862 resultados para average distance
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Coal contains trace elements and naturally occurring radionuclides such as 40K, 232Th, 238U. When coal is burned, minerals, including most of the radionuclides, do not burn and concentrate in the ash several times in comparison with their content in coal. Usually, a small fraction of the fly ash produced (2-5%) is released into the atmosphere. The activities released depend on many factors (concentration in coal, ash content and inorganic matter of the coal, combustion temperature, ratio between bottom and fly ash, filtering system). Therefore, marked differences should be expected between the by-products produced and the amount of activity discharged (per unit of energy produced) from different coal-fired power plants. In fact, the effects of these releases on the environment due to ground deposition have been received some attention but the results from these studies are not unanimous and cannot be understood as a generic conclusion for all coal-fired power plants. In this study, the dispersion modelling of natural radionuclides was carried out to assess the impact of continuous atmospheric releases from a selected coal plant. The natural radioactivity of the coal and the fly ash were measured and the dispersion was modelled by a Gaussian plume estimating the activity concentration at different heights up to a distance of 20 km in several wind directions. External and internal doses (inhalation and ingestion) and the resulting risk were calculated for the population living within 20 km from the coal plant. In average, the effective dose is lower than the ICRP’s limit and the risk is lower than the U.S. EPA’s limit. Therefore, in this situation, the considered exposure does not pose any risk. However, when considering the dispersion in the prevailing wind direction, these values are significant due to an increase of 232Th and 226Ra concentrations in 75% and 44%, respectively.
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This paper presents an ankle mounted Inertial Navigation System (INS) used to estimate the distance traveled by a pedestrian. This distance is estimated by the number of steps given by the user. The proposed method is based on force sensors to enhance the results obtained from an INS. Experimental results have shown that, depending on the step frequency, the traveled distance error varies between 2.7% and 5.6%.
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Paper presented at Geo-Spatial Crossroad GI_Forum, Salzburg, Austria.
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Every spring, workers of the Argentine Ant Linepithema humile kill a large proportion of queens within their nests, Although this behaviour inflicts a high energetic cost oil the colonies, its biological significance has remained elusive so far. An earlier study showed that the probability of a queen being executed is not related to her weight, fecundity, or age. Here we test the hypothesis that workers collectively eliminate queens to which they are less related, thereby increasing their inclusive fitness. We found no evidence for this hypothesis. Workers of a nest were on average not significantly less related to executed queens than to surviving ones. Moreover, a population genetic analysis revealed that workers were not genetically differentiated between nests. This means that workers of a given nest are equally related to any queen in the population and that there can be no increase in average worker-queen relatedness by selective elimination of queens. Finally, our genetic analyses also showed that, in contrast to workers, queens were significantly genetically differentiated between nests and that there was significant isolation by distance for queens.
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Los sedimentos submarinos colectados a fines de setiembre 2004 a profundidades <50 m, al sur de la desembocadura del río Sama (18°10’S), fueron predominantemente arenosos (>60%). El mayor contenido de la fracción fina, de limo y arcilla (±35%), se ubicó en las zonas más profundas del área en estudio y en los extremos norte (frente a Cerro Cortado) y al sur (Los Palos), que incluyen también zonas de menor profundidad. En la zona central, la pendiente tiene la mayor inclinación de toda la zona estudiada, y el tamaño promedio del grano del sedimento es más grande; estas condiciones constituyen un reflejo de la mayor energía hidrodinámica que existe. En la zona central también se observa la típica disminución del tamaño de grano, según se incrementa la profundidad y la lejanía de la línea de costa. La distribución de materia orgánica mostró tendencia similar a la de fracción fina, con un máximo de 5,02%.
