Loss of Hypoxia Signaling Limits Physiologic and Muscle Adaptations to Aerobic Exercise in Aging

To assess the differential effects of exercise with age, Young (Y, 10-12 weeks) and Old (O, 23-25 months) mice were subjected to regimented treadmill running or no regimented exercise. Y, trained mice experienced a significant increase in maximal distance running, maximal speed of running, and lean muscle mass in comparison to age-matched, untrained controls. O mice did not improve significantly in any of these measures following training. Transcriptome analysis of gastrocnemius from Y mice demonstrated differential regulation of 120 genes with exercise. None of these genes were similarly regulated in the O group. Genes most upregulated following exercise in Y mice were direct targets of the hypoxia signaling pathway. Immunoblotting demonstrated that aryl hydrocarbon receptor nuclear translocator (ARNT), a critical regulator of hypoxia signaling, increased 3-fold with exercise in Y mice, but this increase was absent in O mice following exercise. To assess whether this loss of ARNT in O muscle impaired the exercise response, we generated a mouse with inducible, skeletal muscle-specific knockout of ARNT (ARNT muscle (m) KO). Following regimented exercise, ARNT mKO mice did not improve maximal distance running, maximal running speed, or lean muscle mass in comparison to untrained ARNT mKO mice. Littermate, age-matched ARNT wild type mice increased significantly in all of these measures following training. Administration of ML228, an ARNT agonist, increased maximal running distance and speed in response to exercise training in O mice. These results suggest that restoration of ARNT and hypoxia signaling may restore the physiologic response to exercise in aging.

On Maximal Distance Energy

Let G be a graph of order n. If the maximal connected subgraph of G has no cut vertex then it is called a block. If each block of graph G is a clique then G is called clique tree. The distance energy ED(G) of graph G is the sum of the absolute values of the eigenvalues of the distance matrix D(G). In this paper, we study the properties on the eigencomponents corresponding to the distance spectral radius of some special class of clique trees. Using this result we characterize a graph which gives the maximum distance spectral radius among all clique trees of order n with k cliques. From this result, we confirm a conjecture on the maximum distance energy, which was given in Lin et al. Linear Algebra Appl 467(2015) 29-39.

The Analysis of Experimental Deployment of IGLUNA 2019 Trans-Ice Longwave System

An experimental longwave system operating in the broadcasting spectrum with horizontal magnetic loop transmitting antennas is presented as an element of simulated lunar astronaut mission of the IGLUNA program of Swiss Space Center (ESA_Lab demonstrator) in June 2019 on the Klein Matterhorn glacier in Switzerland. The parameters of the antennas, the environment, the transmitter design, and propagation tests are presented. The best-suited propagation model is developed. As the system, using low powers, provided coverage of maximal distance of 2077.06 km, a single radio station of this type would cover about 36% of the Moon’s surface and allow in situ ground-penetrating research.

Abstract 14802: Relation of Non-exercise Walking Activity With Exercise Performance in Patients With Peripheral Artery Disease

Introduction: Structured exercise programs in home settings are beneficial for patients with peripheral artery disease (PAD). However, the impact of lower levels of walking activity accumulated separately from formal home exercise in PAD is unclear. The aim of this study was to determine the relation of non-exercise walking (NEW) activity with exercise performance in PAD. Methods: This was a post-hoc analysis from twenty patients with PAD enrolled in a 12-week structured home-based walking exercise program using diaries and accelerometry. Formal exercise sessions (3 sessions·week -1 ) were detected using patient-reported diary entries that corresponded with accelerometer step data. NEW activity was characterized as steps completed over five days each week, excluding steps during formal exercise sessions. The primary outcome for the intent-to-treat analysis was peak walking time (PWT) assessed on a graded treadmill. Secondary outcomes were claudication onset time (COT) from the graded treadmill test and maximal distance achieved during the six-minute walk test (6MWT). Pearson correlations evaluated the relation between NEW activity (step·week -1 ) and exercise performance outcomes using intensity (step·week -1 ) and duration (min·week -1 ) from formal exercise sessions as covariates. Results: NEW activity demonstrated a strong, positive correlation with change in PWT (r=0.50, p=0.04) when controlling for exercise intensity and duration during the 12-week intervention. Other exercise performance outcomes were not significantly related to NEW activity (COT: r=0.14; 6MWT maximal distance: r=0.27). Conclusions: A positive association was demonstrated between NEW activity and the primary outcome of PWT following 12 weeks of structured home-based walking exercise. Interventions to improve physical activity outside of formal exercise sessions may be beneficial for patients with PAD.

