A double-blind, placebo-controlled, exploratory trial of chromium picolinate in atypical depression: effect on carbohydrate craving.

PubMed

Docherty, John P; Sack, David A; Roffman, Mark; Finch, Manley; Komorowski, James R

2005-09-01

: In a small pilot trial, patients with atypical depression demonstrated significant positive therapeutic response to chromium picolinate. This finding is of interest because of the demonstrated link between depression, decreased insulin sensitivity, and subsequent diabetes and chromium picolinate's insulin enhancing effect. : In this double-blind, multicenter, 8-week replication study, 113 adult outpatients with atypical depression were randomized 2:1 to receive 600 mug/day of elemental chromium, as provided by chromium picolinate (CrPic), or placebo. Primary efficacy measures were the 29-item Hamilton Depression Rating Scale (HAM-D-29) and the Clinical Global Impressions Improvement Scale (CGI-I). : Of the 113 randomized patients, 110 (70 CrPic, 40 placebo) constituted the intent-to-treat (ITT) population (i.e., received at least one dose of study medication and completed at least one efficacy evaluation) and 75 (50 CrPic, 25 placebo) were evaluable (i.e., took at least 80% of study drug with no significant protocol deviations). In the evaluable population, mean age was 46 years, 69% were female, 81% were Caucasian, and mean body mass index (BMI) was 29.7. There was no significant difference between the CrPic and placebo groups in both the ITT and evaluable populations on the primary efficacy measures, with both groups showing significant improvement from baseline on total HAM-D-29 scores during the course of treatment (p < 0.0001). However, in the evaluable population, the CrPic group showed significant improvements from baseline compared with the placebo group on 4 HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. A supplemental analysis of data from the subset of 41 patients in the ITT population with high carbohydrate craving (26 CrPic, 15 placebo; mean BMI = 31.1) showed that the CrPic patients had significantly greater response on total HAM-D-29 scores than the placebo group (65% vs. 33%; p < 0.05) as well as significantly greater improvements on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and genital symptoms (e.g., level of libido). Chromium treatment was well-tolerated. : The study did not include a placebo run-in period, did not require minimum duration or severity of depression, and enrolled patients with major depression, dysthymia, or depression NOS. : In a population of adults with atypical depression, most of whom were overweight or obese, CrPic produced improvement on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. In a subpopulation of patients with high carbohydrate craving, overall HAM-D-29 scores improved significantly in patients treated with CrPic compared with placebo. The results of this study suggest that the main effect of chromium was on carbohydrate craving and appetite regulation in depressed patients and that 600 mug of elemental chromium may be beneficial for patients with atypical depression who also have severe carbohydrate craving. Further studies are needed to evaluate chromium in depressed patients specifically selected for symptoms of increased appetite and carbohydrate craving as well as to determine whether a higher dose of chromium would have an effect on mood.

Studies of a Latent Class Signal Detection Model for Constructed Response Scoring II: Incomplete and Hierarchical Designs. Research Report. ETS RR-10-08

ERIC Educational Resources Information Center

DeCarlo, Lawrence T.

2010-01-01

A basic consideration in large-scale assessments that use constructed response (CR) items, such as essays, is how to allocate the essays to the raters that score them. Designs that are used in practice are incomplete, in that each essay is scored by only a subset of the raters, and also unbalanced, in that the number of essays scored by each rater…

The Effect of Response Bias on the Personality Inventory for DSM-5 (PID-5).

PubMed

McGee Ng, Sarah A; Bagby, R Michael; Goodwin, Brandee E; Burchett, Danielle; Sellbom, Martin; Ayearst, Lindsay E; Dhillon, Sonya; Yiu, Shirley; Ben-Porath, Yossef S; Baker, Spencer

2016-01-01

Valid self-report assessment of psychopathology relies on accurate and credible responses to test questions. There are some individuals who, in certain assessment contexts, cannot or choose not to answer in a manner typically representative of their traits or symptoms. This is referred to, most broadly, as test response bias. In this investigation, we explore the effect of response bias on the Personality Inventory for DSM-5 (PID-5; Krueger, Derringer, Markon, Watson, & Skodol, 2013 ), a self-report instrument designed to assess the pathological personality traits used to inform diagnosis of the personality disorders in Section III of DSM-5. A set of Minnesota Multiphasic Personality Inventory Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 / 2011 ) validity scales, which are used to assess and identify response bias, were employed to identify individuals who engaged in either noncredible overreporting (OR) or underreporting (UR), or who were deemed to be reporting or responding to the items in a "credible" manner-credible responding (CR). A total of 2,022 research participants (1,587 students, 435 psychiatric patients) completed the MMPI-2-RF and PID-5; following protocol screening, these participants were classified into OR, UR, or CR response groups based on MMPI-2-RF validity scale scores. Groups of students and patients in the OR group scored significantly higher on the PID-5 than those students and patients in the CR group, whereas those in the UR group scored significantly lower than those in the CR group. Although future research is needed to explore the effects of response bias on the PID-5, results from this investigation provide initial evidence suggesting that response bias influences scale elevations on this instrument.

Support for an auto-associative model of spoken cued recall: evidence from fMRI.

PubMed

de Zubicaray, Greig; McMahon, Katie; Eastburn, Mathew; Pringle, Alan J; Lorenz, Lina; Humphreys, Michael S

2007-03-02

Cued recall and item recognition are considered the standard episodic memory retrieval tasks. However, only the neural correlates of the latter have been studied in detail with fMRI. Using an event-related fMRI experimental design that permits spoken responses, we tested hypotheses from an auto-associative model of cued recall and item recognition [Chappell, M., & Humphreys, M. S. (1994). An auto-associative neural network for sparse representations: Analysis and application to models of recognition and cued recall. Psychological Review, 101, 103-128]. In brief, the model assumes that cues elicit a network of phonological short term memory (STM) and semantic long term memory (LTM) representations distributed throughout the neocortex as patterns of sparse activations. This information is transferred to the hippocampus which converges upon the item closest to a stored pattern and outputs a response. Word pairs were learned from a study list, with one member of the pair serving as the cue at test. Unstudied words were also intermingled at test in order to provide an analogue of yes/no recognition tasks. Compared to incorrectly rejected studied items (misses) and correctly rejected (CR) unstudied items, correctly recalled items (hits) elicited increased responses in the left hippocampus and neocortical regions including the left inferior prefrontal cortex (LIPC), left mid lateral temporal cortex and inferior parietal cortex, consistent with predictions from the model. This network was very similar to that observed in yes/no recognition studies, supporting proposals that cued recall and item recognition involve common rather than separate mechanisms.

Development and psychometric validation of a scale to assess information needs in cardiac rehabilitation: the INCR Tool.

PubMed

Ghisi, Gabriela Lima de Melo; Grace, Sherry L; Thomas, Scott; Evans, Michael F; Oh, Paul

2013-06-01

To develop and psychometrically validate a tool to assess information needs in cardiac rehabilitation (CR) patients. After a literature search, 60 information items divided into 11 areas of needs were identified. To establish content validity, they were reviewed by an expert panel (N=10). Refined items were pilot-tested in 34 patients on a 5-point Likert-scale from 1 "really not helpful" to 5 "very important". A final version was generated and psychometrically tested in 203 CR patients. Test-retest reliability was assessed via the intraclass correlation coefficient (ICC), the internal consistency using Cronbach's alpha, and criterion validity was assessed with regard to patient's education and duration in CR. Five items were excluded after ICC analysis as well as one area of needs. All 10 areas were considered internally consistent (Cronbach's alpha>0.7). Criterion validity was supported by significant differences in mean scores by educational level (p<0.05) and duration in CR (p<0.001). The mean total score was 4.08 ± 0.53. Patients rated safety as their greatest information need. The INCR Tool was demonstrated to have good reliability and validity. This is an appropriate tool for application in clinical and research settings, assessing patients' needs during CR and as part of education programming. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Development and psychometric evaluation of a cardiovascular risk and disease management knowledge assessment tool.

PubMed

Rosneck, James S; Hughes, Joel; Gunstad, John; Josephson, Richard; Noe, Donald A; Waechter, Donna

2014-01-01

This article describes the systematic construction and psychometric analysis of a knowledge assessment instrument for phase II cardiac rehabilitation (CR) patients measuring risk modification disease management knowledge and behavioral outcomes derived from national standards relevant to secondary prevention and management of cardiovascular disease. First, using adult curriculum based on disease-specific learning outcomes and competencies, a systematic test item development process was completed by clinical staff. Second, a panel of educational and clinical experts used an iterative process to identify test content domain and arrive at consensus in selecting items meeting criteria. Third, the resulting 31-question instrument, the Cardiac Knowledge Assessment Tool (CKAT), was piloted in CR patients to ensure use of application. Validity and reliability analyses were performed on 3638 adults before test administrations with additional focused analyses on 1999 individuals completing both pretreatment and posttreatment administrations within 6 months. Evidence of CKAT content validity was substantiated, with 85% agreement among content experts. Evidence of construct validity was demonstrated via factor analysis identifying key underlying factors. Estimates of internal consistency, for example, Cronbach's α = .852 and Spearman-Brown split-half reliability = 0.817 on pretesting, support test reliability. Item analysis, using point biserial correlation, measured relationships between performance on single items and total score (P < .01). Analyses using item difficulty and item discrimination indices further verified item stability and validity of the CKAT. A knowledge instrument specifically designed for an adult CR population was systematically developed and tested in a large representative patient population, satisfying psychometric parameters, including validity and reliability.

Cancer-Related Direct-to-Consumer Advertising: Awareness, Perceptions, and Reported Impact Among Patients Undergoing Active Cancer Treatment

PubMed Central

Abel, Gregory A.; Burstein, Harold J.; Hevelone, Nathanael D.; Weeks, Jane C.

2009-01-01

Purpose Although cancer-related direct-to-consumer advertising (CR-DTCA) is prevalent, little is known about cancer patients' experiences with this controversial medium of medical communication. Methods We administered a 41-item, mailed questionnaire to consecutive patients with breast and hematologic malignancies who were undergoing active treatment at our institution. We assessed awareness of CR-DTCA within the prior year, perceptions of CR-DTCA, and CR-DTCA–prompted patient and provider behaviors. Results We received 348 completed questionnaires (response rate, 75.0%). Overall, 86.2% reported being aware of CR-DTCA, most frequently from television (77.7%). Awareness did not vary with clinical or sociodemographic factors except that patients were more likely to be aware of CR-DTCA for products specific to their cancer types (P < .0001). A majority of those aware reported that CR-DTCA made them “aware of treatments they did not know about” (62.2%), provided information in “a balanced manner” (65.2%), and helped them to have “better discussions” with their provider (56.8%). These perceptions were significantly more favorable among those who had not graduated from college (P < .05 for each). Overall, 11.2% reported that CR-DTCA made them “less confident” in their providers' judgment. Of those aware, 17.3% reported talking to their provider about an advertised medication, although less than one fifth of those reported receiving a prescription for the advertised medication. Conclusion The patients in our cohort were highly aware of CR-DTCA. CR-DTCA was found to be accessible and useful; however, it decreased some patients' confidence in their providers' judgment. CR-DTCA prompted a modest amount of patient-provider discussion but infrequent patient-reported changes in therapy. PMID:19652071

Career decisions and the structure of training: an American Board Of Colon and Rectal Surgery survey of colorectal residents.

PubMed

Schmitz, Constance C; Rothenberger, David A; Trudel, Judith L; Wolff, Bruce G

2009-07-01

To investigate potential impacts of restructuring general surgery training on colorectal (CR) surgery recruitment and expertise. In response to the American Surgical Association Blue Ribbon Committee report on surgical education (2004), the American Board of Colon and Rectal Surgery, working with the Accreditation Council for Graduate Medical Education and American Board of Surgery, established a committee (2006) to review residency training curricula and study new pathways to certification as a CR surgeon. To address concerns related to shortened general surgery residency, the American Board of Colon and Rectal Surgery committee surveyed recent, current, and entering CR residents on the timing and factors associated with their career choice and opinions regarding restructuring. A 10-item, online survey of 189 CR surgeons enrolled in the class years of 2005, 2006, and 2007 was administered and analyzed May to July 2007. One hundred forty-five CR residents responded (77%); results were consistent across class years and types of general surgery training program. Seventy percent of respondents had rotated onto a CR service by the end of their PGY-2 year. Most identified CR as a career interest in their PGY-3 or PGY-4 year. Overall interest in CR surgery, the influence of CR mentors and teachers, and positive exposure to CR as PGY-3, PGY-4, or PGY-5 residents were the top cited factors influencing choice decisions. Respondents were opposed to restructuring by a 2:1 ratio, primarily because of concerns about inadequate training and lack of time to develop technical expertise. Shortening general surgery residency would not necessarily limit exposure to CR rotations and mentors unless such rotations are cut. The details of proposed restructuring are critical.

Cancer-related direct-to-consumer advertising: awareness, perceptions, and reported impact among patients undergoing active cancer treatment.

PubMed

Abel, Gregory A; Burstein, Harold J; Hevelone, Nathanael D; Weeks, Jane C

2009-09-01

Although cancer-related direct-to-consumer advertising (CR-DTCA) is prevalent, little is known about cancer patients' experiences with this controversial medium of medical communication. We administered a 41-item, mailed questionnaire to consecutive patients with breast and hematologic malignancies who were undergoing active treatment at our institution. We assessed awareness of CR-DTCA within the prior year, perceptions of CR-DTCA, and CR-DTCA-prompted patient and provider behaviors. We received 348 completed questionnaires (response rate, 75.0%). Overall, 86.2% reported being aware of CR-DTCA, most frequently from television (77.7%). Awareness did not vary with clinical or sociodemographic factors except that patients were more likely to be aware of CR-DTCA for products specific to their cancer types (P < .0001). A majority of those aware reported that CR-DTCA made them "aware of treatments they did not know about" (62.2%), provided information in "a balanced manner" (65.2%), and helped them to have "better discussions" with their provider (56.8%). These perceptions were significantly more favorable among those who had not graduated from college (P < .05 for each). Overall, 11.2% reported that CR-DTCA made them "less confident" in their providers' judgment. Of those aware, 17.3% reported talking to their provider about an advertised medication, although less than one fifth of those reported receiving a prescription for the advertised medication. The patients in our cohort were highly aware of CR-DTCA. CR-DTCA was found to be accessible and useful; however, it decreased some patients' confidence in their providers' judgment. CR-DTCA prompted a modest amount of patient-provider discussion but infrequent patient-reported changes in therapy.

Psychometrics of a Child Report Measure of Maternal Support Following Disclosure of Sexual Abuse

PubMed Central

Smith, Daniel W.; Sawyer, Genelle K.; Heck, Nicholas C.; Zajac, Kristyn; Solomon, David; Self-Brown, Shannon; Danielson, Carla K.; Ralston, M. Elizabeth

2018-01-01

Objective The purpose of this study was to develop a psychometrically sound child-report measure of maternal support following disclosure of child sexual abuse. Maternal support following disclosure of child sexual abuse is an important predictor of child adjustment; however, this construct is not well defined, and a psychometrically sound method to assess maternal support from a child’s perspective does not exist. Methods Demographic and abuse-specific information was collected via structured interview from 146 mother-child dyads presenting for an initial forensic evaluation at a child advocacy center. Mothers completed the Maternal Self-report Support Questionnaire, and children completed the Trauma Symptom Checklist for Children and 32 items considered for inclusion in a new measure known as the Maternal Support Questionnaire – Child Report (MSQ-CR). Results Exploratory factor analysis of the MSQ-CR resulted in a three factor solution: Emotional Support (9 items), Skeptical Preoccupation (5 items), and Protection/Retaliation (6 items). Each factor demonstrated adequate internal consistency reliability. Analyses with the Maternal Self-report Support Questionnaire and the Trauma Symptom Checklist supported the construct and concurrent validity of the new measure. Conclusions The MSQ-CR demonstrated sound psychometric properties. Future research is needed to determine whether the MSQ-CR provides a more sensitive approximation of maternal support following disclosure of sexual abuse, relative to measures of global parent-child relations. Additional research is needed to contextualize discrepancies between mother and child ratings of maternal support. Important limitations of the investigation are reviewed. PMID:28471341

A central review of histopathology reports after breast cancer neoadjuvant chemotherapy in the neo-tango trial

PubMed Central

Provenzano, E; Vallier, A-L; Champ, R; Walland, K; Bowden, S; Grier, A; Fenwick, N; Abraham, J; Iddawela, M; Caldas, C; Hiller, L; Dunn, J; Earl, H M

2013-01-01

Background: Neo-tAnGo, a National Cancer Research Network (NCRN) multicentre randomised neoadjuvant chemotherapy trial in early breast cancer, enroled 831 patients in the United Kingdom. We report a central review of post-chemotherapy histopathology reports on the surgical specimens, to assess the presence and degree of response. Methods: A central independent two-reader review (EP and HME) of histopathology reports from post-treatment surgical specimens was performed. The quality and completeness of pathology reporting across all centres was assessed. The reviews included pathological response to chemotherapy (pathological complete response (pCR); minimal residual disease (MRD); and lesser degrees of response), laterality, the number of axillary metastases and axillary nodes, and the type of surgery. A consensus was reached after discussion. Results: In all, 825 surgical reports from 816 patients were available for review. Out of 4125 data items there were 347 discrepant results (8.4% of classifications), which involved 281 patients. These involved grading of breast response (169 but only 9 involving pCR vs MRD); laterality (6); presence of axillary metastasis (35); lymph node counts (108); and type of axillary surgery (29). Excluding cases with pCR, only 45% of reports included any comment regarding response in the breast and 30% in the axillary lymph nodes. Conclusion: We found considerable variability in the completeness of reporting of surgical specimens within this national neoadjuvant breast cancer trial. This highlights the need for consensus guidelines among trial groups on histopathology reporting, and the participation of histopathologists throughout the development and analysis of neoadjuvant trials. PMID:23299526

Cardiac rehabilitation using the Family-Centered Empowerment Model versus home-based cardiac rehabilitation in patients with myocardial infarction: a randomised controlled trial

PubMed Central

Vahedian-Azimi, Amir; Hajiesmaieli, Mohammadreza; Kangasniemi, Mari; Alhani, Fatemah; Jelvehmoghaddam, Hosseinali; Fathi, Mohammad; Farzanegan, Behrooz; Ardehali, Seyed H; Hatamian, Sevak; Gahremani, Mehdi; Mosavinasab, Seyed M M; Rostami, Zohreh; Madani, Seyed J; Izadi, Morteza

2016-01-01

Objective To determine if a hybrid cardiac rehabilitation (CR) programme using the Family-Centered Empowerment Model (FCEM) as compared with standard CR will improve patient quality of life, perceived stress and state anxiety of patients with myocardial infarction (MI). Methods We conducted a randomised controlled trial in which patients received either standard home CR or CR using the FCEM strategy. Patient empowerment was measured with FCEM questionnaires preintervention and postintervention for a total of 9 assessments. Quality of life, perceived stress, and state and trait anxiety were assessed using the 36-Item Short Form Health Survey (SF-36), the 14-item Perceived Stress, and the 20-item State and 20-item Trait Anxiety questionnaires, respectively. Results 70 patients were randomised. Baseline characteristics were similar. Ejection fraction was significantly higher in the intervention group at measurements 2 (p=0.01) and 3 (p=0.001). Exercise tolerance measured as walking distance was significantly improved in the intervention group throughout the study. The quality of life results in the FCEM group showed significant improvement both within the group over time (p<0.0001) and when compared with control (p<0.0001). Similarly, the perceived stress and state anxiety results showed significant improvement both within the FCEM group over time (p<0.0001) and when compared with control (p<0.0001). No significant difference was found either within or between groups for trait anxiety. Conclusions The family-centred empowerment model may be an effective hybrid cardiac rehabilitation method for improving the physical and mental health of patients post-MI; however, further study is needed to validate these findings. Clinical Trials.gov identifier NCT02402582. Trial registration number NCT02402582. PMID:27110376

Assessing children’s competence to consent in research by a standardized tool: a validity study

PubMed Central

2012-01-01

Background Currently over 50% of drugs prescribed to children have not been evaluated properly for use in their age group. One key reason why children have been excluded from clinical trials is that they are not considered able to exercise meaningful autonomy over the decision to participate. Dutch law states that competence to consent can be presumed present at the age of 12 and above; however, in pediatric practice children’s competence is not that clearly presented and the transition from assent to active consent is gradual. A gold standard for competence assessment in children does not exist. In this article we describe a study protocol on the development of a standardized tool for assessing competence to consent in research in children and adolescents. Methods/design In this study we modified the MacCAT-CR, the best evaluated competence assessment tool for adults, for use in children and adolescents. We will administer the tool prospectively to a cohort of pediatric patients from 6 to18 years during the selection stages of ongoing clinical trials. The outcomes of the MacCAT-CR interviews will be compared to a reference standard, established by the judgments of clinical investigators, and an expert panel consisting of child psychiatrists, child psychologists and medical ethicists. The reliability, criterion-related validity and reproducibility of the tool will be determined. As MacCAT-CR is a multi-item scale consisting of 13 items, power was justified at 130–190 subjects, providing a minimum of 10–15 observations per item. MacCAT-CR outcomes will be correlated with age, life experience, IQ, ethnicity, socio-economic status and competence judgment of the parent(s). It is anticipated that 160 participants will be recruited over 2 years to complete enrollment. Discussion A validity study on an assessment tool of competence to consent is strongly needed in research practice, particularly in the child and adolescent population. In this study we will establish a reference standard of children’s competence to consent, combined with validation of an assessment instrument. Results can facilitate responsible involvement of children in clinical trials by further development of guidelines, health-care policies and legal policies. PMID:23009102

Novelty, Age, and IQ: A Theoretical Look at Human Preference for Novelty.

ERIC Educational Resources Information Center

Eaves, Ronald C.; Glen, Roderick

1996-01-01

A study of 86 children (ages 5-16) investigated the relationship between age, IQ, and preferences for novelty. Children with higher IQs spent significantly more time responding to novel items than lower-IQ children. Older children with high IQs showed the most interest in novel items. (CR)

Developing an Adapted Cardiac Rehabilitation Training for Home Care Clinicians

PubMed Central

Russell, David; Mola, Ana; Bowles, Kathryn H.; Lipman, Terri H.

2017-01-01

Purpose: There is limited evidence that home care clinicians receive education on the core competencies of cardiac rehabilitation (CR). This article describes the development and implementation of a CR training program adapted for home care clinicians, which incorporated the viewpoints of homebound patients with cardiovascular disease. Methods: Literature and guideline reviews were performed to glean curriculum content, supplemented with themes identified among patients and clinicians. Semistructured interviews were conducted with homebound patients regarding their perspectives on living with cardiovascular disease and focus groups were held with home care clinicians regarding their perspectives on caring for these patients. Transcripts were analyzed with the constant comparative method. A 15-item questionnaire was administered to home care nurses and rehabilitation therapists pre- and posttraining, and responses were analyzed using a paired sample t test. Results: Three themes emerged among patients: (1) awareness of heart disease; (2) motivation and caregivers' importance; and (3) barriers to attendance at outpatient CR; and 2 additional themes among clinicians: (4) gaps in care transitions; and (5) educational needs. Questionnaire results demonstrated significantly increased knowledge posttraining compared with pretraining among home care clinicians (pretest mean = 12.81; posttest mean = 14.63, P < .001). There was no significant difference between scores for nurses and rehabilitation therapists. Conclusions: Home care clinicians respond well to an adapted CR training to improve care for homebound patients with cardiovascular disease. Clinicians who participated in the training demonstrated an increase in their knowledge and skills of the core competencies for CR. PMID:28033165

Expectations for Visual Function: An Initial Evaluation of a New Clinical Instrument.

ERIC Educational Resources Information Center

Corn, Anne L.; Webne, Steve L.

2001-01-01

A study explored the internal consistency of items in a visual screening instrument developed by Project PAVE: Expectations for Visual Functioning (EVF). The test includes 20 items that evaluate a child's functional use of vision. A pilot test involving 129 teachers indicates the EFV is internally consistent. (Contains three references.) (CR)

Australian Defence Force Requirements for a Group-feeding Ration Pack

DTIC Science & Technology

2010-04-01

items were instant noodles and pasta (20% and 18% of respondents, respectively). 3.1.6 Items Commonly Discarded Beef and Pasta, Fruit Pudding...sheet). Although not usually required, there is provision to supplement the CR5M with a cereal adjunct such as bread, rice, pasta or noodles [6]. It is...of all the drink items. The Chocolate Drink Powder had the highest acceptability; its consumption was second to that of the Instant Coffee. The

Clinical Validation of the Nursing Outcome "Swallowing Status" in People with Stroke: Analysis According to the Classical and Item Response Theories.

PubMed

Oliveira-Kumakura, Ana Railka de Souza; de Araujo, Thelma Leite; Costa, Alice Gabrielle de Sousa; Cavalcante, Tahissa Frota; Lopes, Marcos Venícios de Oliveira; Carvalho, Emilia Campos

2017-09-19

To validate clinically the nursing outcome "Swallowing status". The adjustment of the nursing outcome was investigated according to the Classical and Item Response Theories. The models were compared regarding information loss, goodness-of-fit, and differential item functioning. Stability and internal consistency were examined. The nursing outcome has the best fit in the generalized partial credit model with different discrimination parameters. Strong correlations among the scores of each indicator were observed. There was no differential item functioning of the outcome indicators. The scale presented high internal consistency (Cronbach's α = .954) and stability (and > .800). This study presents a valid nursing outcome. Most accurate monitoring of sensitivity to an intervention. Validar clinicamente o resultado de enefermagem "Estado da Deglutição". MÉTODOS: O ajustamento do resultado foi investigado de acordo com as teorias Clássica e de Resposta ao Item. Os modelos foram comparados assumindo parâmetros de itens cruzados de igual discriminação. Investigaram-se as propriedades de bondade do ajuste, funcionamento diferencial dos itens, estabilidade e consistência interna. O resultado se ajustou melhor a partir do Modelo de crédito parcial generalizado, o qual demonstrou unidimensionalidade do resultado e forte correlação entre os escores de cada indicador. Não houve funcionamento diferencial dos indicadores. A consistência interna para a escala global (Cronbach's α = .954) e a estabilidade (>.800) mantiveram-se elevadas. CONCLUSÃO: O estudo apresenta um resultado de enfermagem válido. RELEVÂNCIA PARA A PRÁTICA CLÍNICA: Maior acurácia para monitorar a sensibilidade da intervenção. © 2017 NANDA International, Inc.

Development, pilot testing and psychometric validation of a short version of the coronary artery disease education questionnaire: The CADE-Q SV.

PubMed

Ghisi, Gabriela Lima de Melo; Sandison, Nicole; Oh, Paul

2016-03-01

To develop, pilot test and psychometrically validate a shorter version of the coronary artery disease education questionnaire (CADE-Q), called CADE-Q SV. Based on previous versions of the CADE-Q, cardiac rehabilitation (CR) experts developed 20 items divided into 5 knowledge domains to comprise the first version of the CADE-Q SV. To establish content validity, they were reviewed by an expert panel (N=12). Refined items were pilot-tested in 20 patients, in which clarity was provided. A final version was generated and psychometrically-tested in 132CR patients. Test-retest reliability was assessed via the intraclass correlation coefficient (ICC), the internal consistency using Cronbach's alpha, and criterion validity with regard to patients' education and duration in CR. All ICC coefficients meet the minimum recommended standard. All domains were considered internally consistent (α>0.7). Criterion validity was supported by significant differences in mean scores by educational level (p<0.01) and duration in CR (p<0.05). Knowledge about exercise and nutrition was higher than knowledge about medical condition. The CADE-Q SV was demonstrated to have good reliability and validity. This is a short, quick and appropriate tool for application in clinical and research settings, assessing patients' knowledge during CR and as part of education programming. Copyright © 2015. Published by Elsevier Ireland Ltd.

Perceiving Cardiac Rehabilitation Staff as Mainly Responsible for Exercise: A Dilemma for Future Self-Management.

PubMed

Flora, Parminder K; McMahon, Casey J; Locke, Sean R; Brawley, Lawrence R

2018-03-01

Cardiac rehabilitation (CR) exercise therapy facilitates patient recovery and better health following a cardiovascular event. However, post-CR adherence to self-managed (SM)-exercise is suboptimal. Part of this problem may be participants' view of CR staff as mainly responsible for help and program structure. Does post-CR exercise adherence for those perceiving high CR staff responsibility suffer as a consequence? Participants in this prospective, observational study were followed over 12 weeks of CR and one month afterward. High perceived staff responsibility individuals were examined for a decline in the strength of adherence-related social cognitions and exercise. Those high and low in perceived staff responsibility were also compared. High perceived staff responsibility individuals reported significant declines in anticipated exercise persistence (d = .58) and number of different SM-exercise options (d = .44). High versus low responsibility comparisons revealed a significant difference in one-month post-CR SM-exercise volume (d = .67). High perceived staff responsibility individuals exercised half of the amount of low responsibility counterparts at one month post-CR. Perceived staff responsibility and CR SRE significantly predicted SM-exercise volume, R 2 adj = .10, and persistence, R 2 adj = .18, one month post-CR. Viewing helpful well-trained CR staff as mainly responsible for participant behavior may be problematic for post-CR exercise maintenance among those more staff dependent. © 2017 The International Association of Applied Psychology.

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

Brandt, C.C.; Benson, S.B.; Beeler, D.A.

The Clinch River Remedial Investigation (CRRI) is designed to address the transport, fate, and distribution of waterborne contaminants (radionuclides, metals, and organic compounds) released from the US Department of Energy`s (DOE`s) Oak Ridge Reservation (ORR) and to assess potential risks to human health and the environment associated with these contaminants. The remedial investigation is entering Phase 2, which has the following items as its objectives: define the nature and extent of the contamination in areas downstream from the DOE ORR, evaluate the human health and ecological risks posed by these contaminants, and perform preliminary identification and evaluation of potential remediationmore » alternatives. This plan describes the requirements, responsibilities, and roles of personnel during sampling, analysis, and data review for the Clinch River Environmental Restoration Program (CR-ERP). The purpose of the plan is to formalize the process for obtaining analytical services, tracking sampling and analysis documentation, and assessing the overall quality of the CR-ERP data collection program to ensure that it will provide the necessary building blocks for the program decision-making process.« less

Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis.

PubMed

Kong, J C; Guerra, G R; Warrier, S K; Lynch, A Craig; Michael, M; Ngan, S Y; Phillips, W; Ramsay, G; Heriot, A G

2018-03-27

The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy; however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature. This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies. There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97; P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively. In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR. Colorectal Disease © 2018 The Association of Coloproctology of Great Britain and Ireland.

Influences on the Consumption of Australian Ration Packs: Review of a Contextual Model and Application to Australian Defence Force Data

DTIC Science & Technology

2011-03-01

to consuming the same product types contained in the ration pack (e.g. instant noodles ). We can speculate that this may be a practice that supports... instant rice. Unpopular items were cheese with bacon, noodles and mulligatawny. Items needing improvement were meat bars cheese and instant milk. 35...complimentary food items (e.g. BBQ Beef might be consumed with rice or noodles ) UNCLASSIFIED 5 UNCLASSIFIED DSTO-TR-2526 the CR5M were found to be of no

Worldwide Emerging Environmental Issues Affecting the U.S. Military

DTIC Science & Technology

2010-08-01

Brazil protecting non-Amazonian tropical forests . A summary of the consultations across the region are presented in the UNDP LAC Regional...North-American Environmental Integration……..13 6.6 World’s Humid Tropical Forests to Suffer Considerable Biodiversity Change by 2100….…13 6.7 Latin...35456&Cr=sanitation&Cr1 Item 2. Food Security Concerns Increase Around the World The Food Security Risk Index 2010 reveals that the countries most

Cognitive ability of preschool, primary and secondary school children in Costa Rica.

PubMed

Rindermann, Heiner; Stiegmaier, Eva-Maria; Meisenberg, Gerhard

2015-05-01

Cognitive abilities of children in Costa Rica and Austria were compared using three age groups (N = 385/366). Cognitive ability tests (mental speed, culture reduced/fluid intelligence, literacy/crystallized intelligence) were applied that differed in the extent to which they refer to school-related knowledge. Preschool children (kindergarten, 5-6 years old, N(CR) = 80, N(Au) = 51) were assessed with the Coloured Progressive Matrices (CPM), primary school children (4th grade, 9-11 years old, N(CR) = 71, N(Au) = 71) with ZVT (a trail-making test), Standard Progressive Matrices (SPM) and items from PIRLS-Reading and TIMSS-Mathematics, and secondary school students (15-16 years old, N(CR) = 48, N(Au) = 48) with ZVT, Advanced Progressive Matrices (APM) and items from PISA-Reading and PISA-Mathematics. Additionally, parents and pupils were given questionnaires covering family characteristics and instruction. Average cognitive abilities were higher in Austria (Greenwich-IQ M(CR) = 87 and M(Au) = 99, d(IQ) = 12 points) and differences were smaller in preschool than in secondary school (d(IQ) = 7 vs 20 points). Differences in crystallized intelligence were larger than in fluid intelligence (mental speed: d(IQ) = 12, Raven: d(IQ) = 10, student achievement tests: d(IQ) = 17 IQ points). Differences were larger in comparisons at the level of g-factors. Austrian children were also taller (6.80 cm, d = 1.07 SD), but had lower body mass index (BMI(CR) = 19.35 vs BMI(Au) = 17.59, d = -0.89 SD). Different causal hypotheses explaining these differences are compared.

Psychometric properties of the Italian version of the Cognitive Reserve Scale (I-CRS).

PubMed

Altieri, Manuela; Siciliano, Mattia; Pappacena, Simona; Roldán-Tapia, María Dolores; Trojano, Luigi; Santangelo, Gabriella

2018-05-04

The original definition of cognitive reserve (CR) refers to the individual differences in cognitive performance after a brain damage or pathology. Several proxies were proposed to evaluate CR (education, occupational attainment, premorbid IQ, leisure activities). Recently, some scales were developed to measure CR taking into account several cognitively stimulating activities. The aim of this study is to adapt the Cognitive Reserve Scale (I-CRS) for the Italian population and to explore its psychometric properties. I-CRS was administered to 547 healthy participants, ranging from 18 to 89 years old, along with neuropsychological and behavioral scales to evaluate cognitive functioning, depressive symptoms, and apathy. Cronbach's α, corrected item-total correlations, and the inter-item correlation matrix were calculated to evaluate the psychometric properties of the scale. Linear regression analysis was performed to build a correction grid of the I-CRS according to demographic variables. Correlational analyses were performed to explore the relationships between I-CRS and neuropsychological and behavioral scales. We found that age, sex, and education influenced the I-CRS score. Young adults and adults obtained higher I-CRS scores than elderly adults; women and participants with high educational attainment scored higher on I-CRS than men and participants with low education. I-CRS score correlated poorly with cognitive and depression scale scores, but moderately with apathy scale scores. I-CRS showed good psychometric properties and seemed to be a useful tool to assess CR in every adult life stage. Moreover, our findings suggest that apathy rather than depressive symptoms may interfere with the building of CR across the lifespan.

Does laboratory cue reactivity correlate with real-world craving and smoking responses to cues?

PubMed

Shiffman, Saul; Li, Xiaoxue; Dunbar, Michael S; Tindle, Hilary A; Scholl, Sarah M; Ferguson, Stuart G

2015-10-01

Laboratory cue reactivity (CR) assessments are used to assess smokers' responses to cues. Likewise, EMA recording is used to characterize real-world response to cues. Understanding the relationship between CR and EMA responses addresses the ecological validity of CR. In 190 daily smokers not currently quitting, craving and smoking responses to cues were assessed in laboratory CR and by real-world EMA recording. Separate CR sessions involved 5 smoking-relevant cues (smoking, alcohol, negative affect, positive affect, smoking prohibitions), and a neutral cue. Subjects used EMA to monitor smoking situations for 3 weeks, completing parallel situational assessments (presence of others smoking, alcohol consumption, negative affect, positive affect, and smoking prohibitions, plus current craving) in smoking and non-smoking occasions (averaging 70 and 60 occasions each). Analyses correlated CR craving and smoking cue responses with EMA craving and smoking correlations with similar cues. Although some cues did not show main effects on average craving or smoking, a wide range of individual differences in response to cues was apparent in both CR and EMA data, providing the necessary context to assess their relationship. Laboratory CR measures of cue response were not correlated with real-world cue responses assessed by EMA. The average correlation was 0.03; none exceeded 0.32. One of 40 correlations examined was significantly greater than 0. Laboratory CR measures do not correlate with EMA-assessed craving or smoking in response to cues, suggesting that CR measures are not accurate predictors of how smokers react to relevant stimuli in the real world. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Factors affecting cardiac rehabilitation referral by physician specialty.

PubMed

Grace, Sherry L; Grewal, Keerat; Stewart, Donna E

2008-01-01

Cardiac rehabilitation (CR) is widely underutilized because of multiple factors including physician referral practices. Previous research has shown CR referral varies by type of provider, with cardiologists more likely to refer than primary care physicians. The objective of this study was to compare factors affecting CR referral in primary care physicians versus cardiac specialists. A cross-sectional survey of a stratified random sample of 510 primary care physicians and cardiac specialists (cardiologists or cardiovascular surgeons) in Ontario identified through the Canadian Medical Directory Online was administered. One hundred four primary care physicians and 81 cardiac specialists responded to the 26-item investigator-generated survey examining medical, demographic, attitudinal, and health system factors affecting CR referral. Primary care physicians were more likely to endorse lack of familiarity with CR site locations (P < .001), lack of standardized referral forms (P < .001), inconvenience (P = .04), program quality (P = .004), and lack of discharge communication from CR (P = .001) as factors negatively impacting CR referral practices than cardiac specialists. Cardiac specialists were significantly more likely to perceive that their colleagues and department would regularly refer patients to CR than primary care physicians (P < .001). Where differences emerged, primary care physicians were more likely to perceive factors that would impede CR referral, some of which are modifiable. Marketing CR site locations, provision of standardized referral forms, and ensuring discharge summaries are communicated to primary care physicians may improve their willingness to refer to CR.

CrMAPK3 regulates the expression of iron-deficiency-responsive genes in Chlamydomonas reinhardtii.

PubMed

Fei, Xiaowen; Yu, Junmei; Li, Yajun; Deng, Xiaodong

2017-05-16

Under iron-deficient conditions, Chlamydomonas exhibits high affinity for iron absorption. Nevertheless, the response, transmission, and regulation of downstream gene expression in algae cells have not to be investigated. Considering that the MAPK pathway is essential for abiotic stress responses, we determined whether this pathway is involved in iron deficiency signal transduction in Chlamydomonas. Arabidopsis MAPK gene sequences were used as entry data to search for homologous genes in Chlamydomonas reinhardtii genome database to investigate the functions of mitogen-activated protein kinase (MAPK) gene family in C. reinhardtii under iron-free conditions. Results revealed 16 C. reinhardtii MAPK genes labeled CrMAPK2-CrMAPK17 with TXY conserved domains and low homology to MAPK in yeast, Arabidopsis, and humans. The expression levels of these genes were then analyzed through qRT-PCR and exposure to high salt (150 mM NaCl), low nitrogen, or iron-free conditions. The expression levels of these genes were also subjected to adverse stress conditions. The mRNA levels of CrMAPK2, CrMAPK3, CrMAPK4, CrMAPK5, CrMAPK6, CrMAPK8, CrMAPK9, and CrMAPK11 were remarkably upregulated under iron-deficient stress. The increase in CrMAPK3 expression was 43-fold greater than that in the control. An RNA interference vector was constructed and transformed into C. reinhardtii 2A38, an algal strain with an exogenous FOX1:ARS chimeric gene, to silence CrMAPK3. After this gene was silenced, the mRNA levels and ARS activities of FOX1:ARS chimeric gene and endogenous CrFOX1 were decreased. The mRNA levels of iron-responsive genes, such as CrNRAMP2, CrATX1, CrFTR1, and CrFEA1, were also remarkably reduced. CrMAPK3 regulates the expression of iron-deficiency-responsive genes in C. reinhardtii.

A Mixed Effects Randomized Item Response Model

ERIC Educational Resources Information Center

Fox, J.-P.; Wyrick, Cheryl

2008-01-01

The randomized response technique ensures that individual item responses, denoted as true item responses, are randomized before observing them and so-called randomized item responses are observed. A relationship is specified between randomized item response data and true item response data. True item response data are modeled with a (non)linear…

Morphological and transcriptional responses of Lycopersicon esculentum to hexavalent chromium in agricultural soil.

PubMed

Li, Shi-Guo; Hou, Jing; Liu, Xin-Hui; Cui, Bao-Shan; Bai, Jun-Hong

2016-07-01

The carcinogenic, teratogenic, and mutagenic effects of hexavalent chromium (Cr[VI]) on living organisms through the food chain raise the immediate need to assess the potential toxicological impacts of Cr(VI) on human health. Therefore, the concentration-dependent responses of 12 Cr(VI)-responsive genes selected from a high-throughput Lycopersicon esculentum complementary DNA microarray were examined at different Cr concentrations. The results indicated that most of the genes were differentially expressed from 0.1 mg Cr/kg soil, whereas the lowest-observable-adverse-effect concentrations of Cr(VI) were 1.6 mg Cr/kg soil, 6.4 mg Cr/kg soil, 3.2 mg Cr/kg soil, and 0.4 mg Cr/kg soil for seed germination, root elongation, root biomass, and root morphology, respectively, implying that the transcriptional method was more sensitive than the traditional method in detecting Cr(VI) toxicity. Dose-dependent responses were observed for the relative expression of expansin (p = 0.778), probable chalcone-flavonone isomerase 3 (p = -0.496), and 12S seed storage protein CRD (p = -0.614); therefore, the authors propose the 3 genes as putative biomarkers in Cr(VI)-contaminated soil. Environ Toxicol Chem 2016;35:1751-1758. © 2015 SETAC. © 2015 SETAC.

Effects of phase II cardiac rehabilitation on job stress and health-related quality of life after return to work in middle-aged patients with acute myocardial infarction.

PubMed

Yonezawa, Ryusuke; Masuda, Takashi; Matsunaga, Atsuhiko; Takahashi, Yumi; Saitoh, Masakazu; Ishii, Akira; Kutsuna, Toshiki; Matsumoto, Takuya; Yamamoto, Kazuya; Aiba, Naoko; Hara, Miyako; Izumi, Tohru

2009-05-01

The aim of the present study was to clarify the effects of phase II cardiac rehabilitation (CR) on job stress and health-related quality of life (HRQOL) after return to work in middle-aged patients with acute myocardial infarction (AMI). A total of 109 middle-aged outpatients (57 +/- 7 years) who completed a phase I CR program after AMI were enrolled, 72 of whom participated in a phase II CR program for 5 months after hospital discharge (CR group) and 37 who discontinued the phase II CR program after the discharge (non-CR group). Job stress was assessed at 6 months after the AMI using a brief job stress questionnaire containing questions related to job stressors, worksite support, level of satisfaction with work or daily life, and psychological distress. HRQOL was assessed using the short-form 36-item health survey (SF-36) at hospital discharge and at 3 and 6 months after the AMI. There were no significant differences in clinical and occupational characteristics between the CR and non-CR groups. The CR group patients exhibited significantly better results for job stressors and psychological distress and higher SF-36 scores at 6 months after the AMI, as compared with those in the non-CR group. These findings suggest that discontinuing a phase II CR program induced chronic psychosocial stress after return to work in these middle-aged post-AMI patients.

The response of CR-39 nuclear track detector to 1-9 MeV protons

DOE PAGES

Sinenian, N.; Rosenberg, M. J.; Manuel, M.; ...

2011-10-28

The response of CR-39 nuclear track detector (TasTrak®) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. The effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather thanmore » the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.« less

The role of complement receptor positive and complement receptor negative B cells in the primary and secondary immune response to thymus independent type 2 and thymus dependent antigens.

PubMed

Lindsten, T; Yaffe, L J; Thompson, C B; Guelde, G; Berning, A; Scher, I; Kenny, J J

1985-05-01

Both complement receptor positive (CR+) and complement receptor negative (CR-) B cells have been shown to be involved in the primary immune response to PC-Hy (phosphocholine conjugated hemocyanin), a thymus dependent (TD) antigen which preferentially induces antibody secretion in Lyb-5+ B cells during a primary adoptive transfer assay. CR+ and CR- B cells also responded in a primary adoptive transfer assay to TNP-Ficoll, a thymus independent type 2 (TI-2) antigen which activates only Lyb-5+ B cells. When the secondary immune response to PC-Hy and TNP-Ficoll were analyzed, it was found that most of the immune memory to both antigens was present in the CR- B cell subset. The CR- B cell subset also dominated the secondary immune response to PC-Hy in immune defective (CBA/N X DBA/2N)F1 male mice. These data indicate that CR- B cells dominate the memory response in both the Lyb-5+ and Lyb-5- B cell subsets of normal and xid immune defective mice and suggest that Lyb-5+ and Lyb-5- B cells can be subdivided into CR+ and CR- subsets.

The Conscientious Responders Scale Helps Researchers Verify the Integrity of Personality Questionnaire Data.

PubMed

Marjanovic, Zdravko; Bajkov, Lisa; MacDonald, Jennifer

2018-01-01

The Conscientious Responders Scale is a five-item embeddable validity scale that differentiates between conscientious and indiscriminate responding in personality-questionnaire data (CR & IR). This investigation presents further evidence of its validity and generalizability across two experiments. Study 1 tests its sensitivity to questionnaire length, a known cause of IR, and tries to provoke IR by manipulating psychological reactance. As expected, short questionnaires produced higher Conscientious Responders Scale scores than long questionnaires, and Conscientious Responders Scale scores were unaffected by reactance manipulations. Study 2 tests concerns that the Conscientious Responders Scale's unusual item content could potentially irritate and baffle responders, ironically increasing rates of IR. We administered two nearly identical questionnaires: one with an embedded Conscientious Responders Scale and one without the Conscientious Responders Scale. Psychometric comparisons revealed no differences across questionnaires' means, variances, interitem response consistencies, and Cronbach's alphas. In sum, the Conscientious Responders Scale is highly sensitive to questionnaire length-a known correlate of IR-and can be embedded harmlessly in questionnaires without provoking IR or changing the psychometrics of other measures.

Modelling in vivo creatine/phosphocreatine in vitro reveals divergent adaptations in human muscle mitochondrial respiratory control by ADP after acute and chronic exercise.

PubMed

Ydfors, Mia; Hughes, Meghan C; Laham, Robert; Schlattner, Uwe; Norrbom, Jessica; Perry, Christopher G R

2016-06-01

Mitochondrial respiratory sensitivity to ADP is thought to influence muscle fitness and is partly regulated by cytosolic-mitochondrial diffusion of ADP or phosphate shuttling via creatine/phosphocreatine (Cr/PCr) through mitochondrial creatine kinase (mtCK). Previous measurements of respiration in vitro with Cr (saturate mtCK) or without (ADP/ATP diffusion) show mixed responses of ADP sensitivity following acute exercise vs. less sensitivity after chronic exercise. In human muscle, modelling in vivo 'exercising' [Cr:PCr] during in vitro assessments revealed novel responses to exercise that differ from detections with or without Cr (±Cr). Acute exercise increased ADP sensitivity when measured without Cr but had no effect ±Cr or with +Cr:PCr, whereas chronic exercise increased sensitivity ±Cr but lowered sensitivity with +Cr:PCr despite increased markers of mitochondrial oxidative capacity. Controlling in vivo conditions during in vitro respiratory assessments reveals responses to exercise that differ from typical ±Cr comparisons and challenges our understanding of how exercise improves metabolic control in human muscle. Mitochondrial respiratory control by ADP (Kmapp ) is viewed as a critical regulator of muscle energy homeostasis. However, acute exercise increases, decreases or has no effect on Kmapp in human muscle, whereas chronic exercise surprisingly decreases sensitivity despite greater mitochondrial content. We hypothesized that modelling in vivo mitochondrial creatine kinase (mtCK)-dependent phosphate-shuttling conditions in vitro would reveal increased sensitivity (lower Kmapp ) after acute and chronic exercise. The Kmapp was determined in vitro with 20 mm Cr (+Cr), 0 mm Cr (-Cr) or 'in vivo exercising' 20 mm Cr/2.4 mm PCr (Cr:PCr) on vastus lateralis biopsies sampled from 11 men before, immediately after and 3 h after exercise on the first, fifth and ninth sessions over 3 weeks. Dynamic responses to acute exercise occurred throughout training, whereby the first session did not change Kmapp with in vivo Cr:PCr despite increases in -Cr. The fifth session decreased sensitivity with Cr:PCr or +Cr despite no change in -Cr. Chronic exercise increased sensitivity ±Cr in association with increased electron transport chain content (+33-62% complexes I-V), supporting classic proposals that link increased sensitivity to oxidative capacity. However, in vivo Cr:PCr reveals a perplexing decreased sensitivity, contrasting the increases seen ±Cr. Functional responses occurred without changes in fibre type or proteins regulating mitochondrial-cytosolic energy exchange (mtCK, VDAC and ANT). Despite the dynamic responses seen with ±Cr, modelling in vivo phosphate-shuttling conditions in vitro reveals that ADP sensitivity is unchanged after high-intensity exercise and is decreased after training. These findings challenge our understanding of how exercise regulates skeletal muscle energy homeostasis. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Durable Complete Response After Discontinuation of Pembrolizumab in Patients With Metastatic Melanoma.

PubMed

Robert, Caroline; Ribas, Antoni; Hamid, Omid; Daud, Adil; Wolchok, Jedd D; Joshua, Anthony M; Hwu, Wen-Jen; Weber, Jeffrey S; Gangadhar, Tara C; Joseph, Richard W; Dronca, Roxana; Patnaik, Amita; Zarour, Hassane; Kefford, Richard; Hersey, Peter; Zhang, Jin; Anderson, James; Diede, Scott J; Ebbinghaus, Scot; Hodi, F Stephen

2017-12-28

Purpose Pembrolizumab provides durable antitumor activity in metastatic melanoma, including complete response (CR) in about 15% of patients. Data are limited on potential predictors of CR and patient disposition after pembrolizumab discontinuation after CR. We describe baseline characteristics and long-term follow-up in patients who experienced CR with pembrolizumab in the KEYNOTE-001 study ( ClinicalTrials.gov identifier: NCT01295827). Patients and Methods Patients with ipilimumab-naive or -treated advanced/metastatic melanoma received one of three dose regimens of pembrolizumab. Eligible patients who received pembrolizumab for ≥ 6 months and at least two treatments beyond confirmed CR could discontinue therapy. Response was assessed every 12 weeks by central Response Evaluation Criteria in Solid Tumors version 1.1. For this analysis, CR was defined per investigator assessment, immune-related response criteria, and potential predictors of CR were evaluated using univariate and multivariate analyses. Results Of 655 treated patients, 105 (16.0%) achieved CR after median follow-up of 43 months. At data cutoff, 92 patients (87.6%) had CR, with median follow-up of 30 months from first CR. Fourteen (13.3%) patients continued to receive treatment for a median of ≥ 40 months. Pembrolizumab was discontinued by 91 patients (86.7%), including 67 (63.8%) who proceeded to observation without additional anticancer therapy. The 24-month disease-free survival rate from time of CR was 90.9% in all 105 patients with CR and 89.9% in the 67 patients who discontinued pembrolizumab after CR for observation. Tumor size and programmed death-ligand 1 status were among the baseline factors independently associated with CR by univariate analysis. Conclusion Patients with metastatic melanoma can have durable complete remission after discontinuation of pembrolizumab, and the low incidence of relapse after median follow-up of approximately 2 years from discontinuation provides hope for a cure for some patients. The mechanisms underlying durable CR require further investigation.

T cell-independent and T cell-dependent immunoglobulin G responses to polyomavirus infection are impaired in complement receptor 2-deficient mice.

PubMed

Szomolanyi-Tsuda, Eva; Seedhom, Mina O; Carroll, Michael C; Garcea, Robert L

2006-08-15

Polyomavirus (PyV) infection induces protective T cell-independent (TI) IgM and IgG antibody responses in T cell-deficient mice, but these responses are not generated by immunization with viral proteins or virus like particles. We hypothesized that innate signals contribute to the generation of isotype-switched antiviral antibody responses. We studied the role of complement receptor (CR2) engagement in TI and T cell-dependent (TD) antibody responses to PyV using CR2-deficient mice. Antiviral IgG responses were reduced by 80-40% in CR2-/- mice compared to wild type. Adoptive transfer experiments demonstrated the need for CR2 not only in TD, but also in TI IgG responses to PyV. Transfer of CR2-/- B lymphocytes to SCID mice resulted in TI antiviral IgG responses that corresponded to 10% of that seen in wild-type B cell-reconstituted mice. Thus, our studies revealed a profound dependence of TI and TD antiviral antibody responses on CR2-mediated signals in PyV-infected mice, where the viral antigen is abundant and persistent.

Chromium genotoxicity: a double-edged sword

PubMed Central

Nickens, Kristen P.; Patierno, Steven R.; Ceryak, Susan

2010-01-01

Certain forms of hexavalent chromium [Cr(VI)] are known respiratory carcinogens that induce a broad spectrum of DNA damage. Cr(VI)-carcinogenesis may be initiated or promoted through several mechanistic processes including, the intracellular metabolic reduction of Cr(VI) producing chromium species capable of interacting with DNA to yield genotoxic and mutagenic effects, Cr(VI)-induced inflammatory/immunological responses, and alteration of survival signaling pathways. Cr(VI) enters the cell through nonspecific anion channels, and is metabolically reduced by agents including ascorbate, glutathione, and cysteine to Cr(V), Cr(IV), and Cr(III). Cr(III) has a weak membrane permeability capacity and is unable to cross the cell membrane, thereby trapping it within the cell where it can bind to DNA and produce genetic damage leading to genomic instability. Structural genetic lesions produced by the intracellular reduction of Cr(VI) include DNA adducts, DNA strand breaks, DNA-protein crosslinks, oxidized bases, abasic sites, and DNA inter- and intrastrand crosslinks. The damage induced by Cr(VI) can lead to dysfunctional DNA replication and transcription, aberrant cell cycle checkpoints, dysregulated DNA repair mechanisms, microsatelite instability, inflammatory responses, and the disruption of key regulatory gene networks responsible for the balance of cell survival and cell death, which may all play an important role in Cr(VI) carcinogenesis. Several lines of evidence have indicated that neoplastic progression is a result of consecutive genetic/epigenetic changes that provide cellular survival advantages, and ultimately lead to the conversion of normal human cells to malignant cancer cells. This review is based on studies that provide a glimpse into Cr(VI) carcinogenicity via mechanisms including Cr(VI)-induced death-resistance, the involvement of DNA repair mechanisms in survival after chromium exposure, and the activation of survival signaling cascades in response to Cr(VI) genotoxicity. PMID:20430016

Field Acceptability and Consumption of CR1M and Potential New Food Items during the Hot Weather Ration Trial

DTIC Science & Technology

2011-11-01

1x50g Krispie Biscuit Apricot Fruit Grains Shortbread Biscuit Instant Beef Noodles Apricot & Coconut Muesli Bar 1x43g 1x15g...86 Cheddar Cheese 47.7 4.5 80 Canned Pears 47.5 4.3 72 Apricot & Coconut Muesli Bar 46.0 3.8 76 20 Instant Beef Noodles 36.3 4.1...Spaghetti Bolognaise) or with complementary food items (e.g. BBQ Beef might be consumed with rice or noodles ). UNCLASSIFIED 6 UNCLASSIFIED DSTO-TN

1999 Survey of Active Duty Personnel: Administration, Datasets, and Codebook. Appendix G: Frequency and Percentage Distributions for Variables in the Survey Analysis Files.

DTIC Science & Technology

2000-12-01

A SKIP FLAG INDICATING THE RESULT OF CHECKING THE RESPONSE ON THE PARENT (SCREENING) ITEM AGAINST THE RESPONSE(S) ON THE ITEMS WITHIN THE SKIP...RESPONSE ON THE PARENT (SCREENING) ITEM AGAINST THE RESPONSE(S) ON THE ITEMS WITHIN THE SKIP PATTERN. SEE TABLE D-5, NOTE 2, IN APPENDIX D. G-52...RESULT OF CHECKING THE RESPONSE ON THE PARENT (SCREENING) ITEM AGAINST THE RESPONSE(S) ON THE ITEMS WITHIN THE SKIP PATTERN. SEE TABLE D-5

Response Mixture Modeling: Accounting for Heterogeneity in Item Characteristics across Response Times.

PubMed

Molenaar, Dylan; de Boeck, Paul

2018-06-01

In item response theory modeling of responses and response times, it is commonly assumed that the item responses have the same characteristics across the response times. However, heterogeneity might arise in the data if subjects resort to different response processes when solving the test items. These differences may be within-subject effects, that is, a subject might use a certain process on some of the items and a different process with different item characteristics on the other items. If the probability of using one process over the other process depends on the subject's response time, within-subject heterogeneity of the item characteristics across the response times arises. In this paper, the method of response mixture modeling is presented to account for such heterogeneity. Contrary to traditional mixture modeling where the full response vectors are classified, response mixture modeling involves classification of the individual elements in the response vector. In a simulation study, the response mixture model is shown to be viable in terms of parameter recovery. In addition, the response mixture model is applied to a real dataset to illustrate its use in investigating within-subject heterogeneity in the item characteristics across response times.

Anti-HER2 CD4(+) T-helper type 1 response is a novel immune correlate to pathologic response following neoadjuvant therapy in HER2-positive breast cancer.

PubMed

Datta, Jashodeep; Berk, Erik; Xu, Shuwen; Fitzpatrick, Elizabeth; Rosemblit, Cinthia; Lowenfeld, Lea; Goodman, Noah; Lewis, David A; Zhang, Paul J; Fisher, Carla; Roses, Robert E; DeMichele, Angela; Czerniecki, Brian J

2015-05-23

A progressive loss of circulating anti-human epidermal growth factor receptor-2/neu (HER2) CD4(+) T-helper type 1 (Th1) immune responses is observed in HER2(pos)-invasive breast cancer (IBC) patients relative to healthy controls. Pathologic complete response (pCR) following neoadjuvant trastuzumab and chemotherapy (T + C) is associated with decreased recurrence and improved prognosis. We examined differences in anti-HER2 Th1 responses between pCR and non-pCR patients to identify modifiable immune correlates to pathologic response following neoadjuvant T + C. Anti-HER2 Th1 responses in 87 HER2(pos)-IBC patients were examined using peripheral blood mononuclear cells pulsed with 6 HER2-derived class II peptides via IFN-γ ELISPOT. Th1 response metrics were anti-HER2 responsivity, repertoire (number of reactive peptides), and cumulative response across 6 peptides (spot-forming cells [SFC]/10(6) cells). Anti-HER2 Th1 responses of non-pCR patients (n = 4) receiving adjuvant HER2-pulsed type 1-polarized dendritic cell (DC1) vaccination were analyzed pre- and post-immunization. Depressed anti-HER2 Th1 responses observed in treatment-naïve HER2(pos)-IBC patients (n = 22) did not improve globally in T + C-treated HER2(pos)-IBC patients (n = 65). Compared with adjuvant T + C receipt, neoadjuvant T + C - utilized in 61.5 % - was associated with higher anti-HER2 Th1 repertoire (p = 0.048). While pCR (n = 16) and non-pCR (n = 24) patients did not differ substantially in demographic/clinical characteristics, pCR patients demonstrated dramatically higher anti-HER2 Th1 responsivity (94 % vs. 33 %, p = 0.0002), repertoire (3.3 vs. 0.3 peptides, p < 0.0001), and cumulative response (148.2 vs. 22.4 SFC/10(6), p < 0.0001) versus non-pCR patients. After controlling for potential confounders, anti-HER2 Th1 responsivity remained independently associated with pathologic response (odds ratio 8.82, p = 0.016). This IFN-γ(+) immune disparity was mediated by anti-HER2 CD4(+)T-bet(+)IFN-γ(+) (i.e., Th1) - not CD4(+)GATA-3(+)IFN-γ(+) (i.e., Th2) - phenotypes, and not attributable to non-pCR patients' immune incompetence, host-level T-cell anergy, or increased immunosuppressive populations. In recruited non-pCR patients, anti-HER2 Th1 repertoire (3.7 vs. 0.5, p = 0.014) and cumulative response (192.3 vs. 33.9 SFC/10(6), p = 0.014) improved significantly following HER2-pulsed DC1 vaccination. Anti-HER2 CD4(+) Th1 response is a novel immune correlate to pathologic response following neoadjuvant T + C. In non-pCR patients, depressed Th1 responses are not immunologically "fixed" and can be restored with HER2-directed Th1 immune interventions. In such high-risk patients, combining HER2-targeted therapies with strategies to boost anti-HER2 Th1 immunity may improve outcomes and mitigate recurrence.

A general theoretical framework for interpreting patient-reported outcomes estimated from ordinally scaled item responses.

PubMed

Massof, Robert W

2014-10-01

A simple theoretical framework explains patient responses to items in rating scale questionnaires. Fixed latent variables position each patient and each item on the same linear scale. Item responses are governed by a set of fixed category thresholds, one for each ordinal response category. A patient's item responses are magnitude estimates of the difference between the patient variable and the patient's estimate of the item variable, relative to his/her personally defined response category thresholds. Differences between patients in their personal estimates of the item variable and in their personal choices of category thresholds are represented by random variables added to the corresponding fixed variables. Effects of intervention correspond to changes in the patient variable, the patient's response bias, and/or latent item variables for a subset of items. Intervention effects on patients' item responses were simulated by assuming the random variables are normally distributed with a constant scalar covariance matrix. Rasch analysis was used to estimate latent variables from the simulated responses. The simulations demonstrate that changes in the patient variable and changes in response bias produce indistinguishable effects on item responses and manifest as changes only in the estimated patient variable. Changes in a subset of item variables manifest as intervention-specific differential item functioning and as changes in the estimated person variable that equals the average of changes in the item variables. Simulations demonstrate that intervention-specific differential item functioning produces inefficiencies and inaccuracies in computer adaptive testing. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Natural and man-made hexavalent chromium, Cr(VI), in groundwater near a mapped plume, Hinkley, California—study progress as of May 2017, and a summative-scale approach to estimate background Cr(VI) concentrations

USGS Publications Warehouse

Izbicki, John A.; Groover, Krishangi D.

2018-03-22

This report describes (1) work done between January 2015 and May 2017 as part of the U.S. Geological Survey (USGS) hexavalent chromium, Cr(VI), background study and (2) the summative-scale approach to be used to estimate the extent of anthropogenic (man-made) Cr(VI) and background Cr(VI) concentrations near the Pacific Gas and Electric Company (PG&E) natural gas compressor station in Hinkley, California. Most of the field work for the study was completed by May 2017. The summative-scale approach and calculation of Cr(VI) background were not well-defined at the time the USGS proposal for the background Cr(VI) study was prepared but have since been refined as a result of data collected as part of this study. The proposed summative scale consists of multiple items, formulated as questions to be answered at each sampled well. Questions that compose the summative scale were developed to address geologic, hydrologic, and geochemical constraints on Cr(VI) within the study area. Each question requires a binary (yes or no) answer. A score of 1 will be assigned for an answer that represents data consistent with anthropogenic Cr(VI); a score of –1 will be assigned for an answer that represents data inconsistent with anthropogenic Cr(VI). The areal extent of anthropogenic Cr(VI) estimated from the summative-scale analyses will be compared with the areal extent of anthropogenic Cr(VI) estimated on the basis of numerical groundwater flow model results, along with particle-tracking analyses. On the basis of these combined results, background Cr(VI) values will be estimated for “Mojave-type” deposits, and other deposits, in different parts of the study area outside the summative-scale mapped extent of anthropogenic Cr(VI).

Psychometrics of a Child Report Measure of Maternal Support following Disclosure of Sexual Abuse.

PubMed

Smith, Daniel W; Sawyer, Genelle K; Heck, Nicholas C; Zajac, Kristyn; Solomon, David; Self-Brown, Shannon; Danielson, Carla K; Ralston, M Elizabeth

2017-04-01

The study examined a new child report measure of maternal support following child sexual abuse. One hundred and forty-six mother-child dyads presenting for a forensic evaluation completed assessments including standardized measures of adjustment. Child participants also responded to 32 items considered for inclusion in a new measure, the Maternal Support Questionnaire-Child Report (MSQ-CR). Exploratory factor analysis of the Maternal Support Questionnaire-Child Report resulted in a three factor, 20-item solution: Emotional Support (9 items), Skeptical Preoccupation (5 items), and Protection/Retaliation (6 items). Each factor demonstrated adequate internal consistency. Construct and concurrent validity of the new measure were supported in comparison to other trauma-specific measures. The Maternal Support Questionnaire-Child Report demonstrated sound psychometric properties. Future research is needed to determine whether the Maternal Support Questionnaire-Child Report provides a more sensitive approximation of maternal support following disclosure of sexual abuse, relative to measures of global parent-child relations and to contextualize discrepancies between mother and child ratings of maternal support.

Measuring Learning and Development in Cross-Cultural Competence

DTIC Science & Technology

2012-09-01

Relativism . .......................................................................................................... 13 Cultural Acuity...Factor Cronbach’s α Number of items Cultural Interest 0.73 6 Cultural Relativism 0.80 10 Cultural Acuity 0.70 8 Relationship Orientation 0.71 7...The factors were labeled as Cultural Interest (CI), Cultural Relativism (CR), Cultural Acuity (CA), Relationship Orientation (RO), and Interpersonal

The Consumer Reports Effectiveness Score: What Did Consumers Report?

ERIC Educational Resources Information Center

Nielsen, Stevan Lars; Smart, David W.; Isakson, Richard L.; Worthen, Vaughn E.; Gregersen, Ann T.; Lambert, Michael J.

2004-01-01

From readers' ratings of satisfaction, problem resolution, and perceived emotional change during treatment, Consumer Reports magazine (CR, 1995) concluded both that psychotherapy is effective and that longer, more intensive therapy is more effective. The authors compared prospectively gathered 45-Item Outcome Questionnaire scores (OQ-45; M. J.…

Tumor RNA disruption predicts survival benefit from breast cancer chemotherapy.

PubMed

Parissenti, Amadeo M; Guo, Baoqing; Pritzker, Laura B; Pritzker, Kenneth P H; Wang, Xiaohui; Zhu, Mu; Shepherd, Lois E; Trudeau, Maureen E

2015-08-01

In a prior substudy of the CAN-NCIC-MA.22 clinical trial (ClinicalTrials.gov identifier NCT00066443), we observed that neoadjuvant chemotherapy reduced tumor RNA integrity in breast cancer patients, a phenomenon we term "RNA disruption." The purpose of the current study was to assess in the full patient cohort the relationship between mid-treatment tumor RNA disruption and both pCR post-treatment and, subsequently, disease-free survival (DFS) up to 108 months post-treatment. To meet these objectives, we developed the RNA disruption assay (RDA) to quantify RNA disruption and stratify it into 3 response zones of clinical importance. Zone 1 is a level of RNA disruption inadequate for pathologic complete response (pCR); Zone 2 is an intermediate level, while Zone 3 has high RNA disruption. The same RNA disruption cut points developed for pCR response were then utilized for DFS. Tumor RDA identified >fourfold more chemotherapy non-responders than did clinical response by calipers. pCR responders were clustered in RDA Zone 3, irrespective of tumor subtype. DFS was about 2-fold greater for patients with tumors in Zone 3 compared to Zone 1 patients. Kaplan-Meier survival curves corroborated these findings that high tumor RNA disruption was associated with increased DFS. DFS values for patients in zone 3 that did not achieve a pCR were similar to that of pCR recipients across tumor subtypes, including patients with hormone receptor positive tumors that seldom achieve a pCR. RDA appears superior to pCR as a chemotherapy response biomarker, supporting the prospect of its use in response-guided chemotherapy.

Reliability of abstracting performance measures: results of the cardiac rehabilitation referral and reliability (CR3) project.

