These studies investigated the impact of intensity and body temperature on performance and cardiovascular regulation during high intensity and prolonged exercise. In study 1, polyphenol antioxidant supplementation proved to have no effect on exercise performance and related variables (gross efficiency, perceived exertion, maximal power) during exercise in the heat. Furthermore, there were no differences between the cardiovascular or thermoregulatory responses between control and antioxidant treatments. Study 2 utilized an integrative approach to investigate a classic topic in exercise physiology, namely, is the cardiac output to oxygen consumption relationship linear across a wide range of exercise intensities? The slope of the CO vs. VO2 relationship was significantly reduced from 70 to 100% of VO2max when compared to the slope from 40 to 70% of VO2max (2.0 ± 0.4 vs. 4.4 ± 0.3 l/min, p = 0.025). This finding, in combination with the plateau and eventual reduction in stroke volume at high intensity exercise compared to moderate intensity exercise (146.0 ± 16.6 vs. 138.5 ± 14.9 ml/beat, p = 0.015), argues in favor of a cardiac limitation to high intensity exercise. This study also showed that the pattern of oxygen extraction at the whole body level (arterial venous O2 difference) and the muscle level (deoxygenated hemoglobin) is not similar and that muscle specific differences exist regarding oxygen extraction. Study 3 determined that hyperthermia (elevation of skin temperature by 4.3°C and core temperature by 0.8°C) did not reduce SV independent of the increase in HR. Even under conditions of moderate hyperthermia the reduction in SV is due to the increase in HR and temporally unrelated to increases in cutaneous blood flow. In summary, antioxidant supplementation had no effect on performance, cardiovascular, or thermoregulatory responses to exercise in the heat in well trained subjects. High intensity exercise is associated with a reduced rate of increase in the CO vs. VO2 relationship. Finally, hyperthermia does not reduce SV during exercise when HR is maintained at normal levels. / text

Tall fescue (Lolium arundinaceum) is the principal cool-season species within pastures of the southeastern USA and is known to have a mutualistic relationship with a fungal endophyte (Neotyphodium coenophialum) that produces the ergot alkaloids responsible for tall fescue toxicosis. Management of the reproductive growth of tall fescue is necessary, as the seedheads contain the highest concentrations of ergot alkaloids, and livestock have been documented to selectively graze these tissues. Recently, the herbicide Chaparral™ has been shown to be an effective method to prevent seedhead production in tall fescue pastures while also increasing steer gains at a low stocking rate. The objective of this study was to compare the impact of Chaparral on steer and pasture production under multiple grazing intensities (GI). Chaparral (0 and 140 g ha-1) and two levels of GI (low: 3300±250 kg ha-1 & moderate: 2500±250 kg ha-1) treatments were arranged in a factorial combination as RCBD with three replications. Tall fescue seedhead densities were decreased (P < 0.05) within the Chaparral-treated pastures, but efficiency of the inhibition varied slightly between growing seasons. Chaparral-treated pastures had lower (P < 0.05) forage availabilities and contained forage with higher (P < 0.05) concentrations of crude protein (CP) and in vitro digestible dry matter (IVDDM) during both growing season. Steers within the Chaparral-treated pastures and low GI treatment had higher average daily gains (ADG). Carrying capacities (CC) were lowest and highest within the Chaparral-low GI and control-moderate GI treatments, respectively. Estimates of CC were not different (P > 0.15) between the Chaparral-moderate GI and control-low GI treatments. The higher ADG compensated for the lower CC of the Chaparral and low GI treatments and resulted in no difference (P > 0.60) in total gain per hectare (GPH) between grazing intensities and herbicide treatments in 2011. In 2012, the GPH were higher within the control and moderate GI treatments due to a lessening in the magnitude of difference between the herbicide and GI treatments. The effects of these treatments for alleviating symptoms of tall fescue toxicosis were inconclusive due to the low levels of ergot alkaloids production.

