Experimental Contact Lens to Prevent Glaucoma-Induced Blindness

Science.gov (United States)

... An Experimental Contact Lens to Prevent Glaucoma-Induced Blindness By Sharon Reynolds Posted January 23, 2014 An ... group of conditions that can result in irreversible blindness. This vision loss can be reduced if glaucoma ...

Imaging the neural effects of cognitive bias modification training

NARCIS (Netherlands)

Wiers, C.E.; Wiers, R.W.

Cognitive bias modification (CBM) was first developed as an experimental tool to examine the causal role of cognitive biases, and later developed into complementary interventions in experimental psychopathology research. CBM involves the "re-training" of implicit biases by means of multiple trials

Plant Disease Severity Assessment-How Rater Bias, Assessment Method, and Experimental Design Affect Hypothesis Testing and Resource Use Efficiency.

Science.gov (United States)

Chiang, Kuo-Szu; Bock, Clive H; Lee, I-Hsuan; El Jarroudi, Moussa; Delfosse, Philippe

2016-12-01

The effect of rater bias and assessment method on hypothesis testing was studied for representative experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed "balanced" and those with unequal numbers of replicate estimates are termed "unbalanced". The three assessment methods considered were nearest percent estimates (NPEs), an amended 10% incremental scale, and the Horsfall-Barratt (H-B) scale. Estimates of severity of Septoria leaf blotch on leaves of winter wheat were used to develop distributions for a simulation model. The experimental designs are presented here in the context of simulation experiments which consider the optimal design for the number of specimens (individual units sampled) and the number of replicate estimates per specimen for a fixed total number of observations (total sample size for the treatments being compared). The criterion used to gauge each method was the power of the hypothesis test. As expected, at a given fixed number of observations, the balanced experimental designs invariably resulted in a higher power compared with the unbalanced designs at different disease severity means, mean differences, and variances. Based on these results, with unbiased estimates using NPE, the recommended number of replicate estimates taken per specimen is 2 (from a sample of specimens of at least 30), because this conserves resources. Furthermore, for biased estimates, an apparent difference in the power of the hypothesis test was observed between assessment methods and between experimental designs. Results indicated that, regardless of experimental design or rater bias, an amended 10% incremental scale has slightly less power compared with NPEs, and that the H-B scale is more likely than the others to cause a type II error. These results suggest that choice of assessment method, optimizing sample number and number of replicate

Heuristics and biases in cardiovascular disease prevention: How can we improve communication about risk, benefits and harms?

Science.gov (United States)

Bonner, Carissa; McKinn, Shannon; Lau, Annie; Jansen, Jesse; Doust, Jenny; Trevena, Lyndal; McCaffery, Kirsten

2018-05-01

Cardiovascular disease (CVD) prevention guidelines recommend medication based on the probability of a heart attack/stroke in the next 5-10 years. However, heuristics and biases make risk communication challenging for doctors. This study explored how patients interpret personalised CVD risk results presented in varying formats and timeframes. GPs recruited 25 patients with CVD risk factors and varying medication history. Participants were asked to 'think aloud' while using two CVD risk calculators that present probabilistic risk in different ways, within a semi-structured interview. Transcribed audio-recordings were coded using Framework Analysis. Key themes were: 1) numbers lack meaning without a reference point; 2) risk results need to be both credible and novel; 3) selective attention to intervention effects. Risk categories (low/moderate/high) provided meaningful context, but short-term risk results were not credible if they didn't match expectations. Colour-coded icon arrays showing the effect of age and interventions were seen as novel and motivating. Those on medication focused on benefits, while others focused on harms. CVD risk formats need to be tailored to patient expectations and experiences in order to counteract heuristics and biases. Doctors need access to multiple CVD risk formats to communicate effectively about CVD prevention. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of 3000 m Subsea Blowout Preventer Experimental Prototype

Science.gov (United States)

Cai, Baoping; Liu, Yonghong; Huang, Zhiqian; Ma, Yunpeng; Zhao, Yubin

2017-12-01

A subsea blowout preventer experimental prototype is developed to meet the requirement of training operators, and the prototype consists of hydraulic control system, electronic control system and small-sized blowout preventer stack. Both the hydraulic control system and the electronic system are dual-mode redundant systems. Each system works independently and is switchable when there are any malfunctions. And it significantly improves the operation reliability of the equipment.

Theory-Led Confirmation Bias and Experimental Persona

Science.gov (United States)

Allen, Michael

2011-01-01

Questionnaire and interview findings from a survey of three Year 8 (ages 12-13 years) science practical lessons (n = 52) demonstrate how pupils' data collection and inference making were sometimes biased by desires to confirm a personal theory. A variety of behaviours are described where learners knowingly rejected anomalies, manipulated…

Prevention of hepatocellular carcinoma: potential targets, experimental models, and clinical challenges

Science.gov (United States)

Hoshida, Yujin; Fuchs, Bryan C.; Tanabe, Kenneth K.

2013-01-01

Chronic fibrotic liver diseases such as viral hepatitis eventually develop liver cirrhosis, which causes occurrence of hepatocellular carcinoma (HCC). Given the limited therapeutic efficacy in advanced HCC, prevention of HCC development could be an effective strategy for improving patient prognosis. However, there is still no established therapy to meet the goal. Studies have elucidated a wide variety of molecular mechanisms and signaling pathways involved in HCC development. Genetically-engineered or chemically-treated experimental models of cirrhosis and HCC have been developed and shown their potential value in investigating molecular therapeutic targets and diagnostic biomarkers for HCC prevention. In this review, we overview potential targets of prevention and currently available experimental models, and discuss strategies to translate the findings into clinical practice. PMID:22873223

Attention bias modification training under working memory load increases the magnitude of change in attentional bias.

Science.gov (United States)

Clarke, Patrick J F; Branson, Sonya; Chen, Nigel T M; Van Bockstaele, Bram; Salemink, Elske; MacLeod, Colin; Notebaert, Lies

2017-12-01

Attention bias modification (ABM) procedures have shown promise as a therapeutic intervention, however current ABM procedures have proven inconsistent in their ability to reliably achieve the requisite change in attentional bias needed to produce emotional benefits. This highlights the need to better understand the precise task conditions that facilitate the intended change in attention bias in order to realise the therapeutic potential of ABM procedures. Based on the observation that change in attentional bias occurs largely outside conscious awareness, the aim of the current study was to determine if an ABM procedure delivered under conditions likely to preclude explicit awareness of the experimental contingency, via the addition of a working memory load, would contribute to greater change in attentional bias. Bias change was assessed among 122 participants in response to one of four ABM tasks given by the two experimental factors of ABM training procedure delivered either with or without working memory load, and training direction of either attend-negative or avoid-negative. Findings revealed that avoid-negative ABM procedure under working memory load resulted in significantly greater reductions in attentional bias compared to the equivalent no-load condition. The current findings will require replication with clinical samples to determine the utility of the current task for achieving emotional benefits. These present findings are consistent with the position that the addition of a working memory load may facilitate change in attentional bias in response to an ABM training procedure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mood-congruent attention and memory bias in dysphoria: Exploring the coherence among information-processing biases.

Science.gov (United States)

Koster, Ernst H W; De Raedt, Rudi; Leyman, Lemke; De Lissnyder, Evi

2010-03-01

Recent studies indicate that depression is characterized by mood-congruent attention bias at later stages of information-processing. Moreover, depression has been associated with enhanced recall of negative information. The present study tested the coherence between attention and memory bias in dysphoria. Stable dysphoric (n = 41) and non-dysphoric (n = 41) undergraduates first performed a spatial cueing task that included negative, positive, and neutral words. Words were presented for 250 ms under conditions that allowed or prevented elaborate processing. Memory for the words presented in the cueing task was tested using incidental free recall. Dysphoric individuals exhibited an attention bias for negative words in the condition that allowed elaborate processing, with the attention bias for negative words predicting free recall of negative words. Results demonstrate the coherence of attention and memory bias in dysphoric individuals and provide suggestions on the influence of attention bias on further processing of negative material. 2009 Elsevier Ltd. All rights reserved.

Transmission of Cognitive Bias and Fear From Parents to Children: An Experimental Study.

Science.gov (United States)

Remmerswaal, Danielle; Muris, Peter; Huijding, Jorg

2016-01-01

This study explored the role of parents in the development of a cognitive bias and subsequent fear levels in children. In Experiment 1, nonclinical children ages 8-13 (N = 122) underwent a training during which they worked together with their mothers on an information search task. Mothers received instructions to induce either a positive or negative information search bias in their children. Experiment 2 investigated to what extent mothers own cognitive bias predicted children's information search bias. Mothers of 49 nonclinical children ages 9-12 received no explicit training instructions before working together with their child on an information search task. Experiment 1 demonstrated that mothers had a significant impact on children's cognitive bias and fear. More precisely, children who had received a negative parental training displayed an increase in negative information search bias and fear, whereas children who had received a positive parental training showed an increase in positive information search bias and a decrease in fear. In Experiment 2, it was found that children's information search biases after working together with their mothers were predicted by their mothers' initial cognitive bias scores. These findings can be taken as support for the intergenerational transmission of cognitive biases from mothers to children.

Using Machine Learning to Predict MCNP Bias

Energy Technology Data Exchange (ETDEWEB)

Grechanuk, Pavel Aleksandrovi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-01-09

For many real-world applications in radiation transport where simulations are compared to experimental measurements, like in nuclear criticality safety, the bias (simulated - experimental k_eff) in the calculation is an extremely important quantity used for code validation. The objective of this project is to accurately predict the bias of MCNP6 [1] criticality calculations using machine learning (ML) algorithms, with the intention of creating a tool that can complement the current nuclear criticality safety methods. In the latest release of MCNP6, the Whisper tool is available for criticality safety analysts and includes a large catalogue of experimental benchmarks, sensitivity profiles, and nuclear data covariance matrices. This data, coming from 1100+ benchmark cases, is used in this study of ML algorithms for criticality safety bias predictions.

Control of long range turbulent transport with biasing in the tokamak scrape-off-layer

International Nuclear Information System (INIS)

Figarella, C.F.; Ghendrih, Ph.; Sarazin, Y.; Attuel, G.; Benkadda, S.; Beyer, P.; Falchetto, G.; Fleurence, E.; Garbet, X.; Grandgirard, V.

2005-01-01

Cross-field transport in the SOL influences tokamak performance in particular regarding the divertor efficiency. Recent experiment evidence emphasizes non-exponential and/or flat SOL profiles that suggest a large perpendicular transport. A 2D fluid model based on the interchange instability to simulate the SOL turbulence was found to exhibits intermittent dynamics of the particle flux. We propose a control method that prevents long range transport events from reaching the far SOL: It consists in biasing the far SOL leading to a transport barrier which stops the propagation of these intermittent events. The best trade off is to localize the biased toroidal ring around the baffles. We show that such a control is achievable providing the strength of the barrier is strong enough. The investigation of the minimal biasing power required to achieve the control as well as its experimental estimate is performed

Control of long range turbulent transport with biasing in the tokamak scrape-off-layer

International Nuclear Information System (INIS)

Figarella, C.F.; Ghendrih, Ph.; Sarazin, Y.; Attuel, G.; Falchetto, G.; Fleurence, E.; Garbet, X.; Grandgirard, V.

2004-01-01

Cross field transport in the SOL (scrape-off-layer) influences tokamak performance in particular regarding the divertor efficiency. Recent experiment evidence emphasizes non-exponential and/or flat SOL profiles that suggest a large perpendicular transport. A 2-dimensional fluid model based on the interchange instability to simulate the SOL turbulence was found to exhibits intermittent dynamics of the particle flux. We propose a control method that prevents long range transport events from reaching the far SOL: It consists in biasing the far SOL leading to a transport barrier which stops the propagation of these intermittent events. The best trade off is to localize the biased toroidal ring around the baffles. We show that such a control is achievable providing the strength of the barrier is strong enough. The investigation of the minimal biasing power required to achieve the control as well as its experimental estimate is performed. (authors)

Tomato Lycopene and Lung Cancer Prevention: From Experimental to Human Studies

Energy Technology Data Exchange (ETDEWEB)

Palozza, Paola, E-mail: p.palozza@rm.unicatt.it; Simone, Rossella E.; Catalano, Assunta [Institute of General Pathology, School of Medicine, Catholic University, L. Go F. Vito, Rome 1 00168 (Italy); Mele, Maria Cristina [Institute of Biochemistry and Clinical Biochemistry, School of Medicine, Catholic University, L. Go F. Vito, Rome 1 00168 (Italy)

2011-05-11

Increasing evidence suggests that tomato lycopene may be preventive against the formation and the development of lung cancer. Experimental studies demonstrated that lycopene may inhibit the growth of several cultured lung cancer cells and prevent lung tumorigenesis in animal models through various mechanisms, including a modulation of redox status, cell cycle arrest and/or apoptosis induction, a regulation of growth factor signaling, changes in cell growth-related enzymes, an enhancement of gap junction communication and a prevention of smoke-induced inflammation. In addition, lycopene also inhibited cell invasion, angiogenesis, and metastasis. Several lycopene metabolites have been identified, raising the question as to whether the preventive effects of lycopene on cancer risk is, at least in part, due to its metabolites. Despite these promising reports, it is difficult at the moment to directly relate available experimental data to human pathophysiology. More well controlled clinical intervention trials are needed to further clarify the exact role of lycopene in the prevention of lung cancer cell growth. Such studies should take into consideration subject selection, specific markers of analysis, the levels of carotenoids being tested, metabolism and isomerization of lycopene, interaction with other bioactive food components. This article reviews data on the cancer preventive activities of lycopene, possible mechanisms involved, and the relationship between lycopene consumption and human cancer risk.

Tomato Lycopene and Lung Cancer Prevention: From Experimental to Human Studies

International Nuclear Information System (INIS)

Palozza, Paola; Simone, Rossella E.; Catalano, Assunta; Mele, Maria Cristina

2011-01-01

Increasing evidence suggests that tomato lycopene may be preventive against the formation and the development of lung cancer. Experimental studies demonstrated that lycopene may inhibit the growth of several cultured lung cancer cells and prevent lung tumorigenesis in animal models through various mechanisms, including a modulation of redox status, cell cycle arrest and/or apoptosis induction, a regulation of growth factor signaling, changes in cell growth-related enzymes, an enhancement of gap junction communication and a prevention of smoke-induced inflammation. In addition, lycopene also inhibited cell invasion, angiogenesis, and metastasis. Several lycopene metabolites have been identified, raising the question as to whether the preventive effects of lycopene on cancer risk is, at least in part, due to its metabolites. Despite these promising reports, it is difficult at the moment to directly relate available experimental data to human pathophysiology. More well controlled clinical intervention trials are needed to further clarify the exact role of lycopene in the prevention of lung cancer cell growth. Such studies should take into consideration subject selection, specific markers of analysis, the levels of carotenoids being tested, metabolism and isomerization of lycopene, interaction with other bioactive food components. This article reviews data on the cancer preventive activities of lycopene, possible mechanisms involved, and the relationship between lycopene consumption and human cancer risk

Tomato Lycopene and Lung Cancer Prevention: From Experimental to Human Studies

Directory of Open Access Journals (Sweden)

Assunta Catalano

2011-05-01

Full Text Available Increasing evidence suggests that tomato lycopene may be preventive against the formation and the development of lung cancer. Experimental studies demonstrated that lycopene may inhibit the growth of several cultured lung cancer cells and prevent lung tumorigenesis in animal models through various mechanisms, including a modulation of redox status, cell cycle arrest and/or apoptosis induction, a regulation of growth factor signaling, changes in cell growth-related enzymes, an enhancement of gap junction communication and a prevention of smoke-induced inflammation. In addition, lycopene also inhibited cell invasion, angiogenesis, and metastasis. Several lycopene metabolites have been identified, raising the question as to whether the preventive effects of lycopene on cancer risk is, at least in part, due to its metabolites. Despite these promising reports, it is difficult at the moment to directly relate available experimental data to human pathophysiology. More well controlled clinical intervention trials are needed to further clarify the exact role of lycopene in the prevention of lung cancer cell growth. Such studies should take into consideration subject selection, specific markers of analysis, the levels of carotenoids being tested, metabolism and isomerization of lycopene, interaction with other bioactive food components. This article reviews data on the cancer preventive activities of lycopene, possible mechanisms involved, and the relationship between lycopene consumption and human cancer risk.

An experimental investigation of recruitment bias in eating pathology research.

Science.gov (United States)

Moss, Erin L; von Ranson, Kristin M

2006-04-01

Previous, uncontrolled research has suggested a bias may exist in recruiting participants for eating disorder research. Recruitment biases may affect sample representativeness and generalizability of findings. This experiment investigated whether revealing that a study's topic was related to eating disorders created a self-selection bias. Young women at a university responded to advertisements containing contrasting information about the nature of a single study. We recruited one group by advertising the study under the title "Disordered Eating in Young Women" (n = 251) and another group using the title "Consumer Preferences" (n = 259). Results indicated similar levels of eating pathology in both groups, so the different recruitment techniques did not engender self-selection. However, the consumer preferences group scored higher in self-reported social desirability. The level of information conveyed in study advertising does not impact reporting of eating disturbances among nonclinical samples, although there is evidence social desirability might. 2006 by Wiley Periodicals, Inc.

Attentional bias in excessive Internet gamers: Experimental investigations using an addiction Stroop and a visual probe.

Science.gov (United States)

Jeromin, Franziska; Nyenhuis, Nele; Barke, Antonia

2016-03-01

Background and aims Internet Gaming Disorder is included in the Diagnostic and statistical manual of mental disorders (5 th edition) as a disorder that merits further research. The diagnostic criteria are based on those for Substance Use Disorder and Gambling Disorder. Excessive gamblers and persons with Substance Use Disorder show attentional biases towards stimuli related to their addictions. We investigated whether excessive Internet gamers show a similar attentional bias, by using two established experimental paradigms. Methods We measured reaction times of excessive Internet gamers and non-gamers (N = 51, 23.7 ± 2.7 years) by using an addiction Stroop with computer-related and neutral words, as well as a visual probe with computer-related and neutral pictures. Mixed design analyses of variance with the between-subjects factor group (gamer/non-gamer) and the within-subjects factor stimulus type (computer-related/neutral) were calculated for the reaction times as well as for valence and familiarity ratings of the stimulus material. Results In the addiction Stroop, an interaction for group × word type was found: Only gamers showed longer reaction times to computer-related words compared to neutral words, thus exhibiting an attentional bias. In the visual probe, no differences in reaction time between computer-related and neutral pictures were found in either group, but the gamers were faster overall. Conclusions An attentional bias towards computer-related stimuli was found in excessive Internet gamers, by using an addiction Stroop but not by using a visual probe. A possible explanation for the discrepancy could lie in the fact that the visual probe may have been too easy for the gamers.

Sexual Violence Prevention through Bystander Education: An Experimental Evaluation

Science.gov (United States)

Banyard, Victoria L.; Moynihan, Mary M.; Plante, Elizabethe G.

2007-01-01

The current study used an experimental design to evaluate a sexual violence prevention program based on a community of responsibility model that teaches women and men how to intervene safely and effectively in cases of sexual violence before, during, and after incidents with strangers, acquaintances, or friends. It approaches both women and men as…

Decreased zinc in the development and progression of malignancy: an important common relationship and potential for prevention and treatment of carcinomas

Science.gov (United States)

Costello, Leslie C.; Franklin, Renty B.

2016-01-01

Introduction Efficacious chemotherapy does not exist for treatment or prevention of prostate, liver, and pancreatic carcinomas, and some other cancers that exhibit decreased zinc in malignancy. Zinc treatment offers a potential solution; but its support has been deterred by adverse bias. Areas covered 1. The clinical and experimental evidence for the common ZIP transporter/Zn down regulation in these cancers. 2. The evidence for a zinc approach to prevent and/or treat these carcinomas. 3. The issues that introduce bias against support for the zinc approach. Expert opinion ZIP/Zn downregulation is a clinically established common event in prostate, hepatocellular and pancreatic cancers. 2. Compelling evidence supports the plausibility that a zinc treatment regimen will prevent development of malignancy and termination of progressing malignancy in these cancers; and likely other carcinomas that exhibit decreased zinc. 3. Scientifically-unfounded issues that oppose this ZIP/Zn relationship have introduced bias against support for research and funding of a zinc treatment approach. 4. The clinically-established and supporting experimental evidence provide the scientific credibility that should dictate the support for research and funding of a zinc approach for the treatment and possible prevention of these cancers. 5. This is in the best interest of the medical community and the public-at-large. PMID:27885880

Integrating weight bias awareness and mental health promotion into obesity prevention delivery: a public health pilot study.

Science.gov (United States)

McVey, Gail L; Walker, Kathryn S; Beyers, Joanne; Harrison, Heather L; Simkins, Sari W; Russell-Mayhew, Shelly

2013-04-04

Promoting healthy weight is a top priority in Canada. Recent federal guidelines call for sustained, multisectoral partnerships that address childhood obesity on multiple levels. Current healthy weight messaging does not fully acknowledge the influence of social determinants of health on weight. An interactive workshop was developed and implemented by a team of academic researchers and health promoters from the psychology and public health disciplines to raise awareness about 1) weight bias and its negative effect on health, 2) ways to balance healthy weight messaging to prevent the triggering of weight and shape preoccupation, and 3) the incorporation of mental health promotion into healthy weight messaging. We conducted a full-day workshop with 342 Ontario public health promoters and administered a survey at preintervention, postintervention, and follow-up. Participation in the full-day workshop led to significant decreases in antifat attitudes and the internalization of media stereotypes and to significant increases in self-efficacy to address weight bias. Participants reported that the training heightened their awareness of their own personal weight biases and the need to broaden their scope of healthy weight promotion to include mental health promotion. There was consensus that additional sessions are warranted to help translate knowledge into action. Buy-in and resource support at the organizational level was also seen as pivotal. Professional development training in the area of weight bias awareness is associated with decreases in antifat attitudes and the internalization of media stereotypes around thinness. Health promoters' healthy weight messaging was improved by learning to avoid messages that trigger weight and shape preoccupation or unhealthful eating practices among children and youth. Participants also learned ways to integrate mental health promotion and resiliency-building into daily practice.

Simulation of HPIB propagation in biased charge collector

International Nuclear Information System (INIS)

Li Hongyu; Qiu Aici

2004-01-01

A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB is presented. The simulation results indicate that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. -800 V biased voltage can meet the measurement of 500 keV HPIB, and this is consistent with the experimental results

Information-Pooling Bias in Collaborative Security Incident Correlation Analysis.

Science.gov (United States)

Rajivan, Prashanth; Cooke, Nancy J

2018-03-01

Incident correlation is a vital step in the cybersecurity threat detection process. This article presents research on the effect of group-level information-pooling bias on collaborative incident correlation analysis in a synthetic task environment. Past research has shown that uneven information distribution biases people to share information that is known to most team members and prevents them from sharing any unique information available with them. The effect of such biases on security team collaborations are largely unknown. Thirty 3-person teams performed two threat detection missions involving information sharing and correlating security incidents. Incidents were predistributed to each person in the team based on the hidden profile paradigm. Participant teams, randomly assigned to three experimental groups, used different collaboration aids during Mission 2. Communication analysis revealed that participant teams were 3 times more likely to discuss security incidents commonly known to the majority. Unaided team collaboration was inefficient in finding associations between security incidents uniquely available to each member of the team. Visualizations that augment perceptual processing and recognition memory were found to mitigate the bias. The data suggest that (a) security analyst teams, when conducting collaborative correlation analysis, could be inefficient in pooling unique information from their peers; (b) employing off-the-shelf collaboration tools in cybersecurity defense environments is inadequate; and (c) collaborative security visualization tools developed considering the human cognitive limitations of security analysts is necessary. Potential applications of this research include development of team training procedures and collaboration tool development for security analysts.

Social biases modulate the loss of redundant forms in the cultural evolution of language.

Science.gov (United States)

Roberts, Gareth; Fedzechkina, Maryia

2018-02-01

According to the competitive exclusion principle (Gause, 1934), competition for the same niche must eventually lead one competitor to extinction or the occupation of a new niche. This principle applies in both biology and the cultural evolution of language, where different words and structures compete for the same function or meaning (Aronoff, 2016). Across languages, for example, word order trades off with case marking as a means of indicating who did what to whom in a sentence. Previous experimental work has shed light on how such trade-offs come about as languages adapt to human biases through learning and production, with biases becoming amplified through iterated learning over generations. At the same time, a large body of work has documented the impact of social biases on language change. However, little work has investigated how social biases interact with learning and production biases. In particular, the social dimension of language may provide alternative niches for otherwise redundant forms, preventing or slowing their extinction. We tested this hypothesis in an iterated-learning experiment in which participants were exposed to a language with two dialects, both of which had fixed word order, but differed in whether they employed case markers. In one condition, we biased participants socially towards speakers of the dialect that employed case; in other conditions we provided no bias, or biased participants for or against the dialect without case. As expected under our hypothesis, the use of case markers declined over time in all conditions, but the social bias in favor of case-dialect speakers slowed the decline. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental Research Into High Barometric Oxygen Prevention of Guinea Pig Hearing Loss,

Science.gov (United States)

1992-08-28

PREVENTION OF GUINEA PIG HEARING LOSS by Yin Jiacai, Sun Fang ren, et al. DTIC MLECTE •<• EP 2 9 1992 Approved for public release, Distribution unlimited...PREVENTION OF GUINEA PIG HEARING LOSS By: Yin Jiacai, Sun Fang ren, et al. English pages: 9 Source: Chung-Hua I Shueh Tsa Chih, Vol. 65, Nr. 11, Nov.eember...Distributionf._DL~~~t .•b • / or __ Dlist szeccat .lef ’ ~1 EXPERIMENTAL RESEARCH INTO HIGH BAROMETRIC OXYGEN PREVENTION OF GUINEA PIG HEARING LOSS BY: Yin

Bias Assessment of General Chemistry Analytes using Commutable Samples.

Science.gov (United States)

Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham Rd; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

2014-11-01

Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.

Individuals with clinically significant insomnia symptoms are characterised by a negative sleep-related expectancy bias: Results from a cognitive-experimental assessment.

Science.gov (United States)

Courtauld, Hannah; Notebaert, Lies; Milkins, Bronwyn; Kyle, Simon D; Clarke, Patrick J F

2017-08-01

Cognitive models of insomnia consistently suggest that negative expectations regarding the consequences of poor sleep contribute to the maintenance of insomnia. To date, however, no research has sought to determine whether insomnia is indeed characterised by such a negative sleep-related expectancy bias, using objective cognitive assessment tasks which are more immune to response biases than questionnaire assessments. Therefore, the current study employed a reaction-time task assessing biased expectations among a group with clinically significant insomnia symptoms (n = 30) and a low insomnia symptoms group (n = 40). The task involved the presentation of scenarios describing the consequences of poor sleep, and non-sleep related activities, which could be resolved in a benign or a negative manner. The results demonstrated that the high insomnia symptoms group were disproportionately fast to resolve sleep-related scenarios in line with negative outcomes, as compared to benign outcomes, relative to the low insomnia symptoms group. The two groups did not differ in their pattern of resolving non-sleep related scenarios. This pattern of findings is entirely consistent with a sleep-specific expectancy bias operating in individuals with clinically significant insomnia symptoms, and highlights the potential of cognitive-experimental assessment tasks to objectively index patterns of biased cognition in insomnia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual search attentional bias modification reduced social phobia in adolescents

NARCIS (Netherlands)

de Voogd, E.L.; Wiers, R.W.; Prins, P.J.M.; Salemink, E.

2014-01-01

Background and objectives: An attentional bias for negative information plays an important role in the development and maintenance of (social) anxiety and depression, which are highly prevalent in adolescence. Attention Bias Modification (ABM) might be an interesting tool in the prevention of

Optimization of preventive maintenance cycle based on experimental feedback in nuclear power plants

International Nuclear Information System (INIS)

Shi Jie

2010-01-01

The preventive replacement method based on the experimental feedback was introduced. In this method, the initial preventive replacement cycle was acquired by expert votes. The preventive replacement cycle combined with the operation experience of the equipment was gained by means of Bayesian theorem. The Optimized preventive replacement cycle can be acquired by comparing the two probabilities that no fault occurs within the cycle. This method was tested on the switches which were used in Daya Bay Nuclear Power Plant and the results indicated its validity. (authors)

Production bias and cluster annihilation: Why necessary?

DEFF Research Database (Denmark)

Singh, B.N.; Trinkaus, H.; Woo, C.H.

1994-01-01

the primary cluster density is high. Therefore, a sustained high swelling rate driven by production bias must involve the annihilation of primary clusters at sinks. A number of experimental observations which are unexplainable in terms of the conventional dislocation bias for monointerstitials is considered......-field approach. The production bias approach, on the other hand, is based on the physical features of the cascade damage and is therefore considered to be more appropriate for describing the damage accumulation under cascade damage conditions. However, production bias can not produce high a swelling rate when....... It is found that the production bias and cluster annihilation are necessary to explain these observations, with, in many cases, the explicit consideration of the annihilation of the primary interstitial clusters....

Clinical effectiveness of attentional bias modification training in abstinent alcoholic patients

NARCIS (Netherlands)

Schoenmakers, T.M.; Bruin, de M.; Lux, I.F.M.; Goertz, A.G.; Kerkhof, van D.H.A.T.; Wiers, R.W.

2010-01-01

A new training to decrease attentional bias (attentional bias modification training, ABM) was tested in a randomized controlled experimental study with alcohol-dependent patients as an addition to cognitive behavioral therapy. In alcohol dependence, attentional bias has been associated with severity

A Question of Control? Examining the Role of Control Conditions in Experimental Psychopathology using the Example of Cognitive Bias Modification Research.

Science.gov (United States)

Blackwell, Simon E; Woud, Marcella L; MacLeod, Colin

2017-10-26

While control conditions are vitally important in research, selecting the optimal control condition can be challenging. Problems are likely to arise when the choice of control condition is not tightly guided by the specific question that a given study aims to address. Such problems have become increasingly apparent in experimental psychopathology research investigating the experimental modification of cognitive biases, particularly as the focus of this research has shifted from theoretical questions concerning mechanistic aspects of the association between cognitive bias and emotional vulnerability, to questions that instead concern the clinical efficacy of 'cognitive bias modification' (CBM) procedures. We discuss the kinds of control conditions that have typically been employed in CBM research, illustrating how difficulties can arise when changes in the types of research questions asked are not accompanied by changes in the control conditions employed. Crucially, claims made on the basis of comparing active and control conditions within CBM studies should be restricted to those conclusions allowed by the specific control condition employed. CBM studies aiming to establish clinical utility are likely to require quite different control conditions from CBM studies aiming to illuminate mechanisms. Further, conclusions concerning the clinical utility of CBM interventions cannot necessarily be drawn from studies in which the control condition has been chosen to answer questions concerning mechanisms. Appreciating the need to appropriately alter control conditions in the transition from basic mechanisms-focussed investigations to applied clinical research could greatly facilitate the translational process.

Bias against research on gender bias.

Science.gov (United States)

Cislak, Aleksandra; Formanowicz, Magdalena; Saguy, Tamar

2018-01-01

The bias against women in academia is a documented phenomenon that has had detrimental consequences, not only for women, but also for the quality of science. First, gender bias in academia affects female scientists, resulting in their underrepresentation in academic institutions, particularly in higher ranks. The second type of gender bias in science relates to some findings applying only to male participants, which produces biased knowledge. Here, we identify a third potentially powerful source of gender bias in academia: the bias against research on gender bias. In a bibliometric investigation covering a broad range of social sciences, we analyzed published articles on gender bias and race bias and established that articles on gender bias are funded less often and published in journals with a lower Impact Factor than articles on comparable instances of social discrimination. This result suggests the possibility of an underappreciation of the phenomenon of gender bias and related research within the academic community. Addressing this meta-bias is crucial for the further examination of gender inequality, which severely affects many women across the world.

Attentional Bias towards Positive Emotion Predicts Stress Resilience.

Science.gov (United States)

Thoern, Hanna A; Grueschow, Marcus; Ehlert, Ulrike; Ruff, Christian C; Kleim, Birgit

2016-01-01

There is extensive evidence for an association between an attentional bias towards emotionally negative stimuli and vulnerability to stress-related psychopathology. Less is known about whether selective attention towards emotionally positive stimuli relates to mental health and stress resilience. The current study used a modified Dot Probe task to investigate if individual differences in attentional biases towards either happy or angry emotional stimuli, or an interaction between these biases, are related to self-reported trait stress resilience. In a nonclinical sample (N = 43), we indexed attentional biases as individual differences in reaction time for stimuli preceded by either happy or angry (compared to neutral) face stimuli. Participants with greater attentional bias towards happy faces (but not angry faces) reported higher trait resilience. However, an attentional bias towards angry stimuli moderated this effect: The attentional bias towards happy faces was only predictive for resilience in those individuals who also endorsed an attentional bias towards angry stimuli. An attentional bias towards positive emotional stimuli may thus be a protective factor contributing to stress resilience, specifically in those individuals who also endorse an attentional bias towards negative emotional stimuli. Our findings therefore suggest a novel target for prevention and treatment interventions addressing stress-related psychopathology.

Cognitive Dissonance, Confirmatory Bias and Inadequate Information Processing: Evidence from Experimental Auctions

OpenAIRE

Cao, Ying; Just, David R.; Wansink, Brian

2014-01-01

Using psychological terms such as cognitive dissonance and confirmation bias, this study reveals how individual consumers inadequately process (food safety) information, pay limited attention to signals, and make purchase decisions that are bias towards their initial choices. While it is expected that reading extra information about potential risk associated with the food decreases consumers' willingness to pay (WTP), the magnitude of the impact varies across individuals. In general, consumer...

Attention bias for chocolate increases chocolate consumption--an attention bias modification study.

Science.gov (United States)

Werthmann, Jessica; Field, Matt; Roefs, Anne; Nederkoorn, Chantal; Jansen, Anita

2014-03-01

The current study examined experimentally whether a manipulated attention bias for food cues increases craving, chocolate intake and motivation to search for hidden chocolates. To test the effect of attention for food on subsequent chocolate intake, attention for chocolate was experimentally modified by instructing participants to look at chocolate stimuli ("attend chocolate" group) or at non-food stimuli ("attend shoes" group) during a novel attention bias modification task (antisaccade task). Chocolate consumption, changes in craving and search time for hidden chocolates were assessed. Eye-movement recordings were used to monitor the accuracy during the experimental attention modification task as possible moderator of effects. Regression analyses were conducted to test the effect of attention modification and modification accuracy on chocolate intake, craving and motivation to search for hidden chocolates. Results showed that participants with higher accuracy (+1 SD), ate more chocolate when they had to attend to chocolate and ate less chocolate when they had to attend to non-food stimuli. In contrast, for participants with lower accuracy (-1 SD), the results were exactly reversed. No effects of the experimental attention modification on craving or search time for hidden chocolates were found. We used chocolate as food stimuli so it remains unclear how our findings generalize to other types of food. These findings demonstrate further evidence for a link between attention for food and food intake, and provide an indication about the direction of this relationship. Copyright © 2013 Elsevier Ltd. All rights reserved.

Demand artifact: objectively detecting biased participants in advertising research.

Science.gov (United States)

Miller, Felicia; Schertzer, Susan

2014-12-01

Detecting and reducing the effect of biased participants continues to be an important task for researchers. However, the lack of objective measures to assess demand artifact has made it difficult to effectively address this issue. This paper reports two experiments that apply a theory-based post-experimental inquiry that can systematically identify biased participants in consumer research. The results demonstrate how easily and effectively researchers can incorporate this tool into experimental studies of all types and reduce the likelihood of systematic error.

Cognitive Biases in Children and Adolescents With Chronic Pain: A Review of Findings and a Call for Developmental Research.

Science.gov (United States)

Lau, Jennifer Y F; Heathcote, Lauren C; Beale, Sarah; Gray, Suzy; Jacobs, Konrad; Wilkinson, Nick; Crombez, Geert

2018-06-01

Cognitive biases that emphasize bodily harm, injury, and illness could play a role in the maintenance of chronic pain by facilitating fear and avoidance. Whereas extensive research has established attention, interpretation, and memory biases in adults with chronic pain, far less is known about these same biases in children and adolescents with pain. Studying cognitive biases in attention, interpretation, and memory in relation to pain occurring in youth is important because youth is a time when pain can first become chronic, and when relationships between cognitive biases and pain outcomes emerge and stabilize. Thus, youth potentially offers a time window for the prevention of chronic pain problems. In this article, we summarize the growing corpus of data that have measured cognitive biases in relation to pediatric pain. We conclude that although biases in attention, interpretation, and memory characterize children and adolescents with varying pain experiences, questions regarding the direction, magnitude, nature, and role of these biases remain. We call for independent extension of cognitive bias research in children and adolescents, using well powered longitudinal studies with wide age ranges and psychometrically sound experimental measures to clarify these findings and any developmental trends in the links between cognitive biases and pain outcomes. This article provides a rationale for the theoretical and practical importance of studying the role of cognitive biases in children and adolescents with chronic pain, which has to date, been relatively understudied. Existing findings are reviewed critically, and recommendations for future research are offered. Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Bias stress effect and recovery in organic field effect transistors : proton migration mechanism

NARCIS (Netherlands)

Sharma, A.; Mathijssen, S.G.J.; Kemerink, M.; Leeuw, de D.M.; Bobbert, P.A.; Bao, Z.; McCulloch, I.

2010-01-01

Organic field-effect transistors exhibit operational instabilities when a gate bias is applied. For a constant gate bias the threshold voltage shifts towards the applied gate bias voltage, an effect known as the bias-stress effect. We have performed a detailed experimental and theoretical study of

Biased limiter experiments on text

International Nuclear Information System (INIS)

Phillips, P.E.; Wootton, A.J.; Rowan, W.L.; Ritz, C.P.; Rhodes, T.L.; Bengtson, R.D.; Hodge, W.L.; Durst, R.D.; McCool, S.C.; Richards, B.; Gentle, K.W.; Schoch, P.; Forster, J.C.; Hickok, R.L.; Evans, T.E.

1987-01-01

Experiments using an electrically biased limiter have been performed on the Texas Experimental Tokamak (TEXT). A small movable limiter is inserted past the main poloidal ring limiter (which is electrically connected to the vacuum vessel) and biased at V Lim with respect to it. The floating potential, plasma potential and shear layer position can be controlled. With vertical strokeV Lim vertical stroke ≥ 50 V the plasma density increases. For V Lim Lim > 0 the results obtained are inconclusive. Variation of V Lim changes the electrostatic turbulence which may explain the observed total flux changes. (orig.)

Asymmetry of edge plasma turbulence in biasing experiments on tokamak TF-2

International Nuclear Information System (INIS)

Budaev, V.P.

1994-01-01

It was observed in tokamaks the suppression of edge turbulence causes by setting a radial electric field at the plasma edge. The poloidal plasma rotation governed by this electric field is likely to result in changes in edge convention and poloidal asymmetry, however there is no experimental evidence about that of the experimental database concerning the biasing and conditions of edge plasma electrostatic turbulence excitation is not still complete. Also a relation between macroscopic convection and small-scale electrostatic turbulence have not yet revealed both in biasing and non biasing plasmas. In this paper results from biasing experiments carried on on ohmically heated tokamak TF-2 are presented. Changes in both equilibrium and fluctuated edge plasma parameters also convection and turbulence driven particle flux were demonstrated in probe measurements with biasing of electrode immersed within Last Closed Flux Surface (LCFS). Poloidal edge plasma structure and charge in asymmetry have demonstrated in the biasing experiments. (author). 6 refs, 4 figs

Gender bias in teaching evaluations

NARCIS (Netherlands)

Mengel, Friederike; Sauermann, Jan; Zölitz, Ulf Zoelitz

2017-01-01

This paper provides new evidence on gender bias in teaching evaluations. We exploit a quasi-experimental dataset of 19,952 student evaluations of university faculty in a context where students are randomly allocated to female or male instructors. Despite the fact that neither students’ grades nor

Tax-Rate Biases in Tax-Planning Decisions: Experimental Evidence

OpenAIRE

Amberger, Harald; Eberhartinger, Eva; Kasper, Helmut

2016-01-01

Contrary to standard economic theory, recent empirical findings suggest that firms do not always engage in economically optimal tax planning. We conduct a laboratory experiment and find robust evidence that decision biases offer a behavioral explanation for suboptimal tax planning. When facing time pressure in an intra-group cross-border financing decision, subjects apply heuristics based on the salience of statutory tax rates. This stirs decision makers to underestimate the effects of tax-ba...

Effects of Bias Modification Training in Binge Eating Disorder.

Science.gov (United States)

Schmitz, Florian; Svaldi, Jennifer

2017-09-01

Food-related attentional biases have been identified as maintaining factors in binge eating disorder (BED) as they can trigger a binge episode. Bias modification training may reduce symptoms, as it has been shown to be successful in other appetitive disorders. The aim of this study was to assess and modify food-related biases in BED. It was tested whether biases could be increased and decreased by means of a modified dot-probe paradigm, how long such bias modification persisted, and whether this affected subjective food craving. Participants were randomly assigned to a bias enhancement (attend to food stimulus) group or to a bias reduction (avoid food stimulus) group. Food-related attentional bias was found to be successfully reduced in the bias-reduction group, and effects persisted briefly. Additionally, subjective craving for food was influenced by the intervention, and possible mechanisms are discussed. Given these promising initial results, future research should investigate boundary conditions of the experimental intervention to understand how it could complement treatment of BED. Copyright © 2017. Published by Elsevier Ltd.

An Introduction to Sensitivity Analysis for Unobserved Confounding in Non-Experimental Prevention Research

Science.gov (United States)

Kuramoto, S. Janet; Stuart, Elizabeth A.

2013-01-01

Despite that randomization is the gold standard for estimating causal relationships, many questions in prevention science are left to be answered through non-experimental studies often because randomization is either infeasible or unethical. While methods such as propensity score matching can adjust for observed confounding, unobserved confounding is the Achilles heel of most non-experimental studies. This paper describes and illustrates seven sensitivity analysis techniques that assess the sensitivity of study results to an unobserved confounder. These methods were categorized into two groups to reflect differences in their conceptualization of sensitivity analysis, as well as their targets of interest. As a motivating example we examine the sensitivity of the association between maternal suicide and offspring’s risk for suicide attempt hospitalization. While inferences differed slightly depending on the type of sensitivity analysis conducted, overall the association between maternal suicide and offspring’s hospitalization for suicide attempt was found to be relatively robust to an unobserved confounder. The ease of implementation and the insight these analyses provide underscores sensitivity analysis techniques as an important tool for non-experimental studies. The implementation of sensitivity analysis can help increase confidence in results from non-experimental studies and better inform prevention researchers and policymakers regarding potential intervention targets. PMID:23408282

Opening the black box: From an individual bias to portfolio performance

OpenAIRE

Nosic, Alen; Weber, Martin; Glaser, Markus

2011-01-01

We suggest an experimental design that can help opening the black box of investor behavior by documenting a channel of how biases affect portfolio performance. We study two of the most important investor biases (overreaction and overconfidence), show how they are related, and analyze their consequences for portfolio choice and resulting portfolio performance in a controlled experimental setting with 104 participants. The main innovation of our study is that we go beyond just documenting a cor...

Rf-biasing of highly idealized plasmas

NARCIS (Netherlands)

Westermann, R.H.J.; Blauw, M.A.; Goedheer, W.J.; Sanden, van de M.C.M.; Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.

2007-01-01

Remote plasmas, which are subjected to a radio-frequency (RF) biased surface, have been investigated theoretically and experimentally for decades. The relation between the complex power (DC) voltage characteristics, the ion energy distribution and control losses of the ion bombardment are of

Analysis of microstructural evolution driven by production bias

International Nuclear Information System (INIS)

Woo, C.H.; Semenov, A.A.; Singh, B.N.

1993-01-01

The concept of production bias was first considered in the preceding workshop in this series at Silkeborg in 1989. Since then, much work has been done to investigate the validity of the concept, and its usefulness in complementing the current theory of microstructure evolution based solely on the sink bias (e.g., dislocation bias) as a driving force. Comparison of the theory with experimental results clearly supports the concept. The present paper reviews and summarizes these investigations, and arrives at the following conclusions: a) the concept of production bias is consistent with the results of other works which indicates that, under cascade damage conditions, the effective rate of point-defect production is only a small fraction of the NRT displacement production rate; b) the defect accumulation under cascade damage conditions can be understood in terms of production bias; and c) although the existence of conventional dislocation bias due to point-defect dislocation interaction is not questioned, it does not seem to play any major role in the accumulation of defects under cascade damage conditions at elevated temperatures. (orig.)

Systematic approach to establishing criticality biases

International Nuclear Information System (INIS)

Larson, S.L.

1995-09-01

A systematic approach has been developed to determine benchmark biases and apply those biases to code results to meet the requirements of DOE Order 5480.24 regarding documenting criticality safety margins. Previously, validation of the code against experimental benchmarks to prove reasonable agreement was sufficient. However, DOE Order 5480.24 requires contractors to adhere to the requirements of ANSI/ANS-8.1 and establish subcritical margins. A method was developed to incorporate biases and uncertainties from benchmark calculations into a k eff value with quantifiable uncertainty. The method produces a 95% confidence level in both the k eff value of the scenario modeled and the distribution of the k eff S calculated by the Monte Carlo code. Application of the method to a group of benchmarks modeled using the KENO-Va code and the SCALE 27 group cross sections is also presented

Specificity and overlap of attention and memory biases in depression.

Science.gov (United States)

Marchetti, Igor; Everaert, Jonas; Dainer-Best, Justin; Loeys, Tom; Beevers, Christopher G; Koster, Ernst H W

2018-01-01

Attentional and memory biases are viewed as crucial cognitive processes underlying symptoms of depression. However, it is still unclear whether these two biases are uniquely related to depression or whether they show substantial overlap. We investigated the degree of specificity and overlap of attentional and memory biases for depressotypic stimuli in relation to depression and anxiety by means of meta-analytic commonality analysis. By including four published studies, we considered a pool of 463 healthy and subclinically depressed individuals, different experimental paradigms, and different psychological measures. Memory bias is reliably and strongly related to depression and, specifically, to symptoms of negative mood, worthlessness, feelings of failure, and pessimism. Memory bias for negative information was minimally related to anxiety. Moreover, neither attentional bias nor the overlap between attentional and memory biases were significantly related to depression. Limitations include cross-sectional nature of the study. Our study showed that, across different paradigms and psychological measures, memory bias (and not attentional bias) represents a primary mechanism in depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing Projection Bias in Consumers' Food Preferences.

Directory of Open Access Journals (Sweden)

Tiziana de-Magistris

Full Text Available The aim of this study is to test whether projection bias exists in consumers' purchasing decisions for food products. To achieve our aim, we used a non-hypothetical experiment (i.e., experimental auction, where hungry and non-hungry participants were incentivized to reveal their willingness to pay (WTP. The results confirm the existence of projection bias when consumers made their decisions on food products. In particular, projection bias existed because currently hungry participants were willing to pay a higher price premium for cheeses than satiated ones, both in hungry and satiated future states. Moreover, participants overvalued the food product more when they were delivered in the future hungry condition than in the satiated one. Our study provides clear, quantitative and meaningful evidence of projection bias because our findings are based on economic valuation of food preferences. Indeed, the strength of this study is that findings are expressed in terms of willingness to pay which is an interpretable amount of money.

Variable-bias coin tossing

International Nuclear Information System (INIS)

Colbeck, Roger; Kent, Adrian

2006-01-01

Alice is a charismatic quantum cryptographer who believes her parties are unmissable; Bob is a (relatively) glamorous string theorist who believes he is an indispensable guest. To prevent possibly traumatic collisions of self-perception and reality, their social code requires that decisions about invitation or acceptance be made via a cryptographically secure variable-bias coin toss (VBCT). This generates a shared random bit by the toss of a coin whose bias is secretly chosen, within a stipulated range, by one of the parties; the other party learns only the random bit. Thus one party can secretly influence the outcome, while both can save face by blaming any negative decisions on bad luck. We describe here some cryptographic VBCT protocols whose security is guaranteed by quantum theory and the impossibility of superluminal signaling, setting our results in the context of a general discussion of secure two-party computation. We also briefly discuss other cryptographic applications of VBCT

Variable-bias coin tossing

Science.gov (United States)

Colbeck, Roger; Kent, Adrian

2006-03-01

Alice is a charismatic quantum cryptographer who believes her parties are unmissable; Bob is a (relatively) glamorous string theorist who believes he is an indispensable guest. To prevent possibly traumatic collisions of self-perception and reality, their social code requires that decisions about invitation or acceptance be made via a cryptographically secure variable-bias coin toss (VBCT). This generates a shared random bit by the toss of a coin whose bias is secretly chosen, within a stipulated range, by one of the parties; the other party learns only the random bit. Thus one party can secretly influence the outcome, while both can save face by blaming any negative decisions on bad luck. We describe here some cryptographic VBCT protocols whose security is guaranteed by quantum theory and the impossibility of superluminal signaling, setting our results in the context of a general discussion of secure two-party computation. We also briefly discuss other cryptographic applications of VBCT.

Preventative and Therapeutic Probiotic Use in Allergic Skin Conditions: Experimental and Clinical Findings

Science.gov (United States)

Özdemir, Öner; Göksu Erol, Azize Yasemin

2013-01-01

Probiotics are ingested live microbes that can modify intestinal microbial populations in a way that benefits the host. The interest in probiotic preventative/therapeutic potential in allergic diseases stemmed from the fact that probiotics have been shown to improve intestinal dysbiosis and permeability and to reduce inflammatory cytokines in human and murine experimental models. Enhanced presence of probiotic bacteria in the intestinal microbiota is found to correlate with protection against allergy. Therefore, many studies have been recently designed to examine the efficacy of probiotics, but the literature on the allergic skin disorders is still very scarce. Here, our objective is to summarize and evaluate the available knowledge from randomized or nonrandomized controlled trials of probiotic use in allergic skin conditions. Clinical improvement especially in IgE-sensitized eczema and experimental models such as atopic dermatitis-like lesions (trinitrochlorobenzene and picryl chloride sensitizations) and allergic contact dermatitis (dinitrofluorobenzene sensitization) has been reported. Although there is a very promising evidence to recommend the addition of probiotics into foods, probiotics do not have a proven role in the prevention or the therapy of allergic skin disorders. Thus, being aware of possible measures, such as probiotics use, to prevent/heal atopic diseases is essential for the practicing allergy specialist. PMID:24078929

An experimental study of spider-related covariation bias in 8-to 13-year-old children

NARCIS (Netherlands)

Muris, Peter; de Jong, Peter J.; Meesters, Cor; Waterreus, Bregje; van Lubeck, Janet

2005-01-01

Covariation bias can be defined as phobic subjects' tendency to overestimate the association between phobic stimuli and aversive outcomes. The current study presents two experiments that examined this type of cognitive bias in children aged 8-13 years (N = 147 in Experiment 1, N = 240 in Experiment

What's in a Trial? On the Importance of Distinguishing Between Experimental Lab Studies and Randomized Controlled Trials: The Case of Cognitive Bias Modification and Alcohol Use Disorders.

Science.gov (United States)

Wiers, Reinout W; Boffo, Marilisa; Field, Matt

2018-05-01

Recently, the National Institutes of Health (NIH) redefined clinical trials to include any study involving behavioral or biomedical interventions. In line with a general framework from experimental medicine, we argue that it is crucial to distinguish between experimental laboratory studies aimed at revealing psychological mechanisms underlying behavior and randomized controlled trials (RCTs) in clinical samples aimed at testing the efficacy of an intervention. As an illustration, we reviewed the current state of the evidence on the efficacy of cognitive bias modification (CBM) interventions in alcohol use disorders. A recent meta-analysis "cast serious doubts on the clinical utility of CBM interventions for addiction." That analysis combined experimental laboratory studies and RCTs. We demonstrated that, when studies are differentiated regarding study type (experimental laboratory study or RCT), mode of delivery (controlled experiment or Internet), and population (healthy volunteers or patients), the following effects are found: (a) short-lived effects of CBM on drinking behavior in experimental laboratory studies in students, but only when the bias is successfully manipulated; (b) small but robust effects of CBM on treatment outcome when administered as an adjunct to established treatments in clinical settings in RCTs with alcohol-dependent patients; and (c) nonspecific effects (reduced drinking irrespective of condition) in RCTs of CBM administered online to problem drinkers. We discuss how CBM might be improved when it is better integrated into regular treatment, especially cognitive behavioral therapy, and we conclude that disregarding the difference between experimental laboratory studies and RCTs can lead to invalid conclusions.

Attentional bias for craving-related (chocolate) food cues.

Science.gov (United States)

Kemps, Eva; Tiggemann, Marika

2009-12-01

In this study, we investigated attentional biases for craving-related food cues. A pictorial dot probe task was used to assess selective attentional processing of one particular highly desired food, namely chocolate, relative to that of other highly desired foods. In Experiment 1, we examined biased processing of chocolate cues in habitual (trait) chocolate cravers, whereas in Experiment 2 we investigated the effect of experimentally induced (state) chocolate cravings on such processing. As predicted, habitual chocolate cravers (Experiment 1) and individuals in whom a craving for chocolate was temporarily induced (Experiment 2) showed speeded detection of probes replacing chocolate-related pictures, demonstrating an attentional bias for chocolate cues. Subsequent examination indicated that in both experiments the observed attentional biases stemmed from difficulty in disengaging attention from chocolate cues rather than from a shift of attention toward such cues. The findings have important theoretical and practical implications.

Preventing halo bias in grading the work of university students

OpenAIRE

John M. Malouff; Sarah J. Stein; Lodewicka N. Bothma; Kimberley Coulter; Ashley J. Emmerton

2014-01-01

Experts have advocated anonymous marking as a means of minimizing bias in subjective student assessment. In the present study, 159 faculty members or teaching assistants across disciplines were randomly assigned (1) to grade a poor oral presentation of a university student, (2) to grade a good oral presentation of the same student, or (3) not to grade any oral presentation of the student. All graders then assessed the same written work by the student. A linear-contrasts analysis showed that, ...

The central tendency bias in color perception: effects of internal and external noise.

