Tag: statistics

PLoS One. 2022 Jun 24;17(6):e0267711. doi: 10.1371/journal.pone.0267711. eCollection 2022.

ABSTRACT

The competition and physical fitness test results of the 2020 National Taekwondo Championship Series were analyzed using curve fitting, linear regression, and other statistical methods. As far as we know, it is the first Taekwondo competition that uses physical fitness test (PFT) scores as the 8-in-4 selection criteria. The results show that the probability of the final total score of the series of championships entering the top 8 or top 3 is exponentially related to PFT results. It finds that athletes with better PFT scores are more likely to enter the quarterfinals. Among athletes entering the semifinals, the athlete with the best physical fitness has the greatest probability of winning the championship. The difference in physical fitness between athletes is mainly reflected in the 30-meter sprint. Overall, the competitive performance of professional Taekwondo athletes is significantly positively correlated with their physical fitness, especially for female Taekwondo athletes. Through the results obtained, it is concluded that Taekwondo athletes need to strengthen physical training, specifically enhancing the explosive power.

PMID:35749558 | DOI:10.1371/journal.pone.0267711

J Fish Dis. 2022 Jun 24. doi: 10.1111/jfd.13675. Online ahead of print.

ABSTRACT

Pseudoloma neurophilia is a critical threat to the zebrafish (Danio rerio) model, as it is the most common infectious agent found in research facilities. In this study, our objectives were two-fold: (1) compare the application of diagnostic tools for P. neurophilia and (2) track the progression of infection using PCR and histology. The first experiment showed that whole-body analysis by qPCR (WB-qPCR) can be a standardized process, providing a streamlined diagnostic protocol, without the need for extraction of specific tissues. Evaluating the course of infection in experimentally infected fish, we showed key dynamics in infection. Starting with a low dose exposure of 8000 spores/fish, the prevalence remained low until 92 days post-exposure (dpe), followed by a 30%-40% prevalence by histology or 40%-90% by PCR until the end of the experiment at 334 dpe. WB-qPCR positively detected infection in more fish than histology throughout the study, as WB-qPCR detected the parasite as early as 4 dpe, whereas it was undetected by histology until 92 dpe. We also added a second slide for histologic analyses, showing an increase in detection rate from 24% to 26% when we combined all data from our experiments, but this increase was not statistically significant.

PMID:35749556 | DOI:10.1111/jfd.13675

PLoS One. 2022 Jun 24;17(6):e0270456. doi: 10.1371/journal.pone.0270456. eCollection 2022.

ABSTRACT

Three-dimensional tracking of cells is one of the most powerful methods to investigate multicellular phenomena, such as ontogenesis, tumor formation or wound healing. However, 3D tracking in a biological environment usually requires fluorescent labeling of the cells and elaborate equipment, such as automated light sheet or confocal microscopy. Here we present a simple method for 3D tracking large numbers of unlabeled cells in a collagen matrix. Using a small lensless imaging setup, consisting of an LED and a photo sensor only, we were able to simultaneously track ~3000 human neutrophil granulocytes in a collagen droplet within an unusually large field of view (>50 mm2) at a time resolution of 4 seconds and a spatial resolution of ~1.5 μm in xy- and ~30 μm in z-direction. The setup, which is small enough to fit into any conventional incubator, was used to investigate chemotaxis towards interleukin-8 (IL-8 or CXCL8) and N-formylmethionyl-leucyl-phenylalanine (fMLP). The influence of varying stiffness and pore size of the embedding collagen matrix could also be quantified. Furthermore, we demonstrate our setup to be capable of telling apart healthy neutrophils from those where a condition of inflammation was (I) induced by exposure to lipopolysaccharide (LPS) and (II) caused by a pre-existing asthma condition. Over the course of our experiments we have tracked more than 420.000 cells. The large cell numbers increase statistical relevance to not only quantify cellular behavior in research, but to make it suitable for future diagnostic applications, too.

