The relationship of training methods between NCAA Division I Cross-Country runners with 10,000 meter performance

The scientific relationship between 10,000 meter performance and training methods of distance runners remains incompletely understood. Researchers such as Slovic (1977) and Pollock (1978) have attempted to study the relationship between training practices of distance runners with the use of surveys. However, these studies did not analyze the significance of various types of training regimens available. The purpose of this study was to evaluate the training methods of NCAA Division I runners and 10,000 meter performance. Fourteen Division I qualifying teams of the NCAA Division I national cross-country meet and 16 randomly chosen non-qualifying teams were recruited through the mail and direct contact. The respondents completed a survey which evaluated the training methods of the respective teams during the transition phase, competition phase, and peaking period which encompassed seven months of training. In the transition phase the non-qualifying teams ran significantly farther (p\u3c0.05) on their long runs than the qualifying teams. The qualifying teams ran more miles during the competition phase than the non-qualifiers (p\u3c0.05). No significant differences (p\u3e0.05) differences were noted between the qualifying and non-qualifying teams during the peaking period. No significant differences (p\u3e0.05) were noted between the lower seven and top seven qualifying teams during the transition phase. However, during the competition phase the lower seven teams used intervals, fartleks, and repetitions more frequently (p\u3c0.05) than the top seven qualifiers. Fartlek training during the peaking period was used more more often (p\u3c0.05) for the top seven teams than the lower seven qualifying teams. A Pearson correlation was performed to find correlations between final team time in the 10,000 meter run and various training indices obtained from the survey. Based on the results from this study, it was concluded that tempos, repetitions, intervals, and fartlek training during the transition phase were significantly (p\u3c0.05) and positively related to team 10,000 meter performance. Interval training and fartlek during the competition phase were significantly (p\u3c0.05) and positively related to team 10,000 meter performance. Tempo training during the peaking period was significantly (p\u3c0.05) and negatively related to team 10,000 meter performance. The training variables were further correlated with team rank at the Division I national crosscountry meet. Assessment of success based on order provided further insight on the training requisites for ultimate performance. Teams that ranked lower at the national cross-country meet practiced twice a day more often, and used fartlek training more frequently during the transition phase. For the competition phase, lower ranked teams used interval training and fartlek more often. Higher ranked teams used interval training more often during the peaking phase. From this study’s findings several recommendations were made concerning future research. Future studies should attempt to analyze differences that may exist between American and international training methods. A comparison of the training methods of the various collegiate divisions is needed to determine if similar training methods exist. Further research is needed on repetition, tempo, fartlek, and hill training to determine the physiological benefits that may be gained by using these training methods to peak an athlete. Further long term studies of the training of distance runners are needed

Der Plan Colombia: Kolumbien im Visier des Krieges gegen den Terror der USA in Lateinamerika

"Die Terroranschläge vom 11. September 2001 markieren auch in der Wahrnehmung und der Behandlung Lateinamerikas von Seiten der USA einen tiefen Einschnitt. Mit einem Schlag wurde die Einmischung in bewaffnete Konflikte anderer Länder wieder offen denkbar und salonfähig in Washington. Kolumbien ist ein Paradebeispiel für den außenpolitischen Wandel und die Konsequenzen, die sich daraus ergeben. Der Plan Colombia, ursprünglich ein nationaler Entwicklungsplan im Rahmen einer Friedensstrategie zur Beendigung des Bürgerkrieges, wandelte sich durch den Einfluss der USA zunächst zu einem Instrument der Drogenbekämpfung nach dem 11. September und schließlich zu einem Eckpfeiler des Krieges gegen den Terror in Lateinamerika. Was Bill Clinton bei der Formulierung und Durchsetzung des Plan Colombia noch explizit verdeutlichen musste, nämlich dass die militärischen Hilfen nur für den Einsatz im Kampf gegen illegale Drogen benutzt werden durften, war für die Bush-Regierung nur noch von geringer Wichtigkeit. Der "Krieg gegen die Drogen", der über die gesamten 90er Jahre hinweg und noch danach die Außenpolitik der USA gegenüber Kolumbien und der Region bestimmt hatte, wich einem neuen Bedrohungsszenario, dem "Krieg gegen den Terror"." (Brennpkt. Lat.am/DÜI)

Analysis of death in major trauma: value of prompt post mortem computed tomography (pmCT) in comparison to office hour autopsy

