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1

The anthropometrical and physiological characteristics of elite water polo players  

Microsoft Academic Search

In order to examine the physical and physiological demands of water polo, we assessed the profile of elite water polo players. Nineteen male professional water polo players (age: 25.5±5.0 years, height: 184.5±4.3 cm body mass: 90.7±6.4 kg) underwent body composition assessment by dual-energy X-ray absorptiometry. We also evaluated peak oxygen consumption V?O2peak, lactate threshold (LT), energy cost of swimming (Cs), anaerobic capacity and

Yiannis E. Tsekouras; Stavros A. Kavouras; Alessandro Campagna; Yiannis P. Kotsis; Silia S. Syntosi; Kalomira Papazoglou; Labros S. Sidossis

2005-01-01

2

[Water physiological characteristics of four perennial plant species around Cele Oasis in Xinjiang].  

PubMed

The water physiological characteristics of four perennial plant species (Populus euphratica, Tamarix ramosissima, Calligonum caput-medusae, and Alhagi sparsifolia) around Cele Oasis in Xinjiang were studied through their vegetation growth period. No signs of serious drought stress were observed in any of the test perennial species during their vegetation growth, and irrigation had little effects on the water status of the plants (P > 0.05). The seasonal variation characteristics of water physiological parameters differed with the plants. A. sparsifolia had the highest predawn water potential (PWP) and daily mean sap flow, but the lowest mean water use efficiency (WUE); C. caput-medusae had the highest mean WUE, and its PWP and sap flow were stable and had less seasonal change; T. ramosissima had the lowest PWP during its growth, and had better adaptation ability to the environment; and P. euphratica had relatively stable water physiological characteristics during its growth. The four perennial plant species had deep root systems to access underground water to satisfy their large demands for water, and thus, well adapted to the harsh environmental conditions around Cele Oasis. PMID:20135993

Zeng, Fan-Jiang; Li, Xiang-Yi; Zhaneg, Xi-Ming; Foetzki, A; Arndt, S K

2009-11-01

3

Influence of Water Hardness and Salts on Survival and Physiological Characteristics of Striped Bass during and after Transport  

Microsoft Academic Search

Physiological characteristics and survival of striped bass Morone saxatilis were evaluated during, and for 1 month after, transportation from a soft-water hatchery (hardness, 28 mg\\/ L) to a hard-water hatchery (hardness, 110 mg\\/L). Fish were transported and allowed to recover in either 1.0% sodium chloride, 0.1 % calcium chloride, or fresh water. The addition of 1.0% sodium chloride to the

Patricia M. Mazik; Bill A. Simco; Nick C. Parker

1991-01-01

4

Composition, characteristics, and in-vitro physiological effects of the water-soluble polysaccharides from Cassia seed.  

PubMed

The popular beverage ingredients Cassia obtusifolia and Cassia tora were found to have considerable amounts of water-soluble polysaccharides (WSPs) (58.5 and 55.9/100g of dried extract). The composition, characteristics, and in-vitro physiological effects of these polysaccharides and their possible health benefits were investigated. The major polysaccharide components in the WSP of C. obtusifolia were possibly pectic polysaccharides and hemicellulose, while C. tora WSP was mainly composed of arabinoglucan and pectic polysaccharides. These WSPs had inhibitory effects on the activities of ?-amylase and pancreatic lipase, while they rendered an increase in protease activity. These WSPs also had the ability to bind bile acids and reduce the amount of cholesterol available for absorption. This suggested that these WSPs had potential application as herbal ingredients in beverages. Further investigations on their in-vivo hypocholesterolaemic effects and intestinal functions using animal-feeding experiments are under way. PMID:23442645

Huang, Ya-Ling; Chow, Chau-Jen; Tsai, Yung-Hsiang

2012-04-05

5

Physiological Water Model Development.  

National Technical Information Service (NTIS)

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 r...

S. Doty

1993-01-01

6

Physiologic Responses to Treadmill and Water Running.  

ERIC Educational Resources Information Center

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)

Bishop, Phillip A.; And Others

1989-01-01

7

[Influence of shading during the processes of drought stress and re-watering on the physiological and biochemical characteristics of Haplocladium microphyllum].  

PubMed

An artificial water control experiment was conducted to study the influence of shading on the membrane permeability, osmoregulation capability, and protective enzyme activities of Haplocladium microphyllum during the processes of drought stress and re-watering. Four treatments of shading were installed, i. e., full daylight and 30%, 50% and 70% of shading. During drought stress, the relative water content of H. microphyllum presented a decreasing trend, while the relative conductivity reached the maximum when the drought stress lasted for 21 days, and the conductivity was high up to 58.0% under full daylight. The soluble sugar and free proline contents and the SOD and POD activities of the plant under drought stress were decreased after a sustained increase. During re-watering, the relative water content of H. microphyllum showed an increasing trend, the relative conductivity, soluble sugar and free proline contents, and SOD and POD activities had a slight increase first and decreased gradually then, but the SOD and POD still kept high activities. After re-watering, most of the test indices recovered to the levels before the drought stress. It was suggested that H. microphyllum had the typical characteristics of resurrection plants, possessing a strong capability against drought during the variation of soil moisture content. PMID:23717990

Chen, Wen-Jia; Zhang, Nan; Hang, Lu-Lu; Wang, Yuan; Ji, Meng-Cheng

2013-01-01

8

Biometrical characteristics and physiological responses to a local cold exposure of the extremities  

Microsoft Academic Search

The aim of this study was firstly to describe the physiological responses observed in 19 subjects during immersion of the arm up to the elbow in water at 5 °C (5 min) followed by a 10-min recovery and secondly, to correlate the observed physiological responses with biometrical characteristics of the subjects (maximal oxygen uptake, VO2max, percentage fat content of whole

Gustave Savourey; Isabelle Sendowski; Jacques Bittel

1996-01-01

9

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...

10

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...

11

Physiological characteristics of America's Cup sailors  

Microsoft Academic Search

The aim of this study was to assess the physiological profile of America's Cup grinders and mastmen, by measuring energy expenditure during sailing and assessing their aerobic and anaerobic fitness. The study focused on estimating the energy used during grinding activity, by measuring oxygen uptake ([Vdot]O2) during sail setting in real sailing conditions. In the laboratory, using an arm-cranking ergometer,

Marco Bernardi; Filippo M. Quattrini; Angelo Rodio; Giuseppe Fontana; Andrea Madaffari; Marco Brugnoli; Marco Marchetti

2007-01-01

12

Physiological and Psychological Characteristics of Successful Combat Controller Trainees.  

National Technical Information Service (NTIS)

The USAF Combat Controller (CCT) training pipeline is extremely arduous and historically has an attrition rate of 70-80%. The primary objective of this study was to identify the physiological, psychological or demographical characteristics associated with...

C. Mauzy J. N. McGregor L. Lennemann M. F. Zupan T. B. Walker

2010-01-01

13

Obestatin: its physicochemical characteristics and physiological functions.  

PubMed

Obestatin, a novel 23 amino acid amidated peptide encoded by the same gene with ghrelin, was initially reported to reduce food intake, body weight gain, gastric emptying and suppress intestinal motility through an interaction with the orphan receptor GPR39. However, recently reports have shown that above findings had been questioned by several groups. Further studies explained that obestatin was involved in inhibiting thirst and anxiety, improving memory, regulating sleep, affecting cell proliferation, and increasing the secretion of pancreatic juice enzymes. We also identified that obestatin could stimulate piglet liver and adipose cell proliferation, and inhibit the secretion of IGF-I. According to the controversy over the effects and the cognate ligand of obestatin, here we provide the latest review on the structure, distribution and physiological functions of obestatin. PMID:18325633

Tang, Sheng-Qiu; Jiang, Qing-Yan; Zhang, Yong-Liang; Zhu, Xiao-Tong; Shu, Gang; Gao, Ping; Feng, Ding-Yuan; Wang, Xiu-Qi; Dong, Xiao-Ying

2008-01-31

14

Physiological characteristics of elite soccer players.  

PubMed

Soccer is one of the most popular sports in the world. There is still much uncertainty and debate surrounding its physiological requirements because emphasis is on skills to the neglect of fitness, conservative training methods and the difficulty of studying the sport scientifically. The frequently found values for total distance covered in a game of about 10 km and an above-average, though not outstanding, maximum oxygen uptake of 60 ml/kg/min suggest a moderate overall aerobic demand. A comparison of top teams and players with less able participants indicates that the components of anaerobic fitness-speed, power, strength and the capacity of the lactic acid system may differentiate better between the 2 groups. Generally, there is a reduction in the level of activity in the second half of games compared with the first. There is some evidence that increased aerobic fitness may help counteract this. Progressively lower muscle glycogen stores are one likely cause of reduction in activity, and nutrition also appears to be a key factor in minimising performance deterioration, both in terms of overall diet and, more particularly, the ingestion of carbohydrates immediately before, during and after a game. There are evolutionary trends in the sport such as greater frequency of games, changes in the roles of players, and new strategies and tactics which are placing increasing demands on the all-round fitness of players. Many studies indicate scope for improvement in player fitness. The challenge for coaches and players is to meet these fitness requirements without sacrificing the skill work which makes the sport unique. PMID:8378671

Tumilty, D

1993-08-01

15

Aquaporin water channels in gastrointestinal physiology.  

PubMed

Fluid transport is a major function of the gastrointestinal (GI) tract with more than 9 litres of fluid being absorbed or secreted across epithelia in human salivary gland, stomach, the hepatobiliary tract, pancreas, small intestine and colon. This review evaluates the evidence that aquaporin-type water channels are involved in GI fluid transport. The aquaporins are a family of small ( approximately 30 kDa) integral membrane proteins that function as water channels. At least seven aquaporins are expressed in various tissues in the GI tract: AQP1 in intrahepatic cholangiocytes, AQP4 in gastric parietal cells, AQP3 and AQP4 in colonic surface epithelium, AQP5 in salivary gland, AQP7 in small intestine, AQP8 in liver, pancreas and colon, and AQP9 in liver. There are functional data suggesting that some GI cell types expressing aquaporins have high or regulated water permeability; however, there has been no direct evidence for a role of aquaporins in GI physiology. Recently, transgenic mice have been generated with selective deletions of various aquaporins. Preliminary evaluation of GI function suggests a role for AQP1 in dietary fat processing and AQP4 in colonic fluid absorption. Further study of aquaporin function in the GI tract should provide new insights into normal GI physiology and disease mechanisms, and may yield novel therapies to regulate fluid movement in GI diseases. PMID:10332084

Ma, T; Verkman, A S

1999-06-01

16

Anthropometric and physiological characteristics of junior elite volleyball players  

Microsoft Academic Search

Objectives: To investigate the anthropometric and physiological characteristics of junior elite volleyball players.Method: Twenty five national level volleyball players (mean (SD) age 17.5 (0.5) years) were assessed on a number of physiological and anthropometric variables. Somatotype was assessed using the Heath-Carter method, body composition (% body fat, % muscle mass) was assessed using surface anthropometry, leg strength was assessed using

M J Duncan; L Woodfield; Y al-Nakeeb

2006-01-01

17

Physiological importance of aquaporin water channels.  

PubMed

Aquaporins (AQP) are a family of at least ten homologous water transporting proteins in mammals that are expressed in many epithelial, endothelial and other tissues. Abnormalities in humans and mice lacking AQPs provide direct evidence for their physiological importance. Humans lacking AQP1 or AQP2 manifest polyuria with defective urinary concentrating ability and humans with mutations in MIP (AQP0) develop cataracts. Transgenic knockout mice lacking AQP1 or AQP3 are also remarkably polyuric, and knock-in mice expressing a mutant AQP2 have severe nephrogenic diabetes insipidus resulting in impaired neonatal survival. Other interesting phenotypes in AQP knockout mice include reduced pain sensation, reduced intraocular pressure, defective corneal fluid transport and impaired dietary fat processing (AQP1), dry skin (AQP3), protection from brain swelling and impaired hearing/vision (AQP4), and reduced fluid secretion by salivary and airway submucosal glands (AQP5). However, many phenotype studies were negative, such as normal airway/lung and skeletal muscle function despite AQP expression, indicating that tissue-specific aquaporin expression does not indicate physiological significance. The general paradigm from studies on transgenic mouse models of AQP deletion is that AQPs facilitate rapid near-isosmolar transepithelial fluid absorption / secretion, as well as rapid vectorial water movement driven by osmotic gradients. The transgenic mouse studies suggest that aquaporin inhibitors may have clinical indications as diuretics and in the treatment of cerebral edema, elevated intraocular pressure, and other conditions of abnormal fluid homeostasis. PMID:12173689

Verkman, Alan S

2002-01-01

18

Citation Characteristics of Physiology Literature, 1970-72  

ERIC Educational Resources Information Center

|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)|

Hafner, A. W.

1976-01-01

19

Water as an essential nutrient: the physiological basis of hydration  

Microsoft Academic Search

How much water we really need depends on water functions and the mechanisms of daily water balance regulation. The aim of this review is to describe the physiology of water balance and consequently to highlight the new recommendations with regard to water requirements. Water has numerous roles in the human body. It acts as a building material; as a solvent,

E Jéquier; F Constant

2010-01-01

20

Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi.  

PubMed

A total of 39 environmental isolates of pathogenic dematiaceous fungi (Fonsecaea pedrosoi: 14 isolates, Phialophora verrucosa: 6, Cladosporium carrionii: 9, Exophiala jeanselmei: 2, Ramichloridium subulatum: 6, Cladosporium tenuissimum: 1 and Phaeoisaria clematidis: 1) were evaluated for their various physiological characteristics including the ability to produce extracellular enzymes. Significant physiological characteristics included the ability of isolates of all the species except C. tenuissimum to decompose tyrosine, lyse human red blood cells, conversion of R. subulatum from filamentous to yeast form when cultured on Czapek-Dox agar and also on blood agar and the growth of C. tenuissimum on Sabouraud dextrose agar incorporating 3.6 M NaCl. Isolates of all the species except those of C. carrionii produced lipase, while only the isolates of P. verrucosa, E. jeanselmei and Ph. clematidis were positive for phospholipase. PMID:2710157

Gugnani, H C; Okeke, C N

1989-02-01

21

Physiological demands of water polo goalkeeping.  

PubMed

The purpose of this study was to investigate the physiological demands of water polo goalkeepers during competition and to examine whether the playing intensity of the goalkeeper decreases as the game time progresses. During eight official games the following measurements were performed on eight elite water polo goalkeepers: (1) video analysis of activities, (2) monitoring of blood lactate (BLa) and (3) continuous recording of heart rate (HR) responses. Mean HR of total mixed playing time, excluding breaks among quarters, was 134.3+/-20.3bpm for 36 (4x9) min of game duration. The large portion of the game (85.6%) was performed with a HR lower than 151.4+/-2.7bpm (82.1+/-1.4% of HRpeak) an intensity corresponding to the players' anaerobic threshold (3.49+/-0.60mmolL(-1)). However, an important part of the game (14.4%) contained activities with sudden HR increases above the anaerobic threshold. Mean BLa accumulation at the end of each game period was 3.93+/-1.64mmolL(-1). Individual lactate values varied from 2.0 to 8.3mmolL(-1). Goalkeeper exercise intensity reached its peak value (152.5+/-10.1bpm) whenever his team competed with one player less due to player exclusion. No significant differences were found in HR, BLa and the percentage of time spent in each of the activity categories between game periods. In conclusion, goalkeeper's game can be described as of intermittent nature with great variability in the intensity performed. The greater part of the game is associated with a low aerobic demand while an important part of the game contains activities with sudden HR increases above the anaerobic threshold implying also a considerable demand on anaerobic metabolism. The intensity of exercise of the goalkeeper does not differ from period to period. PMID:18077216

Platanou, T

2008-02-20

22

Physiological characteristics of serotonin transporters on rat platelets  

Microsoft Academic Search

Physiological characteristics of serotonin (5-hydroxytryptamine, 5HT) transport through the platelet membrane was investigated in Wistar rats with our recently developed method permitting repetitive measurements of transporter kinetics in individual animals. Full kinetic analysis in the population of 91 animals revealed Michaelis constant (Km) of 0.158±0.025 ?M and maximal velocity (Vmax) of 5HT uptake of 225±32 pmol per 108platelets min?1 (mean±S.D.).

Lipa ?i?in-Šain; Ana Fröbe; Branimir Jernej

1998-01-01

23

THE PHYSIOLOGICAL EFFECTS OF WATER vs. GATORADE DURING PROLONGED EXERCISE  

Microsoft Academic Search

Danielson , A.R., Morris, L., Neiderhauser, L., Stanek, K., Wolter, J. The Physiological effects of water vs. Gatorade during prolonged exercise. J. Undergrad. Kin. Res. 2006; 1(1):15-22. The purpose of this study was to investigate the physiological effects of water vs. Gatorade during prolonged exercise. Subjects consisted of 10 recreationally active females between the ages 19 and 22. Each participant

Ashley Danielson; Lynn Morris; Lindi Neiderhauser; Kasey Stanek; Jennifer Wolter

24

Anthropometric and physiological characteristics of junior elite volleyball players  

PubMed Central

Objectives To investigate the anthropometric and physiological characteristics of junior elite volleyball players. Method Twenty five national level volleyball players (mean (SD) age 17.5 (0.5) years) were assessed on a number of physiological and anthropometric variables. Somatotype was assessed using the Heath?Carter method, body composition (% body fat, % muscle mass) was assessed using surface anthropometry, leg strength was assessed using a leg and back dynamometer, low back and hamstring flexibility was assessed using the sit and reach test, and the vertical jump was used as a measure of lower body power. Maximal oxygen uptake was predicted using the 20?m multistage fitness test. Results Setters were more ectomorphic (p<0.05) and less mesomorphic (p<0.01) than centres. Mean (SD) of somatotype (endomorphy, mesomorphy, ectomorphy) for setters and centres was 2.6 (0.9), 1.9 (1.1), 5.3 (1.2) and 2.2 (0.8), 3.9 (1.1), 3.6 (0.7) respectively. Hitters had significantly greater low back and hamstring flexibility than opposites. Mean (SD) for sit and reach was 19.3 (8.3)?cm for opposites and 37 (10.7)?cm for hitters. There were no other significant differences in physiological and anthropometric variables across playing positions (all p>0.05). Conclusion Setters tend to be endomorphic ectomorphs, hitters and opposites tend to be balanced ectomorphs, whereas centres tend to be ectomorphic mesomorphs. These results indicate the need for sports scientists and conditioning professionals to take the body type of volleyball players into account when designing individualised position specific training programmes.

Duncan, M J; Woodfield, L; al-Nakeeb, Y

2006-01-01

25

Environmental Physiology of Fresh Water Planktonic Crustacea.  

National Technical Information Service (NTIS)

The addition of heated effluents to fresh water environments could affect ecosystem energetics by its effects on metabolism. The poikilothermic planktonic crustaceans presumably have a temperature-dependent metabolism. However, metabolic compensation coul...

K. B. Armitage

1972-01-01

26

The Clinical Physiology of Water Metabolism  

PubMed Central

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.

Weitzman, Richard E.; Kleeman, Charles R.

1980-01-01

27

Young long distance runners. Physiological and psychological characteristics.  

PubMed

This study presents the physiological and psychological characteristics and the running histories of 16 subjects who began long distance running at age 4-12 years. Running duration was 3-15 years (mean 8.4 +/- 3.6 yrs). Seven children completed 41 marathons, seven 30-mile races, and eight 60-mile races. The other nine competed at shorter distances. All trained at 30-105 miles/week. Two stress fractures, one back sprain and one knee injury occurred. Athletes who reported injuries from recollection may have underreported some injuries. At age 15.4 +/- 4.2 years bone age was 15.3 +/- 2.6 years and height was at 51 +/- 26.0 percentile. Athletes had larger left ventricular diastolic diameter, higher max O2 uptake, and delayed onset of anaerobic metabolism compared to controls. Psychological profile: IQ = 121 +/- 11, scholastic grade point average (GPA) (n = 13) was less than or equal to 3.0 in four, 3.6-3.9 in four, and 4.0 in five. Cattell 16 personality factor (PF): Seven scored above the 85th percentile on boldness, warmth, conformity, sensitivity, dominance, and high drive with tension. Eight scored above the 93rd percentile for self discipline and emotional stability. Human Figure Drawing showed a distorted body image in seven. Two developed anorexia nervosa, and another girl committed suicide. Thus, high physical fitness and no growth retardation were observed. These runners, however, shared distinct positive and negative personality characteristics. The relatively high incidence of severe psychological disorders possibly suggests a need for psychological screening for young children entering a strenuous training program and for close monitoring for development of psychological problems during the program. PMID:2805554

Nudel, D B; Hassett, I; Gurian, A; Diamant, S; Weinhouse, E; Gootman, N

1989-11-01

28

Physiological and perceptual responses to backward and forward treadmill walking in water  

Microsoft Academic Search

We compared physiological and perceptual responses, and stride characteristics while walking backward in water with those of walking forward in water. Eight males walked on an underwater treadmill, immersed to their xiphoid process level. Oxygen uptake (V?O2), respiratory exchange ratio (R), heart rate (HR), minute ventilation (V?E), blood lactate concentration (BLa), ratings of perceived exertion (RPE: for breathing and legs,

Kenji Masumoto; Ayako Hamada; Hiro-omi Tomonaga; Kana Kodama; Yuko Amamoto; Yoshiko Nishizaki; Noboru Hotta

2009-01-01

29

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...

30

Physiological Effects of Trace Elements and Chemicals in Water  

ERIC Educational Resources Information Center

|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.…

Varma, M. M.; And Others

1976-01-01

31

Physiological response to water immersion: a method for sport recovery?  

PubMed

Recovery from exercise can be an important factor in performance during repeated bouts of exercise. In a tournament situation, where athletes may compete numerous times over a few days, enhancing recovery may provide a competitive advantage. One method that is gaining popularity as a means to enhance post-game or post-training recovery is immersion in water. Much of the literature on the ability of water immersion as a means to improve athletic recovery appears to be based on anecdotal information, with limited research on actual performance change. Water immersion may cause physiological changes within the body that could improve recovery from exercise. These physiological changes include intracellular-intravascular fluid shifts, reduction of muscle oedema and increased cardiac output (without increasing energy expenditure), which increases blood flow and possible nutrient and waste transportation through the body. Also, there may be a psychological benefit to athletes with a reduced cessation of fatigue during immersion. Water temperature alters the physiological response to immersion and cool to thermoneutral temperatures may provide the best range for recovery. Further performance-orientated research is required to determine whether water immersion is beneficial to athletes. PMID:16937951

Wilcock, Ian M; Cronin, John B; Hing, Wayne A

2006-01-01

32

Water as an essential nutrient: the physiological basis of hydration.  

PubMed

How much water we really need depends on water functions and the mechanisms of daily water balance regulation. The aim of this review is to describe the physiology of water balance and consequently to highlight the new recommendations with regard to water requirements. Water has numerous roles in the human body. It acts as a building material; as a solvent, reaction medium and reactant; as a carrier for nutrients and waste products; in thermoregulation; and as a lubricant and shock absorber. The regulation of water balance is very precise, as a loss of 1% of body water is usually compensated within 24 h. Both water intake and water losses are controlled to reach water balance. Minute changes in plasma osmolarity are the main factors that trigger these homeostatic mechanisms. Healthy adults regulate water balance with precision, but young infants and elderly people are at greater risk of dehydration. Dehydration can affect consciousness and can induce speech incoherence, extremity weakness, hypotonia of ocular globes, orthostatic hypotension and tachycardia. Human water requirements are not based on a minimal intake because it might lead to a water deficit due to numerous factors that modify water needs (climate, physical activity, diet and so on). Water needs are based on experimentally derived intake levels that are expected to meet the nutritional adequacy of a healthy population. The regulation of water balance is essential for the maintenance of health and life. On an average, a sedentary adult should drink 1.5 l of water per day, as water is the only liquid nutrient that is really essential for body hydration. PMID:19724292

Jéquier, E; Constant, F

2009-09-02

33

Human red blood cells' physiological water exchange with the plasma.  

PubMed

In the present paper, fundamental issues related to the mechanisms of human red blood cells' physiological water exchange with the plasma (for the stationary conditions) have been discussed. It has been demonstrated, on the basis of mechanistic transport equations for membrane transport that red blood cells are capable of exchanging considerable amounts of water with the plasma. Water absorption is osmosis-driven, and its removal occurs according to the hydromechanics principle, i.e. is driven by the turgor pressure of red blood cells. This newly-acquired knowledge of these issues may appear highly useful for clinical diagnosis of blood diseases and blood circulation failures. PMID:16358974

Kargol, M; Kargol, A; Przestalski, M; Siedlecki, J; Karpi?ska, M; Rogowski, M

2005-01-01

34

[Effects of flooding on the photosynthetic physiology characteristics of Pterocarya stenoptera seedlings].  

PubMed

Three water treatments (control, CK; continuous flooding, CF; and periodic flooding, PF) were installed to simulate the soil moisture change of the riparian zone in the Three Gorges Reservoir (TGR) region of China to study the physiological and ecological adaptation mechanisms of the native plant species Pterocarya stenoptera seedlings to the soil moisture change. All the water treatments had significant effects on the photosynthesis, biomass accumulation, and growth of the P. stenoptera seedlings. As compared with those in CK, the seedling's net photosynthetic rate (Pn) and stomatal conductance (gs) in treatments CF and PF were significantly lower while the intercellular carbon dioxide concentration was significantly higher, and the Pn and gs in CF and PF declined initially followed by a gradual recovery or tended to be stable. With the extension of treatment time, the total biomass and root-, stem-, and leaf biomass, plant height, and basal diameter in CF and PF all presented an increasing trend. Throughout the experimental period, the total biomass, root- and leaf biomass, and plant height in CF and PF and the stem biomass in PF were significantly lower than those in CK, whereas the stem biomass in CF had no significant difference with that in CK, though the basal diameter in CF was significantly higher than that in CK. It was suggested that the P. stenoptera seedlings had the physiological and ecological characteristics of tolerating flooding rather than flooding-drought alteration. PMID:23755480

Wang, Chao-Ying; Li, Chang-Xiao; Zhang, Ye

2013-03-01

35

Physiology  

ERIC Educational Resources Information Center

|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…

Kay, Ian

2008-01-01

36

Respiratory and Physiological Characteristics in Subpopulations of Great Basin Cheatgrass  

Microsoft Academic Search

Cheatgrass (Bromus tectorum L.) is a dominant weed that has increased the frequency of wildfire in the Great Basin since its introduction approximately 106 years ago. Characteristics of respiratory metabolism were examined in eleven subpopulations from different habitats. Seeds from each subpopulation were germi- nated (4mm radicle) and metabolic heat rates (q) and respiration rates (RCO2) determined calorimetrically at 5

V. Wallace McCarlie; Lee D. Hansen; Bruce N. Smith

37

Physical and Chemical Water Characteristics  

Microsoft Academic Search

An outline is given of the physical and chemical features of waters in the Nile system, including headwater lakes. Temperature\\u000a is governed by the large range of latitude and altitude, and is mostly within 15–30°C. Differences with depth can be appreciable\\u000a under conditions of low to minimal flow and in deeper water columns. They introduce a density stratification with both

Jack F. Talling

38

Thermal characteristics of running waters  

Microsoft Academic Search

This chapter reviews available data on thermal conditions prevailing in lotic ecosystems of the Southern Hemisphere. The primary factors (hydrology, climate, insolation) that interact to determine the thermal régime are examined in the context of southern waters. Maximum temperatures are plotted against annual ranges for equatorial (0–10° latitude), tropical (10–231\\/2° latitude), and temperate sites. In regions with seasonal climates, running

J. V. Ward

1985-01-01

39

Genotypic differences in some physiological characteristics during cotton fiber thickening and its influence on fiber strength  

Microsoft Academic Search

Cotton (Gossypium L.) fiber strength is linked with many complex physiological and biochemical processes in the stage of secondary fiber cell\\u000a wall thickening. With the aim of further exploiting of the relationship between fiber strength and genotypic differences in\\u000a physiological characteristics, the experiment was implemented in Nanjing, China (in the lower reach of Yangtze River Valley\\u000a in China) at the

Wenjing Zhang; Hongmei Shu; Hongbiao Hu; Binglin Chen; Youhua Wang; Zhiguo Zhou

2009-01-01

40

Physiological characteristics of the best Eritrean runners—exceptional running economy  

Microsoft Academic Search

Despite their young age, limited training history, and lack of running tradition compared with other East African endurance athletes (e.g., Kenyans and Ethiopians), male endurance runners from Eritrea have recently attained important running successes. The purposes of our study were (i) to document the main physical and physiological characteristics of elite black Eritrean distance runners (n = 7; age: 22

Alejandro Lucia; Jonathan Esteve-Lanao; Jesus Olivan; Felix Gomez-Gallego

41

The influence of low-intensity ultrasonic on some physiological characteristics of Saccharomyces cerevisiae  

Microsoft Academic Search

In this paper, we studied about some vital physiological characteristics of Saccharomyces cerevisiae at logarithmic phase under ultrasonic stimulation including the stimulated conditions of the 24 kHz in frequency, 2 W in the power efficiency, 1 s for every 15 s in the stimulation time and 30 min in the duration cycle. After S. cerevisiae was inoculated and stimulated for

Shi Lanchun; Wang Bochu; Zhu Liancai; Liu Jie; Yang Yanhong; Duan Chuanren

2003-01-01

42

Root physiological and morphological characteristics of 24 rice varieties selected for diverse grain mineral  

Technology Transfer Automated Retrieval System (TEKTRAN)

To accumulate a mineral in the grain, a plant must first absorb that mineral from the soil. Root physiological characteristics, such as exudation of organic acids or oxygen, impact the availability, solubility and mobility of minerals in the soil, ultimately impacting the amount of minerals absorbe...

43

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

PubMed Central

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.

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

2012-01-01

44

Physiological characteristics of cyanobacteria in pulp and paper waste-treatment systems  

Microsoft Academic Search

An investigation was made into the physiological characteristics of the extensive cyanobacterial communities in pulp and paper secondary waste-treatment systems, including the capacity of isolates to biodegrade organic contaminants in these systems. Although pulp and paper waste-treatment systems were found to be severely light-limited, photosynthesis-irradiance curves indicated that shade-adapted cyanobacterial communities could fix conspicuous amounts of inorganic carbon via photosynthesis.

A. E. Kirkwood; C. Nalewajko; R. R. Fulthorpe

2003-01-01

45

Characteristics of elite open-water swimmers.  

PubMed

Open-water swimming (5, 10, and 25 km) has many unique challenges that separate it from other endurance sports, like marathon running and cycling. The characteristics of a successful open-water swimmer are unclear. The purpose of this study was to determine the physical and metabolic characteristics of a group of elite-level open-water swimmers. The open-water swimmers were participating in a 1-week training camp. Anthropometric, metabolic, and blood chemistry assessments were performed on the athletes. The swimmers had a VO(2)peak of 5.51 +/- 0.96 and 5.06 +/- 0.57 ml.kg(-1).min(-1) for males and females, respectively. Their lactate threshold (LT) occurred at a pace equal to 88.75% of peak pace for males and 93.75% for females. These elite open-water swimmers were smaller and lighter than competitive pool swimmers. They possess aerobic metabolic alterations that resulted in enhanced performance in distance swimming. Trainers and coaches should develop dry-land programs that will improve the athlete's muscular endurance. Furthermore, programs should be designed to increase the LT velocity as a percentage of peak swimming velocity. PMID:15142018

VanHeest, Jaci L; Mahoney, Carrie E; Herr, Larry

2004-05-01

46

Does stream water chemistry reflect watershed characteristics?  

PubMed

In this study, we investigated the relationships between stream water chemistry and watershed characteristics (topography--mean altitude and slope; climate--mean annual temperature and precipitation; geology--geochemical reactivity; land cover; inhabitation--population density, road density and number of municipalities). We analyzed the concentrations of the major anions (Cl, F, NO3, SO4, SiO2), cations (Ca, Mg, Na, K, Mn, Fe, Al), trace elements (Li, Sr, Cu), ABS245, TDP (total dissolved phosphorus), pH, and conductivity at 3,220 diverse watersheds covering a wide variety of watershed characteristics in the Czech Republic. We used marginal and partial multivariate analyses to reveal the most important variables. The partial analysis showed that only 14% of the variance could be assigned to a specific factor and that 41% of the variance is shared among the factors, which indicated complex interactions between the watershed characteristics. PMID:23142877

Chuman, Tomáš; Hruška, Jakub; Oulehle, Filip; Gürtlerová, Pavla; Majer, Vladimír

2012-11-11

47

Hydrophysical correlation and water mass indication of optical physiological parameters of picophytoplankton in Prydz Bay during autumn 2008.  

PubMed

Flow cytometry (FCM) is efficient in detecting both abundance and optical physiological parameters including cell size and cellular carbon content-side scatter (SSC), carotenoids-green and orange fluorescence (FL1 and FL2), and red fluorescence-chlorophylls (FL3) can be obtained by FCM. The utilization of these physiological parameters in indicating water masses in Prydz Bay was investigated for the first time. Picophytoplankton were very sensitive to hydrophysical changes and present distinct characteristics of water masses: Picophytoplankton in water closer to the Amery Ice Shelf were more affected by salinity than by temperature, while temperature became more important than salinity the nearer the picophytoplankton were to the deep sea. The picophytoplankton dealt with declines in light by increasing the size of cells, which increase the fixation of carbon. This can also be increased by high temperature and salinity. Pure water masses can increase the content of chlorophylls and cellular carbon. Generally, the distributions of all the five parameters at upper water depths were less affected by temperature and salinity than by water masses; and these parameters can be as indicators to Summer Surface Water (SSW), Winter Water (WW) and Continental Shelf Water (CSW). PMID:23098920

Zhang, Fang; Ma, Yuxin; Lin, Ling; He, Jianfeng

2012-10-23

48

Physiological responses of argentine peanut varieties to water stress. Water uptake and water use efficiency  

Microsoft Academic Search

The water extraction capability and water use efficiency (WUE) of two argentine peanut varieties Florman INTA and Manfredi 393 INTA, respectively classed as drought-sensitive and drought-tolerant were compared. The experiment was grown at two different regimes of water supply. Between 47 and 113 days after sowing (DAS) half of the crop was irrigated, while the other half received no water.

D. J Collino; J. L Dardanelli; R Sereno; R. W Racca

2000-01-01

49

The physiology and toxicology of salmonid eggs and larvae in relation to water quality criteria  

Microsoft Academic Search

The purpose of this review is to collate physiological knowledge on salmonid eggs and larvae in relation to water quality criteria. Salmonid genera reviewed include Coregonus, Thymallus, Salvelinus, Salmo, and Oncorhynchus spp. When physiological data for salmonids are lacking, the zebrafish and medaka models are included. The primary focus is on the underlying mechanisms involved in the hydro-mineral, thermal, and

Roderick Nigel Finn

2007-01-01

50

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

PubMed Central

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).

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

2009-01-01

51

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...

52

Maximal and submaximal physiological responses to adaptation to deep water running  

Microsoft Academic Search

The aim of the study was to compare physiological responses between runners adapted and not adapted to deep water running at maximal intensity and the intensity equivalent to the ventilatory threshold. Seventeen runners, either adapted (n = 10) or not adapted (n = 7) to deep water running, participated in the study. Participants in both groups undertook a maximal treadmill running and deep water

Liane B. Azevedo; Mike I. Lambert; Paulo S. Zogaib; Turibio L. Barros Neto

2010-01-01

53

Effects of Saline Water on Growth and Physiology of Bell Pepper Seedlings  

Microsoft Academic Search

Use of saline water to produce pepper (Capsicum annuum L.) transplants could have deleterious effects on their growth and physiology because they are moderately sensitive to salinity. Various levels of saline water (0.5, 1.5, 2.5, 3.5, and 4.5 dS·m) were applied to examine effects on growth and physiology of bell pepper transplants grown in containerized trays under greenhouse conditions. There

Dagobiet Morales-Garcia; Katrine A. Stewart; Philippe Seguin

2008-01-01

54

Water Extract of Alnus nepalensis D.Don. to the Seeds Germination of Pinus yunnanensis Faranch Effects of Physiological and Biochemical Mechanism  

Microsoft Academic Search

Study effect of different concentrations (1?10,1?50,1?100,1?200)water extract from Alnus nepalensis D.Don on the seed germination and allelopathic physiology and biochemistry characteristics effects of Pinus yunnanensis Faranch. Pre-test tube method was used with qualitative analysis of organic components of water extract from A.nepalensis D.Don. Results showed that water extract of A. nepalensis D.Don contains amino acids and proteins, organic acids, sugars,

Xiaoli Wang; Zilin Cao

2010-01-01

55

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

Microsoft Academic Search

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°C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve

R. W. Gusztak; R. A. MacArthur; K. L. Campbell

2005-01-01

56

Physiological and biochemical responses of peanut genotypes to water deficit  

Microsoft Academic Search

The effects of drought on water relations, gas exchanges, solutes accumulation, and catalase (CAT), ascorbato peroxidase (APX), and guaiacol peroxidase (GPX) activities were studied in five Arachis genotypes, grown under control or withholding water conditions. Drought stress reduced plant growth of all genotypes; the genotypes A. duranensis 7988 and A. stenosperma SV2411 being characterized as the most drought-sensitive and A.

André D. Azevedo Neto; Rejane J. M. C. Nogueira; Péricles A. Melo Filho; Roseane C. Santos

2010-01-01

57

Cold Water Fatalities: An Overview of Physiological Responses.  

ERIC Educational Resources Information Center

Cold water fatalities are described and defined, including drownings, trauma, hydrocution and hypothermia. The levels of hypothermia are outlined, and symptoms and steps to stop and reverse hypothermia are described. (DS)

Bernhartsen, J. C.; Schlenker, Richard

1981-01-01

58

Comparison of urinary component levels in 4 strains of mice with different physiological characteristics.  

PubMed

Changes in urinary component levels before, during and after reproduction were examined with 1H-nuclear magnetic resonance (NMR) in four strains of female mice with different mammary tumour potential and related characteristics (SHN, SLN, GR/A and C3H/He). Regardless of the variations in these changes among the strains, the urinary component levels reflected physiological changes during reproduction and some strain-specific characteristics. The urinary excretion of citrate, 2-oxoglutarate and lactate increased from the virginal stage to pregnancy and declined during lactation in all strains, indicating a marked change in sugar metabolism during reproduction. SHN and SLN, which are from the same basal stock, showed a similar pattern and the level, of several components were lower than those of GR/A and C3H/He. The levels of some lower components were compensated for by higher urine excretion. The levels of taurine and betaine, both essential for fetal and pup growth, increased at lactation in only GR/A, reflecting the poorer pup growth observed in this strain. Finally, the 1H-NMR method was useful to estimate not only the metabolic but also the physiological changes of the animals without invasion, pain or distress and would thus contribute to animal welfare in the animal experiments. PMID:9179602

Yasuda, M; Tsunoda, S; Nagasawa, H

59

Time-motion analysis, heart rate, and physiological characteristics of international canoe polo athletes.  

PubMed

Forbes, SC, Kennedy, MD, and Bell, GJ. Time-motion analysis, heart rate, and physiological characteristics of international canoe polo athletes. J Strength Cond Res 27(10): 2816-2822, 2013-To evaluate the time international canoe polo players spend performing various game activities, measure heart rate (HR) responses during games, and describe the physiological profile of elite players. Eight national canoe polo players were videotaped and wore HR monitors during 3 games at a World Championship and underwent fitness testing. The mean age, height, and weight were 25 ± 1 years, 1.82 ± 0.04 m, and 81.9 ± 10.9 kg, respectively. Time-motion analysis of 3 games indicated that the players spent 29 ± 3% of the game slow and moderate forward paddling, 28 ± 5% contesting, 27 ± 5% resting and gliding, 7 ± 1% turning, 5 ± 1% backward paddling, 2 ± 1% sprinting, and 2 ± 1% dribbling. Sixty-nine (±20)% of the game time was played at an HR intensity above the HR that corresponded to the ventilatory threshold (VT) that was determined during the peak V[Combining Dot Above]O2 test. Peak oxygen uptake and VT were 3.3 ± 0.3 and 2.2 ± 0.3 L·min, respectively, on a modified Monark arm crank ergometer. Arm crank peak 5-second anaerobic power was 379 W. The majority of the time spent during international canoe polo games involved slow-to-moderate forward paddling, contesting for the ball, and resting and gliding. Canoe polo games are played at a high intensity indicated by the HR responses, and the physiological characteristics suggest that these athletes had high levels of upper body aerobic and anaerobic fitness levels. PMID:23287835

Forbes, Scott C; Kennedy, Michael D; Bell, Gordon J

2013-10-01

60

Human physiological responses to immersion into water of different temperatures  

Microsoft Academic Search

To differentiate between the effect of cold and hydrostatic pressure on hormone and cardiovascular functions of man, a group\\u000a of young men was examined during 1-h head-out immersions in water of different temperatures (32°C, 20°C and 14°C). Immersion\\u000a in water at 32°C did not change rectal temperature and metabolic rate, but lowered heart rate (by 15%) and systolic and diastolic

P. Šrámek; M. Šime?ková; L. Janský; J. Šavlíková; S. Vybíral

2000-01-01

61

In situ Determination of Physiological States Under Conditions Characteristic of the Subseafloor Microbial Biosphere  

NASA Astrophysics Data System (ADS)

Studies of water samples from the deep sea have revealed organisms specifically adapted to the low temperatures (~2° C) and elevated pressures (~100 MPa) native to these environments and elucidated genetic and physiological adaptations of life to high pressures. Investigation of the subsurface biosphere, at pressures exceeding those of the deep sea, has pushed the depth limits of microbial ecosystems to at least 1000 meters below the seafloor and 3-4 km into the continental lithosphere. In many of these environments, organisms are confronted with multiple stressors including not only high pressures, but high temperatures and low energy fluxes. Subsurface microorganisms live at a precarious boundary between geologically-supported growth and cell death and remineralization. As a result of these factors the calculated average growth rates of these organisms have challenged our notions of what is biologically possible. A limitation to our study of deep ecosystems has been an inability to accurately characterize microbial physiology under conditions found in subsurface habitats. This paper describes a strategy to distinguish the physiological status of microorganisms indigenous to the deep subseafloor at environmentally relevant temperatures (50 - 200° C) and pressures (30 - 300 MPa). Preliminary results using chemolithoautotrophic bacteria and hyperthermophilic Archaea show that four distinct physiological states (active and growing, active but non-growing, viable but inactive, and dead) can be distinguished in situ using biomolecular probes coupled to geochemical measurements. Further refinements of this approach can be used to expand our understanding of microbial adaptations to high pressure environments, and be linked to both genetic and geochemical studies at high pressure. The data produced by such experiments will be important to deciphering both the extent and the biogeochemical consequences of a deep subsurface biosphere.

