Stellar population models in the UV, I : characterisation of the New Generation Stellar Library

Context. The spectral predictions of stellar population models are not as accurate in the ultra-violet (UV) as in the optical wavelength domain. One of the reasons is the lack of high-quality stellar libraries. The New Generation Stellar Library (NGSL), recently released, represents a significant step towards the improvement of this situation. Aims. To prepare NGSL for population synthesis, we determined the atmospheric parameters of its stars, we assessed the precision of the wavelength calibration and characterised its intrinsic resolution. We also measured the Galactic extinction for each of the NGSL stars. Methods. For our analyses we used ULySS, a full spectrum fitting package, fitting the NGSL spectra against the MILES interpolator. Results. We find that the wavelength calibration is precise up to 0.1 px, after correcting a systematic effect in the optical range. The spectral resolution varies from 3 angstrom in the UV to 10 angstrom in the near-infrared (NIR), corresponding to a roughly constant reciprocal resolution R = lambda/delta lambda approximate to 1000 and an instrumental velocity dispersion sigma(sins) approximate to 130 km s(-1). We derived the atmospheric parameters homogeneously. The precision for the FGK stars is 42 K, 0.24 and 0.09 dex for T-eff, logg and [Fe/H], respectively. The corresponding mean errors are 29K, 0.50 and 0.48 dex for the M stars, and for the OBA stars they are 4.5 percent, 0.44 and 0.18 dex. The comparison with the literature shows that our results are not biased

Evaluation study of IEEE 1609.4 performance for safety and non-safety messages dissemination

The IEEE 1609.4 was developed to support multi-channel operation and channel switching procedure in order to provide both safety and non-safety vehicular applications. However, this protocol has some drawback because it does not make efficient usage of channel bandwidth resources for single radio WAVE devices and suffer from high bounded delay and lost packet especially for large-scale networks in terms of the number of active nodes. This paper evaluates IEEE 1609.4 multi-channel protocol performance for safety and non-safety application and compare it with the IEEE 802.11p single channel protocol. Multi-channel and single channel protocols are analyzed in different environments to investigate their performance. By relying on a realistic dataset and using OMNeT++ simulation tool as network simulator, SUMO as traffic simulator and coupling them by employing Veins framework. Performance evaluation results show that the delay of single channel protocol IEEE 802.11p has been degraded 36% compared with multi-channel protocol

The influence of acute variable resistance loading on subsequent free-weight maximal squat performance

Elastic bands attached to a loaded barbell during a squat exercise create a variable resistance (VR), thus changing the mechanical loading and stress placed through the musculoskeletal system. Preconditioning the neuromuscular system using near-maximal or maximal voluntary contractions (MVC) can induce a phenomenon known as post-activation potentiation (PAP) to enhance performance to ‘supramaximal’ levels. However, the potentiating effects of VR on subsequent free-weight resistance (FWR) squat performance have not been examined. Thus, the aim of the present study was to examine the influence of VR exercise using elastic bands on subsequent FWR squat performance. Sixteen recreationally active men (age = 26.0 ± 7.8 yr, height = 1.7 ± 0.2 m, mass 82.6 ± 12.7 kg) experienced in squatting (>3yr) volunteered for the study after giving written informed consent; ethical approval was granted from the University of Northampton. Subjects’ 1-RM were determined then on two subsequent days either a 3-RM FWR (control) or a 3-RM VR (experimental) squat exercise was performed at 85% 1-RM (35% of the load generated from band tension in the VR condition). Five minutes later, motion analysis recorded knee joint kinematics during a subsequent FWR 1-RM squat, with vastus medialis, vastus lateralis, rectus femoris and semitendinosus electromyograms (EMG) simultaneously recorded. Paired t-tests were used to determine significance, accepted at p0.05) or EMG amplitude (5.9%; p>0.05) occurred. No subjects increased 1-RM in the FWR condition, however 13 of 16 (81%) increased 1-RM by ~10% following VR. Preconditioning the neuromuscular system using VR significantly increased 1-RM without changes in knee extensor muscle activity or knee flexion angle, however eccentric and concentric velocities were reduced. Thus, VR can potentiate the neuromuscular system to enhance subsequent maximal lifting performance. The lack of change in EMG suggests that changes in muscle activity were small or non-existent, which may be explained by force-velocity effects (slower movement = larger forces). Alternatively a greater activation of hip musculature (not measured in the present study) may allow a greater total lower limb force to be developed. Regardless, as 1-RM increased greater lower-limb loading occurred, thus VR potentiated the neuromuscular system and could enhance training stimuli

COMPARING THE ACUTE EFFECTS OF WARM-UP STRATEGIES USING FREE-WEIGHT AND VARIABLE RESISTANCE ON STRENGTH AND POWER PERFORMANCE