Background: To analyze diagnostic accuracy of prompt post mortem Computed Tomography (pmCT) in determining causes of death in patients who died during trauma room management and to compare the results to gold standard autopsy during office hours. Methods: Multiple injured patients who died during trauma room care were enrolled. PmCT was performed immediately followed by autopsy during office hours. PmCT and autopsy were analyzed primarily regarding pmCT ability to find causes of death and secondarily to define exact causes of death including accurate anatomic localizations. For the secondary analysis data was divided in group-I with equal results of pmCT and autopsy, group-II with autopsy providing superior results and group-III with pmCT providing superior information contributing to but not majorly causing death. Results: Seventeen multiple trauma patients were enrolled. Since multiple trauma patients were enrolled more injuries than patients are provided. Eight patients sustained deadly head injuries (47.1 %), 11 chest (64.7 %), 4 skeletal system (23.5 %) injuries and one patient drowned (5.8 %). Primary analysis revealed in 16/17 patients (94.1 %) causes of death in accordance with autopsy. Secondary analysis revealed in 9/17 cases (group-I) good agreement of autopsy and pmCT. In seven cases autopsy provided superior results (group-II) whereas in 1 case pmCT found more information (group-III). Discussion: The presented work studied the diagnostic value of pmCT in defining causes of death in comparison to standard autopsy. Primary analysis revealed that in 94.1% of cases pmCT was able to define causes of death even if only indirect signs were present. Secondary analysis showed that pmCT and autopsy showed equal results regarding causes of death in 52.9%. Conclusions: PmCT is useful in traumatic death allowing for an immediate identification of causes of death and providing detailed information on bony lesions, brain injuries and gas formations. It is advisable to conduct pmCT especially in cases without consent to autopsy to gain information about possible causes of death and to rule out possible clinical errors

LOWER SPINE LOADING AND PELVIC KINEMATICS THROUGHOUT A NEAR-MAXIMAL 10 KM RUN

The purpose of the present study was to investigate the effects of fatigue on lower back loading and pelvis kinematics in distance running. Kinetic and kinematic data of the whole body was recorded for 13 subjects during a near-maximal 10-km run. Pelvis kinematics were calculated in 3D while moments acting on the lumbar spine were determined by using a full body lumbar spine model in OpenSim. We found significant effects of running distance for pelvis kinematics in the transversal and sagittal plane whereas the lumbar spine moments increased significantly in the frontal and transversal plane. These results support earlier findings suggesting a connection between running and spinal or pelvic overuse injuries. Thus, distance runners should focus on a controlled arm swing and upper body rotation as well as pelvis stabilization

Simultaneous object detection and segmentation for patient‐specific markerless lung tumor tracking in simulated radiographs with deep learning

Background Real-time tumor tracking is one motion management method to address motion-induced uncertainty. To date, fiducial markers are often required to reliably track lung tumors with X-ray imaging, which carries risks of complications and leads to prolonged treatment time. A markerless tracking approach is thus desirable. Deep learning-based approaches have shown promise for markerless tracking, but systematic evaluation and procedures to investigate applicability in individual cases are missing. Moreover, few efforts have been made to provide bounding box prediction and mask segmentation simultaneously, which could allow either rigid or deformable multi-leaf collimator tracking. Purpose The purpose of this study was to implement a deep learning-based markerless lung tumor tracking model exploiting patient-specific training which outputs both a bounding box and a mask segmentation simultaneously. We also aimed to compare the two kinds of predictions and to implement a specific procedure to understand the feasibility of markerless tracking on individual cases. Methods We first trained a Retina U-Net baseline model on digitally reconstructed radiographs (DRRs) generated from a public dataset containing 875 CT scans and corresponding lung nodule annotations. Afterwards, we used an independent cohort of 97 lung patients to develop a patient-specific refinement procedure. In order to determine the optimal hyperparameters for automatic patient-specific training, we selected 13 patients for validation where the baseline model predicted a bounding box on planning CT (PCT)-DRR with intersection over union (IoU) with the ground-truth higher than 0.7. The final test set contained the remaining 84 patients with varying PCT-DRR IoU. For each testing patient, the baseline model was refined on the PCT-DRR to generate a patient-specific model, which was then tested on a separate 10-phase 4DCT-DRR to mimic the intrafraction motion during treatment. A template matching algorithm served as benchmark model. The testing results were evaluated by four metrics: the center of mass (COM) error and the Dice similarity coefficient (DSC) for segmentation masks, and the center of box (COB) error and the DSC for bounding box detections. Performance was compared to the benchmark model including statistical testing for significance. Results A PCT-DRR IoU value of 0.2 was shown to be the threshold dividing inconsistent (68%) and consistent (100%) success (defined as mean bounding box DSC > 0.6) of PS models on 4DCT-DRRs. Thirty-seven out of the eighty-four testing cases had a PCT-DRR IoU above 0.2. For these 37 cases, the mean COM error was 2.6 mm, the mean segmentation DSC was 0.78, the mean COB error was 2.7 mm, and the mean box DSC was 0.83. Including the validation cases, the model was applicable to 50 out of 97 patients when using the PCT-DRR IoU threshold of 0.2. The inference time per frame was 170 ms. The model outperformed the benchmark model on all metrics, and the comparison was significant (p 0.2 cases, but not over the undifferentiated 84 testing cases. Conclusions The implemented patient-specific refinement approach based on a pre-trained baseline model was shown to be applicable to markerless tumor tracking in simulated radiographs for lung cases