Schrenk, M. O.

2008-12-01

62

Differential physiological effects during tonic painful hand immersion tests using hot and ice water  

Microsoft Academic Search

The cold pressor test (CPT) is an empirically validated test commonly used in research on stress, pain and cardiovascular reactivity. Surprisingly, the equivalent test with water heated to noxious temperatures (hot water immersion test, HIT) has not been thoroughly investigated. The aim of the present study was to characterize the physiological effects and psychophysics of both tests and to analyze

Anouk Streff; Linn K. Kuehl; Gilles Michaux; Fernand Anton

2010-01-01

63

Physiology of Acidophilic Bacteria of Acid Mine Water.  

National Technical Information Service (NTIS)

Two new acidophilic bacteria (strains M-1 and M-2) were isolated from coal mine waters, characterized, and placed in the genus Pseudomonas, as Pseudomonas acidophila, sp. n. Obligate acidophiles unable to grow at neutrality, they are capable of rapid and ...

H. L. Manning T. M. Cook

1972-01-01

64

Effect of Meloidogyne ethiopica parasitism on water management and physiological stress in tomato  

Microsoft Academic Search

Root-knot nematodes (RKN) are obligate endoparasites that severely damage the host root system. Nutrient and water uptake\\u000a are substantially reduced in infested plants, resulting into altered physiological processes and reduced plant growth. The\\u000a effect of nematode infestation on the morphological changes of roots and subsequent physiological plant responses of infested\\u000a tomatoes with the RKN Meloidogyne ethiopica was studied in a

Polona Strajnar; Saša Širca; Gregor Urek; Helena Šircelj; Peter Železnik; Dominik Vodnik

65

Behavioral and physiological characteristics of Indian and Chinese-Indian hybrid rhesus macaque infants.  

PubMed

Strain differences in temperament and physiology have been reported for several animal species, but nonhuman primates have not been well studied in this regard. We assessed behavioral and physiology in Chinese-Indian hybrid (n = 13) and Indian-origin (n = 29) nursery-reared rhesus monkey infants. Previous data indicate that Chinese-origin and Chinese-Indian hybrid rhesus exhibit more aggression directed toward humans and conspecifics and are more irritable in response to neonatal assessment procedures than are Indian-derived rhesus. In addition, in rhesus adults, low levels of cerebrospinal fluid 5-HIAA have been correlated with impulsivity, aggressive behavior, and diminished social competence. We therefore hypothesized that hybrid infants would exhibit more behavioral and adrenocortical reactivity in the home cage and during social separations, would be less sociable in their peer groups, and would exhibit lower CSF 5-HIAA levels than Indian-derived monkeys. Blood and cerebrospinal fluid samples were obtained on Days, 14, 30, 60, 90, 120, and 150 of life, and prior to and during social separations at 6 months of age. Behavioral observations were conducted in the home cage and during the separation condition. No differences in behavior were observed between hybrid and Indian-derived animals in the home cage. Indian-derived and hybrid infants exhibited diverging patterns of behavioral reactivity across the 4 weeks of the repetitive social-separation procedure, and during reunion periods. Although plasma cortisol levels were sensitive to the testing conditions, no group differences were observed. CSF 5-HIAA declined over time for all monkeys, and hybrid animals exhibited significantly lower 5-HIAA levels than Indian monkeys beginning at 6 months of age. These findings are consistent with the known behavioral and physiological characteristics of Chinese-origin adult rhesus. PMID:9222116

Champoux, M; Higley, J D; Suomi, S J

1997-07-01

66

Effects of water reuse and stocking density on water quality, blood physiology and growth rate of juvenile cod ( Gadus morhua)  

Microsoft Academic Search

The effects of increasing degree of water reuse on water quality and subsequent growth and physiological response in juvenile Atlantic cod, Gadus morhua, were examined. Fish with a mean (SD) initial weight of 11.7 (1.6)g, were reared for 63 days in tanks connected in series, where the water (10.1±1.5 °C) was reused from tank to tank (n=4 with replicates) with reoxygenation

Atle Foss; Torstein Kristensen; Åse Åtland; Helge Hustveit; Halvard Hovland; Anders Øfsti; Albert K. Imsland

2006-01-01

67

Anthropometric and physiological characteristics in young afro-Caribbean swimmers. A preliminary study.  

PubMed

The authors investigated the anthropometric and physiological characteristics of young Guadeloupian competitive swimmers in relation to swimming performance and compared the abilities of these children with those of the young white swimmers reported in the literature. All 2004 competitive swimmers between 10 and 14 y old (126 children, 61 boys and 65 girls, 12.0 ± 1.3 y) from Guadeloupe underwent anthropometric measurements and physiological and performance testing. Six boys on the French national swimming team are referred to hereafter as the 2011 elite subgroup. Anthropometric parameters, a jump-and-reach test, glide, and estimated aerobic power (eVO2max) were assessed in terms of swimming-performance analysis through a 400-m test. This study demonstrated that the Guadeloupian swimmers had more body fat than most age-matched white swimmers but had very poor hydrostatic lift; they had higher peak jump height and they swam as well as their white counterparts. The variability in 400-m performance between subjects was best described by glide, age, and eVO2max. Compared with the group of boys with the same age, the 2011 elite subgroup was significantly better for arm span, peak jump height, glide, and 400-m and 15-m performances. Further research is needed to investigate motor organization and energy cost of swimming in Afro-Caribbean swimmers. PMID:23006763

Hue, Olivier; Antoine-Jonville, Sophie; Galy, Olivier; Blonc, Stephen

2012-09-19

68

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

PubMed

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

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

2013-08-20

69

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

PubMed Central

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.

SASAKI, Satohiko

2008-01-01

70

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

PubMed

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

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

2013-11-01

71

Physiological analysis of common bean (Phaseolus vulgaris L.) cultivars uncovers characteristics related to terminal drought resistance.  

PubMed

Terminal drought is a major problem for common bean production because it occurs during the reproductive stage, importantly affecting seed yield. Diverse common bean cultivars with different drought susceptibility have been selected from different gene pools in several drought environments. To better understand the mechanisms associated with terminal drought resistance in a particular common bean race (Durango) and growth habit (type-III), we evaluated several metabolic and physiological parameters using two cultivars, Bayo Madero and Pinto Saltillo, with contrasting drought susceptibility. The common bean cultivars were submitted to moderate and severe terminal drought treatments under greenhouse conditions. We analyzed the following traits: relative growth rate, photosynthesis and transpiration rates, stomatal conductance, water-use efficiency, relative water content, proline accumulation, glycolate oxidase activity and their antioxidant response. Our results indicate that the competence of the drought-resistant cultivar (Pinto Saltillo) to maintain seed production upon terminal drought relies on an early response and fine-tuning of stomatal conductance, CO? diffusion and fixation, and by an increased water use and avoidance of ROS accumulation. PMID:22579941

Rosales, Miguel A; Ocampo, Edilia; Rodríguez-Valentín, Rocío; Olvera-Carrillo, Yadira; Acosta-Gallegos, Jorge; Covarrubias, Alejandra A

2012-04-21

72

Metabolic and Physiological Characteristics of Novel Cultivars from Serpentinite Seep Fluids  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

73

Root water uptake and transport: using physiological processes in global predictions.  

PubMed

Plant water loss, regulated by stomata and driven by atmospheric demand, cannot exceed the maximum steady-state supply through roots. Just as an electric circuit breaks when carrying excess current, the soil-plant continuum breaks if forced to transport water beyond its capacity. Exciting new molecular, biophysical and ecological research suggests that roots are the weakest link along this hydraulic flow path. We attempt here to predict rooting depth and water uptake using the hydraulic properties of plants and the soil, and also to suggest how new physiological tools might contribute to larger-scale studies of hydraulic lift, the water balance and biosphere-atmosphere interactions. PMID:11077257

Jackson, R B; Sperry, J S; Dawson, T E

2000-11-01

74

Physiological parameters of desert truffle mycorrhizal Helianthemun almeriense plants cultivated in orchards under water deficit conditions  

Microsoft Academic Search

Physiological parameters of mycorrhizal symbiosis by Helianthemum almeriense and Terfezia claveryi in orchards were characterized under water deficit conditions. Our orchard included 40 mycorrhizal and 40 nonmycorrhizal plants. Only mycorrhizal plants survived at the beginning of the experimental period, indicating dependency on fungal symbionts in roots for survival. Drought stress significantly affected the mycorrhizal colonization percentage which was 70% in

Asunción Morte; Alfonso Navarro-Ródenas; Emilio Nicolás

2010-01-01

75

Morphological and Physiological Characters of Aloe vera Subjected to Saline Water Irrigation  

Microsoft Academic Search

Aloe vera is grown in arid climates where salinity can limit plant growth and development. A study was conducted to examine the morphological and physiological characters under salt stress. Plants were cultivated in pots and irrigated with freshwater (EC 450 ?s cm) or saline lake water (EC 3, 6, 9, 12, 15, 18, or 21 dS m). Results indicated that

Ramin Rahimi-Dehgolan; Zeinolabedin Tahmasebi Sarvestani; Shams Ali Rezazadeh; Aria Dolatabadian

2012-01-01

76

MORPHOLOGICAL AND PHYSIOLOGICAL PLASTICITY OF ISATIS TINCTORIA: RESPONSES TO CONTRASTING LIGHT, SOIL-NITROGEN, AND WATER  

Technology Transfer Automated Retrieval System (TEKTRAN)

We evaluated the magnitude of morphological and physiological plasticity in response to contrasting above and below ground resources for the invasive weed, Isatis tinctoria L. (dyer's woad). Plants were grown under low and high levels of light (shade [50% of ambient] and full sun), soil water (50 a...

77

Quality characteristics and safety of smoke-flavoured water  

Microsoft Academic Search

Smoke-flavoured water is produced in Ghana by filling a previously smoked container with potable water and allowing the water to condition with the smoke to attain a characteristic rain water flavour. Owing to the current knowledge on the toxicity, carcinogenicity and other safety issues of some smoke-constituents, the commercial production of the product is becoming a public health concern. This

Kwaku Tano-Debrah; Joanne Amamoo-Otchere; A. Y. Karikari; Charles Diako

2007-01-01

78

Physiological characteristics of wild Atlantic salmon post-smolts during estuarine and coastal migration  

USGS Publications Warehouse

Changes were measured in some of the major physiological variables associated with seawater adaptability, growth and energetics in wild Atlantic salmon Salmo salar smolts and post-smolts migrating from the river and through the estuary, fjord and coastal areas in the River Orkla and the Trondheimsfjord, Norway during late May to early June. Gill Na+,K+-ATPase activity increased to levels of 12-16 ??mol ADP mg protein-1 h -1 in post-smolts caught in higher salinity zones, probably representing long-term levels of Atlantic salmon post-smolts in oceanic conditions. Muscle moisture was regulated within narrow limits (77.7-78.7%) in fish from all zones during both years, suggesting that post-smolts adapt to marine conditions without any long-term disturbance of hydro-mineral balance. Lipid and glycogen content showed a general trend towards depletion from the river, through the fjord and into the ocean. There was, however, no significant change in protein content. The present results confirm that smolts are naturally 'energy deficient' during downstream migration, and suggest that post-smolts also mobilize energy reserves during their early marine phase, while protein is allocated for somatic growth. Plasma growth hormone (GH) levels increased transiently during passage through the estuary and fjord, with lower levels observed in post-smolts caught off-shore, i.e. in fish which were feeding on marine prey and had adapted to the marine environment. These physiological changes may confer substantial selective advantages during the critical early marine phase of anadromous salmonids, and hence are adaptive for long-term survival in sea water. ?? 2003 The Fisheries Society of the British Isles.

Stefansson, S. O.; Bjornsson, B. Th.; Sundell, K.; Nyhammer, G.; McCormick, S. D.

2003-01-01

79

Physiological and behavioral consequences in rats of water recycling during lactation.  

PubMed

Radioactive water injected into 10-day-old rats were recovered the following day from their mothers' blood. This transfer of water was nearly eliminated by ligating the injected pups' urethras, a result indicating that mother rats consume their offspring's urine. Preventing urine consumption by ligating urethras of all pups in a litter doubled the plasma volume deficit in dams produced by 24 hr of water deprivation alone and led to increased isotonic saline, but not water, intakes following after water deprivation. Mother rats' daily water intakes increased after they were deprived of pup urine, and their pup-licking behavior increased following water deprivation. These findings indicate that urine consumption by mother rats has both physiological and behavioral consequences and suggest that pup licking is, in part, an ingestive behavior. PMID:7217412

Friedman, M I; Bruno, J P; Alberts, J R

1981-02-01

80

Improvement of Physiological Characteristic of Selenium-Enriched Candida utilis with Amino Acids Addition  

PubMed Central

The effects of amino acids addition on cell growth, glutathione biosynthesis, glutathione distribution, and the intracellular oxidation-reduction environment of Candida utilis SZU 07-01 during selenium enrichment were investigated in this study. Most amino acids under appropriate concentrations have positive effects on cell growth of the yeast strain, except for phenylalanine and proline, compared with the control without amino acid addition. The bioconversion of selenite to organic selenium induced the reduction of glutathione synthesis and intracellular distribution of glutathione. However, amino acids including cysteine, glutamine, glutamic acid, isoleucine, leucine, and tyrosine could effectively promote the selenium-enriched yeast to elevate glutathione production, especially increasing the intracellular glutathione content. Moreover, addition of these six different amino acids apparently decreased malondialdehyde concentration and recovered the normal intracellular redox environment of the selenium-enriched C. utilis SZU 07-01. The improvement of physiological characteristic of the selenium-enriched yeast by increasing intracellular glutathione content and lowering malondialdehyde content will undoubtedly help to widen application of selenium-enriched yeast as food or feed additives.

Xiaoguang, Ge; Dahui, Wang; Gongyuan, Wei; Min, Nie; Na, Shao

2011-01-01

81

[Effects of light quality on rice seedlings growth and physiological characteristics].  

PubMed

By using light emitting diode (LED) to accurately modulate spectral energy distribution, and with fluorescent light as the control, this paper studied the effects of light quality on the seedlings growth and physiological characteristics of rice cultivars 'Wuyunjing 7' and 'Kangyou 63'. Light quality had significant effects on the seedlings growth, and there existed differences at different growth stages. Blue LED inhibited the height growth significantly, and increased the leaf soluble protein content of 'Wuyunjing 7' and the healthy index of the two rice cultivars at five-leaf stage. Red LED increased the stem diameter and healthy index at three-leaf stage and the leaf soluble sugar and starch contents at five-leaf stage significantly. Red-blue LED increased the root number, stem diameter, healthy index, root activity, and root soluble sugar content at three-leaf stage and the fresh mass, dry mass, healthy index, and leaf soluble sugar and sucrose contents at five-leaf stage significantly. Yellow LED increased the plant height and leaf pigment content at initial growth stage. Overall, red-blue LED was more beneficial to the culture of strong rice seedlings. PMID:21941749

Guo, Yin-Sheng; Gu, Ai-Su; Cui, Jin

2011-06-01

82

Cuffless and noninvasive tonometry mean arterial pressure measurement by physiological characteristics and applied pressure.  

PubMed

We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of a pulse pressure is not obtained at mean arterial pressure (MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tissue, the depth of blood vessel. Through an analysis of 198 clinic data, we have induced the regression equation of the MAP. The probability of the elasticity, depth and AP(M) to explain MAP was 92.1%. The mean difference and the standard deviation between the MAP predicted from the regression equation and the MAP measured by commercial cuff type BP meter were Z-3.183 mmHg and 5.133 mmHg respectively. Comparing the results with the American national standard for electronic or automated sphygmomanometers, we can conclude that the results are quite reliable and promising. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement technique. Our technique makes new way for the cuffless BP measurement. PMID:17946765

Park, Mikyoung; Kang, HeeJung; Huh, Young; Kim, Kyung-Chul

2006-01-01

83

Physiological characteristics of well-trained synchronized swimmers in relation to performance scores.  

PubMed

The purpose of this study was to examine the relationships between the physiological characteristics of synchronized swimmers and their performance scores. The subjects were 16 trained female synchronized swimmers with a mean age of 17.2 +/- 1.7 years (mean +/- SD). The examined variables were body dimensions (height, width, body mass, circumference of the body and segment length), body composition, isokinetic muscle strength of the elbow and knee during extension and flexion, abdominal muscle endurance, anaerobic power (leg extension power and peak blood lactate concentration), aerobic power (maximum oxygen uptake [VO2max], swimming velocity at the onset of blood lactate accumulation [OBLA-V]), and flexibility (standing trunk flexion, prone trunk extension and distance between the open legs). The performance scores had significant correlations (p < 0.05) with isokinetic muscle strength of the elbow extension and flexion, and the knee extension, abdominal muscle endurance, leg extension power, VO2max x wt(-1), OBLA-V and distance between the open legs. However, no significant correlations were found between the performance scores and anthropometric variables. This study showed that the performance scores of synchronized swimmers correlated significantly with the functional aspects, and that muscle strength, muscle endurance and aerobic capacity seem to be particularly important determinants. PMID:10376481

Yamamura, C; Zushi, S; Takata, K; Ishiko, T; Matsui, N; Kitagawa, K

1999-05-01

84

Characteristics of a Novel Water Plasma Torch  

NASA Astrophysics Data System (ADS)

Relying on heat generated by plasma arc heating liquid water into steam as a swirl gas, a water plasma torch has the distinctive steam generation structure, which has various applications such as in the treatment of organic waste and hydrogen production for fuel cells in future vehicles. The operational features of the water plasma torch and water phase change process in the discharge chamber are investigated based on the temporal evolution of the voltage and current. The optical emission spectrum measurement shows that the water molecule in the plasma is decomposed into H, OH and O radicals. As the electrodes do not require water-cooling, the thermal efficiency of the torch is very high, which is confirmed by analytical calculation and experimental measurement.

Ni, Guo-Hua; Meng, Yue-Dong; Cheng, Cheng; Lan, Yan

2010-05-01

85

Effects of 8-weeks Circuit Training Programme on Physiological and Performance Characteristics of University Racket Game Players  

Microsoft Academic Search

The attainment and sustenance of excellent performance in any sporting engagement via the adoptions of specific training method alone may be in doubt without special emphasizes on general fitness training methods. This study was carried out to examine the responses exhibited by University of Ibadan racket game athletes concerning their physiological and performance characteristics following an 8-week circuit training programme.

J. F BABALOLA

2011-01-01

86

Evaluation of structural and physiological plant characteristics in relation to the distribution of cadmium in maize inbred lines  

Microsoft Academic Search

To establish the structural and physiological characteristics related to the genotypic variation in Cd distribution between maize inbred lines (‘shoot Cd excluders’ and ‘non-shoot Cd excluders’), shoot and root morphological parameters were studied on plants grown in nutrient solution. Furthermore, the xylem sap composition and the desorbability of Cd from roots of these inbreds have been compared. No relationship between

P. J. Florijn; J. A. Nelemans; M. L. VAN BEUSICHEM

1993-01-01

87

Upper Limb Contralateral Physiological Characteristic Evaluation for Robot-Assisted Post Stroke Hemiplegic Rehabilitation  

Microsoft Academic Search

\\u000a An innovative robot-aided quantitative evaluation method was established in order to evaluate disability level of post hemiplegic\\u000a stroke patients. A sEMG-driven musculoskeletal model utilized the physiological characters of impaired limb and normalized\\u000a by healthy limbs’ physiological characters can be applied to calculate muscle strength and other dynamics data (such as elbow\\u000a joint torque). By comparing physiological characters of impaired upper

Lap-Nam Wong; Qun Xie; Linhong Ji

88

Spectral radiation characteristics of water sprays  

Microsoft Academic Search

In this paper an analysis is presented to predict the spectral absorption, extinction and scattering coefficients of water sprays using Mie theory for spherical, homogeneous particles. The spectral absorption and extinction efficiencies are calculated for different mean droplet diameters and different droplet size distributions. To generalize the results and account for the spectral dependence of the optical constants of water,

R. Viskanta; C. C. Tseng

2007-01-01

89

Static Pressure Fractionation Characteristics of Water Hyacinth.  

National Technical Information Service (NTIS)

Up to 82% of the water in water hyacinth was removed from prepared plants by multiple pressings in a screen-lined cylinder with a low speed press. Plants as wet as 2089% dry basis moisture content were pressed to as low as 404% dry basis moisture content ...

L. O. Bagnall F. J. Corral

1974-01-01

90

Water Hammer Analysis by Characteristic Method  

Microsoft Academic Search

Rapid changes in the velocity of fluid in closed conduits generate large pressure, which are transmitted through the system with the speed of sound. When the fluid medium is a liquid the pressure surges and related phenomena are described as water hammer. Water hammer is caused by normal operation of the system, such as valve opening or closure, pump starts

A. R. Lohrasbi

91

Physiological characteristics of elite and club level female triathletes during running.  

PubMed

Most studies of the triathlon have looked at male triathletes with respect to the longer distance events such as the Hawaii Ironman Triathlon. The purpose of this study was to investigate and compare the physiological characteristics and training protocols of elite and competitive (club) women triathletes who compete at Olympic distance (1.5 km swim, 40 km cycle, 10 km run) to examine the relationship between these factors and running performance in the triathlon. The elite triathletes (n = 10) had a lower body mass and BMI than club level triathletes (n = 9) as well as smaller girths at all measured sites although these differences were not significant. Sum of skinfold thickness measured at four sites was significantly smaller in the elite group (p = 0.05), yet, wide individual variations were found within each group. The amount of training undertaken by individuals in both groups varied markedly; however, overall the elite did more training in all disciplines. The VO2max measured on the treadmill was significantly higher (p = 0.03) in the elite women (65.6 +/- 6.0 ml.kg-1.min-1) as compared to the club level women (60.4 +/- 3.1 ml.kg-1.min-1). The elite triathletes were significantly more economical, showing a lowered relative oxygen consumption (% VO2max), (p = 0.008); lowered heart rate (p = 0.01) and lowered blood lactate values (p = 0.03) at 15 km.h-1. The elite group were also much more efficient runners at 15 km.h-1 when looking at VE/VO2 (p = 0.05). An association was found between run race time and %VO2max at 15 km.h-1 (p = 0.04). The results suggest that there is no ideal nor unique anthropometric profile that can be established for female triathletes especially with respect to running time and overall performance. The widespread differences in physiological variables found between the two groups confirms the important contribution factors such as these make to performance. PMID:8300272

Laurenson, N M; Fulcher, K Y; Korkia, P

1993-11-01

92

The Relation of Psychopathic Characteristics and Anxiety in Noncriminals: Physiological and Cognitive Responses to Guided Imagery  

Microsoft Academic Search

In response to a paucity of research examining the phenomenology of psychopathy among nonforensic samples, the present study explored the relations among psychopathic traits, self-reported anxiety, and physiological reactivity to experimental stimuli. Undergraduate students with no history of criminal behavior listened to four audiotaped vignettes designed to elicit affective responses. Imagery and anxiety ratings, as well as physiological indices supported

Robert L. Bare; Derek R. Hopko; Maria E. A. Armento

2004-01-01

93

Atomization characteristics of coal-water mixtures  

SciTech Connect

There is very little published information on the atomization of coal-water fuels where the presence of solid particles with their own size distribution is expected to affect the process of liquid breakup. This paper presents results obtained on the air atomization of coal-water fuels. A standard air atomizer was used in the experiments. A Malvern particle sizer was used to acquire the drop size distribution. The drop size was measured as a function of the key atomizer parameters, namely, the air pressure and the ratio of fuel and atomizing air mass flow rates. Measurements were made using water to give the baseline and a coal-water mixture with 33 percent of weight coal. Some of the important conclusions are: (1) At similar atomizing conditions (that is, same air pressure and fuel to air mass flow ratio), the mass median diameter for the coal-water mixture was consistently less than that for the water. (2) The difference noted above decreased for low fuel/air mass flow; that is, when the mean diameter became small. (3) The size distribution in both cases seemed to fit well a Rosin-Rammler distribution (within the accuracy of measurement).

Krishna, C.R.; Marnell, P.; Butcher, T.A.

1982-01-01

94

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

PubMed

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

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

2008-01-01

95

Divergent physiological characteristics and responses to endurance training among inbred mouse strains.  

PubMed

Both baseline values and adaptive changes in mice can vary depending on the genetic background. We aimed to assess variation in a battery of variables and their adaptations to endurance training in six inbred mouse strains. Males, n?=?184, from A/J, BALB/cByJ, C3H/HeJ, C57BL/6J, DBA/2J, and PWD/PhJ strains were assigned to a control or an endurance group (5 weeks swimming exercise). Enzyme activity, histology of soleus (SOL) muscle, swimming endurance, cardiac ventricular and hind limb muscle weight, and femur length were examined. Endurance capacity, morphological and histological variables, and enzyme activity substantially differed among strains. For example, SOL weight was twofold higher and cross-sectional area (CSA) of fibers was ?30% greater in C57BL/6J than in PWD/PhJ strain. The CSA of type 1 fibers were larger than type 2A in PWD/PhJ (P?physiological characteristics and adaptations to training in mice. PMID:22414113

Kilikevicius, A; Venckunas, T; Zelniene, R; Carroll, A M; Lionikaite, S; Ratkevicius, A; Lionikas, A

2012-03-13

96

Physiological characteristics of the best Eritrean runners-exceptional running economy.  

PubMed

Despite their young age, limited training history, and lack of running tradition compared with other East African endurance athletes (e.g., Kenyans and Ethiopians), male endurance runners from Eritrea have recently attained important running successes. The purposes of our study were (i) to document the main physical and physiological characteristics of elite black Eritrean distance runners (n = 7; age: 22 +/- 3 years) and (ii) to compare them with those of their elite white Spanish counterparts. For this second purpose we selected a control group of elite Spanish runners (n = 9; 24 +/- 2 years), owing to the traditionally high success of Spanish athletes in long-distance running compared with other white runners, especially in cross-country competitions. The subjects' main anthropometric characteristics were determined, together with their maximum oxygen uptake (VO2 max) and VO2 (mL.kg(-1).min(-1)), blood lactate, and ammonia concentrations while running at 17, 19, or 21 km.h(-1). The body mass index (18.9 +/- 1.5 kg.m(-2)) and maximal calf circumference (30.9 +/- 1.5 cm) was lower in Eritreans than in Spaniards (20.5 +/- 1.7 kg.m(-2) and 33.9 +/- 2.0 cm, respectively) (p < 0.05 and p < 0.01, respectively) and their lower leg (shank) length was longer (44.1 +/- 3.0 cm vs. 40.6 +/- 2.7 cm, respectively) (p < 0.05). VO2 max did not differ significantly between Eritreans and Spaniards (73.8 +/- 5.6 mL.kg(-1).min(-1) vs. 77.8 +/- 5.7 mL.kg(-1).min(-1), respectively), whereas the VO2 cost of running was lower (p < 0.01) in the former (e.g., 65.9 +/- 6.8 mL.kg(-1).min(-1) vs. 74.8 +/- 5.0 mL.kg(-1).min(-1) when running at 21 km.h(-1)). Our data suggest that the excellent running economy of Eritreans is associated, at least partly, with anthropometric variables. Comparison of their submaximal running cost with other published data suggests that superior running economy, rather than enhanced aerobic capacity, may be the common denominator in the success of black endurance runners of East African origin. PMID:17111007

Lucia, Alejandro; Esteve-Lanao, Jonathan; Oliván, Jesús; Gómez-Gallego, Félix; San Juan, Alejandro F; Santiago, Catalina; Pérez, Margarita; Chamorro-Viña, Carolina; Foster, Carl

2006-10-01

97

Physiological modelling of the response of Kocuria rosea exposed to changing water activity  

Microsoft Academic Search

Physiological effects of NaCl concentration (equivalent water activities, aw, 1 to 0.87) were investigated with the moderately halophilic and piezotolerant bacterium, Kocuria rosea (formerly Micrococcus roseus), grown in bacteriological peptone\\/yeast extract broth. This bacterium, which was isolated from open shallow seawater, can grow in 150 g NaCl l-1 (optimum NaCl concentration: 30 g l-1, aw=0.984) and under 207 MPa of hydrostatic pressure. The effects of

Phillip C. Wright; Tsuyoshi Tanaka

2002-01-01

98

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

Microsoft Academic Search

The current study examines the use of hand immersion in cold water to alleviate physiological strain caused by exercising\\u000a in a hot climate while wearing NBC protective garments. Seventeen heat acclimated subjects wearing a semi-permeable NBC protective\\u000a garment and a light bulletproof vest were exposed to a 125 min exercise–heat stress (35°C, 50% RH; 5 km\\/h, 5% incline). The\\u000a heat stress exposure

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

2008-01-01

99

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

PubMed Central

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

Katsaras, J

1997-01-01

100

Evaluation of Hydrogel Application on Soil Water Retention Characteristics  

Microsoft Academic Search

Hydrogels can absorb irrigation and rain water and help to reduce deep percolation by using gravitational water as well as capillary water. The objective of this study was to evaluate the effect of hydrogels on soil water retention characteristic curve (WRC) using RETC computer model. The hydrogels, PR3005A and Tarawat A100 in four levels, 2, 4, 6, and 8 g\\/kg,

Jahangir Abedi-Koupai; Farahnaz Sohrab; Gareth Swarbrick

2008-01-01

101

Safety handling characteristics of high-level tritiated water  

Microsoft Academic Search

In a fusion reactor, high-level tritiated water of more than one PBq\\/m3 will be generated and stored in various areas. The high-level tritiated water decomposes by itself and generates mainly hydrogen, becoming tritiated hydrogen peroxide water. In order to summarize safety requirements for long-term storage of high-level tritiated water, the characteristics, such as effective G-values of hydrogen and hydrogen peroxide,

T. Hayashi; T. Itoh; K. Kobayashi; K. Isobe; M. Nishi

2006-01-01

102

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

PubMed

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

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

2012-12-23

103

Genome duplication and the evolution of physiological responses to water stress.  

PubMed

Whole-genome multiplication, or polyploidy, is common in angiosperms and many species consist of multiple cytotypes that have different physiological tolerances. However, the relative importance of genome duplication vs post-duplication evolutionary change in causing differentiation between cytotypes is not known. We examined the water relations of Chamerion angustifolium, a herbaceous perennial in which diploid and tetraploid cytotypes occupy different niches. To differentiate between the effects of genome duplication and evolutionary changes that followed polyploidization, we compared extant diploids and tetraploids with experimentally synthesized neotetraploids. Tetraploids had 32% higher xylem hydraulic conductivity (K(H)) than neotetraploids and 87% higher K(H) than diploids, but vulnerability to water stress induced cavitation and gas exchange sensitivity to water potential did not differ among cytotypes. Nevertheless, tetraploids took 22% and 30% longer to wilt than neotetraploids and diploids. A simple hydraulic model suggested that tetraploids deplete soil moisture to a greater degree than neotetraploids and diploids before reaching leaf water potentials that cause stomatal closure. We conclude that the different physiological tolerances and distribution of diploid and tetraploid C. angustifolium are unlikely to be caused solely by genome duplication. The enhanced ability of tetraploids to survive water stress likely evolved after polyploidization. PMID:19703115

Maherali, Hafiz; Walden, Alison E; Husband, Brian C

2009-08-24

104

Water Vapor Influence on Satellite-Measured Aerosol Characteristics.  

National Technical Information Service (NTIS)

This study demonstrates the significance of water vapor's influence on satellite retrieved aerosol characteristics using NOAA's AVHRR. An improvement to optical depth and Aerosol Particle Size Index (S12) estimations derived from channels 1 (0.63 microns ...

T. P. Mahony

1991-01-01

105

Comparative Characteristics of Internal Physiological Changes in Man during Adaptation to Alpine and Desert Conditions.  

National Technical Information Service (NTIS)

A comparative study of physiological shifts in people when changing their residence showed that the adaptation to mountain as well as desert conditions proceeds in 'northerners' at a slower rate than in 'southerners'. Indices of the cardiovascular system,...

M. F. Avazbakieva

1976-01-01

106

Interactions of water stress and solar irradiance on the physiology and biochemistry of Ligustrum vulgare.  

PubMed

We studied the interactive effects of water stress and solar irradiance on physiological and biochemical traits in Ligustrum vulgare L., with special emphasis on antioxidant enzymes and flavonoids. Water relations, photosynthetic performance, plant growth, activities of antioxidant enzymes and of phenylalanine-ammonia-lyase, and concentrations of nonstructural carbohydrates and phenylpropanoids were measured in plants growing in 12% (shade) or 100% (sun) sunlight and supplied with 100 or 40% of daily evapotranspiration-demand over a 4-week period. The mild water stress treatment caused leaf water potential and relative water content to decline on average by -0.22 MPa and 4.5%, respectively. In response to the water stress treatment, photosynthetic rates decreased more in sun plants than in shade plants, likely because of declines in photosystem II photochemistry, apparent maximum rate of carboxylation and apparent maximum electron transport rate coupled with significant reductions in stomatal conductance. Antioxidant enzymatic activities, which were much greater in sun leaves than in shade leaves under well-watered conditions, increased (particularly the enzymatic activities associated with hydrogen peroxide removal) in response to water stress only in shade leaves. Antioxidant phenylpropanoids, particularly quercetin and luteolin derivatives, markedly increased in response to full sunlight irrespective of water treatment; however, antioxidant phenylpropanoid concentrations increased in response to water stress only in shade leaves. We suggest that: (1) assimilated carbon in sun plants was used largely to support an effective antioxidant system capable of countering water-stress-induced oxidative damage--an example of cross tolerance; and (2) in shade plants, carbon was also diverted from growth to counter oxidative damage driven by the mild water-stress treatment. Both findings are consistent with the nearly exclusive distribution of L. vulgare in well-watered, partially shaded Mediterranean areas. PMID:18381268

Guidi, L; Degl'Innocenti, E; Remorini, D; Massai, R; Tattini, M

2008-06-01

107

Influences affecting the soil-water characteristic curve  

Microsoft Academic Search

The soil-water characteristic curve (SWCC) is the primary partially saturated soil information as its behavior and properties can be derived from it. Although there have been many studies of unsaturated soils and the SWCC, there is still no combined constitutive model that can simulate soil characteristics accurately. In cases when hydraulic hysteresis is dominant (e.g. under cyclic loading) it is

ZHOU Jian; YU Jian-lin

2005-01-01

108

Water chemistry and its effects on the physiology and survival of Atlantic salmon Salmo salar smolts.  

PubMed

The physiological effects of episodic pH fluctuations on Atlantic salmon Salmo salar smolts in eastern Maine, U.S.A., were investigated. During this study, S. salar smolts were exposed to ambient stream-water chemistry conditions at nine sites in four catchments for 3 and 6 day intervals during the spring S. salar smolt migration period. Plasma chloride, plasma glucose, gill aluminium and gill Na(+)- and K(+)-ATPase levels in S. salar smolts were assessed in relation to ambient stream-water chemistry during this migration period. Changes in both plasma chloride and plasma glucose levels of S. salar smolts were strongly correlated with stream pH, and S. salar smolt mortality occurred in one study site with ambient stream pH between 5·6 and 5·8 during the study period. The findings from this study suggest that physiological effects on S. salar smolts are strongly correlated with stream pH and that in rivers and streams with low dissolved organic carbon (DOC) concentrations the threshold for physiological effects and mortality probably occurs at a higher pH and shorter exposure period than in rivers with higher DOC. Additionally, whenever an acidification event in which pH drops below 5·9 coincides with S. salar smolt migration in eastern Maine rivers, there is potential for a significant reduction in plasma ions of S. salar smolts. PMID:21781105

Liebich, T; McCormick, S D; Kircheis, D; Johnson, K; Regal, R; Hrabik, T

2011-08-01

109

Physiological Characteristics and Leaf Ultrastructure of a Novel Chlorophyll-deficient chd6 Mutant of Vitis venifera Cultured in vitro  

Microsoft Academic Search

A novel chlorophyll-deficient chd6 mutant of F1 hybrids from Vitis venifera was selected to study its primarily physiological characteristics and leaf ultrastructures under culturing in vitro. The\\u000a results showed that although increasing Fe2+ and Mg2+ concentration could improve growth of the mutant in vitro, the effect was limited. In addition, it was determined that relatively\\u000a lower Fe2+ and Mg2+ concentrations

Delong Yang; Sheng Li; Mengfei Li; Xiuling Yang; Wangtian Wang; Ziyi Cao; Wei Li

110

Alternative electron flows (water-water cycle and cyclic electron flow around PSI) in photosynthesis: molecular mechanisms and physiological functions.  

PubMed

An electron flow in addition to the major electron sinks in C(3) plants [both photosynthetic carbon reduction (PCR) and photorespiratory carbon oxidation (PCO) cycles] is termed an alternative electron flow (AEF) and functions in the chloroplasts of leaves. The water-water cycle (WWC; Mehler-ascorbate peroxidase pathway) and cyclic electron flow around PSI (CEF-PSI) have been studied as the main AEFs in chloroplasts and are proposed to play a physiologically important role in both the regulation of photosynthesis and the alleviation of photoinhibition. In the present review, I discuss the molecular mechanisms of both AEFs and their functions in vivo. To determine their physiological function, accurate measurement of the electron flux of AEFs in vivo are required. Methods to assay electron flux in CEF-PSI have been developed recently and their problematic points are discussed. The common physiological function of both the WWC and CEF-PSI is the supply of ATP to drive net CO(2) assimilation. The requirement for ATP depends on the activities of both PCR and PCO cycles, and changes in both WWC and CEF-PSI were compared with the data obtained in intact leaves. Furthermore, the fact that CEF-PSI cannot function independently has been demonstrated. I propose a model for the regulation of CEF-PSI by WWC, in which WWC is indispensable as an electron sink for the expression of CEF-PSI activity. PMID:21068108

Miyake, Chikahiro

2010-11-10

111

Physiological relationships of the early posthatch performance of broilers to their embryo and eggshell characteristics.  

PubMed

Relationships between physiological parameters of early posthatch chicks with their corresponding egg and embryo parameters were examined in progeny of young broiler breeders. Four hundred and 80 broiler hatching eggs that were obtained from a 29-wk-old Ross 308 breeder flock were incubated on 8 replicate tray levels of an incubator until hatch. Between 10.5 and 18.5 d of incubation, internal (T(emb)) and external (T(ext)) egg temperatures were recorded twice daily using temperature transponders. Beginning at 18.5 d, the eggs were individually monitored for hatch every 12 h. Average T(emb), T(ext), and average daily incubational egg weight loss (EWL) for the 10.5- to 18.5-d incubation period were used to calculate eggshell water vapor conductance (G(H2O)), specific G(H2O) (g(H2O); G(H2O) adjusted to 100 g of set egg weight basis), and a G(H2O) constant (K(H2O)) for each egg. Chicks were grown out for 10 d in pens of a single battery brooder. In each pen, on d 3 posthatch, carcasses, yolk sac, liver, and pipping muscle samples were collected from at least 2 chicks that hatched from eggs implanted with transponders for determination of their relative weights and moisture concentrations. Livers and pipping muscles were also analyzed for glucose, glycogen, fat, and protein concentrations. Yolk sac weight as a percentage of chick BW (YW) and its moisture concentration (YSM) were positively correlated with T(emb). Egg g(H2O) was positively correlated with chick carcass moisture concentration and its relative weight as a percentage of set egg weight, but it was negatively correlated with YW. The positive functional relationship between T(emb) and incubation length may be mediated via their common positive relationships to YSM. A negative correlation was observed between percentage EWL and relative BW on d 0 and 0.5 posthatch for chicks hatched from unimplanted eggs. The results suggest that a higher g(H2O) results in an increased metabolism of the broiler embryo, which subsequently increases growth and yolk sac absorption in broiler chicks through 3 d posthatch. PMID:22700498

Pulikanti, R; Peebles, E D; Zhai, W; Bennett, L W; Gerard, P D

2012-07-01

112

Melting characteristics of horizontal ice surfaces in cold saline water  

Microsoft Academic Search

The results of an experimental investigation of the buoyancy driven flow adjacent to and below a horizontal ice surface melting in cold water at near oceanic salinity are presented. This melting configuration is characteristic of circumistances encountered by sea ice, for example, by new ice and, also, on the bottom of tabular ice floes. Several ambient water temperatures t, are

Benjamin Gebhart; Bahgat Sammakia; Tore Audunson

1983-01-01

113

Physiological characteristics of cassava tolerance to prolonged drought in the tropics: implications for breeding cultivars adapted to seasonally dry and semiarid environments  

Microsoft Academic Search

The paper summarizes research conducted at International Center for Tropical Agriculture (CIAT) on responses of cassava to extended water shortages in the field aided by modern gas-exchange and water-relation techniques as well as biochemical assays. The aim of the research was to coordinate basic and applied aspects of crop physiology into a breeding strategy with a multidisciplinary approach. Several physiological

Mabrouk A. El-Sharkawy

2007-01-01

114

Regulatory and autoregulatory physiological dysfunction as a primary characteristic of post concussion syndrome: implications for treatment.  

