Frequency Of Items Research Articles

FALSE MEMORIES FOR SEMANTIC AND CATEGORY ASSOCIATES: COMPARING RETRIEVAL STRATEGIES AND RETENTION INTERVAL

False memories are memories that people believe indeed correspond to actual events from the past. Experimental investigation of false memories involves varied methodologies, including semantic and category associate technique. While the category method depends on the frequency of intra-list items, semantic associate measures semantic association of intra-list items. The present study compares false memory generation through category and semantic associates. Additionally, the mode of retrieval (recall, recognition) and retention interval (short, long) were manipulated to measure their effect on false memory generation. The result of the study suggests that retention interval and mode of retrieval did influence false memories generated using words (semantic associates) and line drawings (category associates).

Relationship Between Patient Engagement and Depressive Symptoms Among People Living With HIV in a Mobile Health Intervention: Secondary Analysis of a Randomized Controlled Trial.

BackgroundAssociations between higher levels of patient engagement and better health outcomes have been found in face-to-face interventions; studies on such associations with mobile health (mHealth) interventions have been limited and the results are inconclusive.ObjectiveThe objective of this study is to investigate the relationship between patient engagement in an mHealth intervention and depressive symptoms using repeated measures of both patient engagement and patient outcomes at 4 time points.MethodsData were drawn from a randomized controlled trial (RCT) of an mHealth intervention aimed at reducing depressive symptoms among people living with HIV and elevated depressive symptoms. We examined the association between patient engagement and depressive symptoms in the intervention group (n=150) where participants received an adapted cognitive-behavioral stress management (CBSM) course and physical activity promotion on their WeChat social media app. Depressive symptoms were repeatedly measured using the Patient Health Questionnaire (PHQ-9) at baseline and 1 month, 2 months, and 3 months. Patient engagement was correspondingly measured by the completion rate, frequency of items completed, and time spent on the program at 1 month, 2 months, and 3 months. Latent growth curve models (LGCMs) were used to explore the relationship between patient engagement and depressive symptoms at multiple time points in the intervention.ResultsThe mean PHQ-9 scores were 10.2 (SD 4.5), 7.7 (SD 4.8), 6.5 (SD 4.7), and 6.7 (SD 4.1) at baseline, 1 month, 2 months, and 3 months, respectively. The mean completion rates were 50.6% (SD 31.8%), 51.5% (SD 32.2%), and 50.8% (SD 33.7%) at 1, 2, and 3 months, respectively; the average frequencies of items completed were 18.0 (SD 14.6), 32.6 (SD 24.8), and 47.5 (SD 37.2) at 1, 2, and 3 months, respectively, and the mean times spent on the program were 32.7 (SD 66.7), 65.4 (SD 120.8), and 96.4 (SD 180.4) minutes at 1, 2, and 3 months, respectively. LGCMs showed good model fit and indicated that a higher completion rate (β at 3 months=–2.184, P=.048) and a greater frequency of items completed (β at 3 months=–0.018, P=.04) were associated with fewer depressive symptoms at 3 months. Although not significant, similar trends were found in the abovementioned relationships at 1 and 2 months. There was no significant relationship between time spent on the program and depressive symptoms.ConclusionsThis study revealed a positive association between patient engagement and health outcomes at 3 months of an mHealth intervention using LGCMs and repeated measures data. The results underscore the importance of improving patient engagement in mHealth interventions to improve patient-centered health outcomes.Trial RegistrationChinese Clinical Trial Registry ChiCTR-IPR-17012606; https://tinyurl.com/yxb64mefInternational Registered Report Identifier (IRRID)RR2-10.1186/s12889-018-5693-1

A Comprehensive Quality Assurance Program of Small Animal Irradiators for Preclinical Radiation Research

