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Sample records for severe fluid retention

  1. Fluid Resuscitation in Severe Sepsis.

    PubMed

    Loflin, Rob; Winters, Michael E

    2017-02-01

    Since its original description in 1832, fluid resuscitation has become the cornerstone of early and aggressive treatment of severe sepsis and septic shock. However, questions remain about optimal fluid composition, dose, and rate of administration for critically ill patients. This article reviews pertinent physiology of the circulatory system, pathogenesis of septic shock, and phases of sepsis resuscitation, and then focuses on the type, rate, and amount of fluid administration for severe sepsis and septic shock, so providers can choose the right fluid, for the right patient, at the right time.

  2. Retention Severity in the Navy: A Composite Index.

    DTIC Science & Technology

    1983-06-01

    7 - 132 875 RETENTION SE VERITY IN THE N VY COMPOSITE INDEX(U) 1/2 NAVAL POSTGRADUATE SCHOOL MONTEREY CH M A DRIGGERS JUN 83 UNCLASSIFIED F/G5/9...SCHOOL NJ Monterey, California DTICS ELECTE ,1 SEIP26 193V THESIS " RETENTION SEVERITY IN THE NAVY: A COMPOSITE INDEX by *Michael A. Driggers, I June...8217$ CATALOG NUMBER2 4. TITLE (And *ubtfife) S. TYPE Of REPORT & PERIOD COVERED Retention Severity in the Navy: Master’s Thesis; A Composite Index June

  3. Retention of fluid and particles in captive tapirs (Tapirus sp.).

    PubMed

    Clauss, Marcus; Lang-Deuerling, Stefanie; Müller, Dennis W H; Kienzle, Ellen; Steuer, Patrick; Hummel, Jürgen

    2010-09-01

    The retention of ingesta in the digestive tract is a major characteristic of herbivorous animals. We measured particle and fluid mean retention times (MRT) in 13 lowland tapirs (Tapirus terrestris) and 5 Malayan tapirs (Tapirus indicus) from five zoological institutions on their usual zoo diet and 2 lowland and 4 Malayan tapirs additionally on roughage-only diets (total n of trials=24) with cobalt-EDTA as fluid and chromium-mordanted fibre (<2 mm) as particle markers. MRT for fluid and particles averaged 42+/-16 h and 55+/-18 h in lowland and 40+/-13 h and 56+/-14 h in Malayan tapirs. In a General Linear Model, neither Tapir species, body mass or diet (characterised by the proportion of roughage) was significantly related to MRT, but dry matter intake was, with a steep decline in MRT with higher intake levels. Compared to other hindgut fermenters, tapirs have a low defecation frequency, which might be linked to their comparatively low food intake. Their gastrointestinal capacity (in dry matter: 1.63+/-0.63% of body mass) is similar to that calculated for horses. A comparison of the difference in fluid and particle MRT in large hindgut fermenters (horses, rhinoceroses, elephants, and the tapirs of this study) shows that longer absolute particle MRT are linked to shorter relative fluid MRT, possibly indicating a more thorough 'washing' of particulate ingesta with digestive fluids at longer particle MRT. The only outlier to this general pattern, with an exceptionally high difference between fluid and particle MRT, indicating a particularly efficient ingesta washing, is the white rhinoceros (Ceratotherium simum). If possible, results of this study should be compared to findings in tapirs on natural diets.

  4. An unsteady state retention model for fluid desorption from sorbents.

    PubMed

    Bazargan, Alireza; Sadeghi, Hamed; Garcia-Mayoral, Ricardo; McKay, Gordon

    2015-07-15

    New studies regarding the sorption of fluids by solids are published every day. In performance testing, after the sorbent has reached saturation, it is usually removed from the sorbate bath and allowed to drain. The loss of liquid from the sorbents with time is of prime importance in the real-world application of sorbents, such as in oil spill response. However, there is currently no equation used for modeling the unsteady state loss of the liquid from the dripping sorbent. Here, an analytical model has been provided for modeling the dynamic loss of liquid from the sorbent in dripping experiments. Data from more than 60 sorbent-sorbate systems has been used to validate the model. The proposed model shows excellent agreement with experimental results and is expressed as: U(t)=U(L)e(-Kt)+U(e) In which U(t) (kg/kg) is the uptake capacity of the sorbent at any time t (s) during dripping, U(L) (kg/kg) is the uptake capacity lost due to dripping, and U(e) (kg/kg) is the equilibrium uptake capacity reached after prolonged dripping. K (1/s) is defined as the Kamaan coefficient and controls the curvature of the retention profile. Kamaan ([symbol: see text] IPA phonetics: kæmɒn) is an Iranian (Farsi/Persian) word meaning "arc" or "curve" and hence the letter K has been designated.

  5. Urinary Analysis of Fluid Retention in the General Population: A Cross-Sectional Study

    PubMed Central

    Grankvist, Nina; Krizhanovskii, Camilla

    2016-01-01

    Objective Renal conservation (retention) of fluid might affect the outcome of hospital care and can be indicated by increased urinary concentrations of metabolic waste products. We obtained a reference material for further studies by exploring the prevalence of fluid retention in a healthy population. Methods Spot urine sampling was performed in 300 healthy hospital workers. A previously validated algorithm summarized the urine-specific gravity, osmolality, creatinine, and color to a fluid retention index (FRI), where 4.0 is the cut-off for fluid retention consistent with dehydration. In 50 of the volunteers, we also studied the relationships between FRI, plasma osmolality, and water-retaining hormones. Results The cut-off for fluid retention (FRI ≥ 4.0) was reached by 38% of the population. No correlation was found between the FRI and the time of the day of urine sample collection, and the FRI was only marginally correlated with the time period spent without fluid intake. Volunteers with fluid retention were younger, generally men, and more often had albuminuria (88% vs. 34%, P < 0.001). Plasma osmolality and plasma sodium were somewhat higher in those with a high FRI (mean 294.8 vs. 293.4 mosmol/kg and 140.3 vs. 139.9 mmol/l). Plasma vasopressin was consistently below the limit of detection, and the plasma cortisol, aldosterone, and renin concentrations were similar in subjects with a high or low FRI. The very highest FRI values (≥ 5.0, N = 61) were always accompanied by albuminuria. Conclusion Fluid retention consistent with moderate dehydration is common in healthy staff working in a Swedish hospital. PMID:27764121

  6. Increased Milk Protein Concentration in a Rehydration Drink Enhances Fluid Retention Caused by Water Reabsorption in Rats.

    PubMed

    Ito, Kentaro; Saito, Yuri; Ashida, Kinya; Yamaji, Taketo; Itoh, Hiroyuki; Oda, Munehiro

    2015-01-01

    A fluid-retention effect is required for beverages that are designed to prevent dehydration. That is, fluid absorbed from the intestines should not be excreted quickly; long-term retention is desirable. Here, we focused on the effect of milk protein on fluid retention, and propose a new effective oral rehydration method that can be used daily for preventing dehydration. We first evaluated the effects of different concentrations of milk protein on fluid retention by measuring the urinary volumes of rats fed fluid containing milk protein at concentrations of 1, 5, and 10%. We next compared the fluid-retention effect of milk protein-enriched drink (MPD) with those of distilled water (DW) and a sports drink (SD) by the same method. Third, to investigate the mechanism of fluid retention, we measured plasma insulin changes in rats after ingesting these three drinks. We found that the addition of milk protein at 5 or 10% reduced urinary volume in a dose-dependent manner. Ingestion of the MPD containing 4.6% milk protein resulted in lower urinary volumes than DW and SD. MPD also showed a higher water reabsorption rate in the kidneys and higher concentrations of plasma insulin than DW and SD. These results suggest that increasing milk protein concentration in a beverage enhances fluid retention, which may allow the possibility to develop rehydration beverages that are more effective than SDs. In addition, insulin-modifying renal water reabsorption may contribute to the fluid-retention effect of MPD.

  7. Long-term retention of skilled visual search following severe traumatic brain injury

    PubMed Central

    PAVAWALLA, SHITAL P.; SCHMITTER-EDGECOMBE, MAUREEN

    2007-01-01

    We examined the long-term retention of a learned automatic cognitive process in 17 severe TBI participants and 10 controls. Participants had initially received extensive consistent-mapping (CM) training (i.e., 3600 trials) in a semantic category visual search task (Schmitter-Edgecombe & Beglinger, 2001). Following CM training, TBI and control groups demonstrated dramatic performance improvements and the development of an automatic attention response (AAR), indicating task-specific and stimulus-specific skill learning. After a 5- or 10-month retention interval, participants in this study performed a New CM task and the originally trained CM task to assess for retention of task-specific and stimulus-specific visual search skills, respectively. No significant group differences were found in the level of retention for either skill type, indicating that individuals with severe TBI were able to retain the learned skills over a long-term retention interval at a level comparable to controls. Exploratory analyses revealed that TBI participants who returned at the 5-month retention interval showed nearly complete skill retention, and greater skill retention than TBI participants who returned at the 10-month interval, suggesting that “booster” or retraining sessions may be needed when a skill is not continuously in use. PMID:17064444

  8. Treatment of diuretic-resistant fluid retention with ultrafiltration.

    PubMed

    Asaba, H; Bergström, J; Fürst, P; Shaldon, S; Wiklund, S

    1978-01-01

    Nine patients with diuretic-resistant edema, secondary to congestive heart failure, liver cirrhosis, or nephrotic syndrome, were treated with ultrafiltration using high water flux dialyzers. Access to the blood stream was obtained by femoral vein catheterization. As much as 8.3 kg of fluid were removed in 3--4 hours with only transient decline in blood pressure. The procedure was well tolerated and yielded immediate symptomatic relief. The potential for restoration of an edema-free state in patients with diuretic-resistant edema suggests that further experience with this technique is justified.

  9. Retention of infectious haematopoietic necrosis virus infectivity in fish tissue homogenates and fluids stored at three temperatures

    USGS Publications Warehouse

    Burke, J.; Mulcahy, D.

    1983-01-01

    Pools of brain, kidney, spleen, liver and gut tissues from several rainbow trout, Salmo gairdneri Richardson, and whole sockeye salmon, Oncorhynchus nerka (Walbaum), fry were homogenized with a known amount of infectious haematopoietic necrosis virus (IHNV). Virus was also added to ovarian fluids and sera pooled from several rainbow trout. The plaque assay was used to determine the retention of IHNV infectivity after different storage periods at 20°C, 4°C and -20°C. The work was used to evaluate homogenization as a remote field treatment of IHNV samples before shipment to the laboratory. Maintenance of viral infectivity varied widely among different homogenates and fluids. For short-term storage, 4°C was generally the most efficient temperature for preserving infectious virus in ovarian fluids, sera and homogenates of eggs, spleen, whole fry and brain, while infectivity was most efficiently preserved in kidney and liver homogenates by storage at -20°C. Infectious virus was not detected in any sample stored for one year at -20°C. Variations in retention of viral infectivity make homogenization of samples in the field followed by transfer to the laboratory unacceptable.

  10. Retention of infectious haematopoietic necrosis virus infectivity in fish tissue homogenates and fluids stored at three temperatures.

    USGS Publications Warehouse

    Burke, J.; Mulcahy, D.

    1983-01-01

    Pools of brain, kidney, spleen, liver and gut tissues from several rainbow trout, Salmo gairdneri Richardson, and whole sockeye salmon, Oncorhynchus nerka (Walbaum), fry were homogenized with a known amount of infectious haematopoietic necrosis virus (IHNV). Virus was also added to ovarian fluids and sera pooled from several rainbow trout. The plaque assay was used to determine the retention of IHNV infectivity after different storage periods at 20°C, 4°C and —20°C. The work was used to evaluate homogenization as a remote field treatment of IHNV samples before shipment to the laboratory. Maintenance of viral infectivity varied widely among different homogenates and fluids. For short-term storage, 4°C was generally the most efficient temperature for preserving infectious virus in ovarian fluids, Sera and homogenates of eggs, spleen, whole fry and brain, while infectivity was most efficiently preserved in kidney and liver homogenates by storage at −20°C. Infectious virus was not detected in any sample stored for one year at −20°C. Variations in retention of viral infectivity make homogenization of samples in the field followed by transfer to the laboratory unacceptable.

  11. Carbohydrate exerts a mild influence on fluid retention following exercise-induced dehydration.

    PubMed

    Osterberg, Kristin L; Pallardy, Shannon E; Johnson, Richard J; Horswill, Craig A

    2010-02-01

    Rapid and complete rehydration, or restoration of fluid spaces, is important when acute illness or excessive sweating has compromised hydration status. Many studies have investigated the effects of graded concentrations of sodium and other electrolytes in rehydration solutions; however, no study to date has determined the effect of carbohydrate on fluid retention when electrolyte concentrations are held constant. The purpose of this study was to determine the effect of graded levels of carbohydrate on fluid retention following exercise-induced dehydration. Fifteen heat-acclimatized men exercised in the heat for 90 min with no fluid to induce 2-3% dehydration. After a 30-min equilibration period, they received, over the course of 60 min, one of five test beverages equal to 100% of the acute change in body mass. The experimental beverages consisted of a flavored placebo with no electrolytes (P), placebo with electrolytes (P + E), 3%, 6%, and 12% carbohydrate solutions with electrolytes. All beverages contained the same type and concentration of electrolytes (18 meq/l Na(+), 3 meq/l K(+), 11 meq/l Cl(-)). Subjects voided their bladders at 60, 90, 120, 180, and 240 min, and urine specific gravity and urine volume were measured. Blood samples were taken before exercise and 30, 90, 180, and 240 min following exercise and were analyzed for glucose, sodium, hemoglobin, hematocrit, renin, aldosterone, and osmolality. Body mass was measured before and after exercise and a final body mass was taken at 240 min. There were no differences in percent dehydration, sweat loss, or fluid intake between trials. Fluid retention was significantly greater for all carbohydrate beverages compared with P (66.3 +/- 14.4%). P + E (71.8 +/- 9.9%) was not different from water, 3% (75.4 +/- 7.8%) or 6% (75.4 +/- 16.4%) but was significantly less than 12% (82.4 +/- 9.2%) retention of the ingested fluid. No difference was found between the carbohydrate beverages. Carbohydrate at the levels

  12. PPARγ agonist-induced fluid retention depends on αENaC expression in connecting tubules

    PubMed Central

    Fu, Yiling; Gerasimova, Maria; Batz, Falk; Kuczkowski, Alexander; Alam, Yasaman; Sanders, Paul W.; Ronzaud, Caroline; Hummler, Edith; Vallon, Volker

    2014-01-01

    Background/Aims Thiazolidinediones (TZDs, e.g. rosiglitazone (RGZ)) are peroxisome proliferator–activated receptor γ (PPARγ) agonists used to treat type 2 diabetes. Clinical limitations include TZD-induced fluid retention and body weight (BW) increase, which are inhibited by amiloride, an epithelial-sodium channel (ENaC) blocker. RGZ-induced fluid retention is maintained in mice with αENaC knockdown in the collecting duct (CD). Since ENaC in the connecting tubule (CNT) rather than in CD appears to be critical for normal NaCl retention, we aimed to further explore the role of ENaC in CNT in RGZ-induced fluid retention. Methods Mice with conditional inactivation of αENaC in both CNT and CD were used (αENaC lox/lox AQP2-Cre; “αENaC-CNT/CD-KO”) and compared with littermate controls (αENaC lox/lox mice; “WT”). BW was monitored, and total body water (TBW) and extracellular fluid volume (ECF) determined by bioelectrical impedance spectroscopy (BIS) before and after RGZ (320 mg/kg diet for 10 days). Results On regular NaCl diet, αENaC-CNT/CD-KO had normal BW, TBW, ECF, hematocrit, and plasma Na+, K+, and creatinine, associated with an increase in plasma aldosterone compared with WT. Challenging αENaC-CNT/CD-KO with a low NaCl diet unmasked impaired NaCl and K homeostasis, consistent with effective knockdown of αENaC. In WT, RGZ increased BW (+6.1%), TBW (+8.4%) and ECF (+10%), consistent with fluid retention. These changes were significantly attenuated in αENaC-CNT/CD-KO (+3.4, 1.3, and 4.3%). Conclusion Together with previous studies, the current results are consistent with a role of αENaC in CNT in RGZ-induced fluid retention, which dovetails with the physiological relevance of ENaC in this segment. PMID:25531136

  13. A closer study of methanol adsorption and its impact on solute retentions in supercritical fluid chromatography.

    PubMed

    Glenne, Emelie; Öhlén, Kristina; Leek, Hanna; Klarqvist, Magnus; Samuelsson, Jörgen; Fornstedt, Torgny

    2016-04-15

    Surface excess adsorption isotherms of methanol on a diol silica adsorbent were measured in supercritical fluid chromatography (SFC) using a mixture of methanol and carbon dioxide as mobile phase. The tracer pulse method was used with deuterium labeled methanol as solute and the tracer peaks were detected using APCI-MS over the whole composition range from neat carbon dioxide to neat methanol. The results indicate that a monolayer (4Å) of methanol is formed on the stationary phase. Moreover, the importance of using the set or the actual methanol fractions and volumetric flows in SFC was investigated by measuring the mass flow respective pressure and by calculations of the actual volume fraction of methanol. The result revealed a significant difference between the value set and the actually delivered volumetric methanol flow rate, especially at low modifier fractions. If relying only on the set methanol fraction in the calculations, the methanol layer thickness should in this system be highly overestimated. Finally, retention times for a set of solutes were measured and related to the findings summarized above concerning methanol adsorption. A strongly non-linear relationship between the logarithms of the retention factors and the modifier fraction in the mobile phase was revealed, prior to the established monolayer. At modifier fractions above that required for establishment of the methanol monolayer, this relationship turns linear which explains why the solute retention factors are less sensitive to changes in modifier content in this region.

  14. Effect of reference conditions on flow rate, modifier fraction and retention in supercritical fluid chromatography.

    PubMed

    De Pauw, Ruben; Shoykhet Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

    2016-08-12

    When using compressible mobile phases such as fluidic CO2, the density, the volumetric flow rates and volumetric fractions are pressure dependent. The pressure and temperature definition of these volumetric parameters (referred to as the reference conditions) may alter between systems, manufacturers and operating conditions. A supercritical fluid chromatography system was modified to operate in two modes with different definition of the eluent delivery parameters, referred to as fixed and variable mode. For the variable mode, the volumetric parameters are defined with reference to the pump operating pressure and actual pump head temperature. These conditions may vary when, e.g. changing the column length, permeability, flow rate, etc. and are thus variable reference conditions. For the fixed mode, the reference conditions were set at 150bar and 30°C, resulting in a mass flow rate and mass fraction of modifier definition which is independent of the operation conditions. For the variable mode, the mass flow rate of carbon dioxide increases with system pump operating pressure, decreasing the fraction of modifier. Comparing the void times and retention factor shows that the deviation between the two modes is almost independent of modifier percentage, but depends on the operating pressure. Recalculating the set volumetric fraction of modifier to the mass fraction results in the same retention behaviour for both modes. This shows that retention in SFC can be best modelled using the mass fraction of modifier. The fixed mode also simplifies method scaling as it only requires matching average column pressure.

  15. The clearance concept with special reference to determination of glomerular filtration rate in patients with fluid retention.

    PubMed

    Henriksen, Ulrik L; Henriksen, Jens H

    2015-01-01

    In subjects without fluid retention, the total plasma clearance of a renal filtration indicator (inulin, (99m) Tc-DTPA, (51) Cr-EDTA) is close to the urinary plasma clearance. Conversely, in patients with fluid retention (oedema, pleural effusions, ascites), there is a substantial discrepancy between the total plasma clearance and the urinary plasma clearance. This is owing to delayed indicator distribution to smaller or larger parts of the interstitial space, which in patients with ascites may simulate a peritoneal dialysator. In patients with fluid retention, urinary plasma clearance should be assessed to obtain a correct measurement of the glomerular filtration rate (GFR). In theory, total plasma clearance with late samples (24-h, 48-h) may be applied in patients with fluid retention, but validation hereof has not been performed. Until such studies are completed, it is recommended that patients with fluid retention have their GFR measured by a urinary plasma clearance technique with controlled quantitative urinary sampling within a few hours after indicator injection.

  16. Eligibility, recruitment, and retention of African Americans with severe mental illness in community research.

    PubMed

    Hampton, Michelle DeCoux; White, Mary C; Chafetz, Linda

    2009-04-01

    Data that addresses severely mentally ill (SMI) African Americans (AAs) likelihood to participate in clinical research is limited. This study's purpose was to determine if differences exist between races regarding eligibility, recruitment, and retention in a community-based clinical trial. The sample included 293 participants. Data sources included clinical records and interviews. Logistic regression was used for analysis. AAs were as likely to participate and to complete followup interviews as Whites. In contrast to studies about non-mentally ill AAs, AAs with SMI appeared to be as willing to consent to and to remain in clinical research studies as Whites.

  17. The acute effects of fluid intake on urine specific gravity and fluid retention in a mildly dehydrated state.

    PubMed

    Logan-Sprenger, Heather M; Spriet, Lawrence L

    2013-04-01

    Many athletes arrive at training sessions and competitions in a mildly hypohydrated (HYPO) state and are instructed to drink fluids before exercise to reach a euhydrated (HYD) state. Ten recreational athletes (6 women, 4 men; 71.9 ± 4.6 kg, 25.2 ± 0.9 years) participated in the studies to examine (a) the day-to-day variability of morning urine specific gravity (USG), (b) the effects of consuming 600 ml of water on the hydration status of HYD and HYPO (USG > 1.020) subjects, and (c) the effects of consuming water (W), salt-water (SW, 40 mM Na), a carbohydrate-electrolyte solution with 3% or light carbohydrate (CES-L, 20 mM Na) or a CES with 6% carbohydrate (CES, 20 mM Na) on the hydration status of HYPO subjects. The hydration status was assessed with USG and body mass measures and urine volume collections. The day-to-day variability in morning USG (coefficient of variation = 0.2 ± 0.1%) was low and the responses to 600 ml of W ingestion were repeatable. Pretrial USG was 1.022 ± 0.001 in the HYPO trial and decreased <1.020 by 45 minutes (1.013 ± 0.003). In the CES study, HYPO subjects reached HYD status at 45 minutes in all conditions (W 1.013 ± 0.003, SW 1.013 ± 0.003, CES-L 1.011 ± 0.003, CES 1.017 ± 0.004) because salt or CES ingestion did not affect fluid retention (W 68%, SW 72%, CES-L 68%, CES 76%). This study demonstrated that mildly HYPO subjects could reach euhydration within 45 minutes of the ingestion of 600 ml of W or a combination of salt and CES solutions. Following this practice will minimize the incidence of starting a practice or competition hypohydrated.

  18. Analytical and Numerical Studies of Several Fluid Mechanical Problems

    NASA Astrophysics Data System (ADS)

    Kong, D. L.

    2014-03-01

    In this thesis, three parts, each with several chapters, are respectively devoted to hydrostatic, viscous, and inertial fluids theories and applications. Involved topics include planetary, biological fluid systems, and high performance computing technology. In the hydrostatics part, the classical Maclaurin spheroids theory is generalized, for the first time, to a more realistic multi-layer model, establishing geometries of both the outer surface and the interfaces. For one of its astrophysical applications, the theory explicitly predicts physical shapes of surface and core-mantle-boundary for layered terrestrial planets, which enables the studies of some gravity problems, and the direct numerical simulations of dynamo flows in rotating planetary cores. As another application of the figure theory, the zonal flow in the deep atmosphere of Jupiter is investigated for a better understanding of the Jovian gravity field. An upper bound of gravity field distortions, especially in higher-order zonal gravitational coefficients, induced by deep zonal winds is estimated firstly. The oblate spheroidal shape of an undistorted Jupiter resulting from its fast solid body rotation is fully taken into account, which marks the most significant improvement from previous approximation based Jovian wind theories. High viscosity flows, for example Stokes flows, occur in a lot of processes involving low-speed motions in fluids. Microorganism swimming is such a typical case. A fully three dimensional analytic solution of incompressible Stokes equation is derived in the exterior domain of an arbitrarily translating and rotating prolate spheroid, which models a large family of microorganisms such as cocci bacteria. The solution is then applied to the magnetotactic bacteria swimming problem, and good consistency has been found between theoretical predictions and laboratory observations of the moving patterns of such bacteria under magnetic fields. In the analysis of dynamics of planetary

  19. Dual Impact of Tolvaptan on Intracellular and Extracellular Water in Chronic Kidney Disease Patients with Fluid Retention

    PubMed Central

    Masuda, Takahiro; Murakami, Takuya; Igarashi, Yusuke; Okabe, Kyochika; Kobayashi, Takahisa; Takeda, Shin-ichi; Saito, Takako; Sekiguchi, Chuji; Miyazawa, Yasuharu; Akimoto, Tetsu; Saito, Osamu; Muto, Shigeaki; Nagata, Daisuke

    2016-01-01

    Objective Tolvaptan, an oral selective V2-receptor antagonist, is a water diuretic that ameliorates fluid retention with a lower risk of a worsening renal function than conventional loop diuretics. Although loop diuretics predominantly decrease extracellular water (ECW) compared with intracellular water (ICW), the effect of tolvaptan on fluid distribution remains unclear. We therefore examined how tolvaptan changes ICW and ECW in accordance with the renal function. Methods Six advanced chronic kidney disease patients (stage 4 or 5) with fluid retention were enrolled in this study. Tolvaptan (7.5 mg/day) added to conventional diuretic treatment was administered to remove fluid retention. The fluid volume was measured using a bioimpedance analysis device before (day 0) and after (day 5 or 6) tolvaptan treatment. Results Body weight decreased by 2.6%±1.3% (64.4±6.5 vs. 62.8±6.3 kg, p=0.06), and urine volume increased by 54.8%±23.9% (1,215±169 vs. 1,709±137 mL/day, p=0.03) between before and after tolvaptan treatment. Tolvaptan significantly decreased ICW (6.5%±1.5%, p=0.01) and ECW (7.5%±1.4%, p=0.02), which had similar reduction rates (p=0.32). The estimated glomerular filtration rate remained unchanged during the treatment (14.6±2.8 vs. 14.9±2.7 mL/min/1.732 m, p=0.35). Conclusion Tolvaptan ameliorates body fluid retention, and induces an equivalent reduction rate of ICW and ECW without a worsening renal function. Tolvaptan is a novel water diuretic that has a different effect on fluid distribution compared with conventional loop diuretics. PMID:27725533

  20. Computational fluid dynamics simulation of transport and retention of nanoparticle in saturated sand filters.

    PubMed

    Hassan, Ashraf Aly; Li, Zhen; Sahle-Demessie, Endalkachew; Sorial, George A

    2013-01-15

    Experimental and computational investigation of the transport parameters of nanoparticles (NPs) flowing through porous media has been made. This work intends to develop a simulation applicable to the transport and retention of NPs in saturated porous media for investigating the effect of process conditions and operating parameters such, as ion strength, and filtration efficiency. Experimental data obtained from tracer and nano-ceria, CeO(2), breakthrough studies were used to characterize dispersion of nanoparticle with the flow and their interaction with sand packed columns with different heights. Nanoparticle transport and concentration dynamics were solved using the Eulerian computational fluid dynamics (CFD) solver ANSYS/FLUENT(®) based on a scaled down flow model. A numerical study using the Navier-Stokes equation with second order interaction terms was used to simulate the process. Parameters were estimated by fitting tracer, experimental NP transport data, and interaction of NP with the sand media. The model considers different concentrations of steady state inflow of NPs and different amounts of spike concentrations. Results suggest that steady state flow of dispersant-coated NPs would not be retained by a sand filter, while spike concentrations could be dampened effectively. Unlike analytical solutions, the CFD allows estimating flow profiles for structures with complex irregular geometry and uneven packing.

  1. Noble gases in gas shales : Implications for gas retention and circulating fluids.

    NASA Astrophysics Data System (ADS)

    Basu, Sudeshna; Jones, Adrian; Verchovsky, Alexander

    2016-04-01

    Gas shales from three cores of Haynesville-Bossier formation have been analysed simultaneously for carbon, nitrogen and noble gases (He, Ne, Ar, Xe) to constrain their source compositions and identify signatures associated with high gas retention. Ten samples from varying depths of 11785 to 12223 feet from each core, retrieved from their centres, have been combusted from 200-1200°C in incremental steps of 100°C, using 5 - 10 mg of each sample. Typically, Xe is released at 200°C and is largely adsorbed, observed in two of the three cores. The third core lacked any measureable Xe. High 40Ar/36Ar ratio up to 8000, is associated with peak release of nitrogen with distinctive isotopic signature, related to breakdown of clay minerals at 500°C. He and Ne are also mostly released at the same temperature step and predominantly hosted in the pore spaces of the organic matter associated with the clay. He may be produced from the uranium related to the organic matter. The enrichment factors of noble gases defined as (iX/36Ar)sample/(iX/36Ar)air where iX denotes any noble gas isotope, show Ne and Xe enrichment observed commonly in sedimentary rocks including shales (Podosek et al., 1980; Bernatowicz et al., 1984). This can be related to interaction of the shales with circulating fluids and diffusive separation of gases (Torgersen and Kennedy, 1999), implying the possibility of loss of gases from these shales. Interaction with circulating fluids (e.g. crustal fluids) have been further confirmed using 20Ne/N2, 36Ar/N2 and 4He/N2 ratios. Deviations of measured 4He/40Ar* (where 40Ar* represents radiogenic 40Ar after correcting for contribution from atmospheric Ar) from expected values has been used to monitor gas loss by degassing. Bernatowicz, T., Podosek, F.A., Honda, M., Kramer, F.E., 1984. The Atmospheric Inventory of Xenon and Noble Gases in Shales: The Plastic Bag Experiment. Journal of Geophysical Research 89, 4597-4611. Podosek, F.A., Honda, M., Ozima, M., 1980

  2. Thermocapillary flow with evaporation and condensation and its effect on liquid retention in low-G fluid acquisition devices

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.

    1994-01-01

    The steady motion, thermal and free surface behavior of a volatile, wetting liquid in microgravity are studied using scaling and numerical techniques. The objective is to determine whether the thermocapillary and two-phase convection arising from thermodynamic nonequilibrium along the porous surfaces of spacecraft liquid acquisition devices could cause the retention failures observed with liquid hydrogen and heated vapor pressurant. Why these devices seem immune to retention loss when pressurized with heated helium or heated directly through the porous structure was also examined. Results show that highly wetting fluids exhibit large negative and positive dynamic pressure gradients towards the meniscus interline when superheated and subcooled, respectively. With superheating, the pressure variation and recoil force arising from liquid/vapor phase change exert the same influence on surface morphology and promote retention. With subcooling, however, the pressure distribution produces a suction that degrades mechanical equilibrium of the surface. This result indicates that thermocapillary-induced deformation arising from subcooling and condensation is the likely cause for retention loss. In addition, increasing the level of nonequilibrium by reducing accommodation coefficient suppresses deformation and explains why this failure mode does not occur in instances of direct screen heating or pressurization with a heated inert gas.

  3. Fluid Retention Associated with Imatinib Treatment in Patients with Gastrointestinal Stromal Tumor: Quantitative Radiologic Assessment and Implications for Management

    PubMed Central

    Shinagare, Atul B.; Krajewski, Katherine M.; Pyo, Junhee; Tirumani, Sree Harsha; Jagannathan, Jyothi P.; Ramaiya, Nikhil H.

    2015-01-01

    Objective We aimed to describe radiologic signs and time-course of imatinib-associated fluid retention (FR) in patients with gastrointestinal stromal tumor (GIST), and its implications for management. Materials and Methods In this Institutional Review Board-approved, retrospective study of 403 patients with GIST treated with imatinib, 15 patients with imaging findings of FR were identified by screening radiology reports, followed by manual confirmation. Subcutaneous edema, ascites, pleural effusion, and pericardial effusion were graded on a four-point scale on CT scans; total score was the sum of these four scores. Results The most common radiologic sign of FR was subcutaneous edema (15/15, 100%), followed by ascites (12/15, 80%), pleural effusion (11/15, 73%), and pericardial effusion (6/15, 40%) at the time of maximum FR. Two distinct types of FR were observed: 1) acute/progressive FR, characterized by acute aggravation of FR and rapid improvement after management, 2) intermittent/steady FR, characterized by occasional or persistent mild FR. Acute/progressive FR always occurred early after drug initiation/dose escalation (median 1.9 month, range 0.3-4.0 months), while intermittent/steady FR occurred at any time. Compared to intermittent/steady FR, acute/progressive FR was severe (median score, 5 vs. 2.5, p = 0.002), and often required drug-cessation/dose-reduction. Conclusion Two distinct types (acute/progressive and intermittent/steady FR) of imatinib-associated FR are observed and each type requires different management. PMID:25741192

  4. Hot soup! Correlating the severity of liquid scald burns to fluid and biomedical properties.

    PubMed

    Loller, Cameron; Buxton, Gavin A; Kerzmann, Tony L

    2016-05-01

    Burns caused by hot drinks and soups can be both debilitating and costly, especially to pediatric and geriatric patients. This research is aimed at better understanding the fluid properties that can influence the severity of skin burns. We use a standard model which combines heat transfer and biomedical equations to predict burn severity. In particular, experimental data from a physical model serves as the input to our numerical model to determine the severity of scald burns as a consequence of actual fluid flows. This technique enables us to numerically predict the heat transfer from the hot soup into the skin, without the need to numerically estimate the complex fluid mechanics and thermodynamics of the potentially highly viscous and heterogeneous soup. While the temperature of the soup is obviously is the most important fact in determining the degree of burn, we also find that more viscous fluids result in more severe burns, as the slower flowing thicker fluids remain in contact with the skin for longer. Furthermore, other factors can also increase the severity of burn such as a higher initial fluid temperature, a greater fluid thermal conductivity, or a higher thermal capacity of the fluid. Our combined experimental and numerical investigation finds that for average skin properties a very viscous fluid at 100°C, the fluid must be in contact with the skin for around 15-20s to cause second degree burns, and more than 80s to cause a third degree burn.

  5. Effects of pressure drop, particle size and thermal conditions on retention and efficiency in supercritical fluid chromatography.

    PubMed

    Poe, Donald P; Schroden, Jonathan J

    2009-11-06

    The effects of particle size and thermal insulation on retention and efficiency in packed-column supercritical fluid chromatography with large pressure drops are described for the separation of a series of model n-alkane solutes. The columns were 2.0mm i.d.x150mm long and were packed with 3, 5, or 10-mum porous octylsilica particles. Separations were performed with pure carbon dioxide at 50 degrees C at average mobile phase densities of 0.47g/mL (107bar) and 0.70g/mL (151bar). The three principal causes of band broadening were the normal dispersion processes described by the van Deemter equation, changes in the retention factor due to the axial density gradient, and radial temperature gradients associated with expansion of the mobile phase. At the lower density the use of thermal insulation resulted in significant improvements in efficiency and decreased retention times at large pressure drops. The effects are attributed to the elimination of radial temperature gradients and the concurrent enhancement of the axial temperature gradient. Thermal insulation had no significant effect on chromatographic performance at the higher density. A simple expression to predict the onset of excess efficiency loss due to the radial temperature gradient is proposed.

  6. Computational Fluid Dynamics Simulation of Transport and Retention of Nanoparticle in Saturated Sand Filters

    EPA Science Inventory

    Experimental and computational investigation of the transport parameters of nano particles flowing through porous media has been made. The objective of this work was to develop a simulation capability applicable to the transport and retention of nanoparticles (NPs) in saturated p...

  7. Effect of electrolyte addition to rehydration drinks consumed after severe fluid and energy restriction.

    PubMed

    James, Lewis J; Shirreffs, Susan M

    2015-02-01

    This study examined the effect of electrolyte addition to drinks ingested after severe fluid and energy restriction (FER). Twelve subjects (6 male and 6 female) completed 3 trials consisting of 24-hour FER (energy intake: 21 kJ·kg body mass; water intake: 5 ml·kg body mass), followed by a 2-hour rehydration period and a 4-hour monitoring period. During rehydration, subjects ingested a volume of drink equal to 125% of the body mass lost during FER in 6 aliquots, once every 20 minutes. Drinks were a sugar-free lemon squash (P) or the P drink with the addition of 50 mmol·L sodium chloride (Na) or 30 mmol·L potassium chloride (K). Total void urine samples were given before and after FER and every hour during rehydration and monitoring. Over all trials, FER produced a 2.1% reduction in body mass and negative sodium (-67 mmol), potassium (-48 mmol), and chloride (-84 mmol) balances. Urine output after drinking was 1627 (540) ml (P), 1391 (388) ml (K), and 1150 (438) ml (Na), with a greater postdrinking urine output during P than Na (p ≤ 0.05). Ingestion of drink Na resulted in a more positive sodium balance compared with P or K (p < 0.001), whereas ingestion of drink K resulted in a more positive potassium balance compared with P or Na (p < 0.001). These results demonstrate that after 24-hour FER, ingestion of a high sodium drink results in an increased sodium balance that augments greater drink retention compared with a low electrolyte placebo drink.

  8. SMN deficiency in severe models of spinal muscular atrophy causes widespread intron retention and DNA damage.

    PubMed

    Jangi, Mohini; Fleet, Christina; Cullen, Patrick; Gupta, Shipra V; Mekhoubad, Shila; Chiao, Eric; Allaire, Norm; Bennett, C Frank; Rigo, Frank; Krainer, Adrian R; Hurt, Jessica A; Carulli, John P; Staropoli, John F

    2017-03-21

    Spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disease, is the leading monogenic cause of infant mortality. Homozygous loss of the gene survival of motor neuron 1 (SMN1) causes the selective degeneration of lower motor neurons and subsequent atrophy of proximal skeletal muscles. The SMN1 protein product, survival of motor neuron (SMN), is ubiquitously expressed and is a key factor in the assembly of the core splicing machinery. The molecular mechanisms by which disruption of the broad functions of SMN leads to neurodegeneration remain unclear. We used an antisense oligonucleotide (ASO)-based inducible mouse model of SMA to investigate the SMN-specific transcriptome changes associated with neurodegeneration. We found evidence of widespread intron retention, particularly of minor U12 introns, in the spinal cord of mice 30 d after SMA induction, which was then rescued by a therapeutic ASO. Intron retention was concomitant with a strong induction of the p53 pathway and DNA damage response, manifesting as γ-H2A.X positivity in neurons of the spinal cord and brain. Widespread intron retention and markers of the DNA damage response were also observed with SMN depletion in human SH-SY5Y neuroblastoma cells and human induced pluripotent stem cell-derived motor neurons. We also found that retained introns, high in GC content, served as substrates for the formation of transcriptional R-loops. We propose that defects in intron removal in SMA promote DNA damage in part through the formation of RNA:DNA hybrid structures, leading to motor neuron death.

  9. SMN deficiency in severe models of spinal muscular atrophy causes widespread intron retention and DNA damage

    PubMed Central

    Jangi, Mohini; Fleet, Christina; Cullen, Patrick; Gupta, Shipra V.; Mekhoubad, Shila; Chiao, Eric; Allaire, Norm; Bennett, C. Frank; Rigo, Frank; Krainer, Adrian R.; Hurt, Jessica A.; Carulli, John P.; Staropoli, John F.

    2017-01-01

    Spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disease, is the leading monogenic cause of infant mortality. Homozygous loss of the gene survival of motor neuron 1 (SMN1) causes the selective degeneration of lower motor neurons and subsequent atrophy of proximal skeletal muscles. The SMN1 protein product, survival of motor neuron (SMN), is ubiquitously expressed and is a key factor in the assembly of the core splicing machinery. The molecular mechanisms by which disruption of the broad functions of SMN leads to neurodegeneration remain unclear. We used an antisense oligonucleotide (ASO)-based inducible mouse model of SMA to investigate the SMN-specific transcriptome changes associated with neurodegeneration. We found evidence of widespread intron retention, particularly of minor U12 introns, in the spinal cord of mice 30 d after SMA induction, which was then rescued by a therapeutic ASO. Intron retention was concomitant with a strong induction of the p53 pathway and DNA damage response, manifesting as γ-H2A.X positivity in neurons of the spinal cord and brain. Widespread intron retention and markers of the DNA damage response were also observed with SMN depletion in human SH-SY5Y neuroblastoma cells and human induced pluripotent stem cell-derived motor neurons. We also found that retained introns, high in GC content, served as substrates for the formation of transcriptional R-loops. We propose that defects in intron removal in SMA promote DNA damage in part through the formation of RNA:DNA hybrid structures, leading to motor neuron death. PMID:28270613

  10. Obstructive Sleep Apnea Severity and Overnight Body Fluid Shift before and after Hemodialysis

    PubMed Central

    Forni Ogna, Valentina; Mihalache, Alexandra; Pruijm, Menno; Halabi, Georges; Phan, Olivier; Cornette, Françoise; Bassi, Isabelle; Haba Rubio, José; Burnier, Michel; Heinzer, Raphaël

    2015-01-01

    Background and objectives Obstructive sleep apnea is associated with significantly increased cardiovascular morbidity and mortality. Fluid overload may promote obstructive sleep apnea in patients with ESRD through an overnight fluid shift from the legs to the neck soft tissues. Body fluid shift and severity of obstructive sleep apnea before and after hemodialysis were compared in patients with ESRD. Design, setting, participants, & measurements Seventeen patients with hemodialysis and moderate to severe obstructive sleep apnea were included. Polysomnographies were performed the night before and after hemodialysis to assess obstructive sleep apnea, and bioimpedance was used to measure fluid overload and leg fluid volume. Results The mean overnight rostral fluid shift was 1.27±0.41 L prehemodialysis; it correlated positively with fluid overload volume (r=0.39; P=0.02) and was significantly lower posthemodialysis (0.78±0.38 L; P<0.001). There was no significant difference in the mean obstructive apnea-hypopnea index before and after hemodialysis (46.8±22.0 versus 42.1±18.6 per hour; P=0.21), but obstructive apnea-hypopnea index was significantly lower posthemodialysis (−10.1±10.8 per hour) in the group of 12 patients, with a concomitant reduction of fluid overload compared with participants without change in fluid overload (obstructive apnea-hypopnea index +8.2±16.1 per hour; P<0.01). A lower fluid overload after hemodialysis was significantly correlated (r=0.49; P=0.04) with a lower obstructive apnea-hypopnea index. Fluid overload—assessed by bioimpedance—was the best predictor of the change in obstructive apnea-hypopnea index observed after hemodialysis (standardized r=−0.68; P=0.01) in multivariate regression analysis. Conclusions Fluid overload influences overnight rostral fluid shift and obstructive sleep apnea severity in patients with ESRD undergoing intermittent hemodialysis. Although no benefit of hemodialysis on obstructive sleep apnea severity

  11. Psychological Dysfunction Is Associated With Symptom Severity but Not Disease Etiology or Degree of Gastric Retention in Patients With Gastroparesis

    PubMed Central

    Hasler, William L.; Parkman, Henry P.; Wilson, Laura A.; Pasricha, Pankaj J.; Koch, Kenneth L.; Abell, Thomas L.; Snape, William J.; Farrugia, Gianrico; Lee, Linda; Tonascia, James; Unalp-Arida, Aynur; Hamilton, Frank

    2011-01-01

    OBJECTIVES Gastroparesis patients may have associated psychological distress. This study aimed to measure depression and anxiety in gastroparesis in relation to disease severity, etiology, and gastric retention. METHODS Beck Depression Inventory (BDI) and State–Trait Anxiety Inventory (STAI) scores for state (Y1) and trait (Y2) anxiety were obtained from 299 gastroparesis patients from 6 centers of the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium. Severity was investigator graded as grades 1, 2, or 3 and patient reported by Gastroparesis Cardinal Symptom Index (GCSI) scores. Antiemetic/prokinetic medication use, anxiolytic and antidepressant medication use, supplemental feedings, and hospitalizations were recorded. BDI, Y1, and Y2 scores were compared in diabetic vs. idiopathic etiologies and mild (≤20%) vs. moderate (>20–35%) vs. severe (>35–50%) vs. very severe (>50%) gastric retention at 4h. RESULTS BDI, Y1, and Y2 scores were greater with increasing degrees of investigator-rated gastroparesis severity (P<0.05). BDI, Y1, and Y2 scores were higher for GCSI >3.1 vs. π3.1 (P<0.05). Antiemetic and prokinetic use and ≥6 hospitalizations/year were more common with BDI ≥20 vs. <20 (P<0.05). Anxiolytic use was more common with Y1 ≥46; antidepressant use and ≥6 hospitalizations/year were more common with Y2 ≥44 (P<0.05). BDI, Y1, and Y2 scores were not different in diabetic and idiopathic gastroparesis and did not relate to degree of gastric retention. On logistic regression, GCSI >3.1 was associated with BDI ≥20 and Y1 ≥46; antiemetic/prokinetic use was associated with BDI ≥20; anxiolytic use was associated with Y1 ≥46; and antidepressant use was associated with Y2 ≥44. CONCLUSIONS Higher depression and anxiety scores are associated with gastroparesis severity on investigator- and patient-reported assessments. Psychological dysfunction does not vary by etiology or degree of

  12. Vitamin B12 deficiency results in severe oxidative stress, leading to memory retention impairment in Caenorhabditis elegans.

    PubMed

    Bito, Tomohiro; Misaki, Taihei; Yabuta, Yukinori; Ishikawa, Takahiro; Kawano, Tsuyoshi; Watanabe, Fumio

    2017-04-01

    Oxidative stress is implicated in various human diseases and conditions, such as a neurodegeneration, which is the major symptom of vitamin B12 deficiency, although the underlying disease mechanisms associated with vitamin B12 deficiency are poorly understood. Vitamin B12 deficiency was found to significantly increase cellular H2O2 and NO content in Caenorhabditis elegans and significantly decrease low molecular antioxidant [reduced glutathione (GSH) and L-ascorbic acid] levels and antioxidant enzyme (superoxide dismutase and catalase) activities, indicating that vitamin B12 deficiency induces severe oxidative stress leading to oxidative damage of various cellular components in worms. An NaCl chemotaxis associative learning assay indicated that vitamin B12 deficiency did not affect learning ability but impaired memory retention ability, which decreased to approximately 58% of the control value. When worms were treated with 1mmol/L GSH, L-ascorbic acid, or vitamin E for three generations during vitamin B12 deficiency, cellular malondialdehyde content as an index of oxidative stress decreased to the control level, but the impairment of memory retention ability was not completely reversed (up to approximately 50%). These results suggest that memory retention impairment formed during vitamin B12 deficiency is partially attributable to oxidative stress.

  13. Performance of a semi-pilot tubular microbial electrolysis cell (MEC) under several hydraulic retention times and applied voltages.

    PubMed

    Gil-Carrera, L; Escapa, A; Carracedo, B; Morán, A; Gómez, X

    2013-10-01

    The influence of applied voltage and hydraulic retention time on the performance of a semi-pilot modular tubular wastewater-fed microbial electrolysis cell (MEC) with high scalability was investigated. A chemical oxygen demand (COD) removal efficiency of 80%, as well as an energy consumption of 0.3-1.1 Wh g-COD(-1) removed, were achieved. Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor, the poor performance of the cathode, and COD consuming by non electrogenic microorganisms. The presence of COD consuming microorganism that do not contribute to electrogenic metabolism severely affected the MEC performance.

  14. Dielectric Interactions and the Prediction of Retention Times of Pesticides in Supercritical Fluid Chromatography with CO2

    NASA Astrophysics Data System (ADS)

    Alvarez, Guillermo A.; Baumanna, Wolfram

    2005-02-01

    A thermodynamic model for the partition of a solute (pesticide) between two immiscible phases, such as the stationary and mobile phases of supercritical fluid chromatography with CO2, is developed from first principles. A key ingredient of the model is the result of the calculation made by Liptay of the energy of interaction of a polar molecule with a dielectric continuum, which represents the solvent. The strength of the interaction between the solute and the solvent, which may be considered a measure of the solvent power, is characterized by a function g = (ɛ - 1)/(2ɛ +1), where ɛ is the dielectric constant of the medium, which is a function of the temperature T and the pressure P. Since the interactions between the nonpolar supercritical CO2 solvent and the slightly polar pesticide molecules are considered to be extremely weak, a regular solution model is appropriate from the thermodynamic point of view. At constant temperature, the model predicts a linear dependence of the logarithm of the capacity factor (lnk) of the chromatographic experiment on the function g = g(P), as the pressure is varied, with a slope which depends on the dipole moment of the solute, dispersion interactions and the size of the solute cavity in the solvent. At constant pressure, once the term containing the g (solvent interaction) factor is subtracted from lnk, a plot of the resulting term against the inverse of temperature yields the enthalpy change of transfer of the solute from the mobile (supercritical CO2) phase to the stationary (adsorbent) phase. The increase in temperature with the consequent large volume expansion of the supercritical fluid lowers its solvent strength and hence the capacity factor of the column (or solute retention time) increases. These pressure and temperature effects, predicted by the model, agree excellently with the experimental retention times of seven pesticides. Beyond a temperature of about 393 K, where the liquid solvent densities approach those of

  15. Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant.

    PubMed

    Hummel, Jürgen; Steuer, Patrick; Südekum, Karl-Heinz; Hammer, Sven; Hammer, Catrin; Streich, W Jürgen; Clauss, Marcus

    2008-02-01

    Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.

  16. In-vessel melt retention as a severe accident management strategy for the Loviisa Nuclear Power Plant

    SciTech Connect

    Kymaelaeinen, O.; Tuomisto, H.; Theofanous, T.G.

