contribute to broken syntax. We tested this idea by recording auditory-evoked activity of sensorimotor neurons in the swamp sparrow's brain that are known to be important for the learning, performance and perception of song. In freely behaving adult sparrows that sang songs with normal syntax, neurons were detected that exhibited precisely time-locked activity to each repetition of the syllable in a trill when presented at a natural rate. Those cells failed to faithfully follow syllables presented at an accelerated rate, however, and their failure to respond to consecutive syllables increased as a function of trill rate. This "flickering" auditory representation in animals performing normal syntax reveals a central constraint on the sensory processing of rapid trills. Furthermore, because these neurons are implicated in both song learning and perception, and because auditory flickering began to occur at accelerated trill rates previously associated with the emergence of broken song syntax, these sensory constraints may contribute to the emergence of broken syntax. PMID:23976787

  4. Sensory Constraints on Birdsong Syntax: Neural Responses to Swamp Sparrow Songs with Accelerated Trill Rates

    PubMed Central

    Prather, JF; Peters, S; Mooney, R; Nowicki, S

    2013-01-01

    Both sensory and motor mechanisms can constrain behavioral performance. Sensory mechanisms may be especially important for constraining behaviors that depend on experience, such as learned birdsongs. Swamp sparrows learn to sing by imitating the song of a tutor, but sparrows fail to accurately imitate artificial tutor songs with abnormally accelerated trills, instead singing brief and rapid trills interrupted by silent gaps. This “broken syntax” has been proposed to arise from vocal-motor limitations. Here we consider whether sensory limitations exist that could also contribute to broken syntax. We tested this idea by recording auditory-evoked activity of sensorimotor neurons in the swamp sparrow’s brain that are known to be important for the learning, performance and perception of song. In freely behaving adult sparrows that sang songs with normal syntax, neurons were detected that exhibited precisely time-locked activity to each repetition of the syllable in a trill when presented at a natural rate. Those cells failed to faithfully follow syllables presented at an accelerated rate, however, and their failure to respond to consecutive syllables increased as a function of trill rate. This “flickering” auditory representation in animals performing normal syntax reveals a central constraint on the sensory processing of rapid trills. Furthermore, because these neurons are implicated in both song learning and perception, and because auditory flickering began to occur at accelerated trill rates previously associated with the emergence of broken song syntax, these sensory constraints may contribute to the emergence of broken syntax. PMID:23976787

  5. Measurement Differences from Rating Posttraumatic Stress Disorder Symptoms in Response to Differentially Distressing Traumatic Events

    ERIC Educational Resources Information Center

    Elhai, Jon D.; Fine, Thomas H.

    2012-01-01

    The authors explored differences in posttraumatic stress disorder (PTSD) symptoms as a result of rating symptoms from two separate, differentially distressing traumatic events. In an initial sample of 400 nonclinical participants, the authors inquired through a web survey about previous psychological trauma, instructing participants to nominate…

  6. Global stability for an HIV-1 infection model with Beddington-DeAngelis incidence rate and CTL immune response

    NASA Astrophysics Data System (ADS)

    Lv, Cuifang; Huang, Lihong; Yuan, Zhaohui

    2014-01-01

    In this paper, an HIV-1 infection model with Beddington-DeAngelis incidence rate and CTL immune response is investigated. One main feature of this model is that an eclipse stage for the infected cells is included and a portion of these cells is reverted to uninfected cells. We derive the basic reproduction number R1 and the immune response reproduction number R2 for the HIV-1 infection model. By constructing Lyapunov functions, the global stabilities for the equilibria have been analyzed.

  7. Feasibility demonstration of a variable frequency driver-microwave transient regression rate measurement system. [for solid propellant combustion response

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Mcnamara, R. P.

    1976-01-01

    The feasibility of a system capable of rapidly and directly measuring the low-frequency (motor characteristics length bulk mode) combustion response characteristics of solid propellants has been investigated. The system consists of a variable frequency oscillatory driver device coupled with an improved version of the JPL microwave propellant regression rate measurement system. The ratio of the normalized regression rate and pressure amplitudes and their relative phase are measured as a function of varying pressure level and frequency. Test results with a well-characterized PBAN-AP propellant formulation were found to compare favorably with the results of more conventional stability measurement techniques.

