Tag: statistics

PLoS One. 2022 Jun 9;17(6):e0268914. doi: 10.1371/journal.pone.0268914. eCollection 2022.

ABSTRACT

White sharks (Carcharodon carcharias) are the largest shark species to display regional endothermy. This capability likely facilitates exploitation of resources beyond thermal tolerance thresholds of potential sympatric competitors as well as sustained elevated swim speeds, but results in increased metabolic costs of adults, which has been documented in different studies. Little, however, is known of the metabolic requirements in free-swimming juveniles of the species, due to their large size at birth and challenges in measuring their oxygen consumption rates in captivity. We used trilateration of positional data from high resolution acoustic-telemetry to derive swim speeds from speed-over-ground calculations for eighteen free-swimming individual juvenile white sharks, and subsequently estimate associated mass-specific oxygen consumption rates as a proxy for field routine metabolic rates. Resulting estimates of mass-specific field routine metabolic rates (368 mg O2 kg-1 h-1 ± 27 mg O2 kg-1 h-1 [mean ± S.D.]) are markedly lower than those reported in sub-adult and adult white sharks by previous studies. We argue that median cruising speeds while aggregating at nearshore nursery habitats (0.6 m s-1 [mean ± S.E = 0.59 ± 0.001], 0.3 TL s-1) are likely a feature of behavioral strategies designed to optimize bioenergetic efficiency, by modulating activity rates in response to environmental temperature profiles to buffer heat loss and maintain homeostasis. Such behavioral strategies more closely resemble those exhibited in ectotherm sharks, than mature conspecifics.

PMID:35679282 | DOI:10.1371/journal.pone.0268914

PLoS Negl Trop Dis. 2022 Jun 9;16(6):e0010441. doi: 10.1371/journal.pntd.0010441. eCollection 2022 Jun.

ABSTRACT

Chikungunya, a mosquito-borne disease, is a growing threat in Brazil, where over 640,000 cases have been reported since 2017. However, there are often long delays between diagnoses of chikungunya cases and their entry in the national monitoring system, leaving policymakers without the up-to-date case count statistics they need. In contrast, weekly data on Google searches for chikungunya is available with no delay. Here, we analyse whether Google search data can help improve rapid estimates of chikungunya case counts in Rio de Janeiro, Brazil. We build on a Bayesian approach suitable for data that is subject to long and varied delays, and find that including Google search data reduces both model error and uncertainty. These improvements are largest during epidemics, which are particularly important periods for policymakers. Including Google search data in chikungunya surveillance systems may therefore help policymakers respond to future epidemics more quickly.

PMID:35679262 | DOI:10.1371/journal.pntd.0010441

PLoS One. 2022 Jun 9;17(6):e0269605. doi: 10.1371/journal.pone.0269605. eCollection 2022.

ABSTRACT

BACKGROUND & OBJECTIVE: Heterozygous familial hypercholesterolemia (FHeH) is important risk factor for premature coronary artery disease (CAD). Strategies for its diagnosis and prevalence have not been well studied in India. We performed healthcare worker-based opportunistic screening to assess feasibility for determining its prevalence.

METHODS: A healthcare worker was trained in use of Dutch Lipid Clinic Network (DLCN) criteria for diagnosis of FHeH. Successive eligible individuals (n = 3000 of 3450 screened) presenting to biochemistry laboratories of two hospitals for blood lipid measurements were evaluated for FHeH. Cascade screening or genetic studies were not performed. Descriptive statistics are reported.

RESULTS: We included 2549 participants (men 1870, women 679) not on statin therapy. Health worker screened 25-30 individuals/day in 6-10 minutes each. The mean age was 46.2±11y. Variables of DLCN criteria were more in women vs men: family history 51.1 vs 35.6%, past CAD 48.2 vs 20.1%, arcus cornealis 1.1 vs 0.3%, tendon xanthoma 0.3 vs 0.1%, and LDL cholesterol 190-249 mg/dl in 8.5 vs 2.4%, 250-329 mg/dl in 0.7 vs 0% and ≥330 mg/dl in 0.3 vs 0% (p<0.01). Definite FHeH (DLCN score >8) was in 15 (0.59%, frequency 1:170) and probable FHeH (score 6-8) in 87 (3.4%, frequency 1:29). The prevalence was significantly greater in women, age <50y and in those with hypertension, diabetes and known CAD.

CONCLUSIONS: Healthcare worker-led opportunistic screening for diagnosis of FHeH using DLCN criteria is feasible in low-resource settings. The results show significant prevalence of clinically detected definite and probable FHeH in the population studied.

PMID:35679249 | DOI:10.1371/journal.pone.0269605

Multivariate Behav Res. 2022 Jun 9:1-21. doi: 10.1080/00273171.2022.2077287. Online ahead of print.

