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Sample records for control e-csf osmolarity

  1. Variability of tear osmolarity in dry eye patients and controls

    PubMed Central

    Bunya, Vatinee Y.; Fuerst, Nicole M.; Pistilli, Maxwell; McCabe, Bridgette E.; Salvo, Rebecca; Macchi, Ilaria; Ying, Gui-Shuang; Massaro-Giordano, Mina

    2015-01-01

    Importance Knowledge about the variability of measurements using the TearLab™ osmolarity system is necessary when evaluating the clinical utility of readings. Objective To examine the variability of tear osmolarity, as measured by the TearLab™ system, in subjects with Sjogren's syndrome (SS), blepharitis and controls. Design Cross-sectional study. Setting Tertiary care, academic center. Participants Seventy-four eyes of thirty-seven subjects from a volunteer sample (18 SS, 11 blepharitis, 8 controls) were evaluated using the TearLab™ osmolarity system with three consecutive osmolarity measurements taken at one-minute intervals in a session, and fifteen of these subjects had the same measurements taken by the same examiner in two additional sessions on the same day (9–10am, 12-1pm, or 3–4pm). The majority of SS and blepharitis subjects were on systemic or topical dry eye medications at the time of enrollment. Main Outcome Measures Mean osmolarity and its variability calculated from a linear mixed model for each disease group that accounts for the variations attributable to different subjects, eyes, and sessions, and measurement error specific to each disease group. Results Mean tear osmolarity was 307, 304, and 301 mOsm/L within the SS, blepharitis, and control groups, respectively (p=0.46). The error associated with repeated measurements within a session in the non-dry eye subjects (10.5 [95% CI 9.0, 12.4] mOsm/L) was significantly lower than in the blepharitis (14.6 [12.5, 17.5] mOsm/L, p=0.006) or SS (15.8 [14.2, 17.8] mOsm/L, p<0.0001) subjects, but a difference in the error of repeated measurements between blepharitis and SS subjects was not identified (p=0.46). Conclusions and Relevance There was increased variability attributable to error in repeated measurements among SS and blepharitis subjects compared to controls. The high variability of TearLab™ osmolarity readings in all groups makes clinical interpretation of measurements unclear. PMID

  2. A dual-core double emulsion platform for osmolarity-controlled microreactor triggered by coalescence of encapsulated droplets.

    PubMed

    Guan, Xuewei; Hou, Likai; Ren, Yukun; Deng, Xiaokang; Lang, Qi; Jia, Yankai; Hu, Qingming; Tao, Ye; Liu, Jiangwei; Jiang, Hongyuan

    2016-05-01

    Droplet-based microfluidics has provided a means to generate multi-core double emulsions, which are versatile platforms for microreactors in materials science, synthetic biology, and chemical engineering. To provide new opportunities for double emulsion platforms, here, we report a glass capillary microfluidic approach to first fabricate osmolarity-responsive Water-in-Oil-in-Water (W/O/W) double emulsion containing two different inner droplets/cores and to then trigger the coalescence between the encapsulated droplets precisely. To achieve this, we independently control the swelling speed and size of each droplet in the dual-core double emulsion by controlling the osmotic pressure between the inner droplets and the collection solutions. When the inner two droplets in one W/O/W double emulsion swell to the same size and reach the instability of the oil film interface between the inner droplets, core-coalescence happens and this coalescence process can be controlled precisely. This microfluidic methodology enables the generation of highly monodisperse dual-core double emulsions and the osmolarity-controlled swelling behavior provides new stimuli to trigger the coalescence between the encapsulated droplets. Such swelling-caused core-coalescence behavior in dual-core double emulsion establishes a novel microreactor for nanoliter-scale reactions, which can protect reaction materials and products from being contaminated or released.

  3. [Plasma osmolarity and cerebral volume].

    PubMed

    Boulard, G

    2001-02-01

    Under normal physiological conditions, the osmolarity of extracellular fluids (ECFs) and natremia are controlled by two regulatory mechanisms modulating the water balance and sodium outflow from information collected by the osmoreceptors and baroreceptors, respectively. As well, under normal physiological conditions, water and electrolytes of brain ECFs are secreted by the endothelial cells of brain capillaries. Furthermore, isotonicity is present on both sides of the blood-brain barrier. In the event of systemic osmolarity disorders, water transport subject to osmosis laws occurs at the level of the blood-brain barrier. In the case of plasmatic hyperosmolarity cerebral dehydration is observed, while cerebral edema occurs in the contrary case. However, plasmatic osmolarity disorders have less effect on the cerebral volume when their introduction is slow. Experimentation in acute conditions shows that measured variations of the cerebral water content are lower than calculated variations, thus suggesting the existence of an adaptive mechanism, that is, the cerebral osmoregulation which limits the variation of the volume of brain cells by modulating their osmoactive molecule content. These osmoactive molecules are, on the one hand, the electrolytes, which are early and rapidly mobilized, and, on the other hand, the organic osmoles (amino acids, etc.), whose secretion is slower and delayed. This phenomenon should be taken into account in the treatment of osmolarity disorders. Thus, the related-risk of treatment for natremia disorders is therapeutic reversal of the osmotic gradient at the level of the blood-brain barrier. This reversal, which corresponds to a second osmotic stress, requires the implementation of a new procedure of cerebral osmoregulation in the opposite direction of the preceding one. As successive osmotic stresses decrease the effectiveness of brain osmoregulation, the risk for cerebral dehydration and pontine myelinolysis increases when the treatment

  4. [Tear osmolarity and dry eye].

    PubMed

    Pan, Shi-yin; Xiao, Xiang-hua; Wang, Yang-zheng; Liu, Xian-ning; Zhu, Xiu-ping

    2011-05-01

    Dry eye is a common eye disease, and its incidence rate has been escalating. The increased tear osmolarity is one of the main reasons for complaint, damage and inflammation of dry eye patients. With the breakthrough of testing technology for tear osmolarity, more research and application of tear osmolarity was reported, and papers on tear osmolarity of normal eye and dry eye in different regions were also published. In this article, the progress of the tear osmolarity research, the range of tear osmolarity and its application in diagnosis and therapy of dry eye was introduced, and the prospect for the clinical application of hypotonic artificial tears was also discussed.

  5. Osmolarity and root canal antiseptics.

    PubMed

    Rossi-Fedele, G; Guastalli, A R

    2014-04-01

    Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: 'osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm'. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, 'in press' and 'early view', and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo-osmosis in root canal disinfection, or osmosis in any further desirable

  6. Relationship between extracellular osmolarity, NaCl concentration and cell volume in rat glioma cells.

    PubMed

    Rouzaire-Dubois, Béatrice; Ouanounou, Gilles; Dubois, Jean Marc

    2011-06-01

    The cell volume, which controls numerous cellular functions, is theoretically linearly related with the inverse osmolarity. However, deviations from this law have often been observed. In order to clarify the origin of these deviations we electronically measured the mean cell volume of rat glioma cells under three different experimental conditions, namely: at different osmolarities and constant NaCl concentration; at different NaCl concentrations and constant osmolarity and at different osmolarities caused by changes in NaCl concentration. In each condition, the osmolarity was maintained constant or changed with NaCl or mannitol. We showed that the cell volume was dependent on both the extracellular osmolarity and the NaCl concentration. The relationship between cell volume, osmolarity and NaCl concentration could be described by a new equation that is the product of the Boyle-van't Hoff law and the Michaelis-Menten equation at a power of 4. Together, these results suggest that in hyponatriemia, the cell volume deviates from the Boyle-van't Hoff law because either the activity of aquaporin 1, expressed in glioma cells, is decreased or the reduced NaCl influx decreases the osmotically obliged influx of water.

  7. Tear Osmolarity in Sjogren’s Syndrome

    PubMed Central

    Bunya, Vatinee Y.; Langelier, Nicole; Chen, Sarah; Pistilli, Maxwell; Vivino, Frederick B.; Massaro-Giordano, Giacomina

    2013-01-01

    Purpose The Schirmer test is one of two ocular surface tests included in the current classification criteria for Sjögren’s Syndrome (SS). Tear osmolarity may also be a useful test for the diagnosis of dry eye disease. The purpose of this study was to examine the relationship between tear osmolarity, the Schirmer test I, and dry eye symptoms in SS. Methods Patients with a diagnosis of SS were assessed for tear osmolarity with the TearLab™ Osmolarity System, tear production with Schirmer testing, symptoms with the Ocular Surface Disease Index (OSDI), and discomfort associated with each test. Results Forty-nine patients with a mean age of 53.7 years and a female (92%) predominance were enrolled. The majority of patients (86%) were receiving systemic therapy for severe SS. Higher tear osmolarity was moderately associated with lower scores on the Schirmer test I (ρ = −0.39, P < 0.01) and with lower scores on the OSDI (ρ = −0.45, P < 0.01). Schirmer test I results and lower OSDI scores were not correlated significantly (ρ = 0.20, P = 0.17). Tear osmolarity testing was significantly less painful than Schirmer testing (P < 0.01). Conclusions Signs and symptoms of dry eye in SS patients were not strongly correlated. An unexpected finding was that higher tear osmolarity was associated with lower symptom severity. Tear osmolarity testing in the clinical setting was feasible and was associated with significantly less discomfort than Schirmer testing in patients with severe SS. PMID:23407318

  8. Safety and Efficacy of Low-osmolarity ORS vs. Modified Rehydration Solution for Malnourished Children for Treatment of Children with Severe Acute Malnutrition and Diarrhea: A Randomized Controlled Trial.

    PubMed

    Kumar, Ruchika; Kumar, Praveen; Aneja, S; Kumar, Virendra; Rehan, Harmeet S

    2015-12-01

    World Health Organization-recommended rehydration solution for malnourished children (ReSoMal) for rehydrating severe acute malnourished children is not available in India. In present study, 110 consecutive children aged 6-59 months with severely acute malnourishment and acute diarrhea were randomized to low-osmolarity oral rehydration solution (ORS) (osmolarity: 245, sodium: 75) with added potassium (20 mmol/l) or modified ReSoMal (osmolarity: 300, sodium: 45). In all, 15.4% of modified ReSoMal group developed hyponatremia as compared with 1.9% in low-osmolarity ORS, but none developed severe hyponatremia or hypernatremia. Both groups had equal number of successful rehydration (52 each). Both types of ORS were effective in correcting hypokalemia and dehydration, but rehydration was achieved in shorter duration with modified ReSoMal.

  9. Tear film dynamics with evaporation and osmolarity

    NASA Astrophysics Data System (ADS)

    Siddique, Javed; Braun, Richard

    2011-11-01

    We consider a model problem for the evaporation and breakup up of tear film. The model includes the effects of surface tension, Marangoni stresses, insoluble surfactant transport, evaporation, osmolarity transport, osmosis and wetting of corneal surface. Evaporation is made dependent on surface concentration in order to mimic the lipid layer of the tear film when there is a single fluid layer in the model. In many cases for a single layer, the Marangoni effect seems to eliminate a localized area of increased evaporation due to reduced surfactant concentration. In this model the osmolarity in the tear film increases because of average evaporation rate rather than by a locally increased evaporation rate. If time permits, the effect of having a second fluid layer, representing the lipid layer, will be explored as well.

  10. Influence of osmolarity on the optical properties of human erythrocytes

    NASA Astrophysics Data System (ADS)

    Friebel, Moritz; Helfmann, Jürgen; Meinke, Martina C.

    2010-09-01

    Plasma osmolarity influences the volume and shape of red blood cells (RBCs). The volume change is inversely related to the hemoglobin concentration and as a consequence to the complex refractive index within the cell. These morphological changes can be linked to changes in the optical behavior of the cells. The optical parameters, absorption coefficient μa, scattering coefficient μs, and effective scattering phase function of red blood cells are investigated in dependence on osmolarity in the spectral range from 250 to 1100 nm. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte-Carlo simulations are carried out for osmolarities from 225 to 400 mosmol/L. Osmolarity changes have a significant influence on the optical parameters, which can in part be explained by changes in the complex refractive index, cell shape, and cell volume. Spherical forms of RBCs induced by low osmolarity show reduced scattering effects compared to the normal RBC biconcave disk shape. Spinocytes, which are crenated erythrocytes induced by high osmolarity, show the highest scattering effects. Even only a 10% change in osmolarity has a drastic influence on the optical parameters, which appears to be of the same order as for 10% hematocrit and oxygen saturation changes.

  11. Influence of osmolarity on the optical properties of human erythrocytes.

    PubMed

    Friebel, Moritz; Helfmann, Jürgen; Meinke, Martina C

    2010-01-01

    Plasma osmolarity influences the volume and shape of red blood cells (RBCs). The volume change is inversely related to the hemoglobin concentration and as a consequence to the complex refractive index within the cell. These morphological changes can be linked to changes in the optical behavior of the cells. The optical parameters, absorption coefficient μa, scattering coefficient μs, and effective scattering phase function of red blood cells are investigated in dependence on osmolarity in the spectral range from 250 to 1100 nm. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte-Carlo simulations are carried out for osmolarities from 225 to 400 mosmol/L. Osmolarity changes have a significant influence on the optical parameters, which can in part be explained by changes in the complex refractive index, cell shape, and cell volume. Spherical forms of RBCs induced by low osmolarity show reduced scattering effects compared to the normal RBC biconcave disk shape. Spinocytes, which are crenated erythrocytes induced by high osmolarity, show the highest scattering effects. Even only a 10% change in osmolarity has a drastic influence on the optical parameters, which appears to be of the same order as for 10% hematocrit and oxygen saturation changes.

  12. Tear osmolarity and dry eye symptoms in diabetics

    PubMed Central

    Fuerst, Nicole; Langelier, Nicole; Massaro-Giordano, Mina; Pistilli, Maxwell; Stasi, Kalliopi; Burns, Carrie; Cardillo, Serena; Bunya, Vatinee Y

    2014-01-01

    Purpose To assess the relationship between tear osmolarity and dry eye symptoms in patients with diabetes. Patients and methods Fifty patients with diabetes were enrolled. Demographic information and past medical history were recorded. Symptoms were assessed using the ocular surface disease index (OSDI). Tear osmolarity of each eye was measured with the TearLab® Osmolarity System. Results The majority of the subjects were female (76%), African American (56%), and/or had a diagnosis of type 2 diabetes (82%). The mean ± standard deviation (SD) for age was 54.6±13.4, and maximum tear osmolarity was 304.6±12.7 mOsm/L. Men had higher osmolarity than women (mean ± standard error (SE) 311.8±4.0 mOsm/L versus 302.3±1.9 mOsm/L, P=0.02). Age, race, use of artificial tears, years of diabetes, and hemoglobin A1c did not have a statistically significant association with tear osmolarity. Longer duration of diabetes was associated with lower (less severe) OSDI scores (r=−0.35, P=0.01). Higher tear osmolarity was associated with lower (less severe) OSDI scores (r=−0.29, P=0.04). Conclusion Approximately half of the diabetic subjects in our study had elevated tear osmolarity, and half of our population also reported symptoms consistent with dry eye disease. However, the two were slightly inversely related in that those with higher osmolarity reported fewer symptoms. Subjects with a longer duration of diabetes also reported fewer dry eye symptoms. Therefore, health care providers should be aware that patients who are most likely to have ocular surface disease, including those with long-standing diabetes, may not experience symptoms and seek care in a timely manner. PMID:24648714

  13. Transcriptional profiling of dendritic cells matured in different osmolarities.

    PubMed

    Chessa, Federica; Hielscher, Thomas; Mathow, Daniel; Gröne, Hermann-Josef; Popovic, Zoran V

    2016-03-01

    Tissue-specific microenvironments shape the fate of mononuclear phagocytes [1-3]. Interstitial osmolarity is a tissue biophysical parameter which considerably modulates the phenotype and function of dendritic cells [4]. In the present report we provide a detailed description of our experimental workflow and bioinformatic analysis applied to our gene expression dataset (GSE72174), aiming to investigate the influence of different osmolarity conditions on the gene expression signature of bone marrow-derived dendritic cells. We established a cell culture system involving murine bone marrow cells, cultured under different NaCl-induced osmolarity conditions in the presence of the dendritic cell growth factor GM-CSF. Gene expression analysis was applied to mature dendritic cells (day 7) developed in different osmolarities, with and without prior stimulation with the TLR2/4 ligand LPS.

  14. Effects of sinusoidal magnetic field observed on cell proliferation, ion concentration, and osmolarity in two human cancer cell lines.

    PubMed

    Huang, Lingzhen; Dong, Liang; Chen, Yantian; Qi, Hanshi; Xiao, Dengming

    2006-01-01

    Low frequency magnetic fields have previously been shown to affect cell functions. In this article, the effects of 20 mT, 50 Hz sinusoidal magnetic field on cell proliferation, ion concentration, and osmolarity in two human cancer cell lines (HL-60 and SK-Hep-1) were investigated. Inhibition of cell growth was observed. On the other hand, the exposure also increased the Na+, K+ ion concentration and osmolarity in cell supernatant compared to the control group. To our knowledge, this is the first study on cancer cells where magnetic fields affect osmolarity in cell supernatant. In addition, a model of cells exposed to the oscillating magnetic field is described as well as the characteristics of ions in and out of cells. The experimental data appears to be consistent with the theoretical analysis. The results are also discussed in terms of the relationships among cell growth, ion concentration, and osmolarity. Magnetic field inhibitions of cell growth in vitro may relate to changes in cell ion concentration and osmolarity.

  15. Relationships among Tear Film Stability, Osmolarity, and Dryness Symptoms

    PubMed Central

    Yeh, Thao N.; Graham, Andrew D.; Lin, Meng C.

    2016-01-01

    Purpose To examine the relationships among tear osmolarity, tear film stability, and several measures of dry eye (DE) symptoms in a multivariable analysis. Methods A cross-sectional study was conducted with 137 subjects (68 non–contact lens [CL] wearers and 69 soft CL wearers) recruited from a university campus. Tear breakup time (TBUT) was measured noninvasively (NITBUT) and with fluorescein (FTBUT). Tear osmolarity was measured by an osmometer. Dry eye symptoms were assessed using the Dry Eye Flow Chart and several different questionnaires. Results Subjects ranged in age from 18 to 67 years, with a mean of 28 years. Subjects had a mean (SD) osmolarity of 293 (10) mOsm/L, NITBUT of 14.1 (10.9) seconds, and FTBUT of 14.8 (12.6) seconds. Shorter NITBUT and FTBUT were significantly associated with female sex (p = 0.001 and p = 0.027, respectively) and Asian ethnicity (p = 0.030 and p = 0.004, respectively). There were no clinically significant relationships between tear osmolarity and FTBUT, NITBUT, or DE symptoms. Higher Dry Eye Flow Chart score (i.e., worse symptoms) was associated with older age (p < 0.001), female sex (p = 0.014), CL wear (p < 0.001), shorter NITBUT (p < 0.001), and shorter FTBUT (p = 0.028). The sensitivities and specificities for using clinical measurements to diagnose moderate to severe DE were as follows: osmolarity, 0.67 and 0.46, respectively; NITBUT, 0.72 and 0.52, respectively; and FTBUT, 0.68 and 0.57, respectively. Conclusions In a population of asymptomatic, mild and moderate DE patients, increased tear osmolarity was not significantly associated with reported symptom severity and frequency. Tear osmolarity, NITBUT, and FTBUT exhibited similar sensitivities and specificities when used to diagnose moderate to severe DE. PMID:26154693

  16. Culturing bovine nucleus pulposus explants by balancing medium osmolarity.

    PubMed

    van Dijk, Bart; Potier, Esther; Ito, Keita

    2011-11-01

    Regenerative therapies are promising treatments for early intervertebral disc degeneration. To test their efficacy, an in vitro tissue-level model would be valuable. Nucleus pulposus (NP) explant culture may constitute such a model, as the earliest signs of degeneration are in the NP. However, in NP explant cultures, balancing tissue osmolarity is crucial to preventing swelling, proteoglycan (PG) loss and, therefore, maintaining a native cell environment. In this study, we investigated the effect of medium osmolarity on NP explants. We hypothesized that balancing the inherent tissue osmolarity would prevent swelling and thus maintain NP tissue in a native state. Bovine NP explants were cultured for 21 days in hypo-, iso-, and hyper-tonic conditions using either sucrose or polyethylene glycol (PEG) to raise medium osmolarity. Explants were analyzed for water and biochemical content, cell viability, gene expression, and tissue histology, and compared to day 0 samples. In hypo-tonic and both sucrose cultures, swelling was not prevented, resulting in PG loss and changes in cell behavior. Only PEG cultures maintained water and biochemical content and a histological aspect similar to those of native tissue, with better results for hyper- than for iso-tonic conditions. Using PEG to raise culture medium osmolarity, we were able to maintain the NP tissue specific matrix composition, important for disc cell behavior. This approach, thus, constitutes a promising model to test regenerative therapies for early intervertebral disc degeneration.

  17. Effect of osmolarity on shape retention following laser-mediated cartilage reshaping

    NASA Astrophysics Data System (ADS)

    Karamzadeh, Amir M.; Gray, Darren S.; Kimball, Joey A.; Wong, Brian J.

    2001-07-01

    Laser reshaping of mechanically deformed cartilage specimens accelerates stress relaxation and results in permanent shape change. The mechanism of laser-mediated cartilage reshaping is still unknown, but clearly depends upon the complex molecular interactions between the physio-chemical environment and matrix proteins (collagen, and proteoglycans). It is well known in articular tissues that the mechanical properties of cartilage are sensitive to changes in tissue pH and osmolarity. The objective of this study was to determine the effect of osmolarity on shape change during laser reshaping in morphologic cartilage tissues. Porcine nasal septal cartilage specimens were cut (20 x 5 x 1.5 mm) and immersed in osmotically graded NaCl (0.2NS, 0.8NS, 1.0NS, 1.2 NS and 5 NS) or Phosphate buffered (0.2NS, 0.9NS, 1.0NS, 1.1NS, and 5NS) solutions for 12 hours to establish equilibrium. Then, specimens were bent into semicircular shapes, secured with clamps, and irradiated with an Nd:YAG laser (λ= 1320nm, 5W, 15 secs, 5 mm spot size) along the region of maximum curvature. Resultant bend angle was measured. Shape retention was calculated by comparing resultant curvature with pre-irradiation measurements. Non-irradiated, untreated (negative controls) cartilage retained less than 46% of the original bend. There was no difference in shape retention with respect to varying osmolarity (changed tissue water content) in either group. Resultant bend angles varied from 84 degree(s) to 194 degree(s) corresponding to shape retention varying from 42% to 72% in specimens which were immersed in either NaCl of Phosphate buffered solutions. While laser heating of deformed specimens does result in significant reshaping, the alterations in osmolarity do not seem to effect this process significantly over the range of values evaluated in this study.

  18. Effects of different osmolarities on bacterial biofilm formation

    PubMed Central

    Kavamura, Vanessa Nessner; de Melo, Itamar Soares

    2014-01-01

    Biofilm formation depends on several factors. The influence of different osmolarities on bacterial biofilm formation was studied. Two strains (Enterobacter sp. and Stenotrophomonas sp.) exhibited the most remarkable alterations. Biofilm formation is an important trait and its use has been associated to the protection of organisms against environmental stresses. PMID:25242950

  19. Coupling fluid and solute dynamics within the ocular surface tear film: a modelling study of black line osmolarity.

    PubMed

    Zubkov, V S; Breward, C J W; Gaffney, E A

    2012-09-01

    We present a mathematical model describing the spatial distribution of tear film osmolarity across the ocular surface of a human eye during one blink cycle, incorporating detailed fluid and solute dynamics. Based on the lubrication approximation, our model comprises three coupled equations tracking the depth of the aqueous layer of the tear film, the concentration of the polar lipid, and the concentration of physiological salts contained in the aqueous layer. Diffusive boundary layers in the salt concentration occur at the thinnest regions of the tear film, the black lines. Thus, despite large Peclet numbers, diffusion ameliorates osmolarity around the black lines, but nonetheless is insufficient to eliminate the build-up of solute in these regions. More generally, a heterogeneous distribution of solute concentration is predicted across the ocular surface, indicating that measurements of lower meniscus osmolarity are not globally representative, especially in the presence of dry eye. Vertical saccadic eyelid motion can reduce osmolarity at the lower black line, raising the prospect that select eyeball motions more generally can assist in alleviating tear film hyperosmolarity. Finally, our results indicate that measured evaporative rates will induce excessive hyperosmolarity at the black lines, even for the healthy eye. This suggests that further evaporative retardation at the black lines, for instance due to the cellular glycocalyx at the ocular surface or increasing concentrations of mucus, will be important for controlling hyperosmolarity as the black line thins.

  20. Renal failure in 57 925 patients undergoing coronary procedures using iso-osmolar or low-osmolar contrast media.

    PubMed

    Liss, P; Persson, P B; Hansell, P; Lagerqvist, B

    2006-11-01

    We compared the Swedish Coronary Angiography and Angioplasty Registry with the Swedish 'Hospital Discharge Register' to assess contrast media (CM)-induced renal failure. Hospitals used only one type CM. From 2000 to 2003, iodixanol (iso-osmolar) was used in 45 485 patients, ioxaglate (low osmolar) in 12 440 subjects. To include the earlier used CM iohexol (low osmolar), analysis extended back to 1990 (86 334 patients). Incidence of clinically significant renal failure was greatest for patients receiving the iso-osmolar CM iodixanol (1.7%). Ioxaglate-treated patients had a significantly lower renal failure incidence (0.8%, P<0.001). The odds ratio for iodixanol-treated patients was significantly higher than for ioxaglate (1 vs 0.48, P<0.001). In subsets of either diabetic patients or patients with previous renal failure, odds ratios for renal failure remained greater in the iodixanol groups (P<0.01). Hospitals switching CM to iodixanol experienced a doubling in clinically significant renal failure after cardiac procedures. Dialysis was required in 0.2% of patients receiving iodixanol, which was significantly higher (P<0.01) than for ioxaglate-treated patients (0.1%). Iohexol-treated patients had a similar low risk for developing clinically significant renal failure (0.9%) as ioxaglate. In conclusion, risk of developing renal failure and required dialysis after coronary procedures is higher when patients received iodixanol than ioxaglate or iohexol.

  1. Effect of osmolarity on potassium transport in isolated cerebral microvessels

    SciTech Connect

    Lin, J.D.

    1988-01-01

    Potassium transport in microvessels isolated from rat brain by a technique involving density gradient centrifugation was studied in HEPES buffer solutions of varying osmolarity from 200 to 420 mosmols, containing different concentration of sodium chloride, choline chloride, or sodium nitrate. The flux of /sup 86/Rb into and out of the endothelial cells was estimated. Potassium influx was very sensitive to the osmolarity of the medium. Ouabain-insensitive K-component was reduced in hypotonic medium and was increased in medium made hypertonic with sodium chloride or mannitol. Choline chloride replacement caused a large reduction in K influx. Potassium influx was significant decrease when nitrate is substituted for chloride ion in isotonic and hypertonic media, whereas a slight decrease was found in hypotonic medium. The decrease of K influx in the ion-replacement medium is due to a decrement of the ouabain-insensitive component. Potassium efflux was unchanged in hypotonic medium but was somewhat reduced in hypertonic medium. The marked effect of medium osmolarity of K fluxes suggests that these fluxes may be responsible for the volume regulatory K movements. The possible mechanism of changes of K flux under anisotonic media is also discussed.

  2. Effects of changes in osmolarity on isolated human airways.

    PubMed

    Jongejan, R C; De Jongste, J C; Raatgeep, R C; Bonta, I L; Kerrebijn, K F

    1990-04-01

    The effects of hypo- and hyperosmolarity on the function of isolated human airways were studied. Changes in osmolarity induced an increasing bronchoconstriction that was proportional to the magnitude of the change in osmolarity. Hypertonicity-induced airway narrowing resulted when buffer was made hypertonic with sodium chloride or mannitol but not with urea. The airways showed no tachyphylaxis to repetitive exposure to hypo- and hypertonic buffer of 200 and 600 mosM, respectively. The bronchoconstriction was not secondary to stimulation of H1 or leukotriene C4/D4 receptors or the release of prostaglandins in the preparation. The bronchoconstriction in hypotonic buffer was totally dependent on extracellular calcium, whereas in hypertonic buffer the bronchoconstriction seemed partially dependent on intracellular calcium release. Isoprenaline prevented the bronchoconstriction in hyper- or hypotonic buffer of 450 and 250 mosM but not in buffer of 600 and 150 mosM. It is concluded that hypo- and hypertonic buffers lead to bronchoconstriction via different mechanisms, which relate to influx of extracellular calcium in hyposmolar buffer and probably to release of calcium from intracellular stores in hypertonic buffer. In strongly hypertonic buffer, part of the bronchoconstriction may be due to osmotic shrinkage. The relevance of our data for the mechanism of bronchoconstriction after inhalation of hypo- or hypertonic saline depends on whether changes in osmolarity around the airway smooth muscle occur in asthmatics but not in normal subjects, and this has not yet been established.

  3. Correlation between Osmolarity and Luminescence of Symbiotic Vibrio fischeri Strain ES114

    PubMed Central

    Stabb, Eric V.; Butler, Melissa S.; Adin, Dawn M.

    2004-01-01

    Vibrio fischeri isolates from Euprymna scolopes are dim in culture but bright in the host. We found the luminescence of V. fischeri to be correlated with external osmolarity both in culture and in this symbiosis. Luminescence enhancement by osmolarity was independent of the lux promoter and unaffected by autoinducers or the level of lux expression, but the addition of an aldehyde substrate for luciferase raised the luminescence of cells grown at high and low osmolarities to the same high level. V. fischeri culture media have lower osmolarities than are typical in seawater or in cephalopods, partially accounting for the bacterium's low light output in culture. PMID:15090534

  4. Coupling Osmolarity Dynamics within Human Tear Film on an Eye-Shaped Domain

    NASA Astrophysics Data System (ADS)

    Li, Longfei; Braun, R. J.; Driscoll, T. A.; Henshaw, W. D.; Banks, J. W.; King-Smith, P. E.

    2013-11-01

    The concentration of ions in the tear film (osmolarity) is a key variable in understanding dry eye symptoms and disease. We derived a mathematical model that couples osmolarity (treated as a single solute) and fluid dynamics within the tear film on a 2D eye-shaped domain. The model concerns the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis and tear fluid supply and drainage. We solved the governing system of coupled nonlinear PDEs using the Overture computational framework developed at LLNL, together with a new hybrid time stepping scheme (using variable step BDF and RKC) that was added to the framework. Results of our numerical simulations show good agreement with existing 1D models (for both tear film and osmolarity dynamics) and provide new insight about the osmolarity distribution over the ocular surface during the interblink.

  5. Response of Leptospira interrogans to physiologic osmolarity: relevance in signaling the environment-to-host transition.

    PubMed

    Matsunaga, James; Lo, Miranda; Bulach, Dieter M; Zuerner, Richard L; Adler, Ben; Haake, David A

    2007-06-01

    Transmission of pathogenic Leptospira between mammalian hosts usually involves dissemination via soil or water contaminated by the urine of carrier animals. The ability of Leptospira to adapt to the diverse conditions found inside and outside the host is reflected in its relatively large genome size and high percentage of signal transduction genes. An exception is Leptospira borgpetersenii serovar Hardjo, which is transmitted by direct contact and appears to have lost genes necessary for survival outside the mammalian host. Invasion of host tissues by Leptospira interrogans involves a transition from a low osmolar environment outside the host to a higher physiologic osmolar environment within the host. Expression of the lipoprotein LigA and LigB adhesins is strongly induced by an upshift in osmolarity to the level found in mammalian host tissues. These data suggest that Leptospira utilizes changes in osmolarity to regulate virulence characteristics. To better understand how L. interrogans serovar Copenhageni adapts to osmolar conditions that correspond with invasion of a mammalian host, we quantified alterations in transcript levels using whole-genome microarrays. Overnight exposure in leptospiral culture medium supplemented with sodium chloride to physiologic osmolarity significantly altered the transcript levels of 6% of L. interrogans genes. Repressed genes were significantly more likely to be absent or pseudogenes in L. borgpetersenii, suggesting that osmolarity is relevant in studying the adaptation of L. interrogans to host conditions. Genes induced by physiologic osmolarity encoded a higher than expected number of proteins involved in signal transduction. Further, genes predicted to encode lipoproteins and those coregulated by temperature were overrepresented among both salt-induced and salt-repressed genes. In contrast, leptospiral homologues of hyperosmotic or general stress genes were not induced at physiologic osmolarity. These findings suggest that

  6. Correlation between Tear Osmolarity and Other Ocular Surface Parameters in Primary Sjögren's Syndrome

    PubMed Central

    Kim, Mirinae; Kim, Hyun Seung

    2017-01-01

    Purpose To investigate the relationships between tear osmolarity and other ocular surface parameters and to determine the diagnostic value of tear osmolarity in primary Sjögren's syndrome (SS) using tear film break-up time, Schirmer I test, and cornea/conjunctiva staining. Methods We included 310 eyes of 155 patients diagnosed with dry eye disease (39 primary SS and 116 non-Sjögren dry eye disease) at Seoul St. Mary's Hospital from August 2010 to January 2015. All subjects completed the Ocular Surface Disease Index (OSDI) questionnaire and underwent ocular examinations including tear osmolarity (TearLab Osmolarity System), Schirmer I test, slit lamp examination for tear film break-up time, and corneal and conjunctival fluorescein staining. We used the mean value of both eyes for all parameters. Fluorescein staining was assessed using the Sjögren's International Collaborative Clinical Alliance ocular staining score (OSS). Results In primary SS patients (n = 39), the mean subject age was 52.5 ± 11.9 years, and 94.9% of the subjects were women. Mean tear osmolarity in SS was 311.1 ± 16.4 mOsm/L, with 16 (41.0%) subjects having values ≥316 mOsm/L. In SS, there was a positive correlation between mean tear osmolarity and OSDI score (ρ = 0.405, p = 0.011) and OSS (ρ = 0.592, p < 0.001). There was a negative correlation between mean tear osmolarity and the Schirmer I test (ρ = −0.625, p < 0.001). There was no significant correlation between mean tear osmolarity and tear film break-up time in SS (ρ = 0.110, p = 0.505). Conclusions Tear osmolarity measurements using the TearLab Osmolarity System can reflect both symptom severity (OSDI) and objective signs (Schirmer test and OSS) in SS. PMID:28243020

  7. Paradoxically enhanced heart tolerance to ischaemia in type 1 diabetes and role of increased osmolarity.

    PubMed

    Chen, Hong; Shen, Wei-Li; Wang, Xu-Hui; Chen, Hong-Zhuan; Gu, Jian-Zhong; Fu, Jie; Ni, Ya-Feng; Gao, Ping-Jin; Zhu, Ding-Liang; Higashino, Hideaki

    2006-10-01

    There is considerable controversy regarding the tolerance of diabetic hearts to ischaemia and the underlying mechanisms responsible for the increased heart tolerance to ischamia remain uncertain. In the present study, we observed, in vitro, type 1 diabetic heart responses to ischaemia and reperfusion at different degrees of hyperglycaemia. In addition, the possible role of increased osmolarity in cardioprotection due to hyperglycaemia was evaluated. Hearts from 3 week streptozocin-induced diabetic rats were isolated and perfused in a Langendorff apparatus and subjected to 30 min ischaemia and 30 min reperfusion. Cardiac function and the electrocardiogram were recorded. Myocardial content of osmolarity associated heat shock protein (hsp) 90, heme oxygenase (HO)-1 and anti-oxidant enzymes were determined in diabetic or hyperosmotic solution-perfused hearts using western blot. The hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG; 2 x 10(-7) mol/L) or the nitric oxide synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (1 x 10(-5) mol/L) was added to the perfusate to observe the effects of hsp90 inhibition and hsp90-associated endothelial NOS on ischaemic responses of diabetic hearts. Compared with normal control rats, diabetic hearts with severe hyperglycaemia (blood glucose > 20 mmol/L) showed markedly improved postischaemic heart function with fewer reperfusion arrhythmias. Mild hyperglycaemia (< 12 mmol/L) exhibited no significant cardioprotection. Elevated expression of hsp90 accompanied the enhanced resistance to ischaemia in diabetic hearts, which was abrogated by 17-AAG. In the presence of the NOS inhibitor, heart function was preserved, whereas reperfusion arrhythmias were increased in diabetes. Diabetic hearts also had markedly elevated HO-1 and catalase, with no significant change in superoxide dismutase. Hyperosmotic perfusion with glucose or mannitol also increased myocardial hsp90 and catalase. The present findings reveal that

  8. [Rethinking clinical significance of tear osmolarity measurement for dry eye diagnosis and therapeutic efficacy evaluation].

    PubMed

    Liang, Lingyi; Ke, Hongming; Liu, Zuguo

    2014-09-01

    Increased tear osmolarity is one of the core mechanisms of dry eye and has been considered as an important diagnostic criterion, if not"gold standard", of dry eye. However, recent studies showed the limitations of tear osmolarity measurement not only in the diagnosis, but also in the therapeutic efficacy evaluation of dry eye. The clinical significance of tear osmolarity measurement has become a hot topic of argument. Herein, we review the publications on this topic and try to find the underlying causes of such argument.

  9. The potential role of NFAT5 and osmolarity in peritoneal injury.

    PubMed

    Seeger, Harald; Kitterer, Daniel; Latus, Joerg; Alscher, Mark Dominik; Braun, Niko; Segerer, Stephan

    2015-01-01

    A rise in osmotic concentration (osmolarity) activates the transcription factor Nuclear Factor of Activated T Cells 5 (NFAT5, also known as Tonicity-responsive Enhancer Binding Protein, TonEBP). This is part of a regulatory mechanism of cells adjusting to environments of high osmolarity. Under physiological conditions these are particularly important in the kidney. Activation of NFAT5 results in the modulation of various genes including some which promote inflammation. The osmolarity increases in patients with renal failure. Additionally, in peritoneal dialysis the cells of the peritoneal cavity are repeatedly exposed to a rise and fall in osmotic concentrations. Here we review the current information about NFAT5 activation in uremic patients and patients on peritoneal dialysis. We suggest that high osmolarity promotes injury in the "uremic" milieu, which results in inflammation locally in the peritoneal membrane, but most likely also in the systemic circulation.

  10. Computed tear film and osmolarity dynamics on an eye-shaped domain.

    PubMed

    Li, Longfei; Braun, Richard J; Driscoll, Tobin A; Henshaw, William D; Banks, Jeffrey W; King-Smith, P Ewen

    2016-06-01

    The concentration of ions, or osmolarity, in the tear film is a key variable in understanding dry eye symptoms and disease. In this manuscript, we derive a mathematical model that couples osmolarity (treated as a single solute) and fluid dynamics within the tear film on a 2D eye-shaped domain. The model includes the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis and tear fluid supply and drainage. The governing system of coupled non-linear partial differential equations is solved using the Overture computational framework, together with a hybrid time-stepping scheme, using a variable step backward differentiation formula and a Runge-Kutta-Chebyshev method that were added to the framework. The results of our numerical simulations provide new insight into the osmolarity distribution over the ocular surface during the interblink.

  11. Red cell volume with changes in plasma osmolarity during maximal exercise.

    NASA Technical Reports Server (NTRS)

    Van Beaumont, W.

    1973-01-01

    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  12. Osmolarity regulates chondrogenic differentiation potential of synovial fluid derived mesenchymal progenitor cells.

    PubMed

    Bertram, Karri L; Krawetz, Roman J

    2012-06-08

    Cartilage is one of few tissues where adult stem/progenitor cells have not been putatively identified. Recent studies have provided strong evidence that a sub-population of mesenchymal progenitor cells (MPCs) derived from the synovial fluid may be able to affect some degree of cartilage repair both in vivo and in vitro/ex vivo, however this does not appear to be the case in patients with arthritis. Previously, it has been found that synovial fluid osmolarity is decreased in patients with osteoarthritis (OA) or Rheumatoid arthritis (RA) and these changes in osmolarity have been linked to changes in chondrocyte gene regulation. However, it is yet unknown if changes in osmolarity regulate the gene expression in synovial fluid MPCs (sfMPCs), and by extension, chondrogenesis of this cell population. In the present study we have collected synovial fluid samples from normal, OA and RA knee joints, quantified the osmolarity of the fluid and modified the culture/differentiation media to span a range of osmolarities (264-375 mOsm). Chondrogenesis was measured with Alcian blue staining of cultures in addition to quantitative PCR (qPCR) using probes to Sox9, ACAN and Col2A1. Overall, sfMPCs from arthritic joints demonstrated decreased chondrogenic potential compared to sfMPCs isolated from normal synovial fluid. Furthermore, the sfMPCs retained increased chondrogenic potential if differentiated under the same osmolarity conditions for which they were initially derived within. In conclusion, it does appear the synovial fluid osmolarity regulates the chondrogenic potential of sfMPCs, however, further study is required to elucidate the mechanism by which the changes in osmolarity are sensed by the cells and regulate chondrogenic gene expression.

  13. Changes in central sodium and not osmolarity or lactate induce panic-like responses in a model of panic disorder.

    PubMed

    Molosh, Andre I; Johnson, Philip L; Fitz, Stephanie D; Dimicco, Joseph A; Herman, James P; Shekhar, Anantha

    2010-05-01

    Panic disorder is a severe anxiety disorder characterized by recurrent panic attacks that can be consistently provoked with intravenous (i.v.) infusions of hypertonic (0.5 M) sodium lactate (NaLac), yet the mechanism/CNS site by which this stimulus triggers panic attacks is unclear. Chronic inhibition of GABAergic synthesis in the dorsomedial hypothalamus/perifornical region (DMH/PeF) of rats induces a vulnerability to panic-like responses after i.v. infusion of 0.5 M NaLac, providing an animal model of panic disorder. Using this panic model, we previously showed that inhibiting the anterior third ventricle region (A3Vr; containing the organum vasculosum lamina terminalis, the median preoptic nucleus, and anteroventral periventricular nucleus) attenuates cardiorespiratory and behavioral responses elicited by i.v. infusions of NaLac. In this study, we show that i.v. infusions of 0.5 M NaLac or sodium chloride, but not iso-osmolar D-mannitol, increased 'anxiety' (decreased social interaction) behaviors, heart rate, and blood pressure responses. Using whole-cell patch-clamp preparations, we also show that bath applications of NaLac (positive control), but not lactic acid (lactate stimulus) or D-mannitol (osmolar stimulus), increases the firing rates of neurons in the A3Vr, which are retrogradely labeled from the DMH/PeF and which are most likely glutamatergic based on a separate study using retrograde tracing from the DMH/PeF in combination with in situ hybridization for vesicular glutamate transporter 2. These data show that hypertonic sodium, but not hyper-osmolarity or changes in lactate, is the key stimulus that provokes panic attacks in panic disorder, and is consistent with human studies.

  14. The effect of reductive ventricular osmotherapy on the osmolarity of artificial cerebrospinal fluid and the water content of cerebral tissue ex vivo.

    PubMed

    Odland, Rick M; Panter, S Scott; Rockswold, Gaylan L

    2011-01-01

    The purpose of this study was to explore a novel treatment involving removal of free water from ventricular cerebrospinal fluid (CSF) for the reduction of cerebra]l edema. The hypothesis is that removal of free water from the CSF will increase the osmolarity of the CSF, which will favor movement of tissue-bound water into the ventricles, where the water can be removed. Reductive ventricular osmotherapy (RVOT) was tested in a flowing solution of artificial CSF (aCSF) with two end-points: (1) the effect of RVOT on osmolarity of the CSF, and (2) the effect of RVOT on water content of ex vivo cerebral tissue. RVOT catheters are made up of membranes permeable only to water vapor. When a sweep gas is drawn through the catheter, free water in the form of water vapor is removed from the solution. With RVOT treatment, aCSF osmolarity increased from a baseline osmolarity of 318.8 ± 0.8 mOsm/L to 339.0 ± 3.3 mOsm/L (mean ± standard deviation) within 2 h. After 10 h of treatment, aCSF osmolarity approached an asymptote at 344.0 ± 4.2 mOsm/L, which was significantly greater than control aCSF osmolarity (p <0.001 by t-test, n = 8). Water content at the end of 6 h of circulating aCSF exposure was 6.4 ± 0.9 g H₂O (g dry wt)⁻¹ in controls, compared to 6.1 ± 0.7 g H₂O (g dry wt)⁻ after 6 h of RVOT treatment of aCSF (p = 0.02, n = 24). The results support the potential of RVOT as a treatment for cerebral edema and intracranial hypertension.

  15. Growth and buoyant density of Escherichia coli at very low osmolarities.

    PubMed

    Baldwin, W W; Myer, R; Kung, T; Anderson, E; Koch, A L

    1995-01-01

    The growth and buoyant densities of two closely related strains of Escherichia coli in M9-glucose medium that was diluted to produce osmolarities that varied from as low as 5 to 500 mosM were monitored. At 15 mosM, the lowest osmolarity at which buoyant density could be measured reproducibly in Percoll gradients, both ML3 and ML308 had a buoyant density of about 1.079 g/ml. As the osmolarity of the medium was increased, the buoyant density also increased linearly up to about 125 mosM, at which the buoyant density was 1.089 g/ml. From 150 up to 500 mosM, the buoyant density again increased linearly but with a different slope from that seen at the lower osmolarities. The buoyant density at 150 mosM was about 1.091 g/ml, and at 500 mosM it was 1.101 g/ml. Both strains of E. coli could be grown in M9 medium diluted 1:1 with water, with an osmolarity of 120 mosM, but neither strain grew in 1:2-diluted M9 if the cells were pregrown in undiluted M9. (Note: undiluted M9 as prepared here has an osmolarity of about 250 mosM.) However, if the cells were pregrown in 30% M9, about 75 mosM, they would then grow in M9 at 45 mosM and above but not below 40 mosM. To determine which constituent of M9 medium was being diluted to such a low level that it inhibited growth, diluted M9 was prepared with each constituent added back singly. From this study, it was determined that both Ca2+ and Mg2+ could stimulate growth below 40 mosM. With Ca2+ - and Mg2+ -supplemented diluted M9 and cells pregrown in 75 mosM M9, it was possible to grow ML308 in 15 mosM M9. Strain ML3 would only haltingly grow at 15 mosM. Four attempts were made to grow both ML3 and ML308 at 5 mosM. In three of the experiments, ML308 grew, while strain ML3 grew in one experiment. While our experiments were designed to effect variations in medium osmolarity by using NaCl as an osmotic agent, osmolarity and salinity were changed concurrently. Therefore, from this study, we believe that E. coli might be defined as an

  16. An examination of the relationship between ocular surface tear osmolarity compartments and epitheliopathy.

    PubMed

    McMonnies, Charles W

    2015-04-01

    A 2014 PubMed search for tear hyperosmolarity and corneal stain yielded 2960 results. Selections from those providing evidence of variations in osmolarity were used to refine the compartmentalization model of tear osmolarity over the ocular surface. This new model includes the low point of freshly produced isotonic tears in the upper conjunctival sac, with osmolarity increasing successively in the upper meniscus, the upper area of exposed ocular surface, the lower area of over-exposed ocular surface, the lower meniscus, and the lower conjunctival sac. Compartmentalization is used to explain epitheliopathy over the ocular surface as resulting from variable degrees of exposure to hyperosmolarity-induced insult and/or friction-related mechanical damage. Also recognized is the role of localized increases in osmolarity, which appear likely to occur in the black lines and tear breakup areas of the exposed ocular surface. Variables such as the influence of ambient conditions of air humidity, temperature and movement have been considered, as well as rates of complete and incomplete blinks and associated potential for over-exposure of the inferior area of the normally exposed ocular surface. The exacerbating contribution from contact lens wear has been included. Friction-related damage may be the primary basis for lid wiper epitheliopathy, but tear hyperosmolarity could have an important contributory role. Subcompartmental consideration of variation in osmolarity may improve understanding of different presentations of epitheliopathy.

  17. Changes in the osmolarity of the embryonic microenvironment induce neural tube defects.

    PubMed

    Jin, Yi-Mei; Wang, Guang; Zhang, Nuan; Wei, Yi-Fan; Li, Shuai; Chen, You-Peng; Chuai, Manli; Lee, Henry Siu Sum; Hocher, Berthold; Yang, Xuesong

    2015-05-01

    Many maternal disorders that modify the embryonic microenvironment, such as a change in osmolarity, can affect development, but how these changes influence the early embryo remains obscure. Neural tube defects, for example, are common congenital disorders found in fetus and neonates. In this study, we investigated the impact of anisotonic osmolarity (unequal osmotic pressures) on neural tube development in the early chick embryo, finding that neuronal cell differentiation was impaired in the neural tube due to enhanced apoptosis and repressed cell proliferation. Anisotonic osmolarity also affected normal development of the neural crest, which in turn influenced abnormal development of the neural tube. As neural tube development is highly dependent on the proper expression of bone morphogenetic protein 4 (BMP4), paired box 7 (PAX7), and sonic hedgehog (SHH) genes in the dorsal and ventral regions along the tube, we investigated the impact of anisotonic osmolarity on their expression. Indeed, small changes in osmolarity could positively and negatively impact the expression of these regulatory genes, which profoundly affected neural tube development. Thus, both the central and peripheral nervous systems were perturbed by anisotonic consitions as a consequence of the abnormal expression of key genes within the developing neural tube.

