SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Chi-square distribution

351

Using mixed design analysis of variance (ANOVA), this paper investigates the effects of a subtle simulated increase in adiposity on women’s employment chances in the service sector. Employing a unique simulation of altering individuals' BMIs and the literature on “aesthetic labour”, the study suggests that, especially for women, being heavier, but still within a healthy BMI, deleteriously impacts on hireability ratings. The paper explores the gendered dimension of this prejudice by asking whether female employees at the upper end of a healthy BMI range are likely to be viewed more negatively than their overtly overweight male counterparts. The paper concludes by considering the implications of these findings.

Concepts: Male, Female, Variance, Gender, Normal distribution, Woman, Analysis of variance, Chi-square distribution

25

To evaluate utricular and saccular function during the acute and resolved phases of BPPV, ocular and cervical vestibular evoked myogenic potentials (VEMPs) were studied in 112 patients with BPPV and 50 normal controls in a referral-based University Hospital. Ocular (oVEMPs) and cervical VEMPs (cVEMPs) were induced using air-conducted sound (1000Hz tone burst, 100dB normal hearing level) at the time of initial diagnosis and 2months after successful repositioning in patients with BPPV, and the results were compared with those of the controls. Abnormalities of cVEMPs and oVEMPs in patients with BPPV were prevalent and significantly higher compare to the healthy control group (p<0.01 in each VEMP by chi-square test). In the patient group, difference between the proportions of abnormal responses of cVEMP and oVEMP was not significant in both affected (p=0.37, chi-squared test) and non-affected (p=1.00) ears. The abnormalities were more likely reduced or absent responses rather than delayed ones; reduced or absent responses are 17.6% in cVEMPs (p=0.04, chi-square) and 21.6% in oVEMPs (p<0.01). The non-affected ear in the BPPV group also showed significantly higher abnormalities of cVEMP and oVEMP when compared to the control group. The follow-up VEMPs after repositioning maneuvers were not significantly different compared to the initial values from both stimulated affected and non-affected ears. Although most patients had unilateral BPPV, bilateral otolithic dysfunction was often shown by persistently reduced or absent cervical and ocular VEMPs, suggesting that BPPV may be caused by significant bilateral damage to the otolith organs.

Concepts: Auditory system, Vestibular evoked myogenic potential, Superior canal dehiscence, Ear, Chi-square test, Chi-square distribution, Pearson's chi-square test, Benign paroxysmal positional vertigo

25

The clam Meretrix meretrix is a commercially important mollusc species in the coastal areas of South and Southeast Asia. In the present study, large-scale SNPs were genotyped by the Multiplex SNaPshot genotyping method among the stocks of M. meretrix with different Vibrio spp. infection resistance profile. Firstly, the AUTOSNP software was applied to mine SNPs from M. meretrix transcriptome, and 323 SNP loci (including 120 indels) located on 64 contigs were selected based on Uniprot-GO associations. Then, 38 polymorphic SNP loci located on 15 contigs were genotyped successfully in the clam stocks with different resistance to Vibrio parahaemolyticus infection (11-R and 11-S groups). Pearson’s Chi-square test was applied to compare the allele and genotype frequency distributions of the SNPs between the different stocks, and seven SNP markers located on three contigs were found to be associated with V. parahaemolyticus infection resistance trait. Haplotype-association analysis showed that six haplotypes had significantly different frequency distributions in 11-S and 11-R (P < 0.05). With selective genotyping between 09-R and 09-C populations, which had different resistance to Vibrio harveyi infection, four out of the seven selected SNPs had significantly different distributions (P < 0.05) and therefore they were considered to be associated with Vibrio spp. infection resistance. Sequence alignments and annotations indicated that the contigs containing the associated SNPs had high similarity to the immune related genes. All these results would be useful for the future marker-assisted selection of M. meretrix strains with high Vibrio spp. infection resistance.

