2,900 research outputs found
Errors in statistical analysis and questionable randomization lead to unreliable conclusions
Dear Editor,We read with interest the paper, “The effect of food service system modifications on staff body mass index in an industrial organization”[1]. We noticed several substantial issues with data and calculations, calling into question the randomized nature of the study and validity of analyses.The distribution of baseline weight was significantly differentbetween groups (p-value = “0.00”). We replicated the test using reported means and standard deviations (SDs) andobtained a p-value of approximately 1.9*10-17. It is extraordinarily unlikely that any variable would be that different between two groups if allocation was truly random. Even it was truly random, the stated method of “the samples were randomly divided into two groups”[1] does not describe the “method used to generate the random allocation sequence” and the “type of randomization; details of any restriction (such as blocking and block size)” details specified by Consolidated Standards of Reporting Trials (CONSORT)[2].Given the large difference in baseline weights, it is unusual that the difference in baseline body mass index (BMI) between groups is not more significant (p=0.032), raising the question of what the groups’ distributions of height were. Both groups have 30 males (58.8%), so sex differences are unlikely to explain this discrepancy. Height was not explicitly reported, but it was possible to estimate height utilizing geometric means from body weight and BMI[3,4]. We calculated the baseline control group geometric mean as 2.04 cm taller than the test group. These calculations also suggest the control group shrunk by 1.26 cm while the test group grew by 1.52 cm over the study. Neither change is explained by rounding error nor seems plausible for adult subjects over 40 days.Because there were no SDs of the change scores reported, we were unable to replicate the reported p-value (0.318) for the between-group test of weight change exactly. However, we were able to consider the pre and post-intervention SDs and calculate possible SDs of within-group change scores for a range of pre-post correlations. The largest p-value possible was 0.1282, calculated when each group had perfect negative pre-post correlation (correlation=-1), which is unlikely. If there was no or a positive correlation, the p-value would be much smaller (p=0.0449 when correlation=0 for each group) and plausibly indicates a significant difference between groups. Therefore, although the published results are impossible the correct analysis could make the intervention appear more effective than reported.The results section describes an initial sample size of 116 with 14 dropping out (p. 115). The tables report the remaining sample size to be 102, but the body of the text reports 101 subjects remained until study completion. It is unclear which values were correct; this lack of clarity also fails CONSORT guidelines[2].Considering that the reported findings are essentially impossible given the stated study design, we encourage the authors to explain the treatment allocationand make the raw data available, or the journal to act according to the Committee on Publication Ethics[5] in situations where findings are unreliabl
Professional practices, training, and funding mechanisms: A survey of pediatric primary care psychologists
The integration of mental health services in primary care settings has expanded rapidly in recent years with psychologists being at the forefront of efforts to promote healthy behaviors, reduce disease, and care for behavioral, emotional, and developmental needs to promote overall health and well-being for children and families (Asarnow, Kolko, Miranda,&Kazak, 2017; Stancin& Perrin, 2014). While there are many psychologists working in pediatric primary care (PPC), little is known about the specific activities that these psychologists engage in, the training they receive, or funding mechanisms that support their work. This study sought to address this gap in the literature through a survey of psychologists working in PPC. An anonymous online survey was disseminated to members of professional organizations and listservs who were identified as having interest in PPC. Psychologists (N-65) currently practicing in PPC completed the survey by reporting on clinical roles and practices, professional training, practice settings, and funding supports in PPC settings. Results indicate that psychologists assume a number of roles in PPC including providing individual and family therapy, conducting screenings for child mental health concerns, and providing consultation to medical colleagues. Many psychologists also provide supervision and offer educational opportunities for those in related fields, such as medicine and social work. Engagement in research activities was identified as a secondary activity. It was reported that a number of clinical activities were not billed for on a regular basis. Additional areas of research will be discussed along with implications for clinical services in PPC.. © 2017 American Psychological Association
Avian oncogenesis induced by lymphoproliferative disease virus: a neglected or emerging retroviral pathogen?
