The importance of coupling between the atmosphere and the ocean for forecasting on time scales of hours to weeks has been demonstrated for a range of physical processes. Here, the authors evaluate ...the impact of an interactive air–sea coupling between an operational global deterministic medium-range weather forecasting system and an ice–ocean forecasting system. This system was developed in the context of an experimental forecasting system that is now running operationally at the Canadian Centre for Meteorological and Environmental Prediction. The authors show that the most significant impact is found to be associated with a decreased cyclone intensification, with a reduction in the tropical cyclone false alarm ratio. This results in a 15% decrease in standard deviation errors in geopotential height fields for 120-h forecasts in areas of active cyclone development, with commensurate benefits for wind, temperature, and humidity fields. Whereas impacts on surface fields are found locally in the vicinity of cyclone activity, large-scale improvements in the mid-to-upper troposphere are found with positive global implications for forecast skill. Moreover, coupling is found to produce fairly constant reductions in standard deviation error growth for forecast days 1–7 of about 5% over the northern extratropics in July and August and 15% over the tropics in January and February. To the authors’ knowledge, this is the first time a statistically significant positive impact of coupling has been shown in an operational global medium-range deterministic numerical weather prediction framework.
Modulation of lower limb somatosensory information by tendon or plantar vibration produces directionally specific, vibration-induced falling reactions that depend on the tendon or the region of the ...sole that is vibrated. This study characterized the effects of different patterns of plantar cutaneo-muscular vibration and bilateral Achilles tendon vibration (ATV) on the postural strategies observed during quiet and perturbed stance. Twelve healthy young participants stood barefooted, with their vision blocked, on two sets of plantar vibrators placed on two AMTI force plates embedded in a moveable support surface. Two other vibrators were positioned over the Achilles tendons. Participants were randomly exposed to different patterns of plantar cutaneo-muscular and ATV. Tilts of the support surface in the toes-up (TU) and toes-down (TD) directions were given 5–8
s after the beginning of vibration. Body kinematics in 3D and ground reaction forces were recorded. Bilateral ATV applied with or without rearfoot vibration (RFV) during quiet stance resulted in a whole-body backward leaning accompanied by an increase in trunk extension and hip and knee flexion. RFV alone produced a forward whole-body tilt with increased flexion in trunk, hip, and ankle. When stance was perturbed by TU tilts, the center of mass (CoM) and center of pressure (CoP) displacements were larger in the presence of RFV or ATV and associated with increased peak trunk flexion. TD tilts with or without ATV resulted in no significant difference in CoM and CoP displacements, while larger trunk extension and smaller distal angular displacements were observed during ATV. RFV altered the magnitude of the balance reactions, as observed by an increase in CoP displacements and variable response in trunk displacement. Significant interactions between ATV and RFV were obtained for the peak angular excursions for both directions of perturbations, where ATV either enhanced (for TU tilts) or attenuated (for TD tilts) the influence of RFV. Manipulating somatosensory information from the plantar cutaneo-muscular and muscle spindle Ia afferents thus results in altered and widespread postural responses, as shown by profound changes in body kinematics and CoM and CoP displacements. This suggests that the CNS uses plantar cutaneo-muscular and ankle spindle afferent inputs to build an appropriate reference of verticality that influences the control of equilibrium during quiet and perturbed stance.
Abstract Objective Altering proprioceptive information in the lower limbs by vibration produces direction-specific falling and postural instability, which can persist after vibration stops. The ...objectives of this study were to describe the changes in trunk and lower limbs postural orientation and muscles activities during and after the end of bilateral Achilles tendon vibration (TV). Methods Twelve healthy young subjects were exposed to 30 s periods of TV while blindfolded. Whole-body kinematics, kinetics and EMG of eight lower limb and trunk muscles were recorded prior, during and 5 or 25 s after TV. Results TV during quiet standing produced a whole-body backward shift characterized by greater extension in the trunk and lower limbs. Five seconds after TV, two trends of recovery could be observed, either an overcorrection or undercorrection of the initial position. Conclusions A continuum of postural orientations are adopted during and after vibration and the movements are not restricted to the ankle joints, despite the local nature of the proprioceptive stimulation. Significance The widespread influence of vibration as a proprioceptive stimulation when assessing its effects on posture and balance needs to be considered. Further studies should include whole-body analyses to document more thoroughly the postural strategies for balance maintenance during vibration.