The value of a relatively safe method for predicting difficult laryngoscopy during the COVID-19 epidemic

Background: The current global situation of COVID-19 epidemic is serious. Routine preoperative methods to assess airway such as the interincisor distance, Mallampati classification, and the upper lip bite test have a certain risk of upper respiratory tract exposure and virus spread. The condyle-tragus maximal distance can be used to assess the airway, and the assessment method does not require the patient to expose the upper respiratory tract, but its value in predicting difficult laryngoscopy compared to other indicators (Mallampati classification, interincisor distance, and upper lip bite test) remains unknown. The purpose of this study was to observe the value of condyle-tragus maximal distance to predict difficult laryngoscopy, and provide a new idea for preoperative airway assessment during epidemic. Methods: We enrolled adult patients who underwent general anesthesia and tracheal intubation. The interincisor distance, Mallampati test result, upper lip bite test result, and the condyle-tragus maximal distance of each patient were evaluated prior to the initiation of anesthesia. The primary outcome was difficult laryngoscopy defined as the Cormack-Lehane Level > grade 2. Results: A total of 304 patients were successfully included in the study ,39 patients were identified as difficult laryngoscopy. The correlation between the condyle-tragus maximal distance and Cormack-Lehane Level was the highest (Spearman correlation coefficient, -0.317; P＜0.001), and the area under the ROC curve was the highest (AUC：0.699,P＜0.01). The condyle-tragus maximal distance <1 finger width was the most consistent with difficult laryngoscopy (κ=0.485;99% CI,0.286-0.612) and its OR value was 10.09(95%CI: 4.19-24.28), sensitivity was 0.469(95%CI: 0.325-0.617), specificity was 0.929(95%CI: 0.877-0.964), positive predictive value was 0.676 (95%CI: 0.484-0.745), negative predictive value was 0.847(95%CI :0.825-0.865). Conclusion: Compared with the interincisor distance , Mallampati classification and the upper lip bite test, the condyle-tragus maximal distance has higher value in predicting difficult laryngoscopy, which can become a safer airway assessment method during the epidemic of COVID-19. Trial registration: The study was registered on October 21, 2019 in the Chinese Clinical Trial Registry (ChiCTR1900026775).

Limit distributions of the maximal distance to the nearest neighbour

For sets of iid random points having a uniform (in a definite sense) distribution on the arbitrary metric space a maximal distance to the nearest neighbour is considered. By means of the Chen–Stein method new limit theorems for this random variable is proved. For random uniform samples from the set of binary cube vertices analogous results are obtained by the methods of moments.

Assessment of throwing arm biomechanics with a motusBASEBALLTM pitching sleeve during long-toss throws and pitching in college baseball pitchers

In baseball, long-toss throws are commonly used in return-to-throw programs and for general conditioning; however, the majority of these programs are based on conventional wisdom. Few studies have examined the biomechanics of long-toss throwing and the impact of throw distance. The purpose of this study was to determine if significant differences exist among commonly-used sub-maximal distance long-toss throws and mound pitching. Nineteen college baseball pitchers (19 ± 1.3 years; 88.3 ± 8.4 kg; and 73.9 ± 18.6 cm) wore a motusBASEBALL™ sleeve and sensor which measured peak elbow varus torque (VT), peak forearm angular velocity (Vmax), and peak arm-cocking angle (ACA). Each player completed five long-toss throws at distances of 27 m, 37 m, 46 m, 55 m and five pitches from a mound at regulation (18.4 m). There were no significant differences among throwing conditions for both VT and Vmax (p<0.05). For ACA, there was a significant increase (approximately 12°) as the long-toss distance increased. Coaches and trainers should be aware that sub-maximal distance long-toss throws (27 - 55 m+) generate high-magnitude throwing arm biomechanics (kinetics, velocities, range of motion) that approach or even exceed those generated during pitching; precaution needs to be used when implementing long-tosses into throwing and rehabilitation programs.

Maximal Distance Discounted and Weighted Revisit Period: A Utility Approach to Persistent Unmanned Surveillance

Autonomous unmanned vehicles are well suited for long-endurance, persistent intelligence, surveillance and reconnaissance (PISR) missions. In order to conduct missions, vehicles must implement a method of task selection. We propose the Maximal Distance Discounted & Weighted Revisit Period ([Formula: see text]) utility function as a solution. We derive [Formula: see text] as a zeroth-order approximation to an infinite horizon solution of PISR when formulated as a dynamic programming (DP) problem. We then use the DP solution to develop a heuristic utility function for autonomous task selections, with the goal of minimizing the prioritized revisit time to each task. Our function adapts to different task maps and task priorities, is scalable in the number of tasks, and is robust to the ad-hoc addition or removal of tasks. We demonstrate how the [Formula: see text] parameters influence vehicle behavior. We also prove that the policy results in steady-state task selections that are periodic and that such periodicity occurs regardless of initial conditions. We then demonstrate periodicity via numerical simulations on a set of test scenarios. We present a two-step heuristic methodology for selecting utility function parameters that deliver empirically good performance, which we demonstrate through a simulation-based comparison to a single-vehicle Traveling Salesman Problem (TSP) solution. The comparisons are based on four sample task maps designed to resemble operational scenarios.

Maximal distance spectral radius of trees

In this paper, we determine the unique tree that maximizes the distance spectral radius in the class of all trees in which each non-pendent vertex has degree at least [Formula: see text].