  8. Heart rate and heart rate variability assessment identifies individual differences in fear response magnitudes to earthquake, free fall, and air puff in mice.

    PubMed

    Liu, Jun; Wei, Wei; Kuang, Hui; Tsien, Joe Z; Zhao, Fang

    2014-01-01

    Fear behaviors and fear memories in rodents have been traditionally assessed by the amount of freezing upon the presentation of conditioned cues or unconditioned stimuli. However, many experiences, such as encountering earthquakes or accidental fall from tree branches, may produce long-lasting fear memories but are behaviorally difficult to measure using freezing parameters. Here, we have examined changes in heartbeat interval dynamics as physiological readout for assessing fearful reactions as mice were subjected to sudden air puff, free-fall drop inside a small elevator, and a laboratory-version earthquake. We showed that these fearful events rapidly increased heart rate (HR) with simultaneous reduction of heart rate variability (HRV). Cardiac changes can be further analyzed in details by measuring three distinct phases: namely, the rapid rising phase in HR, the maximum plateau phase during which HRV is greatly decreased, and the recovery phase during which HR gradually recovers to baseline values. We showed that durations of the maximum plateau phase and HR recovery speed were quite sensitive to habituation over repeated trials. Moreover, we have developed the fear resistance index based on specific cardiac response features. We demonstrated that the fear resistance index remained largely consistent across distinct fearful events in a given animal, thereby enabling us to compare and rank individual mouse's fear responsiveness among the group. Therefore, the fear resistance index described here can represent a useful parameter for measuring personality traits or individual differences in stress-susceptibility in both wild-type mice and post-traumatic stress disorder (PTSD) models.

  9. Heart Rate and Heart Rate Variability Assessment Identifies Individual Differences in Fear Response Magnitudes to Earthquake, Free Fall, and Air Puff in Mice

    PubMed Central

    Kuang, Hui; Tsien, Joe Z.; Zhao, Fang

    2014-01-01

    Fear behaviors and fear memories in rodents have been traditionally assessed by the amount of freezing upon the presentation of conditioned cues or unconditioned stimuli. However, many experiences, such as encountering earthquakes or accidental fall from tree branches, may produce long-lasting fear memories but are behaviorally difficult to measure using freezing parameters. Here, we have examined changes in heartbeat interval dynamics as physiological readout for assessing fearful reactions as mice were subjected to sudden air puff, free-fall drop inside a small elevator, and a laboratory-version earthquake. We showed that these fearful events rapidly increased heart rate (HR) with simultaneous reduction of heart rate variability (HRV). Cardiac changes can be further analyzed in details by measuring three distinct phases: namely, the rapid rising phase in HR, the maximum plateau phase during which HRV is greatly decreased, and the recovery phase during which HR gradually recovers to baseline values. We showed that durations of the maximum plateau phase and HR recovery speed were quite sensitive to habituation over repeated trials. Moreover, we have developed the fear resistance index based on specific cardiac response features. We demonstrated that the fear resistance index remained largely consistent across distinct fearful events in a given animal, thereby enabling us to compare and rank individual mouse’s fear responsiveness among the group. Therefore, the fear resistance index described here can represent a useful parameter for measuring personality traits or individual differences in stress-susceptibility in both wild-type mice and post-traumatic stress disorder (PTSD) models. PMID:24667366

  10. Influence of Antecedent Moisture and Rainfall Rate on the Hydrologic Response of and Nitrate Leaching from Intact Soil Monoliths

    NASA Astrophysics Data System (ADS)

    Lewis, M. P.; Macrae, M. L.; Bourbonniere, R. A.