Draeger et al. (Red Journal, 2020) raised awareness on the importance of the standardization of dosimetry protocols in pre-clinical radiobiology research and the inclusion of physicists on the research team. At our institute, a QA program of the small animal radiation research platform (SARRP, Xstrahl) that includes daily, monthly and annual tests have been implemented to ensure minimal delivery uncertainties. Details of the QA procedures, feasibility and results will be reported. End-to-end imaging and radiation isocenter coincidence testing using a Winston-Lutz phantom and EBT3 films, as well as CBCT imaging quality visual check, were performed daily by the research team. Monthly QA (mechanical and dosimetric tests such as the star-shot test and output constancy of the reference field), and annual QA (TG61 absolute dosimetry, imaging quality phantom check, output factor, beam profiles and percent depth dose measurements) were performed by the physics staff. The estimated time to complete the daily, monthly and annual tests were twenty minutes, one and two hours, respectively. The frequency of each QA item had been established based on the failure occurrence rate. The tolerance results of the daily, monthly and annual testing are displayed in the table. The results of the daily isocenter coincidence check show a discrepancy between the radiation isocenter and set-up center combined with the uncertainty from the couch movement of the image-guided system smaller than 1.5 mm. This test has successfully caught failures in the entire delivery process. For the monthly QA, diameter of the radiation isocenter was consistently smaller than 0.5 mm and the output has been measured to be within ±1% of baseline. The results of the annual QA, using an ion chamber and EBT3 films, match the beam data of the treatment planning system as well as the data from our in-house Monte Carlo calculation within the tolerance. Additionally, we used EBT3 films and a mouse solid water phantom as tools for verification of dosimetrically complex plans. The maximum dosimetry error observed has been consistently within 2%. With the implemented QA program, the fidelity of overall system delivery was ensured for robust and accurate small animal radiation studies without excess burden on the medical physicists and research team.Tabled 1Abstract 2596; TableProcedureToleranceDailyEnd to end imaging and radiation isocenter coincidence2 mmCBCT imaging quality visual checkBaselineLocalizing lasers1 mmMonthlyOutput constancy2%Isocentricity1 mmGantry position check1 mmAnnualOutput, flatness and symmetry, PDD, output factor1%CBCT imaging quality phantom checkBaseline Open table in a new tab

An Evaluation of the Reach and Effectiveness of a Diabetes Prevention Behaviour Change Program Situated in a Community Site

More than 350 million people are living with prediabetes. Preventing type 2 diabetes (T2D) progression can reduce morbidity, mortality and health-care costs. Interventions can support people with diet and physical activity behaviour changes; however, many interventions are university-based, posing barriers (e.g. accessibility, limited reach and maintenance), which highlight the need for community intervention. Limited research has comprehensively evaluated programs in community contexts. The purpose of this study was to pragmatically examine the reach and effectiveness of a diabetes prevention behaviour change program in the community using the RE-AIM framework. Demographic and outcome data were collected through telephone screening and survey data, and analyzed using descriptive and multivariate analyses. Over 2 years, 9,954 individuals were identified by a medical laboratory as living with prediabetes. Information letters were sent by the laboratory to individuals upon physician approval (N=2,241, 22.5%) as a main form of recruitment. From this, 271 individuals and an additional 160 individuals via other recruitment methods contacted the research team (N=431). Two hundred thirteen adults with prediabetes were enrolled (87.4% Caucasian, 69.7% female; 95% program completion). Analyses of 6-month follow-up data revealed significant maintenance of reductions in weight and waist circumference and improvements in physical function, self-reported physical activity and all-food frequency items except fruit intake (N=121, d=0.21 to 0.68, p <0.05 to 0.001). The program demonstrated diabetes risk-reducing benefits for enrolled individuals. Future work is needed to increase physician referral and participant response rates and to explore program expansion through digitization to reach more individuals at risk of developing T2D.

Memory's reflection of learned information value increases across development.