PubMed

Thomas, Randal J; Chiu, Jensen S; Goff, David C; King, Marjorie; Lahr, Brian; Lichtman, Steven W; Lui, Karen; Pack, Quinn R; Shahriary, Melanie

2014-01-01

Assessment of the reliability of performance measure (PM) abstraction is an important step in PM validation. Reliability has not been previously assessed for abstracting PMs for the referral of patients to cardiac rehabilitation (CR) and secondary prevention (SP) programs. To help validate these PMs, we carried out a multicenter assessment of their reliability. Hospitals and clinical practices from around the United States were invited to participate in the Cardiac Rehabilitation Referral Reliability (CR3) Project. Twenty-nine hospitals and 23 outpatient centers expressed interest in participating. Seven hospitals and 6 outpatient centers met participation criteria and submitted completed data. Site coordinators identified 35 patients whose charts were reviewed by 2 site abstractors twice, 1 week apart. Percent agreement and the Cohen κ statistic were used to describe intra- and interabstractor reliability for patient eligibility for CR/SP, patient exceptions for CR/SP referral, and documented referral to CR/SP. Results were obtained from within-site data, as well as from pooled data of all inpatient and all outpatient sites. We found that intra-abstractor reliability reflected excellent repeatability (≥ 90% agreement; κ ≥ 0.75) for ratings of CR/SP eligibility, exceptions, and referral, both from pooled and site-specific analyses of inpatient and outpatient data. Similarly, the interabstractor agreement from pooled analysis ranged from good to excellent for the 3 items, although with slightly lower measures of reliability. Abstraction of PMs for CR/SP referral has high reliability, supporting the use of these PMs in quality improvement initiatives aimed at increasing CR/SP delivery to patients with cardiovascular disease.

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

Roy, Ram Vinod; Pratheeshkumar, Poyil; Son, Yong-O

Hexavalent chromium (Cr(VI)) is classified as a human carcinogen. Cr(VI) has been associated with adenocarcinomas and squamous cell carcinoma of the lung. The present study shows that acute Cr(VI) treatment in human bronchial epithelial cells (BEAS-2B) increased inflammatory responses (TNF-α, COX-2, and NF-кB/p65) and expression of Nrf2. Cr(VI)-induced generation of reactive oxygen species (ROS) are responsible for increased inflammation. Despite the fact that Nrf2 is a master regulator of response to oxidative stress, silencing of Nrf2 in the acute Cr(VI) treatment had no effect on Cr(VI)-induced inflammation. In contrast, in Cr(VI)-transformed (CrT) cells, Nrf2 is constitutively activated. Knock-down of thismore » protein resulted in decreased inflammation, while silencing of SOD2 and CAT had no effect in the expression of these inflammatory proteins. Results obtained from the knock-down of Nrf2 in CrT cells are very different from the results obtained in the acute Cr(VI) treatment. In BEAS-2B cells, knock-down of Nrf2 had no effect in the inflammation levels, while in CrT cells a decrease in the expression of inflammation markers was observed. These results indicate that before transformation, ROS plays a critical role while Nrf2 not in Cr(VI)-induced inflammation, whereas after transformation (CrT cells), Nrf2 is constitutively activated and this protein maintains inflammation while ROS not. Constitutively high levels of Nrf2 in CrT binds to the promoter regions of COX-2 and TNF-α, leading to increased inflammation. Collectively, our results demonstrate that before cell transformation ROS are important in Cr(VI)-induced inflammation and after transformation a constitutively high level of Nrf2 is important. - Highlights: • Cr(VI)-induced ROS increased inflammation, while Nrf2 had no effect. • In the CrT cells knock-down of Nrf2 resulted in decreased inflammation. • Mechanistic differences in regulating Cr(VI)-induced inflammation.« less

Regulation of Dynamic Behavior of Retinal Microglia by CX3CR1 Signaling

PubMed Central

Liang, Katharine J.; Lee, Jung Eun; Wang, Yunqing D.; Ma, Wenxin; Fontainhas, Aurora M.; Fariss, Robert N.; Wong, Wai T.

2009-01-01

PURPOSE Microglia in the central nervous system display a marked structural dynamism in their processes in the resting state. This dynamic behavior, which may play a constitutive surveying role in the uninjured neural parenchyma, is also highly responsive to tissue injury. The role of CX3CR1, a chemokine receptor expressed in microglia, in regulating microglia morphology and dynamic behavior in the resting state and after laser-induced focal injury was examined. METHODS Time-lapse confocal imaging of retinal explants was used to evaluate the dynamic behavior of retinal microglia labeled with green fluorescent protein (GFP). Transgenic mice in which CX3CR1 signaling was ablated (CX3CR1GFP/GFP/CX3CR1−/−) and preserved (CX3CR1+/GFP/CX3CR1+/−) were used. RESULTS Retinal microglial density, distribution, cellular morphology, and overall retinal tissue anatomy were not altered in young CX3CR1−/− animals. In the absence of CX3CR1, retinal microglia continued to exhibit dynamic motility in their processes. However, rates of process movement were significantly decreased, both under resting conditions and in response to tissue injury. In addition, microglia migration occurring in response to focal laser injury was also significantly slowed in microglia lacking CX3CR1. CONCLUSIONS CX3CR1 signaling in retinal microglia, though not absolutely required for the presence of microglial dynamism, plays a role in potentiating the rate of retinal microglial process dynamism and cellular migration. CX3CL1 signaling from retinal neurons and endothelial cells likely modulates dynamic microglia behavior so as to influence the level of microglial surveillance under basal conditions and the rate of dynamic behavior in response to tissue injury. PMID:19443728

Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

PubMed

Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

2013-07-01

Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

An NCME Instructional Module on Polytomous Item Response Theory Models

ERIC Educational Resources Information Center

Penfield, Randall David

2014-01-01

A polytomous item is one for which the responses are scored according to three or more categories. Given the increasing use of polytomous items in assessment practices, item response theory (IRT) models specialized for polytomous items are becoming increasingly common. The purpose of this ITEMS module is to provide an accessible overview of…

Cyclophosphamide, bortezomib and dexamethasone (CyBorD) induction for newly diagnosed multiple myeloma: High response rates in a phase II clinical trial

PubMed Central

Reeder, Craig B.; Reece, Donna E.; Kukreti, Vishal; Chen, Christine; Trudel, Suzanne; Hentz, Joseph; Noble, Brie; Pirooz, Nicholas A.; Spong, Jacy E.; Piza, Jesus G.; Zepeda, Victor H. Jimenez; Mikhael, Joseph R.; Leis, Jose F.; Bergsagel, P. Leif; Fonseca, Rafael; Stewart, A. Keith

2009-01-01

We have studied a three drug combination with bortezomib, cyclophosphamide and dexamethasone (CyBorD) on a 28 day cycle in the treatment of newly diagnosed multiple myeloma patients to assess response and toxicity. The primary endpoint of response was evaluated after four cycles. Thirty-three newly diagnosed, symptomatic patients with multiple myeloma received bortezomib 1.3 mg/m2 intravenously on days 1, 4, 8, 11, cyclophosphamide 300 mg/m2 orally days 1, 8, 15, 22 and dexamethasone 40 mg orally days 1-4, 9-12, 17-20 on a 28 day cycle for four cycles. Responses were rapid with a mean 80% decline in the sentinel monoclonal protein at the end of two cycles. The overall intent to treat response rate (≥ partial response) was 88% with 61% ≥VGPR and 39% CR/nCR. For the 28 patients that completed all 4 cycles of therapy the CR/nCR rate was 46% and ≥VGPR rate 71%. All patients undergoing stem cell harvest had a successful collection. Twenty three patients underwent SCT and are evaluable through day 100 with CR/nCR documented in 70% and ≥VGPR in 74%. In conclusion, CyBorD produces a rapid and profound response in patients with newly diagnosed multiple myeloma with manageable toxicity. PMID:19225538

Biofilm Shows Spatially Stratified Metabolic Responses to Contaminant Exposure

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

Cao, Bin; Majors, Paul D.; Ahmed, B.

2012-11-01

The objective of this study was to elucidate the spatiotemporal responses of live S. oneidensis MR-1 biofilms to U(VI) (uranyl, UO22+) and Cr(VI) (chromate, CrO42-), important environmental contaminants at DOE contaminated sites. Toward this goal, we applied noninvasive nuclear magnetic resonance (NMR) imaging, diffusion, relaxation and spectroscopy techniques to monitor in situ spatiotemporal responses of S. oneidensis biofilms to U(VI) and Cr(VI) exposure in terms of changes in biofilm structures, diffusion properties, and cellular metabolism. Exposure to U(VI) or Cr(VI) did not appear to change the overall biomass distribution but caused changes in the physicochemical microenvironments inside the biofilm asmore » indicated by diffusion measurements. Changes in the diffusion properties of the biofilms in response to U(VI) and Cr(VI) exposure imply a novel function of the extracellular polymeric substances (EPS) affecting the biotransformation and transport of contaminants in the environment. In the presence of U(VI) or Cr(VI), the anaerobic metabolism of lactate was inhibited significantly, although the biofilms were still capable of reducing U(VI) and Cr(VI). Local concentrations of Cr(III)aq in the biofilm suggested relatively high Cr(VI) reduction activities at the top of the biofilm, near the medium-biofilm interface. The depth-resolved metabolic activities of the biofilm suggested higher diversion effects of gluconeogenesis and C1 metabolism pathways at the bottom of the biofilm and in the presence of U(VI). This study provides a noninvasive means to investigate spatiotemporal responses of biofilms, including surface-associated microbial communities in engineering, natural and medical settings, to various environmental perturbations including exposure to environmental contaminants and antimicrobials.« less

Mild caloric restriction up-regulates the expression of prohibitin: A proteome study

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

Takahashi, Shoko; Masuda, Junko; Shimagami, Hiroshi

2011-02-18

Research highlights: {yields} Proteomic analysis was performed to elucidate physiological alterations induced by mild CR. {yields} The results suggest good reproducibility and possibility to grasp the important response of CR. {yields} The increase in prohibitin abundance was observed in CR groups by proteomic analysis. {yields} We hypothesize that prohibitin might be involved in the longevity induced by CR. -- Abstract: Caloric restriction (CR) is well known to expand lifespan in a variety of species and to retard many age-related diseases. The effects of relatively mild CR on the proteome profile in relation to lifespan have not yet been reported, despitemore » the more extensive studies of the stricter CR conditions. Thus, the present study was conducted to elucidate the protein profiles in rat livers after mild CR for a relatively short time. Young growing rats were fed CR diets (10% and 30% CR) for 1 month. We performed the differential proteomic analysis of the rat livers using two-dimensional electrophoresis combined with MALDI-TOF mass spectrometry. The most remarkable protein among the differentially expressed proteins was found to be prohibitin, the abundance of which was increased by 30% CR. Prohibitin is a ubiquitously expressed protein shown to suppress cell proliferation and to be related to longevity. The increase in prohibitin was observed both in 10% and 30% CR by Western blot analysis. Furthermore, induction of AMP-activated kinase (AMPK) protein, related to the actions of prohibitin in promoting longevity, was observed. The increased prohibitin level in response to subtle CR suggests that this increase may be one of the early events leading to the expansion of lifespan in response to CR.« less

Ramsay-Curve Item Response Theory for the Three-Parameter Logistic Item Response Model

ERIC Educational Resources Information Center

Woods, Carol M.

2008-01-01

In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters of a unidimensional item response model using marginal maximum likelihood estimation. This study evaluates RC-IRT for the three-parameter logistic (3PL) model with comparisons to the normal model and to the empirical…

Using the Nominal Response Model to Evaluate Response Category Discrimination in the PROMIS Emotional Distress Item Pools

ERIC Educational Resources Information Center

Preston, Kathleen; Reise, Steven; Cai, Li; Hays, Ron D.

2011-01-01

The authors used a nominal response item response theory model to estimate category boundary discrimination (CBD) parameters for items drawn from the Emotional Distress item pools (Depression, Anxiety, and Anger) developed in the Patient-Reported Outcomes Measurement Information Systems (PROMIS) project. For polytomous items with ordered response…

Role of follow-up endoscopic examination in treatment response assessment for patients with gastric diffuse large B cell lymphoma.

PubMed

Yoon, Seung Bae; Lee, In Seok; Lee, Ha Ni; Kim, Eunyoung; Kim, Woohyeon; Lee, Han Hee; Lee, Bo-In; Choi, Myung-Gyu; Jung, Seung Eun; Choi, Byung Ock; Park, Gyeong Sin; Cho, Seok-Goo

2016-09-01

According to lymphoma guidelines, gastric diffuse large B cell lymphoma (DLBCL) patients should undergo regular computed tomography (CT) and/or positron emission tomography (PET) examinations to assess treatment response. Endoscopic examinations are not indicated in the guidelines. The aim of this study was to investigate the utility of endoscopic examinations during and after treatment for DLBCL. We reviewed the patients diagnosed with gastric DLBCL at Seoul St. Mary's Hospital. All patients underwent endoscopy and radiologic examinations at every follow-up appointment. Radiologic response was defined according to World Health Organization criteria and endoscopic response was determined based on the Groupe d'Etude des Lymphomes de l'Adult grading system that is widely used in post-treatment evaluation of gastric MALT lymphoma. Forty-five patients were analyzed. Within a median follow-up period of 34 months, 35 patients achieved both radiologic and endoscopic complete remission (CR). The median times to endoscopic and radiologic CR were not significantly different (21 versus 16 weeks, p = 0.118). However, in 25 patients with stage I disease, endoscopic CR [median (range), 20 (11-36)] was achieved later than radiologic CR [median (range), 13 (8-36)] (p = 0.027). Among 40 patients who achieved radiologic CR, 35 patients who also achieved endoscopic CR maintained remission during the follow-up. Two of the five patients who achieved radiologic CR without endoscopic CR experienced recurrence. In gastric DLBCL patients, endoscopic response does not always correlate with radiologic response and might predict disease recurrence. We suggest that follow-up endoscopic examination with biopsy should be performed in addition to radiologic examination.

The development of an energy-independent personnel neutron dosimeter using CR-39

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

Doremus, S.W.

The addition of specialized (n,{alpha}) radiators to a standard polyethylene/CR-39 (PE/CR-39) neutron dosimetry system was evaluated for improved response to low energy neutrons. Specialized radiators consisting of poly(vinyl alcohol) complexed with boron (natural and enriched boron-10) and poly(acrylic acid) complexed with lithium (enriched lithium-6) were evaluated. The complexion of boron with poly(vinyl alcohol) was accomplished by incorporation or surface coating. The complexion of lithium with poly(acrylic acid) was exclusively performed by incorporation. The dosimeter was designed such that the specialized radiator was in contact with the CR-39 detector (i.e., the specialized radiator was sandwiched between the CR-39 detector and polyethylenemore » radiator). The neutron response of this dosimetry system was investigated using {sup 252}Cf (moderated and bare) spontaneous fission neutrons. Detectors were chemically etched and then read with a Nikon OPTIPHOT microscope. The mean response (tracks {center dot} field{sup {minus}1}) of detectors treated with specialized (n,{alpha}) radiators were evaluated against PE/CR-39 controls. The results of this investigation demonstrate that PE/CR-39 dosimeters equipped with specialized (n,{alpha}) radiators have a noticeable response to low energy neutrons that in many instances is significantly greater than that of the controls. The addition of specialized radiators to this dosimetry system did not effect (diminish) its response to fast neutrons.« less

Thermoregulatory, Cardiovascular, and Metabolic Responses to Mild Caloric Restriction in the Brown Norway Rat

EPA Science Inventory

Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known on the regulation of CR-induced h...

77 FR 51580 - Advisory Committee on Reactor Safeguards; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... Pike, Rockville, Maryland. Thursday, September 6, 2012, Conference Room T2-B1, 11545 Rockville Pike... p.m.-3:15 p.m.: Selected Chapters of the Safety Evaluation Reports (SERs) with Open Items Associated... and Peach Bottom,'' and (2) NUREG/CR-7040, ``Evaluation of JNES Equipment Fragility Tests for Use in...

A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

ERIC Educational Resources Information Center

Fukuhara, Hirotaka; Kamata, Akihito

2011-01-01

A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

Item Response Models for Examinee-Selected Items

ERIC Educational Resources Information Center

Wang, Wen-Chung; Jin, Kuan-Yu; Qiu, Xue-Lan; Wang, Lei

2012-01-01

In some tests, examinees are required to choose a fixed number of items from a set of given items to answer. This practice creates a challenge to standard item response models, because more capable examinees may have an advantage by making wiser choices. In this study, we developed a new class of item response models to account for the choice…

Detecting Differential Item Discrimination (DID) and the Consequences of Ignoring DID in Multilevel Item Response Models

ERIC Educational Resources Information Center

Lee, Woo-yeol; Cho, Sun-Joo

2017-01-01

Cross-level invariance in a multilevel item response model can be investigated by testing whether the within-level item discriminations are equal to the between-level item discriminations. Testing the cross-level invariance assumption is important to understand constructs in multilevel data. However, in most multilevel item response model…

An NCME Instructional Module on Latent DIF Analysis Using Mixture Item Response Models

ERIC Educational Resources Information Center

Cho, Sun-Joo; Suh, Youngsuk; Lee, Woo-yeol

2016-01-01

The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called…

Forced-Choice Assessment of Work-Related Maladaptive Personality Traits: Preliminary Evidence From an Application of Thurstonian Item Response Modeling.

PubMed

Guenole, Nigel; Brown, Anna A; Cooper, Andrew J

2018-06-01

This article describes an investigation of whether Thurstonian item response modeling is a viable method for assessment of maladaptive traits. Forced-choice responses from 420 working adults to a broad-range personality inventory assessing six maladaptive traits were considered. The Thurstonian item response model's fit to the forced-choice data was adequate, while the fit of a counterpart item response model to responses to the same items but arranged in a single-stimulus design was poor. Monotrait heteromethod correlations indicated corresponding traits in the two formats overlapped substantially, although they did not measure equivalent constructs. A better goodness of fit and higher factor loadings for the Thurstonian item response model, coupled with a clearer conceptual alignment to the theoretical trait definitions, suggested that the single-stimulus item responses were influenced by biases that the independent clusters measurement model did not account for. Researchers may wish to consider forced-choice designs and appropriate item response modeling techniques such as Thurstonian item response modeling for personality questionnaire applications in industrial psychology, especially when assessing maladaptive traits. We recommend further investigation of this approach in actual selection situations and with different assessment instruments.

Selective Detection of NO2 Using Cr-Doped CuO Nanorods

PubMed Central

Kim, Kang-Min; Jeong, Hyun-Mook; Kim, Hae-Ryong; Choi, Kwon-Il; Kim, Hyo-Joong; Lee, Jong-Heun

2012-01-01

CuO nanosheets, Cr-doped CuO nanosheets, and Cr-doped CuO nanorods were prepared by heating a slurry containing Cu-hydroxide/Cr-hydroxide. Their responses to 100 ppm NO2, C2H5OH, NH3, trimethylamine, C3H8, and CO were measured. For 2.2 at% Cr-doped CuO nanorods, the response (Ra/Rg, Ra: resistance in air, Rg: resistance in gas) to 100 ppm NO2 was 134.2 at 250 °C, which was significantly higher than that of pure CuO nano-sheets (Ra/Rg = 7.5) and 0.76 at% Cr-doped CuO nanosheets (Ra/Rg = 19.9). In addition, the sensitivity for NO2 was also markedly enhanced by Cr doping. Highly sensitive and selective detection of NO2 in 2.2 at% Cr-doped CuO nanorods is explained in relation to Cr-doping induced changes in donor density, morphology, and catalytic effects. PMID:22969384

A Quasi-Parametric Method for Fitting Flexible Item Response Functions

ERIC Educational Resources Information Center

Liang, Longjuan; Browne, Michael W.

2015-01-01

If standard two-parameter item response functions are employed in the analysis of a test with some newly constructed items, it can be expected that, for some items, the item response function (IRF) will not fit the data well. This lack of fit can also occur when standard IRFs are fitted to personality or psychopathology items. When investigating…

[Reliability and validity of Meaningful Life Measure-Chinese Revised in Chinese college students].

PubMed

Xiao, Rong; Lai, Qiao-Zhen; Yang, Jia-Ping

2016-04-20

To test the reliability and validity of Meaningful Life Measure-Chinese Revised (MLM-CR) in Chinese college students. A total of 1035 college students were evaluated with MLM-CR, Satisfaction with Life Scale (SWLS), Purpose in Life (PIL) and Patient Health Questionnaire-2 (PHQ-2), and 120 of the students were examined with PIL-SF twice. All the items in MLM-CR had good discrimination indexes (r=0.753-0.838, P<0.001). Confirmatory factor analysis confirmed the hypothesized five-factor model of MLM-CR (Χ 2 /df=3.4, GFI=0.946, AGFI=0.924, RMR=0.069, NFI=0.953, CFI=0.966, RMSEA=0.048). The total internal consistency reliability of MLM-CR was 0.942, and the alpha coefficients of the 5 dimensions ranged from 0.782 to 0.877; the total split-half reliability was 0.920, and the split-half reliability of the 5 dimensions ranged from 0.752 to 0.830; the total test-retest reliability was 0.871, and the test-retest reliability of the 5 dimensions ranged from 0.783 to 0.805. The criterion validity of MLM-CR in correlation with SWLS, PIL and PHQ-2 was 0.66, 0.755 and -0.388, respectively (P<0.01). The Average score of MLM-CR of the college students was 5.20∓0.90, and the scores were significantly higher in female students than in the male students (P<0.001). MLM-CR has good psychometric properties for application in comprehensive evaluation of personal meaning in life.

Qualitative Development of the PROMIS® Pediatric Stress Response Item Banks

PubMed Central

Gardner, William; Pajer, Kathleen; Riley, Anne W.; Forrest, Christopher B.

2013-01-01

Objective To describe the qualitative development of the Patient-Reported Outcome Measurement Information System (PROMIS®) Pediatric Stress Response item banks. Methods Stress response concepts were specified through a literature review and interviews with content experts, children, and parents. A library comprising 2,677 items derived from 71 instruments was developed. Items were classified into conceptual categories; new items were written and redundant items were removed. Items were then revised based on cognitive interviews (n = 39 children), readability analyses, and translatability reviews. Results 2 pediatric Stress Response sub-domains were identified: somatic experiences (43 items) and psychological experiences (64 items). Final item pools cover the full range of children’s stress experiences. Items are comprehensible among children aged ≥8 years and ready for translation. Conclusions Child- and parent-report versions of the item banks assess children’s somatic and psychological states when demands tax their adaptive capabilities. PMID:23124904

Association of Clinical Response and Long-term Outcome Among Patients With Biopsied Orbital Pseudotumor Receiving Modern Radiation Therapy

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

Prabhu, Roshan S., E-mail: rprabhu@emory.edu; Kandula, Shravan; Liebman, Lang

2013-03-01

Purpose: To retrospectively evaluate institutional outcomes for patients treated with modern radiation therapy (RT) for biopsied orbital pseudotumor (OP). Methods and Materials: Twenty patients (26 affected orbits) with OP were treated with RT between January 2002 and December 2011. All patients underwent biopsy with histopathologic exclusion of other disease processes. Sixteen patients (80%) were treated with intensity modulated RT, 3 (15%) with opposed lateral beams, and 1 (5%) with electrons. Median RT dose was 27 Gy (range 25.2-30.6 Gy). Response to RT was evaluated at 4 months post-RT. Partial response (PR) was defined as improvement in orbital symptoms without anmore » increase in steroid dose. Complete response (CR) 1 and CR 2 were defined as complete resolution of orbital symptoms with reduction in steroid dose (CR 1) or complete tapering of steroids (CR 2). The median follow-up period was 18.6 months (range 4-81.6 months). Results: Seventeen patients (85%) demonstrated response to RT, with 7 (35%), 1 (5%), and 9 (45%) achieving a PR, CR 1, and CR 2, respectively. Of the 17 patients who had ≥PR at 4 months post-RT, 6 (35%) experienced recurrence of symptoms. Age (>46 years vs ≤46 years, P=.04) and clinical response to RT (CR 2 vs CR 1/PR, P=.05) were significantly associated with pseudotumor recurrence. Long-term complications were seen in 7 patients (35%), including 4 with cataract formation, 1 with chronic dry eye, 1 with enophthalmos, and 1 with keratopathy. Conclusions: RT is an effective treatment for improving symptoms and tapering steroids in patients with a biopsy supported diagnosis of OP. Older age and complete response to RT were associated with a significantly reduced probability of symptom recurrence. The observed late complications may be related to RT, chronic use of steroids/immunosuppressants, medical comorbidities, or combination of factors.« less

[Efficacy of infliximab in the treatment of korean patients with crohns disease].

PubMed

Kim, Sai Hui; Yang, Suk; Kim, Kyung Jo; Kim, Eun Hee; Yoon, Soon Man; Ye, Byong Duk; Byeon, Jeong Sik; Myung, Seung Jae; Kim, Jin Ho

2009-08-01

Infliximab has been proven to be effective for refractory luminal and fistulizing Crohns disease (CD). We performed this study to demonstrate the efficacy of infliximab in Korean CD patients. Medical records of 40 CD patients who had been treated with infliximab were reviewed retrospectively. Among 40 patients, 11 (27.5%) patients were treated for refractory luminal disease, 14 (35%) for fistulizing disease, and 15 (37.5%) for both types. Clinical response rate was higher in 26 patients with refractory luminal disease (Complete response (CR), 73.1%; Partial response (PR), 23.1%) than in 29 patients with fistulizing disease (CR, 41.4%; PR, 31%) (p=0.024). The clinical response rate tended to be higher in 28 patients with external fistulas (CR, 46.4%; PR, 32.2%) than 4 patients with internal fistulas (PR, 25%; NR, 75%) (p=0.064). Among patients with external fistulas, the response rate of 8 patients with enterocutaneous fistulas (CR, 50%; PR, 12.5%) was not different from 20 patients with perianal fistulas (CR, 45%; PR, 40%). Among 20 patients with perianal fistulas, the response rate of 6 patients with perianal fistulas without a history of operation (CR, 83.3%; PR, 0%) was higher than 14 patients with perianal fistulas resistant to previous surgical treatment (CR, 28.6%; PR, 57.1%) (p=0.044). As for adverse reaction, 7 patients experienced mild infusion reaction, and 2 patients developed serious infection. Infliximab is more effective for refractory luminal disease than for fistulizing disease. In addition, clinical responses to infliximab are different according to subtypes of fistulas. These findings should be considered for the proper use of infliximab.

Predicting pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review.

PubMed

Ryan, J E; Warrier, S K; Lynch, A C; Ramsay, R G; Phillips, W A; Heriot, A G

2016-03-01

Approximately 20% of patients treated with neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer achieve a pathological complete response (pCR) while the remainder derive the benefit of improved local control and downstaging and a small proportion show a minimal response. The ability to predict which patients will benefit would allow for improved patient stratification directing therapy to those who are likely to achieve a good response, thereby avoiding ineffective treatment in those unlikely to benefit. A systematic review of the English language literature was conducted to identify pathological factors, imaging modalities and molecular factors that predict pCR following chemoradiotherapy. PubMed, MEDLINE and Cochrane Database searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation', 'tumor response'. After review of title and abstracts, 85 articles addressing the prediction of pCR were selected. Clear methods to predict pCR before chemoradiotherapy have not been defined. Clinical and radiological features of the primary cancer have limited ability to predict response. Molecular profiling holds the greatest potential to predict pCR but adoption of this technology will require greater concordance between cohorts for the biomarkers currently under investigation. At present no robust markers of the prediction of pCR have been identified and the topic remains an area for future research. This review critically evaluates existing literature providing an overview of the methods currently available to predict pCR to nCRT for locally advanced rectal cancer. The review also provides a comprehensive comparison of the accuracy of each modality. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

Practical methods for dealing with 'not applicable' item responses in the AMC Linear Disability Score project

PubMed Central

Holman, Rebecca; Glas, Cees AW; Lindeboom, Robert; Zwinderman, Aeilko H; de Haan, Rob J

2004-01-01

Background Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a 'not applicable' category to items included in the AMC Linear Disability Score (ALDS) project item bank. Methods The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. Results The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. The estimates obtained using the cold deck imputation method were substantially different. Conclusions The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used. PMID:15200681

Relationship between Item Responses of Negative Affect Items and the Distribution of the Sum of the Item Scores in the General Population

PubMed Central

Kawasaki, Yohei; Ide, Kazuki; Akutagawa, Maiko; Yamada, Hiroshi; Furukawa, Toshiaki A.; Ono, Yutaka

2016-01-01

Background Several studies have shown that total depressive symptom scores in the general population approximate an exponential pattern, except for the lower end of the distribution. The Center for Epidemiologic Studies Depression Scale (CES-D) consists of 20 items, each of which may take on four scores: “rarely,” “some,” “occasionally,” and “most of the time.” Recently, we reported that the item responses for 16 negative affect items commonly exhibit exponential patterns, except for the level of “rarely,” leading us to hypothesize that the item responses at the level of “rarely” may be related to the non-exponential pattern typical of the lower end of the distribution. To verify this hypothesis, we investigated how the item responses contribute to the distribution of the sum of the item scores. Methods Data collected from 21,040 subjects who had completed the CES-D questionnaire as part of a Japanese national survey were analyzed. To assess the item responses of negative affect items, we used a parameter r, which denotes the ratio of “rarely” to “some” in each item response. The distributions of the sum of negative affect items in various combinations were analyzed using log-normal scales and curve fitting. Results The sum of the item scores approximated an exponential pattern regardless of the combination of items, whereas, at the lower end of the distributions, there was a clear divergence between the actual data and the predicted exponential pattern. At the lower end of the distributions, the sum of the item scores with high values of r exhibited higher scores compared to those predicted from the exponential pattern, whereas the sum of the item scores with low values of r exhibited lower scores compared to those predicted. Conclusions The distributional pattern of the sum of the item scores could be predicted from the item responses of such items. PMID:27806132

Bioremediation of chromium by the yeast Pichia guilliermondii: toxicity and accumulation of Cr (III) and Cr (VI) and the influence of riboflavin on Cr tolerance.

PubMed

Ksheminska, Helena; Jaglarz, Anita; Fedorovych, Daria; Babyak, Lyubov; Yanovych, Dmytro; Kaszycki, Pawel; Koloczek, Henryk

2003-01-01

A comparative study has been made on the sensitivity of the yeast Pichia guilliermondii to Cr (III) and Cr (VI) as well as on the Cr uptake potential at growth-inhibitory concentrations of chromium. The strains used in the study were either isolated from natural sources or obtained from a laboratory strain collection. The results show that most of the natural strains were more tolerant to chromium and were able to grow in the presence of 5 mM Cr (III) or 0.5 mM Cr (VI), that is at concentrations which substantially inhibited the growth of laboratory strains. The cellular Cr content after treatment was similar for both strain types and ranged from 1.2-4.0 mg/g d.w. and 0.4-0.9 mg/g d.w., for Cr (III) and Cr (VI) forms, respectively, however, in one case of a natural strain it reached the value of 10 mg Cr (III)/g dry mass. Natural-source strains were grouped into four groups based on the yeasts' differential response to Cr (III) and Cr (VI). Hexavalent Cr-resistant mutants of a P. giuilliermondii laboratory strain, which revealed markedly changed capabilities of chromium accumulation, were obtained by means of UV-induced mutagenesis. Cr (VI) treatment triggered oversynthesis of riboflavin and the addition of exogenous riboflavin increased P. guilliermondii resistance to both Cr (III) and Cr (VI). Electrophoretic protein profiles revealed the induction and/or suppression of several proteins in response to toxic Cr (VI) levels.

Stochastic Approximation Methods for Latent Regression Item Response Models

ERIC Educational Resources Information Center

von Davier, Matthias; Sinharay, Sandip

2010-01-01

This article presents an application of a stochastic approximation expectation maximization (EM) algorithm using a Metropolis-Hastings (MH) sampler to estimate the parameters of an item response latent regression model. Latent regression item response models are extensions of item response theory (IRT) to a latent variable model with covariates…

Hexavalent chromium induced stress and metabolic responses in hybrid willows.

PubMed

Yu, Xiao-Zhang; Gu, Ji-Dong; Huang, Shen-Zhuo

2007-04-01

Metabolic responses to hexavalent chromium (Cr(6+)) stress and the uptake and translocation of Cr(6+ )were investigated using pre-rooted hybrid willows (Salix matsudana Koidz x Salix alba L.) exposed to hydroponic solution spiked with K(2)CrO(4) at 24.0 +/- 1 degrees C for 192 h. Various physiological parameters of the plants were monitored to determine toxicity from Cr(6+ )exposure. At Cr(6+) treatments of 50% higher than that of the non-treated control plants. As Cr concentrations were increased further, a slight increase in the transpiration rate was also observed compared with the controls. Negligible difference in the chlorophyll contents in leaves between the treated and the non-treated control plants was measured, except for willows exposed to 1.05 mg Cr/l. The response of soluble proteins in leaves of willows to Cr treatments was remarkable. Cr-induced toxicity appeared in all treatments resulting in reduced activities of catalase (CAT) and peroxidase (POD) compared to the controls. Superoxide dismutases (SOD) activity in the leaf cells showed a positive increase after Cr exposure. Of all selected parameters, soluble proteins in leaves were the most sensitive to Cr(6+ )doses, showing a significant linear correlation negatively (R (2) = 0.931). Uptake of Cr(6+) by willows grown in flasks was found to increase linearly with the added Cr(6+ )(a zero order kinetics), as indicated by the high R (2) (0.9322). Recovery of Cr in different parts of plant materials varied significantly with roots being the dominant site of Cr accumulation. Although the translocation to shoots was detected, the amount of Cr translocated to shoots was considerably small. The capacity of willows to assimilate Cr(6+ )was also evaluated using detached leaves and roots in sealed glass vessels in vivo. Uptake of Cr by roots was mediated possibly through an active transport mechanism, whereas the cuticle of leaves was the major obstacle to uptake Cr from the hydroponic solution. In addition, both cysteine and ascorbic acid showed a remarkable potential to reduce Cr(6+) at a neutral pH. Results indicated that the added Cr did not cause deleterious effects on plant physiological functions over a 192-h period of exposure. Significant removal of Cr from the hydroponic solution was observed in the presence of hybrid willows. The data also suggest that phytoremediation of Cr(6+) is possible and ecologically safe due to the minor translocation of Cr to aerial tissues.

Computerized Adaptive Test (CAT) Applications and Item Response Theory Models for Polytomous Items

ERIC Educational Resources Information Center

Aybek, Eren Can; Demirtasli, R. Nukhet

2017-01-01

This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…

An Evaluation of "Intentional" Weighting of Extended-Response or Constructed-Response Items in Tests with Mixed Item Types.

ERIC Educational Resources Information Center

Ito, Kyoko; Sykes, Robert C.

This study investigated the practice of weighting a type of test item, such as constructed response, more than other types of items, such as selected response, to compute student scores for a mixed-item type of test. The study used data from statewide writing field tests in grades 3, 5, and 8 and considered two contexts, that in which a single…

Regulatory effect of dietary intake of chromium propionate on the response of monocyte-derived macrophages from Holstein cows in mid lactation.

PubMed

Garcia, M; Qu, Y; Scholte, C M; O'Connor, D; Rounds, W; Moyes, K M

2017-08-01

Chromium (Cr) has been reported to enhance immune function and improve insulin sensitivity and performance in beef and dairy cattle. However, its effect on bovine macrophage inflammatory and metabolic response is unknown. The objective of this study was to characterize the effect of dietary Cr on the inflammatory and metabolic response of polarized macrophages ex vivo. Twelve primiparous and 16 multiparous healthy Holstein cows in mid lactation (143 ± 37 d in milk) were enrolled in this study. Cows were fed a common total mixed ration once per day that was top-dressed with 200 g of ground corn containing 1 of 2 dietary treatments: control (CTL, no Cr supplementation) or Cr propionate (CrP, 8 mg of Cr/cow per day) for 35 d. At d 1, 17, and 35 of treatment, blood monocytes were isolated and cultured to obtain 3 monocyte-derived macrophage (MDM) phenotypes: M0 (non-polarized), M1 (pro-inflammatory; IFN-γ polarized) and M2 (anti-inflammatory; IL-4 polarized). The experiment was set in a randomized complete block design. Neither dry matter intake nor milk yield was affected by treatment. Plasma concentrations of metabolites and the metabolic and inflammatory response of MDM in spent media were not affected by treatment. Neither the whole blood cell population nor the specific proportion of leukocytes was affected by the main effect of treatment. However, we did observe a trend for fewer circulating neutrophils in cows fed CrP than in cows fed CTL for 35 d, which may be partly attributable to a greater influx of neutrophils into peripheral tissues, a reduced pro-inflammatory response during disease, or both; this warrants future study. Expression of IGFI was increased in MDM-M0, and expression of CXCL11 tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL. Expression of SLC2A3 also tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL at 17 d. Our results suggest that CrP has minimal effect on the inflammatory and metabolic response of MDM for Holstein dairy cows in mid lactation. Future studies are warranted to evaluate the differential regulation of Cr on the inflammatory and metabolic response of leukocytes from dairy cows at different stages of lactation and parity. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

On the mechanism of Cr (VI)-induced carcinogenesis: dose dependence of uptake and cellular responses.

PubMed

Liu, K; Husler, J; Ye, J; Leonard, S S; Cutler, D; Chen, F; Wang, S; Zhang, Z; Ding, M; Wang, L; Shi, X

2001-06-01

Cr (VI) compounds are widely used industrial chemicals and are recognized human carcinogens. The mechanisms of carcinogenesis associated with these compounds remain to be investigated. The present study focused on dose-dependence of Cr (VI)-induced uptake and cellular responses. The results show that Cr (VI) is able to enter the cells (human lung epithelial cell line A549) at low concentration (< 10 microM) and that the Cr (VI) uptake appears to be a combination of saturable transport and passive diffusion. Electron spin resonance (ESR) trapping measurements showed that upon stimulation with Cr (VI), A549 cells were able to generate reactive oxygen species (ROS). The amount of ROS generated depended on the Cr (VI) concentration. ROS generation involved NADPH-dependent flavoenzymes. Cr (VI) affected the following cellular parameters in a dose-dependent manner, (a) activation of nuclear transcription factors NF-kappaB, and p53, (b) DNA damage, (c) induction of cell apoptosis, and (d) inhibition of cell proliferation. The activation of transcription factors was assessed by electrophoretic mobility shift assay and western blot analysis, DNA damage by single cell gel electrophoresis assay, cell apoptosis by DNA fragmentation assay, and cell proliferation by a non-radioactive ELISA kit. At the concentration range used in the present study, no thresholds were found in all of these cell responses to Cr (VI). The results may guide further research to better understand and evaluate the risk of Cr (VI)-induced carcinogenesis at low levels of exposure.

A Comparison of Linking and Concurrent Calibration under the Graded Response Model.

ERIC Educational Resources Information Center

Kim, Seock-Ho; Cohen, Allan S.

Applications of item response theory to practical testing problems including equating, differential item functioning, and computerized adaptive testing, require that item parameter estimates be placed onto a common metric. In this study, two methods for developing a common metric for the graded response model under item response theory were…

Writing, Evaluating and Assessing Data Response Items in Economics.

ERIC Educational Resources Information Center

Trotman-Dickenson, D. I.

1989-01-01

Describes some of the problems in writing data response items in economics for use by A Level and General Certificate of Secondary Education (GCSE) students. Examines the experience of two series of workshops on writing items, evaluating them and assessing responses from schools. Offers suggestions for producing packages of data response items as…

Item Response Modeling with Sum Scores

ERIC Educational Resources Information Center

Johnson, Timothy R.

2013-01-01

One of the distinctions between classical test theory and item response theory is that the former focuses on sum scores and their relationship to true scores, whereas the latter concerns item responses and their relationship to latent scores. Although item response theory is often viewed as the richer of the two theories, sum scores are still…

Critical analysis of the stringent complete response in multiple myeloma: contribution of sFLC and bone marrow clonality

PubMed Central

Paiva, Bruno; López-Anglada, Lucía; Mateos, María-Victoria; Cedena, Teresa; Vidríales, María-Belén; Sáez-Gómez, María Auxiliadora; Contreras, Teresa; Oriol, Albert; Rapado, Inmaculada; Teruel, Ana-Isabel; Cordón, Lourdes; Blanchard, María Jesús; Bengoechea, Enrique; Palomera, Luis; de Arriba, Felipe; Cueto-Felgueroso, Cecilia; Orfao, Alberto; Bladé, Joan; San Miguel, Jesús F.; Lahuerta, Juan José

2015-01-01

Stringent complete response (sCR) criteria are used in multiple myeloma as a deeper response category compared with CR, but prospective validation is lacking, it is not always clear how evaluation of clonality is performed, and is it not known what the relative clinical influence is of the serum free light chain ratio (sFLCr) and bone marrow (BM) clonality to define more sCR. To clarify this controversy, we focused on 94 patients that reached CR, of which 69 (73%) also fulfilled the sCR criteria. Patients with sCR displayed slightly longer time to progression (median, 62 vs 53 months, respectively; P = .31). On analyzing this contribution to the prognosis of sFLCr or clonality, it was found that the sFLCr does not identify patients in CR at distinct risk; by contrast, low-sensitive multiparametric flow cytometry (MFC) immunophenotyping (2 colors), which is equivalent to immunohistochemistry, identifies a small number of patients (5 cases) with high residual tumor burden and dismal outcome; nevertheless, using traditional 4-color MFC, persistent clonal BM disease was detectable in 36% of patients, who, compared with minimal residual disease-negative cases, had a significantly inferior outcome. These results show that the current definition of sCR should be revised. PMID:26089396

A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

ERIC Educational Resources Information Center

Polak, Marike; De Rooij, Mark; Heiser, Willem J.

2012-01-01

In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) "criterion…

Effect of NiFeCr seed and capping layers on exchange bias and planar Hall voltage response of NiFe/Au/IrMn trilayer structures

NASA Astrophysics Data System (ADS)

Talantsev, Artem; Elzwawy, Amir; Kim, CheolGi

2018-05-01

Thin films and cross junctions, based on NiFe/Au/IrMn structures, were grown on Ta and NiFeCr seed layers by magnetron sputtering. The effects of substitution of Ta with NiFeCr in seed and capping layers on an exchange bias field are studied. A threefold improvement of the exchange bias value in the structures, grown with NiFeCr seed and capping layers, is demonstrated. The reasons for this effect are discussed. Formation of clusters in the NiFeCr capping layer is proved by atomic force microscopy technique. Ta replacement on NiFeCr in the capping layer results in the enhancement of magnetoresistive response and a reduction of noise.

Prevalence of responsible hospitality policies in licensed premises that are associated with alcohol-related harm.

PubMed

Daly, Justine B; Campbell, Elizabeth M; Wiggers, John H; Considine, Robyn J

2002-06-01

This study aimed to determine the prevalence of responsible hospitality policies in a group of licensed premises associated with alcohol-related harm. During March 1999, 108 licensed premises with one or more police-identified alcohol-related incidents in the previous 3 months received a visit from a police officer. A 30-item audit checklist was used to determine the responsible hospitality policies being undertaken by each premises within eight policy domains: display required signage (three items); responsible host practices to prevent intoxication and under-age drinking (five items); written policies and guidelines for responsible service (three items); discouraging inappropriate promotions (three items); safe transport (two items); responsible management issues (seven items); physical environment (three items) and entry conditions (four items). No premises were undertaking all 30 items. Eighty per cent of the premises were undertaking 20 of the 30 items. All premises were undertaking at least 17 of the items. The proportion of premises undertaking individual items ranged from 16% to 100%. Premises were less likely to report having and providing written responsible hospitality documentation to staff, using door charges and having entry/re-entry rules. Significant differences between rural and urban premises were evident for four policies. Clubs were significantly more likely than hotels to have a written responsible service of alcohol policy and to clearly display codes of dress and conditions of entry. This study provides an indication of the extent and nature of responsible hospitality policies in a sample of licensed premises that are associated with a broad range of alcohol related harms. The finding that a large majority of such premises appear to adopt responsible hospitality policies suggests a need to assess the validity and reliability of tools used in the routine assessment of such policies, and of the potential for harm from licensed premises.

Item Response Data Analysis Using Stata Item Response Theory Package

ERIC Educational Resources Information Center

Yang, Ji Seung; Zheng, Xiaying

2018-01-01

The purpose of this article is to introduce and review the capability and performance of the Stata item response theory (IRT) package that is available from Stata v.14, 2015. Using a simulated data set and a publicly available item response data set extracted from Programme of International Student Assessment, we review the IRT package from…

Item Response Models for Local Dependence among Multiple Ratings

ERIC Educational Resources Information Center

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

2014-01-01

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

Item response theory - A first approach

NASA Astrophysics Data System (ADS)

Nunes, Sandra; Oliveira, Teresa; Oliveira, Amílcar

2017-07-01

The Item Response Theory (IRT) has become one of the most popular scoring frameworks for measurement data, frequently used in computerized adaptive testing, cognitively diagnostic assessment and test equating. According to Andrade et al. (2000), IRT can be defined as a set of mathematical models (Item Response Models - IRM) constructed to represent the probability of an individual giving the right answer to an item of a particular test. The number of Item Responsible Models available to measurement analysis has increased considerably in the last fifteen years due to increasing computer power and due to a demand for accuracy and more meaningful inferences grounded in complex data. The developments in modeling with Item Response Theory were related with developments in estimation theory, most remarkably Bayesian estimation with Markov chain Monte Carlo algorithms (Patz & Junker, 1999). The popularity of Item Response Theory has also implied numerous overviews in books and journals, and many connections between IRT and other statistical estimation procedures, such as factor analysis and structural equation modeling, have been made repeatedly (Van der Lindem & Hambleton, 1997). As stated before the Item Response Theory covers a variety of measurement models, ranging from basic one-dimensional models for dichotomously and polytomously scored items and their multidimensional analogues to models that incorporate information about cognitive sub-processes which influence the overall item response process. The aim of this work is to introduce the main concepts associated with one-dimensional models of Item Response Theory, to specify the logistic models with one, two and three parameters, to discuss some properties of these models and to present the main estimation procedures.

Hypoxia decreases creatine uptake in cardiomyocytes, while creatine supplementation enhances HIF activation.

PubMed

Santacruz, Lucia; Arciniegas, Antonio Jose Luis; Darrabie, Marcus; Mantilla, Jose G; Baron, Rebecca M; Bowles, Dawn E; Mishra, Rajashree; Jacobs, Danny O

2017-08-01

Creatine (Cr), phosphocreatine (PCr), and creatine kinases (CK) comprise an energy shuttle linking ATP production in mitochondria with cellular consumption sites. Myocytes cannot synthesize Cr: these cells depend on uptake across the cell membrane by a specialized creatine transporter (CrT) to maintain intracellular Cr levels. Hypoxia interferes with energy metabolism, including the activity of the creatine energy shuttle, and therefore affects intracellular ATP and PCr levels. Here, we report that exposing cultured cardiomyocytes to low oxygen levels rapidly diminishes Cr transport by decreasing V max and K m Pharmacological activation of AMP-activated kinase (AMPK) abrogated the reduction in Cr transport caused by hypoxia. Cr supplementation increases ATP and PCr content in cardiomyocytes subjected to hypoxia, while also significantly augmenting the cellular adaptive response to hypoxia mediated by HIF-1 activation. Our results indicate that: (1) hypoxia reduces Cr transport in cardiomyocytes in culture, (2) the cytoprotective effects of Cr supplementation are related to enhanced adaptive physiological responses to hypoxia mediated by HIF-1, and (3) Cr supplementation increases the cellular ATP and PCr content in RNCMs exposed to hypoxia. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

The impact of physical training on endothelial function in myocardial infarction survivors: pilot study.

PubMed

Peller, Michał; Balsam, Paweł; Główczyńska, Renata; Ossoliński, Krzysztof; Gilarowska, Anna; Kołtowski, Łukasz; Grabowski, Marcin; Filipiak, Krzysztof J; Opolski, Grzegorz

Endothelial dysfunction (ED) may indirectly influence the outcome of patients with coronary artery disease. To assess the influence of cardiac rehabilitation (CR) on endothelial function in patients after ST-segment elevation myocardial infarction (STEMI). Twenty-nine patients scheduled for CR were included in the study. CR began at least four weeks after STEMI and consisted of 12 or 24 training sessions. Endothelial function assessment was performed before and after CR, using reactive hyperaemia peripheral arterial tonometry. Before the CR, ED was diagnosed in 16 of 29 (55.2%) patients. A total of 25 patients had two assessments of endothelial function: before and after CR. In univariate analysis the factors of negative response of endothelial function to CR were: higher baseline hyperaemia index (lnRHI) (odds ratio [OR] for positive response to CR 0.01; 95% confidence interval [CI] 0.00-0.33; p = 0.01) and higher peak serum troponin I level during index hospitalisation (OR 0.97; 95% CI 0.94-1.00; p = 0.04). The independent, negative predictor of response to CR was lnRHI (OR 0.01; 95% CI 0.01-0.16; p = 0.03). Patients training for 24 sessions (n = 16) had similar lnRHI changes to those of patients training for 12 sessions (n = 9); [0.16 (-0.06)-0.30 vs. 0.10 (0.05-0.15); p = 0.44, respectively]. ED is a frequent abnormality in STEMI survivors. Despite the lack of statistically significant improvement of endothelial function after CR in the analysed group of patients, some factors can influence the efficacy of this type of physical activity. The best effect of CR on endothelial function was observed in patients with baseline ED.

Prolonged Particulate Hexavalent Chromium Exposure Suppresses Homologous Recombination Repair in Human Lung Cells

PubMed Central

Browning, Cynthia L.; Qin, Qin; Kelly, Deborah F.; Prakash, Rohit; Vanoli, Fabio; Jasin, Maria

2016-01-01

Abstract Genomic instability is one of the primary models of carcinogenesis and a feature of almost all cancers. Homologous recombination (HR) repair protects against genomic instability by maintaining high genomic fidelity during the repair of DNA double strand breaks. The defining step of HR repair is the formation of the Rad51 nucleofilament, which facilitates the search for a homologous sequence and invasion of the template DNA strand. Particulate hexavalent chromium (Cr(VI)), a human lung carcinogen, induces DNA double strand breaks and chromosome instability. Since the loss of HR repair increases Cr(VI)-induced chromosome instability, we investigated the effect of extended Cr(VI) exposure on HR repair. We show acute (24 h) Cr(VI) exposure induces a normal HR repair response. In contrast, prolonged (120 h) exposure to particulate Cr(VI) inhibited HR repair and Rad51 nucleofilament formation. Prolonged Cr(VI) exposure had a profound effect on Rad51, evidenced by reduced protein levels and Rad51 mislocalization to the cytoplasm. The response of proteins involved in Rad51 nuclear import and nucleofilament formation displayed varying responses to prolonged Cr(VI) exposure. BRCA2 formed nuclear foci after prolonged Cr(VI) exposure, while Rad51C foci formation was suppressed. These results suggest that particulate Cr(VI), a major chemical carcinogen, inhibits HR repair by targeting Rad51, causing DNA double strand breaks to be repaired by a low fidelity, Rad51-independent repair pathway. These results further enhance our understanding of the underlying mechanism of Cr(VI)-induced chromosome instability and thus, carcinogenesis. PMID:27449664

A Multidimensional Ideal Point Item Response Theory Model for Binary Data

ERIC Educational Resources Information Center

Maydeu-Olivares, Albert; Hernandez, Adolfo; McDonald, Roderick P.

2006-01-01

We introduce a multidimensional item response theory (IRT) model for binary data based on a proximity response mechanism. Under the model, a respondent at the mode of the item response function (IRF) endorses the item with probability one. The mode of the IRF is the ideal point, or in the multidimensional case, an ideal hyperplane. The model…

Magnons and magnetodielectric effects in CoCr2O4 : Raman scattering studies

NASA Astrophysics Data System (ADS)

Sethi, A.; Byrum, T.; McAuliffe, R. D.; Gleason, S. L.; Slimak, J. E.; Shoemaker, D. P.; Cooper, S. L.

2017-05-01

Magnetoelectric materials have generated wide technological and scientific interest because of the rich phenomena these materials exhibit, including the coexistence of magnetic and ferroelectric orders, magnetodielectric behavior, and exotic hybrid excitations such as electromagnons. The multiferroic spinel material CoCr2O4 is a particularly interesting example of a multiferroic material, because evidence for magnetoelectric behavior in the ferrimagnetic phase seems to conflict with traditional noncollinear-spin-driven mechanisms for inducing a macroscopic polarization. With the overall goal of clarifying the magnetodielectric behavior previously reported below TC in CoCr2O4 , in this paper we report an inelastic light scattering study of the magnon and phonon spectrum of CoCr2O4 as simultaneous functions of temperature, pressure, and magnetic field. Below the Curie temperature (TC=94 K ) of CoCr2O4 we observe a ω ˜16 cm-1 q =0 magnon having T1g-symmetry, which has the transformation properties of an axial vector. The anomalously large Raman intensity of the T1g-symmetry magnon is characteristic of materials with a large magneto-optical response and likely arises from large magnetic fluctuations that strongly modulate the dielectric response in CoCr2O4 . The Raman susceptibility of the T1g-symmetry magnon exhibits a strong magnetic-field dependence that is consistent with the magnetodielectric response observed in CoCr2O4 , suggesting that magnetodielectric behavior in CoCr2O4 primarily arises from the field-dependent suppression of magnetic fluctuations that are strongly coupled to long-wavelength phonons. Increasing the magnetic anisotropy in CoCr2O4 with applied pressure decreases the magnetic-field dependence of the T1g-symmetry magnon Raman susceptibility, suggesting that strain can be used to control the magnetodielectric response in CoCr2O4 .

Low Estrogen Receptor (ER)-Positive Breast Cancer and Neoadjuvant Systemic Chemotherapy: Is Response Similar to Typical ER-Positive or ER-Negative Disease?

PubMed

Landmann, Alessandra; Farrugia, Daniel J; Zhu, Li; Diego, Emilia J; Johnson, Ronald R; Soran, Atilla; Dabbs, David J; Clark, Beth Z; Puhalla, Shannon L; Jankowitz, Rachel C; Brufsky, Adam M; Ahrendt, Gretchen M; McAuliffe, Priscilla F; Bhargava, Rohit

2018-05-08

Pathologic complete response (pCR) rate after neoadjuvant chemotherapy was compared between 141 estrogen receptor (ER)-negative (43%), 41 low ER+ (13%), 47 moderate ER+ (14%), and 98 high ER+ (30%) tumors. Human epidermal growth factor receptor 2-positive cases, cases without semiquantitative ER score, and patients treated with neoadjuvant endocrine therapy alone were excluded. The pCR rate of low ER+ tumors was similar to the pCR rate of ER- tumors (37% and 26% for low ER and ER- respectively, P = .1722) but significantly different from the pCR rate of moderately ER+ (11%, P = .0049) and high ER+ tumors (4%, P < .0001). Patients with pCR had an excellent prognosis regardless of the ER status. In patients with residual disease (no pCR), the recurrence and death rate were higher in ER- and low ER+ cases compared with moderate and high ER+ cases. Low ER+ breast cancers are biologically similar to ER- tumors. Semiquantitative ER H-score is an important determinant of response to neoadjuvant chemotherapy.

RNA Disruption and Drug Response in Breast Cancer Primary Systemic Therapy.

PubMed

Pritzker, Kenneth; Pritzker, Laura; Generali, Daniele; Bottini, Alberto; Cappelletti, Maria Rosa; Guo, Baoqing; Parissenti, Amadeo; Trudeau, Maureen

2015-05-01

As there is now evidence that switching clinical nonresponders early in primary systemic therapy to alternate treatment regimens can enhance survival in some breast cancer patients, the need for a robust intermediate endpoint that can guide treatment response across all tumor subtypes is urgent. Recently, chemotherapy drugs have been shown to induce a decrease in RNA quality in tumor cells from breast cancer biopsies in some patients at midtherapy, and that this has been associated with subsequent achievement of pathological complete response (pCR). The decrease in RNA quality has been shown to be associated with RNA disruption; aberrant RNA bands visualized by RNA electrophoresis have been associated with subsequent tumor cell death. The objectives of these studies are to show that a new assay based on induction of RNA disruption in tumor cells by chemotherapy can stratify at midtherapy, pCR responders from non-pCR responders irrespective of clinical response and to present early evidence that clinically useful RNA disruption can be detected as early as 14 days after initiation of treatment. RNA disruption in tumor cells was quantified by analysis of the RNA electrophoresis banding pattern and expressed as an RNA disruption index (RDI). To develop the RNA disruption assay (RDA), RDI was correlated with clinical outcome (pCR) from the NCIC-CTG MA.22 breast cancer clinical trial (ClinicalTrials.gov NCT00066443). RDA Zones were established by stratifying patients using RDI values into Zone 1, Zone 2, and Zone 3. Zone 3 included seven out of eight pCR responders, whereas Zone 1 contained no pCR responders. An intermediate zone (Zone 2) was established which contained one pCR. Subsequently, to determine early drug response, RNA disruption was examined by RDI after 14 days exposure to trastuzumab, zoledronic acid, or letrozole + cyclophosphamide ± sorafenib therapy. In MA.22, RDA stratified 23 of 85 patients in Zone 1 as pCR nonresponders, 24 patients in Zone 2, an intermediate zone, and 38 patients in Zone 3, pCR responders and non-pCR patients who share RDI comparable to those achieving pCR. In the early response studies, after 14 days exposure to chemotherapy, some RNA disruption as measured by RDI elevation could be detected in 3/12 trastuzumab, 7/15 zoledronic acid, 5/29 letrozole + cyclophosphamide, and 5/23 letrozole + cyclophosphamide + sorafenib patients. RDA is a novel intermediate endpoint that has promise for clinical utility for breast cancers early in response-guided primary systemic therapy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Association between response rates and survival outcomes in patients with newly diagnosed multiple myeloma. A systematic review and meta-regression analysis.

PubMed

Mainou, Maria; Madenidou, Anastasia-Vasiliki; Liakos, Aris; Paschos, Paschalis; Karagiannis, Thomas; Bekiari, Eleni; Vlachaki, Efthymia; Wang, Zhen; Murad, Mohammad Hassan; Kumar, Shaji; Tsapas, Apostolos

2017-06-01

We performed a systematic review and meta-regression analysis of randomized control trials to investigate the association between response to initial treatment and survival outcomes in patients with newly diagnosed multiple myeloma (MM). Response outcomes included complete response (CR) and the combined outcome of CR or very good partial response (VGPR), while survival outcomes were overall survival (OS) and progression-free survival (PFS). We used random-effect meta-regression models and conducted sensitivity analyses based on definition of CR and study quality. Seventy-two trials were included in the systematic review, 63 of which contributed data in meta-regression analyses. There was no association between OS and CR in patients without autologous stem cell transplant (ASCT) (regression coefficient: .02, 95% confidence interval [CI] -0.06, 0.10), in patients undergoing ASCT (-.11, 95% CI -0.44, 0.22) and in trials comparing ASCT with non-ASCT patients (.04, 95% CI -0.29, 0.38). Similarly, OS did not correlate with the combined metric of CR or VGPR, and no association was evident between response outcomes and PFS. Sensitivity analyses yielded similar results. This meta-regression analysis suggests that there is no association between conventional response outcomes and survival in patients with newly diagnosed MM. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Critical analysis of the stringent complete response in multiple myeloma: contribution of sFLC and bone marrow clonality.

PubMed

Martínez-López, Joaquín; Paiva, Bruno; López-Anglada, Lucía; Mateos, María-Victoria; Cedena, Teresa; Vidríales, María-Belén; Sáez-Gómez, María Auxiliadora; Contreras, Teresa; Oriol, Albert; Rapado, Inmaculada; Teruel, Ana-Isabel; Cordón, Lourdes; Blanchard, María Jesús; Bengoechea, Enrique; Palomera, Luis; de Arriba, Felipe; Cueto-Felgueroso, Cecilia; Orfao, Alberto; Bladé, Joan; San Miguel, Jesús F; Lahuerta, Juan José

2015-08-13

Stringent complete response (sCR) criteria are used in multiple myeloma as a deeper response category compared with CR, but prospective validation is lacking, it is not always clear how evaluation of clonality is performed, and is it not known what the relative clinical influence is of the serum free light chain ratio (sFLCr) and bone marrow (BM) clonality to define more sCR. To clarify this controversy, we focused on 94 patients that reached CR, of which 69 (73%) also fulfilled the sCR criteria. Patients with sCR displayed slightly longer time to progression (median, 62 vs 53 months, respectively; P = .31). On analyzing this contribution to the prognosis of sFLCr or clonality, it was found that the sFLCr does not identify patients in CR at distinct risk; by contrast, low-sensitive multiparametric flow cytometry (MFC) immunophenotyping (2 colors), which is equivalent to immunohistochemistry, identifies a small number of patients (5 cases) with high residual tumor burden and dismal outcome; nevertheless, using traditional 4-color MFC, persistent clonal BM disease was detectable in 36% of patients, who, compared with minimal residual disease-negative cases, had a significantly inferior outcome. These results show that the current definition of sCR should be revised. © 2015 by The American Society of Hematology.

Cr2O3 nanoparticle-functionalized WO3 nanorods for ethanol gas sensors

NASA Astrophysics Data System (ADS)

Choi, Seungbok; Bonyani, Maryam; Sun, Gun-Joo; Lee, Jae Kyung; Hyun, Soong Keun; Lee, Chongmu

2018-02-01

Pristine WO3 nanorods and Cr2O3-functionalized WO3 nanorods were synthesized by the thermal evaporation of WO3 powder in an oxidizing atmosphere, followed by spin-coating of the nanowires with Cr2O3 nanoparticles and thermal annealing in an oxidizing atmosphere. Scanning electron microscopy was used to examine the morphological features and X-ray diffraction was used to study the crystallinity and phase formation of the synthesized nanorods. Gas sensing tests were performed at different temperatures in the presence of test gases (ethanol, acetone, CO, benzene and toluene). The Cr2O3-functionalized WO3 nanorods sensor showed a stronger response to these gases relative to the pristine WO3 nanorod sensor. In particular, the response of the Cr2O3-functionalized WO3 nanorods sensor to 200 ppm ethanol gas was 5.58, which is approximately 4.4 times higher that of the pristine WO3 nanorods sensor. Furthermore, the Cr2O3-functionalized WO3 nanorods sensor had a shorter response and recovery time. The pristine WO3 nanorods had no selectivity toward ethanol gas, whereas the Cr2O3-functionalized WO3 nanorods sensor showed good selectivity toward ethanol. The gas sensing mechanism of the Cr2O3-functionalized WO3 nanorods sensor toward ethanol is discussed in detail.

Impact of x-ray dose on the response of CR-39 to 1–5.5 MeV alphas

DOE PAGES

Rojas-Herrera, J.; Rinderknecht, H. G.; Zylstra, A. B.; ...

2015-03-01

The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray uences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K α and K β x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those notmore » exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.« less

Summed and Weighted Summary Scores for the Medsger Disease Severity Scale Compared with the Physician's Global Assessment of Disease Severity in Systemic Sclerosis.

PubMed

Harel, Daphna; Hudson, Marie; Iliescu, Alexandra; Baron, Murray; Steele, Russell

2016-08-01

To develop a weighted summary score for the Medsger Disease Severity Scale (DSS) and to compare its measurement properties with those of a summed DSS score and a physician's global assessment (PGA) of severity score in systemic sclerosis (SSc). Data from 875 patients with SSc enrolled in a multisite observational research cohort were extracted from a central database. Item response theory was used to estimate weights for the DSS weighted score. Intraclass correlation coefficients (ICC) and convergent, discriminative, and predictive validity of the 3 summary measures in relation to patient-reported outcomes (PRO) and mortality were compared. Mean PGA was 2.69 (SD 2.16, range 0-10), mean DSS summed score was 8.60 (SD 4.02, range 0-36), and mean DSS weighted score was 8.11 (SD 4.05, range 0-36). ICC were similar for all 3 measures [PGA 6.9%, 95% credible intervals (CrI) 2.1-16.2; DSS summed score 2.5%, 95% CrI 0.4-6.7; DSS weighted score 2.0%, 95% CrI 0.1-5.6]. Convergent and discriminative validity of the 3 measures for PRO were largely similar. In Cox proportional hazards models adjusting for age and sex, the 3 measures had similar predictive ability for mortality (adjusted R(2) 13.9% for PGA, 12.3% for DSS summed score, and 10.7% DSS weighted score). The 3 summary scores appear valid and perform similarly. However, there were some concerns with the weights computed for individual DSS scales, with unexpected low weights attributed to lung, heart, and kidney, leading the PGA to be the preferred measure at this time. Further work refining the DSS could improve the measurement properties of the DSS summary scores.

A Two-Decision Model for Responses to Likert-Type Items

ERIC Educational Resources Information Center

Thissen-Roe, Anne; Thissen, David

2013-01-01

Extreme response set, the tendency to prefer the lowest or highest response option when confronted with a Likert-type response scale, can lead to misfit of item response models such as the generalized partial credit model. Recently, a series of intrinsically multidimensional item response models have been hypothesized, wherein tendency toward…

Low dose decitabine in very high risk relapsed or refractory acute myeloid leukaemia in children and young adults.

PubMed

Phillips, Christine L; Davies, Stella M; McMasters, Richard; Absalon, Michael; O'Brien, Maureen; Mo, Jun; Broun, Randall; Moscow, Jeffrey A; Smolarek, Teresa; Garzon, Ramiro; Blum, William; Schwind, Sebastian; Marcucci, Guido; Perentesis, John P

2013-05-01

Low-dose decitabine has encouraging activity and tolerability in adults with acute myeloid leukaemia (AML), but paediatric experience is lacking. We report our retrospective experience with decitabine in eight children and young adults (median age 4 years) with refractory/relapsed AML, who had failed multiple regimens or were not candidates for standard retrieval regimens due to prior toxicities. Three of eight patients (38%) had complete response (CR; 1 each of CR, CR with incomplete platelet recovery and CR with incomplete count recovery). Best responses were observed after a median of 2.5 cycles (range 1-4 cycles). Four patients received subsequent allogeneic stem cell transplant, and two remain in long-term CR. © 2013 Blackwell Publishing Ltd.

Personalised treatment for cognitive dysfunction in individuals with schizophrenia spectrum disorders.

PubMed

Medalia, Alice; Saperstein, Alice M; Hansen, Marie C; Lee, Seonjoo

2018-06-01

Cognitive deficits are a well-recognised issue for individuals diagnosed with schizophrenia spectrum disorders. Despite positive group findings for the use of cognitive remediation (CR) interventions, there are substantial individual differences in response to treatment. In addition, the aggregate CR literature reports low moderate effect sizes for cognitive and functional outcomes. Based on personalised medicine theory, this paper uses extant CR literature to examine the individual characteristics determined to predict treatment response. These characteristics, which fall into the broad categories of cognitive, psychological, and biological can be used as tailoring variables to personalise CR to an individual's unique profile. Personalisation through the use of these tailoring variables has the potential to improve the delivery of CR to maximise treatment outcomes.

Reevaluation of the Amsterdam Inventory for Auditory Disability and Handicap Using Item Response Theory.

PubMed

Boeschen Hospers, J Mirjam; Smits, Niels; Smits, Cas; Stam, Mariska; Terwee, Caroline B; Kramer, Sophia E

2016-04-01

We reevaluated the psychometric properties of the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1995) using item response theory. Item response theory describes item functioning along an ability continuum. Cross-sectional data from 2,352 adults with and without hearing impairment, ages 18-70 years, were analyzed. They completed the AIADH in the web-based prospective cohort study "Netherlands Longitudinal Study on Hearing." A graded response model was fitted to the AIADH data. Category response curves, item information curves, and the standard error as a function of self-reported hearing ability were plotted. The graded response model showed a good fit. Item information curves were most reliable for adults who reported having hearing disability and less reliable for adults with normal hearing. The standard error plot showed that self-reported hearing ability is most reliably measured for adults reporting mild up to moderate hearing disability. This is one of the few item response theory studies on audiological self-reports. All AIADH items could be hierarchically placed on the self-reported hearing ability continuum, meaning they measure the same construct. This provides a promising basis for developing a clinically useful computerized adaptive test, where item selection adapts to the hearing ability of individuals, resulting in efficient assessment of hearing disability.

Measuring the preference towards patient-centred communication with the Chinese-revised Patient-Practitioner Orientation Scale: a cross-sectional study among physicians and patients in clinical settings in Shanghai, China.