    2009-05-01

    The transfer of excess nitrate from agricultural soil during and following rainfall events is a major environmental problem in many regions worldwide. Although field and modelling studies have linked discharge and nutrient export from catchments to spatial variables such as soil type and agricultural management practices, less is known about temporal variability in nutrient export. Several field studies have shown that the hydrologic response of catchments to storm events differs with variable antecedent soil moisture conditions as well as storm type/rainfall rate. Variable hydrologic responses are in turn, expected to affect the export of nutrients such as nitrate from agricultural landscapes. This research uses an experimental approach to characterize the combined influence of antecedent soil moisture and rainfall rate on runoff quantity and quality from agricultural soil. Two sets of experiments were performed on large, intact soil monoliths in a laboratory setting, where soil monoliths were subject to three moisture treatments (dry, moist, wet/field capacity) and two different rainfall simulations (2.5mm/h and 20.5mm/h). Under high rainfall rates, nitrate export for the event ranged from 1125mg m-2 (wet soil) to 81.5mg m-2 (dry soil) and ranged from 1053mg m-2 (wet soil) to 429.1mg m-2 (dry soil) under low rainfall rates. Antecedent moisture conditions had a greater effect on the depth of runoff and the total mass of nitrate leached than rainfall rate, with wetter soils producing more runoff (runoff ratios = 0.37, 0.33, respectively for the 2.5mm/h and 20.5mm/h events) and causing more nitrate export (1125 and 1053 mg m-2 event-1) than dry soil (runoff ratios = 0.033 and 0.105; nitrate export = 89.2, 429.1 mg m-2 event-1). The soil moisture response and the progression of the wetting front occurred earliest in wet soil and latest in dry soil, as illustrated by runoff volumes and soil moisture profiles recorded throughout both rainfall simulations. Patterns

  11. Left ventricular assist device weaning: hemodynamic response and relationship to stroke volume and rate reduction protocols.

    PubMed

    Slaughter, Mark S; Sobieski, Michael A; Koenig, Steven C; Pappas, Patrokolos S; Tatooles, Antone J; Silver, Marc A

    2006-01-01

    Clinical evidence of myocardial recovery in a small cohort of patients supported with a left ventricular assist device (LVAD) has been reported. Development of an optimal LVAD weaning protocol is needed for these patients to sustain recovery after device explant. In this study, we tested the hypothesis that LVAD stroke volume reduction produces a steady-state mechanical reloading of left ventricular (LV) pressures and volumes compared with LVAD rate reduction that results in transient mechanical reloading of the heart due to beat-to-beat variation in LV pressures and volumes. The relationship of LVAD flow to LVAD stroke volume and systolic interval over a range of LVAD rates (60, 80, 100, 120, and 140 bpm) was validated in a mock circulatory flow loop. In six acute experiments, calves were implanted with a pneumatic paracorporeal LVAD (PVAD, Thoratec, Pleasanton, CA). The PVAD was operated asynchronously in the auto volume mode (full decompression) for 30 minutes to establish a baseline control condition. The calf hearts were then mechanically reloaded by LVAD rate reduction (80, 60, and 40 bpm) or LVAD stroke volume reduction (100, 120, and 140 bpm) protocols consisting of 30 minutes of support at each LVAD beat rate. The order of weaning protocols was randomized with a 30-minute recovery period (LVAD volume mode to fully decompress heart allowing it to rest) between protocols to enable return to baseline control state. Aortic pressure and flow, LV pressure and volume, pulmonary artery flow, and LVAD flow waveforms were recorded for each test condition. The LVAD stroke volume reduction protocol produced steady-state mechanical reloading compared with VAD rate reduction that resulted in transient LV mechanical reloading. This distinction is due to differences in their temporal relationships between LVAD and LV filling and emptying cycles. The acute hemodynamic benefit of LVAD stroke volume reduction was greater reduction in LV end-diastolic pressure and increase in

  12. Growth rate responses of Missouri and lower Yellowstone river fishes to a latitudinal gradient

    USGS Publications Warehouse

    Pegg, M.A.; Pierce, C.L.

    2001-01-01

    Growth rate coefficients estimated for channel catfish Ictalurus punctatus, emerald shiners Notropis atherinoides, freshwater drums Aplodinotus grunniens, river carpsuckers Carpiodes carpio and saugers Stizostedion canadense collected in 1996-1998 from nine river sections of the Missouri and lower Yellowstone rivers at two life-stages (young-of-the-year and age 1 + years) were significantly different among sections. However, they showed no river-wide latitudinal trend except for age 1 + years emerald shiners that did show a weak negative relation between growth and both latitude and length of growing season. The results suggest growth rates of fishes along the Missouri River system are complex and could be of significance in the management and conservation of fish communities in this altered system. ?? 2001 The Fisheries Society of the British Isles.