  18. High osmolarity glycerol response PtcB phosphatase is important for Aspergillus fumigatus virulence.

    PubMed

    Winkelströter, Lizziane K; Bom, Vinícius Leite Pedro; de Castro, Patrícia Alves; Ramalho, Leandra Naira Zambelli; Goldman, Maria Helena S; Brown, Neil Andrew; Rajendran, Ranjith; Ramage, Gordon; Bovier, Elodie; Dos Reis, Thaila Fernanda; Savoldi, Marcela; Hagiwara, Daisuke; Goldman, Gustavo H

    2015-04-01

    Aspergillus fumigatus is a fungal pathogen that is capable of adapting to different host niches and to avoid host defenses. An enhanced understanding of how, and which, A. fumigatus signal transduction pathways are engaged in the regulation of these processes is essential for the development of improved disease control strategies. Protein phosphatases are central to numerous signal transduction pathways. To comprehend the functions of protein phosphatases in A. fumigatus, 32 phosphatase catalytic subunit encoding genes were identified. We have recognized PtcB as one of the phosphatases involved in the high osmolarity glycerol response (HOG) pathway. The ΔptcB mutant has both increased phosphorylation of the p38 MAPK (SakA) and expression of osmo-dependent genes. The ΔptcB strain was more sensitive to cell wall damaging agents, had increased chitin and β-1,3-glucan, and impaired biofilm formation. The ΔptcB strain was avirulent in a murine model of invasive pulmonary aspergillosis. These results stress the importance of the HOG pathway in the regulation of pathogenicity determinants and virulence in A. fumigatus.

  19. Bovine serum albumin: survival and osmolarity effect in bovine spermatozoa stored above freezing point.

    PubMed

    Nang, C F; Osman, K; Budin, S B; Ismail, M I; Jaffar, F H F; Mohamad, S F S; Ibrahim, S F

    2012-05-01

    Liquid nitrogen preservation in remote farms is a limitation. The goal of this study was to determine optimum temperature above freezing point for bovine spermatozoa preservation using bovine serum albumin (BSA) as a supplementation. Pooled semen sample from three ejaculates was subjected to various BSA concentration (1, 4, 8 and 12 mg ml(-1)), before incubation in different above freezing point temperatures (4, 25 and 37 °C). Viability assessment was carried out against time from day 0 (fresh sample) until all spermatozoa become nonviable. Optimal condition for bovine spermatozoa storage was at 4 °C with 1 mg ml(-1) BSA for almost 7 days. BSA improved bovine spermatozoa viability declining rate to 44.28% at day 4 and 57.59% at day 7 compared to control, with 80.54% and 98.57% at day 4 and 7 respectively. Increase in BSA concentration did not improve sperm viability. Our results also confirmed that there was a strong negative correlation between media osmolarity and bovine spermatozoa survival rate with r = 0.885, P < 0.0001. Bovine serum albumin helps to improve survival rate of bovine spermatozoa stored above freezing point.

  20. Tear film osmolarity and dry eye disease: a review of the literature

    PubMed Central

    Potvin, Richard; Makari, Sarah; Rapuano, Christopher J

    2015-01-01

    Objective To evaluate the evidence in the peer-reviewed literature regarding the use of tear osmolarity as a physiological marker to diagnose, grade severity, and track therapeutic response in dry eye disease (DED). In addition, to review the evidence for the role of tear osmolarity in the pathophysiology of DED and ocular surface disease. Methods A literature review of all publications after the year 2000, which included the keywords “tear osmolarity”, was conducted. Relevant articles were graded according to quality of evidence and research, using the University of Michigan Practice Guideline and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) rating systems. Articles were further categorized by the nature of any reported financial support and by the overall impression they provided related to tear osmolarity. Results A total of 164 articles were identified as relevant to the search criteria, although some were editorials, and some were written in a foreign language. Of the total, it was possible to grade 159, and an overall impression was generated for 163. A positive impression of tear osmolarity in DED diagnosis was evident in 72% (117/163) of all articles, with a neutral impression in a further 21% (35/163); 7% had a negative impression. The percentage of positive impressions appeared independent of the quality of research; 73% (38/52) of articles graded high/moderate quality supported the use of tear film osmolarity measurement in DED diagnosis. Impressions were also independent of the source of financial support, with 72% (75/104) of independent studies positive. Conclusion The literature broadly supports the use of tear film osmolarity as an objective numerical measure for diagnosing, grading severity, and managing treatment of DED. PMID:26586933

  1. Renal Safety of Iodinated Contrast Media Depending on Their Osmolarity – Current Outlooks

    PubMed Central

    Mruk, Bartosz

    2016-01-01

    Summary Iodinated contrast media (ICM) are commonly administered pharmaceutical agents. Most often they are used intravenously and intraarterially. Although iodinated contrast agents are relatively safe and widely used, adverse events occur and questions remain about their use, safety, and interactions. The most important adverse effects of contrast media include hypersensitivity reactions, thyroid dysfunction, and contrast-induced nephropathy. Radiologists must be aware of the risk factors for reactions to contrast media. Nonionic iodinated contrast agents can be divided into monomeric, low-osmolar, and dimeric, iso-osmolar classes. The osmotic characteristics of contrast media have been a significant focus in many investigations of contrast-induced nephropathy. PMID:27141236

  2. Tear Osmolarity and Dry Eye Symptoms in Women Using Oral Contraception and Contact Lenses

    PubMed Central

    Chen, Sarah P.; Massaro-Giordano, Giacomina; Pistilli, Maxwell; Schreiber, Courtney A.; Bunya, Vatinee Y.

    2013-01-01

    Purpose To examine the relationship between oral contraceptive pill (OCP) use, contact lens wear, and dry eye signs and symptoms in healthy young females. Methods Fifty-two women using OCPs and forty-five women not using any form of hormonal contraception were enrolled. Medical, menstrual, and contact lens histories were obtained and dry eye symptoms were assessed using the Ocular Surface Disease Index (OSDI) and Symptom Assessment iN Dry Eye (SANDE) questionnaires. Tear osmolarity testing was performed using the TearLab™ Osmolarity System. Results Mean age of all subjects was 26.0 ± 3.7 years. There were no significant differences in any of the measurements between the follicular and luteal phases. While SANDE scores were significantly higher in subjects with OCP and recent contact lens use (p<0.01), there were no significant differences in OSDI and tear osmolarity amongst the same subject groups. Subjects who reported both OCP and recent contact lens use had significantly higher OSDI and SANDE scores (p=0.015 and p<0.001, respectively). Conclusions There were no differences between the phases of the menstrual cycle. Tear osmolarity was not affected by OCP or contact lens use in young females. However, the combination of OCP use and contact lens wear may increase the severity of dry eye symptoms. PMID:23086364

  3. A Model for the Precorneal Tear Film with Osmolarity and Corneal Supply

    NASA Astrophysics Data System (ADS)

    Braun, R. J.; King-Smith, P. E.

    2010-11-01

    In the human tear film, a thin liquid layer is spread with a blink; it subsequently levels due to surface tension and evaporates more slowly than pure water due to the floating lipid layer. While eventually the tear film almost always ruptures, recent evidence suggests that in some cases supply of fluid from the cornea or conjunctiva may prolong the life of the tear film and prevent the osmolarity (combined concentration of certain salts and sugars) from reaching very large values that can cause irritation and damage. We incorporate osmolarity into a lubrication model for the tear film and study the dynamics of the tear film with osmotic supply from the corneal surface by numerically solving equations for the film thickness and osmolarity. It is treated as a classical osmotic semi-permeable barrier with parameters appropriate to the cornea. The tear film thinning may be slowed by these effects, and in some cases rupture prevented. The value of the osmolarity in regions thinned by evaporation is reduced by osmosis from the underlying surface.

  4. Characterization of the hypo-osmolarity-induced Ca2+ response in cultured rat astrocytes.

    PubMed

    Fischer, R; Schliess, F; Häussinger, D

    1997-05-01

    The influence of astrocyte swelling on the cytosolic free calcium concentration [Ca2+]i was studied at the single cell level. Sudden exposure of normo-osmotically (305 mosmol/l) cultured astrocytes to hypo-osmotic medium induced a biphasic increase in cytosolic calcium with an initial peak followed by a sustained plateau. The response was osmolarity dependent and was maximal at 205 mosmol/l with respect to [Ca2+]i and the percentage of responding cells. Other modes of astrocyte swelling [gradual adjustment of hypo-osmolarity, normo-osmotic exposure of hyper-osmotic (405 mosmol/l) maintained cells] produced a much weaker [Ca2+]i response. Change from 405 to 205 mosmol/l, however, resulted in the entire peak and an increased plateau. Experiments with Ca(2+)-free medium and after pretreatment with BAPTA-AM, thapsigargin, phorbol myristate acetate, or nimodipine revealed that the peak mainly resulted from depletion of intracellular Ca2+ stores, whereas the plateau was probably due to capacitative Ca2+ entry and Ca2+ influx independent of store depletion including a nimodipin-sensitive component. Prior depletion of ryanodine-, bradykinin- or ATP-sensitive stores revealed that the initial hypo-osmolarity-induced Ca(2+)-release was from a Ca2+ pool also affected by ATP and bradykinin, but not by ryanodine. The recent finding, that the hypo-osmolarity-induced [Ca2+]i response was completely maintained if phospholipase C-mediated phosphatidylinositol hydrolysis was blocked, suggests that hypo-osmolarity may exert an inositol (1,4,5) triphosphate-independent access to these stores.

  5. Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity

    PubMed Central

    Iskeleli, Guzin; Karakoc, Yunus; Ozkok, Ahmet; Arici, Ceyhun; Ozcan, Omer; Ipcioglu, Osman

    2013-01-01

    AIM To compare the effects of first and second generation silicone hydrogel (SiH) contact lens wear on tear film osmolarity. METHODS The healthy subjects who have never used contact lenses before were enrolled in the study. Tear film osmolarity values of 16 eyes (group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes (group 2) who wore second generation SiH contact lenses after three months follow-up. RESULTS Before contact lens wear, tear film osmolarity of groups 1 and 2 were 305.02±49.08 milliosmole (mOsm) and 284.66±30.18mOsm, respectively. After three months of contact lens wear, osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2. Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear, the difference was not statistically significant. CONCLUSION Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease. In the current study, there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear, but the difference is not statistically significant. PMID:24195046

  6. Ethanol Metabolism and Osmolarity Modify Behavioral Responses to Ethanol in C. elegans

    PubMed Central

    Alaimo, Joseph T.; Davis, Scott J.; Song, Sam S.; Burnette, Christopher R.; Grotewiel, Mike; Shelton, Keith L.; Pierce-Shimomura, Jonathan T.; Davies, Andrew G.; Bettinger, Jill C.

    2012-01-01

    Background Ethanol is metabolized by a two-step process in which alcohol dehydrogenase (ADH) oxidizes ethanol to acetaldehyde, which is further oxidized to acetate by aldehyde dehydrogenase (ALDH). Although variation in ethanol metabolism in humans strongly influences the propensity to chronically abuse alcohol, few data exist on the behavioral effects of altered ethanol metabolism. Here, we used the nematode C. elegans to directly examine how changes in ethanol metabolism alter behavioral responses to alcohol during an acute exposure. Additionally, we investigated ethanol solution osmolarity as a potential explanation for contrasting published data on C. elegans ethanol sensitivity. Methods We developed a gas chromatography assay and validated a spectrophotometric method to measure internal ethanol in ethanol-exposed worms. Further, we tested the effects of mutations in ADH and ALDH genes on ethanol tissue accumulation and behavioral sensitivity to the drug. Finally, we tested the effects of ethanol solution osmolarity on behavioral responses and tissue ethanol accumulation. Results Only a small amount of exogenously applied ethanol accumulated in the tissues of C. elegans and consequently their tissue concentrations were similar to those that intoxicate humans. Independent inactivation of an ADH-encoding gene (sodh-1) or an ALDH-encoding gene (alh-6 or alh-13) increased the ethanol concentration in worms and caused hypersensitivity to the acute sedative effects of ethanol on locomotion. We also found that the sensitivity to the depressive effects of ethanol on locomotion is strongly influenced by the osmolarity of the exogenous ethanol solution. Conclusions Our results indicate that ethanol metabolism via ADH and ALDH has a statistically discernable but surprisingly minor influence on ethanol sedation and internal ethanol accumulation in worms. In contrast, the osmolarity of the medium in which ethanol is delivered to the animals has a more substantial effect on

  7. Dependence of tissue optical properties on solute-induced changes in refractive index and osmolarity

    NASA Astrophysics Data System (ADS)

    Liu, Hanli; Beauvoit, Bertrand; Kimura, Mika; Chance, Britton

    1996-04-01

    Additions of a solute/carbohydrate in tissue affect the size of tissue cells and the refractive indexes of the extra- and intracellular fluids, and thus the overall tissue scattering properties. We use both the Rayleigh-Gans and Mie theory approximation in calculating effects of the osmolarity and refractive indexes on the reduced scattering coefficient of tissue, and employ photon diffusion theory to associate the reduced scattering coefficient to the mean optical path length. The calculations show that changes of scattering in tissue depend not only on the change in extracellular refractive index but also on the change in osmolarity, and thus on the change in cell size and volume fraction. Experimentally, we have utilized time-domain and frequency- domain NIR techniques to measure the changes of optical properties caused by an addition of a solute in tissue models and in perfused rat livers. The temperature-dependent path length measurement of the perfused liver confirms the dependence of tissue scattering on the tissue cell size. The results obtained from the liver with three kinds of carbohydrate perfusion display different scattering aspects and can be well explained by changes in cell size and in extracellular as well as intracellular refractive indexes. The consistency between the theoretical and experimental results confirms the dependence of optical properties in (liver) tissue on both tissue osmolarity and relative refractive indexes between the extracellular and intracellular compartments. This study suggests that the NIR technique is a novel and useful tool for noninvasive, physiological monitoring.

  8. Differentiation of osmotic and secretory diarrhoea by stool carbohydrate and osmolar gap measurements

    PubMed Central

    Castro-Rodriguez, J. A.; Salazar-Lindo, E.; Leon-Barua, R.

    1997-01-01

    

 Clinical features and laboratory tests that determine carbohydrate in faeces were evaluated to determine which was best able to distinguish between osmotic and secretory diarrhoea in infants and children. For this purpose 80 boys aged 3 to 24 months, with acute watery diarrhoea, were studied prospectively. The faecal osmolar gap (FOG) was calculated as: serum osmolarity − [2 × (faecal sodium + potassium concentration)]. Fifty eight patients were classified as having predominantly osmotic diarrhoea (FOG >100 mosmol/l), and 22 as having predominantly secretory diarrhoea (FOG ⩽100 mosmol/l). The two groups were comparable in their clinical features on admission, in the results of blood and urine tests, and in the evolution of their diarrhoeal illness. Evidence of steatorrhoea (by positive Sudan III test) and of acid faecal pH on admission were significantly more frequent in patients with osmotic diarrhoea. Mean (SD) faecal osmolarity was not significantly different between the two groups (319 (80) mosmol/l in secretory diarrhoea v 361 (123) mosmol/l in osmotic diarrhoea). Tests for reducing substances in faeces such as Benedict's test—with and without hydrolysis—and glucose strip, all showed a positive and significant association with osmotic diarrhoea (p <0.05, <0.025, <0.05, respectively). The presence of excess reducing substances (Benedict's test with hydrolysis >++) on admission was the most sensitive and specific test with the best predictive value for differentiating between the two types of watery diarrhoea.

 PMID:9370895

  9. Effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 expression in juvenile chinese shrimp, Fenneropenaeus chinensis

    NASA Astrophysics Data System (ADS)

    Ding, Sen; Wang, Fang; Sun, Hao; Guo, Biao; Dong, Shuanglin

    2009-03-01

    Experiments were conducted to examine the effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 of Chinese shrimp Fenneropenaeus chinensis with initial wet body weight of 1.460 g ± 0.091 g. The salinity in the control group (D0) was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8 d, respectively, decreased abruptly to salinity 24, lasted for another 2 d, and then was raised to its initial value 28. This was a complete salinity fluctuation cycle that afterwards repeated itself. After 32 days, the osmolarity in treatments D2, D4, D6 and D8 was significantly lower than that in treatment D0 ( P<0.05). There were significant differences in both muscle and eyestalks HSP70 expression among groups. The HSP70 expressions in muscle and eyestalks in group D4 were 61.4% and 57.0% higher, respectively, than that in the control group D0 ( P<0.05). There were, however, no significant differences in gill or hepatopancreas Na+-K+-ATPase activity between the treatments and the control.

  10. Osmotic control of luminescence and growth in Photobacterium leiognathi from ponyfish light organs.

    PubMed

    Dunlap, P V

    1985-02-01

    Osmolarity was found to control the luminescence and growth of Photobacterium leiognathi strain LN-1a isolated from the light organ of the ponyfish Leiognathus nuchalis (family Leiognathidae). Low osmolarity (ca. 400 mOsm) stimulated luminescence per cell 80 to 100-fold to a level (ca. 2.0 X 10(4) quanta . s-1 . cell-1) equal to that of bacteria taken directly from the light organ and increased the level of luciferase per cell 8 to 10-fold compared to high osmolarity (ca. 800 mOsm). Conversely, high osmolarity stimulated oxygen uptake and growth rate 2 to 4-fold compared to low osmolarity. Of 21 additional tested strains of P. leiognathi from light organs of 9 other ponyfish species, all responded similarly. Low osmolarity may be a host control factor that functions to stimulate the luminescence and restrict the growth of ponyfish light organ bacteria in situ.

  11. Estimating the Osmolarities of Tears During Evaporation Through the “Eyes” of the Corneal Nerves

    PubMed Central

    Hirata, Harumitsu; Mizerska, Kamila; Dallacasagrande, Valentina; Rosenblatt, Mark I.

    2017-01-01

    Purpose A population of corneal neurons in rats preferentially sense and monitor the hyperosmolar conditions of tears when the tears begin to evaporate during corneal dryness. The present study exploited this ability in an effort to estimate tear osmolarities by comparing the responses to corneal dryness to their responses to hyperosmolar stimuli. Methods Extracellular recordings were performed from single neurons in the trigeminal ganglia innervating the corneas of rats. To determine the extent to which the corneal neurons' responses to drying of the cornea were induced via the activation by hyperosmolar stimuli, we assessed the responses to ocular instillation of 500 and 600 mOsm/L, and a graded series of hyperosmolar stimuli ranging from 350 to 1000 mOsm/L. Results The magnitudes of the responses to drying of the cornea were matched almost exactly to those induced by the ocular instillation of the 600 mOsm/L stimuli but not the 500 mOsm/L solutions. The response magnitudes to a graded series of hyperosmolar solutions were nearly linear from the 350 to the 600 mOsm/L stimuli, but reached a plateau or declined slightly thereafter. Conclusions Our results demonstrate that the tear osmolarity in rats could reach 600 to 1000 mOsm/L during ocular dryness. Furthermore, a spontaneous eye blink could be generated at a tear osmolarity of approximately 400 mOsm/L if the blink is solely determined by hyperosmolar tears, but ocular surface cooling also can become a major factor if hyperosmolar tears occurring during ocular dryness lower the threshold of activation of the neurons. PMID:28114576

  12. Cerebrospinal fluid control of neurogenesis induced by retinoic acid during early brain development.

    PubMed

    Alonso, M I; Martín, C; Carnicero, E; Bueno, D; Gato, A

    2011-07-01

    Embryonic-cerebrospinal fluid (E-CSF) plays crucial roles in early brain development including the control of neurogenesis. Although FGF2 and lipoproteins present in the E-CSF have previously been shown to be involved in neurogenesis, the main factor triggering this process remains unknown. E-CSF contains all-trans-retinol and retinol-binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis inducer. In early chick embryo brain, only the mesencephalic-rombencephalic isthmus (IsO) is able to synthesize RA. Here we show that in chick embryo brain development: (1) E-CSF helps to control RA synthesis in the IsO by means of the RBP and all-trans-retinol it contains; (2) E-CSF has retinoic acid activity, which suggests it may act as a diffusion pathway for RA; and (3) the influence of E-CSF on embryonic brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to understand neurogenesis from neural progenitor cells.

  13. Assessment of dry eye in a GVHD murine model: Approximation through tear osmolarity measurement.

    PubMed

    Martínez-Carrasco, Rafael; Sánchez-Abarca, Luis Ignacio; Nieto-Gómez, Cristina; García, Elisabet Martín; Ramos, Teresa L; Velasco, Almudena; Sánchez-Guijo, Fermín; Aijón, José; Hernández-Galilea, Emiliano

    2017-01-01

    Dry eye disease is one of the most frequent pathological events that take place in the course of the graft versus host disease (GVHD), and is the main cause of deterioration in quality of life for patients. Thus, demonstration of dry eye signs in murine models of oGVHD is crucial for the validation of these models for the study of the disease. Given the increasing evidence that tear osmolarity is an important player of dry eye disease, our purpose in this study was to validate the use of a reliable method to assess tear osmolarity in mice: the electrical impedance method. Then, we wanted to test its utility with an oGVHD model. Tear volume assessment was also performed, using the phenol red thread test. We found differences in tear osmolarity in mice that received a transplant with cells from bone marrow and spleen (the GVHD group) when compared with mice that only received bone marrow cells (the BM group) at day 7 (362 ± 8 mOsm/l and 345 ± 9 mOsm/l respectively; P < 0.01) and day 21 (348 ± 19 mOsm/l vs. 326 ± 15 mOsm/l; P < 0.05). We found also differences in tear volume at day 14 (2.30 ± 0.61 mm in oGVHD group and 2.89 ± 0.62 mm in BM group; P = 0.06) and at day 21 (2.10 ± 0.30 mm in oGVHD group and 2.89 ± 0.32 mm in BM group; P < 0.01). Besides this, we observed reduction in epithelial thickness between the GVHD and BM groups (37.0 ± 6.2 μm and 43.6 ± 3.3 μm respectively; P < 0.05). These data show the usefulness of the electrical impedance method to measure tear osmolarity in mice. We can also conclude that this oGVHD model mimics the tear film alterations found in human dry eye disease, what contributes to give relevance to this model for the study of GVHD.

  14. Increased osmolarity with low molecular weight solutes inhibits CTL-mediated cytotoxicity

    SciTech Connect

    Howcroft, T.K.; Lindquist, R.R.

    1986-03-01

    Sucrose induced hyperosmolarity, which has no effect on complement-mediated lysis, was examined for its effect on CTL-mediated cell lysis. Sucrose (0.15M) inhibited H-2/sup b/ anti-H-2/sup d/ PEL specific lysis, as measured by /sup 51/Cr-release, 82.7% (52 +/-1.4 vs. 9 +/- 0.6). The effect of sucrose on the killer cell independent phase was investigated by allowing the killers and targets to interact for 10 minutes at 37/sup 0/C, and then inactivating the killers by a 5 minute incubation at 44/sup 0/C before adjusting the osmolarity. Under these conditions killing was reduced 65.5% (58 +/- 0.5 vs. 20 +/- 0.8) when hit P815 target cells were incubated in 0.15M sucrose; thus indicating inhibition was at the level of the target cell. This effect was not limited to sucrose as Na/sub 2/SO/sub 4/ (.08M) also inhibited /sup 51/Cr-release. Nuclear fragmentation as indicated by release of incorporated /sup 3/H-thymidine also was inhibited in the presence of high osmolarity, although to a lesser extent, 34% (47 +/- 1.6 vs 31 +/- 0.6) after 40 minutes. These data suggest a surprising difference between poly C9 and CTL polyperforins, in light of their reported homologies.

  15. Treatment of Acidified Blood Using Reduced Osmolarity Mixed-Base Solutions

    PubMed Central

    Mason, Thomas G.; Kraut, Jeffrey A.

    2016-01-01

    We hypothesize that reduced osmolarity mixed-base (ROMB) solutions can potentially serve as customizable treatments for acidoses, going beyond standard solutions in clinical use, such as 1.0 M sodium bicarbonate. Through in silico quantitative modeling, by treating acidified canine blood using ROMB solutions, and by performing blood-gas and optical microscopy measurements in vitro, we demonstrate that ROMB solutions having a high proportion of a strong base, such as disodium carbonate or sodium hydroxide, can be effective in reducing carbon dioxide pressure PCO2 while raising pH and bicarbonate ion concentration without causing significant osmotic damage to red blood cells, which can occur during rapid administration of hypertonic solutions of weak bases. These results suggest that a ROMB solution, which is composed mostly of a strong base, could be administered in a safe and effective manner, when compared to a hypertonic solution of sodium bicarbonate. Because of the reduced osmolarity and the customizable content of strong base in ROMB solutions, this approach differs from prior approaches involving hypertonic solutions that only considered a single molar ratio of strong to weak base. Our calculations and measurements suggest that custom-tailored ROMB solutions merit consideration as potentially efficacious treatments for specific types of acidosis, particularly acute metabolic acidosis and acute respiratory acidosis. PMID:28082905

  16. Electrolytes, sugar, calories, osmolarity and pH of beverages and coconut water.

    PubMed

    Chavalittamrong, B; Pidatcha, P; Thavisri, U

    1982-09-01

    Oral rehydration has been recommended in patients with diarrhoea to replace fluid loss from the gastrointestinal tract and reduce the need for intravenous therapy. Beverages (i.e. Cola, Sprite etc.) and coconut water may be used as sources of oral fluid when glucose-electrolyte solution is not available. To evaluate the usefulness and effectiveness of these soft drinks, the basic data such as electrolytes, sugar, calories, osmolarity and pH were determined. The electrolytes of the beverages were significantly lower (p less than 0.001) than the coconut water, especially potassium. The osmolarity of the beverages, which were 693 mOsm/l, was significantly higher (p less than 0.001) than the coconut water (288 mOsm/l); pH of the beverages (3.1) was more acidic (p less than 0.001) than the coconut water (5.4). While the sugar content of the beverages, which were 8.7 gm/dl, was significantly higher (p less than 0.001) than the coconut water (1.1 gm/dl). On comparison, all brands of beverages would give more calories than the coconut water however the coconut water would be absorbed more easily than any brand of soft drink beverage.

  17. Comparison of tear osmolarity and ocular comfort between daily disposable contact lenses: hilafilcon B hydrogel versus narafilcon A silicone hydrogel.

    PubMed

    Sarac, Ozge; Gurdal, Canan; Bostancı-Ceran, Basak; Can, Izzet

    2012-06-01

    The aim of this study was to evaluate tear osmolarity and ocular comfort with two different types of hydrogel daily disposable lenses. The right eyes of 15 first-time contact lens users were included in this prospective study. All eyes wore hilafilcon B silicone hydrogel contact lenses for 8 h (group 1). After 1 week without contact lenses, all eyes wore narafilcon A silicone hydrogel contact lenses for 8 h (group 2). Tear osmolarity measurement was performed before and after 4 and 8 h of each contact lens wear. Ocular comfort was assessed after 4 and 8 h of each contact lens wear. In group 1, the mean baseline, 4- and 8-h tear osmolarity values were 293 ± 10.57, 303.00 ± 10.5 mOsm/L (p = 0.023), and 295.0 ± 1.4 mOsm/L (p > 0.05), respectively. In group 2, the mean baseline, 4- and 8-h tear osmolarity values were 294 ± 13.65, 300.9 ± 11.3 mOsm/L (p = 0.007), and 298.80 ± 7.2 mOsm/L (p > 0.05), respectively. In group 1, the mean comfort score was 7.20 ± 0.45 and 8.60 ± 0.45 at 4 and 8 h, respectively (p = 0.038). In group 2, the mean comfort score significantly decreased from 9.80 ± 0.45 to 7.80 ± 0.84 at 4 h (p = 0.039). Both hydrogel and silicone hydrogel daily disposable contact lenses elevated tear osmolarity during 8 h of contact lens wear. The increase in tear osmolarity with both contact lenses was below the cut-off value for dry eye and was not associated with ocular comfort.

  18. Turn-over of the small non-coding RNA RprA in E. coli is influenced by osmolarity.

    PubMed

    Madhugiri, Ramakanth; Basineni, Sobha Rani; Klug, Gabriele

    2010-10-01

    The sRNA RprA is known to activate rpoS translation in E. coli in an osmolarity-dependent manner. We asked whether RprA stability contributes to osmolarity-dependent regulation and how the RNA binding protein Hfq and the major E. coli endonucleases contribute to this turn-over. The study reveals that osmolarity-dependent turn-over of RprA indeed contributes to its osmolarity-dependent abundance. RprA is stabilized by the RNA chaperone Hfq and in absence of Hfq its turn-over is no longer osmolarity-dependent. The stability of the RprA target mRNA rpoS shows a lower extent of osmolarity dependence, which differs from the profile observed for RprA. Thus, the effect of sucrose is specific for individual RNAs. We can attribute a role of the endoribonuclease RNase E in turn-over of RprA and an indirect effect of the endoribonuclease III in vivo. In addition, RprA is stabilized by the presence of rpoS suggesting that hybrid formation with its target may protect it against ribonucleases. In vitro RprA is cleaved by the RNase E containing degradosome and by RNase III and rpoS interferes with RNase III cleavage. We also show that temperature affects the stabilities of the sRNAs binding to rpoS and of rpoS mRNA itself differentially and that higher stability of DsrA with decreasing temperature may contribute to its high abundance at lower temperatures. This study demonstrates that environmental parameters can affect the stability of sRNAs and consequently their abundance.

  19. Increased osmolarity and cell clustering preserve canine notochordal cell phenotype in culture.

    PubMed

    Spillekom, Sandra; Smolders, Lucas A; Grinwis, Guy C M; Arkesteijn, Irene T M; Ito, Keita; Meij, Björn P; Tryfonidou, Marianna A

    2014-08-01

    Degeneration of the intervertebral disc (IVD) is associated with a loss of notochordal cells (NCs) from the nucleus pulposus (NP) and their replacement by chondrocyte-like cells. NCs are known to maintain extracellular matrix quality and stimulate the chondrocyte-like NP cells, making NCs attractive for designing new tissue engineering approaches for IVD regeneration. However, optimal conditions, such as osmolarity and other characteristics of the culture media, for long-term culture of NCs are not known. The purpose of this study was to investigate the effects of different culture media and osmolarity on the physiology of NCs in vitro. NC clusters isolated from canine IVDs were suspended in alginate beads and cultured at 37°C under normoxic conditions for 28 days. Three different culture conditions were investigated; (1) Dulbecco's modified Eagle's medium (DMEM)/F12 (300 mOsm/L), (2) α-MEM (300 mOsm/L), and (3) α-MEM adjusted to 400 mOsm/L to mimic a hyperosmolar environment. NC morphology, expression of genes related to NC markers, matrix production and remodeling, and DNA- and glycosaminoglycan (GAG) analyses were performed on 1, 7, 14, and 28 days in culture. Large, vesicle-containing cells organized in clusters, characterized as NCs, remained present during 28 days for all culture conditions. However, the proportion of the NC clusters decreased over time, whereas the proportion of spindle-shaped cells increased. Gene expression profiling at 7, 14, and 28 days in culture compared to day 1 indicated a initial loss of NC phenotype followed by some recovery of brachyury and aggrecan gene expression after 28 days of culture supporting a potential recovery of NC phenotype. NCs cultured in α-MEM adjusted to 400 mOsm/L showed the highest gene expression of brachyury, cytokeratin 18, and aggrecan, the highest GAG production, and the lowest collagen 1α1 gene expression. In conclusion, NCs cultured in alginate in native cell clusters, partially retained their

  20. Osmolarity and spectrophotometric property of brilliant blue green define the degree of toxicity on retinal pigment epithelial cells exposed to surgical endoilluminator

    PubMed Central

    Balaiya, Sankarathi; Sambhav, Kumar; Cook, William B; Chalam, Kakarla V

    2016-01-01

    Objective To evaluate the effect of varying concentrations of brilliant blue green (BBG) and their different biochemical characteristics on retinal pigment epithelial (RPE) cells under xenon light source illumination at varying distances to identify safe parameters for intraoperative use. Methods Human retinal RPE cells (ARPE-19) were exposed to two concentrations (0.25 and 0.50 mg/mL) of BBG and illuminated with a xenon surgical illuminator at varying distances (10 and 25 mm), intensity levels, and time intervals (1, 5, and 15 minutes). Additionally, the effect of osmolarity was examined by diluting BBG in different concentrations of glucose. Cytotoxicity of BBG and osmolarity effects on cell viability were evaluated using a WST-1 assay. Light absorption and emission characteristic of BBG in different solvents were measured using a plate reader at different wavelengths. Lastly, the activity of caspase-3 was also studied. Results Cell viability of ARPE-19 cells was 77.4%±12.7%, 78.7%±17.0%, and 65.0%±19.7% at 1, 5, and 15 minutes to exposure of high illumination xenon light at 10 mm (P<0.05) compared to controls. At both distances of illumination (10 and 25 mm), similar cell viabilities were seen between 1 and 5 minutes of exposure. However, there was a decline in viability when the illumination was carried out to 15 minutes in all groups (P<0.05). There was no significant reduction in cell viability in presence or absence of xenon light in different osmolar solutions concentrations of glucose (P>0.05). Maximal light absorption of BBG was noted between 540 and 680 nm. Activated caspase-3 level was not significant in both the concentrations of BBG (P>0.05). Conclusion Our findings suggest that BBG at 0.25 mg/mL during vitreoretinal surgery is safe and not toxic to RPE cells up to 5 minutes under focal high illumination (10 mm) and up to 15 minutes under medium diffuse illumination (25 mm). BBG was safe to be mixed with isotonic glucose solution at the

  1. TolC promotes ExPEC biofilm formation and curli production in response to medium osmolarity.

    PubMed

    Hou, Bo; Meng, Xian-Rong; Zhang, Li-Yuan; Tan, Chen; Jin, Hui; Zhou, Rui; Gao, Jian-Feng; Wu, Bin; Li, Zi-Li; Liu, Mei; Chen, Huan-Chun; Bi, Ding-Ren; Li, Shao-Wen

    2014-01-01

    While a high osmolarity medium activates Cpx signaling and causes CpxR to repress csgD expression, and efflux protein TolC protein plays an important role in biofilm formation in Escherichia coli, whether TolC also responds to an osmolarity change to regulate biofilm formation in extraintestinal pathogenic E. coli (ExPEC) remains unknown. In this study, we constructed ΔtolC mutant and complement ExPEC strains to investigate the role of TolC in the retention of biofilm formation and curli production capability under different osmotic conditions. The ΔtolC mutant showed significantly decreased biofilm formation and lost the ability to produce curli fimbriae compared to its parent ExPEC strain PPECC42 when cultured in M9 medium or 1/2 M9 medium of increased osmolarity with NaCl or sucrose at 28°C. However, biofilm formation and curli production levels were restored to wild-type levels in the ΔtolC mutant in 1/2 M9 medium. We propose for the first time that TolC protein is able to form biofilm even under high osmotic stress. Our findings reveal an interplay between the role of TolC in ExPEC biofilm formation and the osmolarity of the surrounding environment, thus providing guidance for the development of a treatment for ExPEC biofilm formation.

  2. Direct and Osmolarity-Dependent Effects of Glycine on Preimplantation Bovine Embryos

    PubMed Central

    Lyons, Sarah M.; Greene, Alison F.; Broeckling, Corey D.; Schoolcraft, William B.; Krisher, Rebecca L.

    2016-01-01

    Concentrations of glycine (Gly) in embryo culture media are often lower (~0.1 mM) than those in oviductal or uterine fluids (≥1.2 mM). The objective of this study was to determine direct and osmolarity-dependent effects of physiological concentrations of Gly on blastocyst formation and hatching, cell allocation to the trophectoderm (TE) and inner cell mass (ICM), and metabolic activity of bovine embryos. In experiment 1, zygotes were cultured with 100 or 120 mM NaCl and 0 or 1 mM Gly for the first 72 h of culture. Blastocyst formation and hatching were improved (P<0.05) when embryos were cultured with 100 compared to 120 mM NaCl. Inclusion of 1 mM Gly improved (P<0.05) blastocyst formation compared to 0 mM Gly, but this effect was only significant (P<0.05) for embryos cultured with 120 mM NaCl, suggesting bovine embryos can utilize Gly as an osmolyte. In experiment 2, embryos were cultured with 0.1, 1.1, 2.1, or 4.1 mM Gly (100 mM NaCl) for the final 96 h of culture. Blastocyst development was not affected (P>0.05) by Gly, but hatching (0.1 mM Gly, 18.2%) was improved (P<0.05) when embryos were cultured with 1.1 (31.4%) or 2.1 (29.4%) mM Gly. Blastocyst, TE, and ICM cell numbers were not affected (P>0.05) by Gly in either experiment. Blastocysts produced alanine, glutamine, pyruvate, and urea and consumed aspartate, but this metabolic profile was not affected (P>0.05) by Gly. In conclusion, Gly (1.0 mM) improves the development of both early and late stage embryos, but beneficial effects are more pronounced for early embryos exposed to elevated osmolarity. PMID:27459477

  3. CpxR/OmpR Interplay Regulates Curli Gene Expression in Response to Osmolarity in Escherichia coli

    PubMed Central

    Jubelin, Gregory; Vianney, Anne; Beloin, Christophe; Ghigo, Jean-Marc; Lazzaroni, Jean-Claude; Lejeune, Philippe; Dorel, Corinne

    2005-01-01

    Curli fibers could be described as a virulence factor able to confer adherence properties to both abiotic and eukaryotic surfaces. The ability to adapt rapidly to changing environmental conditions through signal transduction pathways is crucial for the growth and pathogenicity of bacteria. OmpR was shown to activate csgD expression, resulting in curli production. The CpxR regulator was shown to negatively affect curli gene expression when binding to its recognition site that overlaps the csgD OmpR-binding site. This study was undertaken to clarify how the interplay between the two regulatory proteins, OmpR and CpxR, can affect the transcription of the curli gene in response to variation of the medium osmolarity. Band-shift assays with purified CpxR proteins indicate that CpxR binds to the csgD promoter region at multiple sites that are ideally positioned to explain the csg repression activity of CpxR. To understand the physiological meaning of this in vitro molecular phenomenon, we analyzed the effects of an osmolarity shift on the two-component pathway CpxA/CpxR. We establish here that the Cpx pathway is activated at both transcriptional and posttranscriptional levels in response to a high osmolarity medium and that CpxR represses csgD expression in high-salt-content medium, resulting in low curli production. However, csgD repression in response to high sucrose content is not mediated by CpxR but by the global regulatory protein H-NS. Therefore, multiple systems (EnvZ/OmpR, Cpx, Rcs, and H-NS) appear to be involved in sensing environmental osmolarity, leading to sophisticated regulation of the curli genes. PMID:15743952

  4. CpxR/OmpR interplay regulates curli gene expression in response to osmolarity in Escherichia coli.

    PubMed

    Jubelin, Gregory; Vianney, Anne; Beloin, Christophe; Ghigo, Jean-Marc; Lazzaroni, Jean-Claude; Lejeune, Philippe; Dorel, Corinne

    2005-03-01

    Curli fibers could be described as a virulence factor able to confer adherence properties to both abiotic and eukaryotic surfaces. The ability to adapt rapidly to changing environmental conditions through signal transduction pathways is crucial for the growth and pathogenicity of bacteria. OmpR was shown to activate csgD expression, resulting in curli production. The CpxR regulator was shown to negatively affect curli gene expression when binding to its recognition site that overlaps the csgD OmpR-binding site. This study was undertaken to clarify how the interplay between the two regulatory proteins, OmpR and CpxR, can affect the transcription of the curli gene in response to variation of the medium osmolarity. Band-shift assays with purified CpxR proteins indicate that CpxR binds to the csgD promoter region at multiple sites that are ideally positioned to explain the csg repression activity of CpxR. To understand the physiological meaning of this in vitro molecular phenomenon, we analyzed the effects of an osmolarity shift on the two-component pathway CpxA/CpxR. We establish here that the Cpx pathway is activated at both transcriptional and posttranscriptional levels in response to a high osmolarity medium and that CpxR represses csgD expression in high-salt-content medium, resulting in low curli production. However, csgD repression in response to high sucrose content is not mediated by CpxR but by the global regulatory protein H-NS. Therefore, multiple systems (EnvZ/OmpR, Cpx, Rcs, and H-NS) appear to be involved in sensing environmental osmolarity, leading to sophisticated regulation of the curli genes.

  5. Determining equilibrium osmolarity in poly(ethylene glycol)/chondrotin sulfate gels mimicking articular cartilage.

    PubMed

    Sircar, S; Aisenbrey, E; Bryant, S J; Bortz, D M

    2015-01-07

    We present an experimentally guided, multi-phase, multi-species polyelectrolyte gel model to make qualitative predictions on the equilibrium electro-chemical properties of articular cartilage. The mixture theory consists of two different types of polymers: poly(ethylene gylcol) (PEG), chondrotin sulfate (ChS), water (acting as solvent) and several different ions: H(+), Na(+), Cl(-). The polymer chains have covalent cross-links whose effect on the swelling kinetics is modeled via Doi rubber elasticity theory. Numerical studies on equilibrium polymer volume fraction and net osmolarity (difference in the solute concentration across the gel) show a complex interplay between ionic bath concentrations, pH, cross-link fraction and the average charge per monomer. Generally speaking, swelling is aided due to a higher average charge per monomer (or a higher particle fraction of ChS, the charged component of the polymer), low solute concentration in the bath, a high pH or a low cross-link fraction. A peculiar case arises at higher values of cross-link fraction, where it is observed that increasing the average charge per monomer leads to gel deswelling.

  6. Sorbic acid stress activates the Candida glabrata high osmolarity glycerol MAP kinase pathway

    PubMed Central

    Jandric, Zeljkica; Gregori, Christa; Klopf, Eva; Radolf, Martin; Schüller, Christoph

    2013-01-01

    Weak organic acids such as sorbic acid are important food preservatives and powerful fungistatic agents. These compounds accumulate in the cytosol and disturb the cellular pH and energy homeostasis. Candida glabrata is in many aspects similar to Saccharomyces cerevisiae. However, with regard to confrontation to sorbic acid, two of the principal response pathways behave differently in C. glabrata. In yeast, sorbic acid stress causes activation of many genes via the transcription factors Msn2 and Msn4. The C. glabrata homologs CgMsn2 and CgMsn4 are apparently not activated by sorbic acid. In contrast, in C. glabrata the high osmolarity glycerol (HOG) pathway is activated by sorbic acid. Here we show that the MAP kinase of the HOG pathway, CgHog1, becomes phosphorylated and has a function for weak acid stress resistance. Transcript profiling of weak acid treated C. glabrata cells suggests a broad and very similar response pattern of cells lacking CgHog1 compared to wild type which is over lapping with but distinct from S. cerevisiae. The PDR12 gene was the highest induced gene in both species and it required CgHog1 for full expression. Our results support flexibility of the response cues for general stress signaling pathways, even between closely related yeasts, and functional extension of a specific response pathway. PMID:24324463

  7. Computation of the excess glucose and Na deficit of hypo-osmolar hyponatremic hyperglycaemia.

    PubMed

    Bartoli, Ettore; Sainaghi, Pier Paolo; Bergamasco, Luca; Castello, Luigi

    2010-06-01

    Exact computations of glucose accumulation (GA, mM) and Na anions deficit (DeltaNa, mEq) can be obtained in hypo-osmolar hyponatremic hyperglycaemia (HHH), where plasma osmolality (POsm) is lower than normal. In this condition, GA - DeltaNa = POsm x TBW (total body water). GA is given by plasma glucose concentration (PG(1)) times extra-cellular volume (ECV), calculated as TBW - ICV (the known intra-cellular volume). The changes in solute content can then be computed from their concentrations. This model was verified on computer-simulated patients to whom GA was added in variable amounts, lower than those of DeltaNa subtracted, generating known ICV, ECV, PNa(1), and PG(1). True computer-generated values were identical (the correlation coefficient R(2) = 1, p < 0.0001) to those computed from solute concentrations with our formulas. These same calculations were applied to patients with HHH, using exclusively the measured PNa(1) and PG(1) to compute solute and solvent changes. The results were significantly correlated to true data obtained by balance studies (R(2) = 0.89, p < 0.001). The mathematical model correctly computes DeltaNa and GA in HHH, where patients can therefore benefit from accurate replacement strategies.

  8. Actin-myosin network influences morphological response of neuronal cells to altered osmolarity.

    PubMed

    Bober, Brian G; Love, James M; Horton, Steven M; Sitnova, Mariya; Shahamatdar, Sina; Kannan, Ajay; Shah, Sameer B

    2015-04-01

    Acute osmotic fluctuations in the brain occur during a number of clinical conditions and can result in a variety of adverse neurological symptoms. Osmotic perturbation can cause changes in the volumes of intra- and extracellular fluid and, due to the rigidity of the skull, can alter intracranial pressure thus making it difficult to analyze purely osmotic effects in vivo. The present study aims to determine the effects of changes in osmolarity on SH-SY5Y human neuroblastoma cells in vitro, and the role of the actin-myosin network in regulating this response. Cells were exposed to hyper- or hypoosmotic media and morphological and cytoskeletal responses were recorded. Hyperosmotic shock resulted in a drop in cell body volume and planar area, a persisting shape deformation, and increases in cellular translocation. Hypoosmotic shock did not significantly alter planar area, but caused a transient increase in cell body volume and an increase in cellular translocation via the development of small protrusions rich in actin. Disruption of the actin-myosin network with latrunculin and blebbistatin resulted in changes to volume and shape regulation, and a decrease in cellular translocation. In both osmotic perturbations, no apparent disruptions to cytoskeletal integrity were observed by light microscopy. Overall, because osmotically induced changes persisted even after volume regulation occurred, it is possible that osmotic stress may play a larger role in neurological dysfunction than currently believed.

  9. Effect of fluid countermeasures of varying osmolarity on cardiovascular responses to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Davis, John E.

    1989-01-01

    Current operational procedures for shuttle crewmembers include the ingestion of a fluid countermeasure approximately 2 hours before reentry into the earth's gravitational field. The ingestion of the fluid countermeasure is thought to restore plasma volume and improve orthostatic responses upon reentry. The present countermeasure consists of ingesting salt tablets and water to achieve an isotonic solution. It has yet to be determined whether this is the optimal drink to restore orthostatic tolerance. It is also not known whether the drink solution is effective in increasing plasma volume. The purpose here is to evaluate the effectiveness of drink solutions of different osmolarity on restoring plasma volume and orthostatic responses. A hypertonic drink solution was more effective in restoring plasma volume after dehydration than an isotonic solution. However, there were no differences in their effects on an orthostatic challenge. These data suggest that the plasma volume differences produced in this study were not sufficient to produce differences in the cardiovascular responses to an orthostatic challenge, or there are other changes that occur during space flight that are more important in determining orthostatic intolerance.

  10. Effects of osmolarity change on the excitation-contraction coupling of bullfrog ventricle.

    PubMed

    Kawata, H; Kawagoe, K; Tateyama, I

    1974-12-01

    The effect of hyper- and hypotonic solutions on the electrical as well as the mechanical activities of the bullfrog ventricle were investigated. Hypertonic solutions up to 400% tonicity, made by adding sucrose, showed two kinds of inhibitory effect; i.e. a consistent, rapid shortening of the action potential duration and a slowly progressing suppression of contractile tension. The inhibitory effect of the hypertonic solution up to 300%, made by adding NaCl, was more pronounced on the contractile process than on the electrical phenomena. In this condition, the inhibition of the twitch tension occurred with two time constants. The first, rapid decline seems to be related to the suppressive effect on some superficial site while the slower decreasing phase showed a similar time course as the development of contracture. Hypotonic (33.3% and 12.5%) perfusion revealed triphasic changes in the time course of single twitch without accompanying any parallel change in the action potential. From these results it was concluded that the bullfrog ventricular muscle has some superficial site for Ca regulation which is very sensitive to osmolarity change.