PMID:35749549 | DOI:10.1371/journal.pone.0270456

PLoS One. 2022 Jun 24;17(6):e0270527. doi: 10.1371/journal.pone.0270527. eCollection 2022.

ABSTRACT

Structural durability of screw-cement-retained implant-supported zirconia-based restorations is an important factor in choosing the best type of restoration for clinical use. This study aimed to evaluate the effects of thermocycling on the fracture resistance of different types of screw-cement-retained implant-supported zirconia-based restoration. Two experimental groups (monolithic zirconia and porcelain-veneered zirconia) and a control group of porcelain-fused-to-metal restorations were fabricated via CAD-CAM (n = 14 per group). Half of the specimens of each group (n = 7) were subjected to 10000 thermal cycles. The compressive force was applied and the force leading to fracture was measured by using a Universal Testing Machine. The fractured modes were classified under a scanning electron microscope. The data were analyzed through two-way ANOVA, one-way ANOVA, and independent samples t-test (α = 0.05). Among the non-thermocycled subgroups, the monolithic zirconia specimens were significantly more fracture-resistant than the porcelain-veneered zirconia and porcelain-fused-to-metal groups (P<0.05); but it was not the same with aging (P>0.05). Thermocycling decreased the fracture resistance of all groups; however, the difference was not statistically significant (P<0.05). The monolithic zirconia presented higher fracture resistance than the bilayered restorations for screw-cement retained implant-supported restorations. Thermocycling decreased the fracture resistance of all types of restorations insignificantly which can be clinically important.

PMID:35749553 | DOI:10.1371/journal.pone.0270527

PLoS One. 2022 Jun 24;17(6):e0269576. doi: 10.1371/journal.pone.0269576. eCollection 2022.

ABSTRACT

INTRODUCTION: A sexually transmitted virus called the Human Papillomavirus is responsible for more than 99% of cervical cancer cases and its precursors. In 2019, the median survival time of cervical cancer patients at 5 years was 37 months. The survival time and predictors of death from cervical cancer vary in different study settings. This study was aimed to assess the time to death and to identify the major predictors of death of cervical cancer patients in Felege Hiwot Comprehensive Specialized Hospital.

METHODS: A facility-based retrospective follow-up study was conducted among 422 randomly selected cervical cancer patients in Felege Hiwot Comprehensive Specialized Hospital from 25th June 2017 to 31st March 2021. Data were extracted from the sampled patient charts by using a structured checklist which was prepared in an English version. Data were coded and then entered, edited, and cleaned using EPI-data 3.1 and exported to STATA14.2 statistical software for analysis. Frequencies and proportions were used to describe the study population with relevant variables and were presented using tables, pie charts, and graphs. Kaplan Meier and life table were used to describe the restricted mean survival time and the overall survival rates. Differences in survival among different variables were compared using the log-rank test. The assumption of proportional hazard was checked using Schoenfeld residual test. Variables having a P-value > 0.05 were considered as fulfilling the assumption. Variables with a significance level below 0.2 in the bivariable Cox regression model were included in a multivariable Cox regression model analysis, where Variables with a p-value < 0.05 were considered to be statistically significant at a 95% confidence interval. Model fitness was checked by Cox-Snell residual.

RESULTS: The mean follow up time of this cohort was 27.66 (CI: 26.96, 28.36) months, and the restricted mean survival time of cervical cancer patients in this study was 40.21 (95% CI: 38.95, 41.47) months. Being FIGO stage IV [AHR = 6.10, 95% CI: 2.18, 16.90)], having adenocarcinoma [AHR = 3.12, 95% CI: 1.34, 7.28)], having co-morbidity [AHR = 2.57, 95% CI: 1.29, 5.11)], and being initiated with radiotherapy [AHR = 4.57, 95% CI: 1.60, 13.06)] were a significant predictors of death from cervical cancer.