Laikant bulves storame 5 – 6 m storio sluoksnyje, aruode sunku likviduoti susidariusius gedimo židinius. Židinio pašalinimui būtina suintensyvinti ventiliavimą, kad mumifikuoti gedimo židinyje esančius sugedusius gumbus. Tyrimų tikslas - ištirti ventiliuojamo oro paskirstymo dėsningumus bulvių sandėlio sampile ir eksperimentiniame oro paskirstymo stende. Nustatyti oro paskirstymą ventiliuojamame sampile, keičiant skirstomųjų ortakių skaičių, bei ištirti ventiliavimo suintensyvinimo galimybes susidarančias gedimo zonoje. Nustatyta, kad sumažinus atidarytų skirstomųjų ortakių skaičių, galima padvigubinti ventiliavimo intensyvumą likusiuose atidarytuose ortakiuose. Esant atidarytam vienam skirstomajam ortakiui, tiekiamas 8,34 /s oro srautas. Atidarius visus aštuonis ortakius, į kiekvieną ortakį tiekiama tik 3,9 /s oro. Šalia židinio esantys produkcijos sluoksniai bus ventiliuojami žymiai mažesniu ventiliavimo intensyvumu, kas sumažina produkcijos perventiliavimo galimybes likviduojant gedimo židinį sandėlio aruode. / Holding potatoes in a thick 5-6 m layer in the bin it is difficult to eliminate originated hot spots. To remove the source it is necessary to intensify ventilation in order to mummify defective tubers in corruption source. The aim of the research is to investigate the patterns of ventilated air distribution in potato store and distribution of air in an experimental bench. To determine air distribution in ventilated store by changing the number of distribution ducts, and to explore opportunities to intensify ventilation arising in corruption area. It was found that reducing the number of opened distribution ducts the intensity of the ventilation in the remaining opened ducts can be doubled. At the invitation of one ducts supplied 8.34 m3/s air flow. After opening all eight ducts, each duct to be supplied only 3.9 m3/s in air. The layers next to the source will be ventilated with much smaller intensity, which decreases possibility to over ventilate production while eliminating corruption source in the store bin.

Darbo objektas: motorinės sistemos nuovargio reakcija į skirtingo intensyvumo vienkartinį fizinį krūvį. Darbo tikslas: nustatyti didelio ir mažo intensyvumo fizinio krūvio poveikį paauglių motorinės sistemos nuovargiui. Uždaviniai: 1. Nustatyti paauglių maksimalios valingos jėgos (MVJ) ir kūno pusiausvyros pokyčius prieš didelio ir mažo intensyvumo fizinį krūvį. 2. Nustatyti paauglių MVJ ir kūno pusiausvyros pokyčius po didelio intensyvumo fizinio krūvio. 3. Nustatyti paauglių MVJ ir kūno pusiausvyros pokyčius po mažo intensyvumo fizinio krūvio. 4. Palyginti paauglių MVJ ir pusiausvyros pokyčius po didelio ir mažo intensyvumo fizinio krūvio. Tyrimo hipotezė: didelio intensyvumo fizinis krūvis turėtų sukelti didesnį motorinės sistemos nuovargį nei mažo intensyvumo fizinis krūvis. Išvados: 1. Paauglių MVJ po mažo bei didelio intensyvumo fizinio krūvio statistiškai reikšmingai nepakito. 2. Mažo intensyvumo fizinis krūvis neturėjo įtakos paauglių kūno pusiausvyros svyravimo rezultatams. 3. Po didelio intensyvumo fizinio krūvio statistiškai reikšmingai pakito kūno pusiausvyros amplitudės svyravimai. 4. Pauglių MVJ po didelio ir mažo intensyvumo fizinio krūvio nepakito, tačiau didelio intensyvumo fizinis krūvis turėjo įtakos paauglių pusiausvyrai. / The object: effect of single different physical load on motor system fatigue. The aim: determine the effect of high and low intensity exercise on adolescent motor system fatigue. The following tasks: 1. Determine adolescent maximum voluntary contractions (MVC) and balance before physical load. 2. Determine adolescent MVC and balance after high intensity exercise. 3. Determine adolescent MVC and balance after low intensity exercise. 4. Compare adolescent MVC and balance after high and low intensity exercise. Hypothesis of the research: high intensity exercise causes bigger fatigue of motor system than low-intensity exercise. Conclusions: 1. Adolescent MVC did not change significantly after high and low intensity exercise. 2. Low intensity exercise had no impact on adolescent balance sway results. 3. Adolescent balance sway had change significantly after high intensity exercise. 4. Adolescent MVC did not change after any of physical load, but high intensity exercise had impact on adolescent balance sway results.