    1997-02-01

    The concept of lower head coolability and in-vessel retention of corium has been approved as a basic element of the severe accident management strategy for IVO`s Loviisa Plant (VVER-440) in Finland. The selected approach takes advantage of the unique features of the plant such as low power density, reactor pressure vessel without penetrations at the bottom and ice-condenser containment which ensures flooded cavity in all risk significant sequences. The thermal analyses, which are supported by experimental program, demonstrate that in Loviisa the molten corium on the lower head of the reactor vessel is coolable externally with wide margins. This paper summarizes the approach and the plant modifications being implemented. During the approval process some technical concerns were raised, particularly with regard to thermal loadings caused by contact of cool cavity water and hot corium with the reactor vessel. Resolution of these concerns is also discussed.

  17. Semi-permeable membrane retention of synovial fluid lubricants hyaluronan and proteoglycan 4 for a biomimetic bioreactor.

    PubMed

    Blewis, Megan E; Lao, Brian J; Jadin, Kyle D; McCarty, William J; Bugbee, William D; Firestein, Gary S; Sah, Robert L

    2010-05-01

    Synovial fluid (SF) contains lubricant macromolecules, hyaluronan (HA), and proteoglycan 4 (PRG4). The synovium not only contributes lubricants to SF through secretion by synoviocyte lining cells, but also concentrates lubricants in SF due to its semi-permeable nature. A membrane that recapitulates these synovium functions may be useful in a bioreactor system for generating a bioengineered fluid (BF) similar to native SF. The objectives were to analyze expanded polytetrafluoroethylene membranes with pore sizes of 50 nm, 90 nm, 170 nm, and 3 microm in terms of (1) HA and PRG4 secretion rates by adherent synoviocytes, and (2) the extent of HA and PRG4 retention with or without synoviocytes adherent on the membrane. Experiment 1: Synoviocytes were cultured on tissue culture (TC) plastic or membranes +/- IL-1beta + TGF-beta1 + TNF-alpha, a cytokine combination that stimulates lubricant synthesis. HA and PRG4 secretion rates were assessed by analysis of medium. Experiment 2: Bioreactors were fabricated to provide a BF compartment enclosed by membranes +/- adherent synoviocytes, and an external compartment of nutrient fluid (NF). A solution with HA (1 mg/mL, MW ranging from 30 to 4,000 kDa) or PRG4 (50 microg/mL) was added to the BF compartment, and HA and PRG4 loss into the NF compartment after 2, 8, and 24 h was determined. Lubricant loss kinetics were analyzed to estimate membrane permeability. Experiment 1: Cytokine-regulated HA and PRG4 secretion rates on membranes were comparable to those on TC plastic. Experiment 2: Transport of HA and PRG4 across membranes was lowest with 50 nm membranes and highest with 3 microm membranes, and transport of high MW HA was decreased by adherent synoviocytes (for 50 and 90 nm membranes). The permeability to HA mixtures for 50 nm membranes was approximately 20 x 10(-8) cm/s (- cells) and approximately 5 x 10(-8) cm/s (+ cells), for 90 nm membranes was approximately 35 x 10(-8) cm/s (- cells) and approximately 19 x 10(-8) cm

  18. TRENDS (Transport and Retention of Nuclides in Dominant Sequences): A code for modeling iodine behavior in containment during severe accidents

    SciTech Connect

    Weber, C.F.; Beahm, E.C.; Kress, T.S.; Daish, S.R.; Shockley, W.E.

    1989-01-01

    The ultimate aim of a description of iodine behavior in severe LWR accidents is a time-dependent accounting of iodine species released into containment and to the environment. Factors involved in the behavior of iodine can be conveniently divided into four general categories: (1) initial release into containment, (2) interaction of iodine species in containment not directly involving water pools, (3) interaction of iodine species in, or with, water pools, and (4) interaction with special systems such as ice condensers or gas treatment systems. To fill the large gaps in knowledge and to provide a means for assaying the iodine source term, this program has proceeded along two paths: (1) Experimental studies of the chemical behavior of iodine under containment conditions. (2) Development of TRENDS (Transport and Retention of Nuclides in Dominant Sequences), a computer code for modeling the behavior of iodine in containment and its release from containment. The main body of this report consists of a description of TRENDS. These two parts to the program are complementary in that models within TRENDS use data that were produced in the experimental program; therefore, these models are supported by experimental evidence that was obtained under conditions expected in severe accidents. 7 refs., 1 fig., 2 tabs.

  19. Fluid pressures at the shoe-floor-contaminant interface during slips: effects of tread and implications on slip severity.

    PubMed

    Beschorner, Kurt E; Albert, Devon L; Chambers, April J; Redfern, Mark S

    2014-01-22

    Previous research on slip and fall accidents has suggested that pressurized fluid between the shoe and floor is responsible for initiating slips yet this effect has not been verified experimentally. This study aimed to (1) measure hydrodynamic pressures during slipping for treaded and untreaded conditions; (2) determine the effects of fluid pressure on slip severity; and (3) quantify how fluid pressures vary with instantaneous resultant slipping speed, position on the shoe surface, and throughout the progression of the slip. Eighteen subjects walked on known dry and unexpected slippery floors, while wearing treaded and untreaded shoes. Fluid pressure sensors, embedded in the floor, recorded hydrodynamic pressures during slipping. The maximum fluid pressures (mean+/-standard deviation) were significantly higher for the untreaded conditions (124+/-75 kPa) than the treaded conditions (1.1+/-0.29 kPa). Maximum fluid pressures were positively correlated with peak slipping speed (r=0.87), suggesting that higher fluid pressures, which are associated with untreaded conditions, resulted in more severe slips. Instantaneous resultant slipping speed and position of sensor relative to the shoe sole and walking direction explained 41% of the fluid pressure variability. Fluid pressures were primarily observed for untreaded conditions. This study confirms that fluid pressures are relevant to slipping events, consistent with fluid dynamics theory (i.e. the Reynolds equation), and can be modified with shoe tread design. The results suggest that the occurrence and severity of unexpected slips can be reduced by designing shoes/floors that reduce underfoot fluid pressures.

  20. Cardiac magnetic resonance imaging in a patient with amniotic fluid embolism associated with severe cardiopulmonary complications.

    PubMed

    Hosoya, Yumiko; Watanabe, Masafumi; Terashima, Masahiro; Amiya, Eisuke; Nakao, Tomoko; Hasegawa, Akiko; Hyodo, Hironobu; Ando, Jiro; Fujii, Tomoyuki; Nagai, Ryozo; Komuro, Issei

    2013-01-01

    Amniotic fluid embolism (AFE) is a rare but devastating complication of pregnancy. Acute circulatory failure and obstetric disseminated intravascular coagulopathy are often associated with AFE and lead to poor prognosis of this syndrome. Although many reports of AFE and its cardiopulmonary complications exist, their etiology remains unknown. Classically, it was believed that the fatal cardiopulmonary complication in AFE is due to acute and severe pulmonary hypertension caused by critical obstruction of the pulmonary vessels by embolized amniotic fluid. However, recent hypotheses are suggesting that anaphylactic reaction or a cytokine effect induced by amniotic fluid is the main pathophysiological mechanism. We report a case in which cardiac magnetic resonance imaging was performed at the chronic stage of AFE. Late gadolinium enhancement (LGE) was detected at the mid-wall of the left ventricle with no evidence of pulmonary hypertension. This finding suggests that the pathophysiological mechanism of severe cardiac complications in AFE may include direct left ventricular myocardial injury through an immune reaction or cytokine release, rather than pulmonary embolism.

  1. Detoxification combining fasting with fluid therapy for refractory cases of severe atopic dermatitis.

    PubMed

    Kim, Kyu Seok; Nam, Hae Jeong

    2013-01-01

    To introduce and determine the clinical benefits of a detoxification program that combines fasting with fluid therapy for refractory cases of severe atopic dermatitis (AD), we performed a retrospective chart review of inpatients with AD from March 2010 to February 2012 at the Department of Ophthalmology, Otorhinolaryngology and Dermatology of Korean Medicine in the Kyung Hee Medical Center. Patients were treated with the detoxification program, which combined fasting with fluid therapy, and herbal medicine, herbal wet wrap dressings, or acupuncture treatment when clinically necessary. The primary outcome was the SCORAD total index. The secondary outcome was the pruritus visual analogue scale (VAS) score in SCORAD as evaluated by a trained dermatology specialist. Among the 130 inpatients that have done detoxification, 7 patients met the inclusion criteria. The mean total SCORAD scores significantly decreased from 64.67 ± 11.72 to 26.26 ± 11.01 (P = 0.018) after the detoxification program. There was also a significant decrease in VAS score for pruritus from 8.00 ± 1.16 to 2.57 ± 0.98 (P = 0.016) between admission and discharge. We suggest that fasting with fluid therapy as a complementary and alternative treatment method may provide some benefits for patients with refractory cases of severe atopic dermatitis.

  2. Severe Ankyrin-R deficiency results in impaired surface retention and lysosomal degradation of RhAG in human erythroblasts

    PubMed Central

    Satchwell, Timothy J.; Bell, Amanda J.; Hawley, Bethan R.; Pellegrin, Stephanie; Mordue, Kathryn E.; van Deursen, Cees Th. B. M.; Braak, Nicole Heitink-ter; Huls, Gerwin; Leers, Mathie P.G; Overwater, Eline; Tamminga, Rienk Y. J.; van der Zwaag, Bert; Fermo, Elisa; Bianchi, Paola; van Wijk, Richard; Toye, Ashley M.

    2016-01-01

    Ankyrin-R provides a key link between band 3 and the spectrin cytoskeleton that helps to maintain the highly specialized erythrocyte biconcave shape. Ankyrin deficiency results in fragile spherocytic erythrocytes with reduced band 3 and protein 4.2 expression. We use in vitro differentiation of erythroblasts transduced with shRNAs targeting ANK1 to generate erythroblasts and reticulocytes with a novel ankyrin-R ‘near null’ human phenotype with less than 5% of normal ankyrin expression. Using this model, we demonstrate that absence of ankyrin negatively impacts the reticulocyte expression of a variety of proteins, including band 3, glycophorin A, spectrin, adducin and, more strikingly, protein 4.2, CD44, CD47 and Rh/RhAG. Loss of band 3, which fails to form tetrameric complexes in the absence of ankyrin, alongside GPA, occurs due to reduced retention within the reticulocyte membrane during erythroblast enucleation. However, loss of RhAG is temporally and mechanistically distinct, occurring predominantly as a result of instability at the plasma membrane and lysosomal degradation prior to enucleation. Loss of Rh/RhAG was identified as common to erythrocytes with naturally occurring ankyrin deficiency and demonstrated to occur prior to enucleation in cultures of erythroblasts from a hereditary spherocytosis patient with severe ankyrin deficiency but not in those exhibiting milder reductions in expression. The identification of prominently reduced surface expression of Rh/RhAG in combination with direct evaluation of ankyrin expression using flow cytometry provides an efficient and rapid approach for the categorization of hereditary spherocytosis arising from ankyrin deficiency. PMID:27247322

  3. Lubricin in synovial fluid of mild and severe temporomandibular joint internal derangements

    PubMed Central

    Perrotta, Rosario E.; Almeida, Luis-Eduardo; Loreto, Carla; Musumeci, Giuseppe

    2016-01-01

    Background To understand the molecular basis of temporomandibular joint (TMJ) pathologies, we aimed to investigate the lubricin levels in the TMJ synovial fluid (SF) of patients with mild to severe internal derangements (IDs). Material and Methods A total, 34 joints were the study group. Only patients, with a Wilkes stage of III, IV and V were included, in this sample. Control group consisted of SF from eight joints, from patients undergoing to orthognatic surgery. Concentrations of lubricin in the SF from both samples were measured using ELISA system. Results The mean lubricin concentration was 7.029 ± 0.21 µg/mL in stage III patients; 5.64 ± 0.10 µg/mL in stage IV patients, and 4.78 ± 0.11 µg/mL in stage V patients. The lubricin levels from stage IV and stage V patients differed significantly (P ≤ 0.001) from those of control subjects. Lubricin levels were inversely correlated with age and to VAS score. Conclusions The results of this cross-sectional study highlight the relationship between disease severity and the levels of lubricin in TMJ SF. Our findings suggest that novel biotherapeutic approaches, including the administration of recombinant lubricin in the joint cavity, for the treatment of TMJ diseases can be developed. Key words:Lubricin, TMJ, derangements, synovial fluid. PMID:27694778

  4. Effect of an oxygen plasma on the physical and chemical properties of several fluids for the liquid droplet radiator

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.; Coles, C. E.

    1986-01-01

    The Liquid Droplet Radiator is one of several radiator systems currently under investigation by NASA Lewis Research Center. It involves the direct exposure of the radiator working fluid to the space environment. An area of concern is the potential harmful effects of the low-Earth-orbit atomic oxygen environment on the radiator working fluid. To address this issue, seven candidate fluids were exposed to an oxygen plasma environment in a laboratory plasma asher. The fluids studied included Dow Corning 705 Diffusion Pump Fluid, polymethylphenylsiloxane and polydimethlsiloxane, both of which are experimental fluids made by Dow Corning, Fomblin Z25, made by Montedison, and three fluids from the Krytox family of fluids, Krytox 143AB, 1502, and 16256, which are made by DuPont. The fluids were characterized by noting changes in visual appearance, physical state, mass, and infrared spectra. Of the fluids tested, the Fomblin and the three Krytoxes were the least affected by the oxygen plasma. The only effect noted was a change in mass, which was most likely due to an oxygen-catalyzed deploymerization of the fluid molecule.

  5. Effect of an oxygen plasma on the physical and chemical properties of several fluids for the Liquid Droplet Radiator

    NASA Technical Reports Server (NTRS)

    Gulino, Daniel A.; Coles, Carolyn E.

    1987-01-01

    The Liquid Droplet Radiator is one of several radiator systems currently under investigation by NASA Lewis Research Center. It involves the direct exposure of the radiator working fluid to the space environment. An area of concern is the potential harmful effects of the low-Earth-orbit atomic oxygen environment on the radiator working fluid. To address this issue, seven candidate fluids were exposed to an oxygen plasma environment in a laboratory plasma asher. The fluids studied included Dow Corning 705 Diffusion Pump Fluid, polymethylphenylsiloxane and polydimethylsiloxane, both of which are experimental fluids made by Dow Corning, Fomblin Z25, made by Montedison, and three fluids from the Krytox family of fluids, Krytox 143AB, 1502, and 16256, which are made by DuPont. The fluids were characterized by noting changes in visual appearance, physical state, mass, and infrared spectra. Of the fluids tested, the Fomblin and the three Krytoxes were the least affected by the oxygen plasma. The only effect noted was a change in mass, which was most likely due to an oxygen-catalyzed depolymerization of the fluid molecule.

  6. Dipeptidyl peptidase IV inhibitor lowers PPARγ agonist-induced body weight gain by affecting food intake, fat mass, and beige/brown fat but not fluid retention

    PubMed Central

    Masuda, Takahiro; Fu, Yiling; Eguchi, Akiko; Czogalla, Jan; Rose, Michael A.; Kuczkowski, Alexander; Gerasimova, Maria; Feldstein, Ariel E.; Scadeng, Miriam

    2013-01-01

    Peroxisome proliferator-activated receptor-γ (PPARγ) agonists like pioglitazone (PGZ) are effective antidiabetic drugs, but they induce fluid retention and body weight (BW) gain. Dipeptidyl peptidase IV (DPP IV) inhibitors are antidiabetic drugs that enhance renal Na+ and fluid excretion. Therefore, we examined whether the DPP IV inhibitor alogliptin (ALG) ameliorates PGZ-induced BW gain. Male Sv129 mice were treated with vehicle (repelleted diet), PGZ (220 mg/kg diet), ALG (300 mg/kg diet), or a combination of PGZ and ALG (PGZ + ALG) for 14 days. PGZ + ALG prevented the increase in BW observed with PGZ but did not attenuate the increase in body fluid content determined by bioimpedance spectroscopy (BIS). BIS revealed that ALG alone had no effect on fat mass (FM) but enhanced the FM-lowering effect of PGZ; MRI analysis confirmed the latter and showed reductions in visceral and inguinal subcutaneous (sc) white adipose tissue (WAT). ALG but not PGZ decreased food intake and plasma free fatty acid concentrations. Conversely, PGZ but not ALG increased mRNA expression of thermogenesis mediator uncoupling protein 1 in epididymal WAT. Adding ALG to PGZ treatment increased the abundance of multilocular cell islets in sc WAT, and PGZ + ALG increased the expression of brown-fat-like “beige” cell marker TMEM26 in sc WAT and interscapular brown adipose tissue and increased rectal temperature vs. vehicle. In summary, DPP IV inhibition did not attenuate PPARγ agonist-induced fluid retention but prevented BW gain by reducing FM. This involved ALG inhibition of food intake and was associated with food intake-independent synergistic effects of PPARγ agonism and DPP-IV inhibition on beige/brown fat cells and thermogenesis. PMID:24347054

  7. Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

    PubMed Central

    2010-01-01

    Introduction Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients. Methods 30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used. Results Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42). Conclusions This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution. Trial registration NCT01120730. PMID:20584291

  8. PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity.

    PubMed

    Fukushima, Henrique; Alves, Vanessa Tubero Euzebio; Carvalho, Verônica Franco de; Ambrósio, Lucas Macedo Batitucci; Eichler, Rosangela Aparecida Dos Santos; Carvalho, Maria Helena Catelli de; Saraiva, Luciana; Holzhausen, Marinella

    2017-01-26

    Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

  9. Retention capacities of several bryophytes for Hg(II) with special reference to the elevation and morphology of moss growth.

    PubMed

    Sun, Shou-Qin; Wang, Ding-Yong; He, Ming; Li, Xian-Yuan; Zhang, Cheng

    2007-10-01

    Hg(II) Retention capacities of nine bryophyte species, collected from Jinfo Mountains (JFM) in Chongqing, China, had been investigated with special reference to the effect of morphology and elevation of moss growth. Results indicated that adsorption capacities of bryophytes for Hg(II) became stronger with the increase of multi-branches and leafy-shoots, as well as the elevation of moss growth, which was observed both in adsorption isotherm and adsorption kinetics experiments. Contrarily, the desorption kinetics showed a decrease tendency with the increase of multi-branches and leafy-shoots and the elevation of moss growth. The results demonstrated that bryophytes with higher multi-branches and leafy-shoots and higher growth elevation had a stronger adsorption capacity and a weaker desorption tendency, and therefore had a stronger retention capacity to Hg(II). The results disclosed the different relative sensitivity and retention capacity of mosses to pollution resulting from heavy metals, due to the differences in growth elevation and morphology. These should be considered when bryophytes were chosen as a tool for biomonitoring materials to environmental pollution, especially caused by Hg(II).

  10. Effects of resuscitation with crystalloid fluids on cardiac function in patients with severe sepsis

    PubMed Central

    Fang, Zhi Xun; Li, Yu Feng; Zhou, Xiao Qing; Zhang, Zhen; Zhang, Jin Song; Xia, Hai Ming; Xing, Guo Ping; Shu, Wei Ping; Shen, Ling; Yin, Guo Qing

    2008-01-01

    Background The use of hypertonic crystalloid solutions, including sodium chloride and bicarbonate, for treating severe sepsis has been much debated in previous investigations. We have investigated the effects of three crystalloid solutions on fluid resuscitation in severe sepsis patients with hypotension. Methods Ninety-four severe sepsis patients with hypotension were randomly assigned to three groups. The patients received the following injections within 15 min at initial treatment: Ns group (n = 32), 5 ml/kg normal saline; Hs group (n = 30), with 5 ml/kg 3.5% sodium chloride; and Sb group (n = 32), 5 ml/kg 5% sodium bicarbonate. Cardiac output (CO), systolic blood pressure, mean arterial pressure (MAP), body temperature, heart rate, respiratory rate and blood gases were measured. Results There were no differences among the three groups in CO, MAP, heart rate or respiratory rate during the 120 min trial or the 8 hour follow-up, and no significant differences in observed mortality rate after 28 days. However, improvement of MAP and CO started earlier in the Sb group than in the Ns and Hs groups. Sodium bicarbonate increased the base excess but did not alter blood pH, lactic acid or [HCO3]- values; and neither 3.5% hypertonic saline nor 5% sodium bicarbonate altered the Na+, K+, Ca2+ or Cl- levels. Conclusion All three crystalloid solutions may be used for initial volume loading in severe sepsis, and sodium bicarbonate confers a limited benefit on humans with severe sepsis. Trial registration ISRCTN36748319. PMID:18419825

  11. Don't Go Chasing Waterfalls: Excessive Fluid Resuscitation in Severe Sepsis and Septic Shock.

    PubMed

    Chen, Leon

    2016-01-01

    Aggressive fluid resuscitation is the mainstay therapy in modern sepsis management. Its efficacy was demonstrated in the landmark study by Emmanuel Rivers in 2001. However, more recent evidence largely shows that a positive fluid balance increases mortality in critically ill patients with sepsis. This article examines the theoretical benefits of fluid resuscitation and physiological responses to it that may negatively affect patients' outcome.

  12. Optimisation and characterisation of marihuana extracts obtained by supercritical fluid extraction and focused ultrasound extraction and retention time locking GC-MS.

    PubMed

    Omar, Jone; Olivares, Maitane; Alzaga, Mikel; Etxebarria, Nestor

    2013-04-01

    The optimisation of focused ultrasound extraction and supercritical fluid extraction of volatile oils and cannabinoids from marihuana has been accomplished by experimental design approach. On the one hand, the focused ultrasound extraction method of volatile compounds and cannabinoids was studied based on the optimisation of cyclohexane and isopropanol solvent mixtures, and the instrumental variables. The optimal working conditions were finally fixed at isopropanol/cyclohexane 1:1 mixture, cycles (3 s(-1)), amplitude (80%) and sonication time (5 min). On the other hand, the supercritical fluid extraction method was optimised in order to obtain a deterpenation of the plant and a subsequent cannabinoid extraction. For this purpose, pressure, temperature, flow and co-solvent percentage were optimised and the optimal working conditions were set at 100 bar, 35°C, 1 mL/min, no co-solvent for the terpenes and 20% of ethanol for the cannabinoids. Based on the retention time locking GC-MS analysis of the supercritical fluid extracts the classification of the samples according to the type of plant, the growing area and season was attained. Finally, three monoterpenes and three cannabinoids were quantified in the ranges of 0.006-6.2 μg/g and 0.96-324 mg/g, respectively.

  13. Separation of stereoisomers of several furan derivatives by capillary gas chromatography-mass spectrometry, supercritical fluid chromatography, and liquid chromatography using chiral stationary phases.

    PubMed

    Kasai, Hiroko F; Tsubuki, Masayoshi; Takahashi, Kazunori; Shirao, Mika; Matsumoto, Yohichiro; Honda, Toshio; Seyama, Yoshiyuki

    2002-11-15

    The direct separation of several stereoisomers (enantiomers and geometrical isomers) of furan derivatives, important intermediates for the synthesis of physiologically active natural products, was achieved using capillary gas chromatography/mass spectrometry with a per-O-methyl-beta-cyclodextrin, supercritical fluid chromatography and high-performance liquid chromatography with a tris(3,5-dimethylphenylcarbamate) of cellulose or amylose for the chiral stational phases, respectively. The temperature dependence of the peak resolution (Rs) and the retention factor (k) over the range of 110-130 degrees was studied using crotyl furfuryl ether in gas chromatography. Successive increases in the Rs value and of the difference between the k value of the E-isomer and the k value of the Z-isomer were observed when the gradient temperature was decreased. The per-O-methyl-beta-cyclodextrin column was suitable for use with volatile furan ethers whose molecular masses are between 150 and 180. In conclusion, the separation of thermally unstable furan derivatives was accomplished using supercritical fluid chromatography and high-performance liquid chromatography.

  14. Cerebrospinal Fluid Cortisol and Progesterone Profiles and Outcomes Prognostication after Severe Traumatic Brain Injury

    PubMed Central

    Santarsieri, Martina; Niyonkuru, Christian; McCullough, Emily H.; Dobos, Julie A.; Dixon, C. Edward; Berga, Sarah L.

    2014-01-01

    Abstract Despite significant advances in the management of head trauma, there remains a lack of pharmacological treatment options for traumatic brain injury (TBI). While progesterone clinical trials have shown promise, corticosteroid trials have failed. The purpose of this study was to (1) characterize endogenous cerebrospinal fluid (CSF) progesterone and cortisol levels after TBI, (2) determine relationships between CSF and serum profiles, and (3) assess the utility of these hormones as predictors of long-term outcomes. We evaluated 130 adults with severe TBI. Serum samples (n=538) and CSF samples (n=746) were collected for 6 days post-injury, analyzed for cortisol and progesterone, and compared with healthy controls (n=13). Hormone data were linked with clinical data, including Glasgow Outcome Scale (GOS) scores at 6 and 12 months. Group based trajectory (TRAJ) analysis was used to develop temporal hormone profiles delineating distinct subpopulations. Compared with controls, CSF cortisol levels were significantly and persistently elevated during the first week after TBI, and high CSF cortisol levels were associated with poor outcome. As a precursor to cortisol, progesterone mediated these effects. Serum and CSF levels for both cortisol and progesterone were strongly correlated after TBI relative to controls, possibly because of blood–brain barrier disruption. Also, differentially impaired hormone transport and metabolism mechanisms after TBI, potential de novo synthesis of steroids within the brain, and the complex interplay of cortisol and pro-inflammatory cytokines may explain these acute hormone profiles and, when taken together, may help shed light on why corticosteroid trials have previously failed and why progesterone treatment after TBI may be beneficial. PMID:24354775

  15. Activin a release into cerebrospinal fluid in a subset of patients with severe traumatic brain injury.

    PubMed

    Phillips, David J; Nguyen, Phuong; Adamides, Alexios A; Bye, Nicole; Rosenfeld, Jeffrey V; Kossmann, Thomas; Vallance, Shirley; Murray, Lynnette; Morganti-Kossmann, Maria C

    2006-09-01

    Activin A is a member of the transforming growth factor-beta superfamily and has been demonstrated to be elevated during inflammation and to have neuroprotective properties following neural insults. In this study, we examined whether traumatic brain injury (TBI) induced a response in activin A or in the concentrations of its binding protein, follistatin. Thirty-nine patients with severe TBI had daily, matched cerebrospinal fluid (CSF) and serum samples collected post-TBI and these were assayed for activin A and follistatin using specific immunoassays. Concentrations of both molecules were assessed relative to a variety of clinical parameters, such as the Glasgow Coma Score, computer tomography classification of TBI, measurement of injury markers, cell metabolism and membrane breakdown products. In about half of the patients, there was a notable increase in CSF activin A concentrations in the first few days post-TBI. There were only minor perturbations in either serum activin or in either CSF or serum follistatin concentrations. The CSF activin A response was not related to any of the common TBI indices, but was strongly correlated with two common markers of brain damage, neuronal specific enolase and S100-beta. Further, activin A levels were also associated with indices of metabolism, such as lactate and pyruvate, excitotoxicity (glutamate) and membrane lipid breakdown products such as glycerol. In one of the two patients who developed a CSF infection, activin A concentrations in CSF became markedly elevated. Thus, some TBI patients have an early release of activin A into the CSF that may result from activation of inflammatory and/or neuroprotective pathways.

  16. Joule-Thomson inversion curves and related coefficients for several simple fluids

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Peller, I. C.; Baron, A. K.

    1972-01-01

    The equations of state (PVT relations) for methane, oxygen, argon, carbon dioxide, carbon monoxide, neon, hydrogen, and helium were used to establish Joule-Thomson inversion curves for each fluid. The principle of corresponding states was applied to the inversion curves, and a generalized inversion curve for fluids with small acentric factors was developed. The quantum fluids (neon, hydrogen, and helium) were excluded from the generalization, but available data for the fluids xenon and krypton were included. The critical isenthalpic Joule-Thomson coefficient mu sub c was determined; and a simplified approximation mu sub c approximates T sub c divided by 6P sub c was found adequate, where T sub c and P sub c are the temperature and pressure at the thermodynamic critical point. The maximum inversion temperatures were obtained from the second virial coefficient (maximum (B/T)).

  17. The cerebrospinal fluid proteome in HIV infection: change associated with disease severity.

    SciTech Connect

    Angel, Thomas E.; Jacobs, Jon M.; Spudich, Serena S.; Gritsenko, Marina A.; Fuchs, Dietmar; Liegler, Teri; Zetterberg, Henrik; Camp, David G.; Price, Richard W.; Smith, Richard D.

    2012-03-20

    Central nervous system (CNS) infection is a constant feature of systemic HIV infection with a clinical spectrum that ranges from chronic asymptomatic infection to severe cognitive and motor dysfunction. Analysis of cerebrospinal fluid (CSF) has played an important part in defining the character of this evolving infection and response to treatment. To further characterize CNS HIV infection and its effects, we applied advanced high-throughput proteomic methods to CSF to identify novel proteins and their changes with disease progression and treatment. After establishing an accurate mass and time (AMT) tag database containing 23,141 AMT tags for CSF peptides, we analyzed 91 CSF samples by LC-MS from 12 HIV-uninfected and 14 HIV-infected subjects studied in the context of initiation of antiretroviral and correlated abundances of identified proteins (a) within and between subjects, (b) with all other proteins across the entire sample set, and (c) with 'external' CSF biomarkers of infection (HIV RNA), immune activation (neopterin) and neural injury (neurofilament light chain protein, NFL). We identified a mean of 2,333 +/- 328 (SD) peptides covering 307 +/-16 proteins in the 91 CSF sample set. Protein abundances differed both between and within subjects sampled at different time points and readily separated those with and without HIV infection. Proteins also showed inter-correlations across the sample set that were associated with biologically relevant dynamic processes. One-hundred and fifty proteins showed correlations with the external biomarkers. For example, using a threshold of cross correlation coefficient (Pearson's) {le}0.3 and {ge}0.3 for potentially meaningful relationships, a total of 99 proteins correlated with CSF neopterin (43 negative and 56 positive correlations) and related principally to neuronal plasticity and survival and to innate immunity. Pathway analysis defined several networks connecting the identified proteins, including one with amyloid

  18. Influence of deformation and fluids on Ar retention in white mica: Dating the Dover Fault, Newfoundland Appalachians

    NASA Astrophysics Data System (ADS)

    Kellett, Dawn A.; Warren, Clare; Larson, Kyle P.; Zwingmann, Horst; van Staal, Cees R.; Rogers, Neil

    2016-06-01

    White mica 40Ar/39Ar analyses may provide useful constraints on the timing of tectonic processes, but complex geological and thermal histories can perturb Ar systematics in a variety of ways. Ductile shear zones represent excellent case studies for exploring the link(s) between dynamic re-/neo-crystallization of white mica and coeval enhanced fluid flow, and their effect on 40Ar/39Ar dates. White mica 40Ar/39Ar dates were collected from compositionally similar granites that record different episodes of deformation with proximity to the Dover Fault, a terrane-bounding strike-slip shear zone in the Appalachian orogen, Newfoundland, Canada. 40Ar/39Ar data were collected in situ by laser ablation and by step heating single crystals. Results were compared to each other and against complementary U-Pb zircon and monazite, and K-Ar fault gouge analysis. Although step-heat 40Ar/39Ar is a widely applied method in orogenic settings, this dataset shows that relatively flat step-heat 40Ar/39Ar spectra are in contradiction with wide spreads in in-situ40Ar/39Ar dates from the same samples, and that plateau dates in some cases yielded mixed dates of equivocal geological significance. This result indicates that the step-wise release of Ar from white mica likely homogenizes and obscures spatially-controlled Ar isotope reservoirs in white mica from sheared rocks. In contrast, in situ laser ablation 40Ar/39Ar analysis preserves the spatial resolution of 40Ar reservoirs that have been variably reset by deformation and fluid interaction. This study therefore suggests that laser ablation is the best method for dating the timing of deformation recorded by white mica. Final interpretation of results should be guided by microstructural analysis, estimation of deformation temperature, chemical characterization of white mica, and complementary chronometers. Overall the dataset shows that granitic protoliths were emplaced between 430 and 422 Ma (U-Pb zircon). High strain deformation along the

  19. Study of blood flow in several benchmark micro-channels using a two-fluid approach

    PubMed Central

    Wu, Wei-Tao; Yang, Fang; Antaki, James F.; Aubry, Nadine; Massoudi, Mehrdad

    2015-01-01

    It is known that in a vessel whose characteristic dimension (e.g., its diameter) is in the range of 20 to 500 microns, blood behaves as a non-Newtonian fluid, exhibiting complex phenomena, such as shear-thinning, stress relaxation, and also multi-component behaviors, such as the Fahraeus effect, plasma-skimming, etc. For describing these non-Newtonian and multi-component characteristics of blood, using the framework of mixture theory, a two-fluid model is applied, where the plasma is treated as a Newtonian fluid and the red blood cells (RBCs) are treated as shear-thinning fluid. A computational fluid dynamic (CFD) simulation incorporating the constitutive model was implemented using OpenFOAM® in which benchmark problems including a sudden expansion and various driven slots and crevices were studied numerically. The numerical results exhibited good agreement with the experimental observations with respect to both the velocity field and the volume fraction distribution of RBCs. PMID:26240438

  20. [A propose to suspend the use of hydroxyethyl starch for fluid resuscitation in shock phase of severe burns].

    PubMed

    Luo, Gao-xing; Peng, Yi-zhi; Wu, Jun

    2013-10-01

    Based on the result of randomized controlled trials and meta-analysis recently, the infusion of hydroxyethyl starch (HES) was not shown to over match routine crystalline solution in exerting resuscitation effect against hypovolemia of patients with burn shock, severe systematic infection, or other critical conditions, on the other hand, it may induce renal toxicity and other toxic and side effects. Since the pathological mechanism underlying hypovolemia during shock phase after burn is similar to that of severe systemic infection, we propose to suspend the use of HES for fluid resuscitation during the shock phase of severe burn until further elucidation.

  1. Computerized Decision Support System Improves Fluid Resuscitation Outcomes Following Severe Burns: An Original Study

    DTIC Science & Technology

    2011-01-01

    stantial plasma volume deficit during the initial 48 hrs post burn, which engenders hypovolemic shock and generalized edema formation (4). These include a...3). Burn manage- ment requires specialized expertise and treatment options that may not normally be available at nonburn centers. In addi- tion...principal fluid shift into the surrounding interstitial space (i.e., third-spacing) that has to be treated to avoid burn shock conditions (5–6). *See

  2. Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

    NASA Technical Reports Server (NTRS)

    Brooks, R. L. (Inventor)

    1979-01-01

    A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

  3. Effects of organic modifier and temperature on the enantiomeric separation of several azole drugs using supercritical fluid chromatography and the Chiralpak AD column.

    PubMed

    Toribio, L; Bernal, J L; Martín, M T; Bernal, J; Del Nozal, M J

    2014-01-01

    The effects of organic modifier and temperature on the enantioseparation of 10 triazoles and eight imidazoles, using supercritical fluid chromatography with the Chiralpak AD column, have been investigated in this work. For this purpose four different organic modifiers (methanol, ethanol, 2-propanol and acetonitrile) were evaluated. Only in the case of two compounds could the enantiomeric separation not be achieved with any of the modifiers tested; the rest of compounds were baseline or partially resolved with at least one of the modifiers. The alcohol-type modifiers provided the best results in terms of retention time and resolution. In general, retention increased in the order methanol < ethanol < 2-propanol; moreover it was possible to establish a relationship between the retention and the number of aromatic rings and dioxolane groups in the molecule, that is, the higher the number is, the higher the retention time. From the study of the temperature effect, the enthalpy-entropy compensation was demonstrated for all the compounds, except for bifonazole using methanol and miconazole using acetonitrile. This suggested that both analytes are enantiomerically resolved through different mechanisms.

  4. Pharmacokinetics of meropenem determined by microdialysis in the peritoneal fluid of patients with severe peritonitis associated with septic shock.

    PubMed

    Karjagin, J; Lefeuvre, S; Oselin, K; Kipper, K; Marchand, S; Tikkerberi, A; Starkopf, J; Couet, W; Sawchuk, R J

    2008-03-01

    Our objective was to describe the pharmacokinetics of meropenem in the peritoneal fluid (PF) of six patients with severe peritonitis and septic shock and to relate measured concentrations to the minimum inhibitory concentration of bacteria. Microdialysis catheters were placed into the peritoneal space during surgery. Meropenem concentrations in plasma and in PF were analyzed using compartmental modeling. Meropenem areas under the concentration-time curve were lower in PF than in plasma (average ratio, 73.8+/-15%) because of degradation confirmed ex vivo. Compartment modeling with elimination from a peripheral compartment described the data adequately, and was used to simulate steady-state concentration profiles in plasma and PF during various dosing regimens. At the currently recommended dosing regimen of 1 g infused over 20 min every 8 h, PF concentrations of meropenem in patients with severe peritonitis associated with septic shock reach values sufficient for antibacterial effects against susceptible, but not always against intermediately susceptible, bacteria.

  5. Absence of hydrocephalus in spite of impaired cerebrospinal fluid absorption and severe intracranial hypertension.

    PubMed

    Hansen, K; Gjerris, F; Sørensen, P S

    1987-01-01

    Four patients are described presenting papilloedema, increased pressure and reduced CSF absorption--caused by either spinal tumours, leptomeningeal carcinomatosis or encephalitis. Remarkably they all had a normal CT without signs of hydrocephalus. A 24-hour intracranial pressure monitoring showed a mean pressure of 30-35 mm Hg, recurrent plateau waves and high occurrence of B waves. Conductance to CSF outflow studied by a constant perfusion test was severely reduced 0.010-0.026 ml min-1 mm Hg-1 (normal greater than 0.12 ml mm Hg-1 min-1). Despite these findings no ventricular enlargement was seen on serial CT scans. The reason therefore remains unknown. Disappearance of papilloedema and a variable clinical improvement followed shunt-insertion.

  6. The effect of lamination angle on polymer retention

    SciTech Connect

    Gao, H.W.

    1992-09-01

    Polymer retention may be affected by the reservoir geological structure due to lamination of the mineral surfaces. These laminae are very prevalent in Class I reservoirs. To account for the effect of lamination angle on polymer retention, several corefloods with three fired, rectangular, Berea sandstone cores were conducted. The three cores were cut at three different angles, 0, 30, and 90 degrees, with respect to the direction of laminations. A multiple slug retention method was used to determine the retention of a biopolymer in each core. Tracer tests were conducted before and after the biopolymer flow to determine how the retained biopolymer affected the fluid advance. A computed tomography (CT) scanning method was used to monitor the advance of the tracer. All corefloods and tracer tests were conducted at low flow rates similar to that in reservoirs. Coreflood tests revealed that polymer retention, which was mainly caused by mechanical entrapment, was higher in cores that had laminations parallel to the direction of flow than in cores that had crossbed laminae. In cores that had crossbed laminae, polymer retention increased with an increase in the lamination angle. Retained polymer is harmful to the stability of fluid front in cores that have laminations parallel to the direction of flow, but is helpful in cores that have crossbed laminae.

  7. Natural Killer Cell Assessment in Peripheral Circulation and Bronchoalveolar Lavage Fluid of Patients with Severe Sepsis: A Case Control Study.

    PubMed

    Souza-Fonseca-Guimaraes, Paulo; Guimaraes, Fernando; Natânia De Souza-Araujo, Caroline; Maria Boldrini Leite, Lidiane; Cristina Senegaglia, Alexandra; Nishiyama, Anita; Souza-Fonseca-Guimaraes, Fernando

    2017-03-12

    Sepsis is a complex systemic inflammatory syndrome, the most common cause of which is attributed to systemic underlying bacterial infection. The complete mechanisms of the dynamic pro- and anti-inflammatory processes underlying the pathophysiology of sepsis remain poorly understood. Natural killer (NK) cells play a crucial role in the pathophysiology of sepsis, leading to exaggerated inflammation due their rapid response and production of pro-inflammatory cytokines such as interferon gamma (IFN-γ). Several studies have already shown that NK cells undergo lymphopenia in the peripheral blood of patients with sepsis. However, our understanding of the mechanisms behind its cellular trafficking and its role in disease development is restricted to studies in animal models. In this study, we aimed to compare the human NK cell subset (CD56(bright or dim)) levels in the peripheral blood and bronchoalveolar lavage (BAL) fluid of sepsis patients. We conducted a case-control study with a sample size consisting of 10 control patients and 23 sepsis patients enrolled at the Hospital Cajuru (Curitiba/PR, Brazil) from 2013 to 2015. Although we were able to confirm previous observations of peripheral blood lymphopenia, no significant differences were detected in NK cell levels in the BAL fluid of these patients. Overall, these findings strengthened the evidence that peripheral blood lymphopenia is likely to be associated with cell death as a consequence of sepsis.

  8. Natural Killer Cell Assessment in Peripheral Circulation and Bronchoalveolar Lavage Fluid of Patients with Severe Sepsis: A Case Control Study

    PubMed Central

    Souza-Fonseca-Guimaraes, Paulo; Guimaraes, Fernando; Natânia De Souza-Araujo, Caroline; Maria Boldrini Leite, Lidiane; Cristina Senegaglia, Alexandra; Nishiyama, Anita; Souza-Fonseca-Guimaraes, Fernando

    2017-01-01

    Sepsis is a complex systemic inflammatory syndrome, the most common cause of which is attributed to systemic underlying bacterial infection. The complete mechanisms of the dynamic pro- and anti-inflammatory processes underlying the pathophysiology of sepsis remain poorly understood. Natural killer (NK) cells play a crucial role in the pathophysiology of sepsis, leading to exaggerated inflammation due their rapid response and production of pro-inflammatory cytokines such as interferon gamma (IFN-γ). Several studies have already shown that NK cells undergo lymphopenia in the peripheral blood of patients with sepsis. However, our understanding of the mechanisms behind its cellular trafficking and its role in disease development is restricted to studies in animal models. In this study, we aimed to compare the human NK cell subset (CD56bright or dim) levels in the peripheral blood and bronchoalveolar lavage (BAL) fluid of sepsis patients. We conducted a case-control study with a sample size consisting of 10 control patients and 23 sepsis patients enrolled at the Hospital Cajuru (Curitiba/PR, Brazil) from 2013 to 2015. Although we were able to confirm previous observations of peripheral blood lymphopenia, no significant differences were detected in NK cell levels in the BAL fluid of these patients. Overall, these findings strengthened the evidence that peripheral blood lymphopenia is likely to be associated with cell death as a consequence of sepsis. PMID:28287491

  9. Comparison of bacteria and fungus-binding mesh, foam and gauze as fillers in negative pressure wound therapy--pressure transduction, wound edge contraction, microvascular blood flow and fluid retention.

    PubMed

    Malmsjö, Malin; Ingemansson, Richard; Lindstedt, Sandra; Gustafsson, Lotta

    2013-10-01

    Bacteria- and fungus-binding mesh binds with and inactivates bacteria and fungus, which makes it an interesting alternative, wound filler for negative pressure wound therapy (NPWT). This study was conducted to compare the performance of pathogen-binding mesh, foam and gauze as wound fillers in NPWT with regard to pressure transduction, fluid retention, wound contraction and microvascular blood flow. Wounds on the backs of 16 pigs were filled with pathogen-binding mesh, foam or gauze and treated with NPWT. The immediate effects of 0, -40, -60, -80 and -120 mmHg, on pressure transduction and blood flow were examined in eight pigs using laser Doppler velocimetry. Wound contraction and fluid retention were studied during 72 hours of NPWT at -80 and -120 mmHg in the other eight pigs. Pathogen-binding mesh, gauze and foam provide similar pressure transduction to the wound bed during NPWT. Blood flow was found to decrease 0.5 cm laterally from the wound edge and increase 2.5 cm from the wound edge, but was unaltered 5.0 cm from the wound edge. The increase in blood flow was similar with all wound fillers. The decrease in blood flow was more pronounced with foam than with gauze and pathogen-binding mesh. Similarly, wound contraction was more pronounced with foam, than with gauze and pathogen-binding mesh. Wound fluid retention was the same in foam and pathogen-binding mesh, while more fluid was retained in the wound when using gauze. The blood flow 0.5-5 cm from the wound edge and the contraction of the wound during NPWT were similar when using pathogen-binding mesh and gauze. Wound fluid was efficiently removed when using pathogen-binding mesh, which may explain previous findings that granulation tissue formation is more rapid under pathogen-binding mesh than under gauze. This, in combination with its pathogen-binding properties, makes this mesh an interesting wound filler for use in NPWT.

  10. Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Correlation with Clinical Severity and Old Brain Lesions

    PubMed Central

    Seo, Kwon-Duk; Suh, Sang Hyun; Kim, Yong Bae; Kim, Ji Hwa; Ahn, Sung Jun; Kim, Dong-Seok

    2015-01-01

    Purpose Leptomeningeal collateral, in moyamoya disease (MMD), appears as an ivy sign on fluid-attenuated inversion-recovery (FLAIR) images. There has been little investigation into the relationship between presentation of ivy signs and old brain lesions. We aimed to evaluate clinical significance of ivy signs and whether they correlate with old brain lesions and the severity of clinical symptoms in patients with MMD. Materials and Methods FLAIR images of 83 patients were reviewed. Each cerebral hemisphere was divided into 4 regions and each region was scored based on the prominence of the ivy sign. Total ivy score (TIS) was defined as the sum of the scores from the eight regions and dominant hemispheric ivy sign (DHI) was determined by comparing the ivy scores from each hemisphere. According to the degree of ischemic symptoms, patients were classified into four subgroups: 1) nonspecific symptoms without motor weakness, 2) single transient ischemic attack (TIA), 3) recurrent TIA, or 4) complete stroke. Results TIS was significantly different as follows: 4.86±2.55 in patients with nonspecific symptoms, 5.89±3.10 in patients with single TIA, 9.60±3.98 in patients with recurrent TIA and 8.37±3.39 in patients with complete stroke (p=0.003). TIS associated with old lesions was significantly higher than those not associated with old lesions (9.35±4.22 vs. 7.49±3.37, p=0.032). We found a significant correlation between DHI and motor symptoms (p=0.001). Conclusion Because TIS has a strong tendency with severity of ischemic motor symptom and the presence of old lesions, the ivy sign may be useful in predicting severity of disease progression. PMID:26256975

  11. Promoting Retention

    PubMed Central

    Hall, LaToya N.; Ficker, Lisa J.; Chadiha, Letha A.; Green, Carmen R.; Jackson, James S.; Lichtenberg, Peter A.

    2016-01-01

    Objectives: The objectives of this study were to evaluate the capability of a research volunteer registry to retain community-dwelling African American older adults, and to explore demographic and health factors associated with retention. Method: A logistic regression model was used to determine the influence of demographics, health factors, and registry logic model activities on retention in a sample of 1,730 older African American adults. Results: Almost 80% of participants active in the volunteer research registry between January 2012 and June 2015 were retained. Employment, being referred to research studies, a higher number of medical conditions, and more follow-up contacts were associated with an increased likelihood of retention. Older age, more months in the registry, and more mobility problems decreased the likelihood of retention. Discussion: These results suggest the Michigan Center for Urban African American Aging Research logic model promotes retention through involving older African American adults in research through study referrals and intensive follow-up. The loss of participants due to age- and mobility-related issues indicate the registry may be losing its most vulnerable participants. PMID:28138501

  12. Expression of hypoxia-inducible factor-1α in synovial fluid and articular cartilage is associated with disease severity in knee osteoarthritis

    PubMed Central

    Qing, Liming; Lei, Pengfei; Liu, Hao; Xie, Jie; Wang, Long; Wen, Ting; Hu, Yihe

    2017-01-01

    The aim of the present study was to examine hypoxia-inducible factor 1α (HIF-1α) levels in the synovial fluid and articular cartilage of patients with primary knee osteoarthritis (OA) and to investigate their association with the severity of disease. A total of 36 patients with knee OA and ten healthy controls were enrolled. Anteroposterior knee radiographs and/or Mankin scores were assessed to determine the disease severity of the affected knee. Radiographic grading of OA in the knee was performed according to Kellgren-Lawrence criteria. HIF-1α levels in synovial fluid were measured using enzyme-linked immunosorbent assay, whereas HIF-1α levels in articular cartilage were assessed with immunohistochemical methods. Compared with healthy controls, OA patients exhibited an increased HIF-1α concentration in synovial fluid (218.17±25.12 vs. 156.66±7.74 pg/ml; P<0.001) and articular cartilage (P<0.05). Furthermore, synovial fluid HIF-1α levels demonstrated a positive correlation with articular cartilage HIF-1α levels (Pearson's P=0.815; P<0.001). Subsequent analysis showed that synovial fluid HIF-1α levels were significantly correlated with the severity of disease (Spearman's ρ=0.933; P<0.001). Furthermore, articular cartilage levels of HIF-1α also correlated with disease severity (Spearman's ρ=−0.967; P<0.001). The findings of the present study suggested that HIF-1α in synovial fluid and articular cartilage is associated with progressive joint damage and is likely to be a useful biomarker for determining disease severity and progression in knee OA. PMID:28123469

  13. Urinary Retention

    MedlinePlus

    ... indicates the bladder does not empty completely. A health care provider performs this test during an office visit. The patient often receives ... more urodynamic tests to diagnose urinary retention. The health care provider will perform these tests during an office visit. For tests that use ...

