Radiation budget, ground thermal regime and hydrological balance of a low arctic tundra basin, Coppermine River, Northwest Territories

The effects of slope, aspect and vegetation cover on the radiation balance and active layer thermal regime of arctic tundra were investigated during the summer of 1999 and the spring of 2000. The study site is located at Daring Lake, N.W.T (64°52\u27N, 111°35\u27W) in the Slave Geological Province of the Coppermine River Basin. A sub-basin 14 ha in area and with approximately 30 meters of relief was intensely monitored for hydrological radiation and energy balance components. Initiation of active layer development and subsequent thawing was earlier and more pronounced on predominantly west facing slopes due to increased receipt of incoming solar radiation. Late summer active layer depths were the greatest on west-facing slopes as compared to north-and east-facing slopes (\u3e170 cm. 84.0 ±21.7 cm. 49.2 ±0.8 cm respectively). Incoming shortwave radiation values were extrapolated from the met site to various basin sites taking slope and aspect into account. Spatial and diurnal variations in albedo were minimal within the Kakawi Lake Basin. As well, surface temperature measurements varied little from site to site causing the long wave radiation balance to remain relatively constant. Incoming shortwave radiation was determined to control diurnal fluctuations in the net radiation balance on a daily and seasonal basis but represented less than one half (41%) of the radiative supply to the surface. Ground heat flux increased downslope on west- and north-facing hillslopes corresponding with an increase in active layer development during the summer season. Conversely, basal flux out of the active layer to the underlying permafrost decreased downslope. The sensible heat flux varied least with depth between the study sites but accounted for a significant proportion of the ground flux at sites with deeper active layers. Active layer depths at peat dominated, east-facing hillslope sites were only 59% of the average depth on west- and north-facing slopes primarily due to the high water content and reduced thermal conductivity of peat soils. Latent heat is largest at the beginning of the thaw season when there is rapid active layer development but is later reduced as ground thaw slackens. Kakawi Lake Basin precipitation input, outflow and lake water level were recorded daily throughout the 36 day study period while evaporation was estimated based on a study conducted in a nearby basin. Lateral inflow from catchment hillslopes was determined to the dominant component of the Kakawi Lake Basin hydrological balance for the 1999 study period. Peat dominated areas were disconnected throughout much of the study period but drained as a single source during rainfall events

A MYOELECTRIC COMPARISON OF TREADMILL AND ICE SKATING

Due to technical and logistic difficulties in conducting skating research on the ice rink surface, the skating treadmill is an excellent resource from a diagnostic and industrial perspective. However; the potential benefits of the skating treadmill hinge on the similarity of treadmill and ice skating parameters. The purpose of this study was to compare the two myoelectric profiles with regards to both temporal and amplitude measures. The findings show that despite intratester, and intersubject variability and differences in stride rate and velocity, the respective myoelectric profiles of the quadriceps and lower leg show strong similarities further indicating a specificity of conditions and gross motor function between conditions

DYNAMIC PRESSURE MEASUREMENT ABOUT THE FOOT AND ANKLE

Measures about the foot and ankle within footwear are required to assess the full dynamic interaction. To address this, piezo resistive fabric sensors provide accurate pressure measurement that can be applied within the narrow confines of the footwear-to-footlankle interface. An example of this has been shown in studies focusing on ice hockey skate boots during forward skating. Sixteen flexible piezo-resistive sensors (1.2 cm x 1.8 cm x 0.2 cm thick, FSA Verg Inc.,Canada) were taped to discrete anatomical surfaces of the plantar foot, dorsal foot, the posterior aspect of heel and leg, medial aspect of foot, and lateral aspect of the foot. The results showed an increase in pressure during the stance phase of gait at each anatomical surface with a reciprocal decrease in pressure during swing

ANKLE KINEMATICS DURING FORWARD HOCKEY SKATING: ACCELERATION TO CONSTANT VELOCITY

Kinematic measures of the foot and ankle are of relevance to footwear manufacturers and to rehabilitative professionals. Difficulties undertaking such measurements have been summarized previously (Milani & Hennig, 2000). This paper presents the kinematic profile of the ankle in both sagittal (plantar dorsi) and frontal (inversion eversion) planes. Penny & Giles electrogoniometers (Blackwood, UK / Biometrics Ltd.) collected data from 5 elite subjects at 1000 Hz. Similar kinematic profiles were observed between 3 accelerating strides and constant velocity strides. Despite the absence of significant differences between strides there was a trend for increased range of motion at the ankle as the skaters accelerated to a high velocity

