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Sample records for water physiological characteristics

  1. Physiological characteristics of bacteria isolated from water brines within permafrost

    NASA Astrophysics Data System (ADS)

    Shcherbakova, V.; Rivkina, E.; Laurinavichuis, K.; Pecheritsina, S.; Gilichinsky, D.

    2004-01-01

    In the Arctic there are lenses of overcooled water brines (cryopegs) sandwiched within permafrost marine sediments 100 120 thousand years old. We have investigated the physiological properties of the pure cultures of anaerobic Clostridium sp. strain 14D1 and two strains of aerobic bacteria Psychrobacter sp. isolated from these cryopegs. The structural and physiological characteristics of new bacteria from water brines have shown their ability to survive and develop under harsh conditions, such as subzero temperatures and high salinity.

  2. [Effects of different irrigations on the water physiological characteristics of Haloxylon ammodendron in Taklimakan Desert hinterland].

    PubMed

    Xie, Ting-ting; Zhang, Xi-ming; Liang, Shao-min; Shan, Li-shan; Yang, Xiao-lin; Hua, Yong-hui

    2008-04-01

    By using heat-balance stem flow gauge and press chamber, the water physiological characteristics of Haloxylon ammodendron under different irrigations in Taklimakan Desert hinterland were measured and analyzed. The results indicated that the diurnal variation curve of H. ammodendron stem sap flow varied with irrigations. When irrigated 35 and 24.5 kg x plant(-1) once time, the diurnal variation of stem sap flow changed in single peak curve and the variation extent was higher; while irrigated 14 kg x plant(-1) once time, the diurnal variation changed in two-peak curve and the variation extent was small. With the decrease of irrigations, the average daily sap flow rate and the daily water consumption of H. ammodendron decreased gradually, the dawn and postmeridian water potential also had a gradual decrease, and the correlations of stem sap flow with total radiation, air temperature, relative humidity, and wind speed enhanced. Under different irrigations, the correlation between stem sap flow rate and total radiation was always the best. PMID:18593026

  3. [Effects of different K fertilizer and water level on growth and physiological characteristics of Isatis indigotica].

    PubMed

    Yang, Juan-Juan; Guo, Qiao-Sheng; Chen, Su-Dan; Deng, Qiao-Hua

    2014-05-01

    The experiment included three potassium levels (K0 0 g x kg(-1), K1 0.33 g x kg(-1), K2 0.67 g x kg(-1)) and two water gradients (well watered and drought stress), then measured growth indicators, SOD, POD, CAT activities and concents of osmotic regulation substances. To explore the effects of K fertilizer and water on growth and physiological characteristics of Isatis indigotica, providing reference for improving drought resistance of I. indigotica. The result showed drought stress inhibited the growth and decreased the biomass of I. indigotica but K fertilizer can alleviate the drought stress. Compared with K0 treatment, K1, K2 treatment increased the biomass of overground part of by 89. 13% ,60. 87% under drought stress. The corresponding increase in soluble sugar content was 16.67%, 5.00%, and in proline content was 42.41%, 65.62%, respectively. SOD,POD and CAT activities was significantly improved in K1, K2 treatment in comparison with K0 treatment under drought stress, but soluble protein content significantly reduced. The conclusion is that appropriate amount of K fertilizer can increase the activities of antioxidase and the content of osmoregulation substance under drought stress, and improve drought resistance of I. indigotica. PMID:25282880

  4. [Effects of simulated acid rain on water physiological characteristics of Myrica rubra seedlings].

    PubMed

    Yaho, Zhao-bin; Jiang, Hong; Yu, Shu-quan; Lu, Mei-juan

    2011-08-01

    Taking the seedlings of typical subtropical economic tree species Myrica rubra in Zhejiang Province as test materials, a pot experiment was conducted to study their water physiological characteristics under effects of simulated acid rain (pH 2.5 and pH 4.0), with water (pH 5.6) as the control. Season, year, and acid rain all had significant effects on the photosynthetic rate (Pn). Among the treatments, the Pn had a greater difference in summer than in spring and autumn, and was higher in treatment acid rain (pH 4.0). Season, year, acid rain, and the interactions of season and year and of the three factors had significant effects on the stomata conductance (Gs), and also, the Gs had a greater difference among the treatments in summer than in spring and autumn. Acid rain had inhibitory effect on Gs. Season, year, acid rain, and the interactions of season and year and of season and acid rain affected the transpiration rate (Tr) significantly. Same as Pn and Gs, the Tr had a greater difference among the treatments in summer than in spring and autumn. Acid rain (pH 2.5) had the strongest inhibitory effect on Tr. Acid rain and the interactions of season and year and of season and acid rain had significant effects on the water use efficiency (WUE), and acid rain (pH 2.5) had definitely positive effect on the WUE. PMID:22097355

  5. Physiological water model development

    NASA Technical Reports Server (NTRS)

    Doty, Susan

    1993-01-01

    The water of the human body can be categorized as existing in two main compartments: intracellular water and extracellular water. The intracellular water consists of all the water within the cells and constitutes over half of the total body water. Since red blood cells are surrounded by plasma, and all other cells are surrounded by interstitial fluid, the intracellular compartment has been subdivided to represent these two cell types. The extracellular water, which includes all of the fluid outside of the cells, can be further subdivided into compartments which represent the interstitial fluid, circulating blood plasma, lymph, and transcellular water. The interstitial fluid surrounds cells outside of the vascular system whereas plasma is contained within the blood vessels. Avascular tissues such as dense connective tissue and cartilage contain interstitial water which slowly equilibrates with tracers used to determine extracellular fluid volume. For this reason, additional compartments are sometimes used to represent these avascular tissues. The average size of each compartment, in terms of percent body weight, has been determined for adult males and females. These compartments and the forces which cause flow between them are presented. The kidneys, a main compartment, receive about 25 percent of the cardiac output and filters out a fluid similar to plasma. The composition of this filtered fluid changes as it flows through the kidney tubules since compounds are continually being secreted and reabsorbed. Through this mechanism, the kidneys eliminate wastes while conserving body water, electrolytes, and metabolites. Since sodium accounts for over 90 percent of the cations in the extracellular fluid, and the number of cations is balanced by the number of anions, considering the renal handling sodium and water only should sufficiently describe the relationship between the plasma compartment and kidneys. A kidney function model is presented which has been adapted from a previous model of normal renal function in man. To test the validity of the proposed kidney model, results predicted by the model will be compared to actual data involving injected or ingested fluids and subsequent urine flow rates. Comparison of the model simulation to actual data following the ingestion of 1 liter of water is shown. The model simulation is also shown with actual data following the intravenous infusion of hypertonic saline.

  6. Eco-physiological characteristics and variation in water source use between montane Douglas-Fir and lodgepole pine trees in southwestern Alberta

    NASA Astrophysics Data System (ADS)

    Andrews, S.; Flanagan, L. B.

    2009-12-01

    Winter weather on the Canadian prairies is now warmer and drier than 50 years ago and this has implications for soil water re-charge in montane ecosystems with consequences for tree and ecosystem function. We used measurements of the hydrogen isotope ratio of tree stem water to analyze the use of different water sources (winter snow melt, ground water, summer precipitation) in two montane forest sites, one dominated by Douglas-Fir and the other dominated by lodgepole pine trees. On average during the growing season (May-October) stem water in both Douglas-Fir and lodgepole pine trees was composed of 60% summer precipitation. However, during late summer Douglas-Fir trees showed an increased use of ground water as summer precipitation was minimal and ground water was accessible at the bottom of a relatively large soil reservoir. The low summer precipitation and reduced soil water availability in the shallow soils at the lodgepole pine site resulted in severely reduced photosynthetic capacity in late summer. Increased precipitation during the autumn resulted in recovery of photosynthetic gas exchange in lodgepole pine before winter dormancy was induced by low temperatures. Stomatal limitation of photosynthesis, as estimated from measurements of the carbon isotope composition of leaf tissue, was higher in Douglas-Fir than lodgepole pine. This was also associated with lower midday water potential values in Douglas-Fir and sapwood cross-sectional area that was only 70% of that measured in lodgepole pine. The vulnerability of xylem to loss of conductivity with declines in water potential was very similar between the two species. However, midday water potential in Douglas-Fir approached values where cavitation and loss of conductivity were apparent, while in lodgepole pine midday water potential was always much higher than the point at which loss of hydraulic conductivity occurred. These data suggest that, despite the presence of Douglas-Fir on deeper and higher quality soils, lodgepole pine appears to have eco-physiological characteristics that allow it to better withstand and recover from exposure to summer water deficits that may increase in association with trends to warmer and drier conditions.

  7. Impact of human emotions on physiological characteristics

    NASA Astrophysics Data System (ADS)

    Partila, P.; Voznak, M.; Peterek, T.; Penhaker, M.; Novak, V.; Tovarek, J.; Mehic, Miralem; Vojtech, L.

    2014-05-01

    Emotional states of humans and their impact on physiological and neurological characteristics are discussed in this paper. This problem is the goal of many teams who have dealt with this topic. Nowadays, it is necessary to increase the accuracy of methods for obtaining information about correlations between emotional state and physiological changes. To be able to record these changes, we focused on two majority emotional states. Studied subjects were psychologically stimulated to neutral - calm and then to the stress state. Electrocardiography, Electroencephalography and blood pressure represented neurological and physiological samples that were collected during patient's stimulated conditions. Speech activity was recording during the patient was reading selected text. Feature extraction was calculated by speech processing operations. Classifier based on Gaussian Mixture Model was trained and tested using Mel-Frequency Cepstral Coefficients extracted from the patient's speech. All measurements were performed in a chamber with electromagnetic compatibility. The article discusses a method for determining the influence of stress emotional state on the human and his physiological and neurological changes.

  8. Physiological characteristics of masters-level cyclists.

    PubMed

    Peiffer, Jeremiah J; Abbiss, Christopher R; Chapman, Dale; Laursen, Paul B; Parker, Daryl L

    2008-09-01

    Although a considerable amount of research is available describing the physiological characteristics of competitive young-adult cyclists, research describing these same characteristics in Masters-level cyclists is rare. Therefore, the purpose of this study was to describe and compare the effect of aging on physiological fitness parameters of Masters-level cyclists in an attempt to provide normative fitness data. Thirty-two male cyclists (35-73 years) completed one 15-minute economy test and one graded exercise test (GXT) on a cycle ergometer. During the GXT, maximal oxygen uptake ([latin capital V with dot above]o2max), maximal heart rate (HRmax), the first (VT1) and second (VT2) ventilatory thresholds, and peak power output (PPO) were recorded. For the purpose of analysis, subjects were allocated into three age groups (35-45 years, 45-54 years, >=55 years). Maximal oxygen uptake and absolute PPO were significantly lower among subjects 55 years and older (45.9 +/- 4.6 mL x kg(-1) x min(-1) and 324 +/- 51 W, respectively) compared with the 45- to 54-year group (54.2 +/- 6.6 mL x kg(-1) x min(-1) and 392 +/- 36 W, respectively), and both were significantly less compared with the 35- to 44-year group (60.7 +/- 5.1 mL x kg(-1) x min(-1) and 434 +/- 32 W, respectively). Maximal heart rate was significantly greater in both the 35- to 44-year and 45- to 54-year age groups compared with the >=55-year group. The first ventilatory threshold was significantly greater in the subjects who were 55 years and older group compared with the 35- to 44-year and 45- to 54-year age groups, and VT2 was significantly greater in subjects 55 years and older compared with the 35- to 44-year group. Economy was not different amongst groups. In conclusion, increases in age resulted in a significant reduction in fitness parameters across age groups. The comparison of the fitness characteristics of Masters-level cyclists with established young-adult cyclist data should be avoided, because this may lead to inaccurate assessments of fitness. PMID:18714246

  9. Physiological characteristics of badminton match play.

    PubMed

    Faude, Oliver; Meyer, Tim; Rosenberger, Friederike; Fries, Markus; Huber, Gnther; Kindermann, Wilfried

    2007-07-01

    The present study aimed at examining the physiological characteristics and metabolic demands of badminton single match play. Twelve internationally ranked badminton players (eight women and four men) performed an incremental treadmill test [VO(2peak = )50.3 +/- 4.1 ml min(-1) kg(-1) (women) and 61.8 +/- 5.9 ml min(-1) kg(-1) (men), respectively]. On a separate day, they played a simulated badminton match of two 15 min with simultaneous gas exchange (breath-by-breath) and heart rate measurements. Additionally, blood lactate concentrations were determined before, after 15 min and at the end of the match. Furthermore, the duration of rallies and rests in between, the score as well as the number of shots per rally were recorded. A total of 630 rallies was analysed. Mean rally and rest duration were 5.5 +/- 4.4 s and 11.4 +/- 6.0 s, respectively, with an average 5.1 +/- 3.9 shots played per rally. Mean oxygen uptake (VO(2)), heart rate (HR), and blood lactate concentrations during badminton matches were 39.6 +/- 5.7 ml min(-1) kg(-1) (73.3% VO(2peak)), 169 +/- 9 min(-1) (89.0% HR(peak)) and 1.9 +/- 0.7 mmol l(-1), respectively. For a single subject 95% confidence intervals for VO(2) and HR during match play were on average 45.7-100.9% VO(2peak) and 78.3-99.8% HR(peak). High average intensity of badminton match play and considerable variability of several physiological variables demonstrate the importance of anaerobic alactacid and aerobic energy production in competitive badminton. A well-developed aerobic endurance capacity seems necessary for fast recovery between rallies or intensive training workouts. PMID:17473928

  10. Physiologic Responses to Treadmill and Water Running.

    ERIC Educational Resources Information Center

    Bishop, Phillip A.; And Others

    1989-01-01

    Presents results of a study of the physiological responses of uninjured runners to running on a treadmill and in water. Water running may lessen an injured athlete's rate of deconditioning, but indications are that the metabolic cost of water running is not significantly greater than that of treadmill running. (SM)

  11. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY:

    EPA Science Inventory

    Twenty-one participants from Europe, North America and China convened in Chongqing, China, October 12-14, 2005, for the Eighth International Symposium in Fish Physiology, Toxicology and Water Quality. The subject of the meeting was "Hypoxia in vertebrates: Comparisons of terrestr...

  12. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY

    EPA Science Inventory

    Scientists from ten countries presented papers at the Fifth International Symposium on Fish Physiology, Toxicology, and Water Quality, which was held on the campus of the city University of Hong Kong on November 10-13, 1998. These Proceedings include 23 papers presented in sessi...

  13. Physiological characteristics of well-trained junior sprint kayak athletes.

    PubMed

    Borges, Thiago Oliveira; Dascombe, Ben; Bullock, Nicola; Coutts, Aaron J

    2015-07-01

    This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n=21, VO2max 4.1±0.7 L/min, training experience 2.7±1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscle-oxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (-.5 to -.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (-.4 to -.7) with 200- and 1000-m performance. In addition, trivial to large correlations (-.11 to -.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (P<.001), whereas 85% of the unadjusted variance in 1000-m TT performance was explained by VO2max and deoxyhemoglobin (P<.001). The current findings show that well-trained junior sprint kayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation. PMID:25473923

  14. The Clinical Physiology of Water Metabolism

    PubMed Central

    Weitzman, Richard E.; Kleeman, Charles R.

    1979-01-01

    Water balance is tightly regulated within a tolerance of less than 1 percent by a physiologic control system located in the hypothalamus. Body water homeostasis is achieved by balancing renal and nonrenal water losses with appropriate water intake. The major stimulus to thirst is increased osmolality of body fluids as perceived by osmoreceptors in the anteroventral hypothalamus. Hypovolemia also has an important effect on thirst which is mediated by arterial baroreceptors and by the renin-angiotensin system. Renal water loss is determined by the circulating level of the antidiuretic hormone, arginine vasopressin (AVP). AVP is synthesized in specialized neurosecretory cells located in the supraoptic and paraventricular nuclei in the hypothalamus and is transported in neurosecretory granules down elongated axons to the posterior pituitary. Depolarization of the neurosecretory neurons results in the exocytosis of the granules and the release of AVP and its carrier protein (neurophysin) into the circulation. AVP is secreted in response to a wide variety of stimuli. Change in body fluid osmolality is the most potent factor affecting AVP secretion, but hypovolemia, the renin-angiotensin system, hypoxia, hypercapnia, hyperthermia and pain also have important effects. Many drugs have been shown to stimulate the release of AVP as well. Small changes in plasma AVP concentration of from 0.5 to 4 μU per ml have major effects on urine osmolality and renal water handling. ImagesFigure 5.Figure 12.Figure 15.Figure 16. PMID:394480

  15. Anthropometric and physiological characteristics of rugby union football players.

    PubMed

    Nicholas, C W

    1997-06-01

    Rugby union enjoys worldwide popularity, but there is a lack of comprehensive research into the anthropometric and physiological characteristics of its players and the demands of the game, particularly at the elite level. One of the possible explanations for this is that the sport has previously been primarily concerned with the aspects of skill related to the game, rather than the physical and physiological requirements. However, with the increased physiological demands being placed on the elite players (using the British Isles as an example), with the recent introduction of professionalism, regional championships, the World Cup and major tours, information about the demands of the game and the assessment of, and methods of improving, the anthropometric and physiological characteristics of its players, are of paramount importance. Match analysis has indicated that rugby is an interval or intermittent sport and players must be able to perform a large number of intensive efforts of 5 to 15 seconds' duration with less than 40 seconds' recovery between each bout of high intensity activity. These observations, together with the metabolic responses during the game, give some insight into its physiological demands and are a prerequisite in the development and prescription of training programmes by coaches in preparing individual players for competition. The results from studies reporting the anthropometric and physiological characteristics of rugby union players observed that these individuals had unique anthropometric and physiological attributes which depended on positional role and the playing standard. These have important implications for team selection and highlight the necessity for individualised training programmes and fitness attainment targets. PMID:9219321

  16. Citation Characteristics of Physiology Literature, 1970-72

    ERIC Educational Resources Information Center

    Hafner, A. W.

    1976-01-01

    To identify and describe selected characteristics of the research literature of the basic medical science area of physiology during the three-year period 1970-72, this literature was analyzed to determine where, when, by what subject area, and in what countries it was published. (Author/PF)

  17. Physical and chemical characteristics of pitaya fruits at physiological maturity.

    PubMed

    Ortiz, T A; Takahashi, L S A

    2015-01-01

    The aim of this study was to analyze the physical and chemical characteristics of the maturation process of pitaya fruit (Hylocereus undatus) to identify indicators that can be used to determine the point of physiological maturity and establish the optimal timing of physiological maturity for harvesting the fruit. A completely randomized experimental design was employed and four biological repeats were performed. Physiological maturity was assessed using various physical characteristics: longitudinal length (LL), equatorial diameter (ED), pericarp thickness (PeT), pulp thickness (PuT), fruit mass (FM), pulp mass (PuM), pericarp mass (PeM), pericarp percentage (%Pe), pulp percentage (%Pu), pulp/pericarp ratio (Pu/Pe), pericarp color index (CI), hue color angle (h°), lightness index (L*), chroma (C*), blue-yellow variation (b*), and green-red variation (a*). Additionally, chemical characteristics such as soluble solid content (SS), titratable acidity (TA), SS/TA ratio, and pH were screened. The data were statistically analyzed by fitting regression models and computing Pearson's correlation coefficients (P < 0.05). Physiological maturity in pitaya fruits occurred between the 30th and 32nd days after anthesis, and this proved to be the optimal period for harvest. At this time, the fruit was completely red with high SS, and had the recommended values of TA, pH, and SS/TA ratio. During this period, ED, PuT, FM, PuM, %Pu, and Pu/Pe increased while PeT, PeM, and %Pe fell; these changes are considered desirable by producers and/or consumers. PuM was the variable that displayed more strong's association with other variables in the analysis. PMID:26600501

  18. Physiological and physical characteristics of elite dragon boat paddlers.

    PubMed

    Ho, Sarah R; Smith, Richard M; Chapman, Philip G; Sinclair, Peter J; Funato, Kazuo

    2013-01-01

    The objectives of this study were to profile the physiological and physical characteristics of elite dragon boat paddlers, to identify characteristics that predict race performance and to quantify the metabolic energy contributions to simulated 200-m and 500-m dragon boat racing. Eleven, national level, male, Japanese dragon boat paddlers completed a battery of tests on a paddling ergometer including an incremental maximal aerobic capacity test, a 2-minute maximal accumulated oxygen deficit (MAOD) test, and simulated 200-m and 500-m races. A physiological and physical profile of subjects was compiled. Results showed that 200-m race performance correlated with flexed arm girth and excess postexercise oxygen consumption (EPOC) measured in the 30 minutes after the MAOD test, whereas 500-m race performance correlated with body fat percentage, relaxed and flexed arm girth, MAOD, EPOC, and peak power during the MAOD test. Stepwise multiple regression revealed that flexed arm girth was the most powerful predictor of 200-m and 500-m race performance, followed by EPOC with the combination of these 2 factors able to explain 74% and 68% of the variance in 200-m and 500-m race performance, respectively. Aerobic energy contributions for 200-m (50 seconds) and 500-m (1 minute 50 seconds) races were (mean (95% confidence intervals)) 52.1% (range, 47.4-56.8%) and 67.5% (range, 60.1-77.8%), respectively. In conclusion, coaches should develop training programs targeted at developing upper-body musculature and increasing anaerobic capacity because these factors are the strongest predictors of 200-m and 500-m race performance. Given the substantial aerobic energy contributions even for a 200-m race event, coaches should aim to increase the maximal aerobic capacity of the paddler in preparation for both 200-m and 500-m events. PMID:23254488

  19. The physiology of deep-water running.

    PubMed

    Reilly, Thomas; Dowzer, Clare N; Cable, N T

    2003-12-01

    Deep-water running is performed in the deep end of a swimming pool, normally with the aid of a flotation vest. The method is used for purposes of preventing injury and promoting recovery from strenuous exercise and as a form of supplementary training for cardiovascular fitness. Both stroke volume and cardiac output increase during water immersion: an increase in blood volume largely offsets the cardiac decelerating reflex at rest. At submaximal exercise intensities, blood lactate responses to exercise during deep-water running are elevated in comparison to treadmill running at a given oxygen uptake (VO2). While VO2, minute ventilation and heart rate are decreased under maximal exercise conditions in the water, deep-water running nevertheless can be justified as providing an adequate stimulus for cardiovascular training. Responses to training programmes have confirmed the efficacy of deep-water running, although positive responses are most evident when measured in a water-based test. Aerobic performance is maintained with deep-water running for up to 6 weeks in trained endurance athletes; sedentary individuals benefit more than athletes in improving maximal oxygen uptake. There is some limited evidence of improvement in anaerobic measures and in upper body strength in individuals engaging in deep-water running. A reduction in spinal loading constitutes a role for deep-water running in the prevention of injury, while an alleviation of muscle soreness confirms its value in recovery training. Further research into the applications of deep-water running to exercise therapy and athletes' training is recommended. PMID:14748454

  20. Methanogenic archaea database containing physiological and biochemical characteristics.

    PubMed

    Jabłoński, Sławomir; Rodowicz, Paweł; Łukaszewicz, Marcin

    2015-04-01

    The methanogenic archaea are a group of micro-organisms that have developed a unique metabolic pathway for obtaining energy. There are 150 characterized species in this group; however, novel species continue to be discovered. Since methanogens are considered a crucial part of the carbon cycle in the anaerobic ecosystem, characterization of these micro-organisms is important for understanding anaerobic ecology. A methanogens database (MDB; http://metanogen.biotech.uni.wroc.pl/), including physiological and biochemical characteristics of methanogens, was constructed based on the descriptions of isolated type strains. Analysis of the data revealed that methanogens are able to grow from 0 to 122 °C. Methanogens growing at the same temperature may have very different growth rates. There is no clear correlation between the optimal growth temperature and the DNA G+C content. The following substrate preferences are observed in the database: 74.5% of archaea species utilize H2+CO2, 33% utilize methyl compounds and 8.5% utilize acetate. Utilization of methyl compounds (mainly micro-organisms belonging to the genera Methanosarcina and Methanolobus ) is seldom accompanied by an ability to utilize H2+CO2. Very often, data for described species are incomplete, especially substrate preferences. Additional research leading to completion of missing information and development of standards, especially for substrate utilization, would be very helpful. PMID:25604335

  1. The Clinical Physiology of Water Metabolism

    PubMed Central

    Weitzman, Richard E.; Kleeman, Charles R.

    1979-01-01

    The renal reabsorption of water independent of solute is the result of the coordinated function of the collecting duct and the ascending limb of the loop of Henle. The unique juxtaposition of the ascending and descending portions of the loop of Henle and of the vasa recta permits the function of a counter-current multiplier system in which water is removed from the tubular lumen and reabsorbed into the circulation. The driving force for reabsorption is the osmotic gradient in the renal medulla which is dependent, in part, on chloride (followed by sodium) pumping from the thick ascending loop of Henle. Urea trapping is also thought to play an important role in the generation of a hypertonic medullary interstitium. Arginine vasopressin (AVP) acts by binding to receptors on the cell membrane and activating adenylate cyclase. This, inturn, results in the intracellular accumulation of cyclic adenosine monophosphate (AMP) which in some fashion abruptly increases the water permeability of the luminal membrane of cells in the collecting duct. As a consequence, water flows along an osmotic gradient out of the tubular lumen into the medullary interstitium. Diabetes insipidus is the clinical condition associated with either a deficiency of or a resistance to AVP. Central diabetes insipidus is due to diminished release of AVP following damage to either the neurosecretory nuclei or the pituitary stalk. Possible causes include idiopathic, familial, trauma, tumor, infection or vascular lesions. Patients present with polyuria, usually beginning over a period of a few days. The diagnosis is made by showing that urinary concentration is impaired after water restriction but that there is a good response to exogenous vasopressin therapy. Nephrogenic diabetes insipidus can be identified by a patient's lack of response to AVP. Nephrogenic diabetes insipidus is caused by a familial defect, although milder forms can be acquired as a result of various forms of renal disease. Central diabetes insipidus is eminently responsive to replacement therapy, particularly with dDAVP, a long lasting analogue of AVP. Nephrogenic diabetes insipidus is best treated with a combination of thiazide diuretics as well as a diet low in sodium and protein. ImagesFigure 27.Figure 31. PMID:545867

  2. The Clinical Physiology of Water Metabolism

    PubMed Central

    Weitzman, Richard E.; Kleeman, Charles R.

    1980-01-01

    Hyperosmolality occurs when there are defects in the two major homeostatic mechanisms required for water balance—thirst and arginine vasopressin (AVP) release. In this situation hypotonic fluids are lost in substantial quantities causing depletion of both intracellular and extracellular fluid compartments. Patients with essential hypernatremia have defective osmotically stimulated AVP release and thirst but may have intact mechanisms for AVP release following hypovolemia. Hyperosmolality can also be seen in circumstances in which impermeable solutes are present in excessive quantities in extracellular fluid. Under these conditions there is cellular dehydration and the serum sodium may actually be reduced by water drawn out of cells along an osmotic gradient. Hyposmolality and hyponatremia may be seen in a variety of clinical conditions. Salt depletion, states in which edema occurs and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) may all produce severe dilution of body fluids resulting in serious neurologic disturbances. The differential diagnosis of these states is greatly facilitated by careful clinical assessment of extracellular fluid volume and by determination of urine sodium concentration. Treatment of the hyposmolar syndromes is contingent on the pathophysiology of the underlying disorder; hyponatremia due to salt depletion is treated with infusions of isotonic saline whereas mild hyponatremia in cirrhosis and ascites is best treated with water restriction. Severe symptomatic hyponatremia due to SIADH is treated with hypertonic saline therapy, sometimes in association with intravenous administration of furosemide. Less severe, chronic cases may be treated with dichlormethyltetracycline which blocks the action of AVP on the collecting duct. ImagesFigure 43.Figure 44.Figure 47. PMID:6246683

  3. Physiological characteristics of elite and sub-elite badminton players.

    PubMed

    Ooi, Cheong Hwa; Tan, Albert; Ahmad, Azwari; Kwong, Kien Weng; Sompong, Ruji; Ghazali, Khairul Aswadi Mohd; Liew, Swee Lee; Chai, Wen Jin; Thompson, Martin William

    2009-12-01

    The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance. PMID:19967588

  4. [Effect of red and blue spectrum on photosynthesis physiological characteristics of two ecotypes of Leymus chinensis].

    PubMed

    Zhou, Chan; Yang, Yun-Fei; Wang, Kun

    2008-07-01

    Photosynthesis physiological characteristics of two ecotypes of Leymus chinensis were studied under different red and blue light excitation by LED red and blue lamp-house. Photosynthesis did not carry on under red and blue light of 50 micromol x m(-2) x s(-1). When red and blue light intensity was increased, photosynthesis rate, stoma limit value and transpiration rate of the two ecotypes of Leymus chinensis were all increased. But photosynthesis rate stopped increasing under red and blue light of 1 150 micromol x m(-2) x s(-1) for grey-green ecotype Leymus chinensis and of 907 micromol x m(-2) x s(-1) for yellow-green ecotype Leymus chinensis, which is known as light saturation. And the effect of blue light on photosynthesis became weaker than red light under higher light intensity. Increasing light intensity can promote plant photosynthesis rate in the range of low light intensity. But when light intensity reaches light saturation, photosynthesis rate does not increases but decreases. Because though light quantum numbers is increasing, the numbers of coloring mater does not change and is saturated. On the other hand, when the light intensity is of light saturation, the stoma limit value was increased and the transpiration rate was decreased in order to reduce water waste. When light intensity reaches the value that plant can bear, the plant will automatically close stoma in order to decrease transpiration and to save water. Plant balances every physiological index and makes sure that physiology damage is the least and production is the greatest. Although grey-green ecotype Leymus chinensis has lower stoma limit and higher water waste, it also has higher photosynthesis rate than yellow-green ecotype Leymus chinensis. And the photosynthesis capability and physiology adaptation of grey-green ecotype Leymus chinensis is greater than that of yellow-green ecotype Leymus chinensis. PMID:18844135

  5. Physiological Effects of Trace Elements and Chemicals in Water

    ERIC Educational Resources Information Center

    Varma, M. M.; And Others

    1976-01-01

    The physiological effects on humans and animals of trace amounts of organic and unorganic pollutants in natural and waste waters are examined. The sensitivity of particular organs and species is emphasized. Substances reviewed include mercury, arsenic, cadmium, lead, chromium, fluorides, nitrates and organics, including polychlounated biphenyls.

  6. SYMPOSIUM IN ITALY: FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY

    EPA Science Inventory

    Scientists from Europe, North America and South America convened in Capri, Italy, April 24-28, 2006 for the Ninth International Symposium on Fish Physiology, Toxicology, and Water Quality. The subject of the meeting was Eutrophication: The toxic effects of ammonia, nitrite and th...

  7. Physiological Effects of Trace Elements and Chemicals in Water

    ERIC Educational Resources Information Center

    Varma, M. M.; And Others

    1976-01-01

    The physiological effects on humans and animals of trace amounts of organic and unorganic pollutants in natural and waste waters are examined. The sensitivity of particular organs and species is emphasized. Substances reviewed include mercury, arsenic, cadmium, lead, chromium, fluorides, nitrates and organics, including polychlounated biphenyls.…

  8. [Anatomic, physiological and metabolic characteristics of young athletes].

    PubMed

    Nikitiuk, D B; Korosteleva, M M; Volkova, L Iu

    2013-01-01

    A rational approach to the organization of the training process, the competitive cycle, the recovery processes in the practice of child and youth sport requires knowledge of the anatomical and physiological characteristics of the organism in these age periods. Exchange of amino acids in children of 6 to 12 years takes place very actively providing processes of growth and development. The children of preschool and early school age have tendency to hypoglycemia due to the imperfection of neurohumoral regulation of the mobilization of glycogen in the liver and increased utilization of glucose. Glucose utilization corresponds to its level in adults, ranging from 8 to 14 years of age. In children under the age of 10 an increased tendency to the formation of ketone bodies and ketosis is determined. Cholesterol levels increase rapidly after birth. From the period of puberty, girls have higher levels of total cholesterol, cholesterol in low density lipoprotein (LDL) and high density lipoproteins (HDL) than boys. At the age of 6-12 years basal metabolic rate decreases to 1.3-1.5 kcal/kg/h. The muscular system increasingly develops. Functional features of the central nervous system is the predominance of excitation. Sympathetic part of the autonomic nervous system prevails in heart's activity. The role of the hypothalamic-pituitary system significantly increases in the structure of the endocrine glands. The sensitivity of many endocrine glands to the tropic hormone produced in the adenohypophysis increases. At the age of 8-12 years the role of epinephrine, norepinephrine and other biogenic amines especially increases. Period of puberty at the age of 13-17 years is associated with a significant change in the hormonal status of the organism. A pubertal growth spurt takes place, which occurs 1-2 years earlier in girls than in boys. As for the skeletal system the most pronounced growth of tubular bones of the limbs, spine and increase of bone density, muscle mass occurs. Heart rate decreases, while the duration of the expulsion phase of blood, cardiac output, respiratory functional parameters and red blood cells and hemoglobin concentrations increase. Endurance rises, physical activity is more economical than in childhood. PMID:24741954

  9. Contrasting Physiological Responses of Six Eucalyptus Species to Water Deficit

    PubMed Central

    Merchant, Andrew; Callister, Andrew; Arndt, Stefan; Tausz, Michael; Adams, Mark

    2007-01-01

    Background and Aims The genus Eucalyptus occupies a broad ecological range, forming the dominant canopy in many Australian ecosystems. Many Eucalyptus species are renowned for tolerance to aridity, yet inter-specific variation in physiological traits, particularly water relations parameters, contributing to this tolerance is weakly characterized only in a limited taxonomic range. The study tests the hypothesis that differences in the distribution of Eucalyptus species is related to cellular water relations. Method Six eucalypt species originating from (1) contrasting environments for aridity and (2) diverse taxonomic groups were grown in pots and subjected to the effects of water deficit over a 10-week period. Water potential, relative water content and osmotic parameters were analysed by using pressure–volume curves and related to gas exchange, photosynthesis and biomass. Key Results The six eucalypt species differed in response to water deficit. Most significantly, species from high rainfall environments (E. obliqua, E. rubida) and the phreatophyte (E. camaldulensis) had lower osmotic potential under water deficit via accumulation of cellular osmotica (osmotic adjustment). In contrast, species from low rainfall environments (E. cladocalyx, E. polyanthemos and E. tricarpa) had lower osmotic potential through a combination of both constitutive solutes and osmotic adjustment, combined with reductions in leaf water content. Conclusions It is demonstrated that osmotic adjustment is a common response to water deficit in six eucalypt species. In addition, significant inter-specific variation in osmotic potential correlates with species distribution in environments where water is scarce. This provides a physiological explanation for aridity tolerance and emphasizes the need to identify osmolytes that accumulate under stress in the genus Eucalyptus. PMID:17905722

  10. Physiological characteristics of mercury uptake by two estuarine species

    USGS Publications Warehouse

    Luoma, S.N.

    1977-01-01

    Rapid uptake and slow loss of Hg will result from short exposures of some organisms to this metal, due to the transformation of Hg to a slowly exchanging form within the organisms. The extent of the difference between exposure time and depuration time will depend upon the rate of transformation during uptake. For the polychaete worm Neanthes succinea and the shrimp Palaemon debilis such transformations are extremely rapid. The exchange of Hg from the slowly exchanging compartment is similar among a wide variety of species. Thus, interspecies differences in susceptibility to Hg may be determined by differences in biochemical transformation rates and physiological permeability to the metal. ?? 1977 Springer-Verlag.

  11. Differential responses of grapevine rootstocks to water stress are associated with adjustments in fine root hydraulic physiology and suberization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water deficits are known to alter fine root structure and function, but little is known about how these responses contribute to differences in drought resistance across grapevine rootstocks. We studied how water deficit affects root anatomical and physiological characteristics in two grapevine root...

  12. Physiology

    ERIC Educational Resources Information Center

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  13. [Effect of drought stress on growth and physiological-biochemical characteristics of Stellaria dichotoma].

    PubMed

    Lang, Duo-Yong; Cui, Jia-Jia; Da, Zhou; Li, Yue-Tong; Zhou, Li; Zhang, Xin-Hui

    2014-06-01

    A pot experiment was conducted to study effect of drought stress on leaf physiological characteristics and growth of one year old Stellaria dichotoma seedlings. The result showed that plant height and shoot dry weight significantly decreased with decrease in soil water content; however, root length and root dry weight increased at light drought stress and decreased at severe drought stress. The result also showed that with the decrease of soil water content, proline content in S. dichotoma leaves decreased then increase, while solube protein content decreased. Activities of SOD and POD in S. dichotoma leaves significantly decreased as soil water content decreased, while activity of CAT significantly decreased at severe drought stress. Membrane permeability in S. dichotoma leaves increased, while MDA content decreased then increased as soil water decreased. These results suggest that S. dichotoma had osmotic stress resistance ability and reactive oxygen scavenging capacity at light drought stress, which caused S. dichotoma growth was no inhibited at a certain extent drought stress. PMID:25272829

  14. Physiological characteristics and performance of top U.S. biathletes.

    PubMed

    Rundell, K W; Bacharach, D W

    1995-09-01

    Success in biathlon involves skiing fast and shooting accurately. The purpose of this study was to determine whether physiological laboratory test results relate to success in biathlon. Tests included treadmill run and double-pole lactate profile and VO2peak tests, and a double-pole peak power test (UBP). 1993 National Points Rank (NR), racing ski time (ST), and shooting percentage (SP) from 1993 World Team Trials and laboratory test results (1993; N = 11 males, 10 females) were examined. Of athletes tested, six males and six females were top 10 U.S. ranked. Significance was identified between NR and ST (males, r = -0.88; females, r = -0.91). NR and SP were related for females (r = 0.75). Maximum run time during the VO2peak test was the only parameter related to NR (r = 0.72) or ST (r = -0.80) for males. Significance was identified for an uphill 1 km on snow double-pole time trial to NR (r = -0.84) and SP (r = -0.79) (subgroup; N = 8 males). For females, NR was related to running VO2peak (r = 0.81) and UBP (r = 0.95). Double-pole and running VO2peak were related to SP for women. This study suggests that SP is more important to NR for females than for males, and gender-specific tests might better predict success in elite biathlon skiers. PMID:8531629

  15. Physiological characteristics of elite dancers of different dance styles.

    PubMed

    Liiv, Helena; Jürimäe, Toivo; Mäestu, Jarek; Purge, Priit; Hannus, Aave; Jürimäe, Jaak

    2014-01-01

    The present investigation was aimed to study international level dancesport dancer's aerobic capacity during incremental test and competition simulation in relation to the gender, dance style and international ranking. A total of 30 couples (12 Standard, 7 Latin American and 11 Ten Dance; aged 22.8 ± 6.6 years male and 22.0 ± 6.4 years female) performed an incremental treadmill test and competition simulation. In this study for the first time we carried out longer than one round competition simulation and compared three different dancesport styles (Standard, Latin American and Ten Dance). The results showed that dancers of these three dance styles had similar aerobic capacity values. The average maximal oxygen consumption (VO2max) values were 59.6 ± 5.1 and 51.2 ± 6.2 ml · min(-1) · kg(-1) for male and female dancers, respectively. Competition simulation showed that Latin American Dance discipline is physiologically more intensive compared to Standard and Ten Dance styles especially for the female dancers. It appeared that male and female Standard dancers tended to perform at lower intensity than anaerobic threshold (AT) during competition simulation (male 97.3 ± 2.9%; female 97.9 ± 3.6%), while Latin (male 101.4 ± 2.9%; female 106.7 ± 5.9%) and Ten Dance (male 100.7 ± 6.4%; female 99.2 ± 5.6%) competition intensity was higher compared to AT level of athletes. The highest heart rate during competition simulation was always found during the last dances (Paso Double, Jive or Quickstep) and in the last round of each dance style. No significant relationship between VO2max values and international rankings was registered. PMID:24444238

  16. [Effects of irrigation amount at seedling stage on physiological characteristics and yield of peanut].

    PubMed

    Yan, Mei-ling; Jiao, Yan-lin; Li, Xiang-dong; Liu, Zhi-jian; Tang, Xiao; Lin, Ying-jie

    2007-02-01

    Taking two peanut varieties with different drought-resistance Luhua 11 and Nongda 818 as test crops, the effects of different irrigation amount at seedling stage on their physiological characteristics and yield were studied from 2003 to 2004. The results showed that with decreasing irrigation amount, the leaf photosynthesis rate of test varieties decreased, while malondialdeyde (MDA) content increased. Watering 60-80 mm ( suitable drought) enhanced the activities of superoxide dismutase (SOD) , peroxidase (POD) and catlase (CAT) , and increased the content of soluble protein. After re-watering by the end of treatments, the activities of SOD, POD and CAT and the contents of soluble protein and MDA decreased significantly, while photosynthesis rate increased obviously. The pod and kernel yield decreased with decreasing irrigation amount, and Luhua 11 had a greater loss than Nongda 818, indicating that Nongda 818 was more drought-tolerant than Luhua 11. It was suggested that under water-saving culture, the irrigation amount at seedling stage could not be less than 80 mm for Luhua 11, and less than 60 mm for Nongda 818. PMID:17450738

  17. Apparent water permeability as a physiological parameter in crustaceans

    PubMed

    Rasmussen; Andersen

    1996-01-01

    This article reviews the use of apparent water permeability (AWP) calculated from measurements of isotope-labelled water flux as a physiological estimate of whole-body water permeability in aquatic invertebrates. The rationale and practices of AWP calculations are described in an Appendix. AWP calculations have provided a wealth of information. However, the validity of the method and therefore also of the information obtained have been questioned. Consequently, the use of AWP data in discussions of osmotic and fluid homeostatic questions in aquatic invertebrates is limited. This article reviews three decades of published experiments in which measurements of isotope-labelled water fluxes were used to estimate water permeability in aquatic invertebrates. Data on 24 species of arthropod, most of them decapod crustaceans, are presented. The combined data indicate that the results obtained by different investigators on the same species show good agreement, even though different tracers and experimental methods have been applied. When available, results from other kinds of studies were used to evaluate the results obtained using the AWP measurements. The various results demonstrate that AWP is influenced not only by natural environmental factors, such as salinity and temperature, and by anthropogenic factors, such as potentially toxic trace metals, but that it is also regulated by intrinsic factors, such as ecdysis and life cycle stage. The results obtained can often be explained as effects of components of the habitat of the animal. Accordingly, studies on variations in AWP contribute to our understanding of the different physiological strategies used by species living in a changing environment. We conclude that calculations of AWP offer reliable, relevant physiological data in a range of crustacean species, as long as methodological limitations and uncertainties are kept in mind. In addition, we propose some possible new ways of applying AWP calculations to marine invertebrates other than crustaceans. A major part of this review describes results already obtained for the shore crab Carcinus maenas as this species is probably the animal on which most work has been carried out. We suggest topics for future work on this species and review the possibility of using AWP in C. maenas as a biomarker of metal exposure. PMID:9320480

  18. Dosimetry of [0-15] water: A physiologic approach

    SciTech Connect

    Narayana, S.; Boles, L.L.; Ponto, J.A.

    1994-05-01

    [O-15] water is a popular now based radiotracer (half life 2.03 m) used in measuring rCBF by PET. Previous dosimetry estimates assumed that [O-15] water instantaneously reached equilibrium with total body water. However, the biodistribution of this short-lived radiopharmaceutical is dependent upon blood flow to various organs. This assumption of instantaneous equilibrium leads to an underestimation of radiation dose to organs with high blood flows. More realistic dosimetry estimates were obtained by using a compartmental model approach. We have developed a whole body physiologically-based blood flow model using an icon driven mathematical simulation software package, STELLA (High Performance Systems, NH). The model uses multiple parallel compartments to represent various organs as well as heart chambers, injection site, and blood sampling sites. Input values to the model include organ blood flows, organ volumes, blood:tissue partition coefficients, injected activity and {triangle} and {phi} of O-15 (MIRD tables). The model is based on the same assumptions that are used in calculating rCBF using [O-15] water and simulates the human body closely in its physiologic response. The activity in each organ derived from the simulation is used to calculate the dose. Organs receiving high doses were gonads, heart, thyroid, kidneys and brain. The values obtained were approximately 2-3 fold higher than the estimates of Kearfott and consistent with the findings of Herscovitch. We believe this approach to be an easy and accurate dosimetry tool. The use of STELLA is applicable to any nuclide or tracer with appropriately designed models.

  19. Seasonal variations and aeration effects on water quality improvements and physiological responses of Nymphaea tetragona Georgi.

    PubMed

    Lu, Xiao-Ming; Lu, Peng-Zhen; Huang, Min-Sheng; Dai, Ling-Peng

    2013-01-01

    Seasonal variations and aeration effects on water quality improvements and the physiological responses of Nymphaea tetragona Georgi were investigated with mesocosm experiments. Plants were hydroponically cultivated in six purifying tanks (aerated, non-aerated) and the characteristics of the plants were measured. Water quality improvements in purifying tanks were evaluated by comparing to the control tanks. The results showed that continuous aeration affected the plant morphology and physiology. The lengths of the roots, petioles and leaf limbs in aeration conditions were shorter than in non-aeration conditions. Chlorophyll and soluble protein contents of the leaf limbs in aerated tanks decreased, while peroxidase and catalase activities of roots tissues increased. In spring and summer, effects of aeration on the plants were less than in autumn. Total nitrogen (TN) and ammonia nitrogen (NH4(+)-N) in aerated tanks were lower than in non-aerated tanks, while total phosphorus (TP) and dissolved phosphorus (DP) increased in spring and summer. In autumn, effects of aeration on the plants became more significant. TN, NH4(+)-N, TP and DP became higher in aerated tanks than in non-aerated tanks in autumn. This work provided evidences for regulating aeration techniques based on seasonal variations of the plant physiology in restoring polluted stagnant water. PMID:23819294

  20. Effects of potassium nutrition on physiological processes and derivative spectrum characteristics of corn plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the effects of potassium nutrition on growth, development and various other physiological processes and the spectrum characteristics of corn. Corn seeds were shown in sand culture using 3.8L pots in SPAR chambers with day/night temperatures of 30/220C and Carbon Di...

  1. [Effects of cadmium stress on the growth and physiological characteristics of Lonicera japonica].

    PubMed

    Liu, Zhou-li; He, Xing-yuan; Chen, Wei

    2009-01-01

    By using hydroponics, the growth and physiological characteristics of Lonicera japonica at different concentrations (0, 5, 10, 25, and 50 mg x L(-1)) of cadmium (Cd) were studied. The results showed that compared with the control, Cd stress had lesser effects on the growth of L. japonica. Within the range of test Cd concentrations, L. japonica biomass had less difference (P > 0.05) with the control, and at low concentration of Cd (5 mg x L(-1)), the total biomass and the biomasses of leaf and root were increased by 1.25%, 2.88 and 2.33%, respectively, illustrating that L. japonica had stronger resistance against Cd. Under low concentration Cd stress, the water content and soluble protein content in plant organs had some decrease, while the malondialdehyde (MDA) content in root and leaf increased by 51.90% and 23.07%, respectively, leaf chlorophyll and carotenoid contents increased by 15.87% and 24.89%, respectively, and superoxide dismutase (SOD) activity increased significantly. With increasing Cd concentration, the chlorophyll and carotenoid contents and SOD activity decreased to some extent. PMID:19449563

  2. Biological and physiological characteristics of Neotyphodium gansuense symbiotic with Achnatherum inebrians.

    PubMed

    Li, Chunjie; Nan, Zhibiao; Li, Fei

    2008-01-01

    Biological and physiological characteristics of Neotyphodium gansuense were compared with Neotyphodium coenophialum and Epichloë festucae at a range of temperatures and pH values, and on carbon and nitrogen amended media. N. gansuense was able to grow at 10-30 degrees C, but not at 5 degrees C, and slowly at 35 degrees C. The optimal temperature for both N. gansuense and N. coenophialum was 25 degrees C, but that of E. festucae was 20-25 degrees C. The optimal pH ranges for mycelial growth of N. gansuense, N. coenophialum and E. festucae were 5-9, 5-9 and 5-7, respectively. The Neotyphodium and Epichloë endophytes varied in their ability to grow on media containing different carbon and nitrogen nutrients. The preference of N. gansuense for carbon source was sucrose>glucose, lactose, sorbitol, inulin, maltose, mannitol, starch, fructose>xylose. Growth of all three endophytes tested was significantly improved by peptone, tryptone, casein, yeast extract and l-proline. Yeast extract, peptone, casein, tryptone, l-proline, potassium nitrate, ammonium oxalic acid and l-leucine significantly improved growth of N. gansuense. However, ammonium nitrite was not utilized at all by any tested endophyte. N. gansuense grew significantly better on potato dextrose agar (PDA) and oat meal agar (OMA) than on corn meal agar (CMA) and drunken-horse-grass agar (DA), and most slowly on water agar (WA) and saltwater nutrient agar (SNA). PMID:16962754

  3. Physiological state influences evaporative water loss and microclimate preference in the snake Vipera aspis.

    PubMed

    Dupoué, Andréaz; Stahlschmidt, Zachary R; Michaud, Bruno; Lourdais, Olivier

    2015-05-15

    Animals typically respond to environmental variation by adjusting their physiology, behavior, or both. Ectothermic animals are particularly sensitive to microclimatic conditions and behaviorally thermoregulate to optimize physiological performance. Yet, thermoregulation can be costly and may obligate a physiological tradeoff with water loss. Presumably, this tradeoff intensifies when animals undergo necessary life-history events (e.g., pregnancy or digestion) that impose significant behavioral and physiological changes, including shifts in behavioral thermoregulation and increased metabolic rate. Thus, behavioral responses, such as modified microclimatic preferences, may help mitigate the physiological tradeoff between thermoregulation and water loss. Herein, we examined the influence of major physiological states (specifically, pregnancy, ecdysis, and digestion) on evaporative water loss and on behavioral adjustments in a viviparous snake, Vipera aspis. First, we used open-flow respirometry to measure the effects of physiological states and microclimatic conditions (temperature and humidity) on the rate of total evaporative water loss (TEWL) and metabolic rate (rate of O2 consumption, V˙O2). Then, we experimentally tested the influence of physiological state on microclimate selection. We found that energy-demanding physiological states were associated with i) an increased rate of TEWL and V˙O2 compared to control states and ii) a slight preference (statistically marginal) for both warm and humid conditions compared to controls, suggesting a state-specificity in behavioral response. Overall our results underline the impact of physiological state on water loss and demonstrate the potential for behavior to mitigate the physiological tradeoff between thermoregulation and water balance. PMID:25725119

  4. Physiological evidence that pyramidal neurons lack functional water channels.

    PubMed

    Andrew, R David; Labron, Mark W; Boehnke, Susan E; Carnduff, Lisa; Kirov, Sergei A

    2007-04-01

    The physiological conditions that swell mammalian neurons are clinically important but contentious. Distinguishing the neuronal component of brain swelling requires viewing intact neuronal cell bodies, dendrites, and axons and measuring their changing volume in real time. Cultured or dissociated neuronal somata swell within minutes under acutely overhydrated conditions and shrink when strongly dehydrated. But paradoxically, most central nervous system (CNS) neurons do not express aquaporins, the membrane channels that conduct osmotically driven water. Using 2-photon laser scanning microscopy (2PLSM), we monitored neuronal volume under osmotic stress in real time. Specifically, the volume of pyramidal neurons in cerebral cortex and axon terminals comprising cerebellar mossy fibers was measured deep within live brain slices. The expected swelling or shrinking of the gray matter was confirmed by recording altered light transmittance and by indirectly measuring extracellular resistance over a wide osmotic range of -80 to +80 milliOsmoles (mOsm). Neurons expressing green fluorescent protein were then imaged with 2PLSM between -40 and +80 mOsm over 20 min. Surprisingly, pyramidal somata, dendrites, and spines steadfastly maintained their volume, as did the cerebellar axon terminals. This precluded a need for the neurons to acutely regulate volume, preserved their intrinsic electrophysiological stability, and confirmed that these CNS nerve cells lack functional aquaporins. Thus, whereas water easily permeates the aquaporin-rich endothelia and glia driving osmotic brain swelling, neurons tenatiously maintain their volume. However, these same neurons then swell dramatically upon oxygen/glucose deprivation or [K+]0 elevation, so prolonged depolarization (as during stroke or seizure) apparently swells neurons by opening nonaquaporin channels to water. PMID:16723408

  5. Influence of Morphological Characteristics on Physical and Physiological Performances of Tunisian Elite Male Handball Players

    PubMed Central

    Moncef, Cherif; Said, Mohamed; Olfa, Najlaoui; Dagbaji, Gomri

    2012-01-01

    Purpose The purpose of this study was to describe the body structure and morphological characteristics of Tunisian elite handball players, and to determine the effect of these variables on functional and physical performance levels. Methods A sample of 42 male handball players (mean age 21.98±3.24 years; training duration 12 years) at international level was submitted to a test battery comprising morphological, physical and physiological assessments. Tests were yo-yo intermittent recovery test, squat jump test, countermovement jump test, vertical-jump test, and Repeated sprint Ability. Measures for assessment of anthropometric characteristics were age, size, weight, body mass index, body fat, fat mass and thin mass. Results Weight was negatively correlated to the squat jump and the countermovement jump performance. Age, weight, and body composition measures (fat and thin body mass) were additionally negatively related to the maximal oxygen uptake, and to the maximal velocity obtained in the Yo-Yo recovery test. No relationship was found between size, body mass index, body fat and the physical abilities considered. Concerning the effects of physical characteristics on the functional performances, we can note a positive relationship between squat jump, countermovement jump, and the yo-yo recovery test performance. No relationship was found between vertical jump, repeated sprint ability, and the physiological performances. Conclusions Study results point to the existence of strong correlation between morphological and physical characteristics with functional characteristics. In handball, it is possible to have a reliable estimate of anthropometric measurements, physical and physiological performances. PMID:22942992

  6. Meta-analysis of digital game and study characteristics eliciting physiological stress responses.

    PubMed

    van der Vijgh, Benny; Beun, Robbert-Jan; Van Rood, Maarten; Werkhoven, Peter

    2015-08-01

    Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta-analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors. PMID:25950613

  7. Water stress and recovery in the performance of two Eucalyptus globulus clones: physiological and biochemical profiles.

    PubMed

    Correia, Barbara; Pintó-Marijuan, Marta; Neves, Lucinda; Brossa, Ricard; Dias, Maria Celeste; Costa, Armando; Castro, Bruno B; Araújo, Clara; Santos, Conceição; Chaves, Maria Manuela; Pinto, Glória

    2014-04-01

    Eucalyptus plantations are among the most productive forest stands in Portugal and Spain, being mostly used for pulp production and, more recently, as an energy crop. However, the region's Mediterranean climate, with characteristic severe summer drought, negatively affects eucalypt growth and increases mortality. Although the physiological response to water shortage is well characterized for this species, evidence about the plants' recovery ability remains scarce. In order to assess the physiological and biochemical response of Eucalyptus globulus during the recovery phase, two genotypes (AL-18 and AL-10) were submitted to a 3-week water stress period at two different intensities (18 and 25% of field capacity), followed by 1 week of rewatering. Recovery was assessed 1 day and 1 week after rehydration. Drought reduced height, biomass, water potential, NPQ and gas exchange in both genotypes. Contrarily, the levels of pigments, chlorophyll fluorescence parameters (F(v) /F(m) and (φPSII)), MDA and ABA increased. During recovery, the physiological and biochemical profile of stressed plants showed a similar trend: they experienced reversion of altered traits (MDA, ABA, E, g(s), pigments), while other parameters did not recover ((φPSII), NPQ). Furthermore, an overcompensation of CO(2) assimilation was achieved 1 week after rehydration, which was accompanied by greater growth and re-establishment of oxidative balance. Both genotypes were tolerant to the tested conditions, although clonal differences were found. AL-10 was more productive and showed a more rapid and dynamic response to rehydration (namely in carotenoid content, (φPSII) and NPQ) compared to clone AL-18. PMID:24117924

  8. Linkage of within vineyard soil properties, grapevine physiology, grape composition and sensory characteristics in a premium wine grape vineyard.

    NASA Astrophysics Data System (ADS)

    Smart, David; Hess, Sallie; Ebeler, Susan; Heymann, Hildegarde; Plant, Richard

    2014-05-01

    Analysis of numerous vineyards has revealed a very high degree of variation exists at the within vineyard scale and may outweigh in some cases broader mesoclimatic and geological factors. For this reason, selective harvest of high quality wine grapes is often conducted and based on subjective field sensory analysis (taste). This is an established practice in many wine growing regions. But the relationships between these subjective judgments to principle soil and grapevine physiological characteristics are not well understood. To move toward greater understanding of the physiological factors related to field sensory evaluation, physiological data was collected over the 2007 and 2008 growing seasons in a selectively harvested premium production Napa Valley estate vineyard, with a history of selective harvesting based on field sensory evaluation. Data vines were established and remained as individual study units throughout the data gathering and analysis phase, and geographic information systems science (GIS) was used to geographically scale physiological and other data at the vineyard level. Areas yielding grapes with perceived higher quality (subjective analysis) were characterized by vines with 1) statistically significantly lower (P < 0.05) leaf water potential (LWP) both pre-dawn (PD) and midday (MD), 2) smaller berry diameter and weight, 3) lower pruning weights, and 4) higher soluble solids (Brix). Strong positive correlations emerged between June ψPD and pre-harvest grape berry diameter (R2 = 0.616 in 2007 and 0.413 in 2008) and similar strong correlations existed for berry weight (R2 = 0.626 in 2007 and 0.554 in 2008). A trained sensory panel performed a sensory analysis and characterized fruit using and a multivariate, principal components, analysis (PCA). This approach indicated that grapes from vines with lowest midday leaf water potential at veraison (< -1.5 MPa) had sweeter and softer pulp, absence of vegetal characteristics, and browner and crunchier seeds, while grapes from vines of > -1.5 MPa were characterized by vegetal flavors and astringent and bitter seeds and skins. Data from vines were grouped into vines experiencing MD at veraison of < -1.5 MPa versus vines with MD > -1.5 MPa and subjected to single factor analysis of variance. This analysis revealed statistically significant differences (P less than 0.05) in many of the above properties - berry diameter, weight, pulp, and fruity versus vegetal characteristic. The groupings corresponded to the areas described as producing higher and lower quality fruit, respectively, based on field taste evaluation. Metabolomic analysis of grape skins from these two groups showed statistically significant differences in accumulation of amino acids and organic acids. Our results suggest there is not a continuous relationship between physiological water status (stress) and grape sensory characteristics, but rather the presence of an inflection point that may be related to early season PD in controlling grape development as well as composition. Soils analyses revealed the preferred fruit was on vines in areas where soils were shallower rather than any definitive characteristic related to particle size distribution or nutrient availability, suggesting that in this vineyard soil available water is the major controlling factor.

  9. Morphological and physiological characteristics of transgenic cherry tomato mutant with HBsAg gene.

    PubMed

    Guan, Z J; Guo, B; Huo, Y L; Hao, H Y; Wei, Y H

    2011-08-01

    HBsAg gene was previously introduced into cherry tomato (Lycopersicum esculentum var. cerasiforme) by Agrobacterium-mediated transformation. To investigate the side effect of HBsAg gene in cherry tomato, we analyzed morphological and physiological characteristics of the transgenic mutant N244. The process was performed under field conditions. The results suggested that the mutant N244 exhibited morphological, cytological and physiological variation. First of all, compared with the wild plants NK, N244 had fleshy and dark green leaves, the fewer notches of leaf edge, more adventitious roots and barren seeds. Moreover, the chromosome of N244 were found to be triploid (n = 36) by flow cytometric analysis. Furthermore, N244 has obvious physiological alterations, as compared to NK. It was speculated that transformation of the genes probably led to ploidy variation, and further caused phenotype and physiological changes of plants. Our study will reveal side effects of the mutants, and promote cultivation of transgenic plants in the field. PMID:21954613

  10. Comparison of the physiological characteristics of transgenic insect-resistant cotton and conventional lines

    PubMed Central

    Li, Xiaogang; Ding, Changfeng; Wang, Xingxiang; Liu, Biao

    2015-01-01

    The introduction of transgenic insect-resistant cotton into agricultural ecosystems has raised concerns regarding its ecological effects. Many studies have been conducted to compare the differences in characteristics between transgenic cotton and conventional counterparts. However, few studies have focused on the different responses of transgenic cotton to stress conditions, especially to the challenges of pathogens. The aim of this work is to determine the extent of variation in physiological characteristics between transgenic insect-resistant cotton and the conventional counterpart infected by cotton soil-borne pathogens. The results showed that the difference in genetic backgrounds is the main factor responsible for the effects on biochemical characteristics of transgenic cotton when incubating with cotton Fusarium oxysporum. However, genetic modification had a significantly greater influence on the stomatal structure of transgenic cotton than the effects of cotton genotypes. Our results highlight that the differences in genetic background and/or genetic modifications may introduce variations in physiological characteristics and should be considered to explore the potential unexpected ecological effects of transgenic cotton. PMID:25737015

  11. Is fishing selective for physiological and energetic characteristics in migratory adult sockeye salmon?

    PubMed

    Cooke, Steven J; Donaldson, Michael R; Hinch, Scott G; Crossin, Glenn T; Patterson, David A; Hanson, Kyle C; English, Karl K; Shrimpton, J Mark; Farrell, Anthony P

    2009-08-01

    There is extensive evidence that fishing is often selective for specific phenotypic characteristics, and that selective harvest can thus result in genotypic change. To date, however, there are no studies that evaluate whether fishing is selective for certain physiological or energetic characteristics that may influence fish behaviour and thus vulnerability to capture. Here, adult sockeye salmon (Oncorhynchus nerka) were used as a model to test the null hypothesis that fishing is not selective for specific physiological or energetic traits. Fish were intercepted during their spawning migrations, implanted with a gastric radio transmitter, and biopsied (i.e., non-lethally sampled for blood, gill tissue and quantification of energetic status). In both 2003 and 2006, we tagged and biopsied 301 and 770 sockeye salmon, respectively, in the marine environment en route to their natal river system to spawn. In 2006 an additional 378 individuals were tagged and biopsied in freshwater. We found that 23 (7.6%) of the marine fish tagged in 2003, 78 (10.1%) of the marine fish tagged in 2006 and 57 (15.1%) of the freshwater fish tagged in 2006 were harvested by one of three fisheries sectors that operate in the coastal marine environment and the Fraser River (i.e. commercial, recreational or First Nations fisheries between the site of release and Hell's Gate in the Fraser River, approximately 250 km upriver and 465 km from the ocean tagging site). However, fisheries were not open continually or consistently in different locations and for different fisheries sectors necessitating a paired analytical approach. As such, for statistical analyses we paired individual fish that were harvested with another fish of the same genetic stock that was released on the same date and exhibited similar migration behaviour, except that they successfully evaded capture and reached natal spawning grounds. Using two-tailed Wilcoxon matched pairs signed-rank tests, we revealed that the physiological and energetic characteristics of harvested fish did not differ from those of the successful migrants despite evaluating a number of biochemical (e.g. plasma metabolites, cortisol, plasma ions, gill Na(+)/K(+)-ATPase) and energetic (e.g. gross somatic energy density) variables (P's all >0.10). However, for some analyses we suffered low statistical power and the study design had several shortcomings that could have made detection of differences difficult. We suggest that additional research explore the concept of fishing-induced selection for physiological characteristics because physiology is closely linked to three traits where fisheries-induced selection does occur (i.e. life-history, behaviour and morphology). PMID:25567882

  12. Physiological, biochemical and molecular characteristics of cryopreserved Hypericum perforatum L. shoot tips.

    PubMed

    Skyba, Matús; Urbanová, Martina; Kapchina-Toteva, Veneta; Kosuth, Ján; Harding, Keith; Cellárová, Eva

    2010-01-01

    Hypericum perforatum L. in vitro cultured shoot tips were characterised at the physiological, biochemical and molecular levels following recovery from cryogenic treatment using the plant vitrification solutions PVS2 and PVS3. This comparative study revealed an increase in recovery and regrowth of explants cryoprotected with PVS3. Among the physiological markers only lipid peroxidation in the regenerants treated with PVS2 significantly increased indicating membrane damage. Genotype-specific interactions were found in most characteristics studied, with some variation detected within control and cryopreserved samples. Analyses of metabolite biosynthesis and genetic stability showed no significant differences in hypericin content, RAPD and minisatellite amplification profiles between PVS2- and PVS3-treated explants. This study demonstrates and discusses the criteria selective for PVS3 to improve the cryopreservation of H. perforatum L. PMID:20919454

  13. Ubiquity, diversity and physiological characteristics of Geodermatophilaceae in Shapotou National Desert Ecological Reserve

    PubMed Central

    Sun, Hong-Min; Zhang, Tao; Yu, Li-Yan; Sen, Keya; Zhang, Yu-Qin

    2015-01-01

    The goal of this study was to gain insight into the diversity of culturable actinobacteria in desert soil crusts and to determine the physiological characteristics of the predominant actinobacterial group in these crusts. Culture-dependent method was employed to obtain actinobacterial strains from desert soil samples collected from Shapotou National Desert Ecological Reserve (NDER) located in Tengger Desert, China. A total of 376 actinobacterial strains were isolated and 16S rRNA gene sequences analysis indicated that these isolates belonged to 29 genera within 18 families, among which the members of the family Geodermatophilaceae were predominant. The combination of 16S rRNA gene information and the phenotypic data allowed these newly-isolated Geodermatophilaceae members to be classified into 33 “species clusters,” 11 of which represented hitherto unrecognized species. Fermentation broths from 19.7% of the isolated strains showed activity in at least one of the six screens for antibiotic activity. These isolates exhibited bio-diversity in enzymatic characteristics and carbon utilization profiles. The physiological characteristics of the isolates from different types of crusts or bare sand samples were specific to their respective micro-ecological environments. Our study revealed that members of the family Geodermatophilaceae were ubiquitous, abundant, and diverse in Shapotou NDER, and these strains may represent a new major group of potential functional actinobacteria in desert soil. PMID:26483778

  14. Landscape and plant physiological controls on water dynamics and forest productivity within a watershed

    NASA Astrophysics Data System (ADS)

    Hu, Jia; Jencso, Kelsey; Looker, Nathaniel; Martin, Justin; Hoylman, Zachary

    2015-04-01

    Across the Western U.S., declining snowpacks have resulted in increased water limitation, leading to reduced productivity in high elevation forests. While our current understanding of how forests respond to climate change is typically focused on measuring/modeling the physiological responses and climate feedbacks, our study aims to combine physiology with hydrology to examine how landscape topography modulates the sensitivity of forests to climate. In a forested watershed in Western Montana, we linked climate variability to the physical watershed characteristics and the physiological response of vegetation to examine forest transpiration and productivity rates. Across the entire watershed, we found a strong relationship between productivity and the topographic wetness index, a proxy for soil moisture storage. However, this relationship was highly dependent on the intensity of solar radiation, suggesting that at high elevations productivity was limited by temperature, while at low elevations productivity was limited by moisture. In order to identify the mechanisms responsible for this relationship, we then examined how different coniferous species respond to changing environmental and hydrologic regimes. We first examined transpiration and productivity rates at the hillslope scale at four plots, ranging in elevation and aspect across the watershed. We found trees growing in the hollows had higher transpiration and productivity rates than trees growing in the side slope, but that these differences were more pronounced at lower elevations. We then used oxygen isotope to examine water source use by different species across the watershed. We found that trees growing in the hollows used snowmelt for a longer period. This was most likely due to upslope subsidies of snowmelt water to the hollow areas. However, we found that trees growing at lower elevations used proportionally more snowmelt than trees at the higher elevations. This was most likely due to the trees at lower elevation depending on deeper, more reliable water when the upper soils dried down during midsummer. These observations suggest that landscape topography influences the availability of soil water, which influences tree transpiration and productivity rates, thereby leading to watershed patterns of productivity.

  15. Landscape and plant physiological controls on water dynamics within a watershed

    NASA Astrophysics Data System (ADS)

    Hu, J.; Looker, N. T.; Martin, J. T.; Hoylman, Z. H.; Jencso, K. G.

    2014-12-01

    Across the Western U.S., declining snowpacks have resulted in increased water limitation, leading to reduced productivity in high elevation forests. While our current understanding of how forests respond to climate change is typically focused on measuring/modeling the physiological responses and climate feedbacks, our study aims to combine physiology with hydrology to examine how landscape topography modulates the sensitivity of forests to climate. In a forested watershed in Western Montana, we linked climate variability to the physical watershed characteristics and the physiological response of vegetation to examine forest transpiration and productivity rates. Across the entire watershed, we found a strong relationship between productivity and the topographic wetness index, a proxy for soil moisture storage. However, this relationship was highly dependent on the intensity of solar radiation, suggesting that at high elevations productivity was limited by temperature, while at low elevations productivity was limited by moisture. In order to identify the mechanisms responsible for this relationship, we then examined how different coniferous species respond to changing environmental and hydrologic regimes. We first examined transpiration and productivity rates at the hillslope scale at four plots, ranging in elevation and aspect across the watershed. We found trees growing in the hollows had higher transpiration and productivity rates than trees growing in the side slope, but that these differences were more pronounced at lower elevations. We then used oxygen isotope to examine water source use by different species across the watershed. We found that trees growing in the hollows used snowmelt for a longer period. This was most likely due to upslope subsidies of snowmelt water to the hollow areas. However, we found that trees growing at lower elevations used proportionally more snowmelt than trees at the higher elevations. This was most likely due to the trees at lower elevation depending on deeper, more reliable water when the upper soils dried down during midsummer. These observations suggest that landscape topography influences the availability of soil water, which influences tree transpiration and productivity rates, thereby leading to watershed patterns of productivity.

  16. Physiological responses and characteristics of table tennis matches determined in official tournaments.

    PubMed

    Zagatto, Alessandro M; Morel, Erika A; Gobatto, Claudio A

    2010-04-01

    The purpose of this study was to verify the physiological responses and the match characteristics of table tennis and also to compare these responses in 2 different performance-level athletes from official tournaments. Twenty male table tennis players (12 regional experience-RP and 8 national and international experience-NP) were participants in the study. Blood lactate concentration ([LAC]) and heart rate (HR) were measured as physiological parameters in 21 official table tennis matches, and other 12 matches had recorded the duration of rally (DR), rest time, effort and rest ratio (E:R), total playing time (TPT), effective playing time (EPT), and frequency of shots by video analyses. The [LAC] verified in all matches was 1.8 mmol.L (+/-0.8), whereas the [LAC] peak was 2.2 mmol.L (+/-0.8). There were no significant differences between the 2 groups (p > 0.05) in both parameters. The HR was 164 b.min (+/-14), corresponding to 81.2% (+/-7.4) of the predicted maximum HR. As characteristics of the matches, the DR corresponded to 3.4 seconds (+/-1.7), rest time to 8.1 seconds (+/-5.1), E:R to 0.4 (+/-0.2), TPT to 970.5 seconds (+/-336.1), EPT to 44.3% (+/-23.7), and frequency of shots to 35.3 balls.min (+/-7.7). Among groups, the rest time was lower in RP than in NP. Consistently, the E:R and EPT were higher in RP than in NP (p < 0.05). The results suggest that table tennis matches present the aerobic system as a principal output energy, the phosphagenic system being the most important during efforts. The information pertaining to the physiological profile and the characteristics of table tennis should be used by coaches planning physical training and specific exercise prescriptions aiming at achieving maximal sport performance. PMID:20300034

  17. Correlations between Morphological, Molecular Biological, and Physiological Characteristics in Clinical and Nonclinical Isolates of Acanthamoeba spp.