  14. Retention Checklist.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    Designed to improve student retention at Bronx Community College (BCC), this workbook is comprised of sets checklists for use by students in evaluating their progress toward a number of academic, personal, and work-related goals. The workbook is divided into five sections, each containing a set of goals and associated checklists. Part I deals with…

  15. Audit of preoperative fluid resuscitation in perforation peritonitis patients using Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity

    PubMed Central

    Kumar, Sunil

    2017-01-01

    Context: Debate continues regarding fluid (crystalloid vs. colloid) of choice for resuscitation. Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) may be used to compare the benefits of preoperative fluid resuscitation with crystalloids and colloids in peritonitis patients. Aims: The aim of this study is to compare crystalloid and colloid for preoperative resuscitation using morbidity, mortality, length of hospital stay (LOS), and time taken to resuscitate as the outcome parameters. Settings and Design: This was a prospective randomized clinical trial. Subjects and Methods: One hundred and seven peritonitis patients were prospectively randomized to fluid resuscitation by crystalloid (Group A) and colloid (Group B) solutions. Physiological score component of POSSUM was recorded before and after fluid resuscitation; operative score component was recorded at discharge/death. These scores were then used to calculate the predicted morbidity and mortality before and after the fluid resuscitation. Statistical Analysis Used: Effect on morbidity and mortality were compared by repeated measure analysis of variance, and its significance was tested by Tukey's test. LOS and time taken to resuscitate were compared using unpaired t-test. Significance was taken at 5%. Results: Fluid resuscitation improved mean predicted morbidity by 0.095 and 0.137 in Group A and Group B, respectively. Similarly, fluid resuscitation improved predicted mortality by 0.145 and 0.185 in Group A and Group B, respectively. These changes were statistically significant. Improvement in morbidity and mortality appeared greater in Group B. No difference was found in the two groups for LOS and time to resuscitate. Conclusions: Preoperative fluid resuscitation using either crystalloid or colloidal solutions decreases morbidity as well as mortality in peritonitis patients. PMID:28243006

  16. Resistant starch content among several sorghum (Sorghum bicolor) genotypes and the effect of heat treatment on resistant starch retention in two genotypes.

    PubMed

    Teixeira, Natália de Carvalho; Queiroz, Valéria Aparecida Vieira; Rocha, Maria Clara; Amorim, Aline Cristina Pinheiro; Soares, Thayana Oliveira; Monteiro, Marlene Azevedo Magalhães; de Menezes, Cícero Beserra; Schaffert, Robert Eugene; Garcia, Maria Aparecida Vieira Teixeira; Junqueira, Roberto Gonçalves

    2016-04-15

    The resistant starch (RS) contents in 49 sorghum genotypes and the effects of heat treatment using dry and wet heat on the grain and flour from two sorghum genotypes were investigated. The results showed a wide variation in the RS contents of the genotypes analyzed. The RS mean values were grouped into six distinct groups and ranged from 0.31±0.33 g/100 g to 65.66±5.46 g/100 g sorghum flour on dry basis. Dry heat causes minor losses in the RS content with retentions of up to 97.19±1.92% of this compound, whereas wet heat retained at most 6.98±0.43% of the RS. The SC 59 and (SSN76)FC6608 RED KAFIR BAZINE (ASA N23) cultivars, which have an average RS content of 65.51 g/100 g, were appropriate for human consumption, and the use of dry heat is presented as a better alternative for the preservation of RS in heat-treated grains.

  17. Correlation between plasma, synovial fluid and articular cartilage Interleukin-18 with radiographic severity in 33 patients with osteoarthritis of the knee.

    PubMed

    Wang, Youhua; Xu, Dawei; Long, Long; Deng, Xiaolong; Tao, Ran; Huang, Guicheng

    2014-08-01

    Osteoarthritis (OA) is a complex disease characterized by cartilage degeneration, secondary synovial membrane inflammation and subchondral bone changes. In recent years, many studies have confirmed that interleukin-18 (IL-18) is involved in the inflammatory process of inflammatory joint diseases. In the present study, we investigated IL-18 levels in plasma, synovial fluid and articular cartilage of patients with primary knee OA (n = 33) to analyze their relationship with radiographic severity. Compared to healthy controls (n = 15), OA patients had higher plasma and synovial fluid IL-18 concentrations(45.8 ± 22.1 vs. 23.7 ± 13.6 pg/ml, P<0.001 and 75.2 ± 40.1 vs. 28.3 ± 11.6 pg/ml, P<0.001) as measured by enzyme-linked immunosorbent assay. Also,the percentage of immunofluorescent IL-18 positive cells in articular cartilage was significantly increased in OA compared to controls (46.5 ± 10.3 vs. 2.9 ± 1.7, P<0.001). Moreover, plasma, synovial fluid and articular cartilage IL-18 significantly positively correlated with radiographic severity, respectively (r = 0.663, P<0.001, r = 0.56, P = 0.001 and r = 0.884, P<0.001). Subsequent analysis revealed that plasma, synovial fluid and articular cartilage IL-18 levels positively correlated with each other (r = 0.632, P<0.001, r = 0.489, P = 0.004 and r = 0.620, P<0.001). These data suggested that plasma, synovial fluid and articular cartilage IL-18 levels were significantly increased in OA patients, and these elevated levels were positively correlated with radiographic severity. Accordingly, our study supports the role of IL-18 in the pathophysiology of OA.

  18. The effect of lamination angle on polymer retention. FY92 annual research plan

    SciTech Connect

    Gao, H.W.

    1992-09-01

    Polymer retention may be affected by the reservoir geological structure due to lamination of the mineral surfaces. These laminae are very prevalent in Class I reservoirs. To account for the effect of lamination angle on polymer retention, several corefloods with three fired, rectangular, Berea sandstone cores were conducted. The three cores were cut at three different angles, 0, 30, and 90 degrees, with respect to the direction of laminations. A multiple slug retention method was used to determine the retention of a biopolymer in each core. Tracer tests were conducted before and after the biopolymer flow to determine how the retained biopolymer affected the fluid advance. A computed tomography (CT) scanning method was used to monitor the advance of the tracer. All corefloods and tracer tests were conducted at low flow rates similar to that in reservoirs. Coreflood tests revealed that polymer retention, which was mainly caused by mechanical entrapment, was higher in cores that had laminations parallel to the direction of flow than in cores that had crossbed laminae. In cores that had crossbed laminae, polymer retention increased with an increase in the lamination angle. Retained polymer is harmful to the stability of fluid front in cores that have laminations parallel to the direction of flow, but is helpful in cores that have crossbed laminae.

  19. Changes in B-type Natriuretic Peptide and Related Hemodynamic Parameters Following a Fluid Challenge in Critically Ill Patients with Severe Sepsis or Septic Shock

    PubMed Central

    Omar, Shahed; Ali, Ahmad; Atiya, Yahya; Mathivha, Rudo Lufuno; Dulhunty, Joel M.

    2017-01-01

    Context: Severe sepsis or septic shock. Aims: The aim of this study is to examine the effect of a fluid challenge on the B-type natriuretic peptide (BNP) and the hemodynamic state. Settings and Design: This observational study was conducted in an intensivist-led academic, mixed medical-surgical Intensive Care Unit. Subjects and Methods: Focused transthoracic echocardiogram, plasma BNP, and hemodynamic measurements were recorded at baseline and following a 500 ml fluid challenge in thirty patients. Independent predictors of the percentage (%) change in stroke volume (SV) were sought. Next, these independent predictors were assessed for a relationship with the percentage change in BNP. Statistical Analysis Used: Multiple linear regressions, Wilcoxon rank-sum test, t-test, and Pearson's correlation were used. Data analysis was carried out using SAS. The 5% significance level was used. Results: Using a multiple regression models, the percentage increase in SV was independently predicted by the percentage increase in mean arterial pressure, left ventricular end-diastolic volume/dimension (LVEDV/LVEDd), ejection fraction, and a decrease in Acute Physiology and Chronic Health Evaluation II score (P < 0.0001). Preload, measured using LVEDV1 (before the fluid challenge) was significantly larger in the fluid nonresponders (%SV increase <15%) vs. the responders (%SV increase ≥15%). Finally, the percentage change in BNP was positively correlated with left ventricular size at end diastole LVEDd, r = 0.4, P < 0.035). Conclusions: An increase in BNP soon after a fluid challenge may have some predictive utility of a large LVEDd, which in turn can be used to independently predict the SV response to a fluid challenge.

  20. The role of transpapillary drainage in management of patients with pancreatic fluid collections and pancreatic duct disruption as a consequences of severe acute pancreatitis.

    PubMed

    Jagielski, Mateusz; Smoczyński, Marian; Adrych, Krystian

    In last thirty years we have been observing significant development of an endoscopic treatment of pancreatic fluid collections, including transmural drainage of walled-off pancreatic necrosis. Simultaneously, the use of endotherapy in treatment of main pancreatic ducts disruptions has increased. Despite many publications available in current literature, concerning the endoscopic treatment of consequences of acute necrotizing pancreatitis, the role of transpapillary drainage in management of patients with pancreatic fluid collections and pancreatic duct disruption as an after-effect of severe acute pancreatitis remains unclear and is still a current problem. This publication includes comment on the article entitled 'Early dual drainage combining transpapillary endotherapy and percutaneous catheter drainage in patients with pancreatic fistula associated with severe acute pancreatitis' published by Yokoi et al. in the July-August 2016 issue of Pancreatology together with questions to the authors. Furthermore, in the article we did pay particular attention to the role of transpapillary drainage in management of pancreatic fluid collections, especially of walled-of pancreatic necrosis.

  1. Managing retention.

    PubMed

    Carter, Tony

    2007-01-01

    To build this process it is necessary to consult customers for preferences, build familiarity and knowledge to build a relationship and conduct business in a customized fashion. The process takes every opportunity to build customer satisfaction with each customer contact. It is an important process to have, since customers today are more demanding, sophisticated, educated and comfortable speaking to the company as an equal (Belk, 2003). Customers have more customized expectations so they want to be reached as individuals (Raymond and Tanner, 1994). Also, a disproportionate search for new business is costly. The cost to cultivate new customers is more than maintaining existing customers (Cathcart, 1990). Other reasons that customer retention is necessary is because many unhappy customers will never buy again from a company that dissatisfied them and they will communicate their displeasure to other people. These dissatisfied customers may not even convey their displeasure but without saying anything just stop doing business with that company, which may keep them unaware for some time that there is any problem (Cathcart, 1990).

  2. Fluid-solid equilibrium of carbon dioxide as obtained from computer simulations of several popular potential models: the role of the quadrupole.

    PubMed

    Pérez-Sánchez, G; González-Salgado, D; Piñeiro, M M; Vega, C

    2013-02-28

    In this work the solid-fluid equilibrium for carbon dioxide (CO2) has been evaluated using Monte Carlo simulations. In particular the melting curve of the solid phase denoted as I, or dry ice, was computed for pressures up to 1000 MPa. Four different models, widely used in computer simulations of CO2 were considered in the calculations. All of them are rigid non-polarizable models consisting of three Lennard-Jones interaction sites located on the positions of the atoms of the molecule, plus three partial charges. It will be shown that although these models predict similar vapor-liquid equilibria their predictions for the fluid-solid equilibria are quite different. Thus the prediction of the entire phase diagram is a severe test for any potential model. It has been found that the Transferable Potentials for Phase Equilibria (TraPPE) model yields the best description of the triple point properties and melting curve of carbon dioxide. It is shown that the ability of a certain model to predict the melting curve of carbon dioxide is related to the value of the quadrupole moment of the model. Models with low quadrupole moment tend to yield melting temperatures too low, whereas the model with the highest quadrupole moment yields the best predictions. That reinforces the idea that not only is the quadrupole needed to provide a reasonable description of the properties in the fluid phase, but also it is absolutely necessary to describe the properties of the solid phase.

  3. Corrosion behavior of several metals in ethylene glycol-base heat-transfer fluids under conditions encountered in solar energy systems

    SciTech Connect

    Zeman, G.J.

    1980-01-01

    The corrosion behavior of aluminum, copper, and iron in inhibited ethylene glycol-ASTM corrosive water solutions was evaluated in a laboratory loop under isothermal and heat-flux conditions for 1000 h at temperatures between 378 and 413/sup 0/K, in static autoclave tests at 450/sup 0/K for 500 h, and by potentiodynamic polarization measurements at temperatures between 298 and 348/sup 0/K. The effect of time, temperature, and ethylene glycol concentration of the heat-transfer fluid on the extent of inhibitor depletion was determined from analyses of the reserve alkalinity, pH, and inhibitor content of the solutions. The performance of an electrochemical sensor as a monitor of fluid quality was also evaluated. A heat flux of 0.4 to 1.0 kW/m/sup 2/ did not have a significant effect on the corrosion behavior of the various materials at temperatures between 378 and 413/sup 0/K. The corrosion rates of aluminum, copper, and iron in the 50 volume percent inhibited ethylene glycol-corrosive water solution decreased as a function of time during the 1000-h test. At 413/sup 0/K, the corrosion rate of copper was considerably higher than that of iron or aluminum at low flow velocity. Significant degradation of the fluid quality, as indicated by the measurement of the pH, reserve alkalinity, and inhibitor concentrations, occurred after several hundred hours at temperatures of approx. 450/sup 0/K.

  4. Cerebrospinal Fluid Cortisol Mediates Brain-Derived Neurotrophic Factor Relationships to Mortality after Severe TBI: A Prospective Cohort Study.

    PubMed

    Munoz, Miranda J; Kumar, Raj G; Oh, Byung-Mo; Conley, Yvette P; Wang, Zhensheng; Failla, Michelle D; Wagner, Amy K

    2017-01-01

    Distinct regulatory signaling mechanisms exist between cortisol and brain derived neurotrophic factor (BDNF) that may influence secondary injury cascades associated with traumatic brain injury (TBI) and predict outcome. We investigated concurrent CSF BDNF and cortisol relationships in 117 patients sampled days 0-6 after severe TBI while accounting for BDNF genetics and age. We also determined associations between CSF BDNF and cortisol with 6-month mortality. BDNF variants, rs6265 and rs7124442, were used to create a gene risk score (GRS) in reference to previously published hypothesized risk for mortality in "younger patients" (<48 years) and hypothesized BDNF production/secretion capacity with these variants. Group based trajectory analysis (TRAJ) was used to create two cortisol groups (high and low trajectories). A Bayesian estimation approach informed the mediation models. Results show CSF BDNF predicted patient cortisol TRAJ group (P = 0.001). Also, GRS moderated BDNF associations with cortisol TRAJ group. Additionally, cortisol TRAJ predicted 6-month mortality (P = 0.001). In a mediation analysis, BDNF predicted mortality, with cortisol acting as the mediator (P = 0.011), yielding a mediation percentage of 29.92%. Mediation effects increased to 45.45% among younger patients. A BDNF(*)GRS interaction predicted mortality in younger patients (P = 0.004). Thus, we conclude 6-month mortality after severe TBI can be predicted through a mediation model with CSF cortisol and BDNF, suggesting a regulatory role for cortisol with BDNF's contribution to TBI pathophysiology and mortality, particularly among younger individuals with severe TBI. Based on the literature, cortisol modulated BDNF effects on mortality after TBI may be related to known hormone and neurotrophin relationships to neurological injury severity and autonomic nervous system imbalance.

  5. Cerebrospinal Fluid Cortisol Mediates Brain-Derived Neurotrophic Factor Relationships to Mortality after Severe TBI: A Prospective Cohort Study

    PubMed Central

    Munoz, Miranda J.; Kumar, Raj G.; Oh, Byung-Mo; Conley, Yvette P.; Wang, Zhensheng; Failla, Michelle D.; Wagner, Amy K.

    2017-01-01

    Distinct regulatory signaling mechanisms exist between cortisol and brain derived neurotrophic factor (BDNF) that may influence secondary injury cascades associated with traumatic brain injury (TBI) and predict outcome. We investigated concurrent CSF BDNF and cortisol relationships in 117 patients sampled days 0–6 after severe TBI while accounting for BDNF genetics and age. We also determined associations between CSF BDNF and cortisol with 6-month mortality. BDNF variants, rs6265 and rs7124442, were used to create a gene risk score (GRS) in reference to previously published hypothesized risk for mortality in “younger patients” (<48 years) and hypothesized BDNF production/secretion capacity with these variants. Group based trajectory analysis (TRAJ) was used to create two cortisol groups (high and low trajectories). A Bayesian estimation approach informed the mediation models. Results show CSF BDNF predicted patient cortisol TRAJ group (P = 0.001). Also, GRS moderated BDNF associations with cortisol TRAJ group. Additionally, cortisol TRAJ predicted 6-month mortality (P = 0.001). In a mediation analysis, BDNF predicted mortality, with cortisol acting as the mediator (P = 0.011), yielding a mediation percentage of 29.92%. Mediation effects increased to 45.45% among younger patients. A BDNF*GRS interaction predicted mortality in younger patients (P = 0.004). Thus, we conclude 6-month mortality after severe TBI can be predicted through a mediation model with CSF cortisol and BDNF, suggesting a regulatory role for cortisol with BDNF's contribution to TBI pathophysiology and mortality, particularly among younger individuals with severe TBI. Based on the literature, cortisol modulated BDNF effects on mortality after TBI may be related to known hormone and neurotrophin relationships to neurological injury severity and autonomic nervous system imbalance. PMID:28337122

  6. Strategies for Teacher Retention.

    ERIC Educational Resources Information Center

    Gonzalez, Patricia

    1995-01-01

    Strategies for teacher retention are presented, including successful approaches and elements for operating a state system for personnel recruitment and retention in special education. Such initiatives as the Utah Mentor Teacher Academy; the Texas Teacher Recruitment, Retention and Assistance Program; and the Kansas Recruitment/Retention Project…

  7. Parallel Metabolomic Profiling of Cerebrospinal Fluid and Serum for Identifying Biomarkers of Injury Severity after Acute Human Spinal Cord Injury

    PubMed Central

    Wu, Yiman; Streijger, Femke; Wang, Yining; Lin, Guohui; Christie, Sean; Mac-Thiong, Jean-Marc; Parent, Stefan; Bailey, Christopher S.; Paquette, Scott; Boyd, Michael C.; Ailon, Tamir; Street, John; Fisher, Charles G.; Dvorak, Marcel F.; Kwon, Brian K.; Li, Liang

    2016-01-01

    Suffering an acute spinal cord injury (SCI) can result in catastrophic physical and emotional loss. Efforts to translate novel therapies in acute clinical trials are impeded by the SCI community’s singular dependence upon functional outcome measures. Therefore, a compelling rationale exists to establish neurochemical biomarkers for the objective classification of injury severity. In this study, CSF and serum samples were obtained at 3 time points (~24, 48, and 72 hours post-injury) from 30 acute SCI patients (10 AIS A, 12 AIS B, and 8 AIS C). A differential chemical isotope labeling liquid chromatography mass spectrometry (CIL LC-MS) with a universal metabolome standard (UMS) was applied to the metabolomic profiling of these samples. This method provided enhanced detection of the amine- and phenol-containing submetabolome. Metabolic pathway analysis revealed dysregulations in arginine-proline metabolism following SCI. Six CSF metabolites were identified as potential biomarkers of baseline injury severity, and good classification performance (AUC > 0.869) was achieved by using combinations of these metabolites in pair-wise comparisons of AIS A, B and C patients. Using the UMS strategy, the current data set can be expanded to a larger cohort for biomarker validation, as well as discovering biomarkers for predicting neurologic outcome. PMID:27966539

  8. Association of ubiquitin carboxy-terminal hydrolase-L1 in cerebrospinal fluid with clinical severity in a cohort of patients with Guillain-Barré syndrome.

    PubMed

    Nagamine, Satoshi; Fujiwara, Yuuki; Shimizu, Toshio; Kawata, Akihiro; Wada, Keiji; Isozaki, Eiji; Kabuta, Tomohiro

    2015-06-01

    Guillain-Barré syndrome (GBS) is an acute immune-mediated polyneuropathy. Although its pathogenic mechanism has been revealed and various therapeutic trials have been performed, a proportion of patients experience the severe sequelae associated with GBS. In this paper, we investigated whether the amount of the neuron-specific protein, ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1), in the cerebrospinal fluid of patients with GBS was correlated with the clinical course of the disease. UCH-L1 protein levels were greater in patients with GBS than in controls. The patients with GBS whose UCH-L1 protein levels were higher than those of the controls presented with more severe symptoms at peak. UCH-L1 protein levels tended to become elevated as the total protein levels were increased; however, elevated UCH-L1 without an increase in total protein might be correlated with severe disease course (bedridden or ventilator supported). These results suggest that UCH-L1 could be a biomarker associated with the severity of the disease at the acute phase of GBS.

  9. Fluid management of shock in severe malnutrition: what is the evidence for current guidelines and what lessons have been learned from clinical studies and trials in other pediatric populations?

    PubMed

    Obonyo, Nchafatso; Maitland, Kathryn

    2014-06-01

    Management of shock in children with severe malnutrition remains controversial. To date, the evidence supporting either benefit or harm of fluid resuscitation or rehydration is weak. This issue, however, is not unique to children with severe malnutrition; pediatric guidelines worldwide have a weak level of evidence and remain unsupported by appropriate clinical studies. In this review we give an overview of the current recommendations in other pediatric populations and appraise the strength of evidence supporting these. We summarize results from the only controlled trial ever undertaken, FEAST (Fluid Expansion As Supportive Therapy), which was conducted in resource-poor hospitals involving 3,141 African children with severe febrile illnesses and shock, including large subgroups with sepsis and malaria but excluding children with severe malnutrition. This high-quality trial provided robust evidence that fluid resuscitation increased the risk of death, leading to an excess mortality of 3 in every 100 children receiving fluid boluses, compared with controls receiving no boluses. These findings may have particular relevance to management of septic shock in children with severe malnutrition. However, they cannot be extrapolated to children with gastroenteritis, since this condition was not included in the trial. Current observational studies under way in East Africa may provide insights into myocardial and hemodynamic function in severe malnutrition, including responses to fluid challenge in those complicated by gastroenteritis. Such studies are an essential step for setting the research agenda regarding fluid management of shock in severe malnutrition.

  10. Blood oxygenation during hyperpressure intraperitoneal fluid administration in a rabbit model of severe liver injury: Evaluation of a novel concept for control of pre-hospital liver bleeding.

    PubMed

    Ahmadi-Noorbakhsh, Siavash; Azizi, Saeed; Dalir-Naghadeh, Bahram; Maham, Masoud

    2012-01-01

    Oxygen is an essential part of the most important metabolic pathways in aerobic organisms. Oxygen delivery is merely dependent on blood, rendering blood loss a devastating event. Traumatic pre-hospital liver bleeding is a major cause of early trauma deaths in human and animals, with no established therapeutic method yet. Increasing intra-abdominal pressure (IAP) has been shown to reduce liver bleeding by half. Although reduction of blood loss could be in favor of blood oxygen delivery, however, the complex interaction between increased IAP and respiratory mechanics during severe hemorrhagic shock remained unclear. We used a novel model of liver trauma in 16 rabbits and randomly assigned them to either normotensive abdomen group or increased IAP by fluid infusion (HA) groups (n=8 each). Liver size and the amount of liver injury were evaluated. Various blood oxygenation parameters were recorded. Both groups were identical in terms of the liver size and injury. The HA group had significantly lower shock index. Arterial oxygen capacity and oxygen content were higher in the HA group. No significant statistical difference was seen between groups in terms of abdominal perfusion pressure; alveolar pressure of oxygen; dissolved oxygen in blood plasma; alveolar to arterial oxygen tension gradient; arterial to alveolar oxygen pressure ratio; the ratio between partial pressure of arterial oxygen and fraction of inspired oxygen; and respiratory index. In conclusion, the novel therapeutic method of increasing IAP by fluid infusion in a rabbit model of liver hemorrhage preserved blood oxygenation better than the classic therapeutic method.

  11. The influence of artery wall curvature on the anatomical assessment of stenosis severity derived from fractional flow reserve: a computational fluid dynamics study.

    PubMed

    Govindaraju, Kalimuthu; Viswanathan, Girish N; Badruddin, Irfan Anjum; Kamangar, Sarfaraz; Salman Ahmed, N J; Al-Rashed, Abdullah A A A

    2016-11-01

    This study aims to investigate the influence of artery wall curvature on the anatomical assessment of stenosis severity and to identify a region of misinterpretation in the assessment of per cent area stenosis (AS) for functionally significant stenosis using fractional flow reserve (FFR) as standard. Five artery models of different per cent AS severity (70, 75, 80, 85 and 90%) were considered. For each per cent AS severity, the angle of curvature of the arterial wall varied from straight to an increasingly curved model (0°, 30°, 60°, 90° and 120°). Computational fluid dynamics was performed under transient physiologic hyperemic flow conditions to investigate the influence of artery wall curvature on the pressure drop and the FFR. The findings in this study may be useful in in vitro anatomical assessment of functionally significant stenosis. The FFR decreased with increasing stenosis severity for a given curvature of the artery wall. Moreover, a significant decrease in FFR was found between straight and curved models discussed for a given severity condition. These findings indicate that the curvature effect was included in the FFR assessment in contrast to minimum lumen area (MLA) or per cent AS assessment. The MLA or per cent AS assessment may lead to underestimation of stenosis severity. From this numerical study, an uncertainty region could be evaluated using the clinical FFR cutoff value of 0.8. This value was observed at 81.98 and 79.10% AS for arteries with curvature angles of 0° and 120° respectively. In conclusion, the curvature of the artery should not be neglected in in vitro anatomical assessment.

  12. Fuel nozzle tube retention

    DOEpatents

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  13. Stability and Retention.

    PubMed

    Will, Leslie A

    2016-01-01

    Stability of tooth position in the broader sense considers all the forces that may act on the tooth. Reitan reported that significant forces remained in the periodontium after tooth movement, and he carried out research that demonstrated residual stretching of the crestal periodontal fibers more than 7 months after tooth movement. Brain demonstrated that severing the fibers reduced the relapse in tooth position in dogs. Edwards published a series of papers exploring the effects of surgical transection of the gingival fibers on tooth stability, recommending that circumferential fiberotomy be performed in order to increase posttreatment tooth stability. Other researchers have suggested ways to increase the stability of the incisors, which are typically most prone to relapse. Peck and Peck recommended that interproximal reduction be done to broaden the contact point. Boese also recommended interproximal reduction as part of a four-pronged approach to retention.

  14. Fluid imbalance

    MedlinePlus

    ... up in the body. This is called fluid overload (volume overload). This can lead to edema (excess fluid in ... Water imbalance; Fluid imbalance - dehydration; Fluid buildup; Fluid overload; Volume overload; Loss of fluids; Edema - fluid imbalance; ...

  15. H 2O and CO 2 in kimberlitic fluid as recorded by diamonds and olivines in several Ekati Diamond Mine kimberlites, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Fedortchouk, Yana; Matveev, Sergei; Carlson, Jon A.

    2010-01-01

    Surface dissolution features on diamonds and Fourier Transform Infra Red spectroscopy (FTIR) of phenocrystal and xenocrystal olivines from kimberlites contain a record of magmatic fluid in kimberlite magmas. We investigated composition and behavior of kimberlitic fluid and the effect of volatiles on the eruption style and geology of kimberlites using microdiamonds and olivine concentrates from six kimberlite pipes with different lithologies and the character of diamond resorption (Ekati Diamond Mine, Northwest Territories, Canada). The study showed a clear correlation between the resorption style of diamond population of the kimberlites and the type of infrared (IR) spectra of their olivines. Four kimberlites have high quality diamonds with smooth regular surface features and high H 2O content of the olivines indicating the presence of H 2O-rich fluid during the emplacement. Fast ascent rates of fluid-rich magma can explain explosive eruption and filling the pipes with volcaniclastic kimberlite facies. Conversely, Grizzly and Leslie kimberlites have diamonds with complex sharp features diminishing diamond quality and indicating loss of the fluid. The slower ascent rates and less explosive eruption of the fluid-free magmas produced kimberlite pipes filled with magmatic facies kimberlite. Distinctive peaks in olivine IR spectra at 3356 and 3327 cm - 1 were found to correlate with the presence of hydrous magmatic fluid. Character of diamond morphology suggests that during the whole ascent of all six kimberlites, the magmatic fluid when present had a high H 2O:CO 2 ratio.

  16. Lung retention of cerium in humans.

    PubMed Central

    Pairon, J C; Roos, F; Iwatsubo, Y; Janson, X; Billon-Galland, M A; Bignon, J; Brochard, P

    1994-01-01

    A retrospective study was conducted to evaluate lung retention of particles containing cerium in subjects with and without previous occupational exposure to mineral dusts. Analytical transmission electron microscopy was performed on 459 samples of bronchoalveolar lavage (BAL) fluid and 75 samples of lung tissue. Study of the distribution of mineralogical species in human samples showed that particles containing cerium were encountered in less than 10% of subjects. The proportion of subjects with particles containing cerium in their biological samples was not different between controls and subjects with previous occupational exposure to fibrous or nonfibrous mineral dusts. This was considered as the background level of lung retention of cerium in the general population. By contrast, determination of the absolute concentration of particles containing cerium in BAL fluid and lung tissue samples showed that 1.2% (from BAL fluid) and 1.5% (from lung tissue) of subjects with previous exposure to mineral particles had high lung retention of particles containing cerium. This study is believed to be the first one in which lung retention of cerium was estimated in the general population. PMID:8130849

  17. Institutionalization of a Retention Model

    NASA Astrophysics Data System (ADS)

    Davis, E. J.; Campbell, A.

    2006-05-01

    Bowie State University and NASA Goddard Space Flight Center have, for the past 10 years, worked diligently together to enhance the science, mathematics, engineering and technology (SMET) domain. Efforts made, because of a Model Institutions for Excellence (MIE) Award, have changed the landscape of the SMET domain by increasing the retention and graduation rates, the number of students entering graduate and professional schools, and the number of students entering SMET related careers for minorities and women. Several initiatives a Scholarship Program, PRISEM Tutoring Center, Safety-net Program, Research emphasis, Focused Mentoring, a Summer Academy for accepted incoming students, a Bridge Program for students needing assistance being admitted to the University, the RISE Program and the Bowie State Satellite Operations and Control Center (BSOCC) provide the nurturing, mentoring, and opportunities for our students. As a result of efforts made, the retention rate has increase to approximately 80%, the graduation rate has increased 40%, and 85% of the SMET students are now interested or entering graduate and professional schools. Successes that have been documented by various assessment activities have led to the institutionalization of the Retention Model of the MIE Initiative. It is anticipated that University-wide application of the retention model will prove the incentives necessary to obtain similar results as the MIE Initiative.

  18. Disposal of drilling fluids

    SciTech Connect

    Bryson, W.R.

    1983-06-01

    Prior to 1974 the disposal of drilling fluids was not considered to be much of an environmental problem. In the past, disposal of drilling fluids was accomplished in various ways such as spreading on oil field lease roads to stabilize the road surface and control dust, spreading in the base of depressions of sandy land areas to increase water retention, and leaving the fluid in the reserve pit to be covered on closure of the pit. In recent years, some states have become concerned over the indescriminate dumping of drilling fluids into pits or unauthorized locations and have developed specific regulations to alleviate the perceived deterioration of environmental and groundwater quality from uncontrolled disposal practices. The disposal of drilling fluids in Kansas is discussed along with a newer method or treatment in drilling fluid disposal.

  19. Retention, retention, retention: targeting the young in CPR skills training!

    PubMed

    Roppolo, Lynn P; Pepe, Paul E

    2009-01-01

    The usefulness of basic cardiopulmonary resuscitation (CPR) training in school systems has been questioned, considering that young students may not have the physical or cognitive skills required to perform complex tasks correctly. In the study conducted by Fleishhackl and coworkers, students as young as 9 years were able to successfully and effectively learn basic CPR skills, including automated external defibrillator deployment, correct recovery position, and emergency calling. As in adults, physical strength may limit the depth of chest compressions and ventilation volumes given by younger individuals with low body mass index; however, skill retention is good. Training all persons across an entire community in CPR may have a logarithmic improvement in survival rates for out-of-hospital cardiac arrest because bystanders, usually family members, are more likely to know CPR and can perform it immediately, when it is physiologically most effective. Training captured audiences of trainees, such as the entire work-force of the community or the local school system, are excellent mechanisms to help achieve that goal. In addition to better retention with new half hour training kits, a multiplier effect can be achieved through school children. In addition, early training not only sets the stage for subsequent training and better retention, but it also reinforces the concept of a social obligation to help others.

  20. Bacteria facilitate prey retention by the pitcher plant Darlingtonia californica.

    PubMed

    Armitage, David W

    2016-11-01

    Bacteria are hypothesized to provide a variety of beneficial functions to plants. Many carnivorous pitcher plants, for example, rely on bacteria for digestion of captured prey. This bacterial community may also be responsible for the low surface tensions commonly observed in pitcher plant digestive fluids, which might facilitate prey capture. I tested this hypothesis by comparing the physical properties of natural pitcher fluid from the pitcher plant Darlingtonia californica and cultured 'artificial' pitcher fluids and tested these fluids' prey retention capabilities. I found that cultures of pitcher leaves' bacterial communities had similar physical properties to raw pitcher fluids. These properties facilitated the retention of insects by both fluids and hint at a previously undescribed class of plant-microbe interaction.

  1. Fluid management strategies in heart failure.

    PubMed

    Albert, Nancy M

    2012-04-01

    In patients with chronic heart failure, fluid retention (or hypervolemia) is often the stimulus for acute decompensated heart failure that requires hospitalization. The pathophysiology of fluid retention is complex and involves both hemodynamic and clinical congestion. Signs and symptoms of both hemodynamic and clinical congestion should be assessed serially during hospitalization. Core heart failure drug and cardiac device therapies should be provided, and ultrafiltration may be warranted. Critical care, intermediate care, and telemetry nurses have roles in both assessment and management of patients hospitalized with acute decompensated heart failure and fluid retention. Nurse administrators and managers have heightened their attention to fluid retention because the Medicare performance measure known as the risk-standardized 30-day all-cause readmission rate after heart failure hospitalization can be attenuated by fluid management strategies initiated by nurses during a patient's hospitalization.

  2. Drug Retention Times

    SciTech Connect

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  3. Mentorship: increasing retention probabilities.

    PubMed

    Leners, Debra Woodard; Wilson, Vicki W; Connor, Peggy; Fenton, Joanne

    2006-11-01

    Retaining nurses is a significant workforce issue. Experienced nurses in particular are getting harder to retain within hospitals and the discipline at large. One solution to boost retention is to give serious attention to professional socialization activities through contemporary nurse mentorship experiences. The authors contend that contemporary mentoring programmes, targeting developmental quality of life issues of the expert nurse, would appreciably benefit retention programmes within the hospital environment.

  4. Severe hyponatraemia in an amiloride/hydrochlorothiazide-treated patient.

    PubMed

    van Assen, S; Mudde, A H

    1999-03-01

    A 85-year-old woman treated with, among other drugs, a thiazide diuretic presented with a severe hyponatraemia. She met several of the criteria for SIADH and, besides drugs, no cause for SIADH was found. After stopping the thiazide diuretic and restricting fluid intake the patient recovered fully. It was later proved that the thiazide was the cause of the water intoxication by rechallenging the patient with a single dose of amiloride/hydrochlorothiazide 5/50 mg. This "thiazide provocation test" showed its usefulness in the differential diagnosis of suspected SIADH. Moreover, the test demonstrated the paradoxal effect of thiazide diuretics to cause water retention in susceptible patients.

  5. Safeguards Workforce Repatriation, Retention and Utilization

    SciTech Connect

    Gallucci, Nicholas; Poe, Sarah

    2015-10-01

    Brookhaven National Laboratory was tasked by NA-241 to assess the transition of former IAEA employees back to the United States, investigating the rate of retention and overall smoothness of the repatriation process among returning safeguards professionals. Upon conducting several phone interviews, study authors found that the repatriation process went smoothly for the vast majority and that workforce retention was high. However, several respondents expressed irritation over the minimal extent to which their safeguards expertise had been leveraged in their current positions. This sentiment was pervasive enough to prompt a follow-on study focusing on questions relating to the utilization rather than the retention of safeguards professionals. A second, web-based survey was conducted, soliciting responses from a larger sample pool. Results suggest that the safeguards workforce may be oversaturated, and that young professionals returning to the United States from Agency positions may soon encounter difficulties finding jobs in the field.

  6. Development of mucoadhesive sprayable gellan gum fluid gels.

    PubMed

    Mahdi, Mohammed H; Conway, Barbara R; Smith, Alan M

    2015-07-05

    The nasal mucosa provides a potentially good route for local and systemic drug delivery. However, the protective feature of the nasal cavity make intranasal delivery challenging. The application of mucoadhesive polymers in nasal drug delivery systems enhances the retention of the dosage form in the nasal cavity. Several groups have investigated using low acyl gellan as a drug delivery vehicle but only limited research however, has been performed on high acyl gellan for this purpose, despite its properties being more conducive to mucoadhesion. High acyl gellan produces highly elastic gels below 60°C which make it difficult to spray using a mechanical spray device. Therefore, in this study we have tried to address this problem by making fluid gels by introducing a shear force during gelation of the gellan polymer. These fluid gel systems contain gelled micro-particles suspended in a solution of un-gelled polymer. These systems can therefore behave as pourable viscoelastic fluids. In this study we have investigated the rheological behavior and mucoadhesion of fluid gels of two different types of gellan (high and low acyl) and fluid gels prepared from blends of high and low acyl gellan at a 50:50 ratio. The results demonstrated that by preparing fluid gels of high acyl gellan, the rheological properties were sufficient to spray through a standard nasal spray device. Moreover fluid gels also significantly enhance both high acyl and low acyl gellan mucoadhesion properties.

  7. Retention and Writing Instruction: Implications for Access and Pedagogy

    ERIC Educational Resources Information Center

    Powell, Pegeen Reichert

    2009-01-01

    In this article, the author offers a brief overview of retention scholarship and argues that there are several reasons composition studies professionals should pay attention to this area of research. She then considers how the problem of retention reframes and qualifies the issue of access to higher education, an issue that is central to the…

  8. Financial Literacy and Retention

    ERIC Educational Resources Information Center

    Adams, Ruth L.

    2006-01-01

    Higher education administrators know it is more cost-effective to keep students than to recruit them. Understanding financial literacy--and how it impacts student retention and persistence on the campuses--is an important concept for administrators to comprehend. Most students are not financially literate when they enter the world of higher…

  9. Tritium retention in TFTR

    SciTech Connect

    Dylla, H.F.; Wilson, K.L.

    1988-04-01

    This report discusses the materials physics related to D-T operation in TFTR. Research activities are described pertaining to basic studies of hydrogenic retention in graphite, hydrogen recycling phenomena, first-wall and limiter conditioning, surface analysis of TFTR first-wall components, and estimates of the tritium inventory.

  10. Secondary Retention Alternative.

    ERIC Educational Resources Information Center

    Baenen, Nancy R.; Hopkins, Patricia

    Two alternatives to retention in grade for secondary school students were evaluated in Austin (Texas). Both were designed to allow students who are potential retainees (PRs) to receive remediation in one semester. The Transitional Academic Program (TAP) allows PRs to enroll in ninth-grade courses while repeating eighth-grade courses they had…

  11. Principals Retention. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2005-01-01

    Many districts are struggling with the problem of administrator retention. Hoffman (2004) identifies some of the reasons for this: (1) Increased accountability expectations; (2) Diminished or static levels of resources to support reform efforts; (3) Greater administrator vulnerability to sanctions; (4) The complex demands of government and the…

  12. Data Show Retention Disparities

    ERIC Educational Resources Information Center

    Adams, Caralee J.; Robelen, Erik W.; Shah, Nirvi

    2012-01-01

    New nationwide data collected by the U.S. Department of Education's civil rights office reveal stark racial and ethnic disparities in student retentions, with black and Hispanic students far more likely than white students to repeat a grade, especially in elementary and middle school. The contrast is especially strong for African-Americans. In the…

  13. Implications for Uranus and Neptune of Electrical Conductivities of Fluid Hydrogen, Water, and Synthetic Uranus Measured Under Dynamic Quasi-Isentropic Compression up to 180 GPa and Several 1000 K

    NASA Astrophysics Data System (ADS)

    Nellis, W. J.

    2014-12-01

    Electrical conductivities of metallic fluid H and ionic fluids H2O and Synthetic Uranus (SU) have been measured experimentally under dynamic quasi-isentropic compression up to 180 GPa and several 1000 K. SU is a mixture of H2O, NH3 and C3H8O with composition representative of "Ice". Pressures P and temperatures T of the conductivity experiments were similar to P and T in interiors of Uranus and Neptune (U/N). Fluid H semiconducts at ~90 GPa and becomes a degenerate fluid metal with conductivity 2000/(ohm-cm) at 140 GPa, 0.64 g/cm3 and T/TF~0.01, where TF is Fermi temperature, conditions near the envelope/core boundaries of U/N. Metallization density is within a few% of the insulator-metal transition predicted by Wigner and Huntington in 1935. SU and water have conductivities of ~100/(ohm-cm) at 150 GPa. Podolak et al have shown a mixture of 75% Rock-25% Gas (by mass) behaves similarly to "pure" Ice in region that encompasses most mass of Uranus. The bandgap of water is predicted to close at 300 GPa and ~7000 K by Cavazonni et al. Models of pressure, temperature and density in U/N based on Voyager II gravity data have been developed by Helled et al. Stanley and Bloxham (SB) have developed MHD models that calculate non-dipolar and non-axisymmetric magnetic fields similar to those of U/N. The MHD models of SB assume that materials at planetary radii below the thin-shell dynamos that make the magnetic fields are stably stratified. The purpose of this paper is to develop a common picture for the deep interiors of U/N based on Voyager II gravity and magnetic data, measured electrical conductivities of planetary fluids, theoretical computations of interior conditions and the likely source of unusual magnetic fields, and extrapolation of existing experimental data for materials at 180 GPa to greater planetary depths. Main conclusions are the magnetic fields of U/N are probably made primarily by fluid metallic H at radii out to ~0.8 or more of U/N outer radii. Most of the

  14. Genetics Home Reference: chylomicron retention disease

    MedlinePlus

    ... Retention Disease MalaCards: chylomicron retention disease Merck Manual Consumer Version: Hypolipidemia Merck Manual Consumer Version: Overview of Malabsorption Orphanet: Chylomicron retention disease ...

  15. Methodological inaccuracies in clinical aortic valve severity assessment: insights from computational fluid dynamic modeling of CT-derived aortic valve anatomy

    NASA Astrophysics Data System (ADS)

    Traeger, Brad; Srivatsa, Sanjay S.; Beussman, Kevin M.; Wang, Yechun; Suzen, Yildirim B.; Rybicki, Frank J.; Mazur, Wojciech; Miszalski-Jamka, Tomasz

    2016-04-01

    Aortic stenosis is the most common valvular heart disease. Assessing the contribution of the valve as a portion to total ventricular load is essential for the aging population. A CT scan for one patient was used to create one in vivo tricuspid aortic valve geometry and assessed with computational fluid dynamics (CFD). CFD simulated the pressure, velocity, and flow rate, which were used to assess the Gorlin formula and continuity equation, current clinical diagnostic standards. The results demonstrate an underestimation of the anatomic orifice area (AOA) by Gorlin formula and overestimation of AOA by the continuity equation, using peak velocities, as would be measured clinically by Doppler echocardiography. As a result, we suggest that the Gorlin formula is unable to achieve the intended estimation of AOA and largely underestimates AOA at the critical low-flow states present in heart failure. The disparity in the use of echocardiography with the continuity equation is due to the variation in velocity profile between the outflow tract and the valve orifice. Comparison of time-averaged orifice areas by Gorlin and continuity with instantaneous orifice areas by planimetry can mask the errors of these methods, which is a result of the assumption that the blood flow is inviscid.

  16. Mobile Learning and Student Retention

    ERIC Educational Resources Information Center

    Fozdar, Bharat Inder; Kumar, Lalita S.

    2007-01-01

    Student retention in open and distance learning (ODL) is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not…

  17. Psychogenic urinary retention.

    PubMed

    Bird, J R

    1980-01-01

    The literature on psychogenic urinary retention is reviewed. 2 cases treated by analytical psychotherapy are reported, in which significant demand for physical punishment was revealed and seen as linked to unacceptable, unconscious sadistic and aggressive feelings. Some psychodynamic aspects of what is considered to be "a disturbance of internal body space' are discussed. Psychogenic urinary retention has received little attention in the literature. It may represent the uneasy position this disorder of bodily function occupies in clinical practice, with clear physical symptoms and associated psychological factors. The condition is more frequent in females, usually young adults. Case histories regularly record the placid, passive presentation of these patients, childhood enuresis and disturbed backgrounds. The diagnosis, "hysteric', is frequent and most psychodynamic evaluations suggest the symptom represents a displacement of unacceptable sexual wishes and impulse. 2 patients treated by analytical psychotherapy are reported who, whilst fulfilling many of the criteria already noted, additionally revealed an intense desire for physical punishment. This punitive demand had less to do with unacceptable sexual wishes, than guilt at repressed aggressive drives of considerable magnitude. The role of aggression in the genesis of psychogenic urinary retention has so far been little studied.

  18. ORTHODONTIC RETENTION. Studies of retention capacity, cost-effectiveness and long-term stability.

    PubMed

    Tynelius, Gudrun Edman

    2014-01-01

    gender had no significant influence on mandibular LII (Paper II, Figure 4 and Table 4). Paper III. The cost minimization analysis disclosed that although the three retention methods achieved clinically similar results, the associated societal costs differed. After two years of retention, the vacuum-formed retainer (VFR) in combination with a canine-to-canine retainer (CTC) was the least cost-effective retention appliance. Paper IV. After five years or more out of retention, the three retention methods had achieved equally favourable clinical results. Key conclusion and clinical implications. This study compared the short- and long-term outcomes of orthodontic retention by three different methods: a maxillary vacuum-formed retainer combined with a mandibular canine-to-canine retainer; a maxillary vacuum-formed retainer combined with stripping of the mandibular anterior teeth and a prefabricated positioner. All methods gave equally positive clinical results in both the short-term, i.e. after one and two years of retention, and in the long-term, five years or more post-retention. After two years of retention, the level of compliance affected the retention treatment result. However, no such effect was shown for body height, the severity of initial crowding or gender. Today, there is increasing emphasis on the importance of economic aspects of healthcare. Of the three methods evaluated in this study, the least cost-effective, after two years of retention, was a vacuum-formed retainer combined with a bonded canine-to-canine retainer. The clinical implication of this finding is that in patients meeting the inclusion criteria, interproximal stripping of the mandibular anterior teeth, or the use of a prefabricated positioner, are highly appropriate alternatives to a mandibular bonded canine-to-canine retainer. The overall conclusions are that there are a number of effective retention methods available and the clinician is not limited to routine use of a bonded mandibular canine

  19. Amniotic fluid

    MedlinePlus

    ... carefully. Removing a sample of the fluid through amniocentesis can provide information about the sex, health, and development of the fetus. Images Amniocentesis Amniotic fluid Polyhydramnios Amniotic fluid References Cunningham FG, ...

  20. Forebody and base region real-gas flow in severe planetary entry by a factored implicit numerical method. I - Computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Lombard, C. K.; Davy, W. C.; Green, M. J.

    1980-01-01

    A new code for the simulation of full (forebody and base region) flowfields about bluff bodies in the hypersonic regime of severe planetary entry is described. The present 'maximally conservative, maximally differenced' formulation of the unsteady compressible Navier-Stokes equations for 2-D axisymmetric 3-D flow is contrasted for stability with previous formulations of Viviand, Kutler, et al, and Thomas and Lombard. Discrete metric relations peculiar to the axisymmetric finite volume formulation are presented along with a general discussion of their relations to and consequences of failure to close computational cells. A computational mesh of curvilinear coordinate topology singular in the flow regime is presented that permits aligned capturing of the major physical features of the complex flowfield.

  1. Metalworking and machining fluids

    DOEpatents

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  2. Selenide retention by mackinawite.

    PubMed

    Finck, N; Dardenne, K; Bosbach, D; Geckeis, H

    2012-09-18

    The isotope (79)Se may be of great concern with regard to the safe disposal of nuclear wastes in deep geological repositories due to its long half-life and potential mobility in the geosphere. The Se mobility is controlled by the oxidation state: the oxidized species (Se(IV)) and (Se(VI)) are highly mobile, whereas the reduced species (Se(0) and Se(-II)) form low soluble solids. The mobility of this trace pollutant can be greatly reduced by interacting with the various barriers of the repository. Numerous studies report on the oxidized species retention by mineral phases, but only very scarce studies report on the selenide (Se(-II)) retention. In the present study, the selenide retention by coprecipitation with and by adsorption on mackinawite (FeS) was investigated. XRD and SEM analyses of the samples reveal no significant influence of Se on the mackinawite precipitate morphology and structure. Samples from coprecipitation and from adsorption are characterized at the molecular scale by a multi-edge X-ray absorption spectroscopy (XAS) investigation. In the coprecipitation experiment, all elements (S, Fe, and Se) are in a low ionic oxidation state and the EXAFS data strongly point to selenium located in a mackinawite-like sulfide environment. By contacting selenide ions with FeS in suspension, part of Se is located in an environment similar to that found in the coprecipitation experiment. The explanation is a dynamical dissolution-recrystallization mechanism of the highly reactive mackinawite. This is the first experimental study to report on selenide incorporation in iron monosulfide by a multi-edge XAS approach.

  3. Tritium retention in TFTR

    NASA Astrophysics Data System (ADS)

    Skinner, C. H.; Mueller, D.; Walters, R. T.; TFTR Team; Causey, R.; Luckhardt, S.; Hirooka, J.

