The skiers knee without swelling or instability, a difficult diagnosis: a case report

Skiing as a recreational activity has increased exponentially in the last twenty-years. Similar to any sporting activity, participants can sustain various types of injury, which provides the emergency departments with a continuous supply of patients. The injury pattern from the slopes has also changed over this time period, due to alterations and improvements in ski equipment. An increased diversity in alpine skiing techniques, as well as snowboarding and cross-terrain disciplines has also influenced this change. We present a multi-media experience of a high-speed ski fall that caused a valgus-external rotation injury to the right knee that precluded the patient from further ski activity. There was no bruising, swelling or instability demonstrated and the patient returned to ski activities 24-hours post-injury. Although this injury appeared clinically benign initially, the patient complained of persistent pain around the right knee which was causing occupational difficulties. Following normal clinical assessment, the patient returned to work but continued to complain of persistent pain at the lateral aspect of the right knee. Magnetic Resonance Imaging (MRI) demonstrated extensive bone marrow oedema (BMO), a mild depression of the articular cortex compression with a small focus of articular cartilage disruption and microfractures of the lateral tibial plateau. The patient was treated conservatively and remains well with avoidance of impact exercises 14-months post-injury. In the presence of any high speed injury, we would stress that regardless of initial normal investigations, clinical suspicion should remain paramount and not deter the physician from further investigation in the presence of continuing symptomatology

The development of behavioral and endocrine abnormalities in rats after repeated exposure to direct and indirect stress

The present study compared the effects of direct and indirect stress on the behavior and hypothalamic-pituitary-adrenal axis of rats. Animals were placed in a two compartment box. In one compartment the direct stressed rat was subjected to electric foot shocks randomly applied for 10 minutes (0.5 mA of 1 s duration). In the adjacent compartment, the indirect stressed rats witnessed the application of these electric foot shocks. Our data showed substantial behavioral changes in the open field test, but limited effects in the elevated plus maze. The findings suggested that single and repeated stress exposure may have different consequences, that the effects of stress exposure may develop over time and persist for an extended period, and that both direct and indirect stressed rats displayed a hyposensitive HPA axis following acute restraint stress. Overall our observations moderately indicate direct exposure to elicit behavioral changes, and both direct and indirect exposure to stress to result in aberrations within the neuroendocrine system. With additional development our stress models may be considered for studying the complex interrelationship between an external stressor, and the experience of the organism

Time from presentation to pre-diagnostic chest X-ray in patients with symptomatic lung cancer: a cohort study using electronic patient records from English primary care.

BACKGROUND: National guidelines in England recommend prompt chest X-ray (within 14 days) in patients presenting in general practice with unexplained symptoms of possible lung cancer, including persistent cough, shortness of breath, or weight loss. AIM: To examine time to chest X-ray in symptomatic patients in English general practice before lung cancer diagnosis, and explore demographical variation. DESIGN AND SETTING: Retrospective cohort study using routinely collected general practice, cancer registry, and imaging data from England. METHOD: Patients with lung cancer who presented symptomatically in general practice in the year pre-diagnosis and who had a pre-diagnostic chest X-ray were included. Time from presentation to chest X-ray (presentation-test interval) was determined and intervals classified based on national guideline recommendations as concordant (≤14 days) or non-concordant (>14 days). Variation in intervals was examined by age, sex, smoking status, and deprivation. RESULTS: In a cohort of 2102 patients with lung cancer, the median presentation-test interval was 49 (interquartile range [IQR] 5-172) days. Of these, 727 (35%) patients had presentation-test intervals of ≤14 days (median 1 [IQR 0-6] day) and 1375 (65%) had presentation-test intervals of >14 days (median 128 [IQR 52-231] days). Intervals were longer among patients who smoke (equivalent to 63% longer than non-smokers; P<0.001), older patients (equivalent to 7% longer for every 10 years from age 27; P = 0.013), and females (equivalent to 12% longer than males; P = 0.016). CONCLUSION: In symptomatic primary care patients who underwent chest X-ray before lung cancer diagnosis, only 35% were tested within the timeframe recommended by national guidelines. Patients who smoke, older patients, and females experienced longer intervals. These findings could help guide initiatives aimed at improving timely lung cancer diagnosis