Science.gov (United States)

Olkkonen, Maria; McCarthy, Patrice F; Allred, Sarah R

2014-09-05

Perceptual estimates can be biased by previously seen stimuli in delayed estimation tasks. These biases are often toward the mean of the whole stimulus set. Recently, we demonstrated such a central tendency bias in delayed color estimation. In the Bayesian framework of perceptual inference, perceptual biases arise when noisy sensory measurements are combined with prior information about the world. Here, we investigate this idea in color perception by manipulating stimulus range and stimulus noise while characterizing delayed color estimates. First, we manipulated the experimental prior for stimulus color by embedding stimuli in collections with different hue ranges. Stimulus range affected hue bias: Hue estimates were always biased toward the mean of the current set. Next, we studied the effect of internal and external noise on the amount of hue bias. Internal noise was manipulated by increasing the delay between the reference and test from 0.4 to 4 s. External noise was manipulated by increasing the amount of chromatic noise in the reference stimulus, while keeping the delay between the reference and test constant at 2 s. Both noise manipulations had a reliable effect on the strength of the central tendency bias. Furthermore, there was a tendency for a positive relationship between variability of the estimates and bias in both noise conditions. In conclusion, observers are able to learn an experimental hue prior, and the weight on the prior can be manipulated by introducing noise in the estimation process. © 2014 ARVO.

Implicit and Explicit Memory Bias in Opiate Dependent, Abstinent and Normal Individuals

Directory of Open Access Journals (Sweden)

Jafar Hasani

2013-07-01

Full Text Available Objective: The aim of current research was to assess implicit and explicit memory bias to drug related stimuli in opiate Dependent, abstinent and normal Individuals. Method: Three groups including opiate Dependent, abstinent and normal Individuals (n=25 were selected by available sampling method. After matching on the base of age, education level and type of substance use all participants assessed by recognition task (explicit memory bias and stem completion task (implicit memory bias. Results: The analysis of data showed that opiate dependent and abstinent groups in comparison with normal individual had implicit memory bias, whereas in explicit memory only opiate dependent individuals showed bias. Conclusion: The identification of explicit and implicit memory governing addiction may have practical implications in diagnosis, treatment and prevention of substance abuse.

Biases in Visual, Auditory, and Audiovisual Perception of Space

Science.gov (United States)

Odegaard, Brian; Wozny, David R.; Shams, Ladan

2015-01-01

Localization of objects and events in the environment is critical for survival, as many perceptual and motor tasks rely on estimation of spatial location. Therefore, it seems reasonable to assume that spatial localizations should generally be accurate. Curiously, some previous studies have reported biases in visual and auditory localizations, but these studies have used small sample sizes and the results have been mixed. Therefore, it is not clear (1) if the reported biases in localization responses are real (or due to outliers, sampling bias, or other factors), and (2) whether these putative biases reflect a bias in sensory representations of space or a priori expectations (which may be due to the experimental setup, instructions, or distribution of stimuli). Here, to address these questions, a dataset of unprecedented size (obtained from 384 observers) was analyzed to examine presence, direction, and magnitude of sensory biases, and quantitative computational modeling was used to probe the underlying mechanism(s) driving these effects. Data revealed that, on average, observers were biased towards the center when localizing visual stimuli, and biased towards the periphery when localizing auditory stimuli. Moreover, quantitative analysis using a Bayesian Causal Inference framework suggests that while pre-existing spatial biases for central locations exert some influence, biases in the sensory representations of both visual and auditory space are necessary to fully explain the behavioral data. How are these opposing visual and auditory biases reconciled in conditions in which both auditory and visual stimuli are produced by a single event? Potentially, the bias in one modality could dominate, or the biases could interact/cancel out. The data revealed that when integration occurred in these conditions, the visual bias dominated, but the magnitude of this bias was reduced compared to unisensory conditions. Therefore, multisensory integration not only improves the

Biases in Visual, Auditory, and Audiovisual Perception of Space.

Directory of Open Access Journals (Sweden)

Brian Odegaard

2015-12-01

Full Text Available Localization of objects and events in the environment is critical for survival, as many perceptual and motor tasks rely on estimation of spatial location. Therefore, it seems reasonable to assume that spatial localizations should generally be accurate. Curiously, some previous studies have reported biases in visual and auditory localizations, but these studies have used small sample sizes and the results have been mixed. Therefore, it is not clear (1 if the reported biases in localization responses are real (or due to outliers, sampling bias, or other factors, and (2 whether these putative biases reflect a bias in sensory representations of space or a priori expectations (which may be due to the experimental setup, instructions, or distribution of stimuli. Here, to address these questions, a dataset of unprecedented size (obtained from 384 observers was analyzed to examine presence, direction, and magnitude of sensory biases, and quantitative computational modeling was used to probe the underlying mechanism(s driving these effects. Data revealed that, on average, observers were biased towards the center when localizing visual stimuli, and biased towards the periphery when localizing auditory stimuli. Moreover, quantitative analysis using a Bayesian Causal Inference framework suggests that while pre-existing spatial biases for central locations exert some influence, biases in the sensory representations of both visual and auditory space are necessary to fully explain the behavioral data. How are these opposing visual and auditory biases reconciled in conditions in which both auditory and visual stimuli are produced by a single event? Potentially, the bias in one modality could dominate, or the biases could interact/cancel out. The data revealed that when integration occurred in these conditions, the visual bias dominated, but the magnitude of this bias was reduced compared to unisensory conditions. Therefore, multisensory integration not only

Investigating vulnerability to eating disorders: biases in emotional processing.

Science.gov (United States)

Pringle, A; Harmer, C J; Cooper, M J

2010-04-01

Biases in emotional processing and cognitions about the self are thought to play a role in the maintenance of eating disorders (EDs). However, little is known about whether these difficulties exist pre-morbidly and how they might contribute to risk. Female dieters (n=82) completed a battery of tasks designed to assess the processing of social cues (facial emotion recognition), cognitions about the self [Self-Schema Processing Task (SSPT)] and ED-specific cognitions about eating, weight and shape (emotional Stroop). The 26-item Eating Attitudes Test (EAT-26; Garner et al. 1982) was used to assess subclinical ED symptoms; this was used as an index of vulnerability within this at-risk group. Regression analyses showed that biases in the processing of both neutral and angry faces were predictive of our measure of vulnerability (EAT-26). In the self-schema task, biases in the processing of negative self descriptors previously found to be common in EDs predicted vulnerability. Biases in the processing of shape-related words on the Stroop task were also predictive; however, these biases were more important in dieters who also displayed biases in the self-schema task. We were also able to demonstrate that these biases are specific and separable from more general negative biases that could be attributed to depressive symptoms. These results suggest that specific biases in the processing of social cues, cognitions about the self, and also about eating, weight and shape information, may be important in understanding risk and preventing relapse in EDs.

Bias During the Evaluation of Animal Studies?

Directory of Open Access Journals (Sweden)

Andrew Knight

2012-02-01

Full Text Available My recent book entitled The Costs and Benefits of Animal Experiments seeks to answer a key question within animal ethics, namely: is animal experimentation ethically justifiable? Or, more precisely, is it justifiable within the utilitarian cost:benefit framework that fundamentally underpins most regulations governing animal experimentation? To answer this question I reviewed more than 500 scientific publications describing animal studies, animal welfare impacts, and alternative research, toxicity testing and educational methodologies. To minimise bias I focused primarily on large-scale systematic reviews that had examined the human clinical and toxicological utility of animal studies. Despite this, Dr. Susanne Prankel recently reviewed my book in this journal, essentially accusing me of bias. However, she failed to provide any substantive evidence to refute my conclusions, let alone evidence of similar weight to that on which they are based. Those conclusions are, in fact, firmly based on utilitarian ethical reasoning, informed by scientific evidence of considerable strength, and I believe they are robust.

Bias During the Evaluation of Animal Studies?

Science.gov (United States)

Knight, Andrew

2012-02-23

My recent book entitled The Costs and Benefits of Animal Experiments seeks to answer a key question within animal ethics, namely: is animal experimentation ethically justifiable? Or, more precisely, is it justifiable within the utilitarian cost:benefit framework that fundamentally underpins most regulations governing animal experimentation? To answer this question I reviewed more than 500 scientific publications describing animal studies, animal welfare impacts, and alternative research, toxicity testing and educational methodologies. To minimise bias I focused primarily on large-scale systematic reviews that had examined the human clinical and toxicological utility of animal studies. Despite this, Dr. Susanne Prankel recently reviewed my book in this journal, essentially accusing me of bias. However, she failed to provide any substantive evidence to refute my conclusions, let alone evidence of similar weight to that on which they are based. Those conclusions are, in fact, firmly based on utilitarian ethical reasoning, informed by scientific evidence of considerable strength, and I believe they are robust.

Estimates of bias and uncertainty in recorded external dose

International Nuclear Information System (INIS)

Fix, J.J.; Gilbert, E.S.; Baumgartner, W.V.

1994-10-01

A study is underway to develop an approach to quantify bias and uncertainty in recorded dose estimates for workers at the Hanford Site based on personnel dosimeter results. This paper focuses on selected experimental studies conducted to better define response characteristics of Hanford dosimeters. The study is more extensive than the experimental studies presented in this paper and includes detailed consideration and evaluation of other sources of bias and uncertainty. Hanford worker dose estimates are used in epidemiologic studies of nuclear workers. A major objective of these studies is to provide a direct assessment of the carcinogenic risk of exposure to ionizing radiation at low doses and dose rates. Considerations of bias and uncertainty in the recorded dose estimates are important in the conduct of this work. The method developed for use with Hanford workers can be considered an elaboration of the approach used to quantify bias and uncertainty in estimated doses for personnel exposed to radiation as a result of atmospheric testing of nuclear weapons between 1945 and 1962. This approach was first developed by a National Research Council (NRC) committee examining uncertainty in recorded film badge doses during atmospheric tests (NRC 1989). It involved quantifying both bias and uncertainty from three sources (i.e., laboratory, radiological, and environmental) and then combining them to obtain an overall assessment. Sources of uncertainty have been evaluated for each of three specific Hanford dosimetry systems (i.e., the Hanford two-element film dosimeter, 1944-1956; the Hanford multi-element film dosimeter, 1957-1971; and the Hanford multi-element TLD, 1972-1993) used to estimate personnel dose throughout the history of Hanford operations. Laboratory, radiological, and environmental sources of bias and uncertainty have been estimated based on historical documentation and, for angular response, on selected laboratory measurements

A systematic review of context bias in invasion biology.

Directory of Open Access Journals (Sweden)

Robert J Warren

Full Text Available The language that scientists use to frame biological invasions may reveal inherent bias-including how data are interpreted. A frequent critique of invasion biology is the use of value-laden language that may indicate context bias. Here we use a systematic study of language and interpretation in papers drawn from invasion biology to evaluate whether there is a link between the framing of papers and the interpretation of results. We also examine any trends in context bias in biological invasion research. We examined 651 peer-reviewed invasive species competition studies and implemented a rigorous systematic review to examine bias in the presentation and interpretation of native and invasive competition in invasion biology. We predicted that bias in the presentation of invasive species is increasing, as suggested by several authors, and that bias against invasive species would result in misinterpreting their competitive dominance in correlational observational studies compared to causative experimental studies. We indeed found evidence of bias in the presentation and interpretation of invasive species research; authors often introduced research with invasive species in a negative context and study results were interpreted against invasive species more in correlational studies. However, we also found a distinct decrease in those biases since the mid-2000s. Given that there have been several waves of criticism from scientists both inside and outside invasion biology, our evidence suggests that the subdiscipline has somewhat self-corrected apparent biases.

A systematic review of context bias in invasion biology.

Science.gov (United States)

Warren, Robert J; King, Joshua R; Tarsa, Charlene; Haas, Brian; Henderson, Jeremy

2017-01-01

The language that scientists use to frame biological invasions may reveal inherent bias-including how data are interpreted. A frequent critique of invasion biology is the use of value-laden language that may indicate context bias. Here we use a systematic study of language and interpretation in papers drawn from invasion biology to evaluate whether there is a link between the framing of papers and the interpretation of results. We also examine any trends in context bias in biological invasion research. We examined 651 peer-reviewed invasive species competition studies and implemented a rigorous systematic review to examine bias in the presentation and interpretation of native and invasive competition in invasion biology. We predicted that bias in the presentation of invasive species is increasing, as suggested by several authors, and that bias against invasive species would result in misinterpreting their competitive dominance in correlational observational studies compared to causative experimental studies. We indeed found evidence of bias in the presentation and interpretation of invasive species research; authors often introduced research with invasive species in a negative context and study results were interpreted against invasive species more in correlational studies. However, we also found a distinct decrease in those biases since the mid-2000s. Given that there have been several waves of criticism from scientists both inside and outside invasion biology, our evidence suggests that the subdiscipline has somewhat self-corrected apparent biases.

Reduction of density-modification bias by β correction

International Nuclear Information System (INIS)

Skubák, Pavol; Pannu, Navraj S.

2011-01-01

A cross-validation-based method for bias reduction in ‘classical’ iterative density modification of experimental X-ray crystallography maps provides significantly more accurate phase-quality estimates and leads to improved automated model building. Density modification often suffers from an overestimation of phase quality, as seen by escalated figures of merit. A new cross-validation-based method to address this estimation bias by applying a bias-correction parameter ‘β’ to maximum-likelihood phase-combination functions is proposed. In tests on over 100 single-wavelength anomalous diffraction data sets, the method is shown to produce much more reliable figures of merit and improved electron-density maps. Furthermore, significantly better results are obtained in automated model building iterated with phased refinement using the more accurate phase probability parameters from density modification

Relationship between the DC Bias and Debye Length in a Complex Plasma

OpenAIRE

Kong, Jie; Reyes, Jorge C.; Creel, James; Hyde, Truell

2007-01-01

The levitation height of a dust particle layer within a RF discharge plasma sheath is known to be related to the DC bias, the background pressure, and the Debye length. In this paper, a new experimental technique for measurement of the Debye length is introduced. This technique is based on the relationship between an externally applied DC bias and the particle levitation height and shows that under appropriate conditions, the addition of an externally applied DC bias provides a mechanism for ...

Experimenter Confirmation Bias and the Correction of Science Misconceptions

Science.gov (United States)

Allen, Michael; Coole, Hilary

2012-06-01

This paper describes a randomised educational experiment ( n = 47) that examined two different teaching methods and compared their effectiveness at correcting one science misconception using a sample of trainee primary school teachers. The treatment was designed to promote engagement with the scientific concept by eliciting emotional responses from learners that were triggered by their own confirmation biases. The treatment group showed superior learning gains to control at post-test immediately after the lesson, although benefits had dissipated after 6 weeks. Findings are discussed with reference to the conceptual change paradigm and to the importance of feeling emotion during a learning experience, having implications for the teaching of pedagogies to adults that have been previously shown to be successful with children.

Reasoning, biases and dual processes: The lasting impact of Wason (1960).

Science.gov (United States)

Evans, Jonathan St B T

2016-10-01

Wason (1960) published a relatively short experimental paper, in which he introduced the 2-4-6 problem as a test of inductive reasoning. This paper became one of the most highly cited to be published in the Quarterly Journal of Experimental Psychology and is significant for a number of reasons. First, the 2-4-6 task itself was ingenious and yielded evidence of error and bias in the intelligent participants who attempted it. Research on the 2-4-6 problem continues to the present day. More importantly, it was Wason's first paper on reasoning and one which made strong claims for bias and irrationality in a period dominated by rationalist writers like Piaget. It set in motion the study of cognitive biases in thinking and reasoning, well before the start of Tversky and Kahneman's famous heuristics and biases research programme. I also show here something for which Wason has received insufficient credit. It was Wason's work on this task and his later studies of his four card selection task that led to the first development of the dual process theory of reasoning which is so dominant in the current literature on the topic more than half a century later.

Why Reject Creative Ideas? Fear as a Driver of Implicit Bias against Creativity

Science.gov (United States)

Lee, Young Soo; Chang, Jae Yoon; Choi, Jin Nam

2017-01-01

Biases against creativity seem to be activated when people are motivated to reduce uncertainty. Drawing on the appraisal model of emotion, this study tested whether and how emotions with varying levels of uncertainty appraisals affect biases against creativity. This experimental study showed that fear, characterized by a high-uncertainty…

Apparent directional selection by biased pleiotropic mutation.

Science.gov (United States)

Tanaka, Yoshinari

2010-07-01

Pleiotropic effects of deleterious mutations are considered to be among the factors responsible for genetic constraints on evolution by long-term directional selection acting on a quantitative trait. If pleiotropic phenotypic effects are biased in a particular direction, mutations generate apparent directional selection, which refers to the covariance between fitness and the trait owing to a linear association between the number of mutations possessed by individuals and the genotypic values of the trait. The present analysis has shown how the equilibrium mean value of the trait is determined by a balance between directional selection and biased pleiotropic mutations. Assuming that genes act additively both on the trait and on fitness, the total variance-standardized directional selection gradient was decomposed into apparent and true components. Experimental data on mutation bias from the bristle traits of Drosophila and life history traits of Daphnia suggest that apparent selection explains a small but significant fraction of directional selection pressure that is observed in nature; the data suggest that changes induced in a trait by biased pleiotropic mutation (i.e., by apparent directional selection) are easily compensated for by (true) directional selection.

Strong mechanically induced effects in DC current-biased suspended Josephson junctions

Science.gov (United States)

McDermott, Thomas; Deng, Hai-Yao; Isacsson, Andreas; Mariani, Eros

2018-01-01

Superconductivity is a result of quantum coherence at macroscopic scales. Two superconductors separated by a metallic or insulating weak link exhibit the AC Josephson effect: the conversion of a DC voltage bias into an AC supercurrent. This current may be used to activate mechanical oscillations in a suspended weak link. As the DC-voltage bias condition is remarkably difficult to achieve in experiments, here we analyze theoretically how the Josephson effect can be exploited to activate and detect mechanical oscillations in the experimentally relevant condition with purely DC current bias. We unveil how changing the strength of the electromechanical coupling results in two qualitatively different regimes showing dramatic effects of the oscillations on the DC-voltage characteristic of the device. These include the appearance of Shapiro-type plateaus for weak coupling and a sudden mechanically induced retrapping for strong coupling. Our predictions, measurable in state-of-the-art experimental setups, allow the determination of the frequency and quality factor of the resonator using DC only techniques.

VOX POPULI: Automatic Generation of Biased Video Sequences

NARCIS (Netherlands)

S. Bocconi; F.-M. Nack (Frank)

2004-01-01

textabstractWe describe our experimental rhetoric engine Vox Populi that generates biased video-sequences from a repository of video interviews and other related audio-visual web sources. Users are thus able to explore their own opinions on controversial topics covered by the repository. The

VOX POPULI: automatic generation of biased video sequences

NARCIS (Netherlands)

S. Bocconi; F.-M. Nack (Frank)

2004-01-01

textabstractWe describe our experimental rhetoric engine Vox Populi that generates biased video-sequences from a repository of video interviews and other related audio-visual web sources. Users are thus able to explore their own opinions on controversial topics covered by the repository. The

Coupled bias-variance tradeoff for cross-pose face recognition.

Science.gov (United States)

Li, Annan; Shan, Shiguang; Gao, Wen

2012-01-01

Subspace-based face representation can be looked as a regression problem. From this viewpoint, we first revisited the problem of recognizing faces across pose differences, which is a bottleneck in face recognition. Then, we propose a new approach for cross-pose face recognition using a regressor with a coupled bias-variance tradeoff. We found that striking a coupled balance between bias and variance in regression for different poses could improve the regressor-based cross-pose face representation, i.e., the regressor can be more stable against a pose difference. With the basic idea, ridge regression and lasso regression are explored. Experimental results on CMU PIE, the FERET, and the Multi-PIE face databases show that the proposed bias-variance tradeoff can achieve considerable reinforcement in recognition performance.

Risk of Bias in Reports of In Vivo Research: A Focus for Improvement.

Directory of Open Access Journals (Sweden)

Malcolm R Macleod

2015-10-01

Full Text Available The reliability of experimental findings depends on the rigour of experimental design. Here we show limited reporting of measures to reduce the risk of bias in a random sample of life sciences publications, significantly lower reporting of randomisation in work published in journals of high impact, and very limited reporting of measures to reduce the risk of bias in publications from leading United Kingdom institutions. Ascertainment of differences between institutions might serve both as a measure of research quality and as a tool for institutional efforts to improve research quality.

A "Scientific Diversity" Intervention to Reduce Gender Bias in a Sample of Life Scientists

Science.gov (United States)

Moss-Racusin, Corinne A.; van der Toorn, Jojanneke; Dovidio, John F.; Brescoll, Victoria L.; Graham, Mark J.; Handelsman, Jo

2016-01-01

Mounting experimental evidence suggests that subtle gender biases favoring men contribute to the underrepresentation of women in science, technology, engineering, and mathematics (STEM), including many subfields of the life sciences. However, there are relatively few evaluations of diversity interventions designed to reduce gender biases within…

Does napping enhance the effects of Cognitive Bias Modification-Appraisal training? An experimental study.

Directory of Open Access Journals (Sweden)

Marcella L Woud

Full Text Available Posttraumatic Stress Disorder (PTSD is characterised by dysfunctional appraisals of the trauma and its consequences including one's own symptoms. Experimental studies have shown that Cognitive Bias Modification-Appraisal (CBM-App training can reduce dysfunctional interpretations and analog trauma symptoms. One important question is how to enhance the effects of CBM-App. Following work suggesting that sleep has beneficial effects on consolidation processes and can thus improve learning, the present study investigated whether a brief period of sleep (i.e., a nap enhances the effects of CBM-App. All participants watched a stressful movie as an analogue trauma induction. After that, participants received either positive or negative CBM-App training. Within each training, half of the participants then had a 90-minute nap or watched a neutral movie. Results showed that the CBM training induced training-congruent appraisals. Sleep did not enhance this effect. Participants who slept, however, experienced fewer intrusive memories of the analogue trauma, but this effect was independent of the CBM condition. These results provide valuable information about the effects of sleep during a 90-minute nap period on encoding of analogue trauma and emotional learning in the context of appraisal, and highlight the importance of sleep as a focus for continued research.

Does napping enhance the effects of Cognitive Bias Modification-Appraisal training? An experimental study.

Science.gov (United States)

Woud, Marcella L; Cwik, Jan C; Blackwell, Simon E; Kleim, Birgit; Holmes, Emily A; Adolph, Dirk; Zhang, Hui; Margraf, Jürgen

2018-01-01

Posttraumatic Stress Disorder (PTSD) is characterised by dysfunctional appraisals of the trauma and its consequences including one's own symptoms. Experimental studies have shown that Cognitive Bias Modification-Appraisal (CBM-App) training can reduce dysfunctional interpretations and analog trauma symptoms. One important question is how to enhance the effects of CBM-App. Following work suggesting that sleep has beneficial effects on consolidation processes and can thus improve learning, the present study investigated whether a brief period of sleep (i.e., a nap) enhances the effects of CBM-App. All participants watched a stressful movie as an analogue trauma induction. After that, participants received either positive or negative CBM-App training. Within each training, half of the participants then had a 90-minute nap or watched a neutral movie. Results showed that the CBM training induced training-congruent appraisals. Sleep did not enhance this effect. Participants who slept, however, experienced fewer intrusive memories of the analogue trauma, but this effect was independent of the CBM condition. These results provide valuable information about the effects of sleep during a 90-minute nap period on encoding of analogue trauma and emotional learning in the context of appraisal, and highlight the importance of sleep as a focus for continued research.

Addressing Unconscious Bias: Steps toward an Inclusive Scientific Culture

Science.gov (United States)

Stewart, Abigail

2011-01-01

In this talk I will outline the nature of unconscious bias, as it operates to exclude or marginalize some participants in the scientific community. I will show how bias results from non-conscious expectations about certain groups of people, including scientists and astronomers. I will outline scientific research in psychology, sociology and economics that has identified the impact these expectations have on interpersonal judgments that are at the heart of assessment of individuals' qualifications. This research helps us understand not only how bias operates within a single instance of evaluation, but how evaluation bias can accumulate over a career if not checked, creating an appearance of confirmation of biased expectations. Some research has focused on how best to interrupt and mitigate unconscious bias, and many institutions--including the University of Michigan--have identified strategic interventions at key points of institutional decision-making (particularly hiring, annual review, and promotion) that can make a difference. The NSF ADVANCE Institutional Transformation program encouraged institutions to draw on the social science literature to create experimental approaches to addressing unconscious bias. I will outline four approaches to intervention that have arisen through the ADVANCE program: (1) systematic education that increases awareness among decisionmakers of how evaluation bias operates; (2) development of practices that mitigate the operation of bias even when it is out of conscious awareness; (3) creation of institutional policies that routinize and sanction these practices; and (4) holding leaders accountable for these implementation of these new practices and policies. Although I will focus on ways to address unconscious bias within scientific institutions (colleges and universities, laboratories and research centers, etc.), I will close by considering how scientific organizations can address unconscious bias and contribute to creating an

Role of the antiferromagnetic bulk spins in exchange bias

Energy Technology Data Exchange (ETDEWEB)

Schuller, Ivan K. [Center for Advanced Nanoscience and Physics Department, University of California San Diego, La Jolla, CA 92093 (United States); Morales, Rafael, E-mail: rafael.morales@ehu.es [Department of Chemical-Physics & BCMaterials, University of the Basque Country UPV/EHU (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Batlle, Xavier [Departament Física Fonamental and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, c/ Martí i Franqués s/n, 08028 Barcelona, Catalonia (Spain); Nowak, Ulrich [Department of Physics, University of Konstanz, 78464 Konstanz (Germany); Güntherodt, Gernot [Physics Institute (IIA), RWTH Aachen University, Campus RWTH-Melaten, 52074 Aachen (Germany)

2016-10-15

This “Critical Focused Issue” presents a brief review of experiments and models which describe the origin of exchange bias in epitaxial or textured ferromagnetic/antiferromagnetic bilayers. Evidence is presented which clearly indicates that inner, uncompensated, pinned moments in the bulk of the antiferromagnet (AFM) play a very important role in setting the magnitude of the exchange bias. A critical evaluation of the extensive literature in the field indicates that it is useful to think of this bulk, pinned uncompensated moments as a new type of a ferromagnet which has a low total moment, an ordering temperature given by the AFM Néel temperature, with parallel aligned moments randomly distributed on the regular AFM lattice. - Highlights: • We address the role of bulk antiferromagnetic spins in the exchange bias phenomenon. • Significant experiments on how bulk AFM spins determine exchange bias are highlighted. • We explain the model that accounts for experimental results.

Role of the antiferromagnetic bulk spins in exchange bias

International Nuclear Information System (INIS)

Schuller, Ivan K.; Morales, Rafael; Batlle, Xavier; Nowak, Ulrich; Güntherodt, Gernot

2016-01-01

This “Critical Focused Issue” presents a brief review of experiments and models which describe the origin of exchange bias in epitaxial or textured ferromagnetic/antiferromagnetic bilayers. Evidence is presented which clearly indicates that inner, uncompensated, pinned moments in the bulk of the antiferromagnet (AFM) play a very important role in setting the magnitude of the exchange bias. A critical evaluation of the extensive literature in the field indicates that it is useful to think of this bulk, pinned uncompensated moments as a new type of a ferromagnet which has a low total moment, an ordering temperature given by the AFM Néel temperature, with parallel aligned moments randomly distributed on the regular AFM lattice. - Highlights: • We address the role of bulk antiferromagnetic spins in the exchange bias phenomenon. • Significant experiments on how bulk AFM spins determine exchange bias are highlighted. • We explain the model that accounts for experimental results.

Cognitive bias in forensic anthropology: visual assessment of skeletal remains is susceptible to confirmation bias.

Science.gov (United States)

Nakhaeizadeh, Sherry; Dror, Itiel E; Morgan, Ruth M

2014-05-01

An experimental study was designed to examine cognitive biases within forensic anthropological non-metric methods in assessing sex, ancestry and age at death. To investigate examiner interpretation, forty-one non-novice participants were semi randomly divided into three groups. Prior to conducting the assessment of the skeletal remains, two of the groups were given different extraneous contextual information regarding the sex, ancestry and age at death of the individual. The third group acted as a control group with no extraneous contextual information. The experiment was designed to investigate if the interpretation and conclusions of the skeletal remains would differ amongst participants within the three groups, and to assess whether the examiners would confirm or disagree with the given extraneous context when establishing a biological profile. The results revealed a significant biasing effect within the three groups, demonstrating a strong confirmation bias in the assessment of sex, ancestry and age at death. In assessment of sex, 31% of the participants in the control group concluded that the skeleton remains were male. In contrast, in the group that received contextual information that the remains were male, 72% concluded that the remains were male, and in the participant group where the context was that the remains were of a female, 0% of the participants concluded that the remains were male. Comparable results showing bias were found in assessing ancestry and age at death. These data demonstrate that cognitive bias can impact forensic anthropological non-metric methods on skeletal remains and affects the interpretation and conclusions of the forensic scientists. This empirical study is a step in establishing an evidence base approach for dealing with cognitive issues in forensic anthropological assessments, so as to enhance this valuable forensic science discipline. Copyright © 2013 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights

Calibration biases in logical reasoning tasks

Directory of Open Access Journals (Sweden)

Guillermo Macbeth

2013-08-01

Full Text Available The aim of this contribution is to present an experimental study about calibration in deductive reasoning tasks. Calibration is defi ned as the empirical convergence or divergence between the objective and the subjective success. The underconfi dence bias is understood as the dominance of the former over the latter. The hypothesis of this study states that the form of the propositions presented in the experiment is critical for calibration phenomena. Affi rmative and negative propositions are distinguished in their cognitive processing. Results suggests that monotonous compound propositions are prone to underconfi dence. An heuristic approach to this phenomenon is proposed. The activation of a monotony heuristic would produce an illusion of simplicity that generates the calibration bias. These evidence is analysed in the context of the metacognitive modeling of calibration phenomena.

Evidence of Cognitive Bias in Decision Making Around Implantable-Cardioverter Defibrillators: A Qualitative Framework Analysis.

Science.gov (United States)

Matlock, Daniel D; Jones, Jacqueline; Nowels, Carolyn T; Jenkins, Amy; Allen, Larry A; Kutner, Jean S

2017-11-01

Studies have demonstrated that patients with primary prevention implantable cardioverter-defibrillators (ICDs) often misunderstand the ICD. Advances in behavioral economics demonstrate that some misunderstandings may be due to cognitive biases. We aimed to explore the influence of cognitive bias on ICD decision making. We used a qualitative framework analysis including 9 cognitive biases: affect heuristic, affective forecasting, anchoring, availability, default effects, halo effects, optimism bias, framing effects, and state dependence. We interviewed 48 patients from 4 settings in Denver. The majority were male (n = 32). Overall median age was 61 years. We found frequent evidence for framing, default, and halo effects; some evidence of optimism bias, affect heuristic, state dependence, anchoring and availability bias; and little or no evidence of affective forecasting. Framing effects were apparent in overestimation of benefits and downplaying or omitting potential harms. We found evidence of cognitive bias in decision making for ICD implantation. The majority of these biases appeared to encourage ICD treatment. Published by Elsevier Inc.

Theoretical study on new bias factor methods to effectively use critical experiments for improvement of prediction accuracy of neutronic characteristics

International Nuclear Information System (INIS)

Kugo, Teruhiko; Mori, Takamasa; Takeda, Toshikazu

2007-01-01

Extended bias factor methods are proposed with two new concepts, the LC method and the PE method, in order to effectively use critical experiments and to enhance the applicability of the bias factor method for the improvement of the prediction accuracy of neutronic characteristics of a target core. Both methods utilize a number of critical experimental results and produce a semifictitious experimental value with them. The LC and PE methods define the semifictitious experimental values by a linear combination of experimental values and the product of exponentiated experimental values, respectively, and the corresponding semifictitious calculation values by those of calculation values. A bias factor is defined by the ratio of the semifictitious experimental value to the semifictitious calculation value in both methods. We formulate how to determine weights for the LC method and exponents for the PE method in order to minimize the variance of the design prediction value obtained by multiplying the design calculation value by the bias factor. From a theoretical comparison of these new methods with the conventional method which utilizes a single experimental result and the generalized bias factor method which was previously proposed to utilize a number of experimental results, it is concluded that the PE method is the most useful method for improving the prediction accuracy. The main advantages of the PE method are summarized as follows. The prediction accuracy is necessarily improved compared with the design calculation value even when experimental results include large experimental errors. This is a special feature that the other methods do not have. The prediction accuracy is most effectively improved by utilizing all the experimental results. From these facts, it can be said that the PE method effectively utilizes all the experimental results and has a possibility to make a full-scale-mockup experiment unnecessary with the use of existing and future benchmark

Two biased estimation techniques in linear regression: Application to aircraft

Science.gov (United States)

Klein, Vladislav

1988-01-01

Several ways for detection and assessment of collinearity in measured data are discussed. Because data collinearity usually results in poor least squares estimates, two estimation techniques which can limit a damaging effect of collinearity are presented. These two techniques, the principal components regression and mixed estimation, belong to a class of biased estimation techniques. Detection and assessment of data collinearity and the two biased estimation techniques are demonstrated in two examples using flight test data from longitudinal maneuvers of an experimental aircraft. The eigensystem analysis and parameter variance decomposition appeared to be a promising tool for collinearity evaluation. The biased estimators had far better accuracy than the results from the ordinary least squares technique.

Sympathetic bias.

Science.gov (United States)

Levy, David M; Peart, Sandra J

2008-06-01

We wish to deal with investigator bias in a statistical context. We sketch how a textbook solution to the problem of "outliers" which avoids one sort of investigator bias, creates the temptation for another sort. We write down a model of the approbation seeking statistician who is tempted by sympathy for client to violate the disciplinary standards. We give a simple account of one context in which we might expect investigator bias to flourish. Finally, we offer tentative suggestions to deal with the problem of investigator bias which follow from our account. As we have given a very sparse and stylized account of investigator bias, we ask what might be done to overcome this limitation.

Exchange bias of patterned systems: Model and numerical simulation

International Nuclear Information System (INIS)

Garcia, Griselda; Kiwi, Miguel; Mejia-Lopez, Jose; Ramirez, Ricardo

2010-01-01

The magnitude of the exchange bias field of patterned systems exhibits a notable increase in relation to the usual bilayer systems, where a continuous ferromagnetic film is deposited on an antiferromagnet insulator. Here we develop a model, and implement a Monte Carlo calculation, to interpret the experimental observations which is consistent with experimental results, on the basis of assuming a small fraction of spins pinned ferromagnetically in the antiferromagnetic interface layer.

Bias modification training can alter approach bias and chocolate consumption.

Science.gov (United States)

Schumacher, Sophie E; Kemps, Eva; Tiggemann, Marika

2016-01-01

Recent evidence has demonstrated that bias modification training has potential to reduce cognitive biases for attractive targets and affect health behaviours. The present study investigated whether cognitive bias modification training could be applied to reduce approach bias for chocolate and affect subsequent chocolate consumption. A sample of 120 women (18-27 years) were randomly assigned to an approach-chocolate condition or avoid-chocolate condition, in which they were trained to approach or avoid pictorial chocolate stimuli, respectively. Training had the predicted effect on approach bias, such that participants trained to approach chocolate demonstrated an increased approach bias to chocolate stimuli whereas participants trained to avoid such stimuli showed a reduced bias. Further, participants trained to avoid chocolate ate significantly less of a chocolate muffin in a subsequent taste test than participants trained to approach chocolate. Theoretically, results provide support for the dual process model's conceptualisation of consumption as being driven by implicit processes such as approach bias. In practice, approach bias modification may be a useful component of interventions designed to curb the consumption of unhealthy foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sex bias in experimental immune-mediated, drug-induced liver injury in BALB/c mice: suggested roles for Tregs, estrogen, and IL-6.

Directory of Open Access Journals (Sweden)

Joonhee Cho

Full Text Available Immune-mediated, drug-induced liver injury (DILI triggered by drug haptens is more prevalent in women than in men. However, mechanisms responsible for this sex bias are not clear. Immune regulation by CD4+CD25+FoxP3+ regulatory T-cells (Tregs and 17β-estradiol is crucial in the pathogenesis of sex bias in cancer and autoimmunity. Therefore, we investigated their role in a mouse model of immune-mediated DILI.To model DILI, we immunized BALB/c, BALB/cBy, IL-6-deficient, and castrated BALB/c mice with trifluoroacetyl chloride-haptenated liver proteins. We then measured degree of hepatitis, cytokines, antibodies, and Treg and splenocyte function.BALB/c females developed more severe hepatitis (p<0.01 and produced more pro-inflammatory hepatic cytokines and antibodies (p<0.05 than did males. Castrated males developed more severe hepatitis than did intact males (p<0.001 and females (p<0.05. Splenocytes cultured from female mice exhibited fewer Tregs (p<0.01 and higher IL-1β (p<0.01 and IL-6 (p<0.05 than did those from males. However, Treg function did not differ by sex, as evidenced by absence of sex bias in programmed death receptor-1 and responses to IL-6, anti-IL-10, anti-CD3, and anti-CD28. Diminished hepatitis in IL-6-deficient, anti-IL-6 receptor α-treated, ovariectomized, or male mice; undetectable IL-6 levels in splenocyte supernatants from ovariectomized and male mice; elevated splenic IL-6 and serum estrogen levels in castrated male mice, and IL-6 induction by 17β-estradiol in splenocytes from naïve female mice (p<0.05 suggested that 17β-estradiol may enhance sex bias through IL-6 induction, which subsequently discourages Treg survival. Treg transfer from naïve female mice to those with DILI reduced hepatitis severity and hepatic IL-6.17β-estradiol and IL-6 may act synergistically to promote sex bias in experimental DILI by reducing Tregs. Modulating Treg numbers may provide a therapeutic approach to DILI.

Visual search attentional bias modification reduced social phobia in adolescents.

Science.gov (United States)

De Voogd, E L; Wiers, R W; Prins, P J M; Salemink, E

2014-06-01

An attentional bias for negative information plays an important role in the development and maintenance of (social) anxiety and depression, which are highly prevalent in adolescence. Attention Bias Modification (ABM) might be an interesting tool in the prevention of emotional disorders. The current study investigated whether visual search ABM might affect attentional bias and emotional functioning in adolescents. A visual search task was used as a training paradigm; participants (n = 16 adolescents, aged 13-16) had to repeatedly identify the only smiling face in a 4 × 4 matrix of negative emotional faces, while participants in the control condition (n = 16) were randomly allocated to one of three placebo training versions. An assessment version of the task was developed to directly test whether attentional bias changed due to the training. Self-reported anxiety and depressive symptoms and self-esteem were measured pre- and post-training. After two sessions of training, the ABM group showed a significant decrease in attentional bias for negative information and self-reported social phobia, while the control group did not. There were no effects of training on depressive mood or self-esteem. No correlation between attentional bias and social phobia was found, which raises questions about the validity of the attentional bias assessment task. Also, the small sample size precludes strong conclusions. Visual search ABM might be beneficial in changing attentional bias and social phobia in adolescents, but further research with larger sample sizes and longer follow-up is needed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Workplace ageism: discovering hidden bias.

Science.gov (United States)

Malinen, Sanna; Johnston, Lucy

2013-01-01

BACKGROUND/STUDY CONTEXT: Research largely shows no performance differences between older and younger employees, or that older workers even outperform younger employees, yet negative attitudes towards older workers can underpin discrimination. Unfortunately, traditional "explicit" techniques for assessing attitudes (i.e., self-report measures) have serious drawbacks. Therefore, using an approach that is novel to organizational contexts, the authors supplemented explicit with implicit (indirect) measures of attitudes towards older workers, and examined the malleability of both. This research consists of two studies. The authors measured self-report (explicit) attitudes towards older and younger workers with a survey, and implicit attitudes with a reaction-time-based measure of implicit associations. In addition, to test whether attitudes were malleable, the authors measured attitudes before and after a mental imagery intervention, where the authors asked participants in the experimental group to imagine respected and valued older workers from their surroundings. Negative, stable implicit attitudes towards older workers emerged in two studies. Conversely, explicit attitudes showed no age bias and were more susceptible to change intervention, such that attitudes became more positive towards older workers following the experimental manipulation. This research demonstrates the unconscious nature of bias against older workers, and highlights the utility of implicit attitude measures in the context of the workplace. In the current era of aging workforce and skill shortages, implicit measures may be necessary to illuminate hidden workplace ageism.

Combination of biased forecasts: Bias correction or bias based weights?

OpenAIRE

Wenzel, Thomas

1999-01-01

Most of the literature on combination of forecasts deals with the assumption of unbiased individual forecasts. Here, we consider the case of biased forecasts and discuss two different combination techniques resulting in an unbiased forecast. On the one hand we correct the individual forecasts, and on the other we calculate bias based weights. A simulation study gives some insight in the situations where we should use the different methods.

Sodium bicarbonate as prevention of metabolic acidosis in sheep submitted to experimental ruminal acidosis

Directory of Open Access Journals (Sweden)

Luciane M. Laskoski

2014-09-01

Full Text Available The aim of this study was to evaluate the preventive effect of sodium bicarbonate on systemic acidosis due to ruminal acidosis, which was induced by ingestion of concentrate after prolonged fasting. Fourteen sheep were divided into three experimental groups: control group (Cg, with four sheep, submitted to fasting without development of ruminal acidosis; no-treated group (NTg, with five sheep with rumen acidosis without preventive treatment; and treated group (Tg, with five sheep with rumen acidosis and preventively treated with sodium bicarbonate. Assessments of ruminal pH and arterial hemogasometry were performed for 48 hours after ingestion of the concentrate. There was a reduction in the ruminal pH in all groups, whereas the Cg showed a reduction only after 24 hours. A reduction in the arterial pH, bicarbonate and base excess in all groups was also noted, indicating systemic metabolic acidosis, but the NTg presented the greatest alteration. It is concluded that sodium bicarbonate prevents systemic metabolic acidosis, reducing its severity in sheep subjected to ruminal acidosis.

Spatial Bias in Field-Estimated Unsaturated Hydraulic Properties

Energy Technology Data Exchange (ETDEWEB)

HOLT,ROBERT M.; WILSON,JOHN L.; GLASS JR.,ROBERT J.

2000-12-21

Hydraulic property measurements often rely on non-linear inversion models whose errors vary between samples. In non-linear physical measurement systems, bias can be directly quantified and removed using calibration standards. In hydrologic systems, field calibration is often infeasible and bias must be quantified indirectly. We use a Monte Carlo error analysis to indirectly quantify spatial bias in the saturated hydraulic conductivity, K{sub s}, and the exponential relative permeability parameter, {alpha}, estimated using a tension infiltrometer. Two types of observation error are considered, along with one inversion-model error resulting from poor contact between the instrument and the medium. Estimates of spatial statistics, including the mean, variance, and variogram-model parameters, show significant bias across a parameter space representative of poorly- to well-sorted silty sand to very coarse sand. When only observation errors are present, spatial statistics for both parameters are best estimated in materials with high hydraulic conductivity, like very coarse sand. When simple contact errors are included, the nature of the bias changes dramatically. Spatial statistics are poorly estimated, even in highly conductive materials. Conditions that permit accurate estimation of the statistics for one of the parameters prevent accurate estimation for the other; accurate regions for the two parameters do not overlap in parameter space. False cross-correlation between estimated parameters is created because estimates of K{sub s} also depend on estimates of {alpha} and both parameters are estimated from the same data.

Estimation bias and bias correction in reduced rank autoregressions

DEFF Research Database (Denmark)

Nielsen, Heino Bohn

2017-01-01

This paper characterizes the finite-sample bias of the maximum likelihood estimator (MLE) in a reduced rank vector autoregression and suggests two simulation-based bias corrections. One is a simple bootstrap implementation that approximates the bias at the MLE. The other is an iterative root...

A scanning tunneling microscope break junction method with continuous bias modulation.

Science.gov (United States)

Beall, Edward; Yin, Xing; Waldeck, David H; Wierzbinski, Emil

2015-09-28

Single molecule conductance measurements on 1,8-octanedithiol were performed using the scanning tunneling microscope break junction method with an externally controlled modulation of the bias voltage. Application of an AC voltage is shown to improve the signal to noise ratio of low current (low conductance) measurements as compared to the DC bias method. The experimental results show that the current response of the molecule(s) trapped in the junction and the solvent media to the bias modulation can be qualitatively different. A model RC circuit which accommodates both the molecule and the solvent is proposed to analyze the data and extract a conductance for the molecule.

Examiner Expectancy and Bias as a Function of the Referral Process in Cognitive Assessment

Science.gov (United States)

Saunders, Bruce T.; Vitro, Frank T.

1971-01-01

The results of the present study suggest that clinical cognitive assessment is not influenced by examiner bias as in experimental or nonclinical assessment. A bias effect was not observed as a result of the referral process. The halo effect demonstrated in previous studies was not observed in this study. (Author/BY)

Effects of biases in domain wall network evolution. II. Quantitative analysis

Science.gov (United States)

Correia, J. R. C. C. C.; Leite, I. S. C. R.; Martins, C. J. A. P.

2018-04-01

Domain walls form at phase transitions which break discrete symmetries. In a cosmological context, they often overclose the Universe (contrary to observational evidence), although one may prevent this by introducing biases or forcing anisotropic evolution of the walls. In a previous work [Correia et al., Phys. Rev. D 90, 023521 (2014), 10.1103/PhysRevD.90.023521], we numerically studied the evolution of various types of biased domain wall networks in the early Universe, confirming that anisotropic networks ultimately reach scaling while those with a biased potential or biased initial conditions decay. We also found that the analytic decay law obtained by Hindmarsh was in good agreement with simulations of biased potentials, but not of biased initial conditions, and suggested that the difference was related to the Gaussian approximation underlying the analytic law. Here, we extend our previous work in several ways. For the cases of biased potential and biased initial conditions, we study in detail the field distributions in the simulations, confirming that the validity (or not) of the Gaussian approximation is the key difference between the two cases. For anisotropic walls, we carry out a more extensive set of numerical simulations and compare them to the canonical velocity-dependent one-scale model for domain walls, finding that the model accurately predicts the linear scaling regime after isotropization. Overall, our analysis provides a quantitative description of the cosmological evolution of these networks.

Numerical modelling of pump limiter biasing on TEXTOR-94 and Tore Supra

International Nuclear Information System (INIS)

Gerhauser, H.; Claassen, H.A.; Mank, G.; Zagorski, R.; Loarer, T.; Gunn, J.; Boucher, C.

2002-01-01

The two-dimensional multifluid code TECXY has been used to model the biasing (with respect to the first wall) of the toroidal belt limiter ALT-II on the tokamak TEXTOR-94 and of the new toroidal pump limiter being installed on Tore Supra tokamak in the framework of the CIEL project. It is well known that the edge flow pattern can be influenced by the poloidal electric drifts from imposing radial electric fields. The modelling with TECXY introduces imprinted bias currents in the scrape-off layer (SOL) for the case of negative (limiter) biasing, and imprinted bias potentials for the case of positive biasing. This allowed us to simulate sufficiently well the experimental I-V characteristics for either biasing of ALT-II and also reproduced the essential features and trends of the observed plasma profiles in the SOL of TEXTOR-94. For negative biasing a moderate improvement of the pumping exhaust efficiency can be achieved in the case of TEXTOR. For Tore Supra, however, only a negligible improvement of the limiter performance with biasing can be predicted, which is explained by the relatively weak drift flows in Tore Supra. (author)

Categorisation salience and ingroup bias: the buffering role of a multicultural ideology.

Science.gov (United States)

Costa-Lopes, Rui; Pereira, Cícero Roberto; Judd, Charles M

2014-12-01

The current work sought to test the moderating role of a multicultural ideology on the relationship between categorisation salience and ingroup bias. Accordingly, in one experimental study, we manipulated categorisation salience and the accessibility of a multicultural ideology, and measured intergroup attitudes. Results show that categorisation salience only leads to ingroup bias when a multiculturalism (MC) ideology is not made salient. Thus, MC ideology attenuates the negative effects of categorisation salience on ingroup bias. These results pertain to social psychology in general showing that the cognitive processes should be construed within the framework of ideological contexts. © 2014 International Union of Psychological Science.

Reporting bias in medical research - a narrative review

Directory of Open Access Journals (Sweden)

Kölsch Heike

2010-04-01

Full Text Available Abstract Reporting bias represents a major problem in the assessment of health care interventions. Several prominent cases have been described in the literature, for example, in the reporting of trials of antidepressants, Class I anti-arrhythmic drugs, and selective COX-2 inhibitors. The aim of this narrative review is to gain an overview of reporting bias in the medical literature, focussing on publication bias and selective outcome reporting. We explore whether these types of bias have been shown in areas beyond the well-known cases noted above, in order to gain an impression of how widespread the problem is. For this purpose, we screened relevant articles on reporting bias that had previously been obtained by the German Institute for Quality and Efficiency in Health Care in the context of its health technology assessment reports and other research work, together with the reference lists of these articles. We identified reporting bias in 40 indications comprising around 50 different pharmacological, surgical (e.g. vacuum-assisted closure therapy, diagnostic (e.g. ultrasound, and preventive (e.g. cancer vaccines interventions. Regarding pharmacological interventions, cases of reporting bias were, for example, identified in the treatment of the following conditions: depression, bipolar disorder, schizophrenia, anxiety disorder, attention-deficit hyperactivity disorder, Alzheimer's disease, pain, migraine, cardiovascular disease, gastric ulcers, irritable bowel syndrome, urinary incontinence, atopic dermatitis, diabetes mellitus type 2, hypercholesterolaemia, thyroid disorders, menopausal symptoms, various types of cancer (e.g. ovarian cancer and melanoma, various types of infections (e.g. HIV, influenza and Hepatitis B, and acute trauma. Many cases involved the withholding of study data by manufacturers and regulatory agencies or the active attempt by manufacturers to suppress publication. The ascertained effects of reporting bias included the

A comparator-hypothesis account of biased contingency detection.

Science.gov (United States)

Vadillo, Miguel A; Barberia, Itxaso

2018-02-12

Our ability to detect statistical dependencies between different events in the environment is strongly biased by the number of coincidences between them. Even when there is no true covariation between a cue and an outcome, if the marginal probability of either of them is high, people tend to perceive some degree of statistical contingency between both events. The present paper explores the ability of the Comparator Hypothesis to explain the general pattern of results observed in this literature. Our simulations show that this model can account for the biasing effects of the marginal probabilities of cues and outcomes. Furthermore, the overall fit of the Comparator Hypothesis to a sample of experimental conditions from previous studies is comparable to that of the popular Rescorla-Wagner model. These results should encourage researchers to further explore and put to the test the predictions of the Comparator Hypothesis in the domain of biased contingency detection. Copyright © 2018 Elsevier B.V. All rights reserved.

Electronic properties of a biased graphene bilayer

International Nuclear Information System (INIS)

Castro, Eduardo V; Lopes dos Santos, J M B; Novoselov, K S; Morozov, S V; Geim, A K; Peres, N M R; Nilsson, Johan; Castro Neto, A H; Guinea, F

2010-01-01

We study, within the tight-binding approximation, the electronic properties of a graphene bilayer in the presence of an external electric field applied perpendicular to the system-a biased bilayer. The effect of the perpendicular electric field is included through a parallel plate capacitor model, with screening correction at the Hartree level. The full tight-binding description is compared with its four-band and two-band continuum approximations, and the four-band model is shown to always be a suitable approximation for the conditions realized in experiments. The model is applied to real biased bilayer devices, made out of either SiC or exfoliated graphene, and good agreement with experimental results is found, indicating that the model is capturing the key ingredients, and that a finite gap is effectively being controlled externally. Analysis of experimental results regarding the electrical noise and cyclotron resonance further suggests that the model can be seen as a good starting point for understanding the electronic properties of graphene bilayer. Also, we study the effect of electron-hole asymmetry terms, such as the second-nearest-neighbour hopping energies t' (in-plane) and γ 4 (inter-layer), and the on-site energy Δ.

Analysis of the giant magnetostrictive actuator with strong bias magnetic field

Energy Technology Data Exchange (ETDEWEB)

Xue, Guangming, E-mail: yy0youxia@163.com; He, Zhongbo; Li, Dongwei; Yang, Zhaoshu; Zhao, Zhenglong

2015-11-15

Giant magnetostrictive actuator with strong bias magnetic field is designed to control the injector bullet valve opening and closing. The relationship between actuator displacement amplitude and input signal direction is analyzed. And based on the approximate linearity of strain-magnetic field, second-order system model of the actuator displacement is established. Experimental system suitable for the actuator is designed. The experimental results show that, the square voltage amplitude being 12 V, the actuator displacement amplitude is about 17 μm with backward direction signal input while being 1.5 μm under forward direction signal. From the results, the suitable input direction is confirmed to be backward. With exciting frequncy lower than 200 Hz, the error between the model and experimental result is less than 1.7 μm. So the model is validated under the low-frequency signal input. The testing displacement-voltage curves are approximately straight lines. But due to the biased position, the line slope and the displacement-voltage linearity change as the input voltage changes. - Highlights: • Giant magnetostrictive actuator with strong bias magnetic field is designed. • The relationship between actuator displacement amplitude and input current direction is analyzed. • The model of the actuator displacement is established and its accuracy is verified by the test. • The actuator displacement-voltage curves are achieved by the test, and the curves’ characteristics are analyzed theoretically.

Transmission of Cognitive Bias and Fear From Parents to Children : An Experimental Study

NARCIS (Netherlands)

Remmerswaal, Danielle; Muris, Peter; Huijding, Jorg|info:eu-repo/dai/nl/292646976

2016-01-01

This study explored the role of parents in the development of a cognitive bias and subsequent fear levels in children. In Experiment 1, nonclinical children ages 8–13 (N = 122) underwent a training during which they worked together with their mothers on an information search task. Mothers received

Exploring elements of fun to motivate youth to do cognitive bias modification

NARCIS (Netherlands)

Boendermaker, W.J.; Boffo, M.; Wiers, R.W.

2015-01-01

Objective: Heavy drinking among young adults poses severe health risks, including development of later addiction problems. Cognitive retraining of automatic appetitive processes related to alcohol (so-called cognitive bias modification [CBM]) may help to prevent escalation of use. Although effective

Survival, Look-Ahead Bias and the Persistence in Hedge Fund Performance

NARCIS (Netherlands)

Baquero, G.; Ter Horst, J.R.; Verbeek, M.J.C.M.

2002-01-01

Hedge funds databases are typicall subject to high attrition rates because of fund termination and self-selection.Even when all funds are included up to their last available return, one cannot prevent that ex post conditioning biases affect standard estimates of performance persistence.In this paper

A meta-analysis of the effects of dropout prevention programs on school absenteeism.