    1996-11-01

    The large tritium inventories projected for ITER pose an important constraint in the design of plasma facing components and the selection of first wall materials. Three years of deuterium-tritium operation in TFTR has provided a special opportunity to address the issues of tritium retention in a tokamak environment. More than 18 kCi of tritium has been injected into the torus via neutral beam injection and gas puffs and approximately half of this amount was retained in the vacuum vessel.(C.H. Skinner et al.), PPPL 3172 (Jan 1995). Tritium has been successfully removed by glow discharges, exposure to room air and other techniques and it is not a constraint on continued operations. A vacuum opening is scheduled for September 1996 and we plan to extract samples of tritiated carbon dust and flakes from the limiter and vacuum vessel for elemental and chemical analysis. We will present the TFTR experience in tritium recycling, retention and removal and its implications for ITER.

  4. Intron retention as a component of regulated gene expression programs.

    PubMed

    Jacob, Aishwarya G; Smith, Christopher W J

    2017-04-08

    Intron retention has long been an exemplar of regulated splicing with case studies of individual events serving as models that provided key mechanistic insights into the process of splicing control. In organisms such as plants and budding yeast, intron retention is well understood as a major mechanism of gene expression regulation. In contrast, in mammalian systems, the extent and functional significance of intron retention have, until recently, remained greatly underappreciated. Technical challenges to the global detection and quantitation of transcripts with retained introns have often led to intron retention being overlooked or dismissed as "noise". Now, however, with the wealth of information available from high-throughput deep sequencing, combined with focused computational and statistical analyses, we are able to distinguish clear intron retention patterns in various physiological and pathological contexts. Several recent studies have demonstrated intron retention as a central component of gene expression programs during normal development as well as in response to stress and disease. Furthermore, these studies revealed various ways in which intron retention regulates protein isoform production, RNA stability and translation efficiency, and rapid induction of expression via post-transcriptional splicing of retained introns. In this review, we highlight critical findings from these transcriptomic studies and discuss commonalties in the patterns prevalent in intron retention networks at the functional and regulatory levels.

  5. 300 Area Building Retention Evaluation Mitigation Plan

    SciTech Connect

    D. J. McBride

    2007-07-03

    Evaluate the long-term retention of several facilities associated with the PNNL Capability Replacement Laboratory and other Hanfor mission needs. WCH prepared a mitigation plan for three scenarios with different release dates for specific buildings. The evaluations present a proposed plan for providing utility services to retained facilities in support of a long-term (+20 year) lifespan in addition to temporary services to buildings with specified delayed release dates.

  6. Boulder Valley Kindergarten Study: Retention Practices and Retention Effects.

    ERIC Educational Resources Information Center

    Shepard, Lorrie A.; Smith, Mary Lee

    Having implemented a policy that allowed schools to retain children in kindergarten an extra year, the Boulder Valley Public School District in Colorado conducted a study to determine the cognitive and emotional benefits of retention in kindergarten and the characteristics that led to decisions about retention. The study involved a research review…

  7. Fluid overpressures and strength of the sedimentary upper crust

    NASA Astrophysics Data System (ADS)

    Suppe, John

    2014-12-01

    The classic crustal strength-depth profile based on rock mechanics predicts a brittle strength σ1 -σ3 = κ(ρbar gz -Pf) that increases linearly with depth as a consequence of [1] the intrinsic brittle pressure dependence κ plus [2] an assumption of hydrostatic pore-fluid pressure, Pf = ρwgz. Many deep borehole stress data agree with a critical state of failure of this form. In contrast, fluid pressures greater than hydrostatic ρbar gz >Pf >ρw gz are normally observed in clastic continental margins and shale-rich mountain belts. Therefore we explore the predicted shapes of strength-depth profiles using data from overpressured regions, especially those dominated by the widespread disequilibrium-compaction mechanism, in which fluid pressures are hydrostatic above the fluid-retention depth zFRD and overpressured below, increasing parallel to the lithostatic gradient ρbar gz . Both brittle crustal strength and frictional fault strength below the zFRD must be constant with depth because effective stress (ρbar gz -Pf) is constant, in contrast with the classic linearly increasing profile. Borehole stress and fluid-pressure measurements in several overpressured deforming continental margins agree with this constant-strength prediction, with the same pressure-dependence κ as the overlying hydrostatic strata. The role of zFRD in critical-taper wedge mechanics and jointing is illustrated. The constant-strength approximation is more appropriate for overpressured crust than classic linearly increasing models.

  8. Drug Retention Times

    SciTech Connect

    None, None

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user. Based on anecdotal evidence, most people “party” during extended time away from the work environment. Therefore, the following scenarios were envisioned: (1) a person uses an illicit drug at a party on Saturday night (infrequent user); (2) a person uses a drug one time on Friday night and once again on Saturday night (infrequent user); and (3) a person uses a drug on Friday night, uses a drug twice on Saturday night, and once again on Sunday (frequent user).

  9. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  10. FLUID SELECTING APPARATUS

    DOEpatents

    Stinson, W.J.

    1958-09-16

    A valve designed to selectively sample fluids from a number of sources is described. The valve comprises a rotatable operating lever connected through a bellows seal to a rotatable assembly containing a needle valve, bearings, and a rotational lock. The needle valve is connected through a flexible tube to the sample fluid outlet. By rotating the lever the needle valve is placed over . one of several fluid sources and locked in position so that the fluid is traasferred through the flexible tubing and outlet to a remote sampling system. The fluids from the nonselected sources are exhausted to a waste line. This valve constitutes a simple, dependable means of selecting a sample from one of several scurces.

  11. Understanding Recruitment and Retention in Neurological Research

    PubMed Central

    Newberry, Alyssa; Sherwood, Paula; Hricik, Allison; Bradley, Sarah; Kuo, Jean; Crago, Elizabeth; Hoffman, Leslie A.; Given, Barbara A.

    2010-01-01

    Cognitive deficits in participants and the abrupt and traumatic way in which many neurological conditions present are two examples of the unique challenges in recruiting and retaining subjects with neurological injury for research studies. The purpose of this investigation was to identify obstacles to recruitment and retention in three ongoing research studies. These studies involve persons with neurological disorders across the continuum of care, from those newly diagnosed and with emergent presentation to those with more established, chronic neurological conditions. For the purpose of this analysis, we evaluated the effectiveness of the strategies employed to improve participation rates. The first study was an NIH funded project designed to identify biomarkers of vasospasm in persons (N=496) with aneurysmal subarachnoid hemorrhage (SAH) who presented to the neurovascular intensive care unit (NINR, RO1 NR004339). The purpose of the second study was to examine bio-behavioral interactions in family caregivers (N=59) of persons with a primary malignant brain tumor (PMBT) recruited in the community setting. The third project involved recruiting persons (N=1019) within an outpatient neurosurgical center to participate in a research registry. To determine differential effectiveness of strategies, consent and attrition rates were calculated at serial points over time in three studies and recruitment and retention strategies were compared. Sentinel time points in participants' disease trajectories played a key role in determining whether those who were approached to participate gave consent and were retained, particularly in the studies involving persons with aneurysmal SAH (consent = 85%; retention = 89%) and persons with PMBTs and their caregivers (consent = 68%; retention = 83%). In addition, several specific recruiter and interviewer training techniques were associated with higher recruitment and retention. Targeted strategies to improve participation rates are vital

  12. Toward a Record Retention Policy

    ERIC Educational Resources Information Center

    Vaughan, Jason

    2007-01-01

    An academic library working group was charged in 2005 to create a records retention schedule and policy applicable to records containing personally identifiable information of library patrons. This group conducted a survey and extensive research, culminating in an adopted library records retention schedule and policy implemented in 2006.

  13. Fiber length and orientation prevent migration in fluid filters

    NASA Technical Reports Server (NTRS)

    Reiman, P. A.

    1966-01-01

    Stainless steel fiber web filter resists fiber migration which causes contamination of filtered fluids. This filter is capable of holding five times more particulate matter before arbitrary cutoff pressure drop and shows excellent retention in fuel flow at high rates.

  14. Retention and Fading of Military Skills: Literature Review

    DTIC Science & Technology

    2000-04-01

    survey of the scientific and technical literature on models of skill fading and tools for determining when refresher training is required. In particular...the literature review investigated models for predicting skill retention relevant to the military domain. Skill retention can be defined as the...performance environments. • Type of task • Method of testing. • Individual differences. The literature review then examines several classes of models for

  15. Fluid handling equipment: A compilation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Devices and techniques used in fluid-handling and vacuum systems are described. Section 1 presents several articles on fluid lines and tubing. Section 2 describes a number of components such as valves, filters, and regulators. The last section contains descriptions of a number of innovative fluid-handling systems.

  16. Workforce Challenges and Retention Success Stories

    NASA Technical Reports Server (NTRS)

    Donohue, John T.

    2008-01-01

    This viewgraph document discusses the current and future challenges in building and retaining the required workforce of scientist and engineers for NASA. Specifically, the talk reviews the current situation at the Goddard Space Flight Center in Greenbelt, Maryland. Several programs at NASA for high school and college students to assist in inspiring the next generation of scientist and engineers are reviewed. The issue of retention of the best of the young scientists and engineers is also reviewed, with a brief review of several young engineers and their success with and for NASA.

  17. Rethinking Student Retention in Community Colleges.

    ERIC Educational Resources Information Center

    Wild, Linda; Ebbers, Larry

    2002-01-01

    States that student retention is significant for measuring institutional effectiveness in the prevailing environment of accountability and budgetary constraints. Presents recommendations for increasing retention, including training staff on retention issues, reviewing admission and advising strategies affecting minority populations, and piloting…

  18. Orthodontic retention: why when and how?

    PubMed

    McNally, M; Mullin, M; Dhopatkar, A; Rock, W P

    2003-10-01

    Retention is normally required after active orthodontic tooth movement to hold the teeth in their new positions. This article reviews the principles of orthodontic retention and describes common retention regimes and appliances.

  19. Retention and processing methods of nasal prosthesis.

    PubMed

    Goiato, Marcelo Coelho; Mancuso, Daniela Nardi; Zuccolotti, Bruna Carolina Rossati; Murakawa, Ana Cristina; Lima, Daniela Coelho de; Santos, Daniela Micheline dos; Andreotti, Agda Marobo

    2012-11-01

    Patients with congenital malformations, traumatic or pathological mutilation and maxillofacial developmental disorders can be restored aesthetically and emotionally by the production and use of facial prostheses. The aim of this study was to review the literature about the retention and processing methods of facial prostheses, and discuss their characteristics. A literature review on Medline (PubMed) database was performed by using the keywords "maxillofacial prosthesis, silicone, esin, pigment, cosmetic, prosthetic nose", based on articles published from 1956 to 2010. Several methods of retention, from adhesives to the placement of implants, and different processing methods such as laser, CAD/CAM and rapid prototyping technologies have been reported. There are advantages and disadvantages of each procedure, and none can be classified as better compared to others.

  20. Systems and methods for the detection of low-level harmful substances in a large volume of fluid

    SciTech Connect

    Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente

    2016-03-15

    A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.

  1. Predictors of Participant Retention in Infertility Treatment Trials

    PubMed Central

    Kuang, Hongying; Jin, Susan; Thomas, Tracey; Engmann, Lawrence; Hansen, Karl R.; Coutifaris, Christos; Casson, Peter; Christman, Gregory; Alvero, Ruben; Santoro, Nanette; Eisenberg, Esther; Diamond, Michael P; Legro, Richard S.; Zhang, Heping

    2015-01-01

    Objective To identify variables associated with retention (or dropout) in infertility clinical trials. Retention of subjects in randomized controlled clinical trials (RCTs) has received considerable attention, but there have been few consistent findings. Design Secondary analysis of data from RCTs. Setting RCTs conducted by academic medical centers in the U.S. Patients Women with polycystic ovary syndrome or couples with unexplained infertility, 18–39 years of age. Interventions This study is not an intervention study, but the patients in the original RCTs were treated with any or combination of metformin, clomiphene citrate, letrozole, and gonadotropins. Main Outcome Measure Successful retention versus dropout during the RCTs. Results Race, ethnicity, BMI, insurance coverage, history of smoking, and history of alcohol use were significantly associated with retention whether they were considered in bivariate analyses or a multivariable logistic model. Specifically, white race, higher income, having graduate degrees, normal weight, better insurance coverage, non-smokers, and those who reported current use of alcohol at the start of the trial, had higher retention rates. Conclusion We identified several additive and persistent predictors of retention that can be used to guide the conduct of RCTs and improve the retention rate. Given the limitation of our association analysis, methodologically sound and theoretically grounded research are warranted so that high quality data can be collected to improve our understanding on the causes of dropout. PMID:26354094

  2. Fluid Mechanics.

    ERIC Educational Resources Information Center

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  3. Retention in orthodontics.

    PubMed

    Johnston, C D; Littlewood, S J

    2015-02-16

    Retention is necessary following orthodontic treatment to prevent relapse of the final occlusal outcome. Relapse can occur as a result of forces from the periodontal fibres around the teeth which tend to pull the teeth back towards their pre-treatment positions, and also from deflecting occlusal contacts if the final occlusion is less than ideal. Age changes, in the form of ongoing dentofacial growth, as well as changes in the surrounding soft tissues, can also affect the stability of the orthodontic outcome. It is therefore essential that orthodontists, patients and their general dental practitioners understand the importance of wearing retainers after orthodontic treatment. This article will update the reader on the different types of removable and fixed retainers, including their indications, duration of wear, and how they should be managed in order to minimise any unwanted effects on oral health and orthodontic outcomes. The key roles that the general dental practitioner can play in supporting their patients wearing orthodontic retainers are also emphasised.

  4. Data Retention and Anonymity Services

    NASA Astrophysics Data System (ADS)

    Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

    The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

  5. Electrorheological fluids

    SciTech Connect

    Adolf, D.; Anderson, R.; Garino, T.; Halsey, T.C.; Hance, B.; Martin, J.E.; Odinek, J.

    1996-10-01

    An Electrorheological fluid is normally a low-viscosity colloidal suspension, but when an electric field is applied, the fluid undergoes a reversible transition to a solid, being able to support considerable stress without yield. Commercial possibilities for such fluids are enormous, including clutches, brakes, valves,shock absorbers, and stepper motors. However, performance of current fluids is inadequate for many proposed applications. Our goal was to engineer improved fluids by investigating the key technical issues underlying the solid-phase yield stress and the liquid to solid switching time. Our studies focused on field-induced interactions between colloidal particles that lead to solidification, the relation between fluid structure and performance (viscosity, yield stress), and the time evolution of structure in the fluid as the field is switched on or off.

  6. Post-operative urinary retention.

    PubMed

    Steggall, Martin; Treacy, Colm; Jones, Mark

    Urinary retention is a common complication of surgery and anaesthesia. The risk of post-operative urinary retention is increased following certain surgical procedures and anaesthetic modalities, and with patients' advancing age. Patients at increased risk of post-operative urinary retention should be identified before surgery or the condition should be identified and treated in a timely manner following surgery. If conservative measures do not help the patient to pass urine, the bladder will need to be drained using either an intermittent catheter or an indwelling urethral catheter, which can result in catheter-associated urinary tract infections. This article provides an overview of normal bladder function, risk factors for developing post-operative urinary retention, and treatment options. Guidance drawn from the literature aims to assist nurses in identifying at-risk patients and inform patient care.

  7. EA Shuttle Document Retention Effort

    NASA Technical Reports Server (NTRS)

    Wagner, Howard A.

    2010-01-01

    This slide presentation reviews the effort of code EA at Johnson Space Center (JSC) to identify and acquire databases and documents from the space shuttle program that are adjudged important for retention after the retirement of the space shuttle.

  8. Diversity and Retention in Engineering

    ERIC Educational Resources Information Center

    Davis, Cinda-Sue G.; Finelli, Cynthia J.

    2007-01-01

    The authors describe three initiatives designed to increase the academic achievement and retention of historically underrepresented students (including females and underrepresented students of color) in engineering. (Contains 2 tables.)

  9. Pulmonary retention of coal dusts

    SciTech Connect

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  10. For-Profit versus Nonprofit Colleges: A Predictive Study of Student Retention in Two-Year Community Colleges

    ERIC Educational Resources Information Center

    Daly, Jon C.

    2013-01-01

    Student retention has been a significant issue in higher education for several decades. "Two-year colleges" tend to have lower retention rates than four-year colleges (Seidman, 2005, ). Low retention is a problem in both two-year for-profit and nonprofit colleges. The purpose of this study was to ascertain the predictors of retention…

  11. Turnover: strategies for staff retention.

    PubMed

    SnowAntle, S

    1990-01-01

    This discussion has focused on a number of areas where organizations may find opportunities for more effectively managing employee retention. Given the multitude of causes and consequences, there is no one quick fix. Effective management of employee retention requires assessment of the entire human resources process, that is, recruitment, selection, job design, compensation, supervision, work conditions, etc. Regular and systematic diagnosis of turnover and implementation of multiple strategies and evaluation are needed (Mobley, 1982).

  12. Bortezomib-induced Severe Congestive Heart Failure

    PubMed Central

    Jerkins, James H.; Suciu, Anca; Mazimba, Sula; Calvo, Alejandro

    2010-01-01

    The clinical manifestations of anti-cancer drug associated cardiac side effects are diverse and can range from acutely induced cardiac arrhythmias to severe contractile dysfunction, and potentially fatal heart failure. Anthracyclines and trastuzumab cardiac toxicity have been well described and left ventricular ejection fraction (LVEF) evaluation is commonly performed before their use. Bortezomib (Velcade), a potent, specific and reversible proteasome inhibitor is approved for treatment of multiple myeloma (MM). The incidence of cardiac failure associated with bortezomib therapy in clinical trials remains incidental. Acute exacerbation of pre-existing congestive cardiac failure has been associated with this therapy but de novo cardiomyopathy has been reported in only one patient receiving bortezomib for small cell lung cancer. As a result, cardiac evaluation is not normally ordered before its use. We describe a 50-year-old female with newly diagnosed MM and no risk factors for cardiac disease that unexpectedly developed florid heart failure after 2 cycles of bortezomib and low-dose dexamethasone. 2-D echocardiogram showed dilated cardiomyopathy with severely decreased LVEF; no changes consistent with amyloid deposits or myocardial scarring were described. Coronary angiogram ruled out coronary artery disease. The mechanism of bortezomib-induced cardiomyopathy has been postulated to be through fluid retention. Based on literature review we hypothesize that the disruption of the ubiquitin-proteasome system by bortezomib may cause cardiomyopathy and severe cardiac failure. As Bortezomib is a new and promising therapy for MM patients, we recommend routinely monitoring cardiac parameters in patients undergoing this treatment.

  13. Multiphase fluid characterization system

    SciTech Connect

    Sinha, Dipen N.

    2014-09-02

    A measurement system and method for permitting multiple independent measurements of several physical parameters of multiphase fluids flowing through pipes are described. Multiple acoustic transducers are placed in acoustic communication with or attached to the outside surface of a section of existing spool (metal pipe), typically less than 3 feet in length, for noninvasive measurements. Sound speed, sound attenuation, fluid density, fluid flow, container wall resonance characteristics, and Doppler measurements for gas volume fraction may be measured simultaneously by the system. Temperature measurements are made using a temperature sensor for oil-cut correction.

  14. Retention Rate by Ethnicity. Information Capsule.

    ERIC Educational Resources Information Center

    Baldwin, Anne

    This document discusses retention rate based on ethnicity for Miami-Dade Community College (M-DCC) for December 2002. The study found that the 2001 Fall-Spring retention rates increased among all ethnic groups. The total college retention rate rose by 2.7 percentage points to 75.2%. Among individual groups, the highest retention rate of 76.9% was…

  15. [Fluid therapy in acute pancreatitis].

    PubMed

    de-Madaria, Enrique

    2013-12-01

    Severe acute pancreatitis (AP) is associated with an increased need for fluids due to fluid sequestration and, in the most severe cases, with decreased peripheral vascular tone. For several decades, clinical practice guidelines have recommended aggressive fluid therapy to improve the prognosis of AP. This recommendation is based on theoretical models, animal studies, and retrospective studies in humans. Recent studies suggest that aggressive fluid administration in all patients with AP could have a neutral or harmful effect. Fluid therapy based on Ringer's lactate could improve the course of the disease, although further studies are needed to confirm this possibility. Most patients with AP do not require invasive monitoring of hemodynamic parameters to guide fluid therapy administration. Moreover, the ability of these parameters to improve prognosis has not been demonstrated.

  16. Fuel retention studies on MAST

    NASA Astrophysics Data System (ADS)

    Mast Team Huang, J.; Lisgo, S.; Maddison, G.

    2011-08-01

    Fuel retention has been studied on MAST using gas-balance analysis. With 8-15 min of inter-shot helium glow-discharge cleaning (4He-GDC), the wall retention fraction stays very high (>90%) during the flat-top of the plasma current, indicating this component is dominant during the discharge. Recovery of wall conditioning with 4He-GDC suggests the retention process is dominated by direct implantation of particles in shallow surface layers. The effect of 4He-GDC duration on the particle balance has also been investigated. It is shown that when there was no preceding 4He-GDC, the wall pumping capacity was reduced, causing higher plasma density and tank pressure for the next shot.

  17. CHLORIDE RETENTION IN EXPERIMENTAL HYDRONEPHROSIS

    PubMed Central

    Keith, Norman M.; Pulford, D. Schuyler

    1923-01-01

    1. In acute experimental hydronephrosis chloride retention occurs as well as retention of water, urea, and phenolsulfonephthalein. 2. If both water and chlorides are retained there may be no appreciable rise in the plasma chloride content. 3. When chlorides are retained, but not water, the chloride content of the plasma rises strikingly. 4. After the removal of the ureteral obstruction in acute hydronephrosis all renal functions, water, urea, and chloride excretion, may be rapidly restored in equal degree, or the chlorides may be retained temporarily while there is free excretion of water and urea. 5. In chronic hydronephrosis adequate daily excretion of urea and chlorides may be maintained by a compensatory polyuria. 6. Chloride retention or an abnormal chloride excretion may occur in certain renal lesions when there is no change in the urea, phenolsulfonephthalein, or water excretion. PMID:19868720

  18. Lake retention of manufactured nanoparticles.

    PubMed

    Koelmans, A A; Quik, J T K; Velzeboer, I

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hydraulic loadings covered the widest possible range among existing lakes. Sedimentation accounted for natural colloid as well as suspended solid settling regimes. An ENP-specific mixed sedimentation regime is proposed. This regime combines ENP sedimentation through slow settling with natural colloids from the water column, with faster settling with suspended solids from a selected part of the water column. Although sedimentation data and hydrodynamic concepts as such were not new, their first time combination or application to ENPs shows in which cases lake retention is important for these particles. In combination with ENP emission data, lake retention translates directly into potential risks of ENPs for lake benthic communities.

  19. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Lauriie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Ribeiro, L.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Johnston, S.; Ploutz-Snyder, R.; Smith, S.

    2016-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low-Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 50% of ISS astronauts experienced more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's preflight conditions and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. METHODS: We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by

  20. Wellbore fluid

    SciTech Connect

    Dorsey, D.L.; Corley, W.T.

    1983-12-27

    A clay-based or clay-free aqueous thixotropic wellbore fluid having improved fluid loss control, desirable flow characteristics and low shale sensitivity for use in drilling a well comprising water or a brine base including an effective amount of an additive comprising a crosslinked potato starch, a heteropolysaccharide derived from a carbohydrate by bacteria of the genus Xanthomonas, and hydroxyethylcellulose or carboxymethylcellulose, is disclosed. This drilling fluid has been found to be nondamaging to the formations through which the well is drilled.

  1. Reimagining the Retention Problem: Moving Our Thinking from End-Product to By-Product

    ERIC Educational Resources Information Center

    Siegel, Michael J.

    2011-01-01

    Over the past several decades, college-student retention has arguably been the most intensely studied issue in academe. Though the body of retention literature grows ever larger, no one model adequately explains the process by which college students make a decision to leave an institution or to persist to graduation. And while no magic bullet…

  2. Reducing the Retention Rate among Kindergarten, First, and Second Grade Students.

    ERIC Educational Resources Information Center

    Turco, Angela

    An intervention project sought to lower the grade retention rates of kindergarten, first-, and second-grade students in one New Jersey school district. During three school years, 1987-1990, the retention rate was 7 percent of the total population of these grades. An exploration of causes identified several possible factors, including: (1) lack of…

  3. Undergraduate STEM Achievement and Retention: Cognitive, Motivational, and Institutional Factors and Solutions

    ERIC Educational Resources Information Center

    Cromley, Jennifer G.; Perez, Tony; Kaplan, Avi

    2016-01-01

    Student cognition and motivation, as well as institutional policies, determine student course grades and retention in science, technology, engineering, and mathematics (STEM) majors. Regarding cognition, study skills relate to course grades, and grades relate to retention in STEM. Several aspects of motivation are related to both grades and…

  4. Evaluating the Impact of National Educational Policy to Reduce Retention and Increase Achievement in Compulsory Education

    ERIC Educational Resources Information Center

    Barata, M. Clara; Calheiros, M. Manuela; Patrício, Joana Nunes; Graça, João; Lima, M. Luisa

    2015-01-01

    Despite the accumulated evidence that retention is an ineffective and potentially harmful remedial strategy, several countries struggle with high levels of retention in compulsory schooling. This article provides evidence of the impact of the Portuguese national educational policy "Programa Mais Sucesso Escolar" (PMSE) using class size,…

  5. Advancing the Science of Recruitment and Retention of Ethnically Diverse Populations

    ERIC Educational Resources Information Center

    Napoles, Anna M.; Chadiha, Letha A.

    2011-01-01

    We highlight several critical challenges that must be addressed to accelerate the advancement of the science on recruitment and retention of ethnically diverse older adults into health research. These include the relative lack of attention by researchers to methodological issues related to recruitment and retention of ethnically diverse…

  6. Fluid resuscitation in acute pancreatitis

    PubMed Central

    Aggarwal, Aakash; Manrai, Manish; Kochhar, Rakesh

    2014-01-01

    Acute pancreatitis remains a clinical challenge, despite an exponential increase in our knowledge of its complex pathophysiological changes. Early fluid therapy is the cornerstone of treatment and is universally recommended; however, there is a lack of consensus regarding the type, rate, amount and end points of fluid replacement. Further confusion is added with the newer studies reporting better results with controlled fluid therapy. This review focuses on the pathophysiology of fluid depletion in acute pancreatitis, as well as the rationale for fluid replacement, the type, optimal amount, rate of infusion and monitoring of such patients. The basic goal of fluid epletion should be to prevent or minimize the systemic response to inflammatory markers. For this review, various studies and reviews were critically evaluated, along with authors’ recommendations, for predicted severe or severe pancreatitis based on the available evidence. PMID:25561779

  7. How Students "Stay the Course": Retention Practices in Higher Education

    ERIC Educational Resources Information Center

    Kurantowicz, Ewa; Nizinska, Adrianna

    2013-01-01

    The article is based on the results of research carried out under the RANLHE project in several Polish academic institutions. Applying the biographical research approach, the project aimed to explore and understand the access and retention-related experiences of non-traditional students. In a study of non-traditional students, three distinct…

  8. Classroom Management for Student Retention.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    This guidebook recommends methods for teachers to use to improve teacher-student interaction in the classroom, as a means of increasing student retention. Chapter I introduces eight major systems of classroom management which teachers may use as their values and the classroom situation dictate: "Behavior Modification,""Reality Therapy,""Discipline…

  9. Meeting Individual Needs Fosters Retention.

    ERIC Educational Resources Information Center

    Artman, Johanne I.; Gore, Robert C.

    A 1991 study of non-returning students at Del Mar College (DMC), in Corpus Christi, Texas, revealed that only 37.9% of these students were actual dropouts (i.e., had failed to accomplish their educational goals, and had no plans to take up further study). Retention studies conducted in Texas between 1985 and 1989 have shown that DMC has…

  10. Strategies for improving employee retention.

    PubMed

    Verlander, Edward G; Evans, Martin R

    2007-03-28

    This article proposes a solution to the perennial problem of talent retention in the clinical laboratory. It includes the presentation of 12 strategies that may be used to significantly improve institutional identity formation and establishment of the psychological contract that employees form with laboratory management. Identity formation and psychological contracting are deemed as essential in helping reduce employee turnover and increase retention. The 12 conversational strategies may be used as a set of best practices for all employees, but most importantly for new employees, and should be implemented at the critical moment when employees first join the laboratory. This time is referred to as "retention on-boarding"--the period of induction and laboratory orientation. Retention on-boarding involves a dialogue between employees and management that is focused on the psychological, practical, cultural, and political dimensions of the laboratory. It is placed in the context of the modern clinical laboratory, which is faced with employing and managing Generation X knowledge workers. Specific topics and broad content areas of those conversations are outlined.

  11. Implicit Memory: Retention without Remembering.

    ERIC Educational Resources Information Center

    Roediger, Henry L., III

    1990-01-01

    Reviews recent research on retention that is demonstrated without conscious recollection, such as the ability to tie shoelaces or drive a car. Suggests that future research in this field may have implications for such educational issues as the transfer of training and the carryover of abstract classroom learning to problems in other contexts. (EVL)

  12. Maslow's Hierarchy and Student Retention.

    ERIC Educational Resources Information Center

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  13. A Research Study in Retention.

    ERIC Educational Resources Information Center

    Knibbe, Marie Vannozzi; Dusewicz, Russell A.

    A study of the Center for Literacy's (CFL) program was conducted to provide information on retention and attrition in an urban, open-entry/open-exit, individualized, goal-based literacy program. An exploratory analysis that used student and tutor records from 1985 through 1989 provided a summary of demographics and attendance patterns. This…

  14. Three Recruitment and Retention Surveys.

    ERIC Educational Resources Information Center

    Bronx Community Coll., NY.

    This three-part report summarizes methodology and findings of three recruitment and retention studies conducted by the Bronx Community College (BCC) during 1979-1980. Part I examines a survey of enrolled students conducted to determine student attitudes toward BCC, the services that were most in demand, the reasons for attending BCC, and student…

  15. Academic Advising for Retention Purposes.

    ERIC Educational Resources Information Center

    Kazazes, Barbara A.

    An effective academic advising system can assist in the retention of two-year college students; however, the institution and its faculty must be committed to providing such a system. Establishing a successful advising system would require the following: (1) a clear distinction must be made between academic advising and course scheduling; (2)…

  16. Course Retention Analysis. Focus Study.

    ERIC Educational Resources Information Center

    Mount San Antonio Coll., Walnut, CA.

    A study was conducted at Mount San Antonio College (MSAC), California, to analyze patterns in credit course retention between fall 1986 and spring 1989. The study investigated the development of course prerequisites based on faculty perceptions of the skills necessary for success and minimal skill levels associated with success; student assessment…

  17. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Laurie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Gunga, H.; Johnston, S.; Westby, C.; Ribeiro, L.; Ploutz-Snyder, R.; Smith, S.

    2015-01-01

    INTRODUCTION: Mechanisms responsible for the ocular structural and functional changes that characterize the visual impairment and intracranial pressure (ICP) syndrome (VIIP) are unclear, but hypothesized to be secondary to the cephalad fluid shift experienced in spaceflight. This study will relate the fluid distribution and compartmentalization associated with long-duration spaceflight with VIIP symptoms. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, can be predicted preflight with acute hemodynamic manipulations, and also if lower body negative pressure (LBNP) can reverse the VIIP effects. METHODS: Physiologic variables will be examined pre-, in- and post-flight in 10 International Space Station crewmembers including: fluid compartmentalization (D2O and NaBr dilution); interstitial tissue thickness (ultrasound); vascular dimensions and dynamics (ultrasound and MRI (including cerebrospinal fluid pulsatility)); ocular measures (optical coherence tomography, intraocular pressure, ultrasound); and ICP measures (tympanic membrane displacement, otoacoustic emissions). Pre- and post-flight measures will be assessed while upright, supine and during 15 deg head-down tilt (HDT). In-flight measures will occur early and late during 6 or 12 month missions. LBNP will be evaluated as a countermeasure during HDT and during spaceflight. RESULTS: The first two crewmembers are in the preflight testing phase. Preliminary results characterize the acute fluid shifts experienced from upright, to supine and HDT postures (increased stroke volume, jugular dimensions and measures of ICP) which are reversed with 25 millimeters Hg LBNP. DISCUSSION: Initial results indicate that acute cephalad fluid shifts may be related to VIIP symptoms, but also may be reversible by LBNP. The effect of a chronic fluid shift has yet to be evaluated. Learning Objectives: Current spaceflight VIIP research is described

  18. Cold enzymatic bleaching of fluid whey.

    PubMed

    Campbell, R E; Drake, M A

    2013-01-01

    Chemical bleaching of fluid whey and retentate with hydrogen peroxide (HP) alone requires high concentrations (100-500 mg of HP/kg) and recent studies have demonstrated that off-flavors are generated during chemical bleaching that carry through to spray-dried whey proteins. Bleaching of fluid whey and retentate with enzymes such as naturally present lactoperoxidase or an exogenous commercial peroxidase (EP) at cold temperatures (4°C) may be a viable alternative to traditional chemical bleaching of whey. The objective of this study was to determine the optimum level of HP for enzymatic bleaching (both lactoperoxidase and EP) at 4°C and to compare bleaching efficacy and sensory characteristics to HP chemical bleaching at 4°C. Selected treatments were subsequently applied for whey protein concentrate with 80% protein (WPC80) manufacture. Fluid Cheddar whey and retentate (80% protein) were manufactured in triplicate from pasteurized whole milk. The optimum concentration of HP (0 to 250 mg/kg) to activate enzymatic bleaching at 4°C was determined by quantifying the loss of norbixin. In subsequent experiments, bleaching efficacy, descriptive sensory analysis, and volatile compounds were monitored at selected time points. A control with no bleaching was also evaluated. Enzymatic bleaching of fluid whey and retentate at 4°C resulted in faster bleaching and higher bleaching efficacy (color loss) than bleaching with HP alone at 250 mg/kg. Due to concentrated levels of naturally present lactoperoxidase, retentate bleached to completion (>80% norbixin destruction in 30 min) faster than fluid whey at 4°C (>80% norbixin destruction in 12h). In fluid whey, the addition of EP decreased bleaching time. Spray-dried WPC80 from bleached wheys, regardless of bleaching treatment, were characterized by a lack of sweet aromatic and buttery flavors, and the presence of cardboard flavor concurrent with higher relative abundance of 1-octen-3-ol and 1-octen-3-one. Among enzymatically

  19. Electrorheological fluids

    SciTech Connect

    Halsey, T.C.; Martin, J.E.

    1993-10-01

    An electrorheological fluid is a substance whose form changes in the presence of electric fields. Depending on the strength of the field to which it is subjected, an electrorheological fluid can run freely like water, ooze like honey or solidify like gelatin. Indeed, the substance can switch from ne state to another within a few milliseconds. Electrorheological fluids are easy to make; they consist of microscopic particles suspended in an insulating liquid. Yet they are not ready for most commercial applications. They tend to suffer from a number of problems, including structural weakness as solids, abrasiveness as liquids and chemical breakdown, especially at high temperatures. Automotive engineers could imagine, for instance, constructing an electrorheological clutch. It was also hoped that electrorheological fluids would lead to valveless hydraulic systems, in which solidifying fluid would shut off flow through a thin section of pipe. Electrorheological fluids also offer the possibility of a shock absorber that provides response times of milliseconds and does not require mechanical adjustments. 3 refs.

  20. A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants

    NASA Astrophysics Data System (ADS)

    Gaume, Laurence; Forterre, Yoel

    2008-07-01

    We study the rheology of the digestive fluid secreted by the carnivorous pitcher plants Nepenthes rafflesiana and its role in the mechanism of insects trapping. Using a combination of physical measurements (surface tension, wetting properties, extensional and shear rheometry), insects bioessays and high-speed video, we show that the digestive fluid of Nepenthes rafflesiana is a highly viscoelastic fluid and that this property is crucial for the retention of insect in its trap. Trapping efficiency is shown to remain strong even when the fluid is highly diluted by water, as long as the elastic relaxation time of the fluid is higher than the typical time scale of insect movements (large Deborah numbers).

  1. Queuing register uses fluid logic elements

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Queuing register /a multistage bit-shifting device/ uses a series of pure fluid elements to perform the required logic operations. The register has several stages of three-state pure fluid elements combined with two-input NOR gates.

  2. Population Ration, Intermarriage and Mother Tongue Retention

    ERIC Educational Resources Information Center

    Kuo, Eddie C. Y.

    1978-01-01

    An explanatory model of the relationship between mother tongue retention, population ratio, and intermarriage is presented. In general, data collected on mother tongue retention in Singapore, a multilingual and multiethnic society, support the proposed model. (DS)

  3. Fluid Management System (FMS) fluid systems overview

    NASA Technical Reports Server (NTRS)

    Baird, R. S.

    1990-01-01

    Viewgraphs on fluid management system (FMS) fluid systems overview are presented. Topics addressed include: fluid management system description including system requirements (integrated nitrogen system, integrated water system, and integrated waste gas system) and physical description; and fluid management system evolution.

  4. Magnetic Fluids--Part 2.

    ERIC Educational Resources Information Center

    Hoon, S. B.; Tanner, B. K.

    1985-01-01

    Continues a discussion of magnetic fluids by providing background information on and procedures for conducting several demonstrations. Indicates that, with a little patience and ingenuity, only modest magnetic fields and about 20 ml of low-viscosity, commercial magnetite-water-based magnetic fluid are required. (JN)

  5. Tritium retention in reduced-activation ferritic/martensitic steels

    SciTech Connect

    Hatano, Y.; Abe, S.; Matsuyama, M.; Alimov, V.K.; Spitsyn, A.V.; Bobyr, N.P.; Cherkez, D.I.; Khripunov, B.I.; Golubeva, A.V.; Ogorodnikova, O.V.; Klimov, N.S.; Chernov, V.M.; Oyaidzu, M.; Yamanishi, T.

    2015-03-15

    Reduced-activation ferritic/martensitic (RAFM) steels are structural material candidates for breeding blankets of future fusion reactors. Therefore, tritium (T) retention in RAFM steels is an important problem in assessing the T inventory of blankets. In this study, specimens of RAFM steels were subjected to irradiation of 20 MeV W ions to 0.54 displacements per atom (dpa), exposure to high flux D plasmas at 400 and 600 K and that to pulsed heat loads. The specimens thus prepared were exposed to DT gas at 473 K. Despite severe modification in the surface morphology, heat loads had negligible effects on T retention. Significant increase in T retention at the surface and/or subsurface was observed after D plasma exposure. However, T trapped at the surface/subsurface layer was easily removed by maintaining the specimens in the air at about 300 K. Displacement damage led to increase in T retention in the bulk due to the trapping effects of defects, and T trapped was stable at 300 K. It was therefore concluded that displacement damages had the largest influence on T retention under the present conditions.

  6. 12 CFR 202.12 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 2 2011-01-01 2011-01-01 false Record retention. 202.12 Section 202.12 Banks... OPPORTUNITY ACT (REGULATION B) § 202.12 Record retention. (a) Retention of prohibited information. A creditor...) Applications. For 25 months (12 months for business credit, except as provided in paragraph (b)(5) of...

  7. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  8. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  9. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  10. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  11. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Retention register. 351.404 Section 351... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register...

  12. Persistence-Retention. Snapshot™ Report, Spring 2015

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2015

    2015-01-01

    This Snapshot Report offers information on student persistence and retention rates for 2009-2013. It offers data on the following: (1) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year Private Nonprofit Institutions; (2) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year…

  13. Persistence-Retention. Snapshot™ Report, Spring 2014

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2014

    2014-01-01

    This snapshot report provides information on student persistence and retention rates for Spring 2014. Data is presented in tabular format on the following: (1) First-Year Persistence and Retention Rates by Starting Enrollment Intensity (all institutional sectors); (2) First-Year Persistence and Retention Rates by Age at College Entry (all…

  14. Reframing Retention Strategy: A Focus on Progress

    ERIC Educational Resources Information Center

    Spittle, Brian

    2013-01-01

    Few words have dominated the vocabulary of college retention as has the word "persistence." Many institutions still struggle to engage faculty and administrators in building campuswide retention efforts, to find the organizational levers that translate the abstractions and complexities of retention theory into scalable and durable initiatives, and…

  15. Reframing Retention Strategy: A Focus on Profile

    ERIC Educational Resources Information Center

    Kalsbeek, David H.; Zucker, Brian

    2013-01-01

    Over 35 years of retention theory and literature have acknowledged the importance of institutional and student profiles in accounting for cross-sectional differences in retention and completion rates between types of colleges and universities. The first "P" within a 4 Ps framework of student retention--"profile"--recognizes that an institution's…

  16. Designing Online Courses to Promote Student Retention

    ERIC Educational Resources Information Center

    Dietz-Uhler, Beth; Fisher, Amy; Han, Andrea

    2008-01-01

    Although the issue of student retention is a campus-wide one, it is of special interest in online distance learning courses, where retention rates are reported to be lower than in face-to-face classes. Among the explanations and theories of retention rates in online courses, one that struck us as most useful is a structural one, namely, course…

  17. Do We Have a Retention Problem ... Or Do We Have a Problem "about" Retention?

    ERIC Educational Resources Information Center

    Butler, Lawrence

    2011-01-01

    This paper deals with the "problem" of student retention in higher education. But unlike most, this paper focuses not on the problem of retention "per se" but rather on how institutional leaders think about student retention, completion, and success--how the way they frame their concerns about retention can give rise to a different sort of…

  18. RETENTION OF HALOCARBONS ON A HEXAFLUOROPROPYLENE EPOXIDE-MODIFIED GRAPHITIZED CARBON BLACK - IV. PROPANE- BASED COMPOUNDS

    EPA Science Inventory

    The retention characteristics of 25 propane-based bromofluorocarbon, chlorocarbon, chlorofluorocarbon, and fluorocarbon fluids have been studied as a function of temperature on a stationary phase consisting of a 5% (m/m) coating of a low-molecular-mass polymer of hexafluoropropyl...

  19. Acquisition system environmental effects study. [for capillary-screen propellant retention devices

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The effects of vibration, warm gas exposure, and feed system startup/shutdown fluid dynamics on capillary-screen propellant retention capabilities are quantified. The existing technology is extended to the point where quantitative conlusions in terms of design criteria may be drawn.

  20. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, Michael; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.; Platts, S.

    2014-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 30% of ISS astronauts experience more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the space flight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration space flight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during space flight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's pre-flight condition and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by ultrasound

  1. Retention in the Canadian Forces

    DTIC Science & Technology

    2007-12-14

    the reasons that contribute to their personnel and retention problems . The research will then focus on the implemented solutions that the ADF has... one place Desire to live in own home 4 Low morale in work environment Desire to stay in one place Better career prospects in civilian life To... on my career management Low morale in my work environment and impact of job demands on family/personal life A desire for more challenging work

  2. Nuclear reactor melt-retention structure to mitigate direct containment heating

    DOEpatents

    Tutu, Narinder K.; Ginsberg, Theodore; Klages, John R.

    1991-01-01

    A light water nuclear reactor melt-retention structure to mitigate the extent of direct containment heating of the reactor containment building. The structure includes a retention chamber for retaining molten core material away from the upper regions of the reactor containment building when a severe accident causes the bottom of the pressure vessel of the reactor to fail and discharge such molten material under high pressure through the reactor cavity into the retention chamber. In combination with the melt-retention chamber there is provided a passageway that includes molten core droplet deflector vanes and has gas vent means in its upper surface, which means are operable to deflect molten core droplets into the retention chamber while allowing high pressure steam and gases to be vented into the upper regions of the containment building. A plurality of platforms are mounted within the passageway and the melt-retention structure to direct the flow of molten core material and help retain it within the melt-retention chamber. In addition, ribs are mounted at spaced positions on the floor of the melt-retention chamber, and grid means are positioned at the entrance side of the retention chamber. The grid means develop gas back pressure that helps separate the molten core droplets from discharged high pressure steam and gases, thereby forcing the steam and gases to vent into the upper regions of the reactor containment building.

  3. Acute urinary retention among astronauts.

    PubMed

    Stepaniak, Philip C; Ramchandani, Suneil R; Jones, Jeffrey A

    2007-04-01

    Although acute urinary retention (AUR) is not commonly thought of as a life-threatening condition, its presentation in orbit can lead to a number of medical complications that could compromise a space mission. We report on a middle-aged astronaut who developed urinary retention during two spaceflights. On the first mission of note, the astronaut initially took standard doses of promethazine and scopolamine before launch, and developed AUR immediately after entering orbit. For the first 3 d, the astronaut underwent intermittent catheterizations with a single balloon-tipped catheter. Due to the lack of iodine solution on board and the need for the astronaut to complete certain duties without interruption, the catheter was left in place for a total of 4 d. Although the ability to void returned after day 7, a bout of AUR reemerged on day 10, 1 d before landing. On return to Earth, a cystometrogram was unremarkable. During the astronaut's next mission, AUR again recurred for the first 24 h of microgravity exposure, and the astronaut was subsequently able to void spontaneously while in space. This report details the presentation of this astronaut, the precautions that were taken for space travel subsequent to the initial episode of AUR, and the possible reasons why space travel can predispose astronauts to urinary retention while in orbit. The four major causes of AUR--obstructive, pharmacologic, psychogenic, and neurogenic-are discussed, with an emphasis on how these may have played a role in this case.

  4. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; Liu, J.; Macias, B.; Martin, D. S.; Minkoff, L.; Ploutz-Snyder, R.; Ribeiro, L. C.; Sargsyan, A.; Smith, S. M.

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  5. Strategies to improve retention in randomised trials

    PubMed Central

    Brueton, Valerie C; Tierney, Jayne; Stenning, Sally; Harding, Seeromanie; Meredith, Sarah; Nazareth, Irwin; Rait, Greta

    2013-01-01

    severe symptoms do not return questionnaires or attend a follow-up visit, this will bias the findings of the trial. Many methods are used by researchers to keep people in trials. These encourage people to send back data by questionnaire, return to a clinic or hospital for trial-related tests, or be seen by a health or community care worker. Study characteristics This review identified methods that encouraged people to stay in trials. We searched scientific databases for randomised studies (where people are allocated to one of two or more possible treatments in a random manner) or quasi-randomised studies (where allocation is not really random, e.g. based on date of birth, order in which they attended clinic) that compared methods of increasing retention in trials. We included trials of participants from any age, gender, ethnic, cultural, language and geographic groups. Key results The methods that appeared to work were offering or giving a small amount of money for return of a completed questionnaire and enclosing a small amount of money with a questionnaire with the promise of a further small amount of money for return of a filled in questionnaire. The effect of other ways to keep people in trials is still not clear and more research is needed to see if these really do work. Such methods are shorter questionnaires, sending questionnaires by recorded delivery, using a trial design where people know which treatment they will receive, sending specially designed letters with a reply self addressed stamped envelope followed by a number of reminders, offering a donation to charity or entry into a prize draw, sending a reminder to the study site about participants to follow-up, sending questionnaires close to the time the patient was last followed-up, managing peoples' follow-up, conducting follow-up by telephone and changing the order of questionnaire questions. Quality of evidence The methods that we identified were tested in trials run in many different disease areas and

  6. Computational astrophysical fluid dynamics

    NASA Technical Reports Server (NTRS)

    Norman, Michael L.; Clarke, David A.; Stone, James M.

    1991-01-01

    The field of astrophysical fluid dynamics (AFD) is described as an emerging discipline which derives historically from both the theory of stellar evolution and space plasma physics. The fundamental physical assumption behind AFD is that fluid equations of motion accurately describe the evolution of plasmas on scales that are large in comparison with particle interaction length scales. Particular attention is given to purely fluid models of large-scale astrophysical plasmas. The role of computer simulation in AFD research is also highlighted and a suite of general-purpose application codes for AFD research is discussed. The codes are called ZEUS-2D and ZEUS-3D and solve the equations of AFD in two and three dimensions, respectively, in several coordinate geometries for general initial and boundary conditions. The topics of bipolar outflows from protostars, galactic superbubbles and supershells, and extragalactic radio sources are addressed.

  7. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

  8. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

  9. Actual drawing of histological images improves knowledge retention.

    PubMed

    Balemans, Monique C M; Kooloos, Jan G M; Donders, A Rogier T; Van der Zee, Catharina E E M

    2016-01-01

    Medical students have to process a large amount of information during the first years of their study, which has to be retained over long periods of nonuse. Therefore, it would be beneficial when knowledge is gained in a way that promotes long-term retention. Paper-and-pencil drawings for the uptake of form-function relationships of basic tissues has been a teaching tool for a long time, but now seems to be redundant with virtual microscopy on computer-screens and printers everywhere. Several studies claimed that, apart from learning from pictures, actual drawing of images significantly improved knowledge retention. However, these studies applied only immediate post-tests. We investigated the effects of actual drawing of histological images, using randomized cross-over design and different retention periods. The first part of the study concerned esophageal and tracheal epithelium, with 384 medical and biomedical sciences students randomly assigned to either the drawing or the nondrawing group. For the second part of the study, concerning heart muscle cells, students from the previous drawing group were now assigned to the nondrawing group and vice versa. One, four, and six weeks after the experimental intervention, the students were given a free recall test and a questionnaire or drawing exercise, to determine the amount of knowledge retention. The data from this study showed that knowledge retention was significantly improved in the drawing groups compared with the nondrawing groups, even after four or six weeks. This suggests that actual drawing of histological images can be used as a tool to improve long-term knowledge retention.

  10. Research on Computational Fluid Dynamics and Turbulence

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Preconditioning matrices for Chebyshev derivative operators in several space dimensions; the Jacobi matrix technique in computational fluid dynamics; and Chebyshev techniques for periodic problems are discussed.