PubMed

Wang, Jie; Zou, Runyu; Fu, Hua; Qian, Haihong; Yan, Yueren; Wang, Fan

2017-09-18

To adapt the Patient-Practitioner Orientation Scale (PPOS), to a Chinese context, and explore the preference towards patient-centred communication among physicians and patients with the Chinese-revised Patient-Practitioner Orientation Scale (CR-PPOS). A cross-sectional questionnaire-based study. Clinical settings from eight medical units, including four community hospitals and four general hospitals, in Shanghai, China. 1018 participants, including 187 physicians and 831 patients, completed this study in two successive stages. Psychometric properties of the CR-PPOS and participants' score on the CR-PPOS. Compared with the original PPOS, the 11-item CR-PPOS obtained better psychometric indices. Physicians and patients scored differently on both the total CR-PPOS and its two subscales. Compared with physicians, the scores of patients were more influenced by their personal characteristics, such as age and education. The CR-PPOS is a better instrument in a Chinese context than the original translated version. The divergence in the extent to which patient-centred communication is preferred among Chinese physicians and patients should be noted. Adapting physicians' communication strategy to patients' preferences based on their personal characteristics can be a viable approach towards improving clinical efficiency. © 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.

On the Relationship Between Classical Test Theory and Item Response Theory: From One to the Other and Back.

PubMed

Raykov, Tenko; Marcoulides, George A

2016-04-01

The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete nature of the observed items. Two distinct observational equivalence approaches are outlined that render the item response models from corresponding classical test theory-based models, and can each be used to obtain the former from the latter models. Similarly, classical test theory models can be furnished using the reverse application of either of those approaches from corresponding item response models.

[Instrument to measure adherence in hypertensive patients: contribution of Item Response Theory].

PubMed

Rodrigues, Malvina Thaís Pacheco; Moreira, Thereza Maria Magalhaes; Vasconcelos, Alexandre Meira de; Andrade, Dalton Francisco de; Silva, Daniele Braz da; Barbetta, Pedro Alberto

2013-06-01

To analyze, by means of "Item Response Theory", an instrument to measure adherence to t treatment for hypertension. Analytical study with 406 hypertensive patients with associated complications seen in primary care in Fortaleza, CE, Northeastern Brazil, 2011 using "Item Response Theory". The stages were: dimensionality test, calibrating the items, processing data and creating a scale, analyzed using the gradual response model. A study of the dimensionality of the instrument was conducted by analyzing the polychoric correlation matrix and factor analysis of complete information. Multilog software was used to calibrate items and estimate the scores. Items relating to drug therapy are the most directly related to adherence while those relating to drug-free therapy need to be reworked because they have less psychometric information and low discrimination. The independence of items, the small number of levels in the scale and low explained variance in the adjustment of the models show the main weaknesses of the instrument analyzed. The "Item Response Theory" proved to be a relevant analysis technique because it evaluated respondents for adherence to treatment for hypertension, the level of difficulty of the items and their ability to discriminate between individuals with different levels of adherence, which generates a greater amount of information. The instrument analyzed is limited in measuring adherence to hypertension treatment, by analyzing the "Item Response Theory" of the item, and needs adjustment. The proper formulation of the items is important in order to accurately measure the desired latent trait.

The Consequences of Ignoring Item Parameter Drift in Longitudinal Item Response Models

ERIC Educational Resources Information Center

Lee, Wooyeol; Cho, Sun-Joo

2017-01-01

Utilizing a longitudinal item response model, this study investigated the effect of item parameter drift (IPD) on item parameters and person scores via a Monte Carlo study. Item parameter recovery was investigated for various IPD patterns in terms of bias and root mean-square error (RMSE), and percentage of time the 95% confidence interval covered…

Assessing the Item Response Theory with Covariate (IRT-C) Procedure for Ascertaining Differential Item Functioning

ERIC Educational Resources Information Center

Tay, Louis; Vermunt, Jeroen K.; Wang, Chun

2013-01-01

We evaluate the item response theory with covariates (IRT-C) procedure for assessing differential item functioning (DIF) without preknowledge of anchor items (Tay, Newman, & Vermunt, 2011). This procedure begins with a fully constrained baseline model, and candidate items are tested for uniform and/or nonuniform DIF using the Wald statistic.…

On Multidimensional Item Response Theory: A Coordinate-Free Approach. Research Report. ETS RR-07-30

ERIC Educational Resources Information Center

Antal, Tamás

2007-01-01

A coordinate-free definition of complex-structure multidimensional item response theory (MIRT) for dichotomously scored items is presented. The point of view taken emphasizes the possibilities and subtleties of understanding MIRT as a multidimensional extension of the classical unidimensional item response theory models. The main theorem of the…

Missouri Assessment Program (MAP), Spring 2000: Elementary Health/Physical Education, Released Items, Grade 5.

ERIC Educational Resources Information Center

Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

This document presents 10 released items from the Health/Physical Education Missouri Assessment Program (MAP) test given in the spring of 2000 to fifth graders. Items from the test sessions include: selected-response (multiple choice), constructed-response, and a performance event. The selected-response items consist of individual questions…

Reevaluation of the Amsterdam Inventory for Auditory Disability and Handicap Using Item Response Theory

ERIC Educational Resources Information Center

Hospers, J. Mirjam Boeschen; Smits, Niels; Smits, Cas; Stam, Mariska; Terwee, Caroline B.; Kramer, Sophia E.

2016-01-01

Purpose: We reevaluated the psychometric properties of the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1995) using item response theory. Item response theory describes item functioning along an ability continuum. Method: Cross-sectional data from 2,352 adults with and without hearing…

The Relationship of Expert-System Scored Constrained Free-Response Items to Multiple-Choice and Open-Ended Items.

ERIC Educational Resources Information Center

Bennett, Randy Elliot; And Others

1990-01-01

The relationship of an expert-system-scored constrained free-response item type to multiple-choice and free-response items was studied using data for 614 students on the College Board's Advanced Placement Computer Science (APCS) Examination. Implications for testing and the APCS test are discussed. (SLD)

Rapid and early α-fetoprotein and des-γ-carboxy prothrombin responses to initial arterial infusion chemotherapy predict treatment outcomes of advanced hepatocellular carcinoma

PubMed Central

OYAMA, KENJI; KODA, MASAHIKO; SUGIHARA, TAKAAKI; KISHINA, MANABU; MIYOSHI, KENICHI; OKAMOTO, TOSHIAKI; HODOTSUKA, MASANORI; FUJISE, YUKI; MATONO, TOMOMITSU; TOKUNAGA, SHIHO; OKAMOTO, KINYA; HOSHO, KEIKO; OKANO, JUNICHI; MURAWAKI, YOSHIKAZU

2015-01-01

The aim of the present study was to predict the effects of transarterial infusion (TAI) chemotherapy based on early changes in α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) in patients with advanced hepatocellular carcinoma (HCC). Seventy-four patients who underwent TAI with cisplatin, 5-fluorouracil, mitomycin C and epirubicin for advanced HCC were enrolled. Antitumor responses were evaluated 6 months after TAI. Rapid and early responses were defined as the ratio of AFP or DCP after 1 week and 1 month compared to baseline. A total of 5, 10, 17 and 42 patients had complete response (CR), partial response (PR), stable disease (SD) or progressive disease (PD), respectively. Early AFP response was significantly lower in the CR+PR compared to the SD+PD groups (P<0.01). The early DCP response was significantly lower in the CR+PR compared to the SD+PD. The sensitivity and specificity of rapid and early AFP responses in the CR+PR were 0.78 and 0.72, and 0.80 and 0.73, respectively, and those of rapid and early DCP responses were 0.67 and 0.65, and 0.77 and 0.71, respectively. The combination of AFP and DCP responses had higher specificity compared to AFP or DCP alone responses. Patients were divided into responder and non-responder groups to evaluate the prediction of survival outcome. Early responders of AFP, DCP and AFP+DCP, who were divided based on the cut-off values of CR+PR survived significantly longer than the non-responders (P<0.05). In conclusion, rapid or early responses of AFP and/or DCP levels 1 and 4 weeks after TAI chemotherapy helped to predict the treatment effects. PMID:26137283

Perceived freedom-responsibility covariation among Cypriot adolescents.

PubMed

Frangou, Georgia; Wilkerson, Keith; McGahan, Joseph R

2008-04-01

Participants were 67 Cypriot adolescents who responded to propositions regarding positive, negative, and noncontingent relations between freedom and responsibility. The authors framed items so that half dealt with freedom given responsibility, and the other half dealt with responsibility given freedom. Results indicated participants were more likely to endorse positive-contingency items than they were negative and noncontingency items when items were framed around freedom given responsibility. However, when items were framed around responsibility given freedom, no such differences emerged. The authors discuss results relative to cultural and sociopolitical differences and similarities between children in Cypress and participants in the United States and implications concerning the present study and previous studies regarding these constructs.

Investigation of equilibrium and kinetics of Cr(VI) adsorption by dried Bacillus cereus using response surface methodology.

PubMed

Yang, Kai; Zhang, Jing; Yang, Tao; Wang, Hongyu

2016-01-01

In this study, response surface methodology (RSM) based on three-variable-five-level central composite rotatable design was used to analyze the effects of combined and individual operating parameters (biomass dose, initial concentration of Cr(VI) and pH) on the Cr(VI) adsorption capacity of dried Bacillus cereus. A quadratic polynomial equation was obtained to predict the adsorbed Cr(VI) amount. Analysis of variance showed that the effect of biomass dose was the key factor in the removal of Cr(VI). The maximum adsorbed Cr(VI) amount (30.93 mg g(-1)) was found at 165.30 mg L(-1), 2.96, and 3.01 g L(-1) for initial Cr(VI) concentration, pH, and biosorbent dosage, respectively. The surface chemical functional groups and microstructure of unloaded and Cr(VI)-loaded dried Bacillus cereus were identified by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Besides, the results gained from these studies indicated that Langmuir isotherm and the second-order rate expression were suitable for the removal of Cr(VI) from wastewater. The results revealed RSM was an effective method for optimizing biosorption process, and dried Bacillus cereus had a remarkable performance on the removal of Cr(VI) from wastewater.

Proteomic responses of BEAS-2B cells to nontoxic and toxic chromium: Protein indicators of cytotoxicity conversion.

PubMed

Bruno, Maribel; Ross, Jeffrey; Ge, Yue

2016-12-15

Hexavalent chromium (Cr (VI)) is an environmental human carcinogen which primarily targets lungs. Among a variety of toxic mechanisms, disruption of biological pathways via translational and post-translational modifications represents a key mechanism through which Cr (VI) induces cytotoxicity and carcinogenesis. To identify those disruptions which are altered in response to cytotoxic Cr (VI) exposures, we measured and compared cytotoxicity and changes in expression and phosphorylation status of 15 critical biochemical pathway regulators in human BEAS-2B cells exposed for 48h to a non-toxic concentration (0.3μM) and a toxic concentration (1.8μM) of Cr (VI) by ELISA techniques. In addition, 43 functional proteins which may be altered in response to pathway signaling changes were identified using two dimensional electrophoresis (2-DE) and mass spectrometry. The proteins and fold changes observed in cells exposed to the non-toxic dose of Cr (VI) (0.3μM) were not necessarily the same as those found in the toxic one (1.8μM). A subset of signaling proteins that were correlated with the cytotoxic responses of human BEAS-2B cells to Cr (VI) treatments were identified. These proteins include regulators of glycolysis, glycogen synthase kinase 3 beta (GSK3β) and phosphoprotein 70 ribosomal protein s6 kinase (p70S6K), a signaling protein associated with oxidative stress and inflammation responses, JNK and metal regulatory transcription factor 1 (MTF-1), and a source of ubiquitin for signaling targeted protein degradation, polyubiquitin C (UBC). In addition, two dimensional gel electrophoresis (2-DE) was applied to identify key alterations in biochemical pathways differentiating between cytotoxic and non-cytotoxic exposures to Cr (VI), including glycolysis and gluconeogenesis, protein degradation, inflammation, and oxidative stress. Published by Elsevier Ireland Ltd.

Prolonged Particulate Hexavalent Chromium Exposure Suppresses Homologous Recombination Repair in Human Lung Cells.

PubMed

Browning, Cynthia L; Qin, Qin; Kelly, Deborah F; Prakash, Rohit; Vanoli, Fabio; Jasin, Maria; Wise, John Pierce

2016-09-01

Genomic instability is one of the primary models of carcinogenesis and a feature of almost all cancers. Homologous recombination (HR) repair protects against genomic instability by maintaining high genomic fidelity during the repair of DNA double strand breaks. The defining step of HR repair is the formation of the Rad51 nucleofilament, which facilitates the search for a homologous sequence and invasion of the template DNA strand. Particulate hexavalent chromium (Cr(VI)), a human lung carcinogen, induces DNA double strand breaks and chromosome instability. Since the loss of HR repair increases Cr(VI)-induced chromosome instability, we investigated the effect of extended Cr(VI) exposure on HR repair. We show acute (24 h) Cr(VI) exposure induces a normal HR repair response. In contrast, prolonged (120 h) exposure to particulate Cr(VI) inhibited HR repair and Rad51 nucleofilament formation. Prolonged Cr(VI) exposure had a profound effect on Rad51, evidenced by reduced protein levels and Rad51 mislocalization to the cytoplasm. The response of proteins involved in Rad51 nuclear import and nucleofilament formation displayed varying responses to prolonged Cr(VI) exposure. BRCA2 formed nuclear foci after prolonged Cr(VI) exposure, while Rad51C foci formation was suppressed. These results suggest that particulate Cr(VI), a major chemical carcinogen, inhibits HR repair by targeting Rad51, causing DNA double strand breaks to be repaired by a low fidelity, Rad51-independent repair pathway. These results further enhance our understanding of the underlying mechanism of Cr(VI)-induced chromosome instability and thus, carcinogenesis. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Gene expression profiles in paraffin-embedded core biopsy tissue predict response to chemotherapy in women with locally advanced breast cancer.

PubMed

Gianni, Luca; Zambetti, Milvia; Clark, Kim; Baker, Joffre; Cronin, Maureen; Wu, Jenny; Mariani, Gabriella; Rodriguez, Jaime; Carcangiu, Marialuisa; Watson, Drew; Valagussa, Pinuccia; Rouzier, Roman; Symmans, W Fraser; Ross, Jeffrey S; Hortobagyi, Gabriel N; Pusztai, Lajos; Shak, Steven

2005-10-10

We sought to identify gene expression markers that predict the likelihood of chemotherapy response. We also tested whether chemotherapy response is correlated with the 21-gene Recurrence Score assay that quantifies recurrence risk. Patients with locally advanced breast cancer received neoadjuvant paclitaxel and doxorubicin. RNA was extracted from the pretreatment formalin-fixed paraffin-embedded core biopsies. The expression of 384 genes was quantified using reverse transcriptase polymerase chain reaction and correlated with pathologic complete response (pCR). The performance of genes predicting for pCR was tested in patients from an independent neoadjuvant study where gene expression was obtained using DNA microarrays. Of 89 assessable patients (mean age, 49.9 years; mean tumor size, 6.4 cm), 11 (12%) had a pCR. Eighty-six genes correlated with pCR (unadjusted P < .05); pCR was more likely with higher expression of proliferation-related genes and immune-related genes, and with lower expression of estrogen receptor (ER) -related genes. In 82 independent patients treated with neoadjuvant paclitaxel and doxorubicin, DNA microarray data were available for 79 of the 86 genes. In univariate analysis, 24 genes correlated with pCR with P < .05 (false discovery, four genes) and 32 genes showed correlation with P < .1 (false discovery, eight genes). The Recurrence Score was positively associated with the likelihood of pCR (P = .005), suggesting that the patients who are at greatest recurrence risk are more likely to have chemotherapy benefit. Quantitative expression of ER-related genes, proliferation genes, and immune-related genes are strong predictors of pCR in women with locally advanced breast cancer receiving neoadjuvant anthracyclines and paclitaxel.

Dealing with Omitted and Not-Reached Items in Competence Tests: Evaluating Approaches Accounting for Missing Responses in Item Response Theory Models

ERIC Educational Resources Information Center

Pohl, Steffi; Gräfe, Linda; Rose, Norman

2014-01-01

Data from competence tests usually show a number of missing responses on test items due to both omitted and not-reached items. Different approaches for dealing with missing responses exist, and there are no clear guidelines on which of those to use. While classical approaches rely on an ignorable missing data mechanism, the most recently developed…

Cumulative Risk and Physiological Stress Responses in African American Adolescents.

PubMed

Kliewer, Wendy; Robins, Jo Lynne W

2017-07-01

To investigate associations between components of cumulative risk (CR) and physiological stress responses in African American adolescents and evaluate emotion regulation as a mediator and sex as a moderator of these associations. Cortisol and salivary alpha amylase (sAA) were collected in adolescents ( N = 205; 55% female; 12.1 ± 1.6 years at baseline) as part of a longitudinal study of stress and adjustment in families. CR was assessed at baseline and emotion regulation was assessed at baseline and 2 years later at Wave 3 (W3) using caregiver and adolescent reports. Cortisol and sAA responses to the social competence interview were assessed at W3. Repeated-measures analyses of variance predicting cortisol and controlling for time of day, adolescent age, medication usage, and pubertal status revealed significant interactions of time with both psychosocial and sociodemographic risk. In both analyses, youths with higher levels of risk showed a steeper decline in cortisol than youths with lower levels of risk. In parallel analyses predicting sAA, time interacted with psychosocial but not with sociodemographic risk. There were no interactions with sex in any of the analyses. Although CR was associated with changes in emotion regulation, there was no evidence that these changes accounted for the observed CR-stress response associations. These findings illustrate the potential importance of disentangling CR and suggest that additional work is needed to help explicate why and how CR is associated with specific physiological responses to stress.

Adsorption and desorption of hexavalent chromium in an alluvial aquifer near Telluride, Colorado

USGS Publications Warehouse

Stollenwerk, K.G.; Grove, D.B.

1985-01-01

A laboratory investigation of reactions between hexavalent chromium [Cr(VI)] and alluvium was conducted to evaluate reactions of Cr(VI) contaminating an alluvial aquifer near Telluride, CO and to determine the mechanisms responsible for these reactions. Uncontaminated alluvium and groundwater (spiked with CrO42-) from the study site were used in batch and column experiments. Results of these experiments show that Cr(VI) was adsorbed by the alluvium. Distribution coefficients from batch experiments ranged from 52 L/kg at an equilibrium CrO42- concentration of 0.4 ??mol/L to 1.7 L/kg at an equilibrium concentration of 1400 ??mol/L. The zero point of charge for the alluvium was approximately 8.3, and the alluvium had a positive net charge at the groundwater pH of 6.8. Visual and chemical evidence indicated that Fe oxide and hydroxide coatings on the alluvial particles principally were responsible for the absorption of Cr(VI). During column experiments, Cr(VI) initially was desorbed easily from the alluvium by Cr-free groundwater; however, the rate of desorption decreased rapidly, and > 60 pore volumes of groundwater were required to decrease the effluent concentration of Cr(VI) to 3 ??mol/L [drinking water standard for Cr(VI) = 1 ??mol/L]. The quantity of Cr(VI) adsorbed varied with the type and concentration of other anions in solution.

An Evolutionarily Conserved DOF-CONSTANS Module Controls Plant Photoperiodic Signaling1[OPEN

PubMed Central

2015-01-01

The response to daylength is a crucial process that evolved very early in plant evolution, entitling the early green eukaryote to predict seasonal variability and attune its physiological responses to the environment. The photoperiod responses evolved into the complex signaling pathways that govern the angiosperm floral transition today. The Chlamydomonas reinhardtii DNA-Binding with One Finger (CrDOF) gene controls transcription in a photoperiod-dependent manner, and its misexpression influences algal growth and viability. In short days, CrDOF enhances CrCO expression, a homolog of plant CONSTANS (CO), by direct binding to its promoter, while it reduces the expression of cell division genes in long days independently of CrCO. In Arabidopsis (Arabidopsis thaliana), transgenic plants overexpressing CrDOF show floral delay and reduced expression of the photoperiodic genes CO and FLOWERING LOCUS T. The conservation of the DOF-CO module during plant evolution could be an important clue to understanding diversification by the inheritance of conserved gene toolkits in key developmental programs. PMID:25897001

The effect of elevated blood cortisol levels on the extinction of a conditioned stress response in rainbow trout.

PubMed

Barreto, R E; Volpato, G L; Pottinger, T G

2006-09-01

Following previously published observations that a conditioned response (CR) was lost more quickly by rainbow trout (Oncorhynchus mykiss) exhibiting a high responsiveness to stressors than by low responding individuals this study was designed to investigate the effects of exogenous cortisol on the retention of a CR in unselected rainbow trout. Fish held in isolation were conditioned over a 10-day period by pairing an innocuous signal (conditioned stimulus, CS: a water jet played on the surface of the tank water) with a mild stressor (unconditioned stimulus, US: 30 min of confinement). This resulted in a brief elevation of plasma cortisol levels (the CR) when the fish was exposed to the CS only. The effect of exogenous cortisol on the retention of the CR was evaluated by comparing the performance of fish that received cortisol-containing slow-release intraperitoneal implants, with fish receiving vehicle-only implants. Retention of the CR was assessed at intervals up to 35 days after conditioning ceased. The CR was considered to be evident when 30 min following presentation of the CS, mean plasma cortisol levels were significantly higher in conditioned than untrained fish. On day 1 both cortisol-implanted and vehicle-implanted conditioned fish exhibited a CR. However, from day 5 onwards the CR was observed only in the vehicle-implanted and conditioned group. This finding indicates that administration of cortisol accelerated the extinction of the CR in the cortisol-implanted fish, suggesting that elevated plasma cortisol levels can impair memory processes in rainbow trout.

Identification of rice genes associated with cosmic-ray response via co-expression gene network analysis.

PubMed

Hwang, Sun-Goo; Kim, Dong Sub; Hwang, Jung Eun; Han, A-Reum; Jang, Cheol Seong

2014-05-15

In order to better understand the biological systems that are affected in response to cosmic ray (CR), we conducted weighted gene co-expression network analysis using the module detection method. By using the Pearson's correlation coefficient (PCC) value, we evaluated complex gene-gene functional interactions between 680 CR-responsive probes from integrated microarray data sets, which included large-scale transcriptional profiling of 1000 microarray samples. These probes were divided into 6 distinct modules that contained 20 enriched gene ontology (GO) functions, such as oxidoreductase activity, hydrolase activity, and response to stimulus and stress. In particular, modules 1 and 2 commonly showed enriched annotation categories such as oxidoreductase activity, including enriched cis-regulatory elements known as ROS-specific regulators. These results suggest that the ROS-mediated irradiation response pathway is affected by CR in modules 1 and 2. We found 243 ionizing radiation (IR)-responsive probes that exhibited similarities in expression patterns in various irradiation microarray data sets. The expression patterns of 6 randomly selected IR-responsive genes were evaluated by quantitative reverse transcription polymerase chain reaction following treatment with CR, gamma rays (GR), and ion beam (IB); similar patterns were observed among these genes under these 3 treatments. Moreover, we constructed subnetworks of IR-responsive genes and evaluated the expression levels of their neighboring genes following GR treatment; similar patterns were observed among them. These results of network-based analyses might provide a clue to understanding the complex biological system related to the CR response in plants. Copyright © 2014 Elsevier B.V. All rights reserved.

Systematic review of FDG-PET prediction of complete pathological response and survival in rectal cancer.

PubMed

Memon, Sameer; Lynch, A Craig; Akhurst, Timothy; Ngan, Samuel Y; Warrier, Satish K; Michael, Michael; Heriot, Alexander G

2014-10-01

Advances in the management of rectal cancer have resulted in an increased application of multimodal therapy with the aim of tailoring therapy to individual patients. Complete pathological response (pCR) is associated with improved survival and may be potentially managed without radical surgical resection. Over the last decade, there has been increasing interest in the ability of functional imaging to predict complete response to treatment. The aim of this review was to assess the role of (18)F-flurordeoxyglucose positron emission tomography (FDG-PET) in prediction of pCR and prognosis in resectable locally advanced rectal cancer. A search of the MEDLINE and Embase databases was conducted, and a systematic review of the literature investigating positron emission tomography (PET) in the prediction of pCR and survival in rectal cancer was performed. Seventeen series assessing PET prediction of pCR were included in the review. Seven series assessed postchemoradiation SUVmax, which was significantly different between response groups in all six studies that assessed this. Nine series assessed the response index (RI) for SUVmax, which was significantly different between response groups in seven series. Thirteen studies investigated PET response for prediction of survival. Metabolic complete response assessed by SUV2max or visual response and RISUVmax showed strong associations with disease-free survival (DFS) and overall survival (OS). SUV2max and RISUVmax appear to be useful FDG-PET markers for prediction of pCR and these parameters also show strong associations with DFS and OS. FDG-PET may have a role in outcome prediction in patients with advanced rectal cancer.

A Comparison of Limited-Information and Full-Information Methods in M"plus" for Estimating Item Response Theory Parameters for Nonnormal Populations

ERIC Educational Resources Information Center

DeMars, Christine E.

2012-01-01

In structural equation modeling software, either limited-information (bivariate proportions) or full-information item parameter estimation routines could be used for the 2-parameter item response theory (IRT) model. Limited-information methods assume the continuous variable underlying an item response is normally distributed. For skewed and…

Estimation of Item Response Theory Parameters in the Presence of Missing Data

ERIC Educational Resources Information Center

Finch, Holmes

2008-01-01

Missing data are a common problem in a variety of measurement settings, including responses to items on both cognitive and affective assessments. Researchers have shown that such missing data may create problems in the estimation of item difficulty parameters in the Item Response Theory (IRT) context, particularly if they are ignored. At the same…

Examination of Different Item Response Theory Models on Tests Composed of Testlets

ERIC Educational Resources Information Center

Kogar, Esin Yilmaz; Kelecioglu, Hülya

2017-01-01

The purpose of this research is to first estimate the item and ability parameters and the standard error values related to those parameters obtained from Unidimensional Item Response Theory (UIRT), bifactor (BIF) and Testlet Response Theory models (TRT) in the tests including testlets, when the number of testlets, number of independent items, and…

A Semiparametric Model for Jointly Analyzing Response Times and Accuracy in Computerized Testing

ERIC Educational Resources Information Center

Wang, Chun; Fan, Zhewen; Chang, Hua-Hua; Douglas, Jeffrey A.

2013-01-01

The item response times (RTs) collected from computerized testing represent an underutilized type of information about items and examinees. In addition to knowing the examinees' responses to each item, we can investigate the amount of time examinees spend on each item. Current models for RTs mainly focus on parametric models, which have the…

Missouri Assessment Program (MAP), Spring 2000: High School Health/Physical Education, Released Items, Grade 9.

ERIC Educational Resources Information Center

Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

This document presents 10 released items from the Health/Physical Education Missouri Assessment Program (MAP) test given in the spring of 2000 to ninth graders. Items from the test sessions include: selected-response (multiple choice), constructed-response, and a performance event. The selected-response items consist of individual questions…

Bi-dimensional acculturation and cultural response set in CES-D among Korean immigrants

PubMed Central

Kim, Eunjung; Seo, Kumin; Cain, Kevin C.

2017-01-01

This study examined a cultural response set to positive affect items and depressive symptom items in CES-D among 172 Korean immigrants. Bi-dimensional acculturation approach, which considers maintenance of Korean Orientation and adoption of American Orientation, was utilized. As Korean immigrants increased American Orientation, they tended to score higher on positive affect items, while no changes occurred in depressive symptom items. Korean Orientation was not related to either positive affect items or depressive symptom items. Korean immigrants have response bias toward positive affect items in CES-D, which decreases as they adopt more American Orientation. CES-D lacks cultural equivalence for Korean immigrants. PMID:20701420

Environmental Controls on the Carbon Isotope Composition of Ecosystem Respired Carbon Dioxide in Contrasting Forest Ecosystems in Canada and USA

NASA Astrophysics Data System (ADS)

Alstad, K.; Lai, C.; Flanagan, L. B.; Ehleringer, J. R.

2006-12-01

Our objective was to compare the carbon isotope composition of respired CO2 (δ13CR) from 11 forest ecosystems in Canada and USA and to examine differences among forests in their response to seasonal variation in photosynthetic photon flux density (PPFD), soil and air temperature, vapor pressure deficit (VPD), precipitation, and soil moisture during May-October 2004. We proposed that variations in δ13CR can be used as a proxy for short-term changes in photosynthetic discrimination and associated shifts in integrated ecosystem-level ci/ca. Our analyses included comparisons of δ13CR responses for three functional groups: deciduous, boreal, and coastal forests. The δ13CR values were well predicted for each group based on the six environmental variables considered, where the highest R2 values determined for the coastal, deciduous, and boreal groups were 0.81, 0.80, and 0.56, respectively. Consistent with several previous studies, the highest correlations between δ13CR and shifts in environmental conditions were achieved when the environmental variables were averaged for 2-, 3- or 4-days previous to δ13CR sample collection. The relationships we observed between δ13CR and environmental factors were consistent with known leaf-level responses, and this was especially apparent within each functional group. However, there were differences among the functional groups for the strength and/or significance of the relationships between δ13CR and particular environmental factors. For example, while VPD and soil temperature were significant determinants of variation in δ13CR in the boreal group, PPFD was not a significant factor and there was only a weak relationship observed between δ13CR and changes in soil moisture. By contrast, in the coastal group, variation in δ13CR was very strongly correlated with changes in PPFD, and there was no significant relationship with VPD. At a single site comparisons made between years suggested the potential application of δ13CR values to assess year-to-year variation in ecosystem physiological responses to changing environmental conditions, but also showed that all environmental factors influencing carbon isotope discrimination during photosynthetic gas exchange need to be considered in such an analysis.

Vegetable parenting practices scale. Item response modeling analyses

PubMed Central

Chen, Tzu-An; O’Connor, Teresia; Hughes, Sheryl; Beltran, Alicia; Baranowski, Janice; Diep, Cassandra; Baranowski, Tom

2015-01-01

Objective To evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We also tested for differences in the ways item function (called differential item functioning) across child’s gender, ethnicity, age, and household income groups. Method Parents of 3–5 year old children completed a self-reported vegetable parenting practices scale online. Vegetable parenting practices consisted of 14 effective vegetable parenting practices and 12 ineffective vegetable parenting practices items, each with three subscales (responsiveness, structure, and control). Multidimensional polytomous item response modeling was conducted separately on effective vegetable parenting practices and ineffective vegetable parenting practices. Results One effective vegetable parenting practice item did not fit the model well in the full sample or across demographic groups, and another was a misfit in differential item functioning analyses across child’s gender. Significant differential item functioning was detected across children’s age and ethnicity groups, and more among effective vegetable parenting practices than ineffective vegetable parenting practices items. Wright maps showed items only covered parts of the latent trait distribution. The harder- and easier-to-respond ends of the construct were not covered by items for effective vegetable parenting practices and ineffective vegetable parenting practices, respectively. Conclusions Several effective vegetable parenting practices and ineffective vegetable parenting practices scale items functioned differently on the basis of child’s demographic characteristics; therefore, researchers should use these vegetable parenting practices scales with caution. Item response modeling should be incorporated in analyses of parenting practice questionnaires to better assess differences across demographic characteristics. PMID:25895694

A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means.

PubMed

Polak, Marike; de Rooij, Mark; Heiser, Willem J

2012-09-01

In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) criterion of irrelevance, which is a graphical, exploratory method for evaluating the "relevance" of dichotomous attitude items. We generalized this criterion to graded response items and quantified the relevance by fitting a unimodal smoother. The resulting goodness-of-fit was used to determine item fit and aggregated scale fit. Based on a simulation procedure, cutoff values were proposed for the measures of item fit. These cutoff values showed high power rates and acceptable Type I error rates. We present 2 applications of the OCM method. First, we apply the OCM method to personality data from the Developmental Profile; second, we analyze attitude data collected by Roberts and Laughlin (1996) concerning opinions of capital punishment.

Nitrification inhibition by hexavalent chromium Cr(VI)--Microbial ecology, gene expression and off-gas emissions.

PubMed

Kim, Young Mo; Park, Hongkeun; Chandran, Kartik

2016-04-01

The goal of this study was to investigate the responses in the physiology, microbial ecology and gene expression of nitrifying bacteria to imposition of and recovery from Cr(VI) loading in a lab-scale nitrification bioreactor. Exposure to Cr(VI) in the reactor strongly inhibited nitrification performance resulting in a parallel decrease in nitrate production and ammonia consumption. Cr(VI) exposure also led to an overall decrease in total bacterial concentrations in the reactor. However, the fraction of ammonia oxidizing bacteria (AOB) decreased to a greater extent than the fraction of nitrite oxidizing bacteria (NOB). In terms of functional gene expression, a rapid decrease in the transcript concentrations of amoA gene coding for ammonia oxidation in AOB was observed in response to the Cr(VI) shock. In contrast, transcript concentrations of the nxrA gene coding for nitrite oxidation in NOB were relatively unchanged compared to Cr(VI) pre-exposure levels. Therefore, Cr(VI) exposure selectively and directly inhibited activity of AOB, which indirectly resulted in substrate (nitrite) limitation to NOB. Significantly, trends in amoA expression preceded performance trends both during imposition of and recovery from inhibition. During recovery from the Cr(VI) shock, the high ammonia concentrations in the bioreactor resulted in an irreversible shift towards AOB populations, which are expected to be more competitive in high ammonia environments. An inadvertent impact during recovery was increased emission of nitrous oxide (N2O) and nitric oxide (NO), consistent with recent findings linking AOB activity and the production of these gases. Therefore, Cr(VI) exposure elicited multiple responses on the microbial ecology, gene expression and both aqueous and gaseous nitrogenous conversion in a nitrification process. A complementary interrogation of these multiple responses facilitated an understanding of both direct and indirect inhibitory impacts on nitrification. Copyright © 2016 Elsevier Ltd. All rights reserved.

Item response theory analysis of the Pain Self-Efficacy Questionnaire.

PubMed

Costa, Daniel S J; Asghari, Ali; Nicholas, Michael K

2017-01-01

The Pain Self-Efficacy Questionnaire (PSEQ) is a 10-item instrument designed to assess the extent to which a person in pain believes s/he is able to accomplish various activities despite their pain. There is strong evidence for the validity and reliability of both the full-length PSEQ and a 2-item version. The purpose of this study is to further examine the properties of the PSEQ using an item response theory (IRT) approach. We used the two-parameter graded response model to examine the category probability curves, and location and discrimination parameters of the 10 PSEQ items. In item response theory, responses to a set of items are assumed to be probabilistically determined by a latent (unobserved) variable. In the graded-response model specifically, item response threshold (the value of the latent variable for which adjacent response categories are equally likely) and discrimination parameters are estimated for each item. Participants were 1511 mixed, chronic pain patients attending for initial assessment at a tertiary pain management centre. All items except item 7 ('I can cope with my pain without medication') performed well in IRT analysis, and the category probability curves suggested that participants used the 7-point response scale consistently. Items 6 ('I can still do many of the things I enjoy doing, such as hobbies or leisure activity, despite pain'), 8 ('I can still accomplish most of my goals in life, despite the pain') and 9 ('I can live a normal lifestyle, despite the pain') captured higher levels of the latent variable with greater precision. The results from this IRT analysis add to the body of evidence based on classical test theory illustrating the strong psychometric properties of the PSEQ. Despite the relatively poor performance of Item 7, its clinical utility warrants its retention in the questionnaire. The strong psychometric properties of the PSEQ support its use as an effective tool for assessing self-efficacy in people with pain. Copyright © 2016 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Comprehensive Review on the Surrogate Endpoints of Efficacy Proposed or Hypothesized in the Scientific Community Today.

PubMed

von Minckwitz, Gunter; Fontanella, Caterina

2015-05-01

An intermediate endpoint is a surrogate marker of treatment efficacy assessed earlier than the true outcome of interest. A suitable intermediate endpoint in neoadjuvant trials of specific breast cancer subtypes is pathological complete response (pCR) rate, defined as no invasive (+/-noninvasive) residual cancer in breast and nodes at surgery. On the basis of available evidence, Food and Drug Administration the US allowed to use of pCR as a surrogate endpoint for accelerated approval process. However, surrogacy to long-term outcome remains an unresolved issue. Literature data provide indications that triple-negative, HER2-positive, and high-grade hormone receptor-positive breast cancer subtypes achieved the highest pCR rate; the prognostic impact of pCR on survival is established only for these aggressive subtypes. In the German experience, early response after two to four cycles of neoadjuvant treatment strongly correlated with both pCR rate and long-term outcome. Therefore, early response may be considered a predictive marker for pCR and used for driving clinical trial design. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Pathologic Complete Response Predicts Recurrence-Free Survival More Effectively by Cancer Subset: Results From the I-SPY 1 TRIAL—CALGB 150007/150012, ACRIN 6657

PubMed Central

Esserman, Laura J.; Berry, Donald A.; DeMichele, Angela; Carey, Lisa; Davis, Sarah E.; Buxton, Meredith; Hudis, Cliff; Gray, Joe W.; Perou, Charles; Yau, Christina; Livasy, Chad; Krontiras, Helen; Montgomery, Leslie; Tripathy, Debasish; Lehman, Constance; Liu, Minetta C.; Olopade, Olufunmilayo I.; Rugo, Hope S.; Carpenter, John T.; Dressler, Lynn; Chhieng, David; Singh, Baljit; Mies, Carolyn; Rabban, Joseph; Chen, Yunn-Yi; Giri, Dilip; van 't Veer, Laura; Hylton, Nola

2012-01-01

Purpose Neoadjuvant chemotherapy for breast cancer provides critical information about tumor response; how best to leverage this for predicting recurrence-free survival (RFS) is not established. The I-SPY 1 TRIAL (Investigation of Serial Studies to Predict Your Therapeutic Response With Imaging and Molecular Analysis) was a multicenter breast cancer study integrating clinical, imaging, and genomic data to evaluate pathologic response, RFS, and their relationship and predictability based on tumor biomarkers. Patients and Methods Eligible patients had tumors ≥ 3 cm and received neoadjuvant chemotherapy. We determined associations between pathologic complete response (pCR; defined as the absence of invasive cancer in breast and nodes) and RFS, overall and within receptor subsets. Results In 221 evaluable patients (median tumor size, 6.0 cm; median age, 49 years; 91% classified as poor risk on the basis of the 70-gene prognosis profile), 41% were hormone receptor (HR) negative, and 31% were human epidermal growth factor receptor 2 (HER2) positive. For 190 patients treated without neoadjuvant trastuzumab, pCR was highest for HR-negative/HER2-positive patients (45%) and lowest for HR-positive/HER2-negative patients (9%). Achieving pCR predicted favorable RFS. For 172 patients treated without trastuzumab, the hazard ratio for RFS of pCR versus no pCR was 0.29 (95% CI, 0.07 to 0.82). pCR was more predictive of RFS by multivariate analysis when subtype was taken into account, and point estimates of hazard ratios within the HR-positive/HER2-negative (hazard ratio, 0.00; 95% CI, 0.00 to 0.93), HR-negative/HER2-negative (hazard ratio, 0.25; 95% CI, 0.04 to 0.97), and HER2-positive (hazard ratio, 0.14; 95% CI, 0.01 to 1.0) subtypes are lower. Ki67 further improved the prediction of pCR within subsets. Conclusion In this biologically high-risk group, pCR differs by receptor subset. pCR is more highly predictive of RFS within every established receptor subset than overall, demonstrating that the extent of outcome advantage conferred by pCR is specific to tumor biology. PMID:22649152

Interim heterogeneity changes measured using entropy texture features on T2-weighted MRI at 3.0 T are associated with pathological response to neoadjuvant chemotherapy in primary breast cancer.

PubMed

Henderson, Shelley; Purdie, Colin; Michie, Caroline; Evans, Andrew; Lerski, Richard; Johnston, Marilyn; Vinnicombe, Sarah; Thompson, Alastair M

2017-11-01

To investigate whether interim changes in hetereogeneity (measured using entropy features) on MRI were associated with pathological residual cancer burden (RCB) at final surgery in patients receiving neoadjuvant chemotherapy (NAC) for primary breast cancer. This was a retrospective study of 88 consenting women (age: 30-79 years). Scanning was performed on a 3.0 T MRI scanner prior to NAC (baseline) and after 2-3 cycles of treatment (interim). Entropy was derived from the grey-level co-occurrence matrix, on slice-matched baseline/interim T2-weighted images. Response, assessed using RCB score on surgically resected specimens, was compared statistically with entropy/heterogeneity changes and ROC analysis performed. Association of pCR within each tumour immunophenotype was evaluated. Mean entropy percent differences between examinations, by response category, were: pCR: 32.8%, RCB-I: 10.5%, RCB-II: 9.7% and RCB-III: 3.0%. Association of ultimate pCR with coarse entropy changes between baseline/interim MRI across all lesions yielded 85.2% accuracy (area under ROC curve: 0.845). Excellent sensitivity/specificity was obtained for pCR prediction within each immunophenotype: ER+: 100%/100%; HER2+: 83.3%/95.7%, TNBC: 87.5%/80.0%. Lesion T2 heterogeneity changes are associated with response to NAC using RCB scores, particularly for pCR, and can be useful across all immunophenotypes with good diagnostic accuracy. • Texture analysis provides a means of measuring lesion heterogeneity on MRI images. • Heterogeneity changes between baseline/interim MRI can be linked with ultimate pathological response. • Heterogeneity changes give good diagnostic accuracy of pCR response across all immunophenotypes. • Percentage reduction in heterogeneity is associated with pCR with good accuracy and NPV.

Overview of Classical Test Theory and Item Response Theory for Quantitative Assessment of Items in Developing Patient-Reported Outcome Measures

PubMed Central

Cappelleri, Joseph C.; Lundy, J. Jason; Hays, Ron D.

2014-01-01

Introduction The U.S. Food and Drug Administration’s patient-reported outcome (PRO) guidance document defines content validity as “the extent to which the instrument measures the concept of interest” (FDA, 2009, p. 12). “Construct validity is now generally viewed as a unifying form of validity for psychological measurements, subsuming both content and criterion validity” (Strauss & Smith, 2009, p. 7). Hence both qualitative and quantitative information are essential in evaluating the validity of measures. Methods We review classical test theory and item response theory approaches to evaluating PRO measures including frequency of responses to each category of the items in a multi-item scale, the distribution of scale scores, floor and ceiling effects, the relationship between item response options and the total score, and the extent to which hypothesized “difficulty” (severity) order of items is represented by observed responses. Conclusion Classical test theory and item response theory can be useful in providing a quantitative assessment of items and scales during the content validity phase of patient-reported outcome measures. Depending on the particular type of measure and the specific circumstances, either one or both approaches should be considered to help maximize the content validity of PRO measures. PMID:24811753

Item Response Theory Using Hierarchical Generalized Linear Models

ERIC Educational Resources Information Center

Ravand, Hamdollah

2015-01-01

Multilevel models (MLMs) are flexible in that they can be employed to obtain item and person parameters, test for differential item functioning (DIF) and capture both local item and person dependence. Papers on the MLM analysis of item response data have focused mostly on theoretical issues where applications have been add-ons to simulation…

Item Response Theory Equating Using Bayesian Informative Priors.

ERIC Educational Resources Information Center

de la Torre, Jimmy; Patz, Richard J.

This paper seeks to extend the application of Markov chain Monte Carlo (MCMC) methods in item response theory (IRT) to include the estimation of equating relationships along with the estimation of test item parameters. A method is proposed that incorporates estimation of the equating relationship in the item calibration phase. Item parameters from…

Instrument Formatting with Computer Data Entry in Mind.

ERIC Educational Resources Information Center

Boser, Judith A.; And Others

Different formats for four types of research items were studied for ease of computer data entry. The types were: (1) numeric response items; (2) individual multiple choice items; (3) multiple choice items with the same response items; and (4) card column indicator placement. Each of the 13 experienced staff members of a major university's Data…

General Oral Health Assessment Index: A new evaluation proposal.

PubMed

Campos, Juliana A D B; Zucoloto, Miriane L; Bonafé, Fernanda S S; Maroco, João

2017-09-01

To validity the General Oral Health Assessment Index (GOHAI) among adults who sought dental care and to present a new proposal for calculating scores on self-perception of oral health. There is no study that presents a GOHAI scores using weight of the items. The one-factor model, the three-factor model (physical function, psychosocial/psychological function and pain/discomfort) and the second-order hierarchical model (SOHM) were evaluated from confirmatory factor analysis (λ, χ 2 /df, CFI,GFI and RMSEA). The reliability (CR,α) was estimated. Concurrent validity was assessed using the Oral Health Impact Profile (OHIP-14). The invariance of the models was estimated in independent samples. The calculation of an overall score using the factor scores was proposed to obtain the overall weighted scores. These overall weighted scores were compared to the scores estimated as the simple arithmetic mean (overall unweighted scores) using a repeated measures analysis of variance. A total of 1000 individuals participated (74.1% female; age: 40.7 (SD=14.3) years). Three items of the GOHAI were excluded (λ<0.40). The one-factor model (λ=0.40-0.77; χ 2 /df=6.291; CFI=0.947; GFI=0.960; RMSEA=0.073) and the three-factor model (λ=0.40-0.78; χ 2 /df=8.321; CFI=0.932; GFI=0.954; RMSEA=0.086) each presented an adequate fit. Reliability was adequate (one-factor: CR=0.83/α=0.83; three-factor: CR=0.53-0.76/α=0.53-0.73), with the exception of the pain/discomfort factor. The GOHAI was invariant in independent samples, and the concurrent validity was adequate. The overall unweighted scores overestimated self-perceptions of oral health when compared with the weighted scores. Both the one-factor and three-factor models of the GOHAI were found to be valid, reliable and invariant for the sample after the exclusion of three items. The use of overall weighted scores is recommended for calculating the score of self-perception of oral health. © 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Consequences of Ignoring Guessing when Estimating the Latent Density in Item Response Theory

ERIC Educational Resources Information Center

Woods, Carol M.

2008-01-01

In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters. In extant Monte Carlo evaluations of RC-IRT, the item response function (IRF) used to fit the data is the same one used to generate the data. The present simulation study examines RC-IRT when the IRF is imperfectly…

Asymptotic Properties of Induced Maximum Likelihood Estimates of Nonlinear Models for Item Response Variables: The Finite-Generic-Item-Pool Case.

ERIC Educational Resources Information Center

Jones, Douglas H.

The progress of modern mental test theory depends very much on the techniques of maximum likelihood estimation, and many popular applications make use of likelihoods induced by logistic item response models. While, in reality, item responses are nonreplicate within a single examinee and the logistic models are only ideal, practitioners make…

Limits on Log Cross-Product Ratios for Item Response Models. Research Report. ETS RR-06-10

ERIC Educational Resources Information Center

Haberman, Shelby J.; Holland, Paul W.; Sinharay, Sandip

2006-01-01

Bounds are established for log cross-product ratios (log odds ratios) involving pairs of items for item response models. First, expressions for bounds on log cross-product ratios are provided for unidimensional item response models in general. Then, explicit bounds are obtained for the Rasch model and the two-parameter logistic (2PL) model.…

Nomogram predicting response after chemoradiotherapy in rectal cancer using sequential PETCT imaging: a multicentric prospective study with external validation.

PubMed

van Stiphout, Ruud G P M; Valentini, Vincenzo; Buijsen, Jeroen; Lammering, Guido; Meldolesi, Elisa; van Soest, Johan; Leccisotti, Lucia; Giordano, Alessandro; Gambacorta, Maria A; Dekker, Andre; Lambin, Philippe

2014-11-01

To develop and externally validate a predictive model for pathologic complete response (pCR) for locally advanced rectal cancer (LARC) based on clinical features and early sequential (18)F-FDG PETCT imaging. Prospective data (i.a. THUNDER trial) were used to train (N=112, MAASTRO Clinic) and validate (N=78, Università Cattolica del S. Cuore) the model for pCR (ypT0N0). All patients received long-course chemoradiotherapy (CRT) and surgery. Clinical parameters were age, gender, clinical tumour (cT) stage and clinical nodal (cN) stage. PET parameters were SUVmax, SUVmean, metabolic tumour volume (MTV) and maximal tumour diameter, for which response indices between pre-treatment and intermediate scan were calculated. Using multivariate logistic regression, three probability groups for pCR were defined. The pCR rates were 21.4% (training) and 23.1% (validation). The selected predictive features for pCR were cT-stage, cN-stage, response index of SUVmean and maximal tumour diameter during treatment. The models' performances (AUC) were 0.78 (training) and 0.70 (validation). The high probability group for pCR resulted in 100% correct predictions for training and 67% for validation. The model is available on the website www.predictcancer.org. The developed predictive model for pCR is accurate and externally validated. This model may assist in treatment decisions during CRT to select complete responders for a wait-and-see policy, good responders for extra RT boost and bad responders for additional chemotherapy. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Improving the Reliability of Student Scores from Speeded Assessments: An Illustration of Conditional Item Response Theory Using a Computer-Administered Measure of Vocabulary.

PubMed

Petscher, Yaacov; Mitchell, Alison M; Foorman, Barbara R

2015-01-01

A growing body of literature suggests that response latency, the amount of time it takes an individual to respond to an item, may be an important factor to consider when using assessment data to estimate the ability of an individual. Considering that tests of passage and list fluency are being adapted to a computer administration format, it is possible that accounting for individual differences in response times may be an increasingly feasible option to strengthen the precision of individual scores. The present research evaluated the differential reliability of scores when using classical test theory and item response theory as compared to a conditional item response model which includes response time as an item parameter. Results indicated that the precision of student ability scores increased by an average of 5 % when using the conditional item response model, with greater improvements for those who were average or high ability. Implications for measurement models of speeded assessments are discussed.

Improving the Reliability of Student Scores from Speeded Assessments: An Illustration of Conditional Item Response Theory Using a Computer-Administered Measure of Vocabulary

PubMed Central

Petscher, Yaacov; Mitchell, Alison M.; Foorman, Barbara R.

2016-01-01

A growing body of literature suggests that response latency, the amount of time it takes an individual to respond to an item, may be an important factor to consider when using assessment data to estimate the ability of an individual. Considering that tests of passage and list fluency are being adapted to a computer administration format, it is possible that accounting for individual differences in response times may be an increasingly feasible option to strengthen the precision of individual scores. The present research evaluated the differential reliability of scores when using classical test theory and item response theory as compared to a conditional item response model which includes response time as an item parameter. Results indicated that the precision of student ability scores increased by an average of 5 % when using the conditional item response model, with greater improvements for those who were average or high ability. Implications for measurement models of speeded assessments are discussed. PMID:27721568

Evaluation with 3.0-T MR imaging: predicting the pathological response of triple-negative breast cancer treated with anthracycline and taxane neoadjuvant chemotherapy.

PubMed

Kim, Min Jung; Kim, Eun-Kyung; Park, Seho; Moon, Hee Jung; Kim, Seung Il; Park, Byeong-Woo

2015-09-01

Triple-negative breast cancer (TNBC) which expresses neither hormonal receptors nor HER-2 is associated with poor prognosis and shorter survival. Several studies have suggested that TNBC patients attaining pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) show a longer survival than those without pCR. To assess the accuracy of 3.0-T breast magnetic resonance imaging (MRI) in predicting pCR and to evaluate the clinicoradiologic factors affecting the diagnostic accuracy of 3.0-T breast MRI in TNBC patients treated with anthracycline and taxane (ACD). This retrospective study was approved by the institutional review board; patient consent was not required. Between 2009 and 2012, 35 TNBC patients with 3.0-T breast MRI prior to (n = 26) or after (n = 35) NAC were included. MRI findings were reviewed according to pCR to chemotherapy. The diagnostic accuracy of 3.0-T breast MRI for predicting pCR and the clinicoradiological factors affecting MRI accuracy and response to NAC were analyzed. 3.0-T MRI following NAC with ACD accurately predicted pCR in 91.4% of TNBC patients. The residual tumor size between pathology and 3.0-T MRI in non-pCR cases showed a higher correlation in the Ki-67-positive TNBC group (r = 0.947) than in the Ki-67 negative group (r = 0.375) with statistical trends (P = 0.069). Pre-treatment MRI in the non-pCR group compared to the pCR group showed a larger tumor size (P = 0.030) and non-mass presentation (P = 0.015). 3.0-T MRI in TNBC patients following NAC with ACD showed a high accuracy for predicting pCR to NAC. Ki-67 can affect the diagnostic accuracy of 3.0-T MRI for pCR to NAC with ACD in TNBC patients. © The Foundation Acta Radiologica 2014.

Differential antioxidative enzyme responses of Jatropha curcas L. to chromium stress.

PubMed

Yadav, Santosh Kumar; Dhote, Monika; Kumar, Phani; Sharma, Jitendra; Chakrabarti, Tapan; Juwarkar, Asha A

2010-08-15

Chromium (Cr) tolerant and accumulation capability of Jatropha curcas L. was tested in Cr spiked soil amended with biosludge and biofertilizer. Plants were cultivated in soils containing 0, 25, 50, 100 and 250 mg kg(-1) of Cr for one year with and without amendment. Plant tissue analysis showed that combined application of biosludge and biofertilizer could significantly reduce Cr uptake and boost the plant biomass, whereas biofertilizer alone did not affect the uptake and plant growth. Antioxidative responses of catalase (CAT), ascorbate peroxidase (APX) and glutathione S-transferase (GST) were increased with increasing Cr concentration in plant. Hyperactivity of the CAT and GST indicated that antioxidant enzymes played an important role in protecting the plant from Cr toxicity. However, APX took a little part in detoxification of H(2)O(2) due to its sensitivity to Cr. Therefore, reduced APX activity was recorded. Reduced glutathione (GSH) activity was recorded in plant grown on/above 100 mg kg(-1) of Cr in soil. The study concludes that J. curcas could grow under chromium stress. Furthermore, the results encouraged that J. curcas is a suitable candidate for the restoration of Cr contaminated soils with the concomitant application of biosludge and biofertilizer. Copyright 2010 Elsevier B.V. All rights reserved.

Caloric restriction enhances fear extinction learning in mice.

PubMed

Riddle, Megan C; McKenna, Morgan C; Yoon, Yone J; Pattwell, Siobhan S; Santos, Patricia Mae G; Casey, B J; Glatt, Charles E

2013-05-01

Fear extinction learning, the ability to reassess a learned cue of danger as safe when it no longer predicts aversive events, is often dysregulated in anxiety disorders. Selective serotonin reuptake inhibitors (SSRI's) enhance neural plasticity and their ability to enhance fear extinction learning may explain their anxiolytic properties. Caloric restriction (CR) has SSRI-like effects on neural plasticity and anxiety-related behavior. We implemented CR in mice to determine its effects on conditioned-fear responses. Wild type and serotonin transporter (SERT) knockout mice underwent CR for 7 days leading to significant weight loss. Mice were then tested for cued fear learning and anxiety-related behavior. CR markedly enhanced fear extinction learning and its retention in adolescent female mice, and adults of both sexes. These effects of CR were absent in SERT knockout mice. Moreover, CR phenocopied behavioral and molecular effects of chronic fluoxetine, but there was no additive effect of CR in fluoxetine-treated mice. These results demonstrate that CR enhances fear extinction learning through a SERT-dependent mechanism. These results may have implications for eating disorders such as anorexia nervosa (AN), in which there is a high prevalence of anxiety before the onset of dietary restriction and support proposals that in AN, CR is a motivated effort to control dysregulated fear responses and elevated anxiety.

The effects of graded levels of calorie restriction: III. Impact of short term calorie and protein restriction on mean daily body temperature and torpor use in the C57BL/6 mouse

PubMed Central

Mitchell, Sharon E.; Delville, Camille; Konstantopedos, Penelope; Derous, Davina; Green, Cara L.; Chen, Luonan; Han, Jing-Dong J.; Wang, Yingchun; Promislow, Daniel E.L.; Douglas, Alex; Lusseau, David; Speakman, John R.

2015-01-01

A commonly observed response in mammals to calorie restriction (CR) is reduced body temperature (Tb). We explored how the Tb of male C57BL/6 mice responded to graded CR (10 to 40%), compared to the response to equivalent levels of protein restriction (PR) over 3 months. Under CR there was a dynamic change in daily Tb over the first 30–35 days, which stabilized thereafter until day 70 after which a further decline was noted. The time to reach stability was dependent on restriction level. Body mass negatively correlated with Tb under ad libitum feeding and positively correlated under CR. The average Tb over the last 20 days was significantly related to the levels of body fat, structural tissue, leptin and insulin-like growth factor-1. Some mice, particularly those under higher levels of CR, showed periods of daily torpor later in the restriction period. None of the changes in Tb under CR were recapitulated by equivalent levels of PR. We conclude that changes in Tb under CR are a response only to the shortfall in calorie intake. The linear relationship between average Tb and the level of restriction supports the idea that Tb changes are an integral aspect of the lifespan effect. PMID:26286956

The Effect of Response Format on the Psychometric Properties of the Narcissistic Personality Inventory: Consequences for Item Meaning and Factor Structure.

PubMed

Ackerman, Robert A; Donnellan, M Brent; Roberts, Brent W; Fraley, R Chris

2016-04-01

The Narcissistic Personality Inventory (NPI) is currently the most widely used measure of narcissism in social/personality psychology. It is also relatively unique because it uses a forced-choice response format. We investigate the consequences of changing the NPI's response format for item meaning and factor structure. Participants were randomly assigned to one of three conditions: 40 forced-choice items (n = 2,754), 80 single-stimulus dichotomous items (i.e., separate true/false responses for each item; n = 2,275), or 80 single-stimulus rating scale items (i.e., 5-point Likert-type response scales for each item; n = 2,156). Analyses suggested that the "narcissistic" and "nonnarcissistic" response options from the Entitlement and Superiority subscales refer to independent personality dimensions rather than high and low levels of the same attribute. In addition, factor analyses revealed that although the Leadership dimension was evident across formats, dimensions with entitlement and superiority were not as robust. Implications for continued use of the NPI are discussed. © The Author(s) 2015.

Asymptotic Standard Errors for Item Response Theory True Score Equating of Polytomous Items

ERIC Educational Resources Information Center

Cher Wong, Cheow

2015-01-01

Building on previous works by Lord and Ogasawara for dichotomous items, this article proposes an approach to derive the asymptotic standard errors of item response theory true score equating involving polytomous items, for equivalent and nonequivalent groups of examinees. This analytical approach could be used in place of empirical methods like…

Evaluation of Northwest University, Kano Post-UTME Test Items Using Item Response Theory

ERIC Educational Resources Information Center

Bichi, Ado Abdu; Hafiz, Hadiza; Bello, Samira Abdullahi

2016-01-01

High-stakes testing is used for the purposes of providing results that have important consequences. Validity is the cornerstone upon which all measurement systems are built. This study applied the Item Response Theory principles to analyse Northwest University Kano Post-UTME Economics test items. The developed fifty (50) economics test items was…

Examination of Polytomous Items' Psychometric Properties According to Nonparametric Item Response Theory Models in Different Test Conditions

ERIC Educational Resources Information Center

Sengul Avsar, Asiye; Tavsancil, Ezel

2017-01-01

This study analysed polytomous items' psychometric properties according to nonparametric item response theory (NIRT) models. Thus, simulated datasets--three different test lengths (10, 20 and 30 items), three sample distributions (normal, right and left skewed) and three samples sizes (100, 250 and 500)--were generated by conducting 20…

Rasch Measurement and Item Banking: Theory and Practice.

ERIC Educational Resources Information Center

Nakamura, Yuji

The Rasch Model is an item response theory, one parameter model developed that states that the probability of a correct response on a test is a function of the difficulty of the item and the ability of the candidate. Item banking is useful for language testing. The Rasch Model provides estimates of item difficulties that are meaningful,…

Item Response Theory Models for Wording Effects in Mixed-Format Scales

ERIC Educational Resources Information Center

Wang, Wen-Chung; Chen, Hui-Fang; Jin, Kuan-Yu

2015-01-01

Many scales contain both positively and negatively worded items. Reverse recoding of negatively worded items might not be enough for them to function as positively worded items do. In this study, we commented on the drawbacks of existing approaches to wording effect in mixed-format scales and used bi-factor item response theory (IRT) models to…

Vegetable parenting practices scale: Item response modeling analyses

USDA-ARS?s Scientific Manuscript database

Our objective was to evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We al...

Chromium Enhances Insulin Responsiveness via AMPK

PubMed Central

Hoffman, Nolan J.; Penque, Brent A.; Habegger, Kirk M.; Sealls, Whitney; Tackett, Lixuan; Elmendorf, Jeffrey S.

2014-01-01

Trivalent chromium (Cr3+) is known to improve glucose homeostasis. Cr3+ has been shown to improve plasma membrane-based aspects of glucose transporter GLUT4 regulation and increase activity of the cellular energy sensor 5′ AMP-activated protein kinase (AMPK). However, the mechanism(s) by which Cr3+ improves insulin responsiveness and whether AMPK mediates this action is not known. In this study we tested if Cr3+ protected against physiological hyperinsulinemia-induced plasma membrane cholesterol accumulation, cortical filamentous actin (F-actin) loss and insulin resistance in L6 skeletal muscle myotubes. In addition, we performed mechanistic studies to test our hypothesis that AMPK mediates the effects of Cr3+ on GLUT4 and glucose transport regulation. Hyperinsulinemia-induced insulin-resistant L6 myotubes displayed excess membrane cholesterol and diminished cortical F-actin essential for effective glucose transport regulation. These membrane and cytoskeletal abnormalities were associated with defects in insulin-stimulated GLUT4 translocation and glucose transport. Supplementing the culture medium with pharmacologically relevant doses of Cr3+ in the picolinate form (CrPic) protected against membrane cholesterol accumulation, F-actin loss, GLUT4 dysregulation and glucose transport dysfunction. Insulin signaling was neither impaired by hyperinsulinemic conditions nor enhanced by CrPic, whereas CrPic increased AMPK signaling. Mechanistically, siRNA-mediated depletion of AMPK abolished the protective effects of CrPic against GLUT4 and glucose transport dysregulation. Together these findings suggest that the micronutrient Cr3+, via increasing AMPK activity, positively impacts skeletal muscle cell insulin sensitivity and glucose transport regulation. PMID:24725432

The effects of graded levels of calorie restriction: XI. Evaluation of the main hypotheses underpinning the life extension effects of CR using the hepatic transcriptome.

PubMed

Derous, Davina; Mitchell, Sharon E; Wang, Lu; Green, Cara L; Wang, Yingchun; Chen, Luonan; Han, Jing-Dong J; Promislow, Daniel E L; Lusseau, David; Douglas, Alex; Speakman, John R

2017-07-31

Calorie restriction (CR) may extend longevity by modulating the mechanisms involved in aging. Different hypotheses have been proposed for its main mode of action. We quantified hepatic transcripts of male C57BL/6 mice exposed to graded levels of CR (0% to 40% CR) for three months, and evaluated the responses relative to these various hypotheses. Of the four main signaling pathways implied to be linked to the impact of CR on lifespan (insulin/insulin like growth factor 1 (IGF-1), nuclear factor-kappa beta (NF-ĸB), mechanistic target of rapamycin (mTOR) and sirtuins (SIRTs)), all the pathways except SIRT were altered in a manner consistent with increased lifespan. However, the expression levels of SIRT4 and SIRT7 were decreased with increasing levels of CR. Changes consistent with altered fuel utilization under CR may reduce reactive oxygen species production, which was paralleled by reduced protection. Downregulated major urinary protein (MUP) transcription suggested reduced reproductive investment. Graded CR had a positive effect on autophagy and xenobiotic metabolism, and was protective with respect to cancer signaling. CR had no significant effect on fibroblast growth factor-21 (FGF21) transcription but affected transcription in the hydrogen sulfide production pathway. Responses to CR were consistent with several different hypotheses, and the benefits of CR on lifespan likely reflect the combined impact on multiple aging related processes.

The effects of graded levels of calorie restriction: XI. Evaluation of the main hypotheses underpinning the life extension effects of CR using the hepatic transcriptome

PubMed Central

Derous, Davina; Mitchell, Sharon E.; Wang, Lu; Green, Cara L.; Wang, Yingchun; Chen, Luonan; Han, Jing-Dong J.; Promislow, Daniel E.L.; Lusseau, David; Douglas, Alex; Speakman, John R.

2017-01-01

Calorie restriction (CR) may extend longevity by modulating the mechanisms involved in aging. Different hypotheses have been proposed for its main mode of action. We quantified hepatic transcripts of male C57BL/6 mice exposed to graded levels of CR (0% to 40% CR) for three months, and evaluated the responses relative to these various hypotheses. Of the four main signaling pathways implied to be linked to the impact of CR on lifespan (insulin/insulin like growth factor 1 (IGF-1), nuclear factor-kappa beta (NF-ĸB), mechanistic target of rapamycin (mTOR) and sirtuins (SIRTs)), all the pathways except SIRT were altered in a manner consistent with increased lifespan. However, the expression levels of SIRT4 and SIRT7 were decreased with increasing levels of CR. Changes consistent with altered fuel utilization under CR may reduce reactive oxygen species production, which was paralleled by reduced protection. Downregulated major urinary protein (MUP) transcription suggested reduced reproductive investment. Graded CR had a positive effect on autophagy and xenobiotic metabolism, and was protective with respect to cancer signaling. CR had no significant effect on fibroblast growth factor-21 (FGF21) transcription but affected transcription in the hydrogen sulfide production pathway. Responses to CR were consistent with several different hypotheses, and the benefits of CR on lifespan likely reflect the combined impact on multiple aging related processes. PMID:28768896

A Multi-responsive Regenerable Europium-Organic Framework Luminescent Sensor for Fe3+ , CrVI Anions, and Picric Acid.

PubMed

Liu, Wei; Huang, Xin; Xu, Cong; Chen, Chunyang; Yang, Lizi; Dou, Wei; Chen, Wanmin; Yang, Huan; Liu, Weisheng

2016-12-23

A novel luminescent microporous lanthanide metal-organic framework (Ln-MOF) based on a urea-containing ligand has been successfully assembled. Structural analysis revealed that the framework features two types of 1D channels, with urea N-H bonds projecting into the pores. Luminescence studies have revealed that the Ln-MOF exhibits high sensitivity, good selectivity, and a fast luminescence quenching response towards Fe 3+ , Cr VI anions, and picric acid. In particular, in the detection of Cr 2 O 7 2- and picric acid, the Ln-MOF can be simply and quickly regenerated, thus exhibiting excellent recyclability. To the best of our knowledge, this is the first example of a multi-responsive luminescent Ln-MOF sensor for Fe 3+ , Cr VI anions, and picric acid based on a urea derivative. This Ln-MOF may potentially be used as a multi-responsive regenerable luminescent sensor for the quantitative detection of toxic and harmful substances. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lung Inflammation, Injury, and Proliferative Response after Repetitive Particulate Hexavalent Chromium Exposure

PubMed Central

Beaver, Laura M.; Stemmy, Erik J.; Schwartz, Arnold M.; Damsker, Jesse M.; Constant, Stephanie L.; Ceryak, Susan M.; Patierno, Steven R.

2009-01-01

Background Chronic inflammation is implicated in the development of several human cancers, including lung cancer. Certain particulate hexavalent chromium [Cr(VI)] compounds are well-documented human respiratory carcinogens that release genotoxic soluble chromate and are associated with fibrosis, fibrosarcomas, adenocarcinomas, and squamous cell carcinomas of the lung. Despite this, little is known about the pathologic injury and immune responses after repetitive exposure to particulate chromates. Objectives In this study we investigated the lung injury, inflammation, proliferation, and survival signaling responses after repetitive exposure to particulate chromate. Methods BALB/c mice were repetitively treated with particulate basic zinc chromate or saline using an intranasal exposure regimen. We assessed lungs for Cr(VI)-induced changes by bronchoalveolar lavage, histologic examination, and immunohistochemistry. Results Single exposure to Cr(VI) resulted in inflammation of lung tissue that persists for up to 21 days. Repetitive Cr(VI) exposure induced a neutrophilic inflammatory airway response 24 hr after each treatment. Neutrophils were subsequently replaced by increasing numbers of macrophages by 5 days after treatment. Repetitive Cr(VI) exposure induced chronic peribronchial inflammation with alveolar and interstitial pneumonitis dominated by lymphocytes and macrophages. Moreover, chronic toxic mucosal injury was observed and accompanied by increased airway pro-matrix metalloprotease-9. Injury and inflammation correlated with airways becoming immunoreactive for phosphorylation of the survival signaling protein Akt and the proliferation marker Ki-67. We observed a reactive proliferative response in epithelial cells lining airways of chromate-exposed animals. Conclusions These data illustrate that repetitive exposure to particulate chromate induces chronic injury and an inflammatory microenvironment that may promote Cr(VI) carcinogenesis. PMID:20049209

A HO-IRT Based Diagnostic Assessment System with Constructed Response Items

ERIC Educational Resources Information Center

Yang, Chih-Wei; Kuo, Bor-Chen; Liao, Chen-Huei

2011-01-01

The aim of the present study was to develop an on-line assessment system with constructed response items in the context of elementary mathematics curriculum. The system recorded the problem solving process of constructed response items and transfered the process to response codes for further analyses. An inference mechanism based on artificial…

Structural Equation Model Approach to the Use of Response Times for Improving Estimation in Item Response Models

ERIC Educational Resources Information Center

Sen, Rohini

2012-01-01

In the last five decades, research on the uses of response time has extended into the field of psychometrics (Schnikpe & Scrams, 1999; van der Linden, 2006; van der Linden, 2007), where interest has centered around the usefulness of response time information in item calibration and person measurement within an item response theory. framework.…

A Primer on the 2- and 3-Parameter Item Response Theory Models.