  13. THEORETICAL ANALYSIS OF THE TRANSIENT PRESSURE RESPONSE FROM A CONSTANT FLOW RATE HYDRAULIC CONDUCTIVITY TEST.

    USGS Publications Warehouse

    Morin, Roger H.; Olsen, Harold W.

    1987-01-01

    Incorporating a flow pump into a conventional triaxial laboratory system allows fluid to be supplied to or withdrawn from the base of a sediment sample at small and constant rates. An initial transient record of hydraulic head versus time is observed which eventually stabilizes to a constant steady state gradient across the sample; values of hydraulic conductivity can subsequently be determined from Darcy's law. In this paper, analytical methods are presented for determining values of specific storage and hydraulic conductivity from the initial transient phase of such a constant flow rate test. These methods are based on a diffusion equation involving pore pressure and are analogous to those used to describe the soil consolidation process and also to interpret aquifer properties from pumping tests.

  14. Response to Comment on "Mutation rate and genotype variation of Ebola virus from Mali case sequences".

    PubMed

    Hoenen, Thomas; Groseth, Allison; Safronetz, David; Wollenberg, Kurt; Feldmann, Heinz

    2016-08-12

    Rambaut et al show that the erratum to our report on Ebola virus Makona evolution not only corrected sample dates modified by others in GenBank but also corrected an additional transcriptional error in our original analysis. We agree with their observation that both factors contributed to our revised evolutionary rate estimate but continue to stand by our revised estimate and conclusions. PMID:27516593

  15. Amplifying the sensitivity of zinc(II) responsive MRI contrast agents by altering water exchange rates.

    PubMed

    Yu, Jing; Martins, André F; Preihs, Christian; Clavijo Jordan, Veronica; Chirayil, Sara; Zhao, Piyu; Wu, Yunkou; Nasr, Khaled; Kiefer, Garry E; Sherry, A Dean

    2015-11-11

    Given the known water exchange rate limitations of a previously reported Zn(II)-sensitive MRI contrast agent, GdDOTA-diBPEN, new structural targets were rationally designed to increase the rate of water exchange to improve MRI detection sensitivity. These new sensors exhibit fine-tuned water exchange properties and, depending on the individual structure, demonstrate significantly improved longitudinal relaxivities (r1). Two sensors in particular demonstrate optimized parameters and, therefore, show exceptionally high longitudinal relaxivities of about 50 mM(-1) s(-1) upon binding to Zn(II) and human serum albumin (HSA). This value demonstrates a 3-fold increase in r1 compared to that displayed by the original sensor, GdDOTA-diBPEN. In addition, this study provides important insights into the interplay between structural modifications, water exchange rate, and kinetic stability properties of the sensors. The new high relaxivity agents were used to successfully image Zn(II) release from the mouse pancreas in vivo during glucose stimulated insulin secretion. PMID:26462412

  16. The effect of water flow rate upon the environmentally-assisted cracking response of a low-alloy steel

    SciTech Connect

    James, L.A.; Wire, G.L.; Cullen, W.H.

    1994-09-01

    Effect of water flow rate on the environmentally-assisted cracking (EAC) response of a high-sulfur ferritic steel was studied at 243C. In contrast to earlier studies with compact-type specimens, this study employed relatively large tight semi-elliptical surface cracks tested under generally linear-elastic conditions. Flow velocities parallel to the crack as low as 1.68 {minus} 1.84 m/s were effective in mitigating EAC.

  17. Integrated Forecasts of the Response to Change in Rates of Sea-level Rise in Coastal North Carolina

    NASA Astrophysics Data System (ADS)

    Howell, S.; Furbish, D. J.; Mudd, S. M.

    2008-12-01

    The long-term stability of tidal marshes is related to the feedbacks between surface slope, sedimentation, primary production, and the relative rate of sea level rise. Global sea-level over the past 100 years has risen at a rate of 1 to 2 mm/yr. The entire marsh environment exists within less than a meter of relief near high tide. This research has three parts aimed at understanding the fundamental physics and coupling of the physical and ecological responses to sea-level rise, engineered structures, and climate change. The study sites are located at Bogue Banks and Cedar Island, North Carolina. The first component is focused on understanding how macrophytes trap sediment; this includes monitoring inundation duration and frequency for semi-diurnal and wind driven tides. The second part considers deep time using analytical and numerical methods to simulate the effect of changing rates of sea level rise and sediment supply on the stratigraphy and carbon accumulation in a coastal salt marsh. Simulations also explore the effects of organic decomposition on marsh accretion rates. The third component deals with the human response to sea-level rise by engineering the shoreline using soft stabilization. We are developing a method to examine the geomorphic response to engineered structures, in particular the use of oyster shells and marsh transplants, to determine the degree of protection, response times, and indirect impacts. This comprehensive approach to gathering field data and development of modeling schemes provides resource managers with tools as well as a systematic monitoring methodology.