Concepts: Immune system, Gene, Genetics, Chi-square test, Chi-square distribution, Pearson's chi-square test, Vibrio, Vibrio parahaemolyticus

24

Transdisciplinary (TD) approaches are increasingly used to address complex public health problems such as childhood obesity. Compared to traditional grant-funded scientific projects among established scientists, those designed around a TD, team-based approach yielded greater publication output after three to five years. However, little is known about how a TD focus throughout graduate school training may affect students' publication-related productivity, impact, and collaboration. The objective of this study was to compare the publication patterns of students in traditional versus TD doctoral training programs. Productivity, impact, and collaboration of peer-reviewed publications were compared between traditional (n = 25) and TD (n = 11) students during the first five years of the TD program. Statistical differences were determined by t-test or chi square test at p < 0.05. The publication rate for TD students was 5.2 ± 10.1 (n = 56) compared to 3.6 ± 4.5 per traditional student (n = 82). Publication impact indicators were significantly higher for TD students vs. traditional students: 5.7 times more citations in Google Scholar, 6.1 times more citations in Scopus, 1.3 times higher journal impact factors, and a 1.4 times higher journal h-index. Collaboration indicators showed that publications by TD students had significantly more co-authors (1.3 times), and significantly more disciplines represented among co-authors (1.3 times), but not significantly more organizations represented per publication compared to traditional students. In conclusion, compared to doctoral students in traditional programs, TD students published works that were accepted into higher impact journals, were more frequently cited, and had more cross-disciplinary collaborations.

Concepts: Academic publishing, Impact factor, Publishing, Chi-square distribution, Newspaper, Publication, Institute for Scientific Information, H-index

8

Smartphones are now owned by most young adults in many countries. Installed applications regularly update while the phone is in standby. If it is kept near the body, this can lead to considerably higher exposure to radiofrequency electromagnetic radiation than occurred without internet access. Very little is known about current smartphone carrying habits of young women. This survey used an online questionnaire to ask about smartphone location under several circumstances to inform the power calculation for a women’s health study. They were also asked about risk perceptions. Data was analysed using Pearson chi square. Three age categories were made: 15-20, 21-30, 31-40. Smartphones were generally kept on standby (96% by day, 83% at night). Of all participants, in the last week the most common locations of the phone when not in use or during passive use was off-body (86%), in the hand (58%), a skirt/trouser pocket (57%), or against the breast (15%). Pocket and near-the-breast storage were significant by age (χ215.04, p = 0.001 and χ210.96, p = 0.04, respectively), both positively influenced by the youngest group. The same influence lay in the association between holding the phone (χ211.082, p = 0.004) and pocket-storage (χ219.971, p<0.001) during passive use. For calls, 36.5% solely used the phone against the head. More than half kept the phone 20-50 cms from their head at night (53%), while 13% kept it closer than 20 cms. Many (36%) thought RF-EMR exposure was related to health problems while 16% did not. There was no relationship between thinking RF-EMR exposure causes health problems in general and carrying the phone against the upper or lower body (p = 0.69 and p = 0.212, respectively). However, calls with the phone against the head were positively related to perception of health risk (χ2 6.695, p = 0.035). Our findings can be used in the power calculation for a case-control study.

Concepts: Electromagnetic radiation, Electromagnetic spectrum, Sense, Mind, Mobile phone, Chi-square test, Chi-square distribution, Pearson's chi-square test