Science.gov (United States)

Tanner-Smith, Emily E; Wilson, Sandra Jo

2013-10-01

This study reports findings from a systematic review and meta-analysis of literature examining the effects of school dropout prevention and intervention programs on students' school absenteeism outcomes. The meta-analysis synthesized 74 effect sizes measuring posttest differences in school absenteeism outcomes for youth enrolled in dropout prevention programs relative to a comparison group. Although results from randomized controlled trials indicated significant beneficial program effects, findings from quasi-experimental studies indicated no significant beneficial or detrimental effects. Examination of study characteristics suggested that dropout programs may have beneficial effects on school absenteeism among primarily male samples, and younger samples. Although no single type of intervention program was consistently more effective than others, vocational oriented and supplemental academic training programs showed some promise. However, the inconsistency in results and the possibility of small study bias mean the quality of evidence in this literature is low; at this time there is not enough evidence to conclude that dropout prevention programs have a universal impact on youth's school absenteeism outcomes.

Decay of velvet worms (Onychophora), and bias in the fossil record of lobopodians.

Science.gov (United States)

Murdock, Duncan Je; Gabbott, Sarah E; Mayer, Georg; Purnell, Mark A

2014-11-29

Fossil lobopodians, including animals proposed to have close affinity to modern onychophorans, are crucial to understanding the evolution of the panarthropod body plan and the phylum-level relationships between the ecdysozoan groups. Unfortunately, the key features of their anatomy are un-mineralized and subject to biases introduced during death, decay and preservation, yet the extent to which these fossils have been affected by the processes of post-mortem decay is entirely untested. Recent experimental work on chordates has highlighted a profound bias caused by decay, resulting in the erroneous interpretation of badly decayed specimens as primitive members of a clade (stemward slippage). The degree to which this bias affects organisms other than chordates is unknown. Here we use experimental decay of velvet worms (Onychophora) to examine the importance of decay bias in fossil lobopodians. Although we find stemward slippage is not significant in the interpretation of non-mineralized lobopodian fossils, the affect of decay is far from unbiased. Quantitative analysis reveals significant changes in body proportions during decay, a spectrum of decay resistance across anatomical features, and correlated decay of topologically associated characters. These results have significant implications for the interpretation of fossil lobopodian remains, demonstrating that features such as body outline and relative proportions are unreliable for taxonomy or phylogenetic reconstruction, unless decay is taken into account. Similarly, the non-independent loss of characters, due to juxtaposition in the body, during decay has the potential to bias phylogenetic analyses of non-biomineralized fossils. Our results are difficult to reconcile with interpretations of highly decay-prone tissues and structures, such as neural tissue, and complex musculature, in recently described Cambrian lobopodians. More broadly, we hypothesize that stemward slippage is unlikely to be a significant factor

Bias polarity-sensitive electrical failure characteristics of ZnSe nanowire in metal–semiconductor–metal nanostructure

Directory of Open Access Journals (Sweden)

Yu Tan

2014-04-01

Full Text Available The effect of bias polarity on the electrical breakdown behavior of the single ZnSe nanowire (NW in the metal–semiconductor–metal (M–S–M nanostructure under high current density and high bias conditions has been studied in the present paper. The experimental results show that the failure of the ZnSe NW in M–S–M nanostructure was sensitive to bias polarity since the NW commonly collapsed at the negatively biased Au metal electrode due to high Joule heat produced in NW at the reversely biased Schottky barrier. Thus, the electrical breakdown behavior of the ZnSe NW was highly dominated by the cathode-controlled mode due to the high resistance of the depletion region of ZnSe NW at the reversely biased Schottky contact.

Preventive Effect of Zea mays L. (Purple Waxy Corn) on Experimental Diabetic Cataract

OpenAIRE

Thiraphatthanavong, Paphaphat; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Thukham-mee, Wipawee; Wannanon, Panakaporn; Tong-un, Terdthai; Suriharn, Bhalang; Lertrat, Kamol

2014-01-01

Recently, substances possessing antioxidant can prevent cataractogenesis of diabetic cataract. Therefore, this study was carried out to determine the anticataract effect of Zea mays L. (purple waxy corn), a flavonoids rich plant, in experimental diabetic cataract. Enucleated rat lenses were incubated in artificial aqueous humor containing 55 mM glucose with various concentrations of Zea mays L. (purple waxy corn) ranging between 2, 10, and 50 mg/mL at room temperature for 72 h. At the end of ...

Chewing Stimulation Reduces Appetite Ratings and Attentional Bias toward Visual Food Stimuli in Healthy-Weight Individuals.

Science.gov (United States)

Ikeda, Akitsu; Miyamoto, Jun J; Usui, Nobuo; Taira, Masato; Moriyama, Keiji

2018-01-01

Based on the theory of incentive sensitization, the exposure to food stimuli sensitizes the brain's reward circuits and enhances attentional bias toward food. Therefore, reducing attentional bias to food could possibly be beneficial in preventing impulsive eating. The importance of chewing has been increasingly implicated as one of the methods for reducing appetite, however, no studies to investigate the effect of chewing on attentional bias to food. In this study, we investigated whether chewing stimulation (i.e., chewing tasteless gum) reduces attentional bias to food as well as an actual feeding (i.e., ingesting a standardized meal) does. We measured reaction time, gaze direction and gaze duration to assess attentional bias toward food images in pairs of food and non-food images that were presented in a visual probe task (Experiment 1, n = 21) and/or eye-tracking task (Experiment 2, n = 20). We also measured appetite ratings using visual analog scale. In addition, we conducted a control study in which the same number of participants performed the identical tasks to Experiments 1 and 2, but the participants did not perform sham feeding with gum-chewing/actual feeding between tasks and they took a rest. Two-way ANOVA revealed that after actual feeding, subjective ratings of hunger, preoccupation with food, and desire to eat significantly decreased, whereas fullness significantly increased. Sham feeding showed the same trends, but to a lesser degree. Results of the visual probe task in Experiment 1 showed that both sham feeding and actual feeding reduced reaction time bias significantly. Eye-tracking data showed that both sham and actual feeding resulted in significant reduction in gaze direction bias, indexing initial attentional orientation. Gaze duration bias was unaffected. In both control experiments, one-way ANOVAs showed no significant differences between immediately before and after the resting state for any of the appetite ratings, reaction time bias, gaze

Chewing Stimulation Reduces Appetite Ratings and Attentional Bias toward Visual Food Stimuli in Healthy-Weight Individuals

Science.gov (United States)

Ikeda, Akitsu; Miyamoto, Jun J.; Usui, Nobuo; Taira, Masato; Moriyama, Keiji

2018-01-01

Based on the theory of incentive sensitization, the exposure to food stimuli sensitizes the brain’s reward circuits and enhances attentional bias toward food. Therefore, reducing attentional bias to food could possibly be beneficial in preventing impulsive eating. The importance of chewing has been increasingly implicated as one of the methods for reducing appetite, however, no studies to investigate the effect of chewing on attentional bias to food. In this study, we investigated whether chewing stimulation (i.e., chewing tasteless gum) reduces attentional bias to food as well as an actual feeding (i.e., ingesting a standardized meal) does. We measured reaction time, gaze direction and gaze duration to assess attentional bias toward food images in pairs of food and non-food images that were presented in a visual probe task (Experiment 1, n = 21) and/or eye-tracking task (Experiment 2, n = 20). We also measured appetite ratings using visual analog scale. In addition, we conducted a control study in which the same number of participants performed the identical tasks to Experiments 1 and 2, but the participants did not perform sham feeding with gum-chewing/actual feeding between tasks and they took a rest. Two-way ANOVA revealed that after actual feeding, subjective ratings of hunger, preoccupation with food, and desire to eat significantly decreased, whereas fullness significantly increased. Sham feeding showed the same trends, but to a lesser degree. Results of the visual probe task in Experiment 1 showed that both sham feeding and actual feeding reduced reaction time bias significantly. Eye-tracking data showed that both sham and actual feeding resulted in significant reduction in gaze direction bias, indexing initial attentional orientation. Gaze duration bias was unaffected. In both control experiments, one-way ANOVAs showed no significant differences between immediately before and after the resting state for any of the appetite ratings, reaction time bias

Biases in spatial bisection induced by viewing male and female faces.

Science.gov (United States)

Cattaneo, Zaira; Schiavi, Susanna; Lega, Carlotta; Renzi, Chiara; Tagliaferri, Matteo; Boehringer, Jana; Carbon, Claus-Christian; Vecchi, Tomaso

2014-01-01

Research on visual attention triggered by face gender is still relatively sparse. In the present study, three experiments are reported in which male and female participants were required to estimate the midpoint of a line (i.e., the "line bisection task"): at each end of the line a face was presented. Depending on the experimental condition, faces could be of the same gender (i.e., two males or two females) or the opposite gender. Experiments 1 and 2 converged in showing that when a male face was presented at the right and a female face at the left endpoint of the line, a clear rightward bias emerged compared to the other experimental conditions, indicating that male faces captured attention more than female faces. Importantly, male faces used across Experiments 1 and 2 were rated as more threatening than female faces, suggesting that perceived level of threat may have been responsible for the observed bias toward the male face. Experiment 3 corroborated this hypothesis by finding an attentional bias toward the male face with high threat (angry) faces but not with low threat (smiling) faces.

Xylitol and caries prevention.

Science.gov (United States)

Duane, Brett

2015-06-01

Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, CINAHL, Web of Science Conference Proceedings, Proquest Dissertations and Theses, US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the WHO Clinical Trials Registry Platform for ongoing trials. No language or year restrictions were used. Randomised controlled trials assessing the effects of xylitol products on dental caries in children and adults. Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. Authors were contacted where possible for missing data or clarification where feasible. For continuous outcomes, means and standard deviations were used to obtain the mean difference and 95% confidence interval (CI). Continuous data was used to calculate prevented fractions (PF) and 95% CIs to summarise the percentage reduction in caries. For dichotomous outcomes, reported risk ratios (RR) and 95% CIs were used. As there were fewer than four studies included in the meta-analysis, a fixed effect model was used. Ten studies were included with a total of 5903 participants. One study was assessed as being at low risk of bias, two were assessed as unclear risk of bias with seven at high risk of bias. Over 2.5–3 years, low quality evidence demonstrated that with 4216 children analysed, a fluoride toothpaste with 10% xylitol (exact dosage unsure) reduced caries by 13% when compared to a fluoride only toothpaste. (PF −0.13, 95% CI −0.18 to −0.08. Remaining evidence of the use of xylitol in children has risk of bias and uncertainty of effect and was therefore insufficient to determine a benefit from xylitol. Four studies reported that there were no adverse effects from any of the interventions. Two studies reported similar rates of adverse effects between study arms. The remaining studies either mentioned adverse effects

Benfotiamine blocks three major pathways of hyperglycemic damage and prevents experimental diabetic retinopathy.

Science.gov (United States)

Hammes, Hans-Peter; Du, Xueliang; Edelstein, Diane; Taguchi, Tetsuya; Matsumura, Takeshi; Ju, Qida; Lin, Jihong; Bierhaus, Angelika; Nawroth, Peter; Hannak, Dieter; Neumaier, Michael; Bergfeld, Regine; Giardino, Ida; Brownlee, Michael

2003-03-01

Three of the major biochemical pathways implicated in the pathogenesis of hyperglycemia induced vascular damage (the hexosamine pathway, the advanced glycation end product (AGE) formation pathway and the diacylglycerol (DAG)-protein kinase C (PKC) pathway) are activated by increased availability of the glycolytic metabolites glyceraldehyde-3-phosphate and fructose-6-phosphate. We have discovered that the lipid-soluble thiamine derivative benfotiamine can inhibit these three pathways, as well as hyperglycemia-associated NF-kappaB activation, by activating the pentose phosphate pathway enzyme transketolase, which converts glyceraldehyde-3-phosphate and fructose-6-phosphate into pentose-5-phosphates and other sugars. In retinas of diabetic animals, benfotiamine treatment inhibited these three pathways and NF-kappaB activation by activating transketolase, and also prevented experimental diabetic retinopathy. The ability of benfotiamine to inhibit three major pathways simultaneously might be clinically useful in preventing the development and progression of diabetic complications.

Common Bias Readout for TES Array on Scanning Transmission Electron Microscope

Science.gov (United States)

Yamamoto, R.; Sakai, K.; Maehisa, K.; Nagayoshi, K.; Hayashi, T.; Muramatsu, H.; Nakashima, Y.; Mitsuda, K.; Yamasaki, N. Y.; Takei, Y.; Hidaka, M.; Nagasawa, S.; Maehata, K.; Hara, T.

2016-07-01

A transition edge sensor (TES) microcalorimeter array as an X-ray sensor for a scanning transmission electron microscope system is being developed. The technical challenge of this system is a high count rate of ˜ 5000 counts/second/array. We adopted a 64 pixel array with a parallel readout. Common SQUID bias, and common TES bias are planned to reduce the number of wires and the resources of a room temperature circuit. The reduction rate of wires is 44 % when a 64 pixel array is read out by a common bias of 8 channels. The possible degradation of the energy resolution has been investigated by simulations and experiments. The bias fluctuation effects of a series connection are less than those of a parallel connection. Simple calculations expect that the fluctuations of the common SQUID bias and common TES bias in a series connection are 10^{-7} and 10^{-3}, respectively. We constructed 8 SQUIDs which are connected to 8 TES outputs and a room temperature circuit for common bias readout and evaluated experimentally. Our simulation of crosstalk indicates that at an X-ray event rate of 500 cps/pixel, crosstalk will broaden a monochromatic line by about 0.01 %, or about 1.5 eV at 15 keV. Thus, our design goal of 10 eV energy resolution across the 0.5-15 keV band should be achievable.

Journal bias or author bias?

Science.gov (United States)

Harris, Ian

2016-01-01

I read with interest the comment by Mark Wilson in the Indian Journal of Medical Ethics regarding bias and conflicts of interest in medical journals. Wilson targets one journal (the New England Journal of Medicine: NEJM) and one particular "scandal" to make his point that journals' decisions on publication are biased by commercial conflicts of interest (CoIs). It is interesting that he chooses the NEJM which, by his own admission, had one of the strictest CoI policies and had published widely on this topic. The feeling is that if the NEJM can be guilty, they can all be guilty.

Modification of cognitive biases related to posttraumatic stress: A systematic review and research agenda.

Science.gov (United States)

Woud, Marcella L; Verwoerd, Johan; Krans, Julie

2017-06-01

Cognitive models of Posttraumatic Stress Disorder (PTSD) postulate that cognitive biases in attention, interpretation, and memory represent key factors involved in the onset and maintenance of PTSD. Developments in experimental research demonstrate that it may be possible to manipulate such biases by means of Cognitive Bias Modification (CBM). In the present paper, we summarize studies assessing cognitive biases in posttraumatic stress to serve as a theoretical and methodological background. However, our main aim was to provide an overview of the scientific literature on CBM in (analogue) posttraumatic stress. Results of our systematic literature review showed that most CBM studies targeted attentional and interpretation biases (attention: five studies; interpretation: three studies), and one study modified memory biases. Overall, results showed that CBM can indeed modify cognitive biases and affect (analog) trauma symptoms in a training congruent manner. Interpretation bias procedures seemed effective in analog samples, and memory bias training proved preliminary success in a clinical PTSD sample. Studies of attention bias modification provided more mixed results. This heterogeneous picture may be explained by differences in the type of population or variations in the CBM procedure. Therefore, we sketched a detailed research agenda targeting the challenges for CBM in posttraumatic stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonresponse bias in randomized controlled experiments in criminology: Putting the Queensland Community Engagement Trial (QCET) under a microscope.

Science.gov (United States)

Antrobus, Emma; Elffers, Henk; White, Gentry; Mazerolle, Lorraine

2013-01-01

The goal of this article is to examine whether or not the results of the Queensland Community Engagement Trial (QCET)-a randomized controlled trial that tested the impact of procedural justice policing on citizen attitudes toward police-were affected by different types of nonresponse bias. We use two methods (Cochrane and Elffers methods) to explore nonresponse bias: First, we assess the impact of the low response rate by examining the effects of nonresponse group differences between the experimental and control conditions and pooled variance under different scenarios. Second, we assess the degree to which item response rates are influenced by the control and experimental conditions. Our analysis of the QCET data suggests that our substantive findings are not influenced by the low response rate in the trial. The results are robust even under extreme conditions, and statistical significance of the results would only be compromised in cases where the pooled variance was much larger for the nonresponse group and the difference between experimental and control conditions was greatly diminished. We also find that there were no biases in the item response rates across the experimental and control conditions. RCTs that involve field survey responses-like QCET-are potentially compromised by low response rates and how item response rates might be influenced by the control or experimental conditions. Our results show that the QCET results were not sensitive to the overall low response rate across the experimental and control conditions and the item response rates were not significantly different across the experimental and control groups. Overall, our analysis suggests that the results of QCET are robust and any biases in the survey responses do not significantly influence the main experimental findings.

Experimental evidence of spin glass and exchange bias behavior in sputtered grown α-MnO{sub 2} nanorods

Energy Technology Data Exchange (ETDEWEB)

Kumar, Ashwani; Sanger, Amit; Singh, Amit Kumar; Kumar, Arvind [Nanoscience Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Kumar, Mohit [Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Chandra, Ramesh [Nanoscience Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

2017-07-01

Highlights: • We have synthesized the α-MnO{sub 2} nanorods by using DC reactive sputtering. • We observed Spin glass and exchange bias behavior at low temperature in sputtered grown α-MnO{sub 2} nanorods. • Exchange bias arises due to exchange coupling of uncompensated FM spins and AFM spins at FM/AFM interface. - Abstract: Here, we present a single-step process to synthesize the α-MnO{sub 2} nanorods forest using reactive DC magnetron sputtering for the application of magnetic memories. The structural and morphological properties of the α-MnO{sub 2} nanorods were systematically studied using numerous analytical techniques, including X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy and transmission electron microscopy. The magnetic measurements suggest that the α-MnO{sub 2} nanorods exhibit spin glass and exchange bias behaviour at low temperature. Such low temperature behaviour is explained by the core-shell type structure of nanorods. Antiferromagnetic core and shell of uncompensated ferromagnetic spins leads to the formation of antiferromagnetic/ferromagnetic (AFM/FM) interfaces, which originates exchange bias in the sample.

Beyond assembly bias: exploring secondary halo biases for cluster-size haloes

Science.gov (United States)

Mao, Yao-Yuan; Zentner, Andrew R.; Wechsler, Risa H.

2018-03-01

Secondary halo bias, commonly known as `assembly bias', is the dependence of halo clustering on a halo property other than mass. This prediction of the Λ Cold Dark Matter cosmology is essential to modelling the galaxy distribution to high precision and interpreting clustering measurements. As the name suggests, different manifestations of secondary halo bias have been thought to originate from halo assembly histories. We show conclusively that this is incorrect for cluster-size haloes. We present an up-to-date summary of secondary halo biases of high-mass haloes due to various halo properties including concentration, spin, several proxies of assembly history, and subhalo properties. While concentration, spin, and the abundance and radial distribution of subhaloes exhibit significant secondary biases, properties that directly quantify halo assembly history do not. In fact, the entire assembly histories of haloes in pairs are nearly identical to those of isolated haloes. In general, a global correlation between two halo properties does not predict whether or not these two properties exhibit similar secondary biases. For example, assembly history and concentration (or subhalo abundance) are correlated for both paired and isolated haloes, but follow slightly different conditional distributions in these two cases. This results in a secondary halo bias due to concentration (or subhalo abundance), despite the lack of assembly bias in the strict sense for cluster-size haloes. Due to this complexity, caution must be exercised in using any one halo property as a proxy to study the secondary bias due to another property.

Divertor plasma modification by divertor biasing and edge ergodization in JFT-2M

International Nuclear Information System (INIS)

Shoji, T.; Nagashima, K.; Tamai, H.; Ohdachi, S.; Miura, Y.; Ohasa, K.; Maeda, H.; Ohyabu, N.; Leonard, A.W.; Aikawa, H.; Fujita, T.; Hoshino, K.; Kawashima, H.; Matsuda, T.; Maeno, M.; Mori, M.; Ogawa, H.; Shimada, M.; Uehara, K.; Yamauchi, T.

1995-01-01

The effects of divertor biasing and edge ergodization on the divertor plasma have been investigated in the JFT-2M tokamak. Experimental results show; (1) The differential divertor biasing can change the in/out asymmetry of the divertor plasma. It especially changes the density on the ion side divertor plasma. The in/out electron pressure difference has a good correlation with the biasing current. (2) The unipolar divertor biasing can change the density profile of divertor plasma. The radial electric field and shear flow are the cause for this change. (3) The electron temperature of the divertor plasma in the H-mode with frequent ELMs induced by edge ergodization is lower than that of usual H-mode. That is due to the enhancement of the radial particle flux by frequent ELMs, ((orig.))

Experimental investigation on NO{sub x} emission and carbon burnout from a radially biased pulverized coal whirl burner

Energy Technology Data Exchange (ETDEWEB)

Xue, Shan; Hui, Shi' en; Zhou, Qulan; Xu, Tongmo; Hu, Hongli [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Liu, Taisheng [Dongfang Boiler Group Co., Ltd., Zigong, Sichuan 643001 (China)

2009-09-15

Experiments have been performed on 1 MW pulverized coal (pc) furnace in order to investigate the characteristics of coal combustion and NO{sub x} emission from a new type of radially biased dual register whirl burner. The burner is characterized by a primary air pipe with a continuously changing cross-section and an impact ring. The mixture of pulverized coal and air inside the primary pipe is split into two streams, which are the outer pc rich annular jet and the inner pc lean annular jet respectively. Three Chinese coals, which are high rank bituminous coal, low rank bituminous coal and meager coal respectively, are used in the experiments. We examine the influences of various parameters such as the relative position of the over-fire air (OFA) nozzle, over-fire air ratio (19.1%), primary air ratio, inner secondary air ratio, outer secondary air ratio, inner secondary air swirling intensity, and outer secondary air swirling intensity on NO{sub x} formation and unburned carbon in fly ash. With the primary air ratio increasing from 13.4% to 23.4%, the value of the NO{sub x} emission of the SH coal decreases by 26.7% at first, and then increases by 21.7%. In contrast, the value of the carbon in fly ash (C{sub FA}) increases by 40.1% at first, and then decreases by 58.3%. According to the experimental results, the influence of each individual parameter on NO{sub x} formation and unburned carbon in fly ash agrees well with the existing literature. In this study, the influences of various combinations of these parameters are also examined, thus providing some reference for the design of the radial biased whirl burner, the configuration of the furnace and the distribution of the air. (author)

Self-reported Cognitive Biases Moderate the Associations Between Social Stress and Paranoid Ideation in a Virtual Reality Experimental Study

NARCIS (Netherlands)

Pot-Kolder, Roos; Veling, Wim; Counotte, Jacqueline; van der Gaag, Mark

2017-01-01

Introduction: Cognitive biases are associated with psychosis liability and paranoid ideation. This study investigated the moderating relationship between pre-existing self-reported cognitive biases and the occurrence of paranoid ideation in response to different levels of social stress in a virtual

Development and application of the automated Monte Carlo biasing procedure in SAS4

International Nuclear Information System (INIS)

Tang, J.S.; Broadhead, B.L.

1993-01-01

An automated approach for biasing Monte Carlo shielding calculations is described. In particular, adjoint fluxes from a one-dimensional discrete-ordinates calculation are used to generate biasing parameters for a three-dimensional Monte Carlo calculation. The automated procedure consisting of cross-section processing, adjoint flux determination, biasing parameter generation, and the initiation of a MORSE-SGC/S Monte Carlo calculation has been implemented in the SAS4 module of the SCALE computer code system. The automated procedure has been used extensively in the investigation of both computational and experimental benchmarks for the NEACRP working group on shielding assessment of transportation packages. The results of these studies indicate that with the automated biasing procedure, Monte Carlo shielding calculations of spent fuel casks can be easily performed with minimum effort and that accurate results can be obtained at reasonable computing cost. The systematic biasing approach described in this paper can also be applied to other similar shielding problems

Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope.

Science.gov (United States)

Li, Xuyou; Liu, Pan; Guang, Xingxing; Xu, Zhenlong; Guan, Lianwu; Li, Guangchun

2017-09-07

Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG.

Safe Kids Week: Analysis of gender bias in a national child safety campaign, 1997-2016.

Science.gov (United States)

Bauer, Michelle E E; Brussoni, Mariana; Giles, Audrey R; Fuselli, Pamela

2017-09-29

Background and Purpose Child safety campaigns play an important role in disseminating injury prevention information to families. A critical discourse analysis of gender bias in child safety campaign marketing materials can offer important insights into how families are represented and the potential influence that gender bias may have on uptake of injury prevention information. Methods Our approach was informed by poststructural feminist theory, and we used critical discourse analysis to identify discourses within the poster materials. We examined the national Safe Kids Canada Safe Kids Week campaign poster material spanning twenty years (1997-2016). Specifically, we analyzed the posters' typeface, colour, images, and language to identify gender bias in relation to discourses surrounding parenting, safety, and societal perceptions of gender. Results The findings show that there is gender bias present in the Safe Kids Week poster material. The posters represent gender as binary, mothers as primary caregivers, and showcase stereotypically masculine sporting equipment among boys and stereotypically feminine equipment among girls. Interestingly, we found that the colour and typeface of the text both challenge and perpetuate the feminization of safety. Discussion It is recommended that future child safety campaigns represent changing family dynamics, include representations of children with non-traditionally gendered sporting equipment, and avoid the representation of gender as binary. This analysis contributes to the discussion of the feminization of safety in injury prevention research and challenges the ways in which gender is represented in child safety campaigns. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Biased Agonism of Endogenous Opioid Peptides at the μ-Opioid Receptor.

Science.gov (United States)

Thompson, Georgina L; Lane, J Robert; Coudrat, Thomas; Sexton, Patrick M; Christopoulos, Arthur; Canals, Meritxell

2015-08-01

Biased agonism is having a major impact on modern drug discovery, and describes the ability of distinct G protein-coupled receptor (GPCR) ligands to activate different cell signaling pathways, and to result in different physiologic outcomes. To date, most studies of biased agonism have focused on synthetic molecules targeting various GPCRs; however, many of these receptors have multiple endogenous ligands, suggesting that "natural" bias may be an unappreciated feature of these GPCRs. The μ-opioid receptor (MOP) is activated by numerous endogenous opioid peptides, remains an attractive therapeutic target for the treatment of pain, and exhibits biased agonism in response to synthetic opiates. The aim of this study was to rigorously assess the potential for biased agonism in the actions of endogenous opioids at the MOP in a common cellular background, and compare these to the effects of the agonist d-Ala2-N-MePhe4-Gly-ol enkephalin (DAMGO). We investigated activation of G proteins, inhibition of cAMP production, extracellular signal-regulated kinase 1 and 2 phosphorylation, β-arrestin 1/2 recruitment, and MOP trafficking, and applied a novel analytical method to quantify biased agonism. Although many endogenous opioids displayed signaling profiles similar to that of DAMGO, α-neoendorphin, Met-enkephalin-Arg-Phe, and the putatively endogenous peptide endomorphin-1 displayed particularly distinct bias profiles. These may represent examples of natural bias if it can be shown that they have different signaling properties and physiologic effects in vivo compared with other endogenous opioids. Understanding how endogenous opioids control physiologic processes through biased agonism can reveal vital information required to enable the design of biased opioids with improved pharmacological profiles and treat diseases involving dysfunction of the endogenous opioid system. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Impact of back-gate bias on the hysteresis effect in partially depleted SOI MOSFETs

International Nuclear Information System (INIS)

Luo Jie-Xin; Chen Jing; Zhou Jian-Hua; Wu Qing-Qing; Chai Zhan; Yu Tao; Wang Xi

2012-01-01

The hysteresis effect in the output characteristics, originating from the floating body effect, has been measured in partially depleted (PD) silicon-on-insulator (SOI) MOSFETs at different back-gate biases. I D hysteresis has been developed to clarify the hysteresis characteristics. The fabricated devices show the positive and negative peaks in the I D hysteresis. The experimental results show that the I D hysteresis is sensitive to the back gate bias in 0.13-μm PD SOI MOSFETs and does not vary monotonously with the back-gate bias. Based on the steady-state Shockley-Read-Hall (SRH) recombination theory, we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs. (condensed matter: structural, mechanical, and thermal properties)

Vortex-Concept for Radioactivity Release Prevention at NPP: Development of Computational Model of Lab-Scale Experimental Setup

Energy Technology Data Exchange (ETDEWEB)

Ullah, Sana; Sung, Yim Man; Park, Jin Soo; Sung Hyung Jin [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The experimental validation of the vortex-like air curtain concept and use of an appropriate CFD modelling approach for analyzing the problem becomes crucial. A lab-scale experimental setup is designed to validate the proposed concept and CFD modeling approach as a part of validation process. In this study, a computational model of this lab-scale experiment setup is developed using open source CFD code OpenFOAM. The computational results will be compared with experimental data for validation purposes in future, when experimental data is available. 1) A computation model of a lab-scale experimental setup, designed to validate the concept of artificial vortex-like airflow generation for application to radioactivity dispersion prevention in the event of severe accident, was developed. 2) The mesh sensitivity study was performed and a mesh of about 2 million cells was found to be sufficient for this setup.

CPI Bias in Korea

Directory of Open Access Journals (Sweden)

Chul Chung

2007-12-01

Full Text Available We estimate the CPI bias in Korea by employing the approach of Engel’s Law as suggested by Hamilton (2001. This paper is the first attempt to estimate the bias using Korean panel data, Korean Labor and Income Panel Study(KLIPS. Following Hamilton’s model with non­linear specification correction, our estimation result shows that the cumulative CPI bias over the sample period (2000-2005 was 0.7 percent annually. This CPI bias implies that about 21 percent of the inflation rate during the period can be attributed to the bias. In light of purchasing power parity, we provide an interpretation of the estimated bias.

Active Sensor for Microwave Tissue Imaging with Bias-Switched Arrays.

Science.gov (United States)

Foroutan, Farzad; Nikolova, Natalia K

2018-05-06

A prototype of a bias-switched active sensor was developed and measured to establish the achievable dynamic range in a new generation of active arrays for microwave tissue imaging. The sensor integrates a printed slot antenna, a low-noise amplifier (LNA) and an active mixer in a single unit, which is sufficiently small to enable inter-sensor separation distance as small as 12 mm. The sensor’s input covers the bandwidth from 3 GHz to 7.5 GHz. Its output intermediate frequency (IF) is 30 MHz. The sensor is controlled by a simple bias-switching circuit, which switches ON and OFF the bias of the LNA and the mixer simultaneously. It was demonstrated experimentally that the dynamic range of the sensor, as determined by its ON and OFF states, is 109 dB and 118 dB at resolution bandwidths of 1 kHz and 100 Hz, respectively.

Exponential dependence of potential barrier height on biased voltages of inorganic/organic static induction transistor

International Nuclear Information System (INIS)

Zhang Yong; Yang Jianhong; Cai Xueyuan; Wang Zaixing

2010-01-01

The exponential dependence of the potential barrier height φ c on the biased voltages of the inorganic/organic static induction transistor (SIT/OSIT) through a normalized approach in the low-current regime is presented. It shows a more accurate description than the linear expression of the potential barrier height. Through the verification of the numerical calculated and experimental results, the exponential dependence of φ c on the applied biases can be used to derive the I-V characteristics. For both SIT and OSIT, the calculated results, using the presented relationship, are agreeable with the experimental results. Compared to the previous linear relationship, the exponential description of φ c can contribute effectively to reduce the error between the theoretical and experimental results of the I-V characteristics. (semiconductor devices)

Characterization of electrostatic actuators for suspended mirror control with modulated bias

International Nuclear Information System (INIS)

De Rosa, R; Garufi, F; Milano, L; Mosca, S; Persichetti, G

2010-01-01

Electrostatic actuators are one of the most promising devices for mirror control in advanced gravitational waves detectors. An accurate characterization of such actuators is required for a correct design, able to satisfy the requirement of the control system, both in term of low noise content as well as to fit the required dynamic range. To this aim a simple and effective experimental set-up was developed, consisting in a suspended mirror which displacement, induced by an electrostatic actuator, is measured by using an optical lever. The effect of stray patch charge on the mirror was minimized by using an alternate voltage as bias reference for the actuator. Different working conditions were investigated, in particular by varying the mirror-actuator distance and the bias amplitude. The experimental results were compared to the prediction of a numerical model taking into account the actuator geometry and the working conditions.

Cynodon dactylon extract as a preventive and curative agent in experimentally induced nephrolithiasis.

Science.gov (United States)

Atmani, F; Sadki, C; Aziz, M; Mimouni, M; Hacht, B

2009-04-01

Cynodon dactylon (Poaceae family) decoction was used in the treatment of kidney stones. However, no scientific study was undertaken so far to demonstrate the beneficial effect of the plant. Thus, the aim of the current study is to evaluate the effect of Cynodon aqueous extract as a preventive and curative agent in experimentally induced nephrolithiasis in a rat model. Ethylene glycol (EG) was used in the experiment to induce calcium oxalate (CaOx) deposition into kidneys. In preventive protocol, Cynodon decoction was administered in the same day with EG to evaluate the ability of the extract to prevent crystal deposition. However, in curative protocol, rats were first rendered nephrolithiasic and then the extract was administered to assess the ability of the plant to eliminate the pre-existing crystal deposition. In both protocols, urinary biochemical and other variables were measured during the course of the study. Crystalluria and renal histology were examined as well. The results showed that, in both protocols, all measured variables were similar for both the rat groups. Nevertheless, urinary biochemical analysis was apparently unaffected by the extract except oxalate in preventive protocol, and calcium, sodium, and potassium in curative protocol which were significantly highly excreted in treated rats compared to untreated animals. Crystalluria was characterized mostly by the presence of large quantities of CaOx monohydrate and CaOx dihydrate particles in untreated rats. However, crystalluria was mainly dominated by the presence of CaOx dihydrate particles with reduced size. The most apparent beneficial effect of Cynodon extract was seen in kidney tissues where reduced levels of CaOx deposition have been noticed especially in medullary and papillary sections from treated rats. We concluded that C. dactylon extract has beneficial effect in preventing and eliminating CaOx deposition into kidneys. Such findings provide a scientific explanation for its use in the

Interpreting trial results following use of different intention-to-treat approaches for preventing attrition bias: a meta-epidemiological study protocol

OpenAIRE

Dossing, Anna; Tarp, Simon; Furst, Daniel E; Gluud, Christian; Beyene, Joseph; Hansen, Bjarke B; Bliddal, Henning; Christensen, Robin

2014-01-01

Introduction When participants drop out of randomised clinical trials, as frequently happens, the intention-to-treat (ITT) principle does not apply, potentially leading to attrition bias. Data lost from patient dropout/lack of follow-up are statistically addressed by imputing, a procedure prone to bias. Deviations from the original definition of ITT are referred to as modified intention-to-treat (mITT). As yet, the impact of the potential bias associated with mITT has not been assessed. Our o...

Exchange-biased planar Hall effect sensor optimized for biosensor applications

DEFF Research Database (Denmark)

Damsgaard, Christian Danvad; Freitas, S.C.; Freitas, P.P.

2008-01-01

This article presents experimental investigations of exchange-biased Permalloy planar Hall effect sensor crosses with a fixed active area of w x w = 40 x 40 mu m(2) and Permalloy thicknesses of t = 20, 30, and 50 nm. It is shown that a single domain model describes the system well...

Approximate Bias Correction in Econometrics

OpenAIRE

James G. MacKinnon; Anthony A. Smith Jr.

1995-01-01

This paper discusses ways to reduce the bias of consistent estimators that are biased in finite samples. It is necessary that the bias function, which relates parameter values to bias, should be estimable by computer simulation or by some other method. If so, bias can be reduced or, in some cases that may not be unrealistic, even eliminated. In general, several evaluations of the bias function will be required to do this. Unfortunately, reducing bias may increase the variance, or even the mea...

A sequential sampling account of response bias and speed-accuracy tradeoffs in a conflict detection task.

Science.gov (United States)

Vuckovic, Anita; Kwantes, Peter J; Humphreys, Michael; Neal, Andrew

2014-03-01

Signal Detection Theory (SDT; Green & Swets, 1966) is a popular tool for understanding decision making. However, it does not account for the time taken to make a decision, nor why response bias might change over time. Sequential sampling models provide a way of accounting for speed-accuracy trade-offs and response bias shifts. In this study, we test the validity of a sequential sampling model of conflict detection in a simulated air traffic control task by assessing whether two of its key parameters respond to experimental manipulations in a theoretically consistent way. Through experimental instructions, we manipulated participants' response bias and the relative speed or accuracy of their responses. The sequential sampling model was able to replicate the trends in the conflict responses as well as response time across all conditions. Consistent with our predictions, manipulating response bias was associated primarily with changes in the model's Criterion parameter, whereas manipulating speed-accuracy instructions was associated with changes in the Threshold parameter. The success of the model in replicating the human data suggests we can use the parameters of the model to gain an insight into the underlying response bias and speed-accuracy preferences common to dynamic decision-making tasks. © 2013 American Psychological Association

A Systematic Review of Attention Biases in Opioid, Cannabis, Stimulant Use Disorders.

Science.gov (United States)

Zhang, Melvyn; Ying, Jiangbo; Wing, Tracey; Song, Guo; Fung, Daniel S S; Smith, Helen

2018-06-01

Background : Opiates, cannabis, and amphetamines are highly abused, and use of these substances are prevalent disorders. Psychological interventions are crucial given that they help individuals maintain abstinence following a lapse or relapse into substance use. Advances in experimental psychology have suggested that automatic attention biases might be responsible for relapse. Prior reviews have provided evidence for the presence of these biases in addictive disorders and the effectiveness of bias modification. However, the prior studies are limited, as they failed to include trials involving participants with these prevalent addictive disorders or have failed to adopt a systematic approach in evidence synthesis. Objectives : The primary aim of this current systematic review is to synthesise the current evidence for attention biases amongst opioid use, cannabis use, and stimulant use disorders. The secondary aim is to determine the efficacy of attention bias modification interventions and other addictions related outcomes. Methods : A search was conducted from November 2017 to January 2018 on PubMed, MEDLINE, Embase, PsycINFO, Science Direct, Cochrane Central, and Scopus. The selection process of the articles was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A qualitative synthesis was undertaken. Risk of bias was assessed using the Cochrane Risk of Bias tool. Results : Six randomised trials were identified. The evidence synthesized from these trials have provided strong evidence that attentional biases are present in opioid and stimulant use disorders. Evidence synthesis for other secondary outcome measures could not be performed given the heterogeneity in the measures reported and the limited number of trials. The risk of bias assessment for the included trials revealed a high risk of selection and attrition bias. Conclusions : This review demonstrates the potential need for interventions targeting attention

Attentional bias in smokers: exposure to dynamic smoking cues in contemporary movies.

Science.gov (United States)

Lochbuehler, Kirsten; Voogd, Hubert; Scholte, Ron H J; Engels, Rutger C M E

2011-04-01

Research has shown that smokers have an attentional bias for pictorial smoking cues. The objective of the present study was to examine whether smokers also have an attentional bias for dynamic smoking cues in contemporary movies and therefore fixate more quickly, more often and for longer periods of time on dynamic smoking cues than non-smokers. By drawing upon established methods for assessing attentional biases for pictorial cues, we aimed to develop a new method for assessing attentional biases for dynamic smoking cues. We examined smokers' and non-smokers' eye movements while watching a movie clip by using eye-tracking technology. The sample consisted of 16 smoking and 17 non-smoking university students. Our results confirm the results of traditional pictorial attentional bias research. Smokers initially directed their gaze more quickly towards smoking-related cues (p = 0.01), focusing on them more often (p = 0.05) and for a longer duration (p = 0.01) compared with non-smokers. Thus, smoking cues in movies directly affect the attention of smokers. These findings indicate that the effects of dynamic smoking cues, in addition to other environmental smoking cues, need to be taken into account in smoking cessation therapies in order to increase successful smoking cessation and to prevent relapses.

Is There Room for "Development" in Developmental Models of Information Processing Biases to Threat in Children and Adolescents?

Science.gov (United States)

Field, Andy P.; Lester, Kathryn J.

2010-01-01

Clinical and experimental theories assume that processing biases in attention and interpretation are a causal mechanism through which anxiety develops. Despite growing evidence that these processing biases are present in children and, therefore, develop long before adulthood, these theories ignore the potential role of child development. This…

A Bias and Variance Analysis for Multistep-Ahead Time Series Forecasting.

Science.gov (United States)

Ben Taieb, Souhaib; Atiya, Amir F

2016-01-01

Multistep-ahead forecasts can either be produced recursively by iterating a one-step-ahead time series model or directly by estimating a separate model for each forecast horizon. In addition, there are other strategies; some of them combine aspects of both aforementioned concepts. In this paper, we present a comprehensive investigation into the bias and variance behavior of multistep-ahead forecasting strategies. We provide a detailed review of the different multistep-ahead strategies. Subsequently, we perform a theoretical study that derives the bias and variance for a number of forecasting strategies. Finally, we conduct a Monte Carlo experimental study that compares and evaluates the bias and variance performance of the different strategies. From the theoretical and the simulation studies, we analyze the effect of different factors, such as the forecast horizon and the time series length, on the bias and variance components, and on the different multistep-ahead strategies. Several lessons are learned, and recommendations are given concerning the advantages, disadvantages, and best conditions of use of each strategy.

Sex Attracts: Investigating Individual Differences in Attentional Bias to Sexual Stimuli

Science.gov (United States)

Kagerer, Sabine; Wehrum, Sina; Klucken, Tim; Walter, Bertram; Vaitl, Dieter; Stark, Rudolf

2014-01-01

We investigated the impact of sexual stimuli and the influence of sexual motivation on the performance in a dot-probe task and a line-orientation task in a large sample of males and females. All pictures (neutral, erotic) were rated on the dimensions of valence, arousal, disgust, and sexual arousal. Additionally, questionnaires measuring sexual interest/desire/motivation were employed. The ratings of the sexual stimuli point to a successful picture selection because sexual arousal did not differ between the sexes. The stimuli were equally arousing for men and women. Higher scores in the employed questionnaires measuring sexual interest/desire/motivation led to higher sexual arousal ratings of the sex pictures. Attentional bias towards sex pictures was observed in both experimental tasks. The attentional biases measured by the dot-probe and the line-orientation task were moderately intercorrelated suggesting attentional bias as a possible marker for a sex-attention trait. Finally, only the sexual sensation seeking score correlated with the attentional biases of the two tasks. Future research is needed to increase the predictive power of these indirect measures of sexual interest. PMID:25238545

Music for a Brighter World: Brightness Judgment Bias by Musical Emotion.

Science.gov (United States)

Bhattacharya, Joydeep; Lindsen, Job P

2016-01-01

A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.

Effective bias removal for fringe projection profilometry using the dual-tree complex wavelet transform.

Science.gov (United States)

Ng, William Wai-Lam; Lun, Daniel Pak-Kong

2012-08-20

When reconstructing the three-dimensional (3D) object height profile using the fringe projection profilometry (FPP) technique, the light intensity reflected from the object surface can yield abruptly changing bias in the captured fringe image, which leads to severe reconstruction error. The traditional approach tries to remove the bias by suppressing the zero spectrum of the fringe image. It is based on the assumption that the aliasing between the frequency spectrum of the bias, which is around the zero frequency, and the frequency spectrum of the fringe is negligible. This, however, is not the case in practice. In this paper, we propose a novel (to our knowledge) technique to eliminate the bias in the fringe image using the dual-tree complex wavelet transform (DT-CWT). The new approach successfully identifies the features of bias, fringe, and noise in the DT-CWT domain, which allows the bias to be effectively extracted from a noisy fringe image. Experimental results show that the proposed algorithm is superior to the traditional methods and facilitates accurate reconstruction of objects' 3D models.

A Diffusion Model Analysis of Decision Biases Affecting Delayed Recognition of Emotional Stimuli

Science.gov (United States)

Bowen, Holly J.; Spaniol, Julia; Patel, Ronak; Voss, Andreas

2016-01-01

Previous empirical work suggests that emotion can influence accuracy and cognitive biases underlying recognition memory, depending on the experimental conditions. The current study examines the effects of arousal and valence on delayed recognition memory using the diffusion model, which allows the separation of two decision biases thought to underlie memory: response bias and memory bias. Memory bias has not been given much attention in the literature but can provide insight into the retrieval dynamics of emotion modulated memory. Participants viewed emotional pictorial stimuli; half were given a recognition test 1-day later and the other half 7-days later. Analyses revealed that emotional valence generally evokes liberal responding, whereas high arousal evokes liberal responding only at a short retention interval. The memory bias analyses indicated that participants experienced greater familiarity with high-arousal compared to low-arousal items and this pattern became more pronounced as study-test lag increased; positive items evoke greater familiarity compared to negative and this pattern remained stable across retention interval. The findings provide insight into the separate contributions of valence and arousal to the cognitive mechanisms underlying delayed emotion modulated memory. PMID:26784108

MARRT: Medial Axis biased rapidly-exploring random trees

KAUST Repository

Denny, Jory

2014-05-01

© 2014 IEEE. Motion planning is a difficult and widely studied problem in robotics. Current research aims not only to find feasible paths, but to ensure paths have certain properties, e.g., shortest or safest paths. This is difficult for current state-of-the-art sampling-based techniques as they typically focus on simply finding any path. Despite this difficulty, sampling-based techniques have shown great success in planning for a wide range of applications. Among such planners, Rapidly-Exploring Random Trees (RRTs) search the planning space by biasing exploration toward unexplored regions. This paper introduces a novel RRT variant, Medial Axis RRT (MARRT), which biases tree exploration to the medial axis of free space by pushing all configurations from expansion steps towards the medial axis. We prove that this biasing increases the tree\\'s clearance from obstacles. Improving obstacle clearance is useful where path safety is important, e.g., path planning for robots performing tasks in close proximity to the elderly. Finally, we experimentally analyze MARRT, emphasizing its ability to effectively map difficult passages while increasing obstacle clearance, and compare it to contemporary RRT techniques.

Learning bias, cultural evolution of language, and the biological evolution of the language faculty.

Science.gov (United States)

Smith, Kenny

2011-04-01

The biases of individual language learners act to determine the learnability and cultural stability of languages: learners come to the language learning task with biases which make certain linguistic systems easier to acquire than others. These biases are repeatedly applied during the process of language transmission, and consequently should effect the types of languages we see in human populations. Understanding the cultural evolutionary consequences of particular learning biases is therefore central to understanding the link between language learning in individuals and language universals, common structural properties shared by all the world’s languages. This paper reviews a range of models and experimental studies which show that weak biases in individual learners can have strong effects on the structure of socially learned systems such as language, suggesting that strong universal tendencies in language structure do not require us to postulate strong underlying biases or constraints on language learning. Furthermore, understanding the relationship between learner biases and language design has implications for theories of the evolution of those learning biases: models of gene-culture coevolution suggest that, in situations where a cultural dynamic mediates between properties of individual learners and properties of language in this way, biological evolution is unlikely to lead to the emergence of strong constraints on learning.

Beyond attentional bias: a perceptual bias in a dot-probe task.

Science.gov (United States)

Bocanegra, Bruno R; Huijding, Jorg; Zeelenberg, René

2012-12-01

Previous dot-probe studies indicate that threat-related face cues induce a bias in spatial attention. Independently of spatial attention, a recent psychophysical study suggests that a bilateral fearful face cue improves low spatial-frequency perception (LSF) and impairs high spatial-frequency perception (HSF). Here, we combine these separate lines of research within a single dot-probe paradigm. We found that a bilateral fearful face cue, compared with a bilateral neutral face cue, speeded up responses to LSF targets and slowed down responses to HSF targets. This finding is important, as it shows that emotional cues in dot-probe tasks not only bias where information is preferentially processed (i.e., an attentional bias in spatial location), but also bias what type of information is preferentially processed (i.e., a perceptual bias in spatial frequency). PsycINFO Database Record (c) 2012 APA, all rights reserved.

Simulating publication bias

DEFF Research Database (Denmark)

Paldam, Martin

is censoring: selection by the size of estimate; SR3 selects the optimal combination of fit and size; and SR4 selects the first satisficing result. The last four SRs are steered by priors and result in bias. The MST and the FAT-PET have been developed for detection and correction of such bias. The simulations......Economic research typically runs J regressions for each selected for publication – it is often selected as the ‘best’ of the regressions. The paper examines five possible meanings of the word ‘best’: SR0 is ideal selection with no bias; SR1 is polishing: selection by statistical fit; SR2...... are made by data variation, while the model is the same. It appears that SR0 generates narrow funnels much at odds with observed funnels, while the other four funnels look more realistic. SR1 to SR4 give the mean a substantial bias that confirms the prior causing the bias. The FAT-PET MRA works well...

A study on investors’ personality characteristics and behavioral biases: Conservatism bias and availability bias in the Tehran Stock Exchange

Directory of Open Access Journals (Sweden)

Mahmoud Moradi

2013-04-01

Full Text Available Most economic and finance theories are based on the assumption that during economic decision making, people would act totally rational and consider all available information. Nevertheless, behavioral finance focuses on studying of the role of psychological factors on economic participants’ behavior. The study shows that in real-world environment, people are influenced by emotional and cognitive errors and may make irrational financial decisions. In many cases, the participants of financial markets are not aware of their talents for error in decision making, so they are dissatisfied with their investments by considering some behavioral biases decisions. These decisions may often yield undesirable outcomes, which could influence economy, significantly. This paper presents a survey on the relationship between personality dimensions with behavioral biases and availability bias among investment managers in the Tehran Stock Exchange using SPSS software, descriptive and inferential statistics. The necessary data are collected through questionnaire and they are analyzed using some statistical tests. The preliminary results indicate that there is a relationship between personality dimensions and behavioral biases like conservatism bias and availability bias among the investors in the Tehran Stock Exchange.

Visual attentional bias for food in adolescents with binge-eating disorder.

Science.gov (United States)

Schmidt, Ricarda; Lüthold, Patrick; Kittel, Rebekka; Tetzlaff, Anne; Hilbert, Anja

2016-09-01

Evidence suggests that adults with binge-eating disorder (BED) are prone of having their attention interfered by food cues, and that food-related attentional biases are associated with calorie intake and eating disorder psychopathology. For adolescents with BED experimental evidence on attentional processing of food cues is lacking. Using eye-tracking and a visual search task, the present study examined visual orienting and disengagement processes of food in youth with BED. Eye-movement data and reaction times were recorded in 25 adolescents (12-20 years) with BED and 25 controls (CG) individually matched for sex, age, body mass index, and socio-economic status. During a free exploration paradigm, the BED group showed a greater gaze duration bias for food images than the CG. Groups did not differ in gaze direction biases. In a visual search task, the BED group showed a greater detection bias for food targets than the CG. Group differences were more pronounced for personally attractive than unattractive food images. Regarding clinical associations, only in the BED group the gaze duration bias for food was associated with increased hunger and lower body mass index, and the detection bias for food targets was associated with greater reward sensitivity. The study provided first evidence of an attentional bias to food in adolescents with BED. However, more research is needed for further specifying disengagement and orienting processes in adolescent BED, including overt and covert attention, and their prospective associations with binge-eating behaviors and associated psychopathology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Publication bias in studies of an applied behavior-analytic intervention: an initial analysis.

Science.gov (United States)

Sham, Elyssa; Smith, Tristram

2014-01-01

Publication bias arises when studies with favorable results are more likely to be reported than are studies with null findings. If this bias occurs in studies with single-subject experimental designs(SSEDs) on applied behavior-analytic (ABA) interventions, it could lead to exaggerated estimates of intervention effects. Therefore, we conducted an initial test of bias by comparing effect sizes, measured by percentage of nonoverlapping data (PND), in published SSED studies (n=21) and unpublished dissertations (n=10) on 1 well-established intervention for children with autism, pivotal response treatment (PRT). Although published and unpublished studies had similar methodologies, the mean PND in published studies was 22% higher than in unpublished studies, 95% confidence interval (4%, 38%). Even when unpublished studies are included, PRT appeared to be effective (PNDM=62%). Nevertheless, the disparity between published and unpublished studies suggests a need for further assessment of publication bias in the ABA literature.

Media bias under direct and indirect government control: when is the bias smaller?

OpenAIRE

Abhra Roy

2015-01-01

We present an analytical framework to compare media bias under direct and indirect government control. In this context, we show that direct control can lead to a smaller bias and higher welfare than indirect control. We further show that the size of the advertising market affects media bias only under direct control. Media bias, under indirect control, is not affected by the size of the advertising market.

Self-biased cobalt ferrite nanocomposites for microwave applications

International Nuclear Information System (INIS)

Hannour, Abdelkrim; Vincent, Didier; Kahlouche, Faouzi; Tchangoulian, Ardaches; Neveu, Sophie; Dupuis, Vincent

2014-01-01

Oriented CoFe 2 O 4 nanoparticles, dispersed in polymethyl methacrylate (PMMA) matrix, were fabricated by magnetophoretic deposition of functionalized nanocolloidal cobalt ferrite particles into porous alumina membrane. Their magnetic behavior exhibits an out-of-plane easy axis with a large remanent magnetization and coercitivity. This orientation allows high effective internal magnetic anisotropy that contributes to the permanent bias along the wire axis. The microwave studies reveal a ferromagnetic resonance at 46.5 and 49.5 GHz, depending on the filling ratio of the membrane. Ansoft High Frequency Structure Simulator (Ansoft HFSS) simulations are in good agreement with experimental results. Such nanocomposite is presented as one of the promising candidates for microwave devices (circulators, isolators, noise suppressors etc.). - Highlights: • Oriented magnetic CoFe 2 O 4 nanoparticles were fabricated by magnetophoretic deposition of functionalized cobalt ferrite particles into porous alumina membrane. • The nanocomposite obtained presents an out-of-plane easy axis with a large remanent magnetization and coercitivity. • The high effective internal magnetic anisotropy contributes to the permanent bias along the wire axis. • The frequency ferromagnetic resonance ranges from 46.5 to 49.5 GHz, depending on the filling ratio of the membrane. • We have obtained a good agreement between Ansoft High Frequency Structure Simulator simulations and experimental results

Large-scale galaxy bias

Science.gov (United States)

Desjacques, Vincent; Jeong, Donghui; Schmidt, Fabian

2018-02-01

This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a detailed derivation of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which include the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in its general form, which elucidates the physical meaning of the bias parameters, and a detailed description of the connection between bias parameters and galaxy statistics. We then review the excursion-set formalism and peak theory which provide predictions for the values of the bias parameters. In the remainder of the review, we consider the generalizations of galaxy bias required in the presence of various types of cosmological physics that go beyond pressureless matter with adiabatic, Gaussian initial conditions: primordial non-Gaussianity, massive neutrinos, baryon-CDM isocurvature perturbations, dark energy, and modified gravity. Finally, we discuss how the description of galaxy bias in the galaxies' rest frame is related to clustering statistics measured from the observed angular positions and redshifts in actual galaxy catalogs.