ABSTRACT

Researchers with mediation hypotheses must consider which design to use: within-subject or between-subject? In this paper, I argue that three factors should influence design choice: validity, causality, and statistical power. Threats to validity include carry-over effects, participant awareness, measurement, and more. Causality is a core element of mediation, and the assumptions required for causal inference differ between the two designs. Between-subject designs require more restrictive no-confounder assumptions, but within-subject designs require the assumption of no carry-over effects. Statistical power should be higher in within-subject designs, but the degree and conditions of this advantage are unknown for mediation analysis. A Monte Carlo simulation compares designs under a broad range of sample sizes, effect sizes, and correlations among repeated measurements. The results show within-subject designs require about half the sample size of between-subject designs to detect indirect effects of the same size, but this difference can vary with population parameters. I provide an empirical example and R script for conducting power analysis for within-subject mediation analysis. Researchers interested in conducting mediation analysis should not select within-subject designs merely because of higher power, but they should also consider validity and causality in their decision, both of which can favor between-subject designs.

PMID:35679239 | DOI:10.1080/00273171.2022.2077287

PLoS Comput Biol. 2022 Jun 9;18(6):e1010101. doi: 10.1371/journal.pcbi.1010101. eCollection 2022 Jun.

ABSTRACT

Undergraduate students from underrepresented backgrounds (e.g., Black, Indigenous, and people of color [BIPOC], members of the Deaf community, people with disabilities, members of the 2SLGBTQIA+ community, from low-income backgrounds, or underrepresented genders) continue to face exclusion and marginalization in higher education. In this piece, authored and edited by a diverse group of Science, Technology, Engineering, and Mathematics (STEM) scholars, we present 10 simple rules for succeeding as an underrepresented STEM undergraduate student, illuminating the “hidden curriculum” of STEM specifically as it relates to the underrepresented undergraduate experience. Our rules begin by encouraging students to embrace their own distinct identities and scientific voices and explain how students can overcome challenges unique to underrepresented students throughout their undergraduate degrees. These rules are derived from a combination of our own experiences navigating our undergraduate STEM degrees and the growing body of literature on improving success for underrepresented students.

PMID:35679237 | DOI:10.1371/journal.pcbi.1010101

J Comp Eff Res. 2022 Jun 9. doi: 10.2217/cer-2022-0070. Online ahead of print.

ABSTRACT

Background: Relative overall survival (OS) estimates reported in the MAVORIC trial are potentially confounded by a high proportion of patients randomized to vorinostat switching to mogamulizumab; furthermore, vorinostat is not used in clinical practice in the UK. Methods: Three methods were considered for crossover adjustment. Survival post-crossover adjustment was compared with data from the Hospital Episode Statistics (HES) to contextualize estimates. Results: Following adjustment, the OS hazard ratio for mogamulizumab versus vorinostat was 0.42 (95% CI: 0.18, 0.98) using the method considered most appropriate based on an assessment of assumptions and comparison with HES. Conclusions: OS of mogamulizumab relative to vorinostat may be underestimated in MAVORIC due to the presence of crossover. The HES database was used to validate this adjustment.

PMID:35678206 | DOI:10.2217/cer-2022-0070

Med Phys. 2022 Jun 9. doi: 10.1002/mp.15799. Online ahead of print.

ABSTRACT

PURPOSE: Deep neural networks (DNNs) have been widely applied in medical image classification, benefiting from its powerful mapping capability among medical images. However, these existing deep learning-based methods depend on an enormous amount of carefully labeled images. Meanwhile, noise is inevitably introduced in the labeling process, degrading the performance of models. Hence, it is significant to devise robust training strategies to mitigate label noise in the medical image classification tasks.

METHODS: In this work, we propose a novel Bayesian statistics guided label refurbishment mechanism (BLRM) for DNNs to prevent overfitting noisy images. BLRM utilizes maximum a posteriori probability (MAP) in the Bayesian statistics and the exponentially time-weighted technique to selectively correct the labels of noisy images. The training images are purified gradually with the training epochs when BLRM is activated, further improving classification performance.

RESULTS: Comprehensive experiments on both synthetic noisy images (public OCT & Messidor datasets) and real-world noisy images (ANIMAL-10N) demonstrate that BLRM refurbishes the noisy labels selectively, curbing the adverse effects of noisy data. Also, the anti-noise BLRM integrated with DNNs are effective at different noise ratio and are independent of backbone DNN architectures. In addition, BLRM is superior to state-of-the-art comparative methods of anti-noise.

CONCLUSIONS: These investigations indicate that the proposed BLRM is well capable of mitigating label noise in medical image classification tasks. This article is protected by copyright. All rights reserved.

PMID:35678232 | DOI:10.1002/mp.15799

Photodermatol Photoimmunol Photomed. 2022 Jun 9. doi: 10.1111/phpp.12811. Online ahead of print.

ABSTRACT

PURPOSE: To assess the clinical periodontal, bacterial, and immunological outcomes of chloro-aluminum phthalocyanine-mediated-photodynamic therapy (PDT) as an adjunct to dental scaling (DS) versus DS alone among cigarette smokers (CS) and never-smokers (NS).