ExacTrac Dynamic workflow evaluation: Combined surface optical/thermal imaging and X‐ray positioning

In modern radiotherapy (RT), especially for stereotactic radiotherapy or stereotactic radiosurgery treatments, image guidance is essential. Recently, the ExacTrac Dynamic (EXTD) system, a new combined surface-guided RT and image-guided RT (IGRT) system for patient positioning, monitoring, and tumor targeting, was introduced in clinical practice. The purpose of this study was to provide more information about the geometric accuracy of EXTD and its workflow in a clinical environment. The surface optical/thermal- and the stereoscopic X-ray imaging positioning systems of EXTD was evaluated and compared to cone-beam computed tomography (CBCT). Additionally, the congruence with the radiation isocenter was tested. A Winston Lutz test was executed several times over 1 year, and repeated end-to-end positioning tests were performed. The magnitude of the displacements between all systems, CBCT, stereoscopic X-ray, optical-surface imaging, and MV portal imaging was within the submillimeter range, suggesting that the image guidance provided by EXTD is accurate at any couch angle. Additionally, results from the evaluation of 14 patients with intracranial tumors treated with open-face masks are reported, and limited differences with a maximum of 0.02 mm between optical/thermal- and stereoscopic X-ray imaging were found. As the optical/thermal positioning system showed a comparable accuracy to other IGRT systems, and due to its constant monitoring capability, it can be an efficient tool for detecting intra-fractional motion and for real-time tracking of the surface position during RT

Offline and online LSTM networks for respiratory motion prediction in MR-guided radiotherapy

Objective. Gated beam delivery is the current clinical practice for respiratory motion compensation in MR-guided radiotherapy, and further research is ongoing to implement tracking. To manage intra-fractional motion using multileaf collimator tracking the total system latency needs to be accounted for in real-time. In this study, long short-term memory (LSTM) networks were optimized for the prediction of superior–inferior tumor centroid positions extracted from clinically acquired 2D cine MRIs. Approach. We used 88 patients treated at the University Hospital of the LMU Munich for training and validation (70 patients, 13.1 h), and for testing (18 patients, 3.0 h). Three patients treated at Fondazione Policlinico Universitario Agostino Gemelli were used as a second testing set (1.5 h). The performance of the LSTMs in terms of root mean square error (RMSE) was compared to baseline linear regression (LR) models for forecasted time spans of 250 ms, 500 ms and 750 ms. Both the LSTM and the LR were trained with offline (offline LSTM and offline LR) and online schemes (offline+online LSTM and online LR), the latter to allow for continuous adaptation to recent respiratory patterns. Main results. We found the offline+online LSTM to perform best for all investigated forecasts. Specifically, when predicting 500 ms ahead it achieved a mean RMSE of 1.20 mm and 1.00 mm, while the best performing LR model achieved a mean RMSE of 1.42 mm and 1.22 mm for the LMU and Gemelli testing set, respectively. Significance. This indicates that LSTM networks have potential as respiratory motion predictors and that continuous online re-optimization can enhance their performance

Lectin from Triticum vulgaris (WGA) Inhibits Infection with SARS-CoV-2 and Its Variants of Concern Alpha and Beta

Even in the face of global vaccination campaigns, there is still an urgent need for effective antivirals against SARS-CoV-2 and its rapidly spreading variants. Several natural compounds show potential as antiviral substances and have the advantages of broad availabilities and large therapeutic windows. Here, we report that lectin from Triticum vulgaris (Wheat Germ Agglutinin) displays antiviral activity against SARS-CoV-2 and its major Variants of Concern (VoC), Alpha and Beta. In Vero B4 cells, WGA potently inhibits SARS-CoV-2 infection with an IC50 of <10 ng/mL. WGA is effective upon preincubation with the virus or when added during infection. Pull-down assays demonstrate direct binding of WGA to SARS-CoV-2, further strengthening the hypothesis that inhibition of viral entry by neutralizing free virions might be the mode of action behind its antiviral effect. Furthermore, WGA exhibits antiviral activity against human coronavirus OC43, but not against other non-coronaviruses causing respiratory tract infections. Finally, WGA inhibits infection of the lung cell line Calu-3 with wild type and VoC viruses with comparable IC50 values. Altogether, our data indicate that topical administration of WGA might be effective for prophylaxis or treatment of SARS-CoV-2 infections