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Los resultados de investigación sobre producción primaria dentro del alcance interdisciplinario del ambiente marino frente a la costa peruana incluyen estudios nacionales, extranjeros y de investigación conjunta a través de proyectos internacionales (1960-2000). La circulación en la costa peruana es dominada por una corriente hacia el ecuador en una capa de 20 a 50 m. La estructura de plumas del afloramiento se presenta en cada área y podría ser la clave para el desarrollo de cadenas cortas y productivas: fitoplancton peces clupeidos. La distribución de nutrientes sigue la pluma de temperatura, con altos valores en la costa y bajos lejos de la costa; la clorofila muestra mínimos valores cerca de la costa (10 mn) que se incrementa al alejarse. El crecimiento del fitoplancton en aguas peruanas, varía de 0,5 a 0,8 d/d. En aguas recién afloradas el crecimiento es limitado por falta de “condicionamiento biológico” y de compuestos orgánicos (15°S). Estos tipos de agua pueden estar relacionados con las “aguas azules” de altos nutrientes y pobre fitoplancton con células de pequeño tamaño (clorofila <2 μg/L) y con “aguas marrones” con denso fitoplancton, (clorofila >5 μg/L), mayor diversidad y con células de diámetro >5μ. La media de producción primaria fue 3 gC/m2/d (1960-1985), comparable a la mayoría de estudios en los cuales varía entre 3 y 4 gC/m2/d en la franja costera, el último valor es altamente variable en espacio, siendo más frecuente dentro de 10 km. Valores mayores de 12 gC/m2/d se encontraron en el afloramiento de Chimbote. El Niño, La Niña y fases del ENSO, afectan la producción primaria. Las temperaturas bajas originan cambios en la composición química del fitoplancton y reducen el índice de productividad mgC/mgclor-a/d que también es atribuido a limitaciones de luz.
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Predicting progeny performance from parental genetic divergence can potentially enhance the efficiency of supportive breeding programmes and facilitate risk assessment. Yet, experimental testing of the effects of breeding distance on offspring performance remains rare, especially in wild populations of vertebrates. Recent studies have demonstrated that embryos of salmonid fish are sensitive indicators of additive genetic variance for viability traits. We therefore used gametes of wild brown trout (Salmo trutta) from five genetically distinct populations of a river catchment in Switzerland, and used a full factorial design to produce over 2,000 embryos in 100 different crosses with varying genetic distances (FST range 0.005-0.035). Customized egg capsules allowed recording the survival of individual embryos until hatching under natural field conditions. Our breeding design enabled us to evaluate the role of the environment, of genetic and nongenetic parental contributions, and of interactions between these factors, on embryo viability. We found that embryo survival was strongly affected by maternal environmental (i.e. non-genetic) effects and by the microenvironment, i.e. by the location within the gravel. However, embryo survival was not predicted by population divergence, parental allelic dissimilarity, or heterozygosity, neither in the field nor under laboratory conditions. Our findings suggest that the genetic effects of inter-population hybridization within a genetically differentiated meta-population can be minor in comparison to environmental effects.
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Comparer aussi, Cat. imp., liv. 106, f. 21 (Xin fa suan shu, 100 livres).Publiée par ordre impérial avant 1644, par Xu Guang qi et le P. Terenz (1576-1630).
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This study examined relationships among physical activity, body fat and salivary immonoglobulin A (sIgA) levels in adolescent children of Southern Ontario. Gender differences on these factors were also assessed. Sixty-one grade-five students (10-1 lyrs), males (n=29) and females (n=31), who had not received a flu vaccination in the past 12 months, participated in the study. They were assessed for: aerobic power (20-m shuttle run), relative body fat (bioelectrical impedance analysis), sIgA, sIgA/albumin ratio, and salivary Cortisol. Each subject completed the Habitual Activity Estimation Scale and the Participation Questioimaire. Students wore a pedometer for 48h to estimate their average total distance traveled per day. The results show 40% of the children were over 25% body fat and 50% of them spend less than five hours per day in any physical activities. Salivary IgA was not related to salivary Cortisol, physical activity, fitness level or body fat in this age group. There were no gender differences in sIgA and Cortisol levels. Boys had a significantly higher aerobic power and daily distance traveled, but reported similar organized and fi-ee time activity participation levels as the girls. The test-retest reproducibility for salivary Cortisol was 0.663 (p<0.01), while long term sIgA and sIgA/albumin ratio reproducibility was non-significant for repeated measurements taken after six weeks. It was found that salivary IgA has not been shovm to be a stable measure in children, in contrast to the results found in the literatiu-e that tested adults and the relationship with physical activity, fitness level and body fat.