Lymphoproliferative disease virus (LPDV) is an exogenous oncogenic retrovirus that induces lymphoid tumors in some galliform species of birds. Historically, outbreaks of LPDV have been reported from Europe and Israel. Although the virus has previously never been detected in North America, herein we describe the widespread distribution, genetic diversity, pathogenesis, and evolution of LPDV in the United States. Characterization of the provirus genome of the index LPDV case from North America demonstrated an 88% nucleotide identity to the Israeli prototype strain. Although phylogenetic analysis indicated that the majority of viruses fell into a single North American lineage, a small subset of viruses from South Carolina were most closely related to the Israeli prototype. These results suggest that LPDV was transferred between continents to initiate outbreaks of disease. However, the direction (New World to Old World or vice versa), mechanism, and time frame of the transcontinental spread currently remain unknown
Most \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e MicroRNAs are Individually Not Essential for Development or Viability
MicroRNAs (miRNAs), a large class of short noncoding RNAs found in many plants and animals, often act to post-transcriptionally inhibit gene expression. We report the generation of deletion mutations in 87 miRNA genes in Caenorhabditis elegans, expanding the number of mutated miRNA genes to 95, or 83% of known C. elegans miRNAs. We find that the majority of miRNAs are not essential for the viability or development of C. elegans, and mutations in most miRNA genes do not result in grossly abnormal phenotypes. These observations are consistent with the hypothesis that there is significant functional redundancy among miRNAs or among gene pathways regulated by miRNAs. This study represents the first comprehensive genetic analysis of miRNA function in any organism and provides a unique, permanent resource for the systematic study of miRNAs
West Nile Virus Viremia in Wild Rock Pigeons
Feral rock pigeons were screened for neutralizing antibodies to West Nile virus (WNV) during late winter/spring and summer of 2002 and 2003. Additionally, virus isolation from serum was attempted from 269 birds collected during peak transmission periods. The observed viremia levels and seroprevalence indicate that this species could be involved in amplifying WNV in urban settings
The influence of harasser-victim dyads and observer sex on perceived sexual harassment
This study investigated how sex of an observer, harasser, and victim may influence perceptions of sexual harassment (SH). We hypothesized that (1) women would perceive more sexual harassment than men, across all study conditions, (2) the most sexual harassment would be perceived in male harasser-female victim vignettes, (3) the least sexual harassment would be perceived in female harasser-male victim vignettes, (4) Men in the no definition control group would report the most perceived SH, those in the MacKinnon (more inclusive) definition condition would perceive slightly less SH than those in the control condition, but more than those in the EEOC. Four hundred and thirteen participants, 186 males and 227 females, age 18-25, were recruited via MTURK. Participants were invited to complete an electronic questionnaire asking them to rate the extent to which different vignettes qualified as SH. The vignettes differed in the level of their SH, from superficial, verbal comments to derogatory attitudes. Univariate ANOVAs indicate that that female participants were more likely to perceive SH than male participants across the vignettes. Additionally, more SH was perceived when the harasser was male and when the victim was female. Interactions were found between harasser sex and victim sex, between harasser sex, victim sex, and participant sex, and between definition condition, participant sex, and victim sex. The results help to further understanding of how individuals think of and perceive SH in a variety of work settings and situations. Applications range from legal proceedings to SH training in the workplac
Observations on the diets of an anuran and eight lizard taxa from Sonora, Chihuahua, and Coahuila, Mexico, with some notes on clutch sizes
Foresight and trade-off analyses : tools for science strategy development in agriculture and food systems research
Foresight and trade-off analyses offer organizations such as CGIAR an opportunity to better prepare for alternative futures through adaptive research strategy and management. This essay introduces a set of papers that explore foresight and trade-off analyses within the context of the major reforms now occurring in the CGIAR. We tease out lessons not only for One CGIAR, but also for international development research organizations more broadly.Publisher PDFPeer reviewe
Sustained adherence to a Mediterranean diet and physical activity on all-cause mortality in the Melbourne Collaborative Cohort Study: application of the g-formula.
BACKGROUND: Adherence to a traditional Mediterranean diet has been associated with lower mortality and cardiovascular disease risk. The relative importance of diet compared to other lifestyle factors and effects of dietary patterns over time remains unknown. METHODS: We used the parametric G-formula to account for time-dependent confounding, in order to assess the relative importance of diet compared to other lifestyle factors and effects of dietary patterns over time. We included healthy Melbourne Collaborative Cohort Study participants attending a visit during 1995-1999. Questionnaires assessed diet and physical activity at each of three study waves. Deaths were identified by linkage to national registries. We estimated mortality risk over approximately 14 years (1995-2011). RESULTS: Of 22,213 participants, 2163 (9.7%) died during 13.6 years median follow-up. Sustained high physical activity and adherence to a Mediterranean-style diet resulted in an estimated reduction in all-cause mortality of 1.82 per 100 people (95% confidence interval (CI): 0.03, 3.6). The population attributable fraction was 13% (95% CI: 4, 23%) for sustained high physical activity, 7% (95% CI: - 3, 17%) for sustained adherence to a Mediterranean-style diet and 18% (95% CI: 0, 36%) for their combination. CONCLUSIONS: A small reduction in mortality may be achieved by sustained elevated physical activity levels in healthy middle-aged adults, but there may be comparatively little gain from increasing adherence to a Mediterranean-style diet
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