  11. A role of ionic strength on the inotropic effects of osmolarity change in frog atrium.

    PubMed

    Ohba, M

    1984-01-01

    The influence of varying the ionic strength of the bathing solution on the contraction of chemically skinned frog atrial muscle fibers was studied. The rate of tension development activated by calcium slows as the ionic strength is elevated. The size of caffeine contracture, however, was larger in the fiber preloaded with calcium at a higher ionic strength. There was a decrease in the maintained tension at 10(-6) M Ca when a fiber was bathed in a high ionic strength solution. Returning to a normal ionic strength solution caused a transient tension increase. When the fiber was bathed in a low ionic strength solution, the maintained tension increased transiently to a high value and then declined to reach a plateau. The response was also observed in a solution of pCa 8. In the caffeine-treated fiber or in the fiber bathed in ATP free solution, although the maintained tension level was changed corresponding to the altered ionic strength, the transient responses were blocked. These responses were not much influenced by the kinds of salts used to change the ionic strength. When osmolarity of the medium was altered by sucrose, transient responses were not induced. The results could qualitatively explain the isometric tension change of an intact fiber of frog atrium bathed in a hyper- or hypotonic solution.

  12. Hyper-osmolarity and calcium chelation: Effects on cystic fibrosis mucus.

    PubMed

    Ermund, Anna; Meiss, Lauren N; Gustafsson, Jenny K; Hansson, Gunnar C

    2015-10-05

    A non-functional Cystic Fibrosis Transmembrane conductance Regulator (CFTR) leads to the disease cystic fibrosis (CF). Although the CFTR is expressed in multiple organs, pulmonary disease is the major cause of illness and death in patients with CF. Stagnant mucus, causing airway obstruction, bacterial overgrowth, persistent inflammation and tissue destruction characterizes the disease, but how the defect in CFTR function is coupled to the mucus phenotype is still controversial. We have recently shown that bicarbonate ions passing through CFTR are necessary for proper unfolding of the MUC2 mucin, thus highlighting the importance of bicarbonate ion transport via the CFTR and the ability of these ions to raise the pH and chelate calcium bound to the mucin as the important steps in forming normal mucus. In order to find potential CF treatments and expand our knowledge about the usefulness of bicarbonate as an active ingredient in formulations to alleviate mucus plugging, we used an Ussing-type chamber and explants from the F508del-CFTR mutant mouse ileum to test the effect of calcium chelators on mucus attachment, either in isolation or in combination with osmolytes such as mannitol or hypertonic saline. We found that increasing the concentration of bicarbonate, both alone or in combination with increased osmolarity of the solution, detached the otherwise attached CF mucus.

  13. High Osmolarity Environments Activate the Mitochondrial Alternative Oxidase in Debaryomyces Hansenii

    PubMed Central

    Garcia-Neto, Wilson; Cabrera-Orefice, Alfredo; Uribe-Carvajal, Salvador; Kowaltowski, Alicia J.; Alberto Luévano-Martínez, Luis

    2017-01-01

    The oleaginous yeast Debaryomyces hansenii is a good model to understand molecular mechanisms involved in halotolerance because of its impressive ability to survive under a wide range of salt concentrations. Several cellular adaptations are implicated in this response, including the presence of a cyanide-insensitive ubiquinol oxidase (Aox). This protein, which is present in several taxonomical orders, has been related to different stress responses. However, little is known about its role in mitochondria during transitions from low to high saline environments. In this report, we analyze the effects of Aox in shifts from low to high salt concentrations in the culture media. At early stages of a salt insult, we observed that this protein prevents the overflow of electrons on the mitochondrial respiratory chain, thus, decreasing the production of reactive oxygen species. Interestingly, in the presence of high osmolite concentrations, Aox activity is able to sustain a stable membrane potential when coupled to complex I, despite a compromised cytochrome pathway. Taken together, our results suggest that under high osmolarity conditions Aox plays a critical role regulating mitochondrial physiology. PMID:28060946

  14. Hyper-osmolarity and calcium chelation: Effects on cystic fibrosis mucus

    PubMed Central

    Ermund, Anna; Meiss, Lauren N.; Gustafsson, Jenny K.; Hansson, Gunnar C.

    2015-01-01

    A non-functional Cystic Fibrosis Transmembrane conductance Regulator (CFTR) leads to the disease cystic fibrosis (CF). Although the CFTR is expressed in multiple organs, pulmonary disease is the major cause of illness and death in patients with CF. Stagnant mucus, causing airway obstruction, bacterial overgrowth, persistent inflammation and tissue destruction characterizes the disease, but how the defect in CFTR function is coupled to the mucus phenotype is still controversial. We have recently shown that bicarbonate ions passing through CFTR are necessary for proper unfolding of the MUC2 mucin, thus highlighting the importance of bicarbonate ion transport via the CFTR and the ability of these ions to raise the pH and chelate calcium bound to the mucin as the important steps in forming normal mucus. In order to find potential CF treatments and expand our knowledge about the usefulness of bicarbonate as an active ingredient in formulations to alleviate mucus plugging, we used an Ussing-type chamber and explants from the F508del-CFTR mutant mouse ileum to test the effect of calcium chelators on mucus attachment, either in isolation or in combination with osmolytes such as mannitol or hypertonic saline. We found that increasing the concentration of bicarbonate, both alone or in combination with increased osmolarity of the solution, detached the otherwise attached CF mucus. PMID:26134505

  15. Inhibition of succinic acid production in metabolically engineered Escherichia coli by neutralizing agent, organic acids, and osmolarity.

    PubMed

    Andersson, Christian; Helmerius, Jonas; Hodge, David; Berglund, Kris A; Rova, Ulrika

    2009-01-01

    The economical viability of biochemical succinic acid production is a result of many processing parameters including final succinic acid concentration, recovery of succinate, and the volumetric productivity. Maintaining volumetric productivities >2.5 g L(-1) h(-1) is important if production of succinic acid from renewable resources should be competitive. In this work, the effects of organic acids, osmolarity, and neutralizing agent (NH4OH, KOH, NaOH, K2CO3, and Na2CO3), and Na2CO3) on the fermentative succinic acid production by Escherichia coli AFP184 were investigated. The highest concentration of succinic acid, 77 g L(-1), was obtained with Na2CO3. In general, irrespective of the base used, succinic acid productivity per viable cell was significantly reduced as the concentration of the produced acid increased. Increased osmolarity resulting from base addition during succinate production only marginally affected the productivity per viable cell. Addition of the osmoprotectant glycine betaine to cultures resulted in an increased aerobic growth rate and anaerobic glucose consumption rate, but decreased succinic acid yield. When using NH4OH productivity completely ceased at a succinic acid concentration of approximately 40 g L(-1). Volumetric productivities remained at 2.5 g L(-1) h(-1) for up to 10 h longer when K- or Na-bases where used instead of NH4OH. The decrease in cellular succinic acid productivity observed during the anaerobic phase was found to be due to increased organic acid concentrations rather than medium osmolarity.

  16. Activation of the Saccharomyces cerevisiae filamentation/invasion pathway by osmotic stress in high-osmolarity glycogen pathway mutants

    NASA Technical Reports Server (NTRS)

    Davenport, K. D.; Williams, K. E.; Ullmann, B. D.; Gustin, M. C.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    Mitogen-activated protein kinase (MAPK) cascades are frequently used signal transduction mechanisms in eukaryotes. Of the five MAPK cascades in Saccharomyces cerevisiae, the high-osmolarity glycerol response (HOG) pathway functions to sense and respond to hypertonic stress. We utilized a partial loss-of-function mutant in the HOG pathway, pbs2-3, in a high-copy suppressor screen to identify proteins that modulate growth on high-osmolarity media. Three high-copy suppressors of pbs2-3 osmosensitivity were identified: MSG5, CAK1, and TRX1. Msg5p is a dual-specificity phosphatase that was previously demonstrated to dephosphorylate MAPKs in yeast. Deletions of the putative MAPK targets of Msg5p revealed that kss1delta could suppress the osmosensitivity of pbs2-3. Kss1p is phosphorylated in response to hyperosmotic shock in a pbs2-3 strain, but not in a wild-type strain nor in a pbs2-3 strain overexpressing MSG5. Both TEC1 and FRE::lacZ expressions are activated in strains lacking a functional HOG pathway during osmotic stress in a filamentation/invasion-pathway-dependent manner. Additionally, the cellular projections formed by a pbs2-3 mutant on high osmolarity are absent in strains lacking KSS1 or STE7. These data suggest that the loss of filamentation/invasion pathway repression contributes to the HOG mutant phenotype.

  17. Diagnostic accuracy of calculated serum osmolarity to predict dehydration in older people: adding value to pathology laboratory reports

    PubMed Central

    Hooper, Lee; Abdelhamid, Asmaa; Ali, Adam; Bunn, Diane K; Jennings, Amy; John, W Garry; Kerry, Susan; Lindner, Gregor; Pfortmueller, Carmen A; Sjöstrand, Fredrik; Walsh, Neil P; Fairweather-Tait, Susan J; Potter, John F; Hunter, Paul R; Shepstone, Lee

    2015-01-01

    Objectives To assess which osmolarity equation best predicts directly measured serum/plasma osmolality and whether its use could add value to routine blood test results through screening for dehydration in older people. Design Diagnostic accuracy study. Participants Older people (≥65 years) in 5 cohorts: Dietary Strategies for Healthy Ageing in Europe (NU-AGE, living in the community), Dehydration Recognition In our Elders (DRIE, living in residential care), Fortes (admitted to acute medical care), Sjöstrand (emergency room) or Pfortmueller cohorts (hospitalised with liver cirrhosis). Reference standard for hydration status Directly measured serum/plasma osmolality: current dehydration (serum osmolality >300 mOsm/kg), impending/current dehydration (≥295 mOsm/kg). Index tests 39 osmolarity equations calculated using serum indices from the same blood draw as directly measured osmolality. Results Across 5 cohorts 595 older people were included, of whom 19% were dehydrated (directly measured osmolality >300 mOsm/kg). Of 39 osmolarity equations, 5 showed reasonable agreement with directly measured osmolality and 3 had good predictive accuracy in subgroups with diabetes and poor renal function. Two equations were characterised by narrower limits of agreement, low levels of differential bias and good diagnostic accuracy in receiver operating characteristic plots (areas under the curve >0.8). The best equation was osmolarity=1.86×(Na++ K+)+1.15×glucose+urea+14 (all measured in mmol/L). It appeared useful in people aged ≥65 years with and without diabetes, poor renal function, dehydration, in men and women, with a range of ages, health, cognitive and functional status. Conclusions Some commonly used osmolarity equations work poorly, and should not be used. Given costs and prevalence of dehydration in older people we suggest use of the best formula by pathology laboratories using a cutpoint of 295 mOsm/L (sensitivity 85%, specificity 59%), to report

  18. Agents that activate the High Osmolarity Glycerol pathway as a means to combat pathogenic molds.

    PubMed

    Wiedemann, Annegret; Spadinger, Anja; Löwe, Axel; Seeger, Allison; Ebel, Frank

    2016-12-01

    Treatment of invasive fungal infections often fails due to the limited number of therapeutic options. In this study, we have analyzed the impact of agents activating the High Osmolarity Glycerol (HOG) pathway on molds that cause infections in humans and livestock. We found that agents like fludioxonil and iprodione, have a clear anti-fungal activity against pathogenic Aspergillus, Lichtheimia, Rhizopus and Scedosporium species. Only A. terreus turned out to be resistant to fludioxonil, even though it is sensitive to iprodione and able to adapt to hyperosmotic conditions. Moreover, the A. terreus tcsC gene can fully complement an A. fumigatus ΔtcsC mutant, thereby also restoring its sensitivity to fludioxonil. The particular phenotype of A. terreus is therefore likely to be independent of its TcsC kinase. In a second part of this study, we further explored the impact of fludioxonil using A. fumigatus as a model organism. When applied in concentrations of 1-2μg/ml, fludioxonil causes an immediate growth arrest and, after longer exposure, a quantitative killing. Hyphae respond to fludioxonil by the formation of new septa and closure of nearly all septal pores. Mitosis occurs in all compartments and is accompanied by a re-localization of the NimA kinase to the cytoplasm. In the swollen compartments, the massive extension of the cell wall triggers a substantial reorganization resulting in an enhanced incorporation of chitin and, most strikingly, a massive loss of galactomannan. Hence, HOG-activating agents have dramatic cell biological consequences and may represent a valuable, future element in the armory that can be used to combat mold infections.

  19. Volume changes and whole cell membrane currents activated during gradual osmolarity decrease in C6 glioma cells: contribution of two types of K+ channels.

    PubMed

    Ordaz, B; Vaca, L; Franco, R; Pasantes-Morales, H

    2004-06-01

    Volume changes and whole cell ionic currents activated by gradual osmolarity reductions (GOR) of 1.8 mosM/min were characterized in C6 glioma cells. Cells swell less in GOR than after sudden osmolarity reductions (SOR), the extent of swelling being partly Ca(2+) dependent. In nominally Ca(2+)-free conditions, GOR activated predominantly whole cell outward currents. Cells depolarized from the initial -79 mV to a steady state of -54 mV reached at 18% osmolarity reduction [hyposmolarity of -18% (H-18%)]. Recordings of Cl(-) and K(+) currents showed activation at H-3% of an outwardly rectifying Cl(-) current, with conductance of 1.6 nS, sensitive to niflumic acid and 5-nitro-2-(3-phenylpropylamino)benzoic acid, followed at H-18% by an outwardly rectifying K(+) current with conductance of 4.1 nS, inhibited by clofilium but insensitive to the typical K(+) channel blockers. With 200 nM Ca(2+) in the patch pipette, whole cell currents activated at H-3% and at H-13% cells depolarized from -77 to -63 mV. A K(+) current activated at H-1%, showing a rapid increase in conductance, suppressed by charybdotoxin and insensitive to clofilium. These results show the operation of two different K(+) channels in response to GOR in the same cell type, activated by Ca(2+) and osmolarity and with different osmolarity activation thresholds. Taurine and glutamate efflux, monitored by labeled tracers, showed delayed osmolarity thresholds of H-39 and H-33%, respectively. This observation clearly separates the Cl(-) and amino acid osmosensitive pathways. The delayed amino acid efflux may contribute to counteract swelling at more stringent osmolarity reductions.

  20. Heat shock protein (Hsp70) induced by a mild heat shock slightly moderates plasma osmolarity increases upon salinity transfer in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Niu, C J; Rummer, J L; Brauner, C J; Schulte, P M

    2008-11-01

    We have investigated whether mild heat shock, and resulting Hsp70 expression, can confer cross-protection against the stress associated with transfer from freshwater (FW) to seawater (SW) in juvenile rainbow trout (Oncorhynchus mykiss). In experimental Series I, juvenile trout reared in FW were transferred from 13.5 degrees C to 25.5 degrees C in FW, held for 2 h, returned to 13.5 degrees C for 12 h, and then transferred to 32 ppt SW at 13.5 degrees C. Branchial Hsp70 increased approximately 10-fold in the heat-shocked fish relative to the control by the end of recovery and remained high 2, 8, and 24 h post-salinity transfer. However, no clear differences could be detected in blood parameters (blood hemoglobin, hematocrit, MCHC, plasma Na(+) and plasma osmolarity) or muscle water content between heat-shocked and sham-shocked fish in SW at any sampling interval (0, 2, 8, 24, 48, 120, 240 and 360 h post-SW transfer). In experimental Series II, trout acclimated to 8 degrees C were heat-shocked at 22 degrees C for 2 h, allowed to recover 18 h, and exposed to a more severe salinity transfer (either 36 or 45 ppt) than in Series I. Branchial Hsp70 levels increased approximately 6-fold in heat-shocked fish, but had declined to baseline after 120 h in SW. Plasma osmolarity and chloride increased in both groups upon transfer to 36 ppt; however, the increase was significantly less in heat-shocked fish when compared to the increase observed in sham-shocked fish at 24 h. No significant differences could be detected in branchial Na(+)/K(+)-ATPase activity or Na(+)/K(+)-ATPase alpha1a and alpha1b mRNA expression between the two groups. Our data indicate that a mild temperature shock has only modest effects on the ability of rainbow trout to resist osmotic stress during FW to SW transfer.

  1. The Extracellular Domain of the Saccharomyces cerevisiae Sln1p Membrane Osmolarity Sensor Is Necessary for Kinase Activity

    PubMed Central

    Ostrander, Darin B.; Gorman, Jessica A.

    1999-01-01

    The function of the extracellular domain (ECD) of Sln1p, a plasma membrane two-transmembrane domain (TMD) sensor of the high-osmolarity glycerol (HOG) response pathway, has been studied in the yeast Saccharomyces cerevisiae. Truncations of SLN1 that retain an intact kinase domain are capable of complementing the lethality of an sln1Δ strain. By observing levels of Hog1p phosphorylation as well as the phosphorylation state of Sln1p, the kinase activities of various SLN1 constructions were determined. In derivatives that do not contain the first TMD, Sln1p activity was no longer dependent on medium osmolarity but appeared to be constitutively active even under conditions of high osmolarity. Removal of the first TMD (ΔTMD1 construct) gave a protein that was strongly phosphorylated whereas Hog1p was largely dephosphorylated, as expected if the active form of Sln1p is phosphorylated. When both TMDs as well as the ECD were deleted, so that the kinase domain is cytosolic, Sln1p was not phosphorylated whereas Hog1p became constitutively hyperphosphorylated. Surprisingly, this hyperactivity of the HOG mitogen-activated protein kinase signaling pathway was not sufficient to result in cell lethality. When the ECD of the ΔTMD1 construct was replaced with a leucine zipper motif, Sln1p was hyperactive, so that Hog1p became mostly unphosphorylated. In contrast, when the Sln1p/leucine zipper construct was crippled by a mutation of one of the internal leucines, the Sln1 kinase was inactive. These experiments are consistent with the hypothesis that the ECD of Sln1p functions as a dimerization and activation domain but that osmotic regulation of activity requires the presence of the first TMD. PMID:10198019

  2. Increased Serum Sodium and Serum Osmolarity Are Independent Risk Factors for Developing Chronic Kidney Disease; 5 Year Cohort Study

    PubMed Central

    Kuwabara, Masanari; Hisatome, Ichiro; Roncal-Jimenez, Carlos A.; Niwa, Koichiro; Andres-Hernando, Ana; Jensen, Thomas; Bjornstad, Petter; Milagres, Tamara; Cicerchi, Christina; Song, Zhilin; Garcia, Gabriela; Sánchez-Lozada, Laura G.; Ohno, Minoru; Lanaspa, Miguel A.; Johnson, Richard J.

    2017-01-01

    Background Epidemics of chronic kidney disease (CKD) not due to diabetes mellitus (DM) or hypertension have been observed among individuals working in hot environments in several areas of the world. Experimental models have documented that recurrent heat stress and water restriction can lead to CKD, and the mechanism may be mediated by hyperosmolarity that activates pathways (vasopressin, aldose reductase-fructokinase) that induce renal injury. Here we tested the hypothesis that elevated serum sodium, which reflects serum osmolality, may be an independent risk factor for the development of CKD. Methods This study was a large-scale, single-center, retrospective 5-year cohort study at Center for Preventive Medicine, St. Luke’s International Hospital, Tokyo, Japan, between 2004 and 2009. We analyzed 13,201 subjects who underwent annual medical examination of which 12,041 subjects (age 35 to 85) without DM and/or CKD were enrolled. This analysis evaluated age, sex, body mass index, abdominal circumference, hypertension, dyslipidemia, hyperuricemia, fasting glucose, BUN, serum sodium, potassium, chloride and calculated serum osmolarity. Results Elevated serum sodium was an independent risk factor for development of CKD (OR: 1.03, 95% CI, 1.00–1.07) after adjusted regression analysis with an 18 percent increased risk for every 5 mmol/L change in serum sodium. Calculated serum osmolarity was also an independent risk factor for CKD (OR: 1.04; 95% CI, 1.03–1.05) as was BUN (OR: 1.08; 95% CI, 1.06–1.10) (independent of serum creatinine). Conclusions Elevated serum sodium and calculated serum osmolarity are independent risk factors for developing CKD. This finding supports the role of limiting salt intake and preventing dehydration to reduce risk of CKD. PMID:28081152

  3. Butoxyacetic acid-induced hemolysis of rat red blood cells: effect of external osmolarity and cations.

    PubMed

    Udden, M M; Patton, C S

    2005-03-28

    Hemolysis is the principal toxicity of acute exposure to ethylene glycol monobutyl ether (EGBE) in rats. EGBE itself is not an active hemolytic agent, but its metabolite, butoxyacetic acid (BAA) formed as a result of dehydrogenase activity is a potent hemolysin. Here we address the role of osmolarity and cation composition of the suspending buffers in the mechanism of BAA-induced hemolysis of rat red blood cells in vitro. Rat erythrocytes were protected from BAA-induced cell swelling and hemolysis by the addition of sucrose to the suspending media. Hemolysis and cell swelling were also reduced by replacing external sodium with potassium. When calcium was not present in the suspending medium or when chelated by EGTA, hemolysis was increased after 2 h incubation with 1 mM or 2 mM BAA. Addition of as little as 0.05 mM CaCl(2) reduced hemolysis significantly while the addition of MgCl(2) had no effect. The dose-response relationship between BAA concentration and hemolysis determined in the presence or absence of calcium showed an increased effect of BAA in the absence of calcium. BAA-induced spherocytosis and cell fragmentation were more pronounced in the absence of calcium. The time course of BAA-induced hemolysis in the presence and absence of calcium demonstrated that the effect of calcium is to delay the onset of hemolysis. Increased intracellular calcium as a result of exposure to BAA was verified by atomic absorption spectroscopy. Charybdotoxin, an inhibitor of the calcium activated potassium channel, blocked the protective effect of calcium suggesting that the delay of onset of hemolysis in the presence of calcium is due to potassium loss caused by this channel. We conclude that the mode of action of BAA is to cause a colloid osmotic lysis of the rat red blood cell. Hemolysis requires external sodium and is associated with calcium uptake. Calcium appears to delay the onset of hemolysis. We speculate that: (1) BAA causes sodium and calcium to enter the cell; (2

  4. The inner membrane protein YhiM is necessary for Escherichia coli growth at high temperatures and low osmolarity.

    PubMed

    Anderson, M A; Mann, M D; Evans, M A; Sparks-Thissen, R L

    2017-01-01

    To survive, Escherichia coli must be able to survive in rapidly changing environmental conditions including changes in temperature and osmolarity. We have studied the role of the inner membrane protein YhiM in changing environmental conditions. Our data indicate that YhiM is required for normal growth at 37 and 41 °C but not 21 °C. YhiM-deficient cells grown at high temperatures spend more time in lag phase and stop growing at lower cell densities in comparison with their wild-type counterparts. They also have growth defects in low NaCl medium at 37 °C and do not grow at all at 41 °C. The effects of low NaCl can be rescued by addition of KCl or sucrose to the low salt medium. Finally, YhiM-deficient cells fail to grow in dilute medium at 41 °C. These data suggest that YhiM may be important in protecting the cells from changes in temperature and osmolarity.

  5. Functional role of follicular cells in the generation of osmolarity-dependent Cl- currents in Xenopus follicles.

    PubMed Central

    Arellano, R O; Miledi, R

    1995-01-01

    1. Osmolarity-dependent (osmo-dependent) ionic currents from follicle-enclosed Xenopus oocytes (follicles) were studied using the two-microelectrode voltage-clamp technique, combined with intra-oocyte pressure injection of sucrose or polyethylene glycols (PEGs). 2. Intra-oocyte injections of sucrose or PEG (3-25 nmol) generated inward membrane currents (follicles held at -60 mV) associated with an increase in membrane conductance. These currents were carried mainly by chloride ions (ICl(osm)), and were strongly attenuated by increasing the tonicity of the external medium, or by external application of La3+ (0.1-1 mM). 3. The ability to generate ICl(osm) depended on the molecular weight of the injected PEG. Injections of PEG 200 or 300 generated ICl(osm) in 95% of the follicles tested, PEG 600 generated comparable currents in only 20% of the follicles, while similar injections of PEG 1000 did not elicit ICl(osm). 4. Octanol (1-1.5 mM), a gap junction channel blocker, reversibly inhibited 50-90% of the ICl(osm) generated by injections of sucrose or PEG 300. Moreover, sucrose or PEG injections did not elicit ICl(osm) in defolliculated oocytes. 5. It is concluded that an increase in the internal osmolarity of the follicular cells activates a mechanism, probably involving cellular swelling, which leads to the opening of ICl(osm) channels most probably located in the follicular cell membrane. PMID:8568675

  6. Modification of sodium, glucose, potassium, and osmolarity in packed red blood cells and fresh frozen plasma using a desktop hemoconcentrator setup.

    PubMed

    Striker, Carrie Whittaker; Woldorf, Stacia; Holt, David

    2012-06-01

    Massive transfusion with packed blood cells (PRBCs) or fresh frozen plasma (FFP) can result in dangerous complications including stroke, kidney failure, and cardiac arrest. A simple, bench top technique using a hemoconcentrator and dialysate solution is described to correct critical values of sodium, glucose, potassium, and osmolarity in PRBCs and FFP. Sodium, glucose, and osmolarity were corrected to normal or near normal values. Elevated potassium was reduced by 65%, but not completely normalized. A simple, bench top method for correcting dangerous abnormalities with PRBCs and FFP can be used to improve the safety of massive blood transfusion.

  7. Rectal Application of a Highly Osmolar Personal Lubricant in a Macaque Model Induces Acute Cytotoxicity but Does Not Increase Risk of SHIV Infection

    PubMed Central

    Vishwanathan, Sundaram A.; Morris, Monica R.; Wolitski, Richard J.; Luo, Wei; Rose, Charles E.; Blau, Dianna M.; Tsegaye, Theodros; Zaki, Sherif R.; Garber, David A.; Jenkins, Leecresia T.; Henning, Tara C.; Patton, Dorothy L.; Hendry, R. Michael; McNicholl, Janet M.; Kersh, Ellen N.

    2015-01-01

    Background Personal lubricant use is common during anal intercourse. Some water-based products with high osmolality and low pH can damage genital and rectal tissues, and the polymer polyquaternium 15 (PQ15) can enhance HIV replication in vitro. This has raised concerns that lubricants with such properties may increase STD/HIV infection risk, although in vivo evidence is scarce. We use a macaque model to evaluate rectal cytotoxicity and SHIV infection risk after use of a highly osmolar (>8,000 mOsm/kg) water-based lubricant with pH of 4.4, and containing PQ15. Methods Cytotoxicity was documented by measuring inflammatory cytokines and epithelial tissue sloughing during six weeks of repeated, non-traumatic lubricant or control buffer applications to rectum and anus. We measured susceptibility to SHIVSF162P3 infection by comparing virus doses needed for rectal infection in twenty-one macaques treated with lubricant or control buffer 30 minutes prior to virus exposure. Results Lubricant increased pro-inflammatory cytokines and tissue sloughing while control buffer (phosphate buffered saline; PBS) did not. However, the estimated AID50 (50% animal infectious dose) was not different in lubricant- and control buffer-treated macaques (p = 0.4467; logistic regression models). Conclusions Although the test lubricant caused acute cytotoxicity in rectal tissues, it did not increase susceptibility to infection in this macaque model. Thus neither the lubricant-induced type/extent of inflammation nor the presence of PQ15 affected infection risk. This study constitutes a first step in the in vivo evaluation of lubricants with regards to HIV transmission. PMID:25853710

  8. [Calcium concentrations in the urine of recurrent stone-formers and their controls (author's transl)].

    PubMed

    Leskovar, P; Hartung, R; Siebert, A; Wellnhofer, E

    1980-07-01

    Over a period of 4--6 weeks the urinary concentrations of (total calcium, ionized calcium, creatinine and osmolarity in recurrent stone-formers and healthy controls were measured in morning, midday and evening urine samples. The mean urinary concentrations of the (total) calcium were in both groups the same. However, 31% of the stone-formers and only 18% of the controls showed a mean calcium concentration > 5 mmol/l. The ionized calcium, on the contrary, was significantly higher in the stone-formers than in the controls. The lower urinary osmolarity of the recurrent stone-formers led to significantly higher Ca/osmolarity and Ca2+/osmolarity ratios; analogously, the quotient Ca2+/creatinine was also significantly raised in stone-formers.

  9. Mouse embryos stressed by physiological levels of osmolarity become arrested in the late 2-cell stage before entry into M phase.

    PubMed

    Wang, Fang; Kooistra, Megan; Lee, Martin; Liu, Lin; Baltz, Jay M

    2011-10-01

    Preimplantation mouse embryos of many strains become arrested at the 2-cell stage if the osmolarity of culture medium that normally supports development to blastocysts is raised to approximately that of their normal physiological environment in the oviduct. Arrest can be prevented if molecules that serve as "organic osmolytes" are present in the medium, because organic osmolytes, principally glycine, are accumulated by embryos to provide intracellular osmotic support and regulate cell volume. Medium with an osmolarity of 310 mOsM induced arrest of approximately 80% of CF1 mouse embryos at the 2-cell stage, in contrast to the approximately 100% that progressed beyond the 2-cell stage at 250 or 301 mOsM with glycine. The nature of this arrest induced by physiological levels of osmolarity is unknown. Arrest was reversible by transfer to lower-osmolarity medium at any point during the 2-cell stage, but not after embryos would normally have progressed to the 4-cell stage. Cessation of development likely was not due to apoptosis, as shown by lack of external annexin V binding, detectable cytochrome c release from mitochondria, or nuclear DNA fragmentation. Two-cell embryos cultured at 310 mOsM progressed through the S phase, and zygotic genome activation markers were expressed. However, most embryos failed to initiate the M phase, as evidenced by intact nuclei with decondensed chromosomes, low M-phase promoting factor activity, and an inactive form of CDK1, although a few blastomeres were arrested in metaphase. Thus, embryos become arrested late in the G(2) stage of the second embryonic cell cycle when stressed by physiological osmolarity in the absence of organic osmolytes.

  10. Mouse Embryos Stressed by Physiological Levels of Osmolarity Become Arrested in the Late 2-Cell Stage Before Entry into M Phase1

    PubMed Central

    Wang, Fang; Kooistra, Megan; Lee, Martin; Liu, Lin; Baltz, Jay M.

    2011-01-01

    Preimplantation mouse embryos of many strains become arrested at the 2-cell stage if the osmolarity of culture medium that normally supports development to blastocysts is raised to approximately that of their normal physiological environment in the oviduct. Arrest can be prevented if molecules that serve as “organic osmolytes” are present in the medium, because organic osmolytes, principally glycine, are accumulated by embryos to provide intracellular osmotic support and regulate cell volume. Medium with an osmolarity of 310 mOsM induced arrest of approximately 80% of CF1 mouse embryos at the 2-cell stage, in contrast to the approximately 100% that progressed beyond the 2-cell stage at 250 or 301 mOsM with glycine. The nature of this arrest induced by physiological levels of osmolarity is unknown. Arrest was reversible by transfer to lower-osmolarity medium at any point during the 2-cell stage, but not after embryos would normally have progressed to the 4-cell stage. Cessation of development likely was not due to apoptosis, as shown by lack of external annexin V binding, detectable cytochrome c release from mitochondria, or nuclear DNA fragmentation. Two-cell embryos cultured at 310 mOsM progressed through the S phase, and zygotic genome activation markers were expressed. However, most embryos failed to initiate the M phase, as evidenced by intact nuclei with decondensed chromosomes, low M-phase promoting factor activity, and an inactive form of CDK1, although a few blastomeres were arrested in metaphase. Thus, embryos become arrested late in the G2 stage of the second embryonic cell cycle when stressed by physiological osmolarity in the absence of organic osmolytes. PMID:21697513

  11. Extraction of water labeled with oxygen 15 during single-capillary transit. Influence of blood pressure, osmolarity, and blood-brain barrier damage

    SciTech Connect

    Go, K.G.; Lammertsma, A.A.; Paans, A.M.; Vaalburg, W.; Woldring, M.G.

    1981-09-01

    By external detection, the influence of arterial blood pressure (BP), osmolarity, and cold-induced blood-brain barrier damage was assessed on the extraction of water labeled with oxygen 15 during single-capillary transit in the rat. There was an inverse relation between arterial BP and extraction that was attributable to the influence of arterial BP on cerebral blood flow (CBF) and the relation between CBF and extraction. Neither arterial BP nor osmolarity of the injected bolus had any direct effect on extraction of water 15O, signifying that the diffusional exchange component (determined by blood flow) of extraction greatly surpasses the convection flow contribution by hydrostatic or osmotic forces. Damage to the blood-brain barrier did not change its permeability to water.

  12. A kinetic model for quantitative evaluation of the effect of hydrogen and osmolarity on hydrogen production by Caldicellulosiruptor saccharolyticus

    PubMed Central

    2011-01-01

    Background Caldicellulosiruptor saccharolyticus has attracted increased interest as an industrial hydrogen (H2) producer. The aim of the present study was to develop a kinetic growth model for this extreme thermophile. The model is based on Monod kinetics supplemented with the inhibitory effects of H2 and osmotic pressure, as well as the liquid-to-gas mass transfer of H2. Results Mathematical expressions were developed to enable the simulation of microbial growth, substrate consumption and product formation. The model parameters were determined by fitting them to experimental data. The derived model corresponded well with experimental data from batch fermentations in which the stripping rates and substrate concentrations were varied. The model was used to simulate the inhibition of growth by H2 and solute concentrations, giving a critical dissolved H2 concentration of 2.2 mmol/L and an osmolarity of 0.27 to 29 mol/L. The inhibition by H2, being a function of the dissolved H2 concentration, was demonstrated to be mainly dependent on H2 productivity and mass transfer rate. The latter can be improved by increasing the stripping rate, thereby allowing higher H2 productivity. The experimentally determined degree of oversaturation of dissolved H2 was 12 to 34 times the equilibrium concentration and was comparable to the values given by the model. Conclusions The derived model is the first mechanistically based model for fermentative H2 production and provides useful information to improve the understanding of the growth behavior of C. saccharolyticus. The model can be used to determine optimal operating conditions for H2 production regarding the substrate concentration and the stripping rate. PMID:21914204

  13. A delayed, unusual non-cardiogenic pulmonary edema after intravascular administration of non-ionic, low osmolar radiocontrast media for coronary angiography.

    PubMed

    Kang, Min-Ho; Nah, Jong-Chun

    2013-07-01

    Non-cardiogenic pulmonary edema (NCPE) is a rare adverse reaction to iodinated radiocontrast media (RCM), in which all previous cases were immediate reactions. A 56-year-old male was given iopamidol, a non-ionic, low osmolar RCM, during coronary artery angiography. He developed pulmonary edema and fever a day after the procedure. Despite diuretic therapy, the patient's pulmonary edema worsened and his high fever persisted. The patient's pulmonary edema was eventually resolved with intravenous steroid treatment. We interpreted the patient's condition as NCPE manifesting as a delayed reaction to RCM. To our knowledge, our case is the first to show NCPE as a delayed hypersensitivity reaction.

  14. Incubation temperature, osmolarity, and salicylate affect the expression of resistance-nodulation-division efflux pumps and outer membrane porins in Acinetobacter baumannii ATCC19606T.

    PubMed

    Bazyleu, Andrei; Kumar, Ayush

    2014-08-01

    In this study, we examined the impact of various environmental conditions on the expression of resistance-nodulation-division (RND) efflux pumps and outer membrane (OM) porins, two key determinants of Acinetobacter baumannii's intrinsic resistance, an organism known to cause various multidrug resistant infections in immunocompromised individuals. Quantitative RT-PCR was used to analyze the expression of adeB, adeG, and adeJ (genes encoding RND pumps) and 33 kDa, carO, and oprD (genes encoding OM porins) of A. baumannii ATCC19606(T) under different incubation temperatures (30, 37, and 42 °C) and in the presence of high osmolarity and salicylate. Downregulation of all three RND pumps was observed at 30 °C, while downregulation of all three porins tested was observed at increased osmolarity. Downregulation of RND efflux pumps, particularly AdeABC, was consistent with increased susceptibility to antibiotics that are substrates of this pump. Expression of the adeR response regulator gene of the AdeRS system, the activator of the AdeABC pump, was also analyzed. Our work shows that various environmental stress conditions can influence the expression of RND pumps and porins in A. baumannii ATCC19606(T) and thus may play a role in the modulation of its antibiotic resistance.

  15. Adenylyl cyclase G, an osmosensor controlling germination of Dictyostelium spores.

    PubMed

    van Es, S; Virdy, K J; Pitt, G S; Meima, M; Sands, T W; Devreotes, P N; Cotter, D A; Schaap, P

    1996-09-27

    Dictyostelium cells express a G-protein-coupled adenylyl cyclase, ACA, during aggregation and an atypical adenylyl cyclase, ACG, in mature spores. The ACG gene was disrupted by homologous recombination. acg- cells developed into normal fruiting bodies with viable spores, but spore germination was no longer inhibited by high osmolarity, a fairly universal constraint for spore and seed germination. ACG activity, measured in aca-/ACG cells, was strongly stimulated by high osmolarity with optimal stimulation occurring at 200 milliosmolar. RdeC mutants, which display unrestrained protein kinase A (PKA) activity and a cell line, which overexpresses PKA under a prespore specific promoter, germinate very poorly, both at high and low osmolarity. These data indicate that ACG is an osmosensor controlling spore germination through activation of protein kinase A.

  16. Two-Component Signaling Regulates Osmotic Stress Adaptation via SskA and the High-Osmolarity Glycerol MAPK Pathway in the Human Pathogen Talaromyces marneffei

    PubMed Central

    Cao, Cunwei; Andrianopoulos, Alex

    2016-01-01

    ABSTRACT For successful infection to occur, a pathogen must be able to evade or tolerate the host’s defense systems. This requires the pathogen to first recognize the host environment and then signal this response to elicit a complex adaptive program in order to activate its own defense strategies. In both prokaryotes and eukaryotes, two-component signaling systems are utilized to sense and respond to changes in the external environment. The hybrid histidine kinases (HHKs) at the start of the two-component signaling pathway have been well characterized in human pathogens. However, how these HHKs regulate processes downstream currently remains unclear. This study describes the role of a response regulator downstream of these HHKs, sskA, in Talaromyces marneffei, a dimorphic human pathogen. sskA is required for asexual reproduction, hyphal morphogenesis, cell wall integrity, osmotic adaptation, and the morphogenesis of yeast cells both in vitro at 37°C and during macrophage infection, but not during dimorphic switching. Comparison of the ΔsskA mutant with a strain in which the mitogen-activated protein kinase (MAPK) of the high-osmolarity glycerol pathway (SakA) has been deleted suggests that SskA acts upstream of this pathway in T. marneffei to regulate these morphogenetic processes. This was confirmed by assessing the amount of phosphorylated SakA in the ΔsskA mutant, antifungal resistance due to a lack of SakA activation, and the ability of a constitutively active sakA allele (sakAF316L) to suppress the ΔsskA mutant phenotypes. We conclude that SskA regulates morphogenesis and osmotic stress adaptation in T. marneffei via phosphorylation of the SakA MAPK of the high-osmolarity glycerol pathway. IMPORTANCE This is the first study in a dimorphic fungal pathogen to investigate the role of a response regulator downstream of two-component signaling systems and its connection to the high-osmolarity glycerol pathway. This study will inspire further research into

  17. Salt-sensitivity of σ(H) and Spo0A prevents sporulation of Bacillus subtilis at high osmolarity avoiding death during cellular differentiation.

    PubMed

    Widderich, Nils; Rodrigues, Christopher D A; Commichau, Fabian M; Fischer, Kathleen E; Ramirez-Guadiana, Fernando H; Rudner, David Z; Bremer, Erhard

    2016-04-01

    The spore-forming bacterium Bacillus subtilis frequently experiences high osmolarity as a result of desiccation in the soil. The formation of a highly desiccation-resistant endospore might serve as a logical osmostress escape route when vegetative growth is no longer possible. However, sporulation efficiency drastically decreases concomitant with an increase in the external salinity. Fluorescence microscopy of sporulation-specific promoter fusions to gfp revealed that high salinity blocks entry into the sporulation pathway at a very early stage. Specifically, we show that both Spo0A- and SigH-dependent transcription are impaired. Furthermore, we demonstrate that the association of SigH with core RNA polymerase is reduced under these conditions. Suppressors that modestly increase sporulation efficiency at high salinity map to the coding region of sigH and in the regulatory region of kinA, encoding one the sensor kinases that activates Spo0A. These findings led us to discover that B. subtilis cells that overproduce KinA can bypass the salt-imposed block in sporulation. Importantly, these cells are impaired in the morphological process of engulfment and late forespore gene expression and frequently undergo lysis. Altogether our data indicate that B. subtilis blocks entry into sporulation in high-salinity environments preventing commitment to a developmental program that it cannot complete.

  18. Evidence of a new role for the high-osmolarity glycerol mitogen-activated protein kinase pathway in yeast: regulating adaptation to citric acid stress.

    PubMed

    Lawrence, Clare L; Botting, Catherine H; Antrobus, Robin; Coote, Peter J

    2004-04-01

    Screening the Saccharomyces cerevisiae disruptome, profiling transcripts, and determining changes in protein expression have identified an important new role for the high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway in the regulation of adaptation to citric acid stress. Deletion of HOG1, SSK1, PBS2, PTC2, PTP2, and PTP3 resulted in sensitivity to citric acid. Furthermore, citric acid resulted in the dual phosphorylation, and thus activation, of Hog1p. Despite minor activation of glycerol biosynthesis, the inhibitory effect of citric acid was not due to an osmotic shock. HOG1 negatively regulated the expression of a number of proteins in response to citric acid stress, including Bmh1p. Evidence suggests that BMH1 is induced by citric acid to counteract the effect of amino acid starvation. In addition, deletion of BMH2 rendered cells sensitive to citric acid. Deletion of the transcription factor MSN4, which is known to be regulated by Bmh1p and Hog1p, had a similar effect. HOG1 was also required for citric acid-induced up-regulation of Ssa1p and Eno2p. To counteract the cation chelating activity of citric acid, the plasma membrane Ca(2+) channel, CCH1, and a functional vacuolar membrane H(+)-ATPase were found to be essential for optimal adaptation. Also, the transcriptional regulator CYC8, which mediates glucose derepression, was required for adaptation to citric acid to allow cells to metabolize excess citrate via the tricarboxylic acid (TCA) cycle. Supporting this, Mdh1p and Idh1p, both TCA cycle enzymes, were up-regulated in response to citric acid.

  19. Exposure to low- vs iso-osmolar contrast agents reduces NADPH-dependent reactive oxygen species generation in a cellular model of renal injury.

    PubMed

    Netti, Giuseppe Stefano; Prattichizzo, Clelia; Montemurno, Eustacchio; Simone, Simona; Cafiero, Cesira; Rascio, Federica; Stallone, Giovanni; Ranieri, Elena; Grandaliano, Giuseppe; Gesualdo, Loreto

    2014-03-01

    Contrast-induced nephropathy represents the third cause of hospital-acquired acute renal failure. This study investigated the effects of low- vs iso-osmolar contrast medium (CM) exposure on NADPH-dependent reactive oxygen species (ROS) generation by tubular cells. X-ray attenuation of iohexol, iopamidol, and iodixanol was assessed at equimolar iodine concentrations and their effects on human renal proximal tubular cells (PTCs) were evaluated with equally attenuating solutions of each CM. Cytotoxicity, apoptosis, and necrosis were investigated by trypan blue exclusion, MTT assay, and annexin V/propidium iodide assay, respectively. ROS production was assessed by DCF assay, NADPH oxidase activity by the lucigenin-enhanced chemiluminescence method, and Nox4 expression by immunoblot. Yielding the same X-ray attenuation, CM cytotoxicity was assessed in PTCs at equimolar iodine concentrations. More necrosis was present after incubation with iohexol and iopamidol than after incubation with equal concentrations of iodixanol. Iohexol and iodixanol at low iodine concentrations induced less cytotoxicity than iopamidol. Moreover, both iohexol and iopamidol induced more apoptosis than iodixanol, with a dose-dependent effect. ROS generation was significantly higher with iopamidol and iohexol compared to iodixanol. NADPH oxidase activity and Nox4 protein expression significantly increased after exposure to iopamidol and iohexol, with a dose-dependent effect, compared with iodixanol. CM-induced Nox4 expression and activity depended upon Src activation. In conclusion, at angiographic concentrations, iodixanol induces fewer cytotoxic effects on cultured tubular cells than iohexol and iopamidol along with a lower induction of Nox4-dependent ROS generation. This enzyme may, thus, represent a potential therapeutic target to prevent iodinated CM-related oxidative stress.

  20. Expression of Pseudomonas syringae type III effectors in yeast under stress conditions reveals that HopX1 attenuates activation of the high osmolarity glycerol MAP kinase pathway.

    PubMed

    Salomon, Dor; Bosis, Eran; Dar, Daniel; Nachman, Iftach; Sessa, Guido

    2012-11-01

    The Gram-negative bacterium Pseudomonas syringae pv. tomato (Pst) is the causal agent of speck disease in tomato. Pst pathogenicity depends on a type III secretion system that delivers effector proteins into host cells, where they promote disease by manipulating processes to the advantage of the pathogen. Previous studies identified seven Pst effectors that inhibit growth when expressed in yeast under normal growth conditions, suggesting that they interfere with cellular processes conserved in yeast and plants. We hypothesized that effectors also target conserved cellular processes that are required for yeast growth only under stress conditions. We therefore examined phenotypes induced by expression of Pst effectors in yeast grown in the presence of various stressors. Out of 29 effectors tested, five (HopX1, HopG1, HopT1-1, HopH1 and AvrPtoB) displayed growth inhibition phenotypes only in combination with stress conditions. Viability assays revealed that the HopX1 effector caused loss of cell viability under prolonged osmotic stress. Using transcription reporters, we found that HopX1 attenuated the activation of the high osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway, which is responsible for yeast survival under osmotic stress, while other MAPK pathways were mildly affected by HopX1. Interestingly, HopX1-mediated phenotypes in yeast were dependent on the putative transglutaminase catalytic triad of the effector. This study enlarges the pool of phenotypes available for the functional analysis of Pst type III effectors in yeast, and exemplifies how analysis of phenotypes detected in yeast under stress conditions can lead to the identification of eukaryotic cellular processes affected by bacterial effectors.

  1. Cadmium-induced activation of high osmolarity glycerol pathway through its Sln1 branch is dependent on the MAP kinase kinase kinase Ssk2, but not its paralog Ssk22, in budding yeast.

    PubMed

    Jiang, Linghuo; Cao, Chunlei; Zhang, Lilin; Lin, Wei; Xia, Jing; Xu, Huihui; Zhang, Yan

    2014-12-01

    Cadmium ions disrupt reactive oxygen species/Ca(2+) homeostasis and subsequently elicit cell death and adaptive signaling cascades in eukaryotic cells. Through a functional genomics approach, we have identified deletion mutants of 106 yeast genes, including three MAP kinase genes (HOG1, SLT2, and KSS1), are sensitive to a sublethal concentration of cadmium, and 64 mutants show elevated intracellular cadmium concentrations upon exposure to cadmium. Hog1 is phosphorylated, reaching a peak 30 min after the cadmium treatment. Both Sln1 and Sho1 upstream branches are involved in the cadmium-induced activation of high osmolarity glycerol (HOG) pathway. Cadmium-induced HOG activation is dependent on the MAP kinase kinase kinase Ssk2, but not its paralog Ssk22, in the Sln1 branch.