THE EFFECT OF ACCLIMATIZATION TO THE SKATING TREADMILL

The development of the skating treadmill has enabled researchers to investigate the movement patterns of the forward power skating stride in a controlled environment. It has the potential to aid not only researchers but also coaches, traineJs and therapists leading to an end result of improving the overall performance of the athletes themselves. Studies have investigated biomechanical and physiological parameters of forward skating on the skating treadmill. Turcotte et al. (2004) compared plantar forces distribution patterns of on-ice skating to treadmill skating and discovered significantly elevated levels at heel strike. Hinrich (1994) performed a study comparing on/oH muscle activation patterns and concluded that the skating treadmill accurately replicates on-ice skating. Both these studies failed to use a familiarization period to allow the subjects to acclimatize themselves to skating on the polyethylene tiles. Nobes et al. (2003) did use three, thirty minute bouts to allow for acclimatization and noted differences in submaximal V02, HR and stride rate when treadmill skating was compared to on-ice skating. It is unknown if an acclimatization period has an effect on biomechanical or physiological parameters. Thus, the purpose of this study is to determine whether an acclimatization period has eHects on 02 consumption, muscle activation pattems and kinematics

THE ICE HOCKEY SLAP SHOT, ELITE VERSUS RECREATIONAL

Stationary ice hockey slap shots performed by five elite and five recreational players were compared. Each hockey player performed 5 shots. Three-dimensional kinematics of the stick and upper body were recorded using an electromagnetic tracking device, the Ultratrak®, (Polhemus Inc., Burlington, VT, USA). Joint centers were calculated using the sphere fitting method. Elite players shot significantly faster than recreational players (29.14 ± 1.39 m/s and 26.46 ± 0.66 m/s). Velocity due to translation movement was greater for recreational players compared to novice players (13.14 m/s and 908 m/s). Investigation in maximal angular velocities of the body movement sequences indicated that elite players' maximal velocities moved from the core to the extremities where as recreational players exhibited no such pattern. The results of this study suggested that there are differences in technique when performing the stationary slap shot which may contribute to the increased performance of the ice hockey slap shot

QUANTIFYING FIT IN ICE HOCKEY SKATE BOOTS

Skates are specifically designed for the hockey game context. It is vital that skates be chosen in relation with proper size and shape, as well as with respect to play style and position (Pearsall et al. 2000). To provide optimal function, they must "fit". Fit infers many traits: to fit snugly around the contours of the bony ankle and foot structures, to provide stability, and to avoid discomfort. Nonetheless, players have often sacrificed "fit for comfort" at the expense of "fit for performance". Comfort and fit are interrelated qualities and important factors for footwear in recreational and physical activities. Increasing interest in footwear comfort resulted in several investigations that associated comfort with plantar pressure distribution (Chen et al.1994). To date, improved ratings for shoes comfort can be done by adding a control condition to the testing protocol and using a visual analog scale (VAS) to assess comfort (Mundermann et al. 2002). Little have been done in assessing fit in ice hockey boots. The purpose of this study is to quantify fit in the ice hockey skate boots by means of pressure distribution measures in conjunction with perceptual VAS ratings

Home Interventions for Older Adults with Asthma

Older asthmatic adults are more likely to experience respiratory failure than younger adults and children with asthma. Older adults spend up to 90% of their time in the home where many allergens are found. While there is sufficient evidence that home interventions improve the health of asthmatic children, there is insufficient evidence for the effectiveness of home interventions with adults. Our research evaluates the hypothesis that multi-trigger, multifaceted home interventions improve respiratory health and reduce home asthma triggers for older adults. Methods: We evaluated the effectiveness of conducting interventions in the homes of 86 diverse, low-income older adults (age 62 or above) diagnosed with asthma, residing in public and private subsidized housing. The two largest populations include Hispanics (45%) and Asians (20%). Data was collected on respiratory health outcomes before and after the home intervention (questionnaires on symptoms, quality of life, medication use, doctor/ER/hospital visits, and exhaled nitric oxide (eNO) a measure of lung inflammation). Asthma trigger activities (ATAs) and exposures were also evaluated before and after the home intervention (questionnaire, home survey, measurement of nitrogen dioxide (NO2), dust samples for rodent and cockroach allergens, biomarker for cigarette smoke exposure (urinary cotinine). Interventions included education on asthma and environmental triggers; environmental remediation including mattress/pillow covers, provision of vacuum with HEPA filters, green cleaning supplies and changes in home as needed (commercial cleaning, integrated pest management, gas stove replacement, mold remediation). Results: Significant health improvements were found in the following areas: number of doctor visits due to asthma, quality of life indicators including symptom and activity levels, and asthma control test