Prioritizing memory for the information most likely to be useful in the future is critical to learning effectively in our complex world. Previous work has revealed that the ability to strategically encode high-value information may improve gradually over development, as the systems supporting cognitive control processes mature. However, studies of value-directed memory have relied on explicit cues that signal the importance of information, which are rarely present in real-world contexts. Here, we examined whether individuals across age groups could learn the relative frequency of items in their environment and prioritize memory for information associated with higher frequency items, which would ultimately enable them to earn more reward. We found that from childhood to early adulthood, individuals gained the ability to dynamically adjust memory based on the statistics of the environment (Experiment 1). In the absence of any relation between item frequency and the reward that could be earned for encoding related information, the increased exposure to higher frequency items did not facilitate associative memory (Experiment 2). Taken together, results from our two experiments suggest that the use of past experience to prioritize memory for high-value information strengthens with increasing age and is supported by the developing ability to derive explicit knowledge of the structure of the environment from experience. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

SF-Sketch: A Two-Stage Sketch for Data Streams

Sketches are probabilistic data structures designed for recording frequencies of items in a multi-set. They are widely used in various fields, especially for gathering Internet statistics from distributed data streams in network measurements. In a distributed streaming application with high data rates, a sketch in each monitoring node “fills up” very quickly and then its content is transferred to a remote collector responsible for answering queries. Thus, the size of the contents transferred must be kept as small as possible while meeting the desired accuracy requirement. To obtain significantly higher accuracy while keeping the same update and query speed as the best prior sketches, in this article, we propose a new sketch - the Slim-Fat (SF) sketch. The key idea behind the SF-sketch is to maintain two separate sketches: a larger sketch, the Fat-subsketch, and a smaller sketch, the Slim-subsketch. The Fat-subsketch is used for updating and periodically producing the Slim-subsketch, which is then transferred to the remote collector for answering queries quickly and accurately. We also present the error bound as well as an accurate model of the correct rate of the SF-sketch, and verify their correctness through experiments. We implemented and extensively evaluated the SF-sketch along with several prior sketches. Our results show that when the size of our Slim-subsketch and of the widely used Count-Min (CM) sketch are kept the same, our SF-sketch outperforms the CM-sketch by up to 33.1 times in terms of accuracy (when the ratio of the sizes of the Fat-subsketch and the Slim-subsketch is 16:1). We have made all source codes publicly available at Github [“Source code of SF sketches,” [Online]. Available: https://github.com/paper2017/SF-sketch].

Short-term memory capacity and sensitivity to language statistics in dyslexia and among musicians

Poor short-term memory (STM) capacity in individuals with dyslexia (IDDs) and enhanced STM capacity in musicians are well documented, yet their causes are disputed. Previous studies also found poor use of stimuli statistics by IDDs and enhanced use by musicians. We hypothesized that these observations are functionally related, as follows: Enhanced sensitivity to statistics facilitates musicians' benefit from each exposure, and reduced sensitivity to statistics hinders IDDs' benefit. Thus, larger group differences are expected for larger exposure: STM capacity, which is sensitive to item familiarity, will thus be larger among musicians, and smaller among IDDS, particularly for high-frequency items. Testing this hypothesis using syllable span, we found that musicians' advantage and IDDs' difficulty were indeed larger for high-frequency syllables than for low-frequency ones. By contrast, benefits from sequence repetition did not differ between musicians, controls and IDDs, suggesting that online sequence learning is based on a different mechanism. To test this dissociation we recruited, in addition to native Hebrew speakers, native English speakers, matched to the Hebrew-speaking controls. Their spans for high-frequency syllables in Hebrew, which do not have high frequency in English, were small - as expected from reduced exposure to these syllables. Yet, their benefit from sequence repetition was similar to that of the three Hebrew-speaking groups. Taken together, these experiments suggest that different sensitivities to item frequency explain some of the population-related variability in STM tasks. By contrast, benefits from sequence repetition do not depend on item familiarity, and do not differ between groups.

Sport Concussion Assessment Tool Symptom Inventory: Healthy and Acute Postconcussion Symptom Factor Structures.