  2. Expression of neutrophil gelatinase-associated lipocalin in low osmolar contrast-induced nephropathy in rats and the effect of N-acetylcysteine

    PubMed Central

    Li, Wen-Hua; Wang, Lin; He, Hai-Yan; Chen, Jing; Yu, Ya-Ren

    2016-01-01

    Serum creatinine (Scr), which is a conventional indicator of contrast-induced nephropathy (CIN), is unable to reflect the damage of kidney promptly. The present study aimed to investigate the value of neutrophil gelatinase-associated lipocalin (NGAL) in kidney and serum of CIN rats to observe whether NGAL can be used as a superior indicator of CIN. Furthermore, N-acetylcysteine (NAC) was used to assess its effect on CIN. A total of 120 adult male Sprague Dawley rats were randomly divided into four groups (n=30/group): CIN rats (CIN), normal rats treated with NAC (NAC), CIN rats treated with NAC (NAC+CIN) and the control group (CON). Serum Scr and NGAL values were measured at 2, 12, 24, 48 and 72 h following the procedure. Immunohistochemistry and western blot analysis were used to detect NGAL within the kidney tissue. Hematoxylin and eosin staining were used to access the renal injury score. Oxidative stress within the kidney was analyzed via malondialdehyde (MDA) and superoxide dismutase (SOD). The level of NGAL in the serum and tissue of the CIN group increased significantly 2 h after the procedure (P<0.05). However, the Scr value did not exhibit a significantly change until 48 h later. Based on the renal injury scores, NAC reduced the kidney damage caused by the contrast. NAC treatment was associated with a decrease in SOD levels and an increase in MDA. These findings suggested that NGAL was a superior indicator of CIN than Scr, as NGAL was able to detect kidney damage much earlier. Furthermore, NAC treatment inhibited oxidative stress, thus protecting against CIN. PMID:27882134

  3. Control by osmotic pressure of voltage-induced permeabilization and gene transfer in mammalian cells.

    PubMed Central

    Golzio, M; Mora, M P; Raynaud, C; Delteil, C; Teissié, J; Rols, M P

    1998-01-01

    Cells can be transiently permeabilized by a membrane potential difference increase induced by the application of high electric pulses. This was shown to be under the control of the pulsing buffer osmotic pressure, when short pulses were applied. In this paper, the effects of buffer osmotic pressure during electric treatment and during the following 10 min were investigated in Chinese hamster ovary cells subjected to long (ms) square wave pulses, a condition needed to mediate gene transfer. No effect on cell permeabilization for a small molecule such as propidium iodide was observed. The use of a hypoosmolar buffer during pulsation allows more efficient loading of cells with beta-galactosidase, a tetrameric protein, but no effect of the postpulse buffer osmolarity was observed. The resulting expression of plasmid coding for beta-galactosidase was strongly controlled by buffer osmolarity during as well as after the pulse. The results, tentatively explained in terms of the effect of osmotic pressure on cell swelling, membrane organization, and interaction between molecules and membrane, support the existence of key steps in plasmid-membrane interaction in the mechanism of cell electrically mediated gene transfer. PMID:9635756

  4. Efficacy and Safety of Continuous Micro-Pump Infusion of 3% Hypertonic Saline combined with Furosemide to Control Elevated Intracranial Pressure

    PubMed Central

    Li, Yuqian; Li, Zhihong; Li, Min; Yang, Yanlong; Wang, Bao; Gao, Li; Zhang, Xingye; Cheng, Hongyu; Fang, Wei; Zhao, Bo; Wang, Boliang; Gao, Guodong; Li, Lihong

    2015-01-01

    Background Elevated intracranial pressure is one of the most common problems in patients with diverse intracranial disorders, leading to increased morbidity and mortality. Effective management for increased intracranial pressure is based mainly on surgical and medical techniques with hyperosmolar therapy as one of the core medical treatments. The study aimed to explore the effects of continuous micro-pump infusions of 3% hypertonic saline combined with furosemide on intracranial pressure control. Material/Methods We analyzed data on 56 eligible participants with intracranial pressure >20 mmHg from March 2013 to July 2014. The target was to increase and maintain plasma sodium to a level between 145 and 155 mmol/L and osmolarity to a level of 310 to 320 mOsmol/kg. Results Plasma sodium levels significantly increased from 138±5 mmol/L at admission to 151±3 mmol/L at 24 h (P<0.01). Osmolarity increased from 282±11 mOsmol/kg at baseline to 311±8 mOsmol/kg at 24 h (P<0.01). Intracranial pressure significantly decreased from 32±7 mmHg to 15±6 mmHg at 24 h (P<0.01). There was a significant improvement in CPP (P<0.01). Moreover, central venous pressure, mean arterial pressure, and Glasgow Coma Scale slightly increased. However, these changes were not statistically significant. Conclusions Continuous infusion of 3% hypertonic saline + furosemide is effective and safe for intracranial pressure control. PMID:26082293

  5. Commandeering Channel Voltage Sensors for Secretion, Cell Turgor, and Volume Control.

    PubMed

    Karnik, Rucha; Waghmare, Sakharam; Zhang, Ben; Larson, Emily; Lefoulon, Cécile; Gonzalez, Wendy; Blatt, Michael R

    2017-01-01

    Control of cell volume and osmolarity is central to cellular homeostasis in all eukaryotes. It lies at the heart of the century-old problem of how plants regulate turgor, mineral and water transport. Plants use strongly electrogenic H(+)-ATPases, and the substantial membrane voltages they foster, to drive solute accumulation and generate turgor pressure for cell expansion. Vesicle traffic adds membrane surface and contributes to wall remodelling as the cell grows. Although a balance between vesicle traffic and ion transport is essential for cell turgor and volume control, the mechanisms coordinating these processes have remained obscure. Recent discoveries have now uncovered interactions between conserved subsets of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins that drive the final steps in secretory vesicle traffic and ion channels that mediate in inorganic solute uptake. These findings establish the core of molecular links, previously unanticipated, that coordinate cellular homeostasis and cell expansion.

  6. Osmotically- induced genes are controlled by the transcription factor TonEBP in cultured cardiomyocytes

    PubMed Central

    Navarro, Paola; Chiong, Mario; Volkwein, Karen; Moraga, Francisco; Ocaranza, María Paz; Jalil, Jorge E.; Lim, Sun Woo; Kim, Jeong-Ah; Kwon, H. Moo; Lavandero, Sergio

    2008-01-01

    Changes in cardiac osmolarity occur in myocardial infarction. Osmoregulatory mechanisms may, therefore, play a crucial role in cardiomyocyte survival. Tonicity-responsive enhancer binding protein (TonEBP) is a key transcription factor participating in the adaptation of cells to increases in tonicity. However, it is unknown whether cardiac TonEBP is activated by tonicity. Hypertonicity activated transcriptional activity of TonEBP, increased the amounts of both TonEBP mRNA and protein, and induced both the mRNA and protein of TonEBP target genes (aldose reductase and heat shock protein-70). Hypotonicity decreased the amount of TonEBP protein indicating bidirectional osmoregulation of this transcription factor. Adenoviral expression of a dominant negative TonEBP suppressed the hypertonicity-dependent increase of aldose reductase protein. These results indicated that TonEBP controls osmoregulatory mechanisms in cardiomyocytes. PMID:18502201

  7. [No free water in the treatment of "hyperosmolar diabetic coma": treatment control by comparing serum and CSF (author's transl)].

    PubMed

    Irsigler, K; Kaspar, L; Bruneder, H; Lageder, H

    1977-11-18

    Some serum and CSF concentrations were measured in five patients with severe hyperosmolar coma (mean blood sugar = 58.9 mmol/l; osmolarity = 406 mosmol/l). A gradual decrease of serum osmolarity prevented the development of an osmotic gradient between CSF and extracellular space. Insulin treatment (1-20 IU/h) with a motor infusion pump and infusion of hypertonic solutions decreased serum osmolarity by 2-4 mosmol/l X h. The faster fall of glucose in the extracellular space was compensated by hypertonic saline infusions (up to 365 mosmol/l). All patients survived.

  8. Shape and Mechanical Control of Poly(ethylene oxide) Based Polymersome with Polyoxometalates via Hydrogen Bond.

    PubMed

    Jing, Benxin; Wang, Xiaofeng; Wang, Haitao; Qiu, Jie; Shi, Yi; Gao, Haifeng; Zhu, Yingxi

    2017-02-23

    Polymersomes are self-assembled vesicles of amphiphilic block copolymers and have been explored for wide applications from drug delivery to micro/nanoreactors. As polymersomes are soft and highly deformable, their shape instability due to osmolarity difference across polymer membranes and low elasticity could conversely limit their practical use. Instead of selecting particular polymer chemical reactions to enhance the mechanical properties, we have employed inorganic polyoxometalate (POM) clusters as simple physical cross-linkers to control the shape and mechanical stability of polymersomes in aqueous suspensions. Robust spherical shape with enhanced elastic and bending moduli of POM-dressed poly(ethylene oxide) (PEO) based polymersomes is achieved. We have accounted for the hydrogen bonding between POM and PEO blocks for the adsorption and stabilization of POMS on polymersomes, whose interaction strength could also be tuned by mixing solvents of hydrogen bond donors or receptors with water. The stimuli-responsive properties of POMs are introduced in POM-dressed polymersomes upon the interaction of POMs with PEO blocks in aqueous media. As POM can be used as nanomedicines, catalysts, and other functional nanomaterials, POM-dressed polymersomes with significant shape and mechanical reinforcement could broaden the applications of PEO-based polymersomes and other PEO-tethered nanocolloids.

  9. Birth Control

    MedlinePlus

    ... girlshealth.gov/ Home Body Your sexuality Birth control Birth control Birth control (also called contraception) may seem confusing ... more. What do I need to know about birth control? top The more you know about birth control, ...

  10. Dream controller

    DOEpatents

    Cheng, George Shu-Xing; Mulkey, Steven L; Wang, Qiang; Chow, Andrew J

    2013-11-26

    A method and apparatus for intelligently controlling continuous process variables. A Dream Controller comprises an Intelligent Engine mechanism and a number of Model-Free Adaptive (MFA) controllers, each of which is suitable to control a process with specific behaviors. The Intelligent Engine can automatically select the appropriate MFA controller and its parameters so that the Dream Controller can be easily used by people with limited control experience and those who do not have the time to commission, tune, and maintain automatic controllers.

  11. Influence of clearing solutions osmolarity on the optical properties of RBC

    NASA Astrophysics Data System (ADS)

    Zhestkov, Dmitry M.; Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.

    2004-08-01

    The possibility of immersion clearing of human blood in visible and NIR spectral range has been discussed. Based on presented model the spectral behavior of scattering and absorption characteristics of blood caused by immersion properties of glucose solution has been analyzed. The influence of osmotic properties of glucose solution on blood erythrocytes has been shown.

  12. Red blood cell micromanipulation with elliptical laser beam profile optical tweezers in different osmolarity conditions

    NASA Astrophysics Data System (ADS)

    Spyratou, E.; Makropoulou, M.; Serafetinides, A. A.

    2011-07-01

    In this work optical tweezers with elliptical beam profiles have been developed in order to examine the effect of optical force on fresh red blood cells (RBC) in isotonic, hypertonic and hypotonic buffer solutions. Considering that the optical force depends essentially on the cell surface and the cytoplasmic refractive index, it is obvious that biochemical modifications associated with different states of the cell will influence its behaviour in the optical trap. Line optical tweezers were used to manipulate simultaneously more than one red blood cell. After we have been manipulated a RBC with an elliptical laser beam profile in an isotonic or hypertonic buffer, we noticed that it rotates by itself when gets trapped by optical tweezers and undergoes folding. Further shape deformations can be observed attributed to the competition between alignment and rotational torque which are transferred by laser light to the cell. In hypotonic buffer RBCs become spherical and do not rotate or fold since the resultant force due to rays emerging from diametrically opposite points of the cell leads to zero torque. Manipulation of fresh red blood cells in isotonic solution by line optical tweezers leads to folding and elongation of trapped RBCs. Membrane elasticity properties such as bending modulus can be estimated by measuring RBC's folding time in function with laser power.

  13. AGREEMENT BETWEEN DIFFERENT EQUATIONS TO ESTIMATE OSMOLARITY OF PARENTERAL NUTRITION SOLUTIONS.

    PubMed

    Valero Zanuy, M A; Pablos Bravo, S; Lazaro Cebas, A; Garcia Sanchez, J; Gomis Muñoz, P; Moreno Villares, J M; Leon Sanz, M

    2015-12-01

    Objetivo: nuestro objetivo era medir la osmolaridad de varias fórmulas de nutrición parenteral (NP) compuestas por diferentes componentes para determinar si las ecuaciones para calcular la osmolaridad de la solución, descritas en la literatura, predicen su osmolalidad en la práctica clínica. Método: se midió mediante osmometría la osmolalidad de 12 fórmulas de NP diferentes: 9 para acceso venoso central y 3 para acceso periférico, en un estudio transversal. Se analizó el acuerdo (test de correlación de Pearson) y las diferencias entre la osmolalidad medida y la osmolaridad calculada mediante tres fórmulas diferentes: ecuación de Pereira Da Silva, ecuación del manual de práctica clínica de ASPEN y ecuación de las guías de ASPEN. Resultados: la media ± desviación estándar de las soluciones era 1.789 ± 256 (rango 1.540 – 2.372) y 751 ± 64 mOsm/kg (rango 689 – 817) para perfusión central y periférica, respectivamente. La osmolalidad era debida principalmente a la glucosa (r = 0,975) y a los aminoacidos (r = 0,948). Todas las ecuaciones presentaban una buena correlación en el análisis bivariante (p = 0,000). Todas las ecuaciones tendían a infraestimar la osmolalidad, en comparación con el valor medido. Sin embargo, la ecuación de las guías de la ASPEN sobreestimaba la osmolalidad de las NP periféricas. Conclusiones: conocer la osmolaridad de la solución de NP periférica es importante para reducir el riesgo de flebitis. Las diferentes ecuaciones descritas en la literatura muestran una buena correlación entre ellas, aunque en general infraestiman la osmolalidad.

  14. Osmolar regulation of endothelin-1 production by rat inner medullary collecting duct.

    PubMed Central

    Kohan, D E; Padilla, E

    1993-01-01

    Recent evidence has implicated endothelin-1 (ET-1) as an autocrine inhibitor of inner medullary collecting duct (IMCD) sodium and water transport. The regulators of IMCD ET-1 production are, however, largely unknown. Because of the unique hypertonic environment of the IMCD, the effect of varying extracellular tonicity on IMCD ET-1 production was evaluated. Increasing media osmolality from 300 to 450 mosmol with NaCl or mannitol but not urea caused a marked dose- and time-dependent reduction in ET-1 release by and ET-1 mRNA in cultured rat IMCD cells. In contrast, increasing osmolality had no effect on ET-1 production by rat endothelial or mesangial cells. To see if ET-1 varies in a similar manner in vivo, ET-1 production was assessed in volume expanded (lower medullary tonicity) or volume depleted (high medullary tonicity) rats. Urinary ET-1 excretion and inner medulla ET-1 mRNA were significantly reduced in volume depleted as compared to volume expanded animals. These results indicate that extracellular sodium concentration inhibits ET-1 production specifically in IMCD cells. We speculate that extracellular sodium concentration, via regulation of ET-1 production, provides a link between volume status and IMCD sodium and water reabsorption. PMID:8450052

  15. Rodent Control

    ERIC Educational Resources Information Center

    Indian Journal of Adult Education, 1975

    1975-01-01

    Strategies for rodent control in crop fields, threshing yards, and rural residential areas are presented together with an operational plan for implementing a program for rodent control at the national level. Training personnel in rodent control procedures and procedures for educating the public in the necessity for control are covered. (EC)

  16. All-trans retinol and retinol-binding protein from embryonic cerebrospinal fluid exhibit dynamic behaviour during early central nervous system development.

    PubMed

    Parada, Carolina; Gato, Angel; Bueno, David

    2008-06-11

    Embryonic cerebrospinal fluid (E-CSF) is involved in the regulation of survival, proliferation and neurogenesis of neuroectodermal progenitor cells, as well as in the control of mesencephalic gene expression in collaboration with the isthmic organizer. Recently, we showed the presence of retinol-binding protein (RBP) within the E-CSF proteome. RBP is an all-trans retinol carrier, a molecule that can be metabolized into retinoic acid, a morphogen involved in central nervous system (CNS) morphogenesis and patterning. Here we demonstrate the presence of all-trans retinol within the E-CSF and analyse the dynamics of RBP and all-trans retinol within this fluid, as well as the expression of retinoic acid-synthesizing enzymes during early CNS development. Our results suggest a relationship between the dynamics of these molecules and the early events of CNS patterning.

  17. Propulsion controls

    NASA Technical Reports Server (NTRS)

    Harkney, R. D.

    1980-01-01

    Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems. The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept.

  18. Restructurable Controls

    NASA Technical Reports Server (NTRS)

    Montoya, R. J. (Compiler); Howell, W. E. (Compiler); Bundick, W. T. (Compiler); Ostroff, A. J. (Compiler); Hueschen, R. M. (Compiler); Belcastro, C. M. (Compiler)

    1983-01-01

    Restructurable control system theory, robust reconfiguration for high reliability and survivability for advanced aircraft, restructurable controls problem definition and research, experimentation, system identification methods applied to aircraft, a self-repairing digital flight control system, and state-of-the-art theory application are addressed.

  19. Controlling Fertility.

    ERIC Educational Resources Information Center

    Donnay, France

    1991-01-01

    Recent developments in fertility control are presented in relation to the global demographic situation. Discussion focuses on changes in scientific knowledge and concepts that have shifted the focus from birth control to planned parenthood to the notion of controlled fertility. The place of family planning programs, including their socioeconomic…

  20. Complex Regulatory Network Controls Initial Adhesion and Biofilm Formation in Escherichia coli via Regulation of the csgD Gene

    PubMed Central

    Prigent-Combaret, Claire; Brombacher, Eva; Vidal, Olivier; Ambert, Arnaud; Lejeune, Philippe; Landini, Paolo; Dorel, Corinne

    2001-01-01

    The Escherichia coli OmpR/EnvZ two-component regulatory system, which senses environmental osmolarity, also regulates biofilm formation. Up mutations in the ompR gene, such as the ompR234 mutation, stimulate laboratory strains of E. coli to grow as a biofilm community rather than in a planktonic state. In this report, we show that the OmpR234 protein promotes biofilm formation by binding the csgD promoter region and stimulating its transcription. The csgD gene encodes the transcription regulator CsgD, which in turn activates transcription of the csgBA operon encoding curli, extracellular structures involved in bacterial adhesion. Consistent with the role of the ompR gene as part of an osmolarity-sensing regulatory system, we also show that the formation of biofilm by E. coli is inhibited by increasing osmolarity in the growth medium. The ompR234 mutation counteracts adhesion inhibition by high medium osmolarity; we provide evidence that the ompR234 mutation promotes biofilm formation by strongly increasing the initial adhesion of bacteria to an abiotic surface. This increase in initial adhesion is stationary phase dependent, but it is negatively regulated by the stationary-phase-specific sigma factor RpoS. We propose that this negative regulation takes place via rpoS-dependent transcription of the transcription regulator cpxR; cpxR-mediated repression of csgB and csgD promoters is also triggered by osmolarity and by curli overproduction, in a feedback regulation loop. PMID:11717281

  1. Complex regulatory network controls initial adhesion and biofilm formation in Escherichia coli via regulation of the csgD gene.

    PubMed

    Prigent-Combaret, C; Brombacher, E; Vidal, O; Ambert, A; Lejeune, P; Landini, P; Dorel, C

    2001-12-01

    The Escherichia coli OmpR/EnvZ two-component regulatory system, which senses environmental osmolarity, also regulates biofilm formation. Up mutations in the ompR gene, such as the ompR234 mutation, stimulate laboratory strains of E. coli to grow as a biofilm community rather than in a planktonic state. In this report, we show that the OmpR234 protein promotes biofilm formation by binding the csgD promoter region and stimulating its transcription. The csgD gene encodes the transcription regulator CsgD, which in turn activates transcription of the csgBA operon encoding curli, extracellular structures involved in bacterial adhesion. Consistent with the role of the ompR gene as part of an osmolarity-sensing regulatory system, we also show that the formation of biofilm by E. coli is inhibited by increasing osmolarity in the growth medium. The ompR234 mutation counteracts adhesion inhibition by high medium osmolarity; we provide evidence that the ompR234 mutation promotes biofilm formation by strongly increasing the initial adhesion of bacteria to an abiotic surface. This increase in initial adhesion is stationary phase dependent, but it is negatively regulated by the stationary-phase-specific sigma factor RpoS. We propose that this negative regulation takes place via rpoS-dependent transcription of the transcription regulator cpxR; cpxR-mediated repression of csgB and csgD promoters is also triggered by osmolarity and by curli overproduction, in a feedback regulation loop.

  2. Control Software

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Real-Time Innovations, Inc. (RTI) collaborated with Ames Research Center, the Jet Propulsion Laboratory and Stanford University to leverage NASA research to produce ControlShell software. RTI is the first "graduate" of Ames Research Center's Technology Commercialization Center. The ControlShell system was used extensively on a cooperative project to enhance the capabilities of a Russian-built Marsokhod rover being evaluated for eventual flight to Mars. RTI's ControlShell is complex, real-time command and control software, capable of processing information and controlling mechanical devices. One ControlShell tool is StethoScope. As a real-time data collection and display tool, StethoScope allows a user to see how a program is running without changing its execution. RTI has successfully applied its software savvy in other arenas, such as telecommunications, networking, video editing, semiconductor manufacturing, automobile systems, and medical imaging.

  3. Voltage Controller

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Power Efficiency Corporation, specifically formed to manufacture and develop products from NASA technology, has a license to a three-phase power factor controller originally developed by Frank Nola, an engineer at Marshall Space Flight Center. Power Efficiency and two major distributors, Performance Control and Edison Power Technologies, use the electronic control boards to assemble three different motor controllers: Power Commander, Performance Controller, and Energy Master. The company Power Factor Controller reduces excessive energy waste in AC induction motors. It is used in industries and applications where motors operate under variable loads, including elevators and escalators, machine tools, intake and exhaust fans, oil wells, conveyors, pumps, die casting, and compressors. Customer lists include companies such as May Department Stores, Caesars Atlantic City, Ford Motors, and American Axle.

  4. Mosquito Control

    MedlinePlus

    Jump to main content US EPA United States Environmental Protection Agency Search Search Share Facebook Twitter Google+ Pinterest Contact Us Mosquito Control About Mosquitoes General Information Life ...

  5. Power Controller

    NASA Astrophysics Data System (ADS)

    1983-01-01

    The power factor controller (PFC) senses shifts in the relationship between voltage and current, and matches them with a motor's need. This prevents waste as motors do not need a high voltage when they are not operating at full load conditions. PFC is manufactured by Nordic Controls Company, among others, and has proved extremely cost effective.

  6. CONTROL ROD

    DOEpatents

    Walker, D.E.; Matras, S.

    1963-04-30

    This patent shows a method of making a fuel or control rod for a nuclear reactor. Fuel or control material is placed within a tube and plugs of porous metal wool are inserted at both ends. The metal wool is then compacted and the tube compressed around it as by swaging, thereby making the plugs liquid- impervious but gas-pervious. (AEC)

  7. Environmental Controls.

    ERIC Educational Resources Information Center

    Schneiderman, Helen, Ed.

    1994-01-01

    Environmental control units, or ECUs, are devices or systems which allow for alternate access to electronic or electrical devices and those objects, like draperies and doors, which may be adapted for use with electricity. Such devices offer the person with a mobility limitation the opportunity to control his or her environment, thus enhancing the…

  8. Symptom control.

    PubMed

    Chang, Victor T; Ingham, Jane

    2003-01-01

    Symptom control has become increasingly recognized as an important goal in patient care. In this article, advances in symptom assessment, and various definitions of symptom improvement are reviewed. Theoretical concepts underlying symptom control and clinically significant change are presented, as well as the role of symptom control as an endpoint in clinical trials. Symptom control is then surveyed in two broad categories for selected symptoms. The first area is therapy related symptoms, secondary to chemotherapy, radiation, hormonal therapy, and surgery. Symptoms reviewed include chemotherapy related mucositis, emesis, fatigue; hot flashes; and radiation related dermatitis, xerostomia, and mucositis. The second area is palliative oncologic approaches to disease-related symptoms. Results in palliative chemotherapy, palliative radiation therapy, cancer pain, and lack of appetite are summarized. Areas requiring further research are noted. Findings are presented in both a clinical and research context to help guide the reader with interpreting symptom control studies.

  9. Detonation control

    SciTech Connect

    Mace, Jonathan L.; Seitz, Gerald J.; Bronisz, Lawrence E.

    2016-10-25

    Detonation control modules and detonation control circuits are provided herein. A trigger input signal can cause a detonation control module to trigger a detonator. A detonation control module can include a timing circuit, a light-producing diode such as a laser diode, an optically triggered diode, and a high-voltage capacitor. The trigger input signal can activate the timing circuit. The timing circuit can control activation of the light-producing diode. Activation of the light-producing diode illuminates and activates the optically triggered diode. The optically triggered diode can be coupled between the high-voltage capacitor and the detonator. Activation of the optically triggered diode causes a power pulse to be released from the high-voltage capacitor that triggers the detonator.

  10. Aiming Control.

    DTIC Science & Technology

    1987-10-01

    positive definite solution of A1Qy+QyAo+I--QyBBTQY=O (5.2) The logarithmic residence time of system (3.1) with the stabilizing control (5.1) in a I...a bounded is E bou,,,,dby, ii I)-2=(6 2 This completes the prooof the necesity. Suffidency: The proof is by conatnction. Select a stabilizing control u...a - . Q.LD. Proof of Theorem 3.3: It follows from the results of [151, [21] that for each y > 0, K? defined by (3.4) is a stabilizing control and

  11. REACTOR CONTROL

    DOEpatents

    Fortescue, P.; Nicoll, D.

    1962-04-24

    A control system employed with a high pressure gas cooled reactor in which a control rod is positioned for upward and downward movement into the neutron field from a position beneath the reactor is described. The control rod is positioned by a coupled piston cylinder releasably coupled to a power drive means and the pressurized coolant is directed against the lower side of the piston. The coolant pressure is offset by a higher fiuid pressure applied to the upper surface of the piston and means are provided for releasing the higher pressure on the upper side of the piston so that the pressure of the coolant drives the piston upwardly, forcing the coupled control rod into the ncutron field of the reactor. (AEC)

  12. Under Control.

    ERIC Educational Resources Information Center

    Henry, Rich

    2001-01-01

    Offers advice on how school administrators can properly plan and monitor school construction projects to contain costs. Cost control tips discussed include project scope definition, contract bidding and awarding practice, and project management techniques. (GR)

  13. CONTROL ROD

    DOEpatents

    Zinn, W.H.; Ross, H.V.

    1958-11-18

    A control rod is described for a nuclear reactor. In certaln reactor designs it becomes desirable to use a control rod having great width but relatively llttle thickness. This patent is addressed to such a need. The neutron absorbing material is inserted in a triangular tube, leaving volds between the circular insert and the corners of the triangular tube. The material is positioned within the tube by the use of dummy spacers to achleve the desired absorption pattern, then the ends of the tubes are sealed with suitable plugs. The tubes may be welded or soldered together to form two flat surfaces of any desired width, and covered with sheetmetal to protect the tubes from damage. This design provides a control member that will not distort under the action of outside forces or be ruptured by gases generated within the jacketed control member.

  14. Drug Control

    ERIC Educational Resources Information Center

    Leviton, Harvey S.

    1975-01-01

    This article attempts to assemble pertinent information about the drug problem, particularily marihuana. It also focuses on the need for an educational program for drug control with the public schools as the main arena. (Author/HMV)

  15. CONTROL SYSTEM

    DOEpatents

    Shannon, R.H.; Williamson, H.E.

    1962-10-30

    A boiling water type nuclear reactor power system having improved means of control is described. These means include provisions for either heating the coolant-moderator prior to entry into the reactor or shunting the coolantmoderator around the heating means in response to the demand from the heat engine. These provisions are in addition to means for withdrawing the control rods from the reactor. (AEC)

  16. Airspace Control

    DTIC Science & Technology

    2011-02-02

    it does not display a currently valid OMB control number. 1 . REPORT DATE 02 FEB 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4...each other; select the best course of action; and produce a joint operation plan or order (JP 1 - 02 ). A major element of the JOPP is campaign planning... 1 - 02 ). Airspace control should be integrated throughout the JOPP and campaign planning to ensure joint air operations support the JFC‘s plan.60

  17. Controlling turbulence

    NASA Astrophysics Data System (ADS)

    Kühnen, Jakob; Hof, Björn

    2015-11-01

    We show that a simple modification of the velocity profile in a pipe can lead to a complete collapse of turbulence and the flow fully relaminarises. The annihilation of turbulence is achieved by a steady manipulation of the streamwise velocity component alone, greatly reducing control efforts. Several different control techniques are presented: one with a local modification of the flow profile by means of a stationary obstacle, one employing a nozzle injecting fluid through a small gap at the pipe wall and one with a moving wall, where a part of the pipe is shifted in the streamwise direction. All control techniques act on the flow such that the streamwise velocity profile becomes more flat and turbulence gradually grows faint and disappears. In a smooth straight pipe the flow remains laminar downstream of the control. Hence a reduction in skin friction by a factor of 8 and more can be accomplished. Stereoscopic PIV-measurements and movies of the development of the flow during relaminarisation are presented.

  18. Motor Controllers

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Kollmorgen Corporation's Mermaid II two person submersible is propeller-driven by a system of five DC brushless motors with new electronic controllers that originated in work performed in a NASA/DOE project managed by Lewis Research Center. A key feature of the system is electric commutation rather than mechanical commutation for converting AC current to DC.

  19. Dynamics & Control

    DTIC Science & Technology

    2012-03-06

    This project takes the first steps towards a “Compressive Information Extraction” paradigm: Unmanned vehicles Flight and perch sensors Human in the...the program has solid efforts in control of MAVs, hypersonic vehicles , smart materials and biological systems. • Support of fundamental research...BRIEF DESCRIPTION OF PORTFOLIO: Developing mathematical theory and algorithms based on the interplay of dynamical systems and

  20. Birth Control

    MedlinePlus

    ... your health, frequency of sexual activity, number of sexual partners and desire to have children in the future. Your health care provider can help you select the best form of birth control for you. NIH: National Institute of Child Health and Human Development

  1. Asymptotic controllability and optimal control

    NASA Astrophysics Data System (ADS)

    Motta, M.; Rampazzo, F.

    We consider a control problem where the state must approach asymptotically a target C while paying an integral cost with a non-negative Lagrangian l. The dynamics f is just continuous, and no assumptions are made on the zero level set of the Lagrangian l. Through an inequality involving a positive number p and a Minimum Restraint FunctionU=U(x) - a special type of Control Lyapunov Function - we provide a condition implying that (i) the system is asymptotically controllable, and (ii) the value function is bounded by U/p. The result has significant consequences for the uniqueness issue of the corresponding Hamilton-Jacobi equation. Furthermore it may be regarded as a first step in the direction of a feedback construction.

  2. COPD - control drugs

    MedlinePlus

    Chronic obstructive pulmonary disease - control drugs; Bronchodilators - COPD - control drugs; Beta agonist inhaler - COPD - control drugs; Anticholinergic inhaler - COPD - control drugs; Long-acting inhaler - COPD - control drugs; ...

  3. Vehicle Controller

    NASA Technical Reports Server (NTRS)

    1985-01-01

    UNISTICK is an airplane-like joystick being developed by Johnson Engineering under NASA and VA sponsorship. It allows a driver to control a vehicle with one hand, and is based upon technology developed for the Apollo Lunar Landings of the 1970's. It allows severely handicapped drivers to operate an automobile or van easily. The system is expected to be in production by March 1986.

  4. Autonomous control

    NASA Technical Reports Server (NTRS)

    Brown, Barbara

    1990-01-01

    KSC has been developing the Knowledge-Based Autonomous Test Engineer (KATE), which is a tool for performing automated monitoring, diagnosis, and control of electromechanical devices. KATE employs artificial intelligence computing techniques to perform these functions. The KATE system consists of a generic shell and a knowledge base. The KATE shell is the portion of the system which performs the monitoring, diagnosis, and control functions. It is generic in the sense that it is application independent. This means that the monitoring activity, for instance, will be performed with the same algorithms regardless of the particular physical device being used. The knowledge base is the portion of the system which contains specific functional and behavorial information about the physical device KATE is working with. Work is nearing completion on a project at KSC to interface a Texas Instruments Explorer running a LISP version of KATE with a Generic Checkout System (GCS) test-bed to control a physical simulation of a shuttle tanking system (humorously called the Red Wagon because of its color and mobility). The Autonomous Control System (ACS) project supplements and extends the KATE/GCS project by adding three other major activities. The activities include: porting KATE from the Texas Instruments Explorer machine to an Intel 80386-based UNIX workstation in the LISP language; rewriting KATE as necessary to run on the same 80386 workstation but in the Ada language; and investigating software and techniques to translate ANSI Standard Common LISP to Mil Standard Ada. Primary goals of this task are as follows: (1) establish the advantages of using expert systems to provide intelligent autonomous software for Space Station Freedom applications; (2) determine the feasibility of using Ada as the run-time environment for model-based expert systems; (3) provide insight into the advantages and disadvantagesof using LISP or Ada in the run-time environment for expert systems; and (4

  5. REACTOR CONTROL

    DOEpatents

    Ruano, W.J.

    1957-12-10

    This patent relates to nuclear reactors of the type which utilize elongited rod type fuel elements immersed in a liquid moderator and shows a design whereby control of the chain reaction is obtained by varying the amount of moderator or reflector material. A central tank for containing liquid moderator and fuel elements immersed therein is disposed within a surrounding outer tank providing an annular space between the two tanks. This annular space is filled with liquid moderator which functions as a reflector to reflect neutrons back into the central reactor tank to increase the reproduction ratio. Means are provided for circulating and cooling the moderator material in both tanks and additional means are provided for controlling separately the volume of moderator in each tank, which latter means may be operated automatically by a neutron density monitoring device. The patent also shows an arrangement for controlling the chain reaction by injecting and varying an amount of poisoning material in the moderator used in the reflector portion of the reactor.

  6. Current status of oral rehydration as a strategy for the control of diarrhoeal diseases.

    PubMed

    Mahalanabis, D

    1996-07-01

    For more than two decades, WHO and UNICEF have recommended a single formulation of oral rehydration salts (ORS) solution based on glucose and three salts. This product has proven safe and highly effective in treating and preventing dehydration from diarrhoea of all causes and in all age groups in worldwide use and has substantially contributed to the saving of lives in developing countries. However, oral rehydration therapy (ORT) using this formulation does not make diarrhoea any less severe or stop it sooner; which is what is required. During the last 16 yr numerous studies were undertaken to develop an improved ORS that could, in addition to being effective therapy to treat and prevent dehydration, reduce severity and duration of diarrhoea. Controlled clinical trials of ORS formulations containing aminoacids showed that, while they were substantially more absorption efficient in cholera, they were no more effective than standard ORS in infants and children with noncholera diarrhoea; none of these formulations are considered a suitable replacement for standard ORS. Rice-based ORS, in a number of studies, was found superior to standard ORS in adults and children with cholera and its use in such patients is recommended. However, the benefit of using rice-based ORS in infants and small children was either small or insignificant compared to standard ORS, when feeding during ORT was actively pursued. Rice-based ORS was also as effective as standard ORS in infants under 6 months of age and in severely malnourished children. Recently, several studies evaluated glucose-based ORS made hypoosmolar by reducing the concentration of glucose and sodium (with glucose concentration of 75-90 and sodium 60-75 mmol/l and osmolarity of 225-250 mosm/l). These hypoosmolar solutions showed clinically significant benefit in reducing the severity of diarrhoea and the need for supplemental i.v. therapy in infants and children. In limited studies, similar results were obtained in adults

  7. Signature control

    NASA Astrophysics Data System (ADS)

    Pyati, Vittal P.

    The reduction of vehicle radar signature is accomplished by means of vehicle shaping, the use of microwave frequencies-absorbent materials, and either passive or active cancellation techniques; such techniques are also useful in the reduction of propulsion system-associated IR emissions. In some anticipated scenarios, the objective is not signature-reduction but signature control, for deception, via decoy vehicles that mimic the signature characteristics of actual weapons systems. As the stealthiness of airframes and missiles increases, their propulsion systems' exhaust plumes assume a more important role in detection by an adversary.

  8. Thermal control

    NASA Astrophysics Data System (ADS)

    Haslett, B.

    1984-02-01

    There are basically three key ingredients to the thermal control system for any large space platform or space station. These are heat rejection (from a centralized radiator or from body mounted radiators), heat acquisition (from payloads), and heat transport (via a transport loop to the radiator). The echnical approach in the heat rejection area is to construct the radiator from individual elements so that it can be built on-orbit, is very insensitive to meteoroid and debris hazards, and is repairable. In the area of thermal acquisition and transport an added effort to better understand two phase flow in zero gravity by analysis and testing is suggested.

  9. Heliostat control

    DOEpatents

    Kaehler, James A.

    1984-01-01

    An improvement in a system and method of controlling heliostat in which the heliostat is operable in azimuth and elevation by respective stepper motors and including the respective steps or means for calculating the position for the heliostat to be at a commanded position, determining the number of steps in azimuth and elevation for each respective motor to get to the commanded position and energizing both the azimuth and elevation stepper motors to run in parallel until predetermined number of steps away from the closest commanded position in azimuth and elevation so that the closest position has been achieved, and thereafter energizing only the remaining motor to bring it to its commanded position. In this way, the heliostat can be started from a stowed position in the morning and operated by a computer means to its commanded position and kept correctly oriented throughout the day using only the time of the day without requiring the usual sensors and feedback apparatus. A computer, or microprocessor, can then control a plurality of many heliostats easily and efficiently throughout the day.

  10. [Controlled hypernatremia].

    PubMed

    Petit, L; Masson, F; Cottenceau, V; Sztark, F

    2006-08-01

    Hypernatremia exerts its main effect on the brain through the osmotic gradient it creates on either side of the blood brain barrier, which is impermeable to sodium. This generates a transfer of water from the intracellular to the vascular sector leading to temporary cell shrinkage. Osmoregulation permits cerebral cells to accumulate osmoactive molecules in order to restore their initial volume. It has been demonstrated in animals with brain injury that intracellular dehydration occurs essentially in the nonlesioned hemisphere. In most experimental studies, the reduction in cerebral volume obtained by hypertonic saline (HS) perfusion is accompanied by an intracranial pressure decrease, even under hemorrhagic shock conditions. Initially, clinical studies successfully used HS, as an alternative to mannitol, in the treatment of acute and refractory intracranial hypertension. Then continuous infusion of HS, with the objective of inducing hypernatremia, had produced encouraging effects on intracranial pressure control. However, these results were limited to non-randomized studies, without control groups and mainly in pediatric patients. Nevertheless, the use of HS on intracranial hypertension, refractory to conventional treatments, could be reasonable under strict monitoring of natremia as well as its adverse effects.

  11. The role of the peripheral cannabinoid system in the pathogenesis of detrusor overactivity evoked by increased intravesical osmolarity in rats.

    PubMed

    Juszczak, Kajetan; Maciukiewicz, Piotr

    2015-08-01

    The cannabinoid receptors CB1 and CB2 are localized in the urinary bladder and play a role in the regulation of its function. We investigated the pathomechanisms through which hyperosmolarity induces detrusor overactivity (DO). We compared urinary bladder activity in response to blockade of CB1 and CB2 receptors using AM281 and AM630, respectively, in normal rats and after hyperosmolar stimulation. Experiments were performed on 44 rats. DO was induced by intravesical instillation of hyperosmolar saline. Surgical procedures and cystometry were performed under urethane anaesthesia. The measurements represent the average of 5 bladder micturition cycles. We analysed basal, threshold, and micturition voiding pressure; intercontraction interval; compliance; functional bladder capacity; motility index; and detrusor overactivity index. The blockage of CB1 and CB2 receptors diminished the severity of hyperosmolar-induced DO. In comparison with naïve animals the increased frequency of voiding with no significant effect on intravesical voiding pressure profile was observed as a result of the blockage of CB1 and CB2 receptors. These results demonstrate that hyperosmolar-induced DO is mediated by CB1 and CB2 receptors. Therefore, the cannabinoid pathway could potentially be a target for the treatment of urinary bladder dysfunction.

  12. Sodium hyaluronate eye drops of different osmolarity for the treatment of dry eye in Sjögren's syndrome patients

    PubMed Central

    Aragona, P; Di Stefano, G; Ferreri, F; Spinella, R; Stilo, A

    2002-01-01

    Aim: To study the effect of the treatment of dry eye in Sjögren's syndrome patients with hypotonic or isotonic hyaluronate eye drops. Methods: 40 Sjögren's syndrome patients were divided in two groups and treated as follows: group 1 with hypotonic (150 mOsm/l) 0.4% hyaluronate eye drops; group 2 with isotonic 0.4% hyaluronate eye drops. The eye drops were instilled six times a day for 90 days. Grading of subjective symptoms, break up time (BUT), corneal fluorescein staining, conjunctival rose bengal staining, Schirmer's I test, and conjunctival impression cytology were carried out at 0 and 15, 30, 90 days from the beginning of the study. Patients were examined in a blind fashion. For the statistical analysis the Student's t test, Mann-Whitney U test, and χ2 test were performed. Results: Symptoms were statistically significantly improved at day 15 in both groups but group 1 patients had a global score statistically significantly better group 2 (p=0.02). At day 15 group 1 patients had an improvement from baseline values of BUT (p=0.003), fluorescein, and rose bengal score (p=0.000001 and p=0.0004 respectively). Group 2 patients had, at day 15, an improvement of BUT and fluorescein score compared to baseline values (p=0.05 and p=0.0001 respectively). A comparison between the two groups showed better results for group 1 patients at day 15 for rose bengal stain (p=0.01) and for BUT (p=0.05) and fluorescein score (p=0.0003) at day 90. The conjunctival impression cytology showed that group 1 had a statistically significant better total score than group 2 starting from day 15 and lasting throughout the study (p<0.02). Also group 2 patients showed an improvement from baseline values starting from day 30 (p=0.000005). Conclusion: Hyaluronate eye drops are useful for treating severe dry eye in Sjögren's syndrome patients. The use of a formulation with pronounced hypotonicity showed better effects on corneoconjunctival epithelium than the isotonic solution. PMID:12140209

  13. Dimethyl adenosine transferase (KsgA) deficiency in Salmonella Enteritidis confers susceptibility to high osmolarity and virulence attenuation in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Dimethyladenosine transferase (KsgA) performs diverse roles in bacteria including ribosomal maturation, DNA mismatch repair, and synthesis of KsgA is responsive to antibiotics and cold temperature. We previously showed that ksgA mutation in Salmonella Enteritidis results in impaired invasiveness i...

  14. Adaptation of extremely halotolerant black yeast Hortaea werneckii to increased osmolarity: a molecular perspective at a glance.

    PubMed

    Plemenitas, A; Vaupotic, T; Lenassi, M; Kogej, T; Gunde-Cimerman, N

    2008-01-01

    Halophilic adaptations have been studied almost exclusively on prokaryotic microorganisms. Discovery of the black yeast Hortaea werneckii as the dominant fungal species in hypersaline waters enabled the introduction of a new model organism to study the mechanisms of salt tolerance in eukaryotes. Its strategies of cellular osmotic adaptations on the physiological and molecular level revealed novel, intricate mechanisms to combat fluctuating salinity. H. werneckii is an extremely halotolerant eukaryotic microorganism and thus a promising source of transgenes for osmotolerance improvement of industrially important yeasts, as well as in crops.

  15. Control apparatus

    NASA Technical Reports Server (NTRS)

    Derkacs, Thomas (Inventor); Fetheroff, Charles W. (Inventor); Matay, Istvan M. (Inventor); Toth, Istvan J. (Inventor)

    1982-01-01

    Although the method and apparatus of the present invention can be utilized to apply either a uniform or a nonuniform covering of material over many different workpieces, the apparatus (20) is advantageously utilized to apply a thermal barrier covering (64) to an airfoil (22) which is used in a turbine engine. The airfoil is held by a gripper assembly (86) while a spray gun (24) is effective to apply the covering over the airfoil. When a portion of the covering has been applied, a sensor (28) is utilized to detect the thickness of the covering. A control apparatus (32) compares the thickness of the covering of material which has been applied with the desired thickness and is subsequently effective to regulate the operation of the spray gun to adaptively apply a covering of a desired thickness with an accuracy of at least plus or minus 0.0015 inches (1.5 mils) despite unanticipated process variations.

  16. Custom controls

    NASA Astrophysics Data System (ADS)

    Butell, Bart

    1996-02-01

    Microsoft's Visual Basic (VB) and Borland's Delphi provide an extremely robust programming environment for delivering multimedia solutions for interactive kiosks, games and titles. Their object oriented use of standard and custom controls enable a user to build extremely powerful applications. A multipurpose, database enabled programming environment that can provide an event driven interface functions as a multimedia kernel. This kernel can provide a variety of authoring solutions (e.g. a timeline based model similar to Macromedia Director or a node authoring model similar to Icon Author). At the heart of the kernel is a set of low level multimedia components providing object oriented interfaces for graphics, audio, video and imaging. Data preparation tools (e.g., layout, palette and Sprite Editors) could be built to manage the media database. The flexible interface for VB allows the construction of an infinite number of user models. The proliferation of these models within a popular, easy to use environment will allow the vast developer segment of 'producer' types to bring their ideas to the market. This is the key to building exciting, content rich multimedia solutions. Microsoft's VB and Borland's Delphi environments combined with multimedia components enable these possibilities.

  17. Birth Control Methods

    MedlinePlus

    ... Z Health Topics Birth control methods Birth control methods > A-Z Health Topics Birth control methods fact ... Publications email updates Enter email Submit Birth control methods Birth control (contraception) is any method, medicine, or ...

  18. Continuous controlled-infusion of hypertonic saline solution in traumatic brain-injured patients: a 9-year retrospective study

    PubMed Central

    2011-01-01

    Introduction Description of a continuous hypertonic saline solution (HSS) infusion using a dose-adaptation of natremia in traumatic brain injured (TBI) patients with refractory intracranial hypertension (ICH). Methods We performed a single-center retrospective study in a surgical intensive care unit of a tertiary hospital. Fifty consecutive TBI patients with refractory ICH treated with continuous HSS infusion adapted to a target of natremia. In brief, a physician set a target of natremia adapted to the evolution of intracranial pressure (ICP). Flow of NaCl 20% was a priori calculated according to natriuresis, and the current and target natremia that were assessed every 4 hours. Results The HSS infusion was initiated for a duration of 7 (5 to 10) (8 ± 4) days. ICP decreased from 29 (26 to 34) (31 ± 9) mm Hg at H0 to 20 (15 to 26) (21 ± 8) mm Hg at H1 (P < 0.05). Cerebral perfusion pressure increased from 61 (50 to 70) (61 ± 13) mm Hg at H0 up to 67 (60 to 79) (69 ± 12) mm Hg at H1 (P < 0.05). No rebound of ICH was reported after stopping continuous HSS infusion. Natremia increased from 140 (138 to 143) (140 ± 4) at H0 up to 144 (141 to 148) (144 ± 4) mmol/L at H4 (P < 0.05). Plasma osmolarity increased from 275 (268 to 281) (279 ± 17) mmol/L at H0 up to 290 (284 to 307) (297 ± 17) mmol/L at H24 (P < 0.05). The main side effect observed was an increase in chloremia from 111 (107 to 119) (113 ± 8) mmol/L at H0 up to 121 (117 to 124) (121 ± 6) mmol/L at H24 (P < 0.05). Neither acute kidney injury nor pontine myelinolysis was recorded. Conclusions Continuous HSS infusion adapted to close biologic monitoring enables long-lasting control of natremia in TBI patients along with a decreased ICP without any rebound on infusion discontinuation. PMID:22035596

  19. [Oral hydratation with a low osmolality solution in dehydrated children with diarrheic diseases: controlled clinical trial].

    PubMed

    Bernal, Carlos; Velásquez, Claudia; García, Guillermo; Uribe, Gustavo; Palacio, Carlos Mauricio

    2003-03-01

    A clinical trial was conducted to compare the efficacy of a low-osmolarity solution (245 mOsm/L), and a standard oral rehydration solution (ORS) recommended by WHO for children dehydrated by diarrhea. Group 1 (69 children) received WHO/ORS (311 mOsml/L) and group 2 (71 children) received a low-osmolarity solution (245 mOsm/L). Rehydration was successful in 88.4% in group 1 and 92.9% in group 2 (p = 0.35). Rehydration was completed in 5.2 h (SD +/- 1.8) in group 1 and 5.5 (SD +/- 1.7) in group 2 (p = 0.31). Stool output was 6.3 g/kg/h (SD +/- 5.0) in group 1 and 5.6 g/kg/h (SD +/- 5.1) in group 2 (p = 0.94). Sodium at rehydration-completion was 139.3 mEq/L (SD +/- 7.1) in group 1 and 136.7 mEq/L (SD +/- 4.3) in group 2 (p = 0.014). Group 1 was under observation for 21 hours (SD +/- 5.7) and group 2, for 22 hours (SD +/- 5.6). Stool output in group 1 was 5.2 g/kg/h (SD 4.1) and 4.2 gr./kg/h (SD +/- 4.1) in group 2 (p = 0.16). In group 1, 23.1% required intravenous solutions and 9.8% in group 2 (p = 0.03). In treating dehydrated children, the low-osmolarity solution diminished the need for intravenous solutions, corrected most plasmatic sodium disorders, and produced no-risk of developing hyponatremia.

  20. CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES FOR THE VENTILATION SYSTEM AND A PLC SWITCH FOR AUTOMATIC CO (CARBON MONOXIDE) SYSTEM. THE AIR TESTING SYSTEM IS FREE STANDING AND THE FANS ARE COMPUTER-OPERATED. - Alaskan Way Viaduct and Battery Street Tunnel, Seattle, King County, WA

  1. Contact Control, Version 1

    SciTech Connect

    von Sternberg, Alex

    2016-07-21

    The contact control code is a generalized force control scheme meant to interface with a robotic arm being controlled using the Robot Operating System (ROS). The code allows the user to specify a control scheme for each control dimension in a way that many different control task controllers could be built from the same generalized controller. The input to the code includes maximum velocity, maximum force, maximum displacement, and a control law assigned to each direction and the output is a 6 degree of freedom velocity command that is sent to the robot controller.