Acute and chronic post-surgical pain after living liver donation: Incidence and predictors

Despite its prominence as a concern among potential surgical candidates, there is little information in the literature regarding the short- and long-term pain experience after living liver donation. We undertook a prospective study to examine (1) the nature and incidence of acute and chronic pain after living donor hepatectomy and (2) the factors associated with an increased or decreased risk of adverse pain outcomes. Before donation, a comprehensive assessment of potential predictors of acute and chronic pain outcomes was conducted; this included donors’ pain expectations, psychosocial factors, medical histories, and demographic factors. Detailed data regarding pain outcomes were collected postoperatively (days 1 and 2) and again during 6- and 12-month follow-up telephone interviews. Sixty-five adults (32 females and 33 males) scheduled for donor hepatectomy participated. Substantial proportions of the donors reported a moderate-to-severe level of pain intensity (4 on a 0-10 scale) at rest and after movement on day 1 (42% and 74%, respectively) and day 2 (33% and 32%, respectively). Persistent postsurgical pain was reported by 31% of the donors at the 6-month follow-up and by 27% of the donors at the 12-month follow-up. Generally, this pain was mild, and pain-related life interference was minimal. Female sex, a younger age, and several predonation measures of pain-related anxiety were associated with a significantly greater risk of developing persistent postsurgical pain. In conclusion, this study has identified a subset of patients who experience persistent pain after living liver donation. Additional prospective research using larger samples of liver donors is needed to replicate this work, to obtain a more detailed account of the acute and long-term pain experience, and to determine whether targeted interventions can minimize the frequency and severity of chronic pain.Hance A. Clarke is supported by a merit award from the Department of Anesthesia at the University of Toronto and by the Strategic Training for Advanced Genetic Epidemiology program at the Canadian Institutes of Health Research. Joel Katz is supported as a Canadian Institutes of Health Research Canada Research Chair in Health Psychology at York University

MR447: Seasonal Water Table and Temperature Relationships in Calcareous Till and Residual Soils of Central Maine

Water table depths and soil temperatures were monitored for four growing seasons in six calcareous till pedons developed on gently rolling to level till plains in Corinth and Exeter, Maine. These soils are part of a new catena that supports potato production in southeastern Penobscot County. Three of these coarse-loamy to fine-loamy pedons are moderately well drained Oxyaquic Eutrudepts taxadjuncts in potato fields, and three are somewhat poorly drained Aquic Dystric Eutrudepts in predominantly deciduous forest. Soil morphology, hydrologic data, and a,a dipyridyl applications support the described subgroup classification of each pedon, along with the udic moisture regime. Despite a smooth, glaciated landscape that would suggest the presence of extensive lodgment till, five observation sites lacked a densic contact and one contained residuum (saprolite) in the substratum. Apparent water tables in the SPD very deep soils, as well as oxyaquic hydrology in the deep soils on 0 to 3 percent slopes, suggest the more permeable subglacial melt-out till predominating, rather than lodgment till in all of these pedons. Growing season concepts were compared based on frost-free season at 0 and -2.2° C thresholds, soil temperatures in the plow layer, soil temperature at 50 cms and well-water temperature. The commencement of the growing season in the spring did not differ much across all five concepts. However, in the fall there was a 4- to 8-week lag between the air or shallower soil-temperature growing-season concepts and the deeper soil or well-water-temperature growing-season concepts. Daytime air temperature during the first 2 years of monitoring differed significantly between spring and fall seasons, but not between field and forest sites within each season.https://digitalcommons.library.umaine.edu/aes_miscreports/1027/thumbnail.jp