Previous researchers have examined factor structures for common concussion symptom inventories. However, they failed to discriminate between the acute (<72 hours) and subacute (3 days-3 months) periods after concussion. The Sport Concussion Assessment Tool (SCAT) is an acute assessment that, when compared with other concussion symptom inventories, includes or excludes symptoms that may result in different symptom factors. The primary purpose was to investigate the symptom factor structure of the 22-item SCAT symptom inventory in healthy, uninjured and acutely concussed high school and collegiate athletes. The secondary purpose was to document the frequency of the unique SCAT symptom inventory items. Case series. High school and college. A total of 1334 healthy, uninjured and 200 acutely concussed high school and collegiate athletes. Healthy, uninjured participants completed the SCAT symptom inventory at a single assessment. Participants in the acutely concussed sample completed the SCAT symptom inventory within 72 hours after concussion. Two separate exploratory factor analyses (EFAs) using a principal component analysis and varimax extraction method were conducted. A 3-factor solution accounted for 48.1% of the total variance for the healthy, uninjured sample: cognitive-fatigue (eg, feeling "in a fog" and "don't feel right"), migraine (eg, neck pain and headache), and affective (eg, more emotional and sadness) symptom factors. A 3-factor solution accounted for 55.0% of the variance for the acutely concussed sample: migraine-fatigue (eg, headache and "pressure in the head"), affective (eg, sadness and more emotional), and cognitive-ocular (eg, difficulty remembering and balance problems) symptom factors. The inclusion of unique SCAT symptom inventory items did not alter the symptom factor structure for the healthy, uninjured sample. For the acutely concussed sample, all but 1 unique SCAT symptom inventory item (neck pain) loaded onto a factor.

Sport Concussion Assessment Tool Symptom Inventory: Healthy and Acute Postconcussion Symptom Factor Structures.

Previous researchers have examined factor structures for common concussion symptom inventories. However, they failed to discriminate between the acute (<72 hours) and subacute (3 days-3 months) periods after concussion. The Sport Concussion Assessment Tool (SCAT) is an acute assessment that, when compared with other concussion symptom inventories, includes or excludes symptoms that may result in different symptom factors. The primary purpose was to investigate the symptom factor structure of the 22-item SCAT symptom inventory in healthy, uninjured and acutely concussed high school and collegiate athletes. The secondary purpose was to document the frequency of the unique SCAT symptom inventory items. Case series. High school and college. A total of 1334 healthy, uninjured and 200 acutely concussed high school and collegiate athletes. Healthy, uninjured participants completed the SCAT symptom inventory at a single assessment. Participants in the acutely concussed sample completed the SCAT symptom inventory within 72 hours after concussion. Two separate exploratory factor analyses (EFAs) using a principal component analysis and varimax extraction method were conducted. A 3-factor solution accounted for 48.1% of the total variance for the healthy, uninjured sample: cognitive fatigue (eg, feeling "in a fog" and "don't feel right"), migraine (eg, neck pain and headache), and affective (eg, more emotional and sadness) symptom factors. A 3-factor solution accounted for 55.0% of the variance for the acutely concussed sample: migraine fatigue (eg, headache and "pressure in the head"), affective (eg, sadness and more emotional), and cognitive ocular (eg, difficulty remembering and balance problems) symptom factors. The inclusion of unique SCAT symptom inventory items did not alter the symptom factor structure for the healthy, uninjured sample. For the acute concussed sample, all but 1 unique SCAT symptom inventory item (neck pain) loaded onto a factor.

Relationship of symptom severity and bother in individuals seeking care for lower urinary tract symptoms.