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This study examined factors contributing to the differences in left ventricular mass as measured by Doppler echocardiography in children. Fourteen boys (10.3 ± 0.3 years of age) and 1 1 girls (10.5 ± 0.4 years of age) participated in the study. Height and weight were measured, and relative body fat was determined from the measurement of skinfold thickness according to Slaughter et al. (1988). Lean Body Mass was then calculated by subtracting the fat mass from the total body mass. Sexual maturation was self-assessed using the stages of sexual maturation by Tanner (1962). Both pubic hair development and genital (penis or breast for boys and girls respectively) development were used to determine sexual maturation. Carotid Pulse pressure was assessed by applanation tomometry in the left carotid artery. Cardiac mass was measured by Doppler Echocardiography. Images of cardiac structures were taken using B-Mode and were then translated to M- Mode. The dimensions at the end diastole were obtained at the onset of the QRS complex of the electrocardiogram in a plane through a standard position. Measurements included: (a) the diameter of the left ventricle at the end diastole was measured from the septum edge to the endocardium mean border, (b) the posterior wall was measured as the distance from to anterior wall to the epicardium surface, and (c) the interventricular septum was quantified as the distance from the surface of the left ventricle border to the right ventricle septum surface. Systolic time measurements were taken at the peak of the T-wave of the electrocardiogram. Each measurement was taken three to five times before averaging. Average values were used to calculate cardiac mass using the following equation (Deveraux et al. 1986). Weekly physical activity metabolic equivalent was calculated using a standardize activity questionnaire (Godin and Shepard, 1985) and peakV02 was measured on a cycloergometer. There were no significant differences in cardiovascular mesurements between boys and girls. Left ventricular mass was correlated (p<0.05) with size, maturation, peakV02 and physical activity metabolic equivalent. In boys, lean body mass alone explained 36% of the variance in left ventricular mass while weight was the single strongest predictor of left ventricular mass (R =0.80) in girls. Lean body mass, genital developemnt and physical activity metabolic equivalent together explained 46% and 81% in boys and girls, respectively. However, the combination of lean body mass, genital development and peakV02 (ml kgLBM^ min"') explained up to 84% of the variance in left ventricular mass in girls, but added nothing in boys. It is concluded that left ventricular mass was not statistically different between pre-adolescent boys and girls suggesting that hormonal, and therefore, body size changes in adolescence have a main effect on cardiac development and its final outcome. Although body size parameters were the strongest correlates of left ventricular mass in this pre-adolescent group of children, to our knowledge, this is the first study to report that sexual maturation, as well as physical activity and fitness, are also strong associated with left ventricular mass in pre-adolescents, especially young females. Arterial variables, such as systolic blood pressure and carotid pulse pressure, are not strong determinants of left ventricular mass in this pre-adolescent group. In general, these data suggest that although there is no gender differences in the absolute values of left ventricular mass, as children grow, the factors that determine cardiac mass differ between the genders, even in the same pre-adolescent age.
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The purpose of the study was to investigate the effect of skate blade radius of hollow (ROH) on anaerobic performance, specifically during the acceleration and stopping phases of an on-ice skating test. Fifteen, male Junior B hockey players (mean age 19 y ± 1.46) were recruited to participate. On-icc testing required each participant to complete an on-ice anaerobic performance test [Reed Repeat Skate (RRS)) on three separate days. During each on-ice test, the participant's skate blades were sharpened to one of three, randomly assigned, ROH values (0.63 cm, 1.27 cm, 1.90 cm). Performance times were recorded during each RRS and used to calculate anaerobic variables [anaerobic power (W), anaerobic capacity (W), and fatigue index (s, %)). Each RRS was video recorded for the purpose of motion analysis. Video footage was imported into Peak Motus™ to measure kinematic variables of the acceleration and stopping phases. The specific variables calculated from the acceleration phase were: average velocity over 6 m (m/s), average stride length (m), and mean stride rate (strides/s). The specific variables calculated from the stopping phase were: velocity at initiation of stopping (rn/s), stopping distance (m), stopping time (s). A repeated measures ANOV A was used to assess differences in mean performance and kinematic variables across the three selected hollows. Further analysis was conducted to assess differences in trial by trial performance and kinematic variables for all hollows. The primary findings of the study suggested that skate blade ROH can have a significant effect on kinematic variables, namely stride length and stride rate during the acceleration phase and stopping distance and stopping time during the stopping phase of an on-ice anaerobic performance test. During the acceleration phase, no significant difdifferences were found in SR and SL across the three selected hollows. Mean SR on the 1.27 cm hollow was significantly slower than both the 0.63 cm and 1.90 cm hollows and SL was significantly longer when skating on the 1.27 cm hollow in comparison to the 1.90 cm hollow. During the stopping phase, stopping distance on the 0.63 cm hollow (4.12 m ± 0.14) was significantly shorter than both the 1.27 cm hollow (4.43 m ± 0.08) (p < 0.05) and the 1.90 cm ho])ow (4.35 m ± 0.12) (p < 0.05). Mean ST was also significantly shorter when stopping on the 0.63 cm hollow then both the 1.27 cm and 1.90 cm hollows. Trial by trial results clearly illustrated the affect of fatigue on kinematic variables; AV, SR, IV decreased from trial 1 to 6. There was no significant effect on anaerobic performance variables during the RRS. Altering the skate blade ROH has a significant and practical affect on accelerating and stopping performance will be discussed in this paper.