ERIC Educational Resources Information Center

Thornton, Artist

Item response theory (IRT) is a useful and effective tool for item response measurement if used in the proper context. This paper discusses the sets of assumptions under which responses can be modeled while exploring the framework of the IRT models relative to response testing. The one parameter model, or one parameter logistic model, is perhaps…

Analysis Test of Understanding of Vectors with the Three-Parameter Logistic Model of Item Response Theory and Item Response Curves Technique

ERIC Educational Resources Information Center

Rakkapao, Suttida; Prasitpong, Singha; Arayathanitkul, Kwan

2016-01-01

This study investigated the multiple-choice test of understanding of vectors (TUV), by applying item response theory (IRT). The difficulty, discriminatory, and guessing parameters of the TUV items were fit with the three-parameter logistic model of IRT, using the parscale program. The TUV ability is an ability parameter, here estimated assuming…

Impact of Race, Ethnicity and BMI on Achievement of Pathologic Complete Response Following Neoadjuvant Chemotherapy for Breast Cancer: A Pooled Analysis of Four Prospective Alliance Clinical Trials (A151426)

PubMed Central

Warner, Erica T.; Ballman, Karla V.; Strand, Carrie; Boughey, Judy; Buzdar, Aman U.; Carey, Lisa A.; Sikov, William M.; Partridge, H.

2016-01-01

Purpose Previous studies demonstrated poor response to neoadjuvant systemic therapy (NST) for breast cancer among black women and women who are overweight or obese but this may be due to chemotherapy under dosing. We assessed associations of race, ethnicity and body mass index (BMI) with pathologic complete response (pCR) in clinical trial populations. Methods 1797 women enrolled in four NST trials (CALGB 40601, 40603; ACOSOG Z1041, Z1071) were included. Tumor subtypes were defined by estrogen receptor (ER) and HER2 status. Logistic regression generated odds ratios (OR) and 95% confidence intervals (CI) for the associations of race, ethnicity, and BMI with pCR adjusting for subtype, study arm, lymph node status, tumor size, and tumor grade. Results 253 (14.1%) were black, 199 (11.1%) Hispanic, 520 (28.9%) overweight, and 743 (41.4%) obese. Compared to whites, Blacks and Hispanics were more likely to be obese and Blacks were more likely to have triple-negative cancer. pCR rates differed significantly by tumor subtype. In multivariate analyses, neither race (black vs. white: OR: 1.18, 95% CI: 0.85–1.62) nor ethnicity (Hispanic vs. non-Hispanic: OR: 1.30, 95% CI: 0.67–2.53) were significant predictors of pCR overall or by subtype. Overweight and obese women had lower pCR rates in ER+/HER2+, but higher pCR rates in ER−/HER2+ cancers. Conclusions There was no difference in breast pCR according to race or ethnicity. Overall, there was no major difference in pCR rates by BMI. These findings suggest that pCR with optimally dosed NST is a function of tumor, rather than patient, biology. PMID:27449492

Impact of race, ethnicity, and BMI on achievement of pathologic complete response following neoadjuvant chemotherapy for breast cancer: a pooled analysis of four prospective Alliance clinical trials (A151426).

PubMed

Warner, Erica T; Ballman, Karla V; Strand, Carrie; Boughey, Judy C; Buzdar, Aman U; Carey, Lisa A; Sikov, William M; Partridge, Ann H

2016-08-01

Previous studies demonstrated poor response to neoadjuvant systemic therapy (NST) for breast cancer among black women and women who are overweight or obese, but this may be due to chemotherapy underdosing. We assessed associations of race, ethnicity, and body mass index (BMI) with pathologic complete response (pCR) in clinical trial populations. 1797 women enrolled in four NST trials (CALGB 40601, 40603; ACOSOG Z1041, Z1071) were included. Tumor subtypes were defined by estrogen receptor (ER) and HER2 status. Logistic regression generated odds ratios (OR) and 95 % confidence intervals (CI) for the associations of race, ethnicity, and BMI with in-breast pCR adjusting for subtype, study arm, lymph node status, tumor size, and tumor grade. 253 (14.1 %) were black, 199 (11.1 %) Hispanic, 520 (28.9 %) overweight, and 743 (41.4 %) obese. Compared to whites, Blacks and Hispanics were more likely to be obese and Blacks were more likely to have triple-negative cancer. pCR rates differed significantly by tumor subtype. In multivariate analyses, neither race (black vs white: OR 1.18, 95 % CI 0.85-1.62) nor ethnicity (Hispanic vs non-Hispanic; OR 1.30, 95 % CI 0.67-2.53) were significant predictors of pCR overall or by subtype. Overweight and obese women had lower pCR rates in ER+/HER2+, but higher pCR rates in ER-/HER2+ cancers. There was no difference in pCR according to race or ethnicity. Overall, there was no major difference in pCR rates by BMI. These findings suggest that pCR with optimally dosed NST is a function of tumor, rather than patient, biology.

The role of quantitative estrogen receptor status in predicting tumor response at surgery in breast cancer patients treated with neoadjuvant chemotherapy.

PubMed

Raphael, Jacques; Gandhi, Sonal; Li, Nim; Lu, Fang-I; Trudeau, Maureen

2017-07-01

Estrogen receptor (ER) negative (-) breast cancer (BC) patients have better tumor response rates than ER-positive (+) patients after neoadjuvant chemotherapy (NCT). We conducted a retrospective review using the institutional database "Biomatrix" to assess the value of quantitative ER status in predicting tumor response at surgery and to identify potential predictors of survival outcomes. Univariate followed by multivariable regression analyses were conducted to assess the association between quantitative ER and tumor response assessed as tumor size reduction and pathologic complete response (pCR). Predictors of recurrence-free survival (RFS) were identified using a cox proportional hazards model (CPH). A log-rank test was used to compare RFS between groups if a significant predictor was identified. 304 patients were included with a median follow-up of 43.3 months (Q1-Q3 28.7-61.1) and a mean age of 49.7 years (SD 10.9). Quantitative ER was inversely associated with tumor size reduction and pCR (OR 0.99, 95% CI 0.99-1.00, p = 0.027 and 0.98 95% CI 0.97-0.99, p < 0.0001, respectively). A cut-off of 60 and 80% predicted best the association with tumor size reduction and pCR, respectively. pCR was shown to be an independent predictor of RFS (HR 0.17, 95% CI 0.07-0.43, p = 0.0002) in all patients. At 5 years, 93% of patients with pCR and 72% of patients with residual tumor were recurrence-free, respectively (p = 0.0012). Quantitative ER status is inversely associated with tumor response in BC patients treated with NCT. A cut-off of 60 and 80% predicts best the association with tumor size reduction and pCR, respectively. Therefore, patients with an ER status higher than the cut-off might benefit from a neoadjuvant endocrine therapy approach. Patients with pCR had better survival outcomes independently of their tumor phenotype. Further prospective studies are needed to validate the clinical utility of quantitative ER as a predictive marker of tumor response.

Meta-analysis on the association between pathologic complete response and triple-negative breast cancer after neoadjuvant chemotherapy.

PubMed

Wu, Kunpeng; Yang, Qiaozhu; Liu, Yi; Wu, Aibing; Yang, Zhixiong

2014-04-15

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer that is characterized by poor prognosis, strong tumor invasion and a high pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC). The pCR rate is a prognostic factor for TNBC. We aimed to evaluate the relationship between pCR and TNBC after NAC and originally tried to identify factors related to achieving pCR for TNBC using a meta-analysis. We systematically searched the literature for pCR and breast cancer after NAC and carefully identified eligibility criteria. The association between pCR and breast cancer subtypes was estimated using Review Manager, while pCR rates for TNBC and non-TNBC were determined using Meta-Analyst. This analysis included a total of 9,460 cases from 27 studies. The summary odds ratio estimating the relationship between pCR and breast cancer subtypes (TNBC vs non-TNBC) was 3.02 (95% confidence interval (CI), 2.66 to 3.42). The TNBC pCR rate was 28.9% (95% CI, 27.0 to 30.8%) and the non-TNBC was 12.5% (95% CI, 11.7 to 13.4%). From subgroup analyses, we identified the factors associated with the highest pCR rates for TNBC. TNBC has a higher pCR rate than non-TNBC. In the NAC setting, these factors of platinum-containing, more than six cycles, four kinds of drugs, 16 weeks' treatment duration and sequential chemotherapy may contribute to increasing the pCR rate.

The development of automaticity in short-term memory search: Item-response learning and category learning.

PubMed

Cao, Rui; Nosofsky, Robert M; Shiffrin, Richard M

2017-05-01

In short-term-memory (STM)-search tasks, observers judge whether a test probe was present in a short list of study items. Here we investigated the long-term learning mechanisms that lead to the highly efficient STM-search performance observed under conditions of consistent-mapping (CM) training, in which targets and foils never switch roles across trials. In item-response learning, subjects learn long-term mappings between individual items and target versus foil responses. In category learning, subjects learn high-level codes corresponding to separate sets of items and learn to attach old versus new responses to these category codes. To distinguish between these 2 forms of learning, we tested subjects in categorized varied mapping (CV) conditions: There were 2 distinct categories of items, but the assignment of categories to target versus foil responses varied across trials. In cases involving arbitrary categories, CV performance closely resembled standard varied-mapping performance without categories and departed dramatically from CM performance, supporting the item-response-learning hypothesis. In cases involving prelearned categories, CV performance resembled CM performance, as long as there was sufficient practice or steps taken to reduce trial-to-trial category-switching costs. This pattern of results supports the category-coding hypothesis for sufficiently well-learned categories. Thus, item-response learning occurs rapidly and is used early in CM training; category learning is much slower but is eventually adopted and is used to increase the efficiency of search beyond that available from item-response learning. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Translation, Cross-cultural Adaptation and Psychometric Validation of the Korean-Language Cardiac Rehabilitation Barriers Scale (CRBS-K).

PubMed

Baek, Sora; Park, Hee-Won; Lee, Yookyung; Grace, Sherry L; Kim, Won-Seok

2017-10-01

To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (p<0.01). The Korean version of CRBS has demonstrated face, content and criterion validity, suggesting it may be useful for assessing barriers to CR utilization in Korea.

Developing a short version of the Toronto Structured Interview for Alexithymia using item response theory.

PubMed

Sekely, Angela; Taylor, Graeme J; Bagby, R Michael

2018-03-17

The Toronto Structured Interview for Alexithymia (TSIA) was developed to provide a structured interview method for assessing alexithymia. One drawback of this instrument is the amount of time it takes to administer and score. The current study used item response theory (IRT) methods to analyze data from a large heterogeneous multi-language sample (N = 842) to investigate whether a subset of items could be selected to create a short version of the instrument. Samejima's (1969) graded response model was used to fit the item responses. Items providing maximum information were retained in the short model, resulting in the elimination of 12-items from the original 24-items. Despite the 50% reduction in the number of items, 65.22% of the information was retained. Further studies are needed to validate the short version. A short version of the TSIA is potentially of practical value to clinicians and researchers with time constraints. Copyright © 2018. Published by Elsevier B.V.

Contextual behavior and neural circuits

PubMed Central

Lee, Inah; Lee, Choong-Hee

2013-01-01

Animals including humans engage in goal-directed behavior flexibly in response to items and their background, which is called contextual behavior in this review. Although the concept of context has long been studied, there are differences among researchers in defining and experimenting with the concept. The current review aims to provide a categorical framework within which not only the neural mechanisms of contextual information processing but also the contextual behavior can be studied in more concrete ways. For this purpose, we categorize contextual behavior into three subcategories as follows by considering the types of interactions among context, item, and response: contextual response selection, contextual item selection, and contextual item–response selection. Contextual response selection refers to the animal emitting different types of responses to the same item depending on the context in the background. Contextual item selection occurs when there are multiple items that need to be chosen in a contextual manner. Finally, when multiple items and multiple contexts are involved, contextual item–response selection takes place whereby the animal either chooses an item or inhibits such a response depending on item–context paired association. The literature suggests that the rhinal cortical regions and the hippocampal formation play key roles in mnemonically categorizing and recognizing contextual representations and the associated items. In addition, it appears that the fronto-striatal cortical loops in connection with the contextual information-processing areas critically control the flexible deployment of adaptive action sets and motor responses for maximizing goals. We suggest that contextual information processing should be investigated in experimental settings where contextual stimuli and resulting behaviors are clearly defined and measurable, considering the dynamic top-down and bottom-up interactions among the neural systems for contextual behavior. PMID:23675321

Item Response Theory Analysis of the Psychopathic Personality Inventory-Revised.

PubMed

Eichenbaum, Alexander E; Marcus, David K; French, Brian F

2017-06-01

This study examined item and scale functioning in the Psychopathic Personality Inventory-Revised (PPI-R) using an item response theory analysis. PPI-R protocols from 1,052 college student participants (348 male, 704 female) were analyzed. Analyses were conducted on the 131 self-report items comprising the PPI-R's eight content scales, using a graded response model. Scales collected a majority of their information about respondents possessing higher than average levels of the traits being measured. Each scale contained at least some items that evidenced limited ability to differentiate between respondents with differing levels of the trait being measured. Moreover, 80 items (61.1%) yielded significantly different responses between men and women presumably possessing similar levels of the trait being measured. Item performance was also influenced by the scoring format (directly scored vs. reverse-scored) of the items. Overall, the results suggest that the PPI-R, despite identifying psychopathic personality traits in individuals possessing high levels of those traits, may not identify these traits equally well for men and women, and scores are likely influenced by the scoring format of the individual item and scale.

Modeling Cr-to-Tm and Cr-to-Tm-to-Ho energy transfer in YAG crystals

NASA Technical Reports Server (NTRS)

Swetits, John J.

1991-01-01

A systematic analysis of energy transfer processes in crystals of YAG doped with varying concentrations of Cr and Tm is described. Both spectral measurements and measurements of the temporal response to pulsed excitation are used to give independent determinations of the microscopic interaction parameter for Cr to Tm transfer. The different factors in influencing the temperature dependence of the Cr to Tm transfer are discussed. The dependence of the Tm cross-relaxation rate on Tm concentration is determined.

The Effects of Test Length and Sample Size on Item Parameters in Item Response Theory

ERIC Educational Resources Information Center

Sahin, Alper; Anil, Duygu

2017-01-01

This study investigates the effects of sample size and test length on item-parameter estimation in test development utilizing three unidimensional dichotomous models of item response theory (IRT). For this purpose, a real language test comprised of 50 items was administered to 6,288 students. Data from this test was used to obtain data sets of…

Investigating Separate and Concurrent Approaches for Item Parameter Drift in 3PL Item Response Theory Equating

ERIC Educational Resources Information Center

Arce-Ferrer, Alvaro J.; Bulut, Okan

2017-01-01

This study examines separate and concurrent approaches to combine the detection of item parameter drift (IPD) and the estimation of scale transformation coefficients in the context of the common item nonequivalent groups design with the three-parameter item response theory equating. The study uses real and synthetic data sets to compare the two…

Item Response Theory with Covariates (IRT-C): Assessing Item Recovery and Differential Item Functioning for the Three-Parameter Logistic Model

ERIC Educational Resources Information Center

Tay, Louis; Huang, Qiming; Vermunt, Jeroen K.

2016-01-01

In large-scale testing, the use of multigroup approaches is limited for assessing differential item functioning (DIF) across multiple variables as DIF is examined for each variable separately. In contrast, the item response theory with covariate (IRT-C) procedure can be used to examine DIF across multiple variables (covariates) simultaneously. To…

Numerical Differentiation Methods for Computing Error Covariance Matrices in Item Response Theory Modeling: An Evaluation and a New Proposal

ERIC Educational Resources Information Center

Tian, Wei; Cai, Li; Thissen, David; Xin, Tao

2013-01-01

In item response theory (IRT) modeling, the item parameter error covariance matrix plays a critical role in statistical inference procedures. When item parameters are estimated using the EM algorithm, the parameter error covariance matrix is not an automatic by-product of item calibration. Cai proposed the use of Supplemented EM algorithm for…

Modeling the Severity of Drinking Consequences in First-Year College Women: An Item Response Theory Analysis of the Rutgers Alcohol Problem Index*

PubMed Central

Cohn, Amy M.; Hagman, Brett T.; Graff, Fiona S.; Noel, Nora E.

2011-01-01

Objective: The present study examined the latent continuum of alcohol-related negative consequences among first-year college women using methods from item response theory and classical test theory. Method: Participants (N = 315) were college women in their freshman year who reported consuming any alcohol in the past 90 days and who completed assessments of alcohol consumption and alcohol-related negative consequences using the Rutgers Alcohol Problem Index. Results: Item response theory analyses showed poor model fit for five items identified in the Rutgers Alcohol Problem Index. Two-parameter item response theory logistic models were applied to the remaining 18 items to examine estimates of item difficulty (i.e., severity) and discrimination parameters. The item difficulty parameters ranged from 0.591 to 2.031, and the discrimination parameters ranged from 0.321 to 2.371. Classical test theory analyses indicated that the omission of the five misfit items did not significantly alter the psychometric properties of the construct. Conclusions: Findings suggest that those consequences that had greater severity and discrimination parameters may be used as screening items to identify female problem drinkers at risk for an alcohol use disorder. PMID:22051212

Effects of Cr(III) and CR(VI) on nitrification inhibition as determined by SOUR, function-specific gene expression and 16S rRNA sequence analysis of wastewater nitrifying enrichments

EPA Science Inventory

The effect of Cr(III) and Cr(VI) on ammonia oxidation, the transcriptional responses of functional genes involved in nitrification and changes in 16S rRNA level sequences were examined in nitrifying enrichment cultures. The nitrifying bioreactor was operated as a continuous react...

Generalizability in Item Response Modeling

ERIC Educational Resources Information Center

Briggs, Derek C.; Wilson, Mark

2007-01-01

An approach called generalizability in item response modeling (GIRM) is introduced in this article. The GIRM approach essentially incorporates the sampling model of generalizability theory (GT) into the scaling model of item response theory (IRT) by making distributional assumptions about the relevant measurement facets. By specifying a random…

An Evolutionarily Conserved DOF-CONSTANS Module Controls Plant Photoperiodic Signaling.

PubMed

Lucas-Reina, Eva; Romero-Campero, Francisco J; Romero, José M; Valverde, Federico

2015-06-01

The response to daylength is a crucial process that evolved very early in plant evolution, entitling the early green eukaryote to predict seasonal variability and attune its physiological responses to the environment. The photoperiod responses evolved into the complex signaling pathways that govern the angiosperm floral transition today. The Chlamydomonas reinhardtii DNA-Binding with One Finger (CrDOF) gene controls transcription in a photoperiod-dependent manner, and its misexpression influences algal growth and viability. In short days, CrDOF enhances CrCO expression, a homolog of plant CONSTANS (CO), by direct binding to its promoter, while it reduces the expression of cell division genes in long days independently of CrCO. In Arabidopsis (Arabidopsis thaliana), transgenic plants overexpressing CrDOF show floral delay and reduced expression of the photoperiodic genes CO and FLOWERING LOCUS T. The conservation of the DOF-CO module during plant evolution could be an important clue to understanding diversification by the inheritance of conserved gene toolkits in key developmental programs. © 2015 American Society of Plant Biologists. All Rights Reserved.

Exposure to Particulate Hexavalent Chromium Exacerbates Allergic Asthma Pathology

PubMed Central

Schneider, Brent C.; Constant, Stephanie L.; Patierno, Steven R.; Jurjus, Rosalyn A.; Ceryak, Susan M.

2011-01-01

Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory response in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels. PMID:22178736

Quantifying Local, Response Dependence between Two Polytomous Items Using the Rasch Model

ERIC Educational Resources Information Center

Andrich, David; Humphry, Stephen M.; Marais, Ida

2012-01-01

Models of modern test theory imply statistical independence among responses, generally referred to as "local independence." One violation of local independence occurs when the response to one item governs the response to a subsequent item. Expanding on a formulation of this kind of violation as a process in the dichotomous Rasch model,…

Using Response Times for Item Selection in Adaptive Testing

ERIC Educational Resources Information Center

van der Linden, Wim J.

2008-01-01

Response times on items can be used to improve item selection in adaptive testing provided that a probabilistic model for their distribution is available. In this research, the author used a hierarchical modeling framework with separate first-level models for the responses and response times and a second-level model for the distribution of the…

The Influence of Item Response Indecision on the Self-Directed Search

ERIC Educational Resources Information Center

Sampson, James P., Jr.; Shy, Jonathan D.; Hartley, Sarah Lucas; Reardon, Robert C.; Peterson, Gary W.

2009-01-01

Students (N = 247) responded to Self-Directed Search (SDS) per the standard response format and were also instructed to record a question mark (?) for items about which they were uncertain (item response indecision [IRI]). The initial responses of the 114 participants with a (?) were then reversed and a second SDS summary code was obtained and…

Improving measurement of injection drug risk behavior using item response theory.

PubMed

Janulis, Patrick

2014-03-01

Recent research highlights the multiple steps to preparing and injecting drugs and the resultant viral threats faced by drug users. This research suggests that more sensitive measurement of injection drug HIV risk behavior is required. In addition, growing evidence suggests there are gender differences in injection risk behavior. However, the potential for differential item functioning between genders has not been explored. To explore item response theory as an improved measurement modeling technique that provides empirically justified scaling of injection risk behavior and to examine for potential gender-based differential item functioning. Data is used from three studies in the National Institute on Drug Abuse's Criminal Justice Drug Abuse Treatment Studies. A two-parameter item response theory model was used to scale injection risk behavior and logistic regression was used to examine for differential item functioning. Item fit statistics suggest that item response theory can be used to scale injection risk behavior and these models can provide more sensitive estimates of risk behavior. Additionally, gender-based differential item functioning is present in the current data. Improved measurement of injection risk behavior using item response theory should be encouraged as these models provide increased congruence between construct measurement and the complexity of injection-related HIV risk. Suggestions are made to further improve injection risk behavior measurement. Furthermore, results suggest direct comparisons of composite scores between males and females may be misleading and future work should account for differential item functioning before comparing levels of injection risk behavior.

Measuring sexual orientation in adolescent health surveys: evaluation of eight school-based surveys.

PubMed

Saewyc, Elizabeth M; Bauer, Greta R; Skay, Carol L; Bearinger, Linda H; Resnick, Michael D; Reis, Elizabeth; Murphy, Aileen

2004-10-01

To examine the performance of various items measuring sexual orientation within 8 school-based adolescent health surveys in the United States and Canada from 1986 through 1999. Analyses examined nonresponse and unsure responses to sexual orientation items compared with other survey items, demographic differences in responses, tests for response set bias, and congruence of responses to multiple orientation items; analytical methods included frequencies, contingency tables with Chi-square, and ANOVA with least significant differences (LSD)post hoc tests; all analyses were conducted separately by gender. In all surveys, nonresponse rates for orientation questions were similar to other sexual questions, but not higher; younger students, immigrants, and students with learning disabilities were more likely to skip items or select "unsure." Sexual behavior items had the lowest nonresponse, but fewer than half of all students reported sexual behavior, limiting its usefulness for indicating orientation. Item placement in the survey, wording, and response set bias all appeared to influence nonresponse and unsure rates. Specific recommendations include standardizing wording across future surveys, and pilot testing items with diverse ages and ethnic groups of teens before use. All three dimensions of orientation should be assessed where possible; when limited to single items, sexual attraction may be the best choice. Specific wording suggestions are offered for future surveys.

Ionic displacement induced ferroelectricity in multiferroic Cr doped ZnO

NASA Astrophysics Data System (ADS)

Tiwari, Jeetendra Kumar; Ali, Nasir; Ghosh, Subhasis

2018-05-01

Cr doped ZnO thin film was grown on quartz substrate using RF magnetron sputtering. Room temperature magnetic and ferroelectric properties of Cr doped ZnO were investigated. It is shown that ZnO becomes ferromagnetic upon Cr doping. It is considered that breaking of centrosymmetry due strain developed by doping of Cr should be responsible for the ferroelectricity. These films were characterized by X-ray diffraction (XRD), which shows that the films possess crystalline structure with preferred orientation along the (002) crystal plane and there is no extra peak due to Cr i.e. single phase.

Predicting response to primary chemotherapy: gene expression profiling of paraffin-embedded core biopsy tissue.

PubMed

Mina, Lida; Soule, Sharon E; Badve, Sunil; Baehner, Fredrick L; Baker, Joffre; Cronin, Maureen; Watson, Drew; Liu, Mei-Lan; Sledge, George W; Shak, Steve; Miller, Kathy D

2007-06-01

Primary chemotherapy provides an ideal opportunity to correlate gene expression with response to treatment. We used paraffin-embedded core biopsies from a completed phase II trial to identify genes that correlate with response to primary chemotherapy. Patients with newly diagnosed stage II or III breast cancer were treated with sequential doxorubicin 75 mg/M2 q2 wks x 3 and docetaxel 40 mg/M2 weekly x 6; treatment order was randomly assigned. Pretreatment core biopsy samples were interrogated for genes that might correlate with pathologic complete response (pCR). In addition to the individual genes, the correlation of the Oncotype DX Recurrence Score with pCR was examined. Of 70 patients enrolled in the parent trial, core biopsies samples with sufficient RNA for gene analyses were available from 45 patients; 9 (20%) had inflammatory breast cancer (IBC). Six (14%) patients achieved a pCR. Twenty-two of the 274 candidate genes assessed correlated with pCR (p < 0.05). Genes correlating with pCR could be grouped into three large clusters: angiogenesis-related genes, proliferation related genes, and invasion-related genes. Expression of estrogen receptor (ER)-related genes and Recurrence Score did not correlate with pCR. In an exploratory analysis we compared gene expression in IBC to non-inflammatory breast cancer; twenty-four (9%) of the genes were differentially expressed (p < 0.05), 5 were upregulated and 19 were downregulated in IBC. Gene expression analysis on core biopsy samples is feasible and identifies candidate genes that correlate with pCR to primary chemotherapy. Gene expression in IBC differs significantly from noninflammatory breast cancer.

Over-Expression of Superoxide Dismutase Ameliorates Cr(VI) Induced Adverse Effects via Modulating Cellular Immune System of Drosophila melanogaster

PubMed Central

Pragya, Prakash; Shukla, Arvind Kumar; Murthy, Ramesh Chandra; Abdin, Malik Zainul; Kar Chowdhuri, Debapratim

2014-01-01

The evolutionarily conserved innate immune system plays critical role for maintaining the health of an organism. However, a number of environmental chemicals including metals are known to exert adverse effects on immune system. The present study assessed the in vivo effect of a major environmental chemical, Cr(VI), on cellular immune response using Drosophila melanogaster and subsequently the protective role of superoxide dismutase (SOD) based on the comparable performance of the tested anti-oxidant enzymes. The immuno-modulatory potential of Cr(VI) was demonstrated by observing a significant reduction in the total hemocyte count along with impaired phagocytic activity in exposed organism. Concurrently, a significant increase in the percentage of Annexin V-FITC positive cells, activation of DEVDase activity, generation of free radical species along with inhibition of anti-oxidant enzyme activities was observed in the hemocytes of exposed organism. In addition, we have shown that ONOO− is primarily responsible for Cr(VI) induced adverse effects on Drosophila hemocytes along with O2 −. While generation of O2 −/ONOO− in Cr(VI) exposed Drosophila hemocytes was found to be responsible for the suppression of Drosophila cellular immune response, Cr(VI) induced alteration was significantly reduced by the over-expression of sod in Drosophila hemocytes. Overall, our results suggest that manipulation of one of the anti-oxidant genes, sod, benefits the organism from Cr(VI) induced alteration in cellular immunity. Further, this study demonstrates the applicability of D. melanogaster to examine the possible effects of environmental chemicals on innate immunity which can be extrapolated to higher organisms due to evolutionary conservation of innate immune system between Drosophila and mammals. PMID:24505420

[18F]fluoro-2-deoxyglucose-positron emission tomography for the assessment of histopathological response after preoperative chemoradiotherapy in advanced oral squamous cell carcinoma.

PubMed

Shimomura, Hiroyuki; Sasahira, Tomonori; Yamanaka, Yasutsugu; Kurihara, Miyako; Imai, Yuichiro; Tamaki, Shigehiro; Yamakawa, Nobuhiro; Shirone, Norihisa; Hasegawa, Masatoshi; Kuniyasu, Hiroki; Kirita, Tadaaki

2015-04-01

[(18)F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC). Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed. Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001). Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.

[Phase II study of YNK01 (1-beta-D-arabinofuranosylcytosine-5'-stearylphosphate) on hematological malignancies].

PubMed

Tatsumi, N; Yamada, K; Ohshima, T; Nakamura, T; Ohno, R; Masaoka, T; Kimura, I; Kimura, K

1990-12-01

Phase II study of YNK01 (1-beta-D-arabinofuranosylcytosine-5'-stearylphosphate), a derivative of cytosine arabinoside, on hematological malignancies was conducted by multi-institutional cooperative group. YNK01 was administered orally at dose of 100-300 mg/body/day for more than 2 weeks. The number of registered and evaluated patients were 211 and 156, respectively. Of 23 patients with acute myelogeneous leukemia (AML), 2 complete response (CR), one partial response (PR) were observed (CR + PR: 13.0%). Hypoplastic leukemia (1/4: 25%), acute unclassified leukemia (1/1: 100%). Of 45 patients with MDS, 2CRs, 6 good response (GR) and 5PRs were observed (CR + PR: 28.9%). AML developing after a prior history of MDS (5/17: 29.4%), CML-BC (2/9: 22.2%). Of 19 patients with CML, 9 achieved CR, 3 achieved PR (63.2%). Of 11 patients with polycythemia vera, 4 achieved CR, 5 achieved PR (81.8%). Of 6 patients with essential thrombocytosis, 2 achieved CR, one achieved PR (50%). The major adverse effects included gastrointestinal toxicities such as nausea, vomiting, anorexia, diarrhea, and elevation of GOT and GPT which were tolerable and reversible. This study indicates that YNK01 is a useful agent against acute leukemia and MDS, especially RAEB, RAEB in T, CMMoL.

The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways.

PubMed

Derous, Davina; Mitchell, Sharon E; Green, Cara L; Chen, Luonan; Han, Jing-Dong J; Wang, Yingchun; Promislow, Daniel E L; Lusseau, David; Speakman, John R; Douglas, Alex

2016-04-01

Food intake and circadian rhythms are regulated by hypothalamic neuropeptides and circulating hormones, which could mediate the anti-ageing effect of calorie restriction (CR). We tested whether these two signaling pathways mediate CR by quantifying hypothalamic transcripts of male C57BL/6 mice exposed to graded levels of CR (10 % to 40 %) for 3 months. We found that the graded CR manipulation resulted in upregulation of core circadian rhythm genes, which correlated negatively with circulating levels of leptin, insulin-like growth factor 1 (IGF-1), insulin, and tumor necrosis factor alpha (TNF-α). In addition, key components in the hunger signaling pathway were expressed in a manner reflecting elevated hunger at greater levels of restriction, and which also correlated negatively with circulating levels of insulin, TNF-α, leptin and IGF-1. Lastly, phenotypes, such as food anticipatory activity and body temperature, were associated with expression levels of both hunger genes and core clock genes. Our results suggest modulation of the hunger and circadian signaling pathways in response to altered levels of circulating hormones, that are themselves downstream of morphological changes resulting from CR treatment, may be important elements in the response to CR, driving some of the key phenotypic outcomes.

The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways

PubMed Central

Green, Cara L.; Chen, Luonan; Han, Jing‐Dong J.; Wang, Yingchun; Promislow, Daniel E.L.; Lusseau, David; Speakman, John R.; Douglas, Alex

2016-01-01

Food intake and circadian rhythms are regulated by hypothalamic neuropeptides and circulating hormones, which could mediate the anti‐ageing effect of calorie restriction (CR). We tested whether these two signaling pathways mediate CR by quantifying hypothalamic transcripts of male C57BL/6 mice exposed to graded levels of CR (10 % to 40 %) for 3 months. We found that the graded CR manipulation resulted in upregulation of core circadian rhythm genes, which correlated negatively with circulating levels of leptin, insulin‐like growth factor 1 (IGF‐1), insulin, and tumor necrosis factor alpha (TNF‐α). In addition, key components in the hunger signaling pathway were expressed in a manner reflecting elevated hunger at greater levels of restriction, and which also correlated negatively with circulating levels of insulin, TNF‐α, leptin and IGF‐1. Lastly, phenotypes, such as food anticipatory activity and body temperature, were associated with expression levels of both hunger genes and core clock genes. Our results suggest modulation of the hunger and circadian signaling pathways in response to altered levels of circulating hormones, that are themselves downstream of morphological changes resulting from CR treatment, may be important elements in the response to CR, driving some of the key phenotypic outcomes. PMID:26945906

Interaction of growth hormone receptor/binding protein gene disruption and caloric restriction for insulin sensitivity and attenuated aging

PubMed Central

Arum, Oge; Saleh, Jamal; Boparai, Ravneet; Turner, Jeremy; Kopchick, John; Khardori, Romesh; Bartke, Andrzej

2014-01-01

The correlation of physiological sensitivity to insulin ( vis-à-vis glycemic regulation) and longevity is extensively established, creating a justifiable gerontological interest on whether insulin sensitivity is causative, or even predictive, of some or all phenotypes of slowed senescence (including longevity). The growth hormone receptor/ binding protein gene-disrupted (GHR-KO) mouse is the most extensively investigated insulin-sensitive, attenuated aging model. It was reported that, in a manner divergent from similar mutants, GHR-KO mice fail to respond to caloric restriction (CR) by altering their insulin sensitivity. We hypothesized that maximized insulin responsiveness is what causes GHR-KO mice to exhibit a suppressed survivorship response to dietary (including caloric) restriction; and attempted to refute this hypothesis by assessing the effects of CR on GHR-KO mice for varied slow-aging-associated phenotypes. In contrast to previous reports, we found GHR-KO mice on CR to be less responsive than their ad libitum (A.L.) counterparts to the hypoglycemia-inducing effects of insulin. Further, CR had negligible effects on the metabolism or cognition of GHR-KO mice. Therefore, our data suggest that the effects of CR on the insulin sensitivity of GHR-KO mice do not concur with the effects of CR on the aging of GHR-KO mice. PMID:25789159

Weight Changes and Metabolic Outcomes in Calorie-Restricted Obese Mice Fed High-Fat Diets Containing Corn or Flaxseed Oil: Physiological Role of Sugar Replacement with Polyphenol-Rich Grape.

PubMed

Ansar, Hastimansooreh; Zamaninour, Negar; Djazayery, Abolghassem; Pishva, Hamideh; Vafa, Mohammadreza; Mazaheri Nezhad Fard, Ramin; Dilmaghanian, Aydin; Mirzaei, Khadijeh; Shidfar, Farzad

2017-08-01

Because diet components are important during dieting in obesity treatment, we examined possible beneficial effects of substituting corn oil and sugar with flaxseed oil and grape in calorie-restricted high-fat diets on weight changes as well as improvement in some metabolic markers and related gene expression. Seventy-five C57BL/6J male mice were given free access to a high-fat (36% of energy from fat) diet containing corn oil plus sugar (CO + S). After 11 weeks, 15 mice were sacrificed and another 60 were divided among 4 high-fat diet groups with 30% calorie restriction (CR) for the next 12 weeks. The diets contained corn oil (CO) or flaxseed oil (FO) with sugar (S) or grape (G). Despite CR, a weight loss trend was observed only during the first 4 weeks in all groups. CR did not significantly increase SIRT1 gene expression. Higher liver weight was observed in mice consuming FO (p < 0.05). Proliferator-activated receptor gamma (PPARγ) expression decreased in FO + G-CR significantly and even with a reduction of adiposity and higher adiponectin levels, fasting blood sugar (FBS) was significantly higher than in CO + G-CR. Grape intake increased Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression and decreased insulin resistance in CO + G-CR. Sugar replacement with polyphenol-rich grape along with CR improved glucose homeostasis, and substituting corn oil with flaxseed oil in obese mice reduced fat mass, but even with no change in adiponectin levels it could not decrease insulin resistance. However, none of the food item combinations facilitated weight reduction in the long-term CR. Therefore, regardless of the total calorie intake, different diet components and fat contents may have unexpected effects on metabolic regulation.

Long-term effects of cardiac rehabilitation in elderly individuals with stable coronary artery disease.

PubMed

Mandic, Sandra; Stevens, Emily; Hodge, Claire; Brown, Casey; Walker, Robert; Body, Dianne; Barclay, Leanne; Nye, Edwin R; Williams, Michael J A

2016-01-01

To compare exercise capacity and cardiovascular response to exercise in elderly individuals with coronary artery disease (CAD) who attend ongoing community-based maintenance cardiac rehabilitation (CR) versus age- and gender-matched healthy "very active" (HVA; ≥ 2000 kcal/week) and healthy "less active" (HLA; <2000 kcal/week) individuals. Sixty-three participants (age: 72.3 ± 5.1 years; 62% men; n = 21 per group) completed the following assessments: (1) symptom-limited graded exercise test with expired gas analysis and bioimpedance assessment of cardiovascular function during exercise; (2) walking tests; (3) physical function; (4) anthropometry and (5) 12-month physical activity recall. The CR group achieved 98% (range: 73-154%) of age- and gender-predicted peak oxygen consumption for healthy individuals. Peak oxygen consumption was lower in CR compared to HVA but not HLA group (VO2peak: CR: 19.0 ± 4.5, HVA: 23.7 ± 2.9, HLA: 20.7 ± 4.7 ml ·kg(-1)ċmin(-1), p = 0.001 versus HVA; p = 0.390 versus HLA). Peak heart rate was lower in CR compared to both HVA and HLA. Walking test results and cardiovascular and physical function were not different between the groups. Elderly individuals with CAD participating in maintenance CR have similar exercise capacity and cardiorespiratory response to exercise compared to their age- and gender-matched less active healthy peers. The findings support referral of elderly patients to community-based CR. Fitness benefits of long-term maintenance cardiac rehabilitation (CR) programs remain unknown. Elderly individuals with coronary artery disease participating in maintenance CR have exercise capacity and cardiorespiratory response to exercise similar to their less active healthy peers. Maintenance CR may play an important role prolonging independent living in elderly individuals.

Comparison of Integrated Testlet and Constructed-Response Question Formats

ERIC Educational Resources Information Center

Slepkov, Aaron D.; Shiell, Ralph C.

2014-01-01

Constructed-response (CR) questions are a mainstay of introductory physics textbooks and exams. However, because of the time, cost, and scoring reliability constraints associated with this format, CR questions are being increasingly replaced by multiple-choice (MC) questions in formal exams. The integrated testlet (IT) is a recently developed…

The Development and Validation of a Rapid Assessment Tool of Primary Care in China

PubMed Central

Mei, Jie; Liang, Yuan; Shi, LeiYu; Zhao, JingGe; Wang, YuTan; Kuang, Li

2016-01-01

Introduction. With Chinese health care reform increasingly emphasizing the importance of primary care, the need for a tool to evaluate primary care performance and service delivery is clear. This study presents a methodology for a rapid assessment of primary care organizations and service delivery in China. Methods. The study translated and adapted the Primary Care Assessment Tool-Adult Edition (PCAT-AE) into a Chinese version to measure core dimensions of primary care, namely, first contact, continuity, comprehensiveness, and coordination. A cross-sectional survey was conducted to assess the validity and reliability of the Chinese Rapid Primary Care Assessment Tool (CR-PCAT). Eight community health centers in Guangdong province have been selected to participate in the survey. Results. A total of 1465 effective samples were included for data analysis. Eight items were eliminated following principal component analysis and reliability testing. The principal component analysis extracted five multiple-item scales (first contact utilization, first contact accessibility, ongoing care, comprehensiveness, and coordination). The tests of scaling assumptions were basically met. Conclusion. The standard psychometric evaluation indicates that the scales have achieved relatively good reliability and validity. The CR-PCAT provides a rapid and reliable measure of four core dimensions of primary care, which could be applied in various scenarios. PMID:26885509

Psychoemotional Features of a Doubtful Disorder: Functional Dyspepsia

PubMed Central

Dragos, D; Ionescu, O; Micut, R; Ojog, DG; Tanasescu, MD

2012-01-01

Objective. To delineate the psychological profile of individuals prone to FD-like symptoms (FDLS). Method. A triple questionnaire of 614 items (including psychological and medical ones) was given to 10192 respondents, the results were analyzed by means of Cronbach alpha, and Chi square test, together with an ad-hoc designed method that implied ranking and outliers detecting. Results and conclusions. FDLS appears to be an accompanying feature of many (if not most) human emotions and are more frequent in anxious, timid, pessimistic, discontent, irascible, tense, success-doubting, unexpected-dreading individuals, bothered by persistent thoughts and tormented by the professional requirements and the lack of time. A higher degree of specificity might have: chiefly fear of failure, susceptibility, and tension, secondarily emotivity, fear of unpredictable events, sense of insufficient time, preoccupation with authority factors, and tendency to endure unacceptable situations, and also faulty patience and lack of punctuality. Rumination appears to be the psychological tendency most strongly associated with FD. Nocturnal epigastric pain seems to indicate a submissive nature but a rather responsibilities-free childhood, while early satiety is associated with inclination to work and responsibility and preoccupation with self-image. The superposition of FD symptoms with biliary and esophageal symptoms cast a doubt over the distinctness and even the materiality of the various functional digestive disorders. Abbreviations: ChiSq = chi-square; CrA = Cronbach alpha; OdRa = odds ratio; OdRaCL = OdRa confidence limits; E = exponential (for the sake of legibility we have used the exponential notation throughout this article; i.e. 4E-28 = 4×10-28); ErrProb = probability of error; SS = statistically significant; SD = standard deviation; a / m = the calculations were done by taking into account the average/ maximal score; P / M = psychological / medical category; PaMm / PmMa / PmMm / PaMa = the calculations were done by taking into account the average score for the PsyCt and the maximal score for the MedCt / the maximal score for PsyCt and the average score for the MedCt / and the maximal score for both / and the average score for both; R = the calculations were done for the FD_res category. FD = functional dyspepsia; FD_res / FD_ext = restricted / extended variant of the group of FD items; FDCt = FD category; FDLS = FD-like symptoms; MedCt / MedIt = medical category / item; PsyCt / PsyIt = psychological category / item; PMID:23144666

Reliability, agreement, and responsiveness of a 6-minute walk/run test in patients with heart disease.

PubMed

Berghmans, Danielle D; Lenssen, Antoine F; Bastiaenen, Carolien H; Ilhan, Mustafa; Lencer, Nicole H; Roox, George M

2013-02-01

The 6-minute walk test (6 MWT) is widely used to assess exercise tolerance in cardiac rehabilitation (CR). However, previous research shows it to be insufficiently responsive, especially for patients with a relatively high maximal exercise tolerance at baseline. We therefore designed a 6-minute walk/run test (6 MWRT), which has the same duration as the 6 MWT but allows running. The objective of this study was to determine the test-retest reproducibility and responsiveness of this 6 MWRT. Responsiveness was investigated in a prospective cohort study among a group of patients entering CR at Maastricht University Medical Center, with a cross-sectional part to assess the test-retest reproducibility. Test-retest reproducibility (reliability and agreement) was investigated using the intraclass correlation (ICC) and a Bland-Altman plot of two measurements implemented in the first week of rehabilitation. Responsiveness of the 6 MWT and the 6 MWRT was calculated using the standard response mean (SRM) over a 6-week period. The first reproducibility analysis included 34 patients, the second 22 patients. The ICCs were 0.935 and 0.906, respectively, with limits of agreement of ± 79 and ± 61 m. The responsiveness analysis included 27 patients. The SRM values were 0.83 for the 6 MWT and 0.71 for the 6 MWRT. Although the 6 MWRT is a reproducible test in CR, its responsiveness is not superior to that of the 6 MWT. We therefore prefer the conventional 6 MWT as an evaluative measurement in CR and advise against using the 6 MWRT as (evaluative) measurement in CR for this purpose.

Outcomes of Hispanic women with lymph-node positive, HER2 positive breast cancer treated with neoadjuvant chemotherapy and trastuzumab in Mexico.

PubMed

Villarreal-Garza, Cynthia; Soto-Perez-de-Celis, Enrique; Sifuentes, Erika; Ruano, Santiago; Baez-Revueltas, Berenice; Lara-Medina, Fernando; Arce-Salinas, Claudia; Alvarado-Miranda, Alberto; Chavarri-Guerra, Yanin; Caro-Sanchez, Claudia; Castañeda-Soto, Noel; Bargallo-Rocha, Enrique; Mohar, Alejandro

2015-06-01

Evidence regarding the outcomes of Hispanic women with breast cancer is lacking. We analyzed women with HER2+ disease treated with trastuzumab-based neoadjuvant chemotherapy in Mexico. 244 patients were included. Outcomes were compared between patients who achieved pathologic complete response (pCR) (n = 119), or less than pCR (n = 125). Patients with noninvasive (ypT0/is, ypN0) residual disease were also analyzed. 119 (48.8%) patients achieved pCR. pCR was the only factor associated with improved 3 year survival (98.1% vs 92.3%: P = 0.02). Survival was better in patients with ypT0/is, ypN0 response than in those with residual invasive disease (p < 0.01). 3 year survival was 98.1% for patients with pCR and 92.6% for patients with ypTis, ypN0 response (p = 0.64). Response rates to trastuzumab based neoadjuvant chemotherapy in Hispanics mimic that of other ethnic groups. This underlines the fact that access to treatment, rather than ethnicity, is the main prognostic factor in this population. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of a General Polytomous Testlet Model to the Reading Section of a Large-Scale English Language Assessment. Research Report. ETS RR-10-21

ERIC Educational Resources Information Center

Li, Yanmei; Li, Shuhong; Wang, Lin

2010-01-01

Many standardized educational tests include groups of items based on a common stimulus, known as "testlets". Standard unidimensional item response theory (IRT) models are commonly used to model examinees' responses to testlet items. However, it is known that local dependence among testlet items can lead to biased item parameter estimates…

Assessing the Utility of Item Response Theory Models: Differential Item Functioning.

ERIC Educational Resources Information Center

Scheuneman, Janice Dowd

The current status of item response theory (IRT) is discussed. Several IRT methods exist for assessing whether an item is biased. Focus is on methods proposed by L. M. Rudner (1975), F. M. Lord (1977), D. Thissen et al. (1988) and R. L. Linn and D. Harnisch (1981). Rudner suggested a measure of the area lying between the two item characteristic…

A Comparison of the One-, the Modified Three-, and the Three-Parameter Item Response Theory Models in the Test Development Item Selection Process.

ERIC Educational Resources Information Center

Eignor, Daniel R.; Douglass, James B.

This paper attempts to provide some initial information about the use of a variety of item response theory (IRT) models in the item selection process; its purpose is to compare the information curves derived from the selection of items characterized by several different IRT models and their associated parameter estimation programs. These…

Dopamine dependency for acquisition and performance of Pavlovian conditioned response

PubMed Central

Darvas, Martin; Wunsch, Amanda M.; Gibbs, Jeffrey T.; Palmiter, Richard D.

2014-01-01

During Pavlovian conditioning, pairing of a neutral conditioned stimulus (CS) with a reward leads to conditioned reward-approach responses (CRs) that are elicited by presentation of the CS. CR behaviors can be sign tracking, in which animals engage the CS, or goal tracking, in which animals go to the reward location. We investigated CR behaviors in mice with only ∼5% of normal dopamine in the striatum using a Pavlovian conditioning paradigm. These mice had severely impaired acquisition of the CR, which was ameliorated by pharmacological restoration of dopamine synthesis with l-dopa. Surprisingly, after they had learned the CR, its expression decayed only gradually in following sessions that were conducted without l-dopa treatment. To assess specific contributions of dopamine signaling in the dorsal or ventral striatum, we performed virus-mediated restoration of dopamine synthesis in completely dopamine-deficient (DD) mice. Mice with dopamine signaling only in the dorsal striatum did not acquire a CR, whereas mice with dopamine signaling only in in the ventral striatum acquired a CR. The CR in mice with dopamine signaling only in the dorsal striatum was restored by subjecting the mice to instrumental training in which they had to interact with the CS to obtain rewards. We conclude that dopamine is essential for learning and performance of CR behavior that is predominantly goal tracking. Furthermore, although dopamine signaling in the ventral striatum is sufficient to support a CR, dopamine signaling only in the dorsal striatum can also support a CR under certain circumstances. PMID:24550305

Creatine Monohydrate Supplementation Does Not Augment Fitness, Performance, or Body Composition Adaptations in Response to Four Weeks of High-Intensity Interval Training in Young Females.

PubMed

Forbes, Scott C; Sletten, Nathan; Durrer, Cody; Myette-Côté, Étienne; Candow, D; Little, Jonathan P

2017-06-01

High-intensity interval training (HIIT) has been shown to improve cardiorespiratory fitness, performance, body composition, and insulin sensitivity. Creatine (Cr) supplementation may augment responses to HIIT, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of 4 weeks of HIIT (three sessions/week) combined with Cr supplementation in recreationally active females. Seventeen females (age = 23 ± 4 yrs; BMI = 23.4 ± 2.4) were randomly assigned to either Cr (Cr; 0.3 g・kg -1 ・d -1 for 5 d followed by 0.1 g・kg -1 ・d -1 for 23 days; n = 9) or placebo (PLA; n = 8). Before and after the intervention, VO 2peak , ventilatory threshold (VT), time-trial performance, lean body mass and fat mass, and insulin sensitivity were assessed. HIIT improved VO 2peak (Cr = +10.2%; PLA = +8.8%), VT (Cr = +12.7%; PLA = +9.9%), and time-trial performance (Cr = -11.5%; PLA = -11.6%) with no differences between groups (time main effects, all p < .001). There were no changes over time for fat mass (Cr = -0.3%; PLA = +4.3%), whole-body lean mass (Cr = +0.5%; PLA = -0.9%), or insulin resistance (Cr = +3.9%; PLA = +18.7%). In conclusion, HIIT is an effective way to improve cardiorespiratory fitness, VT, and time-trial performance. The addition of Cr to HIIT did not augment improvements in cardiorespiratory fitness, performance or body composition in recreationally active females.

Chromium enhances insulin responsiveness via AMPK.

PubMed

Hoffman, Nolan J; Penque, Brent A; Habegger, Kirk M; Sealls, Whitney; Tackett, Lixuan; Elmendorf, Jeffrey S

2014-05-01

Trivalent chromium (Cr(3+)) is known to improve glucose homeostasis. Cr(3+) has been shown to improve plasma membrane-based aspects of glucose transporter GLUT4 regulation and increase activity of the cellular energy sensor 5' AMP-activated protein kinase (AMPK). However, the mechanism(s) by which Cr(3+) improves insulin responsiveness and whether AMPK mediates this action is not known. In this study we tested if Cr(3+) protected against physiological hyperinsulinemia-induced plasma membrane cholesterol accumulation, cortical filamentous actin (F-actin) loss and insulin resistance in L6 skeletal muscle myotubes. In addition, we performed mechanistic studies to test our hypothesis that AMPK mediates the effects of Cr(3+) on GLUT4 and glucose transport regulation. Hyperinsulinemia-induced insulin-resistant L6 myotubes displayed excess membrane cholesterol and diminished cortical F-actin essential for effective glucose transport regulation. These membrane and cytoskeletal abnormalities were associated with defects in insulin-stimulated GLUT4 translocation and glucose transport. Supplementing the culture medium with pharmacologically relevant doses of Cr(3+) in the picolinate form (CrPic) protected against membrane cholesterol accumulation, F-actin loss, GLUT4 dysregulation and glucose transport dysfunction. Insulin signaling was neither impaired by hyperinsulinemic conditions nor enhanced by CrPic, whereas CrPic increased AMPK signaling. Mechanistically, siRNA-mediated depletion of AMPK abolished the protective effects of CrPic against GLUT4 and glucose transport dysregulation. Together these findings suggest that the micronutrient Cr(3+), via increasing AMPK activity, positively impacts skeletal muscle cell insulin sensitivity and glucose transport regulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Item Response Modeling of Multivariate Count Data with Zero Inflation, Maximum Inflation, and Heaping

ERIC Educational Resources Information Center

Magnus, Brooke E.; Thissen, David

2017-01-01

Questionnaires that include items eliciting count responses are becoming increasingly common in psychology. This study proposes methodological techniques to overcome some of the challenges associated with analyzing multivariate item response data that exhibit zero inflation, maximum inflation, and heaping at preferred digits. The modeling…

Nested Logit Models for Multiple-Choice Item Response Data

ERIC Educational Resources Information Center

Suh, Youngsuk; Bolt, Daniel M.

2010-01-01

Nested logit item response models for multiple-choice data are presented. Relative to previous models, the new models are suggested to provide a better approximation to multiple-choice items where the application of a solution strategy precedes consideration of response options. In practice, the models also accommodate collapsibility across all…

The Dutch Identity: A New Tool for the Study of Item Response Models.

ERIC Educational Resources Information Center

Holland, Paul W.

1990-01-01

The Dutch Identity is presented as a useful tool for expressing the basic equations of item response models that relate the manifest probabilities to the item response functions and the latent trait distribution. Ways in which the identity may be exploited are suggested and illustrated. (SLD)

Hungry for life: How the arcuate nucleus and neuropeptide Y may play a critical role in mediating the benefits of calorie restriction.

PubMed

Minor, Robin K; Chang, Joy W; de Cabo, Rafael

2009-02-05

Laboratory studies consistently demonstrate extended lifespan in animals on calorie restriction (CR), where total caloric intake is reduced by 10-40% but adequate nutrition is otherwise maintained. CR has been further shown to delay the onset and severity of chronic diseases associated with aging such as cancer, and to extend the functional health span of important faculties like cognition. Less understood are the underlying mechanisms through which CR might act to induce such alterations. One theory postulates that CR's beneficial effects are intimately tied to the neuroendocrine response to low energy availability, of which the arcuate nucleus in the hypothalamus plays a pivotal role. Neuropeptide Y (NPY), a neurotransmitter in the front line of the arcuate response to low energy availability, is the primary hunger signal affected by CR and therefore may be a critical mechanism for lifespan extension.

Item response theory analysis of the mechanics baseline test

NASA Astrophysics Data System (ADS)

Cardamone, Caroline N.; Abbott, Jonathan E.; Rayyan, Saif; Seaton, Daniel T.; Pawl, Andrew; Pritchard, David E.

2012-02-01

Item response theory is useful in both the development and evaluation of assessments and in computing standardized measures of student performance. In item response theory, individual parameters (difficulty, discrimination) for each item or question are fit by item response models. These parameters provide a means for evaluating a test and offer a better measure of student skill than a raw test score, because each skill calculation considers not only the number of questions answered correctly, but the individual properties of all questions answered. Here, we present the results from an analysis of the Mechanics Baseline Test given at MIT during 2005-2010. Using the item parameters, we identify questions on the Mechanics Baseline Test that are not effective in discriminating between MIT students of different abilities. We show that a limited subset of the highest quality questions on the Mechanics Baseline Test returns accurate measures of student skill. We compare student skills as determined by item response theory to the more traditional measurement of the raw score and show that a comparable measure of learning gain can be computed.

Sample Invariance of the Structural Equation Model and the Item Response Model: A Case Study.

ERIC Educational Resources Information Center

Breithaupt, Krista; Zumbo, Bruno D.

2002-01-01

Evaluated the sample invariance of item discrimination statistics in a case study using real data, responses of 10 random samples of 500 people to a depression scale. Results lend some support to the hypothesized superiority of a two-parameter item response model over the common form of structural equation modeling, at least when responses are…

A Method for Imputing Response Options for Missing Data on Multiple-Choice Assessments

ERIC Educational Resources Information Center

Wolkowitz, Amanda A.; Skorupski, William P.

2013-01-01

When missing values are present in item response data, there are a number of ways one might impute a correct or incorrect response to a multiple-choice item. There are significantly fewer methods for imputing the actual response option an examinee may have provided if he or she had not omitted the item either purposely or accidentally. This…

Assessing pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review.

PubMed

Ryan, J E; Warrier, S K; Lynch, A C; Heriot, A G

2015-10-01

Pathological complete response to neoadjuvant chemoradiotherapy is found in 20% of patients with rectal cancer undergoing long-course chemoradiotherapy. Some authors have suggested that these patients do not need to undergo surgery and can be managed with careful follow-up, with surgery only used in the event of clinical failure. Widespread adoption of this regimen is limited by the accuracy of methods to confirm a pathological complete response (pCR). A systematic search of PubMed, Medline and Cochrane databases was conducted to identify clinical, histological and radiological features in those patients with rectal cancer who achieved a pCR following chemoradiotherapy. Searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation' and 'tumour response'. After review of title and abstracts, 89 articles addressing the assessment of pCR were identified. Histology and clinical assessment are the most effective methods of assessment of pCR, with histology considered the gold standard. Clinical assessment is limited to low rectal tumours and is open to significant inter-rater variability, while histological examination requires a surgical specimen. Diffusion-weighted MRI and (18) F-fluorodeoxyglucose positron emission tomography/CT demonstrate the greatest potential for the assessment of pCR, but both modalities have limited accuracy. Determination of a pCR is crucial if a nonoperative approach is to be undertaken proactively. Various methods are available, but currently they lack sufficient sensitivity and specificity to define management. This is likely to be an area of further research in the future. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

Accumulation and detoxification dynamics of Chromium and antioxidant responses in juvenile rare minnow, Gobiocypris rarus.

PubMed

Yuan, Cong; Li, Meng; Zheng, Yao; Zhou, Ying; Wu, Feili; Wang, Zaizhao

2017-09-01

Hexavalent chromium (Cr 6+ ) compounds are hazardous via all exposure routes. To explore the dynamics of Cr accumulation and elimination and to reveal the mechanisms underlying detoxification and antioxidation in juvenile Gobiocypris rarus, one-month old G. rarus larvae were exposed to 0.1mgL -1 Cr 6+ for four weeks for accumulation and subsequently placed to clean water for another week for depuration. The contents of Cr were measured weekly in the whole body of G. rarus juveniles. The activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione S-transferase (GST) and glutathione reductase (GR), and contents of glutathione (GSH) and malonaldehyde (MDA), and transcripts of cat, Cu/Zn-sod, Mn-sod, gpx1, gstpi, gr, mt1, nrf2 and uba52 were determined. The results indicated that G. rarus juveniles had a strong ability to resist the Cr accumulation by Cr 6+ exposure and to remove Cr from the body in clean water. In addition, GST and MT proteins may be involved in the detoxification of Cr 6+ . Moreover, Cr 6+ -induced GST detoxification in G. rarus juveniles might be accomplished through the Nrf2-mediated regulation of gene expressions. The antioxidant enzyme systems exhibited a response mechanism of the protective enzymes in organisms when they are subjected to external environmental stress. Two weeks of Cr 6+ treatments could have led to the damage and consecutive degradation of antioxidant enzymes via ubiquitination, and MT proteins could be involved in protecting the activity of these enzymes. The capability of antioxidant enzyme systems to recover from the Cr 6+ -induced damage was strong in G. rarus juveniles after Cr 6+ was removed from the water. Copyright © 2017 Elsevier B.V. All rights reserved.

Minimal Residual Disease Assessment Improves Prediction of Outcome in Patients With Chronic Lymphocytic Leukemia (CLL) Who Achieve Partial Response: Comprehensive Analysis of Two Phase III Studies of the German CLL Study Group.

PubMed

Kovacs, Gabor; Robrecht, Sandra; Fink, Anna Maria; Bahlo, Jasmin; Cramer, Paula; von Tresckow, Julia; Maurer, Christian; Langerbeins, Petra; Fingerle-Rowson, Günter; Ritgen, Matthias; Kneba, Michael; Döhner, Hartmut; Stilgenbauer, Stephan; Klapper, Wolfram; Wendtner, Clemens-Martin; Fischer, Kirsten; Hallek, Michael; Eichhorst, Barbara; Böttcher, Sebastian

2016-11-01

Purpose To determine the value of minimal residual disease (MRD) assessments, together with the evaluation of clinical response in chronic lymphocytic leukemia according to the 2008 International Workshop on Chronic Lymphocytic Leukemia criteria. Patients and Methods Progression-free survival (PFS) and overall survival of 554 patients from two randomized trials of the German CLL Study Group (CLL8: fludarabine and cyclophosphamide [FC] v FC plus rituximab; CLL10: FC plus rituximab v bendamustine plus rituximab) were analyzed according to MRD assessed in peripheral blood at a threshold of 10 -4 and clinical response. The prognostic value of different parameters defining a partial response (PR) was further investigated. Results Patients with MRD-negative complete remission (CR), MRD-negative PR, MRD-positive CR, and MRD-positive PR experienced a median PFS from a landmark at end of treatment of 61 months, 54 months, 35 months, and 21 months, respectively. PFS did not differ significantly between MRD-negative CR and MRD-negative PR; however, PFS was longer for MRD-negative PR than for MRD-positive CR ( P = .048) and for MRD-positive CR compared with MRD-positive PR ( P = .002). Compared with MRD-negative CR, only patients with MRD-positive PR had a significantly shorter overall survival (not reached v 72 months; P = .001), whereas there was no detectable difference for patients with MRD-negative PR or MRD-positive CR ( P = 0.612 and P = 0.853, respectively). Patients with MRD-negative PR who presented with residual splenomegaly had only a similar PFS (63 months) compared with patients with MRD-negative CR (61 months; P = .354), whereas patients with MRD-negative PR with lymphadenopathy showed a shorter PFS (31 months; P < .001). Conclusion MRD quantification allows for improved PFS prediction in both patients who achive PR and CR, which thus supports its application in all responders. In contrast to residual lymphadenopathy, persisting splenomegaly does not impact outcome in patients with MRD-negative PR.

Gender differences in national assessment of educational progress science items: What does i don't know really mean?

NASA Astrophysics Data System (ADS)

Linn, Marcia C.; de Benedictis, Tina; Delucchi, Kevin; Harris, Abigail; Stage, Elizabeth

The National Assessment of Educational Progress Science Assessment has consistently revealed small gender differences on science content items but not on science inquiry items. This assessment differs from others in that respondents can choose I don't know rather than guessing. This paper examines explanations for the gender differences including (a) differential prior instruction, (b) differential response to uncertainty and use of the I don't know response, (c) differential response to figurally presented items, and (d) different attitudes towards science. Of these possible explanations, the first two received support. Females are more likely to use the I don't know response, especially for items with physical science content or masculine themes such as football. To ameliorate this situation we need more effective science instruction and more gender-neutral assessment items.

A Comparison between Discrimination Indices and Item-Response Theory Using the Rasch Model in a Clinical Course Written Examination of a Medical School.

PubMed

Park, Jong Cook; Kim, Kwang Sig

2012-03-01

The reliability of test is determined by each items' characteristics. Item analysis is achieved by classical test theory and item response theory. The purpose of the study was to compare the discrimination indices with item response theory using the Rasch model. Thirty-one 4th-year medical school students participated in the clinical course written examination, which included 22 A-type items and 3 R-type items. Point biserial correlation coefficient (C(pbs)) was compared to method of extreme group (D), biserial correlation coefficient (C(bs)), item-total correlation coefficient (C(it)), and corrected item-total correlation coeffcient (C(cit)). Rasch model was applied to estimate item difficulty and examinee's ability and to calculate item fit statistics using joint maximum likelihood. Explanatory power (r2) of Cpbs is decreased in the following order: C(cit) (1.00), C(it) (0.99), C(bs) (0.94), and D (0.45). The ranges of difficulty logit and standard error and ability logit and standard error were -0.82 to 0.80 and 0.37 to 0.76, -3.69 to 3.19 and 0.45 to 1.03, respectively. Item 9 and 23 have outfit > or =1.3. Student 1, 5, 7, 18, 26, 30, and 32 have fit > or =1.3. C(pbs), C(cit), and C(it) are good discrimination parameters. Rasch model can estimate item difficulty parameter and examinee's ability parameter with standard error. The fit statistics can identify bad items and unpredictable examinee's responses.

Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo.

PubMed

Novelle, Marta G; Davis, Ashley; Price, Nathan L; Ali, Ahmed; Fürer-Galvan, Stefanie; Zhang, Yongqing; Becker, Kevin; Bernier, Michel; de Cabo, Rafael

2015-04-01

Caloric restriction (CR) without malnutrition is one of the most consistent strategies for increasing mean and maximal lifespan and delaying the onset of age-associated diseases. Stress resistance is a common trait of many long-lived mutants and life-extending interventions, including CR. Indeed, better protection against heat shock and other genotoxic insults have helped explain the pro-survival properties of CR. In this study, both in vitro and in vivo responses to heat shock were investigated using two different models of CR. Murine B16F10 melanoma cells treated with serum from CR-fed rats showed lower proliferation, increased tolerance to heat shock and enhanced HSP-70 expression, compared to serum from ad libitum-fed animals. Similar effects were observed in B16F10 cells implanted subcutaneously in male C57BL/6 mice subjected to CR. Microarray analysis identified a number of genes and pathways whose expression profile were similar in both models. These results suggest that the use of an in vitro model could be a good alternative to study the mechanisms by which CR exerts its anti-tumorigenic effects.

Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo

PubMed Central

Novelle, Marta G.; Davis, Ashley; Price, Nathan L.; Ali, Ahmed; Fürer-Galvan, Stefanie; Zhang, Yongqing; Becker, Kevin; Bernier, Michel; de Cabo, Rafael

2015-01-01

Caloric restriction (CR) without malnutrition is one of the most consistent strategies for increasing mean and maximal lifespan and delaying the onset of age-associated diseases. Stress resistance is a common trait of many long-lived mutants and life-extending interventions, including CR. Indeed, better protection against heat shock and other genotoxic insults have helped explain the pro-survival properties of CR. In this study, both in vitro and in vivo responses to heat shock were investigated using two different models of CR. Murine B16F10 melanoma cells treated with serum from CR-fed rats showed lower proliferation, increased tolerance to heat shock and enhanced HSP-70 expression, compared to serum from ad libitum-fed animals. Similar effects were observed in B16F10 cells implanted subcutaneously in male C57BL/6 mice subjected to CR. Microarray analysis identified a number of genes and pathways whose expression profile were similar in both models. These results suggest that the use of an in vitro model could be a good alternative to study the mechanisms by which CR exerts its anti-tumorigenic effects. PMID:25948793

Electronic and optical properties of Cr-, B-doped, and (Cr, B)-codoped SrTiO3

NASA Astrophysics Data System (ADS)

Wu, Jiao; Huang, Wei-Qing; Yang, Ke; Wei, Zeng-Xi; Peng, P.; Huang, Gui-Fang

2017-04-01

Energy band engineering of semiconductors plays a crucial role in exploring high-efficiency visible-light response photocatalysts. Herein, we systematically study the electronic properties and optical response of Cr-, B-doped SrTiO3, and (Cr, B)-codoped SrTiO3 by using first-principles calculations to explore the mechanism for its superior photocatalytic activities in the visible light region. Special emphasis is placed on uncovering the synergy effects of nonmetal B dopant with metal Cr dopant at different cation sites. It is found that the electronic properties and optical absorption of SrTiO3 can be dramatically engineered by mono- or co-doping. In particular, the intermediate levels lying in the bandgap of the codoped SrTiO3 relay on the Cr impurity doped at Sr or Ti cation sites. Moreover, the (Cr@Sr, B@O)-SrTiO3 retains the charge balancing without the generation of unexpected oxygen vacancies, and is more desirable for solar light harvesting due to its higher absorption than others in the entire visible light. The findings can rationalize the available experimental results and are helpful in designing SrTiO3-based photocatalysts with high-efficiency performance.