Bother attributed to lower urinary tract symptoms (LUTS) drives care-seeking and treatment aggressiveness. The longitudinal relationship of LUTS severity and bother in a care-seeking cohort, however, is not well understood. We aim to conduct a longitudinal evaluation of LUTS severity and bother and identify characteristics of patients with discordant LUTS bother relative to severity. Men and women with LUTS seeking care at six US tertiary care centers enrolled in the symptoms of lower urinary tract dysfunction research network study. Patients reporting at least one urinary symptom based on the LUTS Tool were prospectively enrolled from June 2015 to January 2017. Correlations were used to assess the relationship between LUTS severity and bother. Discordance scores (ie, the difference between bother and severity) were used to classify patients with high and low bother. Patients were classified as having high or low bother phenotypes if scores were one standard deviation above or below zero, respectively. Repeated measures multinomial logistic regression evaluated characteristics associated with high and low bother phenotypes. LUTS severity and bother were at least moderately correlated for all symptom items and highly correlated for 13 out of 21 items. Correlations were highest for urgency, and lowest for daytime frequency and urinary incontinence. Odds of being in high bother phenotype were lowest at 3 and 12 months (3 months vs baseline odds ratio [OR] = 0.71, 95% confidence ninterval [CI] = 0.54-0.94; 12 months vs baseline OR = 0.66, 95% CI = 0.48-0.91), and highest for those who endorsed all urgency questions (OR = 3.65, 95% CI = 2.17-6.13). Odds of being in the low bother phenotype were lowest for patients who endorsed all urgency items (OR = 0.33, 95% CI = 0.26-0.42), and all frequency items (OR = 0.68, 95% CI = 0.53-0.88). LUTS severity and bother correlate highly and measurement of both in clinical practice is likely redundant. There are patient factors associated with discordance which may justify additional evaluation.

CoopStore

An emerging class of data systems partition their data and precompute approximate summaries (i.e., sketches and samples) for each segment to reduce query costs. They can then aggregate and combine the segment summaries to estimate results without scanning the raw data. However, given limited storage space each summary introduces approximation errors that affect query accuracy. For instance, systems that use existing mergeable summaries cannot reduce query error below the error of an individual precomputed summary. We introduce CoopStore, a query system that optimizes item frequency and quantile summaries for accuracy when aggregating over multiple segments. Compared to conventional mergeable summaries, CoopStore leverages additional memory available for summary construction and aggregation to derive a more precise combined result. This reduces error by up to 25 x over interval aggregations and 4.5 x over data cube aggregations on industrial datasets compared to standard summarization methods, with provable worst-case error guarantees.

Sifting through the weeds: Relationships between cannabis use frequency measures and delay discounting

BackgroundDelay Discounting (DD) relates to more frequent cannabis use, but results are variable, potentially because of variations in whether integrated or single-item measures are used, and whether the timeframe of measures is narrow or broad. Explicating the relationship between DD and cannabis use may result from comparing use indices that vary on these characteristics. MethodsThis online study of current cannabis users (n = 1,800) assessed DD and three cannabis use frequency items: number of days of use in the past month, times used per day, and weekly-monthly use. A fourth index derived with Latent Class Analysis (LCA) integrated days per month and times per day to try to better characterize frequency patterns. Effect sizes reflecting relations between cannabis use frequency indices and DD were compared. ResultsThree frequency classes emerged from the LCA (Low-Moderate-High). DD was significantly associated with times per day (r = 0.11, d = 0.21), days of use (r = 0.09, d = 0.18), and the LCA index (r = 0.06, d = 0.13), but not weekly-monthly use (r = 0.04, d = 0.09). Times per day was more strongly related to DD than LCA classes (p < 0.01) and weekly-monthly use (p < 0.05), but not days of use (p = 0.66). Days of use exhibited a stronger relationship with DD than weekly-monthly use (p < 0.001), but not LCA classes (p = 0.06). ConclusionsCannabis use frequency measures with narrower timeframes may demonstrate stronger positive relationships to DD. The LCA index did not improve the relationship between frequency and DD, potentially because of shared variance between use days and times per day. Specific characteristics of cannabis use frequency may be particularly indicative of excessive DD.

