Liquid rocket performance computer model with distributed energy release Interim final report, 15 Aug. 1969 - 15 Aug. 1970

Liquid propellant rocket engine performance computer program with distributed energy releas

MRI radiomic features are independently associated with overall survival in soft tissue sarcoma

Purpose: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. Methods and Materials: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell\u27s concordance index. Results: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; Conclusions: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS

Deterministic mechanical model of T-killer cell polarization reproduces the wandering of aim between simultaneously engaged targets

T-killer cells of the immune system eliminate virus-infected and tumorous cells through direct cell-cell interactions. Reorientation of the killing apparatus inside the T cell to the T-cell interface with the target cell ensures specificity of the immune response. The killing apparatus can also oscillate next to the cell-cell interface. When two target cells are engaged by the T cell simultaneously, the killing apparatus can oscillate between the two interface areas. This oscillation is one of the most striking examples of cell movements that give the microscopist an unmechanistic impression of the cell's fidgety indecision. We have constructed a three-dimensional, numerical biomechanical model of the molecular-motor-driven microtubule cytoskeleton that positions the killing apparatus. The model demonstrates that the cortical pulling mechanism is indeed capable of orienting the killing apparatus into the functional position under a range of conditions. The model also predicts experimentally testable limitations of this commonly hypothesized mechanism of T-cell polarization. After the reorientation, the numerical solution exhibits complex, multidirectional, multiperiodic, and sustained oscillations in the absence of any external guidance or stochasticity. These computational results demonstrate that the strikingly animate wandering of aim in T-killer cells has a purely mechanical and deterministic explanation. © 2009 Kim, Maly

Muscular Strength and Body Composition Comparison Between the Charlotte-Mecklenburg Fire and Police Departments

Firefighters and police have different physical job requirements and selection processes. Firefighters have on-duty exercise time and police do not. This could affect body composition and strength. The purpose of this investigation was to compare body composition and bench press strength between firefighters and police officers in the Charlotte-Mecklenburg departments. Current 2006 fitness records were analyzed to compare firefighters and police (N = 2330). Variables included: gender, age, body mass, percent body-fat, fat mass, lean mass, bench press strength, bench press/lean mass, bench press/body mass, and percent that were obese. Significant (p ≤ 0.05) differences were found between male firefighters and police in age (37.7 vs. 36.9 yrs), body mass (91.5 vs. 93.2 kg), percent body-fat (17.8% vs.18.5%), fat mass (16.9 vs. 18.0 kg), bench press strength (93.4 vs. 96.3 kg), bench press/body mass (1.03 vs.1.05) and percent that were obese (10% vs.17%), respectively. Significant differences between female firefighters and police were found in age (42.4 vs. 37.4 yrs), body mass (77.5 vs. 71.8 kg), lean mass (54.4 vs. 51.2 kg), bench press strength (52.3 vs. 43.9 kg), bench press/lean mass (0.99 vs. 0.86) and bench press/body mass (0.69 vs. 0.62), respectively. Male police were younger, weighed more, had higher percent body fat, higher percent of obesity, and had greater upper body strength than firefighters. Female police were younger, weighed less, had less lean mass and less upper body strength than their firefighter counterparts. Contributing factors might include pre-employment selection, recruit training, in-service physical fitness testing, and counseling provided by departments

Proposing new variables for the identification of strategic groups in franchising

The identification of strategic groups in the Spanish franchising area is the main aim of this study. The authors have added some new strategic variables (not used before) to the study and have classified franchisors between sectors and distribution strategy. The results reveal the existence of four perfectly differentiated strategic groups (types of franchisors). One of the major implications of this study is that the variables that build a strategic group vary depending on the respective sector the network operates in and its distribution strategy. This fact indicates that including sector and distribution strategy is absolutely necessary to achieve good classifications of franchisor type

The Effect of Cognitive-Behavioral Harriage Enrichment on Marital Adjustment Among Church Couples

This study evaluated the short- and long-term effect of a cognitive-behavioral marriage enrichment program on perceived marital adjustment. The study examined the Traits of the Happy Couple marriage enrichment workshop (Halter, 1988). The workshop consisted of five 2-hour training sessions held in five consecutive weeks for a total of 10 hours of training. It seeks to increase the marital adjustment of participants through a combination of didactic and experiential methods. No prior controlled study of the effectiveness of this workshop has been done. Participants included 34 married couples who were predominately from conservative, evangelical churches in the Portland, Oregon, area. The study utilized a protest-posttest control-group design with random assignment of participant couples to a treatment group and a wait-list control group. The treatment group participated in the workshop while the control group did not receive any treatment. Marital adjustment was measured by the global score on the Dyadic Adjustment Scale (DAS). Data was collected immediately prior to the marriage enrichment program, at the end of the workshop, .and six months after the marriage enrichment experience. A two-way ANCOVA vas used to evaluate the first three hypotheses which stated that couples, men, and women, respectively, who participated in the workshop would report a significant increase in their level of marital adjustment at the posttest. A repeated measures ANOVA was utilized to assess the last three hypotheses that the reported level of marital adjustment of couples, men, and women, respectively, from the treatment group would also be significantly higher at the six month follow-up test than at the pretest. The marriage enrichment workshop had a significant positive effect on marital adjustment. Couples, men, and women participating in the workshop had significantly higher levels of reported marital adjustment at its conclusion than those who did not. In addition, couples and men taking part in the workshop reported significantly higher marital adjustment at the six month follow-up test as compared to the pretest. While the Women in the treatment group reported gains in their marital adjustment at the follow-up test compared to the pretest, these changes ware not significant. No significant gender differences ill marital adjustment were found for the combined groups at the pretest or posttest. The large treatment effect size both at the posttest and the follow-up suggest that the intervention is a powerful enrichment program. The observed changes appear consistent with the general objectives of marriage enrichment in enhancing marital adjustment. These results suggest the potential usefulness of this workshop in enriching the marital relationships of conservative, evangelical couples. The findings of Noval, Combs, Wiinamaki, and Bufford (1993) suggest a variety of church and community groups are likely to experience similar benefits from this enrichment program