6

BACKGROUND: The increasing numbers of colonias along the U.S.-Mexico border are characterized by disproportionately poor families of Mexican-origin, limited access to resources and health services, and heightened risk for obesity and diabetes. Despite consistent evidence supporting physical activity (PA) in prevention of chronic diseases, many individuals of Mexican-origin, including children, fail to meet PA recommendations. Environmental influences on PA, founded in ecological and social cognitive perspectives, have not been examined among children living in colonias. The purpose of this study was to identify and better understand (1) household and neighborhood environmental PA resources/supports, (2) perceived barriers to engaging in PA, and (3) PA offerings, locations, and transportation characteristics for Mexican-origin children living in colonias. METHODS: Data for this study were collected by promotora-researchers (indigenous community health workers trained in research methods) using face-to-face interviews conducted in Spanish. The sample consists of 94 mother-child dyads from Texas border colonias in Hidalgo County. Interviews included questionnaire items addressing PA barriers, household and neighborhood environmental support assessments conducted with each dyad, and open-ended questions that were coded to identify availability and locations of PA opportunities and transportation options. Descriptive statistics were calculated and differences between genders, birth countries, and BMI categories of children were determined using chi-square tests. RESULTS: All children were of Mexican-origin. The most frequently reported barriers were unleashed dogs in the street, heat, bad weather, traffic, no streetlights, and no place like a park to exercise. Prominent locations for current PA included schools, home, and parks. Common PA options for children were exercise equipment, running, playing, and sports. Environmental assessments identified exercise equipment (bicycles/tricycles, balls, etc….), paved/good streets, yard/patio space, and social norms as the most frequent household or neighborhood resources within these colonias. Differences in PA barriers, options, and environmental resources for genders, birth countries, and BMI categories were detected. CONCLUSIONS: This study suggests that PA environmental resources, barriers, and opportunities for colonias children are similar to previous studies and distinctively unique. As expected, built resources in these communities are limited and barriers exist; however, knowledge of PA opportunities and available PA resources within colonias households and neighborhoods offers insight to help guide future research, policy, and PA initiatives.

Concepts: Family, Obesity, Physical exercise, Sociology, Body mass index, Dyadic, Chi-square test, Chi-square distribution

4

Many journals, including the Journal of Neurochemistry, enable authors to list peer reviewers as “preferred” or “opposed” suggestions to the editor. At the Journal of Neurochemistry, the handling editor (HE) may follow recommendations or select non-author-suggested reviewers (non-ASRs). We investigated whether selection of author-suggested reviewers (ASRs) influenced decisions on a paper, and whether differences might be related to a reviewers', editor’s or manuscript’s geographical location. In this retrospective analysis, we compared original research articles submitted to the Journal of Neurochemistry from 2013 through 2016, that were either reviewed exclusively by non-ASRs, by at least one ASR, by at least one reviewer marked by the author as “opposed”, or none. Manuscript outcome, reviewer rating of manuscript quality, rating of the reviewers' performance by the editor (R-score), time to review, and the country of the editor, reviewers and manuscript author were analyzed using non-parametric rank-based comparisons, chi-square (x2 ) analysis, multivariate linear regression, one-way analysis of variance, and inter-rater reliability determination. Original research articles that had been reviewed by at least one ASR stood a higher chance of being accepted (525/1006 = 52%) than papers that had been reviewed by non-ASRs only (579/1800 = 32%). An article was 2.4 times more likely to be accepted than rejected by an ASR compared to a non-ASR (Pearson’s x2 (1) = 181.3, p<0.05). At decision, the editor did not simply follow the reviewers' recommendation but had a balancing role: Rates of recommendation from reviewers for rejection were 11.2% (139/1241) with ASRs vs. 29.0% (1379/4755) with non-ASRs (this is a ratio of 0.39 where 1 means no difference between rejection rates for both groups), whereas the proportion of final decisions to reject was 24.7% (248/1006) vs. 45.7% (822/1800) (a ratio of 0.54, considerably closer to 1). Recommendations by non-ASRs were more favorable for manuscripts from USA/Canada and Europe than for Asia/Pacific or Other countries. ASRs judged North American manuscripts most favorably, and judged papers generally more positively (mean: 2.54 on a 1-5 scale) than did non-ASRs (mean: 3.16) reviewers, whereas time for review (13.28 vs. 13.20 days) did not differ significantly between these groups. We also found that editors preferably assigned reviewers from their own geographical region, but there was no tendency for reviewers to judge papers from their own region more favorably. Our findings strongly confirm a bias towards lower rejection rates when ASRs assess a paper, which led to the decision to abandon the option to recommend reviewers at the Journal of Neurochemistry. This article is protected by copyright. All rights reserved.