Abstract
Reduced mobility and physical independence of elders has emerged as a major clinical and public health priority with extended life expectancy. The impact of the neuromuscular function on ...muscle activity and properties has emerged as a critical factor influencing the progress and outcome of muscle changes with aging. However, very little is known about the neuromuscular junctions (NMJs) in humans, in part due to technical constraints limiting the access to healthy, fresh neuromuscular tissue. Here, we describe a method, called Biopsy using Electrostimulation for Enhanced NMJ Sampling (BeeNMJs) that improves the outcome of muscle biopsies. We used local cutaneous stimulation to identify the area enriched with NMJs for each participant at the right Vastus lateralis (VL). The needle biopsy was then performed in proximity of that point. The BeeNMJs procedure was safe for the participants. We observed NMJs in 53.3% of biopsies in comparison with only 16.7% using the traditional method. Furthermore, we observed an average of 30.13 NMJs per sample compared to only 2.33 for the traditional method. Importantly, high-quality neuromuscular material was obtained whereby pre-, postsynaptic, and glial elements were routinely labeled, simultaneously with myosin heavy chain type I. The BeeNMJs approach will facilitate studies of NMJs, particularly in human disease or aging process.
Aging leads to a loss of muscle strength and functional capacity likely resulting from a combination of neural and muscle alterations. The aim of this study was to identify possible disparities in ...muscle strength and force development profiles in high- and low-functioning elderly men and to investigate muscular and neurophysiological factors that could explain the differences.
Sixty community-dwelling men in good general health were divided in two groups based on a functional capacity (FC) z-score derived from 6 tests of the Short Physical Performance Battery and Senior Fitness Test (Normal and fast 4m-walk tests, normal and fast Timed-up and go, chair and stair tests). Extensor strength of the lower limbs (LL) was obtained for concentric (CLES) contraction and combined with lean masses of LL (LLLM) to yield concentric (CLES/LLLM) index. Similarly, extensor strength of the right Quadriceps Femoris (IKES) was obtained during maximal voluntary isometric contraction (MVC) and combined with right thigh lean mass (rTLM) to produce an isometric strength (IKES/rTLM) index. A muscular profile was obtained from: ascending and descending force slopes during the MVC; Vastus Lateralis (VL) muscle twitches parameters (amplitude, contraction and ½ relaxation times); the knee joint velocity (KV) as well as integrated EMG (iEMG) were determined for a sit-to-stand functional evaluation; muscle phenotype. A neurophysiological profile was established from: the spinal excitability (Hmax/Mmax ratio); motoneuron conduction velocity (CV); the completeness of muscle activation (% of force reserve), median power frequency (MPF) and mean amplitude (MA) of the VL EMG signal during MVC.
Coincidently, age did not differ between groups. Strength and force indices, descending force slopes for MVC, KV and iEMG during the sit-to-stand evaluation and FC parameters were all significantly (p<0.05) lower in the LoFC group than in the HiFC group. In contrast, no difference was observed between groups in: LLLM and rTLM, Hmax/Mmax ratio, CV, twitch parameters and muscle phenotype.
The lower concentric and isometric strengths found in the LoFC group could not be accounted for by muscular factors. Similarly, peripheral nervous systems alterations could not explain group differences. It can be suggested that modifications within the central nervous system may be responsible for the differences in the functional status of healthy elderly individuals. Finally, more complex and demanding tasks, such as those requiring greater intensity or coordination, may further clarify how healthy elderly individuals with low and high functional capacities differ.
•Low-functioning elderly men had difficulty initiating a functional movement•Functional level was unrelated to muscular factors•Slower maximal force release is associated with low functional level•Central nervous system inhibition was greater for low-functioning elderly men
Gender-affirming surgery is common for the treatment of gender dysphoria, but its effect on genital sensitivity is not well known.
To investigate genital sensory detection thresholds in ...male-to-female transgender women postoperatively and their relation to psychological well-being and variables of satisfaction.
Prospective study on 28 transgender women at least 18 years old operated on at least 3 months before the study by a single surgeon (N.M.J.).
Medical complications; sensory detection thresholds for light touch, pressure, and vibration; and questionnaires on general and sexual satisfaction, sexual function, depression, and psychological well-being.
Sensory detection thresholds ranged from 0.07 to 2.82 g for light touch, with the neck being most sensitive; from 20.23 to 34.64 g for pressure, with similar results for the neck and clitoris; and from 0.0052 to 0.0111 V for vibration, with similar findings for all stimulation points. Satisfaction with the appearance of the labia, vulva, clitoris, and sexual function was good to very good. Frequency of sexual activities increased significantly postoperatively for orogenital stimulation and decreased significantly for frequency of fantasies (t = -4.81; P < .0001). Orgasmic function was reported by 80% of participants. Psychological adjustment was good to very good, with low depression scores. Sexual satisfaction was statistically and positively correlated with vaginal function and depth, clitoral sensation, appearance of the vulva and labia minora, and natural lubrication and negatively correlated with depression scores.