Using Item Response Theory to Describe the Nonverbal Literacy Assessment (NVLA)

ERIC Educational Resources Information Center

Fleming, Danielle; Wilson, Mark; Ahlgrim-Delzell, Lynn

2018-01-01

The Nonverbal Literacy Assessment (NVLA) is a literacy assessment designed for students with significant intellectual disabilities. The 218-item test was initially examined using confirmatory factor analysis. This method showed that the test worked as expected, but the items loaded onto a single factor. This article uses item response theory to…

Measuring Student Learning with Item Response Theory

ERIC Educational Resources Information Center

Lee, Young-Jin; Palazzo, David J.; Warnakulasooriya, Rasil; Pritchard, David E.

2008-01-01

We investigate short-term learning from hints and feedback in a Web-based physics tutoring system. Both the skill of students and the difficulty and discrimination of items were determined by applying item response theory (IRT) to the first answers of students who are working on for-credit homework items in an introductory Newtonian physics…

Higher-Order Item Response Models for Hierarchical Latent Traits

ERIC Educational Resources Information Center

Huang, Hung-Yu; Wang, Wen-Chung; Chen, Po-Hsi; Su, Chi-Ming

2013-01-01

Many latent traits in the human sciences have a hierarchical structure. This study aimed to develop a new class of higher order item response theory models for hierarchical latent traits that are flexible in accommodating both dichotomous and polytomous items, to estimate both item and person parameters jointly, to allow users to specify…

Evaluating Item Fit for Multidimensional Item Response Models

ERIC Educational Resources Information Center

Zhang, Bo; Stone, Clement A.

2008-01-01

This research examines the utility of the s-x[superscript 2] statistic proposed by Orlando and Thissen (2000) in evaluating item fit for multidimensional item response models. Monte Carlo simulation was conducted to investigate both the Type I error and statistical power of this fit statistic in analyzing two kinds of multidimensional test…

An Item Response Theory Model for Test Bias.

ERIC Educational Resources Information Center

Shealy, Robin; Stout, William

This paper presents a conceptualization of test bias for standardized ability tests which is based on multidimensional, non-parametric, item response theory. An explanation of how individually-biased items can combine through a test score to produce test bias is provided. It is contended that bias, although expressed at the item level, should be…

Analysis test of understanding of vectors with the three-parameter logistic model of item response theory and item response curves technique

NASA Astrophysics Data System (ADS)

Rakkapao, Suttida; Prasitpong, Singha; Arayathanitkul, Kwan

2016-12-01

This study investigated the multiple-choice test of understanding of vectors (TUV), by applying item response theory (IRT). The difficulty, discriminatory, and guessing parameters of the TUV items were fit with the three-parameter logistic model of IRT, using the parscale program. The TUV ability is an ability parameter, here estimated assuming unidimensionality and local independence. Moreover, all distractors of the TUV were analyzed from item response curves (IRC) that represent simplified IRT. Data were gathered on 2392 science and engineering freshmen, from three universities in Thailand. The results revealed IRT analysis to be useful in assessing the test since its item parameters are independent of the ability parameters. The IRT framework reveals item-level information, and indicates appropriate ability ranges for the test. Moreover, the IRC analysis can be used to assess the effectiveness of the test's distractors. Both IRT and IRC approaches reveal test characteristics beyond those revealed by the classical analysis methods of tests. Test developers can apply these methods to diagnose and evaluate the features of items at various ability levels of test takers.

Effects of dietary organic chromium and vitamin C supplementation on performance, immune responses, blood metabolites, and stress status of laying hens subjected to high stocking density.

PubMed

Mirfendereski, E; Jahanian, R

2015-02-01

The present study was carried out to investigate the effects of dietary supplementation of chromium-methionine (CrMet) and vitamin C (VC) on performance, immune response, and stress status of laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 leghorn hens (at 26 wk old) were used in a 2×3×2 factorial arrangement that had 2 cage densities (5 and 7 hens per cage), 3 Cr levels (0, 500, and 1,000 ppb as CrMet), and 2 dietary VC levels (0 and 500 ppm as L-ascorbic acid). The trial lasted for 12 wk. The first 2 wk were for adaptation (26 to 28 wk of age), and the remaining 10 wk served as the main recording period. In addition to performance, immune response to Newcastle disease virus (NDV) was assessed at d 7 and 14 postvaccination. Also, the birds' stress status was evaluated by analyzing appropriate plasma metabolites. The results showed that hens in cages with higher stocking density had lower hen-day egg production, egg mass, and feed intake compared with those in normal density cages (P<0.05). Dietary CrMet supplementation caused significant increases in egg production and egg mass (P<0.01). There were significant Cr × VC interactions related to egg production and feed conversion efficiency (P<0.01); dietary CrMet supplementation was more effective in improving egg production and feed conversion ratio in VC-unsupplemented diets. Although plasma concentrations of triglycerides and high-density lipoproteins were not influenced by dietary treatments, supplemental CrMet decreased plasma cholesterol levels (P<0.05). Plasma insulin and glucose levels of hens kept at a density of 7 hens/cage were significantly higher than those of hens in normal cage density (P<0.01), and dietary CrMet supplementation decreased plasma concentrations of insulin (P<0.001) and glucose (P<0.01), with higher impacts in high stocking density-challenged hens. While high stocking density caused a marked increase in plasma corticosterone (P<0.01), both supplemental CrMet and VC decreased it to near normal levels. There were significant stocking density×Cr interactions related to plasma insulin and corticosterone concentrations (P<0.01); supplemental CrMet was more effective in lowering these hormones in high stocking density-challenged hens. The high stocking density challenge suppressed NDV antibody response (P<0.001), while dietary supplementation of CrMet improved antibody titers against NDV at d 14 post vaccination particularly in hens kept at a density of 7 hens/cage (P<0.01). From the present observations, it can be concluded that CrMet can improve laying performance largely because it alleviates harmful responses to stressful conditions. © 2015 Poultry Science Association Inc.

Chromium in Drinking Water: Sources, Metabolism, and Cancer Risks

PubMed Central

2011-01-01

Drinking water supplies in many geographic areas contain chromium in the +3 and +6 oxidation states. Public health concerns are centered on the presence of hexavalent Cr that is classified as a known human carcinogen via inhalation. Cr(VI) has high environmental mobility and can originate from anthropogenic and natural sources. Acidic environments with high organic content promote the reduction of Cr(VI) to nontoxic Cr(III). The opposite process of Cr(VI) formation from Cr(III) also occurs, particularly in the presence of common minerals containing Mn(IV) oxides. Limited epidemiological evidence for Cr(VI) ingestion is suggestive of elevated risks for stomach cancers. Exposure of animals to Cr(VI) in drinking water induced tumors in the alimentary tract, with linear and supralinear responses in the mouse small intestine. Chromate, the predominant form of Cr(VI) at neutral pH, is taken up by all cells through sulfate channels and is activated nonenzymatically by ubiquitously present ascorbate and small thiols. The most abundant form of DNA damage induced by Cr(VI) is Cr-DNA adducts, which cause mutations and chromosomal breaks. Emerging evidence points to two-way interactions between DNA damage and epigenetic changes that collectively determine the spectrum of genomic rearrangements and profiles of gene expression in tumors. Extensive formation of DNA adducts, clear positivity in genotoxicity assays with high predictive values for carcinogenicity, the shape of tumor–dose responses in mice, and a biological signature of mutagenic carcinogens (multispecies, multisite, and trans-sex tumorigenic potency) strongly support the importance of the DNA-reactive mutagenic mechanisms in carcinogenic effects of Cr(VI). Bioavailability results and kinetic considerations suggest that 10–20% of ingested low-dose Cr(VI) escapes human gastric inactivation. The directly mutagenic mode of action and the incompleteness of gastric detoxification argue against a threshold in low-dose extrapolation of cancer risk for ingested Cr(VI). PMID:21766833

Judgment and judgment latency for freedom and responsibility relatedness as a function of subtle linguistic variations.

PubMed

Wilkerson, Keith; McGahan, Joseph R; Stevens, Rick; Williamson, David; Low, Jean

2009-12-01

The goal of this study was to determine whether differential response formats to covariation problems influence corresponding response latencies. The authors provided participants with 3 trials of 16 statements addressing positive and negative relations between freedom and responsibility. The authors framed half of the items around responsibility given freedom and the other half around freedom given responsibility. Response formats comprised true-false, agree-disagree, and yes-no answers as a between-participants factor. Results indicated that the manipulation of response format did not affect latencies. However, latencies differed according to the framing of the items. For items framed around freedom given responsibility, latencies were shorter. In addition, participants were more likely to report a positive relation between freedom and responsibility when items were framed around freedom given responsibility. The authors discuss implications relative to previous research in this area and give recommendations for future research.

Psychometric properties of the Chinese version of resilience scale specific to cancer: an item response theory analysis.

PubMed

Ye, Zeng Jie; Liang, Mu Zi; Zhang, Hao Wei; Li, Peng Fei; Ouyang, Xue Ren; Yu, Yuan Liang; Liu, Mei Ling; Qiu, Hong Zhong

2018-06-01

Classic theory test has been used to develop and validate the 25-item Resilience Scale Specific to Cancer (RS-SC) in Chinese patients with cancer. This study was designed to provide additional information about the discriminative value of the individual items tested with an item response theory analysis. A two-parameter graded response model was performed to examine whether any of the items of the RS-SC exhibited problems with the ordering and steps of thresholds, as well as the ability of items to discriminate patients with different resilience levels using item characteristic curves. A sample of 214 Chinese patients with cancer diagnosis was analyzed. The established three-dimension structure of the RS-SC was confirmed. Several items showed problematic thresholds or discrimination ability and require further revision. Some problematic items should be refined and a short-form of RS-SC maybe feasible in clinical settings in order to reduce burden on patients. However, the generalizability of these findings warrants further investigations.

Reinstatement of an Extinguished Fear Conditioned Response in Infant Rats

ERIC Educational Resources Information Center

Revillo, Damian A.; Trebucq, Gastón; Paglini, Maria G.; Arias, Carlos

2016-01-01

Although it is currently accepted that the extinction effect reflects new context-dependent learning, this is not so clear during infancy, because some studies did not find recovery of the extinguished conditioned response (CR) in rodents during this ontogenetic stage. However, recent studies have shown the return of an extinguished CR in infant…

Compliment Responses of Thai and Punjabi Speakers of English in Thailand

ERIC Educational Resources Information Center

Sachathep, Sukchai

2014-01-01

This variational pragmatics (VP) study investigates the similarities and differences of compliment responses (CR) between Thai and Punjabi speakers of English in Thailand, focusing on the strategies used in CR when the microsociolinguistic variables are integrated into the Discourse Completion Task (DCT). The participants were 20 Thai and 20…

Health benefits of air pollution abatement policy: Role of the shape of the concentration-response function.

PubMed

Pope, C Arden; Cropper, Maureen; Coggins, Jay; Cohen, Aaron

2015-05-01

There is strong evidence that fine particulate matter (aerodynamic diameter<2.5 μm; PM2.5) air pollution contributes to increased risk of disease and death. Estimates of the burden of disease attributable to PM2.5 pollution and benefits of reducing pollution are dependent upon the shape of the concentration response (C-R) functions. Recent evidence suggests that the C-R function between PM2.5 air pollution and mortality risk may be supralinear across wide ranges of exposure. Such results imply that incremental pollution abatement efforts may yield greater benefits in relatively clean areas than in highly polluted areas. The role of the shape of the C-R function in evaluating and understanding the costs and health benefits of air pollution abatement policy is explored. There remain uncertainties regarding the shape of the C-R function, and additional efforts to more fully understand the C-R relationships between PM2.5 and adverse health effects are needed to allow for more informed and effective air pollution abatement policies. Current evidence, however, suggests that there are benefits both from reducing air pollution in the more polluted areas and from continuing to reduce air pollution in cleaner areas. Estimates of the benefits of reducing PM2.5 air pollution are highly dependent upon the shape of the PM2.5-mortality concentration-response (C-R) function. Recent evidence indicates that this C-R function may be supralinear across wide ranges of exposure, suggesting that incremental pollution abatement efforts may yield greater benefits in relatively clean areas than in highly polluted areas. This paper explores the role of the shape of the C-R function in evaluating and understanding the costs and health benefits of PM2.5 air pollution abatement.

Fractionated gemtuzumab ozogamicin and standard dose cytarabine produced prolonged second remissions in patients over the age of 55 years with acute myeloid leukemia in late first relapse.

PubMed

Pilorge, Sylvain; Rigaudeau, Sophie; Rabian, Florence; Sarkozy, Clémentine; Taksin, Anne L; Farhat, Hassan; Merabet, Fathia; Ghez, Stéphanie; Raggueneau, Victoria; Terré, Christine; Garcia, Isabelle; Renneville, Aline; Preudhomme, Claude; Castaigne, Sylvie; Rousselot, Philippe

2014-04-01

Gemtuzumab ozogamicin (fGO), a humanized anti-CD33 monoclonal antibody linked to calicheamicin in combination with intensive chemotherapy gives high response rates in adult acute myeloid leukemia (AML) patients in relapse. However, reduced intensity chemotherapy in combination with fractionated GO has not been tested in aged relapsing patients. Patients from our institution with CD33+ AML aged 55 years or more in first late relapse (≥ 6 months) were proposed participation in a GO compassionate use program. Induction therapy consisted in fractionated GO (fGO; 3 mg/m², days 1, 4, 7) with standard-dose cytarabine (200 mg/m² /day, 7 days). Patients were consolidated with two courses of GO and intermediate dose cytarabine. Twenty-four patients (median age 68 years) received fGO with cytarabine. Median follow-up was 42 months. The response rate was 75%, including complete remission (CR) in 16 patients and CR with incomplete platelet recovery (CRp) in two patients. Two-year overall survival (OS) was 51% (95% CI: 28-69) and 2 years relapse-free survival (RFS) was 51% (95%CI: 25-72). Duration of second CR (CR2) was longer than first CR (CR1) in 9 out of 18 patients. Minimal residual disease (MRD) was negative in evaluable patients in CR2, particularly in NPM1 mutated cases. Toxicity was in line with that of the same fractionated single agent GO schedule. Fractionated GO with low intensity chemotherapy produced high response rates and prolonged CR2 in aged AML patients in first late relapse. Copyright © 2013 Wiley Periodicals, Inc.

Automatic Scoring of Paper-and-Pencil Figural Responses. Research Report.

ERIC Educational Resources Information Center

Martinez, Michael E.; And Others

Large-scale testing is dominated by the multiple-choice question format. Widespread use of the format is due, in part, to the ease with which multiple-choice items can be scored automatically. This paper examines automatic scoring procedures for an alternative item type: figural response. Figural response items call for the completion or…

Introduction to Multilevel Item Response Theory Analysis: Descriptive and Explanatory Models

ERIC Educational Resources Information Center

Sulis, Isabella; Toland, Michael D.

2017-01-01

Item response theory (IRT) models are the main psychometric approach for the development, evaluation, and refinement of multi-item instruments and scaling of latent traits, whereas multilevel models are the primary statistical method when considering the dependence between person responses when primary units (e.g., students) are nested within…

An Extension of IRT-Based Equating to the Dichotomous Testlet Response Theory Model

ERIC Educational Resources Information Center

Tao, Wei; Cao, Yi

2016-01-01

Current procedures for equating number-correct scores using traditional item response theory (IRT) methods assume local independence. However, when tests are constructed using testlets, one concern is the violation of the local item independence assumption. The testlet response theory (TRT) model is one way to accommodate local item dependence.…

Estimating Ordinal Reliability for Likert-Type and Ordinal Item Response Data: A Conceptual, Empirical, and Practical Guide

ERIC Educational Resources Information Center

Gadermann, Anne M.; Guhn, Martin; Zumbo, Bruno D.

2012-01-01

This paper provides a conceptual, empirical, and practical guide for estimating ordinal reliability coefficients for ordinal item response data (also referred to as Likert, Likert-type, ordered categorical, or rating scale item responses). Conventionally, reliability coefficients, such as Cronbach's alpha, are calculated using a Pearson…

IRTPRO 2.1 for Windows (Item Response Theory for Patient-Reported Outcomes)

ERIC Educational Resources Information Center

Paek, Insu; Han, Kyung T.

2013-01-01

This article reviews a new item response theory (IRT) model estimation program, IRTPRO 2.1, for Windows that is capable of unidimensional and multidimensional IRT model estimation for existing and user-specified constrained IRT models for dichotomously and polytomously scored item response data. (Contains 1 figure and 2 notes.)

The Robustness of LOGIST and BILOG IRT Estimation Programs to Violations of Local Independence.

ERIC Educational Resources Information Center

Ackerman, Terry A.

One of the important underlying assumptions of all item response theory (IRT) models is that of local independence. This assumption requires that the response to an item on a test not be influenced by the response to any other items. This assumption is often taken for granted, with little or no scrutiny of the response process required to answer…

Food survey: levels and potential health risks of chromium, lead, zinc and copper content in fruits and vegetables consumed in Algeria.

PubMed

Cherfi, Abdelhamid; Abdoun, Samira; Gaci, Ouardia

2014-08-01

A food survey was carried out with the aim to investigate the levels of lead (Pb), zinc (Zn), copper (Cu) and chromium (Cr) in various fruits and vegetables sold in Algeria. Concentrations (mg/kgdry wt.) in selected foodstuffs were detected within the following ranges: 4-29.49, 11.17-49, 12.33-39.33 and 3-16.33 for Cu, Zn, Pb and Cr respectively. The food ingestion rate of the selected items was investigated by self-administered questionnaires which were filled by a total of 843 people randomly recruited at the exit of markets. The potential health risk for consumers was investigated by estimating the daily intake (EDI) and the target hazard quotient (THQ) for each heavy metal. For all foodstuffs, the EDI and the THQ were below the threshold values for Cu, Zn and Cr while they exceeded the thresholds for Pb (EDI: 15.66μgPb/kg body weight/day; THQ: 4.37), indicating an obvious health risk over a life time of exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Unhealthy behaviour modification, psychological distress, and 1-year survival in cardiac rehabilitation.

PubMed

Gostoli, Sara; Roncuzzi, Renzo; Urbinati, Stefano; Morisky, Donald E; Rafanelli, Chiara

2016-11-01

Cardiac rehabilitation (CR) is considered the recommended secondary prevention treatment for cardiovascular diseases (CVD), in terms of health behaviours and, secondarily, better cardiac outcomes promotion. However, the role of psychiatric and psychosomatic distress on the efficacy of CR is unclear. This research aimed to evaluate the impact of CR on unhealthy behaviour modification and cardiac course, considering the moderating role of depression, anxiety, and psychosomatic syndromes. A longitudinal design between and within groups was employed. The assessment was repeated four times: at admission to CR (T1), at discharge (T2), 6 (T3) and 12 months following CR completion (T4). One hundred and eight patients undergoing CR versus 85 patients with CVD not referred to CR, underwent psychiatric, psychosomatic, and health behaviour assessment. The assessment included the Structured Clinical Interview for DSM-IV (depression and anxiety), the interview based on Diagnostic Criteria for Psychosomatic Research, GOSPEL Study questionnaire (health behaviours), Pittsburgh Sleep Quality Index, and 8-item Morisky Medication Adherence Scale. Cardiac rehabilitation was associated with maintenance of physical activity, improvement of behavioural aspects related to food consumption, stress management, and sleep quality. On the contrary, CR was not associated with weight loss, healthy diet, and medication adherence. Depression and psychosomatic syndromes seem to moderate the modification of specific health-related behaviours (physical activity, behavioural aspects of food consumption, stress management, and pharmacological adherence). In CR settings, an integrated assessment including both psychiatric and psychosomatic syndromes is needed to address psychological factors associated with unhealthy behaviour modification. Statement of contribution What is already known on this subject? Cardiac rehabilitation (CR) is considered a class 1A treatment recommendation and the most cost-effective model of secondary prevention to reduce cardiovascular events. There is evidence about the association between psychological distress and both unhealthy behaviour and cardiac course. Depression and psychosomatic distress, such as type A behaviour and demoralization, are frequently associated with CVD course. However, the role of psychiatric and psychosomatic distress in CR is not well known. What does this study add? CR exerted a protective effect on physical activity and a positive effect on eating behaviour, stress management, and quality of sleep. CR did not show any particular effect on smoking, overweight/obesity, dietary habits, medication adherence, and patients' 1-year survival. Findings from this study suggest the importance to consider specific psychological and psychosomatic aspects in affecting lifestyle. © 2016 The British Psychological Society.

Item response theory scoring and the detection of curvilinear relationships.

PubMed

Carter, Nathan T; Dalal, Dev K; Guan, Li; LoPilato, Alexander C; Withrow, Scott A

2017-03-01

Psychologists are increasingly positing theories of behavior that suggest psychological constructs are curvilinearly related to outcomes. However, results from empirical tests for such curvilinear relations have been mixed. We propose that correctly identifying the response process underlying responses to measures is important for the accuracy of these tests. Indeed, past research has indicated that item responses to many self-report measures follow an ideal point response process-wherein respondents agree only to items that reflect their own standing on the measured variable-as opposed to a dominance process, wherein stronger agreement, regardless of item content, is always indicative of higher standing on the construct. We test whether item response theory (IRT) scoring appropriate for the underlying response process to self-report measures results in more accurate tests for curvilinearity. In 2 simulation studies, we show that, regardless of the underlying response process used to generate the data, using the traditional sum-score generally results in high Type 1 error rates or low power for detecting curvilinearity, depending on the distribution of item locations. With few exceptions, appropriate power and Type 1 error rates are achieved when dominance-based and ideal point-based IRT scoring are correctly used to score dominance and ideal point response data, respectively. We conclude that (a) researchers should be theory-guided when hypothesizing and testing for curvilinear relations; (b) correctly identifying whether responses follow an ideal point versus dominance process, particularly when items are not extreme is critical; and (c) IRT model-based scoring is crucial for accurate tests of curvilinearity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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

Seyler, Kyle L.; Zhong, Ding; Klein, Dahlia R.

Bulk chromium tri-iodide (CrI 3) has long been known as a layered van der Waals ferromagnet. However, its monolayer form was only recently isolated and confirmed to be a truly two-dimensional (2D) ferromagnet, providing a new platform for investigating light–matter interactions and magneto-optical phenomena in the atomically thin limit. Here in this paper, we report spontaneous circularly polarized photoluminescence in monolayer CrI 3 under linearly polarized excitation, with helicity determined by the monolayer magnetization direction. In contrast, the bilayer CrI 3 photoluminescence exhibits vanishing circular polarization, supporting the recently uncovered anomalous antiferromagnetic interlayer coupling in CrI 3 bilayers. Distinct frommore » the Wannier–Mott excitons that dominate the optical response in well-known 2D van der Waals semiconductors, our absorption and layer-dependent photoluminescence measurements reveal the importance of ligand-field and charge-transfer transitions to the optoelectronic response of atomically thin CrI 3. We attribute the photoluminescence to a parity-forbidden d–d transition characteristic of Cr 3+ complexes, which displays broad linewidth due to strong vibronic coupling and thickness-independent peak energy due to its localized molecular orbital nature.« less

Reduction of hexavalent chromium using Aerva lanata L.: elucidation of reduction mechanism and identification of active principles.

PubMed

Poonkuzhali, K; Rajeswari, V; Saravanakumar, T; Viswanathamurthi, P; Park, Seung-Moon; Govarthanan, M; Sathishkumar, P; Palvannan, T

2014-05-15

The effluent discharge treatment for controlling the environment from non biodegradable metal contaminants using plant extract is an efficient technique. The reduction of hexavalent chromium by abundantly available weed, Aerva lanata L. was investigated using batch equilibrium technique. The variables studied were Cr(VI) concentration, Aerva lanata L. dose, contact time, pH, temperature and agitation speed. Cyclic voltammetry and ICP-MS analysis confirmed the reduction of Cr(VI) to Cr(III). Electrochemical analysis proved that, the chromium has not been degraded and the valency of the chromium has only been changed. ICP-MS analysis shows that 100ng/L of hexavalent chromium was reduced to 97.01ng/L trivalent chromium. These results suggest that components present in the Aerva lanata L. are responsible for the reduction of Cr(VI) to Cr(III). The prime components ferulic acid, kaempherol and β-carboline present in the Aerva lanata L. may be responsible for the reduction of Cr(VI) as evident from LC-MS analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of chromium on the immune system.

PubMed

Shrivastava, Richa; Upreti, R K; Seth, P K; Chaturvedi, U C

2002-09-06

Chromium is a naturally occurring heavy metal found commonly in the environment in trivalent, Cr(III), and hexavalent, Cr(VI), forms. Cr(VI) compounds have been declared as a potent occupational carcinogen among workers in chrome plating, stainless steel, and pigment industries. The reduction of Cr(VI) to Cr(III) results in the formation of reactive intermediates that together with oxidative stress oxidative tissue damage and a cascade of cellular events including modulation of apoptosis regulatory gene p53, contribute to the cytotoxicity, genotoxicity and carcinogenicity of Cr(VI)-containing compounds. On the other hand, chromium is an essential nutrient required to promote the action of insulin in body tissues so that the body can use sugars, proteins and fats. Chromium is of significant importance in altering the immune response by immunostimulatory or immunosuppressive processes as shown by its effects on T and B lymphocytes, macrophages, cytokine production and the immune response that may induce hypersensitivity reactions. This review gives an overview of the effects of chromium on the immune system of the body. Copyright 2002 Federation of European Microbiological Societies

Assessing Construct Validity Using Multidimensional Item Response Theory.

ERIC Educational Resources Information Center

Ackerman, Terry A.

The concept of a user-specified validity sector is discussed. The idea of the validity sector combines the work of M. D. Reckase (1986) and R. Shealy and W. Stout (1991). Reckase developed a methodology to represent an item in a multidimensional latent space as a vector. Item vectors are computed using multidimensional item response theory item…

Least Squares Distance Method of Cognitive Validation and Analysis for Binary Items Using Their Item Response Theory Parameters

ERIC Educational Resources Information Center

Dimitrov, Dimiter M.

2007-01-01

The validation of cognitive attributes required for correct answers on binary test items or tasks has been addressed in previous research through the integration of cognitive psychology and psychometric models using parametric or nonparametric item response theory, latent class modeling, and Bayesian modeling. All previous models, each with their…

Mixture Item Response Theory-MIMIC Model: Simultaneous Estimation of Differential Item Functioning for Manifest Groups and Latent Classes

ERIC Educational Resources Information Center

Bilir, Mustafa Kuzey

2009-01-01

This study uses a new psychometric model (mixture item response theory-MIMIC model) that simultaneously estimates differential item functioning (DIF) across manifest groups and latent classes. Current DIF detection methods investigate DIF from only one side, either across manifest groups (e.g., gender, ethnicity, etc.), or across latent classes…

Item Response Theory and Health Outcomes Measurement in the 21st Century

PubMed Central

Hays, Ron D.; Morales, Leo S.; Reise, Steve P.

2006-01-01

Item response theory (IRT) has a number of potential advantages over classical test theory in assessing self-reported health outcomes. IRT models yield invariant item and latent trait estimates (within a linear transformation), standard errors conditional on trait level, and trait estimates anchored to item content. IRT also facilitates evaluation of differential item functioning, inclusion of items with different response formats in the same scale, and assessment of person fit and is ideally suited for implementing computer adaptive testing. Finally, IRT methods can be helpful in developing better health outcome measures and in assessing change over time. These issues are reviewed, along with a discussion of some of the methodological and practical challenges in applying IRT methods. PMID:10982088

Efficacy of nonvenous medications for acute convulsive seizures

PubMed Central

Kothari, Harsh; Zhang, Zongjun; Han, Baoguang; Horn, Paul S.; Glauser, Tracy A.

2015-01-01

Objective: This is a network meta-analysis of nonvenous drugs used in randomized controlled trials (RCTs) for treatment of acute convulsive seizures and convulsive status epilepticus. Methods: Literature was searched according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines for RCTs examining treatment of acute convulsive seizures or status epilepticus with at least one of the study arms being a nonvenous medication. After demographic and outcome data extraction, a Bayesian network meta-analysis was performed and efficacy results were summarized using treatment effects and their credible intervals (CrI). We also calculated the probability of each route–drug combination being the most clinically effective for a given outcome, and provided their Bayesian hierarchical ranking. Results: This meta-analysis of 16 studies found that intramuscular midazolam (IM-MDZ) is superior to other nonvenous medications regarding time to seizure termination after administration (2.145 minutes, 95% CrI 1.308–3.489), time to seizure cessation after arrival in the hospital (3.841 minutes, 95% CrI 2.697–5.416), and time to initiate treatment (0.779 minutes, 95% CrI 0.495–1.221). Additionally, intranasal midazolam (IN-MDZ) was adjudged most efficacious for seizure cessation within 10 minutes of administration (90.4% of participants, 95% CrI 79.4%–96.9%), and persistent seizure cessation for ≥1 hour (78.5% of participants, 95% CrI 59.5%–92.1%). Paucity of RCTs produced evidence gaps resulting in small networks, routes/drugs included in some networks but not others, and some trials not being connected to any network. Conclusions: Despite the evidence gaps, IM-MDZ and IN-MDZ exhibit the best efficacy data for the nonvenous treatment of acute convulsive seizures or status epilepticus. PMID:26511448

Translation, Cross-cultural Adaptation and Psychometric Validation of the Korean-Language Cardiac Rehabilitation Barriers Scale (CRBS-K)

PubMed Central

2017-01-01

Objective To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. Methods The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. Results The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (p<0.01). Conclusion The Korean version of CRBS has demonstrated face, content and criterion validity, suggesting it may be useful for assessing barriers to CR utilization in Korea. PMID:29201826

From mean-field localized magnetism to itinerant spin fluctuations in the "nonmetallic metal" FeCrAs

NASA Astrophysics Data System (ADS)

Plumb, K. W.; Stock, C.; Rodriguez-Rivera, J. A.; Castellan, J.-P.; Taylor, J. W.; Lau, B.; Wu, W.; Julian, S. R.; Kim, Young-June

2018-05-01

FeCrAs displays an unusual electrical response that is neither metallic in character nor divergent at low temperatures, as expected for an insulating response, and therefore it has been termed a "nonmetal metal." The anomalous resistivity occurs for temperatures below ˜900 K. We have carried out neutron scattering experiments on powder and single crystal samples to study the magnetic dynamics and critical fluctuations in FeCrAs. Magnetic neutron diffraction measurements find Cr3 + magnetic order setting in at TN=115 K ˜10 meV with a mean-field critical exponent. Using neutron spectroscopy we observe gapless, high velocity, magnetic fluctuations emanating from magnetic positions with propagation wave vector q⃗0=(1/3 ,1/3 ) , which persists up to at least 80 meV ˜927 K, an energy scale much larger than TN. Despite the mean-field magnetic order at low temperatures, the magnetism in FeCrAs therefore displays a response which resembles that of itinerant magnets at high energy transfers. We suggest that the presence of stiff high-energy spin fluctuations extending up to a temperature scale of ˜900 K is the origin of the unusual temperature dependence of the resistivity.

Effects of Sex, Strain, and Energy Intake on Hallmarks of Aging in Mice.

PubMed

Mitchell, Sarah J; Madrigal-Matute, Julio; Scheibye-Knudsen, Morten; Fang, Evandro; Aon, Miguel; González-Reyes, José A; Cortassa, Sonia; Kaushik, Susmita; Gonzalez-Freire, Marta; Patel, Bindi; Wahl, Devin; Ali, Ahmed; Calvo-Rubio, Miguel; Burón, María I; Guiterrez, Vincent; Ward, Theresa M; Palacios, Hector H; Cai, Huan; Frederick, David W; Hine, Christopher; Broeskamp, Filomena; Habering, Lukas; Dawson, John; Beasley, T Mark; Wan, Junxiang; Ikeno, Yuji; Hubbard, Gene; Becker, Kevin G; Zhang, Yongqing; Bohr, Vilhelm A; Longo, Dan L; Navas, Placido; Ferrucci, Luigi; Sinclair, David A; Cohen, Pinchas; Egan, Josephine M; Mitchell, James R; Baur, Joseph A; Allison, David B; Anson, R Michael; Villalba, José M; Madeo, Frank; Cuervo, Ana Maria; Pearson, Kevin J; Ingram, Donald K; Bernier, Michel; de Cabo, Rafael

2016-06-14

Calorie restriction (CR) is the most robust non-genetic intervention to delay aging. However, there are a number of emerging experimental variables that alter CR responses. We investigated the role of sex, strain, and level of CR on health and survival in mice. CR did not always correlate with lifespan extension, although it consistently improved health across strains and sexes. Transcriptional and metabolomics changes driven by CR in liver indicated anaplerotic filling of the Krebs cycle together with fatty acid fueling of mitochondria. CR prevented age-associated decline in the liver proteostasis network while increasing mitochondrial number, preserving mitochondrial ultrastructure and function with age. Abrogation of mitochondrial function negated life-prolonging effects of CR in yeast and worms. Our data illustrate the complexity of CR in the context of aging, with a clear separation of outcomes related to health and survival, highlighting complexities of translation of CR into human interventions. Published by Elsevier Inc.

Electronic and mechanical properties of half-metallic half-Heusler compounds CoCrZ (Z = S, Se, and Te)

NASA Astrophysics Data System (ADS)

Huang, Hai-Ming; Zhang, Chuan-Kun; He, Ze-Dong; Zhang, Jun; Yang, Jun-Tao; Luo, Shi-Jun

2018-01-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 11647133 and 11674113), the Natural Science Foundation of Hubei Province, China (Grant Nos. 2017CFB740 and 2014CFB631), the Scientific Research Items Foundation of Hubei Educational Committee, China (Grant Nos. Q20141802, Q20161803, B2016091, and D20171803), and Hubei Provincial Collaborative Innovation Center for Optoelectronics, China.

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

PubMed Central

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

2014-01-01

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

Mood and cortisol responses following tryptophan-rich hydrolyzed protein and acute stress in healthy subjects with high and low cognitive reactivity to depression.

PubMed

Firk, Christine; Markus, C Rob

2009-06-01

It is suggested that stress particularly in subjects with high cognitive reactivity (CR), a psychological vulnerability marker of depression, may increase or even induce serotonergic vulnerability, which in turn may lead to reduced serotonin (5-HT) function, decreased stress coping and an increased risk to develop depressive symptoms. The aim of the present study was to investigate the beneficial effects of 5-HT augmentation through a tryptophan-rich hydrolyzed protein (HP) on mood and stress coping in subjects with high and low CR. We hypothesized that subjects with high CR are more responsive to the beneficial effects of HP than subjects with low CR particularly after acute stress exposure. In a double-blind, crossover study, participants' mood and cortisol was assessed before and after acute stress exposure either following intake of HP or a standard casein protein (CP) as control condition. HP significantly increased positive mood in all subjects and dampened the cortisol response to acute stress. No differences were found between high and low CR subjects. To conclude, because dietary treatment with HP has beneficial effects on mood and physiological stress coping in both high and low CR subjects, HP may be a good dietary method for augmenting brain TRP and 5-HT and thus 5-HT linked stress resilience.

Configuration of automatic exposure control on mammography units for computed radiography to match patient dose of screen film systems

NASA Astrophysics Data System (ADS)

Yang, Chang-Ying Joseph; Huang, Weidong

2009-02-01

Computed radiography (CR) is considered a drop-in addition or replacement for traditional screen-film (SF) systems in digital mammography. Unlike other technologies, CR has the advantage of being compatible with existing mammography units. One of the challenges, however, is to properly configure the automatic exposure control (AEC) on existing mammography units for CR use. Unlike analogue systems, the capture and display of digital CR images is decoupled. The function of AEC is changed from ensuring proper and consistent optical density of the captured image on film to balancing image quality with patient dose needed for CR. One of the preferences when acquiring CR images under AEC is to use the same patient dose as SF systems. The challenge is whether the existing AEC design and calibration process-most of them proprietary from the X-ray systems manufacturers and tailored specifically for SF response properties-can be adapted for CR cassettes, in order to compensate for their response and attenuation differences. This paper describes the methods for configuring the AEC of three different mammography units models to match the patient dose used for CR with those that are used for a KODAK MIN-R 2000 SF System. Based on phantom test results, these methods provide the dose level under AEC for the CR systems to match with the dose of SF systems. These methods can be used in clinical environments that require the acquisition of CR images under AEC at the same dose levels as those used for SF systems.

Quantifying the Benefit of a Pathologic Complete Response After Neoadjuvant Chemoradiotherapy in the Treatment of Esophageal Cancer

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

Scheer, Richard V.; Fakiris, Achilles J.; Johnstone, Peter A.S., E-mail: pajohnst@iupui.edu

Purpose: To better define the benefit of a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy in the treatment of esophageal and gastroesophageal cancer, we undertook a comprehensive review of the literature to derive a pooled analysis of crude survival data and quantify the survival benefit of pCR vs. residual disease at esophagectomy. Methods and Materials: In all, 22 articles were reviewed. Crude overall survival data, stratified by patients with pCR vs. those with residual disease at esophagectomy, were collected and analyzed using a chi-square analysis. The relative and absolute survival benefit of achieving a pCR were calculated and analyzed. Finally,more » stratified median survival times were also analyzed. Results: Overall survival for patients with pCR was 93.1%, 75.0%, and 50.0% at 2, 3, and 5 years, respectively, whereas it was 36.8%, 29.0%, and 22.6% for patients with residual tumor (p < 0.025). The mean relative survival benefit of pCR at 2, 3, and 5 years was 2.05, 2.35, and 2.84, respectively. The mean absolute survival benefit of pCR was 35.66%, 33.79%, and 33.20%, respectively. Median survival times for patients with pCR were significantly longer than for those with residual tumor (p = 0.011). Conclusion: In esophageal and gastroesophageal cancers, pCR seems to significantly increase overall survival in patients undergoing neoadjuvant chemoradiotherapy. Specifically, the data suggest that patients with pCR are two to three times more likely to survive than are those with residual tumor at esophagectomy. Moreover, these data suggest that 33-36% more patients survive when pCR is achieved than when it is not.« less

Hexavalent Chromium Cr(VI) Up-Regulates COX-2 Expression through an NFκB/c-Jun/AP-1–Dependent Pathway

PubMed Central

Zuo, Zhenghong; Cai, Tongjian; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui

2012-01-01

Background: Hexavalent chromium [Cr(VI)] is recognized as a human carcinogen via inhalation. However, the molecular mechanisms by which Cr(VI) causes cancers are not well understood. Objectives: We evaluated cyclooxygenase-2 (COX-2) expression and the signaling pathway leading to this induction due to Cr(VI) exposure in cultured cells. Methods: We used the luciferase reporter assay and Western blotting to determine COX-2 induction by Cr(VI). We used dominant negative mutant, genetic knockout, gene knockdown, and chromatin immunoprecipitation approaches to elucidate the signaling pathway leading to COX-2 induction. Results: We found that Cr(VI) exposure induced COX-2 expression in both normal human bronchial epithelial cells and mouse embryonic fibroblasts in a concentration- and time-dependent manner. Deletion of IKKβ [inhibitor of transcription factor NFκB (IκB) kinase β; an upstream kinase responsible for nuclear factor κB (NFκB) activation] or overexpression of TAM67 (a dominant-negative mutant of c-Jun) dramatically inhibited the COX-2 induction due to Cr(VI), suggesting that both NFκB and c-Jun/AP-1 pathways were required for Cr(VI)-induced COX-2 expression. Our results show that p65 and c-Jun are two major components involved in NFκB and AP-1 activation, respectively. Moreover, our studies suggest crosstalk between NFκB and c-Jun/AP-1 pathways in cellular response to Cr(VI) exposure for COX-2 induction. Conclusion: We demonstrate for the first time that Cr(VI) is able to induce COX-2 expression via an NFκB/c-Jun/AP-1–dependent pathway. Our results provide novel insight into the molecular mechanisms linking Cr(VI) exposure to lung inflammation and carcinogenesis. PMID:22472290

Quantifying the benefit of a pathologic complete response after neoadjuvant chemoradiotherapy in the treatment of esophageal cancer.

PubMed

Scheer, Richard V; Fakiris, Achilles J; Johnstone, Peter A S

2011-07-15

To better define the benefit of a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy in the treatment of esophageal and gastroesophageal cancer, we undertook a comprehensive review of the literature to derive a pooled analysis of crude survival data and quantify the survival benefit of pCR vs. residual disease at esophagectomy. In all, 22 articles were reviewed. Crude overall survival data, stratified by patients with pCR vs. those with residual disease at esophagectomy, were collected and analyzed using a chi-square analysis. The relative and absolute survival benefit of achieving a pCR were calculated and analyzed. Finally, stratified median survival times were also analyzed. Overall survival for patients with pCR was 93.1%, 75.0%, and 50.0% at 2, 3, and 5 years, respectively, whereas it was 36.8%, 29.0%, and 22.6% for patients with residual tumor (p < 0.025). The mean relative survival benefit of pCR at 2, 3, and 5 years was 2.05, 2.35, and 2.84, respectively. The mean absolute survival benefit of pCR was 35.66%, 33.79%, and 33.20%, respectively. Median survival times for patients with pCR were significantly longer than for those with residual tumor (p = 0.011). In esophageal and gastroesophageal cancers, pCR seems to significantly increase overall survival in patients undergoing neoadjuvant chemoradiotherapy. Specifically, the data suggest that patients with pCR are two to three times more likely to survive than are those with residual tumor at esophagectomy. Moreover, these data suggest that 33-36% more patients survive when pCR is achieved than when it is not. Copyright © 2011 Elsevier Inc. All rights reserved.

[Treatment of chronic refractory idiopathic thrombocytopenia purpura. 10 years experience at the Salvador Zubiran National Institute of Nutrition].

PubMed

Pita-Ramírez, L; Hurtado-Monroy, R; Labardini-Méndez, J

1992-01-01

A total of 126 patients with chronic idiopathic thrombocytopenic purpura were diagnosed from January 1980 to January 1990 in our institute. In this group of patients, 21 were refractory to prednisone therapy, splenectomy or both, or had had a relapse after a good response with these treatments. They were given other therapies. There was enough information for evaluation in 16 of the 21 patients. The treatment responses were classified according to the post-therapy platelet counts: complete response (CR) = > 150 x 10(9)/L for more than three months; partial response (PR) = 50-150 x 10(9)/L for more than three months; any response (AR) = CR + PR; no response (NR) = < 50 x 10(9)/L. There were 15 women and one male. The median age was 41 years (range 11 to 65). 6-mercaptopurine was given in all patients with CR = 31.2%, PR = 18.8%, AR = 50% and NR = 50%. Seven patients received cyclophosphamide with CR = 28.6%, PR = 14.3%, AR = 42.9% and NR = 57%. Vincristine was given in four patients with only one PR. Interferon alpha 2B was given in four patients with two transitory PR. One patient received colchicine and vitamin C without response. It is concluded that 6-mercaptopurine and cyclophosphamide are useful drugs in refractory thrombocytopenic purpura.

The effect of response modality on immediate serial recall in dementia of the Alzheimer type.

PubMed

Macé, Anne-Laure; Ergis, Anne-Marie; Caza, Nicole

2012-09-01

Contrary to traditional models of verbal short-term memory (STM), psycholinguistic accounts assume that temporary retention of verbal materials is an intrinsic property of word processing. Therefore, memory performance will depend on the nature of the STM tasks, which vary according to the linguistic representations they engage. The aim of this study was to explore the effect of response modality on verbal STM performance in individuals with dementia of the Alzheimer Type (DAT), and its relationship with the patients' word-processing deficits. Twenty individuals with mild DAT and 20 controls were tested on an immediate serial recall (ISR) task using the same items across two response modalities (oral and picture pointing) and completed a detailed language assessment. When scoring of ISR performance was based on item memory regardless of item order, a response modality effect was found for all participants, indicating that they recalled more items with picture pointing than with oral response. However, this effect was less marked in patients than in controls, resulting in an interaction. Interestingly, when recall of both item and order was considered, results indicated similar performance between response modalities in controls, whereas performance was worse for pointing than for oral response in patients. Picture-naming performance was also reduced in patients relative to controls. However, in the word-to-picture matching task, a similar pattern of responses was found between groups for incorrectly named pictures of the same items. The finding of a response modality effect in item memory for all participants is compatible with the assumption that semantic influences are greater in picture pointing than in oral response, as predicted by psycholinguistic models. Furthermore, patients' performance was modulated by their word-processing deficits, showing a reduced advantage relative to controls. Overall, the response modality effect observed in this study for item memory suggests that verbal STM performance is intrinsically linked with word processing capacities in both healthy controls and individuals with mild DAT, supporting psycholinguistic models of STM.

Comparison of integrated testlet and constructed-response question formats

NASA Astrophysics Data System (ADS)

Slepkov, Aaron D.; Shiell, Ralph C.

2014-12-01

Constructed-response (CR) questions are a mainstay of introductory physics textbooks and exams. However, because of the time, cost, and scoring reliability constraints associated with this format, CR questions are being increasingly replaced by multiple-choice (MC) questions in formal exams. The integrated testlet (IT) is a recently developed question structure designed to provide a proxy of the pedagogical advantages of CR questions while procedurally functioning as set of MC questions. ITs utilize an answer-until-correct response format that provides immediate confirmatory or corrective feedback, and they thus allow not only for the granting of partial credit in cases of initially incorrect reasoning, but, furthermore, the ability to build cumulative question structures. Here, we report on a study that directly compares the functionality of ITs and CR questions in introductory physics exams. To do this, CR questions were converted to concept-equivalent ITs, and both sets of questions were deployed in midterm and final exams. We find that both question types provide adequate discrimination between stronger and weaker students, with CR questions discriminating slightly better than the ITs. There is some indication that any difference in discriminatory power may result from the baseline score for guessing that is inherent in MC testing. Meanwhile, an analysis of interrater scoring of the CR questions raises serious concerns about the reliability of the granting of partial credit when this traditional assessment technique is used in a realistic (but nonoptimized) setting. Furthermore, we show evidence that partial credit is granted in a valid manner in the ITs. Thus, together with consideration of the vastly reduced costs of administering IT-based examinations compared to CR-based examinations, our findings indicate that ITs are viable replacements for CR questions in formal examinations where it is desirable both to assess concept integration and to reward partial knowledge, while efficiently scoring examinations.

A Study of General Education Astronomy Students' Understandings of Cosmology. Part III. Evaluating Four Conceptual Cosmology Surveys: An Item Response Theory Approach

ERIC Educational Resources Information Center

Wallace, Colin S.; Prather, Edward E.; Duncan, Douglas K.

2012-01-01

This is the third of five papers detailing our national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. In this paper, we use item response theory to analyze students' responses to three out of the four conceptual cosmology surveys we developed. The specific item response theory model we use is…

Response evaluation after primary systemic therapy of Her2 positive breast cancer – an observational cross-sectional study.

PubMed

Tőkés, Tímea; Szentmártoni, Gyöngyvér; Torgyík, László; Kajáry, Kornélia; Lengyel, Zsolt; Györke, Tamás; Molnár, Béla Á; Tőkés, Anna-Mária; Kulka, Janina; Dank, Magdolna

2015-04-01

To evaluate (I) trastuzumab-containing primary systemic therapy (PST) in human epidermal growth factor receptor 2 (Her2) overexpressing breast carcinomas.; (II) compare the patients who achieved and those who did not achieve pathological complete remission (pCR), and (III) analyze the accuracy of different clinical-imaging modalities in tumor response monitoring. 188 patients who received PST between 2008 and 2014 were reviewed and 43 Her2 overexpressing breast cancer patients (28 Luminal B/Her2-positive and 15 Her2-positive) were enrolled. 26 patients received mostly taxane-based PST without trastuzumab (Group 1) and 17 patients received trastuzumab-containing PST (Group 2). We compared the concordance between pCR and complete remission (CR) defined by breast-ultrasound, CR defined by standard 18F-fluoro-deoxy-glucose positron emission tomography and computerized tomography (FDG-PET/CT) criteria (Method 1) and CR defined by a novel, breast cancer specific FDG-PET/CT criteria (Method 2). Sensitivity (sens), specificity (spec), and positive (PPV) and negative predictive values (NPV) were calculated. Ten patients (38.5%) in Group 1 and eight (47%) in Group 2 achieved pCR. pCR was significantly more frequent in Her2-positive than in Luminal B/Her2-positive tumors in both Group 1: (P=0.043) and Group 2: (P=0.029). PET/CT evaluated by the breast cancer specific criteria (Method 2) differentiated pCR from non-pCR more accurately in both groups (Group 1: sens=77.8%, spec=%, PPV=100%, NPV=71.4%; Group 2: sens=87.5%, spec=62.5%, PPV=70%, NPV=83.3%) than standard PET/CT criteria (Method 1) (Group 1: sens=22.2% spec=100% PPV=100% NPV=41.7%; in Group 2: sens=37.5%, spec=87.5%, PPV=75% NPV=58.3%) or breast ultrasound (Group 1, sens=83.3% spec=25% PPV=62.5% NPV=50%; Group 2, sens=100% spec=12.5% PPV=41.6% NPV=100%). The benefit of targeted treatment with trastuzumab-containing PST in Her2 overexpressing breast cancer was defined in terms of pCR rate. Luminal B/Her2-positive subtype needs further subdivision to identify patients who would benefit from PST. Combined evaluation of tumor response by our novel, breast cancer specific FDG-PET/CT criteria accurately differentiated pCR from non-pCR patients.

A Comparison of Measurement Equivalence Methods Based on Confirmatory Factor Analysis and Item Response Theory.

ERIC Educational Resources Information Center

Flowers, Claudia P.; Raju, Nambury S.; Oshima, T. C.

Current interest in the assessment of measurement equivalence emphasizes two methods of analysis, linear, and nonlinear procedures. This study simulated data using the graded response model to examine the performance of linear (confirmatory factor analysis or CFA) and nonlinear (item-response-theory-based differential item function or IRT-Based…

A Polytomous Item Response Theory Analysis of Social Physique Anxiety Scale

ERIC Educational Resources Information Center

Fletcher, Richard B.; Crocker, Peter

2014-01-01

The present study investigated the social physique anxiety scale's factor structure and item properties using confirmatory factor analysis and item response theory. An additional aim was to identify differences in response patterns between groups (gender). A large sample of high school students aged 11-15 years (N = 1,529) consisting of n =…

Item Response Theory at Subject- and Group-Level. Research Report 90-1.

ERIC Educational Resources Information Center

Tobi, Hilde

This paper reviews the literature about item response models for the subject level and aggregated level (group level). Group-level item response models (IRMs) are used in the United States in large-scale assessment programs such as the National Assessment of Educational Progress and the California Assessment Program. In the Netherlands, these…

The Role of Psychometric Modeling in Test Validation: An Application of Multidimensional Item Response Theory

ERIC Educational Resources Information Center

Schilling, Stephen G.

2007-01-01

In this paper the author examines the role of item response theory (IRT), particularly multidimensional item response theory (MIRT) in test validation from a validity argument perspective. The author provides justification for several structural assumptions and interpretations, taking care to describe the role he believes they should play in any…

Stochastic Approximation Methods for Latent Regression Item Response Models. Research Report. ETS RR-09-09

ERIC Educational Resources Information Center

von Davier, Matthias; Sinharay, Sandip

2009-01-01

This paper presents an application of a stochastic approximation EM-algorithm using a Metropolis-Hastings sampler to estimate the parameters of an item response latent regression model. Latent regression models are extensions of item response theory (IRT) to a 2-level latent variable model in which covariates serve as predictors of the…

Exploring the Robustness of a Unidimensional Item Response Theory Model with Empirically Multidimensional Data

ERIC Educational Resources Information Center

Anderson, Daniel; Kahn, Joshua D.; Tindal, Gerald

2017-01-01

Unidimensionality and local independence are two common assumptions of item response theory. The former implies that all items measure a common latent trait, while the latter implies that responses are independent, conditional on respondents' location on the latent trait. Yet, few tests are truly unidimensional. Unmodeled dimensions may result in…

The Random Response Technique as an Indicator of Questionnaire Item Social Desirability/Personal Sensitivity.

ERIC Educational Resources Information Center

Crino, Michael D.; And Others

1985-01-01

The random response technique was compared to a direct questionnaire, administered to college students, to investigate whether or not the responses predicted the social desirability of the item. Results suggest support for the hypothesis. A 33-item version of the Marlowe-Crowne Social Desirability Scale which was used is included. (GDC)

Patterns of intraspecific variability in the response to caloric restriction

PubMed Central

Gribble, Kristin E.; Kaido, Oksana; Jarvis, George; Mark Welch, David B.

2014-01-01

Caloric restriction (CR) is cited as the most robust means of increasing lifespan across a range of taxa, yet there is a high degree of variability in the response to CR, both within and between species. To examine the intraspecific evolutionary conservation of lifespan extension by CR, we tested the effects of chronic caloric restriction (CCR) at multiple food levels and of intermittent fasting (IF) in twelve isolates from the Brachionus plicatilis species complex of monogonont rotifers. While CCR generally increased or did not change lifespan and total fecundity, IF caused increased, unchanged, or decreased lifespan, depending upon the isolate, and decreased total fecundity in all but one isolate. Lifespan under ad libitum (AL) feeding varied among isolates and predicted the lifespan response to CR: longer-lived isolates under AL were less likely to have a significant increase in lifespan under CCR and were more likely to have a significantly shortened lifespan under IF. Lifespan under AL conditions and the response to CR were not correlated with hydroperiodicity of native habitat or with time in culture. Lack of trade-off between lifespan and fecundity under CCR, and differences in lifespan and fecundity under CCR and IF, even when average food intake was similar, suggest that longevity changes are not always directly determined by energy intake and that CCR and IF regimens extend lifespan through diverse genetic mechanisms. PMID:24384399

Patterns of intraspecific variability in the response to caloric restriction.

PubMed

Gribble, Kristin E; Kaido, Oksana; Jarvis, George; Mark Welch, David B

2014-03-01

Caloric restriction (CR) is cited as the most robust means of increasing lifespan across a range of taxa, yet there is a high degree of variability in the response to CR, both within and between species. To examine the intraspecific evolutionary conservation of lifespan extension by CR, we tested the effects of chronic caloric restriction (CCR) at multiple food levels and of intermittent fasting (IF) in twelve isolates from the Brachionus plicatilis species complex of monogonont rotifers. While CCR generally increased or did not change lifespan and total fecundity, IF caused increased, unchanged, or decreased lifespan, depending upon the isolate, and decreased total fecundity in all but one isolate. Lifespan under ad libitum (AL) feeding varied among isolates and predicted the lifespan response to CR: longer-lived isolates under AL were less likely to have a significant increase in lifespan under CCR and were more likely to have a significantly shortened lifespan under IF. Lifespan under AL conditions and the response to CR were not correlated with hydroperiodicity of native habitat or with time in culture. Lack of trade-off between lifespan and fecundity under CCR, and differences in lifespan and fecundity under CCR and IF, even when average food intake was similar, suggest that longevity changes are not always directly determined by energy intake and that CCR and IF regimens extend lifespan through diverse genetic mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of Internal Construct Validity and Unidimensionality of the Brachial Assessment Tool, A Patient-Reported Outcome Measure for Brachial Plexus Injury.

PubMed

Hill, Bridget; Pallant, Julie; Williams, Gavin; Olver, John; Ferris, Scott; Bialocerkowski, Andrea

2016-12-01

To evaluate the internal construct validity and dimensionality of a new patient-reported outcome measure for people with traumatic brachial plexus injury (BPI) based on the International Classification of Functioning, Disability and Health definition of activity. Cross-sectional study. Outpatient clinics. Adults (age range, 18-82y) with a traumatic BPI (N=106). There were 106 people with BPI who completed a 51-item 5-response questionnaire. Responses were analyzed in 4 phases (missing responses, item correlations, exploratory factor analysis, and Rasch analysis) to evaluate the properties of fit to the Rasch model, threshold response, local dependency, dimensionality, differential item functioning, and targeting. Not applicable, as this study addresses the development of an outcome measure. Six items were deleted for missing responses, and 10 were deleted for high interitem correlations >.81. The remaining 35 items, while demonstrating fit to the Rasch model, showed evidence of local dependency and multidimensionality. Items were divided into 3 subscales: dressing and grooming (8 items), arm and hand (17 items), and no hand (6 items). All 3 subscales demonstrated fit to the model with no local dependency, minimal disordered thresholds, no unidimensionality or differential item functioning for age, time postinjury, or self-selected dominance. Subscales were combined into 3 subtests and demonstrated fit to the model, no misfit, and unidimensionality, allowing calculation of a summary score. This preliminary analysis supports the internal construct validity of the Brachial Assessment Tool, a unidimensional targeted 4-response patient-reported outcome measure designed to solely assess activity after traumatic BPI regardless of level of injury, age at recruitment, premorbid limb dominance, and time postinjury. Further examination is required to determine test-retest reliability and responsiveness. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Act of Answering Questions Elicited Differentiated Responses in a Concealed Information Test.

PubMed

Otsuka, Takuro; Mizutani, Mitsuyoshi; Yagi, Akihiro; Katayama, Jun'ichi

2018-04-17

The concealed information test (CIT), a psychophysiological detection of deception test, compares physiological responses between crime-related and crime-unrelated items. In previous studies, whether the act of answering questions affected physiological responses was unclear. This study examined effects of both question-related and answer-related processes on physiological responses. Twenty participants received a modified CIT, in which the interval between presentation of questions and answering them was 27 s. Differentiated respiratory movements and cardiovascular responses between items were observed for both questions (items) and answers, while differentiated skin conductance response was observed only for questions. These results suggest that physiological responses to questions reflected orientation to a crime-related item, while physiological responses during answering reflected inhibition of psychological arousal caused by orienting. Regarding the CIT's accuracy, participants' perception of the questions themselves more strongly influenced physiological responses than answering them. © 2018 American Academy of Forensic Sciences.

Disruption of rcsB by a duplicated sequence in a curli-producing Escherichia coli O157:H7 results in differential gene expression in relation to biofilm formation, stress responses, and metabolism

USDA-ARS?s Scientific Manuscript database

Background: Escherichia coli O157:H7 (O157) strain 86-24, linked to a 1986 disease outbreak, displays biofilm- and curli-negative phenotypes that are correlated with the lack of Congo red (CR) binding and formation of white colonies (CR negative) on a CR negative containing medium. However, on a CR ...

Response of timepix detector with GaAs:Cr and Si sensor to heavy ions

NASA Astrophysics Data System (ADS)

Abu Al Azm, S. M.; Chelkov, G.; Kozhevnikov, D.; Guskov, A.; Lapkin, A.; Leyva Fabelo, A.; Smolyanskiy, P.; Zhemchugov, A.

2016-05-01

The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been studied at the cyclotron U-400M of the JINR Flerov Laboratory of Nuclear Reaction. Sensors produced from gallium arsenide compensated by chromium and from silicon are used for these measurements. While in Timepix detector with Si sensor the well-known so-called "volcano effect" observed, in Timepix detector with GaAs:Cr sensor such effect was completely absent. In the work the behavior of the Timepix detector with GaAs:Cr sensor under irradiation with heavy ions is described in comparison with the detector based on Si sensor. Also the possible reason for absence of "volcano" effect in GaAs:Cr detector is proposed.

Development and validation of an item response theory-based Social Responsiveness Scale short form.

PubMed

Sturm, Alexandra; Kuhfeld, Megan; Kasari, Connie; McCracken, James T

2017-09-01

Research and practice in autism spectrum disorder (ASD) rely on quantitative measures, such as the Social Responsiveness Scale (SRS), for characterization and diagnosis. Like many ASD diagnostic measures, SRS scores are influenced by factors unrelated to ASD core features. This study further interrogates the psychometric properties of the SRS using item response theory (IRT), and demonstrates a strategy to create a psychometrically sound short form by applying IRT results. Social Responsiveness Scale analyses were conducted on a large sample (N = 21,426) of youth from four ASD databases. Items were subjected to item factor analyses and evaluation of item bias by gender, age, expressive language level, behavior problems, and nonverbal IQ. Item selection based on item psychometric properties, DIF analyses, and substantive validity produced a reduced item SRS short form that was unidimensional in structure, highly reliable (α = .96), and free of gender, age, expressive language, behavior problems, and nonverbal IQ influence. The short form also showed strong relationships with established measures of autism symptom severity (ADOS, ADI-R, Vineland). Degree of association between all measures varied as a function of expressive language. Results identified specific SRS items that are more vulnerable to non-ASD-related traits. The resultant 16-item SRS short form may possess superior psychometric properties compared to the original scale and emerge as a more precise measure of ASD core symptom severity, facilitating research and practice. Future research using IRT is needed to further refine existing measures of autism symptomatology. © 2017 Association for Child and Adolescent Mental Health.

Time Course of the Rabbit's Conditioned Nictitating Membrane Movements during Acquisition, Extinction, and Reacquisition

ERIC Educational Resources Information Center

Kehoe, E. James; Ludvig, Elliot A.; Sutton, Richard S.

2014-01-01

The present experiment tested whether or not the time course of a conditioned eyeblink response, particularly its duration, would expand and contract, as the magnitude of the conditioned response (CR) changed massively during acquisition, extinction, and reacquisition. The CR duration remained largely constant throughout the experiment, while CR…

Transient photoconductivity in the ferromagnetic semiconductor CdCr2Se4

NASA Technical Reports Server (NTRS)

Walser, A. D.; Alfano, R. R.

1988-01-01

The transient photoconductive response time of the ferromagnetic semiconductor CdCr2Se4 was measured to be smaller than 90 ps, the response time of the scope. The measurements were performed at room temperature (300 K) for 0.53 and 1.06 microns excitations using a mode locked frequency-doubled YAG laser.

Development of a subjective cognitive decline questionnaire using item response theory: a pilot study.

PubMed

Gifford, Katherine A; Liu, Dandan; Romano, Raymond; Jones, Richard N; Jefferson, Angela L

2015-12-01

Subjective cognitive decline (SCD) may indicate unhealthy cognitive changes, but no standardized SCD measurement exists. This pilot study aims to identify reliable SCD questions. 112 cognitively normal (NC, 76±8 years, 63% female), 43 mild cognitive impairment (MCI; 77±7 years, 51% female), and 33 diagnostically ambiguous participants (79±9 years, 58% female) were recruited from a research registry and completed 57 self-report SCD questions. Psychometric methods were used for item-reduction. Factor analytic models assessed unidimensionality of the latent trait (SCD); 19 items were removed with extreme response distribution or trait-fit. Item response theory (IRT) provided information about question utility; 17 items with low information were dropped. Post-hoc simulation using computerized adaptive test (CAT) modeling selected the most commonly used items (n=9 of 21 items) that represented the latent trait well (r=0.94) and differentiated NC from MCI participants (F(1,146)=8.9, p=0.003). Item response theory and computerized adaptive test modeling identified nine reliable SCD items. This pilot study is a first step toward refining SCD assessment in older adults. Replication of these findings and validation with Alzheimer's disease biomarkers will be an important next step for the creation of a SCD screener.

Cross-Cultural Validation of the Quality of Life in Hand Eczema Questionnaire (QOLHEQ).

PubMed

Ofenloch, Robert F; Oosterhaven, Jart A F; Susitaival, Päivikki; Svensson, Åke; Weisshaar, Elke; Minamoto, Keiko; Onder, Meltem; Schuttelaar, Marie Louise A; Bulbul Baskan, Emel; Diepgen, Thomas L; Apfelbacher, Christian

2017-07-01

The Quality of Life in Hand Eczema Questionnaire (QOLHEQ) is the only instrument assessing disease-specific health-related quality of life in patients with hand eczema. It is available in eight language versions. In this study we assessed if the items of different language versions of the QOLHEQ yield comparable values across countries. An international multicenter study was conducted with participating centers in Finland, Germany, Japan, The Netherlands, Sweden, and Turkey. Methods of item response theory were applied to each subscale to assess differential item functioning for items among countries. Overall, 662 hand eczema patients were recruited into the study. Single items were removed or split according to the item response theory model by country to resolve differential item functioning. After this adjustment, none of the four subscales of the QOLHEQ showed significant misfit to the item response theory model (P < 0.01), and a Person Separation Index of greater than 0.7 showed good internal consistency for each subscale. By adapting the scoring of the QOLHEQ using the methods of item response theory, it was possible to obtain QOLHEQ values that are comparable across countries. Cross-cultural variations in the interpretation of single items were resolved. The QOLHEQ is now ready to be used in international studies assessing the health-related quality of life impact of hand eczema. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Analyzing force concept inventory with item response theory

NASA Astrophysics Data System (ADS)

Wang, Jing; Bao, Lei

2010-10-01

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

Item Response Theory Models for Performance Decline during Testing

ERIC Educational Resources Information Center

Jin, Kuan-Yu; Wang, Wen-Chung

2014-01-01

Sometimes, test-takers may not be able to attempt all items to the best of their ability (with full effort) due to personal factors (e.g., low motivation) or testing conditions (e.g., time limit), resulting in poor performances on certain items, especially those located toward the end of a test. Standard item response theory (IRT) models fail to…

The Effect of Error in Item Parameter Estimates on the Test Response Function Method of Linking.

ERIC Educational Resources Information Center

Kaskowitz, Gary S.; De Ayala, R. J.

2001-01-01

Studied the effect of item parameter estimation for computation of linking coefficients for the test response function (TRF) linking/equating method. Simulation results showed that linking was more accurate when there was less error in the parameter estimates, and that 15 or 25 common items provided better results than 5 common items under both…

Standard Errors and Confidence Intervals from Bootstrapping for Ramsay-Curve Item Response Theory Model Item Parameters

ERIC Educational Resources Information Center

Gu, Fei; Skorupski, William P.; Hoyle, Larry; Kingston, Neal M.

2011-01-01

Ramsay-curve item response theory (RC-IRT) is a nonparametric procedure that estimates the latent trait using splines, and no distributional assumption about the latent trait is required. For item parameters of the two-parameter logistic (2-PL), three-parameter logistic (3-PL), and polytomous IRT models, RC-IRT can provide more accurate estimates…

The utility of a classificatory decision tree approach to assist clinical differentiation of melancholic and non-melancholic depression.

PubMed

Parker, G; McCraw, S; Hadzi-Pavlovic, D

2015-07-15

Studies suggest that differentiating melancholic from non-melancholic depressive disorders is advanced by use of illness course as well as symptom variables but, in practice, potentially differentiating variables are generally positioned as having equal value. Judging that differentiating features are more likely to vary in their signal intensity, we sought to determine the number of features required to effect differentiation and their hierarchical order. The 24-item clinician-rated Sydney Melancholia Prototype Index (SMPI-CR) was completed for 364 unipolar depressed patients. The sample was divided into two cohorts according to the recruitment period. An RPART classification tree analysis identified the most discriminating SMPI items in the development sample of 197 patients, and examined the sensitivity and specificity of the diagnostic decisions, then sought to replicate findings in a validation sample of 169 patients. Independent analyses of putative SMPI items identified only seven items as required to discriminate those with clinically-diagnosed melancholic or non-melancholic depression when the conditions were examined separately. An RPART analysis considering differentiation of melancholic and non-melancholic depression in the total samples retained five of those items in the classification tree, three of which were non-symptom items, and with 92% sensitivity and 80% specificity in the development sample. This reduced item set showed 93% sensitivity and 82% specificity in the validation sample. Our clinical judgment of melancholic or non-melancholic depression may not correspond with the clinical logic employed by other clinicians. Only five SMPI items were required to derive a succinct and efficient decision tree, comprising high sensitivity and specificity in differentiating melancholic and non-melancholic depression. Current study findings provide an empirical model that could enrich clinicians׳ approach to differentiating melancholic and non-melancholic depression. Copyright © 2015 Elsevier B.V. All rights reserved.

Chromium toxicity tolerance of Solanum nigrum L. and Parthenium hysterophorus L. plants with reference to ion pattern, antioxidation activity and root exudation.