  11. Commercial Magneto-Rheological Fluid Devices

    NASA Astrophysics Data System (ADS)

    Carlson, J. D.; Catanzarite, D. M.; St. Clair, K. A.

    Controllable magnetorheological (MR) fluid devices have reached the stage where they are in commercial production. Such devices are finding application in a variety of real world situations ranging from active vibration control to aerobic exercise equipment. Examples of several, commercial MR fluid devices are described and the comparative ability of MR and ER fluids to meet the needs of practical devices is discussed.

  12. Effect of ceramic membrane channel diameter on limiting retentate protein concentration during skim milk microfiltration.

    PubMed

    Adams, Michael C; Barbano, David M

    2016-01-01

    Our objective was to determine the effect of retentate flow channel diameter (4 or 6mm) of nongraded permeability 100-nm pore size ceramic membranes operated in nonuniform transmembrane pressure mode on the limiting retentate protein concentration (LRPC) while microfiltering (MF) skim milk at a temperature of 50°C, a flux of 55 kg · m(-2) · h(-1), and an average cross-flow velocity of 7 m · s(-1). At the above conditions, the retentate true protein concentration was incrementally increased from 7 to 11.5%. When temperature, flux, and average cross-flow velocity were controlled, ceramic membrane retentate flow channel diameter did not affect the LRPC. This indicates that LRPC is not a function of the Reynolds number. Computational fluid dynamics data, which indicated that both membranes had similar radial velocity profiles within their retentate flow channels, supported this finding. Membranes with 6-mm flow channels can be operated at a lower pressure decrease from membrane inlet to membrane outlet (ΔP) or at a higher cross-flow velocity, depending on which is controlled, than membranes with 4-mm flow channels. This implies that 6-mm membranes could achieve a higher LRPC than 4-mm membranes at the same ΔP due to an increase in cross-flow velocity. In theory, the higher LRPC of the 6-mm membranes could facilitate 95% serum protein removal in 2 MF stages with diafiltration between stages if no serum protein were rejected by the membrane. At the same flux, retentate protein concentration, and average cross-flow velocity, 4-mm membranes require 21% more energy to remove a given amount of permeate than 6-mm membranes, despite the lower surface area of the 6-mm membranes. Equations to predict skim milk MF retentate viscosity as a function of protein concentration and temperature are provided. Retentate viscosity, retentate recirculation pump frequency required to maintain a given cross-flow velocity at a given retentate viscosity, and retentate protein

  13. Postoperative urinary retention in patients undergoing elective spinal surgery.

    PubMed

    Altschul, David; Kobets, Andrew; Nakhla, Jonathan; Jada, Ajit; Nasser, Rani; Kinon, Merritt D; Yassari, Reza; Houten, John

    2017-02-01

    OBJECTIVE Postoperative urinary retention (POUR) is a common problem leading to morbidity and an increased hospital stay. There are limited data regarding its baseline incidence in patients undergoing spinal surgery and the risk factors with which it may be associated. The purpose of this study was to evaluate the incidence of POUR in elective spine surgery patients and determine the factors associated with its occurrence. METHODS The authors retrospectively reviewed the records of patients who had undergone elective spine surgery and had been prospectively monitored for POUR during an 18-month period. Collected data included operative positioning, surgery duration, volume of intraoperative fluid, length of hospital stay, and patient characteristics such as age, sex, and medical comorbidities. Dialysis patients or those with complete urinary retention preoperatively were excluded from analysis. RESULTS Of the 397 patients meeting the study inclusion criteria, 35 (8.8%) developed POUR. An increased incidence of POUR was noted in those who underwent posterior lumbar surgery, those with benign prostatic hypertrophy (BPH), those with chronic constipation or prior urinary retention, and those using a patient-controlled analgesia pump postoperatively. An increased incidence of POUR was seen with a longer operative time but not with intraoperative intravenous fluid administration. A significant relationship between the female sex and POUR was noted after controlling for BPH, yet there was no association between POUR and diabetes or intraoperative instrumentation. Postoperative retention significantly prolonged the hospital stay. Three patients developed epidural hematomas necessitating operative reexploration, and while they experienced POUR, they also developed the full constellation of cauda equina syndrome. CONCLUSIONS Awareness of the risk factors for POUR may be useful in perioperative Foley catheter management and in identifying patients who need particular

  14. Fluid Mechanics

    NASA Astrophysics Data System (ADS)

    Pnueli, David; Gutfinger, Chaim

    1997-01-01

    This text is intended for the study of fluid mechanics at an intermediate level. The presentation starts with basic concepts, in order to form a sound conceptual structure that can support engineering applications and encourage further learning. The presentation is exact, incorporating both the mathematics involved and the physics needed to understand the various phenomena in fluid mechanics. Where a didactical choice must be made between the two, the physics prevails. Throughout the book the authors have tried to reach a balance between exact presentation, intuitive grasp of new ideas, and creative applications of concepts. This approach is reflected in the examples presented in the text and in the exercises given at the end of each chapter. Subjects treated are hydrostatics, viscous flow, similitude and order of magnitude, creeping flow, potential flow, boundary layer flow, turbulent flow, compressible flow, and non-Newtonian flows. This book is ideal for advanced undergraduate students in mechanical, chemical, aerospace, and civil engineering. Solutions manual available.

  15. [Fluid management: estimation of fluid status].

    PubMed

    Renner, Jochen; Broch, Ole; Bein, Berthold

    2012-07-01

    Cardiac filling pressures alone are not appropriate to estimate the effect of a volume challenge on the corresponding change in stroke volume. Dynamic variables of fluid responsiveness have been shown to discriminate with acceptable sensitivity and specificity between responders and non-responders to a volume challenge. However, several clinical confounders have been indentified which potentially influence the predictive power of these variables. Sound knowledge of these confounders and the acknowledgement that there is no unique threshold value for volume optimisation but a considerable "gray zone" is necessary to fully exploit the advantages of functional haemodynamic monitoring.

  16. Retention at Departments of Physics

    NASA Astrophysics Data System (ADS)

    Muller, Rafael; Rosa, Luis

    2013-03-01

    A thriving physics department is the end result of many actions, taken over time, that results in the development of a sense of community between the faculty and the students. As part of this sense of community, gifted students must receive special attention and innovative ideas must be incorporated to successfully accommodate the needs of these students. We have found that the best retention strategy for gifted undergraduates is the total involvement of them in undergraduate research projects and also the development of leadership in extracurricular activities within the department. A careful employment strategy is needed to secure a faculty committed to the goals of the community.

  17. Fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth E.

    1999-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  18. Effects of polymer retention on dynamics of single phase flow

    NASA Astrophysics Data System (ADS)

    Parsa, Shima; Weitz, David

    2014-11-01

    We study the effect of adsorption of polymer solution on dynamics of a single phase flow in a model porous medium. We use confocal microscopy to fully visualize the flow of fluid in 3D micromodel of porous media. Polymer flooding is known to be an effective method for enhanced oil recovery. However, the physical mechanism is not clearly understood. We study the effect of polymer retention on the dynamics of single phase flow using particle image velocimetery. The distribution of velocities in the medium changes greatly after flow of high concentrations of polymer through the medium. Comparing the magnitude of velocities before and after the polymer flow, we observe reduction of accessible pores to the fluid at similar injection rates. Independent measurement of the permeability of the medium confirms the decrease in the porosity. Measurements of the retention of polymer in porous media shows a weak dependence on the hydrodynamic radius of the polymer. In these experiments, the viscoelastic behavior of the polymer is isolated from velocity measurements.

  19. Retention modeling and method development in hydrophilic interaction chromatography.

    PubMed

    Tyteca, Eva; Périat, Aurélie; Rudaz, Serge; Desmet, Gert; Guillarme, Davy

    2014-04-11

    In the present study, the possibility of retention modeling in the HILIC mode was investigated, testing several different literature relationships over a wide range of different analytical conditions (column chemistries and mobile phase pH) and using analytes possessing diverse physico-chemical properties. Furthermore, it was investigated how the retention prediction depends on the number of isocratic or gradient trial or initial scouting runs. The most promising set of scouting runs seems to be a combination of three isocratic runs (95, 90 and 70%ACN) and one gradient run (95 to 65%ACN in 10min), as the average prediction errors were lower than using six equally spaced isocratic runs and because it is common in Method development (MD) to perform at least one scouting gradient run in the screening step to find out the best column, temperature and pH conditions. Overall, the retention predictions were much less accurate in HILIC than what is usually experienced in RPLC. This has severe implications for MD, as it restricts the use of commercial software packages that require the simulation of the retention of every peak in the chromatogram. To overcome this problem, the recently proposed predictive elution window shifting and stretching (PEWS(2)) approach can be used. In this computer-assisted MD strategy, only an (approximate) prediction of the retention of the first and the last peak in the chromatogram is required to conduct a well-targeted trial-and-error search, with suggested search conditions uniformly covering the entire possible search and elution space. This strategy was used to optimize the separation of three representative pharmaceutical mixtures possessing diverse physico-chemical properties (pteridins, saccharides and cocktail of drugs/metabolites). All problems could be successfully handled in less than 2.5h of instrument time (including equilibration).

  20. The Fluids and Combustion Facility

    NASA Technical Reports Server (NTRS)

    Kundu, Sampa

    2004-01-01

    Microgravity is an environment with very weak gravitational effects. The Fluids and Combustion Facility (FCF) on the International Space Station (ISS) will support the study of fluid physics and combustion science in a long-duration microgravity environment. The Fluid Combustion Facility's design will permit both independent and remote control operations from the Telescience Support Center. The crew of the International Space Station will continue to insert and remove the experiment module, store and reload removable data storage and media data tapes, and reconfigure diagnostics on either side of the optics benches. Upon completion of the Fluids Combustion Facility, about ten experiments will be conducted within a ten-year period. Several different areas of fluid physics will be studied in the Fluids Combustion Facility. These areas include complex fluids, interfacial phenomena, dynamics and instabilities, and multiphase flows and phase change. Recently, emphasis has been placed in areas that relate directly to NASA missions including life support, power, propulsion, and thermal control systems. By 2006 or 2007, a Fluids Integrated Rack (FIR) and a Combustion Integrated Rack (CIR) will be installed inside the International Space Station. The Fluids Integrated Rack will contain all the hardware and software necessary to perform experiments in fluid physics. A wide range of experiments that meet the requirements of the international space station, including research from other specialties, will be considered. Experiments will be contained in subsystems such as the international standard payload rack, the active rack isolation system, the optics bench, environmental subsystem, electrical power control unit, the gas interface subsystem, and the command and data management subsystem. In conclusion, the Fluids and Combustion Facility will allow researchers to study fluid physics and combustion science in a long-duration microgravity environment. Additional information is

  1. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  2. The Retention of Female Unrestricted Line Officers

    DTIC Science & Technology

    2005-03-01

    PS y• s’TANTIA PER SCIENTIAM NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS THE RETENTION OF FEMALE UNRESTRICTED LINE OFFICERS by Elena G...Title (Mix case letters) 5. FUNDING NUMBERS The Retention of Female Unrestricted Line Officers 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND...public release; distribution is unlimited. 13. ABSTRACT (maximum 200 words) This thesis analyzes the retention of female Naval officers, focusing on the

  3. Fission-product retention in HTGR fuels

    SciTech Connect

    Homan, F.J.; Kania, M.J.; Tiegs, T.N.

    1982-01-01

    Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed.

  4. Analytic solutions for colloid transport with time- and depth-dependent retention in porous media

    NASA Astrophysics Data System (ADS)

    Leij, Feike J.; Bradford, Scott A.; Sciortino, Antonella

    2016-12-01

    Elucidating and quantifying the transport of industrial nanoparticles (e.g. silver, carbon nanotubes, and graphene oxide) and other colloid-size particles such as viruses and bacteria is important to safeguard and manage the quality of the subsurface environment. Analytic solutions were derived for aqueous and solid phase colloid concentrations in a porous medium where colloids were subject to advective transport and reversible time and/or depth-dependent retention. Time-dependent blocking and ripening retention were described using a Langmuir-type equation with a rate coefficient that respectively decreased and increased linearly with the retained concentration. Depth-dependent retention was described using a rate coefficient that is a power-law function of distance. The stream tube modeling concept was employed to extend these analytic solutions to transport scenarios with two different partitioning processes (i.e., two types of retention sites). The sensitivity of concentrations was illustrated for the various time- and/or depth-dependent retention model parameters. The developed analytical models were subsequently used to describe breakthrough curves and, in some cases, retention profiles from several published column studies that employed nanoparticle or pathogenic microorganisms. Simulations results provided valuable insights on causes for many observed complexities associated with colloid transport and retention, including: increasing or decreasing effluent concentrations with continued colloid application, delayed breakthrough, low concentration tailing, and retention profiles that are hyper-exponential, exponential, linear, or non-monotonic with distance.

  5. Institutionalization: A Model of Retention Through Student Engagement

    NASA Astrophysics Data System (ADS)

    Davis, E. J.; Campbell, A.; Strand, D.

    2005-12-01

    Bowie State University and NASA Goddard Space Flight Center have, for the past 10 years, worked diligently together to enhance the science, mathematics, engineering and technology (SMET) domain. Efforts made because of a Model Institutions for Excellence (MIE) Award have changed the landscape of the SMET domain by increasing the retention and graduation rates, the number of students entering graduate and professional schools, and the number of students entering SMET related careers. Several initiatives - a Scholarship program, PRISEM Tutoring Center, Safenet Program, Research Emphasis, Focused Mentoring, a Summer Academy for accepted and enrolled incoming students, a Bridge Program for students needing assistance being admitted to the University, the RISE Program and the Bowie State Satellite Operations and Control Center - provides the nurturing and mentoring focus, and opportunities that have resulted in a retention rate of approximately 80%, a 40% increase in the graduation rate, and an 85% increase in the number of students interested/entering graduate school. Successes that have documented by various assessment activities have led to the institutionalization of the retention model of the MIE Initiative. It is anticipated that University-wide application of the retention model will provide the incentives necessary to obtain similar results as has the MIE Initiative.

  6. Theory for nanoparticle retention time in the helical channel of quadrupole magnetic field-flow fractionation

    NASA Astrophysics Data System (ADS)

    Williams, P. Stephen; Carpino, Francesca; Zborowski, Maciej

    2009-05-01

    Quadrupole magnetic field-flow fractionation (QMgFFF) is a separation and characterization technique for magnetic nanoparticles such as those used for cell labeling and for targeted drug therapy. A helical separation channel is used to efficiently exploit the quadrupole magnetic field. The fluid and sample components therefore have angular and longitudinal components to their motion in the thin annular space occupied by the helical channel. The retention ratio is defined as the ratio of the times for non-retained and a retained material to pass through the channel. Equations are derived for the respective angular and longitudinal components to retention ratio.

  7. Sever's Disease

    MedlinePlus

    ... good flexibility while your child is growing. The stretching exercises pictured in the treatment section can lower ... your child has already recovered from Sever's disease, stretching and putting ice on the heel after activity ...

  8. Drilling fluid

    SciTech Connect

    Russell, J.A.; Patel, B.B.

    1987-11-03

    A drilling fluid additive mixture is described consisting essentially of a sulfoalkylated tannin in admixture with a non-sulfoalkylated alkali-solubilized lignite wherein the weight ratio of the sulfoalkylated tannin to the non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1. The sulfoalkylated tannin has been sulfoalkylated with at least one -(C(R-)/sub 2/-SO/sub 3/M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.

  9. Managing patients with acute urinary retention.

    PubMed

    Kuppusamy, Shanggar; Gillatt, David

    2011-04-01

    Acute urinary retention (AUR) is more than ten times more common in men than women. In men it tends to occur in the elderly; the risk of AUR is higher in men > 70 years. The causes in men can be divided into precipitated or occurring spontaneously. These can be further divided according to the mechanism i.e. obstructive, neurological and myogenic. Spontaneous AUR, caused by progression of BPH leading to a mechanical obstruction of the bladder outlet, is the most common cause of AUR. The typical presentation of AUR is a patient complaining of a sudden inability to urinate associated with progressive abdominal distension which is usually painful. The pain increases in intensity with increasing distension of the bladder. An abdominal examination should reveal a distended bladder which can be confirmed by a dull percussion note. A digital rectal examination is vital to gain information on prostatic enlargement (benign or malignant), faecal load in rectum, anal tone and presence of other masses. Urinalysis and culture should be carried out on a sample obtained after catheterisation to rule out infection. Renal function should be assessed to see if there has been damage to the upper tracts. It is better not to perform a PSA test in this situation as it will invariably be raised due to distension of the bladder and catheter insertion. If catheter insertion fails then a urological consultation is required for insertion of a suprapubic catheter. Admission is essential if the patient is: unwell with urosepsis; has abnormal renal function needing investigation and fluid monitoring; has acute neurological problems; or cannot take care of the catheter. Trial without catheter needs to be planned and the ideal time to do this is within 2-3 days so that the patient can pass urine naturally.

  10. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  11. Coupled factors influencing the transport and retention of Cryptosporidium parvum oocysts in saturated porous media.

    PubMed

    Kim, Hyunjung N; Walker, Sharon L; Bradford, Scott A

    2010-02-01

    The coupled role of solution ionic strength (IS), hydrodynamic force, and pore structure on the transport and retention of viable Cryptosporidium parvum oocyst was investigated via batch, packed-bed column, and micromodel systems. The experiments were conducted over a wide range of IS (0.1-100 mM), at two Darcy velocities (0.2 and 0.5 cm/min), and in two sands (median diameters of 275 and 710 microm). Overall, the results suggested that oocyst retention was a complex process that was very sensitive to the solution IS, the Darcy velocity, and the grain size. Increasing IS led to enhanced retention of oocysts in the column, which is qualitatively consistent with predictions of Derjaguin-Landau-Verwey-Overbeek theory. Conversely, increasing velocity and grain size resulted in less retention of oocysts in the column due to the difference in the fluid drag force and the rates of mass transfer from the liquid to the solid phase and from high to low velocity regions. Oocyst retention was controlled by a combined role of low velocity regions, weak attractive interactions, and/or steric repulsion. The contribution of each mechanism highly depended on the solution IS. In particular, micromodel observations indicated that enhanced oocyst retention occurred in low velocity regions near grain-grain contacts under highly unfavorable conditions (IS=0.1 mM). Oocyst retention was also found to be influenced by weak attractive interactions (induced by the secondary energy minimum, surface roughness, and/or nanoscale chemical heterogeneity) when the IS=1 mM. Reversible retention of oocysts to the sand in batch and column studies under favorable attachment conditions (IS=100 mM) was attributed to steric repulsion between the oocysts and the sand surface due to the presence of oocyst surface macromolecules. Comparison of experimental observations and theoretical predictions from classic filtration theory further supported the presence of this weak interaction due to steric repulsion.

  12. Urinary retention and syndrome of inappropriate antidiuretic hormone secretion (SIADH) secondary to impacted gravid uterus.

    PubMed

    Irani, M; Fisher, N; Mor, A; Bensinger, G

    2016-06-01

    Urinary retention is an emergency that rarely occurs during pregnancy. Previous case reports have suggested multiple risk factors that can cause the gravid uterus to become impacted in the pelvis leading to lower bladder or urethral compression with subsequent urinary retention. However, no cases of urinary obstruction in a pregnancy that was complicated with severe electrolyte imbalance have been reported. To our knowledge, we report the first case of a 31-year-old woman presenting at 8 weeks' gestation with acute urinary retention caused by a retroflexed, retroverted uterus with a 6-cm posterior uterine fibroid leading to syndrome of inappropriate antidiuretic hormone secretion and severe hyponatremia requiring intensive care unit admission. The cornerstones of effective management of urinary retention should include: (i) urgent bladder catheterization; (ii) assessment of sodium levels to rule out syndrome of inappropriate antidiuretic hormone secretion, and prompt treatment before neurological damage occurs; (iii) reduction of the impacted uterus; and (iv) monitoring for post-obstructive diuresis.

  13. Preheating temperature effect on tritium retention in VPS-W

    SciTech Connect

    Sato, M.; Uchimura, H.; Toda, K.; Oya, Y.; Okuno, K.; Tokunaga, T.; Watanabe, H.; Yoshida, N.; Hatano, Y.; Kasada, R.; Kimura, A.; Nagasaka, T.

    2015-03-15

    The W coating by Vacuum Plasma Spraying (VPS) technology is thought to be reasonable for most plasma facing components in future fusion reactors. In this paper the deuterium retention behavior for the Vacuum Plasma Spraying (VPS) tungsten (W) coating has been studied to demonstrate the tritium retention as a function of heating temperature. It has been found that two major deuterium desorption stages were observed at the temperature regions of 400 - 700 K (Stage 1) and 900 - 1100 K (Stage 2), considering that Stage 1 has been linked to the desorption of deuterium trapped by near surface and intrinsic defects, and Stage 2 has been related to the desorption of deuterium bound to impurities as C-D bonds. By heating the sample above 673 K, the major peak of C-1s shifted from C-O bond to C-C bond, where the retention of deuterium as Stage 2 has increased. Therefore it indicates that the hydrogen isotope retention was controlled by the amount of C-C bond in VPS, most of which was contaminated during the VPS coating process. The comparison of several samples (VPS-W with shading, VPS-W without shading and Polycrystalline W (PCW)) shows that the carbon impurity has a large affinity with deuterium and makes stable trapping states compared to that with intrinsic defects and grain boundaries. However, most of them was reduced by heating at 1173 K. Therefore, heating treatment is quite important to get rid of carbon impurities and refrain higher tritium retention in VPS. (authors)

  14. 12 CFR 226.25 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Record retention. 226.25 Section 226.25 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRUTH IN LENDING (REGULATION Z) Miscellaneous § 226.25 Record retention. (a) General rule. A creditor...

  15. 10 CFR 37.103 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Record retention. 37.103 Section 37.103 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL PROTECTION OF CATEGORY 1 AND CATEGORY 2 QUANTITIES OF RADIOACTIVE MATERIAL Records § 37.103 Record retention. Licensees shall maintain the records that are required by...

  16. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  17. Measuring Up: Benchmarking Graduate Retention. IES Report.

    ERIC Educational Resources Information Center

    Tyers, C.; Perryman, S.; Barber, L.

    Retention of college graduates by employers across the United Kingdom was examined. Data were collected through a survey of 362 organizations and interviews with 36 employers and their graduate employees. Most employers were unworried by their levels of graduate retention; two-thirds expected to keep new recruits for the foreseeable future. Rates…

  18. Novel Word Retention in Sequential Bilingual Children

    ERIC Educational Resources Information Center

    Kan, Pui Fong

    2014-01-01

    Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after…

  19. 76 FR 34010 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ...-AA43 DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 24 CFR Part 267 RIN 2501-AD53 Credit Risk Retention... a joint notice of proposed rulemaking for public comment to implement the credit risk retention... Reform and Consumer Protection Act (``Credit Risk NPR'' or ``proposed rule''). Due to the complexity...

  20. The Grade Retention/Social Promotion Debate.

    ERIC Educational Resources Information Center

    Lindelow, John

    1985-01-01

    This publication focuses on the retention/promotion debate regarding failing and low-achieving students. An introductory essay describes the inherent limitation in the research done on this issue--the impossibility of obtaining an appropriate control group--and suggests that the retention/promotion quandary can best be resolved by accommodating…

  1. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  2. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  3. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  4. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  5. Effective Teacher Retention Bonuses: Evidence From Tennessee

    ERIC Educational Resources Information Center

    Springer, Matthew G.; Swain, Walker A.; Rodriguez, Luis A.

    2016-01-01

    We report findings from a quasi-experimental evaluation of the recently implemented US$5,000 retention bonus program for effective teachers in Tennessee's Priority Schools. We estimate the impact of the program on teacher retention using a fuzzy regression discontinuity design by exploiting a discontinuity in the probability of treatment…

  6. Profile in Action: Linking Admission and Retention

    ERIC Educational Resources Information Center

    Cortes, Carla M.

    2013-01-01

    A profile-oriented retention strategy embraces the admission process as a powerful lever in improving retention and completion rates and recognizes that the student profile can be shaped by changes in admission policies or priorities--even within the current market position of the institution. In addition, the student body can be oriented toward…

  7. Emotional Intelligence and Nursing Student Retention

    ERIC Educational Resources Information Center

    Wilson, Victoria Jane

    2013-01-01

    The study examined the constructs of a Multi-Intelligence Model of Retention with four constructs: cognitive and emotional-social intelligence, student characteristics, and environmental factors. Data were obtained from sophomore students entering two diploma, nine associate, and five baccalaureate nursing programs. One year later, retention and…

  8. Faculty Personality: A Factor of Student Retention

    ERIC Educational Resources Information Center

    Shaw, Cassandra S.; Wu, Xiaodong; Irwin, Kathleen C.; Patrizi, L. A. Chad

    2016-01-01

    The purpose of this study was to determine the relationship between student retention and faculty personality as it was hypothesized that faculty personality has an effect on student retention. The methodology adopted for this study was quantitative and in two parts 1) using linear regression models to examine the impact or causality of faculty…

  9. Managing human resources to improve employee retention.

    PubMed

    Arnold, Edwin

    2005-01-01

    Managers face increased challenges as the demand for health care services increases while the supply of employees with the requisite skills continues to lag. Employee retention will become more important in the effort to service health care needs. Appropriate human resource management strategies and policies implemented effectively can significantly assist managers in dealing with the employee retention challenges ahead.

  10. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 354.73 Retention labels. An inspector may use such labels, devices, and methods as may be approved...

  11. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 354.73 Retention labels. An inspector may use such labels, devices, and methods as may be approved...

  12. Retention of New Teachers in California

    ERIC Educational Resources Information Center

    Reed, Deborah; Rueben, Kim S.; Barbour, Elisa

    2006-01-01

    In the continuing effort to raise the academic performance of public schools, improving teacher retention could be an important strategy for California. Keeping new teachers in the classroom could improve academic performance, because experienced teachers are, on average, more effective at raising student test scores. Better retention of teachers…

  13. Minority Teacher Recruitment and Retention Strategies

    ERIC Educational Resources Information Center

    Kearney-Gissendaner, Janet E.

    2010-01-01

    The tools and resources in this book help school leaders seamlessly incorporate minority teacher recruitment and retention programs into current human-resources activities. With details about exemplary minority teacher recruitment and retention programs, this book also showcases strategies for how to replicate such programs in your own school or…

  14. Using Enrollment Data to Predict Retention Rate

    ERIC Educational Resources Information Center

    Bingham, Melissa A.; Solverson, Natalie Walleser

    2016-01-01

    First- to second-year retention rates are one metric reported by colleges and universities to convey institutional success to a variety of external constituents. But how much of a retention rate is institutional inputs, and how much can be understood by examining student inputs? The authors utilize multi-year, multi-institutional data to examine…

  15. 5 CFR 9901.356 - Pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... retention. (b) Pay retention will be based on the employee's rate of base salary in effect immediately... under NSPS for the area, location, occupational group, or other class of positions involved; (ii) The remoteness of the area or location involved; (iii) The undesirability of the working conditions or the...

  16. 7 CFR 4280.136 - Minimum retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Minimum retention. 4280.136 Section 4280.136 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.136 Minimum retention. Minimum...

  17. [Nutritional physiology effect of dietary fats in the diet of growing pigs. 1. Effect of an isocaloric exchange of carbohydrate energy compared with fat energy on protein retention, in vitro synthesis of fat from glucose and on several blood parameters in piglets].

    PubMed

    Berschauer, F; Ehrensvärd, U; Gaus, G; Menke, K H

    1983-09-01

    Three groups of male, castrated piglets of the German Landrace breed, weight range 3-30 kg, were used to study the relation between fattening performance and blood parameters when feeding rations containing different amounts of fat. The fat content of the rations was either 5% (group I), 18% (group II) or 35% (group III). Concomitantly with the increased metabolizable energy (ME) content of the ration the content of digestible protein (DP) was increased and the amount of feed reduced in order to guarantee an equal intake of ME and DP in all three groups. The digestibility of the crude nutrients and protein retention of the subjects were determined in nine subsequent trials each lasting 7 days. At a body weight of 27 kg the blood concentrations of insulin, glucose, free fatty acids, neutral lipids and cholesterol were determined at different times after feeding. In addition, an oral glucose tolerance test was made and the in-vitro synthesis of fat from glucose was measured. The apparent digestibility of fat amounted, unexpectedly, to approximately 94% on the high rat rations II and III. In all groups a significant positive relation between body weight and digestibility of the fat was determined. Despite equal daily intakes of ME in all groups, in group III daily weight gain and protein retention were 7% (p less than 0.01) and 4% (p less than 0.01) higher than in group I, respectively. Blood urea levels of group III were 67% (p less than 0.01) lower than in group I. The mean daily nitrogen retention of the three groups rose gradually from 4 g at a body weight of 5 kg to 16-17 g at a body weight of 25 kg. The feed conversion of group I was lower by 22 and 36% as compared to groups II and III, respectively. Highly significant differences were observed among either groups (p less than 0.01). It has been calculated that in group III the consumption of ME/kg weight gain was about 8% (p less than 0.05) lower than in the two other groups. According to the increased fat

  18. Supercritical fluids cleaning

    SciTech Connect

    Butner, S.; Hjeresen, D.; Silva, L.; Spall, D.; Stephenson, R.

    1991-01-01

    This paper discusses a proposed multi-party research and development program which seeks to develop supercritical fluid cleaning technology as an alternative to existing solvent cleaning applications. While SCF extraction technology has been in commercial use for several years, the use of these fluids as cleaning agents poses several new technical challenges. Problems inherent in the commercialization of SCF technology include: the cleaning efficacy and compatibility of supercritical working fluids with the parts to be cleaned must be assessed for a variety of materials and components; process parameters and equipment design Have been optimized for extractive applications and must be reconsidered for application to cleaning; and co-solvents and entrainers must be identified to facilitate the removal of polar inorganic and organic contaminants, which are often not well solvated in supercritical systems. The proposed research and development program would address these issues and lead to the development and commercialization of viable SCF-based technology for precision cleaning applications. This paper provides the technical background, program scope, and delineates the responsibilities of each principal participant in the program.

  19. Determination of thermodynamic properties by supercritical fluid chromatography.

    PubMed

    Roth, Michal

    2004-05-28

    This survey attempts to summarise thermodynamic applications of supercritical fluid chromatography (SFC) with an emphasis on the results published during the last 10 years. In addition to a review of thermodynamic measurements by SFC, it contains brief sections on instrumental considerations and on the sources of auxiliary information needed when processing the retention data.

  20. Retention modelling in hydrophilic interaction chromatography.

    PubMed

    Euerby, Melvin R; Hulse, Jennifer; Petersson, Patrik; Vazhentsev, Andrey; Kassam, Karim

    2015-12-01

    The retention behaviour of acidic, basic and quaternary ammonium salts and polar neutral analytes has been evaluated on acidic, basic and neutral hydrophilic interaction chromatography (HILIC) stationary phases as a function of HILIC operating parameters such as MeCN content, buffer concentration, pH and temperature. Numerous empirical HILIC retention models (existing and newly developed ones) have been assessed for their ability to describe retention as a function of the HILIC operating parameters investigated. Retention models have been incorporated into a commercially available retention modelling programme (i.e. ACD/LC simulator) and their accuracy of retention prediction assessed. The applicability of HILIC modelling using these equations has been demonstrated in the two-dimensional isocratic (i.e. buffer concentration versus MeCN content modelling) and one-dimensional gradient separations for a range of analytes of differing physico-chemical properties on the three stationary phases. The accuracy of retention and peak width prediction was observed to be comparable to that reported in reversed-phase chromatography (RPC) retention modelling. Intriguingly, our results have confirmed that the use of gradient modelling to predict HILIC isocratic conditions and vice versa is not reliable. A relative ranking of the importance of the retention and selectivity of HILIC operating parameters has been determined using statistical approaches. For retention, the order of importance was observed to be organic content > stationary phase > temperature ≈ mobile phase pH (i.e. pH 3-6 which mainly effects the ionization of the analyte) ≈ buffer concentration. For selectivity, the nature of the stationary phase > mobile phase pH > buffer concentration > temperature > organic content.

  1. Canonical fluid thermodynamics

    NASA Technical Reports Server (NTRS)

    Schmid, L. A.

    1972-01-01

    The space-time integral of the thermodynamic pressure plays the role of the thermodynamic potential for compressible, adiabatic flow in the sense that the pressure integral for stable flow is less than for all slightly different flows. This stability criterion can be converted into a variational minimum principle by requiring the molar free-enthalpy and the temperature, which are the arguments of the pressure function, to be generalized velocities, that is, the proper-time derivatives of scalar spare-time functions which are generalized coordinates in the canonical formalism. In a fluid context, proper-time differentiation must be expressed in terms of three independent quantities that specify the fluid velocity. This can be done in several ways, all of which lead to different variants (canonical transformations) of the same constraint-free action integral whose Euler-Lagrange equations are just the well-known equations of motion for adiabatic compressible flow.

  2. Salinity of oceanic hydrothermal fluids: a fluid inclusion study

    NASA Astrophysics Data System (ADS)

    Nehlig, Pierre

    1991-03-01

    An extensive microthermometric study of quartz, epidote, plagioclase, anhydrite and sphalerite-hosted fluid inclusions from ophiolitic [Semail (Oman) and Trinity (California) ophiolites] and oceanic (East Pacific Rise hydrothermal vents, Gorringe Bank, ODP Leg 111 Hole 504B) crust has been carried out in order to constrain a model accounting for wide salinity variations measured in the oceanic hydrothermal fluids. Recorded salinities in fluid inclusions vary between 0.3 and 52 wt% NaCl eq. However, more than 60% of the mean (± standard deviation) salinities of the samples are within the range 3.2 ± 0.3wt% NaCl eq (= microthermometric error) and the mean salinity of all fluid inclusions (without the brines) is 4.0 wt% NaCl eq with a standard deviation of 1.6 wt% NaCl eq. Whereas most samples display slightly higher salinities than seawater, several samples exhibit very high salinities (more than two times that of seawater). These high salinities are restricted to the plagiogranites (Semail and Trinity ophiolites) which mark the top of the fossil magma chamber, in the transition zone between the plutonic sequence and the sheeted dyke complex. The fluid inclusion population studied in the plagiogranites is characterized by the occurrence of four major fluid inclusion families: (1) low- to medium-salinity Liquid/Vapor fluid inclusions which homogenize into the liquid phase; (2) low-salinity Liquid/Vapor fluid inclusions with pseudocritical homogenization; (3) low- to medium-salinity Liquid/Vapor fluid inclusions which homogenize into the vapor phase; and (4) high-salinity Liquid/Vapor/Halite fluid inclusions which homogenize into the liquid phase by halite dissolution and exhibit salinities as high as 52 wt% NaCl eq. These fluid inclusion families are interpreted as resulting from phase separation occurring in hydrothermal or magmatic fluids within the transition zone between the hydrothermal system and the magma chamber at temperatures higher than 500°C. Very low

  3. The Use of Fluids in Sepsis

    PubMed Central

    Avila, Audrey A; Sherwin, Nomi K; Taylor, Robinson D

    2016-01-01

    Sepsis is a systemic inflammatory response to severe infection causing significant morbidity and mortality that costs the health care system $20.3 billion annually within the United States. It is well established that fluid resuscitation is a central component of sepsis management; however, to date there is no consensus as to the ideal composition of fluid used for resuscitation. In this review, we discuss the progression of clinical research comparing various fluids, as well as the historical background behind fluid selection for volume resuscitation. We conclude that the use of balanced fluids, such as Ringer’s Lactate, seems very promising but further research is needed to confirm their role. PMID:27081589

  4. An evaluation of retention and disposal options for tritium in fuel reprocessing

    SciTech Connect

    Benjamin, R.W.; Hampson, D.C.

    1987-12-31

    This report assesses the possible options for retention of tritium and its ultimate disposal during future reprocessing of irradiated oxide fuels discharged from light water reactors (LWRs) and liquid metal fast breeder reactors (LMFBRs). The assessment includes an appraisal of the state of the retention and disposal options, an estimate of the dose commitments to the general public, an estimation of the incremental costs of the several retention and disposal options, and the potential reduction of the dose commitments resulting from retention and disposal of the tritium. The assessment is based upon an extensive study of tritium retention in reprocessing completed in 1982 by Grimes et al. Two plants were assumed, one to process LWR oxide fuel and the other to process LMFBR fuel. In each base case plant the tritium was vaporized to the atmosphere. Each of the hypothetical plants was assumed to be constructed during the 1990`s and to operate for a 20-year lifetime beginning in the year 2000 at a rate of 1,500 metric tons of heavy metal (MTHM) per 300-d year. In addition to the base case (Case 1), six other cases which included tritium retention options were examined. Although many of the features of the base-case plants remain unchanged in the tritium retention options, each case requires some additions, deletions, and modifications of portions of the plants. The retained tritium must also be managed and disposed of in a manner that is environmentally acceptable.

  5. Wildfire impacts on soil-water retention in the Colorado Front Range, United States

    USGS Publications Warehouse

    Ebel, Brian A.

    2012-01-01

    This work examined the plot-scale differences in soil-water retention caused by wildfire in the area of the 2010 Fourmile Canyon Fire in the Colorado Front Range, United States. We measured soil-water retention curves on intact cores and repacked samples, soil particle-size distributions, and organic matter content. Estimates were also made of plant-available water based on the soil-water retention curves. Parameters for use in soil-hydraulic property models were estimated; these parameters can be used in unsaturated flow modeling for comparing burned and unburned watersheds. The primary driver for measured differences in soil-water retention in burned and unburned soils was organic matter content and not soil-particle size distribution. The tendency for unburned south-facing soils to have greater organic matter content than unburned north-facing soils in this field area may explain why unburned south-facing soils had greater soil-water retention than unburned north-facing soils. Our results suggest that high-severity wildfire can “homogenize” soil-water retention across the landscape by erasing soil-water retention differences resulting from organic matter content, which for this site may be affected by slope aspect. This homogenization could have important implications for ecohydrology and plant succession/recovery in burned areas, which could be a factor in dictating the window of vulnerability of the landscape to flash floods and erosion that are a common consequence of wildfire.

  6. Transport and retention of bacteria and viruses in biochar-amended sand.

    PubMed

    Sasidharan, Salini; Torkzaban, Saeed; Bradford, Scott A; Kookana, Rai; Page, Declan; Cook, Peter G

    2016-04-01

    The transport and retention of Escherichia coli and bacteriophages (PRD1, MS2 and ФX174), as surrogates for human pathogenic bacteria and viruses, respectively, were studied in the sand that was amended with several types of biochar produced from various feedstocks. Batch and column studies were conducted to distinguish between the role of attachment and straining in microbe retention during transport. Batch experiments conducted at various solution chemistries showed negligible attachment of viruses and bacteria to biochar before or after chemical activation. At any given solution ionic strength, the attachment of viruses to sand was significantly higher than that of biochar, whereas bacteria showed no attachment to either sand or biochar. Consistent with batch results, biochar addition (10% w/w) to sand reduced virus retention in the column experiments, suggesting a potential negative impact of biochar application to soil on virus removal. In contrast, the retention of bacteria was enhanced in biochar-amended sand columns. However, elimination of the fine fraction (<60μm) of biochar particles in biochar-amended sand columns significantly reduced bacteria retention. Results from batch and column experiments suggest that land application of biochar may only play a role in microbe retention via straining, by alteration of pore size distribution, and not via attachment. Consequently, the particle size distribution of biochar and sediments is a more important factor than type of biochar in determining whether land application of biochar enhances or diminishes microbial retention.

  7. Wildfire impacts on soil-water retention in the Colorado Front Range, United States

    NASA Astrophysics Data System (ADS)

    Ebel, Brian A.

    2012-12-01

    This work examined the plot-scale differences in soil-water retention caused by wildfire in the area of the 2010 Fourmile Canyon Fire in the Colorado Front Range, United States. We measured soil-water retention curves on intact cores and repacked samples, soil particle-size distributions, and organic matter content. Estimates were also made of plant-available water based on the soil-water retention curves. Parameters for use in soil-hydraulic property models were estimated; these parameters can be used in unsaturated flow modeling for comparing burned and unburned watersheds. The primary driver for measured differences in soil-water retention in burned and unburned soils was organic matter content and not soil-particle size distribution. The tendency for unburned south-facing soils to have greater organic matter content than unburned north-facing soils in this field area may explain why unburned south-facing soils had greater soil-water retention than unburned north-facing soils. Our results suggest that high-severity wildfire can "homogenize" soil-water retention across the landscape by erasing soil-water retention differences resulting from organic matter content, which for this site may be affected by slope aspect. This homogenization could have important implications for ecohydrology and plant succession/recovery in burned areas, which could be a factor in dictating the window of vulnerability of the landscape to flash floods and erosion that are a common consequence of wildfire.

  8. [Severe asthma].

    PubMed

    González, Claudio D

    2016-01-01

    The objectives of this work were to investigate the frequency of severe asthma (SA) according to WHO definition and to compare SA patients' characteristics with those of non-severe asthma (NSA); secondly, to investigate the level of control reached throughout a period of regular treatment. Between 1-1-2005 and 12-31-2014, 471 medical records from patients with bronchial asthma assisted in Buenos Aires City were analyzed. SA frequency was 40.1% (189/471), being significantly higher among patients from the public health system (47.7%, 108/226 vs. 33%, 81/245, p = 0.001). SA patients were older than NSA ones (51.3 ± 17.4 vs. 42.6 ± 17.1 years, p = 0.000), presented longer time since onset of the disease (median 30 vs. 20 years, p = 0.000), lower educational levels (secondary level or higher 41.7% vs. 58.1%, p = 0.000), lower frequency of rhinitis (47% vs. 60.6%, p = 0.004), more severe levels of airway obstruction (FEV% 50.2 ± 13.7 vs. 77.7 ± 12.4, p = 0.000), more frequent antecedents of Near Fatal Asthma (11.1% vs. 2.8%, p = 0.000), higher levels of serum IgE (median of 410 vs. 279 UI/l, p = 0.01) and higher demand of systemic steroids requirements and hospitalizations (68.7% vs. 50.7%, p = 0.000 and 37.5% vs. 15.9%, p = 0.000, respectively). A 30.6% of SA patients (58/189) reached a follow-up period of 12 months, 13 (22.5%) of whom reached the controlled asthma level. The frequency of SA found seems to be considerable. Multicenter studies to investigate the levels of control reached by SA patients with access to proper treatment are recommended.

  9. Fractal processes in soil water retention

    SciTech Connect

    Tyler, S.W.; Wheatcraft, S.W. )

    1990-05-01

    The authors propose a physical conceptual model for soil texture and pore structure that is based on the concept of fractal geometry. The motivation for a fractal model of soil texture is that some particle size distributions in granular soils have already been shown to display self-similar scaling that is typical of fractal objects. Hence it is reasonable to expect that pore size distributions may also display fractal scaling properties. The paradigm that they used for the soil pore size distribution is the Sierpinski carpet, which is a fractal that contains self similar holes (or pores) over a wide range of scales. The authors evaluate the water retention properties of regular and random Sierpinski carpets and relate these properties directly to the Brooks and Corey (or Campbell) empirical water retention model. They relate the water retention curves directly to the fractal dimension of the Sierpinski carpet and show that the fractal dimension strongly controls the water retention properties of the Sierpinski carpet soil. Higher fractal dimensions are shown to mimic clay-type soils, with very slow dewatering characteristics and relatively low fractal dimensions are shown to mimic a sandy soil with relatively rapid dewatering characteristics. Their fractal model of soil water retention removes the empirical fitting parameters from the soil water retention models and provides paramters which are intrinsic to the nature of the fractal porous structure. The relative permeability functions of Burdine and Mualem are also shown to be fractal directly from fractal water retention results.

  10. Clay particle retention in small constructed wetlands.

    PubMed

    Braskerud, B C

    2003-09-01

    Constructed wetlands (CWs) can be used to mitigate non-point source pollution from arable fields. Previous investigations have shown that the relative soil particle retention in small CWs increases when hydraulic load increases. This paper investigates why this phenomenon occurs, even though common retention models predict the opposite, by studying clay and silt particle retention in two Norwegian CWs. Retention was measured with water flow proportional sampling systems in the inlet and outlet of the wetlands, and the texture of the suspended solids was analyzed. The surface area of the CWs was small compared to the watershed area (approximately 0.07%), giving high average hydraulic loads (1.1 and 2.0 md(-1)). One of the watersheds included only old arable land, whereas the other included areas with disturbed topsoil after artificial land leveling. Clay particle retention was 57% for the CW in the first watershed, and 22% for the CW in the disturbed watershed. The different behavior of the wetlands could be due to differences in aggregate size and stability of the particles entering the wetlands. Results showed that increased hydraulic loads did affect CW retention negatively. However, as runoff increased, soil particles/aggregates with higher sedimentation velocities entered the CWs (e.g., the clay particles behaved as silt particles). Hence, clay particle settling velocity is not constant as assumed in many prediction models. The net result was increased retention.

  11. Predictors of Calcium Retention in Adolescent Boys

    PubMed Central

    Hill, Kathleen M.; Braun, Michelle; Kern, Mark; Martin, Berdine R.; Navalta, James W.; Sedlock, Darlene A.; McCabe, Linda; McCabe, George P.; Peacock, Munro; Weaver, Connie M.

    2008-01-01

    Context: The relationship between calcium (Ca) intake and Ca retention in adolescent boys was recently reported. Objective: This study evaluated the influence of Ca intake, serum hormone levels, biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness on Ca retention in the same sample. Design: This study was a randomized, cross-over design that consisted of two 3-wk metabolic balance periods. Setting: The study took place on a university campus as a summer camp. Patients or Other Participants: A total of 31 American white boys (13–15 yr) participated in the study. Interventions: Each subject consumed a controlled diet with one of five high-low Ca intake pairs that ranged from 670-2003 mg/d, which was manipulated utilizing a fortified beverage. Main Outcome Measures: Ca retention was determined by Ca intake minus urinary and fecal Ca excretion during each balance period. Results: Ca intake explained 21.7% of the variability in Ca retention, and serum IGF-I concentration explained an additional 11.5%. Other serum hormone levels did not significantly add to the model. Biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness were not significant predictors of Ca retention in adolescent boys. Conclusions: IGF-I, a regulator of growth during puberty, is an important predictor of Ca retention in adolescent boys. However, dietary Ca intake is an even greater predictor of Ca retention during this period of growth. PMID:18840643

  12. Thermophysical Properties of Fluids and Fluid Mixtures

    SciTech Connect

    Sengers, Jan V.; Anisimov, Mikhail A.

    2004-05-03

    The major goal of the project was to study the effect of critical fluctuations on the thermophysical properties and phase behavior of fluids and fluid mixtures. Long-range fluctuations appear because of the presence of critical phase transitions. A global theory of critical fluctuations was developed and applied to represent thermodynamic properties and transport properties of molecular fluids and fluid mixtures. In the second phase of the project, the theory was extended to deal with critical fluctuations in complex fluids such as polymer solutions and electrolyte solutions. The theoretical predictions have been confirmed by computer simulations and by light-scattering experiments. Fluctuations in fluids in nonequilibrium states have also been investigated.

  13. Tritium retention in jet cryopanel samples

    SciTech Connect

    Walthers, C.R.; Jenkins, E.M. ); Mayaux, C.; Obert, W. )

    1991-01-01

    The possibility that tritium might exchange with water trapped in aluminum anodize cryopanels in JET prompted a test program at the Tritium Systems Test Assembly, TSTA, Los Alamos, New Mexico. JET furnished two test pieces of cryopanel which were exposed to tritium at approximately liquid nitrogen temperature and 25 torr pressure for nearly two weeks. One specimen was removed and the retained tritium was measured. The second specimen was subjected to several increasing temperature vacuum bakeouts and the effectiveness of the bakeouts were inferred from the pressure history of the chamber. When the retained tritium in the second specimen was measured it was found that nearly 95% of the tritium, as measured in the first specimen, had been removed during the vacuum bakeouts. If the tritium retained in the cryopanel without bakeout were scaled to JET conditions according to a linear pressure time relationship, the tritium expected to become trapped in the JET cryopanels would be approximately 0.6 gram. Testing is currently underway at TSTA which will determine the tritium retention to be expected under more realistic JET operating conditions and which will assess the effectiveness of various bake or purge schemes in removing the trapped tritium. 2 refs., 2 figs.

  14. Mechanisms affecting the transport and retention of bacteria, bacteriophage and microspheres in laboratory-scale saturated fractures

    NASA Astrophysics Data System (ADS)

    Seggewiss, G.; Dickson, S. E.