Gender-affirming surgery yields good results for satisfaction with appearance and function. Genital sensitivity showed the best results with pressure and vibration.
A fully coupled atmosphere–ocean–ice model has been used
to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017.
Currently, the system relies on four ...uncoupled data assimilation (DA) components
for initializing the fully coupled global atmosphere–ocean–ice forecast model:
atmosphere, ocean, sea ice and sea surface temperature (SST).
The goal of the present study is to implement a weakly coupled data assimilation (WCDA)
between the atmosphere and ocean components and evaluate its performance against uncoupled DA.
The WCDA system uses coupled atmosphere–ocean–ice short-term forecasts
as background states for the atmospheric and the ocean DA components that independently compute atmospheric and ocean analyses.
This system leads to better agreement between the coupled atmosphere–ocean analyses
and the coupled atmosphere–ocean–ice forecasts than between the uncoupled analyses and the coupled forecasts.
The use of WCDA improves the atmospheric forecast score near the surface,
but a slight increase in the atmospheric temperature bias is observed.
A small positive impact from using the short-term SST forecast
on the satellite radiance observation-minus-forecast statistics is noted.
Ocean temperature and salinity forecasts are also improved near the surface.
The next steps toward stronger DA coupling are highlighted.
Abstract
A global deterministic wave prediction system (GDWPS) is used to improve regional forecasts of waves off the Canadian coastline and help support the practice of safe marine activities in ...Canadian waters. The wave model has a grid spacing of ¼° with spectral resolution of 36 frequency bins and 36 directional bins. The wave model is driven with hourly 10-m winds generated by the operational global atmospheric prediction system. Ice conditions are updated every three hours using the ice concentration forecasts generated by the Global Ice–Ocean Prediction System. Wave forecasts are evaluated over two periods from 15 August to 31 October 2014 and from 15 December 2014 to 28 February 2015, as well as over select cases during the fall of 2012. The global system is shown to improve wave forecast skill over regions where forecasts were previously produced using limited-area models only. The usefulness of a global expansion is demonstrated for large swell events affecting the northeast Pacific. The first validation of a Canadian operational wave forecast system in the Arctic is presented. Improvements in the representation of forecast wave fields associated with tropical cyclones are also demonstrated. Finally, the GDWPS is shown to result in gains of at least 12 h of lead time.
Few studies explored multiple sensory detection thresholds on the perineum and breast, but these normative data may provide standards for clinical conditions such as aging, genital and breast ...surgeries, pathological conditions affecting the genitals, and sexual function.
The aim of this study was to provide normative data on sensory detection thresholds of three sensory modalities on the perineum and breast.
Thirty healthy women aged between 18 and 35 years were assessed on the perineum (clitoris, labia minora, vaginal, and anal margin), breast (lateral, areola, nipple), and control body locations (neck, forearm, abdomen) for three sensory modalities (light touch, pressure, vibration).
Average detection thresholds for each body location and sensory modality and statistical comparisons between the primary genital, secondary sexual, and neutral zones were the main outcome measures.
Average detection thresholds for light touch suggest that the neck, forearm, and vaginal margin are most sensitive, and areola least sensitive. No statistical difference is found between the primary and secondary sexual zones, but the secondary sexual zone is significantly more sensitive than the neutral zone. Average detection thresholds for pressure suggest that the clitoris and nipple are most sensitive, and the lateral breast and abdomen least sensitive. No statistical difference is found between the primary and secondary sexual zone, but they are both significantly more sensitive than the neutral zone. Average detection thresholds for vibration suggest that the clitoris and nipple are most sensitive. The secondary sexual zone is significantly more sensitive than the primary and neutral zone, but the latter two show no difference.
The current normative data from sensory detection threshold are discussed in terms of providing standard values for research and clinical conditions. Additional analysis from breast volume, body mass index, hormonal contraception, menstrual cycle, and sexual orientation do not seem to influence the results. Sexual abstinence and body piercing may have some impact. Cordeau D, Bélanger M, Beaulieu‐Prévost D, and Courtois F. The assessment of sensory detection thresholds on the perineum and breast compared with control body sites. J Sex Med 2014;11:1741–1748.
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