The (neurocognitive mechanisms behind attention bias modification in anxiety: Proposals based on theoretical accounts of attentional bias

Directory of Open Access Journals (Sweden)

Alexandre eHeeren

2013-04-01

Full Text Available Recently, researchers have investigated the causal nature of attentional bias for threat (AB in the maintenance of anxiety disorders by experimentally manipulating it. They found that training anxious individuals to attend to nonthreat stimuli reduces AB, which, in turn, reduces anxiety. This effect supports the hypothesis that AB can causally impact the maintenance of anxiety. At a fundamental level, however, uncertainty still abounds regarding the nature of the processes that mediate this effect. In the present paper, we propose that two contrasting approaches may be derived from theoretical accounts of AB. According to a first class of models, called the valence-specific bias models, modifying AB requires the modification of valence-specific attentional selectivity. According to a second class of models, called the attention control models, modifying AB requires the modification of attention control, driven by the recruitment of the dorsolateral prefrontal cortex. We formulate a series of specific predictions, to provide suggestions to trial these two approaches one against the other. This knowledge is critical for understanding the mechanisms of AB in anxiety disorders, which bares important clinical implications.

Direct Experimental Evidence of Hole Trapping in Negative Bias Temperature Instability

International Nuclear Information System (INIS)

Ji Xiao-Li; Liao Yi-Ming; Yan Feng; Shi Yi; Zhang Guan; Guo Qiang

2011-01-01

Negative bias temperature instability (NBTI) in ultrathin-plasma-nitrided-oxide (PNO) based p-type metal-oxide-semiconductor field effect transistors (pMOSFETs) is investigated at temperatures ranging from 220K to 470K. It is found that the threshold voltage V T degradation below 290 K is dominated by the hole trapping process. Further studies unambiguously show that this process is unnecessarily related to nitrogen but the incorporation of nitrogen in the gate dielectric increases the probability of hole trapping in the NBTI process as it introduces extra trap states located in the upper half of the Si band gap. The possible hole trapping mechanism in NBTI stressed PNO pMOSFETs is suggested by taking account of oxygen and nitrogen related trap centers. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

High and far: biases in the location of protected areas.

Directory of Open Access Journals (Sweden)

Lucas N Joppa

Full Text Available BACKGROUND: About an eighth of the earth's land surface is in protected areas (hereafter "PAs", most created during the 20(th century. Natural landscapes are critical for species persistence and PAs can play a major role in conservation and in climate policy. Such contributions may be harder than expected to implement if new PAs are constrained to the same kinds of locations that PAs currently occupy. METHODOLOGY/PRINCIPAL FINDINGS: Quantitatively extending the perception that PAs occupy "rock and ice", we show that across 147 nations PA networks are biased towards places that are unlikely to face land conversion pressures even in the absence of protection. We test each country's PA network for bias in elevation, slope, distances to roads and cities, and suitability for agriculture. Further, within each country's set of PAs, we also ask if the level of protection is biased in these ways. We find that the significant majority of national PA networks are biased to higher elevations, steeper slopes and greater distances to roads and cities. Also, within a country, PAs with higher protection status are more biased than are the PAs with lower protection statuses. CONCLUSIONS/SIGNIFICANCE: In sum, PAs are biased towards where they can least prevent land conversion (even if they offer perfect protection. These globally comprehensive results extend findings from nation-level analyses. They imply that siting rules such as the Convention on Biological Diversity's 2010 Target [to protect 10% of all ecoregions] might raise PA impacts if applied at the country level. In light of the potential for global carbon-based payments for avoided deforestation or REDD, these results suggest that attention to threat could improve outcomes from the creation and management of PAs.

Long-branch attraction bias and inconsistency in Bayesian phylogenetics.

Science.gov (United States)

Kolaczkowski, Bryan; Thornton, Joseph W

2009-12-09

Bayesian inference (BI) of phylogenetic relationships uses the same probabilistic models of evolution as its precursor maximum likelihood (ML), so BI has generally been assumed to share ML's desirable statistical properties, such as largely unbiased inference of topology given an accurate model and increasingly reliable inferences as the amount of data increases. Here we show that BI, unlike ML, is biased in favor of topologies that group long branches together, even when the true model and prior distributions of evolutionary parameters over a group of phylogenies are known. Using experimental simulation studies and numerical and mathematical analyses, we show that this bias becomes more severe as more data are analyzed, causing BI to infer an incorrect tree as the maximum a posteriori phylogeny with asymptotically high support as sequence length approaches infinity. BI's long branch attraction bias is relatively weak when the true model is simple but becomes pronounced when sequence sites evolve heterogeneously, even when this complexity is incorporated in the model. This bias--which is apparent under both controlled simulation conditions and in analyses of empirical sequence data--also makes BI less efficient and less robust to the use of an incorrect evolutionary model than ML. Surprisingly, BI's bias is caused by one of the method's stated advantages--that it incorporates uncertainty about branch lengths by integrating over a distribution of possible values instead of estimating them from the data, as ML does. Our findings suggest that trees inferred using BI should be interpreted with caution and that ML may be a more reliable framework for modern phylogenetic analysis.

Apparatus bias and place conditioning with ethanol in mice.

Science.gov (United States)

Cunningham, Christopher L; Ferree, Nikole K; Howard, MacKenzie A

2003-12-01

Although the distinction between "biased" and "unbiased" is generally recognized as an important methodological issue in place conditioning, previous studies have not adequately addressed the distinction between a biased/unbiased apparatus and a biased/unbiased stimulus assignment procedure. Moreover, a review of the recent literature indicates that many reports (70% of 76 papers published in 2001) fail to provide adequate information about apparatus bias. This issue is important because the mechanisms underlying a drug's effect in the place-conditioning procedure may differ depending on whether the apparatus is biased or unbiased. The present studies were designed to assess the impact of apparatus bias and stimulus assignment procedure on ethanol-induced place conditioning in mice (DBA/2 J). A secondary goal was to compare various dependent variables commonly used to index conditioned place preference. Apparatus bias was manipulated by varying the combination of tactile (floor) cues available during preference tests. Experiment 1 used an unbiased apparatus in which the stimulus alternatives were equally preferred during a pre-test as indicated by the group average. Experiment 2 used a biased apparatus in which one of the stimuli was strongly preferred by most mice (mean % time on cue = 67%) during the pre-test. In both studies, the stimulus paired with drug (CS+) was assigned randomly (i.e., an "unbiased" stimulus assignment procedure). Experimental mice received four pairings of CS+ with ethanol (2 g/kg, i.p.) and four pairings of the alternative stimulus (CS-) with saline; control mice received saline on both types of trial. Each experiment concluded with a 60-min choice test. With the unbiased apparatus (experiment 1), significant place conditioning was obtained regardless of whether drug was paired with the subject's initially preferred or non-preferred stimulus. However, with the biased apparatus (experiment 2), place conditioning was apparent only when

Large-scale galaxy bias

Science.gov (United States)

Jeong, Donghui; Desjacques, Vincent; Schmidt, Fabian

2018-01-01

Here, we briefly introduce the key results of the recent review (arXiv:1611.09787), whose abstract is as following. This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a detailed derivation of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which include the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in its general form, which elucidates the physical meaning of the bias parameters, and a detailed description of the connection between bias parameters and galaxy (or halo) statistics. We then review the excursion set formalism and peak theory which provide predictions for the values of the bias parameters. In the remainder of the review, we consider the generalizations of galaxy bias required in the presence of various types of cosmological physics that go beyond pressureless matter with adiabatic, Gaussian initial conditions: primordial non-Gaussianity, massive neutrinos, baryon-CDM isocurvature perturbations, dark energy, and modified gravity. Finally, we discuss how the description of galaxy bias in the galaxies' rest frame is related to clustering statistics measured from the observed angular positions and redshifts in actual galaxy catalogs.

Electrocortical measures of information processing biases in social anxiety disorder: A review.

Science.gov (United States)

Harrewijn, Anita; Schmidt, Louis A; Westenberg, P Michiel; Tang, Alva; van der Molen, Melle J W

2017-10-01

Social anxiety disorder (SAD) is characterized by information processing biases, however, their underlying neural mechanisms remain poorly understood. The goal of this review was to give a comprehensive overview of the most frequently studied EEG spectral and event-related potential (ERP) measures in social anxiety during rest, anticipation, stimulus processing, and recovery. A Web of Science search yielded 35 studies reporting on electrocortical measures in individuals with social anxiety or related constructs. Social anxiety was related to increased delta-beta cross-frequency correlation during anticipation and recovery, and information processing biases during early processing of faces (P1) and errors (error-related negativity). These electrocortical measures are discussed in relation to the persistent cycle of information processing biases maintaining SAD. Future research should further investigate the mechanisms of this persistent cycle and study the utility of electrocortical measures in early detection, prevention, treatment and endophenotype research. Copyright © 2017 Elsevier B.V. All rights reserved.

Information environment, behavioral biases, and home bias in analysts’ recommendations

DEFF Research Database (Denmark)

Farooq, Omar; Taouss, Mohammed

2012-01-01

Can information environment of a firm explain home bias in analysts’ recommendations? Can the extent of agency problems explain optimism difference between foreign and local analysts? This paper answers these questions by documenting the effect of information environment on home bias in analysts’...

Low-bias negative differential conductance controlled by electrode separation

International Nuclear Information System (INIS)

Yi Xiao-Hua; Liu Ran; Bi Jun-Jie; Jiao Yang; Wang Chuan-Kui; Li Zong-Liang

2016-01-01

The electronic transport properties of a single thiolated arylethynylene molecule with 9,10-dihydroanthracene core, denoted as TADHA, is studied by using non-equilibrium Green’s function formalism combined with ab initio calculations. The numerical results show that the TADHA molecule exhibits excellent negative differential conductance (NDC) behavior at lower bias regime as probed experimentally. The NDC behavior of TADHA molecule originates from the Stark effect of the applied bias voltage, by which the highest occupied molecular orbital (HOMO) and the HOMO-1 are pulled apart and become localized. The NDC behavior of TADHA molecular system is tunable by changing the electrode distance. Shortening the electrode separation can enhance the NDC effect which is attributed to the possible increase of coupling between the two branches of TADHA molecule. (paper)

Exchange bias theory

International Nuclear Information System (INIS)

Kiwi, Miguel

2001-01-01

Research on the exchange bias (EB) phenomenon has witnessed a flurry of activity during recent years, which stems from its use in magnetic sensors and as stabilizers in magnetic reading heads. EB was discovered in 1956 but it attracted only limited attention until these applications, closely related to giant magnetoresistance, were developed during the last decade. In this review, I initially give a short introduction, listing the most salient experimental results and what is required from an EB theory. Next, I indicate some of the obstacles in the road towards a satisfactory understanding of the phenomenon. The main body of the text reviews and critically discusses the activity that has flourished, mainly during the last 5 years, in the theoretical front. Finally, an evaluation of the progress made, and a critical assessment as to where we stand nowadays along the road to a satisfactory theory, is presented

Model for an irreversible bias current in the superconducting qubit measurement process

International Nuclear Information System (INIS)

Hutchinson, G. D.; Williams, D. A.; Holmes, C. A.; Stace, T. M.; Spiller, T. P.; Barrett, S. D.; Milburn, G. J.; Hasko, D. G.

2006-01-01

The superconducting charge-phase ''quantronium'' qubit is considered in order to develop a model for the measurement process used in the experiment of Vion et al. [Science 296, 886 (2002)]. For this model we propose a method for including the bias current in the readout process in a fundamentally irreversible way, which to first order is approximated by the Josephson junction tilted-washboard potential phenomenology. The decohering bias current is introduced in the form of a Lindblad operator and the Wigner function for the current-biased readout Josephson junction is derived and analyzed. During the readout current pulse used in the quantronium experiment we find that the coherence of the qubit initially prepared in a symmetric superposition state is lost at a time of 0.2 ns after the bias current pulse has been applied, a time scale that is much shorter than the experimental readout time. Additionally we look at the effect of Johnson-Nyquist noise with zero mean from the current source during the qubit manipulation and show that the decoherence due to the irreversible bias current description is an order of magnitude smaller than that found through adding noise to the reversible tilted-washboard potential model. Our irreversible bias current model is also applicable to persistent-current-based qubits where the state is measured according to its flux via a small-inductance direct-current superconducting quantum interference device

Application of Photocurrent Model on Polymer Solar Cells Under Forward Bias Stress

DEFF Research Database (Denmark)

Rizzo, Antonio; Torto, Lorenzo; Wrachien, Nicola

2017-01-01

We performed a constant current stress at forward bias on organic heterojunction solar cells. We measured current voltage curves in both dark and light at each stress step to calculate the photocurrent. An existing model applied to photocurrent experimental data allows the estimation of several...

A Dynamic Bayesian Observer Model Reveals Origins of Bias in Visual Path Integration.

Science.gov (United States)

Lakshminarasimhan, Kaushik J; Petsalis, Marina; Park, Hyeshin; DeAngelis, Gregory C; Pitkow, Xaq; Angelaki, Dora E

2018-06-20

Path integration is a strategy by which animals track their position by integrating their self-motion velocity. To identify the computational origins of bias in visual path integration, we asked human subjects to navigate in a virtual environment using optic flow and found that they generally traveled beyond the goal location. Such a behavior could stem from leaky integration of unbiased self-motion velocity estimates or from a prior expectation favoring slower speeds that causes velocity underestimation. Testing both alternatives using a probabilistic framework that maximizes expected reward, we found that subjects' biases were better explained by a slow-speed prior than imperfect integration. When subjects integrate paths over long periods, this framework intriguingly predicts a distance-dependent bias reversal due to buildup of uncertainty, which we also confirmed experimentally. These results suggest that visual path integration in noisy environments is limited largely by biases in processing optic flow rather than by leaky integration. Copyright © 2018 Elsevier Inc. All rights reserved.

Operator Bias in the Estimation of Arc Efficiency in Gas Tungsten Arc Welding

Directory of Open Access Journals (Sweden)

Fredrik Sikström

2015-03-01

Full Text Available In this paper the operator bias in the measurement process of arc efficiency in stationary direct current electrode negative gas tungsten arc welding is discussed. An experimental study involving 15 operators (enough to reach statistical significance has been carried out with the purpose to estimate the arc efficiency from a specific procedure for calorimetric experiments. The measurement procedure consists of three manual operations which introduces operator bias in the measurement process. An additional relevant experiment highlights the consequences of estimating the arc voltage by measuring the potential between the terminals of the welding power source instead of measuring the potential between the electrode contact tube and the workpiece. The result of the study is a statistical evaluation of the operator bias influence on the estimate, showing that operator bias is negligible in the estimate considered here. On the contrary the consequences of neglecting welding leads voltage drop results in a significant under estimation of the arc efficiency.

Developmental reversals in risky decision making: intelligence agents show larger decision biases than college students.

Science.gov (United States)

Reyna, Valerie F; Chick, Christina F; Corbin, Jonathan C; Hsia, Andrew N

2014-01-01

Intelligence agents make risky decisions routinely, with serious consequences for national security. Although common sense and most theories imply that experienced intelligence professionals should be less prone to irrational inconsistencies than college students, we show the opposite. Moreover, the growth of experience-based intuition predicts this developmental reversal. We presented intelligence agents, college students, and postcollege adults with 30 risky-choice problems in gain and loss frames and then compared the three groups' decisions. The agents not only exhibited larger framing biases than the students, but also were more confident in their decisions. The postcollege adults (who were selected to be similar to the students) occupied an interesting middle ground, being generally as biased as the students (sometimes more biased) but less biased than the agents. An experimental manipulation testing an explanation for these effects, derived from fuzzy-trace theory, made the students look as biased as the agents. These results show that, although framing biases are irrational (because equivalent outcomes are treated differently), they are the ironical output of cognitively advanced mechanisms of meaning making.

Testing human sperm chemotaxis: how to detect biased motion in population assays.

Directory of Open Access Journals (Sweden)

Leah Armon

Full Text Available Biased motion of motile cells in a concentration gradient of a chemoattractant is frequently studied on the population level. This approach has been particularly employed in human sperm chemotactic assays, where the fraction of responsive cells is low and detection of biased motion depends on subtle differences. In these assays, statistical measures such as population odds ratios of swimming directions can be employed to infer chemotactic performance. Here, we report on an improved method to assess statistical significance of experimentally determined odds ratios and discuss the strong impact of data correlations that arise from the directional persistence of sperm swimming.

Observational drawing biases are predicted by biases in perception: Empirical support of the misperception hypothesis of drawing accuracy with respect to two angle illusions.

Science.gov (United States)

Ostrofsky, Justin; Kozbelt, Aaron; Cohen, Dale J

2015-01-01

We tested the misperception hypothesis of drawing errors, which states that drawing accuracy is strongly influenced by the perceptual encoding of a to-be-drawn stimulus. We used a highly controlled experimental paradigm in which nonartist participants made perceptual judgements and drawings of angles under identical stimulus exposure conditions. Experiment 1 examined the isosceles/scalene triangle angle illusion; congruent patterns of bias in the perception and drawing tasks were found for 40 and 60° angles, but not for 20 or 80° angles, providing mixed support for the misperception hypothesis. Experiment 2 examined shape constancy effects with respect to reproductions of single acute or obtuse angles; congruent patterns of bias in the perception and drawing tasks were found across a range of angles from 29 to 151°, providing strong support for the misperception hypothesis. In both experiments, perceptual and drawing biases were positively correlated. These results are largely consistent with the misperception hypothesis, suggesting that inaccurate perceptual encoding of angles is an important reason that nonartists err in drawing angles from observation.

Interpreting trial results following use of different intention-to-treat approaches for preventing attrition bias: a meta-epidemiological study protocol.

Science.gov (United States)

Dossing, Anna; Tarp, Simon; Furst, Daniel E; Gluud, Christian; Beyene, Joseph; Hansen, Bjarke B; Bliddal, Henning; Christensen, Robin

2014-09-26

When participants drop out of randomised clinical trials, as frequently happens, the intention-to-treat (ITT) principle does not apply, potentially leading to attrition bias. Data lost from patient dropout/lack of follow-up are statistically addressed by imputing, a procedure prone to bias. Deviations from the original definition of ITT are referred to as modified intention-to-treat (mITT). As yet, the impact of the potential bias associated with mITT has not been assessed. Our objective is to investigate potential bias and disadvantages of performing mITT and evaluate possible concerns when executing different mITT approaches in meta-analyses. Using meta-epidemiology on randomised trials considered less prone to bias (ie, good internal validity) and assessing biological or targeted agents in patients with rheumatoid arthritis, we will meta-analyse data from 10 biological and targeted drugs based on collections of trials that would correspond to 10 individual meta-analyses. This study will enhance transparency for evaluating mITT treatment effects described in meta-analyses. The intended audience will include healthcare researchers, policymakers and clinicians. Results of the study will be disseminated by peer-review publication. In PROSPERO CRD42013006702, 11. December 2013. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Links among available integral benchmarks and differential date evaluations, computational biases and uncertainties, and nuclear criticality safety biases on potential MOX production throughput

International Nuclear Information System (INIS)

Goluoglu, S.; Hopper, C.M.

2004-01-01

Through the use of Oak Ridge National Laboratory's recently developed and applied sensitivity and uncertainty computational analysis techniques, this paper presents the relevance and importance of available and needed integral benchmarks and differential data evaluations impacting potential MOX production throughput determinations relative to low-moderated MOX fuel blending operations. The relevance and importance in the availability of or need for critical experiment benchmarks and data evaluations are presented in terms of computational biases as influenced by computational and experimental sensitivities and uncertainties relative to selected MOX production powder blending processes. Recent developments for estimating the safe margins of subcriticality for assuring nuclear criticality safety for process approval are presented. In addition, the impact of the safe margins (due to computational biases and uncertainties) on potential MOX production throughput will also be presented. (author)

Profile Control by Biased Electrodes in Large Diameter RF Produced Pl asma

Science.gov (United States)

Shinohara, Shunjiro; Matsuoka, Norikazu; Yoshinaka, Toshiro

1998-10-01

Control of the plasma profile has been carried out, using the voltage biasing method in the large diameter (45 cm) RF (radio frequency) produced plasma in the presence of the uniform magnetic field (less than 1200 G). Under the low filling pressure condition of 0.16 mTorr, changing the biasing voltages to the three individual end plates with concentric circular ring shapes, the radial electron density (about 10^10 cm-3) profile could be changed from the hollow to the peaked one. On the contrary, the nearly flat electron temperature (several eV) profile did not change appreciably. The azimuthal rotation velocity measured by the Mach probe, i.e. directional probe, showed the different radial profiles (but nearly uniform along the axis) depending on the biasing voltage. This velocity became slower with the low magnetic field (less than 200 G) or in the higher pressure regime up to 20 mTorr with the higher electron density. The experimental results by other biasing methods will also be presented.

Proportional hazards model with varying coefficients for length-biased data.

Science.gov (United States)

Zhang, Feipeng; Chen, Xuerong; Zhou, Yong

2014-01-01

Length-biased data arise in many important applications including epidemiological cohort studies, cancer prevention trials and studies of labor economics. Such data are also often subject to right censoring due to loss of follow-up or the end of study. In this paper, we consider a proportional hazards model with varying coefficients for right-censored and length-biased data, which is used to study the interact effect nonlinearly of covariates with an exposure variable. A local estimating equation method is proposed for the unknown coefficients and the intercept function in the model. The asymptotic properties of the proposed estimators are established by using the martingale theory and kernel smoothing techniques. Our simulation studies demonstrate that the proposed estimators have an excellent finite-sample performance. The Channing House data is analyzed to demonstrate the applications of the proposed method.

Sex attracts: investigating individual differences in attentional bias to sexual stimuli.

Directory of Open Access Journals (Sweden)

Sabine Kagerer

Full Text Available We investigated the impact of sexual stimuli and the influence of sexual motivation on the performance in a dot-probe task and a line-orientation task in a large sample of males and females. All pictures (neutral, erotic were rated on the dimensions of valence, arousal, disgust, and sexual arousal. Additionally, questionnaires measuring sexual interest/desire/motivation were employed. The ratings of the sexual stimuli point to a successful picture selection because sexual arousal did not differ between the sexes. The stimuli were equally arousing for men and women. Higher scores in the employed questionnaires measuring sexual interest/desire/motivation led to higher sexual arousal ratings of the sex pictures. Attentional bias towards sex pictures was observed in both experimental tasks. The attentional biases measured by the dot-probe and the line-orientation task were moderately intercorrelated suggesting attentional bias as a possible marker for a sex-attention trait. Finally, only the sexual sensation seeking score correlated with the attentional biases of the two tasks. Future research is needed to increase the predictive power of these indirect measures of sexual interest.

Music for a Brighter World: Brightness Judgment Bias by Musical Emotion.

Directory of Open Access Journals (Sweden)

Joydeep Bhattacharya

Full Text Available A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.

A multiple case study approach to work stress prevention in Europe

NARCIS (Netherlands)

Kompier, M.A.J.; Cooper, C.L.; Geurts, S.A.E.; Cooper, C.L.

2013-01-01

Work stress has become a major issue among European employees. The current practice of its prevention seems disappointing, as work stress prevention programmes are predominantly reactive and biased to the individual. The lack of organization-level intervention studies is a barrier to progress in

A multiple case study approach to work stress prevention in Europe

NARCIS (Netherlands)

Kompier, M.A.J.; Cooper, C.L.; Geurts, S.A.E.

2000-01-01

Work stress has become a major issue among European employees. The current practice of its prevention seems disappointing, as work stress prevention programmes are predominantly reactive and biased to the individual. The lack of organization-level intervention studies is a barrier to progress in

Bond and Equity Home Bias and Foreign Bias: an International Study

OpenAIRE

VanPée, Rosanne; De Moor, Lieven

2012-01-01

In this paper we explore tentatively and formally the differences between bond and equity home bias and foreign bias based on one large scale dataset including developed and emerging markets for the period 2001 to 2010. We set the stage by tentatively and formally linking the diversion of bond and equity home bias in OECD countries to the increasing public debt issues under the form of government bonds i.e. the supply-driven argument. Unlike Fidora et al. (2007) we do not find that exchange r...

Alcohol cognitive bias modification training for problem drinkers over the web.

Science.gov (United States)

Wiers, Reinout W; Houben, Katrijn; Fadardi, Javad S; van Beek, Paul; Rhemtulla, Mijke; Cox, W Miles

2015-01-01

Following successful outcomes of cognitive bias modification (CBM) programs for alcoholism in clinical and community samples, the present study investigated whether different varieties of CBM (attention control training and approach-bias re-training) could be delivered successfully in a fully automated web-based way and whether these interventions would help self-selected problem drinkers to reduce their drinking. Participants were recruited through online advertising, which resulted in 697 interested participants, of whom 615 were screened in. Of the 314 who initiated training, 136 completed a pretest, four sessions of computerized training and a posttest. Participants were randomly assigned to one of four experimental conditions (attention control or one of three varieties of approach-bias re-training) or a sham-training control condition. The general pattern of findings was that participants in all conditions (including participants in the control-training condition) reduced their drinking. It is suggested that integrating CBM with online cognitive and motivational interventions could improve results. Copyright © 2014 Elsevier Ltd. All rights reserved.

A method for the quantification of biased signalling at constitutively active receptors.

Science.gov (United States)

Hall, David A; Giraldo, Jesús

2018-06-01

Biased agonism, the ability of an agonist to differentially activate one of several signal transduction pathways when acting at a given receptor, is an increasingly recognized phenomenon at many receptors. The Black and Leff operational model lacks a way to describe constitutive receptor activity and hence inverse agonism. Thus, it is impossible to analyse the biased signalling of inverse agonists using this model. In this theoretical work, we develop and illustrate methods for the analysis of biased inverse agonism. Methods were derived for quantifying biased signalling in systems that demonstrate constitutive activity using the modified operational model proposed by Slack and Hall. The methods were illustrated using Monte Carlo simulations. The Monte Carlo simulations demonstrated that, with an appropriate experimental design, the model parameters are 'identifiable'. The method is consistent with methods based on the measurement of intrinsic relative activity (RA i ) (ΔΔlogR or ΔΔlog(τ/K a )) proposed by Ehlert and Kenakin and their co-workers but has some advantages. In particular, it allows the quantification of ligand bias independently of 'system bias' removing the requirement to normalize to a standard ligand. In systems with constitutive activity, the Slack and Hall model provides methods for quantifying the absolute bias of agonists and inverse agonists. This provides an alternative to methods based on RA i and is complementary to the ΔΔlog(τ/K a ) method of Kenakin et al. in systems where use of that method is inappropriate due to the presence of constitutive activity. © 2018 The British Pharmacological Society.

Long-branch attraction bias and inconsistency in Bayesian phylogenetics.

Directory of Open Access Journals (Sweden)

Bryan Kolaczkowski

Full Text Available Bayesian inference (BI of phylogenetic relationships uses the same probabilistic models of evolution as its precursor maximum likelihood (ML, so BI has generally been assumed to share ML's desirable statistical properties, such as largely unbiased inference of topology given an accurate model and increasingly reliable inferences as the amount of data increases. Here we show that BI, unlike ML, is biased in favor of topologies that group long branches together, even when the true model and prior distributions of evolutionary parameters over a group of phylogenies are known. Using experimental simulation studies and numerical and mathematical analyses, we show that this bias becomes more severe as more data are analyzed, causing BI to infer an incorrect tree as the maximum a posteriori phylogeny with asymptotically high support as sequence length approaches infinity. BI's long branch attraction bias is relatively weak when the true model is simple but becomes pronounced when sequence sites evolve heterogeneously, even when this complexity is incorporated in the model. This bias--which is apparent under both controlled simulation conditions and in analyses of empirical sequence data--also makes BI less efficient and less robust to the use of an incorrect evolutionary model than ML. Surprisingly, BI's bias is caused by one of the method's stated advantages--that it incorporates uncertainty about branch lengths by integrating over a distribution of possible values instead of estimating them from the data, as ML does. Our findings suggest that trees inferred using BI should be interpreted with caution and that ML may be a more reliable framework for modern phylogenetic analysis.

Analysis of Reverse-Bias Leakage Current Mechanisms in Metal/GaN Schottky Diodes

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P. Pipinys

2010-01-01

Full Text Available Temperature-dependent reverse-bias current-voltage characteristics obtained by other researchers for Schottky diodes fabricated on GaN are reinterpreted in terms of phonon-assisted tunneling (PhAT model. Temperature dependence of reverse-bias leakage current is shown could be caused by the temperature dependence of electron tunneling rate from traps in the metal-semiconductor interface to the conduction band of semiconductor. A good fit of experimental data with the theory is received in a wide temperature range (from 80 K to 500 K using for calculation the effective mass of 0.222 me. and for the phonon energy the value of 70 meV. The temperature and bias voltages dependences of an apparent barrier height (activation energy are also explicable in the framework of the PhAT model.

DC-dynamic biasing for >50× switching time improvement in severely underdamped fringing-field electrostatic MEMS actuators

International Nuclear Information System (INIS)

Small, J; Liu, X; Fruehling, A; Garg, A; Peroulis, D

2012-01-01

This paper presents the design and experimental validation of dc-dynamic biasing for > 50× switching time improvement in severely underdamped fringing-field electrostatic MEMS actuators. The electrostatic fringing-field actuator is used to demonstrate the concept due to its robust device design and inherently low damping conditions. In order to accurately quantify the gap height versus voltage characteristics, a heuristic model is developed. The difference between the heuristic model and numerical simulation is less than 5.6% for typical MEMS geometries. MEMS fixed–fixed beams are fabricated and measured for experimental validation. Good agreement is observed between the calculated and measured results. For a given voltage, the measured and calculated displacements are typically within 10%. Lastly, the derived model is used to design a dc-dynamic bias waveform to improve the switching time of the underdamped MEMS actuators. With dynamic biasing, the measured up-to-down and down-to-up switching time of the actuator is ∼35 μs. On the other hand, coventional step biasing results in a switching time of ∼2 ms for both up-to-down and down-to-up states. (paper)

Self-biased cobalt ferrite nanocomposites for microwave applications

Energy Technology Data Exchange (ETDEWEB)

Hannour, Abdelkrim, E-mail: abdelkrim.hannour@hotmail.com [LT2C Laboratory, Jean-Monnet University, 25 rue Dr. Rémy Annino, F-42000, Saint-Etienne (France); Vincent, Didier; Kahlouche, Faouzi; Tchangoulian, Ardaches [LT2C Laboratory, Jean-Monnet University, 25 rue Dr. Rémy Annino, F-42000, Saint-Etienne (France); Neveu, Sophie; Dupuis, Vincent [UPMC Univ Paris 06, UMR 7195, PECSA, F-75005, Paris (France)

2014-03-15

Oriented CoFe{sub 2}O{sub 4} nanoparticles, dispersed in polymethyl methacrylate (PMMA) matrix, were fabricated by magnetophoretic deposition of functionalized nanocolloidal cobalt ferrite particles into porous alumina membrane. Their magnetic behavior exhibits an out-of-plane easy axis with a large remanent magnetization and coercitivity. This orientation allows high effective internal magnetic anisotropy that contributes to the permanent bias along the wire axis. The microwave studies reveal a ferromagnetic resonance at 46.5 and 49.5 GHz, depending on the filling ratio of the membrane. Ansoft High Frequency Structure Simulator (Ansoft HFSS) simulations are in good agreement with experimental results. Such nanocomposite is presented as one of the promising candidates for microwave devices (circulators, isolators, noise suppressors etc.). - Highlights: • Oriented magnetic CoFe{sub 2}O{sub 4} nanoparticles were fabricated by magnetophoretic deposition of functionalized cobalt ferrite particles into porous alumina membrane. • The nanocomposite obtained presents an out-of-plane easy axis with a large remanent magnetization and coercitivity. • The high effective internal magnetic anisotropy contributes to the permanent bias along the wire axis. • The frequency ferromagnetic resonance ranges from 46.5 to 49.5 GHz, depending on the filling ratio of the membrane. • We have obtained a good agreement between Ansoft High Frequency Structure Simulator simulations and experimental results.

Experimental concepts for toxicity prevention and tissue restoration after central nervous system irradiation

Directory of Open Access Journals (Sweden)

Astner Sabrina T

2007-06-01

Full Text Available Abstract Several experimental strategies of radiation-induced central nervous system toxicity prevention have recently resulted in encouraging data. The present review summarizes the background for this research and the treatment results. It extends to the perspectives of tissue regeneration strategies, based for example on stem and progenitor cells. Preliminary data suggest a scenario with individually tailored strategies where patients with certain types of comorbidity, resulting in impaired regeneration reserve capacity, might be considered for toxicity prevention, while others might be "salvaged" by delayed interventions that circumvent the problem of normal tissue specificity. Given the complexity of radiation-induced changes, single target interventions might not suffice. Future interventions might vary with patient age, elapsed time from radiotherapy and toxicity type. Potential components include several drugs that interact with neurodegeneration, cell transplantation (into the CNS itself, the blood stream, or both and creation of reparative signals and a permissive microenvironment, e.g., for cell homing. Without manipulation of the stem cell niche either by cell transfection or addition of appropriate chemokines and growth factors and by providing normal perfusion of the affected region, durable success of such cell-based approaches is hard to imagine.

Nonlinear bias compensation of ZiYuan-3 satellite imagery with cubic splines

Science.gov (United States)

Cao, Jinshan; Fu, Jianhong; Yuan, Xiuxiao; Gong, Jianya

2017-11-01

Like many high-resolution satellites such as the ALOS, MOMS-2P, QuickBird, and ZiYuan1-02C satellites, the ZiYuan-3 satellite suffers from different levels of attitude oscillations. As a result of such oscillations, the rational polynomial coefficients (RPCs) obtained using a terrain-independent scenario often have nonlinear biases. In the sensor orientation of ZiYuan-3 imagery based on a rational function model (RFM), these nonlinear biases cannot be effectively compensated by an affine transformation. The sensor orientation accuracy is thereby worse than expected. In order to eliminate the influence of attitude oscillations on the RFM-based sensor orientation, a feasible nonlinear bias compensation approach for ZiYuan-3 imagery with cubic splines is proposed. In this approach, no actual ground control points (GCPs) are required to determine the cubic splines. First, the RPCs are calculated using a three-dimensional virtual control grid generated based on a physical sensor model. Second, one cubic spline is used to model the residual errors of the virtual control points in the row direction and another cubic spline is used to model the residual errors in the column direction. Then, the estimated cubic splines are used to compensate the nonlinear biases in the RPCs. Finally, the affine transformation parameters are used to compensate the residual biases in the RPCs. Three ZiYuan-3 images were tested. The experimental results showed that before the nonlinear bias compensation, the residual errors of the independent check points were nonlinearly biased. Even if the number of GCPs used to determine the affine transformation parameters was increased from 4 to 16, these nonlinear biases could not be effectively compensated. After the nonlinear bias compensation with the estimated cubic splines, the influence of the attitude oscillations could be eliminated. The RFM-based sensor orientation accuracies of the three ZiYuan-3 images reached 0.981 pixels, 0.890 pixels, and 1

Systematic review: primary and secondary prevention of gastrointestinal cancers with antioxidant supplements

DEFF Research Database (Denmark)

Bjelakovic, G.; Nikolova, D.; Simonetti, R.G.

2008-01-01

BACKGROUND: The evidence on whether antioxidant supplements prevent gastrointestinal cancers is contradictory. AIM: To assess the beneficial and harmful effects of antioxidant supplements in preventing gastrointestinal cancers. METHODS: Using the Cochrane Collaboration methodology, we reviewed...... the randomized trials comparing antioxidant supplements with placebo or no intervention on the occurrence of gastrointestinal cancers. We searched electronic databases and reference lists until October, 2007. Our outcome measures were gastrointestinal cancers, overall mortality and adverse events. Outcomes were....... The antioxidant supplements were without a significant effect on the occurrence of gastrointestinal cancers (RR 0.94, 95% CI 0.83-1.06, I(2) = 54.0%). The heterogeneity seemed to be explained by bias risk (low-bias risk trials RR 1.04, 95% CI 0.96-1.13 compared to high-bias risk trials RR 0.59, 95% CI 0...

Low-bias flat band-stop filter based on velocity modulated gaussian graphene superlattice

Science.gov (United States)

Sattari-Esfahlan, S. M.; Shojaei, S.

2018-05-01

Transport properties of biased planar Gaussian graphene superlattice (PGGSL) with Fermi velocity barrier is investigated by transfer matrix method (TMM). It is observed that enlargement of bias voltage over miniband width breaks the miniband to WSLs leads to suppressing resonant tunneling. Transmission spectrum shows flat wide stop-band property controllable by external bias voltage with stop-band width of near 200 meV. The simulations demonstrate that strong velocity barriers prevent tunneling of Dirac electrons leading to controllable enhancement of stop-band width. By increasing ratio of Fermi velocity in barriers to wells υc stop-band width increase. As wide transmission stop-band width (BWT) of filter is tunable from 40 meV to 340 meV is obtained by enhancing ratio of υc from 0.2 to 1.5, respectively. Proposed structure suggests easy tunable wide band-stop electronic filter with a modulated flat stop-band characteristic by height of electrostatic barrier and structural parameters. Robust sensitivity of band width to velocity barrier intensity in certain bias voltages and flat band feature of proposed filter may be opens novel venue in GSL based flat band low noise filters and velocity modulation devices.

A "Scientific Diversity" Intervention to Reduce Gender Bias in a Sample of Life Scientists.

Science.gov (United States)

Moss-Racusin, Corinne A; van der Toorn, Jojanneke; Dovidio, John F; Brescoll, Victoria L; Graham, Mark J; Handelsman, Jo

2016-01-01

Mounting experimental evidence suggests that subtle gender biases favoring men contribute to the underrepresentation of women in science, technology, engineering, and mathematics (STEM), including many subfields of the life sciences. However, there are relatively few evaluations of diversity interventions designed to reduce gender biases within the STEM community. Because gender biases distort the meritocratic evaluation and advancement of students, interventions targeting instructors' biases are particularly needed. We evaluated one such intervention, a workshop called "Scientific Diversity" that was consistent with an established framework guiding the development of diversity interventions designed to reduce biases and was administered to a sample of life science instructors (N = 126) at several sessions of the National Academies Summer Institute for Undergraduate Education held nationwide. Evidence emerged indicating the efficacy of the "Scientific Diversity" workshop, such that participants were more aware of gender bias, expressed less gender bias, and were more willing to engage in actions to reduce gender bias 2 weeks after participating in the intervention compared with 2 weeks before the intervention. Implications for diversity interventions aimed at reducing gender bias and broadening the participation of women in the life sciences are discussed. © 2016 C. A. Moss-Racusin et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Is there room for 'development' in developmental models of information processing biases to threat in children and adolescents?

Science.gov (United States)

Field, Andy P; Lester, Kathryn J

2010-12-01

Clinical and experimental theories assume that processing biases in attention and interpretation are a causal mechanism through which anxiety develops. Despite growing evidence that these processing biases are present in children and, therefore, develop long before adulthood, these theories ignore the potential role of child development. This review attempts to place information processing biases within a theoretical developmental framework. We consider whether child development has no impact on information processing biases to threat (integral bias model), or whether child development influences information processing biases and if so whether it does so by moderating the expression of an existing bias (moderation model) or by affecting the acquisition of a bias (acquisition model). We examine the extent to which these models fit with existing theory and research evidence and outline some methodological issues that need to be considered when drawing conclusions about the potential role of child development in the information processing of threat stimuli. Finally, we speculate about the developmental processes that might be important to consider in future research.

Ligand-promoted protein folding by biased kinetic partitioning.

Science.gov (United States)

Hingorani, Karan S; Metcalf, Matthew C; Deming, Derrick T; Garman, Scott C; Powers, Evan T; Gierasch, Lila M

2017-04-01

Protein folding in cells occurs in the presence of high concentrations of endogenous binding partners, and exogenous binding partners have been exploited as pharmacological chaperones. A combined mathematical modeling and experimental approach shows that a ligand improves the folding of a destabilized protein by biasing the kinetic partitioning between folding and alternative fates (aggregation or degradation). Computationally predicted inhibition of test protein aggregation and degradation as a function of ligand concentration are validated by experiments in two disparate cellular systems.

Cognitive Bias in Systems Verification

Science.gov (United States)

Larson, Steve

2012-01-01

Working definition of cognitive bias: Patterns by which information is sought and interpreted that can lead to systematic errors in decisions. Cognitive bias is used in diverse fields: Economics, Politics, Intelligence, Marketing, to name a few. Attempts to ground cognitive science in physical characteristics of the cognitive apparatus exceed our knowledge. Studies based on correlations; strict cause and effect is difficult to pinpoint. Effects cited in the paper and discussed here have been replicated many times over, and appear sound. Many biases have been described, but it is still unclear whether they are all distinct. There may only be a handful of fundamental biases, which manifest in various ways. Bias can effect system verification in many ways . Overconfidence -> Questionable decisions to deploy. Availability -> Inability to conceive critical tests. Representativeness -> Overinterpretation of results. Positive Test Strategies -> Confirmation bias. Debiasing at individual level very difficult. The potential effect of bias on the verification process can be managed, but not eliminated. Worth considering at key points in the process.

Biases in categorization

NARCIS (Netherlands)

Das-Smaal, E.A.

1990-01-01

On what grounds can we conclude that an act of categorization is biased? In this chapter, it is contended that in the absence of objective norms of what categories actually are, biases in categorization can only be specified in relation to theoretical understandings of categorization. Therefore, the

An experimental examination of catastrophizing-related interpretation bias for ambiguous facial expressions of pain using an incidental learning task

Directory of Open Access Journals (Sweden)

Ali eKHATIBI

2014-09-01

Full Text Available Individuals with pain-related concerns are likely to interpret ambiguous pain-related information in a threatening manner. It is unknown whether this interpretation bias also occurs for ambiguous pain-related facial expressions. This study examined whether individuals who habitually attach a catastrophic meaning to pain are characterized by negative interpretation bias for ambiguous pain-related facial expressions. Sixty-four female undergraduates completed an incidental learning task during which pictures of faces were presented, each followed by a visual target at one of two locations. Participants indicated target location by pressing one of two response keys. During the learning phase, happy and painful facial expressions predicted target location. During two test phases, morphed facial expressions of pain and happiness were added, equally often followed by a target at either location. Faster responses following morphs to targets at the location predicted by painful expressions compared to targets at the location predicted by happy expressions were taken to reflect pain-related interpretation bias. During one test phase, faces were preceded by either a safe or threatening context cue. High, but not low, pain-catastrophizers responded faster following morphs to targets at the location predicted by painful expressions than to targets at the other location (when participants were aware of the contingency between expression type and target location. When context cues were presented, there was no indication of interpretation bias. Participants were also asked to directly classify the facial expressions that were presented during the incidental learning task. Participants classified morphs more often as happy than as painful, independent of their level of pain catastrophizing. This observation is discussed in terms of differences between indirect and direct measures of interpretation bias.

Is in-group bias culture-dependent? A meta-analysis across 18 societies.

Science.gov (United States)

Fischer, Ronald; Derham, Crysta

2016-01-01

We report a meta-analysis on the relationship between in-group bias and culture. Our focus is on whether broad macro-contextual variables influence the extent to which individuals favour their in-group. Data from 21,266 participants from 18 societies included in experimental and survey studies were available. Using Hofstede's (1980) and Schwartz (2006) culture-level predictors in a 3-level mixed-effects meta-analysis, we found strong support for the uncertainty-reduction hypothesis. An interaction between Autonomy and real vs artificial groups suggested that in low autonomy contexts, individuals show greater in-group bias for real groups. Implications for social identity theory and intergroup conflict are outlined.

Cognitive bias measurement and social anxiety disorder: Correlating self-report data and attentional bias

Directory of Open Access Journals (Sweden)

Alexander Miloff

2015-09-01

Full Text Available Social anxiety disorder (SAD and attentional bias are theoretically connected in cognitive behavioral therapeutic models. In fact, there is an emerging field focusing on modifying attentional bias as a stand-alone treatment. However, it is unclear to what degree these attentional biases are present before commencing treatment. The purpose of this study was to measure pre-treatment attentional bias in 153 participants diagnosed with SAD using a home-based Internet version of the dot-probe paradigm. Results showed no significant correlation for attentional bias (towards or away from negative words or faces and the self-rated version of the Liebowitz Social Anxiety Scale (LSAS-SR. However, two positive correlations were found for the secondary measures Generalized Anxiety Disorder 7 (GAD-7 and Patient Health Questionnaire 9 (PHQ-9. These indicated that those with elevated levels of anxiety and depression had a higher bias towards negative faces in neutral–negative and positive–negative valence combinations, respectively. The unreliability of the dot-probe paradigm and home-based Internet delivery are discussed to explain the lack of correlations between LSAS-SR and attentional bias. Changes to the dot-probe task are suggested that could improve reliability.

Facial expression movement enhances the measurement of temporal dynamics of attentional bias in the dot-probe task.

Science.gov (United States)

Caudek, Corrado; Ceccarini, Francesco; Sica, Claudio

2017-08-01

The facial dot-probe task is one of the most common experimental paradigms used to assess attentional bias toward emotional information. In recent years, however, the psychometric properties of this paradigm have been questioned. In the present study, attentional bias to emotional face stimuli was measured with dynamic and static images of realistic human faces in 97 college students (63 women) who underwent either a positive or a negative mood-induction prior to the experiment. We controlled the bottom-up salience of the stimuli in order to dissociate the top-down orienting of attention from the effects of the bottom-up physical properties of the stimuli. A Bayesian analysis of our results indicates that 1) the traditional global attentional bias index shows a low reliability, 2) reliability increases dramatically when biased attention is analyzed by extracting a series of bias estimations from trial-to-trial (Zvielli, Bernstein, & Koster, 2015), 3) dynamic expression of emotions strengthens biased attention to emotional information, and 4) mood-congruency facilitates the measurement of biased attention to emotional stimuli. These results highlight the importance of using ecologically valid stimuli in attentional bias research, together with the importance of estimating biased attention at the trial level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Randomly biased investments and the evolution of public goods on interdependent networks

Science.gov (United States)

Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

2017-08-01

Deciding how to allocate resources between interdependent systems is significant to optimize efficiency. We study the effects of heterogeneous contribution, induced by such interdependency, on the evolution of cooperation, through implementing the public goods games on two-layer networks. The corresponding players on different layers try to share a fixed amount of resources as the initial investment properly. The symmetry breaking of investments between players located on different layers is able to either prevent investments from, or extract them out of the deadlock. Results show that a moderate investment heterogeneity is best favorable for the evolution of cooperation, and random allocation of investment bias suppresses the cooperators at a wide range of the investment bias and the enhancement effect. Further studies on time evolution with different initial strategy configurations show that the non-interdependent cooperators along the interface of interdependent cooperators also are an indispensable factor in facilitating cooperative behavior. Our main results are qualitatively unchanged even diversifying investment bias that is subject to uniform distribution. Our study may shed light on the understanding of the origin of cooperative behavior on interdependent networks.

Effectiveness of two web-based cognitive bias modification interventions targeting approach and attentional bias in gambling problems: study protocol for a pilot randomised controlled trial.

Science.gov (United States)

Boffo, Marilisa; Willemen, Ronny; Pronk, Thomas; Wiers, Reinout W; Dom, Geert

2017-10-03

Disordered gamblers have phenotypical and pathological similarities to those with substance use disorders (SUD), including exaggerated automatic cognitive processing of motivationally salient gambling cues in the environment (i.e., attentional and approach bias). Cognitive bias modification (CBM) is a family of computerised interventions that have proved effective in successfully re-training these automatic cognitive biases in SUD. CBM interventions can, in principle, be administered online, thus showing potential of being a low-cost, low-threshold addition to conventional treatments. This paper presents the design of a pilot randomised controlled trial exploring the effectiveness of two web-based CBM interventions targeting attentional and approach bias towards gambling cues in a sample of Dutch and Belgian problematic and pathological gamblers. Participants (N = 182) are community-recruited adults experiencing gambling problems, who have gambled at least twice in the past 6 months and are motivated to change their gambling behaviour. After a baseline assessment session, participants are randomly assigned to one of four experimental conditions (attentional or approach bias training, or the placebo version of the two trainings) and complete six sessions of training. At baseline and before each training session, participants receive automated personalised feedback on their gambling motives and reasons to quit or reduce gambling. The post-intervention, 1-month, and 3-month follow-up assessments will examine changes in gambling behaviour, with frequency and expenditure as primary outcomes, and depressive symptoms and gambling-related attentional and approach biases as secondary outcomes. Secondary analyses will explore possible moderators (interference control capacity and trait impulsivity) and mediators (change in cognitive bias) of training effects on the primary outcomes. This study is the first to explore the effectiveness of an online CBM intervention for

Threat bias, not negativity bias, underpins differences in political ideology.

Science.gov (United States)

Lilienfeld, Scott O; Latzman, Robert D

2014-06-01

Although disparities in political ideology are rooted partly in dispositional differences, Hibbing et al.'s analysis paints with an overly broad brush. Research on the personality correlates of liberal-conservative differences points not to global differences in negativity bias, but to differences in threat bias, probably emanating from differences in fearfulness. This distinction bears implications for etiological research and persuasion efforts.

New Trends in Magnetic Exchange Bias

Science.gov (United States)

Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois

2005-05-01

of the constituant layers. The spirit of this topical issue is, for the first time, to gather and survey recent and original developments, both experimental and theoretical, which bring new insights into the physics of exchange bias. It has been planned in relation with an international workshop exclusively devoted to exchange bias, namely IWEBMN’04 (International Workshop on Exchange Bias in Magnetic Nanostructures) that took place in Anglet, in the south west of France, from 16th to 18th September 2004. The conference gathered worldwide researchers in the area, both experimentalists and theoreticians. Several research paths are particularly active in the field of magnetic exchange coupling. The conference, as well as this topical issue, which was also open to contributions from scientists not participating in the conference, has been organized according to the following principles: 1. Epitaxial systems: Since the essential behavior of exchange bias critically depends on the atomic-level chemical and spin structure at the interface between the ferromagnetic and antiferromagnetic components, epitaxial AF/F systems in which the quality of the interface and the crystalline coherence are optimized and well known are ideal candidates for a better understanding of the underlying physics of exchange bias. The dependence of exchange bias on the spin configurations at the interfaces can be accomplished by selecting different crystallographic orientations. The role of interface roughness can also be understood from thin-film systems by changing the growth parameters, and correlations between the interface structure and exchange bias can be made, as reported in this issue. 2. Out-of-plane magnetized systems: While much important work has been devoted to the study of structures with in-plane magnetization, little has been done on the study of exchange bias and exchange coupling in samples with out-of-plane magnetization. Some systems can exhibit either in-plane or out

Good practices for quantitative bias analysis.

Science.gov (United States)

Lash, Timothy L; Fox, Matthew P; MacLehose, Richard F; Maldonado, George; McCandless, Lawrence C; Greenland, Sander

2014-12-01

Quantitative bias analysis serves several objectives in epidemiological research. First, it provides a quantitative estimate of the direction, magnitude and uncertainty arising from systematic errors. Second, the acts of identifying sources of systematic error, writing down models to quantify them, assigning values to the bias parameters and interpreting the results combat the human tendency towards overconfidence in research results, syntheses and critiques and the inferences that rest upon them. Finally, by suggesting aspects that dominate uncertainty in a particular research result or topic area, bias analysis can guide efficient allocation of sparse research resources. The fundamental methods of bias analyses have been known for decades, and there have been calls for more widespread use for nearly as long. There was a time when some believed that bias analyses were rarely undertaken because the methods were not widely known and because automated computing tools were not readily available to implement the methods. These shortcomings have been largely resolved. We must, therefore, contemplate other barriers to implementation. One possibility is that practitioners avoid the analyses because they lack confidence in the practice of bias analysis. The purpose of this paper is therefore to describe what we view as good practices for applying quantitative bias analysis to epidemiological data, directed towards those familiar with the methods. We focus on answering questions often posed to those of us who advocate incorporation of bias analysis methods into teaching and research. These include the following. When is bias analysis practical and productive? How does one select the biases that ought to be addressed? How does one select a method to model biases? How does one assign values to the parameters of a bias model? How does one present and interpret a bias analysis?. We hope that our guide to good practices for conducting and presenting bias analyses will encourage

Pain, Precautions and Present-biased Preferences: A Theory of Health Insurance

OpenAIRE

Schumacher, Heiner; Kesternich, Iris

2010-01-01

We develop an insurance market model where consumers (i) exhibit present-biased preferences, and (ii) suffer from physical pain in case of (health-) damage. They can exert preventive effort to reduce the probability of damage. Sophisticated consumers correctly anticipate their effort and purchase full insurance. Naive consumers overestimate their future effort, purchase no insurance and end up with less effort than sophisticated ones. We allow consumers to differ in their wealth and risk pref...

Judgement bias in goats (Capra hircus: investigating the effects of human grooming

Directory of Open Access Journals (Sweden)

Luigi Baciadonna

2016-10-01

Full Text Available Animal emotional states can be investigated by evaluating their impact on cognitive processes. In this study, we used a judgement bias paradigm to determine if short-term positive human-animal interaction (grooming induced a positive affective state in goats. We tested two groups of goats and trained them to discriminate between a rewarded and a non-rewarded location over nine training days. During training, the experimental group (n = 9 was gently groomed by brushing their heads and backs for five min over 11 days (nine training days, plus two testing days, total time 55 min. During training, the control group (n = 10 did not experience any direct interaction with the experimenter, but was kept unconstrained next to him for the same period of time. After successful completion of the training, the responses (latency time of the two groups to reach ambiguous locations situated between the two reference locations (i.e., rewarded/non-rewarded were compared over two days of testing. There was not a positive bias effect after the animals had been groomed. In a second experiment, 10 goats were tested to investigate whether grooming induced changes in physiological activation (i.e., heart rate and heart rate variability. Heart rate increased when goats were groomed compared to the baseline condition, when the same goats did not receive any contact with the experimenter. Also, subjects did not move away from the experimenter, suggesting that the grooming was positively accepted. The very good care and the regular positive contacts that goats received from humans at the study site could potentially account for the results obtained. Good husbandry outcomes are influenced by animals’ perception of the events and this is based on current circumstances, past experiences and individual variables. Taking into account animals’ individual characteristics and identifying effective strategies to induce positive emotions could increase the understanding and

Hindsight bias and outcome bias in the social construction of medical negligence: a review.