CONCLUSION: The restricted mean survival time of cervical cancer patients in this study was 40.21 months. Marital status, type of tumor histology, stage of disease, type of treatment initiated, and presence of co-morbidity were significant predictors of death for cervical cancer. Treatment of comorbidities in the early stage of cervical cancer plays a key role in maximizing the survival time of cervical cancer patients.

PMID:35749539 | DOI:10.1371/journal.pone.0269576

Plast Reconstr Surg. 2022 Jun 24. doi: 10.1097/PRS.0000000000009383. Online ahead of print.

ABSTRACT

INTRODUCTION: Women with breast cancer related genetic pathogenic variants (e.g. BRCA1, BRCA2) or with a strong family history carry lifetime risks of developing breast cancer of up to 80-90%. A significant proportion of these women proceed to bilateral risk reducing mastectomy (RRM). We aimed to document the surgical morbidity of RRM and establish whether a diagnosis of breast cancer at the time of surgery impacted on outcomes.

METHODS: Clinical details of 445 women identified as having >25% lifetime risk of developing breast cancer who underwent RRM and breast reconstruction were interrogated for surgical outcomes such as planned, unplanned and emergency procedures, complication rates, length of stay and longevity of breast reconstruction. These outcome measures were recorded in women diagnosed with breast cancer perioperatively (cancer group, CG) and those without malignancy (benign group, BG).

RESULTS: Median follow up was similar in both groups (BG, 70months; CG 73 months). Patients were older in the CG than BG (43y v 39y; p<0.001). Women in the CG required more planned procedures to complete reconstruction than those in the BG (4 v 2; p=0.002). Emergency procedures, unplanned surgical interventions (e.g. capsulectomy) and post reconstruction complication rates were similar between groups.One in five women overall required revisional surgery. Patients with autologous reconstructions had a revision rate of 1.24/1000 person years compared with 2.52 in the implant reconstruction group.

CONCLUSION: Women contemplating RRM can be reassured that this a safe and effective procedure but will likely take multiple interventions. This knowledge should be integral to obtaining informed consent.

PMID:35749222 | DOI:10.1097/PRS.0000000000009383

Phys Rev Lett. 2022 Jun 10;128(23):234502. doi: 10.1103/PhysRevLett.128.234502.

ABSTRACT

The scaling of acceleration statistics in turbulence is examined by combining data from the literature with new data from well-resolved direct numerical simulations of isotropic turbulence, significantly extending the Reynolds number range. The acceleration variance at higher Reynolds numbers departs from previous predictions based on multifractal models, which characterize Lagrangian intermittency as an extension of Eulerian intermittency. The disagreement is even more prominent for higher-order moments of the acceleration. Instead, starting from a known exact relation, we relate the scaling of acceleration variance to that of Eulerian fourth-order velocity gradient and velocity increment statistics. This prediction is in excellent agreement with the variance data. Our Letter highlights the need for models that consider Lagrangian intermittency independent of the Eulerian counterpart.

PMID:35749192 | DOI:10.1103/PhysRevLett.128.234502

Clin Implant Dent Relat Res. 2022 Jun 24. doi: 10.1111/cid.13118. Online ahead of print.

ABSTRACT

AIM: To compare the clinical and radiographic conditions and the expression of pro-inflammatory cytokines in peri-implant crevicular fluid (PICF) at two-piece/bone level (TP/BL) versus one-piece/tissue level (OP/TL) single implants with a laser-microgrooved collar after at least 5 years of loading.

MATERIALS AND METHODS: In total, 20 single TP/BL implants and 20 contralateral OP/TL implants, both with a laser-microgrooved collar surface, in 20 systemically and periodontally healthy subjects (12 males and 8 females, between the age of 36 and 64 [mean age of 49.7 ± 12.3 years]), were examined. Levels of IL-1β, IL-1RA, IL-6, IL-8, IL-17, b-FGF, G-CSF, GM-CSF, IFN, MIP-1β, TNF-α, and VEGF were assessed in PICF using the Bio-Plex 200 Suspension Array System. Plaque index (PI), probing depth (PD), bleeding on probing (BOP), and gingival recession (REC) were recorded. Radiographic crestal bone levels (CBL) were assessed at the mesial and distal aspects of the implant sites.