PubMed

UdDin, Islam; Bano, Asghari; Masood, Sajid

2015-03-01

Chromium (Cr), being a highly toxic metal, adversely affects the mineral uptake and metabolic processes in plants when present in excess. The current study was aimed at investigating the Cr accumulation in various plant tissues and its relation to the antioxidation activity and root exudation. Plants were grown in soil spiked with different concentrations of Cr for three weeks in pots and analysed for different growth, antioxidants and ion attributes. Furthermore, plants treated with different concentrations of Cr in pots were shifted to rhizobox-like system for 48h and organic acids were monitored in the mucilage dissolved from the plant root surface, mirroring rhizospheric solution. The results revealed that the Cr application at 1mM increased the shoot fresh and dry weight and root dry weight of Solanum nigrum, whereas the opposite was observed for Parthenium hysterophorus when compared with lower levels of Cr (0.5mM) or control treatment. In both plant species, Cr and Cl concentrations were increased while Ca, Mg and K concentrations in root, shoot and root exudates were decreased with increasing levels of Cr. Higher levels of Cr treatments enhanced the activities of SOD, POD and proline content in leaves of S. nigrum, whereas lower levels of Cr treatment were found to have stimulatory effects in P. hysterophorus. P. hysterophorus exhibited highest exudation of organic acid contents. With increasing levels of Cr treatments, citric acid concentration in root exudates increased by 35% and 44% in S. nigrum, whereas 20% and 76% in P. hysterophorus. Cr toxicity was responsible for the shoot growth reduction of S. nigrum and P. hysterophorus, however, shoot growth response was different at different levels of applied Cr. Consequently, Cr stress negatively altered the plant physiology and biochemistry. However, the enhanced antioxidant production, Cl uptake and root exudation are the physiological and biochemical indicators for the plant adaptations in biotic systems polluted with Cr. Copyright © 2014 Elsevier Inc. All rights reserved.

Pathological complete response in patients with esophageal cancer after the trimodality approach: The association with baseline variables and survival-The University of Texas MD Anderson Cancer Center experience.

PubMed

Blum Murphy, Mariela; Xiao, Lianchum; Patel, Viren R; Maru, Dipen M; Correa, Arlene M; G Amlashi, Fatemeh; Liao, Zhongxing; Komaki, Ritsuko; Lin, Steven H; Skinner, Heath D; Vaporciyan, Ara; Walsh, Garrett L; Swisher, Stephen G; Sepesi, Boris; Lee, Jeffrey H; Bhutani, Manoop S; Weston, Brian; Hofstetter, Wayne L; Ajani, Jaffer A

2017-11-01

Reports are limited regarding clinical and pretreatment features that might predict a pathological complete response (pathCR) after treatment in patients with esophageal cancer (EC). This might allow patient selection for different strategies. This study examines the association of a pathCR with pretreatment variables, overall survival (OS), recurrence-free survival (RFS), and patterns of recurrence in a large cohort from a single institution. The baseline clinical features of 911 consecutive patients with EC who were treated with trimodality therapy from January 2000 to November 2013 were analyzed. A pathCR was defined as a surgical specimen with no residual carcinoma (primary or nodes). Logistic regressions were used to identify independent baseline features associated with a pathCR. We applied log-rank testing and Cox models to determine the association between a pathCR and the time-to-event outcomes (OS and RFS). Of 911 patients, 218 (23.9%) achieved a pathCR. The pathCR rate was 23.1% for adenocarcinoma and 32.2% for squamous cell carcinoma. A lower pathCR rate was observed for 1) older patients (>60 years), 2) patients with poorly differentiated tumors, 3) patients with signet ring cells (SRCs), and 4) patients with a higher T stage. Patients with a pathCR had longer OS and RFS than those without a pathCR (P = .0021 and P = .0011, respectively). Recurrences occurred more in non-pathCR patients. Distant metastases were the most common type of recurrence. PathCR patients developed brain metastases at a marginally higher rate than non-pathCR patients (P = .051). In this large cohort study, a pathCR is confirmed to be associated with better OS and RFS. The presence of a poorly differentiated tumor or SRCs reduces the likelihood of a pathCR. Future research should focus on molecular classifiers. Cancer 2017;123:4106-4113. © 2017 American Cancer Society. © 2017 American Cancer Society.

Psychometric analysis of the Generalized Anxiety Disorder scale (GAD-7) in primary care using modern item response theory.

PubMed

Jordan, Pascal; Shedden-Mora, Meike C; Löwe, Bernd

2017-01-01

The Generalized Anxiety Disorder scale (GAD-7) is one of the most frequently used diagnostic self-report scales for screening, diagnosis and severity assessment of anxiety disorder. Its psychometric properties from the view of the Item Response Theory paradigm have rarely been investigated. We aimed to close this gap by analyzing the GAD-7 within a large sample of primary care patients with respect to its psychometric properties and its implications for scoring using Item Response Theory. Robust, nonparametric statistics were used to check unidimensionality of the GAD-7. A graded response model was fitted using a Bayesian approach. The model fit was evaluated using posterior predictive p-values, item information functions were derived and optimal predictions of anxiety were calculated. The sample included N = 3404 primary care patients (60% female; mean age, 52,2; standard deviation 19.2) The analysis indicated no deviations of the GAD-7 scale from unidimensionality and a decent fit of a graded response model. The commonly suggested ultra-brief measure consisting of the first two items, the GAD-2, was supported by item information analysis. The first four items discriminated better than the last three items with respect to latent anxiety. The information provided by the first four items should be weighted more heavily. Moreover, estimates corresponding to low to moderate levels of anxiety show greater variability. The psychometric validity of the GAD-2 was supported by our analysis.

Psychometric analysis of the Generalized Anxiety Disorder scale (GAD-7) in primary care using modern item response theory

PubMed Central

Shedden-Mora, Meike C.; Löwe, Bernd

2017-01-01

Objective The Generalized Anxiety Disorder scale (GAD-7) is one of the most frequently used diagnostic self-report scales for screening, diagnosis and severity assessment of anxiety disorder. Its psychometric properties from the view of the Item Response Theory paradigm have rarely been investigated. We aimed to close this gap by analyzing the GAD-7 within a large sample of primary care patients with respect to its psychometric properties and its implications for scoring using Item Response Theory. Methods Robust, nonparametric statistics were used to check unidimensionality of the GAD-7. A graded response model was fitted using a Bayesian approach. The model fit was evaluated using posterior predictive p-values, item information functions were derived and optimal predictions of anxiety were calculated. Results The sample included N = 3404 primary care patients (60% female; mean age, 52,2; standard deviation 19.2) The analysis indicated no deviations of the GAD-7 scale from unidimensionality and a decent fit of a graded response model. The commonly suggested ultra-brief measure consisting of the first two items, the GAD-2, was supported by item information analysis. The first four items discriminated better than the last three items with respect to latent anxiety. Conclusion The information provided by the first four items should be weighted more heavily. Moreover, estimates corresponding to low to moderate levels of anxiety show greater variability. The psychometric validity of the GAD-2 was supported by our analysis. PMID:28771530

Do large-scale assessments measure students' ability to integrate scientific knowledge?

NASA Astrophysics Data System (ADS)

Lee, Hee-Sun

2010-03-01

Large-scale assessments are used as means to diagnose the current status of student achievement in science and compare students across schools, states, and countries. For efficiency, multiple-choice items and dichotomously-scored open-ended items are pervasively used in large-scale assessments such as Trends in International Math and Science Study (TIMSS). This study investigated how well these items measure secondary school students' ability to integrate scientific knowledge. This study collected responses of 8400 students to 116 multiple-choice and 84 open-ended items and applied an Item Response Theory analysis based on the Rasch Partial Credit Model. Results indicate that most multiple-choice items and dichotomously-scored open-ended items can be used to determine whether students have normative ideas about science topics, but cannot measure whether students integrate multiple pieces of relevant science ideas. Only when the scoring rubric is redesigned to capture subtle nuances of student open-ended responses, open-ended items become a valid and reliable tool to assess students' knowledge integration ability.

Accounting for Local Dependence with the Rasch Model: The Paradox of Information Increase.

PubMed

Andrich, David

Test theories imply statistical, local independence. Where local independence is violated, models of modern test theory that account for it have been proposed. One violation of local independence occurs when the response to one item governs the response to a subsequent item. Expanding on a formulation of this kind of violation between two items in the dichotomous Rasch model, this paper derives three related implications. First, it formalises how the polytomous Rasch model for an item constituted by summing the scores of the dependent items absorbs the dependence in its threshold structure. Second, it shows that as a consequence the unit when the dependence is accounted for is not the same as if the items had no response dependence. Third, it explains the paradox, known, but not explained in the literature, that the greater the dependence of the constituent items the greater the apparent information in the constituted polytomous item when it should provide less information.

Pathway level alterations rather than mutations in single genes predict response to HER2-targeted therapies in the neo-ALTTO trial.

PubMed

Shi, W; Jiang, T; Nuciforo, P; Hatzis, C; Holmes, E; Harbeck, N; Sotiriou, C; Peña, L; Loi, S; Rosa, D D; Chia, S; Wardley, A; Ueno, T; Rossari, J; Eidtmann, H; Armour, A; Piccart-Gebhart, M; Rimm, D L; Baselga, J; Pusztai, L

2017-01-01

We performed whole-exome sequencing of pretreatment biopsies and examined whether genome-wide metrics of overall mutational load, clonal heterogeneity or alterations at variant, gene, and pathway levels are associated with treatment response and survival. Two hundred and three biopsies from the NeoALTTO trial were analyzed. Mutations were called with MuTect, and Strelka, using pooled normal DNA. Associations between DNA alterations and outcome were evaluated by logistic and Cox-proportional hazards regression. There were no recurrent single gene mutations significantly associated with pathologic complete response (pCR), except PIK3CA [odds ratio (OR) = 0.42, P = 0.0185]. Mutations in 33 of 714 pathways were significantly associated with response, but different genes were affected in different individuals. PIK3CA was present in 23 of these pathways defining a ‘trastuzumab resistance-network’ of 459 genes. Cases with mutations in this network had low pCR rates to trastuzumab (2/50, 4%) compared with cases with no mutations (9/16, 56%), OR = 0.035; P < 0.001. Mutations in the ‘Regulation of RhoA activity’ pathway were associated with higher pCR rate to lapatinib (OR = 14.8, adjusted P = 0.001), lapatinib + trastuzumab (OR = 3.0, adjusted P = 0.09), and all arms combined (OR = 3.77, adjusted P = 0.02). Patients (n = 124) with mutations in the trastuzumab resistance network but intact RhoA pathway had 2% (1/41) pCR rate with trastuzumab alone (OR = 0.026, P = 0.001) but adding lapatinib increased pCR rate to 45% (17/38, OR = 1.68, P = 0.3). Patients (n = 46) who had no mutations in either gene set had 6% pCR rate (1/15) with lapatinib, but had the highest pCR rate, 52% (8/15) with trastuzumab alone. Mutations in the RhoA pathway are associated with pCR to lapatinib and mutations in a PIK3CA-related network are associated with resistance to trastuzumab. The combined mutation status of these two pathways could define patients with very low response rate to trastuzumab alone that can be augmented by adding lapatinib or substituting trastuzumab with lapatinib.

A Planned Neck Dissection Is Not Necessary in All Patients With N2-3 Head-and-Neck Cancer After Sequential Chemoradiotherapy

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

Soltys, Scott G., E-mail: sgsoltys@stanford.edu; Choi, Clara Y.H.; Fee, Willard E.

2012-07-01

Purpose: To assess the role of a planned neck dissection (PND) after sequential chemoradiotherapy for patients with head-and-neck cancer with N2-N3 nodal disease. Methods and Materials: We reviewed 90 patients with N2-N3 head-and-neck squamous cell carcinoma treated between 1991 and 2001 on two sequential chemoradiotherapy protocols. All patients received induction and concurrent chemotherapy with cisplatin and 5-fluorocuracil, with or without tirapazamine. Patients with less than a clinical complete response (cCR) in the neck proceeded to a PND after chemoradiation. The primary endpoint was nodal response. Clinical outcomes and patterns of failure were analyzed. Results: The median follow-up durations for livingmore » and all patients were 8.3 years (range, 1.5-16.3 year) and 5.4 years (range, 0.6-16.3 years), respectively. Of the 48 patients with nodal cCR whose necks were observed, 5 patients had neck failures as a component of their recurrence [neck and primary (n = 2); neck, primary, and distant (n = 1); neck only (n = 1); neck and distant (n = 1)]. Therefore, PND may have benefited only 2 patients (4%) [neck only failure (n = 1); neck and distant failure (n = 1)]. The pathologic complete response (pCR) rate for those with a clinical partial response (cPR) undergoing PND (n = 30) was 53%. The 5-year neck control rates after cCR, cPR{yields}pCR, and cPR{yields}pPR were 90%, 93%, and 78%, respectively (p = 0.36). The 5-year disease-free survival rates for the cCR, cPR{yields}pCR, and cPR{yields}pPR groups were 53%, 75%, and 42%, respectively (p = 0.04). Conclusion: In our series, patients with N2-N3 neck disease achieving a cCR in the neck, PND would have benefited only 4% and, therefore, is not recommended. Patients with a cPR should be treated with PND. Residual tumor in the PND specimens was associated with poor outcomes; therefore, aggressive therapy is recommended. Studies using novel imaging modalities are needed to better assess treatment response.« less

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

Rojas-Herrera, J., E-mail: jimmy06@mit.edu; Rinderknecht, H. G.; Zylstra, A. B.

The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray fluences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K{sub α} and K{sub β} x-rays. The CR-39 detectors were then exposed to 1–5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those notmore » exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.« less

Homologous Recombination and Translesion DNA Synthesis Play Critical Roles on Tolerating DNA Damage Caused by Trace Levels of Hexavalent Chromium

PubMed Central

Chen, Youjun; Zhou, Yi-Hui; Neo, Dayna; Clement, Jean; Takata, Minoru; Takeda, Shunichi; Sale, Julian; Wright, Fred A.; Swenberg, James A.; Nakamura, Jun

2016-01-01

Contamination of potentially carcinogenic hexavalent chromium (Cr(VI)) in the drinking water is a major public health concern worldwide. However, little information is available regarding the biological effects of a nanomoler amount of Cr(VI). Here, we investigated the genotoxic effects of Cr(VI) at nanomoler levels and their repair pathways. We found that DNA damage response analyzed based on differential toxicity of isogenic cells deficient in various DNA repair proteins is observed after a three-day incubation with K2CrO4 in REV1-deficient DT40 cells at 19.2 μg/L or higher as well as in TK6 cells deficient in polymerase delta subunit 3 (POLD3) at 9.8 μg/L or higher. The genotoxicity of Cr(VI) decreased ~3000 times when the incubation time was reduced from three days to ten minutes. TK mutation rate also significantly decreased from 6 day to 1 day exposure to Cr(VI). The DNA damage response analysis suggest that DNA repair pathways, including the homologous recombination and REV1- and POLD3-mediated error-prone translesion synthesis pathways, are critical for the cells to tolerate to DNA damage caused by trace amount of Cr(VI). PMID:27907204

Gas sensing behaviour of Cr{sub 2}O{sub 3} and W{sup 6+}: Cr{sub 2}O{sub 3} nanoparticles towards acetone

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

Kohli, Nipin, E-mail: nipinkohli82@yahoo.com; Hastir, Anita; Singh, Ravi Chand

2016-05-23

This paper reports the acetone gas sensing properties of Cr{sub 2}O{sub 3} and 2% W{sup 6+} doped Cr{sub 2}O{sub 3} nanoparticles. The simple cost-effective hydrolysis assisted co-precipitation method was adopted. Synthesized samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) techniques. XRD revealed that synthesized nanoparticles have corundum structure. The lattice parameters have been calculated by Rietveld refinement; and strain and crystallite size have been calculated by using the Williamson-Hall plots. For acetone gas sensing properties, the nanoparticles were applied as thick film onto alumina substrate and tested at different operating temperatures. The results showedmore » that the optimum operating temperature of both the gas sensors is 250°C. At optimum operating temperature, the response of Cr{sub 2}O{sub 3} and 2% W{sup 6+} doped Cr{sub 2}O{sub 3} gas sensor towards 100 ppm acetone was found to be 25.5 and 35.6 respectively. The investigations revealed that the addition of W{sup 6+} as a dopant enhanced the sensing response of Cr{sub 2}O{sub 3} nanoparticles appreciably.« less

Item Order, Response Format, and Examinee Sex and Handedness and Performance on a Multiple-Choice Test.

ERIC Educational Resources Information Center

Kleinke, David J.

Four forms of a 36-item adaptation of the Stanford Achievement Test were administered to 484 fourth graders. External factors potentially influencing test performance were examined, namely: (1) item order (easy-to-difficult vs. uniform); (2) response location (left column vs. right column); (3) handedness which may interact with response location;…

Person Response Functions and the Definition of Units in the Social Sciences

ERIC Educational Resources Information Center

Engelhard, George, Jr.; Perkins, Aminah F.

2011-01-01

Humphry (this issue) has written a thought-provoking piece on the interpretation of item discrimination parameters as scale units in item response theory. One of the key features of his work is the description of an item response theory (IRT) model that he calls the logistic measurement function that combines aspects of two traditions in IRT that…

On the Relationship between Classical Test Theory and Item Response Theory: From One to the Other and Back

ERIC Educational Resources Information Center

Raykov, Tenko; Marcoulides, George A.

2016-01-01

The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete…

Applications of Multidimensional Item Response Theory Models with Covariates to Longitudinal Test Data. Research Report. ETS RR-16-21

ERIC Educational Resources Information Center

Fu, Jianbin

2016-01-01

The multidimensional item response theory (MIRT) models with covariates proposed by Haberman and implemented in the "mirt" program provide a flexible way to analyze data based on item response theory. In this report, we discuss applications of the MIRT models with covariates to longitudinal test data to measure skill differences at the…

Bayesian Analysis of Item Response Curves. Research Report 84-1. Mathematical Sciences Technical Report No. 132.

ERIC Educational Resources Information Center

Tsutakawa, Robert K.; Lin, Hsin Ying

Item response curves for a set of binary responses are studied from a Bayesian viewpoint of estimating the item parameters. For the two-parameter logistic model with normally distributed ability, restricted bivariate beta priors are used to illustrate the computation of the posterior mode via the EM algorithm. The procedure is illustrated by data…

Modeling Answer Change Behavior: An Application of a Generalized Item Response Tree Model

ERIC Educational Resources Information Center

Jeon, Minjeong; De Boeck, Paul; van der Linden, Wim

2017-01-01

We present a novel application of a generalized item response tree model to investigate test takers' answer change behavior. The model allows us to simultaneously model the observed patterns of the initial and final responses after an answer change as a function of a set of latent traits and item parameters. The proposed application is illustrated…

Item response theory analysis of Working Alliance Inventory, revised response format, and new Brief Alliance Inventory.

PubMed

Mallinckrodt, Brent; Tekie, Yacob T

2016-11-01

The Working Alliance Inventory (WAI) has made great contributions to psychotherapy research. However, studies suggest the 7-point response format and 3-factor structure of the client version may have psychometric problems. This study used Rasch item response theory (IRT) to (a) improve WAI response format, (b) compare two brief 12-item versions (WAI-sr; WAI-s), and (c) develop a new 16-item Brief Alliance Inventory (BAI). Archival data from 1786 counseling center and community clients were analyzed. IRT findings suggested problems with crossed category thresholds. A rescoring scheme that combines neighboring responses to create 5- and 4-point scales sharply reduced these problems. Although subscale variance was reduced by 11-26%, rescoring yielded improved reliability and generally higher correlations with therapy process (session depth and smoothness) and outcome measures (residual gain symptom improvement). The 16-item BAI was designed to maximize "bandwidth" of item difficulty and preserve a broader range of WAI sensitivity than WAI-s or WAI-sr. Comparisons suggest the BAI performed better in several respects than the WAI-s or WAI-sr and equivalent to the full WAI on several performance indicators.

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

Igidbashian, Levon, E-mail: levonig@hotmail.co; Fortin, Bernard; Guertin, Louis

Purpose: To evaluate the role of neck dissection (ND) after chemoradiation therapy (CRT) for head and neck squamous cell carcinoma (HNSCC) with N3 disease. Methods and Materials: From March 1998 to September 2006, 70 patients with HNSCC and N3 neck disease were treated with concomitant CRT as primary therapy. Response to treatment was assessed using clinical examination and computed tomography 6 to 8 weeks posttreatment. Neck dissection was not routinely performed and considered for those with less than complete response. Of the patients, 26 (37.1%) achieved clinical complete response (cCR) after CRT. A total of 31 (44.3%) underwent ND aftermore » partial response (cPR-ND). Thirteen patients (29.5%) did not achieve cCR and did not undergo ND for the following reasons: incomplete response/progression at primary site, refusal/contraindication to surgery, metastatic progression, or death. These patients were excluded from the analysis. Outcomes were computed using Kaplan-Meier curves and were compared with log rank tests. Results: Comparing the cCR and cPR-ND groups at 2 years, the disease-free survival was respectively 62.7% and 84.9% (p = 0.048); overall survival was 63.0% and 79.4% (p = 0.26), regional relapse-free survival was 87.8% and 96.0% (p = 0.21); and distant disease-free survival was 67.1% and 92.6% (p = 0.059). In the cPR-ND group, 71.0% had no pathologic evidence of disease (PPV of 29.0%). Conclusions: Patients with N3 disease achieving regional cPR and primary cCR who underwent ND seemed to have better outcomes than patients achieving global cCR without ND. Clinical assessment with computed tomography is not adequate for evaluating response to treatment. Because of the inherent limitations of our study, further confirmatory studies are warranted.« less

TU-G-BRA-06: PET-Based Treatment Response Assessement for Neoadjuvent Chemoradiation for Pancreatic Adenocarcinoma

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

Dalah, E; Tai, A; Oshima, K

Purpose: To address the limitations of the conventional response evaluation criteria in solid tumors (RECIST), and validate PET response criteria in solid tumors (PERCIST1.0). We analyze the relationship between the pathological treatment response (PTR) and PERCIST1.0 for patients treated with neoadjuvent chemoradiation (nCR) for pancreatic adenocarcinoma. Methods: The pre- and post-nCR CT and PET data for a total of 8 patients with resectable, or borderline resectable pancreatic head adenocarcinoma treated with nCR were retrospectively analyzed. These data were compared with the PTR which were graded according to tumor cell destruction (cellularity), with Grade1, 2 or 3 (G1, G2 or G3)more » for good, moderate, and poor responses, respectively. RECIST-based PET (RECISTPET), and PERCIST1.0 were defined using lean body mass normalized SUV (nSUVlb). RECIST-based CT (RECISTCT) was defined by contouring the whole pancreas head (CTPH). Pre- and post-nSUVlb and SUVbw, PERCIST 1.0, were correlated with PTR using Pearson’s correlation coefficient test. Results: The average mean and SD in nSUVlb for all 8 patients analyzed were lower in post-nCR (1.35±0.34) compared to those at pre-nCR (1.38±0.20). Using PERCIST1.0, 5/8 patients showed stable metabolic disease (SMD), 2/8 partial metabolic response (PMR), and 1/8 progressive metabolic disease (PMD). Using RECISTPET 4/8 showed stable disease (STD), 4/8 partial response (PR), whereas 8/8 showed stable disease (STD) using RECISTCT. PTR were correlated with PERCIST1.0 (R=0.3780/P=0.6071). Pathological tumor size was correlated with RECISTCT (R=0.0727/P=0.8679), and RECISTPET, R=−0.3333/P=0.3798. Conclusion: Chemoradiation treatment response assessment based on metabolic tumor activities using PRECIST1.0 and RECISTPET appears to provide better agreement with pathological assessment as compared to the conventional CT-based assessment using RECISTCT. The integration of these additional radiographic metrics in assessing treatment response to nCR for pancreatic adenocarcinoma may provide a promising strategy to better select those patients most suitable for therapeutic intensification.« less

Mechanisms of chromium (VI)-induced apoptosis in anterior pituitary cells.

PubMed

Quinteros, Fernanda A; Machiavelli, Leticia I; Miler, Eliana A; Cabilla, Jimena P; Duvilanski, Beatriz H

2008-07-30

Hexavalent chromium (Cr (VI)) is a highly toxic metal. Exposure to Cr (VI) compounds may affect reproductive functions. Due to the importance of anterior pituitary hormones on reproductive physiology we have studied the effects of Cr (VI) on anterior pituitary. We previously demonstrated that, after in vivo Cr (VI) administration, Cr accumulates in the pituitary gland and affects prolactin secretion. In vitro, Cr (VI) causes apoptosis in anterior pituitary cells due to oxidative stress generation. To better understand the mechanisms involved in Cr (VI)-induced apoptosis we studied: (a) whether Cr (VI) affects the intracellular antioxidant response and (b) which of the apoptotic factors participates in Cr (VI) effect. Our results show that Cr (VI) treatment induces a decrease in catalase and glutathione peroxidase (GPx) activity but does not modify glutathione reductase (GR) activity. Cr (VI) exposure causes an increase of GSH levels. p53 and Bax mRNA are also upregulated by the metal. Pifithrin alpha, a p53 transcriptional inhibitor, increases Cr (VI) cytotoxicity, suggesting a role of p53 as a survival molecule. The antioxidant N-acetyl-cysteine (NAC) could prevent Bax mRNA increase and caspase 3 activation, confirming that Cr (VI)-induced apoptosis involves oxidative stress generation.

Patterns of relapse from a phase 3 Study of response-based therapy for intermediate-risk Hodgkin lymphoma (AHOD0031): a report from the Children's Oncology Group.

PubMed

Dharmarajan, Kavita V; Friedman, Debra L; Schwartz, Cindy L; Chen, Lu; FitzGerald, T J; McCarten, Kathleen M; Kessel, Sandy K; Iandoli, Matt; Constine, Louis S; Wolden, Suzanne L

2015-05-01

The study was designed to determine whether response-based therapy improves outcomes in intermediate-risk Hodgkin lymphoma. We examined patterns of first relapse in the study. From September 2002 to July 2010, 1712 patients <22 years old with stage I-IIA with bulk, I-IIAE, I-IIB, and IIIA-IVA with or without doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide were enrolled. Patients were categorized as rapid (RER) or slow early responders (SER) after 2 cycles of doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide (ABVE-PC). The SER patients were randomized to 2 additional ABVE-PC cycles or augmented chemotherapy with 21 Gy involved field radiation therapy (IFRT). RER patients were stipulated to undergo 2 additional ABVE-PC cycles and were then randomized to 21 Gy IFRT or no further treatment if complete response (CR) was achieved. RER without CR patients were non-randomly assigned to 21 Gy IFRT. Relapses were characterized without respect to site (initial, new, or both; and initial bulk or initial nonbulk), and involved field radiation therapy field (in-field, out-of-field, or both). Patients were grouped by treatment assignment (SER; RER/no CR; RER/CR/IFRT; and RER/CR/no IFRT). Summary statistics were reported. At 4-year median follow-up, 244 patients had experienced relapse, 198 of whom were fully evaluable for review. Those who progressed during treatment (n=30) or lacked relapse imaging (n=16) were excluded. The median time to relapse was 12.8 months. Of the 198 evaluable patients, 30% were RER/no CR, 26% were SER, 26% were RER/CR/no IFRT, 16% were RER/CR/IFRT, and 2% remained uncategorized. The 74% and 75% relapses involved initially bulky and nonbulky sites, respectively. First relapses rarely occurred at exclusively new or out-of-field sites. By contrast, relapses usually occurred at nodal sites of initial bulky and nonbulky disease. Although response-based therapy has helped define treatment for selected RER patients, it has not improved outcome for SER patients or facilitated refinement of IFRT volumes or doses. Copyright © 2015 Elsevier Inc. All rights reserved.

SU-E-J-271: Correlation of CT Number Change with Radiation Treatment Response for Pancreatic Cancer

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

Dalah, E; Tai, A; Oshima, K

Purpose: It has been reported recently that radiation can induce CT number (CTN) change during radiation therapy (RT) delivery. In the effort to explore whether CTN can be used to assess RT response, we analyze the relationship between the pathological treatment response (PTR) and the changes of CTN, MRI, and PET before and after the neoadjuvant chemoradiation (nCR) for pancreatic adenocarcinoma. Methods: The preand post-nCR CT, MRI, and PET data for a total of 8 patients with resectable, or borderline resectable pancreatic head adenocarcinoma treated with nCR were retrospectively analyzed. Radiographic characteristics were correlated to PTR data. The histograms, meansmore » and standard derivations (SD) of the CTNs in pancreatic head (CTNPH), the GTV defined by ADC (CTNGTV), and the rest of pancreatic head (CTNPH-CTNGTV) were compared. Changes before and after nCR were correlated with the corresponding changes of ADC, lean body mass normalized SUV (SUVlb), and PTR using Pearson’ s correlation coefficient test. Results: The average mean and SD in CTPH for all the patients analyzed were higher in post-nCR (53.17 ± 31.05 HU) compared to those at pre-nCR (28.09 ± 4.253 HU). The CTNGTV were generally higher than CTNPH and CTNPH-CTNGTV, though the differences were not significant. The post-nCR changes of mean CTN, ADC, and SUVlb values in pancreatic head were correlated with PTR (R=0.3273/P=0.5357, R=−0.5455/P<0.0001, and R=0.7638/P=0.0357, respectively). The mean difference in the maximum tumor dimension measured from CTN, ADC, and SUVlb as compared with pathological measurements was −2.1, −0.5, and 0.22 cm, respectively. Conclusion: The radiation-induced change of CTN in pancreas head after chemoradiation therapy of pancreatic cancer was observed, which may be related to treatment responses as assessed by biological imaging and pathology. More data are needed to determine whether the CTN can be used as a quantitative biomarker for response to neoadjuvant therapy.« less

An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor

PubMed Central

Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

2016-01-01

Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor. PMID:27021522

Quantitative contrast-enhanced ultrasound evaluation of pathological complete response in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy.

PubMed

Wan, Cai-Feng; Liu, Xue-Song; Wang, Lin; Zhang, Jie; Lu, Jin-Song; Li, Feng-Hua

2018-06-01

To clarify whether the quantitative parameters of contrast-enhanced ultrasound (CEUS) can be used to predict pathological complete response (pCR) in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy (NAC). Fifty-one patients with histologically proved locally advanced breast cancer scheduled for NAC were enrolled. The quantitative data for CEUS and the tumor diameter were collected at baseline and before surgery, and compared with the pathological response. Multiple logistic regression analysis was performed to examine quantitative parameters at CEUS and the tumor diameter to predict the pCR, and receiver operating characteristic (ROC) curve analysis was used as a summary statistic. Multiple logistic regression analysis revealed that PEAK (the maximum intensity of the time-intensity curve during bolus transit), PEAK%, TTP% (time to peak), and diameter% were significant independent predictors of pCR, and the area under the ROC curve was 0.932(Az 1 ), and the sensitivity and specificity to predict pCR were 93.7% and 80.0%. The area under the ROC curve for the quantitative parameters was 0.927(Az 2 ), and the sensitivity and specificity to predict pCR were 81.2% and 94.3%. For diameter%, the area under the ROC curve was 0.786 (Az 3 ), and the sensitivity and specificity to predict pCR were 93.8% and 54.3%. The values of Az 1 and Az 2 were significantly higher than that of Az 3 (P = 0.027 and P = 0.034, respectively). However, there was no significant difference between the values of Az 1 and Az 2 (P = 0.825). Quantitative analysis of tumor blood perfusion with CEUS is superior to diameter% to predict pCR, and can be used as a functional technique to evaluate tumor response to NAC. Copyright © 2018. Published by Elsevier B.V.

Measuring Response Styles Across the Big Five: A Multiscale Extension of an Approach Using Multinomial Processing Trees.

PubMed

Khorramdel, Lale; von Davier, Matthias

2014-01-01

This study shows how to address the problem of trait-unrelated response styles (RS) in rating scales using multidimensional item response theory. The aim is to test and correct data for RS in order to provide fair assessments of personality. Expanding on an approach presented by Böckenholt (2012), observed rating data are decomposed into multiple response processes based on a multinomial processing tree. The data come from a questionnaire consisting of 50 items of the International Personality Item Pool measuring the Big Five dimensions administered to 2,026 U.S. students with a 5-point rating scale. It is shown that this approach can be used to test if RS exist in the data and that RS can be differentiated from trait-related responses. Although the extreme RS appear to be unidimensional after exclusion of only 1 item, a unidimensional measure for the midpoint RS is obtained only after exclusion of 10 items. Both RS measurements show high cross-scale correlations and item response theory-based (marginal) reliabilities. Cultural differences could be found in giving extreme responses. Moreover, it is shown how to score rating data to correct for RS after being proved to exist in the data.

An item response theory evaluation of the young mania rating scale and the montgomery-asberg depression rating scale in the systematic treatment enhancement program for bipolar disorder (STEP-BD).

PubMed

Prisciandaro, James J; Tolliver, Bryan K

2016-11-15

The Young Mania Rating Scale (YMRS) and Montgomery-Asberg Depression Rating Scale (MADRS) are among the most widely used outcome measures for clinical trials of medications for Bipolar Disorder (BD). Nonetheless, very few studies have examined the measurement characteristics of the YMRS and MADRS in individuals with BD using modern psychometric methods. The present study evaluated the YMRS and MADRS in the Systematic Treatment Enhancement Program for BD (STEP-BD) study using Item Response Theory (IRT). Baseline data from 3716 STEP-BD participants were available for the present analysis. The Graded Response Model (GRM) was fit separately to YMRS and MADRS item responses. Differential item functioning (DIF) was examined by regressing a variety of clinically relevant covariates (e.g., sex, substance dependence) on all test items and on the latent symptom severity dimension, within each scale. Both scales: 1) contained several items that provided little or no psychometric information, 2) were inefficient, in that the majority of item response categories did not provide incremental psychometric information, 3) poorly measured participants outside of a narrow band of severity, 4) evidenced DIF for nearly all items, suggesting that item responses were, in part, determined by factors other than symptom severity. Limited to outpatients; DIF analysis only sensitive to certain forms of DIF. The present study provides evidence for significant measurement problems involving the YMRS and MADRS. More work is needed to refine these measures and/or develop suitable alternative measures of BD symptomatology for clinical trials research. Copyright © 2016 Elsevier B.V. All rights reserved.

Better assessment of physical function: item improvement is neglected but essential

PubMed Central

2009-01-01

Introduction Physical function is a key component of patient-reported outcome (PRO) assessment in rheumatology. Modern psychometric methods, such as Item Response Theory (IRT) and Computerized Adaptive Testing, can materially improve measurement precision at the item level. We present the qualitative and quantitative item-evaluation process for developing the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank. Methods The process was stepwise: we searched extensively to identify extant Physical Function items and then classified and selectively reduced the item pool. We evaluated retained items for content, clarity, relevance and comprehension, reading level, and translation ease by experts and patient surveys, focus groups, and cognitive interviews. We then assessed items by using classic test theory and IRT, used confirmatory factor analyses to estimate item parameters, and graded response modeling for parameter estimation. We retained the 20 Legacy (original) Health Assessment Questionnaire Disability Index (HAQ-DI) and the 10 SF-36's PF-10 items for comparison. Subjects were from rheumatoid arthritis, osteoarthritis, and healthy aging cohorts (n = 1,100) and a national Internet sample of 21,133 subjects. Results We identified 1,860 items. After qualitative and quantitative evaluation, 124 newly developed PROMIS items composed the PROMIS item bank, which included revised Legacy items with good fit that met IRT model assumptions. Results showed that the clearest and best-understood items were simple, in the present tense, and straightforward. Basic tasks (like dressing) were more relevant and important versus complex ones (like dancing). Revised HAQ-DI and PF-10 items with five response options had higher item-information content than did comparable original Legacy items with fewer response options. IRT analyses showed that the Physical Function domain satisfied general criteria for unidimensionality with one-, two-, three-, and four-factor models having comparable model fits. Correlations between factors in the test data sets were > 0.90. Conclusions Item improvement must underlie attempts to improve outcome assessment. The clear, personally important and relevant, ability-framed items in the PROMIS Physical Function item bank perform well in PRO assessment. They will benefit from further study and application in a wider variety of rheumatic diseases in diverse clinical groups, including those at the extremes of physical functioning, and in different administration modes. PMID:20015354

Better assessment of physical function: item improvement is neglected but essential.

PubMed

Bruce, Bonnie; Fries, James F; Ambrosini, Debbie; Lingala, Bharathi; Gandek, Barbara; Rose, Matthias; Ware, John E

2009-01-01

Physical function is a key component of patient-reported outcome (PRO) assessment in rheumatology. Modern psychometric methods, such as Item Response Theory (IRT) and Computerized Adaptive Testing, can materially improve measurement precision at the item level. We present the qualitative and quantitative item-evaluation process for developing the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank. The process was stepwise: we searched extensively to identify extant Physical Function items and then classified and selectively reduced the item pool. We evaluated retained items for content, clarity, relevance and comprehension, reading level, and translation ease by experts and patient surveys, focus groups, and cognitive interviews. We then assessed items by using classic test theory and IRT, used confirmatory factor analyses to estimate item parameters, and graded response modeling for parameter estimation. We retained the 20 Legacy (original) Health Assessment Questionnaire Disability Index (HAQ-DI) and the 10 SF-36's PF-10 items for comparison. Subjects were from rheumatoid arthritis, osteoarthritis, and healthy aging cohorts (n = 1,100) and a national Internet sample of 21,133 subjects. We identified 1,860 items. After qualitative and quantitative evaluation, 124 newly developed PROMIS items composed the PROMIS item bank, which included revised Legacy items with good fit that met IRT model assumptions. Results showed that the clearest and best-understood items were simple, in the present tense, and straightforward. Basic tasks (like dressing) were more relevant and important versus complex ones (like dancing). Revised HAQ-DI and PF-10 items with five response options had higher item-information content than did comparable original Legacy items with fewer response options. IRT analyses showed that the Physical Function domain satisfied general criteria for unidimensionality with one-, two-, three-, and four-factor models having comparable model fits. Correlations between factors in the test data sets were > 0.90. Item improvement must underlie attempts to improve outcome assessment. The clear, personally important and relevant, ability-framed items in the PROMIS Physical Function item bank perform well in PRO assessment. They will benefit from further study and application in a wider variety of rheumatic diseases in diverse clinical groups, including those at the extremes of physical functioning, and in different administration modes.

Postprandial metabolite profiles reveal differential nutrient handling after bariatric surgery compared with matched caloric restriction.

PubMed

Khoo, Chin Meng; Muehlbauer, Michael J; Stevens, Robert D; Pamuklar, Zehra; Chen, Jiegen; Newgard, Christopher B; Torquati, Alfonso

2014-04-01

Roux-en-Y gastric bypass (RYGB) surgery results in exaggerated postprandial insulin and incretin responses and increased susceptibility to hypoglycemia. We examined whether these features are due to caloric restriction (CR) or altered nutrient handling. We performed comprehensive analysis of postprandial metabolite responses during a 2-hour mixed-meal tolerance (MMT) test in 20 morbidly obese subjects with type 2 diabetes who underwent RYGB surgery or matched CR. Acylcarnitines and amino acids (AAs) were measured using targeted mass spectrometry. A linear mixed model was used to determine the main effect of interventions and interaction term to assess the effect of interventions on postprandial kinetics. Two weeks after these interventions, several gut hormones (insulin, glucose-dependent insulinotropic polypeptide, and glucagon-like peptide 1), glucose, and multiple AAs, including branched-chain and aromatic species, exhibited a more rapid rate of appearance and clearance in RYGB surgery subjects than in CR subjects during the MMT test. In the RYGB surgery group, changes in leucine/isoleucine, methionine, phenylalanine, and glucagon-like peptide 1 response were associated with changes in insulin response. Levels of alanine, pyruvate, and lactate decreased significantly at the later stages of meal challenge in RYGB surgery subjects but increased with CR. RYGB surgery results in improved metabolic flexibility (ie, greater disposal of glucose and AAs and more complete β-oxidation of fatty acids) compared with CR. The changes in the AA kinetics may augment the hormonal responses seen after RYGB surgery. The reduction in key gluconeogenic substrates in the postprandial state may contribute to increased susceptibility to hypoglycemic symptoms in RYGB surgery subjects.

A Graphical Approach to Item Analysis. Research Report. ETS RR-04-10

ERIC Educational Resources Information Center

Livingston, Samuel A.; Dorans, Neil J.

2004-01-01

This paper describes an approach to item analysis that is based on the estimation of a set of response curves for each item. The response curves show, at a glance, the difficulty and the discriminating power of the item and the popularity of each distractor, at any level of the criterion variable (e.g., total score). The curves are estimated by…

Development and Standardization of the Diagnostic Adaptive Behavior Scale: Application of Item Response Theory to the Assessment of Adaptive Behavior

ERIC Educational Resources Information Center

Tassé, Marc J.; Schalock, Robert L.; Thissen, David; Balboni, Giulia; Bersani, Henry, Jr.; Borthwick-Duffy, Sharon A.; Spreat, Scott; Widaman, Keith F.; Zhang, Dalun; Navas, Patricia

2016-01-01

The Diagnostic Adaptive Behavior Scale (DABS) was developed using item response theory (IRT) methods and was constructed to provide the most precise and valid adaptive behavior information at or near the cutoff point of making a decision regarding a diagnosis of intellectual disability. The DABS initial item pool consisted of 260 items. Using IRT…

The Relationship of Item-Level Response Times with Test-Taker and Item Variables in an Operational CAT Environment. LSAC Research Report Series.

ERIC Educational Resources Information Center

Swygert, Kimberly A.

In this study, data from an operational computerized adaptive test (CAT) were examined in order to gather information concerning item response times in a CAT environment. The CAT under study included multiple-choice items measuring verbal, quantitative, and analytical reasoning. The analyses included the fitting of regression models describing the…

Item response theory in personality assessment: a demonstration using the MMPI-2 depression scale.

PubMed

Childs, R A; Dahlstrom, W G; Kemp, S M; Panter, A T

2000-03-01

Item response theory (IRT) analyses have, over the past 3 decades, added much to our understanding of the relationships among and characteristics of test items, as revealed in examinees response patterns. Assessment instruments used outside the educational context have only infrequently been analyzed using IRT, however. This study demonstrates the relevance of IRT to personality data through analyses of Scale 2 (the Depression Scale) on the revised Minnesota Multiphasic Personality Inventory (MMPI-2). A rich set of hypotheses regarding the items on this scale, including contrasts among the Harris-Lingoes and Wiener-Harmon subscales and differences in the items measurement characteristics for men and women, are investigated through the IRT analyses.

Outcome of Patients Treated With a Single-Fraction Dose of Palliative Radiation for Cutaneous T-Cell Lymphoma

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

Thomas, Tarita O.; Agrawal, Priya; Guitart, Joan

2013-03-01

Purpose: Cutaneous T-cell lymphoma (CTCL) is a radiosensitive tumor. Presently, treatment with radiation is given in multiple fractions. The current literature lacks data that support single-fraction treatment for CTCL. This retrospective review assesses the clinical response in patients treated with a single fraction of radiation. Methods and Materials: This study reviewed the records of 58 patients with CTCL, primarily mycosis fungoides, treated with a single fraction of palliative radiation therapy (RT) between October 1991 and January 2011. Patient and tumor characteristics were reviewed. Response rates were compared using Fisher's exact test and multiple logistic regressions. Survival rates were determined usingmore » the Kaplan-Meier method. Cost-effectiveness analysis was performed to assess the cost of a single vs a multifractionated treatment regimen. Results: Two hundred seventy individual lesions were treated, with the majority (97%) treated with ≥700 cGy; mean follow-up was 41.3 months (range, 3-180 months). Response rate by lesion was assessed, with a complete response (CR) in 255 (94.4%) lesions, a partial response in 10 (3.7%) lesions, a partial response converted to a CR after a second treatment in 4 (1.5%) lesions, and no response in 1 (0.4%) lesion. The CR in lower extremity lesions was lower than in other sites (P=.0016). Lesions treated with photons had lower CR than those treated with electrons (P=.017). Patients with lesions exhibiting large cell transformation and tumor morphology had lower CR (P=.04 and P=.035, respectively). Immunophenotype did not impact response rate (P=.23). Overall survival was significantly lower for patients with Sézary syndrome (P=.0003) and erythroderma (P<.0001). The cost of multifractionated radiation was >200% higher than that for single-fraction radiation. Conclusions: A single fraction of 700 cGy-800 cGy provides excellent palliation for CTCL lesions and is cost effective and convenient for the patient.« less

Measuring pain phenomena after spinal cord injury: Development and psychometric properties of the SCI-QOL Pain Interference and Pain Behavior assessment tools.

PubMed

Cohen, Matthew L; Kisala, Pamela A; Dyson-Hudson, Trevor A; Tulsky, David S

2018-05-01

To develop modern patient-reported outcome measures that assess pain interference and pain behavior after spinal cord injury (SCI). Grounded-theory based qualitative item development; large-scale item calibration field-testing; confirmatory factor analyses; graded response model item response theory analyses; statistical linking techniques to transform scores to the Patient Reported Outcome Measurement Information System (PROMIS) metric. Five SCI Model Systems centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. N/A. Spinal Cord Injury - Quality of Life (SCI-QOL) Pain Interference item bank, SCI-QOL Pain Interference short form, and SCI-QOL Pain Behavior scale. Seven hundred fifty-seven individuals with traumatic SCI completed 58 items addressing various aspects of pain. Items were then separated by whether they assessed pain interference or pain behavior, and poorly functioning items were removed. Confirmatory factor analyses confirmed that each set of items was unidimensional, and item response theory analyses were used to estimate slopes and thresholds for the items. Ultimately, 7 items (4 from PROMIS) comprised the Pain Behavior scale and 25 items (18 from PROMIS) comprised the Pain Interference item bank. Ten of these 25 items were selected to form the Pain Interference short form. The SCI-QOL Pain Interference item bank and the SCI-QOL Pain Behavior scale demonstrated robust psychometric properties. The Pain Interference item bank is available as a computer adaptive test or short form for research and clinical applications, and scores are transformed to the PROMIS metric.

Chemokine receptors CXCR2 and CX3CR1 differentially regulate functional responses of bone-marrow endothelial progenitors during atherosclerotic plaque regression.

PubMed

Herlea-Pana, Oana; Yao, Longbiao; Heuser-Baker, Janet; Wang, Qiongxin; Wang, Qilong; Georgescu, Constantin; Zou, Ming-Hui; Barlic-Dicen, Jana

2015-05-01

Atherosclerosis manifests itself as arterial plaques, which lead to heart attacks or stroke. Treatments supporting plaque regression are therefore aggressively pursued. Studies conducted in models in which hypercholesterolaemia is reversible, such as the Reversa mouse model we have employed in the current studies, will be instrumental for the development of such interventions. Using this model, we have shown that advanced atherosclerosis regression occurs when lipid lowering is used in combination with bone-marrow endothelial progenitor cell (EPC) treatment. However, it remains unclear how EPCs home to regressing plaques and how they augment atherosclerosis reversal. Here we identify molecules that support functional responses of EPCs during plaque resolution. Chemokines CXCL1 and CX3CL1 were detected in the vascular wall of atheroregressing Reversa mice, and their cognate receptors CXCR2 and CX3CR1 were observed on adoptively transferred EPCs in circulation. We tested whether CXCL1-CXCR2 and CX3CL1-CX3CR1 axes regulate functional responses of EPCs during plaque reversal. We show that pharmacological inhibition of CXCR2 or CX3CR1, or genetic inactivation of these two chemokine receptors interfered with EPC-mediated advanced atherosclerosis regression. We also demonstrate that CXCR2 directs EPCs to regressing plaques while CX3CR1 controls a paracrine function(s) of these cells. CXCR2 and CX3CR1 differentially regulate EPC functional responses during atheroregression. Our study improves understanding of how chemokines and chemokine receptors regulate plaque resolution, which could determine the effectiveness of interventions reducing complications of atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Chemokine receptors CXCR2 and CX3CR1 differentially regulate functional responses of bone-marrow endothelial progenitors during atherosclerotic plaque regression

PubMed Central

Herlea-Pana, Oana; Yao, Longbiao; Heuser-Baker, Janet; Wang, Qiongxin; Wang, Qilong; Georgescu, Constantin; Zou, Ming-Hui; Barlic-Dicen, Jana

2015-01-01

Aims Atherosclerosis manifests itself as arterial plaques, which lead to heart attacks or stroke. Treatments supporting plaque regression are therefore aggressively pursued. Studies conducted in models in which hypercholesterolaemia is reversible, such as the Reversa mouse model we have employed in the current studies, will be instrumental for the development of such interventions. Using this model, we have shown that advanced atherosclerosis regression occurs when lipid lowering is used in combination with bone-marrow endothelial progenitor cell (EPC) treatment. However, it remains unclear how EPCs home to regressing plaques and how they augment atherosclerosis reversal. Here we identify molecules that support functional responses of EPCs during plaque resolution. Methods and results Chemokines CXCL1 and CX3CL1 were detected in the vascular wall of atheroregressing Reversa mice, and their cognate receptors CXCR2 and CX3CR1 were observed on adoptively transferred EPCs in circulation. We tested whether CXCL1–CXCR2 and CX3CL1–CX3CR1 axes regulate functional responses of EPCs during plaque reversal. We show that pharmacological inhibition of CXCR2 or CX3CR1, or genetic inactivation of these two chemokine receptors interfered with EPC-mediated advanced atherosclerosis regression. We also demonstrate that CXCR2 directs EPCs to regressing plaques while CX3CR1 controls a paracrine function(s) of these cells. Conclusion CXCR2 and CX3CR1 differentially regulate EPC functional responses during atheroregression. Our study improves understanding of how chemokines and chemokine receptors regulate plaque resolution, which could determine the effectiveness of interventions reducing complications of atherosclerosis. PMID:25765938

Response of Cr and Cr-Al coatings on Zircaloy-2 to high temperature steam

NASA Astrophysics Data System (ADS)

Zhong, Weicheng; Mouche, Peter A.; Heuser, Brent J.

2018-01-01

The oxidation behavior of chromium (Cr) and chromium-aluminum (CrAl) coatings with various compositions deposited on Zircaloy-2 to 700 °C high-temperature steam (HTS) exposure has been investigated. CrAl coatings with higher Al compositions demonstrate lower oxidation weight gain. A layer of γ-alumina developed on the CrAl coatings with Al composition over 43 at%, while Al2O3 and Cr2O3 developed on CrAl coatings with Al composition below 33 at%. Oxidation of Zircaloy-2 substrate was inhibited by the 1um coatings to 20 h HTS exposure. Coating constituent elements diffused into the substrate and formed intermetallic phases with the Zircaloy substrate. Thicker layers of intermetallic phases developed on the coatings with higher Al composition. The intermetallic phases included Fe and Ni, indicating the dissolution of second phase particles (SPPs) during HTS exposure.

The arcuate nucleus and NPY contribute to the antitumorigenic effect of calorie restriction

PubMed Central

Minor, Robin K.; López, Miguel; Younts, Caitlin M.; Jones, Bruce; Pearson, Kevin J.; Anson, R. Michael; Diéguez, Carlos; de Cabo, Rafael

2011-01-01

Summary Calorie restriction (CR) is known to have profound effects on tumor incidence. A typical consequence of CR is hunger, and we hypothesized that the neuroendocrine response to CR might in part mediate CR's antitumor effects. We tested CR under appetite suppression using two models: neuropeptide Y (NPY) knockout mice and monosodium glutamate (MSG)-injected mice. While CR was protective in control mice challenged with a two-stage skin carcinogenesis model, papilloma development was neither delayed nor reduced by CR in the MSG-treated and NPY knockout mice. Adiponectin levels were also not increased by CR in the appetite-suppressed mice. We propose that some of CR’s beneficial effects cannot be separated from those imposed on appetite, and that NPY neurons in the arcuate nucleus of the hypothalamus (ARC) are involved in the translation of reduced intake to downstream physiological and functional benefits. PMID:21385308

Neoadjuvant chemotherapy in breast cancer: prediction of pathologic response with PET/CT and dynamic contrast-enhanced MR imaging--prospective assessment.

PubMed

Tateishi, Ukihide; Miyake, Mototaka; Nagaoka, Tomoaki; Terauchi, Takashi; Kubota, Kazunori; Kinoshita, Takayuki; Daisaki, Hiromitsu; Macapinlac, Homer A

2012-04-01

To clarify whether fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging performed after two cycles of neoadjuvant chemotherapy (NAC) can be used to predict pathologic response in breast cancer. Institutional human research committee approval and written informed consent were obtained. Accuracy after two cycles of NAC for predicting pathologic complete response (pCR) was examined in 142 women (mean age, 57 years: range, 43-72 years) with histologically proved breast cancer between December 2005 and February 2009. Quantitative PET/CT and DCE MR imaging were performed at baseline and after two cycles of NAC. Parameters of PET/CT and of blood flow and microvascular permeability at DCE MR were compared with pathologic response. Patients were also evaluated after NAC by using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 based on DCE MR measurements and European Organization for Research and Treatment of Cancer (EORTC) criteria and PET Response Criteria in Solid Tumors (PERCIST) 1.0 based on PET/CT measurements. Multiple logistic regression analyses were performed to examine continuous variables at PET/CT and DCE MR to predict pCR, and diagnostic accuracies were compared with the McNemar test. Significant decrease from baseline of all parameters at PET/CT and DCE MR was observed after NAC. Therapeutic response was obtained in 24 patients (17%) with pCR and 118 (83%) without pCR. Sensitivity, specificity, and accuracy to predict pCR were 45.5%, 85.5%, and 82.4%, respectively, with RECIST and 70.4%, 95.7%, and 90.8%, respectively, with EORTC and PERCIST. Multiple logistic regression revealed three significant independent predictors of pCR: percentage maximum standardized uptake value (%SUV(max)) (odds ratio [OR], 1.22; 95% confidence interval [CI]: 1.11, 1.34; P < .0001), percentage rate constant (%k(ep)) (OR, 1.07; CI: 1.03, 1.12; P = .002), and percentage area under the time-intensity curve over 90 seconds (%AUC(90)) (OR, 1.04; CI: 1.01, 1.07; P = .048). When diagnostic accuracies are compared, PET/CT is superior to DCE MR for the prediction of pCR (%SUV(max) [90.1%] vs %κ(ep) [83.8%] or %AUC(90) [76.8%]; P < .05). The sensitivities of %SUV(max) (66.7%), %k(ep) (51.7%), and %AUC(90) (50.0%) at (18)F-FDG PET/CT and DCE MR after two cycles of NAC are not acceptable, but the specificities (96.4%, 92.0%, and 95.2%, respectively) are high for stratification of pCR cases in breast cancer. © RSNA, 2012.

Reliability and validity of a short form household food security scale in a Caribbean community.

PubMed

Gulliford, Martin C; Mahabir, Deepak; Rocke, Brian

2004-06-16

We evaluated the reliability and validity of the short form household food security scale in a different setting from the one in which it was developed. The scale was interview administered to 531 subjects from 286 households in north central Trinidad in Trinidad and Tobago, West Indies. We evaluated the six items by fitting item response theory models to estimate item thresholds, estimating agreement among respondents in the same households and estimating the slope index of income-related inequality (SII) after adjusting for age, sex and ethnicity. Item-score correlations ranged from 0.52 to 0.79 and Cronbach's alpha was 0.87. Item responses gave within-household correlation coefficients ranging from 0.70 to 0.78. Estimated item thresholds (standard errors) from the Rasch model ranged from -2.027 (0.063) for the 'balanced meal' item to 2.251 (0.116) for the 'hungry' item. The 'balanced meal' item had the lowest threshold in each ethnic group even though there was evidence of differential functioning for this item by ethnicity. Relative thresholds of other items were generally consistent with US data. Estimation of the SII, comparing those at the bottom with those at the top of the income scale, gave relative odds for an affirmative response of 3.77 (95% confidence interval 1.40 to 10.2) for the lowest severity item, and 20.8 (2.67 to 162.5) for highest severity item. Food insecurity was associated with reduced consumption of green vegetables after additionally adjusting for income and education (0.52, 0.28 to 0.96). The household food security scale gives reliable and valid responses in this setting. Differing relative item thresholds compared with US data do not require alteration to the cut-points for classification of 'food insecurity without hunger' or 'food insecurity with hunger'. The data provide further evidence that re-evaluation of the 'balanced meal' item is required.

Physiological responses and tolerance of kenaf (Hibiscus cannabinus L.) exposed to chromium.

PubMed

Ding, Han; Wang, Guodong; Lou, Lili; Lv, Jinyin

2016-11-01

Selection of kenaf species with chromium (Cr) tolerance and exploring the physiological mechanisms involved in Cr tolerance are crucial for application of these species to phyto-remediation. In the present study, a hydroponic experiment was conducted to investigate the variation in two kenaf cultivars, K39-2 and Zhe50-3 under Cr stress. At the same Cr concentration, the tolerance index (TI) of K39-2 was higher than that of Zhe50-3, indicating that K39-2 may be more tolerant to Cr than Zhe50-3. It was also observed that high concentration of chromium was accumulated both in the shoots and the roots of Hibiscus cannabinus L. The leaves of K39-2 accumulated 4760.28mgkg(-1) of dry weight under 1.50mM Cr stress, and the roots accumulated 11,958.33mgkg(-1). Physiological response shows that the antioxidant enzymes' superoxide dismutase (SOD), catalase activity (CAT) and peroxidase (POD) activities increased in the leaves and decreased in roots of the Cr-stressed plants nearly compared to the control. Moreover, the variation of antioxidant enzymes activities indicated Zhe50-3 was more vulnerable than K39-2, and the contents of the non-protein thiol pool (GSH, NPT and PCs) were higher in K39-2 than Zhe50-3 with the increased Cr concentration. Based on the observations above, it can be concluded that the well-coordinated physiological changes confer a greater Cr tolerance to K39-2 than Zhe50-3 under Cr exposure, and Hibiscus cannabinus L. has a great accumulation capacity for chromium. Copyright © 2016 Elsevier Inc. All rights reserved.

Computerized Adaptive Testing with Item Clones. Research Report.

ERIC Educational Resources Information Center

Glas, Cees A. W.; van der Linden, Wim J.

To reduce the cost of item writing and to enhance the flexibility of item presentation, items can be generated by item-cloning techniques. An important consequence of cloning is that it may cause variability on the item parameters. Therefore, a multilevel item response model is presented in which it is assumed that the item parameters of a…

Slower is not always better: Response-time evidence clarifies the limited role of miserly information processing in the Cognitive Reflection Test

PubMed Central

Pitchford, Melanie; Ball, Linden J.; Hunt, Thomas E.; Steel, Richard

2017-01-01

We report a study examining the role of ‘cognitive miserliness’ as a determinant of poor performance on the standard three-item Cognitive Reflection Test (CRT). The cognitive miserliness hypothesis proposes that people often respond incorrectly on CRT items because of an unwillingness to go beyond default, heuristic processing and invest time and effort in analytic, reflective processing. Our analysis (N = 391) focused on people’s response times to CRT items to determine whether predicted associations are evident between miserly thinking and the generation of incorrect, intuitive answers. Evidence indicated only a weak correlation between CRT response times and accuracy. Item-level analyses also failed to demonstrate predicted response-time differences between correct analytic and incorrect intuitive answers for two of the three CRT items. We question whether participants who give incorrect intuitive answers on the CRT can legitimately be termed cognitive misers and whether the three CRT items measure the same general construct. PMID:29099840

Chromium supplementation enhances the metabolic response of steers to lipopolysaccharide (LPS) challenge

USDA-ARS?s Scientific Manuscript database

The effect of chromium (Cr; KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) supplementation on the metabolic response to LPS challenge was examined. Steers (n=20; 235±4 kg body weight (BW)) received a premix that added 0 (Con) or 0.2 mg/kg Cr to the total diet (DM (dry matter) basis) for ...

Estimating the Effect on Grades of Using Multiple-Choice versus Constructive-Response Questions: Data from the Classroom

ERIC Educational Resources Information Center

Hickson, Stephen; Reed, W. Robert; Sander, Nicholas

2012-01-01

This study investigates the degree to which grades based solely on constructed-response (CR) questions differ from grades based solely on multiple-choice (MC) questions. If CR questions are to justify their higher costs, they should produce different grade outcomes than MC questions. We use a data set composed of thousands of observations on…

Development of the Contact Lens User Experience: CLUE Scales

PubMed Central

Wirth, R. J.; Edwards, Michael C.; Henderson, Michael; Henderson, Terri; Olivares, Giovanna; Houts, Carrie R.

2016-01-01

ABSTRACT Purpose The field of optometry has become increasingly interested in patient-reported outcomes, reflecting a common trend occurring across the spectrum of healthcare. This article reviews the development of the Contact Lens User Experience: CLUE system designed to assess patient evaluations of contact lenses. CLUE was built using modern psychometric methods such as factor analysis and item response theory. Methods The qualitative process through which relevant domains were identified is outlined as well as the process of creating initial item banks. Psychometric analyses were conducted on the initial item banks and refinements were made to the domains and items. Following this data-driven refinement phase, a second round of data was collected to further refine the items and obtain final item response theory item parameters estimates. Results Extensive qualitative work identified three key areas patients consider important when describing their experience with contact lenses. Based on item content and psychometric dimensionality assessments, the developing CLUE instruments were ultimately focused around four domains: comfort, vision, handling, and packaging. Item response theory parameters were estimated for the CLUE item banks (377 items), and the resulting scales were found to provide precise and reliable assignment of scores detailing users’ subjective experiences with contact lenses. Conclusions The CLUE family of instruments, as it currently exists, exhibits excellent psychometric properties. PMID:27383257

The influence of item order on intentional response distortion in the assessment of high potentials: assessing pilot applicants.

PubMed

Khorramdel, Lale; Kubinger, Klaus D; Uitz, Alexander

2014-04-01

An experiment was conducted to investigate the effects of item order and questionnaire content on faking good or intentional response distortion. It was hypothesized that intentional response distortion would either increase towards the end of a long questionnaire, as learning effects might make it easier to adjust responses to a faking good schema, or decrease because applicants' will to distort responses is reduced if the questionnaire lasts long enough. Furthermore, it was hypothesized that certain types of questionnaire content are especially vulnerable to response distortion. Eighty-four pre-selected pilot applicants filled out a questionnaire consisting of 516 items including items from the NEO five factor inventory (NEO FFI), NEO personality inventory revised (NEO PI-R) and business-focused inventory of personality (BIP). The positions of the items were varied within the applicant sample to test if responses are affected by item order, and applicants' response behaviour was additionally compared to that of volunteers. Applicants reported significantly higher mean scores than volunteers, and results provide some evidence of decreased faking tendencies towards the end of the questionnaire. Furthermore, it could be demonstrated that lower variances or standard deviations in combination with appropriate (often higher) mean scores can serve as an indicator for faking tendencies in group comparisons, even if effects are not significant. © 2013 International Union of Psychological Science.

Pattern analysis of total item score and item response of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative sample of US adults

PubMed Central

Kawasaki, Yohei; Ide, Kazuki; Akutagawa, Maiko; Yamada, Hiroshi; Yutaka, Ono; Furukawa, Toshiaki A.

2017-01-01

Background Several recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D). To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative study. Methods Data were drawn from the National Survey of Midlife Development in the United States (MIDUS), which comprises four subsamples: (1) a national random digit dialing (RDD) sample, (2) oversamples from five metropolitan areas, (3) siblings of individuals from the RDD sample, and (4) a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model. Results The total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern. Discussion The total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales. PMID:28289560

The e-MSWS-12: improving the multiple sclerosis walking scale using item response theory.

PubMed

Engelhard, Matthew M; Schmidt, Karen M; Engel, Casey E; Brenton, J Nicholas; Patek, Stephen D; Goldman, Myla D

2016-12-01

The Multiple Sclerosis Walking Scale (MSWS-12) is the predominant patient-reported measure of multiple sclerosis (MS) -elated walking ability, yet it had not been analyzed using item response theory (IRT), the emerging standard for patient-reported outcome (PRO) validation. This study aims to reduce MSWS-12 measurement error and facilitate computerized adaptive testing by creating an IRT model of the MSWS-12 and distributing it online. MSWS-12 responses from 284 subjects with MS were collected by mail and used to fit and compare several IRT models. Following model selection and assessment, subpopulations based on age and sex were tested for differential item functioning (DIF). Model comparison favored a one-dimensional graded response model (GRM). This model met fit criteria and explained 87 % of response variance. The performance of each MSWS-12 item was characterized using category response curves (CRCs) and item information. IRT-based MSWS-12 scores correlated with traditional MSWS-12 scores (r = 0.99) and timed 25-foot walk (T25FW) speed (r =  -0.70). Item 2 showed DIF based on age (χ 2  = 19.02, df = 5, p < 0.01), and Item 11 showed DIF based on sex (χ 2  = 13.76, df = 5, p = 0.02). MSWS-12 measurement error depends on walking ability, but could be lowered by improving or replacing items with low information or DIF. The e-MSWS-12 includes IRT-based scoring, error checking, and an estimated T25FW derived from MSWS-12 responses. It is available at https://ms-irt.shinyapps.io/e-MSWS-12 .

JPRS Report, East Europe.

DTIC Science & Technology

1993-01-26

9 Dec 92 p 4 [Article by B. Dicevska: "A Test of the New Efficiency"] [Text] Next year’s volume of exports, when actually the ... living expenses is gradually beginning to affect Czech and Slovak households. New items are being added to the families’ expenses, which earlier...Months Fall 1992 CR SR Do Not Know 10 16 Prices Will Fall 5 4 Economic Developments in the Next 12 Months A stable share of about 40 percent of the

Children's exposure to harmful elements in toys and low-cost jewelry: characterizing risks and developing a comprehensive approach.

PubMed

Guney, Mert; Zagury, Gerald J

2014-04-30

Contamination problem in jewelry and toys and children's exposure possibility have been previously demonstrated. For this study, risk from oral exposure has been characterized for highly contaminated metallic toys and jewelry ((MJ), n=16) considering three scenarios. Total and bioaccessible concentrations of Cd, Cu, Ni, and Pb were high in selected MJ. First scenario (ingestion of parts or pieces) caused unacceptable risk for eight items for Cd, Ni, and/or Pb (hazard index (HI)>1, up to 75, 5.8, and 43, respectively). HI for ingestion of scraped-off material scenario was always <1. Finally, saliva mobilization scenario caused HI>1 in three samples (two for Cd, one for Ni). Risk characterization identified different potentially hazardous items compared to United States, Canadian, and European Union approaches. A comprehensive approach was also developed to deal with complexity and drawbacks caused by various toy/jewelry definitions, test methods, exposure scenarios, and elements considered in different regulatory approaches. It includes bioaccessible limits for eight priority elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Sb). Research is recommended on metals bioaccessibility determination in toys/jewelry, in vitro bioaccessibility test development, estimation of material ingestion rates and frequency, presence of hexavalent Cr and organic Sn, and assessment of prolonged exposure to MJ. Copyright © 2014 Elsevier B.V. All rights reserved.

Fixed or mixed: a comparison of three, four and mixed-option multiple-choice tests in a Fetal Surveillance Education Program

PubMed Central

2013-01-01

Background Despite the widespread use of multiple-choice assessments in medical education assessment, current practice and published advice concerning the number of response options remains equivocal. This article describes an empirical study contrasting the quality of three 60 item multiple-choice test forms within the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Fetal Surveillance Education Program (FSEP). The three forms are described below. Methods The first form featured four response options per item. The second form featured three response options, having removed the least functioning option from each item in the four-option counterpart. The third test form was constructed by retaining the best performing version of each item from the first two test forms. It contained both three and four option items. Results Psychometric and educational factors were taken into account in formulating an approach to test construction for the FSEP. The four-option test performed better than the three-option test overall, but some items were improved by the removal of options. The mixed-option test demonstrated better measurement properties than the fixed-option tests, and has become the preferred test format in the FSEP program. The criteria used were reliability, errors of measurement and fit to the item response model. Conclusions The position taken is that decisions about the number of response options be made at the item level, with plausible options being added to complete each item on both psychometric and educational grounds rather than complying with a uniform policy. The point is to construct the better performing item in providing the best psychometric and educational information. PMID:23453056

Fixed or mixed: a comparison of three, four and mixed-option multiple-choice tests in a Fetal Surveillance Education Program.

PubMed

Zoanetti, Nathan; Beaves, Mark; Griffin, Patrick; Wallace, Euan M

2013-03-04

Despite the widespread use of multiple-choice assessments in medical education assessment, current practice and published advice concerning the number of response options remains equivocal. This article describes an empirical study contrasting the quality of three 60 item multiple-choice test forms within the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Fetal Surveillance Education Program (FSEP). The three forms are described below. The first form featured four response options per item. The second form featured three response options, having removed the least functioning option from each item in the four-option counterpart. The third test form was constructed by retaining the best performing version of each item from the first two test forms. It contained both three and four option items. Psychometric and educational factors were taken into account in formulating an approach to test construction for the FSEP. The four-option test performed better than the three-option test overall, but some items were improved by the removal of options. The mixed-option test demonstrated better measurement properties than the fixed-option tests, and has become the preferred test format in the FSEP program. The criteria used were reliability, errors of measurement and fit to the item response model. The position taken is that decisions about the number of response options be made at the item level, with plausible options being added to complete each item on both psychometric and educational grounds rather than complying with a uniform policy. The point is to construct the better performing item in providing the best psychometric and educational information.