PubMed

Although most patients with concussion recover within days to weeks, a small but significant minority develop persistent signs and symptoms of post-concussion syndrome (PCS). The standard treatments of PCS, rest and cognitive adaptation, have limited effectiveness. PCS patients are advised not to exercise because of the concern for symptom exacerbation. Prolonged rest, however, leads to deconditioning (especially in athletes) and may cause secondary effects including depressive symptoms. Concussion is associated with metabolic and physiological changes in the brain and in other organ systems (for example, autonomic function of the heart and altered cerebral autoregulation, sleep, and circadian rhythms). We propose that PCS results from ongoing central and systemic physiologic regulatory dysfunction after traumatic brain injury (TBI) and we further propose that this physiologic dysfunction may be reduced or alleviated by individualized controlled sub-symptom threshold aerobic exercise rehabilitation. PMID:17917170

Leddy, John J; Kozlowski, Karl; Fung, Michael; Pendergast, David R; Willer, Barry

2007-01-01

115

Comparative morpho-physiological and biochemical responses of lentil and grass pea genotypes under water stress  

PubMed Central

Background: Both lentil (Lens culinaris Medik.) and grass pea (Lathyrus sativus L.) in the family Fabaceae are two important cool-season food legumes, often experiencing water stress conditions during growth and maturity. Objective: The present study was undertaken to ascertain the response of these two crops under different water stress regimes. Materials and Methods: Different morpho-physiological and biochemical parameters were studied in a pot experiment under controlled environmental conditions. Along with control (proper irrigation, 0 stress), three sets of plants were subjected to mild (6 d), moderate (13 d) and severe (20 d) water stress by withholding irrigation at the appropriate time. Results: Compared with control, plant growth traits and seed yield components reduced significantly in both crops with increasing period of water stress, resulting in lowering of dry mass with more severe effect on lentil compared with grass pea. Foliar Relative Water Content (RWC) (%), K+/Na+ ratio, chlorophyll (chl) a, chl a/b ratio, stomatal conductance and net photosynthetic rate declined considerably in both crops under water stress. Leaf-free proline level increased significantly in both crops, but it decreased markedly in nodules of lentil and remained unchanged in grass pea. Nodulation was also affected due to water stress. The impairment in growth traits and physio-biochemical parameters under water stress was manifested in reduction of drought tolerance efficiency of both crops. Conclusion: Impact of water stress was more severe on lentil compared with grass pea, and modulation of growth traits signified necessity of a detailed strategy in breeding of food legumes under water stress.

Talukdar, Dibyendu

2013-01-01

116

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

Code of Federal Regulations, 2013 CFR

...characteristics, control, and stability on water. 25.239 Section 25.239 Aeronautics...CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.239...characteristics, control, and stability on water. (a) For seaplanes and...

2013-01-01

117

Spray Characteristics Determination of Water Mist for Suppressing Pool Fire  

NASA Astrophysics Data System (ADS)

To optimize the design of a water mist fire suppression system or to provide input data and validation data for field models, the characteristics of the water mist field are needed. This data typically consists of the distribution of droplet sizes and velocities. In this research a LS2000 Laser Sizer has been proposed to simultaneously determine spray characteristics of 408 kinds of self-developed nozzles for fire suppression. The results of LS2000 Laser Sizer measurements to characterize the water mist produced by nozzles for suppressing pool fire are presented. These data can provide a foundation to the design and optimization of additive-containing WMFSS. To explore the effect of the water pressure on the droplet size distribution and spray velocity, data from three typical pressures of 0.9MPa, 1.2MPa and 1.5MPa have been obtained. With the measured average size and distribution of droplets, a comparison between three nozzles was made in the pressure of 1.5MPa to investigate the influence of the nozzle design parameters on atomizing characteristics. The results show that representative size of droplets decreases slightly and the water flow rate increases with the water pressure to the nozzle head Pw, and the droplet velocity of water mist is approximately directly proportional to Pw. The trends that the nozzles with the larger D32 have a wider range of droplet diameter distribution and their volume fraction curves shift towards the large diameter direction are also found in measurements. This will be favorable to the extinguishment of kerosene pool fire. The water flux density distribution results demonstrated that the water flux density over the cross section was very non-uniform when the water mist nozzle is improperly designed.

Zheng, Li G.; Yu, Ming G.; Yu, Shui J.; Liu, Zhi C.

2007-06-01

118

Water films and scaling of soil characteristic curves at low water contents  

Microsoft Academic Search

Individual contributions of capillarity and adsorptive surface forces to the matric potential are seldom differentiated in determination of soil water characteristic (SWC) curves. Typically, capillary forces dominate at the wet end, whereas adsorptive surface forces dominate at the dry end of a SWC where water is held as thin liquid films. The amount of adsorbed soil water is intimately linked

Markus Tuller

2005-01-01

119

Soil Water Characteristic Determination from Concurrent Water Content Measurements in Reference Porous Media  

Microsoft Academic Search

tant in many water flow processes. Common approaches to measuring (h) in intact field soils require paired We introduce and verify the use of calibrated reference soils or and h sensors; however, most paired-sensor methods other porous media having known and reproducible water retention characteristics as a means to determine the unknown water retention suffer from incompatibility in measurement range

Jon M. Wraith; Dani

2001-01-01

120

Photodegradation characteristics of PPCPs in water with UV treatment  

Microsoft Academic Search

The degradation characteristics of PPCPs commonly found in surface water under UV treatment were examined for 30 kinds of PPCPs using a UV\\/Lamp1 that emits light at a wavelength of 254 nm and a UV\\/Lamp2 that emits light at 254 nm and 185 nm in pure water. When a UV dose of some 230 mJ\\/cm2 was introduced to the 30 PPCPs, photodegradation rates of

Ilho Kim; Hiroaki Tanaka

2009-01-01

121

Atomization characteristics of coal-water slurry. Final report  

Microsoft Academic Search

Dwindling supplies of oil have led to increasing interest in alternative fuels which can be used to replace petroleum-derived liquid fuels. One such fuel is coal-water slurry. This study presents the atomization behavior of coal-water slurries at conditions typical of a gas turbine combustor. Slurry spray characteristics were determined using five different types of atomizer. The five nozzle types included

A. H. Lefebvre; P. E. Sojka

1986-01-01

122

He-Ne laser-induced improvement in biochemical, physiological, growth and yield characteristics in sunflower (Helianthus annuus L.).  

PubMed

The water-soaked seeds of sunflower were exposed to low power continuous wave He-Ne laser irradiation of energies 0, 100, 300 and 500 mJ to evaluate the effect on various biochemical, physiological, growth and yield parameters of sunflower. The experiments which consisted of four replicates arranged in a completely randomized design (CRD) were carried out under the greenhouse conditions. The physiological attributes like, photosynthetic rate (A), transpiration rate (E), intrinsic CO(2) concentration (C(i) ), stomatal conductance (g(s)), chlorophyll a and b contents, relative membrane permeability and leaf water (?(w)), osmotic (?(s)) and turgor (?(p)) potentials, relative water contents and leaf area increased significantly as compared to control due to He-Ne treatment of seeds. The activities of superoxide dismutase, peroxidase and catalases and contents of total soluble proteins, malondialdehyde, proline and leaf total phenolic also increased due to laser treatment. Significant increase in growth parameters of sunflower like shoot fresh and dry masses, root fresh and dry masses, root and shoot lengths, number of leaves per plant and stem diameter has also been observed. The contents of K, Ca and Mg in shoot and root were also increased and an overall increase of up to 28.12% was observed due to laser treatment. PMID:21790619

Perveen, Rashida; Jamil, Yasir; Ashraf, Muhammad; Ali, Qasim; Iqbal, Munawar; Ahmad, Muhammad Raza

2011-08-31

123

Morpho-physiological Characteristics of Dorsal Subicular Network in Mice after Pilocarpine Induced Status Epilepticus  

PubMed Central

The goal of this study was to examine morpho-physiological changes in the dorsal subiculum network in the mouse model of temporal lobe epilepsy using extracellular recording, juxtacellular and immunofluorescence double labeling, and anterograde tracing methods. A significant loss of total dorsal subicular neurons, particularly calbindin, parvalbumin (PV), and immunopositive interneurons, was found at 2 months after pilocarpine-induced status epilepticus (SE). However, the sprouting of axons from lateral entorhinal cortex (LEnt) was observed to contact with surviving subicular neurons. These neurons had two predominant discharge patterns: bursting and fast irregular discharges. The bursting neurons were mainly pyramidal cells, and their dendritic spine density and bursting discharge rates were increased significantly in SE mice compared to the control group. Fast irregular discharge neurons were PV-immunopositive interneurons, and had less dendritic spines in SE mice when compared to control mice. When LEnt was stimulated, bursting and fast irregular discharge neurons had much shorter latency and stronger excitatory response in SE mice compared to the control group. Our results illustrate that morpho-physiological changes in the dorsal subiculum could be part of a multilevel pathological network that occurs simultaneously in many brain areas to contribute to the generation of epileptiform activity.

He, De Fu; Ma, Dong Liang; Tang, Yong Cheng; Engel, Jerome; Bragin, Anatol; Tang, Feng Ru

2010-01-01

124

Physiological response of wild dugongs (Dugong dugon) to out-of-water sampling for health assessment  

USGS Publications Warehouse

The dugong (Dugong dugon) is a vulnerable marine mammal with large populations living in urban Queensland waters. A mark-recapture program for wild dugongs has been ongoing in southern Queensland since 2001. This program has involved capture and in-water sampling of more than 700 dugongs where animals have been held at the water surface for 5 min to be gene-tagged, measured, and biopsied. In 2008, this program expanded to examine more comprehensively body condition, reproductive status, and the health of wild dugongs in Moreton Bay. Using Sea World's research vessel, captured dugongs were lifted onto a boat and sampled out-of-water to obtain accurate body weights and morphometrics, collect blood and urine samples for baseline health parameters and hormone profiles, and ultrasound females for pregnancy status. In all, 30 dugongs, including two pregnant females, were sampled over 10 d and restrained on deck for up to 55 min each while biological data were collected. Each of the dugongs had their basic temperature-heart rate-respiration (THR) monitored throughout their period of handling, following protocols developed for the West Indian manatee (Trichechus manatus). This paper reports on the physiological response of captured dugongs during this out-of-water operation as indicated by their vital signs and the suitability of the manatee monitoring protocols to this related sirenian species. A recommendation is made that the range of vital signs of these wild dugongs be used as benchmark criteria of normal parameters for other studies that intend to sample dugongs out-of-water.

Lanyon, Janet M.; Sneath, Helen L.; Long, Trevor; Bonde, Robert K.

2010-01-01

125

First evidence for zooplankton feeding sustaining key physiological processes in a scleractinian cold-water coral.  

PubMed

Scleractinian cold-water corals (CWC) represent key taxa controlling deep-sea reef ecosystem functioning by providing structurally complex habitats to a high associated biodiversity, and by fuelling biogeochemical cycles via the release of organic matter. Nevertheless, our current knowledge on basic CWC properties, such as feeding ecology and key physiological processes (i.e. respiration, calcification and organic matter release), is still very limited. Here, we show evidence for the trophic significance of zooplankton, essentially sustaining levels of the investigated key physiological processes in the cosmopolitan CWC Desmophyllum dianthus (Esper 1794). Our results from laboratory studies reveal that withdrawal (for up to 3 weeks) of zooplankton food (i.e. Artemia salina) caused a significant decline in respiration (51%) and calcification (69%) rates compared with zooplankton-fed specimens. Likewise, organic matter release, in terms of total organic carbon (TOC), decreased significantly and eventually indicated TOC net uptake after prolonged zooplankton exclusion. In fed corals, zooplankton provided 1.6 times the daily metabolic C demand, while TOC release represented 7% of zooplankton-derived organic C. These findings highlight zooplankton as a nutritional source for D. dianthus, importantly sustaining respiratory metabolism, growth and organic matter release, with further implications for the role of CWC as deep-sea reef ecosystem engineers. PMID:21993785

Naumann, Malik S; Orejas, Covadonga; Wild, Christian; Ferrier-Pagès, Christine

2011-11-01

126

Associations of miRNA polymorphisms and female physiological characteristics with breast cancer risk in Chinese population.  

PubMed

mircoRNAs (miRNAs) play important roles on regulation of gene expressions. Aberrant expression of miRNAs was involved in various biological and pathological processes, including tumorigenesis of breast cancer. Single-nucleotide polymorphisms (SNPs) were implicated in altered expression or biological functions of mature miRNAs. To explore the relevance of miRNA polymorphisms and female physiological characteristics to breast cancer risk, SNPs located within hsa-miR-605 (rs2043556), hsa-miR-149 (rs2292832), hsa-miR-27a (rs895819), hsa-miR-196a-2 (rs11614913) and hsa-miR-618 (rs2682818) were selected, and their associations with breast cancer risk were analysed. In addition, associations between physiological characteristics-related factors and breast cancer risk were estimated too. We found that the ones with menarche age less than 16 years had increased breast cancer risk (OR = 2.10, 95% CI: 1.23-3.60). Marginally significant association between rs11614913 CT/CC genotypes and reduced breast cancer risk was observed (OR = 0.65, 95% CI: 0.40-1.06), while no significance was detected about the other miRNA polymorphisms. We concluded that menarche at less than 16 years old increased breast cancer risk, while the genetic variants in miR-196-a-2 might decrease the risk. PMID:22074121

Zhang, M; Jin, M; Yu, Y; Zhang, S; Wu, Y; Liu, H; Liu, H; Chen, B; Li, Q; Ma, X; Chen, K

2011-11-11

127

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

SciTech Connect

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.

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

1982-01-01

128

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

PubMed Central

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.

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

2012-01-01

129

SOIL WATER CHARACTERISTIC ESTIMATES BY TEXTURE AND ORGANIC MATTER FOR HYDROLOGIC SOLUTIONS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hydrologic analyses often involve the evaluation of soil water infiltration, conductivity, storage, and plant-water relationships. To define the variable soil water effects requires estimating soil water relationships for water potential and hydraulic conductivity which depend on soil characteristic...

130

Bioaccumulation and Subchronic Physiological Effects of Waterborne Iron Overload on Whitefish Exposed in Humic and Nonhumic Water  

Microsoft Academic Search

.   One-year-old whitefish, Coregonus lavaretus, were exposed to three types of iron-rich water, two dilutions for each, in a subchronic (30-day) experiment. In natural iron-rich\\u000a humic water, both the bioaccumulation and physiological effects of iron exposure were negligible. In humic-free water with\\u000a high amount of additional inorganic iron (nominally 8 mg Fe\\/L), Fe accumulated in gills, liver, and gut. This

J. Lappivaara; A. Kiviniemi; A. Oikari

1999-01-01

131

Changes in the Microflora and Physiological - Biochemical Characteristics in the Culture of EM  

Microsoft Academic Search

Microflora of EM1 culture is converted from aerobic and neutral to anaerobic and acidic. Biochemical characteristics of EM1 changed according to change of microflora. pH, EC and content of organic acid of EM1 at the end of culture were 3 - 3.5, 0.6 - 0.9 s\\/m and 1.9 - 2.1 %, respectively. Antioxidation activity of EM1 increased in proportion to

C. M. Oh; S. B. Choi

132

Cellular composition and physiological characteristics of the diatom Thalassiosira weissflogii adapted to cadmium stress  

Microsoft Academic Search

Prolonged exposure of Thalassiosira weissflogii (Grunow) to a sub-lethal concentration of cadmium in continuous culture resulted in the development of cellular characteristics allowing optimal growth in the presence of Cd. Examination of Cd-adapted and unadapted cells was made on steady-state populations growing at the same rate in order to eliminate any effects of differing growth rate on metabolism. Adaptation to

W. K. W. Li

1979-01-01

133

Performance Characteristics of a New Generation Pressure Microsensor for Physiologic Applications  

PubMed Central

A next generation fiber-optic microsensor based on the extrinsic Fabry–Perot interferometric (EFPI) technique has been developed for pressure measurements. The basic physics governing the operation of these sensors makes them relatively tolerant or immune to the effects of high-temperature, high-EMI, and highly-corrosive environments. This pressure microsensor represents a significant improvement in size and performance over previous generation sensors. To achieve the desired overall size and sensitivity, numerical modeling of diaphragm deflection was incorporated in the design, with the desired dimensions and calculated material properties. With an outer diameter of approximately 250 µm, a dynamic operating range of over 250 mmHg, and a sampling frequency of 960 Hz, this sensor is ideal for the minimally invasive measurement of physiologic pressures and incorporation in catheter-based instrumentation. Nine individual sensors were calibrated and characterized by comparing the output to a U.S. National Institute of Standards and Technology (NIST) Traceable reference pressure over the range of 0–250 mmHg. The microsensor performance demonstrated accuracy of better than 2% full-scale output, and repeatability, and hysteresis of better than 1% full-scale output. Additionally, fatigue effects on five additional sensors were 0.25% full-scale output after over 10,000 pressure cycles.

Cottler, Patrick S.; Karpen, Whitney R.; Morrow, Duane A.; Kaufman, Kenton R.

2009-01-01

134

Performance characteristics of a new generation pressure microsensor for physiologic applications.  

PubMed

A next generation fiber-optic microsensor based on the extrinsic Fabry-Perot interferometric (EFPI) technique has been developed for pressure measurements. The basic physics governing the operation of these sensors makes them relatively tolerant or immune to the effects of high-temperature, high-EMI, and highly-corrosive environments. This pressure microsensor represents a significant improvement in size and performance over previous generation sensors. To achieve the desired overall size and sensitivity, numerical modeling of diaphragm deflection was incorporated in the design, with the desired dimensions and calculated material properties. With an outer diameter of approximately 250 microm, a dynamic operating range of over 250 mmHg, and a sampling frequency of 960 Hz, this sensor is ideal for the minimally invasive measurement of physiologic pressures and incorporation in catheter-based instrumentation. Nine individual sensors were calibrated and characterized by comparing the output to a U.S. National Institute of Standards and Technology (NIST) Traceable reference pressure over the range of 0-250 mmHg. The microsensor performance demonstrated accuracy of better than 2% full-scale output, and repeatability, and hysteresis of better than 1% full-scale output. Additionally, fatigue effects on five additional sensors were 0.25% full-scale output after over 10,000 pressure cycles. PMID:19495983

Cottler, Patrick S; Karpen, Whitney R; Morrow, Duane A; Kaufman, Kenton R

2009-06-03

135

Morphological and physiological characteristics of Gemmiger formicilis isolated from chicken ceca.  

PubMed

Morphological and physiological studies were made on chicken cecal isolates of the strictly anaerobic bacterial species Gemmiger formicilis. Structural features (phase-contrast and electron microscopy) of these microorganisms indicate they (i) are highly pleomorphic, (ii) possess a trilaminar cell wall like gram-negative bacteria, (iii) exhibit an unusual growth process characterized by polar swelling (resembling budding bacteria), and (iv) grow into elongated cells when exposed to a subinhibitory concentration of penicillin. The morphological data presented suggest that this species has a rod-shaped structure. These bacteria ferment a variety of sugars to produce formic, butyric, and lactic acids. There appear to be two groups of Gemmiger, one producing primarily lactate and the other producing formate as major fermentation metabolites. Growth of six strains in a basal medium, consisting of Trypticase, minerals, carbohydrate, Na2CO3 buffer, and cysteine as reducing agent, was stimulated by rumen fluid and yeast extract. Volatile fatty acids partially replaced the requirement for rumen fluid with some strains. Single deletions of vitamins (from a defined vitamin mixture) indicated that pantothenate, riboflavin, and thiamine were highly stimulatory to growth of the organism in a medium containing rumen fluid and Trypticase as source of vitamins. Other vitamin requirements were not studied. PMID:984834

Salanitro, J P; Muirhead, P A; Goodman, J R

1976-10-01

136

Morphological and physiological characteristics of Gemmiger formicilis isolated from chicken ceca.  

PubMed Central

Morphological and physiological studies were made on chicken cecal isolates of the strictly anaerobic bacterial species Gemmiger formicilis. Structural features (phase-contrast and electron microscopy) of these microorganisms indicate they (i) are highly pleomorphic, (ii) possess a trilaminar cell wall like gram-negative bacteria, (iii) exhibit an unusual growth process characterized by polar swelling (resembling budding bacteria), and (iv) grow into elongated cells when exposed to a subinhibitory concentration of penicillin. The morphological data presented suggest that this species has a rod-shaped structure. These bacteria ferment a variety of sugars to produce formic, butyric, and lactic acids. There appear to be two groups of Gemmiger, one producing primarily lactate and the other producing formate as major fermentation metabolites. Growth of six strains in a basal medium, consisting of Trypticase, minerals, carbohydrate, Na2CO3 buffer, and cysteine as reducing agent, was stimulated by rumen fluid and yeast extract. Volatile fatty acids partially replaced the requirement for rumen fluid with some strains. Single deletions of vitamins (from a defined vitamin mixture) indicated that pantothenate, riboflavin, and thiamine were highly stimulatory to growth of the organism in a medium containing rumen fluid and Trypticase as source of vitamins. Other vitamin requirements were not studied. Images

Salanitro, J P; Muirhead, P A; Goodman, J R

1976-01-01

137

Molecular and physiological characteristics of a grape yeast strain containing atypical genetic material.  

PubMed

The knowledge about wine yeasts remains largely dominated by the extensive studies on Saccharomyces (S.) cerevisiae. Molecular methods, allowing discrimination of both species and strains in winemaking, can profitably be applied for characterization of the microflora occurring in winemaking and for monitoring the fermentation process. Recently, some novel yeast isolates have been described as hybrid between S. cerevisiae and Saccharomyces species, leaving the Saccharomyces strains containing non-Saccharomyces hybrids essentially unexplored. In this study, we have analyzed a yeast strain isolated from "Primitivo" grape (http://www.ispa.cnr.it/index.php?page=collezioni&lang=en accession number 12998) and we found that, in addition to the S. cerevisiae genome, it has acquired genetic material from a non-Saccharomyces species. The study was focused on the analysis of chromosomal and mitochondrial gene sequences (ITS and 26S rRNA, SSU and COXII, ACTIN-1 and TEF), 2D-PAGE mitochondrial proteins, and spore viability. The results allowed us to formulate the hypothesis that in the MSH199 isolate a DNA containing an rDNA sequence from Hanseniaspora vineae, a non-Saccharomyces yeast, was incorporated through homologous recombination in the grape environment where yeast species are propagated. Moreover, physiological characterization showed that the MSH199 isolate possesses high technological quality traits (fermentation performance) and glycerol production, resistance to ethanol, SO? and temperature) useful for industrial application. PMID:20880601

Cappello, M S; Poltronieri, P; Blaiotta, G; Zacheo, G

2010-08-25

138

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

NASA Astrophysics Data System (ADS)

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 ?M 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 ?M. 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 ?. The ?-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.

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

2012-09-01

139

Infrared spectroscopy of sulfuric acid/water aerosols: Freezing characteristics  

NASA Astrophysics Data System (ADS)

A low-temperature flow cell has been used in conjunction with a Fourier transform infrared (FT-IR) spectrometer to study sulfuric acid/water aerosols. The aerosols were generated with a wide range of composition (28 to 85 wt%), including those characteristic of stratospheric sulfate aerosols, and studied over the temperature range from 240 K to 160 K. The particles exhibited deep supercooling, by as much as 100 K below the freezing point in some cases. Freezing of water ice was observed in the more dilute (<40 wt% sulfuric acid) particles, in agreement with the predictions of Jensen et al. and recent observations by Bertram et al. In contrast with theoretical predictions, however, the entire particle often does not immediately freeze, at least on the timescale of the present experiments (seconds to minutes). Freezing of the entire particle is observed at lower temperatures, well below that characteristic of the polar stratosphere.

Clapp, M. L.; Niedziela, R. F.; Richwine, L. J.; Dransfield, T.; Miller, R. E.; Worsnop, D. R.

1997-04-01

140

Physiological responses of radiata pine roots to soil strength and soil water deficit.  

PubMed

We investigated physiological responses of radiata pine (Pinus radiata D. Don) roots to soil strength and soil water deficit by measuring the osmotic potential (Psi(pi)) and yield turgor (Y) in the elongation zone of root segments of seedlings growing (i) in polyethylene glycol 4000-containing rooting solution of different water potentials (Psi(s)) and (ii) in soil of different soil strengths (Q) at the same soil matric potential (Psi(m)). Root elongation rate (Deltal/Deltat) decreased progressively with decreasing Psi(s) and was associated with decreased Psi(pi) and decreased turgor pressure (P). Osmotic adjustment occurred at Psi(s) < -0.2 MPa. Over a range in Psi(s) of -0.01 to -1.0 MPa, Psi(pi) fell 0.3 MPa whereas P fell 0.7 MPa. Mean Psi in the solution experiment was 0.37 MPa and did not differ significantly with Psi(s) (P = 0.10). Root elongation rate decreased exponentially as Q increased from 0 to 3.0 MPa, and was associated with an increase in P of 0.11 MPa as a consequence of Psi(pi) decreasing by the same amount. Mean Y in the soil experiment was 0.49 MPa and did not change significantly with Q (P = 0.87). PMID:12651497

Zou, Chris; Sands, Roger; Sun, Osbert

2000-11-01

141

[Effects of cinnamic acid and vanillin on grafted eggplant root growth and physiological characteristics].  

PubMed

Choosing Solanum torvum as rootstock and cultivated Xi'anlü eggplant as scion, a pot culture experiment was conducted to study the effects of autotoxic substances (cinnamic acid and vanillin) on the root growth, antioxidase activity, and osmoregulation substances content of grafted eggplant, own-rooted eggplant, and rootstock eggplant. Cinnamic acid and vanillin had allelopathic effects on the root system of test eggplants, with low concentration promoting and higher concentration inhibiting the root growth and physiological metabolism. For own-rooted eggplant, the critical concentration of cinnamic acid and vanillin for promotion or inhibition was 0.1 mmol x kg(-1) and 0.5 mmol x kg(-1), respectively; whereas for grafted and rootstock eggplants, it was 0.5 mmol x kg(-1) and 1 mmol x kg(-1), respectively. The root resistance to autotoxic substances was in the order of root-stock eggplant > grafted eggplant > own-rooted eggplant. Higher concentration cinamic acid (0.5-4 mmol x kg(-1)) and vanillin (1-4 mmol x kg(-1)) enhanced the SOD enzyme activity and the proline and soluble sugar contents of grafted eggplant root by 8.50%-24.50%; 9.39%-27.64%, and 12.77%-81.81%, respectively, compared with own-rooted eggplant. The soluble protein content, fresh mass, dry mass, and root activity of grafted eggplant roots were significantly higher than those of own-rooted eggplant, suggesting that grafted eggplant had a strong resistance of rootstocks to autotoxic substances, which alleviated the negative effect of autotoxic substances on root growth. PMID:20873619

Chen, Shao-Li; Zhou, Bao-Li; Lin, Shan-Shan; Li, Xia; Ye, Xue-Ling

2010-06-01

142

Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures  

Microsoft Academic Search

An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (H2O(l)), and hydrogen peroxide (H2O2) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio (?), and concentration of H2O2 in H2O(l) oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial pressure range

J. L. Sabourin; G. A. Risha; R. A. Yetter; S. F. Son; B. C. Tappan

2008-01-01

143

Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures  

Microsoft Academic Search

An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (HO{sub (l)}), and hydrogen peroxide (HO) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio (), and concentration of HO in HO{sub (l)} oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial

J. L. Sabourin; R. A. Yetter; G. A. Risha; S. F. Son; B. C. Tappan

2008-01-01

144

Infrared spectroscopy of sulfuric acid\\/water aerosols: Freezing characteristics  

Microsoft Academic Search

A low-temperature flow cell has been used in conjunction with a Fourier transform infrared (FT-IR) spectrometer to study sulfuric acid\\/water aerosols. The aerosols were generated with a wide range of composition (28 to 85 wt %), including those characteristic of stratospheric sulfate aerosols, and studied over the temperature range from 240 K to 160 K. The particles exhibited deep supercooling,

M. L. Clapp; R. F. Niedziela; L. J. Richwine; T. Dransfield; R. E. Miller; D. R. Worsnop

1997-01-01

145

Physical and Water Absorption Characteristics of Some Improved Rice Varieties  

Microsoft Academic Search

The physical and water absorption characteristics of paddy and brown rice from some early maturing Oryza sativa varieties and newly developed interspecific (O. sativa × Oryza glaberrima) rice varieties were studied. The physical dimensions (length, breadth and width, length\\/width ratio, equivalent diameter),\\u000a grain surface area and volume, sphericity, 1,000-kernel weight, bulk and true densities as well as porosity were determined.

Taofik Akinyemi Shittu; M. B. Olaniyi; A. A. Oyekanmi; K. A. Okeleye

146

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

Microsoft Academic Search

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)

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

1991-01-01

147

[Physiological and biochemical characteristics of fungi of the genus Penicillium as producers of ergot alkaloids and quinocitrinins].  

PubMed

Four cultures of fungi of the genus Penicillium belonging to Furcatum Pitt subgenus, such as P. citrinum Thom, 1910; P. corylophilum Dierckx, 1901; P. fellutanum Biourge, 1923; and P. waksmanii Zaleski, 1927, produced the ergot alkaloids, namely, agroclavine-I, and epoxyagroclavine-I; their N-N-dimers, such as dimer of epoxyagroclavine-I and the mixed dimer of epoxyagroclavine-I and agroclavine-I; and also quinoline metabolites, namely, quinocitrinin A and quinocitrinin B. Physiological and biochemical characteristics of the producers were studied. Optimal conditions for the biosynthesis of metabolome components were determined. Zinc additive to the medium stimulated the biosynthesis of the ergot alkaloids in all cases; citrinin production was increased only in P. citrinum, and that was suppressed in P. corylophinum, P. fellutanum, and P. waksmanii. This testifies that genes of the biosynthesis pathways are located in the different clusters of the producers. PMID:21950123

Kozlovski?, A G; Zhelifonova, V P; Antipova, T V; Zelenkova, N F

148

The physiology and toxicology of salmonid eggs and larvae in relation to water quality criteria.  

PubMed

The purpose of this review is to collate physiological knowledge on salmonid eggs and larvae in relation to water quality criteria. Salmonid genera reviewed include Coregonus, Thymallus, Salvelinus, Salmo, and Oncorhynchus spp. When physiological data for salmonids are lacking, the zebrafish and medaka models are included. The primary focus is on the underlying mechanisms involved in the hydro-mineral, thermal, and respiratory biology with an extended section on the xenobiotic toxicology of the early stages. Past and present data reveal that the eggs of salmonids are among the largest shed by any broadcast spawning teleost. Once ovulated, the physicochemical properties of the ovarian fluid provide temporary protection from external perturbations and maintain the eggs in good physiological condition until spawning. Following fertilisation and during early development the major structures protecting the embryo from poor water quality are the vitelline membrane, the enveloping layer and the chorion. The vitelline membrane is one of the least permeable membranes known, while the semi-permeable chorion provides both physical and chemical defense against metals, pathogens, and xenobiotic chemicals. In part these structures explain the lower sensitivity of the eggs to chemical imbalance compared to the larvae, however the lower metabolic rate and the chronology of gene expression and translational control suggest that developmental competence also plays a decisive role. In addition, maternal effect genes provide a defense potential until the mid-blastula transition. The transition between maternal effect genes and zygotic genes is a critical period for the embryo. The perivitelline fluids are an important trap for cations, but are also the major barrier to diffusion of gases and solutes. Acidic environmental pH interferes with acid-base and hydromineral balance but also increases the risk of aluminium and heavy metal intoxication. These risks are ameliorated somewhat by the presence of ambient humic acid. High temperatures during development may be teratogenic, cause sexual bias, or long-term effects on muscle cellularity. Xenobiotics cause inhibition of neural acetylcholine esterase and carboxylases and disrupt the normal signalling pathways of hormones by binding to relevant receptors and mimicking their actions. A complex suite of genes is activated in response to environmental or parentally transmitted xenobiotics. The primary defense mechanism in embryos involves resistance to uptake but later biotransformation via the aryl hydrocarbon receptor (AHR)-mediated activation of members of the cytochrome mixed-function mono-oxygenase superfamily (CYP1A, CYP2B, and CYP3A) and subsequent glucuronidation or glutathionation. Due to the number of duplicate or triplicate genes coding for intermediates in the signalling pathways, and cross-talk between nuclear orphan receptors and steroid hormone receptors, a large number of complications arise in response to xenobiotic intoxicaton. One such syndrome, known as blue-sac disease causes an anaphylactoid response in hatched larvae due to increased permeability in the vascular endothelium that coincides with AHR-mediated CYP induction. Early embryos also respond to such xenobiotic insults, but apparently have an immature translational control for expression of CYP proteins, which coincides with a lack of excretory organs necessary for the end-point of biotransformation. Other syndromes (M74 and Cayuga) are now associated with thiamine deficiency. Where possible guidelines for water quality criteria are suggested. PMID:17316838

Finn, Roderick Nigel

2007-01-23

149

Effect of seedling age and water depth on morphological and physiological aspects of transplanted rice under high temperature.  

PubMed

To study the effect of high temperature, rice seedlings 20, 30, 40 and 50 d were kept at 5, 10, 15 and 20 cm water depth in a water pool. Meteorological findings indicated that water temperature varied up to 10 cm but became stable below this depth. Deep water inflicted higher tiller mortality, minimal increase in dry weight of aerial parts and leaf area, decrease in root length, and decrease in root dry weight especially at 20 cm water depth and produced an unbalanced T/R ratio (top versus root dry weight). However, deep water tended to increase plant length. These parameters, however, excel in shallow water. Older seedlings, with the exception of root dry weight, could not perform well compared to young seedlings in all physiological and morphological aspects. The study revealed that seedlings, particularly young ones, stand well in shallow water and can cope with high temperature. PMID:15822153

Khakwani, Abdul Aziz; Shiraishi, Masaaki; Zubair, Muhammad; Baloch, Mohammad Safdar; Naveed, Khalid; Awan, Inayatullah

2005-05-01

150

What is the biochemical and physiological rationale for using cold-water immersion in sports recovery? A systematic review  

Microsoft Academic Search

Cold-water immersion (CWI) is a popular recovery intervention after exercise. The scientific rationale is not clear, and there are no clear guidelines for its use. The aim of this review was to study the physiological and biochemical effect of short periods of CWI. A computer-based literature search, citation tracking and related articles searches were undertaken. Primary research studies using healthy

Chris M Bleakley; Gareth W Davison

2010-01-01

151

Physiological effects of aluminum on rainbow trout in acidic soft water, with emphasis on the gill micro-environment  

Microsoft Academic Search

This thesis examined the physiological and toxicological effects of Al (-100 ?g.L?¹) in acidic soft water (pH 4.0-6.5) on the rainbow trout (Salmo gairdneri = Oncorhynchus mykiss), and the mechanisms of Al deposition on the gills. Cannulated trout exposed for 66 h to Al in synthetic soft water (Ca²? = 45 or 410 ?equiv.L?¹) showed highest mortality at pH 5.2,

Richard Colin Playle

1989-01-01

152

Physiological effects of aluminum on rainbow trout in acidic soft water, with emphasis on the gill micro-environment  

Microsoft Academic Search

This thesis examined the physiological and toxicological effects of AL ($\\\\sim$100 $\\\\mu$g.L$\\\\sp{-1}$) in acidic soft water (pH 4.0-6.5) on the rainbow trout (Salmo gairdneri = Oncorhynchus mykiss), and the mechanisms of Al deposition on the gills. Cannulated trout exposed for 66 h to Al in synthetic soft water (Ca$\\\\sp{2+}$ = 45 or 410 $\\\\mu$equiv.L$\\\\sp{-1}$) showed highest mortality at pH 5.2,

Richard Colin Playle

1990-01-01

153

The effects of irrigation regimes on the water use, dry matter production and physiological responses of paddy rice  

Microsoft Academic Search

In most cases, rice production is associated with flooding irrigation and the efficiency of irrigated water use (WUEi) is\\u000a generally lower for production of rice than for other crops. We have examined the effects of various irrigation regimes on\\u000a water consumption in a well-puddled paddy field, as well as on dry matter production, grain yield and physiological responses\\u000a of the

Jun Lu; Taiichiro Ookawa; Tadashi Hirasawa

2000-01-01

154

Soil and water characteristics of a young surface mine wetland  

NASA Astrophysics Data System (ADS)

Coal companies are reluctant to include wetland development in reclamation plans partly due to a lack of information on the resulting characteristics of such sites. It is easier for coal companies to recreate terrestrial habitats than to attempt experimental methods and possibly face significant regulatory disapproval. Therefore, we studied a young (10 years) wetland on a reclaimed surface coal mine in southern Illinois so as to ascertain soil and water characteristics such that the site might serve as a model for wetland development on surface mines. Water pH was not measured because of equipment problems, but evidence (plant life, fish, herpetofauna) suggests suitable pH levels. Other water parameters (conductivity, salinity, alkalinity, chloride, copper, total hardness, iron, manganese, nitrate, nitrite, phosphate, and sulfate) were measured, and only copper was seen in potentially high concentrations (but with no obvious toxic effects). Soil variables measured included pH, nitrate, nitrite, ammonia, potassium, calcium, magnesium, manganese, aluminum, iron, sulfate, chloride, and percent organic matter. Soils were slightly alkaline and most parameters fell within levels reported for other studies on both natural and manmade wetlands. Aluminum was high, but this might be indicative more of large amounts complexed with soils and therefore unavailable, than amounts actually accessible to plants. Organic matter was moderate, somewhat surprising given the age of the system.

Andrew Cole, C.; Lefebvre, Eugene A.

1991-05-01

155

Influence of air and water temperature on fill characteristics curve  

SciTech Connect

In a previous paper, the author discussed approximations of the Merkel Theory, as well as other approximations included in the CTI recommended method of calculation of the Demand curves. The paper concluded that the familiar difference of enthalpies, used as a cooling potential, which is the Merkel Theory, could continue to be used by simply adding a corrective multiplying factor derived from a direct comparison of the exact theory and the Merkel Theory. At the end of the paper the author briefly showed that the corrections to the Demand curve was only one part of the picture and that there was also an influence of the temperatures of the Characteristic curve side. The object of this paper is to now review the influence of the air and water temperature on the Characteristic curve. This completes the work presented last year.

Lefevre, M.R.

1985-01-01

156

Thrust Characteristics of Water Rocket and Their Improvement  

NASA Astrophysics Data System (ADS)

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.

Watanabe, Rikio; Tomita, Nobuyuki; Takemae, Toshiaki

157

Characteristic mega-basin water storage behavior using GRACE  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

158

Physiological Maturity in Wheat Based on Kernel Water and Dry Matter  

Microsoft Academic Search

desiccants or windrowing) without reducing wheat yield, thereby providing better returns in double-crop systems. Estimation of the time of physiological maturity could be beneficial The most precise method of determining the time of to avoid yield penalties due to lodging, sprouting, hail, and other harvest risks. The aim of our study was to evaluate a simple empirical physiological maturity in

Daniel F. Calderini; Leonor G. Abeledo; Gustavo A. Slafer

2000-01-01

159

[Human physiology: kidney].  

PubMed

The content of human physiology as an independent part of current physiology is discussed. Substantiated is the point that subjects of human physiology are not only special sections of physiology where functions are inherent only in human (physiology of intellectual activity, speech, labor, sport), but also in peculiarities of functions, specificity of regulation of each of physiological systems. By the example of physiology of kidney and water-salt balance there are shown borders of norm, peculiarities of regulation in human, new chapters of renal physiology which have appeared in connection with achievements of molecular physiology. PMID:21061667

Natochin, Iu V

160

Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type  

Microsoft Academic Search

Psychopharmacological studies using caffeinated beverages or caffeine have rarely considered temporal effects on psychological\\u000a and physiological function or the specific contribution of caffeine, hot water, or beverage type to the observed effects.\\u000a The effect of 400?ml hot tea, coffee, and water consumption on systolic and diastolic blood pressure (SBP and DBP), heart\\u000a rate, skin conductance (a measure of sympathetic nervous

P. Quinlan; Laurence Aspinall

1997-01-01

161

Relationship between characteristics of water polo players and efficacy indices.  

PubMed

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

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

2012-07-01

162

Physiological performance of an Alaskan shrub (Alnus fruticosa) in response to disease (Valsa melanodiscus) and water stress.  