    2013-12-01

    Groundwater is becoming an increasingly important water source due to the ever-increasing demands from agricultural, residential and industrial consumers. In search of more secure sources, wells are routinely finished over large vertical depths in bedrock aquifers, creating new hydraulic pathways and thus increasing the risk of cross contamination. Moreover, hydraulic pathways are also being altered and created by increasing water withdrawal rates from these wells. Currently, it is not well understood how biological contaminants are transported through, and retained in, fractured media thereby making risk assessment and land use decisions difficult. Colloid transport within fractured rock is a complex process with several mechanisms affecting transport and retention, including: advection, hydrodynamic dispersion, diffusion, size exclusion, adsorption, and decay. Several researchers have investigated the transport of bacteria, bacteriophage, and microspheres (both carboxylated and plain) to evaluate the effects of surface properties and size on transport and retention. These studies have suggested that transport is highly dependent on the physico-chemical properties of the particle, the fracture, and the carrying fluid. However, these studies contain little detail regarding the specific mechanisms responsible for transport beyond speculating about their existence. Further, little work has been done to compare the transport of these particulate materials through the same fracture, allowing for direct observations based on particulate size and surface properties. This research examines the similarities and differences in transport and retention between four different particles through two different laboratory-scale, saturated fractures. This work is designed to explore the effects of particle size, surface properties, ionic strength of the carrying solution, and aperture field characteristics on transport and retention in single, saturated fractures. The particulates

  15. Fluid Flow Phenomena during Welding

    SciTech Connect

    Zhang, Wei

    2011-01-01

    MOLTEN WELD POOLS are dynamic. Liquid in the weld pool in acted on by several strong forces, which can result in high-velocity fluid motion. Fluid flow velocities exceeding 1 m/s (3.3 ft/s) have been observed in gas tungsten arc (GTA) welds under ordinary welding conditions, and higher velocities have been measured in submerged arc welds. Fluid flow is important because it affects weld shape and is related to the formation of a variety of weld defects. Moving liquid transports heat and often dominates heat transport in the weld pool. Because heat transport by mass flow depends on the direction and speed of fluid motion, weld pool shape can differ dramatically from that predicted by conductive heat flow. Temperature gradients are also altered by fluid flow, which can affect weld microstructure. A number of defects in GTA welds have been attributed to fluid flow or changes in fluid flow, including lack of penetration, top bead roughness, humped beads, finger penetration, and undercutting. Instabilities in the liquid film around the keyhole in electron beam and laser welds are responsible for the uneven penetration (spiking) characteristic of these types of welds.

  16. Salt and fluid balance in newborn infants.

    PubMed

    Zetterström, R

    1988-09-01

    About 5 years ago it was widely thought that preterm infants should be supplemented with extra sodium to avoid hyponatremia. It has, however, to be pointed out that VLBW infants during the first postnatal week run a risk of developing hypernatremia which makes it difficult to give general recommendations for sodium supplementation. Since the serum sodium level depends not only upon the balance between sodium intake and sodium excretion but also upon the water balance which may vary depending on the clinical condition of the baby, it seems advisable to monitor the serum sodium level in all preterm infants. Supplementation should be given in case of hyponatremia. In instances of hyponatremia it also has to be considered if the infant due to positive fluid balance has retained fluid in excess of sodium. As a general conclusion the importance of monitoring sodium balance in every preterm infant should be stressed. Disturbances are most likely to occur in VLBW infants and in infants with acute illnesses. The best way of assisting fluid balance is by repeated accurate measurements of the body weight. It should, however, be kept in ming that no reliable methods are available for the measurement of the body weight of a preterm infant who is under intensive care and who cannot be taken out of the incubator. Serum sodium levels may give information of the sodium balance but it has to be stressed that fluid and sodium balances are always interrelated and that it is desirable to have simultaneous estimations of both balances. Excess retention of fluid may be caused primarily by excess retention of sodium or by fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Magnetized drive fluids

    SciTech Connect

    Rosensweig, R.E.; Zahn, M.

    1986-04-01

    A process is described for recovering a first fluid from a porous subterranean formation which comprises injecting a displacement fluid in an effective amount to displace the first fluid, injecting a ferrofluid, applying a magnetic field containing a gradient of field intensity within the formation, driving the displacement fluid through the formation with the ferrofluid and recovering first fluid.

  18. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  19. Influence of Two-Phase Thermocapillary Flow on Cryogenic Liquid Retention in Microscopic Pores

    NASA Technical Reports Server (NTRS)

    Schmidt, G. R.; Nadarajah, A.; Chung, T. J.; Karr, G. R.

    1994-01-01

    Previous experiments indicate that the bubble point pressure of spacecraft liquid hydrogen acquisition devices is reduced substantially when the ullage is pressurized with heated hydrogen vapor. The objective is to determine whether the two-phase thermocapillary convection arising from thermodynamic non-equilibrium along the porous surfaces of such devices could lead to this observed degradation in retention performance. We also examine why retention capability appears to be unaffected by pressurization with heated helium or direct heating through the porous structure. Computational assessments based on coupled solution of the flowfield and liquid free surface indicate that for highly wetting fluids in small pores, dynamic pressure and vapor recoil dictate surface morphology and drive meniscus deformation. With superheating, the two terms exert the same influence on curvature and promote mechanical equilibrium, but with subcooling, the pressure distribution produces a suction about the pore center-line that degrades retention. This result points to thermocapillary-induced deformation arising from condensation as the cause for retention loss. It also indicates that increasing the level of non-equilibrium by reducing accommodation coefficient restricts deformation and explains why retention failure does not occur with direct screen heating or helium pressurization.

  20. Soil water retention dynamics in Luvisols at contrasting slope positions in lysimeter monoliths from an eroded soil landscape

    NASA Astrophysics Data System (ADS)

    Herbrich, Marcus; Gerke, Horst H.; Sommer, Michael

    2015-04-01

    Modeling water flow and solute transport in variably saturated soils requires the proper description of the soil water retention curve. The problem is that under field conditions, water retention may be hysteretic or otherwise changing in time due to changing soil properties. In arable soil landscapes, these changes may depend on the erosion history which created spatial patterns of soil properties such as texture and organic matter content and differences in crop development. The objective of this study was to analyze the dynamics in field-measured water retention data for Luvisols in 10 cm, 30 cm and 50 cm soil depth (Ap, E, and Bt horizons) at two contrasting at slope positions characterized by different degrees of soil erosion under intensive agricultural cultivation. Drying and wetting water retention was obtained from tensiometer/MPS and TDR data in depths representing same soil horizons. For comparison, we used drying retention data obtained from soil cores using the evaporation method (Hyprop). Drying data were fitted to the unconstrained water retention function proposed by van Genuchten (1980) and the bimodal model of Durner (1994). For wetting data, hydraulic model parameters were determined by using the Pedroso-Williams model (2010). The water contents of wetting and drying branches were dynamically changing. These changes in water retention were different for several horizons of the more eroded Luvisol as compared to the less eroded one. Differences in water retention dynamics could be related to soil tillage and the erosion history at the different slope positions. The water differences in retention could be explained by hysteresis and temporal changes in soil water repellency. Field and lab retention data differed as reported earlier. The results suggest that estimation of soil water retention curves without resorting to time-consuming field measurements remains challenging. The results suggest that for erosion-affected arable soils of the hummocky

  1. Retention of web tags and plasticine-filled leg bands applied to day-old ducklings

    USGS Publications Warehouse

    Blums, P.; Mednis, A.; Nichols, J.D.

    1994-01-01

    A new plasticine-filled leg band was developed for use in banding dayold ducklings. These bands permit inference about early survival that is not possible from banding of older young in standard operations. Two double-marking experiments with web tags and the new leg bands indicated a high retention rate for the leg bands. In contrast, several web tags were lost, permitting an analysis directed at sources of variation in web tag retention rates. We found retention rates of web tags to be higher for diving ducks (Aythya) than for dabbling ducks (Anas), and higher for tags placed the web interior than for those applied to the web edge. However, we recommend that the new plasticine-filled leg bands be used in place of web tags because of their higher retention rates and presumably greater visibility to hunters. We believe they offer great potential for new studies of duckling survival and distribution.

  2. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  3. The mixing of fluids

    SciTech Connect

    Ottino, J.M.

    1989-01-01

    What do the eruption of Krakatau, the manufacture of puff pastry and the brightness of stars have in common Each involves some aspect of mixing. Mixing also plays a critical role in modern technology. Chemical engineers rely on mixing to ensure that substances react properly, to produce polymer blends that exhibit unique properties and to disperse drag-reducing agents in pipelines. Yet in spite of its of its ubiquity in nature and industry, mixing is only imperfectly under-stood. Indeed, investigators cannot even settle on a common terminology: mixing is often referred to as stirring by oceanographers and geophysicists, as blending by polymer engineers and as agitation by process engineers. Regardless of what the process is called, there is little doubt that it is exceedingly complex and is found in a great variety of systems. In constructing a theory of fluid mixing, for example, one has to take into account fluids that can be miscible or partially miscible and reactive or inert, and flows that are slow and orderly or very fast and turbulent. It is therefore not surprising that no single theory can explain all aspect of mixing in fluids and that straightforward computations usually fail to capture all the important details. Still, both physical experiments and computer simulations can provide insight into the mixing process. Over the past several years the authors and his colleague have taken both approaches in an effort to increase understanding of various aspect of the process-particularly of mixing involving slow flows and viscous fluids such as oils.

  4. Escitalopram-associated acute urinary retention.

    PubMed

    Trombetta, Dominick; Garrett, Kathleen; Harrison, Marissa

    2013-10-01

    New-onset urinary retention can typically be explained by the use of the routine normally suspected medications (e.g., anticholinergics, antihistamines). However, selective serotonin-reuptake inhibitors are not typically presumed as the cause of acute urinary retention (AUR). The following case describes the introduction of escitalopram in a patient and the subsequent development of AUR. Medical causes of urinary retention had been ruled out, and ipratropium was initially suspected to be the cause of urinary difficulties and was discontinued. However, the retention persisted four days after suspending the ipratropium. Normal micturition resumed only after stopping the escitalopram without further need for catheterization. Escitalopram may cause rare cases of AUR and may often times be overlooked possibly because of the paucity of reporting.

  5. Taking a Holistic Approach to Retention.

    ERIC Educational Resources Information Center

    Fields, Cheryl D.

    2002-01-01

    Describes how, at the University of Kansas, many students of color are excelling at a rate that has outpaced their peers. Campus officials credit the HAWK Link program and its comprehensive approach to retention. (EV)

  6. Magnetic denture retention systems: inexpensive and efficient.

    PubMed

    Gillings, B R

    1984-09-01

    A magnetic retention system has been used in more than 6000 complete and partial overdentures, sectional dentures and implant overdentures, with excellent clinical results and patient acceptability. For the overdenture application, decoronated, root-treated teeth are fitted with preformed or cast magnetisable alloy root elements, or 'keepers'. Following conventional denture construction, paired cobalt/samarium magnets in a special configuration are cured into the denture base so that with the denture inserted, the magnets grip the root elements with a retentive force of approximately 300 g per root. The paired magnet arrangement eliminates any external magnetic field and doubles the available retention. Magnetic retention has few of the problems encountered with other retention devices. It offers simplicity, low cost, self-adjustment, inherent stress-breaking, automatic repositioning after denture displacement, comparative freedom of lateral denture movement, reduces trauma to retained roots and eliminates the need for adjustment in service. For the sectional denture application, undesirable undercuts on the abutment teeth are used to provide passive, positive retention. The separate buccal and lingual sections are joined together by parallel pins fitting into matching tubes, assembly being maintained by magnetic attraction between a retention element in one section and a keeper in the other. Insertion and removal are more difficult than with a conventional denture but soft tissue coverage is minimal. There are no visible retainer arms and food traps are eliminated. Abutment tooth preparation is negligible, the laboratory procedures simple, and the treatment inexpensive and reversible. A clinical trial of magnetic overdenture retention in conjunction with osseointegrated titanium implants is now in progress. After 21 months acceptable clinical results have been obtained. An improved implant with an alumina core and a sintered hydroxyapatite coating is at present

  7. Relationship between initial crowding and interproximal force during retention phase.

    PubMed

    Okazaki, Kumiko

    2010-06-01

    This study investigated the change in interproximal force (IPF) in mandibular anterior teeth during retention and the relationship between the irregularity index before orthodontic treatment and the IPF. The effect that an erupting third molar had on IPF was also examined. Forty treated patients (40 with extraction of four bicuspids) were followed for 18 months during the retention phase. The irregularity index was determined from initial plaster casts. The total IPF was determined by measuring the interdental frictional forces at the mandibular anterior teeth by withdrawing a metal strip. The total IPF increased during the retention phase until 18 months, and there was a positive correlation between the irregularity index and total IPF 6 to 18 months after active treatment. An erupting third molar did not affect the total IPF. An increase in the total IPF may be an indication of relapse in mandibular anterior crowding. In conclusion, orthodontists should pay special attention to potential relapse in the lower anterior teeth 6 months after active treatment in cases with severe anterior crowding before treatment.

  8. Retention behavior in tungsten and molybdenum exposed to high fluences of deuterium ions in TPE

    SciTech Connect

    J.P. Sharpe; R.D. Kolasinski; M. Shimada; P. Calderoni; R.A. Causey

    2009-06-01

    The Tritium Plasma Experiment (TPE) has been used to investigate deuterium fuel retention behavior in tungsten and molybdenum– materials utilized for plasma-facing surfaces in some existing tokamak plasma devices and under consideration for future devices. Although several studies have been performed over the past several years on these metals, many issues remain unresolved, including for example blister formation mechanisms and correlation to surface conditions. In this study we expose several metal samples to deuterium ion fluences up to 1026 ions/m2 and measure retention behavior with thermal desportion spectroscopy. Fractional retention of up to 2.0×10-5 is found for W at 600 K, and Mo similarly retains deuterium at a fraction of 1.5×10-5 at 600 K. Blistering was found for W samples exposed at temperatures above 453 K, whereas blistering was not observed for Mo samples at any experiment temperature.

  9. The role of fluids in HFSE fractionation

    NASA Astrophysics Data System (ADS)

    Rapp, Jennifer; Klemme, Stephan; Scherer, Erik

    2010-05-01

    High field strength elements are important geochemical indicators in many geological settings, in particular in subduction zones. The HFSE signature of arc magmas is depleted relative to MORB, and there is much debate about the cause of this. Interaction between crustal and mantle rocks, and fluids liberated during metamorphism are critical for the transport of elements within the Earth, and the generation of diverse geochemical signatures. Relative depletions in HFSE have been attributed to the immobility of Ti in crustal fluids, and hence the retention of Ti and HFSE in rutile within the subducted slab. A fundamental premise of most mass-flux calculations in fluid transport is that Ti is essentially immobile in these metamorphic systems due to its low solubility in fluid, coupled with strong retention in Ti-bearing minerals such as rutile, ilmenite and titanite. As a consequence, the ‘constant Ti' frame of reference is widely used with evaluation of metasomatism and open-system behaviour, supported by experiments that have demonstrated quite low Ti solubility in aqueous fluids [1-3]. We have performed novel experiments in saline fluids, which indicate that F (and Cl) greatly enhances the solubility of rutile, and hence increases the mobility of Ti. We will show that this has implications for the mobility of the other HFSE, which are strongly sequestered into Ti-phases such as rutile [4,5]. The experimental run products have been analysed using isotope dilution ICP-MS techniques [6,7] to estimate rutile/fluid partition coefficients which may be used to determine the relative mobility of HFSE in some potential metamorphic fluids. We will show that fluids may have a strong fractionating influence on the HFSE budget of metamorphic rocks, and may influence our interpretation of the global Nb/Ta budget. References [1] Antignano, A. and Manning, C.E. (2008) Chem. Geology 255 283-293 [2] Audetat, A. and Keppler, H. (2001) Earth Planet. Sci. Lett. 232 393-402 [3

  10. A Multi-Methodological Evaluation of Hispanic Student Recruitment and Retention Effectiveness at the University of Colorado, Boulder. A Qualitative Study of Recruitment and Retention by Agency.

    ERIC Educational Resources Information Center

    Jaramillo, James A.

    In order to propose solutions to expressed Hispanic minority student recruitment problems, this study assessed the strengths and weaknesses of several University of Colorado at Boulder Hispanic student recruitment agencies. Data collection involved interviews with nine minority recruiting agency representatives, two retention agency…

  11. On colloid retention in saturated porous media in the presence of energy barriers: The failure of α, and opportunities to predict η

    NASA Astrophysics Data System (ADS)

    Johnson, William P.; Tong, Meiping; Li, Xiqing

    2007-12-01

    This contribution reviews recent findings that illuminate the processes governing colloid retention in porous media under environmentally relevant conditions. In the environment, colloids act as conveyors of contaminants, or even as contaminants themselves; however, despite decades of research, we are unable to accurately predict the retention of colloids in granular aquifer media under environmental conditions, where repulsion exists between colloids and surfaces. This failure cannot be blamed solely on the complexities of the subsurface, since colloid filtration theory (CFT) works well in the absence of colloid-collector repulsion despite its idealization of porous media as consisting of spherical grains completely surrounded by fluid envelopes. Rather, the failure of CFT stems from failure to incorporate the correct mechanisms of retention when repulsion exists. Recent observations implicate wedging in grain-to-grain contacts and retention in secondary energy minima as dominant mechanisms of colloid retention in the presence of an energy barrier. Mechanistic simulations in unit cells containing grain-to-grain contacts corroborate these mechanisms of colloid retention. The resulting concept for colloid retention in the presence of an energy barrier involves translation of colloids across the collector surfaces until they become wedged within grain-to-grain contacts, or are retained via secondary energy minima (without attachment) in zones where the balance of fluid drag, diffusion, gravitational, and colloid-collector interaction forces allow retention. The above findings highlight the pore domain geometry as a dominant governor of colloid retention in so far as the geometry gives rise to grain-to-grain contacts and zones of relatively low fluid drag.

  12. Grade Retention: A Three Part Series. Policy Briefs. Grade Retention: A Flawed Education Strategy [and] Cost-Benefit Analysis of Grade Retention [and] Grade Retention: The Gap between Research and Practice

    ERIC Educational Resources Information Center

    Xia, Claire; Glennie, Elizabeth

    2005-01-01

    This document compiles a series of three policy briefs focused on the subject of grade retention. The first brief, "Grade Retention: A Flawed Education Strategy," suggests educators and policymakers caution the use of grade retention as a remedy for poor student performance. As concluded by the majority of past studies, grade retention is a failed…

  13. The effect of sitting and calf activity on leg fluid and snoring.

    PubMed

    Singh, Bhajan; Yadollahi, Azadeh; Lyons, Owen; Alshaer, Hisham; Bradley, T Douglas

    2017-02-16

    Prolonged sitting may promote leg fluid retention that redistributes to the neck during sleep and contributes to snoring. This could be attenuated by calf activity while sitting. In 16 healthy non-obese subjects we measured leg fluid volume (LFV) below the knees using bioelectrical impedance while sitting for 4h, snoring using a portable BresoDx™ device, and Mallampati grade. Using a double cross-over study design, subjects were randomized to one of two arms and crossed-over one week later: control arm - no calf exercise while sitting; intervention arm - calf contraction against a pedal resistance while sitting. The effects of sitting±calf activity on LFV and snoring were compared. We found that LFV increased by 216±101.0ml (p<0.0001) after sitting. Calf activity while sitting attenuated LFV by 53.8ml (p<0.0001) and, in all five subjects with severe upper airway narrowing (Mallampati grade IV), reduced snoring duration (from 357±132.9 to 116.2±72.1s/h, p=0.02) suggesting reduced overnight rostral fluid shift to the neck.

  14. Collaborative learning in engineering: A quest to improve student retention

    NASA Astrophysics Data System (ADS)

    Marquard, Paul J.

    Colleges of engineering are concerned with retention of their undergraduates. Several studies have determined the reasons students leave engineering to major in other disciplines. The list includes poor teaching, a difficult curriculum, and a lack of belonging. This study alters the traditional lecture format of an engineering dynamics class by using a flipped classroom where scheduled class time emphasizes a collaborative learning pedagogy. Material coverage was facilitated with online lectures. After initiating this change, student attitudes and self-efficacy were measured as well as test performance and study time.

  15. Biological effects of magnetic fluids: toxicity studies

    NASA Astrophysics Data System (ADS)

    Lacava, Z. G. M.; Azevedo, R. B.; Martins, E. V.; Lacava, L. M.; Freitas, M. L. L.; Garcia, V. A. P.; Rébula, C. A.; Lemos, A. P. C.; Sousa, M. H.; Tourinho, F. A.; Da Silva, M. F.; Morais, P. C.

    1999-07-01

    Toxicity of ionic and citrate-based magnetic fluids administrated intraperitoneally to mice was investigated through cytogenetic analysis, evaluation of mitotic index and morphological and cytometric alterations. Both magnetic fluid samples cause severe inflammatory reactions, being very toxic and thus not biocompatible. Peritoneal cells and tissues studies may provide a useful strategy to investigate the in vivo biological effects of magnetic nanoparticles.

  16. Role of fluid overpressures in crustal strength and the form of the brittle-ductile transition

    NASA Astrophysics Data System (ADS)

    Suppe, J.

    2014-12-01

    The classic crustal strength-depth model of Brace and Kolhstedt (1980) (see figure) based on experimental rock mechanics depends in the brittle regime on the critical assumption of linearly increasing hydrostatic pore-fluid pressures. This leads to a predicted linearly increasing brittle strength that is well established based on deep borehole stress measurements in crystalline crust. In contrast, fluid overpressures are widely documented in orogenic belts based on borehole data, seismic velocity analysis and analysis of veins, in some cases showing complex fault-valve pressure fluctuations between lithostatic and hydrostatic. Typical observed overpressure-depth relationships predict a brittle crustal strength that is approximately constant with depth in contrast with the classic model. This constant-strength behavior below the fluid-retention depth (ZFRD in figure) has been confirmed using deep borehole stress and fluid-pressure measurements (Suppe, 2014). Recent ductile-plastic modeling of disequilibrium compaction suggests that pressure solution promotes further increases in overpressure and weakening, promoting a very prolonged low-strength brittle-ductile transition. Overpressured conditions can be inferred to exist over a substantial fraction of crustal thickness, spanning the brittle-ductile transition, in several tectonic environments, most straightforwardly in shale-rich clastic sedimentary basins built to sea level on oceanic or highly thinned continental crust such as the US Gulf Coast and Niger Delta. These thick accumulations commonly deform into shale-rich plate boundary mountain belts (e.g. Bangladesh/Miyanmar, Makran, Trinidad/Barbados, Gulf of Alaska, southern Taiwan and New Zealand). There is deep geophysical evidence for near lithostatic pore-fluid pressures existing to depths of 20-30km based on Vp, Vs, Vp/Vs and Q observations. We present active examples from Taiwan and New Zealand, combining borehole data and seismic tomography.

  17. Colloid Transport and Retention in Fractured Media

    SciTech Connect

    McCarthy, J.F.

    2001-02-01

    The goal of this project was to identify the chemical and physical factors that control the transport of colloids in fractured materials, and develop a generalized capability to predict colloid attachment and detachment based on hydraulic factors (head, flow rate), physical processes and structure (fracture aperture, matrix porosity), and chemical properties (surface properties of colloids, solution chemistry, and mineralogy of fracture surfaces). Both aqueous chemistry and physical structure of geologic formations influenced transport. Results of studies at all spatial scales reached consensus on the importance of several key controlling variables: (1) colloid retention is dominated by chemical conditions favoring colloid-wall interactions; (2) even in the presence of conditions favorable to colloid collection, deposited colloids are remobilized over long times and this process contributes substantially to the overall extent of transport; (3) diffusive exchange between water-conducting fractures and finer fractures and pores acts to ''buffer'' the effects of the major fracture network structure, and reduces predictive uncertainties. Predictive tools were developed that account for fundamental mechanisms of colloid dynamics in fracture geometry, and linked to larger-scale processes in networks of fractures. The results of our study highlight the key role of physical and hydrologic factors, and processes of colloid remobilization that are potentially of even greater importance to colloid transport in the vadose zone than in saturated conditions. We propose that this work be extended to focus on understanding vadose zone transport processes so that they can eventually be linked to the understanding and tools developed in our previous project on transport in saturated groundwater systems.

  18. Water retention curves and thermal insulating properties of Thermosand

    NASA Astrophysics Data System (ADS)

    Leibniz, Otto; Winkler, Gerfried; Birk, Steffen

    2010-05-01

    The heat loss and the efficiency of isolating material surrounding heat supply pipes are essential issues for the energy budget of heat supply pipe lines. Until now heat loss from the pipe is minimized by enlarging the polyurethane (PU) - insulation thickness around the pipe. As a new approach to minimize the heat loss a thermally insulating bedding material was developed and investigated. Conventional bedding sands cover all necessary soil mechanical properties, but have a high thermal conductivity from λ =1,5 to 1,7 W/(m K). A newly developed embedding material 'Thermosand' shows thermal properties from λ=0,18 W/(m K) (dry) up to 0,88 W/(m K) (wet). The raw material originates from the waste rock stockpiles of a coal mine near Fohnsdorf, Austria. With high temperatures up to nearly 1000 ° C and a special mineral mixture, a natural burned reddish material resembling clinker arises. The soilmechanical properties of Thermosand has been thoroughly investigated with laboratory testing and in situ investigations to determine compaction-, permeability- and shear-behaviour, stiffness and corresponding physical parameters. Test trenches along operational heat pipes with temperature-measurement along several cross-sections were constructed to compare conventional embedding materials with 'Thermosand'. To investigate the influence of varying moisture content on thermal conductivity a 1:1 large scale model test in the laboratory to simulate real insitu-conditions was established. Based on this model it is planned to develop numerical simulations concerning varying moisture contents and unsaturated soil mechanics with heat propagation, including the drying out of the soil during heat input. These simulations require the knowledge about the water retention properties of the material. Thus, water retention curves were measured using both steady-state tension and pressure techniques and the simplified evaporation method. The steady-state method employs a tension table (sand

  19. Fluid mechanics in fluids at rest.

    PubMed

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  20. Fluid mechanics in fluids at rest

    NASA Astrophysics Data System (ADS)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity vv. The term “compressibility” as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci.10.1016/j.ijengsci.2012.01.006 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and

  1. Neonatal opaque right lung: delayed fluid resorption

    SciTech Connect

    Swischuk, L.E.; Hayden, K.; Richardson, J.

    1981-12-01

    Eight newborn infants with opaque right lungs were examined. Clinically, the main problem associated with the opaque right lung is mild respiratory distress, and radiographyically, the findings consist of (a) a totally opaque right lung, (b) a semiopaque right lung, or (c) an opaque right upper lobe only. These findings are usually interpreted as representing pneumonia, empyema, or hydrochlothorax, but the fact that they clear within 24 to 48 hours indicates that none of these diseases is the cause. It is thought that neonatal opaque right lung results from the transient retention of normal fetal fluid in the right lung.

  2. Effects of Nepeta menthoides aqueous extract on retention and retrieval of memory in mice.

    PubMed

    Sarahroodi, S; Jafari-Najafi, R; Nasri, S; Rohampour, K; Maleki-Jamshid, A; Esmaeili, S

    2012-11-15

    There are several evidences that plants and vegetables with antioxidant activity can reduce oxidative damages in brain and improve cognitive functions. The aim of this study was evaluation of Nepeta menthoides aqueous extract on memory retention and retrieval of mice by using passive avoidance apparatus. For this purpose, mice were classified, coded, weighted and grouped (n = 8) as follow as: control group (Only electric shock), blank group (electric shock plus normal saline) and test groups (electric shock plus Nepeta menthoides extract by doses: 100, 200, 400 and 800 mg kg(-1), i.p.). Delay time of leaving the platform was measured for retention and retrieval test of memory in all mentioned groups. In retention test, plant extract was administered immediately after receiving electric shock while it was administered 24 h after receiving electric shock in retrieval. The results revealed that Nepeta menthoides aqueous extract significantly (p<0.05) increased memory retention and retrieval. The best response for memory retention and retrieval was achieved with 800 mg kg(-1) of Nepeta extract. In conclusion, enhancement of memory retention and retrieval by Nepeta menthoides could be cause of antioxidant activity of its components such as rosmarinic acid, caffeic acid and phenolic acids.

  3. Mechanisms of nutrient retention and its relation to flow connectivity in river-floodplain corridors

    USGS Publications Warehouse

    Larsen, Laurel; Harvey, Judson; Maglio, Morgan M.

    2015-01-01

    Understanding heterogeneity or patchiness in the distribution of vegetation and retention of C and nutrients in river corridors is critical for setting priorities for river management and restoration. Several mechanisms of spatial differentiation in nutrient retention in river and floodplain corridors have been recognized, but few studies have distinguished their relative importance or established their role in long-term geomorphic change, nutrient retention, and connectivity with downstream systems. We evaluated the ability of 3 mechanisms (evapotranspiration focusing [EF], differential hydrologic exchange [DHE], and particulate nutrient redistribution [PNR]) to explain spatial patterns of P retention and function in the Everglades (Florida, USA). We used field measurements in sloughs and on slightly higher, more densely vegetated ridges to quantify P fluxes attributable to the 3 mechanisms. EF does not explain Everglades nutrient retention or P concentrations on ridges and in sloughs. However, DHE resulting from different periods of groundwater–surface-water connectivity across topographic elements is the primary cause of elevated P concentrations on ridges and completely explains interpatch differences in long-term P accumulation rates. With historical flow velocities, which were an order of magnitude higher than at present, PNR would have further increased the interpatch difference in long-term P retention rates nearly 2-fold. In conclusion, DHE and PNR are the dominant drivers of nutrient patchiness in the Everglades and are hypothesized to be important in P-limited river and floodplain corridors globally.

  4. Information Warfare Officer Retention: Using a Capabilities-based Assessment to Solve Retention Issues

    DTIC Science & Technology

    2009-12-01

    39 1. Web -based Surveys............................................................... 39 2. Choice-based Conjoint... CONTACT E-MAILS .......................... 179 APPENDIX E. IW RETENTION SURVEY QUESTION 3 OPTIONS..................... 183 APPENDIX F. IW RETENTION...30 Table 6. Web -Based Survey Positives and Negatives (After Denmond, Johnson, Lewis

  5. Considering Student Retention as a Complex System: A Possible Way forward for Enhancing Student Retention

    ERIC Educational Resources Information Center

    Forsman, Jonas; van den Bogaard, Maartje; Linder, Cedric; Fraser, Duncan

    2015-01-01

    This study uses multilayer minimum spanning tree analysis to develop a model for student retention from a complex system perspective, using data obtained from first-year engineering students at a large well-regarded institution in the European Union. The results show that the elements of the system of student retention are related to one another…

  6. Calculation of retention time tolerance windows with absolute confidence from shared liquid chromatographic retention data.

    PubMed

    Boswell, Paul G; Abate-Pella, Daniel; Hewitt, Joshua T

    2015-09-18

    Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user's system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called "retention projection" was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously.

  7. Nursing Student Retention in Associate Degree Nursing Programs Utilizing a Retention Specialist

    ERIC Educational Resources Information Center

    Schrum, Ronna A.

    2014-01-01

    The purpose of this study was to examine specific variables associated with nursing student retention in Associate Degree Nursing (ADN) Programs. Jeffreys (2004) Nursing Undergraduate Retention and Success (NURS) conceptual model provided the framework for this descriptive correlational study. One hundred sixty eight pre-licensure associate degree…

  8. Intracochlear drug injections through the round window membrane: Measures to improve drug retention

    PubMed Central

    Plontke, Stefan K.; Hartsock, Jared J.; Gill, Ruth M.; Salt, Alec N.

    2016-01-01

    The goal of this study was to develop appropriate methodology to apply drugs quantitatively to perilymph of the ear. Intratympanic applications of drugs to the inner ear often result in variable drug levels in perilymph and can only be used for molecules that readily permeate the round window (RW) membrane. Direct intracochlear and intralabyrinthine application procedures for drugs, genes or cell-based therapies by-pass the tight boundaries at the round window, oval window, otic capsule and the blood-labyrinth barrier. However, perforations can release inner ear pressure, allowing cerebrospinal fluid to enter through the cochlear aqueduct, displacing the injected drug solution into the middle ear. Two markers, fluorescein or fluorescein isothiocyanate (FITC)-labeled dextran, were used to quantify how much of an injected substance was retained in cochlear perilymph following an intracochlear injection. We evaluated whether procedures to mitigate fluid leaks improved marker retention in perilymph. Almost all procedures to reduce volume efflux, including the use of gel for internal sealing and glue for external sealing of the injection site, resulted in improved retention of the marker in perilymph. Adhesive on the RW membrane effectively prevented leaks but also influenced fluid exchange between CSF and perilymph. We conclude that drugs can be delivered to the ear in a consistent, quantitative manner using intracochlear injections if care is taken to control the fluid leaks that result from cochlear perforation. PMID:26905306

  9. Employee retention: a customer service approach.

    PubMed

    Gerson, Richard F

    2002-01-01

    Employee retention is a huge problem. There are staff shortages in radiology because not enough people are entering the profession; too many people are leaving the profession for retirement, higher-paying jobs or jobs with less stress; and there are not enough opportunities for career advancement. Staff shortages are exacerbated by difficulty in retaining people who enter the profession. While much work has been focused on recruitment and getting more people "in the front door," I suggest that the bulk of future efforts be focused on employee retention and "closing the back door." Employee retention must be an ongoing process, not a program. Approaches to employee retention that focus on external things, i.e., things that the company can do to or for the employee, generally are not successful. The truth is that employee retention processes must focus on what the employee gets out of the job. The process must be a benefits-based approach that helps employees answer the question, "What's in it for me?" The retention processes must be ongoing and integrated into the daily culture of the company. The best way to keep your employees is to treat them like customers. Customer service works for external customers. We treat them nicely. We work to satisfy them. We help them achieve their goals. Why not do the same for our employees? If positive customer service policies and practices can satisfy and keep external customers, why not adapt these policies and practices for employees? And, there is a service/satisfaction link between employee retention and higher levels of customer satisfaction. Customers prefer dealing with the same employees over and over again. Employee turnover destroys a customer's confidence in the company. Just like a customer does not want to have to "train and educate" a new provider, they do not want to do the same for your "revolving door" employees. So, the key is to keep employees so they in turn will help you keep your customers. Because the

  10. A systematic review of interventions to improve postpartum retention of women in PMTCT and ART care

    PubMed Central

    Geldsetzer, Pascal; Yapa, H Manisha N; Vaikath, Maria; Ogbuoji, Osondu; Fox, Matthew P; Essajee, Shaffiq M; Negussie, Eyerusalem K; Bärnighausen, Till

    2016-01-01

    Introduction The World Health Organization recommends lifelong antiretroviral therapy (ART) for all pregnant and breastfeeding women living with HIV. Effective transitioning from maternal and child health to ART services, and long-term retention in ART care postpartum is crucial to the successful implementation of lifelong ART for pregnant women. This systematic review aims to determine which interventions improve (1) retention within prevention of mother-to-child HIV transmission (PMTCT) programmes after birth, (2) transitioning from PMTCT to general ART programmes in the postpartum period, and (3) retention of postpartum women in general ART programmes. Methods We searched Medline, Embase, ISI Web of Knowledge, the regional World Health Organization databases and conference abstracts for data published between 2002 and 2015. The quality of all included studies was assessed using the GRADE criteria. Results and Discussion After screening 8324 records, we identified ten studies for inclusion in this review, all of which were from sub-Saharan Africa except for one from the United Kingdom. Two randomized trials found that phone calls and/or text messages improved early (six to ten weeks) postpartum retention in PMTCT. One cluster-randomized trial and three cohort studies found an inconsistent impact of different levels of integration between antenatal care/PMTCT and ART care on postpartum retention. The inconsistent results of the four identified studies on care integration are likely due to low study quality, and heterogeneity in intervention design and outcome measures. Several randomized trials on postpartum retention in HIV care are currently under way. Conclusions Overall, the evidence base for interventions to improve postpartum retention in HIV care is weak. Nevertheless, there is some evidence that phone-based interventions can improve retention in PMTCT in the first one to three months postpartum. PMID:27118443

  11. Theoretical prediction of multiple fluid-fluid transitions in monocomponent fluids

    NASA Astrophysics Data System (ADS)

    Cervantes, L. A.; Benavides, A. L.; del Río, F.

    2007-02-01

    The authors use the analytical equation of state obtained by the discrete perturbation theory [A. L. Benavides and A. Gil-Villegas, Mol. Phys. 97, 1225 (1999)] to study the phase diagram of fluids with discrete spherical potentials formed by a repulsive square-shoulder plus an attractive square-well interaction (SS+SW). This interaction is characterized by the usual energy and size parameters plus three dimensionless parameters: two of them measuring the widths of the SS and the SW and the third the relative height of the SS. The matter of interest is that, for certain values of the interaction parameters, the SS +SW systems exhibit more than one first-order fluid-fluid transition. The evidence that several real substances (such as water, phosphorus, carbon, and silica, among others) exhibit an extra liquid-liquid transition has drawn interest into the study of interactions responsible for this behavior. The simple SS +SW fluid is one of the systems that, in spite of being spherically symmetric, shows multiple fluid-fluid transitions. In this work the authors investigate systematically the effect on the phase diagram of varying the interaction parameters. The use of an analytical free-energy equation gives a clear thermodynamic picture of the emergence of different types of critical points, throwing new light on the phase behavior of these fluids and thus clarifying previous results obtained by other techniques. The interplay of attractive and repulsive forces with several scale lengths produces very rich phase diagrams, including cases with three critical points. The region of the interaction-parameter space where multiple critical points appear is mapped for various families of interactions.

  12. Fluid transport container

    DOEpatents

    DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.

    1995-01-01

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.

  13. Fluid transport container

    DOEpatents

    DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.

    1995-11-14

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.

  14. Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography.

    PubMed

    Jovanović, Marko; Rakić, Tijana; Jančić-Stojanović, Biljana; Ivanović, Darko; Medenica, Mirjana

    2014-07-01

    Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.

  15. The impact of immobile zones on the transport and retention of nanoparticles in porous media

    NASA Astrophysics Data System (ADS)

    Molnar, Ian L.; Gerhard, Jason I.; Willson, Clinton S.; O'Carroll, Denis M.

    2015-11-01

    Nanoparticle transport and retention within porous media is treated by conceptualizing the porous media as a series of independent collectors (e.g., Colloid Filtration Theory). This conceptualization assumes that flow phenomena near grain-grain contacts, such as immobile zones (areas of low flow), exert a negligible influence on nanoparticle transport and assumes that retention and release of particles depends only on surface chemistry. This study investigated the impact of immobile zones on nanoparticle transport and retention by employing synchrotron X-ray computed microtomography (SXCMT) to examine pore-scale silver nanoparticle distributions during transport through three sand columns: uniform iron oxide, uniform quartz, and well-graded quartz. Extended tailing was observed during the elution phase of all experiments suggesting that hydraulic retention in immobile zones, not detachment from grains, was the source of tailing. A numerical simulation of fluid flow through an SXCMT data set predicted the presence of immobile zones near grain-grain contacts. SXCMT-determined silver nanoparticle concentrations observed that significantly lower nanoparticle concentrations existed near grain-grain contacts throughout the duration of all experiments. In addition, the SXCMT-determined pore-scale concentration gradients were found to be independent of surface chemistry and grain size distribution, suggesting that immobile zones limit the diffusive transport of nanoparticles toward the collectors. These results suggest that the well-known overprediction of nanoparticle retention by traditional CFT may be due to ignoring the influences of grain-grain contacts and immobile zones. As such, accurate prediction of nanoparticle transport requires consideration of immobile zones and their influence on both hydraulic and surface retention.

  16. Effects of phytase supplementation on phosphorus retention in broilers and layers: a meta-analysis.

    PubMed

    Bougouin, A; Appuhamy, J A D R N; Kebreab, E; Dijkstra, J; Kwakkel, R P; France, J

    2014-08-01

    Phytase, a widely used feed additive in poultry diets, increases P availability and subsequently reduces inorganic-P supplementation and P-excretion. Phytase supplementation effect on P-retention in poultry has been investigated, but the effect sizes were highly variable. The present study's objective was to conduct several meta-analyses to quantitatively summarize the phytase effect on P-retention in broilers and layers. Data from 103 and 26 controlled experiments testing the phytase effect on P-retention were included in 2 separate meta-analyses for broilers and layers, respectively. The mean difference calculated by subtracting the means of P-retention for the control group from the phytase-supplemented group was chosen as an effect size estimate. Between-study variability (heterogeneity) of mean difference was estimated using random-effect models and had a significant effect (P < 0.01) in both broilers and layers. Therefore, random-effect models were extended to mixed-effect models to explain heterogeneity and obtain final phytase effect size estimates. Available dietary and bird variables were included as fixed effects in the mixed-effect models. The final broiler mixed-effect model included phytase dose and Ca-to-total-P ratio (Ca:tP), explaining 15.6% of the heterogeneity. Other variables such as breed might further explain between-study variance. Broilers consuming control diets were associated with 48.4% P-retention. Exogenous phytase supplementation at 1,039 FTU/kg of diet increased P-retention by 8.6 percentage units on average. A unit increase of phytase dose and Ca:tP from their means further increased P-retention. For layers, the final mixed-effect models included dietary Ca, age, and experimental period length. The variables explained 65.9% of the heterogeneity. Layers receiving exogenous phytase at 371 FTU/kg were associated with a 5.02 percentage unit increase in P-retention. A unit increase in dietary Ca from its mean increased P-retention

  17. Optimal design of a tuned liquid damper using a magnetic fluid with one electromagnet.

    PubMed

    Ohno, K; Shimoda, M; Sawada, T

    2008-05-21

    Characteristics of a tuned magnetic fluid damper are examined. The optimal depth of a magnetic fluid in a cylindrical container is calculated using a linear analysis of a magnetic fluid sloshing. In order to avoid swirling in lower depth fluids, several experiments using greater fluid depths are carried out and a good damping range is obtained.

  18. Factors affecting magnetic retention of particles in the upper airways: an in vitro and ex vivo study.

    PubMed

    Ally, J; Amirfazli, A; Roa, W

    2006-01-01

    This paper presents the results of experiments using an in vitro model and an ex vivo animal model (Rana catesbeiana) to study magnetic particle retention in the conducting airways, specifically the trachea and bronchi. The purpose of these experiments was to determine the significant factors for retention of magnetic particles deposited from an aerosol at the airway surface using a magnetic field. The results indicate that the apparent viscosity of the mucus layer at low shear rates is the most significant obstacle to particle retention. The results also show that particle size and aggregation play major roles in particle retention. The mucus transport rate, unlike the effect of fluid velocity in intravenous applications, did not appear to be a determining factor for particle retention. It was also found that a suitably designed magnetic system, aside from having a high intensity, needs to exert a strong radial field to promote particle aggregation. The findings suggest that one possible approach to magnetic particle retention could be delivery of a mucolytic agent along with the drug particles. This study provides the fundamentals needed for development of a targeted magnetic drug delivery system for inhaled therapeutic aerosol particles.

  19. Pulmonary instillation of low doses of titanium dioxide nanoparticles in mice leads to particle retention and gene expression changes in the absence of inflammation

    SciTech Connect

    Husain, Mainul; Saber, Anne T.; Guo, Charles; Jacobsen, Nicklas R.; Jensen, Keld A.; Yauk, Carole L.; Williams, Andrew; Vogel, Ulla; Wallin, Hakan; Halappanavar, Sabina

    2013-06-15

    We investigated gene expression, protein synthesis, and particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO{sub 2}). Female C57BL/6 mice were exposed to rutile nano-TiO{sub 2} via single intratracheal instillations of 18, 54, and 162 μg/mouse. Mice were sampled 1, 3, and 28 days post-exposure. The deposition of nano-TiO{sub 2} in the lungs was assessed using nanoscale hyperspectral microscopy. Biological responses in the pulmonary system were analyzed using DNA microarrays, pathway-specific real-time RT-PCR (qPCR), gene-specific qPCR arrays, and tissue protein ELISA. Hyperspectral mapping showed dose-dependent retention of nano-TiO{sub 2} in the lungs up to 28 days post-instillation. DNA microarray analysis revealed approximately 3000 genes that were altered across all treatment groups (± 1.3 fold; p < 0.1). Several inflammatory mediators changed in a dose- and time-dependent manner at both the mRNA and protein level. Although no influx of neutrophils was detected at the low dose, changes in the expression of several genes and proteins associated with inflammation were observed. Resolving inflammation at the medium dose, and lack of neutrophil influx in the lung fluid at the low dose, were associated with down-regulation of genes involved in ion homeostasis and muscle regulation. Our gene expression results imply that retention of nano-TiO{sub 2} in the absence of inflammation over time may potentially perturb calcium and ion homeostasis, and affect smooth muscle activities. - Highlights: • Pulmonary effects following exposure to low doses of nano-TiO{sub 2} were examined. • Particle retention in lungs was assessed using nanoscale hyperspectral microscopy. • Particles persisted up to 28 days in lungs in all dose groups. • Inflammation was the pathway affected in the high dose group at all time points. • Ion homeostasis and muscle activity pathways were affected in the low dose

  20. USAR Nurse Referral and Retention Program.

    PubMed

    Foley, J E; Foley, B J

    1992-09-01

    In 1987, the 804th Hospital Center made alleviating the shortfall of registered nurses in the Command a priority. The Command had only 79% of its registered nurse positions filled at the time. Using the recruitment strategies of an employee referral program and a mailing list, the Command reached 100% fill in 2 years and maintained those gains for an additional year. Retention strategies were also implemented which lowered the attrition rate. This paper describes the Army Nurse Referral and Retention Program developed and implemented at the 804th Hospital Center that relieved the shortfall of registered nurses in the United States Army Reserve in New England.

  1. JT8D engine performance retention

    NASA Technical Reports Server (NTRS)

    James, A. D.; Weisel, D. R.

    1981-01-01

    The attractive performance retention characteristics of the JT8D engine are described. Because of its moderate bypass ratio and turbine temperature, and stiff structural design, the performance retention versus flight cycles of the JT8D engine sets a standard that is difficult for other engines to equal. In addition, the significant benefits of refurbishment of the JT8D engine are presented. Cold section refurbishment offers thrust specific fuel consumption improvements of up to 2 percent and payback in less than a year, making a very attractive investment option for the airlines.

  2. Nitrogen Saturation in Highly Retentive Watersheds?

    NASA Astrophysics Data System (ADS)

    Daley, M. L.; McDowell, W. H.

    2009-12-01

    Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

  3. Mentoring--a staff retention tool.

    PubMed

    Kanaskie, Mary Louise

    2006-01-01

    Staff retention presents a common challenge for hospitals nationwide. Mentorship programs have been explored as one method of creating environments that promote staff retention. Successful achievement of nurse competencies identified in the Synergy Model for Patient Care can best be achieved in an environment that encourages and facilitates mentoring. Mentoring relationships in critical care provide the ongoing interactions, coaching, teaching, and role modeling to facilitate nurses' progression along this continuum. Mentoring relationships offer support and professional development for nurses at all levels within an organization as well as an optimistic outlook for the nursing profession.

  4. Sum of ranking differences to rank stationary phases used in packed column supercritical fluid chromatography.

    PubMed

    West, Caroline; Khalikova, Maria A; Lesellier, Eric; Héberger, Károly

    2015-08-28

    The identification of a suitable stationary phase in supercritical fluid chromatography (SFC) is a major source of difficulty for those with little experience in this technique. Several protocols have been suggested for column classification in high-performance liquid chromatography (HPLC), gas chromatography (GC), and SFC. However, none of the proposed classification schemes received general acceptance. A fair way to compare columns was proposed with the sum of ranking differences (SRD). In this project, we used the retention data obtained for 86 test compounds with varied polarity and structure, analyzed on 71 different stationary phases encompassing the full range in polarity of commercial packed columns currently available to the SFC chromatographer, with a single set of mobile phase and operating conditions (carbon dioxide-methanol mobile phase, 25°C, 150bar outlet pressure, 3ml/min). First, a reference column was selected and the 70 remaining columns were ranked based on this reference column and the retention data obtained on the 86 analytes. As these analytes previously served for the calculation of linear solvation energy relationships (LSER) on the 71 columns, SRD ranks were compared to LSER methodology. Finally, an external comparison based on the analysis of 10 other analytes (UV filters) related the observed selectivity to SRD ranking. Comparison of elution orders of the UV filters to the SRD rankings is highly supportive of the adequacy of SRD methodology to select similar and dissimilar columns.

  5. Postoperative fluid management

    PubMed Central

    Kayilioglu, Selami Ilgaz; Dinc, Tolga; Sozen, Isa; Bostanoglu, Akin; Cete, Mukerrem; Coskun, Faruk

    2015-01-01

    Postoperative care units are run by an anesthesiologist or a surgeon, or a team formed of both. Management of postoperative fluid therapy should be done considering both patients’ status and intraoperative events. Types of the fluids, amount of the fluid given and timing of the administration are the main topics that determine the fluid management strategy. The main goal of fluid resuscitation is to provide adequate tissue perfusion without harming the patient. The endothelial glycocalyx dysfunction and fluid shift to extracellular compartment should be considered wisely. Fluid management must be done based on patient’s body fluid status. Patients who are responsive to fluids can benefit from fluid resuscitation, whereas patients who are not fluid responsive are more likely to suffer complications of over-hydration. Therefore, common use of central venous pressure measurement, which is proved to be inefficient to predict fluid responsiveness, should be avoided. Goal directed strategy is the most rational approach to assess the patient and maintain optimum fluid balance. However, accessible and applicable monitoring tools for determining patient’s actual fluid need should be further studied and universalized. The debate around colloids and crystalloids should also be considered with goal directed therapies. Advantages and disadvantages of each solution must be evaluated with the patient’s specific condition. PMID:26261771

  6. Computational fluid dynamics modelling of hydraulics and sedimentation in process reactors during aeration tank settling.

    PubMed

    Jensen, M D; Ingildsen, P; Rasmussen, M R; Laursen, J

    2006-01-01

    Aeration tank settling is a control method allowing settling in the process tank during high hydraulic load. The control method is patented. Aeration tank settling has been applied in several waste water treatment plants using the present design of the process tanks. Some process tank designs have shown to be more effective than others. To improve the design of less effective plants, computational fluid dynamics (CFD) modelling of hydraulics and sedimentation has been applied. This paper discusses the results at one particular plant experiencing problems with partly short-circuiting of the inlet and outlet causing a disruption of the sludge blanket at the outlet and thereby reducing the retention of sludge in the process tank. The model has allowed us to establish a clear picture of the problems arising at the plant during aeration tank settling. Secondly, several process tank design changes have been suggested and tested by means of computational fluid dynamics modelling. The most promising design changes have been found and reported.