This thesis details an experimental study on the determination of the fracture parameters for a crack located at the interface between two dissimilar materials using the method of photoelasticity. The interface is potential1y an inherent weak spot of any composite material, structure"or adhesively bonded joint. Accurate description of the state of stress at the crack tip is required for strength prediction. The concept of the complex stress intensity factor is used to characterise the elastic crack tip stress field for an interface crack. Complex stress intensity factors and their moduli have been measured experimental1y for standard bimaterial crack geometries using the wel1 established technique of photo elasticity. Bimaterial specimens comprising aluminium al10y and epoxy resin components were used. This creates a large material mismatch at the interface and al10ws data to be col1ected from the epoxy component of the specimen using transmission photoelasticity. An automated ful1 field photoelastic technique was developed to significantly reduce the data col1ection time. The technique comprises elements from the approaches of three wavelength and phase stepping photoelasticity and is a significant improvement on techniques previously available. Stress intensity factors were determined by fitting a theoretical stress field solution for the bimaterial crack to the experimental data. A computational routine automatical1y selects the region of best fit between the experimental data and the theoretical solution. This data is then used to determine the complex stress intensity factor and its modulus value. In order to provide a robust fit between the experimental data and the theoretical field solution a weighting function was incorporated into the routine. The measured bimaterial stress intensity factors are compared with those determined experimental1y for equivalent homogeneous specimens made from epoxy resin. The differences between the two are then discussed. The experimental results agree with the wel1 known concept that tension and shear effects are inherently coupled at the crack tip. However, the effects of changing the load angle with respect to the interface also demonstrate that some contrasts exist with known numerical solutions.

Cities are often warmer than their surroundings, and this can lead to more energy being used to cool buildings. This study looks at one city, London, and assesses the impact of the urban environment on the amount of energy used for air-conditioning. There are three main strands to the work. First, it was important to determine just how great the variation in air temperature is, and how this varies through time and through the urban space. Eighty measurement stations were established along radiating lines from the centre of London as far as rural areas. These measured the air temperature simultaneously at hourly intervals for over a year. Second, to support the main data acquisition, short-term tests within London looked at specific aspects of the urban environment that affect air temperature: the effects of vegetation in parks, and facade colour in streets. Third, the impact on energy use of the measured temperature variation was then determined by using simulation to model a standard building in different urban contexts. The mean heat island intensity was found to vary with distance from the centre of London, and with the local degree of urbanization at any given distance. The maximum intensity reached 8°C on occasion but was more usually 1-2°C in the daytime and 3-4°C at night. The proximity of areas of vegetation, such as parks, to a site was associated with cooler daytime temperatures. The annual cooling load for a standard building at the centre of London was found to be 25% more than at a rural site. However, at the most urban sites over-shadowing reduced the cooling load to 14% more than at a rural site. Heating load decreased towards the centre, but on balance total annual load (for heating and cooling) rose towards the centre to 8.5% more than rural use, and then reduced at the most overshadowed sites. The balance of the effect of urbanization on heating and cooling load depended on the level of internal gain in the building. This study makes a significant contribution to understanding the balance of the impact of urban environments on the energy used for cooling and heating buildings.

The wall properties of the arteries play an important role in cardiovascular function. Stiffness of large artery is predictive of cardiovascular events. To understand the function of the cardiovascular system, special attention should be paid to the understanding of pulse wave propagation, because pulse waves carry information of the cardiovascular function, and provide information which can be useful for the prevention and diagnosis of diseases. This thesis presents a series of in vitro experimental studies of wave propagation, wave reflection and determination of mechanical properties of flexible vessels. In this thesis, several studies have been included: 1) applied and compared foot-to-foot, PU-loop and lnDU-loop methods for determination of wave speed in flexible tubes and calf aortas; 2) investigated the variation of local wave speed determined by PU-loop with proximity to the reflection site; 3) investigated using wave intensity analysis (WIA) as the analytical technique to determine the reflection coefficient; 4) developed a new technique which based on one-point simultaneous measurements of diameter and velocity to determine the mechanical properties of flexible tubes and calf aortas. In the first study, it is found wave speeds determined by PU-loop and lnDU-loop methods are very similar, and smaller than those determined by foot-to-foot method. The timing of arrival time of reflected wave based on diameter and velocity technique highly agreed with the corresponding timing based on pressure and velocity technique. The shapes of forward and backward non-invasive wave intensities based on diameter and velocity are very similar with the corresponding shapes based on pressure and velocity. Although the density term is not part of the equation, the lnDU-loop method for determining local wave speed is sensitive to the fluid density. In the second study, it is found wave speed measured by PU-loop is varied with proximity to the reflection site. The closer the measurement site to the reflection site, the greater the effect upon measured wave speed; a positive reflection caused an increase in measured wave speed; a negative reflection caused a decrease in measured wave speed. Correction iteration process was also considered to correct the affected measured wave speed. In the third study, it is found, reflection coefficient determined by pressure, square roots of wave intensity and wave energy are very close, but they are different from reflection coefficient determined by wave intensity and wave energy. Due to wave dissipation, the closer the measurement site to the reflection site, the greater is the value of the local reflection coefficient. The local reflection coefficient near the reflection site determined by wave intensity and wave energy are very close to the theoretical value of reflection coefficient. In the last study I found that distensibility determined by the new technique which utilising lnDU-loop is in agreement with that determined from the pressure and area which obtained from tensile test in flexible tubes; distensibility determined by the new technique is similar to those determined in the static and dynamic distensibility tests in calf aortas; Young’s modulus determined by the new technique are in agreement with that those determined by tensile tests in both flexible tubes and calf aortas. In conclusion, wave speed determined by PU-loop and lnDU-loop methods are very similar, the new technique lnDU-loop provides an integrated noninvasive system for studying wave propagation; wave speed determined by PU-loop is affected by the reflection, the closer the measurement site to the reflection site, the greater the change in measured wave speed; WIA could be used to determine local reflection coefficient when the measurement site is close to the reflection site; the new technique using measurements of diameter and velocity at one point for determination of mechanical properties of arterial wall could potentially be non-invasive and hence may have advantage in the clinical setting.