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This study had three purposes related to the effective implem,entation and practice of computer-mediated online distance education (C-MODE) at the elementary level: (a) To identify a preliminary framework of criteria 'or guidelines for effective implementation and practice, (b) to identify areas ofC-MODE for which criteria or guidelines of effectiveness have not yet been developed, and (c) to develop an implementation and practice criteria questionnaire based on a review of the distance education literature, and to use the questionnaire in an exploratory survey of elementary C-MODE practitioners. Using the survey instrument, the beliefs and attitudes of 16 elementary C'- MODE practitioners about what constitutes effective implementation and practice principles were investigated. Respondents, who included both administrators and instructors, provided information about themselves and the program in which they worked. They rated 101 individual criteria statenlents on a 5 point Likert scale with a \. point range that included the values: 1 (Strongly Disagree), 2 (Disagree), 3 (Neutral or Undecided), 4 (Agree), 5 (Strongly Agree). Respondents also provided qualitative data by commenting on the individual statements, or suggesting other statements they considered important. Eighty-two different statements or guidelines related to the successful implementation and practice of computer-mediated online education at the elementary level were endorsed. Response to a small number of statements differed significantly by gender and years of experience. A new area for investigation, namely, the role ofparents, which has received little attention in the online distance education literature, emerged from the findings. The study also identified a number of other areas within an elementary context where additional research is necessary. These included: (a) differences in the factors that determine learning in a distance education setting and traditional settings, (b) elementary students' ability to function in an online setting, (c) the role and workload of instructors, (d) the importance of effective, timely communication with students and parents, and (e) the use of a variety of media.
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Introduction Man can be described as the being who shows himself in speech, and from birth to death is continually speaking. Communication is so close to us, so woven into our very being, that we have little understanding of the way it is constituted; for it is as hard to obtain distance from communication as it is to obtain distance from ourselves. All communication is not alike. There are two basic modesl of communication, the inauthentic and the authentic, between which there occurs a constant tension. It is in the inauthentic mode, points out Heidegger, that we find ourselves "proximately and for the most part"; 1. Being and Time, pg. 68 Dasein decides as to the way it will comport itself in taking up its task of having being as an issue for it. " •.• it~, in its very being 'choose' itself and win itself; it can also lose itself and never win itself or only "seem" to do so. But only in so far as it is essentially something which can be authentic--that is, something of its own--can it have lost itself and not yet won itself." 2. therefore Heidegger also terms it "everydayness".2 Caught up in the world of everydayness, our speaking covers over and conceals3 our rootedness in being, leaving us in the darkness of untruth. The image of darkness may be inferred from Heidegger's use of the image of "clearing,,4 to depict being as 2. ibid. pg. 69 "Dasein's average everydayness, however, is not to be taken as a mere 'aspect'. Here too, and even in the mode of inauthenticity, the structure of existentiality lies ~ priori and here too Dasein's being is an issue for it in a definite way; and Dasein comports itself towards it the mode of average everydayness, even if this is only the mode of fleeing in the face of it and forgetfulness thereof." 3. ibid. pg. 59 "covering over" and "concealing" are 1;yays Dasein tries to flee its task of having being as an issue for itself. " ••• This being can be covered up so extensively that it becomes forgotten and no question arises about it or its meaning ••• n How everyday speaking accomplishes this will be taken up in detail in the second chapter which explores Dasein's everyday speech. 4. ibid, pg. 171 lI ••• we have in mind nothing other than the Existential - ontological structure of this entity (Dasein), that it is in such a way as to be its 'there'. To say that it is -' illuminated' [tlerleuchtet"] means that as Being-in-theworld it is cleared [gelichtetJ in itself7 not through any other entity, but in such a way that it is itself the clearing. Only for an entity which is eXistentially cleared in this way does what is present-at-hand become accessible in the light or hidden in the dark •••• " 3 dis-coveredness and truth. Our first task will be to explore the nature of communication in general and then to explore each of the modes manifested in turn. The structure of the inauthentic mode of communication can be explored by asking the following questions: What is this speaking about? Who is it that is speaking and who is spoken to? Does this speaking show man in his speech? The authentic mode is distinguished by the rarity with which we encounter it; as the inauthentic conceals, so the authentic reveals our rootedness in being. Yet this rarity makes it difficult to delineate