RESULTS: The mean PI, PD, BOP, and REC values had no significant differences in either group. A higher mean value of CBL with statistical difference was detected for TP/BL compared with OP/TL implants. The levels of IL-1β, IL-6, IL-8, GM-CSF, and MIP-1β and TNF-α were higher at TP/BL implants than at OP/TL implants. However, only IL-1β, IL-6, and TNF-α values presented significant differences between the groups.

CONCLUSIONS: Although after 5 years of loading single TP/BL and OP/TL implants with a laser-microgrooved collar surface presented similar good clinical conditions, a higher proinflammatory state and higher crestal bone loss were detected for TP/BL implants.

PMID:35749154 | DOI:10.1111/cid.13118

Int J Biostat. 2022 Jun 24. doi: 10.1515/ijb-2021-0047. Online ahead of print.

ABSTRACT

It has been reported that about half of biological discoveries are irreproducible. These irreproducible discoveries were partially attributed to poor statistical power. The poor powers are majorly owned to small sample sizes. However, in molecular biology and medicine, due to the limit of biological resources and budget, most molecular biological experiments have been conducted with small samples. Two-sample t-test controls bias by using a degree of freedom. However, this also implicates that t-test has low power in small samples. A discovery found with low statistical power suggests that it has a poor reproducibility. So, promotion of statistical power is not a feasible way to enhance reproducibility in small-sample experiments. An alternative way is to reduce type I error rate. For doing so, a so-called t _α -test was developed. Both theoretical analysis and simulation study demonstrate that t _α -test much outperforms t-test. However, t _α -test is reduced to t-test when sample sizes are over 15. Large-scale simulation studies and real experiment data show that t _α -test significantly reduced type I error rate compared to t-test and Wilcoxon test in small-sample experiments. t _α -test had almost the same empirical power with t-test. Null p-value density distribution explains why t _α -test had so lower type I error rate than t-test. One real experimental dataset provides a typical example to show that t _α -test outperforms t-test and a microarray dataset showed that t _α -test had the best performance among five statistical methods. In addition, the density distribution and probability cumulative function of t _α -statistic were given in mathematics and the theoretical and observed distributions are well matched.

PMID:35749155 | DOI:10.1515/ijb-2021-0047

J Comput Biol. 2022 Jun 24. doi: 10.1089/cmb.2021.0549. Online ahead of print.

ABSTRACT

Coordinated hunting is widely observed in animals, and sharing rewards is often considered a major incentive for its success. While current theories about the role played by sharing in coordinated hunting are based on correlational evidence, we reveal the causal roles of sharing rewards through computational modeling with a state-of-the-art Multi-agent Reinforcement Learning (MARL) algorithm. We show that counterintuitively, while selfish agents reach robust coordination, sharing rewards undermines coordination. Hunting coordination modeled through sharing rewards (1) suffers from the free-rider problem, (2) plateaus at a small group size, and (3) is not a Nash equilibrium. Moreover, individually rewarded predators outperform predators that share rewards, especially when the hunting is difficult, the group size is large, and the action cost is high. Our results shed new light on the actual importance of prosocial motives for successful coordination in nonhuman animals and suggest that sharing rewards might simply be a byproduct of hunting, instead of a design strategy aimed at facilitating group coordination. This also highlights that current artificial intelligence modeling of human-like coordination in a group setting that assumes rewards sharing as a motivator (e.g., MARL) might not be adequately capturing what is truly necessary for successful coordination.

PMID:35749149 | DOI:10.1089/cmb.2021.0549