Warm-up routines are typically designed to precondition the neuromuscular system for enhanced performance and reduced injury risk during subsequent high-intensity physical activities, including during strength training. As such, identifying an effective warm-up routine to augment muscular performance is of clear importance to strength (and other) coaches and athletes. Incorporating variable resistance (VR) via the use of chains or elastic bands during strength training alters the loading characteristics during exercises to impose a greater mechanical stimulus, however the impact of VR on subsequent free-weight exercise performance is unknown. Therefore, the aims of this thesis were to examine the acute effects of conditioning VR exercise compared to free-weight resistance (FWR) exercise on subsequent one-repetition maximum (1-RM) back squat and countermovement vertical jump (CMJ) height performance after the performance of a comprehensive, test-specific warm-up, and to examine possible alterations to mechanics and neuromuscular activity underpinning any changes. Techniques including 3D motion analysis, electromyography (EMG) and ground reaction force measurement were used in three studies on recreationally active volunteers experienced in squatting and jumping. In Study 1, significantly greater 1-RM squat-lift load (6.2 ± 5.0%; p 0.05) were detected in concentric phase EMG, knee angular velocity or peak knee flexion angle. Thus, performing a CLR warm-up enhanced subsequent free-weight 1-RM performance without kinematic changes; these data were considered to indicate a real 1-RM increase as the mechanics of the lift were not influenced. Study 2 followed an identical methodological design, however elastic bands were used to provide an inexpensive, portable, easily-implemented, and therefore more practical method of altering the load-time characteristics of the squat lift through VR. Significantly greater 1-RM squat load (7.7 ± 6.2%; p 0.05). However, statistical (p < 0.05) and practically-meaningful increases were detected in CMJ height (5.3-6.5%), net impulse (2.7-3.3%), take-off velocity (2.7-3.8%), peak power (4.4-5.9%), kinetic (7.1-7.2%) and potential (5.4-6.7%) energy, peak normalised rate of force development (12.9-19.1%), peak concentric knee angular velocities (3.1-4.1%) and mean concentric vastus lateralis (VL) EMG activity (27.5-33.4%) at all time points after the EB warm-up condition. Thus, when a complete CMJ-specific warm-up was provided, FWR squat had no additional effect on CMJ performance however the alteration of the squat lift force-time characteristics using EB led to a substantial CMJ enhancement. The findings from the present series of studies have important implications for research study design as the warm-up imposed and the resistive modality selected appear to influence subsequent movement performances, i.e. 1-RM back squat or CMJ performances. In previous studies, standardised (or no) warm-up protocols imposed before the baseline testing have been associated with subsequent enhancements in squat lift and CMJ performances following conditioning contractions, although it is unclear whether this is a consequence of acute neuromuscular alteration relating to the conditioning contractions or to the warm-up itself. Collectively, the present findings, show that physical performance can be enhanced in at least some conditions by application of conditioning contractions even after completion of a comprehensive, test-specific warm-up, which have important practical implications in the formulation of pre-performance warm-up routines where maximal force production is an important goal.N/

Complete and Voluntary Starvation of 50 days

A 34-year-old obese male (96.8 kg; BMI, 30.2 kg m⁻¹) volitionally undertook a 50-day fast with the stated goal of losing body mass. During this time, only tea, coffee, water, and a daily multivitamin were consumed. Severe and linear loss of body mass is recorded during these 50 days (final 75.4 kg; BMI, 23.5 kg m⁻¹). A surprising resilience to effects of fasting on activity levels and physical function is noted. Plasma samples are suggestive of early impairment of liver function, and perturbations to cardiovascular dynamics are also noted. One month following resumption of feeding behavior, body weight was maintained (75.0 kg; BMI, 23.4 kg m⁻¹). Evidence-based decision-making with the fasting or hunger striking patient is limited by a lack of evidence. This case report suggests that total body mass, not mass lost, may be a key observation in clinical decision-making during fasting and starvation

Relationship between protein biomarkers of chemotherapy response and microsatellite status, tumor mutational burden and PD-L1 expression in cancer patients.