The relationship between negative school gossip and suicide intention in Chinese junior high school students: The mediating effect of academic burnout and gender difference

Previous studies have shown that negative school gossip are associated with suicide intention, but the psychological mechanism of the relationship is still unclear. We tested the relationship among negative school gossip, academic burnout and suicide intent in junior high school students. A sample of 1811 junior high school students (mean age = 13.22 ± 0.97 years) were enrolled in our survey. The adaption of Negative workplace gossip scale, School burnout inventory, and items of suicidal ideation and frequency of suicide attempts were used to test negative school gossip, academic burnout, and suicide intention. Results showed that negative school gossip positively correlated with suicide intention, and it increased participants’ suicide intention via increasing academic burnout. The results of this study suggest that academic burnout played a partial mediating role between negative school gossip and suicide intention in Chinese junior high school students, and the relationship between academic burnout and adolescents' suicide intention was moderated by gender. The present study revealed the harm of negative school gossip to the development of adolescents and provided empirical supports for the prevention and intervention of adolescent suicide. The limitations and implications were discussed.

Dietary contribution to body burden of bisphenol A and bisphenol S among mother-children pairs

Due to the health concerns over bisphenol A (BPA), bisphenol S (BPS) has been used as an alternative in greater quantity. Diet is considered as the major source of exposure to bisphenols; however, its contribution to the total body burden has not been fully understood. In the present study, a 3-day dietary intervention was carried out for a group of mother and child(ren) pairs (37 families, 93 subjects), and contribution of the dietary factors to body burden of both bisphenols was investigated. During the intervention, the participants were asked to refrain from the foods in cans and plastic containers, fast foods, and delivery foods. Urinary levels of BPA and BPS were measured before, during, and after the intervention. In addition, the questionnaire survey was conducted for potential contributors to BPA and BPS exposure. Following the intervention, urinary levels of BPA and BPS of the mothers decreased on average by 53.1% (95% CI: −30.0, −68.6), and 63.9% (95% CI: −37.1, −79.3), respectively. Among the children, urinary BPA concentrations decreased by 47.5% (95% CI: −25.6, −62.9) by the intervention. However, BPS levels in urine did not change in the children. Interestingly, urinary BPS concentrations of the children measured during the non-intervention period were greater than those of the mothers in the same period. Consumption frequencies of several food items, e.g., canned foods, take-out drinks, or fast foods, were significantly correlated with elevated levels of urinary BPA or BPS concentrations. The results of this intervention study emphasize the importance of dietary contribution to BPA exposure among the mothers and children. Our findings also show that non-dietary sources could be a more important contributor for certain people, especially to BPS exposure among children. Further studies are warranted to identify the sources of BPS exposure among children.

Teachers Perspectives and Practices of Assessment in Health Education in Primary School

Health Education is one of the core subjects studied in primary and secondary schools in Malaysia. However, assessment through Health Education is not widely used among teachers as there is no standardized assessment to test the level of students understanding. This study was conducted to determine the perspectives and practices of assessment among Health Education teachers. 40 Health Education teachers from 5 schools in Bukit Mertajam, Pulau Pinang were involved in this study. A set of questionnaires were used as a research instrument containing 37 items using Likert scale. The reliability value of the instrument is ? = 0.80. Data were analysed using Statistical Package for the Social Science (SPSS) software version 23.0. Results showed all the teachers are only at ‘Agree’ and ‘Undecided levels for all the perspectives items about assessment that have been given. The component item for types and forms of assessment component showed the highest percentage of 37.5% and 20% teachers are at ‘agree’ level with mean value of 3.30. Meanwhile, as for the frequency of assessment practices results showed all the items were rated only at ‘Sometimes’ and ‘Frequently’. No significant difference was found in the mean item level between male and female teacher for both agreement and frequency item. The overall mean of assessment items is at a ‘agree’ and ‘sometimes’ level of 3.45 and 3.74 respectively. Results demonstrate the effectiveness of assessment activities involvement teachers in developing their knowledge in classroom assessment.