  2. Neural control: Chaos control sets the pace

    NASA Astrophysics Data System (ADS)

    Schöll, Eckehard

    2010-03-01

    Even simple creatures, such as cockroaches, are capable of complex responses to changes in their environment. But robots usually require complicated dedicated control circuits to perform just a single action. Chaos control theory could allow simpler control strategies to realize more complex behaviour.

  3. Superconducting fault current controller/current controller

    DOEpatents

    Cha, Yung S.

    2004-06-15

    A superconducting fault current controller/current controller employs a superconducting-shielded core reactor (SSCR) with a variable impedance in a secondary circuit to control current in a primary circuit such as an electrical distribution system. In a second embodiment, a variable current source is employed in a secondary circuit of an SSCR to control current in the primary circuit. In a third embodiment, both a variable impedance in one secondary circuit and a variable current source in a second circuit of an SSCR are employed for separate and independent control of current in the primary circuit.

  4. Vehicle Dynamics and Control

    NASA Astrophysics Data System (ADS)

    Rajamani, Rajesh

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system topics covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire models and tire-road friction estimation. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics.

  5. Controllability of asynchronous Boolean multiplex control networks

    NASA Astrophysics Data System (ADS)

    Luo, Chao; Wang, Xingyuan; Liu, Hong

    2014-09-01

    In this article, the controllability of asynchronous Boolean multiplex control networks (ABMCNs) is studied. First, the model of Boolean multiplex control networks under Harvey' asynchronous update is presented. By means of semi-tensor product approach, the logical dynamics is converted into linear representation, and a generalized formula of control-depending network transition matrices is achieved. Second, a necessary and sufficient condition is proposed to verify that only control-depending fixed points of ABMCNs can be controlled with probability one. Third, using two types of controls, the controllability of system is studied and formulae are given to show: (a) when an initial state is given, the reachable set at time s under a group of specified controls; (b) the reachable set at time s under arbitrary controls; (c) the specific probability values from a given initial state to destination states. Based on the above formulae, an algorithm to calculate overall reachable states from a specified initial state is presented. Moreover, we also discuss an approach to find the particular control sequence which steers the system between two states with maximum probability. Examples are shown to illustrate the feasibility of the proposed scheme.

  6. Malagasy Backward Object Control

    ERIC Educational Resources Information Center

    Potsdam, Eric

    2009-01-01

    Backward control is an obligatory interpretational dependency between an overt controller and a nonovert controllee in which the controllee is structurally superior to the controller: "Meg persuaded [Delta]i" ["Roni to give up"]. It contrasts with ordinary forward control, in which the controller is structurally higher: "Meg persuaded Roni"…

  7. PID controllers' fragility.

    PubMed

    Alfaro, Víctor M

    2007-10-01

    In this paper, an index for measuring fragility of proportional integral derivative (PID) controllers is proposed. This index relates the losses of robustness of the control loop when controller parameters change, to the nominal robustness of the control loop. Furthermore, it defines when a PID controller is fragile, nonfragile or resilient.

  8. Directions in propulsion control

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.

    1990-01-01

    Discussed here is research at NASA Lewis in the area of propulsion controls as driven by trends in advanced aircraft. The objective of the Lewis program is to develop the technology for advanced reliable propulsion control systems and to integrate the propulsion control with the flight control for optimal full-system control.

  9. Structural Pest Control.

    ERIC Educational Resources Information Center

    Kahn, M. S.; Hoffman, W. M.

    This manual is designed for those who seek certification as pesticide applicators for industrial, institutional, structural, and health-related pest control. It is divided into six sections covering general pest control, wood-destroying organisms, bird control, fumigation, rodent control, and industrial weed control. The manual gives information…

  10. AIR POLLUTION CONTROL TECHNOLOGIES

    EPA Science Inventory

    This is a chapter for John Wiley & Son's Mechanical Engineers' Handbook, and covers issues involving air pollution control. Various technologies for controlling sulfur oxides is considered including fuel desulfurization. It also considers control of nitrogen oxides including post...

  11. Xenon International Automated Control

    SciTech Connect

    2016-08-05

    The Xenon International Automated Control software monitors, displays status, and allows for manual operator control as well as fully automatic control of multiple commercial and PNNL designed hardware components to generate and transmit atmospheric radioxenon concentration measurements every six hours.

  12. OPTIMUM SYSTEMS CONTROL,

    DTIC Science & Technology

    Variational calculus and continuous optimal control, (4) The maximum principle and Hamilton Jacobi theory, (5) Optimum systems control examples, (6...Discrete variational calculus and the discrete maximum principle, (7) Optimum control of distributed parameter systems, (8) Optimum state estimation in

  13. Essure Permanent Birth Control

    MedlinePlus

    ... and Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... Essure System Essure is a a permanently implanted birth control device for women (female sterilization). Implantation of Essure ...

  14. Gross motor control

    MedlinePlus

    Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they ...

  15. Integrated Control Using the SOFFT Control Structure

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim

    1996-01-01

    The need for integrated/constrained control systems has become clearer as advanced aircraft introduced new coupled subsystems such as new propulsion subsystems with thrust vectoring and new aerodynamic designs. In this study, we develop an integrated control design methodology which accomodates constraints among subsystem variables while using the Stochastic Optimal Feedforward/Feedback Control Technique (SOFFT) thus maintaining all the advantages of the SOFFT approach. The Integrated SOFFT Control methodology uses a centralized feedforward control and a constrained feedback control law. The control thus takes advantage of the known coupling among the subsystems while maintaining the identity of subsystems for validation purposes and the simplicity of the feedback law to understand the system response in complicated nonlinear scenarios. The Variable-Gain Output Feedback Control methodology (including constant gain output feedback) is extended to accommodate equality constraints. A gain computation algorithm is developed. The designer can set the cross-gains between two variables or subsystems to zero or another value and optimize the remaining gains subject to the constraint. An integrated control law is designed for a modified F-15 SMTD aircraft model with coupled airframe and propulsion subsystems using the Integrated SOFFT Control methodology to produce a set of desired flying qualities.

  16. Dynamic power flow controllers

    DOEpatents

    Divan, Deepakraj M.; Prasai, Anish

    2017-03-07

    Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

  17. Biological Control in Agroecosystems

    NASA Astrophysics Data System (ADS)

    Batra, Suzanne W. T.

    1982-01-01

    Living organisms are used as biological pest control agents in (i) classical biological control, primarily for permanent control of introduced perennial weed pests or introduced pests of perennial crops; (ii) augmentative biological control, for temporary control of native or introduced pests of annual crops grown in monoculture; and (iii) conservative or natural control, in which the agroecosystem is managed to maximize the effect of native or introduced biological control agents. The effectiveness of biological control can be improved if it is based on adequate ecological information and theory, and if it is integrated with other pest management practices.

  18. CONTROL LIMITER DEVICE

    DOEpatents

    DeShong, J.A.

    1960-03-01

    A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

  19. Integrated blending control system

    SciTech Connect

    Cogbill, R.B.; Dodd, T.J.; Heilman, P.W.; Heronemus, D.L.; Sears, L.R.; Berryman, L.N.; Baker, R.L.; Guffee, L.E.; Prucha, D.A.; Roberts, D.M.

    1989-07-25

    This patent describes a proppant control system. It comprises: storage bin means for storing particulate material; surge bin means for receiving a flow of the particulate material from the storage bin means; first conveyor means for providing a flow of particulate material to the surge bin means from the storage bin means; second conveyor means for transferring a controllable quantity of the particulate material from the surge bin means; and proppant control means. The control means include: first speed control means for remotely controlling the speed of the first conveyor means; and second speed control means for remotely controlling the speed of the second conveyor means.

  20. Space Digital Controller for Improved Motor Control

    NASA Astrophysics Data System (ADS)

    Alves-Nunes, Samuel; Daras, Gaetan; Dehez, Bruno; Maillard, Christophe; Bekemans, Marc; Michel, Raymond

    2014-08-01

    Performing digital motor control into space equipment is a new challenge. The new DPC (Digital Programmable Controller) is the first chip that we can use as a micro-controller, allowing us to drive motors with digital control schemes. In this paper, the digital control of hybrid stepper motors is considered. This kind of motor is used for solar array rotation and antenna actuation. New digital control technology brings a lot of advantages, allowing an important reduction of thermal losses inside the motor, and a reduction of thermal constraints on power drive electronic components. The opportunity to drive motors with a digital controller also brings many new functionalities like post-failure torque analysis, micro- vibrations and cogging torque reduction, or electro- mechanical damping of solar array oscillations. To evaluate the performance of the system, Field-Oriented Control (FOC) is implemented on a hybrid stepper motor. A test-bench, made of an active load, has been made to emulate the mechanical behaviour of the solar array, by the use of a torsionally-compliant model. The experimental results show that we can drastically reduce electrical power consumption, compared with the currently used open-loop control scheme.

  1. Improving Control of Two Motor Controllers

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.

    2004-01-01

    A computer program controls motors that drive translation stages in a metrology system that consists of a pair of two-axis cathetometers. This program is specific to Compumotor Gemini (or equivalent) motors and the Compumotor 6K-series (or equivalent) motor controller. Relative to the software supplied with the controller, this program affords more capabilities and is easier to use. Written as a Virtual Instrument in the LabVIEW software system, the program presents an imitation control panel that the user can manipulate by use of a keyboard and mouse. There are three modes of operation: command, movement, and joystick. In command mode, single commands are sent to the controller for troubleshooting. In movement mode, distance, speed, and/or acceleration commands are sent to the controller. Position readouts from the motors and from position encoders on the translation stages are displayed in marked fields. At any time, the position readouts can be recorded in a file named by the user. In joystick mode, the program yields control of the motors to a joystick. The program sends commands to, and receives data from, the controller via a serial cable connection, using the serial-communication portion of the software supplied with the controller.

  2. Osmotic control of glycine betaine biosynthesis and degradation in Rhizobium meliloti.

    PubMed Central

    Smith, L T; Pocard, J A; Bernard, T; Le Rudulier, D

    1988-01-01

    Intracellular accumulation of glycine betaine has been shown to confer an enhanced level of osmotic stress tolerance in Rhizobium meliloti. In this study, we used a physiological approach to investigate the mechanism by which glycine betaine is accumulated in osmotically stressed R. meliloti. Results from growth experiments, 14C labeling of intermediates, and enzyme activity assays are presented. The results provide evidence for the pathway of biosynthesis and degradation of glycine betaine and the osmotic effects on this pathway. High osmolarity in the medium decreased the activities of the enzymes involved in the degradation of glycine betaine but not those of enzymes that lead to its biosynthesis from choline. Thus, the concentration of the osmoprotectant glycine betaine is increased in stressed cells. This report demonstrates the ability of the osmolarity of the growth medium to regulate the use of glycine betaine as a carbon and nitrogen source or as an osmoprotectant. The mechanisms of osmoregulation in R. meliloti and Escherichia coli are compared. PMID:3290197

  3. Osmotic control of glycine betaine biosynthesis and degradation in Rhizobium meliloti

    SciTech Connect

    Smith, L.T.; Pocard, J.A.; Bernard, T.; Le Rudulier, D.

    1988-07-01

    Intracellular accumulation of glycine betaine has been shown to confer an enhanced level of osmotic stress tolerance in Rhizobium meliloti. In this study, the authors used a physiological approach to investigate the mechanism by which glycine betaine is accumulated in osmotically stressed R. meliloti. Results from growth experiments, /sup 14/C labeling of intermediates, and enzyme activity assays are presented. The results provide evidence for the pathway of biosynthesis and degradation of glycine betaine and the osmotic effects on this pathway. High osmolarity in the medium decreased the activities of the enzymes involved in the degradation of glycine betaine but not those of enzymes that lead to its biosynthesis from choline. Thus, the concentration of the osmoprotectant glycine betaine is increased in stressed cells. This report demonstrates the ability of the osmolarity of the growth medium to regulate the use of glycine betaine as a carbon and nitrogen source or as an osmoprotectant. The mechanisms of osmoregulation in R. meliloti and Escherichia coli are compared.

  4. Adaptive Cruise Control

    NASA Astrophysics Data System (ADS)

    Winner, Hermann; Danner, Bernd; Steinle, Joachim

    Mit Adaptive Cruise Control, abgekürzt ACC, wird eine Fahrgeschwindigkeitsregelung bezeichnet, die sich an die Verkehrssituation anpasst. Synonyme Bezeichnungen sind Aktive Geschwindigkeitsregelung, Automatische Distanzregelung oder Abstandsregeltempomat. Im englischen Sprachraum fnden sich die weiteren Bezeichnungen Active Cruise Control, Automatic Cruise Control oder Autonomous Intelligent Cruise Control. Als markengeschützte Bezeichnungen sind Distronic und Automatische Distanz-Regelung (ADR) eingetragen.

  5. Programable Multicrate Controller

    NASA Technical Reports Server (NTRS)

    Mook, G. L.; Phillips, M. R.

    1985-01-01

    High-speed, environmentally hardened controller developed for use with commercially available system crates for both experiment control and data handling. Programable crate controller consists of three functional areas: control section utilizes high-speed bit-slice circuitry, memory, and data way interface.

  6. Robot Manipulator Control.

    DTIC Science & Technology

    1983-03-07

    This report presents a synthetic approach for calculating the control of robot manipulators. The initial control problem is broken down into linear ... control and modelling problems. The approach allows derivation of numerous schemes (adaptive or not) of control proposed in the literature and suggests

  7. Aircraft adaptive learning control

    NASA Technical Reports Server (NTRS)

    Lee, P. S. T.; Vanlandingham, H. F.

    1979-01-01

    The optimal control theory of stochastic linear systems is discussed in terms of the advantages of distributed-control systems, and the control of randomly-sampled systems. An optimal solution to longitudinal control is derived and applied to the F-8 DFBW aircraft. A randomly-sampled linear process model with additive process and noise is developed.

  8. Microprocessor control for standardized power control systems

    NASA Technical Reports Server (NTRS)

    Green, D. G.; Perry, E.

    1978-01-01

    The use of microcomputers in space-oriented power systems as a replacement for existing inflexible analog type controllers has been proposed. This study examines multiprocessor systems, various modularity concepts and presents a conceptualized power system incorporating a multiprocessor controller as well as preliminary results from a breadboard model of the proposed system.

  9. Switching Systems: Controllability and Control Design

    DTIC Science & Technology

    2009-04-25

    observations motivates the necessity to search for other methods in order to obtain a useful algorithm that might test controllability in the sign...Contributions to the theory of optimal control,” Boletin de la Sociedad Matematica Mexicana, vol. 5, pp. 102–119, 1960. [38] Kellett, Christopher M. and Andrew R

  10. Control of space stations

    NASA Technical Reports Server (NTRS)

    Lee, K. Y.

    1983-01-01

    A study is made to develop controllers for the NASA-JSC Triangular Space Station and evaluate their performances to make recommendations for structural design and/or control alternatives. The control system design assumes the rigid body of the Space Station and developes the lumped parameter control system by using the Inverse Optimal Control Theory. In order to evaluate the performance of the control system, a Parameter Estimation algorithm is being developed which will be used in modeling an equivalent but simpler Space Station model. Finally, a scaled version of the Space Station is being built for the purpose of physical experiments to evaluate the control system performance.

  11. An intelligent traffic controller

    SciTech Connect

    Kagolanu, K.; Fink, R.; Smartt, H.; Powell, R.; Larsen, E.

    1995-12-01

    A controller with advanced control logic can significantly improve traffic flows at intersections. In this vein, this paper explores fuzzy rules and algorithms to improve the intersection operation by rationalizing phase changes and green times. The fuzzy logic for control is enhanced by the exploration of neural networks for families of membership functions and for ideal cost functions. The concepts of fuzzy logic control are carried forth into the controller architecture. Finally, the architecture and the modules are discussed. In essence, the control logic and architecture of an intelligent controller are explored.

  12. Nuclear reactor control apparatus

    DOEpatents

    Sridhar, Bettadapur N.

    1983-11-01

    Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in the control rod, and cam means for pivoting the latches out of the recess in the control rod when a scram condition occurs. One embodiment of the invention comprises an additional magnetically-operated latch for releasing the control rod under two different conditions, one involving seismic shock.

  13. HYDRAULIC SERVO CONTROL MECHANISM

    DOEpatents

    Hussey, R.B.; Gottsche, M.J. Jr.

    1963-09-17

    A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

  14. Engine roughness control means

    SciTech Connect

    Matsuura, M.; Doi, N.; Yoshioka, S.; Okimoto, H.; Veda, K.

    1987-08-04

    This patent describes a control system for a vehicle engine comprising engine condition detecting means for detecting an engine operating condition and producing an engine condition signal representing the engine operating condition, engine combustion control means for controlling a condition of combustion in the engine; and a control factor storage means for storing control factors for controlling the engine combustion. A modifying means connect the comparator means to receive the output signal and to modify the control factor from the storage means by the output of the comparator means so that the combustion control means is controlled by the modified control factor in a direction that the engine vibrations are suppressed. A reference signal changes means connected with the engine condition detecting means to change the reference roughness signal in accordance with the engine operating condition so that the reference signal is decreased when the engine is in idling operation.

  15. TFTR diagnostic vacuum controller

    SciTech Connect

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller.

  16. Fuzzy and neural control

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.

    1992-01-01

    Fuzzy logic and neural networks provide new methods for designing control systems. Fuzzy logic controllers do not require a complete analytical model of a dynamic system and can provide knowledge-based heuristic controllers for ill-defined and complex systems. Neural networks can be used for learning control. In this chapter, we discuss hybrid methods using fuzzy logic and neural networks which can start with an approximate control knowledge base and refine it through reinforcement learning.

  17. SODR Memory Control Buffer Control ASIC

    NASA Technical Reports Server (NTRS)

    Hodson, Robert F.

    1994-01-01

    The Spacecraft Optical Disk Recorder (SODR) is a state of the art mass storage system for future NASA missions requiring high transmission rates and a large capacity storage system. This report covers the design and development of an SODR memory buffer control applications specific integrated circuit (ASIC). The memory buffer control ASIC has two primary functions: (1) buffering data to prevent loss of data during disk access times, (2) converting data formats from a high performance parallel interface format to a small computer systems interface format. Ten 144 p in, 50 MHz CMOS ASIC's were designed, fabricated and tested to implement the memory buffer control function.

  18. Boiler control systems engineering

    SciTech Connect

    Gilman, J.

    2005-07-01

    The book provides in-depth coverage on how to safely and reliably control the firing of a boiler. Regardless of the capacity or fuel, certain fundamental control systems are required for boiler control. Large utility systems are more complex due to the number of burners and the overall capacity and equipment. This book covers engineering details on control systems and provides specific examples of boiler control including configuration and tuning. References to requirements are based on the 2004 NFPA 85 along with other ISA standards. Detailed chapters cover: Boiler fundamentals including piping and instrument diagrams (P&IDs) and a design basis checklist; Control of boilers, from strategies and bumpless transfer to interlock circuitry and final control elements; Furnace draft; Feedwater; Coal-fired boilers; Fuel and air control; Steam temperature; Burner management systems; Environment; and Control valve sizing. 2 apps.

  19. Digital Optical Control System

    NASA Astrophysics Data System (ADS)

    Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.

    1988-09-01

    We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.

  20. Constrained control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne C.

    1992-01-01

    This paper addresses the problem of the allocation of several flight controls to the generation of specified body-axis moments. The number of controls is greater than the number of moments being controlled, and the ranges of the controls are constrained to certain limits. The controls are assumed to be individually linear in their effect throughout their ranges of motion, and independent of one another in their effects. The geometries of the subset of the constrained controls and of its image in moment space are examined. A direct method of allocating these several controls is presented, that guarantees the maximum possible moment is generated within the constraints of the controls. The results are illustrated by an example problem involving three controls and two moments.

  1. Control rod drive

    SciTech Connect

    Hawke, Basil C.

    1986-01-01

    A control rod drive uses gravitational forces to insert one or more control rods upwardly into a reactor core from beneath the reactor core under emergency conditions. The preferred control rod drive includes a vertically movable weight and a mechanism operatively associating the weight with the control rod so that downward movement of the weight is translated into upward movement of the control rod. The preferred control rod drive further includes an electric motor for driving the control rods under normal conditions, an electrically actuated clutch which automatically disengages the motor during a power failure and a decelerator for bringing the control rod to a controlled stop when it is inserted under emergency conditions into a reactor core.

  2. Spacecraft stability and control

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1992-01-01

    The Earth's first artificial satellite, Sputnik 1, slowly tumbled in orbit. The first U.S. satellite, Explorer 1, also tumbled out of control. Today, satellite stability and control has become a higher priority. For a satellite design that is to have a life expectancy of 14 years, appropriate spacecraft flight control systems will be reviewed, stability requirements investigated, and an appropriate flight control system recommended in order to see the design process. Disturbance torques, including aerodynamic, magnetic, gravity gradient, solar, micrometeorite, debris, collision, and internal torques, will be assessed to quantify the disturbance environment so that the required compensating torques can be determined. The control torques, including passive versus active, momentum control, bias momentum, spin stabilization, dual spin, gravity gradient, magnetic, reaction wheels, control moment gyros, inertia augmentation techniques, three-axis control, and reaction control systems (RCSs), will be considered. Conditions for stability will also be considered.

  3. Embryonic cerebrospinal fluid regulates neuroepithelial survival, proliferation, and neurogenesis in chick embryos.

    PubMed

    Gato, Angel; Moro, J A; Alonso, M I; Bueno, D; De La Mano, A; Martín, C

    2005-05-01

    Early in development, the behavior of neuroepithelial cells is controlled by several factors, which act in a developmentally regulated manner. Diffusible factors are secreted locally by the neuroepithelium itself, although other nearby structures may also be involved. Evidence suggests a physiological role for the cerebrospinal fluid in the development of the brain. Here, using organotypic cultures of chick embryo neuroepithelial explants from the mesencephalon, we show that the neuroepithelium in vitro is not able to self-induce cell survival, replication, and neurogenesis. We also show that the embryonic cerebrospinal fluid (E-CSF) promotes neuroepithelial stem cell survival and induces proliferation and neurogenesis in mesencephalic explants. These data strongly suggest that E-CSF is involved in the regulation of neuroepithelial cells behavior, supporting the hypothesis that this fluid plays a key role during the early development of the central nervous system.

  4. Industrial linguistic control

    SciTech Connect

    King, R.E.; Karonis, F.

    1983-01-01

    The use of various types of controllers and control techniques for industrial process is discussed. An ongoing research and development project is reported on the application of intelligent linguistic controllers to processes in the cement industry in Greece which have, in the past, been controllable only by human operators. Prototype linguistic controllers using fuzzy logic have been implemented and tested on a rotary kiln precalciner flash furnace (3-input 3-output) and on a cement mill separator (3-input 2-output) with good results. Originally implemented on a supervisory minicomputer, the algorithms have been transferred to microcomputers which form the heart of this class of intelligent linguistic controllers. 6 references.

  5. Aircraft control system

    NASA Technical Reports Server (NTRS)

    Kendall, Greg T. (Inventor); Morgan, Walter R. (Inventor)

    2010-01-01

    A span-loaded, highly flexible flying wing, having horizontal control surfaces mounted aft of the wing on extended beams to form local pitch-control devices. Each of five spanwise wing segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other wing segments, to minimize inter-segment loads. Wing dihedral is controlled by separately controlling the local pitch-control devices consisting of a control surface on a boom, such that inboard and outboard wing segment pitch changes relative to each other, and thus relative inboard and outboard lift is varied.

  6. Robot welding process control

    NASA Technical Reports Server (NTRS)

    Romine, Peter L.

    1991-01-01

    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  7. Control system design method

    DOEpatents

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  8. CONTROL ROD DRIVE

    DOEpatents

    Chapellier, R.A.; Rogers, I.

    1961-06-27

    Accurate and controlled drive for the control rod is from an electric motor. A hydraulic arrangement is provided to balance a piston against which a control rod is urged by the application of fluid pressure. The electric motor drive of the control rod for normal operation is made through the aforementioned piston. In the event scramming is required, the fluid pressure urging the control rod against the piston is relieved and an opposite fluid pressure is applied. The lack of mechanical connection between the electric motor and control rod facilitates the scramming operation.

  9. Programmable Digital Controller

    NASA Technical Reports Server (NTRS)

    Wassick, Gregory J.

    2012-01-01

    An existing three-channel analog servo loop controller has been redesigned for piezoelectric-transducer-based (PZT-based) etalon control applications to a digital servo loop controller. This change offers several improvements over the previous analog controller, including software control over proportional-integral-derivative (PID) parameters, inclusion of other data of interest such as temperature and pressure in the control laws, improved ability to compensate for PZT hysteresis and mechanical mount fluctuations, ability to provide pre-programmed scanning and stepping routines, improved user interface, expanded data acquisition, and reduced size, weight, and power.

  10. Propulsion Controls, 1979. [air breathing engine control

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The state of the art of multivariable engine control is examined in order to determine future needs and problem areas and to establish the appropriate roles of government, industries, and universities in addressing these problems.

  11. Supervisory Control of Networked Control Systems

    DTIC Science & Technology

    2006-01-15

    consisting of 3 Koala robots [Lem06b]. The robots are controlled by MICA2 wireless processor modules. The robots communicate over the MICA2’s...preliminary documentation of a wireless autonomous robotic testbed. The system consists of 3 Koala (K-team Inc.) robots that are controlled by the MICA2...by this project. MICA-KoalaBot Hardware: The Koala robot is an autonomous wheeled vehicle that has 16 infrared (IR) proximity sensors around its

  12. MPC improves reformer control

    SciTech Connect

    Jung, C.S.; Noh, K.K.; Yi, S.; Kim, J.S.; Song, H.K.; Hyun, J.C.

    1995-04-01

    A model predictive control strategy was applied to a synthesis gas reformer of Samsung-BP Chemicals in Korea that produces carbon monoxide and hydrogen from naphtha. A strongly endothermic reaction occurs in a catalytic reformer, and reformer outlet temperature is considered to have the most significant effect on product composition. The newly developed reformer is known to be a cost-effective process operating at high reaction temperatures and low steam-to-carbon ratio, but its drawback is temperature control difficulty due to the use of offgas as a part of the fuel. Without smooth control of the reformer outlet temperature, stable operation of the downstream separation units cannot be expected. Therefore, it is a great challenge to apply a model predictive control technique for tight control of reformer outlet temperature. The paper describes model predictive control, the process advanced control project, computer system architecture, analysis of operating condition, control structure, sampling rate, and disturbance estimation.

  13. Multivariable Control Systems

    DTIC Science & Technology

    1968-01-01

    one). Examples abound of systems with numerous controlled variables, and the modern tendency is toward ever greater utilization of systems and plants of this kind. We call them multivariable control systems (MCS).

  14. Consciousness and cognitive control

    PubMed Central

    Kunde, Wilfried; Reuss, Heiko; Kiesel, Andrea

    2012-01-01

    The implementation or change of information processing routines, known as cognitive control, is traditionally believed to be closely linked to consciousness. It seems that we exert control over our behavior if we know the reasons for, and consequences of, doing so. Recent research suggests, however, that several behavioral phenomena that have been construed as instances of cognitive control can be prompted by events of which actors are not aware. Here we give a brief review of this research, discuss possible reasons for inconsistencies in the empirical evidence, and suggest some lines of future research. Specifically, we suggest to differentiate cognitive control evoked either because of explicit or because of implicit control cues. While the former type of control seems to work outside of awareness, the latter type of control seems to be restricted to consciously registered events that call for control. PMID:22419962

  15. Insensitive control technology development

    NASA Technical Reports Server (NTRS)

    Harvey, C. A.; Pope, R. E.

    1978-01-01

    THe investigation of two insensitive controller synthesis techniques was reported. The finite dimensional inverse approach produces a time varying insensitive controller and/or parameter identifier by constructing inverse functions derived from a finite number of input output pair relationships. The MD/IM concept relies on the information matrix theory that was developed in the estimation and identification field. The MD/IM synthesis technique is based on the hypothesis that minimizing the information matrix will reduce system identifiability and consequently system sensitivity to uncertain parameters. The controllers designed with both techniques were evaluated on a realistic C-5A aircraft flight control problem. Results indicate that the FDI controller is more suited to trajectory type problems because of its time varying nature. The MD/IM controller performed as well as the top-rated controllers of the initial effort and has direct application to aircraft flight control problems.

  16. Aeroelastic structural acoustic control.

    PubMed

    Clark, R L; Frampton, K D

    1999-02-01

    Static, constant-gain, output-feedback control compensators were designed to increase the transmission loss across a panel subjected to mean flow on one surface and a stationary, acoustic half-space on the opposite surface. The multi-input, multi-output control system was based upon the use of an array of colocated transducer pairs. The performance of the static-gain, output-feedback controller was compared to that of the full state-feedback controller using the same control actuator arrays, and was found to yield comparable levels of performance for practical limitations on control effort. Additionally, the resulting static compensators proved to be dissipative in nature, and thus the design varied little as a function of the aeroelastic coupling induced by the fluid-structure interaction under subsonic flow conditions. Several parametric studies were performed, comparing the effects of control-effort penalty as well as the number of transducer pairs used in the control system.

  17. Birth control pill - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100108.htm Birth control pill - series—Normal female anatomy To use the ... to produce a successful pregnancy. To prevent pregnancy, birth control pills affect how these organs normally function. Review ...

  18. Nutrient Control Seminars

    EPA Science Inventory

    These Nutrient Control Seminars will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). These seminars will present ...

  19. Nutrient Control Design Manual

    EPA Science Inventory

    The Nutrient Control Design Manual will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). This manual will present ...

  20. Controlling quantum bits

    NASA Astrophysics Data System (ADS)

    2010-08-01

    Can excitons be used to achieve scalable control of quantum light? Steffen Michaelis de Vasconcellos explained to Nature Photonics that the optoelectrical control of exciton qubits in quantum dots offers great promise.

  1. Solar Control design package

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information used in the evaluation of design of Solar Control's solar heating and cooling system controller and the Solarstat is given. Some of the information includes system performance specifications, design data brochures, and detailed design drawings.

  2. Scabies: Prevention and Control

    MedlinePlus

    ... Diagnostic Assistance [DPDx] Error processing SSI file Prevention & Control Recommend on Facebook Tweet Share Compartir When a ... avoid outbreaks. Institutional outbreaks can be difficult to control and require a rapid, aggressive, and sustained response. ...

  3. Adaptive Decentralized Control

    DTIC Science & Technology

    1985-04-01

    computational requirements and response time provide strong incentives for the use of distributed control architectures. The basic focus of our research is on...ADCON (for Adaptive Decentralized CONtrol) comes from the following observations about the current status of control theory . An important aspect of...decentralized control of completely known systems still has many unresolved issues and some basic problems are yet to be answered. Under these conditions

  4. Microtron Modelling and Control

    SciTech Connect

    Krist, Pavel; Bila, Jiri

    2010-01-05

    The article describes the design of the mathematical model and automatic control system of the microtron (high frequency cyclic electron accelerator). This type of accelerator was controlled manually till now. The critical values have been set up empirically on the basis of the previous operational experiences. The designed automatic control system with fuzzy controller should increase the accelerated electrons current value and improve the beam stability.

  5. System for controlling apnea

    DOEpatents

    Holzrichter, John F

    2015-05-05

    An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.

  6. Adaptive, predictive controller for optimal process control

    SciTech Connect

    Brown, S.K.; Baum, C.C.; Bowling, P.S.; Buescher, K.L.; Hanagandi, V.M.; Hinde, R.F. Jr.; Jones, R.D.; Parkinson, W.J.

    1995-12-01

    One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some remarkable capabilities in such non-linear applications as continuous stirred exothermic tank reactors and high-purity fractional distillation columns[3]. The controller is able not only to build an appropriate model from operating data but also to thin the network continuously so that the model adapts to changing plant conditions. The controller is discussed as well as its possible use in various of the difficult control problems that face this community.

  7. Reflective Database Access Control

    ERIC Educational Resources Information Center

    Olson, Lars E.

    2009-01-01

    "Reflective Database Access Control" (RDBAC) is a model in which a database privilege is expressed as a database query itself, rather than as a static privilege contained in an access control list. RDBAC aids the management of database access controls by improving the expressiveness of policies. However, such policies introduce new interactions…

  8. Finite Control in Korean

    ERIC Educational Resources Information Center

    Lee, Kum Young

    2009-01-01

    This thesis explores finite control in Korean. An overview of the previous studies of control shows that the mainstream literature on control has consistently argued that referential dependence between an overt matrix argument and an embedded null subject is characteristic of non-finite clauses which contain a PRO subject. Moreover, although some…

  9. Birth Control Pill

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Pill KidsHealth > For Teens > Birth Control Pill A A A What's in this article? ... español La píldora anticonceptiva What Is It? The birth control pill (also called "the Pill") is a daily ...

  10. Birth Control Patch

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch A A A What's in this article? ... Much Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...

  11. Birth Control Shot

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Shot KidsHealth > For Teens > Birth Control Shot A A A What's in this article? ... español La inyección anticonceptiva What Is It? The birth control shot is a long-acting form of progesterone, ...

  12. Numerical methods in control

    NASA Astrophysics Data System (ADS)

    Mehrmann, Volker; Xu, Hongguo

    2000-11-01

    We study classical control problems like pole assignment, stabilization, linear quadratic control and H[infinity] control from a numerical analysis point of view. We present several examples that show the difficulties with classical approaches and suggest reformulations of the problems in a more general framework. We also discuss some new algorithmic approaches.

  13. Spacecraft nonlinear control

    NASA Technical Reports Server (NTRS)

    Sheen, Jyh-Jong; Bishop, Robert H.

    1992-01-01

    The feedback linearization technique is applied to the problem of spacecraft attitude control and momentum management with control moment gyros (CMGs). The feedback linearization consists of a coordinate transformation, which transforms the system to a companion form, and a nonlinear feedback control law to cancel the nonlinear dynamics resulting in a linear equivalent model. Pole placement techniques are then used to place the closed-loop poles. The coordinate transformation proposed here evolves from three output functions of relative degree four, three, and two, respectively. The nonlinear feedback control law is presented. Stability in a neighborhood of a controllable torque equilibrium attitude (TEA) is guaranteed and this fact is demonstrated by the simulation results. An investigation of the nonlinear control law shows that singularities exist in the state space outside the neighborhood of the controllable TEA. The nonlinear control law is simplified by a standard linearization technique and it is shown that the linearized nonlinear controller provides a natural way to select control gains for the multiple-input, multiple-output system. Simulation results using the linearized nonlinear controller show good performance relative to the nonlinear controller in the neighborhood of the TEA.

  14. Control of Extrusion

    NASA Astrophysics Data System (ADS)

    Zhuromskii, V. M.

    2016-03-01

    The principle and engineering of a system for automatic control of the tension of the thread and the productivity of the process of extrusion of polyacrylonitrile fibers have been presented. The control system is based on the use of functional features of a modern frequency controlled electric drive.

  15. Birth Control Patch

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch Print A A A What's in this ... Much Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...

  16. Birth Control Shot

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Shot KidsHealth > For Teens > Birth Control Shot Print A A A What's in this ... español La inyección anticonceptiva What Is It? The birth control shot is a long-acting form of progesterone, ...

  17. Birth Control Pill

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Pill KidsHealth > For Teens > Birth Control Pill Print A A A What's in this ... español La píldora anticonceptiva What Is It? The birth control pill (also called "the Pill") is a daily ...

  18. Birth Control Ring

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Ring KidsHealth > For Teens > Birth Control Ring Print A A A What's in this ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ring ...

  19. CAS. Controlled Access Security

    SciTech Connect

    Martinez, B.; Pomeroy, G.

    1989-12-01

    The Security Alarm System is a data acquisition and control system which collects data from intrusion sensors and displays the information in a real-time environment for operators. The Access Control System monitors and controls the movement of personnel with the use of card readers and biometrics hand readers.

  20. Lithography overlay controller formulation

    NASA Astrophysics Data System (ADS)

    Bode, Christopher A.; Toprac, Anthony J.; Edwards, Richard D.; Edgar, Thomas F.

    2000-08-01

    Lithography overlay refers to the measurement of the alignment of successive patterns within the manufacture of semiconductor devices. Control of overlay has become of great importance in semiconductor manufacturing, as the tolerance for overlay error is continually shrinking in order to manufacture next-generation semiconductor products. Run-to-run control has become an attractive solution to many control problems within the industry, including overlay. The term run-to-run control refers to any automated procedure whereby recipe settings are updated between successive process runs in order to keep the process under control. The following discussion will present the formulation of such a controller by examining control of overlay. A brief introduction of overlay will be given, highlighting the control challenge overlay presents. A data management methodology that groups like processes together in order to improve controllability, referred to as control threads, will then be presented. Finally, a discussion of linear model predictive control will show its utility in feedback run-to-run control.

  1. Intermittent Control Systems

    ERIC Educational Resources Information Center

    Montgomery, Thomas L.; And Others

    1975-01-01

    The technique of intermittent control systems for air quality control as developed and used by the Tennessee Valley Authority is investigated. Although controversial, all Tennessee Valley Authority sulfur dioxide elimination programs are scheduled to be operational this year. Existing or anticipated intermittent control systems are identified. (BT)

  2. Embryonic blood-cerebrospinal fluid barrier formation and function

    PubMed Central

    Bueno, David; Parvas, Maryam; Hermelo, Ismaïl; Garcia-Fernàndez, Jordi

    2014-01-01

    During embryonic development and adult life, brain cavities and ventricles are filled with cerebrospinal fluid (CSF). CSF has attracted interest as an active signaling medium that regulates brain development, homeostasis and disease. CSF is a complex protein-rich fluid containing growth factors and signaling molecules that regulate multiple cell functions in the central nervous system (CNS). The composition and substance concentrations of CSF are tightly controlled. In recent years, it has been demonstrated that embryonic CSF (eCSF) has a key function as a fluid pathway for delivering diffusible signals to the developing brain, thus contributing to the proliferation, differentiation and survival of neural progenitor cells, and to the expansion and patterning of the brain. From fetal stages through to adult life, CSF is primarily produced by the choroid plexus. The development and functional activities of the choroid plexus and other blood–brain barrier (BBB) systems in adults and fetuses have been extensively analyzed. However, eCSF production and control of its homeostasis in embryos, from the closure of the anterior neuropore when the brain cavities become physiologically sealed, to the formation of the functional fetal choroid plexus, has not been studied in as much depth and remains open to debate. This review brings together the existing literature, some of which is based on experiments conducted by our research group, concerning the formation and function of a temporary embryonic blood–CSF barrier in the context of the crucial roles played by the molecules in eCSF. PMID:25389383

  3. Controls Considerations for Turbine Active Clearance Control

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.

    2004-01-01

    This presentation discusses active control of turbine tip clearance from a control systems perspective. It is a subset of charts that were presented at the 2003 meeting of the International Society of Air Breathing Engines which was held August 31 through September 5 in Cleveland, Ohio. The associated reference paper is cited at the end of the presentation. The presentation describes active tip clearance control research being conducted by NASA to improve turbine engine systems. The target application for this effort is commercial aircraft engines. However, it is believed that the technologies developed as part of this research will benefit a broad spectrum of current and future turbomachinery. The first part of the presentation discusses the concept of tip clearance, problems associated with it, and the benefits of controlling it. It lays out a framework for implementing tip clearance controls that enables the implementation to progress from purely analytical to hardware-in-the-loop to fully experimental. And it briefly discusses how the technologies developed will be married to the previously described ACC Test Rig for hardware-in-the-loop demonstrations. The final portion of the presentation, describes one of the key technologies in some detail by presenting equations and results for a functional dynamic model of the tip clearance phenomena. As shown, the model exhibits many of the clearance dynamics found in commercial gas turbine engines. However, initial attempts to validate the model identified limitations that are being addressed to make the model more realistic.

  4. Arbitrating Control of Control and Display Units

    NASA Technical Reports Server (NTRS)

    Sugden, Paul C.

    2007-01-01

    The ARINC 739 Switch is a computer program that arbitrates control of two multi-function control and display units (MCDUs) between (1) a commercial flight-management computer (FMC) and (2) NASA software used in research on transport aircraft. (MCDUs are the primary interfaces between pilots and FMCs on many commercial aircraft.) This program was recently redesigned into a software library that can be embedded in research application programs. As part of the redesign, this software was combined with software for creating custom pages of information to be displayed on a CDU. This software commands independent switching of the left (pilot s) and right (copilot s) MCDUs. For example, a custom CDU page can control the left CDU while the FMC controls the right CDU. The software uses menu keys to switch control of the CDU between the FMC or a custom CDU page. The software provides an interface that enables custom CDU pages to insert keystrokes into the FMC s CDU input interface. This feature allows the custom CDU pages to manipulate the FMC as if it were a pilot.

  5. Control of wastewater using multivariate control chart

    NASA Astrophysics Data System (ADS)

    Nugraha, Jaka; Fatimah, Is; Prabowo, Rino Galang

    2017-03-01

    Wastewater treatment is a crucial process in industry cause untreated or improper treatment of wastewater may leads some problems affecting to the other parts of environmental aspects. For many kinds of wastewater treatments, the parameters of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and the Total Suspend Solid (TSS) are usual parameters to be controlled as a standard. In this paper, the application of multivariate Hotteling T2 Individual was reported to control wastewater treatment. By using wastewater treatment data from PT. ICBP, east Java branch, while the fulfillment of quality standards are based on East Java Governor Regulation No. 72 Year 2013 on Standards of Quality of Waste Water Industry and / or Other Business Activities. The obtained results are COD and TSS has a correlation with BOD values with the correlation coefficient higher than 50%, and it is is also found that influence of the COD and TSS to BOD values are 82% and 1.9% respectively. Based on Multivariate control chart Individual T2 Hotteling, it is found that BOD-COD and BOD-TSS are each one subgroup that are outside the control limits. Thus, it can be said there is a process that is not multivariate controlled, but univariately the variables of BOD, COD and TSS are within specification (standard quality) that has been determined.

  6. Magnetically Controlled Variable Transformer

    NASA Technical Reports Server (NTRS)

    Kleiner, Charles T.

    1994-01-01

    Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

  7. Intelligent Control Systems Research

    NASA Technical Reports Server (NTRS)

    Loparo, Kenneth A.

    1994-01-01

    Results of a three phase research program into intelligent control systems are presented. The first phase looked at implementing the lowest or direct level of a hierarchical control scheme using a reinforcement learning approach assuming no a priori information about the system under control. The second phase involved the design of an adaptive/optimizing level of the hierarchy and its interaction with the direct control level. The third and final phase of the research was aimed at combining the results of the previous phases with some a priori information about the controlled system.

  8. Control and optimization system

    DOEpatents

    Xinsheng, Lou

    2013-02-12

    A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

  9. STOVL Control Integration Program

    NASA Technical Reports Server (NTRS)

    Weiss, C.; Mcdowell, P.; Watts, S.

    1994-01-01

    An integrated flight/propulsion control for an advanced vector thrust supersonic STOVL aircraft, was developed by Pratt & Whitney and McDonnell Douglas Aerospace East. The IFPC design was based upon the partitioning of the global requirements into flight control and propulsion control requirements. To validate the design, aircraft and engine models were also developed for use on a NASA Ames piloted simulator. Different flight control implementations, evaluated for their handling qualities, are documented in the report along with the propulsion control, engine model, and aircraft model.

  10. Water heater control module

    SciTech Connect

    Hammerstrom, Donald J

    2013-11-26

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  11. Recursive Deadbeat Controller Design

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan; Phan, Minh Q.

    1997-01-01

    This paper presents a recursive algorithm for a deadbeat predictive controller design. The method combines together the concepts of system identification and deadbeat controller designs. It starts with the multi-step output prediction equation and derives the control force in terms of past input and output time histories. The formulation thus derived satisfies simultaneously system identification and deadbeat controller design requirements. As soon as the coefficient matrices are identified satisfying the output prediction equation, no further work is required to compute the deadbeat control gain matrices. The method can be implemented recursively just as any typical recursive system identification techniques.

  12. Intelligent Welding Controller

    NASA Technical Reports Server (NTRS)

    Cook, George E.; Kumar, Ramaswamy; Prasad, Tanuji; Andersen, Kristinn; Barnett, Robert J.

    1989-01-01

    Control system adapts to changing design requirements and operating conditions. Proposed control system for gas/tungsten arc welding requires only that operator specifies such direct parameters of welds as widths and depths of penetration. In control system for robotic welder, components and functions intimately connected with welding process assigned to controller domain. More general functions assigned to supervisor domain. Initial estimate of indirect parameters of welding process applied to system only at beginning of weld (t=0); after start of welding, outputs from multivariable controller takes place of estimate.

  13. Intelligent flight control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1993-01-01

    The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.

  14. Controls and guidance research

    NASA Technical Reports Server (NTRS)

    Homaifar, Abdollah; Dunn, Derome; Song, Yong-Duan; Lai, Steven H.-Y.

    1992-01-01

    The objectives of the control group are concentrated on research and education. The control problem of the hypersonic space vehicle represents an important and challenging issue in aerospace engineering. The work described in this report is part of our effort in developing advanced control strategies for such a system. In order to achieve the objectives stated in the NASA-CORE proposal, the tasks were divided among the group based upon their educational expertise. Within the educational component we are offering a Linear Systems and Control course for students in electrical and mechanical engineering. Also, we are proposing a new course in Digital Control Systems with a corresponding laboratory.

  15. [Controlling instruments in radiology].

    PubMed

    Maurer, M

    2013-10-01

    Due to the rising costs and competitive pressures radiological clinics and practices are now facing, controlling instruments are gaining importance in the optimization of structures and processes of the various diagnostic examinations and interventional procedures. It will be shown how the use of selected controlling instruments can secure and improve the performance of radiological facilities. A definition of the concept of controlling will be provided. It will be shown which controlling instruments can be applied in radiological departments and practices. As an example, two of the controlling instruments, material cost analysis and benchmarking, will be illustrated.

  16. SPS antenna pointing control

    NASA Technical Reports Server (NTRS)

    Hung, J. C.

    1980-01-01

    The pointing control of a microwave antenna of the Satellite Power System was investigated emphasizing: (1) the SPS antenna pointing error sensing method; (2) a rigid body pointing control design; and (3) approaches for modeling the flexible body characteristics of the solar collector. Accuracy requirements for the antenna pointing control consist of a mechanical pointing control accuracy of three arc-minutes and an electronic phased array pointing accuracy of three arc-seconds. Results based on the factors considered in current analysis, show that the three arc-minute overall pointing control accuracy can be achieved in practice.

  17. Conscious Control over Action.

    PubMed

    Shepherd, Joshua

    2015-06-01

    The extensive involvement of nonconscious processes in human behaviour has led some to suggest that consciousness is much less important for the control of action than we might think. In this article I push against this trend, developing an understanding of conscious control that is sensitive to our best models of overt (that is, bodily) action control. Further, I assess the cogency of various zombie challenges-challenges that seek to demote the importance of conscious control for human agency. I argue that though nonconscious contributions to action control are evidently robust, these challenges are overblown.

  18. CONTROL FOR NEUTRONIC REACTOR

    DOEpatents

    Lichtenberger, H.V.; Cameron, R.A.

    1959-03-31

    S>A control rod operating device in a nuclear reactor of the type in which the control rod is gradually withdrawn from the reactor to a position desired during stable operation is described. The apparatus is comprised essentially of a stop member movable in the direction of withdrawal of the control rod, a follower on the control rod engageable with the stop and means urging the follower against the stop in the direction of withdrawal. A means responsive to disengagement of the follower from the stop is provided for actuating the control rod to return to the reactor shut-down position.

  19. Conscious Control over Action

    PubMed Central

    Shepherd, Joshua

    2015-01-01

    The extensive involvement of nonconscious processes in human behaviour has led some to suggest that consciousness is much less important for the control of action than we might think. In this article I push against this trend, developing an understanding of conscious control that is sensitive to our best models of overt (that is, bodily) action control. Further, I assess the cogency of various zombie challenges—challenges that seek to demote the importance of conscious control for human agency. I argue that though nonconscious contributions to action control are evidently robust, these challenges are overblown. PMID:26113753

  20. Modeling and control of thermostatically controlled loads

    SciTech Connect

    Backhaus, Scott N; Sinitsyn, Nikolai; Kundu, S.; Hiskens, I.

    2011-01-04

    As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for the aggregate power response of a homogeneous population of TCLs to uniform variation of all TCL setpoints. A linearized model of the response is derived, and a linear quadratic regulator (LQR) has been designed. Using the TCL setpoint as the control input, the LQR enables aggregate power to track reference signals that exhibit step, ramp and sinusoidal variations. Although much of the work assumes a homogeneous population of TCLs with deterministic dynamics, we also propose a method for probing the dynamics of systems where load characteristics are not well known.