Science.gov (United States)

Hugh, Thomas B; Dekker, Sidney W A

2009-05-01

Medical negligence has been the subject of much public debate in recent decades. Although the steep increase in the frequency and size of claims against doctors at the end of the last century appears to have plateaued, in Australia at least, medical indemnity costs and consequences are still a matter of concern for doctors, medical defence organisations and governments in most developed countries. Imprecision in the legal definition of negligence opens the possibility that judgments of this issue at several levels may be subject to hindsight and outcome bias. Hindsight bias relates to the probability of an adverse event perceived by a retrospective observer ("I would have known it was going to happen"), while outcome bias is a largely subconscious cognitive distortion produced by the observer's knowledge of the adverse outcome. This review examines the relevant legal, medical, psychological and sociological literature on the operation of these pervasive and universal biases in the retrospective evaluation of adverse events. A finding of medical negligence is essentially an after-the-event social construction and is invariably affected by hindsight bias and knowledge of the adverse outcome. Such biases obviously pose a threat to the fairness of judgments. A number of debiasing strategies have been suggested but are relatively ineffective because of the universality and strength of these biases and the inherent difficulty of concealing from expert witnesses knowledge of the outcome. Education about the effect of the biases is therefore important for lawyers, medical expert witnesses and the judiciary.

Evolution and maintenance of sexual size dimorphism: Aligning phylogenetic and experimental evidence

Directory of Open Access Journals (Sweden)

Matjaz eKuntner

2014-06-01

Full Text Available Integrating the insights derived from both phylogenetic and experimental approaches offers a more complete understanding of evolutionary patterns and processes, yet it is rarely a feature of investigations of the evolutionary significance of trait variation. We combine these approaches to reinterpret the patterns and processes in the evolution of female biased sexual size dimorphism in Nephilidae, a spider lineage characterized by the most extreme sexual size dimorphism among terrestrial animals. We use a molecular phylogeny to reconstruct the size evolution for each sex and reveal a case of sexually dimorphic gigantism: both sexes steadily outgrow their ancestral sizes, but the female and male slopes differ, and hence sexual size dimorphism steadily increases. A review of the experimental evidence reveals a predominant net selection for large size in both sexes, consistent with the phylogenetic pattern for females but not for males. Thus, while sexual size dimorphism in spiders most likely originates and is maintained by fecundity selection on females, it is unclear what selection pressures prevent males from becoming as large as females. This integrated approach highlights the dangers of inferring evolutionary significance from experimental studies that isolate the effects of single selection pressures.

Photovoltaic Bias Generator

Science.gov (United States)

2018-02-01

Department of the Army position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an... Interior view of the photovoltaic bias generator showing wrapped-wire side of circuit board...3 Fig. 4 Interior view of the photovoltaic bias generator showing component side of circuit board

The endowment effect, status quo bias and loss aversion: rational alternative explanation

NARCIS (Netherlands)

Dupont, D.Y.; Lee, Gabriel S.

2002-01-01

The endowment effect, status quo bias, and loss aversion are robust and well documented results from experimental psychology. They introduce a wedge between the prices at which one is willing to sell or buy a good. The objective of this paper is to address this wedge. We show that the presence of

The endowment effect, status quo bias and loss aversion : rational alternative explanation

NARCIS (Netherlands)

Dupont, D.Y.; Lee, G.S.

2002-01-01

The endowment effect, status quo bias, and loss aversion are robust and well documented results from experimental psychology. They introduce a wedge between the prices at which one is willing to sell or buy a good. The objective of this paper is to address this wedge. We show that the presence of

COMT Val(108/158)Met polymorphism effects on emotional brain function and negativity bias.

Science.gov (United States)

Williams, Leanne M; Gatt, Justine M; Grieve, Stuart M; Dobson-Stone, Carol; Paul, Robert H; Gordon, Evian; Schofield, Peter R

2010-11-15

Biases toward processing negative versus positive information vary as a function of level of awareness, and are modulated by monoamines. Excessive biases are associated with individual differences in mood and emotional stability, and emotional disorder. Here, we examined the impact of the catechol-O-methyltransferase (COMT) Val(108/158)Met polymorphism, involved in dopamine and norepinephrine catabolism, on both emotional brain function and self-reported negativity bias. COMT genotyping and self-reported level of negativity bias were completed for 46 healthy participants taking part in the Brain Resource International Database. Functional MRI was undertaken during perception of facial expressions of fear and happiness presented under unmasked (consciously identified) and masked (to prevent conscious detection) conditions. Structural MR images were also acquired. A greater number of COMT Met alleles predicted increased activation in brainstem, amygdala, basal ganglia and medial prefrontal regions for conscious fear, but decreased activation for conscious happiness. This pattern was also apparent for brainstem activation for the masked condition. Effects were most apparent for females. These differences could not be explained by gray matter variations. The Met-related profile of activation, particularly prefrontally, predicted greater negativity bias associated with risk for emotional disorder. The findings suggest that the COMT Met allele modulates neural substrates of negative versus positive emotion processing. This effect may contribute to negativity biases, which confer susceptibility for emotional disorders. Copyright 2010 Elsevier Inc. All rights reserved.

Bias-correction in vector autoregressive models

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard

2014-01-01

We analyze the properties of various methods for bias-correcting parameter estimates in both stationary and non-stationary vector autoregressive models. First, we show that two analytical bias formulas from the existing literature are in fact identical. Next, based on a detailed simulation study......, we show that when the model is stationary this simple bias formula compares very favorably to bootstrap bias-correction, both in terms of bias and mean squared error. In non-stationary models, the analytical bias formula performs noticeably worse than bootstrapping. Both methods yield a notable...... improvement over ordinary least squares. We pay special attention to the risk of pushing an otherwise stationary model into the non-stationary region of the parameter space when correcting for bias. Finally, we consider a recently proposed reduced-bias weighted least squares estimator, and we find...

Bias versus bias: harnessing hindsight to reveal paranormal belief change beyond demand characteristics.

Science.gov (United States)

Kane, Michael J; Core, Tammy J; Hunt, R Reed

2010-04-01

Psychological change is difficult to assess, in part because self-reported beliefs and attitudes may be biased or distorted. The present study probed belief change, in an educational context, by using the hindsight bias to counter another bias that generally plagues assessment of subjective change. Although research has indicated that skepticism courses reduce paranormal beliefs, those findings may reflect demand characteristics (biases toward desired, skeptical responses). Our hindsight-bias procedure circumvented demand by asking students, following semester-long skepticism (and control) courses, to recall their precourse levels of paranormal belief. People typically remember themselves as previously thinking, believing, and acting as they do now, so current skepticism should provoke false recollections of previous skepticism. Given true belief change, therefore, skepticism students should have remembered themselves as having been more skeptical than they were. They did, at least about paranormal topics that were covered most extensively in the course. Our findings thus show hindsight to be useful in evaluating cognitive change beyond demand characteristics.

It is all in their mind: A review on information processing bias in lonely individuals.

Science.gov (United States)

Spithoven, Annette W M; Bijttebier, Patricia; Goossens, Luc

2017-12-01

Loneliness is a distressing emotional state that motivates individuals to renew and maintain social contact. It has been suggested that lonely individuals suffer from a cognitive bias towards social threatening stimuli. However, current models of loneliness remain vague on how this cognitive bias is expressed in lonely individuals. The current review provides an up-to-date overview of studies examining loneliness in relation to various aspects of cognitive functioning. These studies are interpreted in light of the Social Information Processing (SIP) model. A wide range of studies indicate that lonely individuals have a negative cognitive bias in all stages of SIP. More specifically, lonely individuals have an increased attention for social threatening stimuli, hold negative and hostile intent attributions, expect rejection, evaluate themselves and others negatively, endorse less promotion- and more prevention-oriented goals, and have a low self-efficacy. This negative cognitive bias seems specific to the social context. Avenues for future research and implications for clinical practice are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Towards quantum signatures in a swept-bias Josephson junction

Energy Technology Data Exchange (ETDEWEB)

Losert, Harald; Vogel, Karl; Schleich, Wolfgang P. [Institut fuer Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universitaet Ulm, D-89069 Ulm (Germany)

2016-07-01

Josephson junctions are one of the best examples for the observation of macroscopic quantum tunneling. The phase difference in a current-biased Josephson junction behaves like the position of a particle in a tilted washboard potential. The escape of this phase-particle corresponds to the voltage switching of the associated junction. Quantum mechanically, the escape from the washboard potential can be explained as tunneling from the ground state, or an excited state. However, it has been shown, that in the case of periodic driving the experimental data for quantum mechanical key features, e.g. Rabi oscillations or energy level quantization, can be reproduced by a completely classical description. Motivated by this discussion, we investigate a swept-bias Josephson junction in the case of a large critical current. In particular, we contrast the switching current distributions resulting from a quantum mechanical and classical description of the time evolution.

Reference Materials for Calibration of Analytical Biases in Quantification of DNA Methylation.

Science.gov (United States)

Yu, Hannah; Hahn, Yoonsoo; Yang, Inchul

2015-01-01

Most contemporary methods for the quantification of DNA methylation employ bisulfite conversion and PCR amplification. However, many reports have indicated that bisulfite-mediated PCR methodologies can result in inaccurate measurements of DNA methylation owing to amplification biases. To calibrate analytical biases in quantification of gene methylation, especially those that arise during PCR, we utilized reference materials that represent exact bisulfite-converted sequences with 0% and 100% methylation status of specific genes. After determining relative quantities using qPCR, pairs of plasmids were gravimetrically mixed to generate working standards with predefined DNA methylation levels at 10% intervals in terms of mole fractions. The working standards were used as controls to optimize the experimental conditions and also as calibration standards in melting-based and sequencing-based analyses of DNA methylation. Use of the reference materials enabled precise characterization and proper calibration of various biases during PCR and subsequent methylation measurement processes, resulting in accurate measurements.

[Experimental study on preventing postoperative posterior urethra scar in response to Tablet Fu Kang].

Science.gov (United States)

Mo, Jiacong; Wang, Shengyi

2004-07-01

To find an effective measurement to prevent and decrease the posterior urethral scar stricture. Twenty New Zealand rabbits were chosen. All the rabbits were made posterior urethra disruption model, and at the same time, the urethra anastomosis operation was performed. Twenty rabbits were divided into two groups after operation at random. One group was treated by Tablet Fu Kang (experimental group), another group was treated by NS (control group). All the rabbits were killed three weeks later, the urethra anastomotic stoma tissue was chosen and stained with Masson. All the figures of slides were inputted into figure analytic system. There were little collagenous fiber, sparsely and arranged in good order in scar tissue of urethra anastomotic stoma in experimental group. The area of collagenous fibers was 117.11 +/- 10.17 microm2 in three visual fields. There were many collagenous fibers, densely,and arranged in disorder in scar tissue of urethra anastomotic stoma in control group, the relative area was 136.43 +/- 15.85 microm2. There was statistic significance when comparing the area of collagenous fiber in two groups (P urethra.

Experimental study of 103Pd stents for preventing the restenosis of biliary duct

International Nuclear Information System (INIS)

Gao Qinyi; Shu Qiang; Lu Xiangdong; Li Yaming; He Guijin; Pei Zhuguo; Xu Shuhe

2004-01-01

Objective: To explore the feasibility of preventing biliary duct restenosis with the stent treated with 103 Pd and to elucidate the mechanisms of the inhibition of the smooth muscle cell proliferation and the increase of apoptosis. Methods: The experimental dogs were randomly divided into common-stent group and 103 Pd stent group, each of 6 animals. Pathohistology, cell apoptosis, immunohistochemistry for proliferating cell nuclear antigen (PCNA), the expression of gene p53 by in situs hybridization, the test of the peripheral blood and measurement of radiation of tissue around the stent were studied. Results: The utmost intimal thickness of biliary duct in the 103 Pd stent group was found to be obviously less compared to that in common-stent group after 30 d, the percentages of the stenosis of the biliary duct were (54.73 ± 21.64)% and (17.61 ± 14.52)%, respectively, there was a significant difference between two groups (P 103 Pd stent group, and decreased in the common-stent group; the expression of PCNA of biliary smooth muscle cells of 103 Pd group was weaker compared with that in the common-group. Conclusion: 103 Pd stent may inhibit the proliferation of smooth muscle cells and prevent the restenosis of biliary duct. (authors)

Estimating Sampling Biases and Measurement Uncertainties of AIRS-AMSU-A Temperature and Water Vapor Observations Using MERRA Reanalysis

Science.gov (United States)

Hearty, Thomas J.; Savtchenko, Andrey K.; Tian, Baijun; Fetzer, Eric; Yung, Yuk L.; Theobald, Michael; Vollmer, Bruce; Fishbein, Evan; Won, Young-In

2014-01-01

We use MERRA (Modern Era Retrospective-Analysis for Research Applications) temperature and water vapor data to estimate the sampling biases of climatologies derived from the AIRS/AMSU-A (Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A) suite of instruments. We separate the total sampling bias into temporal and instrumental components. The temporal component is caused by the AIRS/AMSU-A orbit and swath that are not able to sample all of time and space. The instrumental component is caused by scenes that prevent successful retrievals. The temporal sampling biases are generally smaller than the instrumental sampling biases except in regions with large diurnal variations, such as the boundary layer, where the temporal sampling biases of temperature can be +/- 2 K and water vapor can be 10% wet. The instrumental sampling biases are the main contributor to the total sampling biases and are mainly caused by clouds. They are up to 2 K cold and greater than 30% dry over mid-latitude storm tracks and tropical deep convective cloudy regions and up to 20% wet over stratus regions. However, other factors such as surface emissivity and temperature can also influence the instrumental sampling bias over deserts where the biases can be up to 1 K cold and 10% wet. Some instrumental sampling biases can vary seasonally and/or diurnally. We also estimate the combined measurement uncertainties of temperature and water vapor from AIRS/AMSU-A and MERRA by comparing similarly sampled climatologies from both data sets. The measurement differences are often larger than the sampling biases and have longitudinal variations.

Specific Depletion of Ly6Chi Inflammatory Monocytes Prevents Immunopathology in Experimental Cerebral Malaria

Science.gov (United States)

Kuepper, Janina M.; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes. PMID:25884830

Enhanced exchange bias fields for CoO/Co bilayers: influence of antiferromagnetic grains and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Chang, Cheng-Hsun-Tony; Chang, Shin-Chen [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Tsay, Jyh-Shen, E-mail: jstsay@phy.ntnu.edu.tw [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Yao, Yeong-Der [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)

2017-05-31

Highlights: • An antiferromagnetic grain model on exchange bias phenomena is proposed. • Grain size and grain density are considered. • For smaller grain size, the dependence of t{sub CoO} on T{sub B} showed a less pronounced variation. • An increased grain density is responsible for the enhancement in the exchange bias fields. - Abstract: The emergence and optimization of devices that can be applied to spintronics have attracted considerable interest, and both experimental and theoretical approaches have been used in studies of exchange bias phenomena. A survey of the literature indicates that great efforts have been devoted to improving exchange bias fields, while only limited attempts have been made to control the temperature dependence of exchange bias. In this study, the influence of antiferromagnetic grains on exchange bias phenomena in CoO/Co bilayers on a semiconductor surface was investigated. Based on an antiferromagnetic grain model, a correlation between grain size, grain density, blocking temperature, and the exchange bias field was established. For crystallites with a smaller median diameter, the dependence of the thickness of the CoO layer on blocking temperature showed a less pronounced variation. This is due to the larger thermal agitation of the atomic spin moments in the grain, which causes a weaker exchange coupling between atomic spin moments. The enhanced density of antiferromagnetic/ferromagnetic pinning sites resulting from an increased grain density is responsible for the enhancement in the exchange bias fields. The results reported herein provide insights into our knowledge related to controlling the temperature dependence of exchange bias and related mechanisms.

Dynamic remodeling of in-group bias during the 2008 presidential election.

Science.gov (United States)

Rand, David G; Pfeiffer, Thomas; Dreber, Anna; Sheketoff, Rachel W; Wernerfelt, Nils C; Benkler, Yochai

2009-04-14

People often favor members of their own group, while discriminating against members of other groups. Such in-group favoritism has been shown to play an important role in human cooperation. However, in the face of changing conflicts and shifting alliances, it is essential for group identities to be flexible. Using the dictator game from behavioral economics, we demonstrate the remodeling of group identities among supporters of Democratic presidential candidates Barack Obama and Hillary Clinton. After Clinton's concession in June 2008, Democrats were more generous toward supporters of their own preferred candidate than to supporters of the other Democratic candidate. The bias observed in June persisted into August, and disappeared only in early September after the Democratic National Convention. We also observe a strong gender effect, with bias both appearing and subsiding among men only. This experimental study illustrates a dynamic change in bias, tracking the realignment of real world conflict lines and public efforts to reconstitute group identity. The change in salient group identity we describe here likely contributed to the victory of Barack Obama in the 2008 presidential election.

Economic incentives for additional critical experimentation applicable to fuel dissolution

International Nuclear Information System (INIS)

Mincey, J.F.; Primm, R.T. III; Waltz, W.R.

1981-01-01

Fuel dissolution operations involving soluble absorbers for criticality control are among the most difficult to establish economical subcritical limits. The paucity of applicable experimental data can significantly hinder a precise determination of a bias in the method chosen for calculation of the required soluble absorber concentration. Resorting to overly conservative bias estimates can result in excessive concentrations of soluble absorbers. Such conservatism can be costly, especially if soluble absorbers are used in a throw-away fashion. An economic scoping study is presented which demonstrates that additional critical experimentation will likely lead to reductions in the soluble absorber (i.e., gadolinium) purchase costs for dissolution operations. The results indicate that anticipated savings maybe more than enough to pay for the experimental costs

Left cheek bias for emotion perception, but not expression, is established in children aged 3-7 years.

Science.gov (United States)

Lindell, Annukka K; Tenenbaum, Harriet R; Aznar, Ana

2017-01-01

As the left hemiface is controlled by the emotion-dominant right hemisphere, emotion is expressed asymmetrically. Portraits showing a model's left cheek consequently appear more emotive. Though the left cheek bias is well established in adults, it has not been investigated in children. To determine whether the left cheek biases for emotion perception and expression are present and/or develop between the ages of 3 and 7 years, 145 children (71 male, 74 female; M age = 65.49 months) completed two experimental tasks: one assessing biases in emotion perception, and the other assessing biases in emotion expression. Regression analysis confirmed that children aged 3-7 years find left cheek portraits happier than right cheek portraits, and age does not predict the magnitude of the bias. In contrast when asked to pose for a photo expressing happiness children did not show a left cheek bias, with logistic regression confirming that age did not predict posing orientations. These findings indicate that though the left cheek bias for emotion perception is established by age 3, a similar bias for emotion expression is not evident by age 7. This implies that tacit knowledge of the left cheek's greater expressivity is not innate but develops in later childhood/adolescence.

Toward a synthesis of cognitive biases: how noisy information processing can bias human decision making.

Science.gov (United States)

Hilbert, Martin

2012-03-01

A single coherent framework is proposed to synthesize long-standing research on 8 seemingly unrelated cognitive decision-making biases. During the past 6 decades, hundreds of empirical studies have resulted in a variety of rules of thumb that specify how humans systematically deviate from what is normatively expected from their decisions. Several complementary generative mechanisms have been proposed to explain those cognitive biases. Here it is suggested that (at least) 8 of these empirically detected decision-making biases can be produced by simply assuming noisy deviations in the memory-based information processes that convert objective evidence (observations) into subjective estimates (decisions). An integrative framework is presented to show how similar noise-based mechanisms can lead to conservatism, the Bayesian likelihood bias, illusory correlations, biased self-other placement, subadditivity, exaggerated expectation, the confidence bias, and the hard-easy effect. Analytical tools from information theory are used to explore the nature and limitations that characterize such information processes for binary and multiary decision-making exercises. The ensuing synthesis offers formal mathematical definitions of the biases and their underlying generative mechanism, which permits a consolidated analysis of how they are related. This synthesis contributes to the larger goal of creating a coherent picture that explains the relations among the myriad of seemingly unrelated biases and their potential psychological generative mechanisms. Limitations and research questions are discussed.

A “scientific diversity” intervention to reduce gender bias in a sample of life scientists

NARCIS (Netherlands)

Moss-Racusin, C. A.; van der Toorn, J.; Dovidio, J. F.; Brescoli, V. L.; Graham, M. J.; Handelsman, J.

2016-01-01

Mounting experimental evidence suggests that subtle gender biases favoring men contribute to the underrepresentation of women in science, technology, engineering, and mathematics (STEM), including many subfields of the life sciences. However, there are relatively few evaluations of diversity

[Negative bias on self-referent processing in depression: focused on mood congruent effects].

Science.gov (United States)

Tagami, Kyoko

2002-12-01

The purpose of this study was to investigate negative bias on self-referent processing in depression, focused on the mood congruent effects in a natural depressed state and an experimentally induced transient depressed mood state. In Experiment 1, autobiographical memories and self-relevant ratings of personality trait words were examined in a natural depressed state or non-depressed state, which were measured by Beck Depression Inventory. Results revealed the mood congruent effects on both tasks. In Experiment 2, the same tasks as Experiment 1 were conducted in a transient depressed mood state or non-depressed mood state, which were induced through listening music. Unlike Experiment 1, there were no effects in both tasks, and a positive bias was observed in both mood states. It was suggested that transient mood state did not bias self-referent processing in depression, and Beck's schema hypothesis was supported.

Molecular doping for control of gate bias stress in organic thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Hein, Moritz P., E-mail: hein@iapp.de; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Zakhidov, Alexander A. [Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany); Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany)

2014-01-06

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface.

Molecular doping for control of gate bias stress in organic thin film transistors

International Nuclear Information System (INIS)

Hein, Moritz P.; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K.; Zakhidov, Alexander A.; Leo, Karl

2014-01-01

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface

Melatonin prevents experimental preterm labor and increases offspring survival.

Science.gov (United States)

Domínguez Rubio, Ana P; Sordelli, Micaela S; Salazar, Ana I; Aisemberg, Julieta; Bariani, María V; Cella, Maximiliano; Rosenstein, Ruth E; Franchi, Ana M

2014-03-01

Preterm delivery is the leading cause of neonatal mortality and contributes to delayed physical and cognitive development in children. At present, there is no efficient therapy to prevent preterm labor. A large body of evidence suggests that intra-amniotic infections may be a significant and potentially preventable cause of preterm birth. This work assessed the effect of melatonin in a murine model of inflammation-associated preterm delivery which mimics central features of preterm infection in humans. For this purpose, preterm labor was induced in BALB/c mice by intraperitoneal injections of bacterial lipopolysaccharide (LPS) at 10.00 hr (10 μg LPS) and 13.00 hr (20 μg LPS) on day 15 of pregnancy. On day 14 of pregnancy, a pellet of melatonin (25 mg) had been subcutaneously implanted into a group of animals. In the absence of melatonin, a 100% incidence of preterm birth was observed in LPS-treated animals, and the fetuses showed widespread damage. By comparison, treatment with melatonin prevented preterm birth in 50% of the cases, and all pups from melatonin-treated females were born alive and their body weight did not differ from control animals. Melatonin significantly prevented the LPS-induced rises in uterine prostaglandin (PG) E2 , PGF2α, and cyclooxygenase-2 protein levels. In addition, melatonin prevented the LPS-induced increase in uterine nitric oxide (NO) production, inducible NO synthase protein, and tumor necrosis factor-alpha (TNFα) levels. Collectively, our results suggest that melatonin could be a new therapeutic tool to prevent preterm labor and to increase offspring survival. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bias in clinical intervention research

DEFF Research Database (Denmark)

Gluud, Lise Lotte

2006-01-01

Research on bias in clinical trials may help identify some of the reasons why investigators sometimes reach the wrong conclusions about intervention effects. Several quality components for the assessment of bias control have been suggested, but although they seem intrinsically valid, empirical...... evidence is needed to evaluate their effects on the extent and direction of bias. This narrative review summarizes the findings of methodological studies on the influence of bias in clinical trials. A number of methodological studies suggest that lack of adequate randomization in published trial reports...

Stimulus-Driven Attention, Threat Bias, and Sad Bias in Youth with a History of an Anxiety Disorder or Depression.

Science.gov (United States)

Sylvester, Chad M; Hudziak, James J; Gaffrey, Michael S; Barch, Deanna M; Luby, Joan L

2016-02-01

Attention biases towards threatening and sad stimuli are associated with pediatric anxiety and depression, respectively. The basic cognitive mechanisms associated with attention biases in youth, however, remain unclear. Here, we tested the hypothesis that threat bias (selective attention for threatening versus neutral stimuli) but not sad bias relies on stimulus-driven attention. We collected measures of stimulus-driven attention, threat bias, sad bias, and current clinical symptoms in youth with a history of an anxiety disorder and/or depression (ANX/DEP; n = 40) as well as healthy controls (HC; n = 33). Stimulus-driven attention was measured with a non-emotional spatial orienting task, while threat bias and sad bias were measured at a short time interval (150 ms) with a spatial orienting task using emotional faces and at a longer time interval (500 ms) using a dot-probe task. In ANX/DEP but not HC, early attention bias towards threat was negatively correlated with later attention bias to threat, suggesting that early threat vigilance was associated with later threat avoidance. Across all subjects, stimulus-driven orienting was not correlated with early threat bias but was negatively correlated with later threat bias, indicating that rapid stimulus-driven orienting is linked to later threat avoidance. No parallel relationships were detected for sad bias. Current symptoms of depression but not anxiety were related to decreased stimulus-driven attention. Together, these results are consistent with the hypothesis that threat bias but not sad bias relies on stimulus-driven attention. These results inform the design of attention bias modification programs that aim to reverse threat biases and reduce symptoms associated with pediatric anxiety and depression.

Stimulus-driven attention, threat bias, and sad bias in youth with a history of an anxiety disorder or depression

Science.gov (United States)

Sylvester, Chad M.; Hudziak, James J.; Gaffrey, Michael S.; Barch, Deanna M.; Luby, Joan L.

2015-01-01

Attention biases towards threatening and sad stimuli are associated with pediatric anxiety and depression, respectively. The basic cognitive mechanisms associated with attention biases in youth, however, remain unclear. Here, we tested the hypothesis that threat bias (selective attention for threatening versus neutral stimuli) but not sad bias relies on stimulus-driven attention. We collected measures of stimulus-driven attention, threat bias, sad bias, and current clinical symptoms in youth with a history of an anxiety disorder and/or depression (ANX/DEP; n=40) as well as healthy controls (HC; n=33). Stimulus-driven attention was measured with a non-emotional spatial orienting task, while threat bias and sad bias were measured at a short time interval (150 ms) with a spatial orienting task using emotional faces and at a longer time interval (500 ms) using a dot-probe task. In ANX/DEP but not HC, early attention bias towards threat was negatively correlated with later attention bias to threat, suggesting that early threat vigilance was associated with later threat avoidance. Across all subjects, stimulus-driven orienting was not correlated with early threat bias but was negatively correlated with later threat bias, indicating that rapid stimulus-driven orienting is linked to later threat avoidance. No parallel relationships were detected for sad bias. Current symptoms of depression but not anxiety were related to decreased stimulus-driven attention. Together, these results are consistent with the hypothesis that threat bias but not sad bias relies on stimulus-driven attention. These results inform the design of attention bias modification programs that aim to reverse threat biases and reduce symptoms associated with pediatric anxiety and depression. PMID:25702927

Benefits of being biased!

Indian Academy of Sciences (India)

Administrator

Journal of Genetics, Vol. 83, No. 2, August 2004. Keywords. codon bias; alcohol dehydrogenase; Darwinian ... RESEARCH COMMENTARY. Benefits of being biased! SUTIRTH DEY*. Evolutionary Biology Laboratory, Evolutionary & Organismal Biology Unit,. Jawaharlal Nehru Centre for Advanced Scientific Research,.

Low-bias negative differential conductance controlled by electrode separation

Science.gov (United States)

Yi, Xiao-Hua; Liu, Ran; Bi, Jun-Jie; Jiao, Yang; Wang, Chuan-Kui; Li, Zong-Liang

2016-12-01

The electronic transport properties of a single thiolated arylethynylene molecule with 9,10-dihydroanthracene core, denoted as TADHA, is studied by using non-equilibrium Green’s function formalism combined with ab initio calculations. The numerical results show that the TADHA molecule exhibits excellent negative differential conductance (NDC) behavior at lower bias regime as probed experimentally. The NDC behavior of TADHA molecule originates from the Stark effect of the applied bias voltage, by which the highest occupied molecular orbital (HOMO) and the HOMO-1 are pulled apart and become localized. The NDC behavior of TADHA molecular system is tunable by changing the electrode distance. Shortening the electrode separation can enhance the NDC effect which is attributed to the possible increase of coupling between the two branches of TADHA molecule. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374195 and 11405098) and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2013FM006).

Biases in GNSS-Data Processing

Science.gov (United States)

Schaer, S. C.; Dach, R.; Lutz, S.; Meindl, M.; Beutler, G.

2010-12-01

Within the Global Positioning System (GPS) traditionally different types of pseudo-range measurements (P-code, C/A-code) are available on the first frequency that are tracked by the receivers with different technologies. For that reason, P1-C1 and P1-P2 Differential Code Biases (DCB) need to be considered in a GPS data processing with a mix of different receiver types. Since the Block IIR-M series of GPS satellites also provide C/A-code on the second frequency, P2-C2 DCB need to be added to the list of biases for maintenance. Potential quarter-cycle biases between different phase observables (specifically L2P and L2C) are another issue. When combining GNSS (currently GPS and GLONASS), careful consideration of inter-system biases (ISB) is indispensable, in particular when an adequate combination of individual GLONASS clock correction results from different sources (using, e.g., different software packages) is intended. Facing the GPS and GLONASS modernization programs and the upcoming GNSS, like the European Galileo and the Chinese Compass, an increasing number of types of biases is expected. The Center for Orbit Determination in Europe (CODE) is monitoring these GPS and GLONASS related biases for a long time based on RINEX files of the tracking network of the International GNSS Service (IGS) and in the frame of the data processing as one of the global analysis centers of the IGS. Within the presentation we give an overview on the stability of the biases based on the monitoring. Biases derived from different sources are compared. Finally, we give an outlook on the potential handling of such biases with the big variety of signals and systems expected in the future.

d'plus: A program to calculate accuracy and bias measures from detection and discrimination data.

Science.gov (United States)

Macmillan, N A; Creelman, C D

1997-01-01

The program d'plus calculates accuracy (sensitivity) and response-bias parameters using Signal Detection Theory. Choice Theory, and 'nonparametric' models. is is appropriate for data from one-interval, two- and three-interval forced-choice, same different, ABX, and oddity experimental paradigms.

Evaluation of FOXFET biased ac-coupled silicon strip detector prototypes for CDF SVX upgrade

Energy Technology Data Exchange (ETDEWEB)

Laakso, M. (Fermi National Accelerator Lab., Batavia, IL (United States) Research Inst. for High Energy Physics (SEFT), Helsinki (Finland))

1992-03-01

Silicon microstrip detectors for high-precision charged particle position measurements have been used in nuclear and particle physics for years. The detectors have evolved from simple surface barrier strip detectors with metal strips to highly complicated double-sided AC-coupled junction detectors. The feature of AC-coupling the readout electrodes from the diode strips necessitates the manufacture of a separate biasing structure for the strips, which comprises a common bias line together with a means for preventing the signal from one strip from spreading to its neighbors through the bias line. The obvious solution to this is to bias the strips through individual high value resistors. These resistors can be integrated on the detector wafer by depositing a layer of resistive polycrystalline silicon and patterning it to form the individual resistors. To circumvent the extra processing step required for polysilicon resistor processing and the rather difficult tuning of the process to obtain uniform and high enough resistance values throughout the large detector area, alternative methods for strip biasing have been devised. These include the usage of electron accumulation layer resistance for N{sup +}{minus} strips or the usage of the phenomenon known as the punch-through effect for P{sup +}{minus} strips. In this paper we present measurement results about the operation and radiation resistance of detectors with a punch-through effect based biasing structure known as a Field OXide Field-Effect Transistor (FOXFET), and present a model describing the FOXFET behavior. The studied detectors were prototypes for detectors to be used in the CDF silicon vertex detector upgrade.

Evaluation of FOXFET biased ac-coupled silicon strip detector prototypes for CDF SVX upgrade

International Nuclear Information System (INIS)

Laakso, M.

1992-03-01

Silicon microstrip detectors for high-precision charged particle position measurements have been used in nuclear and particle physics for years. The detectors have evolved from simple surface barrier strip detectors with metal strips to highly complicated double-sided AC-coupled junction detectors. The feature of AC-coupling the readout electrodes from the diode strips necessitates the manufacture of a separate biasing structure for the strips, which comprises a common bias line together with a means for preventing the signal from one strip from spreading to its neighbors through the bias line. The obvious solution to this is to bias the strips through individual high value resistors. These resistors can be integrated on the detector wafer by depositing a layer of resistive polycrystalline silicon and patterning it to form the individual resistors. To circumvent the extra processing step required for polysilicon resistor processing and the rather difficult tuning of the process to obtain uniform and high enough resistance values throughout the large detector area, alternative methods for strip biasing have been devised. These include the usage of electron accumulation layer resistance for N + - strips or the usage of the phenomenon known as the punch-through effect for P + - strips. In this paper we present measurement results about the operation and radiation resistance of detectors with a punch-through effect based biasing structure known as a Field OXide Field-Effect Transistor (FOXFET), and present a model describing the FOXFET behavior. The studied detectors were prototypes for detectors to be used in the CDF silicon vertex detector upgrade

Multicultural experiences reduce intergroup bias through epistemic unfreezing.

Science.gov (United States)

Tadmor, Carmit T; Hong, Ying-Yi; Chao, Melody M; Wiruchnipawan, Fon; Wang, Wei

2012-11-01

In 6 studies, we systematically explored for the 1st time the ameliorative effects of multicultural experience on intergroup bias and investigated the role of epistemic unfreezing as the motivational mechanism underlying these effects. We found that multicultural exposure led to a reduction in stereotype endorsement (Studies 1, 4, and 6), symbolic racism (Study 5), and discriminatory hiring decisions (Study 2). We further demonstrated that experimental exposure to multicultural experience caused a reduction in need for cognitive closure (NFCC; Studies 3 and 6) and that the ameliorative effects of multiculturalism experience on intergroup bias were fully mediated by lower levels of NFCC (Studies 4, 5, and 6). The beneficial effects of multiculturalism were found regardless of the targeted stereotype group (African Americans, Ethiopians, homosexuals, and native Israelis), regardless of whether multicultural experience was measured or manipulated, and regardless of the population sampled (Caucasian Americans or native Israelis), demonstrating the robustness of this phenomenon. Overall, these results demonstrate that multicultural experience plays a critical role in increasing social tolerance through its relationship to motivated cognitive processes.

Bias aware Kalman filters

DEFF Research Database (Denmark)

Drecourt, J.-P.; Madsen, H.; Rosbjerg, Dan

2006-01-01

This paper reviews two different approaches that have been proposed to tackle the problems of model bias with the Kalman filter: the use of a colored noise model and the implementation of a separate bias filter. Both filters are implemented with and without feedback of the bias into the model state....... The colored noise filter formulation is extended to correct both time correlated and uncorrelated model error components. A more stable version of the separate filter without feedback is presented. The filters are implemented in an ensemble framework using Latin hypercube sampling. The techniques...... are illustrated on a simple one-dimensional groundwater problem. The results show that the presented filters outperform the standard Kalman filter and that the implementations with bias feedback work in more general conditions than the implementations without feedback. 2005 Elsevier Ltd. All rights reserved....

Introducing etch kernels for efficient pattern sampling and etch bias prediction

Science.gov (United States)

Weisbuch, François; Lutich, Andrey; Schatz, Jirka

2018-01-01

Successful patterning requires good control of the photolithography and etch processes. While compact litho models, mainly based on rigorous physics, can predict very well the contours printed in photoresist, pure empirical etch models are less accurate and more unstable. Compact etch models are based on geometrical kernels to compute the litho-etch biases that measure the distance between litho and etch contours. The definition of the kernels, as well as the choice of calibration patterns, is critical to get a robust etch model. This work proposes to define a set of independent and anisotropic etch kernels-"internal, external, curvature, Gaussian, z_profile"-designed to represent the finest details of the resist geometry to characterize precisely the etch bias at any point along a resist contour. By evaluating the etch kernels on various structures, it is possible to map their etch signatures in a multidimensional space and analyze them to find an optimal sampling of structures. The etch kernels evaluated on these structures were combined with experimental etch bias derived from scanning electron microscope contours to train artificial neural networks to predict etch bias. The method applied to contact and line/space layers shows an improvement in etch model prediction accuracy over standard etch model. This work emphasizes the importance of the etch kernel definition to characterize and predict complex etch effects.

Social anxiety is characterized by biased learning about performance and the self.

Science.gov (United States)

Koban, Leonie; Schneider, Rebecca; Ashar, Yoni K; Andrews-Hanna, Jessica R; Landy, Lauren; Moscovitch, David A; Wager, Tor D; Arch, Joanna J

2017-12-01

People learn about their self from social information, and recent work suggests that healthy adults show a positive bias for learning self-related information. In contrast, social anxiety disorder (SAD) is characterized by a negative view of the self, yet what causes and maintains this negative self-view is not well understood. Here the authors use a novel experimental paradigm and computational model to test the hypothesis that biased social learning regarding self-evaluation and self-feelings represents a core feature that distinguishes adults with SAD from healthy controls. Twenty-one adults with SAD and 35 healthy controls (HCs) performed a speech in front of 3 judges. They subsequently evaluated themselves and received performance feedback from the judges and then rated how they felt about themselves and the judges. Affective updating (i.e., change in feelings about the self over time, in response to feedback from the judges) was modeled using an adapted Rescorla-Wagner learning model. HCs demonstrated a positivity bias in affective updating, which was absent in SAD. Further, self-performance ratings revealed group differences in learning from positive feedback-a difference that endured at an average of 1 year follow up. These findings demonstrate the presence and long-term endurance of positively biased social learning about the self among healthy adults, a bias that is absent or reversed among socially anxious adults. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Go!: results from a quasi-experimental obesity prevention trial with hospital employees

Directory of Open Access Journals (Sweden)

Lara J. LaCaille

2016-02-01

Full Text Available Abstract Background Worksite obesity prevention interventions using an ecological approach may hold promise for reducing typical weight gain. The purpose of this study was to examine the effectiveness of Go!, an innovative 12-month multi-component worksite obesity prevention intervention. Methods A quasi-experimental non-equivalent control group design was utilized; 407 eligible hospital employees (intervention arm and 93 eligible clinic employees (comparison arm participated. The intervention involved pedometer distribution, labeling of all foods in the worksite cafeteria and vending machines (with calories, step equivalent, and a traffic light based on energy density signaling recommended portion, persuasive messaging throughout the hospital, and the integration of influential employees to reinforce healthy social norms. Changes in weight, BMI, waist circumference, physical activity, and dietary behavior after 6 months and 1 year were primary outcomes. Secondary outcomes included knowledge, perceptions of employer commitment to employee health, availability of information about diet, exercise, and weight loss, perceptions of coworker support and frequency of health discussions with coworkers. A process evaluation was conducted as part of the study. Results Repeated measures ANCOVA indicated that neither group showed significant increases in weight, BMI, or waist circumference over 12 months. The intervention group showed a modest increase in physical activity in the form of walking, but decreases in fruit and vegetable servings and fiber intake. They also reported significant increases in knowledge, information, perceptions of employer commitment, and health discussions with peers. Employees expressed positive attitudes towards all components of the Go! intervention. Conclusions This low-intensity intervention was well-received by employees but had little effect on their weight over the course of 12 months. Such results are consistent with

Go!: results from a quasi-experimental obesity prevention trial with hospital employees.

Science.gov (United States)

LaCaille, Lara J; Schultz, Jennifer Feenstra; Goei, Ryan; LaCaille, Rick A; Dauner, Kim Nichols; de Souza, Rebecca; Nowak, Amy Versnik; Regal, Ronald

2016-02-19

Worksite obesity prevention interventions using an ecological approach may hold promise for reducing typical weight gain. The purpose of this study was to examine the effectiveness of Go!, an innovative 12-month multi-component worksite obesity prevention intervention. A quasi-experimental non-equivalent control group design was utilized; 407 eligible hospital employees (intervention arm) and 93 eligible clinic employees (comparison arm) participated. The intervention involved pedometer distribution, labeling of all foods in the worksite cafeteria and vending machines (with calories, step equivalent, and a traffic light based on energy density signaling recommended portion), persuasive messaging throughout the hospital, and the integration of influential employees to reinforce healthy social norms. Changes in weight, BMI, waist circumference, physical activity, and dietary behavior after 6 months and 1 year were primary outcomes. Secondary outcomes included knowledge, perceptions of employer commitment to employee health, availability of information about diet, exercise, and weight loss, perceptions of coworker support and frequency of health discussions with coworkers. A process evaluation was conducted as part of the study. Repeated measures ANCOVA indicated that neither group showed significant increases in weight, BMI, or waist circumference over 12 months. The intervention group showed a modest increase in physical activity in the form of walking, but decreases in fruit and vegetable servings and fiber intake. They also reported significant increases in knowledge, information, perceptions of employer commitment, and health discussions with peers. Employees expressed positive attitudes towards all components of the Go! This low-intensity intervention was well-received by employees but had little effect on their weight over the course of 12 months. Such results are consistent with other worksite obesity prevention studies using ecological approaches

Risk of bias reporting in the recent animal focalcerebral ischaemia literature

DEFF Research Database (Denmark)

Bahor, Zsanett; Liao, Jing; Macleod, Malcolm

2017-01-01

Background: Findings from in vivo research may be less reliable where studies do not re-port measures to reduce risks of bias. The experimental stroke community has been at the forefront of implementing changes to improve reporting, but it is not known whether these efforts are associated...... analytic approaches to automatically ascertain re-porting of measures to reduce risk of bias from full-text articles describing animal experi-ments inducing middle cerebral artery occlusion (MCAO) or modelling lacunar stroke.Results: Compared with previous assessments, there were improvements...... was 67% (randomization), 91% (blinding) and 96% (sample size calculation).Discussion: There remains substantial opportunity for improvement in the reporting of an-imal research modelling stroke, particularly in the lacunar stroke literature. Further, auto-mated tools perform sufficiently well to identify...

The impact of the biasing radial electric field on the SOL in a divertor tokamak

International Nuclear Information System (INIS)

Rozhansky, V.; Tendler, M.

1993-01-01

Strong radial electric field can be induced within the SOL in a divertor tokamak by applying a voltage to divertor plates with respect to the first wall. This biasing scheme results in the strong radial electric field which is much larger than the natural electric field, usually of the order T e /e. Experiments employing this biasing scheme were carried out on the tokamak TdeV. Many interesting effects such as - modifications of the density profile and radial transport of impurities as a function of the polarity and the magnitude of the biasing voltage, the generation of the flux surface average toroidal rotation proportional to the applied voltage, redistribution of the plasma outflow onto divertor plates and so on - were demonstrated to result from the biasing. Furthermore, in contrast to studies carried out employing a different biasing scheme which primarily results in a poloidal electric field, the strong radial electric field impacts more significantly within SOL than the poloidal electric field. Here, we aim to show that the main effects observed experimentally follow from the analysis, provided continuity and momentum balances are employed invoking anomalous viscosity and inertia. (author) 4 refs

High- and Low-Level Dissonance-Based Eating Disorder Prevention Programs with Young Women with Body Image Concerns: An Experimental Trial

Science.gov (United States)

McMillan, Whitney; Stice, Eric; Rohde, Paul

2011-01-01

Objective: As cognitive dissonance is theorized to contribute to the effects of dissonance-based eating disorder prevention programs, we evaluated a high-dissonance version of this program against a low-dissonance version and a wait-list control condition to provide an experimental test of the mechanism of intervention effects. Method: Female…

Measuring Agricultural Bias

DEFF Research Database (Denmark)

Jensen, Henning Tarp; Robinson, Sherman; Tarp, Finn

The measurement issue is the key issue in the literature on trade policy-induced agri-cultural price incentive bias. This paper introduces a general equilibrium effective rate of protection (GE-ERP) measure, which extends and generalizes earlier partial equilibrium nominal protection measures...... shares and intersectoral linkages - are crucial for determining the sign and magnitude of trade policy bias. The GE-ERP measure is therefore uniquely suited to capture the full impact of trade policies on agricultural price incentives. A Monte Carlo procedure confirms that the results are robust....... For the 15 sample countries, the results indicate that the agricultural price incentive bias, which was generally perceived to exist during the 1980s, was largely eliminated during the 1990s. The results also demonstrate that general equilibrium effects and country-specific characteristics - including trade...

Exploring Selective Exposure and Confirmation Bias as Processes Underlying Employee Work Happiness: An Intervention Study.

Science.gov (United States)

Williams, Paige; Kern, Margaret L; Waters, Lea

2016-01-01

Employee psychological capital (PsyCap), perceptions of organizational virtue (OV), and work happiness have been shown to be associated within and over time. This study examines selective exposure and confirmation bias as potential processes underlying PsyCap, OV, and work happiness associations. As part of a quasi-experimental study design, school staff (N = 69) completed surveys at three time points. After the first assessment, some staff (n = 51) completed a positive psychology training intervention. Results of descriptive statistics, correlation, and regression analyses on the intervention group provide some support for selective exposure and confirmation bias as explanatory mechanisms. In focusing on the processes through which employee attitudes may influence work happiness this study advances theoretical understanding, specifically of selective exposure and confirmation bias in a field study context.

The price of information: Increased inspection costs reduce the confirmation bias in visual search.

Science.gov (United States)

Rajsic, Jason; Wilson, Daryl E; Pratt, Jay

2018-04-01

In visual search, there is a confirmation bias such that attention is biased towards stimuli that match a target template, which has been attributed to covert costs of updating the templates that guide search [Rajsic, Wilson, & Pratt, 2015. Confirmation bias in visual search. Journal of Experimental Psychology: Human Perception and Performance. Advance online publication. doi:10.1037/xhp0000090]. In order to provide direct evidence for this speculation, the present study increased the cost of inspections in search by using gaze- and mouse-contingent searches, which restrict the manner in which information in search displays can be accrued, and incur additional motor costs (in the case of mouse-contingent searches). In a fourth experiment, we rhythmically mask elements in the search display to induce temporal inspection costs. Our results indicated that confirmation bias is indeed attenuated when inspection costs are increased. We conclude that confirmation bias results from the low-cost strategy of matching information to a single, concrete visual template, and that more sophisticated guidance strategies will be used when sufficiently beneficial. This demonstrates that search guidance itself comes at a cost, and that the form of guidance adopted in a given search depends on a comparison between guidance costs and the expected benefits of their implementation.

Administrative bias in South Africa

Directory of Open Access Journals (Sweden)

E S Nwauche

2005-01-01

Full Text Available This article reviews the interpretation of section 6(2(aii of the Promotion of Administrative Justice Act which makes an administrator “biased or reasonably suspected of bias” a ground of judicial review. In this regard, the paper reviews the determination of administrative bias in South Africa especially highlighting the concept of institutional bias. The paper notes that inspite of the formulation of the bias ground of review the test for administrative bias is the reasonable apprehension test laid down in the case of President of South Africa v South African Rugby Football Union(2 which on close examination is not the same thing. Accordingly the paper urges an alternative interpretation that is based on the reasonable suspicion test enunciated in BTR Industries South Africa (Pty Ltd v Metal and Allied Workers Union and R v Roberts. Within this context, the paper constructs a model for interpreting the bias ground of review that combines the reasonable suspicion test as interpreted in BTR Industries and R v Roberts, the possibility of the waiver of administrative bias, the curative mechanism of administrative appeal as well as some level of judicial review exemplified by the jurisprudence of article 6(1 of the European Convention of Human Rights, especially in the light of the contemplation of the South African Magistrate Court as a jurisdictional route of judicial review.

Attention, interpretation, and memory biases in subclinical depression: a proof-of-principle test of the combined cognitive biases hypothesis.

Science.gov (United States)

Everaert, Jonas; Duyck, Wouter; Koster, Ernst H W

2014-04-01

Emotional biases in attention, interpretation, and memory are viewed as important cognitive processes underlying symptoms of depression. To date, there is a limited understanding of the interplay among these processing biases. This study tested the dependence of memory on depression-related biases in attention and interpretation. Subclinically depressed and nondepressed participants completed a computerized version of the scrambled sentences test (measuring interpretation bias) while their eye movements were recorded (measuring attention bias). This task was followed by an incidental free recall test of previously constructed interpretations (measuring memory bias). Path analysis revealed a good fit for the model in which selective orienting of attention was associated with interpretation bias, which in turn was associated with a congruent bias in memory. Also, a good fit was observed for a path model in which biases in the maintenance of attention and interpretation were associated with memory bias. Both path models attained a superior fit compared with path models without the theorized functional relations among processing biases. These findings enhance understanding of how mechanisms of attention and interpretation regulate what is remembered. As such, they offer support for the combined cognitive biases hypothesis or the notion that emotionally biased cognitive processes are not isolated mechanisms but instead influence each other. Implications for theoretical models and emotion regulation across the spectrum of depressive symptoms are discussed.

Leveraging position bias to improve peer recommendation.

Directory of Open Access Journals (Sweden)

Kristina Lerman

Full Text Available With the advent of social media and peer production, the amount of new online content has grown dramatically. To identify interesting items in the vast stream of new content, providers must rely on peer recommendation to aggregate opinions of their many users. Due to human cognitive biases, the presentation order strongly affects how people allocate attention to the available content. Moreover, we can manipulate attention through the presentation order of items to change the way peer recommendation works. We experimentally evaluate this effect using Amazon Mechanical Turk. We find that different policies for ordering content can steer user attention so as to improve the outcomes of peer recommendation.

Production bias: A proposed modification of the driving force for void swelling under cascade damage conditions

International Nuclear Information System (INIS)

Woo, C.H.; Garner, F.A.

1991-11-01

A new concept of point-defect production as the main driving force for void swelling under cascade damage conditions is proposed. This concept takes into account the recombination and formation of immobile clusters and loops of vacancies and interstitials in the cascade region. The life times of the clusters and loops due to desolution are strong functions of the temperature, as well as their vacancy and interstitial nature. The resulting biased production of free point defects from the internal sources is shown to be a strong driving force for void swelling. The characteristics of void swelling due to production bias are described and compared with experimental results. We conclude that the production bias concept provides a good description of void swelling under cascade damage conditions

Production bias: A proposed modification of the driving force for void swelling under cascade damage conditions

International Nuclear Information System (INIS)

Woo, C.H.; Singh, B.N.; Garner, F.A.

1992-01-01

A new concept of point defect production as the main driving force for void swelling under cascade damage conditions is proposed. This concept takes into account the recombination and formation of immobile clusters and loops of vacancies and interstitials in the cascade region. The lifetimes of the clusters and loops due to desolution are strong functions of the temperature, as well as their vacancy and interstitial nature. The resulting biased production of free point defects from the internal sources is shown to be a strong driving force for void swelling. The characteristics of void swelling due to production bias are described and compared with experimental results. We conclude that the production bias concept provides a good description of void swelling under cascade damage conditions. (orig.)

Preferences, country bias, and international trade

NARCIS (Netherlands)

S. Roy (Santanu); J.M.A. Viaene (Jean-Marie)

1998-01-01

textabstractAnalyzes international trade where consumer preferences exhibit country bias. Why country biases arise; How trade can occur in the presence of country bias; Implication for the pattern of trade and specialization.

Expressing gambling-related cognitive biases in motor behaviour: rolling dice to win prizes.

Science.gov (United States)

Lim, Matthew S M; Bowden-Jones, Henrietta; Rogers, Robert D

2014-09-01

Cognitive perspectives on gambling propose that biased thinking plays a significant role in sustaining gambling participation and, in vulnerable individuals, gambling problems. One prominent set of cognitive biases include illusions of control involving beliefs that it is possible to influence random gaming events. Sociologists have reported that (some) gamblers believe that it is possible to throw dice in different ways to achieve gaming outcomes (e.g., 'dice-setting' in craps). However, experimental demonstrations of these phenomena are lacking. Here, we asked regular gamblers to roll a computer-simulated, but fair, 6 sided die for monetary prizes. Gamblers allowed the die to roll for longer when attempting to win higher value bets, and when attempting to hit high winning numbers. This behaviour was exaggerated in gamblers motivated to keep gambling following the experience of almost-winning in gambling games. These results suggest that gambling cognitive biases find expression in the motor behaviour of rolling dice for monetary prizes, possibly reflecting embodied substrates.

Biases in casino betting

Directory of Open Access Journals (Sweden)

James Sundali

2006-07-01

Full Text Available We examine two departures of individual perceptions of randomness from probability theory: the hot hand and the gambler's fallacy, and their respective opposites. This paper's first contribution is to use data from the field (individuals playing roulette in a casino to demonstrate the existence and impact of these biases that have been previously documented in the lab. Decisions in the field are consistent with biased beliefs, although we observe significant individual heterogeneity in the population. A second contribution is to separately identify these biases within a given individual, then to examine their within-person correlation. We find a positive and significant correlation across individuals between hot hand and gambler's fallacy biases, suggesting a common (root cause of the two related errors. We speculate as to the source of this correlation (locus of control, and suggest future research which could test this speculation.

An inclusive taxonomy of behavioral biases

Directory of Open Access Journals (Sweden)

David Peón

2017-07-01

Full Text Available This paper overviews the theoretical and empirical research on behavioral biases and their influence in the literature. To provide a systematic exposition, we present a unified framework that takes the reader through an original taxonomy, based on the reviews of relevant authors in the field. In particular, we establish three broad categories that may be distinguished: heuristics and biases; choices, values and frames; and social factors. We then describe the main biases within each category, and revise the main theoretical and empirical developments, linking each bias with other biases and anomalies that are related to them, according to the literature.

Undesirable Choice Biases with Small Differences in the Spatial Structure of Chance Stimulus Sequences.