Using a correlational design, this study examined relationships among and between differentiation, profile elevation, gender and educational level (predictors) and depression, confidence, and vocational identity (criterion). Clients presenting for counseling services (n = 90) with a career concern at a large, metropolitan university were included in the study. Six assumptions were examined using three single hierarchical regression analyses to reveal relationships among and between variables. Two research assumptions were confirmed at the .05 level of significance. Bivariate correlations were computed to examine the structure coefficients. Beta weights and structure coefficients were examined to determine the relative contribution of the predictors in the regression model. Results indicated that differentiation, profile elevation, gender and educational level did not predict significant variance in depression and vocational identity. However, differentiation, profile elevation, and educational level did significantly predict confidence (p< .0001).

The “stage model” is a criticized but well-used segmentation method for categorizing firms into different export development stages based on their perceived export barriers. However increasing presence of born global firms and lagging exports, particularly in the Swedish tech industry, require an updated segmentation tool. Export intensity, export experience and psychic distance to foreign customers are identified as alternative indicators of a firm’s perceived export barriers. The extent to which these variables can predict perceived export barriers of firms is tested. Collected data from 30 Swedish SMEs consisting of both born globals and traditional exporters within the tech field suggest that none of the three variables is a sufficient indicator of perceived export barriers on its own. Instead, each variable explains different export barriers to different degrees. The results indicate that each SME chooses its unique path of export development, making it difficult to establish a standardized stage model for modern SMEs.

Whilst high levels of cardiorespiratory fitness and physical activity may protect against cardiometabolic risk factor clustering, evidence suggests these outcomes are below optimal in English youths. Adolescence is a key stage in health behaviours development, and thus represents an opportunity for interventions aiming to improve the cardiometabolic health, fitness and activity levels of this population. Recently, there has been growing interest in the efficacy of low-volume high-intensity interval training (HIT) as a time efficient way of improving health and fitness outcomes in adults. Contrastingly, the effects of low-volume HIT in adolescents remains relatively unknown. The first aim of this programme therefore was to develop a novel school-based low-volume HIT intervention. The second was to determine the effectiveness of this model for improving the cardiometabolic health, cardiorespiratory fitness and physical activity levels of adolescents. Study one examined adolescents’ views towards high-intensity exercise, and the proposed low-volume HIT intervention. This data was used to design the novel low-volume HIT model. In Study 2, participants’ heart rate and perceived exertion responses to three prototype prescriptions of low-volume HIT, based on boxing, dance and football were examined. Here, it was indicated that these activities were capable of eliciting a high-intensity training response (~90% of maximum heart rate). Study 3 incorporated the main intervention, which examined the effect of a 10-week multi-activity low-volume HIT intervention (named Project FFAB [Fun Fast Activity Blasts]) on various health and fitness outcomes in adolescents. Here, beneficial effects were detected in the intervention participants compared to the controls for triglycerides, waist circumference, lipid accumulation product and daily moderate-to-vigorous physical activity. Study 4 assessed the fidelity of the intervention, and found that this had been largely upheld. Collectively therefore, it appears that Project FFAB represents a viable strategy for improving aspects of cardiometabolic health and physical activity levels in adolescents.