  1. Integrated Biological Control

    SciTech Connect

    JOHNSON, A.R.

    2003-10-09

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects, and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (a priori) or in response to existing contamination spread (a posteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and a priori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, a posteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response.

  2. Integrated Biological Control

    SciTech Connect

    JOHNSON, A.R.

    2002-09-01

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response.

  3. Controlling chaos faster

    SciTech Connect

    Bick, Christian; Kolodziejski, Christoph; Timme, Marc

    2014-09-01

    Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period.

  4. On the Switching Control

    NASA Astrophysics Data System (ADS)

    Balas, Valentina E.; Balas, Marius M.

    2009-04-01

    The paper is discussing the measures able to reject the instability that may unexpectedly appear in particular conditions, in switching controllers applications. The switching controllers' effect is explained by the combined effects of the unsuitable choice of the switching moments (in the first or third quadrants of the phase trajectory of the switching error) and of the temporal aliasing that can distort the digital control systems when the sampling rate is close to the frequency of the oscillations that are produced by the commutation. The correct switching moments are located into the second and fourth quadrants of the phase trajectory of the switching error, but an active preparation of the commutation may be simply achieved by using a tracking controller, that is driving the output of open loop controller to follow the output of the close loop controller, permanently minimizing the switching error. Simulations issued from a dc driver speed controller and from an aircraft are provided.

  5. CRUCIFORM CONTROL ROD JOINT

    DOEpatents

    Thorp, A.G. II

    1962-08-01

    An invention is described which relates to nuclear reactor control rod components and more particularly to a joint between cruciform control rod members and cruciform control rod follower members. In one embodiment this invention provides interfitting crossed arms at adjacent ends of a control rod and its follower in abutting relation. This holds the members against relative opposite longitudinal movement while a compression member keys the arms against relative opposite rotation around a common axis. Means are also provided for centering the control rod and its follower on a common axis and for selectively releasing the control rod from its follower for the insertion of a replacement of the control rod and reuse of the follower. (AEC)

  6. Controlling chaos faster.

    PubMed

    Bick, Christian; Kolodziejski, Christoph; Timme, Marc

    2014-09-01

    Predictive feedback control is an easy-to-implement method to stabilize unknown unstable periodic orbits in chaotic dynamical systems. Predictive feedback control is severely limited because asymptotic convergence speed decreases with stronger instabilities which in turn are typical for larger target periods, rendering it harder to effectively stabilize periodic orbits of large period. Here, we study stalled chaos control, where the application of control is stalled to make use of the chaotic, uncontrolled dynamics, and introduce an adaptation paradigm to overcome this limitation and speed up convergence. This modified control scheme is not only capable of stabilizing more periodic orbits than the original predictive feedback control but also speeds up convergence for typical chaotic maps, as illustrated in both theory and application. The proposed adaptation scheme provides a way to tune parameters online, yielding a broadly applicable, fast chaos control that converges reliably, even for periodic orbits of large period.

  7. Robust Control Design for Flight Control

    DTIC Science & Technology

    1989-07-01

    to achieve desired performance over the full flight envelope when linear feedback is employed. Exact linearization methods [48] provide means for...designing nonlinear feedback laws which satisfy these requirements. However, exact linearization is not always compatible with control authority...specific situations. The most promising approaches appear to be those associated with methods of exact linearization . This procedure is based on some

  8. Flight control actuation system

    NASA Technical Reports Server (NTRS)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2006-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  9. Unpacking Self-Control

    PubMed Central

    Duckworth, Angela; Steinberg, Laurence

    2014-01-01

    Self-controlled behavior refers to actions aligned with valued, longer-term goals in the face of conflicting impulses to seek immediate gratification. In this article, we argue that the psychological processes that contribute to self-controlled behavior can be grouped into two functionally distinct categories: Volitional processes facilitate self-controlled behavior and include executive functions as well as learned metacognitive strategies like planning, attention deployment, and psychological distancing. In contrast, impulsigenic processes undermine self-controlled behavior and include reward sensitivity, sensation seeking, and domain-specific cravings. A disproportionate amount of research has addressed the former at the expense of understanding individual and developmental differences in the latter. This imbalance is now being rectified. Distinguishing between self-controlled behavior and its antecedent psychological processes helps illuminate normative developmental changes in self-control and points to directions for measurement and intervention. PMID:25821515

  10. Advanced Aerodynamic Control Effectors

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.

    1999-01-01

    A 1990 research program that focused on the development of advanced aerodynamic control effectors (AACE) for military aircraft has been reviewed and summarized. Data are presented for advanced planform, flow control, and surface contouring technologies. The data show significant increases in lift, reductions in drag, and increased control power, compared to typical aerodynamic designs. The results presented also highlighted the importance of planform selection in the design of a control effector suite. Planform data showed that dramatic increases in lift (greater than 25%) can be achieved with multiple wings and a sawtooth forebody. Passive porosity and micro drag generator control effector data showed control power levels exceeding that available from typical effectors (moving surfaces). Application of an advanced planform to a tailless concept showed benefits of similar magnitude as those observed in the generic studies.

  11. Fuzzy logic controller optimization

    DOEpatents

    Sepe, Jr., Raymond B; Miller, John Michael

    2004-03-23

    A method is provided for optimizing a rotating induction machine system fuzzy logic controller. The fuzzy logic controller has at least one input and at least one output. Each input accepts a machine system operating parameter. Each output produces at least one machine system control parameter. The fuzzy logic controller generates each output based on at least one input and on fuzzy logic decision parameters. Optimization begins by obtaining a set of data relating each control parameter to at least one operating parameter for each machine operating region. A model is constructed for each machine operating region based on the machine operating region data obtained. The fuzzy logic controller is simulated with at least one created model in a feedback loop from a fuzzy logic output to a fuzzy logic input. Fuzzy logic decision parameters are optimized based on the simulation.

  12. Designing Genetic Feedback Controllers.

    PubMed

    Harris, Andreas W K; Dolan, James A; Kelly, Ciarán L; Anderson, James; Papachristodoulou, Antonis

    2015-08-01

    By incorporating feedback around systems we wish to manipulate, it is possible to improve their performance and robustness properties to meet pre-specified design objectives. For decades control engineers have been successfully implementing feedback controllers for complex mechanical and electrical systems such as aircraft and sports cars. Natural biological systems use feedback extensively for regulation and adaptation but apart from the most basic designs, there is no systematic framework for designing feedback controllers in Synthetic Biology. In this paper we describe how classical approaches from linear control theory can be used to close the loop. This includes the design of genetic circuits using feedback control and the presentation of a biological phase lag controller.

  13. Flight control actuation system

    NASA Technical Reports Server (NTRS)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2004-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  14. Chimpanzee Cognitive Control

    PubMed Central

    Beran, Michael J.

    2015-01-01

    Cognitive control processes are a feature of human cognition. Recent comparative tests have shown that some nonhuman animals also might share aspects of cognitive control with humans. Two of the executive processes that constitute cognitive control are metacognition and self-control, and recent experiments with chimpanzees are described that demonstrate metacognitive monitoring and control when these animals engage in an information-seeking task. Chimpanzees also show strategic responding in a self-control task by exhibiting self-distraction as an aid to delay of gratification. These demonstrations indicate continuity with similar human cognitive capacities, and the performances of chimpanzees in these kinds of tests have implications for considering the nature of the intelligence of these animals. PMID:26478660

  15. Nuclear reactor control

    DOEpatents

    Cawley, William E.; Warnick, Robert F.

    1982-01-01

    1. In a nuclear reactor incorporating a plurality of columns of tubular fuel elements disposed in horizontal tubes in a mass of graphite wherein water flows through the tubes to cool the fuel elements, the improvement comprising at least one control column disposed in a horizontal tube including fewer fuel elements than in a normal column of fuel elements and tubular control elements disposed at both ends of said control column, and means for varying the horizontal displacement of the control column comprising a winch at the upstream end of the control column and a cable extending through the fuel and control elements and attached to the element at the downstream end of the column.

  16. Physiological and genetic responses of bacteria to osmotic stress.

    PubMed Central

    Csonka, L N

    1989-01-01

    The capacity of organisms to respond to fluctuations in their osmotic environments is an important physiological process that determines their abilities to thrive in a variety of habitats. The primary response of bacteria to exposure to a high osmotic environment is the accumulation of certain solutes, K+, glutamate, trehalose, proline, and glycinebetaine, at concentrations that are proportional to the osmolarity of the medium. The supposed function of these solutes is to maintain the osmolarity of the cytoplasm at a value greater than the osmolarity of the medium and thus provide turgor pressure within the cells. Accumulation of these metabolites is accomplished by de novo synthesis or by uptake from the medium. Production of proteins that mediate accumulation or uptake of these metabolites is under osmotic control. This review is an account of the processes that mediate adaptation of bacteria to changes in their osmotic environment. PMID:2651863

  17. Computer aided manipulator control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.; Zawacki, R. L.

    1980-01-01

    This paper describes the hardware and software system of a dedicated mini- and microcomputer network developed at the JPL teleoperator project to aid the operator in real-time control of remote manipulators. The operator can be in series or in parallel with the control computer during operation. The purpose of the project is to develop, demonstrate and evaluate advanced supervisory control concepts and techniques for space applications. The paper concludes with a brief outline of future development plans and issues.

  18. Adaptive hierarchical fuzzy controller

    SciTech Connect

    Raju, G.V.S.; Jun Zhou

    1993-07-01

    A methodology for designing adaptive hierarchical fuzzy controllers is presented. In order to evaluate this concept, several suitable performance indices were developed and converted to linguistic fuzzy variables. Based on those variables, a supervisory fuzzy rule set was constructed and used to change the parameters of a hierarchical fuzzy controller to accommodate the variations of system parameters. The proposed algorithm was used in feedwater flow control to a steam generator. Simulation studies are presented that illustrate the effectiveness of the approach

  19. Supervisory control systems

    NASA Technical Reports Server (NTRS)

    Sheridan, T. B.

    1974-01-01

    The various functions of a computer are considered that serve in connecting the man, with his displays and controls, to an external environment, manipulator activators and the interoceptors that are in the actuators, and to the interosensors and the motors or the actuators to drive the sensors. Projected is an improved exoskeleton mechanism with computer control and some supervisory control that may give a quadriplegic the ability to walk and run around.

  20. Modular Battery Controller

    NASA Technical Reports Server (NTRS)

    Button, Robert M (Inventor); Gonzalez, Marcelo C (Inventor)

    2017-01-01

    Some embodiments of the present invention describe a battery including a plurality of master-less controllers. Each controller is operatively connected to a corresponding cell in a string of cells, and each controller is configured to bypass a fraction of current around the corresponding cell when the corresponding cell has a greater charge than one or more other cells in the string of cells.

  1. Rotor control system

    NASA Technical Reports Server (NTRS)

    Bradford, Michael P. (Inventor); Maciolek, Joseph R. (Inventor)

    1987-01-01

    A helicopter rotor control system (13) including a stop azimuth controller (32) for establishing the value of a deceleration command (15') to a deceleration controller (23), a transition azimuth predictor (41) and a position reference generator (55), which are effective during the last revolution of said rotor (14) to establish a correction indication (38) to adjust the deceleration command (15') to ensure that one of the rotor blades (27) stops at a predetermined angular position.

  2. JPRS Report, Arms Control

    DTIC Science & Technology

    2007-11-02

    dangerous because the measure of control by central political organs of the state over conventional weapons and their military use is substan...It is always under the control and guidance of governments of the interested parties, it is the most manageable and has the least inertia. It...JPRS-TAC-89-001 10 JANUARY 1989 —JPRS Report— Arms Control nTSTRJBUTlON STATEMfcwTA Approved for public release; Distribution Unlimited n

  3. Innovation for Pollution Control

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Kinetic Controls Inc.'s refuse-fired steam generating facility led to the development of an air pollution equipment control device. The device is currently marketed by two NASA/Langley Research Center employees. It automatically senses and compensates for the changes in smoke composition when refuse is used as a fuel by adjusting the precipitator's voltage and current to permit maximum collection of electrically charged dust particles. The control adapts to any electrostatic precipitator and should have extensive commercial applications.

  4. Proteome analysis of chick embryonic cerebrospinal fluid.

    PubMed

    Parada, Carolina; Gato, Angel; Aparicio, Mariano; Bueno, David

    2006-01-01

    During early stages of embryo development, the brain cavity is filled with embryonic cerebrospinal fluid (E-CSF), a complex fluid containing different protein fractions that contributes to the regulation of the survival, proliferation and neurogenesis of the neuroectodermal stem cells. Using 2-DE, protein sequencing and database searches, we identified and analyzed the proteome of the E-CSF from chick embryos (Gallus gallus). We identified 26 different gene products, including proteins related to the extracellular matrix, proteins associated with the regulation of osmotic pressure and metal transport, proteins related to cell survival, MAP kinase activators, proteins involved in the transport of retinol and vitamin D, antioxidant and antimicrobial proteins, intracellular proteins and some unknown proteins. Most of these gene products are involved in the regulation of developmental processes during embryogenesis in systems other than E-CSF. Interestingly, 14 of them are also present in adult human CSF proteome, and it has been reported that they are altered in the CSF of patients suffering neurodegenerative diseases and/or neurological disorders. Understanding these molecules and the mechanisms they control during embryonic neurogenesis is a key contribution to the general understanding of CNS development, and may also contribute to greater knowledge of these human diseases.

  5. Bimodality in Network Control

    NASA Astrophysics Data System (ADS)

    Jia, Tao; Liu, Yang-Yu; Posfai, Marton; Slotine, Jean-Jacques; Barabasi, Albert-Laszlo

    2013-03-01

    Controlling complex systems is a fundamental challenge of network science. Recent tools enable us to identify the minimum driver nodes, from which we can control a system. They also indicate a multiplicity of minimum driver node sets (MDS's): multiple combinations of the same number of nodes can achieve control over the system. This multiplicity allows us to classify individual nodes as critical if they are involved in all control configurations, intermittent if they occasionally act as driver nodes and redundant if they do not play any role in control. We develop computational and analytical framework analyzing nodes in each category in both model and real networks. We find that networks with identical degree distribution can be in two distinct control modes, ``centralized'' or ``distributed'', with drastic change on the role of each node in maintaining the controllability and orders of magnitude difference in the number of MDS's. In analyzing both model and real networks, we find that the two modes can be inferred directly from the network's degree distribution. Finally we show that the two control modes can be switched by small structural perturbations, leading to potential applications of control theory in real systems.

  6. Control system design guide

    SciTech Connect

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  7. Detonation command and control

    DOEpatents

    Mace, Jonathan L.; Seitz, Gerald J.; Echave, John A.; Le Bas, Pierre-Yves

    2015-11-10

    The detonation of one or more explosive charges and propellant charges by a detonator in response to a fire control signal from a command and control system comprised of a command center and instrumentation center with a communications link therebetween. The fire control signal is selectively provided to the detonator from the instrumentation center if plural detonation control switches at the command center are in a fire authorization status, and instruments, and one or more interlocks, if included, are in a ready for firing status. The instrumentation and command centers are desirably mobile, such as being respective vehicles.

  8. Optimal control computer programs

    NASA Technical Reports Server (NTRS)

    Kuo, F.

    1992-01-01

    The solution of the optimal control problem, even with low order dynamical systems, can usually strain the analytical ability of most engineers. The understanding of this subject matter, therefore, would be greatly enhanced if a software package existed that could simulate simple generic problems. Surprisingly, despite a great abundance of commercially available control software, few, if any, address the part of optimal control in its most generic form. The purpose of this paper is, therefore, to present a simple computer program that will perform simulations of optimal control problems that arise from the first necessary condition and the Pontryagin's maximum principle.

  9. The ISOLDE control system

    NASA Astrophysics Data System (ADS)

    Deloose, I.; Pace, A.

    1994-12-01

    The two CERN isotope separators named ISOLDE have been running on the new Personal Computer (PC) based control system since April 1992. The new architecture that makes heavy use of the commercial software and hardware of the PC market has been implemented on the 1700 geographically distributed control channels of the two separators and their experimental area. Eleven MSDOS Intel-based PCs with approximately 80 acquisition and control boards are used to access the equipment and are controlled from three PCs running Microsoft Windows used as consoles through a Novell Local Area Network. This paper describes the interesting solutions found and discusses the reduced programming workload and costs that have been obtained.

  10. SSRF Beamline Control System

    SciTech Connect

    Zheng, L. F.; Liu, P.; Zhang, Z. H.; Hu, C.; Mi, Q. R.; Wu, Y. F.; Gong, P. R.; Zhu, Z. X.; Li, Z.

    2010-06-23

    There are seven beamlines in the Phase-I of SSRF. Five of them are equipped with Insertion Devices, while two with Bending Magnets. The beamline control system is based on the standard hardware and software architecture. The VME(PowerPC) with VxWorks is used for motion control, while the personal computers with Scientific Linux are the front end controllers of equipment protection and personnel safety systems. The control software is developed under EPICS which makes various experimental programs of Blu-Ice, LabView, VC and SPEC conveniently access Monochromators, mirror chambers and other optical components.

  11. Cooled, temperature controlled electrometer

    DOEpatents

    Morgan, John P.

    1992-08-04

    A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

  12. Cooled, temperature controlled electrometer

    DOEpatents

    Morgan, John P.

    1992-01-01

    A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

  13. MOSFET Power Controller

    NASA Technical Reports Server (NTRS)

    Mitchell, J.; Jones, K.

    1986-01-01

    High current and voltage controlled remotely. Remote Power Conroller includes two series-connected banks of parallel-connected MOSFET's to withstand high current and voltage. Voltage sharing between switch banks, low-impedance, gate-drive circuits used. Provided controlled range for turn on. Individually trimmable to insure simultaneous switching within few nanoseconds during both turn on and turn off. Control circuit for each switch bank and over-current trip circuit float independently and supplied power via transformer T1 from inverter. Control of floating stages by optocouplers.

  14. Satellite attitude control simulations

    NASA Technical Reports Server (NTRS)

    Debra, D. B.; Powell, J. D.

    1973-01-01

    Work was conducted to develop an extremely low drift rate gyroscope and a very precise star tracker. A proposed relativity satellite will measure very accurately the theoretically predicted 'relativistic' precession of the gyroscope relative to an inertial reference frame provided by the star tracker. Aspects of precision spinning attitude control are discussed together with questions of gyro operation, and the hopping mode for lunar transportation. For the attitude control system of the lunar hopper, a number of control laws were investigated. The studies indicated that some suboptimal controls should be adequate for the system.

  15. Optimal Linear Control.

    DTIC Science & Technology

    1979-12-01

    OPTIMAL LINEAR CONTROL C.A. HARVEY M.G. SAFO NOV G. STEIN J.C. DOYLE HONEYWELL SYSTEMS & RESEARCH CENTER j 2600 RIDGWAY PARKWAY j [ MINNEAPOLIS...RECIPIENT’S CAT ALC-’ W.IMIJUff’? * J~’ CR2 15-238-4F TP P EI)ŕll * (~ Optimal Linear Control ~iOGRPR UBA m a M.G Lnar o Con_ _ _ _ _ _ R PORT__ _ _ I RE...Characterizations of optimal linear controls have been derived, from which guides for selecting the structure of the control system and the weights in

  16. Helicopter high gain control

    NASA Technical Reports Server (NTRS)

    Cunningham, T. B.; Nunn, E. C.

    1979-01-01

    High gain control is explored through a design study of the CH-47B helicopter. The plans are designed to obtain the maximum bandwidth possible given the hardware constraints. Controls are designed with modal control theory to specific bandwidths and closed loop mode shapes. Comparisons are made to an earlier complementary filter approach. Bandwidth improvement by removal of limitations is explored in order to establish hardware and mechanization options. Improvements in the pitch axis control system and in the rate gyro sensor noise characteristics in all axes are discussed. The use of rotor state feedback is assessed.

  17. Controlled wind motor

    SciTech Connect

    Boswell, F.A.

    1983-12-27

    A mechanical sail including a rotatable mast, the mast including a top vane mount and a bottom vane mount, the mounts being spaced from each other on the mast and rotatable therewith, a series of rotatable vanes spaced from and surrounding the mast and supported by and between the mounts, cam operaters extending between the mounts and connected to the vanes for controlling the rotation of the vanes, a first controller associated with the mast below the bottom vane mount for controlling the cam operators, the first controller being movable vertically with respect to the mast, a second controller for moving the first controller vertically with respect to the mast, the vanes being flexible and bowed outwardly, the bottom vane mount being movable with respect to the mast and connected to the second controller whereby when the second controller is operated, the bottom vane mount will move toward the top vane mount causing the vanes to bow outwardly at a desired arc and whereby when the first controller is moved, the vanes are caused to rotate to the desired angle of attack with respect to wind velocity and direction. When the sail is connected to a motor drive, the vessel may be driven forward or rearward depending on the angle of attack of the vanes through 180/sup 0/.

  18. Detonation command and control

    DOEpatents

    Mace, Jonathan L.; Seitz, Gerald J.; Echave, John A.; Le Bas, Pierre-Yves

    2016-05-31

    The detonation of one or more explosive charges and propellant charges by a detonator in response to a fire control signal from a command and control system comprised of a command center and instrumentation center with a communications link there between. The fire control signal is selectively provided to the detonator from the instrumentation center if plural detonation control switches at the command center are in a fire authorization status, and instruments, and one or more interlocks, if included, are in a ready for firing status. The instrumentation and command centers are desirably mobile, such as being respective vehicles.

  19. Device Oriented Project Controller

    SciTech Connect

    Dalesio, Leo; Kraimer, Martin

    2013-11-20

    This proposal is directed at the issue of developing control systems for very large HEP projects. A de-facto standard in accelerator control is the Experimental Physics and Industrial Control System (EPICS), which has been applied successfully to many physics projects. EPICS is a channel based system that requires that each channel of each device be configured and controlled. In Phase I, the feasibility of a device oriented extension to the distributed channel database was demonstrated by prototyping a device aware version of an EPICS I/O controller that functions with the current version of the channel access communication protocol. Extensions have been made to the grammar to define the database. Only a multi-stage position controller with limit switches was developed in the demonstration, but the grammar should support a full range of functional record types. In phase II, a full set of record types will be developed to support all existing record types, a set of process control functions for closed loop control, and support for experimental beam line control. A tool to configure these records will be developed. A communication protocol will be developed or extensions will be made to Channel Access to support introspection of components of a device. Performance bench marks will be made on both communication protocol and the database. After these records and performance tests are under way, a second of the grammar will be undertaken.

  20. Control of robot dynamics using acceleration control

    NASA Technical Reports Server (NTRS)

    Workman, G. L.; Prateru, S.; Li, W.; Hinman, Elaine

    1992-01-01

    Acceleration control of robotic devices can provide improvements to many space-based operations using flexible manipulators and to ground-based operations requiring better precision and efficiency than current industrial robots can provide. This paper reports on a preliminary study of acceleration measurement on robotic motion during parabolic flights on the NASA KC-135 and a parallel study of accelerations with and without gravity arising from computer simulated motions using TREETOPS software.

  1. Controls for space structures

    NASA Astrophysics Data System (ADS)

    Balas, Mark

    1991-11-01

    Assembly and operation of large space structures (LSS) in orbit will require robot-assisted docking and berthing of partially-assembled structures. These operations require new solutions to the problems of controls. This is true because of large transient and persistent disturbances, controller-structure interaction with unmodeled modes, poorly known structure parameters, slow actuator/sensor dynamical behavior, and excitation of nonlinear structure vibrations during control and assembly. For on-orbit assembly, controllers must start with finite element models of LSS and adapt on line to the best operating points, without compromising stability. This is not easy to do, since there are often unmodeled dynamic interactions between the controller and the structure. The indirect adaptive controllers are based on parameter estimation. Due to the large number of modes in LSS, this approach leads to very high-order control schemes with consequent poor stability and performance. In contrast, direct model reference adaptive controllers operate to force the LSS to track the desirable behavior of a chosen model. These schemes produce simple control algorithms which are easy to implement on line. One problem with their use for LSS has been that the model must be the same dimension as the LSS - i.e., quite large. A control theory based on the command generator tracker (CGT) ideas of Sobel, Mabins, Kaufman and Wen, Balas to obtain very low-order models based on adaptive algorithms was developed. Closed-loop stability for both finite element models and distributed parameter models of LSS was proved. In addition, successful numerical simulations on several LSS databases were obtained. An adaptive controller based on our theory was also implemented on a flexible robotic manipulator at Martin Marietta Astronautics. Computation schemes for controller-structure interaction with unmodeled modes, the residual mode filters or RMF, were developed. The RMF theory was modified to compensate

  2. Controls for space structures

    NASA Technical Reports Server (NTRS)

    Balas, Mark

    1991-01-01

    Assembly and operation of large space structures (LSS) in orbit will require robot-assisted docking and berthing of partially-assembled structures. These operations require new solutions to the problems of controls. This is true because of large transient and persistent disturbances, controller-structure interaction with unmodeled modes, poorly known structure parameters, slow actuator/sensor dynamical behavior, and excitation of nonlinear structure vibrations during control and assembly. For on-orbit assembly, controllers must start with finite element models of LSS and adapt on line to the best operating points, without compromising stability. This is not easy to do, since there are often unmodeled dynamic interactions between the controller and the structure. The indirect adaptive controllers are based on parameter estimation. Due to the large number of modes in LSS, this approach leads to very high-order control schemes with consequent poor stability and performance. In contrast, direct model reference adaptive controllers operate to force the LSS to track the desirable behavior of a chosen model. These schemes produce simple control algorithms which are easy to implement on line. One problem with their use for LSS has been that the model must be the same dimension as the LSS - i.e., quite large. A control theory based on the command generator tracker (CGT) ideas of Sobel, Mabins, Kaufman and Wen, Balas to obtain very low-order models based on adaptive algorithms was developed. Closed-loop stability for both finite element models and distributed parameter models of LSS was proved. In addition, successful numerical simulations on several LSS databases were obtained. An adaptive controller based on our theory was also implemented on a flexible robotic manipulator at Martin Marietta Astronautics. Computation schemes for controller-structure interaction with unmodeled modes, the residual mode filters or RMF, were developed. The RMF theory was modified to compensate

  3. Compact, Reliable EEPROM Controller

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Kleyner, Igor

    2010-01-01

    A compact, reliable controller for an electrically erasable, programmable read-only memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells. Inadvertent writes pose risks of loss of reliability in the original space-flight application and could pose such risks in other applications. Prior EEPROM controllers are large and complex and do not provide all reasonable protections (in many cases, few or no protections) against inadvertent writes. In contrast, the present controller provides several layers of protection against inadvertent writes. The controller also incorporates a write-time monitor, enabling determination of trends in the performance of an EEPROM through all phases of testing. The controller has been designed as an integral subsystem of a system that includes not only the controller and the controlled EEPROM aboard a spacecraft but also computers in a ground control station, relatively simple onboard support circuitry, and an onboard communication subsystem that utilizes the MIL-STD-1553B protocol. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD- 1553B is commonly used in defense and space applications.) The intent was to both maximize reliability while minimizing the size and complexity of onboard circuitry. In operation, control of the EEPROM is effected via the ground computers, the MIL-STD-1553B communication subsystem, and the onboard support circuitry, all of which, in combination, provide the multiple layers of protection against inadvertent writes. There is no controller software, unlike in many prior EEPROM controllers; software can be a major contributor to unreliability, particularly in fault

  4. Inward flux of lactate⁻ through monocarboxylate transporters contributes to regulatory volume increase in mouse muscle fibres.

    PubMed

    Lindinger, Michael I; Leung, Matthew J; Hawke, Thomas J

    2013-01-01

    Mouse and rat skeletal muscles are capable of a regulatory volume increase (RVI) after they shrink (volume loss resultant from exposure to solutions of increased osmolarity) and that this RVI occurs mainly by a Na-K-Cl-Cotransporter (NKCC)-dependent mechanism. With high-intensity exercise, increased extracellular osmolarity is accompanied by large increases in extracellular [lactate⁻]. We hypothesized that large increases in [lactate⁻] and osmolarity augment the NKCC-dependent RVI response observed with a NaCl (or sucrose)-induced increase in osmolarity alone; a response that is dependent on lactate⁻ influx through monocarboxylate transporters (MCTs). Single mouse muscle fibres were isolated and visualized under light microscopy under varying osmolar conditions. When solution osmolarity was increased by adding NaLac by 30 or 60 mM, fibres lost significantly less volume and regained volume sooner compared to when NaCl was used. Phloretin (MCT1 inhibitor) accentuated the volume loss compared to both NaLac controls, supporting a role for MCT1 in the RVI response in the presence of elevated [lactate⁻]. Inhibition of MCT4 (with pCMBS) resulted in a volume loss, intermediate to that seen with phloretin and NaLac controls. Bumetanide (NKCC inhibitor), in combination with pCMBS, reduced the magnitude of volume loss, but volume recovery was complete. While combined phloretin-bumetanide also reduced the magnitude of the volume loss, it also largely abolished the cell volume recovery. In conclusion, RVI in skeletal muscle exposed to raised tonicity and [lactate⁻] is facilitated by inward flux of solute by NKCC- and MCT1-dependent mechanisms. This work demonstrates evidence of a RVI response in skeletal muscle that is facilitated by inward flux of solute by MCT-dependent mechanisms. These findings further expand our understanding of the capacities for skeletal muscle to volume regulate, particularly in instances of raised tonicity and lactate⁻ concentrations, as

  5. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

    1959-11-01

    A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

  6. Computationally efficient control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne (Inventor)

    2001-01-01

    A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

  7. Asthma - control drugs

    MedlinePlus

    ... About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Asthma - control drugs URL of this page: //medlineplus.gov/ency/patientinstructions/000005.htm Asthma - control ...

  8. Demand-controlled lighting

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1977-01-01

    Automatic lighting is controlled by photocell that measures intensity of available light. Photocell drives motor which operates mercury switches controlling indoor illumination sources. Device effects increase in indoor illumination intensity when illumination input to cell is insufficient. Reverse is true if input is too great.

  9. Fiber optics for controls

    NASA Technical Reports Server (NTRS)

    Seng, Gary T.

    1987-01-01

    The challenge of those involved in control-system hardware development is to accommodate an ever-increasing complexity in aircraft control, while limiting the size and weight of the components and improving system reliability. A technology that displays promise towards this end is the area of fiber optics for controls. The primary advantages of employing optical fibers, passive optical sensors, and optically controlled actuators are weight and volume reduction, immunity from electromagnetic effects, superior bandwidth capabilities, and freedom from short circuits and sparking contacts. Since 1975, NASA Lewis has performed in-house, contract, and grant research in fiber optic sensors, high-temperature electro-optic switches, and fly-by-light control-system architecture. Passive optical sensor development is an essential yet challenging area of work and has therefore received much attention during this period. A major effort to develop fly-by-light control-system technology, known as the Fiber-Optic Control System Integration (FOCSI) program, was initiated in 1985 as a cooperative effort between NASA and DOD. Phase 1 of FOCSI, completed in 1986, was aimed at the design of a fiber-optic integrated propulsion/flight control system. Phase 2, yet to be initiated, will provide subcomponent and system development, and a system engine test. In addition to a summary of the benefits of fiber optics, the FOCSI program, sensor advances, and future directions in the NASA Lewis program will be discussed.

  10. Advanced Formation Flight Control.

    DTIC Science & Technology

    1994-12-01

    stabilizes the time dependent linearized plant (7.9) than it is to synthesize a control law which stabilizes the LTI plant (7.5). However, if a stabilizing ... control law is available, Lyapunov’s stabilizability result can also be applied to non LTI scenarios which arise from the application of linearization to

  11. Control of Nonlinear Systems.

    DTIC Science & Technology

    1980-02-26

    above papers shows how the "finite horizon time" feedback stabilization technique discussed in Section Ill-A can be extended to derive stabilizing ... control laws for the linear differential system with delayed controls: x = Ax(t) - 0 u(t) + B 1u(t - h). The second of the above papers shows how the

  12. 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.

  13. Duct Flow Control System.

    DTIC Science & Technology

    is ejected under pressure tangentially of local duct surfaces through Coanda affected slots at the trailing edge of the duct from which only the...channel passages in order to modify the flow stream through the duct so as to perform certain functions such as thrust control and steerage control effects enhancing vehicle maneuverability.

  14. Police Robbery Control Manual.

    ERIC Educational Resources Information Center

    Ward, Richard H.; And Others

    The manual was designed as a practical guide for police department personnel in developing robbery control programs. An introductory chapter defines types of robberies and suggests administrative and operational uses of the manual. Research and control strategies are reported according to five robbery types: street (visible and non-visible),…

  15. Birth Control Ring

    MedlinePlus

    ... It? The birth control ring is a soft, flexible, doughnut-shaped ring about 2 inches (5 centimeters) in diameter. It is inserted into the vagina, where it slowly releases hormones — the chemicals the body makes to control organ function — through the vaginal wall into the ...

  16. Avian influenza control strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control strategies for avian influenza in poultry vary depending on whether the goal is prevention, management, or eradication. Components used in control programs include: 1) education which includes communication, public awareness, and behavioral change, 2) changes to production and marketing sys...

  17. Command and Control.

    ERIC Educational Resources Information Center

    Thwaites, Donald

    1992-01-01

    Provides background information as an introduction to three articles on command and control simulations that involve police and fire departments. Elements of command and control situations are discussed, including leadership, management of people and resources, communication, and coordination; the effectiveness of simulations is considered; and…

  18. Liquid Level Control System.

    DTIC Science & Technology

    A system for controlling liquid flow from an inlet into a tank comprising a normally closed poppet valve controlled by dual pressure chambers each...containing a diaphragm movable by the pressure of the liquid in the inlet to cause the valve to close. Pressure against the diaphragms is relieved by

  19. Control without Wires.

    ERIC Educational Resources Information Center

    Hobart, Jordan

    2002-01-01

    Describes how modern lighting systems, such as wireless lighting, which come complete with user-friendly controls and audio/video interfaces, enhance the educational process and cut costs. Discusses evaluating a building's lighting situation, lighting controls, and such systems' flexibility for future needs. (EV)

  20. Rethinking Coercive Control.

    PubMed

    Stark, Evan

    2009-12-01

    The critical appraisals of Coercive Control focus largely on what my analysis implies for intervention, a matter to which the book devotes only limited space. In this reply, I reiterate core concepts in the book and acknowledge that much more work is needed to translate the realities of coercive control into practical legal and advocacy strategies. I review how coercive control differs from partner assaults and so why it merits a distinct response; the extent to which coercive control targets gender identity; the wisdom of complementing the focus on violence with an emphasis on male domination, sexual inequality and personal liberty; what this implies for shelters and the law; why sexual inequality differentiates coercive control from female partner abuse of men; how sexual equality can be both cause and antidote for coercive control; why I think an affirmative concept of freedom is essential to grasp the human rights violations inflicted by coercive control; and what it means to "story" coercive control by integrating women into the larger liberty narrative on which our national identity rests.

  1. Readings in program control

    NASA Technical Reports Server (NTRS)

    Hoban, Francis T. (Editor); Lawbaugh, William M. (Editor); Hoffman, Edward J. (Editor)

    1994-01-01

    Under the heading of Program Control, a number of related topics are discussed: cost estimating methods; planning and scheduling; cost overruns in the defense industry; the history of estimating; the advantages of cost plus award fee contracts; and how program control techniques led to the success of a NASA development project.

  2. QUALITY CONTROLS FOR PCR

    EPA Science Inventory

    The purpose of this presentation is to present an overview of the quality control (QC) sections of a draft EPA document entitled, "Quality Assurance/Quality Control Guidance for Laboratories Performing PCR Analyses on Environmental Samples." This document has been prepared by th...

  3. Programmable Logic Controllers.

    ERIC Educational Resources Information Center

    Insolia, Gerard; Anderson, Kathleen

    This document contains a 40-hour course in programmable logic controllers (PLC), developed for a business-industry technology resource center for firms in eastern Pennsylvania by Northampton Community College. The 10 units of the course cover the following: (1) introduction to programmable logic controllers; (2) DOS primer; (3) prerequisite…

  4. What Is Numerical Control?

    ERIC Educational Resources Information Center

    Goold, Vernell C.

    1977-01-01

    Numerical control (a technique involving coded, numerical instructions for the automatic control and performance of a machine tool) does not replace fundamental machine tool training. It should be added to the training program to give the student an additional tool to accomplish production rates and accuracy that were not possible before. (HD)

  5. Counseling for Pain Control

    ERIC Educational Resources Information Center

    Espin, Olivia M.; Ganikos, Mary L.

    1975-01-01

    New techniques are being developed that enhance the effectiveness of psychological forces in controlling bodily reactions. All of them are powerful tools for the psychological control of pain. This article reviews such techniques and addresses itself to the contributions that counselors can make to alleviate physical pain. (Author)

  6. Contamination Control Techniques

    SciTech Connect

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  7. Multipath star switch controller

    NASA Technical Reports Server (NTRS)

    Anderson, T. O.

    1980-01-01

    Device concept permits parallel computers to scan several commonnetwork-connected data stations at maximum rate. Sequencers leap-frog to bypass ports already being serviced by another computer. Two-path system for 16-port star switch controller is cost effective if added bandwidth or increased reliability is desired. Triple-path system would be cost effective for 32-port controller.

  8. Encyclopedia of Birth Control.

    ERIC Educational Resources Information Center

    Rengel, Marian

    This encyclopedia brings together in more than 200 entries, arranged in A-to-Z format, a portrait of the complex modern issue that birth control has become with advances in medicine and biochemistry during the 20th century. It is aimed at both the student and the consumer of birth control. Entries cover the following topics: birth control…

  9. Control-structure interaction

    NASA Technical Reports Server (NTRS)

    Cheng, Joseph K.; Ianculescu, George D.; Kenney, Charles S.; Laub, Alan J.; Ly, Jason H. Q.; Papadopoulos, Philip M.

    1992-01-01

    The feasibility of using conventional proportional-integral-derivative (PID) control and an alternative optimal control to perform the pointing and tracking functions of the Space Station solar dynamic power module is investigated. A very large state model of 6 rigid body modes and 272 flexible modes is used in conjunction with classical linear-quadratic-Gaussian (LQG) optimal control to produce a full-order controller that satisfies the requirements. The results are compared with a classically designed PID controller that was implemented for a much smaller (6 rigid body, 40 flexible modes) model. The conventional control design approach is shown to be very much influenced by the order reduction of the plant model, i.e., the number of retained elastic modes from the full-order model, suggesting that for a complex, large space structure, such as the Space Station Freedom solar dynamic module, application of conventional control system design methods may not be adequate. The use of LQG control is recommended, and method for solving the large matrix. Riccati equation that arises from the optimal formulation is provided.

  10. Plating Tank Control Software

    SciTech Connect

    Krafcik, John

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  11. DIESEL NOX CONTROL APPLICATION

    EPA Science Inventory

    The paper gives results of a project to design, develop, and demonstrate a diesel engine nitrogen oxide (NOx) and particulate matter (PM) control package that will meet the U.S. Navy's emission control requirements. (NOTE: In 1994, EPA issued a Notice for Proposed Rule Making (NP...

  12. Public Health Pest Control.

    ERIC Educational Resources Information Center

    Arizona Univ., Tucson. Cooperative Extension Service.

    This manual supplies information helpful to individuals wishing to become certified in public health pest control. It is designed as a technical reference for vector control workers and as preparatory material for structural applicators of restricted use pesticides to meet the General Standards of Competency required of commercial applicators. The…

  13. Hair follicle growth controls.

    PubMed

    Stenn, K S; Combates, N J; Eilertsen, K J; Gordon, J S; Pardinas, J R; Parimoo, S; Prouty, S M

    1996-10-01

    Research in hair biology has embarked in the pursuit for molecules that control hair growth. Many molecules already have been associated with the controls of hair patterning, hair maturation, and hair cycling and differentiation. Knowing how these molecules work gives us the tools for understanding and treating patients with hair disorders.

  14. Nonlinear and adaptive control

    NASA Technical Reports Server (NTRS)

    Athans, Michael

    1989-01-01

    The primary thrust of the research was to conduct fundamental research in the theories and methodologies for designing complex high-performance multivariable feedback control systems; and to conduct feasibiltiy studies in application areas of interest to NASA sponsors that point out advantages and shortcomings of available control system design methodologies.

  15. Who Controls the Video?

    ERIC Educational Resources Information Center

    Hanna, Jack C.

    Television plays a monumentally large role in U.S. society; no one is immune from its effects. The government does not control television, but it is not far from the truth to say that television controls the political life of this country. This paper analyzes the democratic objectives and effects of television in the United States. A brief history…

  16. Resisting Mind Control.

    ERIC Educational Resources Information Center

    Anderson, Susan M.; Zimbardo, Philip G.

    1980-01-01

    Provides conceptual analyses of mind control techniques along with practical advice on how to resist these techniques. The authors stress that effective mind control stems more from everyday social relations than from exotic technological gimmicks. Suggestions are given for resisting persuasion, resisting systems, and challenging the system.…

  17. NEUTRONIC REACTOR CONTROL

    DOEpatents

    Untermyer, S.; Hutter, E.

    1959-08-01

    This patent relates to "shadow" control of a nuclear reactor. The control means comprises a plurality ot elongated rods disposed adjacent and parallel to each other, The morphology and effects of gases generated within sections of neutron absorbing materials and equal length sections of neutron permeable materials together with means for longitudinally pcsitioning the rcds relative to each other.

  18. Controlled Stochastic Dynamical Systems

    DTIC Science & Technology

    2007-04-18

    the existence of value functions of two-player zero-sum stochastic differential games Indiana Univ. Math. Journal, 38 (1989), pp 293-314. [6] George ...control problems, Adv. Appl. Prob., 15, (1983) pp 225-254. [10] Karatzas, I. Ocone, D., Wang, H. and Zervos , M., Finite fuel singular control with

  19. Stepping motor controller

    DOEpatents

    Bourret, Steven C.; Swansen, James E.

    1984-01-01

    A stepping motor is microprocessingly controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  20. Stepping motor controller

    DOEpatents

    Bourret, S.C.; Swansen, J.E.

    1982-07-02

    A stepping motor is microprocessor controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  1. Automotive Pollution Control.

    ERIC Educational Resources Information Center

    Raudenbush, David B.

    Intended for a 1- or 2-month curriculum in auto mechanics, this student manual on automotive pollution control was developed by a subject matter specialist at an area vocational school and tested in a vocational auto shop. Intended either for use in an integrated curriculum or for use in teaching pollution control as a separate course, these 12…

  2. Guidance and Control Software,

    DTIC Science & Technology

    1980-05-01

    FACILITIES Integration Facilities exist for each project and consist of laboratory hot mockups of the actual military computers with realistic...PCIN Al. WEP I AND CONTROL AND CONTRI IF S TO R ESI I I I AIR-SURFACE ASGW WEAPONS I CONTROL L - - L - - - - - - - J L J FIG. 2a 3. HARDWARE

  3. Digital flight control systems

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1977-01-01

    The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

  4. Estimation in satellite control.

    NASA Technical Reports Server (NTRS)

    Debra, D. B.

    1971-01-01

    The use of estimators or observers is discussed as applied to satellite attitude control and the control of drag-free satellites. The practical problems of implementation are discussed, and the relative advantages of full and reduced state estimators are compared, particularly in terms of their effectiveness and bandwidth as filters. Three applications are used to illustrate the principles. They are: (1) a reaction wheel control system, (2) a spinning attitude control system, and (3) a drag-free satellite translational control system. Fixed estimator gains are shown to be adequate for these (and many other) applications. Our experience in the hardware realization of estimators has led to categorize the error sources in terms of those that improve with increased estimator gains and those that get worse with increased estimator gains.

  5. Autorotation flight control system

    NASA Technical Reports Server (NTRS)

    Bachelder, Edward N. (Inventor); Lee, Dong-Chan (Inventor); Aponso, Bimal L. (Inventor)

    2011-01-01

    The present invention provides computer implemented methodology that permits the safe landing and recovery of rotorcraft following engine failure. With this invention successful autorotations may be performed from well within the unsafe operating area of the height-velocity profile of a helicopter by employing the fast and robust real-time trajectory optimization algorithm that commands control motion through an intuitive pilot display, or directly in the case of autonomous rotorcraft. The algorithm generates optimal trajectories and control commands via the direct-collocation optimization method, solved using a nonlinear programming problem solver. The control inputs computed are collective pitch and aircraft pitch, which are easily tracked and manipulated by the pilot or converted to control actuator commands for automated operation during autorotation in the case of an autonomous rotorcraft. The formulation of the optimal control problem has been carefully tailored so the solutions resemble those of an expert pilot, accounting for the performance limitations of the rotorcraft and safety concerns.

  6. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, Robert R. (Inventor)

    1987-01-01

    A remotely controllable mixing system (210) in which a plurality of mixing assemblies (10a-10e) are arranged in an annular configuration, and wherein each assembly (10) employs a central chamber (16) and two outer, upper and lower, chambers (12, 14). Valves (18, 20) are positioned between chambers, and these valves (18, 20) for a given mixing assembly (10) are operated by upper and lower control rotors (29), which in turn are driven by upper and lower drive rotors (270, 270b). Additionally, a hoop (278) is compressed around upper control rotors (29) and a hoop (278b) is compressed around lower control rotors (29) to thus insure constant frictional engagement between all control rotors (29) and drive rotors (270, 270b). The drive rollers (270, 270b) are driven by a motor (213).

  7. Intelligent Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R (Inventor)

    2015-01-01

    The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

  8. CAVITY CONTROL ALGORITHM

    SciTech Connect

    Tomasz Plawski, J. Hovater

    2010-09-01

    A digital low level radio frequency (RF) system typically incorporates either a heterodyne or direct sampling technique, followed by fast ADCs, then an FPGA, and finally a transmitting DAC. This universal platform opens up the possibilities for a variety of control algorithm implementations. The foremost concern for an RF control system is cavity field stability, and to meet the required quality of regulation, the chosen control system needs to have sufficient feedback gain. In this paper we will investigate the effectiveness of the regulation for three basic control system algorithms: I&Q (In-phase and Quadrature), Amplitude & Phase and digital SEL (Self Exciting Loop) along with the example of the Jefferson Lab 12 GeV cavity field control system.

  9. Discrete Variational Optimal Control

    NASA Astrophysics Data System (ADS)

    Jiménez, Fernando; Kobilarov, Marin; Martín de Diego, David

    2013-06-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, and underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical examples and a practical one, the control of an underwater vehicle, illustrate the application of the proposed approach.

  10. Shock absorber control system

    SciTech Connect

    Nakano, Y.; Ohira, M.; Ushida, M.; Miyagawa, T.; Shimodaira, T.

    1987-01-13

    A shock absorber control system is described for controlling a dampening force of a shock absorber of a vehicle comprising: setting means for setting a desired dampening force changeable within a predetermined range; drive means for driving the shock absorber to change the dampening force of the shock absorber linearly; control means for controlling the drive means in accordance with the desired dampening force when the setting of the desired dampening force has been changed; detecting means for detecting an actual dampening force of the shock absorber; and correcting means for correcting the dampening force of the shock absorber by controlling the drive means in accordance with a difference between the desired dampening force and the detected actual dampening force.

  11. Cyclic control stick

    DOEpatents

    Whitaker, Charles N.; Zimmermann, Richard E.

    1989-01-01

    A cyclic control stick of the type used in helicopters for reducing the safety hazards associated with such a mechanism in the event of a crewman being thrown violently into contact with the cyclic control stick resulting from a crash or the like. The cyclic control stick is configured to break away upon the exertion of an impact force which exceeds a predetermined value and/or is exerted for more than a momentary time duration. The cyclic control stick is also configured to be adjustable so as to locate the grip thereof as far away from the crewman as possible for safety reasons without comprising the comfort of the crewman or the use of the control stick, and a crushable pad is provided on the top of the grip for impact energy absorbing purposes.

  12. 3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES INCREASINGLY AUTOMATED, EAGLE ROCK WILL BECOME MORE AND MORE THE CENTRAL CONTROL SYSTEM OF THE METROPOLITAN WATER DISTRICT. - Eagle Rock Operations Control Center, Pasadena, Los Angeles County, CA

  13. Neural Flight Control System

    NASA Technical Reports Server (NTRS)

    Gundy-Burlet, Karen

    2003-01-01

    The Neural Flight Control System (NFCS) was developed to address the need for control systems that can be produced and tested at lower cost, easily adapted to prototype vehicles and for flight systems that can accommodate damaged control surfaces or changes to aircraft stability and control characteristics resulting from failures or accidents. NFCS utilizes on a neural network-based flight control algorithm which automatically compensates for a broad spectrum of unanticipated damage or failures of an aircraft in flight. Pilot stick and rudder pedal inputs are fed into a reference model which produces pitch, roll and yaw rate commands. The reference model frequencies and gains can be set to provide handling quality characteristics suitable for the aircraft of interest. The rate commands are used in conjunction with estimates of the aircraft s stability and control (S&C) derivatives by a simplified Dynamic Inverse controller to produce virtual elevator, aileron and rudder commands. These virtual surface deflection commands are optimally distributed across the aircraft s available control surfaces using linear programming theory. Sensor data is compared with the reference model rate commands to produce an error signal. A Proportional/Integral (PI) error controller "winds up" on the error signal and adds an augmented command to the reference model output with the effect of zeroing the error signal. In order to provide more consistent handling qualities for the pilot, neural networks learn the behavior of the error controller and add in the augmented command before the integrator winds up. In the case of damage sufficient to affect the handling qualities of the aircraft, an Adaptive Critic is utilized to reduce the reference model frequencies and gains to stay within a flyable envelope of the aircraft.