Biomechanics of Two External Fixator Devices Used in Rat Femoral Fractures

The use of external fixators allows for the direct investigation of newly formed interfragmentary bone, and the radiographic evaluation of the fracture. We validated the results of a finite element model with the in vitro stiffness' of two widely used external fixator devices used for in vivo analysis of fracture healing in rat femoral fractures with differing construction (Ti alloy ExFix1 and PEEK ExFix2). Rat femoral fracture fixation was modelled using two external fixators. For both constructs an osteotomy of 2.75 mm was used, and offset maintained at 5 mm. Tufnol, served as standardized substitutes for rat femora. Constructs were loaded under axial compression and torsion. Overall axial and torsional stiffness were compared between the in vitro models and FE results. FE models were also used to compare the fracture movement and overall pattern of von Mises stress across the external fixators. In vitro axial stiffness of ExFix1 was 29.26 N/mm ± 3.83 compared to ExFix2 6.31 N/mm ± 0.67 (p* < 0.05). Torsional stiffness of ExFix1 was 47.5 Nmm/° ± 2.71 compared to ExFix2 at 19.1 Nmm/° ± 1.18 (p* < 0.05). FE results predicted similar comparative ratios between the ExFix1 and 2 as the in vitro studies. FE results predicted considerably larger interfragmentary motion in the ExFix2 comparing to ExFix1. We demonstrated significant differences in the stiffness' of the two external fixators as one would expect from such variable designs; yet, importantly we validated the utility of an FE model for the analysis and prediction of changes in fracture mechanics dependent on fixator choice

Techniques in occluding the aorta during endovascular repair of ruptured abdominal aortic aneurysms

Among various methods to achieve rapid occlusion of the aorta during endovascular repair for ruptured abdominal aortic aneurysm, particular emphasis is placed on two techniques that have been incorporated into our endovascular repair practice. The sheath-over-balloon technique (the Loan SOB technique) facilitates hemodynamic stability by transfemoral endovascular placement of an aortic occlusion balloon catheter to the infrarenal abdominal aorta. The balloon-ahead-of-graft technique (the Hornsby BAG technique) allows suprarenal hemodynamic control using a stent-graft system with a built-in balloon. The two techniques are simple, quick, and effective in achieving hemodynamic stability

Exploration via Planning for Information about the Optimal Trajectory

Many potential applications of reinforcement learning (RL) are stymied by the large numbers of samples required to learn an effective policy. This is especially true when applying RL to real-world control tasks, e.g. in the sciences or robotics, where executing a policy in the environment is costly. In popular RL algorithms, agents typically explore either by adding stochasticity to a reward-maximizing policy or by attempting to gather maximal information about environment dynamics without taking the given task into account. In this work, we develop a method that allows us to plan for exploration while taking both the task and the current knowledge about the dynamics into account. The key insight to our approach is to plan an action sequence that maximizes the expected information gain about the optimal trajectory for the task at hand. We demonstrate that our method learns strong policies with 2x fewer samples than strong exploration baselines and 200x fewer samples than model free methods on a diverse set of low-to-medium dimensional control tasks in both the open-loop and closed-loop control settings.Comment: Conference paper at Neurips 2022. Code available at https://github.com/fusion-ml/trajectory-information-rl. arXiv admin note: text overlap with arXiv:2112.0524

African-American Folk Art in Kentucky

1998 Kentucky Folk Art Center exhibition catalog of African-American folk art from Kentucky.https://scholarworks.moreheadstate.edu/kfac_exhibition_catalogs/1017/thumbnail.jp

The independent effects of hypovolemia and pulmonary vasoconstriction on ventricular function and exercise capacity during acclimatisation to 3800 m

We aimed to determine the isolated and combined contribution of hypovolemia and hypoxic pulmonary vasoconstriction in limiting left ventricular (LV) function and exercise capacity under chronic hypoxemia at high altitude. In a double‐blinded, randomized and placebo‐controlled design, twelve healthy participants underwent echocardiography at rest and during submaximal exercise before completing a maximal test to exhaustion at sea level (SL; 344 m) and after 5–10 days at 3800 m. Plasma volume was normalised to SL values, and hypoxic pulmonary vasoconstriction was reversed by administration of Sildenafil (50 mg) to create four unique experimental conditions that were compared with SL values; high altitude (HA), Plasma Volume Expansion (HA‐PVX), Sildenafil (HA‐SIL) and Plasma Volume Expansion with Sildenafil (HA‐PVX‐SIL). High altitude exposure reduced plasma volume by 11% (P < 0.01) and increased pulmonary artery systolic pressure (19.6 ± 4.3 vs. 26.0 ± 5.4, P < 0.001); these differences were abolished by PVX and SIL respectively. LV end‐diastolic volume (EDV) and stroke volume (SV) were decreased upon ascent to high altitude, but were comparable to sea level in the HA‐PVX. LV EDV and SV were also elevated in the HA‐SIL and HA‐PVX‐SIL trials compared to HA, but to a lesser extent. Neither PVX or SIL had a significant effect on the LV EDV and SV response to exercise, or the maximal oxygen consumption or peak power output. In summary, at 3800 m both hypovolemia and hypoxic pulmonary vasoconstriction contribute to the decrease in LV filling, however, restoring LV filling does not confer an improvement in maximal exercise performance