METHODS: A total of 26 patients (13 CS and 13 NS) with clinical and radiographic diagnosis of stage II chronic periodontitis were recruited. Each patient from both groups were subjected with two parallel therapies (split-mouth): PDT + DS (test side) and DS alone (control side). Periodontal parameters were investigated by evaluating plaque scores (PS), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL) and alveolar bone loss (ABL). Subgingival plaque was collected to detect and quantify Porphyromonas gingivalis and Tannerella forsythia using real-time quantitative polymerase chain reaction (RT-qPCR) assay. Gingival crevicular fluid was sampled for the quantification of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α) using enzyme linked immunosorbent assay. All assessments were performed at baseline, 3 months, and 6 months.

RESULTS: BOP was significantly reduced at 6 months after PDT+DS in CS groups (p<0.05). Mean PD and CAL significantly reduced after both PDT+DS and DS subgroups and among NS and CS groups (p<0.05). At 6 months follow up, the copy number of both P. gingivalis and T. forsythia remained significantly high in CS group (p<0.01). Only PDT+DS subgroup in CS significantly reduced the counts of P. gingivalis and T. forsythia at 3 months and 6 months (p<0.05). Only at 6 months did PDT+DS showed statistically significantly reduced IL-1β levels in the NS group (p<0.01). TNF-α levels significantly reduced in CS group with PDT+DS and DS alone at both 3 months and 6 months follow up (p<0.01).

CONCLUSION: Chloro-aluminum phthalocyanine-mediated PDT helped to improve the non-surgical periodontal therapy outcomes among stage II chronic periodontitis patients among smokers and never-smokers.

PMID:35678189 | DOI:10.1111/phpp.12811

Palliat Support Care. 2022 Jun 9:1-7. doi: 10.1017/S1478951522000694. Online ahead of print.

ABSTRACT

OBJECTIVES: A meta-analysis has explored the effect of psychotherapy on the quality of life (QOL) but has not explored the effect on advanced cancer patients’ survival, which is highly debated. Therefore, we consider the survival days and QOL as the primary outcomes in our analysis.

METHODS: Eligible studies were collected from four databases (PubMed, Embase, Cochrane Library, and Web of Science) until February 20, 2021. The pooled effect sizes were presented as weighted mean difference (WMD) or relative risk (RR) with 95% confidence intervals (CIs). Publication bias was evaluated by Egger’s test, and I² statistics was used to assess the heterogeneity.

RESULTS: Thirty-three studies were finally included, containing 2,159 patients in the psychotherapy group and 2,170 patients in the control group. McGill Quality of Life Questionnaire (MQOL) and European Organization for Research and Treatment of Cancer Quality of Life-C15-Palliative (EORTC-QLQ-C15-Pal) supported that QOL of the psychotherapy group was significantly higher than that of the control group, and WMD value was 0.42 (95% CI: 0.12-0.71) and 17.26 (95% CI: 11.08-23.44), respectively. No significant difference was observed between the two groups regarding to the survival time (WMD: 17.85, 95% CI: -8.79, 44.49, P = 0.189). Moreover, the levels of anxiety, depression, confusion, pain, and suffering were lowered in psychotherapy group (all P < 0.05).

SIGNIFICANCE OF RESULTS: Psychotherapy could improve the QOL of advanced cancer patients but not affect the survival time.

PMID:35678169 | DOI:10.1017/S1478951522000694

JDR Clin Trans Res. 2022 Jun 9:23800844221101800. doi: 10.1177/23800844221101800. Online ahead of print.

ABSTRACT

INTRODUCTION: Early childhood caries (ECC) is a complex oral disease that is prevalent in US children.

OBJECTIVES: The purpose of this 2-y prospective cohort study was to examine baseline and time-dependent risk factors for ECC onset in initially caries-free preschool children.

METHODS: A cohort of 189 initially caries-free children aged 1 to 3 y was recruited. At each 6-mo study visit, children were examined using the ICDAS index; salivary samples were collected to assess mutans streptococci (MS), lactobacilli, Candida species, salivary cortisol (prior and after a stressor), and salivary IgA. Diet and oral health behavior were assessed from parent report. Child and family stress exposure was assessed from measures of psychological symptoms, stressful life event exposure, family organization and violence exposure, and social support. Sociodemographic factors were also considered. A Kaplan-Meier estimator of survival function of time to ECC and a Cox proportional hazards model were used to identify predictors of ECC onset.

RESULTS: Onset of ECC was associated with high salivary MS levels at baseline (log-rank test, P < 0.0001). Cox proportional hazards regression showed that the risk of dental caries significantly increased with salivary MS in log scale over the 6-mo period (hazard ratio, 1.08; P = 0.01). Other risk factors in the model did not reach statistical significance.

CONCLUSION: Our results provide prospective evidence that an increase in salivary MS predicts ECC onset in young, initially caries-free children, confirming that a high salivary MS count likely plays a causal role in ECC onset, independent of covariates.

KNOWLEDGE TRANSFER STATEMENT: These results suggest that we must focus on reducing salivary MS counts in young children and preventing or delaying MS colonization in infants and young children determined to be at risk for ECC.

PMID:35678084 | DOI:10.1177/23800844221101800