Evaluating the quality of multiple-choice questions in a NAPLEX preparation book

Introduction: There is a plethora of preparatory books and guides available to help study for the North American Pharmacist Licensure Examination (NAPLEX). However, the quality of questions included has not been scrutinized. Our objective was to evaluate the quality of multiple-choice questions (MCQs) construction in a commonly used NAPLEX preparatory book.Methods: Five students and two faculty members reviewed MCQs from the RxPrep 2018 edition course book. Item structure and utilization of case-based questions were evaluated using best practices for item construction. Frequency of item writing flaws (IWF) and utilization of cases for case-based questions was identified.Results: A total of 298 questions were reviewed. Twenty-seven (9.1%) questions met all best practices for item construction. Flawed questions contained an average of 2.53 IWF per MCQ. The most commonly identified best practice violations were answer choices containing differing length and verb tense (21%) and question stems containing too little or too much information necessary to eliminate distractors (16.6%). Of the case-based questions, the majority (61.9%) did not require utilization of the provided case.Conclusions: This pilot analysis identified that a majority of MCQs in one NAPLEX preparatory source contained IWF. These results align with previous evaluations of test-banks in published books outside of pharmacy. Further evaluation of other preparatory materials, to expand on the findings from this pilot analysis, are needed to evaluate the pervasiveness of IWF in preparatory materials and the effect of flawed questions on utility of study materials.

METHOD OF IDENTIFICATION BOT PROFILES BASED ON NEURAL NETWORKS IN RECOMMENDATION SYSTEMS

The subject matter of the article is the process of increased the information security of recommendation systems. The goal of this work is to develop a method of identification bot profiles in recommendation systems. In this work, the basic models of information attacks by the profile-injection method on recommendation systems were researched, the method of identification bot profiles in recommendation systems using the multilayer feedforward neural network was developed and the experiments to test the quality of its work were conducted. The developed method is to identify bot profiles that attempt to change item ratings in a recommendation system in order to increase the occurrence frequency of target items in recommendation lists to all authentic users, or to certain segments of authentic users. When removing bot profiles' data from the database of the recommendation system before generating recommendation lists, the accuracy of the system and the correctness of recommendations are significantly increased, and authentic users get protection from information attacks. Random, Average and Popular attacks were used to model the attacks on a recommendation system. To identify bots, their ratings for system items were analyzed. The experiments have shown that the neural network that analyzes only the numbers of different ratings in a profile, detects bot profiles with high accuracy, that use Random attack regardless of the number of target items for each bot. At the same time, the developed neural network can detect bots that use Average or Popular attacks only when they have several target items. Also, the results of the experiments show that type I errors, when the system identifies authentic users as bots, is very rarely appear in the developed method. To improve the accuracy of the neural network, there can add to analysis also other data of user profiles, such as the timestamp of each rating and as segments of items, which was rated.

Lexical frequency affects functional activation and accuracy in picture naming among older and younger adults.

As individuals age, they experience increased difficulties producing speech, especially with infrequent words. Older adults report that word retrieval difficulties frequently occur and are highly frustrating. However, little is known about how age affects the neural basis of language production. Moreover, age-related increases in brain activation are often observed, yet there is disagreement about whether such increases represent a form of neural compensation or dedifferentiation. We used functional magnetic resonance imaging (fMRI) to determine if there are age-related differences in functional activation during picture naming and whether such differences are consistent with a compensatory, dedifferentiation, or hybrid account that factors in difficulty. Healthy younger and older adults performed a picture-naming task with stimuli that varied in lexical frequency-our proxy for difficulty. Both younger and older adults were sensitive to lexical frequency behaviorally and neurally. However, younger adults performed more accurately overall and engaged both language (bilateral insula and temporal pole) and cognitive control (bilateral superior frontal gyri and left cingulate) regions to a greater extent than older adults when processing lower frequency items. In both groups, poorer performance was associated with increases in functional activation consistent with dedifferentiation. Moreover, there were age-related differences in the strength of these correlations, with better performing younger adults modulating the bilateral insula and temporal pole and better performing older adults modulating bilateral frontal pole and precuneus. Overall, these findings highlight the influence of task difficulty on fMRI activation in older adults and suggest that as task difficulty increases, older and younger adults rely on different neural resources. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Measurement properties of the Patient-Reported Outcomes Information System (PROMIS® ) Itch Questionnaire: itch severity assessments in adults with atopic dermatitis.