Chemotherapy and checkpoint inhibitor immunotherapies are increasingly used in combinations. We determined associations between the presence of anti-PD-1/PD-L1 therapeutic biomarkers and protein markers of potential chemotherapy response. Data were extracted from a clinical-grade testing database (Caris Life Sciences; February 2015 through November 2017): immunotherapy response markers (microsatellite instability-high [MSI-H], tumor mutational burden-high [TMB-H], and PD-L1 protein expression) and protein chemotherapy response markers (excision repair complementation group 1 [ERCC1], topoisomerase 1 [TOPO1], topoisomerase 2 [TOP2A], thymidylate synthase [TS], tubulin beta 3 [TUBB3], ribonucleotide reductase regulatory subunit M1 [RRM1] and O-6-methyl guanine DNA methyltransferase [MGMT]). Relationships were determined by the Mantel-Haenszel chi-squared test or Fischer's exact tests. Overall, 28,034 patients representing a total of 40 tumor types were assessed. MSI-H was found in 3.3% of patients (73% were also TMB-H), TMB-H, 8.4% (28.3% were also MSI-H) and PD-L1 expression in 11.0% of patients (5.1% were also MSI-H; 16.4% were also TMB-H). Based on concurrent biomarker expression, combinations of immunotherapy with platinum (ERCC1 negativity) or with doxorubicin, epirubicin or etoposide (TOP2A positivity) have a higher probability of response, whereas combinations with irinotecan or topotecan (TOPO1 positivity), with gemcitabine (RRM1 negativity), and fluorouracil, pemetrexed or capecitabine (TS negativity) may be of less benefit. The potential for immunotherapy and taxane (TUBB3 negativity) combinations is present for MSI-H but not TMB-H or PD-L1-expressing tumors; for temozolomide and dacarbazine (MGMT negative), PD-L1 is frequently coexpressed, but MSI-H and TMB-H are not associated. Protein markers of potential chemotherapy response along with next-generation sequencing for immunotherapy response markers can help support rational combinations as part of an individualized, precision oncology approach

Hospitals as innovators in the health-care system: a literature review and research agenda

This paper aims to improve understanding of the role of hospitals in the generation of innovations. It presents a systematic and critical review of the interdisciplinary literature that addresses the links between the activities of hospitals and medical innovation. It identifies three major research streams: studies of the contribution of medical research and clinical staff to innovation, analyses of novel practices developed and diffused in hospitals, and evolutionary studies of technical change in the context of human health care. This is a highly heterogeneous body of literature, in which comprehensive theoretical frameworks are rare, and empirical studies have tended to focus on a narrow range of hospitals' innovation activities. The paper introduces and discusses a framework integrating different perspectives that can be used to analyze the functions performed by hospitals at the intersection with different partners in the health innovation system and at different stages of innovation trajectories. On the basis of current gaps in the literature, a research agenda is discussed for a relational and co-evolutionary approach to the study of hospitals as innovators.Research for this article was funded by the Research Council of Norway under the project “Synergies and tensions in innovation in the life sciences,” as well as by the South-Eastern Norway Regional Health Authority and the University of Oslo

The influence of 6 weeks of maximal eccentric plantarflexor training on muscle-tendon mechanics

Resistance training can influence muscle-tendon properties including strength, flexibility, stretch tolerance and muscle-tendon stiffness; however the specific influence of eccentric-only training is unknown. Therefore, the aims of the present study were to examine the effects of a 6-week maximal eccentric resistance training programme on isometric plantarflexor moment (MVC), dorsiflexion range of motion (ROM), stretch tolerance (peak passive moment), muscle and tendon stiffness and running economy. Thirteen recreationally active men (age = 20.0 ± 0.9 yr, mass = 75.9 ± 8.5 kg, height = 1.8 ± 0.1 m) volunteered for the study after giving written informed consent; ethical approval was granted from the University of Northampton. Training was performed twice weekly for six weeks and consisted of 5 sets of 12 repetitions of 3-s maximal eccentric contractions at 10°•s-1 from 20° plantarflexion to 10° dorsiflexion. Maximal isometric plantarflexor moment, dorsiflexion ROM, stretch tolerance, and muscle, tendon and muscle-tendon unit (MTU) stiffness were measured using isokinetic dynamometry, real-time ultrasound and 3D motion analyses before and after the training. Running economy (VO2) was determined at a running speed equating to 70%VO2max using online gas analysis. Repeated measures t-tests were used to determine significant differences between pre- and post-training data, significance accepted at p0.05). Analysis of ultrasound data revealed a significant decrease in muscle stiffness (20.6%; p0.05). While the training-induced increase in plantarflexor strength was expected, the substantial increases in ROM, stretch tolerance and tendon stiffness, and the reduction in passive muscle stiffness, were important and novel findings. Interestingly, when measured during passive stretch, MTU stiffness remained unchanged while tendon stiffness increased and muscle stiffness decreased. These disparate findings have clear implications for testing methodologies, and indicate that imaging techniques must be utilised in order to examine the effects of interventions on specific tissues. As the training clearly enhanced the capacity of the muscle to tolerate both tissue loading and deformation, which are commonly associated with muscle strain injury, these data have clear implications for both muscular performance and injury risk