Concepts: Linear regression, Variance, Geography, Review, Analysis of variance, All rights reserved, Chi-square distribution, Copyright

3

The low-molecular-weight fraction of 5% human serum albumin (LMWF-5A) is being developed to treat the signs and symptoms of severe osteoarthritis of the knee. This study was a post hoc pooled analysis of 3 randomized placebo-controlled trials of a single intra-articular injection of LMWF-5A, focusing on the subset of patients with severe osteoarthritis of the knee (Kellgren-Lawrence grade 4). Patients were randomized 1:1 to receive a single 4-mL intra-articular knee injection of either LMWF-5A or saline. Safety was assessed as the incidence and severity of adverse events. Efficacy was assessed as the change from baseline to week 12 on the Western Ontario and McMaster Universities Osteoarthritis Index pain (primary outcome), stiffness, and physical function subscores and on patient global assessment scores and was presented as the least squares mean difference and 95% confidence interval. The proportion of responders was defined with the Outcome Measures in Rheumatology-Osteoarthritis Research Society International criteria for scenario D and examined with Pearson’s chi-square test. For 417 patients with severe osteoarthritis of the knee, treatment with LMWF-5A resulted in a significant decrease in pain at 12 weeks compared with saline (mean difference, -0.19; 95% confidence interval, -0.34 to -0.04; P=.016), with improvements in function (mean difference, -0.15; 95% confidence interval, -0.31 to 0.01) and patient global assessment (mean difference, -0.30; 95% confidence interval, -0.49 to -0.12) and higher responder rates (64.25% vs 50.90%, P=.006). No drug-related serious adverse events and no deaths occurred, and the incidence and severity of adverse events were similar across treatment groups. This pooled analysis supports the use of LMWF-5A as a safe therapeutic agent for relief of the signs and symptoms of severe osteoarthritis of the knee. [Orthopedics. 201x; xx(x):xx-xx.].

Concepts: Osteoarthritis, Knee, Joint, Normal distribution, Chi-square test, Chi-square distribution, Pearson's chi-square test

2

Next generation sequencing (NGS) technology is a widely accepted tool used by microbial ecologists to explore complex microbial communities in different ecosystems. As new NGS platforms continue to become available, it becomes imperative to compare data obtained from different platforms and analyze their effect on microbial community structure. In the present study, we compared sequencing data from both the 454 and Ion Torrent (PGM) platforms on the same DNA samples obtained from the rumen of dairy cows during their transition period. Despite the substantial difference in the number of reads, error rate and length of reads among both platforms, we identified similar community composition between the two data sets. Procrustes analysis revealed similar correlations (M (2) = 0.319; P = 0.001) in the microbial community composition between the two platforms. Both platforms revealed the abundance of the same bacterial phyla which were Bacteroidetes and Firmicutes; however, PGM recovered an additional four phyla. Comparisons made at the genus level by each platforms revealed differences in only a few genera such as Prevotella, Ruminococcus, Succiniclasticum and Treponema (p < 0.05; chi square test). Collectively, we conclude that the output generated from PGM and 454 yielded concurrent results, provided stringent bioinformatics pipelines are employed.

Concepts: Comparison, Bacteria, Microbiology, Milk, Difference, Genus, Comparisons, Chi-square distribution

2

This study examines whether use of alcohol at first coitus is associated with increased sexual risk for young women. First coitus is the focus of the investigation because it is a memorable, formative experience that has implications for subsequent sexual health. A community sample of young women ages 18-19 years (N = 227) completed retrospective interviews. Characteristics and perceptions of the first coital event were examined using chi squares and one-way multivariate analysis of variance (MANOVA) to determine if there were differences based on alcohol-involvement. Alcohol-involved first coitus events occurred in social settings with risky partners, were rated less positively, and were non-consensual relative to those that did not involve alcohol. Alcohol use was not related to condom use. Alcohol-involvement was associated with subsequent pairing of alcohol with sex and incapacitated rape. Adolescent alcohol use occurs in contexts that increases young women’s sexual risk through exposure to risky partners.

Concepts: Birth control, Sexual intercourse, Risk, Human sexual behavior, Analysis of variance, Condom, Rape, Chi-square distribution