Little is known about the validity of numeric rating scales (NRS) and verbal rating scales (VRS) for itch and itch frequency for assessing itch severity in atopic dermatitis (AD). We evaluated the Patient-Reported Outcomes Information System (PROMIS® ) Itch Questionnaire (PIQ) - itch severity assessment, including multiple NRS,VRS and frequency of itch assessments, in adults with AD and compared their performance. Self-administered questionnaires and skin examinations were performed in 410 patients with AD (aged 18-90 years) in a dermatology practice setting. PIQ NRS,VRS and frequency of itch had good content validity, strong correlations with one another (Spearman correlations P < 0·001) and weak-to-moderate correlations with patient-oriented eczema measure (POEM), Eczema Area and Severity Index (EASI), objective SCORing AD (SCORAD) and Dermatology Life Quality Index (DLQI) (P < 0·001) and very good discriminant validity. Changes from baseline in NRS,VRS and frequency of itch were moderately to strongly correlated with one another, and weakly to moderately correlated with other patient-reported (POEM,SCORAD itch, DLQI) and clinician-reported outcomes (EASI, objective SCORAD). NRS and VRS worst itch and average itch showed moderate-to-good test-retest reliability. There were no floor or ceiling effects for NRS or VRS itch, but there were ceiling effects for itch frequency. Each assessment was completed in < 1 min by all patients. NRS,VRS and frequency of itch items from PIQ - itch severity showed good content and construct validity, reliability, and/or responsiveness in adults with AD, and were feasible for use in clinical trials and practice. What is already known about this topic? Numeric rating scales (NRS), verbal rating scales (VRS) and frequency of itch have been used to assess the burden of itch. However, there have been limited results demonstrating their validity, responsiveness, interpretability and feasibility, particularly in atopic dermatitis (AD). What does this study add? This study demonstrated that NRS, VRS and frequency of itch items from the Patient-Reported Outcomes Information System (PROMIS® ) Itch Questionnaire (PIQ) - itch severity assessments had good construct validity, responsiveness, reliability and feasibility in the assessment of adult AD. PIQ NRS, VRS and frequency of itch all appear to have sufficient validity, reliability and feasibility for use as assessments of itch in adults with AD in clinical practice and trials. What are the clinical implications of this work? PIQ NRS and VRS are all simple, valid, reliable and feasible for use in clinical practice and trials to assess itch in adults with AD. Linked Comment: Oosterhaven. Br J Dermatol 2020; 183:802-803.

FOOD HABITS OF COYOTES (CANIS LATRANS) IN THE VALLES CALDERA NATIONAL PRESERVE, NEW MEXICO

Wildlife managers needed to understand coyote (Canis latrans) ecology in order to develop management plans on the nascent Valles Caldera National Preserve in northern New Mexico. Managers concerned about low elk (Cervus elaphus) recruitment had observed an increase in sightings of coyotes and observations of coyote predation on elk calves. Our objective was to identify and quantify coyote diet, and assess the temporal variation in coyote diet on the Valles Caldera National Preserve, particularly as related to elk calf consumption. We examined coyote food habits using 1,385 scats analyzed monthly from May 2005 to November 2008. The most frequent taxa were rodents (predominantly voles from the genus Microtus, and northern pocket gophers, Thomomys talpoides), elk, insects from the orders Orthoptera (grasshoppers and crickets) and Coleoptera (beetles), mountain cottontail rabbit (Sylvilagus nuttallii), and plant material (mainly grass). We detected rodent and elk in scats during all months of the study and were each present in 54% of scats overall. We identified elk remains in 43% of spring scats, 72% of winter scats, and 56% of fall scats. During summers, we could distinguish calf from adult elk hair: 8% of summer the scats contained adult elk hair and 39% contained calf elk hair. The frequency of prey items varied significantly over most seasons and years, with notable exceptions being that elk did not vary among summers and winters, and rabbits were a consistent diet item through all seasons. The high frequency of elk in the coyote diet bears further study on the density of elk calves, the vulnerability of elk to predation, the nutritional impacts from the quality of forage available to elk, and the role of hunting and other mammalian predators in providing carcasses.