its elusive structure clearly. Its constituent elements can be brought into focus by asking the same questions of this mode that we previously asked of the inauthentic mode. Our initial response to the disclosure of the authentic mode is to attempt to abandon the inauthentic mode and leave the darkness behind dwelling only in the "lighted place". All through the ages, some men pushing this to extreme, have, upon uncovering their relatedness to being, experienced a deep longing to dwell in such a "place" of pure truth and oft times denigrated or attempted to exclude the everyday world. Such 4. flight is twice mistaken: first it atbempts to fix truth as unchanging and static and secondly, it opposes this to untruth which it seeks to abolish. This is both the wrong view of truth and the wrong view of untruth as Heidegger points out in The Origin of The-Work of Art: The Way-to-be of truth, i.e., of discoveredness, is under the sway of refusal. But this refusal is no lack or privation, as if truth could be simply discoveredness rid of all covers. If it could be that, it would no longer be itself . ••• Truth in its way-to-be is untruth.5 Pure light is not the nature of Being nor is pure unconcealedness possible for man. Failure to remember this is the failure to realize that communication destroys itself in such flight because it no longer maintains the contingency of its task, i.e., the dis-closedness of being. We are reminded of the strong attraction this flight from darkness held for Plato. Light, truth and Being are all beyond the darkness and have nothing to do with it. In Book VII of the R~public, Socrates' explanation of the Allegory of the Cave to Glaucon points to a decided preference men have for the "lighted place". 5. The Origin Of The Work Of Art, pg. 42 5. Come then, I said, and join me in this further thought, and do not be surprised that those who attained to this height are not willing to occupy themselves with the affairs of men, but their souls ever feel the upward urge and yearning for that sojourn above. For this, I take it, is likely if in this point too the likeliness of our image holds. 6 Despite the attraction to pure truth, human communication is more complex than putting down one mode of communication and picking up another. Due to the fact that we are always on the way, the title of my thesis will have to be amended: OUT OF THE DARKNESS AND INTO THE LIGHT--AGAIN AND AGAIN. It must be this way because this is what it means to be human. This is the point made by Mephisto to Faust in pointing out that man, standing between God and the devil, needs both darkness and light: Er findet sich in einem ewigen Gl~t Uns hat er in die Finsternis gebracht, Und euch taugt einzig Tag und Nacht. 7 6. Republic z (517 c & d) It should be noted however, that while the philosopherking must be compelled to return to the cave for purely political reasons, once he has taken adequate view of the "brightest region of being" he has the full truth and his return to darkness adds nothing to the truth. 7. Faust, pg. 188 6. This thesis proposes to examine the grounds that give rise to communication, uncovering the structure of its inauthentic and authentic modes and paying close attention to tpeir interrelationship and to their relationship to language as "the house of Being": language that both covers and opens up man's rootedness in Being, transforming him as he moves along his way, taking up his "ownmost task" of becoming who he is. roots. He is the being who shows himself inn that reflects his forgetfulness or remembrance of his rootedness in being. Man comes into an already existent world and is addressedl through things in the world which are c
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Functional Electrically Stimulated (FES) ami cycle ergometry is a relatively new technique for exercise in individuals with impairments of the upper limbs. The purpose of this study was to determine the effects of 12 weeks of FES arm cycle ergometry on upper limb function and cardiovascular fitness in individuals with tetraplegia. F!ve subjects (4M/1F; mean age 43.8 ± 15.4 years) with a spinal cord injury of the cervical spine (C3- C7; ASIA B-D) participated in 12 weeks of3 times per week FES arm cycle ergometry training. Exercise performance measures (time to fatigue, distance to fatigue, work rate) were taken at baseline, 6 weeks, and following 12 weeks of training. Cardiovascular measures (MAP, resting HR, average and peak HR during exercise, cardiovascular efficiency) and self reported upper limb function (as determined by the CUE, sf-QIF, SCI-SET questionnaires) were taken at baseline and following 12 weeks of training. Increases were found in time to fatigue (84.4%), distance to fatigue (111.7%), and work rate (51.3%). These changes were non-significant. There was a significant decrease in MAP (91.1 ± 13.9 vs. 87.7 ± 14.7 mmHg) following 12 weeks ofFES arm cycle ergometry. There was no significant change in resting HR or average and peak HR during exercise. Cardiovascular efficiency showed an increase following the 12 weeks ofFES training (142.9%), which was non-significant. There were no significant changes in the measures of upper limb function and spasticity. Overall, FES arm cycle ergometry is an effective method of cardiovascular exercise for individuals with tetraplegia, as evidenced by a significant decrease in MAP, however it is unclear whether 12 weeks of thrice weekly FES arm cycle ergometry may effectively improve upper limb function in all individuals with a cervical SCI.