    PubMed Central

    Walochnik, Julia; Obwaller, Andreas; Aspöck, Horst

    2000-01-01

    Eleven Acanthamoeba isolates, obtained from Acanthamoeba keratitis patients, from contact lens cases of non-Acanthamoeba keratitis patients, from asymptomatic individuals, from necrotic tissue, and from tap water and two reference strains were investigated by morphological, molecular biological, and physiological means in order to discriminate clinically relevant and nonrelevant isolates. All clinically relevant isolates showed Acanthamoeba sp. group II morphology. 18S ribosomal DNA sequencing revealed sequence type T4 to be the most prevalent group among the isolates and also the group recruiting most of the pathogenic strains. Interestingly, within T4 the strains of no clinical relevance clustered together. Moreover, physiological properties appeared to be highly consistent with initial pathogenicity and with sequence clustering. Altogether, the results of our study indicate a correlation between the phylogenetic relationship and pathogenicity. PMID:11010891

  18. Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR-1.

    PubMed

    Wang, Xu; Wang, Qing; Zhang, Yang; Wang, Yinjia; Zhou, Yuan; Zhang, Weijia; Wen, Tong; Li, Li; Zuo, Meiqing; Zhang, Ziding; Tian, Jiesheng; Jiang, Wei; Li, Ying; Wang, Lei; Li, Jilun

    2016-06-01

    Magnetosome synthesis ability of Magnetospirillum gryphiswaldense MSR-1 in an autofermentor can be precisely controlled through strict control of dissolved oxygen concentration. In this study, using transcriptome data we discovered gene transcriptional differences and compared physiological characteristics of MSR-1 cells cultured under aerobic (high-oxygen) and micro-aerobic (low-oxygen) conditions. The results showed that 77 genes were up-regulated and 95 genes were down-regulated significantly under micro-aerobic situation. These genes were involved primarily in the categories of cell metabolism, transport, regulation and unknown-function proteins. The nutrient transport and physiological metabolism were slowed down under micro-aerobic condition, whereas dissimilatory denitrification pathways were activated and it may supplemental energy was made available for magnetosome synthesis. The result suggested that the genes of magnetosome membrane proteins (Mam and Mms) are not directly regulated by oxygen level, or are constitutively expressed. A proposed regulatory network of differentially expressed genes reflects the complexity of physiological metabolism in MSR-1, and suggests that some yet-unknown functional proteins play important roles such as ferric iron uptake and transport during magnetosome synthesis. The transcriptome data provides a holistic view of the responses of MSR-1 cells to differing oxygen levels. This approach will give new insights into general principles of magnetosome formation. PMID:27043321

  19. FISH PHYSIOLOGY, TOXICOLOGY AND WATER QUALITY MANAGEMENT: PROCEEDINGS OF 3RD BIENNIAL INTERNATIONAL SYMPOSIUM, NANJING, PRC

    EPA Science Inventory

    Scientists from four countries presented papers at the Third Biennial International Symposium on Fish Physiology, Toxicology and Water Quality Management, which was held on the campus of Nanjing University, Nanjing, Jiangsu Province, People's Republic of China. his proceedings in...

  20. Effects of age on the physiological and mechanical characteristics of human femoropopliteal arteries.

    PubMed

    Kamenskiy, Alexey V; Pipinos, Iraklis I; Dzenis, Yuris A; Phillips, Nicholas Y; Desyatova, Anastasia S; Kitson, Justin; Bowen, Robert; MacTaggart, Jason N

    2015-01-01

    Surgical and interventional therapies for peripheral artery disease (PAD) are notorious for high rates of failure. Interactions between the artery and repair materials play an important role, but comprehensive data describing the physiological and mechanical characteristics of human femoropopliteal arteries are not available. Fresh femoropopliteal arteries were obtained from 70 human subjects (13-79 years old), and in situ vs. excised arterial lengths were measured. Circumferential and longitudinal opening angles were determined for proximal superficial femoral, proximal popliteal and distal popliteal arteries. Mechanical properties were assessed by multi-ratio planar biaxial extension, and experimental data were used to calculate physiological stresses and stretches, in situ axial force and anisotropy. Verhoeff-Van Gieson-stained axial and transverse arterial sections were used for histological analysis. Most specimens demonstrated nonlinear deformations and were more compliant longitudinally than circumferentially. In situ axial pre-stretch decreased 0.088 per decade of life. In situ axial force and axial stress also decreased with age, but circumferential physiological stress remained constant. Physiological circumferential stretch decreased 55-75% after 45 years of age. Histology demonstrated a thickened external elastic lamina with longitudinally oriented elastin that was denser in smaller, younger arteries. Axial elastin likely regulates axial pre-stretch to help accommodate the complex deformations required of the artery wall during locomotion. Degradation and fragmentation of elastin as a consequence of age, cyclic mechanical stress and atherosclerotic arterial disease may contribute to decreased in situ axial pre-stretch, predisposing to more severe kinking of the artery during limb flexion and loss of energy-efficient arterial function. PMID:25301303

  1. [Effects of selenite addition on selenium absorption, root morphology and physiological characteristics of rape seedlings].

    PubMed

    Liu, Xin-wei; Wang, Qiao-lan; Duan, Bi-hui; Lin, Ya-meng; Zhao, Xiao-hu; Hu, Cheng-xiao; Zhao, Zhu-qing

    2015-07-01

    Abstract: The rape (Brassica napus L. cv. Xiangnongyou 571) was chosen as the experimental material to undergo solution cultivation at seedling stage to investigate the effects of selenite addition on the selenium (Se) absorption and distribution, root morphology and physiological characteristics of rape seedlings. The results showed that the bioaccumulation ability of Se decreased significantly with increasing the Se application rate, but the Se distribution coefficient remained around 0.9 with no significant influence. The application of 10 mol . L-1 selenite stimulated the growth of rape seedlings through improving the root physiological characteristics and root morphology significantly, including significantly increasing the production of superoxide radical (O2?-) rate and the activities of superoxide dismutase (SOD), peroxidase (POD) and fungal catalase (CAT) in the root system, which resulted in a reduction of the lipids peroxidation (MDA) content as much as 26.0%, consequently increasing the root activity as much as 17.4%. The promoting degrees of selenite on root morphological parameters were from strong to weak in such a tendency: root volume > total surface area > number of root forks > total root length > number of root tips > average diameter. However, such positive effects had no significant difference with those in treatment with 1 mol . L-1 selenite, indicating that small amounts (? 10 Lmol . L-1) of selenite were able to increase the activity of antioxidant enzymes and reduce the content of MDA in root system, which could increase root activity and improve root morphology, hence increased the biomass of rape seedlings. PMID:26710631

  2. Genetic and Physiological Controls of Growth under Water Deficit1

    PubMed Central

    Tardieu, François; Parent, Boris; Caldeira, Cecilio F.; Welcker, Claude

    2014-01-01

    The sensitivity of expansive growth to water deficit has a large genetic variability, which is higher than that of photosynthesis. It is observed in several species, with some genotypes stopping growth in a relatively wet soil, whereas others continue growing until the lower limit of soil-available water. The responses of growth to soil water deficit and evaporative demand share an appreciable part of their genetic control through the colocation of quantitative trait loci as do the responses of the growth of different organs to water deficit. This result may be caused by common mechanisms of action discussed in this paper (particularly, plant hydraulic properties). We propose that expansive growth, putatively linked to hydraulic processes, determines the sink strength under water deficit, whereas photosynthesis determines source strength. These findings have large consequences for plant modeling under water deficit and for the design of breeding programs. PMID:24569846

  3. AFM Structural Characterization of Drinking Water Biofilm under Physiological Conditions

    EPA Science Inventory

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air...

  4. Effect of Fresh Orange Juice Intake on Physiological Characteristics in Healthy Volunteers

    PubMed Central

    Asgary, Sedigheh; Keshvari, Mahtab; Afshani, Mohammad Reza; Javanmard, Shaghayegh Haghjooy

    2014-01-01

    Background. Impaired endothelial function is a predictor of cardiovascular events. Orange juice (OJ) is rich in dietary flavonoids and could inhibit oxidative stress and inflammatory responses. We examined the effects of commercial (COJ) and fresh orange juice (FOJ) on endothelial function and physiological characteristics in healthy humans. Materials and Methods. Twenty-two healthy volunteers years were enrolled in a single blind randomized crossover controlled trial. The two groups consumed either COJ for the first 4 weeks and then FOJ (CFOJ, 4 weeks), or FOJ for the first 4 weeks and then COJ (FCOJ, 4 weeks). We assessed endothelial function by measuring flow-mediated dilation, serum concentrations of lipids, apolipoproteins A and B (apo A-1 and apo B), and inflammatory markers such as vascular endothelial adhesion molecule 1 (VCAM-1), E-selectin, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6. Results. Consumption of both juices decreased VCAM, hs-CRP, and E-selectin but increased apo A-1. A decline in LDL occurred in the FOJ group. There were no differences between the characteristics of two groups, with the exception of apo A-1 levels that were increased with both forms of OJ. The largest variations occurred with hs-CRP, VCAM in both groups. Conclusion. Consumption of COJ and FOJ produced beneficial effects on the physiological characteristics of healthy volunteers. Although these results could encourage the consumption of OJ, intervention studies are needed to determine the long-term effects of these types of OJ on metabolic and cardiovascular endpoints. PMID:24967267

  5. Water uptake in barley grain: Physiology; genetics and industrial applications.

    PubMed

    Cu, Suong; Collins, Helen M; Betts, Natalie S; March, Timothy J; Janusz, Agnieszka; Stewart, Doug C; Skadhauge, Birgitte; Eglinton, Jason; Kyriacou, Bianca; Little, Alan; Burton, Rachel A; Fincher, Geoffrey B

    2016-01-01

    Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3;1,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3;1,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3;1,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries. PMID:26566843

  6. Characteristics of physiological inducers of the ethanol utilization (alc) pathway in Aspergillus nidulans.

    PubMed Central

    Flipphi, Michel; Kocialkowska, Janina; Felenbok, Béatrice

    2002-01-01

    The ethanol utilization (alc) pathway in Aspergillus nidulans is one of the strongest expressed gene systems in filamentous fungi. The pathway-specific activator AlcR requires the presence of an inducing compound to activate transcription of genes under its control. We have demonstrated recently that acetaldehyde is the sole physiological inducer of ethanol catabolism. In the present study we show that compounds with catabolism related to that of ethanol, i.e. primary alcohols, primary monoamines and l-threonine, act as inducers because their breakdown results in the production of inducing aliphatic aldehydes. Such aldehydes were shown to induce the alc genes efficiently at low external concentrations. When ethanol is mixed with representatives of another class of strong direct inducers, ketones, the physiological inducer, acetaldehyde, prevails as effector. Although direct inducers essentially carry a carbonyl function, not all aldehydes and ketones act as inducers. Structural features discriminating non-inducing from inducing compounds concern: (i) the length of the aliphatic side group(s); (ii) the presence and nature of any non-aliphatic substituent. These characteristics enable us to predict whether or not a given carbonyl compound will induce the alc genes. PMID:11988072

  7. Bioenergetics and thermal physiology of American water shrews (Sorex palustris).

    PubMed

    Gusztak, R W; Macarthur, R A; Campbell, K L

    2005-02-01

    Rates of O(2) consumption and CO(2) production, telemetered body temperature (T(b)) and activity level were recorded from adult and subadult water shrews (Sorex palustris) over an air temperature (T(a)) range of 3-32 degrees C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve a postabsorptive state. Of the 228 metabolic trials conducted on 15 water shrews, 146 (64%) were discarded because the criteria for inactivity were not met. Abdominal T(b) of S. palustris was independent of T(a) and averaged 38.64 +/- 0.07 degrees C. The thermoneutral zone extended from 21.2 degrees C to at least 32 degrees C. Our estimate of the basal metabolic rate for resting, postabsorptive water shrews (96.88 +/- 2.93 J g(-1) h(-1) or 4.84 +/- 0.14 ml O(2) g(-1) h(-1)) was three times the mass-predicted value, while their minimum thermal conductance in air (0.282 +/- 0.013 ml O(2) g(-1) h(-1)) concurred with allometric predictions. The mean digesta throughput time of water shrews fed mealworms (Tenebrio molitor) or ground meat was 50-55 min. The digestibility coefficients for metabolizable energy (ME) of water shrews fed stickleback minnows (Culaea inconstans) and dragonfly nymphs (Anax spp. and Libellula spp.) were 85.4 +/- 1.3% and 82.8 +/- 1.1%, respectively. The average metabolic rate (AMR) calculated from the gas exchange of six water shrews at 19-22 degrees C (208.0 +/- 17.0 J g(-1) h(-1)) was nearly identical to the estimate of energy intake (202.9 +/- 12.9 J g(-1) h(-1)) measured for these same animals during digestibility trials (20 degrees C). Based on 24-h activity trials and our derived ME coefficients, the minimum daily energy requirement of an adult (14.4 g) water shrew at T(a) = 20 degrees C is 54.0 kJ, or the energetic equivalent of 14.7 stickleback minnows. PMID:15592850

  8. Sugarcane growth and physiological responses to water deficit stress on organic and sand soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane (Saccharum spp.) genotype selection has been more successful for organic (muck) than sand soils in Florida, perhaps due to differences in water availability. A greenhouse study was conducted at Canal Point, Florida to compare sugarcane physiological responses to water deficit stress during...

  9. Physiological failures in Zea mays during water-stress: opportunities for improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maintaining high photosynthetic yield in water-stressed maize plants is a present priority for agriculture, and will likely increase in importance as key food producing regions become drier in the future. Although several physiological responses to water stress in maize have been studied in isolatio...

  10. An analysis of playing positions in elite men's volleyball: considerations for competition demands and physiologic characteristics.

    PubMed

    Sheppard, Jeremy M; Gabbett, Tim J; Stanganelli, Luiz-Claudio Reeberg

    2009-09-01

    The purpose of this study was to investigate the physiologic demands, physiologic characteristics, and jumping ability of different playing positions in elite male volleyball players. The first investigation involved an analysis of 16 international men's volleyball matches. The second investigation involved an analysis of the anthropometric and jump performance characteristics of 142 Development National Team (DNT) and Senior National Team (SNT) international volleyball players. Mean (+/-SD) frequency of block jumps for Middles (11.00 +/- 3.14) was significantly greater than for Setters (6.25 +/- 2.87, p < 0.001) and Outsides (6.50 +/- 3.16, p < 0.001). Attack jumps were performed more frequently by Middles (7.75 +/- 1.88), and this was found to be significantly more than for Setters (0.38 +/- 1.06, p < 0.001) and Outsides (5.75 +/- 3.25, p < 0.01). Middles were taller than Outsides and Setters (p < 0.001). Consequently, Middles had a significantly higher reach and greater body mass than Outsides (p < 0.001, p < 0.003) and Setters (p < 0.001, p < 0.001). Both Middles and Outsides had superior countermovement vertical jump (CMVJ) and spike jump (SPJ) scores compared with Setters (p < 0.001). Position-specific comparisons between DNT players and SNT players demonstrated that the SNT players were superior in relative CMVJ and SPJ scores (p < 0.05), with a large magnitude of effect (d > 0.99). The results of this study highlight the large jumping and landing demands placed on the taller and heavier players in the middle position. In addition to establishing the magnitude of difference in jumping ability between junior and senior national team players, the results also provide a comprehensive data set that may assist with talent identification and talent development for aspiring male volleyball players. PMID:19675472

  11. Physiological characteristics of tropical rain forest tree species: A basis for the development of silvicultural technology

    PubMed Central

    SASAKI, Satohiko

    2008-01-01

    The physiological characteristics of the dominant tree species in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp trees are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various species of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as “the steady state of the diffuse light” and “the turning point” were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of “the bare-root seedlings”, the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical trees by the field trial in the practical scale. Tolerance of the various species to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential species for regeneration of the tropical forests. PMID:18941286

  12. Physiological Characteristics and Anti-obesity Effect of Lactobacillus plantarum Q180 Isolated from Feces

    PubMed Central

    Park, Sun-Young; Cho, Seong-A; Kim, Sae-Hun; Lim, Sang-Dong

    2014-01-01

    Obesity is strongly associated with several metabolic and chronic diseases and has become a major public health problem of worldwide concern. This study aimed to investigate the physiological characteristics and anti-obesity effects of Lactobacillus plantarum Q180. Lactobacillus plantarum Q180 was isolated from the faces of healthy adults and found to have a lipase inhibitory activity of 83.61±2.32% and inhibited adipocyte differentiation of 3T3-L1 cells (14.63±1.37%) at a concentration of 100 μg/mL. The strain was investigated for its physiological characteristics. The optimum growth temperature of L. plantarum Q180 was 37℃. Lactobacillus plantarum Q180 showed higher sensitivity to novobiocin in a comparison of fifteen different antibiotics and showed the highest resistance to rifampicin, polymyxin B and vancomycin. The strain showed higher β-galactosidase and N-acetyl-β-glucosaminidase activities. It also did not produce carcinogenic enzymes such as β-glucuronidase. The survival rate of L. plantarum Q180 in MRS broth containing 0.3% bile was 97.8%. Moreover, the strain showed a 97.2% survival rate after incubation for 3 h in pH 2.0. Lactobacillus plantarum Q180 was displayed resistance to Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus with rates of 55.6%, 38.0% and 47.6%, respectively. These results demonstrate that L. plantarum Q180 has potential as a probiotic with anti-obesity effects. PMID:26761499

  13. The science of badminton: game characteristics, anthropometry, physiology, visual fitness and biomechanics.

    PubMed

    Phomsoupha, Michael; Laffaye, Guillaume

    2015-04-01

    Badminton is a racket sport for two or four people, with a temporal structure characterized by actions of short duration and high intensity. This sport has five events: men's and women's singles, men's and women's doubles, and mixed doubles, each requiring specific preparation in terms of technique, control and physical fitness. Badminton is one of the most popular sports in the world, with 200 million adherents. The decision to include badminton in the 1992 Olympics Game increased participation in the game. This review focuses on the game characteristics, anthropometry, physiology, visual attributes and biomechanics of badminton. Players are generally tall and lean, with an ectomesomorphic body type suited to the high physiological demands of a match. Indeed, a typical match characteristic is a rally time of 7 s and a resting time of 15 s, with an effective playing time of 31%. This sport is highly demanding, with an average heart rate (HR) of over 90% of the player's maximal HR. The intermittent actions during a game are demanding on both the aerobic and anaerobic systems: 60-70% on the aerobic system and approximately 30% on the anaerobic system, with greater demand on the alactic metabolism with respect to the lactic anaerobic metabolism. The shuttlecock has an atypical trajectory, and the players perform specific movements such as lunging and jumping, and powerful strokes using a specific pattern of movement. Lastly, badminton players are visually fit, picking up accurate visual information in a short time. Knowledge of badminton can help to improve coaching and badminton skills. PMID:25549780

  14. Methane emissions from beef and dairy cattle: quantifying the effect of physiological stage and diet characteristics.

    PubMed

    Ricci, P; Rooke, J A; Nevison, I; Waterhouse, A

    2013-11-01

    The prediction of methane outputs from ruminant livestock data at farm, national, and global scales is a vital part of greenhouse gas calculations. The objectives of this work were to quantify the effect of physiological stage (lactating or nonlactating) on predicting methane (CH4) outputs and to illustrate the potential improvement for a beef farming system of using more specific mathematical models to predict CH4 from cattle at different physiological stages and fed different diet types. A meta-analysis was performed on 211 treatment means from 38 studies where CH4, intake, animal, and feed characteristics had been recorded. Additional information such as type of enterprise, diet type, physiological stage, CH4 measurement technique, intake restriction, and CH4 reduction treatment application from these studies were used as classificatory factors. A series of equations for different physiological stages and diet types based on DMI or GE intake explained 96% of the variation in observed CH4 outputs (P<0.001). Resulting models were validated with an independent dataset of 172 treatment means from 20 studies. To illustrate the scale of improvement on predicted CH4 outputs from the current whole-farm prediction approach (Intergovernmental Panel on Climate Change [IPCC]), equations developed in the present study (NewEqs) were compared with the IPCC equation {CH4 (g/d)=[(GEI×Ym)×1,000]/55.65}, in which GEI is GE intake and Ym is the CH4 emission factor, in calculating CH4 outputs from 4 diverse beef systems. Observed BW and BW change data from cows with calves at side grazing either hill or lowland grassland, cows and overwintering calves and finishing steers fed contrasting diets were used to predict energy requirements, intake, and CH4 outputs. Compared with using this IPCC equation, NewEqs predicted up to 26% lower CH4 on average from individual lactating grazing cows. At the herd level, differences between equation estimates from 10 to 17% were observed in total annual accumulated CH4 when applied to the 4 diverse beef production systems. Overall, despite the small number of animals used it was demonstrated that there is a biological impact of using more specific CH4 prediction equations. Based on this approach, farm and national carbon budgets will be more accurate, contributing to reduced uncertainty in assessing mitigation options at farm and national level. PMID:24174549

  15. Physiological and functional characteristics of Propionibacterium strains of the poultry microbiota and relevance for the development of probiotic products.

    PubMed

    Argañaraz-Martínez, Eloy; Babot, Jaime D; Apella, María C; Perez Chaia, Adriana

    2013-10-01

    The prevention and control of pathogens colonization through probiotics administration in poultry feeding is of increasing interest. The genus Propionibacterium is an attractive candidate for the development of probiotic cultures as they produce short chain fatty acids (SCFA) by carbohydrates fermentation. The presence of strains of this genus in hens of conventional production systems and backyard hens was investigated. Propionibacteria were isolated from the intestine and identified by physiological and biochemical tests. PCR amplification of the 16S rRNA gene of the isolates was performed and products were compared with sequences from databases. The presence of the genus Propionibacterium was demonstrated in 26% of hens and Propionibacterium acidipropionici and Propionibacterium avidum were the identified species. A comparative study of their physiological and functional characteristics was performed. P. acidipropionici strains were the most resistant to in vitro gastrointestinal digestion, but the adhesion to intestinal tissue was strain dependent. Some differences were found between both species with respect to their growth and SCFA production in an in vitro cecal water model, but all the strains were metabolically active. The production of SCFA in cecal slurries inoculated with the strain P. acidipropionici LET 105 was 30% higher than in non-inoculated samples. SCFA concentrations obtained were high enough to inhibit Salmonella enterica serovar Enteritidis when assayed in a cecal water model. P. acidipropionici LET 105 was also able to compete with Salmonella for adhesion sites on the intestinal mucosa in ex vivo assays. Results contribute to the knowledge of the species diversity of the genus Propionibacterium in the intestine of poultry and provide evidence of their potential for probiotics products development. PMID:23973927

  16. Water Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Water Landing Characteristics of a Reentry Capsule. Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions. [Entire movie available on DVD from CASI as Doc ID 20070030955. Contact help@sti.nasa.gov

  17. Metabolic and Physiological Characteristics of Novel Cultivars from Serpentinite Seep Fluids

    NASA Astrophysics Data System (ADS)

    Nelson, B.; Chowdhury, S.; Brazelton, W. J.; Schrenk, M. O.

    2011-12-01

    Subsurface waters associated with the alteration of ultramafic rocks become highly reducing and alkaline through a process known as serpentinization. As habitat, these fluids are in many ways metabolically constraining but can provide sufficient energy for chemolithotrophy. As part of an ongoing effort to characterize these communities, heterotrophic enrichment cultures and anaerobic microcosms were initiated with alkaline waters found at three geographically and geochemically distinct sites of active serpentinization. These include the Northern Apennine ophiolite in the Ligurian region of Italy, the Tablelands ophiolite at Gros Morne National Park, Canada and the Coast Range ophiolite at McLaughlin Natural Reserve, California. Enrichment cultures at pH 11 yielded numerous isolates related to Proteobacteria and Firmicutes, some of which are closely related to other cultivars from high pH and subsurface environments. Anaerobic water samples were amended with combinations of electron donors (hydrogen, complex organics, acetate) and acceptors (ferric iron, sulfate) in a block design. After several weeks of incubation, DNA was extracted from cell concentrations and community differences were compared by TRFLP. Of particular interest is the isolation of a putative iron reducing Firmicute from samples enriched with complex organic compounds and ferric citrate. Ongoing studies are aimed at characterizing the physiology of these isolates. These data provide important insights into the metabolic potential of serpentinite subsurface ecosystems, and are a complement to culture-independent genomic analyses.

  18. Stomatal structure and physiology do not explain differences in water use among montane eucalypts.

    PubMed

    Gharun, Mana; Turnbull, Tarryn L; Pfautsch, Sebastian; Adams, Mark A

    2015-04-01

    Understanding the regulation of water use at the whole-tree scale is critical to advancing the utility of physiological ecology, for example in its role in predictive hydrology of forested catchments. For three eucalypt species that dominate high-elevation catchments in south-eastern Australia, we examined if whole-tree water use could be related to three widely discussed regulators of water use: stomatal anatomy, sensitivity of stomata [i.e. stomatal conductance (g(s))] to environmental influences, and sapwood area. While daily tree water use varied sixfold among species, sap velocity and sapwood area varied in parallel. Combined, stomatal structure and physiology could not explain differences in species-specific water use. Species which exhibited the fastest (Eucalyptus delegatensis) and slowest (Eucalyptus pauciflora) rates of water use both exhibited greater capacity for physiological control of g(s) [indicated by sensitivity to vapour pressure deficit (VPD)] and a reduced capacity to limit g(s) anatomically [indicated by greater potential g(s) (g(max))]. Conversely, g(s) was insensitive to VPD and g(max) was lowest for Eucalyptus radiata, the species showing intermediate rates of water use. Improved knowledge of stomatal anatomy will help us to understand the capacity of species to regulate leaf-level water loss, but seems likely to remain of limited use for explaining rates of whole-tree water use in montane eucalypts at the catchment scale. PMID:25669453

  19. Water Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions.

  20. Anthropometric and physiological characteristics of Melanesian futsal players: a first approach to talent identification in Oceania

    PubMed Central

    Zongo, P; Chamari, K; Chaouachi, A; Michalak, E; Dellal, A; Castagna, C; Hue, O

    2015-01-01

    This study assessed the anthropometric and physiological characteristics of elite Melanesian futsal players in order to determine the best performance predictors. Physiological parameters of performance were measured in 14 Melanesian (MEL-G, 24.4±4.4 yrs) and 8 Caucasian (NMEL-G, 22.9±4.9) elite futsal players, using tests of jump-and-reach (CMJ), agility (T-Test), repeated sprint ability (RSA), RSA with change-of-direction (RSA-COD), sprints with 5 m, 10 m, 15 m, and 30 m lap times, and aerobic fitness with the 30-15 intermittent fitness test (30-15 IFT). The anthropometric data revealed significantly lower height for MEL-G compared with NMEL-G: 1.73±0.05 and 1.80±0.08 m, respectively; P = 0.05. The CMJ was significantly higher for MEL-G than NMEL-G: 50.4±5.9 and 45.2±4.3 cm, respectively; P = 0.05. T-Test times were significantly lower for MEL-G than NMEL-G: 10.47±0.58 and 11.01±0.64 seconds, respectively; P = 0.05. MEL-G height was significantly related to CMJ (r = 0.706, P = 0.01), CMJpeakP (r = 0.709, P = 0.01) and T-Test (r = 0.589, P = 0.02). No significant between-group differences were observed for sprint tests or 30-15 IFT, including heart rate and estimated VO2max. Between groups, the percentage decrement (%Dec) in RSA-COD was significantly lower in MEL-G than NMEL-G (P = 0.05), although no significant difference was noted between RSA and RSA-COD. Within groups, no significant difference was observed between %Dec in RSA or RSA-COD; P = 0.697. This study presents specific anthropometric (significantly lower height) and physiological (significantly greater agility) reference values in Melanesians, which, taken together, might help coaches and physical fitness trainers to optimize elite futsal training and talent identification in Oceania. PMID:26060337

  1. Anthropometric and physiological characteristics of Melanesian futsal players: a first approach to talent identification in Oceania.

    PubMed

    Galy, O; Zongo, P; Chamari, K; Chaouachi, A; Michalak, E; Dellal, A; Castagna, C; Hue, O

    2015-06-01

    This study assessed the anthropometric and physiological characteristics of elite Melanesian futsal players in order to determine the best performance predictors. Physiological parameters of performance were measured in 14 Melanesian (MEL-G, 24.4±4.4 yrs) and 8 Caucasian (NMEL-G, 22.9±4.9) elite futsal players, using tests of jump-and-reach (CMJ), agility (T-Test), repeated sprint ability (RSA), RSA with change-of-direction (RSA-COD), sprints with 5 m, 10 m, 15 m, and 30 m lap times, and aerobic fitness with the 30-15 intermittent fitness test (30-15 IFT). The anthropometric data revealed significantly lower height for MEL-G compared with NMEL-G: 1.73±0.05 and 1.80±0.08 m, respectively; P = 0.05. The CMJ was significantly higher for MEL-G than NMEL-G: 50.4±5.9 and 45.2±4.3 cm, respectively; P = 0.05. T-Test times were significantly lower for MEL-G than NMEL-G: 10.47±0.58 and 11.01±0.64 seconds, respectively; P = 0.05. MEL-G height was significantly related to CMJ (r = 0.706, P = 0.01), CMJpeakP (r = 0.709, P = 0.01) and T-Test (r = 0.589, P = 0.02). No significant between-group differences were observed for sprint tests or 30-15 IFT, including heart rate and estimated VO2max. Between groups, the percentage decrement (%Dec) in RSA-COD was significantly lower in MEL-G than NMEL-G (P = 0.05), although no significant difference was noted between RSA and RSA-COD. Within groups, no significant difference was observed between %Dec in RSA or RSA-COD; P = 0.697. This study presents specific anthropometric (significantly lower height) and physiological (significantly greater agility) reference values in Melanesians, which, taken together, might help coaches and physical fitness trainers to optimize elite futsal training and talent identification in Oceania. PMID:26060337

  2. Fog and Rain Water Influences on Tree Physiology and Ecosystem Function in a California Redwood Forest

    NASA Astrophysics Data System (ADS)

    Ewing, H. A.; Weathers, K. C.; Dawson, T. E.; Templer, P. H.; Firestone, M. K.; Elliott, A. M.; Boukili, V. K.

    2008-12-01

    Fog is thought to influence ecological function in coastal forests worldwide, yet few data are available that illuminate the mechanisms underlying this influence. In a California redwood forest we measured water fluxes from horizontally moving fog and vertically delivered rain as well as redwood tree function. The spatial heterogeneity of water fluxes, water availability, tree water use, and water movement varied greatly across seasons. Across the forest as a whole, 98% of water flux to the soil occurred in the rain season and was relatively even across the whole forest. In contrast, below-canopy flux of fog water declined exponentially from the windward edge to the forest interior. Following large fog events, soil moisture was greater at the windward edge than anywhere else in the forest. Physiological activity in redwoods reflected these differences in inputs across seasons: tree physiological responses did not vary spatially in the rain season, but in the fog season, water use was greater, yet water stress was less, in trees at the windward edge of the forest versus the interior. In both seasons, vertical passage through the forest changed the amount of water, revealing the role of both the tree canopy and roots in processing atmospheric inputs. While total fog water inputs were comparatively small, they may have important ecosystem functions, including relief of canopy water stress and, where there is fog drip, functional coupling of above- and below-ground processes.

  3. Water protein dynamic coupling and new opportunities for probing it at low to physiological temperatures in aqueous solutions

    SciTech Connect

    Mamontov, Eugene; Chu, Xiang-Qiang

    2012-01-01

    Both the structure and dynamics of biomolecules are known to be essential for their biological function. In the dehydrated state, the function of biomolecules, such as proteins, is severely impeded, so hydration is required for bioactivity. The dynamics of the hydrated biomolecules and their hydration water are related - but how closely? The problem involves several layers of complexity. Even for water in the bulk state, the contribution from various dynamic components to the overall dynamics is not fully understood. In biological systems, the effects of confinement on the hydration water further complicate the picture. Even if the various components of the hydration water dynamics are properly understood, which of them are coupled to the protein dynamics, and how? The studies of protein dynamics over the wide temperature range, from physiological to low temperatures, provide some answers to these question. At low temperatures, both the protein and its hydration water behave as solids, with only vibrational degrees of freedom. As the temperature is increased, non-vibrational dynamic components start contributing to the measurable dynamics and eventually become dominant at physiological temperatures. Thus, the temperature dependence of the dynamics of protein and its hydration water may allow probing various dynamic components separately. In order to suppress the water freezing, the low-temperature studies of protein rely on either low-hydrated samples (essentially, hydrated protein powders), or cryo-protective solutions. Both approaches introduce the hydration environments not characteristic of the protein environments in living systems, which are typically aqueous protein solutions of various concentrations. In this paper, we discuss the coupling between the dynamic components of the protein and its hydration water by critical examining of the existing literature, and then propose that proteins can be studied in an aqueous solution that is remarkably similar in its dynamic properties to pure water, yet does not freeze down to about 200 K, even in the bulk form. The first experiment of this kind using quasielastic neutron scattering is discussed, and more experiments are proposed.

  4. Source parameters of the left ventricle related to the physiological characteristics of the cardiac muscle.

    PubMed Central

    Beyar, R; Sideman, S

    1986-01-01

    An attempt is made here to correlate the physiological muscle parameters with the dynamic source parameters of the left ventricle (LV), i.e. the source (isovolumic) pressure Po and the source (internal) resistance, Rs. The internal resistance is described here as a time-dependent parameter, corresponding to the pressure drop (from the theoretical instantaneous isovolumic pressure) associated with the instantaneous ejection flow rate. The source pressure, which relates to the muscle stress and the ventricular volume, is represented by the time-varying elastance concept and a spheroidal model relating the average wall stress to LV pressure. Linear and exponential force-velocity relationships (FVR), expressed in stress-strain rate terms, are compared. Two possible characteristics of the dynamic FVR in the partially active state, based on either a parallel or a fanlike shift of the stress-strain rate curve, are studied by utilizing simple analytical models as well as a computer simulation model. Comparing the calculated results with experimental data indicates that the dynamic FVR shift occurs in a fanlike pattern in which the maximum strain rate remains constant throughout the cycle. This pattern of the FVR shift is consistent with experimental data that show that the internal resistance is linearly related to the instantaneous isovolumic pressure. The analysis also indicates that the difference between the hyperbolic and linear FVR is rather minor, and in spite of some effects on the ejection pattern and the value of Rs, the functional shape has no effect on the global LV characteristics, such as the ejection fraction and stroke volume. PMID:3755065

  5. A novel ammonia-oxidizing archaeon from wastewater treatment plant: Its enrichment, physiological and genomic characteristics

    NASA Astrophysics Data System (ADS)

    Li, Yuyang; Ding, Kun; Wen, Xianghua; Zhang, Bing; Shen, Bo; Yang, Yunfeng

    2016-03-01

    Ammonia-oxidizing archaea (AOA) are recently found to participate in the ammonia removal processes in wastewater treatment plants (WWTPs), similar to their bacterial counterparts. However, due to lack of cultivated AOA strains from WWTPs, their functions and contributions in these systems remain unclear. Here we report a novel AOA strain SAT1 enriched from activated sludge, with its physiological and genomic characteristics investigated. The maximal 16S rRNA gene similarity between SAT1 and other reported AOA strain is 96% (with “Ca. Nitrosotenuis chungbukensis”), and it is affiliated with Wastewater Cluster B (WWC-B) based on amoA gene phylogeny, a cluster within group I.1a and specific for activated sludge. Our strain is autotrophic, mesophilic (25 °C–33 °C) and neutrophilic (pH 5.0–7.0). Its genome size is 1.62 Mb, with a large fragment inversion (accounted for 68% genomic size) inside. The strain could not utilize urea due to truncation of the urea transporter gene. The lack of the pathways to synthesize usual compatible solutes makes it intolerant to high salinity (>0.03%), but could adapt to low salinity (0.005%) environments. This adaptation, together with possibly enhanced cell-biofilm attachment ability, makes it suitable for WWTPs environment. We propose the name “Candidatus Nitrosotenuis cloacae” for the strain SAT1.

  6. Insight into characteristic features of cartilage growth plate as a physiological template for bone formation.

    PubMed

    Jaroszewicz, Jakub; Kosowska, Anna; Hutmacher, Dietmar; Swieszkowski, Wojciech; Moskalewski, Stanisław

    2016-02-01

    Cartilage growth plate is a natural template from both a biochemical and structural point of view and allows osteoblasts migration, proliferation, differentiation, and ultimately, bone formation. It is evolutionary adjusted to support bone formation within strictly defined spatial framework serving as an interesting model for studying more mechanistically aspects which might be important for specific scaffold-based bone tissue engineering strategies. Surprisingly little is known about the geometric features of this physiological template. To this purpose we analyzed cartilage growth plate from rat, mouse, and human costochondral junction and tibia. High-resolution X-ray tomography showed that pore size in the zone of provisional calcification was within 20 to 30 µm range and in the metaphysis in 35 to 50 µm range. The thickness of calcified longitudinal septa in zone of provisional calcification was 3 to 5 µm and in metaphysis 7 to 12 µm. The porosity varied from 84 to 88%. We observed that numerical values characteristic for cartilage growth plate were not significantly influenced by the species of origin, by the type of bone, or by age. In addition, electron microscopy of calcified fragments of longitudinal septa showed that the calcium aggregates were globular, connected with each other, and formed a shell covering cartilage matrix located within longitudinal septa. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 357-366, 2016. PMID:26453900

  7. Physiology and molecular characteristics of a pine wilt nematode-trapping fungus, Monacrosporium megalosporum.

    PubMed

    Kano, Sanae; Aimi, Tadanori; Masumoto, Seita; Kitamoto, Yutaka; Morinaga, Tsutomu

    2004-09-01

    We isolated the nematode-trapping fungus Monacrosporium megalosporum from nature and examined its morphology, physiology and molecular characteristics. The nematode-trapping device of this fungus is a three-dimensional network. This fungus captures the pine wilt nematode (Bursaphelenchus xylophilus), but not a non-phytopathogenic nematode that is morphologically similar to B. xylophilus. The phylogenic relationship of the nucleotide sequence of the rDNA ITS region was close to those of M. thaumasium and Geniculifera eudermata, which also have nematode-trapping devices that are three-dimensional networks. Acidic pH inhibited both the liberation and regeneration of protoplasts. Moreover, cytoplasmic granulation of protoplasts was found below pH 6.0. Mycelial growth on agar media was also inhibited below pH 4, but not at pH 9. These results strongly suggest that the activity of this fungus is inhibited by acid rain in the field. Therefore, development of pine wilt disease might be a secondary effect of acid rain. PMID:15386097

  8. [Effects of allelochemicals ethyl cinnamate on the growth and physiological characteristics of Chlorella pyrenoidosa].

    PubMed

    Gao, Li-Li; Guo, Pei-Yong; Su, Guang-Ming; Wei, Yan-Fang

    2013-01-01

    The effects of ethyl cinnamate on the growth and physiological characteristics of Chlorella pyrenoidosa were studied. The allelopathic mechanisms were explored, from views of chlorophyll a content, antioxidant enzyme activities, reactive oxygen species (ROS) level, malondialdehyde (MDA) content and photosynthetic activity. The results revealed that ethyl cinnamate had acute inhibitory effects on the growth of Chlorella pyrenoidosa, and the inhibited degree tended to increase with increased concentrations. The effective concentration causing a 50% inhibition at 96 h was 5.45 mg c L(-1). Ethyl cinnamate induced the decrease of chlorophyll a, the over-accumulation of ROS and the increase of MDA. Therefore, it suggested that ethyl cinnamate could lead to the damage of cell membrane system and metabolic disorder through inducing lipid peroxidation via initiating ROS overproduction. And for scavenging ROS, the algae cells were protected from oxidative damages through increasing the activity of antioxidant enzymes. The results demonstrated ethyl cinnamate had acute inhibition to the maximum quantum yield and the potential activity of photosystem II of Chlorella pyrenoidosa, however, the photosynthetic activity could recover to some extent through self-regulation after some time. PMID:23487932

  9. A novel ammonia-oxidizing archaeon from wastewater treatment plant: Its enrichment, physiological and genomic characteristics

    PubMed Central

    Li, Yuyang; Ding, Kun; Wen, Xianghua; Zhang, Bing; Shen, Bo; Yang, Yunfeng

    2016-01-01

    Ammonia-oxidizing archaea (AOA) are recently found to participate in the ammonia removal processes in wastewater treatment plants (WWTPs), similar to their bacterial counterparts. However, due to lack of cultivated AOA strains from WWTPs, their functions and contributions in these systems remain unclear. Here we report a novel AOA strain SAT1 enriched from activated sludge, with its physiological and genomic characteristics investigated. The maximal 16S rRNA gene similarity between SAT1 and other reported AOA strain is 96% (with “Ca. Nitrosotenuis chungbukensis”), and it is affiliated with Wastewater Cluster B (WWC-B) based on amoA gene phylogeny, a cluster within group I.1a and specific for activated sludge. Our strain is autotrophic, mesophilic (25 °C–33 °C) and neutrophilic (pH 5.0–7.0). Its genome size is 1.62 Mb, with a large fragment inversion (accounted for 68% genomic size) inside. The strain could not utilize urea due to truncation of the urea transporter gene. The lack of the pathways to synthesize usual compatible solutes makes it intolerant to high salinity (>0.03%), but could adapt to low salinity (0.005%) environments. This adaptation, together with possibly enhanced cell-biofilm attachment ability, makes it suitable for WWTPs environment. We propose the name “Candidatus Nitrosotenuis cloacae” for the strain SAT1. PMID:27030530

  10. Effects of Shade Treatments on Photosynthetic Characteristics, Chloroplast Ultrastructure, and Physiology of Anoectochilus roxburghii

    PubMed Central

    Shao, Qingsong; Wang, Hongzhen; Guo, Haipeng; Zhou, Aicun; Huang, Yuqiu; Sun, Yulu; Li, Mingyan

    2014-01-01

    Anoectochilus roxburghii was grown under different shade treatments–50%, 30%, 20%, and 5% of natural irradiance–to evaluate its photosynthetic characteristics, chloroplast ultrastructure, and physiology. The highest net photosynthetic rates and stomatal conductance were observed under 30% irradiance, followed in descending order by 20%, 5%, and 50% treatments. As irradiance decreased from 50% to 30%, electron transport rate and photochemical quenching increased, while non-photochemical quenching indexes declined. Reductions in irradiance significantly increased Chl a and Chl b contents and decreased Chl a/b ratios. Chloroplast ultrastructure generally displayed the best development in leaves subjected to 30% irradiance. Under 50% irradiance, leaf protein content remained relatively stable during the first 20 days of treatment, and then increased rapidly. The highest peroxidase and superoxide dismutase levels, and the lowest catalase activities, were observed in plants subjected to the 50% irradiance treatment. Soluble sugar and malondialdehyde contents were positively correlated with irradiance levels. Modulation of chloroplast development, accomplished by increasing the number of thylakoids and grana containing photosynthetic pigments, is an important shade tolerance mechanism in A. roxburghii. PMID:24516523

  11. Effects of shade treatments on photosynthetic characteristics, chloroplast ultrastructure, and physiology of Anoectochilus roxburghii.

    PubMed

    Shao, Qingsong; Wang, Hongzhen; Guo, Haipeng; Zhou, Aicun; Huang, Yuqiu; Sun, Yulu; Li, Mingyan

    2014-01-01

    Anoectochilus roxburghii was grown under different shade treatments-50%, 30%, 20%, and 5% of natural irradiance-to evaluate its photosynthetic characteristics, chloroplast ultrastructure, and physiology. The highest net photosynthetic rates and stomatal conductance were observed under 30% irradiance, followed in descending order by 20%, 5%, and 50% treatments. As irradiance decreased from 50% to 30%, electron transport rate and photochemical quenching increased, while non-photochemical quenching indexes declined. Reductions in irradiance significantly increased Chl a and Chl b contents and decreased Chl a/b ratios. Chloroplast ultrastructure generally displayed the best development in leaves subjected to 30% irradiance. Under 50% irradiance, leaf protein content remained relatively stable during the first 20 days of treatment, and then increased rapidly. The highest peroxidase and superoxide dismutase levels, and the lowest catalase activities, were observed in plants subjected to the 50% irradiance treatment. Soluble sugar and malondialdehyde contents were positively correlated with irradiance levels. Modulation of chloroplast development, accomplished by increasing the number of thylakoids and grana containing photosynthetic pigments, is an important shade tolerance mechanism in A. roxburghii. PMID:24516523

  12. A novel ammonia-oxidizing archaeon from wastewater treatment plant: Its enrichment, physiological and genomic characteristics.

    PubMed

    Li, Yuyang; Ding, Kun; Wen, Xianghua; Zhang, Bing; Shen, Bo; Yang, Yunfeng

    2016-01-01

    Ammonia-oxidizing archaea (AOA) are recently found to participate in the ammonia removal processes in wastewater treatment plants (WWTPs), similar to their bacterial counterparts. However, due to lack of cultivated AOA strains from WWTPs, their functions and contributions in these systems remain unclear. Here we report a novel AOA strain SAT1 enriched from activated sludge, with its physiological and genomic characteristics investigated. The maximal 16S rRNA gene similarity between SAT1 and other reported AOA strain is 96% (with "Ca. Nitrosotenuis chungbukensis"), and it is affiliated with Wastewater Cluster B (WWC-B) based on amoA gene phylogeny, a cluster within group I.1a and specific for activated sludge. Our strain is autotrophic, mesophilic (25 °C-33 °C) and neutrophilic (pH 5.0-7.0). Its genome size is 1.62 Mb, with a large fragment inversion (accounted for 68% genomic size) inside. The strain could not utilize urea due to truncation of the urea transporter gene. The lack of the pathways to synthesize usual compatible solutes makes it intolerant to high salinity (>0.03%), but could adapt to low salinity (0.005%) environments. This adaptation, together with possibly enhanced cell-biofilm attachment ability, makes it suitable for WWTPs environment. We propose the name "Candidatus Nitrosotenuis cloacae" for the strain SAT1. PMID:27030530

  13. Identification of Physiological Traits for Early Detecting Water Deficit Stress in Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane (Saccharum spp.) genotype selection has been more successful for organic (muck) than sand soils in Florida. Water deficit stress during its formative growth phase may limit sugarcane growth and yields on Florida sand soils. Therefore, identifying proper physiological traits will help scien...

  14. Genotypic differences in architectural and physiological responses to water restriction in rose bush

    PubMed Central

    Li-Marchetti, Camille; Le Bras, Camille; Relion, Daniel; Citerne, Sylvie; Huché-Thélier, Lydie; Sakr, Soulaiman; Morel, Philippe; Crespel, Laurent

    2015-01-01

    The shape and, therefore, the architecture of the plant are dependent on genetic and environmental factors such as water supply. The architecture determines the visual quality, a key criterion underlying the decision to purchase an ornamental potted plant. The aim of this study was to analyze genotypic responses of eight rose bush cultivars to alternation of water restriction and re-watering periods, with soil water potential of -20 and -10 kPa respectively. Responses were evaluated at the architectural level through 3D digitalization using six architectural variables and at the physiological level by measuring stomatal conductance, water content, hormones [abscisic acid (ABA), auxin, cytokinins, jasmonic acid, and salicylic acid (SA)], sugars (sucrose, fructose, and glucose), and proline. Highly significant genotype and watering effects were revealed for all the architectural variables measured, as well as genotype × watering interaction, with three distinct genotypic architectural responses to water restriction – weak, moderate and strong – represented by Hw336, ‘Baipome’ and ‘The Fairy,’ respectively. The physiological analysis explained, at least in part, the more moderate architectural response of ‘Baipome’ compared to ‘The Fairy,’ but not that of Hw336 which is an interspecific hybrid. Such physiological responses in ‘Baipome’ could be related to: (i) the maintenance of the stimulation of budbreak and photosynthetic activity during water restriction periods due to a higher concentration in conjugated cytokinins (cCK) and to a lower concentration in SA; (ii) a better resumption of budbreak during the re-watering periods due to a lower concentration in ABA during this period. When associated with the six architectural descriptors, cCK, SA and ABA, which explained the genotypic differences in this study, could be used as selection criteria for breeding programs aimed at improving plant shape and tolerance to water restriction. PMID:26074929

  15. Physical and Physiological Characteristics of Elite Male Handball Players from Teams with a Different Ranking

    PubMed Central

    Nikolaidis, Pantelis T.; Ingebrigtsen, Jørgen

    2013-01-01

    The aim of this study was to examine possible discriminant physical and physiological characteristics between elite male handball players from elite teams with different league rankings. Players from three teams (A, B and C), which competed in the first league of the Greek championship during the season 2011–2012 participated in the study. Team A finished first, B came second and C came eighth out of eleven clubs. Teams A and B also participated in European Cups, and team A won the European Challenge Cup. The players (n=44) were examined for anthropometric characteristics and performed a series of physical fitness tests. Players from teams A and B were taller (6.2 cm (0.7;11.7), mean difference (95% CI) and 9.2 cm (4.0;14.5), respectively), and had a higher amount of fat free mass (6.4 kg (1.1;11.8) and 5.4 kg (0.2;10.5)) compared to those of team C. Players from team A performed better than players from team C in the squat jump (5.5 cm (1.0;10.0)), the countermovement jump without (5.5 cm (0.4;10.6)) and with arm-swing (6.0 cm (0.7;11.3)) and in the 30 s Bosco test (5.7 W·kg−1 (1.2;10.2)). Also, players from team A outperformed team B in mean power during the Wingate anaerobic test (WAnT, 0.5 W·kg−1(0;0.9)) and in the Bosco test (7.8 W·kg−1 (3.4;12.2)). Overall, players from the best ranked team performed better than the lowest ranked team on WAnT, vertical jumps and the Bosco test. Stepwise discriminant analysis showed that stature and mean power during the Bosco test were the most important characteristics in TH players, accounting for 54.6% of the variance in team ranking. These findings indicate the contribution of particular physical fitness components (stature, fat free mass and anaerobic power) to excellence in TH. In addition, the use of the Bosco test as an assessment tool in talent identification and physical fitness monitoring in this sport is further recommended. PMID:24235989

  16. Demographic, Physiologic and Radiographic Characteristics of COPD Patients Taking Chronic Systemic Corticosteroids

    PubMed Central

    Swift, I.; Satti, A.; Kim, V.; Make, B.J.; Newell, J.; Steiner, R.M.; Wilson, C.; Murphy, J.; Silverman, EK; Criner, G.J.

    2013-01-01

    Long-term therapy with systemic corticosteroids is not recommended in the treatment of chronic obstructive pulmonary disease (COPD). However, experience demonstrates that some patients receive low dose therapy. Our objective was to describe the demographic, physiologic and radiologic characteristics of COPD patients treated with chronic systemic corticosteroids. We analyzed COPD subjects with GOLD I–IV disease in the COPDGene® study. Subjects were divided into two groups based on whether they reported using chronic oral steroids or not. 1264 subjects were included. 58 (4.5%) reported chronic systemic corticosteroid use. There were no differences in age, race, comorbid conditions (other than asthma), or body mass index between the groups. There was a greater proportion of GOLD III (41% vs. 26%) and IV (41% vs. 13%) subjects in the group using chronic systemic corticosteroids. This group used more respiratory medications, required more oxygen (2.31±0.21 vs. 0.59±0.05 L/min; p<0.0001), and walked less distance (245.4±17.4 vs. 367.2±3.9 meters; p<0.0001). They reported more total (1.7±0.16 vs. 0.62±0.03; p<0.0001) and severe exacerbations per year (0.41±0.05 vs. 0.18 ± 0.01; p<0.0001). BODE (5.0±0.3 vs. 2.6±0.1; p<0.0001), MMRC (3.31±0.19 vs. 1.90±0.04; p<0.0001) and SGRQ scores (54.9±2.9 vs 53.3±0.6; p<0.0001) were higher. They also had a higher percentage of emphysema (22.4±1.9 vs. 14.0±0.4; %, p=<0.0001) on CT scan. COPD patients that report using chronic systemic corticosteroids have more severe clinical, physiologic, and radiographic disease. PMID:22292596

  17. Demographic, physiologic and radiographic characteristics of COPD patients taking chronic systemic corticosteroids.

    PubMed

    Swift, Irene; Satti, Aditi; Kim, Victor; Make, Barry J; Newell, John; Steiner, Robert M; Wilson, Carla; Murphy, James R; Silverman, Edwin K; Criner, Gerard J

    2012-02-01

    Long-term therapy with systemic corticosteroids is not recommended in the treatment of chronic obstructive pulmonary disease (COPD). However, experience demonstrates that some patients receive low dose therapy. Our objective was to describe the demographic, physiologic and radiologic characteristics of COPD patients treated with chronic systemic corticosteroids. We analyzed COPD subjects with GOLD I-IV disease in the COPDGene study. Subjects were divided into 2 groups based on whether they reported using chronic oral steroids or not; 1264 subjects were included. Fifty-eight (4.5%) reported chronic systemic corticosteroid use. There were no differences in age, race, co-morbid conditions (other than asthma), or body mass index between the groups. There was a greater proportion of GOLD III (41% vs. 26%) and IV (41% vs. 13%) subjects in the group using chronic systemic corticosteroids. This group used more respiratory medications, required more oxygen (2.31 0.21 vs. 0.59 0.05 L/min; p < 0.0001), and walked less distance (245.4 17.4 vs. 367.2 3.9 meters; p < 0.0001). They reported more total (1.7 0.16 vs. 0.62 0.03; p < 0.0001) and severe exacerbations per year (0.41 0.05 vs. 0.18 0.01; p < 0.0001). BODE (5.0 0.3 vs. 2.6 0.1; p < 0.0001), MMRC (3.31 0.19 vs. 1.90 0.04; p < 0.0001) and SGRQ scores (54.9 2.9 vs 53.3 0.6; p < 0.0001) were higher. They also had a higher percentage of emphysema (22.4 1.9 vs. 14.0 0.4;%, p = <0.0001) on CT scan. COPD patients that report using chronic systemic corticosteroids have more severe clinical, physiologic, and radiographic disease. PMID:22292596

  18. Physiological Plasticity to Water Flow Habitat in the Damselfish, Acanthochromis polyacanthus: Linking Phenotype to Performance

    PubMed Central

    Binning, Sandra A.; Ros, Albert F. H.; Nusbaumer, David; Roche, Dominique G.

    2015-01-01

    The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1) whether aspects of swimming physiology and morphology show plastic responses to water flow, 2) whether trait divergence correlates with swimming performance and 3) whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology. PMID:25807560

  19. Physiological plasticity to water flow habitat in the damselfish, Acanthochromis polyacanthus: linking phenotype to performance.

    PubMed

    Binning, Sandra A; Ros, Albert F H; Nusbaumer, David; Roche, Dominique G

    2015-01-01

    The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1) whether aspects of swimming physiology and morphology show plastic responses to water flow, 2) whether trait divergence correlates with swimming performance and 3) whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology. PMID:25807560

  20. [Effects of sodium naphthalene acetate on growth and physiological characteristics of tomato seedlings under suboptimal temperature and light condition].

    PubMed

    Guo, Yun-na; Li, Yan-su; He, Chao-xing; Yu, Xian-chang

    2015-10-01

    Taking tomato 'Zhongza 105' as test material, the influences of sodium naphthalene acetate (SNA) on growth and physiological characteristics of tomato seedlings under suboptimal temperature and light condition were investigated. The results showed that the dry mass, vigorous seedling index, root activity, total nitrogen content, net photosynthesis rate (Pn) of tomato seedlings were significantly decreased by suboptimum temperature and light treatment. In addition, the catalase activity and zeatin riboside (ZR) concentration were also reduced. However, the superoxide dismutase, peroxidase activity and the content of abscisic acid (ABA) were increased. Compared with treatment of the same volume distilled water on tomato seedlings under suboptimum temperature and light condition, the dry mass of whole plant and vigorous seedling index of tomato seedlings were significantly increased by 16.4% and 22.9%, as the total N contents in roots and leaves and Pn were also increased by 8.5%, 28.5%and 37.0%, respectively, with the treatment of root application of 10 mg . L-1 SNA. Besides protective enzyme activity and the root activity were improved, the indole acetic acid (IAA) and ZR concentration of tomato were raised, and ABA concentration was reduced. The results indicated that root application of certain concentration of SNA could promote the growth of tomato seedlings by increasing the tomato root activity, protective enzymes activity, Pn and regulating endogenous hormone concentration under suboptimum temperature and light condition. PMID:26995913

  1. Physiological Characteristics Underlying the Distribution Patterns of Luminous Bacteria in the Mediterranean Sea and the Gulf of Elat

    PubMed Central

    Shilo, M.; Yetinson, T.

    1979-01-01

    Physiological characteristics of luminous bacteria isolated from the Mediterranean and Gulf of Elat were compared to determine their relationship to the specific seasonal and geographic distribution patterns of these bacteria. The effects of temperature on growth rate and yield, relative sensitivity to photooxidation, resistance to high salt concentration (8%), and ability to grow in nutrient-poor conditions appear to control these patterns. The winter appearance of Photobacterium fischeri and the succession of winter and summer types of Beneckea harveyi in the eastern Mediterranean are explained by different temperature requirements for growth. Sensitivity to photooxidation explains the disappearance of P. leiognathi, present in the main body of the Gulf of Elat throughout the year, from the shallow coastal strip. B. harveyi is present in this coastal strip which is higher in nutrients and in productivity than the open waters. Competition experiments between B. harveyi and P. leiognathi in batch and continuous culture indicate that the oligotrophic P. leiognathi is outcompeted by B. harveyi in rich and even in relatively poor media. The distribution pattern found in the Bardawil hypersaline lagoon is explained by selection of salinity-resistant mutants of B. harveyi from the Mediterranean Sea. PMID:16345442

  2. Physiological characteristics underlying the distribution patterns of luminous bacteria in the mediterranean sea and the gulf of elat.

    PubMed

    Shilo, M; Yetinson, T

    1979-10-01

    Physiological characteristics of luminous bacteria isolated from the Mediterranean and Gulf of Elat were compared to determine their relationship to the specific seasonal and geographic distribution patterns of these bacteria. The effects of temperature on growth rate and yield, relative sensitivity to photooxidation, resistance to high salt concentration (8%), and ability to grow in nutrient-poor conditions appear to control these patterns. The winter appearance of Photobacterium fischeri and the succession of winter and summer types of Beneckea harveyi in the eastern Mediterranean are explained by different temperature requirements for growth. Sensitivity to photooxidation explains the disappearance of P. leiognathi, present in the main body of the Gulf of Elat throughout the year, from the shallow coastal strip. B. harveyi is present in this coastal strip which is higher in nutrients and in productivity than the open waters. Competition experiments between B. harveyi and P. leiognathi in batch and continuous culture indicate that the oligotrophic P. leiognathi is outcompeted by B. harveyi in rich and even in relatively poor media. The distribution pattern found in the Bardawil hypersaline lagoon is explained by selection of salinity-resistant mutants of B. harveyi from the Mediterranean Sea. PMID:16345442

  3. Physiological, anatomical and transcriptional alterations in a rice mutant leading to enhanced water stress tolerance.

    PubMed

    Lima, John Milton; Nath, Manoj; Dokku, Prasad; Raman, K V; Kulkarni, K P; Vishwakarma, C; Sahoo, S P; Mohapatra, U B; Mithra, S V Amitha; Chinnusamy, V; Robin, S; Sarla, N; Seshashayee, M; Singh, K; Singh, A K; Singh, N K; Sharma, R P; Mohapatra, T

    2015-01-01

    Water stress is one of the most severe constraints to crop productivity. Plants display a variety of physiological and biochemical responses both at the cellular and whole organism level upon sensing water stress. Leaf rolling, stomatal closure, deeper root penetration, higher relative water content (RWC) and better osmotic adjustment are some of the mechanisms that plants employ to overcome water stress. In the current study, we report a mutant, enhanced water stress tolerant1 (ewst1) with enhanced water stress tolerance, identified from the ethyl methanesulfonate-induced mutant population of rice variety Nagina22 by field screening followed by withdrawal of irrigation in pots and hydroponics (PEG 6000). Though ewst1 was morphologically similar to the wild type (WT) for 35 of the 38 morphological descriptors (except chalky endosperm/expression of white core, decorticated grain colour and grain weight), it showed enhanced germination in polyethylene glycol-infused medium. It exhibited increase in maximum root length without any significant changes in its root weight, root volume and total root number on crown when compared with the WT under stress in PVC tube experiment. It also showed better performance for various physiological parameters such as RWC, cell membrane stability and chlorophyll concentration upon water stress in a pot experiment. Root anatomy and stomatal microscopic studies revealed changes in the number of xylem and phloem cells, size of central meta-xylem and number of closed stomata in ewst1. Comparative genome-wide transcriptome analysis identified genes related to exocytosis, secondary metabolites, tryptophan biosynthesis, protein phosphorylation and other signalling pathways to be playing a role in enhanced response to water stress in ewst1. The possible involvement of a candidate gene with respect to the observed morpho-physiological and transcriptional changes and its role in stress tolerance are discussed. The mutant identified and characterized in this study will be useful for further dissection of water stress tolerance in rice. PMID:25818072

  4. Physiological, anatomical and transcriptional alterations in a rice mutant leading to enhanced water stress tolerance

    PubMed Central

    Lima, John Milton; Nath, Manoj; Dokku, Prasad; Raman, K. V.; Kulkarni, K. P.; Vishwakarma, C.; Sahoo, S. P.; Mohapatra, U. B.; Mithra, S. V. Amitha; Chinnusamy, V.; Robin, S.; Sarla, N.; Seshashayee, M.; Singh, K.; Singh, A. K.; Singh, N. K.; Sharma, R. P.; Mohapatra, T.

    2015-01-01

    Water stress is one of the most severe constraints to crop productivity. Plants display a variety of physiological and biochemical responses both at the cellular and whole organism level upon sensing water stress. Leaf rolling, stomatal closure, deeper root penetration, higher relative water content (RWC) and better osmotic adjustment are some of the mechanisms that plants employ to overcome water stress. In the current study, we report a mutant, enhanced water stress tolerant1 (ewst1) with enhanced water stress tolerance, identified from the ethyl methanesulfonate-induced mutant population of rice variety Nagina22 by field screening followed by withdrawal of irrigation in pots and hydroponics (PEG 6000). Though ewst1 was morphologically similar to the wild type (WT) for 35 of the 38 morphological descriptors (except chalky endosperm/expression of white core, decorticated grain colour and grain weight), it showed enhanced germination in polyethylene glycol-infused medium. It exhibited increase in maximum root length without any significant changes in its root weight, root volume and total root number on crown when compared with the WT under stress in PVC tube experiment. It also showed better performance for various physiological parameters such as RWC, cell membrane stability and chlorophyll concentration upon water stress in a pot experiment. Root anatomy and stomatal microscopic studies revealed changes in the number of xylem and phloem cells, size of central meta-xylem and number of closed stomata in ewst1. Comparative genome-wide transcriptome analysis identified genes related to exocytosis, secondary metabolites, tryptophan biosynthesis, protein phosphorylation and other signalling pathways to be playing a role in enhanced response to water stress in ewst1. The possible involvement of a candidate gene with respect to the observed morpho-physiological and transcriptional changes and its role in stress tolerance are discussed. The mutant identified and characterized in this study will be useful for further dissection of water stress tolerance in rice. PMID:25818072

  5. Physiological and growth responses to water deficit in the bioenergy crop Miscanthus x giganteus

    PubMed Central

    Ings, Jennifer; Mur, Luis A. J.; Robson, Paul R. H.; Bosch, Maurice

    2013-01-01

    High yielding perennial biomass crops of the species Miscanthus are widely recognized as one of the most promising lignocellulosic feedstocks for the production of bioenergy and bioproducts. Miscanthus is a C4 grass and thus has relatively high water use efficiency. Cultivated Miscanthus comprises primarily of a single clone, Miscanthus x giganteus, a sterile hybrid between M. sacchariflorus and M. sinensis. M. x giganteus is high yielding and expresses desirable combinations of many traits present in the two parental species types; however, it responds poorly to low water availability. To identify the physiological basis of the response to water stress in M. x giganteus and to identify potential targets for breeding improvements we characterized the physiological responses to water-deficit stress in a pot experiment. The experiment has provided valuable insights into the temporal aspects of drought-induced responses of M. x giganteus. Withholding water resulted in marked changes in plant physiology with growth-associated traits among the first affected, the most rapid response being a decline in the rate of stem elongation. A reduction in photosynthetic performance was among the second set of changes observed; indicated by a decrease in stomatal conductance followed by decreases in chlorophyll fluorescence and chlorophyll content. Measures reflecting the plant water status were among the last affected by the drought treatment. Metabolite analysis indicated that proline was a drought stress marker in M. x giganteus, metabolites in the proline synthesis pathway were more abundant when stomatal conductance decreased and dry weight accumulation ceased. The outcomes of this study in terms of drought-induced physiological changes, accompanied by a proof-of-concept metabolomics investigation, provide a platform for identifying targets for improved drought-tolerance of the Miscanthus bioenergy crop. PMID:24324474

  6. Study on the relationship between the winter wheat thermal infrared image characteristics and physiological indicators

    NASA Astrophysics Data System (ADS)

    Chen, Zi-long; Ren, Xiang-rong; Cong, Hua; Wang, Cheng; Zhu, Da-zhou

    2014-11-01

    Arid directly affects crop growth and yield, such as reduces photosynthesis, weakens respiration rate, slows down the material transport, disorders stomatal switch, blocks the synthesis of chlorophyll, affects the cell wall and protein synthesis, etc., eventually leads to the reduction of output. How to solve this problem? This paper proposes a drought index based on thermal imaging technology. Canopy temperature distribution can reflect the growth of crops. And using thermal imaging technology can access to crop canopy temperature distribution quickly. Physiological indexes such as the changes of stomatal conductance and chlorophyll content is the important basis of crop drought resistance identification.So this paper studied the distribution of wheat canopy temperature with the change of stomatal conductance and chlorophyll content under drought conditions. The study was based on different drought resistant genotypes of winter wheat in Xinjiang with German JENOPTIK portable infrared thermal imager for canopy temperature information. The canopy leaf stomatal conductance and chlorophyll content was measured by SC-1 porosity meter and SPAD chlorophyll meter. Results prove that winter wheat canopy temperature decreases with the increase of stomatal conductance in dry conditions, which has a good linear relationship (r=-0.67). The correlation of canopy temperature and stomatal conductance of poor drought resistance(-0.93) is greater than that of good one(-0.46). There is significant difference between stomatal conductance and chlorophyll content of different drought resistance varieties(P<0.05). The variety of poor drought resistance is greater that of good one in morning-afternoon stomatal conductance change. And the chlorophyll content of the variety of good drought resistance is greater that of poor one. The conclusions above show that canopy temperature distribution has good correlation with the crop drought resistance indexes and can be used as an early indicator of drought resistance identification.This conclusion has important significance for drought resistance identification, the reasonable irrigation guidance and improving the water use efficiency.

  7. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh

    PubMed Central

    Yan, Hong; Liu, Ruiquan; Liu, Zinan; Wang, Xue; Luo, Wenbo; Sheng, Lianxi

    2015-01-01

    A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China). Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged) and three submerged conditions (5 cm, 15 cm and 25 cm water level). Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH) activity decreased but malondialdehyde (MDA) content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation. PMID:26009895

  8. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh.

    PubMed

    Yan, Hong; Liu, Ruiquan; Liu, Zinan; Wang, Xue; Luo, Wenbo; Sheng, Lianxi

    2015-01-01

    A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China). Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged) and three submerged conditions (5 cm, 15 cm and 25 cm water level). Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH) activity decreased but malondialdehyde (MDA) content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation. PMID:26009895

  9. Dynamic characteristics of gas-water interfacial plasma under water

    SciTech Connect

    Zheng, S. J.; Zhang, Y. C.; Ke, B.; Ding, F.; Tang, Z. L.; Yang, K.; Zhu, X. D.

    2012-06-15

    Gas-water interfacial plasmas under water were generated in a compact space in a tube with a sandglass-like structure, where two metal wires were employed as electrodes with an applied 35 kHz ac power source. The dynamic behaviors of voltage/current were investigated for the powered electrode with/without water cover to understand the effect of the gas-water interface. It is found that the discharge exhibits periodic pulsed currents after breakdown as the powered electrode is covered with water, whereas the electrical current reveals a damped oscillation with time with a frequency about 10{sup 6} Hz as the powered electrode is in a vapor bubble. By increasing water conductivity, a discharge current waveform transition from pulse to oscillation presents in the water covering case. These suggest that the gas-water interface has a significant influence on the discharge property.

  10. Comparative reproductive and physiological responses of northern bobwhite and scaled quail to water deprivation

    USGS Publications Warehouse

    Giuliano, W.M.; Patino, R.; Lutz, R.S.

    1998-01-01

    We compared reproductive and physiological responses of captive female northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) under control and water deprivation conditions. Scaled quail required less food and water to reproduce successfully under control conditions than northern bobwhite. Additionally, in scaled quail, serum osmolality levels and kidney mass were unaffected by water deprivation, whereas in northern bobwhite, serum osmolality levels increased and kidney mass declined. This finding indicates that scaled quail may have osmoregulatory abilities superior to those of northern bobwhite. Under control conditions, northern bobwhite gained more body mass and produced more but smaller eggs than scaled quail. Under water deprivation conditions, northern bobwhite lost more body mass but had more laying bens with a higher rate of egg production than scaled quail. Our data suggest that northern bobwhite allocated more resources to reproduction than to body maintenance, while scaled quail apparently forego reproduction in favor of body maintenance during water deprivation conditions.

  11. Comparative community physiology: nonconvergence in water relations among three semi-arid shrub communities.

    PubMed

    Jacobsen, Anna L; Pratt, R Brandon; Davis, Stephen D; Ewers, Frank W

    2008-01-01

    Plant adaptations to the environment are limited, and therefore plants in similar environments may display similar functional and physiological traits, a pattern termed functional convergence. Evidence was examined for functional convergence among 28 evergreen woody shrubs from three plant communities of the semi-arid winter rainfall region of southern California. Both leaf and water relations traits were examined, including seasonal stomatal conductance (gs), specific leaf area (SLA), leaf specific conductivity (Kl), seasonal water potential (Psi w), stem cavitation resistance (Psi 50), and xylem density. Species display community-specific suites of xylem and leaf traits consistent with different patterns of water use among communities, with coastal sage scrub species utilizing shallow pulses of water, Mojave Desert scrub species relying on deeper water reserves, and chaparral species utilizing both shallow and deep moisture reserves. Communities displayed similar degrees of water stress, with a community-level minimum Psi w (Psi wmin) of c. -4.6 Mpa, similar to other arid communities. Pooled across sites, there was a strong correlation between Psi wmin and xylem density, suggesting that these traits are broadly related and predictive of one another. This comparative community physiology approach may be useful in testing hypotheses of functional convergence across structurally similar semi-arid communities. PMID:18627498

  12. Physiologic responses to water immersion in man: A compendium of research

    NASA Technical Reports Server (NTRS)

    Kollias, J.; Vanderveer, D.; Dorchak, K. J.; Greenleaf, J. E.

    1976-01-01

    A total of 221 reports published through December 1973 in the area of physiologic responses to water immersion in man were summarized. The author's abstract or summary was used whenever possible. Otherwise, a detailed annotation was provided under the subheadings: (1) purpose, (2) procedures and methods, (3) results, and (4) conclusions. The annotations are in alphabetical order by first author; author and subject indexes are included. Additional references are provided in the selected bibliography.

  13. Mode Water Potential Vorticity Forcing Characteristics

    NASA Astrophysics Data System (ADS)

    Wienders, N.; Dewar, W. K.; Penduff, T. L.

    2008-12-01

    We are examining the different contributions to the air-sea potential vorticity (PV) forcing in the outcrops connected to the Subtropical Mode Water in the North Atlantic Ocean, for the years 2004 to 2006. The diabatic, frictional and fresh water flux contributions are considered. Their relative importance is discussed. Different model outputs have also been used in the same attempt. The global 1/4 DRAKKAR simulation, the assimilating 1 ECCO atlas, and a 1/8 idealized configuration. We verify the potential vorticity balance in an isopycnal range corresponding of the mode water, applying the impermeability theorem. The relative contribution of advection, diffusion and eddies, in the redistribution of the PV, is addressed.

  14. Physiological response of the cold-water coral Desmophyllum dianthus to thermal stress and ocean acidification

    PubMed Central

    Ferrier-Pagès, Christine; Hennige, Sebastian J.; Murray, Fiona; Rottier, Cécile; Wicks, Laura C.; Roberts, J. Murray

    2016-01-01

    Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coral Desmophyllum dianthus maintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2 conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2 levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2 significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology of D. dianthus is more sensitive to thermal than pCO2 stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species. PMID:26855864

  15. Physiological response of the cold-water coral Desmophyllum dianthus to thermal stress and ocean acidification.

    PubMed

    Gori, Andrea; Ferrier-Pagès, Christine; Hennige, Sebastian J; Murray, Fiona; Rottier, Cécile; Wicks, Laura C; Roberts, J Murray

    2016-01-01

    Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coral Desmophyllum dianthus maintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2 conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2 levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2 significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology of D. dianthus is more sensitive to thermal than pCO2 stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species. PMID:26855864

  16. Assessing physiological responses of dune forest functional groups to changing water availability: from Tropics to Mediterranean.

    NASA Astrophysics Data System (ADS)

    Antunes, Cristina; Lo Cascio, Mauro; Correia, Otília; Vieira, Simone; Cruz Diaz Barradas, Maria; Zunzunegui, Maria; Ramos, Margarida; João Pereira, Maria; Máguas, Cristina

    2014-05-01

    Alterations in water availability are important to vegetation as can produce dramatic changes in plant communities, on physiological performance or survival of plant species. Particularly, groundwater lowering and surface water diversions will affect vulnerable coastal dune forests, ecosystems particularly sensitive to groundwater limitation. Reduction of water tables can prevent the plants from having access to one of their key water sources and inevitably affect groundwater-dependent species. The additional impact of drought due to climatic change on groundwater-dependent ecosystems has become of increasing concern since it aggravates groundwater reduction impacts with consequent uncertainties about how vegetation will respond over the short and long term. Sand dune plant communities encompass a diverse number of species that differ widely in root depth, tolerance to drought and capacity to shift between seasonal varying water sources. Plant functional groups may be affected by water distribution and availability differently. The high ecological diversity of sand dune forests, characterized by sandy soils, well or poorly drained, poor in nutrients and with different levels of salinity, can occur in different climatic regions of the globe. Such is the case of Tropical, Meso-mediterranean and Mediterranean areas, where future climate change is predicted to change water availability. Analyses of the relative natural abundances of stable isotopes of carbon (13C/12C) and oxygen (18O/16O) have been used across a wide range of scales, contributing to our understanding of plant ecology and interactions. This approach can show important temporal and spatial changes in utilization of different water sources by vegetation. Accordingly, the core idea of this work is to evaluate, along a climatic gradient, the responses and capacity of different coastal plant communities to adapt to changing water availability. This large-climatic-scale study, covering Brazil, Portugal and Spain, provide an excellent experimental network to study the water dynamics and community functioning in natural ecosystems of high ecological value. To fulfill the main objective, a stable isotope approach (leaf δ13C and xylem+water sources δ18O) was used as a tool to assess physiological performance and water strategies integrated in spatio-temporal water dynamics. Plant functional groups' water use was characterized in a water changing situation (at different seasons) in a climatic gradient. We evaluated stress sensitivity of the functional groups to seasonal changes in water availability in different communities and tried to understand their water use strategy.

  17. Understanding Beta vulgaris taproot storage characteristics and relationships between biomass, sucrose, betalain and water accumulation using inbred mapping populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Population means for B. vulgaris red beet and sugar beet parental lines are quite variable in their accumulation of sucrose, betalain, water, and biomass. The variability between populations for physiological and yield characteristics is the basis for making a cross and generating an F2-derived F7 M...

  18. Highly aligned lipid membrane systems in the physiologically relevant "excess water" condition.

    PubMed Central

    Katsaras, J

    1997-01-01

    The "excess water" condition in biologically relevant systems is met when a membrane mesophase coexists with excess bulk water. Further addition of water to such a system results in no change to any of the system's physical properties (e.g., transition temperature, repeat spacing, and structural mesophases). Moreover, because biological membranes are anisotropic systems, many of their properties are best studied using aligned samples. Although model membrane systems are routinely aligned, they have traditionally been hydrated with water vapor. It is well known that membranes exposed to water vapor at 100% humidity do not imbibe the same quantity of water as a sample in contact with liquid water. As such, membranes that have been hydrated with water vapor have physical properties different from those of membranes dispersed in water. Because of this shortcoming, aligned membranes have not been utilized to their full potential. Here we present a novel and simple method of aligning model membrane systems under conditions of excess water, which will make possible, for the first time, a variety of techniques (e.g., neutron and x-ray diffraction, nuclear magnetic resonance, electron spin resonance, attenuated total reflection infrared spectroscopy, etc.) for studying such systems under physiologically relevant conditions. In addition, when dealing with samples of limited availability, the system allows for the conditions (buffer pH and ionic strength) to be altered without any effect on the sample's alignment. Images FIGURE 1 PMID:9414206

  19. [Physiological response of the distribution of non-structural carbohydrates to water stress in wheat].

    PubMed

    Su, Li-wei; Li, Sheng; Ma, Shao-ying; Wang, Ya-mei; Cao, Bao-chen

    2015-06-01

    In this paper, the spring wheat (cv. Xihan No. 2) was taken as research material to investigate the dynamic changes of the non-structural carbohydrates (NSC) in flag leaves, stems and leaf sheaths and activities of carbon-metabolizing enzymes (SSS, GBSS) in grains during wheat development process under various water stresses by water stress and re-watering treatment methods. The results indicated that various water stresses had no significant effects on the sucrose contents in flag leaves, stems, leaf sheaths and other organs of wheat. With the increase of water stress, the content of starch in flag leaves was significantly increased within 12-18 d after flowering. Water stress shortened the starch accumulation period in stems and sheaths after flowering and inhibited the transformation and distribution of starch in wheat stems. The accumulation of starch in sheath also gradually increased, which was early terminated under moderate water stress. At the beginning of the water stress, the contents of NSC in vegetative organs were listed as: flag leaves > stems > leaf sheaths. With the increase of water stresses, the NSC contents in vegetative organs were listed as: stems > flag leaves > leaf sheaths. We could conclude that the changes in main NSC (sugar, starch) distribution and carbon-metabolism enzyme activities was a kind of physiological regulation response of wheat to water stresses. PMID:26572029

  20. Response of the physiological parameters of mango fruit (transpiration, water relations and antioxidant system) to its light and temperature environment.

    PubMed

    Léchaudel, Mathieu; Lopez-Lauri, Félicie; Vidal, Véronique; Sallanon, Huguette; Joas, Jacques

    2013-04-15

    Depending on the position of the fruit in the tree, mango fruit may be exposed to high temperature and intense light conditions that may lead to metabolic and physiological disorders and affect yield and quality. The present study aimed to determine how mango fruit adapted its functioning in terms of fruit water relations, epicarp characteristics and the antioxidant defence system in peel, to environmental conditions. The effect of contrasted temperature and light conditions was evaluated under natural solar radiation and temperature by comparing well-exposed and shaded fruit at three stages of fruit development. The sun-exposed and shaded peels of the two sides of the well-exposed fruit were also compared. Depending on fruit position within the canopy and on the side of a well-exposed fruit, the temperature gradient over a day affected fruit characteristics such as transpiration, as revealed by the water potential gradient as a function of the treatments, and led to a significant decrease in water conductance for well-exposed fruits compared to fruits within the canopy. Changes in cuticle thickness according to fruit position were consistent with those of fruit water conductance. Osmotic potential was also affected by climatic environment and harvest stage. Environmental conditions that induced water stress and greater light exposure, like on the sunny side of well-exposed fruit, increased the hydrogen peroxide, malondialdehyde and total and reduced ascorbate contents, as well as SOD, APX and MDHAR activities, regardless of the maturity stage. The lowest values were measured in the peel of the shaded fruit, that of the shaded side of well-exposed fruit being intermediate. Mango fruits exposed to water-stress-induced conditions during growth adapt their functioning by reducing their transpiration. Moreover, oxidative stress was limited as a consequence of the increase in antioxidant content and enzyme activities. This adaptive response of mango fruit to its climatic environment during growth could affect postharvest behaviour and quality. PMID:23267462

  1. Coal-water slurry atomization characteristics

    SciTech Connect

    Caton, J.A.; Kihm, K.D.

    1994-04-01

    The overall objective of this work was to fully characterize the CWS fuel sprays of a medium-speed diesel engine injection system. Specifically, the spray plume penetration as a function of time was determined for a positive-displacement fuel injection system. The penetration was determined as a function of orifice diameter, coal loading, gas density in the engine, and fuel line pressure. Preliminary droplet information also was obtained. The results of this study will assist CWS engine development by providing much needed insight about the fuel spray. In addition, the results will aid the development and use of CWS engine cycle simulations which require information on the fuel spray characteristics.

  2. Lead tolerance of water hyacinth (Eichhornia crassipes Mart. - Pontederiaceae) as defined by anatomical and physiological traits.

    PubMed

    Pereira, Fabricio J; Castro, Evaristo M de; Oliveira, Cynthia de; Pires, Marinês F; Pereira, Marcio P; Ramos, Silvio J; Faquin, Valdemar

    2014-09-01

    This study aimed at verifying the lead tolerance of water hyacinth and at looking at consequent anatomical and physiological modifications. Water hyacinth plants were grown on nutrient solutions with five different lead concentrations: 0.00, 0.50, 1.00, 2.00 and 4.00 mg L-1 by 20 days. Photosynthesis, transpiration, stomatal conductance and the Ci/Ca rate were measured at the end of 15 days of experiment. At the end of the experiment, the anatomical modifications in the roots and leaves, and the activity of antioxidant system enzymes, were evaluated. Photosynthetic and Ci/Ca rates were both increased under all lead treatments. Leaf anatomy did not exhibit any evidence of toxicity effects, but showed modifications of the stomata and in the thickness of the palisade and spongy parenchyma in the presence of lead. Likewise, root anatomy did not exhibit any toxicity effects, but the xylem and phloem exhibited favorable modifications as well as increased apoplastic barriers. All antioxidant system enzymes exhibited increased activity in the leaves, and some modifications in roots, in the presence of lead. It is likely, therefore, that water hyacinth tolerance to lead is related to anatomical and physiological modifications such as increased photosynthesis and enhanced anatomical capacity for CO2 assimilation and water conductance. PMID:25211112

  3. Hand immersion in cold water alleviating physiological strain and increasing tolerance to uncompensable heat stress.

    PubMed

    Khomenok, Gennadi A; Hadid, Amir; Preiss-Bloom, Orahn; Yanovich, Ran; Erlich, Tomer; Ron-Tal, Osnat; Peled, Amir; Epstein, Yoram; Moran, Daniel S

    2008-09-01

    The current study examines the use of hand immersion in cold water to alleviate physiological strain caused by exercising in a hot climate while wearing NBC protective garments. Seventeen heat acclimated subjects wearing a semi-permeable NBC protective garment and a light bulletproof vest were exposed to a 125 min exercise-heat stress (35 degrees C, 50% RH; 5 km/h, 5% incline). The heat stress exposure routine included 5 min rest in the chamber followed by two 50:10 min work-rest cycles. During the control trial (CO), there was no intervention, whilst in the intervention condition the subjects immersed their hands and forearms in a 10 degrees C water bath (HI). The results demonstrated that hand immersion in cold water significantly reduced physiological strain. In the CO exposure during the first and second resting periods, the average rectal temperature (T (re)) practically did not decrease. With hand immersion, the mean (SD) T (re) decreased by 0.45 (0.05 degrees C) and 0.48 degrees C (0.06 degrees C) during the first and second rest periods respectively (P < 0.005). Significant decreases in skin temperature, sweat rate, heart rate, and heat storage was also noted in the HI vs. the CO trials. Tolerance time in the HI exposure were longer than in the CO exposure (only 12 subjects in the CO trial endured the entire heat exposure session, as opposed to all 17 subjects in the HI group). It is concluded that hand immersion in cold water for 10 min is an effective method for decreasing the physiological strain caused by exercising under heat stress while wearing NBC protective garments. The method is convenient, simple, and allows longer working periods in hot or contaminated areas with shorter resting periods. PMID:18478254

  4. Spectral reflectance and radiance characteristics of water pollutants

    NASA Technical Reports Server (NTRS)

    Wezernak, C. T.; Turner, R. E.; Lyzenga, D. R.

    1976-01-01

    Spectral reflectance characteristics of water pollutants and water bodies were compiled using the existing literature. Radiance calculations were performed at satellite altitude for selected illumination angles and atmospheric conditions. The work described in this report was limited to the reflective portion of the spectrum between 0.40 micrometer to 1.0 micrometer.

  5. A morpho-physiological approach differentiates bread wheat cultivars of contrasting tolerance under cyclic water stress.

    PubMed

    Jäger, Katalin; Fábián, Attila; Eitel, Gabriella; Szabó, László; Deák, Csilla; Barnabás, Beáta; Papp, István

    2014-09-01

    Leaf micromorphological traits and some physiological parameters with potential relevance to drought tolerance mechanisms were investigated in four selected winter wheat varieties. Plants were subjected to two cycles of drought treatment at anthesis. Yield components confirmed contrasting drought-sensitive and -tolerant behavior of the genotypes. Drought tolerance was associated with small flag leaf surfaces and less frequent occurrence of stomata. Substantial variation of leaf cuticular thickness was found among the cultivars. Thin cuticle coincided with drought sensitivity and correlated with a high rate of dark-adapted water loss from leaves. Unlike in Arabidopsis, thickening of the cuticular matrix in response to water deprivation did not occur. Water stress induced epicuticular wax crystal depositions preferentially on the abaxial leaf surfaces. According to microscopy and electrolyte leakage measurements from leaf tissues, membrane integrity was lost earlier or to a higher extent in sensitive than in tolerant genotypes. Cellular damage and a decline of relative water content of leaves in sensitive cultivars became distinctive during the second cycle of water deprivation. Our results indicate strong variation of traits with potential contribution to the complex phenotype of drought tolerance in wheat genotypes. The maintained membrane integrity and relative water content values during repeated water limited periods were found to correlate with drought tolerance in the selection of cultivars investigated. PMID:25014261

  6. Effects of inoculum physiological stage on the growth characteristics of Chlorella sorokiniana cultivated under different CO(2) concentrations.

    PubMed

    Mattos, Erico R; Singh, Manjinder; Cabrera, Miguel L; Das, Keshav C

    2012-10-01

    In order to maximize microalgae biomass production and reduce its overall costs, it is important to optimize inoculum conditions based on its physical and physiological characteristics. Chlorella sorokiniana cultures inoculated with inoculum at three different physiological stages (lag, exponential, and stationary) diluted to the same optical density were cultivated for 12 days under three different CO(2) concentrations (0.038, 5, or 10 % CO(2) v/v) and growth pattern and biomass production was observed. Samples inoculated with lag phase inoculum supplied with 5 % CO(2) achieved the maximum biomass production, whereas samples supplied with 0.038 % CO(2) never reached exponential growth. The better growth of samples inoculated with lag phase inoculum was attributed to its increased number of cells compared to the other two inocula. PMID:22836749

  7. Genetic variability for physiological traits under drought conditions and differential expression of water stress-associated genes in sunflower (Helianthus annuus L.).

    PubMed

    Poormohammad Kiani, S; Grieu, P; Maury, P; Hewezi, T; Gentzbittel, L; Sarrafi, A

    2007-01-01

    Genotypic variation for water status and gas exchange parameters under different water treatments (well-watered and water-stressed plants before and after rehydration) were investigated in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus L.). Afterwards, four RILs and parental lines presenting contrasting responses to dehydration and rehydration were selected to determine the differential expression of four water-stress associated genes: aquaporin, dehydrin, leafy cotyledon1-like protein and fructose-1,6 bisphosphatase. Water stress revealed a high genetic variability for water status and gas exchange parameters when compared with well-watered genotypes. Genetic gain when selected RILs were compared with the best parent was significant for most traits due to transgressive segregation. QTL mapping and graphical genotyping showed that RILs carrying different genomic regions for some QTLs presented also physiological different characteristics as well as gene expression patterns. The expression level of aquaporin genes in leaves of four RILs and their parents was down regulated by water stress and was associated with relative water content (RWC). Down-regulation was also associated with genomic regions having alleles with negative effects on plant water status. The level of dehydrin transcripts increased in leaves of all studied RILs in response to water stress. Transcript accumulations of dehydrin and leafy cotyledon1-like genes, likely involved in protective tolerance processes, were not correlated directly with plant water status or QTL effects. Down-regulation of fructose-1,6 bisphosphatase was observed under water stress. Net photosynthesis rate (P(n)) and the fructose-1,6 bisphosphatase gene expression levels were associated mainly after rehydration. This phenomenon indicates an association between physiological response to water stress and differential expression of water-stress related genes. PMID:17103138

  8. Eco-Physiological Responses of Dominant Species to Watering in a Natural Grassland Community on the Semi-Arid Loess Plateau of China

    PubMed Central

    Niu, Furong; Duan, Dongping; Chen, Ji; Xiong, Peifeng; Zhang, He; Wang, Zhi; Xu, Bingcheng

    2016-01-01

    Altered precipitation regimes significantly affect ecosystem structure and function in arid and semi-arid regions. In order to investigate effects of precipitation changes on natural grassland community in the semi-arid Loess Plateau, the current research examined eco-physiological characteristics of two co-dominant species (i.e., Bothriochloa ischaemum and Lespedeza davurica) and community composition following two watering instances (i.e., precipitation pulses, July and August, 2011, respectively) in a natural grassland community. Results showed that the photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration rapidly increased on the first to third day following watering in both species, and both months. Under watering treatments, the maximum net photosynthetic rates appeared on the second to third day after watering, which increased 30–80% in B. ischaemum and 40–50% in L. davurica compared with non-watering treatments, respectively. Leaf water use efficiency kept stable or initially decreased in both species under watering treatments. Watering in July produced more promoting effects on grass photosynthesis than in August, particularly in B. ischaemum. Community above-ground biomass at the end of the growing season increased after watering, although no significant changes in species diversity were observed. Our results indicated that timing and magnitude of watering could significantly affect plant eco-physiological processes, and there were species-specific responses in B. ischaemum and L. davurica. Pulsed watering increased community productivity, while did not significantly alter community composition after one growing season. The outcomes of this study highlight eco-physiological traits in dominant species may playing important roles in reshaping community composition under altered precipitation regimes.

  9. Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

    PubMed

    Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

    2014-06-15

    Recent studies have shown that tolerance to abiotic stress, including water stress, is improved by grafting. In a previous work, we took advantage of the natural variability of Capsicum spp. and selected accessions tolerant and sensitive to water stress as rootstocks. The behavior of commercial cultivar 'Verset' seedlings grafted onto the selected rootstocks at two levels of water stress provoked by adding 3.5 and 7% PEG (polyethylene glycol) was examined over 14 days. The objective was to identify the physiological traits responsible for the tolerance provided by the rootstock in order to determine if the tolerance is based on the maintenance of the water relations under water stress or through the activation of protective mechanisms. To achieve this goal, various physiological parameters were measured, including: water relations; proline accumulation; gas exchange; chlorophyll fluorescence; nitrate reductase activity; and antioxidant capacity. Our results indicate that the effect of water stress on the measured parameters depends on the duration and intensity of the stress level, as well as the rootstock used. Under control conditions (0% PEG) all plant combinations showed similar values for all measured parameters. In general terms, PEG provoked a strong decrease in the gas exchange parameters in the cultivar grafted onto the sensitive accessions, as also observed in the ungrafted plants. This effect was related to lower relative water content in the plants, provoked by an inefficient osmotic adjustment that was dependent on reduced proline accumulation. At the end of the experiment, chronic photoinhibition was observed in these plants. However, the plants grafted onto the tolerant rootstocks, despite the reduction in photosynthetic rate, maintained the protective capacity of the photosynthetic machinery mediated by osmotic adjustment (based on higher proline content). In addition, water stress limited uptake and further NO3(-) transfer to the leaves. Increased nitrate reductase activity in the roots was observed, mainly in plants grafted onto the sensitive rootstocks, as well as the ungrafted plants, and this was associated with the lessened flux to the leaves. This study suggests that PEG-induced water stress can be partially alleviated by using tolerant accessions as rootstocks. PMID:24877676

  10. PHYSIOLOGICAL, ANTHROPOMETRIC, STRENGTH, AND MUSCLE POWER CHARACTERISTICS CORRELATE WITH RUNNING PERFORMANCE IN YOUNG RUNNERS.

    PubMed

    Dellagrana, Rodolfo A; Guglielmo, Luiz Guilherme A; Santos, Bruno V; Hernandez, Sara G; Silva, SÉrgio G; Campos, Wagner DE

    2014-12-01

    The purpose of this study was to investigate the relationship between physiological, anthropometric, strength, and muscle power variables and a 5 km time trial (5kmT) in young runners. Twenty-three runners volunteered to participate in this study. Height, body mass (BM), body fat (BF), and fat-free mass (FFM) were measured. The subjects underwent laboratory testing to determine maximal oxygen uptake (VO2max), velocity at ventilatory threshold (VVT), running economy (RE), velocity associated with maximal oxygen uptake (vVO2max), and peak velocity (PV). Peak torque (PT), total work (TW), and power (PW) were measured by an isokinetic dynamometer at 60°·s and 240° s angular velocities. Right and left knee flexor and extensor torques were evaluated. Finally, the participants performed a 5kmT. Multiple regression and correlation analysis were used to determine the variables that significantly related to 5kmT. Strength and muscle power variables did not correlate with 5kmT. On the other hand, most physiological variables were associated with 5kmT. VVT alone explains 40% of the variance in 5kmT. The addition of the RE at speed 11.2 km.h (RE11.2) and FFM to the prediction equation allowed for 71% of the adjusted variance in 5kmT to be predicted. These results show that strength and muscle power variables are not good predictors of 5kmT; however, the physiological variables presented high prediction capacity in the 5kmT. Moreover, the anthropometric measures showed significant influence in performance prediction. PMID:25474331

  11. Growth Characteristics and Physiological Functionality of Yeasts in Pear Marc Extracts

    PubMed Central

    Jang, In-Taek; Kang, Min-Gu; Na, Kwang-Chul

    2011-01-01

    Kluyveromyces fragilis KCTC 7260 and Saccharomyces cerevisiae KCTC 7904, which both grew well in pear marc extract, were selected and their growth profiles and physiological functionalities were determined. Both of the selected yeasts established maximal growth by 20 hr of cultivation at 30℃ in pear marc extract. The cell-free extracts showed high antihypertensive angiotensin I-converting enzyme inhibitory activity of 68.9% and 52.1%, respectively. The extracts also displayed 9.2 U/mL and 12.0 U/mL of protease activity, respectively. PMID:22783099

  12. Short communication: Characteristics of student success in an undergraduate physiology and anatomy course.

    PubMed

    Gwazdauskas, F C; McGilliard, M L; Corl, B A

    2014-10-01

    Several factors affect the success of students in college classes. The objective of this research was to determine what factors affect success of undergraduate students in an anatomy and physiology class. Data were collected from 602 students enrolled in the Agriculture and Life Sciences (ALS) 2304 Animal Physiology and Anatomy course from 2005 through 2012. The data set included 476 females (79.1%) and 126 males (20.9%). Time to complete exams was recorded for each student. For statistical analyses, students' majors were animal and poultry sciences (APSC), agricultural sciences, biochemistry, biological sciences, dairy science, and "other," which combined all other majors. All analyses were completed using the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC). Gender, major, matriculation year, major by year interaction, gender by year interaction, and time to complete the exam affected final course grade. The significant gender effect was manifested in the final grade percentage of 75.9 ± 0.4 for female students compared with 72.3 ± 0.6 for male students. Junior males had final course grades comparable with those of females, but sophomore and senior males had lower final course grades than other combinations. Biology majors had a final grade of 82.4 ± 0.6 and this grade was greater than all other majors. Students classified as "other" had a final score of 74.4 ± 0.8, which was greater than agricultural science majors (69.5 ± 0.9). The APSC grade (72.6 ± 0.5) was higher than the agricultural science majors. Junior students had significantly greater final grades (76.1 ± 0.5) than sophomores (73.3 ± 0.6) and seniors (72.9 ± 0.9). All biology students had greater final grades than all other majors, but biochemistry juniors had greater final course grades than APSC, agricultural science, and dairy science juniors. "Other" seniors had greater final course grades than agricultural science seniors. The regression for time to complete the exam was curvilinear and suggests that highest exam scores were at about 90-min completion time. It may be that some male students need better preparation for anatomy and physiology and their educational preparation should mimic that of female students more in terms of advance-placement biology in high school. These results suggest that biology majors might be better prepared for animal anatomy and physiology than other students. PMID:25087028

  13. [Impacts of algal blooms accumulation on physiological ecology of water hyacinth].

    PubMed

    Wu, Ting-ting; Liu, Guo-feng; Han, Shi-qun; Zhou, Qing; Tang, Wan-ying

    2015-01-01

    Blue-green algae bloom will consume plenty of dissolved oxygen in water, which affects the growth of aquatic plants. The effects of water hyacinth growth and physiological response changes under 25 degrees C, 5 different concentrations of cyanobacteria gathered were studied and which would provide a theoretical basis to mitigate adverse impacts and improve water purification effect. The results showed that water quality indexes including dissolved oxygen (DO), pH dropped in algae density below 60 g x L(-1), with the increase of algae density. And the level of oxidation-reduction potential dropped to about 100 mV. The removal rates of TN, TP and COD were 58%-78%, 43%-68% and 59%-73%, leaf soluble protein, soluble sugar, MDA contents increased, respectively; and the MDA content became higher with the increase of algae density. It indicated that the water hyacinth could adapt to the adversity condition as algae density less than 60 g x L(-1). While algae density above 60 g x L(-1), water quality indexes significantly decreased, respectively and the water was in hypoxia or anoxia conditions. Plant leaves soluble sugar contents had a change trend of low-high-low. It indicated that the removal rates of TN, TP decreased with the increase of algae density and water hyacinth had irreversible stress. Plant root length, total length, fresh weight in different treatments, increased compared with the beginning of the experiment, the increase of root length, total length and fresh weight were 0.29-2.44 times, 0.41-0.76 times and 0.9-1.43 times. The increase of root length, total length decreased with the increase of algae density. According to the results, the cyanobacteria should avoid of excessive accumulation as using the floating plant to purify the water. PMID:25898654

  14. A Pig Model of the Preterm Neonate: Anthropometric and Physiological Characteristics

    PubMed Central

    Eiby, Yvonne A.; Wright, Layne L.; Kalanjati, Viskasari P.; Miller, Stephanie M.; Bjorkman, Stella T.; Keates, Helen L.; Lumbers, Eugenie R.; Colditz, Paul B.; Lingwood, Barbara E.

    2013-01-01

    Background Large animal models are an essential tool in the development of rationally-based new clinical therapies for preterm infants. We provide a description of the newborn pig as a model of the preterm neonate in terms of growth parameters, physiology and the requirement for intensive care over a range of gestational ages. Methods Twenty-nine litters of piglets (n = 298) were delivered by caesarean section at six timepoints during gestation from 91d to 113d (term = 115d). Two groups, at 91 and 97d gestation, also received maternal glucocorticoid treatment. At four of these timepoints, piglets (n = 79) were ventilated, sedated and monitored using standard neonatal intensive care techniques for up to 8 h in various experimental protocols. Results Body weight increased from mean 697 g (SD 193) at 91d gestation to 1331 g (SD 368) at 113d gestation. Piglets delivered at 97d gestation were able to be resuscitated and kept alive for at least 8 h on respiratory support after surfactant administration. Maternal glucocorticoid treatment 48 h and 24 h hours prior to delivery reduced the requirement for ventilator support and improved cardiovascular stability. Conclusion The pig provides a relevant model for the study of human preterm physiology and for investigation of novel therapies to improve outcomes. PMID:23874755

  15. The effect of lichen-dominated biological soil crusts on growth and physiological characteristics of three plant species in a temperate desert of northwest China.

    PubMed

    Zhuang, W W; Serpe, M; Zhang, Y M

    2015-11-01

    Biocrusts (biological soil crusts) cover open spaces between vascular plants in most arid and semi-arid areas. Information on effects of biocrusts on seedling growth is controversial, and there is little information on their effects on plant growth and physiology. We examined impacts of biocrusts on growth and physiological characteristics of three habitat-typical plants, Erodium oxyrhynchum, Alyssum linifolium and Hyalea pulchella, growing in the Gurbantunggut Desert, northwest China. The influence of biocrusts on plant biomass, leaf area, leaf relative water content, photosynthesis, maximum quantum efficiency of PSII (F(v)/F(m)), chlorophyll, osmotic solutes (soluble sugars, protein, proline) and antioxidant enzymes (superoxide dismutase, catalase, peroxidase) was investigated on sites with or without biocrust cover. Biomass, leaf area, leaf water content, photosynthesis, F(v)/F(m) and chlorophyll content in crusted soils were higher than in uncrusted soils during early growth and lower later in the growth period. Soluble sugars, proline and antioxidant enzyme activity were always higher in crusted than in uncrusted soils, while soluble protein content was always lower. These findings indicate that biocrusts have different effects on these three ephemeral species during growth in this desert, primarily via effects on soil moisture, and possibly on soil nutrients. The influence of biocrusts changes during plant development: in early plant growth, biocrusts had either positive or no effect on growth and physiological parameters. However, biocrusts tended to negatively influence plants during later growth. Our results provide insights to explain why previous studies have found different effects of biocrusts on vascular plant growth. PMID:26084731

  16. Impact of stocking density on broiler growth performance, meat characteristics, behavioural components and indicators of physiological and oxidative stress.

    PubMed

    Simitzis, P E; Kalogeraki, E; Goliomytis, M; Charismiadou, M A; Triantaphyllopoulos, K; Ayoutanti, A; Niforou, K; Hager-Theodorides, A L; Deligeorgis, S G

    2012-01-01

    1. The study was designed to assess the impact of stocking density (6 and 13 birds/m equivalent to 126 or 272?kg/m, respectively) on growth performance, meat quality, behaviour, and indicators of physiological and oxidative stress as measures of bird welfare. 2. The higher stocking density negatively affected final body weight and feed intake but not cumulative feed conversion rate. Muscle colour traits, pH??, cooking loss and shear values were not affected. Birds reared at the lower density showed higher intramuscular fat, liver weight, liver NADP-isocitrate and NADP-malate dehydrogenase activity. 3. Higher stocking density was associated with decreased locomotor activity and increased physiological (H:L ratio and bursa weight) and oxidative (glutathione concentrations and reduced:oxidised glutathione ratios) stress indicators. 4. The results show that stocking density did not significantly affect broiler meat quality characteristics but higher density decreased growth performance, increased physiological and oxidative stress levels and decreased locomotor activity. PMID:23398415

  17. Twenty-Four-Hour Urine Osmolality as a Physiological Index of Adequate Water Intake

    PubMed Central

    Perrier, Erica T.; Buendia-Jimenez, Inmaculada; Vecchio, Mariacristina; Armstrong, Lawrence E.; Tack, Ivan; Klein, Alexis

    2015-01-01

    While associations exist between water, hydration, and disease risk, research quantifying the dose-response effect of water on health is limited. Thus, the water intake necessary to maintain optimal hydration from a physiological and health standpoint remains unclear. The aim of this analysis was to derive a 24 h urine osmolality (UOsm) threshold that would provide an index of “optimal hydration,” sufficient to compensate water losses and also be biologically significant relative to the risk of disease. Ninety-five adults (31.5 ± 4.3 years, 23.2 ± 2.7 kg·m−2) collected 24 h urine, provided morning blood samples, and completed food and fluid intake diaries over 3 consecutive weekdays. A UOsm threshold was derived using 3 approaches, taking into account European dietary reference values for water; total fluid intake, and urine volumes associated with reduced risk for lithiasis and chronic kidney disease and plasma vasopressin concentration. The aggregate of these approaches suggest that a 24 h urine osmolality ≤500 mOsm·kg−1 may be a simple indicator of optimal hydration, representing a total daily fluid intake adequate to compensate for daily losses, ensure urinary output sufficient to reduce the risk of urolithiasis and renal function decline, and avoid elevated plasma vasopressin concentrations mediating the increased antidiuretic effort. PMID:25866433

  18. Physiological and morphological adaptations in relation to water use efficiency in Mediterranean accessions of Solanum lycopersicum.

    PubMed

    Galmés, Jeroni; Conesa, Miquel Àngel; Ochogavía, Joan Manuel; Perdomo, Juan Alejandro; Francis, David M; Ribas-Carbó, Miquel; Savé, Robert; Flexas, Jaume; Medrano, Hipólito; Cifre, Josep

    2011-02-01

    The physiological traits underlying the apparent drought resistance of 'Tomàtiga de Ramellet' (TR) cultivars, a population of Mediterranean tomato cultivars with delayed fruit deterioration (DFD) phenotype and typically grown under non-irrigation conditions, are evaluated. Eight different tomato accessions were selected and included six TR accessions, one Mediterranean non-TR accession (NTR(M)) and a processing cultivar (NTR(O)). Among the TR accessions two leaf morphology types, normal divided leaves and potato-leaf, were selected. Plants were field grown under well-watered (WW) and water-stressed (WS) treatments, with 30 and 10% of soil water capacity, respectively. Accessions were clustered according to the leaf type and TR phenotype under WW and WS, respectively. Correlation among parameters under the different water treatments suggested that potential improvements in the intrinsic water-use efficiency (A(N)/g(s)) are possible without negative impacts on yield. Under WS TR accessions displayed higher A(N)/g(s), which was not due to differences in Rubisco-related parameters, but correlated with the ratio between the leaf mesophyll and stomatal conductances (g(m)/g(s)). The results confirm the existence of differential traits in the response to drought stress in Mediterranean accessions of tomato, and demonstrate that increases in the g(m)/g(s) ratio would allow improvements in A(N)/g(s) in horticultural crops. PMID:20955222

  19. Physiological effects of sublethal levels of acid water on three species of fishes

    SciTech Connect

    Pegg, W.J.

    1984-01-01

    Static toxicity tests revealed the need to assess the effect of acid mine water using some procedure that would gradually increase the concentration of acidity over a period of time. A relatively long-term (2-5 days) experiment involving the devlopment of a sublethal acid treatment gradient was chosen as potentially being the most representative of natural environments which are periodically subjected to changing inputs from coal mine drainage. Since respiratory change is an indication of physiological stress, the measurement of oxygen consumption rate was chosen as the major variable representing the effect of acid waters on fishes. Bluegill sunfish Lepomes macrochirus Rafinesque, pumpkinseed sunfish, Lepomis gibbosus (Linnaeus), and brown bullhead, Ictalurus nebulosus (LeSueur) were collected from the Monongahela River and backwater areas in the region of Morgantown, West Virginia. The sublethal acid water treatments decreased the oxygen consumption rates for brown bullhead and bluegill sunfish, while increasing the oxygen consumption rate for pumpkinseed sunfish. Further, the rhythms of the oxygen consumption rates were generally modified in both frequency and amplitude as a result of exposure to acid water. Acid water treatments also caused negative phase shifts in oxygen consumption rate for brown bullhead sand bluegill sunfish, while positive phase shifts occurred for pumpkinseed sunfish.

  20. Pros and Cons of Using Water Immersion to Simulate Physiological Responses to Microgravity

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Tomko, David L. (Technical Monitor)

    1995-01-01

    Head-out water immersion (HOI) has been employed as a remedial treatment for various ills and ailments for many millennia, and total body immersion even longer as protective encapsulation for the mammalian fetus. Two discrete differences between stimuli induced by true microgravity (10(exp -4) g) and HOI are readily apparent. External water pressure on the skin and accompanying negative pressure breathing cause blood to shift headward. Secondly, the gravitational force is ever present during immersion and microgravity, but its effect is essentially neutralized during Earth orbital flight. Thus, the physiological responses to immersion should not be expected to match those during microgravity. Immersion has been used mainly to study and understand kidney function and associated cardiovascular responses for control of body fluid volume and osmotic content, with some application to and simulation of microgravity responses. There is a plethora of data from human HOI studies, but relatively few controlled data from microgravity studies. In general, it appears that physiological responses occur more quickly with water immersion than in microgravity, but this may be due to less rigorous control (voluntary and involuntary) of the preflight state of crew members. The central venous pressure-vasopressin (Gauer-Henry) reflex control for fluid balance may not be of prime importance in microgravity. Gross functions such as reduced body weight and water, level of hypovolemia, decreased isokinetic strength, and lower nitrogen balance found during immersion are qualitatively similar in microgravity, but the mechanisms controlling these and other functions are, for the most part, unclear. Only acquisition of data from well-controlled microgravity experiments will resolve this discrepancy.

  1. Physiological characteristics of Thiomicrospira sp. strain L-12 isolated from deep-sea hydrothermal vents

    SciTech Connect

    Ruby, E.G.; Jannasch, H.W.

    1982-01-01

    Growth of the obligately chemolithotrophic Thiomicrospira sp. strain L-12, isolated from a hydrothermal vent at a depth of 2,550 m in the Galapagos Rift region, was optimal at pH 8 and required 200 mM Na/sup +/ and divalent ions (Ca/sup 2 +/ and Mg/sup 2 +/). The organism was microaerophilic and tolerated 300 ..mu..M sulfide without a decrease in the rate of CO/sub 2/ incorporation. Growth and CO/sub 2/ incorporation occurred within the temperature range of 10 to 35/sup 0/C, with both optimal at 25/sup 0/C. At the in situ pressure of 250 atm, the rate of CO/sub 2/ incorporation was reduced by 25% relative to that measured at 1 atm; it was entirely suppressed at 500 atm. The results of this physiological characterization suggest that Thiomicrospira sp. strain L-12 can be an active autotroph in the hydrothermal environment.

  2. Novel mineral-oxidizing bacteria from Montserrat (W.I.): physiological and phylogenetic characteristics

    SciTech Connect

    A. Yahya; F. F. Roberto; D. B. Johnson

    1999-06-01

    Four mesophilic acidophilic bacteria isolated from the Caribbean island of Montserrat have been studied to establish their taxonomic relationship to other metal-metabolizing bacteria and to analyze their potential role in mineral processing. Two of the isolates have some physiological and morphological traits in common with Thiobacillus ferrooxidans (Gram negative, iron-oxidizing mesophilic rods) but differed from T. ferrooxidans in displaying chemolitho-heterotrophic growth in ferrous iron/yeast extract medium and greater sensitivity to some metals. Isolates RIV-14 and L-15 were, in contrast, Gram positive, spore-forming rods that displayed considerable metabolic flexibility, and resembled moderately thermophilic Sulfobacillus spp. All the Montserrat isolates were able to oxidize pyrite in pure culture.

  3. [Effects of Ni2+ on physiological characteristics and submicroscopic structure of Salvinia natans leaves].

    PubMed

    Ji, Wang-dong; Shi, Guo-xin; Xu, Qin-song; Xu, Ye; Yang, Hai-yan; Du, Kai-he

    2008-08-01

    Influence of 0, 5, 10, 15, 20 mg/L Ni2+ on growth, mineral nutrition, chlorophyll, carotenoid, soluble protein, soluble sugar, superoxide (O2*-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents as well as the activities of superoxide dismutase (SOD), guaiacolperoxidase (POD), and catalase (CAT) were studied in the leaves of Salvinia natans plants on 10 days after treatment. With the increase of the Ni2+ concentrations, exposure of the plants revealed that, (1) the addition of Ni2+ affected the absorption of mineral nutrients, it mainly increased the absorption of Ca2+, Na+, Zn2+, Fe3+ and Mg2+, while reduced that of Mn2+, Mo2+, P and K+. (2) The content of chlorophyll, carotenoid, soluble protein and soluble sugar content as well as activities of SOD and CAT decreased gradually. That of O2*-, H2O2 and MDA content as well as POD activity increased, 383%, 168%, 207%, 131% of these controls, respectively. (3) In the leaves of Ni2+ -treated fronds, the polypeptide with apparent molecular weights 94000, was became visible in SDS-PAGE, and the nature of it remains to be determined. The amount and intensity of polypeptide band increased gradually with augment of Ni2+ was also observed, the polypeptide with apparent molecular weight 35,000 increased significantly in fronds. (4) Transmission electron microscope observation indicated that Ni2+ also imposed injury action on submicroscopic structure of leaf cells, disaggregation of nucleolus, agglutination and disappearance of chromatin of nucleus, disruption of nuclear membrane, swelling of thylakoids and breakage of chloroplast envelope, decreasing of cristae quantity and vacuolization of mitochondria. The conclusion could be reached that the plant death was resulted from destruction under structure foundation of physiological function, unbalance of ion equilibrium and disorder of physiological metabolism. PMID:18839591

  4. Effects of Age and Military Service on Strength and Physiological Characteristics of U.S. Army Soldiers.

    PubMed

    Abt, John P; Perlsweig, Katherine; Nagai, Takashi; Sell, Timothy C; Wirt, Michael D; Lephart, Scott M

    2016-02-01

    Soldiers must maintain tactical performance capabilities over the course of their career. Loss in physical readiness may be a function of age and the operational demands associated with increasing years of service. The purpose of this study was to assess strength and physiological characteristics in different cohorts of U.S. Army Soldiers based on years of service and age. A total of 253 Soldiers (age: 28.1 ± 6.8 years; height: 1.76 ± 0.11 m; mass: 84.1 ± 12.2 kg) participated. Individual subject cohorts were created based on years of service (1-5 years, 6-10 years, 11-15 years) and age (20-24 years, 25-29 years, 30-34 years, 35-39 years, 40-44 years). Testing included shoulder, knee, ankle, and torso strength, aerobic capacity/lactate threshold, anaerobic power/capacity, and body composition/total mass. Those with 11 to 15 years of service and between ages 30 and 34 had a higher percentage of body fat, and lower aerobic capacity and lactate threshold than younger Soldiers with fewer years of service. Physical training interventions should focus on maintenance of physiological characteristics to offset the loss of readiness at the similar time point of 11 to 15 years of service and 30 to 34 years of age. PMID:26837087

  5. Relation of Spectral and Physiological Properties to Leaf Structural Characteristics of Arsenic Treated Rice Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arsenic (As) is a widely spread soil contaminant which can cause toxicity in plants. Although many studies have investigated the spectral characteristics of affected plants, the extent to which different toxicities may result in correspondingly different spectral signatures has received little atte...

  6. Patterns of water use and the tissue water relations in the dioecious shrub, Salix arctica: the physiological basis for habitat partitioning between the sexes.

    PubMed

    Dawson, T E; Bliss, L C

    1989-05-01

    Within the high arctic of Canada, Salix arctica, a dioecious, dwarf willow exhibits significant spatial segregation of the sexes. The overall sex ratio is female-biased and female plants are especially common in wet, higher nutrient, but lower soil temperature habitats. In contrast, male plants predominate in more xeric and lower nutrient habitats with higher soil temperatures that can be drought prone. Associated with the sex-specific habitat differences were differences in the seasonal and diurnal patterns of water use as measured by stomatal conductance to water vapor and the bulk tissue water relations of each gender. Within the wet habitats, female plants maintained higher rates of stomatal conductance (g) than males when soil and root temperatures were low (<4° C). In contrast, within the xeric habitats, male plants maintained higher g and had lower leaf water potentials Ψleaf at low soil water potentials and a high leaf-to-air vapor pressure gradient (Δw) when compared to females. Female plants had more positive carbon isotope ratios than males indicating a lower internal leaf carbon dioxide concentration and possibly higher water use efficiency relative to males. Tissue osmotic and elastic properties also differed between the sexes. Male plants demonstrated lower tissue osmotic potentials near full tissue hydration and at the turgor loss point and a lower bulk tissue elastic modulus (higher tissue elasticity) than female plants. Males also demonstrated a greater ability to osmotically adjust on a diurnal basis than females. These properties allowed male plants to maintain higher tissue turgor pressures at lower tissue water contents and Ψsoil over the course of the day. The sex-specific distributional and ecophysiological characteristics were also correlated with greater total plant growth and higher fecundity of females in wet habitats, and males in xeric habitats respectively. The intersexual differences in physiology persisted in all habitats. These results and those obtained from growth chamber studies suggest that sex-specific differences have an underlying genetic basis. From these data we conjecture that selection maintaining the intersexual differences may be related to different costs associated with reproduction that can be most easily met through physiological specialization and spatial segregation of the sexes among habitats of differing conditions. PMID:23921398

  7. Morphological and Physiological Characteristics of Laminar Cells in the Central Nucleus of the Inferior Colliculus

    PubMed Central

    Wallace, Mark N.; Shackleton, Trevor M.; Palmer, Alan R.

    2012-01-01

    The central nucleus of the inferior colliculus (IC) is organized into a series of fibro-dendritic laminae, orthogonal to the tonotopic progression. Many neurons have their dendrites confined to one lamina while others have dendrites that cross over a number of laminae. Here, we have used juxtacellular labeling in urethane anesthetized guinea pigs to visualize the cells with biocytin and have analyzed their response properties, in order to try and link their structure and function. Out of a sample of 38 filled cells, 15 had dendrites confined within the fibro-dendritic laminae and in 13 we were also able to reconstruct their local axonal tree. Based on dendritic morphology they were subdivided into flat or less flat; small, medium, or large; elongated or disk-shaped cells. Two of the elongated cells had many dendritic spines while the other cells had few or none. Twelve of the cells had their local axonal tree restricted to the same lamina as their dendrites while one cell had its dendrites in a separate lamina from the axon. The axonal plexus was more extensive (width 0.7–1.4 mm) within the lamina than the dendrites (width generally 0.07–0.53 mm). The intrinsic axons were largely confined to a single lamina within the central nucleus, but at least half the cells also had output axons with two heading for the commissure and five heading into the brachium. We were able to identify similarities in the physiological response profiles of small groups of our filled cells but none appeared to represent a homogeneous morphological cell type. The only common feature of our sample was one of exclusion in that the onset response, a response commonly recorded from IC cells, was never seen in laminar cells, but was in cells with a stellate morphology. Thus cells with laminar dendrites have a wide variety of physiological responses and morphological subtypes, but over 90% have an extensive local axonal tree within their local lamina. PMID:22933991

  8. Structural characteristics of thermosensitive chitosan glutamate hydrogels in variety of physiological environments

    NASA Astrophysics Data System (ADS)

    Modrzejewska, Z.; Nawrotek, K.; Maniukiewicz, W.; Douglas, T.

    2014-09-01

    In this paper the properties of thermosensitive chitosan hydrogels prepared with the use of chitosan glutamate and β-glycerophosphate are presented. The study is focused on the determination of changes in the hydrogel structure in different environments: during conditioning in water and buffer at pH 7 and pH 2 respectively. The structure of gels was observed under the Scanning Electron Microscopy (SEM) and was investigated by infrared (IR) spectroscopy. The crystallinity of gel structure was determined by X-ray diffraction analysis (XRD). On the basis of structural changes during the conditioning in water a mechanism of their formation was proposed.

  9. Terms and Characteristics of Homogeneous Ignition of Coal-Water Particles Coated with a Water Film

    NASA Astrophysics Data System (ADS)

    Syrodoy, S. V.; Gutareva, N. Y.; Taburchinov, R. I.; Bugaeva, K. A.

    2016-02-01

    The problem of coal-water fuel ignition of particles in a high-temperature heating has been solved numericallyin the framework of a two-layer model of "coal-water". The basic characteristics of the integrated ignition has been shown. The influence of the vaporization process of the water film on the ignition conditions has been shown.

  10. Physiological responses of water-polo players under different tactical strategie.

    PubMed

    Botonis, Petros G; Toubekis, Argyris G; Platanou, Theodoros I

    2015-03-01

    The aim of this study was to investigate the effect of defense tactical strategy on physiological responses characterizing playing intensity in water-polo game. In the first part of the study, fourteen players were assigned to defending (n = 7) and offending (n = 7) groups and participated in nine 4-min plays applying three different defending systems: press, static-zone and zone-press, in front of the defense court of one goalpost. In the second part, 18 players participated in nine different real full court water-polo games consisting of 3X15min of live-time playing periods. Both in defense court plays and real games, the three defense systems were played in a counterbalanced order and heart rate (HR) was continuously recorded. Additionally, in defense court plays, blood lactate concentration (La) was measured at the end of each 4-min period. Mean HR within defense court plays was higher in press (153 10 beats(.)min(-1)) than in static-zone (140 11 beats(.)min(-1)) and zone-press (143 16 beats(.)min(-1), p < 0.01). Furthermore, shorter amount of playing time was spent with HR ?85% of HR peak in press (46.3 22.8%) than in static-zone (81.8 20.5%) and zone-press (75.7 32.0%, p < 0.01). Likewise, mean La was higher in press (6.52.9 mmol(.)l(-1)) than in static-zone (4.7 2.5 mmol(.)l(-1)) and zone-press (4.6 1.8 mmol(.)l(-1), p < 0.01). In real games, however, mean HR was similar between tactical strategies (p > 0.05). Defenders and offenders showed similar HR and La responses across the tactical modes. In conclusion, defense tactical strategies affect physiological responses within a part of the game but do not affect the overall playing intensity of a real water-polo game. Tactical strategies similarly affect offenders and defenders. Key pointsWithin defence court plays, exercise intensity in press is higher than zone-press and static zone tactical systems.In real game the physiological response is similar between defense systems.Tactical strategies similarly affect offenders and defenders. PMID:25729294

  11. Stratospheric water inferred from Lagrangian Cold Point characteristics

    NASA Astrophysics Data System (ADS)

    Ploeger, F.; Konopka, P.; Schiller, C.

    2009-04-01

    Total water was recently measured onboard the Geophysica high-altitude aircraft using the Jülich fluorescence hygrometer FISH during the three tropical campaigns TroCCiNOx (January-February 2005), SCOUT-O3 (November-December 2005) and AMMA (August 2006) over Southern Brazil, Northern Australia and West Africa. Trajectories are initialized at the flight locations, calculated backwards for ten days and the Lagrangian Cold Point (LCP) characteristics determined along the paths. To test whether stratospheric water values can be deduced from the temperature history of air, minimum saturation water vapor is derived from the LCP-temperature and compared to the measurements.

  12. Effects of de-icing salt on ground water characteristics.

    PubMed

    O'Brien, J E; Majewski, J C

    1975-01-01

    The effect of "road salt" on the characteristics of Massachusetts drinking water supplies has been significant and cumulative rather than transient or seasonal. De-icing salt is essentially all sodium chloride. Calcium chloride accounted for only three percent of the total salt used. However, hardness content, as well as sodium ion concentration, has increased greatly in ground waters in the past decade. The changing composition of our water supplies has agricultural, economic, and public health implications. This study attempts to quantify the stoichiometry of these changes in concentration, which are in part due to an ion-exchange mechanism in the soil. PMID:238830

  13. Effects of Maternally-Transferred Methylmercury on Stress Physiology in Northern Water Snake (Nerodia sipedon) Neonates.

    PubMed

    Cusaac, J Patrick W; Kremer, Victoria; Wright, Raymond; Henry, Cassandra; Otter, Ryan R; Bailey, Frank C

    2016-06-01

    Biomagnification of methylmercury in aquatic systems can cause elevated tissue mercury (Hg) and physiological stress in top predators. Mercury is known to affect stress hormone levels in mammals, birds and fish. In this study, the effects of maternally-transferred methylmercury on the stress physiology of Northern Water Snake (Nerodia sipedon) neonates were tested. Gravid females were dosed via force-fed capsules during late gestation with 0, 0.01, or 10 µg methylmercury per gram of body mass. Plasma corticosterone levels and leukocyte differentials were analyzed in baseline and confinement-stressed neonates from all dose levels. Neither Hg nor confinement stress had a significant effect on leukocyte differentials nor was Hg related to corticosterone levels. However, stress group neonates showed lower heterophil/lymphocyte ratios and this study was the first to show that neonate N. sipedon can upregulate CORT in response to stress. These results indicate that N. sipedon may be somewhat tolerant to Hg contamination. PMID:26886428

  14. Gene expression and physiological responses to salinity and water stress of contrasting durum wheat genotypes.

    PubMed

    Yousfi, Salima; Márquez, Antonio J; Betti, Marco; Araus, José Luis; Serret, Maria Dolores

    2016-01-01

    Elucidating the relationships between gene expression and the physiological mechanisms remains a bottleneck in breeding for resistance to salinity and drought. This study related the expression of key target genes with the physiological performance of durum wheat under different combinations of salinity and irrigation. The candidate genes assayed included two encoding for the DREB (dehydration responsive element binding) transcription factors TaDREB1A and TaDREB2B, another two for the cytosolic and plastidic glutamine synthetase (TaGS1 and TaGS2), and one for the specific Na(+) /H(+) vacuolar antiporter (TaNHX1). Expression of these genes was related to growth and different trait indicators of nitrogen metabolism (nitrogen content, stable nitrogen isotope composition, and glutamine synthetase and nitrate reductase activities), photosynthetic carbon metabolism (stable carbon isotope composition and different gas exchange traits) and ion accumulation. Significant interaction between genotype and growing conditions occurred for growth, nitrogen content, and the expression of most genes. In general terms, higher expression of TaGS1, TaGS2, TaDREB2B, and to a lesser extent of TaNHX1 were associated with a better genotypic performance in growth, nitrogen, and carbon photosynthetic metabolism under salinity and water stress. However, TaDREB1A was increased in expression under stress compared with control conditions, with tolerant genotypes exhibiting lower expression than susceptible ones. PMID:25869057

  15. Differential responses of grapevine rootstocks to water stress are associated with adjustments in fine root hydraulic physiology and suberization.

    PubMed

    Barrios-Masias, F H; Knipfer, T; McElrone, A J

    2015-09-01

    Water deficits are known to alter fine root structure and function, but little is known about how these responses contribute to differences in drought resistance across grapevine rootstocks. The ways in which water deficit affects root anatomical and physiological characteristics were studied in two grapevine rootstocks considered as low-medium (101-14Mgt) and highly (110R) drought resistant. Rootstocks were grown under prolonged and repeated drying cycles or frequent watering ('dry' and 'wet' treatments, respectively), and the following parameters were evaluated: root osmotic and hydrostatic hydraulic conductivity (Lp os and Lp hyd, respectively), suberization, steady-state root pressure (P rs), sap exudation rates, sap osmotic potential, and exosmotic relaxation curves. For both rootstocks, the 'dry' treatment reduced fine root Lp, elicited earlier root suberization and higher sap osmotic potential, and generated greater P rs after rewatering, but the rootstocks responded differently under these conditions. Lp os, Lp hyd, and sap exudation rates were significantly higher in 110R than in 101-14Mgt, regardless of moisture treatment. Under 'dry' conditions, 110R maintained a similar Lp os and decreased the Lp hyd by 36% compared with 'wet' conditions, while both parameters were decreased by at least 50% for 101-14Mgt under 'dry' conditions. Interestingly, build-up of P rs in 110R was 34% lower on average than in 101-14Mgt, suggesting differences in the development of suberized apoplastic barriers between the rootstocks as visualized by analysis of suberization from fluorescence microscopy. Consistent with this pattern, 110R exhibited the greatest exosmotic Lp os (i.e. Lp os of water flowing from roots to the soil) as determined from relaxation curves under wet conditions, where backflow may have limited its capacity to generate positive xylem pressure. The traits studied here can be used in combination to provide new insights needed for screening drought resistance across grapevine rootstocks. PMID:26160580

  16. Aerodynamic Characteristics of Water Rocket and Stabilization of Flight Trajectory

    NASA Astrophysics Data System (ADS)

    Watanabe, Rikio; Tomita, Nobuyuki; Takemae, Toshiaki

    The aerodynamic characteristics of water rockets are analyzed experimentally by wind tunnel testing. Aerodynamic devices such as vortex generators and dimples are tested and their effectiveness to the flight performance of water rocket is discussed. Attaching vortex generators suppresses the unsteady body fluttering. Dimpling the nose reduces the drag coefficient in high angles of attack. Robust design approach is applied to water rocket design for flight stability and optimum water rocket configuration is determined. Semi-sphere nose is found to be effective for flight stability and it is desirable for the safety of landing point. Stiffed fin attachment is required for fins to work properly as aerodynamic device and it enhances the flight stability of water rockets.

  17. A STUDY ABOUT HYDRAULIC CHARACTERISTICS OF UNIONOIDA UNDER FLOWING WATER

    NASA Astrophysics Data System (ADS)

    Hayashi, Hironori; Shimatani, Yukihiro; Kozaki, Ken; Ikematsu, Shinya; Tsujimoto, Yotaku

    Fresh water mussels (order Unionoida) have one of the important biological roles for river ecosystems. However, abundance and habitat range of Unionoida are drastically decreasing, because of environmental change based on many artificial river works, such as over riverbed excavation and loss of floodplain habitat. There are three Unionoida species in the Matsuura river, and one lentic species (Anodouta lauta) has been dominantly decreased over the past 50 years. As they have low mobility, Unionoida are strongly affected by physical environmental change of river. In this study, we focused attention on the hydraulic characteristics of Unionoida in flowing water condition, and conducted some hydraulic experiment to three Unionoida species. The result indicated that lentic species (Anodonta lauta) was easily affected by flowing water than lotic species (Unio douglasiae nipponensis, Lanceolaria grayana). And the result suggested that hydraulic characteristic of Unionoida was one of the reason that caused a decrement of lentic Unionoida species in the Matsuura river.

  18. Physiology of Fluid and Electrolyte Responses During Inactivity: Water Immersion and Bed Rest

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.

    1984-01-01

    This manuscript emphasizes the physiology of fluid-electrolyte-hormonal responses during the prolonged inactivity of bed rest and water immersion. An understanding of the total mechanism of adaptation (deconditioning) should provide more insight into the conditioning process. Findings that need to be confirmed during bed rest and immersion are: (1) the volume and tissues of origin of fluid shifted to the thorax and head; (2) interstitial fluid pressure changes in muscle and subcutaneous tissue, particularly during immersion; and (3) the composition of the incoming presumably interstitial fluid that contributes to the early hypervolemia. Better resolution of the time course and source of the diuretic fluid is needed. Important data will be forthcoming when hypotheses are tested involving the probable action of the emerging diuretic and natriuretic hormones, between themselves and among vasopressin and aldosterone, on diuresis and blood pressure control.

  19. [Meibomian glands. Part II: physiology, characteristics, distribution and function of meibomian oil].

    PubMed

    Knop, E; Knop, N; Schirra, F

    2009-10-01

    The oily secretion (meibum) of the Meibomian glands forms the superficial layer of the pre-ocular tear film and reduces evaporation of the aqueous phase. Meibum is a complex mixture of various lipids and minor protein components as well as other components of the secretory meibocytes, which form a clear liquid at body temperature. The exact composition and functions of meibum are still partly unknown, in particular the interaction of the water insoluble non-polar lipids with the polar, partly water soluble, lipids and potentially with proteins, which altogether interact to maintain the connection with the underlying aqueous tear phase. Meibum is transported within the gland by the force of secretory pressure from continuous secretion and by muscular action of the orbicularis muscle and Riolans muscles during blinking. After delivery of meibum onto the posterior lid margin the oil moves from the posterior lid margin reservoir onto the tear meniscus and is pulled as a thin layer onto the pre-ocular tear film every time the lid opens. During lid closure it is compressed and a small part is continuously renewed. Meibum also has a barrier function against the spillage of tears over the inner border of the lid and against the entry of skin lipids (sebum) from the free lid margin. PMID:19856011

  20. Development of physiologically based toxicokinetic models for improving the human indoor exposure assessment to water contaminants: trichloroethylene and trihalomethanes.

    PubMed

    Haddad, Sami; Tardif, Ginette-Charest; Tardif, Robert

    2006-12-01

    Generally, ingestion is the only route of exposure that is considered in the risk assessment of drinking water contaminants. However, it is well known that a number of these contaminants are volatile and lipophilic and therefore highly susceptible to being absorbed through other routes, mainly inhalation and dermal. The objective of this study was to develop physiologically based human toxicokinetic (PBTK) models for trihalomethanes (THM) and trichloroethylene (TCE) that will facilitate (1) the estimation of internal exposure to these chemicals for various multimedia indoor exposure scenarios, and (2) consideration of the impact of biological variability in the estimation of internal doses. Five PBTK models describing absorption through ingestion, inhalation and skin were developed for these contaminants. Their concentrations in ambient air were estimated from their respective tap water concentrations and their physicochemical characteristics. Algebraic descriptions of the physiological parameters, varying as a function of age, gender and diverse anthropometric parameters, allow the prediction of the influence of interindividual variations on absorbed dose and internal dosimetry. Simulations for various scenarios were done for a typical human (i.e., 70 kg, 1.7 m) as well as for humans of both genders varying in age from 1 to 90 years. Simulations show that ingestion contributes to less than 50% of the total absorbed dose or metabolized dose for all chemicals. This contribution to internal dosimetry, such as maximal venous blood concentrations (Cmax) and the area under the venous blood concentration time curve (AUC), decreases markedly (e.g., as low as 0.9% of Cmax for bromodichloromethane). The importance of this contribution varies mainly as a function of shower duration. Moreover, model simulations indicate that multimedia exposure is more elevated in children than adults (i.e., up to 200% of the adult internal dose). The models developed in this study allow characterization of the influence of the different routes of exposure and an improved estimation of the realistic multimedia exposure to volatile organic chemicals present in drinking water. Hence, such models will greatly improve health risk assessment for these chemicals. PMID:17060096

  1. Characteristics of a root hair-less line of Arabidopsis thaliana under physiological stresses.

    PubMed

    Tanaka, Natsuki; Kato, Mariko; Tomioka, Rie; Kurata, Rie; Fukao, Yoichiro; Aoyama, Takashi; Maeshima, Masayoshi

    2014-04-01

    The plasma membrane-associated Ca(2+)-binding protein-2 of Arabidopsis thaliana is involved in the growth of root hair tips. Several transgenic lines that overexpress the 23 residue N-terminal domain of this protein under the control of the root hair-specific EXPANSIN A7 promoter lack root hairs completely. The role of root hairs under normal and stress conditions was examined in one of these root hair-less lines (NR23). Compared with the wild type, NR23 showed a 47% reduction in water absorption, decreased drought tolerance, and a lower ability to adapt to heat. Growth of NR23 was suppressed in media deficient in phosphorus, iron, calcium, zinc, copper, or potassium. Also, the content of an individual mineral in NR23 grown in normal medium, or in medium lacking a specific mineral, was relatively low. In wild-type plants, the primary and lateral roots produce numerous root hairs that become elongated under phosphate-deficient conditions; NR23 did not produce root hairs. Although several isoforms of the plasma membrane phosphate transporters including PHT1;1-PHT1;6 were markedly induced after growth in phosphate-deficient medium, the levels induced in NR23 were less than half those observed in the wild type. In phosphate-deficient medium, the amounts of acid phosphatase, malate, and citrate secreted from NR23 roots were 38, 9, and 16% of the levels secreted from wild-type roots. The present results suggest that root hairs play significant roles in the absorption of water and several minerals, secretion of acid phosphatase(s) and organic acids, and in penetration of the primary roots into gels. PMID:24501179

  2. Characteristics of a root hair-less line of Arabidopsis thaliana under physiological stresses

    PubMed Central

    Maeshima, Masayoshi

    2014-01-01

    The plasma membrane-associated Ca2+-binding protein-2 of Arabidopsis thaliana is involved in the growth of root hair tips. Several transgenic lines that overexpress the 23 residue N-terminal domain of this protein under the control of the root hair-specific EXPANSIN A7 promoter lack root hairs completely. The role of root hairs under normal and stress conditions was examined in one of these root hair-less lines (NR23). Compared with the wild type, NR23 showed a 47% reduction in water absorption, decreased drought tolerance, and a lower ability to adapt to heat. Growth of NR23 was suppressed in media deficient in phosphorus, iron, calcium, zinc, copper, or potassium. Also, the content of an individual mineral in NR23 grown in normal medium, or in medium lacking a specific mineral, was relatively low. In wild-type plants, the primary and lateral roots produce numerous root hairs that become elongated under phosphate-deficient conditions; NR23 did not produce root hairs. Although several isoforms of the plasma membrane phosphate transporters including PHT1;1–PHT1;6 were markedly induced after growth in phosphate-deficient medium, the levels induced in NR23 were less than half those observed in the wild type. In phosphate-deficient medium, the amounts of acid phosphatase, malate, and citrate secreted from NR23 roots were 38, 9, and 16% of the levels secreted from wild-type roots. The present results suggest that root hairs play significant roles in the absorption of water and several minerals, secretion of acid phosphatase(s) and organic acids, and in penetration of the primary roots into gels. PMID:24501179

  3. Relationships between heart rate and physiological parameters of performance in top-level water polo players.

    PubMed

    Galy, O; Ben Zoubir, S; Hambli, M; Chaouachi, A; Hue, O; Chamari, K

    2014-03-01

    The aim of this study was to measure the heart rate (HR) response of eight elite water polo players during the four 7-min quarters of the game and to check for relationships with the physiological parameters of performance ([Formula: see text]O2max, Th1vent, Th2vent). Each athlete performed a [Formula: see text]O2max treadmill test and played a water polo game wearing a heart rate monitor. The game fatigue index was calculated as the ratio of the fourth-quarter HR to the first-quarter HR: HR4/HR1. The results showed a slight decrease in fourth-quarter HR compared with the first quarter, with the mean four-quarter HR equal to 79.9±4.2% of HRmax. Stepwise multiple regression analysis showed [Formula: see text]O2max to be the main explanatory factor of game intensity, i.e. game HR expressed in %HRreserve (R=0.88, P<0.01). We observed that higher aerobic capacity resulted in higher game intensity. We also observed a decrease in the playing intensity in the fourth quarter compared with the first, likely due to very high game involvement. We concluded that high aerobic capacity seems necessary to ensure high game intensity in water polo. This suggests that coaches should encourage their athletes to reach a minimum level of [Formula: see text]O2max and that HR monitoring could be of great interest in the control of water polo training sessions. PMID:24917687

  4. Liquid state DNP for water accessibility measurements on spin-labeled membrane proteins at physiological temperatures

    NASA Astrophysics Data System (ADS)

    Doll, Andrin; Bordignon, Enrica; Joseph, Benesh; Tschaggelar, René; Jeschke, Gunnar

    2012-09-01

    We demonstrate the application of continuous wave dynamic nuclear polarization (DNP) at 0.35 T for site-specific water accessibility studies on spin-labeled membrane proteins at concentrations in the 10-100 μM range. The DNP effects at such low concentrations are weak and the experimentally achievable dynamic nuclear polarizations can be below the equilibrium polarization. This sensitivity problem is solved with an optimized home-built DNP probe head consisting of a dielectric microwave resonator and a saddle coil as close as possible to the sample. The performance of the probe head is demonstrated with both a modified pulsed EPR spectrometer and a dedicated CW EPR spectrometer equipped with a commercial NMR console. In comparison to a commercial pulsed ENDOR resonator, the home-built resonator has an FID detection sensitivity improvement of 2.15 and an electron spin excitation field improvement of 1.2. The reproducibility of the DNP results is tested on the water soluble maltose binding protein MalE of the ABC maltose importer, where we determine a net standard deviation of 9% in the primary DNP data in the concentration range between 10 and 100 μM. DNP parameters are measured in a spin-labeled membrane protein, namely the vitamin B12 importer BtuCD in both detergent-solubilized and reconstituted states. The data obtained in different nucleotide states in the presence and absence of binding protein BtuF reveal the applicability of this technique to qualitatively extract water accessibility changes between different conformations by the ratio of primary DNP parameters ɛ. The ɛ-ratio unveils the physiologically relevant transmembrane communication in the transporter in terms of changes in water accessibility at the cytoplasmic gate of the protein induced by both BtuF binding at the periplasmic region of the transporter and ATP binding at the cytoplasmic nucleotide binding domains.

  5. Physiological Responses of a Model Marine Diatom to Fast pH Changes: Special Implications of Coastal Water Acidification

    PubMed Central

    Wu, Yaping; Beardall, John; Gao, Kunshan

    2015-01-01

    Diatoms and other phytoplankton in coastal waters experience rapid pH changes in milieu due to high biological activities and/or upwelled CO2-rich waters. While CO2 concentrating mechanisms (CCMs) are employed by all diatoms tested to counter low CO2 availability in seawater, little is known how this mechanism responds to fast pH changes. In the present study, the model diatom Thalassiosira pseudonana was acclimated for 20 generations to low pH (7.81) at an elevated CO2 of 1000 μatm (HC) or to high pH (8.18) at ambient CO2 levels of 390 μatm (LC), then its physiological characteristics were investigated as cells were shifted from HC to LC or vice versa. The maximal electron transport rate (ETRmax) in the HC-acclimated cells was immediately reduced by decreased CO2 availability, showing much lower values compared to that of the LC-acclimated cells. However, the cells showed a high capacity to regain their photochemical performance regardless of the growth CO2 levels, with their ETRmax values recovering to initial levels in about 100 min. This result indicates that this diatom might modulate its CCMs quickly to maintain a steady state supply of CO2, which is required for sustaining photosynthesis. In addition, active uptake of CO2 could play a fundamental role during the induction of CCMs under CO2 limitation, since the cells maintained high ETR even when both intracellular and periplasmic carbonic anhydrases were inhibited. It is concluded that efficient regulation of the CCM is one of the key strategies for diatoms to survive in fast changing pH environment, e.g. for the tested species, which is a dominant species in coastal waters where highly fluctuating pH is observed. PMID:26496125

  6. Technological and physiological characteristics of a newly developed hand-lever drive system for wheelchairs.

    PubMed

    Engel, P; Seeliger, K

    1986-10-01

    It may be concluded that, by use of the newly developed Swing-Turn-gear system, mobility of the disabled person using wheelchairs outdoors can be improved. The qualities of the drive gear in push and pull action, the free wheel, the full selection of frequency, and the range of moving the hand levers represent important progress in wheelchair engineering research. The handrim drive is an alternative, especially for indoor use. But, for the first time, an indoor wheelchair can be offered as a combination vehicle for both indoor and outdoor use. The acceptance of the new wheelchair integrated Swing-Turn-gear is much better than the conspicuous hand-lever drive in standard outdoor wheelchairs. At present, the German wheelchair manufacturer, MEYRA Vlotho, is preparing the new hand-lever drive system for production. Initially, the drive system will be adapted to a standard indoor wheelchair made by this company. Development of a lever drive system is also in progress in the United States, which employs force transmission characteristics in one direction. PMID:3820120

  7. Behavioral, attitudinal, and physiologic characteristics of smoking and nonsmoking asbestos-exposed shipyard workers

    SciTech Connect

    Li, V.C.; Kim, Y.J.; Terry, P.B.; Cuthie, J.C.; Roter, D.; Emmett, E.A.; Harvey, A.; Permutt, S.

    1983-12-01

    The smoking characteristics of shipyard workers participating in an Asbestos Medical Surveillance Program (N=3991) were assessed. Sources of data were: 1) a self-assessment questionnaire on the smoking history and respiratory symptomatology of the 871 current smokers who participated in the smoking study, and 2) chest roentgenograms and pulmonary function test results and medical records for the entire population. The study population included 1711 current smokers, 988 former smokers and 1292 never smokers. The annual ''quit rate'' for former smokers had increased from less than 1% in 1961 to 4.2% in 1978. Of the 871 current smokers who participated in the smoking study, 19% had resumed smoking after having given up cigarettes for one year or longer. Men in the smoking study were reasonably well informed about the health consequences of smoking. While they perceived themselves to be susceptible to disease, and the disease to be serious, the benefits they saw in quitting were related more to economics and aesthetics than to health. When the results were age adjusted, no differences in rate of pulonary function abnormalities and chest film abnormalities were found betwen current smokers who voluntarily participated in the smoking study and those who did not. All pulmonary function testing abnormality and chest film abnormality rates were significantly lower for former smokers and never smokers.

  8. Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

    NASA Astrophysics Data System (ADS)

    Li, Tianming; Sooseok, Choi; Takayuki, Watanabe

    2012-12-01

    A water plasma was generated by DC arc discharge with a hafnium embedded rod-type cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

  9. Cardiovascular and autonomic responses to physiological stressors before and after six hours of water immersion.

    PubMed

    Florian, John P; Simmons, Erin E; Chon, Ki H; Faes, Luca; Shykoff, Barbara E

    2013-11-01

    The physiological responses to water immersion (WI) are known; however, the responses to stress following WI are poorly characterized. Ten healthy men were exposed to three physiological stressors before and after a 6-h resting WI (32-33°C): 1) a 2-min cold pressor test, 2) a static handgrip test to fatigue at 40% of maximum strength followed by postexercise muscle ischemia in the exercising forearm, and 3) a 15-min 70° head-up-tilt (HUT) test. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), cardiac output (Q), limb blood flow (BF), stroke volume (SV), systemic and calf or forearm vascular resistance (SVR and CVR or FVR), baroreflex sensitivity (BRS), and HR variability (HRV) frequency-domain variables [low-frequency (LF), high-frequency (HF), and normalized (n)] were measured. Cold pressor test showed lower HR, SBP, SV, Q, calf BF, LFnHRV, and LF/HFHRV and higher CVR and HFnHRV after than before WI (P < 0.05). Handgrip test showed no effect of WI on maximum strength and endurance and lower HR, SBP, SV, Q, and calf BF and higher SVR and CVR after than before WI (P < 0.05). During postexercise muscle ischemia, HFnHRV increased from baseline after WI only, and LFnHRV was lower after than before WI (P < 0.05). HUT test showed lower SBP, DBP, SV, forearm BF, and BRS and higher HR, FVR, LF/HFHRV, and LFnHRV after than before WI (P < 0.05). The changes suggest differential activation/depression during cold pressor and handgrip (reduced sympathetic/elevated parasympathetic) and HUT (elevated sympathetic/reduced parasympathetic) following 6 h of WI. PMID:23950166

  10. Soil-water characteristic curves for compacted clays

    SciTech Connect

    Tinjum, J.M.; Benson, C.H.; Blotz, L.R.

    1997-11-01

    Soil-water characteristic curves (SWCCs) are presented for four compacted clay barrier soils that were prepared at different compaction water contents (dry, wet, and optimum water content) and compactive efforts (standard and modified Proctor). The SWCCs were measured in the laboratory using pressure plate extractors. The shape of the SWCC depends on compaction water content and compactive effort, but compaction water content is more important. Compaction at higher compaction water content or with greater compactive effort results in larger air entry. Also, clays with higher plasticity index have greater air-entry suction. Changes in the shape of the SWCC are consistent with changes in pore size that occur by varying compaction conditions and with the mineralogical composition of the soils. These changes in the SWCC also are reflected in the van Genuchten and Brooks-Corey parameters, which were obtained from least-squares fits to the SWCC data. Regression equations are presented that can be used to estimate the van Genuchten parameters {alpha} and n from compaction water content, compactive effort, and plasticity index.

  11. Characteristics of water and carbon balance in moso bamboo forests

    NASA Astrophysics Data System (ADS)

    Kume, T.; Laplace, S.; Tseng, H.; Hsieh, Y.; Wey, T.; Komatsu, H.

    2013-12-01

    Water and carbon cycles in mountainous areas can have considerable impacts on our available nature resources such as water resources and timber production. Thus, it is indispensable to clarify the difference of water and carbon balances between different types of forested ecosystems. Recently, bamboo forests have been expanding by replacing surrounding vegetation such as coniferous and broad-leaved forests in eastern Asian countries. It has been speculated that the replacements by bamboo forests could alter the vegetation water and carbon cycles. However, our knowledge for the bamboo forests was still limited due to lack of applicable methodology based on a field measurement. To clarify the potential impacts of bamboo expansion on water and carbon cycles, our previous study established optimal and effective design for assessing bamboo forest water use (ie, transpiration) based on sap flux measurements. Using the method, we quantified stand-scale transpiration in bamboo forests and coniferous forests in Taiwan. Consequently, we found significantly larger transpiration in bamboo forests compared with those of surrounding vegetation due to larger canopy conductance in bamboo forests. The unique characteristics of the water use accompanied larger carbon assimilation and soil CO2 efflux in bamboo forests.

  12. Using water to cool cattle: behavioral and physiological changes associated with voluntary use of cow showers.

    PubMed

    Legrand, A; Schütz, K E; Tucker, C B

    2011-07-01

    Water is commonly used to cool cattle in summer either at milking or over the feed bunk, but little research has examined how dairy cows voluntarily use water separate from these locations. The objectives were to describe how and when dairy cattle voluntarily used an overhead water source separate from other resources, such as feed, and how use of this water affected behavioral and physiological indicators of heat stress. Half of the 24 nonlactating cattle tested had access to a "cow shower" composed of 2 shower heads activated by a pressure-sensitive floor. All animals were individually housed to prevent competition for access to the shower. Over 5 d in summer (air temperature=25.3±3.3°C, mean ± standard deviation), cattle spent 3.0±2.1 h/24h in the shower, but considerable variability existed between animals (individual daily values ranged from 0.0 to 8.2 h/24h). A portion of this variation can be explained by weather; shower use increased by 0.3h for every 1°C increase in ambient temperature. Cows preferentially used the shower during the daytime, with 89±12% of the time spent in the shower between 1000 and 1900 h. Respiration rate and skin temperature did not differ between treatments [53 vs. 61 breaths/min and 35.0 vs. 35.4°C in shower and control cows, respectively; standard error of the difference (SED)=5.6 breaths/min and 0.49°C]. In contrast, body temperature of cows provided with a shower was 0.2°C lower than control cows in the evening (i.e., 1800 to 2100h; SED=0.11°C). Cows with access to a shower spent half as much time near the water trough than control animals, and this pattern became more pronounced as the temperature-humidity index increased. In addition, cattle showed other behavioral changes to increasing heat load; they spent less time lying when heat load index increased, but the time spent lying, feeding, and standing without feeding did not differ between treatments. Cows had higher respiration rate, skin temperature, and body temperature as heat load index increased, regardless of treatment. These data suggest that cattle, when given the opportunity, will make considerable use of a shower to reduce heat load, but that individuals are highly variable in their use of this resource. The variability between cows indicates that the behavioral response to water is likely an important, but poorly understood, consideration in the design of sprinkler systems used for summer cooling. PMID:21700023

  13. Molecular, Physiological and Biochemical Responses of Theobroma cacao L. Genotypes to Soil Water Deficit

    PubMed Central

    dos Santos, Ivanildes C.; de Almeida, Alex-Alan Furtado; Anhert, Dário; da Conceição, Alessandro S.; Pirovani, Carlos P.; Pires, José L.; Valle, Raúl René; Baligar, Virupax C.

    2014-01-01

    Six months-old seminal plants of 36 cacao genotypes grown under greenhouse conditions were subjected to two soil water regimes (control and drought) to assess, the effects of water deficit on growth, chemical composition and oxidative stress. In the control, soil moisture was maintained near field capacity with leaf water potentials (ΨWL) ranging from −0.1 to −0.5 MPa. In the drought treatment, the soil moisture was reduced gradually by withholding additional water until ΨWL reached values of between −2.0 to −2.5 MPa. The tolerant genotypes PS-1319, MO-20 and MA-15 recorded significant increases in guaiacol peroxidase activity reflecting a more efficient antioxidant metabolism. In relation to drought tolerance, the most important variables in the distinguishing contrasting groups were: total leaf area per plant; leaf, stem and total dry biomass; relative growth rate; plant shoot biomass and leaf content of N, Ca, and Mg. From the results of these analyses, six genotypes were selected with contrasting characteristics for tolerance to soil water deficit [CC-40, C. SUL-4 and SIC-2 (non-tolerant) and MA-15, MO-20, and PA-13 (tolerant)] for further assessment of the expression of genes NCED5, PP2C, psbA and psbO to water deficit. Increased expression of NCED5, PP2C, psbA and psbO genes were found for non-tolerant genotypes, while in the majority of tolerant genotypes there was repression of these genes, with the exception of PA-13 that showed an increased expression of psbA. Mutivariate analysis showed that growth variables, leaf and total dry biomass, relative growth rate as well as Mg content of the leaves were the most important factor in the classification of the genotypes as tolerant, moderately tolerant and sensitive to water deficit. Therefore these variables are reliable plant traits in the selection of plants tolerant to drought. PMID:25541723

  14. Anatomical and physiologic characteristics to predict football ability. Report of study methods and correlations, University of Arkansas, 1976.

    PubMed

    Arnold, J A; Brown, B; Micheli, R P; Coker, T P

    1980-01-01

    In a prospective study of 56 scholarship players at the University of Arkansas in 1976, 14 anatomical and physiologic measurements were carried out on each of the 56 players, to include certain orthopaedic strength, power, and balance tests, and compared to the coaches' subjective ratings of football ability in an effort to determine which characteristics best correlate to the athlete's true performance. The correlation matrix for the criterion measure and the predictor variables of selected anatomical strength, balance, and power measures are presented, and the results of the study indicate that genu varum (0.445) and tibial torsion (-0.33) had the highest correlation with the coaching criterion variable. The average tibial torsion was 42.6 for these scholarship athletes, while normal average tibial torsion among a nonscholarship group was 27.40 degrees. Other anatomical characteristics measured, as well as strength and power measure, could not reach the critical level of +/- 0.263 to be significant at the 0.05 level, although horsepower was close (0.255). The Margaria-Kalamen power test was significantly related to the 40-yard dash, and a moderately good measure of football ability. PMID:7361976

  15. Physiologic, metabolic, and muscle fiber type characteristics of musculus uvulae in sleep apnea hypopnea syndrome and in snorers.

    PubMed Central

    Sériès, F; Côté, C; Simoneau, J A; Gélinas, Y; St Pierre, S; Leclerc, J; Ferland, R; Marc, I

    1995-01-01

    Upper airway dilator muscles play an important role in the pathophysiology of sleep apnea hypopnea syndrome (SAHS). The mechanical and structural characteristics of these muscles remain unknown. The aim of this study was to compare the physiologic, metabolic, and fiber type characteristics of one upper airway dilator muscle (musculus uvulae, MU) in 11 SAHS and in seven nonapneic snorers. The different analyses were done on MU obtained during uvulo-palato-pharyngoplasty. Snorers and SAHS differed only in their apnea + hypopnea indices (11.5 +/- 5.9 and 34.2 +/- 14.6/h, respectively, mean +/- SD). Absolute twitch and tetanic tension production of MU was significantly greater in SAHS than in snorers while the fatigability index was similar in the two groups. Protein content and anaerobic enzyme activities of MU were significantly greater in SAHS than in snorers; no difference was observed for aerobic enzyme activities. The total muscle fiber cross-sectional area of MU was significantly higher in SAHS (2.2 +/- 0.9 mm2) than in snorers (1.1 +/- 0.7 mm2). The surface occupied by type IIA muscle fibers of MU was larger in SAHS (2.00 +/- 0.96) than in snorers (0.84 +/- 0.63 mm2). We conclude that the capacity for tension production and the anaerobic metabolic activity of MU are greater in SAHS than in snorers. PMID:7814616

  16. Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant

    PubMed Central

    Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

    2015-01-01

    Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water. PMID:25893132

  17. Well characteristics influencing arsenic concentrations in ground water.

    PubMed

    Erickson, Melinda L; Barnes, Randal J

    2005-10-01

    Naturally occurring arsenic contamination is common in ground water in the upper Midwest. Arsenic is most likely to be present in glacial drift and shallow bedrock wells that lie within the footprint of northwest provenance Late Wisconsinan glacial drift. Elevated arsenic is more common in domestic wells and in monitoring wells than it is in public water system wells. Arsenic contamination is also more prevalent in domestic wells with short screens set in proximity to an upper confining unit, such as glacial till. Public water system wells have distinctly different well-construction practices and well characteristics when compared to domestic and monitoring wells. Construction practices such as exploiting a thick, coarse aquifer and installing a long well screen yield good water quantity for public water system wells. Coincidentally, these construction practices also often yield low arsenic water. Coarse aquifer materials have less surface area for adsorbing arsenic, and thus less arsenic available for potential mobilization. Wells with long screens set at a distance from an upper confining unit are at lower risk of exposure to geochemical conditions conducive to arsenic mobilization via reductive mechanisms such as reductive dissolution of metal hydroxides and reductive desorption of arsenic. PMID:16135378

  18. Clinical characteristics of idiopathic pulmonary fibrosis patients with gender, age, and physiology staging at Okinawa Chubu Hospital

    PubMed Central

    Shimaoka, Yousuke; Fukuyama, Hajime; Nagano, Hiroaki; Nei, Yuichiro; Yamashiro, Shin; Tamaki, Hitoshi

    2015-01-01

    Background Gender, age, and physiology (GAP) staging was recently advocated for idiopathic pulmonary fibrosis (IPF). However, clinical findings of GAP staging for IPF are limited. We aimed to investigate the clinical characteristics of IPF patients according to GAP staging in our hospital. Methods We retrospectively reviewed patient medical records and chest high-resolution computed tomography (HRCT) images from June 1, 2002, to December 31, 2012. Results We identified 54 IPF patients with [36 men; mean age: 71 years (range, 53-85 years)]. Mean fibrosis and ground glass opacity (GGO) scores were 1.9 (0-4) and 1.6 (1-3.3), respectively. Mean percent predicted forced vital capacity (% FVC), percent predicted diffusing capacity of the lung for carbon monoxide (% DLco) were 70.6 (6.4-114.3), 49.2 (15-105.9), respectively. Cox proportional hazards model showed that gender, percent predicted diffusing capacity of the lung for carbon monoxide (% DLco), and composite physiologic index (CPI) were strong predictors of mortality. Stage III patients had more pulmonary hypertension (50% vs. 23%, 0%) and progressive modified Medical Research Council (mMRC) changes at 1 year (1.3 vs. 0.6, 1.1; P=0.07) compared with other stages. Conclusions In our cohort, GAP staging was useful for evaluating IPF severity. Stage III patients might had more pulmonary hypertension and progressive dyspnea. Multicenter analyses are warranted to confirm these findings. Keywords Idiopathic pulmonary fibrosis (IPF); modified Medical Research Council (mMRC); mortality; pulmonary hypertension; staging PMID:26101639

  19. Physiological and pathological left ventricular hypertrophy of comparable degree is associated with characteristic differences of in vivo hemodynamics.

    PubMed

    Olh, Attila; Nmeth, Balzs Tams; Mtys, Csaba; Hidi, Lszl; Lux, rpd; Ruppert, Mihly; Kellermayer, Dalma; Sayour, Alex Ali; Szab, Lilla; Trk, Marianna; Meltzer, Anna; Gellr, Lszl; Merkely, Bla; Radovits, Tams

    2016-03-01

    Left ventricular (LV) hypertrophy is a physiological or pathological response of LV myocardium to increased cardiac load. We aimed at investigating and comparing hemodynamic alterations in well-established rat models of physiological hypertrophy (PhyH) and pathological hypertrophy (PaH) by using LV pressure-volume (P-V) analysis. PhyH and PaH were induced in rats by swim training and by abdominal aortic banding, respectively. Morphology of the heart was investigated by echocardiography. Characterization of cardiac function was completed by LV P-V analysis. In addition, histological and molecular biological measurements were performed. Echocardiography revealed myocardial hypertrophy of similar degree in both models, which was confirmed by post-mortem heart weight data. In aortic-banded rats we detected subendocardial fibrosis. Reactivation of fetal gene program could be observed only in the PaH model. PhyH was associated with increased stroke volume, whereas unaltered stroke volume was detected in PaH along with markedly elevated end-systolic pressure values. Sensitive indexes of LV contractility were increased in both models, in parallel with the degree of hypertrophy. Active relaxation was ameliorated in athlete's heart, whereas it showed marked impairment in PaH. Mechanical efficiency and ventriculo-arterial coupling were improved in PhyH, whereas they remained unchanged in PaH. Myocardial gene expression of mitochondrial regulators showed marked differences between PaH and PhyH. We provided the first comparative hemodynamic characterization of PhyH and PaH in relevant rodent models. Increased LV contractility could be observed in both types of LV hypertrophy; characteristic distinction was detected in diastolic function (active relaxation) and mechanoenergetics (mechanical efficiency), which might be explained by mitochondrial differences. PMID:26718969

  20. [Effects of different barnyardgrass species on grain yield of rice and their physiological characteristics under alternate wetting and drying irrigation].

    PubMed

    Zhang, Zi-chang; Li, Yong-feng; Yang, Xia; Gu, Tao; Li, Gui

    2015-11-01

    In order to investigate the influence of different barnyardgrass species on rice yield and physiological characteristics of rice, two rice cultivars, Liangyoupeijiu (an indica hybrid cultivar) and Nanjing 9108 (a japonica cultivar) , were employed to co-culture with four barnyardgrass species during the period from transplanting to maturity under alternate wetting and moderate drying ir- rigation condition. The treatments were separately designed as follow: weed free ( control) , rice with Echinochloa crusgalli var. mitis (T1), rice with E. crusgalli (T2), rice with E. crusgali var. zelayensis (T3) and rice with E. colonum (T4). The results showed that T1, T2, T3 and T4 treatments reduced the Liangyoupeijiu yield by 13.8%, 10.6%, 23.8% and 0.5%, but the corresponding yield loss of Nanjing 9108 could reach up to 45.5%, 36.9%, 60.7% and 15.1%, respectively. The results above showed that T1, T2 and T3 treatments all significantly reduced grain yield, and T4 treatment only reduced grain yield for Nanjing 9108 but not for Liangyoupeijiu. All treatments elevated malondialehyde contents of rice leaf, but the activities of peroxidase, catalase, superoxide dimutase, dry matter accumulation in maturity stage, root oxidation activities and contents of indole-3-acetic acid as well as zeatin + zeatin riboside in roots during rice grain filling stage were all decreased. The influence degree of four barnyardgrass against physiological indices of rice had the order of T3 > T1 >T2 > T4. It showed that the reductions in enzyme activities of antioxidant system, root oxidation activities, contents of indole-3-acetic acid, zeatin + zeatin riboside during grain filling stage and accumulation of dry matter in maturity as well as increase in contents of malondialehyde of rice during grain filling stage might be important reasons for grain yield reduction when grew with barnyardgrass. PMID:26915195

  1. Combining leaf physiology, hyperspectral imaging and partial least squares-regression (PLS-R) for grapevine water status assessment

    NASA Astrophysics Data System (ADS)

    Rapaport, Tal; Hochberg, Uri; Shoshany, Maxim; Karnieli, Arnon; Rachmilevitch, Shimon

    2015-11-01

    Physiological measurements are considered to be the most accurate way of assessing plant water status, but they might also be time-consuming, costly and intrusive. Since visible (VIS)-to-shortwave infrared (SWIR) imaging spectrometers are able to monitor various bio-chemical alterations in the leaf, such narrow-band instruments may offer a faster, less expensive and non-destructive alternative. This requires an intelligent downsizing of broad and noisy hyperspectra into the few most physiologically-sensitive wavelengths. In the current study, hyperspectral signatures of water-stressed grapevine leaves (Vitis vinifera L. cv. Cabernet Sauvignon) were correlated to values of midday leaf water potential (Ψl), stomatal conductance (gs) and non-photochemical quenching (NPQ) under controlled conditions, using the partial least squares-regression (PLS-R) technique. It was found that opposite reflectance trends at 530-550 nm and around 1500 nm - associated with independent changes in photoprotective pigment contents and water availability, respectively - were indicative of stress-induced alterations in Ψl, gs and NPQ. Furthermore, combining the spectral responses at these VIS and SWIR regions yielded three normalized water balance indices (WABIs), which were superior to various widely-used reflectance models in predicting physiological values at both the leaf and canopy levels. The potential of the novel WABI formulations also under field conditions demonstrates their applicability for water status monitoring and irrigation scheduling.

  2. Exceptional thermal tolerance and water resistance in the mite Paratarsotomus macropalpis (Erythracaridae) challenge prevailing explanations of physiological limits.

    PubMed

    Wu, Grace C; Wright, Jonathan C

    2015-11-01

    Physiological performance and tolerance limits in metazoans have been widely studied and have informed our understanding of processes such as extreme heat and cold tolerance, and resistance to water loss. Because of scaling considerations, very small arthropods with extreme microclimatic niches provide promising extremophiles for testing predictive physiological models. Corollaries of small size include rapid heating and cooling (small thermal time constants) and high mass-specific metabolic and water exchange rates. This study examined thermal tolerance and water loss in the erythracarid mite Paratarsotomus macropalpis (Banks, 1916), a species that forages on the ground surface of the coastal sage scrub habitat of Southern California, USA. Unlike most surface-active diurnal arthropods, P. macropalpis remains active during the hottest parts of the day in midsummer. We measured water-loss gravimetrically and estimated the critical thermal maximum (CTmax) by exposing animals to a given temperature for 1h and then increasing temperature sequentially. The standardized water flux of 4.4ngh(-1)cm(-2)Pa(-1), averaged for temperatures between 22 and 40C, is among the lowest values reported in the literature. The CTmax of 59.4C is, to our knowledge, the highest metazoan value reported for chronic (1-h) exposure, and closely matches maximum field substrate temperatures during animal activity. The extraordinary physiological performance seen in P. macropalpis likely reflects extreme selection resulting from its small size and resultant high mass-specific water loss rate and low thermal time-constant. Nevertheless, the high water resistance attained with a very thin lipid barrier, and the mite's exceptional thermal tolerance, challenge existing theories seeking to explain physiological limits. PMID:26255840

  3. The clinical physiology of water metabolism. Part III: The water depletion (hyperosmolar) and water excess (hyposmolar) syndromes.

    PubMed

    Weitzman, R E; Kleeman, C R

    1980-01-01

    Hyperosmolality occurs when there are defects in the two major homeostatic mechanisms required for water balance-thirst and arginine vasopressin (AVP) release. In this situation hypotonic fluids are lost in substantial quantities causing depletion of both intracellular and extracellular fluid compartments. Patients with essential hypernatremia have defective osmotically stimulated AVP release and thirst but may have intact mechanisms for AVP release following hypovolemia. Hyperosmolality can also be seen in circumstances in which impermeable solutes are present in excessive quantities in extracellular fluid. Under these conditions there is cellular dehydration and the serum sodium may actually be reduced by water drawn out of cells along an osmotic gradient. Hyposmolality and hyponatremia may be seen in a variety of clinical conditions. Salt depletion, states in which edema occurs and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) may all produce severe dilution of body fluids resulting in serious neurologic disturbances. The differential diagnosis of these states is greatly facilitated by careful clinical assessment of extracellular fluid volume and by determination of urine sodium concentration. Treatment of the hyposmolar syndromes is contingent on the pathophysiology of the underlying disorder; hyponatremia due to salt depletion is treated with infusions of isotonic saline whereas mild hyponatremia in cirrhosis and ascites is best treated with water restriction. Severe symptomatic hyponatremia due to SIADH is treated with hypertonic saline therapy, sometimes in association with intravenous administration of furosemide. Less severe, chronic cases may be treated with dichlormethyltetracycline which blocks the action of AVP on the collecting duct. PMID:6246683

  4. Physiological regulation of evaporative water loss in endotherms: is the little red kaluta (Dasykaluta rosamondae) an exception or the rule?

    PubMed

    Withers, Philip C; Cooper, Christine E

    2014-06-01

    It is a central paradigm of comparative physiology that the effect of humidity on evaporative water loss (EWL) is determined for most mammals and birds, in and below thermoneutrality, essentially by physics and is not under physiological regulation. Fick's law predicts that EWL should be inversely proportional to ambient relative humidity (RH) and linearly proportional to the water vapour pressure deficit (?wvp) between animal and air. However, we show here for a small dasyurid marsupial, the little kaluta (Dasykaluta rosamondae), that EWL is essentially independent of RH (and ?wvp) at low RH (as are metabolic rate and thermal conductance). These results suggest regulation of a constant EWL independent of RH, a hitherto unappreciated capacity of endothermic vertebrates. Independence of EWL from RH conserves water and heat at low RH, and avoids physiological adjustments to changes in evaporative heat loss such as thermoregulation. Re-evaluation of previously published data for mammals and birds suggests that a lesser dependence of EWL on RH is observed more commonly than previously thought, suggesting that physiological independence of EWL of RH is not just an unusual capacity of a few species, such as the little kaluta, but a more general capability of many mammals and birds. PMID:24741015

  5. Human Adult Retinal Pigment Epithelial Stem Cell–Derived RPE Monolayers Exhibit Key Physiological Characteristics of Native Tissue

    PubMed Central

    Blenkinsop, Timothy A.; Saini, Janmeet S.; Maminishkis, Arvydas; Bharti, Kapil; Wan, Qin; Banzon, Tina; Lotfi, Mostafa; Davis, Janine; Singh, Deepti; Rizzolo, Lawrence J.; Miller, Sheldon; Temple, Sally; Stern, Jeffrey H.

    2015-01-01

    Purpose We tested what native features have been preserved with a new culture protocol for adult human RPE. Methods We cultured RPE from adult human eyes. Standard protocols for immunohistochemistry, electron microscopy, electrophysiology, fluid transport, and ELISA were used. Results Confluent monolayers of adult human RPE cultures exhibit characteristics of native RPE. Immunohistochemistry demonstrated polarized expression of RPE markers. Electron microscopy illustrated characteristics of native RPE. The mean transepithelial potential (TEP) was 1.19 ± 0.24 mV (mean ± SEM, n = 31), apical positive, and the mean transepithelial resistance (RT) was 178.7 ± 9.9 Ω·cm2 (mean ± SEM, n = 31). Application of 100 μM adenosine triphosphate (ATP) apically increased net fluid absorption (Jv) by 6.11 ± 0.53 μL·cm2·h−1 (mean ± SEM, n = 6) and TEP by 0.33 ± 0.048 mV (mean ± SEM, n = 25). Gene expression of cultured RPE was comparable to native adult RPE (n = 5); however, native RPE RNA was harvested between 24 and 40 hours after death and, therefore, may not accurately reflect healthy native RPE. Vascular endothelial growth factor secreted preferentially basally 2582 ± 146 pg/mL/d, compared to an apical secretion of 1548 ± 162 pg/mL/d (n = 14, P < 0.01), while PEDF preferentially secreted apically 1487 ± 280 ng/mL/d compared to a basolateral secretion of 864 ± 132 ng/mL/d (n = 14, P < 0.01). Conclusions The new culture model preserves native RPE morphology, electrophysiology, and gene and protein expression patterns, and may be a useful model to study RPE physiology, disease, and transplantation. PMID:26540654

  6. Thrust Characteristics of Water Rocket and Their Improvement

    NASA Astrophysics Data System (ADS)

    Watanabe, Rikio; Tomita, Nobuyuki; Takemae, Toshiaki

    The propulsive characteristics of water rockets are analyzed theoretically and experimentally. The unsteady thrust force acting on a PET bottle and the air pressure inside the bottle are measured simultaneously by the thrust test stand we have developed. The semi-empirical thrust history is obtained utilizing the air pressure history and it is compared with the measured thrust history. The results show qualitative agreement. The observation of the flow inside bottle by a high-speed video camera shows that the air precedes water when it is about to be discharged entirely. We have developed a flow regulator attached to the nozzle cap to reduce the precursor air discharge that is considered as a result of the swirling flow inside the bottle. The experimental results show that the air discharge and the body vibration are suppressed effectively.

  7. Measurement of "turbidity" and related characteristics of natural waters

    USGS Publications Warehouse

    Pickering, R.J.

    1976-01-01

    The U.S. Geological Survey, Water Resources Division has adopted the following principles to be used in selecting methods for the measurement of light transmitting characteristics of natural waters: (1) standard instruments and methods are to be adopted to measure and report in optical units, avoiding ' turbidity ' as a quantitative measure; (2) reporting of ' turbidity ' in JTU 's, Hellige units, severity, or NTU 's will be phased out; (3) the basis for estimations of sediment concentrations based on light measurements must be documented adequately; and (4) use of transparency measurement by Secchi disk is not changed, although light transmittance may prove to be more precise means of obtaining the same information. A schedule has been established to implement new methods beginning October 1, 1976, and with the transition to be completed at all stations by October 1, 1977. Provisions are provided to meet requirements of cooperators who have legal requirements for ' turbidity ' data. (Woodard-USGS)

  8. Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood.

    PubMed

    Park, Sun-Young; Do, Jeong-Ryong; Kim, Young-Jin; Kim, Kee-Sung; Lim, Sang-Dong

    2014-01-01

    Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

  9. Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

    PubMed Central

    Lim, Sang-Dong

    2014-01-01

    Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

  10. The Effect of Phenazine-1-Carboxylic Acid on the Morphological, Physiological, and Molecular Characteristics of Phellinus noxius.

    PubMed

    Huang, Huazhi; Sun, Longhua; Bi, Keke; Zhong, Guohua; Hu, Meiying

    2016-01-01

    In this study, the effect of phenazine-1-carboxylic acid (PCA) on morphological, physiological, and molecular characteristics of Phellinus noxius has been investigated, and the potential antifungal mechanism of PCA against P. noxius was also explored. The results revealed that PCA showed in vitro antifungal potential against P. noxius and completely inhibited P. noxius hyphae at concentrations >40 μg/mL. PCA inhibited both mycelial growth and the loss of mycelial biomass in vitro in a dose-dependent manner. Morphological changes in PCA-treated P. noxius hyphae, such as irregularly swollen mycelia as well as short hyphae with increased septation and less branching, were observed by optical microscopy. The intracellular reactive oxygen species (ROS) levels were significantly increased in PCA-treated P. noxius cells as compared to control groups. Induced hyperpolarization of the mitochondrial membrane potential (MMP), repressed superoxide dismutase (SOD) activity and up-regulated gene expression of seven tested genes were also found in PCA-treated P. noxius groups. Thus, the present results suggested that the mechanism of action of PCA against P. noxius might be attributed to direct damage of mycelium and high intracellular ROS production, and indirect induction of genes involved in cell detoxification, oxidation-reduction process, and electron transport of the respiratory chain. PMID:27187325

  11. Growth and physiological state of the microalgae Phaeodactylum tricornutum Bohlin (Bacillariophyta) in the water taken from peter the Great Bay

    NASA Astrophysics Data System (ADS)

    Zhuravel, Elena; Markina, Zhanna; Aizdaicher, Nina

    2009-09-01

    Bioassay of water from different parts of the Peter the Great Bay using microalgae P. tricornutum revealed that water quality influences not only the growth but also the physiological state of the microalgae. There was no difference in the cell size between control and experimental cultures. Inhibition of microalgae growth was revealed in water with low phosphates concentration, for example, in the Marine Reserve. High phosphates concentration and moderate organic pollution caused the stimulation of miroalgae growth in such sites as the Tumen, the Partizanskaya and the Vtoraya rechka rivers mouths.

  12. Relationship between characteristics of water polo players and efficacy indices.

    PubMed

    Alcaraz, Pedro E; Abraldes, J Arturo; Ferragut, Carmen; Vila, Helena; Rodríguez, Nuria; Argudo, Francisco M

    2012-07-01

    The aim of this study was to define and examine the relationships between the anthropometrical characteristics, maximum isometric grip strength, and competition throwing velocities and efficacy indices in high-level water polo player. Eleven elite trained male water polo players participated in this study. During preseason training, the following measures were taken: standard anthropometry (height, body mass, arm spam, skinfolds, body girths, and skeletal breadths) and grip strength. During official European Competitions (n = 7), efficacy indices (offensives: shot definition, resolution, precision, blocked and defensives: shot resolution when defending and shots stopped when defending), average and maximum throwing velocities from all the participants by zones and in some offensive tactical phases (even, counterattacks and power play) were also determined. Throwing velocities were different (p ≤ 0.05) between some of the offensive tactical phases (even = 17.9 ± 2.4 vs. power play = 16.7 ± 2.6 m·s(-1)). In addition, significant correlations were found between competitive throwing velocities and different offensive efficacy indices. We concluded that there were significant correlations between conditioning and performance variables with anthropometrical characteristics and offensive tactical indices (blocked shots received and shot precision). Coaches should pay attention to these indices for the development of performance throughout the season. PMID:22728942

  13. Effect of drinking water temperature on physiological variables of crossbred dairy cattle at high altitude temperate region of Himalayas

    PubMed Central

    Golher, D. M.; Thirumurugan, P.; Patel, B. H. M.; Upadhyay, V. K.; Sahu, S.; Gaur, G. K.; Bhoite, S. H.

    2015-01-01

    Aim: The objective of study was to investigate the effects of drinking water on certain physiological parameters such as heart rate (HR), respiration rate (RR), rectal temperature (RT) and, ruminal motility (RM). Materials and Methods: The experiment was carried out on 18 farm bred lactating crossbred cows. The animals selected for the study were divided into three groups of six animals each on the basis of milk yield and parity and were allotted to three treatment group of six each such as ambient drinking water temperature at 10.25±0.28°C (ambient water, T1), drinking water temperature at 15-20°C (T2) and drinking water temperature at 35-40°C (T3). All the managemental practices were kept similar during experiment except drinking water temperatures physiological variables such as HR, RR, RT, and RM of the individual cow was measured and recorded twice in a day at 800 h and again at 1400 h two consecutive days in a week 15 min after providing drinking water. Result: HR and RR at morning and at evening recorded were within the normal physiological level for all the treatment groups. However, RT at morning was comparable in all the treatments whereas at evening it was significantly (p<0.01) higher for cows consuming in T2 and in T3 than cows consumed (T1). The RM during morning among the treatments were non-significant as compared to the rumen motility at evening was significantly higher for (T1) and (T2) than for cows in (T3). Conclusion: It can be concluded that offering warm drinking water at 35-40°C to crossbred lactating dairy cow is beneficial during winter at high altitude temperate region. PMID:27047019

  14. Spectral characteristics analysis of red tide water in mesocosm experiment

    NASA Astrophysics Data System (ADS)

    Cui, Tingwei; Zhang, Jie; Zhang, Hongliang; Ma, Yi; Gao, Xuemin

    2003-05-01

    Mesocosm ecosystem experiment with seawater enclosed of the red tide was carried out from July to September 2001. We got four species of biology whose quantities of bion are dominant in the red tide. During the whole process from the beginning to their dying out for every specie, in situ spectral measurements were carried out. After data processing, characteristic spectra of red tide of different dominant species are got. Via comparison and analysis of characteristics of different spectra, we find that in the band region between 685 and 735 nanometers, spectral characteristics of red tide is apparently different from that of normal water. Compared to spectra of normal water, spectra of red tide have a strong reflectance peak in the above band region. As to spectra of red tide dominated by different species, the situations of reflectance peaks are also different: the second peak of Mesodinium rubrum spectrum lies between 726~732 nm, which is more than 21nm away from the other dominant species spectra"s Leptocylindrus danicus"s second spectral peak covers 686~694nm; that of Skeletonema costatum lies between 691~693 nm. Chattonella marina"s second spectral peak lies about 703~705 nm. Thus we can try to determine whether red tide has occurred according to its spectral data. In order to monitor the event of red tide and identify the dominant species by the application of the technology of hyperspectral remote sensing, acquiring spectral data of different dominant species of red tide as much as possible becomes a basic work to be achieved for spectral matching, information extraction and so on based on hyperspectral data.

  15. Characteristic mega-basin water storage behavior using GRACE

    NASA Astrophysics Data System (ADS)

    Famiglietti, J. S.; Reager, J. T.

    2012-12-01

    The NASA GRACE mission now allows hydrologists to study terrestrial water storage variations for the world's largest river basins (>200,000 km2), with monthly time resolution. Because these mega-basins contribute the majority of global runoff, GRACE data are ideally suited for monitoring global water storage variability and classifying differences in basin water storage behavior that are relevant for global climate studies. Here we calculate frequency-domain transfer functions of storage response to precipitation forcing, and then parameterize these transfer functions based on large-scale basin characteristics, such as percent forest cover and basin temperature. This results in a basin-independent relationship between precipitation forcing and storage response as a function of temporal frequency and large-scale basin properties, quantifying fundamental global hydrology relationships that were previously unobservable. Results show that for very large basins, temperature, soil water-holding capacity and percent forest cover are the major controls on relative storage variability, while basin area and mean terrain slope are relatively unimportant. At annual timescales, temperature variability drives storage variability for basins with a mean temperature under 15 deg C, while land surface variables characterize storage variability for warmer basins. At interannual timescales, land surface variables are the largest influence on storage behavior in all basins, with more forested and deeper soiled basins showing reduced response to interannual variability in precipitation forcing. Our results demonstrate the critical importance of forest cover and soil capacity on basin residence times for global-scale studies, and imply that land-atmosphere processes such as precipitation recycling play a critical role in large-basin storage dynamics. The derived empirical relationships were accurate in modeling global-scale water storage anomaly time series for the study basins using only precipitation, average basin temperature, and two land-surface variables, offering the potential for synthesis of basin storage time series beyond the GRACE observational period.

  16. Effects of water sulfate concentration on performance, water intake, and carcass characteristics of feedlot steers.

    PubMed

    Loneragan, G H; Wagner, J J; Gould, D H; Garry, F B; Thoren, M A

    2001-12-01

    Two hundred forty single-source, cross-bred steers (304 kg) were used to evaluate the effects of various water sulfate concentrations on performance, water intake, and carcass characteristics of feedlot steers. Cattle were stratified by weight and assigned within weight blocks to five water treatments. Averaged over time, actual water sulfate concentrations (+/- SEM) were 136.1 (+/- 6.3), 291.2 (+/- 15.3), 582.6 (+/- 16.9), 1,219.2 (+/- 23.7), and 2,360.4 (+/- 68.2) mg/L, respectively. Weather-related data were recorded. Increasing water sulfate concentration resulted in linear decreases in ADG (P < 0.01) and gain:feed ratio (P < 0.01) and a quadratic effect on water intake (P = 0.02) and tended to quadratically increase then decrease DMI (P = 0.13). Sulfate x period interactions were evident for DMI (P = 0.01), ADG (P < 0.01), and feed efficiency (P < 0.01). Time had quadratic effects on DMI, water intake, ADG, and feed efficiency (P < 0.01 for all models). Increasing water sulfate concentration resulted in linear decreases in final weight, hot carcass weight, and dressing percentage, a linear increase in longissimus muscle area, and a quadratic effect on fat thickness over the 12th rib and predicted yield grade (P < 0.05 for all dependent variables). Mean daily temperature explained 25.7% of the observed variation in water intake. Other factors that explained a significant (P < 0.01) amount of variation in water intake were BW, DMI, water sulfate concentration, barometric pressure, wind speed, and humidity. High water sulfate concentrations had a significant and deleterious effect on performance and carcass characteristics of feedlot steers. Increasing the sulfate concentration in water may have resulted in a functional water restriction early in the trial when ambient temperatures were greatest. However, toward the latter stages of the trial, cattle supplied higher-sulfate water had higher ADG and FE. These improvements later in the trial may represent compensatory gain associated with decreased ambient temperature and water requirements. Averaged over time, a water sulfate concentration of greater than 583 mg/L, equivalent to 0.22% of the diet, decreased feedlot performance. PMID:11811445

  17. Definition and characteristics of the water abundant season in Korea

    NASA Astrophysics Data System (ADS)

    Park, So-Ra; Oh, Su-Bin; Byun, Hi-Ryong

    2015-04-01

    In contrast to the normal seasons that are classified by the distribution of temperature and precipitation, this study defines a new concept of the water abundant season (WAS) when water is more abundant than in other seasons. We investigated its characteristics on 60 stations in Korea, and compared it with Changma (the rainy season). In this study, Available Water Resources Index (AWRI), which is a summed daily precipitation accumulated for more than 365 days with a time-dependent reduction function and reflects the current water condition, was used to quantify the water amount. In addition, the median value of 30 year's daily AWRI was used as the criterion value dividing WAS from other seasons. The results show that the terminologies on water resources have changed from qualitative concepts such as abundance, deficit, and continuous rainfall, to quantitative values using AWRI. In detail, it was known that the WAS in Korea starts on 2 July and ends on 25 December, lasting for 176 days. The onset date of WAS in Korea is getting earlier, with a trend of 2.9 days/decade. The end date does later with a delay of 7.5 days/decade, and the duration is increasing at 10.4 days/decade. We looked at the WAS by stations and saw, on average, that 14 June was the earliest onset date in Seogwipo and 29 July was the latest one in Sokcho, representing a difference of 45 days. The earliest end date was in Tongyeong at 5 December and the latest one is in Uljin at 16 January of the following year, a difference of 41 days. Tongyeong had the shortest (166 days) WAS duration and Uljin had the longest (207 days) on average. The big spatial differences of the criterion values per station were detected and quantified. The largest criterion value for WAS were recorded in Seongsan with 270.7 mm, which is almost double of the smallest value, which was recorded in Uiseong (135.9 mm). Comparing WAS with the Changma (the rainy season in Korea) showed that the onset date of WAS is close to that of Changma, but the end date shows a big difference. It is also known that WAS was more useful than Changma in detecting and demonstrating both of the season's progress and the seasonal state of water climates.

  18. Water Jet Impingement Flow Characteristics in Direct Vessel Injection System

    SciTech Connect

    Yoon, Sang H.; Suh, Kune Y.

    2006-07-01

    Water jet impingement is a peculiar phenomenon in the APR1400 (Advanced Power Reactor 1400 MWe) in which the safety injection nozzle is located in the outer reactor vessel, not in the cold leg such as in OPR1000 (Optimized Power Reactor 1,000 MWe). Therefore, the injected emergency core coolant (ECC) water spreads with a form of parabolic liquid film in the inner barrel after impinging. It is presently considered that the downcomer flow behavior is strongly governed by the location and geometry of the water injection nozzles. The impingement in the reactor vessel downcomer is one of the unknown important phenomena during a loss-of-coolant accident (LOCA). There is thus a strong need to find how the injected flow strikes the inner downcomer wall and how wide the liquid film spreads by the impingement phenomenon. The liquid film gets in contact with the steam flow in the reactor downcomer such that the interfacial area of liquid film affects the direct bypass according to the nozzle location and geometry. The water jet impingement consists of three rather distinctive flow regions. Albeit the relevant hydrodynamic characteristics are simple and well known in simple geometries, the findings are not readily applicable in the annular reactor downcomer. Analytical and experimental approaches for impingement flow by water injection have yielded detailed flow mechanisms classified in the downcomer. The water injected through three boundaries showed varying behavior according to the injection velocity, injection nozzle diameter, wall curvature, and injection nozzle inclination. As the water injection velocity increases the liquid film spreading width increases, but the spreading width proportional to the injection velocity is tapered due to breakup. Given the injection velocity, a large diameter of injection nozzle increases the film spreading width. Impingement on the flat plate has a larger film spreading width than on the curved plate. Moreover, a larger curvature decreases the film spreading width. The inclined angle of the injection nozzle is a pivotal factor in reducing the film width by increasing the downward velocity. Given the same conditions, the film spreading width lessens as the inclined angle increases. (authors)

  19. 14 CFR 25.239 - Spray characteristics, control, and stability on water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics, control, and... Water Handling Characteristics § 25.239 Spray characteristics, control, and stability on water. (a) For... (b) of this section, there may be no— (1) Spray characteristics that would impair the pilot's...

  20. [Effects of exogenous nitric oxide on physiological characteristics of longan (Dimocarpus longana) seedlings under acid rain stress].

    PubMed

    Liu, Jian-fu; Wang, Ming-yuan; Yang, Chen; Zhu, Ai-jun

    2013-08-01

    This paper studied the effects of exogenous nitric oxide donor sodium nitroprusside (SNP) on the chlorophyll content, antioxidant enzyme activities, and osmotic regulation substances of longan (Dimocarpus longana 'Fuyan') seedlings under acid rain (pH 3.0) stress. Under the acid rain stress, the seedling leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and chlorophyll, soluble protein and soluble sugar contents decreased obviously, while the leaf malondialdedyde content had a remarkable increase, suggesting the toxic effect of the acid rain on the seedlings. Exogenous nitric oxide had dual nature on the physiological characteristics of longan seedlings under acid rain stress. Applying 0.1-0.5 mmol x L(-1) of SNP improved the SOD, POD and CAT activities and the chlorophyll, soluble protein and soluble sugar contents significantly, and decreased the malondialdedyde content. Low concentrations SNP reduced the oxidative damage caused by the acid rain stress, and 0.5 mmol x L(-1) of SNP had the best effect. Under the application of 0.5 mmol x L(-1) of SNP, the total chlorophyll, soluble protein, and soluble sugar contents and the SOD, POD and CAT activities increased by 76.0%, 107.0%, 216.1%, 150. 0%, 350.9% and 97.1%, respectively, and the malondialdedyde content decreased by 46.4%. It was suggested that low concentration (0.1-0.5 mmol x L(-1)) SNP could alleviate the toxic effect of acid rain stress on longan seedlings via activating the leaf antioxidant enzyme activities and reducing oxidative stress, while high concentration SNP (1.0 mmol x L(-1)) lowered the mitigation effect. PMID:24380343

  1. [Complex effects of simulated acid rain and Cu on the physiological characteristics of Paulownia fortunei and its detoxification mechanism].

    PubMed

    Wang, Jiang; Zhang, Chong-Bang; Ke, Shi-Sheng; Qian, Bao-Ying

    2010-03-01

    A pot experiment was conducted to study the effects of simulated acid rain (pH 4.0, 5.0) and Cu (0-200 mg x kg(-1)) on the physiological characteristics of Paulownia fortunei and its detoxification mechanism. With no Cu addition, the leaf chlorophyll, carotenoid, O2 division by, H2O2, and MDA contents of P. fortunei had no significant differences between the two acid rain treatments. However, with the addition of 100 and 200 mg Cu x kg(-1), the chlorophyll and carotenoid contents of treatment pH 4.0 were lower, while the O2 divided by, H2O2 and MDA contents were higher thanthose of treatment pH 5.0. The chlorophyll a/b ratio of treatments Cu was higher than that of the control. The leaf Cu content decreased obviously with the increasing acidity of stimulated acid rain, but the root Cu content was in reverse. With increasing Cu addition, both the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and the total contents of phytochelatins (PCs) and glutathione (GSH) in treatment pH 5.0 increased, while the activities of SOD, POD, CAT and APX in treatment pH 4.0 decreased after an initial increase, and the total contents of glutathione (GSH) decreased greatly in treatment 200 mg Cu x kg(-1). All of these demonstrated that the oxidative stress of high Cu concentration to P. fortunei was aggravated by stimulated acid rain. PMID:20560310

  2. Within-catchment variation in regulation of water use by eucalypts, and the roles of stomatal anatomy and physiology

    NASA Astrophysics Data System (ADS)

    Gharun, Mana; Turnbull, Tarryn; Adams, Mark

    2014-05-01

    Understanding how environmental cues impact water use of forested catchments is crucial for accurate calculation of water balance and effective catchment management in terrestrial ecosystems. We characterised structural and physiological properties of leaves and canopies of Eucalyptus delegatensis, E. pauciflora and E. radiata, the most common species in high-country catchments in temperate Australia. These properties were related to whole-tree water transport to assess differences in water use strategies among the three species. Stomatal conductance, instantaneous transpiration efficiency, stomatal occlusion (through cuticular ledges) and leaf area index differed significantly among species. Whole-tree water use of all species was strongly coupled to changes in vapour pressure deficit (VPD) and photosynthetically active radiation (Q), yet stomatal closure reduced water transport at VPD > 1 kPa in all species, even when soil water was not limiting. The observed differences in leaf traits and related water use strategies reflect species-specific adaptations to dominant environmental conditions within the landscape matrix of catchments. The generalist E. radiata seems to follow an opportunistic, while the two more spatially restricted species have adopted a pessimistic water use strategy. Catchment-scale models of carbon and water fluxes will need to reflect such variation in structure and function, if they are to fully capture species effects on water balance and yield.

  3. Characteristic mega-basin water storage behavior using GRACE

    PubMed Central

    Reager, J T; Famiglietti, James S

    2013-01-01

    [1] A long-standing challenge for hydrologists has been a lack of observational data on global-scale basin hydrological behavior. With observations from NASA’s Gravity Recovery and Climate Experiment (GRACE) mission, hydrologists are now able to study terrestrial water storage for large river basins (>200,000 km2), with monthly time resolution. Here we provide results of a time series model of basin-averaged GRACE terrestrial water storage anomaly and Global Precipitation Climatology Project precipitation for the world’s largest basins. We address the short (10 year) length of the GRACE record by adopting a parametric spectral method to calculate frequency-domain transfer functions of storage response to precipitation forcing and then generalize these transfer functions based on large-scale basin characteristics, such as percent forest cover and basin temperature. Among the parameters tested, results show that temperature, soil water-holding capacity, and percent forest cover are important controls on relative storage variability, while basin area and mean terrain slope are less important. The derived empirical relationships were accurate (0.54 ≤ Ef ≤ 0.84) in modeling global-scale water storage anomaly time series for the study basins using only precipitation, average basin temperature, and two land-surface variables, offering the potential for synthesis of basin storage time series beyond the GRACE observational period. Such an approach could be applied toward gap filling between current and future GRACE missions and for predicting basin storage given predictions of future precipitation. PMID:24563556

  4. Sensitivity of Terrestrial Water and Energy Budgets to CO2-Physiological Forcing: An Investigation Using an Offline Land Model

    NASA Technical Reports Server (NTRS)

    Gopalakrishnan, Ranjith; Bala, Govindsamy; Jayaraman, Mathangi; Cao, Long; Nemani, Ramakrishna; Ravindranath, N. H.

    2011-01-01

    Increasing concentrations of atmospheric carbon dioxide (CO2) influence climate by suppressing canopy transpiration in addition to its well-known greenhouse gas effect. The decrease in plant transpiration is due to changes in plant physiology (reduced opening of plant stomata). Here, we quantify such changes in water flux for various levels of CO2 concentrations using the National Center for Atmospheric Research s (NCAR) Community Land Model. We find that photosynthesis saturates after 800 ppmv (parts per million, by volume) in this model. However, unlike photosynthesis, canopy transpiration continues to decline at about 5.1% per 100 ppmv increase in CO2 levels. We also find that the associated reduction in latent heat flux is primarily compensated by increased sensible heat flux. The continued decline in canopy transpiration and subsequent increase in sensible heat flux at elevated CO2 levels implies that incremental warming associated with the physiological effect of CO2 will not abate at higher CO2 concentrations, indicating important consequences for the global water and carbon cycles from anthropogenic CO2 emissions. Keywords: CO2-physiological effect, CO2-fertilization, canopy transpiration, water cycle, runoff, climate change 1.

  5. Life under water: physiological adaptations to diving and living at sea.

    PubMed

    Castellini, Michael

    2012-07-01

    This review covers the field of diving physiology by following a chronological approach and focusing heavily on marine mammals. Because the study of modern diving physiology can be traced almost entirely to the work of Laurence Irving in the 1930s, this particular field of physiology is different than most in that it did not derive from multiple laboratories working at many locations or on different aspects of a similar problem. Because most of the physiology principles still used today were first formulated by Irving, it is important to the study of this field that the sequence of thought is examined as a progression of theory. The review covers the field in roughly decadal blocks and traces ideas as they were first suggested, tested, modified and in some cases, abandoned. Because diving physiology has also been extremely dependent on new technologies used in the development of diving recorders, a chronological approach fits well with advances in electronics and mechanical innovation. There are many species that dive underwater as part of their natural behavior, but it is mainly the marine mammals (seals, sea lions, and whales) that demonstrate both long duration and dives to great depth. There have been many studies on other diving species including birds, snakes, small aquatic mammals, and humans. This work examines these other diving species as appropriate and a listing of reviews and relevant literature on these groups is included at the end. PMID:23723028

  6. Molecular mechanisms underlying the physiological responses of the cold-water coral Desmophyllum dianthus to ocean acidification

    NASA Astrophysics Data System (ADS)

    Carreiro-Silva, M.; Cerqueira, T.; Godinho, A.; Caetano, M.; Santos, R. S.; Bettencourt, R.

    2014-06-01

    Cold-water corals (CWCs) are thought to be particularly vulnerable to ocean acidification (OA) due to increased atmospheric pCO2, because they inhabit deep and cold waters where the aragonite saturation state is naturally low. Several recent studies have evaluated the impact of OA on organism-level physiological processes such as calcification and respiration. However, no studies to date have looked at the impact at the molecular level of gene expression. Here, we report results of a long-term, 8-month experiment to compare the physiological responses of the CWC Desmophyllum dianthus to OA at both the organismal and gene expression levels under two pCO2/pH treatments: ambient pCO2 (460 μatm, pHT = 8.01) and elevated pCO2 (997 μatm, pHT = 7.70). At the organismal level, no significant differences were detected in the calcification and respiration rates of D. dianthus. Conversely, significant differences were recorded in gene expression profiles, which showed an up-regulation of genes involved in cellular stress (HSP70) and immune defence (mannose-binding c-type lectin). Expression of alpha-carbonic anhydrase, a key enzyme involved in the synthesis of coral skeleton, was also significantly up-regulated in corals under elevated pCO2, indicating that D. dianthus was under physiological reconditioning to calcify under these conditions. Thus, gene expression profiles revealed physiological impacts that were not evident at the organismal level. Consequently, understanding the molecular mechanisms behind the physiological processes involved in a coral's response to elevated pCO2 is critical to assess the ability of CWCs to acclimate or adapt to future OA conditions.

  7. Eco-physiological response of Populus euphratica Oliv. to water release of the lower reaches of the Tarim River, China

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Ruan, X.; Chen, Y. N.; Li, W. H.

    2007-10-01

    Eco-physiological and plant performance responses and acclimation of Populus euphratica Oliv. to water release of the lower reaches of Tarim River, China were investigated. Three representative areas and 15 transects were selected along the lower reaches of the Tarim River. The groundwater level and salt content as well as plant performance and the contents of proline, soluble sugar, and plant endogenous hormone (ABA, CTK) in leaves were monitored and analyzed before- and after-water release. The groundwater level was raised in different areas and transects by the water release program. The physiological stress to P. euphratica decreased after the water release. Our results suggested that the groundwater level in the studied region changed from -3.15 to -4.12 m, salt content of the groundwater from 67.15 to 72.65 mM, the proline content from 9.28 to 11.06 mM, the soluble sugar content from 224.71 to 252.16 mM, the ABA content from 3.59 to 5.01 ng/(g FW), and the CK content from 4.01 to 4.56 ng/(g FW)- for the optimum growth and recover of P. euphratica indicated by the plant performance parameters, and the efficiency of water release was the highest.

  8. Molecular Dynamics Simulations of a Characteristic DPC Micelle in Water.

    PubMed

    Abel, Stéphane; Dupradeau, François-Yves; Marchi, Massimo

    2012-11-13

    We present the first comparative molecular dynamics investigation for a dodecylphosphocholine (DPC) micelle performed in condensed phase using the CHARMM36, GROMOS53A6, GROMOS54A7, and GROMOS53A6/Berger force fields and a set of parameters developed anew. Our potential consists of newly derived RESP atomic charges, which are associated with the Amber99SB force field developed for proteins. This new potential is expressly designed for simulations of peptides and transmembrane proteins in a micellar environment. To validate this new ensemble, molecular dynamics simulations of a DPC micelle composed of 54 monomers were carried out in explicit water using a "self-assembling" approach. Characteristic micellar properties such as aggregation kinetic, volume, size, shape, surface area, internal structure, surfactant conformation, and hydration were thoroughly examined and compared with experiments. Derived RESP charge values combined with parameters taken from Amber99SB reproduce reasonably well important structural properties and experimental data compared to the other tested force fields. However, the headgroup and alkyl chain conformations or the micelle hydration simulated with the Amber99SB force field display some differences. In particular, we show that Amber99SB slightly overestimates the trans population of the alkyl Csp(3)-Csp(3)-Csp(3)-Csp(3) dihedral angle (i.e., CCCC) and reduces the flexibility of the DPC alkyl chain. In agreement with experiments and previously published studies, the DPC micelle shows a slightly ellipsoidal shape with a radius of gyration of ∼17 Å for the different potentials evaluated. The surface of contact between the DPC headgroup and water molecules represents between 70% and 80% of the total micelle surface independently of the force field considered. Finally, molecular dynamics simulations show that water molecules form various hydrogen-bond patterns with the surfactant headgroup, as noted previously for phospholipids with a phosphatidylcholine headgroup. PMID:26605618

  9. Leaf physiology and biomass allocation of backcross hybrid American chestnut (Castanea dentata) seedlings in response to light and water availability.

    PubMed

    Brown, Caleb E; Mickelbart, Michael V; Jacobs, Douglass F

    2014-12-01

    Partial canopy cover promotes regeneration of many temperate forest trees, but the consequences of shading on seedling drought resistance are unclear. Reintroduction of blight-resistant American chestnut (Castanea dentata (Marsh.) Borkh.) into eastern North American forests will often occur on water-limited sites and under partial canopy cover. We measured leaf pre-dawn water potential (Ψpd), leaf gas exchange, and growth and biomass allocation of backcross hybrid American chestnut seedlings from three orchard sources grown under different light intensities (76, 26 and 8% full photosynthetically active radiation (PAR)) and subjected to well-watered or mid-season water-stressed conditions. Seedlings in the water-stress treatment were returned to well-watered conditions after wilting to examine recovery. Seedlings growing under medium- and high-light conditions wilted at lower leaf Ψpd than low-light seedlings. Recovery of net photosynthesis (Anet) and stomatal conductance (gs) was greater in low and medium light than in high light. Seed source did not affect the response to water stress or light level in most cases. Between 26 and 8% full PAR, light became limiting to the extent that the effects of water stress had no impact on some growth and morphological traits. We conclude that positive and negative aspects of shading on seedling drought tolerance and recovery are not mutually exclusive. Partial shade may help American chestnut tolerate drought during early establishment through effects on physiological conditioning. PMID:25428828

  10. Distribution of characteristics of LWR [light water reactor] spent fuel

    SciTech Connect

    Reich, W.J.; Notz, K.J.; Moore, R.S.

    1991-01-01

    The purpose of this report is to develop a collective description of the entire spent fuel inventory in terms of various fuel properties relevant to Approved Testing Materials (ATMs) using information available from the Characteristics Data Base (CBD), which is sponsored by the US Department of Energy`s (DOE`s) Office of Civilian Radioactive Waste Management. A number of light-water reactor (LWR) characteristics were analyzed including assembly class representation, fuel burnup, enrichment, fuel fabrication data, defective fuel quantities, and, at PNL`s specific request, linear heat generation rate (LHGR) and the utilization of burnable poisons. A quantitative relationships was developed between burnup and enrichment for BWRs and PWRs. The relationship shows that the existing BWR ATM is near the center of the burnup-enrichment distribution, while the four PWR ATMs bracket the center of the burnup range but are on the low side of the enrichment range. Fuel fabrication data are based on vendor specifications for new fuel. Defective fuel distributions were analyzed in terms of assembly class and vendor design. LHGR values were calculated from utility data on burnup and effective full-power days; these calculations incorporate some unavoidable assumptions which may compromise the value of the results. Only a limited amount of data are available on burnable poisons at this time. Based on this distribution study, suggestions for additional ATMs are made. These are based on the class and design concepts and include BWR/2,3 barrier fuel, and the WE 17 {times} 17 class with integral burnable poison. Both should be at relatively high burnups. 16 refs., 5 figs., 15 tabs.

  11. Water-Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    McGehee, John R.; Hathaway, Melvin E.; Vaughan, Victor L., Jr.

    1959-01-01

    Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions.

  12. Effects of longterm elevated carbon dioxide concentration, nitrogen and water availability on the physiology of loblolly pine (Pinus taeda) branches

    SciTech Connect

    Murthy, R.; Dougherty, P.M. )

    1994-06-01

    The objective of this study was to determine to what extent elevated CO[sub 2] alters carbon fixation of loblolly pine when water and nutrition are limiting. Three branches per tree were enclosed in polytene chambers and exposed to ambient, 1.5*ambient and 2*ambient levels of CO[sub 2] respectively for a 12 month period. A 2*2 factorial of nutrition and water was employed. Monthly instantaneous measures of maximum photosynthesis (amax), stomatal conductance and other physiological parameters were taken on needles. Branches exposed to 2* ambient CO[sub 2] in the fertilized and irrigated plots showed significantly higher amax values compared to the other treatment level combinations and showed no signs of acclimation. Results suggest that response to elevated CO[sub 2] levels depends greatly on whether nutrition and water are limiting.

  13. A putative low-molecular-mass penicillin-binding protein (PBP) of Mycobacterium smegmatis exhibits prominent physiological characteristics of DD-carboxypeptidase and beta-lactamase.

    PubMed

    Bansal, Ankita; Kar, Debasish; Murugan, Rajagopal A; Mallick, Sathi; Dutta, Mouparna; Pandey, Satya Deo; Chowdhury, Chiranjit; Ghosh, Anindya S

    2015-05-01

    DD-carboxypeptidases (DD-CPases) are low-molecular-mass (LMM) penicillin-binding proteins (PBPs) that are mainly involved in peptidoglycan remodelling, but little is known about the dd-CPases of mycobacteria. In this study, a putative DD-CPase of Mycobacterium smegmatis, MSMEG_2433 is characterized. The gene for the membrane-bound form of MSMEG_2433 was cloned and expressed in Escherichia coli in its active form, as revealed by its ability to bind to the Bocillin-FL (fluorescent penicillin). Interestingly, in vivo expression of MSMEG_2433 could restore the cell shape oddities of the septuple PBP mutant of E. coli, which was a prominent physiological characteristic of DD-CPases. Moreover, expression of MSMEG_2433 in trans elevated beta-lactam resistance in PBP deletion mutants (ΔdacAdacC) of E. coli, strengthening its physiology as a dd-CPase. To confirm the biochemical reason behind such physiological behaviours, a soluble form of MSMEG_2433 (sMSMEG_2433) was created, expressed and purified. In agreement with the observed physiological phenomena, sMSMEG_2433 exhibited DD-CPase activity against artificial and peptidoglycan-mimetic DD-CPase substrates. To our surprise, enzymic analyses of MSMEG_2433 revealed efficient deacylation for beta-lactam substrates at physiological pH, which is a unique characteristic of beta-lactamases. In addition to the MSMEG_2433 active site that favours dd-CPase activity, in silico analyses also predicted the presence of an omega-loop-like region in MSMEG_2433, which is an important determinant of its beta-lactamase activity. Based on the in vitro, in vivo and in silico studies, we conclude that MSMEG_2433 is a dual enzyme, possessing both DD-CPase and beta-lactamase activities. PMID:25750082

  14. Cold-water immersion and other forms of cryotherapy: physiological changes potentially affecting recovery from high-intensity exercise

    PubMed Central

    2013-01-01

    High-intensity exercise is associated with mechanical and/or metabolic stresses that lead to reduced performance capacity of skeletal muscle, soreness and inflammation. Cold-water immersion and other forms of cryotherapy are commonly used following a high-intensity bout of exercise to speed recovery. Cryotherapy in its various forms has been used in this capacity for a number of years; however, the mechanisms underlying its recovery effects post-exercise remain elusive. The fundamental change induced by cold therapy is a reduction in tissue temperature, which subsequently exerts local effects on blood flow, cell swelling and metabolism and neural conductance velocity. Systemically, cold therapy causes core temperature reduction and cardiovascular and endocrine changes. A major hindrance to defining guidelines for best practice for the use of the various forms of cryotherapy is an incongruity between mechanistic studies investigating these physiological changes induced by cold and applied studies investigating the functional effects of cold for recovery from high-intensity exercise. When possible, studies investigating the functional recovery effects of cold therapy for recovery from exercise should concomitantly measure intramuscular temperature and relevant temperature-dependent physiological changes induced by this type of recovery strategy. This review will discuss the acute physiological changes induced by various cryotherapy modalities that may affect recovery in the hours to days (<5 days) that follow high-intensity exercise. PMID:24004719

  15. Influence of different irrigation levels on the root water uptake and the physiology of root-chicory

    NASA Astrophysics Data System (ADS)

    Vandoorne, B.; Dekoninck, N.; Lutts, S.; Capelle, B.; Javaux, M.

    2009-04-01

    In the context of global warming and given recent heat waves observed in Western Europe, the relationship between the soil water status and the plant health has recently received more attention, especially for cash crops like chicory. In this study we particularly investigated the impact of soil water status on the chicory root water uptake and density and made a link with physiological and yield parameters. During five months, we imposed different irrigation levels to 10 plants of chicory (Cichorium intybus var. sativum) growing in greenhouses. Each seed, coming from an autogamous selection in this allogamous species, was sown in a column of 1.42m height and 0.4m diameter filled with yellow sand and irrigated from the bottom with Hoagland solution. On those 10 columns, we measured the distribution of soil moisture with TDR (8 columns) and ERT (2 columns) probes. Lateral windows also allowed us to follow the root growth. The column weights were also monitored in order to quantify the plant transpiration. During the experiment, several physiological indices were also followed like the gas exchange (CO2 and transpiration), the chlorophyll fluorescence, the stomatal conductance, the plastochron, and the Leaf Area Index (LAI). At the end of the experiment, the complete root length density and the water content profiles were measured. We had also a look to the osmotic potential, the pigments content and the isotopic discrimination of carbon in the leaves, which gives information about the level of stress. At a biochemical point of view, we measured the content in enzymes involves in inulin metabolism and sugars synthesis. We observed that the plants suffering from a slight water stress developed better. A simple1-D model was built which describes the root growth in function of the irrigation level and of the soil and atmospheric boundary conditions.

  16. Estimation of turbulence characteristic scales in a water cell

    NASA Astrophysics Data System (ADS)

    Kulikov, Victor A.; Andreeva, Maria S.; Shmalhausen, Victor I.

    2012-10-01

    Turbulence is one of the key factors responsible for light beam distortions while its propagation through randomly inhomogeneous medium such as the atmosphere. Many common methods of turbulence study are based on the phase or amplitude analyses of the lightwave that have passed through turbulent medium. The significant role of explicit account of the inner and the outer scales in experimental data description is well known. We propose an optical method of turbulence characteristic scales estimation using phase data from Shack-Hartmann sensor obtained of a single laser beam. The method is based on the sequential analysis of normalized correlation functions of Zernike coefficients. It allows the excluding of the structural constant of refractive index value from the analysis and reduces the solution of a two-parameter problem to sequential solution of two single-parameter problems. The method has been applied to analyze the results of measurements performed in a water cell with created turbulence. A horizontal flow was induced to simulate turbulence driftage. It is shown that taking into account the inner scale is necessary for fitting of correlations of the third-order Zernike modes in the experimental error limits for lm/D=0.5 or higher values (lm - the inner scale, D- aperture diameter). Inner scale estimations did not depend on the flow or changes in the temperature difference. We have shown also that taking into account the outer scale is necessary for fitting of experimental correlations of the first-order Zernike modes in the experimental error limits when L0/D<50 (L0 - the outer scale).

  17. A physiological, time-motion, and technical comparison of youth water polo and Acquagoal.

    PubMed

    Lupo, Corrado; Tessitore, Antonio; Cortis, Cristina; Ammendolia, Antonio; Figura, Franceso; Capranica, Laura

    2009-06-01

    The aims of this study were to provide a profile of young water polo players and to compare technical and tactical aspects, movement patterns, and cardiac loads of youth water polo and Acquagoal codes. Ten young (age 12.3 years, s = 0.6) male water polo players underwent anthropometric (stature, body mass, body mass index, chest circumference, hand breadth, and length), strength, and [Vdot]O(2max) evaluations. Friendly youth water polo and Acquagoal matches were arranged to evaluate heart rates and swimming patterns (horizontal and vertical, with and without the ball) of players, and technical and tactical aspects of matches (number of actions, passes, player involved in an action, lost possessions, shots, goals, and the origin and types of shot). Independent of code, matches imposed a high cardiac load on players. Vertical swimming occurred more frequently (P < 0.05) in Acquagoal (71%) than youth water polo (45%). Technical and tactical measures also differed (P < 0.05), with players performing more passes and shots inside the penalty area and showing a higher goal-to-shot ratio during youth water polo than during Acquagoal. These results indicate that youth water polo better resembles the swimming patterns of adult water polo and facilitates the technical and tactical aspects of play better than Acquagoal. PMID:19551550

  18. Linking nitrifying biofilm characteristics and nitrification performance in moving-bed biofilm reactors for polluted raw water pretreatment.

    PubMed

    Zhang, Shuangfu; Wang, Yayi; He, Weitao; Xing, Meiyan; Wu, Min; Yang, Jian; Gao, Naiyun; Sheng, Guangyao; Yin, Daqiang; Liu, Shanhu

    2013-10-01

    Biofilm physiology was characterized by four biofilm constituents, i.e., polysaccharides, proteins (PN), humic-like substances and phospholipids (PL), for the first time to explore the relationships between biofilm characteristics and nitrification performance in moving-bed biofilm reactors (MBBRs) designed for pretreatment of polluted raw surface water for potable supply. The biofilm compositions depended highly on the balance of microbial decay and nitrification processes. The increased ammonia loading greatly regulated the community structure, promoting the dominance of nitrifiers and their proportions in the nitrifying biofilm. Nitrification rate and activity correlated linearly with the fractions of volatile solids (VS), PN and PL, which were related to nitrification processes in the biofilm. The specific biofilm activity demonstrated an exponential-asymptotic relationship with ratios of PN/VS and PL/VS. Thus, analyzing biofilm characteristics can be valid for estimating nitrification performance in MBBRs, and may offer engineers with basis to optimize MBBR design and operation. PMID:23954247

  19. Effect of salinity on biomass yield and physiological and stem-root anatomical characteristics of purslane (Portulaca oleracea L.) accessions.

    PubMed

    Alam, Md Amirul; Juraimi, Abdul Shukor; Rafii, M Y; Abdul Hamid, Azizah

    2015-01-01

    13 selected purslane accessions were subjected to five salinity levels 0, 8, 16, 24, and 32 dS m(-1). Salinity effect was evaluated on the basis of biomass yield reduction, physiological attributes, and stem-root anatomical changes. Aggravated salinity stress caused significant (P < 0.05) reduction in all measured parameters and the highest salinity showed more detrimental effect compared to control as well as lower salinity levels. The fresh and dry matter production was found to increase in Ac1, Ac9, and Ac13 from lower to higher salinity levels but others were badly affected. Considering salinity effect on purslane physiology, increase in chlorophyll content was seen in Ac2, Ac4, Ac6, and Ac8 at 16 dS m(-1) salinity, whereas Ac4, Ac9, and Ac12 showed increased photosynthesis at the same salinity levels compared to control. Anatomically, stem cortical tissues of Ac5, Ac9, and Ac12 were unaffected at control and 8 dS m(-1) salinity but root cortical tissues did not show any significant damage except a bit enlargement in Ac12 and Ac13. A dendrogram was constructed by UPGMA based on biomass yield and physiological traits where all 13 accessions were grouped into 5 clusters proving greater diversity among them. The 3-dimensional principal component analysis (PCA) has also confirmed the output of grouping from cluster analysis. Overall, salinity stressed among all 13 purslane accessions considering biomass production, physiological growth, and anatomical development Ac9 was the best salt-tolerant purslane accession and Ac13 was the most affected accession. PMID:25802833

  20. Effect of Salinity on Biomass Yield and Physiological and Stem-Root Anatomical Characteristics of Purslane (Portulaca oleracea L.) Accessions

    PubMed Central

    Juraimi, Abdul Shukor; Rafii, M. Y.; Abdul Hamid, Azizah

    2015-01-01

    13 selected purslane accessions were subjected to five salinity levels 0, 8, 16, 24, and 32 dS m−1. Salinity effect was evaluated on the basis of biomass yield reduction, physiological attributes, and stem-root anatomical changes. Aggravated salinity stress caused significant (P < 0.05) reduction in all measured parameters and the highest salinity showed more detrimental effect compared to control as well as lower salinity levels. The fresh and dry matter production was found to increase in Ac1, Ac9, and Ac13 from lower to higher salinity levels but others were badly affected. Considering salinity effect on purslane physiology, increase in chlorophyll content was seen in Ac2, Ac4, Ac6, and Ac8 at 16 dS m−1 salinity, whereas Ac4, Ac9, and Ac12 showed increased photosynthesis at the same salinity levels compared to control. Anatomically, stem cortical tissues of Ac5, Ac9, and Ac12 were unaffected at control and 8 dS m−1 salinity but root cortical tissues did not show any significant damage except a bit enlargement in Ac12 and Ac13. A dendrogram was constructed by UPGMA based on biomass yield and physiological traits where all 13 accessions were grouped into 5 clusters proving greater diversity among them. The 3-dimensional principal component analysis (PCA) has also confirmed the output of grouping from cluster analysis. Overall, salinity stressed among all 13 purslane accessions considering biomass production, physiological growth, and anatomical development Ac9 was the best salt-tolerant purslane accession and Ac13 was the most affected accession. PMID:25802833

  1. Brackish Eutrophic Water Treatment by Iris pseudacorus L.-Planted Microcosms: Physiological Responses of Iris pseudacorus L. to Salinity.

    PubMed

    Zhao, Huilin; Wang, Fen; Ji, Min

    2015-01-01

    Iris pseudacorus L. has been widely used in aquatic ecosystem to remove nutrient and has achieved positive effects. However, little is known regarding the nutrient-removal performance and physiological responses of I. pseudacorus for brackish eutrophic water treatment due to high nutrients combined with certain salinity levels. In this study, I. pseudacorus-planted microcosms were established to evaluate the capacity of I. pseudacorus to remove excessive nutrients from fresh (salinity 0.05%) and brackish (salinity 0.5%) eutrophic waters. The degradation of total nitrogen and ammonia nitrogen were not affected by 0.5% salinity; 0.5% salinity promoted the degradation of nitrate nitrogen while severely inhibited the degradation of total phosphorus. Additionally, 0.5% salinity was found to induce stress responses quantified by measuring six physiological indexes. Compared to 0.05% salinity, 0.5% salinity resulted in significant decreases in the chlorophyll a, b and total chlorophyll contents of I. pseudacorus which closely related to photosynthesis (p < 0.05). Furthermore, the higher proline, malondialdehyde contents and antioxidant enzyme activities were detected in I. pseudacorus exposed to 0.5% salinity, which provided protection against reactive oxygen species. The results highlight that the cellular stress assays are efficient for monitoring the health of I. pseudacorus in salinity shock-associated constructed wetlands. PMID:25529785

  2. Antarctic killer whales make rapid, round-trip movements to subtropical waters: evidence for physiological maintenance migrations?

    PubMed

    Durban, J W; Pitman, R L

    2012-04-23

    Killer whales (Orcinus orca) are important predators in high latitudes, where their ecological impact is mediated through their movements. We used satellite telemetry to provide the first evidence of migration for killer whales, characterized by fast (more than 12 km h(-1), 6.5 knots) and direct movements away from Antarctic waters by six of 12 type B killer whales tagged when foraging near the Antarctic Peninsula, including all tags transmitting for more than three weeks. Tags on five of these whales revealed consistent movements to subtropical waters (30-37° S) off Uruguay and Brazil, in surface water temperatures ranging from -1.9°C to 24.2°C; one 109 day track documented a non-stop round trip of almost 9400 km (5075 nmi) in just 42 days. Although whales travelled slower in the warmest waters, there was no obvious interruption in swim speed or direction to indicate calving or prolonged feeding. Furthermore, these movements were aseasonal, initiating over 80 days between February and April; one whale returned to within 40 km of the tagging site at the onset of the austral winter in June. We suggest that these movements may represent periodic maintenance migrations, with warmer waters allowing skin regeneration without the high cost of heat loss: a physiological constraint that may also affect other whales. PMID:22031725

  3. Physiological, Ultrastructural and Proteomic Responses in the Leaf of Maize Seedlings to Polyethylene Glycol-Stimulated Severe Water Deficiency

    PubMed Central

    Shao, Ruixin; Xin, Longfei; Mao, Jun; Li, Leilei; Kang, Guozhang; Yang, Qinghua

    2015-01-01

    After maize seedlings grown in full-strength Hoagland solution for 20 days were exposed to 20% polyethylene glycol (PEG)-stimulated water deficiency for two days, plant height, shoot fresh and dry weights, and pigment contents significantly decreased, whereas malondialdehyde (MDA) content greatly increased. Using transmission electron microscopy, we observed that chloroplasts of mesophyll cells in PEG-treated maize seedlings were swollen, with a disintegrating envelope and disrupted grana thylakoid lamellae. Using two-dimensional gel electrophoresis (2-DE) method, we were able to identify 22 protein spots with significantly altered abundance in the leaves of treated seedlings in response to water deficiency, 16 of which were successfully identified. These protein species were functionally classified into signal transduction, stress defense, carbohydrate metabolism, protein metabolism, and unknown categories. The change in the abundance of the identified protein species may be closely related to the phenotypic and physiological changes due to PEG-stimulated water deficiency. Most of the identified protein species were putatively located in chloroplasts, indicating that chloroplasts may be prone to damage by PEG stimulated-water deficiency in maize seedlings. Our results help clarify the molecular mechanisms of the responses of higher plants to severe water deficiency. PMID:26370980

  4. Physiological, Ultrastructural and Proteomic Responses in the Leaf of Maize Seedlings to Polyethylene Glycol-Stimulated Severe Water Deficiency.

    PubMed

    Shao, Ruixin; Xin, Longfei; Mao, Jun; Li, Leilei; Kang, Guozhang; Yang, Qinghua

    2015-01-01

    After maize seedlings grown in full-strength Hoagland solution for 20 days were exposed to 20% polyethylene glycol (PEG)-stimulated water deficiency for two days, plant height, shoot fresh and dry weights, and pigment contents significantly decreased, whereas malondialdehyde (MDA) content greatly increased. Using transmission electron microscopy, we observed that chloroplasts of mesophyll cells in PEG-treated maize seedlings were swollen, with a disintegrating envelope and disrupted grana thylakoid lamellae. Using two-dimensional gel electrophoresis (2-DE) method, we were able to identify 22 protein spots with significantly altered abundance in the leaves of treated seedlings in response to water deficiency, 16 of which were successfully identified. These protein species were functionally classified into signal transduction, stress defense, carbohydrate metabolism, protein metabolism, and unknown categories. The change in the abundance of the identified protein species may be closely related to the phenotypic and physiological changes due to PEG-stimulated water deficiency. Most of the identified protein species were putatively located in chloroplasts, indicating that chloroplasts may be prone to damage by PEG stimulated-water deficiency in maize seedlings. Our results help clarify the molecular mechanisms of the responses of higher plants to severe water deficiency. PMID:26370980

  5. Antarctic killer whales make rapid, round-trip movements to subtropical waters: evidence for physiological maintenance migrations?

    PubMed Central

    Durban, J. W.; Pitman, R. L.

    2012-01-01

    Killer whales (Orcinus orca) are important predators in high latitudes, where their ecological impact is mediated through their movements. We used satellite telemetry to provide the first evidence of migration for killer whales, characterized by fast (more than 12 km h?1, 6.5 knots) and direct movements away from Antarctic waters by six of 12 type B killer whales tagged when foraging near the Antarctic Peninsula, including all tags transmitting for more than three weeks. Tags on five of these whales revealed consistent movements to subtropical waters (3037 S) off Uruguay and Brazil, in surface water temperatures ranging from ?1.9C to 24.2C; one 109 day track documented a non-stop round trip of almost 9400 km (5075 nmi) in just 42 days. Although whales travelled slower in the warmest waters, there was no obvious interruption in swim speed or direction to indicate calving or prolonged feeding. Furthermore, these movements were aseasonal, initiating over 80 days between February and April; one whale returned to within 40 km of the tagging site at the onset of the austral winter in June. We suggest that these movements may represent periodic maintenance migrations, with warmer waters allowing skin regeneration without the high cost of heat loss: a physiological constraint that may also affect other whales. PMID:22031725

  6. Physiological effects

    SciTech Connect

    Pearcy, R.W.; Bjoerkman, O.

    1983-01-01

    This chapter examines the effects of CO/sub 2/ on plants at the physiological level. The authors examine the potential effects of elevated CO/sub 2/ in concert with water, temperature, light, and salinity. They also examine plant allometric growth as it is affected by CO/sub 2/. The relationships between CO/sub 2/ uptake and temperature are examined in some detail. Stomatal function as it is now known is discussed, along with changes in water use efficiency correlated with increased levels of CO/sub 2/. Future research needs are identified. 71 references, 8 figures.

  7. Growth and physiological responses of tree seedlings to experimental manipulation of light and water

    SciTech Connect

    Huston, M.A.; Holmgren, M.

    1995-06-01

    Seedlings of two tree species with similar tolerance to soil water and nutrient levels, but contrasting tolerance to shade (Acer saccharum and Liriodendron tulipifera) were grown in shade houses under 5 light levels (27%, 17%, 12%, 5%, and 1%) and three soil water regimes (5-9%, 11-15%, and >20%). Soil, light, and water conditions were representative of those in the Walker Branch Throughfall Displacement Experiment, where the same species are being monitored under field conditions. Treatments were maintained from mid-June through October, when all plants were harvested for determination of biomass allocation patterns. The only mortality occurred among the tulip poplars, but there was a significant interaction effect of the treatments on leaf area, total biomass, and allocation patterns. Highest growth rates in both species occurred at 17% light in the highest water treatment, with the 27% treatment showing reduced growth, perhaps due to photoinhibition. Gas exchange measurements indicated that the light compensation point increased under dry conditions.

  8. Physiological integration modifies δ15N in the clonal plant Fragaria vesca, suggesting preferential transport of nitrogen to water-stressed offspring

    PubMed Central

    Roiloa, S. R.; Antelo, B.; Retuerto, R.

    2014-01-01

    Background and Aims One of the most striking attributes of clonal plants is their capacity for physiological integration, which enables movement of essential resources between connected ramets. This study investigated the capacity of physiological integration to buffer differences in resource availability experienced by ramets of the clonal wild strawberry plant, Fragaria vesca. Specifically, a study was made of the responses of connected and severed offspring ramets growing in environments with different water availability conditions (well watered or water stressed) and nitrogen forms (nitrate or ammonium). Methods The experimental design consisted of three factors, ‘integration’ (connected, severed) ‘water status’ (well watered, water stressed) and ‘nitrogen form’ (nitrate, ammonium), applied in a pot experiment. The effects of physiological integration were studied by analysing photochemical efficiency, leaf spectral reflectance, photosynthesis and carbon and nitrogen isotope discrimination, the last of which has been neglected in previous studies. Key Results Physiological integration buffered the stress caused by water deprivation. As a consequence, survival was improved in water-stressed offspring ramets that remained connected to their parent plants. The nitrogen isotope composition (δ15N) values in the connected water-stressed ramets were similar to those in ramets in the ammonium treatment; however, δ15N values in connected well-watered ramets were similar to those in the nitrate treatment. The results also demonstrated the benefit of integration for offspring ramets in terms of photochemical activity and photosynthesis. Conclusions This is the first study in which carbon and nitrogen isotopic discrimination has been used to detect physiological integration in clonal plants. The results for nitrogen isotope composition represent the first evidence of preferential transport of a specific form of nitrogen to compensate for stressful conditions experienced by a member clone. Water consumption was lower in plants supplied with ammonium than in plants supplied with nitrate, and therefore preferential transport of ammonium from parents to water-stressed offspring could potentially optimize the water use of the whole clone. PMID:24769538

  9. Southern Ocean bottom water characteristics in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Heuz, CLine; Heywood, Karen J.; Stevens, David P.; Ridley, Jeff K.

    2013-04-01

    Southern Ocean deep water properties and formation processes in climate models are indicative of their capability to simulate future climate, heat and carbon uptake, and sea level rise. Southern Ocean temperature and density averaged over 1986-2005 from 15 CMIP5 (Coupled Model Intercomparison Project Phase 5) climate models are compared with an observed climatology, focusing on bottom water. Bottom properties are reasonably accurate for half the models. Ten models create dense water on the Antarctic shelf, but it mixes with lighter water and is not exported as bottom water as in reality. Instead, most models create deep water by open ocean deep convection, a process occurring rarely in reality. Models with extensive deep convection are those with strong seasonality in sea ice. Optimum bottom properties occur in models with deep convection in the Weddell and Ross Gyres. Bottom Water formation processes are poorly represented in ocean models and are a key challenge for improving climate predictions.

  10. Physiology and pathophysiology of the vasopressin-regulated renal water reabsorption

    PubMed Central

    Boone, Michelle

    2008-01-01

    To prevent dehydration, terrestrial animals and humans have developed a sensitive and versatile system to maintain their water homeostasis. In states of hypernatremia or hypovolemia, the antidiuretic hormone vasopressin (AVP) is released from the pituitary and binds its type-2 receptor in renal principal cells. This triggers an intracellular cAMP signaling cascade, which phosphorylates aquaporin-2 (AQP2) and targets the channel to the apical plasma membrane. Driven by an osmotic gradient, pro-urinary water then passes the membrane through AQP2 and leaves the cell on the basolateral side via AQP3 and AQP4 water channels. When water homeostasis is restored, AVP levels decline, and AQP2 is internalized from the plasma membrane, leaving the plasma membrane watertight again. The action of AVP is counterbalanced by several hormones like prostaglandin E2, bradykinin, dopamine, endothelin-1, acetylcholine, epidermal growth factor, and purines. Moreover, AQP2 is strongly involved in the pathophysiology of disorders characterized by renal concentrating defects, as well as conditions associated with severe water retention. This review focuses on our recent increase in understanding of the molecular mechanisms underlying AVP-regulated renal water transport in both health and disease. PMID:18431594

  11. The physiological responses of Vallisneria natans to epiphytic algae with the increase of N and P concentrations in water bodies.

    PubMed

    Song, Yu-Zhi; Wang, Jin-Qi; Gao, Yong-Xia; Xie, Xue-Jian

    2015-06-01

    To reveal the mechanism of submerged plants decline in progressively eutrophicated freshwaters, physiological responses of Vallisneria natans to epiphytic algae were studied in simulation lab by measuring plant physiological indexes of chlorophyll content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity based on a 2??4 factorial design with two epiphytic conditions (with epiphytic algae and without) and four levels of N and P concentrations in water (N-P[mg.L(-1)]: 0.5, 0.05; 2.5, 0.25; 4.5, 0.45; 12.5, 1.25). Compared with control (non-presence of epiphytic algae), chlorophyll contents of V. natans were significantly decreased (p?water bodies. While the presence of epiphytic algae induced peroxidation of membrane lipids, MDA contents of V. natans had significantly increased (p?water, and MDA content became higher with the increase of N and P. concentrations. Repeated measurement data testing showed that the effects of epiphytic algae on the chlorophyll content and MDA content and SOD activity were significant, respectively (p?physiology of V. natans and epiphytic algal biomass were positively correlated with nutrient available in the water column. PMID:25548018

  12. Azospirillum and arbuscular mycorrhizal colonization enhance rice growth and physiological traits under well-watered and drought conditions.

    PubMed

    Ruíz-Sánchez, Michel; Armada, Elisabet; Muñoz, Yaumara; García de Salamone, Inés E; Aroca, Ricardo; Ruíz-Lozano, Juan Manuel; Azcón, Rosario

    2011-07-01

    The response of rice plants to inoculation with an arbuscular mycorrhizal (AM) fungus, Azospirillum brasilense, or combination of both microorganisms, was assayed under well-watered or drought stress conditions. Water deficit treatment was imposed by reducing the amount of water added, but AM plants, with a significantly higher biomass, received the same amount of water as non-AM plants, with a poor biomass. Thus, the water stress treatment was more severe for AM plants than for non-AM plants. The results showed that AM colonization significantly enhanced rice growth under both water conditions, although the greatest rice development was reached in plants dually inoculated under well-watered conditions. Water level did not affect the efficiency of photosystem II, but both AM and A. brasilense inoculations increased this value. AM colonization increased stomatal conductance, particularly when associated with A. brasilense, which enhanced this parameter by 80% under drought conditions and by 35% under well-watered conditions as compared to single AM plants. Exposure of AM rice to drought stress decreased the high levels of glutathione that AM plants exhibited under well-watered conditions, while drought had no effect on the ascorbate content. The decrease of glutathione content in AM plants under drought stress conditions led to enhance lipid peroxidation. On the other hand, inoculation with the AM fungus itself increased ascorbate and proline as protective compounds to cope with the harmful effects of water limitation. Inoculation with A. brasilense also enhanced ascorbate accumulation, reaching a similar level as in AM plants. These results showed that, in spite of the fact that drought stress imposed by AM treatments was considerably more severe than non-AM treatments, rice plants benefited not only from the AM symbiosis but also from A. brasilense root colonization, regardless of the watering level. However, the beneficial effects of A. brasilense on most of the physiological and biochemical traits of rice plants were only clearly visible when the plants were mycorrhized. This microbial consortium was effective for rice plants as an acceptable and ecofriendly technology to improve plant performance and development. PMID:21377754

  13. Relating water absorption features to soil moisture characteristics

    NASA Astrophysics Data System (ADS)

    Tian, Jia; Philpot, William D.

    2015-09-01

    The spectral reflectance of a sample of quartz sand was monitored as the sample progressed from air-dry to fully saturated, and then back to air-dry. Wetting was accomplished by spraying small amounts of water on the surface of the sample, and collecting spectra whenever change occurred. Drying was passive, driven by evaporation from the sand surface, with spectra collected every 5 minutes until the sample was air dry. Water content was determined by monitoring the weight of the sample through both wetting and drying. There was a pronounced difference in the pattern of change in reflectance during wetting and drying, with the differences being apparent both in spectral details (i.e., the depth of absorption bands) and in the magnitude of the reflectance for a particular water content. The differences are attributable to the disposition of water in the sample. During wetting, water initially occurred only on the surface, primarily as water adsorbed onto sand particles. With increased wetting the water infiltrated deeper into the sample, gradually covering all particles and filling the pore spaces. During drying, water and air were distributed throughout the sample for most of the drying period. The differences in water distribution are assumed to be the cause of the differences in reflectance and to the differences in the depths of four strong water absorption bands.

  14. Physiology and proteomics of the water-deficit stress response in three contrasting peanut genotypes.

    PubMed

    Kottapalli, Kameswara Rao; Rakwal, Randeep; Shibato, Junko; Burow, Gloria; Tissue, David; Burke, John; Puppala, Naveen; Burow, Mark; Payton, Paxton

    2009-04-01

    Peanut genotypes from the US mini-core collection were analysed for changes in leaf proteins during reproductive stage growth under water-deficit stress. One- and two-dimensional gel electrophoresis (1- and 2-DGE) was performed on soluble protein extracts of selected tolerant and susceptible genotypes. A total of 102 protein bands/spots were analysed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and by quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) analysis. Forty-nine non-redundant proteins were identified, implicating a variety of stress response mechanisms in peanut. Lipoxygenase and 1l-myo-inositol-1-phosphate synthase, which aid in inter- and intracellular stress signalling, were more abundant in tolerant genotypes under water-deficit stress. Acetyl-CoA carboxylase, a key enzyme of lipid biosynthesis, increased in relative abundance along with a corresponding increase in epicuticular wax content in the tolerant genotype, suggesting an additional mechanism for water conservation and stress tolerance. Additionally, there was a marked decrease in the abundance of several photosynthetic proteins in the tolerant genotype, along with a concomitant decrease in net photosynthesis in response to water-deficit stress. Differential regulation of leaf proteins involved in a variety of cellular functions (e.g. cell wall strengthening, signal transduction, energy metabolism, cellular detoxification and gene regulation) indicates that these molecules could affect the molecular mechanism of water-deficit stress tolerance in peanut. PMID:19143990

  15. Effect of Ar Ion Beam Implantation on Morphological and Physiological Characteristics of Liquorice (Glycyrrhiza uralensis Fisch) Under Short-Term Artificial Drought Conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangsheng; Wu, Lijun; Yu, Lixiang; Wei, Shenglin; Liu, Jingnan; Yu, Zengliang

    2007-04-01

    Ar+ ion beam with low energy of 30 keV was implanted into liquorice (Glycyrrhiza uralensis Fisch) seeds at the doses of 0, 600, 900 and 1200 × (2.6 × 1013) ions/cm2, respectively. The seeds were sowed in pots and after one month the plants were subjected to different drought conditions for two months. Then the plants' morphological and physiological characteristics, anti-oxidation enzymes and levels of endogenous hormones were investigated. The results showed that ion implantation at a proper dose can greatly enhance the liquorice seedlings' resistance against drought stress.

  16. Anatomical and physiological regulation of post-fire carbon and water exchange in canopies of two resprouting Eucalyptus species.

    PubMed

    Turnbull, Tarryn L; Buckley, Thomas N; Barlow, Alexandra M; Adams, Mark A

    2014-10-01

    The great majority of Eucalyptus spp. are facultative resprouters, and they dominate the eucalypt forests of Australia. Despite this numeric and geographic dominance, there is a general lack of knowledge of their capacity for carbon capture and water loss during canopy reinstation. After a crown-removing fire, we measured leaf-level determinants of carbon and water flux in resprouting canopies of Eucalyptus dives and E. radiata over the 3 years that followed. Leaf anatomy and physiology changed markedly during canopy reinstation, and leaves produced in the second year (2010) were distinct from those produced later. Leaves produced in 2010 were thicker (all measures of leaf anatomy), yet more porous (increased intercellular airspace), causing specific leaf area also to be greater. Indicators of heterotrophic activity, leaf respiration rate and light compensation point, were twofold greater in 2010, whereas all measures of photosynthetic capacity were greatest in leaves produced in 2011 and 2012. Whilst stomatal density, vein density and leaf hydraulic conductance all progressively decreased with time, neither leaf water status nor carbon isotope discrimination were affected. We conclude that canopy reinstation is primarily limited by pre-fire carbon stores, rather than by post-fire edaphic conditions (e.g., water availability), and thus argue that capacity for recovery is directly linked to pre-fire forest health. PMID:25108550

  17. Physiologically Based Pharmacokinetic modeling of the temperature-dependent dermal absorption of chloroform by humans following bath water exposures

    SciTech Connect

    Corley, Rick A.); Gordon, Syd M.; Wallace, Lance A.

    2000-01-14

    The kinetics of chloroform in the exhaled breath of human volunteers exposed skin-only via bath water (concentrations < 100 ppb) were analyzed using a physiologically based pharmacokinetic (PBPK) model. Significant increases in exhaled chloroform (and thus bioavailability) were observed as exposure temperatures were increased from 30 to 40?C. The blood flows to the skin and effective skin permeability coefficients (Kp) were both varied to reflect the temperature-dependent changes in physiology and exhalation kinetics. At 40?C, no differences were observed between males and females. Therefore, Kp?s were determined ({approx}0.06 cm/hr) at a skin blood flow rate of 18% of the cardiac output. At 30 and 35?C, males exhaled more chloroform than females resulting in lower effective Kp?s calculated for females. At these lower temperatures, the blood flow to the skin was also reduced. Total amounts of chloroform absorbed averaged 41.9 and 43.6 mg for males and 11.5 and 39.9 mg for females exposed at 35 and 40?C, respectively. At 30?C, only 2/5 males and 1/5 females had detectable concentrations of chloroform in their exhaled breath. For perspective, the total intake of chloroform would have ranged from 79 - 194 mg if the volunteers had consumed 2 L of water orally at the concentrations used in this study. Thus, the relative contribution of dermal uptake of chloroform to the total body burdens associated with bathing for 30 min and drinking 2 L of water (ignoring contributions from inhalation exposures) was predicted to range from 1-28% depending on the temperature of the bath.

  18. Physiological ecology of desert iguana (Dipsosaurus dorsalis) eggs: temperature and water relations

    SciTech Connect

    Muth, A.

    1980-12-01

    The soil environment imposes constraints on the timing of oviposition and the location of suitable sites for egg burrows of the desert iguana (Dipsosaurus dorsalis). The effects of temperature and water potential on the developmental period and hatching success of eggs were determined. Eggs hatch normally between 28/sup 0/ and 38/sup 0/C at environmental water potentials between -50 and -1500 kPa. Predictions were derived for the timing and placement of egg clutches based on soil water potential and temperature profiles measured in the field and on the results of laboratory incubation experiments. The results suggest that egg burrows should be located at depths >22 cm in washes or possibly in sparsely vegetated areas away from creosote bushes. The biogeography of desert iguanas within the United States is discussed in relation to soil environments and tolerances of eggs. The physical factors affecting incubation may limit the geographical range of desert iguanas.

  19. Effects of triploidy induction on physiological and immunological characteristics of rainbow trout (Oncorhynchus mykiss) at early developmental stages (fertilized eggs, eyed eggs and fry).

    PubMed

    Salimian, Shekoofeh; Keyvanshokooh, Saeed; Salati, Amir Parviz; Pasha-Zanoosi, Hossein; Babaheydari, Samad Bahrami

    2016-02-01

    The aim of this study was to compare effects of triploidy induction on basal physiological and immunological characteristics in rainbow trout at three developmental stages including fertilized eggs, eyed eggs and fry. Eggs and milt were taken from eight females and six males. The gametes were pooled to minimize the individual differences. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. The first-feeding offspring were also reared under the same environmental and nutritional conditions for 38 days. Triplicate samples of 30 eggs (10 eggs per trough) from each group were selected 1.5h post-fertilization and at the eyed stage. Based on red blood cell analysis, nine diploid and nine triploid fish were also selected for study. The triploidy induction success rate was 87.1%. While diploid fish had greater body weights than those in the heat-shock treatment group, weight gain (WG%) was not different between the fry of the diploid and heat-shock treatment groups. Of thyroid hormones measured, 3,5,3'-triiodo-l-thyronine (T3) was less (P<0.05) in eyed eggs of the heat-shock treatment group, but thyroxine (T4) was greater in fry of the heat-shock treatment group as compared to those that were diploid. Cortisol concentration was greater in fry of the heat-shock treatment group as compared to those that were diploid suggesting that fry in the triploid state may be more susceptible to stressors. Concentrations of immune variables (lysozyme, ACH50, albumin, IgM, total protein, globulin and complement) were either comparable or greater in fry of the heat-shock treatment group suggesting that the immune system is not impaired in fish as a result of triploidy induction. PMID:26725940

  20. Facing the river gauntlet: understanding the effects of fisheries capture and water temperature on the physiology of coho salmon.

    PubMed

    Raby, Graham D; Clark, Timothy D; Farrell, Anthony P; Patterson, David A; Bett, Nolan N; Wilson, Samantha M; Willmore, William G; Suski, Cory D; Hinch, Scott G; Cooke, Steven J

    2015-01-01

    An improved understanding of bycatch mortality can be achieved by complementing field studies with laboratory experiments that use physiological assessments. This study examined the effects of water temperature and the duration of net entanglement on physiological disturbance and recovery in coho salmon (Oncorhynchus kisutch) after release from a simulated beach seine capture. Heart rate was monitored using implanted electrocardiogram biologgers that allowed fish to swim freely before and after release. A subset of fish was recovered in respirometers to monitor metabolic recovery, and separate groups of fish were sacrificed at different times to assess blood and white muscle biochemistry. One hour after release, fish had elevated lactate in muscle and blood plasma, depleted tissue energy stores, and altered osmoregulatory status, particularly in warmer (15 vs. 10°C) and longer (15 vs. 2 min) capture treatments. A significant effect of entanglement duration on blood and muscle metabolites remained after 4 h. Oxygen consumption rate recovered to baseline within 7-10 h. However, recovery of heart rate to routine levels was longer and more variable, with most fish taking over 10 h, and 33% of fish failing to recover within 24 h. There were no significant treatment effects on either oxygen consumption or heart rate recovery. Our results indicate that fishers should minimize handling time for bycatch and maximize oxygen supply during crowding, especially when temperatures are elevated. Physiological data, such as those presented here, can be used to understand mechanisms that underlie bycatch impairment and mortality, and thus inform best practices that ensure the welfare and conservation of affected species. PMID:25901952

  1. Facing the River Gauntlet: Understanding the Effects of Fisheries Capture and Water Temperature on the Physiology of Coho Salmon

    PubMed Central

    Raby, Graham D.; Clark, Timothy D.; Farrell, Anthony P.; Patterson, David A.; Bett, Nolan N.; Wilson, Samantha M.; Willmore, William G.; Suski, Cory D.; Hinch, Scott G.; Cooke, Steven J.

    2015-01-01

    An improved understanding of bycatch mortality can be achieved by complementing field studies with laboratory experiments that use physiological assessments. This study examined the effects of water temperature and the duration of net entanglement on physiological disturbance and recovery in coho salmon (Oncorhynchus kisutch) after release from a simulated beach seine capture. Heart rate was monitored using implanted electrocardiogram biologgers that allowed fish to swim freely before and after release. A subset of fish was recovered in respirometers to monitor metabolic recovery, and separate groups of fish were sacrificed at different times to assess blood and white muscle biochemistry. One hour after release, fish had elevated lactate in muscle and blood plasma, depleted tissue energy stores, and altered osmoregulatory status, particularly in warmer (15 vs. 10°C) and longer (15 vs. 2 min) capture treatments. A significant effect of entanglement duration on blood and muscle metabolites remained after 4 h. Oxygen consumption rate recovered to baseline within 7–10 h. However, recovery of heart rate to routine levels was longer and more variable, with most fish taking over 10 h, and 33% of fish failing to recover within 24 h. There were no significant treatment effects on either oxygen consumption or heart rate recovery. Our results indicate that fishers should minimize handling time for bycatch and maximize oxygen supply during crowding, especially when temperatures are elevated. Physiological data, such as those presented here, can be used to understand mechanisms that underlie bycatch impairment and mortality, and thus inform best practices that ensure the welfare and conservation of affected species. PMID:25901952

  2. WATER STRESS ON PUNA CHICORY AND LANCELOT PLANTAIN - MORPHOLOGICAL AND PHYSIOLOGICAL EFFECTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Summer growth of cool-season species in the NE USA is reduced due to a combination of high temperature and drought. A two year experiment near State College, PA was designed to compare the effect of soil water availability conditions on chicory (Cichorium intybus L.) and plantain (Plantago lanceolat...

  3. Effect of benzyl butyl phthalate on physiology and proteome characterization of water celery (Ipomoea aquatica Forsk.).

    PubMed

    Chen, Wen-Ching; Huang, Han-Ching; Wang, Yei-Shung; Yen, Jui-Hung

    2011-07-01

    This study examined the effect of benzyl butyl phthalate (BBP), a phthalate ester (PAE) and an endocrine disruptor, on water celery, Ipomoea aquatica Forsk., one of the most popular leaf vegetables in Taiwan. After 28 days of cultivation, treatment with 100 mgL⁻¹ BBP retarded plant growth and decreased biomass and number of mature leaves and caused the accumulation of proline in leaves of water celery, but the concentrations of chlorophyll a and b in the leaves remained constant. 2-D gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the proteome of leaf tissue revealed five protein spots with up- and down-regulated expression. The predicted protein XP_001417439 was down-regulated, which explained inhibition of plant growth, and the proteina XP_001417040, calreticulin, GAI-like protein 1, and (-)-linalool synthase were up-regulated, which indicates interference with the cell cycle and protein synthesis, as well as dwarfism of water celery. BBP is a stressor on the growth of water celery, and proteome analysis revealed the up- and down-regulation of genes involved in plant growth with BBP treatment. PMID:21496923

  4. Physiology and proteomics of the water-deficit stress response in three contrasting peanut genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut (Arachis hypogaea L.) accessions from the US mini core collection were analyzed for differentially expressed leaf proteins during reproductive stage under water-deficit stress. Accessions showing tolerant and susceptible responses to stress were selected based on a bioassay involving chloroph...

  5. INSTABILITY OF THE WATER DISINFECTION BY-PRODUCT DIBROMOACETONITRILE UNDER PHYSIOLOGICAL CONDITIONS: KINETICS AND PRODUCT CHARACTERIZATION

    EPA Science Inventory

    Dibromoacetonitrile (DBAN) is a prevalent haloacetonitrile formed as a byproduct of water chlorination. DBAN is toxic in vivo and genotoxic in vitro and is a mouse skin tumor initiator. However, little is known about its mechanisms of toxicity or genotoxicity or its stability. Du...

  6. Rating of Perceived Exertion and Physiological Responses in Water-Based Exercise.

    PubMed

    Pinto, Stephanie Santana; Alberton, Cristine Lima; Zaffari, Paula; Cadore, Eduardo Lusa; Kanitz, Ana Carolina; Liedtke, Giane Veiga; Tartaruga, Marcus Peikriszwili; Kruel, Luiz Fernando Martins

    2015-12-22

    The aim of the present study was to relate the overall rating of perceived exertion (RPE-overall) with cardiorespiratory and neuromuscular variables during stationary running with the elbow flexion/extension performed with water-floating equipment. The sample consisted of eleven women that performed the water-based exercise at submaximal cadences. The heart rate, oxygen uptake, ventilation, and electromyographic signal (EMG) from biceps brachii (%EMG BB), triceps brachii (%EMG TB), biceps femoris (%EMG BF) and rectus femoris (%EMG RF) muscles were measured during the exercise, and the overall RPE was measured immediately following its completion. The Pearson product-moment linear correlation was used to investigate associations between the variables analyzed in the present study. Significant relationships were observed between the RPE-overall and all the cardiorespiratory variables, with the r values ranging from 0.60 to 0.70 (p<0.05). In addition, the RPE-overall showed a significant (p<0.05) relationship with %EMG BB (r=0.55) and %EMG BF (r=0.50). These results suggest an association between the RPE-overall with all cardiorespiratory and two neuromuscular variables during the execution of a water-based aerobic exercise using water-floating equipment. PMID:26839610

  7. Rating of Perceived Exertion and Physiological Responses in Water-Based Exercise

    PubMed Central

    Pinto, Stephanie Santana; Alberton, Cristine Lima; Zaffari, Paula; Cadore, Eduardo Lusa; Kanitz, Ana Carolina; Liedtke, Giane Veiga; Tartaruga, Marcus Peikriszwili; Kruel, Luiz Fernando Martins

    2015-01-01

    The aim of the present study was to relate the overall rating of perceived exertion (RPE-overall) with cardiorespiratory and neuromuscular variables during stationary running with the elbow flexion/extension performed with water-floating equipment. The sample consisted of eleven women that performed the water-based exercise at submaximal cadences. The heart rate, oxygen uptake, ventilation, and electromyographic signal (EMG) from biceps brachii (%EMG BB), triceps brachii (%EMG TB), biceps femoris (%EMG BF) and rectus femoris (%EMG RF) muscles were measured during the exercise, and the overall RPE was measured immediately following its completion. The Pearson product-moment linear correlation was used to investigate associations between the variables analyzed in the present study. Significant relationships were observed between the RPE-overall and all the cardiorespiratory variables, with the r values ranging from 0.60 to 0.70 (p<0.05). In addition, the RPE-overall showed a significant (p<0.05) relationship with %EMG BB (r=0.55) and %EMG BF (r=0.50). These results suggest an association between the RPE-overall with all cardiorespiratory and two neuromuscular variables during the execution of a water-based aerobic exercise using water-floating equipment. PMID:26839610

  8. Impact of water and feed deprivation on physiological parameters in steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A report in rats demonstrated that dehydration as the result of 8 d of water deprivation increased leakage of endotoxin from the intestine (Zurovsky and Barbiro, 2000 Experimental and toxicologic pathology 52:37-42). Given the large number of gram negative bacteria in the rumen of cattle, a much sho...

  9. RESIDUE CHARACTERISTICS FOR WIND AND WATER EROSION CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Standing residue is an effective means of controlling erosion and preventing dust emission in areas prone to wind erosion. In northern climates, standing stubble retains snow deposits and enhances soil water, and in areas affected by water erosion, surface residue is an effective means of protecting...

  10. Characteristics of the absorbed dose to water standard at ENEA.

    PubMed

    Guerra, A S; Laitano, R F; Pimpinella, M

    1996-04-01

    The primary standard of absorbed dose to water established at ENEA for the Co-60 gamma-ray quality is based on a graphite calorimeter and an ionometric transfer system. This standard was recently improved after a more accurate assessment of some perturbation effects in the calorimeter and a modification of the water phantom shape and size. The conversion procedure requires two corresponding depths, one in graphite and one in water, where the radiation energy spectra must be the same. The energy spectra at the corresponding points were determined by a Monte Carlo simulation in water and graphite scaled phantoms. A thorough study of the calorimeter gap effect corrections was also made with regard to their dependence on depth and field size. A comparison between the ionization chamber calibration procedures based on the standards of absorbed dose to water and of air kerma was also made, confirming the consistency of the two methods. PMID:8730663

  11. Oxygen flux as an indicator of physiological stress in aquatic organisms: a real-time biomonitoring system of water quality

    NASA Astrophysics Data System (ADS)

    Sanchez, Brian C.; Yale, Gowri; Chatni, Rameez; Ochoa-Acuña, Hugo G.; Porterfield, D. Marshall; Mclamore, Eric S.; Sepúlveda, María S.

    2009-05-01

    The detection of harmful chemicals and biological agents in real time is a critical need for protecting water quality. We studied the real-time effects of five environmental contaminants with differing modes of action (atrazine, pentachlorophenol, cadmium chloride, malathion, and potassium cyanide) on respiratory oxygen consumption in 2-day post-fertilization fathead minnow (Pimephales promelas) eggs. Our objective was to assess the sensitivity of fathead minnow eggs using the self-referencing micro-optrode technique to detect instantaneous changes in oxygen consumption after brief exposures to low concentrations of contaminants. Oxygen consumption data indicated that the technique is indeed sensitive enough to reliably detect physiological alterations induced by all contaminants. After 2 h of exposure, we identified significant increases in oxygen consumption upon exposure to pentachlorophenol (100 and 1000 μg/L), cadmium chloride (0.0002 and 0.002 μg/L), and atrazine (150 μg/L). In contrast, we observed a significant decrease in oxygen flux after exposures to potassium cyanide (5.2, 22, and 44 μg/L) and atrazine (1500 μg/L). No effects were detected after exposures to malathion (200 and 340 μg/L). We have also tested the sensitivity of Daphnia magna embryos as another animal model for real-time environmental biomonitoring. Our results are so far encouraging and support further development of this technology as a physiologically coupled biomonitoring tool for the detection of environmental toxicants.

  12. Environmental Physiology of the Mangrove Rivulus, Kryptolebias marmoratus, A Cutaneously Breathing Fish That Survives for Weeks Out of Water

    PubMed Central

    Wright, Patricia A.

    2012-01-01

    The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na+, Cl−, and H2O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH3 volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses. PMID:22693260

  13. Environmental physiology of the mangrove rivulus, Kryptolebias marmoratus, a cutaneously breathing fish that survives for weeks out of water.

    PubMed

    Wright, Patricia A

    2012-12-01

    The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na(+), Cl(-), and H(2)O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH(3) volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses. PMID:22693260

  14. The Influence Of Water Tracks And Hillslope Position On The Physiology Of The Dominant Plant Species In The Imnavait Creek Watershed, Alaska

    NASA Astrophysics Data System (ADS)

    Griffin, K. L.; Epstein, D. J.; Shapiro, J. B.; Boelman, N. T.; Stieglitz, M.

    2003-12-01

    Within a small arctic tundra watershed located on the north slope of Alaska, we asked if plant abundance and physiological performance are linked to hillslope position by the hydrologic processes controlling nutrient availability. Our prediction was that down slope sites and within water track sites should have the greatest nutrient availability resulting in the highest photosynthetic capacity and productivity. To examine these relationships, two transects were established in the Imnavait Creek watershed, running from the northern ridge crest to a beaded stream. In total, 16 sites, one water track (WT) and one non water track (NWT), from 8 locations, each 100 m apart were examined. At each site, soil moisture, thaw depth, canopy water status (from spectral reflectance) and species diversity were recorded. Chlorophyll fluorescence was used assess the maximum capacity of each species to transport electrons within the photosynthetic membranes of individual leaves (ETRMAX), a variable we expect to reflect both leaf N and general photosynthetic capacity. Significant differences were found within and among the major functional groups of plants growing in the watershed. In the two deciduous shrubs, Betula nana and Salix pulchra, ETRMAX generally decreased down slope but no significant difference were found between the WT and NWT sites. By contrast, ETRMAX in Rubus chamaemors, also a deciduous species, showed an initial decrease at the first two locations, but then remained constant further down slope and between WT and NWT sites. In the evergreen plants, Ledum palustre differed in that the maximum ETRMAX was found at the mid-slope locations while Vaccinium vitis-idaea had a characteristic decrease in ETRMAX down slope, with a large difference between WT and NWT at the first location. The forb Petasites frigidus displayed a unique pattern, with large difference in ETRMAX between WT and NWT at sites 4 and 5, the last two locations at which this species could be found. Finally, the only graminoid species studied, Eriophorum vaginatu, ETRMAX decrease down slope in a linear fashion and had the highest absolute ETRMAX. Additionally leaf gas-exchange was measured in Salix pulchra and leaf N and canopy reflectance was measured at each site. Together, our results demonstrate that while hillsope position has a significant effect on the physiology, growth and diversity of species, the relationships were not as hypothesized. Clearly other ecological, morphological or environmental factors are contributing to the productivity of the watershed and ultimately impacting the biogeochemistry of this important ecosystem.

  15. Characteristics of dissolved carbon change in irrigation water

    NASA Astrophysics Data System (ADS)

    Akaike, Y.; Kunishio, A.; Kawamoto, Y.; Murakami, H.; Iwata, T.

    2012-12-01

    It is necessary to estimate carbon emission from soil for understanding carbon cycle processes in cultivated fields. Since irrigation water is introduced into a typical rice paddy field, one part of emitted carbon content from soil were trapped by water and dissolved in it, and dissolved carbon content outflows from the field at the drainage moment. In this study, we continuously and regularly analyzed dissolved carbon content of irrigation water and investigated seasonal variation of efflux of carbon from a paddy field. Experimental site is located reclaimed land in the southern part of Okayama Prefecture, Japan. And rice cropping cultivation has continued in a similar method every year. Intermittent irrigation water managements, or 3 days flooded and 4 days drained condition, were carried out during almost all the period of rice cultivated term. Irrigation water was sampled every flooding and drainage days. Inorganic carbon (IC) concentration was measured with total carbon (TC) analyzer (TOC-V/CSH, SHIMAZU). Amount of dissolved carbon in irrigation water was calculated from product of the carbon concentration and water levels. The experimental paddy field was divided into two areas, and two bottle of water were sampled from each area. In order to investigate what impact is brought on the annual carbon cycle by the difference of disposal management of residual biomass after the harvest, residual biomass was burned and plowed into soil at the one area on 29th Nov., 2011, and residue was not burned and directly plowed into soil at the other area as usual. IC during cultivated term in 2011 and 2012 in both area gradually increased day by day for every flooded periods. And IC showed distinct diurnal variations with lower value in the daytime than at night, it is because of photosynthetic activities by aquatic algae in the irrigation water.

  16. Spatiotemporal characteristics and water budget of water cycle elements in different seasons in northeast China

    NASA Astrophysics Data System (ADS)

    Zhou, Jie; Zhao, Jun-Hu; He, Wen-Ping; Zhi-Qiang, Gong

    2015-04-01

    In this paper, we study the spatiotemporal characteristics of precipitable water, precipitation, evaporation, and water-vapor flux divergence in different seasons over northeast China and the water balance of that area. The data used in this paper is provided by the European Center for Medium-Range Weather Forecasts (ECMWF). The results show that the spatial distributions of precipitable water, precipitation, and evaporation feature that the values of elements above in the southeastern area are larger than those in the northwestern area; in summer, much precipitation and evaporation occur in the Changbai Mountain region as a strong moisture convergence region; in spring and autumn, moisture divergence dominates the northeast of China; in winter, the moisture divergence and convergence are weak in this area. From 1979 to 2010, the total precipitation of summer and autumn in northeast China decreased significantly; especially from 1999 to 2010, the summer precipitation always demonstrated negative anomaly. Additionally, other elements in different seasons changed in a truly imperceptible way. In spring, the evaporation exceeded the precipitation in northeast China; in summer, the precipitation was more prominent; in autumn and winter, precipitation played a more dominating role than the evaporation in the northern part of northeast China, while the evaporation exceeded the precipitation in the southern part. The Interim ECMWF Re-Analysis (ERA-Interim) data have properly described the water balance of different seasons in northeast China. Based on ERA-Interim data, the moisture sinks computed through moisture convergence and moisture local variation are quite consistent with those computed through precipitation and evaporation, which proves that ERA-Interim data can be used in the research of water balance in northeast China. On a seasonal scale, the moisture convergence has a greater influence than the local moisture variation on a moisture sink, and the latter is variable slightly, generally as a constant. Likewise, in different seasons, the total precipitation has a much greater influence than the evaporation on the moisture sink. Project supported by the State Key Development Program for Basic Research of China (Grant Nos. 2013CB430204 and 2012CB955902) and the National Natural Science Foundation of China (Grant Nos. 41175067, 41175084, and 41205040).

  17. Uptake and physiological response of crop plants irrigated with water containing RDX and TNT

    SciTech Connect

    Simini, M.; Checkai, R.T.

    1995-12-31

    Regulatory agencies have expressed concern about possible bioconcentration of TNT (2,4,6-trinitrotoluene) and RDX (cyclotrimethylenetrinitramine) in food and forage crops irrigated with contaminated groundwater. Field and home-garden crops grown in site-collected soil were irrigated with water containing RDX and TNT to simulate field conditions at Cornhusker Army Ammunition Plant (CAAP), Nebraska. Pots were watered in an environment-controlled greenhouse to field capacity throughout the life-cycle of each crop with 2, 20, and 100 ppb RDX; 2, 100, and 800 ppb TNT; 100 ppb RDX + 800 ppb TNT; or uncontaminated water in response to evapo-transpirative demand. Uptake of RDX in lettuce leaves, corn stover, and alfalfa shoots was positively correlated with treatment level, however, concentrations of RDX in these crops were generally equal to or below soil loading concentrations. RDX was not significantly (p = 0.05) taken up into tomato fruit, bush bean seeds and pods, radish roots, and soybean seeds. TNT was not significantly take up into tissues of any of the crops analyzed in this study. Yield and biomass of tomato fruit, bush bean fruit, corn stover, and soybean seeds were significantly (p = 0.05) less when irrigated with the RDX + TNT treatment compared to controls. Lettuce leaf, radish root, and alfalfa shoot yield and biomass were unaffected by treatment level. For site-specific criteria used in this study, RDX and TNT did not bioconcentrate in edible plant tissues. This is the first controlled study to investigate uptake of RDX and TNT in crops irrigated with water containing explosives concentrations commonly found in contaminated groundwater.

  18. Physiological properties of Scomber japonicus meat hydrolysate prepared by subcritical water hydrolysis.

    PubMed

    Choi, Jae-Suk; Moon, Hye Eun; Roh, Myong-Kyun; Ha, Yu-Mi; Lee, Bo-Bae; Cho, Kwang Keun; Choi, In Soon

    2016-01-01

    The health-beneficial biological activities, including antioxidant and tyrosinase inhibitory activities, of Scomber japonicus muscle protein hydrolysates prepared by subcritical water hydrolysis were investigated. After 5 min of subcritical hydrolysis at 140 degrees C, 59.76% of S. japonicus muscle protein was hydrolyzed, the highest degree of hydrolysis in all the groups were tested. According to the response surface methodology results, as the reaction temperature and reaction time became lower and shorter, the yield became higher. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity (90.63%) occurred in hydrolysates treated at 140 degrees C for 5 min, and the highest tyrosinase inhibitory activity (65.54%) was identified in hydrolysates treated at 200 degreesC for 15 min. Changes in the molecular weight distribution of S. japonicus muscle proteins after subcritical water hydrolysis were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Subcritical water hydrolysis is a suitable technique for obtaining S.japonicus muscle protein hydrolysates with useful biological activities, within a short time (5-15 min). PMID:26930861

  19. WATER TEMPERATURE CHARACTERISTICS OF LAKES SUBJECTED TO CLIMATE CHANGE

    EPA Science Inventory

    A deterministic, one dimensional, unsteady lake water temperature model was modified and validated to simulate the seasonal (spring to fall) temperature stratification structure over a wide range of lake morphometries, trophic and meteorological conditions. odel coefficients rela...

  20. VIRULENCE CHARACTERISTICS OF HETEROTROPHIC BACTERIA COMMONLY ISOLATED FROM POTABLE WATER

    EPA Science Inventory

    Heterotrophic bacteria isolated from drinking water distribution systems were examined to determine if they possessed putative virulence factors such as hemolysins, proteases, or cytotoxins. Representative samples of colonies from several different distribution systems indicated ...

  1. OCCURRENCE OF HETEROTROPHIC BACTERIA WITH VIRULENCE CHARACTERISTICS IN POTABLE WATER

    EPA Science Inventory

    Treated potable water contains a variety of heterotrophic bacteria that survive current treatment processes. There is evidence that these bacteria are not hazardous to the healthy population, however, the possibility exists that some of them may be opportunistic pathogens capabl...

  2. Using physiologically based pharmacokinetic models to estimate the health risk of mixtures of trihalomethanes from reclaimed water.

    PubMed

    Niu, Zhiguang; Zang, Xue; Zhang, Ying

    2015-03-21

    To estimate the health risk of mixture of trihalomethanes (THMs) from reclaimed water during toilet flushing, the interaction-based Hazard Index (HI(interaction-based)) and the mixture carcinogenic risk (CRM) according to tissue dose were conducted through the integrated use of both the exposure concentrations model and the physiologically based pharmacokinetic (PBPK) model of THMs. Monte Carlo simulations were employed to implement the probabilistic risk analysis and sensitivity analysis. Nine samples were analyzed, which were collected from J Water Reclamation Plant (JWRP) in Tianjin of China. The results indicated that the mean HI(interaction-based) (=0.85) was lower than the acceptable risk level (=1). The probability that the HI(interaction-based) exceeded the acceptable risk level is 22.97%. For carcinogenic risk, the CRM ranges from 9.41×10(-7) to 3.54×10(-5), with a mean of 5.49×10(-6). Moreover, the probability of exceeding the acceptable risk level (1×10(-6)) is near 100%. And the values of HI(interaction-based) from sample no. 1, 5, and 7 exceeded 1, while the values of CRM for all samples exceeded 1×10(-6). Consequently, the reclaimed water used for flushing toilets should be paid more attention, though non-carcinogenic effect is relatively small. Furthermore, the concentrations of DBCM had greater impact on both the carcinogenic and non-carcinogenic risk based on sensitivity analysis. PMID:25497033

  3. NMR Water Self–Diffusion and Relaxation Studies on Sodium Polyacrylate Solutions and Gels in Physiologic Ionic Solutions

    PubMed Central

    Bai, Ruiliang; Basser, Peter J.; Briber, Robert M.; Horkay, Ferenc

    2013-01-01

    Water self-diffusion coefficients and longitudinal relaxation rates in sodium polyacrylate solutions and gels were measured by NMR, as a function of polymer content and structure in a physiological concentration range of monovalent and divalent cations, Ca2+ and Na+. Several physical models describing the self-diffusion of the solvent were applied and compared. A free-volume model was found to be in good agreement with the experimental results over a wide range of polymer concentrations. The longitudinal relaxation rate exhibited linear dependence on polymer concentration below a critical concentration and showed non-linear behavior at higher concentrations. Both the water self-diffusion and relaxation were less influenced by the polymer in the gel state than in the uncrosslinked polymer solutions. The effect of Na+ on the mobility of water molecules was practically undetectable. By contrast, addition of Ca2+ strongly increased the longitudinal relaxation rate while its effect on the self-diffusion coefficient was much less pronounced. PMID:24409001

  4. The physiological resilience of fern sporophytes and gametophytes: advances in water relations offer new insights into an old lineage

    PubMed Central

    Pittermann, Jarmila; Brodersen, Craig; Watkins, James E.

    2013-01-01

    Ferns are some of the oldest vascular plants in existence and they are the second most diverse lineage of tracheophytes next to angiosperms. Recent efforts to understand fern success have focused on the physiological capacity and stress tolerance of both the sporophyte and the gametophyte generations. In this review, we examine these insights through the lens of plant water relations, focusing primarily on the form and function of xylem tissue in the sporophyte, as well as the tolerance to and recovery from drought and desiccation stress in both stages of the fern life cycle. The absence of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes. Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and variously sized megaphylls are shared between ferns and more derived lineages, and offer an opportunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Fern gametophytes show a high degree of desiccation tolerance but new evidence shows that morphological attributes in the gametophytes may facilitate water retention, though little work has addressed the ecological significance of this variation. We conclude with an emergent hypothesis that selection acted on the physiology of both the sporophyte and gametophyte generations in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic. PMID:23935601

  5. Effects of temperature and light intensity on growth and physiology in purple root water hyacinth and common water hyacinth (Eichhornia crassipes).

    PubMed

    Shu, Xiao; Zhang, QuanFa; Wang, WeiBo

    2014-11-01

    In this study, the interaction between temperature and light intensity was investigated in common water hyacinth (CWH) and purple root water hyacinth (PRWH). Effects of different temperatures (11/5, 18/11, 25/18, and 32/25 °C day/night) simultaneously applied at various light intensities (100, 300, and 600 μmol m(-2) s(-1)) to the plants were detected by measuring changes in the root lengths, protein content, sugar content, malondialdehyde (MDA) content, photosynthesis, and dissolved oxygen (DO). Temperature and light intensity significantly influence the growth of water hyacinths, and there was significant interaction among these environmental factors. The results suggest that several environmental factors act synergistically on the growth and physiology of water hyacinths. The higher new root length (NRL) in PRWH indicated that its root growth capacity is higher than in CWH. The soluble sugar content in leaves of CWH was higher than PRWH, indicating that relatively higher sugar content in CWH to low-temperature stress may support its tolerant nature. Lower temperature and light intensity can stimulate the accumulation of MDA content. The net photosynthetic rate (Pn) in leaves of CWH was higher than PRWH. In low temperature, increase light intensity can stimulate the Pn of PRWH and CWH. In CWH and PRWH, Pn showed a similar trend as noted for stomatal conductance (Cond) and transpiration rate (Tr). The capacity of PRWH in adding oxygen to the water column is better than those of CWH. PMID:24994106

  6. Evaluation of a computer program used to estimate water characteristic curve

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soil water characteristic curve, h(theta), can be used to estimate a variety of parameters in unsaturated soils. One practical application of h(theta) is its use by DRAINMOD, a drainage model that has been widely used in shallow water table regions, to determine the water table depth–drainage v...

  7. Alcohol and dilution water characteristics in distilled anis (ouzo).

    PubMed

    Karapanagioti, Hrissi K; Bekatorou, Argyro

    2014-05-28

    The authenticity of some mixed drinks such as vodka or rum was correlated to the conductivity of the dilution water. Authentic drinks demonstrated low conductivity, suggesting the use of treated water, whereas fraud drinks were mixed with regular tap water. The objective of the present study was to test if this criterion is valid for distilled anis, also known as ouzo. Several Greek distilled anis samples, mostly ouzo samples, were tested for different parameters including conductivity, pH, and percentage of different alcohol constituents. Because ouzo in Greece is commonly produced by small enterprises, no correlation between conductivity and the size of the producer was possible. Neither was it possible to correlate the price or high consumption with conductivity and, thus, prior water treatment. Alcohol quality in terms of undesirable constituents, such as methanol content, was good and comparable among samples. In ouzo, water is related to the producer quality goal for the final product and, thus, it is treated and used accordingly. PMID:24816147

  8. Effects of in ovo injection of electrolyte solutions on the pre- and posthatch physiological characteristics of broilers.

    PubMed

    McGruder, B M; Zhai, W; Keralapurath, M M; Bennett, L W; Gerard, P D; Peebles, E D

    2011-05-01

    Effects of the automated in ovo injection of various concentrations and volumes of physiological electrolyte solutions and a carbohydrate-electrolyte solution (CEN) on broiler embryo development and posthatch chick performance were investigated in 5 individual consecutive trials to test potential diluents for commercial injection. A 200-µL saline solution (117 mM) injection treatment and a noninjected control were included in all trials. For the first 4 trials, solutions were injected into the amnion of embryos on d 16 of incubation, and subsequent percentage incubational egg weight loss, embryo mortality, proportional embryo BW, embryo moisture content, proportional yolk sac weight, and yolk moisture content were evaluated on d 18. In trial 5, solutions were injected into the amnion on d 18, and subsequent hatchability and posthatch performance were investigated. In trial 1, a 200-μL injection of 5 mM tripotassium citrate (C(6)H(5)K(3)O(7)) and a 200-μL injection of CEN at 1:400 and 1:8,000 concentrations had no detrimental effect on proportional embryo BW. However, embryo moisture content was increased by the injection of either solution at all concentrations. In trial 2, 200-μL injections of saline, potassium chloride (KCl), or sodium dihydrogen phosphate (NaH(2)PO(4)) solution at various physiological concentrations did not affect any of the parameters examined. In trial 3, the injection of 2,000 µL of 117 mM saline reduced 0 to 18 d percentage egg weight loss. In trial 4, percentage egg weight loss was reduced and embryo moisture was increased by a 200-μL saline (117 mM) injection, but not by 200 μL of solutions of CEN (1:400), C(6)H(5)K(3)O(7) (5.0 mM), or NaH(2)PO(4) (1.0 mM) in 5.5 mM KCl. Compared with controls in trial 5, plasma refractive index was increased by CEN-KCl (1:400-5.5 mM) and saline (117 mM) injections, but not by C(6)H(5)K(3)O(7)-KCl (5 mM-5.5 mM). The current study indicated that 5.5 mM KCl and 5 mM C(6)H(5)K(3)O(7) have the greatest potential for use individually or in combination for the commercial injection of broiler hatching eggs. PMID:21489955

  9. Dynamic characteristics of mixtures of plutonium, Nevada tuff, and water

    SciTech Connect

    Myers, W.; Rojas, S.; Kimpland, R.H.; Jaegers, P.J.; Sanchez, R.G.; Hayes, D.; Paternoster, R.; Anderson, R.; Stratton, W.

    1996-02-01

    One of the technical options being considered for long term disposition of weapons grade plutonium is geologic storage at Yucca Mountain. Multikilogram quantities of plutonium are to be vitrified, placed within a heavy steel container, and buried in the material know as Nevada tuff. It has been postulated that after ten thousand years, geologic and chemical processes would have disintegrated the steel container and created the possibility for plutonium to form mixtures with Nevada tuff and water that could lead to a nuclear explosion in the range of kilotons. A survey and description of critical homogeneous mixtures of plutonium, silicon dioxide, Nevada tuff, and water which also identified the mixture regimes where autocatalytic dynamic behavior is possible was completed. This study is a follow up of this survey and the major objective is to examine the dynamic behavior of the worst case critical and supercritical configurations of plutonium, water and Nevada tuff.

  10. Characteristics of hydrogen bond revealed from water clusters

    NASA Astrophysics Data System (ADS)

    Song, Yan; Chen, Hongshan; Zhang, Cairong; Zhang, Yan; Yin, Yuehong

    2014-09-01

    The hydrogen bond network is responsible for the exceptional physical and chemical properties of water, however, the description of hydrogen bond remains a challenge for the studies of condensed water. The investigation of structural and binding properties of water clusters provides a key for understanding the H-bonds in bulk water. In this paper, a new set of geometric parameters are defined to describe the extent of the overlap between the bonding orbital of the donor OH and the nonbonding orbital of the lone-pair of the acceptor molecule. This orbital overlap plays a dominant role for the strength of H-bonds. The dependences of the binding energy of the water dimer on these parameters are studied. The results show that these parameters properly describe the H-bond strength. The ring, book, cage and prism isomers of water hexamer form 6, 7, 8 and 9 H-bonds, and the strength of the bonding in these isomers changes markedly. The internally-solvated and the all-surface structures of (H2O) n for n = 17, 19 and 21 are nearly isoenergetic. The internally-solvated isomers form fewer but stronger H-bonds. The hydrogen bonding in the above clusters are investigated in detail. The geometric parameters can well describe the characters of the H-bonds, and they correlate well with the H-bond strength. For the structures forming stronger H-bonds, the H-bond lengths are shorter, the angle parameters are closer to the optimum values, and their rms deviations are smaller. The H-bonds emanating from DDAA and DDA molecules as H-donor are relatively weak. The vibrational spectra of (H2O) n ( n = 17, 19 and 21) are studied as well. The stretching vibration of the intramolecular OH bond is sensitive to its bonding environment. The H-bond strength judged from the geometric parameters is in good agreement with the bonding strength judged from the stretching frequencies.

  11. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae

    PubMed Central

    Mahmood, Maziah; Abdullah, Siti N. A.; Hanafi, Mohamed M.; Nejat, Naghmeh; Latif, Muhammad A.

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world’s most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  12. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae.

    PubMed

    Azizi, Parisa; Rafii, Mohd Y; Mahmood, Maziah; Abdullah, Siti N A; Hanafi, Mohamed M; Nejat, Naghmeh; Latif, Muhammad A; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world's most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  13. The fate of glyphosate in water hyacinth and its physiological and biochemical influences on growth of algae

    SciTech Connect

    Tsai, Baolong.

    1989-01-01

    Absorption, translocation, distribution, exudation, and guttation of {sup 14}C-glyphosate in water hyacinth (Eichhornia crassipes) were studied. Glyphosphate entered the plant by foliage and solution treatment. Plants were harvested and separated into the following parts: treated leaf blade, treated leaf petiole, young leaf blade, young leaf petiole, old leak blade, old leaf petiole, and root. Each part was extracted with methanol. Treated leaves, which exist only in foliage treatment, were washed with water and chloroform to remove the glyphosate residues. All {sup 14}C counting was made by liquid scintillation spectrometry. Autoradiography was used to locate {sup 14}C-glyphosate after foliage treatment. Results indicated that glyphosate can be absorbed from the leaf surface and translocated rapidly through phloem tissues into the whole plant body. The roots of water hyacinth absorbed glyphosate without vertical transport. Guttation of glyphosate occurred in treated leaf tips. Exudation of glyphosate from roots of water hyacinth occurred within 8 hr after foliage treatment. Chlorella vulgaris, Chlamydomonas reihardii, Anabaena cylindrica, and Chroococcus turgidus were used to explore the physiological and biochemical effects of glyphosate on algae. Spectrophotometric assays were performed for algal growth, chlorophyll, carotenoids, phycobiliprotein, carbohydrate, and protein. TLC procedures and an image analyzer were used to detect the metabolites of glyphosate inside algal cells. The common visible symptom of glyphosate toxicity in all algal cells were bleaching effect and reduction of contents of carbohydrate, protein, and pigments. The results highly suggested that glyphosate injured the algal cells by destruction of photosynthetic pigments and resulted in lowering the contents of carbohydrate and protein in algal cells.

  14. Infiltration characteristics of bare soil under sequential water application events

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The marked reduction in infiltration rate caused by formation of a soil surface seal is a well known phenomenon but often ignored in infiltration models. The effect sequential water application events have on infiltration rate and soil surface seal formation has rarely been investigated. The objecti...

  15. Effect of Sweet Wormwood Artemisia annua Crude Leaf Extracts on Some Biological and Physiological Characteristics of the Lesser Mulberry Pyralid, Glyphodes pyloalis

    PubMed Central

    Khosravi, Roya; Sendi, Jalal Jalali; Ghadamyari, Mohammad; Yezdani, Elham

    2011-01-01

    The lesser mulberry pyralid, Glyphodes pyloalis Walker (Lepidoptera: Pyralidae) is a monophagous and dangerous pest of mulberry that has been recently observed in Guilan province, northern Iran. In this study, the crude methanol extract of sweet wormwood Artemisia annua L. (Asterales: Asteracaea) was investigated on toxicity, biological and physiological characteristics of this pest under controlled conditions (24 ± 1 °C, 75 ± 5% RH, and 16:8 L:D photoperiod). The effect of acute toxicity and sublethal doses on physiological characteristics was performed by topical application. The LC50 and LC20 values on fourth instar larvae were calculated as 0.33 and 0.22 gram leaf equivalent/ mL, respectively. The larval duration of fifth instar larvae in LC50 treatment was prolonged (5.8 ± 0.52 days) compared with the control group (4.26 ± 0.29 days). However larval duration was reduced in the LC20 treatment. The female adult longevity in the LC50 dose was the least (4.53 ± 0.3 days), while longevity among controls was the highest (9.2 ± 0.29 days). The mean fecundity of adults after larval treatment with LC50 was recorded as 105.6 ± 16.84 eggs/female, while the control was 392.74 ± 22.52 eggs/female. The percent hatchability was reduced in all treatments compared with the control. The effect of extract in 0.107, 0.053, 0.026 and 0.013 gle/mL on biochemical characteristics of this pest was also studied. The activity of α-amylase and protease 48 hours post—treatment was significantly reduced compared with the control. Similarly lipase, esterase, and glutathione S-transferase activity were significantly affected by A. annua extract. PMID:22239100

  16. Fouling characteristics of cooling tower water containing corrosion inhibitors

    SciTech Connect

    Santoso, E.

    1987-01-01

    Corrosion inhibitors investigated included zinc-chromate and phosphates. In addition, additives including polyacrylate and phosphonate (HEDP and AMP) were used to determine their effectiveness as antifoulants. The tests were conducted in a simulated cooling tower water system. The parameters investigated were: test section surface temperature 130, 145 and 160{degree}F, velocity in test section 3.0, 5.5 and 8.5 ft/sec, pH 6.0 -8.0, and material of the fouling surface (stainless steel, carbon steel, 90/10 copper/nickel, and admiralty brass). The water bulk temperature in all tests was 115{degree}F. The water had a total hardness of 800-1000 ppm as CaCO{sub 3}, total sulfate of 800-1000 ppm as SO{sub 4} and silica of 40-45 ppm as SiO{sub 2}. For each test, a fouling resistance - time curve was obtained. This curve was fitted to the equation Rf = Rf (1-exp(-({theta}-{theta}d)/{theta}c)) to yield the values of {theta}c and Rf{sup *}. Rf is the fouling resistance predicted by the regression equation, Rf{sup *} is the asymptotic fouling resistance, {theta} is time, {theta}d is dead time and {theta}c is the time constant for the asymptotic decay. The values of {theta}c and Rf{sup *} from regression analysis have been correlated with the various parameters by the Heat Transfer Research, Inc., (HTRI) fouling model. For the range of conditions studied, the correlation equations relate the fouling resistance, Rf, to the surface temperature, wall shear stress and water quality. Seventeen different water qualities were investigated to determine the values of 5 parameters, which are specific for each water quality. For each of the seventeen water qualities studied threshold curves for three threshold values of Rf{sup *} have been developed as a function of velocity and surface temperature. These curves are useful to obtain the conditions required to maintain a desired value of Rf{sup *} in a heat exchanger.

  17. Physiological and behavioral basis for the successful adaptation of goats to severe water restriction under hot environmental conditions.

    PubMed

    Kaliber, M; Koluman, N; Silanikove, N

    2016-01-01

    Among domestic ruminants, goats are renowned for their ability to tolerate water deprivation, water restriction and energy restriction. However, some basic questions regarding their ability to endure water restriction under heat stress are still open. Three levels of water restriction (56%, 73% and 87% of the ad libitum) were imposed on 20 cross-bred 3-year-old female goats (75% German Fawn and 25% Hair Goat) distributed into four groups, with five animals per treatment. The experiment was conducted from the beginning of July to the end of August in a farm located in the Eastern Mediterranean region of Turkey (40 m in altitude; 36 59' N, 35 18'E), in which subtropical weather conditions prevail. The average daily temperature during the experiment was 34.2°C, whereas the highest and lowest temperatures were 42°C and 23.1°C, respectively. The average relative humidity was 68.2% and wind speed was 1.2 km/h. Weekly average thermal heat indexes during the experiment were 78.3 (week 1), 79.1 (week 2), 80.1 (weak 3), 79.8 (weak 4), 81.3 (weak 5) and on average 79.7. Feed intake, heart rate, thermoregulatory responses (rectal temperature, respiration rate), blood plasma concentrations of ions (Na, K), antidiuretic hormone (ADH), metabolites (glucose, cholesterol, creatinine and urea) and behavioral aspects (standing, walking, lying) were studied over 30 days. The responses to water restriction were proportional to the level of restriction. The reductions in feed intake (up to 13%), BW (up to 4.6%) and the increases in rectal temperature (0.5°C) and breath rate (10 respirations/min) were moderate and also were far from responses encountered under severe heat and water stresses. The increase in plasma Na (from 119 to 140 mM) and ADH concentrations (from 12.6 to 17.4 pg/ml) indicates that the physiological response to water restriction was in response to mild dehydration, which also explains the increase in blood plasma concentrations of glucose, cholesterol, creatinine and urea. Behavioral responses (reduction in walking from 226 to 209 min/day and increase in lying from 417 to 457 min/day) were associated with conservation of energy or thermoregulation (reducing the exposure to direct radiation). PMID:26256149

  18. [Emission Characteristics of Water-Soluble Ions in Fumes of Coal Fired Boilers in Beijing].

    PubMed

    Hu, Yue-qi; Ma, Zhao-hui; Feng, Ya-jun; Wang, Chen; Chen, Yuan-yuan; He, Ming

    2015-06-01

    Selecting coal fired boilers with typical flue gas desulfurization and dust extraction systems in Beijing as the study objects, the issues and characteristics of the water-soluble ions in fumes of coal fired boilers and theirs influence factors were analyzed and evaluated. The maximum mass concentration of total water-soluble ions in fumes of coal fired boilers in Beijing was 51.240 mg x m(-3) in the benchmark fume oxygen content, the minimum was 7.186 mg x m(-3), and the issues of the water-soluble ions were uncorrelated with the fume moisture content. SO4(2-) was the primary characteristic water-soluble ion for desulfurization reaction, and the rate of contribution of SO4(2-) in total water-soluble ions ranged from 63.8% to 81.0%. F- was another characteristic water-soluble ion in fumes of thermal power plant, and the rate of contribution of F- in total water-soluble ions ranged from 22.2% to 32.5%. The fume purification technologies significantly influenced the issues and the emission characteristics of water-soluble ions in fumes of coal fired boilers. Na+ was a characteristic water-soluble ion for the desulfurizer NaOH, NH4+ and NO3+ were characteristic for the desulfurizer NH4HCO3, and Mg2+ was characteristic for the desulfurizer MgO, but the Ca2+ emission was not increased by addition of the desulfurizer CaO or CaCO3 The concentrations of NH4+ and NO3- in fumes of thermal power plant were lower than those in fumes of industrial or heating coal fired boilers. The form of water-soluble ions was significantly correlated with fume temperature. The most water-soluble ions were in superfine state at higher fume temperature and were not easily captured by the filter membrane. PMID:26387296

  19. Effect of Saline Water Irrigation on Growth and Physiological Responses of Three Rose Rootstocks

    PubMed Central

    Niu, Genhua; Rodriguez, Denise S.; Aguiniga, Lissie

    2009-01-01

    Salt-tolerant landscape plants are needed for arid and semiarid regions where the supply of quality water is limited and soil salinization often occurs. This study evaluated growth, chloride (Cl) and sodium (Na) uptake, relative chlorophyll content, and chlorophyll fluorescence of three rose rootstocks [Rosa ×fortuniana Lindl., R. multiflora Thunb., and R. odorata (Andr.) Sweet] irrigated with saline solutions at 1.6 (control), 3.0, 6.0, or 9.0 dS·m −1 electrical conductivity in a greenhouse. After 15 weeks, most plants in 9.0 dS·m −1 treatment died regardless of rootstock. Significant growth reduction was observed in all rootstocks at 6.0 dS·m −1 compared with the control and 3.0 dS·m −1, but the reduction in R. ×fortuniana was smaller than in the other two rootstocks. The visual scores of R. multiflora at 3.0 and 6.0 dS·m−1 were slightly lower than those of the other rootstocks. Rosa odorata had the highest shoot Na concentration followed by R. multiflora; however, R. multiflora had the highest root Na concentration followed by R. odorata. All rootstocks had higher Cl accumulation in all plant parts at elevated salinities, and no substantial differences in Cl concentrations in all plant parts existed among the rootstocks, except for leaf Cl concentration in R. multiflora, which was higher than those in the other two rootstocks. The elevated salinities of irrigation water reduced the relative chlorophyll concentration, measured as leaf SPAD readings, and maximal photochemical efficiency of photosystem II (PSII) and minimal fluorescence (F0)/maximum fluorescence (Fv/Fm), but the largest reduction in Fv/Fm was only 2.4%. Based on growth and visual quality, R. ×fortuniana was relatively more salt-tolerant than the other two rootstocks and R. odorata was slightly more salt-tolerant than R. multiflora. PMID:20148186

  20. The impact of stress on motor performance in skilled musicians suffering from focal dystonia: Physiological and psychological characteristics.

    PubMed

    Ioannou, Christos I; Furuya, Shinichi; Altenmüller, Eckart

    2016-05-01

    Recent investigations have suggested that stress can modulate motor function. However, the impact of stress on motor performance of musicians suffering from focal dystonia (FDM) remains unknown. The current study assessed motor performance in 20 FDM patients and 16 healthy musicians (HM) before and under stress. Stress was manipulated using the Trier Social Stress Test (TSST). Motor performance was evaluated based on analysis of electromyographic (EMG) activity and temporal variability, while electrocardiography (ECG) and the level of free cortisol were used to test for objective alterations of the hypothalamic-pituitary-adrenal (HPA) axis. Finally, the psychological profiles of both groups were analyzed using three psycho-diagnostic standardized questionnaires. Results showed that patients' motor impairments did not change under acute stressful conditions. However, an increase in muscular co-contractions was observed, reflecting a physiological muscular response under stressful conditions. Psycho-diagnostic analysis revealed higher levels of psychological traits related to elevated anxiety, stress and perfectionism in 40% of the patients. Although the motor outcome between those patients and those with an opposing psychological profile did not differ, patients characterized by stressful and perfectionistic personalities had, on average, developed dystonia about ten years earlier than the rest of the patients. The current study suggests that acute stress conditions may not have any direct impact on fine motor control of FDM patients. However psychological traits associated with increased stress, anxiety and perfectionism may have a long-lasting effect on the motor function of affected musicians, by promoting the acceleration or even the triggering of dystonia. PMID:27033741

  1. Nitrous oxide emission and mitigation from wheat agriculture: association of physiological and anatomical characteristics of wheat genotypes.

    PubMed

    Borah, Leena; Baruah, Kushal Kumar

    2016-01-01

    Agriculture is an important source of emission of the greenhouse gas nitrous oxide (N2O). The observed differences in N2O emission among different varieties of agricultural crops can be a key factor for developing N2O emission reduction strategies. N2O emissions were estimated from three varieties of wheat viz. Sonalika, DBW 39, and K 0307 during 2010-2011 in an attempt to identify plant physiological and anatomical factors contributing to differences in gas emissions within the varieties. Sonalika was identified as a low N2O emitting variety and DBW 39 as high emitting when grown in a uniform field condition. The experiment was repeated in 2011-2012 selecting low emitting Sonalika and high emitting variety DBW 39 for further confirmation of the results obtained during the first year of experimentation. Important plant factors namely rate of photosynthesis and transpiration in flag leaf, stomatal frequency of adaxial flag leaf surface, and size of the xylem vessels (mean vessel size of node, stem, and root) were studied, and their relationship with N2O flux was worked out. A good correlation between transpiration and N2O flux was observed in this study. Scanning electron microscopic investigation revealed strong association of flag leaf stomatal frequency and xylem size with N2O emission. Sonalika, identified as low N2O emitting variety during both the years of study, also recorded higher grain yield due to its higher efficiency of photosynthate allocation toward the developing grains. The observed differences in N2O emission are considered to be due largely to genetic differences in the wheat genotypes. PMID:26335526

  2. Rapid toxicity screening of sediment pore waters using physiological and biochemical biomarkers of Daphnia magna

    SciTech Connect

    Coen, W.M. De; Janssen, C.R.; Persoone, G.

    1995-12-31

    Two new rapid toxicity tests, based on ingestion activity and digestive enzyme activity of D. magna, were developed and evaluated. The ingestion activity was measured using fluorescent latex micro-beads and an automated microplate fluorimeter allowing a sensitive quantification of the feeding activity of the organisms. The activity of the digestive enzymes, 6-galactosidase, esterase and trypsin, was determined in test organism homogenates using the following fluorogenic{sup 1} and chromogenic{sup 2} substrates: 4-methylumbelliferyl-{beta}-D galactoside{sup 1}, fluorescin diacetate{sup 1} and N-Benzoyl-L-arginine-4-nitroanilide{sup 2}. Both biomarker techniques were developed to allow rapid toxicity screening on a routine basis. The toxicity of the pore waters of eight contaminated samples was assessed with the aid of the developed biomarker assays. Comparison of the conventional 24h EC50 values with the EC50 values obtained with the 1.5h ingestion test and the threshold concentrations of the 2h digestive enzyme tests revealed a positive correlation between the different effect concentrations. A similar correlation (r{sup 2} = 0.87) between the conventional 24h EC50 values and 1.5h EC50 values was observed in toxicity tests with pure compounds. Correlation coefficients for the relationships between the 3 enzyme effect concentrations and the 24h EC50 values ranged from 0.95 to 0.98, The positive correlations between the conventional and biomarker effect criteria, observed for both environmental samples and pure compounds, demonstrate the potential use of the developed methods as rapid toxicity screening tools.

  3. Optical characteristics of natural waters protect amphibians from UV-B in the U.S. Pacific Northwest

    USGS Publications Warehouse

    Palen, Wendy J.; Schindler, David E.; Adams, Michael J.; Pearl, Christopher A.; Bury, R. Bruce; Diamond, S.A.

    2002-01-01

    Increased exposure to ultraviolet-B (UV-B) radiation has been proposed as a major environmental stressor leading to global amphibian declines. Prior experimental evidence from the U.S. Pacific Northwest (PNW) indicating the acute embryonic sensitivity of at least four amphibian species to UV-B has been central to the literature about amphibian decline. However, these results have not been expanded to address population-scale effects and natural landscape variation in UV-B transparency of water at amphibian breeding sites: both necessary links to assess the importance of UV-B for amphibian declines. We quantified the UV-B transparency of 136 potential amphibian breeding sites to establish the pattern of UV-B exposure across two montane regions in the PNW. Our data suggest that 85% of sites are naturally protected by dissolved organic matter in pond water, and that only a fraction of breeding sites are expected to experience UV-B intensities exceeding levels associated with elevated egg mortality. Thus, the spectral characteristics of natural waters likely mediate the physiological effects of UV-B on amphibian eggs in all but the clearest waters. These data imply that UV-B is unlikely to cause broad amphibian declines across the landscape of the American Northwest.

  4. MUTAGENIC CHARACTERISTICS OF RIVER WATERS FLOWING THROUGH LARGE METROPOLITAN AREAS IN NORTH AMERICA

    EPA Science Inventory

    Mutagenic characteristics of river waters flowing through large metropolitan areas in North America

    The hanging technique using blue rayon, which specifically adsorbs mutagens with multicyclic planar structures, has the advantages over most conventional methods of not havi...

  5. Toxic Effects of Ethyl Cinnamate on the Photosynthesis and Physiological Characteristics of Chlorella vulgaris Based on Chlorophyll Fluorescence and Flow Cytometry Analysis

    PubMed Central

    Jiao, Yang; Ouyang, Hui-Ling; Jiang, Yu-Jiao; Kong, Xiang-Zhen; He, Wei; Liu, Wen-Xiu; Yang, Bin; Xu, Fu-Liu

    2015-01-01

    The toxic effects of ethyl cinnamate on the photosynthetic and physiological characteristics of Chlorella vulgaris were studied based on chlorophyll fluorescence and flow cytometry analysis. Parameters, including biomass, Fv/Fm (maximal photochemical efficiency of PSII), ФPSII (actual photochemical efficiency of PSII in the light), FDA, and PI staining fluorescence, were measured. The results showed the following: (1) The inhibition on biomass increased as the exposure concentration increased. 1 mg/L ethyl cinnamate was sufficient to reduce the total biomass of C. vulgaris. The 48-h and 72-h EC50 values were 2.07 mg/L (1.94–2.20) and 1.89 mg/L (1.82–1.97). (2) After 24 h of exposure to 2–4 mg/L ethyl cinnamate, the photosynthesis of C. vulgaris almost ceased, manifesting in ФPSII being close to zero. After 72 h of exposure to 4 mg/L ethyl cinnamate, the Fv/Fm of C. vulgaris dropped to zero. (3) Ethyl cinnamate also affected the cellular physiology of C. vulgaris, but these effects resulted in the inhibition of cell yield rather than cell death. Exposure to ethyl cinnamate resulted in decreased esterase activities in C. vulgaris, increased average cell size, and altered intensities of chlorophyll a fluorescence. Overall, esterase activity was the most sensitive variable. PMID:26101784

  6. Mineralogical and geochemical characteristics of drinking water salt deposits

    NASA Astrophysics Data System (ADS)

    Soktoev, B. R.; Rikhvanov, L. P.; Matveenko, I. A.

    2015-11-01

    The article presents the research results on the features of element and mineral composition of salt deposits (limescale) formed in household conditions in heat exchanging equipment. The major part of limescale is represented by two species of calcium carbonate - calcite and aragonite. We have shown that high concentrations of chemical elements in the limescale promote the formation of their own mineral forms (sulphates, silicates, native forms) in salt deposits. Detecting such mineral formations suggests the salt deposits of drinking water to be a long-term storage media which can be used in the course of eco-geochemical and metallogenic studies.

  7. Dipole receiver characteristics in the presence of sea water

    NASA Technical Reports Server (NTRS)

    Kao, P. S.

    1972-01-01

    The receive properties for a dipole in the presence of sea water were obtained by solving integral equations for currents along the unloaded dipole and its image. For dipoles of 0.1 wavelength or higher above the sea surface, the performance resembled that of a dipole over a perfectly conducting plane; for dipoles within 0.1 wavelength above the sea surface, the relative gain dropped in about the same proportion as the relative reduction in the strength of the resultant electric field. An insulated wavelength/2 dipole with a conjugate load matched in free space had a relative power gain of 17 db below isotropic at the sea surface.

  8. Differential physiological and endocrine responses of rainbow trout, Oncorhynchus mykiss, transferred from fresh water to ion-poor or salt water.

    PubMed

    Flores, Anne-Marie; Mark Shrimpton, J

    2012-01-15

    To understand the physiological and molecular endocrine changes that occur in response to a salinity challenge, we transferred rainbow trout from fresh water to an ion-poor or 24‰ saltwater treatment for 14 days. An increase in gill Na(+), K(+)-ATPase (NKA) activity in salt water was associated with higher mRNA expression for the NKA α1b subunit. In contrast, there was little change in gill NKA activity following transfer to ion-poor water, but the mRNA expression of NKA α1a was significantly elevated. Endocrine signals were assessed by measuring plasma cortisol concentrations and by quantifying changes in mRNA extracted from the gill for glucocorticoid receptors 1 and 2 (GR1 and GR2), mineralocorticoid receptor (MR), growth hormone receptor (GHR1), and prolactin receptor (PrlR). Cortisol increased after transfer to ion-poor and salt water, but both GR and MR mRNA in the gill showed little change. PrlR mRNA was significantly higher when fish were transferred to the ion-poor water and GHR1 mRNA was elevated during the saltwater challenge. This study demonstrated an increase in gill PrlR mRNA that parallels the changes in gill NKA α1a when rainbow trout were transferred to a lower salinity level. Furthermore, the increase in gill GHR1 mRNA supports the importance of GH for seawater acclimation as there is a corresponding increase in the expression of gill NKA α1b, the saltwater isoform. GH and Prl, therefore, may differentially determine the function of cortisol in both fresh- and saltwater ionoregulation. PMID:22137911

  9. Oral physiology and mastication.

    PubMed

    van der Bilt, A; Engelen, L; Pereira, L J; van der Glas, H W; Abbink, J H

    2006-08-30

    Mastication is a sensory-motor activity aimed at the preparation of food for swallowing. It is a complex process involving activities of the facial, the elevator and suprahyoidal muscles, and the tongue. These activities result in patterns of rhythmic mandibular movements, food manipulation and the crushing of food between the teeth. Saliva facilitates mastication, moistens the food particles, makes a bolus, and assists swallowing. The movement of the jaw, and thus the neuromuscular control of chewing, plays an important role in the comminution of the food. Characteristics of the food, e.g. water and fat percentage and hardness, are known to influence the masticatory process. Food hardness is sensed during mastication and affects masticatory force, jaw muscle activity, and mandibular jaw movements. When we chew for instance a crispy food, the jaw decelerates and accelerates as a result of resistance and breakage of food particles. The characteristic breakage behaviour of food is essential for the sensory sensation. This study presents a short review of the influence of oral physiology characteristics and food characteristics on the masticatory process. PMID:16564557

  10. Genotypic Variation in Growth and Physiological Response to Drought Stress and Re-Watering Reveals the Critical Role of Recovery in Drought Adaptation in Maize Seedlings

    PubMed Central

    Chen, Daoqian; Wang, Shiwen; Cao, Beibei; Cao, Dan; Leng, Guohui; Li, Hongbing; Yin, Lina; Shan, Lun; Deng, Xiping

    2016-01-01

    Non-irrigated crops in temperate climates and irrigated crops in arid climates are subjected to continuous cycles of water stress and re-watering. Thus, fast and efficient recovery from water stress may be among the key determinants of plant drought adaptation. The present study was designed to comparatively analyze the roles of drought resistance and drought recovery in drought adaptation and to investigate the physiological basis of genotypic variation in drought adaptation in maize (Zea mays) seedlings. As the seedlings behavior in growth associate with yield under drought, it could partly reflect the potential of drought adaptability. Growth and physiological responses to progressive drought stress and recovery were observed in seedlings of 10 maize lines. The results showed that drought adaptability is closely related to drought recovery (r = 0.714**), but not to drought resistance (r = 0.332). Drought induced decreases in leaf water content, water potential, osmotic potential, gas exchange parameters, chlorophyll content, Fv/Fm and nitrogen content, and increased H2O2 accumulation and lipid peroxidation. After recovery, most of these physiological parameters rapidly returned to normal levels. The physiological responses varied between lines. Further correlation analysis indicated that the physiological bases of drought resistance and drought recovery are definitely different, and that maintaining higher chlorophyll content (r = 0.874***) and Fv/Fm (r = 0.626*) under drought stress contributes to drought recovery. Our results suggest that both drought resistance and recovery are key determinants of plant drought adaptation, and that drought recovery may play a more important role than previously thought. In addition, leaf water potential, chlorophyll content and Fv/Fm could be used as efficient reference indicators in the selection of drought-adaptive genotypes. PMID:26793218

  11. Development Characteristics of PMMA in alternative alcohol:water mixtures

    NASA Astrophysics Data System (ADS)

    Ocola, Leonidas E.

    2015-03-01

    The most widely used resist in electron beam lithography is polymethylmethacrylate (PMMA). The standard developers used are solution mixtures of isopropanol (IPA) and methyl isobutyl ketone (MIBK) in a ratio of 3:1 and mixtures of IPA and water (H2O) in a ratio of 7:3. The Globally Harmonized System (GHS) classification entry for IPA includes: Specific target organ toxicity - single exposure (Category 3). MIBK is much more hazardous than IPA. The only GHS classification entry for Ethanol is: Flammable liquids (Category 2), i.e. more environmentally safe. Using Ethanol/H2O as a developer will therefore enable lower hazardous waste disposal costs to cleanrooms. We find Ethanol/H2O at 85% volume (2:1 molar) exhibits excellent lithography results as good as with IPA/H2O, and better contrast and sensitivity than IPA/H2O and MIBK/IPA developers. Lithographic data shows trends similar to published cosolvency data, but differ too much to be explained by it. In addition, unusual development at 50% volume concentrations for both IPA and Ethanol in H2O show dramatic pothole formation instead of uniform thickness loss found in standard contrast curve exposures. We believe local pockets of concentrated alcohol water molar mixtures are responsible for such behavior. This work was supported by the Department of Energy under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  12. Survey of receiving-water environmental impacts associated with discharges from pulp mills; 1: Mill characteristics, receiving-water chemical profiles and lab toxicity tests

    SciTech Connect

    Robinson, R.D. . Dept. of Environmental Biology); Carey, J.H. . Rivers Research Branch); Solomon, K.R. ); Smith, I.R. . Water Resources Branch); Servos, M.R.; Munkittrick, K.R. . Great Lakes Lab. for Fisheries and Aquatic Sciences)

    1994-07-01

    This survey examined the relationship between environmental responses at pulp mill sites and the pulping process, effluent treatment, and bleaching technology used by pulp mills. This manuscript is the first in a series of four; it reviews the location and operating characteristics of mills included in the survey and provides background information on water chemistry that is relevant to the other components of the survey. In addition, lab 7-d toxicity tests of receiving water were conducted using fathead minnows (Pimephales promelas) and the cladoceran Ceriodaphnia dubia with water samples collected upstream and downstream of effluent discharges at 11 Canadian pulp and paper mills; these samples were collected at the same time as fish surveys were conducted. Survival of fathead minnow larvae was significantly reduced at four of the 11 downstream sites. Ceriodaphnia reproduction was significantly higher at six of the 11 downstream sites and significantly lower at two downstream sites. There were no significant effects on fathead minnow larva growth or adult Ceriodaphnia survival at any of the examined downstream sites. Negative effects in the toxicity tests were generally associated with the low dilution discharge of primary treated effluent with a previous history of acute toxicity. Fathead minnow and Ceriodaphnia tests were generally correlated with historical data on benthic macroinvertebrate community responses. Neither toxicity test predicted the physiological changes in wild fish that are presented in accompanying papers.

  13. A comparison of physiological and transcriptome responses to water deprivation and salt loading in the rat supraoptic nucleus.

    PubMed

    Greenwood, Michael P; Mecawi, Andre S; Hoe, See Ziau; Mustafa, Mohd Rais; Johnson, Kory R; Al-Mahmoud, Ghada A; Elias, Lucila L K; Paton, Julian F R; Antunes-Rodrigues, Jose; Gainer, Harold; Murphy, David; Hindmarch, Charles C T

    2015-04-01

    Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, arginine vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. On osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function-related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared with euhydrated (EU) controls in terms of drinking and eating behavior, body weight, and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL and remined data from the SON that describes the transcriptome response to WD. From a list of 2,783 commonly regulated transcripts, we selected 20 genes for validation by qPCR. All of the 9 genes that have already been described as expressed or regulated in the SON by osmotic stimuli were confirmed in our models. Of the 11 novel genes, 5 were successfully validated while 6 were false discoveries. PMID:25632023

  14. Genotype–environment interactions affecting preflowering physiological and morphological traits of Brassica rapa grown in two watering regimes

    PubMed Central

    Aarts, Mark G. M.

    2014-01-01

    Plant growth and productivity are greatly affected by drought, which is likely to become more threatening with the predicted global temperature increase. Understanding the genetic architecture of complex quantitative traits and their interaction with water availability may lead to improved crop adaptation to a wide range of environments. Here, the genetic basis of 20 physiological and morphological traits is explored by describing plant performance and growth in a Brassica rapa recombinant inbred line (RIL) population grown on a sandy substrate supplemented with nutrient solution, under control and drought conditions. Altogether, 54 quantitative trait loci (QTL) were identified, of which many colocated in 11 QTL clusters. Seventeen QTL showed significant QTL–environment interaction (Q×E), indicating genetic variation for phenotypic plasticity. Of the measured traits, only hypocotyl length did not show significant genotype–environment interaction (G×E) in both environments in all experiments. Correlation analysis showed that, in the control environment, stomatal conductance was positively correlated with total leaf dry weight (DW) and aboveground DW, whereas in the drought environment, stomatal conductance showed a significant negative correlation with total leaf DW and aboveground DW. This correlation was explained by antagonistic fitness effects in the drought environment, controlled by a QTL cluster on chromosome A7. These results demonstrate that Q×E is an important component of the genetic variance and can play a great role in improving drought tolerance in future breeding programmes. PMID:24474811

  15. Release of glycosaminoglycans in physiological saline and water by wet-spun chitin--acid glycosaminoglycan fibers.

    PubMed

    Hirano, S; Zhang, M; Nakagawa, M

    2001-09-15

    The present study sought to prepare novel chitin- acid glycosaminoglycan fibers that released a portion of the glycosaminoglycans in animal body fluids for use as novel biocompatible dressing materials (artificial skin) in the veterinary and clinical fields. A clear solution of sodium N-acetylchitosan salt (alkaline chitin) mixed with sodium hyaluronate, sodium heparin, sodium chondroitin 4-sulfate, sodium chondroitin 6-sulfate, or sodium dermatan sulfate in 14% aqueous NaOH was spun through a viscose-type spinneret into a 10% aqueous H(2)SO(4) solution saturated with (NH(4))(2)SO(4) at room temperature. The result was chitin fibers containing 5--33% glycosaminoglycans. In a dry state these fibers were white and had a soft feel but they were mechanically weak (0.31--0.69 g/denier tenacity and 3.1--10.6% elongation). Portions (85--97%) of the glycosaminoglycans were released from the fibers by soaking them in physiological saline or distilled water. Scanning electron microscopy analyses revealed a smooth striped surface on the original filaments, and a scaly surface appeared on the chitin filament after soaking. PMID:11400133

  16. Genotype-environment interactions affecting preflowering physiological and morphological traits of Brassica rapa grown in two watering regimes.

    PubMed

    El-Soda, Mohamed; Boer, Martin P; Bagheri, Hedayat; Hanhart, Corrie J; Koornneef, Maarten; Aarts, Mark G M

    2014-02-01

    Plant growth and productivity are greatly affected by drought, which is likely to become more threatening with the predicted global temperature increase. Understanding the genetic architecture of complex quantitative traits and their interaction with water availability may lead to improved crop adaptation to a wide range of environments. Here, the genetic basis of 20 physiological and morphological traits is explored by describing plant performance and growth in a Brassica rapa recombinant inbred line (RIL) population grown on a sandy substrate supplemented with nutrient solution, under control and drought conditions. Altogether, 54 quantitative trait loci (QTL) were identified, of which many colocated in 11 QTL clusters. Seventeen QTL showed significant QTL-environment interaction (QE), indicating genetic variation for phenotypic plasticity. Of the measured traits, only hypocotyl length did not show significant genotype-environment interaction (GE) in both environments in all experiments. Correlation analysis showed that, in the control environment, stomatal conductance was positively correlated with total leaf dry weight (DW) and aboveground DW, whereas in the drought environment, stomatal conductance showed a significant negative correlation with total leaf DW and aboveground DW. This correlation was explained by antagonistic fitness effects in the drought environment, controlled by a QTL cluster on chromosome A7. These results demonstrate that QE is an important component of the genetic variance and can play a great role in improving drought tolerance in future breeding programmes. PMID:24474811

  17. A comparison of physiological and transcriptome responses to water deprivation and salt loading in the rat supraoptic nucleus

    PubMed Central

    Greenwood, Michael P.; Mecawi, Andre S.; Hoe, See Ziau; Mustafa, Mohd Rais; Johnson, Kory R.; Al-Mahmoud, Ghada A.; Elias, Lucila L. K.; Paton, Julian F. R.; Antunes-Rodrigues, Jose; Gainer, Harold; Murphy, David

    2015-01-01

    Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, arginine vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. On osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function-related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared with euhydrated (EU) controls in terms of drinking and eating behavior, body weight, and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL and remined data from the SON that describes the transcriptome response to WD. From a list of 2,783 commonly regulated transcripts, we selected 20 genes for validation by qPCR. All of the 9 genes that have already been described as expressed or regulated in the SON by osmotic stimuli were confirmed in our models. Of the 11 novel genes, 5 were successfully validated while 6 were false discoveries. PMID:25632023

  18. Trends in selected water-quality characteristics, Powder River and tributaries, Montana and Wyoming, water years 1968-88 and 1975-88. Water Resources Investigation

    SciTech Connect

    Cary, L.E.

    1991-04-01

    The report describes the methods of analysis and the trends detected in water quality of the Powder River and its major tributaries. Sites for study were selected from all combination streamflow-gaging and water-quality stations in the basin on the basis of length of record and total number of samples. The relative sodium concentration and the salinity of streamflow of the Powder River were of primary interest, owing to the effects of those characteristics on the suitability of the water for irrigation. Therefore, water-quality characteristics that contributed most to relative sodium concentration and salinity were selected for study.

  19. Water clarity, maternal behavior, and physiology combine to eliminate UV radiation risk to amphibians in a montane landscape

    PubMed Central

    Palen, Wendy J.; Schindler, Daniel E.

    2010-01-01

    Increasing UV-B radiation (UV-B; 290–320 nm) due to stratospheric ozone depletion has been a leading explanation for the decline in amphibians for nearly 2 decades. Yet, the likelihood that UV-B can influence amphibians at the large spatial scales relevant to population declines has not yet been evaluated. A key limitation has been in relating results from individual sites to the effect of UV-B for populations distributed across heterogeneous landscapes. We measured critical embryonic exposures to UV-B for two species of montane amphibians with contrasting physiological sensitivities, long-toed salamander (Ambystoma macrodactylum) and Cascades frog (Rana cascadae), at field sites spanning a gradient of UV-B attenuation in water. We then used these experimental results to estimate the proportion of embryos exposed to harmful UV-B across a large number of breeding sites. By combining surveys of the incubation timing, incident UV-B, optical transparency of water, and oviposition depth and light exposure of embryos at each site, we present a comprehensive assessment of the risk posed by UV-B for montane amphibians of the Pacific Northwest. We found that only 1.1% of A. macrodactylum and no R. cascadae embryos across a landscape of breeding sites are exposed to UV-B exceeding lethal levels. These results emphasize that accurately estimating the risk posed by environmental stressors requires placing experimental results in a broader ecological context that accounts for the heterogeneity experienced by populations distributed across natural landscapes. PMID:20479221

  20. Carbon and water flux responses to physiology by environment interactions: a sensitivity analysis of variation in climate on photosynthetic and stomatal parameters

    NASA Astrophysics Data System (ADS)

    Bauerle, William L.; Daniels, Alex B.; Barnard, David M.

    2014-05-01

    Sensitivity of carbon uptake and water use estimates to changes in physiology was determined with a coupled photosynthesis and stomatal conductance ( g s) model, linked to canopy microclimate with a spatially explicit scheme (MAESTRA). The sensitivity analyses were conducted over the range of intraspecific physiology parameter variation observed for Acer rubrum L. and temperate hardwood C3 (C3) vegetation across the following climate conditions: carbon dioxide concentration 200-700 ppm, photosynthetically active radiation 50-2,000 μmol m-2 s-1, air temperature 5-40 °C, relative humidity 5-95 %, and wind speed at the top of the canopy 1-10 m s-1. Five key physiological inputs [quantum yield of electron transport ( α), minimum stomatal conductance ( g 0), stomatal sensitivity to the marginal water cost of carbon gain ( g 1), maximum rate of electron transport ( J max), and maximum carboxylation rate of Rubisco ( V cmax)] changed carbon and water flux estimates ≥15 % in response to climate gradients; variation in α, J max, and V cmax input resulted in up to ~50 and 82 % intraspecific and C3 photosynthesis estimate output differences respectively. Transpiration estimates were affected up to ~46 and 147 % by differences in intraspecific and C3 g 1 and g 0 values—two parameters previously overlooked in modeling land-atmosphere carbon and water exchange. We show that a variable environment, within a canopy or along a climate gradient, changes the spatial parameter effects of g 0, g 1, α, J max, and V cmax in photosynthesis- g s models. Since variation in physiology parameter input effects are dependent on climate, this approach can be used to assess the geographical importance of key physiology model inputs when estimating large scale carbon and water exchange.

  1. Physiological and morphological characteristics of periodontal mesencephalic trigeminal neurons in the cat--intra-axonal staining with HRP.

    PubMed

    Shigenaga, Y; Doe, K; Suemune, S; Mitsuhiro, Y; Tsuru, K; Otani, K; Shirana, Y; Hosoi, M; Yoshida, A; Kagawa, K

    1989-12-25

    Intra-axonal recording and horseradish peroxidase (HRP) injection techniques were employed to define the response properties of periodontal mechanoreceptive afferents originating from the trigeminal mesencephalic nucleus (Vmes) and their morphological characteristics. The periodontal Vmes neurons were classified into two types: slowly adapting (SA) and fast adapting (FA) types. The central terminals of 7 SA and 4 FA afferents were recovered for detailed analyses. The whole profile of SA and FA neurons were unipolar in shape and their cell bodies were located in the dorsomedial parts of the Vmes. The united (U) fiber traveled caudally from the soma to the dorsolateral aspect of the trigeminal motor nucleus (Vmo), where it split into the peripheral (P) and C fibers with a T- or Y-shaped appearance. The P fiber joined the trigeminal sensory or motor tract. The C fiber descended caudally within Probst's tract. All 3 stem fibers issued main collaterals. The main collaterals of all neurons examined formed terminal arbors in the supratrigeminal nucleus (Vsup) and all but two SA neurons projected to the intertrigeminal region (Vint), while the projections to other nuclei of the trigeminal motor nucleus (Vmo), juxtatrigeminal region (Vjux), main sensory nucleus (Vp) and oral nucleus (Vo.r) differed between SA and FA afferents and between neurons of the same type. The SA and FA neurons were classified into three and two subgroups, respectively. The major differences in central projections between the two types were that all the FA neurons projected to the Vp or Vo.r but none of SA type and this relation was reversed in the projection to the Vjux, and that more than half of SA neurons projected to Vmo but only one FA neuron to the Vmo. The Vmes neurons which sent their collaterals into the Vmo had the P fiber passing through the tract of the trigeminal motor nerve. The average size of somata and mean diameters of U fibers and main collaterals from C fiber were significantly larger in SA neurons than FA neurons. The average size of fiber varicosities became smaller in the following nuclei, Vmo, Vsup, Vp, Vint and Vo.r, but not significant between the two functional types. The functional role of the periodontal Vmes afferents to jaw reflexes was discussed particularly with respect to their central projection sites in the brainstem nuclei. PMID:2611682

  2. Agrichemicals in ground water of the midwestern USA: Relations to soil characteristics

    USGS Publications Warehouse

    Burkart, M.R.; Kolpin, D.W.; Jaquis, R.J.; Cole, K.J.

    1999-01-01

    A comprehensive set of soil characteristics were examined to determine the effect of soil on the transport of agrichemicals to ground water. This paper examines the relation of local soil characteristics to concentrations and occurrence of nitrate, atrazine (2-chloro-4 ethylamino-6-isopropylamino-s-trazine), and atrazine residue [atrazine + deethylatrazine (2-amino-4-chloro-6-isopropylamino-s-triazine) + deisopropylatrazine (2-amino-4-chloro-6-ethylamino-s-triazine)] from 99 wells completed in unconsolidated aquifers across the midwestern USA. The occurrence and concentrations of nitrate and atrazine in ground water were directly related to soil characteristics that determine the rate of water movement. The substantial differences in the relations found among soil characteristics and nitrate and atrazine in ground water suggest that different processes affect the transformation, adsorption, and transport of these contaminants. A multivariate analysis determined that the soil characteristics examined explained the amount of variability in concentrations for nitrate (19.0%), atrazine (33.4%), and atrazine residue (28.6%). These results document that, although soils do affect the transport of agrichemicals to ground water, other factors such as hydrology, land use, and climate must also be considered to understand the occurrence of agrichemicals in ground water.

  3. Still too hot: examination of water temperature and water heater characteristics 24 years after manufacturers adopt voluntary temperature setting.

    PubMed

    Shields, Wendy C; McDonald, Eileen; Frattaroli, Shannon; Perry, Elise C; Zhu, Jeffrey; Gielen, Andrea C

    2013-01-01

    Although water heater manufacturers adopted a voluntary standard in the 1980s to preset thermostats on new water heaters to 120°F, tap water scald burns cause an estimated 1500 hospital admissions and 100 deaths per year in the United States. This study reports on water temperatures in 976 urban homes and identifies water heater and household characteristics associated with having safe temperatures. The temperature of the hot water, type and size of water heater, date of manufacture, and the setting of the temperature gauge were recorded. Demographic data, including number of people living in the home and home ownership, were also recorded. Hot water temperature was unsafe in 41% of homes. Homeowners were more likely to have safer hot water temperature (<120°F) than renters (63 vs 54%; P < .01). For 11% of gas water heaters, the water temperature was >130°F, although the gauge was set at less than 75% of its maximum setting. In a multivariate logistic regression, electric water heaters were more likely to have safe hot water temperatures than gas water heaters (odds ratio R=4.99; P < .01). Water heaters with more gallons per person in the household were more likely to be at or below the recommended 120°F. Our results suggest that hot water temperatures remain dangerously high for a substantial proportion of urban homes despite the adoption of voluntary standards to preset temperature settings by manufacturers. This research highlights the need for improved prevention strategies, such as installing thermostatic mixing valves, to ensure a safer temperature. PMID:23514986

  4. Land use, water use, streamflow characteristics, and water-quality characteristics of the Charlotte Harbor inflow area, Florida

    USGS Publications Warehouse

    Hammett, K.M.

    1990-01-01

    Charlotte Harbor is a 270-square-mile estuarine system in west-central Florida. It is being subjected to increasing environmental stress by rapid population growth and development. By 2020, population in the inflow area may double, which will result in increased demands for freshwater and increased waste loads. The Charlotte Harbor inflow area includes about 4,685 square miles. The Myakka, the Peace, and the Caloosahatchee are the major rivers emptying into the harbor. About 70 percent of the land in these three river basins is used for agriculture and range. In the coastal basin around Charlotte Harbor, about 50 percent of the total land area is devoted to commercial or residential uses. Water use in the inflow area is about 565 million gallons per day, of which 59 percent is used for irrigation, 26 percent for industry, 11 percent for public supply, and 4 percent for rural supply. Total freshwater inflow from the three major rivers, the coastal area, and rainfall directly into Charlotte Harbor averages between 5,700 and 6,100 cubic feet per second, which is more than 3,500 million gallons per day. A trend analysis of about 50 years of streamflow data shows a statistically significant decreasing trend for the Peace River stations at Bartow, Zolfo Springs, and Arcadia. No significant trend has been observed in the Myakka or the Caloosahatchee River data. In the Peace River, the decrease in flow may be related to a long-term decline in the potentiometric surface of the underlying Floridan aquifer system, which resulted from ground-water withdrawals. It is not possible to determine whether the trend will continue. However, if it does continue at the same rate, then, except for brief periods of storm runoff, the Peace River at Zolfo Springs could be dry year-round in about 100 years. Of the 114 facilities permitted to discharge domestic or industrial effluent to waters tributary to Charlotte Harbor, 88 are in the Peace River basin. Phosphate ore and citrus processing account for most of the industrial effluent. Several locations in the headwaters of the Peace River have been significantly affected as a result of receiving wastewater effluent. The Peace, the Myakka, and the Caloosahatchee Rivers transport more than 2,000 tons per day of dissolved solids, more than 17 tons per day of nitrogen, and about 6 tons per day of phosphorus. By 2020, the population in the inflow area is expected to increase by more than 500,000 people. They will require an additional 76 million gallons per day for water supply. The increased population will produce an additional 60 million gallons per day of domestic wastewater, which could result in an additional 3 tons per day of nitrogen and 0.65 ton per day of phosphorus. More than 150 square miles of land will be converted to urban uses, which will produce another 0.25 ton per day of nitrogen from urban runoff. These increased nutrient loads can be expected to occur concurrently with decreased freshwater inflow.

  5. Geospatial variation of grapevine water status, soil water availability, grape composition and sensory characteristics in a spatially heterogeneous premium wine grape vineyard

    NASA Astrophysics Data System (ADS)

    Smart, D. R.; Cosby Hess, S.; Plant, R.; Feihn, O.; Heymann, H.; Ebeler, S.

    2014-11-01

    The geoscience component of terroir in wine grape production continues to be criticized for its quasi-mystical nature, and lack of testable hypotheses. Nonetheless, recent relational investigations are emerging and most involve water availability as captured by available water capacity (AWC, texture) or plant available water (PAW) in the root zone of soil as being a key factor. The second finding emerging may be that the degree of microscale variability in PAW and other soil factors at the vineyard scale renders larger regional characterizations questionable. Cimatic variables like temperature are well mixed, and its influence on wine characteristic is fairly well established. The influence of mesogeology on mesoclimate factors has also been characterized to some extent. To test the hypothesis that vine water status mirrors soil water availability, and controls fruit sensory and chemical properties at the vineyard scale we examined such variables in a iconic, selectively harvested premium winegrape vineyard in the Napa Valley of California during 2007 and 2008 growing seasons. Geo-referenced data vines remained as individual study units throughout data gathering and analysis. Cartographic exercises using geographic information systems (GIS) were used to vizualize geospatial variation in soil and vine properties. Highly significant correlations (P < 0.01) emerged for pre-dawn leaf water potential (ΨPD), mid-day leaf water potential (ΨL) and PAW, with berry size, berry weight, pruning weights (canopy size) and soluble solids content (°Brix). Areas yielding grapes with perceived higher quality had vines with (1) lower leaf water potential (LWP) both pre-dawn and mid-day, (2) smaller berry diameter and weight, (3) lower pruning weights, and (4) higher °Brix. A trained sensory panel found grapes from the more water-stressed vines had significantly sweeter and softer pulp, absence of vegetal character, and browner and crunchier seeds. Metabolomic analysis of the grape skins showed significant differences in accumulation of amino acids and organic acids. Data vines were categorized as non-stressed (ΨPD ≥ -7.9 bars and ΨL ≥ -14.9 bars) and stressed (ΨPD ≤ -8.0 bars and ΨL ≤ -15.0 bars) and subjected to analysis of variance. Significant separation emerged for vines categorized as non-stressed versus stressed at véraison, which correlated to the areas described as producing higher and lower quality fruit. This report does not advocate the use of stress levels herein reported. The vineyard was planted to a vigorous, deep rooted rootstock (V. rupestris cv. St. George), and from years of management is known to be able to withstand stress levels of the magnitude we observed. Nonetheless, the results may suggest there is not a linear relationship between physiological water stress and grape sensory characteristics, but rather the presence of an inflection point controlling grape composition as well as physiological development.

  6. Hydrogeologic characteristics of four public drinking-water supply springs in northern Arkansas

    USGS Publications Warehouse

    Galloway, Joel M.

    2004-01-01

    In October 2000, a study was undertaken by the U.S. Geological Survey (USGS) in cooperation with the Arkansas Department of Health to determine the hydrogeologic characteristics, including the extent of the recharge areas, for Hughes Spring, Stark Spring, Evening Shade Spring, and Roaring Spring, which are used for public-water supply in northern Arkansas. Information pertaining to each spring can be used to enable development of effective management plans to protect these water resources and public health. An integrated approach to determine the ground-water characteristics and the extent of the local recharge areas of the four springs incorporated tools and methods of hydrology, structural geology, geomorphology, geophysics, and geochemistry. Analyses of discharge, temperature, and water quality were completed to describe ground-water flow characteristics, source-water characteristics, and connectivity of the ground-water system with surface runoff. Water-level contour maps were constructed to determine ground-water flow directions and ground-water tracer tests were conducted to determine the extent of the recharge areas and ground-water flow velocities. Hughes Spring supplies water for the city of Marshall, Arkansas, and the surrounding area. The mean annual discharge for Hughes Spring was 2.9 and 5.2 cubic feet per second for water years 2001 and 2002, respectively. Recharge to the spring occurs mainly from the Boone Formation (Springfield Plateau aquifer). Ground-water tracer tests indicate the recharge area for Hughes Spring generally coincides with the surface drainage area (15.8 square miles) and that Hughes Spring is connected directly to the surface flow in Brush Creek. The geochemistry of Hughes Spring demonstrated variations with flow conditions and the influence of surface-runoff in the recharge area. Calcite saturation indices, total dissolved solids concentrations, and hardness demonstrate noticeable differences with flow conditions reflecting the reduced residence time and interaction of water with the source rock within the ground-water system at higher discharges for Hughes Spring. Concentrations of fecal indicator bacteria also demonstrated a substantial increase during high-flow conditions, suggesting that a non-point source of bacteria possibly from livestock may enter the system. Conversely, nutrient concentrations did not vary with flow and were similar to concentrations reported for undeveloped sites in the Springfield Plateau and Ozark aquifers in northern Arkansas and southern Missouri. Deuterium and oxygen-18 data show that the Hughes Spring discharge is representative of direct precipitation and not influenced by water enriched in oxygen-18 through evaporation. Discharge data show that Hughes Spring is dominated by conduit type ground-water flow, but a considerable component of diffuse flow also exists in the ground-water system. Carbon-13 data indicate a substantial component of the recharge water interacts with the surface material (soil and regolith) in the recharge area before entering the ground-water system for Hughes Spring. Tritium data for Hughes Spring indicate that the discharge water is a mixture of recent recharge and sub-modern water (recharged prior to 1952). Stark Spring supplies water for the city of Cushman, Arkansas, and the surrounding area. 2 Hydrogeologic Characteristics of Four Public Drinking-Water Supply Springs in Northern Arkansas The mean annual discharge for Stark Spring was 0.5 and 1.5 cubic feet per second for water years 2001 and 2002, respectively. The discharge and water-quality data show the ground-water system for Stark Spring is dominated by rapid recharge from surface runoff and mainly consists of a conduit- type flow system with little diffuse-type flow. Analyses of discharge data show that the estimated recharge area (0.79 square mile) is larger than the surface drainage area (0.34 square mile). Ground-water tracer tests and the outcrop of the

  7. Climate variability and deep water mass characteristics in the Aegean Sea

    NASA Astrophysics Data System (ADS)

    Georgiou, S.; Mantziafou, A.; Sofianos, S.; Gertman, I.; Özsoy, E.; Somot, S.; Vervatis, V.

    2015-01-01

    The main objective of this study is to investigate the variability of the thermohaline characteristics of the deep-water masses in the Aegean Sea and the possible impact of the regional atmospheric forcing variability by analyzing the available oceanographic and atmospheric datasets for the period of 1960-2012. During this period the variability of the deep water characteristics of the Aegean sub-basins is found to be very large as well as the diversity of the deep water characteristics among the sub-basins. The Central Aegean seems to play the key role in the Aegean deep water formation processes. Due to its small size, the Aegean Sea surface responds rapidly to the meteorological changes and/or the variability of the lateral fluxes and this variability propagates in the thermohaline characteristics of the deep water masses of the basin through deep water formation processes. There are many episodes characterized by a tight coupling of the atmosphere and the ocean during the examined period, with the Eastern Mediterranean Transient (EMT) being the most prominent case. We suggest that deep water formation is triggered mostly by the combination of preconditioning during early winter and/or previous winters together with the number of subsequent extreme events during present winter and not only by the total amount of the extreme heat loss winter days.

  8. Hydrochemical characteristics and water quality assessment of surface water and groundwater in Songnen plain, Northeast China.

    PubMed

    Zhang, Bing; Song, Xianfang; Zhang, Yinghua; Han, Dongmei; Tang, Changyuan; Yu, Yilei; Ma, Ying

    2012-05-15

    Water quality is the critical factor that influence on human health and quantity and quality of grain production in semi-humid and semi-arid area. Songnen plain is one of the grain bases in China, as well as one of the three major distribution regions of soda saline-alkali soil in the world. To assess the water quality, surface water and groundwater were sampled and analyzed by fuzzy membership analysis and multivariate statistics. The surface water were gather into class I, IV and V, while groundwater were grouped as class I, II, III and V by fuzzy membership analysis. The water samples were grouped into four categories according to irrigation water quality assessment diagrams of USDA. Most water samples distributed in category C1-S1, C2-S2 and C3-S3. Three groups were generated from hierarchical cluster analysis. Four principal components were extracted from principal component analysis. The indicators to water quality assessment were Na, HCO(3), NO(3), Fe, Mn and EC from principal component analysis. We conclude that surface water and shallow groundwater are suitable for irrigation, the reservoir and deep groundwater in upstream are the resources for drinking. The water for drinking should remove of the naturally occurring ions of Fe and Mn. The control of sodium and salinity hazard is required for irrigation. The integrated management of surface water and groundwater for drinking and irrigation is to solve the water issues. PMID:22417739

  9. [Spatial Variability Characteristics of Water Quality and Its Driving Forces in Honghu Lake During High Water-level Period].

    PubMed

    Li, Kun; Wang, Ling; Li, Zhao-hua; Wang, Xiang-rong; Chen, Hong-bing; Wu, Zhong; Zhu, Peng

    2015-04-01

    Based on the high-density analysis of 139 monitoring points and samples in water of honghu lake with different degrees of eutrophication during the high water-level period, we could get the figures of spatial variability characteristics of pollution factors, the biomass of aquatic plants and water quality in Honghu Lake using the GIS interpolation methods. The result showed that the concentrations of TN, TP, NH4(+) -N, permanganate index gradually increased from south to north during this period, the trend of water pollution degree in Honghu Lake was the region of inflowing rivers > enclosure culture area > open water area > the lake protection area > region of the Yangtze river into the lake; and the contribution rate of water quality parameters was in the order of TN > TP > permanganate index > NH4(+), -N > DO; under the influence of industrial sewage, agricultural sewage, domestic sewage, bait, aquatic plants and water exchange, 59% of TN, 35.2% of TP, 13.7% of permanganate index, 4.3% of NH4(+)-N exceeded the water quality targets, respectively, accordingly, 66.2% of the water quality also exceeded the water quality target. Nonetheless, DO reached the water quality target due to the influences of monsoon climate and other environment factors. The spatial variation analysis could directly reflect the mutual interaction among human activity, land-use types and environment factors which had an enormous impact on Honghu Lake water environment. In order to ensure that the lake water environment is beneficial for human productions and livings, it is necessary for us to control the discharge of industrial sewage, agricultural sewage and domestic sewage, as well as the expanding area of aquaculture, all the above measures would be significant for gradually resuming the self-purification capacity of water body and finally achieving the ecological sustainable development of Honghu Lake water environment. PMID:26164902

  10. Tropine forming tropinone reductase gene from Withania somnifera (Ashwagandha): biochemical characteristics of the recombinant enzyme and novel physiological overtones of tissue-wide gene expression patterns.

    PubMed

    Kushwaha, Amit Kumar; Sangwan, Neelam Singh; Trivedi, Prabodh Kumar; Negi, Arvind Singh; Misra, Laxminarain; Sangwan, Rajender Singh

    2013-01-01

    Withania somnifera is one of the most reputed medicinal plants of Indian systems of medicine synthesizing diverse types of secondary metabolites such as withanolides, alkaloids, withanamides etc. Present study comprises cloning and E. coli over-expression of a tropinone reductase gene (WsTR-I) from W. somnifera, and elucidation of biochemical characteristics and physiological role of tropinone reductase enzyme in tropane alkaloid biosynthesis in aerial tissues of the plant. The recombinant enzyme was demonstrated to catalyze NADPH-dependent tropinone to tropine conversion step in tropane metabolism, through TLC, GC and GC-MS-MS analyses of the reaction product. The functionally active homodimeric ~60 kDa enzyme catalyzed the reaction in reversible manner at optimum pH 6.7. Catalytic kinetics of the enzyme favoured its forward reaction (tropine formation). Comparative 3-D models of landscape of the enzyme active site contours and tropinone binding site were also developed. Tissue-wide and ontogenic stage-wise assessment of WsTR-I transcript levels revealed constitutive expression of the gene with relatively lower abundance in berries and young leaves. The tissue profiles of WsTR-I expression matched those of tropine levels. The data suggest that, in W. somnifera, aerial tissues as well possess tropane alkaloid biosynthetic competence. In vivo feeding of U-[(14)C]-sucrose to orphan shoot (twigs) and [(14)C]-chasing revealed substantial radiolabel incorporation in tropinone and tropine, confirming the de novo synthesizing ability of the aerial tissues. This inherent independent ability heralds a conceptual novelty in the backdrop of classical view that these tissues acquire the alkaloids through transportation from roots rather than synthesis. The TR-I gene expression was found to be up-regulated on exposure to signal molecules (methyl jasmonate and salicylic acid) and on mechanical injury. The enzyme's catalytic and structural properties as well as gene expression profiles are discussed with respect to their physiological overtones. PMID:24086372

  11. Tropine Forming Tropinone Reductase Gene from Withania somnifera (Ashwagandha): Biochemical Characteristics of the Recombinant Enzyme and Novel Physiological Overtones of Tissue-Wide Gene Expression Patterns

    PubMed Central

    Kushwaha, Amit Kumar; Sangwan, Neelam Singh; Trivedi, Prabodh Kumar; Negi, Arvind Singh; Misra, Laxminarain; Sangwan, Rajender Singh

    2013-01-01

    Withania somnifera is one of the most reputed medicinal plants of Indian systems of medicine synthesizing diverse types of secondary metabolites such as withanolides, alkaloids, withanamides etc. Present study comprises cloning and E. coli over-expression of a tropinone reductase gene (WsTR-I) from W. somnifera, and elucidation of biochemical characteristics and physiological role of tropinone reductase enzyme in tropane alkaloid biosynthesis in aerial tissues of the plant. The recombinant enzyme was demonstrated to catalyze NADPH-dependent tropinone to tropine conversion step in tropane metabolism, through TLC, GC and GC-MS-MS analyses of the reaction product. The functionally active homodimeric ∼60 kDa enzyme catalyzed the reaction in reversible manner at optimum pH 6.7. Catalytic kinetics of the enzyme favoured its forward reaction (tropine formation). Comparative 3-D models of landscape of the enzyme active site contours and tropinone binding site were also developed. Tissue-wide and ontogenic stage-wise assessment of WsTR-I transcript levels revealed constitutive expression of the gene with relatively lower abundance in berries and young leaves. The tissue profiles of WsTR-I expression matched those of tropine levels. The data suggest that, in W. somnifera, aerial tissues as well possess tropane alkaloid biosynthetic competence. In vivo feeding of U-[14C]-sucrose to orphan shoot (twigs) and [14C]-chasing revealed substantial radiolabel incorporation in tropinone and tropine, confirming the de novo synthesizing ability of the aerial tissues. This inherent independent ability heralds a conceptual novelty in the backdrop of classical view that these tissues acquire the alkaloids through transportation from roots rather than synthesis. The TR-I gene expression was found to be up-regulated on exposure to signal molecules (methyl jasmonate and salicylic acid) and on mechanical injury. The enzyme's catalytic and structural properties as well as gene expression profiles are discussed with respect to their physiological overtones. PMID:24086372

  12. Comparison of the physiological responses and time-motion characteristics of young soccer players in small-sided games: the effect of goalkeeper.

    PubMed

    Köklü, Yusuf; Sert, Özcan; Alemdaroğlu, Utku; Arslan, Yunus

    2015-04-01

    The purpose of this study was to investigate the effect of "with goalkeeper" (SSGwith) and "without goalkeeper" (SSGwithout) conditions on players' physiological responses and time-motion characteristics in small-sided games. Sixteen young soccer players (age: 16.5 ± 1.5 years; height: 175.5 ± 5.2 cm; body mass: 63.0 ± 6.9 kg; training experience: 6.3 ± 1.3 years) participated in 2 different 2-a-side, 3-a-side, and 4-a-side games: SSGwith and SSGwithout. The players underwent anthropometric measurements (height and body mass) followed by the Yo-Yo intermittent recovery test (level 1). Then they played 2-a-side, 3-a-side, and 4-a-side SSGwith and SSGwithout soccer-specific SSGs in random order at 2-day intervals. Heart rate (HR) responses and distance covered in different speed zones (walking [WLK, 0-6.9 km·h(-1)], low-intensity running [LIR, 7.0-12.9 km·h(-1)], moderate-intensity running [MIR, 13.0-17.9 km·h(-1)], and high-intensity running [HIR, >18 km·h(-1)]) were measured during the SSGs, whereas the rating of perceived exertion (RPE) and blood lactate (La) were determined at the end of the last bout of each SSG. During the SSGwithout players showed higher %HR, La, and RPE (p ≤ 0.05), greater distance covered in LIR, MIR, HIR, and total distance (p ≤ 0.05) compared with the SSGwith during the 2-a-side, 3-a-side, and 4-a-side games. The results of this study suggest that both SSGwith and SSGwithout could be used for the physiological adaptations required for soccer-specific aerobic endurance. However, if coaches want both higher physiological responses and greater distance covered in the intensity running zone from their teams, SSGwithout should be organized. In addition, this study also suggests that smaller format games (i.e., 2-a-side) may promote some anaerobic adaptations for youth soccer players. PMID:23942169

  13. Impact of Providing Feed and/or Water on Performance, Physiology, and Behavior of Weaned Pigs during a 32-h Transport

    PubMed Central

    Garcia, Arlene; Sutherland, Mhairi; Pirner, Glenna; Picinin, Guilherme; May, Matthew; Backus, Brittany; McGlone, John

    2016-01-01

    Simple Summary Transportation has the potential to negatively affect the health and welfare of weaned pigs, especially those already experiencing weaning stress. Piglets were transported for 32 h, with and without feed and water, and measures of performance, physiology, and behavior were taken to assess piglet welfare. Transportation negatively impacted body weight, Neutrophil to Lymphocyte Ratio (N:L), and post-transport body weight gain, indicating that not providing water during transport can negatively impact the well-being of recently weaned pigs. Provision of water may aid in reducing stress during long distance transport and improve the animals’ well-being. Abstract Transportation at weaning is a complex stressor made up of many factors, including withdrawal from feed and water, which can potentially negatively affect the health and welfare of pigs, especially those already experiencing weaning stress. The objective of this study was to evaluate the effect of weaning and extended transport durations (up to 32 h), with and without the provision of feed and/or water, on pig welfare. Treatment groups included: pigs neither weaned nor transported, control (CON); weaned pigs transported and provided with feed and water (T+); weaned pigs transported without feed and water (T−); weaned pigs transported with only feed (T+F); and weaned pigs transported with only water provided (TRAN+W). The effect of transport (with and without feed and/or water) on weaned pigs was assessed using behavior, performance, and physiology. After a 32-h transport period, pigs transported without water lost markedly more weight than those transported with water (p < 0.01). Furthermore, the neutrophil to lymphocyte ratio was markedly higher in male pigs transported without water (p < 0.05). Overall, transportation had a negative effect on pig well-being, especially when water was not provided. PMID:27153096

  14. Starch Granule Re-Structuring by Starch Branching Enzyme and Glucan Water Dikinase Modulation Affects Caryopsis Physiology and Metabolism.

    PubMed

    Shaik, Shahnoor S; Obata, Toshihiro; Hebelstrup, Kim H; Schwahn, Kevin; Fernie, Alisdair R; Mateiu, Ramona V; Blennow, Andreas

    2016-01-01

    Starch is of fundamental importance for plant development and reproduction and its optimized molecular assembly is potentially necessary for correct starch metabolism. Re-structuring of starch granules in-planta can therefore potentially affect plant metabolism. Modulation of granule micro-structure was achieved by decreasing starch branching and increasing starch-bound phosphate content in the barley caryopsis starch by RNAi suppression of all three Starch Branching Enzyme (SBE) isoforms or overexpression of potato Glucan Water Dikinase (GWD). The resulting lines displayed Amylose-Only (AO) and Hyper-Phosphorylated (HP) starch chemotypes, respectively. We studied the influence of these alterations on primary metabolism, grain composition, starch structural features and starch granule morphology over caryopsis development at 10, 20 and 30 days after pollination (DAP) and at grain maturity. While HP showed relatively little effect, AO showed significant reduction in starch accumulation with re-direction to protein and β-glucan (BG) accumulation. Metabolite profiling indicated significantly higher sugar accumulation in AO, with re-partitioning of carbon to accumulate amino acids, and interestingly it also had high levels of some important stress-related metabolites and potentially protective metabolites, possibly to elude deleterious effects. Investigations on starch molecular structure revealed significant increase in starch phosphate and amylose content in HP and AO respectively with obvious differences in starch granule morphology at maturity. The results demonstrate that decreasing the storage starch branching resulted in metabolic adjustments and re-directions, tuning to evade deleterious effects on caryopsis physiology and plant performance while only little effect was evident by increasing starch-bound phosphate as a result of overexpressing GWD. PMID:26891365

  15. Starch Granule Re-Structuring by Starch Branching Enzyme and Glucan Water Dikinase Modulation Affects Caryopsis Physiology and Metabolism

    PubMed Central

    Shaik, Shahnoor S.; Obata, Toshihiro; Hebelstrup, Kim H.; Schwahn, Kevin; Fernie, Alisdair R.; Mateiu, Ramona V.; Blennow, Andreas

    2016-01-01

    Starch is of fundamental importance for plant development and reproduction and its optimized molecular assembly is potentially necessary for correct starch metabolism. Re-structuring of starch granules in-planta can therefore potentially affect plant metabolism. Modulation of granule micro-structure was achieved by decreasing starch branching and increasing starch-bound phosphate content in the barley caryopsis starch by RNAi suppression of all three Starch Branching Enzyme (SBE) isoforms or overexpression of potato Glucan Water Dikinase (GWD). The resulting lines displayed Amylose-Only (AO) and Hyper-Phosphorylated (HP) starch chemotypes, respectively. We studied the influence of these alterations on primary metabolism, grain composition, starch structural features and starch granule morphology over caryopsis development at 10, 20 and 30 days after pollination (DAP) and at grain maturity. While HP showed relatively little effect, AO showed significant reduction in starch accumulation with re-direction to protein and β-glucan (BG) accumulation. Metabolite profiling indicated significantly higher sugar accumulation in AO, with re-partitioning of carbon to accumulate amino acids, and interestingly it also had high levels of some important stress-related metabolites and potentially protective metabolites, possibly to elude deleterious effects. Investigations on starch molecular structure revealed significant increase in starch phosphate and amylose content in HP and AO respectively with obvious differences in starch granule morphology at maturity. The results demonstrate that decreasing the storage starch branching resulted in metabolic adjustments and re-directions, tuning to evade deleterious effects on caryopsis physiology and plant performance while only little effect was evident by increasing starch-bound phosphate as a result of overexpressing GWD. PMID:26891365

  16. Physiology of food spoilage organisms.

    PubMed

    Roller, S

    1999-09-15

    A thorough understanding of the physiological responses of microorganisms to stresses imposed during food preservation is essential if novel combination systems based on mild food processing procedures are to be developed effectively. The influences of intrinsic characteristics as well as external factors such as water activity, temperature, preservatives, composition of the gaseous atmosphere, etc. on the stress response of microorganisms are discussed. The interaction of spoilage organisms with each other as well as with food pathogens and the ultimate consequences for food safety and quality are also explored in this review. PMID:10488850

  17. Determination of characteristics and drinking water quality index in Mzuzu City, Northern Malawi

    NASA Astrophysics Data System (ADS)

    Wanda, Elijah M. M.; Gulula, Lewis C.; Phiri, Gift

    An assessment of characteristics and chemical water quality index (WQI) of water supplied by the Northern Region water Board (NRWB) in Mzuzu City was carried out in order to ascertain the quality of water for domestic purposes. The WQI offers a single number that expresses overall water quality for a water sample based on several water quality parameters. In this study raw water and 72 tap water samples were collected monthly between March and September, 2011 and analyzed for major ions, pH, total dissolved solids (TDSs), electrical conductivity (EC), turbidity, total hardness (TH), suspended solids (SSs) and alkalinity using standard methods. The quality and accuracy of the chemical data was assessed by checking electrical balances. The calculated electrical balance errors were found to be less than ±10%, which meant the results were reliable. Based on the Sawyer and McCarty TH classification, 100% of the samples were soft waters (TH < 150 mg/L). Nitrates, which registered medium or average WQ-rating of 69.77 and WQ-rating range of 52.06-86.94, were observed to have significantly affected the overall water quality index of the treated water since the rest of the parameters registered good-excellent WQ-ratings (average WQ-rating: 80.21-97.87). The pH, which is used to determine suitability of water for various purposes, ranged between 6.40 and 6.90 and registered a good water quality rating (WQ rating range: 72.73-87.02) for both raw and treated water. Raw water registered an overall medium water quality rating of 62.67%. Overall, 91.67% of the samples registered a good water quality rating (WQI range: 80.28-88.80%) and 8.33% registered a very good water quality rating (WQI = 90.07%). The results suggested substantial water treatment by the NRWB since the treated water is protected with some negligible degree of impairment that rarely departs from desirable levels of domestic water quality. It is recommended that the WQI should be adopted as a tool to monitor and establish trends in quality of water supplied by the NRWB since it is a composite index that turns complex water quality data into an aggregate rating that reflects the combined influence on the overall water quality as opposed to the univariate water quality assessment approaches such as the Malawi Bureau of Standards.

  18. [Characteristics of Hydrogen and Oxygen Isotopes of Soil Water in the Water Source Area of Yuanyang Terrace].

    PubMed

    Zhang, Xiao-juan; Song, Wei-feng; Wu, Jin-kui; Wang, Zhuo-juan

    2015-06-01

    Stable isotope techniques provide a new approach to study soil water movement. The precipitation and the soil water from 0 to 100 cm soil layer in 4 kinds of typical vegetation types (forest, shrub forest, grassland and non-forest land) over the water source area of Yuanyang terrace were sampled, and their isotope compositions were analyzed, aimed to understand the characteristics of stable isotopes in different depth of the soil water. The results showed that the meteoric water line in the water source area of Yuanyang terrace was δD = 6.838 4δ(18)O-5.6921 (R2 = 0.8787, n = 20), the slope and intercept were less than the global atmospheric precipitation. The hydrogen and oxygen stable isotopes in the soil water of the 4 kinds of typical types was lower than the local meteoric water line side and the fluctuation of isotope value on surface soil profile was greater. With the increasing soil depth, the fluctuation of delta 18O value was smaller and smaller, especially in the 80-100 cm soil layer which was the most obvious. The delta 18O values of the deep soil water in forest and grassland were higher than that in the surface soil. while it was on the contrary in shrub forest and non-forest land. PMID:26387313

  19. Physiological characteristics of classical ballet.

    PubMed

    Schantz, P G; Astrand, P O

    1984-10-01

    The aerobic and anaerobic energy yield during professional training sessions ("classes") of classical ballet as well as during rehearsed and performed ballets has been studied by means of oxygen uptake, heart rate, and blood lactate concentration determinations on professional ballet dancers from the Royal Swedish Ballet in Stockholm. The measured oxygen uptake during six different normal classes at the theatre averaged about 35-45% of the maximal oxygen uptake, and the blood lactate concentration averaged 3 mM (N = 6). During 10 different solo parts of choreographed dance (median length = 1.8 min) representative for moderately to very strenuous dance, an average oxygen uptake (measured during the last minute) of 80% of maximum and blood lactate concentration of 10 mM was measured (N = 10). In addition, heart rate registrations from soloists in different ballets during performance and final rehearsals frequently indicated a high oxygen uptake relative to maximum and an average blood lactate concentration of 11 mM (N = 5). Maximal oxygen uptake, determined in 1971 (N = 11) and 1983 (N = 13) in two different groups of dancers, amounted to on the average 51 and 56 ml X min-1 X kg-1 for the females and males, respectively. In conclusion, classical ballet is a predominantly intermittent type of exercise. In choreographed dance each exercise period usually lasts only a few minutes, but can be very demanding energetically, while during the dancers' basic training sessions, the energy yield is low. PMID:6513765

  20. Physical characteristics of GE (General Electric) BWR (boiling-water reactor) fuel assemblies

    SciTech Connect

    Moore, R.S.; Notz, K.J.

    1989-06-01

    The physical characteristics of fuel assemblies manufactured by the General Electric Company for boiling-water reactors are classified and described. The classification into assembly types is based on the GE reactor product line, the Characteristics Data Base (CDB) assembly class, and the GE fuel design. Thirty production assembly types are identified. Detailed physical data are presented for each assembly type in an appendix. Descriptions of special (nonstandard) fuels are also reported. 52 refs., 1 fig., 6 tabs.

  1. Cooling cows efficiently with water spray: Behavioral, physiological, and production responses to sprinklers at the feed bunk.

    PubMed

    Chen, Jennifer M; Schütz, Karin E; Tucker, Cassandra B

    2016-06-01

    Dairies commonly mount nozzles above the feed bunk that intermittently spray cows to dissipate heat. These sprinklers use potable water-an increasingly scarce resource-but there is little experimental evidence for how much is needed to cool cows in loose housing. Sprinkler flow rate may affect the efficacy of heat abatement, cattle avoidance of spray (particularly on the head), and water waste. Our objectives were to determine how sprinkler flow rate affects cattle behavioral, physiological, and production responses when cows are given 24-h access to spray in freestall housing, and to evaluate heat abatement in relation to water use. We compared 3 treatments: sprinklers that delivered 1.3 or 4.9L/min (both 3min on and 9min off, 24h/d) and an unsprayed control. Nine pairs of high-producing lactating Holstein cows received each treatment at a shaded feed bunk for 2d in a replicated 3×3 Latin square design [air temperature (T): 24-h maximum=33±3°C, mean ± SD]. Cows spent 5.8±0.9h/24h (mean ± SD) at the feed bunk overall, regardless of treatment. With few exceptions, cows responded similarly to the 1.3 and 4.9L/min flow rates. Sprinklers resulted in visits to the feed bunk that were on average 23 to 27% longer and 13 to 16% less frequent compared with the control, perhaps because cows avoided walking through spray. Indeed, when the sprinklers were on, cows left the feed bunk half as often as expected by chance, and when cows chose to walk through spray, they lowered their heads on average 1.7- to 3-fold more often than in the control. Despite possible reluctance to expose their heads to spray, cows did not avoid sprinklers overall. In warmer weather, cows spent more time at the feed bunk when it had sprinklers (on average 19 to 21min/24h for each 1°C increase in T), likely for heat abatement benefits. Compared with the control, sprinklers resulted in 0.3 to 0.7°C lower body temperature from 1300 to 1500h and 1700 to 2000h overall and attenuated the rise in this measure on warmer days (for each 10°C increase in T, body temperature increased by on average 0.5 to 0.7°C with sprinklers vs. 1.6°C without). Sprinkler access also resulted in milk yield that was, on average, 3.3 to 3.7kg/24h higher than in the control treatment. In this hot and dry climate, 1.3L/min cooled cows more efficiently than 4.9L/min, as the lower flow rate achieved equivalent reduction in body temperature and increase in milk yield relative to no spray, despite using 73% less water. PMID:27060833

  2. [Effects of regulated deficit irrigation on water consumption characteristics and water use efficiency of winter wheat].

    PubMed

    Han, Zhan-Jiang; Yu, Zhen-Wen; Wang, Dong; Wang, Xi-Zhi; Xu, Zhen-Zhu

    2009-11-01

    With the high-yielding winter wheat cultivar Jimai 22 as test material, a field experiment was conducted in Yanzhou of Shandong to examine the effects of regulated deficit irrigation on the water consumption and water use efficiency (WUE) of the cultivar. Five treatments were installed, i.e., the soil relative moisture content at sowing, jointing, and anthesis stages being 80%, 65% and 65% (W0), 80%, 70% and 70% (W1), 80%, 80% and 80% (W2), 90%, 80% and 80% (W3), and 90%, 85% and 85% (W4), respectively. Under the condition of 228 mm precipitation in growth season, the total water consumption was higher in treatments W1 and W4 than in treatments W0, W2, and W3, and no difference was observed between treatments W1 and W4. Comparing with W4, treatment W1 decreased the water storage in 0-200 cm soil layer and the water consumption by wheat from jointing to anthesis stages, but increased the water consumption from anthesis to maturity stages. The water consumption rates at the stages from jointing to anthesis and from anthesis to maturity in treatment W4 were higher. Under regulated deficit irrigation, treatment W0 had higher WUE, but the grain yield was the lowest. The WUE in other treatments increased first, and then decreased with increasing irrigation amount. Both the water consumption and the grain yield were the highest in treatments W1 and W4, and treatment W1 had higher irrigation water use efficiency and irrigation benefit than treatment W4, being the best irrigation regime of high-yielding and water-saving in our study. PMID:20135999

  3. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    PubMed

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity. PMID:17283377

  4. Effect of ultraviolet-B radiation in laboratory on morphological and ultrastructural characteristics and physiological parameters of selected cultivar of Oryza sativa L.

    PubMed

    de Almeida, Sérgio L; Schmidt, Éder C; Pereira, Debora Tomazi; Kreusch, Marianne; Felix, Marthiellen R de L; Osorio, Luz K P; de Paula Martins, Roberta; Latini, Alexandra; Ramlov, Fernanda; Chow, Fungyi; Maraschin, Marcelo; Rodrigues, Ana C; Bouzon, Zenilda L

    2013-12-01

    Ultraviolet-B radiation (UVBR) affects plants in many important ways, including reduction of growth rate and primary productivity, and changes in ultrastructures. Rice (Oryza sativa) is one of the most cultivated cereals in the world, along with corn and wheat, representing over 50% of agricultural production. In this study, we examined O. sativa plants exposed to ambient outdoor radiation and laboratory-controlled photosynthetically active radiation (PAR) and PAR + UVBR conditions for 2 h/day during 30 days of cultivation. The samples were studied for morphological and ultrastructural characteristics, and physiological parameters. PAR + UVBR caused changes in the ultrastructure of leaf of O. sativa and leaf morphology (leaf index, leaf area and specific leaf area, trichomes, and papillae), plant biomass (dry and fresh weight), photosynthetic pigments, phenolic compounds, and protein content. As a photoprotective acclimation strategy against PAR + UVBR damage, an increase of 66.24% in phenolic compounds was observed. Furthermore, PAR + UVBR treatment altering the levels of chlorophylls a and b, and total chlorophyll. In addition, total carotenoid contents decreased after PAR + UVBR treatment. The results strongly suggested that PAR + UVBR negatively affects the ultrastructure, morphology, photosynthetic pigments, and growth rates of leaf of O. sativa and, in the long term, it could affect the viability of this economically important plant. PMID:23708376

  5. Static Characteristics of Absorption Chiller-Heater Supplying Cold and Hot Water Simultaneously

    NASA Astrophysics Data System (ADS)

    Inoue, Naoyuki; Irie, Tomoyoshi

    Absorption chiller-heaters which can supply both chilled water and hot water at the same time, are used for cooling and heating air conditioning systems. In this paper, we classified absorption cold and hot water generating cycles and control methods, studied these absorption cycles by cycle simulation. In economizer cycle, condensed refrigerant which heats hot water is transported to cooling cycle and used effectively for cooling chilled water, Concerning with transported condensed refrigerant, there are two methods, all condensed refrigerant or required refrigerant for cooling are transported to cooling cycle, and required refrigerant method is better for energy saving. Adding improvement of solution control to this economizer cycle, simultaneous cold and hot water supplying chiller-heaters have good characteristics of energy saving in the all region.

  6. Chemical and physical characteristics of natural ground waters in Michigan; a preliminary report

    USGS Publications Warehouse

    Cummings, T. Ray

    1980-01-01

    Wide variations occur in the chemical and physical characteristics of natural groundwaters in Michigan. Dissolved-solids concentrations range from 23 to 2,100 milligrams per liter. Waters having low dissolved-solids concentrations are calcium bicarbonate waters. Sodium, sulfate, and chloride increase as mineralization increases. Iron, aluminum, and titanium are higher at some locations than is common in most natural waters. Lead concentrations exceed those desirable in drinking water at some locations in the northern part of the Lower Peninsula. Generalized areal patterns of water quality variation suggest that geology is a primary cause of differences across the State. Examples of chemical associations in water suggest that chemical analyses may be valuable in tracing and identifying mineral deposits. (USGS)

  7. A Characteristic Transmission Spectrum for WFC3 IR Water Hosting Exoplanet

    NASA Astrophysics Data System (ADS)

    Swain, Mark R.

    2015-12-01

    Using the 19 published Hubble/WFC3 IR exoplanet transmission spectra, we perform a meta-analysis of the spectral modulation due to water. Because of the heterogeneous nature of these data, in which spectral resolution, calibration approach, and observational method vary, we introduce a formalism to de-bias the estimates of spectral modulation. This analysis finds a characteristic transmission spectrum and examines trends for these water-hosting exoplanets.

  8. Use of an automated chromium reduction system for hydrogen isotope ratio analysis of physiological fluids applied to doubly labeled water analysis.

    PubMed

    Schoeller, D A; Colligan, A S; Shriver, T; Avak, H; Bartok-Olson, C

    2000-09-01

    The doubly labeled water method is commonly used to measure total energy expenditure in free-living subjects. The method, however, requires accurate and precise deuterium abundance determinations, which can be laborious. The aim of this study was to evaluate a fully automated, high-throughput, chromium reduction technique for the measurement of deuterium abundances in physiological fluids. The chromium technique was compared with an off-line zinc bomb reduction technique and also subjected to test-retest analysis. Analysis of international water standards demonstrated that the chromium technique was accurate and had a within-day precision of <1 per thousand. Addition of organic matter to water samples demonstrated that the technique was sensitive to interference at levels between 2 and 5 g l(-1). Physiological samples could be analyzed without this interference, plasma by 10000 Da exclusion filtration, saliva by sedimentation and urine by decolorizing with carbon black. Chromium reduction of urine specimens from doubly labeled water studies indicated no bias relative to zinc reduction with a mean difference in calculated energy expenditure of -0.2 +/- 3.9%. Blinded reanalysis of urine specimens from a second doubly labeled water study demonstrated a test-retest coefficient of variation of 4%. The chromium reduction method was found to be a rapid, accurate and precise method for the analysis of urine specimens from doubly labeled water. PMID:11006607

  9. Variation in water potential, hydraulic characteristics and water source use in montane Douglas-fir and lodgepole pine trees in southwestern Alberta and consequences for seasonal changes in photosynthetic capacity.

    PubMed

    Andrews, Shilo F; Flanagan, Lawrence B; Sharp, Eric J; Cai, Tiebo

    2012-02-01

    Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex Loud. var. latifolia Engelm. (lodgepole pine) and Pseudotsuga menziesii (Mirb.) Franco (interior Douglas-fir), and determined the consequences for seasonal changes in photosynthetic capacity. The Douglas-fir site had soil with greater depth, finer texture and higher organic matter content than soil at the lodgepole pine site, all factors that increased the storage of soil moisture. While the measured xylem vulnerability curves were quite similar for the two species, Douglas-fir had lower average midday shoot water potentials than did lodgepole pine. This implied that lodgepole pine exhibited stronger stomatal control of transpiration than Douglas-fir, which helped to reduce the magnitude of the water potential gradient required to access water from drying soil. Stable hydrogen isotope measurements indicated that Douglas-fir increased the use of groundwater during mid-summer when precipitation inputs were low, while lodgepole pine did not. There was a greater reduction of photosynthetic carbon gain in lodgepole pine compared with Douglas-fir when the two tree species were exposed to seasonal declines in soil water content. The contrasting patterns of seasonal variation in photosynthetic capacity observed for the two species were a combined result of differences in soil characteristics at the separate sites and the inherent physiological differences between the species. PMID:22318220

  10. Sprectroradiometric characteristics of inland water bodies infestated by Oscillatoria rubescens algae

    NASA Astrophysics Data System (ADS)

    Ciraolo, Giuseppe; La Loggia, Goffredo; Maltese, Antonino

    2010-10-01

    In December 2006 blooms of Oscillatoria rubescens were found in the reservoir Prizzi in Sicily. Oscillatoria is a genus of filamentous alga comprising approximately 6 species, between these the O. rubescens is sadly famous since this organism produces microcystins which are powerful hepatotoxins. Firstly found in Europe in 1825 on Geneva lake, recently (2006) those algae has been find out in Pozzillo, Nicoletti e Ancipa reservoirs (Enna Province), as well as in Prizzi (Palermo Province) and Garcia reservoirs (Trapani Province). Toxins produced by those bacteria (usually called microcystine LR-1 and LR-2) are highly toxic since they can activate oncogenes cells causing cancer pathologies on liver and gastrointestinal tract. Even if water treatment plants should ensure the provision of safe drinking water from surface waters contaminated with those toxic algae blooms, the contamination of reservoirs used for civil and agricultural supply highlights human health risks. International literature suggests a threshold value of 0.01 μgl-1 to avoid liver cancer using water coming from contaminated water bodies for a long period. Since O. rubescens activities is strongly related to phosphate and nitrogen compounds as well as to temperature and light transmission within water, the paper presents the comparison between optical properties of the water of an infested reservoir and those of a reservoir characterized by clear water. Field campaigns were carried out in February-March 2008 in order to quantify the spectral transparencies of two water bodies through the calculation of the diffuse attenuation coefficient, measuring underwater downwelling irradiance at different depths as well as water spectral reflectance. Results show that diffuse attenuation coefficient is reduced by approximately 15% reducing light penetration in the water column; coherently reflectance spectral signature generally decreases, exhibiting a characteristic peak around 703 nm not present in uncontaminated waters. Latter findings highlight the possibility to detect O. rubescens infestations using their spectral characteristics by means of multitemporal remote sensing techniques.

  11. Spatial and seasonal patterns in stream water contamination across mountainous watersheds: Linkage with landscape characteristics

    NASA Astrophysics Data System (ADS)

    Ai, L.; Shi, Z. H.; Yin, W.; Huang, X.

    2015-04-01

    Landscape characteristics are widely accepted as strongly influencing stream water quality in heterogeneous watersheds. Understanding the relationships between landscape and specific water contaminant can greatly improve the predictability of potential contamination and the assessment of contaminant export. In this work, we examined the combined effects of watershed complexity, in terms of land use and physiography, on specific water contaminant across watersheds close to the Danjiangkou Reservoir. The land use composition, land use pattern, morphometric variables and soil properties were calculated at the watershed scale and considered potential factors of influence. Due to high co-dependence of these watershed characteristics, partial least squares regression was used to elucidate the linkages between some specific water contaminants and the 16 selected watershed characteristic variables. Water contaminant maps revealed spatial and seasonal heterogeneity. The dissolved oxygen values in the dry season were higher than those in the wet season, whereas the other contaminant concentrations displayed the opposite trend. The studied watersheds which are influenced strongly by urbanization, showed higher levels of ammonia nitrogen, total phosphorus, potassium permanganate index and petroleum, and lower levels of dissolved oxygen. The urban land use, largest patch index and the hypsometric integral were the dominant factors affecting specific water contaminant.

  12. Association of drinking-water source and use characteristics with urinary antimony concentrations.

    PubMed

    Makris, Konstantinos C; Andra, Syam S; Herrick, Lisa; Christophi, Costas A; Snyder, Shane A; Hauser, Russ

    2013-03-01

    Environmental factors, such as storage time, frequency of bottle reuse and temperature, have been shown to facilitate antimony (Sb) leaching from water- and food-packaging materials. The globally escalating consumption of water packaged in Sb-containing bottles, such as that of polyethylene terephthalate (PET), could increase human daily Sb doses. This study set out to investigate the relationship between drinking-water source, use characteristics, and urinary Sb concentrations (U-Sb) accompanied with survey responses of a healthy (n=35) Cypriot participant pool. One spot urine sample was collected during administration of questionnaire, while a second spot urine sample was collected from the same individual about 7 days later. Urinary and water Sb concentrations were measured with an inductively coupled plasma mass spectrometer. Survey responses showed that bottled water summed over various volumes and plastic types, such as polycarbonate and PET contributed to an average 61% of daily water consumption. Water sources such as tap, mobile stations (explained in a following section), and well water contributed to 24%, 14%, and 2% of an individual's daily water consumption pattern, respectively. Average daily potable water use of both bottled and tap water by individuals consisted of 65% drinking-water, while the remaining 35% was water used for preparing cold and hot beverages, such as, tea, coffee, and juices. A significant (P=0.02) association between per capita water consumption from PET bottles and urinary creatinine-unadjusted concentrations was observed, but this relationship did not remain after inclusion of covariates in a multivariate regression model. In the creatinine-adjusted regression model, only gender (female) was a significant (P<0.01) predictor of U-Sb, after adjusting for several covariates. It is proposed that consumption data collection on various water uses and sources among individuals could perhaps decrease the uncertainty associated with derivations of acceptable daily Sb intakes. PMID:23188481

  13. Determination of virtual water content of rice and spatial characteristics analysis in China

    NASA Astrophysics Data System (ADS)

    Zhang, L. J.; Yin, X. A.; Zhi, Y.; Yang, Z. F.

    2014-01-01

    China is a water-stressed country, and agriculture consumes the bulk of its water resources. Assessing the virtual water content (VWC) of crops is one important way to develop efficient water management measures to alleviate water resources conflicts among different sectors. In this research, the VWC of rice, as a major crop in China, was assessed and the spatial characteristics were analyzed. In addition to the calculation of green, blue and grey water - the direct water in VWC - the indirect water use of rice was also calculated, using the Input-Output model. The percentages of direct green, blue, grey and indirect water in the total VWC of rice in China were 43.8, 28.2, 27.6, and 0.4%. The total VWC of rice generally showed a three-tiered distribution, and decreased from southeast to northwest. The higher values of direct green water of rice were mainly concentrated in Southeast and Southwest China, while these values were relatively low in Northwest China and Inner Mongolia. The higher direct blue water values were mainly concentrated in the eastern and southern coastal regions and Northwest China, and low values were mainly concentrated in Southwest China. Grey water values were relatively high in Shanxi and Guangxi provinces and low in Northeast and Northwest China. The regions with high values for indirect water were randomly distributed but the regions with low values were mainly concentrated in Northwest and Southwest China. For the regions with relatively high total VWC the high values of blue water made the largest contribution, although for the country as a whole the direct green water is the most important contributor.

  14. Impact of Providing Feed and/or Water on Performance, Physiology, and Behavior of Weaned Pigs during a 32-h Transport.

    PubMed

    Garcia, Arlene; Sutherland, Mhairi; Pirner, Glenna; Picinin, Guilherme; May, Matthew; Backus, Brittany; McGlone, John

    2016-01-01

    Transportation at weaning is a complex stressor made up of many factors, including withdrawal from feed and water, which can potentially negatively affect the health and welfare of pigs, especially those already experiencing weaning stress. The objective of this study was to evaluate the effect of weaning and extended transport durations (up to 32 h), with and without the provision of feed and/or water, on pig welfare. Treatment groups included: pigs neither weaned nor transported, control (CON); weaned pigs transported and provided with feed and water (T+); weaned pigs transported without feed and water (T-); weaned pigs transported with only feed (T+F); and weaned pigs transported with only water provided (TRAN+W). The effect of transport (with and without feed and/or water) on weaned pigs was assessed using behavior, performance, and physiology. After a 32-h transport period, pigs transported without water lost markedly more weight than those transported with water ( p < 0.01). Furthermore, the neutrophil to lymphocyte ratio was markedly higher in male pigs transported without water ( p < 0.05). Overall, transportation had a negative effect on pig well-being, especially when water was not provided. PMID:27153096

  15. Enthalpy characteristics of sodium phenylalaninate solvation in mixtures of water with ethanol at 298 K

    NASA Astrophysics Data System (ADS)

    Vandyshev, V. N.; Litova, N. A.

    2013-02-01

    The heat effects of mixing for aqueous solutions of sodium phenylalaninate (NaPheAla) with mixtures of water and ethanol are measured by calorimetry at 298.15 K. The standard enthalpies of transfer of a stoichiometric mixture of ions, and of an organic ion of α-PheAla- from water to water-alcohol mixtures are calculated. The enthalpy coefficients of binary and ternary ion-alcohol interactions are calculated using the McMillan-Mayer theory. The obtained enthalpy characteristics are compared with previously studied systems containing synthetic β- and natural α-alanine.

  16. Work Capability and physiological effects predictive studies. 4: In He-O2 excursions to pressures of 400- 800- 1200- and 1600 feet of sea water

    NASA Technical Reports Server (NTRS)

    Lambertsen, C. J. (Editor); Gelfand, R. (Editor); Clark, J. M. (Editor); Fletcher, M. E. (Editor)

    1978-01-01

    Experiments which exposed men in chambers, breathing helium with oxygen, to progressive increases of pressure equivalent to 400-800-1200-1600 feet of sea water (fsw) were conducted. Rates of compression and exposure to stable high pressure. Goals included: 1) determination of the specific character and time course of onset of physiological and performance decrements during the intentionally rapid compressions, and determination of rates of adaptation on reaching stable elevated pressure; 2) investigation of accelerated methods for decompression in deep saturation excursion diving; and 3) determination of competence in practical work performed in water at pressures equivalent to the extreme diving depths of 1200 and 1600 fsw.

  17. The importance of lake-specific characteristics for water quality across the continental United States.

    PubMed

    Read, Emily K; Patil, Vijay P; Oliver, Samantha K; Hetherington, Amy L; Brentrup, Jennifer A; Zwart, Jacob A; Winters, Kirsten M; Corman, Jessica R; Nodine, Emily R; Woolway, R Iestyn; Dugan, Hilary A; Jaimes, Aline; Santoso, Arianto B; Hong, Grace S; Winslow, Luke A; Hanson, Paul C; Weathers, Kathleen C

    2015-06-01

    Lake water quality is affected by local and regional drivers, including lake physical characteristics, hydrology, landscape position, land cover, land use, geology, and climate. Here, we demonstrate the utility of hypothesis testing within the landscape limnology framework using a random forest algorithm on a national-scale, spatially explicit data set, the United States Environmental Protection Agency's 2007 National Lakes Assessment. For 1026 lakes, we tested the relative importance of water quality drivers across spatial scales, the importance of hydrologic connectivity in mediating water quality drivers, and how the importance of both spatial scale and connectivity differ across response variables for five important in-lake water quality metrics (total phosphorus, total nitrogen, dissolved organic carbon, turbidity, and conductivity). By modeling the effect of water quality predictors at different spatial scales, we found that lake-specific characteristics (e.g., depth, sediment area-to-volume ratio) were important for explaining water quality (54-60% variance explained), and that regionalization schemes were much less effective than lake specific metrics (28-39% variance explained). Basin-scale land use and land cover explained between 45-62% of variance, and forest cover and agricultural land uses were among the most important basin-scale predictors. Water quality drivers did not operate independently; in some cases, hydrologic connectivity (the presence of upstream surface water features) mediated the effect of regional-scale drivers. For example, for water quality in lakes with upstream lakes, regional classification schemes were much less effective predictors than lake-specific variables, in contrast to lakes with no upstream lakes or with no surface inflows. At the scale of the continental United States, conductivity was explained by drivers operating at larger spatial scales than for other water quality responses. The current regulatory practice of using regionalization schemes to guide water quality criteria could be improved by consideration of lake-specific characteristics, which were the most important predictors of water quality at the scale of the continental United States. The spatial extent and high quality of contextual data available for this analysis makes this work an unprecedented application of landscape limnology theory to water quality data. Further, the demonstrated importance of lake morphology over other controls on water quality is relevant to both aquatic scientists and managers. PMID:26465035

  18. Influence of multiple water-quality characteristics on copper toxicity to fathead minnows (Pimephales promelas)

    USGS Publications Warehouse

    Sciera, K.L.; Isely, J.J.; Tomasso, J.R., Jr.; Klaine, S.J.

    2004-01-01

    Water quality influences the bioavailability and toxicity of copper to aquatic organisms. Understanding the relationships between water-quality parameters and copper toxicity may facilitate the development of site-specific criteria for water quality and result in better protection of aquatic biota. Many studies have examined the influence of a single water-quality parameter on copper toxicity, but the interactions of several characteristics have not been well studied in low-hardness water. The goal of the present research was to examine the interactions among water-quality characteristics and their effects on copper toxicity to larval fathead minnows (Pimephales promelas). The effects of dissolved organic carbon (DOC) concentration, DOC source, pH, and hardness on acute copper toxicity were determined using a complete factorially designed experiment. Hardness, pH, DOC, and interaction of pH and DOC all significantly affected copper toxicity. A predictive model based on these data described 88% of the variability in copper toxicity. This model also explained 58% of the variability in copper toxicity for an independent dataset of South Carolina (USA) waters. The biotic ligand model underpredicted the acute copper toxicity to fathead minnows when compared with observed values.

  19. Comparison of selected cultural, physical, and water-quality characteristics of lakes in Washington

    USGS Publications Warehouse

    Bortleson, Gilbert Carl; Dion, N.P.

    1979-01-01

    The report presents comparisons and a graphical overview of the relative magnitude and regional and statewide distribution of 19 selected cultural, physical, and water-quality characteristics measured in a reconnaissance study of several hundred lakes in Washington. Statewide, mean depth of almost one-fourth of the lakes is shallow (2.0 meters or less), and only 7 percent of the lakes have mean depths greater than 20 meters. About one-third of the lakes had Secchi-disc readings of 2.0 meters or less, a value often considered characteristic of eutrophic lakes. The poorest water clarity was observed in the Columbia Plateau, where 68 percent of the lakes had Secchi-disc readings of less than 2.0 meters. More than one-third of the lakes in the State had total phosphorus concentrations that exceeded 30 micrograms per liter, a concentration that is often considered characteristic of eutrophic lakes. (Woodard-USGS)

  20. Monitoring water stress and fruit quality in an orange orchard under regulated deficit irrigation using narrow-band structural and physiological remote sensing indices

    NASA Astrophysics Data System (ADS)

    Stagakis, S.; González-Dugo, V.; Cid, P.; Guillén-Climent, M. L.; Zarco-Tejada, P. J.

    2012-07-01

    This paper deals with the monitoring of water status and the assessment of the effect of stress on citrus fruit quality using structural and physiological remote sensing indices. Four flights were conducted over a citrus orchard in 2009 using an unmanned aerial vehicle (UAV) carrying a multispectral camera with six narrow spectral bands in the visible and near infrared. Physiological indices such as the Photochemical Reflectance Index (PRI570), a new structurally robust PRI formulation that uses the 515 nm as the reference band (PRI515), and a chlorophyll ratio (R700/R670) were compared against the Normalized Difference Vegetation Index (NDVI), Renormalized Difference Vegetation Index (RDVI) and Modified Triangular Vegetation Index (MTVI) canopy structural indices for their performance in tracking water status and the effects of sustained water stress on fruit quality at harvest. The irrigation setup in the commercial orchard was compared against a treatment scheduled to satisfy full requirements (based on estimated crop evapotranspiration) using two regulated deficit irrigation (RDI) strategies. The water status of the trees throughout the experiment was monitored with frequent field measurements of stem water potential (Ψx), while titratable acidity (TA) and total soluble solids (TSS) were measured at harvest on selected trees from each irrigation treatment. The high spatial resolution of the multispectral imagery (30 cm pixel size) enabled identification of pure tree crown components, extracting the tree reflectance from shaded, sunlit and aggregated pixels. The physiological and structural indices were then calculated from each tree at the following levels: (i) pure sunlit tree crown, (ii) entire crown, aggregating the within-crown shadows, and (iii) simulating a lower resolution pixel, including tree crown, sunlit and shaded soil pixels. The resulting analysis demonstrated that both PRI formulations were able to track water status, except when water stress altered canopy structure. In such cases, PRI570 was more affected than PRI515 by the structural changes caused by sustained water stress throughout the season. Both PRI formulations were proven to serve as pre-visual water stress indicators linked to fruit quality TSS and TA parameters (r2 = 0.69 for PRI515 vs TSS; r2 = 0.58 vs TA). In contrast, the chlorophyll (R700/R670) and structural indices (NDVI, RDVI, MTVI) showed poor relationships with fruit quality and water status levels (r2 = 0.04 for NDVI vs TSS; r2 = 0.19 vs TA). The two PRI formulations showed strong relationships with the field-measured fruit quality parameters in September, the beginning of stage III, which appeared to be the period most sensitive to water stress and the most critical for assessing fruit quality in citrus. Both PRI515 and PRI570 showed similar performance for the two scales assessed (sunlit crown and entire crown), demonstrating that within-crown component separation is not needed in citrus tree crowns where the shaded vegetation component is small. However, the simulation conducted through spatial resampling on tree + soil aggregated pixels revealed that the physiological indices were highly affected by soil reflectance and between-tree shadows, showing that for TSS vs PRI515 the relationship dropped from r2 = 0.69 to r2 = 0.38 when aggregating soil + crown components. This work confirms a previous study that demonstrated the link between PRI570, water stress, and fruit quality, while also making progress in assessing the new PRI formulation (PRI515), the within-crown shadow effects on the physiological indices, and the need for high resolution imagery to target individual tree crowns for the purpose of evaluating the effects of water stress on fruit quality in citrus.

  1. Physiological Waterfalls

    ERIC Educational Resources Information Center

    Leith, David E.

    1976-01-01

    Provides background information, defining areas within organ systems where physiological waterfalls exist. Describes pressure-flow relationships of elastic tubes (blood vessels, airways, renal tubules, various ducts). (CS)

  2. The vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of kerosene

    NASA Astrophysics Data System (ADS)

    Liang, Jin-Hu; Wang, Su; Zhang, Sheng-Tao; Yue, Lian-Jie; Fan, Bing-Cheng; Zhang, Xin-Yu; Cui, Ji-Ping

    2014-08-01

    In ground tests of hypersonic scramjet, the high-enthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characteristics of fuels between ground tests and real flights. In order to properly assess the influence of the contaminants on ignition characteristics of hydrocarbon fuels, the effect of water vapor and carbon dioxide on the ignition delay times of China RP-3 kerosene was studied behind reflected shock waves in a preheated shock tube. Experiments were conducted over a wider temperature range of 800-1 500K, at a pressure of 0.3 MPa, equivalence ratios of 0.5 and 1, and oxygen concentration of 20%. Ignition delay times were determined from the onset of the excited radical OH emission together with the pressure profile. Ignition delay times were measured for four cases: (1) clean gas, (2) gas vitiated with 10% and 20% water vapor in mole, (3) gas vitiated with 10% carbon dioxide in mole, and (4) gas vitiated with 10% water vapor and 10% carbon dioxide, 20% water vapor and 10% carbon dioxide in mole. The results show that carbon dioxide produces an inhibiting effect at temperatures below 1 300 K when ϕ = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when ϕ = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at ϕ = 0.5, while no effect is found at ϕ = 1.0. The results are also discussed preliminary by considering both the combustion reaction mechanism and the thermophysics properties of the fuel mixtures. The current measurements demonstrate vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of China RP-3 kerosene at air-like O2 concentration. It is important to account for such effects when data are extrapolated from ground testing to real flight conditions.

  3. [Differences in water consumption characteristics and grain yield of different wheat cultivars].

    PubMed

    Yan, Xue-mei; Yu, Zhen-wen; Zhang, Yong-li; Wang, Dong

    2011-03-01

    A field experiment with 10 wheat cultivars was conducted to study the water consumption characteristics at different growth stages and the differences in the grain yield of the cultivars. Three irrigation treatments were installed, i.e., no irrigation (W0), irrigation before sowing and at jointing stage (W1), and irrigation before sowing and at jointing and anthesis stages (W2), with irrigation amount 60 mm each time. Based on the cluster analysis with the parameters grain yield and water use efficiency (WUE) in the three treatments, the test ten cultivars could be divided into three groups, i.e., high yield and high WUE (Group I), high yield and medium WUE (Group II), and medium yield and low WUE (Group III). The average values of grain yield and WUE in each group were calculated to elucidate the water consumption characteristics of the three groups. In treatment W0, the total water consumption amount in the whole growth period, the water consumption amount from anthesis to maturing stages and its proportion to the total water consumption amount of Group I were lower than those of Group II and Group III, but the grain yield of Group I was the highest. In treatment W1, the water consumption amount from jointing to anthesis stages and its proportion to total water consumption amount of Group I were lower than those of Group II and Group III, but the water consumption amount from anthesis to maturing stages had no significant differences among Group I, Group II, and Group III. In treatment W2, the total soil water consumption amount, water consumption amount from jointing to anthesis stages and its proportion to total water consumption amount of Group I were lower than those of Group II and Group III, while the water consumption amount from anthesis to maturity stages and its proportion to total water consumption amount of both Group I and Group III were lower than those of Group II. In terms of high-yield and water-saving under the present experimental condition, it was implicated that the most appropriate cultivars might fall into the Group I with high yield and high WUE, and the most appropriate irrigation regime with high yield and low water consumption was treatment W1, i.e., irrigated 60 mm each time before sowing and at jointing stage. PMID:21657026

  4. Understanding how the leaf physiology of mangrove plants differs from fresh water plants: a fundamental step to use cellulose as a proxy for sea level rise

    NASA Astrophysics Data System (ADS)

    Ellsworth, P.; Sternberg, L. O.

    2010-12-01

    We studied the leaf water isotopic enrichment pattern of mangrove (halophytes) and hammock (glycophytes) plants as an attempt to explain why the δ18O of stem cellulose from mangrove and hammock species have no relationship with the δ18O of source water. A better understanding of leaf physiology of mangroves and its effect on the δ18O of stem cellulose is the first step in the process of developing an isotopic proxy for sea-level rise. Seawater is enriched in 18O relative to freshwater and this difference should be recorded in stem cellulose during its synthesis. Therefore, an enrichment in the oxygen isotope ratios of cellulose would reflect an increase in sea water levels. However, only ~40% of the 18O signal of stem cellulose comes from source water, the other ~60% comes from leaf water. Mangrove and hammock plants respond to environment conditions differently, which calls for a better understanding of leaf physiology and the ability to tease leaf physiolocal effects apart from the source water signal. We hypothesized that it’s likely that mangrove plants, having a greater proportion of water traveling simplastically, would have a longer water pathway from the xylem to the stomatal pore than hammock plants. According to the Peclet effect, this would cause lower isotopic enrichment of leaf water in mangroves compared to those of hammock species. This would explain previous measurements where δ18O of stem cellulose of mangrove was not as enriched as the expected. To test our hypothesis, a transect was selected across the 2 vegetation types (mangroves and hammocks). The parameters measured where: transpiration, temperature of the leaf, ambient temperature, relative humidity, δ18O of vapor, δ18O of stem water and δ18O of leaf water. With those parameters we calculated the effective length of the water pathway from the xylem to the stomatal pore. The results confirmed our hypothesis that mangrove leaves have a longer water pathway from the xylem to the stomatal pore compared to hammock leaves. The next step is to study how we could incorporate this knowledge of different length of water pathway between halophytes and glycophytes to better correlate the oxygen isotopic signature of stem cellulose and its source water. The ultimate goal is to make possible the use of the δ18O of stem cellulose as a tool to proxy sea level rise.

  5. The Relationship between Phytoplankton Distribution and Water Column Characteristics in North West European Shelf Sea Waters

    PubMed Central

    Davidson, Keith; Bolch, Christopher J. S.; Brand, Tim D.; Narayanaswamy, Bhavani E.

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the “Ellett Line” cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN∶DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN∶DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of growth at most stations and depths. PMID:22479533

  6. [Heavy metals distribution characteristics and risk assessment of water below an electroplating factory].

    PubMed

    Hang, Xiao-Shuai; Wang, Huo-Yan; Zhou, Jian-Min

    2008-10-01

    Surface water and shallow groundwater within the flow of an electroplating factory was analyzed in order to study the resulting impact. The analysis method of ICP-AES was used to analyze content of zinc, manganese, chromium, copper and nickel in surface water and groundwater samples. The results indicate acidic pollutants of zinc, manganese, chromium, copper and nickel were discharged from the factory with concentrations of 1.34, 3.77, 28.1, 6.40 and 9.37 mg x L(-1), respectively; and pH was 2.32. They all exceeded permissible levels according to Integrated Wastewater Discharge Standard except zinc. Factory discharge is responsible for the longitudinal distribution characteristics of heavy metals in the stream water downstream from the factory. Heavy metals variations in the well water do not suggest they were affected by heavy metals in the stream, indicating that the migration rates of heavy metals in soils were relatively low. Risk assessment shows surface water quality significantly deteriorated. Nickel and manganese in the stream water exceeded the standard levels seriously, and chromium and copper in some samples were also above Grade III standard levels according to Environmental Quality Standard for Surface Water. Moreover, all studied heavy metals in 14 groundwater samples measured within drinking water standard, except manganese in 4 groundwater samples, which were Grade IV according to Quality Standard for Ground water. PMID:19143363

  7. [Effects of irrigation and planting pattern on winter wheat water consumption characteristics and dry matter production].

    PubMed

    Dong, Hao; Chen, Yu-Hai; Zhou, Xun-Bo

    2013-07-01

    Taking high-yield winter wheat cultivar 'Jimai 22' as test material, a field experiment was conducted in 2008-2010 to study the effects of different irrigation and planting modes on the water consumption characteristics and dry matter accumulation and distribution of winter wheat. Three planting patterns (uniform row, wide-narrow row, and furrow) and four irrigation schedules (no irrigation, W0; irrigation at jointing stage, W1; irrigation at jointing and anthesis stages, W2; and irrigation at jointing, anthesis, and milking stages, W3; with 60 mm per irrigation) were installed. With increasing amount of irrigation, the total water consumption and the ratio of irrigation water to total water consumption under different planting patterns all increased, while the soil water consumption and its ratio to total water consumption decreased significantly. As compared with W0, the other three irrigation schedules had a higher dry matter accumulation after anthesis and a higher grain yield, but a lower water use efficiency (WUE). Under the same irrigation schedules, furrow pattern had higher water consumption ratio, grain yield, and WUE. Taking the grain yield and WUE into consideration, furrow pattern combined with irrigation at jointing and anthesis stages would be the optimal water-saving and planting modes for the winter wheat production in North China Plain. PMID:24175516

  8. Simultaneous measurements of shape characteristics and radar backscattering of a water surface in a rain field

    NASA Astrophysics Data System (ADS)

    Liu, Ren; Liu, Xinan; Duncan, James H.

    2015-11-01

    The characteristics of radar backscattering from a water surface that is stimulated by a rain field are studied at laboratory scale. The experiment is carried out in a 1.22-m by 1.22-m water pool with a water depth of 0.3 m. Simulated raindrops are generated by an array of 22-gauge needles that are attached to the bottom of a water reservoir located above the pool. A two-dimensional horizontal translational motion is added to the water reservoir in order to vary the drop impact location for each needle during each experimental run. A cinematic Laser-Induced-Florescence (LIF) technique is used to measure the water surface shape while radar backscattering from the water surface is simultaneously recorded by a dual-polarized, ultra-wide band radar. Both the radar return intensity and the water surface shape are measured for a range of rain rates and a range of radar incidence angles. The relationship between the geometric features of the water surface shape and the radar return are explored. The support of the National Science Foundation, Division of Atmospheric and Oceanic Sciences, under grant ARC0962107 is gratefully acknowledged.

  9. Effects of water addition on soil arthropods and soil characteristics in a precipitation-limited environment

    NASA Astrophysics Data System (ADS)

    Chikoski, Jennifer M.; Ferguson, Steven H.; Meyer, Lense

    2006-09-01

    We investigated the effect of water addition and season on soil arthropod abundance and soil characteristics (%C, %N, C:N, moisture, pH). The experimental design consisted of 24 groups of five boxes distributed within a small aspen stand in Saskatchewan, Canada. The boxes depressed the soil to create a habitat with suitable microclimate for soil arthropods, and by overturning boxes we counted soil arthropods during weekly surveys from April to September 1999. Soil samples were collected at two-month intervals and water was added once per week to half of the plots. Of the eleven recognizable taxonomic units identified, only mites (Acari) and springtails (Collembola) responded to water addition by increasing abundance, whereas ants decreased in abundance with water addition. During summer, springtail numbers increased with water addition, whereas pH was a stronger determinant of mite abundance. In autumn, springtails were positively correlated with water and negatively correlated with mites, whereas mite abundance was negatively correlated with increasing C:N ratio, positively correlated to water addition, and negatively correlated with springtail abundance. Although both mite and springtail numbers decreased in autumn with a decrease in soil moisture, mites became more abundant than springtails suggesting a predator-prey (mite-springtail) relationship. Water had a significant effect on both springtails and mites in summer and autumn supporting the assertion that prairie soil communities are water limited.

  10. Pore-size dependence and characteristics of water diffusion in slitlike micropores

    NASA Astrophysics Data System (ADS)

    Diallo, S. O.

    2015-07-01

    The temperature dependence of the dynamics of water inside microporous activated carbon fibers (ACF) is investigated by means of incoherent elastic and quasielastic neutron-scattering techniques. The aim is to evaluate the effect of increasing pore size on the water dynamics in these primarily hydrophobic slit-shaped channels. Using two different micropore sizes (˜12 and 18 Å, denoted, respectively, ACF-10 and ACF-20), a clear suppression of the mobility of the water molecules is observed as the pore gap or temperature decreases. This suppression is accompanied by a systematic dependence of the average translational diffusion coefficient Dr and relaxation time <τ0> of the restricted water on pore size and temperature. The observed Dr values are tested against a proposed scaling law, in which the translational diffusion coefficient Dr of water within a porous matrix was found to depend solely on two single parameters, a temperature-independent translational diffusion coefficient Dc associated with the water bound to the pore walls and the ratio θ of this strictly confined water to the total water inside the pore, yielding unique characteristic parameters for water transport in these carbon channels across the investigated temperature range.

  11. Microgravity Alters the Physiological Characteristics of Escherichia coli O157:H7 ATCC 35150, ATCC 43889, and ATCC 43895 under Different Nutrient Conditions

    PubMed Central

    Kim, H. W.; Matin, A.

    2014-01-01

    The aim of this study is to provide understanding of microgravity effects on important food-borne bacteria, Escherichia coli O157:H7 ATCC 35150, ATCC 43889, and ATCC 43895, cultured in nutrient-rich or minimal medium. Physiological characteristics, such as growth (measured by optical density and plating), cell morphology, and pH, were monitored under low-shear modeled microgravity (LSMMG; space conditions) and normal gravity (NG; Earth conditions). In nutrient-rich medium, all strains except ATCC 35150 showed significantly higher optical density after 6 h of culture under LSMMG conditions than under NG conditions (P < 0.05). LSMMG-cultured cells were approximately 1.8 times larger than NG-cultured cells at 24 h; therefore, it was assumed that the increase in optical density was due to the size of individual cells rather than an increase in the cell population. The higher pH of the NG cultures relative to that of the LSMMG cultures suggests that nitrogen metabolism was slower in the latter. After 24 h of culturing in minimal media, LSMMG-cultured cells had an optical density 1.3 times higher than that of NG-cultured cells; thus, the higher optical density in the LSMMG cultures may be due to an increase in both cell size and number. Since bacteria actively grew under LSMMG conditions in minimal medium despite the lower pH, it is of some concern that LSMMG-cultured E. coli O157:H7 may be able to adapt well to acidic environments. These changes may be caused by changes in nutrient metabolism under LSMMG conditions, although this needs to be demonstrated in future studies. PMID:24487539

  12. Physiological performance of an Alaskan shrub (Alnus fruticosa) in response to disease (Valsa melanodiscus) and water stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At northern latitudes, plants are being exposed to multiple climate-related stresses as warming temperatures push plants beyond the physiological limits of their current range. Our study focused on two stresses related to the warming and drying of the Alaskan boreal forest: drought and disease. We e...

  13. Landscape characteristics impacts on water quality of urban lowland catchments: monitoring the Amsterdam city area

    NASA Astrophysics Data System (ADS)

    Yu, Liang; van der Vlugt, Corné; Rozemeijer, Joachim; Broers, Hans Peter; van Breukelen, Boris; Ouboter, Maarten; Stuyfzand, Pieter

    2015-04-01

    In Dutch lowland polder systems, groundwater quality significantly contributes to surface water quality. This process is influenced by landscape characteristics such as topography, geology, and land use types. In this study, 23 variables were selected for 144 polder catchments, including groundwater and surface water solute concentrations (TN, TP, NH4+, NO3-, HCO3-, SO42-, Ca2+, Cl-), seepage rate in mm per year, elevation, paved area percentage, surface water area percentage, and soil types (calcite, humus and lutum percentage). The spatial patters in groundwater and surface water quality can largely be explained by groundwater seepage rates in polders and partly by artificial redistribution of water via the regional surface water system. High correlations (R2 up to 0.66) between solutes in groundwater and surface water revealed their probable interaction. This was further supported by results from principal component analysis (PCA) and linear regression. The PCA distinguished four factors that were related to a fresh groundwater factor, seepage rate factor, brackish groundwater factor and clay soil factor. Nutrients (TP, TN, NH4+ and NO3-) and SO42- in surface water bodies are mainly determined by groundwater quality combined with seepage rate, which is negatively related to surface water area percentage and elevation of the catchment. This pattern is more obvious in deep urban lowland catchments. Relatively high NO3- loads more tend to appear in catchments with high humus, but low calcite percentage soil type on top, which was attributed to clay soil type that was expressed by calcite percentage in our regression. Different from nitrogen contained solutes, TP is more closely related to fresh groundwater quality than to seepage rate. Surface water Cl- concentration has a high relation with brackish groundwater. Due to the artificial regulation of flow direction, brackish inlet water from upstream highly influences the chloride load in surface water bodies downstream, especially in infiltrated urban catchments. We conclude that, apart from artificial regulation, groundwater has significant impacts on surface water quality in the polders. Especially in low-lying urban catchments surface water solute concentrations like TP, TN, NH4+, HCO3-, SO42-, and Ca2+ can be predicted by groundwater characteristics. These results suggest that groundwater quality plays a crucial role in understanding and improving surface water quality in regulated lowland catchments.

  14. Benchmarking the WaterGAP3 global hydrology model in reproducing streamflow characteristics

    NASA Astrophysics Data System (ADS)

    Eisner, Stephanie; Flörke, Martina

    2015-04-01

    Global hydrological models are key tools to understand and assess the current state of global freshwater resources. They facilitate quantifying the degree of human interference on the natural hydrological regime and help to assess impacts of global and climate change on water resources. Large to global scale hydrologic simulation is, however, prone to large uncertainties which originate from spatially distributed input data (atmospheric forcing and land surface parameters) and, in particular, the (often) simplified physical process representation. Most large-scale modelling approaches are constrained by the implicit assumption that one single model structure is globally valid and the fact that the modeler lacks location-specific knowledge. In order to evaluate the quality of water availability estimates and to quantify the uncertainty associated with these estimates, it is thus essential to examine systematically where and why large scale hydrological models perform well or poor in reproducing observed streamflow characteristics. This study presents an extensive benchmarking study of the WaterGAP3 (Water - Global Assessment and Prognosis) model to reproduce observed monthly stream characteristics on the basis of more than 2400 observed streamflow records globally. WaterGAP3 is a grid-based conceptual water balance model operating on a 5 arc minute global grid. The model is explicitly designed to account for human interference on the natural hydrologic regime through flow regulation and water abstractions. Monthly simulated discharges for the period 1958-2010 are evaluated against observations based on three complementary performance metrics. Subsequently, model performance is assessed against a set of generic catchment descriptors supported by available global datasets which characterize climatic and physiographic conditions in the individual catchments as well as the degree of human alteration of the hydrologic regime. These relationships between catchment characteristics and model efficiencies help to detect inadequacies in model structure as well as in the underlying input data, thus set the stage for further model development.

  15. Rowing Physiology.

    ERIC Educational Resources Information Center

    Spinks, W. L.

    This review of the literature discusses and examines the methods used in physiological assessment of rowers, results of such assessments, and future directions emanating from research in the physiology of rowing. The first section discusses the energy demands of rowing, including the contribution of the energy system, anaerobic metabolism, and the…

  16. Water use and physiology of the riparian tree species Eucalyptus victrix in the semi-arid Pilbara region of Western Australia

    NASA Astrophysics Data System (ADS)

    Pfautsch, S.; Keitel, C.; Adams, M. A.; Turnbull, T.

    2009-04-01

    We examined the water use and physiology of trees growing in a riparian community within the seasonally arid Pilbara region of north-western Australia. This region is arid during the winter months, but monsoonal during summer (November to April). Maximum monthly mean temperatures in summer exceed 40 °C and are c. 25 °C during the winter months. The Millstream study site is located on a section of the Fortescue River system along the base of the Chichester Range c. 100km south of Karratha. This system creates a unique landscape in the Pilbara as it forms several large permanent pools. These pools are maintained by springs from an aquifer beneath the alluvial plain. The groundwater from this aquifer is used as a public water supply for towns in the west Pilbara but industrial development and a growing population will place greater demand on this aquifer. Changes to the local hydrology may have dramatic effects on the local plant community, dominated variously by stands of Eucalyptus victrix (Coolibah) and Eucalyptus camaldulensis (River red gum). This study seeks to understand the dependence of the Millstream riparian ecosystem on the height of the aquifer and to characterise the water use and physiology of Eucalyptus victrix. We used a number of techniques to determine the hydraulic and photosynthetic status of the tree canopy, including isotope, sap flow, water-potential and gas exchange measurements. Initial results from this study show: a) Soil water d18O and d2H is strongly enriched towards the surface, which coincides with a strong increase in salinity. The water source accessed by these trees has been identified by d18O and d2H analysis of xylem water. d18O and d2H were additionally analysed in atmospheric and leaf water pools. b) Sap flow in Coolibah trees shows a unique pattern of sharp early morning rise to a plateau maintained throughout the hottest part of the day, followed by a sharp decline in flow late in the afternoon. c) Leaf water potential follows a similar pattern to sap flow with changes of c. 1 MPa (from c. 0.5 MPa to 1.5 MPa) within 45 min at the beginning and the end of the light period. d) Stomatal conductance appears to be disconnected from this pattern and shows a slower opening phase in the morning, no discernible midday-afternoon depression and a slower closure in the evening, well after night-fall. Combining isotopic, sap flow, physiological and meteorologic information will help to understand how these riparian ecosystems function and how they respond to rapid environmental changes, both natural and introduced by human activities.

  17. The Epiphytic Fern Elaphoglossum luridum (Fée) Christ. (Dryopteridaceae) from Central and South America: Morphological and Physiological Responses to Water Stress

    PubMed Central

    Minardi, Bruno Degaspari; Voytena, Ana Paula Lorenzen; Randi, Áurea Maria

    2014-01-01

    Elaphoglossum luridum (Fée) Christ. (Dryopteridaceae) is an epiphytic fern of the Atlantic Forest (Brazil). Anatomical and physiological studies were conducted to understand how this plant responds to water stress. The E. luridum frond is coriaceus and succulent, presenting trichomes, relatively thick cuticle, and sinuous cell walls in both abaxial and adaxial epidermis. Three treatments were analyzed: control, water deficit, and abscisic acid (ABA). Physiological studies were conducted through analysis of relative water content (RWC), photosynthetic pigments, chlorophyll a fluorescence, and malate content. No changes in RWC were observed among treatments; however, significant decreases in chlorophyll a content and photosynthetic parameters, including optimal irradiance (Iopt) and maximum electron transport rate (ETRmax), were determined by rapid light curves (RLC). No evidence of crassulacean acid metabolism (CAM) pathway was observed in E. luridum in response to either water deficit or exogenous application of ABA. On the other hand, malate content decreased in the E. luridum frond after ABA treatment, seeming to downregulate malate metabolism at night, possibly through tricarboxylic acid (TCA) cycle regulation. PMID:25386618

  18. Dna synthesis in the urinary-tract epithelium of the rat induced by laparotomy and by intraperitoneal injection of distilled water, physiological saline and lycopodium spores.

    PubMed Central

    Herbertson, B. M.; King, A. J.; Allen, J.

    1982-01-01

    The tritiated thymidine labelling index (LI) of the epithelium of the ureters and urinary bladder of young male Wistar rats is substantially increased 18 h after a simple laparotomy incision. A similar highly significant increase (P less than 0.001) has been observed after a single i.p. injection of various materials, including (a) distilled water, (b) 0.5% glycogen in physiological saline, and (c) 1% suspension of lycopodium spores in physiological saline. In each instance an aseptic inflammatory response develops in the peritoneal cavity. Reasons are given supporting the concept that a mitogen is produced from a constituent of the inflammatory exudate in the peritoneal cavity and that the factor reaches the affected epithelium by direct diffusion. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7150509

  19. Determination of virtual water content of rice and spatial characteristics analysis in China

    NASA Astrophysics Data System (ADS)

    Zhang, L. J.; Yin, X. A.; Zhi, Y.; Yang, Z. F.

    2014-06-01

    China is a water-stressed country, and agriculture consumes the bulk of its water resources. Assessing the virtual water content (VWC) of crops is one important way to develop efficient water management measures to alleviate water resource conflicts among different sectors. In this research, the VWC of rice, a major crop in China, is taken as the research object. China covers a vast land area, and the VWC of rice varies widely between different regions. The VWC of rice in China is assessed and the spatial characteristics are also analysed. The total VWC is the total volume of freshwater both consumed and affected by pollution during the crop production process, including both direct and indirect water use. Prior calculation frameworks of the VWC of crops did not contain all of the virtual water content of crops. In addition to the calculation of green, blue and grey water - the direct water in VWC - the indirect water use of rice was also calculated, using an input-output model. The percentages of direct green, blue, grey and indirect water in the total VWC of rice in China were found to be 43.8, 28.2, 27.6, and 0.4%. The total VWC of rice generally showed a roughly three-tiered distribution, and decreased from southeast to northwest. The higher values of direct green water usage were mainly concentrated in Southeast and Southwest China, while the values were relatively low in Northwest China and Inner Mongolia. The higher direct blue water values were mainly concentrated in the eastern and southern coastal regions and Northwest China, and low values were mainly concentrated in Southwest China. Grey water values were relatively high in Shanxi and Guangxi provinces and low in Northeast and Northwest China. The regions with high values for indirect water were randomly distributed but the regions with low values were mainly concentrated in Northwest and Southwest China. For the regions with relatively high total VWC the high values of blue water made the largest contribution, although for the country as a whole the direct green water is the most important contributor.

  20. Research on the characteristics of the water quality of rainwater runoff from green roofs.

    PubMed

    Gong, Kena; Wu, Qing; Peng, Sen; Zhao, Xinhua; Wang, Xiaochen

    2014-01-01

    This paper investigates the water quality characteristics of rainwater runoff from dual-substrate-layer green roofs in Tianjin, China. The data were collected from four different assemblies and three types of simulated rains. The storm-water runoff quality was monitored from early June through late October 2012 and from July through late November 2013. The results revealed that the runoff water quality would be improved to some extent with the ageing of green roofs and that the quality retention rate better reflected the pollutant retention capacity of the green roof than the pollutant concentration in the runoff water. The investigation clearly demonstrated that green roofs also effectively reduced the chemical oxygen demand and turbidity value and neutralised acid rain to stabilise the pH of the runoff. PMID:25325545

  1. Characteristics of Sensible Heat, Water Vapor, and CO2 Fluxes Over a Rice Paddy

    NASA Astrophysics Data System (ADS)

    Hsieh, C.

    2007-12-01

    An eddy-correlation system consisting of a sonic anemometer and an open-gas analyzer was used for understanding the characteristics of sensible heat, water vapor, and CO2 fluxes over a subtropical rice paddy in Taipei, Taiwan. The results showed that about 35-40 percent of net radiation was used for latent heat flux, 13 percent for sensible heat flux, and the rest (about 50 percent) was absorbed by the water and soil in the rice paddy. Based on the background measurements (where no rice was growing), it was found that CO2 emission from the soil surface was small, just about 0.074 micro mole per square meter per second. We also found that the relative turbulent transport efficiencies of heat to water and heat to carbon dioxide depended on Bowen ratio. However, in average, heat, water vapor, and carbon dioxide were transported with the same rate above this rice paddy.

  2. Water absorption characteristics of novel Cu/LDPE nanocomposite for use in intrauterine devices.

    PubMed

    Xia, Xianping; Cai, Shuizhou; Hu, Junhui; Xie, Changsheng

    2006-11-01

    Intrauterine devices (IUDs), especially the copper-containing IUDs (Cu-IUDs), are one of the worldwide used forms for birth control, owing to their advantages of long-lasting and high efficacy, economy, safety, and reversibility. However, it is not perfect for the existing Cu-IUDs; some shortcomings related to its side effects have not been overcome yet. For this reason, a new Cu-IUDs material, the copper/low-density polyethylene (Cu/LDPE) nanocomposite, has been developed in our research team. The structure and water uptake characteristics of this new Cu-IUDs material have been investigated by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and gravimetric analysis in this paper. The results of XRD, SEM, EDS, and FT-IR show three important outcomes associated with the structure of the nanocomposite. First, the nanocomposite is hybrid of the polymer and the copper nanoparticles (nano-Cu). Second, porosities, nano-Cu aggregates, and primary alcohol (R--CH(2)--OH) are existed in the nanocomposite. Third, the nano-Cu aggregates are distributed uniformly in the polymer matrix in general. The results of Gravimetric analysis, which associated with the water uptake characteristics of the nanocomposite, exhibit that the water absorption behavior of the nanocomposite obeys the classical diffusion theory very well, the water uptake of the nanocomposite increases with the increasing of the nano-Cu loading, and that the water uptake ability of the nanocomposite with 15.0 wt % nano-Cu (50 nm in diameter) is about 150 times larger than that of the base resin and about 45 times higher than that of the Cu/LDPE microcomposite with 15.0 wt % copper microparticles (5 microm in diameter). These water uptake characteristics are mainly attributed to the structure of the Cu/LDPE composites and the size effect of the nano-Cu. PMID:16637033

  3. Water Vapor Desorption Characteristics of Honeycomb Type Sorption Element Composed of Organic Sorbent

    NASA Astrophysics Data System (ADS)

    Inaba, Hideo; Kida, Takahisa; Horibe, Akihiko; Kaneda, Makoto; Okamoto, Tamio; Seo, Jeong-Kyun

    This paper describes the water vapor desorption characteristics of honeycomb shape type sorbent element containing new organic sorbent of the bridged complex of sodium polyacrylate. The transient experiments in which the dry air was passed into the honeycomb type sorbent element sorbed water vapor were carried out under various conditions of air velocity, temperature, relative humidity and honeycomb length. The obtained data for desorption process were compared with those for sorption process. Finally, Sherwood number of mass transfer of the organic sorbent for desorption process was derived in terms of Reynolds number, modified Stefan number and non-dimensional honeycomb length.

  4. Mixing characteristics of turbulent water vapour jets measured using an isokinetic sampling probe

    NASA Astrophysics Data System (ADS)

    Baskaya, S.; Gilchrist, A.; Fraser, S. M.

    Horizontal turbulent water vapour (steam) jets were discharged into ambient air from a circular convergent nozzle under unchoked/choked and saturated/superheated nozzle exit conditions, resulting in two-phase (liquid and vapour), two-fluid (air and water) condensing free jets. Flow properties and mixing characteristics have been measured with the aid of an isokinetic sampling probe arrangement. Radial and axial profiles of air and steam mass flow rates and mass fractions were measured from which entrainment, centreline decay and half-width spreading rates were calculated and compared with data from the literature. Overall, the mixing characteristics of the condensing jets are very similar to those of non-condensing jets extensively reported in the literature.

  5. Effects of diesel engine speed and water content on emission characteristics of three-phase emulsions.

    PubMed

    Lin, Cherng-Yuan; Wang, Kuo-Hua

    2004-01-01

    The effects of water content of three-phase emulsions and engine speed on the combustion and emission characteristics of diesel engines were investigated in this study. The results show that a larger water content of water-in oil (W/O) and oil-in-water-in-oil (O/W/O) emulsion caused a higher brake specific fuel consumption (bsfc) value and a lower O2, as well as a lower NOx emission, but a larger CO emission. The increase in engine speed resulted in an increase of bsfc, exhaust gas temperature, fuel-to-air ratio, CO2 emission and a decrease of NOx, CO emission, and smoke opacity. Because of the physical structural differences, the three-phase O/W/O emulsions were observed to produce a higher exhaust gas temperature, a higher emulsion viscosity and a lower CO emission, in comparison with that of the two-phase W/O emulsion. In addition, the use of W/O emulsions with water content larger than 20% may cause diesel engines to shut down earlier than those running on O/W/O emulsions with the same water content. Hence, it is suggested that the emulsions with water content larger than 20% are not suitable for use as alternative fuel for diesel engines. PMID:15137702

  6. Characteristics of streamer discharge development between the dielectric-coated sphere-plane electrodes in water

    SciTech Connect

    Zhu Taiyun; Yang Lanjun; Jia Zhijie; Zhang Qiaogen

    2008-12-01

    This paper presents the characteristics of the streamer discharge development between the dielectric-coated sphere-plane electrodes in water. In order to study the streamer propagation mechanism, the factors such as polarities, water conductivity, and ambient pressure were taken into consideration. Experimental results demonstrate that the water conductivity and amplitude of applied voltage both have a great influence on mean velocity and brightness of the streamer. When the ambient pressure decreases from 0.1 to 0.0065 MPa, the pressure has little influence on the mean velocities of the streamer in both distilled and tap water for fast streamer. The existence of dielectric coating causes a lower initiation voltage of the streamer for negative polarity than that for positive one. Also, the 10% breakdown voltage (U{sub 10%}) is decreased by 20% under the pressure of 0.0065 MPa than that under the pressure of 0.1 MPa in distilled water, while the U{sub 10%} is almost the same under different pressures in tap water. Based on the analysis of the discharge images and current waveforms as well as the above experimental results, it can be concluded that the streamer propagation is composed of the generation of the microbubbles and the discharge in the bubbles. For subsonic streamer, the generation of the bubbles is more likely a thermal process, whereas for supersonic streamer, the ionization and dissociation of water molecules in high electric field are involved in the bubble generation process.

  7. The water withdraws and spectral characteristic analysis of back groundsurface features in Zengcheng City

    NASA Astrophysics Data System (ADS)

    Gao, Ai; Xia, Lihua

    2008-10-01

    Many achievements in studies of extracting water have been made in the past ten years.According to the foundation of remote sensing and spectrum theory, the general extracting principal of remote sensing information is introduced. Zengcheng was rich in water resources, and it is an idel back garden of Guangzhou city. Therefore, it is important to use the water resources rationally in Zengcheng.TM image dated 10 November 2006 was elected in this paper.Both interpreted maps were analyzed and managed by ENVI and ArcGIS software. Single-band threshold method, the relationship between spectrum, vegetation index and water index method were used in this paper. At last, Water index method was considered to be the most suitable one after a comparative analysis.In this paper landscape types within the study area were classified into (1) farmland, (2)forest land, (3)urban Inhabitant land and other land,(4)orchard land, (5)unused land, (6)water, with the help of Land cover map 2006 of Zengcheng. A reconnaissance survey of the study area was made to correlate the image characteristics and ground features by the standard technique of human-computer 'dialogue' interpretation.According to the foundation of remote sensing and spectrum theory, a model of water body extraction is set up in this paper.

  8. Environmental characteristics and water quality of hydrologic benchmark network stations in the west-central United States, 1963-95

    USGS Publications Warehouse

    Clark, Melanie L.; Eddy-Miller, C. A.; Mast, M. Alisa

    2000-01-01

    This report describes the environmental characteristics and water-quality characteristics of 14 benchmark basins in the west-central United States. The information was compiled to aide in the interpretation and application of historical water-quality data collected through the Hydrologic Benchmark Network Program.

  9. Environmental characteristics and water quality of hydrologic benchmark network stations in the western United States, 1963-95

    USGS Publications Warehouse

    Mast, M. Alisa; Clow, David W.

    2000-01-01

    This report describes the environmental characteristics and water-quality characteristics of 12 hydrologic benchmark network streams in the Western United States. This information was compiled to aide in the interpretation and application of water-quality data collected as part of the Hydrologic Benchmark Network Program.

  10. The Physiologically Difficult Airway

    PubMed Central

    Mosier, Jarrod M.; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C.

    2015-01-01

    Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation. PMID:26759664

  11. The Physiologically Difficult Airway.

    PubMed

    Mosier, Jarrod M; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C

    2015-12-01

    Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation. PMID:26759664

  12. Chemical and physical characteristics of water in estuaries of Texas, October 1976-September 1978

    USGS Publications Warehouse

    Fisher, J.C.

    1982-01-01

    This report presents basic data on the chemical and physical characteristics of water in the estuaries of Texas for the period October 1976-September 1978. The properties or constituents that are measured in the field are dissolved oxygen (DO), specific conductance, temperature, pH, and transparency by Secchi disk. Analyses conducted in the laboratory include the principal inorganic ions, biochemical oxygen demand (BOD), total organic carbon (TOC), ammonium, nitrite, nitrate, and total phosphate. (USGS)

  13. Chemical characteristics of waters in Karst Formations at the Oak Ridge Y-12 Plant

    SciTech Connect

    Shevenell, L.A.

    1994-11-01

    Several waste disposal sites are located adjacent to or on a karst aquifer composed of the Cambrian Maynardville Limestone (Cmn) and the Cambrian Copper Ridge Dolomite (Ccr) at the U.S. Department of Energy Oak Ridge Y-12 Plant in Oak Ridge, TN. Highly variable chemical characteristics (i.e., hardness) can indicate that the portion of the aquifer tapped by a particular well is subject to a significant quick-flow component where recharge to the system is rapid and water levels and water quality change rapidly in response to precipitation events. Water zones in wells at the Y-12 Plant that exhibit quick-flow behavior (i.e., high hydraulic conductivity) are identified based on their geochemical characteristics and variability in geochemical parameters, and observations made during drilling of the wells. The chemical data used in this study consist of between one and 20 chemical analyses for each of 102 wells and multipart monitoring zones. Of these 102 water zones, 10 were consistently undersaturated with respect to calcite suggesting active dissolution. Repeat sampling of water zones shows that both supersaturation and undersaturation with respect to dolomite occurs in 46 water zones. Twelve of the zones had partial pressure of CO{sub 2} near atmospheric values suggesting limited interaction between recharge waters and the gases and solids in the vadose zone and aquifer, and hence, relatively short residence times. The preliminary data suggest that the Cmn is composed of a complicated network of interconnected, perhaps anastomosing, cavities. The degree of interconnection between the identified cavities is yet to be determined, although it is expected that there is a significant vertical and lateral interconnection between the cavities located at shallow depths in the Cnm throughout Bear Creek Valley and the Y-12 Plant area.

  14. [Analysis on characteristics of red tide in Fujian coastal waters during the last 10 years].

    PubMed

    Li, Xue-Ding

    2012-07-01

    There were 161 red tide events collected during the last 10 years from 2001 to 2010 in Fujian coastal waters. Comprehensive analysis was performed using statistical methods and the results indicated the following characteristics of the temporal and spatial distribution of red tide in Fujian coastal waters: (1) Outbreaks of red tide often occurred between April and September, and the peak period was in May and June. Most red tide events lasted for 2 to 4 days, and the affected area was below 50 square kilometers. The first outbreak of red tide tended to occur earlier in recent years, and the lasting time became longer. (2) There were 20 species of organisms causing the red tides in Fujian coastal waters, among which 10 species were Bacillariophyta, 9 species were Dinophyta and 1 species was Protozoa. Prorocentrum donghaiense was the most frequent cause of red tides, followed by Noctiluca scintillans, Skeletonema costatum and Chaetoceros sp.. The species caused red tides obeyed the succession law and there were always new species involved. (2) In terms of spatial distribution, outbreaks of red tides mainly occurred in the coastal waters of Ningde, Fuzhou and Xiamen. The species causing red tides were Prorocentrum donghaiense and Noctiluca in the coastal waters in the north of Pingtan, Fujian Province, Skeletonema costatum and Chaetoceros in the coastal waters in the south of Pingtan, Fujian Province. The comprehensive analysis of the characteristics of red tides during the last 10 years is expected to provide scientific and reasonable basis for the prevention, reduction and forecast of red tides in Fujian coastal waters. PMID:23002593

  15. Performance Evaluation of Four-Parameter Models of the Soil-Water Characteristic Curve

    PubMed Central

    Taha, Mohd Raihan

    2014-01-01

    Soil-water characteristic curves (SWCCs) are important in terms of groundwater recharge, agriculture, and soil chemistry. These relationships are also of considerable value in geotechnical and geoenvironmental engineering. Their measurement, however, is difficult, expensive, and time-consuming. Many empirical models have been developed to describe the SWCC. Statistical assessment of soil-water characteristic curve models found that exponential-based model equations were the most difficult to fit and generally provided the poorest fit to the soil-water characteristic data. In this paper, an exponential-based model is devised to describe the SWCC. The modified equation is similar to those previously reported by Gardner (1956) but includes exponential variable. Verification was performed with 24 independent data sets for a wide range of soil textures. Prediction results were compared with the most widely used models to assess the model's performance. It was proven that the exponential-based equation of the modified model provided greater flexibility and a better fit to data on various types of soil. PMID:24971384

  16. Physiological and isotopic characteristics of nitrogen fixation by hyperthermophilic methanogens: Key insights into nitrogen anabolism of the microbial communities in Archean hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Nishizawa, Manabu; Miyazaki, Junichi; Makabe, Akiko; Koba, Keisuke; Takai, Ken

    2014-08-01

    Hyperthermophilic hydrogenotrophic methanogens are considered to be one of the most predominant primary producers in hydrogen (H2)-abundant hydrothermal environments in the present-day ocean and throughout the history of the Earth. However, the nitrogen sources supporting the development of microbial communities in hydrothermal environments remain poorly understood. We have investigated, for the first time, methanogenic archaea commonly found in deep-sea hydrothermal environments to understand their physiological properties (growth kinetics, energetics, and metal requirements) and isotopic characteristics during the fixation of dinitrogen (N2), which is an abundant but less-bioavailable compound in hydrothermal fluids. Culture experiments showed that Methanocaldococcus strain (Mc 1-85N) (Topt = 85 °C) and Methanothermococcus strain (Mt 5-55N) (Topt = 55 °C) assimilated N2 and ammonium, but not nitrate. Previous phylogenetic studies have predicted that the Methanocaldococcus and Methanothermococcus lineages have nitrogenases, key enzymes for N2 fixation, with biochemically uncharacterised active site metal cofactors. We showed that Mt 5-55N required molybdenum for the nitrogenase to function, implying a molybdenum-bearing cofactor in the strain. Molybdenum also stimulated diazotrophic (i.e., N2-fixing) growth of Mc 1-85N, though further experiments are required to test whether the strain contains a molybdenum-dependent nitrogenase. Importantly, Mc 1-85N exhibited an apparently lower requirement of and higher tolerance to molybdenum and iron than Mt 5-55N. Furthermore, both strains produced more 15N-depleted biomass (-4‰ relative to N2) than that previously reported for diazotrophic photosynthetic prokaryotes. These results demonstrate that diazotrophic hyperthermophilic methanogens can be broadly distributed in seafloor and subseafloor hydrothermal environments, where the availability of transition metals is variable and where organic carbon, organic nitrogen, and ammonium are generally scarce. The emergence and function of diazotrophy, coupled with methanogenesis, in the early Earth is also consistent with the nitrogen isotopic records of 3.5 billion-year-old hydrothermal deposits.

  17. Stress induced by hooking, net towing, elevated sea water temperature and air in sablefish: Lack of concordance between mortality and physiological measures of stress

    USGS Publications Warehouse

    Davis, M.W.; Olla, B.L.; Schreck, C.B.

    2001-01-01

    In a series of laboratory studies designed to simulate bycatch processes, sablefish Anoplopoma fimbria were either hooked for up to 24 h or towed in a net for 4 h and then subjected to an abrupt transfer to elevated sea water temperature and air. Mortality did not result from hooking or net towing followed by exposure to air, but increased for both capture methods as fish were exposed to elevated temperatures, reflecting the magnifying effect of elevated temperature on mortality. Hooking and exposure to air resulted in increased plasma cortisol and lactate concentrations, while the combination of hooking and exposure to elevated temperature and air resulted in increased lactate and potassium concentrations. In fish that were towed in a net and exposed to air, cortisol, lactate, potassium and sodium concentrations increased, but when subjected to elevated temperature and air, no further increases occurred above the concentrations induced by net towing and air, suggesting a possible maximum of the physiological stress response. The results suggest that caution should be exercised when using physiological measures to quantify stress induced by capture and exposure to elevated temperature and air, that ultimately result in mortality, since the connections between physiological stress and mortality in bycatch processes remain to be fully understood.

  18. Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Seibert, J.; Lembo, A. J.; Steenhuis, T. S.; Walter, M. T.

    2008-10-01

    Spatial patterns of water chemistry along stream networks can be quantified using synoptic or "snapshot" sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

  19. Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Seibert, J.; Lembo, A. J.; Steenhuis, T. S.; Walter, M. T.

    2008-06-01

    Spatial patterns of water chemistry along stream networks can be quantified using synoptic or "snapshot" sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

  20. Location and site characteristics of the ambient ground-water-quality-monitoring network in West Virginia

    USGS Publications Warehouse

    Kozar, M.D.; Brown, D.P.

    1995-01-01

    Ground-water-quality-monitoring sites have been established in compliance with the 1991 West Virginia "Groundwater Protection Act." One of the provisions of the "Groundwater Protection Act" is to conduct ground-water sampling, data collection, analyses, and evaluation with sufficient frequency so as to ascertain the characteristics and quality of ground water and the sufficiency of the ground- water protection programs established pursuant to the act (Chapter 20 of the code of West Virginia, 1991, Article 5-M). Information for 26 monitoring sites (wells and springs) which comprise the Statewide ambient ground-water-quality-monitoring network is presented. Areas in which monitoring sites were needed were determined by the West Virginia Division of Environmental Protection, Office of Water Resources in consultation with the U.S. Geological Survey (USGS). Initial sites were chosen on the basis of recent hydrogeologic investigations conducted by the USGS and from data stored in the USGS Ground Water Site Inventory database. Land use, aquifer setting, and areal coverage of the State are three of the more important criteria used in site selection. A field reconnaissance was conducted to locate and evaluate the adequacy of selected wells and springs. Descriptive information consisting of site, geologic, well construction, and aquifer-test data has been compiled. The 26 sites will be sampled periodically for iron, manganese, most common ions (for example, calcium, magnesium, sodium, potassium, sulfate, chloride, bicarbonate), volatile and semivolatile organic compounds (for example, pesticides and industrial solvents), and fecal coliform and fecal streptococcus bacteria. Background information explaining ground-water systems and water quality within the State has been included.

  1. Hydrologic and water-quality characteristics of a Wetland receiving wastewater effluent in St. Joseph, Minnesota

    USGS Publications Warehouse

    Brown, Rob G.; Stark, James R.

    1989-01-01

    Hydrologic and water-quality characteristics were determined for a wetland being used for tertiary treatment of wastewater in St. Joseph, Minnesota. The wetland consists of spruce-tamarack fen and a cattail marsh, with the wastewater being discharged into the fen, and the fen draining into the marsh. The wetland is underlain by flat-lying glacial outwash that ranges from 0 to greater than 20 m in thickness. Horizontal ground-water movement in the outwash aquifer is toward the wetland from the south, east, and west. There is a strong upward vertical hydraulic gradient (about 0.1) in the ground-water flow system beneath and around the wetland. Regionally, the glacial-outwash aquifer is unconfined, but it is confined or partly confined locally by peat deposits under the wetland. Analysis of the hydrologic balance of the fen from October 1985 through September 1986 indicates that the inflow was 44 percent ground water, 38 percent wastewater, 11 percent runoff (storm sewer), and 7 percent precipitation. The fen outflow was 93 percent surface water and 7 percent evapotranspiration. Inflow to the marsh was 74 percent surface water, 21 percent ground water, and 5 percent precipitation. Outflow from the marsh was 94 percent surface water and 6 percent evapotranspiration. Wastewater contributed 74,996, and 81 percent of the total suspended solids, total phosphorus, and total ammonia plus organic nitrogen in the fen, respectively. Other chemical inputs were from the storm sewer, ground water, and atmospheric deposition. The fen was found to retain 34, 14, and 14 percent of the suspended solids, total phosphorus, and total ammonia plus organic nitrogen, respectively. The marsh retained 44, 18, and 22 percent of these three constituents, respectively.

  2. Characteristic of Local Boiling Heat Transfer of Ammonia / Water Binary Mixture on the Plate Type Evaporator

    NASA Astrophysics Data System (ADS)

    Okamoto, Akio; Arima, Hirofumi; Kim, Jeong-Hun; Akiyama, Hirokuni; Ikegami, Yasuyuki; Monde, Masanori

    Ocean thermal energy conversion (OTEC) and discharged thermal energy conversion (DTEC) are expected to be the next generation energy production systems. Both systems use a plate type evaporator, and ammonia or ammonia/water mixture as a working fluid. It is important to clarify heat transfer characteristic for designing efficient power generation systems. Measurements of local boiling heat transfer coefficients and visualization were performed for ammonia /water mixture (z = 0.9) on a vertical flat plate heat exchanger in a range of mass flux (7.5 - 15 kg/m2s), heat flux (15 - 23 kW/m2), and pressure (0.7 - 0.9 MPa). The result shows that in the case of ammonia /water mixture, the local heat transfer coefficients increase with an increase of vapor quality and mass flux, and decrease with an increase of heat flux, and the influence of the flow pattern on the local heat transfer coefficient is observed.

  3. Transient characteristics of a grooved water heat pipe with variable heat load

    NASA Technical Reports Server (NTRS)

    Jang, Jong Hoon

    1990-01-01

    The transient characteristics of a grooved water heat pipe were studied by using variable heat load. First, the effects of the property variations of the working fluid with temperature were investigated by operating the water heat pipe at several different temperatures. The experimental results show that, even for the same heat input profile and heat pipe configuration, the heat pipe transports more heat at higher temperature within the tested temperature range. Adequate liquid return to the evaporator due to decreasing viscosity of the working fluid permits continuous vaporization of water without dry-out. Second, rewetting of the evaporator was studied after the evaporator had experienced dry-out. To rewet the evaporator, the elevation of the condenser end was the most effective way. Without elevating the condenser end, rewetting is not straight-forward even with power turned off unless the heat pipe is kept at isothermal condition for sufficiently long time.

  4. Soil-Water Characteristic Curves of Red Clay treated by Ionic Soil Stabilizer

    NASA Astrophysics Data System (ADS)

    Cui, D.; Xiang, W.

    2009-12-01

    The relationship of red clay particle with water is an important factor to produce geological disaster and environmental damage. In order to reduce the role of adsorbed water of red clay in WuHan, Ionic Soil Stabilizer (ISS) was used to treat the red clay. Soil Moisture Equipment made in U.S.A was used to measure soil-water characteristic curve of red clay both in natural and stabilized conditions in the suction range of 0-500kPa. The SWCC results were used to interpret the red clay behavior due to stabilizer treatment. In addition, relationship were compared between the basic soil and stabilizer properties such as water content, dry density, liquid limit, plastic limit, moisture absorption rate and stabilizer dosages. The analysis showed that the particle density and specific surface area increase, the dehydration rate slows and the thickness of water film thins after treatment with Ionic Soil Stabilizer. After treatment with the ISS, the geological disasters caused by the adsorbed water of red clay can be effectively inhibited.

  5. Characteristics of impact-driven high-speed liquid jets in water

    NASA Astrophysics Data System (ADS)

    Matthujak, A.; Kasamnimitporn, C.; Sittiwong, W.; Pianthong, K.; Takayama, K.; Milton, B. E.

    2013-03-01

    This paper describes a preliminary investigation of the characteristics of high-speed water jets injected into water from an orifice. The high-speed jets were generated by the impact of a projectile launched by a horizontal single-stage powder gun and submerged in a water test chamber. The ensuing impact-driven high-speed water jets in the water were visualized by the shadowgraph technique, and the images were recorded by a high-speed digital video camera. The processes following such jet injection into water, the jet-induced shock waves, shock wave propagation, the bubble behavior, bubble collapse-induced rebound shock waves and bubble cloud re-generation were observed. Peak over-pressures of about 24 and 35 GPa measured by a Polyvinylidence difluoride (PVDF) piezoelectric film pressure sensor were generated by the jet impingement and the bubble impingement, respectively. The peak over-pressure was found to decrease exponentially as the stand-off distance between the PVDF pressure sensor and the nozzle exit increases.

  6. Postimpoundment survey of water-quality characteristics of Raystown Lake, Huntingdon and Bedford Counties, Pennsylvania

    USGS Publications Warehouse

    Williams, Donald R.

    1978-01-01

    Water-quality data, collected from May 1974 to September 1976 at thirteen sites within Raystown Lake and in the inflow and outflow channels, define the water-quality characteristics of the lake water and the effects of impoundment on the quality of the lake outflow. Depth-profile measurements show Raystown Lake to be dimictic. Thermal stratification is well developed during the summer. Generally high concentrations of dissolved oxygen throughout the hypolimnion during thermal stratification, low phytoplankton concentrations, and small diel fluctuations of dissolved oxygen, pH, and specific conductance indicate that the lake is low in nutrients, or oligotrophic. Algal assays of surface samples indicate that orthophosphate was a growth-limiting nutrient. The diatoms (Chrysophyta) were the dominant phytoplankton group found through-out the study period. The lake waters contained very low populations of zooplankton. Fecal coliform and fecal streptococcus densities measured throughout the lake indicated no potentially dangerous areas of water-contact recreation. The most apparent effect that the impoundment had on water quality was the removal of nutrients, particularly orthophosphate, through phytoplankton uptake and sediment deposition.

  7. Types and characteristics of drinking water for hydration in the elderly.

    PubMed

    Casado, Ángela; Ramos, Primitivo; Rodríguez, Jaime; Moreno, Norberto; Gil, Pedro

    2015-01-01

    The role of hydration in the maintenance of health is increasingly recognized. Hydration requirements vary for each person, depending on physical activity, environmental conditions, dietary patterns, alcohol intake, health problems, and age. Elderly individuals have higher risk of developing dehydration than adults. Diminution of liquid intake and increase in liquid losses are both involved in causing dehydration in the elderly. The water used for drinking is provided through regular public water supply and the official sanitary controls ensure their quality and hygiene, granting a range of variation for most of its physical and chemical characteristics, being sometimes these differences, though apparently small, responsible for some disorders in sensitive individuals. Hence, the advantages of using bottled water, either natural mineral water or spring water, are required by law to specify their composition, their major components, and other specific parameters. It is essential to take this into account to understand the diversity of indications and favorable effects on health that certain waters can offer. PMID:24915336

  8. Drinking water quality in Nepal's Kathmandu Valley: a survey and assessment of selected controlling site characteristics

    NASA Astrophysics Data System (ADS)

    Warner, Nathaniel R.; Levy, Jonathan; Harpp, Karen; Farruggia, Frank

    2008-03-01

    Water was sampled from over 100 sources in Nepal’s Kathmandu Valley, including municipal taps, dug wells, shallow-aquifer tube wells, deep-aquifer tube wells, and dhunge dharas (or stone spouts, public water sources that capture groundwater or surface water). Information was gathered on user preference and site and well characteristics, and water was examined for indicators of contamination from sewage, agriculture, or industry. Most problematic were total coliform and Escherichia coli bacteria, which were present in 94 and 72% of all the water samples, respectively. Contamination by nitrate, ammonia and heavy metals was more limited; nitrate and ammonia exceeded Nepali guidelines in 11 and 45% of the samples, respectively. Arsenic and mercury exceeded WHO guidelines in 7 and 10% of the samples, respectively, but arsenic never exceeded the less strict Nepali guideline. Significant differences existed in contamination levels between types of sources; dug wells and dhunge dharas, being the shallowest, were the most contaminated by bacteria and nitrate; deep-aquifer tube wells were the most contaminated by arsenic. Whereas E. coli concentrations decreased with depth, iron and ammonia concentrations increased with depth. These relationships account for people choosing to drink water with higher levels of bacterial contamination based on its superior (non-metallic) taste and appearance.

  9. Geological-hydrogeochemical characteristics of a “silver spring” water source (the Lozovy ridge)

    NASA Astrophysics Data System (ADS)

    Ivanova, I. S.; Bragin, I. V.; Chelnokov, G. A.; Bushkareva, K. Yu; Shvagrukova, E. V.

    2016-03-01

    Geological and hydrogeological characteristics of the Lozovy ridge (Southern Primorye) are studied, as far as karst phenomena are widely distributed within its boundaries. Water-bearing rocks of the karst water source “Silver Spring” (“Serebryany Klyuch”), which is located near the bottom of the “Bear’s fang” (“Medvezhiy klyk”) cave, are investigated. It is found that karst rocks are presented by calcite (CaCO3), and an accessory mineral is barite (BaSO4). It is determined that among the trace elements forming the composition of carbonate water-bearing rocks the maximum concentrations are typical for Sr, Ba, Fe, Al, Za, Mn, Cu, and Ni. Also, the chemical composition of the waters taken from the “Silver Spring” water source is studied. These waters are fresh, hydrocarbonate, calcium, and weakly alkaline. Among the elements of the spring, such elements as Sr, Ba, Fe, Al, Zn, Mn, Cu, and Ni have the maximum concentration. The other elements have concentrations less than 1 µg/l.

  10. A STUDY ON VARIABILITY CHARACTERISTIC OF WATER QUALITY IN TIDAL AREA OF URBAN RIVER

    NASA Astrophysics Data System (ADS)

    Yamakado, Yasuki

    In order to clarify variability characteristic of water quality in tidal area of urban river, results of field observation at ordinary water (about the water quality change before and after dredging) and rainfall in the tidal area of the Nihonbashi River are reported in this paper. From the results of field observation, following results are obtained;1) The mean value of dissolved oxygen saturation of all layers decreased by 25.8% at the spring tide, by 20.4% at the neap tide before and after dredging. 2) BOD concentration decreased and T-P concentration increased after dredging. T-N concentration decreased after dredging at the low tide. 3) When total rainfall was 10.5mm in 7 hours, value of dissolved oxygen saturation did not change in all layers, and it increased by 20% after 7 days. 4) During daytime both air temperature and water temperature increased. On the other hand, during nighttime water temperature decreased in spite of air temperature increased. 5) Water velocity repeated reverse flow and uniform flow during a hour period.

  11. Benthic invertebrate population characteristics as affected by water quality in coal-bearing regions of Tennessee

    USGS Publications Warehouse

    Bradfield, A.D.

    1986-01-01

    Benthic invertebrate and water quality data collected during previous U.S. Geological Survey studies to provide background hydrologic information on streams draining Tennessee coal reserves, were evaluated to identify possible relations between stream biota and water quality. Linear regressions produced low correlation coefficients relating the number of taxa/sample, total number of organisms/sample, sample diversity, and percentage composition of selected orders of invertebrates, with average water quality parameter values available at sampling stations (r is < 0.62 at p=0.05). Analyses of these data by linear regressions explained little of the variability in benthic invertebrate samples primarily because the distributions of benthic organisms along environmental gradients are nonlinear. Variability in substrate characteristics in the study area and seasonal insect emergence patterns also complicated interpretation of these data. However, analysis of variance tests did indicate significant trends towards reduced number of taxa, number of organisms, and sample diversity at stations with relatively poor water quality conditions. Decreasing percentage composition of Ephemeroptera was generally accompanied by an increase in percent Diptera at stations with higher water quality constituent concentrations and acidic pH ( > than 0.6 units). These trends indicate significant differences in benthic communities at sites with evidence of more severe land use impacts. Additional data on benthic invertebrates, water quality , and physical habitat conditions, along with analyses of data using multivariate statistical methods are needed to define ecological relations between specific groups of invertebrates and environmental conditions. (Author 's abstract)

  12. Macrophytes in shallow lakes: relationships with water, sediment and watershed characteristics

    PubMed Central

    Kissoon, La Toya T; Jacob, Donna L; Hanson, Mark A; Herwig, Brian R; Bowe, Shane E; Otte, Marinus L

    2013-01-01

    We examined macrophyte-environment relationships in shallow lakes located within the Prairie Parkland and Laurentian Mixed Forest provinces of Minnesota. Environmental variables included land cover within lake watersheds, and within-lake, water and sediment characteristics. CCA indicated that sediment fraction smaller than 63 μm (f<63), open water area, turbidity, and percent woodland and agricultural cover in watersheds were significant environmental variables explaining 36.6% of variation in macrophyte cover. When Province was added to the analysis as a spatial covariate, these environmental variables explained 30.8% of the variation in macrophyte cover. CCA also indicated that pH, f<63, percent woodland cover in watersheds, open water area, emergent vegetation area, and organic matter content were significant environmental variables explaining 43.5% of the variation in macrophyte biomass. When Province was added to the analysis as a spatial covariate, these environmental variables explained 39.1% of the variation in macrophyte biomass. The f<63 was the most important environmental variable explaining variation for both measures of macrophyte abundance (cover and biomass) when Province was added as a spatial covariate to the models. Percent woodland in watersheds, turbidity, open water area, and Ca+Mg explained 34.5% of the variation in macrophyte community composition. Most species showed a negative relationship with turbidity and open water area except for Potamogeton richardsonii, Stuckenia pectinata, and filamentous algae. Our study further demonstrates the extent to which macrophyte abundance and community composition are related to site- and watershed-scale variables including lake morphology, water and sediment characteristics, and percent land cover of adjacent uplands. PMID:23997402

  13. Water quality characteristics along the course of the Huangpu River (China).

    PubMed

    Yang, Hong-jun; Shen, Zhe-min; Zhang, Jin-ping; Wang, Wen-hua

    2007-01-01

    Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industrial development, the pollution of the Huangpu River has become serious recently. The biological oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), oil, phenol and suspended solids (SS) were lower in the upstream sites than in the downstream sites, indicating pollutants being input along its course. Water quality was the worst in the Yangpu site, near the center of Shanghai City. Dissolved oxygen (DO) content was less than 2 mg/L in the site of Yangpu in July. Among relations between thirteen characteristics, relations between BOD, DO, TN, TP, NH4(+)-N, NO3(-)-N and the count of total bacteria or Escherichia coli were significant and interdependent. Inner relationships between these main characteristics in the Huangpu River were studied. High nutrient concentration led to growth of microorganisms, including E. coli. Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body, and DO was a key factor for nitrification-denitrification process of nitrogen. In the Yangpu site, DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July. Low DO concentration will decrease nitrification rate. Nitrification need at higher DO value than other organic substrate oxidation. Consequently, river water contains low NO3(-)-N values with high amounts of TN and NH4+-N there. This will block the self-purification of surface water, by decreasing the rate of nitrification-denitrification transformation process in the water body. PMID:18062417

  14. Dynamic moisture sorption characteristics of xerogels from water-swellable oligo(oxyethylene) lignin derivatives.

    PubMed

    Passauer, Lars; Struch, Marlene; Schuldt, Stefan; Appelt, Joern; Schneider, Yvonne; Jaros, Doris; Rohm, Harald

    2012-11-01

    Highly swellable lignin derivatives were prepared by cross-linking of oxidatively preactivated spruce organosolv lignin (OSL) with poly(ethylene) glycol diglycidyl ether (PEGDGE). The lignin gels obtained are considered to be an environmentally friendly alternative to synthetic hydrogels and superabsorbents and represent a novel type of lignin based functional materials. For their application, it is not only the absorption of water in terms of hydrogel swelling that plays an important role, but also the adsorption and retention of moisture by the corresponding xerogels. To reveal the mechanisms involved in moistening and reswelling of the lignin gels, the interaction of water vapor with lyophilized xerogels was investigated and compared with sorption characteristics of parent lignin. The chemical structure of PEGDGE-modified lignin was investigated using attenuated total reflectance Fourier-transformed infrared spectroscopy and selective aminolysis and was related to its sorption and swelling characteristics. Bound and free water in hydrogels was determined by differential scanning calorimetry and by measuring the free swelling capacity of the gels. Moisture sorption of OSL and PEGDGE-modified lignin xerogels was determined using dynamic vapor sorption analysis. In order to determine monolayer and multilayer sorption parameters, sorption data were fitted to the Brunauer-Emmett-Teller and the Guggenheim-Anderson-de Boer model. Swelling properties of the hydrogels and moisture sorption of the corresponding xerogels were found to be strongly dependent on the degree of chemical modification with PEGDGE: Total and free water content of hydrogels decrease with increasing cross-linking density; on the other hand, water bound in hydrogels and moisture sorption of xerogels at high levels of water activity strongly increase, presumably because of the hydration of hydrophilic oligo(oxyethylene) and oligo(oxyethylene) glycol substituents, which lead to moisture diffusion into the xerogel matrix, plasticization, and swelling of the gels. PMID:23075458

  15. [Characteristics of stable isotopes in soil water under several typical land use patterns on Loess Tableland].

    PubMed

    Cheng, Li-Ping; Liu, Wen-Zhao

    2012-03-01

    In this study, the precipitation over the Loess Tableland in Changwu County of Shaanxi Province and the soil water in 0-20 m loess profiles under different land use patterns on the Tableland were sampled, and their isotope compositions were analyzed, aimed to understand the characteristics of stable isotopes in the soil water and the mechanisms of the soil water movement. In the study area, the equation of the local meteoric water line (LMWL) was deltaD = 7.39 delta180 + 4.34 (R2 = 0.94, n = 71), and the contents of the stable isotopes in the precipitation had an obvious seasonal variation of high in winter and spring and low in summer and autumn. The contents of the stable isotopes in the soil water were fell on the underside of the LMWL, and higher than those in the precipitation from July to October, indicating that the soil water was mainly replenished by the precipitation with lower stable isotope contents in summer and autumn. In the soil profiles of different land use patterns, the stable isotope contents in soil water tended to be the same with the increasing soil depth; while under the same land use patterns, the water's stable isotope composition in shallow soil layers changed greatly with time, but changed less with increasing depth. Through the comparison of the stable isotope contents in precipitation and in soil water, it was observed that the piston flow and preferential flow on the Tableland were coexisted in the process of precipitation infiltration, and the occurrence of the preferential flow had a certain relation with land use pattern. Generally, the soil desiccation caused by the negative water balance resulted from the artificial plantations of high water consumption could reduce the probability of preferential flow occurrence, whereas the precipitation infiltration in the form of preferential flow could easily occur on the farmland or natural grassland so that the soil water in deep layers or the ground water could be replenished. PMID:22720607

  16. Physiology Of Drowning: A Review.

    PubMed

    Bierens, Joost J L M; Lunetta, Philippe; Tipton, Mike; Warner, David S

    2016-03-01

    Drowning physiology relates to two different events: immersion (upper airway above water) and submersion (upper airway under water). Immersion involves integrated cardiorespiratory responses to skin and deep body temperature, including cold shock, physical incapacitation, and hypovolemia, as precursors of collapse and submersion. The physiology of submersion includes fear of drowning, diving response, autonomic conflict, upper airway reflexes, water aspiration and swallowing, emesis, and electrolyte disorders. Submersion outcome is determined by cardiac, pulmonary, and neurological injury. Knowledge of drowning physiology is scarce. Better understanding may identify methods to improve survival, particularly related to hot-water immersion, cold shock, cold-induced physical incapacitation, and fear of drowning. PMID:26889019

  17. Red spruce physiology and growth in response to elevated CO[sub 2], water stress and nutrient limitations

    SciTech Connect

    Samuelson, L.J.

    1992-01-01

    Spruce-fir ecosystems of the eastern United States interest scientists because of reported changes in population growth. This research examined the growth and physical responses of red spruce seedlings (Picea rubens Sarg.) to change in atmospheric CO[sub 2], water and nutrient availability to determine the response of this species to potential climatic changes. Red spruce seedlings were grown from seed for 1 year in ambient (374 ppm) or elevated (713 ppm) CO[sub 2] in combination with low or high soil fertility treatment, and well-watered or water-stressed conditions. Red spruce seedlings grown with limited nutrient and water availability increased growth in elevated CO[sub 2] as did seedlings grown with high soil fertility treatment and ample water. At 12 months of age, elevated CO[sub 2]-grown seedlings had greater dry weight, height, diameter and specific leaf weight than ambient CO[sub 2[minus

  18. Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary

    NASA Astrophysics Data System (ADS)

    Casper, A. F.

    2005-05-01

    The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

  19. Evaluation of Characteristics of Surface which Influence the Initiation of Freezing of Supercooled Water

    NASA Astrophysics Data System (ADS)

    Okawa, Seiji; Saito, Akio

    It is essential to clarify the supercooling phenomenon, as it is one of the important problem for carrying out the ice storage system, effectively. In this report, the effect of the characteristics of the surface as a heterogeneous nucleation of water was investigated. Experiments on freezing of supercooled water were carried out using various kinds of heat transfer surfaces. The type of the surface used in the experiments were, electrolyticaly polished copper surface, buffed copper surface, gold-plated surface, nickel-plated, porous copper surface, silicone surface, Teflon surface and acrylic surface. The results indicate that the probability of freezing is highly dependent upon the characteristics of the surface. However, by considering the characteristics of the surface as a density of the spots having a high ability of nucleation, it was found that the distribution of the probability of freezing for each surface can be expressed using a parameter τ. A physical meaning of the parameter τ was discussed and suggested as a function of the surface energy and the surface roughness.

  20. Response of soybean rhizosphere communities to human hygiene water addition as determined by community level physiological profiling (CLPP) and terminal restriction fragment length polymorphism (TRFLP) analysis

    NASA Technical Reports Server (NTRS)

    Kerkhof, L.; Santoro, M.; Garland, J.

    2000-01-01

    In this report, we describe an experiment conducted at Kennedy Space Center in the biomass production chamber (BPC) using soybean plants for purification and processing of human hygiene water. Specifically, we tested whether it was possible to detect changes in the root-associated bacterial assemblage of the plants and ultimately to identify the specific microorganism(s) which differed when plants were exposed to hygiene water and other hydroponic media. Plants were grown in hydroponics media corresponding to four different treatments: control (Hoagland's solution), artificial gray water (Hoagland's+surfactant), filtered gray water collected from human subjects on site, and unfiltered gray water. Differences in rhizosphere microbial populations in all experimental treatments were observed when compared to the control treatment using both community level physiological profiles (BIOLOG) and molecular fingerprinting of 16S rRNA genes by terminal restriction fragment length polymorphism analysis (TRFLP). Furthermore, screening of a clonal library of 16S rRNA genes by TRFLP yielded nearly full length SSU genes associated with the various treatments. Most 16S rRNA genes were affiliated with the Klebsiella, Pseudomonas, Variovorax, Burkholderia, Bordetella and Isosphaera groups. This molecular approach demonstrated the ability to rapidly detect and identify microorganisms unique to experimental treatments and provides a means to fingerprint microbial communities in the biosystems being developed at NASA for optimizing advanced life support operations.

  1. Effects of the water extract of Gynura bicolor (Roxb. & Willd.) DC on physiological and immune responses to Vibrio alginolyticus infection in white shrimp (Litopenaeus vannamei).

    PubMed

    Hsieh, Shu-Ling; Wu, Chih-Chung; Liu, Chun-Hung; Lian, Juang-Lin

    2013-07-01

    Gynura bicolor (Roxb. & Willd.) DC is widely distributed in certain areas of Asia and is very popular in vegetarian cuisine in Taiwan. To investigate the regulatory roles of G. bicolor in various functions in crustaceans, we examined innate non-specific immune responses (including total hemocyte count (THC), phenoloxidase activity (PO), respiratory bursts (RBs), and superoxide dismutase (SOD) activity), physiological responses (including haemolymph glucose, lactate, and lipids), and gene expressions (including prophenoloxidase (proPO), lipopolysaccharide- and b-1,3-glucan-binding protein (LGBP), and peroxinectin (PE) mRNA transcripts) to the pathogen Vibrio alginolyticus in white shrimp (Litopenaeus vannamei) that were individually injected with the water extract from G. bicolor at 2, 4, and 8 μg g(-1). Results indicated that PO, RBs, SOD activity, proPO, LGBP, and PE mRNA transcripts of shrimps receiving the water extract of G. bicolor at 2, 4, and 8 μg g(-1) significantly increased after challenge with V. alginolyticus for 96 h. However, no significant difference in the THC was seen at any dose. L. vannamei injected with the water extract of G. bicolor at all doses respectively maintained lower glucose, lactate, and lipid levels in response to V. alginolyticus challenge at 12-36, 24-36, and 24-48 h. Survival rates at 24-72 h of L. vannamei that received G. bicolor at any dose was significantly higher than those of shrimp that received saline. It was concluded that the water extract of G. bicolor can maintain physiological homeostasis and enhance immunity against V. alginolyticus infection in L. vannamei. PMID:23603309

  2. Study of Cold Heat Energy Release Characteristics of Flowing Ice Water Slurry in a Pipe

    NASA Astrophysics Data System (ADS)

    Inaba, Hideo; Horibe, Akihiko; Ozaki, Koichi; Yokota, Maki

    This paper has dealt with melting heat transfer characteristics of ice water slurry in an inside tube of horizontal double tube heat exchanger in which a hot water circulated in an annular gap between the inside and outside tubes. Two kinds of heat exchangers were used; one is made of acrylic resin tube for flow visualization and the other is made of stainless steel tube for melting heat transfer measurement. The result of flow visualization revealed that ice particles flowed along the top of inside tube in the ranges of small ice packing factor and low ice water slurry velocity, while ice particles diffused into the whole of tube and flowed like a plug built up by ice particles for large ice packing factor and high velocity. Moreover, it was found that the flowing ice plug was separated into numbers of small ice clusters by melting phenomenon. Experiments of melting heat transfer were carried out under some parameters of ice packing factor, ice water slurry flow rate and hot water temperature. Consequently, the correlation equation of melting heat transfer was derived as a function of those experimental parameters.

  3. Nutrient characteristics of the water masses and their seasonal variability in the eastern equatorial Indian Ocean.

    PubMed

    Sardessai, S; Shetye, Suhas; Maya, M V; Mangala, K R; Prasanna Kumar, S

    2010-01-01

    Nutrient characteristics of four water masses in the light of their thermohaline properties are examined in the eastern Equatorial Indian Ocean during winter, spring and summer monsoon. The presence of low salinity water mass with "Surface enrichments" of inorganic nutrients was observed relative to 20 m in the mixed layer. Lowest oxygen levels of 19 microM at 3 degrees N in the euphotic zone indicate mixing of low oxygen high salinity Arabian Sea waters with the equatorial Indian Ocean. The seasonal variability of nutrients was regulated by seasonally varying physical processes like thermocline elevation, meridional and zonal transport, the equatorial undercurrent and biological processes of uptake and remineralization. Circulation of Arabian Sea high salinity waters with nitrate deficit could also be seen from low N/P ratio with a minimum of 8.9 in spring and a maximum of 13.6 in winter. This large deviation from Redfield N/P ratio indicates the presence of denitrified high salinity waters with a seasonal nitrate deficit ranging from -4.85 to 1.52 in the Eastern Equatorial Indian Ocean. PMID:20547419

  4. Liquid water transport characteristics of porous diffusion media in polymer electrolyte membrane fuel cells: A review

    NASA Astrophysics Data System (ADS)

    Liu, Xunliang; Peng, Fangyuan; Lou, Guofeng; Wen, Zhi

    2015-12-01

    Fundamental understanding of liquid water transport in gas diffusion media (GDM) is important to improve the material and structure design of polymer electrolyte membrane (PEM) fuel cells. Continuum methods of two-phase flow modeling facilitate to give more details of relevant information. The proper empirical correlations of liquid water transport properties, such as capillary characteristics, water relative permeability and effective contact angle, are crucial to two phase flow modeling and cell performance prediction. In this work, researches on these properties in the last decade are reviewed. Various efforts have been devoted to determine the water transport properties for GDMs. However, most of the experimental studies are ex-situ measurements. In-situ measurements for GDMs and extending techniques available to study the catalyst layer and the microporous layer will be further challenges. Using the Leverett-Udell correlation is not recommended for quantitative modeling. The reliable Leverett-type correlation for GDMs, with the inclusion of the cosine of effective contact angle, is desirable but hard to be established for modeling two-phase flow in GDMs. A comprehensive data set of liquid water transport properties is needed for various GDM materials under different PEM fuel cell operating conditions.

  5. Predicting stream-water quality using catchment and soil chemical characteristics.

    PubMed

    Billett, M F; Cresser, M S

    1992-01-01

    The distribution and chemistry of soils in 10 upland catchments in NE Scotland have been used to develop a means of predicting minimum, maximum and mean concentrations of calcium and hydrogen ions in streams. The approach is based on the control of stream-water chemistry by soil chemical properties. Stream-water chemistry was monitored over a two-year period. Each catchment was surveyed and soils sampled to characterize the chemistry of the main soil units. Stream-water chemical parameters are related to the chemical characteristics of the upper and lower soil horizons in the catchments. The contribution of each soil unit is assessed using randomly generated flow paths. Soil chemistry is weighted according to the distribution of soils in the immediate vicinity of the stream. In this paper the approach is largely confined to the prediction of minimum, maximum and mean concentrations of calcium ions in stream waters. In the longer term, the approach may have the potential to predict what effects changes in soil chemistry and management practice (drainage, ploughing) will have on water quality in upland catchments. PMID:15091967

  6. Water landing characteristics of a model of a winged reentry vehicle

    NASA Technical Reports Server (NTRS)

    Stubbs, S. M.

    1972-01-01

    Proposed manned space shuttle vehicles are expected to land on airport runways. In an emergency situation, however, the vehicle may be required to land on water. A 1/10-scale dynamic model of a winged reentry vehicle was investigated to determine the water landing characteristics. Two configurations of the proposed vehicle were studied. Configuration 1 had a 30 deg negative dihedral of the stabilizer-elevon surface whereas configuration 2 had a 30 deg positive dihedral. Results indicate that the maximum normal accelerations for configurations 1 and 2 when landing in calm water were approximately 8g and 6g, respectively, and the maximum longitudinal accelerations were approximately 5g and 3g, respectively. A small hydroflap was needed to obtain satisfactory calm-water landings with configuration 2, whereas configuration 1 gave good landings without a hydroflap. All landings made in rough water resulted in unsatisfactory motions. For landings made in three different wave sizes, both configurations dived. The maximum normal accelerations for configurations 1 and 2 when landing in waves were -10.1g and -18.7g, respectively, and the maximum longitudinal accelerations for both configurations were approximately 13g.

  7. Regulatory Physiology

    NASA Technical Reports Server (NTRS)

    Lane, Helen W.; Whitson, Peggy A.; Putcha, Lakshmi; Baker, Ellen; Smith, Scott M.; Stewart, Karen; Gretebeck, Randall; Nimmagudda, R. R.; Schoeller, Dale A.; Davis-Street, Janis

    1999-01-01

    As noted elsewhere in this report, a central goal of the Extended Duration Orbiter Medical Project (EDOMP) was to ensure that cardiovascular and muscle function were adequate to perform an emergency egress after 16 days of spaceflight. The goals of the Regulatory Physiology component of the EDOMP were to identify and subsequently ameliorate those biochemical and nutritional factors that deplete physiological reserves or increase risk for disease, and to facilitate the development of effective muscle, exercise, and cardiovascular countermeasures. The component investigations designed to meet these goals focused on biochemical and physiological aspects of nutrition and metabolism, the risk of renal (kidney) stone formation, gastrointestinal function, and sleep in space. Investigations involved both ground-based protocols to validate proposed methods and flight studies to test those methods. Two hardware tests were also completed.

  8. Growth, physiology and yield of durum wheat (Triticum durum) treated with sewage sludge under water stress conditions

    PubMed Central

    Boudjabi, Sonia; Kribaa, Mohammed; Chenchouni, Haroun

    2015-01-01

    In arid and semi-arid areas, low soil fertility and water deficit considerably limit crop production. The use of sewage sludge as an organic amendment could contribute to the improvement of soil fertility and hence the agronomic production. The study aims to highlight the behaviour of durum wheat to the application of sewage sludge associated with water stress. The assessment focused on morphophysiological parameters of the wheat plant and yield. Under greenhouse conditions, the variety Mohamed Ben Bachir was treated by four water stress levels (100 %, 80 %, 50 % and 30 %). Each stress level comprised five fertilizer treatments: 20, 50 and 100 t/ha of dry sludge, 35 kg/ha of urea, and a control with no fertilization. Results revealed a significant loss in water content and chlorophyll a in leaves. Water stress negatively affected the development of wheat plants by reducing significantly seed yield, leaf area and biomass produced. Plant’s responses to water stress manifested by an accumulation of proline and a decrease in total phosphorus. However, the increasing doses of sewage sludge limited the effect of water stress. Our findings showed an increase in the amount of chlorophyll pigments, leaf area, total phosphorus, biomass and yield. In addition, excessive accumulation of proline (1.11 ± 1.03 µg/g DM) was recorded as a result of the high concentration of sludge (100 t/ha DM). The application of sewage sludge is beneficial for the wheat crop, but the high accumulation of proline in plants treated with high dose of sludge suggests to properly consider this fact. The application of sludge should be used with caution in soils where water is limited. Because the combined effect of these two factors could result in a fatal osmotic stress to crop development. PMID:26417365

  9. [Effects of irrigation amount on morphological characteristics and water use of Jatropha curcas].

    PubMed

    Yang, Qi-Liang; Zhang, Jing; Liu, Xiao-Gang; Liu, Yan-Wei; Yang, Ju-Rui

    2014-05-01

    Jatropha curcas is the most promising energy tree, and soil moisture is the key factor which affects the seedling quality and water use efficiency of J. curcas. With aims to evaluate the effect of different irrigation amount on growth, morphological characteristics and water use of J. curcas, a pot experiment was conducted with four irrigation amounts, i. e., W1:472.49 mm, W2: 228.79 mm, W3:154.18 mm and W4:106.93 mm, respectively. Compared with W1 treatment, the leaf area and stem cross-section area of base significantly decreased in W2, W3 and W4 treatments, but Huber value significantly increased, which could improve the efficiency of water transfer from root to shoot, thus enhance the capability of resistance to drought stress. Compared with W, treatment, the healthy index of J. curcas seedlings decreased slightly in W2 treatment but significantly decreased in W3 and W4 treatments. Hence, the irrigation amount from 228.79 to 472.49 mm was beneficial to increase the healthy index of J. curcas seedlings. Compared with W1 treatment, irrigation water was saved by 67.4% in W3 treatment, and the total dry mass and evapotranspiration significantly decreased by 17.4% and 68.6%, and the irrigation water use efficiency and total water use efficiency increased by 153.2% and 163.2%, respectively. In the condition of this study, the irrigation amount of 154.18 mm was beneficial to increase water use efficiency. PMID:25129933

  10. Have we been ignoring physiological plasticity and genetic variation in stomatal function as a significant source of error in models of water and carbon fluxes?

    NASA Astrophysics Data System (ADS)

    Wertin, T. M.; Wolz, K.; Richter, K.; Adorbo, M.; Betzelberger, A. M.; Leakey, A.

    2013-12-01

    Accurately predicting plant and ecosystem function across climatic and ecological gradients requires properly parameterized models of both net photosynthetic assimilation of CO2 and stomatal conductance. Photosynthesis models have been parameterized to account for physiological plasticity and genetic variation for decades. However, models describing physiological plasticity or genetic variation in the sensitivity of stomatal conductance to net photosynthetic CO2 assimilation (A), relative humidity (RH), and atmospheric [CO2] have rarely, if ever, been applied. There is no mechanistic basis for the prevailing assumption that models of stomatal conductance can share a universal parameterization for all C3 species. Twelve species of temperate trees were grown in a common garden to test species-specific sensitivity of stomatal conductance to A, RH and [CO2]. Additionally, a Salix and a Populus genotype, grown at three locations throughout the Eastern US in biofuels trails, were measured at three times during the growing season to test for temporal and spatial effects. Soybean was also grown at eight ozone concentrations to test for physiological plasticity in stomatal function. Laboratory-based gas exchange measurements were used to parameterize the widely used Ball et al. (1987) model of stomatal conductance and the Farquhar et al. (1980) model of photosynthesis. These models were coupled to each other and a leaf energy balance model in order to predict in situ leaf CO2 and water fluxes which were compared against field measurements. There was significant physiological plasticity and genetic variation in the sensitivity of stomatal conductance to A, RH and [CO2]. This was reflected in significant variation in parameters of the Ball et al. (1987) model, with the key slope parameter (m) ranging from more than 4-fold. Context-specific parameterization of this widely used stomatal conductance model reduced error in predictions of in situ leaf A and gs by up to 59%, compared to the commonly used generic parameterization (m = 10, g0 = 0). This suggests that parameterization of stomatal conductance models to reflect physiological plasticity and genetic variation in function would be an effective method to improve the accuracy of plant and ecosystem models that are key tools in the study of global environmental change and sustainable agriculture.

  11. Investigating onychophoran gas exchange and water balance as a means to inform current controversies in arthropod physiology.

    PubMed

    Clusella-Trullas, Susana; Chown, Steven L

    2008-10-01

    Several controversies currently dominate the fields of arthropod metabolic rate, gas exchange and water balance, including the extent to which modulation of gas exchange reduces water loss, the origins of discontinuous gas exchange, the relationship between metabolic rate and life-history strategies, and the causes of Palaeozoic gigantism. In all of these areas, repeated calls have been made for the investigation of groups that might most inform the debates, especially of taxa in key phylogenetic positions. Here we respond to this call by investigating metabolic rate, respiratory water loss and critical oxygen partial pressure (Pc) in the onychophoran Peripatopsis capensis, a member of a group basal to the arthropods, and by synthesizing the available data on the Onychophora. The rate of carbon dioxide release (VCO2) at 20 degrees C in P. capensis is 0.043 ml CO2 h(-1), in keeping with other onychophoran species; suggesting that low metabolic rates in some arthropod groups are derived. Continuous gas exchange suggests that more complex gas exchange patterns are also derived. Total water loss in P. capensis is 57 mg H2O h(-1) at 20 degrees C, similar to modern estimates for another onychophoran species. High relative respiratory water loss rates ( approximately 34%; estimated using a regression technique) suggest that the basal condition in arthropods may be a high respiratory water loss rate. Relatively high Pc values (5-10% O2) suggest that substantial safety margins in insects are also a derived condition. Curling behaviour in P. capensis appears to be a strategy to lower energetic costs when resting, and the concomitant depression of water loss is a proximate consequence of this behaviour. PMID:18805813

  12. Reproductive physiology

    USGS Publications Warehouse

    Gee, G.F.; Russman, S.E.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  13. Validation of national land-cover characteristics data for regional water-quality assessment

    USGS Publications Warehouse

    Zelt, R.B.; Brown, J.F.; Kelley, M.S.

    1995-01-01

    Land-cover information is used routinely to support the interpretation of water-quality data. The Prototype 1990 Conterminous US Land Cover Characteristics Data Set, developed primarily from Advanced Very High Resolution Radiometer (AVHRR) data, was made available to the US Geological Survey's National Water-Quality Assessment (NAWQA) Program. The study described in this paper explored the utility of the 1990 national data set for developing quantitative estimates of the areal extent of principal land-cover types within large areal units. Land-cover data were collected in 1993 at 210 sites in the Central Nebraska Basins, one of the NAWQA study units. Median percentage-corn estimates for each sampling stratum wre used to produce areally weighted estimates of the percentage-corn cover for hydrologic units. Comparison of those areal estimates with an independent source of 1992 land-cover data showed good agreement. -Authors

  14. Investigations on thermal-transfer characteristics of water based on stimulated Brillouin scattering

    NASA Astrophysics Data System (ADS)

    Shi, Jiulin; Wang, Hongpeng; Qian, Jiacheng; He, Xingdao

    2016-03-01

    In this paper, we present a successful measurement of the thermal-transfer process of water in terms of stimulated Brillouin scattering (SBS) with a pulsed Nd:YAG laser as the light source. The temperature profiles between two different temperature layers can be determined through measuring the linewidth of SBS spectra. The measured results of thermal-transfer process of water are agree well with the theoretical simulation results based on the heat conduction equation. We have demonstrated that, the geometry width and temperature gradient of gradient layer depend on the temperature difference between T1 and T0 and different thermal-transfer times. This method presents an important step towards the practical application of a Brillouin lidar system, it could provide a potential technology for investigating the distribution characteristics of the thermocline in ocean.

  15. No tillage effect on water retention characteristics of soil aggregates in rainfed semiarid conditions.

    NASA Astrophysics Data System (ADS)

    Blanco-Moure, Nuria; López, M. Victoria; Moret, David

    2010-05-01

    The evaluation of changes in soil moisture retention characteristics associated to alterations in soil structure is of great interest in tillage studies. Most of these studies have evaluated soil properties in samples of total soil but not in individual aggregates. However, soil behavior at a macroscale level depends on the aggregate properties. A better knowledge of aggregate characteristics, as the water retention properties, will help to explain, for example, the response of soil to tillage, compaction and crop growth, and hence, to plan adequate soil management practices. In this study we determine the water retention curve of soil aggregates of different sizes from a soil under two tillage systems (conventional and no tillage). The study was carried out in a silty clay loam soil of semiarid Aragon (NE Spain). Two tillage systems were compared: no tillage (NT) and conventional tillage with mouldboard plough (CT). Water retention curves (WRC) were determined for soil surface aggregates (0-5 cm) of three different sizes (8-4, 4-2 and 2-1 mm in diameter) by using the TDR-pressure cell (Moret et al. 2008. Soil Till. Res, 100, 114-119). The TDR-pressure cell is a non-destructive method which permits determining WRC with the only one and same soil sample. Thus, the pressure cell was filled with aggregates up to 4 cm height, weighted and wetted to saturation from the bottom. Pressure steps were sequentially applied at -0.5, -1.5, -3, -5, -10, -33, -100, -300 kPa, and water content of each aggregate sample was measured gravimetrically and by TDR 24 h after starting each pressure head step. The volume of the sample within the cell was also determined at this moment in order to obtain the bulk density and thus calculate the volumetric water content. A good relationship was obtained between the volumetric water content calculated from the gravimetric water content and the corresponding values measured by TDR (r2=0.907; p≤0.05). Within the same tillage treatment, no significant differences in WRC were found among soil aggregate sizes. Soil aggregates under CT retained more water at lower pressure heads in all aggregate sizes; in contrast the retention was more effective in those from NT at high pressure level. The extensive structural degradation of the CT aggregates observed during wetting with the consequent decrease in the soil volume within the transparent cell, can help to explain the different behaviour of both soils. The CT aggregates were probably disintegrated by slaking, causing a reduction in water drainage and, therefore, an increase in soil water content at low pressure heads. This idea was also confirmed with the application of the double exponential function proposed by Dexter et al. (2008. Geoderma 173, 243-253). The WRC curves measured by TDR were successfully fitted to the theoretical model proposed by Dexter (r2=0.986; p≤0.05). Thus, the model estimated that the large porosity between aggregates retain slightly more water under CT (0.36-0.39 m3 m-3) than under NT (0.31-0.35 m3 m-3). On the contrary, pores inside the aggregates tend to storage more water in NT (0.16-0.20 m3 m-3vs. 0.13-0.17 m3 m-3 in CT). These results show the suitability of NT to reduce the risk of soil crusting and compaction in agricultural lands of Aragón.

  16. Performance characteristics of single effect lithium bromide/ water absorption chiller for small data centers

    NASA Astrophysics Data System (ADS)

    Mysore, Abhishek Arun Babu

    A medium data center consists of servers performing operations such as file sharing, collaboration and email. There are a large number of small and medium data centers across the world which consume more energy and are less efficient when compared to large data center facilities of companies such as GOOGLE, APPLE and FACEBOOK. Such companies are making their data center facilities more environmental friendly by employing renewable energy solutions such as wind and solar to power the data center or in data center cooling. This not only reduces the carbon footprint significantly but also decreases the costs incurred over a period of time. Cooling of data center play a vital role in proper functioning of the servers. It is found that cooling consumes about 50% of the total power consumed by the data center. Traditional method of cooling includes the use of mechanical compression chillers which consume lot of power and is not desirable. In order to eliminate the use of mechanical compressor chillers renewable energy resources such as solar and wind should be employed. One such technology is solar thermal cooling by means of absorption chiller which is powered by solar energy. The absorption chiller unit can be coupled with either flat plate or evacuated tube collectors in order to achieve the required inlet temperature for the generator of the absorption chiller unit. In this study a modular data center is considered having a cooling load requirement of 23kw. The performance characteristics of a single stage Lithium Bromide/ water refrigeration is presented in this study considering the cooling load of 23kw. Performance characteristics of each of the 4 heat exchangers within the unit is discussed which helps in customizing the unit according to the users' specific needs. This analysis helps in studying the importance of different properties such as the effect of inlet temperatures of hot water for generator, inlet temperatures of cooling water for absorber and condenser and outlet chilled water temperatures of the evaporator.

  17. Integrated Transcriptomic and Proteomic Analysis of the Physiological Response of Escherichia coli O157:H7 Sakai to Steady-state Conditions of Cold and Water Activity Stress*

    PubMed Central

    Kocharunchitt, Chawalit; King, Thea; Gobius, Kari; Bowman, John P.; Ross, Tom

    2012-01-01

    An integrated transcriptomic and proteomic analysis was undertaken to determine the physiological response of Escherichia coli O157:H7 Sakai to steady-state conditions relevant to low temperature and water activity conditions experienced during meat carcass chilling in cold air. The response of E. coli during exponential growth at 25 °C aw 0.985, 14 °C aw 0.985, 25 °C aw 0.967, and 14 °C aw 0.967 was compared with that of a reference culture (35 °C aw 0.993). Gene and protein expression profiles of E. coli were more strongly affected by low water activity (aw 0.967) than by low temperature (14 °C). Predefined group enrichment analysis revealed that a universal response of E. coli to all test conditions included activation of the master stress response regulator RpoS and the Rcs phosphorelay system involved in the biosynthesis of the exopolysaccharide colanic acid, as well as down-regulation of elements involved in chemotaxis and motility. However, colanic acid-deficient mutants were shown to achieve comparable growth rates to their wild-type parents under all conditions, indicating that colanic acid is not required for growth. In contrast to the transcriptomic data, the proteomic data revealed that several processes involved in protein synthesis were down-regulated in overall expression at 14 °C aw 0.985, 25 °C aw 0.967, and 14 °C aw 0.967. This result suggests that during growth under these conditions, E. coli, although able to transcribe the required mRNA, may lack the cellular resources required for translation. Elucidating the global adaptive response of E. coli O157:H7 during exposure to chilling and water activity stress has provided a baseline of knowledge of the physiology of this pathogen. PMID:22008207

  18. Analysis of rabbit intervertebral disc physiology based on water metabolism. II. Changes in normal intervertebral discs under axial vibratory load

    SciTech Connect

    Hirano, N.; Tsuji, H.; Ohshima, H.; Kitano, S.; Itoh, T.; Sano, A.

    1988-11-01

    Metabolic changes induced by axial vibratory load to the spine were investigated based on water metabolism in normal intervertebral discs of rabbits with or without pentobarbital anesthesia. Tritiated water concentration in the intervertebral discs of unanesthetized rabbits was reduced remarkably by axial vibration for 30 minutes using the vibration machine developed for this study. Repeated vibratory load for 18 and 42 hours duration showed the recovery of /sup 3/H/sub 2/O concentration of the intervertebral disc without anesthesia. Computer simulation suggested a reduction of blood flow surrounding the intervertebral disc following the vibration stress. However, no reduction of the /sup 3/H/sub 2/O concentration in the intervertebral disc was noted under anesthesia. Emotional stress cannot be excluded as a factor in water metabolism in the intervertebral disc.

  19. Sensitivity of limber pine (Pinus flexilis) seedling physiology to elevation, warming, and water availability across a timberline ecotone

    NASA Astrophysics Data System (ADS)

    Moyes, A. B.; Castanha, C.; Ferrenberg, S.; Germino, M. J.; Kueppers, L. M.

    2010-12-01

    Treelines occur where environmental gradients such as temperature become limiting to tree establishment, and are thus likely to respond to changes in climate. We collected gas exchange, water potential, and fluorescence measurements from limber pine (Pinus flexilis) seedlings planted into experimental plots at three elevations at Niwot Ridge, Colorado, ranging from within forest to alpine. At each site seeds from local high- and low-elevation populations were sewn into replicated and controlled watering and infrared heating treatment plots. Heating led to earlier snowmelt, germination, and soil moisture availability in spring; higher soil surface temperatures throughout the growing season; and drier soils in late summer. Assimilation rates in all plots were most strongly associated with soil moisture availability following germination, and decreased as soils dried over the growing season. Intrinsic water use efficiency was consistent for the two source populations, but there was evidence that individuals germinating from high-elevation seeds respired more per unit carbon assimilated under our experimental conditions. Chlorophyll fluorescence showed no evidence of photoinhibition in any elevation or treatment category. Earlier soil moisture depletion in heated plots was associated with lower midday stem water potentials and reduced stomatal conductance in August. Our watering treatments did not substantially reduce apparent midsummer water stress. Seedlings in ambient temperature plots had higher assimilation rates in August than those in heated plots, but also greater carbon loss via photorespiration. Moisture limitation in heated plots in summer interacted with variability in afternoon sun exposure within plots, and qualitative observations suggested that many seedlings were killed by desiccation and heat girdling at all elevations. While early snowmelt and moisture availability in heated plots provided a longer growing season, earlier reduction of soil moisture availability in summer offset this advantage for limber pine seedling carbon gain.

  20. Development characteristics of polymethyl methacrylate in alcohol/water mixtures: a lithography and Raman spectroscopy study

    NASA Astrophysics Data System (ADS)

    Ocola, Leonidas E.; Costales, Maya; Gosztola, David J.

    2016-01-01

    Poly methyl methacrylate (PMMA) is the most widely used resist in electron beam lithography. This paper reports on a lithography and Raman spectroscopy study of development characteristics of PMMA in methanol, ethanol and isopropanol mixtures with water as developers. We have found that ethanol/water mixtures at a 4:1 volume ratio are an excellent, high resolution, non-toxic developer for exposed PMMA. We have also found that the proper methodology to use so that contrast data can be compared to techniques used in polymer science is not to rinse the developed resist but to immediately dry with nitrogen. Our results show how powerful simple lithographic techniques can be used to study ternary polymer solvent solutions when compared to other techniques used in the literature. Raman data show that both tightly bonded -OH groups and non-hydrogen bonded -OH groups play a role in the development of PMMA. Tightly hydrogen bonded -OH groups show pure Lorentzian Raman absorption only in the concentration ranges where ethanol/water and IPA/water mixtures are effective developers of PMMA, pointing to possible ordering or reduced amorphization due to the liquid state. The impact of understanding these interactions may open doors to a new developers of other electron beam resists that can reduce the toxicity of the waste stream.

  1. Adsorption characteristics of selected hydrophilic and hydrophobic micropollutants in water using activated carbon.

    PubMed

    Nam, Seung-Woo; Choi, Dae-Jin; Kim, Seung-Kyu; Her, Namguk; Zoh, Kyung-Duk

    2014-04-15

    In this study, we investigated adsorption characteristics of nine selected micropollutants (six pharmaceuticals, two pesticides, and one endocrine disruptor) in water using an activated carbon. The effects of carbon dosage, contact time, pH, DOM (dissolved organic matter), and temperature on the adsorption removal of micropollutants were examined. Increasing carbon dosage and contact time enhanced the removal of micropollutants. Sorption coefficients of hydrophilic compounds (caffeine, acetaminophen, sulfamethoxazole, and sulfamethazine) fit a linear isotherm and hydrophobic compounds (naproxen, diclofenac, 2, 4-D, triclocarban, and atrazine) fit a Freundlich isotherm. The removal of hydrophobic pollutants and caffeine were independent of pH changes, but acetaminophen, sulfamethazine, and sulfamethoxazole were adsorbed by mainly electrostatic interaction with activated carbon and so were affected by pH. The decrease in adsorption removal in surface water samples was observed and this decrease was more significant for hydrophobic than hydrophilic compounds. The decline in the adsorption capacity in surface water samples is caused by the competitive inhibition of DOM with micropollutants onto activated carbon. Low temperature (5°C) also decreased the adsorption removal of micropollutants, and affected hydrophobic compounds more than hydrophilic compounds. The results obtained in this study can be applied to optimize the adsorption capacities of micropollutants using activated carbon in water treatment process. PMID:24572271

  2. Development characteristics of polymethyl methacrylate in alcohol/water mixtures: a lithography and Raman spectroscopy study.

    PubMed

    Ocola, Leonidas E; Costales, Maya; Gosztola, David J

    2016-01-22

    Poly methyl methacrylate (PMMA) is the most widely used resist in electron beam lithography. This paper reports on a lithography and Raman spectroscopy study of development characteristics of PMMA in methanol, ethanol and isopropanol mixtures with water as developers. We have found that ethanol/water mixtures at a 4:1 volume ratio are an excellent, high resolution, non-toxic developer for exposed PMMA. We have also found that the proper methodology to use so that contrast data can be compared to techniques used in polymer science is not to rinse the developed resist but to immediately dry with nitrogen. Our results show how powerful simple lithographic techniques can be used to study ternary polymer solvent solutions when compared to other techniques used in the literature. Raman data show that both tightly bonded -OH groups and non-hydrogen bonded -OH groups play a role in the development of PMMA. Tightly hydrogen bonded -OH groups show pure Lorentzian Raman absorption only in the concentration ranges where ethanol/water and IPA/water mixtures are effective developers of PMMA, pointing to possible ordering or reduced amorphization due to the liquid state. The impact of understanding these interactions may open doors to a new developers of other electron beam resists that can reduce the toxicity of the waste stream. PMID:26656030

  3. Development of study on the dynamic characteristics of deep water mooring system

    NASA Astrophysics Data System (ADS)

    Tang, You-Gang; Zhang, Su-Xia; Zhang, Ruo-Yu; Liu, Hai-Xiao

    2007-09-01

    To meet the needs of those exploiting deepwater resources, TLP and SPAR platforms are used in some areas and are considered excellent platforms in deep water. However, many problems remain to be resolved. The design of mooring systems is a key issue for deep water platforms. Environmental loads in deep water effect the physical characteristics of mooring line materials. The configuration and analysis of mooring systems involve nonlinearity due to this fluid-solid coupling, nonlinear hydrodynamic forces, and their effects on stability of motion. In this paper, some pivotal theories and technical questions are presented, including modeling of mooring lines, the theory and method of coupled dynamics analysis on the mooring system, and the development of methodologies for the study of nonlinear dynamics of mooring systems. Further study on mooring systems in deep water are recommended based on current knowledge, particularly dynamic parameters of different materials and cable configuration, interactions between seabed and cable, mechanisms of mooring system response induced by taut/slack mooring cables, discontinuous stiffness due to system materials, mooring construction, and motion instability, etc.

  4. Development characteristics of polymethyl methacrylate in alcohol/water mixtures. A lithography and Raman spectroscopy study

    SciTech Connect

    Ocola, Leonidas E.; Costales, Maya; Gosztola, David J.

    2015-12-10

    Poly methyl methacrylate (PMMA) is the most widely used resist in electron beam lithography. This paper reports on a lithography and Raman spectroscopy study of development characteristics of PMMA in methanol, ethanol and isopropanol mixtures with water as developers. We have found that ethanol/water mixtures at a 4:1 volume ratio are an excellent, high resolution, non-toxic, developer for exposed PMMA. We also have found that the proper methodology to use so that contrast data can be compared to techniques used in polymer science is not to rinse the developed resist but to immediately dry with nitrogen. Our results show how powerful simple lithographic techniques can be used to study ternary polymer solvent solutions when compared to other techniques used in the literature. Raman data shows that there both tightly bonded –OH groups and non-hydrogen bonded –OH groups play a role in the development of PMMA. Tightly hydrogen bonded –OH groups show pure Lorentzian Raman absorption only in the concentration ranges where ethanol/water and IPA/water mixtures are effective developers of PMMA. The impact of the understanding these interactions may open doors to a new developers of other electron beam resists that can reduce the toxicity of the waste stream.

  5. Numerical Simulation on Subcooled Boiling Heat Transfer Characteristics of Water-Cooled W/Cu Divertors

    NASA Astrophysics Data System (ADS)

    Han, Le; Chang, Haiping; Zhang, Jingyang; Xu, Tiejun

    2015-04-01

    In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition, the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters is crucial. In this paper, subcooled boiling heat transfer in a water-cooled W/Cu divertor was numerically investigated based on computational fluid dynamic (CFD). The boiling heat transfer was simulated based on the Euler homogeneous phase model, and local differences of liquid physical properties were considered under one-sided high heating conditions. The calculated wall temperature was in good agreement with experimental results, with the maximum error of 5% only. On this basis, the void fraction distribution, flow field and heat transfer coefficient (HTC) distribution were obtained. The effects of heat flux, inlet velocity and inlet temperature on temperature distribution and pressure drop of a water-cooled W/Cu divertor were also investigated. These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2010GB104005), Funding of Jiangsu Innovation Program for Graduate Education (CXLX12_0170), the Fundamental Research Funds for the Central Universities of China

  6. [Change characteristics of climate and water resources in west Liaohe River Plain].

    PubMed

    Yang, Heng-shan; Liu, Jiang; Liang, Huai-yu

    2009-01-01

    Based on the 1951-2007 observation data of precipitation and temperature from Tongliao, Kailu, and Zhalute meteorological stations as well as the related hydrologic data from Tongliao hydrological survey bureau and water affairs bureau, the change characteristics of the climate and water resources in west Liaohe River Plain were studied. The results showed that in 1951-2007, the precipitation in its periodical changes in study area had a decreasing trend. The tendency rate of precipitation was -13.2 mm x (10 a)(-1), and the instability of precipitation was increased. The runoff of four inbound rivers including Xilamulun all decreased, with the mean annual runoff in 2001-2007 being only 22.8% of that in 1990-1994. From 1951 to 2007, the runoff of west Liaohe River decreased, and the days of its zero flow increased. Since 2001, the River had been zero flow. The groundwater overdraft area and the funnel area in Keerqin Region in 2006 increased by 8.5 times and 15.5 times, respectively, compared with those in 1978; and the average groundwater level in Keerqin Region, Kailu County, and Naiman Banner in 2006 increased by 3.76 m, 2.77 m, and 1.93 m, respectively, compared with that in 1980. Since the 1970s, the number of electromechanical well in study area was increasing, irrigation amount had a fluctuated rise, and the proportion of agricultural water consumption had different extent decrease. Therefore, to exploit and use the water resources in atmosphere, to popularize water-saving irrigation technologies, and to make a reasonable arrangement of industrial structure were the effective measures in realizing the sustainable utilization of water resources in west Liaohe River Plain. PMID:19449570

  7. Physicochemical Characteristics of Larval Habitat Waters of Mosquitoes (Diptera: Culicidae) in Qom Province, Central Iran

    PubMed Central

    Abai, Mohammad Reza; Saghafipour, Abedin; Ladonni, Hossein; Jesri, Nahid; Omidi, Saeed; Azari-Hamidian, Shahyad

    2016-01-01

    Background: Mosquitoes lay eggs in a wide range of habitats with different physicochemical parameters. Ecological data, including physicochemical factors of oviposition sites, play an important role in integrated vector management. Those data help the managers to make the best decision in controlling the aquatic stages of vectors especially using source reduction. Methods: To study some physicochemical characteristics of larval habitat waters, an investigation was carried out in Qom Province, central Iran, during spring and summer 2008 and 2009. Water samples were collected during larval collection from ten localities. The chemical parameters of water samples were analyzed based on mg/l using standard methods. Water temperature (°C), turbidity (NTU), total dissolved solids (ppm), electrical conductivity (μS/cm), and acidity (pH) were measured using digital testers. Thermotolerant coliforms of water samples were analyzed based on MPN/100ml. Data were assessed by Kruskal-Wallis test and Spearman Correlation analysis. Results: In total, 371 mosquito larvae were collected including 14 species representing four genera. Some physicochemical parameters of water in Emamzadeh Esmail, Qomrood, Qom City, and Rahjerd showed significant differences among localities (P< 0.05). The physicochemical and microbial parameters did not show any significant differences among different species (P> 0.05). There was no significant correlation between the abundance of larvae and the different physicochemical and microbial parameters (P> 0.05). Conclusion: The means of EC, TDS, and phosphate of localities and species were remarkably higher than those of the previous studies. Other parameters seem to be in the range of other investigations.

  8. Electric discharge in the water: physics of formation and radiative characteristics.

    NASA Astrophysics Data System (ADS)

    Anpilov, Andrei; Barkhudarov, Eduard; Kozlov, Yurii; Kossyi, Igor; Silakov, Valerii; Temchin, Savelii

    2004-09-01

    ELECTRIC DISCHARGE IN THE WATER: PHYSICS OF FORMATION AND RADIATIVE CHARACTERISTICS 2.10. Lighting plasmas. 2.26. Other plasma topics. A.M.Anpilov, E.M.Barkhudarov, Yu.N.Kozlov, I.A.Kossyi, V.P.Silakov and S.M.Temchin Two types of electric discharge in the water have been investigated: discharge between two electrodes and multielectrode gliding surface discharge. Results are presented from experimental studies of the prebreakdown phase of an electric discharge between the point (anode) and plane (cathode) electrodes immersed in the water with different initial conductivity. When a high-voltage pulse is applied, the induced conductivity is detected in the discharge gap. Its value is one order of magnitude higher than the initial one. It is shown that the induced conductivity increases almost linearly with initial conductivity. The induced conductivity correlates with the UV emission from the cathode surface. A qualitative analysis of the experimental results is performed. Investigations of a spectrum of radiation of discharge in water have been carried out. On the base of broadening and shifting of atomic hydrogen and oxygen lines electron density in a prebreakdown as well as breakdown stages has been determined. Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190 £l£430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the gliding surface discharge in water for its disinfection is analysed.

  9. Physiological and biochemical characterisation of watered and drought-stressed barley mutants in the HvDWARF gene encoding C6-oxidase involved in brassinosteroid biosynthesis.

    PubMed

    Janeczko, Anna; Gruszka, Damian; Pociecha, Ewa; Dziurka, Michał; Filek, Maria; Jurczyk, Barbara; Kalaji, Hazem M; Kocurek, Maciej; Waligórski, Piotr

    2016-02-01

    Brassinosteroids (BR) are plant steroid hormones that were discovered more than thirty years ago, but their physiological function has yet to be fully explained. The aim of the study was to answer the question of whether/how disturbances in the production of BR in barley affects the plant's metabolism and development under conditions of optimal watering and drought. Mutants with an impaired production of BR are one of the best tools in research aimed at understanding the mechanisms of action of these hormones. The study used barley cultivars with a normal BR synthesis (wild type) and semi-dwarf allelic mutants with an impaired activity of C6-oxidase (mutation in HvDWARF), which resulted in a decreased BR synthesis. Half of the plants were subjected to drought stress in the seedling stage and the other half were watered optimally. Plants with impaired BR production were characterised by a lower height and developmental retardation. Under both optimal watering and drought, BR synthesis disorders caused the reduced production of ABA and cytokinins, but not auxins. The BR mutants also produced less osmoprotectant (proline). The optimally watered and drought-stressed mutants accumulated less sucrose, which was accompanied by changes in the production of other soluble sugars. The increased content of fructooligosaccharide (kestose) in optimally watered mutants would suggest that BR is a negative regulator of kestose production. The decreased level of nystose in the drought-stressed mutants also suggests BR involvement in the regulation of the production of this fructooligosaccharide. The accumulation of the transcripts of genes associated with stress response (hsp90) was lower in the watered and drought-stressed BR-deficient mutants. In turn, the lower efficiency of photosystem II and the net photosynthetic rate in mutants was revealed only under drought conditions. The presented research allows for the physiological and biochemical traits of two BR-barley mutants to be characterised, which helps BR function to be understood. The knowledge can also be a good starting point for some breeding companies that are interested in introducing new semi-dwarf barley cultivars. PMID:26752435

  10. Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

    PubMed Central

    Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

    2012-01-01

    The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via KruskalWallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs. PMID:22566743

  11. Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Among popular commercial varieties, TAM 111 and TAM 112 showed a superior adaptation to water-deficit c...

  12. Water fluoridation: a critical review of the physiological effects of ingested fluoride as a public health intervention.

    PubMed

    Peckham, Stephen; Awofeso, Niyi

    2014-01-01

    Fluorine is the world's 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed. PMID:24719570

  13. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention

    PubMed Central

    2014-01-01

    Fluorine is the world's 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed. PMID:24719570

  14. Composition and physiological function of the wax layers coating Arabidopsis leaves: β-amyrin negatively affects the intracuticular water barrier.

    PubMed

    Buschhaus, Christopher; Jetter, Reinhard

    2012-10-01

    Plants prevent dehydration by coating their aerial, primary organs with waxes. Wax compositions frequently differ between species, organs, and developmental stages, probably to balance limiting nonstomatal water loss with various other ecophysiological roles of surface waxes. To establish structure-function relationships, we quantified the composition and transpiration barrier properties of the gl1 mutant leaf waxes of Arabidopsis (Arabidopsis thaliana) to the necessary spatial resolution. The waxes coating the upper and lower leaf surfaces had distinct compositions. Moreover, within the adaxial wax, the epicuticular layer contained more wax and a higher relative quantity of alkanes, whereas the intracuticular wax had a higher percentage of alcohols. The wax formed a barrier against nonstomatal water loss, where the outer layer contributed twice as much resistance as the inner layer. Based on this detailed description of Arabidopsis leaf waxes, structure-function relationships can now be established by manipulating one cuticle component and assessing the effect on cuticle functions. Next, we ectopically expressed the triterpenoid synthase gene AtLUP4 (for lupeol synthase4 or β-amyrin synthase) to compare water loss with and without added cuticular triterpenoids in Arabidopsis leaf waxes. β-Amyrin accumulated solely in the intracuticular wax, constituting up to 4% of this wax layer, without other concomitant changes of wax composition. This triterpenoid accumulation caused a significant reduction in the water barrier effectiveness of the intracuticular wax. PMID:22885935

  15. The Importance of the Ionic Product for Water to Understand the Physiology of the Acid-Base Balance in Humans

    PubMed Central

    Adeva-Andany, María M.; Carneiro-Freire, Natalia; Donapetry-García, Cristóbal; Rañal-Muíño, Eva; López-Pereiro, Yosua

    2014-01-01

    Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on the plasma ionic composition. Variations in the concentration of plasma ions that alter the relative proportion of anions and cations predictably lead to a change in the plasma concentration of hydrogen ions by driving adaptive adjustments in water ionization that allow plasma electroneutrality while maintaining constant the ionic product for water. The accumulation of plasma anions out of proportion of cations induces an electrical imbalance compensated by a fall of hydroxide ions that brings about a rise in hydrogen ions (acidosis). By contrast, the deficiency of chloride relative to sodium generates plasma alkalosis by increasing hydroxide ions. The adjustment of plasma bicarbonate concentration to these changes is an important compensatory mechanism that protects plasma pH from severe deviations. PMID:24877130

  16. Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses

    NASA Astrophysics Data System (ADS)

    Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

    2013-12-01

    In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these unpredictable rainfall conditions, plant hydraulic traits (xylem and stomatal response to water availability) and morphological features (leaf and sapwood areas) must be coordinated - thus providing an ecohydrological interpretation of observed coordination (or homeostasis) among hydraulic traits. Moreover, the combinations of hydraulic traits and responses to drought that are optimal are found to depend on both total rainfall and its distribution during the growing season. Both drier conditions and more intense rainfall events interspaced by longer dry periods favor plants with high resistance to cavitation and delayed stomatal closure as soils dry. In contrast, plants in mesic conditions benefit from cavitation prevention through earlier stomatal closure. The proposed ecohydrological optimality criteria can be used as analytical tools to interpret variability in plant water use and predict trends in plant productivity and species composition under future climates.

  17. [Characteristics of water soluble inorganic ions in fine particles emitted from coal-fired power plants].

    PubMed

    Duan, Lei; Ma, Zi-Zhen; Li, Zhen; Jiang, Jing-Kun; Ye, Zhi-Xiang

    2015-03-01

    Currently, China suffers from serious pollution of fine particulate matter (PM2.5). Coal-fired power plant is one of the most important sources of PM2.5 in the atmosphere. To achieve the national goals of total emission reductions of sulfur dioxide (SO2) and nitrogen oxides (NO(x)) during the 11th and 12th Five-Year Plan, most of coal-fired power plants in China have installed or will install flue gas desulfurization (FGD) and flue gas denitrification (DNO(x)) systems. As a result, the secondary PM2.5, generated from gaseous pollutants in the atmosphere, would be decreased. However, the physical and chemical characteristics of PM2.5 in flue gas would be affected, and the emission of primary PM2.5 might be increased. This paper summarized the size distributions of PM2.5 and its water soluble ions emitted from coal-fired power plants, and highlighted the effects of FGD and DNO(x) on PM2.5 emission, especially on water soluble ions (such as SO4(2-), Ca2+ and NH4+) in PM2.5. Under the current condition of serious PM2.5 pollution and wide application of FGD and DNO(x), quantitative study on the effects of FGD and DNO(x) installation on emission characteristics of PM2.5 from coal-fired power plants is of great necessity. PMID:25929084

  18. Physiological, biochemical and morphological indicators of osmoregulatory stress in 'California' Mozambique tilapia (Oreochromis mossambicus x O. urolepis hornorum) exposed to hypersaline water.

    PubMed

    Sardella, Brian A; Matey, Victoria; Cooper, Jill; Gonzalez, Richard J; Brauner, Colin J

    2004-03-01

    The salinity tolerance of the 'California' Mozambique tilapia (Oreochromis mossambicus x O. urolepis hornorum), a current inhabitant of the hypersaline Salton Sea in California, USA, was investigated to identify osmoregulatory stress indicators for possible use in developing a model of salinity tolerance. Seawater-acclimated (35 g l(-1)) tilapia hybrids were exposed to salinities from 35-95 g l(-1), using gradual and direct transfer protocols, and physiological (plasma osmolality, [Na+], [Cl-], oxygen consumption, drinking rate, hematocrit, mean cell hemoglobin concentration, and muscle water content), biochemical (Na+, K(+)-ATPase) and morphological (number of mature, accessory, immature and apoptotic chloride cells) indicators of osmoregulatory stress were measured. Tilapia tolerated salinities ranging from 35 g l(-1) to 65 g l(-1) with little or no change in osmoregulatory status; however, in fish exposed to 75-95 g l(-1) salinity, plasma osmolality, [Na+], [Cl-], Na+, K(+)-ATPase, and the number of apoptotic chloride cells, all showed increases. The increase in apoptotic chloride cells at salinities greater than 55 g l(-1), prior to changes in physiological and biochemical parameters, indicates that it may be the most sensitive indicator of osmoregulatory stress. Oxygen consumption decreased with salinity, indicating a reduction in activity level at high salinity. Finally, 'California' Mozambique tilapia have a salinity tolerance similar to that of pure Mozambique tilapia; however, cellular necrosis at 95 g l(-1) indicates they may be unable to withstand extreme salinities for extended periods of time. PMID:15010491

  19. Modeling gravity effects on water retention and gas transport characteristics in plant growth substrates

    NASA Astrophysics Data System (ADS)

    Chamindu Deepagoda, T. K. K.; Jones, Scott B.; Tuller, Markus; de Jonge, Lis Wollesen; Kawamoto, Ken; Komatsu, Toshiko; Moldrup, Per

    2014-08-01

    Growing plants to facilitate life in outer space, for example on the International Space Station (ISS) or at planned deep-space human outposts on the Moon or Mars, has received much attention with regard to NASA’s advanced life support system research. With the objective of in situ resource utilization to conserve energy and to limit transport costs, native materials mined on Moon or Mars are of primary interest for plant growth media in a future outpost, while terrestrial porous substrates with optimal growth media characteristics will be useful for onboard plant growth during space missions. Due to limited experimental opportunities and prohibitive costs, liquid and gas behavior in porous substrates under reduced gravity conditions has been less studied and hence remains poorly understood. Based on ground-based measurements, this study examined water retention, oxygen diffusivity and air permeability characteristics of six plant growth substrates for potential applications in space, including two terrestrial analogs for lunar and Martian soils and four particulate substrates widely used in reduced gravity experiments. To simulate reduced gravity water characteristics, the predictions for ground-based measurements (1 - g) were scaled to two reduced gravity conditions, Martian gravity (0.38 - g) and lunar gravity (0.16 - g), following the observations in previous reduced gravity studies. We described the observed gas diffusivity with a recently developed model combined with a new approach that estimates the gas percolation threshold based on the pore size distribution. The model successfully captured measured data for all investigated media and demonstrated the implications of the poorly-understood shift in gas percolation threshold with improved gas percolation in reduced gravity. Finally, using a substrate-structure parameter related to the gaseous phase, we adequately described the air permeability under reduced gravity conditions.

  20. Transcriptional and physiological response of fathead minnows (Pimephales promelas) exposed to urban waters entering into wildlife protected areas.

    PubMed

    Rodriguez-Jorquera, Ignacio A; Kroll, Kevin J; Toor, Gurpal S; Denslow, Nancy D

    2015-04-01

    The mission of protected areas is to conserve biodiversity and improve human welfare. To assess the effect of urban waters entering into protected areas, we performed 48-h whole-effluent exposures with fathead minnows, analyzing changes in steady state levels of mRNAs in the livers of exposed fish. Raw wastewater, treated city wastewater, and treated wastewater from a university were collected for exposures. All exposed fish showed altered mRNA levels of DNA damage-repair genes. Fish exposed to raw and treated wastewaters showed down-regulation of transcripts for key intermediates of cholesterol biosynthesis and elevated plasma cholesterol. The type of wastewater treatment influenced the response of gene transcription. Because of the relevance of some of the altered cellular pathways, we suggest that these effluents may cause deleterious effects on fish inside protected areas that receive these waters. Inclusion of research and mitigation efforts for this type of threat in protected areas management is advised. PMID:25656232

  1. Physiological and biochemical changes relating to postharvest splitting of sweet cherries affected by calcium application in hydrocooling water.

    PubMed

    Wang, Yan; Long, Lynn E

    2015-08-15

    Hydrocooling sweet cherries shortly after harvest (4h) and then transporting fruit in cold flume water during packing are used to maximize postharvest quality, but can cause fruit splitting. This study demonstrated that cherry fruit (two splitting-susceptible cultivars) absorbed Ca in a quadratic polynomial manner with increasing CaCl2 concentration from 0.2% to 2.0% in cold water (0°C) for 5 min, but did not take up Cl. The enhanced tissue Ca content reduced splitting potential by decreasing fruit soluble pectin release and increasing the splitting threshold. In contrast, depleting Ca from fruit tissue by EDTA or low pH, increased soluble pectin release and splitting potential. In a simulated commercial procedure, hydrocooling cherry fruit in appropriate CaCl2 solutions (i.e., 0.2-0.5%) for 5 min and then passing the fruit in cold flume water for 15 min increased fruit firmness, retarded losses in ascorbic acid, titratable acidity, and skin color, and reduced splitting and decay following 4 weeks of cold storage. PMID:25794746

  2. Low-level exposure to methylmercury modifies muscarinic cholinergic receptor binding characteristics in rat brain and lymphocytes: physiologic implications and new opportunities in biologic monitoring.

    PubMed Central

    Coccini, T; Randine, G; Candura, S M; Nappi, R E; Prockop, L D; Manzo, L

    2000-01-01

    Methylmercury (MeHg) affects several parameters of cholinergic function. These alterations are thought to play a role in MeHg neurotoxicity. In vitro experiments have indicated that MeHg acts as a strong competitive inhibitor of radioligand binding to muscarinic cholinergic receptors (mAChRs) in rat brain. Furthermore, rat brain mAChRs share several pharmacologic characteristics of similar receptors present on lymphocytes. Using the muscarinic antagonist [(3)H]quinuclidinyl benzilate (QNB) to label receptors, we investigated the in vivo interactions of MeHg with rat brain mAChRs. We also investigated whether MeHg-induced central mAChR changes are reflected by similar alterations in splenic lymphocytes. Exposure to low doses of MeHg--0.5 or 2 mg/kg/day in drinking water--for 16 days significantly increased (20-44% of control) mAChRs density (B(max)) in the hippocampus and cerebellum without affecting receptor affinity (K(d)). The effect of MeHg did not occur immediately; it was not apparent until 2 weeks after the termination of treatment. No significant changes in [(3)H]QNB binding were observed in the cerebral cortex. In splenic lymphocytes, mAChR density was remarkably increased (95-198% of control) by day 14 of MeHg exposure and remained enhanced 14 days after the cessation of treatment. These results suggest up-regulation of mAChRs in selected brain regions (hippocampus and cerebellum) after prolonged low-level ingestion of MeHg in rats. These cerebral effects are delayed in onset and are preceded by a marked increase in density of mAChRs on lymphocytes. In chronic MeHg exposure, peripheral ly