Measuring the quality of life in hypertension according to Item Response Theory

PubMed Central

Borges, José Wicto Pereira; Moreira, Thereza Maria Magalhães; Schmitt, Jeovani; de Andrade, Dalton Francisco; Barbetta, Pedro Alberto; de Souza, Ana Célia Caetano; Lima, Daniele Braz da Silva; Carvalho, Irialda Saboia

2017-01-01

ABSTRACT OBJECTIVE To analyze the Miniquestionário de Qualidade de Vida em Hipertensão Arterial (MINICHAL – Mini-questionnaire of Quality of Life in Hypertension) using the Item Response Theory. METHODS This is an analytical study conducted with 712 persons with hypertension treated in thirteen primary health care units of Fortaleza, State of Ceará, Brazil, in 2015. The steps of the analysis by the Item Response Theory were: evaluation of dimensionality, estimation of parameters of items, and construction of scale. The study of dimensionality was carried out on the polychoric correlation matrix and confirmatory factor analysis. To estimate the item parameters, we used the Gradual Response Model of Samejima. The analyses were conducted using the free software R with the aid of psych and mirt. RESULTS The analysis has allowed the visualization of item parameters and their individual contributions in the measurement of the latent trait, generating more information and allowing the construction of a scale with an interpretative model that demonstrates the evolution of the worsening of the quality of life in five levels. Regarding the item parameters, the items related to the somatic state have had a good performance, as they have presented better power to discriminate individuals with worse quality of life. The items related to mental state have been those which contributed with less psychometric data in the MINICHAL. CONCLUSIONS We conclude that the instrument is suitable for the identification of the worsening of the quality of life in hypertension. The analysis of the MINICHAL using the Item Response Theory has allowed us to identify new sides of this instrument that have not yet been addressed in previous studies. PMID:28492764

Results of a 2011 national questionnaire for investigation of mean glandular dose from mammography in Japan.

PubMed

Asada, Y; Suzuki, S; Minami, K; Shirakawa, S

2014-03-01

Diagnostic reference levels (DRLs) for mammography have yet to be created in Japan. A national questionnaire investigation into radiographic conditions in Japan was carried out for the purpose of creating DRLs. Items investigated included the following: tube voltage; tube current; current-time product; source-image distance; craniocaudal view; automatic exposure control (AEC) settings; name of mammography unit; image receptor system (computed radiography (CR), flat panel detector (FPD), or film/screen (F/S)); and supported or unsupported monitor diagnosis (including monitor resolution). Estimation of the mean glandular dose (MGD) for mammography was performed and compared with previous investigations. The MGD was 1.58(0.48) mGy, which did not significantly differ from a 2007 investigation. In relation to image receptors, although no difference in average MGD values was observed between CR and FPD systems, F/S systems had a significantly decreased value compared to both CR and FPDs. Concerning digital systems (FPDs), the MGD value of the direct conversion system was significantly higher than the indirect conversion system. No significant difference in MGD value was evident concerning type of monitor diagnosis for either the CR or the FPD digital systems; however, hard copies were used more often in CR. No significant difference in the MGD value was found in relation to monitor resolution. This report suggests ways to lower the doses patients undergoing mammography receive in Japan, and serves as reference data for 4.2 cm compressed breast tissue of 50% composition DRLs. Furthermore, our findings suggest that further optimisation of FPD settings can promote a reduction in the MGD value.

Caloric restriction coupled with radiation decreases metastatic burden in triple negative breast cancer.

PubMed

Simone, Brittany A; Dan, Tu; Palagani, Ajay; Jin, Lianjin; Han, Sunny Y; Wright, Christopher; Savage, Jason E; Gitman, Robert; Lim, Meng Kieng; Palazzo, Juan; Mehta, Minesh P; Simone, Nicole L

2016-09-01

Metastatic breast cancer is devastating and triple negative breast cancers (TNBC) have a higher propensity for metastasis. Improved local control upfront in this aggressive cancer could potentially decrease its propensity toward metastasis. We sought to determine if using caloric restriction (CR) as a systemic therapy, combined with radiation therapy (IR) to the primary tumor, may impact metastatic disease. An orthotopic mouse model using a highly metastatic, luciferase-tagged TNBC cell line (4T1), was used to generate palpable tumors. Mice were then treated with CR, IR, and a combination of the two. In vivo imaging was performed for metastatic evaluation. Molecular evaluation of the tumors was performed, generating a mechanistic hypothesis for CR, which was then tested with pertinent pathway inhibition in the model. CR significantly increased the time to developing metastases, decreased the overall number and volume of lung metastases, and increased survival. CR decreased proliferation, increased apoptosis and globally downregulated the IGF-1R signaling pathway. Adding an IGF-1R/INSR inhibitor to local IR in vivo accomplished a decrease in metastases similar to CR plus IR, demonstrating the importance of the IGF-1R signaling pathway, and underscoring it as a possible mechanism for CR. CR decreased metastatic burden and therefore may complement cytotoxic therapies being used in the clinical setting for metastatic disease. Downregulation of the IGF-1R pathway, is in part responsible for this response and modulating IGF-1R directly resulted in similar improved progression-free survival. The novel use of CR has the potential to enhance clinical outcomes for patients with metastatic breast cancer.

Impact of complete response to chemotherapy on overall survival in advanced colorectal cancer: results from Intergroup N9741.

PubMed

Dy, Grace K; Krook, James E; Green, Erin M; Sargent, Daniel J; Delaunoit, Thierry; Morton, Roscoe F; Fuchs, Charles S; Ramanathan, Ramesh K; Williamson, Stephen K; Findlay, Brian P; Pockaj, Barbara A; Sticca, Robert P; Alberts, Steven R; Pitot, Henry C; Goldberg, Richard M

2007-08-10

To evaluate clinical characteristics and survival outcomes among patients with locally advanced or metastatic colorectal cancer who achieve a complete response (CR) to systemic treatment either alone or with multimodality approach. Data were collected retrospectively from CRC patients enrolled onto the phase III trial N9741, a National Cancer Institute-funded and Gastrointestinal Cancer Intergroup-sponsored study coordinated by the North Central Cancer Treatment Group. Patients were randomly assigned to combinations of oxaliplatin, fluorouracil (FU)/leucovorin (LV) and irinotecan. The three treatment arms consist of IFL (irinotecan + FU/LV), FOLFOX4 (oxaliplatin + FU/LV), and IROX (irinotecan + oxaliplatin). Median follow-up was 42.6 months. Sixty-two (4%) of 1,508 patients had a CR to chemotherapy alone, and an additional 32 (2%) had a CR after multimodality treatment. Factors associated with achieving CR with systemic chemotherapy alone included FOLFOX4 treatment, patients with assessable disease, or a single site of metastasis. Continuing protocol treatment beyond two cycles after documentation of CR was not associated with improved survival. The rate of curative intent resection was significantly higher for patients treated with oxaliplatin-containing regimens (P = .02). Median survival was similar between patients with CR after chemotherapy alone (44.3 months) or after multimodality approach (47.4 months; P = .81). FOLFOX4 was more likely to produce a CR than were IFL or IROX. Oxaliplatin regimens were more likely to result in successful surgical resections. Patients who have CR to systemic chemotherapy alone can achieve impressive survival outcomes similar to those seen among patients who attained a CR status after multimodality treatment.

Development and Application of Methods for Estimating Operating Characteristics of Discrete Test Item Responses without Assuming any Mathematical Form.

ERIC Educational Resources Information Center

Samejima, Fumiko

In latent trait theory the latent space, or space of the hypothetical construct, is usually represented by some unidimensional or multi-dimensional continuum of real numbers. Like the latent space, the item response can either be treated as a discrete variable or as a continuous variable. Latent trait theory relates the item response to the latent…

Application of Group-Level Item Response Models in the Evaluation of Consumer Reports about Health Plan Quality

ERIC Educational Resources Information Center

Reise, Steven P.; Meijer, Rob R.; Ainsworth, Andrew T.; Morales, Leo S.; Hays, Ron D.

2006-01-01

Group-level parametric and non-parametric item response theory models were applied to the Consumer Assessment of Healthcare Providers and Systems (CAHPS[R]) 2.0 core items in a sample of 35,572 Medicaid recipients nested within 131 health plans. Results indicated that CAHPS responses are dominated by within health plan variation, and only weakly…

Bifactor and Item Response Theory Analyses of Interviewer Report Scales of Cognitive Impairment in Schizophrenia

PubMed Central

Reise, Steven P.; Ventura, Joseph; Keefe, Richard S. E.; Baade, Lyle E.; Gold, James M.; Green, Michael F.; Kern, Robert S.; Mesholam-Gately, Raquelle; Nuechterlein, Keith H.; Seidman, Larry J.; Bilder, Robert

2011-01-01

We conducted psychometric analyses of two interview-based measures of cognitive deficits: the 21-item Clinical Global Impression of Cognition in Schizophrenia (CGI-CogS; Ventura et al., 2008), and the 20-item Schizophrenia Cognition Rating Scale (SCoRS; Keefe et al., 2006), which were administered on two occasions to a sample of people with schizophrenia. Traditional psychometrics, bifactor analysis, and item response theory (IRT) methods were used to explore item functioning, dimensionality, and to compare instruments. Despite containing similar item content, responses to the CGI-CogS demonstrated superior psychometric properties (e.g., higher item-intercorrelations, better spread of ratings across response categories), relative to the SCoRS. We argue that these differences arise mainly from the differential use of prompts and how the items are phrased and scored. Bifactor analysis demonstrated that although both measures capture a broad range of cognitive functioning (e.g., working memory, social cognition), the common variance on each is overwhelmingly explained by a single general factor. IRT analyses of the combined pool of 41 items showed that measurement precision is peaked in the mild to moderate range of cognitive impairment. Finally, simulated adaptive testing revealed that only about 10 to 12 items are necessary to achieve latent trait level estimates with reasonably small standard errors for most individuals. This suggests that these interview-based measures of cognitive deficits could be shortened without loss of measurement precision. PMID:21381848

Validation of a clinical critical thinking skills test in nursing.

PubMed

Shin, Sujin; Jung, Dukyoo; Kim, Sungeun

2015-01-27

The purpose of this study was to develop a revised version of the clinical critical thinking skills test (CCTS) and to subsequently validate its performance. This study is a secondary analysis of the CCTS. Data were obtained from a convenience sample of 284 college students in June 2011. Thirty items were analyzed using item response theory and test reliability was assessed. Test-retest reliability was measured using the results of 20 nursing college and graduate school students in July 2013. The content validity of the revised items was analyzed by calculating the degree of agreement between instrument developer intention in item development and the judgments of six experts. To analyze response process validity, qualitative data related to the response processes of nine nursing college students obtained through cognitive interviews were analyzed. Out of initial 30 items, 11 items were excluded after the analysis of difficulty and discrimination parameter. When the 19 items of the revised version of the CCTS were analyzed, levels of item difficulty were found to be relatively low and levels of discrimination were found to be appropriate or high. The degree of agreement between item developer intention and expert judgments equaled or exceeded 50%. From above results, evidence of the response process validity was demonstrated, indicating that subjects respondeds as intended by the test developer. The revised 19-item CCTS was found to have sufficient reliability and validity and will therefore represents a more convenient measurement of critical thinking ability.

Validation of a clinical critical thinking skills test in nursing

PubMed Central

2015-01-01

Purpose: The purpose of this study was to develop a revised version of the clinical critical thinking skills test (CCTS) and to subsequently validate its performance. Methods: This study is a secondary analysis of the CCTS. Data were obtained from a convenience sample of 284 college students in June 2011. Thirty items were analyzed using item response theory and test reliability was assessed. Test-retest reliability was measured using the results of 20 nursing college and graduate school students in July 2013. The content validity of the revised items was analyzed by calculating the degree of agreement between instrument developer intention in item development and the judgments of six experts. To analyze response process validity, qualitative data related to the response processes of nine nursing college students obtained through cognitive interviews were analyzed. Results: Out of initial 30 items, 11 items were excluded after the analysis of difficulty and discrimination parameter. When the 19 items of the revised version of the CCTS were analyzed, levels of item difficulty were found to be relatively low and levels of discrimination were found to be appropriate or high. The degree of agreement between item developer intention and expert judgments equaled or exceeded 50%. Conclusion: From above results, evidence of the response process validity was demonstrated, indicating that subjects respondeds as intended by the test developer. The revised 19-item CCTS was found to have sufficient reliability and validity and will therefore represents a more convenient measurement of critical thinking ability. PMID:25622716

Contact resonance atomic force microscopy imaging in air and water using photothermal excitation.

PubMed

Kocun, Marta; Labuda, Aleksander; Gannepalli, Anil; Proksch, Roger

2015-08-01

Contact Resonance Force Microscopy (CR-FM) is a leading atomic force microscopy technique for measuring viscoelastic nano-mechanical properties. Conventional piezo-excited CR-FM measurements have been limited to imaging in air, since the "forest of peaks" frequency response associated with acoustic excitation methods effectively masks the true cantilever resonance. Using photothermal excitation results in clean contact, resonance spectra that closely match the ideal frequency response of the cantilever, allowing unambiguous and simple resonance frequency and quality factor measurements in air and liquids alike. This extends the capabilities of CR-FM to biologically relevant and other soft samples in liquid environments. We demonstrate CR-FM in air and water on both stiff silicon/titanium samples and softer polystyrene-polyethylene-polypropylene polymer samples with the quantitative moduli having very good agreement between expected and measured values.

The Effects of Airway Microbiome on Corticosteroid Responsiveness in Asthma

PubMed Central

Goleva, Elena; Jackson, Leisa P.; Harris, J. Kirk; Robertson, Charles E.; Sutherland, E. Rand; Hall, Clifton F.; Good, James T.; Gelfand, Erwin W.; Martin, Richard J.

2013-01-01

Rationale: The role of airway microbiome in corticosteroid response in asthma is unknown. Objectives: To examine airway microbiome composition in patients with corticosteroid-resistant (CR) asthma and compare it with patients with corticosteroid-sensitive (CS) asthma and normal control subjects and explore whether bacteria in the airways of subjects with asthma may direct alterations in cellular responses to corticosteroids. Methods: 16S rRNA gene sequencing was performed on bronchoalveolar lavage (BAL) samples of 39 subjects with asthma and 12 healthy control subjects. In subjects with asthma, corticosteroid responsiveness was characterized, BAL macrophages were stimulated with pathogenic versus commensal microorganisms, and analyzed by real-time polymerase chain reaction for the expression of corticosteroid-regulated genes and cellular p38 mitogen-activated protein kinase (MAPK) activation. Measurements and Main Results: Of the 39 subjects with asthma, 29 were CR and 10 were CS. BAL microbiome from subjects with CR and CS asthma did not differ in richness, evenness, diversity, and community composition at the phylum level, but did differ at the genus level, with distinct genus expansions in 14 subjects with CR asthma. Preincubation of asthmatic airway macrophages with Haemophilus parainfluenzae, a uniquely expanded potential pathogen found only in CR asthma airways, resulted in p38 MAPK activation, increased IL-8 (P < 0.01), mitogen-activated kinase phosphatase 1 mRNA (P < 0.01) expression, and inhibition of corticosteroid responses (P < 0.05). This was not observed after exposure to commensal bacterium Prevotella melaninogenica. Inhibition of transforming growth factor-β–associated kinase-1 (TAK1), upstream activator of MAPK, but not p38 MAPK restored cellular sensitivity to corticosteroids. Conclusions: A subset of subjects with CR asthma demonstrates airway expansion of specific gram-negative bacteria, which trigger TAK1/MAPK activation and induce corticosteroid resistance. TAK1 inhibition restored cellular sensitivity to corticosteroids. PMID:24024497

Ligand-field helical luminescence in a 2D ferromagnetic insulator

DOE PAGES

Seyler, Kyle L.; Zhong, Ding; Klein, Dahlia R.; ...

2017-12-04

Bulk chromium tri-iodide (CrI 3) has long been known as a layered van der Waals ferromagnet. However, its monolayer form was only recently isolated and confirmed to be a truly two-dimensional (2D) ferromagnet, providing a new platform for investigating light–matter interactions and magneto-optical phenomena in the atomically thin limit. Here in this paper, we report spontaneous circularly polarized photoluminescence in monolayer CrI 3 under linearly polarized excitation, with helicity determined by the monolayer magnetization direction. In contrast, the bilayer CrI 3 photoluminescence exhibits vanishing circular polarization, supporting the recently uncovered anomalous antiferromagnetic interlayer coupling in CrI 3 bilayers. Distinct frommore » the Wannier–Mott excitons that dominate the optical response in well-known 2D van der Waals semiconductors, our absorption and layer-dependent photoluminescence measurements reveal the importance of ligand-field and charge-transfer transitions to the optoelectronic response of atomically thin CrI 3. We attribute the photoluminescence to a parity-forbidden d–d transition characteristic of Cr 3+ complexes, which displays broad linewidth due to strong vibronic coupling and thickness-independent peak energy due to its localized molecular orbital nature.« less

The predictive value of baseline NAA/Cr for treatment response of first-episode schizophrenia: A ¹H MRS study.

PubMed

Liu, Weibo; Yu, Hualiang; Jiang, Biao; Pan, Bing; Yu, Shaohua; Li, Huichun; Zheng, Leilei

2015-07-23

The study focused on the predictive value of baseline metabolite ratios in bilateral hippocampus of first-episode schizophrenia by using proton magnetic resonance spectroscopy ((1)H MRS). (1)H MRS data were acquired from 23 hallucination and 17 non-hallucination first-episode schizophrenia patients compared with 17 healthy participants. Clinical characteristics of patients were rated using the Positive and Negative Syndrome Scale (PANSS) before and after 3-month treatment. The schizophrenia patients showed lower NAA/Cr ratio than healthy participants respectively (p=0.024; p=0.001), and non-hallucination patients had even lower NAA/Cr ratio than hallucination patients (p=0.033). After 3-month treatment, hallucination patients had greater improvement in negative symptoms than non-hallucination patients (p=0.018). The reduction of PANSS total score and negative factor score was positively correlated with the left NAA/Cr in both group patients (p<0.05). Given that the bilateral hippocampal baseline NAA/Cr had predictive value for the whole treatment response, and the left hippocampal NAA/Cr can predict the prognosis of negative symptoms during acute phase medication in first-episode schizophrenia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Ratiometric near-infrared chemosensor for trivalent chromium ion based on tricarboyanine in living cells.

PubMed

Li, Chun-Yan; Kong, Xue-Fei; Li, Yong-Fei; Weng, Chao; Tang, Jia-Liang; Liu, Dan; Zhu, Wei-Guo

2014-05-08

A tricarboyanine derivative (IRPP) is applied as a ratiometric near-infrared chemosensor for detecting trivalent chromium ions (Cr(3+)) in living cells. Upon the addition of Cr(3+) to a solution of IRPP, large-scale shifts in the emission spectrum (from 755 nm to 561 nm) are observed. In the newly developed sensing system, these well-resolved emission peaks yield a sensing system that covers a linear range from 1.0×10(-7) to 1.0×10(-5) M with a detection limit of 2.5×10(-8) M. The experimental results show the response behavior of IRPP towards Cr(3+) is pH independent under neutral conditions (6.0-7.5). Most importantly, the fast response time (less than 3 min) and selectivity for Cr(3+) over other common metal ions provide a strong argument for the use of this sensor in real world applications. As a proof of concept, the proposed chemosensor has been used to detect and quantify Cr(3+) in river water samples and to image Cr(3+) in living cells with encouraging results. Copyright © 2014 Elsevier B.V. All rights reserved.

Cross-informant and cross-national equivalence using item-response theory (IRT) linking: A case study using the behavioral assessment for children of African heritage in the United States and Jamaica.

PubMed

Lambert, Michael Canute; Ferguson, Gail M; Rowan, George T

2016-03-01

Cross-national study of adolescents' psychological adjustment requires measures that permit reliable and valid assessment across informants and nations, but such measures are virtually nonexistent. Item-response-theory-based linking is a promising yet underutilized methodological procedure that permits more accurate assessment across informants and nations. To demonstrate this procedure, the Resilience Scale of the Behavioral Assessment for Children of African Heritage (Lambert et al., 2005) was administered to 250 African American and 294 Jamaican nonreferred adolescents and their caregivers. Multiple items without significant differential item functioning emerged, allowing scale linking across informants and nations. Calibrating item parameters via item response theory linking can permit cross-informant cross-national assessment of youth. (c) 2016 APA, all rights reserved).

Biosorption of Cr(VI) by coconut coir: spectroscopic investigation on the reaction mechanism of Cr(VI) with lignocellulosic material.

PubMed

Shen, Ying-Shuian; Wang, Shan-Li; Huang, Shiuh-Tsuen; Tzou, Yu-Min; Huang, Jang-Hung

2010-07-15

In this study, the removal mechanism of Cr(VI) from water by coconut coir (CC) was investigated using X-ray photoelectron spectroscopy (XPS), Cr K-edge X-ray absorption near edge structure (XANES) and FTIR spectroscopy. The results showed that, upon reaction with CC at pH 3, Cr(VI) was reduced to Cr(III), which was either bound to CC or released back into solution. As revealed by the FTIR spectra of CC before and after reacting with Cr(VI), the phenolic methoxyl and hydroxyl groups of lignin in CC are the dominant drivers of Cr(VI) reduction, giving rise to carbonyl and carboxyl groups on CC. These functional groups can subsequently provide binding sites for Cr(III) resulting from Cr(VI) reduction. In conjunction with forming complexes with carbonyl and carboxyl groups, the formation of Cr(III) hydroxide precipitate could also readily occur as revealed by the linear combination fitting of the Cr K-edge XANES spectrum using a set of reference compounds. The phenolic groups in lignin are responsible for initiating Cr(VI) reduction, so lignocellulosic materials containing a higher amount of phenolic groups are expected to be more effective scavengers for removal of Cr(VI) from the environment. 2010 Elsevier B.V. All rights reserved.

Combining agreement and frequency rating scales to optimize psychometrics in measuring behavioral health functioning.

PubMed

Marfeo, Elizabeth E; Ni, Pengsheng; Chan, Leighton; Rasch, Elizabeth K; Jette, Alan M

2014-07-01

The goal of this article was to investigate optimal functioning of using frequency vs. agreement rating scales in two subdomains of the newly developed Work Disability Functional Assessment Battery: the Mood & Emotions and Behavioral Control scales. A psychometric study comparing rating scale performance embedded in a cross-sectional survey used for developing a new instrument to measure behavioral health functioning among adults applying for disability benefits in the United States was performed. Within the sample of 1,017 respondents, the range of response category endorsement was similar for both frequency and agreement item types for both scales. There were fewer missing values in the frequency items than the agreement items. Both frequency and agreement items showed acceptable reliability. The frequency items demonstrated optimal effectiveness around the mean ± 1-2 standard deviation score range; the agreement items performed better at the extreme score ranges. Findings suggest an optimal response format requires a mix of both agreement-based and frequency-based items. Frequency items perform better in the normal range of responses, capturing specific behaviors, reactions, or situations that may elicit a specific response. Agreement items do better for those whose scores are more extreme and capture subjective content related to general attitudes, behaviors, or feelings of work-related behavioral health functioning. Copyright © 2014 Elsevier Inc. All rights reserved.

Translation, adaptation and validation of the American short form Patient Activation Measure (PAM13) in a Danish version.

PubMed

Maindal, Helle Terkildsen; Sokolowski, Ineta; Vedsted, Peter

2009-06-29

The Patient Activation Measure (PAM) is a measure that assesses patient knowledge, skill, and confidence for self-management. This study validates the Danish translation of the 13-item Patient Activation Measure (PAM13) in a Danish population with dysglycaemia. 358 people with screen-detected dysglycaemia participating in a primary care health education study responded to PAM13. The PAM13 was translated into Danish by a standardised forward-backward translation. Data quality was assessed by mean, median, item response, missing values, floor and ceiling effects, internal consistency (Cronbach's alpha and average inter-item correlation) and item-rest correlations. Scale properties were assessed by Rasch Rating Scale models. The item response was high with a small number of missing values (0.8-4.2%). Floor effect was small (range 0.6-3.6%), but the ceiling effect was above 15% for all items (range 18.6-62.7%). The alpha-coefficient was 0.89 and the average inter-item correlation 0.38. The Danish version formed a unidimensional, probabilistic Guttman-like scale explaining 43.2% of the variance. We did however, find a different item sequence compared to the original scale. A Danish version of PAM13 with acceptable validity and reliability is now available. Further development should focus on single items, response categories in relation to ceiling effects and further validation of reproducibility and responsiveness.

Detection of Differential Item Functioning Using the Lasso Approach

ERIC Educational Resources Information Center

Magis, David; Tuerlinckx, Francis; De Boeck, Paul

2015-01-01

This article proposes a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis, we propose the "LR lasso DIF method": logistic regression (LR) model is formulated for all item responses. The model contains item-specific intercepts,…

Item response theory analysis of Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL) items in adults with arthritis.

PubMed

Mielenz, Thelma J; Callahan, Leigh F; Edwards, Michael C

2016-03-12

Examine the feasibility of performing an item response theory (IRT) analysis on two of the Centers for Disease Control and Prevention health-related quality of life (CDC HRQOL) modules - the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM). Previous principal components analyses confirm that the two scales both assess a mix of mental (CDC-MH) and physical health (CDC-PH). The purpose is to conduct item response theory (IRT) analysis on the CDC-MH and CDC-PH scales separately. 2182 patients with self-reported or physician-diagnosed arthritis completed a cross-sectional survey including HDCM and HDSM items. Besides global health, the other 8 items ask the number of days that some statement was true; we chose to recode the data into 8 categories based on observed clustering. The IRT assumptions were assessed using confirmatory factor analysis and the data could be modeled using an unidimensional IRT model. The graded response model was used for IRT analyses and CDC-MH and CDC-PH scales were analyzed separately in flexMIRT. The IRT parameter estimates for the five-item CDC-PH all appeared reasonable. The three-item CDC-MH did not have reasonable parameter estimates. The CDC-PH scale is amenable to IRT analysis but the existing The CDC-MH scale is not. We suggest either using the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM) as they currently stand or the CDC-PH scale alone if the primary goal is to measure physical health related HRQOL.

A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay

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

Tvermoes, Brooke E., E-mail: brooke.tvermoes@cardn

The objective of this preliminary study was to evaluate the threshold for immune stimulation in mice following local exposure to metal particles and ions representative of normal-functioning cobalt-chromium (CoCr) metal-on-metal (MoM) hip implants. The popliteal lymph node assay (PLNA) was used in this study to assess immune responses in BALB/c mice following treatment with chromium-oxide (Cr{sub 2}O{sub 3}) particles, metal salts (CoCl{sub 2}, CrCl{sub 3} and NiCl{sub 2}), or Cr{sub 2}O{sub 3} particles together with metal salts using single-dose exposures representing approximately 10 days (0.000114 mg), 19 years (0.0800 mg), and 40 years (0.171 mg) of normal implant wear. Themore » immune response elicited following treatment with Cr{sub 2}O{sub 3} particles together with metal salts was also assessed at four additional doses equivalent to approximately 1.5 months (0.0005 mg), 0.6 years (0.0025 mg), 2.3 years (0.01 mg), and 9.3 years (0.04 mg) of normal implant wear. Mice were injected subcutaneously (50 μL) into the right hind foot with the test article, or with the relevant vehicle control. The proliferative response of the draining lymph node cells (LNC) was measured four days after treatment, and stimulation indices (SI) were derived relative to vehicle controls. The PLNA was negative (SI < 3) for all Cr{sub 2}O{sub 3} particle doses, and was also negative at the lowest dose of the metal salt mixture, and the lowest four doses of the Cr{sub 2}O{sub 3} particles with metal salt mixture. The PLNA was positive (SI > 3) at the highest two doses of the metal salt mixture and the highest three doses of the Cr{sub 2}O{sub 3} particles with the metal salt mixture. The provisional NOAEL and LOAEL values identified in this study for immune activation corresponds to Co and Cr concentrations in the synovial fluid approximately 500 and 2000 times higher than that reported for normal-functioning MoM hip implants, respectively. Overall, these results indicate that normal wear conditions are unlikely to result in immune stimulation in individuals not previously sensitized to metals. - Highlights: • Immune responses in mice were assessed following treatment with Cr2O3 particles with metal salts. • The PLNA was negative (SI < 3) for all Cr2O3 particle doses. • A LOAEL for immune activation was identified at 0.04 mg of metal particles with metal salts. • A NOAEL for immune activation was identified at 0.01 mg of metal particles with metal salts.« less

Effects of supplemental chromium on antibody responses of newly weaned feedlot calves to immunization with infectious bovine rhinotracheitis and parainfluenza 3 virus.

PubMed Central

Burton, J L; Mallard, B A; Mowat, D N

1994-01-01

The objective of this study was to determine the effect of supplemental dietary chromium (Cr) on antibody responses of feedlot calves. Fifty-five newly weaned calves were divided into two groups, 28 that received supplemental Cr and 27 that did not, and were immunized with a commercial vaccine against bovine infectious rhinotracheitis virus (IBR) and bovine parainfluenza virus type 3(PI-3). Sera harvested from blood sampled preimmunization, and at days 14 and 28 postimmunization (PI), were assayed for anti-IBR and anti-PI-3 antibody titers. Individual calves were also scored as seroconverters if day 14 or 28 PI titers were > or = 3 times the value of the preimmunization titer. Thirty-five calves did not seroconvert to either antigen. Of 20 IBR seroconverters, 15 calves were from the Cr-supplemented group while only five calves were controls (p = 0.007). There was no treatment difference in the number of PI-3 seroconverters. Least squares analysis of actual antibody titers revealed that Cr supplementation increased the magnitude of the peak antibody response to the IBR (p = 0.003), but had no effect on anti-PI-3 antibody titers. These data confirmed and extended our previous observations that supplemental Cr can be immunomodulatory in cattle. PMID:8004541

Sequential Computerized Mastery Tests--Three Simulation Studies

ERIC Educational Resources Information Center

Wiberg, Marie

2006-01-01

A simulation study of a sequential computerized mastery test is carried out with items modeled with the 3 parameter logistic item response theory model. The examinees' responses are either identically distributed, not identically distributed, or not identically distributed together with estimation errors in the item characteristics. The…

Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

PubMed

Coomans, Frederik; Hofman, Abe; Brinkhuis, Matthieu; van der Maas, Han L J; Maris, Gunter

2016-01-01

We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses.

What can we learn from PISA?: Investigating PISA's approach to scientific literacy

NASA Astrophysics Data System (ADS)

Schwab, Cheryl Jean

This dissertation is an investigation of the relationship between the multidimensional conception of scientific literacy and its assessment. The Programme for International Student Assessment (PISA), developed under the auspices of the Organization for Economic Cooperation and Development (OECD), offers a unique opportunity to evaluate the assessment of scientific literacy. PISA developed a continuum of performance for scientific literacy across three competencies (i.e., process, content, and situation). Foundational to the interpretation of PISA science assessment is PISA's definition of scientific literacy, which I argue incorporates three themes drawn from history: (a) scientific way of thinking, (b) everyday relevance of science, and (c) scientific literacy for all students. Three coordinated studies were conducted to investigate the validity of PISA science assessment and offer insight into the development of items to assess scientific 2 literacy. Multidimensional models of the internal structure of the PISA 2003 science items were found not to reflect the complex character of PISA's definition of scientific literacy. Although the multidimensional models across the three competencies significantly decreased the G2 statistic from the unidimensional model, high correlations between the dimensions suggest that the dimensions are similar. A cognitive analysis of student verbal responses to PISA science items revealed that students were using competencies of scientific literacy, but the competencies were not elicited by the PISA science items at the depth required by PISA's definition of scientific literacy. Although student responses contained only knowledge of scientific facts and simple scientific concepts, students were using more complex skills to interpret and communicate their responses. Finally the investigation of different scoring approaches and item response models illustrated different ways to interpret student responses to assessment items. These analyses highlighted the complexities of students' responses to the PISA science items and the use of the ordered partition model to accommodate different but equal item responses. The results of the three investigations are used to discuss ways to improve the development and interpretation of PISA's science items.

Diffusion-weighted imaging: Apparent diffusion coefficient histogram analysis for detecting pathologic complete response to chemoradiotherapy in locally advanced rectal cancer.

PubMed

Choi, Moon Hyung; Oh, Soon Nam; Rha, Sung Eun; Choi, Joon-Il; Lee, Sung Hak; Jang, Hong Seok; Kim, Jun-Gi; Grimm, Robert; Son, Yohan

2016-07-01

To investigate the usefulness of apparent diffusion coefficient (ADC) values derived from histogram analysis of the whole rectal cancer as a quantitative parameter to evaluate pathologic complete response (pCR) on preoperative magnetic resonance imaging (MRI). We enrolled a total of 86 consecutive patients who had undergone surgery for rectal cancer after neoadjuvant chemoradiotherapy (CRT) at our institution between July 2012 and November 2014. Two radiologists who were blinded to the final pathological results reviewed post-CRT MRI to evaluate tumor stage. Quantitative image analysis was performed using T2 -weighted and diffusion-weighted images independently by two radiologists using dedicated software that performed histogram analysis to assess the distribution of ADC in the whole tumor. After surgery, 16 patients were confirmed to have achieved pCR (18.6%). All parameters from pre- and post-CRT ADC histogram showed good or excellent agreement between two readers. The minimum, 10th, 25th, 50th, and 75th percentile and mean ADC from post-CRT ADC histogram were significantly higher in the pCR group than in the non-pCR group for both readers. The 25th percentile value from ADC histogram in post-CRT MRI had the best diagnostic performance for detecting pCR, with an area under the receiver operating characteristic curve of 0.796. Low percentile values derived from the ADC histogram analysis of rectal cancer on MRI after CRT showed a significant difference between pCR and non-pCR groups, demonstrating the utility of the ADC value as a quantitative and objective marker to evaluate complete pathologic response to preoperative CRT in rectal cancer. J. Magn. Reson. Imaging 2016;44:212-220. © 2015 Wiley Periodicals, Inc.

Characterization of the Metabolic and Physiologic Response from Chromium Supplementation in Subjects with Type 2 Diabetes

PubMed Central

Cefalu, William T; Rood, Jennifer; Pinsonat, Patricia; Qin, Jianhua; Sereda, Olga; Levitan, Lilian; Anderson, Richard; Zhang, Xian H; Martin, Julie M; Martin, Corby; Wang, Zhong Q; Newcomer, Bradley

2014-01-01

OBJECTIVE To provide a comprehensive evaluation of chromium (Cr) supplementation on metabolic parameters in a cohort of Type 2 DM subjects representing a wide phenotype range and to evaluate changes in “responders” and “non-responders”. DESIGN After pre-intervention testing to assess glycemia, insulin sensitivity (assessed by euglycemic clamps), Cr status, body composition, subjects were randomized in a double-blind fashion to placebo or 1,000 μg Cr. A sub-study was performed to evaluate 24 hour energy balance/substrate oxidation and myocellular/intra-hepatic lipid content. RESULTS There was not a consistent effect of chromium supplementation to improve insulin action across all phenotypes. Insulin sensitivity was negatively correlated to soleus and tibialis muscle intramyocellular lipids and intra-hepatic lipid content. Myocellular lipids were significantly lower in subjects randomized to Cr. At pre-intervention, “responders”, defined as insulin sensitivity change from baseline > 10%, had significantly lower insulin sensitivity and higher fasting glucose and A1c when compared to placebo and “non-responders”, i.e. insulin sensitivity change from baseline < 10%. Clinical response was significantly correlated (p < 0.001) to the baseline insulin sensitivity, fasting glucose and A1c. There was no difference in Cr status between “responders”, and “non-responders”. CONCLUSIONS Clinical response to chromium is more likely in insulin resistant subjects who have more elevated fasting glucose and A1c levels. Cr may reduce myocellular lipids and enhance insulin sensitivity in subjects with type 2 DM independent of effects on weight or hepatic glucose production. Thus, modulation of lipid metabolism by Cr in peripheral tissues may represent a novel mechanism of action. PMID:20022616

Modeling low-dose mortality and disease incubation period of inhalational anthrax in the rabbit.

PubMed

Gutting, Bradford W; Marchette, David; Sherwood, Robert; Andrews, George A; Director-Myska, Alison; Channel, Stephen R; Wolfe, Daniel; Berger, Alan E; Mackie, Ryan S; Watson, Brent J; Rukhin, Andrey

2013-07-21

There is a need to advance our ability to conduct credible human risk assessments for inhalational anthrax associated with exposure to a low number of bacteria. Combining animal data with computational models of disease will be central in the low-dose and cross-species extrapolations required in achieving this goal. The objective of the current work was to apply and advance the competing risks (CR) computational model of inhalational anthrax where data was collected from NZW rabbits exposed to aerosols of Ames strain Bacillus anthracis. An initial aim was to parameterize the CR model using high-dose rabbit data and then conduct a low-dose extrapolation. The CR low-dose attack rate was then compared against known low-dose rabbit data as well as the low-dose curve obtained when the entire rabbit dose-response data set was fitted to an exponential dose-response (EDR) model. The CR model predictions demonstrated excellent agreement with actual low-dose rabbit data. We next used a modified CR model (MCR) to examine disease incubation period (the time to reach a fever >40 °C). The MCR model predicted a germination period of 14.5h following exposure to a low spore dose, which was confirmed by monitoring spore germination in the rabbit lung using PCR, and predicted a low-dose disease incubation period in the rabbit between 14.7 and 16.8 days. Overall, the CR and MCR model appeared to describe rabbit inhalational anthrax well. These results are discussed in the context of conducting laboratory studies in other relevant animal models, combining the CR/MCR model with other computation models of inhalational anthrax, and using the resulting information towards extrapolating a low-dose response prediction for man. Published by Elsevier Ltd.

Cetuximab Combined With Induction Oxaliplatin and Capecitabine, Followed by Neoadjuvant Chemoradiation for Locally Advanced Rectal Cancer: SWOG 0713.

PubMed

Leichman, Cynthia Gail; McDonough, Shannon L; Smalley, Stephen R; Billingsley, Kevin G; Lenz, Heinz-Josef; Beldner, Matthew A; Hezel, Aram F; Velasco, Mario R; Guthrie, Katherine A; Blanke, Charles D; Hochster, Howard S

2018-03-01

Neoadjuvant chemoradiation (NCRT) is standard treatment for locally advanced rectal cancer. Pathologic complete response (pCR) has associated with improved survival. In modern phase III trials of NCRT, pCR ranges from 10% to 20%. Cetuximab improves response in KRAS (KRAS proto-oncogene) wild type (wt) metastatic colorectal cancer. S0713 was designed to assess improvement in pCR with additional use of cetuximab with induction chemotherapy and NCRT for locally advanced, KRAS-wt rectal cancer. Patient eligibility: stage II to III biopsy-proven, KRAS-wt rectal adenocarcinoma; no bowel obstruction; adequate hematologic, hepatic and renal function; performance status of 0 to 2. Target enrollment: 80 patients. induction chemotherapy with wCAPOX (weekly capecitabine and oxaliplatin) and cetuximab followed by the same regimen concurrent with radiation (omitting day 15 oxaliplatin). If fewer than 7 pCRs were observed at planned interim analysis after 40 patients received all therapy, the study would close. Eighty eligible patients would provide 90% power given a true pCR rate > 35% at a significance of 0.04. The regimen would lack future interest if pCR probability was ≤ 20%. Between February 2009 and April 2013, 83 patients registered. Four were ineligible and 4 not treated, leaving 75 evaluable for clinical outcomes and toxicity, of whom 65 had surgery. Of 75 patients, 20 had pCR (27%; 95% confidence interval [CI], 17%-38%); 19 (25%) had microscopic cancer; 36 (48%) had minor/no response (including 10 without surgery). Three-year disease-free survival was 73% (95% CI, 63%-83%). Our trial did not meet the pCR target of 35%. Toxicity was generally acceptable. This regimen cannot be recommended outside the clinical trial setting. Copyright © 2017 Elsevier Inc. All rights reserved.

Oxygen Costs of the Incremental Shuttle Walk Test in Cardiac Rehabilitation Participants: An Historical and Contemporary Analysis.

PubMed

Buckley, John P; Cardoso, Fernando M F; Birkett, Stefan T; Sandercock, Gavin R H

2016-12-01

The incremental shuttle walk test (ISWT) is a standardised assessment for cardiac rehabilitation. Three studies have reported oxygen costs (VO 2 )/metabolic equivalents (METs) of the ISWT. In spite of classic representations from these studies graphically showing curvilinear VO 2 responses to incremented walking speeds, linear regression techniques (also used by the American College of Sports Medicine [ACSM]) have been used to estimate VO 2 . The two main aims of this study were to (i) resolve currently reported discrepancies in the ISWT VO 2 -walking speed relationship, and (ii) derive an appropriate VO 2 versus walking speed regression equation. VO 2 was measured continuously during an ISWT in 32 coronary heart disease [cardiac] rehabilitation (CHD-CR) participants and 30 age-matched controls. Both CHD-CR and control group VO 2 responses were curvilinear in nature. For CHD-CR VO 2  = 4.4e 0.23 × walkingspeed (km/h) . The integrated area under the curve (iAUC) VO 2 across nine ISWT stages was greater in the CHD-CR group versus the control group (p < 0.001): CHD-CR = 423 (±86) ml·kg -1 ·min -1 ·km·h -1 ; control = 316 (±52) ml·kg -1 ·min -1 ·km·h -1 . CHD-CR group vs. control VO 2 was up to 30 % greater at higher ISWT stages. The curvilinear nature of VO 2 responses during the ISWT concur with classic studies reported over 100 years. VO 2 estimates for walking using linear regression models (including the ACSM) clearly underestimate values in healthy and CHD-CR participants, and this study provides a resolution to this when the ISWT is used for CHD-CR populations.

Measuring ability to assess claims about treatment effects: a latent trait analysis of items from the ‘Claim Evaluation Tools’ database using Rasch modelling

PubMed Central

Austvoll-Dahlgren, Astrid; Guttersrud, Øystein; Nsangi, Allen; Semakula, Daniel; Oxman, Andrew D

2017-01-01

Background The Claim Evaluation Tools database contains multiple-choice items for measuring people’s ability to apply the key concepts they need to know to be able to assess treatment claims. We assessed items from the database using Rasch analysis to develop an outcome measure to be used in two randomised trials in Uganda. Rasch analysis is a form of psychometric testing relying on Item Response Theory. It is a dynamic way of developing outcome measures that are valid and reliable. Objectives To assess the validity, reliability and responsiveness of 88 items addressing 22 key concepts using Rasch analysis. Participants We administrated four sets of multiple-choice items in English to 1114 people in Uganda and Norway, of which 685 were children and 429 were adults (including 171 health professionals). We scored all items dichotomously. We explored summary and individual fit statistics using the RUMM2030 analysis package. We used SPSS to perform distractor analysis. Results Most items conformed well to the Rasch model, but some items needed revision. Overall, the four item sets had satisfactory reliability. We did not identify significant response dependence between any pairs of items and, overall, the magnitude of multidimensionality in the data was acceptable. The items had a high level of difficulty. Conclusion Most of the items conformed well to the Rasch model’s expectations. Following revision of some items, we concluded that most of the items were suitable for use in an outcome measure for evaluating the ability of children or adults to assess treatment claims. PMID:28550019

Using Rasch Analysis to Evaluate the Reliability and Validity of the Swallowing Quality of Life Questionnaire: An Item Response Theory Approach.

PubMed

Cordier, Reinie; Speyer, Renée; Schindler, Antonio; Michou, Emilia; Heijnen, Bas Joris; Baijens, Laura; Karaduman, Ayşe; Swan, Katina; Clavé, Pere; Joosten, Annette Veronica

2018-02-01

The Swallowing Quality of Life questionnaire (SWAL-QOL) is widely used clinically and in research to evaluate quality of life related to swallowing difficulties. It has been described as a valid and reliable tool, but was developed and tested using classic test theory. This study describes the reliability and validity of the SWAL-QOL using item response theory (IRT; Rasch analysis). SWAL-QOL data were gathered from 507 participants at risk of oropharyngeal dysphagia (OD) across four European countries. OD was confirmed in 75.7% of participants via videofluoroscopy and/or fiberoptic endoscopic evaluation, or a clinical diagnosis based on meeting selected criteria. Patients with esophageal dysphagia were excluded. Data were analysed using Rasch analysis. Item and person reliability was good for all the items combined. However, person reliability was poor for 8 subscales and item reliability was poor for one subscale. Eight subscales exhibited poor person separation and two exhibited poor item separation. Overall item and person fit statistics were acceptable. However, at an individual item fit level results indicated unpredictable item responses for 28 items, and item redundancy for 10 items. The item-person dimensionality map confirmed these findings. Results from the overall Rasch model fit and Principal Component Analysis were suggestive of a second dimension. For all the items combined, none of the item categories were 'category', 'threshold' or 'step' disordered; however, all subscales demonstrated category disordered functioning. Findings suggest an urgent need to further investigate the underlying structure of the SWAL-QOL and its psychometric characteristics using IRT.

Associations among depression severity, painful physical symptoms, and social and occupational functioning impairment in patients with major depressive disorder: a 3-month, prospective, observational study.

PubMed

Harada, Eiji; Satoi, Yoichi; Kuga, Atsushi; Tokuoka, Hirofumi; Kikuchi, Toshiaki; Watanabe, Koichiro; Alev, Levent; Mimura, Masaru

2017-01-01

To investigate associations among depression severity, painful physical symptoms (PPS), and social and occupational functioning impairment in patients with major depressive disorder (MDD) who had achieved complete remission (CR) or partial remission (PR) after acute treatment. This was a 12-week, multicenter, prospective, observational study. Patients with MDD treated with an antidepressant medication for the previous 12 weeks (±3 weeks) who had achieved CR (defined as a 17-item Hamilton Rating Scale for Depression [HAM-D17] score ≤7) or PR (HAM-D17 score ≥8 and ≤18) were enrolled. Depression severity, PPS, and impairment in social and occupational functioning were assessed using the HAM-D17, the Brief Pain Inventory (Short Form) (BPI-SF), and the Social and Occupational Functioning Assessment Scale (SOFAS), respectively, at enrollment (Week 12) and after 12 weeks (Week 24). Overall, 323 Japanese patients with MDD were enrolled (CR n=158, PR n=165) and 288 patients completed the study (CR n=139, PR n=149). HAM-D17 and SOFAS scores were strongly and negatively correlated at enrollment (Week 12; P <0.0001) and Week 24 ( P <0.0001). A weak negative correlation between the BPI-SF and SOFAS was observed at Week 24 ( P =0.0011), but not at enrollment ( P =0.164). Remission status at enrollment (CR or PR) was associated with achieving normal social and occupational functioning (SOFAS score ≥80) at Week 24 in patients who had not achieved normal social and occupational functioning (SOFAS score <80) at enrollment (CR vs PR, OR=0.05 [95% CIs 0.01-0.18], P <0.0001). A greater proportion of patients with CR and no PPS at enrollment achieved SOFAS scores ≥80 at Week 24 than those with CR and PPS. Our results suggest that treating both depressive symptoms and PPS is important for achieving a normal level of functioning on a long-term basis in patients with MDD.

Threats to Validity When Using Open-Ended Items in International Achievement Studies: Coding Responses to the PISA 2012 Problem-Solving Test in Finland

ERIC Educational Resources Information Center

Arffman, Inga

2016-01-01

Open-ended (OE) items are widely used to gather data on student performance in international achievement studies. However, several factors may threaten validity when using such items. This study examined Finnish coders' opinions about threats to validity when coding responses to OE items in the PISA 2012 problem-solving test. A total of 6…

Effect of Item Response Theory (IRT) Model Selection on Testlet-Based Test Equating. Research Report. ETS RR-14-19

ERIC Educational Resources Information Center

Cao, Yi; Lu, Ru; Tao, Wei

2014-01-01

The local item independence assumption underlying traditional item response theory (IRT) models is often not met for tests composed of testlets. There are 3 major approaches to addressing this issue: (a) ignore the violation and use a dichotomous IRT model (e.g., the 2-parameter logistic [2PL] model), (b) combine the interdependent items to form a…

Kernel-Smoothing Estimation of Item Characteristic Functions for Continuous Personality Items: An Empirical Comparison with the Linear and the Continuous-Response Models

ERIC Educational Resources Information Center

Ferrando, Pere J.

2004-01-01

This study used kernel-smoothing procedures to estimate the item characteristic functions (ICFs) of a set of continuous personality items. The nonparametric ICFs were compared with the ICFs estimated (a) by the linear model and (b) by Samejima's continuous-response model. The study was based on a conditioned approach and used an error-in-variables…

Innovative Application of a Multidimensional Item Response Model in Assessing the Influence of Social Desirability on the Pseudo-Relationship between Self-Efficacy and Behavior

ERIC Educational Resources Information Center

Watson, Kathy; Baranowski, Tom; Thompson, Debbe; Jago, Russell; Baranowski, Janice; Klesges, Lisa M.

2006-01-01

This study examined multidimensional item response theory (MIRT) modeling to assess social desirability (SocD) influences on self-reported physical activity self-efficacy (PASE) and fruit and vegetable self-efficacy (FVSE). The observed sample included 473 Houston-area adolescent males (10-14 years). SocD (nine items), PASE (19 items) and FVSE (21…

The Structure of the Narcissistic Personality Inventory With Binary and Rating Scale Items.

PubMed

Boldero, Jennifer M; Bell, Richard C; Davies, Richard C

2015-01-01

Narcissistic Personality Inventory (NPI) items typically have a forced-choice format, comprising a narcissistic and a nonnarcissistic statement. Recently, some have presented the narcissistic statements and asked individuals to either indicate whether they agree or disagree that the statements are self-descriptive (i.e., a binary response format) or to rate the extent to which they agree or disagree that these statements are self-descriptive on a Likert scale (i.e., a rating response format). The current research demonstrates that when NPI items have a binary or a rating response format, the scale has a bifactor structure (i.e., the items load on a general factor and on 6 specific group factors). Indexes of factor strength suggest that the data are unidimensional enough for the NPI's general factor to be considered a measure of a narcissism latent trait. However, the rating item general factor assessed more narcissism components than the binary item one. The positive correlations of the NPI's general factor, assessed when items have a rating response format, were moderate with self-esteem, strong with a measure of narcissistic grandiosity, and weak with 2 measures of narcissistic vulnerability. Together, the results suggest that using a rating format for items enhances the information provided by the NPI.

Peptide vaccine immunotherapy biomarkers and response patterns in pediatric gliomas

PubMed Central

Müller, Sören; Agnihotri, Sameer; Shoger, Karsen E.; Myers, Max I.; Chaparala, Srilakshmi; Villanueva, Clarence R.; Chattopadhyay, Ansuman; Butterfield, Lisa H.; Okada, Hideho; Pollack, Ian F.

2018-01-01

Low-grade gliomas (LGGs) are the most common brain tumor affecting children. We recently reported an early phase clinical trial of a peptide-based vaccine, which elicited consistent antigen-specific T cell responses in pediatric LGG patients. Additionally, we observed radiologic responses of stable disease (SD), partial response (PR), and near-complete/complete response (CR) following therapy. To identify biomarkers of clinical response in peripheral blood, we performed RNA sequencing on PBMC samples collected at multiple time points. Patients who showed CR demonstrated elevated levels of T cell activation markers, accompanied by a cytotoxic T cell response shortly after treatment initiation. At week 34, patients with CR demonstrated both IFN signaling and Poly-IC:LC adjuvant response patterns. Patients with PR demonstrated a unique, late monocyte response signature. Interestingly, HLA-V expression, before or during therapy, and an early monocytic hematopoietic response were strongly associated with SD. Finally, low IDO1 and PD-L1 expression before treatment and early elevated levels of T cell activation markers were associated with prolonged progression-free survival. Overall, our data support the presence of unique peripheral immune patterns in LGG patients associated with different radiographic responses to our peptide vaccine immunotherapy. Future clinical trials, including our ongoing phase II LGG vaccine immunotherapy, should monitor these response patterns. PMID:29618666

Phase II study of neoadjuvant treatment with doxorubicin, docetaxel, and capecitabine (ATX) in locally advanced or inflammatory breast cancer.

PubMed

Manga, Gumersindo Pérez; Shahi, Parham Khosravi; Ureña, Miguel Méndez; Pereira, Rosa Quiben; Plaza, María Isabel Palomero; Peron, Yann Izarzugaza; Val, Ricardo González Del; Carrión, Joaquín Belón; Cañón, Esperanza Pérez; Alfonso, Pilar García

2010-07-01

Pathologic complete response (pCR) after preoperative systemic chemotherapy (PSCh) is associated with better outcome in locally advanced breast cancer (LABC). PSCh included: doxorubicin (A) 50 mg/m(2) i.v. on day 1; docetaxel (T) 30 mg/m(2) i.v. on days 1, 8 and 15; and capecitabine (X) 1,500 mg/m(2)/day p.o. on days 1-14, in a 4-week course repeated for up to four cycles (ATX), followed by surgery. The primary end point of this study was to evaluate the pCR rate. Secondary endpoints included clinical response rate, disease-free survival (DFS), overall survival (OS), and the toxicity profile. A total of 60 patients were included in the analysis. Median age was 49 years, and 63.3% of patients were hormone receptor positive. The median number of cycles of PSCh was four (95% CI: 3-4). Five patients (8.3%) achieved pCR in both breast and nodes, and 16.7% reached pCR only in nodes. The clinical response rate was 77% (27% complete response), but only 18% of the patients underwent conservative surgery. With a median follow-up of 20 months, 3-year DFS and OS were 76 and 90%, respectively. Grade III/IV toxicity included neutropenia (74%), febrile neutropenia (9%), mucositis (12%), and diarrhea (12%). ATX every 28 days for four cycles is associated with a modest activity (low pCR rate) in the neoadjuvant setting of LABC.

Effect of Supplementing Organic Forms of Zinc, Selenium and Chromium on Performance, Anti-Oxidant and Immune Responses in Broiler Chicken Reared in Tropical Summer.

PubMed

Rao, S V Rama; Prakash, B; Raju, M V L N; Panda, A K; Kumari, R K; Reddy, E Pradeep Kumar

2016-08-01

Two experiments were conducted to study the effect of supplementing organic forms of zinc (Zn), selenium (Se) and chromium (Cr) on performance, anti-oxidant activities and immune responses in broiler chickens from 1 to 21 days of age, which were reared in cyclic heat-stressed condition under tropical summer in open-sided poultry house. A total of 200 (experiment I) and 450-day-old (experiment II) broiler male chicks (Cobb 400) were randomly distributed in stainless steel battery brooders (610 mm × 762 mm × 475 mm) at the rate of five birds per pen. A maize-soybean meal-based control diet (CD) containing recommended (Vencobb 400, Broiler Management Guide) concentrations of inorganic trace minerals and other nutrients was prepared. The CD was supplemented individually with organic form of selenium (Se, 0.30 mg/kg), chromium (Cr, 2 mg/kg) and zinc (Zn, 40 mg/kg) in experiment I. In experiment II, two concentrations of each Zn (20 and 40 mg/kg), Se (0.15 and 0.30 mg/kg) and Cr (1 and 2 mg/kg) were supplemented to the basal diet in 2 × 2 × 2 factorial design. A group without supplementing inorganic trace minerals was maintained as control group in both experiments. Each diet was allotted randomly to ten replicates in both experiments and fed ad libitum from 1 to 21 days of age. At 19th day of age, blood samples were collected for estimation of anti-oxidant and immune responses. Supplementation of Se, Cr and Zn increased (P < 0.05) body mass gain (BMG) and feed intake compared to those fed the CD in experiment I. The feed efficiency (FE) in Cr-fed group was higher (P < 0.05) compared to the CD-fed group. Se or Cr supplementation reduced lipid peroxidation (LP) compared to broilers fed the CD. In experiment II, BMG was not affected (P > 0.05) by the interaction between levels of Zn, Se and Cr in broiler diet. The FE improved (P < 0.05) with supplementation of the trace minerals tested at both concentrations except in group fed 40 mg Zn, 0.5 mg Se and 1 mg Cr/kg. Reduction in lipid peroxidation (LP, P < 0.05) and increased (P < 0.05) activity of superoxide dismutase were observed in broiler fed organic Zn, Se and Cr compared to the CD-fed group. The dietary concentrations of Zn, Se and Cr did not influence (P > 0.05) the immune responses (Newcastle disease titre and cell-mediated immune response to phytohaemagglutinin-P) in both the experiments. Based on the results, it is concluded that supplementation of organic form of Se, Cr and Zn (0.30, 2 and 40 mg/kg, respectively) either alone or in combination significantly improved performance and anti-oxidant responses (reduced LP and increased superoxide dismutase) in commercial broiler chicks (21 days of age) reared in cyclic heat stress conditions in open-sided poultry house during summer.

Item Banks for Substance Use from the Patient-Reported Outcomes Measurement Information System (PROMIS®): Severity of Use and Positive Appeal of Use*

PubMed Central

Pilkonis, Paul A.; Yu, Lan; Dodds, Nathan E.; Johnston, Kelly L.; Lawrence, Suzanne; Hilton, Thomas F.; Daley, Dennis C.; Patkar, Ashwin A.; McCarty, Dennis

2015-01-01

Background Two item banks for substance use were developed as part of the Patient-Reported Outcomes Measurement Information System (PROMIS®): severity of substance use and positive appeal of substance use. Methods Qualitative item analysis (including focus groups, cognitive interviewing, expert review, and item revision) reduced an initial pool of more than 5,300 items for substance use to 119 items included in field testing. Items were written in a first-person, past-tense format, with 5 response options reflecting frequency or severity. Both 30-day and 3-month time frames were tested. The calibration sample of 1,336 respondents included 875 individuals from the general population (ascertained through an internet panel) and 461patients from addiction treatment centers participating in the National Drug Abuse Treatment Clinical Trials Network. Results Final banks of 37 and 18 items were calibrated for severity of substance use and positive appeal of substance use, respectively, using the two-parameter graded response model from item response theory (IRT). Initial calibrations were similar for the 30-day and 3-month time frames, and final calibrations used data combined across the time frames, making the items applicable with either interval. Seven-item static short forms were also developed from each item bank. Conclusions Test information curves showed that the PROMIS item banks provided substantial information in a broad range of severity, making them suitable for treatment, observational, and epidemiological research in both clinical and community settings. PMID:26423364

Creatine ingestion augments dietary carbohydrate mediated muscle glycogen supercompensation during the initial 24 h of recovery following prolonged exhaustive exercise in humans.

PubMed

Roberts, Paul A; Fox, John; Peirce, Nicholas; Jones, Simon W; Casey, Anna; Greenhaff, Paul L

2016-08-01

Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here, we aimed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon. Fourteen healthy, male volunteers cycled to exhaustion at 70 % VO2peak. Muscle biopsies were obtained at rest immediately post-exercise and after 1, 3 and 6 days of recovery, during which Cr or placebo supplements (20 g day(-1)) were ingested along with a prescribed high CHO diet (37.5 kcal kg body mass(-1) day(-1), >80 % calories CHO). Oral-glucose tolerance tests (oral-GTT) were performed pre-exercise and after 1, 3 and 6 days of Cr and placebo supplementation. Exercise depleted muscle glycogen content to the same extent in both treatment groups. Creatine supplementation increased muscle total-Cr, free-Cr and phosphocreatine (PCr) content above placebo following 1, 3 and 6 days of supplementation (all P < 0.05). Creatine supplementation also increased muscle glycogen content noticeably above placebo after 1 day of supplementation (P < 0.05), which was sustained thereafter. This study confirmed dietary Cr augments post-exercise muscle glycogen super-compensation, and demonstrates this occurred during the initial 24 h of post-exercise recovery (when muscle total-Cr had increased by <10 %). This marked response ensued without apparent treatment differences in muscle insulin sensitivity (oral-GTT, muscle GLUT4 mRNA), osmotic stress (muscle c-fos and HSP72 mRNA) or muscle cell volume (muscle water content) responses, such that another mechanism must be causative.

Predictive value of PET-CT for pathological response in stages II and III breast cancer patients following neoadjuvant chemotherapy with docetaxel.

PubMed

García García-Esquinas, Marta A; Arrazola García, Juan; García-Sáenz, José A; Furió-Bacete, V; Fuentes Ferrer, Manuel E; Ortega Candil, Aída; Cabrera Martín, María N; Carreras Delgado, José L

2014-01-01

To prospectively study the value of PET-CT with fluorine-18 fluorodeoxyglucose (FDG) to predict neoadjuvant chemotherapy (NAC) response of locoregional disease of stages II and III breast cancer patients. A written informed consent and approval were obtained from the Ethics Committee. PET-CT accuracy in the prediction of pathologic complete response (pCR) after NAC was studied in primary tumors and lymph node metastasis in 43 women (mean age: 50 years: range: 27-71 years) with histologically proven breast cancer between December 2009 and January 2011. PET-CT was performed at baseline and after NAC. SUV(max) percentage changes (ΔSUV(max)) were compared with pathology findings at surgery. Receiver-operator characteristic (ROC) analysis was used to discriminate between locoregional pCR and non-pCR. In patients not achieving pCR, it was investigated if ΔSUV(max) could accurately identify the residual cancer burden (RCB) classes: RCB-I (minimal residual disease (MRD)), RCB-II (moderate RD), and RCB-III (extensive RD). pCR was obtained in 11 patients (25.6%). Residual disease was found in 32 patients (74.4%): 16 (37.2%) RCB-I, 15 (35.6%) RCB-II and 2 (4.7%) RCB-III. Sensitivity, specificity, and accuracy to predict pCR were 90.9%, 90.6%, and 90.7%, respectively. Specificity was 94.1% in the identification of a subset of patients who had either pCR or MRD. Accuracy of ΔSUV(max) in the locoregional disease of stages II and III breast cancer patients after NAC is high for the identification of pCR cases. Its specificity is potentially sufficient to identify a subgroup of patients who could be managed with conservative surgery. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Practical Guide to Conducting an Item Response Theory Analysis

ERIC Educational Resources Information Center

Toland, Michael D.

2014-01-01

Item response theory (IRT) is a psychometric technique used in the development, evaluation, improvement, and scoring of multi-item scales. This pedagogical article provides the necessary information needed to understand how to conduct, interpret, and report results from two commonly used ordered polytomous IRT models (Samejima's graded…

Analyzing Longitudinal Item Response Data via the Pairwise Fitting Method

ERIC Educational Resources Information Center

Fu, Zhi-Hui; Tao, Jian; Shi, Ning-Zhong; Zhang, Ming; Lin, Nan

2011-01-01

Multidimensional item response theory (MIRT) models can be applied to longitudinal educational surveys where a group of individuals are administered different tests over time with some common items. However, computational problems typically arise as the dimension of the latent variables increases. This is especially true when the latent variable…

Item Construction and Psychometric Models Appropriate for Constructed Responses

DTIC Science & Technology

1991-08-01

which involve only one attribute per item. This is especially true when we are dealing with constructed-response items, we have to measure much more...Service University of Ilinois Educacional Testing Service Rosedal Road Capign. IL 61801 Princeton. K3 08541 Princeton. N3 08541 Dr. Charles LeiS Dr

Different Approaches to Covariate Inclusion in the Mixture Rasch Model

ERIC Educational Resources Information Center

Li, Tongyun; Jiao, Hong; Macready, George B.

2016-01-01

The present study investigates different approaches to adding covariates and the impact in fitting mixture item response theory models. Mixture item response theory models serve as an important methodology for tackling several psychometric issues in test development, including the detection of latent differential item functioning. A Monte Carlo…

Classification Consistency and Accuracy for Complex Assessments Using Item Response Theory

ERIC Educational Resources Information Center

Lee, Won-Chan

2010-01-01

In this article, procedures are described for estimating single-administration classification consistency and accuracy indices for complex assessments using item response theory (IRT). This IRT approach was applied to real test data comprising dichotomous and polytomous items. Several different IRT model combinations were considered. Comparisons…

Robust Estimation of Latent Ability in Item Response Models

ERIC Educational Resources Information Center

Schuster, Christof; Yuan, Ke-Hai

2011-01-01

Because of response disturbances such as guessing, cheating, or carelessness, item response models often can only approximate the "true" individual response probabilities. As a consequence, maximum-likelihood estimates of ability will be biased. Typically, the nature and extent to which response disturbances are present is unknown, and, therefore,…

Theoretical and Empirical Comparisons between Two Models for Continuous Item Responses.

ERIC Educational Resources Information Center

Ferrando, Pere J.

2002-01-01

Analyzed the relations between two continuous response models intended for typical response items: the linear congeneric model and Samejima's continuous response model (CRM). Illustrated the relations described using an empirical example and assessed the relations through a simulation study. (SLD)

Enhanced photoelectrochemical and optical performance of ZnO films tuned by Cr doping

NASA Astrophysics Data System (ADS)

Salem, M.; Akir, S.; Massoudi, I.; Litaiem, Y.; Gaidi, M.; Khirouni, K.

2017-04-01

In this paper, pure and Cr-doped nanostructured Zinc oxide thin films were synthesized by simple and low cost co-precipitation and spin-coating method with Cr concentration varying between 0.5 and 5 at.%. Crystalline structure of the prepared films was investigated by X-ray diffraction (XRD) and Raman spectroscopy techniques. XRD analysis indicated that the films were indexed as the hexagonal phase of wurtzite-type structure and demonstrated a decrease in the crystallite size with increasing Cr doping content. Cr doping revealed a significant effect on the optical measurements such as transmission and photoluminescence properties. The optical measurements indicated that Cr doping decreases the optical band gap and it has been shifted from 3.41 eV for pure ZnO film to 3.31 eV for 5 at.% Cr-doped one. The photoelectrochemical (PEC) sensing characteristics of Cr-doped ZnO layers were investigated. Amongst all photo-anodes with different Cr dopant concentration, the 2 at.% Cr incorporated ZnO films exhibited fast response and higher photoconduction sensitivity.

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

PubMed

Rhodes, Matthew G; Jacoby, Larry L

2007-03-01

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

Item Banking. ERIC/AE Digest.

ERIC Educational Resources Information Center

Rudner, Lawrence

This digest discusses the advantages and disadvantages of using item banks, and it provides useful information for those who are considering implementing an item banking project in their school districts. The primary advantage of item banking is in test development. Using an item response theory method, such as the Rasch model, items from multiple…

An item-response theory approach to safety climate measurement: The Liberty Mutual Safety Climate Short Scales.

PubMed

Huang, Yueng-Hsiang; Lee, Jin; Chen, Zhuo; Perry, MacKenna; Cheung, Janelle H; Wang, Mo

2017-06-01

Zohar and Luria's (2005) safety climate (SC) scale, measuring organization- and group- level SC each with 16 items, is widely used in research and practice. To improve the utility of the SC scale, we shortened the original full-length SC scales. Item response theory (IRT) analysis was conducted using a sample of 29,179 frontline workers from various industries. Based on graded response models, we shortened the original scales in two ways: (1) selecting items with above-average discriminating ability (i.e. offering more than 6.25% of the original total scale information), resulting in 8-item organization-level and 11-item group-level SC scales; and (2) selecting the most informative items that together retain at least 30% of original scale information, resulting in 4-item organization-level and 4-item group-level SC scales. All four shortened scales had acceptable reliability (≥0.89) and high correlations (≥0.95) with the original scale scores. The shortened scales will be valuable for academic research and practical survey implementation in improving occupational safety. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Factors that influence search termination decisions in free recall: an examination of response type and confidence.

PubMed

Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

2011-09-01

In three experiments search termination decisions were examined as a function of response type (correct vs. incorrect) and confidence. It was found that the time between the last retrieved item and the decision to terminate search (exit latency) was related to the type of response and confidence in the last item retrieved. Participants were willing to search longer when the last retrieved item was a correct item vs. an incorrect item and when the confidence was high in the last retrieved item. It was also found that the number of errors retrieved during the recall period was related to search termination decisions such that the more errors retrieved, the more likely participants were to terminate the search. Finally, it was found that knowledge of overall search set size influenced the time needed to search for items, but did not influence search termination decisions. Copyright © 2011 Elsevier B.V. All rights reserved.

