Large Scale Daily Contacts and Mobility Model - an Individual-Based Countrywide Simulation Study for Poland

In this study we describe a simulation platform used to create a virtual society of Poland, with a particular emphasis on contact patterns arising from daily commuting to schools or workplaces. In order to reproduce the map of contacts, we are using a geo-referenced Agent Based Model. Within this framework, we propose a set of different stochastic algorithms, utilizing available aggregated census data. Based on this model system, we present selected statistical analysis, such as the accessibility of schools or the location of rescue service units. This platform will serve as a base for further large scale epidemiological and transportation simulation studies. However, the first approach to a simple, country-wide transportation model is also presented here. The application scope of the platform extends beyond the simulations of epidemic or transportation, and pertains to any situation where there are no easily available means, other than computer simulations, to conduct large scale investigations of complex population dynamics.Agent Based Model, Educational Availability, Daily Commuting, Social Network, Virtual Society Simulations

A SIMPLE MATHEMATICAL MODEL OF A SINGLE SCULLING TECHNIQUE

The results in sport in rowing depend on the two most important factors, such as the athlete physical features and the techniques of motion. The assessment and optimisation of rowing techniques are possible only when one disposes the reliable mathematical model predicting the results of the regatta that is the time of covering an assumed distance. A single scull participating in the 2000 meters distance regatta is our subject. The purpose of this study is to create a simplified mathematical model to simulate the rowing boat dynamics. The boat-rower system is treated as a material point here. The oar has a prescribed angular motion vs. oarlock depending on the time. The hydrodynamics force distribution to be developed on the oar’s blade has been modelled here. Then, the boat motion was described by a single nonlinear ordinary differential equation (NODE). The proposed simple model gives the possibilities of fast and reliable simulation of the single sculling technique and forecasts the result of rowing regattas

Detection and Distinction of Mild Brain Injury Effects in a Ferret Model Using Diffusion Tensor MRI (DTI) and DTI-Driven Tensor-Based Morphometry (D-TBM)

Mild traumatic brain injury (mTBI) is highly prevalent but lacks both research tools with adequate sensitivity to detect cellular alterations that accompany mild injury and pre-clinical models that are able to robustly mimic hallmark features of human TBI. To address these related challenges, high-resolution diffusion tensor MRI (DTI) analysis was performed in a model of mild TBI in the ferret – a species that, unlike rodents, share with humans a gyrencephalic cortex and high white matter (WM) volume. A set of DTI image analysis tools were optimized and implemented to explore key features of DTI alterations in ex vivo adult male ferret brains (n = 26), evaluated 1 day to 16 weeks after mild controlled cortical impact (CCI). Using template-based ROI analysis, lesion overlay mapping and DTI-driven tensor-based morphometry (D-TBM) significant differences in DTI and morphometric values were found and their dependence on time after injury evaluated. These observations were also qualitatively compared with immunohistochemistry staining of neurons, astrocytes, and microglia in the same tissue. Focal DTI abnormalities including reduced cortical diffusivity were apparent in 12/13 injured brains with greatest lesion extent found acutely following CCI by ROI overlay maps and reduced WM FA in the chronic period was observed near to the CCI site (ANOVA for FA in focal WM: time after CCI p = 0.046, brain hemisphere p = 0.0012) often in regions without other prominent MRI abnormalities. Global abnormalities were also detected, especially for WM regions, which demonstrated reduced diffusivity (ANOVA for Trace: time after CCI p = 0.007) and atrophy that appeared to become more extensive and bilateral with longer time after injury (ANOVA for D-TBM Log of the Jacobian values: time after CCI p = 0.007). The findings of this study extend earlier work in rodent models especially by evaluation of focal WM abnormalities that are not influenced by partial volume effects in the ferret. There is also substantial overlap between DTI and morphometric findings in this model and those from human studies of mTBI implying that the combination of DTI tools with a human-similar model system can provide an advantageous and informative approach for mTBI research

Inferior vena cava size is not associated with shock following injury

Background: The inferior vena cava (IVC) collapses with shock but may also be collapsed in volume-depleted patients in the absence of shock. The speed and availability of computed tomography (CT) make IVC measurement an attractive diagnostic modality for shock. The purpose of this study was to determine if IVC size following injury is associated with shock. Methods: Retrospective data were collected on 272 trauma patients admitted to an adult trauma center from January 1 to December 31, 2012. Patients who met the highest-level activation criteria and underwent an abdominal CT scan during their initial resuscitation were included. All images were reviewed by two attending radiologists, and concordance was assessed using the Pearson correlation coefficient. The transverse (T) and anteroposterior (AP) diameters of the IVC were measured to calculate a T/AP ratio. Analysis of variance and χ were used to assess for a relationship between this ratio and various indices of shock. Results: The mean (SD) age of the study cohort was 50 (21) years, mean (SD) Injury Severity Score (ISS) was 14 (9), 74% were male, and 96% sustained blunt trauma. The overall mean (SD) T/AP ratio was 1.81 (0.68). Patients with a shock index greater than 0.7 were significantly younger (43 [20] years vs. 55 [21] years, p \u3c 0.0001), had a significantly lower mean arterial pressure (88 [15] mm Hg vs. 103 [18] mm Hg, p \u3c 0.0001), and were more likely to be intubated (56% vs. 24%, p \u3c 0.0001). However, IVC T/AP ratio was not significantly different among the cohort. Similarly, there was no association between IVC size and the need for urgent operation, angiography, emergent transfusion, hospital length of stay, or mortality. Conclusion: The static degree of IVC collapse is not associated with shock following injury. Therefore, measurement of IVC size by CT scan for patients with a T/AP ratio between 1 and 3.5 is not clinically relevant and cannot be used to predict mortality, shock, or impending shock. Copyright © 2014 Lippincott Williams & Wilkins