  14. Extended cooperative control synthesis

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Schmidt, David K.

    1994-01-01

    This paper reports on research for extending the Cooperative Control Synthesis methodology to include a more accurate modeling of the pilot's controller dynamics. Cooperative Control Synthesis (CCS) is a methodology that addresses the problem of how to design control laws for piloted, high-order, multivariate systems and/or non-conventional dynamic configurations in the absence of flying qualities specifications. This is accomplished by emphasizing the parallel structure inherent in any pilot-controlled, augmented vehicle. The original CCS methodology is extended to include the Modified Optimal Control Model (MOCM), which is based upon the optimal control model of the human operator developed by Kleinman, Baron, and Levison in 1970. This model provides a modeling of the pilot's compensation dynamics that is more accurate than the simplified pilot dynamic representation currently in the CCS methodology. Inclusion of the MOCM into the CCS also enables the modeling of pilot-observation perception thresholds and pilot-observation attention allocation affects. This Extended Cooperative Control Synthesis (ECCS) allows for the direct calculation of pilot and system open- and closed-loop transfer functions in pole/zero form and is readily implemented in current software capable of analysis and design for dynamic systems. Example results based upon synthesizing an augmentation control law for an acceleration command system in a compensatory tracking task using the ECCS are compared with a similar synthesis performed by using the original CCS methodology. The ECCS is shown to provide augmentation control laws that yield more favorable, predicted closed-loop flying qualities and tracking performance than those synthesized using the original CCS methodology.

  15. On identified predictive control

    NASA Technical Reports Server (NTRS)

    Bialasiewicz, Jan T.

    1993-01-01

    Self-tuning control algorithms are potential successors to manually tuned PID controllers traditionally used in process control applications. A very attractive design method for self-tuning controllers, which has been developed over recent years, is the long-range predictive control (LRPC). The success of LRPC is due to its effectiveness with plants of unknown order and dead-time which may be simultaneously nonminimum phase and unstable or have multiple lightly damped poles (as in the case of flexible structures or flexible robot arms). LRPC is a receding horizon strategy and can be, in general terms, summarized as follows. Using assumed long-range (or multi-step) cost function the optimal control law is found in terms of unknown parameters of the predictor model of the process, current input-output sequence, and future reference signal sequence. The common approach is to assume that the input-output process model is known or separately identified and then to find the parameters of the predictor model. Once these are known, the optimal control law determines control signal at the current time t which is applied at the process input and the whole procedure is repeated at the next time instant. Most of the recent research in this field is apparently centered around the LRPC formulation developed by Clarke et al., known as generalized predictive control (GPC). GPC uses ARIMAX/CARIMA model of the process in its input-output formulation. In this paper, the GPC formulation is used but the process predictor model is derived from the state space formulation of the ARIMAX model and is directly identified over the receding horizon, i.e., using current input-output sequence. The underlying technique in the design of identified predictive control (IPC) algorithm is the identification algorithm of observer/Kalman filter Markov parameters developed by Juang et al. at NASA Langley Research Center and successfully applied to identification of flexible structures.

  16. Velocity vector control system augmented with direct lift control

    NASA Technical Reports Server (NTRS)

    Tisdale, H. F., Sr.; Kelly, W. W. (Inventor)

    1981-01-01

    A pilot-controlled stability control system that employs direct lift control (spoiler control) with elevator control to control the flight path angle of an aircraft is described. A computer on the aircraft generates an elevator control signal and a spoiler control signal, using a pilot-controlled pitch control signal and pitch rate, vertical velocity, roll angle, groundspeed, engine pressure ratio and vertical acceleration signals which are generated on the aircraft. The direct lift control by the aircraft spoilers improves the response of the aircraft flight path angle and provides short term flight path stabilization against environmental disturbances.

  17. Load Control System Reliability

    SciTech Connect

    Trudnowski, Daniel

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  18. Gemini Scout Control Software

    SciTech Connect

    Clinton Hobart, Justin Garretson

    2010-11-23

    The Gemini Scout Control Software consists of two Windows applications that allow the Gemini Scout vehicle to be controlled by an operator. The Embedded application runs on the vehicle's Gemini Scout Control Software onboard computer and controls the vehicle's various motors and sensors. This application reports the vehicle's status and receives vehicle commands overthe local-area-network. The Embedded applicationalso allows the user to control the vehicle using a USB game-pad connected directly to the vehicle. The Operator Control Unit (OCU) application runs on an external PC and communicates with the vehicle via an Ethernet connection. The OCU application sends commands to and receives data from the Embedded application running on the vehicle. The OCU application also communicates directly with the digital video encoders and radios in order to display video from the vehicle's cameras and the status of the radio link. The OCU application has a graphical user interface (GUI) that displays the vehicle's status and allows the user to change various vehicle settings. Finally, the OCU application receives input from a USB game-pad connected to the PC in order to control the vehicle's functions.

  19. Control of vortex dynamics

    NASA Astrophysics Data System (ADS)

    Chang, Hsiao-Lung

    Discrete vortex methods are used to provide computationally efficient simulations of vortex dynamics in fluid flows. An adaptive LQG controller is applied to reduce the oscillations in the wake caused by the vortex dynamics. The controller design is based on a discrete-time input/output model rather than the nonlinear differential equations of the discrete vortex model. The control philosophy is to identify time-varying parameters in the input/output model adaptively and use the identified parameters to update the control law. For numerically stable identification, an adaptive algorithm based on inverse QR decomposition is introduced. The derivation shows that this algorithm is a square-root implementation of recursive least squares estimation. For a preliminary test of the control strategy, the adaptive LQG controller is applied to a vortex street model simulated by discrete vortices. The identification shows that the stability of the identified zeros depends on whether the sensor is upstream or downstream of the actuator. Flow past a flat plate is another important application of the discrete vortex method. A control problem is studied and simulated in which suction at the back face of the plate is used to trap vortices behind the plate. Qualitatively, the results obtained with the discrete-vortex method used here agree with earlier results for a substantially different vortex method involving a small number of differential equations.

  20. Fiber optics for controls

    NASA Technical Reports Server (NTRS)

    Seng, Gary T.

    1990-01-01

    The design, development, and testing of a fiber optic integrated propulsion/flight control system for an advanced supersonic dash aircraft (flies at supersonic speeds for short periods of time) is the goal of the joint NASA/DOD Fiber Optic Control System Integration (FOCSI) program. Phase 1 provided a comparison of electronic and optical control systems, identified the status of current optical sensor technology, defined the aircraft sensor/actuator environment, proposed architectures for fully optical control systems, and provided schedules for development. Overall, it was determined that there are sufficient continued efforts to develop such a system. It was also determined that it is feasible to build a fiber optic control system for the development of a data base for this technology, but that further work is necessary in sensors, actuators, and components to develop an optimum design, fully fiber optic integrated control system compatible with advanced aircraft environments. Phase 2 is to design, construct, and ground test a fly by light control system. Its first task is to provide a detailed design of the electro-optic architecture.

  1. Controllability of flow turbulence.

    PubMed

    Guan, Shuguang; Wei, G W; Lai, C-H

    2004-06-01

    In this paper, we study the controllability of real-world flow turbulence governed by the two-dimensional Navier-Stokes equations, using strategies developed in chaos control. A case of control/synchronization of turbulent dynamics is observed when only one component of the velocity field vector is unidirectionally coupled to a target state, while the other component is uncoupled. Unlike previous results, it is shown that the dynamics of the whole velocity field cannot be completely controlled/synchronized to the target, even in the limit of long time and strong coupling strength. It is further revealed that the controlled component of the velocity field can be fully controlled/synchronized to the target, but the other component, which is not directly coupled to the target, can only be partially controlled/synchronized to the target. By extending an auxiliary method to distributed dynamic systems, the partial synchronization of two turbulent orbits in the present study can be categorized in the domain of generalized synchronization of spatiotemporal dynamics.

  2. IGISOL control system modernization

    NASA Astrophysics Data System (ADS)

    Koponen, J.; Hakala, J.

    2016-06-01

    Since 2010, the IGISOL research facility at the Accelerator laboratory of the University of Jyväskylä has gone through major changes. Comparing the new IGISOL4 facility to the former IGISOL3 setup, the size of the facility has more than doubled, the length of the ion transport line has grown to about 50 m with several measurement setups and extension capabilities, and the accelerated ions can be fed to the facility from two different cyclotrons. The facility has evolved to a system comprising hundreds of manual, pneumatic and electronic devices. These changes have prompted the need to modernize also the facility control system taking care of monitoring and transporting the ion beams. In addition, the control system is also used for some scientific data acquisition tasks. Basic guidelines for the IGISOL control system update have been remote control, safety, usability, reliability and maintainability. Legacy components have had a major significance in the control system hardware and for the renewed control system software the Experimental Physics and Industrial Control System (EPICS) has been chosen as the architectural backbone.

  3. Deadbeat Predictive Controllers

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan; Phan, Minh

    1997-01-01

    Several new computational algorithms are presented to compute the deadbeat predictive control law. The first algorithm makes use of a multi-step-ahead output prediction to compute the control law without explicitly calculating the controllability matrix. The system identification must be performed first and then the predictive control law is designed. The second algorithm uses the input and output data directly to compute the feedback law. It combines the system identification and the predictive control law into one formulation. The third algorithm uses an observable-canonical form realization to design the predictive controller. The relationship between all three algorithms is established through the use of the state-space representation. All algorithms are applicable to multi-input, multi-output systems with disturbance inputs. In addition to the feedback terms, feed forward terms may also be added for disturbance inputs if they are measurable. Although the feedforward terms do not influence the stability of the closed-loop feedback law, they enhance the performance of the controlled system.

  4. Fault tolerant control laws

    NASA Technical Reports Server (NTRS)

    Ly, U. L.; Ho, J. K.

    1986-01-01

    A systematic procedure for the synthesis of fault tolerant control laws to actuator failure has been presented. Two design methods were used to synthesize fault tolerant controllers: the conventional LQ design method and a direct feedback controller design method SANDY. The latter method is used primarily to streamline the full-state Q feedback design into a practical implementable output feedback controller structure. To achieve robustness to control actuator failure, the redundant surfaces are properly balanced according to their control effectiveness. A simple gain schedule based on the landing gear up/down logic involving only three gains was developed to handle three design flight conditions: Mach .25 and Mach .60 at 5000 ft and Mach .90 at 20,000 ft. The fault tolerant control law developed in this study provides good stability augmentation and performance for the relaxed static stability aircraft. The augmented aircraft responses are found to be invariant to the presence of a failure. Furthermore, single-loop stability margins of +6 dB in gain and +30 deg in phase were achieved along with -40 dB/decade rolloff at high frequency.

  5. Model based manipulator control

    NASA Technical Reports Server (NTRS)

    Petrosky, Lyman J.; Oppenheim, Irving J.

    1989-01-01

    The feasibility of using model based control (MBC) for robotic manipulators was investigated. A double inverted pendulum system was constructed as the experimental system for a general study of dynamically stable manipulation. The original interest in dynamically stable systems was driven by the objective of high vertical reach (balancing), and the planning of inertially favorable trajectories for force and payload demands. The model-based control approach is described and the results of experimental tests are summarized. Results directly demonstrate that MBC can provide stable control at all speeds of operation and support operations requiring dynamic stability such as balancing. The application of MBC to systems with flexible links is also discussed.

  6. Moving Object Control System

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

    2001-01-01

    A method is provided for controlling two objects relatively moveable with respect to each other. A plurality of receivers are provided for detecting a distinctive microwave signal from each of the objects and measuring the phase thereof with respect to a reference signal. The measured phase signal is used to determine a distance between each of the objects and each of the plurality of receivers. Control signals produced in response to the relative distances are used to control the position of the two objects.

  7. Shaft speed control

    NASA Technical Reports Server (NTRS)

    Ford, A. G.

    1979-01-01

    Simple mechanism controls rotation of heavy-duty shaft by mechanical comparison with rotation of small, precise, stepper motor. Mechanism can be used to limit winding and unwinding speeds of large spools and reels and to control speed of other rotating shafts. Setup incorporates reference shaft geared down from stepper motor and feedback shaft geared up from shaft to be controlled. Feedback and reference shafts are coupled with brake assembly inside stationary cylinder. When work shaft speeds up, brakes are activated automatically to slow it down.

  8. Flash protection controller

    DOEpatents

    Galbraith, Lee K.

    1981-01-01

    A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.

  9. Temperature-Controlling Circuit

    NASA Technical Reports Server (NTRS)

    Temple, Gerald

    1987-01-01

    Simple circuit switches current to electrical heater on and off to maintain temperature of room at 25 plus or minus 0.5 degree C. Lightweight, compact, reliable, insensitive to electrical noise, and uses single 5-Vdc power supply. Handles ac loads of 10 A. Designed to operate outside temperature controlled environment over range of -55 to +85 degree C. Thermistor provides input signal for simple temperature controller. Output of controller applied to solid-state relay, which in turn switches current to resistance heater.

  10. Analyzing Feedback Control Systems

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.; Downing, John P.

    1987-01-01

    Interactive controls analysis (INCA) program developed to provide user-friendly environment for design and analysis of linear control systems, primarily feedback control. Designed for use with both small- and large-order systems. Using interactive-graphics capability, INCA user quickly plots root locus, frequency response, or time response of either continuous-time system or sampled-data system. Configuration and parameters easily changed, allowing user to design compensation networks and perform sensitivity analyses in very convenient manner. Written in Pascal and FORTRAN.

  11. Surface controlled blade stabilizer

    DOEpatents

    Russell, Larry R.

    1983-01-01

    Drill string stabilizer apparatus, controllable to expand and retract entirely from the surface by control of drill string pressure, wherein increase of drill string pressure from the surface closes a valve to create a piston means which is moved down by drill string pressure to expand the stabilizer blades, said valve being opened and the piston moving upward upon reduction of drill string pressure to retract the stabilizer blades. Upward and downward movements of the piston and an actuator sleeve therebelow are controlled by a barrel cam acting between the housing and the actuator sleeve.

  12. Optical controlled keyboard system

    NASA Astrophysics Data System (ADS)

    Budzyński, Łukasz; Długosz, Dariusz; Niewiarowski, Bartosz; Zajkowski, Maciej

    2011-06-01

    Control systems of our computers are common devices, based on the manipulation of keys or a moving ball. Completely healthy people have no problems with the operation of such devices. Human disability makes everyday activities become a challenge and create trouble. When a man can not move his hands, the work becomes difficult or often impossible. Controlled optical keyboard is a modern device that allows to bypass the limitations of disability limbs. The use of wireless optical transmission allows to control computer using a laser beam, which cooperates with the photodetectors. The article presents the construction and operation of non-contact optical keyboard for people with disabilities.

  13. Advanced Wavefront Control Techniques

    SciTech Connect

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    Programs at LLNL that involve large laser systems--ranging from the National Ignition Facility to new tactical laser weapons--depend on the maintenance of laser beam quality through precise control of the optical wavefront. This can be accomplished using adaptive optics, which compensate for time-varying aberrations that are often caused by heating in a high-power laser system. Over the past two decades, LLNL has developed a broad capability in adaptive optics technology for both laser beam control and high-resolution imaging. This adaptive optics capability has been based on thin deformable glass mirrors with individual ceramic actuators bonded to the back. In the case of high-power lasers, these adaptive optics systems have successfully improved beam quality. However, as we continue to extend our applications requirements, the existing technology base for wavefront control cannot satisfy them. To address this issue, this project studied improved modeling tools to increase our detailed understanding of the performance of these systems, and evaluated novel approaches to low-order wavefront control that offer the possibility of reduced cost and complexity. We also investigated improved beam control technology for high-resolution wavefront control. Many high-power laser systems suffer from high-spatial-frequency aberrations that require control of hundreds or thousands of phase points to provide adequate correction. However, the cost and size of current deformable mirrors can become prohibitive for applications requiring more than a few tens of phase control points. New phase control technologies are becoming available which offer control of many phase points with small low-cost devices. The goal of this project was to expand our wavefront control capabilities with improved modeling tools, new devices that reduce system cost and complexity, and extensions to high spatial and temporal frequencies using new adaptive optics technologies. In FY 99, the second year of

  14. Flash protection controller

    DOEpatents

    Galbraith, L.K.

    1979-12-07

    A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.

  15. Splines and control theory

    NASA Technical Reports Server (NTRS)

    Zhang, Zhimin; Tomlinson, John; Martin, Clyde

    1994-01-01

    In this work, the relationship between splines and the control theory has been analyzed. We show that spline functions can be constructed naturally from the control theory. By establishing a framework based on control theory, we provide a simple and systematic way to construct splines. We have constructed the traditional spline functions including the polynomial splines and the classical exponential spline. We have also discovered some new spline functions such as trigonometric splines and the combination of polynomial, exponential and trigonometric splines. The method proposed in this paper is easy to implement. Some numerical experiments are performed to investigate properties of different spline approximations.

  16. Radiological Control Manual

    SciTech Connect

    Not Available

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records.

  17. Infection prevention and control.

    PubMed

    Pegram, Anne; Bloomfield, Jacqueline

    2015-03-18

    All newly registered graduate nurses are required to have the appropriate knowledge and understanding to perform the skills required for patient care, specifically the competencies identified in the Nursing and Midwifery Council's essential skills clusters. This article focuses on the third essential skills cluster - infection prevention and control. It provides an overview and discussion of the key skills and behaviours that must be demonstrated to meet the standards set by the Nursing and Midwifery Council. In doing so, it considers the key principles of infection prevention and control, including local and national policies, standard infection control precautions, risk assessment, standard isolation measures and asepsis.

  18. Optimized joystick controller.

    PubMed

    Ding, D; Cooper, R A; Spaeth, D

    2004-01-01

    The purpose of the study was to develop an optimized joystick control interface for electric powered wheelchairs and thus provide safe and effective control of electric powered wheelchairs to people with severe physical disabilities. The interface enables clinicians to tune joystick parameters for each individual subject through selecting templates, dead zones, and bias axes. In terms of hand tremor usually associated with people with traumatic brain injury, cerebral palsy, and multiple sclerosis, fuzzy logic rules were applied to suppress erratic hand movements and extract the intended motion from the joystick. Simulation results were presented to show the graphical tuning interface as well as the performance of the fuzzy logic controller.

  19. Cockpit control system

    NASA Technical Reports Server (NTRS)

    Lesnewski, David; Snow, Russ M.; Paufler, Dave; Schnieder, George; Athousake, Roxanne; Combs, Lisa

    1993-01-01

    The purpose of this project is to provide a detail design for the cockpit control system of the Viper PFT. The statement of work for this project requires provisions for control of the ailerons, elevator, rudder, and elevator trim. The system should provide adjustment for pilot stature, rigging, and maintenance. MIL-STD-1472 is used as a model for human factors criterion. The system is designed to the pilot limit loading outlined in FAR part 23.397. The general philosophy behind this design is to provide a simple, reliable control system which will withstand the daily abuse that is experienced in the training environment without excessive cost or weight penalties.

  20. Asthma Triggers: Gain Control

    MedlinePlus

    ... of Page Additional resources An Introduction to Indoor Air Quality: Biological Pollutants Help Your Child Gain Control Over ... exhaust, smoke, road dust and factory emissions. Outdoor air quality is also affected by pollen from plants, crops ...

  1. Digital numerically controlled oscillator

    NASA Technical Reports Server (NTRS)

    Cellier, A.; Huey, D. C.; Ma, L. N. (Inventor)

    1980-01-01

    The frequency and phase of an output signal from an oscillator circuit are controlled with accuracy by a digital input word. Positive and negative alterations in output frequency are both provided for by translating all values of input words so that they are positive. The oscillator reference frequency is corrected only in one direction, by adding phase to the output frequency of the oscillator. The input control word is translated to a single algebraic sign and the digital 1 is added thereto. The translated input control word is then accumulated. A reference clock signal having a frequency at an integer multiple of the desired frequency of the output signal is generated. The accumulated control word is then compared with a threshold level. The output signal is adjusted in a single direction by dividing the frequency of the reference clock signal by a first integer or by an integer different from the first integer.

  2. Engineering of metabolic control

    DOEpatents

    Liao, James C.

    2004-03-16

    The invention features a method of producing heterologous molecules in cells under the regulatory control of a metabolite and metabolic flux. The method can enhance the synthesis of heterologous polypeptides and metabolites.

  3. Engineering of metabolic control

    DOEpatents

    Liao, James C.

    2006-10-17

    The invention features a method of producing heterologous molecules in cells under the regulatory control of a metabolite and metabolic flux. The method can enhance the synthesis of heterologous polypeptides and metabolites.

  4. Odor Control Technology

    ERIC Educational Resources Information Center

    Turk, Amos; And Others

    1972-01-01

    Dispersion, chemical oxidation, and masking are reviewed as techniques primarily employed for odor control. Devices and systems, costs, and problems of measurement are considered in light of environmental agencies' efforts to curb smelly emissions. (BL)

  5. Controlling Cholesterol with Statins

    MedlinePlus

    ... For Consumers Home For Consumers Consumer Updates Controlling Cholesterol with Statins Share Tweet Linkedin Pin it More ... not, the following tips can help keep your cholesterol in check: Talk with your healthcare provider about ...

  6. Riot Control Agents

    MedlinePlus

    ... CDC.gov . Specific Hazards Bioterrorism A-Z Anthrax (Bacillus anthracis) Arenaviruses Treatment & Infection Control Specimen Submission & Lab Testing Education & Training Related Bioterrorism Resources Bacillus anthracis (Anthrax) Botulism (Clostridium botulinum toxin) Brucella species ( ...

  7. Monitoring by Control Technique

    EPA Pesticide Factsheets

    Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page links to different control techniques used to reduce pollutant emissions.

  8. CHLORINATED SOLVENT PLUME CONTROL

    EPA Science Inventory

    This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE).

  9. Uncertainty and Cognitive Control

    PubMed Central

    Mushtaq, Faisal; Bland, Amy R.; Schaefer, Alexandre

    2011-01-01

    A growing trend of neuroimaging, behavioral, and computational research has investigated the topic of outcome uncertainty in decision-making. Although evidence to date indicates that humans are very effective in learning to adapt to uncertain situations, the nature of the specific cognitive processes involved in the adaptation to uncertainty are still a matter of debate. In this article, we reviewed evidence suggesting that cognitive control processes are at the heart of uncertainty in decision-making contexts. Available evidence suggests that: (1) There is a strong conceptual overlap between the constructs of uncertainty and cognitive control; (2) There is a remarkable overlap between the neural networks associated with uncertainty and the brain networks subserving cognitive control; (3) The perception and estimation of uncertainty might play a key role in monitoring processes and the evaluation of the “need for control”; (4) Potential interactions between uncertainty and cognitive control might play a significant role in several affective disorders. PMID:22007181

  10. Odor control in lagoons.

    PubMed

    Zhang, X L; Yan, S; Tyagi, R D; Surampalli, R Y

    2013-07-30

    Lagoons are widely used in rural area for wastewater treatment; however, the odor problem has hampered its application. The root of odor emission from lagoons varies from one to another. The key of controlling the odor is to find out the cause and accordingly provide strategies. Various physical, chemical, and biological methods have been reported and applied for odor control. Physical technologies such as masking, capturing and sorption are often employed to mitigate the pressure from compliant while not to cut off the problem. Chemical technologies which act rapidly and efficiently in odor control, utilize chemicals to damage the odorant production root or convert odorant to odorless substances. Biological methods such as aeration, biocover and biofiltration control the odor by enhancing aerobic condition or developing methanogens in lagoon, and biologically decomposing the odorants. Comparing to physical and chemical methods, biological methods are more feasible.

  11. ELECTRONIC PHASE CONTROL CIRCUIT

    DOEpatents

    Salisbury, J.D.; Klein, W.W.; Hansen, C.F.

    1959-04-21

    An electronic circuit is described for controlling the phase of radio frequency energy applied to a multicavity linear accelerator. In one application of the circuit two cavities are excited from a single radio frequency source, with one cavity directly coupled to the source and the other cavity coupled through a delay line of special construction. A phase detector provides a bipolar d-c output signal proportional to the difference in phase between the voltage in the two cavities. This d-c signal controls a bias supply which provides a d-c output for varying the capacitnce of voltage sensitive capacitors in the delay line. The over-all operation of the circuit is completely electronic, overcoming the time response limitations of the electromechanical control systems, and the relative phase relationship of the radio frequency voltages in the two caviiies is continuously controlled to effect particle acceleration.

  12. JPL Contamination Control Engineering

    NASA Technical Reports Server (NTRS)

    Blakkolb, Brian

    2013-01-01

    JPL has extensive expertise fielding contamination sensitive missions-in house and with our NASA/industry/academic partners.t Development and implementation of performance-driven cleanliness requirements for a wide range missions and payloads - UV-Vis-IR: GALEX, Dawn, Juno, WFPC-II, AIRS, TES, et al - Propulsion, thermal control, robotic sample acquisition systems. Contamination control engineering across the mission life cycle: - System and payload requirements derivation, analysis, and contamination control implementation plans - Hardware Design, Risk trades, Requirements V-V - Assembly, Integration & Test planning and implementation - Launch site operations and launch vehicle/payload integration - Flight ops center dot Personnel on staff have expertise with space materials development and flight experiments. JPL has capabilities and expertise to successfully address contamination issues presented by space and habitable environments. JPL has extensive experience fielding and managing contamination sensitive missions. Excellent working relationship with the aerospace contamination control engineering community/.

  13. NEWS: Feeling in control?

    NASA Astrophysics Data System (ADS)

    2000-05-01

    Windmill Graphics simulation software has been developed to help explain control technology to students. The software allows an engineering process such as might be found in the oil or gas industry to be controlled from a PC through simulations of closing drain valves, filling tanks, starting heating operations etc. Other tasks include using level control systems with digital sensors, temperature control with digital and analogue sensors and monitoring systems plus datalogging. The kit was funded by the Scottish Higher Still Development Unit and it has been distributed to all secondary schools, further education colleges and teacher training institutes in Scotland. It will also in turn be distributed to all schools in England, but in the meantime free copies can be downloaded from: www.windmill.co.uk/wmldemo.html

  14. Controlled Cardiac Computed Tomography

    PubMed Central

    Wang, Chenglin; Liu, Ying; Wang, Ge

    2006-01-01

    Cardiac computed tomography (CT) has been a hot topic for years because of the clinical importance of cardiac diseases and the rapid evolution of CT systems. In this paper, we propose a novel strategy for controlled cardiac CT that may effectively reduce image artifacts due to cardiac and respiratory motions. Our approach is radically different from existing ones and is based on controlling the X-ray source rotation velocity and powering status in reference to the cardiac motion. We theoretically show that by such a control-based intervention the data acquisition process can be optimized for cardiac CT in the cases of periodic and quasiperiodic cardiac motions. Specifically, we formulate the corresponding coordination/control schemes for either exact or approximate matches between the ideal and actual source positions, and report representative simulation results that support our analytic findings. PMID:23165017

  15. Active control of convection

    SciTech Connect

    Bau, H.H.

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  16. Vapor Control Layer Recommendations

    SciTech Connect

    2009-09-08

    This information sheet describes the level of vapor control required on the interior side of framed walls with typical fibrous cavity insulation (fibreglass, rockwool, or cellulose, based on DOE climate zone of construction.

  17. Computer controlled antenna system

    NASA Technical Reports Server (NTRS)

    Raumann, N. A.

    1972-01-01

    Digital techniques are discussed for application to the servo and control systems of large antennas. The tracking loop for an antenna at a STADAN tracking site is illustrated. The augmentation mode is also considered.

  18. Advances in infection control

    PubMed Central

    Marra, Alexandre Rodrigues

    2016-01-01

    ABSTRACT Several initiatives took place in recent years in relation to nosocomial infection control in order to increase patient safety. Some of these initiatives will be commented in this brief review. PMID:27074240

  19. Cryogenic Control System

    SciTech Connect

    Goloborod'ko, S.; /Fermilab

    1989-02-27

    The control system (CS) for the cryogenic arrangement of the DO Liquid Argon Calorimeter consists of a Texas instruments 560/565 Programmable Logical Controller (PLC), two remote bases with Remote Base Controllers and a corresponding set of input/output (I/O) modules, and a PC AST Premium 286 (IBM AT Compatible). The PLC scans a set of inputs and provides a set of outputs based on a ladder logic program and PID control loops. The inputs are logic or analog (current, voltage) signals from equipment status switches or transducers. The outputs are logic or analog (current or voltage) signals for switching solenoids and positioning pneumatic actuators. Programming of the PLC is preformed by using the TISOFT2/560/565 package, which is installed in the PC. The PC communicates to the PLC through a serial RS232 port and provides operator interface to the cryogenic process using Xpresslink software.

  20. Birth control pills - combination

    MedlinePlus

    The pill - combination; Oral contraceptives - combination; OCP - combination; Contraception - combination; BCP - combination ... Birth control pills help keep you from getting pregnant. When taken daily, they are one of the most ...

  1. Linear Hereditary Control Systems,

    DTIC Science & Technology

    Relationships between external and internal models for systems with time lags are discussed. The use of various canonical forms for the models in solving optimal control problems is considered. (Author)

  2. Surface Enhanced Quantum Control

    NASA Astrophysics Data System (ADS)

    Rangan, Chitra

    2013-05-01

    Miniaturization of quantum technologies have led to physics that require the marriage of atomic physics and nanomaterials science. Some of the resulting areas of research are hybrid quantum devices, single-molecule spectroscopies, table-top intense field generators, etc. I will present an area of research that I dub ``Surface-enhanced quantum control'' that is an exciting way of controlling light and nanomatter. By combining the electromagnetic enhancement properties of plasmonic nanomaterials with the modification of the atomic properties, we can achieve an unprecedented level of control over quantum dynamics. I will present examples of surface-enhanced state purification, in which quantum states near metal nanostructures can be rapidly purified by the application of a weak near-resonant control field. We gratefully acknowledge support from the NSERC Discovery Grant Program and the NSERC Strategic Network for Bioplasmonic Systems.

  3. Ferroelectric Light Control Device

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Kim, Jae-Woo (Inventor); Elliott, Jr., James R. (Inventor)

    2008-01-01

    A light control device is formed by ferroelectric material and N electrodes positioned adjacent thereto to define an N-sided regular polygonal region or circular region there between where N is a multiple of four.

  4. Cairo: repackaging population control.

    PubMed

    Simons, H

    1995-01-01

    Aid agencies, charities, and other nongovernmental organizations once denounced population control programs as racist interference in the third world. Yet, at the United Nations Conference on Population and Development in Cairo last September, these same organizations endorsed very similar ideas. The U.N. can now claim that even its fiercest critics not only have muted their criticism of population control programs but now positively endorse them. Over the last 30 years, population control has been consciously repackaged by the U.S. establishment. The image of population control has changed from being overtly anti-third world to being about giving the people of the third world--especially women--basic rights in family planning. Wrapped up in the language of women's empowerment and environmentalism, the establishment's old arguments about there being too many nonwhite babies in the world, have, unfortunately, won the day.

  5. Telerobot control system

    NASA Technical Reports Server (NTRS)

    Backes, Paul G. (Inventor); Tso, Kam S. (Inventor)

    1993-01-01

    This invention relates to an operator interface for controlling a telerobot to perform tasks in a poorly modeled environment and/or within unplanned scenarios. The telerobot control system includes a remote robot manipulator linked to an operator interface. The operator interface includes a setup terminal, simulation terminal, and execution terminal for the control of the graphics simulator and local robot actuator as well as the remote robot actuator. These terminals may be combined in a single terminal. Complex tasks are developed from sequential combinations of parameterized task primitives and recorded teleoperations, and are tested by execution on a graphics simulator and/or local robot actuator, together with adjustable time delays. The novel features of this invention include the shared and supervisory control of the remote robot manipulator via operator interface by pretested complex tasks sequences based on sequences of parameterized task primitives combined with further teleoperation and run-time binding of parameters based on task context.

  6. Insecticides and Biological Control

    ERIC Educational Resources Information Center

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  7. Technologies for Legionella Control

    EPA Science Inventory

    Presentation includes a review of new Office of Water document entitled "Technologies for Legionella Control in Premise Plumbing Systems", and discussion on ORD research projects involving Legionella and disinfection.

  8. Tight Diabetes Control

    MedlinePlus

    ... Size: A A A Listen En Español Tight Diabetes Control Keeping your blood glucose levels as close ... and syringes, than before. What About Type 2 Diabetes? The DCCT studied only people with type 1 ...

  9. Thermal control canister

    NASA Technical Reports Server (NTRS)

    Ollendorf, S. (Inventor)

    1979-01-01

    An apparatus for maintaining a heat dissipating load at a substantially constant temperature, and more particularly, to such an apparatus where in variable conductance heat pipes control the radiating area of a radiator is described.

  10. Birth control after 1984.

    PubMed

    Djerassi, C

    1970-09-04

    1) Eric Blair (alias George Orwell) can rest easy in his grave, because birth control by governmentally imposed methods, such as incorporation of a contraceptive agent into drinking water, is totally unfeasible by 1984. 2) Fundamentally new birth control procedures in the female (for example, a once-a-month luteolytic or abortifacient agent) and a male contraceptive pill probably will not be developed until the 1980's at the earliest, and then only if major steps of the type outlined in this article are instituted in the early 1970's. Development during the next decade of practical new methods of birth control without important incentives for continued active participation by the pharmaceutical industry is highly unlikely. If none are developed, birth control in 1984 will not differ significantly from that of today.

  11. Soviet Mission Control Center

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This photo is an overall view of the Mission Control Center in Korolev, Russia during the Expedition Seven mission. The Expedition Seven crew launched aboard a Soyez spacecraft on April 26, 2003. Photo credit: NASA/Bill Ingalls

  12. Control system testing

    NASA Astrophysics Data System (ADS)

    Whittler, W. H.; Collart, R. E.

    1984-08-01

    A three stage process of ground testing of the Space Telescope Pointing Control System is used for verification prior to on-orbit operation. First, development tests are conducted in a laboratory environment using flight/engineering model control sensor and actuators configured with an engineering model of the flight computer and data management system breadboards. These development tests validate the results of computer simulations predicting control system performance. Integration tests bring together flight system elements and software interfaced to a software simulation of vehicle dynamics to confirm closed loop performance. The final ground test phase, flight systems testing, is conducted on the fully assembled Space Telescope, verifies interfaces with the Fine Guidance Sensors and includes a thermal vacuum testing period. During the final test phase, the Point Control System is exercised with the dynamics simulator running in real time.

  13. Solid state power controllers

    NASA Technical Reports Server (NTRS)

    Gibbs, R. S.

    1973-01-01

    The rationale, analysis, design, breadboarding and testing of the incremental functional requirements are reported that led to the development of prototype 1 and 5 Amp dc and 1 Amp ac solid state power controllers (SSPC's). The SSPC's are to be considered for use as a replacement of electro-mechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 Vdc. They have the advantage over conventional relay/circuit breaker systems in that they can be located near utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small guage wire for control, computer interface, logic, electrical multiplexing, unboard testing, and power management and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability.

  14. Model-free control

    NASA Astrophysics Data System (ADS)

    Fliess, Michel; Join, Cédric

    2013-12-01

    'Model-free control'and the corresponding 'intelligent' PID controllers (iPIDs), which already had many successful concrete applications, are presented here for the first time in an unified manner, where the new advances are taken into account. The basics of model-free control is now employing some old functional analysis and some elementary differential algebra. The estimation techniques become quite straightforward via a recent online parameter identification approach. The importance of iPIs and especially of iPs is deduced from the presence of friction. The strange industrial ubiquity of classic PIDs and the great difficulty for tuning them in complex situations is deduced, via an elementary sampling, from their connections with iPIDs. Several numerical simulations are presented which include some infinite-dimensional systems. They demonstrate not only the power of our intelligent controllers but also the great simplicity for tuning them.

  15. Advances in Process Control.

    ERIC Educational Resources Information Center

    Morrison, David L.; And Others

    1982-01-01

    Advances in electronics and computer science have enabled industries (pulp/paper, iron/steel, petroleum/chemical) to attain better control of their processes with resulting increases in quality, productivity, profitability, and compliance with government regulations. (JN)

  16. Mission Control Roses

    NASA Video Gallery

    The 110th bouquet of roses arrived in Mission Control on Saturday, July 9, 2011. They were sent as quietly as they have been for more than 23 years by a family near Dallas, Texas. For 110 shuttle m...

  17. Robust Adaptive Control

    NASA Technical Reports Server (NTRS)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  18. Neural Architectures for Control

    NASA Technical Reports Server (NTRS)

    Peterson, James K.

    1991-01-01

    The cerebellar model articulated controller (CMAC) neural architectures are shown to be viable for the purposes of real-time learning and control. Software tools for the exploration of CMAC performance are developed for three hardware platforms, the MacIntosh, the IBM PC, and the SUN workstation. All algorithm development was done using the C programming language. These software tools were then used to implement an adaptive critic neuro-control design that learns in real-time how to back up a trailer truck. The truck backer-upper experiment is a standard performance measure in the neural network literature, but previously the training of the controllers was done off-line. With the CMAC neural architectures, it was possible to train the neuro-controllers on-line in real-time on a MS-DOS PC 386. CMAC neural architectures are also used in conjunction with a hierarchical planning approach to find collision-free paths over 2-D analog valued obstacle fields. The method constructs a coarse resolution version of the original problem and then finds the corresponding coarse optimal path using multipass dynamic programming. CMAC artificial neural architectures are used to estimate the analog transition costs that dynamic programming requires. The CMAC architectures are trained in real-time for each obstacle field presented. The coarse optimal path is then used as a baseline for the construction of a fine scale optimal path through the original obstacle array. These results are a very good indication of the potential power of the neural architectures in control design. In order to reach as wide an audience as possible, we have run a seminar on neuro-control that has met once per week since 20 May 1991. This seminar has thoroughly discussed the CMAC architecture, relevant portions of classical control, back propagation through time, and adaptive critic designs.

  19. Supercavitating Vehicle Control

    DTIC Science & Technology

    2008-10-10

    herein as winglets , are supported by a strut attached to the vehicle. The angle of attack of each winglet is controlled by a winglet actuator. The... winglet assembly may be extended into or retracted from the water by means of a spring-loaded actuated mount, which pivots the strut supporting the... winglet . When fully retracted, the winglet assembly is contained completely within the cavity. [0014] The segmented ring wing is controlled by one or more

  20. Understanding Command and Control

    DTIC Science & Technology

    2006-01-01

    and Control are fractal concepts. They can be applied to all subsets of an enterprise; to the functions performed; to the levels of the organizations...to the focus of the activity, whether strategic or tactical. Membership in these fractals may overlap with individual entities and groups...belonging to multiple fractals dynamically. • Different Command and Control Approaches will be appropriate for different sets of purposes or circumstances

  1. JPRS Report, Arms Control.

    DTIC Science & Technology

    2007-11-02

    automated control systems, computerized complexes, high-speed computers capable of millions of operations a second and having a formidable memory; we have...be, since we do not yet know the number of tranports : how many lorries and what type. [Reporter] Will the Polish side have any control whatso... technology to Iraq when the Gulf crisis erupted. After stating that Brazil has no chemical weapons, Rezek justified the agreement. Rezek said: It is

  2. Test Control Center exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  3. Drone Control System

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Drones, subscale vehicles like the Firebees, and full scale retired military aircraft are used to test air defense missile systems. The DFCS (Drone Formation Control System) computer, developed by IBM (International Business Machines) Federal Systems Division, can track ten drones at once. A program called ORACLS is used to generate software to track and control Drones. It was originally developed by Langley and supplied by COSMIC (Computer Software Management and Information Center). The program saved the company both time and money.

  4. GPS Control Segment Improvements

    DTIC Science & Technology

    2015-04-29

    Systems Center GPS Control Segment Improvements Mr. Tim McIntyre GPS Product Support Manager GPS Ops Support and Sustainment Division Peterson...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...DATE 29 APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE GPS Control Segment Improvements 5a. CONTRACT

  5. TACS Central Control Facility.

    DTIC Science & Technology

    1981-02-12

    Central Control Facility 6 3. System Management Data Flow 7 B. Hardware Operating Environment 9 1. Computer 9 2. TACS Interfaces 9 3. Other Central...TERMINATION TIMING 131 Appendix C SYSTEM MANAGEMENT DATA FORMATS 135 Appendix D FIVE- AND NINE-SLOT SYSTEM IMPLEMENTATION DIFFERENCES 147 Appendix E...control burst management ) 26 2-7 Call Progress Messages 29 2-8 Flowchart of Assignment/Blockage Decision Process for All-Member Net Requests 30 2-9

  6. GPS Control Segment

    DTIC Science & Technology

    2015-04-29

    AND MISSILE SYSTEMS CENTER • Provides GPS Ill SV command and control • NAV capability equivalent to GPS IIF (legacy and modern signals) - No L 1 ...Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number 1 . REPORT DATE 29 APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00

  7. Digital flight control research

    NASA Technical Reports Server (NTRS)

    Potter, J. E.; Stern, R. G.; Smith, T. B.; Sinha, P.

    1974-01-01

    The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator.

  8. Adaptive and Nonlinear Control

    DTIC Science & Technology

    1992-02-29

    in [22], we also applied the concept of zero dynamics to the problem of exact linearization of a nonlinear control system by dynamic feedback. Exact ...nonlinear systems, although it was well-known that the conditions for exact linearization are very stringent and consequently do not apply to a broad...29th IEEE Conference n Decision and Control, Invited Paper delivered by Dr. Gilliam. Exact Linearization of Zero Dynamics, 29th IEEE Conference on

  9. Flight Trajectory Control Investigation

    DTIC Science & Technology

    1981-03-01

    control algorithms for four-dimensional guidance of a transport air- craft were investigated for feasibility. Cost function constraints on the ptimal...21 3.1.6 Solution Constraints .... ............. ... 25 3.1.7 Trajectory Generator Review .. ......... .. 25 3.2 OPTIMAl CONTROLLER ALGORITHM...value formulation to a six-degree-of-freedom point mass aircraft with all the structural, maneuver, and mission constraints accounted for by using pelalty

  10. The ompB Operon Partially Determines Differential Expression of OmpC in Salmonella typhi and Escherichia coli

    PubMed Central

    Martínez-Flores, Irma; Cano, Roxana; Bustamante, Víctor H.; Calva, Edmundo; Puente, José Luis

    1999-01-01

    Expression of the Escherichia coli OmpC and OmpF outer membrane proteins is regulated by the osmolarity of the culture media. In contrast, expression of OmpC in Salmonella typhi is not influenced by osmolarity, while OmpF is regulated as in E. coli. To better understand the lack of osmoregulation of OmpC expression in S. typhi, we compared the expression of the ompC gene in S. typhi and E. coli, using ompC-lacZ fusions and outer membrane protein (OMP) electrophoretic profiles. S. typhi ompC expression levels in S. typhi were similar at low and high osmolarity along the growth curve, whereas osmoregulation of E. coli ompC in E. coli was observed during the exponential phase. Both genes were highly expressed at high and low osmolarity when present in S. typhi, while expression of both was regulated by osmolarity in E. coli. Complementation experiments with either the S. typhi or E. coli ompB operon in an S. typhi ΔompB strain carrying the ompC-lacZ fusions showed that both S. typhi and E. coli ompC were not regulated by osmolarity when they were under the control of S. typhi ompB. Interestingly, in the same strain, both genes were osmoregulated under E. coli ompB. Surprisingly, in E. coli ΔompB, they were both osmoregulated under S. typhi or E. coli ompB. Thus, the lack of osmoregulation of OmpC expression in S. typhi is determined in part by the ompB operon, as well as by other unknown trans-acting elements present in S. typhi. PMID:9882670

  11. Differential Effects of Dimethylsulfoniopropionate, Dimethylsulfonioacetate, and Other S-Methylated Compounds on the Growth of Sinorhizobium meliloti at Low and High Osmolarities

    PubMed Central

    Pichereau, Vianney; Pocard, Jean-Alain; Hamelin, Jack; Blanco, Carlos; Bernard, Théophile

    1998-01-01

    An extract from the marine alga Ulva lactuca was highly osmoprotective in salt-stressed cultures of Sinorhizobium meliloti 102F34. This beneficial activity was due to algal 3-dimethylsulfoniopropionate (DMSP), which was accumulated as a dominant compatible solute and strongly reduced the accumulation of endogenous osmolytes in stressed cells. Synthetic DMSP also acted as a powerful osmoprotectant and was accumulated as a nonmetabolizable cytosolic osmolyte (up to a concentration of 1,400 nmol/mg of protein) throughout the growth cycles of the stressed cultures. In contrast, 2-dimethylsulfonioacetate (DMSA), the sulfonium analog of the universal osmoprotectant glycine betaine (GB), was highly toxic to unstressed cells and was not osmoprotective in stressed cells of wild-type strains of S. meliloti. Nonetheless, the transport and accumulation of DMSA, like the transport and accumulation of DMSP and GB, were osmoregulated and increased fourfold in stressed cells of strain 102F34. Strikingly, DMSA was not toxic and became highly osmoprotective in mutants that are impaired in their ability to demethylate GB and DMSA. Furthermore, 2-methylthioacetate and thioglycolic acid (TGA), the demethylation products of DMSA, were excreted, apparently as a mechanism of cellular detoxification. Also, exogenous TGA and DMSA displayed similar inhibitory effects in strain 102F34. Thus, on the basis of these findings and other physiological and biochemical evidence, we infer that the toxicity of DMSA in wild-type strains of S. meliloti stems from its catabolism via the GB demethylation pathway. This is the first report describing the toxicity of DMSA in any organism and a metabolically stable osmoprotectant (DMSP) in S. meliloti. PMID:16349544

  12. Astrocytic and neuronal accumulation of elevated extracellular K(+) with a 2/3 K(+)/Na(+) flux ratio-consequences for energy metabolism, osmolarity and higher brain function.

    PubMed

    Hertz, Leif; Xu, Junnan; Song, Dan; Yan, Enzhi; Gu, Li; Peng, Liang

    2013-01-01

    Brain excitation increases neuronal Na(+) concentration by 2 major mechanisms: (i) Na(+) influx caused by glutamatergic synaptic activity; and (ii) action-potential-mediated depolarization by Na(+) influx followed by repolarizating K(+) efflux, increasing extracellular K(+) concentration. This review deals mainly with the latter and it concludes that clearance of extracellular K(+) is initially mainly effectuated by Na(+),K(+)-ATPase-mediated K(+) uptake into astrocytes, at K(+) concentrations above ~10 mM aided by uptake of Na(+),K(+) and 2 Cl(-) by the cotransporter NKCC1. Since operation of the astrocytic Na(+),K(+)-ATPase requires K(+)-dependent glycogenolysis for stimulation of the intracellular ATPase site, it ceases after normalization of extracellular K(+) concentration. This allows K(+) release via the inward rectifying K(+) channel Kir4.1, perhaps after trans-astrocytic connexin- and/or pannexin-mediated K(+) transfer, which would be a key candidate for determination by synchronization-based computational analysis and may have signaling effects. Spatially dispersed K(+) release would have little effect on extracellular K(+) concentration and allow K(+) accumulation by the less powerful neuronal Na(+),K(+)-ATPase, which is not stimulated by increases in extracellular K(+). Since the Na(+),K(+)-ATPase exchanges 3 Na(+) with 2 K(+), it creates extracellular hypertonicity and cell shrinkage. Hypertonicity stimulates NKCC1, which, aided by β-adrenergic stimulation of the Na(+),K(+)-ATPase, causes regulatory volume increase, furosemide-inhibited undershoot in [K(+)]e and perhaps facilitation of the termination of slow neuronal hyperpolarization (sAHP), with behavioral consequences. The ion transport processes involved minimize ionic disequilibria caused by the asymmetric Na(+),K(+)-ATPase fluxes.