PubMed

• Following the decades-long warming and drying trend in Alaska, there is mounting evidence that temperature-induced drought stress is associated with disease outbreaks in the boreal forest. Recent evidence of this trend is an outbreak of Cytospora canker disease (fungal pathogen Valsa melanodiscus (anamorph = Cytospora umbrina)) on Alnus species. • For Alnus fruticosa, we examined the effects of water stress on disease predisposition, and the effects of disease and water stress on host physiology. In two trials, we conducted a full-factorial experiment that crossed two levels of water stress with three types of inoculum (two isolates of V. melanodiscus, one control isolate). • Water stress was not required for disease predisposition. However, the effects of water stress and disease on host physiology were greatest near the peak phenological stage of the host and during hot, dry conditions. During this time, water stress and disease reduced light-saturated photosynthesis (-30%), light saturation point (-60%) and stomatal conductance (-40%). • Our results depended on the timing of water stress and disease in relation to host phenology and the environment. These factors should not be overlooked in attempts to generalize predictions about the role of temperature-induced drought stress in this pathosystem. PMID:20868393

Rohrs-Richey, Jennifer K; Mulder, Christa P H; Winton, Loretta M; Stanosz, Glen

2010-09-24

163

Study of the physiological characteristics of the medicinal mushroom Trametes pubescens (higher Basidiomycetes) during the laccase-producing process.  

PubMed

The study of the physiological characteristics of the medicinal mushroom Trametes pubescens was conducted under submerged cultures, suggesting that the laccase activity was positively correlated with oxidative level and culture conditions. Mycelial biomass and laccase activity in medium I were higher than those in medium II, which indicated that laccase activity was correlated with mycelium growth. The enhancement in mycelial biomass presented the logarithmic increase at days 6-8 and the peak value on the day 12 after inoculation. During liquid cultivation, increases in the amounts of malondialdehyde, hydrogen peroxide, and ascorbic acid were observed. In addition, the higher activities of superoxide dismutase and total antioxidative capacity still could be detected during this period. However, better ability to restrain hydroxyl free radical and catalase had a negative influence on laccase activity. It was evident that the fungal strain T. pubescens was under oxidative stress during the laccase-producing process. When the concentrations of H2O2 and Fe2+ were 3 and 30 mmol/L, respectively, the laccase activity reached to its peak at 37.21 U/L after a 14-day incubation period. It was concluded that a relationship between laccase synthesis and antioxidative capability existed in fungal cells, which could be regulated by reactive oxygen. PMID:23557372

Si, Jing; Cui, Bao-Kai

2013-01-01

164

Physiological characteristics of National Collegiate Athletic Association Division I ice hockey players and their relation to game performance.  

PubMed

Previous ice hockey research has focused on physiological profiles and determinants of skating speed, but few studies have examined the association of preseason player evaluations with a measure of season-long performance. Understanding which tests are most predictive of player performance could help coaches organize practice and training more effectively. The purpose of this study was to describe physical characteristics and skill levels of 24 members of an NCAA Division I men's ice hockey team and relate them to game performance over the course of a season as measured by plus/minus (+/-) score. Subjects performed a battery of preseason tests including treadmill maximal aerobic capacity, body fat, leg press, push-ups, bench press, chin-ups, and sprinting ability both on and off ice. Pearson and Spearman correlations were used to examine correlations between preseason measures and +/- score. One coach also subjectively grouped the top and bottom 6 players, and analysis of variance was used to examine any differences in preseason measures and +/- score between these 2 groups. Leg press, chin-ups, bench press, and repeat sprint performance were significantly correlated with +/- score (r = 0.554, 0.462, 0.499, and -0.568, respectively). Teams with limited time and resources may choose to perform these tests to evaluate player potential efficiently. Only +/- score differed between top and bottom players suggesting that +/- accurately reflected the coach's perception of player success in this sample. PMID:21478763

Peyer, Karissa L; Pivarnik, James M; Eisenmann, Joey C; Vorkapich, Michael

2011-05-01

165

Regurgitant flow field characteristics of the St. Jude bileaflet mechanical heart valve under physiologic pulsatile flow using particle image velocimetry.  

PubMed

The regurgitant flow fields of clinically used mechanical heart valves have been traditionally studied in vitro using flow visualization, ultrasound techniques, and laser Doppler velocimetry under steady and pulsatile flow. Detailed investigation of the forward and regurgitant flow fields of these valves can elucidate a valve's propensity for blood element damage, thrombus formation, or cavitation. Advances in particle image velocimetry (PIV) have allowed its use in the study of the flow fields of prosthetic valves. Unlike other flow field diagnostic systems, recent work using PIV has been able to relate particular regurgitant flow field characteristics of the Bjork-Shiley Monostrut valve to a propensity for cavitation. In this study, the regurgitant flow field of the St. Jude Medical bileaflet mechanical heart valve was assessed using PIV under physiologic pulsatile flow conditions. Data collected at selected time points prior to and after valve closure demonstrated the typical regurgitant jet flow patterns associated with the St. Jude valve, and indicated the formation of a strong regurgitant jet, in the B-datum plane, along with twin vortices near the leaflets. Estimated ensemble-average viscous shear rates suggested little potential for hemolysis when the hinge jets collided. However, the vortex motion near the occluder tips potentially provides a low-pressure environment for cavitation. PMID:12940907

Manning, Keefe B; Kini, Vinayak; Fontaine, Arnold A; Deutsch, Steven; Tarbell, John M

2003-09-01

166

Identification of high gamma-aminobutyric acid producing marine yeast strains by physiological and biochemical characteristics and gene sequence analyses.  

PubMed

Four marine yeasts isolated from the Pacific Ocean off Japan (Siki No. 4, Siki No. 15, Hach No. 6, and Inub No. 11), which showed high gamma-aminobutyric acid (GABA) producing abilities, were identified and classified by physiological and biochemical characteristics and gene sequence analyses. Analysis of biochemical data suggested that while Siki No. 15 was identical to Candida, the remaining three isolates belonged to the genus Pichia. However, these data were insufficient to resolve their identity at the species level. Subsequently, analysis of the 5.8S rRNA genes and the two internal transcribed spacer regions (ITS) sequences revealed that Siki No. 15 belongs to Pichia guilliermondii, while the remaining three isolates corresponded to Pichia anomala. Since Siki No. 4 showed slightly different biochemical properties than the other two isolates, which were otherwise identical, we sought to investigate the sequences of the intergenic spacer region 1 (IGS1). We observed few nucleotide changes, suggesting that the Hach No. 6 and Inub No. 11 isolates belong to different but new strains for which we propose the names P. anomola MR-1 and MR-2 respectively. PMID:19584549

Guo, Xiao-feng; Aoki, Hitoshi; Hagiwara, Toshihiko; Masuda, Kazuaki; Watabe, Shugo

2009-07-07

167

Atomization characteristics of coal-water slurry. Final report  

SciTech Connect

Dwindling supplies of oil have led to increasing interest in alternative fuels which can be used to replace petroleum-derived liquid fuels. One such fuel is coal-water slurry. This study presents the atomization behavior of coal-water slurries at conditions typical of a gas turbine combustor. Slurry spray characteristics were determined using five different types of atomizer. The five nozzle types included were: (1) plain-orifice, (2) pressure-swirl, (3) plain-jet airblast, (4) air-assist and (5) prefilming airblast. The effects of airblast air velocity, chamber pressure and air-to-fuel mass ratio (AFR) on SMD were investigated for the latter three nozzle types. Values of SMD were determined for levels of tank pressure between 1 and 2.0 MPa, air-to-fuel mass ratios (AFR) between 0.5 and 6.0, and airblast air velocities between 30 and 100 m/sec. Several slurries with loadings between 50 and 70% (by weight) were used. The Sauter mean diameter and drop size distribution parameter were measured using the forward light-scattering technique in the form of a commercially available Malvern 2600 particle size analyzer. Droplet microstructure was determined using the liquid nitrogen-freezing technique and spray radial and circumferential patternation data were obtained through the use of a patternator. 39 refs., 64 figs., 4 tabs.

Lefebvre, A.H.; Sojka, P.E.

1986-02-01

168

The Characteristics of Sleepiness During Real Driving at Night--A Study of Driving Performance, Physiology and Subjective Experience  

PubMed Central

Study Objectives: Most studies of sleepy driving have been carried out in driving simulators. A few studies of real driving are available, but these have used only a few sleepiness indicators. The purpose of the present study was to characterize sleepiness in several indicators during real driving at night, compared with daytime driving. Design: Participants drove 55 km (at 90km/h) on a 9-m-wide rural highway in southern Sweden. Daytime driving started at 09:00 or 11:00 (2 groups) and night driving at 01:00 or 03:00 (balanced design). Setting: Instrumented car on a real road in normal traffic. Participants: Eighteen participants drawn from the local driving license register. Interventions: Daytime and nighttime drives. Measurement and Results: The vehicle was an instrumented car with video monitoring of the edge of the road and recording of the lateral position and speed. Electroencephalography and electrooculography were recorded, together with ratings of sleepiness every 5 minutes. Pronounced effects of night driving were seen for subjective sleepiness, electroencephalographic indicators of sleepiness, blink duration, and speed. Also, time on task showed significant effects for subjective sleepiness, blink duration, lane position, and speed. Sleepiness was highest toward the end of the nighttime drive. Night driving caused a leftward shift in lateral position and a reduction of speed. The latter two findings, as well as the overall pattern of sleepiness indicators, provide new insights into the effects of night driving. Conclusion: Night driving is associated with high levels of subjective, electrophysiologic, and behavioral sleepiness. Citation: Sandberg D; Anund A; Fors C; Kecklund G; Karlsson JG; Wahde M; Åkerstedt T. The characteristics of sleepiness during real driving at night—a study of driving performance, physiology and subjective experience. SLEEP 2011;34(10):1317-1325.

Sandberg, David; Anund, Anna; Fors, Carina; Kecklund, Goran; Karlsson, Johan G.; Wahde, Mattias; Akerstedt, Torbjorn

2011-01-01

169

Water Quality Assessment Based on Chemical and Biological Characteristics: An Example of Classification of Characteristics for the Cheremushnyi Creek–Yenisey River Water System  

Microsoft Academic Search

A six-class scale for a complex classifier of water quality is applied to the Cheremushnyi Creek–Yenisey River water system. The classifier incorporates a chemical index of water pollution and biological characteristics with autotrophic and heterotrophic periphyton groups and macrozoobenthos used as biological indicators. The oligochaeta index and Woodiwiss biotic index are shown to have low indicator capacity. Bioassay studies were

Z. G. Gol'd; L. A. Glushchenko; I. I. Morozova; S. P. Shulepina; I. A. Shadrin

2003-01-01

170

Physiological and morphological responses to water stress in two Acacia species from contrasting habitats  

Microsoft Academic Search

Summary Container-grown seedlings of Acacia tortilis Forsk. Hayne and A. xanthophloea Benth. were watered either every other day (well watered) or every 7 days (water-stressed) for 1 year in a greenhouse. Total plant dry mass (Tdm), carbon allocation and water relations were measured monthly. Differ- ences in leaf area (LA) accounted for differences in Tdm be- tween the species, and

D. O. OTIENO; M. W. T. SCHMIDT; S. ADIKU; J. TENHUNEN

171

Soil Water Characteristic Estimates by Texture and Organic Matter for Hydrologic Solutions  

Microsoft Academic Search

Hydrologic analyses often involve the evaluation of soil water in- filtration, conductivity, storage, and plant-water relationships. To de- fine the hydrologic soil water effects requires estimating soil water characteristics for water potential and hydraulic conductivity using soil variables such as texture, organic matter (OM), and structure. Field or laboratory measurements are difficult, costly, and often impractical for many hydrologic analyses.

K. E. Saxton; W. J. Rawls

2006-01-01

172

Physiological responses of cobia Rachycentron canadum following exposure to low water and air exposure stress challenges  

Microsoft Academic Search

Prevention is the most viable disease management strategy in aquaculture, and prevention is primarily driven by strategies to avoid or minimize the effects of stress. Unfortunately, there is little information available regarding the stress physiology of emerging aquaculture species or appropriate experimental stressing protocols for these fishes, and thus very little context in which to evaluate mitigation strategies. Accordingly, the

J. Trushenski; M. Schwarz; R. Takeuchi; B. Delbos; L. A. Sampaio

2010-01-01

173

Fog interception by Sequoia sempervirens (D. Don) crowns decouples physiology from soil water deficit.  

PubMed

Although crown wetting events can increase plant water status, leaf wetting is thought to negatively affect plant carbon balance by depressing photosynthesis and growth. We investigated the influence of crown fog interception on the water and carbon relations of juvenile and mature Sequoia sempervirens trees. Field observations of mature trees indicated that fog interception increased leaf water potential above that of leaves sheltered from fog. Furthermore, observed increases in leaf water potential exceeded the maximum water potential predicted if soil water was the only available water source. Because field observations were limited to two mature trees, we conducted a greenhouse experiment to investigate how fog interception influences plant water status and photosynthesis. Pre-dawn and midday branchlet water potential, leaf gas exchange and chlorophyll fluorescence were measured on S. sempervirens saplings exposed to increasing soil water deficit, with and without overnight canopy fog interception. Sapling fog interception increased leaf water potential and photosynthesis above the control and soil water deficit treatments despite similar dark-acclimated leaf chlorophyll fluorescence. The field observations and greenhouse experiment show that fog interception represents an overlooked flux into the soil-plant-atmosphere continuum that temporarily, but significantly, decouples leaf-level water and carbon relations from soil water availability. PMID:19302173

Simonin, Kevin A; Santiago, Louis S; Dawson, Todd E

2009-03-03

174

Physiology of Phototrophy and Heterotrophy in Algae with Contrasting Nutritional Characteristics, 'Pyrenomonas salina' (Cryptophyceae) and 'Poterioochromonas malhamensis' (Chrysophyceae).  

National Technical Information Service (NTIS)

The ability of algae to take up dissolved organic compounds is well-documented for cultured and field populations yet the physiological mechanisms controlling the behavior are largely unknown. The effects of dissolved organic compound additions on the gro...

A. J. Lewitus

1990-01-01

175

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

SciTech Connect

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.

Murthy, R.; Dougherty, P.M. (North Carolina State Univ., Raleigh, NC (United States))

1994-06-01

176

Physiological Adaptations of Salmonid Fishes (Salmo clarki henshawi, Salmo gairdneri, and Oncorhynchus kisutch) to Alkaline Saline Water and Its Toxic Effects.  

National Technical Information Service (NTIS)

Two studies were conducted to determine the physiological adaptations of 3 salmonid fishes to the alkaline, slightly saline waters of Pyramid Lake, NV, and their toxic effects. In the acclimation study, growth rates and blood parameters of fingerling Laho...

D. L. Koch J. Knoll J. Sommer L. Hoffman R. Knoll

1979-01-01

177

Applying additive logistic regression to data derived from sensors monitoring behavioral and physiological characteristics of dairy cows to detect lameness.  

PubMed

The hypothesis was that sensors currently available on farm that monitor behavioral and physiological characteristics have potential for the detection of lameness in dairy cows. This was tested by applying additive logistic regression to variables derived from sensor data. Data were collected between November 2010 and June 2012 on 5 commercial pasture-based dairy farms. Sensor data from weigh scales (liveweight), pedometers (activity), and milk meters (milking order, unadjusted and adjusted milk yield in the first 2min of milking, total milk yield, and milking duration) were collected at every milking from 4,904 cows. Lameness events were recorded by farmers who were trained in detecting lameness before the study commenced. A total of 318 lameness events affecting 292 cows were available for statistical analyses. For each lameness event, the lame cow's sensor data for a time period of 14d before observation date were randomly matched by farm and date to 10 healthy cows (i.e., cows that were not lame and had no other health event recorded for the matched time period). Sensor data relating to the 14-d time periods were used for developing univariable (using one source of sensor data) and multivariable (using multiple sources of sensor data) models. Model development involved the use of additive logistic regression by applying the LogitBoost algorithm with a regression tree as base learner. The model's output was a probability estimate for lameness, given the sensor data collected during the 14-d time period. Models were validated using leave-one-farm-out cross-validation and, as a result of this validation, each cow in the data set (318 lame and 3,180 nonlame cows) received a probability estimate for lameness. Based on the area under the curve (AUC), results indicated that univariable models had low predictive potential, with the highest AUC values found for liveweight (AUC=0.66), activity (AUC=0.60), and milking order (AUC=0.65). Combining these 3 sensors improved AUC to 0.74. Detection performance of this combined model varied between farms but it consistently and significantly outperformed univariable models across farms at a fixed specificity of 80%. Still, detection performance was not high enough to be implemented in practice on large, pasture-based dairy farms. Future research may improve performance by developing variables based on sensor data of liveweight, activity, and milking order, but that better describe changes in sensor data patterns when cows go lame. PMID:24011945

Kamphuis, C; Frank, E; Burke, J K; Verkerk, G A; Jago, J G

2013-09-05

178

Physiological Effects of Chronic Copper Exposure to Rainbow Trout (Oncorhynchus Mykiss) in Hard and Soft Water: Evaluation of Chronic Indicators  

Microsoft Academic Search

Effects of chronic copper exposure on a suite of indicators were examined: acute toxicity, acclimation, growth, sprint performance, whole-body electrolytes, tissue residues, and gill copper binding characteristics. Juvenile rainbow trout were exposed for 30 d to waterborne copper in hard water (hardness = 120 ?g\\/L as CaCO3, pH = 8.0, Cu = 20 and 60 ?g\\/L) and soft water (hardness

Lisa N. Taylor; James C. McGeer; Chris M. Wood; D. Gordon McDonald

2000-01-01

179

Water supplementation affects the behavioral and physiological ecology of Gila monsters (Heloderma suspectum) in the Sonoran Desert.  

PubMed

In desert species, seasonal peaks in animal activity often correspond with times of higher rainfall. However, the underlying reason for such seasonality can be hard to discern because the rainy season is often associated with shifts in temperature as well as water and food availability. We used a combination of the natural climate pattern of the Sonoran Desert and periodic water supplementation to determine the extent to which water intake influenced both the behavioral ecology and the physiological ecology of a long-lived desert lizard, the Gila monster (Heloderma suspectum) (Cope 1869). Water-supplemented lizards had lower plasma osmolality (i.e., were more hydrated) and maintained urinary bladder water reserves better during seasonal drought than did control lizards. During seasonal drought, water-supplemented lizards were surface active a significantly greater proportion of time than were controls. This increased surface activity can lead to greater food acquisition for supplemental Gila monsters because tail volume (an index of caudal lipid stores) was significantly greater in supplemented lizards compared with controls in one of the two study years. PMID:19799522

Davis, Jon R; DeNardo, Dale F

180

A Study on Heat Transfer Characteristics of Water Cooled LO2/LH2 Rocket Combustor.  

National Technical Information Service (NTIS)

The amount of enthalpy increase of coolant in regeneratively cooled engines was investigated. A water cooled calorimetric combustor was used to determine the local heat flux distribution along the axis and the boiling characteristics of cooling water unde...

M. Niino A. Kumakawa N. Yatuyanagi H. Gomi A. Suzuki

1982-01-01

181

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

182

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

PubMed Central

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.

2013-01-01

183

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

PubMed

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

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

2013-07-26

184

ON THE BURNING CHARACTERISTICS OF COLLISION-GENERATED WATER\\/HEXADECANE DROPLETS  

Microsoft Academic Search

The combustion characteristics of freely falling droplets, individually generated by the merging of colliding water and hexadecane droplets, were investigated and compared with those for pure hexadecane and emulsified water\\/hexadecane droplets. The merging of the nominally nonmiscible hexadecane and water was manifested either in an apparently adhesive manner, or with the water droplet inserting into the hexadecane droplet. The latter,

C. H. WANG; C. Z. LIN; W. G. HUNG; W. C. HUANG; C. K. LAW

2004-01-01

185

Characteristics of optical breakdown in ultrapure water induced by nanosecond Nd:YAG laser pulses  

Microsoft Academic Search

Characteristics of dielectric breakdown in ultrapure liquid water using single nanosecond laser pulses have been investigated. The threshold for the systematic occurrence of laser-induced breakdown of ultrapure water has been found to be about one order of magnitude below the threshold of distilled water, and of impurity-rich liquids like ordinary tap water. The behaviour of the threshold value in relation

F. Docchio; A. Avigo; R. Palumbo

1991-01-01

186

Estimation of turbulence characteristic scales in a water cell  

NASA Astrophysics Data System (ADS)

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).

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

2012-10-01

187

Physiological and behavioral responses to different watering intervals in lactating camels (Camelus dromedarius).  

PubMed

During drought periods camels are watered at long intervals, but effects on body fluid homeostasis of lactating camels are not known. It was hypothesized that camels store water after drinking and minimize water losses by diurnal variation in body temperature, changes in behavior, and release of vasopressin. The aim was to find a sustainable watering interval for lactating camels. Seven lactating camels were studied in a cross-over trial in which they were watered once daily (W1), every fourth day (W4), every eighth day (W8), or after 16 days (W16) with a 5-day interval between treatments. When offered water every fourth or eighth days, the camels drank sufficient amounts to cover their needs for subsequent days, but after 16 days of dehydration they did not drink enough to compensate the body weight loss. Rectal temperature fell at night and the camels searched shade during daytime minimizing evaporative fluid losses. Plasma osmolality and sodium concentration were elevated after 4 days of water deprivation and plasma protein and vasopressin concentrations after 8 days. Milk production decreased during the last week of W16. Plasma aldosterone concentration was elevated upon rehydration after W16, indicating sodium deficiency. In conclusion, lactating camels stored water after drinking and reduced water losses by staying in shade, keeping body temperature low, and releasing plasma vasopressin. However, serious dehydration was observed during W8, and after 16 days of water deprivation recovery took a long time. A watering interval between 4 and 7 days seems advisable under similar environmental conditions. PMID:23842680

Bekele, Tafesse; Olsson, Kerstin; Olsson, Ulf; Dahlborn, Kristina

2013-07-10

188

Root water uptake and transport: using physiological processes in global predictions  

Microsoft Academic Search

Plant water loss, regulated by stomata and driven by atmospheric demand, cannot exceed the maximum steady-state supply through roots. Just as an electric circuit breaks when carrying excess current, the soil–plant continuum breaks if forced to transport water beyond its capacity. Exciting new molecular, biophysical and ecological research suggests that roots are the weakest link along this hydraulic flow path.

Robert B. Jackson; John S. Sperry; Todd E. Dawson

2000-01-01

189

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

PubMed

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

Durban, J W; Pitman, R L

2011-10-26

190

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

PubMed Central

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.

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

2012-01-01

191

Assessing environmental and physiological controls over water relations in a Scots pine (Pinus sylvestris L.) stand through analyses of stable isotope composition of water and organic matter.  

PubMed

This study investigated the influence of meteorological, pedospheric and physiological factors on the water relations of Scots pine, as characterized by the origin of water taken up, by xylem transport as well as by carbon isotope discrimination (Delta13C) and oxygen isotope enrichment (Delta18O) of newly assimilated organic matter. For more than 1 year, we quantified delta2H and delta18O of potential water sources and xylem water as well as Delta13C and Delta18O in twig and trunk phloem organic matter biweekly, and related these values to continuously measured or modelled meteorological parameters, soil water content, stand transpiration (ST) and canopy stomatal conductance (G(s)). During the growing season, delta18O and delta2H of xylem water were generally in a range comparable to soil water from a depth of 2-20 cm. Long residence time of water in the tracheids uncoupled the isotopic signals of xylem and soil water in winter. Delta18O but not Delta13C in phloem organic matter was directly indicative of recent environmental conditions during the whole year. Delta18O could be described applying a model that included 18O fractionation associated with water exchange between leaf and atmosphere, and with the production of organic matter as well as the influence of transpiration. Phloem Delta13C was assumed to be concertedly influenced by G(s) and photosynthetically active radiation (PAR) (as a proxy for photosynthetic capacity). We conclude that isotope signatures can be used as effective tools (1) to characterize the seasonal dynamics in source and xylem water, and (2) to assess environmental effects on transpiration and G(s) of Scots pine, thus helping to understand and predict potential impacts of climate change on trees and forest ecosystems. PMID:17177880

Brandes, Elke; Wenninger, Jochen; Koeniger, Paul; Schindler, Dirk; Rennenberg, Heinz; Leibundgut, Christian; Mayer, Helmut; Gessler, Arthur

2007-01-01

192

Impact of changes in natural UV radiation on pigment composition, physiological and morphological characteristics of the Antarctic moss, Grimmia antarctici  

Microsoft Academic Search

The impact of ambient UV-B radiation on the endemic bryophyte, Grimmia antarctici, was studied over 14 months in East Antarctica. Over recent decades, Antarctic plants have been exposed to the largest relative increase in UV-B exposure as a result of ozone depletion. We investigated the effect of reduced UV and visible radiation on the pigment concentrations, surface reflectance and physiological

Sharon A. Robinson; Johanna D. Turnbull; Catherine E. Lovelock

2005-01-01

193

Characteristics of Water Quali ty in Anchialine Po nds of the Kona, Hawaii, Coast . 1  

Microsoft Academic Search

A study of the water quality characteristics of anchialine ponds of the Kona, Hawaii, coast suggests that groundwater is a major source of dissolved nutrients for these systems. These groundwater sources apparently show high spatial and temporal variability with respect to dissolved nutrients. Changes are apparent in the water quality characteristics of one anchialine pond system that has been subjected

RICHARD E. BROCK; JAMES E. NORRIS; DAVID A. ZIEMANN; MICHAEL T. LEE

194

Physiological and behavioral consequences in rats of water recycling during lactation  

Microsoft Academic Search

Reports that radioactive water injected into 10-day-old Sprague-Dawley rats could be recovered the following day from their mothers' blood. This transfer of water was nearly eliminated by ligating the injected pups' urethras, a result indicating that mother rats consume their offspring's urine. Preventing urine consumption by ligating urethras of all pups in a litter doubled the plasma volume deficit in

Mark I. Friedman; John P. Bruno; Jeffrey R. Alberts

1981-01-01

195

Water Use Efficiency and Physiological Response of Rice Cultivars under Alternate Wetting and Drying Conditions  

PubMed Central

One of the technology options that can help farmers cope with water scarcity at the field level is alternate wetting and drying (AWD). Limited information is available on the varietal responses to nitrogen, AWD, and their interactions. Field experiments were conducted at the International Rice Research Institute (IRRI) farm in 2009 dry season (DS), 2009 wet season (WS), and 2010 DS to determine genotypic responses and water use efficiency of rice under two N rates and two water management treatments. Grain yield was not significantly different between AWD and continuous flooding (CF) across the three seasons. Interactive effects among variety, water management, and N rate were not significant. The high yield was attributed to the significantly higher grain weight, which in turn was due to slower grain filling and high leaf N at the later stage of grain filling of CF. AWD treatments accelerated the grain filling rate, shortened grain filling period, and enhanced whole plant senescence. Under normal dry-season conditions, such as 2010 DS, AWD reduced water input by 24.5% than CF; however, it decreased grain yield by 6.9% due to accelerated leaf senescence. The study indicates that proper water management greatly contributes to grain yield in the late stage of grain filling, and it is critical for safe AWD technology.

Zhang, Yunbo; Tang, Qiyuan; Peng, Shaobing; Xing, Danying; Qin, Jianquan; Laza, Rebecca C.; Punzalan, Bermenito R.

2012-01-01

196

Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures  

SciTech Connect

An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (H{sub 2}O{sub (l)}), and hydrogen peroxide (H{sub 2}O{sub 2}) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio ({phi}), and concentration of H{sub 2}O{sub 2} in H{sub 2}O{sub (l)} oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial pressure range of 0.24 to 12.4 MPa in argon, using average nAl particle diameters of 38 nm, {phi} from 0.5 to 1.3, and H{sub 2}O{sub 2} concentrations between 0 and 32% by mass. At a nominal pressure of 3.65 MPa, under stoichiometric conditions, mass-burning rates per unit area ranged between 6.93 g/cm{sup 2} s (0% H{sub 2}O{sub 2}) and 37.04 g/cm{sup 2} s (32% H{sub 2}O{sub 2}), which corresponded to linear burning rates of 9.58 and 58.2 cm/s, respectively. Burning rate pressure exponents of 0.44 and 0.38 were found for stoichiometric mixtures at room temperature containing 10 and 25% H{sub 2}O{sub 2}, respectively, up to 5 MPa. Burning rates are reduced above {proportional_to}5 MPa due to the pressurization of interstitial spaces of the packed reactant mixture with argon gas, diluting the fuel and oxidizer mixture. Mass burning rates were not measured above {proportional_to}32% H{sub 2}O{sub 2} due to an anomalous burning phenomena, which caused overpressurization within the quartz sample holder, leading to tube rupture. High-speed imaging displayed fingering or jetting ahead of the normal flame front. Localized pressure measurements were taken along the sample length, determining that the combustion process proceeded as a normal deflagration prior to tube rupture, without significant pressure buildup within the tube. In addition to burning rates, chemical efficiencies of the combustion reaction were determined to be within approximately 10% of the theoretical maximum under all conditions studied. (author)

Sabourin, J.L.; Yetter, R.A. [The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA 16801 (United States); Risha, G.A. [The Pennsylvania State University, Division of Business and Engineering, Altoona, PA 16601 (United States); Son, S.F. [Purdue University, School of Mechanical Engineering, West Lafayette, IN 47907 (United States); Tappan, B.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2008-08-15

197

Water hammer simulation by implicit method of characteristic  

Microsoft Academic Search

An Implicit Method of Characteristics is proposed in this paper to alleviate the shortcomings and limitations of the mostly used conventional Method of Characteristics (MOC). An element-wise definition is used for all the devices that may be used in a pipeline system and the corresponding equations are derived in an element-wise manner. The proper equations defining the behavior of each

M. H. Afshar; M. Rohani

2008-01-01

198

An epidemiologic study of the relationship between hepatitis A and water supply characteristics and treatment.  

PubMed Central

Outbreaks of hepatitis A (HA) attributable to water contamination have been reported; however, the impact of water supply characteristics on the endemic rates of HA has not been quantified. This study did not detect any statistically significant associations between endemic HA rates and water supply characteristics. Because of the sample size, this finding suggests that the total variation of HA rates attributable to water supply characteristics is probably less than 8 per cent of the annual reported cases of HA in the United States.

Batik, O; Craun, G F; Tuthill, R W; Kraemer, D F

1980-01-01

199

Flammability characteristics of sprays of water-based paints  

Microsoft Academic Search

Mainly in the car industry, many automatic electrostatic spraying installations are at present being converted to use water-based paints. This will involve considerable advantages in the field of fire and explosion protection, if the water-based paints used can be considered non flammable when sprayed. To investigate this question, the burning behaviour of more than 120 electrostatically sprayed water-based paints, which

Ulrich von Pidoll; Helmut Krämer

1997-01-01

200

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

SciTech Connect

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.

Corley, Rick A. (BATTELLE (PACIFIC NW LAB)); Gordon, Syd M. (Battelle Memorial Institute); Wallace, Lance A. (U.S. Environmental Protection Agency)

2000-01-14

201

Physiological and molecular mechanisms of salt and water homeostasis in the nematode Caenorhabditis elegans.  

PubMed

Intracellular salt and water homeostasis is essential for all cellular life. Extracellular salt and water homeostasis is also important for multicellular organisms. Many fundamental mechanisms of compensation for osmotic perturbations are well defined and conserved. Alternatively, molecular mechanisms of detecting salt and water imbalances and regulating compensatory responses are generally poorly defined for animals. Throughout the last century, researchers studying vertebrates and vertebrate cells made critical contributions to our understanding of osmoregulation, especially mechanisms of salt and water transport and organic osmolyte accumulation. Researchers have more recently started using invertebrate model organisms with defined genomes and well-established methods of genetic manipulation to begin defining the genes and integrated regulatory networks that respond to osmotic stress. The nematode Caenorhabditis elegans is well suited to these studies. Here, I introduce osmoregulatory mechanisms in this model, discuss experimental advantages and limitations, and review important findings. Key discoveries include defining genetic mechanisms of osmolarity sensing in neurons, identifying protein damage as a sensor and principle determinant of hypertonic stress resistance, and identification of a putative sensor for hypertonic stress associated with the extracellular matrix. Many of these processes and pathways are conserved and, therefore, provide new insights into salt and water homeostasis in other animals, including mammals. PMID:23739341

Choe, Keith P

2013-06-05

202

How do morphological characteristics of hillslope control water movement in the saturated and unsaturated zone?  

NASA Astrophysics Data System (ADS)

Prediction of vegetation effect on soil moisture is a central feature of soil vegetation models. At hillslope scale, soil moisture is controlled by land use, soil characteristics, topography, stream and groundwater proximity etc. This paper aims to evaluate the importance of morphological characteristics on spatial soil water storage variation and their effect on water movement at hillslope scale. Five hillslopes were selected according to a set of morphological characteristics i.e. hillslope length, slope, drainage area, degree of convexity and concavity, convergence criteria, stream order. Soil characteristics and moisture were measured. Morphological characteristics were extracted from high resolution LIDAR. A physically-based, finite element model using Richards equation for variably saturated flow was implemented. Simulations were carried out for five hillslopes to evaluate the effect of morphological characteristics. Model sensitivity to soil hydrodynamic properties as well as hillslope morphology criteria was analyzed. Results obtained show that a spatial organization trend of morphological characteristics, especially soil thickness and porosity varies with topography and defines soil water capacity which seems to be a major factor on water availability for root uptake. The relationship between soil characteristics, hillslope morphology and water storage variation is a key to understand groundwater recharge amount control. Our results suggests a new perspective for the main morphological characteristics to consider for water movement modeling.

Thomas, Z.; Bloux, A.; Hamon, Y.; Rouault, F.

2011-12-01

203

Diffusion characteristics of water vapor in some keratins  

Microsoft Academic Search

Summary A detailed examination of the diffusion behavior of water vapor in stratum corneum samples obtained from humans, guinea pig and neonatal rat, a well as in human air fibers, was carried out. It has been found that, as with most polymeric films above the glass transition temperature, diffusion of water vapor into stratum corneum and hair is characterized by

A. F. El-Shimi; H. M. Princen

1978-01-01

204

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)

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.

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

2003-12-01

205

EFFECTS OF WATER SALINITY ON GROWTH INDICES AND PHYSIOLOGICAL PARAMETERS IN SOME PISTACHIO ROOTSTOCKS  

Microsoft Academic Search

Pistachio is one of the most important horticultural crops in Iran. The majority of the pistachio producing regions is located in arid and semi-arid areas with saline conditions. Therefore, selection of suitable rootstocks is important for increasing yield efficiency of this important nut crop. In this study, the effect of four water salinity levels (0.75, 5, 10 and 15 ds

H. R. Karimi; A. Ebadi; Z. Zamani; R. Fatahi

2011-01-01

206

Studies on the Population Dynamics and Physiological Ecology of Four Species of Fresh-Water Isopods.  

National Technical Information Service (NTIS)

The comparative biology of four species of fresh-water isopods was investigated. Isopods are known to be part of the 'pollution fauna' that can inhabit badly polluted areas. The species studies inhabit a temporaty pond, a drainage ditch, a small permanent...

A. J. Seidenberg S. C. Kendeigh

1970-01-01

207

Isolating plant physiological responses to a changing climate of elevated temperatures and more variable water availability  

NASA Astrophysics Data System (ADS)

The semiarid southwest has and is predicted to continue to experience multiple concomitant changes in the coming decades. Climatic warming and more variable precipitation with long periods of drought are projected for the region. Vegetative change, through the widespread expansion of woody plants into grasslands, is also expected to continue. Due to differences in plant physiological responses to varying conditions of temperature and moisture availability, these climatic and vegetative shifts could mean big changes in how ecosystems sequester carbon dioxide (CO2) from or respire CO2 to our atmosphere. In this study, we compared photosynthetic rates of CO2 assimilation (A) in C3 woody mesquites and C4 grasses in response to a large rainfall event after a prolonged drought. Paired treatments were maintained at two temperatures differing by 4°C to provide insight into responses under current and expected future climate conditions. Preliminary results indicate greater A within grasses than mesquites at both dry and post-rainfall time points, suggesting a possible movement toward less carbon sequestration in the future under the influence of woody plant encroachment. Time to reach peak A after an initial rainfall event was greater in grasses demonstrating a difference in growth strategies for precipitation response. Furthermore, grasses tended to have higher optimum temperatures, but mesquites were able to maintain A across a broader range of temperatures under dry, drought conditions. The effects of deeper rooting and groundwater access in woody plants during longer drought periods could complicate these results and would warrant future study.

Sykora, K.; Barron-Gafford, G. A.

2011-12-01

208

Using soil freezing characteristics to model multi-season soil water dynamics  

Technology Transfer Automated Retrieval System (TEKTRAN)

The soil moisture characteristic relation is critical to accurately simulate soil water dynamics but is difficult and time consuming to measure, particularly for the dry regions of the curve. The relation between freezing soil temperatures, soil water potential and liquid water content, termed the ...

209

Desert shrub water relations with respect to soil characteristics and plant functional type  

Microsoft Academic Search

Summary 1. Soil characteristics influence plant communities in part through water relations. Hypothetically, finer textured soils in arid climates should be associated with more negative plant and soil water potentials during drought, greater resistance of xylem to cavitation, and shallower root systems than coarse soils. 2. These hypotheses were tested by comparing the water relations of Great Basin shrubs growing

J. S. Sperry; U. G. Hacke

2002-01-01

210

A physical–chemical model for the static water retention characteristic of unsaturated porous media  

Microsoft Academic Search

Water retention characteristic or water retention curve (WRC) is an important constitutive feature of porous media, and also meanwhile is an indispensable requirement in hydraulic transport modelling. Previous experiments have indicated that the specific surface area of porous media has effects on the WRC. It has also been observed that a linear relationship generally exists between the air–water interface area

Y. Wang; S. M. Grove; M. G. Anderson

2008-01-01

211

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

NASA Astrophysics Data System (ADS)

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 ?g/L), cadmium chloride (0.0002 and 0.002 ?g/L), and atrazine (150 ?g/L). In contrast, we observed a significant decrease in oxygen flux after exposures to potassium cyanide (5.2, 22, and 44 ?g/L) and atrazine (1500 ?g/L). No effects were detected after exposures to malathion (200 and 340 ?g/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.

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

2009-05-01

212

Physiological Effects of Kaolin Applications in Well-irrigated and Water-stressed Walnut and Almond Trees  

PubMed Central

• Background and Aims Kaolin applications have been used to mitigate the negative effects of water and heat stress on plant physiology and productivity with variable results, ranging from increased to decreased yields and photosynthetic rates. The mechanisms of action of kaolin applications are not clear: although the increased albedo reduces leaf temperature and the consequent heat stress, it also reduces the light available for photosynthesis, possibly offsetting benefits of lower temperature. The objective of this study was to investigate which of these effects are prevalent and under which conditions. • Methods A 6?% kaolin suspension was applied on well-irrigated and water-stressed walnut (Juglans regia) and almond (Prunus dulcis) trees. Water status (i.e. stem water potential, ?s), gas exchange (i.e. light-saturated CO2 assimilation rate, Amax; stomatal conductance, gs), leaf temperature (Tl) and physiological relationships in treated and control trees were then measured and compared. • Key Results In both species, kaolin did not affect the daily course of ?s whereas it reduced Amax by 1–4 ?mol CO2 m–2 s–1 throughout the day in all combinations of species and irrigation treatments. Kaolin did not reduce gs in any situation. Consequently, intercellular CO2 concentration (Ci) was always greater in treated trees than in controls, suggesting that the reduction of Amax with kaolin was not due to stomatal limitations. Kaolin reduced leaf temperature (Tl) by about 1–3?°C and leaf-to-air vapour pressure difference (VPDl) by about 0·1–0·7 kPa. Amax was lower at all values of gs, Tl and VPDl in kaolin-treated trees. Kaolin affected the photosynthetic response to the photosynthetically active radiation (PAR) in almond leaves: kaolin-coated leaves had similar dark respiration rates and light-saturated photosynthesis, but a higher light compensation point and lower apparent quantum yield, while the photosynthetic light-response curve saturated at higher PAR. When these parameters were used to model the photosynthetic response curve to PAR, it was estimated that the kaolin film allowed 63?% of the incident PAR to reach the leaf. • Conclusions The main effect of kaolin application was the reduction, albeit minor, of photosynthesis, which appeared to be related to the shading of the leaves. The reduction in Tl and VPDl with kaolin did not suffice to mitigate the adverse effects of heat and water stress on Amax.

ROSATI, A.; METCALF, S. G.; BUCHNER, R. P.; FULTON, A. E.; LAMPINEN, B. D.

2006-01-01

213

Experimental research on dynamic operating characteristics of a novel silica gel-water adsorption chiller  

Microsoft Academic Search

A novel silica gel-water adsorption chiller consisting of two adsorption\\/desorption chambers and an evaporator with one heat-pipe\\u000a working chamber is experimentally studied. The dynamic operating characteristics of the chiller and the thermodynamic characteristics\\u000a of the adsorber are obtained. The experimental results show that the dynamic operating characteristics of the chiller and\\u000a the thermodynamic characteristics of the adsorber are satisfactory and

Dechang Wang; Jingyi Wu; Ruzhu Wang; Weidong Dou

2007-01-01

214

The thermochemical characteristics of cellulose and its mixtures with water  

NASA Astrophysics Data System (ADS)

The heat capacity of cotton microcrystalline cellulose was measured on an adiabatic vacuum calorimeter over the temperature range 80-330 K, and the differential thermal analysis data on the substance were obtained from 80 to 550 K. The enthalpy of cellulose interaction with water was measured at 303 K using a differential microcalorimeter. The standard enthalpies of combustion and formation of microcrystalline cellulose and wood celluloses with different crystallinity indices were determined. The concentration of saturated water solution in microcrystalline cellulose at 273 K was determined calorimetrically from the enthalpy of fusion of the excess water phase.