  18. Age and Acceptance of Euthanasia.

    ERIC Educational Resources Information Center

    Ward, Russell A.

    1980-01-01

    Study explores relationship between age (and sex and race) and acceptance of euthanasia. Women and non-Whites were less accepting because of religiosity. Among older people less acceptance was attributable to their lesser education and greater religiosity. Results suggest that quality of life in old age affects acceptability of euthanasia. (Author)

  19. Uncertainty quantification for the impact of injection rate fluctuation on the geomechanical response of geological carbon sequestration

    SciTech Connect

    Bao, Jie; Chu, Yanjun; Xu, Zhijie; Tartakovsky, Alexandre M.; Fang, Yilin

    2014-01-01

    We present an analysis of the geomechanical effects of injection rate fluctuations for geological sequestration of carbon dioxide (CO2). Initially, we present analytical solutions for the effects of injection rate fluctuations on CO2 fluid pressure spatial distribution and temporal evolution for a typical injection scenario. Numerical calculations are performed using a finite element method to investigate the effects of injection rate fluctuations on geomechanical deformation, stresses, and potential failure of the aquifer and caprock layers. The numerical method was first validated by the fluid pressure distribution’s good agreement with the analytical solution. It was shown that for any Gaussian fluctuations of injection rate Q with given mean Q and variance ε_Q, the coefficients of variance for fluid pressure (ϵ_p=ε_p ), deformation (ϵ_u=ε_u ), and stresses (ϵ_σ=ε_σ ) increase linearly with the coefficient of variance for injection rate (ϵ_Q=ε_Q ). The proportional constants are identified, and the fluctuations have the most pronounced effect on the geomechanical stresses, and, therefore, on the potential failure of the aquifer and caprock layers. Instead of expensive computational simulation, this study provides an efficient tool to estimate the geomechanical response variance to injection rate fluctuation. A failure analysis was presented based on the numerical results, where probability of failure was estimated for fluctuating injection rates with different mean and variance during the entire injection period. It was found that with increasing injection rate fluctuation, the failure probability increases significantly. Therefore, the risk associated with injection rate fluctuations should be carefully evaluated.

  20. Analysis of the dynamic and steady-state responses of growth rate and turgor pressure to changes in cell parameters.

    PubMed

    Cosgrove, D J

    1981-12-01

    The physical analysis of plant cell enlargment is extended to show the dependence of turgor pressure and growth rate under steady-state conditions on the parameters which govern cell wall extension and water transport in growing cells and tissues, and to show the dynamic responses of turgor and growth rate to instantaneous changes in one of these parameters. The analysis is based on the fact that growth requires simultaneous water uptake and irreversible wall expansion. It shows that when a growing cell is perturbed from its steady-state growth rate, it will approach the steady-state rate with exponential kinetics. The half-time of the transient adjustment depends on the biophysical parameters governing both water transport and irreversible wall expansion. When wall extensibility is small compared to hydraulic conductance, the growth rate is controlled by the yielding properties of the cell wall, while the half-time for changes in growth rate is controlled by the water transport parameters. The reverse situation occurs when hydraulic conductance is lower than wall extensibility. The analysis also shows explicitly that turgor pressure is tightly coupled with growth rate when growth is controlled by both water transport and wall yielding parameters.In growing tissue where the resistance to water flow is distributed throughout the tissue, the physical analysis is more complicated because gradients in water potential (and hence turgor pressure) are required to sustain high growth rates. However, the analysis of growth in such tissues shows that the turgor and time-course relations are similar to that in single cells. These turgor and time-course relations provide experimentally useful ways for determining (a) whether growth is limited by water uptake, and (b) whether an agent which alters the growth rate does so by affecting the water transport or wall yielding properties or both.