  7. Particle retention in suspension-feeding fish after removal of filtration structures.

    PubMed

    Smith, Jennifer C; Sanderson, S Laurie

    2013-12-01

    The suspension-feeding cichlids Oreochromis aureus (blue tilapia) and Oreochromis esculentus (ngege tilapia) are able to selectively retain small food particles. The gill rakers and microbranchiospines of these species have been assumed to function as filters. However, surgical removal of these oral structures, which also removed associated mucus, did not significantly affect the total number of 11-200 μm particles ingested by the fish. This result supports the hypothesis that the branchial arch surfaces themselves play an important role in crossflow filtration. Both species selectively retained microspheres greater than 50 μm with gill rakers and microbranchiospines intact as well as removed, demonstrating that neither these structures nor mucus are necessary for size selectivity to occur during biological crossflow filtration. After removal of the gill rakers and microbranchiospines, O. esculentus retained significantly more microspheres 51-70 μm in diameter and fewer 91-130 μm microspheres compared to retention with intact structures, but the particle size selectivity of O. aureus was not affected significantly. These results support conclusions from previous computational fluid dynamics simulations indicating that particle size can have marked effects on particle trajectory and retention inside the fish oropharyngeal cavity during crossflow filtration. The substantial inter-individual variability in particle retention by suspension-feeding fish is an unexplored area of research with the potential to increase our understanding of the factors influencing particle retention during biological filtration.

  8. Respiratory fluid mechanics

    NASA Astrophysics Data System (ADS)

    Grotberg, James B.

    2011-02-01

    This article covers several aspects of respiratory fluid mechanics that have been actively investigated by our group over the years. For the most part, the topics involve two-phase flows in the respiratory system with applications to normal and diseased lungs, as well as therapeutic interventions. Specifically, the topics include liquid plug flow in airways and at airway bifurcations as it relates to surfactant, drug, gene, or stem cell delivery into the lung; liquid plug rupture and its damaging effects on underlying airway epithelial cells as well as a source of crackling sounds in the lung; airway closure from "capillary-elastic instabilities," as well as nonlinear stabilization from oscillatory core flow which we call the "oscillating butter knife;" liquid film, and surfactant dynamics in an oscillating alveolus and the steady streaming, and surfactant spreading on thin viscous films including our discovery of the Grotberg-Borgas-Gaver shock.

  9. Respiratory fluid mechanics

    PubMed Central

    Grotberg, James B.

    2011-01-01

    This article covers several aspects of respiratory fluid mechanics that have been actively investigated by our group over the years. For the most part, the topics involve two-phase flows in the respiratory system with applications to normal and diseased lungs, as well as therapeutic interventions. Specifically, the topics include liquid plug flow in airways and at airway bifurcations as it relates to surfactant, drug, gene, or stem cell delivery into the lung; liquid plug rupture and its damaging effects on underlying airway epithelial cells as well as a source of crackling sounds in the lung; airway closure from “capillary-elastic instabilities,” as well as nonlinear stabilization from oscillatory core flow which we call the “oscillating butter knife;” liquid film, and surfactant dynamics in an oscillating alveolus and the steady streaming, and surfactant spreading on thin viscous films including our discovery of the Grotberg–Borgas–Gaver shock. PMID:21403768

  10. Respiratory fluid mechanics.

    PubMed

    Grotberg, James B

    2011-02-01

    This article covers several aspects of respiratory fluid mechanics that have been actively investigated by our group over the years. For the most part, the topics involve two-phase flows in the respiratory system with applications to normal and diseased lungs, as well as therapeutic interventions. Specifically, the topics include liquid plug flow in airways and at airway bifurcations as it relates to surfactant, drug, gene, or stem cell delivery into the lung; liquid plug rupture and its damaging effects on underlying airway epithelial cells as well as a source of crackling sounds in the lung; airway closure from "capillary-elastic instabilities," as well as nonlinear stabilization from oscillatory core flow which we call the "oscillating butter knife;" liquid film, and surfactant dynamics in an oscillating alveolus and the steady streaming, and surfactant spreading on thin viscous films including our discovery of the Grotberg-Borgas-Gaver shock.

  11. Several methods for concentrating bacteria in fluid samples

    NASA Technical Reports Server (NTRS)

    Thomas, R. R.

    1976-01-01

    The sensitivities of the firefly luciferase - ATP flow system and luminol flow system were established as 300,000 E. coli per milliliter and 10,000 E. coli per milliliter respectively. To achieve the detection limit of 1,000 bacteria per milliliter previously established, a method of concentrating microorganisms using a sartorius membrane filter system is investigated. Catalase in 50% ethanol is found to be a stable luminol standard and can be used up to 24 hours with only a 10% loss of activity. The luminol reagent is also stable over a 24 hour period. A method of preparing relatively inexpensive luciferase from desiccated firefly tails is developed.

  12. Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

    SciTech Connect

    Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

    2010-04-15

    Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had {sup 125}I and 638 patients had {sup 103}Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline alpha-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm{sup 3}, 25-45 cm{sup 3}, <25 cm{sup 3}; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline alpha-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

  13. Anthropometric changes and fluid shifts

    NASA Technical Reports Server (NTRS)

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  14. Fluid processes in subduction zones.

    PubMed

    Peacock, S A

    1990-04-20

    Fluids play a critical role in subduction zones and arc magmatism. At shallow levels in subduction zones (<40 kilometers depth), expulsion of large volumes of pore waters and CH(4)-H(2)O fluids produced by diagenetic and low-grade metamorphic reactions affect the thermal and rheological evolution of the accretionary prism and provide nutrients for deep-sea biological communities. At greater depths, H(2)O and CO(2) released by metamorphic reactions in the subducting oceanic crust may alter the bulk composition in the overlying mantle wedge and trigger partial melting reactions. The location and conse-quences of fluid production in subduction zones can be constrained by consideration of phase diagrams for relevant bulk compositions in conjunction with fluid and rock pressure-temperature-time paths predicted by numerical heat-transfer models. Partial melting of subducting, amphibole-bearing oceanic crust is predicted only within several tens of million years of the initiation of subduction in young oceanic lithosphere. In cooler subduction zones, partial melting appears to occur primarily in the overlying mantle wedge as a result of fluid infiltration.

  15. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, M.; Ward, R.L.

    1991-12-24

    This patent describes a fluid sampling pump for withdrawing pressurized sample fluid from a flow line and for pumping a preselected quantity of sample fluid with each pump driving stroke from the pump to a sample vessel, the sampling pump including a pump body defining a pump bore therein having a central axis, a piston slideably moveable within the pump bore and having a fluid inlet end and an opposing operator end, a fluid sample inlet port open to sample fluid in the flow line, a fluid sample outlet port for transmitting fluid from the pump bore to the sample vessel, and a line pressure port in fluid pressure sample fluid in the flow line, an inlet valve for selectively controlling sample fluid flow from the flow line through the fluid sample inlet port, an operator unit for periodically reciprocating the piston within the pump bore, and a controller for regulating the stroke of the piston within the pump bore, and thereby the quantity of fluid pumped with each pump driving stroke. It comprises a balanced check valve seat; a balanced check valve seal; a compression member; and a central plunger.

  16. Male-Female Student Retention in HBCUs: A Comparative Analysis of Sample Data across Five Colleges

    ERIC Educational Resources Information Center

    Ezeala-Harrison, Fidel

    2014-01-01

    Several factors contribute to the college retention rates of black students. There could be issues related to the student's own personality attributes, personal and/or family circumstances, financial factors, background events, social factors, as well as a myriad of institutional factors associated with the school system and/or a particular school…

  17. Predictors of Enrollment and Retention in a Preventive Parenting Intervention for Divorced Families

    ERIC Educational Resources Information Center

    Winslow, Emily B.; Bonds, Darya; Wolchik, Sharlene; Sandler, Irwin; Braver, Sanford

    2009-01-01

    Participation rates in parenting programs are typically low, severely limiting the public health significance of these interventions. We examined predictors of parenting program enrollment and retention in a sample of 325 divorced mothers. Predictors included intervention timing and maternal reports of child, parent, family, and sociocultural risk…

  18. A Scholarship Model for Student Recruitment and Retention in STEM Disciplines

    ERIC Educational Resources Information Center

    Yelamarthi, Kumar; Mawasha, P. Ruby

    2010-01-01

    A scholarship program offers enrichment, support, higher recruitment and retention, improved professional development towards employment, and increased graduate opportunities for underrepresented groups. In this paper, it is postulated that the development of a successful and competitive scholarship program is dependent on several variables…

  19. Reflection and Self-Efficacy: Enhancing the Retention of Qualified Teachers from a Teacher Education Perspective

    ERIC Educational Resources Information Center

    Yost, Deborah S.

    2006-01-01

    Teacher retention has been the subject of much study, yet recent estimates of teachers who choose to leave the profession within the first three years to pursue other careers remains at an unacceptably high level of 33.5 percent. These figures are alarming in light of the fact that schools desperately need qualified teachers. Several authors…

  20. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  1. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  2. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  3. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  4. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  5. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  6. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  7. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 28 2011-07-01 2011-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  8. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  9. 40 CFR 307.33 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false Records retention. 307.33 Section 307.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... LIABILITY ACT (CERCLA) CLAIMS PROCEDURES Procedures for Filing and Processing Response Claims §...

  10. Tallahassee Community College Retention Study. Final Report.

    ERIC Educational Resources Information Center

    Johnston, Archie B.

    A retention study was conducted at Tallahassee Community College (TCC) to determine reasons student withdrew from TCC prior to meeting their educational objectives. The survey population consisted of all students, apart from graduates and those who had been academically suspended, who were enrolled in winter 1981 but had not returned by winter…

  11. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2012-01-01 2012-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  12. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2013-01-01 2013-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  13. 7 CFR 275.4 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... corrective action plans. (c) QC review records consist of Forms FNS-380, Worksheet for Supplemental Nutrition... 7 Agriculture 4 2014-01-01 2014-01-01 false Record retention. 275.4 Section 275.4 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

  14. 12 CFR 1026.25 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 9 2014-01-01 2014-01-01 false Record retention. 1026.25 Section 1026.25 Banks... under § 1026.19(e) and (f)) for two years after the date disclosures are required to be made or action... inspect its relevant records for compliance. (c) Records related to certain requirements for...

  15. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  16. Does Retention Help? Perspectives after Three Years.

    ERIC Educational Resources Information Center

    Schuyler, Nancy Baenen

    The Austin Independent School District Office of Research and Evaluation (AISD-ORE) has recently completed a three year study of the effects of retention on elementary students. As in other studies comparing the academic achievement of elementary retainees and similar students not retained, findings indicated that promoted students generally show…

  17. The Literature on Social Promotion versus Retention.

    ERIC Educational Resources Information Center

    Southwest Educational Development Lab., Austin, TX.

    This general review of the relative merits of social promotion and retention examines research on the benefits of each, describes current strategies for resolving the policy dilemma involved, and considers issues raised by abolishing social promotion and establishing remedial programs. A summary of the history of the widespread adoption of the…

  18. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF... requirements of this section, DHS will, after coordination with OPM, issue implementing directives...

  19. Relationship of Personality Traits to Student Retention

    ERIC Educational Resources Information Center

    Liang, John Paul

    2010-01-01

    Carl Jung's theory of psychological types has been the basis for the development of personality categorization, including tests such as Myers-Briggs Type Indicator (MBTI). This study analyzed the extent of the relationship between MBTI and Tinto (1993) retention factors that influence Oriental medicine students' choice of staying or dropping out…

  20. Healthcare Learning Community and Student Retention

    ERIC Educational Resources Information Center

    Johnson, Sherryl W.

    2014-01-01

    Teaching, learning, and retention processes have evolved historically to include multifaceted techniques beyond the traditional lecture. This article presents related results of a study using a healthcare learning community in a southwest Georgia university. The value of novel techniques and tools in promoting student learning and retention…

  1. Retention--A Pseudo-Problem?

    ERIC Educational Resources Information Center

    Geis, George L.

    1999-01-01

    Discusses retention of learning; training methods; maintenance issues; the effect of punishment; reinforcement; the performance environment; transfer of training; forgetting; implications for designers of instructional materials or designers of training programs; and the division between training and on-the-job performance. (LRW)

  2. An Examination of Master's Student Retention & Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Mathies, Charles

    2011-01-01

    This study was conducted at a research-extensive public university in the southeastern United States. It examined the retention and completion of master's degree students across numerous disciplines. Results were derived from a series of descriptive statistics, T-tests, and a series of binary logistic regression models. The findings from binary…

  3. 49 CFR 236.1037 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Records retention. 236.1037 Section 236.1037...; (3) An Operations and Maintenance Manual, pursuant to § 236.1039; and (4) Training and testing... designated office training records required under § 236.1039(b). (d) After the PTC system is placed...

  4. Long-Term Retention of Conditioned Attitudes.

    ERIC Educational Resources Information Center

    Staats, Arthur W.; And Others

    The extent to which semantic differential ratings of trigrams remain consistent over a four-week retention period following pairing with positive or negative attitudinal words was determined. The trigrams initially served as stimulus items in a paired associate list consisting of both positive and negative evaluative response terms; and rating and…

  5. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Record retention. 946.10 Section 946.10 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10...

  6. Alternatives to Social Promotion and Retention

    ERIC Educational Resources Information Center

    Lynch, Matthew

    2013-01-01

    Studies indicate that retention negatively impacts students' behavior, attitude, and attendance, but it is still practiced in schools around the country. Social promotion undermines students' futures when they fail to develop critical study and job-related skills; however, it too is still practiced in many schools throughout the United…

  7. Texas Teacher Recruitment and Retention Study.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This report on teacher recruitment and retention in Texas identifies and analyzes programs offered by higher education institutions, school districts, regional education service centers, and other organizations that address the teacher shortage in Texas. The study was undertaken with the understanding that teacher compensation issues are pervasive…

  8. Effects of Emotional Intelligence on Teacher Retention

    ERIC Educational Resources Information Center

    Gerald, Grant Ronald

    2010-01-01

    This mixed methods, explanatory design study focused on determining if the emotional intelligence of principals affects the retention of new teachers. In phase one, a non-random cluster sample of 138 public school principals in the state of Louisiana was surveyed using a quantitative instrument. A Factor Analysis, Analysis of Variance (ANOVA), and…

  9. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  10. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  11. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  12. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  13. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  14. Employee Retention: A Challenge of the Nineties.

    ERIC Educational Resources Information Center

    Zeiss, Tony

    1990-01-01

    Considers ways in which community colleges can help employers implement programs to improve the work environment and retain trained workers. Presents a model for employee retention that has worked effectively in Pueblo, Colorado. Describes Pueblo Community College's cooperative program with the Wats Marketing Group to help reduce employee…

  15. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  16. High temperature ceramic composition for hydrogen retention

    DOEpatents

    Webb, R.W.

    1974-01-01

    A ceramic coating for H retention in fuel elements is described. The coating has relatively low thermal neutron cross section, is not readily reduced by H at 1500 deg F, is adherent to the fuel element base metal, and is stable at reactor operating temperatures. (JRD)

  17. COMPARTMENTAL MODEL OF NITRATE RETENTION IN STREAMS

    EPA Science Inventory

    A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first order reaction terms to represent nitrate uptake in the free stream, and denitrifica...

  18. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  19. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  20. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  1. 1978-79 Recruitment & Retention Program.

    ERIC Educational Resources Information Center

    DeCosmo, Richard

    The Moraine Valley Community College (MVCC) 1978-79 Recruitment Program seeks to increase the pool of students who wish to attend college rather than compete more aggressively for those students who have already decided to participate in higher education. A special adjunct Retention Program has been developed to enhance the entire recruitment…

  2. Retention and relapse in clinical practice.

    PubMed

    Littlewood, S J; Kandasamy, S; Huang, G

    2017-03-01

    Maintaining teeth in their corrected positions following orthodontic treatment can be extremely challenging. Teeth have a tendency to move back towards the original malocclusion as a result of periodontal, gingival, occlusal and growth related factors. However, tooth movement can also occur as a result of normal age changes. Because orthodontics is unable to predict which patients are at risk of relapse, those which will remain stable and the extent of relapse that will occur in the long-term, clinicians need to treat all patients as if they have a high potential to relapse. To reduce this risk, long term retention is advocated. This can be a significant commitment for patients, and so retention and the potential for relapse must form a key part of the informed consent process prior to orthodontic treatment. It is vital that patients are made fully aware of their responsibilities in committing to wear retainers as prescribed in order to reduce the chance of relapse. If patients are unable or unwilling to comply as prescribed, they must be prepared to accept that there will be tooth positional changes following treatment. There is currently insufficient high quality evidence regarding the best type of retention or retention regimen, and so each clinician's approach will be affected by their personal, clinical experience and expertise, and guided by their patients' expectations and circumstances.

  3. 5 CFR 293.404 - Retention schedule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ....404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Employee Performance File System Records § 293.404 Retention schedule. (a)(1) Except as provided in § 293.405(a), performance ratings or documents supporting them are generally not permanent...

  4. Personnel Recruitment and Retention in Rural America.

    ERIC Educational Resources Information Center

    Helge, Doris; Marrs, Lawrence W.

    Recruitment and retention of special education teachers and related services staff have been persistent problems of rural school districts nationwide. High teacher attrition rates have serious ramifications for personnel development and program stability. Effective recruitment strategies for rural areas have four main components: (1) emphasis on…

  5. Structural Information Retention in Visual Art Processing.

    ERIC Educational Resources Information Center

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  6. Maximizing Female Retention In the Navy

    DTIC Science & Technology

    2014-03-01

    Initiatives in the Workplace ......................................8 b. Diversity Initiatives in the Navy................................................8...11 C. PAST STUDIES OF FEMALE RETENTION IN THE WORKPLACE ... workplace has become an increased focus in America. This is due in part to changing demographics within the United States. As cultural norms change

  7. Reframing Retention Strategy: A Focus on Process

    ERIC Educational Resources Information Center

    Schroeder, Charles C.

    2013-01-01

    When institutions engage in discussions regarding improving retention and graduation rates, invariably the conversation focuses on entering student characteristics, especially ACT and SAT scores and high school grades. Clearly, attracting and enrolling well-prepared and motivated high-ability students will certainly improve institutional measures…

  8. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Records retention. 107.280 Section 107.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... monitor recalls of the formula. Such records shall be retained for at least 1 year after the expiration...

  9. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  10. Recruitment and Retention with a Spin

    ERIC Educational Resources Information Center

    Lindgren, Rita; Hixson, Carla Braun

    2010-01-01

    Strategic planning and innovation at Bismarck State College (BSC) found common ground in the college's goal to recruit and retain employees in an environment of low unemployment and strong competition for skilled employees. BSC's strategic plan for 2007-09 included the objective "to increase retention of employees." One of the strategies…

  11. Testing to Enhance Retention in Human Anatomy

    ERIC Educational Resources Information Center

    Logan, Jessica M.; Thompson, Andrew J.; Marshak, David W.

    2011-01-01

    Recent work in cognitive psychology has shown that repeatedly testing one's knowledge is a powerful learning aid and provides substantial benefits for retention of the material. To apply this in a human anatomy course for medical students, 39 fill-in-the-blank quizzes of about 50 questions each, one for each region of the body, and four about the…

  12. Conjoint Retention of Maps and Related Discourse.

    ERIC Educational Resources Information Center

    Kulhavy, Raymond, W.; And Others

    1985-01-01

    Two experiments used fifth grade students to test the hypothesis that conjointly presented verbal/spatial information facilitates retrieval from either stimulus format. Results support the notion of conjoint retention which assumes that related verbal/spatial arrays are stored in a fashion which allows separate use of both formats during…

  13. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  14. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  15. Water Retention: Relieve This Premenstrual Symptom

    MedlinePlus

    ... If you continue to be troubled by monthly water retention, consult your doctor. He or she might suggest that you keep a symptom diary for a few months. This can help confirm that your symptoms are related to your menstrual cycle, rather than other causes of abdominal bloating — including ...

  16. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-01-01

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  17. Pleural fluid analysis

    MedlinePlus

    ... of fluid that has collected in the pleural space. This is the space between the lining of the outside of the ... the chest. When fluid collects in the pleural space, the condition is called pleural effusion .

  18. Pleural fluid smear

    MedlinePlus

    ... the fluid that has collected in the pleural space. This is the space between the lining of the outside of the ... the chest. When fluid collects in the pleural space, the condition is called pleural effusion .

  19. Peritoneal fluid analysis

    MedlinePlus

    ... at fluid that has built up in the space in the abdomen around the internal organs. This area is called the peritoneal space. ... sample of fluid is removed from the peritoneal space using a needle and syringe. Your health care ...

  20. Fluid sampling tool

    DOEpatents

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  1. Electric fluid pump

    DOEpatents

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  2. Pericardial fluid culture

    MedlinePlus

    ... medlineplus.gov/ency/article/003720.htm Pericardial fluid culture To use the sharing features on this page, please enable JavaScript. Pericardial fluid culture is a test performed on a sample of ...

  3. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-07-06

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  4. Peritoneal fluid culture

    MedlinePlus

    Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... based on more than just the peritoneal fluid culture (which may be negative even if you have ...

  5. Smart Fluids in Hydrology: Use of Non-Newtonian Fluids for Pore Structure Characterization

    NASA Astrophysics Data System (ADS)

    Abou Najm, Majdi; Atallah, Nabil; Selker, John; Roques, Clément; Stewart, Ryan; Rupp, David; Saad, George; El-Fadel, Mutasem

    2016-04-01

    Classic porous media characterization relies on typical infiltration experiments with Newtonian fluids (i.e., water) to estimate hydraulic conductivity. However, such experiments are generally not able to discern important characteristics such as pore size distribution or pore structure. We show that introducing non-Newtonian fluids provides additional unique flow signatures that can be used for improved pore structure characterization. We present a new method that transforms results of N infiltration experiments using water and N-1 non-Newtonian solutions into a system of equations that yields N representative radii (Ri) and their corresponding percent contribution to flow (wi). Those radii and weights are optimized in terms of flow and porosity to represent the functional hydraulic behavior of real porous media. The method also allows for estimating the soil retention curve using only saturated experiments. Experimental and numerical validation revealed the ability of the proposed method to represent the water retention and functional infiltration behavior of real soils. The experimental results showed the ability of such fluids to outsmart Newtonian fluids and infer pore size distribution and unsaturated behavior using simple saturated experiments. Specifically, we demonstrate using synthetic porous media composed of different combinations of sizes and numbers of capillary tubes that the use of different non-Newtonian fluids enables the prediction of the pore structure. The results advance the knowledge towards conceptualizing the complexity of porous media and can potentially impact applications in fields like irrigation efficiencies, vadose zone hydrology, soil-root-plant continuum, carbon sequestration into geologic formations, soil remediation, petroleum reservoir engineering, oil exploration and groundwater modeling.

  6. Reliability of in-stream retention metrics

    NASA Astrophysics Data System (ADS)

    Savickis, Jevgenijs; Zaramella, Mattia; Marion, Andrea

    2016-04-01

    The temporary solute retention within transient storage zones (TSZs) has been shown to have a large effect on the transport of solute. This retention can significantly increase the overall in-stream residence time and as consequence increase the contact time of solute with aquatic interfaces (biota, sediment) and living species. An important question that arises is whether the currently available metrics adequately represent retention mechanism. This work attempts to investigate the reliability of two existing measures, the hydrological retention factor (Rh) and the fraction of median travel time due to transient storage zone (Fmed200). For this purpose, five conservative tracer tests were conducted in four European streams with distinct morphological, sediment composition, vegetation and hydraulic characteristics. The obtained breakthrough curves (BTCs) were used to derive storage zone parameters (storage zone area, storage zone exchange coefficient and mean residence time), which then were used for comparison and in the metric expressions. The storage zone parameters were computed using a single TSZ model OTIS-P and a multiple TSZ model STIR. The STIR model was applied to BTCs as an additional tool to separate TSZs into short timescale (ST) and long timescale (LT). The study results reveal correlation between Fmed200 and LT residence time T2 values, where the streams with the lowest Fmed200 (0.01-0.96) have the smallest long timescale storage zones T2 values, ranging from 912 s to 1402 s. The findings also demonstrate an influence of discharge rate on both retention metrics. The greatest Fmed200 (6.19) and Rh (0.938) values are calculated for the streams with low discharge rates (0.08-0.10 m3s-1) and a relatively high ST storage zone residence times T1 (159 s to 351 s). Results show that the Fmed200 and Rh metrics are strongly affected by the short timescale transient storage zones, whereas the LT storage zones (hyporheic) effects are not taken into account.

  7. Prevention and management of postoperative urinary retention after urogynecologic surgery

    PubMed Central

    Geller, Elizabeth J

    2014-01-01

    Postoperative urinary retention (POUR) is a frequent consequence of gynecologic surgery, especially with surgical correction of urinary incontinence and pelvic organ prolapse. Estimates of retention rates after pelvic surgery range from 2.5%–43%. While there is no standard definition for POUR, it is characterized by impaired bladder emptying, with an elevation in the volume of retained urine. The key to management of POUR is early identification. All patients undergoing pelvic surgery, especially for the correction of incontinence or prolapse, should have an assessment of voiding function prior to discharge. There are several ways to assess voiding function – the gold standard is by measuring a postvoid residual. Management of POUR is fairly straightforward. The goal is to decompress the bladder to avoid long-term damage to bladder integrity and function. The decision regarding when to discontinue catheter-assisted bladder drainage in the postoperative period can be assessed in an ongoing fashion by measurement of postvoid residual. The rate of prolonged POUR beyond 4 weeks is low, and therefore most retention can be expected to resolve spontaneously within 4–6 weeks. When POUR does not resolve spontaneously, more active management may be required. Techniques include urethral dilation, sling stretching, sling incision, partial sling resection, and urethrolysis. While some risk of POUR is inevitable, there are risk factors that are modifiable. Patients that are at higher risk – either due to the procedures being performed or their clinical risk factors – should be counseled regarding the risks and management options for POUR prior to their surgery. Although POUR is a serious condition that can have serious consequences if left untreated, it is easily diagnosed and typically self-resolves. Clinician awareness of the condition and vigilance in its diagnosis are the key factors to successful care for patients undergoing surgical repair. PMID:25210477

  8. Production of biopesticides in an in situ cell retention bioreactor.

    PubMed

    Prakash, Gunjan; Srivastava, Ashok K

    2008-12-01

    The seeds of Azadirachta indica contain azadirachtin and other limonoids, which can be used as a biopesticide for crop protection. Significant variability and availability of seed only in arid zones has triggered biotechnological production of biopesticides to cope up with its huge requirement. Batch cultivation of A. indica suspension culture was carried out in statistically optimized media (25.0 g/l glucose, 5.7 g/l nitrate, 0.094 g/l phosphate and 5 g/l inoculum) in 3 l stirred tank bioreactor. This resulted in 15.5 g/l biomass and 0.05 g/l azadirachtin production in 10 days leading to productivity of 5 mg l(-1) day(-1). Possible inhibition by the limiting substrates (C, N, P) were also studied and maximum inhibitory concentrations identified. The batch kinetic/inhibitory data were then used to develop and identify an unstructured mathematical model. The batch model was extrapolated to simulate continuous cultivation with and without cell retention in the bioreactor. Several offline computer simulations were done to identify right nutrient feeding strategies (with respect to key limiting substrates; carbon, nitrate and phosphate) to maintain non-limiting and non-inhibitory substrate concentrations in bioreactor. One such continuous culture (with cell retention) simulation was experimentally implemented. In this cultivation, the cells were propagated batch-wise for 8 days. It was then converted to continuous cultivation by feeding MS salts with glucose (75 g/l), nitrate (10 g/l), and phosphate (0.5 g/l) at a feed rate of 500 ml/day and withdrawing the spent medium at the same rate. The above continuous cultivation (with cell retention) demonstrated an improvement in cell growth to 95.8 g/l and intracellular accumulation of 0.38 g/l azadirachtin in 40 days leading to an overall productivity of 9.5 mg l(-1) day(-1).

  9. Fluid force transducer

    DOEpatents

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  10. Retention of mercury by salmon

    USGS Publications Warehouse

    Amend, Donald F.

    1970-01-01

    Consuming fish that have been exposed repeatedly to mercury derivatives is a potential public health hazard because fish can accumulate and retain mercury in their tissues (Rucker, 1968). Concern has been expressed in the United States because mercurials have been used extensively in industry and as prophylactic and therapeutic agents in fish hatcheries. Rucker and Amend (1969) showed that yearling rainbow trout (Salmo gairdneri) and chinook salmon (Oncorhynchus tshawytscha) exposed to mercurials accumulated excessive amounts of mercury in many tissues. Further, Rucker and Amend (1969) concluded that wild fish that ate mercury-contaminated fish also could contain high mercury levels. Although mercury was eliminated from most tissues within several months, substantial levels remained in the kidney for more than 33 weeks after the last exposure. Since high levels of mercury can be retained in the kidney for an undetermined time, it is possible that returning adult salmon exposed to mercurials as juveniles could constitute a potential hazard to public health. The purpose of this study was to determine whether such fish contained high residual levels of mercury.

  11. Density-functional theory for polar fluids at functionalized surfaces. I. Fluid-wall association

    NASA Astrophysics Data System (ADS)

    Tripathi, Sandeep; Chapman, Walter G.

    2003-12-01

    We present a novel perturbation density-functional theory (DFT) to describe adsorption of associating fluids on surfaces activated with polar sites to which fluid molecules can bond or associate, such as water adsorbing on activated carbon, silica, clay minerals, etc. Association is modeled within the framework of first order thermodynamic perturbation theory (TPT1). In this first of two papers, we explore in detail the changes brought about in a system due to fluid-wall (FW) association. Hence fluid-fluid association is not considered here. However, the theory can be coupled with existing DF theories of associating fluids to study the interplay between the wall-fluid and fluid-fluid association as is shown in a future paper by S. Tripathi. The proposed theory, in excellent agreement with simulations, shows that FW association significantly changes the fluid structure and adsorption behavior. The theory accurately predicts the distribution of bonded and nonbonded species away from the surface, adsorption characteristics and surface coverage over a range of conditions commonly found in several real systems. The most striking feature of the theory is that in addition to properties away from the wall, it also estimates the distribution of the fluid along the surface, or the three-dimensional (3D) structure, despite being one-dimensional (1D) in form.

  12. Does temporary socket removal affect residual limb fluid volume of trans-tibial amputees?

    PubMed Central

    Sanders, JE; Hartley, TL; Phillips, RH; Ciol, MA; Hafner, BJ; Allyn, KJ; Harrison, DS

    2015-01-01

    Background Lower-limb prosthesis users typically experience residual limb volume losses over the course of the day that can detrimentally affect socket fit. Objectives To determine if temporarily doffing the prosthesis encouraged residual limb fluid volume recovery and if the recovered fluid was maintained. Study Design Experimental design. Methods Residual limb fluid volume was monitored on sixteen participants in three test sessions each. Participants conducted six cycles of resting/standing/walking. Between the third and fourth cycles, participants sat for 30 minutes with the prosthesis and liner: donned (ON), the prosthesis doffed but the liner donned (LINER), or the prosthesis and liner doffed (OFF). Results Percentage fluid volume gain and retention were greatest for the OFF condition followed by the LINER condition. Participants experienced fluid volume losses for the ON condition. Conclusion Doffing the prosthesis and/or liner during rest improved residual limb fluid volume retention compared with leaving the prosthesis and liner donned. Clinical Relevance Practitioners should advise patients who undergo high daily limb volume losses to consider temporarily doffing their prosthesis. Fluid volume retention during subsequent activity will be highest if both the prosthesis and liner are doffed. PMID:25710944

  13. Fluid Movement and Creativity

    ERIC Educational Resources Information Center

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  14. Grazing and no-till cropping impacts on nitrogen retention in dryland agroecosystems.

    PubMed

    Mobley, Megan L; McCulley, Rebecca L; Burke, Ingrid C; Peterson, Gary; Schimel, David S; Cole, C Vernon; Elliott, Edward T; Westfall, Dwayne G

    2014-11-01

    As the world's population increases, marginal lands such as drylands are likely to become more important for food production. One proven strategy for improving crop production in drylands involves shifting from conventional tillage to no-till to increase water use efficiency, especially when this shift is coupled with more intensive crop rotations. Practices such as no-till that reduce soil disturbance and increase crop residues may promote C and N storage in soil organic matter, thus promoting N retention and reducing N losses. By sampling soils 15 yr after a N tracer addition, this study compared long-term soil N retention across several agricultural management strategies in current and converted shortgrass steppe ecosystems: grazed and ungrazed native grassland, occasionally mowed planted perennial grassland, and three cropping intensities of no-till dryland cropping. We also examined effects of the environmental variables site location and topography on N retention. Overall, the long-term soil N retention of >18% in these managed semiarid ecosystems was high compared with published values for other cropped or grassland ecosystems. Cropping practices strongly influenced long-term N retention, with planted perennial grass systems retaining >90% of N in soil compared with 30% for croplands. Grazing management, topography, and site location had smaller effects on long-term N retention. Estimated 15-yr N losses were low for intact and cropped systems. This work suggests that semiarid perennial grass ecosystems are highly N retentive and that increased intensity of semiarid land management can increase the amount of protein harvested without increasing N losses.

  15. Retention of long-term interim restorations with sodium fluoride enriched interim cement

    NASA Astrophysics Data System (ADS)

    Strash, Carolyn

    Purpose: Interim fixed dental prostheses, or "provisional restorations", are fabricated to restore teeth when definitive prostheses are made indirectly. Patients undergoing extensive prosthodontic treatment frequently require provisionalization for several months or years. The ideal interim cement would retain the restoration for as long as needed and still allow for ease of removal. It would also avoid recurrent caries by preventing demineralization of tooth structure. This study aims to determine if adding sodium fluoride varnish to interim cement may assist in the retention of interim restorations. Materials and methods: stainless steel dies representing a crown preparation were fabricated. Provisional crowns were milled for the dies using CAD/CAM technology. Crowns were provisionally cemented onto the dies using TempBond NE and NexTemp provisional cements as well as a mixture of TempBond NE and Duraphat fluoride varnish. Samples were stored for 24h then tested or thermocycled for 2500 or 5000 cycles before being tested. Retentive strength of each cement was recorded using a universal testing machine. Results: TempBond NE and NexTemp cements performed similarly when tested after 24h. The addition of Duraphat significantly decreased the retention when added to TempBond NE. NexTemp cement had high variability in retention over all tested time periods. Thermocycling for 2500 and 5000 cycles significantly decreased the retention of all cements. Conclusions: The addition of Duraphat fluoride varnish significantly decreased the retention of TempBond NE and is therefore not recommended for clinical use. Thermocycling significantly reduced the retention of TempBond NE and NexTemp. This may suggest that use of these cements for three months, as simulated in this study, is not recommended.

  16. 48 CFR 4.705 - Specific retention periods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATIVE MATTERS Contractor Records Retention 4.705 Specific retention periods. The contractor shall retain... specific name or form number. Although the descriptive identifications may not conform to normal...

  17. 48 CFR 4.705 - Specific retention periods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATIVE MATTERS Contractor Records Retention 4.705 Specific retention periods. The contractor shall retain... specific name or form number. Although the descriptive identifications may not conform to normal...

  18. Nutrient retention in riparian floodplains on landscape scale, the necessity for a monthly retention approach.

    PubMed

    Natho, S; Venohr, M

    2012-01-01

    This study analyses the computed nitrogen retention, the distribution and the extent of riparian floodplains of three German rivers, as input data and application of the retention model has not been carried out on landscape scale so far. The Software FLYS 2.1.3 was used for the calculation of the floodplain extent and depth at certain discharges. Thus a first empirical approach is suggested to quantify the share of load that enters the floodplain (incoming load) and the extent of floodplain as variables depending on discharge ratios. Measured loads have subsequently been applied to the presented approach to calculate incoming loads on a monthly and yearly basis for the years 1999 and 2002. Finally, linear and exponential yearly retention models were applied, obtained from the literature. Large variations in the retention results were found between the years and the models and between monthly and yearly calculations. In hydrologically average years, calculated retention rates are in the range of reported values (440-670 kg N ha⁻¹ yr⁻¹), whereas for wet years, retention values account for 1,400 kg N ha⁻¹ yr⁻¹. Consequently, this approach needs to be improved to reduce overestimation by considering more complex characteristics of the floodplain, but generally its application is possible on the landscape scale.

  19. Goal directed fluid therapy.

    PubMed

    Marik, Paul E; Desai, Himanshu

    2012-01-01

    The cornerstone of treating patients with shock remains as it has for decades, intravenous fluids. Surprisingly, dosing intravenous fluid during resuscitation of shock remains largely empirical. Recent data suggests that early aggressive resuscitation of critically ill patients may limit and/or reverse tissue hypoxia, progression to organ failure and improve outcome. However, overzealous fluid resuscitation has been associated with increased complications, increased length of intensive care unit (ICU) and hospital stay and increased mortality. This review focuses on methods to assess fluid responsiveness and the application of these methods for goal directed fluid therapy in critically ill and peri-operative patients.

  20. Green roof stormwater retention: effects of roof surface, slope, and media depth.

    PubMed

    VanWoert, Nicholaus D; Rowe, D Bradley; Andresen, Jeffrey A; Rugh, Clayton L; Fernandez, R Thomas; Xiao, Lan

    2005-01-01

    Urban areas generate considerably more stormwater runoff than natural areas of the same size due to a greater percentage of impervious surfaces that impede water infiltration. Roof surfaces account for a large portion of this impervious cover. Establishing vegetation on rooftops, known as green roofs, is one method of recovering lost green space that can aid in mitigating stormwater runoff. Two studies were performed using several roof platforms to quantify the effects of various treatments on stormwater retention. The first study used three different roof surface treatments to quantify differences in stormwater retention of a standard commercial roof with gravel ballast, an extensive green roof system without vegetation, and a typical extensive green roof with vegetation. Overall, mean percent rainfall retention ranged from 48.7% (gravel) to 82.8% (vegetated). The second study tested the influence of roof slope (2 and 6.5%) and green roof media depth (2.5, 4.0, and 6.0 cm) on stormwater retention. For all combined rain events, platforms at 2% slope with a 4-cm media depth had the greatest mean retention, 87%, although the difference from the other treatments was minimal. The combination of reduced slope and deeper media clearly reduced the total quantity of runoff. For both studies, vegetated green roof systems not only reduced the amount of stormwater runoff, they also extended its duration over a period of time beyond the actual rain event.

  1. Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium

    SciTech Connect

    R.A. Stubbers; G.H. Miley; M. Nieto; W. Olczak; D.N. Ruzic; A. Hassanein

    2004-12-14

    FLIRE was designed to measure the hydrogen and helium retention and diffusivity in a flowing stream of liquid lithium, and it has accomplished these goals. Retention coefficients for helium in the flowing liquid stream were 0.1-2% for flow speeds of 44 cm/s and implantation energies between 500 and 2000 eV. The energy dependence of retention is linear for the energy range considered, as expected, and the dependence of retention on flow velocity fits the expected square-root of flow speed dependence. Estimates of the helium diffusion coefficient in the flowing lithium stream were {approx} 4 x 10{sup -7} cm{sup 2}/s, and are independent of implantation energy. This value is much lower than expected, which could be due to several factors, such as mixing, bubble formation or surface film formation. In the case of hydrogen, long term retention and release mechanisms are of greatest importance, since this relates to tritium inventory in flowing lithium PFCs for fusion applications. The amount of hydride formation was measured for flowing lithium exposed to neutral deuterium gas. Thermal desorption spectroscopy (TDS) measurements indicate that the hydride concentration was between 0.1 and 0.2% over a wide range of pressures (6.5 x 10{sup -5} to 1 Torr). This result implies that the deuterium absorption rate is limited by the surface dissociation rate, since deuterium (hydrogen/tritium) is absorbed in its atomic form, not its molecular form.

  2. Plum and Soy Aglycon Extracts Superior at Increasing Bone Calcium Retention in Ovariectomized Sprague Dawley Rats

    PubMed Central

    2015-01-01

    Plant-derived polyphenols have been shown to influence bone turnover and bone properties in the estrogen-depleted state. We used a crossover design in ovariectomized rats (n = 16 rats for each diet) to investigate the effect of supplementation of two doses each of blueberry, plum, grape, grape seed extract, and resveratrol on bone. We tested the aglycon and glucoside forms of genistein to quantify differences in efficacy on bone calcium retention. Rats were given an intravenous dose of 45Ca to prelabel bone, and bone calcium retention was assessed by urinary excretion of 45Ca:Ca ratio during an intervention period compared with nonintervention. Genistein aglycon increased bone calcium retention significantly (p < 0.05) more than the glucoside (22% vs 13%, respectively). Plum extract (0.45% w/w total dietary polyphenols) and resveratrol (0.2% w/w total dietary polyphenols) were also effective, increasing bone calcium retention by 20% (p = 0.0153) and 14% (p = 0.0012), respectively. Several polyphenolic-rich diets improved bone calcium retention. PMID:24894797

  3. Injuries from Non-Retention in Gillnet Fisheries Suppress Reproductive Maturation in Escaped Fish

    PubMed Central

    Baker, Matthew R.; Swanson, Penny; Young, Graham

    2013-01-01

    Exploitation of fisheries resources has unintended consequences, not only in the bycatch and discard of non-target organisms, but also in damage to targeted fish that are injured by gear but not landed (non-retention). Delayed mortality due to non-retention represents lost reproductive potential in exploited stocks, while not contributing to harvest. Our study examined the physiological mechanisms by which delayed mortality occurs and the extent to which injuries related to disentanglement from commercial gear compromise reproductive success in spawning stocks of Pacific salmon (Oncorhynchus spp.). We found evidence for elevated stress in fish injured via non-retention in gillnet fisheries. Plasma cortisol levels correlated with the severity of disentanglement injury and were elevated in fish that developed infections related to disentanglement injuries. We also analyzed sex steroid concentrations in females (estradiol-17β and 17,20β-dihydroxy-4-pregnen-3-one) to determine whether non-retention impairs reproductive potential in escaped individuals. We demonstrate evidence for delayed or inhibited maturation in fish with disentanglement injuries. These findings have important implications for effective conservation and management of exploited fish stocks and suggest means to improve spawning success in such stocks if retention in commercial fisheries is improved and incidental mortality reduced. PMID:23894510

  4. Prediction of retention in reversed-phase liquid chromatography by means of the polarity parameter model.

    PubMed

    Lázaro, Elisabet; Izquierdo, Pere; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2009-07-03

    The polarity parameter model previously developed: log k=(log k)(0) + p(P(m)(N) - P(s)(N)) has been successfully applied to study several chromatographic systems involving new generation RPLC columns (Luna C18, Resolve C18, XTerra MSC18, and XTerra RP18). In this model the retention of the solutes (log k) is related to a solute parameter (p), a mobile phase parameter (P(m)(N)) and two chromatographic system parameters [P(s)(N) and (log k)(0)]. The studied systems have been characterized with different acetonitrile-water and methanol-water mobile phases, using a set of 12 neutral solutes of different chemical nature. The polarity parameter model allows prediction of retention of any solute in any mobile phase composition just using the retention data obtained in one percentage of organic modifier and the polarity parameters established in the characterization of the chromatographic systems. This model also allows the solute polarity data transference between RPLC characterized systems, so it is possible to predict the retention in various RPLC systems working experimentally with just one of them. Moreover, the global solvation parameter model has also been applied to the same chromatographic systems using a wide set of solutes in order to compare its predictive ability with the one of the polarity parameter model. The results clearly show that both models predict retention with very similar accuracy but the polarity parameter model requires much less preliminary experimental measurements to achieve equivalent results than the global solvation approach.

  5. Predictors of retention in community-based methadone maintenance treatment program in Pearl River Delta, China

    PubMed Central

    2013-01-01

    Background The aims were to identify predictors of treatment retention in methadone maintenance treatment (MMT) clinics in Pearl River Delta, China. Methods Retrospective longitudinal study. Participants: 6 MMT clinics in rural and urban area were selected. Statistical analysis: Stratified random sampling was employed, and the data were analyzed using Kaplan-Meier survival curves and life table method. Protective or risk factors were explored using Cox’s proportional hazards model. Independent variables were enrolled in univariate analysis and among which significant variables were analyzed by multivariate analysis. Results A total of 2728 patients were enrolled. The median of the retention duration was 13.63 months, and the cumulative retention rates at 1,2,3 years were 53.0%, 35.0%, 20.0%, respectively. Multivariate Cox analysis showed: age, relationship with family, live on support from family or friends, income, considering treatment cost suitable, considering treatment open time suitable, addiction severity (daily expense for drug), communication with former drug taking peer, living in rural area, daily treatment dosage, sharing needles, re-admission and history of being arrested were predictors for MMT retention. Conclusions MMT retention rate in Guangdong was low and treatment skills and quality should be improved. Meanwhile, participation of family and society should be encouraged. PMID:23497263

  6. Development of the Orion Crew-Service Module Umbilical Retention and Release Mechanism

    NASA Technical Reports Server (NTRS)

    Delap, Damon C.; Glidden, Joel Micah; Lamoreaux, Christopher

    2013-01-01

    The Orion CSM umbilical retention and release mechanism supports and protects all of the cross-module commodities between the spacecrafts crew and service modules. These commodities include explosive transfer lines, wiring for power and data, and flexible hoses for ground purge and life support systems. The mechanism employs a single separation interface which is retained with pyrotechnically actuated separation bolts and supports roughly two dozen electrical and fluid connectors. When module separation is commanded, either for nominal on-orbit CONOPS or in the event of an abort, the mechanism must release the separation interface and sever all commodity connections within milliseconds of command receipt. There are a number of unique and novel aspects of the design solution developed by the Orion mechanisms team. The design is highly modular and can easily be adapted to other vehiclesmodules and alternate commodity sets. It will be flight tested during Orions Exploration Flight Test 1 (EFT-1) in 2014, and the Orion team anticipates reuse of the design for all future missions. The design packages fluid, electrical, and ordnance disconnects in a single separation interface. It supports abort separations even in cases where aerodynamic loading prevents the deployment of the umbilical arm. Unlike the Apollo CSM umbilical which was a destructive separation device, the Orion design is resettable and flight units can be tested for separation performance prior to flight.Initial development testing of the mechanisms separation interface resulted in binding failures due to connector misalignments. The separation interface was redesigned with a robust linear guide system, and the connector separation and boom deployment were separated into two discretely sequenced events. These changes addressed the root cause of the binding failure by providing better control of connector alignment. The new design was tuned and validated analytically via Monte Carlo simulation. The

  7. The Tennessee Lottery Scholarship Program: Impact on Retention

    ERIC Educational Resources Information Center

    Puryear, Carol G.

    2009-01-01

    This study examined if the Tennessee Education Lottery Scholarship (TELS), which began in 2004, was related to student retention at the six Tennessee Board of Regents four-year institutions. This study investigated the impact of the TELS on student retention at TBR universities and general knowledge regarding retention. Post-facto data were…

  8. Policies and Practice: A Focus on Higher Education Retention.

    ERIC Educational Resources Information Center

    American Association of State Colleges and Universities, Washington, DC.

    This book, based on a discussion at an interactive videoconference, examines student diversity issues and retention strategies in the context of the Sallie Mae National Retention Project that addressed state expectations for more accountability and federal reporting requirements on graduation and retention. The eight chapters focus on equity as it…

  9. 46 CFR 308.600 - Records retention requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Records retention requirement. 308.600 Section 308.600 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE Records Retention § 308.600 Records retention requirement. The records specified in §§ 308.8, 308.517,...

  10. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Retentive and splinting pin. 872.3740 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin. (a) Identification. A retentive and splinting pin is a device made of austenitic alloys or alloys containing...

  11. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Retentive and splinting pin. 872.3740 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin. (a) Identification. A retentive and splinting pin is a device made of austenitic alloys or alloys containing...

  12. 48 CFR 4.704 - Calculation of retention periods.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Calculation of retention periods. 4.704 Section 4.704 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Contractor Records Retention 4.704 Calculation of retention periods. (a) The...

  13. Framing Retention for Institutional Improvement: A 4 Ps Framework

    ERIC Educational Resources Information Center

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps framework for student retention strategy is a construct for reframing the retention discussion in a way that enables institutional improvement by challenging some conventional wisdom and prevailing perspectives that have characterized retention strategy for years. It opens new possibilities for action and improvement by suggesting that…

  14. Retention Initiatives Used by Professional Master's Athletic Training Program Directors

    ERIC Educational Resources Information Center

    Bowman, Thomas G.; Dodge, Thomas M.; Mazerolle, Stephanie M.

    2015-01-01

    Context: Many professional master's athletic training program directors believe retention is a problem facing athletic training education. However, it remains unknown what steps, if any, are taken to improve retention. Objective: To inquire with program directors about their respective methods and interventions aimed at increasing retention rates.…

  15. Measurements of Cs absorption and retention in man

    SciTech Connect

    Henrichs, H.; Paretzke, H.G.; Voigt, G.; Berg, D. )

    1989-10-01

    One of the consequences of the Chernobyl reactor accident in 1986 was a comparatively high contamination of foodstuffs in Southern Federal Republic of Germany. In order to test radioecological models predicting the radiological consequences of such accidents, several thousand measurements were performed to determine Cs body burdens in members of the public. For the interpretation of these data and as a contribution to the improvement of the available database on the biokinetics of Cs isotopes in humans, we followed a small group of volunteers after their consumption of highly contaminated venison. Intakes, excretion rates and total body activities were measured during a period of more than 200 d. The data obtained were evaluated in terms of a compartment model to derive gastrointestinal uptakes, biological half-lives and dose conversion factors. The resulting uptake factors range from 65-90%, the half-lives of the long-term retention from 45 to 200 d. The majority of the resulting dose conversion factors lie below the values recommended by the ICRP, showing that the ICRP model is a reasonable and safe description of the Cs biokinetics in our study group, while the great variability of the results shows that it is not an accurate representation of the individual Cs retention.