  13. The Incidence, Classification, and Management of Acute Adverse Reactions to the Low-Osmolar Iodinated Contrast Media Isovue and Ultravist in Contrast-Enhanced Computed Tomography Scanning

    PubMed Central

    Zhang, Bin; Dong, Yuhao; Liang, Long; Lian, Zhouyang; Liu, Jing; Luo, Xiaoning; Chen, Wenbo; Li, Xinyu; Liang, Changhong; Zhang, Shuixing

    2016-01-01

    Abstract Some epidemiologic surveillance studies have recorded adverse drug reactions to radiocontrast agents. We aimed to investigate the incidence and management of acute adverse reactions (AARs) to Ultravist-370 and Isovue-370 in patients who underwent contrast-enhanced computed tomography (CT) scanning. Data from 137,473 patients were analyzed. They had undergone enhanced CT scanning with intravenous injection of Ultravist-370 or Isovue-370 during the period of January 1, 2006 to December 31, 2012 in our hospital. We investigated and classified AARs according to the American College of Radiology and the Chinese Society of Radiology (CSR) guidelines for iodinated contrast media. We analyzed risk factors for AARs and compared the AARs induced by Ultravist-370 and Isovue-370. Four hundred and twenty-eight (0.31%) patients experienced AARs, which included 330 (0.24%) patients with mild AARs, 82 (0.06%) patients with moderate AARs, and 16 (0.01%) patients with severe AARs (including 3 cases of cardiac arrest and one case of death). The incidence of AARs was higher with Ultravist-370 than with Isovue-370 (0.38% vs 0.24%, P < 0.001), but only for mild AARs (0.32% vs 0.16%, P < 0.001). Analyses on risk factors indicated that female patients (n = 221, 0.43%, P < 0.001), emergency patients (n = 11, 0.51%, P < 0.001), elderly patients aged 50 to 60 years (n = 135, 0.43%, P < 0.001), and patients who underwent coronary computed tomography angiography (CTA) (n = 55, 0.51%, P < 0.001) had a higher risk of AARs. Cutaneous manifestations (50.52%)—especially rash (59.74%)—were the most frequent mild AARs. Cardiovascular manifestations accounted for most moderate and severe AARs (62.91% and 48.28%, respectively). After proper management, the symptoms and signs of 96.5% of the AARs resolved within 24 hours without sequelae. Ultravist-370 and Isovue-370 are safe for patients undergoing enhanced CT scanning. The incidence of AARs is higher with Ultravist-370 than with Isovue-370, but this difference is limited only to the mild AARs. The incidence of AARs could be affected by multiple factors. PMID:27015204

  14. Differences in the Regulation of Ochratoxin A by the HOG Pathway in Penicillium and Aspergillus in Response to High Osmolar Environments

    PubMed Central

    Stoll, Dominic; Schmidt-Heydt, Markus; Geisen, Rolf

    2013-01-01

    Penicillium verrucosum, P. nordicum and Aspergillus carbonarius are three important ochratoxin A producing species. P. verrucosum is in addition able to produce citrinin. It has been shown earlier that P. nordicum is adapted to NaCl rich environments like salt rich dry cured foods or even salines. In this organism, the biosynthesis of ochratoxin A plays an adaptive role in this habitat. P. verrucosum generally can be found on cereals, but occasionally also on salt rich dry cured foods. In contrast A. carbonarius usually cannot be found in NaCl rich environments, but it occurs in another environment with high concentration of solutes, e.g., in sugar rich substrates like grapes and grape juices. Usually osmotic challenging conditions activate the HOG MAP kinase signal cascade, which in turn activates various osmo-regulated genes. In the current analysis, it could be demonstrated that in case of P. nordicum and P. verrucosum the NaCl induced production of ochratoxin A is correlated to the phosphorylation status of the HOG MAP kinase. Just the opposite was true for A. carbonarius. In this case, also higher amounts of NaCl in the medium lead to an increased phosphorylation status of HOG, but no increase in ochratoxin biosynthesis was observed. In contrast to the Penicillia, higher NaCl concentrations lead to a rapid cessation of growth by A. carbonarius. High glucose concentrations have much less impact on growth and the phosphorylation of HOG. PMID:23877195

  15. Thoracic damage control surgery.

    PubMed

    Gonçalves, Roberto; Saad, Roberto

    2016-01-01

    The damage control surgery came up with the philosophy of applying essential maneuvers to control bleeding and abdominal contamination in trauma patients who are within the limits of their physiological reserves. This concept was extended to thoracic injuries, where relatively simple maneuvers can shorten operative time of in extremis patients. This article aims to revise the various damage control techniques in thoracic organs that must be known to the surgeon engaged in emergency care. RESUMO A cirurgia de controle de danos surgiu com a filosofia de se aplicar manobras essenciais para controle de sangramento e contaminação abdominal, em doentes traumatizados, nos limites de suas reservas fisiológicas. Este conceito se estendeu para as lesões torácicas, onde manobras relativamente simples, podem abreviar o tempo operatório de doentes in extremis. Este artigo tem como objetivo, revisar as diversas técnicas de controle de dano em órgãos torácicos, que devem ser de conhecimento do cirurgião que atua na emergência.

  16. Failure of chaos control

    PubMed

    van De Water W; de Weger J

    2000-11-01

    We study the control of chaos in an experiment on a parametrically excited pendulum whose excitation mechanism is not perfect. This imperfection leads to a weakly excited degree of freedom with an associated small eigenvalue. Although the state of the pendulum could be characterized well and although the perturbation is weak, we fail to control chaos. From a numerical model we learn that the small eigenvalue cannot be ignored when attempting control. However, the estimate of this eigenvalue from an (experimental) time series is elusive. The reason is that points in an experimental time series are distributed according to the natural measure. It is this extremely uneven distribution of points that thwarts attempts to measure eigenvalues that are very different. Another consequence of the phase-space distribution of points for control is the occurrence of logarithmic-oscillations in the waiting time before control can be attempted. We come to the conclusion that chaos needs to be destroyed before the information needed for its control can be obtained.

  17. Pit disassembly motion control

    SciTech Connect

    Christensen, L.; Pittman, P. C.

    2001-01-01

    A Department of Energy (DOE) Pit Disassembly and Conversion Facility (PDCF) is being designed for the Savannah River Site in South Carolina. The facility will recover plutonium from excess nuclear weapon pits defined in START II and START III treaties. The plutonium will be stored and used to produce mixed oxide reactor fuel at another new DOE facility. Because of radiation dose issues, much of the pit disassembly work and material transfer will be automated. Automated material handling systems will interface with disassembly lathes, conversion reactors that produce oxide for storage, robotic container welding stations, vault retrieval systems, and nondestructive assay (NDA) instrumentation. The goal is to use common motion control hardware for material transfer and possibly common motion controllers for the unique PDCF systems. The latter is complicated by the different directions manufactures are considering for distributed control, such as Firewire, SERCOS, etc., and by the unique control requirements of machines such as lathes compared to controls for an integrated NDA system. The current design approach is to standardize where possible, use network cables to replace wire bundles where possible, but to first select hardware and motion controllers that meet specific machine or process requirements.

  18. Integrated airframe propulsion control

    NASA Technical Reports Server (NTRS)

    Fennell, R. E.; Black, S. B.

    1982-01-01

    Perturbation equations which describe flight dynamics and engine operation about a given operating point are combined to form an integrated aircraft/propulsion system model. Included in the model are the dependence of aerodynamic coefficients upon atmospheric variables along with the dependence of engine variables upon flight condition and inlet performance. An off-design engine performance model is used to identify interaction parameters in the model. Inclusion of subsystem interaction effects introduces coupling between flight and propulsion variables. To analyze interaction effects on control, consideration is first given to control requirements for separate flight and engine models. For the separate airframe model, feedback control provides substantial improvement in short period damping. For the integrated system, feedback control compensates for the coupling present in the model and provides good overall system stability. However, this feedback control law involves many non-zero gains. Analysis of suboptimal control strategies indicates that performance of the closed loop integrated system can be maintained with a feedback matrix in which the number of non-zero gains is small relative to the number of components in the feedback matrix.

  19. Optical beam jitter control

    NASA Astrophysics Data System (ADS)

    Watkins, R. Joseph; Chen, Hong-Jen; Agrawal, Brij N.; Shin, Young S.

    2004-06-01

    For several future imaging and communications spacecraft, a challenging area of technology development is the fine acquisition, tracking, and pointing (ATP) control of the spacecraft and its payload. For example, some spacecraft with large aperture(s) in the range of 10~30 m diameter requires a few arc-seconds accuracy, 10~15 nano-radians jitter, and a fast slewing rate to acquire the target. Furthermore these stringent requirements are at risk of great structure and control interactions. This paper we will focus on the control of optical beam jitter. A Laser Jitter Control (LJC) testbed has been constructed to test jitter algorithms. The testbed consists of two fast steering mirrors (FSM), three position sensing modules (PSM), one diode laser, and several beam splitters and mirrors, all on an isolated Newport optical bench. Jitter is injected with one FSM and the other FSM is used to control it. The jitter spectrum, representing the on-orbit spacecraft and beam jitter environment, contains not only narrow band noise due to rotating devices such as gyroscopes and reaction wheels but also broadband noise. The performance of a Wiener Filter-adaptive algorithm with ideal reference signal is established as the baseline for comparison of adaptive control methods in suppressing both broadband and narrowband disturbances. Specifically, the Least Mean Squares (LMS) approach and the Gradient Adaptive Lattice (GAL) approach are investigated during these experiments.

  20. Postoperative vasopressin and copeptin levels in noncardiac surgery patients: a prospective controlled trial.

    PubMed

    Jochberger, Stefan; Zitt, Matthias; Luckner, Günter; Mayr, Viktoria D; Wenzel, Volker; Ulmer, Hanno; Morgenthaler, Nils G; Hasibeder, Walter R; Dünser, Martin W

    2009-02-01

    Further information on the endogenous arginine vasopressin (AVP) response in patients with postoperative systemic inflammatory response syndrome (SIRS) and vasodilatory shock would provide more insight into the pathophysiology of SIRS-associated cardiovascular failure and help indicate AVP therapy. Patients after uncomplicated abdominal surgery without SIRS (n = 10), critically ill patients after noncardiac surgery with SIRS (n = 9), and patients with SIRS plus vasodilatory shock (n = 22) were included in this prospective trial. Plasma AVP (radioimmunoassay) and copeptin (immunoluminometric assay) concentrations together with clinical parameters were documented daily during the first 7 days postoperative. The AVP response significantly differed between the three groups. Patients without SIRS had lower AVP concentrations than SIRS patients with (P = 0.001) or without shock (P = 0.003). Patients with SIRS and shock had higher AVP levels than patients with SIRS alone (P < 0.001). Arginine vasopressin decreased over time (P = 0.007) in all groups. At day 28, nonsurvivors had higher AVP levels than did survivors (P < 0.001). In SIRS patients without shock, serum osmolarity was indirectly associated with AVP levels, whereas mean arterial blood pressure and serum osmolarity were associated with AVP in SIRS patients with shock. Arginine vasopressin and copeptin correlated significantly with each other (P < 0.001; r = 0.76). In patients without hemofiltration, copeptin levels predicted 28-day mortality with high sensitivity and specificity. The postoperative AVP response in noncardiac surgery patients seems well maintained. The possibility that AVP plays a contributory role in the failure to restore vascular tone in patients with vasodilatory shock cannot be excluded but seems less important than in septic or postcardiotomy shock.

  1. Space Shuttle flight control system

    NASA Technical Reports Server (NTRS)

    Klinar, W. J.; Kubiak, E. T.; Peters, W. H.; Saldana, R. L.; Smith, E. E., Jr.; Stegall, H. W.

    1975-01-01

    The Space Shuttle is a control stabilized vehicle with control provided by an all digital, fly-by-wire flight control system. This paper gives a description of the several modes of flight control which correspond to the Shuttle mission phases. These modes are ascent flight control (including open loop first stage steering, the use of four computers operating in parallel and inertial guidance sensors), on-orbit flight control (with a discussion of reaction control, phase plane switching logic, jet selection logic, state estimator logic and OMS thrust vector control), entry flight control and TAEM (terminal area energy management to landing). Also discussed are redundancy management and backup flight control.

  2. Controlled Quantum Packets

    NASA Technical Reports Server (NTRS)

    DeMartino, Salvatore; DeSiena, Silvio

    1996-01-01

    We look at time evolution of a physical system from the point of view of dynamical control theory. Normally we solve motion equation with a given external potential and we obtain time evolution. Standard examples are the trajectories in classical mechanics or the wave functions in Quantum Mechanics. In the control theory, we have the configurational variables of a physical system, we choose a velocity field and with a suited strategy we force the physical system to have a well defined evolution. The evolution of the system is the 'premium' that the controller receives if he has adopted the right strategy. The strategy is given by well suited laboratory devices. The control mechanisms are in many cases non linear; it is necessary, namely, a feedback mechanism to retain in time the selected evolution. Our aim is to introduce a scheme to obtain Quantum wave packets by control theory. The program is to choose the characteristics of a packet, that is, the equation of evolution for its centre and a controlled dispersion, and to give a building scheme from some initial state (for example a solution of stationary Schroedinger equation). It seems natural in this view to use stochastic approach to Quantum Mechanics, that is, Stochastic Mechanics [S.M.]. It is a quantization scheme different from ordinary ones only formally. This approach introduces in quantum theory the whole mathematical apparatus of stochastic control theory. Stochastic Mechanics, in our view, is more intuitive when we want to study all the classical-like problems. We apply our scheme to build two classes of quantum packets both derived generalizing some properties of coherent states.

  3. Supervisory Control Strategy Development

    SciTech Connect

    Gary D. Storrick; Bojan Petrovic

    2007-02-28

    Task 4 of this collaborative effort between ORNL, Brazil, and Westinghouse for the International Nuclear Energy Research Initiative entitled “Development of Advanced Instrumentation and Control for an Integrated Primary System Reactor” focused on the design of the hierarchical supervisory control for multiple-module units. The state of the IRIS plant design – specifically, the lack of a detailed secondary system design – made developing a detailed hierarchical control difficult at this time. However, other simultaneous and ongoing efforts have contributed to providing the needed information. This report summarizes the results achieved under Task 4 of this Financial Assistance Award. Section 1.2 describes the scope of this effort. Section 2 discusses the IRIS control functions. Next, it briefly reviews the current control concepts, and then reviews the maneuvering requirements for the IRIS plant. It closes by noting the benefits that automated sequences have in reducing operator workload. Section 3 examines reactor loading in the frequency domain to establish some guidelines for module operation, paying particular attention to strategies for using process steam for desalination and/or district heating. The final subsection discusses the implications for reactor control, and argues that using the envisioned percentage (up to 10%) of the NSSS thermal output for these purposes should not significantly affect the NSSS control strategies. Section 4 uses some very general economic assumptions to suggest how one should approach multi-module operation. It concludes that the well-known algorithms used for economic dispatching could be used to help manage a multi-unit IRIS site. Section 5 addresses the human performance factors of multi-module operation. Section 6 summarizes our conclusions.

  4. Aligning Task Control with Desire for Control: Implications for Performance

    PubMed Central

    Ramsey, Alex T.; Etcheverry, Paul E.

    2015-01-01

    The current study examined whether matches between task control and participants' desire for control over their environment lead to better task performance than mismatches. Work control and desire for control were manipulated, and participants engaged in timed tasks. As predicted, performance was higher in cases of match, even when task control and desire for control were low. Task control and desire for control may predict work performance in combination, highlighting the importance of Person-Environment Fit theory for both selection and work design. By manipulating desire for control, our research also explores the potentially state-dependent quality of this individual difference variable. PMID:26045630

  5. Aligning Task Control with Desire for Control: Implications for Performance.

    PubMed

    Ramsey, Alex T; Etcheverry, Paul E

    The current study examined whether matches between task control and participants' desire for control over their environment lead to better task performance than mismatches. Work control and desire for control were manipulated, and participants engaged in timed tasks. As predicted, performance was higher in cases of match, even when task control and desire for control were low. Task control and desire for control may predict work performance in combination, highlighting the importance of Person-Environment Fit theory for both selection and work design. By manipulating desire for control, our research also explores the potentially state-dependent quality of this individual difference variable.

  6. 13. CONTROL ROOM OF GENE PUMPING STATION. CONTROL CUBICLES ARRAYED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. CONTROL ROOM OF GENE PUMPING STATION. CONTROL CUBICLES ARRAYED BEHIND MANAGER'S ART DECO-STYLE CONTROL DESK, WITH CONTROL CUBICLE 1 AT FAR RIGHT AND CONTROL CUBICLE 9 AT FAR LEFT. - Gene Pump Plant, South of Gene Wash Reservoir, 2 miles west of Whitsett Pump Plant, Parker Dam, San Bernardino County, CA

  7. Resource Balancing Control Allocation

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Bodson, Marc

    2010-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the control effort. The paper discusses the alternative choice of using the l1 norm for minimization of the tracking error and a normalized l(infinity) norm, or sup norm, for minimization of the control effort. The algorithm computes the norm of the actuator deflections scaled by the actuator limits. Minimization of the control effort then translates into the minimization of the maximum actuator deflection as a percentage of its range of motion. The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are investigated through examples. In particular, the min-max criterion results in a type of resource balancing, where the resources are the control surfaces and the algorithm balances these resources to achieve the desired command. A study of the sensitivity of the algorithms to the data is presented, which shows that the normalized l(infinity) algorithm has the lowest sensitivity, although high sensitivities are observed whenever the limits of performance are reached.

  8. Electronically controlled automatic transmission

    SciTech Connect

    Ohkubo, M.; Shiba, H.; Nakamura, K.

    1989-03-28

    This patent describes an electronically controlled automatic transmission having a manual valve working in connection with a manual shift lever, shift valves operated by solenoid valves which are driven by an electronic control circuit previously memorizing shift patterns, and a hydraulic circuit controlled by these manual valve and shift valves for driving brakes and a clutch in order to change speed. Shift patterns of 2-range and L-range, in addition to a shift pattern of D-range, are memorized previously in the electronic control circuit, an operation switch is provided which changes the shift pattern of the electronic control circuit to any shift pattern among those of D-range, 2-range and L-range at time of the manual shift lever being in a D-range position, a releasable lock mechanism is provided which prevents the manual shift lever from entering 2-range and L-range positions, and the hydraulic circuit is set to a third speed mode when the manual shift lever is in the D-range position. The circuit is set to a second speed mode when it is in the 2-range position, and the circuit is set to a first speed mode when it is in the L-range position, respectively, in case where the shift valves are not working.

  9. A tactile control prosthesis

    NASA Astrophysics Data System (ADS)

    Perry, James Franklin

    This research involves development and testing of a tactile control prosthesis to aid human operators in control of dynamic vehicles. Specifically, this work includes development and demonstration of a torso mounted tactile drift display that allowed helicopter pilots to hover a Blackhawk helicopter with degraded vision (equivalent to 20/200 acuity), a NASA sponsored pilot-in-the-loop simulator study for a hover display and development and analysis of a tactile control prosthesis to help pilots correctly control an airplane experiencing an engine failure on takeoff. Results of a ten-subject experiment indicate that use of a tactile display in conjunction with a visual display reduces operator delay by 65 msec (SD of 28 msec), (P < 0.001) without a significant increase in error rate. In the pilot-in-the-loop simulation experiment pilots hovered a simulated helicopter better under increased workload conditions with the tactile control prosthesis than without it. The increased workload consisted of an addition drill in which the subject had to agree or disagree with a computer generated sum. Pilots were able to hover more precisely with the tactile display (mean of 5.19, SD of 2.57 feet) than without (mean of 6.39 and SD of 3.31 feet) especially when the secondary task was required (P < 0.001). Although learning effects were exhibited throughout the trials (P < 0.001), the tactile display was of greater benefit in higher workload conditions.

  10. Laser Ion Acceleration Control

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Nagashima, T.; Izumiyama, T.; Sato, D.; Takano, M.; Barada, D.; Ma, Y. Y.; Gu, Y. J.; Kong, Q.; Wang, P. X.; Wang, W. M.

    2013-10-01

    An intense femtosecond pulsed laser is employed to accelerate ions. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching, the ion particle energy control, etc. In the study particle computer simulations were performed to solve the issues, and each component was designed to control the ion beam quality. When an intense laser illuminates a target, electrons in the target are accelerated and leave from the target; temporarily a strong electric field is formed between the high-energy electrons and the target ions, and the target ions are accelerated. The energy efficiency from the laser to ions was improved by using a solid target with a fine sub-wavelength structure or by a near critical density gas plasma. The ion beam collimation was realized by holes behind the solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching were successfully realized by a multi-stage laser-target interaction. The present study proposed a novel concept for a future compact laser ion accelerator, based on each component study required to control the ion beam quality and parameters. Partly supported by JSPS, MEXT, CORE, Japan/US Cooperation program, ASHULA and ILE/Osaka University.

  11. Tobacco control in India.

    PubMed

    Shimkhada, Riti; Peabody, John W

    2003-01-01

    Legislation to control tobacco use in developing countries has lagged behind the dramatic rise in tobacco consumption. India, the third largest grower of tobacco in the world, amassed 1.7 million disability-adjusted life years (DALYs) in 1990 due to disease and injury attributable to tobacco use in a population where 65% of the men and 38% of the women consume tobacco. India's anti-tobacco legislation, first passed at the national level in 1975, was largely limited to health warnings and proved to be insufficient. In the last decade state legislation has increasingly been used but has lacked uniformity and the multipronged strategies necessary to control demand. A new piece of national legislation, proposed in 2001, represents an advance. It includes the following key demand reduction measures: outlawing smoking in public places; forbidding sale of tobacco to minors; requiring more prominent health warning labels; and banning advertising at sports and cultural events. Despite these measures, the new legislation will not be enough to control the demand for tobacco products in India. The Indian Government must also introduce policies to raise taxes, control smuggling, close advertising loopholes, and create adequate provisions for the enforcement of tobacco control laws.

  12. Nuclear reactor control column

    DOEpatents

    Bachovchin, Dennis M.

    1982-01-01

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

  13. Well pump controller

    SciTech Connect

    Pikna, R. G.

    1985-04-02

    A device for automatically controlling the pumping of fluids from a well of the type using a walking beam and positive displacement pump to provide efficient utilization of the pumping equipment and energy required therefor, and to obtain efficient flow rates from the wall. A sensor detects the position of the walking beam at a predetermined position on the up-stroke of its pumping cycle and generates a signal to a control unit. a diaphram detects the pressure differential between the well casing pressure and the fluid delivery tube pressure. The diaphram moves a spring biased plunger which actuates a switch upon a predetermined pressure differential existing between the casing and delivery tube which sends a second signal to the control unit. The control unit upon receiving both signals maintains the pumping unit energizes until the pressure differential on the diaphram drops to a predetermined value preventing the plunger from actuating the switch. The control unit will deenergize the pumping unit if both signals are not received at the appropriate time. The sensitivity of the diaphram actuated switch is adjustable by changing the biasing force of the spring on the plunger.

  14. Dynamics of immigration control.

    PubMed

    Djajic, S

    1999-01-01

    This paper examines the dynamic implications of US border control policies and internal enforcement measures for the pattern of illegal immigration and the sectoral allocation of clandestine foreign workers. Efforts to counteract illegal immigration into the US have been increasing steadily following the passage of the Immigration Reform and Control Act of 1986. The purpose of the Act is to reduce illegal immigration with the aid of three instruments: 1) employer sanctions; 2) increased controls along the border; and 3) a legalization program designed to meet the existing demand for agricultural labor in geographic locations that are in proximity of Mexico, the principal source of clandestine foreign labor. The effect of tougher border control measures increases the cost of illegal entry, discouraging clandestine inflows. On the other hand, these measures induce migrants to increase their own anti-detection efforts, reducing the probability of detection and the deportation rate. If the latter effect should dominate, the steady-state stock of clandestine foreign labor will actually increase in response to more vigorous border control measures. Explicit consideration of the role of networks in the clandestine labor market suggests the need for a drastic policy change. This policy change should target illegal migration in areas with high concentrations of clandestine foreign workers. Complementary measures should accompany this policy change to prevent unbalanced enforcement measures.

  15. Aquatic plant control research

    SciTech Connect

    Pryfogle, P.A.; Rinehart, B.N.; Ghio, E.G.

    1997-05-01

    The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

  16. Tobacco control in India.

    PubMed Central

    Shimkhada, Riti; Peabody, John W.

    2003-01-01

    Legislation to control tobacco use in developing countries has lagged behind the dramatic rise in tobacco consumption. India, the third largest grower of tobacco in the world, amassed 1.7 million disability-adjusted life years (DALYs) in 1990 due to disease and injury attributable to tobacco use in a population where 65% of the men and 38% of the women consume tobacco. India's anti-tobacco legislation, first passed at the national level in 1975, was largely limited to health warnings and proved to be insufficient. In the last decade state legislation has increasingly been used but has lacked uniformity and the multipronged strategies necessary to control demand. A new piece of national legislation, proposed in 2001, represents an advance. It includes the following key demand reduction measures: outlawing smoking in public places; forbidding sale of tobacco to minors; requiring more prominent health warning labels; and banning advertising at sports and cultural events. Despite these measures, the new legislation will not be enough to control the demand for tobacco products in India. The Indian Government must also introduce policies to raise taxes, control smuggling, close advertising loopholes, and create adequate provisions for the enforcement of tobacco control laws. PMID:12640476

  17. Control of vortex breakdown

    NASA Astrophysics Data System (ADS)

    Husain, H.; Shtern, F.; Hussain, V.

    1996-11-01

    The paper develops means of vortex breakdown (VB) control with the help of Controlling Vortex Generators (CVGs). Vortex breakdown plays the crucial role in many practical swirling flows, e.g. (a) leading-edge vortices above delta wings create a strong lift and (b) trailing vortices behind large aircraft disturbances are potentially dangerous to subsequent aircraft. It is useful to prevent VB in case (a) and to stimulate VB in case (b). We have recently obtained significant theoretical and experimental results related to swirling flow prediction and control. Firstly, a theory has been developed which models jump transitions in swirling flow (e.g. jumps in VB locations) and predicts ranges of control parameters where multiple stable states occur. Secondly, our experiments have revealed that effective control (enhancement and suppression) of VB can be achieved using CVGs. In our experiments we have used a thin rotaing rod as a CVG, placed along the axis of the basic swirling flow in a sealed cylinder driven by the rotating bottom disc. The effect of the rod depends on the direction of the rotation. With increasing rod co-rotational speed, the VB 'bubble' (VBB) becomes smaller and then disappear, and a cone-shaped wake forms. Counter-rotation of the rod causes increases VBBs' diameter and makes the flow unsteady. The VBBs begin to advect downstream, undergo tearing and pairing, and, hence, enhance mixing.

  18. Thrust-Vector-Control System

    NASA Technical Reports Server (NTRS)

    Murray, Jonathan

    1992-01-01

    Control gains computed via matrix Riccati equation. Software-based system controlling aim of gimbaled rocket motor on spacecraft adaptive and optimal in sense it adjusts control gains in response to feedback, according to optimizing algorithm based on cost function. Underlying control concept also applicable, with modifications, to thrust-vector control on vertical-takeoff-and-landing airplanes, control of orientations of scientific instruments, and robotic control systems.

  19. Salivary Gland Secretion.

    ERIC Educational Resources Information Center

    Dorman, H. L.; And Others

    1981-01-01

    Describes materials and procedures for an experiment utilizing a live dog to demonstrate: (1) physiology of the salivary gland; (2) parasympathetic control of the salivary gland; (3) influence of varying salivary flow rates on sodium and potassium ions, osmolarity and pH; and (4) salivary secretion as an active process. (DS)

  20. FREEZING-POINT DEPRESSION: NEW METHOD FOR MEASURING ULTRAMICRO QUANTITIES OF FLUIDS.

    PubMed

    PRAGER, D J; BOWMAN, R L

    1963-10-11

    Accurate determination of the solute content of millimicroliter samples of biological fluids can conveniently be made with an instrument consisting of a thermoelectric cooler controlled by an electronic proportional servo system. Accuracies to within less than 2 percent have been achieved in determining the osmolarity of body fluids.

  1. Macrofouling control technology update

    SciTech Connect

    Tsou, J.L.; Armor, A.F.

    1996-12-31

    Macrofouling of condenser systems with debris, fish, clams, barnacles, mussels, algae, and other marine organisms can significantly affect power plant availability and performance. Typical difficulties include increased condenser back pressure due to reduced cooling-water flow, malfunctioning of on-line tube-cleaning equipment, and accelerated corrosion and erosion of tubing. In some severe cases, condenser back pressure increased to a point that the turbine had to be tripped. In 1981 EPRI initiated a research project to develop utility industry guidelines for reducing macrofouling problems. In 1987 EPRI published the Guidelines on Macrofouling Control Technology. Since then significant progress has been made by EPRI, utility members, equipment manufacturers, and others. The purpose of this paper is to update the macrofouling control technology. Control technology covered will include thermal treatment, mechanical removal devices, antifouling coatings, and chemical treatment.

  2. Dynamic PID loop control

    SciTech Connect

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.; /Fermilab

    2011-06-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  3. SERVOMOTOR CONTROL SYSTEM

    DOEpatents

    MacNeille, S.M.

    1958-12-01

    Control systems for automatic positioning of an electric motor operated vapor valve are described which is operable under the severe conditions existing in apparatus for electro-magnetlcally separating isotopes. In general, the system includes a rotor for turning the valve comprising two colls mounted mutually perpendicular to each other and also perpendicular to the magnetic field of the isotope separating apparatus. The coils are furnished with both a-c and d- c current by assoclate control circuitry and a position control is provided for varying the ratlo of the a-c currents in the coils and at the same time, but in an inverse manner, the ratio between the d-c currents in the coils is varied. With the present system the magnitude of the motor torque is constant for all valves of the rotor orientatlon angle.

  4. Control Techtronics International

    SciTech Connect

    West, J.

    1995-12-31

    Polish graded coal can be burned in existing stoker boilers and meet the 1998 Air Quality standard. This is accomplished with the Control Techtronics microprocessor-based combustion controller accurately and repeatedly: (a) matching the combustion air to the coal firing rate, with continuous stack sensor feedback; (b) continuously varying the boiler`s firing rate based on output water temperature or steam pressure; (c) continuously varying the exhaust fan`s speed to maintain minimum negative pressure in the boiler`s combustion chamber; and recirculating a portion of the flue gas, at varying amounts throughout the boiler`s firing rate. Systems for five boilers have been installed and are operating on MPEC`s Balicka plant in Krakow. Control Techtronics International has $10 million of U.S. Export-Import Bank funds available for similar projects throughout Poland.

  5. Test Control Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    At the test observation periscope in the Test Control Center exhibit in StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., visitors can observe a test of a Space Shuttle Main Engine exactly as test engineers might see it during a real engine test. The Test Control Center exhibit exactly simulates not only the test control environment, but also the procedure of testing a rocket engine. Designed to entertain while educating, StenniSphere includes informative dispays and exhibits from NASA's lead center for rocket propulsion and remote sensing applications. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  6. Autonomous Flying Controls Testbed

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.

    2005-01-01

    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  7. Vehicle speed control device

    SciTech Connect

    Thornton-Trump, W.E.

    1987-03-10

    An apparatus is described for automatically limiting the speed of a vehicle powered by an internal combustion engine having a spark ignition system with an ignition coil, comprising: sensor means for generating a speed signal directly representative of the speed of the vehicle comprising a series of speed signal pulses having a pulse repetition frequency proportional to the speed of the vehicle; control means for converting speed signal pulses into a DC voltage proportional to the vehicle speed; means for comparing the DC voltage to a predetermined DC voltage having substantially zero AC components representative of a predetermined maximum speed and for generating a difference signal in response thereto; and means for generating a pulse-width modulated control signal responsive to the difference signal; power means responsive to the control signal for intermittently interrupting the ignition system.

  8. [Environmental microbiological control].

    PubMed

    Martín Salas, Carmen; Tordoya Titichoca, Igberto J; Ezpeleta Baquedano, Carmen

    2016-07-01

    The environmental microbiological control is necessary to prevent infections associated with certain procedures that are performed at the hospital. In this review the procedures for control of water and dialysis fluids, and air in operating rooms and immunocompromised units are addressed. The dialysis quality management guidelines define the highest levels of chemical, microbiological and endotoxin in purified water and dialysis fluids based on the recommendations of scientific societies. The microbiological control of water and dialysis fluids should include detection of microorganisms and endotoxin levels. Regarding the microbiological air sampling of operating rooms and immunocompromised units the types of clean rooms in which is recommended to perform microbiological air monitoring; the sample collection methods; culture media; incubation conditions; the most common microorganisms, and permissible levels depending on the type of surgery are described.

  9. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Howard, D.F.; Motta, E.E.

    1961-06-27

    A method for controlling the excess reactivity in a nuclear reactor throughout the core life while maintaining the neutron flux distribution at the desired level is described. The control unit embodies a container having two electrodes of different surface area immersed in an electrolytic solution of a good neutron sbsorbing metal ion such as boron, gadolinium, or cadmium. Initially, the neutron absorber is plated on the larger electrode to control the greater neutron flux of a freshly refueled core. As the fuel burns up, the excess reactivity decreases and the neutron absorber is then plated onto the smaller electrode so that the number of neutrons absorbed also decreases. The excess reactivity in the core may thus be maintained without the introduction of serious perturbations in the neutron flux distributibn.

  10. Voltage controlled current source

    DOEpatents

    Casne, Gregory M.

    1992-01-01

    A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

  11. Electric turbocompound control system

    DOEpatents

    Algrain, Marcelo C.

    2007-02-13

    Turbocompound systems can be used to affect engine operation using the energy in exhaust gas that is driving the available turbocharger. A first electrical device acts as a generator in response to turbocharger rotation. A second electrical device acts as a motor to put mechanical power into the engine, typically at the crankshaft. Apparatus, systems, steps, and methods are described to control the generator and motor operations to control the amount of power being recovered. This can control engine operation closer to desirable parameters for given engine-related operating conditions compared to actual. The electrical devices can also operate in "reverse," going between motor and generator functions. This permits the electrical device associated with the crankshaft to drive the electrical device associated with the turbocharger as a motor, overcoming deficient engine operating conditions such as associated with turbocharger lag.

  12. CEBAF Control Room Renovation

    SciTech Connect

    Michael Spata; Thomas Oren

    2005-05-01

    The Machine Control Center (MCC) at Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facility's 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week maintenance period with no interruption to beam operations. We present the results of this effort.

  13. CEBAF Control Room Renovation

    SciTech Connect

    Michael Spata; Thomas Oren

    2005-05-01

    The Machine Control Center at Jefferson Lab's Continuous Electron Beam Accelerator Facility was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week period with no interruption to beam operations. We present the results of this effort.

  14. Distributed environmental control

    NASA Technical Reports Server (NTRS)

    Cleveland, Gary A.

    1992-01-01

    We present an architecture of distributed, independent control agents designed to work with the Computer Aided System Engineering and Analysis (CASE/A) simulation tool. CASE/A simulates behavior of Environmental Control and Life Support Systems (ECLSS). We describe a lattice of agents capable of distributed sensing and overcoming certain sensor and effector failures. We address how the architecture can achieve the coordinating functions of a hierarchical command structure while maintaining the robustness and flexibility of independent agents. These agents work between the time steps of the CASE/A simulation tool to arrive at command decisions based on the state variables maintained by CASE/A. Control is evaluated according to both effectiveness (e.g., how well temperature was maintained) and resource utilization (the amount of power and materials used).

  15. Power Systems Control Architecture

    SciTech Connect

    James Davidson

    2005-01-01

    A diagram provided in the report depicts the complexity of the power systems control architecture used by the national power structure. It shows the structural hierarchy and the relationship of the each system to those other systems interconnected to it. Each of these levels provides a different focus for vulnerability testing and has its own weaknesses. In evaluating each level, of prime concern is what vulnerabilities exist that provide a path into the system, either to cause the system to malfunction or to take control of a field device. An additional vulnerability to consider is can the system be compromised in such a manner that the attacker can obtain critical information about the system and the portion of the national power structure that it controls.

  16. Pattern, Growth and Control

    PubMed Central

    Lander, Arthur D.

    2011-01-01

    The view of biology as goal-directed engineering has deep historical roots in developmental biology, a field currently benefitting from an influx of ideas and methods from systems biology. Systems biology draws on non-biological paradigms to explain developmental mechanisms of control, the specific type of regulation that achieves or maintains a desired end. This review highlights some of the current efforts designed to elucidate basic design principles underlying the engineering objectives of robustness, precision, and scaling that are required during developmental control of growth and pattern formation. Examples from vertebrate and invertebrate development are used to illustrate general principles including the value of integral feedback in achieving set-point control; the usefulness of self-organizing behavior; the importance of recognizing and appropriately handling noise; and the No Free Lunch theory. Through the examination of such principles, systems biology offers a functional framework to make sense of the mechanistic complexity of organismal development. PMID:21414486

  17. Timing control system

    NASA Technical Reports Server (NTRS)

    Wiker, Gordon A. (Inventor); Wells, Jr., George H. (Inventor)

    1989-01-01

    A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not overshoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

  18. Timing Control System

    NASA Technical Reports Server (NTRS)

    Wiker, Gordon A. (Inventor); Wells, George H., Jr. (Inventor)

    1987-01-01

    A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not over shoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

  19. REACTOR CONTROL DEVICE

    DOEpatents

    Graham, R.H.

    1962-09-01

    A wholly mechanical compact control device is designed for automatically rendering the core of a fission reactor subcritical in response to core temperatures in excess of the design operating temperature limit. The control device comprises an expansible bellows interposed between the base of a channel in a reactor core and the inner end of a fuel cylinder therein which is normally resiliently urged inwardly. The bellows contains a working fluid which undergoes a liquid to vapor phase change at a temperature substantially equal to the design temperature limit. Hence, the bellows abruptiy expands at this limiting temperature to force the fuel cylinder outward and render the core subcritical. The control device is particularly applicable to aircraft propulsion reactor service. (AEC)

  20. Remote Controlled Orbiter Capability

    NASA Technical Reports Server (NTRS)

    Garske, Michael; delaTorre, Rafael

    2007-01-01

    The Remote Control Orbiter (RCO) capability allows a Space Shuttle Orbiter to perform an unmanned re-entry and landing. This low-cost capability employs existing and newly added functions to perform key activities typically performed by flight crews and controllers during manned re-entries. During an RCO landing attempt, these functions are triggered by automation resident in the on-board computers or uplinked commands from flight controllers on the ground. In order to properly route certain commands to the appropriate hardware, an In-Flight Maintenance (IFM) cable was developed. Currently, the RCO capability is reserved for the scenario where a safe return of the crew from orbit may not be possible. The flight crew would remain in orbit and await a rescue mission. After the crew is rescued, the RCO capability would be used on the unmanned Orbiter in an attempt to salvage this national asset.

  1. Timing control system

    NASA Astrophysics Data System (ADS)

    Wiker, Gordon A.; Wells, George H., Jr.

    1987-09-01

    A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not over shoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

  2. Innovative Control Effectors (ICE)

    DTIC Science & Technology

    1996-01-01

    S0.06- 0.05 Max A/B 1. ..... C 0.04 201-TV Control Power Available t Mil Power It 0.03- 201 Control Power Available [= !,-===:CPR Max /VB 0.01. CPR Mil...3 ’" t ~~~vl 1 ’ N’ -1018 1-\\ 101-4 -0.05 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 Yaw Power Figure 6-12 All Five Control Suites Can Achieve Level 1...SPLI" T LEADING EDGE FLAP • fELEVON WEAPONS BAY j-PITCH FLAP VECTORING NOZZLE F-22 LEADING EDGE FLAP F-22 AILERON POWER DRIVE ACTUATOR F-22 FLAPERON

  3. Mercury control in 2009

    SciTech Connect

    Sjostrom, S.; Durham, M.; Bustard, J.; Martin, C.

    2009-07-15

    Although activated carbon injection (ACI) has been proven to be effective for many configurations and is a preferred option at many plants sufficient quantities of powdered activated coking (PAC) must be available to meet future needs. The authors estimate that upcoming federal and state regulations will result in tripling the annual US demand for activated carbon to nearly 1.5 billion lb from approximately 450 million lb. Rapid expansion of US production capacity is required. Many PAC manufacturers are discussing expansion of their existing production capabilities. One company, ADA Carbon Solutions, is in the process of constructing the largest activated carbon facility in North America to meet the future demand for PAC as a sorbent for mercury control. Emission control technology development and commercialization is driven by regulation and legislation. Although ACI will not achieve > 90% mercury control at every plant, the expected required MACT legislation level, it offers promise as a low-cost primary mercury control technology option for many configurations and an important trim technology for others. ACI has emerged as the clear mercury-specific control option of choice, representing over 98% of the commercial mercury control system orders to date. As state regulations are implemented and the potential for a federal rule becomes more imminent, suppliers are continuing to develop technologies to improve the cost effectiveness and limit the balance of plant impacts associated with ACI and are developing additional PAC production capabilities to ensure that the industry's needs are met. The commercialisation of ACI is a clear example of industry, through the dedication of many individuals and companies with support from the DOE and EPRI, meeting the challenge of developing cost-effectively reducing emissions from coal-fired power plants. 7 refs., 1 fig.

  4. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  5. REACTOR CONTROL SYSTEM

    DOEpatents

    MacNeill, J.H.; Estabrook, J.Y.

    1960-05-10

    A reactor control system including a continuous tape passing through a first coolant passageway, over idler rollers, back through another parallel passageway, and over motor-driven rollers is described. Discrete portions of fuel or poison are carried on two opposed active sections of the tape. Driving the tape in forward or reverse directions causes both active sections to be simultaneously inserted or withdrawn uniformly, tending to maintain a more uniform flux within the reactor. The system is particularly useful in mobile reactors, where reduced inertial resistance to control rod movement is important.

  6. Instrument Attitude Precision Control

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan

    2004-01-01

    A novel approach is presented in this paper to analyze attitude precision and control for an instrument gimbaled to a spacecraft subject to an internal disturbance caused by a moving component inside the instrument. Nonlinear differential equations of motion for some sample cases are derived and solved analytically to gain insight into the influence of the disturbance on the attitude pointing error. A simple control law is developed to eliminate the instrument pointing error caused by the internal disturbance. Several cases are presented to demonstrate and verify the concept presented in this paper.

  7. AUTOMATIC FREQUENCY CONTROL SYSTEM

    DOEpatents

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  8. A microprogrammable radar controller

    NASA Technical Reports Server (NTRS)

    Law, D. C.

    1986-01-01

    The Wave Propagation Lab. has completed the design and construction of a microprogrammable radar controller for atmospheric wind profiling. Unlike some radar controllers using state machines or hardwired logic for radar timing, this design is a high speed programmable sequencer with signal processing resources. A block diagram of the device is shown. The device is a single 8 1/2 inch by 10 1/2 inch printed circuit board and consists of three main subsections: (1) the host computer interface; (2) the microprogram sequencer; and (3) the signal processing circuitry. Each of these subsections are described in detail.

  9. NASA control research overview

    NASA Technical Reports Server (NTRS)

    Mciver, D. E.

    1984-01-01

    An overview of NASA research activities related to the control of aeronautical vehicles is presented. A groundwork is laid by showing the organization at NASA Headquarters for supporting programs and providing funding. Then a synopsis of many of the ongoing activities is presented, some of which will be presented in greater detail elsewhere. A major goal of the workshop is to provide a showcase of ongoing NASA sponsored research. Then, through the panel sessions and conversations with workshop participants, it is hoped to glean a focus for future directions in aircraft controls research.

  10. IWHS Elevator Controller Study.

    DTIC Science & Technology

    1978-11-24

    the SSR ’s the LED is used to indicate the excitation across the two input ter- minals. 7.3 STATIC LOGIC LOU This design approach uses DC / DC ...14 16-bit bidirectional shift register , 5111 DC $5 505 Malt i pl ao e r . D ig ital IA Ten 2-input digI ta l eult lp l e n er s . LPTTI . AP 56 (RN...controller was precipitated by the lack of spare parts for , and the poor maintenance of , the present controller. Design approaches based on relay

  11. Pipe Line Control

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The array of tanks, pipes and valves in the photo below is a petroleum tank farm in Georgia, part of a petrochemical pipe line system that moves refined petroleum products from Texas and Louisiana to the mid-Eastern seaboard. The same pipes handle a number of different products, such as gasoline, kerosene, jet fuel or fuel oil. The fluids are temporarily stored in tanks, pumped into the pipes in turn and routed to other way stations along the pipe line. The complex job of controlling, measuring and monitoring fuel flow is accomplished automatically by a computerized control and communications system which incorporates multiple space technologies.

  12. Tank depletion flow controller

    DOEpatents

    Georgeson, Melvin A.

    1976-10-26

    A flow control system includes two bubbler tubes installed at different levels within a tank containing such as radioactive liquid. As the tank is depleted, a differential pressure transmitter monitors pressure differences imparted by the two bubbler tubes at a remote, shielded location during uniform time intervals. At the end of each uniform interval, balance pots containing a dense liquid are valved together to equalize the pressures. The resulting sawtooth-shaped signal generated by the differential pressure transmitter is compared with a second sawtooth signal representing the desired flow rate during each time interval. Variations in the two signals are employed by a control instrument to regulate flow rate.

  13. Communicating Networked Control Systems

    DTIC Science & Technology

    2007-03-31

    Bahamas, pages 1010-1015. 64. Carmen Del Vecchio and I.C. Paschalidis, “Supply Contracts with Service Level Requirements”, Proceedings of the IFAC...control using Monte Carlo sensing,” Proc. IEEE International Conference on Robotics and Automation, pp. 3058-3063, 2005. 10. S.B. Andersson, A.A. Handzel, V...Analysis, Madrid Spain. 20. S. Andersson and D. Hristu-Varsakelis, “Language-based feedback control using Monte -Carlo sensing”, to be subm. To IEEE Int’l

  14. Blood Pressure Control

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Engineering Development Laboratory developed a system for the cardiovascular study of weightless astronauts. This was designed to aid people with congestive heart failure and diabetes. While in space, astronauts' blood pressure rises, heart rate becomes unstable, and there are sometimes postflight lightheadedness or blackouts. The Baro-Cuff studies the resetting of blood pressure. When a silicone rubber chamber is strapped to the neck, the Baro-Cuff stimulates the carotid arteries by electronically controlled pressure application. Blood pressure controls in patients may be studied.

  15. Power semiconductor controlled drives

    NASA Astrophysics Data System (ADS)

    Dubey, Gopal K.

    This book presents power semiconductor controlled drives employing dc motors, induction motors, and synchronous motors. The dynamics of motor and load systems are covered. Open-loop and closed-loop drives are considered, and thyristor, power transistor, and GTO converters are discussed. In-depth coverage is given to ac drives, particularly those fed by voltage and current source inverters and cycloconverters. Full coverage is given to brushless and commutatorless dc drives, including load-commuted synchronous motor drives. Rectifier-controlled dc drives are presented in detail.

  16. NEUTRONIC REACTOR CONTROL

    DOEpatents

    Metcalf, H.E.

    1958-10-14

    Methods of controlling reactors are presented. Specifically, a plurality of neutron absorber members are adjustably disposed in the reactor core at different distances from the center thereof. The absorber members extend into the core from opposite faces thereof and are operated by motive means coupled in a manner to simultaneously withdraw at least one of the absorber members while inserting one of the other absorber members. This feature effects fine control of the neutron reproduction ratio by varying the total volume of the reactor effective in developing the neutronic reaction.

  17. AUTOMATIC LIGHT CONTROL

    DOEpatents

    Artzt, M.

    1957-08-27

    A control system for a projection kinescope used in a facsimile scanning system and, in particular, meams for maintaining substantially constant the light emanating from the flying spot on the face of the kinescope are described. In general, the invention provides a feeler member disposed in such a position with respect to a projecting lens as to intercept a portion of the light striking the lens. Suitable circuitry in conjunction with a photomultiplier tube provides a signal proportional to the light intensity of the flying spot. The grid bias on the kinescope is controlled by this signal to maintain the intensity of the spot substantially constant.

  18. Pointing control for LDR

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Briggs, C.

    1988-01-01

    One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

  19. Towards cheaper control centers

    NASA Technical Reports Server (NTRS)

    Baize, Lionel

    1994-01-01

    Today, any approach to the design of new space systems must take into consideration an important constraint, namely costs. This approach is our guideline for new missions and also applies to the ground segment, and particularly to the control center. CNES has carried out a study on a recent control center for application satellites in order to take advantage of the experience gained. This analysis, the purpose of which is to determine, a posteriori, the costs of architecture needs and choices, takes hardware and software costs into account and makes a number of recommendations.

  20. DETAIL INTERIOR VIEW OF CONTROL PANEL IN CONTROL STATION, VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL INTERIOR VIEW OF CONTROL PANEL IN CONTROL STATION, VIEW TOWARDS WEST - St. Lucie Canal, Lock No. 1, Control Station, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL