Water level dynamics in wetlands and nesting success of Black Terns in Maine

USGS Publications Warehouse

Gilbert, A.T.; Servello, F.A.

2005-01-01

The Black Tern (Chlidonias niger) nests in freshwater wetlands that are prone to water level fluctuations, and nest losses to flooding are common. We examined temporal patterns in water levels at six sites with Black Tern colonies in Maine and determined probabilities of flood events and associated nest loss at Douglas Pond, the location of the largest breeding colony. Daily precipitation data from weather stations and water flow data from a flow gauge below Douglas Pond were obtained for 1960-1999. Information on nest losses from three floods at Douglas Pond in 1997-1999 were used to characterize small (6% nest loss), medium (56% nest loss) and large (94% nest loss) flood events, and we calculated probabilities of these three levels of flooding occurring at Douglas Pond using historic water levels data. Water levels generally decreased gradually during the nesting season at colony sites, except at Douglas Pond where water levels fluctuated substantially in response to rain events. Annual probabilities of small, medium, and large flood events were 68%, 35%, and 13% for nests initiated during 23 May-12 July, with similar probabilities for early (23 May-12 June) and late (13 June-12 July) periods. An index of potential nest loss indicated that medium floods at Douglas Pond had the greatest potential effect on nest success because they occurred relatively frequently and inundated large proportions of nests. Nest losses at other colonies were estimated to be approximately 30% of those at Douglas Pond. Nest losses to flooding appear to be common for the Black Tern in Maine and related to spring precipitation patterns, but ultimate effects on breeding productivity are uncertain.

ERP Correlates of Verbal and Numerical Probabilities in Risky Choices: A Two-Stage Probability Processing View

PubMed Central

Li, Shu; Du, Xue-Lei; Li, Qi; Xuan, Yan-Hua; Wang, Yun; Rao, Li-Lin

2016-01-01

Two kinds of probability expressions, verbal and numerical, have been used to characterize the uncertainty that people face. However, the question of whether verbal and numerical probabilities are cognitively processed in a similar manner remains unresolved. From a levels-of-processing perspective, verbal and numerical probabilities may be processed differently during early sensory processing but similarly in later semantic-associated operations. This event-related potential (ERP) study investigated the neural processing of verbal and numerical probabilities in risky choices. The results showed that verbal probability and numerical probability elicited different N1 amplitudes but that verbal and numerical probabilities elicited similar N2 and P3 waveforms in response to different levels of probability (high to low). These results were consistent with a levels-of-processing framework and suggest some internal consistency between the cognitive processing of verbal and numerical probabilities in risky choices. Our findings shed light on possible mechanism underlying probability expression and may provide the neural evidence to support the translation of verbal to numerical probabilities (or vice versa). PMID:26834612

Spatial Prediction of Coxiella burnetii Outbreak Exposure via Notified Case Counts in a Dose-Response Model.

PubMed

Brooke, Russell J; Kretzschmar, Mirjam E E; Hackert, Volker; Hoebe, Christian J P A; Teunis, Peter F M; Waller, Lance A

2017-01-01

We develop a novel approach to study an outbreak of Q fever in 2009 in the Netherlands by combining a human dose-response model with geostatistics prediction to relate probability of infection and associated probability of illness to an effective dose of Coxiella burnetii. The spatial distribution of the 220 notified cases in the at-risk population are translated into a smooth spatial field of dose. Based on these symptomatic cases, the dose-response model predicts a median of 611 asymptomatic infections (95% range: 410, 1,084) for the 220 reported symptomatic cases in the at-risk population; 2.78 (95% range: 1.86, 4.93) asymptomatic infections for each reported case. The low attack rates observed during the outbreak range from (Equation is included in full-text article.)to (Equation is included in full-text article.). The estimated peak levels of exposure extend to the north-east from the point source with an increasing proportion of asymptomatic infections further from the source. Our work combines established methodology from model-based geostatistics and dose-response modeling allowing for a novel approach to study outbreaks. Unobserved infections and the spatially varying effective dose can be predicted using the flexible framework without assuming any underlying spatial structure of the outbreak process. Such predictions are important for targeting interventions during an outbreak, estimating future disease burden, and determining acceptable risk levels.

Multi-level biological responses in Ucides cordatus (Linnaeus, 1763) (Brachyura, Ucididae) as indicators of conservation status in mangrove areas from the western atlantic.

PubMed

Duarte, Luis Felipe de Almeida; Souza, Caroline Araújo de; Nobre, Caio Rodrigues; Pereira, Camilo Dias Seabra; Pinheiro, Marcelo Antonio Amaro

2016-11-01

There is a global lack of knowledge on tropical ecotoxicology, particularly in terms of mangrove areas. These areas often serve as nurseries or homes for several animal species, including Ucides cordatus (the uçá crab). This species is widely distributed, is part of the diet of human coastal communities, and is considered to be a sentinel species due to its sensitivity to toxic xenobiotics in natural environments. Sublethal damages to benthic populations reveal pre-pathological conditions, but discussions of the implications are scarce in the literature. In Brazil, the state of São Paulo offers an interesting scenario for ecotoxicology and population studies: it is easy to distinguish between mangroves that are well preserved and those which are significantly impacted by human activity. The objectives of this study were to provide the normal baseline values for the frequency of Micronucleated cells (MN‰) and for neutral red retention time (NRRT) in U. cordatus at pristine locations, as well to indicate the conservation status of different mangrove areas using a multi-level biological response approach in which these biomarkers and population indicators (condition factor and crab density) are applied in relation to environmental quality indicators (determined via information in the literature and solid waste volume). A mangrove area with no effects of impact (areas of reference or pristine areas) presented a mean value of MN‰<3 and NRRT>120min, values which were assumed as baseline values representing genetic and physiological normality. A significant correlation was found between NRRT and MN, with both showing similar and effective results for distinguishing between different mangrove areas according to conservation status. Furthermore, crab density was lower in more impacted mangrove areas, a finding which also reflects the effects of sublethal damage; this finding was not determined by condition factor measurements. Multi-level biological responses were able to reflect the conservation status of the mangrove areas studied using information on guideline values of MN‰, NRRT, and density of the uçá crab in order to categorize three levels of human impacts in mangrove areas: PNI (probable null impact); PLI (probable low impact); and PHI (probable high impact). Results confirm the success of U. cordatus species' multi-level biological responses in diagnosing threats to mangrove areas. Therefore, this species represents an effective tool in studies on mangrove conservation statuses in the Western Atlantic. Copyright © 2016 Elsevier Inc. All rights reserved.

Eliciting Survival Expectations of the Elderly in Low-Income Countries: Evidence From India.

PubMed

Delavande, Adeline; Lee, Jinkook; Menon, Seetha

2017-04-01

We examine several methodological considerations when eliciting probabilistic expectations in a developing country context using the Longitudinal Ageing Study in India (LASI). We conclude that although, on average, individuals are able to understand the concept of probability, responses are sensitive to framing effects and to own versus hypothetical-person effects. We find that overall, people are pessimistic about their survival probabilities compared with state-specific life tables and that socioeconomic status does influence beliefs about own survival expectations as found in previous literature in other countries. Higher levels of education and income have a positive association with survival expectations, and these associations persist even when conditioning on self-reported health. The results remain robust to several alternative specifications. We then compare the survival measures with objective measures of health. We find that activities of daily life, height, and low hemoglobin levels covary with subjective expectations in expected directions.

Comparative Analytical Study of Evoked and Event Related Potentials as Correlates of Cognitive Processes

DTIC Science & Technology

1990-07-16

lower brain levels, probably precognitive , suggesting the need to distinguish the components in humans that depend on cognition from those that do...definition of the stimulus regime and that much of this response occurs at lower brain levels, probably precognitive , suggesting the need to distinguish the

Bayesian enhancement two-stage design for single-arm phase II clinical trials with binary and time-to-event endpoints.

PubMed

Shi, Haolun; Yin, Guosheng

2018-02-21

Simon's two-stage design is one of the most commonly used methods in phase II clinical trials with binary endpoints. The design tests the null hypothesis that the response rate is less than an uninteresting level, versus the alternative hypothesis that the response rate is greater than a desirable target level. From a Bayesian perspective, we compute the posterior probabilities of the null and alternative hypotheses given that a promising result is declared in Simon's design. Our study reveals that because the frequentist hypothesis testing framework places its focus on the null hypothesis, a potentially efficacious treatment identified by rejecting the null under Simon's design could have only less than 10% posterior probability of attaining the desirable target level. Due to the indifference region between the null and alternative, rejecting the null does not necessarily mean that the drug achieves the desirable response level. To clarify such ambiguity, we propose a Bayesian enhancement two-stage (BET) design, which guarantees a high posterior probability of the response rate reaching the target level, while allowing for early termination and sample size saving in case that the drug's response rate is smaller than the clinically uninteresting level. Moreover, the BET design can be naturally adapted to accommodate survival endpoints. We conduct extensive simulation studies to examine the empirical performance of our design and present two trial examples as applications. © 2018, The International Biometric Society.

Intracranial Self-Stimulation to Evaluate Abuse Potential of Drugs

PubMed Central

Miller, Laurence L.

2014-01-01

Intracranial self-stimulation (ICSS) is a behavioral procedure in which operant responding is maintained by pulses of electrical brain stimulation. In research to study abuse-related drug effects, ICSS relies on electrode placements that target the medial forebrain bundle at the level of the lateral hypothalamus, and experimental sessions manipulate frequency or amplitude of stimulation to engender a wide range of baseline response rates or response probabilities. Under these conditions, drug-induced increases in low rates/probabilities of responding maintained by low frequencies/amplitudes of stimulation are interpreted as an abuse-related effect. Conversely, drug-induced decreases in high rates/probabilities of responding maintained by high frequencies/amplitudes of stimulation can be interpreted as an abuse-limiting effect. Overall abuse potential can be inferred from the relative expression of abuse-related and abuse-limiting effects. The sensitivity and selectivity of ICSS to detect abuse potential of many classes of abused drugs is similar to the sensitivity and selectivity of drug self-administration procedures. Moreover, similar to progressive-ratio drug self-administration procedures, ICSS data can be used to rank the relative abuse potential of different drugs. Strengths of ICSS in comparison with drug self-administration include 1) potential for simultaneous evaluation of both abuse-related and abuse-limiting effects, 2) flexibility for use with various routes of drug administration or drug vehicles, 3) utility for studies in drug-naive subjects as well as in subjects with controlled levels of prior drug exposure, and 4) utility for studies of drug time course. Taken together, these considerations suggest that ICSS can make significant contributions to the practice of abuse potential testing. PMID:24973197

Data Mining of Historical Human Data to Assess the Risk of Injury due to Dynamic Loads

NASA Technical Reports Server (NTRS)

Wells, Jesica; Somers, Jeffrey T.; Newby, N.; Gernhardt, Michael

2014-01-01

The NASA Occupant Protection Group is charged with ensuring crewmembers are protected during all dynamic phases of spaceflight. Previous work with outside experts has led to the development of a definition of acceptable risk (DAR) for space capsule vehicles. The DAR defines allowable probability rates for various categories of injuries. An important question is how to validate these probabilities for a given vehicle. One approach is to impact test human volunteers under projected nominal landing loads. The main drawback is the large number of subject tests required to attain a reasonable level of confidence that the injury probability rates would meet those outlined in the DAR. An alternative is to mine existing databases containing human responses to impact. Testing an anthropomorphic test device (ATD) at the same human-exposure levels could yield a range of ATD responses that would meet DAR. As one aspect of future vehicle validation, the ATD could be tested in the vehicle's seat and suit configuration at nominal landing loads and compared with the ATD responses supported by the human data set. This approach could reduce the number of human-volunteer tests NASA would need to conduct to validate that a vehicle meets occupant protection standards. METHODS: The U.S. Air Force has recorded hundreds of human responses to frontal, lateral, and spinal impacts at many acceleration levels and pulse durations. All of this data are stored on the Collaborative Biomechanics Data Network (CBDN), which is maintained by the Wright Patterson Air Force Base (WPAFB). The test device for human occupant restraint (THOR) ATD was impact tested on WPAFB's horizontal impulse accelerator (HIA) matching human-volunteer exposures on the HIA to 5 frontal and 3 spinal loading conditions. No human injuries occurred as a result of these impact conditions. Peak THOR response variables for neck axial tension and compression, and thoracic-spine axial compression were collected. Maximal chest deflection was determined from motion capture video of the impact test. HIC- 15 and BRIC were calculated from head acceleration responses. Given the number of human subjects for each test condition a confidence interval of injury probability will be obtained. RESULTS: Results will be discussed in terms of injury-risk probability estimates based on the human data set evaluated. Also, gaps in the data set will be identified. These gaps could be one of two types. One is areas where additional THOR testing would increase the comparable human data set, thereby improving confidence in the injury probability rate. The other is where additional human testing would assist in obtaining information on other acceleration levels or directions. DISCUSSION: The historical human data showed validity of the THOR ATD for supplemental testing. The historical human data are limited in scope, however. Further data are needed to characterize the effects of sex, age, anthropometry, and deconditioning due to spaceflight on risk of injury

Concurrent progressive ratio schedules: Effects of reinforcer probability on breakpoint and response allocation.

PubMed

Jarmolowicz, David P; Sofis, Michael J; Darden, Alexandria C

2016-07-01

Although progressive ratio (PR) schedules have been used to explore effects of a range of reinforcer parameters (e.g., magnitude, delay), effects of reinforcer probability remain underexplored. The present project used independently progressing concurrent PR PR schedules to examine effects of reinforcer probability on PR breakpoint (highest completed ratio prior to a session terminating 300s pause) and response allocation. The probability of reinforcement on one lever remained at 100% across all conditions while the probability of reinforcement on the other lever was systematically manipulated (i.e., 100%, 50%, 25%, 12.5%, and a replication of 25%). Breakpoints systematically decreased with decreasing reinforcer probabilities while breakpoints on the control lever remained unchanged. Patterns of switching between the two levers were well described by a choice-by-choice unit price model that accounted for the hyperbolic discounting of the value of probabilistic reinforcers. Copyright © 2016 Elsevier B.V. All rights reserved.

Stimulus Probability Effects in Absolute Identification

ERIC Educational Resources Information Center

Kent, Christopher; Lamberts, Koen

2016-01-01

This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

Carry-over effects of the social environment on future divorce probability in a wild bird population

PubMed Central

Culina, Antica; Hinde, Camilla A.; Sheldon, Ben C.

2015-01-01

Initial mate choice and re-mating strategies (infidelity and divorce) influence individual fitness. Both of these should be influenced by the social environment, which determines the number and availability of potential partners. While most studies looking at this relationship take a population-level approach, individual-level responses to variation in the social environment remain largely unstudied. Here, we explore carry-over effects on future mating decisions of the social environment in which the initial mating decision occurred. Using detailed data on the winter social networks of great tits, we tested whether the probability of subsequent divorce, a year later, could be predicted by measures of the social environment at the time of pairing. We found that males that had a lower proportion of female associates, and whose partner ranked lower among these, as well as inexperienced breeders, were more likely to divorce after breeding. We found no evidence that a female's social environment influenced the probability of divorce. Our findings highlight the importance of the social environment that individuals experience during initial pair formation on later pairing outcomes, and demonstrate that such effects can be delayed. Exploring these extended effects of the social environment can yield valuable insights into processes and selective pressures acting upon the mating strategies that individuals adopt. PMID:26468239

High thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas).

PubMed

Antunes, R; Kvadsheim, P H; Lam, F P A; Tyack, P L; Thomas, L; Wensveen, P J; Miller, P J O

2014-06-15

The potential effects of exposing marine mammals to military sonar is a current concern. Dose-response relationships are useful for predicting potential environmental impacts of specific operations. To reveal behavioral response thresholds of exposure to sonar, we conducted 18 exposure/control approaches to 6 long-finned pilot whales. Source level and proximity of sonar transmitting one of two frequency bands (1-2 kHz and 6-7 kHz) were increased during exposure sessions. The 2-dimensional movement tracks were analyzed using a changepoint method to identify the avoidance response thresholds which were used to estimate dose-response relationships. No support for an effect of sonar frequency or previous exposures on the probability of response was found. Estimated response thresholds at which 50% of population show avoidance (SPLmax=170 dB re 1 μPa, SELcum=173 dB re 1 μPa(2) s) were higher than previously found for other cetaceans. The US Navy currently uses a generic dose-response relationship to predict the responses of cetaceans to naval active sonar, which has been found to underestimate behavioural impacts on killer whales and beaked whales. The navy curve appears to match more closely our results with long-finned pilot whales, though it might underestimate the probability of avoidance for pilot-whales at long distances from sonar sources. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tracking the Sensory Environment: An ERP Study of Probability and Context Updating in ASD

PubMed Central

Westerfield, Marissa A.; Zinni, Marla; Vo, Khang; Townsend, Jeanne

2014-01-01

We recorded visual event-related brain potentials (ERPs) from 32 adult male participants (16 high-functioning participants diagnosed with Autism Spectrum Disorder (ASD) and 16 control participants, ranging in age from 18–53 yrs) during a three-stimulus oddball paradigm. Target and non-target stimulus probability was varied across three probability conditions, whereas the probability of a third non-target stimulus was held constant in all conditions. P3 amplitude to target stimuli was more sensitive to probability in ASD than in TD participants, whereas P3 amplitude to non-target stimuli was less responsive to probability in ASD participants. This suggests that neural responses to changes in event probability are attention-dependant in high-functioning ASD. The implications of these findings for higher-level behaviors such as prediction and planning are discussed. PMID:24488156

An immune reaction may be necessary for cancer development.

PubMed

Prehn, Richmond T

2006-02-03

The hypothesis of immunosurveillance suggests that new neoplasms arise very frequently, but most are destroyed almost at their inception by an immune response. Its correctness has been debated for many years. In its support, it has been shown that the incidences of many tumor types, though apparently not all, tend to be increased in immunodeficient animals or humans, but this observation does not end the debate. There is an alternative to the surveillance hypothesis; numerous studies have shown that the effect of an immune reaction on a tumor is biphasic. For each tumor, there is some quantitatively low level of immune reaction that, relative to no reaction, is facilitating, perhaps even necessary for the tumor's growth in vivo. The optimum level of this facilitating reaction may often be less than the level of immunity that the tumor might engender in a normal subject. The failure of a tumor to grow as well in the normal as it does in the immunosuppressed host is probably not caused by a lack of tumor-cell killing in the suppressed host. Instead, the higher level of immune response in a normal animal, even if it does not rise to tumor-inhibitory levels, probably gives less positive support to tumor growth. This seems more than a semantic distinction.

An immune reaction may be necessary for cancer development

PubMed Central

Prehn, Richmond T

2006-01-01

Background The hypothesis of immunosurveillance suggests that new neoplasms arise very frequently, but most are destroyed almost at their inception by an immune response. Its correctness has been debated for many years. In its support, it has been shown that the incidences of many tumor types, though apparently not all, tend to be increased in immunodeficient animals or humans, but this observation does not end the debate. Alternative model There is an alternative to the surveillance hypothesis; numerous studies have shown that the effect of an immune reaction on a tumor is biphasic. For each tumor, there is some quantitatively low level of immune reaction that, relative to no reaction, is facilitating, perhaps even necessary for the tumor's growth in vivo. The optimum level of this facilitating reaction may often be less than the level of immunity that the tumor might engender in a normal subject. Conclusion The failure of a tumor to grow as well in the normal as it does in the immunosuppressed host is probably not caused by a lack of tumor-cell killing in the suppressed host. Instead, the higher level of immune response in a normal animal, even if it does not rise to tumor-inhibitory levels, probably gives less positive support to tumor growth. This seems more than a semantic distinction. PMID:16457723

Safe days in space with acceptable uncertainty from space radiation exposure.

PubMed

Cucinotta, Francis A; Alp, Murat; Rowedder, Blake; Kim, Myung-Hee Y

2015-04-01

The prediction of the risks of cancer and other late effects from space radiation exposure carries large uncertainties mostly due to the lack of information on the risks from high charge and energy (HZE) particles and other high linear energy transfer (LET) radiation. In our recent work new methods were used to consider NASA's requirement to protect against the acceptable risk of no more than 3% probability of cancer fatality estimated at the 95% confidence level. Because it is not possible that a zero-level of uncertainty could be achieved, we suggest that an acceptable uncertainty level should be defined in relationship to a probability distribution function (PDF) that only suffers from modest skewness with higher uncertainty allowed for a normal PDF. In this paper, we evaluate PDFs and the number or "safe days" in space, which are defined as the mission length where risk limits are not exceeded, for several mission scenarios at different acceptable levels of uncertainty. In addition, we briefly discuss several important issues in risk assessment including non-cancer effects, the distinct tumor spectra and lethality found in animal experiments for HZE particles compared to background or low LET radiation associated tumors, and the possibility of non-targeted effects (NTE) modifying low dose responses and increasing relative biological effectiveness (RBE) factors for tumor induction. Each of these issues skew uncertainty distributions to higher fatality probabilities with the potential to increase central values of risk estimates in the future. Therefore they will require significant research efforts to support space exploration within acceptable levels of risk and uncertainty. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Practice guideline update summary: Botulinum neurotoxin for the treatment of blepharospasm, cervical dystonia, adult spasticity, and headache

PubMed Central

Simpson, David M.; Hallett, Mark; Ashman, Eric J.; Comella, Cynthia L.; Green, Mark W.; Gronseth, Gary S.; Armstrong, Melissa J.; Gloss, David; Potrebic, Sonja; Jankovic, Joseph; Karp, Barbara P.; Naumann, Markus; So, Yuen T.; Yablon, Stuart A.

2016-01-01

Objective: To update the 2008 American Academy of Neurology (AAN) guidelines regarding botulinum neurotoxin for blepharospasm, cervical dystonia (CD), headache, and adult spasticity. Methods: We searched the literature for relevant articles and classified them using 2004 AAN criteria. Results and recommendations: Blepharospasm: OnabotulinumtoxinA (onaBoNT-A) and incobotulinumtoxinA (incoBoNT-A) are probably effective and should be considered (Level B). AbobotulinumtoxinA (aboBoNT-A) is possibly effective and may be considered (Level C). CD: AboBoNT-A and rimabotulinumtoxinB (rimaBoNT-B) are established as effective and should be offered (Level A), and onaBoNT-A and incoBoNT-A are probably effective and should be considered (Level B). Adult spasticity: AboBoNT-A, incoBoNT-A, and onaBoNT-A are established as effective and should be offered (Level A), and rimaBoNT-B is probably effective and should be considered (Level B), for upper limb spasticity. AboBoNT-A and onaBoNT-A are established as effective and should be offered (Level A) for lower-limb spasticity. Headache: OnaBoNT-A is established as effective and should be offered to increase headache-free days (Level A) and is probably effective and should be considered to improve health-related quality of life (Level B) in chronic migraine. OnaBoNT-A is established as ineffective and should not be offered for episodic migraine (Level A) and is probably ineffective for chronic tension-type headaches (Level B). PMID:27164716

Low doses of ionizing radiation to mammalian cells may rather control than cause DNA damage

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

Feinendegen, L.E.; Bond, V.P.; Sondhaus, C.A.

This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced metabolic changes that induce mechanisms of DNA damage mitigation, which do not operate at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in themore » low-dose region. This suggests that the LNT hypothesis should be reexamined. This paper aims at demonstrating tissue effects as an expression of cellular responses, both damaging and defensive, in relation to the energy deposited in cell mass, by use of microdosimetric concepts.« less

Maternal programming of defensive responses through sustained effects on gene expression.

PubMed

Zhang, Tie-Yuan; Bagot, Rose; Parent, Carine; Nesbitt, Cathy; Bredy, Timothy W; Caldji, Christian; Fish, Eric; Anisman, Hymie; Szyf, Moshe; Meaney, Michael J

2006-07-01

There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype. In this paper we review data from the rat that suggest comparable forms of maternal effects on defensive responses stress, which are mediated by the effects of variations in maternal behavior on gene expression. Under conditions of environmental adversity maternal effects enhance the capacity for defensive responses in the offspring. In mammals, these effects appear to 'program' emotional, cognitive and endocrine systems towards increased sensitivity to adversity. In environments with an increased level of adversity, such effects can be considered adaptive, enhancing the probability of offspring survival to sexual maturity; the cost is that of an increased risk for multiple forms of pathology in later life.

Ordinal probability effect measures for group comparisons in multinomial cumulative link models.

PubMed

Agresti, Alan; Kateri, Maria

2017-03-01

We consider simple ordinal model-based probability effect measures for comparing distributions of two groups, adjusted for explanatory variables. An "ordinal superiority" measure summarizes the probability that an observation from one distribution falls above an independent observation from the other distribution, adjusted for explanatory variables in a model. The measure applies directly to normal linear models and to a normal latent variable model for ordinal response variables. It equals Φ(β/2) for the corresponding ordinal model that applies a probit link function to cumulative multinomial probabilities, for standard normal cdf Φ and effect β that is the coefficient of the group indicator variable. For the more general latent variable model for ordinal responses that corresponds to a linear model with other possible error distributions and corresponding link functions for cumulative multinomial probabilities, the ordinal superiority measure equals exp(β)/[1+exp(β)] with the log-log link and equals approximately exp(β/2)/[1+exp(β/2)] with the logit link, where β is the group effect. Another ordinal superiority measure generalizes the difference of proportions from binary to ordinal responses. We also present related measures directly for ordinal models for the observed response that need not assume corresponding latent response models. We present confidence intervals for the measures and illustrate with an example. © 2016, The International Biometric Society.

Spectral-temporal EEG dynamics of speech discrimination processing in infants during sleep.

PubMed

Gilley, Phillip M; Uhler, Kristin; Watson, Kaylee; Yoshinaga-Itano, Christine

2017-03-22

Oddball paradigms are frequently used to study auditory discrimination by comparing event-related potential (ERP) responses from a standard, high probability sound and to a deviant, low probability sound. Previous research has established that such paradigms, such as the mismatch response or mismatch negativity, are useful for examining auditory processes in young children and infants across various sleep and attention states. The extent to which oddball ERP responses may reflect subtle discrimination effects, such as speech discrimination, is largely unknown, especially in infants that have not yet acquired speech and language. Mismatch responses for three contrasts (non-speech, vowel, and consonant) were computed as a spectral-temporal probability function in 24 infants, and analyzed at the group level by a modified multidimensional scaling. Immediately following an onset gamma response (30-50 Hz), the emergence of a beta oscillation (12-30 Hz) was temporally coupled with a lower frequency theta oscillation (2-8 Hz). The spectral-temporal probability of this coupling effect relative to a subsequent theta modulation corresponds with discrimination difficulty for non-speech, vowel, and consonant contrast features. The theta modulation effect suggests that unexpected sounds are encoded as a probabilistic measure of surprise. These results support the notion that auditory discrimination is driven by the development of brain networks for predictive processing, and can be measured in infants during sleep. The results presented here have implications for the interpretation of discrimination as a probabilistic process, and may provide a basis for the development of single-subject and single-trial classification in a clinically useful context. An infant's brain is processing information about the environment and performing computations, even during sleep. These computations reflect subtle differences in acoustic feature processing that are necessary for language-learning. Results from this study suggest that brain responses to deviant sounds in an oddball paradigm follow a cascade of oscillatory modulations. This cascade begins with a gamma response that later emerges as a beta synchronization, which is temporally coupled with a theta modulation, and followed by a second, subsequent theta modulation. The difference in frequency and timing of the theta modulations appears to reflect a measure of surprise. These insights into the neurophysiological mechanisms of auditory discrimination provide a basis for exploring the clinically utility of the MMR TF and other auditory oddball responses.

The influence of the diffusion of responsibility effect on outcome evaluations: electrophysiological evidence from an ERP study.

PubMed

Li, Peng; Jia, Shiwei; Feng, Tingyong; Liu, Qiang; Suo, Tao; Li, Hong

2010-10-01

Previous studies have revealed that personal responsibility has an influence on outcome evaluation, although the way this influence works is still unclear. This study imitated the phenomenon of responsibility diffusion in a laboratory to examine the influence of the effect of responsibility diffusion on the processing of outcome evaluation using the event-related potential (ERP) technique. Participants of the study were required to perform the gambling task individually in the high-responsibility condition and with others in the low-responsibility scenario. Self-rating results showed that the participants felt more responsible for monetary loss and believed that they had more contributions to the monetary gains in the high-responsibility condition than in the low-responsibility situation. Both the feedback-related negativity (FRN) and the P300 were sensitive to the responsibility level, as evidenced by the enhanced amplitudes in the high-responsibility condition for both components. Further correlation analysis showed a negative correlation between FRN amplitudes and subjective rating scores (i.e., the higher the responsibility level, the larger the FRN amplitude). The results probably indicate that the FRN and P300 reflect personal responsibility processing under the social context of diffusion of responsibility. Copyright 2010 Elsevier Inc. All rights reserved.

Comparison of Annoyance from Railway Noise and Railway Vibration.

PubMed

Ögren, Mikael; Gidlöf-Gunnarsson, Anita; Smith, Michael; Gustavsson, Sara; Persson Waye, Kerstin

2017-07-19

The aim of this study is to compare vibration exposure to noise exposure from railway traffic in terms of equal annoyance, i.e., to determine when a certain noise level is equally annoying as a corresponding vibration velocity. Based on questionnaire data from the Train Vibration and Noise Effects (TVANE) research project from residential areas exposed to railway noise and vibration, the dose response relationship for annoyance was estimated. By comparing the relationships between exposure and annoyance for areas both with and without significant vibration exposure, the noise levels and vibration velocities that had an equal probability of causing annoyance was determined using logistic regression. The comparison gives a continuous mapping between vibration velocity in the ground and a corresponding noise level at the facade that are equally annoying. For equivalent noise level at the facade compared to maximum weighted vibration velocity in the ground the probability of annoyance is approximately 20% for 59 dB or 0.48 mm/s, and about 40% for 63 dB or 0.98 mm/s.

Regional cutaneous microvascular flow responses during gravitational and LBNP stresses

NASA Technical Reports Server (NTRS)

Breit, Gregory A.; Watenpaugh, Donald E.; Ballard, Richard E.; Murthy, Gita; Hargens, Alan R.

1993-01-01

Due to the regional variability of local hydrostatic pressures, microvascular flow responses to gravitational stress probably vary along the length of the body. Although these differences in local autoregulation have been observed previously during whole-body tilting, they have not been investigated during application of artificial gravitational stresses, such as lower body negative pressure or high gravity centrifugation. Although these stresses can create equivalent G-levels at the feet, they result in distinct distributions of vascular transmural pressure along the length of the body, and should consequently elicit different magnitudes and distributions of microvascular response. In the present study, the effects of whole-body tilting and lower body negative pressure on the level and distribution of microvascular flows within skin along the length of the body were compared.

High But Not Low Probability of Gain Elicits a Positive Feeling Leading to the Framing Effect.

PubMed

Gosling, Corentin J; Moutier, Sylvain

2017-01-01

Human risky decision-making is known to be highly susceptible to profit-motivated responses elicited by the way in which options are framed. In fact, studies investigating the framing effect have shown that the choice between sure and risky options depends on how these options are presented. Interestingly, the probability of gain of the risky option has been highlighted as one of the main factors causing variations in susceptibility to the framing effect. However, while it has been shown that high probabilities of gain of the risky option systematically lead to framing bias, questions remain about the influence of low probabilities of gain. Therefore, the first aim of this paper was to clarify the respective roles of high and low probabilities of gain in the framing effect. Due to the difference between studies using a within- or between-subjects design, we conducted a first study investigating the respective roles of these designs. For both designs, we showed that trials with a high probability of gain led to the framing effect whereas those with a low probability did not. Second, as emotions are known to play a key role in the framing effect, we sought to determine whether they are responsible for such a debiasing effect of the low probability of gain. Our second study thus investigated the relationship between emotion and the framing effect depending on high and low probabilities. Our results revealed that positive emotion was related to risk-seeking in the loss frame, but only for trials with a high probability of gain. Taken together, these results support the interpretation that low probabilities of gain suppress the framing effect because they prevent the positive emotion of gain anticipation.

High But Not Low Probability of Gain Elicits a Positive Feeling Leading to the Framing Effect

PubMed Central

Gosling, Corentin J.; Moutier, Sylvain

2017-01-01

Human risky decision-making is known to be highly susceptible to profit-motivated responses elicited by the way in which options are framed. In fact, studies investigating the framing effect have shown that the choice between sure and risky options depends on how these options are presented. Interestingly, the probability of gain of the risky option has been highlighted as one of the main factors causing variations in susceptibility to the framing effect. However, while it has been shown that high probabilities of gain of the risky option systematically lead to framing bias, questions remain about the influence of low probabilities of gain. Therefore, the first aim of this paper was to clarify the respective roles of high and low probabilities of gain in the framing effect. Due to the difference between studies using a within- or between-subjects design, we conducted a first study investigating the respective roles of these designs. For both designs, we showed that trials with a high probability of gain led to the framing effect whereas those with a low probability did not. Second, as emotions are known to play a key role in the framing effect, we sought to determine whether they are responsible for such a debiasing effect of the low probability of gain. Our second study thus investigated the relationship between emotion and the framing effect depending on high and low probabilities. Our results revealed that positive emotion was related to risk-seeking in the loss frame, but only for trials with a high probability of gain. Taken together, these results support the interpretation that low probabilities of gain suppress the framing effect because they prevent the positive emotion of gain anticipation. PMID:28232808

CO2 and nutrient-driven changes across multiple levels of organization in Zostera noltii ecosystems

NASA Astrophysics Data System (ADS)

Martínez-Crego, B.; Olivé, I.; Santos, R.

2014-12-01

Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low- and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and context-dependent, being mediated by epiphyte overgrowth rather than by direct effects on plant biochemistry. Overall, we found that the responses of seagrass meadows to individual and interactive effects of CO2 and nutrient enrichment varied depending on interactions among species and connections between organization levels.

Population pharmacodynamic modelling of midazolam induced sedation in terminally ill adult patients

PubMed Central

de Winter, Brenda C. M.; Masman, Anniek D.; van Dijk, Monique; Baar, Frans P. M.; Tibboel, Dick; Koch, Birgit C. P.; van Gelder, Teun; Mathot, Ron A. A.

2017-01-01

Aims Midazolam is the drug of choice for palliative sedation and is titrated to achieve the desired level of sedation. A previous pharmacokinetic (PK) study showed that variability between patients could be partly explained by renal function and inflammatory status. The goal of this study was to combine this PK information with pharmacodynamic (PD) data, to evaluate the variability in response to midazolam and to find clinically relevant covariates that may predict PD response. Method A population PD analysis using nonlinear mixed effect models was performed with data from 43 terminally ill patients. PK profiles were predicted by a previously described PK model and depth of sedation was measured using the Ramsay sedation score. Patient and disease characteristics were evaluated as possible covariates. The final model was evaluated using a visual predictive check. Results The effect of midazolam on the sedation level was best described by a differential odds model including a baseline probability, Emax model and interindividual variability on the overall effect. The EC50 value was 68.7 μg l–1 for a Ramsay score of 3–5 and 117.1 μg l–1 for a Ramsay score of 6. Comedication with haloperidol was the only significant covariate. The visual predictive check of the final model showed good model predictability. Conclusion We were able to describe the clinical response to midazolam accurately. As expected, there was large variability in response to midazolam. The use of haloperidol was associated with a lower probability of sedation. This may be a result of confounding by indication, as haloperidol was used to treat delirium, and deliria has been linked to a more difficult sedation procedure. PMID:28960387

Stochastic model of transcription factor-regulated gene expression

NASA Astrophysics Data System (ADS)

Karmakar, Rajesh; Bose, Indrani

2006-09-01

We consider a stochastic model of transcription factor (TF)-regulated gene expression. The model describes two genes, gene A and gene B, which synthesize the TFs and the target gene proteins, respectively. We show through analytic calculations that the TF fluctuations have a significant effect on the distribution of the target gene protein levels when the mean TF level falls in the highest sensitive region of the dose-response curve. We further study the effect of reducing the copy number of gene A from two to one. The enhanced TF fluctuations yield results different from those in the deterministic case. The probability that the target gene protein level exceeds a threshold value is calculated with the knowledge of the probability density functions associated with the TF and target gene protein levels. Numerical simulation results for a more detailed stochastic model are shown to be in agreement with those obtained through analytic calculations. The relevance of these results in the context of the genetic disorder haploinsufficiency is pointed out. Some experimental observations on the haploinsufficiency of the tumour suppressor gene, Nkx 3.1, are explained with the help of the stochastic model of TF-regulated gene expression.

Study on safety level of RC beam bridges under earthquake

NASA Astrophysics Data System (ADS)

Zhao, Jun; Lin, Junqi; Liu, Jinlong; Li, Jia

2017-08-01

This study considers uncertainties in material strengths and the modeling which have important effects on structural resistance force based on reliability theory. After analyzing the destruction mechanism of a RC bridge, structural functions and the reliability were given, then the safety level of the piers of a reinforced concrete continuous girder bridge with stochastic structural parameters against earthquake was analyzed. Using response surface method to calculate the failure probabilities of bridge piers under high-level earthquake, their seismic reliability for different damage states within the design reference period were calculated applying two-stage design, which describes seismic safety level of the built bridges to some extent.

Condom Use as a Function of Number of Coital Events in New Relationships.

PubMed

He, Fei; Hensel, Devon J; Harezlak, Jaroslaw; Fortenberry, J Dennis

2016-02-01

To assess condom use as a function of number of coital events in newly formed sexual relationships. Participants who reported at least one new partner during the 12-week study interval (n = 115; ages 18-29 years; 48% women; 90% African American) completed weekly sexually transmitted infections testing and 3 times daily electronic diary collection assessing individual and partner-specific affect, daily activities, sexual behavior, and condom use. We analyzed event-level condom use percentage and participant-level behavior response effects. generalized additive mixed models were used to estimate condom use probability accounting for within-partner and within-participant correlations via random effects. The average condom use probability at the first coital event in new relationships was 55% for men and 36% for women. Analyses showed that smooth shapes of estimated condom use probabilities were similar for both sexes and were fitted using generalized additive mixed models. Relatively higher condom use percentage was followed by a sharp decline during the first 9 coital events decreasing to 16% for men and 8% for women. More rapid decline in condom use among women was highly associated with higher levels of relationship and sexual satisfaction. The likelihood of condom use declines sharply for both men and women after the early accrual experience with a partner. Relationship and sexual satisfaction also influence declines in condom use, especially among women.

Condom use as a function of number of coital events in new relationships

PubMed Central

He, Fei; Hensel, Devon J.; Harezlak, Jaroslaw; Fortenberry, J. Dennis

2015-01-01

Study Objective Assess condom use as a function of number of coital events in newly formed sexual relationships. Methods Participants who reported at least one new partner during the 12-week study interval (N=115; ages 18–29 years; 48% women; 90% African American) completed weekly sexually transmitted infections testing and three-times daily electronic diary collection assessing individual and partner-specific affect, daily activities, sexual behavior and condom use. We analyzed event-level condom use percentage and subject-level behavior response effects. Generalized Additive Mixed Models (GAMMs) were used to estimate condom use probability accounting for within-partner and within-subject correlations via random effects. Results The average condom use probability at the first coital event in new relationships was 55% for men and 36% for women. Analyses showed that smooth shapes of estimated condom use probabilities were similar for both sexes and were fitted using GAMMs. Relatively higher condom use percentage was followed by a sharp decline during the first 9 coital events decreasing to 16% for men and 8% for women. More rapid decline in condom use among women was highly associated with higher levels of relationship and sexual satisfaction. Conclusions The likelihood of condom use declines sharply for both men and women after the early accrual experience with a partner. Relationship and sexual satisfaction also influence declines in condom use, especially among women. PMID:26766522

Targeting, Monitoring and Effect of Oral Iron Therapy on Haemoglobin Levels in Older Patients Discharged to Primary Care from Inpatient Rehabilitation: A Cohort Study Using Routinely Collected Data.

PubMed

Thomson, Zach; Hands, Katherine J; Witham, Miles D

2016-08-01

Oral iron is commonly prescribed to older patients with suspected or confirmed iron-deficiency anaemia; however, few studies have examined the effectiveness of oral iron therapy in the real world in this population. We therefore determined the prevalence of iron deficiency in older people prescribed oral iron, examined the response mounted to therapy and ascertained predictors of response to oral iron. We analysed a routinely collected, linked dataset from older patients who had undergone inpatient rehabilitation between 1999 and 2011. An initial analysis examined patients within this cohort who were prescribed iron after rehabilitation and derived three groups based upon their ferritin and transferrin indices: probably, possibly and not iron deficient. A second analysis compared pre- and post-treatment haemoglobin to determine the degree of response to iron therapy across each category of deficiency. Finally, patient demographics, linked biochemistry data and comorbid disease based on International Classification of Disease (ICD-10) codes from previous hospital admissions were used in regression modelling to evaluate factors affecting response to therapy. A total of 490 patients were prescribed oral iron within 90 days of rehabilitation discharge. Of these, 413 (84 %) had iron indices performed; 94 (23 %) were possibly deficient, 224 (54 %) were probably deficient, and 95 (23 %) were not deficient. Of the 490 patients, 360 had both pre- and post-treatment haemoglobin data and iron indices; probably deficient patients mounted a slightly greater response to oral iron (17 vs. 12 g/L for not deficient; p < 0.05). Only pre-treatment haemoglobin, mean cell volume and lower gastrointestinal pathology were significant predictors of a response to oral iron therapy. Notably, acid-suppressant use was not a predictor of response. We conclude that many older patients are exposed to oral iron without good evidence of either iron deficiency or a significant response to therapy.

Affective and cognitive factors influencing sensitivity to probabilistic information.

PubMed

Tyszka, Tadeusz; Sawicki, Przemyslaw

2011-11-01

In study 1 different groups of female students were randomly assigned to one of four probabilistic information formats. Five different levels of probability of a genetic disease in an unborn child were presented to participants (within-subject factor). After the presentation of the probability level, participants were requested to indicate the acceptable level of pain they would tolerate to avoid the disease (in their unborn child), their subjective evaluation of the disease risk, and their subjective evaluation of being worried by this risk. The results of study 1 confirmed the hypothesis that an experience-based probability format decreases the subjective sense of worry about the disease, thus, presumably, weakening the tendency to overrate the probability of rare events. Study 2 showed that for the emotionally laden stimuli, the experience-based probability format resulted in higher sensitivity to probability variations than other formats of probabilistic information. These advantages of the experience-based probability format are interpreted in terms of two systems of information processing: the rational deliberative versus the affective experiential and the principle of stimulus-response compatibility. © 2011 Society for Risk Analysis.

Prior probability modulates anticipatory activity in category-specific areas.

PubMed

Trapp, Sabrina; Lepsien, Jöran; Kotz, Sonja A; Bar, Moshe

2016-02-01

Bayesian models are currently a dominant framework for describing human information processing. However, it is not clear yet how major tenets of this framework can be translated to brain processes. In this study, we addressed the neural underpinning of prior probability and its effect on anticipatory activity in category-specific areas. Before fMRI scanning, participants were trained in two behavioral sessions to learn the prior probability and correct order of visual events within a sequence. The events of each sequence included two different presentations of a geometric shape and one picture of either a house or a face, which appeared with either a high or a low likelihood. Each sequence was preceded by a cue that gave participants probabilistic information about which items to expect next. This allowed examining cue-related anticipatory modulation of activity as a function of prior probability in category-specific areas (fusiform face area and parahippocampal place area). Our findings show that activity in the fusiform face area was higher when faces had a higher prior probability. The finding of a difference between levels of expectations is consistent with graded, probabilistically modulated activity, but the data do not rule out the alternative explanation of a categorical neural response. Importantly, these differences were only visible during anticipation, and vanished at the time of stimulus presentation, calling for a functional distinction when considering the effects of prior probability. Finally, there were no anticipatory effects for houses in the parahippocampal place area, suggesting sensitivity to stimulus material when looking at effects of prediction.

Are stress-induced cortisol changes during pregnancy associated with postpartum depressive symptoms?

PubMed

Nierop, Ada; Bratsikas, Aliki; Zimmermann, Roland; Ehlert, Ulrike

2006-01-01

The purpose of this study was to examine the association between psychobiological stress reactivity during healthy pregnancy and depressive symptoms in the early puerperium. A sample of healthy nulliparous pregnant women (N = 57) between the ages of 21 and 35 years underwent a standardized psychosocial stress test during pregnancy. Within an average of 13 days after delivery, postpartum depressive symptoms were assessed using the German version of the Edinburgh postnatal depression scale (EPDS). The sample was divided into a group with probable cases (EPDS score >9, N = 16) and a group with probable noncases (EPDS score < or =9, N = 41). The probable case group showed significantly higher cortisol responses to the stress test compared with the probable noncase group, whereas baseline levels did not differ. Additionally, women in the probable case group showed significantly higher state anxiety and lower mood state throughout the experiment. Furthermore, the probable case group showed higher stress susceptibility, higher trait anxiety, and higher levels in the Symptom Checklist. No differences were found for prior episodes of psychiatric disorders, obstetrical complications, birth weight, or mode of delivery. Our data provide evidence that healthy pregnant women developing postpartum depressive symptoms might already be identified during pregnancy by means of their higher cortisol reactivity and their higher psychological reactivity in response to psychosocial stress. Further investigations are required to explore whether higher psychobiological stress responses not only precede depressive symptoms within 2 weeks after birth, but might also predict postpartum major depression.

Surveillance guidelines for disease elimination: A case study of canine rabies

PubMed Central

Townsend, Sunny E.; Lembo, Tiziana; Cleaveland, Sarah; Meslin, François X.; Miranda, Mary Elizabeth; Putra, Anak Agung Gde; Haydon, Daniel T.; Hampson, Katie

2013-01-01

Surveillance is a critical component of disease control programmes but is often poorly resourced, particularly in developing countries lacking good infrastructure and especially for zoonoses which require combined veterinary and medical capacity and collaboration. Here we examine how successful control, and ultimately disease elimination, depends on effective surveillance. We estimated that detection probabilities of <0.1 are broadly typical of rabies surveillance in endemic countries and areas without a history of rabies. Using outbreak simulation techniques we investigated how the probability of detection affects outbreak spread, and outcomes of response strategies such as time to control an outbreak, probability of elimination, and the certainty of declaring freedom from disease. Assuming realistically poor surveillance (probability of detection <0.1), we show that proactive mass dog vaccination is much more effective at controlling rabies and no more costly than campaigns that vaccinate in response to case detection. Control through proactive vaccination followed by 2 years of continuous monitoring and vaccination should be sufficient to guarantee elimination from an isolated area not subject to repeat introductions. We recommend that rabies control programmes ought to be able to maintain surveillance levels that detect at least 5% (and ideally 10%) of all cases to improve their prospects of eliminating rabies, and this can be achieved through greater intersectoral collaboration. Our approach illustrates how surveillance is critical for the control and elimination of diseases such as canine rabies and can provide minimum surveillance requirements and technical guidance for elimination programmes under a broad-range of circumstances. PMID:23260376

Examining the Discriminative and Strengthening Effects of Reinforcers in Concurrent Schedules

PubMed Central

Boutros, Nathalie; Elliffe, Douglas; Davison, Michael

2011-01-01

Reinforcers may increase operant responding via a response-strengthening mechanism whereby the probability of the preceding response increases, or via some discriminative process whereby the response more likely to provide subsequent reinforcement becomes, itself, more likely. We tested these two accounts. Six pigeons responded for food reinforcers in a two-alternative switching-key concurrent schedule. Within a session, equal numbers of reinforcers were arranged for responses to each alternative. Those reinforcers strictly alternated between the two alternatives in half the conditions, and were randomly allocated to the alternatives in half the conditions. We also varied, across conditions, the alternative that became available immediately after a reinforcer. Preference after a single reinforcer always favored the immediately available alternative, regardless of the local probability of a reinforcer on that alternative (0 or 1 in the strictly alternating conditions, .5 in the random conditions). Choice then reflected the local reinforcer probabilities, suggesting some discriminative properties of reinforcement. At a more extended level, successive same-alternative reinforcers from an alternative systematically shifted preference towards that alternative, regardless of which alternative was available immediately after a reinforcer. There was no similar shift when successive reinforcers came from alternating sources. These more temporally extended results may suggest a strengthening function of reinforcement, or an enhanced ability to respond appropriately to “win–stay” contingencies over “win–shift” contingencies. PMID:21909166

Summary of evidence-based guideline: Complementary and alternative medicine in multiple sclerosis

PubMed Central

Yadav, Vijayshree; Bever, Christopher; Bowen, James; Bowling, Allen; Weinstock-Guttman, Bianca; Cameron, Michelle; Bourdette, Dennis; Gronseth, Gary S.; Narayanaswami, Pushpa

2014-01-01

Objective: To develop evidence-based recommendations for complementary and alternative medicine (CAM) in multiple sclerosis (MS). Methods: We searched the literature (1970–March 2011; March 2011−September 2013 MEDLINE search), classified articles, and linked recommendations to evidence. Results and recommendations: Clinicians might offer oral cannabis extract for spasticity symptoms and pain (excluding central neuropathic pain) (Level A). Clinicians might offer tetrahydrocannabinol for spasticity symptoms and pain (excluding central neuropathic pain) (Level B). Clinicians should counsel patients that these agents are probably ineffective for objective spasticity (short-term)/tremor (Level B) and possibly effective for spasticity and pain (long-term) (Level C). Clinicians might offer Sativex oromucosal cannabinoid spray (nabiximols) for spasticity symptoms, pain, and urinary frequency (Level B). Clinicians should counsel patients that these agents are probably ineffective for objective spasticity/urinary incontinence (Level B). Clinicians might choose not to offer these agents for tremor (Level C). Clinicians might counsel patients that magnetic therapy is probably effective for fatigue and probably ineffective for depression (Level B); fish oil is probably ineffective for relapses, disability, fatigue, MRI lesions, and quality of life (QOL) (Level B); ginkgo biloba is ineffective for cognition (Level A) and possibly effective for fatigue (Level C); reflexology is possibly effective for paresthesia (Level C); Cari Loder regimen is possibly ineffective for disability, symptoms, depression, and fatigue (Level C); and bee sting therapy is possibly ineffective for relapses, disability, fatigue, lesion burden/volume, and health-related QOL (Level C). Cannabinoids may cause adverse effects. Clinicians should exercise caution regarding standardized vs nonstandardized cannabis extracts and overall CAM quality control/nonregulation. Safety/efficacy of other CAM/CAM interaction with MS disease-modifying therapies is unknown. PMID:24663230

Summary of evidence-based guideline: complementary and alternative medicine in multiple sclerosis: report of the guideline development subcommittee of the American Academy of Neurology.

PubMed

Yadav, Vijayshree; Bever, Christopher; Bowen, James; Bowling, Allen; Weinstock-Guttman, Bianca; Cameron, Michelle; Bourdette, Dennis; Gronseth, Gary S; Narayanaswami, Pushpa

2014-03-25

To develop evidence-based recommendations for complementary and alternative medicine (CAM) in multiple sclerosis (MS). We searched the literature (1970-March 2011; March 2011-September 2013 MEDLINE search), classified articles, and linked recommendations to evidence. Clinicians might offer oral cannabis extract for spasticity symptoms and pain (excluding central neuropathic pain) (Level A). Clinicians might offer tetrahydrocannabinol for spasticity symptoms and pain (excluding central neuropathic pain) (Level B). Clinicians should counsel patients that these agents are probably ineffective for objective spasticity (short-term)/tremor (Level B) and possibly effective for spasticity and pain (long-term) (Level C). Clinicians might offer Sativex oromucosal cannabinoid spray (nabiximols) for spasticity symptoms, pain, and urinary frequency (Level B). Clinicians should counsel patients that these agents are probably ineffective for objective spasticity/urinary incontinence (Level B). Clinicians might choose not to offer these agents for tremor (Level C). Clinicians might counsel patients that magnetic therapy is probably effective for fatigue and probably ineffective for depression (Level B); fish oil is probably ineffective for relapses, disability, fatigue, MRI lesions, and quality of life (QOL) (Level B); ginkgo biloba is ineffective for cognition (Level A) and possibly effective for fatigue (Level C); reflexology is possibly effective for paresthesia (Level C); Cari Loder regimen is possibly ineffective for disability, symptoms, depression, and fatigue (Level C); and bee sting therapy is possibly ineffective for relapses, disability, fatigue, lesion burden/volume, and health-related QOL (Level C). Cannabinoids may cause adverse effects. Clinicians should exercise caution regarding standardized vs nonstandardized cannabis extracts and overall CAM quality control/nonregulation. Safety/efficacy of other CAM/CAM interaction with MS disease-modifying therapies is unknown.

Striatal activity is modulated by target probability.

PubMed

Hon, Nicholas

2017-06-14

Target probability has well-known neural effects. In the brain, target probability is known to affect frontal activity, with lower probability targets producing more prefrontal activation than those that occur with higher probability. Although the effect of target probability on cortical activity is well specified, its effect on subcortical structures such as the striatum is less well understood. Here, I examined this issue and found that the striatum was highly responsive to target probability. This is consistent with its hypothesized role in the gating of salient information into higher-order task representations. The current data are interpreted in light of that fact that different components of the striatum are sensitive to different types of task-relevant information.

Stratospheric ozone levels and their role for the dynamic response to volcanic eruptions

NASA Astrophysics Data System (ADS)

Muthers, Stefan; Anet, Julien G.; Raible, Christoph C.; Brönnimann, Stefan; Arfeuille, Florian; Peter, Tom; Rozanov, Eugene; Shapiro, Alexander; Beer, Juerg; Steinhilber, Friedhelm; Brugnara, Yuri; Schmutz, Werner

2013-04-01

The role of different background ozone climatologies for the dynamic response to tropical volcanic eruptions is analyzed using an ensemble of simulation with the atmospheric-chemistry-ocean model SOCOL/MPIOM. In this sensitivity study a single tropical eruption of Tambora-size is applied to an ensemble with either pre-industrial ozone concentrations or present day concentrations respectively. The analysis focuses on the characteristic of the Northern Europe winter warming pattern following the eruption, that has been identified after several eruptions in observations and in proxy data. The sensitivity study reveals a higher probability for a large and significant winter warming pattern with pre-industrial ozone levels, when the dynamic response of the chemistry to the eruption is disabled in the model. The positive temperature anomaly is driven by a positive NAO-like pressure pattern that lead to the advection of warm Atlantic air towards Northern Europe. With present day concentrations winter warmings are also found in some ensemble members, but overall the probability is strongly reduced. It is shown, that with pre-industial day ozone concentrations the coupling between positive anomalies of the polar vortex and the zonal wind in the troposphere is more effective, which could explain the higher likelihood of positive NAO-like pressure patterns and positive temperature anomalies in Northern Europe.

A predictive Bayesian approach to the design and analysis of bridging studies.

PubMed

Gould, A Lawrence; Jin, Tian; Zhang, Li Xin; Wang, William W B

2012-09-01

Pharmaceutical product development culminates in confirmatory trials whose evidence for the product's efficacy and safety supports regulatory approval for marketing. Regulatory agencies in countries whose patients were not included in the confirmatory trials often require confirmation of efficacy and safety in their patient populations, which may be accomplished by carrying out bridging studies to establish consistency for local patients of the effects demonstrated by the original trials. This article describes and illustrates an approach for designing and analyzing bridging studies that fully incorporates the information provided by the original trials. The approach determines probability contours or regions of joint predictive intervals for treatment effect and response variability, or endpoints of treatment effect confidence intervals, that are functions of the findings from the original trials, the sample sizes for the bridging studies, and possible deviations from complete consistency with the original trials. The bridging studies are judged consistent with the original trials if their findings fall within the probability contours or regions. Regulatory considerations determine the region definitions and appropriate probability levels. Producer and consumer risks provide a way to assess alternative region and probability choices. [Supplemental materials are available for this article. Go to the Publisher's online edition of the Journal of Biopharmaceutical Statistics for the following free supplemental resource: Appendix 2: R code for Calculations.].

Probability effects on stimulus evaluation and response processes

NASA Technical Reports Server (NTRS)

Gehring, W. J.; Gratton, G.; Coles, M. G.; Donchin, E.

1992-01-01

This study investigated the effects of probability information on response preparation and stimulus evaluation. Eight subjects responded with one hand to the target letter H and with the other to the target letter S. The target letter was surrounded by noise letters that were either the same as or different from the target letter. In 2 conditions, the targets were preceded by a warning stimulus unrelated to the target letter. In 2 other conditions, a warning letter predicted that the same letter or the opposite letter would appear as the imperative stimulus with .80 probability. Correct reaction times were faster and error rates were lower when imperative stimuli confirmed the predictions of the warning stimulus. Probability information affected (a) the preparation of motor responses during the foreperiod, (b) the development of expectancies for a particular target letter, and (c) a process sensitive to the identities of letter stimuli but not to their locations.

Gynaecomastia linked to the intake of a herbal supplement fortified with diethylstilbestrol.

PubMed

Toorians, A W F T; Bovee, T F H; De Rooy, J; Stolker, L A A M; Hoogenboom, R L A P

2010-07-01

This study reports the findings of a supplement marketed on the Internet for prostate problems. The supplement was orally taken by a 60-year-old man with divergent hormonal levels and who was surgically treated for gynaecomastia: development of abnormally large mammary glands in males. The supplement showed a strong effect in a yeast oestrogen bioassay, expressing a yeast-enhanced green fluorescent protein (yEGFP) upon exposure to oestrogens. Using both nuclear magnetic resonance (NMR) and a gradient liquid chromatographic time-of-flight mass spectrometric (LC/TOF-MS) method, the response was shown to be caused by very high levels of diethylstilbestrol, known for causing gynaecomastia. The gynaecomastia was most probably caused by this orally taken 'natural' herbal supplement, as the patient's hormonal levels also returned to normal again when stopping the use of it. This case demonstrates that physicians need to be aware of the use of supplements with illegal components that may be responsible for unwanted side-effects.

Evidence to Support Monitoring of Vedolizumab Trough Concentrations in Patients With Inflammatory Bowel Diseases.

PubMed

Dreesen, Erwin; Verstockt, Bram; Bian, Sumin; de Bruyn, Magali; Compernolle, Griet; Tops, Sophie; Noman, Maja; Van Assche, Gert; Ferrante, Marc; Gils, Ann; Vermeire, Séverine

2018-04-25

Trough concentrations of vedolizumab were found to correlate with clinical response in phase 3 studies of patients with ulcerative colitis (UC) or Crohn's disease (CD). Nevertheless, there are no solid data to support monitoring of vedolizumab trough concentrations in treated patients. We investigated the correlation between vedolizumab exposure and response in a real-world population and aimed to identify patient factors that affect exposure and response. We performed a retrospective cohort study of 179 consecutive patients (66 with UC and 113 with CD) who began vedolizumab therapy from September 1, 2015, through October 1, 2016, at University Hospitals Leuven, Belgium. Serum concentrations of vedolizumab were measured before all infusions up to week 30. Effectiveness endpoints included endoscopic healing (UC, Mayo endoscopic sub-score ≤1; CD, absence of ulcers), clinical response (physicians' global assessment), and biologic response or remission (based on level of C-reactive protein) and were assessed at week 14 (for patients with UC) and week 22 (for patients with CD). A stepwise forward addition-backward elimination modeling approach was performed to identify factors independently associated with vedolizumab exposure and response. Vedolizumab trough concentrations >30.0 μg/mL at week 2, >24.0 μg/mL at week 6, and >14.0 μg/mL during maintenance therapy associated with a higher probability of attaining the effectiveness endpoints for patients with UC or CD (P < .05). Higher body mass and more severe disease (based on high level of C-reactive protein and low level of albumin and/or hemoglobin) at the start of vedolizumab therapy associated with lower trough concentrations of vedolizumab over the 30-week period and a lower probability of achieving mucosal healing (P < .05). Mucosal healing was achieved in significantly more patients with UC than patients with CD, even though a diagnosis of UC was not an independent predictor of higher vedolizumab trough concentrations. In a retrospective study of 179 patients with CD or UC, we observed a correlation between vedolizumab exposure and response. These findings support monitoring of vedolizumab trough concentrations to predict patients' outcome. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Perception of multi-stable dot lattices in the visual periphery: an effect of internal positional noise.

PubMed

Põder, Endel

2011-02-16

Dot lattices are very simple multi-stable images where the dots can be perceived as being grouped in different ways. The probabilities of grouping along different orientations as dependent on inter-dot distances along these orientations can be predicted by a simple quantitative model. L. Bleumers, P. De Graef, K. Verfaillie, and J. Wagemans (2008) found that for peripheral presentation, this model should be combined with random guesses on a proportion of trials. The present study shows that the probability of random responses decreases with decreasing ambiguity of lattices and is different for bi-stable and tri-stable lattices. With central presentation, similar effects can be produced by adding positional noise to the dots. The results suggest that different levels of internal positional noise might explain the differences between peripheral and central proximity grouping.

The effects of neighborhood views containing multiple environmental features on road traffic noise perception at dwellings.

PubMed

Leung, T M; Xu, J M; Chau, C K; Tang, S K; Pun-Cheng, L S C

2017-04-01

The importance of non-acoustical factors including the type of visual environment on human noise perception becomes increasingly recognized. In order to reveal the relationships between long-term noise annoyance and different types of neighborhood views, 2033 questionnaire responses were collected for studying the effect of perceptions of different combinations of views of sea, urban river, greenery, and/or noise barrier on the annoyance responses from residents living in high-rise apartments in Hong Kong. The collected responses were employed to formulate a multivariate model to predict the probability of invoking a high annoyance response from residents. Results showed that views of sea, urban river, or greenery could lower the probability, while views of noise barrier could increase the probability. Views of greenery had a stronger noise moderation capability than views of sea or urban river. The presence of an interaction effect between views of water and views of noise barrier exerted a negative influence on the noise annoyance moderation capability. The probability due to exposure to an environment containing views of noise barriers and urban rivers would be even higher than that due to exposure to an environment containing views of noise barriers alone.

Experimental pancreatic hyperplasia and neoplasia: effects of dietary and surgical manipulation.

PubMed Central

Watanapa, P.; Williamson, R. C.

1993-01-01

Several studies carried out during the past two decades have investigated the effect of dietary and surgical manipulation on pancreatic growth and carcinogenesis. Diets high in trypsin inhibitor stimulate pancreatic growth and increase the formation of preneoplastic lesions and carcinomas in the rat pancreas. Cholecystokinin (CCK) is the key intermediary in this response, since both natural and synthetic trypsin inhibitors increase circulating levels of the hormone and CCK antagonists largely prevent these changes. Fatty acids enhance pancreatic carcinogenesis in both rats and hamsters, whereas protein appears to have a protective role in the rat, but to increase tumour yields in the hamster. Several surgical operations affect the pancreas. Pancreatobiliary diversion and partial gastrectomy stimulate pancreatic growth and enhance carcinogenesis, probably by means of increased CCK release. Complete duodenogastric reflux has similar effects on the pancreas but the gut peptide involved is gastrin. Although massive small bowel resection increases pancreatic growth, the marked reduction in caloric absorption probably explains its failure to enhance carcinogenesis. CCK and enteroglucagon might work in concert to modulate the tropic response of the pancreas to small bowel resection. In the pancreas, as in the large intestine, hyperplasia appears to precede and predispose to neoplasia. PMID:8494719

Fear appeals and attitude change: effects of a threat's noxiousness, probability of occurrence, and the efficacy of coping responses.

PubMed

Rogers, R W; Mewborn, C R

1976-07-01

Three factorial experiments examined the persuasive effects of the noxiousness of threatened event, its probability of occurrence, and the efficacy of recommended protective measures. A total of 176 students participated in separate studies on the topics of cigarette smoking, driving safety, and venereal disease. The results disclosed that increments in the efficacy variable increased intentions to adopt the efficacy variable increased intentions to adopt the recommended practices. Interaction effects revealed that when the preventive practices were effective, increments in the noxiousness and probability variables facilitated attitude change; however, when the coping responses were the preventive practices were effective, increments in the noxiousness and probability either had no effect or a deleterious effect, respectively. These interaction effects were discussed in terms of a defensive avoidance hypothesis, the crucial component of which was an inability to ward off the danger. Furthermore, the effect of the emotion of fear upon intentions was found to be mediated by the cognitive appraisal of severity of the threat. Finally, similarities with and extensions of previous studies were reviewed.

Comparison of Annoyance from Railway Noise and Railway Vibration

PubMed Central

Gidlöf-Gunnarsson, Anita; Gustavsson, Sara

2017-01-01

The aim of this study is to compare vibration exposure to noise exposure from railway traffic in terms of equal annoyance, i.e., to determine when a certain noise level is equally annoying as a corresponding vibration velocity. Based on questionnaire data from the Train Vibration and Noise Effects (TVANE) research project from residential areas exposed to railway noise and vibration, the dose response relationship for annoyance was estimated. By comparing the relationships between exposure and annoyance for areas both with and without significant vibration exposure, the noise levels and vibration velocities that had an equal probability of causing annoyance was determined using logistic regression. The comparison gives a continuous mapping between vibration velocity in the ground and a corresponding noise level at the facade that are equally annoying. For equivalent noise level at the facade compared to maximum weighted vibration velocity in the ground the probability of annoyance is approximately 20% for 59 dB or 0.48 mm/s, and about 40% for 63 dB or 0.98 mm/s. PMID:28753921

Dynamic Encoding of Speech Sequence Probability in Human Temporal Cortex

PubMed Central

Leonard, Matthew K.; Bouchard, Kristofer E.; Tang, Claire

2015-01-01

Sensory processing involves identification of stimulus features, but also integration with the surrounding sensory and cognitive context. Previous work in animals and humans has shown fine-scale sensitivity to context in the form of learned knowledge about the statistics of the sensory environment, including relative probabilities of discrete units in a stream of sequential auditory input. These statistics are a defining characteristic of one of the most important sequential signals humans encounter: speech. For speech, extensive exposure to a language tunes listeners to the statistics of sound sequences. To address how speech sequence statistics are neurally encoded, we used high-resolution direct cortical recordings from human lateral superior temporal cortex as subjects listened to words and nonwords with varying transition probabilities between sound segments. In addition to their sensitivity to acoustic features (including contextual features, such as coarticulation), we found that neural responses dynamically encoded the language-level probability of both preceding and upcoming speech sounds. Transition probability first negatively modulated neural responses, followed by positive modulation of neural responses, consistent with coordinated predictive and retrospective recognition processes, respectively. Furthermore, transition probability encoding was different for real English words compared with nonwords, providing evidence for online interactions with high-order linguistic knowledge. These results demonstrate that sensory processing of deeply learned stimuli involves integrating physical stimulus features with their contextual sequential structure. Despite not being consciously aware of phoneme sequence statistics, listeners use this information to process spoken input and to link low-level acoustic representations with linguistic information about word identity and meaning. PMID:25948269

Predictors of Response to Web-Based Cognitive Behavioral Therapy With High-Intensity Face-to-Face Therapist Guidance for Depression: A Bayesian Analysis

PubMed Central

Mittner, Matthias; Lillevoll, Kjersti; Katla, Susanne Kvam; Kolstrup, Nils; Eisemann, Martin; Friborg, Oddgeir; Waterloo, Knut

2015-01-01

Background Several studies have demonstrated the effect of guided Internet-based cognitive behavioral therapy (ICBT) for depression. However, ICBT is not suitable for all depressed patients and there is a considerable level of nonresponse. Research on predictors and moderators of outcome in ICBT is inconclusive. Objective This paper explored predictors of response to an intervention combining the Web-based program MoodGYM and face-to-face therapist guidance in a sample of primary care patients with mild to moderate depressive symptoms. Methods Participants (N=106) aged between 18 and 65 years were recruited from primary care and randomly allocated to a treatment condition or to a delayed treatment condition. The intervention included the Norwegian version of the MoodGYM program, face-to-face guidance from a psychologist, and reminder emails. In this paper, data from the treatment phase of the 2 groups was merged to increase the sample size (n=82). Outcome was improvement in depressive symptoms during treatment as assessed with the Beck Depression Inventory-II (BDI-II). Predictors included demographic variables, severity variables (eg, number of depressive episodes and pretreatment depression and anxiety severity), cognitive variables (eg, dysfunctional thinking), module completion, and treatment expectancy and motivation. Using Bayesian analysis, predictors of response were explored with a latent-class approach and by analyzing whether predictors affected the slope of response. Results A 2-class model distinguished well between responders (74%, 61/82) and nonresponders (26%, 21/82). Our results indicate that having had more depressive episodes, being married or cohabiting, and scoring higher on a measure of life satisfaction had high odds for positively affecting the probability of response. Higher levels of dysfunctional thinking had high odds for a negative effect on the probability of responding. Prediction of the slope of response yielded largely similar results. Bayes factors indicated substantial evidence that being married or cohabiting predicted a more positive treatment response. The effects of life satisfaction and number of depressive episodes were more uncertain. There was substantial evidence that several variables were unrelated to treatment response, including gender, age, and pretreatment symptoms of depression and anxiety. Conclusions Treatment response to ICBT with face-to-face guidance may be comparable across varying levels of depressive severity and irrespective of the presence and severity of comorbid anxiety. Being married or cohabiting, reporting higher life satisfaction, and having had more depressive episodes may predict a more favorable response, whereas higher levels of dysfunctional thinking may be a predictor of poorer response. More studies exploring predictors and moderators of Internet-based treatments are needed to inform for whom this treatment is most effective. Trial Registration Australian New Zealand Clinical Trials Registry number: ACTRN12610000257066; https://www.anzctr.org.au/trial_view.aspx?id=335255 (Archived by WebCite at http://www.webcitation.org/6GR48iZH4). PMID:26333818

d-serine levels in Alzheimer's disease: implications for novel biomarker development

PubMed Central

Madeira, C; Lourenco, M V; Vargas-Lopes, C; Suemoto, C K; Brandão, C O; Reis, T; Leite, R E P; Laks, J; Jacob-Filho, W; Pasqualucci, C A; Grinberg, L T; Ferreira, S T; Panizzutti, R

2015-01-01

Alzheimer's disease (AD) is a severe neurodegenerative disorder still in search of effective methods of diagnosis. Altered levels of the NMDA receptor co-agonist, d-serine, have been associated with neurological disorders, including schizophrenia and epilepsy. However, whether d-serine levels are deregulated in AD remains elusive. Here, we first measured D-serine levels in post-mortem hippocampal and cortical samples from nondemented subjects (n=8) and AD patients (n=14). We next determined d-serine levels in experimental models of AD, including wild-type rats and mice that received intracerebroventricular injections of amyloid-β oligomers, and APP/PS1 transgenic mice. Finally, we assessed d-serine levels in the cerebrospinal fluid (CSF) of 21 patients with a diagnosis of probable AD, as compared with patients with normal pressure hydrocephalus (n=9), major depression (n=9) and healthy controls (n=10), and results were contrasted with CSF amyloid-β/tau AD biomarkers. d-serine levels were higher in the hippocampus and parietal cortex of AD patients than in control subjects. Levels of both d-serine and serine racemase, the enzyme responsible for d-serine production, were elevated in experimental models of AD. Significantly, d-serine levels were higher in the CSF of probable AD patients than in non-cognitively impaired subject groups. Combining d-serine levels to the amyloid/tau index remarkably increased the sensitivity and specificity of diagnosis of probable AD in our cohort. Our results show that increased brain and CSF d-serine levels are associated with AD. CSF d-serine levels discriminated between nondemented and AD patients in our cohort and might constitute a novel candidate biomarker for early AD diagnosis. PMID:25942042

[Influence, in normal subjects, of an isocaloric hyperprotein diet on cortisol, ACTH, GH and PRL response to lysine-8-vasopressin].

PubMed

Giovannini, C; Sellini, M; Manzo, G; Barletta, C; Scavo, D

1981-12-30

The Lysin-8-Vasopressin test has been experimented in ten healthy subjects during normocaloric balanced diet and after hyperproteic-normocaloric diet. The levels of ACTH, Cortisol and GH are significantly more elevated after hyperproteic-normocaloric diet than in basal conditions. The levels of Prolactin do not show any remarkable change. These results can indicate the increased reactivity of the diencephalon-hypophysis-adrenal axis and of the hormones connected with the mechanisms of homeostasis and stress, probably correlated to more disposable proteic material and to the metabolic effects which follow.

The precise time course of lexical activation: MEG measurements of the effects of frequency, probability, and density in lexical decision.

PubMed

Stockall, Linnaea; Stringfellow, Andrew; Marantz, Alec

2004-01-01

Visually presented letter strings consistently yield three MEG response components: the M170, associated with letter-string processing (Tarkiainen, Helenius, Hansen, Cornelissen, & Salmelin, 1999); the M250, affected by phonotactic probability, (Pylkkänen, Stringfellow, & Marantz, 2002); and the M350, responsive to lexical frequency (Embick, Hackl, Schaeffer, Kelepir, & Marantz, 2001). Pylkkänen et al. found evidence that the M350 reflects lexical activation prior to competition among phonologically similar words. We investigate the effects of lexical and sublexical frequency and neighborhood density on the M250 and M350 through orthogonal manipulation of phonotactic probability, density, and frequency. The results confirm that probability but not density affects the latency of the M250 and M350; however, an interaction between probability and density on M350 latencies suggests an earlier influence of neighborhoods than previously reported.

Age-specific reproductive success in a long-lived bird: do older parents resist stress better?

PubMed

Angelier, Frederic; Moe, Børge; Weimerskirch, Henri; Chastel, Olivier

2007-11-01

In many vertebrates, reproductive performance increases with advancing age but mechanisms involved in such a pattern remain poorly studied. One potential mechanism may be the hormonal stress response, which shifts energy investment away from reproduction and redirects it towards survival. In birds, this stress response is achieved through a release of corticosterone and is also accompanied by a decrease in circulating prolactin, a hormone involved widely in regulating parental cares. It has been predicted that, when the value of the current reproduction is high relative to the value of future reproduction and survival, as it is expected to be in older adults, the stress response should be attenuated to ensure that reproduction is not inhibited. We tested this hypothesis by measuring the corticosterone and prolactin responses of known-age (8-36 years old) incubating snow petrels (Pagadroma nivea) to a standardized capture/handling stress protocol. We also investigated whether an attenuation of the stress responses will correlate with a lower occurrence of egg neglect, a frequently observed behaviour in snow petrels. The probability of successfully fledging a chick increased from 6 years to 12 years before stabilizing after 12 years of age. Corticosterone response to stress was unaffected by age. Prolactin response to stress, however, was influenced clearly by age: in both sexes older breeders had higher stress-induced prolactin levels than younger ones. This was due to an increasing attenuation of the prolactin response to stress with advancing age in females, and in males this was due to a probably higher intrinsic capacity of older males to secrete prolactin. Moreover, higher stress-induced prolactin levels were correlated with a lower probability of neglecting the egg. In young breeders, the combination of a robust corticosterone increase with a lower ability to maintain prolactin secretion during acute stress is probably one of the functional causes of their lower incubation commitment. We suggest that the ability to maintain a threshold level of prolactin during a stressful situation may be an important physiological mechanism involved in the improvement of reproductive performance with advancing age in long-lived birds.

Surveillance guidelines for disease elimination: a case study of canine rabies.

PubMed

Townsend, Sunny E; Lembo, Tiziana; Cleaveland, Sarah; Meslin, François X; Miranda, Mary Elizabeth; Putra, Anak Agung Gde; Haydon, Daniel T; Hampson, Katie

2013-05-01

Surveillance is a critical component of disease control programmes but is often poorly resourced, particularly in developing countries lacking good infrastructure and especially for zoonoses which require combined veterinary and medical capacity and collaboration. Here we examine how successful control, and ultimately disease elimination, depends on effective surveillance. We estimated that detection probabilities of <0.1 are broadly typical of rabies surveillance in endemic countries and areas without a history of rabies. Using outbreak simulation techniques we investigated how the probability of detection affects outbreak spread, and outcomes of response strategies such as time to control an outbreak, probability of elimination, and the certainty of declaring freedom from disease. Assuming realistically poor surveillance (probability of detection <0.1), we show that proactive mass dog vaccination is much more effective at controlling rabies and no more costly than campaigns that vaccinate in response to case detection. Control through proactive vaccination followed by 2 years of continuous monitoring and vaccination should be sufficient to guarantee elimination from an isolated area not subject to repeat introductions. We recommend that rabies control programmes ought to be able to maintain surveillance levels that detect at least 5% (and ideally 10%) of all cases to improve their prospects of eliminating rabies, and this can be achieved through greater intersectoral collaboration. Our approach illustrates how surveillance is critical for the control and elimination of diseases such as canine rabies and can provide minimum surveillance requirements and technical guidance for elimination programmes under a broad-range of circumstances. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluating coastal landscape response to sea-level rise in the northeastern United States: approach and methods

USGS Publications Warehouse

Lentz, Erika E.; Stippa, Sawyer R.; Thieler, E. Robert; Plant, Nathaniel G.; Gesch, Dean B.; Horton, Radley M.

2014-02-13

The U.S. Geological Survey is examining effects of future sea-level rise on the coastal landscape from Maine to Virginia by producing spatially explicit, probabilistic predictions using sea-level projections, vertical land movement rates (due to isostacy), elevation data, and land-cover data. Sea-level-rise scenarios used as model inputs are generated by using multiple sources of information, including Coupled Model Intercomparison Project Phase 5 models following representative concentration pathways 4.5 and 8.5 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. A Bayesian network is used to develop a predictive coastal response model that integrates the sea-level, elevation, and land-cover data with assigned probabilities that account for interactions with coastal geomorphology as well as the corresponding ecological and societal systems it supports. The effects of sea-level rise are presented as (1) level of landscape submergence and (2) coastal response type characterized as either static (that is, inundation) or dynamic (that is, landform or landscape change). Results are produced at a spatial scale of 30 meters for four decades (the 2020s, 2030s, 2050s, and 2080s). The probabilistic predictions can be applied to landscape management decisions based on sea-level-rise effects as well as on assessments of the prediction uncertainty and need for improved data or fundamental understanding. This report describes the methods used to produce predictions, including information on input datasets; the modeling approach; model outputs; data-quality-control procedures; and information on how to access the data and metadata online.

Evaluating Coastal Landscape Response to Sea-Level Rise in the Northeastern United States - Approach and Methods

NASA Technical Reports Server (NTRS)

Lentz, Erika E.; Stippa, Sawyer R.; Thieler, E. Robert; Plant, Nathaniel G.; Gesch, Dean B.; Horton, Radley M.

2015-01-01

The U.S. Geological Survey is examining effects of future sea-level rise on the coastal landscape from Maine to Virginia by producing spatially explicit, probabilistic predictions using sea-level projections, vertical land movement rates (due to isostacy), elevation data, and land-cover data. Sea-level-rise scenarios used as model inputs are generated by using multiple sources of information, including Coupled Model Intercomparison Project Phase 5 models following representative concentration pathways 4.5 and 8.5 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. A Bayesian network is used to develop a predictive coastal response model that integrates the sea-level, elevation, and land-cover data with assigned probabilities that account for interactions with coastal geomorphology as well as the corresponding ecological and societal systems it supports. The effects of sea-level rise are presented as (1) level of landscape submergence and (2) coastal response type characterized as either static (that is, inundation) or dynamic (that is, landform or landscape change). Results are produced at a spatial scale of 30 meters for four decades (the 2020s, 2030s, 2050s, and 2080s). The probabilistic predictions can be applied to landscape management decisions based on sea-level-rise effects as well as on assessments of the prediction uncertainty and need for improved data or fundamental understanding. This report describes the methods used to produce predictions, including information on input datasets; the modeling approach; model outputs; data-quality-control procedures; and information on how to access the data and metadata online.

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

Immediate and subsequent effects of response interruption and redirection on targeted and untargeted forms of stereotypy.

PubMed

Pastrana, Sarah J; Rapp, John T; Frewing, Tyla M

2013-07-01

A number of studies have shown that response interruption and redirection (RIRD) decreases immediate engagement in targeted stereotypic behaviors; however, its effects on untargeted stereotypy have not yet been studied, and its effects following removal of treatment are unclear. We evaluated the immediate and subsequent effects of RIRD on targeted motor stereotypy, as well as untargeted but higher probability vocal stereotypy, of two participants diagnosed with autism, using a three-component multiple-schedule design. Treatment with RIRD decreased immediate engagement in motor stereotypy for both participants, and did not increase subsequent engagement above baseline levels for either participant. In addition, RIRD produced modest changes in immediate engagement in untargeted vocal stereotypy for both participants. We briefly discuss the clinical implications and limitations of the findings from this study.

Event related potentials during covert orientation of visual attention: effects of cue validity and directionality.

PubMed

Wright, M J; Geffen, G M; Geffen, L B

1995-10-01

Covert orientation of attention was studied in 30 adults who fixated warning cues and pressed a button at target onset. Directional cues (arrows) indicated the most probable (p = 0.8) side of target occurrence. Subjects responded fastest when validly cued, slowest to invalidly cued targets, and at an intermediate rate when the cue (a cross) was not directional. Directional cues took longer to evaluate (increased N1 and P2 latencies) and produced more focussed attention and greater response preparation (enhanced CNV and P3 amplitude) than non-directional cues. These findings indicate that the expectancy of a target can be manipulated by a spatial cue at three levels, sensory, attention, and response preparation, and lead to changes in the sensory perceptual processing of the target. Validly cued targets produced an increase in P1 amplitude reflecting attention enhanced sensory processing whereas invalidly cued targets increased N1 and P3 amplitudes reflecting the re-orientation of attention, and further processing and updating of information required of low probability stimuli respectively. P3 latency to invalidly cued targets was also delayed reflecting the additional processes required to shift attention to a new location. The P3 latency validity effect was smaller than that found for response time suggesting response execution may also be affected by spatial attention.

Human Lung Cancer Risks from Radon – Part III - Evidence of Influence of Combined Bystander and Adaptive Response Effects on Radon Case-Control Studies - A Microdose Analysis

PubMed Central

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2012-01-01

Since the publication of the BEIR VI (1999) report on health risks from radon, a significant amount of new data has been published showing various mechanisms that may affect the ultimate assessment of radon as a carcinogen, in particular the potentially deleterious Bystander Effect (BE) and the potentially beneficial Adaptive Response radio-protection (AR). The case-control radon lung cancer risk data of the pooled 13 European countries radon study (Darby et al 2005, 2006) and the 8 North American pooled study (Krewski et al 2005, 2006) have been evaluated. The large variation in the odds ratios of lung cancer from radon risk is reconciled, based on the large variation in geological and ecological conditions and variation in the degree of adaptive response radio-protection against the bystander effect induced lung damage. The analysis clearly shows Bystander Effect radon lung cancer induction and Adaptive Response reduction in lung cancer in some geographical regions. It is estimated that for radon levels up to about 400 Bq m−3 there is about a 30% probability that no human lung cancer risk from radon will be experienced and a 20% probability that the risk is below the zero-radon, endogenic spontaneous or perhaps even genetically inheritable lung cancer risk rate. The BEIR VI (1999) and EPA (2003) estimates of human lung cancer deaths from radon are most likely significantly excessive. The assumption of linearity of risk, by the Linear No-Threshold Model, with increasing radon exposure is invalid. PMID:22942874

Neural response to reward anticipation under risk is nonlinear in probabilities.

PubMed

Hsu, Ming; Krajbich, Ian; Zhao, Chen; Camerer, Colin F

2009-02-18

A widely observed phenomenon in decision making under risk is the apparent overweighting of unlikely events and the underweighting of nearly certain events. This violates standard assumptions in expected utility theory, which requires that expected utility be linear (objective) in probabilities. Models such as prospect theory have relaxed this assumption and introduced the notion of a "probability weighting function," which captures the key properties found in experimental data. This study reports functional magnetic resonance imaging (fMRI) data that neural response to expected reward is nonlinear in probabilities. Specifically, we found that activity in the striatum during valuation of monetary gambles are nonlinear in probabilities in the pattern predicted by prospect theory, suggesting that probability distortion is reflected at the level of the reward encoding process. The degree of nonlinearity reflected in individual subjects' decisions is also correlated with striatal activity across subjects. Our results shed light on the neural mechanisms of reward processing, and have implications for future neuroscientific studies of decision making involving extreme tails of the distribution, where probability weighting provides an explanation for commonly observed behavioral anomalies.

Parental educational practices in relation to children's anxiety disorder-related behavior.

PubMed

Mellon, Robert C; Moutavelis, Adrianos G

2011-08-01

Schoolchildren reported their parents' use of aversive control and positive reinforcement contingencies in their educational interventions, as well as parental non-responsiveness to their requests for educational assistance. They also reported their own levels of six dimensions of anxiety disorder-related phenomena. Both parental use of aversive control and non-responsiveness were directly related to overall levels of child anxiety disorder-related behavior; these correlations were more robust than those observed in previous investigations of more diffuse dimensions of parenting style and trait anxiety. Panic disorder/agoraphobia and Generalized anxiety disorder were the dimensions most strongly correlated with both parental aversive control and non-responsiveness, while Compulsive behavior was uniquely uncorrelated with parental non-responsiveness and uniquely correlated with parental use of positive reinforcement contingencies. Differences in the magnitudes of correlations between anxiety disorder-related dimensions and parental educational practices are interpreted in terms of the probable differential effectiveness of their constituent behaviors in terminating parent-mediated negative reinforcers. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of stop-signal probability in the stop-signal paradigm: the N2/P3 complex further validated.

PubMed

Ramautar, J R; Kok, A; Ridderinkhof, K R

2004-11-01

The aim of this study was to examine the effects of frequency of occurrence of stop signals in the stop-signal paradigm. Presenting stop signals less frequently resulted in faster reaction times to the go stimulus and a lower probability of inhibition. Also, go stimuli elicited larger and somewhat earlier P3 responses when stop signals occurred less frequently. Since the amplitude effect was more pronounced on trials when go signals were followed by fast than slow reactions, it probably reflected a stronger set to produce fast responses. N2 and P3 components to stop signals were observed to be larger and of longer latency when stop signals occurred less frequently. The amplitude enhancement of these N2 and P3 components were more pronounced for unsuccessful than for successful stop-signal trials. Moreover, the successfully inhibited stop trials elicited a frontocentral P3 whereas unsuccessfully inhibited stop trials elicited a more posterior P3 that resembled the classical P3b. P3 amplitude in the unsuccessfully inhibited condition also differed between waveforms synchronized with the stop signal and waveforms synchronized with response onset whereas N2 amplitude did not. Taken together these findings suggest that N2 reflected a greater significance of failed inhibitions after low probability stop signals while P3 reflected continued processing of the erroneous response after response execution.

The Precise Time Course of Lexical Activation: MEG Measurements of the Effects of Frequency, Probability, and Density in Lexical Decision

ERIC Educational Resources Information Center

Stockall, Linnaea; Stringfellow, Andrew; Marantz, Alec

2004-01-01

Visually presented letter strings consistently yield three MEG response components: the M170, associated with letter-string processing (Tarkiainen, Helenius, Hansen, Cornelissen, & Salmelin, 1999); the M250, affected by phonotactic probability, (Pylkkanen, Stringfellow, & Marantz, 2002); and the M350, responsive to lexical frequency (Embick,…

The effects of proficiency and bias on residents' interpretation of the microscopic urinalysis.

PubMed

Flach, Stephen D; Canaris, Gay J; Tape, Thomas G; Huntley, Kathryn M; Wigton, Robert S

2002-01-01

This study aims to determine whether residents are influenced by clinical information when interpreting microscopic urinalysis (UA) and estimating the probability of a urinary tract infection (UTI), and to determine the accuracy and reliability of UA readings. Residents estimated the UA white blood cell count and the probability of a UTI in vignettes using a fractional factorial design, varying symptoms, gender, and the white blood cell count on preprepared urine slides. Individual-level results indicated a clinical information bias and poor accuracy. Seventeen of 38 residents increased the white blood cell count in response to female gender; 14 increased the white blood cell count in response to UTI symptoms. Forty-nine percent of the readings were inaccurate; agreement ranged from 50% to 67% for white and red blood cells and bacteria. Many residents gave inaccurate UA readings, and many readings varied with clinical information. A significant portion of residents needs assistance in objectively and accurately interpreting the UA.

Continuous-Time Monitoring of Landau-Zener Interference in a Cooper-Pair Box

NASA Astrophysics Data System (ADS)

Sillanpää, Mika; Lehtinen, Teijo; Paila, Antti; Makhlin, Yuriy; Hakonen, Pertti

2006-05-01

Landau-Zener (LZ) tunneling can occur with a certain probability when crossing energy levels of a quantum two-level system are swept across the minimum energy separation. Here we present experimental evidence of quantum interference effects in solid-state LZ tunneling. We used a Cooper-pair box qubit where the LZ tunneling occurs at the charge degeneracy. By employing a weak nondemolition monitoring, we observe interference between consecutive LZ-tunneling events; we find that the average level occupancies depend on the dynamical phase. The system’s unusually strong linear response is explained by interband relaxation. Our interferometer can be used as a high-resolution Mach-Zehnder type detector for phase and charge.

Continuous-time monitoring of Landau-Zener interference in a cooper-pair box.

PubMed

Sillanpää, Mika; Lehtinen, Teijo; Paila, Antti; Makhlin, Yuriy; Hakonen, Pertti

2006-05-12

Landau-Zener (LZ) tunneling can occur with a certain probability when crossing energy levels of a quantum two-level system are swept across the minimum energy separation. Here we present experimental evidence of quantum interference effects in solid-state LZ tunneling. We used a Cooper-pair box qubit where the LZ tunneling occurs at the charge degeneracy. By employing a weak nondemolition monitoring, we observe interference between consecutive LZ-tunneling events; we find that the average level occupancies depend on the dynamical phase. The system's unusually strong linear response is explained by interband relaxation. Our interferometer can be used as a high-resolution Mach-Zehnder-type detector for phase and charge.

Import risk assessment incorporating a dose-response model: introduction of highly pathogenic porcine reproductive and respiratory syndrome into Australia via illegally imported raw pork.

PubMed

Brookes, V J; Hernández-Jover, M; Holyoake, P; Ward, M P

2014-03-01

Highly pathogenic porcine reproductive and respiratory syndrome (PRRS) has spread through parts of south-east Asia, posing a risk to Australia. The objective of this study was to assess the probability of infection of a feral or domestic pig in Australia with highly pathogenic PRRS following ingestion of illegally imported raw pork. A conservative scenario was considered in which 500 g of raw pork was imported from the Philippines into Australia without being detected by border security, then discarded from a household and potentially accessed by a pig. Monte Carlo simulation of a two-dimensional, stochastic model was used to estimate the probability of entry and exposure, and the probability of infection was assessed by incorporating a virus-decay and mechanistic dose-response model. Results indicated that the probability of infection of a feral pig after ingestion of raw meat was higher than the probability of infection of a domestic pig. Sensitivity analysis was used to assess the influence of input parameters on model output probability estimates, and extension of the virus-decay and dose-response model was used to explore the impact of different temperatures and time from slaughter to ingestion of the meat, different weights of meat, and the level of viraemia at slaughter on the infectivity of meat. Parameters with the highest influence on the model output were the level of viraemia of a pig prior to slaughter and the probability of access by a feral pig to food-waste discarded on property surrounding a household. Extension of the decay and dose-response model showed that small pieces of meat (10 g) from a highly pathogenic PRRS viraemic pig could contain enough virus to have a high probability of infection of a pig, and that routes to Australia by sea or air from all highly pathogenic PRRS virus endemic countries were of interest dependent on the temperature of the raw meat during transport. This study highlighted the importance of mitigation strategies such as disposal of food-waste from international traffic as quarantine waste, and the need for further research into the probability of access to food-waste on properties by feral pigs. Copyright © 2014 Elsevier B.V. All rights reserved.

Concurrent variation of response bias and sensitivity in an operant-psychophysical test.

NASA Technical Reports Server (NTRS)

Terman, M.; Terman, J. S.

1972-01-01

The yes-no signal detection procedure was applied to a single-response operant paradigm in which rats discriminated between a standard auditory intensity and attenuated comparison values. The payoff matrix was symmetrical (with reinforcing brain stimulation for correct detections and brief time-out for errors), but signal probability and intensity differences were varied to generate a family of isobias and isosensitivity functions. The d' parameter remained fairly constant across a wide range of bias levels. Isobias functions deviated from a strict matching strategy as discrimination difficulty increased, although an orderly relation was maintained between signal probability value and the degree and direction of response bias.

Relationship between virological response and FIB-4 index in chronic hepatitis B patients with entecavir therapy.

PubMed

Li, Ni; Xu, Jing-Hang; Yu, Min; Wang, Sa; Si, Chong-Wen; Yu, Yan-Yan

2015-11-21

To investigate whether long-term low-level hepatitis B virus (HBV) DNA influences dynamic changes of the FIB-4 index in chronic hepatitis B (CHB) patients receiving entecavir (ETV) therapy with partial virological responses. We retrospectively analyzed 231 nucleos(t)ide (NA) naïve CHB patients from our previous study (NCT01926288) who received continuous ETV or ETV maleate therapy for three years. The patients were divided into partial virological response (PVR) and complete virological response (CVR) groups according to serum HBV DNA levels at week 48. Seventy-six patients underwent biopsies at baseline and at 48 wk. The performance of the FIB-4 index and area under the receiver operating characteristic (AUROC) curve for predicting fibrosis were determined for the patients undergoing biopsy. The primary objective of the study was to compare the cumulative probabilities of virological responses between the two groups during the treatment period. The secondary outcome was to observe dynamic changes of the FIB-4 index between CVR patients and PVR patients. For hepatitis B e antigen (HBeAg)-positive patients (n = 178), the cumulative probability of achieving undetectable levels at week 144 was 95% and 69% for CVR and PVR patients, respectively (P < 0.001). In the Cox proportional hazards model, a lower pretreatment serum HBV DNA level was an independent factor predicting maintained viral suppression. The cumulative probability of achieving undetectable levels of HBV DNA for HBeAg-negative patients (n = 53) did not differ between the two groups. The FIB-4 index efficiently identified fibrosis, with an AUROC of 0.80 (95%CI: 0.69-0.89). For HBeAg-positive patients, the FIB-4 index was higher in CVR patients than in PVR patients at baseline (1.89 ± 1.43 vs 1.18 ± 0.69, P < 0.001). There was no significant difference in the reduction of the FIB-4 index between the CVR and PVR groups from weeks 48 to 144 (-0.11 ± 0.47 vs -0.13 ± 0.49, P = 0.71). At week 144, the FIB-4 index levels were similar between the two groups (1.24 ± 0.87 vs 1.02 ± 0.73, P = 0.06). After multivariate logistic regression analysis, a lower baseline serum HBV DNA level was associated with improvement of liver fibrosis. In HBeAg-negative patients, the FIB-4 index did not differ between the two groups. The cumulative probabilities of HBV DNA responses showed significant differences between CVR and PVR HBeAg-positive CHB patients undergoing entecavir treatment for 144 wk. However, long-term low-level HBV DNA did not deteriorate the FIB-4 index, which was used to evaluate liver fibrosis, at the end of three years.

Effects of preparation time and trial type probability on performance of anti- and pro-saccades.

PubMed

Pierce, Jordan E; McDowell, Jennifer E

2016-02-01

Cognitive control optimizes responses to relevant task conditions by balancing bottom-up stimulus processing with top-down goal pursuit. It can be investigated using the ocular motor system by contrasting basic prosaccades (look toward a stimulus) with complex antisaccades (look away from a stimulus). Furthermore, the amount of time allotted between trials, the need to switch task sets, and the time allowed to prepare for an upcoming saccade all impact performance. In this study the relative probabilities of anti- and pro-saccades were manipulated across five blocks of interleaved trials, while the inter-trial interval and trial type cue duration were varied across subjects. Results indicated that inter-trial interval had no significant effect on error rates or reaction times (RTs), while a shorter trial type cue led to more antisaccade errors and faster overall RTs. Responses following a shorter cue duration also showed a stronger effect of trial type probability, with more antisaccade errors in blocks with a low antisaccade probability and slower RTs for each saccade task when its trial type was unlikely. A longer cue duration yielded fewer errors and slower RTs, with a larger switch cost for errors compared to a short cue duration. Findings demonstrated that when the trial type cue duration was shorter, visual motor responsiveness was faster and subjects relied upon the implicit trial probability context to improve performance. When the cue duration was longer, increased fixation-related activity may have delayed saccade motor preparation and slowed responses, guiding subjects to respond in a controlled manner regardless of trial type probability. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced reliability methods for structural evaluation

NASA Technical Reports Server (NTRS)

Wirsching, P. H.; Wu, Y.-T.

1985-01-01

Fast probability integration (FPI) methods, which can yield approximate solutions to such general structural reliability problems as the computation of the probabilities of complicated functions of random variables, are known to require one-tenth the computer time of Monte Carlo methods for a probability level of 0.001; lower probabilities yield even more dramatic differences. A strategy is presented in which a computer routine is run k times with selected perturbed values of the variables to obtain k solutions for a response variable Y. An approximating polynomial is fit to the k 'data' sets, and FPI methods are employed for this explicit form.

Different behavioral effect dose–response profiles in mice exposed to two-carbon chlorinated hydrocarbons: Influence of structural and physical properties

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

Umezu, Toyoshi, E-mail: umechan2@nies.go.jp; Shibata, Yasuyuki, E-mail: yshibata@nies.go.jp

2014-09-01

The present study aimed to clarify whether dose–response profiles of acute behavioral effects of 1,2-dichloroethane (DCE), 1,1,1-trichloroethane (TCE), trichloroethylene (TRIC), and tetrachloroethylene (PERC) differ. A test battery involving 6 behavioral endpoints was applied to evaluate the effects of DCE, TCE, TRIC, and PERC in male ICR strain mice under the same experimental conditions. The behavioral effect dose–response profiles of these compounds differed. Regression analysis was used to evaluate the relationship between the dose–response profiles and structural and physical properties of the compounds. Dose–response profile differences correlated significantly with differences in specific structural and physical properties. These results suggest that differencesmore » in specific structural and physical properties of DCE, TCE, TRIC, and PERC are responsible for differences in behavioral effects that lead to a variety of dose–response profiles. - Highlights: • We examine effects of 4 chlorinated hydrocarbons on 6 behavioral endpoints in mice. • The behavioral effect dose–response profiles for the 4 compounds are different. • We utilize regression analysis to clarify probable causes of the different profiles. • The compound's physicochemical properties probably produce the different profiles.« less

Probability workshop to be better in probability topic

NASA Astrophysics Data System (ADS)

Asmat, Aszila; Ujang, Suriyati; Wahid, Sharifah Norhuda Syed

2015-02-01

The purpose of the present study was to examine whether statistics anxiety and attitudes towards probability topic among students in higher education level have an effect on their performance. 62 fourth semester science students were given statistics anxiety questionnaires about their perception towards probability topic. Result indicated that students' performance in probability topic is not related to anxiety level, which means that the higher level in statistics anxiety will not cause lower score in probability topic performance. The study also revealed that motivated students gained from probability workshop ensure that their performance in probability topic shows a positive improvement compared before the workshop. In addition there exists a significance difference in students' performance between genders with better achievement among female students compared to male students. Thus, more initiatives in learning programs with different teaching approaches is needed to provide useful information in improving student learning outcome in higher learning institution.

Effects of multiple levels of social organization on survival and abundance.

PubMed

Ward, Eric J; Semmens, Brice X; Holmes, Elizabeth E; Balcomb Iii, Ken C

2011-04-01

Identifying how social organization shapes individual behavior, survival, and fecundity of animals that live in groups can inform conservation efforts and improve forecasts of population abundance, even when the mechanism responsible for group-level differences is unknown. We constructed a hierarchical Bayesian model to quantify the relative variability in survival rates among different levels of social organization (matrilines and pods) of an endangered population of killer whales (Orcinus orca). Individual killer whales often participate in group activities such as prey sharing and cooperative hunting. The estimated age-specific survival probabilities and survivorship curves differed considerably among pods and to a lesser extent among matrilines (within pods). Across all pods, males had lower life expectancy than females. Differences in survival between pods may be caused by a combination of factors that vary across the population's range, including reduced prey availability, contaminants in prey, and human activity. Our modeling approach could be applied to demographic rates for other species and for parameters other than survival, including reproduction, prey selection, movement, and detection probabilities. Conservation Biology ©2010 Society for Conservation Biology. No claim to original US government works.

The impact of dnaKJ overexpression on recombinant protein solubility results from antagonistic effects on the control of protein quality.

PubMed

Petersson, Lisa; Carrió, M Mar; Vera, Andrea; Villaverde, Antonio

2004-04-01

We have produced increasing levels of DnaK and its co-chaperone DnaJ along with the model VP1LAC misfolding-prone protein, to explore the role of DnaK on the management of Escherichia coli inclusion bodies. While relative solubility of VP1LAC is progressively enhanced, the heat-shock response is down-regulated as revealed by decreasing levels of GroEL. This is accompanied by an increasing yield of VP1LAC and a non-regular evolution of its insoluble fraction, at moderate levels of DnaK resulting in more abundant inclusion bodies. Also, the impact of chaperone co-expression is much more pronounced in wild type cells than in a DnaK- mutant, probably due to the different background of heat shock proteins in these cells. The involvement of DnaK in the supervision of misfolding proteins is then pictured as a dynamic balance between its immediate holding and folding activities, and the side-effect downregulation of the heat shock response though the limitation of other chaperone and proteases activities.

On the Dynamic Nature of Response Criterion in Recognition Memory: Effects of Base Rate, Awareness, and Feedback

ERIC Educational Resources Information Center

Rhodes, Matthew G.; Jacoby, Larry L.

2007-01-01

The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3…

Effects of Multiple Simulation Presentation among Students of Different Anxiety Levels in the Learning of Probability

ERIC Educational Resources Information Center

Fong, Soon Fook; Por, Fei Ping; Tang, Ai Ling

2012-01-01

The purpose of this study was to investigate the effects of multiple simulation presentation in interactive multimedia are on the achievement of students with different levels of anxiety in the learning of Probability. The interactive multimedia courseware was developed in two different modes, which were Multiple Simulation Presentation (MSP) and…

Detecting Intrajudge Inconsistency in Standard Setting Using Test Items with a Selected-Response Format. Research Report.

ERIC Educational Resources Information Center

van der Linden, Wim J.; Vos, Hans J.; Chang, Lei

In judgmental standard setting experiments, it may be difficult to specify subjective probabilities that adequately take the properties of the items into account. As a result, these probabilities are not consistent with each other in the sense that they do not refer to the same borderline level of performance. Methods to check standard setting…

Dissociation between implicit and explicit responses in postconditioning UCS revaluation after fear conditioning in humans

PubMed Central

Schultz, Douglas H.; Balderston, Nicholas L.; Geiger, Jennifer A.; Helmstetter, Fred J.

2014-01-01

The nature of the relationship between explicit and implicit learning is a topic of considerable debate. In order to investigate this relationship we conducted two experiments on postconditioning revaluation of the unconditional stimulus (UCS) in human fear conditioning. In Experiment 1, the intensity of the UCS was decreased following acquisition for one group (devaluation) and held constant for another group (control). A subsequent test revealed that even though both groups exhibited similar levels of UCS expectancy, the devaluation group had significantly smaller conditional skin conductance responses. The devaluation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. In Experiment 2, the value of the UCS was increased following acquisition for one group (inflation) and held constant for another group (control). Test performance revealed that UCS inflation did not alter expectancy ratings, but the inflation group exhibited larger learned skin conductance responses than the control group. The inflation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. The SCR revaluation effect was not dependent on explicit memory processes in either experiment. In both experiments we found differences on an implicit measure of learning in the absence of changes in explicit measures. Together, the differences observed between expectancy measures and skin conductance support the idea that these responses might reflect different types of memory formed during the same training procedure and be supported by separate neural systems. PMID:23731073

The efficacy of inhibiting tumour necrosis factor alpha and interleukin 1 in patients with rheumatoid arthritis: a meta-analysis and adjusted indirect comparisons.

PubMed

Nixon, R; Bansback, N; Brennan, A

2007-07-01

New treatments that inhibit the cytokines tumour necrosis factor alpha (TNFalpha) and interleukin 1 (IL-1) in the treatment of rheumatoid arthritis have proven clinical effect against placebo and methotrexate (MTX) in several clinical trials in early and late-stage disease and different severity groups. Since there are no head-to-head randomized controlled trials directly comparing the currently available treatments, etanercept, adalimumab, infliximab or anakinra, we perform a meta-analysis that adjusts for differences between study characteristics, and allows indirect comparisons between treatments. Thirteen trials of cytokine antagonists were included from a systematic review of the literature. They reported the primary outcome of American College of Rheumatology (ACR) response criteria at 6 months or beyond. Meta-analytical methods are used to quantify relative treatment effects, using the log odds ratio of an ACR20 or ACR50 response at 6 months, whilst adjusting for study-level variables. In each of the trials, cytokine treatment was efficacious in comparison with placebo or MTX. For each treatment, the inclusion of MTX in combination improved the response. After adjustment for study-level variables, we found TNFalpha antagonists to be more efficacious compared with anakinra (P < 0.05). Indirect comparisons between the three TNFalpha antagonists indicated no difference in efficacy. Sensitivity analysis using a different statistical model structure confirmed these results. When the outcome of interest is the probability of an ACR20 or ACR50 response at 6 months we found: (i) treatment with the IL-1 antagonist anakinra is better than placebo; (ii) for each treatment, the use of combination MTX improves the probability of response; (iii) treatment with any of the TNFalpha antagonists is better than with the IL-1 antagonist anakinra; and (iv) all drugs in the TNFalpha antagonist class are no different from each other.

Caffeine and sleep-deprivation mediated changes in open-field behaviours, stress response and antioxidant status in mice.

PubMed

Onaolapo, J Olakunle; Onaolapo, Y Adejoke; Akanmu, A Moses; Olayiwola, Gbola

2016-01-01

Effects of daily caffeine consumption on open-field behaviours, serum corticosterone and brain antioxidant levels were investigated after six hours of total sleep-deprivation in prepubertal mice. We tested the hypothesis that daily caffeine consumption may significantly alter behaviour, stress and antioxidative response of prepubertal mice to an acute episode of total sleep-deprivation. Prepubertal Swiss mice of both sexes were assigned to two main groups of 120 each (subdivided into 6 groups of 10 each, based on sex), and administered vehicle or graded oral doses of caffeine (10, 20, 40, 80 and 120 mg/kg/day) for 14 days. On day 14, a main group was subjected to 6 h of total sleep-deprivation by 'gentle-handling'. Open-field behaviours were then assessed in both groups, after which animals were euthanized, and levels of corticosterone, superoxide dismutase and glutathione peroxidase assayed. Horizontal locomotion, rearing and grooming increased significantly, compared to control, with sleep-deprived (SD) mice showing stronger caffeine-driven responses at higher doses; and SD female mice showing sustained response to caffeine, compared to respective males. Plasma corticosterone increased with increasing doses of caffeine in both non sleep-deprived (NSD) and SD mice; although SD mice had higher corticosterone levels. Sleep-deprivation and/or higher doses of caffeine were associated with derangements in brain antioxidant levels. Repeated caffeine consumption and/or acute sleep-deprivation led to significant changes in pattern of open-field behaviour and stress/antioxidant response in mice. Responses seen in the study are probably due to modulatory effects of caffeine on the total body response to stressful stimuli.

Probabilistic Evaluation of Blade Impact Damage

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Abumeri, G. H.

2003-01-01

The response to high velocity impact of a composite blade is probabilistically evaluated. The evaluation is focused on quantifying probabilistically the effects of uncertainties (scatter) in the variables that describe the impact, the blade make-up (geometry and material), the blade response (displacements, strains, stresses, frequencies), the blade residual strength after impact, and the blade damage tolerance. The results of probabilistic evaluations results are in terms of probability cumulative distribution functions and probabilistic sensitivities. Results show that the blade has relatively low damage tolerance at 0.999 probability of structural failure and substantial at 0.01 probability.

Extinction time of a stochastic predator-prey model by the generalized cell mapping method

NASA Astrophysics Data System (ADS)

Han, Qun; Xu, Wei; Hu, Bing; Huang, Dongmei; Sun, Jian-Qiao

2018-03-01

The stochastic response and extinction time of a predator-prey model with Gaussian white noise excitations are studied by the generalized cell mapping (GCM) method based on the short-time Gaussian approximation (STGA). The methods for stochastic response probability density functions (PDFs) and extinction time statistics are developed. The Taylor expansion is used to deal with non-polynomial nonlinear terms of the model for deriving the moment equations with Gaussian closure, which are needed for the STGA in order to compute the one-step transition probabilities. The work is validated with direct Monte Carlo simulations. We have presented the transient responses showing the evolution from a Gaussian initial distribution to a non-Gaussian steady-state one. The effects of the model parameter and noise intensities on the steady-state PDFs are discussed. It is also found that the effects of noise intensities on the extinction time statistics are opposite to the effects on the limit probability distributions of the survival species.

Geostatistical applications in environmental remediation

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

Stewart, R.N.; Purucker, S.T.; Lyon, B.F.

1995-02-01

Geostatistical analysis refers to a collection of statistical methods for addressing data that vary in space. By incorporating spatial information into the analysis, geostatistics has advantages over traditional statistical analysis for problems with a spatial context. Geostatistics has a history of success in earth science applications, and its popularity is increasing in other areas, including environmental remediation. Due to recent advances in computer technology, geostatistical algorithms can be executed at a speed comparable to many standard statistical software packages. When used responsibly, geostatistics is a systematic and defensible tool can be used in various decision frameworks, such as the Datamore » Quality Objectives (DQO) process. At every point in the site, geostatistics can estimate both the concentration level and the probability or risk of exceeding a given value. Using these probability maps can assist in identifying clean-up zones. Given any decision threshold and an acceptable level of risk, the probability maps identify those areas that are estimated to be above or below the acceptable risk. Those areas that are above the threshold are of the most concern with regard to remediation. In addition to estimating clean-up zones, geostatistics can assist in designing cost-effective secondary sampling schemes. Those areas of the probability map with high levels of estimated uncertainty are areas where more secondary sampling should occur. In addition, geostatistics has the ability to incorporate soft data directly into the analysis. These data include historical records, a highly correlated secondary contaminant, or expert judgment. The role of geostatistics in environmental remediation is a tool that in conjunction with other methods can provide a common forum for building consensus.« less

Behavioral Response of Dolphins to Signals Simulating Mid-Frequency Sonar

DTIC Science & Technology

2011-09-30

following, and for several days to a week following the sound exposure. Blood collections will be analyzed for cortisol and aldosterone and inspected...of corticosteroid hormones (cortisol and aldosterone ) and epinephrine. Levels will be compared between categories and related to exposure level to...distribution of responses by age and experience can probably be expected from wild populations as well. A lack of any physiological indicator of an

GAD vaccine reduces insulin loss in recently diagnosed type 1 diabetes: findings from a Bayesian meta-analysis.

PubMed

Beam, Craig A; MacCallum, Colleen; Herold, Kevan C; Wherrett, Diane K; Palmer, Jerry; Ludvigsson, Johnny

2017-01-01

GAD is a major target of the autoimmune response that occurs in type 1 diabetes mellitus. Randomised controlled clinical trials of a GAD + alum vaccine in human participants have so far given conflicting results. In this study, we sought to see whether a clearer answer to the question of whether GAD65 has an effect on C-peptide could be reached by combining individual-level data from the randomised controlled trials using Bayesian meta-analysis to estimate the probability of a positive biological effect (a reduction in C-peptide loss compared with placebo approximately 1 year after the GAD vaccine). We estimate that there is a 98% probability that 20 μg GAD with alum administered twice yields a positive biological effect. The effect is probably a 15-20% reduction in the loss of C-peptide at approximately 1 year after treatment. This translates to an annual expected loss of between -0.250 and -0.235 pmol/ml in treated patients compared with an expected 2 h AUC loss of -0.294 pmol/ml at 1 year for untreated newly diagnosed patients. The biological effect of this vaccination should be developed further in order to reach clinically desirable reductions in insulin loss in patients recently diagnosed with type 1 diabetes.

Dissociation in decision bias mechanism between probabilistic information and previous decision

PubMed Central

Kaneko, Yoshiyuki; Sakai, Katsuyuki

2015-01-01

Target detection performance is known to be influenced by events in the previous trials. It has not been clear, however, whether this bias effect is due to the previous sensory stimulus, motor response, or decision. Also it remains open whether or not the previous trial effect emerges via the same mechanism as the effect of knowledge about the target probability. In the present study, we asked normal human subjects to make a decision about the presence or absence of a visual target. We presented a pre-cue indicating the target probability before the stimulus, and also a decision-response mapping cue after the stimulus so as to tease apart the effect of decision from that of motor response. We found that the target detection performance was significantly affected by the probability cue in the current trial and also by the decision in the previous trial. While the information about the target probability modulated the decision criteria, the previous decision modulated the sensitivity to target-relevant sensory signals (d-prime). Using functional magnetic resonance imaging (fMRI), we also found that activation in the left intraparietal sulcus (IPS) was decreased when the probability cue indicated a high probability of the target. By contrast, activation in the right inferior frontal gyrus (IFG) was increased when the subjects made a target-present decision in the previous trial, but this change was observed specifically when the target was present in the current trial. Activation in these regions was associated with individual-difference in the decision computation parameters. We argue that the previous decision biases the target detection performance by modulating the processing of target-selective information, and this mechanism is distinct from modulation of decision criteria due to expectation of a target. PMID:25999844

Therapy operating characteristic curves: tools for precision chemotherapy

PubMed Central

Barrett, Harrison H.; Alberts, David S.; Woolfenden, James M.; Caucci, Luca; Hoppin, John W.

2016-01-01

Abstract. The therapy operating characteristic (TOC) curve, developed in the context of radiation therapy, is a plot of the probability of tumor control versus the probability of normal-tissue complications as the overall radiation dose level is varied, e.g., by varying the beam current in external-beam radiotherapy or the total injected activity in radionuclide therapy. This paper shows how TOC can be applied to chemotherapy with the administered drug dosage as the variable. The area under a TOC curve (AUTOC) can be used as a figure of merit for therapeutic efficacy, analogous to the area under an ROC curve (AUROC), which is a figure of merit for diagnostic efficacy. In radiation therapy, AUTOC can be computed for a single patient by using image data along with radiobiological models for tumor response and adverse side effects. The mathematical analogy between response of observers to images and the response of tumors to distributions of a chemotherapy drug is exploited to obtain linear discriminant functions from which AUTOC can be calculated. Methods for using mathematical models of drug delivery and tumor response with imaging data to estimate patient-specific parameters that are needed for calculation of AUTOC are outlined. The implications of this viewpoint for clinical trials are discussed. PMID:27175376

Representation of bidirectional ground motions for design spectra in building codes

USGS Publications Warehouse

Stewart, Jonathan P.; Abrahamson, Norman A.; Atkinson, Gail M.; Beker, Jack W.; Boore, David M.; Bozorgnia, Yousef; Campbell, Kenneth W.; Comartin, Craig D.; Idriss, I.M.; Lew, Marshall; Mehrain, Michael; Moehle, Jack P.; Naeim, Farzad; Sabol, Thomas A.

2011-01-01

The 2009 NEHRP Provisions modified the definition of horizontal ground motion from the geometric mean of spectral accelerations for two components to the peak response of a single lumped mass oscillator regardless of direction. These maximum-direction (MD) ground motions operate under the assumption that the dynamic properties of the structure (e.g., stiffness, strength) are identical in all directions. This assumption may be true for some in-plan symmetric structures, however, the response of most structures is dominated by modes of vibration along specific axes (e.g., longitudinal and transverse axes in a building), and often the dynamic properties (especially stiffness) along those axes are distinct. In order to achieve structural designs consistent with the collapse risk level given in the NEHRP documents, we argue that design spectra should be compatible with expected levels of ground motion along those principal response axes. The use of MD ground motions effectively assumes that the azimuth of maximum ground motion coincides with the directions of principal structural response. Because this is unlikely, design ground motions have lower probability of occurrence than intended, with significant societal costs. We recommend adjustments to make design ground motions compatible with target risk levels.

Taking the easy way out? Increasing implementation effort reduces probability maximizing under cognitive load.

PubMed

Schulze, Christin; Newell, Ben R

2016-07-01

Cognitive load has previously been found to have a positive effect on strategy selection in repeated risky choice. Specifically, whereas inferior probability matching often prevails under single-task conditions, optimal probability maximizing sometimes dominates when a concurrent task competes for cognitive resources. We examined the extent to which this seemingly beneficial effect of increased task demands hinges on the effort required to implement each of the choice strategies. Probability maximizing typically involves a simple repeated response to a single option, whereas probability matching requires choice proportions to be tracked carefully throughout a sequential choice task. Here, we flipped this pattern by introducing a manipulation that made the implementation of maximizing more taxing and, at the same time, allowed decision makers to probability match via a simple repeated response to a single option. The results from two experiments showed that increasing the implementation effort of probability maximizing resulted in decreased adoption rates of this strategy. This was the case both when decision makers simultaneously learned about the outcome probabilities and responded to a dual task (Exp. 1) and when these two aspects were procedurally separated in two distinct stages (Exp. 2). We conclude that the effort involved in implementing a choice strategy is a key factor in shaping repeated choice under uncertainty. Moreover, highlighting the importance of implementation effort casts new light on the sometimes surprising and inconsistent effects of cognitive load that have previously been reported in the literature.

Symptoms of Nutrient Deficiency in Yellow-Poplar Seedlings

Treesearch

Albert F. Ike

1968-01-01

Visual symptoms are described for leaves of yellow-poplar seedlings supplied N, P. and K in varying concentrations ranging from minimal to excessive. Probability of growth responses to added N is high when tissue levels are below 2 percent; no response is likely when they exceed 3 percent.

The Effect of Widowhood on Parent-Child Relationships in Korea: Do Parents' Filial Expectations and Geographic Proximity to Children Matter?

PubMed

Ha, Jung-Hwa; Yoon, Hyunsook; Lim, Yeon Ok; Heo, Sun-Young

2016-03-01

Although previous research based on data from the U.S. suggests that parents' widowhood is associated with increased emotional support from children, little is known about the impact of late-life widowhood on intergenerational relationships in other cultures. Using data of Korean older adults, this paper examined: (1) the effect of widowhood on both positive and negative aspects of parent-child relationships and (2) whether these effects are moderated by older adults' expectations about children's filial responsibilities and the geographic proximity to their children. Analyses are based on data from the Hallym Aging Study, a stratified multi-stage probability sample of older adults living in the cities of Seoul and Chuncheon in Korea. Compared to married older adults, widowed persons in this sample reported higher levels of ambivalence, lower levels of positive interactions, and higher levels of negative interactions with their children. Parents' notion about filial responsibilities did not have a significant moderating effect, whereas geographic proximity to children was a significant moderator. Findings suggest that widowhood is associated with greater strain in intergenerational relationships in Korea. Helping widowed older adults forge constructive relationships with their children may enhance both bereaved older adults' and their children's well-being in this cultural milieu.

Informing disease models with temporal and spatial contact structure among GPS-collared individuals in wild populations.

PubMed

Williams, David M; Dechen Quinn, Amy C; Porter, William F

2014-01-01

Contacts between hosts are essential for transmission of many infectious agents. Understanding how contacts, and thus transmission rates, occur in space and time is critical to effectively responding to disease outbreaks in free-ranging animal populations. Contacts between animals in the wild are often difficult to observe or measure directly. Instead, one must infer contacts from metrics such as proximity in space and time. Our objective was to examine how contacts between white-tailed deer (Odocoileus virginianus) vary in space and among seasons. We used GPS movement data from 71 deer in central New York State to quantify potential direct contacts between deer and indirect overlap in space use across time and space. Daily probabilities of direct contact decreased from winter (0.05-0.14), to low levels post-parturition through summer (0.00-0.02), and increased during the rut to winter levels. The cumulative distribution for the spatial structure of direct and indirect contact probabilities around a hypothetical point of occurrence increased rapidly with distance for deer pairs separated by 1,000 m-7,000 m. Ninety-five percent of the probabilities of direct contact occurred among deer pairs within 8,500 m of one another, and 99% within 10,900 m. Probabilities of indirect contact accumulated across greater spatial extents: 95% at 11,900 m and 99% at 49,000 m. Contacts were spatially consistent across seasons, indicating that although contact rates differ seasonally, they occur proportionally across similar landscape extents. Distributions of contact probabilities across space can inform management decisions for assessing risk and allocating resources in response.

Effect of heat stress on brain 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in some vertebrate species.

PubMed

Mohamed, M I; Rahman, T A

1982-01-01

1. The variations in 5-HT and 5-HIAA levels following heat exposure and split heat doses were determined in the different brain regions of Gerbillus pyramidum, Streptopelia senegalensis aegyptiaca and Agama stellio. 2. Heat exposure was found to be associated with an increase in the levels of the two indole compounds. 3. The 5-HT concentrations increased markedly in the three species following the first heat dose and decreased following the second dose in the various brain regions except in the cerebellum of Agama. 4. The increased 5-HT levels when animals are exposed to high temperature probably represent a response to activate heat-loss mechanisms and to depress heat production.

Behavioral responses of gray whales to industrial noise: feeding observations and predictive modeling

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

Malme, C.I.; Wuersig, B.; Bird, J.E.

1986-08-01

An investigation was made of the potential effects of underwater noise from petroleum-industry activities on feeding gray whales. The investigation consisted of two components, a field study and an acoustic model study. The field study was performed near Southeast Cape, St. Lawrence Island in August, 1985, using a 100 cu. in. air gun source and playback of drillship noise. Sound-source levels and acoustic-propagation losses were measured to permit estimation of sound exposure levels at whale-sighting positions. For the air-gun source there was a 0.5 probability that the whales would stop feeding and move away from the area when the averagemore » pulse levels reached 173 dB.« less

Support vector machine learning-based fMRI data group analysis.

PubMed

Wang, Ze; Childress, Anna R; Wang, Jiongjiong; Detre, John A

2007-07-15

To explore the multivariate nature of fMRI data and to consider the inter-subject brain response discrepancies, a multivariate and brain response model-free method is fundamentally required. Two such methods are presented in this paper by integrating a machine learning algorithm, the support vector machine (SVM), and the random effect model. Without any brain response modeling, SVM was used to extract a whole brain spatial discriminance map (SDM), representing the brain response difference between the contrasted experimental conditions. Population inference was then obtained through the random effect analysis (RFX) or permutation testing (PMU) on the individual subjects' SDMs. Applied to arterial spin labeling (ASL) perfusion fMRI data, SDM RFX yielded lower false-positive rates in the null hypothesis test and higher detection sensitivity for synthetic activations with varying cluster size and activation strengths, compared to the univariate general linear model (GLM)-based RFX. For a sensory-motor ASL fMRI study, both SDM RFX and SDM PMU yielded similar activation patterns to GLM RFX and GLM PMU, respectively, but with higher t values and cluster extensions at the same significance level. Capitalizing on the absence of temporal noise correlation in ASL data, this study also incorporated PMU in the individual-level GLM and SVM analyses accompanied by group-level analysis through RFX or group-level PMU. Providing inferences on the probability of being activated or deactivated at each voxel, these individual-level PMU-based group analysis methods can be used to threshold the analysis results of GLM RFX, SDM RFX or SDM PMU.

Urban sprawl and delayed ambulance arrival in the U.S.

PubMed

Trowbridge, Matthew J; Gurka, Matthew J; O'Connor, Robert E

2009-11-01

Minimizing emergency medical service (EMS) response time is a central objective of prehospital care, yet the potential influence of built environment features such as urban sprawl on EMS system performance is often not considered. This study measures the association between urban sprawl and EMS response time to test the hypothesis that features of sprawling development increase the probability of delayed ambulance arrival. In 2008, EMS response times for 43,424 motor-vehicle crashes were obtained from the Fatal Analysis Reporting System, a national census of crashes involving > or =1 fatality. Sprawl at each crash location was measured using a continuous county-level index previously developed by Ewing et al. The association between sprawl and the probability of a delayed ambulance arrival (> or =8 minutes) was then measured using generalized linear mixed modeling to account for correlation among crashes from the same county. Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival (p=0.03). This probability increases quadratically as the severity of sprawl increases while controlling for nighttime crash occurrence, road conditions, and presence of construction. For example, in sprawling counties (e.g., Fayette County GA), the probability of a delayed ambulance arrival for daytime crashes in dry conditions without construction was 69% (95% CI=66%, 72%) compared with 31% (95% CI=28%, 35%) in counties with prominent smart-growth characteristics (e.g., Delaware County PA). Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival following motor-vehicle crashes in the U.S. The results of this study suggest that promotion of community design and development that follows smart-growth principles and regulates urban sprawl may improve EMS performance and reliability.

Deanol acetamidobenzoate (Deaner) in tardive dyskinesia.

PubMed

Stafford, J R; Fann, W E

1977-12-01

A total of twenty-nine patients have thus far been treated with deanol in various dosage levels for periods ranging from five to thirty days. Clinical response has been pronounced, even dramatic, in seven patients, moderate but significant in nine patients, and slight to insignificant in thirteen others. Videotape rating and quantitative accelerometry, to the extent that they constitute novel and stress-inducing experiences may not be representative of global clinical changes. Deanol did not produce the anticipated elevation in choline levels postulated to be one mechanism of its action. The failure of deanol to achieve this effect may most probably be attributed to interval after last dose, to inadequate level of deanol or to some alteration in choline metabolism in the presence of deanol. The etiology of tardive dyskinesia at biochemical and structural levels is complex. For some patients improvement has been dramatic and clearly associated with deanol. Others appear to exhibit minimal response which cannot be differentiated from placebo or environmental effects. Our present strategy, in common with that of other authors includes the administration of a "challenge" dose of rapid acting injectable cholinomimetic agents (e.g. physostigmine) and dopamine-blocking agents (e.g. haloperidol) with placebo controls. In this manner therapy may be more rationally selected for long-term use and may logically include deanol. The correlation of such predictive challenges with response to long-term treatment is an area for much more well controlled study.

Characterization of a developmental toxicity dose-response model.

PubMed Central

Faustman, E M; Wellington, D G; Smith, W P; Kimmel, C A

1989-01-01

The Rai and Van Ryzin dose-response model proposed for teratology experiments has been characterized for its appropriateness and applicability in modeling the dichotomous response data from developmental toxicity studies. Modifications were made in the initial probability statements to reflect more accurately biological events underlying developmental toxicity. Data sets used for the evaluation were obtained from the National Toxicology Program and U.S. EPA laboratories. The studies included developmental evaluations of ethylene glycol, diethylhexyl phthalate, di- and triethylene glycol dimethyl ethers, and nitrofen in rats, mice, or rabbits. Graphic examination and statistical evaluation demonstrate that this model is sensitive to the data when compared to directly measured experimental outcomes. The model was used to interpolate to low-risk dose levels, and comparisons were made between the values obtained and the no-observed-adverse-effect levels (NOAELs) divided by an uncertainty factor. Our investigation suggests that the Rai and Van Ryzin model is sensitive to the developmental toxicity end points, prenatal deaths, and malformations, and appears to model closely their relationship to dose. PMID:2707204

Research on response spectrum of dam based on scenario earthquake

NASA Astrophysics Data System (ADS)

Zhang, Xiaoliang; Zhang, Yushan

2017-10-01

Taking a large hydropower station as an example, the response spectrum based on scenario earthquake is determined. Firstly, the potential source of greatest contribution to the site is determined on the basis of the results of probabilistic seismic hazard analysis (PSHA). Secondly, the magnitude and epicentral distance of the scenario earthquake are calculated according to the main faults and historical earthquake of the potential seismic source zone. Finally, the response spectrum of scenario earthquake is calculated using the Next Generation Attenuation (NGA) relations. The response spectrum based on scenario earthquake method is less than the probability-consistent response spectrum obtained by PSHA method. The empirical analysis shows that the response spectrum of scenario earthquake considers the probability level and the structural factors, and combines the advantages of the deterministic and probabilistic seismic hazard analysis methods. It is easy for people to accept and provide basis for seismic engineering of hydraulic engineering.

Disease-emergence dynamics and control in a socially-structured wildlife species

NASA Astrophysics Data System (ADS)

Pepin, Kim M.; Vercauteren, Kurt C.

2016-04-01

Once a pathogen is introduced in a population, key factors governing rate of spread include contact structure, supply of susceptible individuals and pathogen life-history. We examined the interplay of these factors on emergence dynamics and efficacy of disease prevention and response. We contrasted transmission dynamics of livestock viruses with different life-histories in hypothetical populations of feral swine with different contact structures (homogenous, metapopulation, spatial and network). Persistence probability was near 0 for the FMDV-like case under a wide range of parameter values and contact structures, while persistence was probable for the CSFV-like case. There were no sets of conditions where the FMDV-like pathogen persisted in every stochastic simulation. Even when population growth rates were up to 300% annually, the FMDV-like pathogen persisted in <25% of simulations regardless of transmission probabilities and contact structure. For networks and spatial contact structure, persistence probability of the FMDV-like pathogen was always <10%. Because of its low persistence probability, even very early response to the FMDV-like pathogen in feral swine was unwarranted while response to the CSFV-like pathogen was generally effective. When pre-emergence culling of feral swine caused population declines, it was effective at decreasing outbreak size of both diseases by ≥80%.

Exploring the role of genetic variability and lifestyle in oxidative stress response for healthy aging and longevity.

PubMed

Dato, Serena; Crocco, Paolina; D'Aquila, Patrizia; de Rango, Francesco; Bellizzi, Dina; Rose, Giuseppina; Passarino, Giuseppe

2013-08-08

Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases. In contrast, centenarians seem to have evolved conservative stress response mechanisms, probably derived from a combination of a diet rich in natural antioxidants, an active lifestyle and a favorable genetic background, particularly rich in genetic variants able to counteract the stress overload at the level of both nuclear and mitochondrial DNA. The integration of these factors could allow centenarians to maintain moderate levels of free radicals that exert beneficial signaling and modulator effects on cellular metabolism. Considering the hot debate on the efficacy of antioxidant supplementation in promoting healthy aging, in this review we gathered the existing information regarding genetic variability and lifestyle factors which potentially modulate the stress response at old age. Evidence reported here suggests that the integration of lifestyle factors (moderate physical activity and healthy nutrition) and genetic background could shift the balance in favor of the antioxidant cellular machinery by activating appropriate defense mechanisms in response to exceeding external and internal stress levels, and thus possibly achieving the prospect of living a longer life.

Measuring Sound-Processor Threshold Levels for Pediatric Cochlear Implant Recipients Using Conditioned Play Audiometry via Telepractice

ERIC Educational Resources Information Center

Goehring, Jenny L.; Hughes, Michelle L.

2017-01-01

Purpose: This study evaluated the use of telepractice for measuring cochlear implant (CI) behavioral threshold (T) levels in children using conditioned play audiometry (CPA). The goals were to determine whether (a) T levels measured via telepractice were not significantly different from those obtained in person, (b) response probability differed…

Relationship between virological response and FIB-4 index in chronic hepatitis B patients with entecavir therapy

PubMed Central

Li, Ni; Xu, Jing-Hang; Yu, Min; Wang, Sa; Si, Chong-Wen; Yu, Yan-Yan

2015-01-01

AIM: To investigate whether long-term low-level hepatitis B virus (HBV) DNA influences dynamic changes of the FIB-4 index in chronic hepatitis B (CHB) patients receiving entecavir (ETV) therapy with partial virological responses. METHODS: We retrospectively analyzed 231 nucleos(t)ide (NA) naïve CHB patients from our previous study (NCT01926288) who received continuous ETV or ETV maleate therapy for three years. The patients were divided into partial virological response (PVR) and complete virological response (CVR) groups according to serum HBV DNA levels at week 48. Seventy-six patients underwent biopsies at baseline and at 48 wk. The performance of the FIB-4 index and area under the receiver operating characteristic (AUROC) curve for predicting fibrosis were determined for the patients undergoing biopsy. The primary objective of the study was to compare the cumulative probabilities of virological responses between the two groups during the treatment period. The secondary outcome was to observe dynamic changes of the FIB-4 index between CVR patients and PVR patients. RESULTS: For hepatitis B e antigen (HBeAg)-positive patients (n = 178), the cumulative probability of achieving undetectable levels at week 144 was 95% and 69% for CVR and PVR patients, respectively (P < 0.001). In the Cox proportional hazards model, a lower pretreatment serum HBV DNA level was an independent factor predicting maintained viral suppression. The cumulative probability of achieving undetectable levels of HBV DNA for HBeAg-negative patients (n = 53) did not differ between the two groups. The FIB-4 index efficiently identified fibrosis, with an AUROC of 0.80 (95%CI: 0.69-0.89). For HBeAg-positive patients, the FIB-4 index was higher in CVR patients than in PVR patients at baseline (1.89 ± 1.43 vs 1.18 ± 0.69, P < 0.001). There was no significant difference in the reduction of the FIB-4 index between the CVR and PVR groups from weeks 48 to 144 (-0.11 ± 0.47 vs -0.13 ± 0.49, P = 0.71). At week 144, the FIB-4 index levels were similar between the two groups (1.24 ± 0.87 vs 1.02 ± 0.73, P = 0.06). After multivariate logistic regression analysis, a lower baseline serum HBV DNA level was associated with improvement of liver fibrosis. In HBeAg-negative patients, the FIB-4 index did not differ between the two groups. CONCLUSION: The cumulative probabilities of HBV DNA responses showed significant differences between CVR and PVR HBeAg-positive CHB patients undergoing entecavir treatment for 144 wk. However, long-term low-level HBV DNA did not deteriorate the FIB-4 index, which was used to evaluate liver fibrosis, at the end of three years. PMID:26604649

Expectations for antibiotics increase their prescribing: Causal evidence about localized impact.

PubMed

Sirota, Miroslav; Round, Thomas; Samaranayaka, Shyamalee; Kostopoulou, Olga

2017-04-01

Clinically irrelevant but psychologically important factors such as patients' expectations for antibiotics encourage overprescribing. We aimed to (a) provide missing causal evidence of this effect, (b) identify whether the expectations distort the perceived probability of a bacterial infection either in a pre- or postdecisional distortions pathway, and (c) detect possible moderators of this effect. Family physicians expressed their willingness to prescribe antibiotics (Experiment 1, n₁ = 305) or their decision to prescribe (Experiment 2, n₂ = 131) and assessed the probability of a bacterial infection in hypothetical patients with infections either with low or high expectations for antibiotics. Response order of prescribing/probability was manipulated in Experiment 1. Overall, the expectations for antibiotics increased intention to prescribe (Experiment 1, F(1, 301) = 25.32, p < .001, η p ² = .08, regardless of the response order; Experiment 2, odds ratio [OR] = 2.31, and OR = 0.75, Vignettes 1 and 2, respectively). Expectations for antibiotics did not change the perceived probability of a bacterial infection (Experiment 1, F(1, 301) = 1.86, p = .173, η p ² = .01, regardless of the response order; Experiment 2, d = -0.03, and d = +0.25, Vignettes 1 and 2, respectively). Physicians' experience was positively associated with prescribing, but it did not moderate the expectations effect on prescribing. Patients' and their parents' expectations increase antibiotics prescribing, but their effect is localized-it does not leak into the perceived probability of a bacterial infection. Interventions reducing the overprescribing of antibiotics should target also psychological factors. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cognitive processes as mediators of the relation between mindfulness and change in social anxiety symptoms following cognitive behavioral treatment

PubMed Central

Morgan, Jessica R.; Price, Matthew; Schmertz, Stefan K.; Johnson, Suzanne B.; Masuda, Akihiko; Calamaras, Martha; Anderson, Page L.

2014-01-01

The present study examined whether pretreatment mindfulness exerts an indirect effect on outcomes following cognitive-behavioral therapy (CBT). Cognitive processes of probability and cost bias (i.e., overestimations of the likelihood that negative social events will occur, and that these events will have negative consequences when they do occur) were explored as potential mediators of the relation between mindfulness and social anxiety symptom change. People with higher levels of mindfulness may be better able to benefit from treatments that reduce biases because mindfulness may aid in regulation of attention. Sixty-seven individuals with a primary diagnosis of social phobia identifying public speaking as their greatest fear received eight sessions of one of two types of exposure-based CBT delivered according to treatment manuals. Participants completed self-report measures of mindfulness, probability bias, cost bias, and social anxiety symptoms. Mediation hypotheses were assessed by a bootstrapped regression using treatment outcome data. Pretreatment mindfulness was not related to change in social anxiety symptoms from pre- to posttreatment. However, mindfulness had an indirect effect on treatment outcome via its association with probability bias, but not cost bias, at midtreatment. These findings were consistent across three metrics of social anxiety symptoms. Mindfulness may play a role in response to CBT among individuals with social phobia through its relation with probability bias – even when the treatment does not target mindfulness. PMID:24147809

Heightened fire probability in Indonesia in non-drought conditions: the effect of increasing temperatures

NASA Astrophysics Data System (ADS)

Fernandes, Kátia; Verchot, Louis; Baethgen, Walter; Gutierrez-Velez, Victor; Pinedo-Vasquez, Miguel; Martius, Christopher

2017-05-01

In Indonesia, drought driven fires occur typically during the warm phase of the El Niño Southern Oscillation. This was the case of the events of 1997 and 2015 that resulted in months-long hazardous atmospheric pollution levels in Equatorial Asia and record greenhouse gas emissions. Nonetheless, anomalously active fire seasons have also been observed in non-drought years. In this work, we investigated the impact of temperature on fires and found that when the July-October (JASO) period is anomalously dry, the sensitivity of fires to temperature is modest. In contrast, under normal-to-wet conditions, fire probability increases sharply when JASO is anomalously warm. This describes a regime in which an active fire season is not limited to drought years. Greater susceptibility to fires in response to a warmer environment finds support in the high evapotranspiration rates observed in normal-to-wet and warm conditions in Indonesia. We also find that fire probability in wet JASOs would be considerably less sensitive to temperature were not for the added effect of recent positive trends. Near-term regional climate projections reveal that, despite negligible changes in precipitation, a continuing warming trend will heighten fire probability over the next few decades especially in non-drought years. Mild fire seasons currently observed in association with wet conditions and cool temperatures will become rare events in Indonesia.

Is an immune reaction required for malignant transformation and cancer growth?

PubMed

Prehn, Richmond T; Prehn, Liisa M

2012-07-01

Increasing evidence has shown that probably all malignant mouse cells, even those of spontaneous sporadic cancers, are endowed with tumor-specific antigens. Stimulation of cancer growth, rather than inhibition by the immune reaction, is seemingly the prevalent effect in the animal of origin (the autochthonous animal). Small initial dosages of even strong tumor antigens tend to produce stimulatory immune reactions rather than tumor inhibition in any animal. Thus, an immune response at a low level may be an essential growth-driving feature of nascent cancers, and this may be why all cancers apparently have tumor-specific antigens. Inasmuch as a low level of immunity is stimulatory to tumor growth while larger dosages are inhibitory, immuno-selection via this low response may tend to keep the antitumor immune reaction weak and at a nearly maximal stimulatory level throughout most of a tumor's existence. These facts suggest that both suppression of tumor immunity and a heightened immune reaction might each be therapeutic although very contrasting modalities.

Recent ecological responses to climate change support predictions of high extinction risk

PubMed Central

Maclean, Ilya M. D.; Wilson, Robert J.

2011-01-01

Predicted effects of climate change include high extinction risk for many species, but confidence in these predictions is undermined by a perceived lack of empirical support. Many studies have now documented ecological responses to recent climate change, providing the opportunity to test whether the magnitude and nature of recent responses match predictions. Here, we perform a global and multitaxon metaanalysis to show that empirical evidence for the realized effects of climate change supports predictions of future extinction risk. We use International Union for Conservation of Nature (IUCN) Red List criteria as a common scale to estimate extinction risks from a wide range of climate impacts, ecological responses, and methods of analysis, and we compare predictions with observations. Mean extinction probability across studies making predictions of the future effects of climate change was 7% by 2100 compared with 15% based on observed responses. After taking account of possible bias in the type of climate change impact analyzed and the parts of the world and taxa studied, there was less discrepancy between the two approaches: predictions suggested a mean extinction probability of 10% across taxa and regions, whereas empirical evidence gave a mean probability of 14%. As well as mean overall extinction probability, observations also supported predictions in terms of variability in extinction risk and the relative risk associated with broad taxonomic groups and geographic regions. These results suggest that predictions are robust to methodological assumptions and provide strong empirical support for the assertion that anthropogenic climate change is now a major threat to global biodiversity. PMID:21746924

Recent ecological responses to climate change support predictions of high extinction risk.

PubMed

Maclean, Ilya M D; Wilson, Robert J

2011-07-26

Predicted effects of climate change include high extinction risk for many species, but confidence in these predictions is undermined by a perceived lack of empirical support. Many studies have now documented ecological responses to recent climate change, providing the opportunity to test whether the magnitude and nature of recent responses match predictions. Here, we perform a global and multitaxon metaanalysis to show that empirical evidence for the realized effects of climate change supports predictions of future extinction risk. We use International Union for Conservation of Nature (IUCN) Red List criteria as a common scale to estimate extinction risks from a wide range of climate impacts, ecological responses, and methods of analysis, and we compare predictions with observations. Mean extinction probability across studies making predictions of the future effects of climate change was 7% by 2100 compared with 15% based on observed responses. After taking account of possible bias in the type of climate change impact analyzed and the parts of the world and taxa studied, there was less discrepancy between the two approaches: predictions suggested a mean extinction probability of 10% across taxa and regions, whereas empirical evidence gave a mean probability of 14%. As well as mean overall extinction probability, observations also supported predictions in terms of variability in extinction risk and the relative risk associated with broad taxonomic groups and geographic regions. These results suggest that predictions are robust to methodological assumptions and provide strong empirical support for the assertion that anthropogenic climate change is now a major threat to global biodiversity.

Event-related potentials dissociate facilitation and interference effects in the numerical Stroop paradigm.

PubMed

Szucs, Dénes; Soltész, Fruzsina

2007-11-05

In the numerical Stroop paradigm (NSP) participants compare simultaneously presented Arabic digits based on either their numerical or on their physical size dimension. Responses are faster when the numerical and size dimensions are congruent with each other (facilitation), and responses are slower when the numerical and size dimensions are incongruent with each other (interference). We aimed to find out whether facilitation and interference appears during the course of perceptual or response processing. To this end, facilitation and interference effects in the amplitude of event-related brain potentials (ERPs) were examined. The onset of motor preparation was determined by monitoring the lateralized readiness potential. In numerical comparison one facilitation effect was related to perceptual processing at the level of the magnitude representation. A second facilitation effect and interference effects appeared during response processing. In size comparison facilitation and interference appeared exclusively during response processing. In both tasks, ERP interference effects were probably related to contextual analysis and to the conflict monitoring and selection for action activity of the anterior cingulate cortex. The results demonstrate that facilitation and interference effects in the NSP appear during multiple stages of processing, and that they are related to different cognitive processes. Therefore these effects should be clearly separated in studies of the NSP. A model of the processes involved in the NSP is provided and implications for studies of the NSP are drawn.

On the dynamic nature of response criterion in recognition memory: effects of base rate, awareness, and feedback.

PubMed

Rhodes, Matthew G; Jacoby, Larry L

2007-03-01

The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3 experiments indicated that participants' response criteria were sensitive to the probability that an item was previously studied and that shifts in criterion were robust. In addition, awareness of the bases for criterion shifts and feedback on performance were key factors contributing to the observed shifts in decision criteria. These data suggest that decision processes can operate in a dynamic fashion, shifting from item to item.

Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites

NASA Technical Reports Server (NTRS)

Kopp, Robert E.; Horton, Radley M.; Little, Christopher M.; Mitrovica, Jerry X.; Oppenheimer, Michael; Rasmussen, D. J.; Strauss, Benjamin H.; Tebaldi, Claudia

2014-01-01

Sea-level rise due to both climate change and non-climatic factors threatens coastal settlements, infrastructure, and ecosystems. Projections of mean global sea-level (GSL) rise provide insufficient information to plan adaptive responses; local decisions require local projections that accommodate different risk tolerances and time frames and that can be linked to storm surge projections. Here we present a global set of local sea-level (LSL) projections to inform decisions on timescales ranging from the coming decades through the 22nd century. We provide complete probability distributions, informed by a combination of expert community assessment, expert elicitation, and process modeling. Between the years 2000 and 2100, we project a very likely (90% probability) GSL rise of 0.5–1.2?m under representative concentration pathway (RCP) 8.5, 0.4–0.9?m under RCP 4.5, and 0.3–0.8?m under RCP 2.6. Site-to-site differences in LSL projections are due to varying non-climatic background uplift or subsidence, oceanographic effects, and spatially variable responses of the geoid and the lithosphere to shrinking land ice. The Antarctic ice sheet (AIS) constitutes a growing share of variance in GSL and LSL projections. In the global average and at many locations, it is the dominant source of variance in late 21st century projections, though at some sites oceanographic processes contribute the largest share throughout the century. LSL rise dramatically reshapes flood risk, greatly increasing the expected number of “1-in-10” and “1-in-100” year events.

Probabilistic 21st and 22nd century sea-level projections at a global network of tide-gauge sites

NASA Astrophysics Data System (ADS)

Kopp, Robert E.; Horton, Radley M.; Little, Christopher M.; Mitrovica, Jerry X.; Oppenheimer, Michael; Rasmussen, D. J.; Strauss, Benjamin H.; Tebaldi, Claudia

2014-08-01

Sea-level rise due to both climate change and non-climatic factors threatens coastal settlements, infrastructure, and ecosystems. Projections of mean global sea-level (GSL) rise provide insufficient information to plan adaptive responses; local decisions require local projections that accommodate different risk tolerances and time frames and that can be linked to storm surge projections. Here we present a global set of local sea-level (LSL) projections to inform decisions on timescales ranging from the coming decades through the 22nd century. We provide complete probability distributions, informed by a combination of expert community assessment, expert elicitation, and process modeling. Between the years 2000 and 2100, we project a very likely (90% probability) GSL rise of 0.5-1.2 m under representative concentration pathway (RCP) 8.5, 0.4-0.9 m under RCP 4.5, and 0.3-0.8 m under RCP 2.6. Site-to-site differences in LSL projections are due to varying non-climatic background uplift or subsidence, oceanographic effects, and spatially variable responses of the geoid and the lithosphere to shrinking land ice. The Antarctic ice sheet (AIS) constitutes a growing share of variance in GSL and LSL projections. In the global average and at many locations, it is the dominant source of variance in late 21st century projections, though at some sites oceanographic processes contribute the largest share throughout the century. LSL rise dramatically reshapes flood risk, greatly increasing the expected number of "1-in-10" and "1-in-100" year events.

The effect of low dose rate on metabolomic response to radiation in mice

PubMed Central

Goudarzi, Maryam; Mak, Tytus D.; Chen, Congju; Smilenov, Lubomir B.; Brenner, David J.

2014-01-01

Metabolomics has been shown to have utility in assessing responses to exposure by ionizing radiation (IR) in easily accessible biofluids such as urine. Most studies to date from our laboratory and others have employed γ-irradiation at relatively high dose rates (HDR), but many environmental exposure scenarios will probably be at relatively low dose rates (LDR). There are well-documented differences in the biologic responses to LDR compared to HDR, so an important question is to assess LDR effects at the metabolomics level. Our study took advantage of a modern mass spectrometry approach in exploring the effects of dose rate on the urinary excretion levels of metabolites 2 days after IR in mice. A wide variety of statistical tools were employed to further focus on metabolites, which showed responses to LDR IR exposure (0.00309 Gy/min) distinguishable from those of HDR. From a total of 709 detected spectral features, more than 100 were determined to be statistically significant when comparing urine from mice irradiated with 1.1 or 4.45 Gy to that of sham-irradiated mice 2 days post-exposure. The results of this study show that LDR and HDR exposures perturb many of the same pathways such as TCA cycle and fatty acid metabolism, which also have been implicated in our previous IR studies. However, it is important to note that dose rate did affect the levels of particular metabolites. Differences in urinary excretion levels of such metabolites could potentially be used to assess an individual's exposure in a radiobiological event and thus would have utility for both triage and injury assessment. PMID:25047638

Poisson statistics of PageRank probabilities of Twitter and Wikipedia networks

NASA Astrophysics Data System (ADS)

Frahm, Klaus M.; Shepelyansky, Dima L.

2014-04-01

We use the methods of quantum chaos and Random Matrix Theory for analysis of statistical fluctuations of PageRank probabilities in directed networks. In this approach the effective energy levels are given by a logarithm of PageRank probability at a given node. After the standard energy level unfolding procedure we establish that the nearest spacing distribution of PageRank probabilities is described by the Poisson law typical for integrable quantum systems. Our studies are done for the Twitter network and three networks of Wikipedia editions in English, French and German. We argue that due to absence of level repulsion the PageRank order of nearby nodes can be easily interchanged. The obtained Poisson law implies that the nearby PageRank probabilities fluctuate as random independent variables.

p-adic stochastic hidden variable model

NASA Astrophysics Data System (ADS)

Khrennikov, Andrew

1998-03-01

We propose stochastic hidden variables model in which hidden variables have a p-adic probability distribution ρ(λ) and at the same time conditional probabilistic distributions P(U,λ), U=A,A',B,B', are ordinary probabilities defined on the basis of the Kolmogorov measure-theoretical axiomatics. A frequency definition of p-adic probability is quite similar to the ordinary frequency definition of probability. p-adic frequency probability is defined as the limit of relative frequencies νn but in the p-adic metric. We study a model with p-adic stochastics on the level of the hidden variables description. But, of course, responses of macroapparatuses have to be described by ordinary stochastics. Thus our model describes a mixture of p-adic stochastics of the microworld and ordinary stochastics of macroapparatuses. In this model probabilities for physical observables are the ordinary probabilities. At the same time Bell's inequality is violated.

Multiple effects of sentential constraint on word processing

PubMed Central

Federmeier, Kara D.; Wlotko, Edward W.; De Ochoa-Dewald, Esmeralda; Kutas, Marta

2009-01-01

Behavioral and electrophysiological studies have uncovered different patterns of constraint effects on the processing of words in sentences. Whereas response time measures have indicated a reduced scope of facilitation from strongly constraining contexts, event-related brain potential (ERP) measures have instead revealed enhanced facilitation for semantically related endings in such sentences. Given this disparity, and the concomitant possibility of functionally separable stages of context effects, the current study jointly examined expectancy (cloze probability) and constraint effects on the ERP response to words. Expected and unexpected (but plausible) words completed strongly and weakly constraining sentences; unexpected items were matched for contextual fit across the two levels of constraint and were semantically unrelated to the most expected endings. N400 amplitudes were graded by expectancy but unaffected by constraint and seemed to index the benefit of contextual information. However, a later effect, in the form of increased frontal positivity from 500 to 900 ms post-stimulus-onset, indicated a possible cost associated with the processing of unexpected words in strongly constraining contexts. PMID:16901469

Riboflavin and migraine: the bridge over troubled mitochondria.

PubMed

Colombo, Bruno; Saraceno, Lorenzo; Comi, Giancarlo

2014-05-01

Brain energy metabolism has been found to be disturbed in migraine. A mitochondrial defect may reduce the threshold for migraine attacks both increasing neuronal excitability and leading migrainous brain to a hyper-responsiveness to triggering stimuli. Riboflavin, a major co-factor in oxidative metabolism, may overcome this impairment. RCT studies in adult confirmed that riboflavin is safe and probably effective in migraine prophylaxis, based on level B evidence. Improving brain energy metabolism may reduce the susceptibility to migraine when brain energy demand increases due to both physiological and biopsychological factors.

Effects of Dietary Zinc Manipulation on Growth Performance, Zinc Status and Immune Response during Giardia lamblia Infection: A Study in CD-1 Mice

PubMed Central

Iñigo-Figueroa, Gemma; Méndez-Estrada, Rosa O.; Quihui-Cota, Luis; Velásquez-Contreras, Carlos A.; Garibay-Escobar, Adriana; Canett-Romero, Rafael; Astiazarán-García, Humberto

2013-01-01

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 106 G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host’s humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection. PMID:24002196

Single electrode micro-stimulation of rat auditory cortex: an evaluation of behavioral performance.

PubMed

Rousche, Patrick J; Otto, Kevin J; Reilly, Mark P; Kipke, Daryl R

2003-05-01

A combination of electrophysiological mapping, behavioral analysis and cortical micro-stimulation was used to explore the interrelation between the auditory cortex and behavior in the adult rat. Auditory discriminations were evaluated in eight rats trained to discriminate the presence or absence of a 75 dB pure tone stimulus. A probe trial technique was used to obtain intensity generalization gradients that described response probabilities to mid-level tones between 0 and 75 dB. The same rats were then chronically implanted in the auditory cortex with a 16 or 32 channel tungsten microwire electrode array. Implanted animals were then trained to discriminate the presence of single electrode micro-stimulation of magnitude 90 microA (22.5 nC/phase). Intensity generalization gradients were created to obtain the response probabilities to mid-level current magnitudes ranging from 0 to 90 microA on 36 different electrodes in six of the eight rats. The 50% point (the current level resulting in 50% detections) varied from 16.7 to 69.2 microA, with an overall mean of 42.4 (+/-8.1) microA across all single electrodes. Cortical micro-stimulation induced sensory-evoked behavior with similar characteristics as normal auditory stimuli. The results highlight the importance of the auditory cortex in a discrimination task and suggest that micro-stimulation of the auditory cortex might be an effective means for a graded information transfer of auditory information directly to the brain as part of a cortical auditory prosthesis.

Salt stress induced lipid accumulation in heterotrophic culture cells of Chlorella protothecoides: Mechanisms based on the multi-level analysis of oxidative response, key enzyme activity and biochemical alteration.

PubMed

Wang, Tao; Ge, Haiyan; Liu, Tingting; Tian, Xiwei; Wang, Zejian; Guo, Meijin; Chu, Ju; Zhuang, Yingping

2016-06-20

Salt stress as an effective stress factor that could improve the lipid content and lipid yield of glucose in the heterotrophic culture cells of Chlorella protothecoides was demonstrated in this study. The highest lipid content of 41.2% and lipid yield of 185.8mg/g were obtained when C. protothecoides was stressed under 30g/L NaCl condition at its late logarithmic growth phase. Moreover, the effects of salt and osmotic stress on lipid accumulation were comparatively analyzed, and it was found that the effects of NaCl and KCl stress had no significant differences at the same osmolarity level of 1150mOsm/kg with lipid contents of 41.7 and 40.8% as well as lipid yields of 192.9 and 186.8mg/g, respectively, whereas these results were obviously higher than those obtained under the iso-osmotic glycerol and sorbitol stresses. Furthermore, basing on the multi-level analysis of oxidative response, key enzyme activity and biochemical alteration, the superior performance of salt stress driving lipid over-synthesis was probably ascribed to the more ROS production as a result of additional ion effect besides the osmotic effect, subsequently mediating the alteration from carbohydrate storage to lipid accumulation in signal transduction process of C. protothecoides. Copyright © 2016. Published by Elsevier B.V.

Comparison of the Effects of Iodine and Iodide on Thyroid Function in Humans

NASA Technical Reports Server (NTRS)

Robison, Linda M.; Bull, Richard J.; Sylvester, Paul W.; Birkenfeld, Paul; Lang, Jerome

1995-01-01

The present experiment in humans failed to confirm the differential effect of I(sub 2) on maintenance of serum T(sub 4) concentrations relative to the effects of I(-) that was observed in prior experiments in rats. The reaction of I(sub 2) with metabolites of thyroid hormones in the intestine that appears responsible for this effect in rats probably also exists at some level in humans. The present results suggest that the concentrations of such metabolites in the human intestinal tract are too small to significantly affect circulating concentration of T(sub 4). However, based on the elevations in TSH, there should be some concern over the potential impacts of chronic consumption of iodine in drinking water.

Immunomodulation of Tumor Growth

PubMed Central

Prehn, Richmond T.

1974-01-01

Most and perhaps all neoplasms arouse an immune response in their hosts. Unfortunately, this response is seldom effective in limiting tumor growth. Immunologic surveillance, as originally conceived, probably does not exist. The early weak response to nascent tumors stimulates rather than inhibits their growth. A truly tumor-limiting reaction occurs only in exceptional tumor systems, and then it is relatively late and ineffectual. Immunity may be of great importance in limiting the activity of oncogenic viruses, but is probably seldom the determiner of whether or not an already transformed cell gives rise to a lethal cancer. PMID:4548632

Introduction of an Emergency Response Plan for flood loading of Sultan Abu Bakar Dam in Malaysia

NASA Astrophysics Data System (ADS)

Said, N. F. Md; Sidek, L. M.; Basri, H.; Muda, R. S.; Razad, A. Z. Abdul

2016-03-01

Sultan Abu Bakar Dam Emergency Response Plan (ERP) is designed to assist employees for identifying, monitoring, responding and mitigation dam safety emergencies. This paper is outlined to identification of an organization chart, responsibility for emergency management team and triggering level in Sultan Abu Bakar Dam ERP. ERP is a plan that guides responsibilities for proper operation of Sultan Abu Bakar Dam in respond to emergency incidents affecting the dam. Based on this study four major responsibilities are needed for Abu Bakar Dam owing to protect any probable risk for downstream which they can be Incident Commander, Deputy Incident Commander, On-Scene Commander, Civil Engineer. In conclusion, having organization charts based on ERP studies can be helpful for decreasing the probable risks in any projects such as Abu Bakar Dam and it is a way to identify and suspected and actual dam safety emergencies.

Short term memory may be the depletion of the readily releasable pool of presynaptic neurotransmitter vesicles of a metastable long term memory trace pattern.

PubMed

Tarnow, Eugen

2009-09-01

The Tagging/Retagging model of short term memory was introduced earlier (Tarnow in Cogn Neurodyn 2(4):347-353, 2008) to explain the linear relationship between response time and correct response probability for word recall and recognition: At the initial stimulus presentation the words displayed tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 s and to 20% after 220 s. If a probe word is reintroduced the tagging level has to return to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss. The tagging level is directly related to the probability of correct word recall and recognition. Evidence presented suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis). The pattern of depleted presynaptic terminals corresponds to the long term memory trace.

Modeling and simulation of sexual activity daily diary data of patients with female sexual arousal disorder treated with sildenafil citrate (Viagra).

PubMed

Claret, Laurent; Cox, Eugene H; McFadyen, Lynn; Pidgen, Alwyn; Johnson, Patrick J; Haughie, Scott; Boolell, Mitra; Bruno, Rene

2006-08-01

To develop a model to explore the dose-response of sildenafil citrate in patients with female sexual arousal disorder (FSAD) based on telephone sexual activity daily diary (TSADD) data obtained in double-blind, placebo controlled clinical studies. Data were available on 614 patients with FSAD. A parametric model (Weibull distribution) was developed to describe the probability density function of the time between sexual events. Orgasm satisfaction scores and overall sexual satisfaction scores were simultaneously modeled as ordered categorical variables. Simulations were performed to evaluate the expected clinical response in patients with FSAD. The expected time between sexual events was approximately 3.5 days. Satisfaction scores increased with time to achieve a plateau after 3 to 4 weeks on treatment. The expected probability of satisfying orgasm (score of 3 and higher) ranged from 34.7% for placebo to 41.6% for 100 mg sildenafil citrate. Treatment effect (difference from placebo) was 6.9% for 100 mg sildenafil citrate, ranging from 0.6 to 24.7% for testosterone levels of 0.1 to 4.0 pg/ml. The treatment effect in postmenopausal women was larger than in premenopausal women. A modeling and simulation framework to support drug development in FSAD was developed. Sildenafil citrate demonstrated a dose-dependent effect in patients with FSAD.

[Analysis of main risk factors causing foodborne diseases in food catering business].

PubMed

Fan, Yong-xiang; Liu, Xiu-mei; Bao, Yi-dan

2011-06-01

To study main risk factors that cause foodborne diseases in food catering business. Data from references and investigations conducted in food catering units were used to establish models which based on @Risk 4.5 with Monte Carlo method referring to food handling practice model (FHPM) to make risk assessment on factors of food contamination in food catering units. The Beta-Poisson models on dose-response relationship to Salmonella (developed by WHO/FAO and United States Department of Agriculture) and Vibrio parahaemolyticus (developed by US FDA) were used in this article to analyze the dose-response relationship of pathogens. The average probability of food poisoning by consuming Salmonella contaminated cooked meat under refrigeration was 1.96 × 10(-4) which was 1/2800 of the food under non-refrigeration (the average probability of food poisoning was 0.35 at room temperature 25°C). The average probability by consuming 6 hours stored meat under room temperature was 0.11 which was 16 times of 2 hours storage (6.79 × 10(-3)). The average probability by consuming contaminated meat without fully cooking was 1.71 × 10(-4) which was 100 times of consuming fully cooked meat (1.88 × 10(-6)). The probability growth of food poisoning by consuming Vibrio parahaemolyticus contaminated fresh seafood was proportional with contamination level and prevalence. The primary contamination level, storage temperature and time, cooking process and cross contamination are important factors of catering food safety.

Vulnerability, safety and response of nuclear power plants to the hydroclimatic hazards

NASA Astrophysics Data System (ADS)

János Katona, Tamás; Vilimi, András

2016-04-01

The Great Tohoku Earthquake and Tsunami, and the severe accident at Fukushima Dai-ichi nuclear power plant 2011 alerted the nuclear industry to danger of extreme rare natural hazards. The subsequent "stress tests" performed by the nuclear industry in Europe and all over the world identifies the nuclear power plant (NPP) vulnerabilities and define the measures for increasing the plant safety. According to the international practice of nuclear safety regulations, the cumulative core damage frequency for NPPs has to be 10-5/a, and the cumulative frequency of early large release has to be 10-6/a. In case of operating plants these annual probabilities can be little higher, but the licensees are obliged to implement all reasonable practicable measures for increasing the plant safety. For achieving the required level of safety, design basis of NPPs for natural hazards has to be defined at the 10-4/a ⎯10-5/a levels of annual exceedance probability. Tornado hazard is some kind of exception, e.g., the design basis annual probability for tornado in the US is equal to 10-7/a. Design of the NPPs shall provide for an adequate margin to protect items ultimately necessary to prevent large or early radioactive releases in the event of levels of natural hazards exceeding those to be considered for design. The plant safety has to be reviewed for accounting the changes of the environmental conditions and natural hazards in case of necessity, but as minimum every ten years in the frame of periodic safety reviews. Long-term forecast of environmental conditions and hazards has to be accounted for in the design basis of the new plants. Changes in hydroclimatic variables, e.g., storms, tornadoes, river floods, flash floods, extreme temperatures, droughts affect the operability and efficiency as well as the safety the NPPs. Low flow rates and high water temperature in the rivers may force to operate at reduced power level or shutdown the plant (Cernavoda NPP, Romania, August 2009). The practice demonstrated that the NPPs could safely withstand the meteorological extremes (Katrina hurricane, 2005). However the floods at some sites cause significant safety issues. Design of NPPs and their response to extreme hydroclimatic events depends on the features of particular hazards, e.g., predictability, possibility and time available for the protective actions, potential for causing cliff-edge effects and the possible combinations of events. The uncertainty of the prediction of extreme values for the design and safety assessment is a fundamental issue. In the paper the consequences of hydroclimatic extremes are analysed for nuclear power plants. The possibility of operational response to extremes is presented. The safety margins are assessed with respect to the effects caused by hydroclimatic extremes. The direct actions (e.g. wind) and the indirect consequences (e.g. changing of ground water level) are also considered. Methods for accounting the uncertainties of the characterisation of low probability hazards are also considered. The preparedness to severe hydroclimatic conditions / events and actions for mitigation and management are presented and discussed. The considerations in the paper are illustrated by the case of the Paks Nuclear Power Plant, Hungary.

Predicting Effects of Water Regime Changes on Waterbirds: Insights from Staging Swans

PubMed Central

Nolet, Bart A.; Gyimesi, Abel; van Krimpen, Roderick R. D.; de Boer, Willem F.; Stillman, Richard A.

2016-01-01

Predicting the environmental impact of a proposed development is notoriously difficult, especially when future conditions fall outside the current range of conditions. Individual-based approaches have been developed and applied to predict the impact of environmental changes on wintering and staging coastal bird populations. How many birds make use of staging sites is mostly determined by food availability and accessibility, which in the case of many waterbirds in turn is affected by water level. Many water systems are regulated and water levels are maintained at target levels, set by management authorities. We used an individual-based modelling framework (MORPH) to analyse how different target water levels affect the number of migratory Bewick’s swans Cygnus columbianus bewickii staging at a shallow freshwater lake (Lauwersmeer, the Netherlands) in autumn. As an emerging property of the model, we found strong non-linear responses of swan usage to changes in water level, with a sudden drop in peak numbers as well as bird-days with a 0.20 m rise above the current target water level. Such strong non-linear responses are probably common and should be taken into account in environmental impact assessments. PMID:26862895

Predicting Effects of Water Regime Changes on Waterbirds: Insights from Staging Swans.

PubMed

Nolet, Bart A; Gyimesi, Abel; van Krimpen, Roderick R D; de Boer, Willem F; Stillman, Richard A

2016-01-01

Predicting the environmental impact of a proposed development is notoriously difficult, especially when future conditions fall outside the current range of conditions. Individual-based approaches have been developed and applied to predict the impact of environmental changes on wintering and staging coastal bird populations. How many birds make use of staging sites is mostly determined by food availability and accessibility, which in the case of many waterbirds in turn is affected by water level. Many water systems are regulated and water levels are maintained at target levels, set by management authorities. We used an individual-based modelling framework (MORPH) to analyse how different target water levels affect the number of migratory Bewick's swans Cygnus columbianus bewickii staging at a shallow freshwater lake (Lauwersmeer, the Netherlands) in autumn. As an emerging property of the model, we found strong non-linear responses of swan usage to changes in water level, with a sudden drop in peak numbers as well as bird-days with a 0.20 m rise above the current target water level. Such strong non-linear responses are probably common and should be taken into account in environmental impact assessments.

Toxicokinetics and effects of PCBs in Arctic fish: a review of studies on Arctic charr

USGS Publications Warehouse

Jorgensen, EH; Vijayan, M.N.; Killie, J.-E.A.; Aluru, N.; Aas-Hansen, O.; Maule, A.

2006-01-01

In a series of environmentally realistic laboratory experiments, toxicokinetics and effects of polychlorinated biphenyls (PCBs) were studied in the Arctic charr (Salvelinus alpinus). Winter fasting and emaciation, which are common among Arctic charr living in high latitudes, resulted in a redistribution of the lipophilic PCBs from lipid-storing tissue such as the muscle, to vital organs that must be considered sensitive toward PCB (liver and brain). This redistribution was accompanied by a significant potentiation of the hepatic cytochrome P-450 (CYP) 1A biomarker response, from low activities in October (within those measured in uncontaminated charr) to a high, probably maximum, induction in May. Performance studies demonstrated a clear effect of environmentally realistic PCB levels on endocrine mechanisms, immune function, and seawater preadaptation (smoltification) in charr that had been feed deprived for several months after contamination with Aroclor 1254, whereas a high PCB dose exerted only minor, if any, effects in charr that had been fed after contamination. These results demonstrate that emaciation results in decreased dose-response relationships in fish, and indicate that arctic animals undergoing seasonal cycles of "fattening" and emaciation may be extra sensitive toward persistent, lipophilic organochlorines. Pilot studies on Arctic charr from Bjørnøya Island revealed marked CYP1A biomarker responses and an upregulation of genes involved in cellular homeostatic mechanisms in charr from Lake Ellasjøen (high PCB levels).

Informing Disease Models with Temporal and Spatial Contact Structure among GPS-Collared Individuals in Wild Populations

PubMed Central

Williams, David M.; Dechen Quinn, Amy C.; Porter, William F.

2014-01-01

Contacts between hosts are essential for transmission of many infectious agents. Understanding how contacts, and thus transmission rates, occur in space and time is critical to effectively responding to disease outbreaks in free-ranging animal populations. Contacts between animals in the wild are often difficult to observe or measure directly. Instead, one must infer contacts from metrics such as proximity in space and time. Our objective was to examine how contacts between white-tailed deer (Odocoileus virginianus) vary in space and among seasons. We used GPS movement data from 71 deer in central New York State to quantify potential direct contacts between deer and indirect overlap in space use across time and space. Daily probabilities of direct contact decreased from winter (0.05–0.14), to low levels post-parturition through summer (0.00–0.02), and increased during the rut to winter levels. The cumulative distribution for the spatial structure of direct and indirect contact probabilities around a hypothetical point of occurrence increased rapidly with distance for deer pairs separated by 1,000 m – 7,000 m. Ninety-five percent of the probabilities of direct contact occurred among deer pairs within 8,500 m of one another, and 99% within 10,900 m. Probabilities of indirect contact accumulated across greater spatial extents: 95% at 11,900 m and 99% at 49,000 m. Contacts were spatially consistent across seasons, indicating that although contact rates differ seasonally, they occur proportionally across similar landscape extents. Distributions of contact probabilities across space can inform management decisions for assessing risk and allocating resources in response. PMID:24409293

Contrasting effects of climate change on rabbit populations through reproduction.

PubMed

Tablado, Zulima; Revilla, Eloy

2012-01-01

Climate change is affecting many physical and biological processes worldwide. Anticipating its effects at the level of populations and species is imperative, especially for organisms of conservation or management concern. Previous studies have focused on estimating future species distributions and extinction probabilities directly from current climatic conditions within their geographical ranges. However, relationships between climate and population parameters may be so complex that to make these high-level predictions we need first to understand the underlying biological processes driving population size, as well as their individual response to climatic alterations. Therefore, the objective of this study is to investigate the influence that climate change may have on species population dynamics through altering breeding season. We used a mechanistic model based on drivers of rabbit reproductive physiology together with demographic simulations to show how future climate-driven changes in breeding season result in contrasting rabbit population trends across Europe. In the Iberian Peninsula, where rabbits are a native species of high ecological and economic value, breeding seasons will shorten and become more variable leading to population declines, higher extinction risk, and lower resilience to perturbations. Whereas towards north-eastern countries, rabbit numbers are expected to increase through longer and more stable reproductive periods, which augment the probability of new rabbit invasions in those areas. Our study reveals the type of mechanisms through which climate will cause alterations at the species level and emphasizes the need to focus on them in order to better foresee large-scale complex population trends. This is especially important in species like the European rabbit whose future responses may aggravate even further its dual keystone/pest problematic. Moreover, this approach allows us to predict not only distribution shifts but also future population status and growth, and to identify the demographic parameters on which to focus to mitigate global change effects.

Contrasting Effects of Climate Change on Rabbit Populations through Reproduction

PubMed Central

Tablado, Zulima; Revilla, Eloy

2012-01-01

Background Climate change is affecting many physical and biological processes worldwide. Anticipating its effects at the level of populations and species is imperative, especially for organisms of conservation or management concern. Previous studies have focused on estimating future species distributions and extinction probabilities directly from current climatic conditions within their geographical ranges. However, relationships between climate and population parameters may be so complex that to make these high-level predictions we need first to understand the underlying biological processes driving population size, as well as their individual response to climatic alterations. Therefore, the objective of this study is to investigate the influence that climate change may have on species population dynamics through altering breeding season. Methodology/Principal Findings We used a mechanistic model based on drivers of rabbit reproductive physiology together with demographic simulations to show how future climate-driven changes in breeding season result in contrasting rabbit population trends across Europe. In the Iberian Peninsula, where rabbits are a native species of high ecological and economic value, breeding seasons will shorten and become more variable leading to population declines, higher extinction risk, and lower resilience to perturbations. Whereas towards north-eastern countries, rabbit numbers are expected to increase through longer and more stable reproductive periods, which augment the probability of new rabbit invasions in those areas. Conclusions/Significance Our study reveals the type of mechanisms through which climate will cause alterations at the species level and emphasizes the need to focus on them in order to better foresee large-scale complex population trends. This is especially important in species like the European rabbit whose future responses may aggravate even further its dual keystone/pest problematic. Moreover, this approach allows us to predict not only distribution shifts but also future population status and growth, and to identify the demographic parameters on which to focus to mitigate global change effects. PMID:23152836

The Military Response to Pandemic: The New Global Threat

DTIC Science & Technology

2009-01-28

creeping things and birds of the air, for I am sorry that I have made them.’ —Genesis 6, 71 In the last years, the appearance of incurable diseases...these diseases came from other species, smallpox probably from dogs and cattle , tuberculosis from cattle and birds, AIDS probably from African...biological levels there is astounding parallel between the visible world of the “macrobes”, where some animals feed themselves with others, and the

Locally rare species influence grassland ecosystem multifunctionality

PubMed Central

Manning, Peter; Prati, Daniel; Gossner, Martin M.; Alt, Fabian; Arndt, Hartmut; Baumgartner, Vanessa; Binkenstein, Julia; Birkhofer, Klaus; Blaser, Stefan; Blüthgen, Nico; Boch, Steffen; Böhm, Stefan; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Heinze, Johannes; Hölzel, Norbert; Jung, Kirsten; Klaus, Valentin H.; Klein, Alexandra-Maria; Kleinebecker, Till; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Morris, E. Kathryn; Müller, Jörg; Oelmann, Yvonne; Overmann, Jörg; Pašalić, Esther; Renner, Swen C.; Rillig, Matthias C.; Schaefer, H. Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Sikorski, Johannes; Socher, Stephanie A.; Solly, Emily F.; Sonnemann, Ilja; Sorkau, Elisabeth; Steckel, Juliane; Steffan-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Türke, Manfred; Venter, Paul; Weiner, Christiane N.; Weisser, Wolfgang W.; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Wolters, Volkmar; Wubet, Tesfaye; Wurst, Susanne; Fischer, Markus; Allan, Eric

2016-01-01

Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity–multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities. PMID:27114572

Locally rare species influence grassland ecosystem multifunctionality.

PubMed

Soliveres, Santiago; Manning, Peter; Prati, Daniel; Gossner, Martin M; Alt, Fabian; Arndt, Hartmut; Baumgartner, Vanessa; Binkenstein, Julia; Birkhofer, Klaus; Blaser, Stefan; Blüthgen, Nico; Boch, Steffen; Böhm, Stefan; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Heinze, Johannes; Hölzel, Norbert; Jung, Kirsten; Klaus, Valentin H; Klein, Alexandra-Maria; Kleinebecker, Till; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Morris, E Kathryn; Müller, Jörg; Oelmann, Yvonne; Overmann, Jörg; Pašalić, Esther; Renner, Swen C; Rillig, Matthias C; Schaefer, H Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Sikorski, Johannes; Socher, Stephanie A; Solly, Emily F; Sonnemann, Ilja; Sorkau, Elisabeth; Steckel, Juliane; Steffan-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Türke, Manfred; Venter, Paul; Weiner, Christiane N; Weisser, Wolfgang W; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Wolters, Volkmar; Wubet, Tesfaye; Wurst, Susanne; Fischer, Markus; Allan, Eric

2016-05-19

Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity-multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities. © 2016 The Author(s).

The effects of increased heme oxygenase-1 on the lymphoproliferative response in dogs with visceral leishmaniasis.

PubMed

Almeida, Breno Fernando Martins de; Silva, Kathlenn Liezbeth Oliveira; Chiku, Vanessa Marim; Leal, Aline Aparecida Correa; Venturin, Gabriela Lovizutto; Narciso, Luis Gustavo; Fink, Maria Fernanda Cereijido Bersni; Eugênio, Flavia de Rezende; Santos, Paulo Sergio Patto Dos; Ciarlini, Paulo Cesar; Lima, Valéria Marçal Felix de

2017-05-01

Canine visceral leishmaniasis (CVL) is known to affect the cellular immunity of infected dogs, through impairing lymphoproliferation and microbicidal mechanisms. This study examined heme oxygenase-1 (HO-1) and its metabolites, oxidative stress and IL-10 levels in CVL and investigated correlations between these parameters. Additionally, the effects of HO-1 inhibition on the lymphoproliferative response and cytokine production in lymph node cells (LNCs) from infected dogs were evaluated. Forty-four dogs, 24 controls and 20 dogs with CVL were selected. Plasma and splenic levels of HO-1, haptoglobin, soluble CD163 receptor, ferritin and IL-10 were determined using capture ELISA. The HO-1 levels and relative gene expression in peripheral blood and bone marrow mononuclear cells were also determined. LNCs proliferation was evaluated with an HO-1 activator and with an HO-1 inhibitor, in the presence of the Leishmania infantum soluble antigen (SAgL), using flow cytometry. HO-1, IL-2, IFN-gamma and IL-10 were also determined in these cultures using capture ELISA. Infected dogs presented oxidative stress and increased HO-1 levels and relative gene expression, with correlation between oxidative stress and HO-1. The substances from heme metabolism and IL-10 were also elevated in the plasma and spleens of infected dogs. IL-10 and HO-1 levels were positively correlated with one another. Inhibition of HO-1 increased LNCs proliferation and decreased IL-10 and IL-2 production in the presence of SAgL. The increased HO-1 metabolism observed in CVL is probably associated with oxidative stress and increased IL-10, which could be one of the mechanisms responsible for inhibition of the lymphoproliferative response in sick dogs. Copyright © 2016 Elsevier GmbH. All rights reserved.

Probability analysis of the relation of salinity to freshwater discharge in the St. Sebastian River, Florida

USGS Publications Warehouse

Wicklein, S.M.; Gain, W.S.

1999-01-01

The St. Sebastian River lies in the southern part of the Indian River basin on the east coast of Florida. Increases in freshwater discharge due to urbanization and changes in land use have reduced salinity in the St. Sebastian River and, consequently, salinity in the Indian River, affecting the commercial fishing industry. Wind, water temperature, tidal flux, freshwater discharge, and downstream salinity all affect salinity in the St. Sebastian River estuary, but freshwater discharge is the only one of these hydrologic factors which might be affected by water-management practices. A probability analysis of salinity conditions in the St. Sebastian River estuary, taking into account the effects of freshwater discharge over a period from May 1992 to March 1996, was used to determine the likelihood (probability) that salinities, as represented by daily mean specific- conductance values, will fall below a given threshold. The effects of freshwater discharge on salinities were evaluated with a simple volumetric model fitted to time series of measured specific conductance, by using nonlinear optimization techniques. Specific-conductance values for two depths at monitored sites represent stratified flow which results from differences in salt concentration between freshwater and saltwater. Layering of freshwater and saltwater is assumed, and the model is applied independently to each layer with the assumption that the water within the layer is well mixed. The model of specific conductance as a function of discharge (a salinity response model) was combined with a model of residual variation to produce a total probability model. Flow distributions and model residuals were integrated to produce a salinity distribution and determine differences in salinity probabilities as a result of changes in water-management practices. Two possible management alternatives were analyzed: stormwater detention (reducing the peak rate of discharge but not reducing the overall flow volume) and stormwater retention (reducing peak discharges without later release). Detention of freshwater discharges increased the probability of specific- conductance values falling below a given limit (20,000 microsiemens per centimeter) for all sites but one. The retention of freshwater input to the system decreased the likelihood of falling below a selected limit of specific conductance at all sites. For limits of specific conductance (1,000 microsiemens per centimeter or 20,000 microsiemens per centimeter, depending on the site), the predicted days of occurrence below a limit decreased ranging from 17 to 68 percent of the predicted days of occurrence for unregulated flow. The primary finding to be drawn from the discharge-salinity analysis is that an empirical-response model alone does not provide adequate information to assess the response of the system to changes in flow regime. Whether a given level of discharge can produce a given response on a given day is not as important as the probability of that response on a given day and over a period of many days. A deterministic model of the St. Sebastian River estuary based only on discharge would predict that retention of discharge peaks should increase the average salinity conditions in the St. Sebastian River estuary. The probabilistic model produces a very different response indicating that salinity can decrease by a power of three as discharges increase, and that random factors can predominate and control salinity until discharges increase sufficiently to flush the entire system of saltwater.

WWII GI Bill and Its Effect on Low Education Levels: Did the World War II GI Bill Have an Effect on High School Completion, Poverty, and Employment?

ERIC Educational Resources Information Center

Thomas, Megan D.

2017-01-01

Did the World War II (WWII) GI Bill increase the probability of completing high school and further affect the probability of poverty and employment for the cohorts for whom it benefited? This paper studies whether the GI Bill, one of the largest public financial aid policies for education, affected low education levels in addition to its…

Diminished parathyroid gland responsiveness to hypocalcemia in diabetic patients with uremia.

PubMed

Heidbreder, E; Götz, R; Schafferhans, K; Heidland, A

1986-01-01

The parathyroid gland responsiveness to hypocalcemia induced by short-term calcium-free hemodialysis in patients with insulin-dependent diabetes mellitus was investigated in comparison with 10 nondiabetic uremic patients and compared with test results from the autonomic nervous system. Diabetic patients had lower C-terminal parathyroid hormone (cPTH) levels before hemodialysis than uremic control patients and showed a significantly smaller increase in cPTH during hypocalcemia. The neurological tests revealed severe disturbances of the autonomic functions in the diabetic group. In conclusion, the disturbances observed in the parathyroid secretory pattern are probably caused by gland dysfunction; it is hypothesized that the defective autonomic nervous system has an additional effect on the development of this hormonal dysfunction.

Business cycle impacts on substance use of adolescents: A multi-country analysis.

PubMed

Paling, Thomas; Vall Castello, Judit

2017-11-01

Populations respond to changes in the economic climate in a variety of ways. The recent 'Great Recession' has brought attention to the vulnerability of many economies around the world to changes in non-domestic macroeconomic fluctuations. However, empirical evidence on the responses of adolescents' substance consumption behaviour when the economy deteriorates is very scarce. Thus, the focus of this paper is to analyse the substance consumption patterns displayed by adolescents in response to changes in macroeconomic conditions in a large number of countries. Our results show that beer and wine consumption vary counter-cyclically (a 1pp increase in the unemployment rate increases the probability of drinking beer (wine) by 3% (5.5%)) while adolescent smoking prevalence varies pro-cyclically (a 1pp increase in the unemployment rate decreases the probability of being a current smoker by 3.8%). More importantly, we find that the probability of ever being drunk increases by 1.3% for a 1pp increase in the unemployment rate. Further to this, substantial heterogeneous effects from the aggregate-level results were found when analysing a variety of demographic and geographic dimensions. In light of the existing empirical evidence which outlines that early substance initiators demonstrate worse neurological deficits and suffer stronger labour market penalties (compared to later initiators or abstainers) these findings can aid policy makers in reducing these lasting adverse outcomes. Copyright © 2017 Elsevier B.V. All rights reserved.

The American Climate Prospectus: a risk-centered analysis of the economic impacts of climate change

NASA Astrophysics Data System (ADS)

Jina, A.; Houser, T.; Hsiang, S. M.; Kopp, R. E., III; Delgado, M.; Larsen, K.; Mohan, S.; Rasmussen, D.; Rising, J.; Wilson, P. S.; Muir-Wood, R.

2014-12-01

The American Climate Prospectus (ACP), the analysis underlying the Risky Business project, quantitatively assessed the climate risks posed to the United States' economy in six sectors - crop yields, energy demand, coastal property, crime, labor productivity, and mortality [1]. The ACP is unique in its characterization of the full probability distribution of economic impacts of climate change throughout the 21st century, making it an extremely useful basis for risk assessments. Three key innovations allow for this characterization. First, climate projections from CMIP5 models are scaled to a temperature probability distribution derived from a coarser climate model (MAGICC). This allows a more accurate representation of the whole distribution of future climates (in particular the tails) than a simple ensemble average. These are downscaled both temporally and spatially. Second, a set of local sea level rise and tropical cyclone projections are used in conjunction with the most detailed dataset of coastal property in the US in order to capture the risks of rising seas and storm surge. Third, we base many of our sectors on empirically-derived responses to temperature and precipitation. Each of these dose-response functions is resampled many times to populate a statistical distribution. Combining these with uncertainty in emissions scenario, climate model, and weather, we create the full probability distribution of climate impacts from county up to national levels, as well as model the effects upon the economy as a whole. Results are presented as likelihood ranges, as well as changes to return intervals of extreme events. The ACP analysis allows us to compare between sectors to understand the magnitude of required policy responses, and also to identify risks through time. Many sectors displaying large impacts at the end of the century, like those of mortality, have smaller changes in the near-term, due to non-linearities in the response functions. Other sectors, like coastal damages, have monotonically increasing costs throughout the 21st century. Taken together, the results from the ACP presents a unique and novel view of the short-, medium-, and long-term economic risks of climate change in the US. References: [1] T. Houser et al (2014), American Climate Prospectus, www.climateprospectus.org.

Sensitivity of the Positive and Negative Syndrome Scale (PANSS) in Detecting Treatment Effects via Network Analysis.

PubMed

Esfahlani, Farnaz Zamani; Sayama, Hiroki; Visser, Katherine Frost; Strauss, Gregory P

2017-12-01

Objective: The Positive and Negative Syndrome Scale is a primary outcome measure in clinical trials examining the efficacy of antipsychotic medications. Although the Positive and Negative Syndrome Scale has demonstrated sensitivity as a measure of treatment change in studies using traditional univariate statistical approaches, its sensitivity to detecting network-level changes in dynamic relationships among symptoms has yet to be demonstrated using more sophisticated multivariate analyses. In the current study, we examined the sensitivity of the Positive and Negative Syndrome Scale to detecting antipsychotic treatment effects as revealed through network analysis. Design: Participants included 1,049 individuals diagnosed with psychotic disorders from the Phase I portion of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study. Of these participants, 733 were clinically determined to be treatment-responsive and 316 were found to be treatment-resistant. Item level data from the Positive and Negative Syndrome Scale were submitted to network analysis, and macroscopic, mesoscopic, and microscopic network properties were evaluated for the treatment-responsive and treatment-resistant groups at baseline and post-phase I antipsychotic treatment. Results: Network analysis indicated that treatment-responsive patients had more densely connected symptom networks after antipsychotic treatment than did treatment-responsive patients at baseline, and that symptom centralities increased following treatment. In contrast, symptom networks of treatment-resistant patients behaved more randomly before and after treatment. Conclusions: These results suggest that the Positive and Negative Syndrome Scale is sensitive to detecting treatment effects as revealed through network analysis. Its findings also provide compelling new evidence that strongly interconnected symptom networks confer an overall greater probability of treatment responsiveness in patients with psychosis, suggesting that antipsychotics achieve their effect by enhancing a number of central symptoms, which then facilitate reduction of other highly coupled symptoms in a network-like fashion.

CO2 induced growth response in a diatom dominated phytoplankton community from SW Bay of Bengal coastal water

NASA Astrophysics Data System (ADS)

Biswas, Haimanti; Shaik, Aziz Ur Rahman; Bandyopadhyay, Debasmita; Chowdhury, Neha

2017-11-01

The ongoing increase in surface seawater CO2 level could potentially impact phytoplankton primary production in coastal waters; however, CO2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO2 level, light and zinc (Zn) addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO2 supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ13CPOM values at elevated CO2 suggested increased CO2 diffusive influx inside the cell. Trace amount of Zn added under low CO2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO2. Almost identical values of δ13CPOM in the low CO2 treated cells grown with and without Zn indicated a low discrimination between 13C and 12C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO2. A minimum growth rate was observed at low CO2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO2 level, growth response was maximum. The cells grown in the low CO2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO2). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO2 supply and thus may enhance primary production in response to any further increase in coastal water CO2 levels and can have large biogeochemical consequences in the study area.

Lipopolysaccharide Alters Motivated Behavior in a Monetary Reward Task: a Randomized Trial.

PubMed

Lasselin, Julie; Treadway, Michael T; Lacourt, Tamara E; Soop, Anne; Olsson, Mats J; Karshikoff, Bianka; Paues-Göranson, Sofie; Axelsson, John; Dantzer, Robert; Lekander, Mats

2017-03-01

Inflammation-induced sickness is associated with a large set of behavioral alterations; however, its motivational aspects remain poorly explored in humans. The present study assessed the effect of lipopolysaccharide (LPS) administration at a dose of 2 ng/kg of body weight on motivation in 21 healthy human subjects in a double-blinded, placebo (saline)-controlled, cross-over design. Incentive motivation and reward sensitivity were measured using the Effort Expenditure for Rewards Task (EEfRT), in which motivation for high-effort/high-reward trials vs low-effort/low-reward trials are manipulated by variations in reward magnitude and probability to win. Because of the strong interactions between sleepiness and motivation, the role of sleepiness was also determined. As expected, the probability to win predicted the choice to engage in high-effort/high-reward trials; however, this occurred at a greater extent after LPS than after saline administration. This effect was related to the level of sleepiness. Sleepiness increased motivation to choose the high-effort/high-reward mode of response, but only when the probability to win was the highest. LPS had no effect on reward sensitivity either directly or via sleepiness. These results indicate that systemic inflammation induced by LPS administration causes motivational changes in young healthy subjects, which are associated with sleepiness. Thus, despite its association with energy-saving behaviors, sickness allows increased incentive motivation when the effort is deemed worthwhile.

Lipopolysaccharide Alters Motivated Behavior in a Monetary Reward Task: a Randomized Trial

PubMed Central

Lasselin, Julie; Treadway, Michael T; Lacourt, Tamara E; Soop, Anne; Olsson, Mats J; Karshikoff, Bianka; Paues-Göranson, Sofie; Axelsson, John; Dantzer, Robert; Lekander, Mats

2017-01-01

Inflammation-induced sickness is associated with a large set of behavioral alterations; however, its motivational aspects remain poorly explored in humans. The present study assessed the effect of lipopolysaccharide (LPS) administration at a dose of 2 ng/kg of body weight on motivation in 21 healthy human subjects in a double-blinded, placebo (saline)-controlled, cross-over design. Incentive motivation and reward sensitivity were measured using the Effort Expenditure for Rewards Task (EEfRT), in which motivation for high-effort/high-reward trials vs low-effort/low-reward trials are manipulated by variations in reward magnitude and probability to win. Because of the strong interactions between sleepiness and motivation, the role of sleepiness was also determined. As expected, the probability to win predicted the choice to engage in high-effort/high-reward trials; however, this occurred at a greater extent after LPS than after saline administration. This effect was related to the level of sleepiness. Sleepiness increased motivation to choose the high-effort/high-reward mode of response, but only when the probability to win was the highest. LPS had no effect on reward sensitivity either directly or via sleepiness. These results indicate that systemic inflammation induced by LPS administration causes motivational changes in young healthy subjects, which are associated with sleepiness. Thus, despite its association with energy-saving behaviors, sickness allows increased incentive motivation when the effort is deemed worthwhile. PMID:27620550

Effects of state-level public spending on health on the mortality probability in India.

PubMed

Farahani, Mansour; Subramanian, S V; Canning, David

2010-11-01

This study uses the second National Family Health Survey of India to estimate the effect of state-level public health spending on mortality across all age groups, controlling for individual, household, and state-level covariates. We use a state's gross fiscal deficit as an instrument for its health spending. Our study shows a 10% increase in public spending on health in India decreases the average probability of death by about 2%, with effects mainly on the young, the elderly, and women. Other major factors affecting mortality are rural residence, household poverty, and access to toilet facilities. Copyright © 2009 John Wiley & Sons, Ltd.

A Connection Admission Control Method for Web Server Systems

NASA Astrophysics Data System (ADS)

Satake, Shinsuke; Inai, Hiroshi; Saito, Tomoya; Arai, Tsuyoshi

Most browsers establish multiple connections and download files in parallel to reduce the response time. On the other hand, a web server limits the total number of connections to prevent from being overloaded. That could decrease the response time, but would increase the loss probability, the probability of which a newly arriving client is rejected. This paper proposes a connection admission control method which accepts only one connection from a newly arriving client when the number of connections exceeds a threshold, but accepts new multiple connections when the number of connections is less than the threshold. Our method is aimed at reducing the response time by allowing as many clients as possible to establish multiple connections, and also reducing the loss probability. In order to reduce spending time to examine an adequate threshold for web server administrators, we introduce a procedure which approximately calculates the loss probability under a condition that the threshold is given. Via simulation, we validate the approximation and show effectiveness of the admission control.

Action of ethanol low doses on heart rate variability following intravenous administration in rabbits.

PubMed

Khvedelidze, M; Chitanava, E; Nadareishvili, D; Jiqia, G; Gvasalia, M

2007-05-01

Effects of low ethanol doses on the vagosympathetic mechanisms of heart rate regulation were studied in rabbits. Analysis of heart rate variability showed that single intravenous administration of 0.5 mg/kg ethanol caused a higher probability of heart electrophysiological instability in sympathicotonics in contrast to vagotonics. This was associated with activation of the whole complex of regulatory mechanisms. In vagotonics, perturbations in power spectrum indicated on rapidly shunting of regulatory activity from lower to high levels of regulatory mechanisms to realize a "first class" undifferentiated response on stress induction. Sympathicotonics were unready to ethanol intravenous administration that resulted in reduction of all spectral component. Intravenous administration of ethanol caused a higher probability of heart electrophysiological instability in sympathicotonics then in vagotonics. It is important to consider these differences for therapeutic application of ethanol to some acute poisoning (methyl alcohol, ethylene glycol).

When contributions make a difference: explaining order effects in responsibility attribution.

PubMed

Gerstenberg, Tobias; Lagnado, David A

2012-08-01

In two experiments, we established an order effect in responsibility attributions. In line with Spellman (Journal of Experimental Psychology: General 126: 323-348, 1997), who proposed that a person's perceived causal contribution varies with the degree to which it changes the probability of the eventual outcome, Experiment 1 showed that in a team challenge in which the players contribute sequentially, the last player's blame or credit is attenuated if the team's result has already been determined prior to her acting. Experiment 2 illustrated that this attenuation effect does not overgeneralize to situations in which the experienced order of events does not map onto the objective order of events; the level of the last person's performance is only discounted if that person knew that the result was already determined. Furthermore, Experiment 1 demonstrated that responsibility attributions remain sensitive to differences in performance, even if the outcome is already determined. We suggest a theoretical extension of Spellman's model, according to which participants' responsibility attributions are determined not only by whether a contribution made a difference in the actual situation, but also by whether it would have made a difference had things turned out somewhat differently.

Sex-dependent effects of nutrition on telomere dynamics in zebra finches (Taeniopygia guttata)

PubMed Central

Noguera, Jose C.; Metcalfe, Neil B.; Boner, Winnie; Monaghan, Pat

2015-01-01

At a cellular level, oxidative stress is known to increase telomere attrition, and hence cellular senescence and risk of disease. It has been proposed that dietary micronutrients play an important role in telomere protection due to their antioxidant properties. We experimentally manipulated dietary micronutrients during early life in zebra finches (Taeniopygia guttata). We found no effects of micronutrient intake on telomere loss during chick growth. However, females given a diet high in micronutrients during sexual maturation showed reduced telomere loss; there was no such effect in males. These results suggest that micronutrients may influence rates of cellular senescence, but differences in micronutrient requirement and allocation strategies, probably linked to the development of sexual coloration, may underlie sex differences in response. PMID:25716087

Combining Probability Distributions of Wind Waves and Sea Level Variations to Assess Return Periods of Coastal Floods

NASA Astrophysics Data System (ADS)

Leijala, U.; Bjorkqvist, J. V.; Pellikka, H.; Johansson, M. M.; Kahma, K. K.

2017-12-01

Predicting the behaviour of the joint effect of sea level and wind waves is of great significance due to the major impact of flooding events in densely populated coastal regions. As mean sea level rises, the effect of sea level variations accompanied by the waves will be even more harmful in the future. The main challenge when evaluating the effect of waves and sea level variations is that long time series of both variables rarely exist. Wave statistics are also highly location-dependent, thus requiring wave buoy measurements and/or high-resolution wave modelling. As an initial approximation of the joint effect, the variables may be treated as independent random variables, to achieve the probability distribution of their sum. We present results of a case study based on three probability distributions: 1) wave run-up constructed from individual wave buoy measurements, 2) short-term sea level variability based on tide gauge data, and 3) mean sea level projections based on up-to-date regional scenarios. The wave measurements were conducted during 2012-2014 on the coast of city of Helsinki located in the Gulf of Finland in the Baltic Sea. The short-term sea level distribution contains the last 30 years (1986-2015) of hourly data from Helsinki tide gauge, and the mean sea level projections are scenarios adjusted for the Gulf of Finland. Additionally, we present a sensitivity test based on six different theoretical wave height distributions representing different wave behaviour in relation to sea level variations. As these wave distributions are merged with one common sea level distribution, we can study how the different shapes of the wave height distribution affect the distribution of the sum, and which one of the components is dominating under different wave conditions. As an outcome of the method, we obtain a probability distribution of the maximum elevation of the continuous water mass, which enables a flexible tool for evaluating different risk levels in the current and future climate.

Modeling CCN effects on tropical convection: An statistical perspective

NASA Astrophysics Data System (ADS)

Carrio, G. G.; Cotton, W. R.; Massie, S. T.

2012-12-01

This modeling study examines the response of tropical convection to the enhancement of CCN concentrations from a statistical perspective. The sensitivity runs were performed using RAMS version 6.0, covering almost the entire Amazonian Aerosol Characterization Experiment period (AMAZE, wet season of 2008). The main focus of the analysis was the indirect aerosol effects on the probability density functions (PDFs) of various cloud properties. RAMS was configured to work with four two-way interactive nested grids with 42 vertical levels and horizontal grid spacing of 150, 37.5, 7.5, and 1.5 km. Grids 2 and 3 were used to simulate the synoptic and mesoscale environments, while grid 4 was used to resolve deep convection. Comparisons were made using the finest grid with a domain size of 300 X 300km, approximately centered on the city of Manaus (3.1S, 60.01W). The vertical grid was stretched using with 75m spacing at the finest levels to provide better resolution within the first 1.5 km, and the model top extended to approximately 22 km above ground level. RAMS was initialized on February 10 2008 (00:00 UTC), the length of simulations was 32 days, and GSF data were used for initialization and nudging of the coarser-grid boundaries. The control run considered a CCN concentration of 300cm-3 while other several other simulations considered an influx of higher CCN concentrations (up to 1300/cc) . The latter concentration was observed near the end of the AMAZE project period. Both direct and indirect effects of these CCN particles were considered. Model output data (finest grid) every 15 min were used to compute the PDFs for each model level. When increasing aerosol concentrations, significant impacts were simulated for the PDFs of the water contents of various hydrometeors, vertical motions, area with precipitation, latent heat releases, among other quantities. In most cases, they exhibited a peculiar non-monotonic response similar to that seen in two previous studies of ours (for isolated cloud systems). It is well known that a reduction in sizes of cloud droplets reduces coalescence, increases their probability of reaching super-cooled levels, and convective cells are intensified by additional release of latent heat of freezing. However, indirect aerosol effects tend to revert when aerosol concentrations are greatly enhanced due to the riming efficiency reduction of ice particles. However, some quantities show a different response; for instance, the water content associated with small ice crystals large contents are always more likely at high levels when considering air masses more polluted in terms of CCN. Conversely, the PDF's of water contents of larger ice crystals at high altitudes exhibit the aforementioned non-monotonic behavior.

Empirical models of transitions between coral reef states: effects of region, protection, and environmental change.

PubMed

Lowe, Phillip K; Bruno, John F; Selig, Elizabeth R; Spencer, Matthew

2011-01-01

There has been substantial recent change in coral reef communities. To date, most analyses have focussed on static patterns or changes in single variables such as coral cover. However, little is known about how community-level changes occur at large spatial scales. Here, we develop Markov models of annual changes in coral and macroalgal cover in the Caribbean and Great Barrier Reef (GBR) regions. We analyzed reef surveys from the Caribbean and GBR (1996-2006). We defined a set of reef states distinguished by coral and macroalgal cover, and obtained Bayesian estimates of the annual probabilities of transitions between these states. The Caribbean and GBR had different transition probabilities, and therefore different rates of change in reef condition. This could be due to differences in species composition, management or the nature and extent of disturbances between these regions. We then estimated equilibrium probability distributions for reef states, and coral and macroalgal cover under constant environmental conditions. In both regions, the current distributions are close to equilibrium. In the Caribbean, coral cover is much lower and macroalgal cover is higher at equilibrium than in the GBR. We found no evidence for differences in transition probabilities between the first and second halves of our survey period, or between Caribbean reefs inside and outside marine protected areas. However, our power to detect such differences may have been low. We also examined the effects of altering transition probabilities on the community state equilibrium, along a continuum from unfavourable (e.g., increased sea surface temperature) to favourable (e.g., improved management) conditions. Both regions showed similar qualitative responses, but different patterns of uncertainty. In the Caribbean, uncertainty was greatest about effects of favourable changes, while in the GBR, we are most uncertain about effects of unfavourable changes. Our approach could be extended to provide risk analysis for management decisions.

No evidence for an effect of traffic noise on the development of the corticosterone stress response in an urban exploiter.

PubMed

Angelier, Frédéric; Meillère, Alizée; Grace, Jacquelyn K; Trouvé, Colette; Brischoux, François

2016-06-01

Anthropogenic noise can have important physiological and behavioral effects on wild animals. For example, urban noise could lead to a state of chronic stress and could alter the development of the hypothalamus-pituitary-adrenal (HPA) axis. Supporting this hypothesis, several studies have found that human disturbance is associated with increased circulating corticosterone (CORT) levels. However, it remains unclear whether increased CORT levels are the result of anthropogenic noise or other anthropogenic factors. Here, we experimentally tested the impact of urban noise on the CORT stress response in an urban exploiter (the house sparrow, Passer domesticus) by exposing chicks to a traffic noise ('disturbed chicks') or not ('control chicks'). If noise exposure has a negative impact on developing chicks, we predicted that (1) disturbed chicks will grow slower, will be in poorer condition, and will have a lower fledging probability than controls; (2) disturbed chicks will have higher baseline CORT levels than control; (3) the CORT stress response will be affected by this noise exposure. Contrary to these predictions, we found no effect of our experiment on growth, body condition, and fledging success, suggesting that house sparrow chicks were not negatively affected by this noise exposure. Moreover, we did not find any effect of noise exposure on either baseline CORT levels or the CORT stress response of chicks. This suggests not only that house sparrow chicks did not perceive this noise as stressful, but also that the development of the HPA axis was not affected by such noise exposure. Our study suggests that, contrary to urban avoiders, urban exploiters might be relatively insensitive to urban noise during their development. Further comparative studies are now needed to understand whether such insensitivity to anthropogenic noise is a consistent phenomenon in urban exploiters and whether this is a major requirement of an urban way of life. Copyright © 2015 Elsevier Inc. All rights reserved.

Water-level decline in the Apalachicola River, Florida, from 1954 to 2004, and effects on floodplain habitats

USGS Publications Warehouse

Light, Helen M.; Vincent, Kirk R.; Darst, Melanie R.; Price, Franklin D.

2006-01-01

From 1954 to 2004, water levels declined in the nontidal reach of the Apalachicola River, Florida, as a result of long-term changes in stage-discharge relations. Channel widening and deepening, which occurred throughout much of the river, apparently caused the declines. The period of most rapid channel enlargement began in 1954 and occurred primarily as a gradual erosional process over two to three decades, probably in response to the combined effect of a dam located at the head of the study reach (106 miles upstream from the mouth of the river), river straightening, dredging, and other activities along the river. Widespread recovery has not occurred, but channel conditions in the last decade (1995-2004) have been relatively stable. Future channel changes, if they occur, are expected to be minor. The magnitude and extent of water-level decline attributable to channel changes was determined by comparing pre-dam stage (prior to 1954) and recent stage (1995-2004) in relation to discharge. Long-term stage data for the pre-dam period and recent period from five streamflow gaging stations were related to discharge data from a single gage just downstream from the dam, by using a procedure involving streamflow lag times. The resulting pre-dam and recent stage-discharge relations at the gaging stations were used in combination with low-flow water-surface profile data from the U.S. Army Corps of Engineers to estimate magnitude of water-level decline at closely spaced locations (every 0.1 mile) along the river. The largest water-level declines occurred at the lowest discharges and varied with location along the river. The largest water-level decline, 4.8 feet, which occurred when sediments were scoured from the streambed just downstream from the dam, has been generally known and described previously. This large decline progressively decreased downstream to a magnitude of 1 foot about 40 river miles downstream from the dam, which is the location that probably marks the downstream limit of the influence of the dam on bed scour. Downstream from that location, previously unreported water-level declines progressively increased to 3 feet at a location 68 miles downstream from the dam, probably as a result of various channel modifications conducted in that part of the river. Water-level declines in the river have substantially changed long-term hydrologic conditions in more than 200 miles of off-channel floodplain sloughs, streams, and lakes and in most of the 82,200 acres of floodplain forests in the nontidal reach of the Apalachicola River. Decreases in duration of floodplain inundation at low discharges were large in the upstream-most 10 miles of the river (20-45 percent) and throughout most of the remaining 75 miles of the nontidal reach (10-25 percent). As a consequence of this decreased inundation, the quantity and quality of floodplain habitats for fish, mussels, and other aquatic organisms have declined, and wetland forests of the floodplain are changing in response to drier conditions. Water-level decline caused by channel change is probably the most serious anthropogenic impact that has occurred so far in the Apalachicola River and floodplain. This decline has been exacerbated by long-term reductions in spring and summer flow, especially during drought periods. Although no trends in total annual flow volumes were detected, long-term decreases in discharge for April, May, July, and August were apparent, and water-level declines during drought conditions resulting from decreased discharge in those 4 months were similar in magnitude to the water-level declines caused by channel changes. The observed changes in seasonal discharge are probably caused by a combination of natural climatic changes and anthropogenic activities in the Apalachicola-Chattahoochee-Flint River Basin. Continued research is needed for geomorphic studies to assist in the design of future floodplain restoration efforts and for hydrologic studies to monitor change

Ethylenediurea as a potential tool in evaluating ozone phytotoxicity: a review study on physiological, biochemical and morphological responses of plants.

PubMed

Tiwari, Supriya

2017-06-01

Present-day climate change scenario has intensified the problem of continuously increasing ground-level ozone (O 3 ), which is responsible for causing deleterious effects on growth and development of plants. Studies involving use of ethylenediurea (EDU), a chemical with antiozonant properties, have given some promising results in evaluating O 3 injury in plants. The use of EDU is especially advantageous in developing countries which face a more severe problem of ground-level O 3 , and technical O 3 -induced yield loss assessment techniques like open-top chambers cannot be used. Recent studies have detected a hormetic response of EDU on plants; i.e. treatment with higher EDU concentrations may or may not show any adverse effect on plants depending upon the experimental conditions. Although the mode of action of EDU is still debated, it is confirmed that EDU remains confined in the apoplastic regions. Certain studies indicate that EDU significantly affects the electron transport chain and has positive impact on the antioxidant defence machinery of the plants. However, the mechanism of protecting the yield of plants without significantly affecting photosynthesis is still questionable. This review discusses in details the probable mode of action of EDU on the basis of available data along with the impact of EDU on physiological, biochemical, growth and yield response of plants under O 3 stress. Data regarding the effect of EDU on plant 'omics' is highly insufficient and can form an important aspect of future EDU research.

Pretreatment Carbohydrate Antigen 19-9 Level Indicates Tumor Response, Early Distant Metastasis, Overall Survival, and Therapeutic Selection in Localized and Unresectable Pancreatic Cancer

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

Yoo, Tae; Lee, Woo Jin; Woo, Sang Myung

2011-11-15

Purpose: The use of chemoradiotherapy (CRT) for localized and unresectable pancreatic cancer has been disputed because of high probability of distant metastasis. Thus, we analyzed the effect of clinical parameters on tumor response, early distant metastasis within 3 months (DM{sup 3m}), and overall survival to identify an indicator for selecting patients who would benefit from CRT. Methods and Materials: This study retrospectively analyzed the data from 84 patients with localized and unresectable pancreatic cancer who underwent CRT between August 2002 and October 2009. Sex, age, tumor size, histological differentiation, N classification, pre- and post-treatment carbohydrate antigen (CA) 19-9 level, andmore » CA 19-9 percent decrease were analyzed to identify risk factors associated with tumor response, DM{sup 3m}, and overall survival. Results: For all 84 patients, the median survival time was 12.5 months (range, 2-31.9 months), objective response (complete response or partial response) to CRT was observed in 28 patients (33.3%), and DM{sup 3m} occurred in 24 patients (28.6%). Multivariate analysis showed that pretreatment CA 19-9 level ({<=}400 vs. >400 U/ml) was significantly associated with tumor response (45.1% vs. 15.2%), DM{sup 3m} (19.6% vs. 42.4%), and median overall survival time (15.1 vs. 9.7 months) (p < 0.05 for all three parameters). Conclusion: For patients with localized and unresectable pancreatic cancer, pretreatment CA 19-9 level could be helpful in predicting tumor response, DM{sup 3m}, and overall survival and identifying patients who will benefit from CRT.« less

The impact of Relative Prevalence on dual-target search for threat items from airport X-ray screening.

PubMed

Godwin, Hayward J; Menneer, Tamaryn; Cave, Kyle R; Helman, Shaun; Way, Rachael L; Donnelly, Nick

2010-05-01

The probability of target presentation in visual search tasks influences target detection performance: this is known as the prevalence effect (Wolfe et al., 2005). Additionally, searching for several targets simultaneously reduces search performance: this is known as the dual-target cost (DTC: Menneer et al., 2007). The interaction between the DTC and prevalence effect was investigated in a single study by presenting one target in dual-target search at a higher level of prevalence than the other target (Target A: 45% Prevalence; Target B: 5% Prevalence). An overall DTC was found for both RTs and response accuracy. Furthermore, there was an effect of target prevalence in dual-target search, suggesting that, when one target is presented at a higher level of prevalence than the other, both the dual-target cost and the prevalence effect contribute to decrements in performance. The implications for airport X-ray screening are discussed. Copyright 2010 Elsevier B.V. All rights reserved.

Exposure-Response Modeling to Characterize the Relationship Between Ixekizumab Serum Drug Concentrations and Efficacy Responses at Week 12 in Patients With Moderate to Severe Plaque Psoriasis.

PubMed

Chigutsa, Emmanuel; de Mendizabal, Nieves Velez; Chua, Laiyi; Heathman, Michael; Friedrich, Stuart; Jackson, Kimberley; Reich, Kristian

2018-06-07

Ixekizumab, a high-affinity monoclonal antibody, selectively targets interleukin-17A and has been shown to be efficacious in the treatment of moderate to severe psoriasis. The objective was to describe the relationship between ixekizumab concentrations and efficacy response (static Physician Global Assessment [sPGA] and the Psoriasis Activity and Severity Index [PASI) scores] after 12 weeks of ixekizumab treatment in psoriasis patients from 3 phase 3 studies. Data from 2888 psoriasis patients randomized to receive placebo or 80 mg ixekizumab every 2 weeks or every 4 weeks were analyzed. Separate logistic regression models describing the relationship between ixekizumab concentrations and sPGA or PASI scores at week 12 were used to determine the probability of patients achieving a response and to investigate the impact of various patient factors other than drug concentrations on response rates. Both dosing regimens were efficacious, with higher rates of response achieved with the higher range of observed ixekizumab concentrations after every-2-week dosing. Although higher bodyweight, palmoplantar involvement, lower baseline disease state, or high baseline C-reactive protein were associated with slightly lower response rates, the magnitude of effect of these factors on sPGA(0,1) response was small, with all subgroups able to achieve high levels of response. Other factors tested had no effect including age, sex, and antidrug antibody status. Logistic regression modeling of ixekizumab concentration and efficacy data accurately identified the proportion of responders using sPGA or PASI end points. The higher concentration ranges achieved with 80 mg every 2 weeks versus every 4 weeks were associated with higher response levels. © 2018, The American College of Clinical Pharmacology.

Effectiveness of headgear in football

PubMed Central

Withnall, C; Shewchenko, N; Wonnacott, M; Dvorak, J; Scott, D

2005-01-01

Objectives: Commercial headgear is currently being used by football players of all ages and skill levels to provide protection from heading and direct impact. The clinical and biomechanical effectiveness of the headgear in attenuating these types of impact is not well defined or understood. This study was conducted to determine whether football headgear has an effect on head impact responses. Methods: Controlled laboratory tests were conducted with a human volunteer and surrogate head/neck system. The impact attenuation of three commercial headgears during ball impact speeds of 6–30 m/s and in head to head contact with a closing speed of 2–5 m/s was quantified. The human subject, instrumented to measure linear and angular head accelerations, was exposed to low severity impacts during heading in the unprotected and protected states. High severity heading contact and head to head impacts were studied with a biofidelic surrogate headform instrumented to measure linear and angular head responses. Subject and surrogate responses were compared with published injury assessment functions associated with mild traumatic brain injury (MTBI). Results: For ball impacts, none of the headgear provided attenuation over the full range of impact speeds. Head responses with or without headgear were not significantly different (p>0.05) and remained well below levels associated with MTBI. In head to head impact tests the headgear provided an overall 33% reduction in impact response. Conclusion: The football headgear models tested did not provide benefit during ball impact. This is probably because of the large amount of ball deformation relative to headband thickness. However, the headgear provided measurable benefit during head to head impacts. PMID:16046355

Concurrent performance in a three-alternative choice situation: response allocation in a Rock/Paper/Scissors game.

PubMed

Kangas, Brian D; Berry, Meredith S; Cassidy, Rachel N; Dallery, Jesse; Vaidya, Manish; Hackenberg, Timothy D

2009-10-01

Adult human subjects engaged in a simulated Rock/Paper/Scissors game against a computer opponent. The computer opponent's responses were determined by programmed probabilities that differed across 10 blocks of 100 trials each. Response allocation in Experiment 1 was well described by a modified version of the generalized matching equation, with undermatching observed in all subjects. To assess the effects of instructions on response allocation, accurate probability-related information on how the computer was programmed to respond was provided to subjects in Experiment 2. Five of 6 subjects played the counter response of the computer's dominant programmed response near-exclusively (e.g., subjects played paper almost exclusively if the probability of rock was high), resulting in minor overmatching, and higher reinforcement rates relative to Experiment 1. On the whole, the study shows that the generalized matching law provides a good description of complex human choice in a gaming context, and illustrates a promising set of laboratory methods and analytic techniques that capture important features of human choice outside the laboratory.

Probabilistic evaluation of uncertainties and risks in aerospace components

NASA Technical Reports Server (NTRS)

Shah, A. R.; Shiao, M. C.; Nagpal, V. K.; Chamis, C. C.

1992-01-01

This paper summarizes a methodology developed at NASA Lewis Research Center which computationally simulates the structural, material, and load uncertainties associated with Space Shuttle Main Engine (SSME) components. The methodology was applied to evaluate the scatter in static, buckling, dynamic, fatigue, and damage behavior of the SSME turbo pump blade. Also calculated are the probability densities of typical critical blade responses, such as effective stress, natural frequency, damage initiation, most probable damage path, etc. Risk assessments were performed for different failure modes, and the effect of material degradation on the fatigue and damage behaviors of a blade were calculated using a multi-factor interaction equation. Failure probabilities for different fatigue cycles were computed and the uncertainties associated with damage initiation and damage propagation due to different load cycle were quantified. Evaluations on the effects of mistuned blades on a rotor were made; uncertainties in the excitation frequency were found to significantly amplify the blade responses of a mistuned rotor. The effects of the number of blades on a rotor were studied. The autocorrelation function of displacements and the probability density function of the first passage time for deterministic and random barriers for structures subjected to random processes also were computed. A brief discussion was included on the future direction of probabilistic structural analysis.

Protective effects of blueberries (Vaccinium corymbosum L.) extract against cadmium-induced hepatotoxicity in mice.

PubMed

Gong, Pin; Chen, Fu-xin; Wang, Lan; Wang, Jing; Jin, Sai; Ma, Yang-min

2014-05-01

The oxidative status and morphological changes of mouse liver exposed to cadmium chloride (Cd(II)) and therapeutic potential of blueberry (Vaccinium corymbosum L.) extract against Cd(II)-induced hepatic injury were investigated. A variety of parameters were evaluated, including lipid peroxidation (LPO), protein carbonyl (PCO) level, DNA fragment, as well as antioxidative defense system (i.e., superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH)). Elemental analysis and evaluation of morphological changes and NO levels were also performed. Exposure to Cd(II) led to increased LPO and PCO as well as DNA fragment and a reduction of SOD and CAT activities, however, the content of GSH elevated probably due to biological adaptive-response. In contrast, co-treatment of anthocyanin (Ay) inhibited the increased oxidative parameters as well as restored the activities of antioxidative defense system in a dose-dependent manner. Ay administration regained these morphological changes caused by intoxication of Cd(II) to nearly normal levels. Moreover, the accumulation of Cd(II) in liver may be one of the reasons for Cd(II) toxicity and Ay can chelate with Cd(II) to reduce Cd(II) burden. The influence of Cd(II) on the Zn and Ca levels can also be adjusted by the co-administration of Ay. Exposure to Cd(II) led to an increase of NO and Ay reduced NO contents probably by directly scavenging. Potential mechanisms for the protective effect of Ay have been proposed, including its anti-oxidative and anti-inflammatory effect along with the metal-chelating capacity. These results suggest that blueberry extract may be valuable as a therapeutic agent in combating Cd(II)-induced tissue injury. Copyright © 2014 Elsevier B.V. All rights reserved.

Predictors of two forms of attrition in a longitudinal health study involving ageing participants: an analysis based on the Whitehall II study.

PubMed

Mein, Gill; Johal, Suneeta; Grant, Robert L; Seale, Clive; Ashcroft, Richard; Tinker, Anthea

2012-10-29

Longitudinal studies are crucial providers of information about the needs of an ageing population, but their external validity is affected if partipants drop out. Previous research has identified older age, impaired cognitive function, lower educational level, living alone, fewer social activities, and lower socio-economic status as predictors of attrition. This project examined attrition in participants of the Whitehall II study aged between 51-71 years, using data from questionnaires participants have completed biennially since 1985 when the study began. We examine the possibility of two distinct forms of attrition--non-response and formally requesting to withdraw--and whether they have different predictors. Potential predictors were age, gender, marital status, occupational grade, retirement, home ownership, presence of longstanding illness, SF-36 quality of life scores, social participation and educational level comparing participants and those who had withdrawn from the study. The two forms of attrition share many predictors and are associated but remain distinct. Being older, male, having a lower job grade, not being a home owner, not having a long standing illness, having higher levels of education, and not having retired, were all associated with a greater probability of non-response; being married was associated with higher probability in women and lower in men. Being older, male, having a lower job grade, not being a home owner, having lower SF-36 scores, taking part in fewer social activities, and not having a long standing illness, were all associated with greater probability of withdrawal. The results suggest a strong gender effect on both routes not previously considered in analyses of attrition. Investigators of longitudinal studies should take measures to retain older participants and lower level socio-economic participants, who are more likely to cease participating. Recognition should be given to the tendency for people with health problems to be more diligent participants in studies with a medical screening aspect, and for those with lower socio-economic status (including home ownership), quality of life and social participation, to be more likely to request withdrawal. Without taking these features into account, bias and loss of power could affect statistical analyses.

Paucity of attractors in nonlinear systems driven with complex signals.

PubMed

Pethel, Shawn D; Blakely, Jonathan N

2011-04-01

We study the probability of multistability in a quadratic map driven repeatedly by a random signal of length N, where N is taken as a measure of the signal complexity. We first establish analytically that the number of coexisting attractors is bounded above by N. We then numerically estimate the probability p of a randomly chosen signal resulting in a multistable response as a function of N. Interestingly, with increasing drive signal complexity the system exhibits a paucity of attractors. That is, almost any drive signal beyond a certain complexity level will result in a single attractor response (p=0). This mechanism may play a role in allowing sensitive multistable systems to respond consistently to external influences.

Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

USGS Publications Warehouse

Espinar, J.L.; Garcia, L.V.; Clemente, L.

2005-01-01

The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

A meta-analysis of response-time tests of the sequential two-systems model of moral judgment.

PubMed

Baron, Jonathan; Gürçay, Burcu

2017-05-01

The (generalized) sequential two-system ("default interventionist") model of utilitarian moral judgment predicts that utilitarian responses often arise from a system-two correction of system-one deontological intuitions. Response-time (RT) results that seem to support this model are usually explained by the fact that low-probability responses have longer RTs. Following earlier results, we predicted response probability from each subject's tendency to make utilitarian responses (A, "Ability") and each dilemma's tendency to elicit deontological responses (D, "Difficulty"), estimated from a Rasch model. At the point where A = D, the two responses are equally likely, so probability effects cannot account for any RT differences between them. The sequential two-system model still predicts that many of the utilitarian responses made at this point will result from system-two corrections of system-one intuitions, hence should take longer. However, when A = D, RT for the two responses was the same, contradicting the sequential model. Here we report a meta-analysis of 26 data sets, which replicated the earlier results of no RT difference overall at the point where A = D. The data sets used three different kinds of moral judgment items, and the RT equality at the point where A = D held for all three. In addition, we found that RT increased with A-D. This result holds for subjects (characterized by Ability) but not for items (characterized by Difficulty). We explain the main features of this unanticipated effect, and of the main results, with a drift-diffusion model.

Probability of atrial fibrillation after ablation: Using a parametric nonlinear temporal decomposition mixed effects model.

PubMed

Rajeswaran, Jeevanantham; Blackstone, Eugene H; Ehrlinger, John; Li, Liang; Ishwaran, Hemant; Parides, Michael K

2018-01-01

Atrial fibrillation is an arrhythmic disorder where the electrical signals of the heart become irregular. The probability of atrial fibrillation (binary response) is often time varying in a structured fashion, as is the influence of associated risk factors. A generalized nonlinear mixed effects model is presented to estimate the time-related probability of atrial fibrillation using a temporal decomposition approach to reveal the pattern of the probability of atrial fibrillation and their determinants. This methodology generalizes to patient-specific analysis of longitudinal binary data with possibly time-varying effects of covariates and with different patient-specific random effects influencing different temporal phases. The motivation and application of this model is illustrated using longitudinally measured atrial fibrillation data obtained through weekly trans-telephonic monitoring from an NIH sponsored clinical trial being conducted by the Cardiothoracic Surgery Clinical Trials Network.

Direct Inhibitory Effect of Hypercalcemia on Renal Actions of Parathyroid Hormone

PubMed Central

Beck, Nama; Singh, Harbans; Reed, Sarah W.; Davis, Bernard B.

1974-01-01

The effects of calcium on the renal actions of parathyroid hormone (PTH) were studied in vivo and in vitro. In parathyroidectomized rats, variable levels of blood calcium concentration were induced by intravenous infusion of calcium. The renal responses to the injected PTH, i.e. phosphate and cyclic AMP excretion, were compared in these animals. After PTH injection, the increases of both phosphate and cyclic AMP excretion were less in the calcium-infused animals than in the control group without calcium infusion. There was an inverse correlation between the renal responses to PTH and plasma calcium concentration of 4.2-13.5 mg/100 ml. But calcium had no effect on phosphate excretion induced by infusion of dibutyryl cyclic AMP. In the in vitro experiments, the increase of cyclic AMP concentration in response to PTH was less in renal cortical slices taken from the calcium-infused animals than in ones from the control group without calcium infusion. Calcium also inhibited the activation of renal cortical adenylate cyclase in response to PTH, but calcium had no effect on phosphodiesterase. The data indicate that calcium directly inhibits renal actions of PTH both in vivo and in vitro. Such inhibitory mechanism is probably at or before the step of PTH-dependent cyclic AMP generation in the kidney. PMID:4359938

Communicating uncertainty: managing the inherent probabilistic character of hazard estimates

NASA Astrophysics Data System (ADS)

Albarello, Dario

2013-04-01

Science is much more fixing the limits of our knowledge about possible occurrences than the identification of any "truth". This is particularly true when scientific statements concern prediction of natural phenomena largely exceeding the laboratory scale as in the case of seismogenesis. In these cases, many scenarios about future occurrences result possible (plausible) and the contribution of scientific knowledge (based on the available knowledge about underlying processes or the phenomenological studies) mainly consists in attributing to each scenario a different level of likelihood (probability). In other terms, scientific predictions in the field of geosciences (hazard assessment) are inherently probabilistic. However, despite of this, many scientist (seismologists, etc.) in communicating their position in public debates tend to stress the " truth" of their statements against the fancy character of pseudo-scientific assertions: stronger is the opposition of science and pseudo-science, more hidden becomes the probabilistic character of scientific statements. The problem arises when this kind of "probabilistic" knowledge becomes the basis of any political action (e.g., to impose expensive form of risk reducing activities): in these cases the lack of any definitive "truth" requires a direct assumption of responsibility by the relevant decider (being the single citizen or the legitimate expression of a larger community) to choose among several possibilities (however characterized by different levels of likelihood). In many cases, this can be uncomfortable and strong is the attitude to delegate to the scientific counterpart the responsibility of these decisions. This "transfer" from the genuine political field to an improper scientific context is also facilitated by the lack of a diffuse culture of "probability" outside the scientific community (and in many cases inside also). This is partially the effect of the generalized adoption (by media and scientific communicators) of a view of probability (the "frequentist" view) that is useful in scientific practice but is very far from the common use of uncertain reasoning (that is nearer to the "epistemic" view). Considering probability a sort of physical measure inherent in the process under examination (like an acceleration value) instead of a degree of belief (rationally inferred) about any statement concerning future occurrences tends to hide the importance of a shared responsibility about relevant choices that involves scientists and citizens in the same extent.

Calibrating perceived understanding and competency in probability concepts: A diagnosis of learning difficulties based on Rasch probabilistic model

NASA Astrophysics Data System (ADS)

Mahmud, Zamalia; Porter, Anne; Salikin, Masniyati; Ghani, Nor Azura Md

2015-12-01

Students' understanding of probability concepts have been investigated from various different perspectives. Competency on the other hand is often measured separately in the form of test structure. This study was set out to show that perceived understanding and competency can be calibrated and assessed together using Rasch measurement tools. Forty-four students from the STAT131 Understanding Uncertainty and Variation course at the University of Wollongong, NSW have volunteered to participate in the study. Rasch measurement which is based on a probabilistic model is used to calibrate the responses from two survey instruments and investigate the interactions between them. Data were captured from the e-learning platform Moodle where students provided their responses through an online quiz. The study shows that majority of the students perceived little understanding about conditional and independent events prior to learning about it but tend to demonstrate a slightly higher competency level afterward. Based on the Rasch map, there is indication of some increase in learning and knowledge about some probability concepts at the end of the two weeks lessons on probability concepts.

Word Recognition and Nonword Repetition in Children with Language Disorders: The Effects of Neighborhood Density, Lexical Frequency, and Phonotactic Probability

ERIC Educational Resources Information Center

Rispens, Judith; Baker, Anne; Duinmeijer, Iris

2015-01-01

Purpose: The effects of neighborhood density (ND) and lexical frequency on word recognition and the effects of phonotactic probability (PP) on nonword repetition (NWR) were examined to gain insight into processing at the lexical and sublexical levels in typically developing (TD) children and children with developmental language problems. Method:…

Bayesian hierarchical modeling for subject-level response classification in peptide microarray immunoassays

PubMed Central

Imholte, Gregory; Gottardo, Raphael

2017-01-01

Summary The peptide microarray immunoassay simultaneously screens sample serum against thousands of peptides, determining the presence of antibodies bound to array probes. Peptide microarrays tiling immunogenic regions of pathogens (e.g. envelope proteins of a virus) are an important high throughput tool for querying and mapping antibody binding. Because of the assay’s many steps, from probe synthesis to incubation, peptide microarray data can be noisy with extreme outliers. In addition, subjects may produce different antibody profiles in response to an identical vaccine stimulus or infection, due to variability among subjects’ immune systems. We present a robust Bayesian hierarchical model for peptide microarray experiments, pepBayes, to estimate the probability of antibody response for each subject/peptide combination. Heavy-tailed error distributions accommodate outliers and extreme responses, and tailored random effect terms automatically incorporate technical effects prevalent in the assay. We apply our model to two vaccine trial datasets to demonstrate model performance. Our approach enjoys high sensitivity and specificity when detecting vaccine induced antibody responses. A simulation study shows an adaptive thresholding classification method has appropriate false discovery rate control with high sensitivity, and receiver operating characteristics generated on vaccine trial data suggest that pepBayes clearly separates responses from non-responses. PMID:27061097

Attention Modulates Spatial Precision in Multiple-Object Tracking.

PubMed

Srivastava, Nisheeth; Vul, Ed

2016-01-01

We present a computational model of multiple-object tracking that makes trial-level predictions about the allocation of visual attention and the effect of this allocation on observers' ability to track multiple objects simultaneously. This model follows the intuition that increased attention to a location increases the spatial resolution of its internal representation. Using a combination of empirical and computational experiments, we demonstrate the existence of a tight coupling between cognitive and perceptual resources in this task: Low-level tracking of objects generates bottom-up predictions of error likelihood, and high-level attention allocation selectively reduces error probabilities in attended locations while increasing it at non-attended locations. Whereas earlier models of multiple-object tracking have predicted the big picture relationship between stimulus complexity and response accuracy, our approach makes accurate predictions of both the macro-scale effect of target number and velocity on tracking difficulty and micro-scale variations in difficulty across individual trials and targets arising from the idiosyncratic within-trial interactions of targets and distractors. Copyright © 2016 Cognitive Science Society, Inc.

Lead-induced anemia: Dose-response relationships and evidence for a threshold

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

Schwartz, J.; Landrigan, P.J.; Baker, E.L. Jr.

1990-02-01

We conducted a cross-sectional epidemiologic study to assess the association between blood lead level and hematocrit in 579 one to five year-old children living near a primary lead smelter in 1974. Blood lead levels ranged from 0.53 to 7.91 mumol/L (11 to 164 micrograms/dl). To predict hematocrit as a function of blood lead level and age, we derived non-linear regression models and fit percentile curves. We used logistic regression to predict the probability of hematocrit values less than 35 per cent. We found a strong non-linear, dose-response relationship between blood lead level and hematocrit. This relationship was influenced by age,more » but (in this age group) not by sex; the effect was strongest in youngest children. In one year-olds, the age group most severely affected, the risk of an hematocrit value below 35 percent was 2 percent above background at blood lead levels between 0.97 and 1.88 mumol/L (20 and 39 micrograms/dl), 18 percent above background at lead levels of 1.93 to 2.85 mumol/L (40 to 59 micrograms/dl), and 40 percent above background at lead levels of 2.9 mumol/L (60 micrograms/dl) and greater; background was defined as a blood lead level below 1.88 mumol/L (20 micrograms/dl). This effect appeared independent of iron deficiency. These findings suggest that blood lead levels close to the currently recommended limit value of 1.21 mumol/L (25 micrograms/dl) are associated with dose-related depression of hematocrit in young children.« less

Cueing properties of the decrease of white noise intensity for avoidance conditioning in cats.

PubMed

Zieliński, K

1979-01-01

In the main experiment two groups of 6 cats each were trained in active bar-pressing avoidance to a CS consisting of either a 10 dB or 20 dB decrease of the background white noise of 70 dB intensity. The two groups did not differ in rapidity of learning, however cats trained to the greater change .in background noise performed avoidance responses with shorter latencies than did cats trained to smaller change. Within-groups comparisons of cumulative distributions of response latencies for consecutive Vincentized fifths of avoidance acquisition showed the greatest changes in the region of latencies longer than the median latency of instrumental responses. On the other hand, the effects of CS intensity found in between-groups comparisons were located in the region of latencies shorter than the median latency of either group. Comparisons with data obtained in a complementary experiment employing additional 17 cats showed that subjects trained to stimuli less intense than the background noise level were marked by an exceptionally low level of avoidance responding with latencies shorter than 1.1 s, which was lower than expected from the probability of intertrial responses for this period of time. Due to this property of stimuli less intense than the background, the distributions of response latencies were moved to the right, in effect, prefrontal lesions influenced a greater part of latency distributions than in cats trained to stimuli more intense than the background.

Enhanced sensitivity to rare, emotion-irrelevant stimuli in females: neural correlates.

PubMed

Yuan, J J; Yang, J M; Chen, J; Meng, X X; Li, H

2010-09-15

Numerous studies showed enhanced sensitivity of females to emotional stimuli relative to males using multiple tasks. However, in the present study, two event-related potential (ERP) experiments targeting the impact of gender on rare stimulus processing both showed enhanced sensitivity of females to rare stimulus that is neutral, irrelevant to emotion. Subjects were required to press different keys for standard and rare pictures in Experiment 1, and to do nothing but to passively view the pictures in Experiment 2. Rare pictures elicited more intense pop-out effects in females, at both neuroelectrical (multiple levels of ERP analyses) and behavioral (response latencies and pop-out assessment) levels across experiments. Thus, females are equipped with enhanced sensitivity to rare, emotion-irrelevant stimuli relative to males, probably as a result of evolutionary adaptation. This effect is ought to be considered in studies that use an oddball paradigm. (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Seasonal changes in the cardiovascular, respiratory and metabolic responses to temperature and hypoxia in the bullfrog Rana catesbeiana.

PubMed

Rocha, P L; Branco, L G

1998-03-01

We assessed seasonal variations in the effects of temperature on hypoxia-induced alterations in the bullfrog Rana catesbeiana by measuring the heart rate, arterial blood pressure, breathing frequency, metabolic rate, blood gas levels, acid-base status and plasma glucose concentration. Regardless of the season, decreased body temperature was accompanied by a reduction in heart and breathing frequencies. Lower temperatures caused a significant decrease in arterial blood pressure during all four seasons. Hypoxia-induced changes in breathing frequency were proportional to body temperature and were more pronounced during winter, less so during spring and autumn and even smaller during summer. Season had no effect on the relationship between hypoxia and heart rate. At any temperature tested, the rate of oxygen consumption had a tendency to be highest during summer and lowest during winter, but the difference was significant only at 35 degrees C. The PaO2 and pH values showed no significant change during the year, but PaCO2 was almost twice as high during winter than in summer and spring, indicating increased plasma bicarbonate levels. Lower temperatures were accompanied by decreased plasma glucose levels, and this effect was greater during summer and smaller during autumn. Hypoxia-induced hyperglycaemia was influenced by temperature and season. During autumn and winter, plasma glucose level remained elevated regardless of temperature, probably to avoid dehydration and/or freezing. In winter, the bullfrog may be exposed not only to low temperatures but also to hypoxia. These animals show temperature-dependent responses that may be beneficial since at low body temperatures the set-points of most physiological responses to hypoxia are reduced, regardless of the season.

Immune responses to epstein-barr virus in atomic bomb survivors: Study of precursor frequency of cytotoxic lymphocytes and titer levels of anti-Epstein-Barr virus-related antibodies

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

Kusunoki, Yoichiro; Kyoizumi, Seishi; Saito, Mayumi

Precursor frequencies of cytotoxic lymphocytes to autologous Epstein-Barr virus-transformed B cells and serum titers of anti-Epstein-Barr virus-related antibodies were measured in 68 atomic bomb survivors to clarify the immune mechanism controlling Epstein-Barr virus infection. The precursor frequency was negatively correlated with the titer of anti-early antigen lgG, which is probably produced at the stage of viral reactivation. A positive correlation between the precursor frequency and titer of anti-Epstein-Barr virus-associated nuclear antigen antibody was also observed, indicating that the precursor frequency reflects the degree of in vivo destruction by T cells of the virus-infected cells. These results suggest that T-cell memorymore » specific to Epstein-Barr virus keeps the virus under control and that the precursor frequency assay is useful for the evaluation of immune responses to Epstein-Barr virus. However, no significant effect of atomic bomb radiation on the precursor frequency was observed in the present study, probably due to the limited number of participants. 24 refs., 4 figs., 2 tabs.« less

Stochastic analysis of epidemics on adaptive time varying networks

NASA Astrophysics Data System (ADS)

Kotnis, Bhushan; Kuri, Joy

2013-06-01

Many studies investigating the effect of human social connectivity structures (networks) and human behavioral adaptations on the spread of infectious diseases have assumed either a static connectivity structure or a network which adapts itself in response to the epidemic (adaptive networks). However, human social connections are inherently dynamic or time varying. Furthermore, the spread of many infectious diseases occur on a time scale comparable to the time scale of the evolving network structure. Here we aim to quantify the effect of human behavioral adaptations on the spread of asymptomatic infectious diseases on time varying networks. We perform a full stochastic analysis using a continuous time Markov chain approach for calculating the outbreak probability, mean epidemic duration, epidemic reemergence probability, etc. Additionally, we use mean-field theory for calculating epidemic thresholds. Theoretical predictions are verified using extensive simulations. Our studies have uncovered the existence of an “adaptive threshold,” i.e., when the ratio of susceptibility (or infectivity) rate to recovery rate is below the threshold value, adaptive behavior can prevent the epidemic. However, if it is above the threshold, no amount of behavioral adaptations can prevent the epidemic. Our analyses suggest that the interaction patterns of the infected population play a major role in sustaining the epidemic. Our results have implications on epidemic containment policies, as awareness campaigns and human behavioral responses can be effective only if the interaction levels of the infected populace are kept in check.

Prenatal choline supplementation increases sensitivity to time by reducing non-scalar sources of variance in adult temporal processing

PubMed Central

Cheng, Ruey-Kuang; Meck, Warren H.

2009-01-01

Choline supplementation of the maternal diet has a long-term facilitative effect on timing and temporal memory of the offspring. To further delineate the impact of early nutritional status on interval timing, we examined effects of prenatal-choline supplementation on the temporal sensitivity of adult (6 mo) male rats. Rats that were given sufficient choline in their chow (CON: 1.1 g/kg) or supplemental choline added to their drinking water (SUP: 3.5 g/kg) during embryonic days (ED) 12–17 were trained with a peak-interval procedure that was shifted among 75%, 50%, and 25% probabilities of reinforcement with transitions from 18s –> 36s –>72s temporal criteria. Prenatal-choline supplementation systematically sharpened interval-timing functions by reducing the associative/non-temporal response enhancing effects of reinforcement probability on the Start response threshold, thereby reducing non-scalar sources of variance in the left-hand portion of the Gaussian-shaped response functions. No effect was observed for the Stop response threshold as a function of any of these manipulations. In addition, independence of peak time and peak rate was demonstrated as a function of reinforcement probability for both prenatal-choline supplemented and control rats. Overall, these results suggest that prenatal-choline supplementation facilitates timing by reducing impulsive responding early in the interval, thereby improving the superimposition of peak functions for different temporal criteria. PMID:17996223

Level of UV-B radiation influences the effects of glyphosate-based herbicide on the spotted salamander.

PubMed

Levis, Nicholas A; Johnson, Jarrett R

2015-07-01

Glyphosate-based herbicides are the number one pesticide in the United States and are used commonly around the world. Understanding the affects of glyphosate-based herbicides on non-target wildlife, for example amphibians, is critical for evaluation of regulations pertaining to the use of such herbicides. Additionally, it is important to understand how variation in biotic and abiotic environmental conditions, such as UV-B light regime, could potentially affect how glyphosate-based herbicides interact with non-target species. This study used artificial pond mesocosms to identify the effects of generic glyphosate-based herbicide (GLY-4 Plus) on mortality, cellular immune response, body size, and morphological plasticity of larvae of the spotted salamander (Ambystoma maculatum) under conditions that reflect moderate (UV(M)) and low (UV(L)) UV-B light regimes. Survival within a given UV-B level was unaffected by herbicide presence or absence. However, when herbicide was present, survival varied between UV-B levels with higher survival in UV(M) conditions. Herbicide presence in the UV(M) treatments also decreased body size and reduced cellular immune response. In the UV(L) treatments, the presence of herbicide increased body size and affected tail morphology. Finally, in the absence of herbicide, body size and cellular immune response were higher in UV(M) treatments compared to UV(L) treatments. Thus, the effects of herbicide on salamander fitness were dependent on UV-B level. As anthropogenic habitat modifications continue to alter landscapes that contain amphibian breeding ponds, salamanders may increasingly find themselves in locations with reduced canopy cover and increased levels of UV light. Our findings suggest that the probability of surviving exposure to the glyphosate-based herbicide used in this study may be elevated in more open canopy ponds, but the effects on other components of fitness may be varied and unexpected.

Prediction of shock initiation thresholds and ignition probability of polymer-bonded explosives using mesoscale simulations

NASA Astrophysics Data System (ADS)

Kim, Seokpum; Wei, Yaochi; Horie, Yasuyuki; Zhou, Min

2018-05-01

The design of new materials requires establishment of macroscopic measures of material performance as functions of microstructure. Traditionally, this process has been an empirical endeavor. An approach to computationally predict the probabilistic ignition thresholds of polymer-bonded explosives (PBXs) using mesoscale simulations is developed. The simulations explicitly account for microstructure, constituent properties, and interfacial responses and capture processes responsible for the development of hotspots and damage. The specific mechanisms tracked include viscoelasticity, viscoplasticity, fracture, post-fracture contact, frictional heating, and heat conduction. The probabilistic analysis uses sets of statistically similar microstructure samples to directly mimic relevant experiments for quantification of statistical variations of material behavior due to inherent material heterogeneities. The particular thresholds and ignition probabilities predicted are expressed in James type and Walker-Wasley type relations, leading to the establishment of explicit analytical expressions for the ignition probability as function of loading. Specifically, the ignition thresholds corresponding to any given level of ignition probability and ignition probability maps are predicted for PBX 9404 for the loading regime of Up = 200-1200 m/s where Up is the particle speed. The predicted results are in good agreement with available experimental measurements. A parametric study also shows that binder properties can significantly affect the macroscopic ignition behavior of PBXs. The capability to computationally predict the macroscopic engineering material response relations out of material microstructures and basic constituent and interfacial properties lends itself to the design of new materials as well as the analysis of existing materials.

A Novel Methodology to Estimate the Treatment Effect in Presence of Highly Variable Placebo Response

PubMed Central

Gomeni, Roberto; Goyal, Navin; Bressolle, Françoise; Fava, Maurizio

2015-01-01

One of the main reasons for the inefficiency of multicenter randomized clinical trials (RCTs) in depression is the excessively high level of placebo response. The aim of this work was to propose a novel methodology to analyze RCTs based on the assumption that centers with high placebo response are less informative than the other centers for estimating the ‘true' treatment effect (TE). A linear mixed-effect modeling approach for repeated measures (MMRM) was used as a reference approach. The new method for estimating TE was based on a nonlinear longitudinal modeling of clinical scores (NLMMRM). NLMMRM estimates TE by associating a weighting factor to the data collected in each center. The weight was defined by the posterior probability of detecting a clinically relevant difference between active treatment and placebo at that center. Data from five RCTs in depression were used to compare the performance of MMRM with NLMMRM. The results of the analyses showed an average improvement of ~15% in the TE estimated with NLMMRM when the center effect was included in the analyses. Opposite results were observed with MMRM: TE estimate was reduced by ~4% when the center effect was considered as covariate in the analysis. The novel NLMMRM approach provides a tool for controlling the confounding effect of high placebo response, to increase signal detection and to provide a more reliable estimate of the ‘true' TE by controlling false negative results associated with excessively high placebo response. PMID:25895454

Ocean acidification effects on mesozooplankton community development: Results from a long-term mesocosm experiment.

PubMed

Algueró-Muñiz, María; Alvarez-Fernandez, Santiago; Thor, Peter; Bach, Lennart T; Esposito, Mario; Horn, Henriette G; Ecker, Ursula; Langer, Julia A F; Taucher, Jan; Malzahn, Arne M; Riebesell, Ulf; Boersma, Maarten

2017-01-01

Ocean acidification may affect zooplankton directly by decreasing in pH, as well as indirectly via trophic pathways, where changes in carbon availability or pH effects on primary producers may cascade up the food web thereby altering ecosystem functioning and community composition. Here, we present results from a mesocosm experiment carried out during 113 days in the Gullmar Fjord, Skagerrak coast of Sweden, studying plankton responses to predicted end-of-century pCO2 levels. We did not observe any pCO2 effect on the diversity of the mesozooplankton community, but a positive pCO2 effect on the total mesozooplankton abundance. Furthermore, we observed species-specific sensitivities to pCO2 in the two major groups in this experiment, copepods and hydromedusae. Also stage-specific pCO2 sensitivities were detected in copepods, with copepodites being the most responsive stage. Focusing on the most abundant species, Pseudocalanus acuspes, we observed that copepodites were significantly more abundant in the high-pCO2 treatment during most of the experiment, probably fuelled by phytoplankton community responses to high-pCO2 conditions. Physiological and reproductive output was analysed on P. acuspes females through two additional laboratory experiments, showing no pCO2 effect on females' condition nor on egg hatching. Overall, our results suggest that the Gullmar Fjord mesozooplankton community structure is not expected to change much under realistic end-of-century OA scenarios as used here. However, the positive pCO2 effect detected on mesozooplankton abundance could potentially affect biomass transfer to higher trophic levels in the future.

Ocean acidification effects on mesozooplankton community development: Results from a long-term mesocosm experiment

PubMed Central

Algueró-Muñiz, María; Alvarez-Fernandez, Santiago; Thor, Peter; Bach, Lennart T.; Esposito, Mario; Horn, Henriette G.; Ecker, Ursula; Langer, Julia A. F.; Taucher, Jan; Malzahn, Arne M.; Riebesell, Ulf; Boersma, Maarten

2017-01-01

Ocean acidification may affect zooplankton directly by decreasing in pH, as well as indirectly via trophic pathways, where changes in carbon availability or pH effects on primary producers may cascade up the food web thereby altering ecosystem functioning and community composition. Here, we present results from a mesocosm experiment carried out during 113 days in the Gullmar Fjord, Skagerrak coast of Sweden, studying plankton responses to predicted end-of-century pCO2 levels. We did not observe any pCO2 effect on the diversity of the mesozooplankton community, but a positive pCO2 effect on the total mesozooplankton abundance. Furthermore, we observed species-specific sensitivities to pCO2 in the two major groups in this experiment, copepods and hydromedusae. Also stage-specific pCO2 sensitivities were detected in copepods, with copepodites being the most responsive stage. Focusing on the most abundant species, Pseudocalanus acuspes, we observed that copepodites were significantly more abundant in the high-pCO2 treatment during most of the experiment, probably fuelled by phytoplankton community responses to high-pCO2 conditions. Physiological and reproductive output was analysed on P. acuspes females through two additional laboratory experiments, showing no pCO2 effect on females’ condition nor on egg hatching. Overall, our results suggest that the Gullmar Fjord mesozooplankton community structure is not expected to change much under realistic end-of-century OA scenarios as used here. However, the positive pCO2 effect detected on mesozooplankton abundance could potentially affect biomass transfer to higher trophic levels in the future. PMID:28410436

Variation, Repetition, And Choice

PubMed Central

Abreu-Rodrigues, Josele; Lattal, Kennon A; dos Santos, Cristiano V; Matos, Ricardo A

2005-01-01

Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence. PMID:15828592

Predicting dynamic range and intensity discrimination for electrical pulse-train stimuli using a stochastic auditory nerve model: the effects of stimulus noise.

PubMed

Xu, Yifang; Collins, Leslie M

2005-06-01

This work investigates dynamic range and intensity discrimination for electrical pulse-train stimuli that are modulated by noise using a stochastic auditory nerve model. Based on a hypothesized monotonic relationship between loudness and the number of spikes elicited by a stimulus, theoretical prediction of the uncomfortable level has previously been determined by comparing spike counts to a fixed threshold, Nucl. However, no specific rule for determining Nucl has been suggested. Our work determines the uncomfortable level based on the excitation pattern of the neural response in a normal ear. The number of fibers corresponding to the portion of the basilar membrane driven by a stimulus at an uncomfortable level in a normal ear is related to Nucl at an uncomfortable level of the electrical stimulus. Intensity discrimination limens are predicted using signal detection theory via the probability mass function of the neural response and via experimental simulations. The results show that the uncomfortable level for pulse-train stimuli increases slightly as noise level increases. Combining this with our previous threshold predictions, we hypothesize that the dynamic range for noise-modulated pulse-train stimuli should increase with additive noise. However, since our predictions indicate that intensity discrimination under noise degrades, overall intensity coding performance may not improve significantly.

Effects of Exposure to the Sound from Seismic Airguns on Pallid Sturgeon and Paddlefish

PubMed Central

Gross, Jackson A.; Carlson, Thomas J.; Skalski, John; Young, John V.; Hawkins, Anthony D.; Zeddies, David

2016-01-01

This study examined the effects of exposure to a single acoustic pulse from a seismic airgun array on caged endangered pallid sturgeon (Scaphirhynchus albus) and on paddlefish (Polyodon spathula) in Lake Sakakawea (North Dakota, USA). The experiment was designed to detect the onset of physiological responses including minor to mortal injuries. Experimental fish were held in cages as close as 1 to 3 m from the guns where peak negative sound pressure levels (Peak- SPL) reached 231 dB re 1 μPa (205 dB re 1 μPa2·s sound exposure level [SEL]). Additional cages were placed at greater distances in an attempt to develop a dose-response relationship. Treatment and control fish were then monitored for seven days, euthanized, and necropsied to determine injuries. Necropsy results indicated that the probability of delayed mortality associated with pulse pressure following the seven day monitoring period was the same for exposed and control fish of both species. Exposure to a single pulse from a small air gun array (10,160 cm3) was not lethal for pallid sturgeon and paddlefish. However, the risks from exposure to multiple sounds and to sound exposure levels that exceed those reported here remain to be examined. PMID:27505029

Effects of Exposure to the Sound from Seismic Airguns on Pallid Sturgeon and Paddlefish.

PubMed

Popper, Arthur N; Gross, Jackson A; Carlson, Thomas J; Skalski, John; Young, John V; Hawkins, Anthony D; Zeddies, David

2016-01-01

This study examined the effects of exposure to a single acoustic pulse from a seismic airgun array on caged endangered pallid sturgeon (Scaphirhynchus albus) and on paddlefish (Polyodon spathula) in Lake Sakakawea (North Dakota, USA). The experiment was designed to detect the onset of physiological responses including minor to mortal injuries. Experimental fish were held in cages as close as 1 to 3 m from the guns where peak negative sound pressure levels (Peak- SPL) reached 231 dB re 1 μPa (205 dB re 1 μPa2·s sound exposure level [SEL]). Additional cages were placed at greater distances in an attempt to develop a dose-response relationship. Treatment and control fish were then monitored for seven days, euthanized, and necropsied to determine injuries. Necropsy results indicated that the probability of delayed mortality associated with pulse pressure following the seven day monitoring period was the same for exposed and control fish of both species. Exposure to a single pulse from a small air gun array (10,160 cm3) was not lethal for pallid sturgeon and paddlefish. However, the risks from exposure to multiple sounds and to sound exposure levels that exceed those reported here remain to be examined.

Temperatures in Excess of Critical Thresholds Threaten Nestling Growth and Survival in A Rapidly-Warming Arid Savanna: A Study of Common Fiscals

PubMed Central

Cunningham, Susan J.; Martin, Rowan O.; Hojem, Carryn L.

2013-01-01

Frequency, duration, and intensity of hot-weather events are all predicted to increase with climate warming. Despite this, mechanisms by which temperature increases affect individual fitness and drive population-level changes are poorly understood. We investigated the link between daily maximum air temperature (tmax) and breeding success of Kalahari common fiscals (Lanius collaris) in terms of the daily effect on nestling body-mass gain, and the cumulative effect on size and age of fledglings. High tmax reduced mass gain of younger, but not older nestlings and average nestling-period tmax did not affect fledgling size. Instead, the frequency with which tmax exceeded critical thresholds (tcrits) significantly reduced fledging body mass (tcrit = 33°C) and tarsus length (tcrit = 37°C), as well as delaying fledging (tcrit = 35°C). Nest failure risk was 4.2% per day therefore delays reduced fledging probability. Smaller size at fledging often correlates with reduced lifetime fitness and might also underlie documented adult body-size reductions in desert birds in relation to climate warming. Temperature thresholds above which organisms incur fitness costs are probably common, as physiological responses to temperature are non-linear. Understanding the shape of the relationship between temperature and fitness has implications for our ability to predict species’ responses to climate change. PMID:24040296

Acute Exposure to Worst-Case Concentrations of Amitraz Does Not Affect Honey Bee Learning, Short-Term Memory, or Hemolymph Octopamine Levels.

PubMed

Rix, Rachel R; Christopher Cutler, G

2017-02-01

Amitraz, an acaricide used to treat Varroa destructor Anderson & Trueman, is one of the most commonly detected pesticides in honey bee (Apis mellifera L.) hives. Acaricides sometimes negatively impact honey bee cognition, but potential effects of amitraz on honey bee learning have been rarely studied. We topically exposed foragers to 95th percentile field-relevant levels of amitraz and, 24 h later, tested the ability of bees to associate a sucrose reward with a conditioned odor (learning response) using the proboscis extension response (PER). We then tested the ability of the bees to retain this memory 1 h and 2 h post-conditioning. Because amitraz is thought to affect octopamine metabolism in honey bees, and because octopamine is directly related to honey bee learning and memory, we also examined effects of exposure to amitraz on octopamine levels in honey bee hemolymph. We found that acute exposure to 95th percentile doses of amitraz had no impact on honey bee learning or short-term memory as measured by PER. Concentrations of octopamine in hemolymph from our low amitraz treatment were 1.4-fold higher than control levels, but other treatments had no effect. Our results from worst-case acute exposure experiments with worker bees in the laboratory suggest that typical field-relevant (within hive) exposures to amitraz probably have little effect on honey bee learning and memory. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cancer mortality among coke oven workers.

PubMed Central

Redmond, C K

1983-01-01

The OSHA standard for coke oven emissions, which went into effect in January 1977, sets a permissible exposure limit to coke oven emissions of 150 micrograms/m3 benzene-soluble fraction of total particulate matter (BSFTPM). Review of the epidemiologic evidence for the standard indicates an excess relative risk for lung cancer as high as 16-fold in topside coke oven workers with 15 years of exposure or more. There is also evidence for a consistent dose-response relationship in lung cancer mortality when duration and location of employment at the coke ovens are considered. Dose-response models fitted to these same data indicate that, while excess risks may still occur under the OSHA standard, the predicted levels of increased relative risk would be about 30-50% if a linear dose-response model is assumed and 3-7% if a quadratic model is assumed. Lung cancer mortality data for other steelworkers suggest the predicted excess risk has probably been somewhat overestimated, but lack of information on important confounding factors limits further dose-response analysis. PMID:6653539

Seed and vegetative production of shrubs and growth of understory conifer regeneration

USGS Publications Warehouse

Wender, B.; Harrington, C.; Tappeiner, J. C.

2004-01-01

We observed flower and fruit production for nine understory shrub species in western Washington and Oregon and examined the relationships between shrub reproductive output and plant size, plant age, site factors, and overstory density to determine the factors that control flowering or fruiting in understory shrubs. In Washington, 50 or more shrubs or microplots (for rhizomatous species) were sampled for each of eight species. The variables examined were more useful for explaining abundance of flowers or fruit on shrubs than they were for explaining the probability that a shrub would produce flowers or fruit. Plant size was consistently the most useful predictor of flower/fruit abundance in all species; plant age was also a good predictor of abundance and was strongly correlated with plant size. Site variables (e.g., slope) and overstory competition variables (e.g., presence/absence of a canopy gap) also helped explain flower/fruit abundance for some species. At two Oregon sites, the responses of five species to four levels of thinning were observed for 2-4 yr (15 shrubs or microplots per treatment per year). Thinning increased the probability and abundance of flowering/fruiting for two species, had no effect on one species, and responses for two other species were positive but inconsistent between sites or from year to year. We believe reducing overstory density or creating canopy gaps may be useful tools for enhancing shrub size and vigor, thus, increasing the probability and abundance of fruiting in some understory shrub species.

Flower and fruit production of understory shrubs in western Washington and Oregon

USGS Publications Warehouse

Wender, B.; Harrington, C.; Tappeiner, J. C.

2004-01-01

We observed flower and fruit production for nine understory shrub species in western Washington and Oregon and examined the relationships between shrub reproductive output and plant size, plant age, site factors, and overstory density to determine the factors that control flowering or fruiting in understory shrubs. In Washington, 50 or more shrubs or microplots (for rhizomatous species) were sampled for each of eight species. The variables examined were more useful for explaining abundance of flowers or fruit on shrubs than they were for explaining the probability that a shrub would produce flowers or fruit. Plant size was consistently the most useful predictor of flower/fruit abundance in all species; plant age was also a good predictor of abundance and was strongly correlated with plant size. Site variables (e.g., slope) and overstory competition variables (e.g., presence/absence of a canopy gap) also helped explain flower/fruit abundance for some species. At two Oregon sites, the responses of five species to four levels of thinning were observed for 2-4 yr (15 shrubs or microplots per treatment per year). Thinning increased the probability and abundance of flowering/fruiting for two species, had no effect on one species, and responses for two other species were positive but inconsistent between sites or from year to year. We believe reducing overstory density or creating canopy gaps may be useful tools for enhancing shrub size and vigor, thus, increasing the probability and abundance of fruiting in some understory shrub species.

Differential Responses to Woodland Character and Landscape Context by Cryptic Bats in Urban Environments

PubMed Central

Lintott, Paul R.; Bunnefeld, Nils; Minderman, Jeroen; Fuentes-Montemayor, Elisa; Mayhew, Rebekah J.; Olley, Lena; Park, Kirsty J.

2015-01-01

Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes. PMID:25978034

Differential responses to woodland character and landscape context by cryptic bats in urban environments.

PubMed

Lintott, Paul R; Bunnefeld, Nils; Minderman, Jeroen; Fuentes-Montemayor, Elisa; Mayhew, Rebekah J; Olley, Lena; Park, Kirsty J

2015-01-01

Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes.

Cardiovascular responses to railway noise during sleep in young and middle-aged adults.

PubMed

Tassi, Patricia; Saremi, Mahnaz; Schimchowitsch, Sarah; Eschenlauer, Arnaud; Rohmer, Odile; Muzet, Alain

2010-03-01

The aim of this study was to investigate the effects of nocturnal railway noise on cardiovascular reactivity in young (25.8 +/- 2.6 years) and middle-aged (52.2 +/- 2.5 years) adults during sleep. Thirty-eight subjects slept three nights in the laboratory at 1-week interval. They were exposed to 48 randomized pass-bys of Freight, Passenger and Automotive trains either at an 8-h equivalent sound level of 40 dBA (Moderate) and 50 dBA (High) or at a silent Control night. Heart rate response (HRR), heart response amplitude (HRA), heart response latency (HRL) and finger pulse response (FPR), finger pulse amplitude (FPA) and finger pulse latency (FPL) were recorded to measure cardiovascular reactivity after each noise onset and for time-matched pseudo-noises in the control condition. Results show that Freight trains produced the highest cardiac response (increased HRR, HRA and HRL) compared to Passenger and Automotive. But the vascular response was similar whatever the type of train. Juniors exhibited an increased HRR and HRA as compared to seniors, but there was no age difference on vasoconstriction, except a shorter FPL in seniors. Noise level produced dose-dependent effects on all the cardiovascular indices. Sleep stage at noise occurrence was ineffective for cardiac response, but FPA was reduced when noise occurred during REM sleep. In conclusion, our study is in favor of an important impact of nocturnal railway noise on the cardiovascular system of sleeping subjects. In the limit of the samples studied, Freight trains are the most harmful, probably more because of their special length (duration) than because of their speed (rise time).

Effects of airborne pollutants on mucociliary clearance.

PubMed

Wolff, R K

1986-04-01

The mucociliary clearance system is a first line of defense against inhaled agents, and so its compromise can adversely affect health. The purpose of this paper is to provide a review of data on the effect of in vivo air pollutant exposures on the clearance of test particles from airways. Data from both animals and humans are compared whenever possible, so that estimates of human health effects may be made. Mechanisms of action are also discussed, presenting the view that for low level exposures, changes in secretions are probably responsible for most observed changes in clearance. The pollutants pertinent to this review are those that are common in the environment and most likely to have impacts on large numbers of people: sulfur oxides, sulfuric acid mist, O3, NO2, particulates, diesel exhaust, and cigarette smoke.

Plant-based immunocontraceptive control of wildlife--"potentials, limitations, and possums".

PubMed

Polkinghorne, Ian; Hamerli, Denes; Cowan, Phil; Duckworth, Janine

2005-03-07

Possums (Trichosurus vulpecula), originally introduced from Australia, are spread over 90% of New Zealand and cause major economic and environmental damage. Immunocontraception has been suggested as a humane means to control them. Marsupial-specific reproductive antigens expressed at high levels in edible transgenic plant tissue might provide a safe, effective, and cheap oral delivery bait for immunocontraceptive control. As proof of concept, female possums vaccinated with immunocontraceptive antigens showed reduced fertility, and possums fed with potato-expressed heat labile toxin-B (LT-B) had mucosal and systemic immune responses to the antigen. This demonstrated that immunocontraception was effective in possums and that oral delivery in edible plant material might be possible. Nuclear transformation with reporter genes showed that transgenic carrot roots accumulate high levels of foreign protein in edible tissues, indicating their potential as a delivery vector. However, prior to attempts at large scale production, more effective immunocontraceptive antigen-adjuvant formulations are probably required before plant-based immunocontraception can become a major tool for immunocontraceptive control of overabundant vertebrate pests.

Patterns of Symptomatic Recovery in Psychotherapy.

ERIC Educational Resources Information Center

Kopta, Stephen Mark; And Others

1994-01-01

Used psychotherapy dosage model in which effect was probability of recovery to compare treatment response rates for psychological symptoms. Administered symptom checklists to 854 psychotherapy outpatients at intake and during treatment. Chronic distress symptoms demonstrated fastest average response rate, whereas characterological symptoms…

On the Effects of Signaling Reinforcer Probability and Magnitude in Delayed Matching to Sample

ERIC Educational Resources Information Center

Brown, Glenn S.; White, K. Geoffrey

2005-01-01

Two experiments examined whether postsample signals of reinforcer probability or magnitude affected the accuracy of delayed matching to sample in pigeons. On each trial, red or green choice responses that matched red or green stimuli seen shortly before a variable retention interval were reinforced with wheat access. In Experiment 1, the…

Radiological incident preparedness: planning at the local level.

PubMed

Tan, Clive M; Barnett, Daniel J; Stolz, Adam J; Links, Jonathan M

2011-03-01

Radiological terrorism has been recognized as a probable scenario with high impact. Radiological preparedness planning at the federal and state levels has been encouraging, but translating complex doctrines into operational readiness at the local level has proved challenging. Based on the authors' experience with radiological response planning for the City of Baltimore, this article describes an integrated approach to municipal-level radiological emergency preparedness planning, provides information on resources that are useful for radiological preparedness planning, and recommends a step-by-step process toward developing the plan with relevant examples from the experience in Baltimore. Local governmental agencies constitute the first line of response and are critical to the success of the operation. This article is intended as a starting framework for local governmental efforts toward developing a response plan for radiological incidents in their communities.

An Experimental Test of Competition among Mice, Chipmunks, and Squirrels in Deciduous Forest Fragments

PubMed Central

Brunner, Jesse L.; Duerr, Shannon; Keesing, Felicia; Killilea, Mary; Vuong, Holly; Ostfeld, Richard S.

2013-01-01

Mixed hardwood forests of the northeast United States support a guild of granivorous/omnivorous rodents including gray squirrels (Sciurus carolinensis), eastern chipmunks (Tamias striatus), and white-footed mice (Peromyscus leucopus). These species coincide geographically, co-occur locally, and consume similar food resources. Despite their idiosyncratic responses to landscape and patch variables, patch occupancy models suggest that competition may influence their respective distributions and abundances, and accordingly their influence on the rest of the forest community. Experimental studies, however, are wanting. We present the result of a large-scale experiment in which we removed white-footed mice or gray squirrels from small, isolated forest fragments in Dutchess County, New York, and added these mammals to other fragments in order to alter the abundance of these two species. We then used mark–recapture analyses to quantify the population-level and individual-level effects on resident mice, squirrels, and chipmunks. Overall, we found little evidence of competition. There were essentially no within-season numerical responses to changes in the abundance of putative competitors. Moreover, while individual-level responses (apparent survival and capture probability) did vary with competitor densities in some models, these effects were often better explained by site-specific parameters and were restricted to few of the 19 sites we studied. With only weak or nonexistent competition among these three common rodent species, we expect their patterns of habitat occupancy and population dynamics to be largely independent of one another. PMID:23824654

Substance P contributes to rapidly adapting receptor responses to pulmonary venous congestion in rabbits.

PubMed

Bonham, A C; Kott, K S; Ravi, K; Kappagoda, C T; Joad, J P

1996-05-15

1. This study tested the hypothesis that substance P stimulates rapidly adapting receptors (RARs), contributes to the increase in RAR activity produced by mild pulmonary congestion, and evokes an augmented response from RARs when combined with near-threshold levels of pulmonary congestion. 2. RAR activity, peak tracheal pressure, arterial blood pressure and left atrial pressure were measured in paralysed, anaesthetized and ventilated rabbits. Substance P was given i.v. in one-half log incremental doses to a maximum of 3 micrograms kg-1. Mild pulmonary congestion was produced by inflating a balloon in the left atrium to increase left atrial pressure by 5 mmHg. Near-threshold levels of pulmonary congestion were produced by increasing left atrial pressure by 2 mmHg. 3. Substance P produced dose-dependent increases in RAR activity. The highest dose given increased the activity from 1.3 +/- 0.5 to 11.0 +/- 3.1 impulses bin-1. Increases in left atrial pressure of 5 mmHg increased RAR activity from 3.8 +/- 1.4 to 14.7 +/- 3.9 impulses bin-1. Blockade of NK1 receptors with CP 96345 significantly attenuated RAR responses to substance P and to mild pulmonary congestion. 4. Doses of substance P, which alone had no effect, stimulated the RARs when delivered during near-threshold levels of pulmonary congestion. 5. The findings suggest that substance P augments the stimulatory effect of mild pulmonary congestion on RAR activity, most probably by enhancing hydraulically induced microvascular leak.

Flooding Risk Assessment for the Region of Neva Bay and Saint-Petersburg

NASA Astrophysics Data System (ADS)

Koch, A.; Nikitin, O.

2006-12-01

Sea level evaluations in the region of Saint-Petersburg, Russia, well known as "Neva Flooding" is the great scientific problem. This process has been investigated by various researchers for many tens of years. But they have not come to consideration regarding its nature. There are numerous factors responsible to extreme sea level rise in this location, and it is impossible to assess properly their individual and combine effect. In this Abstract the approach and primary results of the work are given. We tried to solve the task of flooding risk assessment in Neva Bay and Saint-Petersburg from the probability theory point of view. Sea level rise is considered as a stochastic process. To assess probable risk of a flooding the statistical game theory is used. There are two players in common statistical game. Each of them has the set of strategies that are used in the game. Who fails must pay. In our case one player is the Nature and the other is the Oceanographer, he chooses certain strategy to avoid flood consequences or minimize them. The Nature is the irrational and unpredictable player who has infinity set of strategies or certain conditions. But the choose of a condition is the subject of Monte Carlo model, and the Oceanographer can obtain some information about this model or Nature's behavior, that determined by the probability distribution of Nature's conditions. The main Oceanographer task is to take an optimal policy for various coastal objects regarding their protection characteristics, so that from one hand do not lose in quality and, from the other hand, do not raise its price. The policies are found out depending on some parameter that determined by the Nature condition. In our task this parameter is the evaluation of sea level near the coastal object. For the Nature condition we assumed the integral atmospheric characteristic that most completely expresses the synoptic state responsible for flooding. This characteristic includes all the cyclone parameters: its depth, size, shape, maximal pressure gradient, its direction and velocity, and the wind speed and direction. Regarding all these characteristics we calibrated all the cyclones using atmospheric reanalysis for 1979 now days and placed each cyclone near certain level evaluation using in-situ observations. This allows to predict certain man policies regarding flooding protection depending on cyclone type.

Acute serotonin depletion releases motivated inhibition of response vigour.

PubMed

den Ouden, Hanneke E M; Swart, Jennifer C; Schmidt, Kristin; Fekkes, Durk; Geurts, Dirk E M; Cools, Roshan

2015-04-01

The neurotransmitter serotonin has long been implicated in the motivational control of behaviour. Recent theories propose that the role of serotonin can be understood in terms of an interaction between a motivational and a behavioural activation axis. Experimental support for these ideas, however, has been mixed. In the current study, we aimed to investigate the role of serotonin (5HT) in behavioural vigour as a function of incentive motivation. We employed dietary acute tryptophan depletion (ATD) to lower the 5HT precursor tryptophan during the performance of a speeded visual discrimination task. Feedback valence and feedback probability were manipulated independently and cued prior to target onset. On feedback trials, fast correct responses led to either reward or avoidance of punishment, while slow or incorrect responses led to reward omission or punishment. We show that behavioural responding is inhibited under high incentive motivation (i.e. high-feedback probability) at baseline 5HT levels and that lowering these leads to behavioural disinhibition, while leaving accuracy unaffected. Surprisingly, there were no differential effects of motivational valence, with 5HT depletion releasing behavioural inhibition under both appetitive and aversive motivation. Our findings extend current theories on the role of 5HT in behavioural inhibition by showing that reductions in serotonin lead to increased behavioural vigour only if there is a motivational drive to inhibit behaviour at baseline.

New normative standards of conditional reasoning and the dual-source model

PubMed Central

Singmann, Henrik; Klauer, Karl Christoph; Over, David

2014-01-01

There has been a major shift in research on human reasoning toward Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998) for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer and Kleiter, 2005, 2010) exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer et al., 2010) is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches) and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task. PMID:24860516

New normative standards of conditional reasoning and the dual-source model.

PubMed

Singmann, Henrik; Klauer, Karl Christoph; Over, David

2014-01-01

There has been a major shift in research on human reasoning toward Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998) for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer and Kleiter, 2005, 2010) exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer et al., 2010) is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches) and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task.

Microdosimetric Analysis Confirms Similar Biological Effectiveness of External Exposure to Gamma-Rays and Internal Exposure to 137Cs, 134Cs, and 131I

PubMed Central

Sato, Tatsuhiko; Manabe, Kentaro; Hamada, Nobuyuki

2014-01-01

The risk of internal exposure to 137Cs, 134Cs, and 131I is of great public concern after the accident at the Fukushima-Daiichi nuclear power plant. The relative biological effectiveness (RBE, defined herein as effectiveness of internal exposure relative to the external exposure to γ-rays) is occasionally believed to be much greater than unity due to insufficient discussions on the difference of their microdosimetric profiles. We therefore performed a Monte Carlo particle transport simulation in ideally aligned cell systems to calculate the probability densities of absorbed doses in subcellular and intranuclear scales for internal exposures to electrons emitted from 137Cs, 134Cs, and 131I, as well as the external exposure to 662 keV photons. The RBE due to the inhomogeneous radioactive isotope (RI) distribution in subcellular structures and the high ionization density around the particle trajectories was then derived from the calculated microdosimetric probability density. The RBE for the bystander effect was also estimated from the probability density, considering its non-linear dose response. The RBE due to the high ionization density and that for the bystander effect were very close to 1, because the microdosimetric probability densities were nearly identical between the internal exposures and the external exposure from the 662 keV photons. On the other hand, the RBE due to the RI inhomogeneity largely depended on the intranuclear RI concentration and cell size, but their maximum possible RBE was only 1.04 even under conservative assumptions. Thus, it can be concluded from the microdosimetric viewpoint that the risk from internal exposures to 137Cs, 134Cs, and 131I should be nearly equivalent to that of external exposure to γ-rays at the same absorbed dose level, as suggested in the current recommendations of the International Commission on Radiological Protection. PMID:24919099

Prospects for pro-environmental protein consumption in Europe: Cultural, culinary, economic and psychological factors.

PubMed

de Boer, Joop; Aiking, Harry

2018-02-01

The current ratio between plant and animal protein in the Western diet is causing serious threats to both public health and the environment. Healthy, pro-environmental protein consumption requires a transition to a diet with more plant protein and considerably less animal protein. The present paper focuses on the prospects of this transition by analyzing consumer responses to some key options in the context of regional differences across Europe. The aim is to assess how responses to the options might be shaped by 1) cultural, culinary and economic spatial gradients (including GDP per capita) at regional level and 2) differences in environmental friendly behavior and gender at individual level. The study, covering all EU members in 2012, compares regional level statistics (food supply data) with individual level statistics (consumer survey data) and vice-versa. The south-north latitude gradient showed a decreasing trend in vegetable and pulse protein supplies and, in parallel, a decreasing trend in positive consumer responses to the key options, probably due to differences in meal experiences. The west-east longitude gradient showed decreasing levels of animal protein supplies and GDP per capita. Individuals' willingness to do something positive for the environment and their gender played a weak but consistent role in the responses. To effectively stimulate diet changes, it is important to seek ways in which culinary and environmental aspects can complement each other and to ensure that diet changes do not depend solely on individual decisions but become an integral part of regional social processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clinical utility of the ARCHITECT HCV Ag assay for early treatment monitoring in patients with chronic hepatitis C genotype 1 infection.

PubMed

Vermehren, Johannes; Susser, Simone; Berger, Annemarie; Perner, Dany; Peiffer, Kai-Henrik; Allwinn, Regina; Zeuzem, Stefan; Sarrazin, Christoph

2012-09-01

Virologic response-monitoring is essential for determining therapy duration in patients with chronic hepatitis C virus (HCV) infection. This is usually performed using highly sensitive HCV-RNA assays. However, HCV-RNA assays are time-consuming, expensive and require highly trained personnel. Quantitative determination of HCV core-antigen (HCVAg) levels may be used to supplement treatment monitoring. The clinical utility of the ARCHITECT HCV Ag assay (Abbott Diagnostics) for response-guided therapy was investigated. We analyzed serum from 160 patients with HCV genotype 1 infection who had been treated with peg-interferon alfa-2b/ribavirin. HCVAg levels were determined at baseline, weeks 1, 2, 4 and 12. HCVAg levels were compared to those obtained with HCV-RNA assays: VERSANT HCV Quantitative 3.0 (bDNA) and Qualitative (TMA, both Siemens Healthcare) assay and the Abbott RealTime HCV assay (ART; Abbott Diagnostics). Baseline HCVAg levels correlated well with HCV-RNA as assessed by bDNA (r=0.91; p<0.0001) and ART (r=0.92; p<0.0001), respectively. Patients with undetectable HCVAg levels at week 1 had a 90.9% probability (positive predictive value) to achieve a rapid virologic response (HCV-RNA undetectable at week 4) based on TMA and 86.4% based on ART, respectively. Patients with less than 1 log(10) reduction in HCVAg between baseline and week 12 had a 90% probability (negative predictive value) to achieve a nonresponse (<2 log(10) decline in HCV-RNA between baseline and week 12) based on bDNA and 100% based on ART, respectively. Determination of HCVAg may be useful for antiviral response-monitoring in patients with HCV genotype 1 infection. Copyright © 2012 Elsevier B.V. All rights reserved.

R- and S-citalopram concentrations have differential effects on neuropsychiatric scores in elders with dementia and agitation.

PubMed

Ho, Thang; Pollock, Bruce G; Mulsant, Benoit H; Schantz, Oliver; Devanand, Devangere P; Mintzer, Jacobo E; Porsteinsson, Anton P; Schneider, Lon S; Weintraub, Daniel; Yesavage, Jerome; Drye, Lea T; Munro, Cynthia A; Shade, David M; Lyketsos, Constantine; Bies, Robert

2016-09-01

The aim was to determine the relationship between (R) and (S)-citalopram enantiomer exposure (AUC(0,24 h)) and therapeutic response in agitated individuals greater than 60 years old with Alzheimer's dementia (AD). Citalopram enantiomer exposures (AUC(0,24 h)) derived from an established population pharmacokinetic analysis were utilized to explore the relationship between (R)- and (S)-citalopram area under the curve (AUC(0,24 )) and Mini-Mental State Examination (MMSE), Neurobehavioural Rating Scale-Agitation Subscale (NBRS-A), modified Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (mADCS-CGIC) and Neuropsychiatric Inventory Agitation subscale (NPIA) scores. Time dependent changes in these scores (disease progression) were accounted for prior to exploring the exposure effect relationship for each enantiomer. These relationships were evaluated using a non-linear-mixed effects modelling approach as implemented in nonmem v7.3. (S)-AUC(0,24 h) and (R)-AUC(0,24 h) each contributed to improvement in NBRS-A scores (k3(R) -0.502; k4(S) -0.712) as did time in treatment. However, increasing (R)-AUC(0,24 h) decreased the probability of patient response (maximum Δ -0.182%/AUC(0,24 h)) based on the CGIC while (S)-AUC(0,24 h) improved the probability of response (maximum Δ 0.112%/AUC(0,24 h)). (R)-AUC(0,24 h) was also associated with worsening in MMSE scores (-0.5 points). Our results suggest that citalopram enantiomers contributed differentially to treatment outcomes. (R)-citalopram accounted for a greater proportion of the adverse consequences associated with racemic citalopram treatment in patients with AD including a decreased probability of treatment response as measured by the CGIC and a reduction in MMSE scores. The S-enantiomer was associated with increased probability of response based on the CGIC. © 2016 The British Pharmacological Society.

Plasmatic endothelin-1 levels in hyperthyroid patients before and after antithyroid therapy.

PubMed

Cesareo, R; Tarabuso, A; Di Benedetto, M; Lacerna, F; Reda, G

2000-03-01

The Endothelin-1 (ET-1) is a powerful vasoconstrictor peptide produced by endothelial cells in many vascular diseases probably as a response to vessel damage. In hyperthyroidism as in other endocrinological diseases elevated ET-1 plasma levels have been found. The effect of antithyroid therapy on ET-1 plasmatic levels was evaluated by measuring ET-1 plasma levels before and 2 and 6 months after treatment with methimazole in 14 patients affected by hyperthyroidism. The hyperthyroid patients had significantly higher ET-1 levels than the controls (18.85 +/- 5.7 vs 10.9 +/- 2.1 pg/ml), while after treatment no difference was found. The ET-1 plasma levels of hyperthyroid patients correlated closely with the raised thyroid metabolic activity independently of its cause. It is possible that the increased ET-1 levels in hyperthyroid patients are the expression of blood vessel damage caused by high thyroid hormone levels. Moreover the results of this study could suggest that, in future, ET-1 plasmatic levels might be considered as a functional thyroid index in hyperthyroid diseases.

Future Climate CO2 Levels Mitigate Stress Impact on Plants: Increased Defense or Decreased Challenge?

PubMed Central

AbdElgawad, Hamada; Zinta, Gaurav; Beemster, Gerrit T. S.; Janssens, Ivan A.; Asard, Han

2016-01-01

Elevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect), and is observed to mitigate abiotic stress impact. Although, the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis). A systematic literature analysis, including “all” papers [Web of Science (WoS)-cited], addressing elevated CO2 effects on abiotic stress responses and antioxidants (105 papers), confirms the frequent occurrence of the stress mitigation effect. However, it also demonstrates that, in stress conditions, elevated CO2 is reported to increase antioxidants, only in about 22% of the observations (e.g., for polyphenols, peroxidases, superoxide dismutase, monodehydroascorbate reductase). In most observations, under stress and elevated CO2 the levels of key antioxidants and antioxidant enzymes are reported to remain unchanged (50%, e.g., ascorbate peroxidase, catalase, ascorbate), or even decreased (28%, e.g., glutathione peroxidase). Moreover, increases in antioxidants are not specific for a species group, growth facility, or stress type. It seems therefore unlikely that increased antioxidant defense is the major mechanism underlying CO2-mediated stress impact mitigation. Alternative processes, probably decreasing the oxidative challenge by reducing ROS production (e.g., photorespiration), are therefore likely to play important roles in elevated CO2 (relaxation hypothesis). Such parameters are however rarely investigated in connection with abiotic stress relief. Understanding the effect of elevated CO2 on plant growth and stress responses is imperative to understand the impact of climate changes on plant productivity. PMID:27200030

INTERACTION OF BENZO(A)PYRENE DIOL EPOXIDE WITH SVAO MINICHROMOSOMES

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

Gamper, Howard B.; Yokota, Hisao A.; Bartholomew, James C.

SV40 minichromosomes were reacted with (+)7{beta},8{alpha}-dihydroxy-9{alpha},10{alpha}-epoxy- 7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide). Low levels of modification (< 5 DNA adducts/minichromosome) did not detectably alter the structure of the minichromosomes but high levels (> 200 DNA adducts/minichromosome) led to extensive fragmentation. Relative to naked SV40 DNA BaP diol epoxide induced alkylation and strand scission of minichromosomal DNA was reduced or enhanced by factors of 1.5 and 2.0, respectively. The reduction in covalent binding was attributed to the presence of histones, which competed with DNA for the hydrocarbon and reduced the probability of BaP diol epoxide intercalation by tightening the helix. The enhancement ofmore » strand scission was probably due to the catalytic effect of histones on the rate of S-elimination at apurinic sites, although an altered adduct profile or the presence of a repair endonuclease were not excluded. Staphylococcal nuclease digestion indicated that BaP dial epoxide randomly alkylated the minichromosomal DNA. This is in contrast to studies with cellular chromatin where internucleosomal DNA was preferentially modified. Differences in the minichromosomal protein complement were responsible for this altered susceptibility.« less

Male-induced short oestrous and ovarian cycles in sheep and goats: a working hypothesis.

PubMed

Chemineau, Philippe; Pellicer-Rubio, Maria-Theresa; Lassoued, Narjess; Khaldi, Gley; Monniaux, Danielle

2006-01-01

The existence of short ovulatory cycles (5-day duration) after the first male-induced ovulations in anovulatory ewes and goats, associated or not with the appearance of oestrous behaviour, is the origin of the two-peak abnormal distribution of parturitions after the "male effect". We propose here a working hypothesis to explain the presence of these short cycles. The male-effect is efficient during anoestrus, when follicles contain granulosa cells of lower quality than during the breeding season. They generate corpora lutea (CL) with a lower proportion of large luteal cells compared to small cells, which secrete less progesterone, compared to what is observed in the breeding season cycle. This is probably not sufficient to block prostaglandin synthesis in the endometrial cells of the uterus at the time when the responsiveness to prostaglandins of the new-formed CL is initiated and, in parallel, to centrally reduce LH pulsatility. This LH pulsatility stimulates a new wave of follicles secreting oestradiol which, in turn, stimulates prostaglandin synthesis and provokes luteolysis and new ovulation(s). The occurrence of a new follicular wave on days 3-4 of the first male-induced cycle and the initiation of the responsiveness to prostaglandins of the CL from day 3 of the oestrous cycle are probably the key elements which ensure such regularity in the duration of the short cycles. Exogenous progesterone injection suppresses short cycles, probably not by delaying ovulation time, but rather by blocking prostaglandin synthesis, thus impairing luteolysis. The existence, or not, of oestrous behaviour associated to these ovulatory events mainly varies with species: ewes, compared to does, require a more intense endogenous progesterone priming; only ovulations preceded by normal cycles are associated with oestrous behaviour. Thus, the precise and delicate mechanism underlying the existence of short ovulatory and oestrous cycles induced by the male effect appears to be dependent on the various levels of the hypothalamo-pituitary-ovario-uterine axis.

A Simple Approach to the Landau-Zener Formula

ERIC Educational Resources Information Center

Vutha, Amar C.

2010-01-01

The Landau-Zener formula provides the probability of non-adiabatic transitions occurring when two energy levels are swept through an avoided crossing. The formula is derived here in a simple calculation that emphasizes the physics responsible for non-adiabatic population transfer. (Contains 2 figures.)

Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty

USGS Publications Warehouse

Wildhaber, Mark L.; Wikle, Christopher K.; Anderson, Christopher J.; Franz, Kristie J.; Moran, Edward H.; Dey, Rima; Mader, Helmut; Kraml, Julia

2012-01-01

Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology to population response. An additional challenge is quantifying sources of uncertainty given the highly nonlinear nature of interactions between climate variables and community level processes. We present a modeling approach for understanding and accomodating uncertainty by applying multi-scale climate models and a hierarchical Bayesian modeling framework to Midwest fish population dynamics and by linking models for system components together by formal rules of probability. The proposed hierarchical modeling approach will account for sources of uncertainty in forecasts of community or population response. The goal is to evaluate the potential distributional changes in an ecological system, given distributional changes implied by a series of linked climate and system models under various emissions/use scenarios. This understanding will aid evaluation of management options for coping with global climate change. In our initial analyses, we found that predicted pallid sturgeon population responses were dependent on the climate scenario considered.

Bayesian Mapping Reveals That Attention Boosts Neural Responses to Predicted and Unpredicted Stimuli.

PubMed

Garrido, Marta I; Rowe, Elise G; Halász, Veronika; Mattingley, Jason B

2018-05-01

Predictive coding posits that the human brain continually monitors the environment for regularities and detects inconsistencies. It is unclear, however, what effect attention has on expectation processes, as there have been relatively few studies and the results of these have yielded contradictory findings. Here, we employed Bayesian model comparison to adjudicate between 2 alternative computational models. The "Opposition" model states that attention boosts neural responses equally to predicted and unpredicted stimuli, whereas the "Interaction" model assumes that attentional boosting of neural signals depends on the level of predictability. We designed a novel, audiospatial attention task that orthogonally manipulated attention and prediction by playing oddball sequences in either the attended or unattended ear. We observed sensory prediction error responses, with electroencephalography, across all attentional manipulations. Crucially, posterior probability maps revealed that, overall, the Opposition model better explained scalp and source data, suggesting that attention boosts responses to predicted and unpredicted stimuli equally. Furthermore, Dynamic Causal Modeling showed that these Opposition effects were expressed in plastic changes within the mismatch negativity network. Our findings provide empirical evidence for a computational model of the opposing interplay of attention and expectation in the brain.

Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates.

PubMed

Thaker, Maria; Vanak, Abi T; Owen, Cailey R; Ogden, Monika B; Niemann, Sophie M; Slotow, Rob

2011-02-01

Studies that focus on single predator-prey interactions can be inadequate for understanding antipredator responses in multi-predator systems. Yet there is still a general lack of information about the strategies of prey to minimize predation risk from multiple predators at the landscape level. Here we examined the distribution of seven African ungulate species in the fenced Karongwe Game Reserve (KGR), South Africa, as a function of predation risk from all large carnivore species (lion, leopard, cheetah, African wild dog, and spotted hyena). Using observed kill data, we generated ungulate-specific predictions of relative predation risk and of riskiness of habitats. To determine how ungulates minimize predation risk at the landscape level, we explicitly tested five hypotheses consisting of strategies that reduce the probability of encountering predators, and the probability of being killed. All ungulate species avoided risky habitats, and most selected safer habitats, thus reducing their probability of being killed. To reduce the probability of encountering predators, most of the smaller prey species (impala, warthog, waterbuck, kudu) avoided the space use of all predators, while the larger species (wildebeest, zebra, giraffe) only avoided areas where lion and leopard space use were high. The strength of avoidance for the space use of predators generally did not correspond to the relative predation threat from those predators. Instead, ungulates used a simpler behavioral rule of avoiding the activity areas of sit-and-pursue predators (lion and leopard), but not those of cursorial predators (cheetah and African wild dog). In general, selection and avoidance of habitats was stronger than avoidance of the predator activity areas. We expect similar decision rules to drive the distribution pattern of ungulates in other African savannas and in other multi-predator systems, especially where predators differ in their hunting modes.

Adenosine uptake is the major effector of extracellular ATP toxicity in human cervical cancer cells

PubMed Central

Mello, Paola de Andrade; Filippi-Chiela, Eduardo Cremonese; Nascimento, Jéssica; Beckenkamp, Aline; Santana, Danielle Bertodo; Kipper, Franciele; Casali, Emerson André; Nejar Bruno, Alessandra; Paccez, Juliano Domiraci; Zerbini, Luiz Fernando; Wink, Marcia Rosângela; Lenz, Guido; Buffon, Andréia

2014-01-01

In cervical cancer, HPV infection and disruption of mechanisms involving cell growth, differentiation, and apoptosis are strictly linked with tumor progression and invasion. Tumor microenvironment is ATP and adenosine rich, suggesting a role for purinergic signaling in cancer cell growth and death. Here we investigate the effect of extracellular ATP on human cervical cancer cells. We find that extracellular ATP itself has a small cytotoxic effect, whereas adenosine formed from ATP degradation by ectonucleotidases is the main factor responsible for apoptosis induction. The level of P2×7 receptor seemed to define the main cytotoxic mechanism triggered by ATP, since ATP itself eliminated a small subpopulation of cells that express high P2×7 levels, probably through its activation. Corroborating these data, blockage or knockdown of P2×7 only slightly reduced ATP cytotoxicity. On the other hand, cell viability was almost totally recovered with dipyridamole, an adenosine transporter inhibitor. Moreover, ATP-induced apoptosis and signaling—p53 increase, AMPK activation, and PARP cleavage—as well as autophagy induction were also inhibited by dipyridamole. In addition, inhibition of adenosine conversion into AMP also blocked cell death, indicating that metabolization of intracellular adenosine originating from extracellular ATP is responsible for the main effects of the latter in human cervical cancer cells. PMID:25103241

The effects of flow on schooling Devario aequipinnatus: school structure, startle response and information transmission

PubMed Central

Chicoli, A.; Butail, S.; Lun, Y.; Bak-Coleman, J.; Coombs, S.; Paley, D.A.

2014-01-01

To assess how flow affects school structure and threat detection, startle response rates of solitary and small groups of giant danio Devario aequipinnatus were compared to visual looming stimuli in flow and no-flow conditions. The instantaneous position and heading of each D. aequipinnatus were extracted from high-speed videos. Behavioural results indicate that (1) school structure is altered in flow such that D. aequipinnatus orient upstream while spanning out in a crosswise direction, (2) the probability of at least one D. aequipinnatus detecting the visual looming stimulus is higher in flow than no flow for both solitary D. aequipinnatus and groups of eight D. aequipinnatus, however, (3) the probability of three or more individuals responding is higher in no flow than flow. Taken together, these results indicate a higher probability of stimulus detection in flow but a higher probability of internal transmission of information in no flow. Finally, results were well predicted by a computational model of collective fright response that included the probability of direct detection (based on signal detection theory) and indirect detection (i.e. via interactions between group members) of threatening stimuli. This model provides a new theoretical framework for analysing the collective transfer of information among groups of fishes and other organisms. PMID:24773538

Development and application of an empirical probability distribution for the prediction error of re-entry body maximum dynamic pressure

NASA Technical Reports Server (NTRS)

Lanzi, R. James; Vincent, Brett T.

1993-01-01

The relationship between actual and predicted re-entry maximum dynamic pressure is characterized using a probability density function and a cumulative distribution function derived from sounding rocket flight data. This paper explores the properties of this distribution and demonstrates applications of this data with observed sounding rocket re-entry body damage characteristics to assess probabilities of sustaining various levels of heating damage. The results from this paper effectively bridge the gap existing in sounding rocket reentry analysis between the known damage level/flight environment relationships and the predicted flight environment.

On the role of calcium in adrenocorticotropin-induced changes in mitochondrial pregnenolone synthesis.

PubMed

Farese, R V; Prudente, W J

1978-10-01

The importance of calcium in the ACTH-induced increase in adrenal mitochondrial pregnenolone synthesis was evaluated. In mitochondria prepared in the absence of EDTA and albumin, calcium enhanced the binding of cholesterol to cytochrome P-450 and subsequent pregnenolone synthesis. Although these effects of calcium were slightly greater in control than in ACTH-treated mitochondria, a sizeable effect of ACTH remained even at high calcium levels (500 micron). In mitochondria prepared from adrenals homogenized in fluid containing EDTA and albumin, ACTH-induced effects on pregnenolone synthesis were relatively poor unless calcium was added to the incubation mixture. High concentrations of added calcium (500 micron or greater) obviated the need for the labile protein required for ACTH-induced effects in intact mitochondria, presumably by disrupting mitochondria and allowing an "unrestrained" interaction of cholesterol with cytochrome P-450. Thus, cholesterol-rich mitochondria from ACTH plus cycloheximide-treated rats produced large amounts of pregnenolone when high (probably unphysiological) calcium concentrations were present. The present findings suggest that calcium is required at the mitochondrial level for ACTH-induced effects on pregnenolone synthesis, and the reported ACTH-induced increase in intraadrenal calcium may thus amplify the effects of ACTH on steroidogenesis. However, it seems unlikely that calcium is the agent primarily responsible for mediating the ACTH-induced steroidogenic effect at the mitochondrial level.

Neural substrates of the impaired effort expenditure decision making in schizophrenia.

PubMed

Huang, Jia; Yang, Xin-Hua; Lan, Yong; Zhu, Cui-Ying; Liu, Xiao-Qun; Wang, Ye-Fei; Cheung, Eric F C; Xie, Guang-Rong; Chan, Raymond C K

2016-09-01

Unwillingness to expend more effort to pursue high value rewards has been associated with motivational anhedonia in schizophrenia (SCZ) and abnormal dopamine activity in the nucleus accumbens (NAcc). The authors hypothesized that dysfunction of the NAcc and the associated forebrain regions are involved in the impaired effort expenditure decision-making of SCZ. A 2 (reward magnitude: low vs. high) × 3 (probability: 20% vs. 50% vs. 80%) event-related fMRI design in the effort-expenditure for reward task (EEfRT) was used to examine the neural response of 23 SCZ patients and 23 demographically matched control participants when the participants made effort expenditure decisions to pursue uncertain rewards. SCZ patients were significantly less likely to expend high level of effort in the medium (50%) and high (80%) probability conditions than healthy controls. The neural response in the NAcc, the posterior cingulate gyrus and the left medial frontal gyrus in SCZ patients were weaker than healthy controls and did not linearly increase with an increase in reward magnitude and probability. Moreover, NAcc activity was positively correlated with the willingness to expend high-level effort and concrete consummatory pleasure experience. NAcc and posterior cingulate dysfunctions in SCZ patients may be involved in their impaired effort expenditure decision-making. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A new exact method for line radiative transfer

NASA Astrophysics Data System (ADS)

Elitzur, Moshe; Asensio Ramos, Andrés

2006-01-01

We present a new method, the coupled escape probability (CEP), for exact calculation of line emission from multi-level systems, solving only algebraic equations for the level populations. The CEP formulation of the classical two-level problem is a set of linear equations, and we uncover an exact analytic expression for the emission from two-level optically thick sources that holds as long as they are in the `effectively thin' regime. In a comparative study of a number of standard problems, the CEP method outperformed the leading line transfer methods by substantial margins. The algebraic equations employed by our new method are already incorporated in numerous codes based on the escape probability approximation. All that is required for an exact solution with these existing codes is to augment the expression for the escape probability with simple zone-coupling terms. As an application, we find that standard escape probability calculations generally produce the correct cooling emission by the CII 158-μm line but not by the 3P lines of OI.

Contrasting actions of pressor agents in severe autonomic failure

NASA Technical Reports Server (NTRS)

Jordan, J.; Shannon, J. R.; Biaggioni, I.; Norman, R.; Black, B. K.; Robertson, D.

1998-01-01

BACKGROUND: Orthostatic hypotension is the most disabling symptom of autonomic failure. The choice of a pressor agent is largely empiric, and it would be of great value to define predictors of a response. PATIENTS AND METHODS: In 35 patients with severe orthostatic hypotension due to multiple system atrophy or pure autonomic failure, we determined the effect on seated systolic blood pressure (SBP) of placebo, phenylpropanolamine (12.5 mg and 25 mg), yohimbine (5.4 mg), indomethacin (50 mg), ibuprofen (600 mg), caffeine (250 mg), and methylphenidate (5 mg). In a subgroup of patients, we compared the pressor effect of midodrine (5 mg) with the effect of phenylpropanolamine (12.5 mg). RESULTS: There were no significant differences in the pressor responses between patients with multiple system atrophy or pure autonomic failure. When compared with placebo, the pressor response was significant for phenylpropanolamine, yohimbine, and indomethacin. In a subgroup of patients, we confirmed that this pressor effect of phenylpropanolamine, yohimbine, and indomethacin corresponded to a significant increase in standing SBP. The pressor responses to ibuprofen, caffeine, and methylphenidate were not significantly different from placebo. Phenylpropanolamine and midodrine elicited similar pressor responses. There were no significant associations between drug response and autonomic function testing, postprandial hypotension, or plasma catecholamine levels. CONCLUSIONS: We conclude that significant increases in systolic blood pressure can be obtained in patients with orthostatic hypotension due to primary autonomic failure with phenylpropanolamine in low doses or yohimbine or indomethacin in moderate doses. The response to a pressor agent cannot be predicted by autonomic function testing or plasma catecholamines. Therefore, empiric testing with a sequence of medications, based on the risk of side effects in the individual patient and the probability of a response, is a useful approach.

Psychology: red enhances human performance in contests.

PubMed

Hill, Russell A; Barton, Robert A

2005-05-19

Red coloration is a sexually selected, testosterone-dependent signal of male quality in a variety of animals, and in some non-human species a male's dominance can be experimentally increased by attaching artificial red stimuli. Here we show that a similar effect can influence the outcome of physical contests in humans--across a range of sports, we find that wearing red is consistently associated with a higher probability of winning. These results indicate not only that sexual selection may have influenced the evolution of human response to colours, but also that the colour of sportswear needs to be taken into account to ensure a level playing field in sport.

Electrical signals as mechanism of photosynthesis regulation in plants.

PubMed

Sukhov, Vladimir

2016-12-01

This review summarizes current works concerning the effects of electrical signals (ESs) on photosynthesis, the mechanisms of the effects, and its physiological role in plants. Local irritations of plants induce various photosynthetic responses in intact leaves, including fast and long-term inactivation of photosynthesis, and its activation. Irritation-induced ESs, including action potential, variation potential, and system potential, probably causes the photosynthetic responses in intact leaves. Probable mechanisms of induction of fast inactivation of photosynthesis are associated with Ca 2+ - and (or) H + -influxes during ESs generation; long-term inactivation of photosynthesis might be caused by Ca 2+ - and (or) H + -influxes, production of abscisic and jasmonic acids, and inactivation of phloem H + -sucrose symporters. It is probable that subsequent development of inactivation of photosynthesis is mainly associated with decreased CO 2 influx and inactivation of the photosynthetic dark reactions, which induces decreased photochemical quantum yields of photosystems I and II and increased non-photochemical quenching of photosystem II fluorescence and cyclic electron flow around photosystem I. However, other pathways of the ESs influence on the photosynthetic light reactions are also possible. One of them might be associated with ES-connected acidification of chloroplast stroma inducing ferredoxin-NADP + reductase accumulation at the thylakoids in Tic62 and TROL complexes. Mechanisms of ES-induced activation of photosynthesis require further investigation. The probable ultimate effect of ES-induced photosynthetic responses in plant life is the increased photosynthetic machinery resistance to stressors, including high and low temperatures, and enhanced whole-plant resistance to environmental factors at least during 1 h after irritation.

Predicting Fire Severity and Hydrogeomorphic Effects for Wildland Fire Decision Support

NASA Astrophysics Data System (ADS)

Hyde, K.; Woods, S. W.; Calkin, D.; Ryan, K.; Keane, R.

2007-12-01

The Wildland Fire Decision Support System (WFDSS) uses the Fire Spread Probability (FSPro) model to predict the spatial extent of fire, and to assess values-at-risk within probable spread zones. This information is used to support Appropriate Management Response (AMR), which involves decision making regarding fire-fighter deployment, fire suppression requirements, and identification of areas where fire may be safely permitted to take its course. Current WFDSS assessments are generally limited to a binary prediction of whether or not a fire will reach a given location and an assessment of the infrastructure which may be damaged or destroyed by fire. However, an emerging challenge is to expand the capabilities of WFDSS so that it also estimates the probable fire severity, and hence the effect on soil, vegetation and on hydrologic and geomorphic processes such as runoff and soil erosion. We present a conceptual framework within which derivatives of predictive fire modelling are used to predict impacts upon vegetation and soil, from which fire severity and probable post-fire watershed response can be inferred, before a fire actually occurs. Fire severity predictions are validated using Burned Area Reflectance Classification imagery. Recent tests indicate that satellite derived BARC images are a simple and effective means to predict post-fire erosion response based on relative vegetation disturbance. A fire severity prediction which reasonably approximates a BARC image may therefore be used to assess post-fire erosion and flood potential before fire reaches an area. This information may provide a new avenue of reliable support for fire management decisions.

Use of stress-hormone levels and habitat selection to assess functional connectivity of a landscape for an amphibian.

PubMed

Janin, Agnès; Léna, Jean-Paul; Deblois, Sandrine; Joly, Pierre

2012-10-01

The influence of landscape matrix on functional connectivity has been clearly established. Now methods to assess the effects of different land uses on species' movements are needed because current methods are often biased. The use of physiological parameters as indicators of the level of resistance to animal movement associated with different land uses (i.e., matrix resistance) could provide estimates of energetic costs and risks to animals migrating through the matrix. To assess whether corticosterone levels indicate matrix resistance, we conducted experiments on substrate choice and measured levels of corticosterone before and after exposure of toads (Bufo bufo) to 3 common substrates (ploughed soil, meadow, and forest litter). We expected matrix resistance and hormone levels to increase from forest litter (habitat of the toad) to meadows to ploughed soil. Adult toads had higher corticosterone levels on ploughed soil than on forest litter or meadow substrates. Hormone levels did not differ between forest litter and meadow. Toads avoided moving onto ploughed soil. Corticosterone levels in juvenile toads were not related to substrate type; however, hormone levels decreased as humidity increased. Juveniles, unlike adults, did not avoid moving over ploughed soil. The difference in responses between adult and juvenile toads may have been due to differences in experimental design (for juveniles, entire body used to measure corticosterone concentration; for adults, saliva alone); differences in the scale of sensory perception of the substrate (juveniles are much smaller than adults); or differences in cognitive processes between adult and juvenile toads. Adults probably had experience with different substrate types, whereas juveniles first emerging from the water probably did not. As a consequence, arable lands could act as ecological traps for juvenile toads. ©2012 Society for Conservation Biology.

Seismic hazard assessment over time: Modelling earthquakes in Taiwan

NASA Astrophysics Data System (ADS)

Chan, Chung-Han; Wang, Yu; Wang, Yu-Ju; Lee, Ya-Ting

2017-04-01

To assess the seismic hazard with temporal change in Taiwan, we develop a new approach, combining both the Brownian Passage Time (BPT) model and the Coulomb stress change, and implement the seismogenic source parameters by the Taiwan Earthquake Model (TEM). The BPT model was adopted to describe the rupture recurrence intervals of the specific fault sources, together with the time elapsed since the last fault-rupture to derive their long-term rupture probability. We also evaluate the short-term seismicity rate change based on the static Coulomb stress interaction between seismogenic sources. By considering above time-dependent factors, our new combined model suggests an increased long-term seismic hazard in the vicinity of active faults along the western Coastal Plain and the Longitudinal Valley, where active faults have short recurrence intervals and long elapsed time since their last ruptures, and/or short-term elevated hazard levels right after the occurrence of large earthquakes due to the stress triggering effect. The stress enhanced by the February 6th, 2016, Meinong ML 6.6 earthquake also significantly increased rupture probabilities of several neighbouring seismogenic sources in Southwestern Taiwan and raised hazard level in the near future. Our approach draws on the advantage of incorporating long- and short-term models, to provide time-dependent earthquake probability constraints. Our time-dependent model considers more detailed information than any other published models. It thus offers decision-makers and public officials an adequate basis for rapid evaluations of and response to future emergency scenarios such as victim relocation and sheltering.

Dopaminergic modulation of reward-guided decision making in alcohol-preferring AA rats.

PubMed

Oinio, Ville; Bäckström, Pia; Uhari-Väänänen, Johanna; Raasmaja, Atso; Piepponen, Petteri; Kiianmaa, Kalervo

2017-05-30

R**esults from animal gambling models have highlighted the importance of dopaminergic neurotransmission in modulating decision making when large sucrose rewards are combined with uncertainty. The majority of these models use food restriction as a tool to motivate animals to accomplish operant behavioral tasks, in which sucrose is used as a reward. As enhanced motivation to obtain sucrose due to hunger may impact its reward-seeking effect, we wanted to examine the decision-making behavior of rats in a situation where rats were fed ad libitum. For this purpose, we chose alcohol-preferring AA (alko alcohol) rats, as these rats have been shown to have high preference for sweet agents. In the present study, AA rats were trained to self-administer sucrose pellet rewards in a two-lever choice task (one pellet vs. three pellets). Once rational choice behavior had been established, the probability of gaining three pellets was decreased over time (50%, 33%, 25% then 20%). The effect of d-amphetamine on decision making was studied at every probability level, as well as the effect of the dopamine D 1 receptor agonist SKF-81297 and D 2 agonist quinpirole at probability levels of 100% and 25%. d-Amphetamine increased unprofitable choices in a dose-dependent manner at the two lowest probability levels. Quinpirole increased the frequency of unprofitable decisions at the 25% probability level, and SKF-82197 did not affect choice behavior. These results mirror the findings of probabilistic discounting studies using food-restricted rats. Based on this, the use of AA rats provides a new approach for studies on reward-guided decision making. Copyright © 2017 Elsevier B.V. All rights reserved.

Evidence-based guideline update: Treatment of essential tremor

PubMed Central

Zesiewicz, T.A.; Elble, R.J.; Louis, E.D.; Gronseth, G.S.; Ondo, W.G.; Dewey, R.B.; Okun, M.S.; Sullivan, K.L.; Weiner, W.J.

2011-01-01

Background: This evidence-based guideline is an update of the 2005 American Academy of Neurology practice parameter on the treatment of essential tremor (ET). Methods: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 2004 and April 2010. Results and Recommendations: Conclusions and recommendations for the use of propranolol, primidone (Level A, established as effective); alprazolam, atenolol, gabapentin (monotherapy), sotalol, topiramate (Level B, probably effective); nadolol, nimodipine, clonazepam, botulinum toxin A, deep brain stimulation, thalamotomy (Level C, possibly effective); and gamma knife thalamotomy (Level U, insufficient evidence) are unchanged from the previous guideline. Changes to conclusions and recommendations from the previous guideline include the following: 1) levetiracetam and 3,4-diaminopyridine probably do not reduce limb tremor in ET and should not be considered (Level B); 2) flunarizine possibly has no effect in treating limb tremor in ET and may not be considered (Level C); and 3) there is insufficient evidence to support or refute the use of pregabalin, zonisamide, or clozapine as treatment for ET (Level U). PMID:22013182

Evidence-based guideline update: treatment of essential tremor: report of the Quality Standards subcommittee of the American Academy of Neurology.

PubMed

Zesiewicz, T A; Elble, R J; Louis, E D; Gronseth, G S; Ondo, W G; Dewey, R B; Okun, M S; Sullivan, K L; Weiner, W J

2011-11-08

This evidence-based guideline is an update of the 2005 American Academy of Neurology practice parameter on the treatment of essential tremor (ET). A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 2004 and April 2010. Conclusions and recommendations for the use of propranolol, primidone (Level A, established as effective); alprazolam, atenolol, gabapentin (monotherapy), sotalol, topiramate (Level B, probably effective); nadolol, nimodipine, clonazepam, botulinum toxin A, deep brain stimulation, thalamotomy (Level C, possibly effective); and gamma knife thalamotomy (Level U, insufficient evidence) are unchanged from the previous guideline. Changes to conclusions and recommendations from the previous guideline include the following: 1) levetiracetam and 3,4-diaminopyridine probably do not reduce limb tremor in ET and should not be considered (Level B); 2) flunarizine possibly has no effect in treating limb tremor in ET and may not be considered (Level C); and 3) there is insufficient evidence to support or refute the use of pregabalin, zonisamide, or clozapine as treatment for ET (Level U).

Threshold and Beyond: Modeling The Intensity Dependence of Auditory Responses

PubMed Central

2007-01-01

In many studies of auditory-evoked responses to low-intensity sounds, the response amplitude appears to increase roughly linearly with the sound level in decibels (dB), corresponding to a logarithmic intensity dependence. But the auditory system is assumed to be linear in the low-intensity limit. The goal of this study was to resolve the seeming contradiction. Based on assumptions about the rate-intensity functions of single auditory-nerve fibers and the pattern of cochlear excitation caused by a tone, a model for the gross response of the population of auditory nerve fibers was developed. In accordance with signal detection theory, the model denies the existence of a threshold. This implies that regarding the detection of a significant stimulus-related effect, a reduction in sound intensity can always be compensated for by increasing the measurement time, at least in theory. The model suggests that the gross response is proportional to intensity when the latter is low (range I), and a linear function of sound level at higher intensities (range III). For intensities in between, it is concluded that noisy experimental data may provide seemingly irrefutable evidence of a linear dependence on sound pressure (range II). In view of the small response amplitudes that are to be expected for intensity range I, direct observation of the predicted proportionality with intensity will generally be a challenging task for an experimenter. Although the model was developed for the auditory nerve, the basic conclusions are probably valid for higher levels of the auditory system, too, and might help to improve models for loudness at threshold. PMID:18008105

Reticular influences on primary and augmenting responses in the somatosensory cortex.

PubMed

Steriade, M; Morin, D

1981-01-26

The effects of brief, conditioning trains of high-frequency pulses to the midbrain reticular formation (RF) on primary and augmenting responses of somatosensory (SI) cortex were investigated. Testing stimulation was applied to the ventrobasal (VB) thalamus or to the white matter (WM) beneath SI in VB-lesioned animals. The RF-elicited EEG activation was associated with increased firing rates of SI neurons, enhanced probability of early synaptic discharges to VB or WM stimuli, and significantly reduced duration of the suppressed firing period following an afferent VB or WM volley. The diminished latency of the postinhibitory rebound under RF stimulation had the consequence that, within 10/sec shock-train, the second stimulus was delivered following completion of the rebound component and, instead of an augmented potential, generated a field response of primary-type. The dependence of the RF-induced change in augmenting potentials upon the sharpening effect exerted on the preceding inhibitory-rebound sequence was corroborated by analyzing the RF influence on neurons with different time-course of recovery from inhibition. The replacement of augmenting potentials by primary responses under RF stimulation is advanced as the mechanism behind the obliteration of spontaneously developing 'type I' spindle-waves during EEG arousal. The demonstration of RF influences on SI responses to WM stimulation in VB-lesioned animals points out the cortical level of the effects. The reticulo-thalamo-cortical pathways underlying these influences are discussed.

Interaction of temperature and salinity on the expression of immunity factors in different tissues of juvenile turbot Scophthalmus maximus based on response surface methodology

NASA Astrophysics Data System (ADS)

Huang, Zhihui; Ma, Aijun; Wang, Xin'an; Lei, Jilin; Li, Weiye; Wang, Ting; Yang, Zhi; Qu, Jiangbo

2015-01-01

Central Composite Design (CCD) and response surface methodology were used in the experiment to examine the combined effect of temperature (16-28°C) and salinity (18-42) on Hsp70 and IgM genes expression levels in turbot ( Scophthalmus maximus) liver and kidney. The results showed that the coefficients of determination ( R 2 =0.965 2 for liver Hsp70, 0.972 9 for kidney Hsp70, 0.921 for liver IgM and 0.962 1 for kidney IgM) and probability values ( P<0.01) were significant for the regression model. The interactive effect between temperature and salinity on liver Hsp70, kidney Hsp70 and liver IgM were not significant ( P>0.05), while the interactive effect between temperature and salinity on kidney IgM was significant ( P<0.01). The model equation could be used in practice for forecasting Hsp70 and IgM genes expression levels in the liver and kidney of juvenile turbot via applying statistical optimization of the response of interest, at which the maximum liver Hsp70, kidney Hsp70, liver IgM and kidney IgM of 1.48, 1.49, 2.48, and 1.38, respectively, were reached. The present model may be valuable in assessing the feasibility of turbot farming at different geographic locations and, furthermore, could be a useful reference for scientists studying the immunity of turbot.

Examining Spillovers between Long and Short Repeated Prisoner's Dilemma Games Played in the Laboratory.

PubMed

Arechar, Antonio A; Kouchaki, Maryam; Rand, David G

2018-03-01

We had participants play two sets of repeated Prisoner's Dilemma (RPD) games, one with a large continuation probability and the other with a small continuation probability, as well as Dictator Games (DGs) before and after the RPDs. We find that, regardless of which is RPD set is played first, participants typically cooperate when the continuation probability is large and defect when the continuation probability is small. However, there is an asymmetry in behavior when transitioning from one continuation probability to the other. When switching from large to small, transient higher levels of cooperation are observed in the early games of the small continuation set. Conversely, when switching from small to large, cooperation is immediately high in the first game of the large continuation set. We also observe that response times increase when transitioning between sets of RPDs, except for altruistic participants transitioning into the set of RPDs with long continuation probabilities. These asymmetries suggest a bias in favor of cooperation. Finally, we examine the link between altruism and RPD play. We find that small continuation probability RPD play is correlated with giving in DGs played before and after the RPDs, whereas high continuation probability RPD play is not.

The association of air temperature with cardiac arrhythmias

NASA Astrophysics Data System (ADS)

Čulić, Viktor

2017-11-01

The body response to meteorological influences may activate pathophysiological mechanisms facilitating the occurrence of cardiac arrhythmias in susceptible patients. Putative underlying mechanisms include changes in systemic vascular resistance and blood pressure, as well as a network of proinflammatory and procoagulant processes. Such a chain reaction probably occurs within the time window of several hours, so use of daily average values of meteorological elements do not seem appropriate for investigation in this area. In addition, overall synoptic situation, and season-specific combinations of meteorological elements and air pollutant levels probably cause the overall effect rather than a single atmospheric element. Particularly strong interrelations have been described among wind speed, air pressure and temperature, relative air humidity, and suspended particulate matter. This may be the main reason why studies examining the association between temperature and ventricular arrhythmias have found linear positive, negative, J-shaped or no association. Further understanding of the pathophysiological adaptation to atmospheric environment may help in providing recommendations for protective measures during "bad" weather conditions in patients with cardiac arrhythmias.

Complementary and alternative medical therapies in multiple sclerosis--the American Academy of Neurology guidelines: a commentary.

PubMed

Yadav, Vijayshree; Narayanaswami, Pushpa

2014-12-01

Complementary and alternative medicine (CAM) use in individuals with multiple sclerosis (MS) is common, but its use has been limited by a lack of evidence-based guidance. In March 2014, the American Academy of Neurology published the most comprehensive literature review and evidence-based practice guidelines for CAM use in MS. The guideline author panel reviewed and classified articles according to the American Academy of Neurology therapeutic scheme, and recommendations were linked to the evidence strength. Level A recommendations were found for oral cannabis extract effectiveness in the short term for spasticity-related symptoms and pain and ineffectiveness of ginkgo biloba for cognitive function improvement in MS. Key level B recommendations included: Oral cannabis extract or a synthetic cannabis constituent, tetrahydrocannabinol (THC) is probably ineffective for objective spasticity improvement in the short term; Nabiximols oromucosal cannabinoid spray is probably effective for spasticity symptoms, pain, and urinary frequency, but probably ineffective for objective spasticity outcomes and bladder incontinence; Magnetic therapy is probably effective for fatigue reduction in MS; A low-fat diet with fish oil supplementation is probably ineffective for MS-related relapses, disability, fatigue, magnetic resonance imaging lesions, and quality of life. Several Level C recommendations were made. These included possible effectiveness of gingko biloba for fatigue; possible effectiveness of reflexology for MS-related paresthesias; possible ineffectiveness of the Cari Loder regimen for MS-related disability, symptoms, depression, and fatigue; and bee sting therapy for MS relapses, disability, fatigue, magnetic resonance imaging outcomes, and health-related quality of life. Despite the availability of studies evaluating the effects of oral cannabis in MS, the use of these formulations in United States may be limited due to a lack of standardized, commercial US Food and Drug Administration-regulated preparations. Additionally, significant concern about prominent central nervous system-related adverse effects with cannabis was emphasized in the review. Copyright © 2014 Elsevier HS Journals, Inc. All rights reserved.

Compounding effects of sea level rise and fluvial flooding.

PubMed

Moftakhari, Hamed R; Salvadori, Gianfausto; AghaKouchak, Amir; Sanders, Brett F; Matthew, Richard A

2017-09-12

Sea level rise (SLR), a well-documented and urgent aspect of anthropogenic global warming, threatens population and assets located in low-lying coastal regions all around the world. Common flood hazard assessment practices typically account for one driver at a time (e.g., either fluvial flooding only or ocean flooding only), whereas coastal cities vulnerable to SLR are at risk for flooding from multiple drivers (e.g., extreme coastal high tide, storm surge, and river flow). Here, we propose a bivariate flood hazard assessment approach that accounts for compound flooding from river flow and coastal water level, and we show that a univariate approach may not appropriately characterize the flood hazard if there are compounding effects. Using copulas and bivariate dependence analysis, we also quantify the increases in failure probabilities for 2030 and 2050 caused by SLR under representative concentration pathways 4.5 and 8.5. Additionally, the increase in failure probability is shown to be strongly affected by compounding effects. The proposed failure probability method offers an innovative tool for assessing compounding flood hazards in a warming climate.

In Situ Strength Model for Continuous Fibers and Multi-Scale Modeling the Fracture of C/SiC Composites

NASA Astrophysics Data System (ADS)

Zhang, Sheng; Gao, Xiguang; Song, Yingdong

2018-04-01

A new in situ strength model of carbon fibers was developed based on the distribution of defects to predict the stress-strain response and the strength of C/SiC composites. Different levels of defects in the fibers were considered in this model. The defects in the fibers were classified by their effects on the strength of the fiber. The strength of each defect and the probability that the defect appears were obtained from the tensile test of single fibers. The strength model of carbon fibers was combined with the shear-lag model to predict the stress-strain responses and the strengths of fiber bundles and C/SiC minicomposites. To verify the strength model, tensile tests were performed on fiber bundles and C/SiC minicomposites. The predicted and experimental results were in good agreement. Effects of the fiber length, the fiber number and the heat treatment on the final strengths of fiber bundles and C/SiC minicomposites were also discussed.

Higher order Stark effect and transition probabilities on hyperfine structure components of hydrogen like atoms

NASA Astrophysics Data System (ADS)

Pal'Chikov, V. G.

2000-08-01

A quantum-electrodynamical (QED) perturbation theory is developed for hydrogen and hydrogen-like atomic systems with interaction between bound electrons and radiative field being treated as the perturbation. The dependence of the perturbed energy of levels on hyperfine structure (hfs) effects and on the higher-order Stark effect is investigated. Numerical results have been obtained for the transition probability between the hfs components of hydrogen-like bismuth.

Tuned by experience: How orientation probability modulates early perceptual processing.

PubMed

Jabar, Syaheed B; Filipowicz, Alex; Anderson, Britt

2017-09-01

Probable stimuli are more often and more quickly detected. While stimulus probability is known to affect decision-making, it can also be explained as a perceptual phenomenon. Using spatial gratings, we have previously shown that probable orientations are also more precisely estimated, even while participants remained naive to the manipulation. We conducted an electrophysiological study to investigate the effect that probability has on perception and visual-evoked potentials. In line with previous studies on oddballs and stimulus prevalence, low-probability orientations were associated with a greater late positive 'P300' component which might be related to either surprise or decision-making. However, the early 'C1' component, thought to reflect V1 processing, was dampened for high-probability orientations while later P1 and N1 components were unaffected. Exploratory analyses revealed a participant-level correlation between C1 and P300 amplitudes, suggesting a link between perceptual processing and decision-making. We discuss how these probability effects could be indicative of sharpening of neurons preferring the probable orientations, due either to perceptual learning, or to feature-based attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

The ranking probability approach and its usage in design and analysis of large-scale studies.

PubMed

Kuo, Chia-Ling; Zaykin, Dmitri

2013-01-01

In experiments with many statistical tests there is need to balance type I and type II error rates while taking multiplicity into account. In the traditional approach, the nominal [Formula: see text]-level such as 0.05 is adjusted by the number of tests, [Formula: see text], i.e., as 0.05/[Formula: see text]. Assuming that some proportion of tests represent "true signals", that is, originate from a scenario where the null hypothesis is false, power depends on the number of true signals and the respective distribution of effect sizes. One way to define power is for it to be the probability of making at least one correct rejection at the assumed [Formula: see text]-level. We advocate an alternative way of establishing how "well-powered" a study is. In our approach, useful for studies with multiple tests, the ranking probability [Formula: see text] is controlled, defined as the probability of making at least [Formula: see text] correct rejections while rejecting hypotheses with [Formula: see text] smallest P-values. The two approaches are statistically related. Probability that the smallest P-value is a true signal (i.e., [Formula: see text]) is equal to the power at the level [Formula: see text], to an very good excellent approximation. Ranking probabilities are also related to the false discovery rate and to the Bayesian posterior probability of the null hypothesis. We study properties of our approach when the effect size distribution is replaced for convenience by a single "typical" value taken to be the mean of the underlying distribution. We conclude that its performance is often satisfactory under this simplification; however, substantial imprecision is to be expected when [Formula: see text] is very large and [Formula: see text] is small. Precision is largely restored when three values with the respective abundances are used instead of a single typical effect size value.

Probability of Detection (POD) as a statistical model for the validation of qualitative methods.

PubMed

Wehling, Paul; LaBudde, Robert A; Brunelle, Sharon L; Nelson, Maria T

2011-01-01

A statistical model is presented for use in validation of qualitative methods. This model, termed Probability of Detection (POD), harmonizes the statistical concepts and parameters between quantitative and qualitative method validation. POD characterizes method response with respect to concentration as a continuous variable. The POD model provides a tool for graphical representation of response curves for qualitative methods. In addition, the model allows comparisons between candidate and reference methods, and provides calculations of repeatability, reproducibility, and laboratory effects from collaborative study data. Single laboratory study and collaborative study examples are given.

Effect of chronic stress on short and long-term plasticity in dentate gyrus; study of recovery and adaptation.

PubMed

Radahmadi, M; Hosseini, N; Nasimi, A

2014-11-07

Stress dramatically affects synaptic plasticity of the hippocampus, disrupts paired-pulse facilitation and impairs long-term potentiation (LTP). This study was performed to find the effects of chronic restraint stress and recovery period on excitability, paired-pulse response, LTP and to find probable adaptation to very long stress in the dentate gyrus. Thirty-eight male Wistar rats were randomly divided into four groups of Control, Rest-Stress (21 days stress), Stress-Rest (recovery) and Stress-Stress (42 days stress: adaptation). Chronic restraint stress was applied 6-h/day. Input-output functions, paired-pulse responses and LTP were recorded from the dentate gyrus while stimulating the perforant pathway. We found that chronic stress attenuated the responsiveness, paired-pulse response and LTP in the dentate gyrus. A 21-day recovery period, after the stress, improved all the three responses toward normal, indicating reversibility of these stress-related hippocampal changes. There was no significant adaptation to very long stress, probably due to severity of stress. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Model-Based Dose Selection for Intravaginal Ring Formulations Releasing Anastrozole and Levonorgestrel Intended for the Treatment of Endometriosis Symptoms.

PubMed

Reinecke, Isabel; Schultze-Mosgau, Marcus-Hillert; Nave, Rüdiger; Schmitz, Heinz; Ploeger, Bart A

2017-05-01

Pharmacokinetics (PK) of anastrozole (ATZ) and levonorgestrel (LNG) released from an intravaginal ring (IVR) intended to treat endometriosis symptoms were characterized, and the exposure-response relationship focusing on the development of large ovarian follicle-like structures was investigated by modeling and simulation to support dose selection for further studies. A population PK analysis and simulations were performed for ATZ and LNG based on clinical phase 1 study data from 66 healthy women. A PK/PD model was developed to predict the probability of a maximum follicle size ≥30 mm and the potential contribution of ATZ beside the known LNG effects. Population PK models for ATZ and LNG were established where the interaction of LNG with sex hormone-binding globulin (SHBG) as well as a stimulating effect of estradiol on SHBG were considered. Furthermore, simulations showed that doses of 40 μg/d LNG combined with 300, 600, or 1050 μg/d ATZ reached anticipated exposure levels for both drugs, facilitating selection of ATZ and LNG doses in the phase 2 dose-finding study. The main driver for the effect on maximum follicle size appears to be unbound LNG exposure. A 50% probability of maximum follicle size ≥30 mm was estimated for 40 μg/d LNG based on the exposure-response analysis. ATZ in the dose range investigated does not increase the risk for ovarian cysts as occurs with LNG at a dose that does not inhibit ovulation. © 2016, The American College of Clinical Pharmacology.

The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors bayesian approach.

PubMed

Green, Charles; Schmitz, Joy; Lindsay, Jan; Pedroza, Claudia; Lane, Scott; Agnelli, Rob; Kjome, Kimberley; Moeller, F Gerard

2012-01-01

Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbidopa for cocaine dependence; and (2) apply an informative-priors, Bayesian approach for estimating the probability of a subgroup-by-treatment interaction effect. A secondary data analysis of two previously published, double-blind, randomized controlled trials provided complete data for the historical (Study 1: N = 64 placebo), and current (Study 2: N = 113) data sets. Negative binomial regression evaluated Treatment Effectiveness Scores (TES) as a function of medication condition (levodopa/carbidopa, placebo), baseline marijuana use (days in past 30), and their interaction. Bayesian analysis indicated that there was a 96% chance that baseline marijuana use predicts differential response to treatment with levodopa/carbidopa. Simple effects indicated that among participants receiving levodopa/carbidopa the probability that baseline marijuana confers harm in terms of reducing TES was 0.981; whereas the probability that marijuana confers harm within the placebo condition was 0.163. For every additional day of marijuana use reported at baseline, participants in the levodopa/carbidopa condition demonstrated a 5.4% decrease in TES; while participants in the placebo condition demonstrated a 4.9% increase in TES. The potential moderating effect of marijuana on cocaine treatment response should be considered in future trial designs. Applying Bayesian subgroup analysis proved informative in characterizing this patient-treatment interaction effect.

The Influence of Baseline Marijuana Use on Treatment of Cocaine Dependence: Application of an Informative-Priors Bayesian Approach

PubMed Central

Green, Charles; Schmitz, Joy; Lindsay, Jan; Pedroza, Claudia; Lane, Scott; Agnelli, Rob; Kjome, Kimberley; Moeller, F. Gerard

2012-01-01

Background: Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbidopa for cocaine dependence; and (2) apply an informative-priors, Bayesian approach for estimating the probability of a subgroup-by-treatment interaction effect. Method: A secondary data analysis of two previously published, double-blind, randomized controlled trials provided complete data for the historical (Study 1: N = 64 placebo), and current (Study 2: N = 113) data sets. Negative binomial regression evaluated Treatment Effectiveness Scores (TES) as a function of medication condition (levodopa/carbidopa, placebo), baseline marijuana use (days in past 30), and their interaction. Results: Bayesian analysis indicated that there was a 96% chance that baseline marijuana use predicts differential response to treatment with levodopa/carbidopa. Simple effects indicated that among participants receiving levodopa/carbidopa the probability that baseline marijuana confers harm in terms of reducing TES was 0.981; whereas the probability that marijuana confers harm within the placebo condition was 0.163. For every additional day of marijuana use reported at baseline, participants in the levodopa/carbidopa condition demonstrated a 5.4% decrease in TES; while participants in the placebo condition demonstrated a 4.9% increase in TES. Conclusion: The potential moderating effect of marijuana on cocaine treatment response should be considered in future trial designs. Applying Bayesian subgroup analysis proved informative in characterizing this patient-treatment interaction effect. PMID:23115553

Portfolio effects, climate change, and the persistence of small populations: analyses on the rare plant Saussurea weberi.

PubMed

Abbott, Ronald E; Doak, Daniel F; Peterson, Megan L

2017-04-01

The mechanisms that stabilize small populations in the face of environmental variation are crucial to their long-term persistence. Building from diversity-stability concepts in community ecology, within-population diversity is gaining attention as an important component of population stability. Genetic and microhabitat variation within populations can generate diverse responses to common environmental fluctuations, dampening temporal variability across the population as a whole through portfolio effects. Yet, the potential for portfolio effects to operate at small scales within populations or to change with systematic environmental shifts, such as climate change, remain largely unexplored. We tracked the abundance of a rare alpine perennial plant, Saussurea weberi, in 49 1-m 2 plots within a single population over 20 yr. We estimated among-plot correlations in log annual growth rate to test for population-level synchrony and quantify portfolio effects across the 20-yr study period and also in 5-yr subsets based on June temperature quartiles. Asynchrony among plots, due to different plot-level responses to June temperature, reduced overall fluctuations in abundance and the probability of decline in population models, even when accounting for the effects of density dependence on dynamics. However, plots became more synchronous and portfolio effects decreased during the warmest years of the study, suggesting that future climate warming may erode stabilizing mechanisms in populations of this rare plant. © 2017 by the Ecological Society of America.

The Effects of Framing, Reflection, Probability, and Payoff on Risk Preference in Choice Tasks.

PubMed

Kühberger; Schulte-Mecklenbeck; Perner

1999-06-01

A meta-analysis of Asian-disease-like studies is presented to identify the factors which determine risk preference. First the confoundings between probability levels, payoffs, and framing conditions are clarified in a task analysis. Then the role of framing, reflection, probability, type, and size of payoff is evaluated in a meta-analysis. It is shown that bidirectional framing effects exist for gains and for losses. Presenting outcomes as gains tends to induce risk aversion, while presenting outcomes as losses tends to induce risk seeking. Risk preference is also shown to depend on the size of the payoffs, on the probability levels, and on the type of good at stake (money/property vs human lives). In general, higher payoffs lead to increasing risk aversion. Higher probabilities lead to increasing risk aversion for gains and to increasing risk seeking for losses. These findings are confirmed by a subsequent empirical test. Shortcomings of existing formal theories, such as prospect theory, cumulative prospect theory, venture theory, and Markowitz's utility theory, are identified. It is shown that it is not probabilities or payoffs, but the framing condition, which explains most variance. These findings are interpreted as showing that no linear combination of formally relevant predictors is sufficient to capture the essence of the framing phenomenon. Copyright 1999 Academic Press.

Cognitive Diagnostic Attribute-Level Discrimination Indices

ERIC Educational Resources Information Center

Henson, Robert; Roussos, Louis; Douglas, Jeff; He, Xuming

2008-01-01

Cognitive diagnostic models (CDMs) model the probability of correctly answering an item as a function of an examinee's attribute mastery pattern. Because estimation of the mastery pattern involves more than a continuous measure of ability, reliability concepts introduced by classical test theory and item response theory do not apply. The cognitive…

Using High-Probability Instructional Sequences and Explicit Instruction to Teach Multiplication Facts

ERIC Educational Resources Information Center

Leach, Debra

2016-01-01

Students with learning disabilities often struggle with math fact fluency and require specialized interventions to recall basic facts. Deficits in math fact fluency can result in later difficulties when learning higher-level mathematical computation, concepts, and problem solving. The response-to-intervention (RTI) and…

Constructing the Exact Significance Level for a Person-Fit Statistic.

ERIC Educational Resources Information Center

Liou, Michelle; Chang, Chih-Hsin

1992-01-01

An extension is proposed for the network algorithm introduced by C.R. Mehta and N.R. Patel to construct exact tail probabilities for testing the general hypothesis that item responses are distributed according to the Rasch model. A simulation study indicates the efficiency of the algorithm. (SLD)

Future probabilities of coastal floods in Finland

NASA Astrophysics Data System (ADS)

Pellikka, Havu; Leijala, Ulpu; Johansson, Milla M.; Leinonen, Katri; Kahma, Kimmo K.

2018-04-01

Coastal planning requires detailed knowledge of future flooding risks, and effective planning must consider both short-term sea level variations and the long-term trend. We calculate distributions that combine short- and long-term effects to provide estimates of flood probabilities in 2050 and 2100 on the Finnish coast in the Baltic Sea. Our distributions of short-term sea level variations are based on 46 years (1971-2016) of observations from the 13 Finnish tide gauges. The long-term scenarios of mean sea level combine postglacial land uplift, regionally adjusted scenarios of global sea level rise, and the effect of changes in the wind climate. The results predict that flooding risks will clearly increase by 2100 in the Gulf of Finland and the Bothnian Sea, while only a small increase or no change compared to present-day conditions is expected in the Bothnian Bay, where the land uplift is stronger.

Statistical learning of an auditory sequence and reorganization of acquired knowledge: A time course of word segmentation and ordering.

PubMed

Daikoku, Tatsuya; Yatomi, Yutaka; Yumoto, Masato

2017-01-27

Previous neural studies have supported the hypothesis that statistical learning mechanisms are used broadly across different domains such as language and music. However, these studies have only investigated a single aspect of statistical learning at a time, such as recognizing word boundaries or learning word order patterns. In this study, we neutrally investigated how the two levels of statistical learning for recognizing word boundaries and word ordering could be reflected in neuromagnetic responses and how acquired statistical knowledge is reorganised when the syntactic rules are revised. Neuromagnetic responses to the Japanese-vowel sequence (a, e, i, o, and u), presented every .45s, were recorded from 14 right-handed Japanese participants. The vowel order was constrained by a Markov stochastic model such that five nonsense words (aue, eao, iea, oiu, and uoi) were chained with an either-or rule: the probability of the forthcoming word was statistically defined (80% for one word; 20% for the other word) by the most recent two words. All of the word transition probabilities (80% and 20%) were switched in the middle of the sequence. In the first and second quarters of the sequence, the neuromagnetic responses to the words that appeared with higher transitional probability were significantly reduced compared with those that appeared with a lower transitional probability. After switching the word transition probabilities, the response reduction was replicated in the last quarter of the sequence. The responses to the final vowels in the words were significantly reduced compared with those to the initial vowels in the last quarter of the sequence. The results suggest that both within-word and between-word statistical learning are reflected in neural responses. The present study supports the hypothesis that listeners learn larger structures such as phrases first, and they subsequently extract smaller structures, such as words, from the learned phrases. The present study provides the first neurophysiological evidence that the correction of statistical knowledge requires more time than the acquisition of new statistical knowledge. Copyright © 2016 Elsevier Ltd. All rights reserved.

A random walk rule for phase I clinical trials.

PubMed

Durham, S D; Flournoy, N; Rosenberger, W F

1997-06-01

We describe a family of random walk rules for the sequential allocation of dose levels to patients in a dose-response study, or phase I clinical trial. Patients are sequentially assigned the next higher, same, or next lower dose level according to some probability distribution, which may be determined by ethical considerations as well as the patient's response. It is shown that one can choose these probabilities in order to center dose level assignments unimodally around any target quantile of interest. Estimation of the quantile is discussed; the maximum likelihood estimator and its variance are derived under a two-parameter logistic distribution, and the maximum likelihood estimator is compared with other nonparametric estimators. Random walk rules have clear advantages: they are simple to implement, and finite and asymptotic distribution theory is completely worked out. For a specific random walk rule, we compute finite and asymptotic properties and give examples of its use in planning studies. Having the finite distribution theory available and tractable obviates the need for elaborate simulation studies to analyze the properties of the design. The small sample properties of our rule, as determined by exact theory, compare favorably to those of the continual reassessment method, determined by simulation.

Influence of level of education on disability free life expectancy by sex: the ILSA study.

PubMed

Minicuci, N; Noale, M

2005-12-01

To assess the effect of education on Disability Free Life Expectancy among older Italians, using a hierarchical model as indicator of disability, with estimates based on the multistate life table method and IMaCh software. Data were obtained from the Italian Longitudinal Study on Aging which considered a random sample of 5632 individuals. Total life expectancy ranged from 16.5 years for men aged 65 years to 6 years for men aged 80. The age range for women was 19.6 and 8.4 years, respectively. For both sexes, increasing age was associated with a lower probability of recovery from a mild state of disability, with a greater probability of worsening for all individuals presenting an independent state at baseline, and with a greater probability of dying except for women from a mild state of disability. A medium/high educational level was associated with a greater probability of recovery only in men with a mild state of disability at baseline, and with a lower probability of worsening in both sexes, except for men with a mild state of disability at baseline. The positive effects of high education are well established in most research work and, being a modifiable factor, strategies focused on increasing level of education and, hence strengthening access to information and use of health services would produce significant benefits.

Probability Distribution of Dose and Dose-Rate Effectiveness Factor for use in Estimating Risks of Solid Cancers From Exposure to Low-Let Radiation.

PubMed

Kocher, David C; Apostoaei, A Iulian; Hoffman, F Owen; Trabalka, John R

2018-06-01

This paper presents an analysis to develop a subjective state-of-knowledge probability distribution of a dose and dose-rate effectiveness factor for use in estimating risks of solid cancers from exposure to low linear energy transfer radiation (photons or electrons) whenever linear dose responses from acute and chronic exposure are assumed. A dose and dose-rate effectiveness factor represents an assumption that the risk of a solid cancer per Gy at low acute doses or low dose rates of low linear energy transfer radiation, RL, differs from the risk per Gy at higher acute doses, RH; RL is estimated as RH divided by a dose and dose-rate effectiveness factor, where RH is estimated from analyses of dose responses in Japanese atomic-bomb survivors. A probability distribution to represent uncertainty in a dose and dose-rate effectiveness factor for solid cancers was developed from analyses of epidemiologic data on risks of incidence or mortality from all solid cancers as a group or all cancers excluding leukemias, including (1) analyses of possible nonlinearities in dose responses in atomic-bomb survivors, which give estimates of a low-dose effectiveness factor, and (2) comparisons of risks in radiation workers or members of the public from chronic exposure to low linear energy transfer radiation at low dose rates with risks in atomic-bomb survivors, which give estimates of a dose-rate effectiveness factor. Probability distributions of uncertain low-dose effectiveness factors and dose-rate effectiveness factors for solid cancer incidence and mortality were combined using assumptions about the relative weight that should be assigned to each estimate to represent its relevance to estimation of a dose and dose-rate effectiveness factor. The probability distribution of a dose and dose-rate effectiveness factor for solid cancers developed in this study has a median (50th percentile) and 90% subjective confidence interval of 1.3 (0.47, 3.6). The harmonic mean is 1.1, which implies that the arithmetic mean of an uncertain estimate of the risk of a solid cancer per Gy at low acute doses or low dose rates of low linear energy transfer radiation is only about 10% less than the mean risk per Gy at higher acute doses. Data were also evaluated to define a low acute dose or low dose rate of low linear energy transfer radiation, i.e., a dose or dose rate below which a dose and dose-rate effectiveness factor should be applied in estimating risks of solid cancers.

Zonal differences in the distribution and morphology of lipid droplets using 4-amino-pyrazolo-(3,4 d) pyrimidine to lower cholesterol level in the rat adrenal.

PubMed

Szabó, D; Somogyi, J; Acs, Z; Mihály, K

1980-01-01

The effect of reduced blood and adrenal cholesterol levels on adrenocortical lipid droplets have been examined by treating adult rats with 4-amino-pyrazolo-(3,4 d) pyrimidine (4-APP), a drug that inhibits hepatic secretion of lipoproteins. Lowering the blood cholesterol level and the cholesterol content of the adrenals was associated with a marked reduction in the lipid droplets and with a simultaneous increase in their electron density in the inner cortical zones. In the zona glomerulosa cells, no perceptible differences were found in the quantity and morphology of lipid droplets. These data suggest that reduced blood and adrenal cholesterol levels do not affect lipids located in the zona glomerulosa and in the inner cortical zones in the same way, probably due to differences in their intracellular lipid dynamism. Noteworthy, that in spite of the marked lipid depletion, the adrenal glands retained their responsiveness to ACTH stimulation.

A simplified fragility analysis of fan type cable stayed bridges

NASA Astrophysics Data System (ADS)

Khan, R. A.; Datta, T. K.; Ahmad, S.

2005-06-01

A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA) procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeles as a beam supported on spring at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges. The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi-static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis, ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase soft soil condition.

Water resources and potential effects of surface coal mining in the area of the Woodson Preference Right Lease Application, Montana

USGS Publications Warehouse

Cannon, M.R.

1987-01-01

Federal coal lands of the Woodson Preference Right Lease Application are located in Dawson and Richland Counties, northeastern Montana. A probable mine area, comprised of the lease area and adjacent coal lands, contains about 220 million tons of recoverable lignite coal in the 12-37 ft thick Pust coal bed. A hydrologic study has been conducted in the area to describe the water resources and to evaluate potential effects of coal mining on the water resources. Geohydrologic data collected from wells and springs indicate that several aquifers exist in the area. Sandstone beds in the Tongue River Member of the Fort Union Formation (Paleocene age) are the most common aquifers and probably underlie the entire area. The Pust coal bed in the Tongue River Member is water saturated in part of the probable mine area and is dry in other parts of the probable mine area. Other aquifers, located mostly outside of the probable mine area, exist in gravel of the Flaxville Formation (Miocene of Pliocene age) and valley alluvium (Pleistocene and Holocene age). Chemical analyses of groundwater indicate a range in dissolved solids concentration of 240-2,280 mg/L. Surface water resources are limited. Most streams in the area are ephemeral and flow only in response to rainfall or snowmelt. Small reaches of the North and Middle Forks of Burns Creek have intermittent flow. Water sampled from a small perennial reach of the Middle Fork had a dissolved solids concentration of 700 mg/L. Mining of the Pust coal bed would destroy one spring and four stock wells, dewater areas of the Pust coal and sandstone aquifers, and probably lower water levels in seven stock and domestic wells. Mining in the valley of Middle Fork Burns Creek would intercept streamflow and alter flow characteristics of a small perennial reach of stream. Leaching of soluble minerals from mine spoils may cause a long-term degradation of the quality of water in the spoils and in aquifers downgradient from the spoils. Some of the effects on local water supplies could be mitigated by development of new wells in deeper sandstones of the Tongue River Member. Effects of mining on water resources would be minimized if only areas of dry coal were mined. (Author 's abstract)

Affordability and cost-effectiveness: decision-making on the cost-effectiveness plane.

PubMed

Sendi, P P; Briggs, A H

2001-10-01

Much recent research interest has focused on handling uncertainty in cost-effectiveness analysis and in particular the calculation of confidence intervals for incremental cost-effectiveness ratios (ICERs). Problems of interpretation when ICERs are negative have led to two important and related developments: the use of the net-benefit statistic and the presentation of uncertainty in cost-effectiveness analysis using acceptability curves. However, neither of these developments directly addresses the problem that decision-makers are constrained by a fixed-budget and may not be able to fund new, more expensive interventions, even if they have been shown to represent good value for money. In response to this limitation, the authors introduce the 'affordability curve' which reflects the probability that a programme is affordable for a wide range of threshold budgets. The authors argue that the joint probability an intervention is affordable and cost-effective is more useful for decision-making since it captures both dimensions of the decision problem faced by those responsible for health service budgets. Copyright 2001 John Wiley & Sons, Ltd.

Depth-specific fluctuations of gene expression and protein abundance modulate the photophysiology in the seagrass Posidonia oceanica

NASA Astrophysics Data System (ADS)

Procaccini, Gabriele; Ruocco, Miriam; Marín-Guirao, Lázaro; Dattolo, Emanuela; Brunet, Christophe; D'Esposito, Daniela; Lauritano, Chiara; Mazzuca, Silvia; Serra, Ilia Anna; Bernardo, Letizia; Piro, Amalia; Beer, Sven; Björk, Mats; Gullström, Martin; Buapet, Pimchanok; Rasmusson, Lina M.; Felisberto, Paulo; Gobert, Sylvie; Runcie, John W.; Silva, João; Olivé, Irene; Costa, Monya M.; Barrote, Isabel; Santos, Rui

2017-02-01

Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment. The photochemical pathway of energy use was more effective in shallow plants due to higher light availability, but these plants needed more investment in photoprotection and photorepair, requiring higher translation and protein synthesis than deep plants. The genetic differentiation between deep and shallow stands suggests the existence of locally adapted genotypes to contrasting light environments. The depth-specific diel rhythms of photosynthetic and respiratory processes, from molecular to physiological levels, must be considered in the management and conservation of these key coastal ecosystems.

Depth-specific fluctuations of gene expression and protein abundance modulate the photophysiology in the seagrass Posidonia oceanica

PubMed Central

Procaccini, Gabriele; Ruocco, Miriam; Marín-Guirao, Lázaro; Dattolo, Emanuela; Brunet, Christophe; D’Esposito, Daniela; Lauritano, Chiara; Mazzuca, Silvia; Serra, Ilia Anna; Bernardo, Letizia; Piro, Amalia; Beer, Sven; Björk, Mats; Gullström, Martin; Buapet, Pimchanok; Rasmusson, Lina M.; Felisberto, Paulo; Gobert, Sylvie; Runcie, John W.; Silva, João; Olivé, Irene; Costa, Monya M.; Barrote, Isabel; Santos, Rui

2017-01-01

Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment. The photochemical pathway of energy use was more effective in shallow plants due to higher light availability, but these plants needed more investment in photoprotection and photorepair, requiring higher translation and protein synthesis than deep plants. The genetic differentiation between deep and shallow stands suggests the existence of locally adapted genotypes to contrasting light environments. The depth-specific diel rhythms of photosynthetic and respiratory processes, from molecular to physiological levels, must be considered in the management and conservation of these key coastal ecosystems. PMID:28211527

Effect of failure/success feedback and the moderating influence of personality on reward motivation.

PubMed

Anand, Deepika; Oehlberg, Katherine A; Treadway, Michael T; Nusslock, Robin

2016-01-01

While motivation to pursue goals is often assumed to be a trait-like characteristic, it is influenced by a variety of situational factors. In particular, recent experiences of success or failure, as well as cognitive responses to these outcomes, may shape subsequent willingness to expend effort for future rewards. To date, however, these effects have not been explicitly tested. In the present study, 131 healthy individuals received either failure or success feedback on a cognitive task. They were then instructed to either ruminate or distract themselves from their emotions. Finally, they completed the Effort Expenditure for Rewards Task, a laboratory measure of reward motivation. Results indicate that participants who received failure feedback relied more strongly on the reward magnitude when choosing whether to exert greater effort to obtain larger rewards, though this effect only held under conditions of significant uncertainty about whether the effort would be rewarded. Further, participants with high levels of trait inhibition were less responsive to reward value and probability when choosing whether to expend greater effort, results that echo past studies of effort-based decision-making in psychological disorders.

Cue reactivity in non-daily smokers: effects on craving and on smoking behavior.

PubMed

Shiffman, Saul; Dunbar, Michael S; Kirchner, Thomas R; Li, Xiaoxue; Tindle, Hilary A; Anderson, Stewart J; Scholl, Sarah M; Ferguson, Stuart G

2013-03-01

Non-daily, or intermittent smokers (ITS), are increasingly prevalent. Their smoking may be more situational than that of daily smokers (DS), and thus is hypothesized to be more influenced by cues. To assess ITS' response to cues, and compare it to that of DS. Samples of 239 ITS and 207 DS (previously reported in Shiffman et al. 2012a) were studied in 2,586 laboratory cue-reactivity sessions. Craving (Questionnaire of Smoking Urges) and smoking (probability, latency, puff parameters, and carbon monoxide increases) in response to cues was assessed following exposure to neutral cues and cues related to smoking, alcohol, negative affect, positive affect, and smoking prohibitions. Mixed effects models, generalized estimating equations and random-effects survival analyses were used to assess response to cues and differences between DS and ITS. ITS' craving increased following exposure to smoking and alcohol cues and decreased following positive affect cues, but cues had little effect on smoking behaviors. Cue reactivity was similar in ITS and DS. Among ITS, craving intensity predicted smoking probability, latency, and intensity, and the effects on latency were stronger among ITS than DS. Contrary to hypotheses, ITS were not more responsive to laboratory cues than DS. Results show that ITS do experience craving and craving increases that are then associated with smoking.

Effect of Stimulation of Neurotransmitter Systems on Heart Rate Variability and β-Adrenergic Responsiveness of Erythrocytes in Outbred Rats.

PubMed

Kur'yanova, E V; Tryasuchev, A V; Stupin, V O; Teplyi, D L

2017-05-01

We studied heart rate variability and β-adrenergic responsiveness of erythrocytes and changes in these parameters in response to single administration of β-adrenoblocker propranolol (2 mg/kg) in outbred male rats against the background of activation of the noradrenergic, serotonergic, and dopaminergic neurotransmitter systems achieved by 4-fold injections maprotiline (10 mg/kg), 5-hydroxytryptophan (50 mg/kg) combined with fluoxetine (3 mg/kg), and L-DOPA (20 mg/kg) with amantadine (20 mg/kg), respectively. Stimulation of the noradrenergic system moderately enhanced the heart rhythm rigidity and β-adrenergic responsiveness of erythrocytes. In addition, it markedly augmented the moderating effect of subsequently administered propranolol on LF and VLF components in the heart rate variability and reversed the effect of propranolol on β-adrenergic responsiveness of erythrocytes. Stimulation of the serotonergic system dramatically decreased all components in the heart rate variability and pronouncedly enhanced β-adrenergic responsiveness of erythrocytes. Subsequent injection of propranolol slightly restored all components in the heart rate variability and decreased β-adrenergic responsiveness of erythrocytes to the control level. Stimulation of the dopaminergic system made the heart rate more rigid due to decrease of all components in the heart rate variability; in addition, it slightly but significantly enhanced β-adrenergic responsiveness of erythrocytes. Subsequent injection of propranolol produced no significant effects on all components in the heart rate variability and on β-adrenergic responsiveness of erythrocytes. Stimulation of noradrenergic, serotonergic, and dopaminergic neurotransmitter systems produced unidirectional and consorted effects on heart rate variability and β-adrenergic responsiveness of erythrocytes, although the magnitudes of these effects were different. Probably, the changes in the heart rate variability in rats with stimulated neurotransmitter systems results from modification of the cellular sensitivity in peripheral organs to adrenergic influences. However, the differences in the reactions to β-adrenoblocker attest to specificity of the mechanisms underlying the changes in membrane reception and adrenergic pathways in every experimental model employed in this study.

Total serum IgE level influences oral food challenge tests for IgE-mediated food allergies.

PubMed

Horimukai, K; Hayashi, K; Tsumura, Y; Nomura, I; Narita, M; Ohya, Y; Saito, H; Matsumoto, K

2015-03-01

Probability curves predicting oral food challenge test (OFC) results based on specific IgE levels are widely used to prevent serious allergic reactions. Although several confounding factors are known to affect probability curves, the main factors that affect OFC outcomes are currently unclear. We hypothesized that an increased total IgE level would reduce allergic reactivity. Medical records of 337 and 266 patients who underwent OFCs for 3.5 g boiled hen's egg white and 3.1 ml raw cow's milk, respectively, were examined retrospectively. We subdivided the patients into three groups based on total IgE levels and age by percentile (<25th, 25-75th, and >75th percentiles), and logistic regression analyses were performed on each group. Patients with higher total IgE levels were significantly less responsive. In addition, age did not significantly affect the OFC results. Therefore, total IgE levels should be taken into account when predicting OFC results based on food-specific IgE levels. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Digital model analysis of the principal artesian aquifer, Savannah, Georgia area

USGS Publications Warehouse

Counts, H.B.; Krause, R.E.

1977-01-01

A digital model of the principal artesian aquifer has been developed for the Savannah, Georgia, area. The model simulates the response of the aquifer system to various hydrologic stresses. Model results of the water levels and water-level changes are shown on maps. Computations may be extended in time, indicating changes in pumpage were applied to the system and probable results calculated. Drawdown or water-level differences were computed, showing comparisons of different water management alternatives. (Woodard-USGS)

The role of autoshaping in cooperative two-player games between starlings.

PubMed

Reboreda, J C; Kacelnik, A

1993-07-01

We report a study of the behavior of starlings in laboratory situations inspired by the "prisoner's dilemma." Our purpose is to investigate some possible mechanisms for the maintenance of cooperation by reciprocity and to investigate the process of autoshaping at a trial-by-trial level. In Experiment 1, pairs of starlings housed in adjacent cages played a discrete-trial "game" in which food could be obtained only by "cooperation." In this game, pecking at a response key eliminated the opportunity to obtain food but produced food for the partner. If neither bird pecked, neither had the opportunity to obtain food in that trial. Some level of cooperation persisted for several sessions whether the birds had been pretrained for a high or low probability of pecking at the key. The probability of a cooperative response was higher after trials in which the partner responded (and a reward was obtained) than after trials in which neither bird responded (and no reward was obtained), but the probability of a response was even higher after trials in which the same bird had responded, even though no reward was obtained by the actor in these trials. This behavior did not require visual presence of another player, because similar results were obtained in Experiment 2 (a replicate of Experiment 1 in which the members of the pair could not see each other) and in Experiment 3, a game in which each starling played with a computer responding with "tit for tat." Using an omission schedule, in which food was given in all trials in which the bird did not peck, Experiment 4 showed that pecking could be maintained by autoshaping. In this experiment, overall probability of pecking decreased with experience, due to a drop in the tendency to peck in consecutive trials. The probability of pecking in trials following a reinforced trial did not decrease with experience. An implementation of the Rescorla-Wagner model for this situation was capable of reproducing molar, but not molecular, aspects of our results. The results violate the predictions of several game-theoretical models for the evolution of cooperation, including tit for tat, generous tit for tat, and the superior win-stay-lose-shift.

Probable levetiracetam-related serum alkaline phosphatase elevation

PubMed Central

2012-01-01

Background Levetiracetam (LEV) is an antiepileptic drug with a favorable tolerability and safety profile with little or no effect on liver function. Case presentation Here, we reported an epileptic pediatric patient who developed a significant elevation in serum alkaline phosphatase level (ALP) during LEV monotherapy. Moreover, the serum ALP level was surprisingly decreased to normal after LEV discontinuation. The Naranjo Adverse Drug Reaction Probability Scale score was 6, indicating firstly LEV was a probable cause for the increased serum ALP. Conclusions Cautious usage and concerns of the LEV-associated potential ALP elevation should be considered when levetiracetam is prescribed to epilepsy patients, especially pediatric patients. PMID:22994584

[Fractional exhaled nitric oxide in monitoring and therapeutic management of asthma].

PubMed

Melo, Bruno; Costa, Patrício; Afonso, Ariana; Machado, Vânia; Moreira, Carla; Gonçalves, Augusta; Gonçalves, Jean-Pierre

2014-01-01

Asthma is a chronic respiratory disease characterized by hyper-responsiveness and bronchial inflammation. The bronchial inflammation in these patients can be monitored by measuring the fractional exhaled nitric oxide. This study aims to determine fractional exhaled nitric oxide association with peak expiratory flow and with asthma control inferred by the Global Initiative for Asthma. Observational, analytical and cross-sectional study of children with asthma, 6-12 years-old, followed in the Outpatient Respiratory Pathology of Braga Hospital. Sociodemographic and clinical information were collected through a questionnaire. fractional exhaled nitric oxide and peak expiratory flow were determined by portable analyzer Niox Mino® and flow meter, respectively. The sample is constituted by 101 asthmatic children, 63 (62.4%) of males and 38 (37.6%) females. The mean age of participants in the sample is 9.18 (1.99) years. The logistic regression performed with the cutoff value obtained by ROC curve, revealed that fractional exhaled nitric oxide (b(FENO classes) = 0.85; χ(2)Wald (1) = 8.71; OR = 2.33; p = 0.003) has a statistical significant effect on the probability of changing level of asthma control. The odds ratio of going from "controlled" to "partly controlled/uncontrolled" is 2.33 per each level of fractional exhaled nitric oxide. The probability of an asthmatic children change their level of asthma control, from 'controlled' to 'partly controlled/uncontrolled', taking into account a change in their fractional exhaled nitric oxide level, increases 133%.

TECHNOLOGICAL EFFECTS OF GAMMA IRRADIATION OF WHEAT

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

Milner, M.

Extensive literature appearing in the past six years suggests that few if any useful modifications of wheat and flour are produced by gamma irradiation. Deinfestation by treatments of 25,000 to 50,000 rep was proposed, but more information is needed about possible deleterious effects. Fungi, the cause of deterioration of damp grain, can be eliminated by irradiation levels around 250,000 rep, but damage to germination, starch, and protein, as well as darkening due to non-enzymatic browning, question the practicality of such treatment for improving storage properties. A decrease in power consumption in milling occurs, probably related to radiation-splitting of starch, whichmore » also involves decrease in dextrin chain length and gelatinization viscosity, as well as increases in maltose value. An increase in the soluble pentosans and loss of their gelling characteristic when treated with oxidizing agents is also observed, paralleling the appearance of major deterioration in breadmaking quality and loss of bromate response. Reduction of grain viability with irradiation is not paralleled by a corresponding drop in formazan production from TTC, due apparently to the formation of browning products, reducing in character (reductones), at high radiation levels. Evidence concerning the effects of irradiation on dough and breadmaking properties is conflicting but the improvement claimed in weak wheats can be explained on the basis of a stimulation in gas production during dough fermentation due to increase in starch degradation products; probably it does not involve beneficial modification of the gluten. Thus, when irradiated flours are baked with optimum quantities of sugar, amylase supplements and oxidizing agents, no improving effect due to irradiation is observed and the damage to bread properties is progressive; it is reversible in terms of loaf volume but not crumb grain by treatment with potassium bromate, but only at moderate irradiation levels. Reduction of dough mixing time and water absorption, as well as adverse changes in bread flavor and rate of staling are other effects of irradiation. (auth)« less

Ghrelin-reactive immunoglobulins and anxiety, depression and stress-induced cortisol response in adolescents. The TRAILS study.

PubMed

François, Marie; Schaefer, Johanna M; Bole-Feysot, Christine; Déchelotte, Pierre; Verhulst, Frank C; Fetissov, Sergueï O

2015-06-03

Ghrelin, a hunger hormone, has been implicated in the regulation of stress-response, anxiety and depression. Ghrelin-reactive immunoglobulins (Ig) were recently identified in healthy and obese humans showing abilities to increase ghrelin's stability and orexigenic effects. Here we studied if ghrelin-reactive Ig are associated with anxiety and depression and with the stress-induced cortisol response in a general population of adolescents. Furthermore, to test the possible infectious origin of ghrelin-reactive Ig, their levels were compared with serum IgG against common viruses. We measured ghrelin-reactive IgM, IgG and IgA in serum samples of 1199 adolescents from the Dutch TRAILS study and tested their associations with 1) anxiety and depression symptoms assessed with the Youth Self-Report, 2) stress-induced salivary cortisol levels and 3) IgG against human herpesvirus 1, 2, 4 and 6 and Influenza A and B viruses. Ghrelin-reactive IgM and IgG correlated positively with levels of antibodies against Influenza A virus. Ghrelin-reactive IgM correlated negatively with antibodies against Influenza B virus. Ghrelin-reactive IgM correlated positively with anxiety scores in girls and ghrelin-reactive IgG correlated with stress-induced cortisol secretion, but these associations were weak and not significant after correction for multiple testing. These data indicate that production of ghrelin-reactive autoantibodies could be influenced by viral infections. Serum levels of ghrelin-reactive autoantibodies probably do not play a role in regulating anxiety, depression and the stress-response in adolescents from the general population. Copyright © 2015 Elsevier Inc. All rights reserved.

Probabilistic Simulation of Progressive Fracture in Bolted-Joint Composite Laminates

NASA Technical Reports Server (NTRS)

Minnetyan, L.; Singhal, S. N.; Chamis, C. C.

1996-01-01

This report describes computational methods to probabilistically simulate fracture in bolted composite structures. An innovative approach that is independent of stress intensity factors and fracture toughness was used to simulate progressive fracture. The effect of design variable uncertainties on structural damage was also quantified. A fast probability integrator assessed the scatter in the composite structure response before and after damage. Then the sensitivity of the response to design variables was computed. General-purpose methods, which are applicable to bolted joints in all types of structures and in all fracture processes-from damage initiation to unstable propagation and global structure collapse-were used. These methods were demonstrated for a bolted joint of a polymer matrix composite panel under edge loads. The effects of the fabrication process were included in the simulation of damage in the bolted panel. Results showed that the most effective way to reduce end displacement at fracture is to control both the load and the ply thickness. The cumulative probability for longitudinal stress in all plies was most sensitive to the load; in the 0 deg. plies it was very sensitive to ply thickness. The cumulative probability for transverse stress was most sensitive to the matrix coefficient of thermal expansion. In addition, fiber volume ratio and fiber transverse modulus both contributed significantly to the cumulative probability for the transverse stresses in all the plies.

A Decision Support System for effective use of probability forecasts

NASA Astrophysics Data System (ADS)

De Kleermaeker, Simone; Verkade, Jan

2013-04-01

Often, water management decisions are based on hydrological forecasts. These forecasts, however, are affected by inherent uncertainties. It is increasingly common for forecasting agencies to make explicit estimates of these uncertainties and thus produce probabilistic forecasts. Associated benefits include the decision makers' increased awareness of forecasting uncertainties and the potential for risk-based decision-making. Also, a stricter separation of responsibilities between forecasters and decision maker can be made. However, simply having probabilistic forecasts available is not sufficient to realise the associated benefits. Additional effort is required in areas such as forecast visualisation and communication, decision making in uncertainty and forecast verification. Also, revised separation of responsibilities requires a shift in institutional arrangements and responsibilities. A recent study identified a number of additional issues related to the effective use of probability forecasts. When moving from deterministic to probability forecasting, a dimension is added to an already multi-dimensional problem; this makes it increasingly difficult for forecast users to extract relevant information from a forecast. A second issue is that while probability forecasts provide a necessary ingredient for risk-based decision making, other ingredients may not be present. For example, in many cases no estimates of flood damage, of costs of management measures and of damage reduction are available. This paper presents the results of the study, including some suggestions for resolving these issues and the integration of those solutions in a prototype decision support system (DSS). A pathway for further development of the DSS is outlined.

Evaluation of a Class of Simple and Effective Uncertainty Methods for Sparse Samples of Random Variables and Functions

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

Romero, Vicente; Bonney, Matthew; Schroeder, Benjamin

When very few samples of a random quantity are available from a source distribution of unknown shape, it is usually not possible to accurately infer the exact distribution from which the data samples come. Under-estimation of important quantities such as response variance and failure probabilities can result. For many engineering purposes, including design and risk analysis, we attempt to avoid under-estimation with a strategy to conservatively estimate (bound) these types of quantities -- without being overly conservative -- when only a few samples of a random quantity are available from model predictions or replicate experiments. This report examines a classmore » of related sparse-data uncertainty representation and inference approaches that are relatively simple, inexpensive, and effective. Tradeoffs between the methods' conservatism, reliability, and risk versus number of data samples (cost) are quantified with multi-attribute metrics use d to assess method performance for conservative estimation of two representative quantities: central 95% of response; and 10 -4 probability of exceeding a response threshold in a tail of the distribution. Each method's performance is characterized with 10,000 random trials on a large number of diverse and challenging distributions. The best method and number of samples to use in a given circumstance depends on the uncertainty quantity to be estimated, the PDF character, and the desired reliability of bounding the true value. On the basis of this large data base and study, a strategy is proposed for selecting the method and number of samples for attaining reasonable credibility levels in bounding these types of quantities when sparse samples of random variables or functions are available from experiments or simulations.« less

Analyzing force concept inventory with item response theory

NASA Astrophysics Data System (ADS)

Wang, Jing; Bao, Lei

2010-10-01

Item response theory is a popular assessment method used in education. It rests on the assumption of a probability framework that relates students' innate ability and their performance on test questions. Item response theory transforms students' raw test scores into a scaled proficiency score, which can be used to compare results obtained with different test questions. The scaled score also addresses the issues of ceiling effects and guessing, which commonly exist in quantitative assessment. We used item response theory to analyze the force concept inventory (FCI). Our results show that item response theory can be useful for analyzing physics concept surveys such as the FCI and produces results about the individual questions and student performance that are beyond the capability of classical statistics. The theory yields detailed measurement parameters regarding the difficulty, discrimination features, and probability of correct guess for each of the FCI questions.

Variation in harbour porpoise activity in response to seismic survey noise

PubMed Central

Pirotta, Enrico; Brookes, Kate L.; Graham, Isla M.; Thompson, Paul M.

2014-01-01

Animals exposed to anthropogenic disturbance make trade-offs between perceived risk and the cost of leaving disturbed areas. Impact assessments tend to focus on overt behavioural responses leading to displacement, but trade-offs may also impact individual energy budgets through reduced foraging performance. Previous studies found no evidence for broad-scale displacement of harbour porpoises exposed to impulse noise from a 10 day two-dimensional seismic survey. Here, we used an array of passive acoustic loggers coupled with calibrated noise measurements to test whether the seismic survey influenced the activity patterns of porpoises remaining in the area. We showed that the probability of recording a buzz declined by 15% in the ensonified area and was positively related to distance from the source vessel. We also estimated received levels at the hydrophones and characterized the noise response curve. Our results demonstrate how environmental impact assessments can be developed to assess more subtle effects of noise disturbance on activity patterns and foraging efficiency. PMID:24850891

Neural correlates of value, risk, and risk aversion contributing to decision making under risk.

PubMed

Christopoulos, George I; Tobler, Philippe N; Bossaerts, Peter; Dolan, Raymond J; Schultz, Wolfram

2009-10-07

Decision making under risk is central to human behavior. Economic decision theory suggests that value, risk, and risk aversion influence choice behavior. Although previous studies identified neural correlates of decision parameters, the contribution of these correlates to actual choices is unknown. In two different experiments, participants chose between risky and safe options. We identified discrete blood oxygen level-dependent (BOLD) correlates of value and risk in the ventral striatum and anterior cingulate, respectively. Notably, increasing inferior frontal gyrus activity to low risk and safe options correlated with higher risk aversion. Importantly, the combination of these BOLD responses effectively decoded the behavioral choice. Striatal value and cingulate risk responses increased the probability of a risky choice, whereas inferior frontal gyrus responses showed the inverse relationship. These findings suggest that the BOLD correlates of decision factors are appropriate for an ideal observer to detect behavioral choices. More generally, these biological data contribute to the validity of the theoretical decision parameters for actual decisions under risk.

A Composite Likelihood Inference in Latent Variable Models for Ordinal Longitudinal Responses

ERIC Educational Resources Information Center

Vasdekis, Vassilis G. S.; Cagnone, Silvia; Moustaki, Irini

2012-01-01

The paper proposes a composite likelihood estimation approach that uses bivariate instead of multivariate marginal probabilities for ordinal longitudinal responses using a latent variable model. The model considers time-dependent latent variables and item-specific random effects to be accountable for the interdependencies of the multivariate…

Hot pixel generation in active pixel sensors: dosimetric and micro-dosimetric response

NASA Technical Reports Server (NTRS)

Scheick, Leif; Novak, Frank

2003-01-01

The dosimetric response of an active pixel sensor is analyzed. heavy ions are seen to damage the pixel in much the same way as gamma radiation. The probability of a hot pixel is seen to exhibit behavior that is not typical with other microdose effects.

Serum electrolyte and protein changes after intravenous injection of sodium and meglumine diatrizoate (urograffin-370).

PubMed

Nzeh, D A; Erasmus, R T; Aiyedun, B A

1994-03-01

Serum electrolyte and protein changes in 35 Nigerian patients undergoing intravenous urography were evaluated after injection of 60 mls sodium and meglumine diatrizoate (Urograffin-370). Statistically, significant changes were noted in the values of serum calcium, proteins and albumin at 5 and 30 minutes after the injection (P < 0.005). The mean percentage decreases noted were calcium 13%, protein 17% and albumin 13%. At 30 minutes post-injection, the serum protein and albumin levels had incompletely recovered while calcium values continued to decrease. Non-statistically, significant changes were observed in the values of serum sodium, potassium and phosphate at 5 and 30 minutes respectively following contrast medium injection. Alterations in the levels of serum electrolytes especially calcium are most probably responsible for such adverse effects as convulsions and cardiac arrhythmias.

Adaptive Randomization of Neratinib in Early Breast Cancer.

PubMed

Park, John W; Liu, Minetta C; Yee, Douglas; Yau, Christina; van 't Veer, Laura J; Symmans, W Fraser; Paoloni, Melissa; Perlmutter, Jane; Hylton, Nola M; Hogarth, Michael; DeMichele, Angela; Buxton, Meredith B; Chien, A Jo; Wallace, Anne M; Boughey, Judy C; Haddad, Tufia C; Chui, Stephen Y; Kemmer, Kathleen A; Kaplan, Henry G; Isaacs, Claudine; Nanda, Rita; Tripathy, Debasish; Albain, Kathy S; Edmiston, Kirsten K; Elias, Anthony D; Northfelt, Donald W; Pusztai, Lajos; Moulder, Stacy L; Lang, Julie E; Viscusi, Rebecca K; Euhus, David M; Haley, Barbara B; Khan, Qamar J; Wood, William C; Melisko, Michelle; Schwab, Richard; Helsten, Teresa; Lyandres, Julia; Davis, Sarah E; Hirst, Gillian L; Sanil, Ashish; Esserman, Laura J; Berry, Donald A

2016-07-07

The heterogeneity of breast cancer makes identifying effective therapies challenging. The I-SPY 2 trial, a multicenter, adaptive phase 2 trial of neoadjuvant therapy for high-risk clinical stage II or III breast cancer, evaluated multiple new agents added to standard chemotherapy to assess the effects on rates of pathological complete response (i.e., absence of residual cancer in the breast or lymph nodes at the time of surgery). We used adaptive randomization to compare standard neoadjuvant chemotherapy plus the tyrosine kinase inhibitor neratinib with control. Eligible women were categorized according to eight biomarker subtypes on the basis of human epidermal growth factor receptor 2 (HER2) status, hormone-receptor status, and risk according to a 70-gene profile. Neratinib was evaluated against control with regard to 10 biomarker signatures (prospectively defined combinations of subtypes). The primary end point was pathological complete response. Volume changes on serial magnetic resonance imaging were used to assess the likelihood of such a response in each patient. Adaptive assignment to experimental groups within each disease subtype was based on Bayesian probabilities of the superiority of the treatment over control. Enrollment in the experimental group was stopped when the 85% Bayesian predictive probability of success in a confirmatory phase 3 trial of neoadjuvant therapy reached a prespecified threshold for any biomarker signature ("graduation"). Enrollment was stopped for futility if the probability fell to below 10% for every biomarker signature. Neratinib reached the prespecified efficacy threshold with regard to the HER2-positive, hormone-receptor-negative signature. Among patients with HER2-positive, hormone-receptor-negative cancer, the mean estimated rate of pathological complete response was 56% (95% Bayesian probability interval [PI], 37 to 73%) among 115 patients in the neratinib group, as compared with 33% among 78 controls (95% PI, 11 to 54%). The final predictive probability of success in phase 3 testing was 79%. Neratinib added to standard therapy was highly likely to result in higher rates of pathological complete response than standard chemotherapy with trastuzumab among patients with HER2-positive, hormone-receptor-negative breast cancer. (Funded by QuantumLeap Healthcare Collaborative and others; I-SPY 2 TRIAL ClinicalTrials.gov number, NCT01042379.).

Substance P contributes to rapidly adapting receptor responses to pulmonary venous congestion in rabbits.

PubMed Central

Bonham, A C; Kott, K S; Ravi, K; Kappagoda, C T; Joad, J P

1996-01-01

1. This study tested the hypothesis that substance P stimulates rapidly adapting receptors (RARs), contributes to the increase in RAR activity produced by mild pulmonary congestion, and evokes an augmented response from RARs when combined with near-threshold levels of pulmonary congestion. 2. RAR activity, peak tracheal pressure, arterial blood pressure and left atrial pressure were measured in paralysed, anaesthetized and ventilated rabbits. Substance P was given i.v. in one-half log incremental doses to a maximum of 3 micrograms kg-1. Mild pulmonary congestion was produced by inflating a balloon in the left atrium to increase left atrial pressure by 5 mmHg. Near-threshold levels of pulmonary congestion were produced by increasing left atrial pressure by 2 mmHg. 3. Substance P produced dose-dependent increases in RAR activity. The highest dose given increased the activity from 1.3 +/- 0.5 to 11.0 +/- 3.1 impulses bin-1. Increases in left atrial pressure of 5 mmHg increased RAR activity from 3.8 +/- 1.4 to 14.7 +/- 3.9 impulses bin-1. Blockade of NK1 receptors with CP 96345 significantly attenuated RAR responses to substance P and to mild pulmonary congestion. 4. Doses of substance P, which alone had no effect, stimulated the RARs when delivered during near-threshold levels of pulmonary congestion. 5. The findings suggest that substance P augments the stimulatory effect of mild pulmonary congestion on RAR activity, most probably by enhancing hydraulically induced microvascular leak. Images Figure 6 PMID:8735708

Optimal clinical trial design based on a dichotomous Markov-chain mixed-effect sleep model.

PubMed

Steven Ernest, C; Nyberg, Joakim; Karlsson, Mats O; Hooker, Andrew C

2014-12-01

D-optimal designs for discrete-type responses have been derived using generalized linear mixed models, simulation based methods and analytical approximations for computing the fisher information matrix (FIM) of non-linear mixed effect models with homogeneous probabilities over time. In this work, D-optimal designs using an analytical approximation of the FIM for a dichotomous, non-homogeneous, Markov-chain phase advanced sleep non-linear mixed effect model was investigated. The non-linear mixed effect model consisted of transition probabilities of dichotomous sleep data estimated as logistic functions using piecewise linear functions. Theoretical linear and nonlinear dose effects were added to the transition probabilities to modify the probability of being in either sleep stage. D-optimal designs were computed by determining an analytical approximation the FIM for each Markov component (one where the previous state was awake and another where the previous state was asleep). Each Markov component FIM was weighted either equally or by the average probability of response being awake or asleep over the night and summed to derive the total FIM (FIM(total)). The reference designs were placebo, 0.1, 1-, 6-, 10- and 20-mg dosing for a 2- to 6-way crossover study in six dosing groups. Optimized design variables were dose and number of subjects in each dose group. The designs were validated using stochastic simulation/re-estimation (SSE). Contrary to expectations, the predicted parameter uncertainty obtained via FIM(total) was larger than the uncertainty in parameter estimates computed by SSE. Nevertheless, the D-optimal designs decreased the uncertainty of parameter estimates relative to the reference designs. Additionally, the improvement for the D-optimal designs were more pronounced using SSE than predicted via FIM(total). Through the use of an approximate analytic solution and weighting schemes, the FIM(total) for a non-homogeneous, dichotomous Markov-chain phase advanced sleep model was computed and provided more efficient trial designs and increased nonlinear mixed-effects modeling parameter precision.

Variability in Cell Response of Cronobacter sakazakii after Mild-Heat Treatments and Its Impact on Food Safety

PubMed Central

Parra-Flores, Julio; Juneja, Vijay; Garcia de Fernando, Gonzalo; Aguirre, Juan

2016-01-01

Cronobacter spp. have been responsible for severe infections in infants associated with consumption of powdered infant formula and follow-up formulae. Despite several risk assessments described in published studies, few approaches have considered the tremendous variability in cell response that small micropopulations or single cells can have in infant formula during storage, preparation or post process/preparation before the feeding of infants. Stochastic approaches can better describe microbial single cell response than deterministic models as we prove in this study. A large variability of lag phase was observed in single cell and micropopulations of ≤50 cells. This variability increased as the heat shock increased and growth temperature decreased. Obviously, variability of growth of individual Cronobacter sakazakii cell is affected by inoculum size, growth temperature and the probability of cells able to grow at the conditions imposed by the experimental conditions should be taken into account, especially when errors in bottle-preparation practices, such as improper holding temperatures, or manipulation, may lead to growth of the pathogen to a critical cell level. The mean probability of illness from initial inoculum size of 1 cell was below 0.2 in all the cases and for inoculum size of 50 cells the mean probability of illness, in most of the cases, was above 0.7. PMID:27148223

Metal speciation and toxicity of Tamar Estuary water to larvae of the Pacific oyster, Crassostrea gigas.

PubMed

Money, Cathryn; Braungardt, Charlotte B; Jha, Awadhesh N; Worsfold, Paul J; Achterberg, Eric P

2011-07-01

As part of the PREDICT Tamar Workshop, the toxicity of estuarine waters in the Tamar Estuary (southwest England) was assessed by integration of metal speciation determination with bioassays. High temporal resolution metal speciation analysis was undertaken in situ by deployment of a Voltammetric In situ Profiling (VIP) system. The VIP detects Cd (cadmium), Pb (lead) and Cu (copper) species smaller than 4 nm in size and this fraction is termed 'dynamic' and considered biologically available. Cadmium was mainly present in the dynamic form and constituted between 56% and 100% of the total dissolved concentration, which was determined subsequently in the laboratory in filtered discrete samples. In contrast, the dynamic Pb and Cu fractions were less important, with a much larger proportion of these metals associated with organic ligands and/or colloids (45-90% Pb and 46-85% Cu), which probably reduced the toxicological impact of these elements in this system. Static toxicity tests, based on the response of Crassostrea gigas larva exposed to discrete water samples showed a high level of toxicity (up to 100% abnormal development) at two stations in the Tamar, particularly during periods of the tidal cycle when the influence of more pristine coastal water was at its lowest. Competitive ligand-exchange Cu titrations showed that natural organic ligands reduced the free cupric ion concentration to levels that were unlikely to have been the sole cause of the observed toxicity. Nonetheless, it is probable that the combined effect of the metals determined in this work contributed significantly to the bioassay response. Copyright © 2011 Elsevier Ltd. All rights reserved.

Numerical simulation of pore pressure changes in levee under flood conditions

NASA Astrophysics Data System (ADS)

Stanisz, Jacek; Borecka, Aleksandra; Pilecki, Zenon; Kaczmarczyk, Robert

2017-11-01

The article discusses the potential for using numerical simulation to assess the development of deformation and pore pressure changes in a levee as a result of the increase and decrease of the flood wave. The simulation made in FLAC 2D did not take into account the filter-erosion deformation associated with seepage in the levee. The simulations were carried out for a field experimental storage consisting of two combined levees, which was constructed with the help of homogeneous cohesive materials with different filtration coefficients. Calculated and measured pore pressure changes were analysed at 4 monitoring points. The water level was increased to 4 m in 96 hours and decreased in 120 hours. The characteristics of the calculated and measured pore pressure changes over time were similar. The maximum values of the calculated and measured pore pressure were almost identical. The only differences were the greater delay of the experimental levee response to changes in water level increase compared to the response of the numerical model. These differences were probably related to filtering-erosion effects during seepage in the levee.

Vitamin D in Pain Management.

PubMed

Helde-Frankling, Maria; Björkhem-Bergman, Linda

2017-10-18

Vitamin D is a hormone synthesized in the skin in the presence of sunlight. Like other hormones, vitamin D plays a role in a wide range of processes in the body. Here we review the possible role of vitamin D in nociceptive and inflammatory pain. In observational studies, low vitamin D levels have been associated with increased pain and higher opioid doses. Recent interventional studies have shown promising effects of vitamin D supplementation on cancer pain and muscular pain-but only in patients with insufficient levels of vitamin D when starting intervention. Possible mechanisms for vitamin D in pain management are the anti-inflammatory effects mediated by reduced cytokine and prostaglandin release and effects on T-cell responses. The recent finding of vitamin D-mediated inhibition of Prostaglandin E2 (PGE2) is especially interesting and exhibits a credible mechanistic explanation. Having reviewed current literature, we suggest that patients with deficient levels defined as 25-hydroxyvitamin D (25-OHD) levels <30 nmol/L are most likely to benefit from supplementation, while individuals with 25-OHD >50 nmol/L probably have little benefit from supplementation. Our conclusion is that vitamin D may constitute a safe, simple and potentially beneficial way to reduce pain among patients with vitamin D deficiency, but that more randomized and placebo-controlled studies are needed before any firm conclusions can be drawn.

Low-Level Laser Therapy (808 nm) Reduces Inflammatory Response and Oxidative Stress in Rat Tibialis Anterior Muscle After Cryolesion

PubMed Central

Assis, Lívia; Moretti, Ana I.S.; Abrahão, Thalita B.; Cury, Vivian; Souza, Heraldo P.; Hamblin, Michael R.; Parizotto, Nivaldo A.

2012-01-01

Background and Objective Muscle regeneration is a complex phenomenon, involving coordinated activation of several cellular responses. During this process, oxidative stress and consequent tissue damage occur with a severity that may depend on the intensity and duration of the inflammatory response. Among the therapeutic approaches to attenuate inflammation and increase tissue repair, low-level laser therapy (LLLT) may be a safe and effective clinical procedure. The aim of this study was to evaluate the effects of LLLT on oxidative/nitrative stress and inflammatory mediators produced during a cryolesion of the tibialis anterior (TA) muscle in rats. Material and Methods Sixty Wistar rats were randomly divided into three groups (n = 20): control (BC), injured TA muscle without LLLT (IC), injured TA muscle submitted to LLLT (IRI). The injured region was irradiated daily for 4 consecutive days, starting immediately after the lesion using a AlGaAs laser (continuous wave, 808 nm, tip area of 0.00785 cm2, power 30 mW, application time 47 seconds, fluence 180 J/cm2; 3.8 mW/cm2; and total energy 1.4 J). The animals were sacrificed on the fourth day after injury. Results LLLT reduced oxidative and nitrative stress in injured muscle, decreased lipid peroxidation, nitrotyrosine formation and NO production, probably due to reduction in iNOS protein expression. Moreover, LLLT increased SOD gene expression, and decreased the inflammatory response as measured by gene expression of NF-kβ and COX-2 and by TNF-α and IL-1β concentration. Conclusion These results suggest that LLLT could be an effective therapeutic approach to modulate oxidative and nitrative stress and to reduce inflammation in injured muscle. PMID:23001637

Low-level laser therapy (808 nm) reduces inflammatory response and oxidative stress in rat tibialis anterior muscle after cryolesion.

PubMed

Assis, Lívia; Moretti, Ana I S; Abrahão, Thalita B; Cury, Vivian; Souza, Heraldo P; Hamblin, Michael R; Parizotto, Nivaldo A

2012-11-01

Muscle regeneration is a complex phenomenon, involving coordinated activation of several cellular responses. During this process, oxidative stress and consequent tissue damage occur with a severity that may depend on the intensity and duration of the inflammatory response. Among the therapeutic approaches to attenuate inflammation and increase tissue repair, low-level laser therapy (LLLT) may be a safe and effective clinical procedure. The aim of this study was to evaluate the effects of LLLT on oxidative/nitrative stress and inflammatory mediators produced during a cryolesion of the tibialis anterior (TA) muscle in rats. Sixty Wistar rats were randomly divided into three groups (n = 20): control (BC), injured TA muscle without LLLT (IC), injured TA muscle submitted to LLLT (IRI). The injured region was irradiated daily for 4 consecutive days, starting immediately after the lesion using a AlGaAs laser (continuous wave, 808 nm, tip area of 0.00785 cm(2) , power 30 mW, application time 47 seconds, fluence 180 J/cm(2) ; 3.8 mW/cm(2) ; and total energy 1.4 J). The animals were sacrificed on the fourth day after injury. LLLT reduced oxidative and nitrative stress in injured muscle, decreased lipid peroxidation, nitrotyrosine formation and NO production, probably due to reduction in iNOS protein expression. Moreover, LLLT increased SOD gene expression, and decreased the inflammatory response as measured by gene expression of NF-kβ and COX-2 and by TNF-α and IL-1β concentration. These results suggest that LLLT could be an effective therapeutic approach to modulate oxidative and nitrative stress and to reduce inflammation in injured muscle. Copyright © 2012 Wiley Periodicals, Inc.

Forecasting the probability of future groundwater levels declining below specified low thresholds in the conterminous U.S.

USGS Publications Warehouse

Dudley, Robert W.; Hodgkins, Glenn A.; Dickinson, Jesse

2017-01-01

We present a logistic regression approach for forecasting the probability of future groundwater levels declining or maintaining below specific groundwater-level thresholds. We tested our approach on 102 groundwater wells in different climatic regions and aquifers of the United States that are part of the U.S. Geological Survey Groundwater Climate Response Network. We evaluated the importance of current groundwater levels, precipitation, streamflow, seasonal variability, Palmer Drought Severity Index, and atmosphere/ocean indices for developing the logistic regression equations. Several diagnostics of model fit were used to evaluate the regression equations, including testing of autocorrelation of residuals, goodness-of-fit metrics, and bootstrap validation testing. The probabilistic predictions were most successful at wells with high persistence (low month-to-month variability) in their groundwater records and at wells where the groundwater level remained below the defined low threshold for sustained periods (generally three months or longer). The model fit was weakest at wells with strong seasonal variability in levels and with shorter duration low-threshold events. We identified challenges in deriving probabilistic-forecasting models and possible approaches for addressing those challenges.

Delay-induced stochastic bifurcations in a bistable system under white noise

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

Sun, Zhongkui, E-mail: sunzk@nwpu.edu.cn; Fu, Jin; Xu, Wei

2015-08-15

In this paper, the effects of noise and time delay on stochastic bifurcations are investigated theoretically and numerically in a time-delayed Duffing-Van der Pol oscillator subjected to white noise. Due to the time delay, the random response is not Markovian. Thereby, approximate methods have been adopted to obtain the Fokker-Planck-Kolmogorov equation and the stationary probability density function for amplitude of the response. Based on the knowledge that stochastic bifurcation is characterized by the qualitative properties of the steady-state probability distribution, it is found that time delay and feedback intensity as well as noise intensity will induce the appearance of stochasticmore » P-bifurcation. Besides, results demonstrated that the effects of the strength of the delayed displacement feedback on stochastic bifurcation are accompanied by the sensitive dependence on time delay. Furthermore, the results from numerical simulations best confirm the effectiveness of the theoretical analyses.« less

Effects of Toxins on Arachidonic Acid Metabolism in Cultured Rat Pulmonary Alveolar Macrophages

DTIC Science & Technology

1988-12-28

response to’toixin exposure, and fluocinolone may protect against .T-2 toxicosis. Some natural toxins are potent a nd powerful inflammtatory agents (1,2...macrophages in the inflammatory response to natural toxins, we examined the effect of T-2, microcystin-LR known inflammatory agents, and also included...effective in inducing the release of arachidonic acid metabolites, probably due to non-inflammatory nature of the toxin. We observed a large increase in

A Quantum Probability Model of Causal Reasoning

PubMed Central

Trueblood, Jennifer S.; Busemeyer, Jerome R.

2012-01-01

People can often outperform statistical methods and machine learning algorithms in situations that involve making inferences about the relationship between causes and effects. While people are remarkably good at causal reasoning in many situations, there are several instances where they deviate from expected responses. This paper examines three situations where judgments related to causal inference problems produce unexpected results and describes a quantum inference model based on the axiomatic principles of quantum probability theory that can explain these effects. Two of the three phenomena arise from the comparison of predictive judgments (i.e., the conditional probability of an effect given a cause) with diagnostic judgments (i.e., the conditional probability of a cause given an effect). The third phenomenon is a new finding examining order effects in predictive causal judgments. The quantum inference model uses the notion of incompatibility among different causes to account for all three phenomena. Psychologically, the model assumes that individuals adopt different points of view when thinking about different causes. The model provides good fits to the data and offers a coherent account for all three causal reasoning effects thus proving to be a viable new candidate for modeling human judgment. PMID:22593747

Development of the probability of return of spontaneous circulation in intervals without chest compressions during out-of-hospital cardiac arrest: an observational study.

PubMed

Gundersen, Kenneth; Kvaløy, Jan Terje; Kramer-Johansen, Jo; Steen, Petter Andreas; Eftestøl, Trygve

2009-02-06

One of the factors that limits survival from out-of-hospital cardiac arrest is the interruption of chest compressions. During ventricular fibrillation and tachycardia the electrocardiogram reflects the probability of return of spontaneous circulation associated with defibrillation. We have used this in the current study to quantify in detail the effects of interrupting chest compressions. From an electrocardiogram database we identified all intervals without chest compressions that followed an interval with compressions, and where the patients had ventricular fibrillation or tachycardia. By calculating the mean-slope (a predictor of the return of spontaneous circulation) of the electrocardiogram for each 2-second window, and using a linear mixed-effects statistical model, we quantified the decline of mean-slope with time. Further, a mapping from mean-slope to probability of return of spontaneous circulation was obtained from a second dataset and using this we were able to estimate the expected development of the probability of return of spontaneous circulation for cases at different levels. From 911 intervals without chest compressions, 5138 analysis windows were identified. The results show that cases with the probability of return of spontaneous circulation values 0.35, 0.1 and 0.05, 3 seconds into an interval in the mean will have probability of return of spontaneous circulation values 0.26 (0.24-0.29), 0.077 (0.070-0.085) and 0.040(0.036-0.045), respectively, 27 seconds into the interval (95% confidence intervals in parenthesis). During pre-shock pauses in chest compressions mean probability of return of spontaneous circulation decreases in a steady manner for cases at all initial levels. Regardless of initial level there is a relative decrease in the probability of return of spontaneous circulation of about 23% from 3 to 27 seconds into such a pause.

Retreatment with interferon plus ribavirin of chronic hepatitis C non-responders to interferon monotherapy: a meta-analysis of individual patient data

PubMed Central

Cammà, C; Bruno, S; Schepis, F; Lo Iacono, O; Andreone, P; Gramenzi, A G; Mangia, A; Andriulli, A; Puoti, M; Spadaro, A; Freni, M; Di Marco, V; Cino, L; Saracco, G; Chiesa, A; Crosignani, A; Caporaso, N; Morisco, F; Rumi, M G; Craxì, A

2002-01-01

Background and aims: Retreatment with a combination of α interferon (IFN) plus ribavirin of patients with chronic hepatitis C who did not respond to IFN monotherapy has not been assessed in large controlled studies. Methods: To assess the effectiveness and tolerability of IFN/ribavirin retreatment of non-responders to IFN and to identify predictors of complete (biochemical and virological) sustained response, we performed a meta-analysis of individual data on 581 patients from 10 centres. Retreatment with various IFN schedules (mean total dose 544 mega units) and a fixed ribavirin dose (1000–1200 mg/daily depending on body weight) was given for 24–60 (mean 39.5) weeks. Results: Biochemical end of treatment and sustained responses were observed in 271/581 (46.6%; 95% confidence interval (CI) 42.6–50.7%) and in 109/581 (18.7%; 95% CI 15.6–22.0%) cases, respectively. Two hundred and six of 532 patients (38.7%; 95% CI 34.6–42.9%) had an end of treatment complete response to retreatment while a complete sustained response occurred in 88 of 559 (15.7%; 95% CI 12.8–18.8%). Fifty four of 581 patients (9.2%; 95% CI 7.0–11.7%) stopped retreatment due to adverse effects. By logistic regression, complete sustained response was predicted independently by age <45 years (p=0.04), by normal pretreatment γ-glutamyltransferase levels (p=0.01), and by a second course total IFN dose of at least 432 mega units (p=0.008). Conclusions: The overall low probability of effectiveness argues against indiscriminate retreatment of all IFN monotherapy non-responders with IFN/ribavirin. Patients less than 45 years old with normal γ-glutamyltransferase levels who were retreated with high dose long course combination therapy had a complete sustained response rate of 30%. PMID:12427791

Study of T53 engine vibration

NASA Technical Reports Server (NTRS)

Walter, T. J.

1978-01-01

Vibration characteristics for overhauled T53 engines, including rejection rate, principal sources of vibration, and normal procedures taken by the overhaul center to reduce engine vibration are summarized. Analytical and experimental data were compared to determine the engine's dynamic response to unbalance forces with results showing that the engine operates through bending critical speeds. Present rigid rotor balancing techniques are incapable of compensating for the flexible rotor unbalance. A comparison of typical test cell and aircraft vibration levels disclosed significant differences in the engine's dynamic response. A probable spline shift phenomenon was uncovered and investigated. Action items to control costs and reduce vibration levels were identified from analytical and experimental studies.

Involvement of connexin43 in the infrasonic noise-induced glutamate release by cultured astrocytes.

PubMed

Jiang, Shan; Wang, Yong-Qiang; Xu, Cheng-Feng; Li, Ya-Na; Guo, Rong; Li, Ling

2014-05-01

Infrasonic noise/infrasound is a type of environmental noise that threatens public health as a nonspecific biological stressor. Glutamate-related excitotoxicity is thought to be responsible for infrasound-induced impairment of learning and memory. In addition to neurons, astrocytes are also capable of releasing glutamate. In the present study, to identify the effect of infrasound on astroglial glutamate release, cultured astrocytes were exposed to infrasound at 16 Hz, 130 dB for different times. We found that infrasound exposure caused a significant increase in glutamate levels in the extracellular fluid. Moreover, blocking the connexin43 (Cx43) hemichannel or gap junction, decreasing the probability of Cx43 being open or inhibiting of Cx43 expression blocked this increase. The results suggest that glutamate release by Cx43 hemichannels/gap junctions is involved in the response of cultured astrocytes to infrasound.

Stress and quality of life in psoriasis: an update.

PubMed

Basavaraj, Kabbur H; Navya, Mysore Ashok; Rashmi, Ramesh

2011-07-01

Psoriasis is a chronic, relapsing, cutaneous condition with 1-2% prevalence in the general population. There are many factors involved in the induction and/or exacerbation of psoriasis of which stress is a well-known trigger factor in the appearance or exacerbation of psoriasis. Stress reaction in patients with psoriasis is probably mediated by the hypothalamic-pituitary-adrenal relationship with immunologic effects. Stress response involves increased levels of neuroendocrine hormones and autonomic neurotransmitters. Psychological stress or an abnormal response to stressors has been found to modify the evolution of skin disorders such as psoriasis. It can also have substantial psychological, and psychosocial impact on a patient's quality of life. Treatment regimens include stress-reduction strategies, such as biofeedback, meditation, yoga, and self-help approaches. This review focuses the relationship between psoriasis and stress, especially relating to psychosocial, psychological, and emotional stress aspects. © 2011 The International Society of Dermatology.

Establishing a probabilistic reversal learning test in mice: evidence for the processes mediating reward-stay and punishment-shift behaviour and for their modulation by serotonin.

PubMed

Ineichen, Christian; Sigrist, Hannes; Spinelli, Simona; Lesch, Klaus-Peter; Sautter, Eva; Seifritz, Erich; Pryce, Christopher R

2012-11-01

Valid animal models of psychopathology need to include behavioural readouts informed by human findings. In the probabilistic reversal learning (PRL) task, human subjects are confronted with serial reversal of the contingency between two operant stimuli and reward/punishment and, superimposed on this, a low probability (0.2) of punished correct responses/rewarded incorrect responses. In depression, reward-stay and reversals completed are unaffected but response-shift following punished correct response trials, referred to as negative feedback sensitivity (NFS), is increased. The aims of this study were to: establish an operant spatial PRL test appropriate for mice; obtain evidence for the processes mediating reward-stay and punishment-shift responding; and assess effects thereon of genetically- and pharmacologically-altered serotonin (5-HT) function. The study was conducted with wildtype (WT) and heterozygous mutant (HET) mice from a 5-HT transporter (5-HTT) null mutant strain. Mice were mildly food deprived and reward was sugar pellet and punishment was 5-s time out. Mice exhibited high motivation and adaptive reversal performance. Increased probability of punished correct response (PCR) trials per session (p = 0.1, 0.2 or 0.3) led to monotonic decrease in reward-stay and reversals completed, suggesting accurate reward prediction. NFS differed from chance-level at p PCR = 0.1, suggesting accurate punishment prediction, whereas NFS was at chance-level at p = 0.2-0.3. At p PCR = 0.1, HET mice exhibited lower NFS than WT mice. The 5-HTT blocker escitalopram was studied acutely at p PCR = 0.2: a low dose (0.5-1.5 mg/kg) resulted in decreased NFS, increased reward-stay and increased reversals completed, and similarly in WT and HET mice. This study demonstrates that testing PRL in mice can provide evidence on the regulation of reward and punishment processing that is, albeit within certain limits, of relevance to human emotional-cognitive processing, its dysfunction and treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Health effects in women exposed to low levels of ionizing radiation

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

Fabrikant, J.I.

1982-06-01

There are three delayed health effects of radiation which appear at the present time to have importance to women in radiation protection. These are: (1) the probability of cancer-induction at low doses and low-dose rates; (2) the consideration of those cancers in women, notably the breast and the thyroid, attributable to radiation exposure; and (3) the probability of induction of developmental abnormalities in the newborn following low-dose exposure in utero. The bases for the concern over these effects are discussed. (ACR)

Application of PBPK Modeling and Virtual Clinical Study Approaches to Predict the Outcomes of CYP2D6 Genotype-Guided Dosing of Tamoxifen.

PubMed

Nakamura, Toshimichi; Toshimoto, Kota; Lee, Wooin; Imamura, Chiyo K; Tanigawara, Yusuke; Sugiyama, Yuichi

2018-06-19

The Tamoxifen Response by CYP2D6 Genotype-based Treatment-1 (TARGET-1) study (n = 180) was conducted from 2012-2017 in Japan to determine the efficacy of tamoxifen dosing guided by cytochrome P450 2D6 (CYP2D6) genotypes. To predict its outcomes prior to completion, we constructed the comprehensive physiologically based pharmacokinetic (PBPK) models of tamoxifen and its metabolites and performed virtual TARGET-1 studies. Our analyses indicated that the expected probability to achieve the end point (demonstrating the superior efficacy of the escalated tamoxifen dose over the standard dose in patients carrying CYP2D6 variants) was 0.469 on average. As the population size of this virtual clinical study (VCS) increased, the expected probability was substantially increased (0.674 for n = 260). Our analyses also informed that the probability to achieve the end point in the TARGET-1 study was negatively impacted by a large variability in endoxifen levels. Our current efforts demonstrate the promising utility of the PBPK modeling and VCS approaches in prospectively designing effective clinical trials. © 2018 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

A cat's tale: the impact of genetic restoration on Florida panther population dynamics and persistence.

PubMed

Hostetler, Jeffrey A; Onorato, David P; Jansen, Deborah; Oli, Madan K

2013-05-01

1. Genetic restoration has been suggested as a management tool for mitigating detrimental effects of inbreeding depression in small, inbred populations, but the demographic mechanisms underlying population-level responses to genetic restoration remain poorly understood. 2. We studied the dynamics and persistence of the endangered Florida panther Puma concolor coryi population and evaluated the potential influence of genetic restoration on population growth and persistence parameters. As part of the genetic restoration programme, eight female Texas pumas P. c. stanleyana were released into Florida panther habitat in southern Florida in 1995. 3. The overall asymptotic population growth rate (λ) was 1.04 (5th and 95th percentiles: 0.95-1.14), suggesting an increase in the panther population of approximately 4% per year. Considering the effects of environmental and demographic stochasticities and density-dependence, the probability that the population will fall below 10 panthers within 100 years was 0.072 (0-0.606). 4. Our results suggest that the population would have declined at 5% per year (λ = 0.95; 0.83-1.08) in the absence of genetic restoration. Retrospective life table response experiment analysis revealed that the positive effect of genetic restoration on survival of kittens was primarily responsible for the substantial growth of the panther population that would otherwise have been declining. 5. For comparative purposes, we also estimated probability of quasi-extinction under two scenarios - implementation of genetic restoration and no genetic restoration initiative - using the estimated abundance of panthers in 1995, the year genetic restoration was initiated. Assuming no density-dependence, the probability that the panther population would fall below 10 panthers by 2010 was 0.098 (0.002-0.332) for the restoration scenario and 0.445 (0.032-0.944) for the no restoration scenario, providing further evidence that the panther population would have faced a substantially higher risk of extinction if the genetic restoration initiative had not been implemented. 6. Our results, along with those reporting increases in population size and improvements in biomedical correlates of inbreeding depression, provide strong evidence that genetic restoration substantially contributed to the observed increases in the Florida panther population. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Sustained Attention in Mild Alzheimer’s Disease

PubMed Central

Berardi, Anna Maria; Parasuraman, Raja; Haxby, James V.

2008-01-01

The vigilance decrement in perceptual sensitivity was examined in 10 patients with mild Alzheimer’s disease (AD) and 20 age-matched controls. A visual high-event rate digit-discrimination task lasting 7.2 min. (six 1.2 min blocks) was presented at different levels of stimulus degradation. Previous studies have shown that sensitivity decrements (d′) over time at high-stimulus degradation result from demands on effortful processing. For all degradation levels, the overall level of vigilance (d′) was lower in AD patients than in controls. All participants showed sensitivity decrement over blocks, with greater decrement at higher degradation levels. AD patients exhibited greater sensitivity decrement over time at the highest degradation level they all could perform relative to control participants. There were no concomitant changes in either response bias (C) or response times. The results indicate that mild AD patients have overall lower levels of vigilance under conditions that require both automatic and effortful processing. Mild AD patients also exhibit a deficit in the maintenance of vigilance over time under effortful processing conditions. Although the sample of AD patients was small, results further suggest that both possible and probable AD patients had greater sensitivity decrement over time at the highest degradation level than did control participants, but only probable AD patients had lower overall levels of vigilance. In the possible AD patients as a group, the decrement in vigilance occurred in the absence of concurrent deficits on standard attentional tasks, such as the Stroop and Trail Making tests, suggesting that deficits in vigilance over time may appear earlier than deficits in selective attention. PMID:15992254

Areal distribution and concentration of contaminants of concern in surficial streambed and lakebed sediments, Lake St. Clair and tributaries, Michigan, 1990-2003

USGS Publications Warehouse

Rachol, Cynthia M.; Button, Daniel T.

2006-01-01

As part of the Lake St. Clair Regional Monitoring Project, the U.S. Geological Survey evaluated data collected from surficial streambed and lakebed sediments in the Lake Erie-Lake St. Clair drainages. This study incorporates data collected from 1990 through 2003 and focuses primarily on the U.S. part of the Lake St. Clair Basin, including Lake St. Clair, the St. Clair River, and tributaries to Lake St. Clair. Comparable data from the Canadian part of the study area are included where available. The data are compiled into 4 chemical classes and consist of 21 compounds. The data are compared to effects-based sediment-quality guidelines, where the Threshold Effect Level and Lowest Effect Level represent concentrations below which adverse effects on biota are not expected and the Probable Effect Level and Severe Effect Level represent concentrations above which adverse effects on biota are expected to be frequent.Maps in the report show the spatial distribution of the sampling locations and illustrate the concentrations relative to the selected sediment-quality guidelines. These maps indicate that sediment samples from certain areas routinely had contaminant concentrations greater than the Threshold Effect Concentration or Lowest Effect Level. These locations are the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Big Beaver Creek, Red Run, and Paint Creek. Maps also indicated areas that routinely contained sediment contaminant concentrations that were greater than the Probable Effect Concentration or Severe Effect Level. These locations include the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Red Run, within direct tributaries along Lake St. Clair and in marinas within the lake, and within the Clinton River headwaters in Oakland County.Although most samples collected within Lake St. Clair were from sites adjacent to the mouths of its tributaries, samples analyzed for trace-element concentrations were collected throughout the lake. The distribution of trace-element concentrations corresponded well with the results of a two-dimensional hydrodynamic model of flow patterns from the Clinton River into Lake St. Clair. The model was developed independent from the bed sediment analysis described in this report; yet it showed a zone of deposition for outflow from the Clinton River into Lake St. Clair that corresponded well with the spatial distribution of trace-element concentrations. This zone runs along the western shoreline of Lake St. Clair from L'Anse Creuse Bay to St. Clair Shores, Michigan and is reflected in the samples analyzed for mercury and cadmium.Statistical summaries of the concentration data are presented for most contaminants, and selected statistics are compared to effects-based sediment-quality guidelines. Summaries were not computed for dieldrin, chlordane, hexachlorocyclohexane, lindane, and mirex because insufficient data are available for these contaminants. A statistical comparison showed that the median concentration for hexachlorobenzene, anthracene, benz[a]anthracene, chrysene, and pyrene are greater than the Threshold Effect Concentration or Lowest Effect Level.Probable Effect Concentration Quotients provide a mechanism for comparing the concentrations of contaminant mixtures against effects-based biota data. Probable Effect Concentration Quotients were calculated for individual samples and compared to effects-based toxicity ranges. The toxicity-range categories used in this study were nontoxic (quotients < 0.5) and toxic (quotients > 0.5). Of the 546 individual samples for which Probable Effect Concentration Quotients were calculated, 469 (86 percent) were categorized as being nontoxic and 77 (14 percent) were categorized as being toxic. Bed-sediment samples with toxic Probable Effect Concentration Quotients were collected from Paint Creek, Galloway Creek, the main stem of the Clinton River, Big Beaver Creek, Red Run, Clinton River towards the mouth, Lake St. Clair along the western shore, and the St. Clair River near Sarnia.

Probabilistic inversion of expert assessments to inform projections about Antarctic ice sheet responses.

PubMed

Fuller, Robert William; Wong, Tony E; Keller, Klaus

2017-01-01

The response of the Antarctic ice sheet (AIS) to changing global temperatures is a key component of sea-level projections. Current projections of the AIS contribution to sea-level changes are deeply uncertain. This deep uncertainty stems, in part, from (i) the inability of current models to fully resolve key processes and scales, (ii) the relatively sparse available data, and (iii) divergent expert assessments. One promising approach to characterizing the deep uncertainty stemming from divergent expert assessments is to combine expert assessments, observations, and simple models by coupling probabilistic inversion and Bayesian inversion. Here, we present a proof-of-concept study that uses probabilistic inversion to fuse a simple AIS model and diverse expert assessments. We demonstrate the ability of probabilistic inversion to infer joint prior probability distributions of model parameters that are consistent with expert assessments. We then confront these inferred expert priors with instrumental and paleoclimatic observational data in a Bayesian inversion. These additional constraints yield tighter hindcasts and projections. We use this approach to quantify how the deep uncertainty surrounding expert assessments affects the joint probability distributions of model parameters and future projections.

Examining Spillovers between Long and Short Repeated Prisoner’s Dilemma Games Played in the Laboratory

PubMed Central

Arechar, Antonio A.; Kouchaki, Maryam; Rand, David G.

2018-01-01

We had participants play two sets of repeated Prisoner’s Dilemma (RPD) games, one with a large continuation probability and the other with a small continuation probability, as well as Dictator Games (DGs) before and after the RPDs. We find that, regardless of which is RPD set is played first, participants typically cooperate when the continuation probability is large and defect when the continuation probability is small. However, there is an asymmetry in behavior when transitioning from one continuation probability to the other. When switching from large to small, transient higher levels of cooperation are observed in the early games of the small continuation set. Conversely, when switching from small to large, cooperation is immediately high in the first game of the large continuation set. We also observe that response times increase when transitioning between sets of RPDs, except for altruistic participants transitioning into the set of RPDs with long continuation probabilities. These asymmetries suggest a bias in favor of cooperation. Finally, we examine the link between altruism and RPD play. We find that small continuation probability RPD play is correlated with giving in DGs played before and after the RPDs, whereas high continuation probability RPD play is not. PMID:29809199

Response of removal rates to various organic carbon and ammonium loads in laboratory-scale constructed wetlands treating artificial wastewater.

PubMed

Wu, Shubiao; Kuschk, Peter; Wiessner, Arndt; Kästner, Matthias; Pang, Changle; Dong, Renjie

2013-01-01

High levels (92 and 91%) of organic carbon were successfully removed from artificial wastewater by a laboratory-scale constructed wetland under inflow loads of 670 mg/m2 x d (100 mg/d) and 1600 mg/m2d (240 mg/d), respectively. Acidification to pH 3.0 was observed at the low organic carbon load, which further inhibited the denitrification process. An increase in carbon load, however, was associated with a significant elevation of pH to 6.0. In general, sulfate and nitrate reduction were relatively high, with mean levels of 87 and 90%, respectively. However, inhibition of nitrification was initiated with an increase in carbon loads. This effect was probably a result of competition for oxygen by heterotrophic bacteria and an inhibitory effect of sulfide (S2) toxicity (concentration approximately 3 mg/L). In addition, numbers of healthy stalks of Juncus effusus (common rush) decreased from 14 000 to 10 000/m2 with an increase of sulfide concentration, indicating the negative effect of sulfide toxicity on the wetland plants.

Climate change: believing and seeing implies adapting.

PubMed

Blennow, Kristina; Persson, Johannes; Tomé, Margarida; Hanewinkel, Marc

2012-01-01

Knowledge of factors that trigger human response to climate change is crucial for effective climate change policy communication. Climate change has been claimed to have low salience as a risk issue because it cannot be directly experienced. Still, personal factors such as strength of belief in local effects of climate change have been shown to correlate strongly with responses to climate change and there is a growing literature on the hypothesis that personal experience of climate change (and/or its effects) explains responses to climate change. Here we provide, using survey data from 845 private forest owners operating in a wide range of bio-climatic as well as economic-social-political structures in a latitudinal gradient across Europe, the first evidence that the personal strength of belief and perception of local effects of climate change, highly significantly explain human responses to climate change. A logistic regression model was fitted to the two variables, estimating expected probabilities ranging from 0.07 (SD ± 0.01) to 0.81 (SD ± 0.03) for self-reported adaptive measures taken. Adding socio-demographic variables improved the fit, estimating expected probabilities ranging from 0.022 (SD ± 0.008) to 0.91 (SD ± 0.02). We conclude that to explain and predict adaptation to climate change, the combination of personal experience and belief must be considered.

Mention effect in information diffusion on a micro-blogging network.

PubMed

Bao, Peng; Shen, Hua-Wei; Huang, Junming; Chen, Haiqiang

2018-01-01

Micro-blogging systems have become one of the most important ways for information sharing. Network structure and users' interactions such as forwarding behaviors have aroused considerable research attention, while mention, as a key feature in micro-blogging platforms which can improve the visibility of a message and direct it to a particular user beyond the underlying social structure, is seldom studied in previous works. In this paper, we empirically study the mention effect in information diffusion, using the dataset from a population-scale social media website. We find that users with high number of followers would receive much more mentions than others. We further investigate the effect of mention in information diffusion by examining the response probability with respect to the number of mentions in a message and observe a saturation at around 5 mentions. Furthermore, we find that the response probability is the highest when a reciprocal followship exists between users, and one is more likely to receive a target user's response if they have similar social status. To illustrate these findings, we propose the response prediction task and formulate it as a binary classification problem. Extensive evaluation demonstrates the effectiveness of discovered factors. Our results have consequences for the understanding of human dynamics on the social network, and potential implications for viral marketing and public opinion monitoring.

Modeling the probability distribution of peak discharge for infiltrating hillslopes

NASA Astrophysics Data System (ADS)

Baiamonte, Giorgio; Singh, Vijay P.

2017-07-01

Hillslope response plays a fundamental role in the prediction of peak discharge at the basin outlet. The peak discharge for the critical duration of rainfall and its probability distribution are needed for designing urban infrastructure facilities. This study derives the probability distribution, denoted as GABS model, by coupling three models: (1) the Green-Ampt model for computing infiltration, (2) the kinematic wave model for computing discharge hydrograph from the hillslope, and (3) the intensity-duration-frequency (IDF) model for computing design rainfall intensity. The Hortonian mechanism for runoff generation is employed for computing the surface runoff hydrograph. Since the antecedent soil moisture condition (ASMC) significantly affects the rate of infiltration, its effect on the probability distribution of peak discharge is investigated. Application to a watershed in Sicily, Italy, shows that with the increase of probability, the expected effect of ASMC to increase the maximum discharge diminishes. Only for low values of probability, the critical duration of rainfall is influenced by ASMC, whereas its effect on the peak discharge seems to be less for any probability. For a set of parameters, the derived probability distribution of peak discharge seems to be fitted by the gamma distribution well. Finally, an application to a small watershed, with the aim to test the possibility to arrange in advance the rational runoff coefficient tables to be used for the rational method, and a comparison between peak discharges obtained by the GABS model with those measured in an experimental flume for a loamy-sand soil were carried out.

Stream fish occurrence in response to impervious cover, historic land use, and hydrogeomorphic factors

USGS Publications Warehouse

Wenger, Seth J.; Peterson, James T.; Freeman, Mary C.; Freeman, Byron J.; Homans, D. David

2008-01-01

We evaluated competing models explaining the occurrence of five stream fishes in an urbanizing watershed to determine the relative importance of (a) impervious surface and other indicators of current land use, (b) historic land use (e.g., agriculture, impoundments), and (c) hydrogeomorphic characteristics (e.g., stream size, elevation, geology). For four of five species, the best-supported models were those that included both current effective impervious cover and historic land use predictor variables, although models with only effective impervious cover were equally well supported for two of those species. For the best-supported models for three species, occurrence probability was predicted to approach zero at levels of development equivalent to about 2%–4% effective impervious cover in the surrounding region. Data were drawn from 357 fish collections made in the Etowah River basin, Georgia, USA, between 1998 and 2003 and analyzed using hierarchical logistic regression accounting for imperfect species detection. This is the first study we know of to examine the response of individual fish species to both increasing impervious cover and historic land use. Such individual species assessments will be increasingly necessary to guide policies for managing urban effects and preventing extirpations of sensitive species.

Block-Dependent Sedation during Epidural Anaesthesia is Associated with Delayed Brainstem Conduction

PubMed Central

Wadhwa, Anupama; Shah, Yunus M.; Lin, Chum-Ming; Haugh, Gilbert S.; Sessler, Daniel I.

2005-01-01

Neuraxial anaesthesia produces a sedative and anesthetic-sparing effect. Recent evidence suggests that spinal cord anaesthesia modifies reticulo-thalamo-cortical arousal by decreasing afferent sensory transmission. We hypothesized that epidural anaesthesia produces sensory deafferentation-dependent sedation that is associated with impairment of brainstem transmission. We used brainstem auditory evoked potentials (BAEP) to evaluate reticular function in 11 volunteers. Epidural anaesthesia was induced with 2% 2-chloroprocaine. Hemodynamic and respiratory responses, sensory block level, sedation depth and BAEP were assessed throughout induction and resolution of epidural anaesthesia. Sedation was evaluated using verbal rating score (VRS), observer's assessment alertness/sedation (OAA/S) score, and bispectral index (BIS). Prediction probability (PK) was used to associate sensory block with sedation, as well as BIS with other sedation measures. Spearman rank order correlation was used to associate block level and sedation with the absolute and interpeak BAEP latencies. Sensory block level significantly predicted VRS (PK = 0.747), OAA/S score (PK = 0.748) and BIS. Bispectral index predicted VRS and OAA/S score (PK = 0.728). The latency of wave III of BAEP significantly correlated with sedation level (rho = 0.335, P < 0.01) and sensory block (rho = 0.394, P < 0.01). The other BAEP parameters did not change during epidural anaesthesia. Hemodynamic and respiratory responses remained stable throughout the study. Sedation during epidural anaesthesia depends on sensory block level and is associated with detectable block-dependent alterations in the brainstem auditory evoked responses. Sensory deafferentation may reduce CNS alertness through mechanisms related to brainstem neural activity. PMID:15220178

Analgesic efficacy and bioavailability of ketorolac in postoperative pain: a probability analysis.

PubMed

Pérez-Urizar, J; Granados-Soto, V; Castañeda-Hernández, G; Hong, E; González, C; Martínez, J L; Flores-Murrieta, F J

2000-01-01

The analgesic efficacy and bioavailability of 30 mg intramuscular ketorolac was studied in 24 patients with severe or very severe postoperative pain. Pain and pain relief were determined by a five-point verbal rating scale and data were submitted to a probability analysis. Ketorolac plasma levels were determined by high-performance liquid chromatography. Two patients chose not to finish the study; 22 patients completed the study achieving at least good pain relief. Of these 22 patients, 13 reached complete pain relief. Ketorolac was rapidly absorbed. Notwithstanding, pain relief increased gradually, showing considerable delay with regard to plasma concentrations. Analysis of the probability-time curves revealed that 25% of the patients obtained moderate pain relief at 7 min after ketorolac administration, 50% at 11 min, 75% at 29 min, and 95% at 60 min. Good pain relief was achieved in 25, 50, and 75% of the patients at 1.1, 1.8, and 2.7 h, respectively. Complete pain relief was achieved in 25% and 50% of the patients at 2.6 h and 3.7 h, respectively. The probability of exhibiting an acceptable pain relief in responsive patients for more than 5 h was 0.97. No serious side effects were detected. Results show that 30 mg intramuscular ketorolac is an adequate treatment for postoperative pain in the Mexican population. Therefore, the use of higher doses is not justified. Due to gradual installation of analgesia, administration of additional analgesic medication before 1 h is not recommended.

Wave processes and geologic responses on the floor of the Yellow Sea

USGS Publications Warehouse

Booth, James S.; Winters, William J.

1991-01-01

The floor of the Yellow Sea is a geologically mundane surface: it is nearly horizontal, lacks relief, and, with few exceptions, is devoid of conspicuous geomorphologic features. However, it is the principal repository for the prodigious sediment load of the Huanghe (Yellow River); and, due to its inherent shallowness (average depth is 40 m), it is frequently stressed by waves generated by winter storms and typhoons. Analyses of mass physical properties of cores representing the upper few meters of sediment in the central and north-central Yellow Sea (near the Shandong Peninsula), in conjunction with analyses of slope stability, failure modes, and erodibility, permit an assessment of the likelihood and effect of dynamic, transient geologic events on the seabed.Vane shear-strength profiles along with consolidation test data indicate that the present surface of the seabed is in a depositional mode and is compacting normally. in addition, liquid-limit profiles imply that in the study area these neritic sediments have been accumulating in an environment that probably has not been modified significantly since sea level reached its current level. There is no geotechnical evidence in the nine cores recovered that slope failures have occurred, and clasts, sand lenses or other manifestations of mass movements, including flows, also are absent. These observations support previous interpretations of seismic records. Moreover, slope stability analysis for static conditions shows that the sea floor is quite stable.Regardless, shear-stress levels generated by cyclic loading during major storms may approach the sediment shear strengths, and, when coupled with concomitant excess pore pressures, could cause slope failure. Unless the failed beds collapsed or flowed, however, there probably would be little conspicuous evidence of such a failure. in fact, evaluation of the potential of these sediments for disintegrative behavior suggests that they are not prone to either collapse or flow.Storm waves also generate oscillatory bottom currents that may erode the seabed. Whether the sediment is considered as cohesionless or cohesive, typhoons could have the potential to erode at all water depths within the Yellow Sea (i.e., to 90 m), and winter storms to water depths of 60 m or more. However, in the case of cohesive behavior, it could be that the effect of winter storms and most typhoons is generally less extreme. If the sea floor is repeatedly scoured, it is likely limited to the top few centimeters.Despite the fact that storm waves may cause slope failure and are certainly responsible for frequent scouring, they probably leave only a subtle sedimentologic imprint on the seabed.

Effects of partial reinforcement and time between reinforced trials on terminal response rate in pigeon autoshaping.

PubMed

Gottlieb, Daniel A

2006-03-01

Partial reinforcement often leads to asymptotically higher rates of responding and number of trials with a response than does continuous reinforcement in pigeon autoshaping. However, comparisons typically involve a partial reinforcement schedule that differs from the continuous reinforcement schedule in both time between reinforced trials and probability of reinforcement. Two experiments examined the relative contributions of these two manipulations to asymptotic response rate. Results suggest that the greater responding previously seen with partial reinforcement is primarily due to differential probability of reinforcement and not differential time between reinforced trials. Further, once established, differences in responding are resistant to a change in stimulus and contingency. Secondary response theories of autoshaped responding (theories that posit additional response-augmenting or response-attenuating mechanisms specific to partial or continuous reinforcement) cannot fully accommodate the current body of data. It is suggested that researchers who study pigeon autoshaping train animals on a common task prior to training them under different conditions.

Influence of Image Interactivity on Approach Responses towards an Online Retailer.

ERIC Educational Resources Information Center

Fiore, Ann Marie; Jin, Hyun-Jeong

2003-01-01

Measured the effect of exposure to an image interactivity function from an apparel retailer's Web site on approach responses towards the retailer. Dependent variables included attitude towards the online store, willingness to purchase, probability of spending more time than planned shopping, and likelihood of patronizing the online retailer's…

The balance between stress resilience and vulnerability is regulated by corticotropin-releasing hormone during the critical postnatal period for sensory development.

PubMed

Cramer, Tomer; Kisliouk, Tatiana; Yeshurun, Shlomo; Meiri, Noam

2015-08-01

Determining whether a stressful event will lead to stress-resilience or vulnerability depends probably on an adjustable stress response set point, which is most likely effective during postnatal sensory development and involves the regulation of corticotrophin-releasing hormone (CRH) expression. During the critical period of thermal-control establishment in 3-day-old chicks, heat stress was found to render resilient or sensitized response, depending on the ambient temperature. These two different responses were correlated with the amount of activation of the hypothalamic-pituitary-adrenal (HPA) axis. The expression of CRH mRNA in the hypothalamic paraventricular nucleus was augmented during heat challenge a week after heat conditioning in chicks which were trained to be vulnerable to heat, while it declined in chicks that were trained to be resilient. To study the role of CRH in HPA-axis plasticity, CRH or Crh-antisense were intracranially injected into the third ventricle. CRH caused an elevation of both body temperature and plasma corticosterone level, while Crh-antisense caused an opposite response. Moreover, these effects had long term implications by reversing a week later, heat resilience into vulnerability and vice versa. Chicks that had been injected with CRH followed by exposure to mild heat stress, normally inducing resilience, demonstrated, a week later, an elevation in body temperature, and Crh mRNA level similar to heat vulnerability, while Crh-antisense injected chicks, which were exposed to harsh temperature, responded in heat resilience. These results demonstrate a potential role for CRH in determining the stress resilience/vulnerability balance. © 2014 Wiley Periodicals, Inc.

Parameter Tuning and Calibration of RegCM3 with MIT-Emanuel Cumulus Parameterization Scheme over CORDEX East Asian Domain

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

Zou, Liwei; Qian, Yun; Zhou, Tianjun

2014-10-01

In this study, we calibrated the performance of regional climate model RegCM3 with Massachusetts Institute of Technology (MIT)-Emanuel cumulus parameterization scheme over CORDEX East Asia domain by tuning the selected seven parameters through multiple very fast simulated annealing (MVFSA) sampling method. The seven parameters were selected based on previous studies, which customized the RegCM3 with MIT-Emanuel scheme through three different ways by using the sensitivity experiments. The responses of model results to the seven parameters were investigated. Since the monthly total rainfall is constrained, the simulated spatial pattern of rainfall and the probability density function (PDF) distribution of daily rainfallmore » rates are significantly improved in the optimal simulation. Sensitivity analysis suggest that the parameter “relative humidity criteria” (RH), which has not been considered in the default simulation, has the largest effect on the model results. The responses of total rainfall over different regions to RH were examined. Positive responses of total rainfall to RH are found over northern equatorial western Pacific, which are contributed by the positive responses of explicit rainfall. Followed by an increase of RH, the increases of the low-level convergence and the associated increases in cloud water favor the increase of the explicit rainfall. The identified optimal parameters constrained by the total rainfall have positive effects on the low-level circulation and the surface air temperature. Furthermore, the optimized parameters based on the extreme case are suitable for a normal case and the model’s new version with mixed convection scheme.« less

PROJECTED POPULATION-LEVEL EFFECTS OF THIOBENCARB EXPOSURE ON THE MYSID, AMERICAMYSIS BAHIA, AND EXTINCTION PROBABILITY IN A CONCENTRATION-DECAY EXPOSURE SYSTEM

EPA Science Inventory

Population-level effects of the mysid, Americamysis bahia, exposed to varying thiobencarb concentrations were estimated using stage-structured matrix models. A deterministic density-independent matrix model estimated the decrease in population growth rate, l, with increas...

Realized detection and capture probabilities for giant gartersnakes (Thamnophis gigas) using modified floating aquatic funnel traps

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-01-01

Detection and capture probabilities for giant gartersnakes (Thamnophis gigas) are very low, and successfully evaluating the effects of variables or experimental treatments on giant gartersnake populations will require greater detection and capture probabilities than those that had been achieved with standard trap designs. Previous research identified important trap modifications that can increase the probability of snakes entering traps and help prevent the escape of captured snakes. The purpose of this study was to quantify detection and capture probabilities obtained using the most successful modification to commercially available traps to date (2015), and examine the ability of realized detection and capture probabilities to achieve benchmark levels of precision in occupancy and capture-mark-recapture studies.

Development of a novel information and communication technology system to compensate for a sudden shortage of emergency department physicians.

PubMed

Tanaka, Kumiko; Nakada, Taka-Aki; Fukuma, Hiroshi; Nakao, Shota; Masunaga, Naohisa; Tomita, Keisuke; Matsumura, Yosuke; Mizushima, Yasuaki; Matsuoka, Tetsuya

2017-01-23

A sudden shortage of physician resources due to overwhelming patient needs can affect the quality of care in the emergency department (ED). Developing effective response strategies remains a challenging research area. We created a novel system using information and communication technology (ICT) to respond to a sudden shortage, and tested the system to determine whether it would compensate for a shortage. Patients (n = 4890) transferred to a level I trauma center in Japan during 2012-2015 were studied. We assessed whether the system secured the necessary physicians without using other means such as phone or pager, and calculated fulfillment rate by the system as a primary outcome variable. We tested for the difference in probability of multiple casualties among total casualties transferred to the ED as an indicator of ability to respond to excessive patient needs, in a secondary analysis before and after system introduction. The system was activated 24 times (stand-by request [n = 12], attendance request [n = 12]) in 24 months, and secured the necessary physicians without using other means; fulfillment rate was 100%. There was no significant difference in the probability of multiple casualties during daytime weekdays hours before and after system introduction, while the probability of multiple casualties during night or weekend hours after system introduction significantly increased compared to before system introduction (4.8% vs. 12.9%, P < 0.0001). On the whole, the probability of multiple casualties increased more than 2 times after system introduction 6.2% vs. 13.6%, P < 0.0001). After introducing the system, probability of multiple casualties increased. Thus the system may contribute to improvement in the ability to respond to sudden excessive patient needs in multiple causalities. A novel system using ICT successfully secured immediate responses from needed physicians outside the hospital without increasing user workload, and increased the ability to respond to excessive patient needs. The system appears to be able to compensate for a shortage of physician in the ED due to excessive patient transfers, particularly during off-hours.

Can reduction of uncertainties in cervix cancer brachytherapy potentially improve clinical outcome?

PubMed

Nesvacil, Nicole; Tanderup, Kari; Lindegaard, Jacob C; Pötter, Richard; Kirisits, Christian

2016-09-01

The aim of this study was to quantify the impact of different types and magnitudes of dosimetric uncertainties in cervix cancer brachytherapy (BT) on tumour control probability (TCP) and normal tissue complication probability (NTCP) curves. A dose-response simulation study was based on systematic and random dose uncertainties and TCP/NTCP models for CTV and rectum. Large patient cohorts were simulated assuming different levels of dosimetric uncertainties. TCP and NTCP were computed, based on the planned doses, the simulated dose uncertainty, and an underlying TCP/NTCP model. Systematic uncertainties of 3-20% and random uncertainties with a 5-30% standard deviation per BT fraction were analysed. Systematic dose uncertainties of 5% lead to a 1% decrease/increase of TCP/NTCP, while random uncertainties of 10% had negligible impact on the dose-response curve at clinically relevant dose levels for target and OAR. Random OAR dose uncertainties of 30% resulted in an NTCP increase of 3-4% for planned doses of 70-80Gy EQD2. TCP is robust to dosimetric uncertainties when dose prescription is in the more flat region of the dose-response curve at doses >75Gy. For OARs, improved clinical outcome is expected by reduction of uncertainties via sophisticated dose delivery and treatment verification. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cardiorespiratory deconditioning with static and dynamic leg exercise during bed rest

NASA Technical Reports Server (NTRS)

Stremel, R. W.; Convertino, V. A.; Bernauer, E. M.; Greenleaf, J. E.

1976-01-01

Results are presented for an experimental study designed to compare the effects of heavy static and dynamic exercise training during 14 days of bed rest on the cardiorespiratory responses to submaximal and maximal exercise performed by seven healthy men aged 19-22 yr. The parameters measured were submaximal and maximal oxygen uptake, minute ventilation, heart rate, and plasma volume. The results indicate that exercise alone during bed rest reduces but does not eliminate the reduction in maximal oxygen uptake. An additional positive hydrostatic effect is therefore necessary to restore maximal oxygen uptake to ambulatory control levels. The greater protective effect of static exercise on maximal oxygen uptake is probably due to a greater hydrostatic component from the isometric muscular contraction. Neither the static nor the dynamic exercise training regimes are found to minimize the changes in all the variables studied, thereby suggesting a combination of static and dynamic exercises.

Interleukin-11 - its role in the vicious cycle of inflammation, periodontitis and diabetes: A clinicobiochemical cross-sectional study

PubMed Central

Prasad, Rohit; Suchetha, Aganashini; Lakshmi, Puzhankara; Darshan, Mundinamane Basawalingappa; Apoorva, Sokke Mallikarjuna; Ashit, Gulabdas Bharwani

2015-01-01

Context: Interleukin-11 (IL-11) is a multifunctional cytokine with a probable regulatory role in the inflamed periodontal tissue. It has also been shown to inhibit the production of potent proinflammatory cytokines like tumor necrosis factor-alpha, IL-6 and IL-1β in vitro. Type 2 diabetes mellitus, which demonstrates an increase in proinflammatory cytokines, might hypothetically, display a decrease in the levels of IL-11, which down-regulates synthesis of the proinflammatory cytokines. Aims: This clinicobiochemical cross-sectional study was undertaken to try to interpret the link between IL-11, diabetes and periodontitis and to explore the probable protective role of IL-11. Materials and Methods: A total of 90 patients were included in the study and were divided into five groups based on community periodontal index scores and diabetes status. Probing pocket depth and clinical attachment level were measured in all the subjects. Gingival crevicular fluid (GCF) was collected from all the participants using micropipettes and blood samples were collected from subjects in Groups III, IV and V, for analysis of glycated hemoglobin. IL-11 levels were measured in GCF samples by enzyme-linked immunosorbent assay. Statistical Analysis: The data obtained were subjected to statistical analysis. Results: The GCF IL-11 levels decreased from periodontal health to disease and in periodontitis patients with type 2 diabetes with decreasing glycemic control. Conclusions: Interleukin-11 may play an important role in the modulation of immune response via the reduction of proinflammatory cytokine production and periodontal tissue damage. It was seen in this study that IL-11 could be detected in GCF and the levels of IL-11 in GCF decreased progressively from healthy to periodontitis sites. IL-11 levels were significantly lower in chronic periodontitis group when compared to gingivitis group. The decrease in the levels of IL-11 probably indicates that both diabetes and periodontitis may play a synergistic role in the suppression of protective host responses. The potential of IL-11 as a probable biomarker of inflammation in both periodontal disease and diabetes mellitus is indicated by the changeability of IL-11 levels with the change in periodontal disease status and glycemic control. Further longitudinal studies are needed to validate IL-11 as a “biomarker of inflammation” in periodontal disease and diabetes progression and to prove its role in the connecting link between periodontal disease and type 2 diabetes mellitus. PMID:26015665

Cost-effectiveness analysis of early versus non-early intervention in acute migraine based on evidence from the 'Act when Mild' study.

PubMed

Slof, John

2012-05-01

In spite of the important progress made in the abortive treatment of acute migraine episodes since the introduction of triptans, reduction of pain and associated symptoms is in many cases still not as effective nor as fast as would be desirable. Recent research pays more attention to the timing of the treatment, and taking triptans early in the course of an attack when pain is still mild has been found more efficacious than the usual strategy of waiting for the attack to develop to a higher pain intensity level. To investigate the cost effectiveness of early versus non-early intervention with almotriptan in acute migraine. An economic evaluation was conducted from the perspectives of French society and the French public health system based on patient-level data collected in the AwM (Act when Mild) study, a placebo-controlled trial that compared the response to early and non-early treatment of acute migraine with almotriptan. Incremental cost-effectiveness ratios (ICERs) were determined in terms of QALYs, migraine hours and productive time lost. Costs were expressed in Euros (year 2010 values). Bootstrapping was used to derive cost-effectiveness acceptability curves. Early treatment has shown to lead to shorter attack duration, less productive time lost, better quality of life, and is, with 92% probability, overall cost saving from a societal point of view. In terms of drug costs only, however, non-early treatment is less expensive. From the public health system perspective, the (bootstrap) mean ICER of early treatment amounts to €0.38 per migraine hour avoided, €1.29 per hour of productive time lost avoided, and €14,296 per QALY gained. Considering willingness-to-pay values of approximately €1 to avoid an hour of migraine, €10 to avoid the loss of a productive hour, or €30,000 to gain one QALY, the approximate probability that early treatment is cost effective is 90%, 90% and 70%, respectively. These results remain robust in different scenarios for the major elements of the economic evaluation. Compared with non-early treatment, a strategy of early treatment of acute migraine with almotriptan when pain is still mild is, with high probability, cost saving from the French societal perspective and can be considered cost effective from the public health system point of view.

Evidence for a functional cardiac interaction between losartan and angiotensin-(1–7) receptors revealed by orthostatic tilting test in rats

PubMed Central

Matos de Moura, Marina; Augusto Sousa dos Santos, Robson; Antônio Peliky Fontes, Marco

2005-01-01

Studies have shown that the angiotensin II (Ang II) AT1 receptor antagonist, losartan, accentuates the orthostatic hypotensive response in anesthetized rats, and there is evidence indicating that this effect is not exclusively mediated by AT1 receptors. We investigated whether the pronounced orthostatic cardiovascular response observed in losartan-treated rats involves an interference with angiotensin-(1–7) (Ang-(1–7)) receptors. Urethane-anesthetized rats were submitted to orthostatic stress (90° head-up tilt for 2 min). Intravenous injection of losartan (1 mg kg−1, n=9) significantly accentuated the decrease in mean arterial pressure (MAP) induced by head-up tilt (−33±6% after losartan vs −15±8% control tilt). This effect was accompanied by a significant bradycardia (−8±3% after losartan vs −3±3% control tilt). Another AT1 antagonist, candesartan, did not potentiate the decrease of MAP and did not change the cardiac response induced by head-up tilt. Strikingly, administration of the Ang-(1–7) antagonist, A-779 (10 nmol kg−1, n=5), totally reversed the bradicardiac effect caused by losartan and this effect was accompanied by a tendency towards attenuation of the hypotensive response caused by losartan. These findings indicate that the marked orthostatic cardiovascular response is specific for losartan, and that it may be due, in part, to an interaction of this antagonist with Ang-(1–7) receptors, probably at the cardiac level. PMID:15685215

Modulatory Role of Omentin-1 in Inflammation: Cytokines and Dietary Intake.

PubMed

Zabetian-Targhi, Fateme; Mirzaei, Khadijeh; Keshavarz, Seyed Ali; Hossein-Nezhad, Arash

2016-01-01

Obesity is known as a chronic inflammatory state whereby anti-inflammatory adipokines, such as omentin-1 levels, are decreased. The present study aims to determine omentin-1 levels in relation to dietary intake, inflammation, and immune response in healthy obese individuals. A total of 170 obese participants (body mass index [BMI] ≥ 30) were recruited in this cross-sectional study. Body composition was evaluated by a body composition analyzer, and inflammatory markers (high-sensitivity C-reactive protein [hs-CRP], interleukin (IL)-4, IL-6, IL-1β, IL-17, IL-10, IL-13, and tumor necrosis factor-alpha [TNF-α]) were measured by enzyme-linked immunosorbent assay (ELISA) kits. We observed associations between higher serum levels of omentin-1 and lower levels of fasting insulin, glucose, total cholesterol, IL-6, and TNF-α concentrations; higher levels of IL-13, IL-4, and IL-1β were associated with higher serum levels of omentin-1 (all p < 0.05). Omentin-1 levels were not associated with IL-10, hs-CRP, and IL-17 concentrations. We also observed associations between higher intake of saturated fatty acid (SFA) and omentin-1 levels, even after adjustment for total energy intake (p = 0.04). Women with low intake of SFA had higher levels of omentin-1 (p = 0.03); a similar relation was not observed in men. Omentin-1 has an anti-inflammatory role in obesity and exerts its effects probably by inducing an increase in Th-2 cytokines comprising IL-13 and IL-4. Omentin-1 is not related to IL-17, a regulatory T cell cytokine, which modulates T helper balance. Levels of inflammatory cytokines are decreased in higher concentrations of omentin-1, except IL-1β. Lower intake of SFA may modify omentin-1 levels in women. Our study demonstrated the probable protective role of omentin-1 in obesity-related inflammation and insulin resistance.

Effect of noopept and afobazole on the development of neurosis of learned helplessness in rats.

PubMed

Uyanaev, A A; Fisenko, V P; Khitrov, N K

2003-08-01

We studied the effects of new psychotropic preparations noopept and afobazole on acquisition of the conditioned active avoidance response and development of neurosis of learned helplessness in rats. Noopept in doses of 0.05-0.10 mg/kg accelerated acquisition of conditioned active avoidance response and reduced the incidence of learned helplessness in rats. Afobazole in a dose of 5 mg/kg produced an opposite effect, which is probably related to high selective anxiolytic activity of this preparation.

Performance-based seismic assessment of skewed bridges with and without considering soil-foundation interaction effects for various site classes

NASA Astrophysics Data System (ADS)

Ghotbi, Abdoul R.

2014-09-01

The seismic behavior of skewed bridges has not been well studied compared to straight bridges. Skewed bridges have shown extensive damage, especially due to deck rotation, shear keys failure, abutment unseating and column-bent drift. This research, therefore, aims to study the behavior of skewed and straight highway overpass bridges both with and without taking into account the effects of Soil-Structure Interaction (SSI) due to near-fault ground motions. Due to several sources of uncertainty associated with the ground motions, soil and structure, a probabilistic approach is needed. Thus, a probabilistic methodology similar to the one developed by the Pacific Earthquake Engineering Research Center (PEER) has been utilized to assess the probability of damage due to various levels of shaking using appropriate intensity measures with minimum dispersions. The probabilistic analyses were performed for various bridge configurations and site conditions, including sand ranging from loose to dense and clay ranging from soft to stiff, in order to evaluate the effects. The results proved a considerable susceptibility of skewed bridges to deck rotation and shear keys displacement. It was also found that SSI had a decreasing effect on the damage probability for various demands compared to the fixed-base model without including SSI. However, deck rotation for all types of the soil and also abutment unseating for very loose sand and soft clay showed an increase in damage probability compared to the fixed-base model. The damage probability for various demands has also been found to decrease with an increase of soil strength for both sandy and clayey sites. With respect to the variations in the skew angle, an increase in skew angle has had an increasing effect on the amplitude of the seismic response for various demands. Deck rotation has been very sensitive to the increase in the skew angle; therefore, as the skew angle increased, the deck rotation responded accordingly. Furthermore, abutment unseating showed an increasing trend due to an increase in skew angle for both fixed-base and SSI models.

Cardiovascular and organ responses and adaptation responses to hypogravity in an experimental animal model.

NASA Astrophysics Data System (ADS)

Biondi, R.; Capodicasa, E.; Tassi, C.; Mezzasomal, L.; Benedetti, C.; Valiani, M.; Marconi, P.; Rossi, R.

1995-10-01

The head-down suspension (i.e antiorthostatic hypokinesia) rat is used to simulate weightlessness. However, little is known about cardiovascular and organ adaptation responses which, over a long time, can become pathologically significant. The purpose of this study was therefore to evaluate regional changes in the hematology parameters, Endotheline-1 (ET-1) concentration and urinary excretion of N-acetyl-β-D-glucosaminidase (EC 3.2.1.30) (NAG) in an experimental antiorthostatic rat model. The data indicate significant variations in the plasma ET-1 level in time, in the superior and inferior cava vessel blood of animals maintained for 10 days in hypogravity with respect to controls. These changes do not seem to be due to hemoconcentration. The increase in urinary NAG was observed during the first 24h of experiment, indicating renal stress, probably due to adverse blood flow variations within the organ. We conclude that the plasma ET-1 level changes could be responsible, overall for the blood flow variations in the kidney and renal stress could be the consequence of extended antiorthostatic hypokinesia. The ET-1 behaviour and urinary NAG excretion in rats exposed to antiorthostatic hypokjnetic hydynamia offer possibilities for understanding if these changes might be reversible or when they become pathological. This could give some relevant information about the effects of prolonged hypogravity during the space voyage.

Long acting propranolol and HSP-70 rich tumor lysate reduce tumor growth and enhance immune response against fibrosarcoma in Balb/c mice.

PubMed

Khalili, Ahmad; Hassan, Zuhair Muhammad; Shahabi, Shahram; Pourfathollah, Ali Akbar; Ostad, Seyed Nasser; Noori, Shokoofe; Mahdavi, Mehdi; Haybar, Habib; Langroudi, Ladan

2013-06-01

Noradrenaline (NA), the principal neurotransmitter released from sympathetic nerve terminals, influences T-cell maturation, not only directly in developing T cells, but also indirectly, by acting on the thymic nonlymphoid cells. In vitro and in vivo studies have demonstrated the anti-proliferative, anti-migratory, anti-angiogenic and cytotoxic properties of propranolol, β-AR blocker, against various cancers. To evaluate the effect of propranolol on efficacy of HSP-70 rich lysate vaccine in immunotherapy of fibrosarcoma. Mouse fibrosarcoma WEHI-164 cells were used to immunize tumor-bearing mice with or without propranolol and HSP-70. Splenocytes proliferation, cytotoxicity activity of the splenocytes, naturally occurring CD4+ CD25high T-reg cells and IFN-γ and IL-4 secretion as well as tumor size, were assessed to describe the anti-tumor immune response. A significant increase in the level of IFN-γ in the mice vaccinated with WEHI-164 cells enriched with HSP-70 and co-treated with propranolol was observed compared to controls. However, HSP enrichment or propranolol treatment alone did not enhance the immune response as measured by the level of IFN-γ. Likewise, a decrease in tumor growth in the test group (p<0.01) and a significant increase in CTL activity (p<0.05) was observed. HSP enriched vaccine shows anti-tumor activity, probably due to the modulation of immune responses.

Theoretical Study of Energy Levels and Transition Probabilities of Boron Atom

NASA Astrophysics Data System (ADS)

Tian Yi, Zhang; Neng Wu, Zheng

2009-08-01

Full Text PDF Though the electrons configuration for boron atom is simple and boron atom has long been of interest for many researchers, the theoretical studies for properties of BI are not systematic, there are only few results reported on energy levels of high excited states of boron, and transition measurements are generally restricted to transitions involving ground states and low excited states without considering fine structure effects, provided only multiplet results, values for transitions between high excited states are seldom performed. In this article, by using the scheme of the weakest bound electron potential model theory calculations for energy levels of five series are performed and with the same method we give the transition probabilities between excited states with considering fine structure effects. The comprehensive set of calculations attempted in this paper could be of some value to workers in the field because of the lack of published calculations for the BI systems. The perturbations coming from foreign perturbers are taken into account in studying the energy levels. Good agreement between our results and the accepted values taken from NIST has been obtained. We also reported some values of energy levels and transition probabilities not existing on the NIST data bases.

The response analysis of fractional-order stochastic system via generalized cell mapping method.

PubMed

Wang, Liang; Xue, Lili; Sun, Chunyan; Yue, Xiaole; Xu, Wei

2018-01-01

This paper is concerned with the response of a fractional-order stochastic system. The short memory principle is introduced to ensure that the response of the system is a Markov process. The generalized cell mapping method is applied to display the global dynamics of the noise-free system, such as attractors, basins of attraction, basin boundary, saddle, and invariant manifolds. The stochastic generalized cell mapping method is employed to obtain the evolutionary process of probability density functions of the response. The fractional-order ϕ 6 oscillator and the fractional-order smooth and discontinuous oscillator are taken as examples to give the implementations of our strategies. Studies have shown that the evolutionary direction of the probability density function of the fractional-order stochastic system is consistent with the unstable manifold. The effectiveness of the method is confirmed using Monte Carlo results.

Stochastic response and bifurcation of periodically driven nonlinear oscillators by the generalized cell mapping method

NASA Astrophysics Data System (ADS)

Han, Qun; Xu, Wei; Sun, Jian-Qiao

2016-09-01

The stochastic response of nonlinear oscillators under periodic and Gaussian white noise excitations is studied with the generalized cell mapping based on short-time Gaussian approximation (GCM/STGA) method. The solutions of the transition probability density functions over a small fraction of the period are constructed by the STGA scheme in order to construct the GCM over one complete period. Both the transient and steady-state probability density functions (PDFs) of a smooth and discontinuous (SD) oscillator are computed to illustrate the application of the method. The accuracy of the results is verified by direct Monte Carlo simulations. The transient responses show the evolution of the PDFs from being Gaussian to non-Gaussian. The effect of a chaotic saddle on the stochastic response is also studied. The stochastic P-bifurcation in terms of the steady-state PDFs occurs with the decrease of the smoothness parameter, which corresponds to the deterministic pitchfork bifurcation.

"I Don't Really Understand Probability at All": Final Year Pre-Service Teachers' Understanding of Probability

ERIC Educational Resources Information Center

Maher, Nicole; Muir, Tracey

2014-01-01

This paper reports on one aspect of a wider study that investigated a selection of final year pre-service primary teachers' responses to four probability tasks. The tasks focused on foundational ideas of probability including sample space, independence, variation and expectation. Responses suggested that strongly held intuitions appeared to…

Molecular effectors in the chronic exposure to arsenic as early and sensitive biomarkers in developing Rhinella arenarum toads.

PubMed

Mardirosian, Mariana Noelia; Ceschin, Danilo Guillermo; Lascano, Cecilia Inés; Venturino, Andrés

2017-05-01

Arsenic, a natural element of ecological relevance, is one of the most toxic elements present in various regions of the world. It can be found in natural water sources throughout Argentina in concentrations between 0.01 and 15mgL -1 . The Argentinean autochthonous toad Rhinella arenarum was selected to study the molecular mechanisms involved in the effects and response to the chronic As exposure along its embryonic and larval development. We evaluated the effects on MAPK signal transduction pathway and transcription factors c-FOS and c-JUN, and the regulation of the expression at protein levels of different antioxidant enzymes. Our results indicated that As is modulating the MAPK pathway, increasing MEK and ERK levels both in the nuclear and post-nuclear fraction along the embryonic development and mainly at the beginning of the larval stage. Through this pathway, As can upregulate transcription factors like c-FOS and c-JUN, impacting the antioxidant response of the exposed embryos and larvae through antioxidant enzymes and recycling of GSH. Arsenic triggered specifically the synthesis of antioxidant enzymes in exposed R. arenarum embryo and larvae. In particular, the expression levels of SOD, CAT and GST enzymes analyzed by Western blot showed a similar behavior to their enzymatic activities in our previous work. This fact suggests that not only the synthesis of these antioxidant enzymes but also their rapid degradation after inactivation would be regulated in response to ROS levels. Antioxidant enzymes may show dual responses of induction and inactivation followed by degradation depending on the levels of oxidative stress and impact on ROS targets when the exposure is sustained in time and intensity. We also performed a probability of exceedence analysis including our previous results to visualize a progression of the response in time and also established the best early-responding biomarkers at the lowest As concentrations. As a conclusion, the molecular biomarkers such as the MAPKs MEK and ERK and transcription factors c-FOS and c-JUN are early induced in the response of developing toad embryos exposed to very low As concentrations in water. The advantage of counting with molecular biomarkers early responding to low concentrations of As in a chronic exposure is that they may anticipate the irreversible damage at later developmental stages due to the constant oxidative challenge. Copyright © 2017 Elsevier B.V. All rights reserved.

The effects of recall errors and of selection bias in epidemiologic studies of mobile phone use and cancer risk.

PubMed

Vrijheid, Martine; Deltour, Isabelle; Krewski, Daniel; Sanchez, Marie; Cardis, Elisabeth

2006-07-01

This paper examines the effects of systematic and random errors in recall and of selection bias in case-control studies of mobile phone use and cancer. These sensitivity analyses are based on Monte-Carlo computer simulations and were carried out within the INTERPHONE Study, an international collaborative case-control study in 13 countries. Recall error scenarios simulated plausible values of random and systematic, non-differential and differential recall errors in amount of mobile phone use reported by study subjects. Plausible values for the recall error were obtained from validation studies. Selection bias scenarios assumed varying selection probabilities for cases and controls, mobile phone users, and non-users. Where possible these selection probabilities were based on existing information from non-respondents in INTERPHONE. Simulations used exposure distributions based on existing INTERPHONE data and assumed varying levels of the true risk of brain cancer related to mobile phone use. Results suggest that random recall errors of plausible levels can lead to a large underestimation in the risk of brain cancer associated with mobile phone use. Random errors were found to have larger impact than plausible systematic errors. Differential errors in recall had very little additional impact in the presence of large random errors. Selection bias resulting from underselection of unexposed controls led to J-shaped exposure-response patterns, with risk apparently decreasing at low to moderate exposure levels. The present results, in conjunction with those of the validation studies conducted within the INTERPHONE study, will play an important role in the interpretation of existing and future case-control studies of mobile phone use and cancer risk, including the INTERPHONE study.

Integrating community-based verbal autopsy into civil registration and vital statistics (CRVS): system-level considerations

PubMed Central

de Savigny, Don; Riley, Ian; Chandramohan, Daniel; Odhiambo, Frank; Nichols, Erin; Notzon, Sam; AbouZahr, Carla; Mitra, Raj; Cobos Muñoz, Daniel; Firth, Sonja; Maire, Nicolas; Sankoh, Osman; Bronson, Gay; Setel, Philip; Byass, Peter; Jakob, Robert; Boerma, Ties; Lopez, Alan D.

2017-01-01

ABSTRACT Background: Reliable and representative cause of death (COD) statistics are essential to inform public health policy, respond to emerging health needs, and document progress towards Sustainable Development Goals. However, less than one-third of deaths worldwide are assigned a cause. Civil registration and vital statistics (CRVS) systems in low- and lower-middle-income countries are failing to provide timely, complete and accurate vital statistics, and it will still be some time before they can provide physician-certified COD for every death. Proposals: Verbal autopsy (VA) is a method to ascertain the probable COD and, although imperfect, it is the best alternative in the absence of medical certification. There is extensive experience with VA in research settings but only a few examples of its use on a large scale. Data collection using electronic questionnaires on mobile devices and computer algorithms to analyse responses and estimate probable COD have increased the potential for VA to be routinely applied in CRVS systems. However, a number of CRVS and health system integration issues should be considered in planning, piloting and implementing a system-wide intervention such as VA. These include addressing the multiplicity of stakeholders and sub-systems involved, integration with existing CRVS work processes and information flows, linking VA results to civil registration records, information technology requirements and data quality assurance. Conclusions: Integrating VA within CRVS systems is not simply a technical undertaking. It will have profound system-wide effects that should be carefully considered when planning for an effective implementation. This paper identifies and discusses the major system-level issues and emerging practices, provides a planning checklist of system-level considerations and proposes an overview for how VA can be integrated into routine CRVS systems. PMID:28137194

DISRUPTIVE EFFECTS OF CONTINGENT FOOD ON HIGH-PROBABILITY BEHAVIOR

PubMed Central

Frank-Crawford, Michelle A; Borrero, John C; Nguyen, Linda; Leon-Enriquez, Yanerys; Carreau-Webster, Abbey B; DeLeon, Iser G

2012-01-01

The delivery of food contingent on 10 s of consecutive toy engagement resulted in a decrease in engagement and a corresponding increase in other responses that had been previously reinforced with food. Similar effects were not observed when tokens exchangeable for the same food were delivered, suggesting that engagement was disrupted by the contingent provision of the food, which may have functioned as a discriminative stimulus that occasioned competing responses. PMID:22403457

Probability shapes perceptual precision: A study in orientation estimation.

PubMed

Jabar, Syaheed B; Anderson, Britt

2015-12-01

Probability is known to affect perceptual estimations, but an understanding of mechanisms is lacking. Moving beyond binary classification tasks, we had naive participants report the orientation of briefly viewed gratings where we systematically manipulated contingent probability. Participants rapidly developed faster and more precise estimations for high-probability tilts. The shapes of their error distributions, as indexed by a kurtosis measure, also showed a distortion from Gaussian. This kurtosis metric was robust, capturing probability effects that were graded, contextual, and varying as a function of stimulus orientation. Our data can be understood as a probability-induced reduction in the variability or "shape" of estimation errors, as would be expected if probability affects the perceptual representations. As probability manipulations are an implicit component of many endogenous cuing paradigms, changes at the perceptual level could account for changes in performance that might have traditionally been ascribed to "attention." (c) 2015 APA, all rights reserved).

Responses of male cricket frogs (Acris crepitans) to attenuated and degraded advertisement calls.

PubMed

Venator, Kurt R; Ryan, Michael J; Wilczynski, Walter

2017-05-01

We examined the vocal and non-vocal responses of male cricket frogs ( Acris crepitans ) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (AM). Both are characteristic of changes to the call as it is transmitted through natural habitats. As stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indicative of increased aggressive interactions. At the higher intensities and lower degradation levels, the probability that males would shift to one of two non-vocal behavioral responses, attacking the perceived intruder or ceasing calling and abandoning the call site, gradually increased. The results show that differences in signal attenuation and AM degradation levels are perceived by males and trigger both vocal and non-vocal behavioral responses consistent with their use in evaluating the distance to a challenging male. Furthermore, the results indicate that the male responses are graded, increasing as intensity rises and degradation falls, and hierarchical, with vocal responses preceding behavioral responses over the range of intensities and degradation levels presented.

Responses of male cricket frogs (Acris crepitans) to attenuated and degraded advertisement calls

PubMed Central

Venator, Kurt R.; Ryan, Michael J.; Wilczynski, Walter

2017-01-01

We examined the vocal and non-vocal responses of male cricket frogs (Acris crepitans) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (AM). Both are characteristic of changes to the call as it is transmitted through natural habitats. As stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indicative of increased aggressive interactions. At the higher intensities and lower degradation levels, the probability that males would shift to one of two non-vocal behavioral responses, attacking the perceived intruder or ceasing calling and abandoning the call site, gradually increased. The results show that differences in signal attenuation and AM degradation levels are perceived by males and trigger both vocal and non-vocal behavioral responses consistent with their use in evaluating the distance to a challenging male. Furthermore, the results indicate that the male responses are graded, increasing as intensity rises and degradation falls, and hierarchical, with vocal responses preceding behavioral responses over the range of intensities and degradation levels presented. PMID:28966421

The effect of lead intoxication on endocrine functions.

PubMed

Doumouchtsis, K K; Doumouchtsis, S K; Doumouchtsis, E K; Perrea, D N

2009-02-01

Studies on the effects of lead on the endocrine system are mainly based on occupationally lead-exposed workers and experimental animal models. Although evidence is conflicting, it has been reported that accumulation of lead affects the majority of the endocrine glands. In particular, it appears to have an effect on the hypothalamic-pituitary axis causing blunted TSH, GH, and FSH/LH responses to TRH, GHRH, and GnRH stimulation, respectively. Suppressed GH release has been reported, probably caused by reduced synthesis of GHRH, inhibition of GHRH release or reduced somatotrope responsiveness. Higher levels of PRL in lead intoxication have been reported. In short-term lead-exposed individuals, high LH and FSH levels are usually associated to normal testosterone concentrations, whereas in long-term exposed individuals' low testosterone levels do not induce high LH and FSH concentrations. These findings suggest that lead initially causes some subclinical testicular damage, followed by hypothalamic or pituitary disturbance when longer periods of exposure take place. Similarly, lead accumulates in granulosa cells of the ovary, causing delays in growth and pubertal development and reduced fertility in females. In the parenchyma of adrenals histological and cytological changes are demonstrated, causing changes in plasma basal and stress-mediated corticosterone concentrations and reduced cytosolic and nuclear glucocorticoid receptor binding. Thyroid hormone kinetics are also affected. Central defect of the thyroid axis or an alteration in T4 metabolism or binding to proteins may be involved in derangements in thyroid hormone action. Lead toxicity involves alterations on calcitropic hormones' homeostasis, which increase the risk of skeletal disorders.

Antioxidant defence and stress protein induction following heat stress in the Mediterranean snail Xeropicta derbentina.

PubMed

Troschinski, Sandra; Dieterich, Andreas; Krais, Stefanie; Triebskorn, Rita; Köhler, Heinz-R

2014-12-15

The Mediterranean snail Xeropicta derbentina (Pulmonata, Hygromiidae), being highly abundant in Southern France, has the need for efficient physiological adaptations to desiccation and over-heating posed by dry and hot environmental conditions. As a consequence of heat, oxidative stress manifests in these organisms, which, in turn, leads to the formation of reactive oxygen species (ROS). In this study, we focused on adaptations at the biochemical level by investigation of antioxidant defences and heat shock protein 70 (Hsp70) induction, both essential mechanisms of the heat stress response. We exposed snails to elevated temperature (25, 38, 40, 43 and 45°C) in the laboratory and measured the activity of the antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), determined the Hsp70 level and quantified lipid peroxidation. In general, we found a high constitutive level of CAT activity in all treatments, which may be interpreted as a permanent protection against ROS, i.e. hydrogen peroxide. CAT and GPx showed temperature-dependent activity: CAT activity was significantly increased in response to high temperatures (43 and 45°C), whereas GPx exhibited a significantly increased activity at 40°C, probably in response to high levels of lipid peroxides that occurred in the 38°C treatment. Hsp70 showed a maximum induction at 40°C, followed by a decrease at higher temperatures. Our results reveal that X. derbentina possesses a set of efficient mechanisms to cope with the damaging effects of heat. Furthermore, we demonstrated that, besides the well-documented Hsp70 stress response, antioxidant defence plays a crucial role in the snails' competence to survive extreme temperatures. © 2014. Published by The Company of Biologists Ltd.

An alternative empirical likelihood method in missing response problems and causal inference.

PubMed

Ren, Kaili; Drummond, Christopher A; Brewster, Pamela S; Haller, Steven T; Tian, Jiang; Cooper, Christopher J; Zhang, Biao

2016-11-30

Missing responses are common problems in medical, social, and economic studies. When responses are missing at random, a complete case data analysis may result in biases. A popular debias method is inverse probability weighting proposed by Horvitz and Thompson. To improve efficiency, Robins et al. proposed an augmented inverse probability weighting method. The augmented inverse probability weighting estimator has a double-robustness property and achieves the semiparametric efficiency lower bound when the regression model and propensity score model are both correctly specified. In this paper, we introduce an empirical likelihood-based estimator as an alternative to Qin and Zhang (2007). Our proposed estimator is also doubly robust and locally efficient. Simulation results show that the proposed estimator has better performance when the propensity score is correctly modeled. Moreover, the proposed method can be applied in the estimation of average treatment effect in observational causal inferences. Finally, we apply our method to an observational study of smoking, using data from the Cardiovascular Outcomes in Renal Atherosclerotic Lesions clinical trial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Probability assessment with response times and confidence in perception and knowledge.

PubMed

Petrusic, William M; Baranski, Joseph V

2009-02-01

In both a perceptual and a general knowledge comparison task, participants categorized the time they took to decide, selecting one of six categories ordered from "Slow" to Fast". Subsequently, they rated confidence on a six-category scale ranging from "50%" to "100%". Participants were able to accurately scale their response times thus enabling the treatment of the response time (RT) categories as potential confidence categories. Probability assessment analyses of RTs revealed indices of over/underconfidence, calibration, and resolution, each subject to the "hard-easy" effect, comparable to those obtained with the actual confidence ratings. However, in both the perceptual and knowledge domains, resolution (i.e., the ability to use the confidence categories to distinguish correct from incorrect decisions) was significantly better with confidence ratings than with RT categorization. Generally, comparable results were obtained with scaling of the objective RTs, although subjective categorization of RTs provided probability assessment indices superior to those obtained from objective RTs. Taken together, the findings do not support the view that confidence arises from a scaling of decision time.

A White Paper on Global Wheat Health Based on Scenario Development and Analysis.

PubMed

Savary, S; Djurle, A; Yuen, J; Ficke, A; Rossi, V; Esker, P D; Fernandes, J M C; Del Ponte, E M; Kumar, J; Madden, L V; Paul, P; McRoberts, N; Singh, P K; Huber, L; Pope de Vallavielle, C; Saint-Jean, S; Willocquet, L

2017-10-01

Scenario analysis constitutes a useful approach to synthesize knowledge and derive hypotheses in the case of complex systems that are documented with mainly qualitative or very diverse information. In this article, a framework for scenario analysis is designed and then, applied to global wheat health within a timeframe from today to 2050. Scenario analysis entails the choice of settings, the definition of scenarios of change, and the analysis of outcomes of these scenarios in the chosen settings. Three idealized agrosystems, representing a large fraction of the global diversity of wheat-based agrosystems, are considered, which represent the settings of the analysis. Several components of global changes are considered in their consequences on global wheat health: climate change and climate variability, nitrogen fertilizer use, tillage, crop rotation, pesticide use, and the deployment of host plant resistances. Each idealized agrosystem is associated with a scenario of change that considers first, a production situation and its dynamics, and second, the impacts of the evolving production situation on the evolution of crop health. Crop health is represented by six functional groups of wheat pathogens: the pathogens associated with Fusarium head blight; biotrophic fungi, Septoria-like fungi, necrotrophic fungi, soilborne pathogens, and insect-transmitted viruses. The analysis of scenario outcomes is conducted along a risk-analytical pattern, which involves risk probabilities represented by categorized probability levels of disease epidemics, and risk magnitudes represented by categorized levels of crop losses resulting from these levels of epidemics within each production situation. The results from this scenario analysis suggest an overall increase of risk probabilities and magnitudes in the three idealized agrosystems. Changes in risk probability or magnitude however vary with the agrosystem and the functional groups of pathogens. We discuss the effects of global changes on the six functional groups, in terms of their epidemiology and of the crop losses they cause. Scenario analysis enables qualitative analysis of complex systems, such as plant pathosystems that are evolving in response to global changes, including climate change and technology shifts. It also provides a useful framework for quantitative simulation modeling analysis for plant disease epidemiology.

Fear, threat and efficacy in threat appeals: message involvement as a key mediator to message acceptance.

PubMed

Cauberghe, Verolien; De Pelsmacker, Patrick; Janssens, Wim; Dens, Nathalie

2009-03-01

In a sample of 170 youngsters, the effect of two versions of a public service announcement (PSA) threat appeal against speeding, placed in four different contexts, on evoked fear, perceived threat (severity and probability of occurrence), perceived response efficacy and self-efficacy, message involvement and anti-speeding attitude and anti-speeding intention is investigated. Evoked fear and perceived threat and efficacy independently influence message involvement. Message involvement is a full mediator between evoked fear, perceived threat and efficacy perception on the one hand, and attitudes towards the message and behavioral intention to accept the message on the other. Speeding experience has a significantly negative impact on anti-speeding attitudes. Message and medium context threat levels and context thematic congruency have a significant effect on evoked fear and to a lesser extent on perceived threat.

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Impacts of forest fragmentation on species richness: a hierarchical approach to community modelling

USGS Publications Warehouse

Zipkin, Elise F.; DeWan, Amielle; Royle, J. Andrew

2009-01-01

1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for which survey data are often sparse. 2. Recent developments have allowed for improved inference about community structure based on species-specific models of occurrence probability, integrated within a hierarchical modelling framework. This framework offers advantages to inference about species richness over typical approaches by accounting for both species-level effects and the aggregated effects of landscape composition on a community as a whole, thus leading to increased precision in estimates of species richness by improving occupancy estimates for all species, including those that were observed infrequently. 3. We developed a hierarchical model to assess the community response of breeding birds in the Hudson River Valley, New York, to habitat fragmentation and analysed the model using a Bayesian approach. 4. The model was designed to estimate species-specific occurrence and the effects of fragment area and edge (as measured through the perimeter and the perimeter/area ratio, P/A), while accounting for imperfect detection of species. 5. We used the fitted model to make predictions of species richness within forest fragments of variable morphology. The model revealed that species richness of the observed bird community was maximized in small forest fragments with a high P/A. However, the number of forest interior species, a subset of the community with high conservation value, was maximized in large fragments with low P/A. 6. Synthesis and applications. Our results demonstrate the importance of understanding the responses of both individual, and groups of species, to environmental heterogeneity while illustrating the utility of hierarchical models for inference about species richness for conservation. This framework can be used to investigate the impacts of land-use change and fragmentation on species or assemblage richness, and to further understand trade-offs in species-specific occupancy probabilities associated with landscape variability.

The Best of Two Open Worlds at the National Open University of Nigeria

ERIC Educational Resources Information Center

Agbu, Jane-frances Obiageli; Mulder, Fred; de Vries, Fred; Tenebe, Vincent; Caine, Abel

2016-01-01

It will be wise for educational institutions, from primary to tertiary level, globally, to reflect on their position and profile with respect to the new concepts of Open Educational Resources (OER) and Massive Open Online Courses (MOOCs). Responses will be diverse of course but the potential is so manifest that many institutions probably will…

Statistics of peak overpressure and shock steepness for linear and nonlinear N-wave propagation in a kinematic turbulence.

PubMed

Yuldashev, Petr V; Ollivier, Sébastien; Karzova, Maria M; Khokhlova, Vera A; Blanc-Benon, Philippe

2017-12-01

Linear and nonlinear propagation of high amplitude acoustic pulses through a turbulent layer in air is investigated using a two-dimensional KZK-type (Khokhlov-Zabolotskaya-Kuznetsov) equation. Initial waves are symmetrical N-waves with shock fronts of finite width. A modified von Kármán spectrum model is used to generate random wind velocity fluctuations associated with the turbulence. Physical parameters in simulations correspond to previous laboratory scale experiments where N-waves with 1.4 cm wavelength propagated through a turbulence layer with the outer scale of about 16 cm. Mean value and standard deviation of peak overpressure and shock steepness, as well as cumulative probabilities to observe amplified peak overpressure and shock steepness, are analyzed. Nonlinear propagation effects are shown to enhance pressure level in random foci for moderate initial amplitudes of N-waves thus increasing the probability to observe highly peaked waveforms. Saturation of the pressure level is observed for stronger nonlinear effects. It is shown that in the linear propagation regime, the turbulence mainly leads to the smearing of shock fronts, thus decreasing the probability to observe high values of steepness, whereas nonlinear effects dramatically increase the probability to observe steep shocks.

Health Professionals Prefer to Communicate Risk-Related Numerical Information Using "1-in-X" Ratios.

PubMed

Sirota, Miroslav; Juanchich, Marie; Petrova, Dafina; Garcia-Retamero, Rocio; Walasek, Lukasz; Bhatia, Sudeep

2018-04-01

Previous research has shown that format effects, such as the "1-in-X" effect-whereby "1-in-X" ratios lead to a higher perceived probability than "N-in-N*X" ratios-alter perceptions of medical probabilities. We do not know, however, how prevalent this effect is in practice; i.e., how often health professionals use the "1-in-X" ratio. We assembled 4 different sources of evidence, involving experimental work and corpus studies, to examine the use of "1-in-X" and other numerical formats quantifying probability. Our results revealed that the use of the "1-in-X" ratio is prevalent and that health professionals prefer this format compared with other numerical formats (i.e., the "N-in-N*X", %, and decimal formats). In Study 1, UK family physicians preferred to communicate prenatal risk using a "1-in-X" ratio (80.4%, n = 131) across different risk levels and regardless of patients' numeracy levels. In Study 2, a sample from the UK adult population ( n = 203) reported that most GPs (60.6%) preferred to use "1-in-X" ratios compared with other formats. In Study 3, "1-in-X" ratios were the most commonly used format in a set of randomly sampled drug leaflets describing the risk of side effects (100%, n = 94). In Study 4, the "1-in-X" format was the most commonly used numerical expression of medical probabilities or frequencies on the UK's NHS website (45.7%, n = 2,469 sentences). The prevalent use of "1-in-X" ratios magnifies the chances of increased subjective probability. Further research should establish clinical significance of the "1-in-X" effect.

Across-channel interference in intensity discrimination: The role of practice and listening strategy

PubMed Central

Buss, Emily

2008-01-01

Pure tone intensity discrimination thresholds can be elevated by the introduction of remote maskers with roved level. This effect is on the order of 10 dB [10log(ΔI/I)] in some conditions and can be demonstrated under conditions of little or no energetic masking. The current study examined the effect of practice and observer strategy on this phenomenon. Experiment 1 included observers who had no formal experience with intensity discrimination and provided training over six hours on a single masked intensity discrimination task to assess learning effects. Thresholds fell with practice for most observers, with significant improvements in 6 out of 8 cases. Despite these improvements significant masking remained in all cases. The second experiment assessed trial-by-trial effects of roved masker level. Conditional probability of a ‘signal-present’ response as a function of the rove value assigned to each of the two masker tones indicates fundamental differences among observers’ processing strategies, even after six hours of practice. The variability in error patterns across practiced listeners suggests that observers approach the task differently, though this variability does not appear to be related to sensitivity. PMID:18177156

Modeling Spatial Dependence of Rainfall Extremes Across Multiple Durations

NASA Astrophysics Data System (ADS)

Le, Phuong Dong; Leonard, Michael; Westra, Seth

2018-03-01

Determining the probability of a flood event in a catchment given that another flood has occurred in a nearby catchment is useful in the design of infrastructure such as road networks that have multiple river crossings. These conditional flood probabilities can be estimated by calculating conditional probabilities of extreme rainfall and then transforming rainfall to runoff through a hydrologic model. Each catchment's hydrological response times are unlikely to be the same, so in order to estimate these conditional probabilities one must consider the dependence of extreme rainfall both across space and across critical storm durations. To represent these types of dependence, this study proposes a new approach for combining extreme rainfall across different durations within a spatial extreme value model using max-stable process theory. This is achieved in a stepwise manner. The first step defines a set of common parameters for the marginal distributions across multiple durations. The parameters are then spatially interpolated to develop a spatial field. Storm-level dependence is represented through the max-stable process for rainfall extremes across different durations. The dependence model shows a reasonable fit between the observed pairwise extremal coefficients and the theoretical pairwise extremal coefficient function across all durations. The study demonstrates how the approach can be applied to develop conditional maps of the return period and return level across different durations.

Aluminum exposure for one hour decreases vascular reactivity in conductance and resistance arteries in rats

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

Schmidt, Patrícia Medeiros; Escobar, Alyne Goulart

Aims: Aluminum (Al) is an important environmental contaminant; however, there are not enough evidences of Al-induced cardiovascular dysfunction. We investigated the effects of acute exposure to aluminum chloride (AlCl{sub 3}) on blood pressure, vascular reactivity and oxidative stress. Methods and results: Male Wistar rats were divided into two groups: Untreated: vehicle (ultrapure water, ip) and AlCl{sub 3}: single dose of AlCl{sub 3} (100 mg/kg,ip). Concentration-response curves to phenylephrine in the absence and presence of endothelium, the nitric oxide synthase inhibitor L-NAME, the potassium channel blocker tetraethylammonium, and the NADPH oxidase inhibitor apocynin were performed in segments from aortic and mesentericmore » resistance arteries. NO released was assessed in aorta and reactive oxygen species (ROS), malondialdehyde, non-protein thiol levels, antioxidant capacity and enzymatic antioxidant activities were investigated in plasma, aorta and/or mesenteric arteries. After one hour of AlCl{sub 3} exposure serum Al levels attained 147.7 ± 25.0 μg/L. Al treatment: 1) did not affect blood pressure, heart rate and vasodilator responses induced by acetylcholine or sodium nitroprusside; 2) decreased phenylephrine-induced vasoconstrictor responses; 3) increased endothelial modulation of contractile responses, NO release and vascular ROS production from NADPH oxidase; 4) increased plasmatic, aortic and mesenteric malondialdehyde and ROS production, and 5) decreased antioxidant capacity and affected the antioxidant biomarkers non-protein thiol levels, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymatic activities. Conclusion: AlCl{sub 3}-acute exposure reduces vascular reactivity. This effect is associated with increased NO production, probably acting on K{sup +} channels, which seems to occur as a compensatory mechanism against Al-induced oxidative stress. Our results suggest that Al exerts toxic effects to the vascular system. - Highlights: • One hour of aluminum exposure decreases vascular reactivity. • Vascular imbalance after aluminum exposure is related to increased oxidative stress. • Enhanced NO release is the first step against the effects of Al at vascular system.« less

The relationship between species detection probability and local extinction probability

USGS Publications Warehouse

Alpizar-Jara, R.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Pollock, K.H.; Rosenberry, C.S.

2004-01-01

In community-level ecological studies, generally not all species present in sampled areas are detected. Many authors have proposed the use of estimation methods that allow detection probabilities that are < 1 and that are heterogeneous among species. These methods can also be used to estimate community-dynamic parameters such as species local extinction probability and turnover rates (Nichols et al. Ecol Appl 8:1213-1225; Conserv Biol 12:1390-1398). Here, we present an ad hoc approach to estimating community-level vital rates in the presence of joint heterogeneity of detection probabilities and vital rates. The method consists of partitioning the number of species into two groups using the detection frequencies and then estimating vital rates (e.g., local extinction probabilities) for each group. Estimators from each group are combined in a weighted estimator of vital rates that accounts for the effect of heterogeneity. Using data from the North American Breeding Bird Survey, we computed such estimates and tested the hypothesis that detection probabilities and local extinction probabilities were negatively related. Our analyses support the hypothesis that species detection probability covaries negatively with local probability of extinction and turnover rates. A simulation study was conducted to assess the performance of vital parameter estimators as well as other estimators relevant to questions about heterogeneity, such as coefficient of variation of detection probabilities and proportion of species in each group. Both the weighted estimator suggested in this paper and the original unweighted estimator for local extinction probability performed fairly well and provided no basis for preferring one to the other.

Integration and scaling of UV-B radiation effects on plants: from molecular interactions to whole plant responses.

PubMed

Suchar, Vasile Alexandru; Robberecht, Ronald

2016-07-01

A process based model integrating the effects of UV-B radiation to molecular level processes and their consequences to whole plant growth and development was developed from key parameters in the published literature. Model simulations showed that UV-B radiation induced changes in plant metabolic and/or photosynthesis rates can result in plant growth inhibitions. The costs of effective epidermal UV-B radiation absorptive compounds did not result in any significant changes in plant growth, but any associated metabolic costs effectively reduced the potential plant biomass. The model showed significant interactions between UV-B radiation effects and temperature and any factor leading to inhibition of photosynthetic production or plant growth during the midday, but the effects were not cumulative for all factors. Vegetative growth were significantly delayed in species that do not exhibit reproductive cycles during a growing season, but vegetative growth and reproductive yield in species completing their life cycle in one growing season did not appear to be delayed more than 2-5 days, probably within the natural variability of the life cycles for many species. This is the first model to integrate the effects of increased UV-B radiation through molecular level processes and their consequences to whole plant growth and development.

Active life expectancy from annual follow-up data with missing responses.

PubMed

Izmirlian, G; Brock, D; Ferrucci, L; Phillips, C

2000-03-01

Active life expectancy (ALE) at a given age is defined as the expected remaining years free of disability. In this study, three categories of health status are defined according to the ability to perform activities of daily living independently. Several studies have used increment-decrement life tables to estimate ALE, without error analysis, from only a baseline and one follow-up interview. The present work conducts an individual-level covariate analysis using a three-state Markov chain model for multiple follow-up data. Using a logistic link, the model estimates single-year transition probabilities among states of health, accounting for missing interviews. This approach has the advantages of smoothing subsequent estimates and increased power by using all follow-ups. We compute ALE and total life expectancy from these estimated single-year transition probabilities. Variance estimates are computed using the delta method. Data from the Iowa Established Population for the Epidemiologic Study of the Elderly are used to test the effects of smoking on ALE on all 5-year age groups past 65 years, controlling for sex and education.

Food restriction promotes signaling effort in response to social challenge in a short-lived electric fish.

PubMed

Gavassa, Sat; Stoddard, Philip K

2012-09-01

Vertebrates exposed to stressful conditions release glucocorticoids to sustain energy expenditure. In most species elevated glucocorticoids inhibit reproduction. However individuals with limited remaining reproductive opportunities cannot afford to forgo reproduction and should resist glucocorticoid-mediated inhibition of reproductive behavior. The electric fish Brachyhypopomus gauderio has a single breeding season in its lifetime, thus we expect males to resist glucocorticoid-mediated inhibition of their sexual advertisement signals. We studied stress resistance in male B. gauderio (i) by examining the effect of exogenous cortisol administration on the signal waveform and (ii) by investigating the effect of food limitation on androgen and cortisol levels, the amplitude of the electric signal waveform, the responsiveness of the electric signal waveform to social challenge, and the amount of feeding activity. Exogenous cortisol administration did reduce signal amplitude and pulse duration, but endogenous cortisol levels did not rise with food limitation or social challenge. Despite food limitation, males responded to social challenges by further increasing androgen levels and enhancing the amplitude and duration of their electric signal waveforms. Food-restricted males increased androgen levels and signal pulse duration more than males fed ad libitum. Socially challenged fish increased food consumption, probably to compensate for their elevated energy expenditure. Previous studies showed that socially challenged males of this species simultaneously elevate testosterone and cortisol in proportion to signal amplitude. Thus, B. gauderio appears to protect its cortisol-sensitive electric advertisement signal by increasing food intake, limiting cortisol release, and offsetting signal reduction from cortisol with signal-enhancing androgens. Copyright © 2012 Elsevier Inc. All rights reserved.

Early response to therapy predicts 6-month and 1-year disease activity outcomes in psoriatic arthritis patients.

PubMed

Schoels, Monika M; Landesmann, Uriel; Alasti, Farideh; Baker, Daniel; Smolen, Josef S; Aletaha, Daniel

2018-06-01

In PsA management, remission and low disease activity represent preferential treatment targets. We aimed at evaluating the predictive value and clinical use of initial therapeutic response for subsequent achievement of these targets. Based on data of 216 patients enrolled in a randomized controlled trial of golimumab (GO-REVEAL), we performed diagnostic testing analyses using 3- and 6-month disease activity as tests for treatment outcomes to understand the implications of early response. In regression analyses, we estimated the probabilities for achieving at least LDA. Disease activity was measured by the disease activity index for PsA (DAPSA). Three-month DAPSA levels were excellent tests for disease activity at 6 months (and at 1 year), with areas under the receiver operating characteristic curves of 0.92 (and 0.88, respectively). The estimated probability for 6-month LDA could be quantified as <22% if patients did not reach at least moderate disease activity after 3 months on golimumab. Similar data were seen for early DAPSA response: patients achieving a DAPSA 85% at 3 months had an 84% probability for 6-month LDA or REM. All results were validated in an independent trial cohort of patients treated with infliximab (IMPACT 2). Three months after implementation of therapy in PsA, it is already possible to evaluate the potential for accomplishing therapeutic goals. This substantiates the choice of the 3-month assessment as essential for treatment adaptations.

Annoyance rate evaluation method on ride comfort of vehicle suspension system

NASA Astrophysics Data System (ADS)

Tang, Chuanyin; Zhang, Yimin; Zhao, Guangyao; Ma, Yan

2014-03-01

The existing researches of the evaluation method of ride comfort of vehicle mainly focus on the level of human feelings to vibration. The level of human feelings to vibration is influenced by many factors, however, the ride comfort according to the common principle of probability and statistics and simple binary logic is unable to reflect these uncertainties. The random fuzzy evaluation model from people subjective response to vibration is adopted in the paper, these uncertainties are analyzed from the angle of psychological physics. Discussing the traditional evaluation of ride comfort during vehicle vibration, a fuzzily random evaluation model on the basis of annoyance rate is proposed for the human body's subjective response to vibration, with relevant fuzzy membership function and probability distribution given. A half-car four degrees of freedom suspension vibration model is described, subject to irregular excitations from the road surface, with the aid of software Matlab/Simulink. A new kind of evaluation method for ride comfort of vehicles is proposed in the paper, i.e., the annoyance rate evaluation method. The genetic algorithm and neural network control theory are used to control the system. Simulation results are obtained, such as the comparison of comfort reaction to vibration environments between before and after control, relationship of annoyance rate to vibration frequency and weighted acceleration, based on ISO 2631/1(1982), ISO 2631-1(1997) and annoyance rate evaluation method, respectively. Simulated assessment results indicate that the proposed active suspension systems prove to be effective in the vibration isolation of the suspension system, and the subjective response of human being can be promoted from very uncomfortable to a little uncomfortable. Furthermore, the novel evaluation method based on annoyance rate can further estimate quantitatively the number of passengers who feel discomfort due to vibration. A new analysis method of vehicle comfort is presented.

Placebo effects in psychiatry: mediators and moderators

PubMed Central

Weimer, Katja; Colloca, Luana; Enck, Paul

2015-01-01

A strong placebo response in psychiatric disorders has been noted for the past 50 years and various attempts have been made to identify predictors of it, by use of meta-analyses of randomised controlled trials and laboratory studies. We reviewed 31 meta-analyses and systematic reviews of more than 500 randomised placebo-controlled trials across psychiatry (depression, schizophrenia, mania, attention-deficit hyperactivity disorder, autism, psychosis, binge-eating disorder, and addiction) for factors identified to be associated with increased placebo response. Of 20 factors discussed, only three were often linked to high placebo responses: low baseline severity of symptoms, more recent trials, and unbalanced randomisation (more patients randomly assigned to drug than placebo). Randomised controlled trials in non-drug therapy have not added further predictors, and laboratory studies with psychological, brain, and genetic approaches have not been successful in identifying predictors of placebo responses. This comprehensive Review suggests that predictors of the placebo response are still to be discovered, the response probably has more than one mediator, and that different and distinct moderators are probably what cause the placebo response within psychiatry and beyond. PMID:25815249

An uncertainty model of acoustic metamaterials with random parameters

NASA Astrophysics Data System (ADS)

He, Z. C.; Hu, J. Y.; Li, Eric

2018-01-01

Acoustic metamaterials (AMs) are man-made composite materials. However, the random uncertainties are unavoidable in the application of AMs due to manufacturing and material errors which lead to the variance of the physical responses of AMs. In this paper, an uncertainty model based on the change of variable perturbation stochastic finite element method (CVPS-FEM) is formulated to predict the probability density functions of physical responses of AMs with random parameters. Three types of physical responses including the band structure, mode shapes and frequency response function of AMs are studied in the uncertainty model, which is of great interest in the design of AMs. In this computation, the physical responses of stochastic AMs are expressed as linear functions of the pre-defined random parameters by using the first-order Taylor series expansion and perturbation technique. Then, based on the linear function relationships of parameters and responses, the probability density functions of the responses can be calculated by the change-of-variable technique. Three numerical examples are employed to demonstrate the effectiveness of the CVPS-FEM for stochastic AMs, and the results are validated by Monte Carlo method successfully.

Probability and volume of potential postwildfire debris flows in the 2010 Fourmile burn area, Boulder County, Colorado

USGS Publications Warehouse

Ruddy, Barbara C.; Stevens, Michael R.; Verdin, Kristine

2010-01-01

This report presents a preliminary emergency assessment of the debris-flow hazards from drainage basins burned by the Fourmile Creek fire in Boulder County, Colorado, in 2010. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of debris-flow occurrence and volumes of debris flows for selected drainage basins. Data for the models include burn severity, rainfall total and intensity for a 25-year-recurrence, 1-hour-duration rainstorm, and topographic and soil property characteristics. Several of the selected drainage basins in Fourmile Creek and Gold Run were identified as having probabilities of debris-flow occurrence greater than 60 percent, and many more with probabilities greater than 45 percent, in response to the 25-year recurrence, 1-hour rainfall. None of the Fourmile Canyon Creek drainage basins selected had probabilities greater than 45 percent. Throughout the Gold Run area and the Fourmile Creek area upstream from Gold Run, the higher probabilities tend to be in the basins with southerly aspects (southeast, south, and southwest slopes). Many basins along the perimeter of the fire area were identified as having low probability of occurrence of debris flow. Volume of debris flows predicted from drainage basins with probabilities of occurrence greater than 60 percent ranged from 1,200 to 9,400 m3. The predicted moderately high probabilities and some of the larger volumes responses predicted for the modeled storm indicate a potential for substantial debris-flow effects to buildings, roads, bridges, culverts, and reservoirs located both within these drainages and immediately downstream from the burned area. However, even small debris flows that affect structures at the basin outlets could cause considerable damage.

Comparative effect of direct-fed microbials on fecal shedding of Escherichia coli O157:H7 and Salmonella in naturally infected feedlot cattle.

PubMed

Tabe, Ebot S; Oloya, James; Doetkott, Dawn K; Bauer, Marc L; Gibbs, Penelope S; Khaitsa, Margaret L

2008-03-01

The effect of direct-fed microbials (DFM) on fecal shedding of Escherichia coli O157:H7 and Salmonella in naturally infected feedlot cattle was evaluated in a clinical trial involving 138 feedlot steers. Following standard laboratory methods, fecal samples collected from steers were evaluated for change in the detectable levels of E. coli O157:H7 and Salmonella shed in feces after DFM treatment. Sampling of steers was carried out every 3 weeks for 84 days. A significant reduction (32%) in fecal shedding of E. coli O157:H7 (P < 0.001), but not Salmonella (P = 0.24), was observed among the treatment steers compared with the control group during finishing. The probability of recovery of E. coli O157:H7 from the feces of treated and control steers was 34.0 and 66.0%, respectively. Steers placed on DFM supplement were almost three times less likely to shed E. coli O157:H7 (odds ratio, 0.36; 95% confidence interval, 0.25 to 0.53; P < 0.001) in their feces as opposed to their control counterparts. The probability of recovery of Salmonella from the feces of the control (14.0%) and the treated (11.3%) steers was similar. However, the DFM significantly reduced probability of new infections with Salmonella among DFM-treated cattle compared with controls (nontreated ones). It appears that DFM as applied in our study are capable of significantly reducing fecal shedding of E. coli O157:H7 in naturally infected cattle but not Salmonella. The factors responsible for the observed difference in the effects of DFM on E. coli O157:H7 and Salmonella warrants further investigation.

Helicopter roll control effectiveness criteria program summary

NASA Technical Reports Server (NTRS)

Heffley, Robert K.; Bourne, Simon M.; Mnich, Marc A.

1988-01-01

A study of helicopter roll control effectiveness is summarized for the purpose of defining military helicopter handling qualities requirements. The study is based on an analysis of pilot-in-the-loop task performance of several basic maneuvers. This is extended by a series of piloted simulations using the NASA Ames Vertical Motion Simulator and selected flight data. The main results cover roll control power and short-term response characteristics. In general the handling qualities requirements recommended are set in conjunction with desired levels of flight task and maneuver response which can be directly observed in actual flight. An important aspect of this, however, is that vehicle handling qualities need to be set with regard to some quantitative aspect of mission performance. Specific examples of how this can be accomplished include a lateral unmask/remask maneuver in the presence of a threat and an air tracking maneuver which recognizes the kill probability enhancement connected with decreasing the range to the target. Conclusions and recommendations address not only the handling qualities recommendations, but also the general use of flight simulators and the dependence of mission performance on handling qualities.

Effect of oral zinc supplementation upon Taenia crassiceps murine cysticercosis.

PubMed

Fragoso, G; Lastra, M D; Aguilar, A E; Pastelin, R; Rosas, G; Meneses, G; Sciutto, E; Lamoyi, E

2001-10-01

The effect of zinc supplementation on Taenia crassiceps murine cysticercosis was studied in susceptible BALB/cAnN mice. Female offspring of mice supplemented with high zinc throughout gestation and lactation were intraperitoneally infected with T. crassiceps cysticerci. Offspring from nonsupplemented mothers were used as controls. Significantly fewer parasites were recovered from zinc-supplemented mice (Zsm) 30 days after infection. Increased resistance was not related to the IgG antibody response. At early stages of infection, T cells from Zsm proliferated to T. crassiceps antigens, whereas cells from control mice did not respond. Infection caused in both groups a decrease in CD3+ cell percentages, which was more pronounced in the controls, and paralleled by a decrease in CD8+ cells; CD3+ and CD8+ percentages returned to normal levels at later stages of infection. In contrast, the CD4+ subpopulation only decreased in control mice. Intracellular cytokine determinations indicate that zinc supplementation favored a stronger and persistent type-1 T cell response in cysticerci-infected mice, which probably participates in the observed increased resistance.

Medical ozone increases methotrexate clinical response and improves cellular redox balance in patients with rheumatoid arthritis.

PubMed

León Fernández, Olga Sonia; Viebahn-Haensler, Renate; Cabreja, Gilberto López; Espinosa, Irainis Serrano; Matos, Yanet Hernández; Roche, Liván Delgado; Santos, Beatriz Tamargo; Oru, Gabriel Takon; Polo Vega, Juan Carlos

2016-10-15

Medical ozone reduced inflammation, IL-1β, TNF-α mRNA levels and oxidative stress in PG/PS-induced arthritis in rats. The aim of this study was to investigate the medical ozone effects in patients with rheumatoid arthritis treated with methotrexate and methotrexate+ozone, and to compare between them. A randomized clinical study with 60 patients was performed, who were divided into two groups: one (n=30) treated with methotrexate (MTX), folic acid and Ibuprophen (MTX group) and the second group (n=30) received the same as the MTX group+medical ozone by rectal insufflation of the gas (MTX+ozone group). The clinical response of the patients was evaluated by comparing Disease Activity Score 28 (DAS28), Health Assessment Questionnaire Disability Index (HAQ-DI), Anti-Cyclic Citrullinated (Anti-CCP) levels, reactants of acute phase and biochemical markers of oxidative stress before and after 20 days of treatment. MTX+ozone reduced the activity of the disease while MTX merely showed a tendency to decrease the variables. Reactants of acute phase displayed a similar picture. MTX+ozone reduced Anti-CCP levels as well as increased antioxidant system, and decreased oxidative damage whereas MTX did not change. Glutathione correlated with all clinical variables just after MTX+ozone. MTX+ozone increased the MTX clinical response in patients with rheumatoid arthritis. No side effects were observed. These results suggest that ozone can increase the efficacy of MTX probably because both share common therapeutic targets. Medical ozone treatment is capable of being a complementary therapy in the treatment of rheumatoid arthritis. Copyright © 2016 Elsevier B.V. All rights reserved.

Responses and recovery assessment of continuously cultured Nitrosomonas europaea under chronic ZnO nanoparticle stress: Effects of dissolved oxygen.

PubMed

Wu, Junkang; Chang, Yan; Gao, Huan; Liang, Geyu; Yu, Ran; Ding, Zhen

2018-03-01

Although the antibacterial performances of emerging nanoparticles (NPs) have been extensively explored in the nitrifying systems, the impacts of dissolved oxygen (DO) levels on their bio-toxicities to the nitrifiers and the impaired cells' recovery potentials have seldom been addressed yet. In this study, the physiological and transcriptional responses of the typical ammonia oxidizers - Nitrosomonas europaea in a chemostat to the chronic ZnO NP exposure under different DO conditions were investigated. The results indicated that the cells in steady-growth state in the chemostat were more persevering than batch cultured ones to resist ZnO NP stress despite the dose-dependent NP inhibitory effects were observed. In addition, the occurred striking over-expressions of amoA and hao genes at the initial NP exposure stage suggested the cells' self-regulation potentials at the transcriptional level. The low DO (0.5 mg/L) cultured cells displayed higher sensitivity to NP stress than the high DO (2.0 mg/L) cultured ones, probably owning to the inefficient oxygen-dependent electron transfer from ammonia oxidation for energy conversion/production. The following 12-h NP-free batch recovery assays revealed that both high and low DO cultured cells possessed the physiological and metabolic activity recovery potentials, which were in negative correlation with the NP exposure time. The duration of NP stress and the resulting NP dissolution were critical for the cells' damage levels and their performance recoverability. The membrane preservation processes and the associated metabolism regulations were expected to actively participate in the cells' self-adaption to NP stress and thus be responsible for their metabolic activities recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-additive effects of pollen limitation and self-incompatibility reduce plant reproductive success and population viability

PubMed Central

Young, Andrew G.; Broadhurst, Linda M.; Thrall, Peter H.

2012-01-01

Background and Aims Mating system is a primary determinant of the ecological and evolutionary dynamics of wild plant populations. Pollen limitation and loss of self-incompatibility genotypes can both act independently to reduce seed set and these effects are commonly observed in fragmented landscapes. This study used a simulation modelling approach to assess the interacting effects of these two processes on plant reproductive performance and population viability for a range of pollination likelihood, self-incompatibility systems and S-allele richness conditions. Methods A spatially explicit, individual-based, genetic and demographic simulation model parameterized to represent a generic self-incompatible, short-lived perennial herb was used to conduct simulation experiments in which pollination probability, self-incompatibility type (gametophytic and sporophytic) and S-allele richness were systematically varied in combination to assess their independent and interacting effects on the demographic response variables of mate availability, seed set, population size and population persistence. Key Results Joint effects of reduced pollination probability and low S-allele richness were greater than independent effects for all demographic response variables except population persistence under high pollinator service (>50 %). At intermediate values of 15–25 % pollination probability, non-linear interactions with S-allele richness generated significant reductions in population performance beyond those expected by the simple additive effect of each independently. This was due to the impacts of reduced effective population size on the ability of populations to retain S alleles and maintain mate availability. Across a limited set of pollination and S-allele conditions (P = 0·15 and S = 20) populations with gametophytic SI showed reduced S-allele erosion relative to those with sporophytic SI, but this had limited effects on individual fecundity and translated into only modest increases in population persistence. Conclusions Interactions between pollen limitation and loss of S alleles have the potential to significantly reduce the viability of populations of a few hundred plants. Population decline may occur more rapidly than expected when pollination probabilities drop below 25 % and S alleles are fewer than 20 due to non-additive interactions. These are likely to be common conditions experienced by plants in small populations in fragmented landscapes and are also those under which differences in response between gameptophytic and sporophtyic systems are observed. PMID:22184620

Non-additive effects of pollen limitation and self-incompatibility reduce plant reproductive success and population viability.

PubMed

Young, Andrew G; Broadhurst, Linda M; Thrall, Peter H

2012-02-01

Mating system is a primary determinant of the ecological and evolutionary dynamics of wild plant populations. Pollen limitation and loss of self-incompatibility genotypes can both act independently to reduce seed set and these effects are commonly observed in fragmented landscapes. This study used a simulation modelling approach to assess the interacting effects of these two processes on plant reproductive performance and population viability for a range of pollination likelihood, self-incompatibility systems and S-allele richness conditions. A spatially explicit, individual-based, genetic and demographic simulation model parameterized to represent a generic self-incompatible, short-lived perennial herb was used to conduct simulation experiments in which pollination probability, self-incompatibility type (gametophytic and sporophytic) and S-allele richness were systematically varied in combination to assess their independent and interacting effects on the demographic response variables of mate availability, seed set, population size and population persistence. Joint effects of reduced pollination probability and low S-allele richness were greater than independent effects for all demographic response variables except population persistence under high pollinator service (>50 %). At intermediate values of 15-25 % pollination probability, non-linear interactions with S-allele richness generated significant reductions in population performance beyond those expected by the simple additive effect of each independently. This was due to the impacts of reduced effective population size on the ability of populations to retain S alleles and maintain mate availability. Across a limited set of pollination and S-allele conditions (P = 0·15 and S = 20) populations with gametophytic SI showed reduced S-allele erosion relative to those with sporophytic SI, but this had limited effects on individual fecundity and translated into only modest increases in population persistence. Interactions between pollen limitation and loss of S alleles have the potential to significantly reduce the viability of populations of a few hundred plants. Population decline may occur more rapidly than expected when pollination probabilities drop below 25 % and S alleles are fewer than 20 due to non-additive interactions. These are likely to be common conditions experienced by plants in small populations in fragmented landscapes and are also those under which differences in response between gameptophytic and sporophtyic systems are observed.

Ethical issues across different fields of forensic science.

PubMed

Yadav, Praveen Kumar

2017-01-01

Many commentators have acknowledged the fact that the usual courtroom maxim to "tell the truth, the whole truth, and nothing but the truth" is not so easy to apply in practicality. In any given situation, what does the whole truth include? In case, the whole truth includes all the possible alternatives for a given situation, what should a forensic expert witness do when an important question is not asked by the prosecutor? Does the obligation to tell the whole truth mean that all possible, all probable, all reasonably probable, all highly probable, or only the most probable alternatives must be given in response to a question? In this paper, an attempt has been made to review the various ethical issues in different fields of forensic science, forensic psychology, and forensic DNA databases. Some of the ethical issues are common to all fields whereas some are field specific. These ethical issues are mandatory for ensuring high levels of reliability and credibility of forensic scientists.

COUNTRY-LEVEL SOCIOECONOMIC INDICATORS ASSOCIATED WITH SURVIVAL PROBABILITY OF BECOMING A CENTENARIAN AMONG OLDER EUROPEAN ADULTS: GENDER INEQUALITY, MALE LABOUR FORCE PARTICIPATION AND PROPORTIONS OF WOMEN IN PARLIAMENTS.

PubMed

Kim, Jong In; Kim, Gukbin

2017-03-01

This study confirms an association between survival probability of becoming a centenarian (SPBC) for those aged 65 to 69 and country-level socioeconomic indicators in Europe: the gender inequality index (GII), male labour force participation (MLP) rates and proportions of seats held by women in national parliaments (PWP). The analysis was based on SPBC data from 34 countries obtained from the United Nations (UN). Country-level socioeconomic indicator data were obtained from the UN and World Bank databases. The associations between socioeconomic indicators and SPBC were assessed using correlation coefficients and multivariate regression models. The findings show significant correlations between the SPBC for women and men aged 65 to 69 and country-level socioeconomic indicators: GII (r=-0.674, p=0.001), MLP (r=0.514, p=0.002) and PWP (r=0.498, p=0.003). The SPBC predictors for women and men were lower GIIs and higher MLP and PWP (R 2=0.508, p=0.001). Country-level socioeconomic indicators appear to have an important effect on the probability of becoming a centenarian in European adults aged 65 to 69. Country-level gender equality policies in European counties may decrease the risk of unhealthy old age and increase longevity in elders through greater national gender equality; disparities in GII and other country-level socioeconomic indicators impact longevity probability. National longevity strategies should target country-level gender inequality.

Predator response to releases of American shad larvae in the Susquehanna River basin

USGS Publications Warehouse

Johnson, James H.; Ringler, N.H.

1998-01-01

Predation on American shad (Alosa sapidissima) larvae within the first two hours of release was examined from 1989 to 1992 on 31 occasions at stocking sites in the Susquehanna River basin. Twenty-two fish species consumed shad larvae; the dominant predators were spotfin shiner (Cyprinella spiloptera), mimic shiner (Notropis volucellus) and juvenile smallmouth bass (Micropterus dolomieu). The number of shad larvae found in predator stomachs ranged from 0 to 900. Mortality of shad larvae at the stocking site was usually less than 2%. The greatest mortality (9.6%) occurred at the highest stocking level (1.5 million larvae). Highly variable predation rates and release levels of shad insufficient to achieve predator satiation hindered the ability to determine a specific type of functional response of predators. Predator numbers increased with stocking density, indicating short-term aggregation at the release site. Because of practical problems associated with releasing the large numbers of larvae that would be required to satiate predators, routine stocking at these levels is probably unreasonable. Releases of 400,000 to 700,000 larvae may reduce predation by offsetting depensatory mechanisms that operate on small releases and the effects of increased predation due to predator aggregation on large releases. Night stocking may reduce predation on larval shad at the release site.

Nuclear-effects model embedded stochastically in simulation (NEMESIS) summary report. Technical paper

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

Youngren, M.A.

1989-11-01

An analytic probability model of tactical nuclear warfare in the theater is presented in this paper. The model addresses major problems associated with representing nuclear warfare in the theater. Current theater representations of a potential nuclear battlefield are developed in context of low-resolution, theater-level models or scenarios. These models or scenarios provide insufficient resolution in time and space for modeling a nuclear exchange. The model presented in this paper handles the spatial uncertainty in potentially targeted unit locations by proposing two-dimensional multivariate probability models for the actual and perceived locations of units subordinate to the major (division-level) units represented inmore » theater scenarios. The temporal uncertainty in the activities of interest represented in our theater-level Force Evaluation Model (FORCEM) is handled through probability models of the acquisition and movement of potential nuclear target units.« less

Early physiological response to intensive care as a clinically relevant approach to predicting the outcome in severe acute pancreatitis.

PubMed

Flint, Richard; Windsor, John A

2004-04-01

The physiological response to treatment is a better predictor of outcome in acute pancreatitis than are traditional static measures. Retrospective diagnostic test study. The criterion standard was Organ Failure Score (OFS) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score at the time of hospital admission. Intensive care unit of a tertiary referral center, Auckland City Hospital, Auckland, New Zealand. Consecutive sample of 92 patients (60 male, 32 female; median age, 61 years; range, 24-79 years) with severe acute pancreatitis. Twenty patients were not included because of incomplete data. The cause of pancreatitis was gallstones (42%), alcohol use (27%), or other (31%). At hospital admission, the mean +/- SD OFS was 8.1 +/- 6.1, and the mean +/- SD APACHE II score was 19.9 +/- 8.2. All cases were managed according to a standardized protocol. There was no randomization or testing of any individual interventions. Survival and death. There were 32 deaths (pretest probability of dying was 35%). The physiological response to treatment was more accurate in predicting the outcome than was OFS or APACHE II score at hospital admission. For example, 17 patients had an initial OFS of 7-8 (posttest probability of dying was 58%); after 48 hours, 7 had responded to treatment (posttest probability of dying was 28%), and 10 did not respond (posttest probability of dying was 82%). The effect of the change in OFS and APACHE II score was graphically depicted by using a series of logistic regression equations. The resultant sigmoid curve suggests that there is a midrange of scores (the steep portion of the graph) within which the probability of death is most affected by the response to intensive care treatment. Measuring the initial severity of pancreatitis combined with the physiological response to intensive care treatment is a practical and clinically relevant approach to predicting death in patients with severe acute pancreatitis.

The effect of juvenile hormone on Polistes wasp fertility varies with cooperative behavior.

PubMed

Tibbetts, Elizabeth A; Sheehan, Michael J

2012-04-01

Social insects provide good models for studying how and why the mechanisms that underlie reproduction vary, as there is dramatic reproductive plasticity within and between species. Here, we test how the effect of juvenile hormone (JH) on fertility covaries with cooperative behavior in workers and nest-founding queens in the primitively eusocial wasp Polistes metricus. P. metricus foundresses and workers appear morphologically similar and both are capable of reproduction, though there is variation in the extent of social cooperation and the probability of reproduction across castes. Do the endocrine mechanisms that mediate reproduction co-vary with cooperative behavior? We found dramatic differences in the effect of JH on fertility across castes. In non-cooperative nest-founding queens, all individuals responded to JH by increasing their fertility. However, in cooperative workers, the effect of JH on fertility varies with body weight; large workers increase their fertility in response to JH while small workers do not. The variation in JH response may be an adaptation to facilitate resource allocation based on the probability of independent reproduction. This work contrasts with previous studies in closely related Polistes dominulus paper wasps, in which both foundresses and workers form cooperative associations and both castes show similar, condition-dependent JH response. The variation in JH responsiveness within and between species suggests that endocrine responsiveness and the factors influencing caste differentiation are surprisingly evolutionarily labile. Copyright © 2012 Elsevier Inc. All rights reserved.

Nuclear risk analysis of the Ulysses mission

NASA Astrophysics Data System (ADS)

Bartram, Bart W.; Vaughan, Frank R.; Englehart, Richard W., Dr.

1991-01-01

The use of a radioisotope thermoelectric generator fueled with plutonium-238 dioxide on the Space Shuttle-launched Ulysses mission implies some level of risk due to potential accidents. This paper describes the method used to quantify risks in the Ulysses mission Final Safety Analysis Report prepared for the U.S. Department of Energy. The starting point for the analysis described herein is following input of source term probability distributions from the General Electric Company. A Monte Carlo technique is used to develop probability distributions of radiological consequences for a range of accident scenarios thoughout the mission. Factors affecting radiological consequences are identified, the probability distribution of the effect of each factor determined, and the functional relationship among all the factors established. The probability distributions of all the factor effects are then combined using a Monte Carlo technique. The results of the analysis are presented in terms of complementary cumulative distribution functions (CCDF) by mission sub-phase, phase, and the overall mission. The CCDFs show the total probability that consequences (calculated health effects) would be equal to or greater than a given value.

Effects of Spatial and Selective Attention on Basic Multisensory Integration

ERIC Educational Resources Information Center

Gondan, Matthias; Blurton, Steven P.; Hughes, Flavia; Greenlee, Mark W.

2011-01-01

When participants respond to auditory and visual stimuli, responses to audiovisual stimuli are substantially faster than to unimodal stimuli (redundant signals effect, RSE). In such tasks, the RSE is usually higher than probability summation predicts, suggestive of specific integration mechanisms underlying the RSE. We investigated the role of…

Superpulsed (Ga-As, 904 nm) low-level laser therapy (LLLT) attenuates inflammatory response and enhances healing of burn wounds.

PubMed

Gupta, Asheesh; Keshri, Gaurav K; Yadav, Anju; Gola, Shefali; Chauhan, Satish; Salhan, Ashok K; Bala Singh, Shashi

2015-06-01

Low-level laser therapy (LLLT) using superpulsed near-infrared light can penetrate deeper in the injured tissue and could allow non-pharmacological treatment for chronic wound healing. This study investigated the effects of superpulsed laser (Ga-As 904 nm, 200 ns pulse width; 100 Hz; 0.7 mW mean output power; 0.4 mW/cm(2) average irradiance; 0.2 J/cm(2) total fluence) on the healing of burn wounds in rats, and further explored the probable associated mechanisms of action. Irradiated group exhibited enhanced DNA, total protein, hydroxyproline and hexosamine contents compared to the control and silver sulfadiazine (reference care) treated groups. LLLT exhibited decreased TNF-α level and NF-kB, and up-regulated protein levels of VEGF, FGFR-1, HSP-60, HSP-90, HIF-1α and matrix metalloproteinases-2 and 9 compared to the controls. In conclusion, LLLT using superpulsed 904 nm laser reduced the inflammatory response and was able to enhance cellular proliferation, collagen deposition and wound contraction in the repair process of burn wounds. Photomicrographs showing no, absence inflammation and faster wound contraction in LLLT superpulsed (904 nm) laser treated burn wounds as compared to the non-irradiated control and silver sulfadiazine (SSD) ointment (reference care) treated wounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of direct-to-consumer genetic tests on anticipated affect and health-seeking behaviors: a pilot survey.

PubMed

Bansback, Nick; Sizto, Sonia; Guh, Daphne; Anis, Aslam H

2012-10-01

Numerous websites offer direct-to-consumer (DTC) genetic testing, yet it is unknown how individuals will react to genetic risk profiles online. The objective of this study was to determine the feasibility of using a web-based survey and conjoint methods to elicit individuals' interpretations of genetic risk profiles by their anticipated worry/anxiousness and health-seeking behaviors. A web-based survey was developed using conjoint methods. Each survey presented 12 hypothetical genetic risk profiles describing genetic test results for four diseases. Test results were characterized by the type of disease (eight diseases), individual risk (five levels), and research confidence (three levels). After each profile, four questions were asked regarding anticipated worry and health-seeking behaviors. Probabilities of response outcomes based on attribute levels were estimated from logistic regression models, adjusting for covariates. Overall, 319 participants (69%) completed 3828 unique genetic risk profiles. Across all profiles, most participants anticipated making doctor's appointments (63%), lifestyle changes (57%), and accessing screening (57%); 40% anticipated feeling more worried and anxious. Higher levels of disease risk were significantly associated with affirmative responses. Conjoint methods may be used to elicit reactions to genetic information online. Preliminary results suggest that genetic information may increase worry/anxiousness and health-seeking behaviors among consumers of DTC tests. Further research is planned to determine the appropriateness of these affects and behaviors.

Influence of anaesthetics on tumour-cell kill and repopulation in B16 melanoma treated with melphalan.

PubMed Central

Peacock, J. H.; Stephens, T. C.

1978-01-01

The influence of anaesthetics on the in vivo response of B16 melanoma to melphalan was studied using an in vitro cell-survival assay. Three anaesthetics were used, Saffan (Althesin) Sagatal (Nembutal) and Hypnorm. When Saffan was administered to tumour-bearing animals before melphalan there was a significant increase in tumour-cell kill. This effect was not observed with Sagatal or Hypnorm. Maximum increase in tumour-cell kill was achieved when Saffan was administered about 1 h before melphalan, and was dependent on Saffan dose. Clonogenic tumour-cell repopulation after melphalan was rapid (TD - 1 day) and the rate was similar from 2 levels of cell kill. When Saffan was combined with melphalan the repopulation rate was the same as with melphalan alone, and the increased cell kill was reflected in increased growth delay. The in vitro response of B16 melanoma cells to melphalan was unaltered by pretreatment with, or simultaneous exposure to Saffan. The results suggest that the mechanism of the enhanced cell kill in vivo is probably due to an indirect systemic effect, rather than a direct effect on the tumour cells. PMID:743490

Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees.

PubMed

Youngsteadt, Elsa; Appler, R Holden; López-Uribe, Margarita M; Tarpy, David R; Frank, Steven D

2015-01-01

Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus), the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators.

Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees

PubMed Central

López-Uribe, Margarita M.; Tarpy, David R.; Frank, Steven D.

2015-01-01

Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus), the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators. PMID:26536606

Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone

PubMed Central

Lokuge, Kamalini; Caleo, Grazia; Greig, Jane; Duncombe, Jennifer; McWilliam, Nicholas; Squire, James; Lamin, Manjo; Veltus, Emily; Wolz, Anja; Kobinger, Gary; de la Vega, Marc-Antoine; Gbabai, Osman; Nabieu, Sao; Lamin, Mohammed; Kremer, Ronald; Danis, Kostas; Banks, Emily; Glass, Kathryn

2016-01-01

Introduction The scale and geographical distribution of the current outbreak in West Africa raised doubts as to the effectiveness of established methods of control. Ebola Virus Disease (EVD) was first detected in Sierra Leone in May 2014 in Kailahun district. Despite high case numbers elsewhere in the country, transmission was eliminated in the district by December 2014. We describe interventions underpinning successful EVD control in Kailahun and implications for EVD control in other areas. Methods Internal service data and published reports from response agencies were analysed to describe the structure and type of response activities, EVD case numbers and epidemic characteristics. This included daily national situation reports and District-level data and reports of the Sierra Leone Ministry of Health and Sanitation, and Médecins Sans Frontières (MSF) patient data and internal epidemiological reports. We used EVD case definitions provided by the World Health Organisation over the course of the outbreak. Characteristics assessed included level of response activities and epidemiological features such as reported exposure (funeral-related or not), time interval between onset of illness and admission to the EVD Management Centre (EMC), work-related exposures (health worker or not) and mortality. We compared these characteristics between two time periods—June to July (the early period of response), and August to December (when coverage and quality of response had improved). A stochastic model was used to predict case numbers per generation with different numbers of beds and a varying percentage of community cases detected. Results There were 652 probable/confirmed EVD cases from June-December 2014 in Kailahun. An EMC providing patient care opened in June. By August 2014 an integrated detection, treatment, and prevention strategy was in place across the district catchment zone. From June-July to August-December 2014 surveillance and contact tracing staff increased from 1.0 to 8.8 per confirmed EVD case, EMC capacity increased from 32 to 100 beds, the number of burial teams doubled, and health promotion activities increased in coverage. These improvements in response were associated with the following changes between the same periods: the proportion of confirmed/probable cases admitted to the EMC increased from 35% to 83% (χ2 p-value<0·001), the proportion of confirmed patients admitted to the EMC <3 days of symptom onset increased from 19% to 37% (χ2 p-value <0·001), and reported funeral contact in those admitted decreased from 33% to 16% (χ2 p-value <0·001). Mathematical modelling confirmed the importance of both patient management capacity and surveillance and contact tracing for EVD control. Discussion Our findings demonstrate that control of EVD can be achieved using established interventions based on identification and appropriate management of those who are at risk of and develop EVD, including in the context of ongoing transmission in surrounding regions. Key attributes in achieving control were sufficient patient care capacity (including admission to specialist facilities of suspect and probable cases for assessment), integrated with adequate staffing and resourcing of community-based case detection and prevention activities. The response structure and coverage targets we present are of value in informing effective control in current and future EVD outbreaks. PMID:26959413

Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone.

PubMed

Lokuge, Kamalini; Caleo, Grazia; Greig, Jane; Duncombe, Jennifer; McWilliam, Nicholas; Squire, James; Lamin, Manjo; Veltus, Emily; Wolz, Anja; Kobinger, Gary; de la Vega, Marc-Antoine; Gbabai, Osman; Nabieu, Sao; Lamin, Mohammed; Kremer, Ronald; Danis, Kostas; Banks, Emily; Glass, Kathryn

2016-03-01

The scale and geographical distribution of the current outbreak in West Africa raised doubts as to the effectiveness of established methods of control. Ebola Virus Disease (EVD) was first detected in Sierra Leone in May 2014 in Kailahun district. Despite high case numbers elsewhere in the country, transmission was eliminated in the district by December 2014. We describe interventions underpinning successful EVD control in Kailahun and implications for EVD control in other areas. Internal service data and published reports from response agencies were analysed to describe the structure and type of response activities, EVD case numbers and epidemic characteristics. This included daily national situation reports and District-level data and reports of the Sierra Leone Ministry of Health and Sanitation, and Médecins Sans Frontières (MSF) patient data and internal epidemiological reports. We used EVD case definitions provided by the World Health Organisation over the course of the outbreak. Characteristics assessed included level of response activities and epidemiological features such as reported exposure (funeral-related or not), time interval between onset of illness and admission to the EVD Management Centre (EMC), work-related exposures (health worker or not) and mortality. We compared these characteristics between two time periods--June to July (the early period of response), and August to December (when coverage and quality of response had improved). A stochastic model was used to predict case numbers per generation with different numbers of beds and a varying percentage of community cases detected. There were 652 probable/confirmed EVD cases from June-December 2014 in Kailahun. An EMC providing patient care opened in June. By August 2014 an integrated detection, treatment, and prevention strategy was in place across the district catchment zone. From June-July to August-December 2014 surveillance and contact tracing staff increased from 1.0 to 8.8 per confirmed EVD case, EMC capacity increased from 32 to 100 beds, the number of burial teams doubled, and health promotion activities increased in coverage. These improvements in response were associated with the following changes between the same periods: the proportion of confirmed/probable cases admitted to the EMC increased from 35% to 83% (χ(2) p-value<0·001), the proportion of confirmed patients admitted to the EMC <3 days of symptom onset increased from 19% to 37% (χ(2) p-value <0·001), and reported funeral contact in those admitted decreased from 33% to 16% (χ(2) p-value <0·001). Mathematical modelling confirmed the importance of both patient management capacity and surveillance and contact tracing for EVD control. Our findings demonstrate that control of EVD can be achieved using established interventions based on identification and appropriate management of those who are at risk of and develop EVD, including in the context of ongoing transmission in surrounding regions. Key attributes in achieving control were sufficient patient care capacity (including admission to specialist facilities of suspect and probable cases for assessment), integrated with adequate staffing and resourcing of community-based case detection and prevention activities. The response structure and coverage targets we present are of value in informing effective control in current and future EVD outbreaks.

Toward an ecological analysis of Bayesian inferences: how task characteristics influence responses

PubMed Central

Hafenbrädl, Sebastian; Hoffrage, Ulrich

2015-01-01

In research on Bayesian inferences, the specific tasks, with their narratives and characteristics, are typically seen as exchangeable vehicles that merely transport the structure of the problem to research participants. In the present paper, we explore whether, and possibly how, task characteristics that are usually ignored influence participants’ responses in these tasks. We focus on both quantitative dimensions of the tasks, such as their base rates, hit rates, and false-alarm rates, as well as qualitative characteristics, such as whether the task involves a norm violation or not, whether the stakes are high or low, and whether the focus is on the individual case or on the numbers. Using a data set of 19 different tasks presented to 500 different participants who provided a total of 1,773 responses, we analyze these responses in two ways: first, on the level of the numerical estimates themselves, and second, on the level of various response strategies, Bayesian and non-Bayesian, that might have produced the estimates. We identified various contingencies, and most of the task characteristics had an influence on participants’ responses. Typically, this influence has been stronger when the numerical information in the tasks was presented in terms of probabilities or percentages, compared to natural frequencies – and this effect cannot be fully explained by a higher proportion of Bayesian responses when natural frequencies were used. One characteristic that did not seem to influence participants’ response strategy was the numerical value of the Bayesian solution itself. Our exploratory study is a first step toward an ecological analysis of Bayesian inferences, and highlights new avenues for future research. PMID:26300791

Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments

PubMed Central

Sperber, Carlos Frankl; Albeny-Simões, Daniel; Breaux, Jennifer Ann; Fianco, Marcos; Szinwelski, Neucir

2017-01-01

For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying. PMID:28977023

Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments.

PubMed

de Farias-Martins, Fernando; Sperber, Carlos Frankl; Albeny-Simões, Daniel; Breaux, Jennifer Ann; Fianco, Marcos; Szinwelski, Neucir

2017-01-01

For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.

Ecological risk assessment of a coastal zone in Southern Vietnam: Spatial distribution and content of heavy metals in water and surface sediments of the Thi Vai Estuary and Can Gio Mangrove Forest.

PubMed

Costa-Böddeker, Sandra; Hoelzmann, Philipp; Thuyên, Lê Xuân; Huy, Hoang Duc; Nguyen, Hoang Anh; Richter, Otto; Schwalb, Antje

2017-01-30

Enrichment of heavy metals was assessed in the Thi Vai Estuary and in the Can Gio Mangrove Forest (SE, Vietnam). Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn contents in water and in sediments were measured. Total organic carbon, nitrogen, phosphorus and C/N ratios were determined. Cu and Cr values were higher than threshold effect level of toxicity, while Ni exceeded probable effect level, indicating the risk of probable toxicity effects. Enrichment factors (EF), contamination factor (CF) and Geo-accumulation index (I-geo) were determined. CF reveals moderate to considerable pollution with Cr and Ni. EF suggests anthropogenic sources of Cr, Cu and Ni. I-geo indicates low contamination with Co, Cu and Zn and moderate contamination with Cr and Ni. Overall metal contents were lower than expected for this highly industrialized region, probably due to dilution, suggesting that erosion rates and hydrodynamics may also play a role in metal contents distribution. Copyright © 2016 Elsevier Ltd. All rights reserved.

A randomized controlled trial comparing three invitation strategies in a breast cancer screening program.

PubMed

Segura, J M; Castells, X; Casamitjana, M; Macià, F; Porta, M; Katz, S J

2001-10-01

The objective of this study was to compare the response received by a population-based breast cancer screening program, according to three different invitation strategies: letters sent by mail from the program (program group), letters sent by mail from the Primary Health Care Team (PHT group), and direct contact through a trained professional (direct contact group). We used a cluster-randomized controlled trial with assignment to invitation group using home address. Nine hundred eighty-six women of Barcelona (Spain), ages 50 to 64 years, were invited to participate in the program. The main outcome used was the response rate after the first invitation. Five hundred sixty-four women accepted the invitation (57.2%). The highest response rate was achieved in the direct contact group (63.5%), followed by the PHT group (55.6%), the program group being the one that attained the lowest response rate (52.1%). The direct contact group had a higher probability of participating than the PHT group (RR = 1.14, P = 0.037) or the program group (RR = 1.22, P = 0.003). The response rate in the direct contact group was 72.1% when the letter was received by the subject herself. The increase in response occurred particularly among women of lower educational level. Inviting women to participate in a breast cancer screening program through direct contact by trained personnel increased participation rate compared with mailed-letter methods. The positive effect appeared restricted to women with lower educational levels. Copyright 2001 American Health Foundation and Academic Press.

Mention effect in information diffusion on a micro-blogging network

PubMed Central

Shen, Hua-Wei; Huang, Junming; Chen, Haiqiang

2018-01-01

Micro-blogging systems have become one of the most important ways for information sharing. Network structure and users’ interactions such as forwarding behaviors have aroused considerable research attention, while mention, as a key feature in micro-blogging platforms which can improve the visibility of a message and direct it to a particular user beyond the underlying social structure, is seldom studied in previous works. In this paper, we empirically study the mention effect in information diffusion, using the dataset from a population-scale social media website. We find that users with high number of followers would receive much more mentions than others. We further investigate the effect of mention in information diffusion by examining the response probability with respect to the number of mentions in a message and observe a saturation at around 5 mentions. Furthermore, we find that the response probability is the highest when a reciprocal followship exists between users, and one is more likely to receive a target user’s response if they have similar social status. To illustrate these findings, we propose the response prediction task and formulate it as a binary classification problem. Extensive evaluation demonstrates the effectiveness of discovered factors. Our results have consequences for the understanding of human dynamics on the social network, and potential implications for viral marketing and public opinion monitoring. PMID:29558498

Dichotomy of protective cellular immune responses to human visceral leishmaniasis.

PubMed

Khalil, E A G; Ayed, N B; Musa, A M; Ibrahim, M E; Mukhtar, M M; Zijlstra, E E; Elhassan, I M; Smith, P G; Kieny, P M; Ghalib, H W; Zicker, F; Modabber, F; Elhassan, A M

2005-05-01

Healing/protective responses in human visceral leishmaniasis (VL) are associated with stimulation/production of Th1 cytokines, such as interferon IFN-gamma, and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non-endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non-reactivity following injection with one of four doses of Alum-precipitated autoclaved Leishmania major (Alum/ALM) +/- bacille Calmette-Guerin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side-effects and without an increase in antileishmanial antibodies or interleukin (IL)-5. Five volunteers (5/44; 11.4%) had significant IFN-gamma production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples (P = 0.001) but were LST non-reactive. On day 45, more than half the volunteers (26/44; 59.0%) had significantly high LST indurations (mean 9.2 +/- 2.7 mm) and high IFN-gamma levels (mean 1008 +/- 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen-induced IFN-gamma production (mean 873 +/- 290; median 902; P = 0.001), but were non-reactive in LST. An additional five volunteers (5/44; 11.4%) had low IFN-gamma levels (mean 110 +/- 124 pg/ml; median 80) and were non-reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN-gamma levels, but significant LST induration (mean 10 +/- 2.9 mm; median 11). By day 90 the majority of volunteers (27/44; 61.4%) had significant LST induration (mean 10.8 +/- 9.9 mm; P < 0.001), but low levels of L. donovani antigen-induced IFN-gamma (mean 66.0 +/- 62 pg/ml; P > 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN-gamma and LST induration, while five volunteers had low levels of IFN-gamma (<100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow-up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN-gamma production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN-gamma response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy.

Item response theory analysis of the Pain Self-Efficacy Questionnaire.

PubMed

Costa, Daniel S J; Asghari, Ali; Nicholas, Michael K

2017-01-01

The Pain Self-Efficacy Questionnaire (PSEQ) is a 10-item instrument designed to assess the extent to which a person in pain believes s/he is able to accomplish various activities despite their pain. There is strong evidence for the validity and reliability of both the full-length PSEQ and a 2-item version. The purpose of this study is to further examine the properties of the PSEQ using an item response theory (IRT) approach. We used the two-parameter graded response model to examine the category probability curves, and location and discrimination parameters of the 10 PSEQ items. In item response theory, responses to a set of items are assumed to be probabilistically determined by a latent (unobserved) variable. In the graded-response model specifically, item response threshold (the value of the latent variable for which adjacent response categories are equally likely) and discrimination parameters are estimated for each item. Participants were 1511 mixed, chronic pain patients attending for initial assessment at a tertiary pain management centre. All items except item 7 ('I can cope with my pain without medication') performed well in IRT analysis, and the category probability curves suggested that participants used the 7-point response scale consistently. Items 6 ('I can still do many of the things I enjoy doing, such as hobbies or leisure activity, despite pain'), 8 ('I can still accomplish most of my goals in life, despite the pain') and 9 ('I can live a normal lifestyle, despite the pain') captured higher levels of the latent variable with greater precision. The results from this IRT analysis add to the body of evidence based on classical test theory illustrating the strong psychometric properties of the PSEQ. Despite the relatively poor performance of Item 7, its clinical utility warrants its retention in the questionnaire. The strong psychometric properties of the PSEQ support its use as an effective tool for assessing self-efficacy in people with pain. Copyright © 2016 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Determining the Probability of Violating Upper-Level Wind Constraints for the Launch of Minuteman Ill Ballistic Missiles At Vandenberg Air Force Base

NASA Technical Reports Server (NTRS)

Shafer, Jaclyn A.; Brock, Tyler M.

2013-01-01

The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman Ill ballistic missile. The 30 OSSWF requested the Applied Meteorology Unit (AMU) analyze VAFB sounding data to determine the probability of violating (PoV) upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a graphical user interface (GUI) that will calculate the PoV of each constraint on the day of launch. The AMU suggested also including forecast sounding data from the Rapid Refresh (RAP) model. This would provide further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours, and help to improve the overall upper winds forecast on launch day.

A geological perspective on potential future sea-level rise

PubMed Central

Rohling, Eelco J.; Haigh, Ivan D.; Foster, Gavin L.; Roberts, Andrew P.; Grant, Katharine M.

2013-01-01

During ice-age cycles, continental ice volume kept pace with slow, multi-millennial scale, changes in climate forcing. Today, rapid greenhouse gas (GHG) increases have outpaced ice-volume responses, likely committing us to > 9 m of long-term sea-level rise (SLR). We portray a context of naturally precedented SLR from geological evidence, for comparison with historical observations and future projections. This context supports SLR of up to 0.9 (1.8) m by 2100 and 2.7 (5.0) m by 2200, relative to 2000, at 68% (95%) probability. Historical SLR observations and glaciological assessments track the upper 68% limit. Hence, modern change is rapid by past interglacial standards but within the range of ‘normal’ processes. The upper 95% limit offers a useful low probability/high risk value. Exceedance would require conditions without natural interglacial precedents, such as catastrophic ice-sheet collapse, or activation of major East Antarctic mass loss at sustained CO2 levels above 1000 ppmv. PMID:24336564

Failure probability under parameter uncertainty.

PubMed

Gerrard, R; Tsanakas, A

2011-05-01

In many problems of risk analysis, failure is equivalent to the event of a random risk factor exceeding a given threshold. Failure probabilities can be controlled if a decisionmaker is able to set the threshold at an appropriate level. This abstract situation applies, for example, to environmental risks with infrastructure controls; to supply chain risks with inventory controls; and to insurance solvency risks with capital controls. However, uncertainty around the distribution of the risk factor implies that parameter error will be present and the measures taken to control failure probabilities may not be effective. We show that parameter uncertainty increases the probability (understood as expected frequency) of failures. For a large class of loss distributions, arising from increasing transformations of location-scale families (including the log-normal, Weibull, and Pareto distributions), the article shows that failure probabilities can be exactly calculated, as they are independent of the true (but unknown) parameters. Hence it is possible to obtain an explicit measure of the effect of parameter uncertainty on failure probability. Failure probability can be controlled in two different ways: (1) by reducing the nominal required failure probability, depending on the size of the available data set, and (2) by modifying of the distribution itself that is used to calculate the risk control. Approach (1) corresponds to a frequentist/regulatory view of probability, while approach (2) is consistent with a Bayesian/personalistic view. We furthermore show that the two approaches are consistent in achieving the required failure probability. Finally, we briefly discuss the effects of data pooling and its systemic risk implications. © 2010 Society for Risk Analysis.

Clinicians' perceptions of the value of ventilation-perfusion scans.

PubMed

Siegel, Alan; Holtzman, Stephen R; Bettmann, Michael A; Black, William C

2004-07-01

The goal of this investigation was to understand clinicians' perceptions of the probability of pulmonary embolism as a function of V/Q scan results of normal, low, intermediate, and high probability. A questionnaire was developed and distributed to 429 clinicians at a single academic medical center. The response rate was 44% (188 of 429). The questions included level of training, specialty, probability of PE given 1 of the 4 V/Q scan results, and estimations of the charges for V/Q scanning and pulmonary angiography, and estimations of the risks of pulmonary angiography. The medians and ranges for the probability of pulmonary embolism given a normal, low, intermediate, and high probability V/Q scan result were 2.5% (0-30), 12.5% (0.5-52.5), 41.25% (5-75), and 85% (5-100), respectively. Eleven percent (21 of 188) of the respondents listed the probability of PE in patients with a low probability V/Q scan as being 5% or less, and 33% (62 of 188) listed the probability of PE given an intermediate probability scan as 50% or greater. The majority correctly identified the rate of serious complications of pulmonary arteriography, but many respondents underestimated the charge for V/Q scans and pulmonary arteriography. A substantial minority of clinicians do not understand the probability of pulmonary embolism in patients with low and intermediate probability ventilation-perfusion scans. More quantitative reporting of results is recommended. This could be particularly important because VQ scans are used less frequently but are still needed in certain clinical situations.

Environmental contaminants in tissues, foods, and feces of California condors

USGS Publications Warehouse

Wiemeyer, Stanley N.; Krynitsky, A.J.; Wilbur, S.R.; Wilbur, Sanford R.; Jackson, Jerome A.

1983-01-01

Two wild California Condors contained moderate to high levels of DDE in their tissues. The levels found could be high enough to cause reproductive problems in adult condors, if the assumption is made that condors are as susceptible to DDE as many other species of birds of prey. Other organochlorines occurred at low levels and probably were not high enough to cause deleterious effects. Metal residues in tissues of one bird were generally low except for copper in liver and lead in bone. Normal background levels of these metals in cathartids are unknown, making interpretation of the results difficult. Organochlorine residues in biopsy samples from a captive condor were low and probably would not have an adverse effect on reproduction if the bird were used for captive breeding. Organochlorines were not detected in food items used in the supplemental feeding program, and mercury and lead residues in these items were generally low. Information is needed on current contaminant levels in natural condor prey throughout the condor range.

The effect of floods on anemia among reproductive age women in Afghanistan.

PubMed

Oskorouchi, Hamid Reza; Nie, Peng; Sousa-Poza, Alfonso

2018-01-01

This study uses biomarker information from the 2013 National Nutrition Survey Afghanistan and satellite precipitation driven modeling results from the Global Flood Monitoring System to analyze how floods affect the probability of anemia in Afghan women of reproductive age (15-49). In addition to establishing a causal relation between the two by exploiting the quasi-random variation of floods in different districts and periods, the analysis demonstrates that floods have a significant positive effect on the probability of anemia through two possible transmission mechanisms. The first is a significant effect on inflammation, probably related to water borne diseases carried by unsafe drinking water, and the second is a significant negative effect on retinol concentrations. Because the effect of floods on anemia remains significant even after we control for anemia's most common causes, we argue that the condition may also be affected by elevated levels of psychological stress.

The effect of floods on anemia among reproductive age women in Afghanistan

PubMed Central

2018-01-01

This study uses biomarker information from the 2013 National Nutrition Survey Afghanistan and satellite precipitation driven modeling results from the Global Flood Monitoring System to analyze how floods affect the probability of anemia in Afghan women of reproductive age (15–49). In addition to establishing a causal relation between the two by exploiting the quasi-random variation of floods in different districts and periods, the analysis demonstrates that floods have a significant positive effect on the probability of anemia through two possible transmission mechanisms. The first is a significant effect on inflammation, probably related to water borne diseases carried by unsafe drinking water, and the second is a significant negative effect on retinol concentrations. Because the effect of floods on anemia remains significant even after we control for anemia’s most common causes, we argue that the condition may also be affected by elevated levels of psychological stress. PMID:29425219

Greenhouse-gas emission targets for limiting global warming to 2 degrees C.