  16. In situ monitoring hydrogen isotope retention in ITER first wall

    NASA Astrophysics Data System (ADS)

    Mukhin, E. E.; Andrew, P.; Anthoine, A. D.; Bazhenov, A. N.; Barnsley, R.; Bukreev, I. M.; Bukhovets, V. L.; Chernakov, A. P.; Gorodetsky, A. E.; Kochergin, M. M.; Koval, A. N.; Kukushkin, A. B.; Kukushkin, A. S.; Kurskiev, G. S.; Levashova, M. G.; Litvinov, A. E.; Litunovsky, V. N.; Markin, A. V.; Mazul, I. V.; Masyukevich, S. V.; Miroshnikov, I. V.; Nemov, A. S.; Novokhatsky, A. N.; Razdobarin, A. G.; Sherstnev, E. V.; Samsonov, D. S.; Semenov, V. V.; Smirnov, A. S.; De Temmerman, G.; Tolstyakov, S. Yu.; Zalavutdinov, R. Kh.; Walsh, M. J.

    2016-03-01

    Tritium retention inside the vacuum vessel is a potentially serious constraint in the operation of large-scale fusion machines like ITER. An in situ diagnostics for first wall H/D/T retention by laser induced desorption spectroscopy (LIDS) is proposed for use between plasma discharges. The technique is based on local baking of the first wall by laser irradiation and subsequent analysis of the in-vessel gas by optical emission spectroscopy of plasma radiation. The local heating implementation, kinetics of H/D/T thermal extraction and the accuracy of optical emission spectroscopy measurements are analysed. To resolve the H/D/T lines spectroscopically, their thermal broadening should be minimized to prevent overlapping of the line shapes. A comparative performance analysis of several types of plasma sources with relatively cold ions is made including the following types of discharges: Penning, RF multipactor, laser torch and ECR. All these radiation sources require rather low power and could be used for remote in situ measurements of relative densities of the thermally extracted hydrogen isotopes.

  17. Spinning fluids reactor

    DOEpatents

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  18. Perioperative Fluid Restriction

    PubMed Central

    Bleier, Joshua I.S.; Aarons, Cary B.

    2013-01-01

    Perioperative fluid management of the colorectal surgical patient has evolved significantly over the last five decades. Older notions espousing aggressive hydration have been shown to be associated with increased complications. Newer data regarding fluid restriction has shown an association with improved outcomes. Management of perioperative fluid administration can be considered in three primary phases: In the preoperative phase, data suggests that avoidance of preoperative bowel preparation and avoidance of undue preoperative dehydration can improve outcomes. Although the type of intraoperative fluid given does not have a significant effect on outcome, data do suggest that a restrictive fluid regimen results in improved outcomes. Finally, in the postoperative phase of fluid management, a fluid-restrictive regimen, coupled with early enteral feeding also seems to result in improved outcomes. PMID:24436675

  19. Fluid cooled electrical assembly

    DOEpatents

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  20. The Role of Surface Tension in Colloid Retention and Remobilization during Two-phase Flow

    NASA Astrophysics Data System (ADS)

    Zhang, Q.

    2015-12-01

    During unsaturated flow, the accumulation of colloids at fluid-fluid interfaces (AWIs) and fluid-fluid-solid contact lines (AWSs) depend on those areas and surface tension. The area and capillary forces exerting on colloids can be different by adjusting the liquid-liquid surface tension. In the present work, we adjust only surface tension to change the configuration of AWI and AWSs. Experiments were performed in a Polydimethylsiloxane (PDMS) micro-model. Fluorescent carboxylate-modified polystyrene microspheres, with diameter of 300nm were used as model colloids. Water and fluorinert-FC43 were used as the two immiscible liquids. Given the fact that PDMS is a hydrophobic material, fluorinert was the wetting phase and water was the non-wetting phase in this micro-model. Surface tension was changed by adding fluorinert soluble surfactant into fluorinert-FC43. We visualized colloids interacting with the moving fluid-fluid interfaces by confocal microscopy. We also obtained colloid concentration breakthrough curves by measuring the fluorescent intensities in the outlet of the micro-model. The breakthrough curves showed that under steady-state unsaturated flow, less colloid were retained in the system under low surface tension. The visualization results showed that, under low surface tension, the fluid-fluid interfaces are almost flat, thus less area and short contact line available for colloids to attach to. During transient flow, more colloids were remobilized by the moving fluorinert-water interfaces (FWIs) and fluorinert-water-solid contact lines (FWSCs) under high surface tension. Confocal results and measured breakthrough curves confirmed that lowing surface tension decreased capillary force and liquid-liquid area, resulting less retention and remobilization of colloids.

  1. RETENTION OF HALOCARBONS ON A HEXAFLUOROPROPYLENE-EPOXIDE MODIFIED GRAPHITIZED CARBON BLACK, PART 5: HEAVIER ETHANE- AND ETHENE-BASED COMPOUNDS

    EPA Science Inventory

    The paper gives results of a study of the retention characteristics of 13 heavier ethane-based and 8 ethene-based halocarbon fluids related to alternative refrigerant research as a function of temperature on a stationary phase consisting of a 5% (by mass) coating of a low molecul...

  2. Selective Surface Modification on Lubricant Retention

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

    2016-11-01

    While surface patterns are effective in improving tribological properties, nevertheless they alter the surface wettability, which will in turn affect the surface-lubricant interactions. When there is a shortage of lubricant on a patterned surface, the lubricant stored inside the cavities will be extracted to compensate the surface lubricant dissipation. Additionally, the lubricant retention effect provided by the cavities is competing with the release of the lubricant. With weak surface-lubricant interaction, the retention is limited. Therefore, the lubrication will have a sudden failure, giving a dramatic transition to abrasive wear. To improve the performance of polar lubricants on hydrophobic polymer surfaces, both topographical and selective surface modifications were incorporated on injection molded polypropylene surfaces. Distinctive lubrication improvement was observed when the surface structure density for the lubricant storage was high, and the release of the lubricant was controlled by the interaction with the selectively modified surfaces.

  3. Improving student retention in computer engineering technology

    NASA Astrophysics Data System (ADS)

    Pierozinski, Russell Ivan

    The purpose of this research project was to improve student retention in the Computer Engineering Technology program at the Northern Alberta Institute of Technology by reducing the number of dropouts and increasing the graduation rate. This action research project utilized a mixed methods approach of a survey and face-to-face interviews. The participants were male and female, with a large majority ranging from 18 to 21 years of age. The research found that participants recognized their skills and capability, but their capacity to remain in the program was dependent on understanding and meeting the demanding pace and rigour of the program. The participants recognized that curriculum delivery along with instructor-student interaction had an impact on student retention. To be successful in the program, students required support in four domains: academic, learning management, career, and social.

  4. Retention technique #1. Developing managerial warmth.

    PubMed

    Davidhizar, R

    1989-01-01

    A manager who has interpersonal warmth is not simply gullible or naive, but instead possesses a valuable skill in reaching others. In most manager-employee relationships, some degree of limit-setting and judgment are necessary; however, warmth integrated with limit-setting is more satisfying for both employee and manager. Although warmth as an interpersonal phenomenon is affected by the employee's perception, certain managerial actions can increase the likelihood of being perceived as warm; yet, in spite of careful adherence to the guidelines for communicating warmth, managerial warmth will still be rejected in some situations. As is true of any managerial technique, the effective use of warmth requires an assessment of the employee's personality and the approach most appropriate for the situation at hand. The excellent manager is able to quickly adapt, matching the level of warmth to the situation. See Nurse Manager Retention Factors for viewpoints from nurses themselves. Interpersonal management style is an important retention factor.

  5. Arterial hypertension due to fructose ingestion: model based on intermittent osmotic fluid trapping in the small bowel

    PubMed Central

    2010-01-01

    Based on recently reported data that fructose ingestion is linked to arterial hypertension, a model of regulatory loops involving the colon role in maintenance of fluid and sodium homeostasis is proposed. In normal digestion of hyperosmolar fluids, also in cases of postprandial hypotension and in patients having the "dumping" syndrome after gastric surgery, any hyperosmolar intestinal content is diluted by water taken from circulation and being trapped in the bowel until reabsorption. High fructose corn sirup (HFCS) soft drinks are among common hyperosmolar drinks. Fructose is slowly absorbed through passive carrier-mediated facilitated diffusion, along the entire small bowel, thus preventing absorption of the trapped water for several hours. Here presented interpretation is that ingestion of hyperosmolar HFCS drinks due to a transient fluid shift into the small bowel increases renin secretion and sympathetic activity, leading to rise in ADH and aldosterone secretions. Their actions spare water and sodium in the large bowel and kidneys. Alteration of colon absorption due to hormone exposure depends on cell renewal and takes days to develop, so the momentary capacity of sodium absorption in the colon depends on the average aldosterone and ADH exposure during few previous days. This inertia in modulation of the colon function can make an individual that often takes HFCS drinks prone to sodium retention, until a new balance is reached with an expanded ECF pool and arterial hypertension. In individuals with impaired fructose absorption, even a higher risk of arterial hypertension can be expected. PMID:20579372

  6. When sticky fluids don't stick: yield-stress fluid drops on heated surfaces

    NASA Astrophysics Data System (ADS)

    Blackwell, Brendan; Wu, Alex; Ewoldt, Randy

    2016-11-01

    Yield-stress fluids, including gels and pastes, are effectively fluid at high stress and solid at low stress. In liquid-solid impacts, these fluids can stick and accumulate where they impact; this sticky behavior motivates several applications of these rheologically-complex materials. Here we describe experiments with aqueous yield stress fluids that are more 'sticky' than water at room temperature (e.g. supporting larger coating thicknesses), but are less 'sticky' at higher temperatures. Specifically, we study the conditions for aqueous yield stress fluids to bounce and slide on heated surfaces when water sticks. Here we present high-speed imaging and color interferometry to observe the thickness of the vapor layer between the drop and the surface during both stick and non-stick events. We use these data to gain insight into the physics behind the phenomenon of the yield-stress fluids bouncing and sliding, rather than sticking, on hot surfaces.

  7. The Successful Mobilization of a Campus Community for Student Retention. Report of the University Retention Steering Committee.

    ERIC Educational Resources Information Center

    Eastern Michigan Univ., Ypsilanti.

    Components of a student retention program at Eastern Michigan University are examined; for each effort to improve retention, project objectives and design, results, and recommendations are presented. Retention initiatives, decided upon as a result of a campus-wide mobilization of effort, include: a student-focused orientation system, a fast track…

  8. 78 FR 57927 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ...The OCC, Board, FDIC, Commission, FHFA, and HUD (the agencies) are seeking comment on a joint proposed rule (the proposed rule, or the proposal) to revise the proposed rule the agencies published in the Federal Register on April 29, 2011, and to implement the credit risk retention requirements of section 15G of the Securities Exchange Act of 1934 (15. U.S.C. 78o-11), as added by section 941 of......

  9. Family and Other Impacts on Retention

    DTIC Science & Technology

    1992-04-01

    the first- and second-stage samples were chosen with minimum replacement ( Chromy , 1979). The minimum replacement procedure is equivalent to without...testing differences between groups. REFERENCES Chromy , J. (1979). Sequential sample -election methods. Proceedings of the American Statistical...Soldiers Married to Civilfan Spouses B- 324 Table 5.13 - Standard Errors Retention Plans by Pay Grade and Sense of Community Quality SENSE OF COMMUNITY

  10. Meeting Canadian Forces Expansion Goals through Retention

    DTIC Science & Technology

    2010-05-01

    strategies to improve 13 For the purposes of this study, the Quantitative Group refers to new...the CF. With improved retention, CF expansion and transformation will be facilitated to allow the CF to best meet Canada’s national security...way, under conditions that could lead to loss of life . 23 In no other profession in Canada, (except perhaps in isolated cases, certain emergency

  11. Retention Quick Polls of Three Navy Communities

    DTIC Science & Technology

    2011-03-01

    FY07, and additional incentives are being considered to motivate personnel to “Stay Navy”. Since retention decisions are impacted by a number of...issues, it is useful to know what motivates Sailors to stay or leave, and what incentives influence that decision. This report presents results of...three Navy Quick Polls that asked about job satisfaction, continuation intentions, motivators to stay or leave, and incentives that would increase the

  12. Separation optimization of aniline and seven 4-substituted anilines in high-submicellar liquid chromatography using empirical retention modeling and Derringer's desirability function.

    PubMed

    Hadjmohammadi, Mohammad Reza; S J Nazari, S Saman

    2013-08-01

    The separation optimization of aniline and seven 4-substituted derivatives in high-submicellar LC was performed using an interpretive optimization strategy and Derringer's desirability function. Description of the retention of solutes was carried out through several hyperbolic and logarithmic retention models using the retention data of five mobile phases of SDS (0.06-0.12 M) and methanol (50-70% v/v) at pH 3. Among the investigated models, a logarithmic retention model logk=c0+c1φ+c2[S]+c12φ[S]+d12(φ[S])0.5 showed the best prediction capability and was used to predict the solute retention factors. A grid search program was used to calculate the retention times of each solute, based on the best retention model, for all combinations of SDS and methanol concentrations in the factor space. Two different chromatographic goals, analysis time and retention differences between adjacent peaks, were evaluated simultaneously using Derringer's desirability function for each mobile phase conditions in the grid search. Optimal mobile phase composition for separation of eight anilines was found to be 0.119 M SDS and 53% v/v methanol. Under these conditions, full resolutions with a reasonable analysis time (22 min) were obtained. At the optimal condition, a good agreement was observed between predicted and experimental values of the retention times.

  13. Recruitment and retention of novice faculty.

    PubMed

    Hessler, Karen; Ritchie, Heidi

    2006-05-01

    As nursing faculty members younger than 35, we consider ourselves to be in the minority. Our concern about the future of nursing education has driven us to consider ways to recruit and retain new, young faculty. To stimulate discussion, 10 suggestions for schools of nursing in the recruitment and retention of new faculty are presented: provide guidance, foster socialization, encourage flexibility, conduct orientation, provide support, facilitate collaboration, allow for mistakes, coordinate teaching assignments, grow your own, and offer rewards. While this list is far from complete, we believe it is a starting point from which schools could develop individual strategies for recruitment and retention of faculty members in nursing academia. The nursing shortage continues to intensify the lack of nursing faculty members. As a result, strategies to recruit and retain young faculty members only gain importance. Generations are changing, and it is important that schools of nursing are aware that recruitment and retention strategies that may have been successful in the past, may now be obsolete.

  14. Retention of perceptual generalization of fear extinction.

    PubMed

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed.

  15. High efficiency diffusion molecular retention tumor targeting.

    PubMed

    Guo, Yanyan; Yuan, Hushan; Cho, Hoonsung; Kuruppu, Darshini; Jokivarsi, Kimmo; Agarwal, Aayush; Shah, Khalid; Josephson, Lee

    2013-01-01

    Here we introduce diffusion molecular retention (DMR) tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT) injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding) and RAD (control) probes were synthesized bearing DOTA (for (111) In(3+)), a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111)In] RGD and [(111)In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111)In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.). The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide), which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters) for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  16. Determinants of feedback retention in soccer players

    PubMed Central

    Januário, Nuno; Rosado, António; Mesquita, Isabel; Aguilar-Parra, José M.

    2016-01-01

    Abstract This study analyzed soccer players’ retention of coaches’ feedback during training sessions. We intended to determine if the retention of information was influenced by the athletes’ personal characteristic (age, gender and the sports level), the quantity of information included in coach’s feedback (the number of ideas and redundancy), athletes’ perception of the relevance of the feedback information and athletes’ motivation as well as the attention level. The study that was conducted over the course of 18 sessions of soccer practice, involved 12 coaches (8 males, 4 females) and 342 athletes (246 males, 96 females), aged between 10 and 18 years old. All coach and athlete interventions were transposed to a written protocol and submitted to content analysis. Descriptive statistics and multiple linear regression were calculated. The results showed that a substantial part of the information was not retained by the athletes; in 65.5% of cases, athletes experienced difficulty in completely reproducing the ideas of the coaches and, on average, the value of feedback retention was 57.0%. Six variables with a statistically significant value were found: gender, the athletes’ sports level, redundancy, the number of transmitted ideas, athletes’ perception of the relevance of the feedback information and the athletes’ motivation level. PMID:28149387

  17. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, S.M.; Ward, R.L.

    1992-03-03

    This patent describes a pump for pumping a preselected quantity of fluid with each pump driving stroke from a fluid inlet port to a fluid outlet port, an inlet valve for selectively controlling fluid flow through the fluid inlet port, a pump body defining a pump bore therein, a piston slidably movable within the pump bore and having a fluid inlet end and an opposing operator end, an operator unit for reciprocating the piston within the pump bore, and a manifold interconnect with the pump body. It comprises a flow path therein extending from a manifold inlet port to a manifold outlet port, flow path being in communication with the fluid outlet port in the pump body, a purge passageway extending from the flow path to the outlet passageway, a purge valve for regulating fluid flow through the purge passageway, and a filter positioned within the manifold and extending across a portion of the flow path, the filter defining a filtered zone within the flow path adjoining the inlet port in the pump body, and an unfiltered zone within the flow path extending from the manifold inlet to the manifold outlet, such that filtered fluid enters the pump bore while unfiltered fluid bypasses the filter and passes out the manifold outlet port.

  18. INTRODUCTION OF SPRINKLER FOR CONTINUATION OF WATER RETENTIVENESS

    NASA Astrophysics Data System (ADS)

    Kuribayashi, Mokichi; Yasuda, Kohei

    This report shows the study for the development of the efficient sprinkler system which contribute to the sustainability of water-retentive pavement. Water Retentive Pavement is one of the green engineering that is hoped to mitigate heat-island phenomenon. It is necessary for water retentiveness to keep showing the best performance, because it has shortage of water retentiveness, unless it rains. Therefore, the sprinkler system which is maximized its performance of water retentiveness at any time has been developed and it has started operating in June 2010.

  19. Acetabular pneumatocyst containing air-fluid level.

    PubMed

    Narváez, J A; Narváez, J; Rodríguez-Mijarro, M; Quintero, J C

    1999-01-01

    The presence of intraosseous gas most commonly occurs in osteomyelitis, vacuum phenomenon, and postsurgery or posttraumatic states. Several cases of subchondral gas-filled lesions, called pneumatocysts, have also been described in the sacroiliac joint and clavicle, none of them with intralesional air-fluid level. These pneumatocysts are innocuous lesions of uncertain origin. We describe one case of acetabular pneumatocyst containing air-fluid level in a 62-year-old man with long-standing ankylosing spondylitis involving hip joint. To our knowledge, this is the first reported case of a pneumatocyst in an acetabular location containing air-fluid level.

  20. SANS studies of micellar and magnetic fluids

    SciTech Connect

    Hayter, J.B,

    1985-08-01

    Small-angle neutron scattering (SANS) has proved to be an excellent technique for the study of complex fluids. This article introduces SANS from the viewpoint of such studies. The use of SANS to determine the structures of concentrated micellar fluids is then discussed within the framework of current one-component macrofluid (OCM) models, and experimental examples are taken from several contemporary studies. Finally, the discussion is extended to magnetic fluids (ferrofluids) in which the neutron magnetic interaction plays an important experimental role. 25 refs., 11 figs., 1 tab.

  1. Microwave fluid flow meter

    DOEpatents

    Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.

    1976-01-01

    A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

  2. Fiber optic fluid detector

    DOEpatents

    Angel, S. Michael

    1989-01-01

    Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

  3. Fiber optic fluid detector

    DOEpatents

    Angel, S.M.

    1987-02-27

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  4. Applications of supercritical fluids.

    PubMed

    Brunner, Gerd

    2010-01-01

    This review discusses supercritical fluids in industrial and near-to-industry applications. Supercritical fluids are flexible tools for processing materials. Supercritical fluids have been applied to mass-transfer processes, phase-transition processes, reactive systems, materials-related processes, and nanostructured materials. Some applications are already at industrial capacity, whereas others remain under development. In addition to extraction, application areas include impregnation and cleaning, multistage countercurrent separation, particle formation, coating, and reactive systems such as hydrogenation, biomass gasification, and supercritical water oxidation. Polymers are modified with supercritical fluids, and colloids and emulsions as well as nanostructured materials exhibit interesting phenomena when in contact with supercritical fluids that can be industrially exploited. For these applications to succeed, the properties of supercritical fluids in combination with the materials processed must be clearly determined and fundamental knowledge of the complex behavior must be made readily available.

  5. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    SciTech Connect

    Fox, K.

    2010-09-07

    High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

  6. E. coli RS2GFP Retention Mechanisms in Laboratory-Scale Fractured Rocks: A Statistical Model

    NASA Astrophysics Data System (ADS)

    Rodrigues, S. N.; Qu, J.; Dickson, S. E.

    2011-12-01

    With billions of gallons of groundwater being withdrawn every day in the US and Canada, it is imperative to understand the mechanisms which jeopardize this resource and the health of those who rely on it. Porous media aquifers have typically been considered to provide significant filtration of particulate matter (e.g. microorganisms), while the fractures in fractured rock aquifers and aquitards are considered to act as contaminant highways allowing a large fraction of pathogens to travel deep into an aquifer relatively quickly. Recent research results indicate that fractured rocks filter out more particulates than typically believed. The goal of the research presented here is to quantify the number of E. coli RS2GFP retained in a single, saturated, laboratory-scale fracture, and to relate the retention of E. coli RS2GFP to the aperture field characteristics and groundwater flow rate. To achieve this goal, physical experiments were conducted at the laboratory-scale to quantify the retention of E. coli RS2GFP through several single, saturated, dolomitic limestone fractures under a range of flow rates. These fractures were also cast with a transparent epoxy in order to visualize the transport mechanisms in the various different aperture fields. The E. coli RS2GFP is tagged with a green-fluorescent protein (GFP) that is used to obtain visualization data when excited by ultraviolet light. A series of experiments was conducted, each of which involved the release of a known number of E. coli RS2GFP at the upstream end of the fracture and measuring the effluent concentration profile. These experiments were conducted using both the natural rock and transparent cast of several different aperture fields, under a range of flow rates. The effects of different aperture field characteristics and flow rates on the retention of E. coli RS2GFP will be determined by conducting a statistical analysis of the retention data under different experimental conditions. The images captured

  7. Formation of the ovarian follicular antrum and follicular fluid.

    PubMed

    Rodgers, Raymond J; Irving-Rodgers, Helen F

    2010-06-01

    The formation of the follicular antrum and follicular fluid has received scant attention from researchers, yet both are important processes in follicular development. The central hypothesis on follicular fluid formation suggests that production by granulosa cells of hyaluronan and the chondroitin sulfate proteoglycan versican generates an osmotic gradient. This gradient draws in fluid derived from the thecal vasculature. Inter-alpha-trypsin inhibitor is also present in follicular fluid at least in species with large follicles, and inter-alpha-trypsin inhibitor and versican could additionally bind or cross-link with hyaluronan, resulting in the retention of these molecules within the follicular antrum. Barriers to the movement of fluid across the membrana granulosa are apparently minimal, as even relatively large serum proteins are present in follicular fluid. Despite the relative permeability of the follicular wall, aquaporins are present in granulosa cells and could be actively involved in the transport of water into the follicle. The formation of an antrum also requires movement of granulosa cells relative to each other to allow the fluid to accumulate. This presumably involves remodeling of cell-cell junctions and in species with small follicles may involve death of centrally located granulosa cells. Remodeling of the stroma and thecal layers also accompanies growth and expansion of the antrum and presumably involves similar processes that accompany growth of other glands.

  8. Persistent interface fluid syndrome.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2008-08-01

    We present an unusual case of persistent interface fluid that would not resolve despite normal intraocular pressure and corneal endothelial replacement with Descemet-stripping endothelial keratoplasty. Dissection, elevation, and repositioning of the laser in situ keratomileusis flap were required to resolve the interface fluid. Circumferential corneal graft-host margin scar formation acting as a mechanical strut may have been the cause of the intractable interface fluid.

  9. Solar heat transport fluid

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress made on the development and delivery of noncorrosive fluid subsystems is reported. These subsystems are to be compatible with closed-loop solar heating or combined heating and hot water systems. They are also to be compatible with both metallic and non-metallic plumbing systems. At least 100 gallons of each type of fluid recommended by the contractor will be delivered under the contract. The performance testing of a number of fluids is described.

  10. Fluid pumping system

    SciTech Connect

    Heath, R.T.; Gerlach, C.R.

    1986-05-13

    A fluid pumping system is described for use with a natural gas dehydrating system or the like having an absorber apparatus for removing water from wet natural gas to produce dry natural gas by use of a dessicant agent such as glycol, and a glycol treater apparatus for producing a source of dry glycol from wet glycol received from the absorber apparatus. The system consists of: a fluid pump means operatively connected between dry glycol source and absorber apparatus for pumping dry glycol from the dry glycol source to the absorber apparatus; a fluid operable piston motor means operatively associated with the pump means for driving the pump means and having fluid inlet passage means for receiving wet glycol from the absorber and fluid outlet passage means for delivering wet glycol to the glycol reboiler means wherein energy derived from the flow of fluid passing through the fluid inlet passage means provides the entire motivating force for the motor means and the pump means; the fluid pump means comprising a first pair of equal diameter chamber portion of a double acting piston means having a piston rod with two oppositely positioned piston heads at terminal ends thereof received within two oppositely positioned cylinders mounted on a fixed central body which slidably supports the piston rod; the fluid operable motor means comprising a second pair of equal diameter chamber portions of the double acting piston means; the effective areas of outwardly directed faces of the piston heads being substantially greater than the effective areas of inwardly directed faces of the piston heads; and a wet glycol passage shifting means associated with the fluid motor means for automatically changing the porting of the fluid motor means at the end of a piston stroke for producing reciprocal piston motion in the fluid motor means including toggle means actuated by the piston rod.

  11. Perioperative Fluid Therapy.

    PubMed

    Fantoni, Denise; Shih, Andre C

    2017-03-01

    Anesthesia can lead to pathophysiologic changes that dramatically alter the fluid balance of the body compartments and the intravascular space. Fluid administration can be monitored and evaluated using static and dynamic indexes. Guidelines for fluid rates during anesthesia begin with 3 mL/kg/h in cats and 5 mL/kg/h in dogs. If at all possible, patients should be stabilized and electrolyte disturbances should be corrected before general anesthesia.

  12. Nanoscale Fluid Mechanics and Energy Conversion

    SciTech Connect

    Chen, X; Xu, BX; Liu, L

    2014-05-29

    Under nanoconfinement, fluid molecules and ions exhibit radically different configurations, properties, and energetics from those of their bulk counterparts. These unique characteristics of nanoconfined fluids, along with the unconventional interactions with solids at the nanoscale, have provided many opportunities for engineering innovation. With properly designed nanoconfinement, several nanofluidic systems have been devised in our group in the past several years to achieve energy conversion functions with high efficiencies. This review is dedicated to elucidating the unique characteristics of nanofluidics, introducing several novel nanofluidic systems combining nanoporous materials with functional fluids, and to unveiling their working mechanisms. In all these systems, the ultra-large surface area available in nanoporous materials provides an ideal platform for seamlessly interfacing with nanoconfined fluids, and efficiently converting energy between the mechanical, thermal, and electrical forms. These systems have been demonstrated to have great potentials for applications including energy dissipation/absorption, energy trapping, actuation, and energy harvesting. Their efficiencies can be further enhanced by designing efforts based upon improved understanding of nanofluidics, which represents an important addition to classical fluid mechanics. Through the few systems exemplified in this review, the emerging research field of nanoscale fluid mechanics may promote more exciting nanofluidic phenomena and mechanisms, with increasing applications by encompassing aspects of mechanics, materials, physics, chemistry, biology, etc.

  13. Increased local retention of reef coral larvae as a result of ocean warming

    NASA Astrophysics Data System (ADS)

    Figueiredo, Joana; Baird, Andrew H.; Harii, Saki; Connolly, Sean R.

    2014-06-01

    Climate change will alter many aspects of the ecology of organisms, including dispersal patterns and population connectivity. Understanding these changes is essential to predict future species distributions, estimate potential for adaptation, and design effective networks of protected areas. In marine environments, dispersal is often accomplished by larvae. At higher temperatures, larvae develop faster, but suffer higher mortality, making the effect of temperature on dispersal difficult to predict. Here, we experimentally calibrate the effect of temperature on larval survival and settlement in a dynamic model of coral dispersal. Our findings imply that most reefs globally will experience several-fold increases in local retention of larvae due to ocean warming. This increase will be particularly pronounced for reefs with mean water residence times comparable to the time required for species to become competent to settle. Higher local retention rates strengthen the link between abundance and recruitment at the reef scale, suggesting that populations will be more responsive to local conservation actions. Higher rates of local retention and mortality will weaken connectivity between populations, and thus potentially retard recovery following severe disturbances that substantially deplete local populations. Conversely, on isolated reefs that are dependent on replenishment from local broodstock, increases in local retention may hasten recovery.

  14. Thermogelling magnetorheological fluids

    NASA Astrophysics Data System (ADS)

    Shahrivar, Keshvad; de Vicente, Juan

    2014-02-01

    A novel approach is proposed for the formulation of kinetically stable magnetorheological (MR) fluids exhibiting an MR effect. Thermoresponsive carrier fluids are used which develop a sol-gel transition on increasing the temperature. Turbidity measurements, multiwave rheology and steady shear flow tests are carried out on model conventional MR fluids prepared by dispersion of carbonyl iron microparticles in triblock copolymer solutions of type PEOx-PPOy-PEOx with x = 100 and y = 65. Experiments demonstrate that the MR fluids remain stable against sedimentation in the gel phase and exhibit a very large (relative) MR effect (up to 1000%) in the sol phase.

  15. The Fluids RAP

    NASA Astrophysics Data System (ADS)

    Nedyalkov, Ivaylo

    2016-11-01

    After fifteen years of experience in rap, and ten in fluid mechanics, "I am coming here with high-Reynolds-number stamina; I can beat these rap folks whose flows are... laminar." The rap relates fluid flows to rap flows. The fluid concepts presented in the song have varying complexity and the listeners/viewers will be encouraged to read the explanations on a site dedicated to the rap. The music video will provide an opportunity to share high-quality fluid visualizations with a general audience. This talk will present the rap lyrics, the vision for the video, and the strategy for outreach. Suggestions and comments will be welcomed.

  16. Peritoneal Fluid Analysis

    MedlinePlus

    ... tests for viruses, mycobacteria ( AFB testing in identifying tuberculosis ), and parasites Adenosine deaminase – rarely ordered for detecting tuberculosis in peritoneal fluid ^ Back to top When is ...

  17. Electrorheological fluids and methods

    DOEpatents

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  18. Spiral fluid separator

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A. (Inventor)

    1993-01-01

    A fluid separator for separating particulate matter such as contaminates is provided which includes a series of spiral tubes of progressively decreasing cross sectional area connected in series. Each tube has an outlet on the outer curvature of the spiral. As fluid spirals down a tube, centrifugal force acts to force the heavier particulate matter to the outer wall of the tube, where it exits through the outlet. The remaining, and now cleaner, fluid reaches the next tube, which is smaller in cross sectional area, where the process is repeated. The fluid which comes out the final tube is diminished of particulate matter.

  19. Stationary phases for packed-column supercritical fluid chromatography.

    PubMed

    Poole, Colin F

    2012-08-10

    The properties of silica-based, chemically bonded, packed column stationary phases used in supercritical fluid chromatography are described with a focus on column design and retention mechanisms. Supercritical fluid chromatography has benefited substantially from innovations in column design for liquid chromatography even if the separation conditions employed are generally quite different. The mobile phase composition and column operating conditions play an interactive role in modifying selectivity in supercritical fluid chromatography by altering analyte solubility in the mobile phase and through selective solvation of the stationary phase resulting in a wider range and intensity of intermolecular interactions with the analyte. The solvation parameter model is used to identify the main parameters that affect retention in supercritical fluid chromatography using carbon dioxide-methanol as a mobile phase and as a basis for column characterization to facilitate the identification of stationary phases with different separation characteristics for method development. As a caution it is pointed out that these column characterization methods are possibly a product of both the stationary phase chemistry and the column operating conditions and are suitable for use only when columns of similar design and with similar operating conditions are used.

  20. [Oxytocin and syndrome of inappropriate secretion of antidiuretic neonatal hormone. Case report of early severe hyponatremia and literature review].

    PubMed

    Aldana-Valenzuela, Carlos; Prieto-Pantoja, José Alfredo; Hernández-Acevedo, Angélica

    2010-12-01

    This is a clinical case presentation of a full term newborn infant who suffered severe hyponatremia and early seizures, associated with maternal fluid overload with electrolyte free solutions and high doses of oxytocin for labor augmentation. Although this condition has been recognized since the 1960's with isolated reports, this particular case has features that needs further investigation, not only for the unsually severe hyponatremia, but most importantly we think, for the prominent signs of fluid retention, the infant had, that suggest excessive antidiuretic activity probably due to oxytocin. These findings are consistent with syndrome of inappropriate secretion of antidiuretic hormone. Although until now there is no proof that oxytocin by itself produces this syndrome. We think the association is possible in certain clinical circumstances, such as those found in this case. We also, briefly discussed the pathophysiology of perinatal hyponatremia, the neonatal treatment of this condition and the current guidelines for the women in labor. Hyponatremia should not be considered a benign condition, since in the neonate, it may affect brain function.

  1. Fluid flow monitoring device

    DOEpatents

    McKay, Mark D.; Sweeney, Chad E.; Spangler, Jr., B. Samuel

    1993-01-01

    A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.

  2. Magnetoresistive smart fluid (marsonpol) and devices

    NASA Astrophysics Data System (ADS)

    Reji, John; Suresh, G.; Narayanadas, D. J.

    2003-10-01

    Magnetorheological fluid, Electrorheological fluid and ferro fluids are the smart fluids known today. These fluids are either electrically conductive or non conductive. They do not exhibit variable electrical resistance or switching behavior. Of recent interest to researchers has been the development of new types of magnetoresistive materials. Such materials can be of large practical importance, as they will change their electrical resistance in the presence of a magnetic field. However, most materials only exhibit appreciable magnetoresistance under extreme conditions, such as high magnetic fields or low temperatures. A smart fluid whose electrical resistance can be varied by several orders of magnitude under nominal level of magnetic field is reported in this paper (designated MARSONPOL). In the absence of a magnetic field the fluid is an insulator having electrical resistance in the order of 108 ohm-meter and in the presence of a magnetic field the resistance of the material reduces to less than 1 ohm-meter, at room temperature of 30°C. The sharp and reversible change in resistivity makes the material transform from an insulator to conductor, rendering properties characteristic of either state, within a fraction of a second. Fluids with such characteristics are not reported in the literature making this development a breakthrough and opening up potentials for the development of several smart devices. One such device is the magnetic field sensor probe currently under development at NPOL. A capsule of MARSONPOL forms the basic sensor element. Depending on the strength of the Magnetic field, the electrical resistivity of the capsule undergoes changes. The present paper will discuss details of the smart fluid as well as features of the magnetic field sensor.

  3. The effects of isomaltulose, isomalt, and isomaltulose-based oligomers on mineral absorption and retention.

    PubMed

    Kashimura, J; Kimura, M; Itokawa, Y

    1996-09-01

    We carried out a balance study to examine the effects of isomaltulose, lactose, isomalt, and isomaltulose-based oligomers (IBOs) on mineral (calcium, magnesium, phosphorus, and iron) absorption and retention. Four-week-old male Wistar rats were divided into five groups of six rats each and fed a basal diet or diet the containing either 5% isomaltulose, 5% lactose, 5% isomalts or isomaltulose-based oligomers (IBOs) ad libitum for 16 d. After 1 wk, the animals were subjected to a 5-d mineral (calcium, magnesium, phosphorus, and iron) balance study. The isomalt feeding, as well as the IBOs feeding, led to significantly elevated mineral absorption and retention. On the other hand, lactose feeding, widely known to enhance calcium absorption, increased only calcium absorption and isomaltulose feeding did not affect mineral absorption or retention. The organic acids in cecum contents were increased by IBOs or isomalt feeding. Succinic and acetic acids in cecum contents were significantly increased by IBOs feeding. Similarly, succinic, acetic, and i-valeric acids and total amount of organic acid in cecum content were significantly increased by isomalt feeding. Although the organic acids in cecum contents were increased by IBOs or isomalt feeding, the pH values and acidity in cecum contents were not changed by IBOs or isomalt feeding. The effect of addition of various organic acids to the mucosal fluid was examined with in vitro study using a hindgut segment. By the addition of acetic acid, and butyric acid, the mineral (calcium, magnesium, and phosphorus) uptake was increased.

  4. Effect of age on manganese uptake and retention from milk and infant formulas in rats

    SciTech Connect

    Keen, C.L.; Bell, J.G.; Loennerdal, B.

    1986-03-01

    Manganese nutrition of the neonate is poorly understood, due in part to a paucity of information on the amount and availability of manganese in infant foods. We have developed a suckling pup model to assess the uptake of manganese from fluid diets by using extrinsic labeling. Human milk, cow milk and infant formulas were fed by intubation to fasted rat pups and adults. Rats were killed after varying time periods, and tissues were removed and counted. A period of 6 h was found to be adequate to allow for stomach emptying while limiting tissue redistribution; 24 h was found to reflect pup manganese retention. From human milk, manganese retention was highest (greater than or equal to 80%) in pups less than or equal to 15 days of age; in older pups average retention decreased to 40%. Using d 14 pups to assess relative Mn uptake from diets, wholebody Mn uptake was highest from cow milk (approximately 89%); uptake from human and cow milk formula was similar (approximately 80%) whereas it was lower from soy formula (approximately 60%). These findings suggest that bioavailability of Mn from infant diets is very high during the suckling period. Since most formulas contain considerably more manganese than is found in human milk, Mn deficiency may be less of a concern than possible toxicity from formulas.

  5. Space Station fluid management logistics

    NASA Technical Reports Server (NTRS)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  6. Fluids and Combustion Facility: Fluids Integrated Rack

    NASA Technical Reports Server (NTRS)

    Corban, Robert R.; Winsa, Edward A.

    1998-01-01

    The Fluids Integrated Rack (FIR) is a modular, multi-user facility to accommodate a wide variety of microgravity fluid physics science experiments on-board the US Laboratory Module of the International Space Station (ISS). The FIR is one of three racks comprising the Fluids and Combustion Facility (FCF). The FCF is being designed to increase the amount and quality of scientific data and decrease the development cost of an individual experiment relative to the era of Space Shuttle experiments. The unique, long-term, microgravity environment and long operational times on the ISS will offer experimenters the opportunity to modify experiment parameters based on their findings similar to what can be accomplished in ground laboratories. The FIR concept has evolved over time to provide a flexible, 'optics bench' approach to meet the wide variety of anticipated research needs. The FIR's system architecture presented is designed to meet the needs of the fluid physics community while operating within the constraints of the available ISS resources.

  7. Ontogenetic changes in seminal fluid gene expression and the protein composition of cricket seminal fluid.

    PubMed

    Simmons, Leigh W; Beveridge, Maxine; Li, Lei; Li, Lie; Tan, Yew-Foon; Millar, A Harvey

    2014-03-01

    The ejaculates of most internally fertilizing species consists of both sperm and seminal fluid proteins. Seminal fluid proteins have been studied largely in relation to their post-mating effects on female reproductive physiology, and predominantly in genomically well-characterized species. Seminal fluids can also play important roles in sperm maturation and performance. In the field cricket Teleogryllus oceanicus the viability of ejaculated sperm increases as males age, as does their competitive fertilization success. Here, using quantitative proteomics and quantitative real-time PCR, we document ontogenetic changes in seminal fluid protein abundance and in seminal fluid gene expression. We identified at least nine proteins that changed in abundance in the seminal fluid of crickets as they aged. Gene expression was quantified for five seminal fluid protein genes, and in four of these gene expression changed as males aged. These ontogenetic changes were associated with a general increase in the size of the male accessory glands. Several of the seminal fluid proteins that we have identified are novel, and some have BLAST matches to proteins implicated in sperm function. Our data suggest that age related changes in competitive fertilization success may be dependent on seminal fluid chemistry.

  8. Fluid Bubble Eliminator

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Tsao, Yow-Min (Inventor); Lee, Wenshan (Inventor)

    2005-01-01

    A gas-liquid separator uses a helical passageway to impart a spiral motion to a fluid passing therethrough. The centrifugal fore generated by the spiraling motion urges the liquid component of the fluid radially outward which forces the gas component radially inward. The gas component is then filtered through a gas-permeable, liquid-impervious membrane and discharged through a central passageway.

  9. Fluid bubble eliminator

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Tsao, Yow-Min D. (Inventor); Lee, Wenshan (Inventor)

    2005-01-01

    A gas-liquid separator uses a helical passageway to impart a spiral motion to a fluid passing therethrough. The centrifugal fore generated by the spiraling motion urges the liquid component of the fluid radially outward which forces the gas component radially inward. The gas component is then filtered through a gas-permeable, liquid-impervious membrane and discharged through a central passageway.

  10. Fluid delivery control system

    SciTech Connect

    Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad

    2006-06-06

    A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.

  11. Time Independent Fluids

    ERIC Educational Resources Information Center

    Collyer, A. A.

    1973-01-01

    Discusses theories underlying Newtonian and non-Newtonian fluids by explaining flow curves exhibited by plastic, shear-thining, and shear-thickening fluids and Bingham plastic materials. Indicates that the exact mechanism governing shear-thickening behaviors is a problem of further study. (CC)

  12. Fluid Power Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2008-01-01

    Fluid power technicians, sometimes called hydraulic and pneumatic technicians, work with equipment that utilizes the pressure of a liquid or gas in a closed container to transmit, multiply, or control power. Working under the supervision of an engineer or engineering staff, they assemble, install, maintain, and test fluid power equipment.…

  13. Fluid-loss control

    SciTech Connect

    Crowe, C.W.; Trittipo, B.L. ); Hutchinson, B.H. )

    1989-08-01

    Acid fluid loss is extremely difficult to control and is generally considered to be the major factor limiting the effectiveness of acid fracturing treatments. Chemical erosion of fracture faces and the development of wormholes are largely responsible for the reduced efficiency of acid fracturing fluids. The creation of acid wormholes increases the effective area from which leakoff occurs, thus reducing the acid hydraulic efficiency. Once wormholes form, most acid fluid loss originates from these wormholes rather than penetrating uniformly into the fracture face. Methods of acid fluid-loss control are discussed and evaluated with an improved fluid-loss test procedure. This procedure uses limestone cores of sufficient length to contain wormhole growth. Studies demonstrate that if wormhole growth can be controlled, acid fluid loss approaches that of nonreactive fluids. An improved acid fracturing fluid having unique rheological characteristics is described. This acid has a low initial viscosity but temporarily becomes extremely viscous during leakoff. This high leakoff viscosity blocks wormhole development and prevents acid entry into natural fractures. After the treatment, spent-acid viscosity declines rapidly to ensure easier cleanup.

  14. LARES Mission: Separation and Retention Subsystem

    NASA Technical Reports Server (NTRS)

    Bursi, Alessandro; Camilli, Pierluigi; Piredda, Claudio; Babini, Gianni; Mangraviti, Elio

    2014-01-01

    As part of the Lares (LAser RElativity Satellite) mission, an all-Italian scientific mission launched with the Vega maiden flight in February 2012, a mechanical separation and retention subsystem (SSEP) has been developed to retain the LARES satellite during launch and release it in the final orbit. The design flow was based on the identification of the driving requirements and critical areas to guide the trade-off, design, analysis and test activities. In particular, the SSEP had to face very high environmental loads and to minimize the contact areas with the satellite that had a spherical shape. The test activity overview is provided.

  15. Survey on workforce retention and attrition

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-03-01

    The Society of Petroleum Engineers (SPE) is conducting a survey to gather information on why technical professionals change jobs or quit working. The survey, prompted by concern about the retention of skilled workers, aims to provide information to employers that can assist them in addressing practices that can lead to significant workforce attrition. To participate in the survey, which is open to everyone (including those who are not SPE members), go to http://research.spe.org/se.ashx?s=705E3F1335720258 through 15 May 2013. For more information, contact speresearch@spe.org.

  16. Effect of temperature on the chromatographic retention of ionizable compounds. III. Modeling retention of pharmaceuticals as a function of eluent pH and column temperature in RPLC.

    PubMed

    Gagliardi, Leonardo G; Castells, Cecilia B; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2008-04-01

    We propose a general simple equation for accurately predicting the retention factors of ionizable compounds upon simultaneous changes in mobile phase pH and column temperature at a given hydroorganic solvent composition. Only four independent experiments provide the input data: retention factors measured in two pH buffered mobile phases at extreme acidic and basic pH values (e. g., at least +/- 2 pH units far from the analyte pK(a)) and at two column temperatures. The equations, derived from the basic thermodynamics of the acid-base equilibria, additionally require the knowledge of the solute pK(a )and enthalpies of acid-base dissociation of both the solute and the buffer components in the hydroorganic solvent mixture. The performance of the predictive model is corroborated with the comparison between theoretical and experimental retention factors of several weak acids and bases of important pharmacological activity, in mobile phases containing different buffer solutions prepared in 25% w/w ACN in water and at several temperatures.

  17. [Treatment of severe Rhesus erythroblastosis].

    PubMed

    Bichler, A; Frisch, H

    1977-01-01

    Report about the management of cases of severe Rhesus erythroblastosis. One case is specially discussed because of it's actuality. This was a patient with severe Rh-sensitization (OOD at 450 mm from the beginning of the 30th week of gestation in zone III according to Liley). Because of the haemolytic disease and the chronic fetal distress the Caesarean section was already performed in the 32nd week of gestation after Betamethason treatment of the mother. The Lecithin-Sphingomyelin (L/S) ratio in the amniotic fluid as a criterium of fetal lung maturity raised almost twicefold (from 0.9 to 1.6) after Cortison treatment. The intensive care (assisted ventilation with PEEP, correction of the acidosis and transfusion of packed red cells) of the severely anaemic (Hb 3.5 g%, Hk 15 vol.%) and hydropic newborn was already started in the delivery room. The newborn developed no RDS and was discharged healthy. With reference to this and other cases the management of severe Rh-sensitization before the 34th week of gestation is discussed. Premature infants are mainly susceptable to the development of a Respiratory Distress syndrome (RDS). After antepartum Cortison treatment for prevention of an RDS the date of confinement should be arranged earlier. The value of an early Caesarian section after antepartum Glucocorticoid treatment as compared to the application of intrauterine transfusions in cases of severe erythroblastosis is discussed. It is also reported about recent methods of treatment of severe conditions of hydrops fetalis.

  18. Fluid structure interaction

    NASA Astrophysics Data System (ADS)

    Komatsu, K.

    A few nonflow field problems are considered, taking into account mainly fluid-shell dynamic interaction and fluid-solid impact. Fluid-shell systems are used as models for sloshing and POGO (structure-propulsion coupling oscillation) in liquid rockets, floating lids of oil tanks, large tanks containing fluid, nuclear containment vessels, and head injury studies in biomechanics. The study of structure-water impact finds applications in the problems associated with water landings of reentry vehicles, water entry of torpedoes, and slamming of ships in heavy seas. At least three different methods can be used in handling wet structures. Attention is given to the method which treats fluid by boundary elements and structure by finite elements.

  19. Fluid blade disablement tool

    DOEpatents

    Jakaboski, Juan-Carlos [Albuquerque, NM; Hughs, Chance G [Albuquerque, NM; Todd, Steven N [Rio Rancho, NM

    2012-01-10

    A fluid blade disablement (FBD) tool that forms both a focused fluid projectile that resembles a blade, which can provide precision penetration of a barrier wall, and a broad fluid projectile that functions substantially like a hammer, which can produce general disruption of structures behind the barrier wall. Embodiments of the FBD tool comprise a container capable of holding fluid, an explosive assembly which is positioned within the container and which comprises an explosive holder and explosive, and a means for detonating. The container has a concavity on the side adjacent to the exposed surface of the explosive. The position of the concavity relative to the explosive and its construction of materials with thicknesses that facilitate inversion and/or rupture of the concavity wall enable the formation of a sharp and coherent blade of fluid advancing ahead of the detonation gases.

  20. Constraining the dark fluid

    SciTech Connect

    Kunz, Martin; Liddle, Andrew R.; Parkinson, David; Gao Changjun

    2009-10-15

    Cosmological observations are normally fit under the assumption that the dark sector can be decomposed into dark matter and dark energy components. However, as long as the probes remain purely gravitational, there is no unique decomposition and observations can only constrain a single dark fluid; this is known as the dark degeneracy. We use observations to directly constrain this dark fluid in a model-independent way, demonstrating, in particular, that the data cannot be fit by a dark fluid with a single constant equation of state. Parametrizing the dark fluid equation of state by a variety of polynomials in the scale factor a, we use current kinematical data to constrain the parameters. While the simplest interpretation of the dark fluid remains that it is comprised of separate dark matter and cosmological constant contributions, our results cover other model types including unified dark energy/matter scenarios.