Directory of Open Access Journals (Sweden)

David Herrera

Full Text Available In two-alternative discrimination tasks, experimenters usually randomize the location of the rewarded stimulus so that systematic behavior with respect to irrelevant stimuli can only produce chance performance on the learning curves. One way to achieve this is to use random numbers derived from a discrete binomial distribution to create a 'full random training schedule' (FRS. When using FRS, however, sporadic but long laterally-biased training sequences occur by chance and such 'input biases' are thought to promote the generation of laterally-biased choices (i.e., 'output biases'. As an alternative, a 'Gellerman-like training schedule' (GLS can be used. It removes most input biases by prohibiting the reward from appearing on the same location for more than three consecutive trials. The sequence of past rewards obtained from choosing a particular discriminative stimulus influences the probability of choosing that same stimulus on subsequent trials. Assuming that the long-term average ratio of choices matches the long-term average ratio of reinforcers, we hypothesized that a reduced amount of input biases in GLS compared to FRS should lead to a reduced production of output biases. We compared the choice patterns produced by a 'Rational Decision Maker' (RDM in response to computer-generated FRS and GLS training sequences. To create a virtual RDM, we implemented an algorithm that generated choices based on past rewards. Our simulations revealed that, although the GLS presented fewer input biases than the FRS, the virtual RDM produced more output biases with GLS than with FRS under a variety of test conditions. Our results reveal that the statistical and temporal properties of training sequences interacted with the RDM to influence the production of output biases. Thus, discrete changes in the training paradigms did not translate linearly into modifications in the pattern of choices generated by a RDM. Virtual RDMs could be further employed to guide

Undesirable Choice Biases with Small Differences in the Spatial Structure of Chance Stimulus Sequences.

Science.gov (United States)

Herrera, David; Treviño, Mario

2015-01-01

In two-alternative discrimination tasks, experimenters usually randomize the location of the rewarded stimulus so that systematic behavior with respect to irrelevant stimuli can only produce chance performance on the learning curves. One way to achieve this is to use random numbers derived from a discrete binomial distribution to create a 'full random training schedule' (FRS). When using FRS, however, sporadic but long laterally-biased training sequences occur by chance and such 'input biases' are thought to promote the generation of laterally-biased choices (i.e., 'output biases'). As an alternative, a 'Gellerman-like training schedule' (GLS) can be used. It removes most input biases by prohibiting the reward from appearing on the same location for more than three consecutive trials. The sequence of past rewards obtained from choosing a particular discriminative stimulus influences the probability of choosing that same stimulus on subsequent trials. Assuming that the long-term average ratio of choices matches the long-term average ratio of reinforcers, we hypothesized that a reduced amount of input biases in GLS compared to FRS should lead to a reduced production of output biases. We compared the choice patterns produced by a 'Rational Decision Maker' (RDM) in response to computer-generated FRS and GLS training sequences. To create a virtual RDM, we implemented an algorithm that generated choices based on past rewards. Our simulations revealed that, although the GLS presented fewer input biases than the FRS, the virtual RDM produced more output biases with GLS than with FRS under a variety of test conditions. Our results reveal that the statistical and temporal properties of training sequences interacted with the RDM to influence the production of output biases. Thus, discrete changes in the training paradigms did not translate linearly into modifications in the pattern of choices generated by a RDM. Virtual RDMs could be further employed to guide the selection of

[Cognitive experimental approach to anxiety disorders].

Science.gov (United States)

Azaïs, F

1995-01-01

Cognitive psychology is proposing a functional model to explain the mental organisation leading to emotional disorders. Among these disorders, anxiety spectrum represents a domain in which this model seems to be interesting for an efficient and comprehensive approach of the pathology. Number of behavioral or cognitive psychotherapeutic methods are relating to these cognitive references, but the theorical concepts of cognitive "shemata" or cognitive "processes" evoked to describe mental functioning in anxiety need an experimental approach for a better rational understanding. Cognitive function as perception, attention or memory can be explored in this domaine in an efficient way, allowing a more precise study of each stage of information processing. The cognitive model proposed in the psychopathology of anxiety suggests that anxious subjects are characterized by biases in processing of emotionally valenced information. This hypothesis suggests functional interference in information processing in these subjects, leading to an anxious response to the most of different stimuli. Experimental approach permit to explore this hypothesis, using many tasks for testing different cognitive dysfunction evoked in the anxious cognitive organisation. Impairments revealed in anxiety disorders seem to result from specific biases in threat-related information processing, involving several stages of cognitive processes. Semantic interference, attentional bias, implicit memory bias and priming effect are the most often disorders observed in anxious pathology, like simple phobia, generalised anxiety, panic disorder or post-traumatic stress disorder. These results suggest a top-down organisation of information processing in anxious subjects, who tend to detect, perceive and label many situations as threatening experience. The processes of reasoning and elaboration are consequently impaired in their adaptative function to threat, leading to the anxious response observed in clinical

Is trait resilience characterized by specific patterns of attentional bias to emotional stimuli and attentional control?

Science.gov (United States)

Schäfer, Judith; Wittchen, Hans-Ulrich; Höfler, Michael; Heinrich, Anke; Zimmermann, Peter; Siegel, Stefan; Schönfeld, Sabine

2015-09-01

Attentional processes have been suggested to play a crucial role in resilience defined as positive adaptation facing adversity. However, research is lacking on associations between attentional biases to positive and threat-related stimuli, attentional control and trait resilience. Data stem from the follow-up assessment of a longitudinal study investigating mental health and related factors among German soldiers. Trait resilience was assessed with the Connor-Davidson Resilience Scale and attentional control with the Attentional Control Scale. A subset of n = 198 soldiers also completed a dot probe task with happy, neutral and threatening faces. Attentional control was positively related to trait resilience. Results revealed no associations between both attentional biases and trait resilience. However, there was a negative association between attentional bias to threat and trait resilience when attentional control was low and a positive association between attentional bias to threat and trait resilience when attentional control was high. No such associations were found for attentional bias to positive stimuli. Generalizability to other populations may be limited since we exclusively focused on male soldiers. Also, the cross-sectional design does not allow for causal conclusions. Findings suggest that attentional processing may promote trait resilience. Future research on preventive interventions should consider these findings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Probing Biased Signaling in Chemokine Receptors

DEFF Research Database (Denmark)

Amarandi, Roxana Maria; Hjortø, Gertrud Malene; Rosenkilde, Mette Marie

2016-01-01

The chemokine system mediates leukocyte migration during homeostatic and inflammatory processes. Traditionally, it is described as redundant and promiscuous, with a single chemokine ligand binding to different receptors and a single receptor having several ligands. Signaling of chemokine receptors...... of others has been termed signaling bias and can accordingly be grouped into ligand bias, receptor bias, and tissue bias. Bias has so far been broadly overlooked in the process of drug development. The low number of currently approved drugs targeting the chemokine system, as well as the broad range...... of failed clinical trials, reflects the need for a better understanding of the chemokine system. Thus, understanding the character, direction, and consequence of biased signaling in the chemokine system may aid the development of new therapeutics. This review describes experiments to assess G protein...

A kinetic model of trp-cage folding from multiple biased molecular dynamics simulations.

Directory of Open Access Journals (Sweden)

Fabrizio Marinelli

2009-08-01

Full Text Available Trp-cage is a designed 20-residue polypeptide that, in spite of its size, shares several features with larger globular proteins.Although the system has been intensively investigated experimentally and theoretically, its folding mechanism is not yet fully understood. Indeed, some experiments suggest a two-state behavior, while others point to the presence of intermediates. In this work we show that the results of a bias-exchange metadynamics simulation can be used for constructing a detailed thermodynamic and kinetic model of the system. The model, although constructed from a biased simulation, has a quality similar to those extracted from the analysis of long unbiased molecular dynamics trajectories. This is demonstrated by a careful benchmark of the approach on a smaller system, the solvated Ace-Ala3-Nme peptide. For theTrp-cage folding, the model predicts that the relaxation time of 3100 ns observed experimentally is due to the presence of a compact molten globule-like conformation. This state has an occupancy of only 3% at 300 K, but acts as a kinetic trap.Instead, non-compact structures relax to the folded state on the sub-microsecond timescale. The model also predicts the presence of a state at Calpha-RMSD of 4.4 A from the NMR structure in which the Trp strongly interacts with Pro12. This state can explain the abnormal temperature dependence of the Pro12-delta3 and Gly11-alpha3 chemical shifts. The structures of the two most stable misfolded intermediates are in agreement with NMR experiments on the unfolded protein. Our work shows that, using biased molecular dynamics trajectories, it is possible to construct a model describing in detail the Trp-cage folding kinetics and thermodynamics in agreement with experimental data.

Angular dependence of the exchange bias for the bistable state

Energy Technology Data Exchange (ETDEWEB)

Bai, Yuhao [College of Physics and Electronic Information, Shanxi Normal University, Linfen 041004 (China); Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Xu, Xiaohong, E-mail: xuxh@dns.sxnu.edu.cn [Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University, Linfen 041004 (China)

2017-06-15

The angular dependence of the exchange bias (ADEB) has been investigated in detail when the exchange-coupled ferromagnetic (FM)/antiferromagnetic (AFM) bilayer is in the bistable state. Complete and incomplete jump phenomena were found at the intrinsic easy and hard axes, when they pass through two special positions making the angular deviation of 58.2826° and 121.7174° from the easy axis of the uniaxial anisotropy, respectively. The combination of these different types of the jump phenomena at the intrinsic easy and hard axes yields five distinct types of the ADEB. The physical condition for each type of ADEB is established. Additionally, the extreme value problem of the exchange bias field and coercivity are also discussed, which is an important technological issue in the design of the magnetoresistive and spintronic devices. These results enable us to make a comprehensive understanding of the experimental ADEB curves.

Three regularities of recognition memory: the role of bias.

Science.gov (United States)

Hilford, Andrew; Maloney, Laurence T; Glanzer, Murray; Kim, Kisok

2015-12-01

A basic assumption of Signal Detection Theory is that decisions are made on the basis of likelihood ratios. In a preceding paper, Glanzer, Hilford, and Maloney (Psychonomic Bulletin & Review, 16, 431-455, 2009) showed that the likelihood ratio assumption implies that three regularities will occur in recognition memory: (1) the Mirror Effect, (2) the Variance Effect, (3) the normalized Receiver Operating Characteristic (z-ROC) Length Effect. The paper offered formal proofs and computational demonstrations that decisions based on likelihood ratios produce the three regularities. A survey of data based on group ROCs from 36 studies validated the likelihood ratio assumption by showing that its three implied regularities are ubiquitous. The study noted, however, that bias, another basic factor in Signal Detection Theory, can obscure the Mirror Effect. In this paper we examine how bias affects the regularities at the theoretical level. The theoretical analysis shows: (1) how bias obscures the Mirror Effect, not the other two regularities, and (2) four ways to counter that obscuring. We then report the results of five experiments that support the theoretical analysis. The analyses and the experimental results also demonstrate: (1) that the three regularities govern individual, as well as group, performance, (2) alternative explanations of the regularities are ruled out, and (3) that Signal Detection Theory, correctly applied, gives a simple and unified explanation of recognition memory data.

Bias-voltage dependence of perpendicular spin-transfer torque in asymmetric MgO-based magnetic tunnel junctions

KAUST Repository

Oh, Se Chung

2009-10-25

Spin-transfer torque (STT) allows the electrical control of magnetic states in nanostructures. The STT in magnetic tunnel junctions (MTJs) is of particular importance owing to its potential for device applications. It has been demonstrated that the MTJ has a sizable perpendicular STT (, field-like torque), which substantially affects STT-driven magnetization dynamics. In contrast to symmetric MTJs where the bias dependence of is quadratic, it is theoretically predicted that the symmetry breaking of the system causes an extra linear bias dependence. Here, we report experimental results that are consistent with the predicted linear bias dependence in asymmetric MTJs. The linear contribution is quite significant and its sign changes from positive to negative as the asymmetry is modified. This result opens a way to design the bias dependence of the field-like term, which is useful for device applications by allowing, in particular, the suppression of the abnormal switching-back phenomena. © 2009 Macmillan Publishers Limited. All rights reserved.

Bias-voltage dependence of perpendicular spin-transfer torque in asymmetric MgO-based magnetic tunnel junctions

KAUST Repository

Oh, Se Chung; Park, Seung Young; Manchon, Aurelien; Chshiev, Mairbek; Han, Jae Ho; Lee, Hyun Woo; Lee, Jang Eun; Nam, Kyung Tae; Jo, Younghun; Kong, Yo Chan; Dieny, Bernard; Lee, Kyung Jin

2009-01-01

Spin-transfer torque (STT) allows the electrical control of magnetic states in nanostructures. The STT in magnetic tunnel junctions (MTJs) is of particular importance owing to its potential for device applications. It has been demonstrated that the MTJ has a sizable perpendicular STT (, field-like torque), which substantially affects STT-driven magnetization dynamics. In contrast to symmetric MTJs where the bias dependence of is quadratic, it is theoretically predicted that the symmetry breaking of the system causes an extra linear bias dependence. Here, we report experimental results that are consistent with the predicted linear bias dependence in asymmetric MTJs. The linear contribution is quite significant and its sign changes from positive to negative as the asymmetry is modified. This result opens a way to design the bias dependence of the field-like term, which is useful for device applications by allowing, in particular, the suppression of the abnormal switching-back phenomena. © 2009 Macmillan Publishers Limited. All rights reserved.

Role of dynamical screening in excitation kinetics of biased quantum wells: Nonlinear absorption and ultrabroadband terahertz emission

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Monozon, B. S.; Jepsen, Peter Uhd

2006-01-01

In this work we describe the ultrafast excitation kinetics of biased quantum well, arising from the optically induced dynamical screening of a bias electric field. The initial bia electric field inside the quantum well is screened by the optically excited polarized electron-hole pairs. This leads...... wells are in good agreement with our experimental observations [Turchinovich et al., Phys. Rev. B 68, 241307(R) (2003)], as well as in perfect compliance with qualitative considerations. ©2006 American Institute of Physics...

Ensemble stacking mitigates biases in inference of synaptic connectivity

Directory of Open Access Journals (Sweden)

Brendan Chambers

2018-03-01

Full Text Available A promising alternative to directly measuring the anatomical connections in a neuronal population is inferring the connections from the activity. We employ simulated spiking neuronal networks to compare and contrast commonly used inference methods that identify likely excitatory synaptic connections using statistical regularities in spike timing. We find that simple adjustments to standard algorithms improve inference accuracy: A signing procedure improves the power of unsigned mutual-information-based approaches and a correction that accounts for differences in mean and variance of background timing relationships, such as those expected to be induced by heterogeneous firing rates, increases the sensitivity of frequency-based methods. We also find that different inference methods reveal distinct subsets of the synaptic network and each method exhibits different biases in the accurate detection of reciprocity and local clustering. To correct for errors and biases specific to single inference algorithms, we combine methods into an ensemble. Ensemble predictions, generated as a linear combination of multiple inference algorithms, are more sensitive than the best individual measures alone, and are more faithful to ground-truth statistics of connectivity, mitigating biases specific to single inference methods. These weightings generalize across simulated datasets, emphasizing the potential for the broad utility of ensemble-based approaches. Mapping the routing of spikes through local circuitry is crucial for understanding neocortical computation. Under appropriate experimental conditions, these maps can be used to infer likely patterns of synaptic recruitment, linking activity to underlying anatomical connections. Such inferences help to reveal the synaptic implementation of population dynamics and computation. We compare a number of standard functional measures to infer underlying connectivity. We find that regularization impacts measures

Motivational Reasons for Biased Decisions: The Sunk-Cost Effect’s Instrumental Rationality

Science.gov (United States)

Domeier, Markus; Sachse, Pierre; Schäfer, Bernd

2018-01-01

The present study describes the mechanism of need regulation, which accompanies the so-called “biased” decisions. We hypothesized an unconscious urge for psychological need satisfaction as the trigger for cognitive biases. In an experimental study (N = 106), participants had the opportunity to win money in a functionality test. In the test, they could either use the solution they had developed (sunk cost) or an alternative solution that offered a higher probability of winning. The selection of the sunk-cost option (SCO) was the most chosen option, supporting the hypothesis of this study. The reason behind the majority of participants choosing the SCO seemed to be the satisfaction of psychological needs, despite a reduced chance of winning money. An intervention, which aimed at triggering self-reflection, had no impact on the decision. The findings of this study contribute to the discussion on the reasons for cognitive biases and their formation in the human mind. Moreover, it discusses the application of the label “irrational” for biased decisions and proposes reasons for instrumental rationality, which exist at an unconscious, need-regulative level. PMID:29881366

Bias-field equalizer for bubble memories

Science.gov (United States)

Keefe, G. E.

1977-01-01

Magnetoresistive Perm-alloy sensor monitors bias field required to maintain bubble memory. Sensor provides error signal that, in turn, corrects magnitude of bias field. Error signal from sensor can be used to control magnitude of bias field in either auxiliary set of bias-field coils around permanent magnet field, or current in small coils used to remagnetize permanent magnet by infrequent, short, high-current pulse or short sequence of pulses.

Theoretical investigation of phase-controlled bias effect in capacitively coupled plasma discharges

International Nuclear Information System (INIS)

Kwon, Deuk-Chul; Yoon, Jung-Sik

2011-01-01

We theoretically investigated the effect of phase difference between powered electrodes in capacitively coupled plasma (CCP) discharges. Previous experimental result has shown that the plasma potential could be controlled by using a phase-shift controller in CCP discharges. In this work, based on the previously developed radio frequency sheath models, we developed a circuit model to self-consistently determine the bias voltage from the plasma parameters. Results show that the present theoretical model explains the experimental results quite well and there is an optimum value of the phase difference for which the V dc /V pp ratio becomes a minimum.

Zero-bias peaks in the tunneling conductance of spin-orbit-coupled superconducting wires with and without Majorana end-states.

Science.gov (United States)

Liu, Jie; Potter, Andrew C; Law, K T; Lee, Patrick A

2012-12-28

One of the simplest proposed experimental probes of a Majorana bound state is a quantized (2e(2)/h) value of zero-bias tunneling conductance. When temperature is somewhat larger than the intrinsic width of the Majorana peak, conductance is no longer quantized, but a zero-bias peak can remain. Such a nonquantized zero-bias peak has been recently reported for semiconducting nanowires with proximity induced superconductivity. In this Letter we analyze the relation of the zero-bias peak to the presence of Majorana end states, by simulating the tunneling conductance for multiband wires with realistic amounts of disorder. We show that this system generically exhibits a (nonquantized) zero-bias peak even when the wire is topologically trivial and does not possess Majorana end states. We make comparisons to recent experiments, and discuss the necessary requirements for confirming the existence of a Majorana state.

The role of weight teasing and weight bias internalization in psychological functioning: a prospective study among school-aged children.

Science.gov (United States)

Zuba, Anna; Warschburger, Petra

2017-10-01

Weight-related teasing is a widespread phenomenon in childhood, and might foster the internalization of weight bias. The goal of this study was to examine the role of weight teasing and weight bias internalization as mediators between weight status and negative psychological sequelae, such as restrained eating and emotional and conduct problems in childhood. Participants included 546 female (52%) and 501 (48%) male children aged 7-11 and their parents, who completed surveys assessing weight teasing, weight bias internalization, restrained eating behaviors, and emotional and conduct problems at two points of measurement, approximately 2 years apart. To examine the hypothesized mediation, a prospective design using structural equation modeling was applied. As expected, the experience of weight teasing and the internalization of weight bias were mediators in the relationship between weight status and psychosocial problems. This pattern was observed independently of gender or weight status. Our findings suggest that the experience of weight teasing and internalization of weight bias is more important than weight status in explaining psychological functioning among children and indicate a need for appropriate prevention and intervention approaches.

Introduction to Unconscious Bias

Science.gov (United States)

Schmelz, Joan T.

2010-05-01

We all have biases, and we are (for the most part) unaware of them. In general, men and women BOTH unconsciously devalue the contributions of women. This can have a detrimental effect on grant proposals, job applications, and performance reviews. Sociology is way ahead of astronomy in these studies. When evaluating identical application packages, male and female University psychology professors preferred 2:1 to hire "Brian” over "Karen” as an assistant professor. When evaluating a more experienced record (at the point of promotion to tenure), reservations were expressed four times more often when the name was female. This unconscious bias has a repeated negative effect on Karen's career. This talk will introduce the concept of unconscious bias and also give recommendations on how to address it using an example for a faculty search committee. The process of eliminating unconscious bias begins with awareness, then moves to policy and practice, and ends with accountability.

Preventive interventions among children exposed to trauma of armed conflict: a literature review.

Science.gov (United States)

Peltonen, Kirsi; Punamäki, Raija-Leena

2010-01-01

Increasing research is available on the preconditions for child mental health and optimal development in traumatic conditions, whereas less is known how to translate the findings into effective interventions to help traumatized children. This literature review analyses the effectiveness of psychosocial preventive interventions and treatments and their theoretical bases among children traumatized in the context of armed conflicts (war, military violence, terrorism and refugee). The first aim is to evaluate the effectiveness of preventive interventions in preventing emotional distress and impairment and promoting optimal emotional-cognitive and social development. The second task is to analyze the nature of the underlying mechanisms for the success of preventive interventions, and the theoretical premises of the choice of intervention techniques, procedures and tools. We found 16 relevant published studies, but an examination of them revealed that only four of them had experimental designs strong enough that they could be included in the meta-analysis. While the subjective reports of the researchers suggested that systematic preventive interventions were effective in decreasing PTSD and depressive symptoms among children traumatized due to armed conflict, the more objective results of the meta-analysis and the weaknesses in designs uncovered during the meta-analysis undermine such a conclusion. Additionally, a majority of the reported preventive interventions focused only on children's biased cognitive processes and negative emotions, while only a few aimed at influencing multiple domains of child development and improving developmental functioning on emotional, social and psychophysiological levels. It is concluded that substantial additional work needs to be done in developing effective preventive interventions and treatments for children traumatized by exposure to war and violence. (c) 2009 Wiley-Liss, Inc.

Research bias in judgement bias studies : a systematic review of valuation judgement literature

NARCIS (Netherlands)

Vincent Gruis; Pim Klamer; Cok Bakker

2017-01-01

Valuation judgement bias has been a research topic for several years due to its proclaimed effect on valuation accuracy. However, little is known on the emphasis of literature on judgement bias, with regard to, for instance, research methodologies, research context and robustness of research

Research bias in judgement bias studies : A systematic review of valuation judgement literature

NARCIS (Netherlands)

Klamer, Pim; Bakker, C.; Gruis, Vincent

2017-01-01

Valuation judgement bias has been a research topic for several years due to its proclaimed effect on valuation accuracy. However, little is known on the emphasis of literature on judgement bias, with regard to, for instance, research methodologies, research context and robustness of research

A quasi-experimental study on a community-based stroke prevention programme for clients with minor stroke.

Science.gov (United States)

Sit, Janet W H; Yip, Vera Y B; Ko, Stanley K K; Gun, Amy P C; Lee, Judy S H

2007-02-01

The aim of this study was to determine the effectiveness of a community-based stroke prevention programme in (1) improving knowledge about stroke; (2) improving self-health-monitoring practice; (3) maintaining behavioural changes when adopting a healthy lifestyle for stroke prevention. People with minor stroke (or transient ischaemic attack) tend to under-estimate the long-term impact of this on their health. The challenge for nurses is to prevent subsequent strokes by finding ways to promote and sustain appropriate behaviours. Educational intervention is of paramount importance in equipping those at risk with relevant knowledge and self-care strategies for secondary stroke prevention. This study adopted a quasi-experimental design. One hundred and ninety subjects were recruited, of whom 147 (77 in the intervention group and 70 in the control group) completed the study. Data were obtained at three time points: baseline (T0); one week after (T1) and three months after (T2) the intervention. The intervention programme consisted of eight weekly two-hour sessions, with the aims of improving the participants' awareness of their own health signals and of actively involving them in self-care management of their own health for secondary stroke prevention. Significant positive changes were found among participants of the intervention group in the knowledge on stroke warning signs (P lifestyle modification of dietary habits (reduction in salted food intake, P = 0.004). No significant improvement was found in walking exercise participation in the intervention group, yet a significant decrease was detected among the control group. This study found a three-month-sustained effect of positive changes in knowledge and skill from participants who undertook a nurse-led community-based stroke prevention programme. Effective educational intervention by professional nurses helped clients integrate their learned knowledge into their real-life practice. This empowering, that is, the

Theory and experiment on charging and discharging a capacitor through a reverse-biased diode

Science.gov (United States)

Roy, Arijit; Mallick, Abhishek; Adhikari, Aparna; Guin, Priyanka; Chatterjee, Dibyendu

2018-06-01

The beauty of a diode lies in its voltage-dependent nonlinear resistance. The voltage on a charging and discharging capacitor through a reverse-biased diode is calculated from basic equations and is found to be in good agreement with experimental measurements. Instead of the exponential dependence of charging and discharging voltages with time for a resistor-capacitor circuit, a linear time dependence is found when the resistor is replaced by a reverse-biased diode. Thus, well controlled positive and negative ramp voltages are obtained from the charging and discharging diode-capacitor circuits. This experiment can readily be performed in an introductory physics and electronics laboratory.

The Impact of Experiential Avoidance on the Inference of Characters' Emotions: Evidence for an Emotional Processing Bias.

Science.gov (United States)

Pickett, Scott M; Kurby, Christopher A

2010-12-01

Experiential avoidance is a functional class of maladaptive strategies that contribute to the development and maintenance of psychopathology. Although previous research has demonstrated group differences in the interpretation of aversive stimuli, there is limited work on the influence of experiential avoidance during the online processing of emotion. An experimental design investigated the influence of self-reported experiential avoidance during emotion processing by assessing emotion inferences during the comprehension of narratives that imply different emotions. Results suggest that experiential avoidance is partially characterized by an emotional information processing bias. Specifically, individuals reporting higher experiential avoidance scores exhibited a bias towards activating negative emotion inferences, whereas individuals reporting lower experiential avoidance scores exhibited a bias towards activating positive emotion inferences. Minimal emotional inference was observed for the non-bias affective valence. Findings are discussed in terms of the implications of experiential avoidance as a cognitive vulnerability for psychopathology.

Maximum magnitude in bias-dependent spin accumulation signals of CoFe/MgO/Si on insulator devices

International Nuclear Information System (INIS)

Ishikawa, M.; Sugiyama, H.; Inokuchi, T.; Tanamoto, T.; Saito, Y.; Hamaya, K.; Tezuka, N.

2013-01-01

We study in detail how the bias voltage (V bias ) and interface resistance (RA) depend on the magnitude of spin accumulation signals (|ΔV| or |ΔV|/I, where I is current) as detected by three-terminal Hanle measurements in CoFe/MgO/Si on insulator (SOI) devices with various MgO layer thicknesses and SOI carrier densities. We find the apparent maximum magnitude of spin polarization as a function of V bias and the correlation between the magnitude of spin accumulation signals and the shape of differential conductance (dI/dV) curves within the framework of the standard spin diffusion model. All of the experimental results can be explained by taking into account the density of states (DOS) in CoFe under the influence of the applied V bias and the quality of MgO tunnel barrier. These results indicate that it is important to consider the DOS of the ferromagnetic materials under the influence of an applied V bias and the quality of tunnel barrier when observing large spin accumulation signals in Si

Specific depletion of Ly6C(hi) inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

Science.gov (United States)

Schumak, Beatrix; Klocke, Katrin; Kuepper, Janina M; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6C(hi) inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi) inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi) inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

Interpreting trial results following use of different intention-to-treat approaches for preventing attrition bias

DEFF Research Database (Denmark)

Dossing, Anna; Tarp, Simon; Furst, Daniel E

2014-01-01

10 biological and targeted drugs based on collections of trials that would correspond to 10 individual meta-analyses. ETHICS AND DISSEMINATION: This study will enhance transparency for evaluating mITT treatment effects described in meta-analyses. The intended audience will include healthcare...... concerns when executing different mITT approaches in meta-analyses. METHODS AND ANALYSIS: Using meta-epidemiology on randomised trials considered less prone to bias (ie, good internal validity) and assessing biological or targeted agents in patients with rheumatoid arthritis, we will meta-analyse data from...

Attribution bias and social anxiety in schizophrenia

Directory of Open Access Journals (Sweden)

Amelie M. Achim

2016-06-01

Full Text Available Studies on attribution biases in schizophrenia have produced mixed results, whereas such biases have been more consistently reported in people with anxiety disorders. Anxiety comorbidities are frequent in schizophrenia, in particular social anxiety disorder, which could influence their patterns of attribution biases. The objective of the present study was thus to determine if individuals with schizophrenia and a comorbid social anxiety disorder (SZ+ show distinct attribution biases as compared with individuals with schizophrenia without social anxiety (SZ− and healthy controls. Attribution biases were assessed with the Internal, Personal, and Situational Attributions Questionnaire in 41 individual with schizophrenia and 41 healthy controls. Results revealed the lack of the normal externalizing bias in SZ+, whereas SZ− did not significantly differ from healthy controls on this dimension. The personalizing bias was not influenced by social anxiety but was in contrast linked with delusions, with a greater personalizing bias in individuals with current delusions. Future studies on attribution biases in schizophrenia should carefully document symptom presentation, including social anxiety.

Semi-Targeted Analysis of Complex Matrices by ESI FT-ICR MS or How an Experimental Bias may be Used as an Analytical Tool

Science.gov (United States)

Hertzog, Jasmine; Carré, Vincent; Dufour, Anthony; Aubriet, Frédéric

2018-03-01

Ammonia is well suited to favor deprotonation process in electrospray ionization mass spectrometry (ESI-MS) to increase the formation of [M - H]-. Nevertheless, NH3 may react with carbonyl compounds (aldehyde, ketone) and bias the composition description of the investigated sample. This is of significant importance in the study of complex mixture such as oil or bio-oil. To assess the ability of primary amines to form imines with carbonyl compounds during the ESI-MS process, two aldehydes (vanillin and cinnamaldehyde) and two ketones (butyrophenone and trihydroxyacetophenone) have been infused in an ESI source with ammonia and two different amines (aniline and 3-chloronaniline). The (+) ESI-MS analyses have demonstrated the formation of imine whatever the considered carbonyl compound and the used primary amine, the structure of which was extensively studied by tandem mass spectrometry. Thus, it has been established that the addition of ammonia, in the solution infused in an ESI source, may alter the composition description of a complex mixture and leads to misinterpretations due to the formation of imines. Nevertheless, this experimental bias can be used to identify the carbonyl compounds in a pyrolysis bio-oil. As we demonstrated, infusion of the bio-oil with 3-chloroaniline in ESI source leads to specifically derivatized carbonyl compounds. Thanks to their chlorine isotopic pattern and the high mass measurement accuracy, (+) ESI Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) unambiguously highlighted them from the numerous CxHyOz bio-oil components. These results offer a new perspective into the detailed molecular structure of complex mixtures such as bio-oils. [Figure not available: see fulltext.

Preventive analgesia

DEFF Research Database (Denmark)

Dahl, Jørgen B; Kehlet, Henrik

2011-01-01

This paper will discuss the concepts of pre-emptive and preventive analgesia in acute and persistent postsurgical pain, based on the most recent experimental and clinical literature, with a special focus on injury-induced central sensitization and the development from acute to chronic pain. Recent...... of preventive analgesia for persistent postoperative pain are promising. However, clinicians must be aware of the demands for improved design of their clinical studies in order to get more conclusive answers regarding the different avenues for intervention. Summary: The concept of preventive analgesia is still...

Developmental precursors of young school-age children's hostile attribution bias.

Science.gov (United States)

Choe, Daniel Ewon; Lane, Jonathan D; Grabell, Adam S; Olson, Sheryl L

2013-12-01

This prospective longitudinal study provides evidence of preschool-age precursors of hostile attribution bias in young school-age children, a topic that has received little empirical attention. We examined multiple risk domains, including laboratory and observational assessments of children's social-cognition, general cognitive functioning, effortful control, and peer aggression. Preschoolers (N = 231) with a more advanced theory-of-mind, better emotion understanding, and higher IQ made fewer hostile attributions of intent in the early school years. Further exploration of these significant predictors revealed that only certain components of these capacities (i.e., nonstereotypical emotion understanding, false-belief explanation, and verbal IQ) were robust predictors of a hostile attribution bias in young school-age children and were especially strong predictors among children with more advanced effortful control. These relations were prospective in nature-the effects of preschool variables persisted after accounting for similar variables at school age. We conclude by discussing the implications of our findings for future research and prevention. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Cross-Cultural Study of Information Processing Biases in Chronic Fatigue Syndrome: Comparison of Dutch and UK Chronic Fatigue Patients.

Science.gov (United States)

Hughes, Alicia M; Hirsch, Colette R; Nikolaus, Stephanie; Chalder, Trudie; Knoop, Hans; Moss-Morris, Rona

2018-02-01

This study aims to replicate a UK study, with a Dutch sample to explore whether attention and interpretation biases and general attentional control deficits in chronic fatigue syndrome (CFS) are similar across populations and cultures. Thirty eight Dutch CFS participants were compared to 52 CFS and 51 healthy participants recruited from the UK. Participants completed self-report measures of symptoms, functioning, and mood, as well as three experimental tasks (i) visual-probe task measuring attentional bias to illness (somatic symptoms and disability) versus neutral words, (ii) interpretive bias task measuring positive versus somatic interpretations of ambiguous information, and (iii) the Attention Network Test measuring general attentional control. Compared to controls, Dutch and UK participants with CFS showed a significant attentional bias for illness-related words and were significantly more likely to interpret ambiguous information in a somatic way. These effects were not moderated by attentional control. There were no significant differences between the Dutch and UK CFS groups on attentional bias, interpretation bias, or attentional control scores. This study replicated the main findings of the UK study, with a Dutch CFS population, indicating that across these two cultures, people with CFS demonstrate biases in how somatic information is attended to and interpreted. These illness-specific biases appear to be unrelated to general attentional control deficits.

Categorizing Biases in High-Confidence High-Throughput Protein-Protein Interaction Data Sets*

Science.gov (United States)

Yu, Xueping; Ivanic, Joseph; Memišević, Vesna; Wallqvist, Anders; Reifman, Jaques

2011-01-01

We characterized and evaluated the functional attributes of three yeast high-confidence protein-protein interaction data sets derived from affinity purification/mass spectrometry, protein-fragment complementation assay, and yeast two-hybrid experiments. The interacting proteins retrieved from these data sets formed distinct, partially overlapping sets with different protein-protein interaction characteristics. These differences were primarily a function of the deployed experimental technologies used to recover these interactions. This affected the total coverage of interactions and was especially evident in the recovery of interactions among different functional classes of proteins. We found that the interaction data obtained by the yeast two-hybrid method was the least biased toward any particular functional characterization. In contrast, interacting proteins in the affinity purification/mass spectrometry and protein-fragment complementation assay data sets were over- and under-represented among distinct and different functional categories. We delineated how these differences affected protein complex organization in the network of interactions, in particular for strongly interacting complexes (e.g. RNA and protein synthesis) versus weak and transient interacting complexes (e.g. protein transport). We quantified methodological differences in detecting protein interactions from larger protein complexes, in the correlation of protein abundance among interacting proteins, and in their connectivity of essential proteins. In the latter case, we showed that minimizing inherent methodology biases removed many of the ambiguous conclusions about protein essentiality and protein connectivity. We used these findings to rationalize how biological insights obtained by analyzing data sets originating from different sources sometimes do not agree or may even contradict each other. An important corollary of this work was that discrepancies in biological insights did not

Biased Brownian dynamics for rate constant calculation.

OpenAIRE

Zou, G; Skeel, R D; Subramaniam, S

2000-01-01

An enhanced sampling method-biased Brownian dynamics-is developed for the calculation of diffusion-limited biomolecular association reaction rates with high energy or entropy barriers. Biased Brownian dynamics introduces a biasing force in addition to the electrostatic force between the reactants, and it associates a probability weight with each trajectory. A simulation loses weight when movement is along the biasing force and gains weight when movement is against the biasing force. The sampl...

Attentional Bias Associated with Habitual Self-Stigma in People with Mental Illness.

Science.gov (United States)

Chan, Kevin K S; Mak, Winnie W S

2015-01-01

As habitual self-stigma can have a tremendous negative impact on people with mental illness, it is of paramount importance to identify its risk factors. The present study aims to examine the potential contributory role of attentional bias in habitual self-stigma. People with mental illness having strong (n = 47) and weak (n = 47) habitual self-stigma completed a computerized emotional Stroop task which included stigma-related, positive, and non-affective words as stimuli. The strong habit group was found to exhibit faster color-naming of stigma-related words (compared to non-affective words), whereas the weak habit group showed no difference in the speed of response to different stimuli. These findings suggest that people with stronger habitual self-stigma may be more able to ignore the semantic meaning of stigma-related words and focus on the color-naming task. Moreover, people with stronger habitual self-stigma may have greater attentional avoidance of stigma-related material. The present study is the first to demonstrate a specific relationship between habitual self-stigma and biased processing of stigma-related information. In order to further determine the role and the nature of attentional bias in habitual self-stigma, future research should employ a broader range of experimental paradigms and measurement techniques to examine stigma-related attentional bias in people with mental illness.

The generalizability of gender bias: Testing the effects of contextual, explicit, and implicit sexism on labor arbitration decisions.

Science.gov (United States)

Girvan, Erik J; Deason, Grace; Borgida, Eugene

2015-10-01

Decades of social-psychological research show that gender bias can result from features of the social context and from individual-level psychological predispositions. Do these sources of bias impact legal decisions, which are frequently made by people subject to factors that have been proposed to reduce bias (training and accountability)? To answer the question, we examined the potential for 3 major social-psychological theories of gender bias (role-congruity theory, ambivalent sexism, and implicit bias) to predict outcomes of labor arbitration decisions. In the first study, undergraduate students and professional arbitrators made decisions about 2 mock arbitration cases in which the gender of the employee-grievants was experimentally manipulated. Student participants' decisions showed the predicted gender bias, whereas the decisions of experienced professionals did not. Individual-level attitudes did not predict the extent of the observed bias and accountability did not attenuate it. In the second study, arbitrators' explicit and implicit gender attitudes were significant predictors of their decisions in published cases. The laboratory and field results suggest that context, expertise, and implicit and explicit attitudes are relevant to legal decision-making, but that laboratory experiments alone may not fully capture the nature of their effect on legal professionals' decisions in real cases. (c) 2015 APA, all rights reserved).

Mood As Cumulative Expectation Mismatch: A Test of Theory Based on Data from Non-verbal Cognitive Bias Tests

Directory of Open Access Journals (Sweden)

Camille M. C. Raoult

2017-12-01

Full Text Available Affective states are known to influence behavior and cognitive processes. To assess mood (moderately long-term affective states, the cognitive judgment bias test was developed and has been widely used in various animal species. However, little is known about how mood changes, how mood can be experimentally manipulated, and how mood then feeds back into cognitive judgment. A recent theory argues that mood reflects the cumulative impact of differences between obtained outcomes and expectations. Here expectations refer to an established context. Situations in which an established context fails to match an outcome are then perceived as mismatches of expectation and outcome. We take advantage of the large number of studies published on non-verbal cognitive bias tests in recent years (95 studies with a total of 162 independent tests to test whether cumulative mismatch could indeed have led to the observed mood changes. Based on a criteria list, we assessed whether mismatch had occurred with the experimental procedure used to induce mood (mood induction mismatch, or in the context of the non-verbal cognitive bias procedure (testing mismatch. For the mood induction mismatch, we scored the mismatch between the subjects’ potential expectations and the manipulations conducted for inducing mood whereas, for the testing mismatch, we scored mismatches that may have occurred during the actual testing. We then investigated whether these two types of mismatch can predict the actual outcome of the cognitive bias study. The present evaluation shows that mood induction mismatch cannot well predict the success of a cognitive bias test. On the other hand, testing mismatch can modulate or even inverse the expected outcome. We think, cognitive bias studies should more specifically aim at creating expectation mismatch while inducing mood states to test the cumulative mismatch theory more properly. Furthermore, testing mismatch should be avoided as much as possible

The coalitional value theory of antigay bias

NARCIS (Netherlands)

Winegard, Bo; Reynolds, Tania; Baumeister, Roy F.; Plant, E. Ashby

2016-01-01

Research indicates that antigay bias follows a specific pattern (and probably has throughout written history, at least in the West): (a) men evince more antigay bias than women; (b) men who belong to traditionally male coalitions evince more antigay bias than those who do not; (c) antigay bias is

Symmetry as Bias: Rediscovering Special Relativity

Science.gov (United States)

Lowry, Michael R.

1992-01-01

This paper describes a rational reconstruction of Einstein's discovery of special relativity, validated through an implementation: the Erlanger program. Einstein's discovery of special relativity revolutionized both the content of physics and the research strategy used by theoretical physicists. This research strategy entails a mutual bootstrapping process between a hypothesis space for biases, defined through different postulated symmetries of the universe, and a hypothesis space for physical theories. The invariance principle mutually constrains these two spaces. The invariance principle enables detecting when an evolving physical theory becomes inconsistent with its bias, and also when the biases for theories describing different phenomena are inconsistent. Structural properties of the invariance principle facilitate generating a new bias when an inconsistency is detected. After a new bias is generated. this principle facilitates reformulating the old, inconsistent theory by treating the latter as a limiting approximation. The structural properties of the invariance principle can be suitably generalized to other types of biases to enable primal-dual learning.

Judging attractiveness: Biases due to raters’ own attractiveness and intelligence

Directory of Open Access Journals (Sweden)

Stacy Yen-Lin Sim

2015-12-01

Full Text Available Tennis and Dabbs (1975 reported that physically attractive males showed a positivity bias when rating the attractiveness of others. The opposite pattern was observed for females. We attempted to replicate and extend these findings by: (1 using self-assessed attractiveness rather than the experimentally derived attractiveness measure used in previous research, (2 using face-to-face interactions with targets as opposed to using photographs, and (3 examining the effect of another ego-involving attribute: intelligence. Consistent with previous research, attractiveness judgments made by men, but not women, correlated positively with their own self-perceived level of attractiveness (r = .51, p < .001. Attractiveness judgments made by women, but not men, correlated negatively with their intelligence (r = −.32, p = .001. Judgments of attractiveness are thus biased by a rater’s own attributes (e.g. attractiveness and intelligence, but these effects are not generalizable across men and women raters, and may be driven by different mechanisms.

Anti-Bias Education: Reflections

Science.gov (United States)

Derman-Sparks, Louise

2011-01-01

It is 30 years since NAEYC published "Anti-Bias Curriculum Tools for Empowering Young Children" (Derman-Sparks & ABC Task Force, 1989). Since then, anti-bias education concepts have become part of the early childhood education (ECE) narrative in the United States and many other countries. It has brought a fresh way of thinking about…

Modality planning for preventing tunnel vision in crisis management

NARCIS (Netherlands)

Cao, Y.; Nijholt, Antinus; Theune, Mariët; van der Sluis, Ielka; Bachvarova, Yulia; Andre, Elisabeth

2008-01-01

Crisis management is a time-critical task with high uncertainty and high risk. Stress and cognitive overload often result in a set of bias in crisis manager’s situation understanding and information confirming processes, known as 'tunnel vision'. Aiming at preventing tunnel vision, we propose an

On the model-dependence of the relation between minimum-bias and inelastic proton-proton cross sections

International Nuclear Information System (INIS)

Ostapchenko, S.

2011-01-01

The model-dependence of the relation between the inelastic and various minimum-bias proton-proton cross sections is analyzed, paying a special attention to the sensitivity of minimum-bias triggers to diffractive collisions. Concentrating on the trigger selections of the ATLAS experiment, the measured cross sections are compared to predictions of a number of hadronic Monte Carlo models used in the cosmic ray field. It is demonstrated that the ATLAS results are able to discriminate between different models and between certain theoretical approaches for soft multi-particle production. On the other hand, the strong model-dependence of the selection efficiency of the minimum-bias triggers prevents one from inferring high mass diffraction rate from the discussed data. Moreover, the measured cross sections prove to be insensitive to the production of low mass diffractive states in proton-proton collisions. Consequently, a reliable determination of the total inelastic cross section requires forward proton tracking by a dedicated experiment.

Sampler bias -- Phase 1

International Nuclear Information System (INIS)

Blanchard, R.J.

1995-01-01

This documents Phase 1 determinations on sampler induced bias for four sampler types used in tank characterization. Each sampler, grab sampler or bottle-on-a-string, auger sampler, sludge sampler and universal sampler, is briefly discussed and their physical limits noted. Phase 2 of this document will define additional testing and analysis to further define Sampler Bias

Negativity Bias in Dangerous Drivers.

Directory of Open Access Journals (Sweden)

Jing Chai

Full Text Available The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes.

Religious Attitudes and Home Bias

OpenAIRE

C. Reggiani; G. Rossini

2008-01-01

Home bias affects trade in goods, services and financial assets. It is mostly generated by "natural" trade barriers. Among these dividers we may list many behavioral and sociological factors, such as status quo biases and a few kind of ‘embeddedness’. Unfortunately these factors are difficult to measure. An important part of ‘embeddedness’ may be related to religious attitudes. Is there any relation between economic home bias and religious attitudes at the individual tier? Our aim is to provi...

Placebo effect studies are susceptible to response bias and to other types of biases

DEFF Research Database (Denmark)

Hróbjartsson, Asbjørn; Kaptchuk, Ted J; Miller, Franklin G

2011-01-01

Investigations of the effect of placebo are often challenging to conduct and interpret. The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo....

A Comparison of attentional biases and memory biases in social phobia and major depression

NARCIS (Netherlands)

Rinck, M.; Becker, E.S.

2005-01-01

Cognitive processes play an important role in the etiology and maintenance of anxiety and depression. Current theories differ, however, in their predictions regarding the occurrence of attentional biases and memory biases in depression and anxiety. To allow for a systematic comparison of disorders

Survivor bias in Mendelian randomization analysis

DEFF Research Database (Denmark)

Vansteelandt, Stijn; Dukes, Oliver; Martinussen, Torben

2017-01-01

Mendelian randomization studies employ genotypes as experimental handles to infer the effect of genetically modified exposures (e.g. vitamin D exposure) on disease outcomes (e.g. mortality). The statistical analysis of these studies makes use of the standard instrumental variables framework. Many...... of these studies focus on elderly populations, thereby ignoring the problem of left truncation, which arises due to the selection of study participants being conditional upon surviving up to the time of study onset. Such selection, in general, invalidates the assumptions on which the instrumental variables...... analysis rests. We show that Mendelian randomization studies of adult or elderly populations will therefore, in general, return biased estimates of the exposure effect when the considered genotype affects mortality; in contrast, standard tests of the causal null hypothesis that the exposure does not affect...

Experimenter gender and replicability in science.

Science.gov (United States)

Chapman, Colin D; Benedict, Christian; Schiöth, Helgi B

2018-01-01

There is a replication crisis spreading through the annals of scientific inquiry. Although some work has been carried out to uncover the roots of this issue, much remains unanswered. With this in mind, this paper investigates how the gender of the experimenter may affect experimental findings. Clinical trials are regularly carried out without any report of the experimenter's gender and with dubious knowledge of its influence. Consequently, significant biases caused by the experimenter's gender may lead researchers to conclude that therapeutics or other interventions are either overtreating or undertreating a variety of conditions. Bearing this in mind, this policy paper emphasizes the importance of reporting and controlling for experimenter gender in future research. As backdrop, it explores what we know about the role of experimenter gender in influencing laboratory results, suggests possible mechanisms, and suggests future areas of inquiry.

Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling.

Science.gov (United States)

Biro, Peter A

2013-02-01

Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.

Adaptable history biases in human perceptual decisions.

Science.gov (United States)

Abrahamyan, Arman; Silva, Laura Luz; Dakin, Steven C; Carandini, Matteo; Gardner, Justin L

2016-06-21

When making choices under conditions of perceptual uncertainty, past experience can play a vital role. However, it can also lead to biases that worsen decisions. Consistent with previous observations, we found that human choices are influenced by the success or failure of past choices even in a standard two-alternative detection task, where choice history is irrelevant. The typical bias was one that made the subject switch choices after a failure. These choice history biases led to poorer performance and were similar for observers in different countries. They were well captured by a simple logistic regression model that had been previously applied to describe psychophysical performance in mice. Such irrational biases seem at odds with the principles of reinforcement learning, which would predict exquisite adaptability to choice history. We therefore asked whether subjects could adapt their irrational biases following changes in trial order statistics. Adaptability was strong in the direction that confirmed a subject's default biases, but weaker in the opposite direction, so that existing biases could not be eradicated. We conclude that humans can adapt choice history biases, but cannot easily overcome existing biases even if irrational in the current context: adaptation is more sensitive to confirmatory than contradictory statistics.

Specific depletion of Ly6C(hi inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

Directory of Open Access Journals (Sweden)

Beatrix Schumak

Full Text Available Plasmodium berghei ANKA (PbA infection of C57BL/6 mice leads to experimental cerebral malaria (ECM that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb, we depleted in vivo Ly6C(hi inflammatory monocytes (by anti-CCR2, Ly6G+ neutrophils (by anti-Ly6G or both cell types (by anti-Gr1 during infection with Ovalbumin-transgenic PbA parasites (PbTg. Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

Platelet-biased stem cells reside at the apex of the haematopoietic stem-cell hierarchy.

Science.gov (United States)

Sanjuan-Pla, Alejandra; Macaulay, Iain C; Jensen, Christina T; Woll, Petter S; Luis, Tiago C; Mead, Adam; Moore, Susan; Carella, Cintia; Matsuoka, Sahoko; Bouriez Jones, Tiphaine; Chowdhury, Onima; Stenson, Laura; Lutteropp, Michael; Green, Joanna C A; Facchini, Raffaella; Boukarabila, Hanane; Grover, Amit; Gambardella, Adriana; Thongjuea, Supat; Carrelha, Joana; Tarrant, Paul; Atkinson, Deborah; Clark, Sally-Ann; Nerlov, Claus; Jacobsen, Sten Eirik W

2013-10-10

The blood system is maintained by a small pool of haematopoietic stem cells (HSCs), which are required and sufficient for replenishing all human blood cell lineages at millions of cells per second throughout life. Megakaryocytes in the bone marrow are responsible for the continuous production of platelets in the blood, crucial for preventing bleeding--a common and life-threatening side effect of many cancer therapies--and major efforts are focused at identifying the most suitable cellular and molecular targets to enhance platelet production after bone marrow transplantation or chemotherapy. Although it has become clear that distinct HSC subsets exist that are stably biased towards the generation of lymphoid or myeloid blood cells, we are yet to learn whether other types of lineage-biased HSC exist or understand their inter-relationships and how differently lineage-biased HSCs are generated and maintained. The functional relevance of notable phenotypic and molecular similarities between megakaryocytes and bone marrow cells with an HSC cell-surface phenotype remains unclear. Here we identify and prospectively isolate a molecularly and functionally distinct mouse HSC subset primed for platelet-specific gene expression, with enhanced propensity for short- and long-term reconstitution of platelets. Maintenance of platelet-biased HSCs crucially depends on thrombopoietin, the primary extrinsic regulator of platelet development. Platelet-primed HSCs also frequently have a long-term myeloid lineage bias, can self-renew and give rise to lymphoid-biased HSCs. These findings show that HSC subtypes can be organized into a cellular hierarchy, with platelet-primed HSCs at the apex. They also demonstrate that molecular and functional priming for platelet development initiates already in a distinct HSC population. The identification of a platelet-primed HSC population should enable the rational design of therapies enhancing platelet output.

Domain wall engineering through exchange bias

International Nuclear Information System (INIS)

Albisetti, E.; Petti, D.

2016-01-01

The control of the structure and position of magnetic domain walls is at the basis of the development of different magnetic devices and architectures. Several nanofabrication techniques have been proposed to geometrically confine and shape domain wall structures; however, a fine tuning of the position and micromagnetic configuration is hardly achieved, especially in continuous films. This work shows that, by controlling the unidirectional anisotropy of a continuous ferromagnetic film through exchange bias, domain walls whose spin arrangement is generally not favored by dipolar and exchange interactions can be created. Micromagnetic simulations reveal that the domain wall width, position and profile can be tuned by establishing an abrupt change in the direction and magnitude of the exchange bias field set in the system. - Highlights: • Micromagnetic simulations study domain walls in exchange biased thin films. • Novel domain wall configurations can be stabilized via exchange bias. • Domain walls nucleate at the boundary of regions with different exchange bias. • Domain wall width and spin profile are controlled by tuning the exchange bias.

When we should worry more: using cognitive bias modification to drive adaptive health behaviour.

Science.gov (United States)

Notebaert, Lies; Chrystal, Jessica; Clarke, Patrick J F; Holmes, Emily A; MacLeod, Colin

2014-01-01

A lack of behavioural engagement in health promotion or disease prevention is a problem across many health domains. In these cases where people face a genuine danger, a reduced focus on threat and low levels of anxiety or worry are maladaptive in terms of promoting protection or prevention behaviour. Therefore, it is possible that increasing the processing of threat will increase worry and thereby enhance engagement in adaptive behaviour. Laboratory studies have shown that cognitive bias modification (CBM) can increase or decrease anxiety and worry when increased versus decreased processing of threat is encouraged. In the current study, CBM for interpretation (CBM-I) is used to target engagement in sun protection behaviour. The goal was to investigate whether inducing a negative rather than a positive interpretation bias for physical threat information can enhance worry elicited when viewing a health campaign video (warning against melanoma skin cancer), and consequently lead to more adaptive behaviour (sun protection). Participants were successfully trained to either adopt a positive or negative interpretation bias using physical threat scenarios. However, contrary to expectations results showed that participants in the positive training condition reported higher levels of worry elicited by the melanoma video than participants in the negative training condition. Video elicited worry was, however, positively correlated with a measure of engagement in sun protection behaviour, suggesting that higher levels of worry do promote adaptive behaviour. These findings imply that more research is needed to determine under which conditions increased versus decreased processing of threat can drive adaptive worry. Various potential explanations for the current findings and suggestions for future research are discussed.

How we categorize objects is related to how we remember them: The shape bias as a memory bias.

Science.gov (United States)

Vlach, Haley A

2016-12-01

The "shape bias" describes the phenomenon that, after a certain point in development, children and adults generalize object categories based on shape to a greater degree than other perceptual features. The focus of research on the shape bias has been to examine the types of information that learners attend to in one moment in time. The current work takes a different approach by examining whether learners' categorical biases are related to their retention of information across time. In three experiments, children's (N=72) and adults' (N=240) memory performance for features of objects was examined in relation to their categorical biases. The results of these experiments demonstrated that the number of shape matches chosen during the shape bias task significantly predicted shape memory. Moreover, children and adults with a shape bias were more likely to remember the shape of objects than the color and size of objects. Taken together, this work suggests that the development of a shape bias may engender better memory for shape information. Copyright © 2016 Elsevier Inc. All rights reserved.

Is bias in the eye of the beholder? A vignette study to assess recognition of cognitive biases in clinical case workups.

Science.gov (United States)

Zwaan, Laura; Monteiro, Sandra; Sherbino, Jonathan; Ilgen, Jonathan; Howey, Betty; Norman, Geoffrey

2017-02-01

Many authors have implicated cognitive biases as a primary cause of diagnostic error. If this is so, then physicians already familiar with common cognitive biases should consistently identify biases present in a clinical workup. The aim of this paper is to determine whether physicians agree on the presence or absence of particular biases in a clinical case workup and how case outcome knowledge affects bias identification. We conducted a web survey of 37 physicians. Each participant read eight cases and listed which biases were present from a list provided. In half the cases the outcome implied a correct diagnosis; in the other half, it implied an incorrect diagnosis. We compared the number of biases identified when the outcome implied a correct or incorrect primary diagnosis. Additionally, the agreement among participants about presence or absence of specific biases was assessed. When the case outcome implied a correct diagnosis, an average of 1.75 cognitive biases were reported; when incorrect, 3.45 biases (F=71.3, p<0.00001). Individual biases were reported from 73% to 125% more often when an incorrect diagnosis was implied. There was no agreement on presence or absence of individual biases, with κ ranging from 0.000 to 0.044. Individual physicians are unable to agree on the presence or absence of individual cognitive biases. Their judgements are heavily influenced by hindsight bias; when the outcome implies a diagnostic error, twice as many biases are identified. The results present challenges for current error reduction strategies based on identification of cognitive biases. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Framing obesity a disease: Indirect effects of affect and controllability beliefs on weight bias.

Science.gov (United States)

Nutter, Sarah; Alberga, Angela S; MacInnis, Cara; Ellard, John H; Russell-Mayhew, Shelly

2018-05-24

Obesity has been declared a disease by the American and Canadian Medical Associations. Although these declarations sparked much debate as to the impact of framing obesity as a disease on weight bias, strong empirical research is needed to examine this impact. The current study examined the impact of framing obesity a disease on weight bias, focusing on moderating and mediating processes. A sample of 309 participants living in the United States or Canada was recruited from Crowdflower. Participants completed measures of demographics, ideology, general attitudes, and previous contact quality and quantity with people living with obesity. Participants then read one of three articles as part of an experimental manipulation framing obesity as a disease, obesity not as a disease, and a control article unrelated to obesity. Post-manipulation included measures of affect, disgust, empathy, blame, and weight bias. Orthogonal contrasts were used to compare the obesity-disease condition to the obesity-not-disease condition and control condition. The manipulation had a direct effect on affect (emotions), such that affect toward individuals with obesity was more positive in the obesity-disease condition than the obesity-not-disease and control condition combined. Exploration of moderating effects revealed that both the belief in a just world and weight satisfaction moderated the relationship between the obesity-disease manipulation and blame for obesity. Two models of indirect effects on weight bias were also examined, which demonstrated that the obesity-disease manipulation predicted less weight bias through more positive affect (model 1) as well as less weight bias through decreased blame among individuals high in belief in a just world (model 2). This study further highlights the complex effects of declaring obesity a disease, uncovering a new direction for future research into the role of affect as well as indirect effects of characterising obesity a disease on weight bias.

Maximizing potential impact of experimental research into cognitive processes in health psychology: A systematic approach to material development.

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Hughes, Alicia M; Gordon, Rola; Chalder, Trudie; Hirsch, Colette R; Moss-Morris, Rona

2016-11-01

There is an abundance of research into cognitive processing biases in clinical psychology including the potential for applying cognitive bias modification techniques to assess the causal role of biases in maintaining anxiety and depression. Within the health psychology field, there is burgeoning interest in applying these experimental methods to assess potential cognitive biases in relation to physical health conditions and health-related behaviours. Experimental research in these areas could inform theoretical development by enabling measurement of implicit cognitive processes that may underlie unhelpful illness beliefs and help drive health-related behaviours. However, to date, there has been no systematic approach to adapting existing experimental paradigms for use within physical health research. Many studies fail to report how materials were developed for the population of interest or have used untested materials developed ad hoc. The lack of protocol for developing stimuli specificity has contributed to large heterogeneity in methodologies and findings. In this article, we emphasize the need for standardized methods for stimuli development and replication in experimental work, particularly as it extends beyond its original anxiety and depression scope to other physical conditions. We briefly describe the paradigms commonly used to assess cognitive biases in attention and interpretation and then describe the steps involved in comprehensive/robust stimuli development for attention and interpretation paradigms using illustrative examples from two conditions: chronic fatigue syndrome and breast cancer. This article highlights the value of preforming rigorous stimuli development and provides tools to aid researchers engage in this process. We believe this work is worthwhile to establish a body of high-quality and replicable experimental research within the health psychology literature. Statement of contribution What is already known on this subject? Cognitive

Observation of resonant symmetry lifting by an effective bias field in a parametrically modulated atomic trap

International Nuclear Information System (INIS)

Kim, Yonghee; Heo, Myoung-Sun; Moon, Geol; Kim, Ji-Hyoun; Jhe, Wonho; Noh, Heung-Ryoul

2010-01-01

We experimentally demonstrate resonant symmetry lifting in a parametrically modulated magneto-optical trap of cold 85 Rb atoms. This is achieved by applying a weak additional modulation at half the frequency of the strong parametric modulation, which acts as an effective static bias field to the system. We measure the system response by varying the amplitude of the additional fictitious bias as well as the relative phase between the bias and the parametric drive, and the results are in good agreement with theory. The additional modulation provides an additional degree of freedom to control the system, which is useful for investigating system properties such as susceptibility, dynamic response, and related critical phenomena. We also have measured the amplitude of the response to higher harmonics of the additional modulation frequency, which allows more precise understanding of the system dynamics.

Culturally Targeted Strategies for Diabetes Prevention in Minority Populations: A Systematic Review and Framework

Science.gov (United States)

Lagisetty, Pooja A.; Priyadarshini, Shubadra; Terrell, Stephanie; Hamati, Mary; Landgraf, Jessica; Chopra, Vineet; Heisler, Michele

2017-01-01

Purpose The purpose of this study is to (a) assess the effectiveness of culturally tailored diabetes prevention interventions in minority populations and (b) develop a novel framework to characterize four key domains of culturally tailored interventions. Prevention strategies specifically tailored to the culture of ethnic minority patients may help reduce the incidence of diabetes. Methods We searched PubMed, EMBASE, and CINAHL for English-language, randomized controlled trials (RCTs) or quasi-experimental (QE) trials testing culturally tailored interventions to prevent diabetes in minority populations. Two reviewers independently extracted data and assessed risk of bias. Inductive thematic analysis was used to develop a framework with four domains (FiLLM: Facilitating [i.e., delivering] Interventions through Language, Location and Message). The framework was used to assess the overall effectiveness of culturally tailored interventions. Results Thirty-four trials met eligibility criteria. Twelve studies were randomized controlled trials, and 22 were quasi-experimental trials. Twenty-five out of 34 studies (74%) that used cultural tailoring demonstrated significantly improved Hemoglobin A1C, fasting glucose, and/or weight loss. Of the 25 successful interventions, 21 (84%) incorporated at least three culturally targeted domains. Seven studies used all four domains and were all successful. The least utilized domain was delivery (4/34) of the intervention’s key educational message. Conclusions Culturally tailoring interventions across the four domains of facilitators, language, location, and messaging can be effective in improving risk factors for progression to diabetes among ethnic minority groups. Future studies should evaluate how specific tailoring approaches work compared to usual care as well as comparative effectiveness of each tailoring domain. Registration (PROSPERO registration: CRD42015016914) PMID:28118127

Motivational Reasons for Biased Decisions: The Sunk-Cost Effect’s Instrumental Rationality

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Markus Domeier

2018-05-01

Full Text Available The present study describes the mechanism of need regulation, which accompanies the so-called “biased” decisions. We hypothesized an unconscious urge for psychological need satisfaction as the trigger for cognitive biases. In an experimental study (N = 106, participants had the opportunity to win money in a functionality test. In the test, they could either use the solution they had developed (sunk cost or an alternative solution that offered a higher probability of winning. The selection of the sunk-cost option (SCO was the most chosen option, supporting the hypothesis of this study. The reason behind the majority of participants choosing the SCO seemed to be the satisfaction of psychological needs, despite a reduced chance of winning money. An intervention, which aimed at triggering self-reflection, had no impact on the decision. The findings of this study contribute to the discussion on the reasons for cognitive biases and their formation in the human mind. Moreover, it discusses the application of the label “irrational” for biased decisions and proposes reasons for instrumental rationality, which exist at an unconscious, need-regulative level.

Negative evaluation bias for positive self-referential information in borderline personality disorder.

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Dorina Winter

Full Text Available Previous research has suggested that patients meeting criteria for borderline personality disorder (BPD display altered self-related information processing. However, experimental studies on dysfunctional self-referential information processing in BPD are rare. In this study, BPD patients (N = 30 and healthy control participants (N = 30 judged positive, neutral, and negative words in terms of emotional valence. Referential processing was manipulated by a preceding self-referential pronoun, an other-referential pronoun, or no referential context. Subsequently, patients and participants completed a free recall and recognition task. BPD patients judged positive and neutral words as more negative than healthy control participants when the words had self-reference or no reference. In BPD patients, these biases were significantly correlated with self-reported attributional style, particularly for negative events, but unrelated to measures of depressive mood. However, BPD patients did not differ from healthy control participants in a subsequent free recall task and a recognition task. Our findings point to a negative evaluation bias for positive, self-referential information in BPD. This bias did not affect the storage of information in memory, but may be related to self-attributions of negative events in everyday life in BPD.

Toxicology research for precautionary decision-making and the role of Human & Experimental Toxicology

DEFF Research Database (Denmark)

Grandjean, P

2015-01-01

being the strict criteria for scientific proof usually required for decision-making in regard to prevention. The present study ascertains the coverage of environmental chemicals in four volumes of Human & Experimental Toxicology and the presentation and interpretation of research findings in published...... is particularly prone to bias because of the known paucity of false positives and, in particular, the existence of a vast number of toxic hazards which by default are considered innocuous due to lack of documentation. The Precautionary Principle could inspire decision-making on the basis of incomplete...... articles. Links in SciFinder showed that the 530 articles published in four selected volumes between 1984 and 2014 primarily dealt with metals (126 links) and other toxicants that have received substantial attention in the past. Thirteen compounds identified by US authorities in 2006 as high...

AC bias operation of the perpendicular biased ferrite tuned cavity for the TRIUMF KAON Factory booster synchrotron

International Nuclear Information System (INIS)

Poirier, R.L.; Enegren, T.A.; Enchevich, I.B.

1991-05-01

The RF cavity for the booster synchrotron requires a frequency swing from 46 MHz at a repetition rate of 50 Hz and a maximum accelerating gap voltage of 65 kV. A DC biased prototype cavity built at LANL using perpendicular-biased yttrium-garnet ferrites, rather than the more conventional parallel-biased NiZn ferrites, has now undergone major reconstruction at TRIUMF for AC bias operation. RF signal level measurements have shown that the frequency swing at a repetition rate of 50 Hz can be accomplished and still handle the eddy current losses in the cavity structures with minimal effect on the magnetizing field. The prototype cavity is now undergoing high power RF tests with full power AC bias operation. The results of these tests and operational experience is reported. (Author) ref., 6 figs

Disclosing bias in bisulfite assay: MethPrimers underestimate high DNA methylation.

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Andrea Fuso

Full Text Available Discordant results obtained in bisulfite assays using MethPrimers (PCR primers designed using MethPrimer software or assuming that non-CpGs cytosines are non methylated versus primers insensitive to cytosine methylation lead us to hypothesize a technical bias. We therefore used the two kinds of primers to study different experimental models and methylation statuses. We demonstrated that MethPrimers negatively select hypermethylated DNA sequences in the PCR step of the bisulfite assay, resulting in CpG methylation underestimation and non-CpG methylation masking, failing to evidence differential methylation statuses. We also describe the characteristics of "Methylation-Insensitive Primers" (MIPs, having degenerated bases (G/A to cope with the uncertain C/U conversion. As CpG and non-CpG DNA methylation patterns are largely variable depending on the species, developmental stage, tissue and cell type, a variable extent of the bias is expected. The more the methylome is methylated, the greater is the extent of the bias, with a prevalent effect of non-CpG methylation. These findings suggest a revision of several DNA methylation patterns so far documented and also point out the necessity of applying unbiased analyses to the increasing number of epigenomic studies.

Reputation offsets trust judgments based on social biases among Airbnb users.

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Abrahao, Bruno; Parigi, Paolo; Gupta, Alok; Cook, Karen S

2017-09-12

To provide social exchange on a global level, sharing-economy companies leverage interpersonal trust between their members on a scale unimaginable even a few years ago. A challenge to this mission is the presence of social biases among a large heterogeneous and independent population of users, a factor that hinders the growth of these services. We investigate whether and to what extent a sharing-economy platform can design artificially engineered features, such as reputation systems, to override people's natural tendency to base judgments of trustworthiness on social biases. We focus on the common tendency to trust others who are similar (i.e., homophily) as a source of bias. We test this argument through an online experiment with 8,906 users of Airbnb, a leading hospitality company in the sharing economy. The experiment is based on an interpersonal investment game, in which we vary the characteristics of recipients to study trust through the interplay between homophily and reputation. Our findings show that reputation systems can significantly increase the trust between dissimilar users and that risk aversion has an inverse relationship with trust given high reputation. We also present evidence that our experimental findings are confirmed by analyses of 1 million actual hospitality interactions among users of Airbnb.

delta-biased Josephson tunnel junctions

DEFF Research Database (Denmark)

Monaco, R.; Mygind, Jesper; Koshelet, V.

2010-01-01

Abstract: The behavior of a long Josephson tunnel junction drastically depends on the distribution of the dc bias current. We investigate the case in which the bias current is fed in the central point of a one-dimensional junction. Such junction configuration has been recently used to detect...... the persistent currents circulating in a superconducting loop. Analytical and numerical results indicate that the presence of fractional vortices leads to remarkable differences from the conventional case of uniformly distributed dc bias current. The theoretical findings are supported by detailed measurements...

Dipole-induced exchange bias.

Science.gov (United States)

Torres, Felipe; Morales, Rafael; Schuller, Ivan K; Kiwi, Miguel

2017-11-09

The discovery of dipole-induced exchange bias (EB), switching from negative to positive sign, is reported in systems where the antiferromagnet and the ferromagnet are separated by a paramagnetic spacer (AFM-PM-FM). The magnitude and sign of the EB is determined by the cooling field strength and the PM thickness. The same cooling field yields negative EB for thin spacers, and positive EB for thicker ones. The EB decay profile as a function of the spacer thickness, and the change of sign, are attributed to long-ranged dipole coupling. Our model, which accounts quantitatively for the experimental results, ignores the short range interfacial exchange interactions of the usual EB theories. Instead, it retains solely the long range dipole field that allows for the coupling of the FM and AFM across the PM spacer. The experiments allow for novel switching capabilities of long range EB systems, while the theory allows description of the structures where the FM and AFM are not in atomic contact. The results provide a new approach to design novel interacting heterostructures.

The immitigable nature of assembly bias: the impact of halo definition on assembly bias

Science.gov (United States)

Villarreal, Antonio S.; Zentner, Andrew R.; Mao, Yao-Yuan; Purcell, Chris W.; van den Bosch, Frank C.; Diemer, Benedikt; Lange, Johannes U.; Wang, Kuan; Campbell, Duncan

2017-11-01

Dark matter halo clustering depends not only on halo mass, but also on other properties such as concentration and shape. This phenomenon is known broadly as assembly bias. We explore the dependence of assembly bias on halo definition, parametrized by spherical overdensity parameter, Δ. We summarize the strength of concentration-, shape-, and spin-dependent halo clustering as a function of halo mass and halo definition. Concentration-dependent clustering depends strongly on mass at all Δ. For conventional halo definitions (Δ ∼ 200 - 600 m), concentration-dependent clustering at low mass is driven by a population of haloes that is altered through interactions with neighbouring haloes. Concentration-dependent clustering can be greatly reduced through a mass-dependent halo definition with Δ ∼ 20 - 40 m for haloes with M200 m ≲ 1012 h-1M⊙. Smaller Δ implies larger radii and mitigates assembly bias at low mass by subsuming altered, so-called backsplash haloes into now larger host haloes. At higher masses (M200 m ≳ 1013 h-1M⊙) larger overdensities, Δ ≳ 600 m, are necessary. Shape- and spin-dependent clustering are significant for all halo definitions that we explore and exhibit a relatively weaker mass dependence. Generally, both the strength and the sense of assembly bias depend on halo definition, varying significantly even among common definitions. We identify no halo definition that mitigates all manifestations of assembly bias. A halo definition that mitigates assembly bias based on one halo property (e.g. concentration) must be mass dependent. The halo definitions that best mitigate concentration-dependent halo clustering do not coincide with the expected average splashback radii at fixed halo mass.

Insights on the evolution of metabolic networks of unicellular translationally biased organisms from transcriptomic data and sequence analysis.

Science.gov (United States)

Carbone, Alessandra; Madden, Richard

2005-10-01

Codon bias is related to metabolic functions in translationally biased organisms, and two facts are argued about. First, genes with high codon bias describe in meaningful ways the metabolic characteristics of the organism; important metabolic pathways corresponding to crucial characteristics of the lifestyle of an organism, such as photosynthesis, nitrification, anaerobic versus aerobic respiration, sulfate reduction, methanogenesis, and others, happen to involve especially biased genes. Second, gene transcriptional levels of sets of experiments representing a significant variation of biological conditions strikingly confirm, in the case of Saccharomyces cerevisiae, that metabolic preferences are detectable by purely statistical analysis: the high metabolic activity of yeast during fermentation is encoded in the high bias of enzymes involved in the associated pathways, suggesting that this genome was affected by a strong evolutionary pressure that favored a predominantly fermentative metabolism of yeast in the wild. The ensemble of metabolic pathways involving enzymes with high codon bias is rather well defined and remains consistent across many species, even those that have not been considered as translationally biased, such as Helicobacter pylori, for instance, reveal some weak form of translational bias for this genome. We provide numerical evidence, supported by experimental data, of these facts and conclude that the metabolic networks of translationally biased genomes, observable today as projections of eons of evolutionary pressure, can be analyzed numerically and predictions of the role of specific pathways during evolution can be derived. The new concepts of Comparative Pathway Index, used to compare organisms with respect to their metabolic networks, and Evolutionary Pathway Index, used to detect evolutionarily meaningful bias in the genetic code from transcriptional data, are introduced.

Is racial bias malleable? Whites' lay theories of racial bias predict divergent strategies for interracial interactions.

Science.gov (United States)

Neel, Rebecca; Shapiro, Jenessa R

2012-07-01

How do Whites approach interracial interactions? We argue that a previously unexamined factor-beliefs about the malleability of racial bias-guides Whites' strategies for difficult interracial interactions. We predicted and found that those who believe racial bias is malleable favor learning-oriented strategies such as taking the other person's perspective and trying to learn why an interaction is challenging, whereas those who believe racial bias is fixed favor performance-oriented strategies such as overcompensating in the interaction and trying to end the interaction as quickly as possible. Four studies support these predictions. Whether measured (Studies 1, 3, and 4) or manipulated (Study 2), beliefs that racial bias is fixed versus malleable yielded these divergent strategies for difficult interracial interactions. Furthermore, beliefs about the malleability of racial bias are distinct from related constructs (e.g., prejudice and motivations to respond without prejudice; Studies 1, 3, and 4) and influence self-reported (Studies 1-3) and actual (Study 4) strategies in imagined (Studies 1-2) and real (Studies 3-4) interracial interactions. Together, these findings demonstrate that beliefs about the malleability of racial bias influence Whites' approaches to and strategies within interracial interactions. PsycINFO Database Record (c) 2012 APA, all rights reserved

Pretreatment with Saccharomyces boulardii does not prevent the experimental mucositis in Swiss mice.

Science.gov (United States)

Maioli, Tatiani Uceli; de Melo Silva, Brenda; Dias, Michelle Nobre; Paiva, Nivea Carolina; Cardoso, Valbert Nascimento; Fernandes, Simone Odilia; Carneiro, Cláudia Martins; Dos Santos Martins, Flaviano; de Vasconcelos Generoso, Simone

2014-04-11

The antimetabolite chemotherapy 5-Fluorouracil is one of the most commonly prescribed drugs in clinical cancer treatment. Although this drug is not specific for cancer cells and also acts on healthy cells, it can cause mucositis, a common collateral effect. Dysbiosis has also been described in 5-fluorouracil-induced mucositis and is likely to contribute to the overall development of mucositis. In light of this theory, the use of probiotics could be a helpful strategy to alleviate mucositis. So the aim of this study was evaluate the impact of the probiotic Saccharomyces boulardii in a model of mucositis. After induced of mucositis, mice from the Mucositis groups showed a decrease in food consumption (p Saccharomyces boulardii did not reverse this effect (p > 0.05). Mucositis induced an increase in intestinal permeability and intestinal inflammation (p  0.05) in mice pretreated with S. boulardii. S. boulardii was not able to prevent the effects of experimental mucositis induced by 5- Fluorouracil.

Attention bias to emotional information in children as a function of maternal emotional disorders and maternal attention biases.

Science.gov (United States)

Waters, Allison M; Forrest, Kylee; Peters, Rosie-Mae; Bradley, Brendan P; Mogg, Karin

2015-03-01

Children of parents with emotional disorders have an increased risk for developing anxiety and depressive disorders. Yet the mechanisms that contribute to this increased risk are poorly understood. The present study aimed to examine attention biases in children as a function of maternal lifetime emotional disorders and maternal attention biases. There were 134 participants, including 38 high-risk children, and their mothers who had lifetime emotional disorders; and 29 low-risk children, and their mothers without lifetime emotional disorders. Mothers and children completed a visual probe task with emotional face pairs presented for 500 ms. Attention bias in children did not significantly differ solely as a function of whether or not their mothers had lifetime emotional disorders. However, attention bias in high-risk children was significantly related to their mothers' attention bias. Specifically, children of mothers with lifetime emotional disorders showed a greater negative attention bias if their mothers had a greater tendency to direct attention away from positive information. This study was cross-sectional in nature, and therefore unable to assess long-term predictive effects. Also, just one exposure duration of 500 ms was utilised. Attention bias for negative information is greater in offspring of mothers who have lifetime emotional disorders and a reduced positive bias, which could be a risk marker for the development of emotional disorders in children.

Food labels promote healthy choices by a decision bias in the amygdala.

Science.gov (United States)

Grabenhorst, Fabian; Schulte, Frank P; Maderwald, Stefan; Brand, Matthias

2013-07-01

Food labeling is the major health policy strategy to counter rising obesity rates. Based on traditional economic theory, such strategies assume that detailed nutritional information will necessarily help individuals make better, healthier choices. However, in contrast to the well-known utility of labels in food marketing, evidence for the efficacy of nutritional labeling is mixed. Psychological and behavioral economic theories suggest that successful marketing strategies activate automatic decision biases and emotions, which involve implicit emotional brain systems. Accordingly, simple, intuitive food labels that engage these neural systems could represent a promising approach for promoting healthier choices. Here we used functional MRI to investigate this possibility. Healthy, mildly hungry subjects performed a food evaluation task and a food choice task. The main experimental manipulation was to pair identical foods with simple labels that emphasized either taste benefits or health-related food properties. We found that such labels biased food evaluations in the amygdala, a core emotional brain system. When labels biased the amygdala's evaluations towards health-related food properties, the strength of this bias predicted behavioral shifts towards healthier choices. At the time of decision-making, amygdala activity encoded key decision variables, potentially reflecting active amygdala participation in food choice. Our findings underscore the potential utility of food labeling in health policy and indicate a principal role for emotional brain systems when labels guide food choices. Copyright © 2013 Elsevier Inc. All rights reserved.

Does neurocognitive function affect cognitive bias toward an emotional stimulus? Association between general attentional ability and attentional bias toward threat

Directory of Open Access Journals (Sweden)

Yuko eHakamata

2014-08-01

Full Text Available Background: Although poorer cognitive performance has been found to be associated with anxiety, it remains unclear whether neurocognitive function affects biased cognitive processing toward emotional information. We investigated whether general cognitive function evaluated with a standard neuropsychological test predicts biased cognition, focusing on attentional bias toward threat.Methods: One hundred and five healthy young adults completed a dot-probe task measuring attentional bias and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS measuring general cognitive function, which consists of five domains: immediate memory, visuospatial/constructional, language, attention, and delayed memory. Stepwise multiple regression analysis was performed to examine the relationships between attentional bias and cognitive function. Results: The attentional domain was the best predictor of attentional bias toward threat (β = -0.26, p = 0.006. Within the attentional domain, digit symbol coding was negatively correlated with attentional bias (r = -0.28, p = 0.005.Conclusions: The present study provides the first evidence that general attentional ability, which was assessed with a standard neuropsychological test, affects attentional bias toward threatening information. Individual cognitive profiles might be important for the measurement and modification of cognitive biases.

GOTHiC, a probabilistic model to resolve complex biases and to identify real interactions in Hi-C data.

Directory of Open Access Journals (Sweden)

Borbala Mifsud

Full Text Available Hi-C is one of the main methods for investigating spatial co-localisation of DNA in the nucleus. However, the raw sequencing data obtained from Hi-C experiments suffer from large biases and spurious contacts, making it difficult to identify true interactions. Existing methods use complex models to account for biases and do not provide a significance threshold for detecting interactions. Here we introduce a simple binomial probabilistic model that resolves complex biases and distinguishes between true and false interactions. The model corrects biases of known and unknown origin and yields a p-value for each interaction, providing a reliable threshold based on significance. We demonstrate this experimentally by testing the method against a random ligation dataset. Our method outperforms previous methods and provides a statistical framework for further data analysis, such as comparisons of Hi-C interactions between different conditions. GOTHiC is available as a BioConductor package (http://www.bioconductor.org/packages/release/bioc/html/GOTHiC.html.

GOTHiC, a probabilistic model to resolve complex biases and to identify real interactions in Hi-C data.

Science.gov (United States)

Mifsud, Borbala; Martincorena, Inigo; Darbo, Elodie; Sugar, Robert; Schoenfelder, Stefan; Fraser, Peter; Luscombe, Nicholas M

2017-01-01

Hi-C is one of the main methods for investigating spatial co-localisation of DNA in the nucleus. However, the raw sequencing data obtained from Hi-C experiments suffer from large biases and spurious contacts, making it difficult to identify true interactions. Existing methods use complex models to account for biases and do not provide a significance threshold for detecting interactions. Here we introduce a simple binomial probabilistic model that resolves complex biases and distinguishes between true and false interactions. The model corrects biases of known and unknown origin and yields a p-value for each interaction, providing a reliable threshold based on significance. We demonstrate this experimentally by testing the method against a random ligation dataset. Our method outperforms previous methods and provides a statistical framework for further data analysis, such as comparisons of Hi-C interactions between different conditions. GOTHiC is available as a BioConductor package (http://www.bioconductor.org/packages/release/bioc/html/GOTHiC.html).

Cognitive Biases and Nonverbal Cue Availability in Detecting Deception

Science.gov (United States)

Burgoon, Judee K.; Blair, J. Pete; Strom, Renee E.

2008-01-01

In potentially deceptive situations, people rely on mental shortcuts to help process information. These heuristic judgments are often biased and result in inaccurate assessments of sender veracity. Four such biases--truth bias, visual bias, demeanor bias, and expectancy violation bias--were examined in a judgment experiment that varied nonverbal…

The evolution of social learning rules: payoff-biased and frequency-dependent biased transmission.

Science.gov (United States)

Kendal, Jeremy; Giraldeau, Luc-Alain; Laland, Kevin

2009-09-21

Humans and other animals do not use social learning indiscriminately, rather, natural selection has favoured the evolution of social learning rules that make selective use of social learning to acquire relevant information in a changing environment. We present a gene-culture coevolutionary analysis of a small selection of such rules (unbiased social learning, payoff-biased social learning and frequency-dependent biased social learning, including conformism and anti-conformism) in a population of asocial learners where the environment is subject to a constant probability of change to a novel state. We define conditions under which each rule evolves to a genetically polymorphic equilibrium. We find that payoff-biased social learning may evolve under high levels of environmental variation if the fitness benefit associated with the acquired behaviour is either high or low but not of intermediate value. In contrast, both conformist and anti-conformist biases can become fixed when environment variation is low, whereupon the mean fitness in the population is higher than for a population of asocial learners. Our examination of the population dynamics reveals stable limit cycles under conformist and anti-conformist biases and some highly complex dynamics including chaos. Anti-conformists can out-compete conformists when conditions favour a low equilibrium frequency of the learned behaviour. We conclude that evolution, punctuated by the repeated successful invasion of different social learning rules, should continuously favour a reduction in the equilibrium frequency of asocial learning, and propose that, among competing social learning rules, the dominant rule will be the one that can persist with the lowest frequency of asocial learning.

Pulsed total dose damage effect experimental study on EPROM

International Nuclear Information System (INIS)

Luo Yinhong; Yao Zhibin; Zhang Fengqi; Guo Hongxia; Zhang Keying; Wang Yuanming; He Baoping

2011-01-01

Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

Study of the Dependency on Magnetic Field and Bias Voltage of an AC-Biased TES Microcalorimeter

Science.gov (United States)

Gottardi, L.; Bruijn, M.; denHartog, R.; Hoevers, H.; deKorte, P.; vanderKuur, J.; Linderman, M.; Adams, J.; Bailey, C.; Bandler, S.;

Bias and spread in extreme value theory measurements of probability of error

Science.gov (United States)

Smith, J. G.

1972-01-01

Extreme value theory is examined to explain the cause of the bias and spread in performance of communications systems characterized by low bit rates and high data reliability requirements, for cases in which underlying noise is Gaussian or perturbed Gaussian. Experimental verification is presented and procedures that minimize these effects are suggested. Even under these conditions, however, extreme value theory test results are not particularly more significant than bit error rate tests.

Critical Thinking and Cognitive Bias

Directory of Open Access Journals (Sweden)

Jeffrey Maynes

2015-05-01

Full Text Available Teaching critical thinking skill is a central pedagogical aim in many courses. These skills, it is hoped, will be both portable (applicable in a wide range of contexts and durable (not forgotten quickly. Yet, both of these virtues are challenged by pervasive and potent cognitive biases, such as motivated reasoning, false consensus bias and hindsight bias. In this paper, I argue that a focus on the development of metacognitive skill shows promise as a means to inculcate debiasing habits in students. Such habits will help students become more critical reasoners. I close with suggestions for implementing this strategy.

Numerical value biases sound localization.

Science.gov (United States)

Golob, Edward J; Lewald, Jörg; Getzmann, Stephan; Mock, Jeffrey R

2017-12-08

Speech recognition starts with representations of basic acoustic perceptual features and ends by categorizing the sound based on long-term memory for word meaning. However, little is known about whether the reverse pattern of lexical influences on basic perception can occur. We tested for a lexical influence on auditory spatial perception by having subjects make spatial judgments of number stimuli. Four experiments used pointing or left/right 2-alternative forced choice tasks to examine perceptual judgments of sound location as a function of digit magnitude (1-9). The main finding was that for stimuli presented near the median plane there was a linear left-to-right bias for localizing smaller-to-larger numbers. At lateral locations there was a central-eccentric location bias in the pointing task, and either a bias restricted to the smaller numbers (left side) or no significant number bias (right side). Prior number location also biased subsequent number judgments towards the opposite side. Findings support a lexical influence on auditory spatial perception, with a linear mapping near midline and more complex relations at lateral locations. Results may reflect coding of dedicated spatial channels, with two representing lateral positions in each hemispace, and the midline area represented by either their overlap or a separate third channel.

Non-Gaussian halo assembly bias

International Nuclear Information System (INIS)

Reid, Beth A.; Verde, Licia; Dolag, Klaus; Matarrese, Sabino; Moscardini, Lauro

2010-01-01

The strong dependence of the large-scale dark matter halo bias on the (local) non-Gaussianity parameter, f NL , offers a promising avenue towards constraining primordial non-Gaussianity with large-scale structure surveys. In this paper, we present the first detection of the dependence of the non-Gaussian halo bias on halo formation history using N-body simulations. We also present an analytic derivation of the expected signal based on the extended Press-Schechter formalism. In excellent agreement with our analytic prediction, we find that the halo formation history-dependent contribution to the non-Gaussian halo bias (which we call non-Gaussian halo assembly bias) can be factorized in a form approximately independent of redshift and halo mass. The correction to the non-Gaussian halo bias due to the halo formation history can be as large as 100%, with a suppression of the signal for recently formed halos and enhancement for old halos. This could in principle be a problem for realistic galaxy surveys if observational selection effects were to pick galaxies occupying only recently formed halos. Current semi-analytic galaxy formation models, for example, imply an enhancement in the expected signal of ∼ 23% and ∼ 48% for galaxies at z = 1 selected by stellar mass and star formation rate, respectively

Information filtering via biased heat conduction

Science.gov (United States)

Liu, Jian-Guo; Zhou, Tao; Guo, Qiang

2011-09-01

The process of heat conduction has recently found application in personalized recommendation [Zhou , Proc. Natl. Acad. Sci. USA PNASA60027-842410.1073/pnas.1000488107107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction, which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix, and Delicious datasets could be improved by 43.5%, 55.4% and 19.2%, respectively, compared with the standard heat conduction algorithm and also the diversity is increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering.

Fault-tolerant computing with biased-noise superconducting qubits: a case study

International Nuclear Information System (INIS)

Aliferis, P; Brito, F; DiVincenzo, D P; Steffen, M; Terhal, B M; Preskill, J

2009-01-01

We present a universal scheme of pulsed operations suitable for the IBM oscillator-stabilized flux qubit comprising the controlled-σ z (cphase) gate, single-qubit preparations and measurements. Based on numerical simulations, we argue that the error rates for these operations can be as low as about 0.5% and that noise is highly biased, with phase errors being stronger than all other types of errors by a factor of nearly 10 3 . In contrast, the design of a controlled-σ x (cnot) gate for this system with an error rate of less than about 1.2% seems extremely challenging. We propose a special encoding that exploits the noise bias allowing us to implement a logicalcnot gate where phase errors and all other types of errors have nearly balanced rates of about 0.4%. Our results illustrate how the design of an encoding scheme can be adjusted and optimized according to the available physical operations and the particular noise characteristics of experimental devices.

Nonlinear bias analysis and correction of microwave temperature sounder observations for FY-3C meteorological satellite

Science.gov (United States)

Hu, Taiyang; Lv, Rongchuan; Jin, Xu; Li, Hao; Chen, Wenxin

2018-01-01

The nonlinear bias analysis and correction of receiving channels in Chinese FY-3C meteorological satellite Microwave Temperature Sounder (MWTS) is a key technology of data assimilation for satellite radiance data. The thermal-vacuum chamber calibration data acquired from the MWTS can be analyzed to evaluate the instrument performance, including radiometric temperature sensitivity, channel nonlinearity and calibration accuracy. Especially, the nonlinearity parameters due to imperfect square-law detectors will be calculated from calibration data and further used to correct the nonlinear bias contributions of microwave receiving channels. Based upon the operational principles and thermalvacuum chamber calibration procedures of MWTS, this paper mainly focuses on the nonlinear bias analysis and correction methods for improving the calibration accuracy of the important instrument onboard FY-3C meteorological satellite, from the perspective of theoretical and experimental studies. Furthermore, a series of original results are presented to demonstrate the feasibility and significance of the methods.

Statistical methods for elimination of guarantee-time bias in cohort studies: a simulation study

Directory of Open Access Journals (Sweden)

In Sung Cho

2017-08-01

Full Text Available Abstract Background Aspirin has been considered to be beneficial in preventing cardiovascular diseases and cancer. Several pharmaco-epidemiology cohort studies have shown protective effects of aspirin on diseases using various statistical methods, with the Cox regression model being the most commonly used approach. However, there are some inherent limitations to the conventional Cox regression approach such as guarantee-time bias, resulting in an overestimation of the drug effect. To overcome such limitations, alternative approaches, such as the time-dependent Cox model and landmark methods have been proposed. This study aimed to compare the performance of three methods: Cox regression, time-dependent Cox model and landmark method with different landmark times in order to address the problem of guarantee-time bias. Methods Through statistical modeling and simulation studies, the performance of the above three methods were assessed in terms of type I error, bias, power, and mean squared error (MSE. In addition, the three statistical approaches were applied to a real data example from the Korean National Health Insurance Database. Effect of cumulative rosiglitazone dose on the risk of hepatocellular carcinoma was used as an example for illustration. Results In the simulated data, time-dependent Cox regression outperformed the landmark method in terms of bias and mean squared error but the type I error rates were similar. The results from real-data example showed the same patterns as the simulation findings. Conclusions While both time-dependent Cox regression model and landmark analysis are useful in resolving the problem of guarantee-time bias, time-dependent Cox regression is the most appropriate method for analyzing cumulative dose effects in pharmaco-epidemiological studies.

Influence of X and gamma radiation and bias conditions on dropout voltage of voltage regulators serial transistors

International Nuclear Information System (INIS)

Vukic, V.; Osmokrovic, P.; Stankovic, S.; Kovacevic, M.

2005-01-01

Research topic presented in this paper is degradation of characteristics of low-dropout voltage regulator's serial transistor during exposure of device to the ionizing radiation. Voltage regulators were exposed to X and γ radiation in two modes: without bias conditions, and with bias conditions and load. Tested circuits are representatives of the first and the second generation of low-dropout voltage regulators, with lateral and vertical PNP serial transistor: LM2940 and L4940. Experimental results of output voltage and serial dropout voltage change in function of total ionizing dose, during the medium-dose-rate exposure, were presented. (author) [sr

Minimum Bias Trigger in ATLAS

International Nuclear Information System (INIS)

Kwee, Regina

2010-01-01

Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |η| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presented. We also highlight the advantage of these triggers for particle correlation analyses. (author)

Is there bias in editorial choice? Yes

OpenAIRE

Moustafa, Khaled

2018-01-01

Nature has recently published a Correspondence claiming the absence of fame biases in the editorial choice. The topic is interesting and deserves a deeper analysis than it was presented because the reported brief analysis and its conclusion are somewhat biased for many reasons, some of them are discussed here. Since the editorial assessment is a form of peer-review, the biases reported on external peer-reviews would, thus, apply to the editorial assessment, too. The biases would be proportion...

Does the Superior Colliculus Control Perceptual Sensitivity or Choice Bias during Attention? Evidence from a Multialternative Decision Framework

Science.gov (United States)

Steinmetz, Nicholas A.; Moore, Tirin; Knudsen, Eric I.

2017-01-01

control) are poorly understood. Here, we introduce a model of multialternative decision making that distinguishes bias from sensitivity effects in attention tasks. With our model, we simulate experimental data from four seminal studies that microstimulated or inactivated a key attention-related midbrain structure, the superior colliculus (SC). We demonstrate that the experimental effects of SC manipulation are entirely consistent with the SC controlling attention by changing choice bias, thereby shedding new light on how the brain mediates attention. PMID:28100734

Effects of temporally biased watering on the nitrogen response of Chenopodium album

Science.gov (United States)

Kinugasa, Toshihiko; Hozumi, Yumi

2017-07-01

Plant growth responses to an increasing N deposition are stimulated by an increase in annual precipitation, but such a stimulation has not always been found. We hypothesized that the effect of precipitation on plant N responses can change with temporally biased precipitation: a plant N response will be suppressed when precipitation is lower in the late growing period because larger plants are more susceptible to water limitations. We grew Chenopodium album under a high and low N application level with three watering patterns while maintaining the total supplied watering amount during the experimental period: constant watering, low watering in the first period and high watering in the latter period, and high watering in the first period and low watering in the latter period. The watering pattern did not affect plant dry mass under low N conditions. The plant dry mass under high N conditions was reduced by low watering in the first period, but the reduction was fully compensated in the subsequent high watering period by the stimulation of photosynthesis. Low watering following high watering under high N conditions did not suppress plant growth, but partial leaf wilting was observed at the end of the experimental period. Finally, at the end of the experiment, the response of plant dry mass to N was not different among the watering patterns. We concluded that a plant's response to increasing N deposition could be affected by temporally biased precipitation, depending on the scale of the precipitation bias and the ability of the plant to compensate or mitigate growth inhibition due to a water deficit. Precipitation deficits later in the growing period may be more detrimental to plant growth and can reduce plant responses to an increasing N deposition.

Australia's Bond Home Bias

OpenAIRE

Anil V. Mishra; Umaru B. Conteh

2014-01-01

This paper constructs the float adjusted measure of home bias and explores the determinants of bond home bias by employing the International Monetary Fund's high quality dataset (2001 to 2009) on cross-border bond investment. The paper finds that Australian investors' prefer investing in countries with higher economic development and more developed bond markets. Exchange rate volatility appears to be an impediment for cross-border bond investment. Investors prefer investing in countries with ...

The positivity bias in aging: Motivation or degradation?

Science.gov (United States)

Kalenzaga, Sandrine; Lamidey, Virginie; Ergis, Anne-Marie; Clarys, David; Piolino, Pascale

2016-08-01

The question of an emotional memory enhancement in aging, and of a positivity bias in particular, has been the subject of numerous empirical studies in the last decade. However, the roots of such positive preference are not yet well established. Partisans of a motivation-based perspective contend with those arguing that positivity is related to a cognitive or neural degradation. The aim of this study was to introduce some elements concerning positivity effect in aging. We compared immediate (i.e., immediate recall) versus delayed (i.e., delayed recall and recognition) emotional memory performance in 38 young adults, 39 old adults, 37 very old adults, and 41 Alzheimer's disease patients. Moreover, we manipulated the encoding instruction: Either participants received no particular processing instruction, or they had to process the material in a semantic way. The results indicated that the positivity bias is most likely to occur in individuals whose cognitive functions are preserved, after long retention delay, and in experimental conditions that do not constrain encoding. We concluded by highlighting that although these findings seem to be better in line with the motivation, rather than the degradation, perspective, they do not fully support either theory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Thermophysical Property Estimation by Transient Experiments: The Effect of a Biased Initial Temperature Distribution

Directory of Open Access Journals (Sweden)

Federico Scarpa

2015-01-01

Full Text Available The identification of thermophysical properties of materials in dynamic experiments can be conveniently performed by the inverse solution of the associated heat conduction problem (IHCP. The inverse technique demands the knowledge of the initial temperature distribution within the material. As only a limited number of temperature sensors (or no sensor at all are arranged inside the test specimen, the knowledge of the initial temperature distribution is affected by some uncertainty. This uncertainty, together with other possible sources of bias in the experimental procedure, will propagate in the estimation process and the accuracy of the reconstructed thermophysical property values could deteriorate. In this work the effect on the estimated thermophysical properties due to errors in the initial temperature distribution is investigated along with a practical method to quantify this effect. Furthermore, a technique for compensating this kind of bias is proposed. The method consists in including the initial temperature distribution among the unknown functions to be estimated. In this way the effect of the initial bias is removed and the accuracy of the identified thermophysical property values is highly improved.

Systematic biases in human heading estimation.

Directory of Open Access Journals (Sweden)

Luigi F Cuturi

Full Text Available Heading estimation is vital to everyday navigation and locomotion. Despite extensive behavioral and physiological research on both visual and vestibular heading estimation over more than two decades, the accuracy of heading estimation has not yet been systematically evaluated. Therefore human visual and vestibular heading estimation was assessed in the horizontal plane using a motion platform and stereo visual display. Heading angle was overestimated during forward movements and underestimated during backward movements in response to both visual and vestibular stimuli, indicating an overall multimodal bias toward lateral directions. Lateral biases are consistent with the overrepresentation of lateral preferred directions observed in neural populations that carry visual and vestibular heading information, including MSTd and otolith afferent populations. Due to this overrepresentation, population vector decoding yields patterns of bias remarkably similar to those observed behaviorally. Lateral biases are inconsistent with standard bayesian accounts which predict that estimates should be biased toward the most common straight forward heading direction. Nevertheless, lateral biases may be functionally relevant. They effectively constitute a perceptual scale expansion around straight ahead which could allow for more precise estimation and provide a high gain feedback signal to facilitate maintenance of straight-forward heading during everyday navigation and locomotion.

The Accuracy Enhancing Effect of Biasing Cues

NARCIS (Netherlands)

W. Vanhouche (Wouter); S.M.J. van Osselaer (Stijn)

2009-01-01

textabstractExtrinsic cues such as price and irrelevant attributes have been shown to bias consumers’ product judgments. Results in this article replicate those findings in pretrial judgments but show that such biasing cues can improve quality judgments at a later point in time. Initially biasing

Mixotrophic phytoflagellate bacterivory field measurements strongly biased by standard approaches

DEFF Research Database (Denmark)

Anderson, Ruth; Jürgens, Klaus; Hansen, Per Juel

2017-01-01

Bacterivory among small (≤ 20 μm) phytoflagellates (SP) is increasingly recognized as a globally relevant phenomenon, impacting a wide range of aspects from primary production levels to marine fisheries. However, to correctly parametrize mixotrophic SP in biogeochemical and food web models, a bet...... mixotrophic SP. Overall, this case study indicates that applying the two commonly used premises outlined above can introduce significant biases and considerably alter our perception of mixotrophy in a given system......., a better understanding of the magnitude and regulation of in situ SP feeding is urgently needed. Current methods to determine SP bacterivory in the field may introduce biases by treating these organisms as equivalent to heterotrophic nanoflagellates (HNF). In the present case study we experimentally tested...... two generally employed assumptions of such studies: (A) bacterivory rates of the whole SP community and of distinct SP groups remain constant over `short´ time scales (hours to a day) and (B) SP community ingestion rates approximate the average ingestion rate of all feeding individuals. Food vacuole...

Dressings and topical agents for preventing pressure ulcers.

Science.gov (United States)

Moore, Zena E H; Webster, Joan

2013-08-18

Pressure ulcers, which are localised injury to the skin, or underlying tissue or both, occur when people are unable to reposition themselves to relieve pressure on bony prominences. Pressure ulcers are often difficult to heal, painful and impact negatively on the individual's quality of life. The cost implications of pressure ulcer treatment are considerable, compounding the challenges in providing cost effective, efficient health services. Efforts to prevent the development of pressure ulcers have focused on nutritional support, pressure redistributing devices, turning regimes and the application of various topical agents and dressings designed to maintain healthy skin, relieve pressure and prevent shearing forces. Although products aimed at preventing pressure ulcers are widely used, it remains unclear which, if any, of these approaches are effective in preventing the development of pressure ulcers. To evaluate the effects of dressings and topical agents on the prevention of pressure ulcers, in people of any age without existing pressure ulcers, but considered to be at risk of developing a pressure ulcer, in any healthcare setting. In February 2013 we searched the following electronic databases to identify reports of relevant randomised clinical trials (RCTs): the Cochrane Wounds Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Database of Abstracts of Reviews of Effects (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We included RCTs evaluating the use of dressings, topical agents, or topical agents with dressings, compared with a different dressing, topical agent, or combined topical agent and dressing, or no intervention or standard care, with the aim of preventing the development of a pressure ulcer. We assessed trials for their appropriateness for inclusion and for their risk of bias. This was done by two review

How we categorize objects is related to how we remember them: The shape bias as a memory bias

Science.gov (United States)

Vlach, Haley A.

2016-01-01

The “shape bias” describes the phenomenon that, after a certain point in development, children and adults generalize object categories based upon shape to a greater degree than other perceptual features. The focus of research on the shape bias has been to examine the types of information that learners attend to in one moment in time. The current work takes a different approach by examining whether learners' categorical biases are related to their retention of information across time. In three experiments, children's (N = 72) and adults' (N = 240) memory performance for features of objects was examined in relation to their categorical biases. The results of these experiments demonstrated that the number of shape matches chosen during the shape bias task significantly predicted shape memory. Moreover, children and adults with a shape bias were more likely to remember the shape of objects than they were the color and size of objects. Taken together, this work suggests the development of a shape bias may engender better memory for shape information. PMID:27454236

Positioning of Weight Bias: Moving towards Social Justice.

Science.gov (United States)

Nutter, Sarah; Russell-Mayhew, Shelly; Alberga, Angela S; Arthur, Nancy; Kassan, Anusha; Lund, Darren E; Sesma-Vazquez, Monica; Williams, Emily

2016-01-01

Weight bias is a form of stigma with detrimental effects on the health and wellness of individuals with large bodies. Researchers from various disciplines have recognized weight bias as an important topic for public health and for professional practice. To date, researchers from various areas have approached weight bias from independent perspectives and from differing theoretical orientations. In this paper, we examined the similarities and differences between three perspectives (i.e., weight-centric, non-weight-centric (health-centric), and health at every size) used to understand weight bias and approach weight bias research with regard to (a) language about people with large bodies, (b) theoretical position, (c) identified consequences of weight bias, and (d) identified influences on weight-based social inequity. We suggest that, despite differences, each perspective acknowledges the negative influences that position weight as being within individual control and the negative consequences of weight bias. We call for recognition and discussion of weight bias as a social justice issue in order to change the discourse and professional practices extended towards individuals with large bodies. We advocate for an emphasis on social justice as a uniting framework for interdisciplinary research on weight bias.

An inclusive taxonomy of behavioral biases

OpenAIRE

David Peón; Manel Antelo; Anxo Calvo-Silvosa

2017-01-01

This paper overviews the theoretical and empirical research on behavioral biases and their influence in the literature. To provide a systematic exposition, we present a unified framework that takes the reader through an original taxonomy, based on the reviews of relevant authors in the field. In particular, we establish three broad categories that may be distinguished: heuristics and biases; choices, values and frames; and social factors. We then describe the main biases within each category,...

“Virtual IED sensor” at an rf-biased electrode in low-pressure plasma

Energy Technology Data Exchange (ETDEWEB)

Bogdanova, M. A.; Zyryanov, S. M. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, SINP MSU, Moscow (Russian Federation); Faculty of Physics, Moscow State University, MSU, Moscow (Russian Federation); Lopaev, D. V.; Rakhimov, A. T. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, SINP MSU, Moscow (Russian Federation)

2016-07-15

Energy distribution and the flux of the ions coming on a surface are considered as the key-parameters in anisotropic plasma etching. Since direct ion energy distribution (IED) measurements at the treated surface during plasma processing are often hardly possible, there is an opportunity for virtual ones. This work is devoted to the possibility of such indirect IED and ion flux measurements at an rf-biased electrode in low-pressure rf plasma by using a “virtual IED sensor” which represents “in-situ” IED calculations on the absolute scale in accordance with a plasma sheath model containing a set of measurable external parameters. The “virtual IED sensor” should also involve some external calibration procedure. Applicability and accuracy of the “virtual IED sensor” are validated for a dual-frequency reactive ion etching (RIE) inductively coupled plasma (ICP) reactor with a capacitively coupled rf-biased electrode. The validation is carried out for heavy (Ar) and light (H{sub 2}) gases under different discharge conditions (different ICP powers, rf-bias frequencies, and voltages). An EQP mass-spectrometer and an rf-compensated Langmuir probe (LP) are used to characterize plasma, while an rf-compensated retarded field energy analyzer (RFEA) is applied to measure IED and ion flux at the rf-biased electrode. Besides, the pulsed selfbias method is used as an external calibration procedure for ion flux estimating at the rf-biased electrode. It is shown that pulsed selfbias method allows calibrating the IED absolute scale quite accurately. It is also shown that the “virtual IED sensor” based on the simplest collisionless sheath model allows reproducing well enough the experimental IEDs at the pressures when the sheath thickness s is less than the ion mean free path λ{sub i} (s < λ{sub i}). At higher pressure (when s > λ{sub i}), the difference between calculated and experimental IEDs due to ion collisions in the sheath is observed in the low

Effect and reporting bias of RhoA/ROCK-blockade intervention on locomotor recovery after spinal cord injury: a systematic review and meta-analysis.

Science.gov (United States)

Watzlawick, Ralf; Sena, Emily S; Dirnagl, Ulrich; Brommer, Benedikt; Kopp, Marcel A; Macleod, Malcolm R; Howells, David W; Schwab, Jan M

2014-01-01

Blockade of small GTPase-RhoA signaling pathway is considered a candidate translational strategy to improve functional outcome after spinal cord injury (SCI) in humans. Pooling preclinical evidence by orthodox meta-analysis is confounded by missing data (publication bias). To conduct a systematic review and meta-analysis of RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) blocking approaches to (1) analyze the impact of bias that may lead to inflated effect sizes and (2) determine the normalized effect size of functional locomotor recovery after experimental thoracic SCI. We conducted a systematic search of PubMed, EMBASE, and Web of Science and hand searched related references. Studies were selected if they reported the effect of RhoA/ROCK inhibitors (C3-exoenzmye, fasudil, Y-27632, ibuprofen, siRhoA, and p21) in experimental spinal cord hemisection, contusion, or transection on locomotor recovery measured by the Basso, Beattie, and Bresnahan score or the Basso Mouse Scale for Locomotion. Two investigators independently assessed the identified studies. Details of individual study characteristics from each publication were extracted and effect sizes pooled using a random effects model. We assessed risk for bias using a 9-point-item quality checklist and calculated publication bias with Egger regression and the trim and fill method. A stratified meta-analysis was used to assess the impact of study characteristics on locomotor recovery. Thirty studies (725 animals) were identified. RhoA/ROCK inhibition was found to improve locomotor outcome by 21% (95% CI, 16.0-26.6). Assessment of publication bias by the trim and fill method suggested that 30% of experiments remain unpublished. Inclusion of these theoretical missing studies suggested a 27% overestimation of efficacy, reducing the overall efficacy to a 15% improvement in locomotor recovery. Low study quality was associated with larger estimates of neurobehavioral outcome. Taking into account

Cognitive biases can affect moral intuitions about cognitive enhancement

Directory of Open Access Journals (Sweden)

Lucius eCaviola

2014-10-01

Full Text Available Research into cognitive biases that impair human judgment has mostly been applied to the area of economic decision-making. Ethical decision-making has been comparatively neglected. Since ethical decisions often involve very high individual as well as collective stakes, analyzing how cognitive biases affect them can be expected to yield important results. In this theoretical article, we consider the ethical debate about cognitive enhancement (CE and suggest a number of cognitive biases that are likely to affect moral intuitions and judgments about CE: status quo bias, loss aversion, risk aversion, omission bias, scope insensitivity, nature bias, and optimistic bias. We find that there are more well-documented biases that are likely to cause irrational aversion to CE than biases in the opposite direction. This suggests that common attitudes about CE are predominantly negatively biased. Within this new perspective, we hope that subsequent research will be able to elaborate this hypothesis and develop effective de-biasing techniques that can help increase the rationality of the public CE debate and thus improve our ethical decision-making.

Transition of poloidal viscosity by electrode biasing in the Large Helical Device

International Nuclear Information System (INIS)

Kitajima, S.; Ishii, K.; Takahashi, H.

2012-11-01

Electrode biasing experiments were tried in various magnetic configurations on the Large Helical Device (LHD). The transitions of poloidal viscosity, which were accompanied with bifurcation phenomena characterized by a negative resistance, were clearly observed on LHD by the electrode biasing. The critical external driving force required for transition were compared with the local maximum in ion viscosity, and the radial resistivity before the transition also compared with the expected value from a neoclassical theory. The critical driving force increased and the radial resistivity decreased with the major radius of the magnetic axis R ax going outward. The configuration dependence of the transition condition and the radial resistivity qualitatively agreed with neoclassical theories. The radial electric field and the viscosity were also evaluated by the neoclassical transport code for a non-axisymmetric system, and estimated electrode voltage required for the transition, which was consistent with the experimental results. (author)

Determination and Correction of Persistent Biases in Quantum Annealers

Science.gov (United States)

2016-08-25

for all of the qubits. Narrowing of the bias distribution. To show the correctability of the persistent biases , we ran the experiment described above...this is a promising application for bias correction . Importantly, while the J biases determined here are in general smaller than the h biases , numerical...1Scientific RepoRts | 6:18628 | DOI: 10.1038/srep18628 www.nature.com/scientificreports Determination and correction of persistent biases in quantum

Does neurocognitive function affect cognitive bias toward an emotional stimulus? Association between general attentional ability and attentional bias toward threat

OpenAIRE

Hakamata, Yuko; Matsui, Mie; Tagaya, Hirokuni

2014-01-01

Background: Although poorer cognitive performance has been found to be associated with anxiety, it remains unclear whether neurocognitive function affects biased cognitive processing toward emotional information. We investigated whether general cognitive function evaluated with a standard neuropsychological test predicts biased cognition, focusing on attentional bias toward threat. Methods: One hundred and five healthy young adults completed a dot-probe task measuring attentional bias and ...

Approach-Induced Biases in Human Information Sampling.

Directory of Open Access Journals (Sweden)

Laurence T Hunt

2016-11-01

Full Text Available Information sampling is often biased towards seeking evidence that confirms one's prior beliefs. Despite such biases being a pervasive feature of human behavior, their underlying causes remain unclear. Many accounts of these biases appeal to limitations of human hypothesis testing and cognition, de facto evoking notions of bounded rationality, but neglect more basic aspects of behavioral control. Here, we investigated a potential role for Pavlovian approach in biasing which information humans will choose to sample. We collected a large novel dataset from 32,445 human subjects, making over 3 million decisions, who played a gambling task designed to measure the latent causes and extent of information-sampling biases. We identified three novel approach-related biases, formalized by comparing subject behavior to a dynamic programming model of optimal information gathering. These biases reflected the amount of information sampled ("positive evidence approach", the selection of which information to sample ("sampling the favorite", and the interaction between information sampling and subsequent choices ("rejecting unsampled options". The prevalence of all three biases was related to a Pavlovian approach-avoid parameter quantified within an entirely independent economic decision task. Our large dataset also revealed that individual differences in the amount of information gathered are a stable trait across multiple gameplays and can be related to demographic measures, including age and educational attainment. As well as revealing limitations in cognitive processing, our findings suggest information sampling biases reflect the expression of primitive, yet potentially ecologically adaptive, behavioral repertoires. One such behavior is sampling from options that will eventually be chosen, even when other sources of information are more pertinent for guiding future action.

Critical bias fields for tilting stability in the BETA-II experiment

International Nuclear Information System (INIS)

Dalhed, H.E.

1981-01-01

The PEST equilibrium code and the GATO ideal MHD stability code have been modified to study stability properties of Spheromak configurations. Of particular interest is the effect on tilting modes of perfectly conducting walls which do not link the plasma. This paper makes use of equilibria and conducting walls specifically designed to model the BETA-II experiment at LLNL. Onset of the tilting mode is determined as a function of the bias magnetic field. Comparison with available experimental data shows promising agreement with the numerical results

Gender bias affects forests worldwide

Science.gov (United States)

Marlène Elias; Susan S Hummel; Bimbika S Basnett; Carol J.P. Colfer

2017-01-01

Gender biases persist in forestry research and practice. These biases result in reduced scientific rigor and inequitable, ineffective, and less efficient policies, programs, and interventions. Drawing from a two-volume collection of current and classic analyses on gender in forests, we outline five persistent and inter-related themes: gendered governance, tree tenure,...

Overcoming the barrier of narrative adherence in conflicts through awareness of the psychological bias of naïve realism.

Science.gov (United States)

Nasie, Meytal; Bar-Tal, Daniel; Pliskin, Ruthie; Nahhas, Eman; Halperin, Eran

2014-11-01

One significant socio-psychological barrier for peaceful resolution of conflicts is each party's adherence to its own collective narrative. We hypothesized that raising awareness to the psychological bias of naïve realism and its identification in oneself would provide a path to overcoming this barrier, thus increasing openness to the adversary's narrative. We conducted three experimental studies in the context of the Israeli-Palestinian conflict. Studies 1 and 2, conducted among Jewish Israelis and Palestinian Israelis, respectively, revealed that participants with hawkish political ideology reported greater openness to the adversary's narrative when they were made aware of naïve realism bias. Study 3 revealed that hawkish participants at the baseline adhered to the ingroup narrative and resisted the adversary's narrative more than dovish participants. They were also more able to identify the bias in themselves upon learning about it. This identification may explain why the manipulation led to bias correction only among hawkish participants. © 2014 by the Society for Personality and Social Psychology, Inc.

Exploring the microscopic origin of exchange bias with photoelectron emission microscopy (invited)

International Nuclear Information System (INIS)

Scholl, A.; Nolting, F.; Stohr, J.; Regan, T.; Luning, J.; Seo, J. W.; Locquet, J.-P.; Fompeyrine, J.; Anders, S.; Ohldag, H.

2001-01-01

It is well known that magnetic exchange coupling across the ferromagnet - antiferromagnet interface results in an unidirectional magnetic anisotropy of the ferromagnetic layer, called exchange bias. Despite large experimental and theoretical efforts, the origin of exchange bias is still controversial, mainly because detection of the interfacial magnetic structure is difficult. We have applied photoelectron emission microscopy (PEEM) on several ferromagnet - antiferromagnet thin-film structures and microscopically imaged the ferromagnetic and the antiferromagnetic structure with high spatial resolution. Taking advantage of the surface sensitivity and elemental specificity of PEEM, the magnetic configuration and critical properties such as the Neel temperature were determined on LaFeO 3 and NiO thin films and single crystals. On samples coated with a ferromagnetic layer, we microscopically observe exchange coupling across the interface, causing a clear correspondence of the domain structures in the adjacent ferromagnet and antiferromagnet. Field dependent measurements reveal a strong uniaxial anisotropy in individual ferromagnetic domains. A local exchange bias was observed even in not explicitly field-annealed samples, caused by interfacial uncompensated magnetic spins. These experiments provide highly desired information on the relative orientation of electron spins at the interface between ferromagnets and antiferromagnets. [copyright] 2001 American Institute of Physics

Weight bias internalization across weight categories among school-aged children. Validation of the Weight Bias Internalization Scale for Children.

Science.gov (United States)

Zuba, Anna; Warschburger, Petra

2018-06-01

Anti-fat bias is widespread and is linked to the internalization of weight bias and psychosocial problems. The purpose of this study was to examine the internalization of weight bias among children across weight categories and to evaluate the psychometric properties of the Weight Bias Internalization Scale for Children (WBIS-C). Data were collected from 1484 primary school children and their parents. WBIS-C demonstrated good internal consistency (α = .86) after exclusion of Item 1. The unitary factor structure was supported using exploratory and confirmatory factor analyses (factorial validity). Girls and overweight children reported higher WBIS-C scores in comparison to boys and non-overweight peers (known-groups validity). Convergent validity was shown by significant correlations with psychosocial problems. Internalization of weight bias explained additional variance in different indicators of psychosocial well-being. The results suggest that the WBIS-C is a psychometrically sound and informative tool to assess weight bias internalization among children. Copyright © 2018 Elsevier Ltd. All rights reserved.

Contamination effects on fixed-bias Langmuir probes

Energy Technology Data Exchange (ETDEWEB)

Steigies, C. T. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, 24098 Kiel (Germany); Barjatya, A. [Department of Physical Sciences, Embry-Riddle Aeronautical University, Daytona Beach, Florida 32114 (United States)

2012-11-15

Langmuir probes are standard instruments for plasma density measurements on many sounding rockets. These probes can be operated in swept-bias as well as in fixed-bias modes. In swept-bias Langmuir probes, contamination effects are frequently visible as a hysteresis between consecutive up and down voltage ramps. This hysteresis, if not corrected, leads to poorly determined plasma densities and temperatures. With a properly chosen sweep function, the contamination parameters can be determined from the measurements and correct plasma parameters can then be determined. In this paper, we study the contamination effects on fixed-bias Langmuir probes, where no hysteresis type effect is seen in the data. Even though the contamination is not evident from the measurements, it does affect the plasma density fluctuation spectrum as measured by the fixed-bias Langmuir probe. We model the contamination as a simple resistor-capacitor circuit between the probe surface and the plasma. We find that measurements of small scale plasma fluctuations (meter to sub-meter scale) along a rocket trajectory are not affected, but the measured amplitude of large scale plasma density variation (tens of meters or larger) is attenuated. From the model calculations, we determine amplitude and cross-over frequency of the contamination effect on fixed-bias probes for different contamination parameters. The model results also show that a fixed bias probe operating in the ion-saturation region is affected less by contamination as compared to a fixed bias probe operating in the electron saturation region.

Empirical evidence of bias in the design of experimental stroke studies - A metaepidemiologic approach

NARCIS (Netherlands)

Crossley, Nicolas A.; Sena, Emily; Goehler, Jos; Horn, Jannekke; van der Worp, Bart; Bath, Philip M. W.; Macleod, Malcolm; Dirnagl, Ulrich

2008-01-01

Background and Purpose - At least part of the failure in the transition from experimental to clinical studies in stroke has been attributed to the imprecision introduced by problems in the design of experimental stroke studies. Using a metaepidemiologic approach, we addressed the effect of

Giant exchange bias and its angular dependence in Co/CoO core-shell nanowire assemblies

Energy Technology Data Exchange (ETDEWEB)

Gandha, Kinjal; Chaudhary, Rakesh P.; Mohapatra, Jeotikanta; Koymen, Ali R.; Liu, J. Ping, E-mail: pliu@uta.edu

2017-07-12

The exchange-bias field (H{sub EB}) and its angular dependence are systematically investigated in Co/CoO core-shell nanowire assemblies (∼15 nm in diameter and ∼200 nm in length) consisting of single-crystalline Co core and polycrystalline CoO shell. Giant exchange-bias field (H{sub EB}) up to 2.4 kOe is observed below a blocking temperature (T{sub EB} ∼150 K) in the aligned Co/CoO nanowire assemblies. It is also found that there is an angular dependence between the H{sub EB} and the applied magnetization direction. The H{sub EB} showed a peak at 30° between the applied field and the nanowire aligned direction, which may be attributed to the noncollinear spin orientations at the interface between the ferromagnetic core and the antiferromagnetic shell. This behavior is quantitatively supported by an analytical calculation based on Stoner–Wohlfarth model. This study underlines the importance of the competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. - Highlights: • Giant exchange bias is observed in oriented Co/CoO core-shell nanowire assemblies. • Study of angular and temperature dependence of the exchange bias effect. • Competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. • Effect of misaligned spins in FM/AFM interface on angular dependence of exchange bias. • We explain the analytical model that accounts for experimental results.

Giant exchange bias and its angular dependence in Co/CoO core-shell nanowire assemblies

International Nuclear Information System (INIS)

Gandha, Kinjal; Chaudhary, Rakesh P.; Mohapatra, Jeotikanta; Koymen, Ali R.; Liu, J. Ping

2017-01-01

The exchange-bias field (H EB ) and its angular dependence are systematically investigated in Co/CoO core-shell nanowire assemblies (∼15 nm in diameter and ∼200 nm in length) consisting of single-crystalline Co core and polycrystalline CoO shell. Giant exchange-bias field (H EB ) up to 2.4 kOe is observed below a blocking temperature (T EB ∼150 K) in the aligned Co/CoO nanowire assemblies. It is also found that there is an angular dependence between the H EB and the applied magnetization direction. The H EB showed a peak at 30° between the applied field and the nanowire aligned direction, which may be attributed to the noncollinear spin orientations at the interface between the ferromagnetic core and the antiferromagnetic shell. This behavior is quantitatively supported by an analytical calculation based on Stoner–Wohlfarth model. This study underlines the importance of the competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. - Highlights: • Giant exchange bias is observed in oriented Co/CoO core-shell nanowire assemblies. • Study of angular and temperature dependence of the exchange bias effect. • Competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. • Effect of misaligned spins in FM/AFM interface on angular dependence of exchange bias. • We explain the analytical model that accounts for experimental results.

Estimation of Received Signal Strength Distribution for Smart Meters with Biased Measurement Data Set

DEFF Research Database (Denmark)

Kielgast, Mathias Rønholt; Rasmussen, Anders Charly; Laursen, Mathias Hjorth

2017-01-01

This letter presents an experimental study and a novel modelling approach of the wireless channel of smart utility meters placed in basements or sculleries. The experimental data consist of signal strength measurements of consumption report packets. Since such packets are only registered if they ......This letter presents an experimental study and a novel modelling approach of the wireless channel of smart utility meters placed in basements or sculleries. The experimental data consist of signal strength measurements of consumption report packets. Since such packets are only registered...... if they can be decoded by the receiver, the part of the signal strength distribution that falls below the receiver sensitivity threshold is not observable. We combine a Rician fading model with a bias function that captures the cut-off in the observed signal strength measurements. Two sets of experimental...... data are analysed. It is shown that the proposed method offers an approximation of the distribution of the signal strength measurements that is better than a naïve Rician fitting....

Experimental Quantum-Walk Revival with a Time-Dependent Coin

Science.gov (United States)

Xue, P.; Zhang, R.; Qin, H.; Zhan, X.; Bian, Z. H.; Li, J.; Sanders, Barry C.

2015-04-01

We demonstrate a quantum walk with time-dependent coin bias. With this technique we realize an experimental single-photon one-dimensional quantum walk with a linearly ramped time-dependent coin flip operation and thereby demonstrate two periodic revivals of the walker distribution. In our beam-displacer interferometer, the walk corresponds to movement between discretely separated transverse modes of the field serving as lattice sites, and the time-dependent coin flip is effected by implementing a different angle between the optical axis of half-wave plate and the light propagation at each step. Each of the quantum-walk steps required to realize a revival comprises two sequential orthogonal coin-flip operators, with one coin having constant bias and the other coin having a time-dependent ramped coin bias, followed by a conditional translation of the walker.

Approach-bias predicts development of cannabis problem severity in heavy cannabis users: results from a prospective FMRI study.

Directory of Open Access Journals (Sweden)

Janna Cousijn

Full Text Available A potentially powerful predictor for the course of drug (abuse is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI, neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment.

Approach-bias predicts development of cannabis problem severity in heavy cannabis users: results from a prospective FMRI study.

Science.gov (United States)

Cousijn, Janna; Goudriaan, Anna E; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Wiers, Reinout W

2012-01-01

A potentially powerful predictor for the course of drug (ab)use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI), neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC) and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment.

Heuristic Biases in Mathematical Reasoning

Science.gov (United States)

Inglis, Matthew; Simpson, Adrian

2005-01-01

In this paper we briefly describe the dual process account of reasoning, and explain the role of heuristic biases in human thought. Concentrating on the so-called matching bias effect, we describe a piece of research that indicates a correlation between success at advanced level mathematics and an ability to override innate and misleading…

Quantum state engineering with flux-biased Josephson phase qubits by rapid adiabatic passages

International Nuclear Information System (INIS)

Nie, W.; Huang, J. S.; Shi, X.; Wei, L. F.

2010-01-01

In this article, the scheme of quantum computing based on the Stark-chirped rapid adiabatic passage (SCRAP) technique [L. F. Wei, J. R. Johansson, L. X. Cen, S. Ashhab, and F. Nori, Phys. Rev. Lett. 100, 113601 (2008)] is extensively applied to implement quantum state manipulations in flux-biased Josephson phase qubits. The broken-parity symmetries of bound states in flux-biased Josephson junctions are utilized to conveniently generate the desirable Stark shifts. Then, assisted by various transition pulses, universal quantum logic gates as well as arbitrary quantum state preparations can be implemented. Compared with the usual π-pulse operations widely used in experiments, the adiabatic population passages proposed here are insensitive to the details of the applied pulses and thus the desirable population transfers can be satisfyingly implemented. The experimental feasibility of the proposal is also discussed.

Improved Correction of Misclassification Bias With Bootstrap Imputation.

Science.gov (United States)

van Walraven, Carl

2018-07-01

Diagnostic codes used in administrative database research can create bias due to misclassification. Quantitative bias analysis (QBA) can correct for this bias, requires only code sensitivity and specificity, but may return invalid results. Bootstrap imputation (BI) can also address misclassification bias but traditionally requires multivariate models to accurately estimate disease probability. This study compared misclassification bias correction using QBA and BI. Serum creatinine measures were used to determine severe renal failure status in 100,000 hospitalized patients. Prevalence of severe renal failure in 86 patient strata and its association with 43 covariates was determined and compared with results in which renal failure status was determined using diagnostic codes (sensitivity 71.3%, specificity 96.2%). Differences in results (misclassification bias) were then corrected with QBA or BI (using progressively more complex methods to estimate disease probability). In total, 7.4% of patients had severe renal failure. Imputing disease status with diagnostic codes exaggerated prevalence estimates [median relative change (range), 16.6% (0.8%-74.5%)] and its association with covariates [median (range) exponentiated absolute parameter estimate difference, 1.16 (1.01-2.04)]. QBA produced invalid results 9.3% of the time and increased bias in estimates of both disease prevalence and covariate associations. BI decreased misclassification bias with increasingly accurate disease probability estimates. QBA can produce invalid results and increase misclassification bias. BI avoids invalid results and can importantly decrease misclassification bias when accurate disease probability estimates are used.

An improved, bias-reduced probabilistic functional gene network of baker's yeast, Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Insuk Lee

2007-10-01

Full Text Available Probabilistic functional gene networks are powerful theoretical frameworks for integrating heterogeneous functional genomics and proteomics data into objective models of cellular systems. Such networks provide syntheses of millions of discrete experimental observations, spanning DNA microarray experiments, physical protein interactions, genetic interactions, and comparative genomics; the resulting networks can then be easily applied to generate testable hypotheses regarding specific gene functions and associations.We report a significantly improved version (v. 2 of a probabilistic functional gene network of the baker's yeast, Saccharomyces cerevisiae. We describe our optimization methods and illustrate their effects in three major areas: the reduction of functional bias in network training reference sets, the application of a probabilistic model for calculating confidences in pair-wise protein physical or genetic interactions, and the introduction of simple thresholds that eliminate many false positive mRNA co-expression relationships. Using the network, we predict and experimentally verify the function of the yeast RNA binding protein Puf6 in 60S ribosomal subunit biogenesis.YeastNet v. 2, constructed using these optimizations together with additional data, shows significant reduction in bias and improvements in precision and recall, in total covering 102,803 linkages among 5,483 yeast proteins (95% of the validated proteome. YeastNet is available from http://www.yeastnet.org.

Affective Biases in Humans and Animals.

Science.gov (United States)

Robinson, E S J; Roiser, J P

Depression is one of the most common but poorly understood psychiatric conditions. Although drug treatments and psychological therapies are effective in some patients, many do not achieve full remission and some patients receive no apparent benefit. Developing new improved treatments requires a better understanding of the aetiology of symptoms and evaluation of novel therapeutic targets in pre-clinical studies. Recent developments in our understanding of the basic cognitive processes that may contribute to the development of depression and its treatment offer new opportunities for both clinical and pre-clinical research. This chapter discusses the clinical evidence supporting a cognitive neuropsychological model of depression and antidepressant efficacy, and how this information may be usefully translated to pre-clinical investigation. Studies using neuropsychological tests in depressed patients and at risk populations have revealed basic negative emotional biases and disrupted reward and punishment processing, which may also impact on non-affective cognition. These affective biases are sensitive to antidepressant treatments with early onset effects observed, suggesting an important role in recovery. This clinical work into affective biases has also facilitated back-translation to animals and the development of assays to study affective biases in rodents. These animal studies suggest that, similar to humans, rodents in putative negative affective states exhibit negative affective biases on decision-making and memory tasks. Antidepressant treatments also induce positive biases in these rodent tasks, supporting the translational validity of this approach. Although still in the early stages of development and validation, affective biases in depression have the potential to offer new insights into the clinical condition, as well as facilitating the development of more translational approaches for pre-clinical studies.

Biased managers, organizational design, and incentive provision

OpenAIRE

Moreira, Humberto Ataíde; Costa, Cristiano Machado; Ferreira, Daniel Bernardo Soares

2004-01-01

Rio de Janeiro We model the tradeoff between the balance and the strength of incentives implicit in the choice between hierarchical and matrix organizational structures. We show that managerial biases determine which structure is optimal: hierarchical forms are preferred when biases are low, while matrix structures are preferred when biases are high.

Toxicology research for precautionary decision-making and the role of Human & Experimental Toxicology.

Science.gov (United States)

Grandjean, P

2015-12-01

A key aim of toxicology is the prevention of adverse effects due to toxic hazards. Therefore, the dissemination of toxicology research findings must confront two important challenges: one being the lack of information on the vast majority of potentially toxic industrial chemicals and the other being the strict criteria for scientific proof usually required for decision-making in regard to prevention. The present study ascertains the coverage of environmental chemicals in four volumes of Human & Experimental Toxicology and the presentation and interpretation of research findings in published articles. Links in SciFinder showed that the 530 articles published in four selected volumes between 1984 and 2014 primarily dealt with metals (126 links) and other toxicants that have received substantial attention in the past. Thirteen compounds identified by US authorities in 2006 as high-priority substances, for which toxicology documentation is badly needed, were not covered in the journal issues at all. When reviewing published articles, reliance on p values was standard, and non-significant findings were often called 'negative.' This tradition may contribute to the perceived need to extend existing research on toxic hazards that have already been well characterized. Several sources of bias towards the null hypothesis can affect toxicology research, but are generally not considered, thus adding to the current inclination to avoid false positive findings. In this regard, toxicology is particularly prone to bias because of the known paucity of false positives and, in particular, the existence of a vast number of toxic hazards which by default are considered innocuous due to lack of documentation. The Precautionary Principle could inspire decision-making on the basis of incomplete documentation and should stimulate a change in toxicology traditions and in toxicology research publication. © The Author(s) 2015.

Understanding and Overcoming Implicit Gender Bias in Plastic Surgery.

Science.gov (United States)

Phillips, Nicole A; Tannan, Shruti C; Kalliainen, Loree K

2016-11-01

Although explicit sex-based discrimination has largely been deemed unacceptable in professional settings, implicit gender bias persists and results in a significant lack of parity in plastic surgery and beyond. Implicit gender bias is the result of a complex interplay of cultural and societal expectations, learned behaviors, and standardized associations. As such, both male and female surgeons are subject to its influence. A review of the literature was conducted, examining theories of gender bias, current manifestations of gender bias in plastic surgery and other fields, and interventions designed to address gender bias. Multiple studies demonstrate persistent gender bias that impacts female physicians at all levels of training. Several institutions have enacted successful interventions to identify and address gender bias. Explicit gender bias has largely disappeared, yet unconscious or implicit gender bias persists. A wide-scale commitment to addressing implicit gender bias in plastic surgery is necessary and overdue. Recommendations include immediate actions that can be undertaken on an individual basis, and changes that should be implemented at a national and international level by leaders in the field.

Galaxy bias and primordial non-Gaussianity

Energy Technology Data Exchange (ETDEWEB)

Assassi, Valentin; Baumann, Daniel [DAMTP, Cambridge University, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Schmidt, Fabian, E-mail: assassi@ias.edu, E-mail: D.D.Baumann@uva.nl, E-mail: fabians@MPA-Garching.MPG.DE [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)

2015-12-01

We present a systematic study of galaxy biasing in the presence of primordial non-Gaussianity. For a large class of non-Gaussian initial conditions, we define a general bias expansion and prove that it is closed under renormalization, thereby showing that the basis of operators in the expansion is complete. We then study the effects of primordial non-Gaussianity on the statistics of galaxies. We show that the equivalence principle enforces a relation between the scale-dependent bias in the galaxy power spectrum and that in the dipolar part of the bispectrum. This provides a powerful consistency check to confirm the primordial origin of any observed scale-dependent bias. Finally, we also discuss the imprints of anisotropic non-Gaussianity as motivated by recent studies of higher-spin fields during inflation.

Galaxy bias and primordial non-Gaussianity

International Nuclear Information System (INIS)

Assassi, Valentin; Baumann, Daniel; Schmidt, Fabian

2015-01-01

We present a systematic study of galaxy biasing in the presence of primordial non-Gaussianity. For a large class of non-Gaussian initial conditions, we define a general bias expansion and prove that it is closed under renormalization, thereby showing that the basis of operators in the expansion is complete. We then study the effects of primordial non-Gaussianity on the statistics of galaxies. We show that the equivalence principle enforces a relation between the scale-dependent bias in the galaxy power spectrum and that in the dipolar part of the bispectrum. This provides a powerful consistency check to confirm the primordial origin of any observed scale-dependent bias. Finally, we also discuss the imprints of anisotropic non-Gaussianity as motivated by recent studies of higher-spin fields during inflation

Bias changing molecule–lead couple and inducing low bias negative differential resistance for electrons acceptor predicted by first-principles study

International Nuclear Information System (INIS)

Min, Y.; Fang, J.H.; Zhong, C.G.; Dong, Z.C.; Zhao, Z.Y.; Zhou, P.X.; Yao, K.L.

2015-01-01

A first-principles study of the transport properties of 3,13-dimercaptononacene–6,21-dione molecule sandwiched between two gold leads is reported. The strong effect of negative differential resistance with large peak-to-valley ratio of 710% is present under low bias. We found that bias can change molecule–lead couple and induce low bias negative differential resistance for electrons acceptor, which may promise the potential applications in molecular devices with low-power dissipation in the future. - Highlights: • Acceptor is constructed to negative differential resistor (NDR). • NDR effect is present under low bias. • Bias change molecule–lead couple and induce NDR effect

Mechanism for and method of biasing magnetic sensor

Science.gov (United States)

Kautz, David R.

2007-12-04

A magnetic sensor package having a biasing mechanism involving a coil-generated, resistor-controlled magnetic field for providing a desired biasing effect. In a preferred illustrated embodiment, the package broadly comprises a substrate; a magnetic sensor element; a biasing mechanism, including a coil and a first resistance element; an amplification mechanism; a filter capacitor element; and an encapsulant. The sensor is positioned within the coil. A current applied to the coil produces a biasing magnetic field. The biasing magnetic field is controlled by selecting a resistance value for the first resistance element which achieves the desired biasing effect. The first resistance element preferably includes a plurality of selectable resistors, the selection of one or more of which sets the resistance value.

Short paper: Experimental analysis of misbehavior detection and prevention in VANETs

NARCIS (Netherlands)

Bissmeyer, N.; Schroder, K.; Petit, Jonathan; Mauthofer, S.; Bayarou, K.

2013-01-01

Vehicular Ad-hoc Networks (VANETs) aim to increase, among others, traffic safety and efficiency by warning and informing the driver about road events and hazards. Due to their direct impact on drivers' safety, external and internal attacks have to be prevented. While authentication prevents most of

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias.

Science.gov (United States)

Russo, Riccardo; Whittuck, Dora; Roberson, Debi; Dutton, Kevin; Georgiou, George; Fox, Elaine

2006-05-01

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.

White and Black American Children’s Implicit Intergroup Bias

Science.gov (United States)

Newheiser, Anna-Kaisa; Olson, Kristina R.

2011-01-01

Despite a decline in explicit prejudice, adults and children from majority groups (e.g., White Americans) often express bias implicitly, as assessed by the Implicit Association Test. In contrast, minority-group (e.g., Black American) adults on average show no bias on the IAT. In the present research, representing the first empirical investigation of whether Black children’s IAT responses parallel those of Black adults, we examined implicit bias in 7–11-year-old White and Black American children. Replicating previous findings with adults, whereas White children showed a robust ingroup bias, Black children showed no bias. Additionally, we investigated the role of valuing status in the development of implicit bias. For Black children, explicit preference for high status predicted implicit outgroup bias: Black children who explicitly expressed high preference for rich (vs. poor) people showed an implicit preference for Whites comparable in magnitude to White children’s ingroup bias. Implications for research on intergroup bias are discussed. PMID:22184478

Removing Malmquist bias from linear regressions

Science.gov (United States)

Verter, Frances

1993-01-01

Malmquist bias is present in all astronomical surveys where sources are observed above an apparent brightness threshold. Those sources which can be detected at progressively larger distances are progressively more limited to the intrinsically luminous portion of the true distribution. This bias does not distort any of the measurements, but distorts the sample composition. We have developed the first treatment to correct for Malmquist bias in linear regressions of astronomical data. A demonstration of the corrected linear regression that is computed in four steps is presented.

Stimulus- and state-dependence of systematic bias in spatial attention: additive effects of stimulus-size and time-on-task.

Science.gov (United States)

Benwell, Christopher S Y; Harvey, Monika; Gardner, Stephanie; Thut, Gregor

2013-03-01

Systematic biases in spatial attention are a common finding. In the general population, a systematic leftward bias is typically observed (pseudoneglect), possibly as a consequence of right hemisphere dominance for visuospatial attention. However, this leftward bias can cross-over to a systematic rightward bias with changes in stimulus and state factors (such as line length and arousal). The processes governing these changes are still unknown. Here we tested models of spatial attention as to their ability to account for these effects. To this end, we experimentally manipulated both stimulus and state factors, while healthy participants performed a computerized version of a landmark task. State was manipulated by time-on-task (>1 h) leading to increased fatigue and a reliable left- to rightward shift in spatial bias. Stimulus was manipulated by presenting either long or short lines which was associated with a shift of subjective midpoint from a reliable leftward bias for long to a more rightward bias for short lines. Importantly, we found time-on-task and line length effects to be additive suggesting a common denominator for line bisection across all conditions, which is in disagreement with models that assume that bisection decisions in long and short lines are governed by distinct processes (Magnitude estimation vs Global/local distinction). Our findings emphasize the dynamic rather than static nature of spatial biases in midline judgement. They are best captured by theories of spatial attention positing that spatial bias is flexibly modulated, and subject to inter-hemispheric balance which can change over time or conditions to accommodate task demands or reflect fatigue. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ensuring transparency and minimization of methodologic bias in preclinical pain research: PPRECISE considerations.

Science.gov (United States)

Andrews, Nick A; Latrémolière, Alban; Basbaum, Allan I; Mogil, Jeffrey S; Porreca, Frank; Rice, Andrew S C; Woolf, Clifford J; Currie, Gillian L; Dworkin, Robert H; Eisenach, James C; Evans, Scott; Gewandter, Jennifer S; Gover, Tony D; Handwerker, Hermann; Huang, Wenlong; Iyengar, Smriti; Jensen, Mark P; Kennedy, Jeffrey D; Lee, Nancy; Levine, Jon; Lidster, Katie; Machin, Ian; McDermott, Michael P; McMahon, Stephen B; Price, Theodore J; Ross, Sarah E; Scherrer, Grégory; Seal, Rebecca P; Sena, Emily S; Silva, Elizabeth; Stone, Laura; Svensson, Camilla I; Turk, Dennis C; Whiteside, Garth

2016-04-01

There is growing concern about lack of scientific rigor and transparent reporting across many preclinical fields of biological research. Poor experimental design and lack of transparent reporting can result in conscious or unconscious experimental bias, producing results that are not replicable. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the U.S. Food and Drug Administration sponsored a consensus meeting of the Preclinical Pain Research Consortium for Investigating Safety and Efficacy (PPRECISE) Working Group. International participants from universities, funding agencies, government agencies, industry, and a patient advocacy organization attended. Reduction of publication bias, increasing the ability of others to faithfully repeat experimental methods, and increased transparency of data reporting were specifically discussed. Parameters deemed essential to increase confidence in the published literature were clear, specific reporting of an a priori hypothesis and definition of primary outcome measure. Power calculations and whether measurement of minimal meaningful effect size to determine these should be a core component of the preclinical research effort provoked considerable discussion, with many but not all agreeing. Greater transparency of reporting should be driven by scientists, journal editors, reviewers, and grant funders. The conduct of high-quality science that is fully reported should not preclude novelty and innovation in preclinical pain research, and indeed, any efforts that curtail such innovation would be misguided. We believe that to achieve the goal of finding effective new treatments for patients with pain, the pain field needs to deal with these challenging issues.

Implementing a generic method for bias correction in statistical models using random effects, with spatial and population dynamics examples

DEFF Research Database (Denmark)

Thorson, James T.; Kristensen, Kasper

2016-01-01

Statistical models play an important role in fisheries science when reconciling ecological theory with available data for wild populations or experimental studies. Ecological models increasingly include both fixed and random effects, and are often estimated using maximum likelihood techniques...... configurations of an age-structured population dynamics model. This simulation experiment shows that the epsilon-method and the existing bias-correction method perform equally well in data-rich contexts, but the epsilon-method is slightly less biased in data-poor contexts. We then apply the epsilon......-method to a spatial regression model when estimating an index of population abundance, and compare results with an alternative bias-correction algorithm that involves Markov-chain Monte Carlo sampling. This example shows that the epsilon-method leads to a biologically significant difference in estimates of average...

On Distance Scale Bias due to Stellar Multiplicity and Associations

Science.gov (United States)

Anderson, Richard I.; Riess, Adam

2018-01-01

The Cepheid Period-luminosity relation (Leavitt Law) provides the most accurate footing for the cosmic distance scale (CDS). Recently, evidence has been presented that the value of the Hubble constant H0 measured via the cosmic distance scale differs by 3.4σ from the value inferred using Planck data assuming ΛCDM cosmology (Riess et al. 2016). This exciting result may point to missing physics in the cosmological model; however, before such a claim can be made, careful analyses must address possible systematics involved in the calibration of the CDS.A frequently made claim in the literature is that companion stars or cluster membership of Cepheids may bias the calibration of the CDS. To evaluate this claim, we have carried out the first detailed study of the impact of Cepheid multiplicity and cluster membership on the determination of H0. Using deep HST imaging of M31 we directly measured the mean photometric bias due to cluster companions on Cepheid-based distances. Together with the empirical determination of the frequency with which Cepheids appear in clusters we quantify the combined H0 bias from close associations to be approximately 0.3% (0.20 km s-1 Mpc-1) for the passbands commonly used. Thus, we demonstrate that stellar associations cannot explain the aforementioned discrepancy observed in H0 and do not prevent achieving the community goal of measuring H0 with an accuracy of 1%. We emphasize the subtle, but important, difference between systematics relevant for calibrating the Leavitt Law (achieving a better understanding of stellar physics) and for accurately calibrating the CDS (measuring H0).

Effect of negative bias voltage on CrN films deposited by arc ion plating. I. Macroparticles filtration and film-growth characteristics

International Nuclear Information System (INIS)

Wang Qimin; Kim, Kwang Ho

2008-01-01

Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating (AIP) at various negative bias voltages and several groups of N 2 /Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the AIP CrN films. In this part (Part I), the investigations were mainly focused on the macroparticle distributions and film-growth characteristics. The results showed that macroparticle densities on the film surfaces decreased greatly by applying negative bias voltage, which can be affected by partial pressure of N 2 and Ar gases. From the statistical analysis of the experimental results, they proposed a new hybrid mechanism of ion bombardment and electrical repulsion. Also, the growth of the AIP CrN films was greatly altered by applying negative bias voltage. By increasing the bias voltage, the film surfaces became much smoother and the films evolved from apparent columnar microstructures to an equiaxed microstructure. The impinging high-energy Cr ions accelerated by negative bias voltages were deemed the inherent reason for the evolution of growth characteristics

Skin-deep diagnosis: affective bias and zebra retreat complicating the diagnosis of systemic sclerosis.

Science.gov (United States)

Miller, Chad S

2013-01-01

Nearly half of medical errors can be attributed to an error of clinical reasoning or decision making. It is estimated that the correct diagnosis is missed or delayed in between 5% and 14% of acute hospital admissions. Through understanding why and how physicians make these errors, it is hoped that strategies can be developed to decrease the number of these errors. In the present case, a patient presented with dyspnea, gastrointestinal symptoms and weight loss; the diagnosis was initially missed when the treating physicians took mental short cuts and used heuristics as in this case. Heuristics have an inherent bias that can lead to faulty reasoning or conclusions, especially in complex or difficult cases. Affective bias, which is the overinvolvement of emotion in clinical decision making, limited the available information for diagnosis because of the hesitancy to acquire a full history and perform a complete physical examination in this patient. Zebra retreat, another type of bias, is when a rare diagnosis figures prominently on the differential diagnosis but the physician retreats for various reasons. Zebra retreat also factored in the delayed diagnosis. Through the description of these clinical reasoning errors in an actual case, it is hoped that future errors can be prevented or inspiration for additional research in this area will develop.

Survey of basic medical researchers on the awareness of animal experimental designs and reporting standards in China.

Directory of Open Access Journals (Sweden)

Bin Ma

Full Text Available To investigate the awareness and use of the Systematic Review Center for Laboratory Animal Experimentation's (SYRCLE risk-of-bias tool, the Animal Research: Reporting of In Vivo Experiments (ARRIVE reporting guidelines, and Gold Standard Publication Checklist (GSPC in China in basic medical researchers of animal experimental studies.A national questionnaire-based survey targeting basic medical researchers was carried in China to investigate the basic information and awareness of SYRCLE's risk of bias tool, ARRIVE guidelines, GSPC, and animal experimental bias risk control factors. The EpiData3.1 software was used for data entry, and Microsoft Excel 2013 was used for statistical analysis in this study. The number of cases (n and percentage (% of classified information were statistically described, and the comparison between groups (i.e., current students vs. research staff was performed using chi-square test.A total of 298 questionnaires were distributed, and 272 responses were received, which included 266 valid questionnaires (from 118 current students and 148 research staff. Among the 266 survey participants, only 15.8% was aware of the SYRCLE's risk of bias tool, with significant difference between the two groups (P = 0.003, and the awareness rates of ARRIVE guidelines and GSPC were only 9.4% and 9.0%, respectively; 58.6% survey participants believed that the reports of animal experimental studies in Chinese literature were inadequate, with significant difference between the two groups (P = 0.004. In addition, only approximately 1/3 of the survey participants had read systematic reviews and meta-analysis reports of animal experimental studies; only 16/266 (6.0% had carried out/participated in and 11/266 (4.1% had published systematic reviews/meta-analysis of animal experimental studies.The awareness and use rates of SYRCLE's risk-of-bias tool, the ARRIVE guidelines, and the GSPC were low among Chinese basic medical researchers. Therefore

Lessons learnt on biases and uncertainties in personal exposure measurement surveys of radiofrequency electromagnetic fields with exposimeters.

Science.gov (United States)

Bolte, John F B

2016-09-01

Personal exposure measurements of radio frequency electromagnetic fields are important for epidemiological studies and developing prediction models. Minimizing biases and uncertainties and handling spatial and temporal variability are important aspects of these measurements. This paper reviews the lessons learnt from testing the different types of exposimeters and from personal exposure measurement surveys performed between 2005 and 2015. Applying them will improve the comparability and ranking of exposure levels for different microenvironments, activities or (groups of) people, such that epidemiological studies are better capable of finding potential weak correlations with health effects. Over 20 papers have been published on how to prevent biases and minimize uncertainties due to: mechanical errors; design of hardware and software filters; anisotropy; and influence of the body. A number of biases can be corrected for by determining multiplicative correction factors. In addition a good protocol on how to wear the exposimeter, a sufficiently small sampling interval and sufficiently long measurement duration will minimize biases. Corrections to biases are possible for: non-detects through detection limit, erroneous manufacturer calibration and temporal drift. Corrections not deemed necessary, because no significant biases have been observed, are: linearity in response and resolution. Corrections difficult to perform after measurements are for: modulation/duty cycle sensitivity; out of band response aka cross talk; temperature and humidity sensitivity. Corrections not possible to perform after measurements are for: multiple signals detection in one band; flatness of response within a frequency band; anisotropy to waves of different elevation angle. An analysis of 20 microenvironmental surveys showed that early studies using exposimeters with logarithmic detectors, overestimated exposure to signals with bursts, such as in uplink signals from mobile phones and Wi

Transition of poloidal viscosity by electrode biasing in the Large Helical Device

International Nuclear Information System (INIS)

Kitajima, S.; Ishii, K.; Sato, Y.; Kanno, M.; Tachibana, J.; Okamoto, A.; Sasao, M.; Takahashi, H.; Masuzaki, S.; Shoji, M.; Ashikawa, N.; Tokitani, M.; Yokoyama, M.; Suzuki, Y.; Satake, S.; Ido, T.; Shimizu, A.; Suzuki, C.; Inagaki, S.; Takayama, M.

2013-01-01

Electrode biasing experiments were carried out in various magnetic configurations on the Large Helical Device (LHD). The transitions of poloidal viscosity, which were accompanied with bifurcation phenomena characterized by a negative resistance in an electrode characteristic, were clearly observed on LHD by the electrode biasing. The critical external driving force required for transition was compared with the local maximum in ion viscosity, and the radial resistivity before the transition also compared with the expected value from a neoclassical theory. The critical driving force increased and the radial resistivity decreased with the major radius of the magnetic axis R ax going outwards. The configuration dependence of the transition condition and the radial resistivity qualitatively agreed with neoclassical theories. The radial electric field and the viscosity were also evaluated by the neoclassical transport code for a non-axisymmetric system, and estimated electrode voltage required for the transition, which was consistent with the experimental results. (paper)

Mapping species distributions with MAXENT using a geographically biased sample of presence data: a performance assessment of methods for correcting sampling bias.

Science.gov (United States)

Fourcade, Yoan; Engler, Jan O; Rödder, Dennis; Secondi, Jean

2014-01-01

MAXENT is now a common species distribution modeling (SDM) tool used by conservation practitioners for predicting the distribution of a species from a set of records and environmental predictors. However, datasets of species occurrence used to train the model are often biased in the geographical space because of unequal sampling effort across the study area. This bias may be a source of strong inaccuracy in the resulting model and could lead to incorrect predictions. Although a number of sampling bias correction methods have been proposed, there is no consensual guideline to account for it. We compared here the performance of five methods of bias correction on three datasets of species occurrence: one "virtual" derived from a land cover map, and two actual datasets for a turtle (Chrysemys picta) and a salamander (Plethodon cylindraceus). We subjected these datasets to four types of sampling biases corresponding to potential types of empirical biases. We applied five correction methods to the biased samples and compared the outputs of distribution models to unbiased datasets to assess the overall correction performance of each method. The results revealed that the ability of methods to correct the initial sampling bias varied greatly depending on bias type, bias intensity and species. However, the simple systematic sampling of records consistently ranked among the best performing across the range of conditions tested, whereas other methods performed more poorly in most cases. The strong effect of initial conditions on correction performance highlights the need for further research to develop a step-by-step guideline to account for sampling bias. However, this method seems to be the most efficient in correcting sampling bias and should be advised in most cases.

Gender bias against and sexual harassment of AMWA members in Massachusetts.

Science.gov (United States)

Lenhart, S A; Klein, F; Falcao, P; Phelan, E; Smith, K

1991-01-01

Despite the increasing participation of women in medicine over the past few decades, hindrances to professional advancement for women physicians and medical students persist. The present study sought to assess the prevalence of gender bias and sexual harassment in a sample of women physicians and medical students. Within a one-year period, 54% of respondents encountered some form of sex discrimination. In addition, approximately one-fourth experienced sexual harassment (27%) and/or discrimination related to parenthood (24%). Unwanted sexual attention not viewed as sexual harassment was experienced by more than twice as many respondents (55%). Other forms of discrimination were reported as well: age (22%), sexual preference (20%), and race (7%). Perceptions of the extent of sex discrimination and sexual harassment, of their impact on professional commitment, and of the adequacy of solutions at institutions varied directly with whether or not respondents had experienced some form of employment discrimination within the past 12 months. This study points to the need for clarification of what constitutes sexual harassment and for the creation of safe, effective mechanisms to remedy and prevent all forms of gender bias.

On the relative independence of thinking biases and cognitive ability.

Science.gov (United States)

Stanovich, Keith E; West, Richard F

2008-04-01

In 7 different studies, the authors observed that a large number of thinking biases are uncorrelated with cognitive ability. These thinking biases include some of the most classic and well-studied biases in the heuristics and biases literature, including the conjunction effect, framing effects, anchoring effects, outcome bias, base-rate neglect, "less is more" effects, affect biases, omission bias, myside bias, sunk-cost effect, and certainty effects that violate the axioms of expected utility theory. In a further experiment, the authors nonetheless showed that cognitive ability does correlate with the tendency to avoid some rational thinking biases, specifically the tendency to display denominator neglect, probability matching rather than maximizing, belief bias, and matching bias on the 4-card selection task. The authors present a framework for predicting when cognitive ability will and will not correlate with a rational thinking tendency. (c) 2008 APA, all rights reserved.

Assessing the extent of non-stationary biases in GCMs

Science.gov (United States)

Nahar, Jannatun; Johnson, Fiona; Sharma, Ashish

2017-06-01

General circulation models (GCMs) are the main tools for estimating changes in the climate for the future. The imperfect representation of climate models introduces biases in the simulations that need to be corrected prior to their use for impact assessments. Bias correction methods generally assume that the bias calculated over the historical period does not change and can be applied to the future. This study investigates this assumption by considering the extent and nature of bias non-stationarity using 20th century precipitation and temperature simulations from six CMIP5 GCMs across Australia. Four statistics (mean, standard deviation, 10th and 90th quantiles) in monthly and seasonal biases are obtained for three different time window lengths (10, 25 and 33 years) to examine the properties of bias over time. This approach is repeated for two different phases of the Interdecadal Pacific Oscillation (IPO), which is known to have strong influences on the Australian climate. It is found that bias non-stationarity at decadal timescales is indeed an issue over some of Australia for some GCMs. When considering interdecadal variability there are significant difference in the bias between positive and negative phases of the IPO. Regional analyses confirmed these findings with the largest differences seen on the east coast of Australia, where IPO impacts tend to be the strongest. The nature of the bias non-stationarity found in this study suggests that it will be difficult to modify existing bias correction approaches to account for non-stationary biases. A more practical approach for impact assessments that use bias correction maybe to use a selection of GCMs where the assumption of bias non-stationarity holds.

Gender Differentials in Preventive Health Care: Incidences and Determinants among Pakistani Children

OpenAIRE

Faham Masud; Shujaat Farooq

2012-01-01

In this study, an attempt has been made to estimate gender health differential with a focus on preventive health care. Using the Pakistan Demographic Health Survey (PDHS) of 2006-07, the study has targeted the children of age 12-23 months and found substantialsex differences in the immunization status of children where boys are more immunized than girls, reflecting gender biasness over preventive health provision. Through bi-variate and multi-variate analysis, the study found that a variety o...

Codon Usage Bias and Determining Forces in Taenia solium Genome.

Science.gov (United States)

Yang, Xing; Ma, Xusheng; Luo, Xuenong; Ling, Houjun; Zhang, Xichen; Cai, Xuepeng

2015-12-01

The tapeworm Taenia solium is an important human zoonotic parasite that causes great economic loss and also endangers public health. At present, an effective vaccine that will prevent infection and chemotherapy without any side effect remains to be developed. In this study, codon usage patterns in the T. solium genome were examined through 8,484 protein-coding genes. Neutrality analysis showed that T. solium had a narrow GC distribution, and a significant correlation was observed between GC12 and GC3. Examination of an NC (ENC vs GC3s)-plot showed a few genes on or close to the expected curve, but the majority of points with low-ENC (the effective number of codons) values were detected below the expected curve, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified 26 optimal codons in the T. solium genome, all of which ended with either a G or C residue. These optimal codons in the T. solium genome are likely consistent with tRNAs that are highly expressed in the cell, suggesting that mutational and translational selection forces are probably driving factors of codon usage bias in the T. solium genome.

Attentional bias in math anxiety.

Science.gov (United States)

Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

2015-01-01

Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms.

A retrieval-based approach to eliminating hindsight bias.

Science.gov (United States)

Van Boekel, Martin; Varma, Keisha; Varma, Sashank

2017-03-01

Individuals exhibit hindsight bias when they are unable to recall their original responses to novel questions after correct answers are provided to them. Prior studies have eliminated hindsight bias by modifying the conditions under which original judgments or correct answers are encoded. Here, we explored whether hindsight bias can be eliminated by manipulating the conditions that hold at retrieval. Our retrieval-based approach predicts that if the conditions at retrieval enable sufficient discrimination of memory representations of original judgments from memory representations of correct answers, then hindsight bias will be reduced or eliminated. Experiment 1 used the standard memory design to replicate the hindsight bias effect in middle-school students. Experiments 2 and 3 modified the retrieval phase of this design, instructing participants beforehand that they would be recalling both their original judgments and the correct answers. As predicted, this enabled participants to form compound retrieval cues that discriminated original judgment traces from correct answer traces, and eliminated hindsight bias. Experiment 4 found that when participants were not instructed beforehand that they would be making both recalls, they did not form discriminating retrieval cues, and hindsight bias returned. These experiments delineate the retrieval conditions that produce-and fail to produce-hindsight bias.

Reducing neutron multiplicity counting bias for plutonium warhead authentication

Energy Technology Data Exchange (ETDEWEB)

Goettsche, Malte

2015-06-05

Confidence in future nuclear arms control agreements could be enhanced by direct verification of warheads. It would include warhead authentication. This is the assessment based on measurements whether a declaration that a specific item is a nuclear warhead is true. An information barrier can be used to protect sensitive information during measurements. It could for example show whether attributes such as a fissile mass exceeding a threshold are met without indicating detailed measurement results. Neutron multiplicity measurements would be able to assess a plutonium fissile mass attribute if it were possible to show that their bias is low. Plutonium measurements have been conducted with the He-3 based Passive Scrap Multiplicity Counter. The measurement data has been used as a reference to test the capacity of the Monte Carlo code MCNPX-PoliMi to simulate neutron multiplicity measurements. The simulation results with their uncertainties are in agreement with the experimental results. It is essential to use cross-sections which include neutron scattering with the detector's polyethylene molecular structure. Further MCNPX-PoliMi simulations have been conducted in order to study bias that occurs when measuring samples with large plutonium masses such as warheads. Simulation results of solid and hollow metal spheres up to 6000 g show that the masses are underpredicted by as much as 20%. The main source of this bias has been identified in the false assumption that the neutron multiplication does not depend on the position where a spontaneous fission event occurred. The multiplication refers to the total number of neutrons leaking a sample after a primary spontaneous fission event, taking induced fission into consideration. The correction of the analysis has been derived and implemented in a MATLAB code. It depends on four geometry-dependent correction coefficients. When the sample configuration is fully known, these can be exactly determined and remove this type of

An analytical nonlinear magnetoelectric coupling model of laminated composites under combined pre-stress and magnetic bias loadings

International Nuclear Information System (INIS)

Zhou, Hao-Miao; Qu, Shao-Xing; Ou, Xiao-Wei; Xiao, Ying; Wu, Hua-Ping

2013-01-01

Based on the equivalent circuit method, this paper adopts the nonlinear magnetostrictive constitutive relations to establish an analytical nonlinear magnetoelectric coefficient model for magnetostrictive/piezoelectric/magnetostrictive laminated magnetoelectric composites. When the pre-stress is set to zero in the model, the predicted results of the magnetoelectric coefficient coincide well with the available experimental results both qualitatively and quantitatively. Using the model, we can qualitatively predict the influence of the pre-stress, magnetic bias fields and the volume fraction of the magnetostrictive material on the magnetoelectric coefficient. The predicted results show that the influences of the pre-stress on the magnetoelectric coefficient, which varies with the magnetic bias field, before and after reaching the magnetoelectric coefficient maximum, are opposite. That is, the influence of the pre-stress on curves of the magnetoelectric coefficient reverses when the magnetoelectric coefficient reaches its maximum. Therefore, the correct setting of the pre-stress can lower the applied magnetic bias field and improve the magnetoelectric coefficient. The established nonlinear magnetoelectric effect model can provide a theoretical basis for regulating the magnetoelectric coefficient by the pre-stress and magnetic bias field and make it possible to design high-precision miniature magnetoelectric devices. (paper)

Large-scale assembly bias of dark matter halos

Energy Technology Data Exchange (ETDEWEB)

Lazeyras, Titouan; Musso, Marcello; Schmidt, Fabian, E-mail: titouan@mpa-garching.mpg.de, E-mail: mmusso@sas.upenn.edu, E-mail: fabians@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)

2017-03-01

We present precise measurements of the assembly bias of dark matter halos, i.e. the dependence of halo bias on other properties than the mass, using curved 'separate universe' N-body simulations which effectively incorporate an infinite-wavelength matter overdensity into the background density. This method measures the LIMD (local-in-matter-density) bias parameters b {sub n} in the large-scale limit. We focus on the dependence of the first two Eulerian biases b {sup E} {sup {sub 1}} and b {sup E} {sup {sub 2}} on four halo properties: the concentration, spin, mass accretion rate, and ellipticity. We quantitatively compare our results with previous works in which assembly bias was measured on fairly small scales. Despite this difference, our findings are in good agreement with previous results. We also look at the joint dependence of bias on two halo properties in addition to the mass. Finally, using the excursion set peaks model, we attempt to shed new insights on how assembly bias arises in this analytical model.