PubMed

Meinshausen, Malte; Meinshausen, Nicolai; Hare, William; Raper, Sarah C B; Frieler, Katja; Knutti, Reto; Frame, David J; Allen, Myles R

2009-04-30

More than 100 countries have adopted a global warming limit of 2 degrees C or below (relative to pre-industrial levels) as a guiding principle for mitigation efforts to reduce climate change risks, impacts and damages. However, the greenhouse gas (GHG) emissions corresponding to a specified maximum warming are poorly known owing to uncertainties in the carbon cycle and the climate response. Here we provide a comprehensive probabilistic analysis aimed at quantifying GHG emission budgets for the 2000-50 period that would limit warming throughout the twenty-first century to below 2 degrees C, based on a combination of published distributions of climate system properties and observational constraints. We show that, for the chosen class of emission scenarios, both cumulative emissions up to 2050 and emission levels in 2050 are robust indicators of the probability that twenty-first century warming will not exceed 2 degrees C relative to pre-industrial temperatures. Limiting cumulative CO(2) emissions over 2000-50 to 1,000 Gt CO(2) yields a 25% probability of warming exceeding 2 degrees C-and a limit of 1,440 Gt CO(2) yields a 50% probability-given a representative estimate of the distribution of climate system properties. As known 2000-06 CO(2) emissions were approximately 234 Gt CO(2), less than half the proven economically recoverable oil, gas and coal reserves can still be emitted up to 2050 to achieve such a goal. Recent G8 Communiqués envisage halved global GHG emissions by 2050, for which we estimate a 12-45% probability of exceeding 2 degrees C-assuming 1990 as emission base year and a range of published climate sensitivity distributions. Emissions levels in 2020 are a less robust indicator, but for the scenarios considered, the probability of exceeding 2 degrees C rises to 53-87% if global GHG emissions are still more than 25% above 2000 levels in 2020.

Branched chains support postoperative protein synthesis.

PubMed

Cerra, F B; Upson, D; Angelico, R; Wiles, C; Lyons, J; Faulkenbach, L; Paysinger, J

1982-08-01

A blinded, prospective trial of the effects of branched-chain amino acid (BcAA)-enriched total parenteral nutrition (TPN) versus standard TPN was undertaken in nonseptic noncirrhotic abdominal surgery patients and patients with multiple traumatic injuries. The study reflected data from the immediate 7-day postoperative period. With isocaloric and isonitrogenous input, the BcAA-TPN patients achieved positive nitrogen balance on day 3. Although the urinary nitrogen output was decreased by day 3 in BcAA-TPN, the plasma BcAA levels did not increase until day 6. With no change in 3-methylhistidine urinary excretion, the early nitrogen retention with BcAA-TPN probably reflects a stimulation of protein synthesis. The ability to favorably modulate the metabolic stress response with alternate fuels has become a clinical reality.

The Between-Population Genetic Architecture of Growth, Maturation, and Plasticity in Atlantic Salmon

PubMed Central

Debes, Paul Vincent; Fraser, Dylan John; Yates, Matthew; Hutchings, Jeffrey A.

2014-01-01

The between-population genetic architecture for growth and maturation has not been examined in detail for many animal species despite its central importance in understanding hybrid fitness. We studied the genetic architecture of population divergence in: (i) maturation probabilities at the same age; (ii) size at age and growth, while accounting for maturity status and sex; and (iii) growth plasticity in response to environmental factors, using divergent wild and domesticated Atlantic salmon (Salmo salar). Our work examined two populations and their multigenerational hybrids in a common experimental arrangement in which salinity and quantity of suspended sediments were manipulated to mimic naturally occurring environmental variation. Average specific growth rates across environments differed among crosses, maturity groups, and cross-by-maturity groups, but a growth-rate reduction in the presence of suspended sediments was equal for all groups. Our results revealed both additive and nonadditive outbreeding effects for size at age and for growth rates that differed with life stage, as well as the presence of different sex- and size-specific maturation probabilities between populations. The major implication of our work is that estimates of the genetic architecture of growth and maturation can be biased if one does not simultaneously account for temporal changes in growth and for different maturation probabilities between populations. Namely, these correlated traits interact differently within each population and between sexes and among generations, due to nonadditive effects and a level of independence in the genetic control for traits. Our results emphasize the challenges to investigating and predicting phenotypic changes resulting from between-population outbreeding. PMID:24473933

The between-population genetic architecture of growth, maturation, and plasticity in Atlantic salmon.

PubMed

Debes, Paul Vincent; Fraser, Dylan John; Yates, Matthew; Hutchings, Jeffrey A

2014-04-01

The between-population genetic architecture for growth and maturation has not been examined in detail for many animal species despite its central importance in understanding hybrid fitness. We studied the genetic architecture of population divergence in: (i) maturation probabilities at the same age; (ii) size at age and growth, while accounting for maturity status and sex; and (iii) growth plasticity in response to environmental factors, using divergent wild and domesticated Atlantic salmon (Salmo salar). Our work examined two populations and their multigenerational hybrids in a common experimental arrangement in which salinity and quantity of suspended sediments were manipulated to mimic naturally occurring environmental variation. Average specific growth rates across environments differed among crosses, maturity groups, and cross-by-maturity groups, but a growth-rate reduction in the presence of suspended sediments was equal for all groups. Our results revealed both additive and nonadditive outbreeding effects for size at age and for growth rates that differed with life stage, as well as the presence of different sex- and size-specific maturation probabilities between populations. The major implication of our work is that estimates of the genetic architecture of growth and maturation can be biased if one does not simultaneously account for temporal changes in growth and for different maturation probabilities between populations. Namely, these correlated traits interact differently within each population and between sexes and among generations, due to nonadditive effects and a level of independence in the genetic control for traits. Our results emphasize the challenges to investigating and predicting phenotypic changes resulting from between-population outbreeding.

Branched-chain amino acids and brain function.

PubMed

Fernstrom, John D

2005-06-01

Branched-chain amino acids (BCAAs) influence brain function by modifying large, neutral amino acid (LNAA) transport at the blood-brain barrier. Transport is shared by several LNAAs, notably the BCAAs and the aromatic amino acids (ArAAs), and is competitive. Consequently, when plasma BCAA concentrations rise, which can occur in response to food ingestion or BCAA administration, or with the onset of certain metabolic diseases (e.g., uncontrolled diabetes), brain BCAA concentrations rise, and ArAA concentrations decline. Such effects occur acutely and chronically. Such reductions in brain ArAA concentrations have functional consequences: biochemically, they reduce the synthesis and the release of neurotransmitters derived from ArAAs, notably serotonin (from tryptophan) and catecholamines (from tyrosine and phenylalanine). The functional effects of such neurochemical changes include altered hormonal function, blood pressure, and affective state. Although the BCAAs thus have biochemical and functional effects in the brain, few attempts have been made to characterize time-course or dose-response relations for such effects. And, no studies have attempted to identify levels of BCAA intake that might produce adverse effects on the brain. The only "model" of very high BCAA exposure is a very rare genetic disorder, maple syrup urine disease, a feature of which is substantial brain dysfunction but that probably cannot serve as a useful model for excessive BCAA intake by normal individuals. Given the known biochemical and functional effects of the BCAAs, it should be a straightforward exercise to design studies to assess dose-response relations for biochemical and functional effects and, in this context, to explore for adverse effect thresholds.

Neural correlates of decision making with explicit information about probabilities and incentives in elderly healthy subjects.

PubMed

Labudda, Kirsten; Woermann, Friedrich G; Mertens, Markus; Pohlmann-Eden, Bernd; Markowitsch, Hans J; Brand, Matthias

2008-06-01

Recent functional neuroimaging and lesion studies demonstrate the involvement of the orbitofrontal/ventromedial prefrontal cortex as a key structure in decision making processes. This region seems to be particularly crucial when contingencies between options and consequences are unknown but have to be learned by the use of feedback following previous decisions (decision making under ambiguity). However, little is known about the neural correlates of decision making under risk conditions in which information about probabilities and potential outcomes is given. In the present study, we used functional magnetic resonance imaging to measure blood-oxygenation-level-dependent (BOLD) responses in 12 subjects during a decision making task. This task provided explicit information about probabilities and associated potential incentives. The responses were compared to BOLD signals in a control condition without information about incentives. In contrast to previous decision making studies, we completely removed the outcome phase following a decision to exclude the potential influence of feedback previously received on current decisions. The results indicate that the integration of information about probabilities and incentives leads to activations within the dorsolateral prefrontal cortex, the posterior parietal lobe, the anterior cingulate and the right lingual gyrus. We assume that this pattern of activation is due to the involvement of executive functions, conflict detection mechanisms and arithmetic operations during the deliberation phase of decisional processes that are based on explicit information.

The Probability of Exceedance as a Nonparametric Person-Fit Statistic for Tests of Moderate Length

ERIC Educational Resources Information Center

Tendeiro, Jorge N.; Meijer, Rob R.

2013-01-01

To classify an item score pattern as not fitting a nonparametric item response theory (NIRT) model, the probability of exceedance (PE) of an observed response vector x can be determined as the sum of the probabilities of all response vectors that are, at most, as likely as x, conditional on the test's total score. Vector x is to be considered…

Predictors of Local Control After Single-Dose Stereotactic Image-Guided Intensity-Modulated Radiotherapy for Extracranial Metastases

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

Greco, Carlo; Zelefsky, Michael J., E-mail: zelefskm@mskcc.or; Lovelock, Michael

2011-03-15

Purpose: To report tumor local control after treatment with single-dose image-guided intensity-modulated radiotherapy (SD-IGRT) to extracranial metastatic sites. Methods and Materials: A total of 126 metastases in 103 patients were treated with SD-IGRT to prescription doses of 18-24 Gy (median, 24 Gy) between 2004 and 2007. Results: The overall actuarial local relapse-free survival (LRFS) rate was 64% at a median follow-up of 18 months (range, 2-45 months). The median time to failure was 9.6 months (range, 1-23 months). On univariate analysis, LRFS was significantly correlated with prescription dose (p = 0.029). Stratification by dose into high (23 to 24 Gy),more » intermediate (21 to 22 Gy), and low (18 to 20 Gy) dose levels revealed highly significant differences in LRFS between high (82%) and low doses (25%) (p < 0.0001). Overall, histology had no significant effect on LRFS (p = 0.16). Renal cell histology displayed a profound dose-response effect, with 80% LRFS at the high dose level (23 to 24 Gy) vs. 37% with low doses ({<=}22 Gy) (p = 0.04). However, for patients who received the high dose level, histology was not a statistically significant predictor of LRFS (p = 0.90). Target organ (bone vs. lymph node vs. soft tissues) (p = 0.5) and planning target volume size (p = 0.55) were not found to be associated with long-term LRFS probability. Multivariate Cox regression analysis confirmed prescription dose to be a significant predictor of LRFS (p = 0.003). Conclusion: High-dose SD-IGRT is a noninvasive procedure resulting in high probability of local tumor control. Single-dose IGRT may be effectively used to locally control metastatic deposits regardless of histology and target organ, provided sufficiently high doses (> 22 Gy) of radiation are delivered.« less

Predictors of business return in New Orleans after Hurricane Katrina.

PubMed

Lam, Nina S N; Arenas, Helbert; Pace, Kelley; LeSage, James; Campanella, Richard

2012-01-01

We analyzed the business reopening process in New Orleans after Hurricane Katrina, which hit the region on August 29, 2005, to better understand what the major predictors were and how their impacts changed through time. A telephone survey of businesses in New Orleans was conducted in October 2007, 26 months after Hurricane Katrina. The data were analyzed using a modified spatial probit regression model to evaluate the importance of each predictor variable through time. The results suggest that the two most important reopening predictors throughout all time periods were the flood depth at the business location and business size as represented by its wages in a logarithmic form. Flood depth was a significant negative predictor and had the largest marginal effects on the reopening probabilities. Smaller businesses had lower reopening probabilities than larger ones. However, the nonlinear response of business size to the reopening probability suggests that recovery aid would be most effective for smaller businesses than for larger ones. The spatial spillovers effect was a significant positive predictor but only for the first nine months. The findings show clearly that flood protection is the overarching issue for New Orleans. A flood protection plan that reduces the vulnerability and length of flooding would be the first and foremost step to mitigate the negative effects from climate-related hazards and enable speedy recovery. The findings cast doubt on the current coastal protection efforts and add to the current debate of whether coastal Louisiana will be sustainable or too costly to protect from further land loss and flooding given the threat of sea-level rise. Finally, a plan to help small businesses to return would also be an effective strategy for recovery, and the temporal window of opportunity that generates the greatest impacts would be the first 6∼9 months after the disaster.

Predictors of Business Return in New Orleans after Hurricane Katrina

PubMed Central

Lam, Nina S. N.; Arenas, Helbert; Pace, Kelley; LeSage, James; Campanella, Richard

2012-01-01

We analyzed the business reopening process in New Orleans after Hurricane Katrina, which hit the region on August 29, 2005, to better understand what the major predictors were and how their impacts changed through time. A telephone survey of businesses in New Orleans was conducted in October 2007, 26 months after Hurricane Katrina. The data were analyzed using a modified spatial probit regression model to evaluate the importance of each predictor variable through time. The results suggest that the two most important reopening predictors throughout all time periods were the flood depth at the business location and business size as represented by its wages in a logarithmic form. Flood depth was a significant negative predictor and had the largest marginal effects on the reopening probabilities. Smaller businesses had lower reopening probabilities than larger ones. However, the nonlinear response of business size to the reopening probability suggests that recovery aid would be most effective for smaller businesses than for larger ones. The spatial spillovers effect was a significant positive predictor but only for the first nine months. The findings show clearly that flood protection is the overarching issue for New Orleans. A flood protection plan that reduces the vulnerability and length of flooding would be the first and foremost step to mitigate the negative effects from climate-related hazards and enable speedy recovery. The findings cast doubt on the current coastal protection efforts and add to the current debate of whether coastal Louisiana will be sustainable or too costly to protect from further land loss and flooding given the threat of sea-level rise. Finally, a plan to help small businesses to return would also be an effective strategy for recovery, and the temporal window of opportunity that generates the greatest impacts would be the first 6∼9 months after the disaster. PMID:23133530

Botulinum toxin treatment of pain syndromes -an evidence based review.

PubMed

Safarpour, Yasaman; Jabbari, Bahman

2018-06-01

This review evaluates the existing level of evidence for efficacy of BoNTs in different pain syndromes using the recommended efficacy criteria from the Assessment and Therapeutic Subcommittee of the American Academy of Neurology. There is a level A evidence (effective) for BoNT therapy in post-herpetic neuralgia, trigeminal neuralgia, and posttraumatic neuralgia. There is a level B evidence (probably effective) for diabetic neuropathy, plantar fasciitis, piriformis syndrome, pain associated with total knee arthroplasty, male pelvic pain syndrome, chronic low back pain, male pelvic pain, and neuropathic pain secondary to traumatic spinal cord injury. BoNTs are possibly effective (Level C -one class II study) for female pelvic pain, painful knee osteoarthritis, post-operative pain in children with cerebral palsy after adductor release surgery, anterior knee pain with vastus lateralis imbalance. There is a level B evidence (one class I study) that BoNT treatment is probably ineffective in carpal tunnel syndrome. For myofascial pain syndrome, the level of evidence is U (undetermined) due to contradicting results. More high quality (Class I) studies and studies with different types of BoNTs are needed for better understanding of the role of BoNTs in pain syndromes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Statistical methods for incomplete data: Some results on model misspecification.

PubMed

McIsaac, Michael; Cook, R J

2017-02-01

Inverse probability weighted estimating equations and multiple imputation are two of the most studied frameworks for dealing with incomplete data in clinical and epidemiological research. We examine the limiting behaviour of estimators arising from inverse probability weighted estimating equations, augmented inverse probability weighted estimating equations and multiple imputation when the requisite auxiliary models are misspecified. We compute limiting values for settings involving binary responses and covariates and illustrate the effects of model misspecification using simulations based on data from a breast cancer clinical trial. We demonstrate that, even when both auxiliary models are misspecified, the asymptotic biases of double-robust augmented inverse probability weighted estimators are often smaller than the asymptotic biases of estimators arising from complete-case analyses, inverse probability weighting or multiple imputation. We further demonstrate that use of inverse probability weighting or multiple imputation with slightly misspecified auxiliary models can actually result in greater asymptotic bias than the use of naïve, complete case analyses. These asymptotic results are shown to be consistent with empirical results from simulation studies.

Effects of distractors and force feedback on an aimed movement task in a CDTI environment

NASA Astrophysics Data System (ADS)

Monk, Kevin J., II

New onboard technologies will be required for future cockpits to support the altered responsibilities of pilots under the NextGen program. Effective Cockpit Displays of Information (CD Tis) should provide more flexibility to pilots en route and reduce the probability of conflicts. However, precise input from pilots can be difficult due to the unstable environment in the cockpit. The present study used a non-traditional input device (Novint Falcon) to examine the effect of force feedback on operator performance during point-and-click movements in a CDTI environment when distractors are present. Twelve participants performed point-and-click tasks with varying amounts of force feedback, distractor locations, target sizes, distances, and movement directions. Overall movement times (OMTs) were recorded. Results demonstrated that force feedback did not reduce or match OMTs relative to the computer mouse. However, significant interactions with other target variables highlighted conditional differences between the force levels, as well as distractor effects.

Effect Sizes and their Intervals: The Two-Level Repeated Measures Case

ERIC Educational Resources Information Center

Algina, James; Keselman, H. J.; Penfield, Randall D.

2005-01-01

Probability coverage for eight different confidence intervals (CIs) of measures of effect size (ES) in a two-level repeated measures design was investigated. The CIs and measures of ES differed with regard to whether they used least squares or robust estimates of central tendency and variability, whether the end critical points of the interval…

3-NP-induced Huntington's-like disease impairs Nrf2 activation without loss of cardiac function in aged rats.

PubMed

Silva-Palacios, A; Ostolga-Chavarría, M; Buelna-Chontal, M; Garibay, C; Hernández-Reséndiz, S; Roldán, F J; Flores, P L; Luna-López, A; Königsberg, M; Zazueta, C

2017-10-01

Cardiovascular diseases (CVDs) are one of the leading causes of death in patients over 60years with Huntington's disease (HD). Here, we investigated if age-related oxidative stress (OS) is a relevant factor to develop cardiac damage in an in vivo model of striatal neurodegeneration induced by 3-nitropropionic acid (3-NP). We also evaluated the potential effect of tert-butylhydroquinone (tBHQ) to increase the Nrf2-regulated antioxidant response in hearts from adult and aged rats intoxicated with 3-NP. Our results showed that 3-NP-treatment did not induce cardiac dysfunction, neither in adult nor in aged rats. However, at the cellular level, adult animals showed higher susceptibility to 3-NP-induced damage than aged rats, which suggest that chronic oxidative stress ongoing during aging might have induced an hormetic response that probably prevented from further 3-NP damage. We also found that the oxidative unbalance concurs with unresponsiveness of the Nrf2-mediated antioxidant response in old animals. Copyright © 2017 Elsevier Inc. All rights reserved.

The framing effect and skin conductance responses.

PubMed

Ring, Patrick

2015-01-01

Individuals often rely on simple heuristics when they face complex choice situations under uncertainty. Traditionally, it has been proposed that cognitive processes are the main driver to evaluate different choice options and to finally reach a decision. Growing evidence, however, highlights a strong interrelation between judgment and decision-making (JDM) on the one hand, and emotional processes on the other hand. This also seems to apply to judgmental heuristics, i.e., decision processes that are typically considered to be fast and intuitive. In this study, participants are exposed to different probabilities of receiving an unpleasant electric shock. Information about electric shock probabilities is either positively or negatively framed. Integrated skin conductance responses (ISCRs) while waiting for electric shock realization are used as an indicator for participants' emotional arousal. This measure is compared to objective probabilities. I find evidence for a relation between emotional body reactions measured by ISCRs and the framing effect. Under negative frames, participants show significantly higher ISCRs while waiting for an electric shock to be delivered than under positive frames. This result might contribute to a better understanding of the psychological processes underlying JDM. Further studies are necessary to reveal the causality underlying this finding, i.e., whether emotional processes influence JDM or vice versa.

Effects of impurities on crystal growth in fructose crystallization

NASA Astrophysics Data System (ADS)

Chu, Y. D.; Shiau, L. D.; Berglund, K. A.

1989-10-01

The influence of impurities on the crystallization of anhydrous fructose from aqueous solution was studied. The growth kinetics of fructose crystals in the fructose-water-glucose and fructose-water-difructose dianhydrides systems were investigated using photomicroscopic contact nucleation techniques. Glucose is the major impurity likely to be present in fructose syrup formed during corn wet milling, while several difructose dianhydrides are formed in situ under crystallization conditions and have been proposed as a cause in the decrease of overall yields. Both sets of impurities were found to cause inhibition of crystal growth, but the mechanisms responsible in each case are different. It was found that the presence of glucose increases the solubility of fructose in water and thus lowers the supersaturation of the solution. This is probably the main effect responsible for the decrease of crystal growth. Since the molecular structures of difructose dianhydrides are similar to that of fructose, they are probably "tailor-made" impurities. The decrease of crystal growth is probably caused by the incorporation of these impurities into or adsorption to the crystal surface which would accept fructose molecules in the orientation that existed in the difructose dianhydride.

The effectiveness of tape playbacks in estimating Black Rail densities

USGS Publications Warehouse

Legare, M.; Eddleman, W.R.; Buckley, P.A.; Kelly, C.

1999-01-01

Tape playback is often the only efficient technique to survey for secretive birds. We measured the vocal responses and movements of radio-tagged black rails (Laterallus jamaicensis; 26 M, 17 F) to playback of vocalizations at 2 sites in Florida during the breeding seasons of 1992-95. We used coefficients from logistic regression equations to model probability of a response conditional to the birds' sex. nesting status, distance to playback source, and time of survey. With a probability of 0.811, nonnesting male black rails were ))lost likely to respond to playback, while nesting females were the least likely to respond (probability = 0.189). We used linear regression to determine daily, monthly and annual variation in response from weekly playback surveys along a fixed route during the breeding seasons of 1993-95. Significant sources of variation in the regression model were month (F3.48 = 3.89, P = 0.014), year (F2.48 = 9.37, P < 0.001), temperature (F1.48 = 5.44, P = 0.024), and month X year (F5.48 = 2.69, P = 0.031). The model was highly significant (P < 0.001) and explained 54% of the variation of mean response per survey period (r2 = 0.54). We combined response probability data from radiotagged black rails with playback survey route data to provide a density estimate of 0.25 birds/ha for the St. Johns National Wildlife Refuge. The relation between the number of black rails heard during playback surveys to the actual number present was influenced by a number of variables. We recommend caution when making density estimates from tape playback surveys

Reward Expectation Modulates Feedback-Related Negativity and EEG Spectra

PubMed Central

Cohen, Michael X; Elger, Christian E.; Ranganath, Charan

2007-01-01

The ability to evaluate outcomes of previous decisions is critical to adaptive decision-making. The feedback-related negativity (FRN) is an event-related potential (ERP) modulation that distinguishes losses from wins, but little is known about the effects of outcome probability on these ERP responses. Further, little is known about the frequency characteristics of feedback processing, for example, event-related oscillations and phase synchronizations. Here, we report an EEG experiment designed to address these issues. Subjects engaged in a probabilistic reinforcement learning task in which we manipulated, across blocks, the probability of winning and losing to each of two possible decision options. Behaviorally, all subjects quickly adapted their decision-making to maximize rewards. ERP analyses revealed that the probability of reward modulated neural responses to wins, but not to losses. This was seen both across blocks as well as within blocks, as learning progressed. Frequency decomposition via complex wavelets revealed that EEG responses to losses, compared to wins, were associated with enhanced power and phase coherence in the theta frequency band. As in the ERP analyses, power and phase coherence values following wins but not losses were modulated by reward probability. Some findings between ERP and frequency analyses diverged, suggesting that these analytic approaches provide complementary insights into neural processing. These findings suggest that the neural mechanisms of feedback processing may differ between wins and losses. PMID:17257860

Time- and Space-Order Effects in Timed Discrimination of Brightness and Size of Paired Visual Stimuli

ERIC Educational Resources Information Center

Patching, Geoffrey R.; Englund, Mats P.; Hellstrom, Ake

2012-01-01

Despite the importance of both response probability and response time for testing models of choice, there is a dearth of chronometric studies examining systematic asymmetries that occur over time- and space-orders in the method of paired comparisons. In this study, systematic asymmetries in discriminating the magnitude of paired visual stimuli are…

Ruptured-yolk peritonitis and organochlorine residues in a royal tern

USGS Publications Warehouse

Blus, L.J.; Locke, L.N.; Stafford, C.J.

1977-01-01

Ruptured-yolk peritonitis was responsible for the death of a royal tern. Lodgment of eggs in the oviduct was probably due to reverse peristalsis brought about by breakage of the thin-shelled eggs and secondary bacterial infection. The thin shells were apparently not related to the low levels of DDE and other organochlorine pollutants found in tissues and egg contents.

Multimodal Interactions in Sensory-Motor Processing

DTIC Science & Technology

1992-06-30

Luce & Green,1972; Wandell and Luce, 1978; Blake, Martens, Garrett & Westendorf , 1980; Fidell, 1970; Fournier & Eriksen, 1990; Rose, Blake and Holper...1988; i Westendorf and Blake, 1988) or at the level of response selection or execution (eg.,Diederich & Colonius, 1987; Eriksen and Schultz, 1977...Mathematical Statistics. Holden-Day, Inc. Oakland, CA. I Blake, R., Martens, W., Garrett, G., & Westendorf , D. (1980). Estimating probability summation for

A Violation of the Conditional Independence Assumption in the Two-High-Threshold Model of Recognition Memory

ERIC Educational Resources Information Center

Chen, Tina; Starns, Jeffrey J.; Rotello, Caren M.

2015-01-01

The 2-high-threshold (2HT) model of recognition memory assumes that test items result in distinct internal states: they are either detected or not, and the probability of responding at a particular confidence level that an item is "old" or "new" depends on the state-response mapping parameters. The mapping parameters are…

Neural Encoding and Integration of Learned Probabilistic Sequences in Avian Sensory-Motor Circuitry

PubMed Central

Brainard, Michael S.

2013-01-01

Many complex behaviors, such as human speech and birdsong, reflect a set of categorical actions that can be flexibly organized into variable sequences. However, little is known about how the brain encodes the probabilities of such sequences. Behavioral sequences are typically characterized by the probability of transitioning from a given action to any subsequent action (which we term “divergence probability”). In contrast, we hypothesized that neural circuits might encode the probability of transitioning to a given action from any preceding action (which we term “convergence probability”). The convergence probability of repeatedly experienced sequences could naturally become encoded by Hebbian plasticity operating on the patterns of neural activity associated with those sequences. To determine whether convergence probability is encoded in the nervous system, we investigated how auditory-motor neurons in vocal premotor nucleus HVC of songbirds encode different probabilistic characterizations of produced syllable sequences. We recorded responses to auditory playback of pseudorandomly sequenced syllables from the bird's repertoire, and found that variations in responses to a given syllable could be explained by a positive linear dependence on the convergence probability of preceding sequences. Furthermore, convergence probability accounted for more response variation than other probabilistic characterizations, including divergence probability. Finally, we found that responses integrated over >7–10 syllables (∼700–1000 ms) with the sign, gain, and temporal extent of integration depending on convergence probability. Our results demonstrate that convergence probability is encoded in sensory-motor circuitry of the song-system, and suggest that encoding of convergence probability is a general feature of sensory-motor circuits. PMID:24198363

When is Pharmacogenetic Testing for Antidepressant Response Ready for the Clinic? A Cost-effectiveness Analysis Based on Data from the STAR*D Study

PubMed Central

Perlis, Roy H.; Patrick, Amanda; Smoller, Jordan W.; Wang, Philip S.

2009-01-01

The potential of personalized medicine to transform the treatment of mood disorders has been widely touted in psychiatry, but has not been quantified. We estimated the costs and benefits of a putative pharmacogenetic test for antidepressant response in the treatment of major depressive disorder (MDD) from the societal perspective. Specifically, we performed cost-effectiveness analyses using state-transition probability models incorporating probabilities from the multicenter STAR*D effectiveness study of MDD. Costs and quality-adjusted life years were compared for sequential antidepressant trials, with or without guidance from a pharmacogenetic test for differential response to selective serotonin reuptake inhibitors (SSRIs). Likely SSRI responders received an SSRI, while likely nonresponders received the norepinephrine/dopamine reuptake inhibitor bupropion. For a 40-year-old with major depressive disorder, applying the pharmacogenetic test and using the non-SSRI bupropion for those at higher risk for nonresponse cost $93,520 per additional quality-adjusted life-year (QALY) compared with treating all patients with an SSRI first and switching sequentially in the case of nonremission. Cost/QALY dropped below $50,000 for tests with remission rate ratios as low as 1.5, corresponding to odds ratios ~1.8–2.0. Tests for differential antidepressant response could thus become cost-effective under certain circumstances. These circumstances, particularly availability of alternative treatment strategies and test effect sizes, can be estimated and should be considered before these tests are broadly applied in clinical settings. PMID:19494805

Framing of outcome and probability of recurrence: breast cancer patients' choice of adjuvant chemotherapy (ACT) in hypothetical patient scenarios.

PubMed

Zimmermann, C; Baldo, C; Molino, A

2000-03-01

To examine the effects of framing of outcome and probabilities of cancer occurrence on the treatment preference which breast cancer patients indicate for hypothetical patient scenarios. A modified version of the Decision Board Instrument (Levine et al. 1992) was administered to 35 breast cancer patients with past ACT experience. Patients expressed their choice regarding ACT for six scenarios which were characterized by either negative or positive framing of outcome and by one of the three levels of probability of recurrence (high, medium, low). The framing had no influence on ACT choices over all three probability levels. The majority chose ACT for high and medium risk and one third switched from ACT to No ACT in the low-risk condition. This switch was statistically significant. Hypothetical treatment decisions against ACT occur only when the probability of recurrence is low and the benefit of ACT is small. This finding for patients with past experience of ACT is similar to those reported for other oncological patient groups still in treatment.

Probabilistic inversion of expert assessments to inform projections about Antarctic ice sheet responses

PubMed Central

Wong, Tony E.; Keller, Klaus

2017-01-01

The response of the Antarctic ice sheet (AIS) to changing global temperatures is a key component of sea-level projections. Current projections of the AIS contribution to sea-level changes are deeply uncertain. This deep uncertainty stems, in part, from (i) the inability of current models to fully resolve key processes and scales, (ii) the relatively sparse available data, and (iii) divergent expert assessments. One promising approach to characterizing the deep uncertainty stemming from divergent expert assessments is to combine expert assessments, observations, and simple models by coupling probabilistic inversion and Bayesian inversion. Here, we present a proof-of-concept study that uses probabilistic inversion to fuse a simple AIS model and diverse expert assessments. We demonstrate the ability of probabilistic inversion to infer joint prior probability distributions of model parameters that are consistent with expert assessments. We then confront these inferred expert priors with instrumental and paleoclimatic observational data in a Bayesian inversion. These additional constraints yield tighter hindcasts and projections. We use this approach to quantify how the deep uncertainty surrounding expert assessments affects the joint probability distributions of model parameters and future projections. PMID:29287095

Land use and land cover classification for rural residential areas in China using soft-probability cascading of multifeatures

NASA Astrophysics Data System (ADS)

Zhang, Bin; Liu, Yueyan; Zhang, Zuyu; Shen, Yonglin

2017-10-01

A multifeature soft-probability cascading scheme to solve the problem of land use and land cover (LULC) classification using high-spatial-resolution images to map rural residential areas in China is proposed. The proposed method is used to build midlevel LULC features. Local features are frequently considered as low-level feature descriptors in a midlevel feature learning method. However, spectral and textural features, which are very effective low-level features, are neglected. The acquisition of the dictionary of sparse coding is unsupervised, and this phenomenon reduces the discriminative power of the midlevel feature. Thus, we propose to learn supervised features based on sparse coding, a support vector machine (SVM) classifier, and a conditional random field (CRF) model to utilize the different effective low-level features and improve the discriminability of midlevel feature descriptors. First, three kinds of typical low-level features, namely, dense scale-invariant feature transform, gray-level co-occurrence matrix, and spectral features, are extracted separately. Second, combined with sparse coding and the SVM classifier, the probabilities of the different LULC classes are inferred to build supervised feature descriptors. Finally, the CRF model, which consists of two parts: unary potential and pairwise potential, is employed to construct an LULC classification map. Experimental results show that the proposed classification scheme can achieve impressive performance when the total accuracy reached about 87%.

Effect of withholding breastfeeding on the immune response to a live oral rotavirus vaccine in North Indian infants.

PubMed

Rongsen-Chandola, Temsunaro; Strand, Tor A; Goyal, Nidhi; Flem, Elmira; Rathore, Sudeep Singh; Arya, Alok; Winje, Brita Askeland; Lazarus, Robin; Shanmugasundaram, Elango; Babji, Sudhir; Sommerfelt, Halvor; Vainio, Kirsti; Kang, Gagandeep; Bhandari, Nita

2014-08-11

Interference from transplacental and breast milk antibodies may impede the performance of oral live vaccines. The effect of breastfeeding on the immunogenicity of Rotarix, a two-dose oral monovalent rotavirus vaccine, was examined in a community-based trial in New Delhi, India. Four hundred mother-infant pairs were randomized into two equal groups. Infants were aged 6-7 weeks at enrollment. Mothers were encouraged to either breastfeed or to withhold breastfeeding during the 30 min prior to and after each vaccine dose was administered. We collected blood specimens from infants at enrollment and 4 weeks after the second vaccine dose. Blood and breast milk specimens were obtained from mothers at baseline and breast milk specimens were collected at the time of the second vaccine dose. Seroconversion was defined as infant serum anti-VP6 IgA antibody level of ≥20 IU/mL 4 weeks after the second vaccine dose and a ≥4-fold rise from baseline. There was no difference in the proportion who seroconverted between the two groups (26% vs 27%; p=0.92). The levels of infant serum IgA, maternal serum and breast milk IgA and IgG anti-rotavirus antibodies predicted the anti-rotavirus IgA level in infants at end-study and explained approximately 10% of the variability of the immune response (r(2)=0.10, p<0.001). In this population, the immune response to Rotarix was not enhanced by withholding breastfeeding around the time of vaccination. Maternal anti-rotavirus antibodies explained little of the variability in the immune response to the vaccine. Factors other than maternal anti-rotavirus antibodies probably explain why infants in low-and middle-income settings respond poorly to live oral rotavirus vaccines. Copyright © 2014. Published by Elsevier Ltd.

Effects of vibration and shock on the performance of gas-bearing space-power Brayton cycle turbomachinery. Part 3: Sinusoidal and random vibration data reduction and evaluation, and random vibration probability analysis

NASA Technical Reports Server (NTRS)

Tessarzik, J. M.; Chiang, T.; Badgley, R. H.

1973-01-01

The random vibration response of a gas bearing rotor support system has been experimentally and analytically investigated in the amplitude and frequency domains. The NASA Brayton Rotating Unit (BRU), a 36,000 rpm, 10 KWe turbogenerator had previously been subjected in the laboratory to external random vibrations, and the response data recorded on magnetic tape. This data has now been experimentally analyzed for amplitude distribution and magnetic tape. This data has now been experimentally analyzed for amplitude distribution and frequency content. The results of the power spectral density analysis indicate strong vibration responses for the major rotor-bearing system components at frequencies which correspond closely to their resonant frequencies obtained under periodic vibration testing. The results of amplitude analysis indicate an increasing shift towards non-Gaussian distributions as the input level of external vibrations is raised. Analysis of axial random vibration response of the BRU was performed by using a linear three-mass model. Power spectral densities, the root-mean-square value of the thrust bearing surface contact were calculated for specified input random excitation.

Strategies for Improved Hospital Response to Mass Casualty Incidents.

PubMed

TariVerdi, Mersedeh; Miller-Hooks, Elise; Kirsch, Thomas

2018-03-19

Mass casualty incidents are a concern in many urban areas. A community's ability to cope with such events depends on the capacities and capabilities of its hospitals for handling a sudden surge in demand of patients with resource-intensive and specialized medical needs. This paper uses a whole-hospital simulation model to replicate medical staff, resources, and space for the purpose of investigating hospital responsiveness to mass casualty incidents. It provides details of probable demand patterns of different mass casualty incident types in terms of patient categories and arrival patterns, and accounts for related transient system behavior over the response period. Using the layout of a typical urban hospital, it investigates a hospital's capacity and capability to handle mass casualty incidents of various sizes with various characteristics, and assesses the effectiveness of designed demand management and capacity-expansion strategies. Average performance improvements gained through capacity-expansion strategies are quantified and best response actions are identified. Capacity-expansion strategies were found to have superadditive benefits when combined. In fact, an acceptable service level could be achieved by implementing only 2 to 3 of the 9 studied enhancement strategies. (Disaster Med Public Health Preparedness. 2018;page 1 of 13).

Hormonal Regulation of Response to Oxidative Stress in Insects—An Update

PubMed Central

Kodrík, Dalibor; Bednářová, Andrea; Zemanová, Milada; Krishnan, Natraj

2015-01-01

Insects, like other organisms, must deal with a wide variety of potentially challenging environmental factors during the course of their life. An important example of such a challenge is the phenomenon of oxidative stress. This review summarizes the current knowledge on the role of adipokinetic hormones (AKH) as principal stress responsive hormones in insects involved in activation of anti-oxidative stress response pathways. Emphasis is placed on an analysis of oxidative stress experimentally induced by various stressors and monitored by suitable biomarkers, and on detailed characterization of AKH’s role in the anti-stress reactions. These reactions are characterized by a significant increase of AKH levels in the insect body, and by effective reversal of the markers—disturbed by the stressors—after co-application of the stressor with AKH. A plausible mechanism of AKH action in the anti-oxidative stress response is discussed as well: this probably involves simultaneous employment of both protein kinase C and cyclic adenosine 3′,5′-monophosphate pathways in the presence of extra and intra-cellular Ca2+ stores, with the possible involvement of the FoxO transcription factors. The role of other insect hormones in the anti-oxidative defense reactions is also discussed. PMID:26516847

Parietal blood oxygenation level-dependent response evoked by covert visual search reflects set-size effect in monkeys.

PubMed

Atabaki, A; Marciniak, K; Dicke, P W; Karnath, H-O; Thier, P

2014-03-01

Distinguishing a target from distractors during visual search is crucial for goal-directed behaviour. The more distractors that are presented with the target, the larger is the subject's error rate. This observation defines the set-size effect in visual search. Neurons in areas related to attention and eye movements, like the lateral intraparietal area (LIP) and frontal eye field (FEF), diminish their firing rates when the number of distractors increases, in line with the behavioural set-size effect. Furthermore, human imaging studies that have tried to delineate cortical areas modulating their blood oxygenation level-dependent (BOLD) response with set size have yielded contradictory results. In order to test whether BOLD imaging of the rhesus monkey cortex yields results consistent with the electrophysiological findings and, moreover, to clarify if additional other cortical regions beyond the two hitherto implicated are involved in this process, we studied monkeys while performing a covert visual search task. When varying the number of distractors in the search task, we observed a monotonic increase in error rates when search time was kept constant as was expected if monkeys resorted to a serial search strategy. Visual search consistently evoked robust BOLD activity in the monkey FEF and a region in the intraparietal sulcus in its lateral and middle part, probably involving area LIP. Whereas the BOLD response in the FEF did not depend on set size, the LIP signal increased in parallel with set size. These results demonstrate the virtue of BOLD imaging in monkeys when trying to delineate cortical areas underlying a cognitive process like visual search. However, they also demonstrate the caution needed when inferring neural activity from BOLD activity. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Genetic Effects of Uv Irradiation on Excision-Proficient and -Deficient Yeast during Meiosis

PubMed Central

Resnick, Michael A.; Game, John C.; Stasiewicz, Stanley

1983-01-01

The lethal and recombinational responses to ultraviolet light irradiation (UV) by excision-proficient (RAD+) and deficient strains (rad1) of Saccharomyces cerevisiae has been examined in cells undergoing meiosis. Cells that exhibit high levels of meiotic synchrony were irradiated either at the beginning or at various times during meiosis and allowed to proceed through meiosis. Based on survival responses, the only excision repair mechanism for UV damage available during meiosis is that controlled by the RAD1 pathway. The presence of pyrimidine dimers at the beginning of meiosis does not prevent cells from undergoing meiosis; however, the spore products exhibit much lower survival than cells from earlier stages of meiosis. The reduced survival is probably due to effects of UV on recombination. Meiotic levels of gene conversion are reduced only two to three times in these experiments; however, intergenic recombination is nearly abolished after a dose of 4 J/m 2 to the rad1 strain. Exposure to 25 J/m2 had little effect on the wild-type strain. Since normal meiotic reciprocal recombination is generally considered to involve gene conversion-type intermediates, it appears that unrepaired UV damage dissociates the two processes. These results complement those obtained with the mei-9 mutants of Drosophila which also demonstrate a dissociation between gene conversion and reciprocal recombination. These results are consistent with molecular observations on the UV-irradiated rad1 strain in that there is no excision of pyrimidine dimers or exchange of dimers during meiosis. PMID:6352405

Effects of heavy metals on benthic macroinvertebrate communities in New Zealand streams

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

Hickey, C.W.; Clements, W.H.

1998-11-01

The authors performed chemical analyses of heavy metals in water and periphyton, toxicity tests with Daphnia magna and an indigenous mayfly (Deleatidium sp.), and field surveys of benthic macroinvertebrates to estimate the degree of metal pollution in three catchments in the Coromandel Peninsula of New Zealand. Good agreement was found between toxicity tests and measures of benthic community structure, particularly at stations with the highest metal levels. Responses of benthic communities at stations with low or moderate levels of metal contamination were variable and were probably confounded by factors other than heavy metals. Effects of heavy metals on benthic communitiesmore » in New Zealand streams were similar to those reported for metal-polluted streams in North America and Europe, suggesting that responses to metal contamination are predictable. Abundance and species richness of mayflies, number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera, and total taxonomic richness were the best indicators of heavy metals in New Zealand streams. In contrast, the quantitative macroinvertebrate community index (QMCI), a biotic index proposed for assessing effects of organic enrichment in New Zealand streams, could not distinguish between reference and metal-polluted streams. The poor performance of the QMCI was primarily due to incorrect tolerance scores for some taxa to heavy metals. Because of concerns regarding the subjective assignment of tolerance values to species, the authors recommend that tolerance values for dominant species in New Zealand streams should be verified experimentally in stream microcosms.« less

Comparison of Aperture Averaging and Receiver Diversity Techniques for Free Space Optical Links in Presence of Turbulence and Various Weather Conditions

NASA Astrophysics Data System (ADS)

Kaur, Prabhmandeep; Jain, Virander Kumar; Kar, Subrat

2014-12-01

In this paper, we investigate the performance of a Free Space Optic (FSO) link considering the impairments caused by the presence of various weather conditions such as very clear air, drizzle, haze, fog, etc., and turbulence in the atmosphere. Analytic expression for the outage probability is derived using the gamma-gamma distribution for turbulence and accounting the effect of weather conditions using the Beer-Lambert's law. The effect of receiver diversity schemes using aperture averaging and array receivers on the outage probability is studied and compared. As the aperture diameter is increased, the outage probability decreases irrespective of the turbulence strength (weak, moderate and strong) and weather conditions. Similar effects are observed when the number of direct detection receivers in the array are increased. However, it is seen that as the desired level of performance in terms of the outage probability decreases, array receiver becomes the preferred choice as compared to the receiver with aperture averaging.

Effect of strenuous physical exercise on circulating cell-derived microparticles.

PubMed

Chaar, Vicky; Romana, Marc; Tripette, Julien; Broquere, Cédric; Huisse, Marie-Geneviève; Hue, Olivier; Hardy-Dessources, Marie-Dominique; Connes, Philippe

2011-01-01

Strenuous exercise is associated with an inflammatory response involving the activation of several types of blood cells. In order to document the specific activation of these cell types, we studied the effect of three maximal exercise tests conducted to exhaustion on the quantitative and qualitative pattern of circulating cell-derived microparticles and inflammatory molecules in healthy subjects. This study mainly indicated that the plasma concentration of microparticles from platelets and polymorphonuclear neutrophils (PMN) was increased immediately after the strenuous exercise. In addition, the increase in plasma concentration of microparticles from PMN and platelets was still observed after 2 hours of recovery. A similar pattern was observed for the IL-6 plasma level. In contrast, no change was observed for either soluble selectins or plasma concentration of microparticles from red blood cells, monocytes and endothelial cells. In agreement, sVCAM-1 and sICAM-1 levels were not changed by the exercise. We conclude that a strenuous exercise is accompanied by platelet- and PMN-derived microparticle production that probably reflects the activation of these two cell types.

Fear of progression.

PubMed

Herschbach, Peter; Dinkel, Andreas

2014-01-01

Fear of progression (or fear of recurrence) is an appropriate, rational response to the real threat of cancer and cancer treatments. However, elevated levels of fear of progression can become dysfunctional, affecting well-being, quality of life, and social functioning. Research has shown that fear of progression is one of the most frequent distress symptoms of patients with cancer and with other chronic diseases. As a clear consensus concerning clinically relevant states of fear of progression is currently lacking, it is difficult to provide a valid estimate of the rate of cancer patients who clearly suffer from fear of progression. However, recent systematic reviews suggest that probably 50 % of cancer patients experience moderate to severe fear of progression. Furthermore, many patients express unmet needs in dealing with the fear of cancer spreading. These results underline the necessity to provide effective psychological treatments for clinical levels of fear of progression. A few psychosocial interventions for treating fear of progression have been developed so far. Our own, targeted intervention study showed that dysfunctional fear of progression can be effectively treated with a brief group therapy.

First Job Search of Residents in the United States: A Survey of Anesthesiology Trainees' Interest in Academic Positions in Cities Distant from Previous Residences.

PubMed

Dexter, Franklin; De Oliveira, Gildasio S; McCarthy, Robert J

2016-01-15

We surveyed anesthesiology residents to evaluate the predictive effect of prior residence on desired location for future practice opportunities. One thousand five hundred United States anesthesiology residents were invited to participate. One question asked whether they intend to enter academic practice when they graduate from their residency/fellowship training. The analysis categorized the responses into "surely yes" and "probably" versus "even," "probably not," and "surely no." "After finishing your residency/fellowship training, are you planning to look seriously (e.g., interview) at jobs located more than a 2-hour drive from a location where you or your family (e.g., spouse or partner/significant other) have lived previously?" Responses were categorized into "very probably" and "somewhat probably" versus "somewhat improbably" and "not probable." Other questions explored predictors of the relationships quantified using the area under the receiver operating characteristic curve (area under the curve) ± its standard error. Among the 696 respondents, 36.9% (N = 256) would "probably" consider an academic practice. Fewer than half of those (P < 0.0001) would "very probably" consider a distant location (31.6%, 99% CI 24.4%-39.6%). Respondents with prior formal research training (e.g., PhD or Master's) had greater interest in academic practice at a distant location (AUC 0.63 ± 0.03, P = 0.0002). Except among respondents with formal research training, a good question to ask a job applicant is whether the applicant or the applicant's family has previously lived in the area.

Antifatigue Effect of Luteolin-6-C-Neohesperidoside on Oxidative Stress Injury Induced by Forced Swimming of Rats through Modulation of Nrf2/ARE Signaling Pathways.

PubMed

Duan, Fang-Fang; Guo, Ying; Li, Jing-Wan; Yuan, Ke

2017-01-01

Luteolin-6-C-neohesperidoside (LN) is a flavonoid isolated from moso bamboo leaf. This study was performed to evaluate the antifatigue effect of LN on a rat model undergoing the weight-loaded forced swimming test (FST). Briefly, male Sprague-Dawley rats (20-22 weeks old) were forced to undertake exhaustive swimming every other day for 3 weeks. Each swimming session was followed by the administration of distilled water, LN (25-75 mg/kg), or ascorbic acid (100 mg/kg) 1 h later. Oral administration of LN significantly improved exercise endurance; normalized alterations in energy metabolic markers; and decreased serum lactic acid, lactate dehydrogenase, and blood urea nitrogen levels of rats that underwent FST. Moreover, LN enhanced the activities of antioxidant enzymes and antioxidant capacity, as measured by enzyme activity assays, RT-PCR, and Western blotting, as well as decreasing the levels of proinflammatory cytokines such as tumor necrosis factor- α , interleukin-1 β (IL-1 β ), and IL-6 and increasing the level of anti-inflammatory (IL-10) in the liver and skeletal muscle. These results suggested that LN reduces both physical and mental effects of chronic fatigue, probably by attenuating oxidative stress injury and inflammatory responses in the liver and skeletal muscle. This study thus supports the use of LN in functional foods for antifatigue and antioxidant effects.

Markers predicting response to bacillus Calmette-Guérin immunotherapy in high-risk bladder cancer patients: a systematic review.

PubMed

Zuiverloon, Tahlita C M; Nieuweboer, Annemieke J M; Vékony, Hedvig; Kirkels, Wim J; Bangma, Chris H; Zwarthoff, Ellen C

2012-01-01

Currently, bacillus Calmette-Guérin (BCG) intravesical instillations are standard treatment for patients with high-grade non-muscle-invasive bladder cancer; however, no markers are available to predict BCG response. To review the contemporary literature on markers predicting BCG response, to discuss the key issues concerning the identification of predictive markers, and to provide recommendations for further research studies. We performed a systematic review of the literature using PubMed and Embase databases in the period 1996-2010. The free-text search was extended by adding the following keywords: recurrence, progression, survival, molecular marker, prognosis, TP53, Ki-67, RB, fibronectin, immunotherapy, cytokine, interleukin, natural killer, macrophage, PMN, polymorphism, SNP, single nucleotide polymorphism, and gene signature. If thresholds for the detection of urinary interleukin (IL)-8, IL-18, and tumour necrosis factor apoptosis-inducing ligand levels are standardised, measurement of these cytokines holds promise in the assessment of BCG therapy outcome. Studies on immunohistochemical markers (ie, TP53, Ki-67, and retinoblastoma) display contradictory results, probably because of the small patient groups that were used and seem unsuitable to predict BCG response. Exploring combinations of protein levels might prove to be more helpful to establish the effect of BCG therapy. Single nucleotide polymorphisms, either in cytokines or in genes involved in DNA repair, need to be investigated in different ethnicities before their clinical relevance can be determined. Measurement of urinary IL-2 levels seems to be the most potent marker of all the clinical parameters reviewed. IL-2 levels are currently the most promising predictive markers of BCG response. For future studies focusing on new biomarkers, it is essential to make more use of new biomedical techniques such as microRNA profiling and genomewide sequencing. Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Community violence, children's development, and mass media: in pursuit of new insights, new goals, and new strategies.

PubMed

Friedlander, B Z

1993-02-01

Community violence that victimizes children is an unmitigated evil that is exacerbated by vast economic and social forces that leave people in central cities and the rural countryside adrift on seas of rolelessness, hopelessness, group disintegration, and alienation. The contemporary drug scene and the easy availability of guns greatly intensify violence on a local scale, while crimes of violence, especially with guns, appear to be level or declining in the nation as a whole. Claims that the persistently high levels of violence in mass media, mostly television, are largely responsible for violence in society represent narrow views of very large issues. These narrow views overlook essential elements of both phenomena--violence and media. Direct models of interpersonal violence in families and in the community probably give rise to more violent behavior than indirect models in media. Disinhibitory and provocative aspects of media probably do as much or more to trigger violent behavior than violent narratives and violent actions. Comprehensive meta-analysis indicates that prosocial messages on television can have greater effects on behavior than antisocial messages. These data support the contention that mass media can play a strong and positive role in alleviating some of the distress of victims of community violence, and in redirecting the behavior of some of its perpetrators so as to protect the children.

Antarctic glacial history from numerical models and continental margin sediments

USGS Publications Warehouse

Barker, P.F.; Barrett, P.J.; Cooper, A. K.; Huybrechts, P.

1999-01-01

The climate record of glacially transported sediments in prograded wedges around the Antarctic outer continental shelf, and their derivatives in continental rise drifts, may be combined to produce an Antarctic ice sheet history, using numerical models of ice sheet response to temperature and sea-level change. Examination of published models suggests several preliminary conclusions about ice sheet history. The ice sheet's present high sensitivity to sea-level change at short (orbital) periods was developed gradually as its size increased, replacing a declining sensitivity to temperature. Models suggest that the ice sheet grew abruptly to 40% (or possibly more) of its present size at the Eocene-Oligocene boundary, mainly as a result of its own temperature sensitivity. A large but more gradual middle Miocene change was externally driven, probably by development of the Antarctic Circumpolar Current (ACC) and Polar Front, provided that a few million years' delay can be explained. The Oligocene ice sheet varied considerably in size and areal extent, but the late Miocene ice sheet was more stable, though significantly warmer than today's. This difference probably relates to the confining effect of the Antarctic continental margin. Present-day numerical models of ice sheet development are sufficient to guide current sampling plans, but sea-ice formation, polar wander, basal topography and ice streaming can be identified as factors meriting additional modelling effort in the future.

Masked polycythaemia vera: presenting features, response to treatment and clinical outcomes.

PubMed

Alvarez-Larrán, Alberto; Angona, Anna; Ancochea, Agueda; García-Pallarols, Francesc; Fernández, Concepción; Longarón, Raquel; Bellosillo, Beatriz; Besses, Carlos

2016-01-01

Masked polycythaemia vera (PV) has been proposed as a new entity with poorer outcome than overt PV. In this study, the initial clinical and laboratory characteristics, response to treatment and outcome of masked and overt PV were compared using red cell mass and haemoglobin or haematocrit levels for the distinction between both entities. Sixty-eight of 151 PV patients (45%) were classified as masked PV according to World Health Organisation diagnostic criteria, whereas 16 (11%) were classified as masked PV using the British Committee for Standards in Haematology (BCSH). In comparison with overt PV, a higher platelet count and a lower JAK2V617F allele burden at diagnosis were observed in masked PV. Patients with masked PV needed lower phlebotomies and responded faster to hydroxcarbamide than those with overt PV. Complete haematological response was more frequently achieved in masked than in overt PV (79% vs. 58%, P = 0.001). There were no significant differences in the duration of haematological response, the rate of resistance or intolerance to hydroxycarbamide and the probability of molecular response according to type of PV (masked vs. overt). Overall survival, rate of thrombosis and major bleeding, and probability of transformation was superimposable among patients with masked and overt PV. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A stochastic model for the probability of malaria extinction by mass drug administration.

PubMed

Pemberton-Ross, Peter; Chitnis, Nakul; Pothin, Emilie; Smith, Thomas A

2017-09-18

Mass drug administration (MDA) has been proposed as an intervention to achieve local extinction of malaria. Although its effect on the reproduction number is short lived, extinction may subsequently occur in a small population due to stochastic fluctuations. This paper examines how the probability of stochastic extinction depends on population size, MDA coverage and the reproduction number under control, R c . A simple compartmental model is developed which is used to compute the probability of extinction using probability generating functions. The expected time to extinction in small populations after MDA for various scenarios in this model is calculated analytically. The results indicate that mass drug administration (Firstly, R c must be sustained at R c  < 1.2 to avoid the rapid re-establishment of infections in the population. Secondly, the MDA must produce effective cure rates of >95% to have a non-negligible probability of successful elimination. Stochastic fluctuations only significantly affect the probability of extinction in populations of about 1000 individuals or less. The expected time to extinction via stochastic fluctuation is less than 10 years only in populations less than about 150 individuals. Clustering of secondary infections and of MDA distribution both contribute positively to the potential probability of success, indicating that MDA would most effectively be administered at the household level. There are very limited circumstances in which MDA will lead to local malaria elimination with a substantial probability.

The reliability of continuous brain responses during naturalistic listening to music.

PubMed

Burunat, Iballa; Toiviainen, Petri; Alluri, Vinoo; Bogert, Brigitte; Ristaniemi, Tapani; Sams, Mikko; Brattico, Elvira

2016-01-01

Low-level (timbral) and high-level (tonal and rhythmical) musical features during continuous listening to music, studied by functional magnetic resonance imaging (fMRI), have been shown to elicit large-scale responses in cognitive, motor, and limbic brain networks. Using a similar methodological approach and a similar group of participants, we aimed to study the replicability of previous findings. Participants' fMRI responses during continuous listening of a tango Nuevo piece were correlated voxelwise against the time series of a set of perceptually validated musical features computationally extracted from the music. The replicability of previous results and the present study was assessed by two approaches: (a) correlating the respective activation maps, and (b) computing the overlap of active voxels between datasets at variable levels of ranked significance. Activity elicited by timbral features was better replicable than activity elicited by tonal and rhythmical ones. These results indicate more reliable processing mechanisms for low-level musical features as compared to more high-level features. The processing of such high-level features is probably more sensitive to the state and traits of the listeners, as well as of their background in music. Copyright © 2015 Elsevier Inc. All rights reserved.

Background of the Hammett equation as observed for isolated molecules: meta- and para-substituted benzoic acids.

PubMed

Exner, Otto; Böhm, Stanislav

2002-09-06

Fundamental model compounds for the Hammett equation, meta- and para-substituted benzoic acids, were investigated by the density functional theory at the B3LYP/6-311+G(d,p) level. Energies of 25 acids and of their anions were calculated in all possible conformations and from them the energies of the assumed mixture of conformers. Relative acidities correlated with the experimental gas-phase acidities almost within the experimental uncertainty, much more precisely than in the case of previous calculations at lower levels. Dissection of the substituent effects into those operating in the acid molecule and in the anion was carried out by means of isodesmic reactions starting from monosubstituted benzenes. Both effects are cooperating in the resulting effect on the acidity; those in the acid molecule are smaller but not negligible. They are also responsible for some deviations from the Hammett equation (through-resonance of para donor substituents) and for the weaker resonance in the acid molecule in meta derivatives; in the anions the inductive and resonance effects are almost equal. On the other hand, the cooperation of effects in the acid and in the anion makes the relative acidity more sensitive to electron withdrawing and is probably one of the reasons why the Hammett equation is so generally valid.

The effect of (+)-lysergic acid diethylamide and other drugs on the carotid sinus reflex

PubMed Central

Ginzel, K. H.

1958-01-01

In cats, lysergic acid diethylamide (LSD) selectively blocked the reflex blood pressure rise following carotid chemoreceptor stimulation. It also reduced or abolished the chemoreceptor component of the pressor response to occlusion of the common carotid arteries. It did not inhibit the respiratory reflexes arising from the carotid chemoreceptors, unless spontaneous respiration was interfered with as a whole. The site of action was central, probably below the intercollicular level, regardless of whether the drug was administered by the intravenous route or into the lateral ventricle of the brain. LSD did not block the baroreceptor depressor reflex elicited by stimulation of one carotid sinus nerve. LSD frequently caused the systemic pressure to fall, even after vagotomy and atropine, and this effect might account for the occasional reduction of the baroreceptor component of the carotid occlusion response. On the other hand, no relationship was found between the action of LSD on vasomotor tone and its blocking effect on the chemoreceptor pressor reflex. Some derivatives of LSD produced effects similar to those described for LSD, whether or not they possessed a psychotropic action in man, and independently of their efficiency as antagonists to 5-hydroxytryptamine. Of a series of compounds chemically unrelated to LSD, chlorpromazine was found to block the chemoreceptor pressor rise after intracerebroventricular injection. PMID:13584725

The effect of (+)-lysergic acid diethylamide and other drugs on the carotid sinus reflex.

PubMed

GINZEL, K H

1958-09-01

In cats, lysergic acid diethylamide (LSD) selectively blocked the reflex blood pressure rise following carotid chemoreceptor stimulation. It also reduced or abolished the chemoreceptor component of the pressor response to occlusion of the common carotid arteries. It did not inhibit the respiratory reflexes arising from the carotid chemoreceptors, unless spontaneous respiration was interfered with as a whole. The site of action was central, probably below the intercollicular level, regardless of whether the drug was administered by the intravenous route or into the lateral ventricle of the brain.LSD did not block the baroreceptor depressor reflex elicited by stimulation of one carotid sinus nerve. LSD frequently caused the systemic pressure to fall, even after vagotomy and atropine, and this effect might account for the occasional reduction of the baroreceptor component of the carotid occlusion response. On the other hand, no relationship was found between the action of LSD on vasomotor tone and its blocking effect on the chemoreceptor pressor reflex.Some derivatives of LSD produced effects similar to those described for LSD, whether or not they possessed a psychotropic action in man, and independently of their efficiency as antagonists to 5-hydroxytryptamine. Of a series of compounds chemically unrelated to LSD, chlorpromazine was found to block the chemoreceptor pressor rise after intracerebroventricular injection.

Summary of evidence-based guideline update: Prevention of stroke in nonvalvular atrial fibrillation

PubMed Central

Culebras, Antonio; Messé, Steven R.; Chaturvedi, Seemant; Kase, Carlos S.; Gronseth, Gary

2014-01-01

Objective: To update the 1998 American Academy of Neurology practice parameter on stroke prevention in nonvalvular atrial fibrillation (NVAF). How often do various technologies identify previously undetected NVAF? Which therapies reduce ischemic stroke risk with the least risk of hemorrhage, including intracranial hemorrhage? The complete guideline on which this summary is based is available as an online data supplement to this article. Methods: Systematic literature review; modified Delphi process recommendation formulation. Major conclusions: In patients with recent cryptogenic stroke, cardiac rhythm monitoring probably detects occult NVAF. In patients with NVAF, dabigatran, rivaroxaban, and apixaban are probably at least as effective as warfarin in preventing stroke and have a lower risk of intracranial hemorrhage. Triflusal plus acenocoumarol is likely more effective than acenocoumarol alone in reducing stroke risk. Clopidogrel plus aspirin is probably less effective than warfarin in preventing stroke and has a lower risk of intracranial bleeding. Clopidogrel plus aspirin as compared with aspirin alone probably reduces stroke risk but increases the risk of major hemorrhage. Apixaban is likely more effective than aspirin for decreasing stroke risk and has a bleeding risk similar to that of aspirin. Major recommendations: Clinicians might obtain outpatient cardiac rhythm studies in patients with cryptogenic stroke to identify patients with occult NVAF (Level C) and should routinely offer anticoagulation to patients with NVAF and a history of TIA/stroke (Level B). Specific patient considerations will inform anticoagulant selection in patients with NVAF judged to need anticoagulation. PMID:24566225

Disruptive Effects of Contingent Food on High-Probability Behavior

ERIC Educational Resources Information Center

Frank-Crawford, Michelle A.; Borrero, John C.; Nguyen, Linda; Leon-Enriquez, Yanerys; Carreau-Webster, Abbey B.; DeLeon, Iser G.

2012-01-01

The delivery of food contingent on 10 s of consecutive toy engagement resulted in a decrease in engagement and a corresponding increase in other responses that had been previously reinforced with food. Similar effects were not observed when tokens exchangeable for the same food were delivered, suggesting that engagement was disrupted by the…

Brand-specific cigarette advertising in magazines in relation to youth and young adult readership, 1986-1994.

PubMed

King, C; Siegel, M

1999-12-01

This study investigated whether cigarette brands popular among youths are preferentially advertised in magazines with high youth readerships. Using a probit regression model of 1986-1994 data, we estimated the effect of the percentage of youth (ages 12-17) readers in a magazine on the probability of a cigarette brand advertising in that magazine and compared these effects for youth cigarette brands (those smoked by more than 2.5% of 10-15-year-old smokers) and adult cigarette brands. We controlled for the percentages of young adult (ages 18-24), female, black, and Hispanic readers. Holding all other variables constant at their sample means, the probability of an adult brand advertising in a magazine decreased from 0.76 (95% confidence interval [CI], 0.67-0.85) at a youth readership level of 2% (the lowest level of percentage youth readership in the sample magazines) to 0.46 (95% CI, 0.29-0.64) at a youth readership level of 47% (the highest level in the sample magazines). In contrast, the probability of a youth brand advertising in a magazine increased from 0.63 (95% CI, 0.51-0.75) at a youth readership level of 2% to 0.84 (95% CI, 0.72-0.96) at a youth readership level of 47%. It was concluded that, over nearly a decade, cigarette brands popular among youths were more likely than adult brands to advertise in magazines with high youth readerships.

Cannabis use in children with individualized risk profiles: Predicting the effect of universal prevention intervention.

PubMed

Miovský, Michal; Vonkova, Hana; Čablová, Lenka; Gabrhelík, Roman

2015-11-01

To study the effect of a universal prevention intervention targeting cannabis use in individual children with different risk profiles. A school-based randomized controlled prevention trial was conducted over a period of 33 months (n=1874 sixth-graders, baseline mean age 11.82). We used a two-level random intercept logistic model for panel data to predict the probabilities of cannabis use for each child. Specifically, we used eight risk/protective factors to characterize each child and then predicted two probabilities of cannabis use for each child if the child had the intervention or not. Using the two probabilities, we calculated the absolute and relative effect of the intervention for each child. According to the two probabilities, we also divided the sample into a low-risk group (the quarter of the children with the lowest probabilities), a moderate-risk group, and a high-risk group (the quarter of the children with the highest probabilities) and showed the average effect of the intervention on these groups. The differences between the intervention group and the control group were statistically significant in each risk group. The average predicted probabilities of cannabis use for a child from the low-risk group were 4.3% if the child had the intervention and 6.53% if no intervention was provided. The corresponding probabilities for a child from the moderate-risk group were 10.91% and 15.34% and for a child from the high-risk group 25.51% and 32.61%. School grades, thoughts of hurting oneself, and breaking the rules were the three most important factors distinguishing high-risk and low-risk children. We predicted the effect of the intervention on individual children, characterized by their risk/protective factors. The predicted absolute effect and relative effect of any intervention for any selected risk/protective profile of a given child may be utilized in both prevention practice and research. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cross-stream migration of active particles

NASA Astrophysics Data System (ADS)

Uspal, William; Katuri, Jaideep; Simmchen, Juliane; Miguel-Lopez, Albert; Sanchez, Samuel

For natural microswimmers, the interplay of swimming activity and external flow can promote robust directed motion, e.g. propulsion against (upstream rheotaxis) or perpendicular to the direction of flow. These effects are generally attributed to their complex body shapes and flagellar beat patterns. Here, using catalytic Janus particles as a model system, we report on a strong directional response that naturally emerges for spherical active particles in a channel flow. The particles align their propulsion axis to be perpendicular to both the direction of flow and the normal vector of a nearby bounding surface. We develop a deterministic theoretical model that captures this spontaneous transverse orientational order. We show how the directional response emerges from the interplay of external shear flow and swimmer/surface interactions (e.g., hydrodynamic interactions) that originate in swimming activity. Finally, adding the effect of thermal noise, we obtain probability distributions for the swimmer orientation that show good agreement with the experimental probability distributions. Our findings show that the qualitative response of microswimmers to flow is sensitive to the detailed interaction between individual microswimmers and bounding surfaces.

Effects of acidification on olfactory-mediated behaviour in freshwater and marine ecosystems: a synthesis

PubMed Central

Leduc, Antoine O. H. C.; Munday, Philip L.; Brown, Grant E.; Ferrari, Maud C. O.

2013-01-01

For many aquatic organisms, olfactory-mediated behaviour is essential to the maintenance of numerous fitness-enhancing activities, including foraging, reproduction and predator avoidance. Studies in both freshwater and marine ecosystems have demonstrated significant impacts of anthropogenic acidification on olfactory abilities of fish and macroinvertebrates, leading to impaired behavioural responses, with potentially far-reaching consequences to population dynamics and community structure. Whereas the ecological impacts of impaired olfactory-mediated behaviour may be similar between freshwater and marine ecosystems, the underlying mechanisms are quite distinct. In acidified freshwater, molecular change to chemical cues along with reduced olfaction sensitivity appear to be the primary causes of olfactory-mediated behavioural impairment. By contrast, experiments simulating future ocean acidification suggest that interference of high CO2 with brain neurotransmitter function is the primary cause for olfactory-mediated behavioural impairment in fish. Different physico-chemical characteristics between marine and freshwater systems are probably responsible for these distinct mechanisms of impairment, which, under globally rising CO2 levels, may lead to strikingly different consequences to olfaction. While fluctuations in pH may occur in both freshwater and marine ecosystems, marine habitat will remain alkaline despite future ocean acidification caused by globally rising CO2 levels. In this synthesis, we argue that ecosystem-specific mechanisms affecting olfaction need to be considered for effective management and conservation practices. PMID:23980246

Effects of acidification on olfactory-mediated behaviour in freshwater and marine ecosystems: a synthesis.

PubMed

Leduc, Antoine O H C; Munday, Philip L; Brown, Grant E; Ferrari, Maud C O

2013-01-01

For many aquatic organisms, olfactory-mediated behaviour is essential to the maintenance of numerous fitness-enhancing activities, including foraging, reproduction and predator avoidance. Studies in both freshwater and marine ecosystems have demonstrated significant impacts of anthropogenic acidification on olfactory abilities of fish and macroinvertebrates, leading to impaired behavioural responses, with potentially far-reaching consequences to population dynamics and community structure. Whereas the ecological impacts of impaired olfactory-mediated behaviour may be similar between freshwater and marine ecosystems, the underlying mechanisms are quite distinct. In acidified freshwater, molecular change to chemical cues along with reduced olfaction sensitivity appear to be the primary causes of olfactory-mediated behavioural impairment. By contrast, experiments simulating future ocean acidification suggest that interference of high CO2 with brain neurotransmitter function is the primary cause for olfactory-mediated behavioural impairment in fish. Different physico-chemical characteristics between marine and freshwater systems are probably responsible for these distinct mechanisms of impairment, which, under globally rising CO2 levels, may lead to strikingly different consequences to olfaction. While fluctuations in pH may occur in both freshwater and marine ecosystems, marine habitat will remain alkaline despite future ocean acidification caused by globally rising CO2 levels. In this synthesis, we argue that ecosystem-specific mechanisms affecting olfaction need to be considered for effective management and conservation practices.

Comprehensive Analysis of ABA Effects on Ethylene Biosynthesis and Signaling during Tomato Fruit Ripening.

PubMed

Mou, Wangshu; Li, Dongdong; Bu, Jianwen; Jiang, Yuanyuan; Khan, Zia Ullah; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

2016-01-01

ABA has been widely acknowledged to regulate ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism underlying the interaction between these two hormones are largely unexplored. In the present study, exogenous ABA treatment obviously promoted fruit ripening as well as ethylene emission, whereas NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis) application showed the opposite biological effects. Combined RNA-seq with time-course RT-PCR analysis, our study not only helped to illustrate how ABA regulated itself at the transcription level, but also revealed that ABA can facilitate ethylene production and response probably by regulating some crucial genes such as LeACS4, LeACO1, GR and LeETR6. In addition, investigation on the fruits treated with 1-MCP immediately after ABA exposure revealed that ethylene might be essential for the induction of ABA biosynthesis and signaling at the onset of fruit ripening. Furthermore, some specific transcription factors (TFs) known as regulators of ethylene synthesis and sensibility (e.g. MADS-RIN, TAGL1, CNR and NOR) were also observed to be ABA responsive, which implied that ABA influenced ethylene action possibly through the regulation of these TFs expression. Our comprehensive physiological and molecular-level analysis shed light on the mechanism of cross-talk between ABA and ethylene during the process of tomato fruit ripening.

Comprehensive Analysis of ABA Effects on Ethylene Biosynthesis and Signaling during Tomato Fruit Ripening

PubMed Central

Bu, Jianwen; Jiang, Yuanyuan; Khan, Zia Ullah; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

2016-01-01

ABA has been widely acknowledged to regulate ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism underlying the interaction between these two hormones are largely unexplored. In the present study, exogenous ABA treatment obviously promoted fruit ripening as well as ethylene emission, whereas NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis) application showed the opposite biological effects. Combined RNA-seq with time-course RT-PCR analysis, our study not only helped to illustrate how ABA regulated itself at the transcription level, but also revealed that ABA can facilitate ethylene production and response probably by regulating some crucial genes such as LeACS4, LeACO1, GR and LeETR6. In addition, investigation on the fruits treated with 1-MCP immediately after ABA exposure revealed that ethylene might be essential for the induction of ABA biosynthesis and signaling at the onset of fruit ripening. Furthermore, some specific transcription factors (TFs) known as regulators of ethylene synthesis and sensibility (e.g. MADS-RIN, TAGL1, CNR and NOR) were also observed to be ABA responsive, which implied that ABA influenced ethylene action possibly through the regulation of these TFs expression. Our comprehensive physiological and molecular-level analysis shed light on the mechanism of cross-talk between ABA and ethylene during the process of tomato fruit ripening. PMID:27100326

Preliminary efficacy of prize-based contingency management to increase activity levels in healthy adults.

PubMed

Washington, Wendy Donlin; Banna, Kelly M; Gibson, Amanda L

2014-01-01

An estimated 30% of Americans meet the criteria for obesity. Effective, low-cost interventions to increase physical activity are needed to prevent and treat obesity. In this study, 11 healthy adults wore Fitbit accelerometers for 3 weeks. During the initial baseline, subjects earned prize draws for wearing the Fitbit. During intervention, percentile schedules were used to calculate individual prize-draw criteria. The final week was a return to baseline. Four subjects increased step counts as a result of the intervention. A bout analysis of interresponse times revealed that subjects increased overall step counts by increasing daily minutes active and within-bout response rates and decreasing pauses between bouts of activity. Strategies to improve effectiveness are suggested, such as modification of reinforcement probability and amount and identification of the function of periods of inactivity. © Society for the Experimental Analysis of Behavior.

Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence

NASA Technical Reports Server (NTRS)

Nickerson, C. A.; Ott, C. M.; Mister, S. J.; Morrow, B. J.; Burns-Keliher, L.; Pierson, D. L.

2000-01-01

The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence.

The effect of quercetin dietary supplementation on meat oxidation processes and texture of fattening lambs.

PubMed

Andrés, S; Huerga, L; Mateo, J; Tejido, M L; Bodas, R; Morán, L; Prieto, N; Rotolo, L; Giráldez, F J

2014-02-01

Thirty two lambs were fed a total mixed ration (TMR) formulated either with palm oil (CTRL; 34 g palm oil kg(-1) TMR) or whole flaxseed (+FS, 85 g flaxseed kg(-1) TMR) alone or enriched with quercetin (+QCT, 34 g palm oil plus 2 g quercetin kg(-1) TMR; +FS+QCT, 85 g flaxseed plus 2 g quercetin kg(-1) TMR). Dietary flaxseed did not affect, in a significant manner, the lipid peroxidation of meat samples. Quercetin treatment reduced oxysterol content (P<0.05) after 7 days of refrigerated storage of fresh meat, but did not affect significantly (P>0.05) the level of lipid-derived volatiles in the headspace of the light-exposed stored cooked meat. Sensory evaluation showed flaxseed as being responsible for a negative effect on meat flavour, probably associated with a modification of the fatty acid profile whereas, unexpectedly, quercetin seemed to worsen meat tenderisation. © 2013.

Testing metapopulation concepts: effects of patch characteristics and neighborhood occupancy on the dynamics of an endangered lagomorph

USGS Publications Warehouse

Eaton, Mitchell J.; Hughes, Phillip T.; Hines, James E.; Nichols, James D.

2014-01-01

Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model selection to identify important drivers of population turnover and estimate the effective neighborhood size for this system. Several key relationships related to patch size and isolation that are often assumed in metapopulation models were supported: patch size was negatively related to the probability of extinction and positively related to colonization, and estimated occupancy of neighboring patches was positively related to colonization and negatively related to extinction probabilities. This latter relationship suggested the existence of rescue effects. In our study system, we inferred that coastal patches experienced higher probabilities of extinction and colonization than interior patches. Interior patches exhibited higher occupancy probabilities and may serve as refugia, permitting colonization of coastal patches following disturbances such as hurricanes and storm surges. Our modeling approach should be useful for incorporating neighbor occupancy into future metapopulation analyses and in dealing with other historic occupancy surveys that may not include the recommended levels of sampling replication.