Ur'yash, V. F.; Larina, V. N.; Kokurina, N. Yu.; Novoselova, N. V.

2010-06-01

215

Physiology of acidophilic bacteria of acid mine water. Completion report Jul 1969Aug 1970  

Microsoft Academic Search

Two new acidophilic bacteria (strains M-1 and M-2) were isolated from coal mine waters, characterized, and placed in the genus Pseudomonas, as Pseudomonas acidophila, sp. n. Obligate acidophiles unable to grow at neutrality, they are capable of rapid and vigorous growth at pH 3.5, with a range of pH 2.5-4.5, in an especially devised yeast extract-glucose salts medium. Unlike the

H. L. Manning; T. M. Cook

1972-01-01

216

Physiological parameters of plants as indicators of water quality in a constructed wetland  

Microsoft Academic Search

Introduction  Increasing demand for water has stimulated efforts to treat wastewater for reuse in agriculture. Decentralized facilities\\u000a for wastewater treatment became popular as a solution to remote and small communities. These systems mimic natural wetlands,\\u000a cleaning wastewater as they flow through a complex of filter media, microbial fauna, and vegetation. The function of plants\\u000a in constructed wetlands (CWs) has not been

Oren Shelef; Avi Golan-Goldhirsh; Tanya Gendler; Shimon Rachmilevitch

217

Physiological effects of dehydration and rehydration with water and acidic or neutral carbohydrate electrolyte solutions  

Microsoft Academic Search

Summary  Five healthy young men exercised on an ergocycle for six 25-min periods separated by 5-min rest intervals in a warm dry environment (36°C). After 1 h of exercise without fluid intake, the subjects continued to be dehydrated or were rehydrated either with water (W) or with isosmotic electrolyte carbohydrate solutions, either acidic (AISO) or close to neutrality (NISO). The average

B. Bothorel; M. Follenius; R. Gissinger; V. Candas

1990-01-01

218

Physiological Response of Daphnia magna to Linear Anionic Polyacrylamide: Ecological Implications for Receiving Waters  

Microsoft Academic Search

Linear anionic polyacrylamide (LA-PAM) is being considered as a soil amendment to reduce seepage and infiltration in unlined\\u000a earthen canals. While polyacrylamides have been extensively used for potable water treatment, dewatering sewage sludge, coal\\u000a and mine processing, paper manufacturing, and agriculture, little is known about its ecological impact to aquatic ecosystems.\\u000a Acute toxicity (LC50, 24 and 48 h) and chronic exposure

Kumud Acharya; Candi Schulman; Michael H. Young

2010-01-01

219

DEVELOPING JOINT PROBABILITY DISTRIBUTIONS OF SOIL WATER RETENTION CHARACTERISTICS  

EPA Science Inventory

A method is presented for developing probability density functions for parameters of soil moisture relationships of capillary head and hydraulic conductivity. These soil moisture parameters are required for the assessment of water flow and solute transport in unsaturated media. T...

220

Water Quality Characteristics and Performance of Compost Filter Berms.  

National Technical Information Service (NTIS)

The Texas Department of Transportation, in conjunction with the Texas Commission on Environmental Quality and the Environmental Protection Agency, commissioned a study to examine the water quality impacts of compost leachate constituents and structural in...

B. B. Storey A. B. R. Desai M. H. Li H. C. Landphair T. Kramer

2006-01-01

221

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 ...

222

Effect of Timber Harvest on Physical Water Quality Characteristics  

Microsoft Academic Search

The effect of 11% thinning on selected stream water properties in an oak-beech forest ecosystem in the Belgrad Forest of Istanbul,\\u000a Turkey was studied with a paired catchment experiment. Regression equations for some physical properties of the stream water\\u000a were developed between control (W-I) and treatment (W-II) watersheds for calibration (with their 95% confidence limits) and\\u000a treatment periods. The study

F. Gökbulak; Y. Serengil; S. Özhan; N. Özyuvac?; N. Balc?

2008-01-01

223

Soil and water characteristics of a young surface mine wetland  

Microsoft Academic Search

Coal companies are reluctant to include wetland development in reclamation plans partly due to a lack of information on the resulting characteristics of such sites. It is easier for coal companies to recreate terrestrial habitats than to attempt experimental methods and possibly face significant regulatory disapproval. Therefore, we studied a young (10 years) wetland on a reclaimed surface coal mine

C. Andrew Cole; Eugene A. Lefebvre

1991-01-01

224

Acoustical characteristics of leak signals in plastic water distribution pipes  

Microsoft Academic Search

Acoustical characteristics of leak signals in plastic pipes were investigated in this study for several types of leaks simulated under controlled conditions at an experimental site. The investigation included the characterization of frequency content of sound or vibration signals as a function of leak type, flow rate, pipe pressure and season, the determination of the attenuation rate, and the variation

Osama Hunaidi; Wing T. Chu

1999-01-01

225

Physico-chemical characteristics of water samples of Bantwal Taluk, south-western Karnataka, India.  

PubMed

Quality of water is an important criterion for evaluating the suitability of water for irrigation and drinking. In the present study the analysis of water samples from different sources like open wells, bore wells, farm ponds and streams/rivers of twenty villages of Bantwal taluk of Dakshina Kannada district, South-western Kamataka has been carried out. The physico-chemical characteristics of this water showed that it is suitable for irrigation and agricultural purposes. PMID:18380080

Smitha, P G; Byrappa, K; Ramaswamy, S N

2007-07-01

226

Characteristics of thermal conductivity in classical water models  

NASA Astrophysics Data System (ADS)

The thermal conductivities of common water models are compared using equilibrium (EMD) and non-equilibrium molecular dynamics (NEMD) simulation. A complete accounting for electrostatic contributions to the heat flux was found to resolve the previously reported differing results of NEMD and EMD Green-Kubo measurements for the extended simple point-charge (SPC/E) model. Accordingly, we demonstrate the influence of long-range electrostatics on the thermal conductivity with a simple coulomb cutoff, Ewald summation, and by an extended particle-particle particle-mesh method. For each water model, the thermal conductivity is computed and decomposed in terms of frequency-dependent thermodynamic and topological contributions. The rigid, three-site SPC, SPC/E, and transferable intermolecular potential (TIP3P-Ew) water models are shown to have similar thermal conductivity values at standard conditions, whereas models that include bond stretching and angle bending have higher thermal conductivities.

Sirk, Timothy W.; Moore, Stan; Brown, Eugene F.

2013-02-01

227

Characteristics of thermal conductivity in classical water models.  

PubMed

The thermal conductivities of common water models are compared using equilibrium (EMD) and non-equilibrium molecular dynamics (NEMD) simulation. A complete accounting for electrostatic contributions to the heat flux was found to resolve the previously reported differing results of NEMD and EMD Green-Kubo measurements for the extended simple point-charge (SPC/E) model. Accordingly, we demonstrate the influence of long-range electrostatics on the thermal conductivity with a simple coulomb cutoff, Ewald summation, and by an extended particle-particle particle-mesh method. For each water model, the thermal conductivity is computed and decomposed in terms of frequency-dependent thermodynamic and topological contributions. The rigid, three-site SPC, SPC/E, and transferable intermolecular potential (TIP3P-Ew) water models are shown to have similar thermal conductivity values at standard conditions, whereas models that include bond stretching and angle bending have higher thermal conductivities. PMID:23425477

Sirk, Timothy W; Moore, Stan; Brown, Eugene F

2013-02-14

228

Performance characteristics of a pulse combustion water heater  

Microsoft Academic Search

Work performed on an experimental pulse combustion water heater, as well as results obtained with the experimental system, are reported. Thermal, pressure, acoustical, and flow measurements were made during each test run. Data obtained from the thermal measurements were used to calculate the efficiency of the experimental system. The highest calculated efficiency value was 88 percent. The acoustical measurements indicated

S. T. Vogt; M. S. Yen; R. J. Schoenhals; W. Soedel; R. W. Herrick

1978-01-01

229

Water temperature characteristics of lakes subjected to climate change  

Microsoft Academic Search

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. Model coefficients related to hypolimnetic eddy diffusivity, light attenuation, wind sheltering, and convective heat transfer were generalized using theoretical and empirical extensions.

M. Hondzo; H. G. Stefan

1992-01-01

230

Soil and water characteristics of a young surface mine wetland  

Microsoft Academic Search

Coal companies are reluctant to include wetland development in reclamation plans partly due to a lack of information on the\\u000a resulting characteristics of such sites. It is easier for coal companies to recreate terrestrial habitats than to attempt\\u000a experimental methods and possibly face significant regulatory disapproval. Therefore, we studied a young (10 years) wetland\\u000a on a reclaimed surface coal mine

C. Andrew Cole; Eugene A. Lefebvre

1991-01-01

231

Kinetic Analysis of Human Enzyme RDH10 Defines the Characteristics of a Physiologically Relevant Retinol Dehydrogenase*S?  

PubMed Central

Human retinol dehydrogenase 10 (RDH10) was implicated in the oxidation of all-trans-retinol for biosynthesis of all-trans-retinoic acid, however, initial assays suggested that RDH10 prefers NADP+ as a cofactor, undermining its role as an oxidative enzyme. Here, we present evidence that RDH10 is, in fact, a strictly NAD+-dependent enzyme with multisubstrate specificity that recognizes cis-retinols as well as all-trans-retinol as substrates. RDH10 has a relatively high apparent Km value for NAD+ (?100 ?m) but the lowest apparent Km value for all-trans-retinol (?0.035 ?m) among all NAD+-dependent retinoid oxidoreductases. Due to its high affinity for all-trans-retinol, RDH10 exhibits a greater rate of retinol oxidation in the presence of cellular retinol-binding protein type I (CRBPI) than human microsomal RoDH4, but like RoDH4, RDH10 does not recognize retinol bound to CRBPI as a substrate. Consistent with its preference for NAD+, RDH10 functions exclusively in the oxidative direction in the cells, increasing the levels of retinaldehyde and retinoic acid. Targeted small interfering RNA-mediated silencing of endogenous RDH10 or RoDH4 expression in human cells results in a significant decrease in retinoic acid production from retinol, identifying both human enzymes as physiologically relevant retinol dehydrogenases. The dual cis/trans substrate specificity suggests a dual physiological role for RDH10: in the biosynthesis of 11-cis-retinaldehyde for vision as well as the biosynthesis of all-trans-retinoic acid for differentiation and development.

Belyaeva, Olga V.; Johnson, Mary P.; Kedishvili, Natalia Y.

2008-01-01

232

Stress-Corrosion Cracking Characteristics of Alloys of Titanium in Salt Water.  

National Technical Information Service (NTIS)

The salt water stress-corrosion cracking (SCC) characteristics have been determined for a large number of titanium alloys representatives of commercial production. These data were compiled as part of an NRL program directed to determining the underlying p...

R. W. Judy R. J. Goode

1967-01-01

233

Role of Soil Characteristics on Analysis of Water Flow in Shallow Land.  

National Technical Information Service (NTIS)

Analysis of water flow on posutulated model grounds has been carried out by using 2-dimensional finite element analytical model, to clarify the effects of soil characteristics (hydroulic conductivities in saturated and unsaturated zones, moisture content ...

T. Tohaya N. Wakabayashi Y. Wadachi

1987-01-01

234

Predicting the permeability function for unsaturated soils using the soil-water characteristic curve  

Microsoft Academic Search

The coefficient of permeability for an unsaturated soil is primarily determined by the pore-size distribution of the soil and can be predicted from the soil-water characteristic curve. A general equation, which describes the soil-water characteristic curve over the entire suction range (i.e., from 0 to 10 6 kPa), was proposed by the first two authors in another paper. This equation

D. G. Fredlund; ANQUING XING; Shangyan Huang

1994-01-01

235

Prediction of micro-bubble dissolution characteristics in water and seawater  

Microsoft Academic Search

This paper is concerned with the prediction of micro-bubble dissolution characteristics in water and seawater when microbubbles are generated by a Sadatomi-type micro-bubble generator (2003) with a spherical body in a flowing liquid tube. In the experiments, in order to know the effects of the salinity on the characteristics, tap water and an artificial seawater with different salt concentrations of

Akimaro Kawahara; Michio Sadatomi; Hidetoshi Matsuura; Mayo Tominaga; Masanori Noguchi; Fuminori Matsuyama

2009-01-01

236

Spouting characteristics of small glass particles with water  

Microsoft Academic Search

Experimental data are reported for the minimum spouting velocity, bed pressure drop, maximum spoutable height and spout diameter\\u000a which show that spouting of small particles with water represents a new spouting regime. The transition from large to small\\u000a particle spouting occurs when the voidage at the inlet to the spout goes from unity to less than unity.

Seung Jai Kim

1985-01-01

237

Biofouling characteristics and identification of preponderant bacteria at different nutrient levels in batch tests of a recirculating cooling water system.  

PubMed

Understanding the influence of nutrient levels on biofouling control is an important requirement for management strategies in a recirculating cooling water system. Nutrient limitation may be one way to control biofouling development without increasing biocide dosing. Therefore, this study was carried out to investigate the effects of nutrient levels on biofouling characteristics and to identify the preponderant bacteria in the batch tests with a simulated cooling water system. The biofouling characteristics were assessed by varying the biofoulant mass and the bacteria respiratory activity, which was estimated by measuring oxygen uptake rates. According to the results obtained in nutrient factor experiments, the biofouling could be better controlled at carbon, nitrogen and phosphorus concentrations of 30 mg N/L, 8 mg N/L and 1.0 mg P/L, respectively. Increasing carbon concentrations shortened the biofouling initial growth period and resulted in higher biofoulant mass. The preponderant bacteria strains involved in biofouling under two culture conditions were identified by applying both physiological and biochemical tests and further molecular biology techniques with phylogenetic affiliation analysis. Enterobacter (family Enterobacteriaceae), Staphylococcus (family Micrococcaceae), Bacillus (family Bacillaceae), Proteus (family Enterobacteriaceae), Neisseria (family Neisseriaceae) and Pseudomonas (family Pseudomonadaceae) were dominant in the conditions of lower carbon concentration (30 mg/L). Enterobacter are autotrophs, but the other five bacteria are all heterotrophs. In the conditions of higher carbon concentration (70 mg/L), Klebsiella (family Enterobacteriaceae), Enterobacter and Microbacterium (family Microbacteriaceae) were dominant; Enterobacter and Microbacterium are heterotrophs. PMID:21879565

Liu, Fang; Zhao, Chao-Cheng; Xia, Lu; Yang, Fei; Chang, Xin; Wang, Yong-Qiang

238

Functional Characteristics of Bacterioplankton with Reference to Its Aggregation in Water Bodies of Different Types  

Microsoft Academic Search

The functional characteristics of bacterioplankton have been studied with reference to its aggregation in water bodies of different types. Several methods were used for calculation of the total numbers of bacteria and proportion of aggregated cells. Analysis of the experimental data has shown a relationship between the functional characteristics of bacterioplankton, such as bacterial production, destruction of organic matter, and

L. A. Shchur; A. D. Aponasenko; V. N. Lopatin; G. V. Makarskaya

2002-01-01

239

Linking nutrient limitation and water chemistry in upland lakes to catchment characteristics  

Microsoft Academic Search

The relationship between catchment characteristics and lake water chemistry, phytoplankton and periphyton biomass, and phytoplankton and periphyton nutrient limitation was investigated for 30 upland lakes in the U.K. These catchment characteristics included the proportion of different land cover categories in the catchment and some hydrological information. Multiple regression models could predict alkalinity, pH, total dissolved phosphorus, dissolved inorganic nitrogen, dissolved

Stephen C. Maberly; Lydia King; Christopher E. Gibson; Linda May; Roger I. Jones; Mitzi M. Dent; Crawford Jordan

2003-01-01

240

Effects of Plant-Growth-Promoting Rhizobacteria on Yield, Growth, and Some Physiological Characteristics of Wheat and Barley Plants  

Microsoft Academic Search

In 2009 a greenhouse experiment was conducted to determine the effects of boron (B) and plant growth-promoting rhizobacteria (PGPR) treatments, applied either alone or in combination, on yield, plant growth, leaf total chlorophyll content, stomatal conductance, membrane leakage, and leaf relative water content of wheat (Triticum aestivum L. cv. Bezostiya) and barley (Hordeum vulgare L. cv. Tokak) plants. Results showed

Metin Turan; Medine Gulluce; Fikrettin ?ahin

2012-01-01

241

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

PubMed Central

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 ?-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.

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

2011-01-01

242

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

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.

Robinson, R.D. (Univ. of Guelph, Ontario (Canada). Dept. of Environmental Biology); Carey, J.H. (National Water Research Inst., Burlington, Ontario (Canada). Rivers Research Branch); Solomon, K.R. (Centre for Toxicology, Guelph, Ontario (Canada)); Smith, I.R. (Ontario Ministry of the Environment, Toronto, Ontario (Canada). Water Resources Branch); Servos, M.R.; Munkittrick, K.R. (Department of Fisheries and Oceans, Burlington, Ontario (Canada). Great Lakes Lab. for Fisheries and Aquatic Sciences)

1994-07-01

243

Psychological and physiological characteristics of a proposed object-referral/self-referral continuum of self-awareness.  

PubMed

This research extends and confirms recent brainwave findings that distinguished an individual's sense-of-self along an Object-referral/Self-referral Continuum of self-awareness. Subjects were interviewed and were given tests measuring inner/outer orientation, moral reasoning, anxiety, and personality. Scores on the psychological tests were factor analyzed. The first unrotated PCA component of the test scores yielded a "Consciousness Factor," analogous to the intelligence "g" factor, which accounted for over half of the variance among groups. Analysis of unstructured interviews of these subjects revealed fundamentally different descriptions of self-awareness. Individuals who described themselves in terms of concrete cognitive and behavioral processes (predominantly Object-referral mode) exhibited lower Consciousness Factor scores, lower frontal EEG coherence, lower alpha and higher gamma power during tasks, and less efficient cortical preparatory responses (contingent negative variation). In contrast, individuals who described themselves in terms of an abstract, independent sense-of-self underlying thought, feeling and action (predominantly Self-referral mode) exhibited higher Consciousness Factor scores, higher frontal coherence, higher alpha and lower gamma power during tasks, and more efficient cortical responses. These data suggest that definable states of brain activity and subjective experiences exist, in addition to waking, sleeping and dreaming, that may be operationally defined by psychological and physiological measures along a continuum of Object-referral/Self-referral Continuum of self-awareness. PMID:15134768

Travis, Frederick; Arenander, Alarik; DuBois, David

2004-06-01

244

Improved estimation of soil water retention characteristics from hydrostatic column experiments  

NASA Astrophysics Data System (ADS)

The soil water retention characteristic, ?(h), is required for modeling and predicting water and solute transport in unsaturated porous media. Commonly, ?(h) is determined by relating pressure heads, h, to mean water contents, ?, that are measured in column experiments under hydrostatic equilibrium conditions and fitting a parametric retention function to these data pairs. Implicit to this method is the assumption that the mean water content of the column is equivalent to a point measurement in the column center. Dependent on the nonlinearity of the vertical water content distribution, ?(z), in the column, this assumption may be invalid and introduces a systematic error. A sensitivity analysis shows that the magnitude of the error caused by neglecting the nonlinearity of the water content distribution may reach several percent if coarse materials with low air entry values and tall soil columns are investigated. Furthermore, neglecting ?(z) yields a smoothed retention characteristic and thus may lead to wrong conclusions about the most appropriate parametric model for the water retention characteristic. If the hydraulic conductivity function K(h) is predicted from such an incorrect retention function, it can differ greatly from the true function. In this paper, we propose to consider the measured water content of a soil column explicitly as an integral of the equilibrium water content distribution with depth. We show that this eliminates systematic parameter estimation errors and leads to improved estimates of the soil water retention function.

Peters, A.; Durner, W.

2006-11-01

245

Statistical characteristics of a water film falling down a flat plate at different inclinations and temperatures  

Microsoft Academic Search

In this work, the statistical characteristics of the surface of a water film, freely falling down a vertical or inclined flat plate, have been investigated. The study was carried out in the frame of a research on passive cooling of heated surfaces by the evaporation of thin water films. The experiments, performed to confirm and extend previous results by the

W. Ambrosini; N. Forgione; F. Oriolo

2002-01-01

246

Electrical and Radiation Characteristics of Water in the Decimeter and Meter Range.  

National Technical Information Service (NTIS)

An examination was made of the effect of the temperature and salinity of sea water on its dielectric constants and the radiation characteristics of a smooth water surface in the 10-200 cm wavelength range. With reference to the dependence of the dielectri...

V. Y. Rayzer Y. A. Sharkov V. S. Etkin

1974-01-01

247

Characteristics of melt water discharge in the Glacier No. 1 basin, headwater of Urumqi River  

NASA Astrophysics Data System (ADS)

Global warming has resulted in loss of mass and volume of most alpine glaciers.Mountain glacial runoff plays a critical role in the water cycle.The melt water discharge is indirectly affected by air temperature.This study mainly discusses the characteristics of the daily glacial runoff cycle.The monthly mean daytime discharge was generally greater than the nighttime discharge.

Mingjie, Gao; Tianding, Han; Baisheng, Ye; Keqin, Jiao

2013-05-01

248

Hydrogeochemical characteristics of some Cameroon bottled waters, investigated by multivariate statistical analyses  

Microsoft Academic Search

In this study, 8 bottled water brands sold in Cameroon were analyzed for 76 elements\\/parameters by ICP-MS, IC, titration and mass spectrometric methods. This was to investigate the geochemical characteristics of the bottled waters in order to identify the main hydro geochemical processes controlling their chemical content. A comparison of the element concentrations and the legal limits for both bottled

Stephanie Abonoje Oyebog; Andrew Ako Ako; George Elambo Nkeng; Emmanuel Cheo Suh

249

Water Accessibilities of Man-made Cellulosic Fibers – Effects of Fiber Characteristics  

Microsoft Academic Search

The dynamic vapor water sorption and desorption experiments were performed on cellulosic fibers with different characteristics. The hysteresis between moisture sorption and desorption cycle at 10% relative humidity (RH) was independent on the total moisture regain and approximately 45% for all materials except for viscose fibers. Brunauer–Emmett–Teller surface volume (Vm) for moisture sorption and retention capacity of liquid water (WRV)

Satoko Okubayashi; Ulrich J. Griesser; Thomas Bechtold

2005-01-01

250

A new Automated Laboratory Instrument for Soil Water Characteristic Determination. System Validation at Oregon State University  

Microsoft Academic Search

The soil water characteristic (SWC) is a fundamental descriptor of soil water retention properties. While tension table apparatus for defining drainage curves in the near-saturated region (0 to -100 cm H20) has been available for many decades, there has been little advance in automating the process, particularly when measurements of wetting, drying are combined. We describe a new automated tension

K. Vache; J. J. McDonneIl; C. Graham; J. Ekanayake; T. Davie

251

Scaling Soil Water Characteristics of Golf Course and Athletic Field Sands from Particle-Size Distribution  

Microsoft Academic Search

The soil water characteristic (SWC) of sands is an important hydraulic parameter in designing golf courses and athletic fi elds. A modifi ed version of the Arya-Paris model of the soil water character- istic was adapted to 14 golf course media that contained no to minor amounts of clay and silt. In this model, the particle-size distribution curve is divided

Lalit M. Arya; Daniel C. Bowman; Bir B. Thapa; D. Keith Cassel

2008-01-01

252

Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat ( Triticum aestivum L.) genotypes at tillering stage  

Microsoft Academic Search

Drought is one of the major ecological factors limiting crop production and food quality globally, especially in the arid and semi-arid areas of the world. Wheat is the staple food for more than 35% of world population and wheat cultivation is mainly restricted to such zones with scarcity of water, so wheat anti-drought physiology study is of importance to wheat

Hong-Bo Shao; Li-Ye Chu; Gang Wu; Jin-Heng Zhang; Zhao-Hua Lu; Ya-Chen Hu

2007-01-01

253

In vivo visualization of Tradescantia leaf tissue and monitoring the physiological and morphological states under different water supply conditions using optical coherence tomography  

Microsoft Academic Search

The optical coherence tomography (OCT) capabilities of plants were evaluated using leaves of Tradescantia pallida (Rose) D. Hunt. The internal structure of the leaf tissues was visualized in vivo and the physiological and morphological states of the tissues under different water supply conditions were monitored using OCT. The OCT technique provides non-invasive two-dimensional images directly on intact plants. The acquisition

Veronika V. Sapozhnikova; Vladislav A. Kamensky; Roman V. Kuranov; Irina Kutis; Ludmila B. Snopova; Aleksey V. Myakov

2004-01-01

254

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

Microsoft Academic Search

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

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

2003-01-01

255

Effect of temperature and chlorination of pre-washing water on shelf-life and physiological properties of ready-to-use iceberg lettuce  

Microsoft Academic Search

The effects of cold and warm, chlorinated water as well as warm water without chlorination for pre-washing trimmed, cored iceberg lettuce heads was assessed regarding the shelf-life and physiological properties of the resulting ready-to-use (RTU) produce. On a pilot-plant scale, lettuce heads were shredded with or without pre-washing (50 °C, no chlorine; 4 and 50 °C, 200 mg\\/l free chlorine;

Sascha Baur; Ralph Klaiber; Hua Wei; Walter Peter Hammes; Reinhold Carle

2005-01-01

256

Physiological and Biochemical Characteristics of Sugar Beet Plants Grown at an Increased Carbon Dioxide Concentration and at Various Nitrate Doses  

Microsoft Academic Search

Three-week-old sugar beet (Beta vulgaris L.) seedlings were grown for an additional four weeks under controlled conditions: in river sand watered with a modified Knop mixture containing one half-fold (0.5N), standard (1N), and or threefold (3N) nitrate amount, at the irradiance of 90 W\\/m2 PAR, and at the carbon dioxide concentrations of 0.035% (1C treatment) or 0.07% (2C treatment). The

A. K. Romanova; V. A. Mudrik; N. S. Novichkova; R. N. Demidova; V. A. Polyakova

2002-01-01

257

Explosion characteristics of intense femtosecond-laser-driven water droplets  

SciTech Connect

An efficient acceleration of energetic ions is observed when small heavy-water droplets of {approx}20 {mu}m diameter are exposed to ultrafast ({approx}40 fs) Ti:sapphire laser pulses of up to 10{sup 19} W/cm{sup 2} intensity. Quantitative measurements of deuteron and neutron spectra were done, allowing one to analyze the outward and inward directed deuteron acceleration from the droplet. Neutron spectroscopy based on the D(d,n) fusion reaction was accomplished in four different spatial directions. The energy shifts of those fusion neutrons produced inside the exploding droplet reflect a remaining deuteron acceleration inside the irradiated droplet along the axis of the incident laser beam. The overall neutron yield of the microdroplets is relatively small as a result of the dominant outward directed acceleration of the deuterons with 1200 neutrons/shot. Relying on the 'explosionlike' acceleration of such spherical droplet targets we have developed a spray target consisting of heavy-water microspheres with diameters of 150 nm. Both the high deuteron energies of up to 1 MeV resulting from the irradiation intensity of {approx}10{sup 19} W/cm{sup 2} as well as the collisions between the deuterons and the surrounding spray delivered about one order of magnitude more neutrons than the single-droplet system. The {approx}6x10{sup 3} neutrons per laser pulse from the spray can be attributed to an efficient deuteron release from a significantly smaller laser excited volume as from deuterium-cluster targets.

Schnuerer, M.; Ter-Avetisyan, S.; Busch, S.; Kalachnikov, M.; Stiel, H.; Nickles, P.V.; Sandner, W. [Max-Born-Institut, Max-Born-Strasse 2a, D-12489 Berlin (Germany); Hilscher, D.; Jahnke, U. [Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin (Germany)

2004-11-01

258

Explosion characteristics of intense femtosecond-laser-driven water droplets.  

PubMed

An efficient acceleration of energetic ions is observed when small heavy-water droplets of approximately 20 microm diameter are exposed to ultrafast (approximately 40 fs) Ti:sapphire laser pulses of up to 10(19) W/cm2 intensity. Quantitative measurements of deuteron and neutron spectra were done, allowing one to analyze the outward and inward directed deuteron acceleration from the droplet. Neutron spectroscopy based on the D (d,n) fusion reaction was accomplished in four different spatial directions. The energy shifts of those fusion neutrons produced inside the exploding droplet reflect a remaining deuteron acceleration inside the irradiated droplet along the axis of the incident laser beam. The overall neutron yield of the microdroplets is relatively small as a result of the dominant outward directed acceleration of the deuterons with 1200 neutrons/shot. Relying on the "explosion-like" acceleration of such spherical droplet targets we have developed a spray target consisting of heavy-water microspheres with diameters of 150 nm . Both the high deuteron energies of up to 1 MeV resulting from the irradiation intensity of approximately 10(19) W/cm2 as well as the collisions between the deuterons and the surrounding spray delivered about one order of magnitude more neutrons than the single-droplet system. The approximately 6 x 10(3) neutrons per laser pulse from the spray can be attributed to an efficient deuteron release from a significantly smaller laser excited volume as from deuterium-cluster targets. PMID:15600759

Schnürer, M; Hilscher, D; Jahnke, U; Ter-Avetisyan, S; Busch, S; Kalachnikov, M; Stiel, H; Nickles, P V; Sandner, W

2004-11-05

259

Biocenotic characteristics of some Yucatan lentic water bodies based on invertebrate remains in sediments  

Microsoft Academic Search

The Yucatan Peninsula is a karstic environment with almost no permanent surface water flows. All freshwater lentic systems\\u000a here are supported by underground water. We examined sediments, obtained with an Eckman dredge, from 25 different types of\\u000a water bodies (sinkholes or cenotes, lagoons, and wetlands), to investigate their biocenotic characteristics. All systems showed\\u000a differences in their zoocenoses, ostracods being the

N. N. Smirnov; M. Elías-Gutiérrez

2011-01-01

260

Constant Flow Method for Concurrently Measur- ing Soil-Water Characteristic Curve and Hydraulic Conductivity Function  

Microsoft Academic Search

A constant-flow laboratory testing method CFM is presented for concurrently measuring the soil-water characteristic curve SWCC and hydraulic conductivity function HCF of unsaturated coarse-grained soils. Two computer-automated syringe pumps are employed to control the volumetric water content of a specimen and to periodically impose constant volumetric flow rates through the specimen, respectively. Hydraulic conductivity k corresponding to each water content

Ning Lu; Alexandra Wayllace; Jiny Carrera; William J. Likos

261

Characteristics of the cold-water belt formed off Soya Warm Current  

Microsoft Academic Search

We examined the data obtained by acoustic Doppler current profiler, conductivity-temperature-depth profiler, and expendable bathythermograph observations, which were collected in the summers of 2000, 2001, and 2002, to clarify the characteristics of the cold-water belt (CWB), i.e., lower-temperature water than the surrounding water extending from the southwest coast of Sakhalin along the offshore side of Soya Warm Current (SWC) and

Miho Ishizu; Yujiro Kitade; Masaji Matsuyama

2008-01-01

262

Storage of oil field-produced waters alters their chemical and microbiological characteristics  

Microsoft Academic Search

Many oil fields are in remote locations, and the time required for shipment of produced water samples for microbiological\\u000a examination may be lengthy. No studies have reported on how storage of oil field waters can change their characteristics.\\u000a Produced water samples from three Alberta oil fields were collected in sterile, industry-approved 4-l epoxy-lined steel cans,\\u000a sealed with minimal headspace and

Jordan C. Hulecki; Julia M. Foght; Phillip M. Fedorak

2010-01-01

263

Polarization characteristics of coastal waters and their impact on in-water visibility  

NASA Astrophysics Data System (ADS)

Polarization characteristics of coastal waters were recently measured during a cruise on the R/V "Connecticut" in the areas of New York Harbor - Sandy Hook, NJ region using a new Stokes vector instrument developed by the Optical Remote Sensing Laboratory at CCNY. The instrument has three hyperspectral Satlantic radiance sensors each with a polarizer positioned in front of it, with polarization axes aligned at 0, 90 and 45°. The measured degrees of polarization (DOPs) and normalized radiances as a function of angle and wavelength match very well with simulated ones obtained with a Monte Carlo radiative transfer code for the atmosphere-ocean system. In order to numerically reproduce the polarized images for underwater horizontal imaging system the measured typical underwater polarized radiance was used to estimate the polarized components of the background veiling light and the blurring effects were modeled by point spread functions obtained from the measured volume scattering functions from this cruise and other typical oceanic environments. It is shown that the visibility can be improved for unpolarized target by placing a polarizer oriented orthogonally to the partially polarized direction of the veiling light before camera. The blurring effects strongly depend on the small angle scattering in the forward directions. For polarized targets the Monte Carlo simulation of slab geometry for polarized pencil light shows that the scattering medium with high g value has a very strong ability to retain the polarization status of the incident light, which can be utilized to improve the image contrasts for targets with very different polarized reflection properties.

Zhou, Jing; Tonizzo, Alberto; Gilerson, Alex; Twardowski, Michael; Gray, Deric; Weidemann, Alan; Arnone, Robert; Gross, Barry; Moshary, Fred; Ahmed, Sam

2009-05-01

264

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].  

PubMed

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media. PMID:16400989

Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

265

Study of water hammer due to a sudden steam bubble collapse using the characteristics method  

SciTech Connect

The water hammer phenomenon, due to a sudden collapsing of steam in a subcooled liquid, may affect the nuclear steam supply system in several adverse ways. The cumulative effects of steam condensation water hammer in steam generator feed lines can degrade the steam generator integrity. This type of water hammer event also occurs in the surge tank of boiling water reactors. Water hammer may also play a limiting role in the reactor vessel pressure during the reflood stages of a loss-of-coolant accident. For these reasons, water hammer continues to be a major issue in the nuclear power industry. It is, therefore, very desirable to demonstrate accurate means of calculating the time-dependent pressure due to water hammer. This study presents a numerical program developed for estimating the time-dependent pressure response to steam bubble collapse. The method of characteristics (MOC) is utilized to determine pressure propagation due to water hammer.

Davis, F.J. Jr.; Hassan, Y.A.

1987-01-01

266

Influence of water deprivation on water consumption, growth, and carcass characteristics of ducks.  

PubMed

Two-week-old White Pekin ducks were granted access to water either 4, 6, 8, 16, or 24 hr per day for a period of 4 weeks. The effects of water deprivation on water consumption, growth parameters, and carcass traits were determined. Compared to all other treatments, ducks allowed access to water for 4 hr per day had significantly lower (P less than .05) water intake, body weight, and feed consumption. Increasing water access time to either 6, 8, or 16 hr per day significantly increased (P less than .05) water consumption. Further significant increases in water consumption were not found when ducks were granted access to water for 24 hr per day. Prediction equations are presented for estimating daily intake of water for each treatment. There were no significant differences in final body weight or total feed consumption among ducks on the 6, 8, and 16 hr treatments. Overall feed conversion did not differ significantly among the treatments. No distinct relationship between length of water deprivation and yield of breast meat were observed. The advantages and disadvantages of limiting commercial ducks access to water for 8 hr per day in order to reduce water consumption are discussed. PMID:7301730

Veltmann, J R; Sharlin, J S

1981-03-01

267

Activation of renal calcium and water excretion by novel physiological and pharmacological activators of the calcium-sensing receptor.  

PubMed

Activated Ca(2+)-sensing receptors (CaR) play key roles in the regulation of whole-body calcium metabolism by inhibiting the secretion of the key calcitropic hormone parathyroid hormone and promoting urinary calcium excretion. We have now examined the effects of intravenous administration of novel calcium receptor activators on renal function in anaesthetized female Wistar rats. The type II calcimimetic NPS R-467 and the CaR-active amino acids l-Phe and l-Ala, which act at distinct binding sites on the receptor, all activated urinary flow rate, calcium and osmolar excretion and suppressed urinary osmolality. The effects of l-Phe and NPS R-467 on urine flow rate and calcium excretion were stereoselective, consistent with the idea that these effects were mediated by calcium-sensing receptors. However, d-Phe also suppressed urinary osmolality and promoted osmolar excretion, possibly by exceeding the transport maximum in the proximal tubule. The data indicate that novel activators of CaR, including l-amino acids at physiologically relevant serum concentrations, play a significant role in the regulation of urinary calcium and water excretion. PMID:15191415

Conigrave, Arthur D; Lok, Hiu Chuen

268

Comparison of leaf saturation isothermal remanent magnetisation (SIRM) with anatomical, morphological and physiological tree leaf characteristics for assessing urban habitat quality.  

PubMed

Leaf saturation isothermal remanent magnetisation (SIRM) is known as a good proxy of atmospheric, traffic related particulate matter (PM) concentration. In this study, we compared leaf SIRM with Leaf area (LA), leaf dry weight (LDW), specific leaf area (SLA), stomatal density (SD), relative chlorophyll content (RCC), chlorophyll fluorescence parameters (Fv/Fm and PI) for three urban tree types in the city of Ghent, Belgium. A negative significant relationship of LA, LDW and Fv/Fm, and a positive significant relationship of SLA with leaf SIRM was observed. Among all considered parameters, leaf SIRM had the highest potential for discrimination between contrasting land use classes. It was concluded that urban habitat quality can be monitored with leaf SIRM, independent of the other above mentioned plant parameters. The anatomical, morphological and physiological tree leaf characteristics considered are not good indicators for atmospheric PM, but might be interesting bio-indicators of other air pollutants than PM. PMID:23266296

Kardel, Fatemeh; Wuyts, Karen; Khavaninzhadeh, Ali Reza; Wuytack, Tatiana; Babanezhad, Manoochehr; Samson, Roeland

2012-12-23

269

Statistical Analysis of Drinking Water Treatment Plant Costs, Source Water Quality, and Land Cover Characteristics  

Microsoft Academic Search

Revisiting an earlier study conducted by The Trust for Public Land in 2004, this research brings new data and methodologies to offer insight on the impact of the decline of forest cover and the increase of agriculture or urban land cover in a drinking water source drainage area on the water quality for that drinking water source and the drinking

Jade Freeman; Rebecca Madsen; Kelley Hart; Paul Barten; Paul Gregory; David Reckhow; Woody Duncan

270

Investigation on dynamic changes of photosynthetic characteristics of 10 wheat (Triticum aestivum L.) genotypes during two vegetative-growth stages at water deficits.  

PubMed

Drought is a worldwide problem, seriously influencing plant (crop) productivity. Wheat is a stable food for 35% of the world population, and moreover, about 60% of land area on the globe belongs to arid and semiarid zone. Wheat drought resistance is a multi-gene controlling quantitative character and wheat final production in field is realized mainly by physiological regulation under the condition of multi-environmental factor interaction. Exploring drought resistance physiological mechanisms for different wheat genotypes is of importance to finding new drought resistance gene resources and conventional breeding, and the basis for wheat drought resistance biotechnological breeding and platform. Photosynthesis is the main component for physiological machinery of wheat assimilates conversion and wheat production. Investigation on photosynthetic characteristics of different wheat genotypes at soil water deficits also has other implications for refine physiological regulation of photosynthesis in fields and field management of crops in arid and semiarid areas. By pot-cultivating experiments, investigation of photosynthesis for 10 wheat genotypes at seedling stage and tillering stage at soil water deficits (75%FC, 55%FC and 45%FC, respectively) was conducted. The main results were as followed: developmental stages influenced wheat photosynthesis greatly and tillering stage played more roles; there were significant difference in the main photosynthetic parameters, photosynthesis rate (Photo), stomatal conductance (Cond) and transpiration rate (Tr), among 10 wheat genotypes; general photosynthesis and drought resistance in different wheat genotypes was related much to their domesticated origin soil water environment and selected generations and there was a photosynthetic threshold effect in terms of different wheat genotypes at soil water deficits. PMID:15975772

Hongbo, Shao; Zongsuo, Liang; Mingan, Shao; Shimeng, Sun; Zanmin, Hu

2005-07-10

271

The influence of fine water mist on characteristics of small-scale fire  

NASA Astrophysics Data System (ADS)

Water mist is used as an efficient extinguishing media instead of banned halogen-based fire extinguishing agent. Experiment was conducted to study the interaction of fine water mist and a small-scale fire. This fine water mist serves as candidate agent of fire protection system for electronic equipment fire. The characteristics of the fine water mist was obtained by three-dimensional laser Doppler velocimetry (LDV) / adaptive phase velocimetry (APV). Two kinds of fine water mist with equal mean droplet size, different velocity and caliber of mist jet were used to suppress a small-scale fire. A temperature measurement system based on micro-thermocouples was used to record temperature variation of the fire during exertion of fine water mist. A laser Moire deflectometry system displayed the flame pattern. Serial photographs of fire suppression process were present in this paper. The result shows fine water mist offers an enhanced cooling performance on the surrounding of fire flame.

Xu, Qiang; Qin, Jun; Liao, Guangxuan

2003-04-01

272

Determination of characteristics and drinking water quality index in Mzuzu City, Northern Malawi  

NASA Astrophysics Data System (ADS)

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.

Wanda, Elijah M. M.; Gulula, Lewis C.; Phiri, Gift

273

Preparation characteristics of water-in-oil-in-water multiple emulsions using microchannel emulsification  

Microsoft Academic Search

Microchannel (MC) emulsification is a novel technique for preparing monodispersed emulsions. This study demonstrates preparing water-in-oil-in-water (W\\/O\\/W) emulsions using MC emulsification. The W\\/O\\/W emulsions were prepared by a two-step emulsification process employing MC emulsification as the second step. We investigated the behavior of internal water droplets penetrating the MCs. Using decane, ethyl oleate, and medium-chain triglyceride (MCT) as oil phases,

Shinji Sugiura; Mitsutoshi Nakajima; Koji Yamamoto; Satoshi Iwamoto; Tatsuya Oda; Mitsuo Satake; Minoru Seki

2004-01-01

274

Chemical characteristics of fulvic acids from Arctic surface waters: Microbial contributions and photochemical transformations  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) originating from the extensive Arctic tundra is an important source of organic material to the Arctic Ocean. Chemical characteristics of whole water dissolved organic matter (DOM) and the fulvic acid fraction of DOM were studied from nine surface waters in the Arctic region of Alaska to gain insight into the extent of microbial and photochemical transformation of this DOM. All the fulvic acids had a strong terrestrial/higher plant signature, with uniformly depleted ?13C values of -28‰, and low fluorescence indices around 1.3. Several of the measured chemical characteristics of the Arctic fulvic acids were related to water residence time, a measure of environmental exposure to sunlight and microbial activity. For example, fulvic acids from Arctic streams had higher aromatic contents, higher specific absorbance values, lower nitrogen content, lower amino acid-like fluorescence and were more depleted in ?15N relative to fulvic acids isolated from lake and coastal surface waters. The differences in the nitrogen signature between the lake and coastal fulvic acids compared to the stream fulvic acids indicated that microbial contributions to the fulvic acid pool increased with increasing water residence time. The photo-lability of the fulvic acids was positively correlated with water residence time, suggesting that the fulvic acids isolated from source waters with larger water residence times (i.e., lakes and coastal waters) have experienced greater photochemical degradation than the stream fulvic acids. In addition, many of the initial differences in fulvic acid chemical characteristics across the gradient of water residence times were consistent with changes observed in fulvic acid photolysis experiments. Taken together, results from this study suggest that photochemical processes predominantly control the chemical character of fulvic acids in Arctic surface waters. Our findings show that hydrologic transport in addition to biogeochemical alteration of the organic matter must be considered in order to predict the ultimate fate of Arctic DOM.

Cory, Rose M.; McKnight, Diane M.; Chin, Yu-Ping; Miller, Penney; Jaros, Chris L.

2007-12-01

275

Effect of Bedrock infiltration on water balance and rainfall-runoff characteristics in forested headwater catchments  

NASA Astrophysics Data System (ADS)

Water flowing through bedrock plays an important role in stream water runoff generation and the variability in stream water runoff responses in headwater catchments. However, quantification of the contribution of bedrock infiltration to the water balance and runoff generation has been hindered by the difficulty of directly observing bedrock infiltration. To examine the role of bedrock infiltration in the water balance and runoff characteristics in forested headwater catchments, we quantified bedrock infiltration rates using the chloride mass balance method based on rigorous observations of catchment precipitation, discharge, and stream water chemistry in three forested catchments (second- to third-order catchments) underlain by uniform bedrock. We found that bedrock infiltration in forested headwater catchments can be estimated by the chloride mass balance method and that the three catchments differed greatly in terms of bedrock infiltration/recharge and runoff characteristics. In smaller catchments, bedrock recharge/infiltration varied widely, while small bedrock recharge/infiltration was observed in the largest catchment. Although runoff responses differed among the three catchments during base flow, no significant differences were observed in direct runoff ratio and peak flow during large storm events. These results suggest that variability in bedrock infiltration causes spatial variation in water balance and runoff characteristics during low flow, and has a small influence on during high flow in second- to third-order headwater catchments.

Oda, T.; Egusa, T.; Suzuki, M.

2011-12-01

276

The physiological role of atrial natriuretic hormone in the regulation of aldosterone and salt and water metabolism.  

PubMed

To investigate the mechanisms by which small changes in plasma levels of atrial natriuretic hormone (ANH) affect aldosterone, 10 normal young men were infused for 2 h with 0.6 pmol/kg.min human [Ser,Tyr28]ANH under 3 study conditions: 1) high salt diet (H), 2) low salt diet (L), and 3) low salt diet plus pretreatment with the angiotensin-converting enzyme inhibitor enalapril (LE). Baseline ANH levels were higher on H than on L or LE. A postural drop in ANH was observed when subjects went from standing to sitting. Plasma ANH levels increased during infusion by up to 4.5 pmol/L (H, 7.0 +/- 1.3 to 11.5 +/- 1.4; L, 4.3 +/- 0.6 to 8.7 +/- 1.1; LE, 4.2 +/- 0.5 to 8.6 +/- 1.5). At all time points, plasma ANH was well within the normal range. Plasma aldosterone did not change during H, decreased by about 60% for both low salt conditions, and remained suppressed at 1 h of recovery for L, but not for LE. This suggests that ANH can suppress aldosterone by both indirect and direct mechanisms, although the indirect mechanism appears to predominate. A prompt increase in urine flow was seen during ANH infusion and was sustained at 1 h of recovery, but little change was seen in urinary sodium or potassium excretion, heart rate, or blood pressure. The difference between the natriuretic and diuretic effects of ANH was seen under all conditions. These results support the hypothesis that within the normal physiological range, ANH is a regulator of salt and water metabolism in normal man. PMID:2137830

Clinkingbeard, C; Sessions, C; Shenker, Y

1990-03-01

277

A characteristic-Galerkin approximation to a system of shallow water equations  

Microsoft Academic Search

  \\u000a \\u000a \\u000a Summary. Characteristic methods are known to handle advective flow better than traditional Galerkin methods and allow large time steps\\u000a to be taken when compared to standard time-stepping methods. In this paper, we investigate a characteristic-Galerkin approximation\\u000a to the 2-dimensional system of shallow water equations. We derive bounds for elevation and velocity, showing these to be optimal for velocity in

Clint N. Dawson; Mónica L. Martínez-Canales

2000-01-01

278

Physical characteristics of GE (General Electric) BWR (boiling-water reactor) fuel assemblies  

SciTech Connect

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.

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

1989-06-01

279

Injection characteristics of coal-water slurries in medium-speed diesel equipment  

Microsoft Academic Search

This paper reports on the injection characteristics of several micronized coal-water slurries (CWSs, where s implies plural) which were investigated at high injection pressures (40 to 140 MPa, or 6,000 to 20,000 psi). Detailed spray characteristics including drop-size distributions and cone angles were measured using a continuous, high-pressure injection system spraying through various hole shapes and sizes into a continuous,

L. G. Dodge; T. J. Callahan; T. W. Ryan; J. A. Schwalb; C. E. Benson; R. P. Jr. Wilson

1992-01-01

280

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

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

Andrews, Shilo F; Flanagan, Lawrence B; Sharp, Eric J; Cai, Tiebo

2012-02-08

281

Selected water-quality characteristics in the upper Mississippi River Basin, Royalton to Hastings, Minnesota. Water resources investigation  

SciTech Connect

In recent years, great emphasis has been placed on protection and conservation of water resources. In response to these needs, the U.S. Geological Survey established a monitoring network called NASQAN (National Stream Quality Accounting Network) in 1973. One of the objectives of NASQAN is to describe the areal variability in the quality of water in the nation's streams through analysis of data from this and other programs. With computerized statistical-analysis techniques available today, it is possible to analyze large quantities of data to aid in interpreting and in making decisions. The report has the following primary objectives: describe, on both a spatial and temporal basis, the stream-water quality throughout the study area upstream from the NASQAN site, Mississippi River at Nininger, Minnestoa; relate water-quality variability to general causes, such as selected basin characteristics, including land and water use; and assess how well water-quality data collected at Nininger represent the quality of water throughout the study area. In addressing the above objectives, the report first discusses the water quality in each subbasin, then examines the differences between subbasins, and then evaluates the representativeness of data collected at Nininger.

Have, M.R.

1991-01-01

282

Static Characteristics of Absorption Chiller-Heater Supplying Cold and Hot Water Simultaneously  

NASA Astrophysics Data System (ADS)

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.

Inoue, Naoyuki; Irie, Tomoyoshi

283

Chemical and physical characteristics of natural ground waters in Michigan; a preliminary report  

USGS Publications Warehouse

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)

Cummings, T. Ray

1980-01-01

284

Statistical assessment of soil-water characteristic curve models for geotechnical engineering  

Microsoft Academic Search

A number of empirical equations have been proposed for the soil-water characteristic curve. A nonlinear, least squares method was used to determine best-fit parameters for several empirical equations that were best-fit to 230 water content versus soil suction data sets. In addition, two proposed correction methods to accommodate high soil suctions up to 1 000 000 kPa were applied to

W. Scott Sillers; Delwyn G. Fredlund

2001-01-01

285

Characteristics and spatio-temporal variability of the Amazon River Basin Water Budget  

Microsoft Academic Search

The spatio-temporal variations of the water budget components in the Amazon region are investigated by using a combination of hydrometeorological observations and moisture fluxes derived from the NCEP\\/NCAR reanalyses, for the period 1970–1999. The key new finding of this study identifies the major differences in the water balance characteristics and variability between the northern and southern parts of the basin.

Jose A. Marengo

2005-01-01

286

Experimental investigation of the silica gel–water adsorption isotherm characteristics  

Microsoft Academic Search

In designing adsorption chillers that employs silica gel–water as adsorbent-adsorbate pair, the overriding objective is to exploit low temperature waste-heat sources from industry. This paper describes an experimental approach for the determination of thermodynamic characteristics of silica gel–water working pair that is essential for the sizing of adsorption chillers. The experiments incorporated the moisture balance technique, a control-volume-variable-pressure (CVVP) apparatus

K. C. Ng; H. T. Chua; C. Y. Chung; C. H. Loke; T. Kashiwagi; A. Akisawa; B. B. Saha

2001-01-01

287

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

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

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

2013-09-25

288

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

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.

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

2013-01-01

289

Physiological responses of a cold-water shrimp, Pandalus borealis to bacterial lipopolysaccharide and synthetic double-stranded RNA, poly I:C  

Microsoft Academic Search

The effects of two pathogen-associated molecular patterns (PAMPs), namely, bacterial lipopolysaccharide (LPS) and double-stranded RNA, poly I:C on selected physiological response parameters in the hemolymph of a cold-water shrimp, Pandalus borealis were studied. Most of the tested immune factors were affected after intramuscular injection with the PAMPs. Total protein concentration in the hemolymph was significantly upregulated upon injection with the

Christopher Marlowe A. Caipang; Amod Kulkarni; Viswanath Kiron

290

Hydrochemical characteristics of mine waters from abandoned mining sites in Serbia and their impact on surface water quality.  

PubMed

Upon completion of exploration and extraction of mineral resources, many mining sites have been abandoned without previously putting environmental protection measures in place. As a consequence, mine waters originating from such sites are discharged freely into surface water. Regional scale analyses were conducted to determine the hydrochemical characteristics of mine waters from abandoned sites featuring metal (Cu, Pb-Zn, Au, Fe, Sb, Mo, Bi, Hg) deposits, non-metallic minerals (coal, Mg, F, B) and uranium. The study included 80 mine water samples from 59 abandoned mining sites. Their cation composition was dominated by Ca(2+), while the most common anions were found to be SO4 (2-) and HCO3 (-). Strong correlations were established between the pH level and metal (Fe, Mn, Zn, Cu) concentrations in the mine waters. Hierarchical cluster analysis was applied to parameters generally indicative of pollution, such as pH, TDS, SO4 (2-), Fe total, and As total. Following this approach, mine water samples were grouped into three main clusters and six subclusters, depending on their potential environmental impact. Principal component analysis was used to group together variables that share the same variance. The extracted principal components indicated that sulfide oxidation and weathering of silicate and carbonate rocks were the primary processes, while pH buffering, adsorption and ion exchange were secondary drivers of the chemical composition of the analyzed mine waters. Surface waters, which received the mine waters, were examined. Analysis showed increases of sulfate and metal concentrations and general degradation of surface water quality. PMID:23872888

Atanackovi?, Nebojša; Dragiši?, Veselin; Stojkovi?, Jana; Papi?, Petar; Zivanovi?, Vladimir

2013-07-20

291

CONNECTING WATERSHED CHARACTERISTICS TO NUTRIENT REGIME FROM HEADWATERS TO RECEIVING WATERS IN THE LAURENTIAL GREAT LAKES  

EPA Science Inventory

We are evaluating the influence of position along the tributary-coastal wetland-lake continuum on the expression of watershed characteristics in the water quality of Great Lakes (GL) coastal ecosystems as part of an EPA study focused on determining stressor-response relationships...

292

Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena  

Microsoft Academic Search

This paper considers the emission of infrared characteristic radiation during the first order phase transitions of water (condensation and crystallization). Experimental results are analyzed in terms of their correspondence to the theoretical models. These models are based on the assumption that the particle's (atom, molecule, or cluster) transition from the higher energetic level (vapor or liquid) to a lower one

Vitali A. Tatartchenko

2010-01-01

293

Characteristics of Significant Wave Height in China Seas and their Adjacent Waters from Merged Altimetry Data  

Microsoft Academic Search

Significant wave height (SWH) data from T\\/P, GFO, Jason-1 and Envisat altimeters are merged. The characteristics of SWH, such as the distributions of season average SWH, the probability distributions of different sea scales and the distributions of extreme SWH in 50 and 100 return years for China Seas and their adjacent waters are analyzed based on the merged data.

Jingsong Yang; Xiaoyan Chen; Rong Zhang; Juan Wang; Weigen Huang

2009-01-01

294

Shirnkage and water retention characteristic in a fine-textured mollisol compacted under different axle loads  

Microsoft Academic Search

In areas where heavy vehicles are used, the subsoils often become very compacted. Freezing-thawing and wetting-drying have not been effective at reducing compaction. In this study, the type of soil shrinkage related to compaction was investigated to explain these amelioration failures. In conjunction with a shrinkage curve, the water retention characteristic was also measured because both can be related to

L. Wu; R. R. Allmaras; D. Gimenez; D. M. Huggins

1997-01-01

295

Numerical simulation and optimization on valve-induced water hammer characteristics for parallel pump feedwater system  

Microsoft Academic Search

In this study, the method of characteristic line (MOC) was adopted to evaluate the valve-induced water hammer phenomena in a parallel pumps feedwater system (PPFS) during the alternate startup process of parallel pumps. Based on closed physical and mathematical equations supplied with reasonable boundary conditions, a code was developed to compute the transient phenomena including the pressure wave vibration, local

Wenxi Tian; G. H. Su; Gaopeng Wang; Suizheng Qiu; Zejun Xiao

2008-01-01

296

Leak-Free Pressure Plate Extractor For Measuring the Soil Water Characteristic Curve  

Microsoft Academic Search

An ew pressure plate extractor, referred to as the leak-free pressure plate extractor (LFPPE), is described where air leakage around the ceramic plate effectively is eliminated. The LFPPE was designed so that it would be robust, easy to use, and readily assembled and disassembled for testing and maintenance. An example shows that the LFPPE yields a soil water characteristic curve

Xiaodong Wang; Craig H. Benson; X Wang

2004-01-01

297

Relationship between porosimetry measurement and soil–water characteristic curve for an unsaturated residual soil  

Microsoft Academic Search

Soil–water characteristic curve (SWCC) is an important tool for determining the engineering properties of unsaturated soil. This depends on the size and distribution of pore structures which control the permeability and amount of volume change. Mercury Intrusion Porosimetry tests can be used to determine the size, amount and distribution of pore spaces of the soil in a shorter time period

K. K. Aung; H. Rahardjo; E. C. Leong; D. G. Toll

2001-01-01

298

Fouling characteristics and cleaning strategies in a coagulation-microfiltration combination process for water purification  

Microsoft Academic Search

The membrane fouling characteristics and cleaning strategies in a coagulation-microfiltration combination process for purification of micro-polluted raw water were investigated. The microcosmic observation on the exterior and inner surfaces of the fouled membrane by Scanning Electronic Microscope (SEM) combined. with Energy Dispersive Spectrometer (EDS) revealed that the fouling on the exterior surface was an integrated effect of microorganisms, organic and

Li Mo; Xia Huanga

2003-01-01

299

Evaporative heat transfer characteristics of a water spray on micro-structured silicon surfaces  

Microsoft Academic Search

Experiments were performed to evaluate the evaporative heat transfer characteristics of spray cooling of water on plain and micro-structured silicon surfaces at very low spray mass fluxes. The textured surface is made of an array of square micro-studs. It was found that the Bond number of the microstructures is the primary factor responsible for the heat transfer enhancement of evaporative

Cheng-Chieh Hsieh; Shi-Chune Yao

2006-01-01

300

Variation and prediction of membrane fouling index under various feed water characteristics  

Microsoft Academic Search

Membrane fouling index such as silt density index (SDI) and modified fouling index (MFI) is an important parameter in design of the integrated RO (reverse osmosis) and NF (nanofiltration) membrane processes for drinking water treatment. In this study, the effect of various foulant characteristics on membrane fouling index was investigated systematically. As expected, the fouling index (both SDI and MFI)

Hana Kim; Seungkwan Hong; Suing-Il Choi

2006-01-01

301

Characteristics of road deicers produced from the utilization of water plant residuals and cement wastes  

Microsoft Academic Search

This paper examines the use of water plant sludge and cement wastes in the production of the CMA deicer. Experiments were conducted in a temperature controlled test chamber, to determine melting rates and ice penetration characteristics of these deicers at two sub?zero temperatures. The freezer section of the refrigerator was modified and equipped with a temperature control mechanism to meet

A. P. Mathews; C. H. Choi; S. Dwyer

1996-01-01

302

Aquifer characteristics and water quality of Miocene–Pleistocene sediments, Kuwait  

Microsoft Academic Search

Al-Atraf is one of the water well fields of Kuwait supplying Kuwait City with the brackish groundwater obtained from the Kuwait Group aquifer of Miocene–Pleistocene age. The study determined the hydrogeological and hydrochemical characteristics of the groundwater in order to identify the major chemical processes that influence the groundwater quality of the study area. The results of the aquifer test

F. M. Al-Ruwaih; H. A. Qabazard

2005-01-01

303

Thermal-Hydraulic Characteristics of Double Flat Core HCLWR (High Conversion Light Water Reactor).  

National Technical Information Service (NTIS)

A thermal-hydraulic characteristics of double flat core high conversion light water reactor (HCLWR) is described. The concept of flat core proposed by Ishiguro et al. is to achieve negative void reactivity coefficient in tight lattice core, and at the sam...

J. Sugimoto T. Iwamura T. Okubo Y. Murao

1989-01-01

304

Comparison of selected cultural, physical, and water-quality characteristics of lakes in Washington  

USGS Publications Warehouse

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)

Bortleson, Gilbert Carl; Dion, N. P.

1979-01-01

305

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)

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 (?x), 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.

Stagakis, S.; González-Dugo, V.; Cid, P.; Guillén-Climent, M. L.; Zarco-Tejada, P. J.

2012-07-01

306

Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods  

PubMed Central

This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 ?L/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 ?L/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 ?L/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell’s cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.

Souza, E.L.; Oliveira, C.E.V.; Stamford, T.L.M.; Conceicao, M.L.; Neto, N.J. Gomes

2013-01-01

307

The Relationship between Phytoplankton Distribution and Water Column Characteristics in North West European Shelf Sea Waters  

PubMed Central

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.

Davidson, Keith; Bolch, Christopher J. S.; Brand, Tim D.; Narayanaswamy, Bhavani E.

2012-01-01

308

Interactive effect of Brevibacillus brevis and Glomus mosseae, both isolated from Cd contaminated soil, on plant growth, physiological mycorrhizal fungal characteristics and soil enzymatic activities in Cd polluted soil  

Microsoft Academic Search

The interaction between two autochthonous microorganisms (Brevibacillus brevis and Glomus mosseae) isolated from Cd amended soil increased plant growth, arbuscular mycorrhizal (AM) colonization and physiological characteristics of the AM infection (measured as SDH or ALP activities). The enhanced plant Cd tolerance after coinoculation with native microorganisms seemed to be a consequence of increased P and K acquisition and, simultaneously, of

A. Vivas; J. M. Barea; R. Azcón

2005-01-01

309

Global Modeling of Land Water and Energy Balances. Part II: Land-Characteristic Contributions to Spatial Variability  

Microsoft Academic Search

Land water and energy balances vary around the globe because of variations in amount and temporal distri- bution of water and energy supplies and because of variations in land characteristics. The former control (water and energy supplies) explains much more variance in water and energy balances than the latter (land charac- teristics). A largely untested hypothesis underlying most global models

P. C. D. Milly; A. B. Shmakin

2002-01-01

310

Separation of oil from bilge water I. Bilge water characteristics and the interaction of bilge water with chemically modified surfaces. Interim report, October 1994September 1995  

Microsoft Academic Search

We report on the results of a project using surface characterization and novel surface-modification techniques to address the issues of developing a minimally fouling ceramic membrane filter. We have studied the physical characteristics of a synthetic bilge water mixture, examined the surfaces of the ceramic filters for evidence of fouling, and identified several surface modifications that, under laboratory conditions, work

E. L. Chang; J. M. Calvert; T. Koloski; R. Price; B. Ratna

1997-01-01

311

Effect of seedling age and water depth on morphological and physiological aspects of transplanted rice under high temperature  

Microsoft Academic Search

To study the effect of high temperature, rice seedlings 20, 30, 40 and 50 d were kept at 5, 10, 15 and 20 cm water depth in a water pool. Meteorological findings indicated that water temperature varied up to 10 cm but became stable below this depth. Deep water inflicted higher tiller mortality, minimal increase in dry weight of aerial

KHAKWANI Abdul Aziz; SHIRAISHI Masaaki; ZUBAIR Muhammad; BALOCH Mohammad Safdar; NAVEED Khalid; AWAN Inayatullah

312

Characteristics of the Self-evaporation Behavior of Sprinkled Water near the Triple Point  

NASA Astrophysics Data System (ADS)

For the sake of capturing the basic data in concern with the designing of vacuum evaporation apparatus, characteristics of the self-evaporation behavior of sprinkled water near the triple point has been investigated experimentally. The relationship between the amount of the vaporized water and the pressure in the vessel was elucidated quantitatively on the condition that over-heated water was sprinkled from water supplying nozzles of diameter of 4 mm into the center of the steam area in the heat insulation glass evaporation vessel having diameter of 200 mm and height of 1100 mm. Even under the mild water sprinkling conditions such as no small particle formation, small Reynolds number, and small Weber number, the temperature effectiveness of the self-evaporation in the center of the steam was as high as 80%, which clearly shows the effectiveness of this water-sprinkling method. In addition, the basic data for system designing such as water evaporation coefficient from water layer surface and temperature effectiveness of self-evaporation during the f1ight in the steam space were obtained.

Aizawa, Kazuo; Hayashi, Kanetoshi; Ogoshi, Hidemasa; Maeyama, Katsuya; Yonezawa, Noriyuki

313

Biological monitoring of toxic pollutants in ocean waters: physiological stress testing of bay and coastal mussels in California  

Microsoft Academic Search

This report describes the results of the first two years of a study designed to assess the health of marine ecosystems; the Biological Effects Assessment Study. Using the mussel (Mytilus sp.) as a representative marine organism, the effects of exposure to chronic, low levels of toxic trace metals, pesticides and petroleum hydrocarbons were determined by a method of physiological stress

Severeid

1983-01-01

314

Water-quality characteristics of Everglades National Park, 1959-77, with reference to the effects of water management  

USGS Publications Warehouse

The U.S. Geological Survey has collected water-quality data in the Everglades National Park since 1959. Major ions, macronutrients, trace elements, and pesticides are the primary chemical groups analyzed. The period of record and frequency of sampling vary for each chemical group, with the longest record for the major ions and the shortest for the macronutrients. Within the park there are three major drainageways: Big Cypress Swamp, Shark River Slough, and Taylor Slough. Each drainageway exhibits unique hydrologic conditions, yet there is a high degree of homogeneity in water-quality characteristics among these areas. Seasonal changes in major-ion, trace-element, and macronutrient concentrations are marked in the shallow marsh. Concentrations generally increase in the dry season due to evapotranspiration, changes in chemical equilibria, and precipitation. Water-management practices in south Florida have changed the water quality in the Shark River Slough. Most major-ion, dissolved-solid, and iron concentrations and color levels have steadily increased since 1963. The water quality in the other two drainageways has not changed since sampling began. Chlorinated-hydrocarbon insecticide residues in bottom material were found in low concentration at every sampling station in the park. (USGS)

Waller, Bradley G.

1982-01-01

315

Seabed characteristics from ambient noise at three shallow water sites in Northern Indian Ocean.  

PubMed

Ambient noise measurements at three sites along the Indian continental shelf, with different water column and seabed, are analyzed to derive vertical directionality and further estimation of seabed characteristics. Directionality pattern is interpreted using features in the sound speed profiles, in terms of noise notch, surface duct, surface bottom reflections, direct arrivals, and high bottom loss arrivals. Reflection loss estimated from the field directionality is seen to be the same for a particular site and gives an estimate of the sea bottom. Seabed characteristics such as critical angle and reflection coefficient from field directionality correlate well with theoretical estimation using ground truths. PMID:24116544

Sanjana, M C; Latha, G; Mahanty, M M

2013-10-01

316

Application of the characteristic CIP method to a shallow water model on the sphere  

NASA Astrophysics Data System (ADS)

Semi-implicit algorithms are popularly used to deal with the gravitational term in numerical models. In this paper, we adopt the method of characteristics to compute the solutions for gravity waves on a sphere directly using a semi-Lagrangian advection scheme instead of the semi-implicit method in a shallow water model, to avoid expensive matrix inversions. Adoption of the semi-Lagrangian scheme renders the numerical model always stable for any Courant number, and which saves CPU time. To illustrate the efficiency of the characteristic constrained interpolation profile (CIP) method, some numerical results are shown for idealized test cases on a sphere in the Yin-Yang grid system.

Peng, Xindong; Chang, Yan; Li, Xingliang; Xiao, Feng

2010-07-01

317

Physiological Waterfalls  

ERIC Educational Resources Information Center

|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)|

Leith, David E.

1976-01-01

318

Effect of Ionic Soil Stabilizers on Soil-Water Characteristic of Special Clay  

NASA Astrophysics Data System (ADS)

The engineering properties of special clay are conventionally improved through the use of chemical additive such as ionic soil stabilizer (ISS). Such special clays are often referred to as stabilized or treated clays. The soil-water characteristic curves (SWCC) of special clays from Henan province and Hubei province were measured both in natural and stabilized conditions using the pressure plate apparatus in the suction range of 0-500 kPa. The SWCC results are used to interpret the special clays behavior due to stabilizer treatment. In addition, relationships were developed between the basic clay and stabilized properties such as specific surface area and pore size distribution. The analysis showed that specific surface area decreases, cumulative pore volume and average pore size diameter decrease, dehydration rate slows and the thickness of water film thins after treatment with Ionic Soil Stabilizer. The research data and interpretation analysis presented here can be extended to understand the water film change behaviors influencing the mechanical and physical properties of stabilized special clay soils. KEY WORDS: ionic soil stabilizer, special clay, pore size diameter, specific surface area, soil water characteristic curve, water film

Cui, D.; Xiang, W.

2011-12-01

319

Identification of characteristic regions and representative stations: a study of water quality variables in the Kattegat.  

PubMed

Gradients in nutrient distributions and the effects of eutrophication are common features in most coastal marine areas. These structures occur in aquatic systems due to spatial differences in hydrography, nutrient loading and key biogeochemical processes. Two statistical methods, cluster analysis and probability mapping, have been used in the present study to determine characteristics and patterns in water quality variables. Combined, these two methods provide a useful tool to statistically determine spatial homogeneity and representativity of areas and stations. A case study is presented here in which water quality variables (salinity, dissolved inorganic nitrogen, dissolved inorganic phosphorus and chlorophyll) in surface waters of the Kattegat are analysed for the time period 1993-1997. It was found that morphology, the proximity to sources of nutrient loading from land, nutrient uptake and the infrequent water exchange between the Baltic Sea in the south and the Skagerrak in the north all contribute to create distinct regions of water quality. Regions with concentrations significantly different from the overall mean are identified. In addition to identification of regions with similar characteristics, representative stations (as well as not representative stations) for the respective regions were made. This type of information can be used to design new or revise old monitoring programs. PMID:15887373

Danielsson, A; Rahm, L; Conley, D J; Carstensen, J

2004-01-01

320

Environmental characteristics and water quality of hydrologic benchmark network stations in the west-central United States, 1963-95  

USGS Publications Warehouse

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.

Clark, Melanie L.; Eddy-Miller, C. A.; Mast, M. Alisa

2000-01-01

321

Environmental characteristics and water quality of hydrologic benchmark network stations in the western United States, 1963-95  

USGS Publications Warehouse

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.

Mast, M. Alisa.; Clow, David W.

2000-01-01

322

Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water  

SciTech Connect

The nuclear criticality characteristics of mixtures of plutonium, silicon dioxide, and water (Part A) or plutonium, silicon dioxide, Nevada Yucca Mountain tuff, and water (Part B) have become of interest because of the appearance of recent papers on the subject. These papers postulate that if excess weapons plutonium is vitrified into a silicate log and buried underground, a self-sustaining neutron chain reaction may develop given sufficient time and interaction with the burial medium. Moreover, given specific geologic actions resulting in postulated configurations, the referenced papers state that nuclear explosions could occur with multi-kiloton yields or yields equivalent to hundreds of tons of TNT.

Sanchez, R.; Myers, W.; Hayes, D. [and others

1997-01-01

323

The Effect of Heat on Structural Characteristics and Water Absorption Behavior of Agave Fibers  

NASA Astrophysics Data System (ADS)

The structural characteristics and water absorptions behavior agave fibers were investigated over a range of temperature by using XRD, IR, TG and gravimetric methods. Three distinct thermal processes were observed during heating the fiber in the temperature range 310-760 K in air, oxygen and nitrogen invariably. The cellulose structures of the fibers were unaffected on heating up to 450 K. The samples showed thermal decomposition processes beyond 500 K. Fibers displayed a two-stage diffusion behavior. The structural parameters and kinetic of water absorption of the fibers at specific temperatures were analyzed.

Saikia, Dip

2008-04-01

324

An experimental investigation of the burning characteristics of water-oil emulsions  

SciTech Connect

An experimental investigation was conducted on the combustion characteristics of droplets of n-heptane, n-decane, n-dodecane, n-hexadecane and iso-octane emulsified with various amount of water and freely falling in a furnace of controlled temperature. Results demonstrate the intricate influences of water emulsification on the ignition, extinction and micro-explosion of the droplet response, and that the droplet burning time can be significantly reduced through judicious fuel blending so as to minimize the ignition delay and advance the onset of micro-explosion.

Wang, C.H.; Chen, J.T. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

1996-10-01

325

Selected basin characteristics and water-quality data of the Minnesota River basin  

USGS Publications Warehouse

Selected basin characteristics and water-quality dam for the Minnesota River Basin are presented in this report as 71 maps, 22 graphs, and 8 tables. The data were compiled as part of a four-year study to identify non-point sources of pollution and the effect of this pollution on water quality. The maps were prepared from geographic information system data bases. Federal, State, and local agencies, and colleges and universities collected and assembled these data as part of the Minnesota River Assessment Project.

Winterstein, T. A.; Payne, G. A.; Miller, R. A.; Stark, J. R.

1993-01-01

326

Effects of diesel engine speed and water content on emission characteristics of three-phase emulsions.  

PubMed

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

Lin, Cherng-Yuan; Wang, Kuo-Hua

2004-01-01

327

Characteristics of streamer discharge development between the dielectric-coated sphere-plane electrodes in water  

SciTech Connect

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.

Zhu Taiyun; Yang Lanjun; Jia Zhijie; Zhang Qiaogen [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049 (China)

2008-12-01

328

The water withdraws and spectral characteristic analysis of back groundsurface features in Zengcheng City  

NASA Astrophysics Data System (ADS)

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.

Gao, Ai; Xia, Lihua

2008-10-01

329

Characteristics of streamer discharge development between the dielectric-coated sphere-plane electrodes in water  

NASA Astrophysics Data System (ADS)

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 (U10%) 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 U10% 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.

Zhu, Taiyun; Yang, Lanjun; Jia, Zhijie; Zhang, Qiaogen

2008-12-01

330

Characteristics of the cold-water belt formed off Soya Warm Current  

NASA Astrophysics Data System (ADS)

We examined the data obtained by acoustic Doppler current profiler, conductivity-temperature-depth profiler, and expendable bathythermograph observations, which were collected in the summers of 2000, 2001, and 2002, to clarify the characteristics of the cold-water belt (CWB), i.e., lower-temperature water than the surrounding water extending from the southwest coast of Sakhalin along the offshore side of Soya Warm Current (SWC) and to confirm one of the formation mechanisms of the CWB as suggested by our previous study, i.e., the upwelling due to the convergence of bottom Ekman transport off the SWC region. The CWB was observed at about 30 km off the coast, having a thickness of 14 m and a minimum temperature of 12°C at the sea surface. The CWB does not have the specific water mass, but is constituted of three representative water types off the northeast coast of Hokkaido in summer, i.e., SWC water, Fresh Surface Okhotsk Sea Water, and Okhotsk Sea Intermediate Water. In a comparison of the horizontal distributions of current and temperature, the CWB region is found to be advected to the southeast at an average of 40 ± 29% of the maximum current velocity of the SWC. The pumping speed due to the convergence of the bottom Ekman transport is estimated as (1.5-3.0) × 10-4 m s-1. We examined the mixing ratio of the CWB, and the results implied that the water mass of the CWB is advected southeastward and mixes with a water mass upwelling in a different region off SWC.

Ishizu, Miho; Kitade, Yujiro; Matsuyama, Masaji

2008-12-01

331

Preparation and characteristic of triolein-embedded composite sorbents for water purification  

Microsoft Academic Search

The novel triolein-embedded composite sorbents for removing persistent organic pollutants (POPs) in water were developed. Comprehensive structural characteristics of the composite sorbents were characterized using scanning electron microscope (SEM), fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectrum (XPS). It is suggested that triolein\\/cellulose acetate (CA) viscous syrup can be deposited on the surface of silica gel granules, because the

Jinxian Huo; Huijuan Liu; Jiuhui Qu; Zijian Wang; Jiantuan Ge; Haining Liu

2005-01-01

332

Water Absorption Characteristics and Volume Changes of Milled and Brown Rice During Soaking  

Microsoft Academic Search

Cereal Chem. 83(6):624-631 The water absorption characteristics and volume changes of rice with various degrees of milling during soaking were measured at five temper- atures (5-40°C). The measured data were fitted to the exact solution for the infinite plane sheet diffusion model, which is an exact solution for the diffusion equation. The measured results agreed well with the model. The

Y. Muramatsu; A. Tagawa; E. Sakaguchi; T. Kasai

2006-01-01

333

Bubble characteristics of steam–water two-phase flow in a large-diameter pipe  

Microsoft Academic Search

Bubble characteristics of steam–water two-phase upward flow were observed in a vertical pipe 155 mm in inner diameter. Experiments were conducted under volumetric flux conditions of JG<0.25 m\\/s and JL<0.6 m\\/s, and three different inlet boundary conditions to investigate the developing state of the flow. The radial distributions of flow structure were obtained by horizontally traversing optical dual void probes

Kimitoshi Yoneda; Akira Yasuo; Tomio Okawa

2002-01-01

334

Chemical and physical characteristics of water in estuaries of Texas, October 1976-September 1978  

USGS Publications Warehouse

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)

Fisher, J. C.

1982-01-01

335

[Analysis on characteristics of red tide in Fujian coastal waters during the last 10 years].  

PubMed

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

Li, Xue-Ding

2012-07-01

336

The physiological response, time-motion characteristics and reproducibility of various speed endurance drills in elite youth soccer players: small sided games vs generic running.  

PubMed

The aim of the study was to quantify the physiological responses, time-motion characteristics and reproducibility of various speed endurance production (SEP) and speed endurance maintenance (SEM) drills. Twenty-one elite male youth soccer players completed four drills: (1) SEP 1 v 1 small sided game, (2) SEP running drill, (3) SEM 2 v 2 small sided game and (4) SEM running drill. The SEP drills consisted of eight bouts of 30 s with 120 s recovery (1:4 exercise to rest ratio) whilst SEM drills encompassed eight bouts of 60 s with 60 s recovery (1:1 exercise to rest ratio). Heart rate response, blood lactate concentration, rating of perceived exertion and time-motion characteristics were recorded for each drill. The SEP and SEM running drills elicited greater (P<0.05) heart rate responses, blood lactate concentrations and subjective ratings of perceived exertion than the equivalent small sided games (ES: 1.1-1.4 & 1.0-3.2). Players covered less (P<0.01) total distance, high-, very high-speed running and sprint distance in the SEP and SEM small sided game's compared to the equivalent running drills (ES: 6.0-22.1 & 3.0-18.4). Greater distances (P<0.01) were covered in high and maximum acceleration/deceleration bands during the SEP and SEM small sided game's compared to the equivalent running drills (ES: 2.6-4.6 and 2.3-4.8). Small-moderate test-retest variability was observed for heart rate response (CV: 0.9-1.9%), ratings of perceived exertion (CV: 2.9-5.7%) and blood lactate concentration (CV: 9.9-14.4%); Moderate-large test-retest variability was observed for high-intensity running parameters (CV: >11.3%) and the majority of acceleration/deceleration distances (CV: >9.8%) for all small sided games and running drills. The data demonstrate the differential response of SEP and SEM training for taxing various energy systems and the superior acceleration/deceleration profiles of small sided games compared to generic running drills. PMID:24159151

Ade, J; Harley, J; Bradley, P

2013-11-01

337

River basin water resource compensation characteristics by set pair analysis: the Dongjiang example  

NASA Astrophysics Data System (ADS)

Flood and drought coexist in many river basins, thus analyses of water resource compensation characteristics become important, since they are the foundation for rational utilization of floodwaters. In this research, set pair analysis (SPA), a relatively new uncertainty analysis method, is used to study the dry and wet compensation characteristics of water resource parameters. In addition, fuzzy membership and grey correlation degree are adopted to test the result of set pair analysis. The Dongjiang River is taken as an example and the analyzed parameters include precipitation and mean discharge from different hydrological stations. The results show that there is a high homeotype-encountering chance for precipitation and mean discharge between different stations for both dry and wet conditions; thus the compensation capacity is small. Although the mean discharge is synchronous with the precipitation in the river basin, there exists a certain degree of shift, indicating possible utilization of floodwater on a small scale. The results from SPA are consistent with that from a traditional analysis method, showing that SPA is a promising alternative method for studying river basin water resource compensation characteristics, in particular for exploring potential complements embedded in non-complementary general features.

Chen, Qiuwen; Li, Jing; Li, Ruonan; Wei, Wenda; Wang, Liming

2013-10-01

338

Gross primary production variability associated with meteorology, physiology, leaf area, and water supply in contrasting woodland and grassland semiarid riparian ecosystems  

NASA Astrophysics Data System (ADS)

Understanding ecosystem-atmosphere carbon exchanges in dryland environments has been more challenging than in mesic environments, likely due to more pronounced nonlinear responses of ecosystem processes to environmental variation. To better understand diurnal to interannual variation in gross primary productivity (GPP) variability, we coupled continuous eddy-covariance derived whole ecosystem gas exchange measurements with an ecophysiologic model based on fundamental principles of diffusion, mass balance, reaction kinetics, and biochemical regulation of photosynthesis. We evaluated the coupled data-model system to describe and understand the dynamics of 3 years of growing season GPP from a riparian grassland and woodland in southern Arizona. The data-model fusion procedure skillfully reproduced the majority of daily variation GPP throughout three growing seasons. While meteorology was similar between sites, the woodland site had consistently higher GPP rates and lower variability at daily and interannual timescales relative to the grassland site. We examined the causes of this variation using a new state factor model analysis that partitioned GPP variation into four factors: meteorology, physiology, leaf area, and water supply. The largest proportion of GPP variation was associated with physiological differences. The woodland showed a greater sensitivity than the grassland to water supply, while the grassland showed a greater sensitivity to leaf area. These differences are consistent with hypotheses of woody species using resistance mechanisms, stomatal regulation, and grassland species using resilience mechanisms, leaf area regulation, in avoiding water stress and have implications for future GPP sensitivity to climate variability following wood-grass transitions.

Jenerette, G. D.; Scott, R. L.; Barron-Gafford, G. A.; Huxman, T. E.

2009-12-01

339

Effects of soft-water acclimation on the physiology, swimming performance, and cardiac parameters of the rainbow trout, Oncorhynchus mykiss.  

PubMed

Rainbow trout acclimated to soft water were submitted to an incremental velocity trial, and exhibited a 14% decrease in critical swimming speed (U(crit) * 1.37 +/- 0.055 vs. 1.54 +/- 0.044 m s(-1)) compared to fish kept in hard water. After a standardized swimming protocol, soft-water-acclimated fish had higher blood lactate concentrations (6.5 +/- 0.66 and 6.0 +/- 0.64 mmol L(-1) (soft water) vs. 5.0 +/- 0.46 and 3.9 +/- 0.32 mmol L(-1) (hard water)), revealing a greater use of anaerobic metabolism for the same exercise. Cardiovascular parameters were investigated while fish were swimming at increasing water velocities, revealing that soft-water-acclimated fish had lower increases in heart rate (105% vs. 118% of pre-exercise values), due to higher heart rates observed during acclimation and during the first 10 min of the swimming trial. This was also reflected by the plateau in heart rate and stroke volume observed during the swimming protocol, which can be attributed to increased cardiovascular function in response to soft-water acclimation. These results are in accord with previously reported increases in blood-to-water diffusion distance, due to proliferation of chloride cells at the gills in response to soft-water conditions, and underscore the costs and limitations of soft-water acclimation. PMID:18958588

Dussault, E B; Playle, R C; Dixon, D G; McKinley, R S

2007-11-15

340

Immunological and physiological characteristics of the rapid immune hemolysis of neuraminidase-treated sheep red cells produced by fresh guinea pig serum  

PubMed Central

The rapid hemolysis by fresh guinea pig serum known to occur with neuraminidase-treated sheep red cells has been investigated with respect to the immunological and physiological properties of the lytic process. The following observations were made: (a) The susceptibility to hemolysis is directly proportional to the amounts of neuraminic acid enzymatically released from the cell surface. Complement lysis is mediated through binding of an IgM antibody protein to membranes of neuraminidase-treated cells. (b) Hemolysis is relatively temperature- independent above about 28 degrees C but below which a decrease in the hemolysis rate occurs. Arrhenius activation energies above and below the transition temperature were therefore found to be different. (c) Colloid osmotic swelling of neuraminidase-treated high potassium sheep red cells with a chloride ion concentration ratio near unity suspended in high potassium medium could not be prevented by sucrose. Hence, colloid osmotic swelling before lysis must be due to the entrance of sucrose and water since sucrose was the only external solute not at equilibrium. (d) From the rate of swelling and the apparent flux of sucrose under nonsteady state conditions an experimental permeability coefficient (P) for sucrose of 3-10(-8) cm-s-1 was computed. Comparison with a theoretical P of 4-10(-6) cm-s-1 for sucrose freely permeating through a single, hypothetical membrane lesion per cell of 60 A effective diameter indicates a membrane lesion which permits the passage of solutes larger than cations, but clearly constrains the free diffusion of sucrose.

1975-01-01

341

Benthic invertebrate population characteristics as affected by water quality in coal-bearing regions of Tennessee  

USGS Publications Warehouse

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)

Bradfield, A. D.

1986-01-01

342

Acoustical characteristics of water sounds for soundscape enhancement in urban open spaces.  

PubMed

The goal of the present study is to characterize water sounds that can be used in urban open spaces to mask road traffic noise. Sounds and visual images of a number of water features located in urban open places were obtained and subsequently analyzed in terms of psychoacoustical metrics and acoustical measures. Laboratory experiments were then conducted to investigate which water sound is appropriate for masking urban noise. The experiments consisted of two sessions: (1) Audio-only condition and (2) combined audio-visual condition. Subjective responses to stimuli were rated through the use of preference scores and 15 adjectives. The results of the experiments revealed that preference scores for the urban soundscape were affected by the acoustical characteristics of water sounds and visual images of water features; Sharpness that was used to explain the spectral envelopes of water sounds was proved to be a dominant factor for urban soundscape perception; and preferences regarding the urban soundscape were significantly related to adjectives describing "freshness" and "calmness." PMID:22423706

Jeon, Jin Yong; Lee, Pyoung Jik; You, Jin; Kang, Jian

2012-03-01

343

[Characteristics of stable isotopes in soil water under several typical land use patterns on Loess Tableland].  

PubMed

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

Cheng, Li-Ping; Liu, Wen-Zhao

2012-03-01

344

Kinetics of physiological skin flora in a suction blister wound model on healthy subjects after treatment with water-filtered infrared-A radiation.  

PubMed

The effect of water-filtered infrared-A radiation (wIRA) on normal skin flora was investigated by generating experimental wounds on the forearms of volunteers utilizing the suction blister technique. Over 7 days, recolonization was monitored parallel to wound healing. Four groups of treatment were compared: no therapy (A), dexpanthenol cream once daily (B), 20 min wIRA irradiation at 30 cm distance (C), and wIRA irradiation for 30 min once daily together with dexpanthenol cream once daily (D). All treatments strongly inhibited the recolonization of the wounds. Whereas dexpanthenol completely suppressed recolonization over the test period, recolonization after wIRA without (C) and in combination with dexpanthenol (D) was suppressed, but started on day 5 with considerably higher amounts after the combination treatment (D). Whereas the consequence without treatment (A) was an increasing amount of physiological skin flora including coagulase-negative staphylococci, all treatments (B-D) led to a reduction in physiological skin flora, including coagulase-negative staphylococci. In healthy volunteers, wIRA alone and in combination with dexpanthenol strongly inhibited bacterial recolonization with physiological skin flora after artificial wound setting using a suction-blister wound model. This could support the beneficial effects of wIRA in the promotion of wound healing. PMID:22123525

Daeschlein, G; Alborova, J; Patzelt, A; Kramer, A; Lademann, J

2011-11-25

345

The influence of water body characteristics on phytoplankton diversity and production in the Celtic Sea  

NASA Astrophysics Data System (ADS)

The influence of water body characteristics on phytoplankton biodiversity and production has been studied in stratified, mixed and frontal water masses in the Celtic Sea. The stations were in close geographical proximity to each other, yet very different phytoplankton assemblages were found. The factors that control phytoplankton biodiversity were investigated. Satellite remote sensing was used to map the development of stratification and fronts in spring and this placed the stations within a strong temporal context. Stations with a well-mixed water column had high nutrient concentrations, high rates of production and the phytoplankton assemblage was dominated by diatoms. At those stations with a stratified water column, nutrient concentrations were depleted but the assemblage was dominated by dinoflagellates and microflagellates. The ratios of depth-integrated primary production to depth-integrated chlorophyll concentration (P/B ratio) were higher at those stations with mixed water columns than at those in stratified waters. That is, under the low nutrient/high light conditions at the stratified station, there was less production than might have been expected for the quantity of chlorophyll present. The photosynthetic characteristics of the phytoplankton assemblages were determined at the stratified stations. PmB values varied from 1.43 to 4.79 mg C [mg Chl]-1 h-1, while ?B ranged from 0.011 to 0.047 mg C [mg Chl]-1 h-1 (?mol photons m-2 s-1)-1. Phytoplankton biodiversity was low at every station and did not appear to influence primary production rates; the highest rate of daily primary production measured (2.4 g C m-2 d-1) was at a station where a single species accounted for >70% of the phytoplankton biomass.

Pemberton, Katharine; Rees, Andrew P.; Miller, Peter I.; Raine, Robin; Joint, Ian

2004-11-01

346

Dynamic moisture sorption characteristics of xerogels from water-swellable oligo(oxyethylene) lignin derivatives.  

PubMed

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

Passauer, Lars; Struch, Marlene; Schuldt, Stefan; Appelt, Joern; Schneider, Yvonne; Jaros, Doris; Rohm, Harald

2012-11-01

347

Self-Limiting Power Excursion Characteristics of Light Water Reactor, (III) Instrumentation for HTR-Pulse Operation  

Microsoft Academic Search

The Hitachi Training Reactor (HTR) provided with pulse operation capability was utilized for an experimental study on the excursion characteristics of light water reactors. Measurements were performed on reactor power, reactor period, released energy, fuel temperature, fuel cladding strain, pressure in water channel and water activities. The reliability of the instruments and devices employed was confirmed to be satisfactory through

Hidemasa KATO; Munemaro IMAI; Shuji YAMADA; Kiyoshi INOUE; Tomio IIZUKA

1969-01-01

348

Effect of controlled inoculation with specific mycorrhizal fungi from the urban environment on growth and physiology of containerized shade tree species growing under different water regimes.  

PubMed

The aim of this work was to evaluate the effects of selected mycorrhiza obtained in the urban environment on growth, leaf gas exchange, and drought tolerance of containerized plants growing in the nursery. Two-year-old uniform Acer campestre L., Tilia cordata Mill., and Quercus robur L. were inoculated with a mixture of infected roots and mycelium of selected arbuscular (maple, linden) and/or ectomycorrhiza (linden, oak) fungi and grown in well-watered or water shortage conditions. Plant biomass and leaf area were measured 1 and 2 years after inoculation. Leaf gas exchange, chlorophyll fluorescence, and water relations were measured during the first and second growing seasons after inoculation. Our data suggest that the mycelium-based inoculum used in this experiment was able to colonize the roots of the tree species growing in the nursery. Plant biomass was affected by water shortage, but not by inoculation. Leaf area was affected by water regime and, in oak and linden, by inoculation. Leaf gas exchange was affected by inoculation and water stress. V(cmax) and J(max) were increased by inoculation and decreased by water shortage in all species. F(v)/F(m) was also generally higher in inoculated plants than in control. Changes in PSII photochemistry and photosynthesis may be related to the capacity of inoculated plants to maintain less negative leaf water potential under drought conditions. The overall data suggest that inoculated plants were better able to maintain physiological activity during water stress in comparison to non-inoculated plants. PMID:21472449

Fini, Alessio; Frangi, Piero; Amoroso, Gabriele; Piatti, Riccardo; Faoro, Marco; Bellasio, Chandra; Ferrini, Francesco

2011-04-07

349

Understanding down-regulation of photosynthesis under water stress: future prospects and searching for physiological tools for irrigation management  

Microsoft Academic Search

Photosynthetic down-regulation and\\/or inhibition under water stress conditions are determinants for plant growth, survival and yield in drought-prone areas. Current knowledge about the sequence of metabolic events that leads to complete inhibition of photosynthesis under severe water stress is reviewed. An analysis of published data reveals that a key regulatory role for Rubisco in photosynthesis is improbable under water stress

JAUME FLEXAS; JOSEFINA BOTA; JOSEP CIFRE; JOSE MARIANO ESCALONA; JERONI GALMES; JAVIER GULIAS; EL-KADRI LEFI; SARA FLORINDA MARTINEZ-CANELLAS; MARIA TERESA MORENO; MIQUEL RIBAS-CARBO; DIEGO RIERA; BARTOLOME SAMPOL; HIPOLITO MEDRANO

2004-01-01

350

Gas-exchange characteristics, leaf water potential and chlorophyll a fluorescence in oil palm ( Elaeis guineensis Jacq.) seedlings under water stress and recovery  

Microsoft Academic Search

The gas-exchange characteristics, leaf water potential and chlorophyll (Chl) a fluorescence of oil palm (Elaeis guineensis Jacq.) seedlings subjected to water stress and recovery were investigated in a greenhouse experiment. At 24 days after imposition\\u000a of stress, leaf water potential in water-stressed seedlings was doubled compared to that of control and there was a drastic\\u000a decline in gas-exchange parameters viz.

K. Suresh; C. Nagamani; K. Ramachandrudu; R. K. Mathur

2010-01-01

351

Water use physiologies of co-occurring goldenrods ( Solidago juncea and S. canadensis ): Implications for natural distributions  

Microsoft Academic Search

Water use patterns and the seasonal progression of functional leaf area were determined for Solidago canadensis L. var. scabra and S. juncea Ait., two species of cooccurring goldenrods which differ in their competitive ability and distribution along soil moisture gradients. Field measurements of diurnal trends in stomatal conductances and leaf water potentials indicate little difference between the species. Laboratory gas

M. A. Potvin; P. A. Werner

1983-01-01

352

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.  

PubMed

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. PMID:10689173

Kerkhof, L; Santoro, M; Garland, J

2000-03-01

353

Nutrient characteristics of the water masses and their seasonal variability in the eastern equatorial Indian Ocean.  

PubMed

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

Sardessai, S; Shetye, Suhas; Maya, M V; Mangala, K R; Prasanna Kumar, S

2010-05-27

354

Electrical breakdown and volt-ampere characteristics in water vapor in microgaps  

NASA Astrophysics Data System (ADS)

Although the physics for breakdown initiation in gases in generally well understood, the process of breakdown initiation in liquids is much less clear. A large number of experimental data on the breakdown in water revealed that the breakdown voltage in water is of the same magnitude as in the case of gases. This means that the breakdown in liquids can occur not at the extremely high electric fields required by the Paschen curve, but at those that only slightly exceed the breakdown electric fields in atmospheric-pressure molecular gases. This letter contains the results of experimental study on electrical breakdown characteristics in water vapor in microgaps between two parallel electrodes. Measurements were performed for the pressures of 24.15 torr, 20.85 torr and 14.55 torr with the gap size ranging from 40 ?m to 900 ?m. Considering that the atmospheric pressure sources operate in ambient air which unavoidably contains water vapor it is of great importance to investigate the basic processes and properties of discharges in water vapor.

Klas, M.; Matej?ik, Š.; Radmilovi?-Radjenovi?, M.; Radjenovi?, B.

2012-09-01

355

Throwing velocities, anthropometric characteristics, and efficacy indices of women's European water polo subchampions.  

PubMed

Water polo is a team sport characterized by a high-intensity, intermittent activity, where technical and tactical aspect are of a great importance. For that reason, the main aim of this study was to define the anthropometrical characteristics, maximum isometric grip strength, training and competition throwing velocities, and the efficacy indices in female high-level water polo players. A second purpose was to examine the differences between the throwing velocities in training vs. European championships in the water polo female national team. Ten elite trained female water polo players participated in this study. Before the competitive phase of their season, the following measures were taken: standard anthropometry, static and dynamic training throwing velocities, and hand-grip dynamometry. In the competitive phase, efficacy indices, average and maximum throwing velocities from all the participants were also determined. Significant differences (p ? 0.05) were found between different training situations and different competitive throwing velocities. We concluded that elite female water polo players modify their throwing velocity depending if the throw is performed during training or competitive situation. PMID:21993039

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

2011-11-01

356

Study of Cold Heat Energy Release Characteristics of Flowing Ice Water Slurry in a Pipe  

NASA Astrophysics Data System (ADS)

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.

Inaba, Hideo; Horibe, Akihiko; Ozaki, Koichi; Yokota, Maki

357

Residues and Characteristics of Organochlorine Pesticides in the Surface Water in the Suburb of Beijing  

NASA Astrophysics Data System (ADS)

Organochlorine Pesticides (OCPs), such as DDT and HCH, have stable chemical properties and less biodegradability. As a kind of persistent organic pollutants, they have high risk to the environment and human health. Although DDT and HCH have been prohibited in China since 1983, they are still found in some soil and water nowadays. Water resource is very important in natural environment and essential for agriculture. The existence of OCPs in some surface water in Beijing has been detected with different levels according to previous investigations. In recent years, many measures have been taken to control the pollution and to monitor the environment, and more attention has been paid to the status of surface water today. In this study, the water samples were collected from the Wenyu, Beiyun, Yanqing, Fangshan, Changping, and Shunyi Rivers in the suburb of Beijing, and the residues and characteristics of DDT and HCH were studied. The results showed that the contents of DDTs and HCHs were ND-13.98 ng/L and 3.87-146.42 ng/L, respectively. According to the indicators of the ratio values of (DDD+DDE)/DDT and ?-HCH/?-HCH, the source of pollution and its potential risk are also discussed in this article.

CHEN, Jiawei; LIU, Chen; YANG, Zhongfang; WANG, Jiyuan

358

Determination of arsenic in water--quality assurance and calculation of metrological characteristics.  

PubMed

Arsenic is a toxic element, acting as a nerve poison and proven carcinogen. Its main source for humans is drinking water where the most important are arsenic (V) compounds. With respect to the Slovak standard, in force since 1998, the maximum tolerable value is defined as the important characteristic of drinking water. If the value 0.01 mg.l-1 of arsenic is exceeded, water is not drinkable. The mentioned standard defines criteria for precision of the arsenic determination and the corresponding limit of detection--being 10% of the maximum tolerable value. Arsenic content in the drinking water samples was measured by the AAS method. Internal Quality Control for analysis by the ETA AAS method was based on the harmonised guidelines recommended by IUPAC, ISO and AOAC. The following metrological characteristics were calculated: precision, accuracy, and the yield of the arsenic standard addition to the studied sample--matrix spike and analytical spike. In addition to it, a thorough study of the limit of detection, LOD, and the limit of quantification (determination), LOQ, was performed. The LOD and LOQ values were calculated in the traditional way as well as by the ULA technique, newly recommended by IUPAC. In the latter case, the calculated LOD value was close to the demanded 10% limit of the maximum tolerable value, which is 1 microgram.l-1 As. The repeatability and reproducibility, found at two concentration levels 56.02 +/- 0.73 micrograms.l-1 and 6.0 +/- 0.9 microgramsl-1, were 3.2% and 3.9%, respectively, and 7.1% and 9.8%, respectively. Trueness of the applied AAS method was proven satisfactory on the reference material SRM 1643 Trace Elements in Water. PMID:11787248

Borosová, D; Mocak, J; Beinrohr, E; Bobrowski, A

2001-11-01

359

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)

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.

Casper, A. F.

2005-05-01

360

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

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 ?g 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 ?g 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

Hsieh, Shu-Ling; Wu, Chih-Chung; Liu, Chun-Hung; Lian, Juang-Lin

2013-04-18

361

Water-like solvation thermodynamics in a spherically symmetric solvent model with two characteristic lengths  

PubMed Central

We examine by molecular dynamics simulation the solubility of small apolar solutes in a solvent whose particles interact via the Jagla potential, a spherically symmetric ramp potential with two characteristic lengths: an impenetrable hard core and a penetrable soft core. The Jagla fluid has been recently shown to possess water-like structural, dynamic, and thermodynamic anomalies. We find that the solubility exhibits a minimum with respect to temperature at fixed pressure and thereby show that the Jagla fluid also displays water-like solvation thermodynamics. We further find low-temperature swelling of a hard-sphere chain dissolved in the Jagla fluid and relate this phenomenon to cold unfolding of globular proteins. Our results are consistent with the possibility that the presence of two characteristic lengths in the Jagla potential is a key feature of water-like solvation thermodynamics. The penetrable core becomes increasingly important at low temperatures, which favors the formation of low-density, open structures in the Jagla solvent.

Buldyrev, Sergey V.; Kumar, Pradeep; Debenedetti, Pablo G.; Rossky, Peter J.; Stanley, H. Eugene

2007-01-01

362

Scots pine as a model plant for studying the mechanisms of conifers adaptation to heavy metal action: 1. Effects of continuous zinc presence on morphometric and physiological characteristics of developing pine seedlings  

Microsoft Academic Search

Effects of zinc (50–150 ?M ZnSO4) on seed germinability, morphometric and physiological characteristics of Scots pine (Pinus sylvestris L.) seedlings during first 6 weeks of their development were studied. Scots pine turned out to be rather sensitive to elevated\\u000a zinc concentrations. This was manifested in reduced seed germinability, root system growth retardation and suppression of\\u000a its development (primarily, reduction in

Yu. V. Ivanov; Yu. V. Savochkin; Vl. V. Kuznetsov

2011-01-01

363

Drinking water quality in Nepal’s Kathmandu Valley: a survey and assessment of selected controlling site characteristics  

Microsoft Academic Search

Water was sampled from over 100 sources in Nepal’s Kathmandu Valley, including municipal taps, dug wells, shallow-aquifer\\u000a 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\\u000a and site and well characteristics, and water was examined for indicators of contamination from sewage, agriculture, or

Nathaniel R. Warner; Jonathan Levy; Karen Harpp; Frank Farruggia

2008-01-01

364

Soil water repellency: its causes, characteristics and hydro-geomorphological significance  

NASA Astrophysics Data System (ADS)

Water repellency (hydrophobicity) of soils is a property with major repercussions for plant growth, surface and subsurface hydrology, and for soil erosion. Important advances have been made since the late 1980s in identifying the range of environments affected by water repellency, its characteristics and its hydro-geomorphological impacts. This review summarises earlier work, but focusses particularly on these recent advances and identifies remaining research gaps. The associations of water repellency with (a) soils other than coarse-textured ones, (b) an expanding list of plant species, and (c) a widening range of climates other than seasonally dry types have been recurrent themes emphasised in recent literature. Nevertheless, knowledge about the extent of water repellency amongst world soils is still comparatively sparse. Its origin by the accumulation of long-chained organic compounds on or between soil particles is now widely accepted, but understanding of their exact chemical composition and means of attachment to particle surfaces remains incomplete. The transient nature of water repellency has been found to be mainly associated with fluctuations in soil moisture, but the precise processes and required conditions for the changes from hydrophobic to hydrophilic and vice versa are so far only poorly understood. Significant advances relating to the hydro-geomorphological impacts of hydrophobic layers have been made since the late 1980s in identifying and separating the various effects of such layers on surface and subsurface water flow. It has become evident that these effects in turn are influenced by variables such as the frequency and effectiveness of flow pathways through hydrophobic layers as well as their position and transitory behaviour. Recent literature has continued to highlight the role of water repellency in promoting soil erosion and it is now recognised that it can promote rainsplash detachment and soil loss not only by water, but also by wind. Major research gaps, however, remain in (a) isolating the erosional impact of water repellency from other factors, and (b) identifying the exact role of, and the interactions between the different variables controlling development and effectiveness of flow pathways through hydrophobic soil. Improved understanding of the effects of soil water repellency will enable its overall role in surface and subsurface hydrological and erosional processes to become more clearly defined.

Doerr, S. H.; Shakesby, R. A.; Walsh, R. P. D.

2000-08-01

365

The characteristics of fluid flow in beds of small glass particles spouted with water  

Microsoft Academic Search

The characteristics of beds of small glass particles 0.28, 0.46 and 0.77mm in diameter spouted with water were studied in\\u000a a half-cylindrical column 51mm in diameter with inlet tube diameter of 3.2mm. The minimum spouting velocity, bed pressure\\u000a drop at minimum spouting and spout diameter were measured. Assuming Darcy flow, the fluid flow in the annulus is modeled and\\u000a shown

Seung Jai Kim

1984-01-01

366

Wear of nano-TiO2/UHMWPE composites radiated by gamma ray under physiological saline water lubrication.  

PubMed

Nano-TiO(2)/UHMWPE composites were prepared by hot press procedure, and then radiated by gamma ray in dose of 120 kGy, 250 kGy and 500 kGy. The hardness of the composites was initially determined. Subsequently the wear against a CoCrMo alloy counterface were tested in a knee simulator under physiological saline lubrication. The morphologies of the worn surfaces were examined with optical microscope. The structure of the samples was determined by IR and XRD. The results showed that the wear rate of the composite UHMWPE decreased when filled with proper amount of nano-TiO(2) and with the radiation dose. PMID:17665107

Xiong, Dangsheng; Lin, Jianming; Fan, Dongli; Jin, Zhongmin

2007-08-01

367

Dynamic characteristics of laser-induced vapor bubble formation in water based on high speed camera  

NASA Astrophysics Data System (ADS)

In clinical practice, laser ablation usually works under liquid environment such as water, blood or their mixture. Laser-induced vapor bubble or bubble formation and its consequent dynamics were believed to have important influence on tissue ablation. In the paper, the dynamic process of vapor bubble formation and consequently collapse induced by pulsed Ho:YAG laser in static water was investigated by using high-speed camera. The results showed that vapor channel / bubble can be produced with pulsed Ho:YAG laser, and the whole dynamic process of vapor bubble formation, pulsation and consequently collapse can be monitored by using high-speed camera. The dynamic characteristics of vapor bubble, such as pulsation period, the maximum depth and width were determined. The dependence of above dynamic parameters on incident radiant exposure was also presented. Based on which, the influence of vapor bubble on hard tissue ablation was discussed.

Zhang, Xian-zeng; Guo, Wenqing; Zhan, Zhenlin; Xie, Shusen

2013-08-01

368

Characteristics of algal blooms in the southern coastal waters of Korea.  

PubMed

We have investigated the characteristics of algal blooms in relation to the marine environment since their first known occurrence in the southern coastal waters of Korea. The algal blooms occurred most frequently in Masan and Jinahe bays, suggesting that they were related to the development of anoxic water masses. Skeletonema costatum, Heterosigma akashiwo and Prorocentrum sp. commonly occurred as the dominant organisms causing the blooms in all regions, although the conditions of their appearance differed from place to place. Algal blooms in all regions were more likely to occur when precipitation ten days prior to the bloom was greater than the long-term mean values. However, the factors that relate to the development of the algal blooms in Gamak Bay differed depending upon the causative species while they were largely identical in Jinhae Bay, regardless of the species. PMID:17983649

Lee, Moon-Ock; Kim, Jong-Kyu

2007-10-01

369

Thermodynamic characteristics of the acid dissociation of dopamine hydrochloride in water-ethanol solutions  

NASA Astrophysics Data System (ADS)

Enthalpies of the interaction of protonated dopamine with a hydroxide ion in water-ethanol mixtures in the concentration range of 0-0.8 EtOH mole fractions are measured calorimetrically. The neutralization process of dopamine hydrochloride is shown to occur endothermally in solvents with an ethanol concentration of ?0.5 mole fractions. Standard thermodynamic characteristics (?r H ?, ?r G ?, and ?r S ?) of the first-step acid dissociation of dopamine hydrochloride in solutions are calculated with regard to the autoprotolysis enthalpy of binary solvents. It is found that dissociation enthalpies vary within 9.1-64.8 kJ/mol, depending on the water-ethanol solvent composition.

Ledenkov, S. F.; Vandyshev, V. N.; Molchanov, A. S.

2012-06-01

370

Sensitivity Degradation Characteristics of In-core Neutron Detector for Heavy Water Reactor, Fugen NPP  

SciTech Connect

Fugen nuclear power plant is a 165 MWe, heavy water-moderated, boiling light water-cooled, pressure tube-type reactor developed by JNC, which is the world's first thermal neutron power reactor to utilize mainly Uranium and Plutonium mixed oxide (MOX) fuel. Fugen has been loaded a total of 726 MOX fuel assemblies since the initial core in 1978. Each in-core neutron detector assembly of Fugen composed of four Local Power Monitors (LPM) is located at sixteen positions in the area of heavy water moderator in the core and monitors its power distribution during operation. The thermal neutron flux of Fugen is relatively higher than that of Boiling Water Reactor (BWR), therefore LPM, which is comprised of a fission chamber, degrades more quickly than that of BWR. An Improved Long-life LPM (LLPM) pasted inner surface wall of the chamber with {sup 234}U/{sup 235}U at a ratio of 4 to 1 had been developed through the irradiation test at Japan Material Test Reactor (JMTR). The {sup 234}U is converted to {sup 235}U with absorption of neutron, and compensates the consumption of {sup 235}U. LPM has been loaded to the initial core of Fugen since 1978. JNC had evaluated its sensitivity degradation characteristics through the accumulated irradiation data and the parametric survey for {sup 234}U and {sup 235}U. Based on the experience of evaluation for sensitivity degradation, JNC has applied shuffling operation of LPM assemblies during an annual inspection outage to reduce the operating cost. This operation realizes the reduction of replacing number of LPM assemblies and volume of radioactive waste. This paper describes the sensitivity degradation characteristics of in-core neutron detector and the degradation evaluation methods established in Fugen. (authors)

Tsuyoshi Okawa; Naoyuki Yomori [Japan Nuclear Cycle Development Institute (Japan)

2002-07-01

371

Storage of oil field-produced waters alters their chemical and microbiological characteristics.  

PubMed

Many oil fields are in remote locations, and the time required for shipment of produced water samples for microbiological examination may be lengthy. No studies have reported on how storage of oil field waters can change their characteristics. Produced water samples from three Alberta oil fields were collected in sterile, industry-approved 4-l epoxy-lined steel cans, sealed with minimal headspace and stored under anoxic conditions for 14 days at either 4 degrees C or room temperature (ca. 21 degrees C). Storage resulted in significant changes in water chemistry, microbial number estimates and/or community response to amendment with nitrate. During room-temperature storage, activity and growth of sulfate-reducing bacteria (and, to a lesser extent, fermenters and methanogens) in the samples led to significant changes in sulfide, acetate and propionate concentrations as well as a significant increase in most probable number estimates, particularly of sulfate-reducing bacteria. Sulfide production during room-temperature storage was likely to be responsible for the altered response to nitrate amendment observed in microcosms containing sulfidogenic samples. Refrigerated storage suppressed sulfate reduction and growth of sulfate-reducing bacteria. However, declines in sulfide concentrations were observed in two of the three samples stored at 4 degrees C, suggesting abiotic losses of sulfide. In one of the samples stored at room temperature, nitrate amendment led to ammonification. These results demonstrate that storage of oil field water samples for 14 days, such as might occur because of lengthy transport times or delays before analysis in the laboratory, can affect microbial numbers and activity as well as water sample chemistry. PMID:20186564

Hulecki, Jordan C; Foght, Julia M; Fedorak, Phillip M

2010-02-27

372

Benthic invertebrate population characteristics as affected by water quality in coal-bearing regions of Tennessee  

SciTech Connect

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. 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. 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. 44 refs., 1 fig., 8 tabs.

Bradfield, A.D.

1986-01-01

373

Environmental Characteristics and Water Quality of Hydrologic Benchmark Network Stations in the Eastern United States, 1963-95.  

National Technical Information Service (NTIS)

The report describes the environmental characteristics and water quality at 16 benchmark basins in the Eastern United States. The basins and physiographic provinces are as follows: the Wild River, Maine, in the New England Province; Esopus Creek, New York...

M. A. Mast J. T. Turk

1999-01-01

374

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

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.

Kocharunchitt, Chawalit; King, Thea; Gobius, Kari; Bowman, John P.; Ross, Tom

2012-01-01

375

Applied physiology of diving.  

PubMed

Recreational diving is a popular sport, although human ability to stay in and under water is severely limited physiologically. An understanding of these limitations enhances safety and enjoyment of sports diving. Breath-hold diving involves head-out water immersion, apnoea and submersion, exercise, cold stress, and pressure exposure. Each of these components, by itself, elicits prominent and specific physiological effects. Combination of these factors produces a unique and interesting physiological response generally known as diving reflex. Humans display weak diving responses, but exhibit no oxygen conservation function. Nevertheless, application of diving-induced physiological changes is now finding its way into clinical practice. Apnoea, face immersion, and head-out water immersion all show promise of clinical application. There are several spin-offs from diving research worth noting. Diuresis, enhancement of cardiac performance, and redistribution of blood flow, all produced by head-out water immersion, have been shown to be clinically useful, besides providing physiological data useful to space travel. Results from investigations on apnoea have been shown to be relevant to the following: treating some forms of cardiac arrhythmias; understanding drowning, sudden infant death syndrome and sleep apnoea; and confirming hyperventilation as the major cause of drowning. In comparison to marine mammals, humans are poor divers because of severe physiological constraints which limit their breath-hold time, diving depth, and ability to conserve body heat. Although under special circumstances humans can achieve unusually long breath-hold time and reach exceptional depth with a single breath, the sustainable working time and depth are only about 1 minute and 5 metres, respectively. Hypothermia inevitably results in divers working in the ocean. Without thermal protection, the intolerable limit of 35 degrees C is reached within 30 minutes in winter (10 degrees C) water and within 60 to 90 minutes in summer. Nevertheless, effective harvest work can be performed by humans in the ocean, and recreational benefits enhanced when these physiological limitations are respected. An unusual circulatory state exists during head-out water immersion in that there is a sustained increase of stroke volume. This results in 30% increase in cardiac output when the subject is resting in thermal neutral water, indicating a substantial overperfusion for the oxygen requirement. Furthermore, animal experiments showed that the elevated blood flow is preferentially channeled to the liver, fat, and the organs in the splanchnic region.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3278355

Lin, Y C

1988-01-01

376

Measurement of soil-water characteristic curves for fine-grained soils using a small-scale centrifuge  

Microsoft Academic Search

Considerably long periods of time are required to measure soil-water characteristic curves using conventional equipment such as pressure plate apparatus or a Tempe cell. A commercially available, small-scale medical centrifuge with a swinging type rotor assembly was used to measure the soil-water characteristic curves on statically compacted, fine-grained soil specimens. A specimen holder was specially designed to obtain multiple sets

R. M. Khanzode; S. K. Vanapalli; D. G. Fredlund

2002-01-01

377

Applying Pedo-transfer Functions to Simulate Spatial Heterogeneity of Cinnamon Soil Water Retention Characteristics in Western Liaoning Province  

Microsoft Academic Search

In this study, by measuring soil water retention characteristics and fitting them to van Genuchten Equation, three types of\\u000a pedo-transfer functions (PTFs) were estimated using linear regression (MLR3) and nonlinear regression (ENR3) based on three\\u000a textural classifications, and using linear regression (MLR7) based on seven textural classification. And their abilities to\\u000a quantify soil water retention characteristics and spatial heterogeneity in

Zuoxin Liu; Qiaosheng Shu; Zhenying Wang

2007-01-01

378

Is water uptake by reptilian eggs regulated by physiological processes of embryos or a passive hydraulic response to developmental environments?  

PubMed

Moisture availability is critical for successful embryonic development in many organisms. In most oviparous reptiles, for example, water exchange between eggs and the surrounding environment can have substantial fitness consequences, but regulation of this process is unclear. Here, we evaluate whether water uptake by eggs of the lizard Anolis sagrei is regulated by the presence of a live embryo or is a passive hydraulic response to substrate moisture conditions. Many eggs laid in our captive colony were infertile or contained embryos that died during early stages of development, yet these 'dead' eggs continued to gain mass similar to that of 'live' eggs at least during the first half of incubation. Our results suggest that water uptake by eggs is largely a passive hydraulic process during the first half of incubation, but active regulation by embryos may be necessary during latter stages. Maternal effects (e.g., deposition of salts into yolk) could influence this passive process during early incubation. PMID:21820075

Warner, Daniel A; Moody, Melissa A; Telemeco, Rory S

2011-07-24

379

Sensitivity of limber pine (Pinus flexilis) seedling physiology to elevation, warming, and water availability across a timberline ecotone  

NASA Astrophysics Data System (ADS)

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.

Moyes, A. B.; Castanha, C.; Ferrenberg, S.; Germino, M. J.; Kueppers, L. M.

2010-12-01

380

Membrane filtration characteristics in membrane-coupled activated sludge system — the effect of physiological states of activated sludge on membrane fouling  

Microsoft Academic Search

The effect of sludge physiology on membrane fouling was investigated in a membrane-coupled activated sludge (MCAS) system. A series of ultrafiltrations were performed to assess the flux behaviors according to foaming potential, solids retention time (SRT), growth phase and nutrient condition of the activated sludge. The foaming sludge showed greater flux decline than the non-foaming sludge. The extraordinary increase, that

In-Soung Chang; Chung-Hak Lee

1998-01-01

381

Formulation of poorly water-soluble drugs for oral administration: Physicochemical and physiological issues and the lipid formulation classification system  

Microsoft Academic Search

Poorly water-soluble drug candidates often emerge from contemporary drug discovery programs, and present formulators with considerable technical challenges. The absorption of such compounds when presented in the crystalline state to the gastrointestinal tract is typically dissolution rate-limited, and the drugs are typically BCS class II or class IV compounds. Class IV compounds, which have low membrane permeability as well as

Colin W. Pouton

2006-01-01

382

[Spatial distribution characteristics and environmental effect of N and P in water body of Taihu Lake].  

PubMed

The characteristics of spatial distribution of nitrogen and phosphorus in water were studied. The results showed that concentrations of total nitrogen/phosphorus in water from Meiliang Bay, Zhusan Bay, Gonghu Bay, West and Central Taihu Lake were obviously higher than those from any other region of Taihu Lake. The spatial distribution of dissolved nitrogen/phosphorus and detritus nitrogen/phosphorus was consistent with that of total nitrogen/phosphorus. The concentrations of dissolved nitrogen and detritus nitrogen significantly correlated with those of total nitrogen with rDN = 0.8192 and rDeN = 0.6969, respectively; the concentrations of dissolved and detritus phosphorus in water also significantly correlated with that of total phosphorus with rDP = 0.7477 and rDeP = 0.9260, respectively. The discrepancy in spatial distribution of chlorophyll a (Chla) in water was distinctly obvious, the highest level appeared in West Taihu Lake (179.2 microg x L(-1) +/- 25.9 microg x L(-1)), and the lowest in East Taihu Lake (11.3 microg x L(-1) +/- 2.7 microg x L(-1)). There were significantly linear relationships between total nitrogen, detritus nitrogen, total phosphorus, dissolved phosphorus, detritus phosphorus, permanganate index, pH value and suspended solids and the content of Chla with rTN = 0.6622, rDeN = 0.8739, rTP = 0.8130, rDP = 0.4077 and rDeP = 0.8781, rCOD = 0.8689, rpH = 0.5173 and rSS = 0.5334, respectively; while dissolved nitrogen, electric conductivity and alkalinity did not affect Chla in water from Taihu Lake. PMID:19256372

Deng, Jian-cai; Chen, Qiao; Zhai, Shui-jing; Yang, Xu-chang; Han, Hong-juan; Hu, Wei-ping

2008-12-01

383

Prediction of micro-bubble dissolution characteristics in water and seawater  

SciTech Connect

This paper is concerned with the prediction of micro-bubble dissolution characteristics in water and seawater when microbubbles are generated by a Sadatomi-type micro-bubble generator (2003) with a spherical body in a flowing liquid tube. In the experiments, in order to know the effects of the salinity on the characteristics, tap water and an artificial seawater with different salt concentrations of 1 and 3 wt% were used as the test liquids. Parameters measured were the Sauter mean diameter of bubbles, d{sub BS}, the void fraction, {alpha}, the rising velocity of bubbles, u{sub G}, the interfacial area concentration, a, the volumetric mass transfer coefficient, K{sub L}a, and the liquid-side mass transfer coefficient, K{sub L}. In the analysis, for predicting {alpha}, K{sub L}a and K{sub L}, some correlations in the literatures were tested against the present data. Furthermore, in order to improve the predictability, new correlations were developed based on the present data. The prediction of K{sub L}a with the new correlation agreed well with Nishino et al.'s [T. Nishino, K. Terasaka, M. Ishida, Application for several micro-bubble generators for gas absorber, in: Proceedings of the Annual Meeting of the Japanese Society for Multiphase Flow, 2006, pp. 276-277 (in Japanese)] and Li and Tsuge's [P. Li, H. Tsuge, Water treatment by induced air flotation using microbubbles, Journal of Chemical Engineering of Japan 39 (2006) 896-903; P. Li, H. Tsuge, Ozone transfer in a new gas-induced contactor with microbubbles, Journal of Chemical Engineering of Japan 39 (2006) 1213-1220] data for different aeration systems using several different micro-bubble generators. (author)

Kawahara, Akimaro; Sadatomi, Michio; Matsuura, Hidetoshi; Tominaga, Mayo; Noguchi, Masanori [Department of Mechanical System Engineering, Kumamoto University, Kurokami 2-39-1, Kumamoto City 860-8555 (Japan); Matsuyama, Fuminori [Department of Mechanical Engineering, Sasebo National College of Technology (Japan)

2009-07-15

384

Alluvial Characteristics, Groundwater-Surface Water Exchange and Hydrological Retention in Headwater Streams  

NASA Astrophysics Data System (ADS)

Conservative solute injections were conducted in three first-order montane streams of different geological composition to assess the influence of parent lithology and alluvial characteristics on the hydrological retention of nutrients. Three study sites were established: (1) Aspen Creek, in a sandstone-siltstone catchment with a fine-grained alluvium of low hydraulic conductivity (1·3×10-4 cm/s), (2) Rio Calaveras, which flows through volcanic tuff with alluvium of intermediate grain size and hydraulic conductivity (1·2×10-3 cm/s), and (3) Gallina Creek, located in a granite/gneiss catchment of coarse, poorly sorted alluvium with high hydraulic conductivity (4·1×10-3 cm/s). All sites were instrumented with networks of shallow groundwater wells to monitor interstitial solute transport. The rate and extent of groundwater-surface water exchange, determined by the solute response in wells, increased with increasing hydraulic conductivity. The direction of surface water-groundwater interaction within a stream was related to local variation in vertical and horizontal hydraulic gradients. Experimental tracer responses in the surface stream were simulated with a one-dimensional solute transport model with inflow and storage components (OTIS). Model-derived measures of hydrological retention showed a corresponding increase with increasing hydraulic conductivity.To assess the temporal variability of hydrological retention, solute injection experiments were conducted in Gallina Creek under four seasonal flow regimes during which surface discharge ranged from baseflow (0·75 l/s in October) to high (75 l/s during spring snowmelt). Model-derived hydrological retention decreased with increasing discharge.The results of our intersite comparison suggest that hydrological retention is strongly influenced by the geologic setting and alluvial characteristics of the stream catchment. Temporal variation in hydrological retention at Gallina Creek is related to seasonal changes in discharge, highlighting the need for temporal resolution in studies of the dynamics of surface water-groundwater interactions in stream ecosystems.

Morrice, John A.; Valett, H. Maurice; Dahm, Clifford N.; Campana, Michael E.

1997-03-01

385

Studies on physico-chemical characteristics and sediment environment along the coastal waters in Pulau Tuba, Langkawi, Malaysia  

Microsoft Academic Search

Field observations on physico-chemical characteristics of water and sediment quality were carried out from March, 2005 to Dec, 2005 at 4 different stations (Station 1 – Main Jetty Pulau Tuba, Station 2 – Pulau Tuba Jetty number 2, Station 3 – Simpan Tiga Mangrove Area and Station 4 – Kuah Jetty) along the coastal waters iin Pulau Tuba, Langkawi. The

K. C. A. Jalal; H. N. Noor Faizul; B. Y. Kamaruzzaman; S. Shahbudin; M. Z. Alam; Jaswir Irwandi

2009-01-01

386

Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study was conducted to assess the influence of suspended solids, dissolved organic carbon, and phytoplankton (as chlorophyll a) water quality characteristics on lambda-cyhalothrin and gamma-cyhalothrin aqueous toxicity to Hyalella azteca using natural water from 12 ponds and lakes in Mississipp...

387

Kirke's Physiology  

Microsoft Academic Search

IN Kirke's ``Physiology'' (p. 128, 7th edition) mention is made of a conception, due to Mr. Savory, concerning a probable function of the Sinuses of Valsalva, which appears to me to be based on a neglect of an important hydrostatical law. And as this error is not only widely spread, but is considered a point of some importance among students

W. Percy Ashe

1875-01-01

388

Research on water discharge characteristics of PEM fuel cells by using neutron imaging technology at the NRF, HANARO.  

PubMed

An investigation into the water discharge characteristics of proton exchange membrane (PEM) fuel cells is carried out by using a feasibility test apparatus and the Neutron Radiography Facility (NRF) at HANARO. The feasibility test apparatus was composed of a distilled water supply line, a compressed air supply line, heating systems, and single PEM fuel cells, which were a 1-parallel serpentine type with a 100 cm(2) active area. Three kinds of methods were used: compressed air supply-only; heating-only; and a combination of the methods of a compressed air supply and heating, respectively. The resultant water discharge characteristics are different according to the applied methods. The compressed air supply only is suitable for removing the water at a flow field and a heating only is suitable for water at the MEA. Therefore, in order to remove all the water at PEM fuel cells, the combination method is needed at the moment. PMID:18242098

Kim, TaeJoo; Sim, CheulMuu; Kim, MooHwan

2007-12-23

389

Survival and physiological responses of hatchling blanding's turtles (Emydoidea blandingii) to submergence in normoxic and hypoxic water under simulated winter conditions.  

PubMed

Overwintering habits of hatchling Blanding's turtles (Emydoidea blandingii) are unknown. To determine whether these turtles are able to survive winter in aquatic habitats, we submerged hatchlings in normoxic (155 mmHg Po2) and hypoxic (6 mmHg Po2) water at 4 degrees C, recording survival times and measuring changes in key physiological variables. For comparison, we simultaneously studied hatchling softshell (Apalone spinifera) and snapping (Chelydra serpentina) turtles, which are known to overwinter in aquatic habitats. In normoxic water, C. serpentina and A. spinifera survived to the termination of the experiment (76 and 77 d, respectively). Approximately one-third of the E. blandingii died during 75 d of normoxic submergence, but the cause of mortality was unclear. In hypoxic water, average survival times were 6 d for A. spinifera, 13 d for E. blandingii, and 19 d for C. serpentina. Mortality during hypoxic submergence was probably caused by metabolic acidosis, which resulted from accumulated lactate. Unlike the case with adult turtles, our hatchlings did not increase plasma calcium and magnesium, nor did they sequester lactate within the shell. Our results suggest that hatchling E. blandingii are not particularly well suited to hibernation in hypoxic aquatic habitats. PMID:15887082

Dinkelacker, Stephen A; Costanzo, Jon P; Iverson, John B; Lee, Richard E

2005-05-04

390

Effect of pH on the rheological and structural properties of gels of water-washed chicken-breast muscle at physiological ionic strength.  

PubMed

Adjustment of pH from 6.4 to neutrality improved gelling ability and water-holding capacity of twice water-washed, minced chicken-breast muscle significantly at physiological ionic strength, at which the majority of the myofibrillar proteins, including myosin, are not soluble. A strain value of 2.2 was obtained at neutral pH. Myofibrils were the main components of the gel network at both pH 6.4 and 7.0; however, the myofibrillar distribution varied with the pH value. At pH 6.4, myofibrils formed a network of localized aggregates leaving large voids between, whereas at neutral pH, an evenly distributed network of myofibrils was formed. In addition, at neutral pH, a network of fine strands was found within the network of myofibrils. The network was much less developed at pH 6.4. The thin and thick filaments within each myofibrillar structure were disorganized at both pH values. The intramyofibrillar spaces were larger at neutral pH than at pH 6.4. It was proposed that adjustment of pH to neutrality increased electrostatic repulsion leading to a more even distribution of the myofibrillar proteins, a key factor responsible for the improved gel strength and water-holding capacity. PMID:11513691

Feng, Y; Hultin, H O

2001-08-01

391

The Characteristic of Porous Charges on a Base of a Water-Filled RDX Powder  

NASA Astrophysics Data System (ADS)

A detonation velocity of a condensed RDX linearly depends on density at a range of 1,0-1,8 g/cm^3. These charges are porous if the density of RDX monocrystal is 1,806 g/cm^3. The state of porous charge can be characterized by the packing density. It can be rising, if RDX powder will be mixed with water for deciding technological problems. It is necessary to be able to predict characteristics of such charges. Charges on a base of a water-filled RDX powder with air inclusions can be described by three parameters: a density of a charge, packing density of RDX powder and RDX mass fraction. Last two parameters are independent parameters of a mix. We have designed a nomogram for definition of mutual communication of three quantities: velocity of a detonation, density of packing of RDX powder and its mass fraction in a mix. To check up correctness of a prelegends of a nomogram, we have carried out measurement of a detonation velocity of porous water-contained RDX charges. We prepared charges on a base of RDX powder which has consisted of particles with a size 80-220 mcm. We was changing RDX mass fraction of charges in a range 0,6-1,0 and a packing density of RDX powder in a range of 1,0-1,4 g/cm^3. The disorder of experimental data concerning the nomogram data did not exceed basically of 3 percent.

Valiano, Georgy; Yankovskiy, Boris; Milyavskiy, Vladimir; Borodina, Tatiana

2011-06-01

392

Receiver Operating Characteristic Curve Analysis of Beach Water Quality Indicator Variables  

PubMed Central

Receiver operating characteristic (ROC) curve analysis is a simple and effective means to compare the accuracies of indicator variables of bacterial beach water quality. The indicator variables examined in this study were previous day's Enterococcus density and antecedent rainfall at 24, 48, and 96 h. Daily Enterococcus densities and 15-min rainfall values were collected during a 5-year (1996 to 2000) study of four Boston Harbor beaches. The indicator variables were assessed for their ability to correctly classify water as suitable or unsuitable for swimming at a maximum threshold Enterococcus density of 104 CFU/100 ml. Sensitivity and specificity values were determined for each unique previous day's Enterococcus density and antecedent rainfall volume and used to construct ROC curves. The area under the ROC curve was used to compare the accuracies of the indicator variables. Twenty-four-hour antecedent rainfall classified elevated Enterococcus densities more accurately than previous day's Enterococcus density (P = 0.079). An empirically derived threshold for 48-h antecedent rainfall, corresponding to a sensitivity of 0.75, was determined from the 1996 to 2000 data and evaluated to ascertain if the threshold would produce a 0.75 sensitivity with independent water quality data collected in 2001 from the same beaches.

Morrison, Ann Michelle; Coughlin, Kelly; Shine, James P.; Coull, Brent A.; Rex, Andrea C.

2003-01-01

393

Removal of understory dwarf bamboo ( Sasa kurilensis ) induces changes in water-relations characteristics of overstory Betula ermanii trees  

Microsoft Academic Search

We investigated how removal of understory dwarf bamboo (Sasa kurilensis Makino et Shibata) affected growth and water use of young Betula ermanii Cham. trees in a secondary forest in northern Japan. We compared current-year shoot morphology, leaf water-relations characteristics,\\u000a and whole-tree water use of B. ermanii trees growing with dwarf bamboo in the understory (intact plot) to those of trees growing

Hiroaki T. Ishii; Tsuyoshi Kobayashi; Shigeru Uemura; Koichi Takahashi; Yuko T. Hanba; Akihiro Sumida; Toshihiko Hara

2008-01-01

394

Interference of Origanum vulgare L. essential oil on the growth and some physiological characteristics of Staphylococcus aureus strains isolated from foods  

Microsoft Academic Search

The aim of this study was to investigate the chemical composition of Origanum vulgare L. essential oil, the inhibitory effect of the oil on the cell viability of Staphylococcus aureus strains isolated from foods, and the influence of sub-inhibitory concentrations of the oil on some physiological attributes of these strains. GC–MS analysis showed that carvacrol (57.71%) was the most prevalent

Jefferson Carneiro de Barros; Maria Lúcia da Conceição; Nelson Justino Gomes Neto; Ana Caroliny Vieira da Costa; José Pinto Siqueira; Irinaldo Diniz Basílio; Evandro Leite de Souza

2009-01-01

395

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

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 Kruskal–Wallis 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.

Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

2012-01-01

396

More than just a vulnerable pipeline: xylem physiology in the light of ion-mediated regulation of plant water transport.  

PubMed

Major restrictions to the hydraulic conductance of xylem (K(XYL)) in vascular plants have traditionally been attributed to anatomical constraints. More recently, changes in the cationic concentration of xylem sap have been suggested to be responsible for short-term changes in K(XYL) based on data for 35 dicot species, and very few gymnosperms and ferns, indicating that xylem water transport may no longer be considered as an entirely passive process. Recent studies have revealed that this so-called ionic effect: (i) varies from little or no increase to >30%, (ii) is species specific, (iii) changes on a seasonal basis, (iv) depends on the cationic concentration, (v) is enhanced in embolized stems, and (vi) is positively correlated with vessel grouping. Furthermore, the ionic effect has been suggested to play functional roles in planta with respect to: (i) phloem-mediated control of xylem hydraulic properties, (ii) compensation of cavitation-induced loss of hydraulic conductance, with the result of optimizing light and water utilization, and (iii) differential regulation of water delivery to branches exposed to different levels of light. Pits are likely to play a key role in the ionic effect, which has largely been explained as a consequence of the poly-electrolytic nature and hydrogel properties of the pectic matrix of interconduit pit membranes, despite little evidence that pit membrane pectins remain present after cell hydrolysis. More research is needed to address the ionic effect in more species, physico-chemical properties of pit membranes, and how the ionic effect may increase xylem hydraulic conductance 'on demand'. PMID:21765173

Nardini, Andrea; Salleo, Sebastiano; Jansen, Steven

2011-07-16

397

Seismic Source Characteristics of Nuclear Explosions in Water-filled Cavities  

NASA Astrophysics Data System (ADS)

- During the period from 1975 to 1979, the former Soviet Union conducted a series a six nuclear explosions in a water-filled cavity in salt which was created in 1968 by a tamped 27kt explosion at a depth of 597m at the Azgir test site at the north end of the Caspian Sea. Broadband, near-regional seismic data recorded from these tests have been processed and analyzed in an attempt to characterize the seismic source characteristics of these explosions and assess their relevance to the cavity decoupling evasion scenario. The results of these analyses indicate that the explosions in the water-filled cavity were not decoupled, but rather show evidence of enhanced seismic coupling with respect to that which would be expected from tamped explosions of the same yields in salt. Theoretical finite difference simulations of these tests have been conducted in which the complex, nonlinear interactions between the shock effects in both the water and surrounding salt medium have been explicitly modeled. The results of these simulations indicate that the most prominent yield dependent features of the observed seismic source functions can be largely explained by the dynamic interactions between the expanding and contracting steam bubbles generated by the explosions in water and the shock-wave reflections from the cavity wall. More specifically, it has been found that the shock-wave reflection from the cavity wall retards the expansion of the steam bubble in a yield dependent fashion relative to that expected in the open ocean, resulting in a smaller maximum bubble radius and a shorter bubble oscillation period.

Murphy, J. R.; Sultanov, D. D.; Rimer, N.; Barker, B. W.

398

Mercury levels in walleyes from Wisconsin lakes of different water and sediment chemistry characteristics  

SciTech Connect

Forty-three lakes throughout Wisconsin were sampled in 1985-86 to determine the water and sediment chemistry characteristics that were associated with elevated concentrations of mercury in walleyes. Mean mercury concentrations for each of three different length classes of walleyes increased as the parameters lake pH, alkalinity, calcium, conductivity, or chlorophyll-a decreased. Low values for these parameters characterized most lakes in northern Wisconsin. Mean mercury concentrations exceeded the Wisconsin health standard of 0.5 micrograms (ug) Hg/g wet weight of fish for all walleye length classes in lakes with pH values < 6.0, for walleyes > or = to 15.0 inches in lakes with pH 6.0-6.9, and for walleyes > or = 20.0 in. in all lake pH categories. Apparently the older, larger walleyes in hard water as well as soft water lakes can accumulate enough mercury to warrant concern. Sediment mercury concentrations were generally < or = 0.02 ug/g dry weight for all study lakes, but sediment mercury and organic matter were higher in lakes with pH values < 7.0 than in lakes with pH > or = 7.0. Models were developed and tested to predict mercury concentrations in a 17-in. walleye for each lake. The best model derived from the study and tested on an independent dataset used alkalinity and calcium as independent variables. Clearly, walleyes from soft water, poorly buffered, low pH lakes have the highest concentrations of mercury, but the reasons for these higher concentrations require further study. 67 refs., 5 figs., 27 tabs.

Lathrop, R.C.; Noonan, K.C.; Guenther, P.M.; Brasino, T.L.; Rasmussen, P.W.

1989-01-01

399

Physiological and ecological implications of coupled heat and water transport mechanisms of endotherms and tundra vegetation. Progress report  

SciTech Connect

This research seeks to extend a current quantitative general heat and mass transfer model developed for the porous insulation of endotherms to include the porous media of tundra vegetation, to test the model's predictions for endotherm heat generation requirements and water loss rates for different insulations under conditions measured in the laboratory and in the field on various inanimate objects and live endotherms, and to integrate the porous media model with microclimate models to calculate heat and mass fluxes through the low canopies of tundra vegetation and the soil. 9 refs., 6 figs.

Porter, W.P.; Stewart, W.E.

1986-01-01

400

Physiological traits of Penicillium glabrum strain LCP 08.5568, a filamentous fungus isolated from bottled aromatized mineral water.  

PubMed

Penicillium glabrum is a ubiquitous fungus distributed world wide. This fungus is a frequent contaminant in the food manufacturing industry. Environmental factors such as temperature, water activity and pH have a great influence on fungal development. In this study, a strain of P. glabrum referenced to as LCP 08.5568, has been isolated from a bottle of aromatized mineral water. The effects of temperature, a(w) and pH on radial growth rate were assessed on Czapeck Yeast Agar (CYA) medium. Models derived from the cardinal model with inflection [Rosso et al., 1993 An unexpected correlation between cardinal temperatures of microbial growth highlighted by a new model. J. Theor. Bio. 162, 447-463.] were used to fit the experimental data and determine for each factor, the cardinal parameters (minimum, optimum and maximum). Precise characterisation of the growth conditions for such a fungal contaminant, has an evident interest to understand and to prevent spoilage of food products. PMID:19233496

Nevarez, L; Vasseur, V; Le Madec, A; Le Bras, M A; Coroller, L; Leguérinel, I; Barbier, G

2009-01-23

401

Variability of deep water mass characteristics in the North Aegean Sea: The role of lateral inputs and atmospheric conditions  

NASA Astrophysics Data System (ADS)

The North Aegean Sea is considered as one of the major dense water formation sites of the Eastern Mediterranean Sea, contributing to the renewal of the Mediterranean deep water masses. We investigate the variability of the deeper water mass characteristics during the period 2002-2008, employing the Hybrid Coordinate Ocean Model for the North Aegean region. Two significant dense water formation events were detected, and the role of the major lateral water inputs, namely waters of Levantine Sea and Black Sea origin, was investigated. Atmospheric conditions were identified as the main factor of dense water formation during 2003, when strong buoyancy loss due to the low winter temperatures produced new dense water masses in the surface and intermediate layers (<400 m). During 2006, it was the intrusion of more saline Levantine waters that increased the sigma-theta of the south North Aegean region, creating idealized conditions for a potential greater dense water formation event. The Black Sea Waters spreading may affect the Mixed Layer Depth variability, promoting the stratification of the water column and playing a vital role on the dense water formation activity, working against the open-sea convection of denser waters.

Androulidakis, Yannis S.; Kourafalou, Vassiliki H.; Krestenitis, Yannis N.; Zervakis, Vassilis

2012-09-01

402

Pressure Drop Characteristics in Tight-Lattice Bundles for Reduced-Moderation Water Reactors  

NASA Astrophysics Data System (ADS)

The reduced-moderation water reactor (RMWR) consists of several distinctive structures; a triangular tight-lattice configuration and a double-flat core. In order to design the RMWR core from the point of view of thermal-hydraulics, an evaluation method on pressure drop characteristics in the rod bundles at the tight-lattice configuration is required. In this study, calculated results by the Martinelli-Nelson's and Hancox's correlations were compared with experimental results in 4×5 rod bundles and seven-rod bundles. Consequently, the friction loss in two-phase flows becomes smaller at the tight-lattice configuration with the hydraulic diameter less than about 3mm. This reason is due to the difference of the configuration between the multi-rod bundle and the circular tube and due to the effect of the small hydraulic diameter on the two-phase multiplier.

Tamai, Hidesada; Kureta, Masatoshi; Yoshida, Hiroyuki; Akimoto, Hajime

403

A comprehensive analysis of the physiological and anatomical components involved in higher water loss rates after leaf development at high humidity.  

PubMed

To better understand the poor regulation of water loss after leaf development at high relative air humidity (RH), the relative importance of the physiological and anatomical components was analyzed focusing on cultivars with a contrasting sensitivity to elevated RH. The stomatal responsiveness to three closing stimuli (desiccation, abscisic acid feeding, light/dark transition), as well as several stomatal features (density, index, size and pore dimensions) and the cuticular transpiration rate (CTR) were determined in four rose cultivars, grown under moderate (60%) and high (95%) RH. Moreover, the effects of changes in stomatal density and pore dimensions on the stomatal conductance (gs) were quantified using a modified version of the Brown and Escombe equation. Higher water loss, as a result of plant growth at high RH, was primarily caused by an increase in residual gs, and to a lesser extent due to higher CTR. It was estimated that in leaflets subjected to desiccation the enhanced gs in high RH- as compared to moderate RH-grown plants was mostly due to poor stomatal functionality and to a lesser extent the combined result of higher stomatal density and longer pore length. It is concluded that the reduced degree and, specially, the reduced rate of stomatal closure are the primary causes of the large genotypic variation in the control of water loss in high RH-grown plants. Furthermore, it was found that although changes in stomatal length have no influence on stomatal functionality, changed anatomical features per se represent a significant and direct contribution to the increased water loss. PMID:23474196

Fanourakis, Dimitrios; Heuvelink, Ep; Carvalho, Susana M P

2013-03-06

404

Physiological Ecology  

Microsoft Academic Search

After having unfolded the principal potentials of photosynthesis in Clusia in Chap. 8 we will now look at its performance at the plant community level. The simple single morphotype of Clusia gains diversity by the various life forms it produces (Sect. 2.3) and by its high physiological and biochemical plasticity\\u000a (Chap. 8). Clusia is extraordinarily successful in various tropical habitats

Ulrich Lüttge

405

Physiological Interactions  

Microsoft Academic Search

\\u000a Improvement in both temporal and spatial resolution of MDCT has brought the ability to explore both the heart and lung within\\u000a a single examination and opened the field of functional evaluation. However, interactions between heart and lung have long\\u000a been identified as important physiological phenomena in pathology (Pinsky 2005). For the radiologist, they are involved in difficulties of interpretation in

Francois Laurent; Michel Montaudon

406

Muscle Physiology  

NSDL National Science Digital Library

The Muscle Physiology Lab at the University of California-San Diego provides this comprehensive source of information on the neuromuscular system. The Web site appears as a extensive menu of subtopics, each leading to pages of detailed text and diagrams. Students studying muscle structure and function should find this well-organized and authoritative resource extremely useful. The Web site also includes a search tool for quickly finding pages of interest, and a list of related links for additional information.

2000-01-01

407

Interacting effects of elevated temperature and additional water on plant physiology and net ecosystem carbon fluxes in a high Arctic ecosystem  

NASA Astrophysics Data System (ADS)

Arctic ecosystems are experiencing temperature increases more strongly than the global average, and increases in precipitation are also expected amongst the climate impacts on this region in the future. These changes are expected to strongly influence plant physiology and soil biogeochemistry with subsequent implications for system carbon balance. We have investigated the effects of a long-term (10 years) increase in temperature, soil water and the combination of both on a tundra ecosystem at a field manipulation experiment in NW Greenland. Leaf gas exchange, chlorophyll fluorescence, carbon (C) and nitrogen (N) content and leaf isotopic composition, and leaf morphology were measured on Salix arctica plants in treatment and control plots in June-July 2011, and continuous measurements of net plant and soil fluxes of CO2 and water were made using automatic chambers coupled to a trace gas laser analyzer. Plants in the elevated temperature (T2) treatment had the highest photosynthetic capacity in terms of net CO2 assimilation rates and photosystem II efficiencies, and lowest rates of non-photochemical energy dissipation during photosynthesis. T2 plants also had the highest leaf N content, specific leaf area (SLA) and saturation light level of photosynthesis. It appears that warming increases soil N availability, which the plants direct towards increasing photosynthetic capacity and producing larger thinner leaves. On the other hand, the plants in the plots with both elevated temperatures and additional water (T2W) had the lowest photosystem II efficiencies and the highest rates of non-photochemical energy dissipation, due more to higher levels of constitutive energy dissipation than regulated thermal quenching. Watering, both in combination with higher temperatures and alone (W treatment), also reduced leaf SLA and leaf N relative to control plots. However, net photosynthetic rates remained similar to control plants, due in part to higher stomatal conductance (W) and lower dark respiration rates (T2W). However, net ecosystem fluxes were highest in the T2W plots due to 35% increase in leaf area. Total growing season C accumulation was 3-5 times greater, water fluxes were 1.5-2 times higher, and water use efficiency was about 3 times higher in the combined treatment than the control. Net carbon and water fluxes in the elevated temperature plots were similar to the control plots, possibly indicating that enhanced soil respiration may balance increased photosynthetic uptake. The influence of climatic change on system C budgets and ecosystem-atmosphere fluxes in the high arctic systems clearly depends on the interaction between plant strategies, soil responses and the impact of multiple climatic drivers.

Maseyk, Kadmiel; Seibt, Ulrike; Lett, Céline; Lupascu, Massimo; Czimczik, Claudia; Sullivan, Patrick; Welker, Jeff

2013-04-01

408

Land and water use characteristics in the vicinity of the Savannah River Site  

SciTech Connect

Routine operations at the Savannah River Site (SRS) result in the release of small amounts of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the offsite maximum individual and the offsite population within 50 miles of the SRS are estimated on a yearly basis. These estimates are generated using dose models prescribed for the commercial nuclear power industry by the Nuclear Regulatory Commission (NRC). The NRC provides default values for dose model parameters for facilities not having enough data to develop site-specific values. A survey of land and water use characteristics for the Savannah River area has been conducted to determine as many site-specific values as possible for inclusion in the dose models used at the SRS. These site parameters include local characteristics of meat, milk, and vegetable production; river recreational activities; and meat, milk, and vegetable consumption rates. The report that follows describes the origin of the NRC default values, the methodology for deriving regional data, the results of the study, and the derivations of region-specific usage and consumption rates. 33 refs., 3 figs., 8 tabs.

Hamby, D.M.

1991-03-01

409

Cementation characteristics and age of beachrocks in a fresh-water environment, Lake ?znik, NW Turkey  

NASA Astrophysics Data System (ADS)

This paper focuses on the cement characteristics and optical luminescence age of late Pleistocene-Holocene beachrock, exposed on the southeast shore of freshwater Lake ?znik in northwest Turkey, based on field observations, various spectroscopic analyses and optical dating results. The studied beachrock is a poorly-sorted coastal conglomerate composed mostly of gravels derived from surrounding volcanic rocks and marbles as well as quartz and carbonate grains. We identified different types of cements; dominated by micritic envelopes, bladed isopachous aragonite rims, void fills, radial aggregates and meniscus bridges, implying no single origin. Cementation characteristics indicate that marine-like cement micro-fabrics may occur in freshwater lake environments where the lake-water chemistry favors carbonate precipitation. OSL data revealed the existence of older beachrock dating back to 20.2 ka, together with younger Holocene-age beachrock of between 5.6 and 2.4 ka. This suggests that younger beachrocks have been superimposed on older cemented carbonates through the removal of carbonates by wave motion (splash and spray) during lower lake level conditions.

Erginal, Ahmet Evren; K?yak, Nafiye Güneç; Öztürk, Muhammed Zeynel; Avc?o?lu, Mustafa; Bozcu, Mustafa; Yi?itba?, Erdinç

2012-01-01

410

Seasonal change characteristics in water discharge and quality of flowing wells in the Kurobe River alluvial fan, Japan  

NASA Astrophysics Data System (ADS)

The overall goal of this study is to promote sustainable groundwater use in the Kurobe River alluvial fan (KRAF), Japan. To do so, the present condition of groundwater in the KRAF must be understood. To clarify the characteristics and seasonal changes of flowing wells in the KRAF, regular field observations were undertaken for 18 months from March 2011. The results regarding seasonal changes in flowing water discharges, water quality, and isotope ratios have been reported in this paper. This paper newly reports the monthly discharge and water quality of flowing wells in the KRAF. Discharge flow was observed at 10-minute intervals to clarify the variability. Moreover, seasonal changes and spatial characteristics of discharge were clarified for the whole study area. The analyses showed no spatial differences in water quality, in agreement with previous research. Furthermore, fundamental water quality variables (Na, K, Mg, Ca, Cl, and SO4) had not changed substantially from values reported in 1989. Isotope ratio analysis indicated that 3 observation wells had difference sources of recharge than the other wells that were recharged by the Kurobe River. This pattern also agrees with results published 10 years ago. Spatial characteristics also had the same patterns as previously reported. Finally, as mentioned above, although there are many published reports of water quality in flowing wells in the KRAF, few studies have examined water discharge. To accurately estimate the groundwater conditions in the KRAF, continued, long-term monitoring of water flow in wells is needed.

Tebakari, Taichi

2013-04-01

411

Runoff and water-quality characteristics of surface-mined lands in Illinois  

SciTech Connect

Seven watersheds - three in western Illinois (Fulton County), two in southwestern Illinois (St. Clair County), and two in southern Illinois (Williamson County) - were selected to assess the effect of surface mining on the quality and quantity of surface runoff. Each area had one site draining an unmined basin and a nearby site(s) draining a partly surface-mined basin. Data from the literature, file data collected prior to 1979, and streamflow and water-quality data collected from 1977 to 1979 as part of this study, were used to assess runoff characteristics. Flow-duration curves for streams draining surface-mined land had lower variability than those for streams draining unmined land. By adjusting an index of variability, according to the percentage of surface-mined land in a basin, conventional techniques can be used to develop synthetic flow-duration curves. Surface mining changes basin characteristics such that peak flows are decreased and low flows are increased. Regression equations were developed that relate storm runoff volume and peak discharge to basin characteristics and climatologic data. Concentrations of dissolved solids, sulfate, and calcium were higher in streams draining areas that were extensively mined than in streams draining areas where mining has been minimal. Different mined areas in Illinois yield different concentrations of these substances. Harmonic analyses of stream temperatures showed higher harmonic means and lower amplitudes in surface-mined basins. Surface-mined basins had lower suspended-sediment yields than unmined basins. Trace-element concentrations were similar in streams in mined and unmined basins provided in-place neutralization by alkaline material had taken place in mined basins. 20 refs., 30 figs., 14 tabs.

Brabets, T.P.

1984-01-01

412

Insights into the Physiology and Ecology of the Brackish-Water-Adapted Cyanobacterium Nodularia spumigena CCY9414 Based on a Genome-Transcriptome Analysis  

PubMed Central

Nodularia spumigena is a filamentous diazotrophic cyanobacterium that dominates the annual late summer cyanobacterial blooms in the Baltic Sea. But N. spumigena also is common in brackish water bodies worldwide, suggesting special adaptation allowing it to thrive at moderate salinities. A draft genome analysis of N. spumigena sp. CCY9414 yielded a single scaffold of 5,462,271 nucleotides in length on which genes for 5,294 proteins were annotated. A subsequent strand-specific transcriptome analysis identified more than 6,000 putative transcriptional start sites (TSS). Orphan TSSs located in intergenic regions led us to predict 764 non-coding RNAs, among them 70 copies of a possible retrotransposon and several potential RNA regulators, some of which are also present in other N2-fixing cyanobacteria. Approximately 4% of the total coding capacity is devoted to the production of secondary metabolites, among them the potent hepatotoxin nodularin, the linear spumigin and the cyclic nodulapeptin. The transcriptional complexity associated with genes involved in nitrogen fixation and heterocyst differentiation is considerably smaller compared to other Nostocales. In contrast, sophisticated systems exist for the uptake and assimilation of iron and phosphorus compounds, for the synthesis of compatible solutes, and for the formation of gas vesicles, required for the active control of buoyancy. Hence, the annotation and interpretation of this sequence provides a vast array of clues into the genomic underpinnings of the physiology of this cyanobacterium and indicates in particular a competitive edge of N. spumigena in nutrient-limited brackish water ecosystems.

Voss, Bjorn; Bolhuis, Henk; Fewer, David P.; Kopf, Matthias; Moke, Fred; Haas, Fabian; El-Shehawy, Rehab; Hayes, Paul; Bergman, Birgitta; Sivonen, Kaarina; Dittmann, Elke; Scanlan, Dave J.; Hagemann, Martin; Stal, Lucas J.; Hess, Wolfgang R.

2013-01-01

413

Predicting physical and chemical water properties from relationships with watershed soil characteristics.  

PubMed

The Surface Waters component of the Environmental Monitoring and Assessment Program (EMAPSW) was developed by the USEPA to evaluate the extent and condition of lakes and streams over national and regional scales. Realistically, chemical or physical water properties (WPs) such as acidity or turbidity can be field-sampled for only a small portion of all lakes and streams. However, soil characteristics (SCs) affect WPs and broad-scale soil survey data have become available in the State Soil Geographic Data Base (STATSGO). We developed models relating observed WPs to SCs to extrapolate the sampled WPs to a region, potentially reducing extensive monitoring needs. Our study region consisted of 13 northeastern and Mid-Atlantic states and contained 882 STATSGO soil map units. We used map units as the spatial component of WP analysis. The WPs were sampled in 721 randomly selected EMAPSW study sites. The watersheds of these sites represent 7.1% of the region's total area and spatially intersect 400 of its soil map units. Each intersected map unit was assigned the weighted average WPs from the corresponding watersheds. Conditional expectation models were used to extrapolate sampled WPs to 882 map units. The relative standard errors ranged from low for pH (0.8%), intermediate for total P (12.1%), and very high for chloride (54.8%). The high extrapolation errors indicate outlier conditions from natural, non-soil, or anthropogenic sources. PMID:11215642

Shirazi, M A; Boersma, L; Johnson, C B; Haggerty, P K

414

Water Purification Characteristic of the Actual Constructed Wetland with Carex dispalata in a Cold Area  

NASA Astrophysics Data System (ADS)

Carex dispalata, a native plant species applied in cold districts for water purification in constructed wetlands, has useful characteristics for landscape creation and maintenance. In this study, seasonal differences in purification ability were verified, along with comparison of frozen and non-frozen periods' performance. A wetland area was constructed using a “hydroponics method” and a “coir fiber based method”. Results show that the removal rates of BOD, SS, and Chl-a were high. On this constructed wetland reduces organic pollution, mainly phytoplankton, but the removal of nitrogen and phosphorus was insufficient. The respective mean values of influent and treated water during three years were 26.6 mg/L and 12.2 mg/L for BOD, and 27.9 mg/L and 7.5 mg/L for SS. The mean value of the BOD removal rate for the non-frozen period was 2.99 g/m2/d that for the frozen period was 1.86 g/m2/d. The removal rate followed the rise of the BOD load rate. The removal rate limits were about 4 g/m2/d during the frozen period and 15 g/m2/d during the non-frozen period. For operations, energy was unnecessary. The required working hours were about 20 h annually for all maintenance and management during operations.

Tsuji, Morio; Yamada, Kazuhiro; Hiratsuka, Akira; Tsukada, Hiroko

415

Suspended-sediment characteristics for the Johnson Creek basin, Oregon, water years 2007-10  

USGS Publications Warehouse

Significant Findings An analysis of suspended-sediment transport in the Johnson Creek basin, Oregon, during water years 2007–10 indicated that: Streamflow characteristics for the 4 years of study were not extremely dry or wet, and represented near-average conditions. Computed average annual suspended-sediment loads were 1,890 and 4,640 tons at the Gresham and Milwaukie stations, respectively. More than 70 percent of suspended-sediment transport in the watershed occurred during the high-flow months of November, December, and January. Less than 10 percent of suspended-sediment transport in the watershed occurred during April–October. About 50 percent of all suspended-sediment load is transported during the highest 1 percent of streamflows. The January 2009 streamflow peak was the third highest in the 70-year record for Johnson Creek. About 50 percent of suspended-sediment transport in water year 2009 occurred in January. The drainage area upstream of the Gresham streamflow-gaging station constitutes about 30 percent of the drainage area at the Milwaukie station, but accounted for about 40 percent of the suspended sediment and 45 percent of the streamflow at the Milwaukie station. On an annual basis, most of the higher sediment yield at the Gresham station, relative to the Milwaukie station, can be explained by the higher streamflow yield at the Gresham station rather than by higher suspended-sediment concentration.

Stonewall, Adam J.; Bragg, Heather M.

2012-01-01

416

Gradients of salinity stress, environmental stability and water chemistry as a templet for defining habitat types and physiological strategies in inland salt waters  

Microsoft Academic Search

The search for pattern in the geographic occurrence of salt lake flora and fauna often reveals strong associations of specific taxa with certain types of water chemistry. Solute composition, along with salinity and habitat stability, may provide a templet shaping the distribution of many organisms inhabiting saline lakes. A review of studies demonstrating habitat associations, specific solute tolerance, and ionic

David B. Herbst

2001-01-01

417

Neutron transport with the method of characteristics for 3-D full core boiling water reactor applications  

NASA Astrophysics Data System (ADS)

The Numerical Nuclear Reactor (NNR) is a code suite that is being developed to provide high-fidelity multi-physics capability for the analysis of light water nuclear reactors. The focus of the work here is to extend the capability of the NNR by incorporation of the neutronics module, DeCART, for Boiling Water Reactor (BWR) applications. The DeCART code has been coupled to the NNR fluid mechanics and heat transfer module STAR-CD for light water reactor applications. The coupling has been accomplished via an interface program, which is responsible for mapping the STAR-CD and DeCART meshes, managing communication, and monitoring convergence. DeCART obtains the solution of the 3-D Boltzmann transport equation by performing a series of 2-D modular ray tracing-based method of characteristics problems that are coupled within the framework of 3-D coarse-mesh finite difference. The relatively complex geometry and increased axial heterogeneity found in BWRs are beyond the modeling capability of the original version of DeCART. In this work, DeCART is extended in three primary areas. First, the geometric capability is generalized by extending the modular ray tracing scheme and permitting an unstructured mesh in the global finite difference kernel. Second, numerical instabilities, which arose as a result of the severe axial heterogeneity found in BWR cores, have been resolved. Third, an advanced nodal method has been implemented to improve the accuracy of the axial flux distribution. In this semi-analytic nodal method, the analytic solution to the transverse-integrated neutron diffusion equation is obtained, where the nonhomogeneous neutron source was first approximated by a quartic polynomial. The successful completion of these three tasks has allowed the application of the coupled DeCART/STAR-CD code to practical BWR problems.

Thomas, Justin W.

418

Effects of sodium bicarbonate and albumin on the in vitro water-holding capacity and some physiological properties of Trigonella foenum graecum L. galactomannan in rats.  

PubMed

This study seeks to improve the beneficial effects of fenugreek (Trigonella foenum graecum L.) galactomannan (GM) in lowering the plasma lipid profile and weight. Three different combinations of diets were prepared with fenugreek GM--(a) fenugreek GM + water (GM); (b) fenugreek GM + sodium bicarbonate (GMB); and (c) fenugreek GM + bicarbonate + albumin (GMBA)--and their in vitro water retention capacity and in vivo lipid-lowering effect were studied. Distilled water and sodium bicarbonate were used as controls. The sodium bicarbonate significantly increased the in vitro water-holding capacity of fenugreek GM (49.1 +/- 8.7 vs. 21.6 +/- 0.9 g of water/g of dry weight, P < .01). Administration by oral intubation of the combination GMBA to male albino Wistar rats (250 mg/kg of body weight) over a 4-week period was the most effective in reducing body weight (-27.0 +/- 0.4%, P < .001). Within this period, the combinations GMBA and GMB brought about the most significant reduction in the levels of plasma total cholesterol (P < .005). The GMBA combination was also the most effective in reducing levels of plasma low-density lipoprotein cholesterol (P < .001) and the atherogenicity indices. GM, GMB, and GMBA brought about significant (P < .01, .001, and .001, respectively) increases in the plasma high-density lipoprotein cholesterol levels, with the highest increase coming with GMBA. A significant increase in plasma triglycerides (P < .05) was brought about by the GMBA combination, probably resulting from the rapid reduction of body weight observed. Food intake was reduced by GM, GMB, and GMBA, while water intake increased in that order. The GMB combination significantly reduced transit time (P < .01) compared to GM. On the other hand, GMB and GMBA improved glycemic control, compared to GM. We conclude that albumin and sodium bicarbonate have the ability to improve some beneficial physiological effects of fenugreek GM. This finding could have applications in the areas of human obesity, weight loss, and the control of blood lipids. PMID:17472483

Dakam, William; Shang, Judith; Agbor, Gabriel; Oben, Julius

2007-03-01

419

Hydrogeology and water-quality characteristics of the Lower Floridan aquifer in east-central Florida  

USGS Publications Warehouse

The hydrogeology and water-quality characteristics of the Lower Floridan aquifer and the relation of the Lower Floridan aquifer to the framework of the Floridan aquifer system were evaluated during a 6-year (1995-2001) study. The study area, a 7,500 square-mile area of east-central Florida, is underlain by three principal hydrogeologic units: the surficial aquifer system, the intermediate confining unit, and the Floridan aquifer system. The Floridan aquifer system, a carbonate-rock aquifer system composed of the Upper Floridan aquifer, a middle semiconfining unit, a middle confining unit, and the Lower Floridan aquifer, is the major source of water supply to east-central Florida. The Upper Floridan aquifer provides much of the water required to meet the current (2002) demand; however, the Lower Floridan aquifer is being used increasingly as a source of freshwater, particularly for municipal needs. For this reason, a better understanding of the aquifer is needed. The Lower Floridan aquifer is present throughout east-central Florida. The aquifer is composed of alternating beds of limestone and dolomite, and is characterized by abundant fractured dolomite zones and solution cavities. The altitude of the top of the Lower Floridan aquifer ranges from less than 600 feet below sea level in the northern part of the study area to more than 1,600 feet below sea level in the southwestern part. Thickness of the unit ranges from about 910 to 1,180 feet. The top of the Lower Floridan aquifer generally is marked by an increase in formation resistivity and by an increase in the occurrence of fractures and solution cavities within the carbonates. Also, a noticeable increase in borehole flow often marks the top of the unit. The bottom of the Lower Floridan aquifer is based on the first occurrence of evaporites. Ground-water in the Lower Floridan aquifer generally moves in a southwest-to-northeast direction across the study area. In September 1998, the altitude of the potentiometric surface of the Lower Floridan aquifer ranged from about 16 to 113 feet above sea level, and altitudes in May 1999 were about 2 to 7 feet lower than those measured in September 1998. The potentiometric surface of the Floridan aquifer system is constantly fluctuating, mainly in response to seasonal variations in rainfall and ground-water withdrawals. Seasonal fluctuations in the Lower Floridan aquifer typically range from about 2 to 10 feet. Water samples from 50 Lower Floridan aquifer wells were collected during this study. Most samples were analyzed in the field for temperature, pH, and specific conductance, and in the laboratory for major cations and anions. Specific conductance ranged from 147 to 6,710 microsiemens per centimeter. Chloride concentrations ranged from 3.0 to 2,188 milligrams per liter; sulfate concentrations ranged from 0.2 to 750 milli-grams per liter; and hardness ranged from 69 to 940 milligrams per liter. Water was least mineralized in the recharge areas of the Lower Floridan aquifer in the western part of the study area. The most mineralized water in the Lower Floridan aquifer occurred along parts of the Wekiva and St. Johns Rivers and in much of the eastern and southern parts of the study area. The altitude of the base of freshwater in the Floridan aquifer system (where chloride concentrations are equal to 250 milligrams per liter) is variable throughout the study area. The estimated position of the 250 milligram per liter isochlor surface is less than 200 feet below sea level in much of the eastern part of the study area, including the areas along the St. Johns River in Lake, Seminole, and Volusia Counties and near the Wekiva River in western Seminole County. The altitude of the 250 milligram per liter isochlor exceeds 3,000 feet below sea level in the extreme southwestern part of the study area.

O'Reilly, Andrew M.; Spechler, Rick M.; McGurk, Brian E.

2002-01-01

420

Cold Water Patches in Warm Streams: Physicochemical Characteristics and the Influence of Shading  

Microsoft Academic Search

Discrete cold water patches within the surface waters of summer warm streams afford potential thermal refuge for cold water fishes during periods of heat stress. This analysis focused on reach scale heterogeneity in water temperatures as influenced by local influx of cooler subsurface waters. Using field thermal probes and recording thermistors, we identified and characterized cold water patches (at least

Joseph L. Ebersole; William J. Liss; Christopher A. Frissell

2003-01-01

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