Item response theory analysis of the life orientation test-revised: age and gender differential item functioning analyses.

PubMed

Steca, Patrizia; Monzani, Dario; Greco, Andrea; Chiesi, Francesca; Primi, Caterina

2015-06-01

This study is aimed at testing the measurement properties of the Life Orientation Test-Revised (LOT-R) for the assessment of dispositional optimism by employing item response theory (IRT) analyses. The LOT-R was administered to a large sample of 2,862 Italian adults. First, confirmatory factor analyses demonstrated the theoretical conceptualization of the construct measured by the LOT-R as a single bipolar dimension. Subsequently, IRT analyses for polytomous, ordered response category data were applied to investigate the items' properties. The equivalence of the items across gender and age was assessed by analyzing differential item functioning. Discrimination and severity parameters indicated that all items were able to distinguish people with different levels of optimism and adequately covered the spectrum of the latent trait. Additionally, the LOT-R appears to be gender invariant and, with minor exceptions, age invariant. Results provided evidence that the LOT-R is a reliable and valid measure of dispositional optimism. © The Author(s) 2014.

Influence of Skip Patterns on Item Non-Response in a Substance Use Survey of 7th to 12th Grade Students

ERIC Educational Resources Information Center

Ding, Kele; Olds, R. Scott; Thombs, Dennis L.

2009-01-01

This retrospective case study assessed the influence of item non-response error on subsequent response to questionnaire items assessing adolescent alcohol and marijuana use. Post-hoc analyses were conducted on survey results obtained from 4,371 7th to 12th grade students in Ohio in 2005. A skip pattern design in a conventional questionnaire…

Using a Multivariate Multilevel Polytomous Item Response Theory Model to Study Parallel Processes of Change: The Dynamic Association between Adolescents' Social Isolation and Engagement with Delinquent Peers in the National Youth Survey

ERIC Educational Resources Information Center

Hsieh, Chueh-An; von Eye, Alexander A.; Maier, Kimberly S.

2010-01-01

The application of multidimensional item response theory models to repeated observations has demonstrated great promise in developmental research. It allows researchers to take into consideration both the characteristics of item response and measurement error in longitudinal trajectory analysis, which improves the reliability and validity of the…

Applying mixed methods to pretest the Pressure Ulcer Quality of Life (PU-QOL) instrument.

PubMed

Gorecki, C; Lamping, D L; Nixon, J; Brown, J M; Cano, S

2012-04-01

Pretesting is key in the development of patient-reported outcome (PRO) instruments. We describe a mixed-methods approach based on interviews and Rasch measurement methods in the pretesting of the Pressure Ulcer Quality of Life (PU-QOL) instrument. We used cognitive interviews to pretest the PU-QOL in 35 patients with pressure ulcers with the view to identifying problematic items, followed by Rasch analysis to examine response options, appropriateness of the item series and biases due to question ordering (item fit). We then compared findings in an interactive and iterative process to identify potential strengths and weaknesses of PU-QOL items, and guide decision-making about further revisions to items and design/layout. Although cognitive interviews largely supported items, they highlighted problems with layout, response options and comprehension. Findings from the Rasch analysis identified problems with response options through reversed thresholds. The use of a mixed-methods approach in pretesting the PU-QOL instrument proved beneficial for identifying problems with scale layout, response options and framing/wording of items. Rasch measurement methods are a useful addition to standard qualitative pretesting for evaluating strengths and weaknesses of early stage PRO instruments.

Differential impact of ionic and coordinate covalent chromium (Cr)-DNA binding on DNA replication.

PubMed

Fornsaglio, Jamie L; O'Brien, Travis J; Patierno, Steven R

2005-11-01

The reactive species produced by the reduction of Cr(VI), particularly Cr(III), can form both ionic and coordinate covalent complexes with DNA. These Cr(III)-DNA interactions consist of Cr-DNA monoadducts, Cr-DNA ternary adducts, and Cr-DNA interstrand cross-links (Cr-ICLs), the latter of which are DNA polymerase arresting lesions (PALs). We sought to determine the impact of Cr-DNA interactions on the formation of replication blocking lesions in S. cerevisiae using a PCR-based method. We found that target sequence (TS) amplification using DNA isolated from Cr(VI)-treated yeast actually increased as a function of Cr(VI) concentration. Moreover, the enhanced TS amplification was reproduced in vitro using Cr(III)-treated DNA. In contrast, PCR amplification of TS from DNA isolated from yeast exposed to equitoxic doses of the inorganic DNA cross-linking agent cisplatin (CDDP), was decreased in a concentration-dependent manner. This paradox suggested that a specific Cr-DNA interaction, such as an ionic Cr-DNA complex, was responsible for the enhanced TS amplification, thereby masking the replication-blocking effect of certain ternary Cr-DNA adducts (i.e. interstrand cross-links). To test this possibility, we removed ionically associated Cr from the DNA using salt extraction prior to PCR analysis. This procedure obviated the increased amplification and revealed a dose-dependent decrease in TS amplification and an increase in Cr-PALs. These data from DNA analyzed ex vivo after treatment of intact cells indicate that ionic interactions of Cr with DNA result in increased DNA amplification whereas coordinate-covalent Cr-DNA complexes lead to formation of Cr-PALs. Thus, these results suggest that treatment of living cells with Cr(VI) leads to two modes of Cr-binding, which may have conflicting effects on DNA replication.

HIV/AIDS knowledge among men who have sex with men: applying the item response theory.

PubMed

Gomes, Raquel Regina de Freitas Magalhães; Batista, José Rodrigues; Ceccato, Maria das Graças Braga; Kerr, Lígia Regina Franco Sansigolo; Guimarães, Mark Drew Crosland

2014-04-01

To evaluate the level of HIV/AIDS knowledge among men who have sex with men in Brazil using the latent trait model estimated by Item Response Theory. Multicenter, cross-sectional study, carried out in ten Brazilian cities between 2008 and 2009. Adult men who have sex with men were recruited (n = 3,746) through Respondent Driven Sampling. HIV/AIDS knowledge was ascertained through ten statements by face-to-face interview and latent scores were obtained through two-parameter logistic modeling (difficulty and discrimination) using Item Response Theory. Differential item functioning was used to examine each item characteristic curve by age and schooling. Overall, the HIV/AIDS knowledge scores using Item Response Theory did not exceed 6.0 (scale 0-10), with mean and median values of 5.0 (SD = 0.9) and 5.3, respectively, with 40.7% of the sample with knowledge levels below the average. Some beliefs still exist in this population regarding the transmission of the virus by insect bites, by using public restrooms, and by sharing utensils during meals. With regard to the difficulty and discrimination parameters, eight items were located below the mean of the scale and were considered very easy, and four items presented very low discrimination parameter (< 0.34). The absence of difficult items contributed to the inaccuracy of the measurement of knowledge among those with median level and above. Item Response Theory analysis, which focuses on the individual properties of each item, allows measures to be obtained that do not vary or depend on the questionnaire, which provides better ascertainment and accuracy of knowledge scores. Valid and reliable scales are essential for monitoring HIV/AIDS knowledge among the men who have sex with men population over time and in different geographic regions, and this psychometric model brings this advantage.

Calibrating Item Families and Summarizing the Results Using Family Expected Response Functions

ERIC Educational Resources Information Center

Sinharay, Sandip; Johnson, Matthew S.; Williamson, David M.

2003-01-01

Item families, which are groups of related items, are becoming increasingly popular in complex educational assessments. For example, in automatic item generation (AIG) systems, a test may consist of multiple items generated from each of a number of item models. Item calibration or scoring for such an assessment requires fitting models that can…

Cr-enriched yeast: beyond fibers for the management of postprandial glycemic response to bread.

PubMed

Yanni, Amalia E; Stamataki, Nikoleta; Stoupaki, Maria; Konstantopoulos, Panagiotis; Pateras, Irene; Tentolouris, Nikolaos; Perrea, Despoina; T Karathanos, Vaios

2017-06-01

Efforts regarding the amelioration of postprandial glycemic response to bread are mainly focused in the addition of soluble dietary fibers. The current study presents another approach which is based on the supplementation of flour with Cr-enriched yeast. Cr is known for its beneficial effects on improvement of glucose tolerance and enhancement of insulin sensitivity. Twelve normoglycemic subjects were provided with white bread (WB, reference food) or whole wheat bread with Cr-enriched yeast (WWCrB, rich in insoluble fibers) or white wheat bread with Cr-enriched yeast (WCrB, poor in fibers) or whole wheat-rye-barley bread enriched with oat beta glucans (BGB, rich in soluble fibers) with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Postprandial glucose, insulin and ghrelin responses as well as glycemic index (GI) were evaluated. Ingestion of WWCrB, WCrB and BGB elicited lower incremental area under the curve (iAUC) for 120-min glycemic response compared to WB (1033.02 ± 282.32, 701.69 ± 330.86 and 748.95 ± 185.42 vs 2070.87 ± 518.44 mg/dL min, respectively, P < 0.05 for WCrB and BGB). The GI was calculated as 62.35 ± 11.78 for WWCrB, 34.22 ± 11.93 for WCrB and 37.90 ± 5.00 for BGB (P < 0.05 vs WB, GI = 100). iAUC for 120-min insulin response to BGB was significantly lower than WB (2780.04 ± 303.26 vs 3915.53 ± 490.57 μU/mL min, P < 0.05), while ghrelin remained suppressed for almost 120 min after the consumption of WWCrB and BGB. Supplementation of flour with Cr-enriched yeast induces milder postprandial glycemic response to bread without the necessity of high fiber amounts, providing with another strategy for the management of glycemic control.

Autologous Bone Marrow-Derived Mesenchymal Stem Cells Modulate Molecular Markers of Inflammation in Dogs with Cruciate Ligament Rupture.

PubMed

Muir, Peter; Hans, Eric C; Racette, Molly; Volstad, Nicola; Sample, Susannah J; Heaton, Caitlin; Holzman, Gerianne; Schaefer, Susan L; Bloom, Debra D; Bleedorn, Jason A; Hao, Zhengling; Amene, Ermias; Suresh, M; Hematti, Peiman

2016-01-01

Mid-substance rupture of the canine cranial cruciate ligament rupture (CR) and associated stifle osteoarthritis (OA) is an important veterinary health problem. CR causes stifle joint instability and contralateral CR often develops. The dog is an important model for human anterior cruciate ligament (ACL) rupture, where rupture of graft repair or the contralateral ACL is also common. This suggests that both genetic and environmental factors may increase ligament rupture risk. We investigated use of bone marrow-derived mesenchymal stem cells (BM-MSCs) to reduce systemic and stifle joint inflammatory responses in dogs with CR. Twelve dogs with unilateral CR and contralateral stable partial CR were enrolled prospectively. BM-MSCs were collected during surgical treatment of the unstable CR stifle and culture-expanded. BM-MSCs were subsequently injected at a dose of 2x106 BM-MSCs/kg intravenously and 5x106 BM-MSCs by intra-articular injection of the partial CR stifle. Blood (entry, 4 and 8 weeks) and stifle synovial fluid (entry and 8 weeks) were obtained after BM-MSC injection. No adverse events after BM-MSC treatment were detected. Circulating CD8+ T lymphocytes were lower after BM-MSC injection. Serum C-reactive protein (CRP) was decreased at 4 weeks and serum CXCL8 was increased at 8 weeks. Synovial CRP in the complete CR stifle was decreased at 8 weeks. Synovial IFNγ was also lower in both stifles after BM-MSC injection. Synovial/serum CRP ratio at diagnosis in the partial CR stifle was significantly correlated with development of a second CR. Systemic and intra-articular injection of autologous BM-MSCs in dogs with partial CR suppresses systemic and stifle joint inflammation, including CRP concentrations. Intra-articular injection of autologous BM-MSCs had profound effects on the correlation and conditional dependencies of cytokines using causal networks. Such treatment effects could ameliorate risk of a second CR by modifying the stifle joint inflammatory response associated with cranial cruciate ligament matrix degeneration or damage.

Autologous Bone Marrow-Derived Mesenchymal Stem Cells Modulate Molecular Markers of Inflammation in Dogs with Cruciate Ligament Rupture

PubMed Central

Muir, Peter; Hans, Eric C.; Racette, Molly; Volstad, Nicola; Sample, Susannah J.; Heaton, Caitlin; Holzman, Gerianne; Schaefer, Susan L.; Bloom, Debra D.; Bleedorn, Jason A.; Hao, Zhengling; Amene, Ermias; Suresh, M.; Hematti, Peiman

2016-01-01

Mid-substance rupture of the canine cranial cruciate ligament rupture (CR) and associated stifle osteoarthritis (OA) is an important veterinary health problem. CR causes stifle joint instability and contralateral CR often develops. The dog is an important model for human anterior cruciate ligament (ACL) rupture, where rupture of graft repair or the contralateral ACL is also common. This suggests that both genetic and environmental factors may increase ligament rupture risk. We investigated use of bone marrow-derived mesenchymal stem cells (BM-MSCs) to reduce systemic and stifle joint inflammatory responses in dogs with CR. Twelve dogs with unilateral CR and contralateral stable partial CR were enrolled prospectively. BM-MSCs were collected during surgical treatment of the unstable CR stifle and culture-expanded. BM-MSCs were subsequently injected at a dose of 2x106 BM-MSCs/kg intravenously and 5x106 BM-MSCs by intra-articular injection of the partial CR stifle. Blood (entry, 4 and 8 weeks) and stifle synovial fluid (entry and 8 weeks) were obtained after BM-MSC injection. No adverse events after BM-MSC treatment were detected. Circulating CD8+ T lymphocytes were lower after BM-MSC injection. Serum C-reactive protein (CRP) was decreased at 4 weeks and serum CXCL8 was increased at 8 weeks. Synovial CRP in the complete CR stifle was decreased at 8 weeks. Synovial IFNγ was also lower in both stifles after BM-MSC injection. Synovial/serum CRP ratio at diagnosis in the partial CR stifle was significantly correlated with development of a second CR. Systemic and intra-articular injection of autologous BM-MSCs in dogs with partial CR suppresses systemic and stifle joint inflammation, including CRP concentrations. Intra-articular injection of autologous BM-MSCs had profound effects on the correlation and conditional dependencies of cytokines using causal networks. Such treatment effects could ameliorate risk of a second CR by modifying the stifle joint inflammatory response associated with cranial cruciate ligament matrix degeneration or damage. PMID:27575050

Using Rasch rating scale model to reassess the psychometric properties of the Persian version of the PedsQL™ 4.0 Generic Core Scales in school children.

PubMed

Jafari, Peyman; Bagheri, Zahra; Ayatollahi, Seyyed Mohamad Taghi; Soltani, Zahra

2012-03-13

Item response theory (IRT) is extensively used to develop adaptive instruments of health-related quality of life (HRQoL). However, each IRT model has its own function to estimate item and category parameters, and hence different results may be found using the same response categories with different IRT models. The present study used the Rasch rating scale model (RSM) to examine and reassess the psychometric properties of the Persian version of the PedsQL™ 4.0 Generic Core Scales. The PedsQL™ 4.0 Generic Core Scales was completed by 938 Iranian school children and their parents. Convergent, discriminant and construct validity of the instrument were assessed by classical test theory (CTT). The RSM was applied to investigate person and item reliability, item statistics and ordering of response categories. The CTT method showed that the scaling success rate for convergent and discriminant validity were 100% in all domains with the exception of physical health in the child self-report. Moreover, confirmatory factor analysis supported a four-factor model similar to its original version. The RSM showed that 22 out of 23 items had acceptable infit and outfit statistics (<1.4, >0.6), person reliabilities were low, item reliabilities were high, and item difficulty ranged from -1.01 to 0.71 and -0.68 to 0.43 for child self-report and parent proxy-report, respectively. Also the RSM showed that successive response categories for all items were not located in the expected order. This study revealed that, in all domains, the five response categories did not perform adequately. It is not known whether this problem is a function of the meaning of the response choices in the Persian language or an artifact of a mostly healthy population that did not use the full range of the response categories. The response categories should be evaluated in further validation studies, especially in large samples of chronically ill patients.

Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology

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

Schneider, Brent C.; Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037; Constant, Stephanie L.

Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory responsemore » in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels. -- Highlights: ► Allergic asthma correlated with exposure to certain inhaled particulate chromates. ► Direct causal association between Cr(VI) and allergic asthma not established. ► Cr exacerbated pathology and airway hyperresponsiveness in an OVA-challenged mouse. ► Particulate Cr(VI) may augment severity and alter phenotype of ongoing allergic asthma.« less

Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions

PubMed Central

Pattar, Guruprasad R.; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S.

2008-01-01

Since trivalent chromium (Cr3+) enhances glucose metabolism, interest in the use of Cr3+as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr3+ may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr3+-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders. PMID:16870493

Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions.

PubMed

Pattar, Guruprasad R; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S

2006-11-07

Since trivalent chromium (Cr(3+)) enhances glucose metabolism, interest in the use of Cr(3+)as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr(3+) may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr(3+)-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders.

Effects of autoshaping procedures on 3H-8-OH-DPAT-labeled 5-HT1a binding and 125I-LSD-labeled 5-HT2a binding in rat brain.

PubMed

Tomie, Arthur; Di Poce, Jason; Aguado, Allison; Janes, Amy; Benjamin, Daniel; Pohorecky, Larissa

2003-06-13

Effects of experience with Pavlovian autoshaping procedures on lever-press autoshaping conditioned response (CR) performance and 3H-8-OH-DPAT-labeled binding of 5-HT(1a) receptors as well as 125I-LSD-labeled binding of 5-HT(2a) receptors were evaluated in four groups of male Long-Evans hooded rats. Two groups of rats (Group Paired High CR and Group Paired Low CR) received Pavlovian autoshaping procedures wherein the presentation of a lever (conditioned stimulus, CS) was followed by the response-independent presentation of food (unconditioned stimulus, US). Rats in Group Paired High CR (n=12) showed more rapid CR acquisition and higher asymptotic levels of lever-press autoshaping CR performance relative to rats in Group Low CR (n=12). Group Omission (n=9) received autoshaping with an omission contingency, such that performing the lever-press autoshaping CR resulted in the cancellation the food US, while Group Random (n=9) received presentations of lever CS and food US randomly with respect to one another. Though Groups Omission and Random did not differ in lever-press autoshaping CR performance, Group Omission showed significantly lower levels of 3H-8-OH-DPAT-labeled 5-HT(1a) binding in post-synaptic areas (frontal cortex, septum, caudate putamen), as well as significantly higher plasma corticosterone levels than Group Random. In addition, Group Random showed higher levels of 3H-8-OH-DPAT-labeled 5-HT(1a) binding in pre-synaptic somatodendritic autoreceptors on dorsal raphe nucleus relative to each of the other three groups. Autoradiographic analysis of 125I-LSD-labeled 5-HT(2a) receptor binding revealed no significant differences between Groups Paired High CR and Paired Low CR or between Groups Omission and Random in any brain regions.

Converging evidence for control of color-word Stroop interference at the item level.

PubMed

Bugg, Julie M; Hutchison, Keith A

2013-04-01

Prior studies have shown that cognitive control is implemented at the list and context levels in the color-word Stroop task. At first blush, the finding that Stroop interference is reduced for mostly incongruent items as compared with mostly congruent items (i.e., the item-specific proportion congruence [ISPC] effect) appears to provide evidence for yet a third level of control, which modulates word reading at the item level. However, evidence to date favors the view that ISPC effects reflect the rapid prediction of high-contingency responses and not item-specific control. In Experiment 1, we first show that an ISPC effect is obtained when the relevant dimension (i.e., color) signals proportion congruency, a problematic pattern for theories based on differential response contingencies. In Experiment 2, we replicate and extend this pattern by showing that item-specific control settings transfer to new stimuli, ruling out alternative frequency-based accounts. In Experiment 3, we revert to the traditional design in which the irrelevant dimension (i.e., word) signals proportion congruency. Evidence for item-specific control, including transfer of the ISPC effect to new stimuli, is apparent when 4-item sets are employed but not when 2-item sets are employed. We attribute this pattern to the absence of high-contingency responses on incongruent trials in the 4-item set. These novel findings provide converging evidence for reactive control of color-word Stroop interference at the item level, reveal theoretically important factors that modulate reliance on item-specific control versus contingency learning, and suggest an update to the item-specific control account (Bugg, Jacoby, & Chanani, 2011).

What makes A. guillouiae SFC 500-1A able to co-metabolize phenol and Cr(VI)? A proteomic approach.

PubMed

Ontañon, Ornella Mailén; Landi, Claudia; Carleo, Alfonso; Gagliardi, Assunta; Bianchi, Laura; González, Paola Solange; Agostini, Elizabeth; Bini, Luca

2018-04-27

Acinetobacter guillouiae SFC 500-1A is an environmental bacterium able to efficiently co-remediate phenol and Cr(VI). To further understand the molecular mechanisms triggered in this strain during the bioremediation process, variations in the proteomic profile after treatment with phenol and phenol plus Cr(VI) were evaluated. The proteomic analysis revealed the induction of the β-ketoadipate pathway for phenol oxidation and the assimilation of degradation products through TCA cycle and glyoxylate shunt. Phenol exposure increased the abundance of proteins associated to energetic processes and ATP synthesis, but it also triggered cellular stress. The lipid bilayer was suggested as a target of phenol toxicity, and changing fatty acids composition seemed to be the bacterial response to protect the membrane integrity. The involvement of two flavoproteins in Cr(VI) reduction to Cr(III) was also proposed. The results suggested the important role of chaperones, antioxidant response and SOS-induced proteins in the ability of the strain to mitigate the damage generated by phenol and Cr(VI). This research contributes to elucidate the mechanisms involved in A. guillouiae SFC 500-1A tolerance and co-remediation of phenol and Cr(VI). Such information may result useful not only to improve its bioremediation efficiency but also to identify putative markers of resistance in environmental bacteria. Copyright © 2018 Elsevier B.V. All rights reserved.

A semi-parametric within-subject mixture approach to the analyses of responses and response times.

PubMed

Molenaar, Dylan; Bolsinova, Maria; Vermunt, Jeroen K

2018-05-01

In item response theory, modelling the item response times in addition to the item responses may improve the detection of possible between- and within-subject differences in the process that resulted in the responses. For instance, if respondents rely on rapid guessing on some items but not on all, the joint distribution of the responses and response times will be a multivariate within-subject mixture distribution. Suitable parametric methods to detect these within-subject differences have been proposed. In these approaches, a distribution needs to be assumed for the within-class response times. In this paper, it is demonstrated that these parametric within-subject approaches may produce false positives and biased parameter estimates if the assumption concerning the response time distribution is violated. A semi-parametric approach is proposed which resorts to categorized response times. This approach is shown to hardly produce false positives and parameter bias. In addition, the semi-parametric approach results in approximately the same power as the parametric approach. © 2017 The British Psychological Society.

Differential item functioning magnitude and impact measures from item response theory models.

PubMed

Kleinman, Marjorie; Teresi, Jeanne A

2016-01-01

Measures of magnitude and impact of differential item functioning (DIF) at the item and scale level, respectively are presented and reviewed in this paper. Most measures are based on item response theory models. Magnitude refers to item level effect sizes, whereas impact refers to differences between groups at the scale score level. Reviewed are magnitude measures based on group differences in the expected item scores and impact measures based on differences in the expected scale scores. The similarities among these indices are demonstrated. Various software packages are described that provide magnitude and impact measures, and new software presented that computes all of the available statistics conveniently in one program with explanations of their relationships to one another.

Using Response-Time Constraints in Item Selection To Control for Differential Speededness in Computerized Adaptive Testing. LSAC Research Report Series.

ERIC Educational Resources Information Center

van der Linden, Wim J.; Scrams, David J.; Schnipke, Deborah L.

This paper proposes an item selection algorithm that can be used to neutralize the effect of time limits in computer adaptive testing. The method is based on a statistical model for the response-time distributions of the test takers on the items in the pool that is updated each time a new item has been administered. Predictions from the model are…

The Spanish version of the Self-Determination Inventory Student Report: application of item response theory to self-determination measurement.

PubMed

Mumbardó-Adam, C; Guàrdia-Olmos, J; Giné, C; Raley, S K; Shogren, K A

2018-04-01

A new measure of self-determination, the Self-Determination Inventory: Student Report (Spanish version), has recently been adapted and empirically validated in Spanish language. As it is the first instrument intended to measure self-determination in youth with and without disabilities, there is a need to further explore and strengthen its psychometric analysis based on item response patterns. Through item response theory approach, this study examined item observed distributions across the essential characteristics of self-determination. The results demonstrated satisfactory to excellent item functioning patterns across characteristics, particularly within agentic action domains. Increased variability across items was also found within action-control beliefs dimensions, specifically within the self-realisation subdomain. These findings further support the instrument's psychometric properties and outline future research directions. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Evaluation of the Multiple Sclerosis Walking Scale-12 (MSWS-12) in a Dutch sample: Application of item response theory.

PubMed

Mokkink, Lidwine Brigitta; Galindo-Garre, Francisca; Uitdehaag, Bernard Mj

2016-12-01

The Multiple Sclerosis Walking Scale-12 (MSWS-12) measures walking ability from the patients' perspective. We examined the quality of the MSWS-12 using an item response theory model, the graded response model (GRM). A total of 625 unique Dutch multiple sclerosis (MS) patients were included. After testing for unidimensionality, monotonicity, and absence of local dependence, a GRM was fit and item characteristics were assessed. Differential item functioning (DIF) for the variables gender, age, duration of MS, type of MS and severity of MS, reliability, total test information, and standard error of the trait level (θ) were investigated. Confirmatory factor analysis showed a unidimensional structure of the 12 items of the scale, explaining 88% of the variance. Item 2 did not fit into the GRM model. Reliability was 0.93. Items 8 and 9 (of the 11 and 12 item version respectively) showed DIF on the variable severity, based on the Expanded Disability Status Scale (EDSS). However, the EDSS is strongly related to the content of both items. Our results confirm the good quality of the MSWS-12. The trait level (θ) scores and item parameters of both the 12- and 11-item versions were highly comparable, although we do not suggest to change the content of the MSWS-12. © The Author(s), 2016.

Prospective validation of immunological infiltrate for prediction of response to neoadjuvant chemotherapy in HER2-negative breast cancer--a substudy of the neoadjuvant GeparQuinto trial.

PubMed

Issa-Nummer, Yasmin; Darb-Esfahani, Silvia; Loibl, Sibylle; Kunz, Georg; Nekljudova, Valentina; Schrader, Iris; Sinn, Bruno Valentin; Ulmer, Hans-Ullrich; Kronenwett, Ralf; Just, Marianne; Kühn, Thorsten; Diebold, Kurt; Untch, Michael; Holms, Frank; Blohmer, Jens-Uwe; Habeck, Jörg-Olaf; Dietel, Manfred; Overkamp, Friedrich; Krabisch, Petra; von Minckwitz, Gunter; Denkert, Carsten

2013-01-01

We have recently described an increased lymphocytic infiltration rate in breast carcinoma tissue is a significant response predictor for anthracycline/taxane-based neoadjuvant chemotherapy (NACT). The aim of this study was to prospectively validate the tumor-associated lymphocyte infiltrate as predictive marker for response to anthracycline/taxane-based NACT. The immunological infiltrate was prospectively evaluated in a total of 313 core biopsies from HER2 negative patients of the multicenter PREDICT study, a substudy of the neoadjuvant GeparQuinto study. Intratumoral lymphocytes (iTuLy), stromal lymphocytes (strLy) as well as lymphocyte-predominant breast cancer (LPBC) were evaluated by histopathological assessment. Pathological complete response (pCR) rates were analyzed and compared between the defined subgroups using the exact test of Fisher. Patients with lymphocyte-predominant breast cancer (LPBC) had a significantly increased pCR rate of 36.6%, compared to non-LPBC patients (14.3%, p<0.001). LPBC and stromal lymphocytes were significantly independent predictors for pCR in multivariate analysis (LPBC: OR 2.7, p = 0.003, strLy: OR 1.2, p = 0.01). The amount of intratumoral lymphocytes was significantly predictive for pCR in univariate (OR 1.2, p = 0.01) but not in multivariate logistic regression analysis (OR 1.2, p = 0.11). Confirming previous investigations of our group, we have prospectively validated in an independent cohort that an increased immunological infiltrate in breast tumor tissue is predictive for response to anthracycline/taxane-based NACT. Patients with LPBC and increased stromal lymphocyte infiltration have significantly increased pCR rates. The lymphocytic infiltrate is a promising additional parameter for histopathological evaluation of breast cancer core biopsies.

Clinical Benefit of Long-Term Adalimumab Treatment in Patients With Crohn's Disease Following Loss of Response or Intolerance to Infliximab: 96-Week Efficacy Data From GAIN/ADHERE Trials.

PubMed

Panaccione, Remo; Sandborn, William J; D'Haens, Geert; Wolf, Douglas C; Berg, Sofie; Maa, Jen-Fue; Petersson, Joel; Robinson, Anne M

2018-04-25

In the 4-week GAIN clinical trial, adalimumab was efficacious in inducing remission in patients with moderate to severe Crohn's disease (CD) who had prior loss of response/intolerance to infliximab. The efficacy and safety of adalimumab in these patients are reported here up to 96 weeks or for 3 years, respectively, in ADHERE open-label extension study. Patients who completed GAIN could enrol in ADHERE and receive open-label adalimumab 40 mg every other week. Efficacy variables included clinical response (Crohn's Disease Activity Index [CDAI] decrease from baseline ≥70/≥100 points [CR-70/CR-100]) and remission (CDAI<150), steroid discontinuation and fistula remission (absence of drainage). Data were reported using hybrid non-responder imputation (hNRI), last observation carried forward and as-observed analysis. Subgroup analyses were performed by randomised group in GAIN and by Week 4 efficacy in GAIN. Safety was also assessed. A total of 310 patients from GAIN enrolled in ADHERE. CR-70, CR-100 and remission rates at Week 96 were 39.0%, 35.5% and 26.5% (hNRI), respectively. Of the patients with CR-70 response or remission at Week 4 of GAIN, 45.5% and 44.4% (hNRI), respectively, maintained effect at Week 96. Steroid discontinuation and steroid-free remission rates increased from Week 12 to 96 in patients using corticosteroids at GAIN baseline. Long-term adalimumab maintenance therapy led to sustained clinical remission and response, and steroid discontinuation in a considerable proportion of patients with CD previously treated with infliximab. No new safety signals were observed in this patient population.

Hungry for Life: How the arcuate nucleus and neuropeptide Y may play a critical role in mediating the benefits of calorie restriction

PubMed Central

Minor, Robin K.; Chang, Joy W.; de Cabo, Rafael

2009-01-01

Laboratory studies consistently demonstrate extended lifespan in animals on calorie restriction (CR), where total caloric intake is reduced by 10–40% but adequate nutrition is otherwise maintained. CR has been further shown to delay the onset and severity of chronic diseases associated with aging such as cancer, and to extend the functional health span of important functions including cognition. Less understood are the underlying mechanisms through which CR might act to induce such alterations. One theory postulates that CR’s beneficial effects are intimately tied to the neuroendocrine response to low energy availability, of which the arcuate nucleus in the hypothalamus plays a pivotal role. Neuropeptide Y (NPY), a neurotransmitter in the front line of the arcuate response to low energy availability, is the primary hunger signal affected by CR and therefore may be a critical mechanism for lifespan extension. PMID:19041366

Contact resonance atomic force microscopy imaging in air and water using photothermal excitation

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

Kocun, Marta; Labuda, Aleksander; Gannepalli, Anil

2015-08-15

Contact Resonance Force Microscopy (CR-FM) is a leading atomic force microscopy technique for measuring viscoelastic nano-mechanical properties. Conventional piezo-excited CR-FM measurements have been limited to imaging in air, since the “forest of peaks” frequency response associated with acoustic excitation methods effectively masks the true cantilever resonance. Using photothermal excitation results in clean contact, resonance spectra that closely match the ideal frequency response of the cantilever, allowing unambiguous and simple resonance frequency and quality factor measurements in air and liquids alike. This extends the capabilities of CR-FM to biologically relevant and other soft samples in liquid environments. We demonstrate CR-FM inmore » air and water on both stiff silicon/titanium samples and softer polystyrene-polyethylene-polypropylene polymer samples with the quantitative moduli having very good agreement between expected and measured values.« less

Ribosomal protein S6 kinase 1 signaling regulates mammalian lifespan

PubMed Central

Selman, Colin; Tullet, Jennifer M.A.; Wieser, Daniela; Irvine, Elaine; Lingard, Steven J.; Choudhury, Agharul I.; Claret, Marc; Al-Qassab, Hind; Carmignac, Danielle; Ramadani, Faruk; Woods, Angela; Robinson, Iain C.A.; Schuster, Eugene; Batterham, Rachel L.; Kozma, Sara C.; Thomas, George; Carling, David; Okkenhaug, Klaus; Thornton, Janet M.; Partridge, Linda; Gems, David; Withers, Dominic J.

2016-01-01

Caloric restriction (CR) protects against aging and disease but the mechanisms by which this affects mammalian lifespan are unclear. We show in mice that deletion of the nutrient-responsive mTOR (mammalian target of rapamycin) signaling pathway component ribosomal S6 protein kinase 1 (S6K1) led to increased lifespan and resistance to age-related pathologies such as bone, immune and motor dysfunction and loss of insulin sensitivity. Deletion of S6K1 induced gene expression patterns similar to those seen in CR or with pharmacological activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), a conserved regulator of the metabolic response to CR. Our results demonstrate that S6K1 influences healthy mammalian lifespan, and suggest therapeutic manipulation of S6K1 and AMPK might mimic CR and provide broad protection against diseases of aging. PMID:19797661

Using Data Augmentation and Markov Chain Monte Carlo for the Estimation of Unfolding Response Models

ERIC Educational Resources Information Center

Johnson, Matthew S.; Junker, Brian W.

2003-01-01

Unfolding response models, a class of item response theory (IRT) models that assume a unimodal item response function (IRF), are often used for the measurement of attitudes. Verhelst and Verstralen (1993)and Andrich and Luo (1993) independently developed unfolding response models by relating the observed responses to a more common monotone IRT…

A Study of Bayesian Estimation and Comparison of Response Time Models in Item Response Theory

ERIC Educational Resources Information Center

Suh, Hongwook

2010-01-01

Response time has been regarded as an important source for investigating the relationship between human performance and response speed. It is important to examine the relationship between response time and item characteristics, especially in the perspective of the relationship between response time and various factors that affect examinee's…

Item development process and analysis of 50 case-based items for implementation on the Korean Nursing Licensing Examination.

PubMed

Park, In Sook; Suh, Yeon Ok; Park, Hae Sook; Kang, So Young; Kim, Kwang Sung; Kim, Gyung Hee; Choi, Yeon-Hee; Kim, Hyun-Ju

2017-01-01

The purpose of this study was to improve the quality of items on the Korean Nursing Licensing Examination by developing and evaluating case-based items that reflect integrated nursing knowledge. We conducted a cross-sectional observational study to develop new case-based items. The methods for developing test items included expert workshops, brainstorming, and verification of content validity. After a mock examination of undergraduate nursing students using the newly developed case-based items, we evaluated the appropriateness of the items through classical test theory and item response theory. A total of 50 case-based items were developed for the mock examination, and content validity was evaluated. The question items integrated 34 discrete elements of integrated nursing knowledge. The mock examination was taken by 741 baccalaureate students in their fourth year of study at 13 universities. Their average score on the mock examination was 57.4, and the examination showed a reliability of 0.40. According to classical test theory, the average level of item difficulty of the items was 57.4% (80%-100% for 12 items; 60%-80% for 13 items; and less than 60% for 25 items). The mean discrimination index was 0.19, and was above 0.30 for 11 items and 0.20 to 0.29 for 15 items. According to item response theory, the item discrimination parameter (in the logistic model) was none for 10 items (0.00), very low for 20 items (0.01 to 0.34), low for 12 items (0.35 to 0.64), moderate for 6 items (0.65 to 1.34), high for 1 item (1.35 to 1.69), and very high for 1 item (above 1.70). The item difficulty was very easy for 24 items (below -2.0), easy for 8 items (-2.0 to -0.5), medium for 6 items (-0.5 to 0.5), hard for 3 items (0.5 to 2.0), and very hard for 9 items (2.0 or above). The goodness-of-fit test in terms of the 2-parameter item response model between the range of 2.0 to 0.5 revealed that 12 items had an ideal correct answer rate. We surmised that the low reliability of the mock examination was influenced by the timing of the test for the examinees and the inappropriate difficulty of the items. Our study suggested a methodology for the development of future case-based items for the Korean Nursing Licensing Examination.

Fitting measurement models to vocational interest data: are dominance models ideal?

PubMed

Tay, Louis; Drasgow, Fritz; Rounds, James; Williams, Bruce A

2009-09-01

In this study, the authors examined the item response process underlying 3 vocational interest inventories: the Occupational Preference Inventory (C.-P. Deng, P. I. Armstrong, & J. Rounds, 2007), the Interest Profiler (J. Rounds, T. Smith, L. Hubert, P. Lewis, & D. Rivkin, 1999; J. Rounds, C. M. Walker, et al., 1999), and the Interest Finder (J. E. Wall & H. E. Baker, 1997; J. E. Wall, L. L. Wise, & H. E. Baker, 1996). Item response theory (IRT) dominance models, such as the 2-parameter and 3-parameter logistic models, assume that item response functions (IRFs) are monotonically increasing as the latent trait increases. In contrast, IRT ideal point models, such as the generalized graded unfolding model, have IRFs that peak where the latent trait matches the item. Ideal point models are expected to fit better because vocational interest inventories ask about typical behavior, as opposed to requiring maximal performance. Results show that across all 3 interest inventories, the ideal point model provided better descriptions of the response process. The importance of specifying the correct item response model for precise measurement is discussed. In particular, scores computed by a dominance model were shown to be sometimes illogical: individuals endorsing mostly realistic or mostly social items were given similar scores, whereas scores based on an ideal point model were sensitive to which type of items respondents endorsed.

[Schizotypal Personality Questionnaire-Brief - Likert format: Factor structure analysis in general population in France].

PubMed

Ferchiou, A; Todorov, L; Lajnef, M; Baudin, G; Pignon, B; Richard, J-R; Leboyer, M; Szöke, A; Schürhoff, F

2017-12-01

The main objective of the study was to explore the factorial structure of the French version of the Schizotypal Personality Questionnaire-Brief (SPQ-B) in a Likert format, in a representative sample of the general population. In addition, differences in the dimensional scores of schizotypy according to gender and age were analyzed. As the study in the general population of schizotypal traits and its determinants has been recently proposed as a way toward the understanding of aetiology and pathophysiology of schizophrenia, consistent self-report tools are crucial to measure psychometric schizotypy. A shorter version of the widely used Schizotypal Personality Questionnaire (SPQ-Brief) has been extensively investigated in different countries, particularly in samples of students or clinical adolescents, and more recently, a few studies used a Likert-type scale format which allows partial endorsement of items and reduces the risk of defensive answers. A sample of 233 subjects representative of the adult population from an urban area near Paris (Créteil) was recruited using the "itinerary method". They completed the French version of the SPQ-B with a 5-point Likert-type response format (1=completely disagree; 5=completely agree). We examined the dimensional structure of the French version of the SPQ-B with a Principal Components Analysis (PCA) followed by a promax rotation. Factor selection was based on Eigenvalues over 1.0 (Kaiser's criterion), Cattell's Scree-plot test, and interpretability of the factors. Items with loadings greater than 0.4 were retained for each dimension. The internal consistency estimate of the dimensions was calculated with Cronbach's α. In order to study the influence of age and gender, we carried out a simple linear regression with the subscales as dependent variables. Our sample was composed of 131 women (mean age=52.5±18.2 years) and 102 men (mean age=53±18.1 years). SPQ-B Likert total scores ranged from 22 to 84 points (mean=43.6±13). Factor analysis resulted in a 3-factor solution that explained 47.7% of the variance. Factor 1 (disorganized; 10 items) included items related to "odd behavior", "odd speech", as well as "social anxiety", one item of "constricted affect" and one item of "ideas of reference". Factor 2 (interpersonal; 7 items) included items related to "no close friends", "constricted affect", and three of the items of "suspiciousness". Factor 3 (cognitive-perceptual; 5 items) included items related to "ideas of reference", "magical thinking", "unusual perceptual experiences" and one item of "suspiciousness". Coefficient α for the three subscales and total scale were respectively 0.81, 0.81, 0.77 and 0.88. We found no differences in total schizotypy and the three dimensions scores according to age and sex. Factor analysis of the French version of the SPQ-B in a Likert format confirmed the three-factor structure of schizotypy. We found a pure cognitive perceptual dimension including the most representative positive features. As expected, "Suspiciousness" subscale is included in both positive and negative dimensions, but mainly in the negative dimension. Surprisingly, "social anxiety" subscale is included in the disorganized dimension in our analysis. The SPQ-B in a Likert format demonstrated good internal reliability for both total and subscales scores. Unlike previous published results, we did not find any influence of age or gender on schizotypal dimensions. Copyright © 2016 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Measuring ability to assess claims about treatment effects: a latent trait analysis of items from the 'Claim Evaluation Tools' database using Rasch modelling.

PubMed

Austvoll-Dahlgren, Astrid; Guttersrud, Øystein; Nsangi, Allen; Semakula, Daniel; Oxman, Andrew D

2017-05-25

The Claim Evaluation Tools database contains multiple-choice items for measuring people's ability to apply the key concepts they need to know to be able to assess treatment claims. We assessed items from the database using Rasch analysis to develop an outcome measure to be used in two randomised trials in Uganda. Rasch analysis is a form of psychometric testing relying on Item Response Theory. It is a dynamic way of developing outcome measures that are valid and reliable. To assess the validity, reliability and responsiveness of 88 items addressing 22 key concepts using Rasch analysis. We administrated four sets of multiple-choice items in English to 1114 people in Uganda and Norway, of which 685 were children and 429 were adults (including 171 health professionals). We scored all items dichotomously. We explored summary and individual fit statistics using the RUMM2030 analysis package. We used SPSS to perform distractor analysis. Most items conformed well to the Rasch model, but some items needed revision. Overall, the four item sets had satisfactory reliability. We did not identify significant response dependence between any pairs of items and, overall, the magnitude of multidimensionality in the data was acceptable. The items had a high level of difficulty. Most of the items conformed well to the Rasch model's expectations. Following revision of some items, we concluded that most of the items were suitable for use in an outcome measure for evaluating the ability of children or adults to assess treatment claims. © 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.

Response pattern of depressive symptoms among college students: What lies behind items of the Beck Depression Inventory-II?

PubMed

de Sá Junior, Antonio Reis; de Andrade, Arthur Guerra; Andrade, Laura Helena; Gorenstein, Clarice; Wang, Yuan-Pang

2018-07-01

This study examines the response pattern of depressive symptoms in a nationwide student sample, through item analyses of a rating scale by both classical test theory (CTT) and item response theory (IRT). The 21-item Beck Depression Inventory-II (BDI-II) was administered to 12,711 college students. First, the psychometric properties of the scale were described. Thereafter, the endorsement probability of depressive symptom in each scale item was analyzed through CTT and IRT. Graphical plots depicted the endorsement probability of scale items and intensity of depression. Three items of different difficulty level were compared through CTT and IRT approach. Four in five students reported the presence of depressive symptoms. The BDI-II items presented good reliability and were distributed along the symptomatic continuum of depression. Similarly, in both CTT and IRT approaches, the item 'changes in sleep' was easily endorsed, 'loss of interest' moderately and 'suicidal thoughts' hardly. Graphical representation of BDI-II of both methods showed much equivalence in terms of item discrimination and item difficulty. The item characteristic curve of the IRT method provided informative evaluation of item performance. The inventory was applied only in college students. Depressive symptoms were frequent psychopathological manifestations among college students. The performance of the BDI-II items indicated convergent results from both methods of analysis. While the CTT was easy to understand and to apply, the IRT was more complex to understand and to implement. Comprehensive assessment of the functioning of each BDI-II item might be helpful in efficient detection of depressive conditions in college students. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessing items on the SF-8 Japanese version for health-related quality of life: a psychometric analysis based on the nominal categories model of item response theory.

PubMed

Tokuda, Yasuharu; Okubo, Tomoya; Ohde, Sachiko; Jacobs, Joshua; Takahashi, Osamu; Omata, Fumio; Yanai, Haruo; Hinohara, Shigeaki; Fukui, Tsuguya

2009-06-01

The Short Form-8 (SF-8) questionnaire is a commonly used 8-item instrument of health-related quality of life (QOL) and provides a health profile of eight subdimensions. Our aim was to examine the psychometric properties of the Japanese version of the SF-8 instrument using methodology based on nominal categories model. Using data from an adjusted random sample from a nationally representative panel, the nominal categories modeling was applied to SF-8 items to characterize coverage of the latent trait (theta). Probabilities for response choices were described as functions on the latent trait. Information functions were generated based on the estimated item parameters. A total of 3344 participants (53%, women; median age, 35 years) provided responses. One factor was retained (eigenvalue, 4.65; variance proportion of 0.58) and used as theta. All item response category characteristic curves satisfied the monotonicity assumption in accurate order with corresponding ordinal responses. Four items (general health, bodily pain, vitality, and mental health) cover most of the spectrum of theta, while the other four items (physical function, role physical [role limitations because of physical health], social functioning, and role emotional [role limitations because of emotional problems] ) cover most of the negative range of theta. Information function for all items combined peaked at -0.7 of theta (information = 18.5) and decreased with increasing theta. The SF-8 instrument performs well among those with poor QOL across the continuum of the latent trait and thus can recognize more effectively persons with relatively poorer QOL than those with relatively better QOL.

Update on the Child's Challenging Behaviour Scale following evaluation using Rasch analysis.

PubMed

Bourke-Taylor, H M; Pallant, J F; Law, M

2014-03-01

The Child's Challenging Behaviour Scale (CCBS) was designed to measure a mother's rating of her child's challenging behaviours. The CCBS was initially developed for mothers of school-aged children with developmental disability and has previously been shown to have good psychometric properties using classical test theory techniques. The aim of this study was to use Rasch analysis to fully evaluate all aspects of the scale, including response format, item fit, dimensionality and targeting. The sample consisted of 152 mothers of a school-aged child (aged 5-18 years) with a disability. Mothers were recruited via websites and mail-out newsletters through not-for-profit organizations that supported families with disabilities. Respondents completed a survey which included the 11 items of the CCBS. Rasch analysis was conducted on these responses using the RUMM2030 package. Rasch analysis of the CCBS revealed serious threshold disordering for nine of the 11 items, suggesting problems with the 5-point response format used for the scale. The neutral midpoint of the response format was subsequently removed to create a 4-point scale. High levels of local dependency were detected among two pairs of items, resulting in the removal of two items (item 7 and item 1). The final nine-item version of the scale (CCBS Version 2) was unidimensional, well targeted, showed good fit to the Rasch model, and strong internal consistency. To achieve fit to the Rasch model it was necessary to make two modifications to the CCBS scale. The resulting nine-item scale with a 4-point response format showed excellent psychometric properties, supporting its internal validity. © 2013 John Wiley & Sons Ltd.

Donor-Specific Indirect Pathway Analysis Reveals a B-Cell-Independent Signature Which Reflects Outcomes in Kidney Transplant Recipients

PubMed Central

Haynes, L. D.; Jankowska-Gan, E.; Sheka, A.; Keller, M. R.; Hernandez-Fuentes, M. P.; Lechler, R. I.; Seyfert-Margolis, V.; Turka, L. A.; Newell, K. A.; Burlingham, W. J.

2012-01-01

To investigate the role of donor-specific indirect pathway T cells in renal transplant tolerance, we analyzed responses in peripheral blood of 45 patients using the trans-vivo delayed-type hypersensitivity assay. Subjects were enrolled into five groups—identical twin, clinically tolerant (TOL), steroid monotherapy (MONO), standard immunosuppression (SI) and chronic rejection (CR)—based on transplant type, posttransplant immunosuppression and graft function. The indirect pathway was active in all groups except twins but distinct intergroup differences were evident, corresponding to clinical status. The antidonor indirect pathway T effector response increased across patient groups (TOL < MONO < SI < CR; p < 0.0001) whereas antidonor indirect pathway T regulatory response decreased (TOL > MONO = SI > CR; p < 0.005). This pattern differed from that seen in circulating naïve B-cell numbers and in a cross-platform biomarker analysis, where patients on monotherapy were not ranked closest to TOL patients, but rather were indistinguishable from chronically rejecting patients. Cross-sectional analysis of the indirect pathway revealed a spectrum in T-regulatory:T-effector balance, ranging from TOL patients having predominantly regulatory responses to CR patients having predominantly effector responses. Therefore, the indirect pathway measurements reflect a distinct aspect of tolerance from the recently reported elevation of circulating naïve B cells, which was apparent only in recipients off immunosuppression. PMID:22151236

Open-label Bendamustine Monotherapy for Pediatric Patients With Relapsed or Refractory Acute Leukemia: Efficacy and Tolerability

PubMed Central

Brown, Patrick; Megason, Gail; Ahn, Hyo Seop; Cho, Bin; Kirov, Ivan; Frankel, Lawrence; Aplenc, Richard; Bensen-Kennedy, Debra; Munteanu, Mihaela; Weaver, Jennifer; Harker-Murray, Paul

2014-01-01

This open-label, single-arm, phase I/II, dose-escalation study was designed to determine the recommended phase II dose (RP2D), pharmacokinetics, tolerability, and efficacy of bendamustine in pediatric patients (age ranging from 1 to 20 y) with histologically proven relapsed/refractory acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML). Patients (27 with ALL, 16 with AML) received intravenous bendamustine on days 1 and 2 of each treatment cycle. Phase I involved planned dose escalation of bendamustine to establish the RP2D for phase II. Objectives included overall response rate, duration of response, and tolerability. Eleven patients were treated in phase I, and the RP2D was 120 mg/m2. In phase II, 32 patients received bendamustine 120 mg/m2. Two patients with ALL (bendamustine 90 mg/m2) experienced complete response (CR). Among patients who received bendamustine 120 mg/m2, 2 experienced partial response (PR); 7 had stable disease. The overall response rate (CR+CR without platelet recovery [CRp]) was 4.7% and biological activity rate (CR+CRp+PR) was 9.3%. No AML patients responded. The most common adverse events were anemia, neutropenia, thrombocytopenia, pyrexia, nausea, vomiting, and diarrhea. Bendamustine monotherapy has acceptable tolerability in heavily pretreated children with relapsed/refractory ALL or AML and appears to have some activity in ALL, warranting further studies in combination trials. PMID:24072240

Caloric restriction coupled with radiation decreases metastatic burden in triple negative breast cancer

PubMed Central

Simone, Brittany A.; Dan, Tu; Palagani, Ajay; Jin, Lianjin; Han, Sunny Y.; Wright, Christopher; Savage, Jason E.; Gitman, Robert; Lim, Meng Kieng; Palazzo, Juan; Mehta, Minesh P.; Simone, Nicole L.

2016-01-01

ABSTRACT Purpose: Metastatic breast cancer is devastating and triple negative breast cancers (TNBC) have a higher propensity for metastasis. Improved local control upfront in this aggressive cancer could potentially decrease its propensity toward metastasis. We sought to determine if using caloric restriction (CR) as a systemic therapy, combined with radiation therapy (IR) to the primary tumor, may impact metastatic disease. Methods: An orthotopic mouse model using a highly metastatic, luciferase-tagged TNBC cell line (4T1), was used to generate palpable tumors. Mice were then treated with CR, IR, and a combination of the two. In vivo imaging was performed for metastatic evaluation. Molecular evaluation of the tumors was performed, generating a mechanistic hypothesis for CR, which was then tested with pertinent pathway inhibition in the model. Results: CR significantly increased the time to developing metastases, decreased the overall number and volume of lung metastases, and increased survival. CR decreased proliferation, increased apoptosis and globally downregulated the IGF-1R signaling pathway. Adding an IGF-1R/INSR inhibitor to local IR in vivo accomplished a decrease in metastases similar to CR plus IR, demonstrating the importance of the IGF-1R signaling pathway, and underscoring it as a possible mechanism for CR. Conclusions: CR decreased metastatic burden and therefore may complement cytotoxic therapies being used in the clinical setting for metastatic disease. Downregulation of the IGF-1R pathway, is in part responsible for this response and modulating IGF-1R directly resulted in similar improved progression-free survival. The novel use of CR has the potential to enhance clinical outcomes for patients with metastatic breast cancer. PMID:27027731

Biosorption of Cr(VI) by Ceratocystis paradoxa MSR2 Using Isotherm Modelling, Kinetic Study and Optimization of Batch Parameters Using Response Surface Methodology

PubMed Central

Ramalingam, Chidambaram

2015-01-01

This study is focused on the possible use of Ceratocystis paradoxa MSR2 native biomass for Cr(VI) biosorption. The influence of experimental parameters such as initial pH, temperature, biomass dosage, initial Cr(VI) concentration and contact time were optimized using batch systems as well as response surface methodology (RSM). Maximum Cr(VI) removal of 68.72% was achieved, at an optimal condition of biomass dosage 2g L−1, initial Cr(VI) concentration of 62.5 mg L−1 and contact time of 60 min. The closeness of the experimental and the predicted values exhibit the success of RSM. The biosorption mechanism of MSR2 biosorbent was well described by Langmuir isotherm and a pseudo second order kinetic model, with a high regression coefficient. The thermodynamic study also revealed the spontaneity and exothermic nature of the process. The surface characterization using FT-IR analysis revealed the involvement of amine, carbonyl and carboxyl groups in the biosorption process. Additionally, desorption efficiency of 92% was found with 0.1 M HNO3. The Cr(VI) removal efficiency, increased with increase in metal ion concentration, biomass concentration, temperature but with a decrease in pH. The size of the MSR2 biosorbent material was found to be 80 μm using particle size analyzer. Atomic force microscopy (AFM) visualizes the distribution of Cr(VI) on the biosorbent binding sites with alterations in the MSR2 surface structure. The SEM-EDAX analysis was also used to evaluate the binding characteristics of MSR2 strain with Cr(VI) metals. The mechanism of Cr(VI) removal of MSR2 biomass has also been proposed. PMID:25822726

The General Isothermal Oxidation Behavior of Cu-8Cr-4Nb

NASA Technical Reports Server (NTRS)

Thomas-Ogbuji, L. U.; Gray, Hugh R. (Technical Monitor)

2002-01-01

Oxidation kinetics of Cu-8Cr-4Nb was investigated by TGA (thermogravimetric) exposures between 500 and 900-C (at 25-50 C intervals) and the oxide scale morphologies examined by microscopy and micro-analysis. Because Cu-8Cr-4Nb is comprised of fine Cr2Nb precipitates in a Cu matrix, the results were interpreted by comparison with the behavior of copper (OFHC) and 'NARloy-Z' (a rival candidate material for thrust cell liner applications in advanced rocket engines) under the same conditions. While NARloy-Z and Cu exhibited identical oxidation behavior, Cu-8Cr-4Nb differed markedly in several respects: below approx. 700 C its oxidation rates were significantly lower than those of Cu; At higher temperatures its oxidation rates fell into two categories: an initial rate exceeding that of Cu, and a terminal rate comparable to that of Cu. Differences in oxide morphologies paralleled the kinetic differences at higher temperature: While NARloy-Z and Cu produced a uniform oxide scale of Cu2O inner layer and CuO outer layer, the inner (Cu2O) layer on Cu-8Cr-4Nb was stratified, with a highly porous/spongy inner stratum (responsible for the fast initial kinetics) and a dense/blocky outer stratum (corresponding to the slow terminal kinetics). Single and spinel oxides of Nb and Cr were found at the interface between the oxide scale and Cu-8Cr-4Nb substrate and it appears that these oxides were responsible for its suppressed oxidation rates at the intermediate temperatures. No difference was found between Cu-8Cr-4Nb oxidation in air and in oxygen at 1.0 atm.

Using Explanatory Item Response Models to Evaluate Complex Scientific Tasks Designed for the Next Generation Science Standards

NASA Astrophysics Data System (ADS)

Chiu, Tina

This dissertation includes three studies that analyze a new set of assessment tasks developed by the Learning Progressions in Middle School Science (LPS) Project. These assessment tasks were designed to measure science content knowledge on the structure of matter domain and scientific argumentation, while following the goals from the Next Generation Science Standards (NGSS). The three studies focus on the evidence available for the success of this design and its implementation, generally labelled as "validity" evidence. I use explanatory item response models (EIRMs) as the overarching framework to investigate these assessment tasks. These models can be useful when gathering validity evidence for assessments as they can help explain student learning and group differences. In the first study, I explore the dimensionality of the LPS assessment by comparing the fit of unidimensional, between-item multidimensional, and Rasch testlet models to see which is most appropriate for this data. By applying multidimensional item response models, multiple relationships can be investigated, and in turn, allow for a more substantive look into the assessment tasks. The second study focuses on person predictors through latent regression and differential item functioning (DIF) models. Latent regression models show the influence of certain person characteristics on item responses, while DIF models test whether one group is differentially affected by specific assessment items, after conditioning on latent ability. Finally, the last study applies the linear logistic test model (LLTM) to investigate whether item features can help explain differences in item difficulties.

A Stepwise Test Characteristic Curve Method to Detect Item Parameter Drift

ERIC Educational Resources Information Center

Guo, Rui; Zheng, Yi; Chang, Hua-Hua

2015-01-01

An important assumption of item response theory is item parameter invariance. Sometimes, however, item parameters are not invariant across different test administrations due to factors other than sampling error; this phenomenon is termed item parameter drift. Several methods have been developed to detect drifted items. However, most of the…

Optimal Item Selection with Credentialing Examinations.

ERIC Educational Resources Information Center

Hambleton, Ronald K.; And Others

The study compared two promising item response theory (IRT) item-selection methods, optimal and content-optimal, with two non-IRT item selection methods, random and classical, for use in fixed-length certification exams. The four methods were used to construct 20-item exams from a pool of approximately 250 items taken from a 1985 certification…

An HIV/AIDS Knowledge Scale for Adolescents: Item Response Theory Analyses Based on Data from a Study in South Africa and Tanzania

ERIC Educational Resources Information Center

Aaro, Leif E.; Breivik, Kyrre; Klepp, Knut-Inge; Kaaya, Sylvia; Onya, Hans E.; Wubs, Annegreet; Helleve, Arnfinn; Flisher, Alan J.

2011-01-01

A 14-item human immunodeficiency virus/acquired immunodeficiency syndrome knowledge scale was used among school students in 80 schools in 3 sites in Sub-Saharan Africa (Cape Town and Mankweng, South Africa, and Dar es Salaam, Tanzania). For each item, an incorrect or don't know response was coded as 0 and correct response as 1. Exploratory factor…

Using SAS PROC MCMC for Item Response Theory Models

PubMed Central

Samonte, Kelli

2014-01-01

Interest in using Bayesian methods for estimating item response theory models has grown at a remarkable rate in recent years. This attentiveness to Bayesian estimation has also inspired a growth in available software such as WinBUGS, R packages, BMIRT, MPLUS, and SAS PROC MCMC. This article intends to provide an accessible overview of Bayesian methods in the context of item response theory to serve as a useful guide for practitioners in estimating and interpreting item response theory (IRT) models. Included is a description of the estimation procedure used by SAS PROC MCMC. Syntax is provided for estimation of both dichotomous and polytomous IRT models, as well as a discussion on how to extend the syntax to accommodate more complex IRT models. PMID:29795834

Effects of Aging and IQ on Item and Associative Memory

ERIC Educational Resources Information Center

Ratcliff, Roger; Thapar, Anjali; McKoon, Gail

2011-01-01

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual…

A Bayesian Semiparametric Item Response Model with Dirichlet Process Priors

ERIC Educational Resources Information Center

Miyazaki, Kei; Hoshino, Takahiro

2009-01-01

In Item Response Theory (IRT), item characteristic curves (ICCs) are illustrated through logistic models or normal ogive models, and the probability that examinees give the correct answer is usually a monotonically increasing function of their ability parameters. However, since only limited patterns of shapes can be obtained from logistic models…

Item Response Theory Modeling of the Philadelphia Naming Test

ERIC Educational Resources Information Center

Fergadiotis, Gerasimos; Kellough, Stacey; Hula, William D.

2015-01-01

Purpose: In this study, we investigated the fit of the Philadelphia Naming Test (PNT; Roach, Schwartz, Martin, Grewal, & Brecher, 1996) to an item-response-theory measurement model, estimated the precision of the resulting scores and item parameters, and provided a theoretical rationale for the interpretation of PNT overall scores by relating…

An Evaluation of Three Approximate Item Response Theory Models for Equating Test Scores.

ERIC Educational Resources Information Center

Marco, Gary L.; And Others

Three item response models were evaluated for estimating item parameters and equating test scores. The models, which approximated the traditional three-parameter model, included: (1) the Rasch one-parameter model, operationalized in the BICAL computer program; (2) an approximate three-parameter logistic model based on coarse group data divided…

Empirical Histograms in Item Response Theory with Ordinal Data

ERIC Educational Resources Information Center

Woods, Carol M.

2007-01-01

The purpose of this research is to describe, test, and illustrate a new implementation of the empirical histogram (EH) method for ordinal items. The EH method involves the estimation of item response model parameters simultaneously with the approximation of the distribution of the random latent variable (theta) as a histogram. Software for the EH…

Discussion of David Thissen's Bad Questions: An Essay Involving Item Response Theory

ERIC Educational Resources Information Center

Ackerman, Terry

2016-01-01

In this commentary, University of North Carolina's associate dean of research and assessment at the School of Education Terry Ackerman poses questions and shares his thoughts on David Thissen's essay, "Bad Questions: An Essay Involving Item Response Theory" (this issue). Ackerman begins by considering the two purposes of Item Response…

Data Visualization of Item-Total Correlation by Median Smoothing

ERIC Educational Resources Information Center

Yu, Chong Ho; Douglas, Samantha; Lee, Anna; An, Min

2016-01-01

This paper aims to illustrate how data visualization could be utilized to identify errors prior to modeling, using an example with multi-dimensional item response theory (MIRT). MIRT combines item response theory and factor analysis to identify a psychometric model that investigates two or more latent traits. While it may seem convenient to…

Some Issues in Item Response Theory: Dimensionality Assessment and Models for Guessing

ERIC Educational Resources Information Center

Smith, Jessalyn

2009-01-01

Currently, standardized tests are widely used as a method to measure how well schools and students meet academic standards. As a result, measurement issues have become an increasingly popular topic of study. Unidimensional item response models are used to model latent abilities and specific item characteristics. This class of models makes…

The Definition of Difficulty and Discrimination for Multidimensional Item Response Theory Models.

ERIC Educational Resources Information Center

Reckase, Mark D.; McKinley, Robert L.

A study was undertaken to develop guidelines for the interpretation of the parameters of three multidimensional item response theory models and to determine the relationship between the parameters and traditional concepts of item difficulty and discrimination. The three models considered were multidimensional extensions of the one-, two-, and…

Semiparametric Item Response Functions in the Context of Guessing

ERIC Educational Resources Information Center

Falk, Carl F.; Cai, Li

2016-01-01

We present a logistic function of a monotonic polynomial with a lower asymptote, allowing additional flexibility beyond the three-parameter logistic model. We develop a maximum marginal likelihood-based approach to estimate the item parameters. The new item response model is demonstrated on math assessment data from a state, and a computationally…

A Bayesian Beta-Mixture Model for Nonparametric IRT (BBM-IRT)

ERIC Educational Resources Information Center

Arenson, Ethan A.; Karabatsos, George

2017-01-01

Item response models typically assume that the item characteristic (step) curves follow a logistic or normal cumulative distribution function, which are strictly monotone functions of person test ability. Such assumptions can be overly-restrictive for real item response data. We propose a simple and more flexible Bayesian nonparametric IRT model…

Nonparametric Item Response Curve Estimation with Correction for Measurement Error

ERIC Educational Resources Information Center

Guo, Hongwen; Sinharay, Sandip

2011-01-01

Nonparametric or kernel regression estimation of item response curves (IRCs) is often used in item analysis in testing programs. These estimates are biased when the observed scores are used as the regressor because the observed scores are contaminated by measurement error. Accuracy of this estimation is a concern theoretically and operationally.…

Of Mice and Men: The Benefits of Caloric Restriction, Exercise, and Mimetics

PubMed Central

Mercken, Evi M.; Carboneau, Bethany A.; Krzysik-Walker, Susan M.; de Cabo, Rafael

2012-01-01

During aging there is an increasing imbalance of energy intake and expenditure resulting in obesity, frailty, and metabolic disorders. For decades, research has shown that caloric restriction (CR) and exercise can postpone detrimental aspects of aging. These two interventions invoke a similar physiological signature involving pathways associated with stress responses and mitochondrial homeostasis. Nonetheless, CR is able to delay aging processes that result in an increase of both mean and maximum lifespan, whereas exercise primarily increases healthspan. Due to the strict dietary regime necessary to achieve the beneficial effects of CR, most studies to date have focused on rodents and non-human primates. As a consequence, there is vast interest in the development of compounds such as resveratrol, metformin and rapamycin that would activate the same metabolic- and stress-response pathways induced by these interventions without actually restricting caloric intake. Therefore the scope of this review is to (i) describe the benefits of CR and exercise in healthy individuals, (ii) discuss the role of these interventions in the diseased state, and (iii) examine some of the promising pharmacological alternatives such as CR- and exercise-mimetics. PMID:22210414

Investigation of Cr(VI) adsorption onto chemically treated Helianthus annuus: optimization using response surface methodology.

PubMed

Jain, Monika; Garg, V K; Kadirvelu, K

2011-01-01

In the present study, chemically treated Helianthus annuus flowers (SHC) were used to optimize the removal efficiency for Cr(VI) by applying Response Surface Methodological approach. The surface structure of SHC was analyzed by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Analysis (EDX). Batch mode experiments were also carried out to assess the adsorption equilibrium in aqueous solution. The adsorption capacity (qe) was found to be 7.2 mg/g. The effect of three parameters, that is pH of the solution (2.0-7.0), initial concentration (10-70 mg/L) and adsorbent dose (0.05-0.5 g/100 mL) was studied for the removal of Cr(VI) by SHC. Box-Behnken model was used as an experimental design. The optimum pH, adsorbent dose and initial Cr(VI) concentration were found to be 2.0, 5.0 g/L and 40 mg/L, respectively. Under these conditions, removal efficiency of Cr(VI) was found to be 90.8%. Copyright © 2010 Elsevier Ltd. All rights reserved.

A New Procedure for Detection of Students' Rapid Guessing Responses Using Response Time

ERIC Educational Resources Information Center

Guo, Hongwen; Rios, Joseph A.; Haberman, Shelby; Liu, Ou Lydia; Wang, Jing; Paek, Insu

2016-01-01

Unmotivated test takers using rapid guessing in item responses can affect validity studies and teacher and institution performance evaluation negatively, making it critical to identify these test takers. The authors propose a new nonparametric method for finding response-time thresholds for flagging item responses that result from rapid-guessing…

A study of the oxide dispersion and recrystallization in NiCrAl prepared from preoxidized powder

NASA Technical Reports Server (NTRS)

Glasgow, T. K.

1975-01-01

The SAP technique of dispersion strengthening (formation of an oxide dispersion by preoxidation of metal powders) was applied to atomized powder of the alloy Ni-17Cr-5Al-0.2 Y. SAP-NiCrAl was worked by extrusion and rod rolling at 1205 C and by swaging at 760 C. A variety of annealing treatments were applied after working to determine the recrystallization response. NiCrAlY, similarly prepared from atomized powder, but without a preoxidation treatment, was examined for comparison. The SAP-NiCrAl of this study exhibited oxide particle size and spacing much larger than that usually observed in oxide dispersion strengthened alloys; nonetheless, it was possible to achieve abnormal (secondary) recrystallization in the SAP-NiCrAl as has been reported for other oxide dispersion strengthened alloys. In contrast, unoxidized NiCrAlY exhibited only primary recrystallization.

Effects of Anchor Item Methods on the Detection of Differential Item Functioning within the Family of Rasch Models

ERIC Educational Resources Information Center

Wang, Wen-Chung

2004-01-01

Scale indeterminacy in analysis of differential item functioning (DIF) within the framework of item response theory can be resolved by imposing 3 anchor item methods: the equal-mean-difficulty method, the all-other anchor item method, and the constant anchor item method. In this article, applicability and limitations of these 3 methods are…